• Korean Journal of Agricultural and Forest Meteorology
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• v.20 no.2
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• pp.214-227
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• 2018

An object oriented crop model was developed to perform crop growth simulation taking into account complex interaction between biotic and abiotic factors in an agricultural ecosystem. A set of classes including Atmosphere class, Plant class, Soil class, and Grower class were designed to represent weather, crop, soil, and crop management, respectively. Objects, which are instance of class, were linked to construct an integrated system for crop growth simulation. In a case study, yield of corn and soybean, which was obtained at an experiment farm in Rural Development Administration from 1984 to 1986, were compared with yield simulated using the integrated system. The integrated system had relatively low error rate of corn yield, e.g., <4%, under sole and intercropping conditions. In contrast, the system had a relatively large underestimation error for above ground biomass except for grain compared with those observed for corn and soybean. For example, estimates of biomass of corn leaf and stem was 31% lower than those of observed values. Although the integrated system consisted of simple models, the system was capable of simulating crop yield under an intercropping condition. This result suggested that an existing process-based model would be used to have more realistic simulation of crop growth once it is reengineered to be compatible to the integration system, which merits further studies for crop model improvement and implementation in object oriented paradigm.

• Journal of the Korean Institute of Telematics and Electronics C
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• v.36C no.4
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• pp.31-43
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• 1999

The main goal of this paper is to design a high performance SVP(Stack based Video Processor) for network applications. The SVP is a comprehensive scheme; 'better' in the sense that it is an optimal selection of previously proposed enhancements of a stack machine and a video processor. This can process effectively object-based video data using a S-RISC(Stack-based Reduced Instruction Set Computer) with a semi -general-purpose architecture having a stack buffer for OOP(Object-Oriented Programming) with many small procedures at running programs. And it includes a vector processor that can improve the MPEG coding speed. The vector processor in the SVP can execute advanced mode motion compensation, motion prediction by half pixel and SA-DCT(Shape Adaptive-Discrete Cosine Transform) of MPEG-4. Absolutors and halfers in the vector processor make this architecture extensive to a encoder. We also designed a VLSI stack-oriented video processor using the proposed architecture of stack-oriented video decoding. It was designed with O.5$\mu\textrm{m}$ 3LM standard-cell technology, and has 110K logic gates and 12 Kbits SRAM internal buffer. The operating frequency is 50MHz. This executes algorithms of video decoding for QCIF 15fps(frame per second), maximum rate of VLBV(Very Low Bitrate Video) in MPEG-4.

• Journal of the Korean Society for Railway
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• v.6 no.4
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• pp.221-231
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• 2003

Most rail system related simulators currently used are designed to simulate only one discipline system. This obviously assumes the other discipline systems are running regularly not being affected by the system being simulated. In this paper a multi discipline simulator is proposed and its design concept is presented. A multi discipline simulator is the simulator in which major subsystems with different technical discipline are simulated simultaneously. The advantage of the simulator is in that it makes it possible to analyze the systems behavior while other discipline system vary. With this we can identify the possible multi-discipline problems and even find their solutions. A proto type simulator has been developed using object oriented programming. Object concept was judged best suitable to model the various multi-discipline self-controlling railway subsystems. It was applied to the target system, which is under development by the Korea Railroad Research Institute. The test results shows it is very useful in designn verification. It could also be a good tool in research and development work to improve the system.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 1999.05a
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• pp.230-234
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• 1999

Inheritance and concurrency are the primary feature of object oriented languages, and are especially important for code re-use. They provide maximum computational power and modeling power through concurrency of objects. But, concurrent objects and inheritance have conflicting characteristics, thereby simultaneously use of them causes the problem, so failed inheritance anomaly, which requires code redefinition of inherited methods to maintain integrity of objects. In this paper, to solve the inheritance anomaly problems we introduce concept of state abstraction, in which infernal states of encapsulated objects are made available from a part of object's external interface. And we design inheritance interface mechanisms which methods are inherited efficiently. In our scheme, we can solve the typical inheritance anomaly problems.

• Journal of Computing Science and Engineering
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• v.1 no.1
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• pp.56-73
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• 2007

Demands have been growing in safety-critical application fields for producing networked real-time embedded computing (NREC) systems together with acceptable assurances of tight service time bounds (STBs). Here a service time can be defined as the amount of time that the NREC system could take in accepting a request, executing an appropriate service method, and returning a valid result. Enabling systematic composition of large-scale NREC systems with STB certifications has been recognized as a highly desirable goal by the research community for many years. An appealing approach for pursuing such a goal is to establish a hard-real-time (HRT) component model that contains its own STB as an integral part. The TMO (Time-Triggered Message-Triggered Object) programming scheme is one HRT distributed computing (DC) component model established by the first co-author and his collaborators over the past 15 years. The TMO programming scheme has been intended to be an advanced high-level RT DC programming scheme that enables development of NREC systems and validation of tight STBs of such systems with efforts far smaller than those required when any existing lower-level RT DC programming scheme is used. An additional goal is to enable maximum exploitation of concurrency without damaging any major structuring and execution approaches adopted for meeting the first two goals. A number of previously untried program structuring approaches and execution rules were adopted from the early development stage of the TMO scheme. This paper presents new concrete justifications for those approaches and rules, and also discusses new extensions of the TMO scheme intended to enable further exploitation of concurrency in NREC system design and programming.

