• International Journal of Control, Automation, and Systems
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• v.6 no.6
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• pp.828-835
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• 2008

We present a novel method for eye location by means of a two-level classifier scheme. Locating the eye by machine-inspection of an image or video is an important problem for Computer Vision and is of particular value to applications in biomedical imaging. Our method aims to overcome the significant challenge of an eye-location that is able to maintain high accuracy by disregarding highly variable changes in the environment. A first level of computational analysis processes this image context. This is followed by object detection by means of a two-class discrimination classifier(second algorithmic level).We have tested our eye location system using FERET and BioID database. We compare the performance of two-level classifier with that of non-level classifier, and found it's better performance.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.05a
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• pp.114-116
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• 2012

According to common use of smart mobile devices, various services based on the location become to appear. Futhermore, as the number of social media users using the mobile devices grows rapidly, the needs for Social Media services based on location also increase. With proposing the method to access and analysis the location-based social media database by standard SNS API, this thesis introduces technical methods to generate and the information which users want to get and to service them by mobile in real time.

• Journal of Korean Institute of Industrial Engineers
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• v.34 no.2
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• pp.160-171
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• 2008

MU's mobility patterns can be found from a movement history data. The prediction accuracy and model complexity depend on the degree of application of history data. The more data we use, the more accurate the prediction is. As a result, the location management cost is reduced, but complexity of the model increases. In this paper, we classify MU's mobility patterns into four types. For each type, we find the respective optimal number of application of history data, and predictive location area by using the simulation. The optimal numbers of four types are shown to be different. When we use more than three application of history data, the simulation time and data storage are shown to increase very steeply.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2007.11a
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• pp.388-394
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• 2007

In wireless network, we propose a predictive location update scheme which considers mobile user's(MU's) mobility patterns. MU's mobility patterns can be found from a movement history data. The prediction accuracy and model complexity depend on the degree of application of history data. The more data we use, the more accurate the prediction is. As a result, the location management cost is reduced, but complexity of the model increases. In this paper, we classify MU's mobility patterns into four types. For each type, we find the respective optimal number of application of history data, and predictive location area by using the simulation. The optimal numbers of four types are shown to be different. When we use more than three application of history data, the simulation time and data storage are shown to increase very steeply.

• Journal of Positioning, Navigation, and Timing
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• v.9 no.3
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• pp.169-173
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• 2020

Location-based services are used as core services in various fields. In particular, in the field of public services such as emergency rescue, accurate location estimation technology is very important. Recently, the technology of tracking the location of self-isolation subjects for COVID-19 has become a major issue. Therefore, location estimation technology using personal smart devices is being studied in various ways, and the most widely used method is to use GPS. Other representative methods are using Wi-Fi, Pedestrian Dead Reckoning (PDR), Bluetooth Low Energy (BLE) beacons, and LTE signals. In this paper, we introduced a positioning technology using deep learning based on LTE Channel State Information-Reference Signal (CSI-RS) data, and confirmed the possibility through an outdoor location estimation experiment using a commercial LTE signal.

• Proceedings of the Korean Society of Computer Information Conference
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• 2017.01a
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• pp.241-243
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• 2017

이동 단말기에서 실시간 데이터 제공을 위하여 대부분의 객체 위치 추적 시스템은 GPS 기반의 추적 기법을 사용하고 있으나, 본 논문에서는 위치 트리거 모델을 제안하여 객체의 이동 위치에 따른 시점과 위치 특성과 같은 지능적 정보를 통한 효율적 저비용의 위치 추적 기법을 제시한다. 본 논문에서 제안하는 위치 트리거 모델은 객체 정보의 흐름에 대한 실시간 모니터링과 예외상황 발생 시 지능화된 경고/조치, 최적화된 이동 경로 수립 및 계획의 동적/지능적 재조정을 위한 객체추적 및 이동의 최적화를 목표로 하는 시스템을 구성하기 위해 사용될 수 있다.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.14 no.2
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• pp.95-104
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• 2004

Leaks in underground pipelines can cause social, environmental and economical problems. One of relevant countermeasures against leaks is to find and repair of leak points of the pipes. Leak noise is a good source to identify the location of leak points of the pipelines. Although there have been several methods to detect the leak location with leak noise, such as listening rods, hydrophones or ground microphones, they have not been so efficient tools. In this paper, accelermeters aroused to detect leak locations which could provide an easier and more efficient method. Filtering, signal processing and algorithm of raw input data from sensors for the detection of leak location are described. A 120m-long and a 70m-long experimental pipeline systems are installed and the results with the systems show that the algorithm with the accelerometers offers accurate pinpointing for leaks location detection. Theoretical analysis of sound wave propagation speed of water in underground pipes, which is critically important in leak locating, is also described.

• Journal of Institute of Control, Robotics and Systems
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• v.18 no.1
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• pp.47-53
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• 2012

In cellular geo-location systems, positioning performance is influenced by hearability of receivers. Hearability can be enhanced by using long integration at the receiver. When unknown residual frequency remains in baseband signals, however, the coherent integration loss increases as the residual frequency becomes larger. Consequently, length of coherent integration is determined by the residual frequency. By precise estimation and compensation of the residual frequency, integration length can be enlarged. This paper presents a residual frequency estimator for WiBro geo-location and analyzes its performance in multipath environment. By computer simulation, an optimal receiver structure to enhance the hearability of WiBro geo-location is proposed.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.2
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• pp.252-255
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• 2008

A study for discharge pattern analysis partial and fault location by use of UHF sensors in GIS. However, in the latter case, the results considered the velocity of EM waves modified by the waveguide characteristics of GIS bus bar were not reported yet. In this paper, UHF wide band sensor to detect partial discharge signals have been designed and manufactured to get the widest band characteristic by an application of Fat-Dipole UHF antenna and the result that the transmission velocity of EM waves is 2/3 of the light have been got through the consideration of waveguide characteristics. Also, to verify applicability on site of the developed method, self-designed external type UHF sensor have been installed on operating GIS in Korea Midland Power co. and detected location of the fault. Through the fault have been found at the location, the reliability of the developed method have been proved.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.53 no.3
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• pp.168-174
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• 2004

This paper describes a new fault location algorithm based on the voltage equation at the relaying point using 6-phase current for untransposed 765㎸ parallel transmission lines. The proposed method uses the voltage and current collected at only the local end. By means of 3-phase circuit analysis theory to compensate the mutual coupling effects between parallel lines, the fault location is derived. The fault distance is determined by solving the 2nd distance equation based on KVL(Kirchhoff's Voltage Law). Extensive simulation results using EMTP(Electromagnatic Transients Program) have verified that the error of the fault location achieved is up to 4.56(%) in untransposed parallel transmission lines.