중성자를 이용한 리튬이온 이차전지 전극 구조분석

김창섭,박헌용,양연화,김지영,성백석,김건,Kim, Chang-Seob,Park, Heon-Yong,Liang, Lianhua,Kim, Ji-Young,Seong, Baek-Seok,Kim, Keon 한국전기화학회 2007 한국전기화학회지 Vol.10 No.1

최근 높은 에너지 밀도를 갖고 있는 리튬 이온 이차전지에 대한 관심이 높다. 리튬 이온 이차전지는 이미 휴대용 기기로 널리 적용되고 있으며, 하이브리드 전기자동차와 같은 고출력 전지시스템에 적용을 위해 연구되고 있다. 리튬 이온 이차전지의 전극 소재는 리튬 이온의 이동에 의해서 충전 및 방전되는 현상을 활용한다. 전극으로부터 리튬 이온이 이동될 때 전극내의 구조 변화가 발생한다. 전극의 구조분석은 중성자 또는 X-선을 이용하여 분석할 수 있다. X-선은 분석 시간이 짧고, 쉽게 분석할 수 있다는 장점이 있으나 원자내의 전자구름과의 산란을 응용하므로 전자가 적은 가벼운 원소의 경우 분석이 어려운 단점이 있다. 리튬도 원자량이 작아서 X-선 만으로는 리튬의 정확한 위치에 대한 분석이 어렵다. 중성자 분석기술은 이에 대한 해답이 될 것이다. 본 자료에서는 중성자를 활용한 전극물질의 구조 분석 사례 및 그 원리에 대해서 논의하고자 한다. Lithium ion secondary battery has been applied widely to portable devices, and has been studied for application to high power electric cell system such as power tool or hybrid electronic vehicle. The structure change of the electrodes materials occur when lithium ions move between electrodes. Neutron or X-rays can analyze the structure of electrode. The advantage of X-rays is convenient in test. However X-rays is scattered by electron cloud in atoms. Therefore, The elucidation for correct position of lithium is difficult with X-rays because lithium has small atomic weight. Neutron analysis techniques could solve this problem. In this review, We wish to discuss about structure analysis and the principle of structural characterization method using neutron beam source.

해외 가축전염병 방역 현황 및 대책

김창섭,Kim, Chang-Seop 대한양돈협회 1988 養豚 Vol.10 No.9

성인 남자에서 대장경 검사로 확인된 하부대장 선종성 용종과 비만의 관련성

김창섭,정해관,정태흠,김문찬,Kim, Chang-Sup,Cheong, Hae-Kwan,Jeong, Tae-Heum,Kim, Moon-Chan 대한예방의학회 2005 Journal of Preventive Medicine and Public Health Vol.38 No.4

Objectives : We wanted to evaluate the relationship between obesity and left colonic adenomatous polyps in Korean adult men. Methods : This study was conducted among 575 adults men (aged between 40 and 69), who had colonoscopy done from January to December 2002 during a routine health examination at Health Promotion Center, Ulsan University Hospital. The patients' colons were examined up to splenic flexure by using fiberoptic colonoscopy. A questionnaire survey on behavioral factors and physical measurements were also done. The body mass index (BMI) and waist-hip ratio (WHR) were used as the indices of obesity. The BMI was categorized into three levels: normal ($BMI{\leq}22.9$), overweight ($23{\leq}BMI{\leq}24.9$), and obese ($BMI{\geq}25.0$). The WHR was categorized into four levels with cutoff points at the 30th, 60th, and 90th percentile of the control group. Age, education, smoking, alcohol use and exercise were controlled for by performing multiple logistic regression analysis. Results : There were 99 cases of colonic adenomatous polyps. Four hundred seventy six subjects with normal colonoscopy findings served as the control. The BMI and WHR were associated with the adenomatous polyps (odds ratio, 1.81 [95% CI=1.02-3.19] for a $BMI{\geq}25.0$ as compared with a $BMI{\leq}22.9$, odds ratio, 3.94 [95% CI=1.77-8.77] for a $WHR{\geq}0.95$ as compared with a $WHR{\leq}0.86$). The BMI was not associated with the risk of adenomatous polyps after additional adjustment was made for the WHR, but the association between the WHR and adenomatous polyps was still positive and independent of the BMI (odds ratio, 4.15 [95% CI=1.63-10.59]). Conclusions : The results support that obesity, and particularly abdominal obesity, can be associated with an increased risk of incurring colonic adenomatous polyps.

