• Journal of Ecology and Environment
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• v.44 no.3
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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.

• 한국신재생에너지학회:학술대회논문집
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• 2007.11a
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• pp.573-576
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• 2007

가스 하이드레이트의 구조-I 및 구조-H의 공존 현상을 13C NMR과 Raman spectroscopy를 이용하여 분석하였다. 하이드레이트 생성 조건이 구조-H 영역에만 있을 때는 CH4+neohexane 혼합 하이드레이트가 구조-H만을 나타냈지만, 구조-I의 영역에서는 구조-H의 혼합 하이드레이트와 구조-I의 순수 메탄 하이드레이트가 공존하는 것을 $^{13}C$ NMR spectra를 통해 확인하였다. 이러한 현상은 구조-H 생성자로 알려진 isopentane, MCP, MCH 에서도 관찰되었으며, Raman spectroscopy를 이용해서도 확인할 수 있었다.

• Journal of applied mathematics & informatics
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• v.28 no.5_6
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• pp.1379-1393
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• 2010

In this paper, a stage-structured predator prey model (stage structure on prey) with two discrete time delays has been discussed. The two discrete time delays occur due to maturation delay and gestation delay. Linear stability analysis for both non-delay as well as with delays reveals that certain thresholds have to be maintained for coexistence. Numerical simulation shows that the system exhibits Hopf bifurcation, resulting in a stable limit cycle.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.49 no.3
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• pp.1-7
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• 2012

In this paper, we consider a channel selection method for the coexistence of heterogeneous systems in the TV white space (TVWS). First, we define the target heterogeneous system structure. Then, under the defined system structure, we discuss how the heterogeneous systems share the TVWS channels. Specifically, the heterogeneous systems having different bandwidths cannot use the TVWS channels due to the lack of wideband channels when only narrowband channels are remained. Hence, in order to minimize the blocking from the different bandwidth problem, we propose a channel selection method for the narrowband systems to firstly occupy the narrowband channels rather than the wideband channels. The proposed narrowband-first channel selection is shown to enhance the spectral efficiency of the TVWS, especially in the IEEE 802.19.1 wireless coexistence system.

• 한국초전도학회:학술대회논문집
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• v.9
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• pp.196-199
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• 1999

The coexistence of the superconductivity and magnetism in the Ho1-xDyxNi2B2C is studied by using Ginzburg-Landau theory. This material violates the standard do Gennes scaling showing the coexistence and complex interplay of superconducting and magnetic order yielding an anomalous phase diagram. We propose a phenomenological model which includes two magnetic and two superconducting order parameters accounting for the multi-band structure of this material. We describe the magnetic fluctuations and order and demonstrate that they lead to anomalous behavior of the upper critical field. The doping dependence of Tc in Ho1-xDyxNi2B2C showing a reentrance behavior are analyzed yielding a very good agreement with experimental data.

• Journal of English Language & Literature
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• v.64 no.4
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• pp.551-564
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• 2018

Laodiceanism is the blueprint from which Hardy draws one of his most ingenuous effects: the creating of a Laodicean around which the novel constructs its ambiguity. Hardy's command of "ingenuity" joins both the leading heroine Paula and the minor character Dare into the same category of a Laodicean. Alongside Paula, Dare is the most important ingredient in the novel in that he acts as an enigmatic persona defying the reader's attempts to establish a coherent type. This paper aims to offer a close reading of Dare's life story, which is chosen for discussion as he has been deemed as a simple functionary and thus apparently escaped serious critical notice thus far. It is stressed that the structure of sensations Dare embodies is fascinating in the sense that it is a locus where the coexistence of both meaning and nonmeaning would not amount to harmonious peace or stability so much as permits the impossibility of single and central significance. In this coexistence is inscribed a notion that the binaries in opposition are endlessly inter-mingled in dialogic tension, which is the hallmark of Laodiceanism that Hardy aims to present through the creation of Dare.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2006.06b
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• pp.273-278
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• 2006

In this study, it is purpose that value-added-logistics strategy plan for cooperation and coexistence in northeast asia.. Because of the change of domestic industrial structure, Japan's super hub port plan, Yangshan Deepwater port open of china and domestic port logistics industries are faced with competition among northeast asia countries. Decreasing export volume of changed domestic industrial structure and two countries: japan, china, make a new port policy and build new ports will affect domestic port logistics industries because these industries depend on container throughput at Busan port. Now, we cannot get a lot of profit from container throughput more than before and in the future China has more ports most ships direct calling in china's port to handle china's cargo volume to get more profit at that time our plans to become a hub port in northeast need revision. Finally, we need a new strategy which is value-added-logistics strategy. But it considers cooperation and coexistence among northeast countries. So this paper suggests that value-added-logistics strategy plan for cooperation and coexistence to live in affluence together in the future.

• The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.2 s.58
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• pp.38-49
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• 2006

In order to increase the spectrum efficiency, recently, there is the number of studies for CR technology. For instance, IEEE 802.22 WRAN(Wireless Regional Area Network) WG considered the CR technology as a solution of WRAN system to serve the high speed internet service(1.5 Mbps down stream and 384 kbps up stream) in 100 km overall coverage and 54 MHz-746 MHz band. Basically, in MAC point of view, the WRAN system have been standardizing based on the IEEE 802.16 MAC layer features such as Data transmission method, QoS provision and Bandwidth request schemes. Additionally, the WRAN system further include CR nature functions such as incumbent user protection, self coexistence which would be importantly considered. Also, the inherent WRAN functions are added such as channel bonding and fractional bandwidth usage. This paper mainly explained frame structure, IU protection, self coexistence which are key functions of WRAN system. Finally, in this paper, we expressed a prospect of IEEE 802.22 WRAN standardization.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2006.07a
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• pp.270-270
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• 2006

• English & American cultural studies
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• v.14 no.1
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• pp.1-26
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• 2014

Multicultural theories fully fledged around the 1980s and the early 1990s. Emerging in the 1960s thanks to the Civil Rights movement, multiculturalism has become the grand American national narratives, whose tenets recognize and respect people with diverse racial and cultural backgrounds. This period, however, witnessed the eruption of violent and destructive rebellions or uprisings involving racial minorities. Racial conflicts and tensions exploded at the moment when multiculturalism was widely practiced in areas including education and public policy revealing that complicated problems are embedded in the urban ghettos. American popular culture, specifically addresses antagonisms among different races or ethnicities in Bed-Stuy in New York. Although the film is mainly concerned with the collision among races, it lets ambivalent and cacophonous values and ideologies be present in the black community. On the other hand, Ice Cube's "Black Korea" empowers the black community when it deals with the turbulent relationship between black residents and Korean American merchants. Simultaneously, it denigrates Korean Americans as gasta raps often target the institution like government or police. In short, while attempts to search the ideas of coexistence and juxtaposition through polyphonic features embodied in the film "Black Korea" seems to depend on the dualistic system when it deals with the black-Korean conflicts and as a result it just reveals the chasm between two communities.