• Journal of Information Technology Services
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• v.10 no.1
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• pp.105-116
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• 2011

With recent spotlight on the, uniquitous computing technology, the need for object of indentification and location infrastructure has increased. Such GPS technolgy must utilize IEEE 802.15.4 Zigbee used for existing wireless sensor network infra as a basice element for user's context-awareness in a uniquitous environement, for effectiveness.Such real-time GPS service is provided in the internal environment where the user would actually are and most high-rise buildlings apply. Underthe assumption, the real-time GPS technology is seperated by each floor, and signals do not get transmitted to other floors, the application on one floor within the high-rise buildling was conducted. This study intends to suggest a floor detection algorithm using IEE 802.15.3/Zigbee's RSSI which supports the accuracy within a couple of meters for the user's the movement between the floors in high-rise buildings in a complex environment. It proposes an floor detection algorithm using IEEE 802.15.4/Zigbee's RSSI which provides accuracy within a radius of few meters for the users movement between the floors for real-time location tracking within high-rise building in a cmoplex environment. Furthermore, for more accurate real-time location tracking, it suggests an algorithm for real-time location tracking using IEEE 802.15.4a/Zigbee's CSS technology based on triangulation. Based on the suggested algorithm, it designs a hybrid real-time location tracking service system in a high-rise buildling and test its functions.

• The Journal of the Korea Contents Association
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• v.22 no.4
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• pp.83-93
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• 2022

Research is underway to solve the traffic problem by using crowdsourcing, where drivers use their mobile devices to provide traffic information. If it is used for traffic event detection through crowdsourcing, the task of collecting related data is reduced, which lowers time cost and increases accuracy. In this paper, we propose a scheme to collect traffic-related data using crowdsourcing and to detect events affecting traffic through this. The proposed scheme uses machine learning algorithms for processing large amounts of data to determine the event type of the collected data. In addition, to find out the location where the event occurs, a keyword indicating the location is extracted from the collected data, and the administrative area of the keyword is returned. In this way, it is possible to resolve a location that is broadly defined in the existing location information or incorrect location information. Various performance evaluations are performed to prove the superiority and feasibility of the proposed scheme.

• Journal of Magnetics
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• v.19 no.1
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• pp.72-77
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• 2014

This paper proposes an indirect fault detection method for an onboard degaussing coil system, installed to reduce the underwater magnetic field from the ferromagnetic hull. The method utilizes underwater field signals measured at specific magnetic treatment facilities instead of using time-consuming numerical field solutions in a three-dimensional space. An equivalent magnetic charge model combined with a material sensitivity formula is adopted to predict fault coil locations. The purpose of the proposed method is to yield reliable data on the location and type of a coil breakdown even without information on individual degaussing coils, such as dimension, location and number of turns. Under several fault conditions, the method is tested with a model ship equipped with 20 degaussing coils.

• The KIPS Transactions:PartC
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• v.8C no.2
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• pp.141-154
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• 2001

MOBAS는 규칙적인 모듈로 구성되어 있어 확장이 용이하며, VLSI 구현 시 고집적화 할 수 있고, 각 모듈간에 동기를 맞추기 쉬울 뿐 아니라, 단일 종류의 칩으로 중앙 스위치 구조를 구성할 수 있다. Modified MOBAS(Multicast Output Buffered ATM Switch)는 MOBAS와 유사한 구조를 가지지만 스위치 모듈(SM : Switch Module)의 구조에서 차이를 보이며 적은 스위치소자(SWE : Switch Element)를 사용한다. 위성 통신에서 스위치의 크기뿐 아니라 고장감내 특성도 스위치를 디자인하는데 필요한 중요한 요소이다. 본 논문에서는 Modified MOBAS의 고장 특성을 분석하고 이에 적합한 Detection 기법 및 Location 기법을 제안하였다. 또한 스위치 모듈구조를 변형하여 Modified MOBAS에 비해 약간의 스위치 소자를 더 사용하지만 MOBAS에 비해서는 적은 스위치 소자를 사용할 뿐 아니라, MOBAS와 같이 단일 고장 하에서 성능의 저하가 거의 없다.

