• The Korean Journal of Ecology
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• 제19권2호
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• pp.165-178
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• 1996

We investigated the role of competition in adaptation to varying water availability levels for two ecotypically-differentiated populations of Impatiens pallida found naturally in low- vs. high-water environments. In a greenhouse experiment, seedlings were grown in pure cultures at two densities (n=1 and 2 plants per pot) and in mixed cultures (n=2) under low-, medium- and high-water treatments. The two populations were shown to be genetically distinct across the range of environmental conditions in the greenhouse experiment, confirming previous findings. The two populations had similar morphological responses to density and water availability in pure cultures and mixtures, but the population from the high-water environment showed a greater growth response to high water availability than did the population from the low-water environment and the difference in growth between the two populations decreased from the high-water to low-water treatment. Relative competitive ability of two populations were compared under three different water treatments and two densities. Differential response to watering treatment and density were not reflected in a difference in relative competitive ability. Relative yield totals were significantly greater than 1 overall. The niche differentiation suggested by RYTs>1 may be responsible for the lack of differential competitive effects observed for populations in the three vatering treatments.

• Journal of Ecology and Environment
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• 제36권1호
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• pp.39-47
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• 2013

The expression of transgenic traits in genetically modified crops is sometimes associated with decreases in crop performance or fitness. These decreases in performance or fitness of transgenic plants in unfavourable conditions may provide valuable information about the ecological consequences of transgene escape. In a glasshouse trial, we tested the cost associated with resistance to herbicides by comparing the growth, yield, and competitive ability of transgenic rice with its parental non-transgenic line. This new line was developed for constitutive overexpression of protoporphyrinogen oxidase (PPO) to increase resistance to herbicides. We evaluated nine agronomic traits of transgenic and non-transgenic rice grown in a replacement series design over four densities. Competitive ability was also assessed between transgenic and non-transgenic plants by analyzing their relative yields based on biomass and seed weight data. Our results indicated that non-transgenic plants showed greater performance than did the transgenic plants when those genotypes were grown in mixtures. The non-transgenic rice plants exhibited superior competitive ability at certain combinations of planting densities and genotype proportions. These results suggest that PPO-herbicide resistance incurs some costs in plant performance and competitive ability.

• 한국잡초학회지
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• 제7권1호
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• pp.45-51
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• 1987

적미(赤米)에 대한 벼의 경합시기(競合時期)와 경합력(競合力)을 구명(究明)하기 위하여 폿트를 이용(利用), 적미(赤米)와 수도(水稻)를 함께 이앙(移秧)하여 이앙후 10일(日)부터 60일(日)까지 10일(日) 간격으로 적미(赤米)를 제거(除去)하여 한계 경합기간(競合期間)을 구명(究明)하였으며, 경합력(競合力)을 구명(究明)하기 위하여 대체적(代替的)인 설계방법(設計方法)에 의해 시험(試驗)을 수행(遂行)하였다. 검토(檢討)된 결과(結果)를 요약(要約)하연 다음과 같다. 1. 적미(赤米)에 의한 경합기간(競合期間)이 길어질수록 수도(水稻)의 초장(草長), 경수(莖數)의 감소(減少)는 크게 나타났으며 최고분벽기(最高分蘗期)는 빨라지는 경향(傾向)이었다. 2. 수도수량(水稻收量)은 이앙후(移秧後) 20일(日)부터 유의성(有意性) 있게 감소(減少)하기 시작(始作)하였으며 이는 주당수수(株當穗數) 감소(減少)가 가장 큰 요인(要因)이었으며 수당입수(穗當粒數), 간장(稈長)의 감소(減少)가 함께 영향을 끼친 것으로 생각된다. 3. 대체적(代替的) 설계(設計)에 의한 수도(水稻)와 적미(赤米)와 상호경합(相互競合)은 길항적(拮抗的)이었으며 따라서 상대수량계(相對收量計)도 상호길항적(相互拮抗的)임을 추정(推定)할 수 있었다. 4. 대체적(代替的) 설계(設計)에 의한 경합력 조사결과 수도(水稻), 적미(赤米)의 수당입수(穗當粒數), 간장(稈長), 수장(穗長) 변화(變化)는 큰 차이가 없었다. 5. 적미(赤米)의 수수(穗數)가 $m^2$당(當) 300 본(本) 발생(發生)되면 수량(收量)은 약(約) 50% 감수(減收)되었다.

