• Proceedings of the KIEE Conference
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• 2001.07d
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• pp.2228-2230
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• 2001

TCP/IP 프로토콜을 사용하여 서버와 클라이언트를 연결하고 서버는 무선랜을 이용하여 여러 개의 디바이스를 제어할 수 있는 분산제어시스템을 구현했다. 디바이스의 제어 명령과 모니터링을 하는 클라이언트는 LAN을 통하여 서버에 접속한 후 디바이스 제어 명령을 서버에 전달한다. 서버는 디바이스 제어 명령을 수신한 후 실제 데이터만을 골라내어 디바이스가 받아들일 수 있는 데이터 형식으로 변환하여 RF 모듈을 통해 디바이스에 전달한다. 서버로부터 데이터를 수신한 디바이스는 제어명령을 실행한 후 센서는 디바이스의 상태를 체크하여 RF모듈을 통하여 서버에 전달한다. 다시 서버는 디바이스의 상태를 클라이언트가 받아들일 수 있는 데이터형식으로 변환하여 전달하고 클라이언트는 서버로부터 데이터를 수신하여 디바이스의 상태를 모니터링 한다. 각각의 디바이스는 자신만의 마이크로 프로세서를 가짐으로서 서버로부터 간단한 명령을 받아 각 프로세서가 스스로 판단하고 동작을 하게 된다. 서버와의 연결이 끊어질 경우 마이크로프로세서에 마지막 들어온 제어명령의 상태를 유지한다. 이 논문은 인터넷을 이용한 무선장치의 제어할 수 있는 안정된 시스템의 구현방법을 제시하며 서로 다른 프로토콜을 연결시키기 위하여 데이터의 구조를 변환시키고 여러 개의 디바이스가 안정된 동작을 도록 하는 방법을 제안했다.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.17 no.4
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• pp.8-12
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• 2003

Characteristics of optical transceiver module in radio frequency(RF) band were investigated with TO-can packaged Fabry-Perot laser diode(FP-LD). R-L-C parameters for equivalent circuit model of the LD were extracted with an impedance analyzer. With this model, impedance matching to the packaged LD could be performed by eliminating inductive components of the leads in the package by using lumped chip capacitors that have opposite reactance, while it shows resonance dip in low frequency band. The resonance dip could be removed using lumped elements for impedance matching by shifting the resonance frequency to the region out of interest.

• The KIPS Transactions:PartA
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• v.10A no.3
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• pp.255-260
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• 2003

In recent, as a typical example of RFID, the contactless IC card is widely used in traffic, access control system and so forth. And its use becomes a general tendency more and more because of the development of RF technology and improvement of requirement for user convenience. This paper describes the hardware module to process embedded contactless protocol for implementation contactless IC card. And the hardware module consists of analog circuits and specific digital logic circuits. This paper also describes more effective design method of contactless IC card, which method separates into analog circuit parts, digital logic circuit part, and software parts according to the role of the design parts.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.818-819
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• 2015

PAL-XFEL 장치에 사용 할 고전압 펄스 모듈레이터 출력파워는 수 ${\mu}s$ 범위의 짧은 고전압(400 kV), 대전류(500 A) 펄스를 요구한다. 이러한 펄스파워를 얻기 위해서 PFN(Pulse Forming Network)에 에너지를 축적하고, 플라즈마 스위치인 싸이라트론을 통하여 에너지를 신속하게 클라이스트론 쪽으로 전달한다. 클라이스트론은 모듈레이터에서 공급하는 펄스 전원을 이용하여 RF를 증폭하는 대출력 고주파 증폭장치이다. 고전압 펄스 모듈레이터 제어기는 고속펄스 신호처리 모듈(Fast Pulse Signal Conditioning Module), PLC(Programmable Logic Controller)로 구성되어 있다. 고전압 펄스 모듈레이터에 사용하는 대용량 싸이라트론은 고전력을 스위칭 할 때 발생하는 스위칭 노이즈는 매우 크다. 이러한 노이즈는 모듈레이터의 출력 시그널인 빔 전압, 빔 전류, EOLC(End of Line Clipper) 전류, DC high voltage에 섞여 있으면서 신호 왜곡 및 제어장치의 고장을 유발시킨다. 이처럼 노이즈가 많이 포함되어 있는 아닐로그 신호를 깨끗한 신호(a clean signal)로 바꾸어주는 노이즈 필터링 장치인 고속펄스 신호처리 모듈을 제작하여 실험한 결과를 알아보고 모듈레이터 인터록 시스템인 PLC에서 Dynamic Interlock의 응답시간을 빠르게 하기위한 회로 수정에 대한 결과에 관하여 기술하고자 한다.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.1
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• pp.148-154
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• 2015

