• Journal of Communications and Networks
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• v.11 no.2
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• pp.187-195
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• 2009

The application of mathematical analysis to the study of wireless ad hoc networks has met with limited success due to the complexity of mobility, traffic models and the dynamic topology. A scenario based universal mobile telecommunications system (UMTS) time division duplex (TDD) opportunistic cellular system with an ad hoc behaviour that operates over UMTS frequency division duplex (FDD) licensed cellular network is considered. In this paper, we present a new routing metric which overall improves system performance in terms of interference and routing which operate in an ad hoc network in an opportunistic manner. Therefore we develop a simulation tool that addresses the goal of analysis and assessment of UMTS TDD opportunistic radio system with ad hoc behavior in coexistence with a UMTS FDD primary cellular networks.

• Journal of the Korean Society of Systems Engineering
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• v.8 no.1
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• pp.77-82
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• 2012

In Weapons acquisition process, if the requirements are not clear, it leads to confusion and conflict in business. In the development of next-generation weapons, to define and derive requirements has to start from decision of operational concept. It is difficult task and has many uncertainties. This paper has goal about development of knowledge acquisition process that derive military operational scenario-based requirements acquisition process and framework that classify and save the derived requirements for next project. That framework can generate new class and category, also suggest that verification of requirements. It help to derive and manage the requirements, and make it easy to grasp the requirements. Accordingly, it can help make military requirement plan and weapon acquisition process.

• ETRI Journal
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• v.30 no.1
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• pp.113-128
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• 2008

Turbo codes are extensively used in current communications standards and have a promising outlook for future generations. The advantages of software defined radio, especially dynamic reconfiguration, make it very attractive in this multi-standard scenario. However, the complex and power consuming implementation of the maximum a posteriori (MAP) algorithm, employed by turbo decoders, sets hurdles to this goal. This work introduces an ASIP architecture for the MAP algorithm, based on a dual-clustered VLIW processor. It displays the good performance of application specific designs along with the versatility of processors, which makes it compliant with leading edge standards. The machine deals with multi-operand instructions in an innovative way, the fetching and assertion of data is serialized and the addressing is automatized and transparent for the programmer. The performance-area trade-off of the proposed architecture achieves a throughput of 8 cycles per symbol with very low power dissipation.

• 한국정보교육학회:학술대회논문집
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• 2007.08a
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• pp.240-245
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• 2007

하루가 다르게 우리 사회의 모습은 정보화, 디지털화 되어 가고 있다. 이러한 시대적 흐름에 맞추어 정보통신기술교육에 대한 관심과 중요성이 커지고 있으며, 단순히 기능을 가르치는 교육에서 문제해결력을 기르는 방향으로 변하고 있다. 이러한 정보통신기술교육의 변화를 반영하기 위해서는 보다 다양하고 체계적인 교수 학습 모형에 대한 연구가 필요하다. 이에 본 연구에서는 구성주의 교육방법론의 하나로 학습자에게 행함에 의한 학습(learning-by-doing)이 이루어지는 모의 상황을 통해 학습 목표를 달성할 수 있도록 하는 목표기반 시나리오학습(Goal-Based Scenario : GBS) 이론을 초등학교 정보통신기술교육에서 활용할 수 있는 교수 학습 모형을 제안하고자 한다. 즉, 교육현장에서 초등학교 학생들에게 적용할 GBS 교수 학습 모형에 대한 연구로 체계적인 정보통신기술교육의 정착에 도움이 되고자 하는데 의의를 둔다.

• Journal of Advanced Marine Engineering and Technology
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• v.27 no.1
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• pp.91-99
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• 2003

This paper describes the development of a pc-based machinery space simulator for training and research, relevant to STCW-95. The detailed mathematical modelling process for the actual machinery is discussed and a method to perform effective education and training for the simulator is suggested. The method includes scenario, procedure, exercise and evaluation. The procedure guides the trainee through a sequence of steps designed to meet a specific goal, showing the trainee what must be done and explaining why The exercise enhances understanding for efficient engine management and enable user to perform research for the machinery. The evaluation shows exercise results and feeds back to instructor how to guide the under-performed trainee.

