• Journal of the Korean Institute of Intelligent Systems
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• v.22 no.1
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• pp.62-68
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• 2012

Steady-State Visually Evoked Potentials (SSVEP) are natural response signal associated with the visual stimuli with specific frequency. By using SSVEP, occipital lobe region is electrically activated as frequency form equivalent to stimuli frequency with bandwidth from 3.5Hz to 75Hz. In this paper, we propose an experimental paradigm for analyzing EEGs based on the properties of SSVEP. At first, an experiment is performed to extract frequency feature of EEGs that is measured from the image-based visual stimuli associated with specific objective with affordance and object-related affordance is measured by using mirror neuron system based on the frequency feature. And then, linear discriminant analysis (LDA) method is applied to perform the online classification of the objective pattern associated with the EEG-based affordance data. By using the SSVEP measurement experiment, we propose a Brain-Computer Interface (BCI) system for recognizing user's inherent intentions. The existing SSVEP application system, such as speller, is able to classify the EEG pattern based on grid image patterns and their variations. However, our proposed SSVEP-based BCI system performs object pattern classification based on the matters with a variety of shapes in input images and has higher generality than existing system.

• Journal of the Korean Society of Food Science and Nutrition
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• v.25 no.6
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• pp.944-950
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• 1996

The purpose of our study is to investigate the changes of physico-chemical properties according to packaging methods(vacuum packaged with polyamide/polyethylene, air packaged with polyvynyl-chloride) and illumination on the properties of Hanwoo beef. pH value in vacuum packaged beef tended to be decreased, but pH value in air packaged beef tended to be increased during storage for 21 days, irrespective of illumination. Contents of volatile basic nitrogen(VBN) and thiobarbituric acid(TBA) values were increased, regardless of packaging methods. However, vacuum packaged beef showed lower VBN, TBA values than those of air packaged beef. Red color(CIE a value) was also decreased. Regardless of packaging method, saturated fatty acids(SFAs) were increased, but unsaturated fatty acids(UFAs) were relatively decreased. And in the ratio of the UFA/SFA, vacuum packaged beef had lower UFA/SFA ratio than that of air packaged beef. In this study, the effect of illumination did not change on physico-chemical properties in Hanwoo beef. In conclusion, the results indicate that the vacuum packaging treatment was more important to prolong the shelf-life of Hanwoo beef than air packaging method.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.05a
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• pp.951-953
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• 2015

Learning for thinking says the behavior of the organism changes as a result of practice or experience. It is very difficult to identify focusing ability objectively when students study. But, brain of the body is not so. EEG signal means continuously electric records of brain potential variation between two points on the scalp when brain activities take place. In types of EEG, there are delta(0~4Hz), theta(4~8Hz), alpha(8~13Hz), beta(13~30Hz) and gamma waves(30~50Hz). SMR waves and Mid-beta waves appear when focused for studying. Part for the most influence on concentrating reported that Mid-beta waves. In relation to brain activities, EEG has been actively researched for evaluating brain focus index system during learning and study. So, By using Biopac system for this study, measured brain wave was converted into FFT for extracting Mid-beta domain signals that are related to learning after giving focus invoked subjects to a small number of people. When concentrating, we measured the change in the power of the Mid-beta frequency domain and presented a correlation. Based on these results, we analyzed whether students are concentrated objectively on learning or not. and hope to offer more efficient learning method.

• Journal of the Korean Society of Radiology
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• v.8 no.7
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• pp.371-376
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• 2014

The process of flip-chip bump bonding, Au wire bonding and encapsulation were sucessfully developed and modularized. The CdTe sensor and ROIC were optimally jointed together at $150^{\circ}C$ and $270^{\circ}C$ respectively under24.5 N for 30s. To make SnAg bump on ROIC easy to be bonded, the higher bonding temperature was established than CdTe sensor's. In addition, the bonding pressure was lowered minimally because CdTe Sensor is easier to break than Si Sensor. CdTe multi-energy sensor module observed were no electrical failures in the joints using developed flip chip bump bonding and Au wire bonding process. As a result of measurement, shearing force was $2.45kgf/mm^2$ and, it is enough bonding force against threshold force, $2kgf/mm^2s$.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.8 no.2
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• pp.83-90
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• 2009

