The Malaysian Issues of Teens and Sexuality

The Malaysian issues of teens and sexuality. Teen pregnancies have been a virus that recently sprung out in Malaysia; it is only more recently that we have seen the growth and its severity affecting the youth. Are Malaysian teen not receiving enough sex education causing the statistic to rise even further? This question how teen pregnancy has evolved and how times have changed bringing upon a serious social issue. To begin, the statistic provided by Ministry of Health (MOH) published by The STAR newspaper (22th September 2012), there are 18,532 pregnant teens age ranged from 10-19 years old in the year 2011.There are 4222 that were unmarried. It is more than 30 % pregnant teens that were unmarried. The statistics also show a drastic rise between the number of pregnancies and unwed teenagers. As teenager become more sexually active, doctors and the MOH are sounding over the increase in the rate; we often ask is having â€Å"it† worth it? Most sexual activity that happens to tee nagers below 20 years old, leads not only to unwanted pregnancies but also cases like baby dumping and also illegal abortion. Getting pregnant is only the beginning; there would be more decision to make and choices to choose from further down the road.Pregnancies among teenager mostly begin with the talk of sexual activity. According to the article â€Å"Porn story service a teen bestseller† complied by Winnie Yeoh of The Star Online, the Malaysian teenager get erotic contents on their phones. as the world moves to a modern era, the youngsters were subscribing to an Indonesian pornographic story on their smart phones for RM 17 a week. They would gather and talk about it while feasting on the dirty pictures. This is one of the reason why more and more of them would fall into the teenage pregnancy trap.When interviewed, Rosli (not his real name) states that they were unaware of the consequences of free sex and not using contraception. The social change that leads to this is mos t of the time related to a change in the nature of adolescence. At the age of 10-19, most of the teenager reaches the level of puberty and curiosity to try out sex rages. Some violated the use of the internet to search and research on the term â€Å"sex†. Others may find alternative to satisfy their need thru pirated cd and magazines. Many problems arise from the curiosity of teenager towards the topic of sex. They

