• Journal of Ecology and Environment
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• 제44권3호
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• pp.162-177
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• 2020

Background: Ecologists have achieved much progress in the study of mechanisms that maintain species coexistence and diversity. In this paper, we reviewed a wide range of past research related to these topics, focusing on five theoretical bodies: (1) coexistence by niche differentiation, (2) coexistence without niche differentiation, (3) coexistence along environmental stress gradients, (4) coexistence under non-equilibrium versus equilibrium conditions, and (5) modern perspectives. Results: From the review, we identified that there are few models that can be generally and confidently applicable to different ecological systems. This problem arises mainly because most theories have not been substantiated by enough empirical research based on field data to test various coexistence hypotheses at different spatial scales. We also found that little is still known about the mechanisms of species coexistence under harsh environmental conditions. This is because most previous models treat disturbance as a key factor shaping community structure, but they do not explicitly deal with stressful systems with non-lethal conditions. We evaluated the mainstream ideas of niche differentiation and stochasticity for the coexistence of plant species across salt marsh creeks in southwestern Denmark. The results showed that diversity indices, such as Shannon-Wiener diversity, richness, and evenness, decreased with increasing surface elevation and increased with increasing niche overlap and niche breadth. The two niche parameters linearly decreased with increasing elevation. These findings imply a substantial influence of an equalizing mechanism that reduces differences in relative fitness among species in the highly stressful environments of the marsh. We propose that species evenness increases under very harsh conditions if the associated stress is not lethal. Finally, we present a conceptual model of patterns related to the level of environmental stress and niche characteristics along a microhabitat gradient (i.e., surface elevation). Conclusions: The ecology of stressful systems with non-lethal conditions will be increasingly important as ongoing global-scale climate change extends the period of chronic stresses that are not necessarily fatal to inhabiting plants. We recommend that more ecologists continue this line of research.

• KIEAE Journal
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• 제3권3호
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• pp.19-25
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• 2003

The Address No.0 of Eco-friendly Architecture offers unique experience for those who visit the place to envisage the future architecture where nature, human and building exist in harmony. It is open to the general public including the students of elementary and secondary schools. This house has been built to provide opportunities for the general public to experience eco-friendly architecture. It's floor area is 42 pyung($140m^2$) and the overall site has the area of 180 pyung($600m^2$). The following illustrates some of its prominent features : ${\bullet}$ Remodeling of a traditional Korean residence ${\bullet}$ Application of passive solar systems ${\bullet}$ Use of clerestory windows and daylighting systems(washroom and machine room) ${\bullet}$ Operation of solar water heaters with flat plate collectors ${\bullet}$ Construction of Biotop(small ecological world) ${\bullet}$ Water circulation for Biotop by photovoltaic(150W) and wind power(400W) generation ${\bullet}$ Outdoor hot water supplied by all-glass evacuated solar tubes. Through this Address No.0 of Eco-friendly Architeture conclusions are as followings. 1. The array of tubes in collector has the best nice in that the number of tube is nine and the tilt angle is the latitude $+20^{\circ}$. 2. The thermal performance of the all-glass solar vacuum collector was excellent than of the flate-plate solar collector. 3. The adaption of new small wind power systems to buildings were proved to produce a profit if it is considered the expense of environment improvement and the wind speed increasing according to rise of building hight.

• 한국산림과학회지
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• 제104권4호
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• pp.640-648
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• 2015

기후변화에 따른 사회적 요구는 국유림이 탄소흡수와 산림자원조성 측면에서 주도적인 역할로 자리매김하게 하였으며, 이에 국유림을 관리하는 국유림경영계획과 국유림경영계획 실행평가의 운영이 효과적인지 점검할 필요가 있다. 효과적인 계획수립과 경영은 올바른 평가방법을 바탕으로 확보될 수 있기에 본 연구는 국유림경영계획 실행평가 제도 개선방안을 제시하였다. 이를 위하여 타 분야의 평가 제도와 비교분석, 국유림업무 담당자 및 전문가와 면담 분석, 11개소 경영계획구의 국유림경영계획 최종평가서 분석을 실시하였다. 분석 결과 (1) 계획수립과 평가결과간 연계성을 강화하기 위해 각 평가별 목적과 시기 수정, (2) 사업수행과정을 반영하기 위해 사업별 가중치 할당, (3) 계획변경내역과 사유 기재를 통한 정성적 평가 진행, (4) 이러한 개선방안은 궁극적으로 국유림경영정보시스템과 연동되어야 함을 제시하였다. 미래 산림변화를 예측하고 지속가능한 산림경영을 이룩하는 것은 사업수행과정 전반에 대한 신뢰성 있는 평가에서 시작되며, 따라서 본 연구는 실행평가 고도화 방안을 제안했음에 그 의의가 있다.

• 대한산업공학회지
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• 제37권2호
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• pp.96-104
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• 2011

Modeling and simulation of human-involved complex systems pose challenges to representing human decision makings into logical systems because of the nondeterministic and dynamic nature of human behaviors. In modeling perspectives, human's activities in systems can increase uncertainty and complexity, because he or she can potentially access all other resources within the system and change the system states. To address all of these human involvements in the system, this research suggests applying the Finite State Automata (FSA)-based formal modeling of human-involved systems that incorporates the ecological concept of affordances to an evacuation simulation, so that human behavioral patterns under urgent and dynamic emergency situations can be considered in the real-time simulation. The proposed simulation methodologies were interpreted using the warehouse fire evacuation simulation to clarify the applicability of the proposed methodology. This research is expected to merge system engineering technologies and human factors, and come out to the new predictive modeling methodology for disaster simulations. This research can be applied to a variety of applications such as building layout designs and building access control systems for emergency situations.

