• Journal of Advanced Marine Engineering and Technology
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• 제5권1호
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• pp.34-51
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• 1981

Lately, due to increasing engine output by high supercharging, heavy crankshaft and propeller mass, as well as long strokes attended with the reduced crankshaft axial stiffness, the critical crankshaft axial vibration has frequently appeared in maneuvering range of the engine. Some investigators have developed calculating methods of natural frequencies and resonant amplitudes for crankshaft axial vibrations. But their reliabilities are uncertain as the estimated crankshaft axial stiffness are incorrect. The calculating procedure of these natural frequencies is practically analogous to the classical calculation of torsional vibration frequencies, except for an important difference due to the relationship of the axial stiffness of a crank and the angle between the crank and other, especially the adjacent, cranks. In this paper, 6 calculation formulae of crankshaft axial stiffness already published and a theoretically- developed one by authors are checked by comparing their calculating results with those measured values of one model crankshafat and three full-scale actual crankshafts. Also, the calculating methods of the crankshaft axial free vibration are investigated and their computer programs are developed. Finally, those developed computer programs are applied to calculating one model crankshaft and two full-scale actual crankshafts of ship's propulsion engines and their calculated results are compared with those measured values.

• 오토저널
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• 제7권3호
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• pp.74-82
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• 1985

Using single-zone heat release model and quasi-steady model, computer program for calculating the compression ignition engine cycle was composed. The properties in the cylinder were calculated in terms of crank angle and the effects of various operating conditions on rate of heat release and on engine performance were studied. The predicted values for the engine under consideration have shown good agreement with published data.

• 센서학회지
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• 제20권4호
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• pp.243-248
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• 2011

The purpose of this study is to develop a sensing system to measure the capacitance of a pre-developed engine oil deterioration detection sensor integrated with an oil filter. To measure the capacitance of engine oil in the sensor, it is used the way measuring the electric charging time in a capacitor by impressing DC volt. This method has merits on cost and signal stability. The measured capacitance is compensated by comparison with the one measured by an impedance analyzer. Also, using the dielectric constant gained by an impedance analyzer, the calculating equation of the dielectric constant of engine oil related with the currently developed sensor is decided. Finally, the degradation degree of engine oil is estimated according to the change rate of dielectric constant between green oil and used oil. The newly developed personal controller is to control a series of the processes.

• Tribology and Lubricants
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• 제27권3호
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• pp.125-133
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• 2011

The purpose of this study is to develop an engine oil quality monitoring system to warn the abnormal condition of engine oil. To do this, first of all, it is needed a personal controller development to measure the capacitance of a pre-developed engine oil deterioration detection sensor integrated with an oil filter. To measure the capacitance of engine oil in the sensor, it is used the way measuring the electric charging time in a capacitor by impressing DC volt. This method has merits on cost and signal stability. The measured capacitance is compensated by comparing with the one measured by an impedance analyzer. Also, using the dielectric constant gained by an impedance analyzer, the calculating equation of the dielectric constant of engine oil related with the currently developed sensor is decided. Then, the deterioration degree of engine oil is estimated according to the change rate of dielectric constant between green oil and used oil. Finally, using this dielectric constant information together with engine oil temperature and pressure, the currently developed engine oil quality monitoring system is to tell the abnormal state of engine oil.

• 문화기술의 융합
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• 제5권2호
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• pp.111-116
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• 2019

본고는 인간과 기계의 존재론적 위상의 변화를 일으킨 '생각하는 기계' 등장의 역사적 형성 배경을 검토한다. 특히 영국인 수학자 찰스 바비지의 계산기관을 '생각하는 기계'의 시원으로 설정하고, '생각'이 인간의 능력이 아니라 기계의 기능으로 전환되는 과정에 초점을 둔다. 이를 위해 제2장에서는 인간의 육체와 정신의 실체를 분리하고 기계 지성의 가능성을 거부하는 데카르트의 이원론을 검토한다. 제3장에서는 데카르트의 인간과 기계의 본원적인 대립을 기각함으로써 생각과 연관되는 인간의 '기능'을 강조하는 찰스 바비지의 철학적 주장을 검토한다. 이런 과정을 통해 본고는 바비지의 '생각하는 기계'의 개념화가 필연적으로 인간 정체성에 연루된 개념들의 재조직화와 재구성을 수반할 수밖에 없음을 확인하고, 동시대 인공지능 테크놀로지의 변화에 대한 새로운 관점을 사유하게 하는 재료를 제안한다.