• Proceedings of the Korean Information Science Society Conference
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• 2007.06b
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• pp.123-128
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• 2007

지능형 서비스 로봇이란 기존의 로봇과는 다르게 사용자에게 다양한 서비스를 제공하는 로봇이다. 이 로봇은 주변의 상황을 인지하고 그 환경에 적절한 서비스를 사용자에게 제공해야 하므로 여러 가지 복잡한 하드웨어와 기술을 필요로 하고 그에 맞는 요구사항을 추출하기가 더 어려운 상황이다. 본 논문에서는 이러한 상황에 맞춰 요구사항을 추출하고 분석할 때 시나리오 기반이나 목표 기반 등 한가지 기법을 사용한 분석 방법보다는 두 방법을 통합한 목표와 시나리오 기반의 분석방법을 로봇 시스템에 적용해 보고자 하였다. 이를 위해 노인의 생활을 보조하고 지원하는 실버메이트에 직접 적용해 보고 그에 따른 장점과 개선점들을 살펴본다.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.31 no.4
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• pp.100-105
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• 2008

Cost reduction, time to market, and quality improvement of software product are critical issues to the software companies which try to survive in recent competitive market environments. Software Product Line Engineering (SPLE) is one of the approaches to address these issues. The goal of software product line is to maximize the software reuse and achieve the best productivity with the minimum cost. In software product line, software components are classified into the common and variable modules for composition work. In this paper, we proposed a dynamic composition process based on aspect-oriented programming methodology in which software requirements are classified into the core-concerns and cross-cutting concerns, and then assembled into the final software product. It enables developers to concentrate on the core logics of given problem, not the side-issues of software product such as transactions and logging. We also proposed useful composition patterns based on aspect oriented programming paradigm. Finally, we implemented a prototype of the proposed process using Java and Aspect to show the proposed approach's feasibility. The scenario of the prototype is based on the embedded analysis software of telecommunication devices.

• New & Renewable Energy
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• v.18 no.2
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• pp.50-59
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• 2022

The Korean government announced the "1st Basic Plan for the Transition to Hydrogen Economy" in 2021 and declared the establishment of a hydrogen industry ecosystem by 2040. To build a low-carbon power system, resources that can efficiently accommodate renewable energy are required, and green hydrogen is considered a potential solution. This study analyzed the economic feasibility of green hydrogen-based sector coupling to reduce curtailment of renewable generation in the Jeju power system by 2025 under the scenario of with or without HVDC#3. The result showed that HVDC#3 significantly reduced the frequency of curtailment from 16.1% to 3.0%. In addition, green hydrogen-based sector coupling was an economically feasible option as result showed an IRR of 4.86% when HVDC#3 was connected and 11.45% when it was not under the condition of achieving 50% curtailment reduction. This study shows that the higher the level of renewable energy deployment, the more delayed the HVDC connection between Jeju and the main land, and the lower the SMP, the more economically feasible the green hydrogen-based sector coupling is. Furthermore, this study suggests that the policy goal of completely reducing curtailment is not economically efficient.

• Journal of Communications and Networks
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• v.18 no.1
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• pp.50-64
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• 2016

Nowadays, smart meter (SM) technology is widely effectively used. In addition, power allocation (PA) and channel selection (CS) are considered problems with many proposed approaches. In this paper, we will suggest a specific scenario for an SM configuration system and show how to solve the optimization problem for transmission between SMs and the data concentrator unit (DCU), the center that collects the data from several SMs, via simulation. An efficient CS with PA scheme is proposed in the TV white space system, which uses the TV band spectrum. On the basic of the optimal configuration requirements, SMs can have a transmission schedule and channel selection to obtain the optimal efficiency of using spectrum resources when transmitting data to the DCU. The optimal goals discussed in this paper are the maximum capacity or maximum channel efficiency and the maximum allowable power of the SMs used to satisfy the quality of service without harm to another wireless system. In addition, minimization of the interference to the digital television system and other SMs is also important and needs to be considered when the solving coexistence scenario. Further, we propose a process that performs an interference analysis scheme by using the spectrum engineering advanced Monte Carlo analysis tool (SEAMCAT), which is an integrated software tool based on a Monte-Carlo simulation method. Briefly, the process is as follows: The optimization process implemented by genetic evolution optimization engines, i.e., a genetic algorithm, will calculate the best configuration for the SM system on the basis of the interference limitation for each SM by SEAMCAT in a specific configuration, which reaches the solution with the best defined optimal goal satisfaction.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.50 no.7
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• pp.303-308
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• 2001

This paper presents algorithm to plan construction and expanding of substation considering contingency accidents by proposing utilization factor according to configuration of substation bank system. In this paper, firstly, proper sphere of supply area by each district which could be standardized with respect to its supply capacity is established under assumption of long term load forecasting. Secondly, goal of utilization ratio based on configuration of substation bank was set to keep reliability by remaining sound bank when it happen to one bank accidents. Finally, it is set up for optimal construction and expanding of substation considering economy and reliability simultaneously about substation to exceed these ratio. To verify proposed algorithm, at first, after adopting a part of Kangnam area in Seoul as area for testing, it is divided into several regions for this area according to power branches of power utility. Secondly, by deriving correlation factor between load demand and economic indicators in these region respectively, the regional load forecasting was performed with economic growth and city plan scenario. Finally, based on the predicted load demand by region and land use data which is identified from air-photographic, the load demand by district was predicted. Also, planning for substation considering contingency is formulated to expand taking into account computing utilization factor which is based on configuration of substation bank respectively.