• Radiation Oncology Journal
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• 제21권2호
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• pp.158-166
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• 2003

목적: 본 연구는 새로운 근접치료선원의 이론적 설계를 통해 출력변조를 이용한 혈관내 방사선치료를 제안한다. 대상 및 방법: 제시된 이론적 선원은 기존의 선원과는 달리 선원물질과 차폐물질(스테인리스 스틸, 또는 텅스텐) 둘 다로 구성되며 이는 방위방향으로 비대칭적 방사선량을 제공할 수 있게 한다. 따라서, 방위방향으로 선원의 방향과 체류시간을 조절함으로써 출력변조를 통한 근접치료가 가능해진다. Novoste Beta-Cath system에서 사용하는 Sr-90/Y 전자방출 선원과 유사한 모양의 두 가지 단순화한 선원을 연구의 대상으로 고려하였다. 첫 번째 선원은 선원물질과 차폐물질이 각각 반씩 차지하며, 두 번째 선원은 1/4은 선원물질로, 나머지 3/4은 차폐물질로 구성된다. 두 선원에 대해 방위 및 방사방향으로의 선량분포를 MCNP 몬테 카를로 코드를 이용하여 계산하였다. 결과: 선원이 혈관내의 중심에 위치하지 않게 되는 가상조건에서의 선량 최적화 계산을 시도한 결과, 혈관내벽에 미치는 선량의 최고치와 최저치의 차이가 87$\%$에서 7$\%$까지 줄어들 수 있음을 보였다. 결론: 본 연구에서 제시된 이론적 선원은 선량적 관점에서의 적합성 여부에 관해 매우 고무적인 결과를 보여 줌으로써 출력변조를 통한 혈관내 근접방사선치료의 가능성을 나타내었다. 본 과제의 다음 단계는 굵기가 가는 맥관 내에서 선원의 위치를 파악하여 그를 방위방향으로 정확하게 회전시킬 수 있는 방사선 전달 체계의 개발이라 할 수 있다.

• 한국진공학회지
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• 제19권3호
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• pp.217-223
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• 2010

유기금속화학기상증착법으로 적층 InAs/$In_{0.1}Ga_{0.9}As$ DWELL (dot-in-a-well) 구조를 성장하여 n-i-n 구조의 적외선 수광소자를 제작하였으며, PL (photoluminescence) 발광 특성 및 암전류 특성을 분석하였다. 동일한 조건으로 양자점을 적층하였을 때 크기 및 밀도의 변화에 의한 이중 PL peak을 관찰하였으며, TMIn의 유량을 조절함으로써 단일 peak을 갖는 균일한 크기의 양자점 적층 구조를 성장할 수 있었다. 적외선 수광소자 구조를 성장함에 있어서, 상부의 n-형 GaAs의 성장 온도가 600도 이상인 경우 PL 발광 세기가 급격히 감소하였고 이에 따른 암전류의 증가를 관찰하였다. 0.5 V 인가 전압에서 암전류의 온도 의존성에 대한 활성화 에너지의 크기는 성장온도가 580도인 경우 106 meV이고, 650도의 경우는 48 meV로 급격이 낮아졌다. 이는 고온의 성장 온도에 의한 InAs 양자점과 $In_{0.1}Ga_{0.9}As$ 양자우물구조 계면에서의 열적 상호 확산에 의하여 비발광 천이가 증가되었기 때문이다.

• 한국주거학회논문집
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• 제19권4호
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• pp.59-69
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• 2008

Based upon the research and analysis on the downtown residents' satisfaction with their current housing areas and preference for future housing areas, this study clarifies the following. First, the breakdown on various factors influencing the housing environment indicates that downtown residents are the most satisfied with the easy access to the public transportation, and cultural and commercial facilities. Second, they are not content with the amenity aspects such as the air, noise, and the surrounding views, and the economic aspects such as the prices of the houses and the prospects for future investment. The low satisfaction suggests that the amenity aspects and economic aspects should be considered for future downtown housing development. Third, more than half of the residents in downtown areas still prefer to dwell in downtown areas. In the future downtown development, the close analysis on the characteristics of downtown dwelling, and the researches on the right direction of downtown housing development for the whole citizens of Daegu should be done in advance. Last, the majority of people wishing to reside in downtown want medium- or large-scale apartment complexes. In the future downtown housing development, it should be focused on the downtown residence with complex functions rather than on the small-scale maintenance projects.

