• 대한기계학회논문집
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• 제14권6호
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• pp.1455-1463
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• 1990

In this study the feasibility of a dynamic gait for a given quadruped walking robot is investigated through a computer simulation of the walking with certain drivings of the actuators. Two planar inverted pendulums are used to represent the dynamic model of the leg of the walking robot. It's gait motion is assumed to be periodic and symmetric between left and right sides only with half cycle delay. The dynamics of the walking robot is simplified by introducing two virtual legs to produce two planar inverted pendulums in two orthogonal planes and on the basis that certain legs in pair act as one. The feasibility of the dynamic gait motion is established from the following two necessary conditions:(1) The position and velocity of a foot must satisfy the stroke and velocity requirements.(2) The gait motion should be periodic without falling down. The gait feasibility test was applied to a walking robot design showing the specific acceptable speed range of the robot in trot. Also it showed that the higher body height may produce the faster trot gait.

• Korea-Australia Rheology Journal
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• 제16권2호
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• pp.75-83
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• 2004

The purpose of the present study is to investigate fluid mechanical interactions between two major abdominal aortic branches under both steady and pulsatile flow conditions. Two model branching systems are considered: two branches emerging off the same side of the aorta (model 1) and two branches emerging off the opposite sides of the aorta (model 2). At higher Reynolds numbers, the velocity profiles within the branches in model 1 are M-shaped due to the strong skewness, while the loss of momentum in model 2 due to turning effects at the first branch leads to the absence of a reversed flow region at the entrance of the second branch. The wall shear stresses are considerably higher along the anterior wall of the abdominal aorta than along the posterior wall, opposite the celiac-superior mesenteric arteries. The wall shear stresses are higher in the immediate vicinity of the daughter branches. The peak wall shear stress in model 2 is considerably lower than that in the model 1. Although quantitative comparisons of our results with the physiological data have not been possible, our results provide useful information for the localization of early atherosclerotic lesions.

• 대한전기학회논문지:시스템및제어부문D
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• 제54권8호
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• pp.517-520
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• 2005

Cleft lip is a congenital deformity condition with separation of the two sides of the lip and results in nose deformity Evaluation of surgical corrections and outcome assessments in nose deformity resulting from the cleft lip depend mainly on doctor's objective judgment. Development of an objective assessment tool in evaluation of the condition and surgical outcome of cleft lip nose deformity patients will help in advancement and evaluation of surgical techniques of cleft lip. Hence, our study aimed at quantitative assessment of a cleft lip nose deformity condition by comparing following parameters gathered from a photographic image of a cleft lip patient: (1) angle difference between two nostril axis, (2) center of the nostril and distance between two centers, (3) overlapped area of two nostrils and (4) the overlapped area ratio of two nostrils. Assessment results of the nose deformity were determined by statistical analysis of evaluation results from three experienced plastic surgeons. In addition, regression model was developed using correlation relationship and factor analysis of parameters from results of the image analysis

• 한방안이비인후피부과학회지
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• 제14권2호
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• pp.183-193
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• 2001

Background: Ramsay Hunt syndrome is a disease that cause faical palsy, ear pain, ear vesicle, tinnitus, hardness of hearing by geniculate ganglion herpes. Ramsay Hunt syndrome could be taken two sides view of herpes zoster and facial palsy. In traditional oriental medicine Ramsay Hunt syndrome could be diagnosed as heat and dryness syndromes. Object: These studies are clinical observations about two Ramsay Hunt syndrome patient cases that is recovered under the treatment by herbal-acupuncture therapy and moxibustion. Methods: For treatment in acute state, acupuncture therapy was used and in convalescent stage, herbal acupuncture therapy and moxibustion therapy were used. For diagnosis system, House-Brackmann system, Yanagihara's system used as diagnosis scales. Result&Conclusion: The results as follows. 1. Generally, to treat Ramsay Hunt syndrome, it is knwon that from invasion of virus to period of first effect a short term bring about good result, but in these two cases, though a long term. considerable effect was braught out. 2. In treating two cases, herbal acupuncture therapys what are called CF, JSD were used. satisfactory results was produced.

• Nuclear Engineering and Technology
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• 제41권6호
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• pp.841-848
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• 2009

A simple model to analyze non-linear density-wave instability in a sodium-cooled helically coiled steam generator is developed. The model is formulated with three regions with moving boundaries. The homogeneous equilibrium flow model is used for the two-phase region and the shell-side energy conservation is also considered for the heat flux variation in each region. The proposed model is applied to the analysis of two-phase instability in a JAEA (Japan Atomic Energy Agency) 50MWt No.2 steam generator. The steady state results show that the proposed model accurately predicts the six cases of operating temperatures on the primary and secondary sides. The sizes of three regions, the secondary side pressure drop according to the flow rate, and the temperature variation in the vertical direction are also predicted well. The temporal variations of the inlet flow rate according to the throttling coefficient, the boiling and superheating boundaries and the pressure drop in the two-phase and superheating regions are obtained from the unsteady analysis.

