• Journal of the Institute of Electronics Engineers of Korea CI
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• v.45 no.5
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• pp.95-101
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• 2008

Modeling of stock prices forecast has been considered as one of the most difficult problem to develop accurately since stock prices are highly correlated with various environmental conditions including economics and political situation. In this paper, we propose a agent system approach to predict Korea Composite Stock Price Index (KOSPI) using neural network and statistical methods. To minimize mean of prediction error and variation of prediction error, agent system includes sub-agent modules for feature extraction, variables selection, forecast engine selection, and forecasting results analysis. As a first step to develop agent system for KOSPI forecasting, twelve economic indices are selected from twenty two basic standard economic indices using principal component analysis. From selected twelve economic indices, prediction model input variables are chosen again using best-subsets regression method. Two different types data are tested for KOSPI forecasting and the Prediction results showed 11.92 points of root mean squared error for consecutive thirty days of prediction. Also, it is shown that proposed agent system approach for KOSPI forecast is effective since required types and numbers of prediction variables are time-varying, so adaptable selection of modeling inputs and prediction engine are essential for reliable and accurate forecast model.

• Journal of Korea Multimedia Society
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• v.23 no.10
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• pp.1296-1306
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• 2020

Childhood verbal communication impacts children's language skills and has a positive effect as partners use more vocabulary. But reduction in family time, caused by lowered age for private education and so on, has reduced the chance for children to speak with partners who have a proficient language skill. This vacancy was naturally occupied by the media, which has become one of the cornerstones of the growth of kids' contents. Kids contents are making various attempts to expand the breadth of services. But most contents still focus on unilateral visual information delivery yet, so there is a limit to satisfy the vacancy of conversation partners. Therefore this paper suggests an ECA(Embodied conversational agent) to induce children's spoken conversation using a virtual character frequently used in kids contents. This system is implemented by the voice bot and agent model produced using an IBM assistant and Unity. As a result of using ECA for 66 children of 5-9 years old, it showed meaningful results in terms of induction of verbal communication.

• The KIPS Transactions:PartD
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• v.9D no.5
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• pp.955-962
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• 2002

Commercial internet auction systems have been successfully used recently. In those systems, because reserve prices of auction items are given by sellers only, the success bid rate can be decreased due to the large difference between the reserve price and the normal price. In this paper, we propose an agent that generates reserve prices to sellers based on past auction data and item prices gathered from the web. Through performance experiments, we show that the successful bid rate increases by preventing sellers from making unreasonable reserve prices. Using the pricing agent, we design and implement an XML-based auction system on the web.

• Korean Journal of Computational Design and Engineering
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• v.4 no.3
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• pp.210-223
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• 1999

An efficient management of product information is critical to the enhancement of corporate competitiveness. Product information is often distributed in term of organization, geography, and time. With the rapid increase in the use of Internet or its associated Web and intranets, it has been accelerating to integrate the distributed information. In this research, a Distributed, Open, Intelligent Product data Management system, namely DOI-PDM, is developed. This system deals with product information following the STEP standard, and its operation is controlled by a Web-based workflow management system. CORBA is employed to ensure interoperability among distributed objects. It is intended to achieve openness by using various standards, such s STEP, KQML, SGML, and WfMC specifications. One major difficulty in managing it needs also be properly modified according to the dynamics. It however is very hard to have a prior anticipation to the dynamics. It however is very hard to have a prior anticipation to the modification requirements in practice. We introduce a process adaptation model and a use of intelligent agent technology. An agent is delegated to modify process definitions during run-time. A method of agent implementation and a proper communication scheme among te agents are proposed. Also developed in this research is a STEP-based content search system which can co-work with the agents by providing relevant product information that the agents require.

• The KIPS Transactions:PartB
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• v.9B no.5
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• pp.517-522
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• 2002

Mobile agent systems offer a new paradigm for distributed computation and a one of solution for limitation of existent Client-server model. Mobile agent systems provide interface that can migrate from host to host in a heterogenous network. For secure execution, it must solve security problem of mobile code before. In this paper, we are propose the protocol that applied signature technique and hash chain technique. This protocol enable one to offer forward integrity, non-repudiation, and forgery detection, when mobile agents are perform the task by migrating a network.

• Journal of the Korean Institute of Intelligent Systems
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• v.18 no.3
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• pp.347-353
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• 2008

The realization of intelligence by using ontology is getting attention recently. However, it is necessary to design ontology models suitable to their purpose in order to use efficiently the intelligence realized by ontology. In this paper, we define a cognition cycle for intelligent agents representing a process that the intelligent agents recognize an event and react to it. Moreover, we design an ontology-based intelligent agent, and propose an ontology model that is possible to change the agent's states, to express its emotions, and to expand its intelligence through ontological inference. Finally, we develop an intelligent agent named Helen, confirm the change of her inner states according to the environment and situation, and show the easiness of the extension of her intelligence.