• KIEAE Journal
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• 제10권4호
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• pp.75-80
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• 2010

Generally, ground-source heat pump (GSHP) systems have a higher performance than conventional air-source systems. However, the major fault of GSHP systems is their expensive boring costs. Therefore, it is important issue that to reduce initial cost and ensure stability of system through accurate prediction of the heat extraction and injection rates of the ground heat exchanger. Conventional analysis methods employed by line source theory are used to predict heat transfer rate between ground heat exchanger and soil. Shape of ground heat exchanger was simplified by equivalent diameter model, but these methods do not accurately reflect the heat transfer characteristics according to the heat exchanger geometry. In this study, a numerical model that combines a user subroutine module that calculates circulation water conditions in the ground heat exchanger and FEFLOW program which can simulate heat/moisture transfer in the soil, is developed. Heat transfer performance was evaluated for 3 different types ground heat exchanger(U-tube, Double U-tube, Coaxial).

• KIEAE Journal
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• 제2권2호
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• pp.15-22
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• 2002

Importation of mass production of building elements with standardization are vital way for environment-friendly architectural planning, which it makes the lifespan of a building longer than normal with easier maintenance and remodeling. The advantage might be magnified here in Korea since typical types of apartment house are dominated in our construction market. For the purpose, a series of pre-manufactured window systems is one of the optimal elements to be prototype building modules. In the design process of the system windows, lots of consideration should be involved and they include aesthetics, thermal performance, noise reduction, airtightness, and so forth. A real survey on the ready-made window systems has been performed and its optical issue related to luminous peculiarity is what is of major interest in this study. In addition, technical review on more advanced window products and their adaptable potential for the integration with fundamental architectural design elements were carried out.

• 한국환경과학회지
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• 제12권3호
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• pp.359-366
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• 2003

Ecological society and energy conservative systems has become a subject of world wide attention. To examine the technologies of such systems as resource recycling society, this study is proposed for using rainwater as energy source and water resources in urban area. Useful informations for planning of utilizing rainfall as energy source, water resources, emergency water and controlling flood are discussed with model systems in urban area. It is calculated that the rate of utilizing rainwater, amounts of utilizing rainwater, substitution rate of supply water, amounts of overflow rainwater according to rain storage tank volume. By applying the past weather data, The optimum volume of rain water storage was calculated as 200m$^3$ which mean no benefits according to the increase of storage tank volumes. For optimum planing and control method at the model system, several running method of rainwater storage tank was calculated. The optimum operating method was the using weather data as 3hours weather forecast.

• Journal of Ecology and Environment
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• 제29권5호
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• pp.411-414
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• 2006

The mating systems of two groups of natural populations of Gleditsia japonica var. koraiensis in Korea were determined using allozyme analysis. The result suggests that G. japonica var. koraiensis is predominantly outcrossing. The tm values of eight populations in Korea varied from 0.667 (Mdh-1) to 0.938 (ldh-1), giving an average 0.820. Population and individual outcrossing estimates were associated with flowering tree density or degree of spatial isolation. The reason for relatively low outcrossing rates of some populations could be attributed to reduction of effective population sizes of sib for the medicine, small population size, and isolation of flowering mature trees. The heterozygote excesses were observed in some natural populations, whereas other populations exhibited varying degrees of inbreeding and heterozygotes deficit. Thus, selection against homozygotes operated in the progeny populations throughout the life cycle.

• KIEAE Journal
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• 제15권2호
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• pp.53-59
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• 2015

Purpose: Reducing energy consumption and greenhouse gas emissions is a primary concern throughout the world, and the building sector is a particularly efficient area for making these reductions. In South Korea, the government has recently enacted policies for "Green Growth" that, among other things, enforce regulations in the building certification rating system (BCRS) and reorganize existing incentive systems. Method: In this study, we examined regulations and incentive systems used in the United Kingdom, Germany, and the United States that encourage the use of energy efficient technologies in construction and compared these policies to those used in South Korea. We also disseminated surveys to experts in the fields of architecture, planning and design, and engineering to better understand their knowledge and perception of the BCRS and its incentive systems. Additionally, we sought their recommendations for improving these incentive systems. Result: Based on our comparative case studies of regulations and incentives in other countries, alongside recommendations from experts in South Korea, we concluded that incentive systems in South Korea are limited and require improvement. We make recommendations for strengthening existing regulations and incentives and for implementing new incentive programs.

• Asian-Australasian Journal of Animal Sciences
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• 제10권6호
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• pp.621-628
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• 1997

This study aimed to quantify the impact of crossbreeding at farm level, in mixed farm systems in Gujarat. Households with crossbred cattle did not differ from households without crossbreds in terms of farm resources, crop gross margins and off-farm income. The use of crossbred animals did increase livestock gross margins by 64% and household income by 22%. The three agro-ecological zones included in this study differed considerably according to farm system and household income. However, in all three zones, households with crossbreds had higher livestock gross margins than households without crossbreds. There was no real difference in work load and labour division between households with and without crossbreds. There was also no difference in the use of bullocks for draught purposes between the two types of households. In particular buffaloes are being replaced by crossbred cattle. There was a large variation in farm income, largely because of land area. The milk offake per average cow and the number of buffaloes also related positively to farm income in both types of households. Crossbreeding has proved technically and financially viable in different Gujarat mixed farming systems. It can be concluded that crossbreeding is an important development option for landless farmers.