• Journal of Korea Port Economic Association
• /
• v.29 no.4
• /
• pp.73-95
• /
• 2013

This paper analyzes a competitive shipping market in East Asia in order to explore how container carriers make decisions on ship size, number of ships, service frequency, and service route. A sequential-move game based on non-cooperative game theory is applied to establish the models for the decision-makings involving the transportation volumes, freight rates, costs, and market shares of the service routes from Shanghai or Hong Kong to the ports in Busan, Gwangyang, and Incheon. According to the sub-game perfect Nash equilibrium solutions proposed by these models, carriers' decisions in such a competitive environment vary depending on sailing distance, transport demand, and freight rates. Therefore, carriers are recommended to reflect the optimal equilibrium solutions and a variety of decision factors when formulating strategies for transportation networks and operating fleets. Furthermore, ports should establish management strategies for these factors to provide optimal equilibrium solutions for carriers' transportation networks.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.13 no.5
• /
• pp.1-6
• /
• 2009

A development of a composite solid propellant is carried out for an application to gas generators as an energy source of rocket system. With HTPB as a propellant binder which has 80% of particle loading ratio, a favorable rheology, and moderate curing properties at the range of $-50^{\circ}{\sim}70^{\circ}C$, AN is selected as the first kind of oxidizer having the characteristics of a low flame temperature, minimal particle residual as well as nontoxic products. AP is the second oxidant for ballistic property control. A series of experiments for the improvement of physical properties were conducted and resulted in the propellant formulation having 30% of strain rate at 8 bar of max. stress.

• Environmental and Resource Economics Review
• /
• v.15 no.5
• /
• pp.827-858
• /
• 2006

The paper presents game theoretic models for self-enforcing coalition formation in order to sustain effective international environmental agreements(IEAs). The model analyzes how the intrinsically strategic nature of a government's environmental policies(the emission allowance standard) calls for rules to sustain an IEA. Focusing on the recent theoretical developments in the infinitely repeated game, the paper introduces some mechanisms to show how self-interested sovereign countries are cooperatively able to maintain an IEA rather than defect to initially profit at the expense of a pollution heaven later on. For a more realistic case needed to sustain an IEA, an optimal international environmental policy with both signatories and non-signatories under imperfect monitoring is also explored. In this extension of the model, the derivation process for a critical discount factor, a trigger price level and the length of punishment period is briefly discussed.

• Journal of the Korean association of regional geographers
• /
• v.15 no.4
• /
• pp.464-477
• /
• 2009

This research analyzed reality of multicultural education of Korea and suggested policy implication through a questionnaire survey of teachers, students, and parents in elementary schools, Daegu City. Multicultural policies in Korea mainly helped a member of multicultural family who immigrated into Korea to learn Korean language and culture. Thus, the common people have a few chances to have multicultural education; however they mainly experienced multiculture indirectly through mass media. Therefore they had low level of understanding and satisfaction and their consciousness was narrow. Most of people completely come out in sympathy with that multicultural education should be taught at school. To overcome the current issues of multicultural education, its goals, contents and tasks should be clearly established. Multicultural education is taught from elementary school in holistic approach; however, methods of learning and teaching are different according to a curriculum.

• Journal of the Korean Society for information Management
• /
• v.23 no.2
• /
• pp.39-59
• /
• 2006

In this study we proposed a new informational structure and category labels to fully support the functions of school websites as an access tool to its contents. The proposed model was divided into three main aspects. First, main menu structure was the primary guideline to access information embedded in a website. Therefore, The proposed main menu structure consisted of 9 categories that are commonly provided by 17 existing school websites. Second, first-level categories consisted of total 35 categories under 9 main menu categories. Each category was placed under certain categories in main menu based on the relationships with the meaning of the upper level categories. Third, the proposed model adopted general and comprehensive terms as category labels. The terms used as category labels were based on the analysis of existing category labels, and the most frequently used terms were selected from the current school websites.

