• Title/Summary/Keyword: $A^*$ search algorithm

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An Efficient Algorithm for Mining Interactive Communication Sequence Patterns (대화형 통신 순서열 패턴의 마이닝을 위한 효율적인 알고리즘)

  • Haam, Deok-Min;Song, Ji-Hwan;Kim, Myoung-Ho
    • Journal of KIISE:Databases
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    • v.36 no.3
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    • pp.169-179
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    • 2009
  • Communication log data consist of communication events such as sending and receiving e-mail or instance message and visiting web sites, etc. Many countries including USA and EU enforce the retention of these data on the communication service providers for the purpose of investigating or detecting criminals through the Internet. Because size of the retained data is very large, the efficient method for extracting valuable information from the data is needed for Law Enforcement Authorities to use the retained data. This paper defines the Interactive Communication Sequence Patterns(ICSPs) that is the important information when each communication event in communication log data consists of sender, receiver, and timestamp of this event. We also define a Mining(FDICSP) problem to discover such patterns and propose a method called Fast Discovering Interactive Communication Sequence Pattern(FDICSP) to solve this problem. FDICSP focuses on the characteristics of ICS to reduce the search space when it finds longer sequences by using shorter sequences. Thus, FDICSP can find Interactive Communication Sequence Patterns efficiently.

Design and Implementation of a UDDI Service Middleware based on the ebXML Registry (ebXML레지스트리 기반의 UDDI 서비스 미들웨어 설계 및 구현)

  • 박재홍;김상균;이규철;김경일;김록원;송병열;조현규
    • Journal of KIISE:Databases
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    • v.31 no.3
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    • pp.307-319
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    • 2004
  • Recently, ebXML and Web Services are emerging as the XML-based electronic business frameworks. To provide a set of registry services which users or applications can store and search the business information, ebXML and Web Services use ebXML registry and UDDI registry, respectively. They use the different registries each other, but there are something that similiar to the structure and functions of both of registries. In this paper, we analyze the similarity of ebXML Registry Information Model(RIM) and UDDI data structure, and construct the mapping information. So, we design and implement the UDDI Service Middleware which translates the request of UDDI registry service into the request of ebXML registry service using the algorithm. Consequently, we could use the ebXML registry like ebXML registry as well as UDDI registry without any changes in the ebXML registry itself so that we can not need to have both of registries for e-business.

Improved Star Topology Aggregation using Line Segment (라인 세그먼트를 이용한 향상된 Star Topology Aggregation)

  • Kim, Nam-Hee
    • The KIPS Transactions:PartC
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    • v.11C no.5
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    • pp.645-652
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    • 2004
  • In this paper, we aggregate multi-links information between boundary nodes using the line segment scheme that aggregates topology in-formation within PG referring bandwidth and delay parameter. The proposed scheme can search multi-links efficiently using the depth priority method based on hop count instead of searching all links. To do this, we propose a modified line segment algorithm using two line segment method that represents two points which consist of delay-bandwidth pair to reduce topology information and provide a flexibility to the multi pie-links aggregation. And we apply it to current star topology aggregation. To evaluate performance of the proposed scheme, we compare/analyze the current method with the proposed scheme with respect to call success rate, access time and crankback rate. Through the simulation result analysis, the proposed star topology aggregation scheme presents the better performance than existing scheme.

FPGA Implementation and Performance Analysis of High Speed Architecture for RC4 Stream Cipher Algorithm (RC4 스트림 암호 알고리즘을 위한 고속 연산 구조의 FPGA 구현 및 성능 분석)

  • 최병윤;이종형;조현숙
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.14 no.4
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    • pp.123-134
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    • 2004
  • In this paper a high speed architecture of the RC4 stream cipher is proposed and its FPGA implementation is presented. Compared to the conventional RC4 designs which have long initialization operation or use double or triple S-arrays to reduce latency delay due to S-array initialization phase, the proposed architecture for RC4 stream cipher eliminates the S-array initialization operation using 256-bit valid entry scheme and supports 40/128-bit key lengths with efficient modular arithmetic hardware. The proposed RC4 stream cipher is implemented using Xilinx XCV1000E-6H240C FPGA device. The designed RC4 stream cipher has about a throughput of 106 Mbits/sec at 40 MHz clock and thus can be applicable to WEP processor and RC4 key search processor.

