• Journal of Communications and Networks
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• 제15권1호
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• pp.54-60
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• 2013

In this paper, a novel method called location-based delivery (LBD), which combines the short message service (SMS) and global position system (GPS), is proposed, and further, a realistic system for tracking a target's movement is developed. LBD reduces the number of short message transmissions while maintaining the location tracking accuracy within the acceptable range. The proposed approach, LBD, consists of three primary features: Short message format, location prediction, and dynamic threshold. The defined short message format is proprietary. Location prediction is performed by using the current location, moving speed, and bearing of the target to predict its next location. When the distance between the predicted location and the actual location exceeds a certain threshold, the target transmits a short message to the tracker to update its current location. The threshold is dynamically adjusted to maintain the location tracking accuracy and the number of short messages on the basis of the moving speed of the target. The experimental results show that LBD, indeed, outperforms other methods because it satisfactorily maintains the location tracking accuracy with relatively fewer messages.

• 정보처리학회논문지D
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• 제9D권5호
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• pp.827-836
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• 2002

이동 객체 관리 시스템은 사람, 동물, 자동차 등과 같이 시간에 따라 위치를 변경하는 시공간 데이터를 관리한다. 이러한 이동 객체 관리 시스템은 차량 위치 추적, 디지털 전장, 위치 기반 서비스 등에 적용된다. 그러나 기존의 이동 객체 관리 시스템은 이동 객체의 과거 및 미래의 위치정보를 개별적으로 관리하며, 불확실한 과거 및 미래의 위치 추정 방법을 구체적으로 제시하지 못한다. 따라서 이 논문에서는 이동 객체의 이력 정보를 관리할 뿐만 아니라, 데이터베이스에 저장된 이력정보를 이용한 이동 객체의 과거 및 미래의 위치 추정이 가능한 시스템을 제안한다. 이를 위해 차량 위치 추적을 위한 이동 객체를 모델링하고 이동 객체 데이터베이스 구조를 제시한다. 아울러 제안 시스템의 실행 모델을 제시하고, 이를 차량 추적을 위한 가상 시나리오에 적용한다.

• 한국경영과학회지
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• 제33권3호
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• pp.43-58
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• 2008

In this paper, we have presented a dynamic, predictive location update scheme that takes into account each user's mobility patterns. A user's past movement history is used to create two-dimensional transition probability matrix which makes use of two directional consecutive location areas. A mobile terminal utilizes the transition probability to develop a predictive path which consists of several predictive nodes and then the location update is saved as long as a mobile user follows the predictive path. Using continuous-time Markov chain, cost functions of location update and paging are derived and it is shown that the number of predictive nodes can be determined optimally. To evaluate the proposed scheme, simulations are designed and the numerical analysis is carried out. The numerical analysis features user's mobility patterns and regularity, call arrival rates, and cost ratio of location update to paging. Results show that the proposed scheme gives lower total location management cost, compared to the other location update schemes.

• 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.

• 컴퓨터교육학회논문지
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• 제8권6호
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• pp.123-132
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• 2005

이동망의 위치관리에서 위치갱신 비용 최소화를 위한 많은 연구 결과들이 있다. 위치갱신 비용의 최소화를 위해서는 각 사용자들의 이동 패턴을 고려해야만 한다. 본 논문은 과거의 사용자 이동에 대한 이력으로부터 각 사용자에 대한 위치영역 리스트 생성과 이를 위한 3 단계 페이징 방안을 제안한다. 사용자의 이동은 공간적으로 뿐만 아니라 시간적으로도 규칙적인 패턴이 존재한다. 따라서 제안된 위치영역 리스트 생성방안은 이상의 2가지 측면에서 사용자의 방문빈도를 이용하여 규칙성을 발견하고, 이에 대한 위치영역리스트를 생성한다. 제안된 방안의 성능분석 위해서 제안된 방안에 대하여 사용자 이동 패턴을 고려한 모의실험을 수행하였다. 모의실험 결과 제안된 방안이 위치관리 비용 측면에서 장점이 있음이 확인되었다.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2002년도 가을 학술발표논문집 Vol.29 No.2 (3)
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• pp.661-663
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• 2002

This paper introduces a dynamic location management with hierarchical location area, which helps in reducing location update(LU) and paging cost and hence total location management cost. Users are assigned to appropriate location area level utilizing the call-to-mobility ratio(CMR) value. CMR values are calculated each time a user enters a new cell by computing its mobility rate and incoming call rate, which are the two key factors for defining the size of the location area.

