• Journal of The Korean Radiological Technologist Association
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• v.29 no.1
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• pp.221-221
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• 2003

• Electric Engineers Magazine
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• v.219 no.11
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• pp.42-54
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• 2000

얼마전 언론에 보도된 바에 의하면 반도체 공장들의 순간전압저하로 인한 피해가 몇백억원이 될 정도로 극심하다고 한다. 그러나 이것은 빙산의 일각에 불과하며 순가전압저하에 의한 불량제품의 양산과 그에 따른 국가 경쟁력 저하, 생산기기의 정지와 재기동에 따른 인적, 경제적 손실 등을 고려하면 그 피해액은 엄청나게 불어날 것이다.

• Environmental Mutagens and Carcinogens
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• v.22 no.2
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• pp.97-105
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• 2002

Nowadays a huge variety of products that aim to assist to quit smoking or reduce addictive symptoms are developed and manufactured with safety evaluation, but the safety of the most recent products of interest which do not contain tobacco and nicotine, and shape cigarettes is not evaluated and guaranteed relatively. This study was carried out to evaluate the single and repeated dose inhalation toxicity and genotoxicity of H menthol (Nicotine free-tobacco free) herbal cigarettes provided by Cigastop Ltd. in ICR mice. In this study, doses which we determined to expose to mice were 40 cigarettes for 6 hours a day to mice in single dose and 20 (high dose), 10 (middle dose) and 5 cigarettes (low dose) a day for 28 days in repeated dose inhalation toxicity, in vivo chromosome aberration test and micronucleus test. The particulate substances from H menthol herbal cigarettes also were gathered and used in the Salmonella typhimurium/microsome assay (Salmonella test; Ames test). We could find neither significant changes between control and treatment groups nor dose-response effects of test material at all except serum Ca level of female middle dose treatment group in repeated dose inhalation toxicity test. In conclusion, H menthol herbal cigarettes, when applied clinically intended dose we used, might not show any toxic and/or mutagenic effect.

• Environmental Mutagens and Carcinogens
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• v.22 no.2
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• pp.125-132
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• 2002

To evaluate the modifying effect of Kwao Kreu, Pueraria mirifica (PM) well-known as a rejuvenating folk medicine from Thailand, peri- and post-natal studies were carried out in rats. PM extract was administered to pregnant Sprague Dawley (SD) rats by oral gavage from gestation 6 (GD 6) to postnatal day 21 (PND 21). The amount of administered in this study was 0.042, 0.42 and 4.2 mg/kg/day, respectively. There were no treatment related changes of dams in deaths, clinical signs, and parturition. Treatment related changes in body weight, food consumption and lactation of dams were not observed. F1 fetuses in external abnormality, physical development, reflex/sensory functions and behavioral development were not found. No adults and F1 fetuses in organ weight was found with the exception of vagina and uterus of F1 fetuses. The results showed that PM extract, up to 4.2 mg, had no adverse effects on the peri- and post-natal development of rats. Therefore, PM extract has no adverse effects on peri- and post-natal development of rats.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.168-168
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• 2011

정보화 사회가 도래함으로 개인별 정보 이용량이 급격히 증가하였고 스마트폰과 같은 모바일 기기의 개발로 정보 이용량이 최고치를 갱신 중이다. 이러한 흐름 속에 사람들은 빠른 처리 속도와 고도의 저장 능력을 요구하게 되고 이에 따라 새로운 Random Access Memory에 대한 연구가 활발히 진행되고 있다. 현재 Dynamic Random Access Memory (DRAM)가 눈부신 발전과 성과를 이룩하고 있지만 전원 공급이 중단 될 경우 저장된 내용들이 지워진다는 단점을 가지고 있다. DRAM의 장점에 이러한 단점을 보완할 수 있는 차세대 반도체 소자로 주목 받고 있는 것이 Magnetic Random Access Memory (MRAM)이다. DRAM에서 Capacitor와 유사한 기능을 하는 MTJ stack은 tunneling magnetoresistance (TMR) 현상을 나타내는 자기저항 박막을 이용하여 MRAM 소자에 집적된다. 본 연구에서는 MRAM의 자성 재료로 구성된 MTJ stack을 효과적으로 식각하고 우수한 식각 profile을 얻는 동시에 재증착의 문제를 해결하는데 목적을 둔다. 본 IrMn 자성 박막의 식각 연구는 유도결합 플라즈마 반응성 이온 식각 (Inductively Coupled Plasma Reactive Ion Etching: ICPRIE)법을 이용하여 진행되었다. 특히 본 연구에서는 종래의 $Cl_2$, $BCl_3$ 그리고 HBr과 같은 부식성 가스가 아닌 부식성이 없는 $CH_4$가스를 선택하여 그 농도를 변화시키면서 식각하였고 더 나아가 $O_2$를 첨가하면서 그 효과를 극대화하려고 시도하였다. IrMn 자성 박막의 식각 속도, TiN 하드 마스크에 대한 식각 선택도 그리고 profile 등이 조사되었고 최종적으로 X-ray photoelectron spectroscopy (XPS)를 이용하여 식각 메카니즘을 이해하려고 하였다.

