• Journal of Electrical Engineering and Technology
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• 제12권5호
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• pp.1743-1753
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• 2017

Since there are multiple random variables in the probabilistic load flow (PLF) calculation of distribution system containing distributed generation (DG) and electric vehicle charging load (EVCL), a Monte Carlo method based on composite sampling method is put forward according to the existing simple random sampling Monte Carlo simulation method (SRS-MCSM) to perform probabilistic assessment analysis of voltage quality of distribution system containing DG and EVCL. This method considers not only the randomness of wind speed and light intensity as well as the uncertainty of basic load and EVCL, but also other stochastic disturbances, such as the failure rate of the transmission line. According to the different characteristics of random factors, different sampling methods are applied. Simulation results on IEEE9 bus system and IEEE34 bus system demonstrates the validity, accuracy, rapidity and practicability of the proposed method. In contrast to the SRS-MCSM, the proposed method is of higher computational efficiency and better simulation accuracy. The variation of nodal voltages for distribution system before and after connecting DG and EVCL is compared and analyzed, especially the voltage fluctuation of the grid-connected point of DG and EVCL.

• 한국항행학회논문지
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• 제20권5호
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• pp.408-416
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• 2016

본 연구에서는 선내 수집데이터를 활용하는 선박 및 육상 서비스를 위한 선박용 어플리케이션 시스템과 해상 데이터 통합관리 및 상호교환을 위한 선육 간 통합 시스템을 활용한 선박 에너지효율 모니터링 시스템을 설계하였다. 선박 에너지효율 모니터링 시스템은 윈도우 기반의 응용프로그램으로 file base EDI 통신을 이용하도록 구성하였다. 주요기능으로 연료소모량 최소화를 위한 항로 계획, 에너지 소모 및 배출가스 배출 모니터링, 선박 에너지 효율 분석 및 분석데이터 분석을 구현하고 실 운항선박에 적용하여 시스템의 정상 동작을 확인하였다.

• Smart Structures and Systems
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• 제17권5호
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• pp.753-771
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• 2016

This paper addresses the free and transient responses of a SDOF linear complex stiffness system by making use of the Hilbert transform and the convolution integral. Because the second-order differential equation of motion having the complex stiffness give rise to the conjugate complex eigen values, its time-domain analysis using the standard time integration scheme suffers from the numerical instability and divergence. In order to overcome this problem, the transient response of the linear complex stiffness system is obtained by the convolution integral of a green function which corresponds to the unit-impulse free vibration response of the complex system. The damped free vibration of the complex system is theoretically derived by making use of the state-space formulation and the Hilbert transform. The convolution integral is implemented by piecewise-linearly interpolating the external force and by superimposing the transient responses of discretized piecewise impulse forces. The numerical experiments are carried out to verify the proposed time-domain analysis method, and the correlation between the real and imaginary parts in the free and transient responses is also investigated.

• 한국광학회지
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• 제23권5호
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• pp.197-202
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• 2012

맴핑용 레이저 레이더 실험실 시제품의 성능시험과 분석 결과를 소개한다. 광섬유 레이저와 아발란치 광검출기 외 관련 구성모듈로 이루어진 레이저 레이더 시스템이 설계, 제작되었다. 레이저 레이더 시스템은 현재 실험실 환경에서의 성능 확인을 목적으로 하는 실험실 시제품으로서, 레이저 레이더 광원 특성, 거리 정확도, 소광율, 오경보율과 같은 시스템 성능변수가 실험적으로 측정되었다. 실험결과 분석을 통해 레이저 레이더 시제품이 양호한 성능수준을 제시하는 것으로 확인되었다.

• Journal of Welding and Joining
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• 제32권5호
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• pp.58-64
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• 2014

The shipbuilding industry is facing the various problems of less demand and oversupply owing to the global economic crisis and the increase in shipbuilding countries. Shipyards of the industry are making effort to strengthen their ability to handle the crisis via a smartwork technology for flexible working environment. In this study, we developed a smartwork system that manages the information in shipbuilding process with mobile devices such as smart phones and tablet PCs. To successfully apply the developed smartwork system to shipyards, we analyzed several best practices and management tasks of the shipbuilding processes. The developed system was designed by CBD approach that is a branch of service-oriented software engineering for reusability and flexibility on the system. As it is designed considering the flexible working environment, it supports to increase their productivity by reducing the time required to carry out tasks and by increasing the mobility required to manage work performance in field of shipyards.

