• Journal of Korean Society of Transportation
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• v.23 no.4 s.82
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• pp.81-91
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• 2005

The Traveling Salesman Problem(TSP) is one of the NP-complete (None-deterministic Polynomial time complete) route optimization problems. Its calculation time increases very rapidly as the number of nodes does. Therefore, the near optimum solution has been searched by heuristic algorithms rather than the real optimum has. This paper reviews the Ant System Algorithm(ANS), an heuristic algorithm of TSP and its applicability in the parcel delivery service in Korea. ASA, which is an heuristic algorithm of NP-complete has been studied by M. Dorigo in the early 1990. ASA finds the optimum route by the probabilistic method based on the cumulated pheromone on the links by ants. ASA has been known as one of the efficient heuristic algorithms in terms of its calculation time and result. Its applications have been expanded to vehicle routing problems, network management and highway alignment planning. The precise criteria for vehicle routing has not been set up in the parcel delivery service of Korea. Vehicle routing has been determined by the vehicle deriver himself or herself. In this paper the applicability of ASA to the parcel delivery service has been reviewed. When the driver s vehicle routing is assumed to follow the Nearest Neighbor Algorithm (NNA) with 20 nodes (pick-up and drop-off places) in $10Km{\times}10Km$ service area, his or her decision was compared with ASA's one. Also, ASA showed better results than NNA as the number of nodes increases from 10 to 200. If ASA is applied, the transport cost savings could be expected in the parcel delivery service in Korea.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.4
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• pp.833-839
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• 2007

In case of wireless sensor networks being applied to a target environment having continuous data transfer, high-speed data transmission and processing is necessary to meet increased bandwidth needs. This paper proposes a novel multipath routing algorithm to increase the bandwidth of continuous data stream for the wireless sensor network using dual channel routers. We evaluate performance of the proposed algorithm in the wireless sensor network using the dual channel touter based on ZigBee protocol. According to the experimental evaluation, the proposed algorithm showed outstanding performance enhancement with the bandwidth of 150kbps, which is about twice of existing single channel router.

• Journal of the Korean Society for information Management
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• v.40 no.4
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• pp.403-428
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• 2023

This study investigates the development path and intellectual structure of data literacy research, aiming to identify emerging topics in the field. A comprehensive search for data literacy-related articles on the Web of Science reveals that the field is primarily concentrated in Education & Educational Research and Information Science & Library Science, accounting for nearly 60% of the total. Citation network analysis, employing the PageRank algorithm, identifies key papers with high citation impact across various topics. To accurately trace the development path of data literacy research, an enhanced PageRank main path algorithm is developed, which overcomes the limitations of existing methods confined to the Education & Educational Research field. Keyword bibliographic coupling analysis is employed to unravel the intellectual structure of data literacy research. Utilizing the PNNC algorithm, the detailed structure and clusters of the derived keyword bibliographic coupling network are revealed, including two large clusters, one with two smaller clusters and the other with five smaller clusters. The growth index and mean publishing year of each keyword and cluster are measured to pinpoint emerging topics. The analysis highlights the emergence of critical data literacy for social justice in higher education amidst the ongoing pandemic and the rise of AI chatbots. The enhanced PageRank main path algorithm, developed in this study, demonstrates its effectiveness in identifying parallel research streams developing across different fields.

• Journal of KIISE:Information Networking
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• v.35 no.5
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• pp.395-401
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• 2008

In order to determine path(s) satisfied with bandwidth-guaranteed in the Internet, routers should have information on network topology and link state. The information is stored in Link State Database (LSDB) located in each router and managed. If link states information is changed, routers inform their neighbor of link state information changed by sending Link State Update (LSU) messages. However, there is trade-off between reflection of actual link state information on LSDB and cost of sending LSU messages. To find a bandwidth-guaranteed path effectively, it is important to decide whether LSU messages are sent or not for the change of link sate. In this paper, we propose a threshold-based LSU algorithm using statistic to effectively decide for sending LSU messages and evaluates its performance by intensive simulations. Simulation results show that the performance of proposed scheme is superior to the existing LSU schemes.

• Journal of Korean Society of Transportation
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• v.23 no.7 s.85
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• pp.149-158
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• 2005

The object of this paper is to develop the shortest path algorithm. The existing shortest path algorithm models are developed while considering travel time and travel distance. A few problems occur in these shortest path algorithm models, which have paid no regard to cognition of users, such as when user who doesn't have complete information about the trip meets a strange road or when the route searched from the shortest path algorithm model is not commonly used by users in real network. This paper develops a shortest path algorithm model to provide ideal route that many people actually prefer. In order to provide the ideal shortest path with the consideration of travel time, travel distance and road cognition, travel time is predicted by using Kalman filtering and travel distance is predicted by using GIS attributions. The road cognition is considered by using space data of GIS. Optimal routes provided from this paper are shortest distance path, shortest time path, shortest path considering distance and cognition and shortest path considering time and cognition.

