• Title/Summary/Keyword: E171

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LOWER BOUNDS OF THE NUMBER OF JUMP OPTIMAL LINEAR EXTENSIONS : PRODUCTS OF SOME POSETS

  • Jung, Hyung-Chan
    • Bulletin of the Korean Mathematical Society
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    • v.32 no.2
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    • pp.171-177
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    • 1995
  • Let P be a finite poset and let $\mid$P$\mid$ be the number of vertices in pp. A subposet of P is a subset of P with the induced order. A chain C in P is a subposet of P which is a linear order. The length of the chain C is $\mid$C$\mid$ - 1. A linear extension of a poset P is a linear order $L = x_1, x_2, \ldots, x_n$ of the elements of P such that $x_i < x_j$ is P implies i < j. Let L(P) be the set of all linear extensions of pp. E. Szpilrajn [5] showed that L(P) is not empty.

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Application of Combustion in Porous Inert Medium to Thermophotovoltaic Generation of Electricity and Excess Enthalpy Combustion Similarity to both Single and Multi-channels (다공체 내 연소의 열광전 발전에의 적용과 단일, 다중채널 및 다공체 내 초과 엔탈피 연소의 상사성)

  • Lee, Dae Keun
    • 한국연소학회:학술대회논문집
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    • 2012.11a
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    • pp.171-174
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    • 2012
  • Thermophotovoltaics is the direct energy conversion technology from thermal to electric (voltaic) energy via photon radiation, without any thermodynamic cycle. It is, in general, accomplished by immersing solid body in high temperature heat source (e.g. combustion field), in order to achieve high intensity irradiation, and by receiving the radiation thereof on photovoltaic cells. In this paper, advantages of combustion in porous inert medium in applying to the thermophotovoltaics are discussed in a view of its excess enthalpy features. In addition, the similarities of flame behaviors in porous inert medium to both in single and multi-channels are described.

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Solderability Evaluation and Reaction Properties of Sn-Ag-Cu Solders with Different Ag Content (Ag 함유량에 따른 Sn-Ag-Cu 솔더의 Solderability 및 반응 특성 변화)

  • Yu, A-Mi;Lee, Jong-Hyeon;Gang, Nam-Hyeon;Kim, Jeong-Han;Kim, Mok-Sun
    • Proceedings of the KWS Conference
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    • 2006.10a
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    • pp.169-171
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    • 2006
  • Solderability and reaction properties were investigated for four Pb-free alloys as a function of Ag contents; Sn-4.0Ag-0.5Cu, Sn-3.0Ag-0.5Cu, Sn-2.5Ag-0.5Cu, and Sn-1.0Ag-0.5Cu. The alloy of the lowest Ag content, i.e., Sn-1.0Ag-0.5Cu, showed poor wetting properties as the reaction temperature decreased to 230oC. Variation of Ag concentration in the Sn-xAg-0.5Cu alloy shifted exothermic peaks indicating the undercooling temperature in DSC curve. For the aging process at 170oC, the thickness of IMCs at the board-side solder/Cu interface increased with the Ag concentration.

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A Study on Korean Allophone Recognition Using Hierarchical Time-Delay Neural Network (계층구조 시간지연 신경망을 이용한 한국어 변이음 인식에 관한 연구)

  • 김수일;임해창
    • Journal of the Korean Institute of Telematics and Electronics B
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    • v.32B no.1
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    • pp.171-179
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    • 1995
  • In many continuous speech recognition systems, phoneme is used as a basic recognition unit However, the coarticulation generated among neighboring phonemes makes difficult to recognize phonemes consistently. This paper proposes allophone as an alternative recognition unit. We have classified each phoneme into three different allophone groups by the location of phoneme within a syllable. For a recognition algorithm, time-delay neural network(TDNN) has been designed. To recognize all Korean allophones, TDNNs are constructed in modular fashion according to acoustic-phonetic features (e.g. voiced/unvoiced, the location of phoneme within a word). Each TDNN is trained independently, and then they are integrated hierarchically into a whole speech recognition system. In this study, we have experimented Korean plosives with phoneme-based recognition system and allophone-based recognition system. Experimental results show that allophone-based recognition is much less affected by the coarticulation.

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Fabrication of the silicon field emitter araays with H$_{2}$O densified oxide as a gate insulator (H$_{2}$O 분위기에서 치밀화시킨 (densified) 산화막을 게이트 절연막으로 갖는 실리콘 전계방출소자의 제작)

  • 정호련;권상직;이종덕
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.33A no.7
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    • pp.171-175
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    • 1996
  • Gate insulator for Si field emitter is usually formed by e-beam evaporation. However, the evaported oxide requires densification for a stable process and a reduction of gate leakage which results from its Si-rich and nonstoicheiometric structure. In this study, we have developed the process technology able to densify the evaporated oxide in H$_{2}$O ambient. Using this process, we have fabricted thefield emitter array with 625 emitters per pixel, of which gate hole diameter is 1.4.mu.m, for the pixel, anode current of 14.3.mu.A was extracted at a gate bias of 100V and gate leakage was about 0.27% of the total emission current.

