• Journal of the Korea Society of Computer and Information
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• v.1 no.1
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• pp.53-64
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• 1996

The methods for designing the adaptive filter performing DSP(digital signal processing)functions In mobile communication systems are Least-squares algorithm. Fast-Kalman and adaptive lattice algorithm. Least-squares algorithm It fast convergence algorithm for signal Processor of adaptive equallizer and used for eliminating inter symbol Interference which occur inmultiple path fading channel In mobille communication systems. In this paper. we propose the method of control adjustably algebra characteristics of signal vector that is sampling at some of new data sequence and confirm the improvement of fast convergence and iterative performance speed compared to existing algorithms by computer simulation.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.13 no.11
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• pp.1089-1096
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• 2001

The cool-down performance after soaking is very important in an automotive air-conditioning system and is considered as the key design variable. Therefore, understanding of the overall transient characteristics of the system is essential to the preliminary design as well as steady-state characteristics. The objective of this study is to develop a computer simulation model and estimate theoretical1y the transient performance of an automotive air-conditioning system. To accomplish this, a mathematical modelling of each component, such as compressor, condenser, expansion valve, and evaporator, is presented first of all. For a detailed calculation, condenser and evaporator are divided into many subsections. Each sub-section is an elemental volume for modelling. In models of expansion valve and compressor, dynamic behaviors are not considered in an attempt to simplify the ana1ysis, but the quasi-static ones are just considered, such as the relation between mass flow rate and pressure drop in expansion device, polytropic process in compressor, etc. The developed simulation model is validated with a comparison to laboratory test data of an automotive air-conditioning system. The overall time-tracing properties of each component agreed fairly well wish those of test data in this case.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.6C
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• pp.571-580
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• 2002

In this paper, we relatively differentiate maximum delay for each Assured Service subclass in Differentiated Services by allocating bandwidth to each subclass differently. To maximize the throughput for the In-profile traffic and the link utilization, we propose a Cofiguration method of RIO and the admission control criterion based on the buffer size determined by the network topology and the ratio of bandwidth allocated to each subclass. Simulation results show that the proposed method can calculate the capacity to guarantee the QoS for the Assured Service and maximize the throughput for the In-profile traffic and the link utilization by applying the RIO parameter values set through the proposed configuration method.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.35 no.4
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• pp.316-322
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• 2007

The EHA(Electro-hydrostatic Actuator) reveals completely different characteristics from the conventional valve-controlled Electro-hydraulic actuators. In this paper, its mathematical model including nonlinear elements was derived to be verified by experiments. Based on this, a simulation program was developed for the EHAs consisting of an electric motor driven hydraulic pump, pipe lines and a cylinder. The influence of important design parameters such as peak motor torque and rotational inertia moment of the hydraulic pump on control performance was investigated, where the test condition was intentionally selected so that the motor torque was saturated during the transient phase. As a result, design requirements for improving the control accuracy under full speed operation conditions of the EHAs were investigated.

• 한국신재생에너지학회:학술대회논문집
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• 2006.06a
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• pp.567-570
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• 2006

A numerical study has been carried out for a solar water heater which consists of double skin solar vacuum tubes. Water is heated as it flows through the coaxial fluid conduit inserted in each tube. The space between the exterior of the fluid conduit and the glass tube is tilled with antifreeze solution. This is to facilitate heat transfer from the solar heated absorber surface to water and to prevent the functional problems due to freezing in frigid weather conditions. A one-dimensional steady state model is fully described which will be used to develop three-dimensional model using STAR-CD. These models could be used efficiently in designing double skin solar collector tubes with different geometrical parameters other than those considered in the present analysis. Results show a good agreement when compared with other experimental data demonstrating the reliability of the one-dimensional model employed.

