• Title/Summary/Keyword: $A^{\ast}$ algorithm

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Optimizing Multiprecision Squaring for Efficient Public Key Cryptography on 8-bit Sensor Nodes (8 비트 센서 노드 상에서 효율적인 공개키 암호를 위한 다정도 제곱 연산의 최적화)

  • Kim, Il-Hee;Park, Yong-Su;Lee, Youn-Ho
    • Journal of KIISE:Computer Systems and Theory
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    • v.36 no.6
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    • pp.502-510
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    • 2009
  • Multiprecision squaring is one of the most significant algorithms in the core public key cryptography operation. The aim of this work is to present a new improved squaring algorithm compared with the MIRACL's multi precision squaring algorithm in which the previous work [1] on multiprecision multiplication is implemented. First, previous works on multiprecision multiplication and standard squaring are analyzed. Then, our new Lazy Doubling squaring algorithm is introduced. In MIRACLE library [3], Scott's Carry-Catcher Hybrid multiplication technique [1] is applied to implementation of multiprecision multiplication and squaring. Experimental results of the Carry-Catcher hybrid squaring algorithm and the proposed Lazy Doubling squaring algorithm both of which are tested on Atmega128 CPU show that proposed idea has achieved significant performance improvements. The proposed Lazy Doubling Squaring algorithm reduces addition instructions by the fact $a_0\;{\ast}\;2\;+\;a_1\;{\ast}\;2\;+\;...\;+\;a_{n-1}\;{\ast}\;2\;+\;a_n\;{\ast}\;2\;=\;(a_0\;+\;a_1\;+\;...\;+\;a_{n-1}\;+\;a_n)\;{\ast}\;2$ while the standard squaring algorithm reduces multiplication instructions by the fact $S_{ij}\;=\;x_i\;{\ast}\;x_j\;=\;S_{ij}$. Experimental results show that the proposed squaring method is 25% faster than that in MIRACL.

Optimized Trim and Heeling Adjustment by Using Heuristic Algorithm (휴리스틱 알고리즘을 이용한 트림 및 힐링 각도 조절 최적화)

  • HONG CHUNG You;LEE JIN UK;PARK JE WOONG
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • 2004.11a
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    • pp.62-67
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    • 2004
  • Many ships in voyage experience weight and buoyancy distribution change by various reasons such as change of sea water density and waves, weather condition, and consumption of fuel, provisions, etc . The weight and buoyancy distribution change can bring the ships out of allowable trim, heeling angle. In these case, the ships should adjust trim and heeling angle by shifting of liquid cargo or ballasting, deballasting of ballast tanks for recovery of initial state or for a stable voyage. But, if the adjustment is performed incorrectly, ship's safety such as longitudinal strength, intact stability, propeller immersion, wide visibility, minimum forward draft cannot be secured correctly. So it is required that the adjustment of trim and heeling angle should be planned not by human operators but by optimization computer algorithm. To make an optimized plan to adjust trim and heeling angle guaranteeing the ship's safety and quickness of process, Uk! combined mechanical analysis and optimization algorithm. The candidate algorithms for the study were heuristic algorithm, meta-heuristic algorithm and uninformed searching algorithm. These are widely used in various kinds of optimization problems. Among them, heuristic algorithm $A^\ast$ was chosen for its optimality. The $A^\ast$ algorithm is then applied for the study. Three core elements of $A^\ast$ Algorithm consists of node, operator, evaluation function were modified and redefined. And we analyzed the $A^\ast$ algorithm by considering cooperation with loading instrument installed in most ships. Finally, the algorithm has been applied to tanker ship's various conditions such as Normal Ballast Condition, Homo Design Condition, Alternate Loading Condition, Also the test results are compared and discussed to confirm the efficiency and the usefulness of the methodology developed the system.

