• 제목/요약/키워드: Spatial variation

검색결과 1,356건 처리시간 0.029초

A descriptive spatial analysis of bovine tuberculosis disease risk in 2015 in Gangwon-do, Republic of Korea

  • Kim, Eu-Tteum;Pak, Son-Il
    • Journal of Preventive Veterinary Medicine
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    • 제41권2호
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    • pp.79-83
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    • 2017
  • In this study, we used a choropleth map to explore the spatial variation of the risk of cattle herds being bovine tuberculosis (BTB) positive in Gangwon-do in 2015. The map shows that the risk of being BTB-positive was lower in provinces located in the middle of Gangwon-do (Wonju, Youngwol, Peongchang, and Kangneung) than in other provinces. In addition, one province located in the north (Goseong) had a low risk of BTB. The estimate for the intercept of the spatial lag model was 0.66, and the spatial autocorrelation coefficient (lambda) was 0.20 (Table 1). The Moran's I was 0.33 with p-value of 0.02. In 2015, provinces located in the North West (Hwacheon) and East (Donghae) of Gangwon-do had a higher BTB risk. We identified some specific provinces at low BTB-positive risk, information that may prove useful for control of BTB in the study area.

신뢰성 기반 해석을 위한 국내 CFRD 사력존 재료의 전단파 속도 변동계수 결정 (Determination of the Coefficient of Variation of Shear Wave Velocity in Rock Filled Zone of CFRD (Concrete Faced Rock Filled Dam) for Reliability Based Analysis)

  • 박형춘;임희대
    • 한국지반공학회논문집
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    • 제33권4호
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    • pp.17-24
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    • 2017
  • 지진과 같은 외부 하중하에서 CFRD 거동은 사력존의 전단파 속도(또는 전단 탄성계수)분포에 큰 영향을 받는다. 일반적으로 사력존의 전단파 속도 분포는 주상도의 형태로 표면파 시험과 같은 비파괴 시험에 의해 결정될 수 있다. 이때 한정된 수의 실험에서 결정된 전단파 속도 주상도에는 불확실성이 존재하며, 이러한 불확실성은 사력존에 존재하는 물성치 공간 변동성에 의해 발생하게 된다. 내진 해석과 같은 다양한 해석에서 물성치 변동성에 의해 발생할 수 있는 해석 결과의 불확실성은 신뢰성 기반 해석을 통해 고려될 수 있다. 신뢰성 기반해석에서는 재료 물성치의 변동계수 결정을 통해 이러한 불확실성을 해석에 반영한다. 본 연구에서는 국내 CFRD 사력존을 위한 전단파 속도변동계수를 결정하였다. 이를 위해 국내 CFRD 사력존에서 결정된 전단파 속도 주상도들과 하모닉 웨이브릿 해석에 기반한 기법을 사용하여 국내 CFRD 사력존에 존재 가능한 600개의 전단파 속도 주상도를 생성하고 이를 이용하여 사력존 전단파 속도 분포의 깊이별 변동계수를 결정하였다.

휴게실 공간의 조명환경에 대한 시각적 감지 및 심리적 반응에 따른 공간 인지도 변화 (Variation of Spatial Cognition According to Visual Perception and Psychological Responses for Lighting Environments in Rest Space)

  • 김재상;이지현;김수영
    • 설비공학논문집
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    • 제24권5호
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    • pp.443-453
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    • 2012
  • This study examines visual perception and spatial satisfaction according to lighting conditions. Field measurements and surveys were performed in three rest space of university buildings where various lighting conditions were employed. Results indicate that overall impression of space improved when low color temperature, such as 3,000 K governed overall lighting environment and accent lighting was used for wall surfaces. Lighting conditions that kept uniform illuminance levels using area light sources containing fluorescent lamps with 6,500 K failed to keep favorable spatial satisfaction for space. High color temperature was not recommended for lighting in rest space. Asymmetrical illuminance levels formed by low color temperature such as 3000 K is recommended to keep positive mood and improve spatial satisfaction in rest space. Overall impression of the space was influenced by visual comfort, color temperature, spatial satisfaction and brightness. Spatial satisfaction for space was effectively impacted by psychological comfort, color temperature and overall impression for lighting conditions. Psychological comfort in space was influenced by color temperature, spatial satisfaction and visual annoyance from reflected light.

