• Journal of Communications and Networks
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• v.7 no.3
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• pp.263-277
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• 2005

In this paper, we introduce algorithms for constructing broadcasting and multicasting trees. These algorithms are general because they may be used for tree cost functions that are of arbitrary form. Thus, essentially the same algorithmic procedures are used for different tree cost functions. We evaluate the effectiveness of the general algorithms by applying them to different cost functions that are often used to model wired and wireless net­works. Besides providing a unifying framework for dealing with many present and future tree-construction applications, these algorithms typically outperform some existing algorithms that are specifically designed for energy-aware wireless networks. These general algorithms perform well at the expense of higher computational complexity. They are centralized algorithms, requiring the full network information for tree construction. Thus, we also present variations of these general algorithms to yield other algorithms that have lower complexity and distributed implementation.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1994.04a
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• pp.58-66
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• 1994

The philosophy of object-oriented has found its role in various applications such as programming languages, databases, distributed systems, etc. Discussed in this paper is an experience of the object-oriented programming technique obtained while developing a particular CAD/CAM system. It has been well-known that the object-oriented programming language has good features enabling the improved reusability and extensibility of an existing code. The features include data abstraction, encapsulation, inheritance, polymorphism, and so on. This paper presents how these features of the object-oriented programming language, C++ in particular, can be applied to the implementation of geometric algorithms as well as graphical user interfaces.

• Asia pacific journal of information systems
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• v.5 no.2
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• pp.51-78
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• 1995

This paper suggests a contingent perspective for analyzing information systems issues of the Korean firms. The contingent perspective includes such corporate characteristics as industry, organizational size, strategy, and value-added application function. This research surveyed 119 corporations in manufacturing, banking, distribution, and construction industries. Among those samples 104 data of corporate IS managers turned out to be statistically valid. As a result, those issues are ranked as the most urgent and important IS issues: strategic IS planning, system integration, application of database, process standardization, and network planning and implementation. Furthermore, factor analysis says that thirty issues to be surveyed are to be grouped into seven factors such as IS planning, user/education, database, applications of IT, system management, distributed computing technology, and network applications. It also found through Pearson correlation and ANOVA that organizational characteristics highly influences the IS issues the corporations face.

• 제어로봇시스템학회:학술대회논문집
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• 1992.10b
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• pp.22-28
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• 1992

The need for intelligent systems that can operate in an unstructured, dynamic environment has created a growing demand for the use of multiple, distributed sensors. While most research in multisensor fusion has revolved around applications in object recognition-including military applications for automatic target recognition-developments in microsensor technology are encouraging more research in affordable, highly-redundant sensor networks. Three trends that are described at length are the increasing use of microsensors, the techniques that are used in the handling of partial or uncertain data, and the application of neural network techniques for sensor fusion.

• IEIE Transactions on Smart Processing and Computing
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• v.5 no.4
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• pp.289-293
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• 2016

As more mobile devices are equipped with multi-core CPUs and are required to execute many compute-intensive multimedia applications, it is important to optimize the systems, considering the underlying parallel hardware architecture. In this paper, we implement and optimize ray-tracing application tailored to a given mobile computing platform with multiple heterogeneous processing elements. In this paper, a lightweight ray-tracing application is specified and implemented in Kahn process network (KPN) model-of-computation, which is known to be suitable for the description of real-time applications. We take an open-source C/C++ implementation of ray-tracing and adapt it to KPN description in the Distributed Application Layer framework. Then, several possible configurations are evaluated in the target mobile computing platform (Exynos 5422), where eight heterogeneous ARM cores are integrated. We derive the optimal degree of parallelism and a suitable distribution of the replicated tasks tailored to the target architecture.

• Proceedings of the KIPE Conference
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• 2010.07a
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• pp.357-358
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• 2010

An interleaved operation of isolated boost converter system has become a very attractive solution in order to convert from low input voltage (30 ~ 50V) of distributed power sources such as photovoltaic and fuel cells to high output voltage (380V/760V) required in grid-connected power conversion applications. In this paper, we have proposed zero voltage transition(ZVT) interleaved boost converter using a single resonant inductor.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2007.04a
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• pp.719-724
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• 2007

Many engineering problems often require the large amount of computing resources for iterative simulations of problems treating many parameters and input files. In order to overcome the situation, this paper proposes an e-Science based computational system. The system exploits the Grid computing technology to establish an integrated web service environment which supports distributed high throughput computational simulations and remote executions. The proposed system provides an easy-to-use parametric study service where a computational service includes real time monitoring. To verify usability of the proposed system, two kinds of applications were introduced. The first application is an Aerospace Integrated Research System (e-AIRS). The e-AIRS adapts the proposed computational system to solve CFD problems. The second one is design and optimization of protein 3-dimensional structures.

• Corrosion Science and Technology
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• v.15 no.2
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• pp.54-57
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• 2016

Magnesium alloys have been extensively studied in recent years for potential biodegradable implant applications. A great deal of work has been done on the evaluation of the corrosion behaviour of magnesium alloys under in vitro and in vivo conditions. However, magnesium alloys, in general, contain secondary phase particles distributed in the matrix and/or along the grain boundaries. Owing to their difference in chemistry in comparison with magnesium matrix, these particles may exhibit different corrosion behaviour. It is essential to understand the corrosion behaviour of secondary phase particles in magnesium alloys in physiological conditions for implant applications. This paper critically reviews the biodegradation behaviour of secondary phase particles in magnesium alloys.

• Journal of the Korea Society for Simulation
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• v.12 no.4
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• pp.51-59
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• 2003

Real-Time applications on Grid environment have several problems in terms of resource management addressed as follows; (1) dynamic resource allocation to provide QoS objectives, (2) heterogeneous resources that is different scale, or capacity in same unit, and (3) resource availability, and resource needs. This paper describes the techniques of resource manager (RM) handling above problems to support QoS of dynamic real-time applications on Grid. The contributions of this paper to solve problems are as follows: unification of dynamic resource requirements among heterogeneous hosts, control of resources in heterogeneous environments, and dynamic load balancing/sharing. Our heuristic allocation scheme works not only 257% better than random, 142% better than round robin, and 36.4% better than least load in QoS sensitivity, but also 38.6% better than random, 28.5% better than round robin, and 31.6% better than least load in QoS.

• Proceedings of the KIEE Conference
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• 2004.11b
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• pp.147-150
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• 2004

본 논문에서는 분산전원 계통을 모의하기 위한 시뮬레이터의 설계와 시험에 대한 내용을 제시하고자 한다. 제시하고자 하는 시뮬레이터는 RTDS(Real Time Digital Simulator)와 전력 증폭기(power amplifier)로 구성된다. RTDS 부분은 분산전원이 적용되는 계통의 모의와 분산전원의 전원부 모의를 위해 사용되며 전력 증폭기는 RTDS에 의해 모의된 전력 계통의 모선 전압 출력과 분산전원 전원부의 전압 출력을 증폭하기 위하여 사용된다. 시뮬레이터 구성을 위해 사용되는 RTDS의 구성과 제작된 전력 증폭기의 사양과 동작시험에 대한 결과를 제시하고자 한다. 개발된 시뮬레이터는 분산전원의 동적 및 정적 성능 평가를 위한 시험 시스템 개발에 적용될 수 있다.