• The Korean Journal of Nuclear Medicine
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• v.39 no.6
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• pp.421-429
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• 2005

Purpose: It has been postulated that dopamine release in the striatum underlies the reinforcing properties of nicotine. Substantial evidence in the animal studies demonstrates that nicotine interacts with dopaminergic neuron and regulates the activation of the dopaminergic system. The aim of this study was to visualize the dopamine release by smoking in human brain using PET scan with $[^{11}C]raclopride$. Materials and Methods: Five male non-smokers or ex-smokers with an abstinence period longer than 1 year (mean age of $24.4{\pm}1.7$ years) were enrolled in this study $[^{11}C]raclopride$, a dopamine D2 receptor radioligand, was administrated with bolus-plus-constant infusion. Dynamic PET was performed during 120 minutes ($3{\times}20s,\;2{\times}60s,\;2{\times}120s,\;1{\times}180s\;and\;22{\times}300s$). following the 50 minute-scanning, subjects smoked a cigarette containing 1 mg of nicotine while in the scanner. Blood samples for the measurement of plasma nicotine level were collected at 0, 5, 10, 15, 20, 25, 30, 45, 60, and 90 minute after smoking. Regions for striatal structures were drawn on the coronal summed PET images guided with co-registered MRI. Binding potential, calculated as (striatal-cerebellar)/cerebellar activity, was measured under equilibrium condition at baseline and smoking session. Results: The mean decrease in binding potential of $[^{11}C]raclopride$ between the baseline and smoking in caudate head, anterior putamen and ventral striatum was 4.7%, 4.0% and 7.8%, respectively. This indicated the striatal dopamine release by smoking. Of these, the reduction in binding potential in the ventral striatum was significantly correlated with the cumulated plasma level of the nicotine (Spearman's rho=0.9, p=0.04). Conclusion: These data demonstrate that in vivo imaging with $[^{11}C]raclopride$ PET could measure nicotine-induced dopamine release in the human brain, which has a significant positive correlation with the amount or nicotine administered bt smoking.

• Journal of the Korean Chemical Society
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• v.47 no.5
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• pp.472-478
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• 2003

In this work, the zeolite/diglycidylether of bisphenol A(DGEBA) systems were investigated in terms of the cure kinetics and mechanical interfacial properties of the composites. The 4, 4-diamino diphenyl methane(DDM) was used as a curing agent for epoxy. Two types of zeolite(PZ) were prepared with 15 and 35 wt% KOH treatments(15-BZ and 35-BZ, respectively) for 24 h, and their surface characteristics were studied by X-ray photoelectron spectroscopy (XPS) and X-ray diffraction(XRD). Cure kinetics of the composites were examined in the context of differential scanning calorimetry(DSC), and mechanical interfacial properties were investigated in critical stress intensity factor($K_{IC}$) and critical strain energy release rate($G_{IC}$). In the results of XPS and XRD, sodium ion(Na) of zeolite was exchanged for potassium ion(K), resulting from the treatment of KOH. Also, $Si_{2p}/Al{2p}$ composition ratios of the treated zeolite were increased, which could be attributed to the weakening of Al-O bond in framework. Cure activation energy($E_a$) of 15-BZ composites was decreased, whereas KIC and $G_{IC}$ were increased, compared with those of the pure zeolite/DGEBA composites. It was probably accounted that the acidity of zeolite was increased by surface treatments and the cure reaction between zeolite and epoxy was influenced on the increased acidity of zeolite.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.8
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• pp.3541-3546
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• 2011

Autophagy is an evolutionarily conserved lysosomal pathway for degrading cytoplasmic proteins, macromolecules, and organelles in addition to recycling protein and ATP synthesis. Although autophagy is very important during embryogenesis, the mechanism underlying the dynamic development during this process remains largely unknown. In order to obtain insights into autophagy in early embryo development, we analyzed gene expression levels of autophagy-related genes (ATGs) in mouse embryos developing in vitro. Using real time RT-PCR technique, ATGs including Atg2a, Atg3, Atg4b, Atg5, Atg6, Atg7, Atg9a, and Wipi3, as maternal transcripts, were only up-regulated in 1-cell embryo stage before zygotic genomic activation (ZGA), and then expression decreased from 2-cell to blastocyst embryo stage. ATGs including Dram and Atg9b were expressed abundantly in 1-cell embryo state and in blastocyst embryo stage, athough Atg8 and Ulk1 were constantly expressed during preimplantation stage. However, Atg4d were only up-expressed from 4-cell to blastocyst stage. These results suggest that autophagy is related in mouse embryo, which possibly gives an important role for early development.

