• 대한교통학회지
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• 제27권2호
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• pp.73-82
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• 2009

컨시어지 서비스(Concierge Service)는 유비쿼터스 도시에서 제공되는 위치 기반 경로 안내 서비스이다. 유비쿼터스 도시는 언제 어디서나 모든 정보를 이용할 수 있는 도시이므로, 사용자는 컨시어지 서비스를 통해 언제 어디서나 자신의 위치 정보를 기반으로 경로를 안내받을 수 있다. 그러나 현재 제공 중인 경로안내 서비스는 GPS기반으로 위치정보를 결정하므로, GPS 음영지역이나 실내에서는 위치 정보를 얻기가 불가능하다. 실내에서의 위치 정보를 얻기 위해 유비쿼터스 컴퓨팅 시스템에서 여러 기술들을 이용한 연구가 활발히 이루어지고 있으나 아직까지 모든 곳에서 위치 정보를 얻을 수 있는 하나의 기술은 개발된 것이 없다. 그러므로 이러한 다양한 기술을 통하여 얻어지는 위치정보를 경로안내에 적용하기 위해서는 어떤 상황에서 얻어진 정보인지를 정의해줄 필요가 있다. 본 연구에서는 다양한 기술들을 통해 위치 정보를 얻을 수 있다는 가정 하에 컨시어지 서비스가 이루어지기 위한 기본조건들을 정의하고 위치정보활용을 위한 데이터구조의 표준안을 제안하였다. 이러한 표준안을 적용하면 어떤 기술을 통해 위치정보를 얻더라도 사용자는 어디서나 컨시어지 서비스를 이용할 수 있게 된다.

• 대한전자공학회논문지TC
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• 제42권7호
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• pp.1-6
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• 2005

증가하는 이동 통신망 가입자를 수용하기 위한 셀 크기의 소형화는 잦은 위치 갱신을 유발시켜 위치 관리 비용의 증가를 가져왔다. 본 논문에서는 [l]에서 향후과제로 남겨두었던 호 수신 확률에 근거한 위치 관리 기법의 비용을 분석하여 제안된 기법이 기존의 방식(IS-41)보다 위치 관리 비용을 줄일. 수 있음을 증명하였다. 그리고 분석에 의해 계산된 위치 관리 비용을 시뮬레이션 결과와 비교해 보았다. 그 결과, 제안된 기법은 단말의 호 도착률이 낮은 경우, 위치 갱신을 생략하는데서 얻어지는 비용의 감소로 기존의 위치 관리 기법보다 전체 위치 관리 비용을 줄일 수 있으며, 호 도착률이 높아지더라도 위치 관리 비용이 기존 방식의 위치 관리 비용을 초과하지 않음을 보였다.

• 산업공학
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• 제16권4호
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• pp.507-514
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• 2003

In personal communication systems location management of mobile terminals is required to connect incoming calls to the mobile terminals. Investigation of effective location update and paging strategies is important to reduce the cost of location management. In this study, we propose a paging strategy considering the mobile terminals' residence patterns. The first paging area is characterized by the set of cells in the location area where mobile terminals usually stay for a significant period of time. The rest of cells in the location area are included into the second paging area. To reduce the paging cost the first paging area is decided by reflecting various residence patterns of mobile terminals. For an incoming call, the sequential paging is performed in the order of the paging area. Thus the paging cost is greatly reduced, especially when the called mobile terminal is located in the first paging area. The proposed strategy is expected to be more effective than an existing strategy that uses the anchor cell in the location area.

• 제어로봇시스템학회논문지
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• 제13권7호
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• pp.711-717
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• 2007

Location information will become increasingly important for future Pervasive Computing applications. Location tracking system of a moving device can be classified into two types of architectures: an active mobile architecture and a passive mobile architecture. In the former, a mobile device actively transmits signals for estimating distances to listeners. In the latter, a mobile device listens signals from beacons passively. Although the passive architecture such as Cricket location system is inexpensive, easy to set up, and safe, it is less precise than the active one. In this paper, we present a passive location system using Cricket Mote sensors which use RF and ultrasonic signals to estimate distances. In order to improve accuracy of the passive system, the transmission speed of ultrasound was compensated according to air temperature at the moment. Upper and lower bounds of a distance estimation were set up through measuring minimum and maximum distances that ultrasonic signal can reach to. Distance estimations beyond the upper and the lower bounds were filtered off as errors in our scheme. With collecting distance estimation data at various locations and comparing each distance estimation with real distance respectively, we proposed an equation to compensate the deviation at each point. Equations for proposed algorithm were derived to calculate relative coordinates of a moving device. At indoor and outdoor tests, average location error and average location tracking period were 3.5 cm and 0.5 second, respectively, which outperformed Cricket location system of MIT.