An Archery Test Rig Made Using Computer Aided Design

University Malaysia Pahang Faculty Of Mechanical Engineering Project Work Report Subject : Computer Aided Design Code : Bmm2613 Lecturer : Mohd Azrul Hisham Bin Mohd Adib [email  protected] Edu. My Session/Semester : 2012/2013 Semester 1 Groupname : Group 3 ‘the Expendables' Project Submission Date : (Week 13) Report Due Date : (Week 13) Group Members : Siti Nursoleha Binti Mohd Rosdima12060 Poo Suk Sengma11067 Amirah Fatin Binti Amranma12057 Nur Shamimi Binti Shahirolmc12033 Lee Sing Soonmg11008 Subject : Computer Aided Design Code : Bmm2613 Lecturer : Mohd Azrul Hisham Bin Mohd Adib [email  protected] Edu. My Session/Semester : 2012/2013 Semester 1 Groupname : Group 3 ‘the Expendables' Project Submission Date : (Week 13) Report Due Date : (Week 13) Group Members : Siti Nursoleha Binti Mohd Rosdima12060 Poo Suk Sengma11067 Amirah Fatin Binti Amranma12057 Nur Shamimi Binti Shahirolmc12033 Lee Sing Soonmg11008 Lecturer’s Declaration We hereby declare that we have checked this project and in our opinion this project is satisfactory in terms of scope and quality for the award of the degree of Bachelor of Mechanical Engineering. Signature: Name of Supervisor: Mohd Azrul Hisham Bin Mohd Adib Position: Lecturer in Computer Aided Design of Universiti Malaysia Pahang Date: 11 December 2012 STUDENT’S DECLARATION We hereby declare that the work in this project work is our own except for quotations and summaries which have been duly acknowledged.The project work has not been accepted for any degree and is not concurrently submitted for award of other degree or even been used by other industrial or non-industrial company associated. Signature: Name: Siti Nursoleha Binti Mohd Rosdi ID Number: MA12060 Signature: Name: Poo Suk Seng ID Number: MA11067 Signature: Name: Amirah Fatin Binti Amran ID Number: MA12057 Signature: Name: Lee Sing Soon ID Number: MG11008 Signature: Name: Nur Shamimi Binti Shahirol ID Number: MC12 033 Date: 11 December 2012 ABSTRACT This project work is about creating a strong design based on the topic given to us which is archery test rig.To achieve the project objective, the test rig structure must be design and suitable for place the archery testing apparatus. We need to develop tools that can test the efficiency in archery equipment. The arrows were made of pine and consisted of a main shaft and about 15–20 centimeter (6–8 inches) long fore shaft with a flint point. This led the commercial development of new forms of bow including the modern recurve and compound bow. These modern forms are now dominant in modern Western archery while traditional bows are in a minority.In the 1980s, the skills of traditional archery were revived by American enthusiasts, and combined with the new scientific understanding. As we know, test rig machine that is use in industrial is very expensive in the market and some way need to be build by engine performance analysis based on functionality of power supply. Hence, our test rig been replaced with modern one where its materials very cheap and easy to find in market. Some sketches software had used like Solidworks to draft out the shape of our archery test rig.Materials selection also included in this designed process. Variable height and angle will be given at various speed by the stretch of bow’s string to see whether performance of archery will decrease or increase. Here, we can analyze at which arrow speed is the optimum of performance from this small mechanical. So, some losses like power and fuel can be decrease. AKNOWLEDGEMENT In the name of Allah, the Most Benevolent and the most Merciful. All the praise and blessing be upon Prophet Muhammad S. A. W.. Every sincere appreciation and gratitude is only to God.Only by His Kindness and Guidance that this project work report is finally completed . In preparing this report, we have in contact with many people and academicians. They had contributed to ward my understanding, thought, and also guidance. In particular, we wish to express my sincere appreciation to our main lecturer, Mr. Mohd Azrul Hisham Bin Mohd Adib for his valuable guidance, advice and continuous encouragement, constructive criticism and suggestion throughout this project. Without his continued support and interest, this project work would not have been the same as presented here.My sincere also extends to all our beloved family especially our parents, because if it’s not of their prayer and support we would not be here and done this project work. Moreover, we would like to thanks for all our colleagues and other who has provides assistance at various occasions. Their view tips are useful indeed in helping us to achieve doing this project. Because of their courageous, we can still stand to complete this project. Hence, to all people that direct or indirectly involve accomplishing our project that we were been sincerely thankful. TABLE OF CONTENTS PageSUPER VISOR’S DECLARATIONii STUDENT’S DECLARATIONiii ACKNOWLEDGEMENTSv ABSTRACTvi TABLE OF CONTENTSvii CHAPTER 1INTRODUCTION I. Objective II. Literature Review III. Market Survey IV. Comparison between Our Design and Current Design CHAPTER 2METHODOLOGY I. Plan to Design the Product II. Conducting the Solidworks III. Gantt Chart IV. Flow Chat CHAPTER 3RESULTS AND DISCUSSION I. Isometric View II. Assembly Part III. Orthographic View i. 1st Angle ii. 3rd Angle IV. Sectional View V. Discussion of Every Part VI. New Design Part CHAPTER 5CONCLUSION AND RECOMMENDATIONS REFERENCES APPENDICES I.Design Scratching LIST OF TABLES LIST OF FIGURES LIST OF ABBREVITIONS CHAPTER 1 INTRODUCTION I. OBJECTIVE i. To design small test rig for archery’s equipment game. ii. To test a performance of the test rig of the archery’s equipment efficiencies that is the bow and arrow. iii. Survey to mechanical engineering laboratories and also to shop market. iv. To design small mechanical te st rig using Solidworks software. v. To collect and select cheapest components and materials of test rig. vi. Trying to think of a cheap material and good quality to be used as the primary material in test rigs. vii.Design a multifunction test rig structure, means that, there are other components can be added in the future because of the extra spaces. viii. To conduct a simple analysis of the design of the test rig and to set up the full design in Solidworks. II. LITERATURE REVIEW i. INTRODUCTION This chapter will briefly explain about basic concept of archery’s test rig, foundation of test rig performance testing, the importance of test rig performance testing, development of test rig performance testing, principle of jack and a few related studies and journals that have been done by current researchers.All this information is important before furthering to the analysis and study later. ii. BASIC CONCEPT OF TEST RIG PERFORMANCE Archery test rig performance characteristics ar e convenient graphical presentation of archery test rig performance. They are constructed from the data obtained during actual test runs of the test rig and are particularly useful in comparing the performance of one bow and arrow with that of another. In this section some of the important performance characteristics of the test rig are discussed.It is to be noted that there is a certain speed, within the speed range of particular length of string stretched, at which force applied that is the length of string stretched will be the maximum. At this point, the maximum speed can therefore be exerted on the bow. For all practical purpose, the spring constant or bow capacity to do work also will maximum at this point. As the speed of the arrow is increased above this speed the quantity of the indicated time will decrease. However, the work output of the test rig increases with the speed due to longer length is executed per spring stretched.It should be note that the external air resistan ce will continue to increase with increased arrow speed until some point is reached where the air resistance almost can be negligible due to rapid movement of speed per second. Test rig are so designed that the maximum speed applied point is reached within various angle and height of the test rig. Increase in speed applied means that the increased targeting can be added per unit time increasing the work output. iii. FOUNDATION OF TEST RIG PERFORMANCE TESTINGTest rig performance is really a relative term. Normally it is represented by typical characteristic curves which are functions of testing at some variable of some situation and for our case is archery game. The term performance usually means how well a system designed is doing its job in relation to the input energy or how effectively it is provides useful work in relation to some other comparable industrial test rig machines. Most of the testing of test rig for their performance characteristics takes place under laboratory cond ition.The test rig is connected to a mechanical-based devices such as jack, spring and usual lift up mechanism by lifting the height of the steel in particular joint part. However, the performance characteristics of work, speed versus string stretched, degree of angle, height of devices of bow and arrow are recorded. There are so many types of industrial test rig used but using automation to quickly perform measurements and evaluate the test results. Principle that we used is mainly just simple mechanism that involve physics law and design it using Solidworks software.Our design of test rig operation is to allow the casing the arrow to swing freely with various variables that we figure out in this evaluation. The reaction string stretched various length, L, which is exactly equivalent to the speed measured on a level speed per time, ? , from the line section of the bow there are angle elevated, ?. The height of the test rig also can be organized. This restrains the attach casing of bow’s holder from revolving, or the speed and work would not be affected. Then, there are several factors that must considered in evaluating the performance of the test rig.Most of them are maximum work or speed available at each length string stretched within the useful particular of variable. iv. THE IMPORTANCE OF TEST RIG PERFORMANCE TESTING Today the most common power source is the well-known in industrial test rig machine. This type of test rig machine has been the choice due to efficient and accurate result in testing equipment for an example. For out invention may become natural choice due to low cost and portable properties. The portable characteristics shown may be easy because does not any electrical supply due to mechanical works only use in our test rig and easy to moves by just man-power.Industrial test rig machine as we know it today is not able to comply with future emission demands due to its massive cost and power used not very appropriate for some minority f ield. However, in the future manufactures must come up with new cost-efficient test rig technologies that still deliver the same or improved performance for customer satisfaction. III. MARKET SURVEY Test rig is an apparatus used for assessing the performance of a piece of mechanical or electrical equipment. In our case is to assessing the performance of archery’s equipment that is the bow and arrow.The experiment can be undergoing when we test how far the arrow can shoot in such length per time in particular length of string stretched. Example of test rig used in industrial field: * Aircraft Research Association – Wind Tunnel Testing Facility at Bedford, UK. Detail design for the upgrade of their existing transonic wind tunnel. * Rolls Royce – Aero Engine Test Facility at Derby, UK. Design, supply and site installation of a range of specialist fabricated gas catchers for use while testing jet engine reverse thrust. * Babcock Marine – Devonport Naval Docky ard at Plymouth, UK.Provision of test facilities to allow training of key personnel involved in the nuclear submarine decommissioning programmed. As an addition, from a long-term perspective, the most important sector linking Turkey to the global economy is manufacturing. The share of manufactured goods in the total exports of Turkey increased from 37% in 1980 to 93% in 2009. Increase in the volume of foreign trade between 2002-2008 is also remarkable. $87 billion volume of foreign trade in 2002 rose at an annual rate of 25%, to reach $334 billion in 2008, $243 billion in 2009.This shown that test rig machine is very important to test some equipment. In archery manufacturing, the efficiencies for the bow and arrow to working simultaneously to shoot the longest with accurate moment and high speed is required for an excellent product. Platts is a leading global provider of energy and metals information and the world’s foremost source of price assessments in the physical energy markets. Since 1909, Platts has enabled the markets to operate with transparency and efficiency, and helped traders, risk managers, analysts, and industry leaders make better trading and business decisions.Platts Report: The aluminum alloy market – strong but beset with uncertainty – examines in detail activity throughout the sector and beyond, in Europe, the US and Asia over the past few months and helps bring focus to the outlook of Q1 2012. Comparison of Al and steel Global Aluminum Market to Reach 71. 2 Million Tons by 2018, According to New Report by Global Industry Analysts, Inc. GIA announces the release of a comprehensive global report on the Aluminum markets. The global market for Aluminum is forecast to reach 71. 2 million tons by the year 2018.Major factors driving growth in the Aluminum market include increasing demand for the metal in developing countries, lower per capita consumption of Aluminum in emerging markets, increasing applications of Aluminum in various sectors, increasing regulations in the automotive sector that are driving use of Aluminum, and recovery in demand from end-use segments post-recession. Asia-Pacific represents the largest regional market for aluminum worldwide, as stated by the new market research report on Aluminum. China and India are emerging as the major drivers of global growth in consumption of aluminum.Europe represents the second largest regional market worldwide, followed by the US. Growth in the global aluminum market is projected to be driven by the Rest of World market, which includes the Middle East and Africa. The regional market is projected to post a compounded annual growth rate of 11. 1% during the analysis period. Extruded Products represents the largest market segment for aluminum. However, Rolled Products are projected to spearhead growth in the global aluminum market. Our suggestion is strongly to use Aluminium alloy as a material for our test rig. The characterized by a relatively low density (2. g/cm3 as compare to 7. 9g/cm3 for steel), high resistance to corrosion in some common environments. Our test rig is showing portable properties that allow this to be use even in hot field, including the ambient atmosphere it can resist form corrosive oxygen content in natural environment. Many of this alloys are easily in the process of fabrication virtue to high ductility. The mechanical strength of aluminium can may be enhanced by cold work and by alloying with another metal or non-metal. Aluminum Alloy Product Description Specifications: Tensile Strength(psi): 83000 Yield Strength(psi): 72000Elongation(%2†³): 11 Hardness: 158 IV. COMPARISON BETWEEN OUR DESIGN AND CURRENT DESIGN In Figure above that is the advance industrial test rig machine for testing the car door system. Basically our design is inspired by above design but more less cost and in simplify form. We eventually make a portable test rig that can be brought to any places. Testing facilities and test r igs come in many forms and are used within a broad spectrum of industries. They perform a variety of key functions from product validation through to the training and development of operators. The benefits from our design of test rig: ) The material used is easy to find in market and very popular in making of industrial machine. We are suggesting aluminum alloy due to high strength that is more mechanical properties shown in steel. b) Complete bespoke design and supply of unique test rigs to suit individual archery player specified requirements. c) Modification and upgrades to existing test facilities. d) Specialist components for integration into new test equipment. e) Shop assembly and proving of specific test rigs. f) In recent years we could have successfully completed a number of high profile projects involving test equipment. g) Globalization. ) Ongoing liberalization of international financial and commercial system. i) Foreign investors’ being directed to the fields ac celerating technological-social dynamics in archery. j) Rapid development and increase in effective use of information technologies and innovation. k) Technological developments. l) Increase in the size and purchasing capacity of domestic market. m) Richness of renewable and alternative energy sources. n) Development of competitive new business models. o) Development of institutionalization and corporation culture. p) Coming into prominence of the partnerships between countries. ) Increasing importance of added value product production, quality and efficiency of archery’s bow and arrow. r) Increasing of the information based (producing and utilizing information) competitive advantage. s) Increasing demand for new, high-quality and different products in the global markets with low cost. t) Contribution of the positive developments related to environment and climate changes to the competitiveness. CHAPTER 2 METHODOLOGY I. PLAN TO DESIGN THE PRODUCT The actual construction was v ery similar to the preliminary design. The end test rig, when fully assembled.The mechanism is the height can be