• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.8
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• pp.3660-3669
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• 2011

Demands for systemized management of workers' safety systemically in construction sites have been increased. Industrial accidents at work places are often happened by risk factors of construction sites, and also it brings a lot of loss as the correct direction for workers about locations to work is not delivered properly. In this paper, a safety supervision system for construction sites is designed and implemented to figure out the location of workers accurately and to provide the information about the status of works and workers in real-time by personal device which is based on RFID. The system designed in this paper achieved high performance in its function and efficiency through a performance test, compared with existing analogous systems.

• The Journal of the Acoustical Society of Korea
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• v.23 no.1
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• pp.1-7
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• 2004

We developed SH-SAW sensors to detect protein molecules in liquid solutions applying a particular antibody thin film on the delay line of transverse SAW devices. The antibody investigated was human-immune-globulin G (HigG) to hold the antigens (anti-HigG) in the protein solution. We fabricated the sensor generating 100 MHz with the piezoelectric single crystal LiTaO₃. We measured the frequency change of the sensor by adding the anti-body concentration on SAM (self assembled monolayer) deposited on the Au layer. The sensor showed stable response to the mass loading effects of the anti-HigG molecules with the sensitivity up to 10.8 ng/ml/Hz at noise level 400 Hz below.

• Journal of Korean Society for Geospatial Information Science
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• v.10 no.2 s.20
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• pp.67-75
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• 2002

Recently, GIS tend to be studied in water resoruces field. In hydrology analysis, GIS propose way that can develop subjective element of designer objectively. The development project is conducting disaster effect estimation to breed disaster, and cope these disaster beforehand provoking soil erosion and food recently. In this study, receive value of LS factor through DEM data at volume of soil erosion computation by disaster effect estimation and whether it are some relation effect of gradient and change of soil erosion by grid size did comparative analysis. As a result, according as grid size great, gradient became slow and could know that error value of gradient great according as storing scale of digital topographical map grows.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.2
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• pp.390-396
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• 2010

An 80MHz surface acoustic wave (SAW)-based gyroscope utilizing a progressive wave was developed on a piezoelectric substrate. The developed sensor consists of two SAW oscillators in which one is used for sensing element and has metallic dots in the cavity between input and output IDTs. The other is used for a reference element. Coupling of mode (COM) modeling was conducted to determine the optimal device parameters prior to fabrication. According to the simulation results, the device was fabricated and then measured on a rate table. When the device was subjected to an angular rotation, oscillation frequency differences between the two oscillators were observed because of the Coriolis force acting on the metallic dots. Depending on the angular rate, the difference of the oscillation frequency was modulated. The obtained sensitivity was approximately 52.35 Hz/deg.s within the angular rate range of 0~1000 deg/s. The performances of devices with three IDT structures for two kinds of piezoelectric substrates were characterized. Good thermal stability was also observed during the evaluation process.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.15 no.1
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• pp.103-109
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• 2004

In this paper, a new modeling methodology of thin film bulk acoustic resonator(TFBAR) is presented and the formulations of each lumped element in the model are also introduced. The new model is based upon the Mason model that is a reasonable model to explain the physical characteristics of unit TFBAR. After simplifying the modified Mason model with an additional dielectric loss term, the new model similar to Modified Butterworth-Van Dyke(MBVD) model is complete. The proposed model has three optimization variables which is half of the MBVD model. As a result, the curve fittings for the measured data are much faster and more accurate than any other conventional models. Moreover, it is very useful to design the bandpass filters or voltage controlled oscillators due to the design parameters, such as resonant and anti-resonant frequency, which can reflect the intentions of designer in the model.

• The Journal of Fisheries Business Administration
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• v.31 no.1
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• pp.135-151
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• 2000

