• The Journal of the Korea Contents Association
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• v.4 no.4
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• pp.197-203
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• 2004

In mobile network, the maintenance o( host grouping or the multicast delivery tree for multicasting algorithm becomes a major issues. In this paper, we explore the issues of mobile Multicast scheme using Mobile-IPv6, and addresses case when a mobile host is a source as well as a recipient of a given multicast operation using MLD(Multicast Listener Discovery) scheme, and the proposed MLD-based multicasting protocol asks its HA(Home Agent) to stop forwarding multicast for group using tunneling. We examine and compare our model to existing approaches by proposed cost model, and observe an improved ferformacne.

• Proceedings of the Korea Contents Association Conference
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• 2003.05a
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• pp.227-230
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• 2003

A system connected in Internet can be intruded by cracker via several systems. This paper proposes an efficient traceback model in order to trace a route of crackers. The traceback system is composed of a traceback server model and a traceback client model, As transmitting intrusion information from an area where client agent is installed to traceback server, the system distinguishes which systems are used as intrusion route. The traceback system can retrace intrusion route efficiently in an area where a traceback client is installed.

• International Journal of Quality Innovation
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• v.8 no.2
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• pp.20-31
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• 2007

Moral hazard and adverse selection often exist in asymmetric information environment. In this paper, quality investment decision problem is studied under moral hazard. A basic model for quality investment level decision is developed with the supplier as a principal and the buyer as an agent. And then we regard the supplier and the buyer's rational limitations to set up a model when the buyer's quality evaluation and processing activities are hidden. The model is optimized and the results under different backgrounds are discussed and compared. Results show that the buyer's quality evaluation level and processing level are mostly influenced by the supplier's quality assurance payment. Both the supplier and the buyer choose different quality investment levels under moral hazard because of the supplier's payment to the buyer in case of internal failure and external failure.

• KDI Journal of Economic Policy
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• v.37 no.3
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• pp.1-30
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• 2015

Based on a quantitative, heterogeneous agent general equilibrium model, we compute the optimal tax rates for labor and capital incomes for the Korean economy. According to our model, a more progressive income tax schedule along with a higher capital tax rate can increase average welfare by as much as 0.86% of permanent consumption. Approximately 64% of house-holds, those with low assets and low productivity, are better off when a more progressive optimal tax schedule is adopted. Despite the potentially significant welfare gains, our calculation should be interpreted with caution because our benchmark model does not take into account possible capital outflows or the increased administrative costs associated with high taxes.

• Asia pacific journal of information systems
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• v.12 no.1
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• pp.1-16
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• 2002

Most of searching systems used by shopping-mall provide too much information for user requirements or fail to provide appropriate items reflecting customer's preference. This paper aims to design and implement the product searching systems based on customer preference which will enable efficient product selection in the internet shopping-mall. The proposed system consists of user/provider interface, searching and model agent, data management system, and model management system. Especially, we construct the searching pattern database to support fast search using association mining method. And this system includes the customer-oriented decision model which shows the highly preferred products. Input weight value per attribute and preference level should be needed to compute priority grade of preference.

• Journal of Institute of Control, Robotics and Systems
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• v.16 no.11
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• pp.1038-1043
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• 2010

In this paper, an adaptive sliding-mode formation control and collision avoidance are proposed for electrically driven nonholonomic mobile robots with model uncertainties and external disturbances. A sliding surface based on the leader-follower approach is developed to achieve the desired formation in the presence of model uncertainties and disturbances. Moreover, by using the collision avoidance function, the mobile robots can avoid the obstacles successfully. Finally, simulations illustrate the effectiveness of the proposed control system.

• Proceedings of the IEEK Conference
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• 1999.06a
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• pp.1029-1032
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• 1999

Muscle based face image synthesis is one of the most realistic approach to realize life-like agent in computer. Facial muscle model is composed of facial tissue elements and muscles. In this model, forces are calculated effecting facial tissue element by contraction of each muscle strength, so the combination of each muscle parameter decide a specific facial expression. Now each muscle parameter is decided on trial and error procedure comparing the sample photograph and generated image using our Muscle-Editor to generate a specific face image. In this paper, we propose the strategy of automatic estimation of facial muscle parameters from 2D marker movement using neural network. This also 3D motion estimation from 2D point or flow information in captered image under restriction of physics based face model.

• Journal of the Korea Society for Simulation
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• v.9 no.1
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• pp.55-66
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• 2000

This paper deals with complex system theory to describe land combat situation using EINSTein (Enhanced ISAAC Neural Simulation Tool) simulation model. Many studies have shown that existing Lanchester equations used in most wargame models does not describe changes of combat units, real land warfare situation and qualitative factors in combat. Future warfare will be a non-linear combat with various weapon system and complex combat units. EINSTein models is an agent-based simulation tool using complex system theory. We have compared and tested land combat results with Lanchester models and EINSTein models. The results have shown that EINSTein model has a possibility to apply and analyze land warfare more properly than Lanchester models.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.3 no.2
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• pp.215-221
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• 2003

Generally, we want to be searched the newest as well as some appropriate personalized information from the internet resources. However, it is a complex and repeated procedure to search some appropriate information. Moreover, because the user's interests are changed as time goes, the real time modeling of a user's interests should be necessary. In this paper, I propose PREA system that can search and filter documents that users are interested from the World Wide Web. And then it constructs the user's interest model by a modified spreading neural network. Based on this network, PREA can easily produce some queries to search web documents, and it ranks them. The conventional spreading neural network does not have a visualization function, so that the users could not know how to be configured his or her interest model by the network. To solve this problem, PREA gives a visualization function being shown how to be made his interest user model to many users.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.4 no.4
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• pp.547-559
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• 2010

As web-based online communities are rapidly growing, the agents in the communities need to know their measurable belief of trust for safe and successful interactions. In this paper, we propose a computational model of trust resulting from available feedbacks in online communities. The notion of trust can be defined as an aggregation of consensus given a set of past interactions. The average trust of an agent further represents the center of gravity of the distribution of its trustworthiness and untrustworthiness. Furthermore, we precisely describe the relationships among reputation, trust and average trust through concrete examples showing their computations. We apply our trust model to online social networks in order to show how trust mechanisms are involved in the rational purchasing decision-making of buyers and sellers, and we summarize our simulation results.