• Proceedings of the KIEE Conference
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• 2002.07b
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• pp.1184-1186
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• 2002

Recently, according to the industrial development relative to multimedia, demand of display system is radically increase, thus development for power supply of back-lighting is advanced lively. Fluorescent lamp operated at high frequency by the electronic ballast provide benefits like unnoticeable flicker effect and higher luminous efficiency. This paper presents analysis of Push-Pull type resonant inverter for CCFL drive for stable characteristic and life improvement of fluorescent lamp operated at high frequency. Also it has proposed design procedure of Current-Fed type resonant inverter. On the basis of equivalent circuit, component characteristic and suitable region of operation frequency from simulation using Matlab and Pspice is predicted. Suitability of applied equivalent model and validity of design process from the experimental results with CCFL inverter.

• Proceedings of the KIEE Conference
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• 1992.07b
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• pp.1123-1125
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• 1992

In this paper, a current fed type Push-Pull high frequency inverter which have used in the past, proposed self tunning circuit. Also, theoretical analysis introduced which use normalization, and a several characteristics or circuit is estimated. Further, a purposed control circuit based on self tunning system is confirmed to be performance by experiment.

• Proceedings of the KIEE Conference
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• 2000.07b
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• pp.653-655
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• 2000

A moving-coil-type linear oscillatory actuator(LOA) consists of the NdFeB permanent magnets with high specific energy as the stator. a coil-wrapped nonmagnetic hollow rectangular structure. LOA system have the push/pull effect caused by the unbalanced magnetic field. In order to eliminate the unbalanced thrust, we propose the control algorithm and construct the LOA driver. As a results, we obtain the balanced oscillating thrust.

• Proceedings of the KIPE Conference
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• 2008.10a
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• pp.103-105
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• 2008

DC-DC 컨버터, DC-AC (계통연계형)인버터, 입 출력 필터 등으로 구성된 연료전지용 PCS에서 DC-DC 컨버터가 전체 효율에 가장 많은 영향을 미친다고 할 수 있는데 본 논문에서는 Push-Pull 컨버터를 선정하여 손실에 관하여 해석하였다.

• The Journal of Korea Robotics Society
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• v.14 no.3
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• pp.221-227
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• 2019

This paper studies an effect of vibration on twisted string actuation inside conduit at high curvature angles. In our previous work. we have mentioned that twisted string actuators can be used to transmit power even at significant curvature angles of the conduit. However, several undesirable effects, namely pull-back, hysteresis, and chattering, were present during actuation due to friction between strings and the internal sheath of the conduit. This paper reports the results of experimental study on effects of vibration on twisted string actuation inside curved conduits. We have demonstrated that applying vibration generated near natural frequency of the system during the stages of twisting and untwisting cycles helped reduce pull-back and hysteresis and increase string contraction. In case when sheath was deflected by $180^{\circ}$ under a constant load of 3 kg, we were able to achieve over 40% decrease in pull-back and 30% decrease in hysteresis, compared with no vibration case.

• Proceedings of the Korean Society for Information Management Conference
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• 2005.08a
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• pp.107-115
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• 2005

디지털 정보환경 하에서는 이용자가 정보를 찾아오기 기다리기 보다는 이용자를 찾아가 수요를 창출하고, 이용자의 취향에 맞춘 정보제공이 필요하다. 본 연구에서는 연구장비정보의 효율적인 정보제공을 위해 푸시(push)와 풀(pull) 서비스를 통합한 맞춤정보 서비스 모델을 제시하고, RSS(Really Simple Syndication) 2.0과 Dublin Core Metadata Element Set 1.1을 참고하여 연구장비정보의 RSS-XML 메타데이터를 설계한 후, 풀(pull) 형태의 선택적 정보제공(SDI)시스템을 구현하여 이를 적용하였다.

• Journal of the Korea Society of Computer and Information
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• v.20 no.8
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• pp.85-92
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• 2015

Due to the advancements in the capabilities of smart devices and home networks, we are able to easily access multimedia contents stored in a home server. In this paper, we present a wireless media content sharing mechanism for home networks that utilizes UPnP-based DLNA technology. We also present a novel Peer-to-Peer content sharing system that is able to operate on the client as well as server. Our system supports multiple push/pull services simultaneously via a multi-thread technique, and our intuitive user interface facilitates ease of use. Future studies would explore the feasibility of implementing our system in a multi-hop environment or providing a community-wide service.

• Journal of Institute of Control, Robotics and Systems
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• v.21 no.12
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• pp.1130-1135
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• 2015

The bond pull test is the most widely used technique for the evaluation and control of wire bond quality. The wire being tested is pulled upward until the wire or bond to the die or substrate breaks. The inspector test strength of wire by manually and it takes around 3 minutes to perform the test. In this paper, we develop a 3D vision system to measure 3D position of wire. It gives 3D position data of wire to move a hook into wires. The 3D measurement method to use here is a confocal imaging system. The conventional confocal imaging system is a spot scanning method which has a high resolution and good illumination efficiency. However, a conventional confocal systems has a disadvantage to perform XY axis scanning in order to achieve 3D data in given FOV (Field of View) through spot scanning. We propose a method to improve a parallel mode confocal system using a micro-lens and pin-hole array to remove XY scan. 2D imaging system can detect 2D location of wire and it can reduce time to measure 3D position of wire. In the experimental results, the proposed system can measure 3D position of wire with reasonable accuracy.

• Proceedings of the Korean Geotechical Society Conference
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• 2006.03a
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• pp.744-751
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• 2006

In case of the Soil Nail System applied to a slope, effects of vibrations from blasting, earthquake and creep of long term behaviors cause reductions of adhesion between grout and soil-nail. There are some reports of nail's pull-out failure by those reasons. In this paper it is suggested that the Cone Nailing System is enable to diminish effects of vibrations and creep. In this study on Cone Nailing System, the cones are installed to each nail by 2m. By such installing cones, the adhesion between nail and grout will increase and the long term creep behavior will decrease. In this study, the centrifuge test is performed to understand the behaviors of the Cone Nail System. For the centrifuge test, the soil tank is 52cm in width, 17cm in length and 35cm in height. In comparison with general soil nail, the centrifuge test of general soil nail(without cone) is performed equally. Additionally, the interface between cone nail and soil through the pull-out test is applied to FLAC 2D version 3.3. and the evaluation of application for the Cone Nail System in slope is performed.

• Journal of KIISE
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• v.43 no.10
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• pp.1094-1103
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• 2016

Physical Web and Eddystone can be serviced by a single integrated application on the device by using their servers' URL. However, they have a limitation that their servers must be customized for service characteristics on a case by case basis. In other words, regardless of the service selected for BLE, it should have a modified linkage application for each device. Hence, we think that a new integrated service platform, which is able to link and support its Beacon from the central server and is also able to support its application, is needed for achieving better service quality. This platform consists of push (Broadcasting for Beacon service) parts and pull (Connection) parts to establish communication. Especially, Pull should be operated and controlled under the authorization (secure) management for safe and trustable communication. It means that BLE must have its new authorization communications protocol to protect its data as much as possible. In this paper, we propose a BLE integrated authorization protocol for a BLE device control server based on Physical Web and Eddystone.