• International Journal of Fuzzy Logic and Intelligent Systems
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• 제3권1호
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• pp.105-111
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• 2003

This paper is researching the storing of 40 different kinds of conditions. Such as, car speed, delay in starting time and the volume of cars in traffic. Through the use of a central nervous networking system or AI, using 10 different intersecting roads. We will improve the green traffic light. And allow more cars to easily flow through the intersections. Now days, with increasing many vehicles on restricted roads, the conventional traffic light creates prove startup-delay time and end-lag-time. The conventional traffic light loses the function of optimal cycle. And so, 30-45% of conventional traffic cycle is not matched to the present traffic cycle. In this paper proposes electro sensitive traffic light using fuzzy look up table method which will reduce the average vehicle waiting time and improve average vehicle speed. Computer simulation results prove that reducing the average vehicle waiting time which proposed considering passing vehicle length for optimal traffic cycle is better than fixed signal method which dosen't consider vehicle length.

• 한국가시화정보학회지
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• 제6권1호
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• pp.53-58
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• 2008

We carried out the experiments which controled the periodic jet in front of the fence to alter the fence wake. The experiments were performed in circulating water channel and the vertical fence was submerged in the boundary layer. The frequency, jet nozzle distance and speed of jet passing the slit were investigated. Each case divided into 20 phases and phase-averaged results were compared with uncontrolled fence flow. From the results, we found the specific frequency and nozzle distance which were good for reducing the reattachment length. In this case, the reattachment length was decreased 35% compared with the uncontrolled fence flow.

• Journal of Dental Anesthesia and Pain Medicine
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• 제22권6호
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• pp.427-435
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• 2022

Background: This study aimed to investigate the relationship between pharyngeal morphology and the success or failure of blind nasotracheal intubation using standard lateral cephalometric radiography and to analyze the measurement items affecting the difficulty of blind nasotracheal intubation. Methods: Assuming a line perpendicular to the Frankfort horizontal (FH) plane, the reference point (O) was selected 1 cm above the posterior-most end of the hard palate. A line passing through the reference point and parallel to the FH plane is defined as the X-axis, and a line passing through the reference point and perpendicular to the X-axis is defined as the Y-axis. The shortest length between the tip of the uvula and posterior pharyngeal wall (AW), shortest length between the base of the tongue and posterior pharyngeal wall (BW), and width of the glottis (CW) were measured. The midpoints of the lines representing each width are defined as points A, B, and C, and the X and Y coordinates of each point are obtained (AX, BX, CX, AY, BY, and CY). For each measurement, a t-test was performed to compare the tracheal intubation success and failure groups. A binomial logistic regression analysis was performed using clinically relevant items. Results: The items significantly affecting the success rate of blind nasotracheal intubation included the difference in X coordinates at points A and C (Odds ratio, 0.714; P-value, 0.024) and the ∠ABC (Odds ratio, 1.178; P-value, 0.016). Conclusion: Using binomial logistic regression analysis, we observed statistically significant differences in AX-CX and ∠ABC between the success group and the failure group.

• 한국소음진동공학회논문집
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• 제23권5호
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• pp.385-393
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• 2013

In this paper, the mechanism identification and the avoidance measures on the phenomena of transient acoustic vibration amplified at the water-supply piping system to regulate the steam temperature of the boiler reheater in 500MW class supercritical power plant are presented. The pressure pulsation waves induced by the impeller passing of two feed-water pumps with five blades are coincident with the local acoustic modes of boiler reheater water-supply piping system. There are the phenomena amplified at the peaks of 5X, 10X, 15X and 20X in spectrums of piping vibration, sound pressure, and the feed-water's pressure pulsation waves. The shut-off device is installed in the piping system for the interception of pressure pulsation waves transmitted from two feed-water pumps and the modified design change of the piping layout is applied for the acoustic resonance avoidance. The acoustic natural frequencies are separated from the harmonics of pressure pulsation waves induced by the pump impellers passing through the design change of the span length. The acoustic vibration is gone by resonance avoidance measures. As a result, more than 20 dBA reduction is achieved from 100 dBA to 80 dBA.

• 한국철도학회논문집
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• 제10권6호
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• pp.772-778
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• 2007

곡선통과 새마을호 열차의 마모 특성을 평가하기 위하여 다량 편성 해석모델이 사용된다. 이 모델과 ADAMS/Rail를 사용하여 마모 특성과 관련된 변수의 변화에 따른 민감도 해석이 수행된다. 저속에서 우측 차륜의 마모도와 미끄럼도가 좌측 차륜보다 높으나, 고속의 경우는 좌측 차륜이 우측 차륜보다 높다. 곡선반경의 감소에 따라 마모도와 미끄럼도가 증가한다. 완화곡선의 길이가 증가하련 마모도와 미끄럼도가 증가한다. 또한 캔트가 증가하면 마모도와 미끄럼도가 증가한다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 춘계학술대회논문집B
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• pp.599-604
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• 2000

