• Title/Summary/Keyword: Long-term dynamics

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Chronic Effect Exposed to Carbon Dioxide in Benthic Environment with Marine Invertebrates Copepod(Tisbe sp.) and Amphipod(Monocorophium acherusicum) (저서환경에서 이산화탄소 노출에 따른 국내산 해산무척추동물 요각류(Tisbe sp.)와 단각류(Monocorophium acherusicum)의 만성영향)

  • Moon, Seong-Dae;Choi, Tae Seob;Sung, Chan-Gyoung;Lee, Jung-Suk;Park, Young-Gyu;Kang, Seong-Gil
    • Journal of Environmental Science International
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    • v.22 no.3
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    • pp.359-369
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    • 2013
  • Chronic effects such as reproduction and population dynamics with elevated $CO_2$ concentration were evaluated using two representative marine benthic species, copepod (Tisbe sp.) and amphipod (Monocorophium acherusicum) adopting long-term exposure. Juvenile copepod and amphipod individuals were cultivated in the seawater equilibrated with control air (0.395 mmol $CO_2$/air mol) and high $CO_2$ air having 0.998, to 3.03, 10.3, and 30.1 mmol $CO_2$/air mol during 20 and 46 days, respectively. After the exposure period, the number of benthic invertebrate was counted with separate larval and juvenile stage such as naupliar, copepodid and adult for copepod, or neonate and adult for amphipod, respectively. The individual number of both test species at each life-stage was significantly decreased in seawater with 10.3 mmol $CO_2$/air mol or higher. Recently, the technology of marine $CO_2$ sequestration has been developed for the reduction of $CO_2$ emission, which may cause climate change. However, under various scenarios of $CO_2$ leaks during the injection process or sequestrated $CO_2$ in marine geological structure, the potential risk to organism including various invertebrates can be expected to exposure. So the results of this study suggested that the detailed consideration on the adverse effect with marine ecosystem can be prerequisite for the marine $CO_2$ sequestration projects.

Dynamics of Attached Microbial Community on the River with Gravel Riverbed (자갈하상 하천에서 부착미생물군집의 거동)

  • Park, Jae-Young;Choi, I-Song;Oh, Jong-Min
    • Journal of Korea Water Resources Association
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    • v.38 no.3 s.152
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    • pp.235-244
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    • 2005
  • This study was carried out in Osan river to quantitatively investigate behavior of attacked microbial community (AMC) for enhancing self-purification process of river. We gained the results such as follows throughout long-term monitoring at in-situ river. The biomass of AMC had higher in the riffle than the almost stagnant pool and they were more developed in the riffle with high current velocity (HCV). Although the fast flowing current affects negatively to growth of the AMC during the early phase when the community gets attached to the benthic substrate, it was observed that it affected positively to their growth during the intermediate and later phase after the community is adapted to the substrate. When turbulence due to external pressure (storm or discharge of dam and reservoir) occurs, the degree of separation depends upon the flowing strength and the type of the external pressure. Since the community is not all separated, recovery is rather fast. Therefore, this study found that the degree of reduction of the pollutant by self-purification of the stream is depended upon the riverbed shape and the AMC contributes to self-purification positively or negatively in river. Therefore, the riverbed shape must be constructed in accordance with the characteristics of water quality in stream. Furthermore, the technique of installing the water channel structure appropriate for each section must be developed to maximize self-purification ability.

A SYSTEM DYNAMICS MODEL OF FOOD GRAIN PRODUCTION IN KOREA (양곡생산(糧穀生産)의 동적(動的) 모델에 관(關)한 연구(硏究))

  • Lee, Chong Ho
    • Journal of Biosystems Engineering
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    • v.8 no.1
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    • pp.61-69
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    • 1983
  • A system dynamic model was developed to predict food grain production under the dynamic consideration of the production circumstance and inputs such as farm population, investment on agriculture, arable land, extensive technology and weather. By using the model, the variation of the food grain production from 1978 to 2008 was examined. The results of the model output says it is desirable that the persistent and long-term program should be studied to get necessary food grain production under the variational inputs and circumstances.

