• The Journal of the Korea institute of electronic communication sciences
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• v.19 no.3
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• pp.483-496
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• 2024

This paper proposes a location-based inter-beam handover event considering terminal mobility to enhance the service quality for terminals in satellite networks. The terminal continuously measures the distance between the serving cell and neighboring cell centers, and checks whether the handover event condition is satisfied, taking into account the terminal's velocity. Performance analysis results demonstrate that the proposed location-based handover event reduces the frequency of unnecessary handover event triggering compared to the conventional received signal strength-based handover event, thereby improving the service continuity of the terminal.

• Journal of the Institute of Convergence Signal Processing
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• v.13 no.1
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• pp.32-38
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• 2012

Each sensor node can know its location in several ways, if the node process the information based on its geographical position in sensor networks. In the localization scheme using GPS, there could be nodes that don't know their locations because the scheme requires line of sight to radio wave. Moreover, this scheme is high costly and consumes a lot of power. The localization scheme without GPS uses a sophisticated mathematical algorithm estimating location of sensor nodes that may be inaccurate. AHLoS(Ad Hoc Localization System) is a hybrid scheme using both GPS and location estimation algorithm. In AHLoS, the GPS node, which can receive its location from GPS, broadcasts its location to adjacent normal nodes which are not GPS devices. Normal nodes can estimate their location by using iterative triangulation algorithms if they receive at least three beacons which contain the position informations of neighbor nodes. But, there are some cases that a normal node receives less than two beacons by geographical conditions, network density, movements of nodes in sensor networks. We propose an indirect localization scheme for low-density sensor nodes which are difficult to receive directly at least three beacons from GPS nodes in wireless network.

• Journal of Internet Computing and Services
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• v.18 no.5
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• pp.31-38
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• 2017

Recently with the rapid development of LBS (Location-based Services) technology, approaches of protecting user's location have gained tremendous attentions. For using LBS, users need to forward their real locations to LBS server. However, if the user sends his/her real location to LBS server, the server will have the all the information about user in LBS. Moreover, if the user opens it to LBS server for a long time, the trajectory of user may be released. In this paper, we propose GTC (Grid-based Trajectory Cloaking) method to address the privacy issue. Different from existing approaches, firstly the GTC method sets the predicting trajectory and divides the map into $2^n*2^n$ grid. After that we will generate cloaking regions according to user's desired privacy level. Finally the user sends them to LBS server randomly. The GTC method can make the cost of process less than sequential trajectory k-anonymity. Because of confusing the departure and destination, LBS server could not know the user's trajectory any more. Thus, we significantly improve the privacy level. evaluation results further verify the effectiveness and efficiency of our GTC method.

• Journal of Korean Society for Geospatial Information Science
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• v.24 no.1
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• pp.51-59
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• 2016

Global consumption of fossil fuels continues to increase. As developing countries use fossil fuel as much as the existing fossil fuel using countries, the total amount of fossil fuel consumed has risen. The finite fossil energy depletion insecurity have become serious. In addition, fossil energy is caused by environmental pollution, economic and social problems remain in assignments that need to be addressed. Although solar power is clean and has many benefits, there are several problems in the process of installing a solar power plant. To solve these problems, floating photovoltaic plants has emerged as an alternative. This floating photovoltaic plants location analysis has not been made yet. In this study, the conditions of the floating photovoltaic plants location is analyzed with the Analytic Hierarchy Process using the terrain and climate factors. The score is assigned to the attribute information of each factor by the classification table. After multiplied by the weight the result is analyzed by visualization of the score. As the result, the score of the northen part of Gyeongsangbuk-do province is higher than the southern part of Gyeongsangbuk-do province. Especially Andongho lake in Andong City and the reservoir in Yeongyang-Gun are extracted as the optimal location. The score of the river boundary is low not the center of the river stream. It is expected that this study would be a more accurate floating solar power plant location analysis.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.10a
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• pp.479-482
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• 2003

Edge, detected from image processing includes variety of information about original image's location and shape etc. So a lot of researches for detecting those edges have been continuing even now. And with the recent progress of wavelet theory which is presented as a new technique of signal processing fields, wavelet transform is being applied to many fields which analyzes singularities of image. For this reason, this paper detected original image's edge from the information such as local maximum, direction, and location of the wavelet transform data by using wavelet function which is independent of width of line.

