• 제목/요약/키워드: ecological systems

검색결과 703건 처리시간 0.026초

Seasonal and diel abundance and feeding patterns of Chaoborus flavicans in Sang-Chun reservoir

  • Jeong, Ga-Ram;Park, Sang-Kyu
    • Animal cells and systems
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    • 제14권4호
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    • pp.297-303
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    • 2010
  • To document the basic ecological aspects of Chaoborus species, which has never been reported in Korea, we attempted to identify the species, to monitor seasonal and vertical dynamics, and to elucidate trophic relations of the species in Sang-Chun reservoir. Using morphological characteristics, we identified the collected samples as C. flavicans. Also, we compared the distribution of C. flavicans, Daphnia rosea and chlorophyll a to observed seasonal dynamics. The increase of C. flavicans was observed 1-2 weeks after the increase of D. rosea. Survey of diel vertica migration patterns in the summer season showed that C. flavicans were in hypolimnion at daytime, but moved to the epilimnion at night. Finally, to determine trophic relationships in Sang-Chun reservoir, additional studies on the food web were undertaken by stable isotope analysis. Chaoborus flavicans I-II instars appear to be filter feeders based on carbon isotope values. Trophic levels of C. flavicans III-IV instars were shown to be higher than other zooplankto based on nitrogen isotope values.

Invasion of Ambrosia artemisiifolia L. (Compositae) in the Ukrainian Carpathians Mts. and the Transcarpathian Plain (Central Europe)

  • Song, Jong-Suk;Prots, Bohdan
    • Animal cells and systems
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    • 제2권2호
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    • pp.209-216
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    • 1998
  • The invasion of Ambrosia artemisiifolia in the Ukrainian Carpathians Mts. and the Transcarpathian Plain in Central Europe was reconstructed on the basis of floristic records. The first spontaneous occurrence was dated from the beginning of the 1940s. Within the next 55 year period, the distributional spread speed of the species was of 67.6 $km^2/y$ (by the average data). The occupied area by A. artemisiifolia in the range of the studied areas is about $3716.5km^2$ now. The features of behavior of the invader and the habitat preference were determined. The frequency of occurrence by sociologic-ecological classification was carried out. The generalized model of correlations among the gravitation, the active temperature sum and the disturbance gradients and the frequency of occurrence of the species was presented. The scheme of the invasion stages of A. artemisiifolia is reflected in the population status changes of the species during the areal dynamics.

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미세 필름을 이용한 집광 및 조명장치 연구 (A Study on Light Collector and Luminaire Design using Microstructured Film)

  • 정학근;한수빈;정봉만;이의준
    • KIEAE Journal
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    • 제2권1호
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    • pp.49-54
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    • 2002
  • Solar daylighting system provides free and comfort lighting, but its cost has been key issue due to difficult design and control of the heavy light collecting system. One of the solutions for the heavy design issues would be using a light framed film such fresnel and prism lens. Prism light guide luminaires have for some time been used to distribute light when it is desirable to have remote light sources. These systems are helpful when it is desirable to have fewer light sources, and/or to position light sources in places where lamp maintenance is easier, or electrical hazard is reduced. This proposed prototype system consists of light collector, light transformer and light pipe.

벽 및 천장이 흡음재로 마감된 다목적 체육관에서 음원종류에 따른 실내음향특성의 분석 (Analysis of the Room Acoustic Characteristics depending on the Sound Sources for a Multi-purpose Gymnasium finished with Absorbers on Walls and Ceiling)

  • 박현구;전지현;송혁;김선우
    • KIEAE Journal
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    • 제2권1호
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    • pp.41-48
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    • 2002
  • This study aims to investigate and evaluate the room acoustic designs of a multi purpose gymnasiums which do not use adjustable treatments in order to change the acoustical characteristics. Considering the main uses of gymnasium and auditorium, experiments were carried out using both nondirectional speakers on the stage and loudspeaker installed on the ceiling. The result from the study are as follows; Measured RT under unoccupied condition was a little longer than the expected value, therefore, in the case of occupied condition RT would be close to the optimum value. However, parameters that evaluate intelligibility and speech transmission property appeared to be low and have large differences depending on the measuring points, therefore, more effective sound reflecting surfaces and sound reinforcement systems should be considered.

건축물 일체형으로서 광선반형 자연채광시스템의 건축물 적용기법에 관한 연구 (Application of Lightself to Buildings as a Integrated Daylighting System)

  • 김정태;정유근
    • KIEAE Journal
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    • 제2권3호
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    • pp.17-24
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    • 2002
  • For sustainable building design, using day lighting is considered a variable technique to save energy and create comfort indoor environments. Specially, the lightself as a integrated daylighting system is one of the most important techniques due to it's durability, availability and lighting performance. This paper aims to analyze the development and architectural application of a lightself system to buildings as a integrated day lighting system. For the study, advanced lightself systems developed in abroad such as "Integrated Enveloped and Lighting System", "Anidolic Daylighting System" and etc. are analyzed. Also, the architectural examples are investigated. As results, the new technologies such as optically treated reflective and sun-tracking are adopted to improve daylight performance. And, lots of environmentally friendly buildings are installed on integrated lightself system.

