• 산업공학
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• 제11권2호
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• pp.93-106
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• 1998

This paper suggests a stereo vision-based algorithm for the 3-dimensional inspection of a crimped terminal. The crimped terminal is one of wire harness assemblies which transmit current or signals between a pair of electrical or electronic assemblies. Four types of nonconformities considered includes terminal rolling, band up/down, twist, and crimp height. To obtain stereo image correspondence, an algorithm using Hough transform is proposed. Coordinate transform is then applied to evaluate the degree of 3-dimensional nonconformities. The algorithm has been successfully tested on a number of real specimens collected from a wire harness factory. The test results show the feasibility of the proposed algorithm.

• 한국음향학회:학술대회논문집
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• 한국음향학회 1994년도 FIFTH WESTERN PACIFIC REGIONAL ACOUSTICS CONFERENCE SEOUL KOREA
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• pp.854-859
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• 1994

As powertrain noise is better and better controlled, road noise inputs become more important. The interior road noise of a car is mainly induced by the wheels rolling over the road surface. Each of the four wheels act as an independent and uncorrelated excitation input. To rank the energy transfer form each input to the interior, a Transfer Path Analysis (TPA) needs to be made-which requires operational vibration measurements. However due to the multiple uncorrelated inputs, phase relations vary continuously. It is therefore necessary to separate the operational data into set of "independent phenomena" by means of a Principal Component Analysis (PCA). A TPA can then be carried out for each independent phenomenon. Operational deflection shapes referenced to these principal components share the physical phenomena. The details of the methodology are discussed and a discussion of the results on a car shows that the method gives accurate results for full vehicle testing.e testing.

• 한국철도학회논문집
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• 제19권3호
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• pp.280-287
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• 2016

지하터널에서 도시철도 운행 중 휠과 레일의 접촉에 의해 먼지가 발생되고, 이 먼지는 도시철도에 기인하는 열차풍에 의해 부유하고, 이 중 일부는 중력침강에 의해 바닥에 침착된다. 이 연구에서는 도시철도 터널에서 먼지농도의 일변화를 조사하였다. 도시철도 운행에 따른 먼지농도의 변화를 쉽게 관측하기 위하여 단일구간의 터널을 측정대상으로 선정하였다. 5nm에서 $20{\mu}m$ 범위의 먼지를 측정하기 위하여 4종류의 입자측정기를 사용하였다. 도시철도가 측정지점을 통과하는 시각을 정확히 파악하기 위하여 3차원 초음파 풍속계와 비디오 카메라를 사용하였다. $50{\mu}g/m^3$ 이하이던 지하터널의 먼지농도는 도시철도의 운행에 의해 $150{\mu}g/m^3$ 이상까지 유의하게 증가하였고, 특히 출근시간대에는 $250{\mu}g/m^3$ 이상으로 크게 높아졌다.

• 한국철도학회논문집
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• 제13권2호
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• pp.159-165
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• 2010

본 논문에서는 RAM(Reliability, Availability, and Maintainability)과 RCM(Reliability Centered Maintenance) 개념을 기반으로 하는 틸팅 열차 유지보수 시스템(TRMS; Tilting Rolling-stock Maintenance System)의 S/W 구축방안을 제시하였다. 먼저 RCM 개념 및 절차에 대하여 소개하고 TRMS S/W가 어떻게 이러한 개념과 절차를 구현하는지에 관하여 논하였다. TRMS는 네 개의 모듈 즉 시스템 및 운영정보 모듈, FMECA 모듈, RAM 정보 모듈, RCM 분석 모듈로 구성되어 있다. 시스템 및 운영정보 모듈에서는 RCM 분석의 기초 작업인 데이터 수집을 위한 인터페이스가 제공되고, FMECA 모듈에서는 시스템 및 운영정보 모듈의 고장 데이터를 이용하여 고장영향 분석을 할 수 있는 워크 스페이스(workspace)를 제공한다. RAM 모듈에서는 Weibull 분포의 신뢰성과 고장률을 산출하기위한 알고리즘이, RCM 분석모듈에서는 작업주기와 작업비용을 계산하기위한 계산식이 제안되었다. 유지보수 관계자들이 RCM의 장점을 충분히 인식한다면 RCM을 다른 전동차 유지보수 시스템에도 쉽게 적용할 수 있을 것이다.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1996년도 춘계학술대회
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• pp.199-202
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• 1996

Artificial hearts are intended for use in patients with severe forms of heart disease for which no surgical repair is possible. The moving-actuator pump was developed to decrease the overall volume size of the electromechanical total artificial heart (TAH) by eliminating the occupied space of the fixed-actuator in the conventional pusher-plate type pump. In our pump, the actuator moves back and forth for alternative ejections of left and right ventricles. The problem of fitting the TAH to atrial remnants and arterial vessels could also be improved by circular or penduluous mot ion of the actuator instead of linear mot ion of the pusher-plate in the conventional pumps. We have evaluated two types of moving- actuator pump; one is a rolling cylinder type, and the other a pendulum type pump. In the rolling cylinder pump, frictional energy loss exists between the pump housing's guide bars and the actuator's end caps, while the bottom rack under the cylindrical actuator increases the height of the pump, the pump is therefor not implantable inside the small chest of human-sized animals with a body weight of less than 70kg. The new human type pump has a penduluous mot ion actuator to correct the above problems while maintaining the advantage of the moving- actuator's small total volume. The totally implantable TAH is composed of a blood pump, a control system and pheriperal equipments. The blood pump, which is constructed by a moving actuator, a right and left blood sac, and four artificial valves, is implanted in the thoracic. In 1988, the first implantation of the rolling cylinder TAH was performed into a female calf weighing 100kg, and the cal f recovered to the degree of voluntary standing and eat ing and survived to 100 hrs. We then survived two female sheep weighing about 63kg with the new human type TAH for three days.

