• Title/Summary/Keyword: inter-specific competition

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CONVERGENCE RESULTS FOR THE COOPERATIVE CROSS-DIFFUSION SYSTEM WITH WEAK COOPERATIONS

  • Shim, Seong-A
    • The Pure and Applied Mathematics
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    • v.24 no.4
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    • pp.201-209
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    • 2017
  • We prove convergence properties of the global solutions to the cooperative cross-diffusion system with the intra-specific cooperative pressures dominated by the inter-specific competition pressures and the inter-specific cooperative pressures dominated by intra-specific competition pressures. Under these conditions the $W^1_2-bound$ and the time global existence of the solution for the cooperative cross-diffusion system have been obtained in [10]. In the present paper the convergence of the global solution is established for the cooperative cross-diffusion system with large diffusion coefficients.

Effects of periodic air-exposure and nutrients on the competition of Ascophyllum nodosum and Fucus vesiculosus germlings

  • Park, Seo Kyoung;Choi, Han Gil;Nam, Ki Wan
    • Korean Journal of Environment and Ecology
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    • v.29 no.1
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    • pp.7-13
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    • 2015
  • To examine the relationship between competition and environmental factors, the germlings of Ascophyllum nodosum (L) Le Jolis and Fucus vesiculosus L. were cultured in monocultures and mixtures of the two species under two different exposure and nutrient levels. Both intra- and inter-specific competition were examined in comparison of the mortality and growth of germlings in monocultures and mixtures of the two species. The mortality of germlings increased with increasing density and emergence periods both in the monoculture and mixtures of the two species, and the mortality of Ascophyllum was significantly higher than that of Fucus both in submerged and emerged treatments. The growth of germlings of both species reduced with increasing density but F. vesiculosus always grew faster than Ascophyllum. The values of log output ratio were more than 0.1, indicating that Fucus 'won' in the competitive battles with Ascophyllum under two nutrient- and air-exposure levels. Log output ratio was greater in high than in low nutrients, indicating that the growth of Fucus is more enhanced than that of Ascophyllum in high nutrients. In the present study, the outcome of inter specific competition between germlings of Fucus vesiculosus and Ascophyllum nodosum was slightly altered by duration of emergence and nutrient concentration, but not to such an extent as to change the outcome.

Evolution of Inter-firm Technology Transfer and Technological Capability Formation of Local Parts Firms in the Thai Automobile Industry

  • Techakanont, K.;Terdudomtham, T.
    • Journal of Technology Innovation
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    • v.12 no.2
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    • pp.151-183
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    • 2004
  • This paper investigates the evolution of 'inter-firm' technology transfer in the Thai automobile industry, which has gradually been integrated into global production network of some specific automotive models(one-ton pickups). This paper discusses the linkage between the role of automobile assemblers in transferring technology and the way their strategic changes bring about heightened demands on the technological capacity of suppliers and the contents of technology transfer. With higher competition at the global level, local suppliers are required to improve their technical and managerial skills, especially in the area of 'product engineering' capability. The authors examine the ways local firms have adapted to these changes in their environments, as well as the ways they utilize inter-firm relationship with automobile assemblers as a means to improve their own technological capabilities. The dynamic process of capability formation in local parts firms, through intensive efforts and learning inducements brought about by inter-firm relationships, are also discussed.

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Analysis of Inter-Domain Collaborative Routing: Provider Competition for Clients

  • Nicholes, Martin O;Chuah, Chen-Nee;Wu, Shyhtsun Felix;Mukherjee, Biswanath
    • Journal of Communications and Networks
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    • v.13 no.5
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    • pp.499-510
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    • 2011
  • Any server offering a routing service in the Internet would naturally be in competition for clients, and clients may need to utilize service from a specific server in order to achieve a desired result. We study the various properties of this competition, such as the fraction of route requests handled by a routing service provider and the fraction of total revenue obtained. As the routing service providers (i.e., servers or routers in this context) compete, they may alter behavior in order to optimize one of the above properties. For example, a service provider may lower the price charged for its service, in order to increase the number of clients served. Our models are based on servers offering a routing service to clients within representative network topologies based on actual Internet sub-graphs. These models provide, a framework for evaluating competition in the Internet. We monitor key aspects of the service, as several variables are introduced into the models. The first variable is the fraction of client requests that will pay more for a better quality route. The remaining requests are normal client requests that are satisfied by the most economical route. The second variable is the fraction of servers who choose to lower service prices in order to maximize the number of client requests served. As this fraction increases, it is more likely that a server will lower the price. Finally, there are some resource constraints applied to the model, to increase the difficulty in providing a routing solution, i.e., to simulate a realistic scenario. We seek to understand the effect on the overall network, as service providers compete. In simple cases, we show that this competition could have a negative impact on the overall efficiency of a service. We show that the routing variety present in the larger models is unable to mask this tendency and the routing service performance is decreased due to competition.