• Journal of the Society of Naval Architects of Korea
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• v.43 no.1 s.145
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• pp.103-118
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• 2006

At the initial design stage, the generation process of the production material information of a building block and the simulation process of the block erection, which are required to perform the production planning and scheduling, have been manually performed using 2D drawings, based on the data of parent ships, and subjective intuition from past experience. To make these processes automatic, the accurate generation method of the production material information and the convenient simulation method of the block erection based on the initial hull structural model(3D CAD model), were developed in this study. Here, the initial hull' structural model was generated from the initial hull structural CAD system early developed by us. To evaluate the developed methods. these methods were applied to corresponding processes of a deadweight 300,OOOton VLCC. As a result. it was shown that the production material information of a building block can be accurately generated and the block erection can be conveniently simulated in the initial design stage.

• Proceedings of the Korea Information Processing Society Conference
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• 2013.11a
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• pp.1298-1301
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• 2013

대화 시스템에서 올바른 대화를 진행하기 위해서는 화자의 대화 의도를 파악하는 것이 중요하다. 특히 영어를 교육하기 위한 영어 교육용 대화 시스템에서는 학습자의 대화 의도 파악 오류가 발생할 경우 영어 교육에 문제가 발생하기 때문에 학습자의 대화 의도를 더욱 정확하게 분석 및 파악하는 것이 중요하다. 대화 패턴이란 시스템 발화에 대응되는 사용자 발화의 규칙적인 연쇄라고 할 수 있다. 대화 패턴 기반 대화 의도 부착 방법은 1) 대화 코퍼스 구축 2) 대화 시나리오에 있는 발화를 대상으로 기본 명사구 청킹(Base NP Chunking)을 하고 중심어(Head Word), 토픽 추적(Topic Tracking)에 의한 대화 패턴을 자동으로 추출한 후, 3) 대화 패턴 수동 검수이다. 대화 패턴 기반 대화 의도 부착 방법은 기본 명사구에 대한 지식만 가지고 있으면 대량으로 구축할 수 있다는 장점이 있다. 99 개의 대화 시나리오를 학습코퍼스로 하고 1 개의 대화 시나리오에 대해 대화턴 성공률을 시물레이션 한 결과 63.64%가 나왔다.

• Journal of the Korea Computer Graphics Society
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• v.15 no.1
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• pp.1-6
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• 2009

This paper presents a new CIP method for unstructured mesh to reduce the numerical dissipation. To reflect precise physical characteristics, CIP method updates both the physical quantity and the derivative information. The proposed method uses the Finite Volume Method(FVM) to solve the non-advection term of CIP equation. And we performed several experiments to improve the accuracy of third-order interpolation. Our result shows that our algorithm has less numerical dissipation than that of linear advection solver.

• Transactions of the Korean Society of Automotive Engineers
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• v.10 no.4
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• pp.51-59
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• 2002

In this study, cycle simulation was performed to investigate the effect of EGR on combustion characteristics and emissions including NO and soot using a two-zone model in a DI diesel engine. The NO formation was well predicted for different EGR rate and temperature using a two-zone model. The oxygen in the inlet charge was replaced by CO$_2$ and H$_2$O with EGR. The reduction in the inlet charge oxygen resulted in very large reduction in NO level at the same inlet charge temperature. The effect of EGR was to reduce the burned gas temperature. When EGR was increased from 0% to 15%, the peak flame temperature was decreased by 50$\^{C}$ and it caused about 57% NO reduction. EGR caused increase of the overall inlet charge temperature which offset some of benefit of lower flame temperature resulting from O$_2$ displacement. Cooling the EGR was confirmed to provide additional benefits by lowering NO emission. It also reduced soot emission.

• The Transactions of the Korea Information Processing Society
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• v.4 no.5
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• pp.1289-1296
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• 1997

To build up a knowledge-based system in an Artifical Inerligence System, selecting an appropriate set of rules is one of the key provlems. In this paper, we discuss a new method for exteacting fuzzy rules diredtly from fuzzy membdrchip function dat for pattern classifcation. The fuzzy rules with variable fuzzy recions are defined by sharing fuzzy space in fuzzy grid.Tehse rules are extracted form memberchop function. Them, optimal input vari-ables for the rules are determined using the number of extracted rules as a criterion. The method is compared with neural networks using Ishibuchi. Finally, in order to demonstrate the cffectiveness of the present method, simulation results are shown.