• 천문학회지
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• 제36권3호
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• pp.177-187
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• 2003

Active galactic nuclei (AGNs) are distant, powerful sources of radiation over the entire electromagnetic spectrum, from radio waves to gamma-rays. There is much evidence that they are driven by gravitational accretion of stars, dust, and gas, onto central massive black holes (MBHs) imprisoning anywhere from $\~$1 to $\~$10,000 million solar masses; such objects may naturally form in the centers of galaxies during their normal dynamical evolution. A small fraction of AGNs, of the radio-loud type (RLAGNs), are somehow able to generate powerful synchrotron-emitting structures (cores, jets, lobes) with sizes ranging from pc to Mpc. A brief summary of AGN observations and theories is given, with an emphasis on RLAGNs. Preliminary results from the imaging of 10000 extragalactic radio sources observed in the MITVLA snapshot survey, and from a new analytic theory of the time-variable power output from Kerr black hole magnetospheres, are presented. To better understand the complex physical processes within the central engines of AGNs, it is important to confront the observations with theories, from the viewpoint of analyzing the time-variable behaviours of AGNs - which have been recorded over both 'short' human ($10^0-10^9\;s$) and 'long' cosmic ($10^{13} - 10^{17}\;s$) timescales. Some key ingredients of a basic mathematical formalism are outlined, which may help in building detailed Monte-Carlo models of evolving AGN populations; such numerical calculations should be potentially important tools for useful interpretation of the large amounts of statistical data now publicly available for both AGNs and RLAGNs.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2005년도 하계학술대회 논문집 Vol.6
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• pp.236-237
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• 2005

To measure surface roughness and smoothness of semiconducting materials in power cable, we have investigated the formation and growth process of carbon black showed by changing the content of carbon black. The specimens were primarily kneaded in material samples of pellet form for 5 minutes on rollers ranging between 70[$^{\circ}C$] and 100[$^{\circ}C$]. Then they were produced as sheets after pressing for 20 minutes at 180[$^{\circ}C$] with a pressure of 200[kg/cm]. The contents of conductive carbon black were the variable, and their contents were 20, 30 and 40[wt%], respectively. The surface roughness and smoothness of specimens were measured by SEM and AFM. From SEM experimental result, carbon black in specimens formed matrix as a particles. Also we showed growth process of carbon black according to an increment of the content of carbon black. From AFM experimental result, surface roughness of specimens decreased according to an increment of the content of carbon black.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2018년도 춘계 학술논문 발표대회
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• pp.212-213
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• 2018

The cementitious composites have been developed to satisfy various demands of the construction market. The conductive concrete, which is a carbon-based cementitious composite, was used for the deicing or the detecting the internal crack. The cement-based battery is a technology that applies the basic concept of the alkaline battery to these conductive concretes. The cementitious composites could have a function as batteries, through a mixing of anode and cathode, which were consist of the zinc and manganese dioxide powder. The carbon-based materials, which have a significant effect on electrical properties, could be considered as the main variable in cement-based batteries. Therefore, in this study, the effects of carbon-based materials were investigated. Two types of materials, including the Carbon black and Multi-walled carbon nanotube(MWCNT), were considered as the main variables. From the experiment results, the electrical characteristics such as resistance, voltage, and current were compared according to the age.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 하계학술대회 논문집 Vol.7
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• pp.218-219
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• 2006

To Smoothness of semiconducting materials in power cable, we have investigated those of semiconducting materials showed by changing the content of carbon black and Carbon Nanotube. Then they were produced as sheets after pressing for 20 minutes at $180^[{\circ}C]$ with a pressure of $200[kg/cm^2]$. The content of conductive carbon black and Carbon Nanotube was the variable, and their contents were 20-40[wt%] and 2-6[wt%] respectively. The smoothness was measured by JSM-6400.

• 한국동물위생학회지
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• 제13권1호
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• pp.44-48
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• 1990

This study was based on 3 necropsies of patients affected with Balantidium coli dysentery from two pig farms. Grossly, the lesions involved the large intestine from cecum to rectum. Many variable-sized ulcers were diffusely scattered on the mucosa of the cecum and the colon which were covered with a necrotic, grayish white, slate black, or black membrane. The mucosa affected reddened and swollen. Microscopically, numerous balantidia penetrated In the mucosa of the colon and there they induced necrosis and desquamation of the epithelial cells, where inflammatory cells such as macrophages, neutrophils, eosinophils, lymphocytes and plasma cells were infiltrated.