Reproductive Growth and Competitive Ecology of Arrowhead (Sagittaria trifolia L.) - 2. Competition Ecology of Arrowhead (벗풀(Sagittaria trifolia L.)의 번식생장(繁殖生長) 및 경합생태(競合生態) - 2. 벗풀의 경합생태(競合生態))

  • Han, S.S.
    • Korean Journal of Weed Science
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    • v.13 no.2
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    • pp.151-158
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    • 1993
  • This experiment was conducted in order to understand the intra-and the inter-competition of arrowhead, Sagittaria trifolia L., under the conditions of arrowhead monoculture and rice-mixed culture, respectively. In arrowhead monoculture, the infra-specific competition in both shoot length and floral axis number began at 10 plants per $0.5m^2$ and that in leaf number, leaf length, dry shoot weight and formated tuber number did at 5 plants per $0.5m^2$. In the inter-specific competition according to arrowhead density in the constant rice-mixed culture, the plant height and the tiller number of rice decreased at 15 and 5 plants of arrowhead per $0.5m^2$, respectively. The dry top weight and the formated tuber number of arrowhead decreased with increase of arrowhead density. In the inter-competition according to rice plant density in the constant arrowhead-mixed stands, the dry matter weight and the produced tuber number of arrowhead decreased with increase of rice plant density and the plant height and the tiller number of rice also did with that. In the different transplantation time of rice, the growth in arrowhead became less in order of late transplantation>standard one>early one and the plant height and the tiller number of rice became more in order of that by comparing the percentage of growth under the mixed culture to that under the arrowhead monoculture.

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Diet Partitioning between Co-occurring Amblychaeturichthys hexanema and Amblychaeturichthys sciistius in the Southeastern Korean Waters (동해 남부 연안에 출현하는 도화망둑 (Amblychaeturichthys hexanema)과 수염문절(Amblychaeturichthys sciistius)의 먹이 분할)

  • Huh, Sung-Hoi;Park, Joo Myun;Baeck, Gun Wook
    • Korean Journal of Ichthyology
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    • v.28 no.2
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    • pp.79-86
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    • 2016
  • Stomach contents of Amblychaeturichthys hexanema and A. sciistius (Perciformes: Gobiidae) from southeastern waters off Korea were analyzed to determine dietary habits and the presence of any inter- and intra-specific partitioning of food resources. These two species were bottom-feeding carnivores that consumed mainly benthic crustaceans, and other demersal invertebrates and planktonic organisms were also important in their diets. Non-metric multidimensional scaling (nMDS) ordination and multivariate analyses based on gravimetric contributions of the different prey taxa to stomach contents revealed significant inter-specific dietary differences; i.e. partitioning of food resources between the two species. Size-related changes, however, were not significant for their diets. Differences in the types and range of prey ingested by the two species could often be related to differences in the feeding behaviors. Our results of stomach contents analyses provide clear evidence of niche segregation between co-occurring A. hexanema and A. sciistius in southeastern Korean waters, which would reduce the likelihood of inter-specific competition for food resources.

Feeding Relationship between Co-occurring Silver Croaker (Pennahia argentata) and Japanese Sillago (Sillago japonica) in the Nakdong River Estuary, Korea (낙동강 하구역에 출현하는 보구치(Pennahia argentata)와 청보리멸(Sillago japonica)의 섭식관계)

  • Huh, Sung-Hoi;Choi, Hee Chan;Park, Joo Myun
    • Korean Journal of Ichthyology
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    • v.30 no.4
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    • pp.224-231
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    • 2018
  • Dietary niches can support the coexistence of sympatric species in marine ecosystems, which can lead to the presence of greater abundances of those species. Stomach contents of silver croaker (Pennahia argentata) and Japanese sillago (Sillago japonica) inhabiting the Nakdong River estuary, Korea were analyzed to determine diet compositions and the presence of any size-related and inter-specific feeding relationships. These species were bottom-feeding predators that consumed mainly benthic crustaceans and mollusks, but polychaetes were also important in the S. japonica diets. Non-metric multidimensional scaling (nMDS) ordination and multivariate analyses based on weight contributions of the different prey taxa to stomach contents revealed significant inter-specific dietary differences. Size-related change was also significant for P. argentata diets, but not for S. japonica. Canonical analysis of principal coordinate (CAP) ordination plot further demonstrated that differences in the type and range of prey ingested by the two species contributed such an inter-specific difference in the diet compositions. The results from this study provide clear evidence of niche segregation between co-occurring P. argentata and S. japonica in the Nakdong River estuary, which would reduce the likelihood of inter-specific competition for food resources.

