• 제목/요약/키워드: expansion algorithm

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Butterfly key expansion 알고리즘을 적용한 ECQV에 관한 연구 (A study on ECQV applied the butterfly key expansion algorithm)

  • 선설희;김은기
    • 한국정보통신학회:학술대회논문집
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    • 한국정보통신학회 2016년도 추계학술대회
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    • pp.762-764
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    • 2016
  • ECQV(Elliptic Curve Qu-Vanstone)는 ECC(Elliptic Curve Cryptography) 기반의 묵시적 인증서(implicit certificate)를 생성하는 방법으로서 기존에 사용되던 명시적 인증서에 비해 크기가 작고 빠르기 때문에 메모리가 충분하지 않거나 대역폭이 작은 제한된 통신환경에서 유용하게 사용 될 수 있다. 또한, Butterfly key expansion 알고리즘은 하나의 공개키를 사용하여 여러 개의 인증서를 발급할 수 있도록 지원하는 방법이다. 본 연구에서는 기존 ECQV에 Butterfly key expansion 알고리즘을 적용하여, 추후 자동차 통신 환경에서 유용하게 사용될 수 있는 인증서 발급 방법을 제안한다.

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다입력변수를 사용한 멀티형 공조시스템 압축기와 전자팽창밸브의 퍼지 제어 알고리즘 (Fuzzy Control Algorithms for the Compressor and the Electronic Expansion Valve of a Multi-type Air-conditioning System using Multiple Input Variables)

  • 한도영;박관준
    • 설비공학논문집
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    • 제18권2호
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    • pp.163-171
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    • 2006
  • In order to control multi-zone temperatures, a multi-type air-conditioning system may be used. In this study, control algorithms for the compressor and the electronic expansion valve of a multi-type air-conditioning system were developed by using fuzzy logics. The compressor control algorithm was composed of a compressor pressure setpoint algorithm, a compressor pressure setpoint reset algorithm, and a compressor frequency setpoint algorithm. The electronic expansion valve control algorithm was composed of an indoor temperature control algorithm, and a superheat control algorithm. These algorithms were applied to a multi-type air-conditioning system. Test showed good results for the control of a multi-type air-conditioning system.

B-spline 곡선을 power 기저형태의 구간별 다항식으로 바꾸는 Direct Expansion 알고리듬 (A Direct Expansion Algorithm for Transforming B-spline Curve into a Piecewise Polynomial Curve in a Power Form.)

  • 김덕수;류중현;이현찬;신하용;장태범
    • 한국CDE학회논문집
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    • 제5권3호
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    • pp.276-284
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    • 2000
  • Usual practice of the transformation of a B-spline curve into a set of piecewise polynomial curves in a power form is done by either a knot refinement followed by basis conversions or applying a Taylor expansion on the B-spline curve for each knot span. Presented in this paper is a new algorithm, called a direct expansion algorithm, for the problem. The algorithm first locates the coefficients of all the linear terms that make up the basis functions in a knot span, and then the algorithm directly obtains the power form representation of basis functions by expanding the summation of products of appropriate linear terms. Then, a polynomial segment of a knot span can be easily obtained by the summation of products of the basis functions within the knot span with corresponding control points. Repeating this operation for each knot span, all of the polynomials of the B-spline curve can be transformed into a power form. The algorithm has been applied to both static and dynamic curves. It turns out that the proposed algorithm outperforms the existing algorithms for the conversion for both types of curves. Especially, the proposed algorithm shows significantly fast performance for the dynamic curves.

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A Modified Expansion-Contraction Method for Mobile Object Tracking in Video Surveillance: Indoor Environment

  • Kang, Jin-Shig
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • 제13권4호
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    • pp.298-306
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    • 2013
  • Recent years have witnessed a growing interest in the fields of video surveillance and mobile object tracking. This paper proposes a mobile object tracking algorithm. First, several parameters such as object window, object area, and expansion-contraction (E-C) parameter are defined. Then, a modified E-C algorithm for multiple-object tracking is presented. The proposed algorithm tracks moving objects by expansion and contraction of the object window. In addition, it includes methods for updating the background image and avoiding occlusion of the target image. The validity of the proposed algorithm is verified experimentally. For example, the first scenario traces the path of two people walking in opposite directions in a hallway, whereas the second one is conducted to track three people in a group of four walkers.

Software Key Node Recognition Algorithm for Defect Detection based on Node Expansion Degree and Improved K-shell Position

  • Wanchang Jiang;Zhipeng Liu
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제18권7호
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    • pp.1817-1839
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    • 2024
  • To solve the problem of insufficient recognition of key nodes in the existing software defect detection process, this paper proposes a key node recognition algorithm based on node expansion degree and improved K-shell position, shortened as SDD_KNR. Firstly, the calculation formula of node expansion degree is designed to improve the degree that can measure the local defect propagation capability of nodes in the software network. Secondly, the concept of improved K-shell position of node is proposed to obtain the improved K-shell position of each node. Finally, the measurement of node defect propagation capability is defined, and the key node recognition algorithm is designed to identify the key function nodes with large defect impact range in the process of software defect detection. Using real software systems such as Nano, Cflow and Tar to design three sets of experiments. The corresponding directed weighted software function invoke networks are built to simulate intentional attack and defect source infection. The proposed SDD_KNR algorithm is compared with the BC algorithm, K-shell algorithm, KNMWSG algorithm and NMNC algorithm. The changing trend of network efficiency and the strength of node propagation force are analyzed to verify the effectiveness of the proposed SDD_KNR algorithm.