White LEDs(Light Emitting Diode) offer advantageous properties such as high brightness, improved reliability, lower power consumption, and long lifetimes. An LED is an electronic device that converts an electrical signal into a tight signal and is used not only in Optical Communication Indoor wireless optical illuminating rooms, but also for wireless optical communication systems. Currently, studies about these white LEDs have been being progressed, and in this raper, we discuss the multiplex and the multiple access method of VLC(Visible Light Communication) systems using white LEDs. In proposed system, CDMA(Code Division Multiple Access) apples to VLC system to reduce interference of VLC system, and improve capacity. The superiority of OOK modulation is presented in analysis of results by comparing VLC-CDMA communication system using OOK(On-off keying) modulation and BPSK modulation in AWGN(Additive White Gaussian Noise) channel and Diffuse channel. And we investigate the significance of a solution of interference by multipath by comparing BER in multipath channel and AWGN channel. In the proposed system, we assume Directed LOS(Line Of Sight) and Diffuse Link, and suppose VLC-CDMA using OOC(Optical Orthogonal Code) as methods to increase efficiency of system by removing ISI(Inter Symbol Interference) caused by multiple access, optical spreading code, and also present an analysis of its performance.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.36D no.6
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• pp.28-34
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• 1999

We fabricated a planar ultra-violet photodetector whose ohmic and schottky contacts were respectively formed with evaporated Al and Pt on the GaN layer. To examine the applicability of the device to the UV sensor, we investigated its electrical and optical characteristics. The GaN layer on the sapphire waver had $7.8{\times}10^{16}cm^{-3}$ of doping concentnation and the $138 cm^2/V{\cdot}s$ of electron mobility and it absorbed the spectrum of the light below 325 nm wavelength. It had the responsivity of 2.8 A/W of at 325 nm, and the signal to noise ratio(SNR) of $4{\times}10^4$, and the noise equivalent power(NEP) of $3.5{\times}10^9$W under 5 V reverse bias. These results confirmed that the GaN schottky diode had a solar blind properly when it was applied to the UV photodetector.

• Korean journal of applied entomology
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• v.35 no.3
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• pp.209-215
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• 1996

DNA polymorphisms were analyzed for 8 clones of the green peach aphid, Myzus persicae Sulzer, by random amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR). The insect has different host preferences and was even classified into two different species, M. persicae Sulzer and Myzus nicotinae Blackman by their morphological characters, but this point is still in arguement. To identify the differences between two types of the green peach aphid by RAPD-PCR, the template DNA was extracted from 4 clones each of tobacco-feeding and non-tobacco-feeding forms and one hundred primers of 10-nucleotideslong were tested in PCR. The amplified DNAs were analyzed by agarose gel electrophoresis. Eighty-three primers gave amplified DNA fragments with 1 to 22 in number and 500 to 20,000 base pairs in length, but no amplification was observed in the other 17 primers. The average number of fragment per each amplification was about 13. In the case of 82 out of 83 random primers, band patterns of amplified DNA were identical among 8 clones, even though some differences were noticed in the intensity of specific bands. Polymorphism was detected by only one primer within the tobacco-feeding forms, but not between the two host types. The results did not detect any relationship between RAPD polymorphism and their host preference.

• Proceedings of the Korean Society for Environmental Edudation Conference
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• 2002.01b
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• pp.1-168
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• 2002