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Emerging Media Conglomerates and Producers' Exodus: The Dynamics of Creativity Relocations in the South Korean Broadcasting Production Sector after the Introduction of New General Programming Channels (신규 복합 미디어 기업의 부상과 제작자 엑서더스: 종합편성채널 승인 이후 방송제작 부문의 창의성 재배치 동학)

  • Jung, June-Hee
    • Korean journal of communication and information
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    • v.66
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    • pp.28-58
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    • 2014
  • South Korean broadcasting industry has been under a significant level of structural change since the permission of new general programming channels in the end of 2010. One of the most characteristic features of the change may be the exodus of core manpower from the in-house productions of major terrestrial broadcasters which have been maintaining their dominant power over broadcasting content market based on their systems of tight vertical integration. This paper sheds light on the presence of a purposeful 'mechanism design' that aims to the expansion of market logics in South Korean broadcasting sector by promoting commercial media conglomerates, and analyses how this external design has been actualized while being interlocked with various internal factors of the broadcasting industry. This paper shows that on the backdrop of the mechanism design, some of new media conglomerates has successfully provided various incentives in contrast with those disincentive of terrestrial broadcasters, which in turn, has facilitated the exodus of elite producers. This paper, however, raises a set of questions about whether this relocation process of creativity led by commercial media conglomerates would, in the long term, guarantee more opportunities and potentials for the producers, as promised. As part of conclusion, inherent problems of present mechanism design are highlighted.

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On the Study of Developement for Urban Meteorological Service Technology (도시기상서비스 기술 개발에 관한 연구)

  • Choi, Young-Jean;Kim, Chang-Mo;Ryu, Chan-Su
    • Journal of Integrative Natural Science
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    • v.4 no.2
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    • pp.149-157
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    • 2011
  • Urbanization of the world's population has given rise to more than 450 cities around the world with populations in excess of 1 million (megacity) and more than 25 so-called metacities with populations over 10 million (Brinkhoff, 2010). The United States today has a total resident population of more than 308,500,000 people, with 81 percent residing in cities and suburbs as of mid - 2005 (UN, 2008). Urban meteorology is the study of the physics, dynamics, and chemistry of the interactions of Earth's atmosphere and the urban built environment, and the provision of meteorological services to the populations and institutions of metropolitan areas. While the details of such services are dependent on the location and the synoptic climatology of each city, there are common themes, such as enhancing quality of life and responding to emergencies. Experience elsewhere (e.g., Shanghai, Helsinki, Tokyo, Seoul, etc.) shows urban meteorological support is a key part of an integrated or multi-hazard warning system that considers the full range of environmental challenges and provides a unified response from municipal leaders. Urban meteorology has come to require much more than observing and forecasting the weather of our cities and metropolitan areas. Forecast improvement as a function of more and better observations of various kinds and as a function of model resolution, larger ensembles, predicted probability distributions; Responses of emergency managers, government officials, and users to improved and probabilistic forecasts; Benefits of improved forecasts in reduction of loss of life, property damage, and other adverse effects. A national initiative to enhance urban meteorological services is a high-priority need for a wide variety of stakeholders, including the general, commerce and industry, and all levels of government. Some of the activities of such an initiative include: conducting basic research and development; prototyping and other activities to enable very--short and short range predictions; supporting and improving productivity and efficiency in commercial and industrial sectors; and urban planning for long term sustainability. In addition urban test-beds are an effective means for developing, testing, and fostering the necessary basic and applied meteorological and socioeconomic research, and transitioning research findings to operations. An extended, multi-year period of continuous effort, punctuated with intensive observing and forecasting periods, is envisioned.

The Relational Role of Customer Participation in Interaction Process (상호작용과정에서 고객참여의 관계적 역할)

  • Ahn, Jinwoo;Oh, Hyung Jun
    • Management & Information Systems Review
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    • v.39 no.3
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    • pp.37-51
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    • 2020
  • Customer participation in the service encounter plays an important role in the interaction process. In addition, customer participation is affecting the development of relationships between customer-service provider. Previous researches revealed the role of customer participation through a fragmented and cross-sectional approach, however, given the dynamics of the relationship, it is necessary to identify the role of customer participation from a longitudinal perspective. In addition, it is necessary to determine the cause of the overlap between the antecedent variables and consequent variables. This study aims to identify the relational role of customer participation by clarifying how customer participation affects relationship development from a longitudinal perspective, focusing on trust and commitment variables which are keys to relationship marketing. The related role of customer participation is analyzed through a regression analysis through long-term data. The results of the study showed that commitment(t1) directly had a positive effect on customer participation. However, trust(t1) has been shown to have a direct positive effect on the sub-dimensions of customer participation, such as personal interaction and responsible behavior. Customer participation(t2) affected by this trust(t1) and commitment(t1) again turned out to have a positive effect on trust(t3) and commitment(t3). In conclusion, although customer participation is affected by the relational variables, it can be seen that customer participation is a major factor that can improve the relational variables again through the interaction process. For this reason, a service firm can seek to develop relationships with customers by drawing and utilizing their needs to exchange information and to interact in the service encounter.

