• 한국전자거래학회지
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• 제8권3호
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• pp.197-217
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• 2003

ebXML은 e비즈니스를 위한 글로벌 표준으로서 그 동안 기업간 협력의 가장 큰 장애물로 여겨졌던 정보 시스템의 이질성을 극복할 수 있는 대안을 제시하는 기술이다. ebXML에서는 전체적 인 프레임워크를 구성하는 주요 요소로서 거래 절차를 기술하는 비즈니스 프로세스, 거래에 이용되는 공통의 용어와 그 의미를 정의하고 있는 핵심 컴포넌트, 거래에 필요한 정보를 저장하고 검색하는 레지스트리, 거래 문서의 전송을 위한 메시징 서비스 등을 정의하고 있다. 이러한 구조를 기반으로 ebXML에서의 거래 절차는 비즈니스 프로세스에서 요구하고 있는 다양한 비즈니스 문서의 교환에 의해서 수행되며, 이때 필요한 비즈니스문서의 모델은 핵심 컴포넌트를 기반으로 저작된다. 본 논문에서는 우선 ebXML의 기술 구조 및 관련기술 동향에 대하여 살펴보고, ebXML 핵심 컴포넌트 및 이를 기반으로 비즈니스 프로세스의 수행에 필요한 비즈니스 문서를 생성하는 기술에 대하여 분석한다.

• 한국재료학회지
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• 제32권12호
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• pp.538-544
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• 2022

In existing ceramic mold manufacturing processes, inorganic binder systems (Si-Na, two-component system) are applied to ensure the effective firing strength of the ceramic mold and core. These inorganic binder systems makes it possible to manufacture a ceramic mold and core with high dimensional stability and effective strength. However, as in general sand casting processes, when molten metal is injected at room temperature, there is a limit to the production of thin or complex castings due to reduced fluidity caused by the rapid cooling of the molten metal. In addition, because sodium silicate generated through the vitrification reaction of the inorganic binder is converted into a liquid phase at a temperature of 1,000 ℃. or higher, it is somewhat difficult to manufacture parts through high-temperature casting. Therefore, in this study, a high-strength ceramic mold and core test piece with effective strength at high temperature was produced by applying a Si-Na-Ti three-component inorganic binder. The starting particles were coated with binary and ternary inorganic binders and mixed with an organic binder to prepare a molded body, and then heat-treated at 1,000/1,350/1,500 ℃ to prepare a fired body. In the sample where the two-component inorganic binder was applied, the glass was liquefied at a temperature of 1,000 ℃ or higher, and the strength decreased. However, the firing strength of the ceramic mold sample containing the three-component inorganic binder was improved, and it was confirmed that it was possible to manufacture a ceramic mold and core via high temperature casting.

• 한국전자거래학회:학술대회논문집
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• 한국전자거래학회 2001년도 International Conference CALS/EC KOREA
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• pp.671-679
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• 2001

사례연구를 통하여 UML Component Design Process의 일관성 및 정확성을 검증한다. Business Concept Model과 Use Case Model을 이용하여 Component Specification Process의 산출물인 Interface, Component Specification 및 Component Architecture 작성 UML Notation을 확장해서 Component 명세에 적용하는 것이 올바른 것인지 확인한다. <>,<>,<>,<>,<>, <>:로 Component Specification이 충분한지를 확인 OCL을 이용하여 Component Specification 중 Component Specification, Interface Specification, Operation Specification, Constraint, Pre/Post Condition의 정의에 유용한지 확인(중략)

• 한국항해항만학회지
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• 제30권10호
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• pp.793-800
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• 2006

본 논문에서는, 1995년도, 2000년도, 2004년도, 국내 26개 항만들을 대상으로 2개의 투입변수(접안능력, 하역능력)와 3개의 산출변수(수출화물처리량, 수입화물처리량, 입출항척수)가 있는 경우에 구성될 수 있는 21개의 DEA모형을 제시하고 효율성을 측정하였다. 또한 그러한 효율성 측정결과를 이용하여 주성분분석을 시행하여 핵심투입변수와 산출변수를 추출하였다. 실증분석의 핵심적인 결과를 살펴보면, 핵심투입 변수는 하역능력, 핵심산출변수는 입출항척수로 나타났다. 정책적인 함의는 항만정책당국이 개별항만들의 핵심투입변수와 산출변수가 어떻게 변화해 왔는지를 검토하여 차후 항만투자와 개발 시에 반드시 고려하고 반영해야만 한다.

