• Advances in aircraft and spacecraft science
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• 제7권2호
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• pp.91-113
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• 2020

This paper analyzes the terminal descent phase of a space lander on a surface of a celestial body. A multibody approach is adopted to build the physical model of the lander and the surface. In this work, a legged landing gear system is considered. Opportune modelling of the landing gear crashbox is implemented in order to accurately predict the kinetic energy. To ensure the stability of the lander while impacting the ground and to reduce the contact forces that arise in this maneuver, the multibody model makes use of a co-simulation with a dedicated control system. Two types of control systems are considered; one with only position variables and the other with position and velocity variables. The results demonstrate the good reliability of modern multibody technology to incorporate control algorithms to carry out stability analysis of ground impact of space landers. Moreover, from a comparison between the two control systems adopted, it is shown how the velocity control leads to lower contact forces and fuel consumption.

• 중환자간호학회지
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• 제14권3호
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• pp.1-13
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• 2021

Purpose : This study aims to provide basic data for effective nursing interventions and improvement of nurses' work by exploring their work experiences in single-room-structured intensive care units (ICU) through focus group interviews. Methods : Data were collected through two focus group discussions conducted from March to November 2020 with 13 ICU nurses. Interviews were audio-recorded and analyzed thematically by investigators. Results : Through content analysis, 15 sub-categories and 6 categories were formed. Two themes, "positive experiences patients care in an independent space" and "difficulties in nursing work according to space separation of patients" emerged. There are positive aspects of single-room-structured ICUs, but it was found that practicing nurses had difficulties and required specialized nursing competencies. Therefore, efforts to reduce the burden of nurses in single-room-structured ICUs are necessary. Conclusion : The limitation of this study is that it was conducted in a single hospital because single-room-structured intensive care units are uncommon in Korea. However, this study is of great significance as a basis for establishing guidelines on the efforts required from nurses, hospitals, and governments single-room-structured ICUs in the future.

• 한국실내디자인학회:학술대회논문집
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• 한국실내디자인학회 2006년도 춘계학술발표대회 논문집
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• pp.278-283
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• 2006

For the company, the office space is the expensive resource next to human resource. Employees are under the influence of physical characters of the office space. Among them lighting is the most effective factor in physical, biological and psychological for employees. Although there are lots of investments in architectural aspect of the office space, there is almost no investment and consideration about the lighting environment. Therefore this study was trying to find out these things as follow. First, evaluate lighting environment of people who works in the office spaces. Second, find out which factors are more affective in evaluation of lighting environment. And then with these findings this study found what should be considered as important in lighting planning of the office space. As the result of this study, however the majority of the employees are satisfied with current lighting conditions, they are not satisfied with individual operation of lighting. And in office space work type and position changes by age can affect in a large degree more than other factors. Therefore when planning lighting of the office space, it is necessary to figure out work features of Individual and group exactly and accept the difference by positions appropriately.

• 한국주거학회논문집
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• 제16권1호
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• pp.65-72
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• 2005

With the changing consciousness of community people and the rising standard of living, there has recently been an emphasis on the creation of public facilities' new functions and their role as local community facilities. This changing trends are accordingly requiring a change in spatial structure of the public facilities. In this study, an analysis was conducted with 24 public facilities situated in the Buk-gu district of Daegu to identify the adequacy of their space scale after functional variation. The results of this study are summarized as follows. 1) The site area of public facilities has been being widened after functional variation since more spaces are needed to provide an outdoor resting space with community people, expand a parking space, and operate a community center. 2) The factors that had a direct effect on the change in the use of space are the reduced space for administrative work and the expanded scope of the community center's function. Specifically, the areas of activities for civil service and administrative work and for reserve forces have been reduced due to reduction of function, and floor division by each function group has been becoming stricter due to addition of a community center's function. 3) It was shown that in terms of the space for functions of public facilities, spaces for civil service and waiting have increased mostly after function variation. After functional variation, the scale of spaces for civil service and administrative work has been being planned within the range of $200\~300 m^2$, regardless of the number of population to be covered by public facilities. 4) The space for public use is showing the greatest increase in public facilities which have been built after functional variation. The major factors seem to be the increased moving passages, the expanded convenient facilities for community people, and the increased convenient facilities for disabled. Facilities scale plans have been being made more systematically, compared to the conventional facilities.

• 한국콘텐츠학회논문지
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• 제11권3호
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• pp.241-253
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• 2011

본 논문은 공간디자인 프로세스에서 on-line 기반 아이디어 발상 시스템인 웹스토밍(webstorming) 프로그램을 효과적으로 활용할 수 있는 디자인 프로세스 단계와 방법을 구체화하고 공간디자인에 특화된 아이디어 발상 기반지원시스템을 제안하고자 하였다. 이에 공간디자인 프로세스 단계에서의 활동요소와 웹스토밍 프로그램의 기능요소를 요소상관표로 작성하여 상관성 설문조사에 활용하였고, 요소상관표 작성결과를 시각화하여 관찰-해석-적용의 절차에 따라 분석하였다. 분석결과 공간디자인의 프로세스에서 긴밀한 협업이 이루어지는 계획설계 단계가 가장 높은 상관성을 가짐을 확인하였고, 분업화 작업시점을 기점으로 상관성에 차이가 발생함을 확인하였다. 이에 긴밀한 상관성을 갖는 계획설계 상의 작업에서 사용성을 높일 수 있는 방안으로 '세부 프로세스에 따른 발상매체 제공과 UI 최적화 등'을 제시하였고 이후 분업화 작업 시에도 웹스토밍 시스템의 활용성을 높일 수 있는 개선안을 제시하였다.