change by requirement of user. There are two blocks that are used for joints of supporting another holder of the arrow as well as the traction rope length u bow in the spring in the valve use to draw and release the bow string when want shoot. The angle of the bow can also be changed by using the ball and socket as our knees. There is another part that supports the ball and socket is attached to one of the blocks that support the horizontal position of the bow string pullers. The height of this test rig can be changed under by jack at the bottom part of the test rig.Jack with rotor will be rolled over by man-power only and it will lift the top part of the test rig. In the preliminary design two supporter were described below in our drawing, master spring switch length and a socket and ball joint in that can joint the bow with the spring switch length . In the actual desig n, these 2 parts were combined into a single part switch that also has a pull/push holder- feature. Many features were added to aid in the setup and tear down of the test stand. The upper part and the lower part both have straight plane that come in contact with the base, and at each of these points there is a single ? n bolt. At the base of each upper 2 block supporter and after the jack assembly there are plane quick that can be disconnects which allow them to be separated from the rest of the structure. The electrical connection is not exist at all in this test rig. All these features allow for the test stand to be assembled and disassembled in approximately 10 minutes. Actual Test Rig Picture shown below: Door testing for its joints and locking setup Testing. Small testing setup installed on seats for complete cycle testing of all for doors of the car.Calculation of door closing and opening speed with the accurate door displacement by servomotor. Reports and data can be visualiz ed on remote PC outside Car. The torsion fatigue test rig (TFTR) was constructed to experimentally characterize the fatigue behaviour of materials that fail due to oscillating shear stresses. It consists of a base, hydraulic rotary actuator, and torque cell. Given the horizontal configuration of the rig, light weight mechanical adapters were designed to interface with the torsion bar specimens to minimize the interference of bending moments on the tests results.The adapters are essentially custom designed collet fixtures with base flanges for mounting, and they use off-the-shelf collets and clamping nuts to retain the specimen and transmit torque. Tests are generally carried out in torque controlled mode and the prescribed torque levels/amplitudes are controlled through commercial software. In this case of our test rig, the speed can be evaluated by the length of string stretched in such angle specified. The height also can be determined in such way by jack illustrated mechanism.Our design of test rig operation is to allow the casing the arrow to swing freely with various variables that we figure out in this evaluation. The reaction string stretched various length, L, which is exactly equivalent to the speed measured on a level speed per time, ? , from the line section of the bow there are angle elevated, ?. The height of the test rig also can be organized. This restrains the attach casing of bow’s holder from revolving, or the speed and work would not be affected. Then, there are several factors that must considered in evaluating the performance of the test rig.Most of them are maximum work or speed available at each length string stretched within the useful particular of variable. V. FLOW CHART Report is for draft and design. While Presentation is about the whole work Report is for draft and design. While Presentation is about the whole work List the needed material List the needed material Study and gather information Study and gather information Des ign & Sketching Concepts Design & Sketching Concepts YES YES NO NO MODIFICATION MODIFICATION SOLIDWORKS SOFTWARE SOLIDWORKS SOFTWARE FINISH FINISHPRESENTATION PRESENTATION FINAL REPORT FINAL REPORT FINAL DISCUSSION FINAL DISCUSSION ANALYSIS ANALYSIS BRIEF DISCUSSION BRIEF DISCUSSION MARKET SURVEY MARKET SURVEY DESIGN & SKECTHING DESIGN & SKECTHING LITERATURE STUDY LITERATURE STUDY START START VI. GANTT CHART ACTIVITIES| WEEK 1| WEEK 2| WEEK 3| WEEK 5| NOTES| Group division| v| | | | 3 Design must be prepared| Briefing about project design| v| | | | -| Re-do design and lecturer’s approval| | v| | | Get lecturer approval| Do some literature review| | v| | | -| Gather information| | v| | | -|Start doing Solidworks| | | v| | 3 part is separated| Progress report| | | v| | -| Make presentation slides| | | v| | Slides for final presentation| Finish final report| | | v| | -| Present project| | | | v| -| VII. CONDUCTING SOLID WORKS 3 persons assigned to handle this Solidworks. Our des ign is also divided into three phases. The first phase is the jack, the second phase is the ball and socket that is used to change the angle position of the bow, and the third phase is parking bow string, pull and position of the spring in the valve.Isometric view, orthographic view, and sectional view is provided in our report. Assembly part is use to sketch this design. There are about more than 15 parts that have been assembly together in this design. The overall view we put it together in isometric vie. All the dimensions is in mm with the scale of 1:50. Information about the assembly and its components is limited in Large Design Review. Most of the capabilities in Large Design Review mode are limited versions of existing SolidWorks capabilities. Snapshots are available only in Large Design Review.While an assembly is open in Large Design Review, it can make changes to its components. The uses Filter Modified Components to visually indicate which components have been modified. S elective Open and related tools are available on the Large Design Review tab of the CommandManager. These tools let to set some or all components to resolved or to lightweight. The Large Design Review tab of the CommandManager provides access to commands so can be use when open an assembly in Large Design Review mode. Parameters refer to constraints whose values determine the shape or geometry of the model or assembly.Parameters can be either numeric parameters, such as line lengths or circle diameters, or geometric parameters, such as tangent, parallel, concentric, horizontal or vertical. Numeric parameters can be associated with each other through the use of relations, which allows to capture design intent. Features refer to the building blocks of the part. They are the shapes and operations that construct the part. Shape-based features typically begin with a 2D or 3D sketch of shapes such as bosses, holes, slots, etc. This shape is then extruded or cut to add or remove material f rom the part.Operation-based features are not sketch-based, and include features such as fillets, chamfers, shells, applying draft to the faces of a part, etc. Building a model in SolidWorks usually starts with a 2D sketch (although 3D sketches are available for power users). The sketch consists of geometry such as points, lines, arcs, conics (except the hyperbola), and splines. Dimensions are added to the sketch to define the size and location of the geometry. Relations are used to define attributes such as tangency, parallelism, perpendicularity, and concentricity.The parametric nature of SolidWorks means that the dimensions and relations drive the geometry, not the other way around. The dimensions in the sketch can be controlled independently, or by relationships to other parameters inside or outside of the sketch. In an assembly, the analog to sketch relations are mates. Just as sketch relations define conditions such as tangency, parallelism, and concentricity with respect to s ketch geometry, assembly mates define equivalent relations with respect to the individual parts or components, allowing the easy construction of assemblies.SolidWorks also includes additional advanced mating features such as gear and cam follower mates, which allow modeled gear assemblies to accurately reproduce the rotational movement of an actual gear train. Finally, drawings can be created either from parts or assemblies. Views are automatically generated from the solid model, and notes, dimensions and tolerances. CHAPTER 3 RESULTS AND DISCUSSIONS I. Isometric View II. Assembly Part III. Orthographic View i. 1st Angle ii. 3rd Angle IV. Sectional View V. Discussion of Every Part The body part is main part of the test rig. The body part is the support side of the test rig and as a connector.It holds the baton together with joint so that that joint clamp can hold it together stable. The joint is very important is in this test rig also because it is the main part that contains spring that will stretched inside it when baton is pulled by its holder that stuck the bow string in it. Joint clamp is functional in changing the position of the arrow angle. It can be measured 0o until 180o. This is may suitable for some player that plays with their bow arrow in such rare angle. The baton is part that joint in with the joint and the joint clamp. At the surface of the baton there is a hook that is used for the string to be put.The spring is used for the pulling the baton when want to launch the arrow in such speed and length the string being put in particular section hook. There are 4 section of hook that can be put the bow string. The base is eventually for the supporting the whole structure especially the jack. Link is used for linking with the hydraulic jack. Support part is for the hydraulic jack and as a base to put the body of the test rig. Connectors used in this test rig is just screw rod, side supporter screw, base screw, and long screw. This act as same functio n that is to connects part tightly. Free Body Diagram (FBD) VI. New Design PartSINGLE CAM TUNING: Arrow spine can affect the high/low ripping of the paper test for one-cam bows. In 2007 World Target Champion instructed us that weakspined arrow shafts out of his Mathews bow, the name of the bow will tend to tear nockhigh when paper testing. The stiffer spined shafts will tend to show a low nock tear through the paper. That’s one reason why some bow setups continue to tear nock high no matter where you adjust the nocking point location – the arrow is acting weak and needs to be switched for a stiffer shaft. This is why our test rig can produce many variable and can be added in improvement plan in future.ADJUSTING FOR LEFT AND RIGHT ARROW TEARS: Correcting arrow flight for nock-right and nockleft tearing traits through the paper is more difficult than correcting for up and down. An arrow tears left or right because its spine is not properly matched to the bow system. (Rem ember, we already eliminated arrow rest contact. ) These adjustments are numerous and don’t always get results if the arrow isn’t the proper spine or something major is wrong with the bow system. I remind you again that this is not a perfect world and you should not beat your head against the wall trying to get a perfect hole.Close is good especially if the vane slices through the paper are crisp and all test shots produce the same hole. A little high-left or a little high tear, less than a half inch from 8 yards, is very acceptable and tells you that the arrows are flying well. All that remains is to shoot for groups from some distance that matches the archer’s ability level. Our design that has 4 section of hook is very useful because force is very important in shooting the arrow. Furthermore, no power supply is used by our machine makes us tend to do it different section to differentiate how far can the arrow go when it is shoot form different section.CHAPTER 5 CONCLUSION AND RECOMMENDATIONS There is a significant volume of literature covering methodology and approaches to selecting indicators of sustainable development. There is certainly no shortage of suggested ‘criteria’ for indicators and it has been possible to combine the oft-quoted lists to form a comprehensive overview (box 3). Similarly, several engineers mutually advocate adopting a framework to provide a coherent, consistent and structured process to indicator selection. However, there is an apparent gap in the literature in terms of the actual application of indicators, successfully or otherwise.This suggests that more often than not the process of selecting indicators – from deciding which indicators to adopt, to how many and whether/ how to aggregate and communicate the results – can become so lengthy and complex that the implementation and reviewing of indicator data is never achieved. It seems all too easy to get hung-up on finding the ‘ perfect’ indicator, but as Bakkes (1997) describes, indicators compromise between relevance, scientific validity and measurability and will often have to be ‘optimally inaccurate’.Therefore, aspiring to achieve the best available indicator is far more efficient in practice. Whilst the process of selecting indicators is intrinsically important to successful implementation, and indeed a valuable learning experience in itself (Bell and Morse, 2003), it is important not to lose perspective. Indicators are not an end in themselves but a means for communication and to assist the policy and planning cycle. Bell and Morse (2003) explicitly argue that to date, very poor, if any relationships between indicators and policy change have been demonstrated.They quote Reid’s (1995 in Bell and Morse, 2003: 50) analysis of why: a lack of awareness of the issues; political unacceptability of many actions; opposition from entrenched interests; and inadequate institutional res ponses. Therefore, it is important to be aware of these potential barriers when designing indicators and to ensure that monitoring them is seen as an integral part of the planning cycle, rather than a routine data collection that is not part of the institution’s decision making and learning cycle; hence ensuring that â€Å"energy [is] directed towards achieving sustainability, not just measuring it† (DSCWG, 2001).Furthermore, the cyclical, ‘feedback’ nature of indicator selection and implementation should be upheld. Just as policy needs to react to indicator data, the indicators also need to be flexible to adjust to possible changes in policy priorities and objectives. Developing a reliable and useful set of indicators that truly reflect the multidimensional nature of sustainable development is clearly a complex task.However, â€Å"if sustainable development is one of the tourism industry’s major contemporary objectives, then the industry needs to be able to measure its performance and impacts in this area† (Ko, 2005:432); undertaking this process, through adopting a framework to selecting indicators and acting upon their results, is worth the time and effort required to get it right. The implementation of the Annotation project has clearly demonstrated the concepts underlying the system to be entirely feasible, with, of course, the previously mentioned alterations and reservations.The Moderation subsystem required the use of authentication methods, currently under investigation within the JISC project umbrella at this time, in order to be realistically implemented. Several authentication projects under development will soon become available; using any such suitable project, it is possible to enable an implementation of the moderation system in the real world. Amongst other applications, annotation could also be considered as searchable metadata. This would permit a wider reach for site or content searching mechanisms. During this roject, the idea was considered, but constraints due to the design made it impractical —the definition of the project stated clearly that, as a completely independent service, its existence or otherwise should not in any way influence the operation of the resource finder. As such, it would have been inappropriate to link the Resource Finder’s operation to the annotations. As an example scenario, one might imagine a researcher who reads a paper in a given context and, whilst annotating the document, drops a reference to several other resources r concepts. A researcher searching on one of these associated concepts may therefore be referred to this article as a consequence of the annotation; in this way, one might imagine that searching ’backwards’ from annotation information may provide, perhaps surprising, and perhaps useful associations. While doing this project we realize that potentially it came from us the developing our strength to become more knowledgeable in this real-life world. We are exposed to the market survey, the material used and the important thing is to design something.At last, to wrap up this conclusion with a question, introduced as a statement; the possibilities provided by the storage of annotation metadata are certainly wide enough. Annotation metadata alone is a potentially rich resource; when combined with other information, such as contextual background information, the possibilities are endless. Applying contextual information, for example, could help the sorting through search terms to locate more relevant resources. What other metadata exists that could contribute to the usefulness of an annotation? REFERENCESI. Global Industry Analysts, Inc. , (GIA) http://www. strategyr. com/Aluminum_Market_Report. asp II. â€Å"Commission on Growth and Development. 2007. â€Å"The Growth Report,† Washington, D. C. III. Rodrik, D. 2007. â€Å"What does China export? China and the World Economy IV. w ww. disability. wa. gov. au V. Learning Guide  © 2009 The University of Adelaide VI. DavyMarkham – Products – Test Rigs VII. NaRec – Wind Turbine Test Facility at Blyth, UK. Design study VIII. End of Project Report, by Gregory J. L. Tourte, UKOLN,The University of Bath, August 2003 IX.