• 한국의류산업학회지
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• 제13권5호
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• pp.734-742
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• 2011

This study has been undertaken as a basic research for automatic pattern design for baseball uniforms manufactured under custom-MTM system, propose building up of a system whereby various partial patterns are combined under an automatic design system and develop a multi-combination type pattern searching algorithm which allows development of a various designs. As a result of this, type classification based on pattern design elements includes side, open, collar, facing and panel type. Design have been divided into coarse classification ranging from level 1 to 7 according to pattern design elements, based on a design distribution chart. Out of 7 such levels, 3 major types determining design which are, more specifically, level 1 sleeve type, level 2 open type and level 3 collar type, have been taken and combined to determine a total of 12 types to be used for design classification codes. Respective name of style and patterns have been coded using alphabet and numerals. Totally, pattern searching algorithm of multi-combination type has been developed whereby combination of patterns belonging to a specific style can be retrieved automatically once that style name is designated on the automatic pattern design system.

• 한국군사과학기술학회지
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• 제17권5호
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• pp.654-662
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• 2014

In the development of the weapon systems, utilization of Modeling & Simulation is growing in every aspect of development process. For the higher utilization of M&S, reuse of the M&S resources is needed to reduce the cost of M&S. I propose the M&S architecture framework that can enhance the reusability of the M&S resources in developing surface-to-air weapon systems. This M&S architecture design framework enables interoperability between the system and sub-systems. In this paper, the advantage and the necessity of the M&S architecture design framework will be described by introducing the cases that the M&S architecture framework reused in the combat experiments, the system development tests, the system operational tests and the concept developments in real projects. These cases will show the high reusability and efficiency of the M&S architecture design framework.

• 한국자동차공학회논문집
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• 제20권5호
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• pp.130-137
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• 2012

Automotive engines need strategies to satisfy with the emission regulations in terms of PM and NOx. HC-LNT (Hydrocarbon-Lean NOx Trap) with secondary injection system is considered as more practical technology in order to cope with emission regulations. The HC-LNT system, which is using diesel fuel itself as a reducing agent, absorbs NOx in lean exhaust gas condition and releases NOx in rich exhaust gas conditions. In this system, inappropriate amounts of reducing agent will slip through the LNT without the profits of conversion and cause additional emission problems. Therefore, the suitable amount of reducing agent should be supplied into the catalytic converter. In this research, engine emission test was conducted to optimize injection quantity at the various engine test conditions. Different exhaust layouts and catalyst shapes have been studied and extension unit which makes better uniformity of exhaust gas was used for HC-LNT system. From this results, the effect of secondary injection conditions on NOx conversion characteristics of HC-LNT was clarified.

• 센서학회지
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• 제16권5호
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• pp.361-368
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• 2007

Small size real-time ECG signal analysis function by QRS-complex detection was put into sensor nodes. Wireless sensor nodes attached on the patient’s body transmit ECG data continuously in normal u-healthcare system. So there are heavy communication traffics between sensor nodes and gateways. New developed platform for real-time analysis of ECG signals on sensor node can be used as an advanced diagnosis and alarming system for healthcare. Sensor node does not need to transmit ECG data all the time in wireless sensor network and to server PC via gateway. When sensor node detects suspicion or abnormality in ECG, then the ECG data in the network was transmitted to the server PC for further powerful analysis. This system can reduce data packet overload and save some power in wireless sensor network. It can also increase the server performance.

• 한국산학기술학회논문지
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• 제10권11호
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• pp.3048-3053
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• 2009

소형엔진은 매우 열악한 환경에서 작동하기 때문에 엔진으로 흡입되는 공기를 정화하는 흡기시스템은 매우 중요한 설계인자이다. 크랭크 실로부터 유입되는 블로바이 가스의 오일입자를 포집하기 위하여 장착되는 그리드는 제작과 장착이 어렵고 오일입자의 포집효율이 열악한 문제점이 있다. 본 연구는 이러한 소형엔진에 적용되는 흡기시스템을 개선하기 위하여 신규 모델을 해석적인 방법으로 개발하였다. 신규로 제안된 모델은 그리드를 삭제하고 블로바이홀의 위치를 변경하였다. 신규 모델의 오일입자 포집효율은 기존 대비 약 5배 향상되었으며, 그리드 삭제로 인하여 소형엔진 흡기시스템 제작 원가의 약 10%를 절감하였다.