Ok-Bae Chang

Analysis of metrics for object-oriented program complexity

We present a new framework for analyzing the scope of metrics to evaluate complexity of object-oriented programs. In this framework, we examine in detail the metrics from the viewpoint of three key aspects in object-oriented paradigm: syntax complexity, inheritance complexity and interaction complexity. For each key aspect, we expand it to five attributes, which can be calculated qualitatively. Then, we apply our framework to conventional metrics for evaluating complexity of object-oriented programs. The metrics include the ones proposed by S.R. Chidamber and C.F. Kemerer (1991), R.C. Sharble and S.S. Cohen (1993), W. Li and S. Henry (1993), and E. Kim (1993). Finally, we present a new metric which satisfies almost all attributes of the proposed framework.<<ETX>>

Automatic indexing of news video for content-based retrieval

Since it is impossible to automatically parse a general video, we investigated an integrated solution for the content-based news video indexing and the retrieval. Thus, a specific structural video such as news video is parsed, because it is included both temporal and spatial characteristics that the news event with an anchor-person is iteratively appeared, a news icon and a caption are involved in some frame, respectively. To extract automatically the key frames by using the structured knowledge of news, the model used in this paper is consisted of the news event segmentation, caption recognition and search browser module. The following are three main modules represented in this paper: (1) The news event segmentation module (NESM) for both the recognition and the division of an anchor-person shot. (2) The caption recognition module (CRM) for the detection of the caption-frames in a news event, the extraction of their caption region in the frame by using split-merge method, and the recognition of the region as a text with OCR software. 3) The search browser module (SBM) for the display of the list of news events and news captions, which are included in selected news event. However, the SBM can be caused various searching mechanisms.

An extension of UML activity diagram for generation of XPDL document

Currently there are a variety of different tools that may be used to analyze, model, describe and document a business process. However, it is difficult to exchange the information of a business process created in different tools because of the distinct information formats used in different tools. The XML Process Definition Language(XPDL) forms a common interchange standard. Generally a business process model can be represented by the UML activity diagram, but there is a difficult task to directly generate an XPDL document from a business process model represented by the standard activity diagram. In the paper we will propose an approach to generate an XPDL document from a business process model represented by the extended UML activity diagram and provide an implementation for the approach.

COMPONENT CONTRACT-BASED INTERFACE SPECIFICATION TECHNIQUE USING Z

A simple contract contains formalizing preconditions, postconditions, and invariants. A contract describes the services that are provided by an object. In the component world, it is essential to describe correctly what services are provided by the components and how we can use them. Till now, interfaces are specified in IDL, which describes the syntactic aspect of interface. IDL cannot describe the semantic aspects and safety condition of a component that a client and a server must know how to use or implement it. In this paper, we use contracts specifying components and propose an interface specification technique to describe components as a contract(namely, component contract). We regard a components interface as contract and present which aspect to be specified for providing correct information of the components. This paper defines some definitions and describes operators such as cooperating components, component version, functional requirements, nonfunctional requirements, and performance measurements to specify components, and specifies them using Z scheme. Finally, we apply this interface specification technique to develop an e-commerce system.

Improved Fast Mode Decision Algorithm for Variable Macro Block Motion Compensation in H.264

H.264 is the latest international video coding standard and it can achieve considerably higher coding efficiency versus previous standards This is accomplished by an enhanced exploitation of the spatiotemporal correlation, such as various macro-block modes, variable block sizes for motion compensation, multiple reference frames, quarter-pixel motion accuracy, and various predictive direction modes for intra prediction. However, although such new encoding technology is the main factor in improving the encoding efficiency, it is simultaneously a highly complex factor. Therefore, the H264 standard is used widely in real applications where the speed elevation of these technologies is essential. The proposed fast motion vector search technique supports the fastest compensation of the variable size block motion that is suitable for the motion vector conclusions which comprise a significant proportion of the encoding complexity in this paper. In addition, a fast-mode decision algorithm capable of deciding various encoding optimal values of H.264 is proposed. Because the proposed fast mode decision algorithm is capable of deciding the mode early, the method enables the omission of the computational procedure of rate-distortion cost and the efficient operation of the motion vector search technique. The results presented here confirmed the achievement of a very high efficiency while decreasing the required number of calculations without incurring any significant encoding damage, thereby improving the existing algorithm by using the information of the surrounding block.