Critical Review Paper Expansion Term Example | Topics and Well Written Essays - 2500 words

Critical Review Expansion - Term Paper Example Their views are important for international political thought, because they influenced present international political economy theories and helped paved the debate on political ideology, particularly shaping the discourse on the concept of â€Å"civil society† and the rise of nation-states vis-a-vis â€Å"civil society.† Kant, Rousseau, Locke and Hobbes have diverging views on the relationship between the government and civil society, as well as the notions of slavery, sovereignty, direction of international politics, and peace, but they share somewhat similar beliefs in the role of education and the state of nature of humanity. Locke and Hobbes have diverging views on the relationship between the government and civil society. Hobbes believes that Europe has changed as a civil society through the evolution of the social contract. The Commonwealth only exists because of the Covenant between the people and the government or the state. Hobbes says in the Leviathan: â€Å" Essence of the Common-wealth; which (to define it) is ‘One Person, of whose Acts a great Multitude, by mutual Covenants one with another, have made themselves every one the Author, to the end he may use the strength and means of them all, as he shall think expedient, for their Peace and Common Defense.’† This statement shows that the main goal of the government is to ensure peace and national defense. The covenant or social contract, however, for Hobbes is absolute, where the state incorporates the wills of the individuals; the state is the body and individuals are just parts of it: â€Å"The only way to erect such a Common Power† is â€Å"to confer all their power and strength upon one Man, or upon one Assembly of men, that may reduce all their Wills, by plurality of voices, unto one Will† (Hobbes). This statement underscores that the social contract binds all individuals. On the one hand, it enforces plurality of wills. On the other hand, it means the precedence of the state over civil society. Locke confirms the same views as Hobbes and argues that Europe also changed because of the need for the social contract. Unlike Hobbes, Locke believes that people take part of social contracts merely to help adjudicate disputes between individuals or groups. He says: â€Å"And this is done, where-ever any number of men, in the state of nature, enter into society to make one people, one body politic, under one supreme government†¦to make laws for him, as the public good of the society shall require†¦Ã¢â‚¬  (Locke, Two Treatises on Government). From here, it is clear that Locke believes that it is the people or civil society that legitimizes the state; while for Hobbes, it is the government that legitimizes the existence of a peaceful civil society. My criticism of Hobbes is that he overlooks that the people make the government. The social contract binds the people, but the people can unbind some laws too in order to make the contract fit their changing needs and issues. I agree more with Locke, who reminds governments of their servitude to the civil society. It does not mean, however, that the civil society will also abuse its rights and fully void the social contract without due justifications. Moreover, Locke and Hobbes diverge on the notion of sovereignty. Locke argues that civil

Illegal Immigration Term Paper Example | Topics and Well Written Essays - 1750 words

Illegal Immigration - Term Paper Example Certain individuals may be interested in settling within the US just so that they could benefit from the health and social facilities in the country. The essay shall look at the reality of free riders and how this is linked to illegal immigration. Some individuals argue that illegal immigration is becoming a very serious problem in the US. Some of them attribute this to the open border policies that the US has adopted. Others claim that the real reason why illegal immigrants enter the US is so that they could use up the country's resources and then leave it for dead. (Beck 94) These proponents assert that these immigrants have no intention of ever becoming US citizens or upholding the law. Instead, they enter the country to access easily available employment opportunities. Usually, these people come into the country so that they can offer cheap labor for those respective industries or people that need them. In fact, a number of immigrants enter the country in order to pack industry products or do such duties. (Shapiro A8) These proponents also believe that all the latter micro-economic arguments do not hold much water. According to them there is a need to revise the country's immigration laws because of the fact that citizenship is worth very little to these people. Most of them may be merely interested in getting whatever little they can and then send it back to their own countries. Since such individuals are not well documented, then they are usually not obliged to respect the constitution as much as other groups do. (Shapiro A8) Proponents of this argument also claim that many illegal immigrants do not play by the rules. Since they are not US citizens, then they are not required to contribute directly to the country. Additionally, most of them may not offer their services for the betterment of the US. This school of thought also puts forward the fact that many illegal immigrants are actually flooding the country and causing situations in which locals are running out of work. The following industries heavily rely on illegal immigration The restaurant industry Housekeeping Construction Truck driving etc These proponents argue that illegal immigrants who are coming in for a free ride (through the social amenities in the country) are actually harming locals who may be required to pay their dues while at the same time compete with some of these illegal immigrants. Proponents of these ideas cite a series of statistics to support their claim. For instance, in the New York Times, it was stated that illegal immigrants who enter the country for a free ride are actually ruining the opportunities for other types of workers especially those ones who may not be illegal. It has been shown that most janitors in Los Angeles get close to nine dollars per hours; in other parts of the country, it could be slightly higher but not so far from this figure. What has happened is that some of these illegal immigrants have ended up dominating the profession. Most employers these days prefer using such illegal immigrants because they are sure that they will save up on substantial wage costs. However, the overall effect of this rush towards illegal immigrants

Mechanical Behaviour of Polypropylene Essay Example | Topics and Well Written Essays - 500 words