천문학적 공간개념 수준에 관한 검사도구 개발 (Development of the Test Tool of Astronomical Spatial Concept Level)

  • 서창현;이항로;김희수
    • 한국지구과학회지
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    • 제24권6호
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    • pp.508-523
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    • 2003
  • 본 연구에서는 고등학생들의 천문학적 공간개념 수준을 측정하기 위한 검사도구를 개발하였다. 이 검사도구는 천문학적 공간개념을 이루고 있는 기본적인 하위 요소들 (공간위치, 공간추리, 공간변화)을 평가할 수 있는 평가문항으로 구성되어있다. 개발된 검사도구는 274명의 고등학생들에게 투입되어 검증되었다. 문항 분석결과, 본 검사도구의 내용타당도는 98%였으며, 신뢰도(K-R 20)는 0.84, 정답율 52%, 변별도 지수 0.27로 나타났다. 따라서 이러한 결과는 본 검사도구가 고등학생들의 천문학적 공간개념 수준을 측정할 때 활용 가능함을 의미한다.

벼 재배 포장 생육변이의 공간통계학적 해석 (Geo-statistical Analysis of Growth Variability in Rice Paddy Field)

  • 이충근;성제훈;정인규;김상철;박우풍;이용범;박원규
    • Journal of Biosystems Engineering
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    • 제29권2호
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    • pp.109-120
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    • 2004
  • To obtain basic information for precision agriculture, spatial variability of rice growth condition was evaluated in 100m ${\times}$100m paddy field. The rice growth condition of four hundred locations in the field were investigated to analyze the spatial variability of their properties ; SPAD, plant length and tiller number. Geostatistical analysis was carried out to examine within-field spatial variability using semivariograms and kriged maps as well as descriptive statistics. Descriptive statistics showed that the coefficient of variation for SPAD, plant length, and tiller number exceeded 5.70 %, suggesting a relatively high variability. Geostatistical analysis indicated a high spatial dependence for all the properties except for the second tiller number. The range of spatial dependence was about 20 m for SPAD, plant length, and tiller number. Based on the results of spatial dependence, kriged maps were prepared for the properties to analyse their spatial distribution in the field. The results reflected the history of field management. In conclusion, the need for site-specific field management and possibility of precision agriculture were demonstrated even in an almost flat paddy field.

위성영상을 통한 서울시 지표온도 분석 (The Land Surface Temperature Analysis of Seoul city using Satellite Image)

  • 정종철
    • 환경영향평가
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    • 제22권1호
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    • pp.19-26
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    • 2013
  • The propose of this study is to analyze the optimum spatial resolution of the urban spatial thermal environment structure and to evaluate of the possibility detection using aerial photographs and thermal satellite images. The proper techniques of the optimum spatial resolution for the urban spatial thermal environment structure were analyzed. Thermal infrared satellite image of Seoul city were used for the change rate of surface temperature variation and suggested to the spatial extent and effects of urban surface characteristics and spatial data was interpreted as regions. To extract the surface temperature, Landsat thermal infrared satellite image compared with an automatic weather station data and in the field of the measured temperature and surface temperature by thermal environment affects, the spatial domain has been verified. The surface temperature of the satellite images to extract after adjusting surface temperature isotherms were constructed. The changes in surface temperature from 2008 to 2012 the average surface temperature observation images of changing areas were divided into space. The results of this study are as follows: Through analysis of satellite imagery, Seoul city surface temperature change due to extraction comfort indices were classified into four grades. The comfort index indicative of the temperature of Gangnam-gu, $23.7{\sim}27.2(^{\circ}C)$ range and Songpagu, a $22.7{\sim}30.6(^{\circ}C)$ respectively, the surface temperature of Yeouido $25.8{\sim}32.6(^{\circ}C)$ were in the range.

개폐식 대공간 구조물을 위한 스마트 TMD 설계기법 개발 (Design Method Development of Smart TMD for Retractable-Roof Spatial Structure)

  • 김현수;강주원
    • 한국공간구조학회논문집
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    • 제17권3호
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    • pp.107-115
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    • 2017
  • In this paper, a structural design method of a smart tuned mass damper (TMD) for a retractable-roof spatial structure under earthquake excitation was proposed. For this purpose, a retractable-roof spatial structure was simplified to a single degree of freedom (SDOF) model. Dynamic characteristics of a retractable-roof spatial structure is changed based on opened or closed roof condition. This condition was considered in the numerical simulation. A magnetorheological (MR) damper was used to compose a smart TMD and a displacement based ground-hook control algorithm was used to control the smart TMD. The control effectiveness of a smart TMD under harmonic and earthquake excitation were evaluated in comparison with a conventional passive TMD. The vibration control robustness of a smart TMD and a passive TMD were compared along with the variation of natural period of a simplified structure. Dynamic responses of a smart TMD and passive TMD under resonant harmonic excitation and earthquake load were compared by varying mass ratio of TMD to total mass of the simplified structure. The design procedure proposed in this study is expected to be used for preliminary design of a smart TMD for a retractable-roof spatial structure.