Application and evaluation of edge detection system employing the ADD

In order to detect and locate edge features precisely in real images we have developed an algorithm by introducing a nonlocal differentiation of intensity profiles called adaptive directional derivative (ADD), which is evaluated independently of varying ramp widths. In this paper, we first develop the edge detector system employing the ADD and then, the performance of the algorithm is illustrated by comparing the results to those from the Cannys edge detector.

Behavior modeling technique based on EFSM for interoperability testing

With the rapid growth of network technology, two or more products from different vendors are integrated and interact with each other to perform a certain function in the latest systems. However, there are cases where products from different vendors or even from the same vendor often do not interoperate properly. Thus, interoperability testing is considered as an essential aspect for correctness of integrated systems. Interoperability testing tests the ability of software and hardware on different machines from different vendors to share data. Existing researches about interoperability testing are usually focused on an optimal test scenario generation applying graph and automata theory. Most of these researches model communication system behavior using EFSM(Extended Finite State Machines) and use EFSM as an input of test scenario generation algorithm. There are many studies on systematic and optimal test cast generation algorithms using EFSM, but in these researches, the study for generating EFSM model, which is a foundation of test scenario generation, is not sufficient. This paper proposes an EFSM generation technique, which is a foundation of test scenario generation for more complete interoperability testing based on use case specification. The generated EFSM through the proposed technique in this paper can be used as an input of EFSM-based test scenario generation algorithm proposed in other studies.

Integrated Management Data Warehouse Development Process of Research Expenses in Enterprise Environment

The existing management job of research expenses has been divided into three parts： budget planning, budget draw-up, and exact settlement of budget. However, it caused some problems. Under this current circumstance it is required to obtain research expenses steadily, to operate efficiently and to use them clearly to solve such problems. As a result of a study on data warehouse development process of existing system integration company (Inmon, IBM) to reflect current trend described above, data warehouse development process of Inmon uses systematic and gradual access as a classical development cycle method. It causes overlap and feedback to the previous step in the process of each step Is requested. And another problem that it is difficult to toil what function refers and corrects data because functions and data are separated during performing development process at data warehouse development process of IBM is caused. Integrated management data warehouse development process of research expenses in the enterprise environment which applies UML at planning and analysis step, design step and implement and test step is suggested in this paper. Information retrieval agent uses existing budget plan DB, budget draw-up DB and budget settlement DB to find out information that a user wants to know. Information retrieval agent collects and saves information at integration database and information integration agent extracts, transports, transforms and loads the data. Information integration agent reduces a user`s efforts to access to a number of information sources and check each of them. It also screens out data that a user may not need. As a result, integrated management data warehouse development process of research expenses in the enterprise environment reflects a user`s requirements as much as possible and provides various types of information to make a decision which is needed to establish the policy of research expense management. It helps an end user approach his/her desired analysis information quickly and get various data from the comprehensive viewpoint rather than the fragmentary viewpoint. Furthermore, as it integrated three systems into one, it is possible to share data, to integrate the system, to reduce operating expenses and to simplify supporting environment for the decision making.

XSLT template design for generating the Web presentation layer

In Web-based information systems, separating business process logic from data and presentation logic creates a wide range of advantages. However, this separation is not easily achieved; even the data logic may be not separated from the presentation layer. Therefore it is necessary to define an abstract model for business processes, and then to map the model into a users dynamic interface using the logic separating strategy. We present a stylesheet method for recognizing the process by extending the XSLT (Extensible Stylesheet Language Transformations) in order to achieve logic separation. This discussion provides an abstract specification of the business process and a scheme that extracts business model factors and their interactions using a Petri-net notation to show the business model from the process point of view. This is an attempt to separate the user interaction from the business process, that is, the separating of the dynamic components of the interaction Web document from the process structure of the Web applications. As a result, the development of service-oriented Web sites is made very easy and can be changed without affecting the other modules by virtue of the modularization concept. This facilitates development and maintenance of Web applications in independent manner.

Interface design technique considering visual cohesion-rate by object unit

With the application development environment rapidly changing, the design of an interface that supports the complex interactions between humans and computers is required. In addition, profound knowledge of various fields is required to cover the requirements of different customers. Therefore, in this paper, we suggest an interface design technique that considers the cohesion-rate in each objects of user interface. To accomplish this, specific and detailed models to embody the user interface are presented on the basis of the following classification: 1) event object model, 2) task object model, 3) transaction object model, 4) form object model. If this detailed modeling work is performed, the visual cohesion of the prototype user interface can be improved and, on this basis, even unskilled designers can construct an improved user interface. Moreover, the proposed method promotes the understanding of the business process and reduces the frequency of system development.