Modeling and analysis of selected organization for economic cooperation and development PKL-3 station blackout experiments using TRACE

  • Mukin, Roman;Clifford, Ivor;Zerkak, Omar;Ferroukhi, Hakim
    • Nuclear Engineering and Technology
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    • v.50 no.3
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    • pp.356-367
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    • 2018
  • A series of tests dedicated to station blackout (SBO) accident scenarios have been recently performed at the $Prim{\ddot{a}}rkreislauf-Versuchsanlage$ (primary coolant loop test facility; PKL) facility in the framework of the OECD/NEA PKL-3 project. These investigations address current safety issues related to beyond design basis accident transients with significant core heat up. This work presents a detailed analysis using the best estimate thermal-hydraulic code TRACE (v5.0 Patch4) of different SBO scenarios conducted at the PKL facility; failures of high- and low-pressure safety injection systems together with steam generator (SG) feedwater supply are considered, thus calling for adequate accident management actions and timely implementation of alternative emergency cooling procedures to prevent core meltdown. The presented analysis evaluates the capability of the applied TRACE model of the PKL facility to correctly capture the sequences of events in the different SBO scenarios, namely the SBO tests H2.1, H2.2 run 1 and H2.2 run 2, including symmetric or asymmetric secondary side depressurization, primary side depressurization, accumulator (ACC) injection in the cold legs and secondary side feeding with mobile pump and/or primary side emergency core coolant injection from the fuel pool cooling pump. This study is focused specifically on the prediction of the core exit temperature, which drives the execution of the most relevant accident management actions. This work presents, in particular, the key improvements made to the TRACE model that helped to improve the code predictions, including the modeling of dynamical heat losses, the nodalization of SGs' heat exchanger tubes and the ACCs. Another relevant aspect of this work is to evaluate how well the model simulations of the three different scenarios qualitatively and quantitatively capture the trends and results exhibited by the actual experiments. For instance, how the number of SGs considered for secondary side depressurization affects the heat transfer from primary side; how the discharge capacity of the pressurizer relief valve affects the dynamics of the transient; how ACC initial pressure and nitrogen release affect the grace time between ACC injection and subsequent core heat up; and how well the alternative feeding modes of the secondary and/or primary side with mobile injection pumps affect core quenching and ensure stable long-term core cooling under controlled boiling conditions.

Recent Progress and Tasks of Arms Control in South and North Korea (최근 남북한 군비통제의 추진현황과 과제)

  • Kim, Kang-nyeong
    • Korea and Global Affairs
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    • v.3 no.2
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    • pp.87-130
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    • 2019
  • This paper aims to analyze the recent progress(current situation) and tasks of arms control in North and South Korea. To this end the paper is composed of 5 chapters titled instruction; recent progress(current situation) of arms control in South and North Korea; constraints and tasks of arms control on the Korean peninsula; and conclusion. One of the most important tasks for the establishment of a peace structure for the coexistence of the Korean people in the 21st century is the realization of military control in order to resolve the acute military confrontation situation and mutual threats. With the 2018 PyeongChang Winter Olympics, the North-South summit and the subsequent talks for peace and denuclearization on the Korean Peninsula, the North Korea-US summit, and subsequent talks are creating conditions for trust building and arms control between the two Koreas. The military trust between the two Koreas and operational arms control are being achieved through the declaration of the April 27 Panmunjom and the 'Military Agreement for the Implementation of the Panmunjom Declaration.' However, since there are constraints on the control of arms control, such as the persistence of hostility and distrust of the two Koreas, the defense treaty between the two Koreas and neighboring countries, the competition of neighboring countries and the complex interests of the Korean peninsula, Trust Building is important. We should resolve the issue of arms control between the two Koreas, taking into account the trend of international arms control over the internal and external dynamics of the Korean peninsula gradually and carefully, with a vision of long-term unification security.

