• Title/Summary/Keyword: ecological systems

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Development Strategies of Construction Management Firms in Korea (국내 건설관리 업체의 발전전략)

  • Han, Kap Ky;Kim, Sun Kuk
    • KIEAE Journal
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    • v.7 no.4
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    • pp.97-104
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    • 2007
  • Competition among building contractors in the Korean construction environment has been increasing lately, and with the recent conclusion of the FTA between Korea and the United States, further advancement in the systems of construction, bidding and contract awarding is expected to be facilitated in the long term. Considerable changes are also expected particularly in the construction management (CM) market. Given these drastic changes, it has become more noticeable that the role of CM is enlarged in terms of time, cost, quality, risks and others to guarantee the Korean competitiveness against the global construction market. This study analyzed the current status of domestic CM companies via SWOT analysis and, based on such analysis, established development strategies for CM contractors. The strategies proposed in this study will be utilized by CM companies as basic materials in their future strategies in a short, mid and long term perspective respectively for competitive advantages in the market.

A Survey on Foreign and Domestic Interior Noise Criteria for Walls and Floors (공동주택 내부소음 기준과 바닥 및 벽체 차음성능 기준 고찰)

  • Kim, Sun-Woo;Song, Min-Jeong
    • KIEAE Journal
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    • v.4 no.3
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    • pp.37-44
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    • 2004
  • In this study, foreign and domestic noise criteria on walls, floors, and water supply facilities were reviewed and the results are as follows : regulation can be divided two things, one is on thickness the other is sound insulation performance. Green Building regulation based on the law and this have sound classification systems. Since these regulations are not established in Korea. The noise regulation on water supply-drain facilities and domestic guideline on interior noise level is needed. Foreign regulations are stricter than those of ours. And those has sound classification system for the better acoustic condition of inhabitants'.

Permanence of an impulsive food web system with Holling-type II functional responses

  • Baek, Hun-Ki;Park, Jun-Pyo;Do, Young-Hae
    • Journal of the Korean Data and Information Science Society
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    • v.20 no.1
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    • pp.211-217
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    • 2009
  • In this paper, we are studying the property for permanence of a three species food chain system with impulsive perturbations and Holling type II functional response, species which is important concept or property in ecological systems. Specially, we give the conditions for the permanence of this system. To do it, we consider the comparison method which is typical skill happened in impulsive differential inequalities. In addition, we reaffirm our results by using a numerical example.

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Allelopathic Potential of Select Gymnospermous Trees

  • da Silva, Jaime A. Teixeira;Karimi, Javad;Mohsenzadeh, Sasan;Dobranszki, Judit
    • Journal of Forest and Environmental Science
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    • v.31 no.2
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    • pp.109-118
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    • 2015
  • Allelopathy is an ecological phenomenon that refers to the beneficial or harmful effects of one plant on another plant, both crop and weed species, by the release of organic chemicals (allelochemicals) from plant parts by leaching, root exudation, volatilization, residue decomposition in soil and other processes in both natural and agricultural systems. Allelopathy can affect many aspects of plant ecology including occurrence, growth, plant succession, the structure of plant communities, survival, dominance, diversity, and plant productivity. In this review, we describe the concept of allelopathy, some mechanisms of operation within plants and then focus on a select number of gymnospermous tree genera: Ephedra, Pinus, Taxus, Cedrus, Juniperus, Picea, Cunninghamia and Araucaria. Pinus, Taxus (yew) and Cedrus (cedar) trees have a strong negative allelopathic effect on the germination, growth, or development of other plant species in the forest community.

A Study on Realization Method of Low Carbon School Building (저 탄소 학교건축물 구현 방안에 관한 연구)

  • Tae, Sung-Ho;Cho, Young-Sang;Shin, Sung-Woo;Lee, Seung-Min;Meang, Joon-Ho
    • The Journal of Sustainable Design and Educational Environment Research
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    • v.9 no.2
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    • pp.30-37
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    • 2010
  • This study purposed realization and a phase reduction of school building $CO_2$ emissions. Accordingly selected standard school buildings and evaluated life cycle environmental load($CO_2$). This study proposed Green building technology which separated design sector, energy sector, afforestation sector for carbon-neutral city school buildings realization of M-city. As a result, elementary, middle and high schools of M-city built in the year 2013 were required that design sector was Energy Performance Index(EPI) 75 point and energy sector was solar installations more than 25% of the power usage, Solar systems installed more than 10% of total gas consumption and the area of afforesting more than 35% of the ecological area to achieve 30% $CO_2$ reduction compared to the Respectively standard school buildings.