초고층아파트 단위주공간의 지속가능성 평가요소 분석 (An Analysis of the Sustainability of High-rise Apartment Unit Design Elements)

  • 이은정
    • KIEAE Journal
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    • 제6권3호
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    • pp.57-66
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    • 2006
  • The issue of sustainability has been prevailed not only in building industry but also all other industries. It has been raised that the concept of sustainability should take into account for the design of multi-use high-rise apartments. In this study, the present situation and trends of the multi-use high-rise apartment construction have been reviewed. The definition of sustainable design of high-rise apartment has been clarified so as to perceive the related design elements through the literature survey. Finally this study has derived the sustainable design elements of high-rise apartment unit plans through the comparative analysis of sustainable design guidelines, environmentally friendly building accreditation systems and literature survey in and abroad.

청소년 수련관의 열원설비 대안별 생애주기 비용에 관한 연구 (Analysis of Life Cycle Cost for Heat Source Equipments in Buildings for Adolescent Trainees)

  • 안창환;방승기;백용규
    • KIEAE Journal
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    • 제5권3호
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    • pp.25-31
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    • 2005
  • Computer simulations were performed for Heating Ventilating and Air-Conditioning (HVAC) systems to figure out more efficient maintenance methods for the building used for adolescent trainees. This study aims at suggesting design alternatives for optimum operation and performing life cycle cost (LCC) for each alternative. First, the capacity of the heat source equipment was determined using annual maximum heating and cooling loads. Annual loads were calculated and applied to the alternative for the purpose of calculating annual energy cost. Second, several types of data were collected to predict energy cost. Finally, the pay back period for each alternative was calculated using total cost estimation during standard duration period. This study indicates that the absorption chiller that does not occupy most part of a mechanical room, and does not need much operation cost was most economical.

Paternal Involvement within Contexts: Ecological Examination of Korean Fathers in Korea and in the U.S.

  • Kwon, Young-In
    • International Journal of Human Ecology
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    • 제11권1호
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    • pp.35-47
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    • 2010
  • Based on concepts of human ecology, this study explored how diverse systems- cultural setting, work context and maternal perception- shape paternal involvement in child care. For this purpose, I compared Korean fathers (n=93) and Korean sojourner fathers in the United States (n=129). Hypothesized structural equation model explaining direct and indirect relationships among variables was developed. The results showed that cultural context had no direct relationship with paternal involvement. Cultural context showed indirect influence on paternal involvement through fathers' work context. Maternal perception, which had significant relationship with paternal involvement, was not explained by cultural context. However, it was significantly influenced by work context.

Plant.Green.Living Environment -Urban Construction and Establishment of Green Space in Kunming-

  • Cheng, Hai-Lan
    • Journal of the Korean Institute of Landscape Architecture International Edition
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    • 제1호
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    • pp.131-134
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    • 2001
  • Green and plants, as it symbol the life and depute the nature, always give human an easy comfort psychologically. The paper is a brief analysis to the idea frame of urban construction and reform of Kunming through our practice about ten years. On which three main principles should be carefully considered. One is that the green-space composed of plant system is of the important infrastructure of a modern city as it can not be instead of by any other factor in the ecological system of the city. The other is that in the course of planning and construction the local feature as well as its culture tradition in history should be pied more attention. In order to create a distinguish character of itself the third may be more important that to coordinate each key elements of it such as green, water, light, building, road, etc., to get a harmonious sphere of human and nature. A modern city should be a green city in which nature and man co-exist harmoniously.

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Landscape pattern analysis from IKONOS image data by wavelet and semivariogram method

  • Danfeng, Sun;Hong, Li
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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    • pp.1209-1211
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    • 2003
  • The wavelet and semivariogram analysis method are used to identify the city landscape and farmland landscape pattern on the 1m resolution IKONOS images. The results prove that wavelet method is a potential way for landscape pattern analysis. Compared to semivariogram analysis, Wavelet analysis can not only detect the overall spatial pattern, but also find multi-scale and direction structures. In this experiment, the wavelet analysis results indicate: (1) the city landscape image is mainly composed of three level structures whose spatial pattern characters appear at 2m, 16m, 128m and 256m accordingly; (2) the farmland landscape is mainly two scale spatial patterns appearing at the 2m, 128m and 256m. IKONOS Remote sensing, with the high spatial and spectral information, is a powerful tool that can use in many ecological systems research and sustainable management.

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