• The Journal of the Korea Contents Association
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• v.18 no.2
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• pp.147-157
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• 2018

Recently, with the advancement of network technologies, and the activation of IoT and social network services, many graph stream data have been generated. As the relationship between objects in the graph streams changes dynamically, studies have been conducting to detect or analyze the change of the graph. In this paper, we propose a scheme to incrementally detect frequent patterns by using frequent patterns information detected in previous sliding windows. The proposed scheme calculates values that represent whether the frequent patterns detected in previous sliding windows will be frequent in how many future silding windows. By using the values, the proposed scheme reduces the overall amount of computation by performing only necessary calculations in the next sliding window. In addition, only the patterns that are connected between the patterns are recognized as one pattern, so that only the more significant patterns are detected. We conduct various performance evaluations in order to show the superiority of the proposed scheme. The proposed scheme is faster than existing similar scheme when the number of duplicated data is large.

• Science of Emotion and Sensibility
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• v.5 no.4
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• pp.51-57
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• 2002

The purpose of the study was to measure and compare driver's psychophysiological responses in different driving conditions through driving simulator. Twelve male adults(more than 1 year of driving experience) were assigned to four different driving conditions, such as normal speed(70㎞/h), sudden start(0㎞/h→70㎞/h), and sudden stop(70㎞/h→0㎞/h), and their simulator sickness, subjective pleasantness and arousal, EEG, ECG, skin temperature, and GSR were measured. Subjective and physiological evaluations were executed before and after driving in each condition. The results showed that subjective pleasantness and arousal increased in sudden stop and sudden start conditions, relative to stop and normal speed conditions. As the central nervous responses, beta wave increased and alpha wave decreased in sudden stop and sudden start conditions, relative to stop and normal speed conditions. With regard to the autonomic responses, heart rate and GSR increased, while skin temperature decreased in sudden stop and sudden start conditions, which means an activation of sympathetic nervous system. The results suggested that based upon observation of the distinctive psychophysiological changes by driving conditions, it is possible to evaluate the human sensibility in dynamic environment.

• Polymer(Korea)
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• v.25 no.4
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• pp.558-567
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• 2001

The syntheses of thermal latent catalysts have been carried out by modifying the substituent of pyrazinium salts. The thermal latent properties and cure behaviors of difunctional epoxy resin (diglycidylether of bisphenol-A, DGEBA) with 1 wt% of catalyst as an initiator were investigated by dynamic DSC method. As a result, the synthesized catalysts showed the good latent thermal properties in epoxy system. With increasing the basicity of substituted catalyst, the cure temperature and activation energy of epoxy system were increased, whereas the activity was decreased. This was probably due to the fact that the activity and cure behavior were controlled by ring strain and basicity of substituent. Consequently, the catalyst activity modified by methyl group as an electron donor was decreased in increasing of basicity in an initiation step of epoxy cure system. This is due to a decreasing of stabilities of both leaving group of pyrazinium salts and benzyl cation. However, the catalyst activity modified by cyano group as an electron acceptor was increased in increasing the stability of benzyl cation resulting from organic effects and resonance.

• Journal of KIISE:Software and Applications
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• v.28 no.1
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• pp.52-63
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• 2001

