• 한국빅데이터학회지
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• 제2권2호
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• pp.129-140
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• 2017

낮은 시정, 강우, 강풍, 고온 등 기상 상태는 운전 능력, 차량 성능(예: 마찰, 안정성, 조작력), 노면 마찰력, 도로 인프라, 추돌 위험, 교통 흐름 및 도로 관리자 생산성 등에 영향을 미친다. 최근에는 CCTV, 도로 센서, 차량 센서 등 다양한 도로 기상 빅데이터 소스들이 개발되면서 이러한 기상 관련 문제들 해결에 적용되고 있다. 본 연구는 이러한 도로 기상 빅데이터 소스들의 유형과 특징을 정의하고 국내외 실증 사례들을 통해 도로 기상 빅데이터 유형별로 관련 문제들 해결에 활용하는 전략에 대해 제시하고자 한다.

• 전자공학회논문지C
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• 제36C권3호
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• pp.17-25
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• 1999

본 논문에서는 기존의 bit-serial 방식 곱셈기 및 나눗셈기의 하드웨어 부담을 줄이고 동일한 연산 사이 클 수를 갖는 새로운 bit-serial 방식의 곱셈기 및 나눗셈기 아키텍쳐를 제안한다. 제안하는 bit-serial 곱셈 및 나눗셈기 아키텍쳐는 부분곱 또는 부분나머지를 구하기 위해 레지스터 및 가감산기의 비트 수를 2배 확장하지 않기 때문에 기존의 아키텍쳐에 비해 하드웨어의 부담을 줄였다. 또한 덧셈/뺄셈과 Shift 연산을 동시에 수행하므로써 {{{{ { N}_{ } }}}} 비트 곱셈 및 나눗셈 연산에 각각 ,{{{{ { N}_{ } }}}},{{{{ { N}_{ } }}}}＋ 2 사이클을 소모하며 이는 기존의 아키텍쳐와 동일한 연산 사이클 수를 지원한다. 제안하는 bit-serial 곱셈기 및 나눗셈기 아키텍쳐는 SliM Image Processor에 적용하여 실제 칩으로 구현하였으며 그 성능을 입증하였다.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 1998년도 추계학술대회 논문집
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• pp.204-209
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• 1998

The acceleration of the performance of machine tools influences the development of the semi-conductor and optical technology as the development of NC and measurement technology. We can mention that a traction role of the acceleration for the development like that depends on the development of the measurement technics Stylus instrument method, STM, SEM, Laser interferometer method which are used for measuring the quasi-static error of machine tools. Because the measurement has been done to unload condition without considering of mechanical stiffness in the case of machining center as we measure the quasi-static error of machine tools on general studies, people who works on the spot has many problems on the data value. Therefor we will help working more accurately on the spot by measuring, analyzing, displaying the deflection of the table and support shaft when we load on the table and the support shaft of machining center using laser interferometer. Also we try to settle new conception of the measurement method and more accurate grasp of the deflection tendency by verifing the tendency of the error measured through the comparison of the simulated error using ANSYS, a common finite element analysis program, which is able to measure heat deformation, material deformation, and error resulted form this study.

• 한국의류학회지
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• 제18권3호
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• pp.368-386
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• 1994

The primary purpose of this study was to identify the diversity and embellishment of American Indian clothing and relationship between culture and clothing in American Indian Culture Areas. After the introduction of European material culture, change in American Indian clothing was conducted. The result of the Study as follows: 1. The most influential factors affecting the diversity of American Indian clothing were environmental factors. Climates and geographical features, Raw material were reflected in clothing style and clothing material in each culture Area. 2. Economic situation and life style were shown to be influential to clothing development. The best known instance of this was greatly elaborated clothing and personal adornment of the Plains who had higher stand of life and nomadic life style. 3. Religious concepts were important factors influencing American Indian clothing. Indian tribes had different ritual performance they used particular motifs in clothing. Clothing, such as "ghost shirt", Apache medicine shirt and Pueblo ceremonial clothing, served hidden pur- poses. 4. Techenology was another factor identified in this study as influencing American Indian clothing. Especially, weaving skills of Southwest played a great role in textile development. Pueblo "manta" and Navaho "bil" were famous for Indian costume. 5. European material culture allowed great change of traditional native Indian clothing. American Indian had new material, new styles, new concept of clothing. 6. American Indian, although Indian applicated European trade goods, was actually quite conservative in retaining traditional designs and modes of decoration. Asthetics and traction of American Indian were reflected in American Indian clothing.d in American Indian clothing.