Structurization in Community Composition and Diversity Pattern of Soil Seed Banks in Gwangneung Forest, South Korea (한국 광릉숲 매토종자에서 군집 종조성 및 다양성 양상의 구조화)

  • Kim, Han-Gyeol;Oh, Seung-Hwan;Cho, Yong-Chan
    • Journal of Korean Society of Forest Science
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    • v.110 no.4
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    • pp.577-589
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    • 2021
  • Soil seed bank community contributes to the long-term conservation of plant diversity and vegetation dynamics, and their decreasing diversity and density with soil depth provide critical perspectives (deterministic and stochastic) for understanding the community disassembly process. We analyzed changes in species composition and diversity and structuring patterns by soil layer (top and bottom), including surface vegetation, in Gwangneung Forest, a mature forest with a vegetation climate in the temperate central part of the Korean Peninsula. From two layers of soil collected with a vertical difference of 10 cm, 934 specimens of 27 families, 40 genera, 44 species, three varieties, and 47 taxa, germinated. Although species diversity and germination density decreased in most comparative characteristics, including growth type, there was no statistical significance due to large deviations. Within-group variability of species composition was similar in the upper and lower soils, as was the decline pattern in co-occurred species (ζ-diversity) and change in species retention probability. The structuring process of the community composition in the two soil layers was fitted with an exponential correlation rather than a power function, demonstrating the dominance of the stochastic process. The pattern in diversity and species turnover according to soil depth in Gwangneung Forest was discovered to be structured by stochastic random events, such as seed vertical movement rather than interaction with trait characteristics.

EDMS and Life-cycle of Records (EDMS와 기록물의 라이프사이클)

  • Kim, Ik-han
    • The Korean Journal of Archival Studies
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    • no.5
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    • pp.3-37
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    • 2002
  • Today the market of EDMS is esteemed more than 100 billions won. It signifies a comming of age of electronic records. The traditional archival theories which are based on the paper records are confronted with a new challenge. In some leading countries of archival studies reorientation of archives management has been tried by a number of distinguished specialists such as Bearman and Hedstrom since 10 years. As a consequence new paradigm of archival theories has been developed. Also in Korea this new paradigm has been introduced by some expert such as Lee, Sang-Min, Sul, Moon-won, Lee, Seung-Eok. However their arguments are too general to offer a concrete clue for new paradigm. Faced by new age of electronic records, it's important to start a discussion for the reasonable methods of electronic records management at once. The most drastically changed part of record management by the electronic technique is the life-cycle of records. The commonly practiced three-stage life-cycle is to be reduced to the two-stage life-cycle, and the concept of the spatial movement of records is to be changed. It can be also pointed that the public emerges as user from the early creating stage of records beyond time and space. Thus is can be said that the method of the management features dynamic and cohesive. The method of appraisal must be also changed and reproduced, so that it can reflect the various levels considering dynamics of the electronic records. Supposedly it will be a core factor that causes the change of methodology in records management with the change of life-cycle theory. It must be noted that various subjects would be involved in the work of classification and description over time and space and that feedback between them is of important. Description also tends to be made at the crating stage of records and structured dynamically. It results from the change of life-cycle and the introduction of the concept of continuum. Such trend allows us to start discussions on the assumption that description of both creator and archival professionals act together an important role. Of course, it is linked with the methodology in which most descriptions are made automatically at the early drafting stage of the structure. The meat date is formed on the assumption that there should be feedback between areas of automatic description, description of creators and archival professionals. The most important thing in description is to develop a suitable way how it is structured. An alternative must be offered for managing data set. As iweb that is being operated by Myongji university shows, records created in daily business are managed not as electronic records but as date base. This is because they exist outside the repository in the EDMS system. Since data set often has various sources, an alternative for classification needs to be developed. It is now likely that database is filed according to the created year to be transferred automatically to the repository. Over a long-term the total management of database, electronic records and electronic information will be a topic. A right direction of new paradigm will be found for both iweb and E-government, when practice and studies of theories are combined and interacted.