• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 제38회 하계학술대회
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• pp.1110-1111
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• 2007

These days, the concerns about maintenance and repair of electric facilities for stable and reliable electric power supply are increasing day by day. Because, we can have enormous damages economically and socially from a problem of the facilities, no matter how it is a small one. Especially, electric facilities in our country had been built abruptly from 40 years ago, so it can be thought that here are great amount of old facilities that must be repaired or replaced with new one, and the number would be increased time by time. On this situation, many researchers are studying the efficient and reliable method of maintenance for electric facilities and the results are applied on the facilities gradually by growing interests of operators and managers of the facilities. In this paper, the IED(Intelligent Electronic Devices) for Diagnosis system of electric machines are described. It takes analog data from a sensing device and operates digital processor to get a optimum digital data for diagnosis system. Now, this device is applied on several high voltage substations to diagnose and maintain GIS. Brief schematic of total diagnosis system and the construction of the IED are included in this paper.

• 한국정보통신학회논문지
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• 제12권10호
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• pp.1787-1793
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• 2008

지문 인식 시스템은 지문인식 장치(fingerprint acquisition device)를 통하여 아날로그(analog) 지문으로부터 변환된 디지털(digital) 지문에서 특이점을 추출하고 추출한 특이점 들에 대한 정보를 데이터 베이스에 등록하는 오프라인(off-line) 처리와 사용자가 시스템에 접근 할 때 입력한 지문으로부터 특이점을 추출한 후 데이터베이스에 저장되어 있는 특이점들과 정합(matching)하여 사용자의 시스템 접근 여부를 결정하는 온라인(on-line) 처리로 이루어져 있다. 본 논문에서는 이진화된 지문 이미지를 효율적으로 처리하기 위한 자료 구조인 Union and Division을 제안하고, Union and Division을 이용하여 이진화와 잡음 제거, 그리고 특이점 추출 단계로 이루어진 특이점 추출 알고리즘을 제안한다.

• Smart Structures and Systems
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• 제6권5_6호
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• pp.661-673
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• 2010

This paper presents recent developments in an extremely compact, wireless impedance sensor node (the WID3, $\underline{W}$ireless $\underline{I}$mpedance $\underline{D}$evice) for use in high-frequency impedance-based structural health monitoring (SHM), sensor diagnostics and validation, and low-frequency (< ~1 kHz) vibration data acquisition. The WID3 is equipped with an impedance chip that can resolve measurements up to 100 kHz, a frequency range ideal for many SHM applications. An integrated set of multiplexers allows the end user to monitor seven piezoelectric sensors from a single sensor node. The WID3 combines on-board processing using a microcontroller, data storage using flash memory, wireless communications capabilities, and a series of internal and external triggering options into a single package to realize a truly comprehensive, self-contained wireless active-sensor node for SHM applications. Furthermore, we recently extended the capability of this device by implementing low-frequency analog-to-digital and digital-to-analog converters so that the same device can measure structural vibration data. The compact sensor node collects relatively low-frequency acceleration measurements to estimate natural frequencies and operational deflection shapes, as well as relatively high-frequency impedance measurements to detect structural damage. Experimental results with application to SHM, sensor diagnostics and low-frequency vibration data acquisition are presented.

• 정보보호학회논문지
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• 제20권5호
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• pp.49-57
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• 2010

오류 분석 공격은 암호용 디바이스가 동작하는 동안 오류를 주입한 후 그 결과를 분석함으로써 사용된 비밀키를 추출하는 물리적 공격 방법이다. 이러한 오류 분석 공격에 의해 표준 서명 알고리듬인 DSA(Digital Signature Algorithm)도 취약한 특성이 있음이 밝혀졌고 이를 방어하기 위한 대응책들도 제시된 바 있다. 본 논문에서는 오류 분석 공격을 방어할 수 있는 새로운 DSA 서명 기법을 제안한다. 제안 기법은 서명 연산시 한 번의 역수 연산만 추가 되므로 타 대응 방식에 비해 효율적으로 구현할 수 있다.

• 한국군사과학기술학회지
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• 제24권1호
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• pp.31-40
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• 2021

The multi-channel video streaming system is an essential device for future ground combat vehicles. For the system, the application of digital interfaces is required instead of the direct analog method to support selectable multiple channels. However, due to the characteristics of the digital interfaces that require en/decoding and signal conversion, the system should support the ability to adapt to quality and delay requirements depending on how video data is utilized. To support addressed issue, this study designs and emulates the multi-channel compressed-video streaming system of ground combat vehicle's fire control system based on commercial standards. Using the system, this study analyzes the quality of video according to the rotational speed of the acquisition device and Glass-to-Glass (G2G) delay between video acquisition and display devices according to video compression rates. Through these experiments and analysis, this paper presents the design direction of the system having scalability on the latest technology while providing high-quality video data streaming flexibly.