Reports show that global system for mobile communication (GSM) mobile phones, or two-generation (2G) mobile phones, could affect functions of pacemakers and implantable cardioverter defibrillators (ICDs). In this study, we evaluated the effects of radio frequency electromagnetic fields (RF-EMFs) emitted by wideband code division multiple access (WCDMA) mobile phones, which were third-generation (3G) mobile phones, on pacemakers and ICDs. Five pacemakers and three ICDs were subjected to in-vitro test using a ECG simulator. We used a WCDMA module (average power : 0.25 W, frequency band : 1950 MHz) instead of a real WCDMA mobile phone. To assess the effects of the WCDMA module on pacemakers and ICDs, each implantable device was placed in close proximity (within 3 mm) to the WCDMA module for 5 min. As a result, no effects were observed on the five pacemakers and three ICDs for the RF-EMFs emitted by the WCDMA module. Because WCDMA mobile phones have the higher frequency band (1800-2200 MHz) and lower power output (0.01-0.25 W) than GSM moboile phone, the RF-EMFs emitted by WCDMA mobile phones do not affect patients with pacemaker or ICD.

• Journal of the Korean Society for Precision Engineering
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• v.19 no.5
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• pp.159-167
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• 2002

In this paper. we present a new method for monitoring of ECU's self diagnostic signals of vehicle without wire. In order to measure the ECU's self diagnostic signals, the interfaced circuit is designed to communicate ECU and designed terminal according to the IOS, SAE regulation of communication protocol standard. Micro-processor 80C196KC is used for communicating ECU's self diagnositc signals and the results are sent to the wireless terminal and PC monitoring system. Wireless terminal is also developed by 80C196KC, LCD, RF module, and keypad. The command from the keypad is sent to ECU through RF module and the result show on the Graphic LCD in real time. Software on PC is developed to monitor the ECU's self diagnostic signals using the Visual C++ complier in which RS232 port is programmed by half duplex method. The algorithms for measuring the ECU's self diagnostic signals are verified to monitor both ECU and portable terminal state. At the same time, the information to fix the vehicle's problem can be shown on the developed software. The possibility for remote measurement of ECU self diagnostic signal is verified through the developed systems and algorithms.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1042-1045
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• 2003

In this paper, we present a new method for the monitoring of Electric Control Unit's(ECU) self-diagnostic and the sensor signals of vehicle through Web. In order to measure the ECU's self-diagnostic and sensor signals, the interfaced circuit is designed to communicate ECU and terminal according to the ISO, SAE regulation of communication protocol standard. Microprocessor 80C196KC is used for communicating ECU's self-diagnostic signals and the results are sent to the Embedded Linux System(ELS) through RF module. ELS is developed by SA1110, RF module, Embedded Linux. All commands related in ECU communication are executed through Web. The CGI program composed in web server is executed by user and will return sensor signals from ECU Software on Embedded Linux system is developed to monitor the ECU's sensor signals using the arm compiler tool chain in which RS232 port is programmed by half duplex method. The possibility for remote measurement of ECU sensor signal through Web is verified through the developed systems and algorithms.

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2003.11a
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• pp.205-207
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• 2003

In this paper, we propose novel, small and integrated microwave chip filter using high dielectric substrates. A variety of dielectric substrates can be selected for the specifications of products according to dielectric, Q-factors, temperature stability ect. This paper describes an application of the very high dielectric constant (K=133) substrate for design of a band pass filter to a 5.8GHz Transmitter/receiver(T/R) module.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2004.05b
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• pp.177-181
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• 2004

It is as research about embodiment of MAC algorithm that is point of wireless LAN technology that is radio skill that is receiving present head of a family footlights, and embodied MAC that is algorithm that control modem Rf and host interface to level that existent common use radio AP and send-receive of high speed are available that embody function that is presented to IEEE 802.11 specs using H/W and S/W. When embody actually, tested module that embody actually using module modem and RF part because test is impossible after have common use product. Also, module that embody actually designed, and is expected to be utilized in radio LAN system construction of high speed late considering CRC and FCS ewer on channel.

• Journal of Advanced Navigation Technology
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• v.28 no.2
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• pp.225-231
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• 2024

In this article, a new approach is presented to improve the unchangeable function of a ready-made millimeter-wave antenna system. By designing a metamaterial surface appropriate for the given geometry and fixed electrical characteristics of the device, the properties of the radiated fields of the RF product are changed to have directivity and higher antenna gain. Unlike other designs using periodic metamaterials for a single patch, an aperiodic metasurface is developed to handle two patches. For a higher received signal strength and a longer RF path in the 24 GHz-radio link, an aperiodic metasurface enhances the radiated fields by 10 dB.