필기 단어 인식 방법에는 낱자별 분할 및 낱자 단위 인식을 통해 인식하는 방법과 단어 사전을 이용하여 단어와 영상을 직접 비교하는 방법이 있다. 이 중 후자는 인식 대상이 되는 단어들이 작은 수의 어휘로 제한되었을 대 매우 효과적이다. 본 논문에서는 입력 영상이 주어졌을 때 자모를 순차적으로 탐색하고 그 결과의 최적 조합을 찾아 인식하는 사전을 이용한 필기 한글 단어 인식 방법을 제안한다. 입력 영상은 사전의 각 단어와의 매칭을 통해 인식된다. 단어는 필기 순서로 정렬된 자모열로 표현하고 입력 영상은 획들의 집합으로 표현한다. 단어의 자모들은 입력 영상으로부터 추출된 획들의 집합으로부터 단계적으로 탐색된다. 각 단계에서는 전 단계까지의 매칭 상태와 탐색하려는 자모의 형태로부터 자모가 존재할 것이라고 기대되는 정합 기대 영역을 설정한 후 그 안에서 자모 탐색기를 이용해 자모를 찾는다. 자모 탐색기는 획들의 집합으로 이루어진 복수의 자모 후보와 그 점수를 출력한다. 각 단계마다 생성된 자모 후보들은 최적의 단어 매칭을 찾기 위한 탐색 공간을 이룬다. 본 연구에서는 단어 사전을 trie로 구성하고, 탐색 과정에서 dynamic programming을 이용하여 효과적으로 탐색을 수행하였다. 또한 인식 속도를 향상시키기 위해 산전 축소, 탐색 공간 축소 등 다양한 지식을 이용하였다. 제안하는 방법은 무제약으로 쓰여진 필기 단어도 인식 할 수 있을 뿐 아니라, 동적 사전을 이용하기 때문에 사전의 내용이 변하는 환경에서도 적용할 수 있다. 인식 실험에서는 39개의 단어로 이루어진 사전에 대하여 613개의 단어 영상에 대해 실험한 결과 98.54%의 높은 인식률을 보임으로써 제안하는 방법이 매우 효과적임을 확인하였다. 아니라 곰팡이 균주도 실제 praxis에 적합하게 개발시킬수 있다. 따라서 앞으로 발효육제품제조에 있어 starter culture가 갖는 의미는 매우 중요하며 특히 짧은 숙성기간을 거치는 발효소시지의 제조에 있어서는 필수불가결한 공정의 한 분야로 자리잡게 될 것이다.큰 차이 없었으나 이중포장과 진공포장은 상당히 효과적임을 알 수 있었다.로는 18%에 비하여 22%가 더 적합한 것으로 생각되었다.$0.15{\sim}0.35%$이었다.irc}C$에서 $13.49{\times}10^{-3}$이었다. 이 값들을 Arrhenius식에 대입하여 구한 활성화 에너지는 24.795 kJ/Kmol이었다. 이 값으로부터 결정한 살균 포장약주 명가의 상용 저장 수명은 $10^{\circ}C$에서 2년, $20^{\circ}C$에서 1년 4개월, $25^{\circ}C$에서 1년 2개월 이었다. 서울의 매월 평균 온도를 기준으로 계산할 때 본제품의 상용저장기간은 1년 8개월이었다.로 반죽이 호화되고 가열시간이 그 이상으로 증가할 때도 반죽의 호화가 약간은 진행되지만 $90^{\circ}C$ 이상의 가열온도에서는 가열시간 0.5분 이내에 반죽의 호화가 급속히 일어나고 가열 시간을 증가시켜도 더이상의 호화는 일어나지 않았다. 같은 조건에서는 waxy corn starch 반죽의 호화 속도가 corn starch보다 더 빠른 것으로 나타났다. 대표적으로 52% 수분함량에서 반응속도상수(k)와 가열온도(T)사이의 관계식은 corn starch의 경우 $logk=11.1140-4.1226{\times}10^3(1/T)

• Journal of Digital Contents Society
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• v.19 no.2
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• pp.309-318
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• 2018

We proposed a marketing plan for the performing arts venue using realistic contents(VR, AR, and MR). The venue is a place where the audience can experience the performance directly. The marketing plan of the performance venue is as follows. Firstly, it is a marketing strategy that utilizes an arrangement of venue seats. It is possible to predict for watching a performance at angle and sight in performance venue seats that audience want through VR. This allows the theatre seats to be experienced in advance with the VR contents inducing the reservation of the seats with a high sense of immersion. Secondly, it is a marketing using PR and AD of performing arts through MR in the space with a large transient population. It is possible to promote dynamic promotion utilizing the sense of the presence of performing arts compared with existing static promotion means. Thirdly, it is a marketing strategy that utilizes actor characters in performance. The audience could be interested in the performing arts in advance via a preview of the AR contents of the pamphlet. Fourthly, it is a way to communicate with customers directly by establishing a VR social network to manage venue members. This will help attract an audience to revitalize the theatre venue.