• 한국주거학회:학술대회논문집
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• 한국주거학회 2006년도 추계학술발표대회 논문집
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• pp.337-340
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• 2006

Dwelling refers to a way of being that has to do with a cautious and guarded attitude. What has to be nurtured and preserved is the dweller's relationship with the fourfold of heaven and earth, divinities and mortals. This leads to the fourfold definition that mortals dwell insofar as they save the earth, receive heaven as heaven, await the divinities as divinities, and are capable of death as death. Heidegger sees the thing as the concrescence of what he calls the fourfold of earth, sky, mortals, and divinities. For Heidegger, true being means to be open to the fourfold, to tend the fourfold in its essence. C. Norberg-Schulz takes as his starting point Heidegger's notion of the thing as that in which the fourfold is assembled. The built space must be organized in a way that concrete places are created, places that are characterized by a specific genius loci. This idea refers to life in the warm seclusion of a traditional community, but is much less applicable to the functional networks and relationships that determine life in a modem society. Cacciari thinks that what is worth questioning is in particular the condition of homelessness perceived by Heidegger, and the possible consequences of this situation for architecture. The aim of this paper is to study the meaning of dwelling through Heidegger's concept of dwelling and the interpretations of C. Norberg-Schulz and M. Cacciari about it.

• 한국가구학회지
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• 제24권1호
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• pp.1-14
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• 2013

Since the 1980s the development of American art furniture was embodied its concept by second-generation furniture artists affected and educated from the first generation that has implanted art furniture fundamental values. Besides, embracing inevitably needs of the new era going with the social change rather than dwell on the nature of mere handicraft era, it has evolved with economic revival in the United States, the attention and increased consumption of the public, and ongoing government-sponsored. And more recently, the American contemporary Art Furniture faces another change in the non-boundary phenomena between art and design. American art furniture since the 1980s are summarized as three major trends: Art furniture embellished with traditional hand-craft, Art furniture featured the individualistic avant-guard characteristic, Art furniture eroded the distinction between art and design. By analyzing focusing on the furniture artists and their works in contemporary art furniture deployment aspects since the 1980s, the purpose of this study can be utilized as a method to measure the forward direction, internationally competitive, creativity, and artistic value of the domestic art furniture.

• 한국전문물리치료학회지
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• 제16권4호
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• pp.44-52
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• 2009

It is known that individual factors as cognitive, perception, emotion, and motivation may greatly influence on recovery from neurologic region. This study was to investigate the effects of environmental reinforcement through motivation to perform the tasks voluntarily on motor and cognition function in rats with focal ischemic brain injury. Focal ischemic brain injury was induced in Sprague-Dawley rats (15 rats, $250{\pm}50$ g) through middle cerebral artery occlusion (MCAo). And then, experiment groups were randomly divided into three groups; The control group: MCAo induction ($n_1$=5), the environmental reinforcement (ER) group: the application for ER after MCAo induction ($n_2$=5), the environmental reinforcement through motivation (ERM) group: the application for ERM after MCAo induction ($n_3$=5). The climbing test (CT) and the modified limb placing tests (MLPTs) to measure the motor function and the Morris water maze acquisition test (MWMAT) and the Morris water maze retention test (MWMRT) to measure the cognitive function were performed. For the CT, the ERM group was significantly larger than the ER group. For the MLPTs, the ERM group was significantly decreased compared to other groups. For the MWMAT, the time to find the circular platform in the ERM group significantly decreased compared to other groups. For the MWMRT, the time to dwell on the quadrant circular platform in the ERM group was significantly increased compared to other groups. These results suggested that the ERM could improve the motor and cognitive functions in the rats with focal ischemic brain injury.

