• 한국자동차공학회논문집
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• 제6권1호
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• pp.122-133
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• 1998

This paper presents the static analysis, the modal analysis and the forced vibration analysis on engine structures to find out the structure-borne noise sources by finite element method. The deformation of engine structures under the maximum combu- stion gas force was calculated through the static analysis, and the resonance possibilities were predicted by the modal analysis which ascertains mode shapes and the corresponding frequencies of engine global and its major noise sources in engine surfaces were investigated with the forced vibration analysis by means of finding the transfer mobilities on engine surfaces due to the piston impact and the velocity levels due to the combustion in consideration of oil film stiffness and damping coefficients. Finally, the direction of engine structure-borne noise reduction can be estabilished by the above-mentioned analysis procedure and the reduction effect of cost on proto-type engine build-up is expected.

• 수산해양기술연구
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• 제35권3호
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• pp.323-327
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• 1999

Most of the underwater noise emitted by small fishing boat are owing to vibration of main engine and generator etc.. This paper describe on the spectrum analysis of underwater noise by engine generating in small fishing boat in order to build up comfortable environment for fisheries man and to reduce ambient noise. The obtained results are summerized as follows:1. When the underwater noise of 10ton class fishing boat measure and the frequency spectrum in varied revolution of engine 750, 900, 1000rpm analyze, the frequency pattern is similar to each other, the faster revolution of engine increase, the higher frequency spectrum level becomes. 2. In comparison of spectrum level of underwater noise between 10ton class and 14ton class fishing boat, the former level is higher than the latter. 3. Frequency spectrum pattern of two 14ton class fishing boat is similar to each other but spectrum level is a little difference, it is suggested to different by fitting condition of engine.

• 한국군사과학기술학회지
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• 제6권3호
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• pp.103-110
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• 2003

The present work was conducted to achieve the better understanding of the performance analysis technique for the expander type air turbo ramjet engine. For this purpose, the performance analysis was carried out using a small engine(8.0kN thrust) with two types of fuels. From this analysis, at the same input condition, the thrust of methane-fueled engine was 25% lower than that of hydrogen. In addition, the case of methane shows the inapplicable engine performance cycle.(i.e., The compressor work exceeds the turbine output power) These results come mainly from the different heating value of each fuel and specific heat. This analysis also shows that, to build a same performance cycle as the hydrogen case, the methane-fueled engine requires increased air and fuel flow rates, increased turbine expansion ratio, and decreased compressor pressure ratio.

• 한국추진공학회지
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• 제14권6호
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• pp.79-88
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• 2010

본 논문에서는 초음속 항공기용 저바이패스 터보팬엔진 성능 모델링에 관해 기술하였다. 대상 엔진은 Pratt and Whitney F100-PW-229 터보팬 엔진을 적용하였다. 일반적으로 엔진성능에 관한 상세한 상용정보는 알려져 있지 않다. F100-PW-229 터보팬 엔진성능 모델을 구축하기 위한 기초자료로 공개된 자료와 문헌 정보를 이용하였으며 구성품의 일반적 특성과 가정치에 대해 서술하였다. 엔진덱 데이터와 Gasturb11을 이용하여 구축된 엔진성능 모델의 해석 결과 비교를 통하여 엔진성능 모델이 적합하게 구성되었음을 보여주었다.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2004년도 Proceedings of ISRS 2004
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• pp.272-275
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• 2004

Recently, the services using position information of moving objects is embossed. Theses services needs the moving objects databases to manage moving object data with efficiency. To build the moving object databases, we must develop the moving object engine to mange, store, and search the spatio temporal data of moving object. The moving object engine has to support query syntax to search data that suitable for user need like LBS, Telematics, ITS, vehicle management system. In this paper, we design and implement the moving object engine to support service with moving object data. The moving object engine is able to support system environment that users are able to get the moving object data easily even they don't know complex data structure.