• 대한정형외과학회지
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• 제54권3호
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• pp.261-268
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• 2019

목적: 정상 한국 성인의 컴퓨터 단층촬영 영상으로 비구 전경사, 대퇴 경부 전경사 및 합산 전경사의 값을 구한 뒤 정상 범위와 남녀간의 차이, 좌우측의 차이 및 대퇴 경부 전경사와 비구 전경사와의 상관관계를 분석하고자 하였다. 대상 및 방법: 한국 정상 성인 중 21세에서 49세 범위 내의 남자 118명과 여자 114명의 컴퓨터 단층촬영 영상을 이용하여 좌우측의 비구 전경사, 대퇴 경부 전경사를 측정하고, 합산 전경사를 계산하여 각 측정값의 평균과 표준편차를 구하고 남녀 간의 차이, 좌우측의 차이가 있는지와 비구 전경사와 대퇴 경부 전경사 간의 상관관계를 통계적으로 분석하였다. 결과: 비구의 전경사는 남자에서 우측 15.3±6.1도, 좌측 15.3±6.6도, 대퇴 경부 전경사는 Hernandez 등의 방법으로 측정한 경우 우측 5.3±7.6도, 좌측 1.5±9.2도였으며 여자에서 비구 전경사는 우측 16.8±5.4도, 좌측 16.3±5.8도, 대퇴 경부 전경사는 Hernandez 등의 방법으로 측정한 경우 우측 10.3±8.2도, 좌측 7.9±8.2도였다. 남녀 간의 차이분석 시 좌우측 모두 비구 전경사는 통계적으로 차이가 없었으며 대퇴 경부 전경사는 좌우측 모두 통계적으로 의미있는 차이가 있었다. 좌측과 우측을 비교하였을 때 비구 전경사는 차이가 없었으며 대퇴 경부 전경사는 Hernandez 등의 측정법이나 Weiner 등의 측정법 모두 좌우측 간에 통계적으로 차이가 있는 것으로 나타났다. 대퇴 경부 전경사와 비구 전경사 간의 상관관계를 보기 위하여 피어슨 상관계수를 구하였으며 그 결과 상관관계가 없는 것으로 나타났다. 결론: 남녀 간의 비구 전경사는 통계적인 차이가 없었고 대퇴 경부 전경사는 차이가 있었다. 개인별로는 좌우측 간에 대퇴 경부 전경사가 의미 있는 차이가 있었고 비구 전경사는 차이가 없었다. 대퇴 경부 전경사와 비구 전경사 간에는 상관관계가 없었다.

• International Journal of Fluid Machinery and Systems
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• 제6권3호
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• pp.121-136
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• 2013

This paper reports the 1-D fluid transient simulation results of the discharge flow conditions in a 6-cylinder reciprocating slurry pump. Two discharge manifold configurations are studied comparatively; a case with a hexagon shaped discharge manifold where each cylinder discharges at a single vertex, and a case where all the cylinders discharges are lumped together into a tank shaped manifold. In addition, the study examines the effect of two pulsation mitigation measures in the case of hexagonal manifold; a single inline orifice in one of the hexagon sides and a volumetric dampener at the manifold outlet. The study establishes the pressure and flow fluctuation characteristics of each configuration and decouples the pulsation characteristics of the pump and the discharge manifold.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 2000년도 THE THIRD INTERNATIONAL CONFERENCE ON AGRICULTURAL MACHINERY ENGINEERING. V.III
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• pp.707-714
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• 2000

For self-guiding track-type orchard sprayer, a low-cost steering controller was developed using two ultrasonic sensors, two DC motors and 80196kc microprocessor. The operating principle of controller was to travel the sprayer between artificial targets such as wood stick placed every 1 m along both sides of the demanded path of speed sprayer. Measuring distances to both targets ahead with the ultrasonic sensors mounted on the front end of sprayer, the controller could determine how much offset the position of sprayer was laterally. Then the steering angle was calculated to actuate DC motors connected to the steering clutches, where the fuzzy control algorithm was used. Equipped with the controller developed in this research, the sprayer could be traveled along demanded path, the centerline between targets, at speeds of up to 0.4m/sec with an accuracy of ${\pm}$20cm.

• 한국항해항만학회지
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• 제35권4호
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• pp.299-302
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• 2011

In this letter, the effect of quality factor on center frequency deviation in miniaturized coupled line bandpass filter (BPF) with diagonally end-shorted at their opposite sides and lumped capacitors is theoretically analyzed. The miniaturized BPF of a two-stage structure with two types of quality factors in standard CMOS process was designed and manufactured at 5.5 GHz. The die area of BPF was $1.44{\times}0.41\;mm^2$. The measured center frequency of BPF with a quality factor of 4.9 was deviated from 5.5 GHz to 4.7 GHz. The one with 14.8 was shifted to 5GHz. The theoretical and measured results validate that quality factor influences the center frequency shift of BPF.

• Journal of Electrical Engineering and Technology
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• 제11권1호
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• pp.150-156
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• 2016

This paper compares the performances of permanent-magnet synchronous (PMS) and permanent-magnet vernier (PMV) machines for low-speed and high-torque applications. For comparison with the PMS machines, we consider two types of the PMV machine. The first one has surface-mounted permanent magnets (PMs) on the rotor and the other has PMs inserted on both sides of the stator and rotor. The PMS and PMV machines are designed to meet the condition of equal output power per unit volume. We analyze the magnetic fields of the machines using a two-dimensional finite element analysis (FEA). We then compare their performances in terms of the generated torque characteristics, power factor, loss, and efficiency.