Mechanical Behaviour of Polypropylene - Essay Example These differences mean that the materials react differently with agents from the environment. Therefore, manufacturer must be in a position to appreciating these differences to avoid the production of plastic materials and products with premature failures commonly referred to as nasty and cheap. The plastic containers adopt the pseudo-elastic design methodology, which involves substitution of appropriate Poisson’s ratio and values of Modulus (that depend on temperature and appropriate time). The substitution involves using elastic standardised strain solutions, which depends on the geometry of the part and the load configuration. The method is appropriate for experimenting and investigating the design failures for polypropylene tanks. Some of the successful approach involve analysing the stress to the 4th order of the linear differentiation (Lewis and Weidmann, 1999a; Lewis and Weidmann, 1999b). The equation takes into consideration the transition between the vertical and the horizontal dimensions as well as the thickness. The manifestations of these transitions are accounted when the wall of the tank increases through radial expansion. The phenomenon can be described as stress concentration. The method involve assessing the strength parameters based on general values like stability (buckling, kinking), deformation (excessive bends), and strain or stress. Most failed tanks will fail at the welded construction at the joint level. Therefore, the best approach is to adopt a limiting stress criteria, which will aim to provide conservative alternatives to the problem (Lewis and Weidmann, 1999a; Lewis and Weidmann, 1999b). The design of the tank is very important. The hydrostatic pressure increases linearly and proportionally with the tank’s height. This means that the most appropriate strategy of resisting the pressure is by increasing the tank thickness. The same principle is applicable when constructing the walls

Perpetuating Disaster Myth through Film Essay Example | Topics and Well Written Essays - 250 words

Perpetuating Disaster Myth through Film - Essay Example The table below shows the presence of these myths in the two movies. In Outbreak, the Motaba virus spreads in US after the host animal (a monkey) is illegally brought to the United States. In Contagion, the disease spreads when a single cook forgets to wash his hands after handling a pig. In both the movies, the start of the disaster is the result of inconsequential events and not a dramatic event. Thus, the first myth is not present in either of the two movies. In Outbreak, even though the virus is localized to an area, the movie focuses on the large-scale impact of the disaster and ignores smaller events. On the other hand, Contagion looks at both the large-scale impact as well as small events. Thus, the second myth is present in Outbreak but not in Contagion. In Outbreak, the disaster becomes huge because it quickly kills 150 people in a small area. Similarly, in Contagion, 26 million people die globally. In both movies, the death of a large number of people emphasizes the magnitude of the disaster. Thus, the third myth is present in both the movies. The Outbreak suggests that if people are able to predict the disaster, they can prepare for it and prevent deaths. This does not apply to Contagion in which there seems to be no way of stopping the spread of virus. Thus, the fourth myth is present in Outbreak but not in Contagion. Outbreak uses the technocratic approach to solve the problem as scientists and doctors work hard to find a cure for the disease, an anti-serum. Contagion takes a much more holistic approach to fighting the disease with scientists and administrators pooling resources to fight the disease. Thus, the fifth myth is present in Outbreak but not in Contagion. From this analysis of the two movies, we see that compared to Outbreak, Contagion presents the disaster in a more realistic way. Contagion presents data to

Fianancial reporting and analysis Essay Example | Topics and Well Written Essays - 1000 words

Fianancial reporting and analysis - Essay Example In 2011, the international accounting standard board revised the existing financial standards, and issued a new set of standard for purposes of reflecting the changes in global business practices, economies of the world, and markets. The new rules are, consolidated financial statement (IFRS 10), joint arrangements (IFRS 11), disclosure of interests other entities (IFRS 12), separate financial statements (IAS 27), and revised associates and joint ventures (IAS 28). The consolidated financial statement (IFRS 10) was created for purposes of outlining the presentations of a consolidated financial statement. This rule requires business organizations to consolidate the entities that are under their control, and this includes giving them the rights of variable returns, and the capability of affecting the returns acquired over an investee (ACCA, 2012). On this basis therefore, the rule was created to institute the values that will guide the preparation of consolidated financial statements wh en one business organization controls one or more business organizations (ACCA study text, 2011). This rule was created for purposes of defining the concept of control of a business entity, and as a basis of consolidation. It establishes the principles of identifying whether an investor has some level of control over an investee, and therefore consolidating the investee (ACCA, 2012). This standard has the following key requirements; 1. It requires business organizations that have an interest in other business organizations to conduct an assessment in order to determine whether control exists or not. 2. In order for a business organization to control another business organization, the following characteristics must be present, rights to the benefits of variable returns because of the involvement of the business entity with the investee, authority over the investee, the ability to influence the investee for purposes of benefiting the investor. 3. An investor must have substantive righ ts for purposes of giving him control of an investee and legitimacy to control some affairs of the organization. Joint arrangements on the other hand outline the accounting procedures that business organization that jointly control an entity ought to follow. There must be a contractual agreement that denotes the control of an entity by the business organizations in question. Media (2011) denotes that joint arrangements are of two types, namely joint operations, and ventures. In a joint venture, net assets and equity are accounted for, while in a joint operation, accountant’s factor in the obligation of liability, and right to access the assets by the business organization under collaboration (ACCA study text, 2011). On this basis therefore, the International Accounting Board established this standards for purposes of determining the nature of a joint arrangement business organizations engage in. This is to enable stakeholders gain the capability of analyzing the rights and ob ligations of these business entities under the joint arrangement. For a joint arrangement to exist, the following are the main requirements (Gray and Manson, 2012); 1. There must be prove of control of the organization by the business entity involved. 2. The concept of unanimous consent must be present, and this

Benefits of Privatization Essay Example | Topics and Well Written Essays - 1250 words

Benefits of Privatization - Essay Example Privatization has been experienced by various organizations throughout the world over a long period of time. Various organizations that were owned and controlled by the government sector have been privatized due to the several benefits associated with privatization. One of the main reason due to which government’s tend to choose to privatize a previously state owned business is the failure of the government to operate the business in a an effective and efficient manner. This is mainly because government’s end up operating the business for the interest of politicians that are ruling the government and not working in the favor of the public of particular nation. This writing will focus on the various benefits that have experienced by organization due to privatization while debating the other side of the coin. Body Benefits of Privatization There have been various theories that favor privatization and there have been various practical incidences when privatization has resu lted in huge benefits to organizations and even nations. Privatization is pursued by organizations because the public sector has failed to operate in a profitable manner and the management of public organizations has not done their job in a proper manner. Governments themselves favor privatization and this happens as a result of the increased burdens experienced by government because of state ownership of organizations. When organizations are controlled by the government, governments tend to provide goods and services to the public in shape of subsidies, the management of such organizations work for the benefit of the overall population rather than meeting the demands of individual groups due to which organizations fail to meet the demands of the public and the unions in state owned organizations exercised higher amount of power than unions of organizations that are controlled by the private sector. Due to failure of the government sector to address the needs and wants of the indivi dual groups, individuals experienced dissatisfaction. According to surveys conducted by Donahue, in the region of United States organizations have experienced lower operating cost when they were privatized as compared to the period when they were under the control of the government (Holzer 88). Another reason due to which organizations become privatized is that governments do not operate with the main aim of maximizing profits for the organization and the shareholders of the organization. There tends to be ample amount of changes in the governance of organizations due to which these organizations become inefficient. Lastly, the pressure on governments is low as they do not have to worry about the bankruptcy of the organization as these organizations are never allowed to fail and they are financed by the tax money. Another reason due to which organizations are privatized is because this process helps the government in increasing their revenue. When organizations are owned by the publ ic sector, organizations do not pay taxes and become a burden on the tax payers to continue operating as they even do not work to attain profits. When organizations are privatized, they are obliged by the regulations to pay taxes on the profits they make and the profits they earn are used to fund the operations of the organization. Due to increase in the amount of taxes obtained through private enterprises, government is able to decrease its budget deficit as they do not need to obtain loan for operating the nation and they operate the nations with the revenue earned