Water Quality Improvement by Artificial Floating Island (인공섬을 이용한 소형 저수지의 수질 개선)

  • Park, Hyun-Jin;Kwon, Oh-Byeong;Ahn, Tae-Seok
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.4 no.1
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    • pp.90-97
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    • 2001
  • For improvement of water quality, $20m^2$ of artificial floating plant islands planted with Iris pseudoacorus, were installed in small pond on March, 1999. Small pond has surface area $1,000m^2$ and mean depth 1.5 m. The density of plants was 16 per $m^2$ by using jute pot. Environmental parameters such as COD, SS, T-N, T-P and planktons were biweekly measured from 29 March to 28 September. Because of the small portion of floating island, the effect for water quality improvement was not sufficient. But considering the data of plant growth and nitrogen and phosphorus uptake capacity of plant, about 40% of coverage by artificial floating island was needed for elimination of whole nutrients from inflow.

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The use of conservation drones in ecology and wildlife research

  • Ivosevic, Bojana;Han, Yong-Gu;Cho, Youngho;Kwon, Ohseok
    • Journal of Ecology and Environment
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    • v.38 no.1
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    • pp.113-118
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    • 2015
  • Conservation drones are remote-controlled devices capable of collecting information from difficult-to-access places while minimizing disturbance. Although drones are increasingly used in many research disciplines, their application to wildlife research remains to be explored in depth. This paper reports on the use of Phantom 2 Vision+ for monitoring areas in two national parks in South Korea. The first research area was conducted in Chiaksan National Park, and the second in Taeanhaean National Park. The aim of this research is to introduce ecologists and researchers alike to conservation drones and to show how these new tools have are fundamentally helping in the development of natural sciences. We also obtained photographs and videos of monitoring areas within our test site.

Streptococcus mutans Strains Isolated in Korea Can Hardly Metabolize Exogenous Nitric Oxide

  • Lee, Hwa Jeong;Bang, Iel Soo
    • International Journal of Oral Biology
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    • v.40 no.4
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    • pp.217-221
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    • 2015
  • Cariogenic Streptococcus mutans encounters a variety of host defense factors produced in oral cavity. Nitric oxide (NO) and NO-mediated reactive nitrogen species are potential antimicrobials of innate immunity that can threaten the fitness of S. mutans in their ecological niches. Streptococcal strategies to detoxify cytotoxic NO, which allow S. mutans to persist in caries or other environments of the oral cavity, remain unknown. In this study, we directly measured NO consumption rates of S. mutans isolated in Korea. Surprisingly, all S. mutans strains were unable to consume exogenous NO efficiently, while an intracellular parasite Salmonella enterica serovar Typhimurium expressing the NO-metabolizing enzyme flavohemoglobin consumed most of the NO. This result suggested that S. mutans has alternative detoxification systems for tolerating NO-induced nitrosative stresses.

Evaluation of Environmental Performance of Energy Systems employing Market Allocation Model in Building Sector in Korea (시장분배모형을 이용한 건물부문 에너지 시스템 환경성능평가)

  • Park, Tong-So
    • KIEAE Journal
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    • v.2 no.4
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    • pp.65-72
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    • 2002
  • In this study, the evaluation of environmental performance of the building energy system of domestic commercial sector was carried out. Based on the theory of linear programming model, we established an evaluation model satisfying object functions and constraint conditions. Employing the model, the evaluation of building energy system was performed under the consideration of cost and environmental constraint conditions. As an evaluation tool, MARKAL (MARKet Allocation) known as a market distribution model was employed. We analyzed scenarios of Case I (Base Scenarios) through Case IX established by the combination of the components of building energy system such as glazing, building skin, core, and heat source system. According to the results of the evaluation, highest contribution on the useful energy demand was obtained from the building energy system combined with solar heat source system, when the total amounts of $CO_2$ exhaust as an environmental constraint condition is assumed to be the level of 1995.

The Summer Cooling and Lighting Energy Performance Evaluation of Small Office Buildings with Venetian Blinds (블라인드를 고려한 여름철 소규모 사무소 건물의 냉방 및 조명에너지 평가)

  • Chung, Yu-Gun
    • KIEAE Journal
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    • v.13 no.1
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    • pp.39-45
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    • 2013
  • The daylighting control system has to be applied to prevent the excessive incident daylight and reduce energy use. As the one of the most useful daylighting control systems, the blind system is simple and easy to install on the window for small office buildings. This study aims to evaluate the summer energy performance of small office buildings by venetian blinds and energy saving strategy of ministry of knowledge economy in korea. For the study, the simulations have been executed on blind installation conditions and lighting control methods. As results, the energy loads cut down 22 to 25(%) by using blind energy. Also, the efficient shows high on EMS system and low on $45^{\circ}$ slat angles. Also, using energy saving strategy can reduce about 13(%) energy load.