• Journal of Institute of Control, Robotics and Systems
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• v.12 no.1
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• pp.60-65
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• 2006

Recently, various ubiquitous networking services are developed and implemented for easy living. In general, new ubiquitous networking services require the new infrastructure including equipments and devices. However, it is difficult to replace existing infrastructure and devices with new ones in the home or office because of cost and maintenance problems. In this paper, we developed small-size web based RF wireless communication systems for sensor network applications. The designed RF systems are implemented using commercial system on a chip (SoC) on existing infrastructure and devices. The developed systems are tested for light control and temperature sensing and they are applied to sensor network training courses for students and engineer as well as various practical applications.

• Journal of IKEEE
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• v.19 no.2
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• pp.232-236
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• 2015

Super-junction trench MOSFET (SJ TMOSFET) devices are well known for lower specific on-resistance and high breakdown voltage (BV). For a conventional power MOSFET (metal-oxide semiconductor field-effect transistor) such as trench double-diffused MOSFET (TDMOSFET), there is a tradeoff relationship between specific on-state resistance and breakdown voltage. In order to overcome the tradeoff relationship, a SJ TMOSFET structure is suggested, but sensing the temperature distribution of TMOSFET is very important in the application since heat is generated in the junction area affecting TMOSFET. In this paper, analyzing the temperature characteristics for different number bonding for SJ TMOSFET with an embedded temperature sensor is carried out after designing the diode temperature sensor at the surface of SJ TMOSFET for the class of 100 V and 100 A for a BLDC motor.

• Proceedings of the KSRS Conference
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• 2009.03a
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• pp.78-81
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• 2009

레일형 GB-SAR의 단점을 극복하고자 차량에 원형레일을 탑재하여 신속한 기동을 확보하고 합성구경의 길이를 늘리며 영상영역을 확장한 ArcSAR를 세계 최초로 설계하고 시작품을 제작하였다. ArcSAR의 핵심기술이라고 할 수 있는 원형레일은 알루미늄 프로파일로 제작한 회전디스크, 곡선가이드, 리니어 가이드로 구성되며, 서보모터를 이용하여 구동된다. 회전디스크의 지름은 2.1 m 이며, 회전 디스크 위에 장착된 곡선 가이드를 따라 안테나가 탑재된 리니어 가이드가 이동하며 정밀한 원형 운행을 하게 된다. 리니어 가이드는 슬라이드식으로 제작되어 최대 3 m 까지 확장이 가능하여 스폿 모드 측정시 6 m 길이의 레일에서의 자료 획득과 유사한 결과를 얻게 된다. SAR 측정 장비는 회전디스크 위에 장착되어 전원을 제외한 별도의 슬립링을 사용을 자제하였다. 레일의 구동과 자료의 획득은 LabVIEW 기반의 통합 제어측정 소프트웨어를 통해 구현하였으며, 실내 실험 및 현장적용 실험을 통해 가능성을 확인하였다.

• Proceedings of the KIPE Conference
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• 2001.07a
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• pp.42-45
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• 2001

Switched Reluctance Motors(SRM) are a promising candidated automotive drives of the next generations. The successful commercialization of SRM drives in automobiles depends highly on the developments of SRM design and control techniques. This paper descrives the control issues of SRMs, ranging from drive system structure, rotor position sensing and torque control. Both simulation studies and test results are presented for a 160W SRM drive for automotive application.

• Journal of the Korea Institute of Military Science and Technology
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• v.14 no.6
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• pp.1037-1042
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• 2011

Since J.B.Pendry proposed the concept of "perfect lens" there have been many researches which focus electric fields. However they used 1 dimensional lens. In contrast, this paper suggests 2 dimensional lens calculated from angular-spectrum method. 2-dimensional focusing is achieved in nearfield. This result implies that the proposed lens can be used for wireless power transfer, imaging system, and sensing systems.

• Proceedings of the KSRS Conference
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• 2002.10a
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• pp.832-837
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• 2002

As diverse researches are working about location acquisition, storing method, data modeling and query processing of moving objects, the moving object database systems, which can gain, store and manage location information and query processing, are tuning up. As the mobile device is moving but have constraints, the convenience user interface for spatio-temporal query and viewing query result needs. In this paper, we designed user Interface for spatio-temporal query related moving objects, viewing query result, tracing current and past location of those and monitoring. And we designed system for implementation of these interfaces.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.1118-1120
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• 2003

In MSC(Multi-spectral camera ), the incoming light is converted to electronic analog signals by the CCD(charge coupled device) detectors. The analog signals are amplified, biased and converted into digital signals (pixel data stream) in the FPE(Focal plane electronics ). The digital data is transmitted to the PMU for pre-processing to correct for nonuniformity, to partially reorder the pixel stream and to add header data for identification and synchronization In this paper, the video data streams is described in terms of hardware.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.600-602
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• 2003

In Korea, fire is the second frequent disaster. A total of 32,966 fires were happened in 2002, and injured 2,235 people and damaged 12 million dollars. So, we developed several components related to fire in order to decrease these victims and the amount of damage and have applied those components to Daegu Fire Agency. In this paper, we describe the developing system. It consists of 5 major components: mobile fire facility management component, web service component, fire management component, fire server, and fire application. They were developed in object-oriented computing environment, ATL/COM and Visual C++. So, they have some advantages such as high reusability, full interoperability, and easy understanding.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.219-221
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• 2003

With regarding to web GIS, OGC promotes WFS allowing a client to retrieve geospatial data encoded in GML which is a modeling language to encode the semantics, syntax and schema of geospatial information resources. Even though GML provides benefits for geographic description, it is too heavy to be processed by mobile devices. In order to address the issue, this paper evaluates GML service with WFS server and GML viewers. Through this paper, we get analyses of properties of GML geospatial data and the effects on wireless devices, which are expected to be fundamental materials onto a design of mobile applications.

• Proceedings of the KIEE Conference
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• 1995.07a
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• pp.294-296
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• 1995

In this paper, a vector control method for a AC-Excited BLSM(Brushless Synchronous Motor) is proposed. The BLSM has a feature that separate exciter is not needed for excitation. The proposed method is described in two parts as follow, one is the design of drive and the other is a modeling for its implementation. Rotor flux is estimated using indirect sensing method based on voltage equation in the synchronously rotation reference frame. And rotor position is calculated from rotor angular velocity and stator current. Through computer simulation results of this proposed system, it is shown that the BLSM drive has a ability of precision torque control from the static and dynamic performance.