• Journal of KIISE:Computer Systems and Theory
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• v.34 no.4
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• pp.132-137
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• 2007

A point-wise car-like robot moving in the plane changes its direction with a constraint on turning curvature. In this paper, we consider the problem of computing a shortest path of bounded curvature between a prescribed initial configuration (position and orientation) and a polygonal goal, and propose a new geometric proof showing that the shortest path is either of type CC or CS (or their substring), where C specifies a non-degenerate circular arc and S specifies a non-degenerate straight line segment. Based on the geometric property of the shortest path, the shortest path from a configuration to a polygonal goal can be computed in linear time.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.10a
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• pp.511-513
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• 2022

Digital Health Care is the convergence of ICT and (non)medical technology, emphasizing the importance of prevent and monitoring health management in terms of new challenging medical paradigm: predictive, preventive, personalized and participatory. Beyond the limited medical industry of long-term care insurance, it is emerging that AI, IoT, Big Data related new services with new technologies in the 4^th revolution era. It is also noted that business field based on test bed is emergent; Caring Robot, wearable devices need to be launched in the market. Diverse service is possible with Big Data and AI etc.

• Proceedings of the Korean Society of Computer Information Conference
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• 2022.07a
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• pp.307-310
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• 2022

4차 산업혁명의 기술이 발전함에 따라 세계는 눈부시게 발전하고 있다. 그러나 그와 동시에 어르신들의 치매로 인한 사회적 비용의 증가로 발생하는 문제점 또한 무시하지 못할 수준에 이르렀다. 이에 조기에 치매를 선별하여 예방하는 것이 중요시되었으며 다양한 연구기관에서는 빠르고 쉽게 치매의 전 단계인 경도인지장애를 선별하고자 여러 선별 검사지를 제작하여 경도인지장애 선별을 통한 치매를 예방하는 데 노력하는 중이다. 하지만 다양한 상황으로 각각의 효율성이 경도인지장애 선별에 대한 기대에 미치지 못하고 있다. 그리하여 본 연구는 기존에 개발된 경도인지장애 선별지 들을 비교 분석 및 코로나 상황에 적합하게 비대면 방식으로 경도인지장애 선별이 가능하도록 보다 효율적으로 개선하였으며 이를 IoT 기기에 접목하였다. 또한 IoT 기기는 어르신들의 경도인지장애 선별검사에 대한 부담감을 줄이고자 친근한 인형 형태로 개발하였으며 상호작용을 위한 기능 제작을 통하여 마음 돌봄 서비스를 구현하였다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.5 no.1
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• pp.118-124
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• 2001

In this paper, we proposed the novel digital watermarking for color still image using the characteristics of human visual system and the distribution of DCT coefficients. We insert watermark signal in the chromatic components of YCrCb color space according the characteristics of the human visual system that chromatic component are less sensitive than achromatic components. In order to extract the watermark signal, we use the relationship among the DCT coefficients of watermarked image without using original one. Simulation results show that the proposed watermarking method is better quality on invisibility than the conventional methods.

• Current Industrial and Technological Trends in Aerospace
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• v.6 no.1
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• pp.82-89
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• 2008

In this paper a survey was conducted to find out the current components of bipropellant propulsion system for geosynchronous satellites. The purpose of the survey is to list up the alternative components corresponding to the components of chemical propulsion system (CPS) of the communication, ocean, and meteorological satellite (COMS), so that the criterion of survey is whether the alternative components can be applicable to COMS CPS or not. The survey results are described in component-by-component way and the short descriptions of each component and its companies are added. This paper can be useful for beginning a market survey and have a good understanding of the components of bipropellant propulsion system.