• 산업경영시스템학회지
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• 제44권1호
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• pp.51-59
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• 2021

Electronic document communication based on a digital channel is becoming increasingly important with the advent of the paperless age. The electronic document based on PDF format does not provide a powerful customer experience for a mobile device user despite replacing a paper document by providing the content integrity and the independence of various devices and software. On the other hand, the electronic document based on HTML5 format has weakness in the content integrity as there is no HTML5 specification for the content integrity despite its enhanced customer experience such as a responsive web technology for a mobile device user. In this paper, we design the Document-HTML, which provides the content integrity and the powerful customer experience by declaring the HTML5 constraint rules and the extended tags to contain the digital signature based on PKI. We analyze the existing electronic document that has been used in the major financial enterprise to develop a sample. We also verify the Document-HTML by experimenting with the sample of HTML electronic communication documents and analyze the PKI equation. The Document-HTML document can be used as an authorized electronic document communication and provide a powerful customer experience in the mobile environment between an enterprise and a user in the future.

• 디지털산업정보학회논문지
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• 제19권2호
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• pp.11-25
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• 2023

With the increasing advancement of VLSI technology, health care system is also developing to serve the humanity with better care. Therefore, biomedical implantable devices are one of the amazing important invention of scientist to collect data from the body cell for the diagnosis of diseases without any pain. This Biomedical implantable transceiver circuit has several important issues. Oscillator is one of them. For the design flexibility and complete transistor-based architecture ring oscillator is favorite to the oscillator circuit designer. This paper represents the design and analysis of the a 9-stage CMOS ring oscillator using cadence virtuoso tool in 180nm technology. It is also designed to generate the carrier signal of 403.5MHz frequency. Ring oscillator comprises of odd number of stages with a feedback circuit forming a closed loop. This circuit was designed with 9-stages of delay inverter and simulated for various parameters such as delay, phase noise or jitter and power consumption. The average power consumption for this oscillator is 9.32㎼ and average phase noise is only -86 dBc/Hz with the source voltage of 0.8827V.

• 전자공학회논문지
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• 제49권10호
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• pp.187-193
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• 2012

디지털 X-ray 영상 디텍터는 의료용 및 산업용으로 널리 이용되고 있다. 직접방식(direct method)의 디지털 X-ray 영상 디텍터는 X-ray 에너지를 전기적 신호로 변환하기 위하여 광도전체(photoconductor)를 이용하며 일반적으로 비정질 셀레늄(a-Se)을 사용하고 있다. 본 연구는 비정질 셀레늄 표면에 파장 486 nm의 전자방사선을 조사할 경우 내부에서 일어나는 물리적 현상들을 분석하기 위하여 2차원 소자 시뮬레이터을 이용하였다. 시뮬레이션 결과를 통해 비정질 셀레늄 내부 전자-정공 생성율, 전자-정공 재결합율, 전자/정공 분포에 대한 분석을 수행하였다. 사용된 시뮬레이터는 디바이스 내부를 삼각형으로 나누어 보간법을 사용하여 계산하는 방식이다. 본 시뮬레이션 방법은 직접방식 디지털 X-ray 영상 디텍터 분석을 위하여 처음으로 제안되었고 유용한 방법이다. 이러한 2차원 소자 시뮬레이터를 이용한 연구방법은 향후 디지털 방사선 영상 디텍터 개발에 많이 응용될 것으로 예상된다.

• 조명전기설비학회논문지
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• 제29권9호
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• pp.23-32
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• 2015

In order to complete engineering works of the digital substation, Both Data transmission among a variety of IEDs and HMIs, and single line diagram of the substation might be done based on XML documents published in IEC 61850 international standards. This kind of XML based engineering process for the digital substation must be implemented not by manual written work but by the engineering tool using a computer. But most of the engineering tools do not support system based engineering works such as single line diagram of the substation but have only function to set IEDs as single device unit. Accordingly, this paper presents a new design method of the system based engineering description applicable to real IEC 61850 based substation through analyzing the current international standard and its sampled engineering file, and shows implementation of the engineering tool of the digital substation with the result of this study.

• 정보보호학회논문지
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• 제26권2호
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• pp.345-358
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• 2016

이 논문에서는 디지털 인감이라는 보안 도구를 제안한다. 디지털 인감은 종이에 출력된 바코드를 스캔하고, 스캔한 바코드 데이터와 그 데이터에 대한 HMAC 태그를 디스플레이 장치에 출력한다. 생성된 HMAC 태그는 온라인 또는 오프라인에서 사용자 본인을 확인하거나 메시지의 인증에 사용될 수 있다. 우리는 디지털 인감을 온라인 뱅킹에 적용하여 보안카드나 OTP의 부족한 점을 보완할 수 있는지에 대해 검토한다. 또한 오프라인 차용증에 일반 인감대신 사용하여 인감의 위조 가능성을 낮출 수 있는지도 검토한다.