• Title/Summary/Keyword: modelling studies

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Goal, Structure, and Recent Development of the GLOBEC Programme (GLOBEC 프로그램의 목적, 운영체계 및 최근의 동향에 대하여)

  • Kim, Su-Am
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.5 no.1
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    • pp.10-15
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    • 2000
  • Goals, research direction, and operational structure of the Global Ocean Ecosystem Dynamics (GLOBEC), which is co-sponsored by the Scientific Committee on Oceanic Research (SCOR) and the Intergovemmental Oceanographic Commission (IOC), are described. Following the Joint Global Ocean Flux Study (JGOFS) activities on the lower trophic level in ecosystem during 1980s-90s, scientists have considered the responses of the mid and higher trophic levels to the environmental or climate change. The scientific steering committee of the GLOBEC published the implementation plan in 1999, and the IGBP will support the GLOBEC as one of its core projects for 10 years. The GLOBEC programme has four major components: the research foci, framework activities, regional programmes, and integrating activity. The core of GLOBEC research is the four research foci: retrospective analyses, process studies, predictive and modelling capabilities, and feedbacks. Currently, four regional programmes have been undergoing in the world ocean: Southern Ocean GLOBEC (SO-GLOBEC), Small Pelagic Fishes and Climate Changes (SPACC), Cod and Climate Change (CCC), and Climate Change and Carrying Capacity (CCCC). Also, national GLOBEC programmes were already established in 9 nations.

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Internet Worm Propagation Model Using Centrality Theory

  • Kwon, Su-Kyung;Choi, Yoon-Ho;Baek, Hunki
    • Kyungpook Mathematical Journal
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    • v.56 no.4
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    • pp.1191-1205
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    • 2016
  • The emergence of various Internet worms, including the stand-alone Code Red worm that caused a distributed denial of service (DDoS), has prompted many studies on their propagation speed to minimize potential damages. Many studies, however, assume the same probabilities for initially infected nodes to infect each node during their propagation, which do not reflect accurate Internet worm propagation modelling. Thus, this paper analyzes how Internet worm propagation speed varies according to the number of vulnerable hosts directly connected to infected hosts as well as the link costs between infected and vulnerable hosts. A mathematical model based on centrality theory is proposed to analyze and simulate the effects of degree centrality values and closeness centrality values representing the connectivity of nodes in a large-scale network environment on Internet worm propagation speed.

An Alternative Model on Hierachial Settlement System in Rural Areas (농어촌지역 하위정주체계 모형의 대안설정)

  • 최수영
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.32 no.4
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    • pp.61-70
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    • 1990
  • In rural settlement planning, its spatial development framework should be constructed on the basis of the hierachial settlement system. However, up to now, there does not exist widely - accepted model on rural settlement hierachy. In this study the basic planning principles and directions on the modelling of the settlement hireachy in rural areas have been consolidated through theoretical study and situational analysis on planning environments. And also, a new yardstick on the grading of the middle - level centers between villages and rural towns has been tried to find out. The research resulted that the existance of periodical rural market might be used as a simple and innovative yardstick on the hierachial ordering of rural settlement system. Based on the above results, an alternative 4 - step model of rural settlement hierachy was proposed ; Rural Town(county hall sitted) -Market Center(having standard periodical market) - Village Center(having no market) - Village. Finally, because the conclusion has been made by very limited case studies and several previous works, there should need continuous studies and checks in future for full reasoning of the proposed model.

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A Multi-stage Multi-criteria Transshipment Model for Optimal Selection of Transshipment Nodes - Case of Train Ferry-

  • Kim, Dong-Jin;Kim, Sang-Youl
    • Journal of Navigation and Port Research
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    • v.33 no.4
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    • pp.271-275
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    • 2009
  • A strategic decision making on location selection for product transportation includes many tangible and untangible factors. To choose the best locations is a difficult job in the sense that objectives usually conflict with each other. In this paper, we consider a multi stage multi criteria transshipment problem with different types of items to be transported from the sources to the destination points. For the optimization of the problem, a goal programming formulation will be presented in which the location selection for each product type will be determined under the multi objective criteria. In the study, we generalize the transshipment model with a variety of product types and finite number of different intermediate nodes between origins and destinations. For the selection of the criteria we selected the costs(fixed cost and transportation cost), location numbers, and unsatisfied demand for each type of products in multi stage transportation, which are the main goals in transshipment modelling problems. The related conditions are also modelled through linear formats.

Protein-Protein Interaction Analysis of Corticotropin - Releasing Hormone Receptor 1 with Corticotropin-Releasing Hormone and Sauvagine

  • Nagarajan, Santhosh Kumar
    • Journal of Integrative Natural Science
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    • v.11 no.2
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    • pp.101-106
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    • 2018
  • Corticotropin - releasing hormone receptor 1 (CRHR1) forms an integral part of the pathophysiology of disorders like post-traumatic stress disorder, stress, anxiety, addiction, and depression. Hence it is essential to look for new, potent and structure-specific inhibitors of CRHR1. We have analysed the protein-protein interaction complexes of the CRHR1 receptor with its native ligand CRF and full agonist Sauvagine. The structure of Sauvagine was predicted using homology modelling. We have identified that the residues TYR253, ASP254, GLU256, GLY265, ARG1014 and LY1060 are important in the formation of protein-protein complex formation. Future studies on these residues could throw light on the crucial structural features required for the formation of CRHR1-inhibitor complex and in studies that try to solve the structural complexities of CRHR1.