In order to study unsteady aerodynamic loads on high speed trains passing by each other at the speed of 350km/h, three-dimensional flow fields around trains during the crossing event are numerically simulated using the three-dimensional Euler equations. The Roe's FDS with MUSCL interpolation is employed to simulate wave phenomena properly. An efficient moving grid system based on domain decomposition techniques is developed to analyze the unsteady flow field induced by the restricted motion of a train on a rail. The numerical simulations of the trains passing by on the double-track are carried out to study the effect of the train nose-shape, the train length and the existence of tunnel when the crossing event occur. Unsteady aerodynamic loads side force and drag force-acting on the train during the crossing are numerically predicted and anlayzed. It is found that the strength of the side force mainly depends on the nose-shape, and that of drag force on tunnel existence. And it is observed that the push-pull like impulsive force successively acts on each car and acts in different directions between the neighborhood cars. The maximum change of the impulsive force reaches about 3 tons. These aerodynamic force data are absolutely necessary for the evaluation of the stability of the high speed multi-car train. The results also indicate the effectiveness of the present numerical method for the simulation of unsteady flow field induced by the bodies in the relative motion.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2007년도 추계종합학술대회
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• pp.285-288
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• 2007

3차원 초음파 센싱에 의해 획득한 데이터로부터 물체의 부피를 자동으로 측정하고 분류적재 관리하는 임베디드시스템을 프로세서 기반으로 구현한다. 부피측정은 3개의 초음파 센서에서 획득한 데이터에서 높이와 폭은 물체가 컨베이어를 통과할 때 3 값을 기준 값과 비교하여 측정하고 길이는 물체가 처음 감지된 시점부터 범위를 벗어날 때까지의 시간을 물체의 이동속도에 대입하여 측정한다. 또한 센서의 온도 변화에 속도가 변하기 때문에 환경에 따라 보정하고 물체가 정방향이 아닐 경우 센싱값을 평균하여 오차를 줄인다. 실험은 직육면체를 기준하였으며 포장된 물류를 크기별로 분류하고 창고 및 이동체에 적재 할 경우 실용적으로 활용가능성을 높인다.

• 한국철도학회논문집
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• 제10권5호
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• pp.492-498
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• 2007

곡선통과 새마을호 열차의 주행안전성을 평가하기 위하여 다물체동력학 해석모델이 사용된다. 이 모델과 ADAMS/Rail 사용하여 탈선계수와 관련된 변수의 변화에 따른 민감도해석이 수행된다. 저속에서 우측차륜의 탈선계수와 윤중감소율이 좌측차륜보다 높으나, 고속의 경우는 좌측차륜이 우측차륜보다 높다. 곡선반경의 감소에 따라 탈선계수와 윤중감소율이 감소된다. 완화곡선의 길이가 증가하면 탈선계수는 증가하나 윤중감소율은 변화가 없다. 캔트가 증가하면 탈선계수와 윤중감소율이 증가한다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.2064-2071
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• 2011

We are developing an innovative super-speed land transportation system running in a partial vacuum in tunnels with small inside diameter to reduce the aerodynamic drag forces. This paper presents the experimental results obtained on a small scale model when a super-speed train model passing through a tunnel with small inside diameter and a partial vacuum to reduce the aerodynamic drag forces. The experiments were performed on a 1/52-scale moving model rig in which a train model with a diameter of 58 mm and a length of 603 mm was accelerated in a launching tube with 12.27 m length by means of the compressed air launcher and then passed through a tunnel model with 17.149 m length. The partial vacuum was maintained in the tunnel in order to reduce the energy consumption of the propulsion system of the super-speed tube train at super-speed of 700 km/h. In this study, the blockage ratio of train to tunnel model is 0.336. Experimental results show the nonlinear effects of the vacuum on the speed-up of the train model in the tunnel model under the partial vacuum up to 0.21 atm and at the velocity up to 684 km/h. This paper is first study for experiments on the speed-up of a super-speed train model in the partial vacuum tunnels.

• 한국소음진동공학회논문집
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• 제17권7호
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• pp.632-637
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• 2007

The dynamic behavior of two steel bridges crossed by the Korean High Speed Train(KHST) has been investigated experimentally and the results are compared with the specification requirement of BRDM and other typical PSC Box bridge's responses. The investigated bridges are a 2-girder steel bridge of 1@40m span length(E-Won Bridge), 2@50m span length (Ji-Tan Bridge), and a PSC Box girder bridge of 2@40m span length (Yeon-Jae Bridge). A set of experimental tests were performed during operation of KHST, and a number of accelerometers, LVDTs and ring-type displacement transducers were utilized for measurement of three kinds of dynamic responses (acceleration, deflection, and end-rotation angle). Measured responses show that the vertical deflections and end-rotation angles of the three bridges are all satisfying the spec. requirement with large margin, but it was also found acceleration responses which are very close or exceed the limit value. Most of the excessive acceleration responses were found when the passing velocity of the KHST is close to the critical velocity ($V_{cr}$) which causes resonance. No noticeable differences of dynamic responses due to the different materials(steel or concrete) could be found within these experimental results.