• Proceedings of the Korea Information Processing Society Conference
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• 2003.11b
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• pp.1121-1124
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• 2003

스케줄링은 네트워크상의 공유된 자원을 보다 효과적으로 이용하기 위한 것으로서 delay, delay jitter, packet loss rate, throughput과 같은 서비스 값들의 QoA(Quality of Service)를 보장하기 위한 핵심 요소이다. 유선망에서의 스케줄링은 이미 익숙한 영역으로 많은 발전이 되어왔지만, 무선채널의 불안정성이나 사용자의 움직임으로 인해 발생하는 다양한 링크 에러율과 용량 때문에 무선망에서의 직접적용은 많은 문제를 일으키게 된다. 이 논문에서는 기존에 나와 있는 여러 무선 스케줄링 기법중 채널 보상 모델을 이용하여 서비스 차별화(Service Differentiation)와 공평성(Fairness)에 초점을 맞춘 QoS제공 성능향상 스케줄링 알고리즘을 제안하였다.

• Journal of Biomedical Engineering Research
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• v.11 no.1
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• pp.131-140
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• 1990

To improve antithrombogenicity of polymer that used in vascular graft and artificial organs, seeding of human endothelial cells on the polyurethane was studied. Human endothelial cells were ismlated from human umbilical veins, using type I collagenase, and identified with goat anti vWF antibodies. Human endothilial cell seeding was tried upon the polyurethane which has good mechanical property and resists stresses. The hydrophobic polyurethane surface was changed hydrophilic by corona discharf:e treatment. Surface hydrophilicity was measured with Wilhemly plate method and the goniometer. To evaluate matrix protein adsorption, fibronectin adsorption test was done. To eveluate cell adhesion, human endothelial cell attachment forces were measured rising a perfusion chamber of , ism diamter. Less cells were detached from the hydrophilically treated polyurethane. This showed that corona discharge on the polyurethane could improve matrix adsorption and endothelial cell attachment.

• Journal of Korean Society for Quality Management
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• v.20 no.2
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• pp.137-142
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• 1992

MODAPTS has been widely used for establishing the standard time of manual works because of easy application of the system. However this system was developed based on MTM, winch was one of the low task standard. Also in this system, it usually becomes a cause of error in accuracy that all the simultaneous motions(SIMO) should be analyzed in the sequent motions of two hands. In order to improve the weak points of MODAPTS, the structure of time unit and SIMO of MODAPTS was researched, and HITMAP was developed on the basis of Work Factor System which was one of the high task standard. HITMAP is composed of 26 standard elements and it's time unit is MD(1MD=0.1 second) and MGSRMPS is the motion pattern of HITMAP. In this study HITMAP shows more than 95% of accuracy to WF. Therefor, it is expected that HITMAP can be used for the improvement of productivity and incentive systems.

• Kyungpook Mathematical Journal
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• v.55 no.2
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• pp.345-353
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• 2015

Subnormality of bounded weighted composition operators on $L^2({\Sigma})$ of the form $Wf=uf{\circ}T$, where T is a nonsingular measurable transformation on the underlying space X of a ${\sigma}$-finite measure space (X, ${\Sigma}$, ${\mu}$) and u is a weight function on X; is studied. The standard moment sequence characterizations of subnormality of weighted composition operators are given. It is shown that weighted composition operators are subnormal if and only if $\{J_n(x)\}^{+{\infty}}_{n=0}$ is a moment sequence for almost every $x{{\in}}X$, where $J_n=h_nE_n({\mid}u{\mid}^2){\circ}T^{-n}$, $h_n=d{\mu}{\circ}T^{-n}/d{\mu}$ and $E_n$ is the conditional expectation operator with respect to $T^{-n}{\Sigma}$.

• Journal of The Korean Astronomical Society
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• v.34 no.4
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• pp.321-323
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• 2001

Compressible, magnetohydrodynamic (MHD) turbulence in two dimension is studied through high-resolution, numerical simulations with the isothermal equation of state. First, hydrodynamic turbulence with Mach number $(M)_{rms}\;\~$1 is generated by enforcing a random force. Next, initial, uniform magnetic field of various strengths with Alfvenic Mach number Ma $\gg$ 1 is added. Then, the simulations are followed until MHD turbulence is fully developed. Such turbulence is expected to exist in a variety of astrophysical environments including clusters of galaxies. Although no dissipation is included explicitly in our simulations, truncation errors produce dissipation which induces numerical resistivity. It mimics a hyper-resistivity in our second-order accurate code. After saturation, the resulting flows are categorized as SF (strong field), WF (weak field), and VWF (very weak field) classes respectively, depending on the average magnetic field strength described with Alfvenic Mach number, $(Ma)_{rms}{\ge}1$, $(Ma)_{rms}{\~}1$, and $(Ma)_{rms}{\gg}1$. The characteristics of each class are discussed.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2002.05a
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• pp.916-922
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• 2002

