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A New Scheme for Maintaining Balanced DC Voltages in Static Var Compensator(SVC) Using Cascade Multilevel Inverter

  • Min, Wan-Ki;Min, Joon-Ki;Choi, Jae-Ho
    • Proceedings of the KIPE Conference
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    • 2001.10a
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    • pp.561-565
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    • 2001
  • This paper proposes a new switching scheme of a static var compensator(SVC) with cascade multilevel inverter which employs H-bridge inverter(HBI). To improve the un­balanced problem of the DC capacitor voltages, the rotated switching scheme of fundamental frequency is newly used. The optimized fundamental switching pattern with low switching frequency is adapted to be suitable for high application. The selective harmonic elimination method(SHEM) allows to keep the total harmonic distortion(THD) low in the output voltage of multilevel inverter. The SVC system is modeled using the d-q transform which calculates the instantaneous reactive power. This model is used to design a controller and analyze the SVC system. Simulated and experimental results are also presented and discussed to validate the proposed schemes.

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Model-based 3-D object recognition using hopfield neural network (Hopfield 신경회로망을 이용한 모델 기반형 3차원 물체 인식)

  • 정우상;송호근;김태은;최종수
    • Journal of the Korean Institute of Telematics and Electronics B
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    • v.33B no.5
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    • pp.60-72
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    • 1996
  • In this paper, a enw model-base three-dimensional (3-D) object recognition mehtod using hopfield network is proposed. To minimize deformation of feature values on 3-D rotation, we select 3-D shape features and 3-D relational features which have rotational invariant characteristics. Then these feature values are normalized to have scale invariant characteristics, also. The input features are matched with model features by optimization process of hopjfield network in the form of two dimensional arrayed neurons. Experimental results on object classification and object matching with the 3-D rotated, scale changed, an dpartial oculued objects show good performance of proposed method.

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Surface Segmentation and Feature Description using the Signature Technique (Signature 기법을 이용한 면의 특징 표현 및 분할 기법)

  • 이보형;한헌수
    • Journal of the Korean Institute of Telematics and Electronics S
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    • v.34S no.12
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    • pp.90-97
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    • 1997
  • This paper presents a new algorithm for surface segmentation and feature description. The algorithm extracts the signature of an edge image based on the signature technqique[12] in the first stage. If there exists a range in the angle axis where more than two signatures form a closed curve, we can conclude there is a surface inside the range. Using this feature of the signature, surfaces can be segmented. The surface features such as number of vertices, number of edges, and type of surfaces can also be extracted by finding the signatures of individual surfaces. This algorithm has distinguished advantages: it can easily recover the lost part occuring in the edge iage using the curve fitting method and it can extract surface features even when surfaces are rotated in 3-D space.

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The Effects of 3.5% NaCl Aqueous Solution Temperature on the Corrosion Fatigue Fracture of Dual phase steel (3.5% NaCl 수용액의 온도변화가 복합조직강의 부식피로파괴에 미치는 영향)

  • 오세욱;도영문;박수영;김재철;김광영
    • Journal of Ocean Engineering and Technology
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    • v.6 no.1
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    • pp.140-147
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    • 1992
  • Corrsion fatigue test was performed under rotated bending in 3.5% NaCl aqueous solution having a temperature from 278.deg.K in order to investigate the effects of aqueous solution remperature on the corrosion fatigue fracture of raw material steel(SS41) and dual phase steel that was produced from SS41 by a series of heat treatment. Corrosion fatigue life decreases remarkably with increase in solution temperature or with decrease in stress level. The corrosion fatigue life and the crack propagation rate at 303.deg.K show the similar behaviors with those at 318.deg.K, which is assumed to be caused by concentration polarization phenamena. The number and the lengths of microcracks increase with increase in solution temperature, so they lead to the decrease in corrosion fatigue life.

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The Actual Conditions and the Demands of Services about the Welfare of the Elderly people in Iksan city (익산시 노인의 복지서비스 이용실태 및 요구도)

  • 홍달아기;하근영
    • Journal of the Korean Home Economics Association
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    • v.38 no.9
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    • pp.75-92
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    • 2000
  • The purpose of study was to improve the quality of the welfare service for the elderly people in Iksan city. For the purpose, this study consists of three main subjects. (1) A analysis about the socio-demographic characteristics of the elderly. (2) A analysis about the experience of the welfare services for the elderly people. (3) A analysis about the demands of services on elderly related institutions or voluntary service groups. For the data set 204 the elderly people living in Iksan city, were chosen. The data were analyzed with SPSS program were frequency, percentage, chi-square. The major findings were as follows : The 70.1% of the elderly experienced of the welfare services. The most of the elderly people experienced of the elderly rotated institutions or voluntary service groups did not satisfy about services. The elderly people hoped to get the services about health, tour, education.