• 한국항해항만학회지
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• 제40권5호
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• pp.317-328
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• 2016

The steady growth of seaborne trade has resulted in the further development of container ships, ports, and container terminals, and the operating efficiency of a container terminal is a decisive element for its competitive ability in international markets. The aim of this research is to evaluate the relative efficiency of Russian and South Korean container terminals. For this purpose, the output-oriented DEA was applied to 31 container terminals of Russian and South Korean seaports for the years from 2012 to 2014. The results indicate that Korean container terminals exhibited higher efficiency scores than their Russian counterparts.

• Toxicological Research
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• 제24권4호
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• pp.235-243
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• 2008

While in some instances, loss of diversity results from acute toxicity (e.g. major pollution incidents), in most cases it results from long-term sub-lethal effects that alter the relative competitive ability and fitness of certain organisms. In such cases the sub-lethal effects will cause a physiological response in the organism that ultimately leads to community level changes. Very sensitive tools are now available to study sub-lethal responses at the molecular level. However, relating such laboratory measurements to ecological effects represents a substantial challenge that can only be met by investigation at all scales (molecular, individual organism and community level) with an appropriate group of organisms. Among the various in vertebrates which can be used as model organisms in such a way, the soil nematode, Caenorhabditis elegans appear to be a promising biological model to diagnose environmental quality. This paper reviews the current status of multilevel biomarkers in environmental toxicology, and C. elegans as promising organisms for this approach.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 춘계학술대회 논문집
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• pp.1441-1446
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• 2008

Seoul Metro Line 9 (SML9) is the first subway line that private capital invests in Korea. SML9 will cross Seoul, linking the Gimpo Airport to the Gangnam district (25.5km) opening in the first half of 2009. SML9 has a new model in Korea constructed by metropolitan government and private company and operated by specialized public transportation service provider. SML9 is confronted with tough environment of stagnated public transportation and strong competitor, Olympic city expressway. And SML9 is under pressure for showing high efficiency as non-governmental organization from both customers and government. Consequently SML9 must lead the maximum efficiency by using its material and human resource. It is necessary that SML9 raise a competitive power and display its ability in active collaboration with relative organization and company. Hereupon, I propose renovation plans from viewpoint of operation field of SML9, (1) efficient train scheduling regime focusing on the combination of express and local train (2) close connection of other mean of transportation and (3) effective connection convention with Airport Railroad (AREX) as the line connected directly.

• 한국작물학회지
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• 제31권4호
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• pp.426-433
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• 1986

목초의 단ㆍ혼파군낙에서 초종조합별 수량성과 각 초종의 지상부와 지하부의 경합력을 평가하고 그들의 상호관계를 비교하여 이상적인 혼파초지모형의 기초자료 및 방법을 제시하기 위하여 오차드그라스, 토올페스큐, 라디노클로버 및 알팔파의 각 단파와 2초종의 혼파조합으로 이루어진 10개의 대형폿트 군락에서 시험을 실시하였다. 경합관계는 지상부와 지하부를 분리하여 건물중으로 평가하였데 그 방법으로서 는 expected yield, aggressivity, relative yield total (RYT) 및 compensation index (CI)와 general combining ability (GCA) 및 specific combining ability(SCA)를 계산하여 비교ㆍ해석하였다. 목초수량에서는 화본과초종인 오차드그라스, 토올페스큐의 각 단파 및 그들의 혼파가 유리하였고 두과초종인 라디노클로버와 알팔파의 단파 및 혼파의 경우에는 불리하였다. 목초의 수량으로 살피본 지상부경합에서 토올페스큐-라디노클로버 혼파조합만이 RYT가 1.05로 유리하였고 단파의 경우보다 토올페스큐가 우점종이었다. 또한 화본과혼파와 두과혼파는 사본과-두과혼파조합보다 우열정도의 차이가 적었고 화본과초종은 두과초종에 대해 우점종이었으며 그 중 오차드그라스가 가장 우점력이 큰 초종으로 냐타딘고 알팔파는 가장 낮은 초종이었다. 한편 혼파의 경우 조합능력을 나타내는 혼생능력에서는 토올페스큐가 가장 켰으며 그 다음이 오차드그라스였고 라디노클로버는 가장 적은 것으로 나타났다. 조합별 혼생능력은 동일과간혼파조합이 불리한 것으로 나타났으며 화본과와 두과가 혼합된 조합이 불리하게 나타났는데 그 중 토올페스큐와 라디노는 혼생능력이 가장 큰 조합이었다. 지하부 경합에서도 지상부와 마찬가지로 토올페스큐-라디노혼파가 RYT가 가장 크고 혼생능력도 큰조합이었으며, 4초종중 오차드그라스가 우점력이 가장 컸고 근부의 혼생능력에서도 지상부와 달리 오차드그라스가 가장 큰 초종이었다.

