• Aerospace Engineering and Technology
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• v.4 no.2
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• pp.117-125
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• 2005

Generally, the inertial navigation and guidance unit uses AF(Analog-to-Frequency) converters which convert analog signals into frequency signals to enhance a measurement accuracy of gyroscope and accelerometer outputs. The confidence level of AF converter is guaranteed by a prudential decision of calibration procedure and a performance of periodic calibration test. In this paper, we focus on the synchronous charge balance type AF converter which has a separate positive or negative current input and its calibration method is described. The calibration tests are classified into the scale factor error calibration and the bias calibration. These tests are automatically performed by the calibration program.

• The KIPS Transactions:PartD
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• v.18D no.6
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• pp.443-450
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• 2011

Model-based Component development methodologies consider the whole system as an component and develop physical components through recursive decomposition and refinements of components in a top-down manner. We developed a model translator that can be used to formally verify interaction consistency among components, especially the interaction behavior between before- and after- refinements of components. This translator can be used to identify potential problems in the refinement process so that problems can be addressed from the early stage of development. This paper introduces our translation approach and the organization of the translator. The translator has been applied to two case studies to show its usefulness.

• Korean Journal of Optics and Photonics
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• v.29 no.3
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• pp.104-109
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• 2018

We explain the basic principle of transformation optics, and introduce several design techniques for transformation cavities that can maintain the characteristics of whispering gallery modes (WGMs) even if the cavity is strongly deformed from a circular shape. As a method of obtaining various transformation cavities under a specific conformal mapping, we suggest a method of parallel movement of the initial cavity domain, and a method of rotating the ellipse as a cavity domain. The internal wave pattern and the far-field output characteristics of several designed resonant modes are numerically calculated. From these results, it is confirmed that a variety of GRIN resonators are possible for a given conformal coordinate transformation.

• Journal of IKEEE
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• v.23 no.2
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• pp.636-641
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• 2019

A simple resistance deviation-to-time period converter is proposed for interfacing resistive half-bridge sensors. It consists of two 2nd generation current conveyors(CCIIs). The proposed converter has simpler circuit configuration than the conventional converters using operational amplifiers or operational transconductance amplifiers(OTAs). The proposed converter was simulated using CCII implemented with AD844 IC chips. The simulation results show that the converter has a conversion sensitivity of $0.01934ms/{\Omega}$ over a range of $100-500{\Omega}$ resistance deviations and a linearity error less than ${\pm}0.002%$.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.11
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• pp.1619-1626
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• 2021

Unlike traditional delta-sigma analog-to-digital converters, incremental analog-to-digital converters enable 1:1 mapping of input and output through a reset operation, which can be used very easily for multiplexing. Incremental analog-to-digital converters also allow for simpler digital filter designs compared to traditional delta-sigma converters. Therefore, starting with analysis in the time domain of the delayed integrator and non-delayed integrator, which are the basic blocks of analog-to-digital converter design, the design equations of a second-order input feed-forward, extended counting, 2+1 MASH (Multi-stAge-noise-SHaping), 2+2 MASH incremental analog-to-digital converter are derived in this paper. This allows not only prediction of the performance of the incremental analog-to-digital converter before design, but also the design of a digital filter suitable for each analog-to-digital converter. In addition, extended counting and MASH design techniques were proposed to improve the accuracy of analog-to-digital converters.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.10a
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• pp.520-521
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• 2017

The converted error is occurred by the time difference between the time interval signal and the clock in a Time-to-Digital Converter of counter-type. If the clock period is $T_{CLOCK}$ the converted error is a maximum $T_{CLOCK}$ by the time difference between the start signal and the clock. And the converted error is a maximum $-T_{CLOCK}$ by the time difference between the stop signal and the clock. However, when the clock is synchronized with the start signal and the colck is generated during the time interval signal the range of converted digital error is from 0 to $(1/2)T_{CLOCK}$.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.18 no.4
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• pp.509-518
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• 1993

Protocol conversion is to resolve the imcompatibility between networks so that users on different protocols can communicate with each other. This paper designs a formal model, EPN , to increase its modeling power and analyze conversion protocol and proposes a conversion algorithm using it. The conversion algorithm has two capabilities : synchronization and automatic error recovery function. Therefore burden of protocol converter design will be reduced, automatic protocol converter design can be possible and implementation for half-gateway will be easy.

• Proceedings of the Korean Information Science Society Conference
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• 2003.04d
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• pp.499-501
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• 2003

본 논문은 무선 인터넷 환경에서 사용자의 편의와 상호 운용성을 고려해서 유선상의 HTML 프레임 콘텐츠를 변환시키는 프레임 지원 HTML 변환기의 설계 및 구현에 대해 기술한다. 구현된 HTML 변환기는 일반 텍스트 콘텐츠의 경우, 일대일 태그 매핑을 통해 WML 콘텐츠로 변환이 된다. 프레임으로 구성된 콘텐츠는 프레임 콘텐츠 재구성 모듈에서 일련의 재구성 과정을 거친 후에 대부분의 프레임 콘텐츠가 여러 메뉴에 대해서 보여지는 타겟 프레임은 하나로 고정되어 있는 것을 고려해서 무선 단말기의 화면에 1행 2열의 테이블 형태의 WML 콘텐츠로 변환이 된다. 즉 좌측열에는 여러 메뉴 콘텐츠를 우측열에는 타겟 프레임에 보여지게 되는 콘텐츠를 위치 시킴으로해서 프레임 콘텐츠의 변환을 수행한다. 추가적으로 이미지 맵이 포함된 콘텐츠의 변환은 이미지 맵 관련 태그를 파싱한 후, 링크되어 있는 HTML 문서의 이름을 추출해서 WML 콘텐츠 데이터로 대체하고, 해당 콘텐츠로 링크시킴으로써 변환이 가능하게 한다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.2
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• pp.801-807
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• 2012

In this paper, design and implementation of frequency down converter based on LC filter technic. Single frequency down converter, designed a low-noise amplifier, mixer, IF amplifier, LC filter was configured. And it is composed of DC block capacitors and RF bypass capacitor. LC filter, replace it with the IC reduced the power and realized low cost. The gain of single down converter is about 10dBm and realized by 18MHz bandwidth at 70MHz band.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.15 no.8
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• pp.678-688
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• 1990

In this paper, pSDF-based referance image is realized. Using BJTC(binary joint transform correlator) as the spatial plane correlator, optical pattern recognition for intraclass indentification is performed. Computer simulation shows that the correlation performance of BJTC is superior to that of JTC. Experimental results using BJTC reveal that correlation peak intensity is constant within the error range from 4.1% to 9.6% in intraclass indentification.