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Face detection using haar-like feature and Tracking with Lucas-Kanade feature tracker (Haar-like feature를 이용한 얼굴 검출과 추적을 위한 Lucas-Kanade특징 추적)

  • Kim, Ki-Sang;Kim, Se-Hoon;Park, Gene-Yong;Choi, Hyung-Il
    • 한국HCI학회:학술대회논문집
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    • 2008.02a
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    • pp.835-838
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    • 2008
  • In this paper, we present automatic face detection and tracking which is robustness in rotation and translation. Detecting a face image, we used Haar-like feature, which is fast detect facial image. Also tracking, we applied Lucas-Kanade feature tracker and KLT algorithm, which has robustness for rotated facial image. In experiment result, we confirmed that face detection and tracking which is robustness in rotation and translation.

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Performance Evaluation of the Velocity Profile Integration for the Multi-Path Ultrasonic Flowmeter in Symmetric & Asymmetric Flow Field (대칭 및 비대칭 유동장에서 다회선 초음파 유량계의 유속분포 적분 방법 평가)

  • Kim, Joo-Young;Kim, Kyung-Jin;Park, Sung-Ha
    • 유체기계공업학회:학술대회논문집
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    • 2002.12a
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    • pp.370-377
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    • 2002
  • Generally, the system of calculation for the multi-path ultrasonic flow meters can be divided into two methods by how to get the mean velocity, namely, weighting and direct method. Weighting-method derive the mean velocity through modeling in theoretical velocity profile. Direct-method derive the mean velocity though actual flow distribution. The system of calculation varies with maker's transducer configuration and integration method. Each system has merits and demerits. This paper describes the system of integration that calculates line velocity over cross-section of the circular pipe. Flow rate mr discussed in this paper is a difference between theoretical flow rate and integrated flow rate according to values of Reynolds number in symmetric flow field or theoretical flow rate and integrated flow rate according to rotated model in asymmetric flow field.

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A Study on the Development of Camera Gimbal System for Unmanned Flight Vehicle with VR 360 Degree Omnidirectional Photographing (360도 VR 촬영을 위한 무인 비행체용 카메라 짐벌 시스템 개발에 관한 연구)

  • Jung, Nyum;Kim, Sang-Hoon
    • The Journal of the Korea institute of electronic communication sciences
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    • v.11 no.8
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    • pp.767-772
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    • 2016
  • The purpose of this paper is to develop a gimbal system installed in the UFV(unmanned flight vehicles) for 360 degree VR video. In particular, even if the UFV rotated any direction the camera position is fiexd to minimize the shaking using the gyro sensor and the camera system is stable for taking $360^{\circ}$ panorama VR images.

Eye Detection in Facial Images Using Zernike Moments with SVM

  • Kim, Hyoung-Joon;Kim, Whoi-Yul
    • ETRI Journal
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    • v.30 no.2
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    • pp.335-337
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    • 2008
  • An eye detection method for facial images using Zernike moments with a support vector machine (SVM) is proposed. Eye/non-eye patterns are represented in terms of the magnitude of Zernike moments and then classified by the SVM. Due to the rotation-invariant characteristics of the magnitude of Zernike moments, the method is robust against rotation, which is demonstrated using rotated images from the ORL database. Experiments with TV drama videos showed that the proposed method achieved a 94.6% detection rate, which is a higher performance level than that achievable by the method that uses gray values with an SVM.

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The Review & study of reformative model in Korean sacrificial rite (우리나라 제례의 검토와 제례 재구성모델 연구)

  • Doo, Kyung-Ja
    • Journal of Families and Better Life
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    • v.18 no.3 s.47
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    • pp.147-170
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    • 2000
  • The purpose of this study is to review Korean sacrificial rite and reform it to be fit for modern life, the research method is to review literatures such as ancient writings and various references for the sacrificial rite. The new model of Korean sacrificial rite is as follows; 1. New year's and chusok's sacrificial rite should be omitted and only the anniversary rite be left. 2. Time of anniversary rite should be convenient hour that all attendants can meet and the extent of attendants should be limited into the deads sons & daughters. 3. Subject of anniversary rite should be limited into the parents. 4. Foods and liquor offered to the dead should be omitted 5. Supervisor of sacrificial rite should be not only the eldest son but also dead's sons and daughters, so the anniversary rite should be rotated among brothers and sisters.

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