• 제목/요약/키워드: Nature Environment

검색결과 2,232건 처리시간 0.027초

The Simulation and Research of Information for Space Craft(Autonomous Spacecraft Health Monitoring/Data Validation Control Systems)

  • Kim, H;Jhonson, R.;Zalewski, D.;Qu, Z.;Durrance, S.T.;Ham, C.
    • 한국산학기술학회논문지
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    • 제2권2호
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    • pp.81-89
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    • 2001
  • 우주 항공위성 시스템은 변하는 불확실한 우주항공 환경에(서) 운행되고 지상기지국으로부터의 원격통신 없이 장시간 동안 동작해야 할 자율적인 능력이 요구되고, 결함 없이 임무를 수행하여야 하며, 시스템에서 계측된 데이터의 신뢰성을 유지하기 위한 고장 상태 검출과 오류 수정 시스템을 차보하는 것이 중요하다. 본 논문에서는 확장 칼만 필터 기법을 적용한 동적모델 시뮬레이션 기법(High Fidelity, Dynamic Model-based Simulation)을 제안하였으며, 제안된 시스템은 비정상적인 데이터의 효과적인 검출과 대응이 가능해짐으로써 신뢰성 있는 우주항공위성시스템을 구축하도록 자동 상태 진단/데이터 시스템에 고장검출/오류수정 시스템을 적용하는 것이다. (Autonomous Spacecraft Health Monitoring/Data Validation Control System : ASHMDVCS).

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클러스터 컴퓨팅 환경에서 병렬루프 처리를 위한 재구성 가능한 부하 및 성능 균형 방법 (A Reconfigurable Load and Performance Balancing Scheme for Parallel Loops in a Clustered Computing Environment)

  • 김태형
    • 한국정보과학회논문지:컴퓨팅의 실제 및 레터
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    • 제10권1호
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    • pp.49-56
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    • 2004
  • 부하 불균형은 병렬처리에 있어서 좋은 성능을 얻기 위한 주요한 방해 요소 중의 하나이다. 전역(全域) 부하균형 기법은 하나의 응용에서 발생된 병렬 태스크를 취급하는데 적절하지 않다. 동적 루프 스케줄링 기법은 공유 메모리 멀티프로세서 병렬구조에서 병렬 루프의 부하균형에 효과적인 것으로 알려져있다. 하지만 이 기법의 중앙집중적 특성은 워크스테이션 클러스터 환경에서 프로세서 수가 상대적으로 많지 않은 경우에도 병목현상을 일으킬 수 있는 요인이 된다. 워크스테이션 클러스터 환경에서의 통신 오버헤드는 공유 메모리 멀티프로세서 병렬 구조와 비교할 때 수십배의 차이가 생기기 때문이다. 더구나 병렬 루프에서 발생하는 단위 태스크가 불규칙적인 작업량을 갖는 경우에는 기본 루프 스케줄링 기법의 단점을 보완한 개선된 방법들을 적용할 수가 없다. 본 논문에서는 이러한 불규칙적인 작업량을 갖는 병렬루프를 서로 다른 성능을 갖는 워크스테이션들의 네트워크 환경에서 효율적으로 부하를 분배하기 위한 재구성 가능한 분산 부하 균형 기법을 제시한다. 이러한 재구성 가능한 기법은 전통적인 부하균형 방법과 함께 성능균형을 가능하게 함으로써 전체수행시간을 최소화할 수 있음을 보였다.

${\cdot}$중등 교사들의 요통발생 특성에 관한 비교분석 (Comparative Analysis, of Characteristics of Lumbago Among Teachers of Elementary and High Schools)

