• Title/Summary/Keyword: connected component analysis

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A Maintenance Design of Connected-(r, s)-out-of-(m, n) F System Using Simulated Annealing (시뮬레이티드 어닐링을 이용한(m, n)중 연속(r,s) : F 시스템의 정비모형)

  • Lee, Sangheon;Kang, Youngtai;Shin, Dongyeul
    • Journal of Korean Institute of Industrial Engineers
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    • v.34 no.1
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    • pp.98-107
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    • 2008
  • The purpose of this paper is to present an optimization scheme that aims at minimizing the expected cost per unittime. This study considers a linear connected-(r, s)-ouI-of-(m, n):f lattice system whose components are orderedlike the elements of a linear (m, n)-matrix. We assume that all components are in the state 1 (operating) or 0(failed) and identical and s-independent. The system fails whenever at least one connected (r, s)-submatrix offailed components occurs. To find the optimal threshold of maintenance intervention, we use a simulatedannealing(SA) algorithm for the cost optimization procedure. The expected cost per unit time is obtained byMonte Carlo simulation. We also has made sensitivity analysis to the different cost parameters. In this study,utility maintenance model is constructed so that minimize the expense under full equipment policy throughcomparison for the full equipment policy and preventive maintenance policy. The full equipment cycle and unitcost rate are acquired by simulated annealing algorithm. The SA algorithm is appeared to converge fast inmulti-component system that is suitable to optimization decision problem.

A Study on Performance Analysis of 3kW Grid-Connected PV Systems (3kW급 계통연계형 태양광발전시스템의 성능특성 비교분석에 관한 연구)

  • So, Jung-Hun;Choi, Ju-Yeop;Yu, Gwon-Jong;Jung, Young-Seok;Choi, Jae-Ho
    • Journal of the Korean Solar Energy Society
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    • v.24 no.2
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    • pp.9-15
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    • 2004
  • 3kW grid connected PV(photovoltaic) systems have been constructed for evaluating and analyzing performance of PV system at FDTC(field demonstration test center) in Korea, PV systems installed in FDTC have been operating and monitored since November 2002. As climatic and irradiation conditions have been varied through long-term field test, data acquisition system has been constructed for measuring performance of PV system to observe the overall effect of environmental conditions on their operation characteristics. The performance of PV systems has been evaluated and analyzed for component perspective(PV array and power conditioning system) and global perspective(system efficiency, capacity factor, and electrical power energy) by field test. By the results, it is very important to develop optimal design technology of grid connected PV system.

Electromechanical Modeling and Analysis of a Multimodal Piezoelectric Energy Harvester Comprising Three Connected Beams (연결된 세 보 구조를 갖는 다모드 압전 에너지 하베스터의 전기-역학적 모델링 및 해석)

  • Jeong, Sin-Woo;Yoo, Hong Hee
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.26 no.4
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    • pp.458-468
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    • 2016
  • Electromechanical model for analyzing a multimodal piezoelectric energy harvester comprising three connected beams is presented in this paper. This system consists of three beams which are connected alternately. The piezoelectric layer is only attached to the middle beam. With this special structural configuration, the first, second, and third natural frequencies are congregated so that the energy harvester can generate meaningful amount of power consistently when the main frequency component of the excitation varies around the lowest three natural frequencies of the harvester. To investigate the dynamic and electric response of the piezoelectric energy harvester, an electromechanical model is developed using the Kane's method and the accuracy of the model is validated by comparing the results obtained with the model with those obtained with the commercial software ANSYS. The results show that the piezoelectric energy harvester comprising three connected beams has much broader power generating frequency range than that of the conventional piezoelectric energy harvester.

Current Limit Strategy of Voltage Controller of Delta-Connected H-Bridge STATCOM under Unbalanced Voltage Drop

  • Son, Gum Tae;Park, Jung-Wook
    • Journal of Electrical Engineering and Technology
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    • v.13 no.2
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    • pp.550-558
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    • 2018
  • This paper presents the current limit strategy of voltage controller of delta-connected H-bridge static synchronous compensator (STATCOM) under an unbalanced voltage fault event. When phase to ground fault happens, the feasibility to heighten the magnitude of sagging phase voltage is considered by using symmetric transformation method in delta-structure STATCOM. And the efficiency to cover the maximum physical current limit of switching device is considered by using vector analysis method that calculate the zero sequence current for balancing the cluster energy in delta connected H-bridge STATCOM. The result is simple and obvious. Only positive sequence current has to be used to support the unbalanced voltage sag. Although the relationship between combination of the negative sequence voltage with current and zero sequence current is nonlinear, the more negative sequence current is supplying, the larger zero sequence current is required. From the full-model STATCOM system simulation, zero sequence current demand is identified according to a ratio of positive and negative sequence compensating current. When only positive sequence current support voltage sag, the least zero sequence current is needed.

Real-Time Object Segmentation in Image Sequences (연속 영상 기반 실시간 객체 분할)

  • Kang, Eui-Seon;Yoo, Seung-Hun
    • The KIPS Transactions:PartB
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    • v.18B no.4
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    • pp.173-180
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    • 2011
  • This paper shows an approach for real-time object segmentation on GPU (Graphics Processing Unit) using CUDA (Compute Unified Device Architecture). Recently, many applications that is monitoring system, motion analysis, object tracking or etc require real-time processing. It is not suitable for object segmentation to procedure real-time in CPU. NVIDIA provide CUDA platform for Parallel Processing for General Computation to upgrade limit of Hardware Graphic. In this paper, we use adaptive Gaussian Mixture Background Modeling in the step of object extraction and CCL(Connected Component Labeling) for classification. The speed of GPU and CPU is compared and evaluated with implementation in Core2 Quad processor with 2.4GHz.The GPU version achieved a speedup of 3x-4x over the CPU version.