Information Technologies of Accounting and Analysis in Modern Companies

  • Yaremenko, Liudmyla;Hevchuk, Anna;Vuzh, Tetiana;Vashchilina, Elena;Yermolaieva, Maryna
    • International Journal of Computer Science & Network Security
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    • v.21 no.5
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    • pp.151-159
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    • 2021
  • This article addresses the issue of finding optimal solutions using the information technologies of accounting and analysis in modern companies. The aim of the study is to reveal available information technologies for the needs of small, medium and large businesses operating in modern conditions. This goal is achieved by using systematization, comparison, and analysis of information, obtained under the survey and open management statistics. For the first time, the paper systematizes up-to-date information of 2021 about the most popular programs, online services, platforms and cloud services that are used to improve accounting and analytical processes in enterprises of various sizes. The main global trends in software development in terms of COVID-19 pandemic have been identified. In particular, the study defines the countries that occupy the leading positions in the informatization of business processes. An attempt was made to classify information technologies by their use by various volume of businesses. The analysis of research results of the Internet search query frequency regarding the use of information technologies enabled to determine the most popular software products worldwide. The peculiarities of information technologies, their advantages and disadvantages were examined and the common and distinctive features were compared. It was determined that for the new enterprises to implement information technologies, it is necessary to conduct a step-by-step study of all available software products. The software evaluation algorithm was described to help select the optimal software for the specific business processes. The paper also describes the way to solve the problem of using accounting and analysis software for the businesses of a specific kind of activity.

Applications to Recommend Moving Route by Schedule Using the Route Search System of Map API (지도 API의 경로 탐색 시스템을 활용한 일정 별 동선 추천 애플리케이션)

  • Ji-Woo Kim;Jung-Yi Kim
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.23 no.2
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    • pp.1-6
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    • 2023
  • The purpose of this study is to research and develop so that users who are gradually progressing in the popularization of smartphones and the calculation of agricultural quality can use more active and flexible applications than existing application fields. People use event management applications to remember what they need to do, and maps applications to get to their appointments on time. You will need to build a glue-delivered application that leverages the Maps API to be able to recommend the glove's path for events so that the user can use the application temporarily. By comparing and analyzing currently used calendar, map, and schedule applications, several Open Maps APIs were compared to supplement the weaknesses and develop applications that converge the strengths. The results of application development by applying the optimal algorithm for recommending traffic routes according to time and place for the schedule registered by the user are described.

Reaction coefficient assessment and rechlorination optimization for chlorine residual equalization in water distribution networks (상수도 잔류염소농도 균등화를 위한 반응계수 추정 및 염소 재투입 최적화)

  • Jeong, Gimoon;Kang, Doosun;Hwang, Taemun
    • Journal of Korea Water Resources Association
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    • v.55 no.spc1
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    • pp.1197-1210
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    • 2022
  • Recently, users' complaints on drinking water quality are increasing according to emerging interest in the drinking water service issues such as pipe aging and various water quality accidents. In the case of drinking water quality complaints, not only the water pollution but also the inconvenience on the chlorine residual for disinfection are included, thus various efforts, such as rechlorination treatment, are being attempted in order to keep the chlorine concentration supplied evenly. In this research, for a more accurate water quality simulation of water distribution network, the water quality reaction coefficients were estimated, and an optimization method of chlorination/ rechlorination scheduling was proposed consideirng satisfaction of water quality standards and chlorine residual equalization. The proposed method was applied to a large-scale real water network, and various chlorination schemes were comparatively analyzed through the grid search algorithm and optimized based on the suitability and uniformity of supplied chlorine residual concentration.