The impact of the Industrial Revolution Essay Example for Free

The impact of the Industrial Revolution Essay The Industrial Revolution (1870 to 1920) led to various improvements in the social and economic conditions of the Canadians. The Industrial Revolution basically brought in a lot of positive changes for the people and after this only, progress in various fields such as agricultural and manufacturing, etc. became visible that in turn brought an overall improvement in the lives of the people by improving their social and economic conditions. However, it was not just Canada that benefited the impact of the Industrial Revolution but the entire world was able to reap the benefits. The most important and prevalent feature of the Industrial Revolution was the generation of wealth that led to modernization of the living style of the people. However, in the case of Canada the people who had more capital than the others became wealthier while the other population remained the same. The reason behind this was that the people who have capital made a different social class in the society while the working force (the labor force) of Canada did not get many benefits and only the people from the business class were in the position to survive well. The school going children were taught to be more obedient and to be punctual i. e. the mannerism that must be adopted at work was inculcated in the students. This therefore proves that the most emphasis that was given during this era was on how to generate more profits for the employers and the ways in which productivity could be increased. The employer mostly regarded their employees as machines and made them do work like machines as they wanted the best of their effacing at work. However, the workers who worked hard for the employers’ whole day were not even compensated fairly. It was however true that some of the provinces in Canada greatly benefitted from the Industrial Revolution that took place from 1870 to 1920, however some of the provinces such as Maritime Provinces of Canada suffered heavily and this was mainly because this was the hub for ship building but now after this Revolution the ships were mostly built with steel and not with wood. However, not enough equipment was available to the workers in this area in terms of technology due to which it lost its importance economically. Other than this, there were many other provinces such as Nova Scotia and New Brunswick where the technology for not available for the progress of the people but in the areas where technology was available, they progressed heavily. British Columbia was one such place in Canada that progressed economically after the Industrial Revolution. Mining, forestry and agriculture were the three main areas that made the most revenue for the economy of Canada and it was when Canada began to import these especially timber to the rest of the places in Canada further improved the transportation system in Canada as the introduction of trains further enhanced the conditions in the country. Later in 1911 when the hydro electricity was introduced, it further aided in making the economy more strong and as Ontario and Quebec were the hub of the powerhouses during 1980’s, these two places progressed rapidly and also resulted in a very rapid growth in the population. This was because the people who used to work in the farms previously moved onto the cities in order work as they could see large opportunities of work in the cities especially in the factories. However, due to this the rent of the houses became higher due to which the people had to share houses with the others and due to this the working class also began to send their children for work in order to fulfill their needs and this led to the exploitation of the children until a law was passed by the Factory Act that banned the employers to hire boys and girls below twelve and fourteen years of age. The progress in Canada made the classes of people more evident especially the high class and the working class. The people in Canada who were oppressed the most were basically the people who were from the working class and this is because previously their main source of income was from the farms they worked. Moreover, they were most dependent on the pigs they owned so that they could sell them and make their living especially in the winter season when work is not available readily. However, it was the wealthier group in Canada that banned the ownership of the livestock that enforced the people to buy commodities. I would therefore conclude by saying that the impact of the Industrial Revolution (1870 to 1920) on the social and economic conditions Canadians was both favorable and unfavorable but the classes that were affected by the former or the latter were actually the ones who had to face the outcomes. The business class was the one that benefitted the most but the working class was actually exploited. (Francis, Jones Smith, 2006). Reference Francis,D. R. , Jones, R. Smith, D. B. (2006). Journeys: A History of Canada. Thomson.

