• 한국대기환경학회지
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• 제16권5호
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• pp.477-485
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• 2000

The data set was collected on fifty-eight different days with a 24-h sampling period from October 27, 1995 through August 25, 1996. From the chemical mass balance (CMB) analysis of $PM_{2.5}$ in the Chongju area, the contributions from soil, gasoline, diesel, light and heavy oil combustion were 2.6%, 15.4%, 9.0%, 28.8% and 1.5%, respectively. Residual $NO_{3}^{-}$), residual $SO_{4}^{2-}$ and residual OC, possibly formed in the atmosphere. represented additional 8.0, 10.2, and 1.6% of the $PM_{2.5}$, respectively. Other unidentified sources constituted the remaining 22.9%. From the CMB analysis, the $PM_{2.5}$ source contribution for fall, winter, spring and summer were 92, 76.8, 77.5 and 59.2%, respectively.

• 한국대기환경학회지
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• 제13권4호
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• pp.307-317
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• 1997

Samples of fine particle $(d_P<2.5 \mum)$ were taken in Chongju area using a dichotomous sampler. The data set was collected on fifty-eight different days with 24 hour sampling period from October 27, 1995 through August 25, 1996. The samples were analyzed using a proton induced x-ray emission (PIXE) for Na, Mg, Al, Si, S, Cl, K, Ca, Ti, V, Cr, M, Fe, Ni, Cu, Zn, Br and Pb. Values of Fe, Ca, Si, Cu, K and Cl exhibit marked seasonal variations. Mean concentrations for this study had the following order S > Cl > Si > K > Al > Fe on fine particle. Concentrations of Ca, Si and Fe were higher during the spring season compared with any other season. These phenomena may be attributable to soil dust. Cl and K were higher in the winter, which may be explained by combustion of fossil fuel. Higher values for Cu and Zn in the Winter may be due to the combustion and incineration.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2003년도 춘계학술발표논문집 (중)
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• pp.1477-1480
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• 2003

본 논문에서는 실시간 데이터 및 보안데이터, 영상데이터 통을 전송할 때 잡음으로 인해 발생되는 데이터 오류를 효과적으로 복원하기 위해 오류 정정 능력이 뛰어난 터보코드를 적응하여 신뢰성 있는 영상전송 시스템을 실현하였다. 영상처리 시스템에서는 CCTV, 비디오 카메라 등에서 나오는 NTSC(National Television System Committee) 영상 신호를 비디오 디코더를 통해 A/D 변환하여 출력하였다. 변환된 디지털 영상정보는 두 개의 영상필드로 출력되며 그중 하나의 필드가 선택되는 알고리즘을 EPLD(Erasable Programmable Logic Device) 로직회로로 구성하여 디지털 영상 데이터를 절반으로 줄이는 시스템을 구현하였다. 터보코드의 부호기, 복호기 시스템에서는 실수연산이 가능한 DSP(Digital Signal Processor)를 사용하여 터보코드를 구현하였으며, 터보코드의 성능을 좌우하는 인터리버부분은 블록 인터리버를 적용하여 설계하였다.

• Elastomers and Composites
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• 제31권1호
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• pp.13-22
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• 1996

In order to Improve the fracture toughness of epoxy resin system, liquid chloroprene rubber(LCR) and liquid butadiene rubber (LBR) which have hydroxy group were used in the brittle epoxy system. Mechanical and toughness characterization of the modified epoxy resins were investigated as a function of liquid rubbers content. Epoxy resins modified with both of the liquid rubbers showed complete phase-separation microstructure : In all of the LCR content, it was observed that the domain size of LCR dispersed in the epoxy matrix ranging from $2{\mu}m\;to\;5{\mu}m$. It was found that fracture toughness, $K_{ic}$, of the modified LCR system was enhanced continuously as increasing LCR content. However around 10phr of LBR system showed maximum fracture toughness. Specifically, when BPA add to the modified LCR system, thermal and mechanical properties increased than neat epoxy. At the same time, fracture toughness was enhanced.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 합동 추계학술대회 논문집 정보 및 제어부문
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• pp.184-186
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• 2001

