• The Journal of the Korea Contents Association
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• v.18 no.1
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• pp.64-75
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• 2018

With the development of location-aware technologies and the activation of smart phones, location based social networks(LBSN) have been activated to allow people to easily share their location. In particular, studies on recommending the location of user interests by using the user check-in function in LBSN have been actively conducted. In this paper, we propose a location recommendation scheme considering time and user activities in LBSN. The proposed scheme considers user preference changes over time, local experts, and user interest in rare places. In other words, it uses the check-in history over time and distinguishes the user activity area to identify local experts. It also considers a rare place to give a weight to the user preferred place. It is shown through various performance evaluations that the proposed scheme outperforms the existing schemes.

• The KIPS Transactions:PartA
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• v.16A no.5
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• pp.381-388
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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 becoming more diverse. In particular, where you recognize the location of objects such as people and things and to provide valuable services based on the ubiquitous and location-based services are emerging as an important service. The collision between the vehicle position measurement in this thesis and offers related service system. Used in the proposed system, the GPS PACKET with information about the location and time of collision for the vehicle crash, the vehicle consists of a NodeID. Cause a conflict between these data at the vehicle, the vehicle through the gateway from the server to decide whether to go on to determine that an emergency situation, Emergency Center, the location information and giving information about whether the conflict is measured. Also, for such an emergency, such as a family on the outside of the wireless terminal related to Wireless (PDA, Phone) is to let me know. The server to want to save the crash information to the database of configuration. Additionally, the proposed U-LBS system to verify the validity of the experiment was performed.

• The Journal of the Korea institute of electronic communication sciences
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• v.17 no.4
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• pp.571-576
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• 2022

Due to the epochal development of the unmanned technology, the importance of LDT(: Location Detection Technology), which accurately estimates the location of a user or object, is dramatically increased. TOA(: Time of Arrival), which calculates a location by measuring the arrival time of signals, and TDOA(: Time Difference of Arrival) which calculates it by measuring the difference between two arrival times, are representative LDT methods. Based on the signals received from three or more base stations, TOA calculates an intersection point by drawing circles and TDOA calculates it by drawing hyperbolas. In order to improve the radio shadow area problem, a huge number of repeaters have been installed in the urban area, but the signals received through these repeaters may cause the serious error for estimating a location. In this paper, we propose an efficient location estimation technique using the signal received through the repeater. The proposed approach estimates the location of MS(: Mobile Station) employing TOA and TDOA methods, based on signals received from one repeater and two BS(: Base Station)s.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.23 no.6
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• pp.27-32
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• 2023

Location sharing through apps is increasing, such as finding a friend's location or sharing delivery status on the Internet. However, location information is important personal information, and in some cases can be misused for crimes, and so encryption of location information is essential when developing such apps. This paper develops an app that encrypts and shares location information between friends for purposes such as finding friends and deciding meeting locations. To improve encryption performance, the symmetric key was encrypted and transmitted using an asymmetric key, and for location sharing, only the symmetric key was used to encrypt it. The proposed app was developed on iOS, and performance measurements showed that encryption of location information was at least 5,000 times faster when using a symmetric key than when using an asymmetric key.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.5
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• pp.84-92
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• 2020

This paper describes the estimation method of cable fault location in rocket motors using M-sequence (Maximal Length Sequence). In order to estimate the location of a cable fault, three methods have been usually used: TDR (Time Domain Reflectometry), FDR (Frequency Domain Reflectometry), and TFDR (Time-Frequency Domain Reflectometry). However, these methods suffer the disadvantage of requiring users to be close to a test field, which is dangerous. The estimation method of cable fault location using M-sequence is proposed to solve this problem. The proposed method can make use of DAS (Data Acquisition System). The experiments were three cases: damaged, open, and short. The RG-58 coaxial cable was used in the experiments. As a result, the proposed method has better performance than that of conventional methods such as TDR and TFDR.

• Journal of the Korea Society of Computer and Information
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• v.15 no.3
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• pp.121-128
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• 2010

Whenever and wherever, recognizing location of object such as human as well as things, ubiquitous Location-Based Service which provides useful service based on this are rising as an important service. In this paper, we implemented customized real time 1:1 e-CRM system that can communicate with user's mobile phone through using Location-Based Service of mobile phone. Among various scenarios that are applicable to designed system, development and test were conducted based on scenario that provides shopping information and discount information to customers through SMS as they approach to vicinity of large discount store and allow them to download discount coupons through Call Back. The suggested system will be applied to various service event and can be used as a customized real time marketing method according to user's personal activity area.

• Journal of Korean Society for Geospatial Information Science
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• v.3 no.2 s.6
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• pp.131-136
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• 1995

In this paper, We explain the development of helicopter avation information system which provides the current location and other pre-saved informations in order to guarantee the safe aviation. The system we developed has the functions such as displaying digital map data and current location, route planning, displaying the rate of deviation, calculating and displaying the cross sectional view through the route and providing a real-time speed, heading and other informations. In this system, we use GPS to get the current location, made the 1:250,000 digital map to display the current location and made the cross sectional view from the DEM(Digital Elevation Mode)) data to help safe aviation. This system provides many kinds of route setting methods by using UTM coordinates, Lati. Longi, coordinates, database of heliport location, scanned map, etc., and displaying the heading and distance. Moreover, it also has a characteristic of providing a consistent user interface.

• Journal of the Society of Disaster Information
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• v.15 no.2
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• pp.282-291
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• 2019

Purpose: In recent, mobile technology, as an axis of the fourth industry paradigm, is evolving into our daily life, economic activities and disaster safety management. However, since the location information service is insufficient, it is difficult to response the emergency situation adequately in the golden time. The purpose of this study is to propose a method to fine precisely the location of people who are in need of an emergency in the event of accidents and disasters. Method: This study investigates and compares existing literature and safety apps for national index number NFC application development. In addition, the system structure and the design method through the element technology through analysis of necessary function of the demander were carried out. Results: The results of this study were developed as a design and system that can be implemented in both direction and function to inform the location for emergency situation or disaster reporting in mobile. Conclution: It is possible to provide the disaster safety location service which can be utilized by the citizens in case of crisis by unifying the address system and integrating the location information using NFC.

• Korean Journal of Acupuncture
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• v.36 no.1
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• pp.44-51
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• 2019

Objectives : Teaching the standardized acupuncture point locations and improving the accuracy of acupoint locations through objective evaluation is a very important part of Korean medicine education. The aim of this study is to develop a dummy system for evaluation and support of teaching acupoint location in meridian and acupoints classes and to introduce the developed system. Methods : We established a protocol for the development of the system. The protocol included definition of usage purpose, definition of its essential performance, and set of scope. The system compares the amount of light at the target acupoint with the amount of light at the other sites to determine whether the target acupoint is properly specificated. Results : A prototype of the system was built according to the protocol and consists of light emitter, dummy, control/operation, input part and output part. The light emitter projects laser beam passing through the skin of the dummy. Light sensors were attached inside the acupoints of the dummy. Three types of light sensors were selected depending on the location of the acupoints. The arithmetic, input, and output parts were constructed using Arduino and Raspberry pi boards. The developed system was applied in class. Conclusions : It is thought that the dummy system for evaluation and support of teaching acupoint location can be used as a training model in order to help teach standardized acupoint locations and objective evaluation.

• Journal of the Korean Regional Science Association
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• v.9 no.1
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• pp.107-111
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• 1993