• 한국전문물리치료학회지
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• 제19권3호
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• pp.1-10
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• 2012

The aim of this study is to compare measurements of abdominal muscle thickness using ultrasonography imaging (USI) to those using a special transducer head device, during five different trunk stabilization exercises, ultimately to determine which exercise led to the greatest muscle thickness. Thirty eight healthy subjects participated in this cross-sectional study. The five types of trunk stabilization - i.e., a sit-up on the supine, an upper and lower extremity raise with quadruped on the prone, a leg raise in sitting on the ball, trunk rolling on the ball, and balance using sling on the prone position - were each performed with an abdominal draw. The thickness of the abdominal muscle - including the transverse abdominal (TrA), internal oblique (IO), and external oblique (EO) - was measured by USI with a special transducer head device, at rest and then at contraction in each position. Data were analyzed using one-way repeated ANOVA with the level of significance set at ${\alpha}$=.05. The results were as follows: 1) the TrA thickness was statistically significant (p<.05), whereas the IO and EO thicknesses were not (p>.05); 2) among the five types of trunk stabilization, TrA thickness significantly increased with the balance using a sling in the prone position, (p<.05), whereas no significant difference was noted for the four types of trunk stabilization (p>.05); 3) reliability data showed that there was a high degree of consistency among the measurements taken using the special transducer head device (ICC=.92). In conclusion, the balance using a sling in the prone position was more effective than any of the four other types of trunk stabilization in increasing TrA thickness in healthy subjects.

• 전기학회논문지
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• 제63권4호
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• pp.583-588
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• 2014

In this study, there are examined to the grounding of lightning protection system and electrical continuity tests in the field. The standard for lightning protection system is different design or construction according to the characteristics of the structure. Ground is measured and compared at least four locations. According to the measured results in the field, the sampled values of the ground resistance are measured $5{\Omega}$ or less and the difference between each value is suitable as $0.2{\Omega}$ or less. The values of the electrical continuity test between ground and metal bodies are measured 3 groups such as isolated portion, the mechanical contacted portion, and the electrical continuity portion measuring $0.2{\Omega}$ or less. It is measured to be less than $0.2{\Omega}$ at all in metal bodies of underground. A metal body installed inside the structure is not isolated, but the resistance values are higher than $0.2{\Omega}$. Therefore, It must be carried out the structure having lightning protection system confirm the LPL(lightning protection level) and design the strategy.

• 로봇학회논문지
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• 제6권4호
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• pp.323-333
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• 2011

Due to the limited pendulum motion range, the conventional one-pendulum driven spherical robot has limited driving capability. Especially it can not drive parallel direction with center horizontal axis to which pendulum is attached from stationary state. To overcome the limited driving capability of one-pendulum driven spherical robot, we introduce a spherical robot, called KisBot II, with a new type of curved two-pendulum driving mechanism. A cross-shape frame of the robot is located horizontally in the center of the robot. The main axis of the frame is connected to the outer shell, and each curved pendulum is connected to the end of the other axis of the frame respectively. The main axis and pendulums can rotate 360 degrees inside the sphere orthogonally without interfering with each other, also the two pendulums can rotate identically or independent of each other. Due to this driving mechanism, KisBot II has various motion generation abilities, including a fast steering, turning capability in place and during travelling, and four directions including forward, backward, left, and right from stationary status. Experiments for several motions verify the driving efficiency of the proposed spherical robot.

• IEIE Transactions on Smart Processing and Computing
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• 제1권2호
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• pp.78-87
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• 2012

In this paper, we address the tracking problem caused by camera motion and rolling shutter effects associated with CMOS sensors in consumer handheld cameras, such as mobile cameras, digital cameras, and digital camcorders. A modified particle filtering method is proposed for simultaneously tracking objects and compensating for the effects of camera motion. The proposed method uses an elastic registration algorithm (ER) that considers the global affine motion as well as the brightness and contrast between images, assuming that camera motion results in an affine transform of the image between two successive frames. By assuming that the camera motion is modeled globally by an affine transform, only the global affine model instead of the local model was considered. Only the brightness parameter was used in intensity variation. The contrast parameters used in the original ER algorithm were ignored because the change in illumination is small enough between temporally adjacent frames. The proposed particle filtering consists of the following four steps: (i) prediction step, (ii) compensating prediction state error based on camera motion estimation, (iii) update step and (iv) re-sampling step. A larger number of particles are needed when camera motion generates a prediction state error of an object at the prediction step. The proposed method robustly tracks the object of interest by compensating for the prediction state error using the affine motion model estimated from ER. Experimental results show that the proposed method outperforms the conventional particle filter, and can track moving objects robustly in consumer handheld imaging devices.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.590-595
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• 2007

It is important to predict the collision behavior of a train consist to improve its crashworthiness. To analyze crash behavior of train, four kinds of methods are mainly used so far. The first is method using multibody dynamics to predict the gross motion of the train set. The second uses 3D FE model to apply the section analysis method in order. The third is used to deduce design specification and evaluate the crashworhiness of a train by using 1D model. The last is to constitute 2D model to check overriding and coupling devices. The train evaluation procedures are so complex that it is difficult to understand or deal with. In this study, VTM for railway train was introduced to simplify the procedures. VTM involves 3D models, 1D models and dynamic components such as suspension and coupling. The method using hybrid concept model makes it possible to do all the things that are mentioned above. To analyze crash behavior tendency of VTM, the model was simulated and the simulation results were discussed.