• 한국정보컨버전스학회:학술대회논문집
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• 2008.06a
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• pp.53-56
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• 2008

This paper reports on the ACQA(Animated agent for Conversational Question Answering) project conducted at LIMSI. The aim is to design an expressive animated conversational agent(ACA) for conducting research along two main lines: 1/ perceptual experiments(eg perception of expressivity and 3D movements in both audio and visual channels): 2/ design of human-computer interfaces requiring head models at different resolutions and the integration of the talking head in virtual scenes. The target application of this expressive ACA is a real-time question and answer speech based system developed at LIMSI(RITEL). The architecture of the system is based on distributed modules exchanging messages through a network protocol. The main components of the system are: RITEL a question and answer system searching raw text, which is able to produce a text(the answer) and attitudinal information; this attitudinal information is then processed for delivering expressive tags; the text is converted into phoneme, viseme, and prosodic descriptions. Audio speech is generated by the LIMSI selection-concatenation text-to-speech engine. Visual speech is using MPEG4 keypoint-based animation, and is rendered in real-time by Virtual Choreographer (VirChor), a GPU-based 3D engine. Finally, visual and audio speech is played in a 3D audio and visual scene. The project also puts a lot of effort for realistic visual and audio 3D rendering. A new model of phoneme-dependant human radiation patterns is included in the speech synthesis system, so that the ACA can move in the virtual scene with realistic 3D visual and audio rendering.

• 한국HCI학회:학술대회논문집
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• 2006.02a
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• pp.918-925
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• 2006

Recent development of teachable agent provides learners with active roles as knowledge constructors and focuses on the individualization. The aim of this adaptive agent is not only to maximize the learner's cognitive functions but also to enhance the interests and motivation to learn. In order to establish the relationships among user characteristics and response patterns and to extract the algorithm among variables, we measured the individual characteristics and analyzed logs of the teachable agent named KORI (KORea university Intelligent agent) through the student modeling. A correlation analysis was conducted to identify the relationships among individual characteristics, user responses, and learning outcomes. Among hundreds of possible relationships between numerous variables in three dimensions, nine key user responses were extracted, which were highly correlated with either individual characteristics and learning outcomes. The results suggest that certain type of learner responses or the combination of the responses would be useful indices to predict the learners' individual characteristics and ongoing learning outcome. This study proposed a new type of dynamic assessment for individual differences and ongoing cognitive/motivational learning outcomes through the computation of responses without measuring them directly. The construction of individualized student model based on the ongoing response pattern of the user that are highly correlated with the individual differences and learning outcome may be the useful methodology to understand the learner's dynamic change during learning.

• Journal of the Korea Convergence Society
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• v.7 no.4
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• pp.25-32
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• 2016

When using reliable multicast protocol over air links, the multicast packets lost in the air link cause the initiation of retransmission request packets and the implosion of retransmission packets, which deteriorate multicast session performance. This paper proposes on the efficient reliable multicast mechanism in wireless networks utilizing the Agents. In this paper we show the design of a retransmission agent which improves the performance of reliable multicast sessions in wireless network. The main idea is to cache reliable multicast packets at the base station and perform local retransmissions across the wireless link. MATLAB has been used to simulate and to get performance results for signaling overhead and processing delay through the comparison of the proposed agent model to the Multicast File Transfer Protocol. It has been proven from the simulation results that the proxy module make pass trials shorter in Multicast File Transfer Protocol.

• Proceedings of the Korea Inteligent Information System Society Conference
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• 2001.01a
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• pp.37-44
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• 2001

This paper describes the modeling of work environment for the extraction of abstract operation rules for cooperative work with multiple agent. We propose the modeling method using a potential field. In the method, it is applied to a box pushing problem, which is to move a box from a start to a goal b multiple agent. The agents follow the potential value when they move and work in the work environment. The work environment is represented as the grid space. The potential field is generated by Genetic Algorithm(GA) for each agent. GA explores the positions of a potential peak value in the grid space, and then the potential value stretching in the grid space is spread by a potential diffusion function in each grid. However it is difficult to explore suitable setting using hand coding of the position of peak potential value. Thus, we use an evlolutionary computation way because it is possible to explore the large search space. So we make experiments the environment modeling using the proposed method and verify the performance of the exploration by GA. And we classify some types from acquired the environment model and extract the abstract operation rule, As results, we find out some types of the environment models and operation rules by the observation, and the performance of GA exploration is almost same as the hand coding set because these are nearly same performance on the evaluation of the consumption of agent's energy and the work step from point to the goal point.