Software Reuse Essay Example for Free

Software Reuse Essay Abstract Effective reuse of software products is reportedly increasing productivity, saving time, and reducing cost of software development. Historically, software reuse focused on repackaging and reapplying of code modules, data structures or entire applications in the new software projects (Prieto-Diaz 1994). Recently, however, it has been acknowledgedas beneficial to redeploy software components across the entire development life-cycle, starting with domain modelling and requirements specification, through software design, coding and testing, to maintenance and operation. There were also attempts to reuse aspects of project organisation and methodology, development processes, and communication structures. However, as the concept of reusing software components is very clear at the code level (whether in source or binary form), the very same concept becomes more fuzzy and difficult to grasp when discussed in the context of reusing specifications and designs (whether in textual or diagrammatical form), or quite incomprehensible when applied to software informal requirements, domain knowledge or human skills and expertise (expressed in natural language, knowledge representation formalism, or existing only in humans). This problem of dealing with reusable software artefacts resulting from the earliest stages of software development, in particular requirements specifications, attracted our particular interest in the reusability technology. Our work is motivated primarily by the possibility of improving the process of requirements elicitation by methodical reuse of software specifications and their components with the aid of information extracted from user informal requirements documents. The problems and issues that we aim to investigate in this research are best illustrated by the following statement outlining current needs and the goals for the future research in requirements reuse: †¢ More research is needed on the advantages and the necessary methods for requirements reuse. For example, what are requirements components’, what makes them reusable, how can we store and retrieve them, and how do we write a requirements specification that gives us the highest probability of creating or reusing existing requirements components? (Hsia, Davis et al. 1993). Definitions To address the issues advanced by Hsia, Davis and Kung, and to avoid any confusion farther in this paper, we need to clearly define some major concepts of software reuse, reusability, reusable artefacts, their possible forms, reusability methods, their major motivators and inhibitors, etc. Hence, we adopt our definitions from Prieto-Diaz (Prieto-Diaz 1989) as follows :-†¢ reuse is the use of previously acquired concepts or objects in a new situation, it involves encoding development information at different levels of abstraction, storing this representation for future reference, matching of new and old situations, duplication of already developed objects and actions, and their adaptation to suit new requirements; †¢ reuse is the use of previously acquired concepts or objects in a new situation, it involves encoding development information at different levels of abstraction, storing his representation for future reference, matching of new and old situations, duplication of already developed objects and actions, and their adaptation to suit new requirements; †¢ reusability is a measure of the ease with which one can use those previous concepts or objects in the new situations. Reuse Artefacts The object of reusability, reusable artefact , can be any information which a developer may need in the process of creating software (Freeman 1983), this includes any of the following software components :- †¢ code fragments, which come in a form of source code, PDL, or various charts; †¢ logical program structures , such as modules, interfaces, or data structures; †¢ functional structures , e.g. specifications of functions and their collections; †¢ domain knowledge , i.e. scientific laws, models of knowledge domains; †¢ knowledge of development process , in a form of life-cycle models; †¢ environment-level information, e.g. experiential data or users feedback; †¢ artefact transformation during development process (Basili 1990); etc. A controlled collection of reuse artefacts constitutes a reuse library. Such libraries must contain not only reusable components but are also expected to provide certain types of services to their users (Wegner 1989), e.g. storage, searching, inspecting and retrieval of artefacts from different application domains, and of varying granularity and abstraction, loading, linking and invoking of stored artefacts, specifying artefact relationships, etc. The major problems in the utilisation of such reuse libraries are in determining appropriate artefact classification schemes and in the selection of methods to effectively and efficiently search the library. To bypass the problems with reuse libraries, the use of specialised domain-specific languages was proposed as an alternative. Such languages use strict syntax and semantics defined in terms of an application domain and its reusable artefacts. While enforcing notational conformance with a predetermined syntax and semantics, the domain-specific languages restrict the number of possible classification and search mechanisms used in the process of composing a problem solution, e.g. as in DRACO (Neighbors 1989) or GIST (Feather 1989). Artefact Characteristics Certain classes of software artefacts have been identified as eminently suitable to become part of a reuse library and be, subsequently, utilised as reusable software resources. Such artefacts usually share a number of characteristics, deemed to actively promote reusability (Biggerstaff and Richter 1989; Matsumoto 1989; McClure 1989), those artefact are perceived to be :-†¢ expressive, i.e. they are of general utility and of adequate level of abstraction, so that they could be used in many different contexts, and be applicable to variety of problem areas; †¢ definite, i.e. they are constructed and documented with a clarity of purpose, their capabilities and limitations are easily identifiable, interfaces, required resources, external dependencies and operational environments are specified, and all other requirements are explicit and well defined; †¢ transferable , i.e. it is possible to easily transfer an artefact to a different environment or problem domain, this usually means that it is self-contained, with few dependencies on implementation-related concepts, it is abstract and well parametrised; †¢ additive, i.e. it should be possible to seamlessly compose existing artefacts into new products or other reusable components, without the need for massive software modifications or causing adverse side effects; †¢ formal , reusable artefacts should, at least at some level of abstraction, be described using a formal or semi-formal notation, such an approach provides means to formally verify an artefact correctness, it enables to predict violation of integrity constraints during artefact composition, or to assess the level of completeness for a product constructed of reusable parts; †¢ machine representable, those of the artefacts which can be described in terms of computationally determined attribute values, which can easily be decomposed into machine representable parts, which can be accessed, analysed, manipulated and possibly modified by computer-based processes, have a clear potential for becoming part of a flexible reuse library; those artefacts can be easily searched for, retrieved, interpreted, altered and finally integrated into larger system; †¢ self-contained , reusable artefacts which embody a single idea are easier to understand, they have less dependencies on external factors, whether environmental or implementational, they have interfaces which are simple to use, they are easier to extend, adapt and maintain; †¢ language independent, no implementation language details should be embedded in reusable artefacts, this also means that most useable artefacts are those which are described in terms of a specification or design formalism, or those low level solutions which could be used from variety of programming languages on a given implementation platform, either by appropriate macro processors or link editors; †¢ able to represent data and procedures , i.e. reusable artefacts should be able to encapsulate both their data structures and logic, down to a fine grain of detail, such an approach increases artefact cohesion and reduces the possibility of artefact coupling by common data passed via arguments or global variables; †¢ verifiable , as any other software components, reusable artefacts should be easy to test by their maintainers, and, what is even of a greater importance, by their users who embed reusable components into their own systems, and who must have the capability to monitor the components computational context and their interfaces; †¢ simple , minimum and explicit artefact interfaces will encourage developers to use artefacts, simple and easy to understand artefacts can also be easily modified by developers to suit new applications; and †¢ easily changeable, certain type of problems will require artefacts to be adopted to the new specifications, such changes should be localised to the artefact and require minimum of side effects. Reuse in Software Life-Cycle Computer software can be systematically reused across the entire development life-cycle, i.e. domain analysis, requirements specification, design and implementation, it has its place even in the post-delivery stages of development, e.g. its continuing quality assessment or software maintenance. Implementation. Early experience with software reuse was limited to reuse of program code in source and binary form. A great emphasis was put on development of programming languages which could support various methods of clustering, packaging, modularisation, parametrisation and sharing of data and code via data types and code blocks (ALGOL), named common blocks (FORTRAN), parametric functions and macros (FORTRAN and LISP), copy libraries (COBOL), information hiding (PASCAL), modules (SIMULA and MODULA), generic packages (ADA), objects and classes (SMALLTALK and C++), etc. The idea of code sharing was further supported by various operating system utilities which allowed independent program compilation, creation of relocatable libraries or link editing (Reed 1983). In those early days, no serious effort on a commercial scale was undertaken to reuse the early life-cycle artefacts, i.e. designs, specifications, requirements or enterprise models. This situation was caused by :- †¢ the lack of awareness of potential benefits that could be gained from reusing more abstract software artefacts; †¢ unavailability of commercial methodologies embracing software reuse at their centre-point; †¢ informal nature of early specification and design documents; and †¢ shortage of tools capable to represent specifications and designs in a computer-processable form. At the same time, †¢ the construction of libraries was known to improve software development productivity, and was practiced in nearly every commercial organisation; †¢ program code was written according to a formal grammar and it adhered to established semantic rules; and †¢ the construction of code libraries was supported by editors, compilers, loaders and linkers, which could be freely customised to accommodate various reuse tasks. Design. Today’s development approaches, such as object-oriented methods (Graham 1994) or rapid application development (Martin 1991), vigorously advocate reusing software artefacts at the earliest possible stage of the software life-cycle. Program design methods are now capable of utilising well-defined diagrammatic notations, which allow production of documents which are simpler and more legible than code, which clearly exhibit their conceptual contents, which are well structured and modular, and which allow dealing with problem complexity at various levels of abstraction and granularity. With the advent of CASE tools (McClure 1989) the contemporary design techniques are also supported by specialised software environments capable of capturing design ideas in a form leaning towards further processing by computer-based reuse tools. Today, it is also commonly perceived that reuse of software designs, as opposed to code reuse, is more economic, and cognitively a much more intuiti ve process. Requirements Specification. While application of reuse techniques to software design has visible advantages over code reuse, some researchers (Matsumoto 1989) claim further increases in the scope of software reusability when given opportunity to reuse modules at higher levels of abstraction, i.e. software specifications and requirements. Others support this claim, voicing the need to reuse large-scale artefacts going beyond design components and including entire design frameworks and domain resources (Li 1993). Bubenko et. al. (Bubenko, Rolland et al. 1994) further propose to combine design and reuse libraries to accommodate development processes capable of reusing conceptual schemas to support the process of requirements engineering. Such an approach provides users with the library of reusable components that could match their requirements, improves the quality of requirements specifications by making available well-defined conceptual components as early as requirements specification, and improves the productivity of the requirements engineering process by shortening the requirements formalisation effort (Castano and De Antonellis 1994). In the REBOOT system, Morel and Faget (Morel and Faget 1993) aim at extending this approach to the entire software life-cycle. Such advances in requirements and specification reuse were in part facilitated by :- †¢ Development of the new types of programming languages, such as PROLOG or EIFFEL, which combine elements of program specification and design (via logic and class specification) at the level of code, such an approach promotes interpretation and reuse of abstract program descriptions throughout the life-cycle; †¢ dissemination of prototyping tools and visual programming environments capable of graphic representation of user requirements and the subsequent generation of code or code skeletons (Vonk 1989; Ambler and Burnett 1990), facilitating effective composition of programs of domain-specific, visual, reuse components; †¢ introduction of formal requirements and specification languages, such as RML (Greenspan, Mylopoulos et al. 1994), Z (Spivey 1989), VDM (Woodman and Heal 1993) or LARCH (Guttag and Horning 1993), permitting representation, structuring, verification, and reuse of specification components; †¢ object-oriented technologies integrating various diagrammatic techniques into a single methodology, e.g. Information Engineering (Martin 1993), or unifying elements of conceptual modelling, program specification and design into one consistent notation, e.g. Object-Oriented Conceptual Modelling (Dillon and Tan 1993), such object-oriented development methods allow creation of abstract conceptual schemata which can be readily adapted by instantiation and inheritance to new problem solutions; †¢ development of full-text databases utilising efficient information retrieval methods (Salton 1989), being introduced as a repository for storing, classification and subsequent retrieval of design and specification texts (Frakes and Nejmeh 1988; Maarek, Berry et al. 1991; Fugini and Faustle 1993); and finally †¢ application of knowledge-based techniques and intelligent software development assistants in requirements acquisition and specification (Lowry and Duran 1989); Domain Analysis. The final frontier for software reuse in the development life-cycle is a thorough analysis of a given problem domain. This approach is grounded on the belief that in a real-life situation reusability is not a universal property of program code or processed information but it rather depends on a context of the problem and its solution, which themselves are relatively cohesive and stable (Arango and Prieto-Diaz 1991). The main aim of domain analysis is the construction of a domain model of which components could be reused in solving variety of problems. Such a model will customarily include definition of concepts used in the specification of problems and software systems, definition of typical design decisions, alternatives, trade-offs and justifications, and software implementation plans. Such a model may take variety of different forms, to include (cf. Figure 1) :- †¢ definitional model, which provides knowledge taxonomies and actonomies describing domain concepts, their structure, semantics, and relationships between them; †¢ knowledge representation model, giving domain semantics and explanation facilities; †¢ domain-specific languages , which when expressed as formal grammars and supported by parsers may provide direct translation of specifications into executable code; †¢ instructional models , indicating the methods of constructing working systems in a given domain, such methods may be described by standards, guidelines, templates, or interface definitions; †¢ functional models, describing how systems work, using representations such as data flow diagrams or program description languages; †¢ structural models, provide means to define