• Transactions of the Korean Society of Automotive Engineers
• /
• v.15 no.4
• /
• pp.186-192
• /
• 2007

We research into the exhaust system volume what proving the optimum exhaust performance and combustion characteristics. Many automobile manufactures have developed complex exhaust system for environment regulation and noise reduction. This complex exhaust system provides acoustics silencing and low frequency noise for customers demand. Recently, automobile exhaust system have made the Dual muffler concerning to the noise and vibration reduction. Also it bring the engine performance down by decreasing the back pressure and temperature in the exhaust system. The experiments are carried out different volume of exhaust system. In order to establish the optimized conditions design factors which are taking exhaust system volume, it show how the exhaust performance influence on the engine performance in idling.

• Proceedings of the KIEE Conference
• /
• 1995.07b
• /
• pp.637-639
• /
• 1995

Since power systems tend to be more large and complex, expert system substituted for the decision-making achieved by the power system operation expert is required. So far, expert system has been used for fault diagonosis and voltage-reactive power control and so on. In the expert system developed using 'C' language, the faulted element is estimated using the AND operation of lists which are acquired from the information on operated relays. It is also considered to identify the misoperation of protective devices using CF(Certainty Factor), and operation failure of those using the data base of parameter group list. The developed expert system is applied to a 6-bus sample system and through the case studies. It is shown that the expert system is very useful.

• International Journal of Fuzzy Logic and Intelligent Systems
• /
• v.8 no.2
• /
• pp.140-145
• /
• 2008

In this paper, we constructed the advanced cargo monitoring system for liquid cargo tankers which embedded the Decision Support System (DSS) based on the International Ship Management Code (ISM Code). To make this system, we first organized a base of expert's knowledge concerning liquid tanker operations that largely affect ocean accidents. We can find out the knowledge via inference method which simply imitates the fuzzy inference method. Based on this expert's knowledge, we constructed the DSS that provides a code of conduct for operating cargo tanks safely. The proposed monitoring system could eliminate human error when confronting dangerous situations, so the system will help sailors to operate cargo tanks safely.

• Journal of Electrical Engineering and Technology
• /
• v.9 no.2
• /
• pp.390-398
• /
• 2014

The systematic optimal tuning of power system stabilizers (PSSs) using the dynamic embedded optimization (DEO) technique is described in this paper. A hybrid system model which has the differential-algebraic-impulsive-switched (DAIS) structure is used as a tool for the DEO of PSSs. Two numerical optimization methods, which are the steepest descent and Broyden-Fletcher-Goldfarb-Shanno (BFGS) algorithms, are investigated to implement the DEO using the hybrid system model. As well as the gain and time constant of phase lead compensator, the output limits of PSSs with non-smooth nonlinearities are considered as the parameters to be optimized by the DEO. The simulation results show the effectiveness and robustness of the PSSs tuned by the proposed DEO technique on the IEEE 39 bus New England system to mitigate system damping.

• Proceedings of the SAREK Conference
• /
• 2006.06a
• /
• pp.381-386
• /
• 2006

This study is to research application cases of domestic ventilation system for developing ventilation system which is energy-saving and improve Indoor Air Quality and to research application possibility of foreign hybrid ventilation system. This is a basic research data of developing ventilation system for energy saying and improving indoor quality which that research the function and a feature of the ventilation system which is applied in five domestic skyscrapers over 30 floors, and research application instances and features of foreign hybrid ventilation system.

• International Journal of Air-Conditioning and Refrigeration
• /
• v.9 no.4
• /
• pp.47-54
• /
• 2001

The simulation program which can predict major performances of the multi-type heat pump system was developed. In order to verify the simulation program, several experimental tests were performed under various recommended conditions. The experimental results show in good agreement with simulation results. The verified simulation program was used to analyze the system performance. The capacities and the COP＇s under the various indoor and outdoor conditions were predicted. Therefore, it may be concluded that the system simulation program developed in this study may be effectively used for the system design and the performance prediction of the multi-type heat pump system.

• Journal of Integrative Natural Science
• /
• v.12 no.1
• /
• pp.14-19
• /
• 2019

In this paper, we propose a system for controlling the brightness of street lights by predicting pedestrian paths, identifying the position of pedestrians with motion sensing sensors and obtaining motion vectors based on past walking directions, then predicting pedestrian paths through the route prediction smart street lighting system. In addition, by using motion vector data, the pre-treatment process using linear interpolation method and the fuzzy system and neural network system were designed in parallel structure to increase efficiency and the rough set was used to correct errors. It is expected that the system proposed in this paper will be effective in securing the safety of pedestrians and reducing light pollution and energy by predicting the path of pedestrians in the detection of movement of pedestrians and in conjunction with smart street lightings.

• International conference on construction engineering and project management
• /
• 2009.05a
• /
• pp.1404-1409
• /
• 2009

These days, the extension and complication of construction project has attached greater significance to IT system for effective project management. Construction companies inside the country have established IT system, but the fact is that they are not up to the expectations of investment provision, and the absense of objective and strategy about project management information system makes its efficiency doubtful. The research, from the point view of construction company, makes an estimate of indefinite future, and presents the process of making out IT system roadmap as a long-term strategy in building IT system.

• Journal of Aerospace System Engineering
• /
• v.17 no.5
• /
• pp.11-18
• /
• 2023

The architecture of the Fuel Thermal Management System (FTMS) in a commercial aircraft engine was built to model and simulate the fuel system. The study shows the thermal interactions between the fuel and engine lubrication oil through the mission profile of a high bypass ratio, two-spool turbofan engine. Fuel temperature was monitored as it flowed through each sub-component of the fuel system during the mission. The heat load in the fuel system strongly depended on the fuel flow rate, and was significantly increased for the periods of cruise and descent with decrease of fuel flow rate, rather than for the periods of take-off. Due to the thermal interaction in the pump housing, the fuel temperature at the outlet of the low-pressure pump was increased (4.0, 9.2, and 30.0) % over the case without thermal interaction for take-off, cruise, and descent, respectively.

• Journal of Korean Clinical Nursing Research
• /
• v.14 no.3
• /
• pp.117-128
• /
• 2008

Purpose: This study was conducted to examine the differences of knowledge, perception, and performance between the points of time before and after ICU nurses had the backrest elevation education. Method: The study subjects were 58 nurses at a medical and surgical ICU of one general Y hospital located in Seoul. They received the education, including backrest elevation guideline and related education materials. Data were collected from May 11 throughout August 12, 2007 with a structured questionnaire. Results: 1) There were significant differences in the mean scores of knowledge(2.21 at pre-education, 5.24 at post-education), perception(36.96 at pre-education, 53.36 at post-education), and performance(32.08 at pre-education, 43.51 at post-education), 2) There was a significant correlation between nurse's perception and performance (p=.000). 3) The nurse's perception regarding the importance of the back rest elevation education was significantly effective on their performance (p=.000). Conclusion: The backrest elevation education would contribute to improve ICU nurse's knowledge, perception and performance. The more the nurses would consider the importance of this education, the better they would perform the nursing intervention of backrest elevation.