• 한국가시화정보학회:학술대회논문집
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• 한국가시화정보학회 2003년도 추계학술대회 논문집
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• pp.111-114
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• 2003

Drop size is one of the most important parameters which are control the performance of the engine using liquid fuel/oxidizer and drop formation is mainly controlled by aerodynamic force caused by ambient gas. Because of this, empirical data and correlation acquired under standard ambient condition are not valid. So experiments under high ambient pressure condition to measure the drop size using image processing method And find the empirical correlation between SMD and chamber pressure(density), injection velocity.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2003년도 추계학술대회논문집
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• pp.730-734
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• 2003

A beamforming method is a kind of spatial filter that focus the amy's signal capturing abilities in a desired direction. In this paper, we detect the location of a source under reflective condition using the multi-dimensional MUSIC algorithm then, we can iud the image source locations from the experimental geometry, and we reconstruct the partial fields for direct wave and reflected wave by using Adaptive nulling algorithm. Numerical simulations are performed to verify its performance under various conditions.

• Computers and Concrete
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• 제18권1호
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• pp.69-97
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• 2016

Performance-based remaining life assessment of reinforced concrete bridge girders, subject to chloride-induced corrosion of reinforcement, is addressed in this paper. Towards this, a methodology that takes into consideration the human judgmental aspects in expert decision making regarding condition state assessment is proposed. The condition of the bridge girder is specified by the assignment of a condition state from a set of predefined condition states, considering both serviceability- and ultimate- limit states, and, the performance of the bridge girder is described using performability measure. A non-homogeneous Markov chain is used for modelling the stochastic evolution of condition state of the bridge girder with time. The thinking process of the expert in condition state assessment is modelled within a probabilistic framework using Brunswikian theory and probabilistic mental models. The remaining life is determined as the time over which the performance of the girder is above the required performance level. The usefulness of the methodology is illustrated through the remaining life assessment of a reinforced concrete T-beam bridge girder.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 춘계학술대회 논문집
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• pp.881-888
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• 1997

A new algorithm for detection of tool fracture in milling process was developed. The variation of the peak-to-valley value of cutting load was used in this algorithm. Various kinds of vectors representing the condition of tool, such as tool condition vector, reference tool condition vector, tool condition variation vector were defined. Using these vectors, tool fracture index which represents the magnitude of tool fracture and is independent of tool run-outs is developed. Small and large tool fracture and chipping under various cutting condition could be detected using proposed tool fracture index, which was proved with cutting force model and experiments.

• Tribology and Lubricants
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• 제20권1호
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• pp.21-26
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• 2004

The average frictional coefficient was used generally to analyze the working process of the lubricated machine parts. But it is difficult of taking the correct frictional coefficient because the average frictional coefficient of it is progressed always unstably with a large amplitude on working condition. If the correct analysis of frictional coefficient on working condition for the lubricated machine parts can be possible, it can be effect on condition diagnosis of lubricated machine system. This study was carried out to get the optimum working condition of the hydraulic actuator parts using statistical techniques. From this result, it has the lowest friction coefficient in case of applied load of 3 kg and sliding speed of 120 mm/sec.

• 한국지반환경공학회 논문집
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• 제15권8호
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• pp.45-50
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• 2014

하수관 내에서의 하수와 미생물의 반응에 대한 실험은 이미 매설된 하수관에 적용할 경우 실험조건의 변화가 제한적이며 실험시간에도 한계가 있다. 본 연구에서는 이러한 하수관 내에서의 하수와 미생물의 반응에 대하여 DO를 제한 조건으로 설정하였을 경우, 실험실 내에서 실험반응조를 통해 재현하는 방법에 대하여 연구하였다. 하수관 내에서의 DO 농도는 기상 중의 산소가 하수 내로 이동하는 재포기현상에 의해 조절된다. 이러한 현상을 이용하여 임의로 실험반응조에서 하수관 내의 유하조건을 조절하고 재포기현상을 재현하여 유하조건과 재포기계수와의 상관관계를 얻을 수 있으며, 교반강도(속도경사)에 따른 재포기계수와 하수관거에서의 유하조건에 따른 재포기계수의 상관관계를 통해 동일한 재포기계수 값을 갖는 교반강도와 유하조건을 설정할 수 있다. 이러한 결과를 통해 재포기계수를 제한인자로 설정하여 실험을 실시할 경우 하수관거에서의 상황을 실험반응조를 통해 재현할 수가 있었다.

• 전기학회논문지
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• 제58권11호
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• pp.2266-2268
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• 2009

In this paper, a simple method of angle velocity estimation is presented for a passive dynamic biped robot. The estimation problem is not an easy task because its dynamic model is a hybrid system involved with an impact condition. Instead of designing a complex observer for hybrid systems we simply utilize the impact condition to reset the initial condition of the high-pass filter when the non-support leg hits the slope. The approach has been verified by simulation results.

• 전기학회논문지
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• 제56권3호
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• pp.451-456
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• 2007

This paper presents a problem that reconfigure distribution power system using branch exchange method. Optimal reconfiguration problem calculates line loss, voltage condition about system states of all situations that become different according to line On/off status, and search for optimum composition of these. However, result is difficult to be calculated fast. Because radiated operation condition of system is satisfied using many connection and sectionalize switches in the distribution power system. Therefore, in this paper, optimization method for reducing system total loss and satisfying operating condition of radial and constraints condition of voltage is proposed using the fastest branch exchange. And optimal solution at branch exchange algorithm can be wrong estimated to local optimal solution according to initial operating state. Considering this particular, an initial operating point algorithm is added and this paper showed that optimal solution arrives at global optimal solution.

• 한국국방경영분석학회지
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• 제26권1호
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• pp.125-144
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• 2000

Occasionally, there are combat situations which one or both forces can´t terminate the combat using selected combat termination rule according to given relationship between ratio of attrition rate coefficient and threshold values. In this study, we classify the situations that one or both forces can´t terminate the combat with selected combat termination rule into four conditions. Condition${\circled1}$ is the situation which both Blue and Red can terminate the combat using all selected combat termination rules. condition${\circled2}$ and condition${\circled3}$ are those which neither Blue or Red can terminate the combat using selected proportional decision rule, and condition${\circled4}$ is that which both Blue and Red can´t terminate the combat using selected proportional decision rule. We analyze the effect of combat termination rules on parity number, final combat power, and combat durations for each conditions. Also, we propose the method to apply the analyzed effect of combat termination rules to combat analysis.

• 한국정보기술학회 영문논문지
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• 제8권2호
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• pp.47-58
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• 2018

In this paper, we propose a method for skin condition analysis using a camera module embedded in a smartphone without a separate skin diagnosis device. The type of skin disease detected in facial image taken by smartphone is acne, pigmentation, blemish and flush. Face features and regions were detected using Haar features, and skin regions were detected using YCbCr and HSV color models. Acne and flush were extracted by setting the range of a component image hue, and pigmentation was calculated by calculating the factor between the minimum and maximum value of the corresponding skin pixel in the component image R. Blemish was detected on the basis of adaptive thresholds in gray scale level images. As a result of the experiment, the proposed skin condition analysis showed that skin diseases of acne, pigmentation, blemish and flush were effectively detected.