Gandhi Engineering College,Bhubaneswar

Transcription

1 CSE TECH-NEWS 2016 Gandhi Engineering College,Bhubaneswar 1

2 VISION: The Computer Science and Engineering department of Gandhi Engineering College aims to impart high quality technical education and promote values, so as to empower students to be technologically adept, innovative, self- motivated and responsible citizen of the nation. MISSION: 1. To provide engineering graduates a strong theoretical and practical background with an emphasis on research and software development. 2. To impart engineering graduates the ability necessary to continue education and to grow professionally in the field of higher education and research. 3. To cater to the technological need of emerging challenges of society and academia in specific. 4. To inculcate professional behaviour, strong ethical values, and leadership abilities among graduates. PROGRAM EDUCATIONAL OBJECTIVE: PEO1:(Technical proficiency and Career prospective) To Prepare the student for entry into successful employment as software engineer in industry, service, consulting, and/or government organization or for advanced study at leading post graduate school in engineering, business, management, or other technical and non-technical fields. PEO2: (Team Work and Leadership Skill) To encourage the teamwork skill among the students to design and implement complex software systems, particularly the ability to work with people from other fields in integrated engineering teams and develop the leadership skills for maximizing the performance of those teams. PEO3:(Continuous Learning) To inculcate the habit of life long self learning and being educated to have the attitude to communicate effectively in professional fields and become an integral part in societal development. PROGRAM SPECIFIC OBJECTIVE PSO-1: (Professional Skill) Able to create awareness and provide consultancy on emerging fields of Computer Science and Engineering. PSO-2: (Entrepreneurship) Able to establish service providing institutions on his/her own and generate employment. 2

3 DEPARTMENT MAGAZINE 3

4 CONTENTS Topics Page Nos. 1. About the Department 3 2. Editor s Column 3 3. Arts 4 4. Quotes 5 5. Biography 6 6. Literature Desk Techie Articles Refreshing Fundamental Inspiring Lines Test your programming skills The lighter side (Technology) Contributors 29 4

5 About the Department The vision of the CSE department at GEC is to consistently strive for achieving excellence in the computing world. It is being perusal through its spectrum of academic components in computing of contemporary standards. The continues effort to produce quality computer professionals with potential to design and develop software systems across various disciplines and become good human being for the societal development. At present our department has 29 teaching staffs and 480 numbers of students in total. We have a very good infrastructure of nine (09) laboratories with requisite software and well equipped class rooms, seminar room, conference room etc. We have also got Wi-Fi enable campus including connectivity in five hostels. (HoD) Editorial Hello Readers! Welcome to the start of an exciting journey into the world of computer science. This magazine delves into branch of computer science that you could possibly imagine, from the art of stories to riddle to advancement of the field of computer science. We have this inherent curiosity of knowing about and understanding the working of science related to the world of computers. Through this magazine we hope to answer some of the questions that might pop up in your mind like it does for us, and far more importantly, act as a stimulus for raising further questions about the daily phenomena we tend to dismiss as mundane and boring. Take for example, a ball rolling on the ground. To normal people is something you see every day but for us it is a paradise of complex equations that go a long way into understanding why the ball rolls. That s why we made this magazine to make you ask Why -the most important question in science. We would like to thank you for reading this magazine and more importantly, we hope that you will have as much fun in reading this magazine as we had in making it for you. 5