• Advances in aircraft and spacecraft science
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• 제5권6호
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• pp.653-669
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• 2018

This work has the objective to analyze multibody mechanisms of inflatable structures for manned space applications. The focus is on the evaluation of the main characteristics of MaxFlex, a new module of MSC Adams including the effect of nonlinear flexible bodies. MaxFlex integrates the nonlinear Finite Element Analysis (FEA) of Nastran-SOL400-and the Adams multibody capabilities in one unique solver, providing an improvement concerning the concept and technology based on the co-simulation among solvers. MaxFlex converts the equations of motion of the nonlinear FEA into phase-space form and discretizes them according to the multibody system integrator framework. The numerical results deal with an inflatable manned space module having rigid components and a flexible coating made of Kevlar. This paper is a preliminary assessment of the computational capabilities of the software and does not provide realistic guidelines for the actual design of the structure. The analysis leads to some recommendations related to the main issues to consider in a nonlinear simulation including both rigid and flexible components. The results underline the importance of realistic deployment times and applied forces. Also, a proper structural modeling is necessary, but can lead to excessive computational overheads.

• 대한수학회논문집
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• 제21권1호
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• pp.17-25
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• 2006

In this paper, we study the right regular representation $R_\Gamma$ of a finite group G on the vector space consisting of vector valued functions on ${\Gamma}/G$ with a subgroup r of G and give a trace formula using the work of M. -F. Vigneras.

• 천문학회보
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• 제38권1호
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• pp.40.1-40.1
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• 2013

The HI ring serendipitously found in the Leo I galaxy group is unique in size in the Local Universe. It is ~200kpc in diameter with MHI~$1.67{\times}109M{\odot}$, surrounding a pair of early type galaxies M105 and NGC 3384. Its origin is still under debate whether it is the remnant of formation of a galaxy group (primordial) or formed from stripped material during galaxy-galaxy interaction (tidal origin). Intriguingly a number of dwarf galaxies have been identified along the gas ring (with or without optical counterpart). Various properties of these dwarf galaxies such as dark matter content, color, and/or metallicity will allow us to pin down the origin of this large scale HI ring. We have obtained a mosaicked CFHT MegaCam image and the EVLA HI cube of the large scale gas ring. In this work we present optical and gas properties of dwarf galaxies identified in the CFHT data.

• 한국조경학회지
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• 제45권4호
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• pp.81-91
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• 2017

본 연구는 효과적인 치유정원 계획에 필요한 치유정원 계획요소의 체계를 세우기 위해 선행 연구문헌을 종합 분석하여 치유정원 계획분야와 계획요소를 도출하고, 전문가 설문을 통하여 치유정원 계획요소의 중요도를 평가하였다. 연구결과는 다음과 같다. 첫째, 5개 계획분야와 19개 계획요소를 도출하였으며, 그 내용은 다음과 같다. $\LARGE{\cdot}$ 계획분야: 물리적 환경, 사회적 환경, 인지적 환경, 기능적 환경, 심리적 환경 $\LARGE{\cdot}$ 계획요소: 식물식재, 정원경관, 수경공간, 그늘공간, 작업공간, 레크레이션공간, 커뮤니티공간, 운동공간, 랜드마크요소, 사인시스템, 안전한 시설물과 재료, 재해안전시설, 유니버설디자인, 접근이 쉬운 동선, 경제적 유지관리, 시각적 개방성, 프라이버시 보장, 휴식공간의 다양성, 예술적 요소 둘째, 계획요소의 중요도 순위 분석 결과, 상위요소로 1순위는 식물식재, 2순위는 재해안전시설, 3순위로는 휴식공간의 다양성이 차지하였고, 하위요소로 예술적 요소와 랜드마크 요소가 각각 18위와 19위로 나타났다. 셋째, 계획요소의 중요도 수준을 평가하여 3개의 그룹으로 분류하였으며, 가장 중요한 A그룹은 식물식재, 재해안전시설이 포함되었고, 다음으로 중요한 B그룹은 휴식공간의 다양성, 커뮤니티공간, 수경공간, 유니버설 디자인, 안전한 시설물과 재료, 경제적 유지관리, 접근이 쉬운 동선, 프라이버시 보장, 정원경관, 작업공간, 시각적 개방성이 포함되었으며, 상대적으로 덜 중요한 C그룹은 그늘공간, 운동공간, 레크레이션공간, 사인시스템, 예술적 요소, 랜드마크 요소가 포함되었다. 그룹의 중요도 1순위의 2개 요소는 치유정원 계획 시에 필수적으로 적용되어야할 요소로 판단되며, 2순위의 11개 요소는 중요하게 고려되어야 하는 요소로 해석된다. 또한, 3순위의 6개 요소는 상대적으로 낮은 중요도 수준을 보여 치유정원 계획 시 설계자가 임의적으로 선택할 수 있는 요소로 판단된다.

• 대한수학회지
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• 제34권3호
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• pp.633-651
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• 1997

For a non-degenerate symmetric bilinear form $\sigma$ on a finite dimensional vector space E, the Jordan algebra of $\sigma$-symmetric operators has a symmetric cone $\Omega_\sigma$ of positive definite operators with respect to $\sigma$. The cone $C_\sigma$ of elements (x,y) \in E \times E with \sigma(x,y) \geq 0$ gives the compression semigroup. In this work, we show that in the sutomorphism group of the tube domain over $\Omega_\sigma$, this semigroup has a UDL and Ol'shanskii decompositions and is exactly the compression semigroup of $\Omega_sigma$.