architecture of domain systems; etc. In the process of constructing a domain model, the common knowledge from related systems is generalised, objects and operations common to all systems in a given domain are identified, and a model is defined to describe their inter-relationships. The main problem with this process is that knowledge sources for domain modelling (as found in technical literature, existing implementations, customer surveys, expert advice or current and future requirements) are frequently verbose and informal. Thus, special techniques and tools are needed to deal with it, e.g. knowledge acquisition tools, entity-relationship modelling tools, object-oriented methods, semantic clustering tools, CASE and parsing tools (Agresti and McGarry 1988). Reuse Process. In this work, we will view the process of software reuse as comprising three stages of artefact processing (cf. Figure 2), i.e. their analysis, organisation and synthesis. †¢ Artefact analysis starts with identification of artefacts in existing software products (Ning, Engberts et al. 1994) or in a currently analysed domain (Arango and Prieto-Diaz 1991), this is followed by their understanding and representation in a suitable formalism to reflect their function and semantics, with possible generalisation to widen the scope of their future applications. †¢ Artefact organisation includes classification and storage of artefacts in an appropriate software repository, the subsequent repository search and artefacts retrieval whenever they are needed in the reuse process. †¢ Artefact synthesis consists of artefact selection from a number of retrieved candidate artefacts, their adaptation to suit the new application, and their integration into a completely new software product. The tasks undertaken in the three stages of artefact processing are also frequently discussed from the perspective of development-for-reuse and development-by-reuse (Bubenko, Rolland et al. 1994). †¢ Development-for-reuse is emphasising the construction of the reuse library, involving the identification, understanding , generalisation , and the subsequent classification and storage of artefacts for later reuse. †¢ Development-by-reuse is concerned with the effective utilisation of the reuse library to support new software development, it involves searching, retrieval , selection , adaptation, and integration of artefacts into the software system under construction. As reuse is quite independent of any particular development process model, it, thus, could be embedded into a variety of methodologies, to include waterfall model (Hall and Boldyreff 1991), rapid prototyping (Martin 1991), object-oriented design (Meyer 1987),etc. While the inclusion of reuse into a development cycle is of a significant benefit to the entire process, at the same time it may complicate the development process (e.g. see Figure 3). Also, reuse tasks may significantly overlap with those performed in other development phases, e.g. software integration or maintenance. The separation of concerns lead some researchers (Hall and Boldyreff 1991) into pointing out that reuse must occur across different projects or problem areas, as opposed to those tasks which aim at the change, improvement or refinement of software undertaken within a single project which should not be regarded as reuse, e.g. †¢ software porting , which only aims at adopting existing software product to different hardware or operating system environments; †¢ software maintenance , which strives to correct software erroneous behaviour or to alter the existing program to suit changing requirements; and †¢ software reconfiguration, which provides a method of customising software to be used with different hardware components or making only a subset of its facilities available to the user. Assessing the Reuse Process and its Goals The value of software reuse cannot be gauged in simple, unambiguous, congruous and canonical fashion. One of the reasons for this difficulty lies in the fact that there is a variety of reusable artefact types and the methods and techniques for their creation, manipulation and maintenance. Another reason can be set in inadequacy of measuring tools to assess the reuse benefit or its hindrance, as it can be measured using variety of incompatible metrics, some of which are based on economic, some on technical, then again others on social or cognitive principles. Finally, it is the numerous software stakeholders who are not likely to agree on the common goals of the reuse process itself, as they will all have distinct and opposing development goals. The contention on thee success or failure of reuse approaches is best reflected in the myths, biases and preconceptions of software developers and management, this section will, thus, summarise such opinions as they are reported in the software engineering literature. Reuse benefits. Adopting reuse-based software development process attracts a number of well recognised economic and psychological benefits to both the end-users and developers (Tracz 1988b; Hemmann 1992). These include the following. †¢ Savings in costs and time. As a developer uses already pre-defined components, hence, the activities associated with components specification, design and implementation are now replaced with finding components, their adaptation to suit new requirements, and their integration. Experience shows (also from other fields, like electronic engineering) that the latter set of activities takes less times and therefore costs less. It should be noted, though, that development of components for reuse will certainly attract additional effort, time and cost. This costs, however, can be offset by savings in a number of different software projects. †¢ Increase in productivity. A set of reusable artefacts can frequently be viewed as a high-level language of concepts drawn from a given problem domain. Hence, a developer is given an opportunity to work with more abstract notions related directly to the problem at hand and to ignore low-level, implementation details. It has been shown that working at a higher level of abstraction leads to an increase in development productivity. †¢ Increase in reliability. Reuse library can be viewed as a software product itself, therefore, its development follows a normal cycle of requirements specification, design, implementation, testing, documentation and maintenance. By the very assumption, the user base and a life-span of reuse artefacts is much greater than that of any individual product, thus, the reliability of such artefact is also increased. This also leads to an improved reliability of systems built of reusable components rather than of those built entirely from scratch. †¢ Increase in ease of maintenance. Systems constructed of reusable parts are usually simpler, smaller, and more abstract. Their design is closer to the problem domain and their reliability is greater. This of course has an very positive impact on the quality of such systems maintenance. †¢ Improvement in documentation and testing. Reusable components are normally accompanied by high quality documentation and by previously developed tests plans and cases. Whenever a new system is created by simple selection and altering of such components, then, their documentation and tests will have to be much easier to develop as well. †¢ High speed and low cost replacement of aging systems. As the reuse-based systems share a very large collection of program logic via the reuse library, thus, they are significantly less complex and much smaller in size than those developed from scratch. Such systems will therefore need less effort during porting or adaptation to new hardware and software environments. It should also be noted that it would normally be the reusable components of the system that is technology intensive, and thus, very expensive to develop, e.g. graphical user interfaces, databases, communications, device control, etc. Sharing that cost across several systems would certainly reduce it when a global replacement of computing resources is called for. Reuse drawbacks. At the same time, in practice, radical gains in productivity and quality cannot be achieved due to some preconceptions held by developers and their management (Tracz 1988b; Hemmann 1992). The claims commonly put forward by programmers include :- †¢ reusing code, as compared with development of entirely new systems, is boring; †¢ locally developed code is better than that developed elsewhere (NIH factor); †¢ it is easier to rewrite complex programs from scratch rather than to maintain it; †¢ there are no tools to assist programmers in finding reusable artefacts; †¢ in majority of cases, developed programs are too specialised for reuse; †¢ adopted software development methodology does not support software reuse; †¢ reuse is often ad-hoc and is unplanned; †¢ there is no formal training in reusing code and designs effectively; †¢ useful reusable artefacts are not supported on the preferred development platform; †¢ the reuse process is too slow; †¢ interfaces of reusable artefacts are too awkward to use; †¢ code with reusable components is often too big or too inefficient; †¢ programs built of reusable components are not readily transportable; †¢ reusable components do not conform to adopted standards; †¢ reuse techniques do not scale up to large software projects; †¢ there are no incentives to reuse software. Meanwhile, management also raises objections based on the following arguments :- †¢ it takes too much effort and time to introduce reuse in workplace; †¢ perceived productivity gains will result in cuts to the project man-power; †¢ customers may expect reusable artefacts to be delivered with their product; †¢ it may be difficult to prevent plagiarism of reusable artefacts; †¢ reuse of code may lead to legal responsibility in case of software failure; †¢ the cost of maintaining reusable libraries is prohibitive; †¢ management is not trained in software development methods with reuse; †¢ there is no coordination between software project partners to introduce reuse. Such problems of perception often result from irrational, nevertheless, deeply rooted myths about reusability and the reuse process. A selection of such myths (cf. Table 1) were reported and subsequently demistified by Tracz (1988a). Reuse motivators. While the common prejudice, miconceptions and outright myths among developers and management prevent companies to effectively introduce reuse into their mainstream development, Frakes and Fox (1995) show in their survey that only few factors listed above have any real impact on the success or failure of software reuse, i.e. †¢ the type of application domain althought the reasons for this phenomenon are not known, it seems that certain types of industries show significantly higher levels of reuse (e.g. telecommunication companies) in certain areas of the life-cycle than others (e.g. aerospace industries); †¢ perceived economic feasibility in those organisations where management convinced its software developers that reuse is desirable and economically viable had a much higher success in the introduction of reuse into those organisations; †¢ high quality and functional relevance of reuse assets increases the likelihood of the assets to be reused; †¢ common software process although developers themselves do not regard a common software process as promoting reuse, there is a strong correlation between the gains in the process maturity and the gains in the level of software reuse; and finally, †¢ reuse education education about reuse, both in school and at work, improves reuse and is a necessary part of a reuse program, however, since the issues of software reuse are rarely discussed in the academic curriculum, it is necessary for management to bear the responsibility to provide reuse-specific training to its employees. The same study also showed that other factors, widely perceived as reuse motivators or inhibitors, have only a minimal effect on the reuse process, e.g. †¢ use of specific programming languages and paradigms it is often perceived that structured, modular, object-oriented, or high-level languages improve the prospects of successful software reuse, the collected statistics, however, show no such correlation; †¢ utilisation of software support environments and CASE although development tools are frequently marketted as greatly enhancing software reusability, some studies show that the current employed CASE tools are not particularly effective in promoting reuse of life-cycle objects across projects in an organisation; †¢ employment of staff experienced in software engineering it seems to be evident that experienced software development practitioners are potentially better reusers than those who have no formal training in software engineering, however contrary to this belief, it can be shown that experience and knowledge of software development principles is not a substitute for training in methods and techniques specific to reuse activities; †¢ provision of recognition rewards as an incentive to promote reuse practices in the organisation it is likely that only monetary rewards are a more effective motivator for implementing reuse practices; †¢ existence of perceived legal impediments to the utilisation of reusable software as majority of reuse efforts concentrates on the in-house development of reusable artefacts, thus, the legal issues are of less concern; †¢ existence of reuse repositories many organisations consider such repositories as central to their reuse efforts, practice, however, shows that those organisations which do not use sophisticated computer-aided tools assisting the classification and retrieval of software artefacts achieve similar levels of reuse as those who are active proponents and users of such automated repositories; †¢ the size of an organisation conducting a software development project the project or development team size is often used as an argument against the introduction of a formal reuse process, small companies believe the narrow scope of their application domain will limit the potential benefit of reuse, while the big companies fear the necessary investment of resources and money to properly implement systematic reuse, the apprehension in both of these cases in unwarranted and the likelyhood of a success or failure of reuse efforts is independent of the company or project size; †¢ considerations of software and process quality majority of surveyed developers had generally positive experience in reusing various software assets developed outside their home companies, overall, the quality concerns had little impact on the level of software reuse, the situation would probably be very different if the quality of reused assets were to deteriorate; †¢ reuse measurements in majority of companies measurement of reuse levels, software quality, and software productivity are not done, however, those organisation which measure software reusability are not getting any significant higher reuse levels than those which fail to monitor their successes or failures in reusing software artefacts, thus in practice, measuring software reuse has very little effect on the whole of the reuse process. Finally, Krueger (1989) provides four tenets of the successful software reuse, the tenets based on the technical and cognitive factors which he believes will ultimately translate into variety of development goals to achieve an effective policy on software reusability, i.e. †¢ reuse must reduce the cognitive effort of software development; †¢ constructing systems of reusable components must be easier than to building them from scratch; †¢ finding reusable artefacts must be more efficient than building them; †¢ understanding artefacts is fundamental to their effective selection. Summary This paper defined the concepts of software reuse, reusability, reuse artefact and reuse library. It listed those attributes of software artefacts which increase a chance of them being reused, e.g. they have to be expressive, definite, transferable, additive, formal, machine representable, self-contained, language independent, able to represent data and procedures, verifiable, simple, and easily changeable. Then the paper gave an overview of major reuse efforts in the life-cycle, starting with coding and design, and then going through specification and requirements capture, and finally covering domain analysis and modelling. Two forms of reuse-based development were discussed, i.e. development-for-reuse, aiming at the construction of reuse library, and consisting of artefact identification, generalisation, classification and storage; and the second, development-by-reuse, aiming at the construction of a new software product with the use of reuse library, and including the tasks of searching for reusable artefacts, their understanding, adaptation to new requirements, and their integration into a new system. The stages of artefacts processing include their analysis, organisation and synthesis. Finally the paper analyses the benefits and the perceived disadvantages of software reusability, focusing in particular on the myths and misconceptions held by developers and their managers. Four preconditions for reusability success were given as reduction in cognitive complexity, ease of implementation, ability to understanding of artefact structure and function, and finally, economy of reuse. 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