6 Arts 6

7 Quotes 7

8 Alan Turing Biography The Origins of Alan Turing Alan Mathison Turing was born on 23 June 1912, the second and last child (after his brother John) of Julius Mathison and Ethel Sara Turing. The unusual name of Turing placed him in a distinctive family tree of English gentry, far from rich but determinedly upper-middle-class in the peculiar sense of the English class system. His father Julius had entered the Indian Civil Service, serving in the Madras Presidency, and had there met and married Ethel Sara Stoney. She was the daughter of the chief engineer of the Madras railways, who came from an Anglo-Irish family of somewhat similar social status. Although conceived in British India, most likely in the town of Chatrapur, Alan Turing was born in a nursing home in Paddington, London. In four inadequate words Alan Turing appears now as the founder of computer science, the originator of the dominant technology of the late twentieth century, but these words were not spoken in his own lifetime, and he may yet be seen in a different light in the future. They are also words very remote from the circumstances of his birth and infancy. The name of Turing was best known for the work of Julius' brother H. D. Turing on fly fishing, and had no connection with the scientific or academic worlds. The name of Stoney however was notable for a remote relative, the Irish physicist George Johnstone Stoney ( ), today best known for his identification of the natural units of physical quantities. Possibly the engineering base of his mother's family, with its respect for applied science, had some influence, but if so it was subordinated to the demands of class, church and Empire. Certainly the elder brother John F. Turing, who became a London 8

9 solicitor, showed no sign of it. Alan Turing's story was not one of family or tradition but of an isolated and autonomous mind. His boyhood scientific interests were a trial to his mother whose perpetual terror was that he would not be acceptable to the English Public School. At twelve he expressed his conscious fascination with using 'the thing that is commonest in nature and with the least waste of energy,' presentiment of a life seeking freshly minted answers to fundamental questions. Despite this, he was successfully entered for Sherborne School. The headmaster soon reported: "If he is to be solely a Scientific Specialist, he is wasting his time at a Public School." The assessment of his establishment was almost correct. The Turing machine This triple correspondence between logical instructions, the action of the mind, and a machine which could in principle be embodied in a practical physical form, was Turing's definitive contribution. Having made this novel definition of what should count as a 'definite method' in modern language, an algorithm it was not too hard to answer Hilbert's question in the negative: no such decision procedure exists. In April 1936 he showed his result to Newman; but at the same moment the parallel conclusion of the American logician Alonzo Church became known, and Turing was robbed of the full reward for his originality. His paper, On Computable Numbers with an application to the Entscheidungsproblem, had to refer to Church's work, and was delayed until August However it was seen at the time that Turing's approach was original and different; Church relied upon an assumption internal to mathematics, rather than appealing to operations that could actually be done by real things or people in the physical world. 9

10 Subsequently, the concept of the Turing machine has become the foundation of the modern theory of computation and computability. His work introduced a concept of immense practical significance: the idea of the Universal Turing Machine. The concept of 'the Turing machine' is like that of 'the formula' or 'the equation'; there is an infinity of possible Turing machines, each corresponding to a different 'definite method' or algorithm. But imagine, as Turing did, each particular algorithm written out as a set of instructions in a standard form. Then the work of interpreting the instructions and carrying them out is itself a mechanical process, and so can itself be embodied in a particular Turing machine, namely the Universal Turing machine. A Universal Turing machine can be made do what any other particular Turing machine would do, by supplying it with the standard form describing that Turing machine. One machine, for all possible tasks. Emergence of the Computer Building a Brain Turing's detailed computer scheme was drawn up in a continuation of wartime spirit: as a plan that could be effected immediately with the memory storage (cumbersome acoustic delay lines, as used in radar) that was to hand. Turing knew that superior technology would soon transform design: his emphasis was on speed in every sense, and in the exploitation of the universal machine concept. This meant, in particular, implementing arithmetical functions by programming rather than by building in electronic components, a concept different from that of the American-derived designs. He was found by his cleaner when she came in on 8 June He had died the day before of cyanide poisoning, a half-eaten apple beside his bed. His mother 10

11 believed he had accidentally ingested cyanide from his fingers after an amateur chemistry experiment, but it is more credible that he had successfully contrived his death to allow her alone to believe this. The coroner's verdict was suicide. 11

