• Transactions on Electrical and Electronic Materials
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• 제17권2호
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• pp.57-68
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• 2016

In this study, we present the modern hybrid system based power generation for electric vehicle applications. We describe the hybrid structure of modified current source based DC - DC converters used to extract the maximum power from Photovoltaic (PV) and Fuel Cell system. Due to reduced dc-link capacitor requirement and higher reliability, the current source inverters (CSI) better compared to the voltage source based inverter. The novel control strategy includes Distributed Maximum Power Point Tracking (DMPPT) for photovoltaic (PV) and fuel cell power generation system. The proposed DC - DC converters have been analyzed in both buck and boost mode of operation under duty cycle 0.5>d, 0.5<d<1 and 0.5<d for capable electric vehicle applications. The proposed topology benefits include one common DC-AC inverter that interposes the generated power to supply the charge for the sharing of load in a system of hybrid supply with photovoltaic panels and fuel cell PEM. An improved control of Direct Torque and Flux Control (DTFC) based induction motor fed by current source converters for electric vehicle.In order to achieve better performance in terms of speed, power and miles per gallon for the expert, to accepting high regenerative braking current as well as persistent high dynamics driving performance is required. A simulation model for the hybrid power generation system based electric vehicle has been developed by using MATLAB/Simulink. The Direct Torque and Flux Control (DTFC) is planned using Xilinx ISE software tool in addition to a Modelsim 6.3 software tool that is used for simulation purposes. The FPGA based pulse generation is used to control the induction motor for electric vehicle applications. FPGA has been implemented, in order to verify the minimal error between the simulation results of MATLAB/Simulink and experimental results.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2008년도 춘계종합학술대회 A
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• pp.628-631
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• 2008

항공기가 비행을 위한 준비단계에서 목적지에 도착할 때까지 항공기를 안전하고 보다 경제적이고 효율적으로 운항하기 위해 항공기와 지상시설 사이, 지상시설과 지상시설 사이의 정보전달과 교환이 필요하다. 현재는 AFTN이라는 폐쇄망을 이용하여 통신이 이루어지고 있지만, 첨단 통신기술을 적용하여 차세대 항공통신망이 구축되어 운영될 예정이다. 이로 인하여 외부네트워크에 연결된 지상시설은 공격에 의한 보안 취약성을 가진다. 따라서 항공통신망에서의 안전한 운용환경 구축을 위한 취약성 분석 및 보안 요구사항 연구가 필요하다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 춘계학술대회 논문집
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• pp.910-917
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• 2011

CBTC(Communication Based Train Control) car-borne equipment, a part of the communication based train control system, mainly consists of automatic train protection(ATP) functions, automatic train operation(ATO) functions as well as the interface functions with other equipment including CBTC wayside equipment and train control management system etc. The CBTC car-borne software implementing ATP/ATO functions is a real-time embedded software requiring a high level of safety and reliability. To satisfy the requirements of the CBTC car-borne software, the model-based design techniques are applied with SCADE(Safety-Critical Application Development Environment) to the development of the CBTC car-borne software. In this paper, we illustrate the process modeling the car-borne ATP/ATO functions satisfying system requirement specification with system requirement management, modeling and document generation tools etc. supported by SCADE. In addition, the developed models corresponding to the ATP/ATO functions are applied to the train with CBTC car-borne equipment through its corresponding EN-50128 standards-compliant C code generated by the code generator. It is shown from the test result that the ATP/ATO models developed by SCADE work well while the trains are running in driverless operation mode.

• 조명전기설비학회논문지
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• 제12권3호
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• pp.83-88
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• 1998

본 논문은 태양전지 연료전지 복합 전력시스랩에 대한 환경평가를 다목적함수의해 선정 보조시스템의 하나언 이상점 기법올 통하여 다루고자 한다. 그에 대한 평가는 발전소 건설에 필요한 부지량과 건설에서 해체때까지의 이산화탄소 배출량의 관점에서 이루어지며 그 결과는 기존의 화석연료 발전시스템들과 비교되어진다. 연료전지 발전은 이미 변덕스러운 날씨하에서 극심한 태양전지의 출력량 변회를 보상하기 위한 적절한 발전기술엄이 증명 되었다. 가장 적은 부지량을 필요로 하는 연료전지 발전은 태양전지 발전시스템의 과도한 부지 펼요량올 경감시 킬 수 있으며 그 태양전지-연료전지 복합 전력시스템은 건셜에서 해체때까지의 이산화탄소 배출량 면에서도 가장 적은 영향올 미치는 것으로 나타난다.

• 시스템엔지니어링학술지
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• 제11권2호
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• pp.85-93
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• 2015

Warehouse Management System (WMS) is a key control for Material Handling System (MHS) and Inventory Control System (ICS). How to design and implement for WMS is crucial factor for achieving the key performance index for Manufacturing Industry. In particular, iron and steel making industry, where the volume and weight is large and hence FIFO (First Input First Out) is not working, how to design WMS is a key factor. In this paper, we systematically define the problem of WMS via developing StR (Stakeholders' Requirements) or ORD (Operational Requirement Documents), SyR (System Requirement), and SA (System Architecture) based on the emerging technologies. In particular, IoT (Internet of Things), CPS (Cyber Physical System) concepts and enabling technologies haves been incorporated in developing Smart WMS. The deliverables of the research can provide a conceptual framework for developing the next generation industrial WMS.

