• Journal of Information Technology Applications and Management
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• v.14 no.4
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• pp.1-16
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• 2007

In the microcell- or picocell-based system the frequent movements of the mobile bring about excessive traffics into the networks. A mobile location estimation mechanism can facilitate both efficient resource allocation and better QoS provisioning through handoff optimization. Existing location estimation schemes consider only LOS model and have poor performance in presence of multi-path and shadowing. In this paper we study a novel scheme which can increase estimation accuracy by considering NLOS environment and other multiple decision parameters than the received signal strength.

• Journal of Power Electronics
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• v.19 no.3
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• pp.691-701
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• 2019

To solve the problems in the contact charging of inspection robots, a wireless charging system for inspection robots and a control strategy are introduced in this paper. Circuit models of a wireless power system with a compound compensation circuit and a three-phase Class-D resonant inverter are set up based on circuit theory. An output voltage control method based on the equal spread regulation of the phase difference between adjacent phases and the parameter correction method in the primary compound compensation circuit are proposed. The dynamic characteristics of the key parameters varying with the secondary coil position are obtained to further investigate the adaptive location scheme during the access and exit processes of moving robots. Combining the output voltage control method and the adaptive location scheme, a transition control strategy for the standby and operation modes of the wireless charging systems for inspection robots is put forward to realize the system characteristics including the low standby power in the standby mode and the high receiving power in the operation mode. Finally, experiments are designed and conducted to verify the correctness of the theoretical research.

• Journal of Information Processing Systems
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• v.15 no.5
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• pp.1218-1230
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• 2019

This study proposes a novel video traffic flow detection method based on machine vision technology. The three-frame difference method, which is one kind of a motion evaluation method, is used to establish initial background image, and then a statistical scoring strategy is chosen to update background image in real time. Finally, the background difference method is used for detecting the moving objects. Meanwhile, a simple but effective shadow elimination method is introduced to improve the accuracy of the detection for moving objects. Furthermore, the study also proposes a vehicle matching and tracking strategy by combining characteristics, such as vehicle's location information, color information and fractal dimension information. Experimental results show that this detection method could quickly and effectively detect various traffic flow parameters, laying a solid foundation for enhancing the degree of automation for traffic management.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.340-341
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• 2011

본 논문은 수도권 전압안정도 향상을 위해 사용될 Synchro-Phasor에 대하여 그 최적 설치위치에 관하여 다루었다. 특히 WAMAC(Wide Area Monitoring And Control system)시스템 구축을 위해 국내 계통 전체 감시목적과 수도권 전압 안정도 향상이라는 두 가지 측면에서 최적 PMU 설치 위치에 대해 검토하고 그 안을 제시하였다.

• Journal of Information Technology Applications and Management
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• v.13 no.3
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• pp.59-74
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• 2006

According to developing Wireless Communication, not only a location based service at the outside but also a location based service at the inside was more increased socially. This paper proposes the efficient algorithm to locate a transfer object in frequent change of indoor environment using indoor location tracking system we develop ourself. Proposing algorithm in this paper can locate a transfer object using the Fingerprint, one of the Location Tracking techniques which are used in general to minimize error data between Location Tracking System and Fingerprint, using this way that corrects location data as KF apply to result data can improve accuracy of a transfer object. At last we are going to compare and analyze existing typical triangulation with proposed Indoor location tracking system to demonstrate algorithm efficiency for proposed Indoor location tracking system.

• Spatial Information Research
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• v.11 no.2
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• pp.131-142
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• 2003

The Location Based Services comprised GIS and Telecommunication allow users to receive various services based on their geographic location. It is need to legislation to encourage the provision and use of location information by providing privacy protection to users. But the contents of the legislation proposed by Korean government have problems conflicted between protection of a person's location information and invigoration of location-based services. The purpose of this study is to search complementary measures for privacy protection of location information from a viewpoint of effective management strategy for geographic information.

• Smart Structures and Systems
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• v.1 no.2
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• pp.121-140
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• 2005

This paper presents a systematic investigation of the effect of sensor location on the data quality and subsequently, on the effectiveness of machine health monitoring. Based on an analysis of the signal propagation process from the defect location to the sensor, numerical simulations using finite element modeling were conducted on a bearing test bed to determine the signal strength at several representative sensor locations. The results showed that placing sensors closely to the machine component being monitored is critical to achieving high signal-to-noise ratio, thus improving the data quality. Using millimeter-sized piezoceramic plates, the obtained results were evaluated experimentally. A comparison with a set of commercial vibration sensors verified the developed structural dynamics-based sensor placement strategy. It further demonstrated that the proposed shock wave-based sensing technique provided an effective alternative to vibration measurement, while requiring less space for sensor installation.

• The KIPS Transactions:PartC
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• v.11C no.3
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• pp.387-394
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• 2004

One of the main challenges in personal communication services(PCS ) Is to locate many mobile terminals that nay move from place to place frequently. This kind of system operation is called location management. This task entails sophisticated signaling traffic and database queries. Several strategies have been proposed to improve the efficiency of location management. These strategies use location register databases to store the current locations of mobile terminals, and are vulnerable to failure of the location register databases. In this paper, we propose a fault-tolerant pointer forwarding scheme with distributed home location register in order to tolerate the failure of location registers. The performance of the proposed scheme is evaluated analytically by simulation, and Is compared with Biaz's bypass forwarding strategy and two-path forwarding strategy.

• Journal of the Korean Dietetic Association
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• v.13 no.3
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• pp.277-294
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• 2007

The purposes of this study were to a) examine using status, b) measure the service quality attributes, c) analyze IPA and customer satisfaction, d) develop the LSM(Local Store Marketing) by location of K theme restaurant such as residential type(A), complex type(B) and downtown type(C). The questionnaires were handed out to 346 of 450(usage rate 76.9%). The statistical data analysis was completed using SPSS(ver 12.0) for descriptive analysis, $X^2$, t-test, ANOVA, reliability analysis, factor analysis, multiple linear regression. From an analysis on service quality attributes, most importance of service quality attributes was more highly perceived than performance of those, except for 'attractive exterior', 'variety of kid's menu', 'convenient facilities for kid' and perceived importance and performance were also significantly different by location of branch restaurant. The attributes to be improved were 'convenience of restaurant's parking lot', 'food tast', 'speedy service' and 'service competency' as branch A(residential type) restaurant, 'convenience of the restaurant location' as branch B(complex type) restaurant and 'convenience of the restaurant location' and 'speedy service' as branch C(downtown type) through IPA analysis. The Overall customer satisfaction was 3.74 and service quality factors had significant effect on overall customer satisfaction. Location of restaurant, which gives a great effect on its operation and marketing, has a important correlation with success or failure of restaurant business enterprises. Therefore, marketing strategy by restaurant location should be developed.

• Journal of Industrial Technology
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• v.26 no.B
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• pp.191-198
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• 2006

In this paper, we focus on a question. Which is better between time-based location update method and movement-based location update method? Or, does any other method combining the two methods show better performance? For the question, we propose a hybrid location update scheme, which integrates the time-based and the movement-based methods. In the proposed scheme, a mobile terminal updates its location after n cell boundary crossing and a time interval of T, or the inverse. We derive an analytical solution for the performance of the hybrid scheme with exponential cell resident time. From the numerical analysis, we conclude that the movement-based method seems to have better performance than the time-based and hybrid methods, that is the optimal costs occur at T=0.