• 정보처리학회논문지A
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• 제9A권4호
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• pp.413-420
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• 2002

보관 중인 제품의 정확한 위치를 파악하는 것이 창고관리의 필수적인 요소이다. 그러나 제품이 빈번하게 위치를 변경하며 보관되는 경우에는 그 위치 파악이 어렵게 되며 이로 인해 효율적 창고관리가 불가능해진다. 본 논문에서는 임베디드 시스템과 무선 랜을 이용하여, 이러한 이동성이 높은 재고단위(SKU : Stock Keeping Unit)의 창고 내 위치관리에 응용할 수 있는 새로운 시스템을 제안한다. 시스템은 RFID(Radio Frequency IDentification)와 관리 단말기, 모바일 기기인 휴대폰과 PDA 그리고 중앙 관리 시스템으로 구성된다. 시스템의 사례로 이동성이 높은 재고단위의 모델인 대형 중고자동차의 위치관리시스템을 선택하였으며, 시스템이 운용되는 각 부서의 업무를 분석 후 기능별로 구현하였다. 본 연구를 통하여 무선 랜이 접목된 임베디드 시스템이 이동성 높은 재고단위의 입출고 상황과 창고 내에서의 위치를 실시간 적으로 정확하게 파악할 수 있어, 창고의 운영 및 관리를 체계적으로 처리할 수 있음을 보인다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2005년도 추계종합학술대회
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• pp.229-232
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• 2005

Many kinds of communication systems will be co-existed in the next generation communication environment. Location management will be one of the most important strategies in the future communication network. Whether the user gets the service in any kind of communication system, it is required to know the location of the user properly and manages this location information efficiently. In this paper, mobile IP and WCDMA systems are considered as next generation communication systems. We improve the performance of communication in heterogeneous networks adjusting the conventional region-based location management strategy in homogeneous network. This strategy can be adjusted dynamically to the communication system on the basis of packet-to-mobility ratio (PMR) in mobile IP system or call-to-mobility ratio (CMR) in WCDMA system, lots of different system parameters, and movement pattern of the user. This can be also based on the performance analysis with considering signaling cost and database access cost.

• Journal of the Korean Data and Information Science Society
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• 제18권4호
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• pp.1157-1170
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• 2007

LBS must manage various context data and make the best use of this data for application service in ubiquitous environment. Conventional mobile object data management architecture did not consider process of context data. Therefore a new mobile data management framework is needed to process location context data. In this paper, we design a new context management framework for a location based application service. A suggestion framework is consisted of context collector, context manager, rule base, inference engine, and mobile object context database. It describes a form of rule base and a movement process of inference engine that are based on location based application scenario. It also presents an embodiment instance of interface which suggested framework is applied to location context interference of mobile object.

• 한국정보처리학회논문지
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• 제7권4호
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• pp.1279-1289
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• 2000

Recently, research activities for combining portable computer technology and wireless communication technology are in progress to realize mobile computing environment that designed to support mobile hosts in the existing network environments. For PCN environments, the location management strategies are particularly emphasized among various strategies necessary for the mobile computing environment. Location management strategy for PCN environment, which is mostly based on the IS-41 standards brings an issue that additional network traffics are generated to deliver updata messages to home location server whenever a mobile host changes its location server. In this paper, we propose an innovative updata strategy and a search strategy that resolves the problem shown in the IS-41 scheme for HLR/VLR structure of CDMA environments. Also, this paper presents the performance comparison of proposed scheme and scheme used in IS-41 obtained from a simulation. The simulation was conducted based on the number of messages, the rate of database accesses, and the number of hops visited when the location management scheme is executed.