최근에 지속적 발전(sustainable development)은 환경정책 분석뿐만 아니라 현대 환경, 생태 경제학에 있어서 중요한 개념이 되어왔으며, 이 개념은 어업에 있어서 특히 중요한 국제적 이슈(issue)가 되고 있다. 어업은 갱생자연 자원에 입각한 산업으로서 지속적 발전의 길로 가야만 한다. 이것은 1982년 UN해양법 협약(UNCLOS), 1995년 UN경계왕래성 어족과 고도회유성 어족에 관한 집행협약 (UNIA), FAO의 책임있는 어업(the Code of Conduct fer Responsible Fisheries)을 위 한 국제규범과 일련의 기술지침서에서 구체적으로 표현함으로써 국제적 합의가 이루어 지게 되었다. 지속적 발전의 개념에 대한 심층적인 이해는 어업 관리자가 어업정책의 수립과 평가에 대한 새로운 요소와 기준을 설정함에 있어서 중요한 의미를 부여한다. 이것은 특히, 어업관리자(정부와 단체 그리고 어업자)가 어업관리 목표 어종 및 비관리목표 어종과 어종의 생태, 그리고 환경을 포함한 어업 자원의 직접 사용 가치와 비사용 가치(즉, 내재 가치 )등에 관련된 제문제를 다루는 것을 그 내용으로 한다. 따라서, 이 논문은 국제사회에서 지속적 발전과 관련된 지식의 현 주소와 어업관리에 있어서 갖는 함축적 의미와 주로 관계된다. 이 논문은 지속적 발진에 대한 개념의 기원과 형성과정, 개념 구조를 상세히 고찰함으로써 어업의 지속적 발전을 위한 어업관리정책 수립을 위한 방향설정에 기여하게 될 것이다. 또 이 논문에서는 지속적 발전의 개념하에서 어업의 지속성과 지속적 발전이 어업관리에 어떠한 의미를 갖는지 고찰한다. 그 하나로 이 논문에서는 FAO에서 최근에 제시한 해양어업의 지속적 발전지표를 어떻게 설정하는지에 대한 가이드라인을 분석 고찰 하였다. 이 FAO의 지속적발전지표는 지속적 발전의 평가체계의 구성요소와 어업에 대한 지속적 평가체계[sustainable development reference system(SDRS)]를 수립하는데 있어서 필요한 관련 절차에 관해 특별한 의미를 부여해 줄 것으로 생각한다. 마지막으로 본 논문에서 는 SDRS가 지역어업 협력체계 구축에 있어 서 어떠한 역할을 할 것인가를 강조함으로써 결론을 내리고 있다.

• Pediatric Infection and Vaccine
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• v.20 no.2
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• pp.98-104
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• 2013

Dengue fever is an important health problem for international travelers to all endemic areas. The steadily increasing numbers of tourists visiting endemic areas raise the risk of exposure, and imported dengue cases are increasingly observed in nonendemic area. Dengue has a wide spectrum of clinical presentations, often with unpredictable clinical evolution and outcome. While most patients recover following a self-limiting, non-severe clinical course, a small proportion progress to severe disease such as dengue hemorrhagic fever or dengue shock syndrome. Therefore, it is important to suspect dengue fever in every febrile patient returning from the tropics. Whenever it is suspected, a quick diagnosis and adequate managements are essential to avoid complications. We report two cases of imported dengue fever in Korean children presenting with fever, headache, nausea, and rash.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.8A
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• pp.1252-1258
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• 1999

This paper describes a COMS IF transceiver IC for 10-MHz bandwidth wireless local loops. It interfaces between the RF section and the digital MODEM section and performs the IF-to-baseband (Rx) and baseband-to-IF (Tx) frequency conversions. The chip incorporates variable gain amplifiers, phase-locked loops, low pass filters, analog-to-digital and digital-to-analog converters. It has been implemented in a 0.6 -${\mu}{\textrm}{m}$ 2-poly 3-metal CMOS process. The phase-locked loops include voltage-controlled oscillators, dividers, phase detectors, and charge pumps on chip. The only external complonents are the filter and the varactor-tuned LC tank circuit. The chip size is 4 mm $\times$ 4 mm and the total supply current is about 57 mA at 3.3 V.

• Journal of IKEEE
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• v.3 no.2 s.5
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• pp.186-195
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• 1999

In this paper, the RF-modules composed of front-end, frequency synthesizer, modulator/demodulator and power control multi channel WLL personal system for W-CDMA using 10 [MHz] RF channel bandwidth has been implemented and considered. The measured transmission power is 250 [mW] which is very close to the required value. The measured flatness of power at the final output stage is ${\pm}1.5[dB]$ over the required bandwidth of the receiver. In addition, it is found that the chip rate transmitting spread signal is set to 8.192 [MHz], the required rate. The frequencies of RF_LO signal and LO signal of the modulator and the demodulator measured by a frequency synthesizer are satisfied with design requirements. The operating range of the receiving strength signal indicator and AGC units shows 60 [dB] respectively. Also the measured phasor diagram and eye pattern for deciding the RF modules compatible with baseband digital signal processing part are shown good results.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.48 no.9
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• pp.13-21
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• 2011

In this paper, the CMOS programmable interface circuit for MEMS gyroscope is presented, and evaluated with the MEMS sensing element. The circuit includes the front-end charge amplifier with 10 bit programmable capacitor arrays, 9 bit DAC for accurate offset calibration, and 10 bit PGA for accurate gain calibration. The self oscillation loop with automatic gain control operates properly. The offset error and gain error after calibration are measured to be 0.36 %FSO and 0.19 %FSO, respectively. The noise equivalent resolution and bias instability are measured to be 0.016 deg/sec and 0.012 deg/sec, respectively. The calibration capability of this circuit can reduce the variations of the output offset and gain, and this can enhance the manufacturability and can improve the yield.