• Polymer(Korea)
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• v.36 no.2
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• pp.245-250
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• 2012

Branched polypropylenes (PP) with long chain branch were prepared by solid state reaction with three different branching agent of 0.3 wt% content. The chemical structures, non-isothermal crystallization behavior and complex viscosity of the branched PP were investigated by FTIR, DSC, optical microscope, and dynamic rheological measurement. The chemical structure of the branched PP was confirmed by the existence of =C-H stretching peak of the branching agent at 3100 $cm^{-1}$. There was no distinct change in melting temperature in case of PP-D-0-3 and PP-F-0-3, but PP-H-0-3 indicated a decrease in melting temperature. The decrease in melting temperature was interpreted by the fact that the degradation reaction of PP was more dominant than branched reaction, and confirmed by a decrease in complex viscosity. The non-isothermal crystallization behavior of the branched PP was analyzed using by Avrami equation. The Avrami exponent of PP was 3, and the values of the branched PP with DVB and FS were below 3. The activation energy of PP calculated by Kissinger method was 25 kJ/mol, and there were no big difference in activation energies of the branched PPs compared to PP.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.08a
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• pp.3-3
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• 2010

이번 성원에드워드 학술상 수상자 선정은, 진공기술의 중요성에 공감하고 진공기술 발전을 위한 노력을 독려하자는 진공학회 회원들의 의견을 모아주신 결과로 생각한다. 본 발표에서는 그동안 한국표준과학연구원에서 수행해 온 진공 기술 연구 및 산학연 협력 네트워크 활동을 소개하고자 한다. 진공기술은 진공 환경을 발생시키고 측정 제어하며, 만들어진 진공 환경 안에서 원하는 작업을 할 수 있도록 하는 기술을 말한다. 우리나라의 주력산업인 반도체 및 디스플레이의 경우 그 생산 설비의 1/3이상이 진공 장비이며 진공 공정을 통해 만들어진다. 때문에 우리나라에서는 주력 산업분야나 그 전후방 산업의 경쟁력 강화 측면에서 진공기술 개발 중요성이 아주 크다. 한국표준과학연구원은 국가 대표 측정 기관으로 국가 측정 표준을 확립하고 측정관련 과학기술을 연구개발하며 그 성과를 보급하여 경제발전과 과학기술발전, 그리고 삶의 질 향상에 기여하는 것을 임무로 하고 있다. 우리나라에서 진공 측정 표준에 대한 연구가 본격적으로 시작된 것은 1984년으로 불용 장비로 불하받은 펌프와 챔버, 그리고 차관으로 도입된 Capacitance Diaphragm Gauge 몇 개만으로 시작되었다. 지금은 발전을 거듭하여 초음파 간섭 수은주 압력계를 비롯하여 정적 팽창시스템, 동적 팽창 시스템 등 진공도 범위별 국가 표준기와 리크 표준기를 자체 개발 하여 국가 측정 표준을 확립하고 있다. 우리나라의 진공 표준 및 측정 능력은 국제기구인BIPM에서 실시하는 국가 측정능력 비교시험을 통해 세계 최고 수준으로 인정 받은 바 있으며 교정검사 등을 통해 산학연에 보급되고 있다. 진공 측정 및 표준기술을 토대로, 1999년부터 과학기술부와 산업자원부의 지원을 받아 산학연이 필요로 하는 펌프 계측기 부품 소재 및 공정 특성을 평가하기 위한 장치와 절차를 개발하였다. 이를 이용해 보급되는 기술 data는 진공부품 및 장비 국산화, 국산제품 신뢰성 제고, 검증부품 사용을 통한 장비 품질 향상, 독자적 장비 기술 확보, 생산품 품질관리 등에 쓰이고 있다. 한국 표준연구원 진공센터의 교정 및 시험 능력은 ISO 9001 인증 획득과 국제 전문가의 review를 거쳐, 국제기구 측정능력표에 등재되어 있어 국제적 신뢰도도 확보하고 있다. 정기적인 진공기술 교류회를 개최하고 진공기술 홈페이지를 운영 하는 등 산학연 정보 교류 및 협력 네트워킹 활성화를 위해 노력한 바 있으며 이 분야의 연구 성과는 '국가 우수 연구성과 100선'에 선정된 바 있고, 산업자원부 지정 '산학연 연계 우수사례' 첫 번째로 선정되기도 하였다. 2008년부터는 진공기술 교류회 등을 통한 네트워킹 활동으로 도출된 기술 수요에 따라 대기업과 중소기업 학교 연구소들과 함께 진공공정 실시간 측정 진단 기술과 센서 개발 연구, 그리고 이들 개발품의 신뢰성 검증 및 평가 기술 개발을 위해 노력하고 있다.