  • 전제균;김상수
    • The Journal of Korean Physical Therapy
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    • 제6권1호
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    • pp.37-48
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    • 1994
  • In order to grasp the occupational add social characteristics of the onset of lumbago among elementary and high school teachers, 423 elementary and high school teachers were taken as subjects of study through questionaires. The following are the results of the study which were analyzed through data, conducted for one month in the City of Taegu, between Jun. 90, and Jul. 20 of 1993: 1. the incidence of lumbago of the entire teachers was $75.2\%$, with the elementary school teacher$(81.9\%)$ higher than high school teacher$(70.6\%)$. 2. In the relationship between the characteristics of job and lumbago. characteristics of teaching, monthly income, chores and satisfaction with job did not show significance, but weekly teaching hours, mental stress and the degree of comfort of chair reflected significantly(p<0.01). 3. In social relationship, personal nature, sleeping hours and place, smoking and drinking did not hold significance, but daily average walking hours, posture during sleep, general health conidition(p<0.01) and daily average riding hours and regular exercise(p<0.05) etc. showed significant relationships. 4. In the sistuation of lumbago of the teacher groups, no significant differences wee found in the cause of lumbago, duration of lumbago, sick leaves and recognigion of lumbago, but it was contrary in the treatment of lumbago(p<0.01). Based on the above results, lumbago is closely related to occupational and social factors, the prevention and treatment can be diversified based on occupation and environment. Consequently, regular educational program is considered imperative mainly on prevention of lumbago by putting aside time for such purpose.

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이웃관계 개선을 위한 사회적 공간활용 개선계획에 관한 연구 - 편복도 아파트를 중심으로 - (A Study on Social Space Utilizing Improvement Plan for Neighbor Relation Improvement - Focusing on One-pass age Walkway Apartment -)

  • 박재영;최상헌
    • 한국실내디자인학회:학술대회논문집
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    • 한국실내디자인학회 2006년도 춘계학술발표대회 논문집
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    • pp.210-214
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    • 2006
  • Along with the development of industrious society, the shape of city and the way of life have changed in accordance. The development of the city deepened gravitation of the city population, leading to the lack of housing and land, and apartment complexes became an alternative way of securing a number of families into a small space of land. Apartment can have a lot of families reside In a small space of land, and it can also be satisfactory to individual's privacy and anti-crime measures. On the other hand, there are negative problems with it. Among them, contacts with neighboring people showed that they only greeted each other when they met in the walkway. As shown in this, one of the reasons that there is a lack of friend ship activities is because there is short of space for common use. And in comparison to those of stairway walkway, apartments with one-passage walk way showed a higher level of contacts with neighbors. It is assumed that apartments with one-passage walk way have more chances to meet neighbors than do those of stairway walkway. This study analyzed the phases appearing in neighbor relations through investigation of the literature, and presented a coping measure. One solution is to prepare flower beds from the outside of walkway by enlarging the width of the walkway in apartments with one-passage walk way, and providing benches in front of flower beds so that residents can take a rest there. The more often residential people take a rest there, the more frequently they can meet each other. Accordingly this can solve problems of contacts with neighbors and the dreary scene of walkway can become a wider view in a nature friendly environment, bringing them to an active acquaintance activities.

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Detecting the Honeycomb Sandwich Composite Material's Moisture Impregnating Defects by Using Infrared Thermography Technique

  • Kwon, Koo-Ahn;Park, Hee-Sang;Choi, Man-Yong;Park, Jeong-Hak;Choi, Won-Jae
    • 비파괴검사학회지
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    • 제37권2호
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    • pp.99-105
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    • 2017
  • Many composite materials are used in the aerospace industry because of their excellent mechanical properties. However, the nature of aviation exposes these materials to high temperature and high moisture conditions depending on climate, location, and altitude. Therefore, the molecular arrangement chemical properties, and mechanical properties of composite materials can be changed under these conditions. As a result, surface disruptions and cracks can be created. Consequently, moisture-impregnating defects can be induced due to the crack and delamination of composite materials as they are repeatedly exposed to moisture absorption moisture release, fatigue environment, temperature changes, and fluid pressure changes. This study evaluates the possibility of detecting the moisture-impregnating defects of CFRP and GFRP honeycomb structure sandwich composite materials, which are the composite materials in the aircraft structure, by using an active infrared thermography technology among non-destructive testing methods. In all experiments, it was possible to distinguish the area and a number of CFRP composite materials more clearly than those of GFRP composite material. The highest detection rate was observed in the heating duration of 50 mHz and the low detection rate was at the heating duration of over 500 mHz. The reflection method showed a higher detection rate than the transmission method.

