An object oriented multi-robotic graphic simulation environment for programming the welding tasks

An object oriented multi robotic graphic simulation environment is described in this paper. Object oriented programming is used to model the physical objects of the robotic workcell in the form of software objects or classes. The virtual objects are defined to provide the user with a user friendly interface including realistic graphic simulation and clarify the software architecture. The programming method of associating the task object with active object effectively increases the software reusability, maintainability and modifiability. Task level programming is also demonstrated through a multi robot welding task that allows the user to concentrate on the most important aspects of the tasks. The multi thread programming technique is used to simulate the interaction of multiple tasks. Finally, a virtual test is carried out in the graphic simulation environment to observe design and program errors and fix them before downloading the software to the real workcell.

Diagnosing Student Learning Problems in Object Oriented Programming

Students often face difficulties while taking basic programming courses due to several factors. In response, research has presented subjective assessments for diagnosing learning problems to improve the teaching of programming in higher education. In this paper, the authors propose an Object Oriented conceptual map model and organize this approach into three levels： constructing a Concept Effect Propagation Table, constructing Test Item-Concept Relationships and diagnosing Student Learning Problems with Matrix Composition. The authors＇ work is a modification of the approaches of Chert and Bai as well as Chu et al., as the authors use statistical methods, rather than fuzzy sets, for the authors＇ analysis. This paper includes a statistical summary, which has been tested on a small sample of students in King Abdulaziz University, Jeddah, Saudi Arabia, illustrating the learning problems in an Object Oriented course. The experimental results have demonstrated that this approach might aid learning and teaching in an effective way.

Feature-based and objectoriented product information model for welding structure

Product information model for welding structure plays an important role for the integration of welding CAD/CAPP/CAM. However, existing CAD modeling systems are not capable of providing enough information for subsequent manufacturing activities such as CAPP and CAM. A new design approach using feature technique and object oriented programming method is put forward in this paper in order to create the product information model of welding structure. With this approach, the product information model is able to effectively support computer aided welding process planning, fixturing, assembling, path planning of welding robot and other manufacturing activities. The feature classification and representing scheme of welding structure are discussed. A prototype system is developed based on feature and object oriented programming. Its structure and functions are given in detail.

Dynamic Slicing of Object Oriented Programs

Program slice has many applications such as program debugging, testing, maintenance, and complexity measurement. A static slice consists of all statements in program P that may effect the value of variable v at some point p , and a dynamic slice consists only of statements that influence the value of variable occurrence for specific program inputs. In this paper, we concern the problem of dynamic slicing of object oriented programs which, to our knowledge, has not been addressed in the literatures. To solve this problem, we present the dynamic object oriented dependence graph (DODG)which is an arc classified digraph to explicitly represent various dynamic dependence between statement instances for a particular execution of an object oriented program. Based on the DODG, we present a two phase backward algorithm for computing a dynamic slice of an object oriented program.

Object-Oriented Design for FDTD Visual Scientific Computing

A scheme for general purposed FDTD visual scientific computing software is introduced in this paper using object-oriented design (OOD) method. By abstracting the parameters of FDTD grids to an individual class and separating from the iteration procedure, the visual software can be adapted to more comprehensive computing problems. Real-time gray degree graphic and wave curve of the results can be achieved using DirectX technique. The special difference equation and data structure in dispersive medium are considered, and the peculiarity of parameters in perfectly matched layer are also discussed.

Application of Petri Net to Fault Diagnosis in Satellite

A prototype of fault diagnosis based on Petri net, which is developed for a satellite tele-control subsystem, is introduced in this paper. Its structure is first given with the emphasis on a Petri net modeling tool which is designed using the object oriented method. The prototype is connected to the database with DAO (Date Access Object) technique, and makes the Petri net's firing mechanism and its analyzing methods to be packed up as DLL (Dynamic Link Library) documents. Compared with the rule-based expert system method, the Petri net-based one can store the knowledge in mathematical matrix and make inference more quickly and effectively.

CORBA-Based Discrete Event Simulation System

The CORBA technique is an integration of the object-oriented conception and distributed computing technique. It can make the application within distributed heterogeneous environments reusable, portable and interoperable. The architecture of CORBA-based discrete event simulation systems is presented and the interface of distributed simulation objects (DSO) is defined in this paper after the DSO is identified and the synchronization mechanism among DSO is discussed.

Building an E-business System Using Enterprise JavaBeans Architecture

This paper provides an overview of using Enterprise JavaBeans to build an e-business system. First, the authors point out some difficulties during building an e-business sy stem. For example, how can we integrate all kinds of software and hardware i n company quickly and economically Then the authors introduce a representative EJB structure and currently EJB deve loping approaches. A representative EJB structure includes an EJB Server, EJB Co ntainers, EJB Clients and JNDI etc. An EJB Server is similar to CORBA ORB. It pr ovides system services such as original implementing environment, multiprocessin g, workload management, equipment accessing, JTS and JNDI service and making the EJB Container visible. The EJB Container plays the role of interface between th e EJB and others. An EJB Client never accesses Bean directly. There are two kind s of containers. One is session contain, it mainly includes brief, impermanent E JB(thus all statuses will not be saved). The other is entity container which inc luding permanent EJB. The EJB Client uses EJB Beans. First it finds EJB Containe r through JNDI interface. Then it transfers EJB methods using EJB Container. Current, EJB developing approaches include several major aspects such as develop ment, deployment, application programs assembling and management of Enterprise B ean etc. Above all, we should define three classes, Bean class, home interface c lass of Bean and remote interface class of Bean. Then we should create a deploym ent descriptor. This is an XML documentation, which declared the properties of E nterprise Bean and bound the class documentations of Bean(including stub documen tation and skeleton documentation). And then we put these deployments into a jar documentation and define environment properties in the deployer. Next, we shoul d assemble application programs including install Enterprise Beans to server and test the connecting of each ties. The program assembler integrates several Ente rprise Beans with other beans(like Servlet, Applet, Script etc) into an integrat ed application program. It also may integrate several Enterprise Beans into a co mplicated Enterprise Bean. Of cause we also need to manage the Enterprise Bean. In the end, the authors point out several major advantages of using EJB to build e-business system such as simplifying application development and deployment, supporting heterogeneous client and server platforms, leveraging existing skills and assets, delivering a secure, scalable, reliable and manageable environment and providing the freedom to implement using many vendors’ products.

TrapML-A Metalanguage for Transformational Programming

This paper proposes a metalanguage TrapML for transformational programming, which is designed based on the analysis of its design principles, structures and functions. It has the facilities to describe the syntax of object languages, the set of transformation rules and strategies. The behaviour of transformation systems can be conveniently expressed. Both accurate and vague strategies can be written in TrapML. Metaprogram is of higher reliability.