12 Literature Desk The Tempest by Shakespeare (summerization) The Tempest opens in the midst of a storm, as a ship containing the king of Naples and his party struggles to stay afloat. On land, Prospero and his daughter, Miranda, watch the storm envelop the ship. Prospero has created the storm with magic, and he explains that his enemies are on board the ship. The story Prospero relates is that he is the rightful Duke of Milan and that his younger brother, Antonio, betrayed him, seizing his title and property. Twelve years earlier, Prospero and Miranda were put out to sea in little more than a raft. Miraculously, they both survived and arrived safely on this island, where Prospero learned to control the magic that he now uses to manipulate everyone on the island. Upon his arrival, Prospero rescued a sprite, Ariel, who had been imprisoned by the witch Sycorax. Ariel wishes to be free and his freedom has been promised within two days. The last inhabitant of the island is the child of Sycorax and the devil: Caliban, whom Prospero has enslaved. Caliban is a natural man, uncivilized and wishing only to have his island returned to him to that he can live alone in peace. Soon the royal party from the ship is cast ashore and separated into three groups. The king's son, Ferdinand, is brought to Prospero, where he sees Miranda, and the two fall instantly in love. Meanwhile, Alonso, the king of Naples, and the rest of his party have come ashore on another part of the island. Alonso fears that Ferdinand is dead and grieves for the loss of his son. Antonio, Prospero's younger brother, has also been washed ashore with the king's younger brother, Sebastian. Antonio easily convinces Sebastian that Sebastian should murder his brother and seize the throne for himself. This plot to murder Alonso is similar to Antonio's plot against his own brother, Prospero, 12 years earlier. Another part of the royal party the court jester and the butler has also come ashore. Trinculo and Stefano each stumble upon Caliban, and each immediately sees a way to make money by exhibiting Caliban as a monster recovered from this uninhabited island. Stefano has come ashore in a wine cask, and soon Caliban, Trinculo, and Stefano are drunk. While drinking, Caliban hatches a plot to murder Prospero and enrolls his two new acquaintances as accomplices. Ariel is listening, however, and reports the plot to Prospero. Meanwhile, Prospero has kept Ferdinand busy and has forbidden Miranda to speak to him, but the two still find time to meet and declare their love, which is actually what Prospero has planned. Next, Prospero stages a masque to 12

13 celebrate the young couple's betrothal, with goddesses and nymphs entertaining the couple with singing and dancing. While Ferdinand and Miranda have been celebrating their love, Alonso and the rest of the royal party have been searching for the king's son. Exhausted from the search and with the king despairing of ever seeing his son alive, Prospero has ghosts and an imaginary banquet brought before the king's party. A god-like voice accuses Antonio, Alonso, and Sebastian of their sins, and the banquet vanishes. The men are all frightened, and Alonso, Antonio, and Sebastian run away. Prospero punishes Caliban, Trinculo, and Stefano with a run through a briar patch and swim in a scummy pond. Having accomplished what he set out to do, Prospero has the king's party brought in. Prospero is clothed as the rightful Duke of Milan, and when the spell has been removed, Alonso rejects all claims to Prospero's dukedom and apologizes for his mistakes. Within moments, Prospero reunites the king with his son, Ferdinand. Alonso is especially pleased to learn of Miranda's existence and that Ferdinand will marry her. Prospero then turns to his brother, Antonio, who offers no regrets or apology for his perfidy. Nevertheless, Prospero promises not to punish Antonio as a traitor. When Caliban is brought in, Caliban tells Prospero that he has learned his lesson. His two co-conspirators, Trinculo and Stefano, will be punished by the king. Soon, the entire party retires to Prospero's cell to celebrate and await their departure home. Only Prospero is left on stage. In a final speech, Prospero tells the audience that only with their applause will he be able to leave the island with the rest of the party. Prospero leaves the stage to the audience's applause The Tempest opens in the midst of a storm, as a ship containing the king of Naples and his party struggles to stay afloat. On land, Prospero and his daughter, Miranda, watch the storm envelop the ship. Prospero has created the storm with magic, and he explains that his enemies are on board the ship. The story Prospero relates is that he is the rightful Duke of Milan and that his younger brother, Antonio, betrayed him, seizing his title and property. Twelve years earlier, Prospero and Miranda were put out to sea in little more than a raft. Miraculously, they both survived and arrived safely on this island, where Prospero learned to control the magic that he now uses to manipulate everyone on the island. Upon his arrival, Prospero rescued a sprite, Ariel, who had been imprisoned by the witch Sycorax. Ariel wishes to be free and his freedom has been promised within two days. The last inhabitant of the island is the child of Sycorax and the devil: Caliban, whom Prospero has enslaved. Caliban is a 13