Effect of Distribution System Materials and Water Quality on Heterotrophic Plate Counts and Biofilm Proliferation

  • 장영철;정권
    • Journal of Microbiology and Biotechnology
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    • 제14권6호
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    • pp.1114-1119
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    • 2004
  • The biofilms on pipe walls in water distribution systems are of interest since they can lead to chlorine demand, coliform growth, pipe corrosion, and water taste and odor problems. As such, the study described in this paper is part of an AWWARF and Tampa Bay Water tailored collaboration project to determine the effect of blending different source waters on the water quality in various distribution systems. The project was based on 18 independent pilot distribution systems (PDS), each being fed by a different water blend (7 finished waters blended in different proportions). The source waters compared were groundwater, surface water, and brackish water, which were treated in a variety of pilot distribution systems, including reverse osmosis (RO) (desalination), both membrane and chemical softening, and ozonation-biological activated carbon (BAC), resulting in a total of 7 different finished waters. The observations from this study consistently demonstrated that unlined ductile iron was more heavily colonized by a biomass than galvanized steel, lined ductile iron, and PVC (in that order) and that the fixed biomass accumulation was more influenced by the nature of the supporting material than by the water quality (including the secondary residual levels). However, although the bulk liquid water cultivable bacterial counts (i.e. heterotrophic plate counts or HPCs) did not increase with a greater biofilm accumulation, the results also suggested that high HPCs corresponded to a low disinfectant residual more than a high biofilm inventory. Furthermore, temperature was found to affect the biofilms, plus the AOC was important when the residual was between 0.6 and 2.0 mg $Cl_2/l$. An additional aspect of the current study was that the potential of the exoproteolytic activity (PEPA) technique was used along with a traditional so-called destructive technique in which the biofilm was scrapped off the coupon surface, resuspended, and cultivated on an R2A agar. Both techniques indicated similar trends and relative comparisons among the PDSs, yet the culturable biofilm values for the traditional method were several orders of magnitude lower than the PEPA values.

공익포스터의 공감각적 표현 연구 (A Study of Synesthesia Used in Public Advertising)

  • 이려;김맹호
    • 한국콘텐츠학회논문지
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    • 제17권10호
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    • pp.624-635
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    • 2017
  • 공익포스터는 설득 커뮤니케이션을 목적으로 효과적인 메시지를 전달하기 위해 여러 가지 방법을 사용하고 있는데, 그 방법 중 하나로 감성의 표현수단인 공감각적 표현을 통해 보다 적극적인 설득 커뮤니케이션을 하고 있다. 본 연구는 한국방송광고공사 주최 공익 포스터 수상작을 중심으로, 작품 사례분석을 통하여 공익 포스터의 목적인 설득을 위한 커뮤니케이션 수단으로 공감각이 어떻게 적용되었는지 알아보았다. 그 결과에 따르면 첫째, 공감각적 표현이 공익포스터의 효과적인 정보 전달을 극대화 시키는 데에 긍정적인 효과를 나타내고 있다. 둘째, 공익포스터에서 공감각 요소의 비중은 시각, 촉각, 청각, 후각, 미각의 순서로 나타났다. 셋째, 자연 환경 주제인 공익포스터에서 공감각을 효과적으로 표현하기 위하여 시각화된 촉각을 가장 많이 사용하였고, 사회공동체 주제인 공익포스터에서는 시각화된 청각이 가장 많이 사용되었다. 넷째, 공익포스터에서 세 가지 이상의 감각을 활용시킬 때는 가장 강력한 감각자극에 의해 공감각이 효과적으로 전달되었다. 따라서 본 연구의 결과는 향후 이러한 공감각적 표현요소가 주제에 따른 공익포스터에 많이 활용되어 대중에게 효과적인 메시지를 전달시킬 수 있는 학술적 근거가 되기를 기대한다.

대학의 도서관과 전자계산소 및 관련기구의 조직 통합에 관한 연구 (The Study on the Organizational Integration of the Information Related Operations in University)