• Journal of KIISE:Computing Practices and Letters
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• v.6 no.2
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• pp.120-134
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• 2000

In this paper we present a Distributed Object oriented Virtual computing Environment, called DOVE which consists of autonomous distributed objects interacting with one another via method invocations based on a distributed object model. DOVE appears to a user logically as a single virtual computer for a set of heterogeneous hosts connected by a network as if objects in remote site reside in one virtual computer. By supporting efficient parallelism, heterogeneity, group communication, single global name service and fault-tolerance, it provides a transparent and easy-to-use programming environment for parallel applications. Efficient parallelism is supported by diverse remote method invocation, multiple method invocation for object group, multi-threaded architecture and synchronization schemes. Heterogeneity is achieved by automatic data arshalling and unmarshalling, and an easy-to-use and transparent programming environment is provided by stub and skeleton objects generated by DOVE IDL compiler, object life control and naming service of object manager. Autonomy of distributed objects, multi-layered architecture and decentralized approaches in hierarchical naming service and object management make DOVE more extensible and scalable. Also,fault tolerance is provided by fault detection in object using a timeout mechanism, and fault notification using asynchronous exception handling methods

• The KIPS Transactions:PartD
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• v.9D no.5
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• pp.847-858
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• 2002

A purpose of the object-oriented programming is to promote reuse and development time, and to improve software quality. A way for this purpose is using a design information well-defined and tested in previous time when developing software. Such design information is called design patterns. The design patterns are descriptions of abstract solution to recurse software design problems In a systematic and general way. But because the design patterns are descriptions of abstract solution, the specification and application of patterns generally rely on manual implementation and is applied to various forms. As a result, we need to spend a lot of time to develop software program not only because of difficulty in analyzing and applying to patterns consistently, but also because of the frequent programing faults. And because the applied design patterns don't express inside application visually, it is difficult to analyze and test for this design patterns. In this paper, we propose automatic source code generating technique to be able to efficiently apply the element of design patterns when developing application. And we show a way to analyze and use the applied design patterns in application. As a result, the design patterns in application provide the consistent structure and efficiency, and make analysis and using effect increased.

• Journal of Energy Engineering
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• v.11 no.3
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• pp.194-202
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• 2002

In this paper, we simulate the power system transient stability of Kwang Yang steel works using object-oriented programming (OOP). OOP is a more flexible method than procedural programming. There are several advantages in dynamic system simulation using OOP, The maintenance and repair of program are easy because it is sufficient to modify necessary parts which correspond to the change of system without overall change of program. We have implemented a graphical man-machine interface (MMI) that can be used draw one-line system diagram and analyze power flow and dynamic stability. The implemented MMI also provide a graphical viewer that display dynamic stability analysis results by mouse event handling. The proposed method have been applied to Kwang Yang steel works network for on-line dynamic stability analysis. The dynamic behaviour of 17 synchronous generators and 25 synchronous motors has been studied in the Kwang Yang network.

• Journal of the Korea Society for Simulation
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• v.11 no.2
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• pp.1-16
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• 2002

The need for network security is being increasing due to the development of information communication and internet technology. In this paper, firewall models, operating system models and other network component models are constructed. Each model is defined by basic or compound model, referencing DEVS formalism. These models and the simulation environment are implemented with MODSIM III, a general purpose, modular, block-structured high-level programming language which provides direct support for object-oriented programming and discrete-event simulation. In this simulation environment with representative attacks, the following three attacks are generated, SYN flooding and Smurf attack as an attack type of denial of service, Mail bomb attack as an attack type of e-mail. The simulation is performed with the models that exploited various security policies against these attacks. The results of this study show that the modeling method of packet filtering system, proxy system, unix and windows NT operating system. In addition, the results of the simulation show that the analysis of security performance according to various security policies, and the analysis of correlation between availability and confidentiality according to security empowerment.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.8 no.6
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• pp.1530-1536
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• 2007

In this paper, a mobile banking system which can provide banking services is introduced. Since a PDA has excellent features like a small-size computer and provides mobility, it has been widely used by salesmen. Therefore, if general banking services can be provided with PDA by using wireless technology, it will be very useful. In addition, it is easy to develop and maintain the client software of PDA because it uses Windows-based operation systems. In this paper, a PDA banking system is introduced. The system is designed and developed based on the techniques of wireless network, security and PDA programming to be used for mobile banking and a prototype system is developed. Moreover, we used the object-oriented modeling technique, UML and Java Beans for programming.