THD Analysis of Output Current for Active Frequency Drift Method in Anti-islanding (능동적 주파수 변환기법의 출력전류 고조파 왜형율 분석)

  • Lee, Ki-Ok;Choi, Ju-Yeop;Choy, Ick;Yu, Gwon-Jong;An, Jin-Ung
    • Journal of the Korean Solar Energy Society
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    • v.30 no.1
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    • pp.7-12
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    • 2010
  • As many grid-connected photovoltaic power conditioning systems (PVPCS)are installed in many residential areas simultaneously, these have raised potential problems of network protection on electrical power system. One of the numerous problems is an Islanding phenomenon. In this paper, active frequency drift (AFD) method, one of the anti-islanding methods which is analyzed by current magnitude compensation and calculation of the fundamental component. Both harmonic component and RMS value of the output current for THD analysis are provided and verified by simulation.

A Study on the PCA base Face Authentication System for Untact Work (비대면(Untact) 업무를 위한 화상인식 PCA 사용자 인증 시스템 연구)

  • Park, jongsoon;Park, chankil
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.16 no.4
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    • pp.67-74
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    • 2020
  • As the information age develops, Online education and Non-face-to-face work are becoming common. Telecommuting such as tele-education and video conferencing through the application of information technology is also becoming common due to the COVID-19. Unexpected information leakage can occur online when the company conducts work remotely or holds meetings. A system to authenticate users is needed to reduce information leakage. In this study, there are various ways to authenticate remote access users. By applying burn authentication using a biometric system, a method to identify users is proposed. The method used in the study was studied the main component analysis method, which recognizes several characteristics in facial recognition and processes interrelationships. It proposed a method that can be easily utilized without additional devices by utilizing a camera connected to a computer by authenticating the user using the shape and characteristics of the face by using the PCA method.

Design of Six-Component F/T Sensor with Flexible Fixed Ends (유연한 고정단을 가진 6축 F/T 센서의 설계)

  • Lee, Bong-Hee;Joo, Jin-Won
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.34 no.6
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    • pp.771-780
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    • 2010
  • This paper describes the design process of a six-component force/torque (F/T) sensor. The new six-component F/T sensor having leaf spring ends has been developed using a cross beam structure as the basic sensing element. Fundamental strain analysis of both ends fixed beam having a leaf spring structure is performed by finite element analysis. In order to obtain similar output sensing strains from the six component loads and minimize coupling strains, the optimal location of strain gages is determined and the strain gages are connected so that the bridge circuits with four strain gages would be balanced. Using leaf spring ends instead of rigid fixed ends, remarkable increment in output sensing strain can be achieved for two component forces. Several modifications in design result in a similar sensing strain of approximately $400\;{\mu}m/m$ for the six-component forces and moments, and a reduced coupling strain of $0\;{\mu}m/m$ between the forces and moments.

Automatic Title Detection by Spatial Feature and Projection Profile for Document Images (공간 정보와 투영 프로파일을 이용한 문서 영상에서의 타이틀 영역 추출)

  • Park, Hyo-Jin;Kim, Bo-Ram;Kim, Wook-Hyun
    • Journal of the Institute of Convergence Signal Processing
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    • v.11 no.3
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    • pp.209-214
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    • 2010
  • This paper proposes an algorithm of segmentation and title detection for document image. The automated title detection method that we have developed is composed of two phases, segmentation and title area detection. In the first phase, we extract and segment the document image. To perform this operation, the binary map is segmented by combination of morphological operation and CCA(connected component algorithm). The first phase provides segmented regions that would be detected as title area for the second stage. Candidate title areas are detected using geometric information, then we can extract the title region that is performed by removing non-title regions. After classification step that removes non-text regions, projection is performed to detect a title region. From the fact that usually the largest font is used for the title in the document, horizontal projection is performed within text areas. In this paper, we proposed a method of segmentation and title detection for various forms of document images using geometric features and projection profile analysis. The proposed system is expected to have various applications, such as document title recognition, multimedia data searching, real-time image processing and so on.

Laser-induced Damage to Polysilicon Microbridge Component

  • Zhou, Bing;He, Xuan;Li, Bingxuan;Liu, Hexiong;Peng, Kaifei
    • Current Optics and Photonics
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    • v.3 no.6
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    • pp.502-509
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    • 2019
  • Based on the typical pixel structure and parameters of a polysilicon uncooled bolometer, the absorption rate of a polysilicon microbridge infrared detector for 10.6 ㎛ laser energy was calculated through the optical admittance method, and the thermal coupling model of a polysilicon microbridge component irradiated by far infrared laser was established based on theoretical formulas. Then a numerical simulation study was carried out by means of finite element analysis for the actual working environment. It was found that the maximum temperature and maximum stress of the microbridge component are approximately exponentially changing with the laser power of the irradiation respectively and that they increase monotonically. The highest temperature zone of the model is gradually spread by the two corners of the bridge surface that are not connected to the bridge legs, and the maximum stress acts on both sides of the junction of the microbridge legs and the substrate. The mechanism of laser-induced hard damage to polysilicon detectors is the melting damage caused by high temperature. This paper lays the foundation for the subsequent study of the interference mechanism of the laser on working state polysilicon detectors.