• 한국전자파학회지:전자파기술
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• 제14권1호
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• pp.35-42
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• 2003

Differential signaling has become a popular choice for high-speed interconnection schemes on Printed Circuit Boards (PCBs), offering superior immunity to external noise. However, conventional differential transmission lines on PCBs have problems, such as crosstalk and radiated emission. To overcome these, we propose a Twisted Differential Line (TDL) structure on a multi-layer PCB. Its improved immunity to crosstalk noise and the reduced radiated emission has been successfully demonstrated by measurement. The proposed structure is proven to transmit 3 Gbps digital signals with a clear eye-pattern. Furthermore, it is subject to much less crosstalk noise and achieves a 13 dB suppression of radiated emission. Index Terms - Twisted Differential Line, Differential Signaling, Crosstalk, Radiated Emission, Transmission Line, Twisted Pair

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2008년도 춘계학술대회논문집
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• pp.138-141
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• 2008

The screen doors installed in the station of subway are subject to the train-wind pressure caused by the operation of trains. The train-wind pressure has to be correctly estimated for the design of safe structure of screen doors. As three-dimensional numerical flow analysis technology has been significantly developed, the analysis on the train-wind pressure with diverse variables such as train specifications, train speed, tunnel and station configurations, and blockage ratio can be effectively carried out with three-dimensional numerical method. In this study, computational analysis of train-induced wind in a subway tunnel employing the screen doors are carried out by using the three-dimensional numerical method with the model of the moving boundary for the run of trains. While the numerical analysis of train-wind pressure was applied on the one island-type station in the Seoul Subway Line 2, maximum pressure of 494 Pa was estimated on the screen door when two trains pass each other at the speed of 80km/h in the platform.

• 한국기계가공학회지
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• 제19권3호
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• pp.105-110
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• 2020

Alumina, a typical ceramic material used for semiconductors and display parts, is the subject of research and development efforts for mineral material processing. Alumina is extremely difficult to process since it is brittleness to either fine ceramics material. We have studied the shape of diamond particles and their use in machinability for alumina processing. Our study was carried out under various processing conditions, including cutting speed, table speed, and the surface roughness of the work piece. We also analyzed the wear characteristics of the tool by total cutting.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 춘계학술대회 논문집
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• pp.323-324
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• 2006

This paper presents dynamics of register error on a compensator roll type converting machine. Though a register control is an important aspect of a converting machine, it has not been taken into account as a main subject. Lately, demands for high speed converting machines over 500mpm(m/min) are raising but domestic converting industries can not come up with the high speed machines because capacities fur designing of the converting machine is restricted lower than 300mpm. Moreover register control is the key to product flexible displays through roll-to-roll systems. In this paper, a compensator roll type register controller is analyzed using mathematical model of register error. A case study for reducing transient register errors is discussed.

• 한국자동차공학회논문집
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• 제8권3호
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• pp.139-150
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• 2000

Although a number of neck injuries are generated, the data which quantify the kinematic response of the human head and cervical spine in low-speed rear-end automobile collisions is very limited. On this problem, just few in vitro experimental research or some experimental research using dummy on neck injury by rear-end collision was conducted, thus systematic research is requested on full scale injury mechanism. An occupant model for the response of the occupant subject to rear-end collision using commercial dynamics package DADS was developed. Developed model shows more close agreement with the experimental data compared with the MADYMO simulation results for the cases of ${\delta}V=16$ kph in sled test. For the case of ${\delta}V=8$ kph and 33.5 kph with production seat, model also shows its reliable response compared with experimental results using Hybrid III and Hybird III with RID.

• Fibers and Polymers
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• 제3권2호
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• pp.80-84
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• 2002

Tension control is an important factor in producing high quality knitted products and in maintaining good processing condition. Yarn tension during knitting is subject to be affected from many elements of the machine and process parameters. Several factors including yam feeding speed, feeding angle, and needle gauge that are considered to influence on the tension variation were investigated. Yam feeding speed did not show high contribution to the tension variation but feeding angle of yam did show high correlation with the tension. No or negative correlation of the tension with needle gauge was found from the results. In order to keep well-determined process condition in the knitting manufacturing, it is strongly suggested that all knitting elements and parameters should be in the integrated control circumstance.

• Journal of Mechanical Science and Technology
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• 제18권7호
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• pp.1159-1168
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• 2004

In this paper, a spectral element model is derived for the axially moving viscoelastic beams subject to axial tension. The viscoelastic material is represented in a general form by using the one-dimensional constitutive equation of hereditary integral type. The high accuracy of the present spectral element model is verified first by comparing the eigenvalues obtained by the present spectral element model with those obtained by using the conventional finite element model as well as with the exact analytical solutions. The effects of viscoelasticity and moving speed on the dynamics of moving beams are then numerically investigated.

• 한국철도학회:학술대회논문집
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• 한국철도학회 1998년도 추계학술대회 논문집
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• pp.464-475
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• 1998

The study was carried out about the design of Power Car for Korean High Speed Train of maximum operating speed of 350㎞/h. At 350㎞/h, air resistance accounts for by far the greater part of overall resistance to forward motion. So, The Power Car's shape has to be largely determined by aerodynamic considerations. In a multiple unit such as the KHST, the two power cars assume the role of a locomotive. They accommodate all the machinery for providing traction. The train is controlled and monitored from power cars. The mechanical portion of KHST Power Car is the subject of this paper, which focuses on aerodynamics, mass balance, the car body and the layout of the equipment that is fitted into power car.

• Journal of applied mathematics & informatics
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• 제2권1호
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• pp.3-10
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• 1995

Nonlinear hyperbolic differenctial equations have been a subject of intense research in the field of gas dynamics due to many engineering problems associated with high-speed airplanes missiles materials processing etc. Recently phenomena known from gas dy-namics are found to occur also in the microeletronic devices such as MOSFET. Here a few interesting mathematical problems are presented along with future areas of research.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 2001년도 추계학술대회 학술발표 논문집
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• pp.177-180
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• 2001

The subject of this paper is to efficient Pm duty contort for two DC motor synchronousness in the system. Fuzzy controller have been successfully applied to many uncertain and complex industrial plant. So, It adapted fuzzy controller using compositional fuzzy rule so that change PH duty for speed control if the length of destination is different, And for unknow plant, it is the study to make the unknow transfer function system with fuzzy control method. This controller has been successfully applied to Pm duty control for the system synchronousness.