텐덤형 냉방시스템의 안전운전을 고려한 압축기와 전자팽창밸브 제어 (Control of Compressors and Electronic Expansion Valve considering the Safe Operation of a Tandem-type Air-conditioning system)

  • 한도영;김재현
    • 대한설비공학회:학술대회논문집
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    • 대한설비공학회 2006년도 하계학술발표대회 논문집
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    • pp.675-680
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    • 2006
  • Capacities of a tandem-type air-conditioner may be modulated by turning on and off of multiple compressors, and adjusting the position of a electronic expansion valve. In this study, control algorithms for compressors and a electronic expansion valve were developed by using fuzzy logics. The pressure control algorithm was also developed for the safe operation of compressors. There algorithms were implemented in a test lab and proved to be effective for the control of indoor air temperature and superheat temperature,

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진화 프로그래밍의 전원개발계획에의 적용 연구 (Application to Generation Expansion Planning of Evolutionary Programming)

  • 원종률
    • 대한전기학회논문지:전력기술부문A
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    • 제50권4호
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    • pp.180-187
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    • 2001
  • This paper proposes an efficient evolutionary programming algorithm for solving a generation expansion planning(GEP) problem known as a highly-nonlinear dynamic problem. Evolutionary programming(EP) is an optimization algorithm based on the simulated evolution (mutation, competition and selection). In this paper, new algorithm is presented to enhance the efficiency of the EP algorithm for solving the GEP problem. By a domain mapping procedure, yearly cumulative capacity vectors are transformed into one dummy vector, whose change can yield a kind of trend in the cost value. To validate the proposed approach, this algorithm is tested on two cases of expansion planning problems. Simulation results show that the proposed algorithm can provide successful results within a resonable computational time compared with conventional EP and dynamic programming.

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A vision-based system for inspection of expansion joints in concrete pavement

  • Jung Hee Lee ;bragimov Eldor ;Heungbae Gil ;Jong-Jae Lee
    • Smart Structures and Systems
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    • 제32권5호
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    • pp.309-318
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    • 2023
  • The appropriate maintenance of highway roads is critical for the safe operation of road networks and conserves maintenance costs. Multiple methods have been developed to investigate the surface of roads for various types of cracks and potholes, among other damage. Like road surface damage, the condition of expansion joints in concrete pavement is important to avoid unexpected hazardous situations. Thus, in this study, a new system is proposed for autonomous expansion joint monitoring using a vision-based system. The system consists of the following three key parts: (1) a camera-mounted vehicle, (2) indication marks on the expansion joints, and (3) a deep learning-based automatic evaluation algorithm. With paired marks indicating the expansion joints in a concrete pavement, they can be automatically detected. An inspection vehicle is equipped with an action camera that acquires images of the expansion joints in the road. You Only Look Once (YOLO) automatically detects the expansion joints with indication marks, which has a performance accuracy of 95%. The width of the detected expansion joint is calculated using an image processing algorithm. Based on the calculated width, the expansion joint is classified into the following two types: normal and dangerous. The obtained results demonstrate that the proposed system is very efficient in terms of speed and accuracy.

삼차원 구의 보로노이 다이어그램 계산을 위한 두 가지 알고리듬 및 단백질구조채석에의 응용 (Two Algorithms for Constructing the Voronoi Diagram for 3D Spheres and Applications to Protein Structure Analysis)

  • 김동욱;조영송;김덕수
    • 한국CDE학회논문집
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    • 제11권2호
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    • pp.97-106
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    • 2006
  • Voronoi diagrams have been known for numerous important applications in science and engineering including CAD/CAM. Especially, the Voronoi diagram for 3D spheres has been known as very useful tool to analyze spatial structural properties of molecules or materials modeled by a set of spherical atoms. In this paper, we present two algorithms, the edge-tracing algorithm and the region-expansion algorithm, for constructing the Voronoi diagram of 3D spheres and applications to protein structure analysis. The basic scheme of the edge-tracing algorithm is to follow Voronoi edges until the construction is completed in O(mn) time in the worst-case, where m and n are the numbers of edges and spheres, respectively. On the other hand, the region-expansion algorithm constructs the desired Voronoi diagram by expanding Voronoi regions for one sphere after another via a series of topology operations, starting from the ordinary Voronoi diagram for the centers of spheres. It turns out that the region-expansion algorithm also has the worst-case time complexity of O(mn). The Voronoi diagram for 3D spheres can play key roles in various analyses of protein structures such as the pocket recognition, molecular surface construction, and protein-protein interaction interface construction.

Integrated Generation and Transmission Expansion Planning Using Generalized Bender’s Decomposition Method

  • Kim, Hyoungtae;Lee, Sungwoo;Kim, Wook
    • Journal of Electrical Engineering and Technology
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    • 제10권6호
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    • pp.2228-2239
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    • 2015
  • A novel integrated optimization method based on the Generalized Bender’s Decomposition (GBD) is proposed to combine both generation and transmission expansion problems. Most of existing researches on the integrated expansion planning based on the GBD theory incorporate DC power flow model to guarantee the convergence and improve the computation time. Inherently the GBD algorithm based on DC power flow model cannot consider variables and constraints related bus voltages and reactive power. In this paper, an integrated optimization method using the GBD algorithm based on a linearized AC power flow model is proposed to resolve aforementioned drawback. The proposed method has been successfully applied to Garver’s six-bus system and the IEEE 30-bus system which are frequently used power systems for transmission expansion planning studies.