• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 춘계학술대회 논문집
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• pp.395-398
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• 2002

This study is to examine the safety by analizing the hardness of bed and the characteristic of vibration to improve basic efficiency of machine-tool of drill-cell which is a high line center. The mistake of existing design was shown through the analysis of 3-D and structure. The purpose of this paper is to draw up a plan to improve performance and to propose the design method through finding out the optimum by analyzing dynamic property of structure in a quantity-way by CAE for a quantity-analogy of dynamic property in design steps.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2002년도 봄 학술발표회 논문집
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• pp.575-580
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• 2002

The most recent, like any other field we have requested that the concrete would increase more a performance. So, in this research we are intended to study on the property of Photocatalytic Concrete which is one of the High Performance Concrete. The fundamental phenomena of the Photocatalytic Concrete were observed by the NOx Analyzer, Bonding strength, SEM, Flow and Surface hardness(Pencil tester). As a result of this study, the Photocatalytic Concrete used Photocatalytic powder, admixture and other materials can obtain its properties, also photocatalytic efficiency(NOx reduction). Also, we have convinced of the Photocatalytic Concrete possibility and put on a spurt to improve its properties added a various experiment.

• Transactions on Electrical and Electronic Materials
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• 제15권4호
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• pp.217-220
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• 2014

We studied the plating properties of Sn-Pb solder according to the shape of the Cu wire's cross-section for photovoltaic ribbon. The thickness of the Sn-Pb layer largely decreased to 29% on a curved Cu surface, compared to a flat Cu surface. This phenomenon is caused by the geometrical decrease in the contact angle of the liquid Sn-Pb solder and an increase in the surface energy of the solid/vapor on the curved Cu surface. We suggest a new ribbon's design where the Cu wire's cross-section is a semi-ellipse. These semi-ellipse ribbons can decrease the use of Sn-Pb solder to 64% and increase the photovoltaic efficiency, by reducing the contact area between the ribbon and cell, to 84%. We also see an improvement of reflectivity in the curved surface.

• 한국경영과학회지
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• 제23권2호
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• pp.201-217
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• 1998

This paper attempts to show how DEA(data envelopment analysis), a nonparametric productivity analysis method, can be employed for insurance companies to improve their respective efficiencies and competitiveness. Specifically, we measured relative technical efficiencies and returns to scale of 11 Korean property-liability insurance companies using BCC model, and raised several issues including the cause of inefficiency, benchmarking toward reference set and resource allocation concerning the insurance companies. Also, in order to monitor the variability of the research results over periods, we employed longitudinal analysis to see the moving patterns of technical efficiencies, returns to scale and frequencies included in the reference set of the individual insurance companies under consideration. The methodology and the results in this paper may also serve as a useful guideline for individual insurance companies to set their respective business strategies.

• Journal of Power Electronics
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• 제13권5호
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• pp.814-828
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• 2013

The LCL resonant inductive power transfer (IPT) system is increasingly used because of its harmonic filtering capabilities, high efficiency at light load, and unity power factor feature. However, the modeling and controller design of this system become extremely difficult because of parameter uncertainty, high-order property, and switching nonlinear property. This paper proposes a frequency and load uncertainty modeling method for the LCL resonant IPT system. By using the linear fractional transformation method, we detach the uncertain part from the system model. A robust control structure with weighting functions is introduced, and a control method using structured singular values is used to enhance the system performance of perturbation rejection and reference tracking. Analysis of the controller performance is provided. The simulation and experimental results verify the robust control method and analysis results. The control method not only guarantees system stability but also improves performance under perturbation.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1989년도 한국자동제어학술회의논문집; Seoul, Korea; 27-28 Oct. 1989
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• pp.653-662
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• 1989

Cerebellar Model Arithmetic Controller (CMAC) has been introduced as an adaptive control function generator. CMAC computes control functions referring to a distributed memory table storing functional values rather than by solving equations analytically or numerically. CMAC has a unique mapping structure as a coarse coding and supervisory delta-rule learning property. In this paper, learning aspects and a convergence of the CMAC were investigated. The efficient training algorithms were developed to overcome the limitations caused by the conventional maximum error correction training and to eliminate the accumulated learning error caused by a sequential node training. A nonlinear function generator and a motion generator for a two d.o.f. manipulator were simulated. The efficiency of the various learning algorithms was demonstrated through the cpu time used and the convergence of the rms and maximum errors accumulated during a learning process. A generalization property and a learning effect due to the various gains were simulated. A uniform quantizing method was applied to cope with various ranges of input variables efficiently.

• 한국소음진동공학회논문집
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• 제18권5호
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• pp.516-523
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• 2008

Centrifugal turbo blower is requested highly efficiency and low noise in FCEV, but the noise generated by this machine causes of the most serious problems in the NVH performance. In general, centrifugal turbo blower is dominated by mechanical noise and aerodynamic noise. Mechanical noise is generated by rotation of the bearing, misalignment and unbalance. And aerodynamic noise is generated by the strong intersection between the flow discharged from the impeller and the cut-off in the casing. The first object of this study is to comprehend a noise property of the blower through the noise test. And, second object is to bring up the method that can reduce blower noise.

• 한국의류학회지
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• 제24권1호
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• pp.15-23
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• 2000

Effect of fixation methods on the flame retardant(FR) and performance properties of MDPPA/HMM treated cotton fabrics were studied. Combination of three different fixation methods - premercerization, swelling agent treatment, pad dry cure fixation, and wet fixation - were applied to flame retardant finish of cotton with MDPPA/HMM. As a result, an increase in internal volume of cotton fiber by pre-mercerization and addition of swelling agent, and wet fixation increased %add-on of FR agent improving FR efficiency and wash fastness. Tensile strength of MDPPA/HMM treated cotton fabrics by wet fixation and swelling agent were slightly decreased, but that of premercerized cotton was improved. Wet fixated fabric showed lower bending rigidity and better compressional properties which improved fabric hand. Retention of swelling ability of cotton treated with MDPPA/HMM improved moisture absorption properties.

• 디지털산업정보학회논문지
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• 제6권4호
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• pp.11-20
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• 2010

Ontology is important role in semantic web to construct and query semantic data. Because of dynamic characteristic of ontology, P2P environment is considered for ontology processing in web environment. For efficient processing of ontology in P2P environment, clustering of peers should be considered. When new peer is added to the network, cluster allocation problem of the new peer is important for system efficiency. For clustering of peers with similar chateristics, similarlity measure method of ontology in added peer with ontologies in other clusters is needed. In this paper, we propose similarity measure techniques of ontologies for clustering of peers. Similarity measure method in this paper considered ontology's strucural characteristics like schema, class, property. Results of experiments show that ontologies of similar topics, class, property can be allocated to the same cluster.

• 대한안전경영과학회지
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• 제15권2호
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• pp.103-111
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• 2013

Disaster management is successful if the situation in the event of an accident to minimize casualties and property damage, and commitment to improve the efficiency of personnel and material, and further the administration site conditions promptly reported to the director or the people. transmit from one generation to the next the stability of the society could seek would be. In this respect.