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THE CHARACTERIZATION OF SORT SEQUENCES

  • Yun, MIn-Young
    • Journal of applied mathematics & informatics
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    • v.4 no.2
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    • pp.513-528
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    • 1997
  • A sort sequence $S_n$ is a sequence of all unordered pairs of indices in $I_n\;=\;{1,\;2,v...,\;n}$. With a sort sequence Sn we assicuate a sorting algorithm ($AS_n$) to sort input set $X\;=\;{x_1,\;x_2,\;...,\;x_n}$ as follows. An execution of the algorithm performs pairwise comparisons of elements in the input set X as defined by the sort sequence $S_n$, except that the comparisons whose outcomes can be inferred from the outcomes of the previous comparisons are not performed. Let $X(S_n)$ denote the acverage number of comparisons required by the algorithm $AS_n$ assuming all input orderings are equally likely. Let $X^{\ast}(n)\;and\;X^{\circ}(n)$ denote the minimum and maximum value respectively of $X(S_n)$ over all sort sequences $S_n$. Exact determination of $X^{\ast}(n),\;X^{\circ}(n)$ and associated extremal sort sequenes seems difficult. Here, we obtain bounds on $X^{\ast}(n)\;and\;X^{\circ}(n)$.

Forest Fire Detection and Identification Using Image Processing and SVM

  • Mahmoud, Mubarak Adam Ishag;Ren, Honge
    • Journal of Information Processing Systems
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    • v.15 no.1
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    • pp.159-168
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    • 2019
  • Accurate forest fires detection algorithms remain a challenging issue, because, some of the objects have the same features with fire, which may result in high false alarms rate. This paper presents a new video-based, image processing forest fires detection method, which consists of four stages. First, a background-subtraction algorithm is applied to detect moving regions. Secondly, candidate fire regions are determined using CIE $L{\ast}a{\ast}b{\ast}$ color space. Thirdly, special wavelet analysis is used to differentiate between actual fire and fire-like objects, because candidate regions may contain moving fire-like objects. Finally, support vector machine is used to classify the region of interest to either real fire or non-fire. The final experimental results verify that the proposed method effectively identifies the forest fires.

Design and Implementation of Game Robot based-on Network (네트워크 기반 게임 로봇의 설계 및 구현)

  • Choi, Chan-Yung;Im, Kyoung-Mi;Cho, Seok-Bong;Lim, Jae-Hyun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.11 no.7
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    • pp.2616-2622
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    • 2010
  • This paper implements the algorithm for Janggi game robot based on network for the disabled people. The movement of target on janggi for them is designed using wireless robot and voice recognition. To remove obstacles, we implement the algorithm for moving object based on $A^{\ast}$ algorithm. We test the janggi game and certify effectiveness of moving object through the implementation of algorithm for them.

Color Image Saturation enhancement algorithm using CIE $L^{\ast}U^{\ast}V^{\ast}$ color space (CIE $L^{\ast}U^{\ast}V^{\ast}$를 이용한 컬러 이미지 Saturation 향상 알고리즘)

  • Jo, Young-Sim;Cho, Hwa-Hyun;Choi, Myung-Ryul
    • Proceedings of the IEEK Conference
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    • 2005.11a
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    • pp.371-374
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    • 2005
  • A novel Color Image Saturation enhancement method to strengthen video images without producing oversaturated or color contour artifacts is proposed in this paper. Based on the luminance information, the relations between luminance levels and maximum chrominance vectors in each subcolor are generated for each pixel, so that the upper bound of the allowed saturation factor for a pixel can be derived, and much vivid video image can be achieved

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Color Transfer using Color Contrast Based Templates (색의대비 기반 템플릿을 이용한 색상 변환)

