• Journal of KIISE:Computing Practices and Letters
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• v.10 no.1
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• pp.89-98
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• 2004

Conversational agent is a system that provides users with proper information and maintains the context of dialogue on the natural language. Analyzing and modeling process of user's query is essential to make it more realistic, for which Bayesian network is a promising technique. When experts design the network for a domain, the network is usually very complicated and is hard to be understood. The separation of variables in the domain reduces the size of networks and makes it easy to design the conversational agent. Composing Bayesian network as two stages, we aim to design conversational agent easily and analyze user's query in detail. Also, previous information of dialogue makes it possible to maintain the context of conversation. Actually implementing it for a guide of web pages, we can confirm the usefulness of the proposed architecture for conversational agent.

• Proceedings of the Korean Institute of Interior Design Conference
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• 2006.05a
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• pp.264-267
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• 2006

The purpose of this study is to examine the advertisements of eco-friendly interior products and finishing materials in 3 interior design magazines which have been published for 4 years since 2002: to identify specific types of the products and materials that consumers can choose and to analyze their special ingredients which have functions and effectiveness related to health. Literature review and content analysis on the advertisements were employed. The results are as follows: The amount of advertisements has been continuously increasing due to the public concerns on well-being and finishing material types absolutely took the greatest proportion (92.8%) among them. Floor coverings, wall papers, and paints are the big 3 materials in the finishing material advertisements. The frequently mentioned health-related ingredients in them were charcoal, natural jade, nanosilver, yellow soil and quartz porphyry, And their main functions were emission of negative ions and ultra infrared. However, it's not easy to find their scientific test results on health. Objective guidelines are needed for the right selection of interior products and materials to maintain healthy interior environment.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.19 no.5
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• pp.667-671
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• 2010

The study was aimed at developing a power transmission coupling that is possible to transfer power without any trouble even if the two rotating shafts are making minute misalignment. The coupling that has been developed is Flange Flexible Urethane-key Coupling that connects two shafts by flanges with Urethane-key. A model coupling for use in transmitting power of 10hp was made and undergone performance evaluation and tests. Property and usefulness was proved through the test. The performance evaluation has demonstrated a property of $11.25Kgf{\cdot}m$ of allowable torque and 28.25hp of power at 1,80Orpm, which was found to be superior compared to the performance of similar couplings. Based on the performance test, study was made also for improving the shape of the Urethane-key and was successful to make the flange in smaller outside diameter. Further application test at site has proved that the product is easy to install and maintain, and has property of absorbing minute misalignment between two shafts and vibration caused there from.

• Transactions of the Korean Society of Automotive Engineers
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• v.10 no.4
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• pp.175-180
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• 2002

In order to satisfy the requirements of time reduction and cost saving for development of electronic control systems(ECU) in automotive industry, the applications of a standardized real-time operating system(RTOS) and a communication protocol to ECUs are increased. In this study, a body control module(BCM) that employs OSEK/VDX(open system and corresponding interfaces for automotive electronics/vehicle distributed executive) OS tour the RTOS and a controller area network(CAN) fur the communication protocol is designed, and the performances of the system are evaluated. The BCM controls doors, mirrors, and windows of the vehicle through the in-vehicle network. To identify all the transmitted and received control messages, a PC connected with the CAN communication protocol behaves as a CAN bus emulator. The control system based upon in-vehicle network improves the system stability and reduces the number of wiring harness. Furthermore it is easy to maintain and simple to add new features because the system is designed based on the standards of RTOS and communication protocol.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.60 no.2
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• pp.76-81
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• 2011

Power system frequency is the main index of power quality indicating an abnormal state and disturbances of systems. The nominal frequency is deviated by sudden change in generation and load or faults. Power system is used as frequency relay to detection for off-nominal frequency operation and connecting a generator to an electrical system, and V/F relay to detection for an over-excitation condition. Under these circumstances, power system should maintain the nominal frequency. And frequency and frequency deviation should accurately measure and quickly estimate by frequency measurement device. The well-known classical method, frequency estimation technique based on the DFT, could be produce the gain error in accuracy. To meet the requirements for high accuracy, recently Wavelet transforms and analysis are receiving new attention. The Wavelet analysis is possible to calculate the time-frequency analysis which is easy to obtain frequency information of signals. However, it is difficult to apply in real-time implementation because of heavy computation burdens. Nowadays, the computational methods using the Wavelet function and transformation techniques have been searched on these fields. In this paper, we apply the Recursive Discrete Wavelet Transform (RDWT) for the frequency estimation. In order to evaluate performance of the proposed technique, the user-defined arbitrary waveforms are used.