• Proceedings of the Korean Information Science Society Conference
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• 1999.10c
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• pp.566-568
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• 1999

현재는 데이터 통신망이 음성 통신망을 흡수하는 단계이다. 데이터 망이 기존의 음성 망이 가지는 영역을 포함하면서 광범위하게 활용되면서 앞으로 그 범위는 더욱 넓어질 것이다. 현재 급속히 팽창하고 있는 인터넷도 데이터 통신망이 진일보 하는데 커다란 역할을 하고 있다. 기존의 연결 지향형 방식의 패킷 통신과 달리 인터넷이 주로 비연결형 방식의 IP를 사용하기 때문에 새로운 개념의 데이터 전송이 요구되고 있다. 이러한 요구들로 인해 ATM, Gigabit Router, MPLS 등이 출현하게 되었고 현재는 MPLS가 가장 적합한 해결책으로 제시되고 있다. IETF 역시 이러한 MLS에 대한 표준안을 준비하고 있다. 이곳에서는 많은 장점을 가지는 MPLS(MultiProtocol Label Switch)망에서의 명령어 그리고 타이머를 가지는 레이블 예약방식의 경로 재설정 알고리즘을 제시한다. 방법은 경로 재설정시간을 단축하고 트래픽의 적절한 분배를 통하여 네트워크의 부하를 줄인다.

• Proceedings of the Korea Information Processing Society Conference
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• 2023.11a
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• pp.1084-1085
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• 2023

현재 국내 항만에서의 작업은 대부분 수작업으로 진행되기 때문에 다양한 안전사고 발생과 시간 및 비용 등의 손실이 우려된다. 이를 해소하고자 최적경로 알고리즘을 이용한 AGV 차량 및 자동화 크레인으로 무인 스마트 항만을 제안한다. RFID 인식으로 컨테이너의 정보를 확인하고, 각 경로의 노드 정보가 담긴 QR 코드 인식을 통해 최적으로 목적지에 달성하는 것이 핵심이다. 본 논문은 이러한 기능으로 시간 및 비용 절감, 효율 상승과 인명피해 및 안전사고 예방을 목표로 한다.

• Proceedings of the Korean Society of Computer Information Conference
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• 2010.07a
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• pp.47-50
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• 2010

본 논문은 현재 경찰청 및 각 지자체의 주도하에 수도권을 중심으로 새롭게 보급되고 있는 도시 교통 정보 시스템 (UTIS)과 국토해양부 및 한국 도로 공사 등을 중심으로 한 DSRC 기반의 교통 정보 시스템을 모두 활용하는 시스템 및 효율적인 경로탐색 알고리즘을 제안한다. 도시 교통 정보 시스템은 무선랜과 같은 프로토콜을 이용해서, 기존 단방향 방식인 TPEG의 주요 도로 위주의 제한된 교통 정보 단점을 극복하고 많은 지선를 포함한 교통 정보를 제공하고 있다. 그러나 대부분의 운전자들이 단지 도심 내에서만 운전하는 것이 아니고 고속도로 등을 통해서 장거리 운전도 하기 때문에 고속도로 상의 DSRC 기반의 서비스도 동일 단말에서 지원해야 하나의 단말에서 다양한 서비스를 지원받을 수 있다. 따라서 본 논문의 두 개의 다른 통신 모듈의 통합된 단말 시스템을 제안하고 기존에 제안된 UTIS 기반의 분산 경로 탐색 방식을 DSRC 기반의 고속도로 교통 정보를 활용해서 새로운 경로탐색 알고리즘을 제안한다. 또한 향후 추가적으로 이루어질 연구와 현재 다른 주체들의 주도로 이루어지는 서비스를 제도적으로 보완할 수 있는 방안도 제시한다.

• The Transactions of the Korea Information Processing Society
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• v.4 no.10
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• pp.2562-2570
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• 1997

This paper deals with the design and performance of the adaptive equalizer using high order statistics in order to improve the transmission characteristics of multipath fading channel. The multipath propagational phenomenon occurred in digital radio transmission causes the distortion and ISI of receiving signal. These are main reasons to increase the bit error rate and degrade the performance of receivers. In this paper, the adaptive equalization algorithm using high order statistics of received signal is used instead of CMA algorithm, Bussgang and Godard which are known widely. The performance of this algorithm (residualisi, recovered constellation, calculation) is presented varing SNR. As the result of the computer simulation, equalizer algorithm using high order statistics is better than CMA in the range of low SNR, $10{\sim}20dB$. Therefore, considering the actual communication systems which use the range of $14{\sim}20$ SNR, the adaptive equalizer using high order statistics can be used in the real multipath fading environment.

• Proceedings of the Korea Information Processing Society Conference
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• 2016.10a
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• pp.579-580
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• 2016

본 연구에서는 군집 로봇 체계에서 next-best-view(NBV)의 결정과 경로 계획(path planning)을 동시에 수행하는 효율적인 3차원 탐사 알고리즘을 제안한다. NBV 결정 및 경로 계획을 동시에 수행하는 단일 로봇 탐사 알고리즘에는 최근에 제안된 RH-NBVP[1]가 있다. 우리는 각 로봇에게 효율적으로 탐사 영역을 분배하는 Voronoi-biased multi-RRTs(VB-MRRTs)를 제시하며, 이를 통해 군집 로봇 체계에 RH-NBVP를 적용한다. 제시한 VB-MRRTs가 공간을 얼마나 점유하는지 분석하였으며, 3차원 시뮬레이션 상의 군집 로봇 체계에서 VB-MRRTs가 적용된 RH-NBVP의 탐사율 향상을 확인하였다.