간섭 및 성능 분석을 위한 LTE 시스템 기반 펨토셀 시뮬레이터 개발

김창섭,최범곤,구본태,이미영,정민영,Kim, Chang-Seup,Choi, Bum-Gon,Koo, Bon-Tae,Lee, Mi-Young,Chung, Min-Young 한국시뮬레이션학회 2011 한국시뮬레이션학회 논문지 Vol.20 No.1

최근 가정 또는 사무실과 같은 실내 환경에서 음영지역을 해소하고 고품질의 서비스 제공을 위한 방안으로 초소형 기지국인 펨토셀(Femtocell)이 많은 관심을 받고 있다. 펨토셀은 사업자 및 사용자에게 다양한 이점을 제공하지만 펨토셀의 도입을 위해 서는 채널 선택에 따른 간섭제어, 네트워크 동기화, 자기 최적화 등 다양한 기술적 문제점이 해결되어야 한다. 이를 위해 본 연구에서는 펨토셀의 도입으로 인하여 발생 가능한 다양한 신호간섭 문제들에 대한 분석을 용이하게 하기 위한 LTE(Long Term Evolution) 시스템 기반 펨토셀 시뮬레이터를 개발하였다. 개발된 시뮬레이터는 단말 이동성, 스케줄러, 호 수락 제어, 트래픽 생성, MCS(Modulation and Coding Scheme) 결정의 5개의 블록과 이를 연결하고 관리하는 메인 모듈로 구성되어 있다. 또한 사용자의 편의성을 도모하기 위하여 시뮬레이션 결과를 실시간으로 관측할 수 있는 GUI(Graphical User Interface)를 적용하였다. 본 시뮬레이터는 실제와 유사한 환경에서 매크로셀과 펨토셀 사이의 간섭영향을 면밀히 분석하고 이동통신 시스템의 성능을 효과적으로 평가할 수 있도록 지원하며, 다양한 펨토셀 시스템을 개발하는데 크게 기여할 수 있을 것으로 예상된다. Recently, femtocell has been concerned as one of effective solutions to relieve shadow region and provide high quality services to users in indoor environments. Even though femtocell offers various benefits to cellular operators and users, many technical issues, such as interference coordination, network synchronization, self-configuration, self-optimization, and so on, should be solved to deploy the femtocell in current network. In this paper, we develop a simulator for evaluating performance of long term evolution (LTE) femtocell systems under various interference scenarios. The simulator consists of a main-module and five sub-modules. The main-module connects and manages five sub-modules which have the functionality managing user mobility, packet scheduling, call admission control, traffic generation, and modulation and coding scheme (MCS). To provide user convenience, the simulator adopts graphical user interface (GUI) which can observes simulation results in real time. We expect that this simulator can contribute to developing effective femtocell systems by supporting a tool for analyzing the effect of interference between macrocell and femtocell.

집중분석 - 새 정부에 바라는 에너지정책

김창섭,Kim, Chang-Seop 대한석유협회 2017 석유와 에너지 Vol.304 No.-

수종의 상아질색도재의 색차이에 대한 연구

김창섭,임장섭,전영찬,정창모,Kim, Chang-Seop,Lim, Jang-Seop,Jeong, Chang-Mo,Jeon, Young-Chan 대한치과보철학회 1999 대한치과보철학회지 Vol.37 No.4

The purpose of this study is to evaluate the color differences that can exist between different brands of dentin porcelain having identical shade designations. The instrumental colorimetric technique was used to determine these differences. The three brands of dentin porcelain used were Vita VMK-68, Shofu Vintage, and Ceramco II. The three shades selected were the Vita Lumin shades A2, B2, and C2. The color difference values were compared with each other using $L^*,\;a^*,\;b^*$, three variables of the CIELAB color system, and ${\Delta}E$. The results of this study were as follows: 1 Corresponding shades of different brands of dentin porcelain produced different $L^*,\;a^*,\;b^*$ values. 2. The greatest ${\Delta}E$ value in corresponding shade was found to exist between Ceramco II and Shofu Vintage, followed by between Vita VMK-68 and Ceramco II, and then between Vita VMK-68 and Shofu Vintage. 3. The ${\Delta}E$ values in shade C2 were mainly influenced by ${\Delta}L^*$ value ; however none of ${\Delta}L^*,\;{\Delta}a^*,\;{\Delta}b^*$ values had greater influence on ${\Delta}E$ values than the others in shade A2, B2. 4. Shofu Vintage had the highest $b^*$ value, followed by Vita VMK-68, and then Ceramco II.