리좀과 하이퍼텍스트 관점에서 본 도서관 공간구조의 이해 (A Study on the Transition of Spatial Structure in Libraries with Special Reference to Rhizome and Hypertext)

  • 최윤경;김민중
    • 한국실내디자인학회논문집
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    • 제15권6호
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    • pp.111-119
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    • 2006
  • The spatial property of contemporary library is now rapidly changing through the spatial expansion of knowledge and information, the reduction of information storing facility, the variation of approaching methods by digital shift and the transition of social recognition as a cultural facility. Also the spatial characteristics with referring characters have developed such as, decentralization, de-construction, de-boundary, individual space, erasing of boundary, flow of space which extends infinitely. The main process of library origination, the systematic classification, and the storage system concluding with the demand and value of the information by changing social demands and the role of the widest ranged facility. And 5 themes, such as, hierarchy, center, storage, boundary, and symbol, as a changed spatial concept and analyzed in the case of library plans and libraries which are actually built. The significant purpose of this research is to propose that rhizomatous intellectuality and hypertext could be a theoretical background of the contemporary architecture and could be a viewpoint of the transition of spatial structure in libraries. A future library should have spatial property embracing various social changes and needs and for this respect, it is necessary to approach and analyze through the architectural explication from diverging points of view.

강우공간상관구조의 변동 특성 (On the Variations of Spatial Correlation Structure of Rainfall)

  • 김경준;유철상
    • 한국수자원학회논문집
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    • 제40권12호
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    • pp.943-956
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    • 2007
  • 강우장의 특성을 정량화하는 여러 통계적 특성치 중에 자주 사용되는 공간상관함수(또는 공간상관도)는 강우의 평가나 설계 그리고 강우장을 모형화하는데 중요하게 사용된다. 그러나 강우의 공간상관 구조는 여러 요인에 의해 많은 변동성을 가지고 있다. 이와 같은 강우의 공간상관구조에 대한 변동특성은 유역을 대표하는 공간상관구조를 결정하는데 문제점으로 작용한다. 따라서 본 연구에서는 이변량 혼합분포를 이용하여 강우를 모형화한 후 정규분포와 대수정규분포를 고려하여 월별, 자료의 시간간격별로 공간상관도를 유도하고 그 변동특성을 파악하였다. 대상유역인 금강유역의 28개 강우관측소의 자료를 이용한 결과 다음과 같은 결론을 얻을 수 있었다. (1) 무강우자료에 대한 영향을 고려한 결과, 세 가지의 경우(Case A, B, C) 중에서 Case A(+,+)의 경우가 #0#에 대한 공간상관함수의 왜곡이 최소가 되기 때문에 가장 적절한 경우이다. (2) 일반적으로 사용되는 정규분포보다는 이론적 그리고 실증적으로 더 적절한 대수정규분포를 사용해야 함이 바람직하다. (3) 월별 공간상관함수 중 지수함수적인 감소경향이 가장 뚜렷한 7월의 경우가 유역을 대표하는 공간상관함수로 적절하다. (4) 자료의 시간해상도별 공간상관도는 다르게 유도되기 때문에 각각에 대한 경우를 고려해야 한다.

다공질 공기베어링 테이블의 운동오차 해석 (Motion Error Analysis of an Porous Air Bearing Table)

  • 박천홍;이후상
    • 연구논문집
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    • 통권34호
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    • pp.101-112
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    • 2004
  • In order to analyze the motion errors of the aerostatic stage, it is necessary to consider the influence of the moment variation occurredinside the pads. In this paper, a motion error anaysis method utilizing the transfer functions on the reaction force and moment is proposed, and general characteristics of the transfer functions are discussed. Calculated motion errors by the proposed method show good agreement with the ones calculated by Multi Pad Method, which is considered the entire table as an analysis object. Also, by the introduction of the transfer function of motion errors, which represent the relationship between the spatial frequency components of the rail form error and motion errors, motional characteristics of the porous aerostatic stage can be generalized. In detail, the influence of the spatial frequencies is analyzed quantatively, and the patterns of the insensitive frequencies which almost do not affect the linear motion error or angular motion error according to the rail length ratio and the number of the pad are verified. The relationship between the moment variation occurred inside the pads and the motion errors is also verified together.

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