• 경영과정보연구
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• 제36권4호
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• pp.103-116
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• 2017

본 연구의 목적은 서비스 산업에서 고객의 '블랙컨슈머 행동'을 지각한 종사원이 조직에 미치는 부정적 행동인 '조직일탈행동'에 미치는 영향과 조직내 '격려'의 조절효과를 분석을 통해 관리적 시사점의 제공이다. 특히, Adler(1991)는 격려가 개인의 인지적 도식 틀에 긍정적 기대를 주입하는 것으로 인지, 정서, 행동에 긍정적 영향을 미친다고 주장(Dinkmeyer and Losoncy, 1996)하였다. 이러한 Adler(1991) 주장을 근거로 고객의 블랙컨슈머 행동을 지각한 노동자의 반응행동에 대한 격려의 조절효과를 실증적으로 분석하였다. 선행연구를 바탕으로 블랙컨슈머 행동, 조직일탈행동, 격려에 대한 연구모형을 설계하였다. 2015년 11월 15일부터 12월 3일까지 부산지역 호텔, 카지노, 면세점 그리고 외식 서비스 종사원 323명을 대상으로 설문지를 배포하였다. 그 중 279부를 회수(회수율은 86.4%)하였고, 회수된 설문지 중에서 무성의한 응답 또는 무응답이 많은 부실응답 설문지를 제외하여 262부를 최종 분석에 사용하였다. 실증분석 결과 블랙컨슈머 행동은 조직일탈행동에 유의한 영향을 미치고, 격려는 블랙컨슈머 행동 중 과도성과 조직일탈행동에 대한 유의적인 조절효과가 있다는 결과를 확인할 수 있었다. 이러한 실증분석 결과를 바탕으로 블랙컨슈머에 노출된 서비스 노동자에 대한 관리적 시사점을 제공하였다.

• 복식문화연구
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• 제19권3호
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• pp.556-564
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• 2011

The purpose of this study was to analyze the effect of the structural properties, the color characteristics and the texture of sight and touch on the tactile preferences for the black fabrics. Male and female university students were asked to evaluate the texture of sight and touch and tactile preference to the nine different black fabrics which were selected on the basis of the previous research results. Data were analyzed by using frequency analysis, mean, factor analysis, t-test, F-test, correlation and regression analysis. The texture of sight and touch for black fabrics was classified into four factors: smoothness, bulkiness, extensibility, firmness. This texture of sight and touch factors showed a significant correlative relationship to the structural properties and color characteristics of the black fabrics. There were significant differences according to black fabrics on the point of texture of sight and touch. The velvet was evaluated the most smooth fabric, while the velvet and fake leather were evaluated the most bulky fabrics. Also, the jersey and lace fabrics were evaluated the most extensible fabrics, while the melton was evaluated as the most firm fabrics. There were significant correlative relationships not only between the structural properties and the texture of sight and touch but also between the color characteristics and the texture for black fabrics. Also, among the structural properties, the color characteristics and the texture of sight and touch of black fabrics, major variable factor of influencing on the tactile preference was turned out to be the texture of sight and touch.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제54권10호
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• pp.443-448
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• 2005

To measure modulus, damping properties and smoothness of semiconducting materials in power cable, we have investigated those of semiconducting materials showed by changing the content of carbon black. Then they were produced as sheets after pressing for 20 minutes at 180[$^{\circ}C$] with a pressure of 200[kg/cm$^{2}$]. The content of conductive carbon black was the variable, and their contents were 20, 30 and 40[wt$\%$], respectively. The modulus and tans were measured by DMA 2980. The ranges of measurement temperature were from -50[$^{\circ}C$] to 100[$^{\circ}C$] and measurement frequency was 1[Hz3. The modulus of specimens was increased according to a increment of a carbon black content. And modulus was rapidly decreased at the glass transition temperature. The tans of specimens was decreased according to a increment of a carbon black content. The smoothness was measured by JSM-6400. EEA resin from SEM measurement was best the dispersion of carbon back in base resin.

• Communications for Statistical Applications and Methods
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• 제29권2호
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• pp.251-261
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• 2022

As AI has a wide range of influence on human social life, issues of transparency and ethics of AI are emerging. In particular, it is widely known that due to the existence of historical bias in data against ethics or regulatory frameworks for fairness, trained AI models based on such biased data could also impose bias or unfairness against a certain sensitive group (e.g., non-white, women). Demographic disparities due to AI, which refer to socially unacceptable bias that an AI model favors certain groups (e.g., white, men) over other groups (e.g., black, women), have been observed frequently in many applications of AI and many studies have been done recently to develop AI algorithms which remove or alleviate such demographic disparities in trained AI models. In this paper, we consider a problem of using the information in the sensitive variable for fair prediction when using the sensitive variable as a part of input variables is prohibitive by laws or regulations to avoid unfairness. As a way of reflecting the information in the sensitive variable to prediction, we consider a two-stage procedure. First, the sensitive variable is fully included in the learning phase to have a prediction model depending on the sensitive variable, and then an imputed sensitive variable is used in the prediction phase. The aim of this paper is to evaluate this procedure by analyzing several benchmark datasets. We illustrate that using an imputed sensitive variable is helpful to improve prediction accuracies without hampering the degree of fairness much.

• 대한인간공학회:학술대회논문집
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• 대한인간공학회 1997년도 추계학술대회논문집
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• pp.109-113
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• 1997

The purpose of this study is to survey colors of background, marker, and pointer being used in passenger car's display panel, and to suggest ergonomic design guidelines of car's display panel to enhance driver's visibility. An experiment was conducted, in which reading time of display was measured as dependent variable, and colors of black, white, blue and green were selected as background colors of display, and black, white, yellow, and green as marker's colors, and black white, yellow, green and red as pointer's colors. The results showed that reading time of display with white background, yellow marker and pointer was shortest. It was expected that this results could be used as valuable design guidelines in car's display panel.