정부의 가축분뇨 자원화 지원정책

김창섭,Kim, Chang-Seop 대한양돈협회 1995 養豚 Vol.17 No.4

Special Theme_스마트 그리드 - Korea Smart Grid와 국내외 산업동향

김창섭,Kim, Chang-Seop 한국정보통신기술협회 2010 TTA저널 Vol.129 No.-

다변량 프로빗 모형을 이용한 가전제품 구매의 상관관계 분석

김창섭,신정우,이미숙,이종수,Kim, Chang-Seob,Shin, Jung-Woo,Lee, Mi-Suk,Lee, Jong-Su 한국마케팅과학회 2009 마케팅과학연구 Vol.19 No.2

As the lifestyle of consumers changes and the need for various products increases, new products are being developed in the market. Each household owns various home appliances which are purchased through the choice of a decision maker. These appliances include not only large-sized products such as TV, refrigerator, and washing machine, but also small-sized products such as microwave oven and air cleaner. There exists latent correlation among possession of home appliances, even though they are purchased independently. The purpose of this research is to analyze the effect of demographic factors on the purchase and possession of each home appliances, and to derive some relationships among various appliances. To achieve this purpose, the present status on the possession of each home appliances are investigated through consumer survey data on the electric and energy product. And a multivariate probit(MVP) model is applied for the empirical analysis. From the estimation results, some appliances show a substitutive or complementary pattern as expected, while others which look apparently unrelated have correlation by co-incidence. This research has several advantages compared to previous literatures on home appliances. First, this research focuses on the various products which are purchased by each household, while previous researches such as Matsukawa and Ito(1998) and Yoon(2007) focus just on a particular product. Second, the methodology of this research can consider a choice process of each product and correlation among products simultaneously. Lastly, this research can analyze not only a substitutive or complementary relationship in the same category, but also the correlation among products in the different categories. As the data on the possession of home appliances in each household has a characteristic of multiple choice, not a single choice, a MVP model are used for the empirical analysis. A MVP model is derived from a random utility model, and has an advantage compared to a multinomial logit model in that correlation among error terms can be derive(Manchanda et al., 1999; Edwards and Allenby, 2003). It is assumed that the error term has a normal distribution with zero mean and variance-covariance matrix ${\Omega}$. Hence, the sign and value of correlation coefficients means the relationship between two alternatives(Manchanda et al., 1999). This research uses the data of 'TEMEP Household ICT/Energy Survey (THIES) 2008' which is conducted by Technology Management, Economics and Policy Program in Seoul National University. The empirical analysis of this research is accomplished in two steps. First, a MVP model with demographic variables is estimated to analyze the effect of the characteristics of household on the purchase of each home appliances. In this research, some variables such as education level, region, size of family, average income, type of house are considered. Second, a MVP model excluding demographic variables is estimated to analyze the correlation among each home appliances. According to the estimation results of variance-covariance matrix, each households tend to own some appliances such as washing machine-refrigerator-cleaner-microwave oven, and air conditioner-dish washer-washing machine and so on. On the other hand, several products such as analog braun tube TV-digital braun tube TV and desktop PC-portable PC show a substitutive pattern. Lastly, the correlation map of home appliances are derived using multi-dimensional scaling(MDS) method based on the result of variance-covariance matrix. This research can provide significant implications for the firm's marketing strategies such as bundling, pricing, display and so on. In addition, this research can provide significant information for the development of convergence products and related technologies. A convergence product can decrease its market uncertainty, if two products which consumers tend to purchase together are integrated into it. The results

2006년 양돈 질병 발생동향 및 향후 과제

김창섭,Kim, Chang-Seop 대한양돈협회 2006 養豚 Vol.28 No.12