• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.6
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• pp.43-49
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• 2015

This paper designs and implements a smart phone safe application program for advanced preventing a danger during a car driving with doing a smart phone. The proposed smart phone safe application program has the aim to increase easily and naturally the concentration when the driver is using of the smart phone during a car driving. Especially when sudden situation occurs, If driver gives up driving conditions, and go to the restaurant, move to tourist resort. It will continue to send the text of driving even if another person is on the phone. In this paper a traffic safety simulation was performed using a fuzzy inference rules in order to solve these problem. The simulation is predicted greatly to decrease to send the auto sending message when the driver gives up suddenly the driving because catching up whether the car is driving or not.

• The KIPS Transactions:PartC
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• v.9C no.5
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• pp.775-782
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• 2002

This paper introduces Policy Management Tool which was implemented based on Policy Information Model in network suity system. Network security system consists of policy terror managing and sending policies to keep a specific domain from attackers and policy clients detecting and responding intrusion by using policies that policy server sends. Policies exchanged between policy server and policy client are saved in database in the form of directory through LDAP by using Policy Management Tool based on network security policy information model. NSPIM is an extended policy information model of IETF's PCIM and PCIMe, which enables network administrator to describe network security policies. Policy Management Tool based on NSPIM provides not only policy management function but also editing function using reusable object, automatic generation function of object name and blocking policy, and other convenient functions to user.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2022.06a
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• pp.339-343
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• 2022

In this study, a method for simplifying the structure of the VDES RF receiver, and the gain control method of the receiver to comply with the international standard in this structure was described. The input level of the wanted signal and unwanted signal to the receiver was defined, and when the two signals were input, the saturation state at the ADC was checked at the receiver output. As a result of the simulation by the circuit simulator, it was satisfied that the output power of the receiver was in the SFDR region of ADC with respect to the adjacent channel interference ratio, intermodulation, and blocking level. Through this study, it was found that the structure of th proposed RF receiver conforms to the international standard.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 1999.04a
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• pp.9-14
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• 1999

1. LPG 온풍기는 용량 16$\times$$10^4$ ㎉ 건타입가스버너, 연소부 및 열교환부, 6개의 50kgLPG탱크와 자동절체기, 가스메타, 배관으로 구성하였다. LPG 온풍기의 이론연소효율은 91%, $CO_2$ 배출량은 11.74%, CO배출량은 0ppm, 과잉공기비는 1.16, 배기가스온도는 253$^{\circ}C$, 온풍온도는 8$0^{\circ}C$로서 우수한 성능으로 나타났다. 2. LPG온풍기에서 배출되는 배기가스중의 $CO_2$ 를 온실로 공급하기 위하여 $CO_2$ 공급기를 제작하여 배출가스연도에 부착하였다. $CO_2$ 공급기는 흡입형 시로코팬(1200㎥/h)과 차단문으로 이루어졌다. 1-2W형 300평 온실내의 $CO_2$ 농도를 1000ppm으로 올리기 위해서는 $CO_2$ 공급기를 약 1시간 정도 운전시켜야 할 것으로 판단되었다. 3. LPG온풍기와 경유온풍기의 경제성 비교분석에 의하면 현 시점의 경유 가격 242원, LP가스 가격 435원을 기준으로 연간소요비용은 각각 5,392,430원, 5,299,917원으로 경유온풍기가 10만원 정도 경제적이지만 탄산가스 시용비용, 탄산가스 공급으로 인한 작물의 수량증대 및 고품질 생산물을 고려한다면 LPG온풍기 사용이 더 경제적이라 사료된다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38A no.12
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• pp.991-997
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• 2013

A new frequency tuning scheme and a transconductor with a wide tuning range and low harmonic distortion is presented. This frequency tuning technique is based on the relationship between the time-constant and the elapsed times in charging a capacitor up to a certain level. Its structure is as simple as that of a conventional tuning scheme using a VCF(Voltage-Controlled Filter) and it does not need a pure sine wave but uses a CLK(Clock) pulse as a reference signal, which is easily obtained from on-chip system clocks or external X-tal oscillators. When a certain reference CLK is given, without complex capacitor arrays the pole frequency of the filter can be controlled continuously in the frequency domain. Simulation results are presented to confirm the operation of the proposed approach.

• The Transactions of the Korean Institute of Power Electronics
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• v.14 no.2
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• pp.134-141
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• 2009

The new method is proposed to improve the dynamics of the phase angle detector during abrupt voltage dip caused by a grid fault. Usually, LPF(low pass filter) is used in the feedback loop of SRF(Synchronous Reference Frame) - PLL (Phase Locked Loop) system because the measured grid voltage contains harmonic distortions and sensor noises. A better transient response can be obtained with the proposed design method for SRF-PLL by the analysis of linearized model of the PLL system including LPF. Furthermore, in the proposed method, the controller gain and LPF cut-off frequency are changed from normal value to transient value when the voltage disturbance is detected. This paper shows the feasibility and the usefulness of the proposed methods through the computer simulation and the experiment.