• Earthquakes and Structures
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• 제11권5호
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• pp.841-859
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• 2016

Bridge bearings are important connection elements between bridge superstructures and substructures, whose health states directly affect the performance of the bridges. This paper systematacially presents a new method to identify the bridge bearing damage based on the neural network theory. Firstly, based on the analysis of different damage types, a description of the bearing damage is introduced, and a uniform description for all the damage types is given. Then, the feasibility and sensitivity of identifying the bearing damage with bridge vibration modes are investigated. After that, a Radial Basis Function Neural Network (RBFNN) is built, whose input and output are the beam modal information and the damage information, respectively. Finally, trained by plenty of data samples formed by the numerical method, the network is employed to identify the bearing damage. Results show that the bridge bearing damage can be clearly reflected by the modal information of the bridge beam, which validates the effectiveness of the proposed method.

• 연구논문집
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• 통권26호
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• pp.5-14
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• 1996

Test results of electromagnetic suspension (EMS) type urban transit maglev system are reported. Electromagnetic levitation system is a transportation system taking advantage of the attraction of normal conducting electromagnets to support and guide the train in combination with the linear induction traction motors. Urban Transit Maglev (UTM) Which is being developed by the maglev team in KIMM and the Hyundai Precision Company since 1995 consists of three bogies. In the first year, two types of Bogies are developed. Bogie I uses an analog controller for levitation and guidance control and is driven by two linear induction motors (LIM) mounted on the right and left side of module. Bogie II uses a digital controller and is driven by one LIM mounted along the center line of the bogie. Test results reported in this paper are those obtained with Bogie II with a digital controller. Also included in this paper is a brief explanation of the electromagnetic suspension levitation system which is being developed by the maglev team in KIMM.

• Journal of Power Electronics
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• 제16권2호
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• pp.542-552
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• 2016

Central 60° synchronous modulation is an easy pulse-width modulation (PWM) method to implement for the traction inverters of urban rail trains at a very low switching frequency. Unfortunately, its switching patterns are determined by a Fourier analysis of assumed steady-state voltages. As a result, its transient responses are not very good with over-currents and high instantaneous torque pulses. In the proposed solution, the switching patterns of the conventional central 60° modulation are modified according to the dynamic error between the target and actual stator flux. Then, the specific trajectory of the stator flux and current vector can be guaranteed, which leads to better system transients. In addition, stator flux control is introduced to get smooth mode switching between the central 60° modulation and the other PWMs in this paper. A detailed flow chart of the control signal transmission is given. The target flux is obtained by an integral of the target voltage. The actual PMSM flux is estimated by a minimum order flux state observer based on the extended flux model. Based on a two-level inverter model, improved rules in the α-β stationary coordinate system and equations of the switching patterns amendment are proposed. The proposed method is verified by simulation and experimental results.

• 한국자동차공학회논문집
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• 제19권5호
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• pp.125-133
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• 2011

The wear of rubber track being in contact with the road surface is an important subject because it decreases the traction performance and the operating efficiency of tracked vehicle. For the above reasons, many attempts have been made to quantitatively calculate the rubber track. However, it depends on the experimental methods which are highly time- and cost-consuming. Therefore, the numerical simulation approach is highly desirable, but it needs to model the complex geometry and the material behavior in details as well as the interaction with the road surface. In this study, the rubber track and its material behavior are elaborately modeled since these factors are very important in the prediction of the wear rate of the rubber track. Accordingly to the studies on the rubber wear by previous investigations, it has been found that the wear is greatly influenced by the frictional energy. The frictional energy of rubber track is computed by utilizing the 3D finite element analysis of the rubber track, and the wear rate is evaluated making use of the frictional energy and a wear model.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 춘계학술대회 논문집
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• pp.1209-1212
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• 2008

동력분산형 고속전철은 분산된 EMI 발생원(source)을 가지도록 제작되기 때문에, 분산된 전자계 감수품(感受品, victim) 가까이에서 기존의 동력집중형 시스템보다 전자계 발생원을 더 많이 가지고 있다. 이 연구에서는, 전자계 발생원들과 전자계 감수품들을 확인하고, 고속전철 시스템의 안전 운행을 위하여 EMI/EMS/EMC를 취급하는 방법을 개발한다. 개발되는 내용은, 고속전철의 전자파 장해 방지 측정과 기준연구, 제어용 부품 등에 대한 EMI/EMS 기준 수립, 그리고 시제품에 대한 EMI/EMC 시험 및 평가이다. 또한 최신 무선 통신 장비에 의한 영향과 PLD(전원선 교란)에 의한 효과도 이 연구에서 조사될 것이다.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제49권7호
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• pp.500-508
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• 2000

Basic design for single-phase active power filter, which aims at railway application provided with PWM-controlled converters, is comprehensively studied and its performance is presented in this paper. Active power filters are used to compensate railway signaling and public telecommunication interference due to the high-order harmonic currents generated in railway traction locomotives. A type of hybrid digital filter which is composed of low pass filter and high pass filter is proposed so that the desired harmonic reference current with accurate magnitude and phase shift can be extracted from catenary line current. A design criteria to determine input inductor L and output capacitor C is also described, considering voltage, current, PWM pattern, and switching frequency of the main converters. Finally, computer simulation and DSP-based experiments resulted from laboratory test are presented.