• Journal of Advanced Marine Engineering and Technology
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• 제28권7호
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• pp.1101-1110
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• 2004

An one-zone heat release analysis was applied to a 4 cylinder indirect injection diesel engine. The objective of the study is to calculate heat release accurately considering the effect of specific heat ratio. heat transfer and crevice model and to find out combustion characteristics of an indirect diesel engine considering the effect of the pressures in main and swirl chambers. Especially specific heat ratio indicating combustion characteristics is adapted. instead of that indicating matter properties, which has been used in former studies Moreover by adaption of blowby model, cylinder gas mass became accurately calculated. Therefore, with ideal gas equation, calculating cylinder gas temperature, it was found to affect heat transfer loss and heat release. Determining heat transfer constants $C_1$. $C_2$ as 0.6 respectively. the integrated gross heat release values were predicted well for the measured value at various engine speed, full load operating conditions. The curve of heat release rate was similar to SI engine rather than DI engine. That is originated from that swirl chamber reduce an instant combustion which occurs in DI engine due to ignition delay on early stage of combustion.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2009년도 정보 및 제어 심포지움 논문집
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• pp.156-158
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• 2009

A graphic simulator is efficient to see what will happen to the target robot. But it is not exactly same as the real world. Because there are so many physical laws to be concerned. In this paper, we propose a simulator with physics engine to create motions for quadruped robot. It is not only to show more real simulations but also to be more efficient for teaching motions to quadruped robot. To solve the quadruped robot's dynamics or inverse kinematics, It takes much times and hard effort. Using physics engine make it easy to setup motions without calculating inverse kinematics or dynamics.

• 한국언어정보학회:학술대회논문집
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• 한국언어정보학회 2007년도 정기학술대회
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• pp.126-135
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• 2007

We propose and test several computational methods to automatically determine possible saliency cut-off points in Sketch Engine (Kilgarriff and Tugwell, 2001). Sketch Engine currently displays collocations in descending importance, as well as according to grammatical relations. However, Sketch Engine does not provide suggestions for a cut-off point such that any items above this cut-off point may be considered significantly salient. This proposal suggests improvement to the present Sketch Engine interface by calculating three different cut-off point methods, so that the presentation of results can be made more meaningful to users. In addition, our findings also contribute to linguistic analyses based on empirical data.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2017년도 제48회 춘계학술대회논문집
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• pp.572-582
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• 2017

공기 흡입 엔진을 개발하기 위해서는 지상 시험을 통한 추력 측정이 반드시 필요한데, 공기 흡입 엔진은 추력 측정 장치에서 측정된 값 이외에도 엔진 흡입구로 들어오는 공기 유동에 의한 힘을 고려하여 총추력을 계산해야 한다. 또한 다분력 추력 측정 장치를 활용하여 요와 피치 방향의 측추력도 정확하게 측정하고 분석할 수 있어야 한다. 래버린스 씰 격리, 1축 총추력 계산, 다분력 추력 측정 장치 개발, 측추력 분석 등의 일련 과정을 통해 공기 흡입 엔진의 총추력을 정밀하게 추정하여 엔진 성능을 보다 정확하게 평가할 수 있게 하였다.

• 동력기계공학회지
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• 제3권3호
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• pp.36-43
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• 1999

Many of thermodynamic-based diesel combustion simulations incorporated a model of fuel spray which attempts to describe how the spray develops according to time. Because the spray geometry is an essential aspect of the fuel-air mixing process, it is necessary to be calculated quantitatively for the purpose of heat release and emission analysis. In this paper, we proposed the calculating method of non-evaporation spray behaviors by injection rate shapes under actual operating conditions of diesel engine. We confirmed the utility of this calculating model as the calculated results were compared with the measured results. This calculating program can be applied usefully to study on the diesel spray behavior.