본 연구는 WfMS라는 사용환경 하에서, 워크플로우 프로세스라는 대상 객체를 BOM(bill of material) 정보로 부터 High Level Petri net 형식으로 자동적으로 생성할 수 있는 엔진의 개발을 궁극적인 목표로 설정하고 있다. BOM은 제조되는 제품의 구조에 대한 정보를 지니고 있다. 관리 및 생산이라는 두 도메인 사이의 차이점에도 불구하고, 생산 분야의 BOM 정보의 이용방식이 관리 프로세스의 설계에도 이용될 수 잇다는 사실을 먼저 설명한다. 워크플로우 프로세스는 Petri Net의 형식으로 표시한다. 주어진 BOM으로부터 이에 대응하는 petri net을 생성할 수 있는 매핑 알고리즘을 소개한다. 이러한 이론 및 알고리즘을 기반으로 하여, 주어진 BOM 정보로부터 이에 대응하는 Petri Net 정보를 자동으로 생성시키는 프로세스 디자이너의 프로토타입을 구현하여 소개한다.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2002.04b
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• pp.53-53
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• 2002

본 연구에서는 산화텅스텐($WO_3$) 분말을 이용하여 여러 금속 기판에 텅스텐 박막을 코팅하는 방법에 관한 연구를 수행하였다. 본 연구에서 언급되는 W 코팅은 Lee 등이 보고한 W, Cu 산화물을 이용하여 W-Cu 복합분말을 제조하는 것으로부터 아이디어가 출발되었으며, 본 연구의 결과는 기존의 6불화 텅스텐 가스($WF_6$) 를 열 분해하여 증착시키는 화학증착법(CVD: chemical vapor deposition)과 순수 텅스텐 target을 sputtering하여 증착시키는 물리증착법(PVD: physical vapor deposition)과 달리, 산화텅스텐 분말, 금속 기판, 및 수소 가스만을 사용하기 때문에 경제적으로 큰 장점이 있는 새로운 코팅법의 하나로 연구되었다. 본 연구에서는 새로운 코팅법의 기구와 여러 금속에서 코팅되는 W의 코팅 현상 등에 대해 간단히 언급하고자 하였다.

• Journal of the Society of Naval Architects of Korea
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• v.42 no.6 s.144
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• pp.637-643
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• 2005

A new novel Whipping Factor is proposed as a measure of the ship damage potential due to an underwater explosion bubble pulse. The factor was derived from the relationships among the charge weight, its depth and the fluid acceleration due to pulsating gas bubble. From the whipping response analyses for three uniform Timoshenko beams with similar characteristics of real naval surface ships, we have confirmed the maximum bending moment responses of beams due to whipping are almost same if the applied whipping factor is constant regardless of the charge weights and depths, which could validate the proposed whipping factor.

• Magazine of the Korea Concrete Institute
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• v.4 no.1
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• pp.97-106
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• 1992

Apparent diffusion coefficients of Cl- ions through hardened cement pastes(HCP), which were partly subs¬tituted blast furnace slag, fly ash and silicafume for ordinary Portland cement, were determined. Also. Cl- and OW concentration of pore solutions which were extracted from HCP and the capacities of the HCP to bind CI were determined. Diffusion coefficients of Cl- ions through HCP were increased with water cement ratio(WfC), but decreased with addition of the blending materials. On the contrary, Cl- and OH concentration of the pore solutions were reduced by adding the blending materials.

• The Transactions of the Korea Information Processing Society
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• v.7 no.5S
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• pp.1609-1619
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• 2000

Workflow means the automation of a business process, in which documents, information or tasks are transferred among participants for business action according to a set of procedural rules, and workflow management system is a system which defines, creates and manages the execution of workflow running one or more workflow engines. In this research, necessity of standardizing current workflow systems is recognized, and problems such as interoperability of current systems, dynamic adaptation to changing business environment and lacking of assessment, management and auditing of business processes are analyzed so that the design and implementation of a workflow system is focused on to offer a solution to the problems. The system is designed and implemented to change dynamically on Run-Time the processes definition defined on Build-Time, and interoperability is enabled by developing workflow engine and related modules based on the WfMC specifications and APIs.