• 한국산업융합학회 논문집
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• 제14권3호
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• pp.113-119
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• 2011

This study analyzed facts affecting the performance of refrigeration systems after throttling actions, by changing the amount of refrigerant according to adjusting the opening of manual expansion valve to 80%, or 20% with vapor compressional refrigeration training equipment. At opening of 20%, the inlet and outlet temperature of compressor, subcooling and superheat, condenser heat, refrigeration effect, flash gas heat, coefficient of performance were higher, while at 80%, condensing pressure, evaporating pressure, compression work were higher, Thus, we could see changes in the amount of refrigerant affect the performance of the refrigeration system.

• 한국산업융합학회 논문집
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• 제15권1호
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• pp.29-36
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• 2012

Reinforced concrete shear walls and X-type steel braces were applied in seismic retrofit techniques for seismic performance evaluation of school buildings constructed in accordance with standard design announced by the ordinance of the ministry of construction in 1980s. Seismic performance evaluation was based on FEMA 356 using response spectrum as elastic analysis and conducted to pushover analysis with nonlinear static analysis. The maximum displacement ratio between floors in 4th and 3rd floors of the existing school buildings was less than 1.0%, which was functioning level in FEMA 356. However, because plastic hinge occurs somewhat in structural members according to the results of pushover analysis, partial reinforcement will be required. X-direction of the maximum lateral displacement of reinforced concrete shear walls than X-type steel braces was 45% and 32% in 4th and 3rd floors of school buildings, and Y-direction was 18% and 17%, respectively.

• 융복합기술연구소 논문집
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• 제3권1호
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• pp.19-23
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• 2013

This study is concerned with air-conditioning system in use of thermoelectric device. It is introduced that the well designed structures for better cooling & heating performance with high efficiency. And also it is performed that the system performance test of four types trial products for the use of hybrid commercial vehicle. System performance is affected by many component parts, especially heat sink design & power control method. It is applied that dual extrusive fin tube with buffer zone for the effective radiating of circulating liquid in tube. And also it is applied that power supply method with constant-current system. It is attained that system cooling capacity is 1.2kW, COP is 0.95.

• 한국산업융합학회 논문집
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• 제14권2호
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• pp.79-85
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• 2011

This study has been experimented about refrigeration capacity difference. It has been used 3 method, Manual expansion valve, thermostatic expansion valve and capillary expansion valve, and tested under the same condition by using the performance testing of parallel expansion. In temperature change of the temperature room, thermostatic expansion valve method displayed the most lower temperature, $-18^{\circ}C$. In addition, the temperature, just before the expansion, also displayed the best result which was $4^{\circ}C$ lower than other expansion valve. In these results, it can be used for performance testing of parallel expansion refrigeration system.

• 융합보안논문지
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• 제5권3호
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• pp.87-92
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• 2005

암호화 기술을 이용하여 고비도의 정보보호를 달성하고자 하는 VPN 시스템에서는 암호 가속 성능이 관건이다. 그러나 암호 연산은 많은 계산량을 필요로 하고 소프트웨어로 구현되었을 경우에는 그 성능에 한계가 있기 때문에, 전용의 암호 가속 하드웨어를 이용하여 구현하는 것이 필수적으로 요구된다. 본 논문에서는 많이 사용되어지는 블록 암호 알고리즘인 DES, 3DES, AES, SEED가 실장된 암호 가속 칩을 이용하여 PCI 카드를 설계 제작한 사례를 소개하고 있다. 제작한 암호가속카드는 상용 VPN 시스템에 실장된 후 그 성능이 평가되었다.

• 한국산업융합학회 논문집
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• 제19권3호
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• pp.101-108
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• 2016

I propose a hybrid fuzzy controller with a look-up table to improve the performance of the FARMA(Fuzzy Auto-regressive Moving Average) fuzzy controller. The hybrid structure of the proposed method is composed of a fuzzy controller with a look-up table of the PD type and the FARMA fuzzy controller. The proposed method improves poor performance due to the lack of I/O data to calculate predictive output and shows robust performance over the FARMA fuzzy controller when a incorrect Dmax value is selected by trial and error. I executed some computer simulations on the regulation problem of an inverted pendulum system and compared the results with those of the FARMA fuzzy controller.

• 중소기업융합학회논문지
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• 제4권4호
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• pp.7-12
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• 2014

This study empirically investigated cultural differences in the amount of information provided by managerial accounting information systems as well as the differences in organizational performance according to variations in the amount of information. Through cluster analysis, I classified sample firms into five organizational cultural types: Semi-innovative, innovative, bureaucratic, semi-bureaucratic and supportive. The results showed that in the semi-innovative firms, a greater amount of the traditional and advanced types of information is produced, while in bureaucratic firms, traditional information is much more provided than in the innovative, semi-bureaucratic and supportive firms. These results confirmed cultural differences in the amount of information produced. According to the results of this study, it was found that in organizational performance, the rankings of semi-innovative firms, which have the highest scores in the amount of information, are also the highest, and the performance scores in innovative firms are generally next to those of semi-innovative firms. Hence it is concluded that there are cultural differences in the amount of information provided and theses differences affect organizational performance

• 융합신호처리학회 학술대회논문집
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• 한국신호처리시스템학회 2003년도 하계학술대회 논문집
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• pp.169-172
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• 2003

PID control has been well used for several decade. For PID algorithm, some tuning methods are used and with these parameters, control system is designed. But in some cases various kinds of performance are needed, so variable type of performance index must be utilized so that the designed control system meets the conditions. This paper presents some linear combinational type of performance index and with numerical methods, the PID parameters are obtained. Moreover I-PD type controller is used so that this two degree of freedom controller may give more desirable output characteristics. Simulations are done with MATLAB m file and mdl files.

• 한국산업융합학회 논문집
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• 제23권4_2호
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• pp.645-651
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• 2020

In this study, It is necessary that we should study on more effective use about reciprocating engines because there are huge increase of air pollution. Diesel Engine is operated by injecting fuel directly to combustion chamber with high pressure. Diesel Engine has greater thermal efficiency and durability than Gasoline Engine. Also, Diesel Engine emitted low harmful exhaust witch caused by Gasoline Engine. There are many ways to improve of performance and decrease of harmful exhaust by controlling injection timing, changing amount of fuel and engine speed and so on. Especially, development and application of common rail direct injection Engine cause the increase of thermal efficiency by controlling a various of operating conditions. In this study we analyze characteristics of performance by changing a various of operating conditions.

• 한국산업융합학회 논문집
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• 제23권6_1호
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• pp.889-896
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• 2020

We describe a new approach to the analyze the control performance of robotic manipulator based on the monitoring system. The structure of monitoring simulator is consist of seven modes such as control state mode, coordinate mode, input/output mode, program mode, parameters mode, and track mode. The applied control algorithme consists of an time varying feed-forward and feedback controller. The proposed scheme is simple in structure, fast in computation, and suitable for real-time implimemtation. Moreover, this scheme does not require any accurate dynamic modeling and values of parameters. Performance of the proposed monitoring system is illustrated by simulation and experiment for robot manipulator with six degrees of freedom.