14 natural man, uncivilized and wishing only to have his island returned to him to that he can live alone in peace. Soon the royal party from the ship is cast ashore and separated into three groups. The king's son, Ferdinand, is brought to Prospero, where he sees Miranda, and the two fall instantly in love. Meanwhile, Alonso, the king of Naples, and the rest of his party have come ashore on another part of the island. Alonso fears that Ferdinand is dead and grieves for the loss of his son. Antonio, Prospero's younger brother, has also been washed ashore with the king's younger brother, Sebastian. Antonio easily convinces Sebastian that Sebastian should murder his brother and seize the throne for himself. This plot to murder Alonso is similar to Antonio's plot against his own brother, Prospero, 12 years earlier. Another part of the royal party the court jester and the butler has also come ashore. Trinculo and Stefano each stumble upon Caliban, and each immediately sees a way to make money by exhibiting Caliban as a monster recovered from this uninhabited island. Stefano has come ashore in a wine cask, and soon Caliban, Trinculo, and Stefano are drunk. While drinking, Caliban hatches a plot to murder Prospero and enrolls his two new acquaintances as accomplices. Ariel is listening, however, and reports the plot to Prospero. Meanwhile, Prospero has kept Ferdinand busy and has forbidden Miranda to speak to him, but the two still find time to meet and declare their love, which is actually what Prospero has planned. Next, Prospero stages a masque to celebrate the young couple's betrothal, with goddesses and nymphs entertaining the couple with singing and dancing. While Ferdinand and Miranda have been celebrating their love, Alonso and the rest of the royal party have been searching for the king's son. Exhausted from the search and with the king despairing of ever seeing his son alive, Prospero has ghosts and an imaginary banquet brought before the king's party. A god-like voice accuses Antonio, Alonso, and Sebastian of their sins, and the banquet vanishes. The men are all frightened, and Alonso, Antonio, and Sebastian run away. Prospero punishes Caliban, Trinculo, and Stefano with a run through a briar patch and swim in a scummy pond. Having accomplished what he set out to do, Prospero has the king's party brought in. Prospero is clothed as the rightful Duke of Milan, and when the spell has been removed, Alonso rejects all claims to Prospero's dukedom and apologizes for his mistakes. Within moments, Prospero reunites the king with his son, Ferdinand. Alonso is especially pleased to learn of Miranda's existence and that Ferdinand will marry her. 14

15 Prospero then turns to his brother, Antonio, who offers no regrets or apology for his perfidy. Nevertheless, Prospero promises not to punish Antonio as a traitor. When Caliban is brought in, Caliban tells Prospero that he has learned his lesson. His two co-conspirators, Trinculo and Stefano, will be punished by the king. Soon, the entire party retires to Prospero's cell to celebrate and await their departure home. Only Prospero is left on stage. In a final speech, Prospero tells the audience that only with their applause will he be able to leave the island with the rest of the party. Prospero leaves the stage to the audience's applause. 15