A Study on the Approaching to School Algebra (학교 대수 도입과 관련된 논의)

  • Kim, Sung-Joon
    • School Mathematics
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    • v.4 no.1
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    • pp.29-47
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    • 2002
  • The purpose of this study is to investigate various perspectives on the approaching to school algebra. School algebra plays an important role in school mathematics, but many students have been in difficulties for the loaming of school algebra. This problem has been continued for the long time. This paper supposed that this problem may be caused by the approaching stage to the school algebra. In order to investigate this problem, we first described the definition of algebra in chapterII. And in chapterIII, we divided the perspectives of approaching to the school algebra into the two parts. The one is the intrinsic nature of algebra, i.e. generalization, abstraction, and structural aspects. The other is the extrinsic representation of algebra, i.e. problem solving, modelling, functions. Each perspectives are investigated through various research studies. We hope that this works on each perspectives help a teacher prepare school algebra.

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Avoiding Hybrid Clauses Pitfalls: An Applied Framework

  • Lee, Arvin;Ma, Maggie
    • Journal of Arbitration Studies
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    • v.25 no.3
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    • pp.3-31
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    • 2015
  • This paper sets out a multi-dimensional approach that parties drafting a "hybrid clause" for their arbitration agreement can adopt, for purposes of maximizing enforceability, taking into account the multi-jurisdictional interplay between the seat Court, the governing law and the enforcement Court(s), as well as mandatory rules that can be present in the lex arbitrii, the governing law, and/or the law of the enforcement for a. This paper draws on both the co-authors' practice experience, as well as first principles of party autonomy in light of mandatory rules, based predominantly on the scholarship of Briggs and Nygh.

Modelling AC Electric Railway System using the PSCAD/EMTDC (PSCAD/EMTDC를 이용한 교류 전철급전시스템 모델링)

  • Lee, Han-Min;Chang, Sang-Hoon;Han, Moon-Seob;Kim, Joo-Rak;Oh, Kwang-Hae;Lee, Chang-Mu
    • Proceedings of the KIEE Conference
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    • 2002.04a
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    • pp.260-262
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    • 2002
  • This study presents a AC electric railway system model using PSCAD/EMTDC. Ver.3.08 for circuit analysis and fault studies. This system model made by PSCAD/EMTDC is composed of feeder, contact line, rails, Scott-transformer, Auto-transformer. This model is based on four-port network which is an extension of two-port network theory. In order to verify the proposed model, each voltage of feeder-rail, contact line-rail and feeder-contact line is measured and fault studies are also simulated.

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A Survey of Applications of Artificial Intelligence Algorithms in Eco-environmental Modelling

  • Kim, Kang-Suk;Park, Joon-Hong
    • Environmental Engineering Research
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    • v.14 no.2
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    • pp.102-110
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    • 2009
  • Application of artificial intelligence (AI) approaches in eco-environmental modeling has gradually increased for the last decade. Comprehensive understanding and evaluation on the applicability of this approach to eco-environmental modeling are needed. In this study, we reviewed the previous studies that used AI-techniques in eco-environmental modeling. Decision Tree (DT) and Artificial Neural Network (ANN) were found to be major AI algorithms preferred by researchers in ecological and environmental modeling areas. When the effect of the size of training data on model prediction accuracy was explored using the data from the previous studies, the prediction accuracy and the size of training data showed nonlinear correlation, which was best-described by hyperbolic saturation function among the tested nonlinear functions including power and logarithmic functions. The hyperbolic saturation equations were proposed to be used as a guideline for optimizing the size of training data set, which is critically important in designing the field experiments required for training AI-based eco-environmental modeling.

Joint HGLM approach for repeated measures and survival data

  • Ha, Il Do
    • Journal of the Korean Data and Information Science Society
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    • v.27 no.4
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    • pp.1083-1090
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    • 2016
  • In clinical studies, different types of outcomes (e.g. repeated measures data and time-to-event data) for the same subject tend to be observed, and these data can be correlated. For example, a response variable of interest can be measured repeatedly over time on the same subject and at the same time, an event time representing a terminating event is also obtained. Joint modelling using a shared random effect is useful for analyzing these data. Inferences based on marginal likelihood may involve the evaluation of analytically intractable integrations over the random-effect distributions. In this paper we propose a joint HGLM approach for analyzing such outcomes using the HGLM (hierarchical generalized linear model) method based on h-likelihood (i.e. hierarchical likelihood), which avoids these integration itself. The proposed method has been demonstrated using various numerical studies.