• Journal of Advanced Marine Engineering and Technology
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• v.5 no.1
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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.

• Journal of the korean Society of Automotive Engineers
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• v.7 no.3
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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.

• Journal of Sensor Science and Technology
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• v.20 no.4
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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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• v.27 no.3
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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.

• The Journal of the Convergence on Culture Technology
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• v.5 no.2
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• pp.111-116
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• 2019

This paper considers the historical background of the emergence of 'thinking-machine,' that has changed the ontological statue of human and machine. In particular, British mathematician Charles Babbage's Calculating Engines is examined as a material iteration of thinking-machine, focusing on the discursive process by which thought is not the faculty of human, but the function of machine. In Chapter II, I review the dualism of René Descartes who denied the possibility of machine intelligence by separating the substance of body and mind. In Chapter III, Babbage's philosophical assertions which emphasized the function of human associated with thought by rejecting the fundamental opposition between human and machine. Therefore, this paper verifies that the conception of 'thinking-machine' essentially causes the reorganization and reformulation of concepts involved with human identity, and provides the sophisticated sources to prepare new perspective on the artificial technology nowadays.

• Journal of Advanced Marine Engineering and Technology
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• v.28 no.7
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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.

• Proceedings of the IEEK Conference
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• 2009.05a
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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.

• Proceedings of the Korean Society for Language and Information Conference
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• 2007.11a
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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.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.572-582
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• 2017

It is definitely important to measure thrust during ground test when developing air-breathing engine, and in case of air-breathing engine, gross thrust should be calculated considering not only the measured thrust but also the force induced by the air flow of engine intake. Also, side thrust like yaw and pitch should be measured and analyzed using multi-component thrust measurement system. Engine performance was accurately evaluated by calculating the gross thrust of air breathing engine precisely which is analyzed from below serial procedure: labyrinth seal isolation, 1-axis gross thrust calculation, develop multi-component thrust measurement system, and side thrust analysis.

• Journal of Power System Engineering
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• v.3 no.3
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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.