16 Techie Articles Planning in Games: An Overview and Lessons Learned (Reference: Alex J. Champandard on March 8, 2013) It's hard to ignore the potential of planning techniques for Game AI, and over the years they've drawn much attention from developers and researchers alike. In theory, planners could help build more intelligent non-player characters, and (indirectly) more believable and entertaining NPCs. Better still, planners as game directors or story generators could help craft unique experiences for each player. In practice, planning technology has made notable inroads in the past 8-10 years since being introduced in the games industry. There are certainly a lot of open problems to solve and many more questions left to answer, but much has been achieved already... In this article and its accompanying video, I'll dig into the history of planning in games, look at games that use planning as well as related techniques that have had an impact, and present the biggest lessons we've learned as a result of all this. STRIPS-based Planners STRIPS is a planning algorithm that searches through possible situations (or world states) by applying operators (or actions). Typically with STRIPS, this search is done backward from the goal state rather than forward from the 16

17 current world state; the first is faster, but the second is more flexible when you have complex goals. Using A* to drive the search with simple heuristics can help make the planning process relatively efficient. (This is only a short overview, but obviously it's a topic that has been studied for decades over hundreds of white papers.) F.E.A.R. is the first game known to use planning techniques, based on the work of Jeff Orkin. The enemy AI relies on a STRIPS-style planner to search through possible actions to find a world state that matches with the goal criteria. Monolith's title went on to spawn a franchise of sequels and expansions, and inspired many other games to use STRIPS-style planning too in particular the S.T.A.L.K.E.R. series, CONDEMNED, and JUST CAUSE 2. There aren't very many games that use such planners in comparison to other techniques, but the AI in those games has been well received by players and reviewers. The most successful games to use planning have featured more open worlds and emergent gameplay, whereas more heavily scripted or linear storydriven characters have conversely received poor reviews when implemented with STRIPS-style planners. In the past few years, we've seen an incremental shift away from STRIPS-style implementations towards more hierarchical approaches, either HTN planners or their reactive cousins behavior trees. HTN-based Planners 17

18 HTN planners are based on hierarchies of tasks that can be broken down recursively, like a plan that starts with the big picture and gets refined into actionable steps. Different HTN algorithms take different approaches to expanding the plan, for example starting from the current point in time and progressing one step at a time (a.k.a. ordered HTN). The ordered approach is more efficient though less flexible; partial order approaches are proven capable of emulating STRIPS for example. HTN-based planners inspired by SHOP (an ordered planner) are becoming increasingly popular over the STRIPS-based ones. Guerrilla Games implemented a planner inspired by SHOP into KILLZONE 2, and continues to use the technology in sequels including KILLZONE 3 and presumably 4. The bots in the series have continuously received praise from players and reviewers alike, thanks in part to the planning technology but also the richness of the domain. Recently, in TRANSFORMERS: WAR FOR CYBERTRON, High Moon also switched from using a STRIPS-based planner to a hierarchical approach also inspired by Guerrilla's work and SHOP. Behavior Trees It's often difficult to draw the line between hierarchical planners and behavior trees, since SHOP-inspired planners often include implementation tricks or design patterns to make them more reactive for the sake of performance. In 18

19 practice, this makes them very similar to the industry-standard behavior trees, which have been in heavy use since ~2004 (with ideas inspired from robotics and virtual agents from decades before). In practice, the AI in games like TOTAL WAR (e.g. EMPIRE or NAPOLEON) has been dubbed a planner but follows implementations traits of "reactive planners" and "belief-desire intention" architectures (both are misleading terms, despite having been used often in academic research). Similarly, games like METRO 2033 switched from STRIPS-style planners, and Avalanche studios is also currently favoring its behavior tree implementation despite having a production-quality STRIPS planner available. Utility Systems A utility system is the term used to describe a voting/scoring system, and they are often applied to sub-systems of games like selecting objects/positions based on the results of a spread-sheet like calculation. It's interesting to establish parallels between STRIPS-based planners and utility-based systems, since both have a strong emphasis on emergent behavior that's not intended to be controlled top-down by designers. 19