  • 김성수;김윤실
    • 정보관리학회지
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    • 제14권1호
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    • pp.125-159
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    • 1997
  • 본 연구는 대학의 도서관과 전자계산소 및 관련기구의 조직 통합에 관하여 고찰한 것이다. 1)먼저 이들 정보관련기구들의 조직 통합에 관한 이론적 배경을 살펴보고, 2) 미국과 일본에서의 정보관련기구의 통합 현황을 파악한 다음, 3) 한국에서의 조직통합 유형을 고찰하고, 4) 한국에서의 정보관련기구들의 조직 통합에 관한 사례들을 분석하였다. 그 결과, 대학에서 정보관련 단위기구들의 통합시에는 완전 통합하는 것이 가장 바람직함을 파악할 수 있었다. 또한 새로운 통합기관의 책임자에게 '정보담당부총장' 직위를 부여하는 문제를 중점적으로 논술하였다. 그리고 정보담당부총장은 관련업무를 강력하게 추진할 수 있는 지도력을 발휘 할 수 있어야 비로소 미래 정보사회에서 야기되는 복잡한 문제들을 다양하게 분석하여 그 발전 방향을 제시할 수 있음을 강조하였다. 아울러 결론에서는 향후 국내에서 정보관련기구들의 조직을 통합 설계할 때에 고려하여야 할 사항 등을 집약하여 제시하였다.

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현대 의자 디자인의 특성에 관한 연구 (A Study on the Characteristics of the Modern Chair Design)

  • 신홍경
    • 한국실내디자인학회논문집
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    • 제13호
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    • pp.187-196
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    • 1997
  • A Study on the Characteristics of the Modern Chair Design The features of the modern chair design results from the diverse life style unfolded as per the 20th century social structure and the change of the residential space, and new design has been being developed by the scientists and the artists in various fields through their cooperated work in a way. The field of the scientific or technical study and creation of arts can be developed where they can evoke the sympathy in the circumstances under which the various styles of both arts and science meet across, complement crash together, and grow up. The operation which can control in the network of such pluralistic sphere has been needed for a long period and it has been facing the needs from a time and society. The engineering furniture as the counterplan of the above has brought the value of materials into relief to the forms of human life by making the properties of matter the maximum value or changing it. It can be summarized as following characteristics in its materials and forms along as well as the 3 types (handycrafty, mechanical, and ecological expression) in process through the 20th century. 1. Characteristics in Materials elasticity of the chair as per the changes of the flexibility in the steel pipe development of systematic chair using the plasticity of the plywood, plastic, and wire lightweight due to the materials such as aluminum. 2. Formative characteristics formative simplicity for the increase of the function and the quality improvement such as sociality, productivity, environmental and aesthetic nature emphasis on the structure as per the architectural environment and tecniques pursuit of the forms as a container of the human body seeking for the formative values as the cultural symbols coping with the needs from thepluralistic social structure Furniture is not the makeup for convenience sake but most importantexpression as necessaries of our environments. It should identify itself always as per these kind of needs and also it should be able to used to keep the relation of such mutual division, otherwise the purchase of new furniture should be necessary according to every change of the existing situatiov. Our residence doesn't need the specific style but expresses only the properties of the dwellers.

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생물학적 패턴의 건축적 적용에 관한 연구 (A Study on the Architectural Application of Biological Patterns)

  • 김원갑
    • 한국실내디자인학회논문집
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    • 제21권2호
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    • pp.35-45
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    • 2012
  • The development of digital media made the change of architectural paradigm from tectonic to the surface and pattern. This means the transition to the new kind of materiality and the resurrection of ornament. This study started as an aim to apply biological pattern to architectural design from the new perception of pattern. Architectural patterns in the early era appeared as ladders, steps, chains, trees, vortices. But since 21st century, we can find patterns in nature like atoms and molecular structures, fluid forms of dynamics and new geometrical pattern like fractal and first of all biological patterns like viruses and micro-organisms, Voronoi cells, DNA structure, rhizomes and various hybrids and permutations of these. Pattern became one of the most important elements and themes of contemporary architecture through the change of materiality and resurrection of ornament with the new perception of surface in architecture. One of the patterns that give new creative availability to the architectural design is biological pattern which is self-organized as an optimum form through interaction with environment. Biological patterns emerge mostly as self-replicating patterns through morphogenesis, certain geometrical patterns(in particular triangles, pentagons, hexagons and spirals). The architectural application methods of biological patterns are direct figural pattern of organism, circle pattern, polygon pattern, energy-material control pattern, differentiation pattern, parametric pattern, growth principle pattern, evolutionary ecologic pattern. These patterns can be utilized as practical architectural patterns through the use of computer programs as morphogenetic programs like L-system, MoSS program and genetic algorithm programs like Grasshoper, Generative Components with the help of computing technology like mapping and scripting.

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