• Proceedings of the KIEE Conference
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• 2002.07a
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• pp.274-276
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• 2002

긴급보호제어시스템(SPS, Special Protection System)은 일반적인 보호동작 범위를 벗어난 외란에 대해서 계통 전지역의 보호를 목적으로 하는 광역시스템 보호기술이다. 따라서 SPS는 외란 시에 계통 장비의 보호보다는 계통을 보호함으로써 전력 공급능력 향상에 주안점을 두게 된다. SPS는 자주 동작하지 않고 평소에는 대기 상태로 있으며, 긴급한 동작이 요구되기 때문에 많은 경우에 그 동작이 미리 결정되어 있다. SPS는 입력변수나 전력계통에의 영향에 따라 분류할 수 있는데, 입력변수에 따라서는 계통 응답에 기초한 SPS와 사고에 기초한 SPS로 나눌 수 있다. 발전기 탈락, 부하 차단이 SPS의 주요 보호 동작이며 이 외에 가스터빈이나 양수발전기 기동, AGC 제어, HVDC 고속전력변환, 분로기기의 자동스위칭 등의 제어 동작이 있다. 우리나라의 경우에는 주로 동기탈조 방지를 위한 발전기 탈락의 동작을 하는 SPS가 설치, 운전되고 있다.

• Journal of Institute of Control, Robotics and Systems
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• v.13 no.7
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• pp.616-623
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• 2007

A dual micro gas sensor array was fabricated using nano sized $SnO_2$ thin films which had good sensitivities to CO and combustible gases, or $H_2S$ gas for air quality sensors in automobile. The already existed air quality sensor detects oxidizing gases and reducing gases, the air quality sensor(AQS), located near the fresh air inlet detected the harmful gases, the fresh air inlet door/ventilation flap was closed to reduce the amount of pollution entering the vehicle cabin through HVAC(heating, ventilating, and air conditioning) system. In this study, to make $SnO_2$ thin film AQS sensor, thin tin metal layer between 1000 and $2000{\AA}$ thick was oxidized between 600 and $800^{\circ}C$ by thermal oxidation. The gas sensing layers such as $SnO_2$, $SnO_2$(pt) and $SnO_2$(+CuO) were patterned by metal shadow mask for simple fabrication process on the silicon substrate. The micro gas sensors with $SnO_2$(+Pt) and $SnO_2$(CuO) showed good selectivity to CO gas among reducing gases and good sensitivity to $H_2S$ that is main component of bad odor, separately.

• The Bulletin of The Korean Astronomical Society
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• v.35 no.1
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• pp.45.2-45.2
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• 2010

한국천문연구원은 한국우주전파관측망(Korean VLBI Network, KVN)에서 시험 운영 중인 한일공동VLBI상관기(Korea-Japan VLBI Correlator, KJJVC)의 핵심인 VLBI상관 서브시스템(VLBI Correlation Subsystem, VCS)을 제어하기 위해 CCS(Correlation Control Software)를 개발하였다. CCS는 명령어의 문법 검사를 하고, VCS와 TCP/IP 소켓으로 통신하여 명령어와 응답(reply)을 주고받으며, VCS의 실시간 요청에 대응하여 입력 지연 파라미터(delay parameter)를 자동으로 전달하는 소프트웨어이다. CCS는 사용자의 명령어를 local UNX FIFO를 통하여, 명령줄(Command Line)로 전달받고, 이러한 명령어들의 조합을 쉘 스크립트로 묶는 형태로 구성 되어있다. 그러나, 이렇게 명령어의 조합을 직접 편집하여 구성할 때, 입력할 명령어나 지연 파라미터의 구성이 복잡해지면, 스크립트에 필요한 명령이 문법에 맞지 않게 사용되거나, 일부 명령어가 누락될 수 있는 위험이 있다. 이러한 오류를 차단하고 작업 효율을 높이기 위하여, 상관 처리의 전체 운용 및 제어를 통합적으로 할 수 있는 사용자 인터페이스가 필요하다. 이를 위하여 KJJVC의 운용 및 제어를 위한 GUI를 설계하고 제작하였다. 개발된 GUI는 Python 언어를 기반으로 하는 wxPython 패키지를 사용하였으며, 사용자(Operator)가 명령어 문법이나 순서를 확인할 필요 없이, 관측 정보와 관측국 정보, 기록 매체 정보만 가지고 손쉽게 명령어의 조합을 생성해 주며, 시스템 초기화와 각종 정보의 입력이 직관적으로 이루어질 수 있도록 해 준다. 본 연구에서는 개발된 GUI의 설계 및 개발 과정과 시험운영에 대해 소개한다.

• Journal of Korea Spatial Information System Society
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• v.7 no.3 s.15
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• pp.83-92
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• 2005

Telematics is a wireless data communication system that provides various information services for driver's the safety or entertainment, and it makes drivers possible to use those services in the moving space, as if he/she is at home or at office. As telecommunication technology develops and Telematics market grows larger, standard platform for the intelligent telematics is required. This paper describes the structure and module control design of the intelligent telematics that recognizes driver's needs and pushes customized services to the driver at real-time.