• Journal of the Korean Society for information Management
• /
• v.26 no.4
• /
• pp.35-58
• /
• 2009

One of the main goals of providing open access is to vitalize the exchange of academic information by allowing access to the scholarly research outputs for everyone without the legal, financial, and technical barriers. We regard the use of the institutional repository as an open access enabler. In this study, we tried to make the factors, which enable the successful deployment of the institutional repository, explicit. We utilized literature review and case studies to generate the potential success factors for the institutional repository deployment. We verified the factors by having in-depth interviews with the subject matter experts. The resulting factors were organized as organizational, political, and technical ones. The organizational factors included the strong open access support by the organization heads. Under the policy factors, a number of issues such as selection of the core contents, minimum quality control, protection of the copyrights, forming supporting groups through active advertising, long-term preservation, incentive, and mandate, were included. The technical factors included easy submission, support for interoperability, and support for the publication activities.

• The Journal of the Korea Contents Association
• /
• v.10 no.10
• /
• pp.479-493
• /
• 2010

Along with the transformation of the knowledge-based environment, e-learning has become a main teaching and learning method, prompting various research efforts to be conducted in this field. One major research area in e-learning involves adaptive learning systems that provide personalized learning content according to each learner's characteristics by taking into consideration a variety of learning circumstances. Active research on ontology-based adaptive learning systems has recently been conducted to provide more efficient and adaptive learning content. In this paper, we design and propose an adaptive learning system based on the concept lattice of Formal Concept Analysis (FCA) with the same objectives as those of ontology approaches. However, we are in pursuit of a system that is suitable for learning of specific domains and one that allows users to more freely and easily build their own adaptive learning systems. The proposed system automatically classifies the learning objects and concepts of an evolved domain in the structure of a concept lattice based on the relationships between the objects and concepts. In addition, the system adaptively constructs and presents the learning structure of the concept lattice according to each student's level of knowledge, learning style, learning preference and the learning state of each concept.

• The Korean Journal of Pesticide Science
• /
• v.4 no.2
• /
• pp.44-49
• /
• 2000

Objective of this study was to determine the Si distribution and extent of control of powdery mildew diseases of cucumber(Cucumis sativus L.). The distribution of silicon in the leaf epidermis of cucumber plants grown in hydroponic nutrient solutions supplemented with soluble silicates was examined using scanning electron microscopy and energy dispersive X-ray analysis. The silicate absorbed from nutrient solution was translocated into cucumber leaves, and accumulated mainly in the cells surrounding the base of trichome hairs. Base cells surrounding the trichomes also had high levels of Si, Ca, and K. Si levels in the epidermal cells for low Si treatment were not detectable except in the trichome bases. Hyphal lengths of powdery mildew occurring on cucumber leaves cultivated in medium with high concentration of silicate were remarkably shorter than those of cucumber leaves cultivated with low concentration of silicate. There was a negative correlation between hyphal length of S. fuliginea and silicate concentrations.

• Journal of KIISE:Computing Practices and Letters
• /
• v.14 no.9
• /
• pp.906-910
• /
• 2008

As the mobile environment becomes widely used, there is a growth on the concern about recognizing and sharing user context. Sharing context makes the interaction between human more plentiful as well as helps to keep a good social relationship. Recently, it has been applied to some messengers or mobile applications with sharing simple contexts, but it is still required to recognize and share more complex and diverse contexts. In this paper, we propose a context-aware messenger that collects various sensory information, recognizes representative user contexts such as emotion, stress, and activity by using dynamic Bayesian networks, and visualizes them. It includes a modular model that is effective to recognize various contexts and displays them in the form of icons. We have verified the proposed method with the scenario evaluation and usability test.

• KIISE Transactions on Computing Practices
• /
• v.22 no.11
• /
• pp.547-558
• /
• 2016

Construction of multi-site Cloud Infrastructure with OpenStack, the most popular cloud open source project with various ICT infrastructure technologies, has operational inefficiency due to installation complexity and geographical limitation. To address this inefficiency, we gradually developed automated installation/configuration tools to automate installation/configuration of Linux and OpenStack by complying with DevOps methodology over a multi-site OpenStack testbed called OF@KOREN SmartX Playground. However, the pre-developed installation tools can be used only for limited cases. Therefore, we designed and developed a prototype of SmartX Provisioning Framework which could conducts Playground-wide provisioning flexibly by following three steps of resource management in Software-defined Infrastructure. We verified the efficiency of the provisioning functionality of the framework by demonstrating an example of automated multi-site cloud construction.