• 대한전기학회논문지:전력기술부문A
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• 제55권3호
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• pp.95-101
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• 2006

This paper proposes a modified current differential relay for $Y-{\Delta}$ transformer protection. The relay uses the same restraining current as a conventional relay, but the differential current is modified to compensate for the effects of the exciting current. A method to estimate the circulating component of the delta winding current is proposed. To cope with the remanent flux, before saturation, the core-loss current is calculated and used to modify the measured differential current. When the core then enters saturation, the initial value of the flux is obtained by inserting the modified differential current at the start of saturation into the magnetization cure. Thereafter, the core flux is then derived and used in conjunction with the magnetization curve to calculate the magnetizing current. A modified differential current is then derived that compensates for the core-loss and magnetizing currents. The performance of the proposed differential relay was compared against a conventional differential relay. Test results indicate that the modified relay remained stable during severe magnetic inrush and over-excitation, because the exciting current was successfully compensated. This paper concludes by implementing the relay on a hardware platform based on a digital signal processor. The relay does not require additional restraining signal and thus cause time delay of the relay.

• 한국군사과학기술학회지
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• 제3권1호
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• pp.92-105
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• 2000

Core technologies of powerplants, which are necessary for the development of Korean type combat aircraft, are analyzed. And then, the acquisition methodologies for the technologies are proposed. With respect to the aircraft engine design and manufacturing technologies, simple basic technologies such as component manufacturing and assembling technology come to close to those of advanced countries, but the core technologies were not acquired or in the understanding level only. Therefore, the research on the component manufacturing technology should be specialized for buildup of international competition first, and the research on core technologies such as high pressure compressor design, blisk, FADEC and hollow fan blade design should be concentrated step by step by taking an active participation in the development project of international cooperative aircraft powerplants.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 추계학술대회 논문집
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• pp.859-862
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• 2002

The Core Support Barrel (CSB) is a major component of Reactor Internals, and is designed to support and protect the Reactor Core. In this study, Reactor Core, Core Shroud and CSB were simplified to coaxial cylinders and then the offset of Reactor Core & Core Shroud to the dynamic characteristic of CSB was analyzed. For the beam modes, natural frequencies of the cantilevered cylinder are compared with those of the cantilevered beam. And it was found out that shear modulus must be used correctly to convert the shell model to the equivalent beam model. From the dynamic characteristics of the beam model, it was found out that natural frequencies are proportional to the length of Reactor Core & Core Shroud and inversely proportional to the mass. From the comparison with the dynamic characteristics of a beam model and a lumped-mass model it was found out that the size of lumped-mass must be determined considering both the length and the mass of Reactor Core & Core Shroud.

• 천문학회보
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• 제36권1호
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• pp.47.1-47.1
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• 2011

We studied the evolution of the two mass components system with NFW initial density distribution by direct integration of the Fokker-Planck equations. The low mass component is regarded the dark matter particles while the high mass component is assumed to be conglomerates of baryonic matter in order to depict the 'stars'. While the true mass ratio between these two types of particles should be extremely large, our adopted mass ratio is about 1000 beyond which the dynamical evolution and density distribution tend to converge. Since the dynamical evolution is dominated by the dynamical friction, the high mass component slowly moves toward the central part, and eventually undergoes the core collapse. The system reaches the core-collapse at about $7.1{\times}10^{-3}$ $t_{fh}$ in NFW models, where $t_{fh}$is the dynamical friction time at half-mass radius. The distribution of the high mass component is well fitted by the Sersic profiles or modified Hubble profile when the mass segregation is established. From these results, the surface brightness of elliptical galaxies may be explained by the high mass component experiencing dynamical friction by the dark matter particles. In order for the mass segregation to be effective within Hubble time, the mass of the luminous component should be greater than $10^5M_{\bigodot}$.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 하계종합학술대회 논문집(4)
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• pp.238-241
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• 2000

A fingerprint core-point detection algorithm is presented in this paper. Core-point is useful for fingerprint classification and also for the fingerprint verification since it giver a reference to a fingerprint. Traditional methods of finding the core-point is introduced. These methods are the method using poincare index and the method using sine component of ridge directions. The proposed method is modified algorithm of the latter using the poincare index. The experimental results show that the proposed algorithm achieves almost the same accuracy with faster speed.

• Nuclear Engineering and Technology
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• 제54권5호
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• pp.1890-1901
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• 2022

We have assessed the applicability of the thermal-hydraulic system analysis code, SPACE, to a small modular reactor called SMART. For the assessment, the experimental data from a scale-down integral-test facility, SMART-ITL, were used. It was conformed that the SPACE code unrealistically calculates the safety injection flow rate through the CMT and SIT during a small-break loss-of-coolant experiment. This unrealistic behavior was due to the overprediction of interfacial heat transfer at the steam-water interface in a vertically stratified flow in the tanks. In this study, a special thermal-hydraulic component model has been developed to realistically calculate the interfacial heat transfer when a strong non-equilibrium two-phase flow is formed in the CMT or SIT. Additionally, we developed a special heat structure model, which analytically calculates the heat transfer from the hot steam to the cold tank wall. The combination of two models for the tank are called the special component model. We assessed it using the SMART-ITL passive safety injection system (PSIS) test data. The results showed that the special component model well predicts the transient behaviors of the CMT and SIT.