20 DEMIGOD in particular uses a form of action search that's not a planner in the traditional sense, trying to satisfy clear dependencies and meet Boolean conditions in the goal state, but instead trying to evaluate the benefit of short sequences of actions and pick the best one. This approach bridges the gap between utility systems and non-hierarchical planner, making utility systems more deliberate in the process. Another notable implementation is the one in the SIMS 3. The SIMS franchise is famous for its use of utility systems, but in the 3rd major iteration, the game puts more focus on a top-level hierarchy and keeps the utility-based decisions more isolated. This was necessary for performance reasons, but also makes the characters more purposeful. Lessons Learned Based on the applications in all these games, we've developed a much better understanding of planning in games: Technology has not been much of a problem. Applying STRIPS into a game in real-time certainly required many engineering and optimizations tricks, likewise speeding up HTN implementations. However, with additional processing power available and with much better knowledge of the problem since then, planning performance hasn't been as big of an issue as you'd expect it to be... The biggest open questions are about design. The most significant problems to solve have been finding ways to tweak and tune the behaviors resulting from planners, optionally integrating them with level scripts, and teaching designers to think more systematically and work with emergent AIs. This has required significantly more effort than the pure algorithmic aspects of planning, and is responsible for the incremental transition towards hierarchical approaches. In well understood domains, other techniques work best. In the cases of action/combat games, we can easily build robust AI that looks 20

21 deliberate using simple reactive techniques like behavior trees. In fact, it's difficult to tell the difference for such applications between the behavior generated by a planner compared to more reactive approaches, yet the planning process will be noticeably slower at runtime and require more development time. Planning has most benefits in unknown domains. Jeff Orkin mentioned in his publications that one of the benefits of planning was in prototyping, creating new behaviors quickly by letting the planner generate behavior given new actions or goals to work with. Planners also have shown to be more beneficial in open worlds, where the sandbox simulation has significantly more complexity. Goal-based architectures are great! Regardless of whether developers use planning techniques or not, an architecture that separates the AI's goals (or WHAT to do) and the AI's decision making (or HOW to do it), has proven to be very effective. Planning research has helped crystallize this insight, and even when using reactive techniques this is arguably a best practice for AI architecture in games today. Final Words We've barely scratched the surface of what planners have to offer for game development. We've certainly learned a lot, but at the same time there's such a small amount of research on topics that are problematic in games (e.g. design and workflow questions) that progress is slower than you'd expect for such a mature field as automated planning. Perhaps the most exciting prospect of planners, however, is their application to create new types of gameplay that would otherwise not be possible using any other approach. This part has proven to be more of a challenge, as few designers have the background in systems thinking that's required to come up with such ambitious and innovative designs. 21

22 Refreshing Fundamentals Operating System (point wise) Operating System is a Resource Manager. Handles multiple computer resources: CPU, Internal/External memory, Processes, Tasks, Applications, Users, etc Manages and allocates resources to multiple users or multiple jobs running at the same time (e.g., processor time, memory space, I/O devices) Arranges to use the computer hardware in an efficient manner (maximize throughput, minimize response time) and in a fair manner. It is a Control Program. Manages all the components of a complex computer system in an integrated manner. Controls the execution of user programs and I/O devices to prevent errors and improper use of the computer resources. Looks over and protects the computer. It is an extended/virtual machine An interface between the user and hardware that hides the details of the hardware (e.g., I/O). Constructs higher-level (virtual) resources out of lower-level (physical) resources (e.g., files). Definition: Is a collection of software enhancements, executed on the bare hardware, culminating in a high-level virtual machine that serves as an advanced programming environment 22

23 Why Operating System? Computer hardware is developed to execute user programs and make solving user problems easier. An operating system makes a computer more convenient to use. It acts as an interface between user and computer hardware. Therefore, the end-users are not particularly concerned with the computer s architecture, and they view the computer system in terms of an application. To programmers, it provides some basic utilities to assist him in creating programs, the management of files, and the control of I/O devices. Operating System Objectives Convenience Makes the computer more convenient to use Efficiency Allows computer system resources to be used in an efficient manner Ability to evolve 23