Load-Balancing and Fairness Support Mechanisms in Mobile Ad Hoc Networks (이동 애드혹 네트워크에서의 부하 균등화 및 공평성 지원 방법)

  • Ahn Sanghyun;Yoo Younghwan;Lim Yujin
    • The KIPS Transactions:PartC
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    • v.11C no.7 s.96
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    • pp.889-894
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    • 2004
  • Most ad-hoc routing protocols such as AODV(Ad Hoc On-Demand Distance Vector) and DSR(Dynamic Source Routing) do not try to search for new routes if the network topology does not change. Hence, with low node mobility, traffic may be concentrated on several nodes, which results in long end-to-end delay due to congestion at the nodes. Furthermore, since some specific nodes are continuously used for long duration, their battery power may be rapidly exhausted. Expiration of nodes causes connections traversing the nodes to be disrupted and makes many routing requests be generated at the same time. Therefore, we propose a load balancing approach called Simple Load-balancing Approach (SLA), which resolves the traffic concentration problem by allowing each node to drop RREQ (Route Request Packet) or to give up packet forwarding depending on its own traffic load. Meanwhile, mobile nodes nay deliberately give up forwarding packets to save their own energy. To make nodes volunteer in packet forwarding. we also suggest a payment scheme called Protocol-Independent Fairness Algorithm (PIEA) for packet forwarding. To evaluate the performance of SLA, we compare two cases where AODV employs SLA or not. Simulation results show that SLA can distribute traffic load well and improve performance of entire ad-hoc networks.

Beacon Geolocation Scheme of COSPAS-SARSAT System for Heavy Disaster Environment (다중 재난 상황에 적합한 COSPAS-SARSAT 탐색구조 비컨 위치추정 기법)

  • Kim, Jaehyun;Lee, Sanguk;Sin, Cheonsig;Ahn, Woo-Geun
    • Journal of Satellite, Information and Communications
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    • v.10 no.4
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    • pp.146-150
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    • 2015
  • The COSPAS-SARSAT committee decides MEOSAR (Medium-Earth Orbit for search and rescue) service development for installing 406MHz SAR instruments on their respective MEO navigation satellite system of the United States, EU, and Russia, since 2000. The transmitted beacon signal is separately arrived by satellites with different FOA (Frequency of Arrival) and TOA (Time of Arrival). It is directly transferred to MEOLUT. In MEOLUT, a LUT track at least 3 or 4 satellites simultaneously and estimate location of beacon using time difference of arrival (TDOA) and frequency difference arrival (FDOA). But the transmitted distress signals may be overlapped each other because the distress beacons transmit signal on mean interval of 50 seconds in arbitrary time. It's difficult that simultaneously estimate location of beacon by current scheme for several overlapped distress signal. So we use cross ambiguity function (CAF) Map algorithm and present Multi-CAF MAP scheme in order to satisfy performance requirement of system. The performance is analyzed for COSAPS-SARSAT MEOSAR.

Parallel Computation of a Nonlinear Structural Problem using Parallel Multifrontal Solver (다중 프런트 해법을 이용한 비선형 구조문제의 병렬계산)

  • Jeong, Sun Wan;Kim, Seung Jo
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.31 no.2
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    • pp.41-50
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    • 2003
  • In this paper, nonlinear parallel structural analyses are introduced by using the parallel multifrontal solver and damage localization for 2D and 3D crack models is presented as the application of nonlinear parallel computation. The parallel algorithms related with nonliear reduce the amount of memory used is carried out because many variables should be utilized for this highly nonlinear damage analysis. Also, Riks' continuation method is parallelized to search the solution when strain softening occurs due to damage evolution. For damage localization problem, several computational models having up to around 1-million degree of freedoms are used. The parallel performance in this nonlinear parallel algorithm is shown through these examples and the local variation of damage at crack tip is compared among the models with different degree of freedoms.