• Korean Journal of Acupuncture
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• 제37권4호
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• pp.245-252
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• 2020

Objectives : The objective of this study was to examine the acupoint location of Kyoshin (KI8) from classic literatures. Methods : A review of KI8 location along the meridian route from 18 classics of acupuncture and moxibustion - 『Huangdineijing·Lingshu』, 『Huangdimingtangjingjixiao』, 『Zhenjiujiayijing』, 『Huangdineijingtaisu』, 『Huangdimingtangjiujing』, 『Beijiqianjinyaofang』, 『Waitaimiyaofang』, 『Ishimpo』, 『Taipingshenghuifang』, 『Tongrenshuxuezhenjiutujing』, 『Shengjizonglu』, 『Zhenjiuzishengjing』, 『Shisijingfahui』, 『Shenyingjing』, 『Zhenjiujuying』, 『Yixuerumen』, 『Zhenjiudacheng』, and 『Yizongjinjian』 - was performed. Then, KI7 location on classics and current standard KI8 location were compared. Results : Based on modern standard acupoint location system, the acupoint of KI8 is located on the medial aspect of the leg, in the depression posterior to the medial border of the tibia and it is on the route of spleen meridian. But no classics of acupuncture and moxibustion said KI8 was located on the route of spleen meridian. In addition, KI8 location on classics was largely described as being located in front of KI7, but only in 『Yizongjinjian』 was it written that KI8 was located posterior to KI7. Conclusions : Through a classic literature review, it is possible to explain that KI8 is located posterior to spleen meridian. The acupoint of KI8 seems to be located between medial border of flexor pollicis longus and flexor digitorum longus based on anatomical location.

• 한국멀티미디어학회논문지
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• 제25권8호
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• pp.1069-1074
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• 2022

IP mobility can be handled in different layers of the protocol. Mobile IP has been proposed to handle the mobility of Internet hosts in the network layer. Recently, a new method based on the SIGMA mobility architecture has been proposed to support mobility management with reduced packet loss and latency. The location management structure is not suitable for frequent mobile handover due to the high mobility of the user with this transport layer solution. In this paper, we propose a location management optimization method in a mobile communication network by applying hierarchical location management using MMPs(Mobility Management Points) for transport layer mobility management. Therefore, we propose an efficient hierarchical mobility management structure even between heterogeneous wireless networks using MMPs for the probability that a mobile terminal can change multiple location areas between two messages and calls. The proposed method shows reduction in location update cost and data retrieval cost using MMPs, and as opposed to mobility appearing in time intervals with the minimum cost required to reach 90% of the stabilized cost, the mobility location update search, location It was found that the message processing cost per area was reduced.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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• pp.849-851
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• 2003

A location-based service or LBS in a cellular telephone network is a service provided to the subscriber based on his current geographic location. This position can be known by user entry or a GPS receiver that he carries with him, but most often the term implies the use of a function built into the cell network that uses the known geographic coordinates of the base stations through which the communication takes place. One implication is that knowledge of the coordinates is owned and controlled by the network operator, and not by the end user. Location utility service provides two kinds of functions, geocoder and reverse geocoder. Geocoder converts an address into a coordinate and reverse geocoder changes a coordinate into an address. Because location utility service is the first step to progress LBS, various servises such as directory, routing, presentation, and etc require to access that. In this paper, we will describe the architecture of LBS platform and the concept and the role of location utility service.

• 한국군사과학기술학회지
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• 제7권4호
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• pp.61-69
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• 2004

This paper presents a new analytical method for estimating the location of a target using directional data. Based on a nonlinear programming (NLP) problem formulated for the line method, which is a well known algorithm for two-dimensional location estimation, we present a method to find an optimal solution for the problem. Then we present a two-stage method for better location estimation based on the NLP problem. In addition, another two-stage method is presented for location estimation problems in which different types of observers are used to obtain directional data based on the analysis of the maximum likelihood estimate of the target location. The performance of the suggested method is evaluated through simulation experiments, and results show that the two-stage method is computationally efficient and highly accurate.

• 전기학회논문지
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• 제67권9호
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• pp.1146-1151
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• 2018

Recently, researches on the intelligence of electric power facilities have been trying to apply artificial intelligence techniques as computer platforms have improved. In particular, faults occurring in substation should be able to quickly identify possible faults and minimize power fault recovery time. This paper presents fault location technique for 154kV substation using neural network. We constructed a training matrix based on the operating conditions of the circuit breaker and IED to identify the fault location of each component of the target 154kV substation, such as line, bus, and transformer. After performing the training to identify the fault location by the neural network using Weka software, the performance of fault location discrimination of the designed neural network was confirmed.

• Journal of Information Processing Systems
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• 제1권1호
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• pp.86-95
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• 2005

Location-based services or LBS refer to value-added service by processing information utilizing mobile user location. With the rapidly increasing wireless Internet subscribers and world LBS market, the various location based applications are introduced such as buddy finder, proximity and security services. As the killer application of the wireless Internet, the LBS have reconsidered technology about location determination technology, LBS middleware server for various application, and diverse contents processing technology. However, there are fears that this new wealth of personal location information will lead to new security risks, to the invasion of the privacy of people and organizations. This paper describes a novel security approach on open LBS service to validate certificate based on current LBS platform environment using XKMS (XML Key Management Specification) and SAML (Security Assertion Markup Language), XACML (extensible Access Control Markup Language) in XML security mechanism.