• Journal of the Korean Ceramic Society
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• v.31 no.11
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• pp.1283-1292
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• 1994

Ultra-fine $\beta$-SiC powders were fabricated by self-propagating high temperature synthesis process (SHS) using chemical furnace. The dependences of the C powders with different surface areas, the molar ratios of C/Si, the weight ratios of chemical fuel content, and pellet diameter-size on synthesis were investigated. Compositional and structural characterization of these powders was carried out by scanning electron micrograph and X-ray diffraction. The $\beta$-SiC powders which had C/Si mole ratio=1.05, 3 times chemical fuel contents, and pellet diameter=20 mm were optimum for synthesis efficiency. By optimizing process-variables, it is possible to fabricate $\beta$-SiC powders which have little secondary phases ($\alpha$-SiC).

• The Korean Journal of Ceramics
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• v.4 no.1
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• pp.5-8
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• 1998

Flat belt(FB) type high pressure apparatus has been succesfully utilized in various high pressure experimental stations in Korea and Japan to conduct HPHT (high pressure and high temperature) diamond synthesis. Present paper discusses pressure calibration of FB apparatus at high temperature to establish P-T condition of diamond synthesis. We also present some examples of controling P-T condition through careful experimental set-up of the high pressure sample cells. Finally we discuss reproducibility of pressure and temperature condition of the HPHT diamond synthesis.

• Speech Sciences
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• v.12 no.1
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• pp.55-63
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• 2005

This paper introduces a 'Hanmal' Korean language diphone database for speech synthesis, which has been publicly available since 1999 in the MBROLA web site and never been properly published in a journal. The diphone database is compatible with the MBROLA programme of high-quality multilingual speech synthesis systems. The usefulness of the diphone database is introduced in the paper. The paper also describes the phonetic and phonological structure of the database, showing the process of creating a text corpus. A machine-readable Korean SAMPA convention for the control data input to the MBROLA application is also suggested. Diphone concatenation and prosody manipulation are performed using the MBR-PSOLA algorithm. A set of segment duration models can be applied to the diphone synthesis of Korean.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2003.05a
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• pp.529-536
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• 2003

The majority of previous studios on tolerance synthesis have viewed the issue as a design methodology to determine optimal component tolerances on behalf of a manufacturer. while meeting given assembly tolerance requirements Although a considerable amount of research has been done on this issue. a couple of important questions still remain unanswered First. how ran a design engineer quantitatively incorporate a customer's perception on a product quality into a tolerance synthesis scheme at the early design stage Second. how ran component tolerances and assembly tolerance be optimized in a simultaneous way? To answer these questions. this article presents the customer-driven concurrent tolerance synthesis which is facilitated by the notion of truncated distribution and the use of mathematical programming techniques. while adopting the major principles of Tagurhl philosophy. The work presented in the article is an effort to gain insight, which can be useful in practice when setting up guidelines for an overall tolerance synthesis.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.05a
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• pp.535-539
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• 2001

In these days. the finite element method(FEM) is a very common method for not only a simple vibration analysis but also the optimization of structures. Since the finite element model may contain thousands of degree of freedom, the eigensolutions require extreme computing power, which will result in a serious time-consuming problem. Thus, many researchers have challenged to find more improved modeling techniques and calculating methods to overcome such problems. The Guyan reduction method and the substructure synthesis method are typical examples of such methods. Of the substructure synthesis method, the component mode synthesis method (CMS) is widely used for dynamic analysis of structure. In this study. for the efficient analysis of jet loom structure. Component Mode Synthesis was carried out. The results of the finite element program developed are compared with those of the commercial package program ANSYS for the validation of the program. The results obtained by the program showed a good agreement with those of ANSYS. The program will be further refined and verified by test to yield more accurate results.

• Journal of KSNVE
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• v.8 no.1
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• pp.139-145
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• 1998

A great deal of effort has been invested in upgrading the performance and the efficiency of dynamic analysis of mechanical structures. Using experimental modal analysis(EMA) or finite element analysis(FEA) data of mechanical structures, the performance and efficiency can be effectively evaluated. In order to analyze complex structures such as automobiles and aircrafts, for the sake of computing efficiency, the dynamic substructuring techniques that allow to predict the dynamic behavior of a structure are widely used. Through linking a modal model obtained from EMA and an analytical model obtained from FEA, the best conditioned strucutres can be proposed. In this study, a new algorithm of substructre synthesis method, Multi-FRF synthesis method, is proposed to analyze a structure composed of many substructures.

• Proceedings of the Acoustical Society of Korea Conference
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• 1998.08a
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• pp.87-92
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• 1998

In general, the synthesis unit database was constructed by recording isolated word. In that case, each boundary of word has typical prosodic pattern like a falling intonation or preboundary lengthening. To get natural synthetic speech using these kinds of database, we must artificially distort original speech. However, that artificial process rather resulted in unnatural, unintelligible synthetic speech due to the excessive prosodic modification on speech signal. To overcome these problems, we gathered thousands of sentences for synthesis database. To make a phone level synthesis unit, we trained speech recognizer with the recorded speech, and then segmented phone boundaries automatically. In addition, we used laryngo graph for the epoch detection. From the automatically generated synthesis database, we chose the best phone and directly concatenated it without any prosody processing. To select the best phone among multiple phone candidates, we used prosodic information such as break strength of word boundaries, phonetic contexts, cepstrum, pitch, energy, and phone duration. From the pilot test, we obtained some positive results.

• 제어로봇시스템학회:학술대회논문집
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• 1990.10b
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• pp.1265-1270
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• 1990

A prototype integrated system and its theories for distributed SISO control structure synthesis of complete chemical plants is developed. The scope of this work includes control structure synthesis not only of simple units with unspecified control loops but also of the complex process at preliminary and basic design stage. Hierarchical approach and dual-decomposition strategy (that is multi-layer decomposition and multi-echelon decomposition) is applied to this system. Because automatic control structure synthesis of complex plants is a problem defined as a series of knowledge-intensive tasks within multiple spaces, the established methodology is complemented by not only techniques from knowledge-based expert systems but also shortcut and rigorous control theories. This system is used for education of control designers, process engineers, operators and students as well as for operability studying, in-line and on-line process control structure synthesis.

• Journal of Industrial Technology
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• v.35
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• pp.89-94
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• 2015

Graphene is a carbon-based two dimensional honeycomb lattice with monoatomic thickness and has attracted much attention due to its superior mechanical, electronic, and physical properties. Here, we present a synthesis of high quality graphene on Pt substrate using a chemical vapor deposition (CVD). We optimized synthesis condition with various parameters such as synthesis temperature, time, and cooling rate. Based on the results, we concluded that graphene synthesis is driven by mainly carbon adsorption on surface rather than precipitation of carbon which is dominant in other metal substrate. In addition, Pt substrate can be repeatedly used several times with high quality graphene.

• Asian-Australasian Journal of Animal Sciences
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• v.11 no.6
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• pp.713-717
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• 1998

The synergistic effect of fetal calf serum (FCS) and chicken embryo extract (CEE) on protein synthesis of chicken embryo myoblasts was examined. Myoblasts were derived from chicken embryo cultured for 14 days by trypsin digestion and cultured in 5% $CO^2/95%$ air at $37^{\circ}C$. When myoblasts were cultured at the low level of cell density (20-50% of well), CEE enhanced the ability of FCS to stimulate protein synthesis of myoblasts. However, there was no significant effect of CEE to stimulate protein synthesis of myoblasts cultured at high level of cell density (100% of well).