• 반도체디스플레이기술학회지
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• 제15권3호
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• pp.40-45
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• 2016

In this paper, the fire engine pump is controlled and monitored by the AJAX (Asynchronous Javascript and Xml) in the web server. The embedded system with built-in system having a processor and a memory of high performance occurs many problems in transmitting the large amount of data in real time through the web server. The AJAX is different from HTML (Hyper Text Makeup Language) with java script technology and can make RIA (Rich Internet Application). It process the necessary data by using asynchronous and it take advantage of usefulness, accessibility, a fast response time. Using AJAX can build up web server with real time and monitoring that fire engine pump status, check processing pump memory in the event of fire, also remotely monitors can do. The web server system can control the fire engine pump as like the black box. The experimental results show the effectiveness and commercialize possibility.

• 한국비블리아학회지
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• 제8권1호
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• pp.197-227
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• 1997

The main purpose of this study is ① to settle and to analyze the classification of the Internet Search Engine comparitively, and ② to build the compatible model of Internet Search Engine classification in order to seek information on the Internet resources. specially in the branch of the Computers and Internet areas. For this study, four Internet Search Engine (Excite, 1-Detect, Simmany, Yahoo Korea!), Inspec Classification and two distionaries were used. The major findings and result of analysis are summarized as follows : 1. The basis of the classification is the scope of topics, the system logic, the clearness, the efficiency. 2. The scope of topics is analyzed comparitively by the number of items from each Search Engine. In the result, Excite is the most superior of the four 3. The system logic is analyzed comparitively by the casuality balance and consistency of the items from each Search Engine. In the result, Excite is the most superior of the four 4. The clearness is analyzed comparitively by the clearness and accuracy of items, the recognition of the searchers. In the result, Excite is the most superior of the four. 5 The efficiency is analyzed comparitively by the exactness of indexing and decreasing the effort of the searchers. In the result, Yahoo Korea！ is the most superior of the four. 6 The compatible model of Internet Search Engine classification is estavlished to uplift the scope of topics, the system logic, the clearness, and the efficiency. The model divides the area mainly based upon the topics and resources using‘bookmark’and‘shadow’concept.

• International Journal of Air-Conditioning and Refrigeration
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• 제14권3호
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• pp.85-93
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• 2006

The present study has been conducted to simulate dynamics of a gas engine-driven heat pump (GHP) for the design of control algorithm. The dynamic model of a GHP was based on conservation laws of mass and energy. For the control of refrigerant pressures, actuators such as an engine throttle valve, outdoor fans, coolant three-way valves and liquid injection valves were controlled by P or PI algorithm. The simulation results were found to be realistic enough to be applied for the control algorithm design. The model could be applied to build a virtual real-time GHP system so that it interfaces with a real controller for the purpose of developing control algorithm.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2011년도 제42회 하계학술대회
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• pp.1770-1771
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• 2011

In mission planning of UAV applications, especially for the missions requiring height transitions, it is required to generate reference flight trajectories considering the performances of the engine installed in the UAV. Even though the vertical line following guidance based height transition trajectory generation method has been developed to build reference height transition trajectories easily, it is not adequate for considering engine performances effectively since many engine characteristics and performances have conventionally been described in the V-H(speed-height) plane which is not the very space where the UAVs are actually flying. In this paper, we derive the trajectories in V-H plane for the vertical line following flights. And based on the results, a new algorithm to design the reference height transition trajectories for UAV applicaions. Simulation results demonstrate that the proposed algorithm is very effective and easily applicable.

• Journal of Mechanical Science and Technology
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• 제20권2호
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• pp.278-285
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• 2006

The present study has been conducted to simulate dynamics of a gas engine-driven heat pump (GHP) for design of control algorithm. The dynamics modeling of a GHP was based on conservation laws of mass and energy. For automatic control of refrigerant pressures, actuators such as engine speed, outdoor fans, coolant three-way valves and liquid injection valves were PI or P controlled. The simulation results were found to be realistic enough to apply for control algorithm design. The model can be applied to build a virtual real-time GHP system so that it interfaces with a real controller in purpose of prototyping control algorithm.