이 연구는 지난 20여 년 동안 우리나라 환경교육의 활성화를 위하여 많은 연구자, 학교 교사, 환경단체 지도자가 제안해 온 과업을 다루고있다. 그것은 학교 안팎에 걸쳐 요람에서 무덤까지 환경교육이 체계적이고 지속적으로 이루어질 수 있도록 법적, 제도적 기반을 마련하는 것이다. 법제적 뒷받침이 환경교육의 활성화를 위한 충분조건은 되지 못하더라도 필요조건으로서 매우 중요한 의미를 갖고 있다는 점은 분명하다. 이 연구를 수행한 사단법인 한국환경교육학회는 국회환경포럼과 함께 환경교육진흥법(가칭) 시안의 개발과, 나아가 실질적인 입법화를 위해 노력하였다. 이를 위하여 먼저 우리나라에 이미 존재하는 도서벽지 교육진흥법, 특수교육진흥법, 산업교육진흥법, 영재교육진흥법, 과학교육진흥법, 유아교육진흥법, 이상 여섯 개의 교육진흥법을 분석하여 환경교육진흥법 시안 개발을 위한 시사점을 얻고자 하였다. 다음으로 외국의 환경교육 관련법에 대한 사례 연구를 진행하였다. 특히 미국의 경우 1970년 처음 환경교육법이 제정된 이후 몇 차례의 개정과 재승인 과정을 거쳐왔다. 미국에서는 1990년에 제정된 국가환경교육법의 재승인에 관한 공청회가 지난 2000년 여름 동안 개최되어 환경교육법의 필요성, 효과, 고려할 조항 등 본 연구에 중요한 참고 자료를 얻을 수 있었다. 본 학회의 다른 연구진에 의해 2001년 10월에 완료된 제2차 환경교육 중 ·장기 강화방안 연구의 결과물도 환경교육 활성화를 위한 시안에 담아야 할 내용과 방향을 결정하는데 실질적인 도움을 주었으며, 이를 토대로 연구진과 국회환경포럼의 환경교육활성화위원회의 위원이 윤독과 수정을 거쳐 시안의 타당성과 완성도를 높이고자 하였다. 작성된 시안에 대해서는 먼저 국내의 환경 또는 환경교육 관련 전문가에게 설문지를 보내어 의견 수렴을 하였으며, 이 과정에서 시안에 포함된 대부분의 항목에 대해 높은 찬성률을 보인 것으로 나타났다. 그밖에 설문지로부터 수정 ·보완 요청 사항을 정리하여 최종 시안을 작성하는데 반영하였다. 끝으로 10월 26일 국회 의원회관에서 개최된 공청회를 통하여 다양한 집단의 의견을 수렴하였으며, 공청회 동안 제시된 의견들을 반영하여 최종 시안을 작성하였다. 이러한 과정을 거쳐 작성된 환경교육진흥법 최종 시안은, 제1조 목적에서 제11조 환경교육연구의 진흥에 이르기까지 총11조로 구성되었으며, 환경교육사 자격증제 및 환경교육 프로그램 인증제 등 획기적인 전기를 마련할 수 있는 방안들이 다수 포함되어 있다. 특히 환경교육진흥법의 주무 부처를 환경부로 제안한 것은 기존의 교육 관련 진흥법들이 교육인적자원부를 주무로 하고 있는 것에 비해 매우 특기할 만 하다. 그 이유는 본문에서 밝힌 바와 같이 환경교육이 갖고 있는 특수성 때문이다. 환경교육진흥법의 주무 부처를 환경부와 교육인적자원부 중 어디로 하는 것이 바람직한가에 대해서는 연구진 내부는 물론 공청회에 참가한 사람들 사이에도 이견이 있었음을 밝혀 둔다. 끝으로, 이 연구에서 마련된 시안과 연구 결과가 최종적으로 속히 법제화가 되고, 우리나라 환경교육 진흥에 기여하게 되기를 바란다.

• Science of Emotion and Sensibility
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• v.13 no.1
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• pp.235-242
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• 2010

Emotion science is one of the rapidly expanding engineering/scientific disciplines which has a major impact on human society. Such growing interests in emotion science and engineering owe the recent trend that various academic fields are being merged. In this paper we review the recent techniques in the measuring the emotion related elements and applications which include animal model system to investigate the neural network and behaviour, artificial nose/neuronal chip for in-depth understanding of sensing the outer stimuli, metabolic controlling using emotional stimulant such as sounds. In particular, microfabrication techniques made it possible to construct nano/micron scale sensing parts/chips to accommodate the olfactory cells and neuron cells and gave us a new opportunities to investigate the emotion precisely. Recent developments in the measurement techniques will be able to help combine the social sciences and natural sciences, and consequently expand the scope of studies.

• Journal of radiological science and technology
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• v.33 no.3
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• pp.289-294
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• 2010

The purpose of this study is an evaluation of the performance of a detector under radiographic irradiation condition by fabricating the polycrystalline $HgI_2$ film detector. The polycrystalline $HgI_2$ film detectors with thickness of 210 and $320\;{\mu}m$ were fabricated by screen print technology. Measurements of X-ray sensitivity and dark current were performed for two detectors. And measurements of the linearity of X-ray response and reproducibility were performed for the detector of thickness $320\;{\mu}m$. For applied electric field strengths from 0.05 to $2\;V/{\mu}m$ to the detector of thickness $320\;{\mu}m$, the X-ray sensitivities were measured from 233 to $1,408{\times}106\;electrons/mR{\cdot}mm^2$. And the dark currents were measured from 3.2 to $118\;pA/mm^2$. Compared with values reported by Zhong Su et al., the X-ray sensitivities exhibit about two times larger than the X-ray sensitivities measured by Zhong Su et al. And the dark currents exhibit about nine times larger than the dark currents measured by Zhong Su et al. The linearity of X-ray response acquired 0.988 as a coefficient of correlation (r). Reproducibility acquired 0.002 as a coefficient of variation. This study provides the performance data of fabricated polycrystalline $HgI_2$ film detector available for an active matrix flat panel imager under radiographic irradiation condition.