The Dynamics of Film Genre Box Office Success: Macro-Economic Conditions, Fashion Momentum, and Inter-Genre Competition (영화 장르 흥행의 동학: 거시경제, 유행의 동력, 장르 간 경쟁의 효과)

  • Dong-Il Jung;Yeseul Kim;Chaewon Ahn;Youngmin Park
    • The Journal of the Convergence on Culture Technology
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    • v.9 no.2
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    • pp.389-397
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    • 2023
  • This study examines how macro-economic conditions, fashion momentum, and inter-genre competition affect movie genre's popularity, thus shaping fashion trends in the feature film market in Korea. Using panel data analysis of genre-specific audience sizes with 6 genre cateories and 132 monthly time points, we found that favorable economic conditions generate the fashion trend in the action/crime genre, while the deterioration of the economic conditions leads to the decline of action/crime genre. The finding implies that economic situations influence cultural consumers' psychological states, which in turn shape the fashion trend in certain direction. Furthermore, we found that the action/crime genre has a greater fashion momentum and its competitive power is stronger than other genres, suggesting that this genre has longer fashion cycle even if other genres rise to the top in their popularity. We argue that such enlengthened fahion cycle and competitive stength of the action/crime genre are associated with its breadth of niche width and audience loyalty. Scholarly and practical implications are discussed.

Intra- and Inter-specific Competition of Bulrush(Scirpus juncoides Roxb.) (올챙고랭이(Scirpus juncoides Roxb.)의 종내(種內) 및 종간경합(種間競合)에 관한 연구(硏究))

  • Guh, J.O.;Huh, S.M.
    • Korean Journal of Weed Science
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    • v.9 no.2
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    • pp.168-173
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    • 1989
  • In the characteristics of intra-specific competition according to bulrush density, the intra-specific competition in plant height began at 5 and 15% per pot in mixed culture and bulrush monoculture, respectively. The intra-specific competition in the shoot began at 5 plants per pot in both mixed culture and bulrush monoculture. The competition in dry matter weight began at 15 plants per pot in monoculture, and at 10 plants in mixed culture. On the rice density, the plant height, and numbers of shoot and dry matter weight in rice were rapidly increased up to 2.6, and 2.5 plants per pot, respectively, And then the increments were slow, The critical intra-specific competition of bulrush with rice was 2.5 to 3 plants per pot in their traits of rice, and especially the number of shoots and dry matter weights per pot showed significant decrements. In the different transplanting time in rice, the plant heights in both rice and bulrush elongated longer in mixed culture than in monoculture. The plant height of bulrush became shorter but the height of rice longer with late transplanting. The ratio of shoot number in rice to the number in bulrush was about 1 : 3 in all plots, and shoot numbers became less by late transplanting. The dry matter weight in both species were decreased by late transplanting, and the decrements were more prominent in bulrush than in rice.

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A Study on the Improvement of Inter-Terminal Transportation Using Buffer Space (완충지역을 활용한 타부두 환적 컨테이너 운송 개선 방안)

  • Park, Hyoung-Jun;Shin, Jae-Young;Choi, Yang-Ho
    • Journal of Navigation and Port Research
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    • v.45 no.6
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    • pp.314-324
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    • 2021
  • Competition between ports around the world is intensifying to attract transshipment cargo. However, recently, there have been concerns about the departure of transshipment cargo volume at Busan Port, such as the lifting of the cabotage policy in China's shipping sector and the implementation of a safe fare system. In terms of operation, terminal congestion and vehicle waiting time are seriously occurring due to imbalance in the transshipment volume of each terminal and vehicles concentrated in a specific time period. In this paper, we propose a method of inter-terminal transportation (ITT) using buffer space to solve the problem caused by inefficient ITT systems and presented a mixed integer programming (MIP) for the problem. The effect of using the buffer space was analyzed for various work volumes and capacity fluctuation ranges by applying the terminal congestion pattern and ITT vehicle in/out pattern based on the Busan New Port data.