• 한국운동역학회지
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• 제15권1호
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• pp.111-125
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• 2005

This study was intended to assist athletes in having a technical understanding of the Yega motion and provide basic material for improving their competitive ability by analyzing the kinematic variable of the Yega motion during the competition of the uneven parallel bar of female gymnastics. For this purpose, the game of female gymnastics participating in the uneven parallel bar game was personally videotaped using the DLT(direct linear transformation) method. An attempt was made to make a comparative analysis of the Yega motion by dividing the final first to third places into the upper group('A' group) and the sixth to eighth places into the lower group('B' group). Based on the results of actual analysis on the scenes of actual game, the following conclusion was concluded: 1. Athletes in the 'A' group showed the shorter required time on the flight phase(P3) than counterparts in the 'B' group. 2. Athletes in the 'A' group showed the little width in the horizontal displacement of the center of gravity than counterparts in the 'B' group. But athletes in the 'A' group exhibited the somewhat greater relative vertical height of the center of the body. 3. Athletes in the 'A' group showed the greater resultant velocity at the lowest point of the center of the body(E2) and at the point in time of release(E3) compared to counterparts in the 'B' group.

• 한국농공학회지
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• 제36권2호
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• pp.88-95
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• 1994

This paper is to evaluate the applicability of neural networks to the estimation of evapotranspiration. Two neural networks were developed to forecast daily evapotranspiration of the rice crop with back-propagation and counter-propagation algorithm. The neural network trained by back-propagation algorithm with delta learning rule is a three-layer network with input, hidden, and output layers. The other network with counter-propagation algorithm is a four-layer network with input, normalizing, competitive, and output layers. Training neural networks was conducted using daily actual evapotranspiration of rice crop and daily climatic data such as mean temperature, sunshine hours, solar radiation, relative humidity, and pan evaporation. During the training, neural network parameters were calibrated. The trained networks were applied to a set of field data not used in the training. The created response of the back-propagation network was in good agreement with desired values and showed better performances than the counter-propagation network did. Evaluating the neural network performance indicates that the back-propagation neural network may be applied to the estimation of evapotranspiration of the rice crop. This study does not provide with a conclusive statement as to the ability of a neural network to evapotranspiration estimating. More detailed study is required for better understanding and evaluating the behavior of neural networks.

• 대한안전경영과학회지
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• 제16권4호
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• pp.295-303
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• 2014

In this paper, due to the instability of the domestic market, global competition is intensifying in the current situation of global capacity building of SMEs for the purpose of developing a diagnostic indicator placed on the purpose. In this model, the results of applying several companies overall global innovation pilot enterprises and non-rated global innovative companies awarded significant difference between the score and the ability to believe the show. Non-global innovation companies, the relative firm size factor and R&D investment and patent number of factors are lacking appeared shone This is a common small business nature of the majority of companies small and R&D investment, the absolute amount is insufficient to reflect that, but the global innovator in the case of firm size and the relatively large amount of investment that never shows.