• Annual Conference on Human and Language Technology
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• 1999.10e
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• pp.231-236
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• 1999

시간표현은 문장에서 다른 명사와 결합하여 복합어를 이루는 경우가 있고, 용언과 결합하여 시간 부사의 역할을 하는 경우가 있는데, 이는 구문 분석에 있어서 중의적 해석이 두드러지며, 그 결과 구문 분석의 오류를 빈번히 야기하기도 한다. 본 논문에서는 이러한 시간 관계의 표현을 대량의 말뭉치로부터 획득하고 이들을 부분문법(local grammar)으로 표현한 후, 이것을 FST(Finite State Transducer)를 이용하여 부분 구문분석을 하고자 한다. 이를 위해 5천만 어절의 말뭉치에서 259개의 시간 단어를 추출하였고, 시간 단어들의 의미적 또는 기능적 사용에 의해서 26개의 어휘 범주로 분류하고 각 범주들의 결합관계를 일반화하였다. 실험을 통하여 인식을 위한 시간표현의 결합관계는 최고 97.2%의 정확률을 보였고, 품사태깅에 있어서는 평균 96.8%의 정확률을 보였다. 이는 시간 표현의 결합관계가 부분 구문분석에 있어서 유용한 정보임을 보여준다.

• Transactions of the Korean hydrogen and new energy society
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• v.16 no.4
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• pp.324-333
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• 2005

The kinetics of external hydrogen embrittlememt is considered. The equation of the crack growth rate (CGR) is derived from modification of the model developed by Wilkinson and Vitek. After calculation of hydrogen pressure build-up in the void, the effect of the internal hydrogen pressure on the void growth is added. The CGR is expressed by two terms. One is the term dependent on the critical stress, which is exactly same as Wilkinson and Vitek. The other is term dependent on the pressure of the hydrogen in void.

• Journal of Korean Institute of Industrial Engineers
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• v.17 no.2
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• pp.75-86
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• 1991

This paper presents a methodology to enable the tolerances on mating parts of an assembly to be specified and be compatible to the precision of an assembly robot so as to achieve maximum system performance. The measure of performance is defined as the Probability of Successful Assembly (PSA). A typical loose fastener assembly, usually called peg-in-a-hole is investigated. The Geometric Tolerancing System is adopted to represent position tolerances of mating parts. Two models are presented by considering modifiers on a position tolerance, Regardless of Feature Size (RFS) and Maximum Material Condition (MMC). Using these models, it is analyzed how the Standard Limits and Fits recommended by ANSI influence the performance of an assembly robot. For this analysis, the Standard Limits and Fits are transformed to the representation scheme of the Geometric Tolerancing System. Due to low PSAs when the Standard Limits and Fits are taken into account, the effect of chamfers around a hole is also analyzed.

• Journal of Information Display
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• v.4 no.3
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• pp.12-16
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• 2003

In connection with the ion exchange strengthening on soda-lime-silicate, substrate glass for display use was investigated. In the processing, the temperature was varied during the ion exchange in order to make stress profile and to determine optimum condition. In the present work, we found that the maximum value of strength was 617.8 MPa after an ion exchange process at 470 $^{\circ}C$ for 1h, and then, at 450 $^{\circ}C$ for 24h. Also, the effect of residual stress placed on the near surface was measured by analyzing the number of crack branches and brittleness. This approach allowed us the residual stress profile to be engineered to improve mechanical reliability.

• Korean Journal of Agricultural Science
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• v.38 no.4
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• pp.711-716
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• 2011

Casein micelles are the basic building block of rennet-induced gels. The stiffness of these gels is increased with reaction time. This is probably due to the continuous participation of activated casein micelles into growing network. Dual binding model of casein micelles, which explains assembly of casein and colloidal calcium phosphate, can provides fairly reasonable explanation for the changes in mechanical properties of rennet-induced gels made from different milk pHs and varying colloidal calcium phosphates. The changes in stiffness of these gels would be used for controlling textural properties of cheeses.

• 한국전산유체공학회:학술대회논문집
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• 2003.08a
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• pp.126-131
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• 2003

A series of computational simulations have been carried out for supersonic flows in a scram jet engine with and without a cavity. Transverse injection of hydrogen, a simplest form of fuel supply, is considered in the present study with the injection pressure varying from 0.5 to 1.5 MPa. The corresponding equivalence ratios are 0.167 - 0.50. The work features detailed resolution of the flow dynamics in the combustor, which was not typically available in most of the Previous studies. In particular, oscillatory flow characteristics are captured at a scale sufficient to identify the underlying physical mechanisms. Much of the flow unsteadiness is related not only to the cavity, but also to the intrinsic unsteadiness in the flowfield. The interactions between shock waves and shear layer may cause a large excursion of flow oscillation. The role of the cavity and injection pressure are examined systematically.

• Steel and Composite Structures
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• v.11 no.1
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• pp.21-38
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• 2011

This study examines the influence of curved, steel, I-girder bridge configuration on girder end reactions and cross frame member forces during seismic events. Simply-supported bridge finite element models were created and examined under seismic events mimicking what could be experienced in AASHTO Seismic Zone 2. Bridges were analyzed using practical ranges of: radius of curvature; girder and cross frame spacings; and lateral bracing configuration. Results from the study indicated that: (1) radius of curvature had the greatest influence on seismic response; (2) interior (lowest radius) girder reactions were heavily influenced by parameter variations and, in certain instances, uplift at their bearings could be a concern; (3) vertical excitation more heavily influenced bearing and cross frame seismic response; and (4) lateral bracing helped reduce seismic effects but using bracing along the entire span did not provide additional benefit over placing bracing only in bays adjacent to the supports.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.33 no.2
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• pp.148-153
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• 2010

Nowadays, customers have increasing needs, so more and more enterprises are selling their products with additional services and or contents. The emergence of service added to the product leads to the emergence of the Product-Service Systems(PSS). Many researches related to PSS are mainly concerned with general PSS and PSS modeling, which can not readily assist manufactures of consumer products to implement and realize PSS solution. We have wondered whether customers can distinguish service functions from product functions. Through the case studies on Apple and Nintendo and the survey on the representative 5 IT products, we propose the design factors of products and services for PSS.

• Journal of the Korean Society of Propulsion Engineers
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• v.4 no.1
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• pp.74-92
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• 2000

A numerical analysis has been conducted to study the transient flowfield during the transition from the booster to sustainer phase in an integrated rocket ramjet (IRR) propulsion system. Emphasis is placed on the unsteady inlet aerodynamics, fuel/air mixing in an entire ramjet engine during the flow transient phase. The computational geometry consists of the entire IRR engine, including the inlet, the combustion chamber, and the exhaust nozzle. Turbulence closure is achieved using a low-Reynolds-number two-equation model. The governing equations are solved numerically by means of a finite-volume, preconditioned flux-differencing scheme over a wide range of Mach umber. Various important physical processes are investigated systemically, including terminal shock train.

• Journal of the Optical Society of Korea
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• v.11 no.2
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• pp.51-54
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• 2007

A holographic demultiplexer aimed at producing low polarization dependence loss using a long period volumetric diffraction grating inside photopolymer has been reported and experimentally demonstrated. To obtain the long period gratings, two kinds of gratings are recorded by angle of $4^{\circ}\;and\;6^{\circ}$ corresponding to the polarization dependence property of below 0.5 dB. From the experimental results, we demonstrate the 0.8 nm-spaced 21 channel holographic demultiplexer with the polarization dependence loss of less than -0.38 dB, the channel uniformity of 0.495 dB, and the channel crosstalk of -13 dB.