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Optimum forming design of A350 LF2 alloy using the deformation processing map (변형 공정지도를 활용한 A350 LF2 합금의 최적성형 조건설계에 대한 연구)

  • Jung, E.J.;Yeom, J.T.;Kim, J.H.;Lee, D.G.;Pak, N.K.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2006.05a
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    • pp.168-171
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    • 2006
  • Hot deformation behavior of A350 LF2 alloy was characterized by compression tests in the temperature range of 800-$1250^{\circ}C$ and the strain rate range of $0.001-10s^{-1}$. The microstructural evolution during hot compression was investigated and deformation mechanisms were analyzed by constructing processing map. Processing maps were generated using the dynamic material model (DMM). The combination of dynamic material model and Ziegler's instability criterion was applied to predict an optimum condition and unstable regions for hot forming.

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Synthesis and Mesomorphism of Polymers with Banana-Shaped Mesogens in the Main Chain

  • Choi, E-Joon;Zin, Wang-Cheol;Kim, Young-Chul;Paek, Sang-Hyon;Chien, Liang-Chy;Samulski, Edward T.
    • 한국정보디스플레이학회:학술대회논문집
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    • 2006.08a
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    • pp.171-174
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    • 2006
  • In this work, we report the synthesis and characterization of azomethine-ester polymers that consist of banana-shaped mesogen in their backbone. Two parts of the key structure of five-ring bent-core mesogen were modified by connecting different angle of central unit (Ar), and introducing lateral substituent into the outer ring (X). The synthetic details includes (1) placing the dioxydodecamethylene unit as a flexible spacer, (2) possessing 2,3- or 2,7-naphthylene, or 1,2-phenylene connection on the central unit, and (3) introducing fluorine or chlorine substituent (X = F or Cl) into the outer phenylene unit.

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Growing High-Quality Ir-Sb Nanostructures by Controlled Electrochemical Deposition

  • Nisanci, Fatma Bayrakceken
    • Journal of Electrochemical Science and Technology
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    • v.11 no.2
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    • pp.165-171
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    • 2020
  • The electrochemical preparation and spectroscopic characterisation of iridium-antimony (Ir-Sb) species is important owing to their potential applications as nanostructure materials. Nanostructures, i.e. nanoflower and nanodisk, of Ir-Sb were electrodeposited on conductive substrates using a practical electrochemical method based on the simultaneous underpotential deposition (UPD) of Ir and Sb from the IrCl3 and Sb2O3 at a constant potential. Electrochemical UPD mechanism of Ir-Sb was studied using cyclic voltammetry and potential-controlled electrochemical deposition techniques. Herein, X-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy, X-ray photoelectron and Raman spectroscopy were used to determine the morphological and structural properties of the electrochemically-synthesised Ir-Sb nanostructures.

Impact Properties of New 3D Composites by Fiber Placement Processing (섬유 자동 배열에 의한 시로운 3D 복합재의 충격특성)

  • Song S-W;Lee C-H;Song J-E;Byun J-H;Um M-K
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 2004.10a
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    • pp.171-174
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    • 2004
  • In order to improve the damage tolerance of the conventional laminated composites, three­dimensional fiber structures incorporated with stitching yams have been utilized in this study. From the newly developed process termed as TAPIS(TApe Placement Incorporated with Stitching), carbon/epoxy composites have been fabricated. Two-dimensional composites with the same stacking sequence as 3D counterparts have also been fabricated for the property comparison. To examine the damage resistance performance the low speed drop weight impact test has been adopted. For the assessment of damage after the impact loading, specimens were subjected to C-scan nondestructive inspection compression after impact(CAI) were also conducted to evaluate residual compressive strength. Although the damage area of 3D composites was greatly reduced$(30-40\%)$ compared with that of 2D composites, the CAI strength did not show drastic improvement.

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Design and Implementation of a Call Control Markup Interpreter and Its Interaction with Voice Dialog Systems (호 제어 마크업 해석기 개발 및 음성 대화 시스템과의 연동)

  • Lee, Kyung-A;Kwon, Ji-Hye;Kim, Ji-Young;Hong, Ki-Hyung
    • MALSORI
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    • no.53
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    • pp.171-183
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    • 2005
  • Call Control eXtensible Markup (CCXML) is a standard language that supports a call control of voice dialog systems such as VoiceXML based systems. CCXML allows developers to handle telephony calls in an easy way without deep knowledge about telephony networks and their switching systems.We design and implement a call control markup interpreter. At the implementation, we use a Dialogic JCT-LS board, but, by designing a wrapping class for CTI (computer telephony board) features, the interpreter can easily adopt other CTI boards. We also design and implement event-based interaction scheme between the interpreter and voice dialog systems. For verifying the interaction scheme, we implement a simple voice dialog system.

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