24 Permit effective development, testing, and introduction of new system functions without interfering with service Services Provided by Operating Systems Facilities for program creation Editors, compilers, linkers, debuggers, etc. Program execution Loading in memory, I/O and file initialization. Access to I/O and files Deals with the specifics of I/O and file formats. System access Resolves conflicts for resource contention. Protection in access to resources and data. Error detection and response internal and external hardware errors memory error device failure software errors arithmetic overflow access forbidden memory locations operating system cannot grant request of application Accounting collect statistics monitor performance used to anticipate future enhancements used for billing users Computer System Components A computer system can be divided in to four components. 24

25 The Hardware: Provides basic computing resources (CPU, memory, I/O devices). The Operating System: Controls and coordinates the use of the hardware among the various application programs for the various users. The Application Programs: Define the ways in which the system resources are used to solve the computing problems of the users (compilers, database systems, video games, business programs). The Users: Users (people, machines, other computers). These components can be viewed as layers, where each layer uses the services provided by the layer beneath it. A Static View of System Components 25

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27 Interview Questions in Java Dear friends, these Java Interview Questions have been designed especially to get you acquainted with the nature of questions one may encounter during interview for the subject of Java Programming Language: 1. What do you know about Java? 2. What are the supported platforms by Java Programming Language? 3. List any five features of Java? 4. Why is Java Architectural Neutral? 5. How Java enabled High Performance? 6. Why Java is considered dynamic? 7. What do you mean by Object? 8. Define class? 9. What kind of variables a class can consist of? 10. What is a Local Variable? 11. What is a Instance Variable? 12. What is a Class Variable? 13. What is Singleton class? 14. What do you mean by Constructor? 15. List the three steps for creating an Object for a class? 16. What is the default value of byte datatype in Java? 17. What is the default value of float and double datatype in Java? 18. When a byte datatype is used? 19. What is a static variable? 20. What do you mean by Access Modifier? 21. What is protected access modifier? 22. What do you mean by synchronized Non Access Modifier? 23. Why is StringBuffer called mutable? 24. What is the difference between StringBuffer and StringBuilder class? 25. What is an Exception? 27

28 26. What do you mean by Checked Exceptions? 27. Explain Runtime Exceptions? 28. Which are the two subclasses under Exception class?when throws keyword is used? 29. When throw keyword is used? 30. How finally used under Exception Handling? 31. What is an Interface? 32. Give some features of Interface? 33. Define Packages in Java? 34. What is an applet? 35. An applet extend which class? 36. Explain garbage collection in Java? 37. What is the difference between inner class and nested class? 38. What restrictions are placed on method overriding? 39. What is constructor chaining and how is it achieved in Java? 28

29 Introduction to Animation The Lighter Side Computer Animation is one of the exciting of the multitude of applications spawned by the advent of computers. Animation can make a series of dead images come alive. It is possible to categorize animation into various types Stick figure animation Cartoons Human like figure Animation Among all of the above, animating the human face is the most difficult task as each human face is unique and generating a life like representation of the face is really difficult. The Human Face is a complex object which can be easily represented in two dimensions on a computer. However, to obtain a three dimensional representation of the same is an intricate task. There are three steps in the animation of the human face Developing the model for the face Modifying the facial expression Generating the images There are three approaches to facial animation Key Frame animation This requires complete specification of the model for each facial expression. The key frame for these expressions are different for individual frames. 29

30 An example of Key Frame Animation Parameterisation In this model proposed by Parke and then by Waters, sets of parameters define the conformation in the expression of the face. However, the transformation specified by these parameters being rather global, it is difficult to model complex expressions. Parke's model Muscle based modeling In this method, suggested by Platt and Badler, muscles are geometric deformation operators. Many muscle units and their parameter values must be specified to simulate natural expression. Water's model 30

31 Contributors: 31