• Transactions of the Korean Society of Automotive Engineers
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• v.16 no.2
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• pp.106-113
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• 2008

The goal of crashworthiness is an optimized vehicle structure that can absorb the crash energy by controlled vehicle deformations while maintaining adequate space so that the residual crash energy can be managed by the restraint systems to minimize crash loads transfer to the vehicle occupants. Front side assembly is one of the most important energy absorbing components in relating to the crashworthiness design of vehicle. The structure and shape of the front side assemblies are different depending on auto-makers and size of vehicles. Thus, it is not easy to grab an insight on designer's intention when you glance at a new front side member without experiences. In this paper, we have performed the explicit nonlinear dynamic finite element analysis on the front side assembly of a passenger car to investigate the effect of thickness distribution of the front side assembly on the collapse shape, which is important in the aspect of controlling deformation to maintain adequate space, from the viewpoint of reverse engineering. To do this, we have performed crash FE analysis for the assembly by varying the thickness distribution of the assembly.

• Journal of Satellite, Information and Communications
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• v.9 no.1
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• pp.65-69
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• 2014

The Communication, Ocean and Meteorological Satellite(COMS) data processing system(CMDPS) has developed to support the meteorological observation and weather prediction by NMSC(National Meteorological Satellite Center) and it is generating the 16 kind of meteorological data(Level 2 product). Unfortunately, currently CMDPS has some problems in terms of the system maintenance and the integrated software efficiency, and the extension to support the next generation meteorological satellite data processing. To solve this problems, in this paper, we suggest the extensible component-based system architecture for COMS meteorological data processing with consideration of identified issues. Proposed system is adapted the component-based frameworks with extensible architecture. We expects that this system will be provide easy ways to develop new satellite data processing algorithms and to maintain the system.

• Ocean and Polar Research
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• v.26 no.1
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• pp.102-111
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• 2004

Recirculating aquaculture system (RAS) consists of different treatment compartments that maintain water quality within the ranges commonly recommended for fish cultures. However, common RASs still exert considerable environmental impact since concentrations of organic matter and nutrients in their effluents are high. Compared with the traditional RAS, the model RAS developed here use a sedimentation basin for digestion purposes and then use the released volatile organic matter to stimulate a denitrification process. Different treatment compartments for solids, total ammonia nitrogen, and nitrate removal have been reviewed. This paper provides the basic information on designing different treatment compartments as well as the engineering criteria in closed seawater RAS, consisting of circular tanks for fish cultures; dual drain systems, sedimentation basins and foam fractionators for removal of solids; nitrification biofilters for TAN removal; denitrification biofilters for nitrate removal; and aerators for aeration. The main purpose is to outline a common procedure in designing of closed RAS for marine fish culture with an emphasis on easy management and low expense, as well as reduction of the environmental impact.

• Journal of Korea Multimedia Society
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• v.14 no.12
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• pp.1572-1582
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• 2011

The rapid growth of UnderWater Acoustic Sensor Networks (UW-ASNs) has led researchers to enhance underwater MAC protocols against limitations existing in underwater environment. We propose the customized robust real-time packet inspection mechanism with addressing the problem of the search for the data packet loss and network performance quality analysis in UW-ASNs, and describe our experiences using this approach. The goal of this work is to provide a framework to assess the network real-time performance quality. We propose a customized and adaptive mechanism to detect, monitor and analyze the data packets according to the MAC protocol standards in UW-ASNs. The packet analyzing method and software we propose is easy to implement, maintain, update and enhance. We take input stream as real data packets from sniffer node in capture mode and perform fully analysis. We were interested in developing software and hardware designed tool with the same capabilities which almost all terrestrial network packet sniffers have. Experimental results confirm that the best way to achieve maximum performance requires the most adaptive algorithm. In this paper, we present and offer the proposed packet analyzer, which can be effectively used for implementing underwater MAC protocols.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.5 no.7
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• pp.1314-1320
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• 2001

DC motors have widely been used in the field of variable-speed driving system since it is easy to control flux and torque of the motors precisely but it is hard to check and maintain those periodically. In addition, there are difficulties in high power and high speed running due to rectifying limit of commutator, and are a lot of restrictions in installation. Therefore, speed control in BLDC(Brushless DC) motors have seriously been studied for a long while. In this paper, a mathematical model of BLDC motor driven by PWM inverter is developed. Dynamics and steady-state characteristics of BLDC motor are simulated and analyzed with a series of experiments for the parameter estimation : torque, speed, phase voltage and current.