• 대한임베디드공학회논문지
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• 제14권6호
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• pp.329-338
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• 2019

Today's embedded software (SW) developments are mostly preceded by composing Software Requirement Specification (SRS). In particular, in the domain of weapon systems, it is essential to have a systematic method for the verification of the SW functionality. To be more specific, it is crucial to check if the SW functionality is implemented as described in SRS, so-called SW suitability verification. Unfortunately, existing static or dynamic SW testing methods are not sufficient to evaluate suitability with SRS since those testings only verify the robustness of the SW codes. In this paper, we propose an automatic embedded SW suitability verification framework which is based on a structured SRS. The major challenge in the automation of this verification framework is how to get rid of ambiguities in SRS. In order to overcome this challenge, we propose a structured SRS description framework and the supporting toolchain for that. We show how the proposed framework is applied to an actual SRS of a weapon system.

• 한국농공학회지
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• 제36권2호
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• pp.44-55
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• 1994

This paper describes the development of real-time irrigation reservoir operation models that adequately allocate available water resources for paddy rice irrigation. Water requirement deficiency index(WRDI) was proposed as a guide to evaluate the operational performance of release schemes by comparing accumulated differences between daily release requirements for irrigated areas and actual release amounts. Seven reservoir release rules were developed, which are constant release rate method (CRR), mean storage curve method(MSC), frequency analysis method of reservoir storage rate(FAS), storage requirement curve method(SRC), constant optimal storage rate method (COS), ten-day optimal storage rate method(TOS), and release optimization method(ROM). Long-term forecasting reservoir operation model(LFROM) was formulated to find an optimal release scheme which minimizes WRDIs with long-term weather generation. Rainfall sequences, rainfall amount, and evaporation amount throughout the growing season were to be forecasted and the results used as an input for the model. And short-term forecasting reservoir operation model(SFROM) was developed to find an optimal release scheme which minimizes WRDIs with short-term weather forecasts. The model uses rainfall sequences forecasted by the weather service, and uses rainfall and evaporation amounts generated according to rainfall sequences.

• 디지털산업정보학회논문지
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• 제6권2호
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• pp.233-245
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• 2010

This paper proposes security architecture, security audit framework, and audit check item. These are based on the security requirement that has been researched in the information system audit. The proposed information security architecture is built in a way that it could defend a cyber attack. According to its life cycle, it considers a security service and security control that is required by the information system. It is mapped in a way that it can control the security technology and security environment. As a result, an audit framework of the information system is presented based on the security requirement and security architecture. The standard checkpoints of security audit are of the highest level. It was applied to the system introduction for the next generation of D stock and D life insurance company. Also, it was applied to the human resources information system of K institution and was verified. Before applying to institutions, system developers and administrators were educated about their awareness about security so that they can follow guidelines of a developer security. As a result, the systemic security problems were decreased by more than eighty percent.

• 융합보안논문지
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• 제5권4호
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• pp.33-40
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• 2005

교육은 정보를 받아들이는 가장 큰 통로의 하나라 할 수 있다. 유비쿼터스 시대를 맞이하면서 새로운 교육기술과 환경이 요구되고 이에 따른 많은 기술이 등장하고있다. 현재의 e-learning 또한 많은 요구점들을 해결하기위해 많은 변화가 이루어질 필요가있다. 본 논문서는 언제 어디서나, 어떤 내용에 관계없이 학습할수있는 유비쿼터스환경의 e-learning 모델을 위하여 기존 e-learning 모델의 한계점을 분석하고, 유비쿼터스 네트워크망과 차세대 센서기술등을 적용하여 SCORM표준안을 기반으로한 LMS에 학습콘텐츠의 변환서비스와 협력 학습서비스기능을 추가한 유비쿼터스 환경에 대응하는 LMS모델을 제안하였다. 학습형태 변환서비스는 센서 기술에 의해서 학습자의 주변상황을 감지 하거나 신체상태를 파악하여 스마트 센서로 정보화하여 학습자에게 가장 적합한 형태로 콘텐츠를 서비스해준다. Orestia SOB등의 센싱기술의 접목은 보다 원활한 협력학습 서비스를 가능케 해줄것이다.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2016년도 춘계학술대회
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• pp.591-593
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• 2016

Device-to-device (D2D) communications underlaid cellular infrastructure is an competitive local area services technology to promote spectrum usage for next generation cellular networks. These potential can only be tap through efficient interference coordination. Previous works only concentrated on interference from D2D pairs whiles interference from CUs to D2D pairs were neglected. This work focus on solving uplink interference problem emanating from multiple CUs sharing its resource with multiple D2D pairs. The base station (BS) acting as a supervisor selfishly institute a pricing scheme to manage the interference it experience from D2D pairs based on its Quality of service (QoS) requirement. D2D pairs following the supervisor make power allocation decisions considering the price from the BS in a non-cooperative game fashion. In order for the D2D pairs to also meet their QoS requirement, they suggest a price to the BS called discount price which reflects the interference they receive from the CUs. Finally, we analyze the proposed approach.