• 센서학회지
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• 제16권4호
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• pp.270-276
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• 2007

A location-aware system, which is capable to detect a user's whereabout in a region and provide real-time location information in outdoor environment is designed and fabricated, specifically using the GPS (global positioning system) as key technology in view of its stability and high precision in outdoor environment. Experiment is conducted to test this application in campus-based environment. Once GPS receiver detects specific location which is tagged with GPS coordinates, the system provides information relevant to that context and user can operate and react accordingly. Besides, this location-aware system is able to provide user with the route in order to get to a desired place by detecting the direction that the user is moving towards from his/her initial location. The mapping data is transferred via wireless LAN to PDA carried by the user as well as to the back-end system on real-time basis. The test result is analyzed and discussed to validate the effectiveness of using GPS in implementing this system and indicates future works that could be made to improve this prototype to be implemented in other applications, such as theme park, tourist attraction spot or recreational park.

• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2003년도 Proceeding
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• pp.113-117
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• 2003

As the wireless communication technology advances rapidly, a personalization technology can be incorporated with the mobile Internet environment, which is based on location-based services to support more accurate personalized services. A location-based personalized recommender system is one of the essential technologies of the location-based application services, and is also a crucial technology for the ubiquitous environment. In this paper we propose a framework of a location-based personalized recommender system for the mobile Internet environment. The proposed system consists of three modules the interface module, the neighbor selection module and the prediction and recommendation module. The proposed system incorporates the concept of the recommendation system in the Electronic Commerce along with that of the mobile devices for possible expansion of services on the mobile devices. Finally a service scenario for entertainment recommendation based on the proposed recommender system is described.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 A
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• pp.712-714
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• 2005

With rapid growth of industry, underground power delivery systems are growing so rapidly and its capacity also growing. So if there are any accident in underground power cable, its inference is too great to count. So power system operators should find Its fault location as soon as possible and replace it But it is difficult to find its fault location for underground power cable. We are developing fault location system for underground power cable which can detect its fault location exactly. This system usually monitor underground power cable on-line But if there are an accident, it record Its transient signal and we can calculate fault location by analyzing it. To develop fault location system for power cable, we needed fault simulation system and we installed it physically and tested at various point. in this thesis, we describe on signal processing technology to detect fault location on power cable and on the result of tested fault location performance.

• 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.

• International journal of advanced smart convergence
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• 제7권3호
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• pp.61-65
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• 2018

A Location Register(LR) system manages each subscriber's location information, which continuously changes in mobile cellular network. For this purpose, the LR database system provides backup management facilities. The objectives of this paper are to identify the problems of the current LR system through rigorous analysis, to suggest solutions to them. I proposed efficient backup methods that takes into account the characteristics of LR database transactions. In the proposed backup method, I use two kinds of dirty flags in order to solve the performance degradation problem caused by frequent registration- location operations.

• Journal of Multimedia Information System
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• 제8권1호
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• pp.11-16
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• 2021

This study developed a design to estimate the location of rescue demander using the sound system at disaster site, in the conditions of indoor positioning cannot be performed properly. It is a location tracing system through smart phone application. It generates sound wave information of rescuer at the rescue site, and it can be used as assistant means for indoor location tracing at the disaster site using sound wave receiving measurement technology.

• 제어로봇시스템학회논문지
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• 제15권11호
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• pp.1150-1156
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• 2009

The spread of wireless Internet technology development and applications with location information in the form of location-based services are more varied. In particular, where you recognize the location of objects such as people and things, and to provide valuable services based on ubiquitous, location-based services (Ubiquitous Location Based Services: u-LBS) is emerging as an important service. In this paper precise location data to the car crash through the location and offers related service system. In this paper the precise location tracking proposed by the concept of the Rail, road, to extract the location Data Matching Data and the current location is obtained. System used in GPS Packet and information about the location of the vehicle collision and the collision time, the vehicle consists of NodeID is about. Using these data, a packet is to be created when the conflict between vehicles in the vehicle will be sent to Gateway. Gateway to the packets that were sent from the Server to determine whether the conflict is that in an emergency situation, Emergency Center for location information and let me know whether or not the conflict will be measured. Also, for those on the outside of an emergency such as a family related to the wireless terminal wireless (PDA, cell phone) is to let me know. Server get into the conflict that was configured to store information on the Database. Additionally, the proposed u-LBS system to verify the validity of the experiment was performed.

• 산업기술연구
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• 제28권B호
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• pp.9-14
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• 2008

In the Reporting Cell Location Management (RCLM) system, a subset of cells in the network is designated as the reporting cells. Each mobile terminal performs location update only when it enters one of these reporting cells. When a call arrives, the paging is confined to the reporting cell the user last reported and the neighboring bounded non-reporting cells. Frequent location update may result in degradation of quality of service due to interference. Miss on the location of a mobile terminal will necessitate a search operation on the network when a call comes in. We must decide the number of reporting cells and which cell should be reporting cell to balance the registration (location update) and search (paging) operations to minimize the cost of RCLM system. This paper proposes a simulated annealing (SA) for optimization of RCLM system.

• 산업경영시스템학회지
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• 제30권4호
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• pp.103-110
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• 2007

The facility location in designing a supply chain network is an important decision problem that gives form, structure, and shape to the entire supply chain system. Location problems involve determining the location, number, and size of the facilities to be used. The optimization of these location decisions requires careful attention to the inherent trade-offs among service time, inventory costs, facility cost, transportation costs. This paper presents a strategy that provides the best locations of distribution centers using GIS(Geographical Information System) assuming the limitation of delivery time. To get the best strategy of the location of distribution centers, we use the new loss functions as a penalty when the delivery time is violated

• 한국IT서비스학회지
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• 제9권4호
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• pp.207-217
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• 2010

This paper is concerned with a protection system for the mentally handicapped, which is utilizing a GPS receiver and mobile communications. The protection system consists of a location notification equipment, a location identification and management server, and a cell phone of guardian. The location notification equipment is made up of a GPS receiver, a CDMA communication module and a microprocessor. The equipment transfers the location of the mentally impaired to the location identification and management server when the handicapped gets out of a certain bound of the designated facility. The server marks the handicapped's location on the map in the server and also notifies the guardian's cell phone of the locations. With applying the proposed protection system to social welfare organizations related to the mentally handicapped, it is expected to efficiently contribute to the promotion of the handicapped's welfare.