This paper describes a method of human sensibility evaluation for pleasant and unpleasant environments. Conditions of the environment are room temperature and humidity. Changing the conditions, 10-channel EEG signals for 4 subjects are collected. Linear predictor coefficients of the recorded EEGs are extracted as the feature parameter of human sensibility. A neural network-based human sensibility estimation algorithm is developed. The developed algorithm showed good performance in the pleasantness evaluation. The neural network output produced accurate states of pleasantness sensibility. Subject-independent test showed similar results with subject-dependent test.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 B
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• pp.715-717
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• 1999

In this study, an intelligent solenoid valve controller has been developed for automatic maintaining of filters in a dust collecting system. This controller has automatic controllability of solenoid valves' ON/OFF time depending on the clogging status of filters, and then it can extend the filters' lifetimes, decrease the power consumption, and make effective operation of the system possible. This controllability has been executed by the fuzzy theory that utilizes the workers' experimental knowledges, the control expert's knowledges and the differential pressures between the inlets and outlets measured by the sensors.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.132.1-132
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• 2001

In this paper, we have studied for development of unmanned remote supervisory system using mobile communication network, not wire network, not to be affected by space or distance. The unmanned remote supervisory system consists of data processing unit main part and measuring systems (modules part)-temperature measuring module, humidity measuring module and human body sensing module. The data processing unit to collect and process informations of each measuring module has the functions of data communication between a mobile cellular telephone and measuring systems. Each measuring module has supervisory and warning functions for a target of supervision. And then we have designed each system and evaluated accuracy and reliability of the combined total system.

• ALGAE
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• 제17권3호
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• pp.153-159
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• 2002

Partial 16S rRNA gene sequences of seven cyanophycean strains from the National Instiute of Environmental Research of Korea - Microcystis aeruginosa, M. aeruginosa f. aeruginosa, M. ichthyoblade, M. viridis, Anabaena flos-aquae, and Oscillatoria sancta - were analyzed and the phylogenetic relationship of Microcystis among Cyanophyceae were evaluated. Based on sequence analysis results, Microcystis is monophyletic, the clade of which supported 100% bootstrap tress, and distinguished clearly from the other taxa. Therefore, the partial 16S rRNA gene sequences can be a useful and efficient tool for distinguishing Microcystis from other cyanophycean without axenic culture or cloning.

• Journal of the Optical Society of Korea
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• 제4권2호
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• pp.79-85
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• 2000

The main purpose of this paper is to present the potential of photovoltaic systems using holographic solar concentrators. A hologram used here focuses light, spectrally splits it and diverts unwanted infrared heat away from the solar cell. The output of the hologram appears as a perpendicular thin spectral line and is displaced to solar cells on both sides. To obtain optimum design conditions we used the coupled wave theory and the vector ray tracing method. The measured data showed that the diffraction efficiency was 75 ％ and the spectral bandwidth was 350 nm.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.2010-2012
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• 2008

This study describes a system for human sensibility evaluation using PPG(photoplethysmogram) signal and biofeedback algorithm to respond the bad(negative) mood. For this objective, PPG signals for two emotional states(positive/negative) are collected. To evoke the test emotions, happy(or joyful) and sad(or irritating) movie files are collected and played in subjects' monitor. From the acquired PPG signal, the heart rate variability(HRV) is calculated. Using the HRV and its FFT spectra, the human sensibility is evaluated. Since the heart is a representative organ which is controlled by the autonomic nervous system(ANS), the ANS may reflect the changes in emotion. The biofeedback algorithm is designed with motion image player interacting with the results of the sensibility evaluation. It was shown that HRV was changed according to the subject's emotions. Accordingly, the sensibility evaluation test showed feasibility of the our method.