• Safety and Health at Work
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• 제6권2호
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• pp.146-150
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• 2015

Occupational health and safety (OHS) is a broad field of professional practice, which involves specialists from different disciplines including but not limited to engineers, occupational health physicians, physical and biological scientists, economists, and statisticians. The preventive systems required to ensure workers are protected from injuries and illnesses dwell heavily on engineers; however, the extent to which the engineer can go regarding planning and implementing preventive measures is dependent on specific legal requirements, leadership commitment from the company, organization, and nation. The objective of this paper is to identify the areas of opportunities for improvements in OHS management in Ghana with regard to the nation's legal requirements, commitment of the Ghana government, and Ghanaian leadership as well as appropriate structuring of Ghanaian institutions responsible for monitoring and managing OHS in Ghana. This paper identified Ghana's fragmented legal requirements concerning OHS, which are under different jurisdictions with unclear responsibilities and accountabilities. The paper also highlights the training needs of Ghanaian academic institutions regarding OHS. Among other recommendations made including structuring of Ghanaian institutions to manage OHS in line with the ILO-OSH 2001, this paper aligns the recommendations with the articles and elements of International Labour Organization convention number 155 and OHSAS 18001 elements.

• 한국결정성장학회지
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• 제24권4호
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• pp.151-157
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• 2014

The degradation mechanisms of thermal barrier coatings (TBCs) were investigated in different thermal fatigue condition in terms of microstructural analyses. The isothermal and cyclic oxidation tests were conducted to atmospheric plasma sprayed-TBCs on NIMONIC 263 substrates. The delamination occurred by the oxide layer formation at the interface, the Ni/Cr-based oxide was formed after Al-based oxide layer grew up to ${\sim}10{\mu}m$ in the isothermal condition. In the cyclic oxidation with dwell time, the failure occurred earlier (500 hr) than in the isothermal oxidation (900 hr) at same temperature. The thickness of Al-based oxide layer of the delaminated specimen in the cyclic condition was ${\sim}4{\mu}m$ and the interfacial cracks were observed. The acoustic emission method revealed that the cracks generated during the cooling step. It was considered that the specimens were prevented from the formation of the Al-based oxide by cooling treatment, and the degradation mode in the cyclic test was dominantly interfacial cracking by the difference of thermal expansion coefficients of the coating layers.

• 한국ITS학회 논문지
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• 제13권1호
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• pp.53-60
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• 2014

차량과 같이 넓은 범위를 이동하는 환경에서 무선 인터넷 서비스를 사용할 때, 불필요하게 발생하는 핸드오버는 서비스 품질 저하의 주된 요인이다. 본 논문에서는 차량이 일정한 이동패턴을 갖고 있을 때, 핸드오버 빈도를 줄일 수 있는 방안을 제시한다. 차량의 이동 패턴을 Discrete-Time Markov Chain (DTMC)으로 모델링하고, AdaBoost 기법을 이용하여, 각 셀 내의 체류시간과 평균 신호의 세기를 저장하고 분석하여 핸드오버 시, 적합한 목적지 셀을 정하도록 한다. 제안한 방안의 검증을 위해, 서울 시내버스 노선들을 기반으로 성능 평가를 수행하였으며, 결과로 기존의 핸드오버 기법보다 핸드오버의 빈도를 줄이며, 평균 처리율 (throughput)은 비슷한 레벨로 유지할 수 있었다.

• 한국실내디자인학회논문집
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• 제23권2호
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• pp.80-89
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• 2014

0 and 1, two digits are principle and formality of digital media. Those principle and formality dwell in new media paradigm. They are founded on emergence of new types of space. As describing the relationship originating from the concepts of digital media paradigm and space and discussing their characteristics, this paper presents the grounds for a theoretical argument for formation of new space. The concept of virtuality which mimics and represents the real, non-linearity which resembles human system of thinking and sensing, and interactivity connecting the communication theory of human and machine, their properties form the important basis for emergence of a new aspect of space. The concepts of digital media paradigm divide a type of space into two properties. The first is a inner modality. The second is outer modality. Dynamic space implicates inner modality that humans internally recognize the sense of space through their body and sensing organs. Space is not sensed but sensing. Space has an organic nature through object's interaction. Space has an outer nature that is physically variable. Finally, space has properties of modularity that changes structure of space. For empirical basis of an argument, new media art that has architectural form and those spatial characteristics were compared and analyzed. This conceptual discussion for space which the formality of digital media is applied will be an important foundation for create space design.