  • Park, Young-Sup;Yoon, Kyung-Hyun;Lee, Eun-Seok
    • Journal of Korea Multimedia Society
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    • v.12 no.5
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    • pp.633-643
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    • 2009
  • We propose a color transfer method that used color contrast based templates to express the visual difference clearly between objects, while remaining the quality of the input image. Our algorithm employs colors of both the input image and template distributed on the $a^{\ast}b^{\ast}$chrominance plane of CIE $L^{\ast}a^{\ast}b^{\ast}$color space. The templates are made by considering the effect of color contrast and have the shape of either a line or a curve represented color distribution of the basic colors based gradation image. These tempates can be modeled on spline curves. We also generate simply new templates with the different basic colors by moving the control points of that curve. The color transfer method using the templates is done through a regressive analysis and color matching. We maintained color coherence of the input image by transforming similarly the color distribution of an input image to the one of templates.

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Implementation and Evaluation of Path-Finding Algorithm using Abstract Graphs (추상 그래프를 활용한 경로 탐색 알고리즘의 구현 및 성능 평가)

  • Kim, Ji-Soo;Lee, Ji-wan;Cho, Dae-Soo
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2009.10a
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    • pp.245-248
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    • 2009
  • Recently, Many studies have been progressing to path-finding with dynamic information on the Terminal Based Navigation System(TBNS). However, the most of existing algorithms are based on $A{\ast}$ algorithm. Path-finding algorithms which use heuristic function may occur a problem of the increase of exploring cost in case of that there is no way determined by heuristic function or there are 2 way more which have almost same cost. In this paper, two abstract graph(AG) that are different method of construction, Homogeneous Node merging($AG^H$) and Connected Node Merging($AG^C$), are implemented. The abstract graph is a simple graph of real road network. The method of using the abstract graph is proposed for reducing dependency of heuristic and exploring cost. In result of evaluation of performance, $AG^C$ has better performance than $AG^H$ at construction cost but $AG^C$ has worse performance than $AG^H$ exploring cost.

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Performance Evaluation of Different Route Planning Algorithms in the Vehicle Navigation System (차량 항법 시스템의 경로 탐색을 위한 탐색 알고리즘들의 성능 비교)

  • Lee, Jae-Mu;Kim, Jong-Hoon;Jeon, H.-Seok
    • Journal of The Korean Association of Information Education
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    • v.2 no.2
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    • pp.252-259
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    • 1998
  • Vehicle navigation systems employ a certain route planning algorithm that provides the shortest path between the starting point and the destination point. The performance of a given route planning algorithm is measured through the degree of optimal route selection and the time cost to complete searching an optimal path. In this paper, various route planning algorithms are evaluated through computer simulation based on a real digital map database. Among those algorithms evaluated in this paper, the Modified Bi-directional A${\ast}$ algorithm is found to be the best algorithm for use in vehicle navigation systems.

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Application of $A{\ast}$ Algorithm to Two-Dimensional Cutting Problem for Producing Metal Grating (금속 그레이팅 생산을 위한 $A{\ast}$ 알고리즘의 2차원 절단 문제에의 적용)

  • Kim, Jin-Myoung;Cho, Tae-Ho
    • Proceedings of the Korea Information Processing Society Conference
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    • 2005.11a
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    • pp.449-452
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    • 2005
  • 그레이팅(grating) 생산 공정에서 절단공정은 패널(panel)을 원하는 형태의 그레이팅으로 절단하여 제품을 생산한다. 실제 절단이 이루어지기 전에 절단 계획을 생성하는데, 이것은 절단 대상이 되는 그레이팅들의 배치 방법을 결정한다. 이 계획은 제품의 생산비용의 증감에 중요한 역할을 한다. 절단 계획의 생성은 2차원 절단 문제와 유사하다. 본 논문에서는 금속 그레이팅 생산 공정의 절단 계획에 대하여 연구하고 인공지능 탐색 방법 중 하나인 $A{\ast}$ 알고리즘을 계획 생성에 적용한다. 또한 시뮬레이션을 통하여 자재의 손실을 기준으로 제안된 방법과 기존의 방법을 비교 평가 하겠다.

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