• 한국HCI학회:학술대회논문집
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• 2006.02a
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• pp.902-908
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• 2006

We propose a scheme for more efficient navigation in a hierarchical file system. In the proposed scheme, a program running in the background computes the degree of relationship between a current file and others, and builds a list of the most related files. The current relationship metric being used by the program is a linear combination of five parameters: the name, the directory path, the type, the created time, and the last accessed time of a file. A simulated annealing algorithm is used in order to determine the weighting factors of the parameters. A set of experiments were conducted in order to access the effectiveness of the proposed scheme.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10a
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• pp.219-222
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• 1996

Authors ahve developed ALFLEX simulation program which can implement the flight simulation ad control system design of ALFLEX efficiently by using aerodynamic data provided by NAL/NASDA. Then we have designed and example of flight path and altitude control system of ALFLEX. The philosophy of the design method is explained in detail, and a flight simulation result is shown, which verifies the fine performance of the system.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1802-1803
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• 2011

The Korea Railroad Research Institute (KRRI) is developing the Bimodal-tram. The vehicle has a navigation control system (NCS) for automatic driving. The vehicle has to follow a reference path in automatic mode. NCS uses magnetic markers to calculate the vehicle position. The vehicle lane is marked with permanent magnets that are buried in the road. In this purpose, we show the characteristics and the configuration of NCS.

• Proceedings of the Korean Information Science Society Conference
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• 1998.10b
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• pp.620-622
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• 1998

Web 기반 시스템 구축시 저렴한 구축비용, 표준화된 문서환경, 클라이언트를 통일하지 않고도 어플리케이션의 구현이 가능한 장점 때문에 인터넷 프로토콜인 TCP/IP와 HTTP를 기반으로 시스템을 구축하려는 기업과 조직이 늘고 있다. 본 논문에서는 web 환경에서 시스템 구축시 적용할 수 잇는 web 기반 시스템 분석/설계 모형을 제안한다. 기존의 web 어플리케이션 개발 방법들이 데이터 분석에 기초를 둔 것과는 달리, 기업과 조직이 가지는 기능을 중심으로 web 어플리케이션을 분석하고, 파악된 기능에서 pageflow를 설계하여 사용자의 요구사항과 조직의 처리가 반영된 page와 네비게이션 경로(navigation path)를 설계할 수 있는 모형을 제시한다.

• IEMEK Journal of Embedded Systems and Applications
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• v.3 no.3
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• pp.126-135
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• 2008

The development of an unmanned vehicle basically requires the robust and reliable performance of major functions which include global localization, lane detection, obstacle avoidance, path planning, etc. The implementation of major functional subsystems are possible by integrating and fusing data acquired from various sensory systems such as GPS, vision, ultrasonic sensor, encoder, and electric compass. This paper focuses on implementing the functional subsystems, which are designed and developed by a graphical programming tool, NI LabVIEW, and also verifying the autonomous navigation and remote control of the unmanned vehicle.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.11
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• pp.2147-2151
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• 2011

In this paper, we propose the formation control algorithm for swarm robots. The proposed algorithm uses the artificial potential field(APF) to plan the global path of swarm robots and to control the formation movement. The navigation function generates a global APF for a leader robot to reach a given destination and an avoidance function generates a local APF for follow robots to avoid obstacles. Finally, some simulations show the validity of the proposed method.

• Proceedings of the Korean Information Science Society Conference
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• 1999.10a
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• pp.102-104
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• 1999

인터넷의 발전으로 WWW상에서 지도 정보를 서비스하는 사이트들이 늘어나고 있다. 본 논문은 이러한 WWW상의 지리 정보 서비스를 확장한 도로 주행 안내 시스템의 구현에 관하여 기술한다. 도로 주행 안내 시스템은 도로, 건물 등의 지리 정보를 표시해주며 사용자의 최단 경로질의를 받고 빠른 시간내에 최단경로를 탐색할 수 있어야 한다. 본 연구에서는 이러한 요구를 수용할 수 있도록 OODBMS, CORBA, Java를 사용하여 WWW상의 도로 주행 안내 시스템을 설계 및 구현하였다. 이를 위해 이 논문에서는 도로 데이터 캐싱과 그래프 모델링, HEPV (Hierarchical Encoded Path View) 알고리즘 구현 등의 사항을 기술하였다.

• Journal of Advanced Navigation Technology
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• v.23 no.2
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• pp.151-157
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• 2019

In geostationary satellite communications, which are widely used for broadcasting and communication, there is a path loss where the signal power on the path is largely reduced. It is important to consider rain attenuation when calculating link budget because the Ka band frequency is vulnerable to rain attenuation. In this study, rainfall trends were analyzed by using rainfall data from the year 2000 in four regions of Korea (Seoul, Incheon, Busan, Jeju) and the rainfall attenuation was calculated. This was used to analyse the satellite link budget and receiving performance for the down-link of the korea satellite COMS. In this study, the calculated G/T for the rainfall intensity of 0.5% per year using the rainfall data for 18 years increased by approximately $8.5dBK^{-1}$ compared to the ITU's zone-K rain model, and decreased by approximately $1dBK^{-1}$ compared to the precipitation data for 13 years from the TTA(Korea Telecommunications Technology Association). The results of this study can be used for the design of G/T in domestic-installed satellite ground station.

• Journal of Advanced Navigation Technology
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• v.16 no.6
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• pp.960-967
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• 2012

Wireless sensor network is used at the environment to obtain nearby information and since such information is transferred through wireless link, it causes unnecessary re-sending and disadvantage of big energy consumption at node. Because of this to select reliable, energy effective link, method of estimating quality on wireless link using RSSI(received signal strength indication), LQI(link quality indication), etc is needed on wireless link. To set up path extending survival time by reducing energy consumption of nodes at the wireless sensor network, the thesis selects with small standard deviation of LQI after obtaining LQI within each path. Additionally, LQI standard deviation routing algorithm is compared based on LQI algorithm such as minimum-LQI, hop-LQI weight and RF output -7dBm. According to the outcome, the algorithm suggested has superior characters such as the number of node, retransmission rate and network life span respectively compared to existing algorithm. Therefore, energy consumption can be efficiently reduced in case that LQI standard deviation routing scheme suggested by this paper is adapted to wireless sensor network.

• Journal of the Korean Institute of Intelligent Systems
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• v.18 no.5
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• pp.599-604
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• 2008

Recently, many researches for autonomous mobile system have been proposed, which can recognize surrounded environment and navigate to destination without outside intervention. The basic sufficient condition for the autonomous mobile system is to navigate to destination safely without accident. In this paper, we propose a path planning method in local region for safe navigation of autonomous system through evaluation of the road surface distortion(damaged/deformed road, unpaved road, obstacle and etc.). We use laser distance sensor to get the information on the road surface distortion and apply image binalization method to evaluate safe region in the detected local region. We show the validity of the proposed method through the computer simulation based on the artificial local road map.