• Proceedings of the Korean Information Science Society Conference
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• 2006.06c
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• pp.34-36
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• 2006

본 논문은 다양한 위치 획득 시스템에 따라 다른 형식을 가지는 위치 데이터와 이에 따른 표준의 차이를 해결하기 위해 DMLI(Description Model for Location Information)을 제안한다. DMLI는 다른 형식으로 표현된 위치 데이터에 대한 메타데이터를 재정의 하지 않고, 모두의 의미를 포괄하는 메타데이터로 재분류하는 분류체계 모델이다. DMLI는 시설물(Facility), 장소(Place), 서비스(Service) 요소들로 구성된다. 시설물은 공간을 정의하는 최상위 요소로 공간 사용목적과 용도 및 기능에 따른다. 장소는 시설물을 구성하는 최하위 요소다. 서비스는 장소에서 제공 가능한 서비스를 말한다. 또한 위치관련 메타데이터 요소간의 정보를 정의한 사전을 이용하여 기존의 위치 데이터에 대한 메타데이터 요소를 DMLI에서 제안한 메타데이터 요소로 변환이 가능하다. 사전을 이용함으로서 또 다른 형식의 위치 데이터가 입력되어도 DMLI 형식으로의 변환이 용의하다. DMLI 형식으로 재분류된 위치관련 메타데이터들은 공간 사용 목적과 제공 가능한 서비스를 명확히 표현한다. 또한 위치관련 검색, 통계 등의 서비스를 제공하는 어플리케이션을 통하여 다양하게 응용되어 사용된다.

• Journal of Korea Society of Industrial Information Systems
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• v.19 no.2
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• pp.67-72
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• 2014

Zigbee is a wireless communication technology optimized for Wireless Sensor Network environment. Implementation of location estimation system is based on Zigbee. In this paper, we implement mobile information system using zigbee technology. The proposed system is composed of mobile terminal software and mobile reader softwrae. We also used our hardware in previous system.

• Proceedings of the Korea Inteligent Information System Society Conference
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• 2004.11a
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• pp.189-192
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• 2004

The present much information of internet has to exist for innumerable user so that couldn't satisfy there's a variety of demand. so they have a demerit that search unnecessary information. However Web service is different with other mass media because It is possible that enable Mass Customization for Personalization strategy. In The paper suggest reasoning system that detect user connection location by using indirect abstraction techniques a kind of Case-based reasoning techniques.

• Annual Conference of KIPS
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• 2010.11a
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• pp.879-882
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• 2010

본 연구는 idle 상태의 단말을 위한 이종 무선 통신망 환경에서 네트워크 선택 알고리즘을 제안한다. 제안 하는 알고리즘은 셀과 사용자 각각의 상대적 상태 정보를 이용하는 프로필기반 네트워크 선택 프레임워크(Profile-based Network Selection Framework, PNSF)에 기반한다. PNSF 는 traffic status, mobility, 그리고 QoS (Quality of Service) 카테고리의 정보들을 바탕으로 셀과 사용자의 프로필을 생성한다. 생성된 프로필들을 3 차원의 프로필 공간에서 위치 시키고 각 셀과 사용자 프로필 사이의 거리를 각 카테고리를 구성하는 요소의 정적 특성을 반영하여 계산한다. 사용자는 최종적으로 가장 거리가 긴 셀을 선택하여 location update 를 수행한다. 본 연구에서 제안하는 알고리즘은 이종의 무선통신망 환경의 특성과 idle 모드의 특성을 반영하여 location update 의 발생 빈도를 합리적으로 줄이면서도 급증하는 데이터 통신 사용을 고려하여 사용자가 네트워크에 전체에 적절히 분산되도록 선택한다.

• Proceedings of the Korean Society of Computer Information Conference
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• 2023.07a
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• pp.255-256
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• 2023

본 논문은 실시간으로 지하철의 위치를 추적하고, 사용자에게 정확한 정보를 제공한다. 사용자는 모바일 푸시 알림을 통해 다가오는 정류장을 인식하고 놓치지 않고 하차할 수 있다. 웹 기반 솔루션으로 개발되어 사용자 친화적인 인터페이스를 제공하며, 승객들의 편의와 이동 시간 단축에 기여한다. 이 서비스는 실시간 지하철 위치, 알람 서비스, 모바일 푸시 알림, 웹 기반 솔루션, 사용자 경험을 포함한 다양한 기술과 요소들을 통합한다. 전반적으로, 이 서비스는 승객들에게 효율적이고 편리한 지하철 이용을 제공하여 승객 만족도를 높이고 이동 경험을 개선한다.