• Journal of Power Electronics
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• v.18 no.5
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• pp.1608-1617
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• 2018

The rapid and correct isolation of faulty submodules (SMs) is of great importance for improving the reliability of modular multilevel converters (MMCs). Therefore, a fast diagnosis method containing fault detection and fault location determination was presented in this paper. An improved incremental predictive model of arm current was proposed to detect failures, and the multi-step prediction method was used to eliminate the negative impact of disturbances. Moreover, a control method was proposed to strengthen the fault characteristics to rapidly locate faulty arms and faulty SMs by detecting the variation rate of the SM capacitor voltage. The proposed method can rapidly and easily locate faulty SMs under different load conditions without the need for additional sensors. The experimental results have validated the effectiveness of the proposed method by using a single-phase MMC with four SMs per arm.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1464-1467
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• 2005

In this research, we developed a system, which can find the location of vehicle when people park their cars in a big parking lot or large area. People can find their cars readily through this simple device and they can save their time and effort. This is the purpose of this research. Performing this, detection of electromagnetic wave's direction is needed and we used shielding effectiveness of electromagnetic waves for the method of it. An absolute coordinate indicates four directions (E, W, S, N) by using an electronic compass module, and it is needed for the localization. The device can check the received count of the electromagnetic waves coming from all other directions through the system, which is installed in the vehicle. The direction recorded the least received count would be the location of the parked vehicles. We can add on the function of this research by using the same frequency of cars alarm goods. Also, it is useful in the huge indoor parking lot.

• Proceedings of the KIEE Conference
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• 2000.11a
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• pp.136-138
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• 2000

This paper describes an efficient location detection algorithm for a partial discharge(PD) source in the transformer. The algorithm is previously proposed is not suitable for PD source detection because ultrasonic signal is diminished through the inner structure. In this paper, the proposal algorithm find PD source using geometry method and 3th sensor on the one side of transformer without diminution of ultrasonic signal. The proposed algorithm demonstrates the effectiveness and validity on model transformer.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2003.04a
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• pp.471-476
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• 2003

The presence of voids under pavements or behind tunnel linings results in their deterioration. To detect these voids effectively by non-destructive tests, a method using radar was proposed. In this research, not only the detection of shape of voids, but also the location of reinforcing bars by radar image analysis is investigated. The experiments and image processing were conducted to detect voids and to locate reinforcing bars in or under concrete pavements (or tunnel linings) with reinforcing bars. From the results, the fundamental algorithm for tracing the reinforcing bars and voids, improving the horizontal resolution of the object image and detecting shape of objects, was verified.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.1401-1406
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• 2007

There is growing interest in CBTC(Communication Based Train Control) system in accordance with the development of the communication technologies. The CBTC system, which adopts the moving block, has advantages such as headway and installation cost reduction compared with the existing system with fixed block. For the moving block system, it is required to locate the trains in real-time. Based on EPLRS(Enhanced Position Location Reporting System) technology, the train position can be provided only through the communication between radios. This paper introduces EPLRS based train detection method and verifies its effect by instance.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.7
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• pp.1047-1055
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• 2015

We proposes a method for improving the identification and tracking of the moving objects in intelligent video surveillance system. The proposed method consists of 3 parts: object detection, object recognition, and object tracking. First of all, we use a GMM(Gaussian Mixture Model) to eliminate the background, and extract the moving object. Next, we propose a labeling technique forrecognition of the moving object. and the method for identifying the recognized object by using the optical flow and EMD algorithm. Lastly, we proposes method to track the location of the identified moving object regions by using location information of moving objects and Kalman filter. Finally, we demonstrate the feasibility and applicability of the proposed algorithms through some experiments.