• Korea-Australia Rheology Journal
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• 제18권4호
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• pp.199-207
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• 2006

Measurements by Luap et al. (2005) of elongational viscosity and birefringence of two nearly monodisperse polystyrene melts with molar masses $M_{w}$ of $206,000g{\cdot}mol^{-1}$ (PS206k) and $465,000g{\cdot}mol^{-1}$ (PS465k) respectively are reconsidered. At higher elongational stresses, the samples showed clearly deviations from the stress optical rule (SOR). The elongational viscosity data of both melts can be modeled quantitatively by the MSF model of Wagner et al. (2005), which is based on the assumption of a strain-dependent tube diameter and the interchain pressure term of Marrucci and Ianniruberto (2004). The only nonlinear parameter of the model, the tube diameter relaxation time, scales with $M_{w}^{2}$. In order to get agreement with the birefringence data, finite chain extensibility effects are taken into account by use of the $Pad\'{e}$ approximation of the inverse Langevin function, and the interchain pressure term is modified accordingly. Due to a selfregulating limitation of chain stretch by the FENE interchain pressure term, the transient elongational viscosity shows a small dependence on finite extensibility only, while the predicted steady-state elongational viscosity is not affected by non-Gaussian effects in agreement with experimental evidence. However, deviations from the SOR are described quantitatively by the MSF model by taking into account finite chain extensibility, and within the experimental window investigated, deviations from the SOR are predicted to be strain rate, temperature, and molar mass independent for the two nearly monodisperse polystyrene melts in good agreement with experimental data.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 추계종합학술대회 논문집(1)
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• pp.259-262
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• 2000

MSF(MultiService Switching Forum) 개념이 도입된 개방형 시스템 구조를 적용한 고성능 스위칭 시스템 개발이 필요하며, Media Gateway System은 ATM망에서 중저속의 Non-ATM 인터페이스를 수용하는 ATM access multiplexer/concentrator로서 ATM 물리계층 기능, ATM 계층 기능, 회선대행 기능, AAL2 trunking 기능, N-ISDN 연동 기능 및 FR/ATM 연동기능을 제공한다. 본 논문에서는 Media Gateway System에 FR/ATM 연동 기능을 구현하기 위하여 적용할 연동 규격을 살펴보고 FR/ATM 연동시스템 구조를 제안하였다.

• 기술사
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• 제42권3호
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• pp.27-31
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• 2009

Recent desalination plant system are being operated by applying one of the technologies as like MSF, MED and, or RO. The production cost of pure water from sea water by the desalination plant was U$9/m$^3$ in 1960, but now has been reduced to U$1/m$^3$ at present. The Power and Desalination Plant Project in Al Cobar of Saudi Arabia gave good chance to us export the similar plant systems actively to the world market. 1Hidd IWPP Project in Bahrain, Taweelah B Extension Project in Abu Dhabi of UAE and Ras Laffan B IWPP of Qatar are the recent large scale desalination projects under construction.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2006년도 하계종합학술대회
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• pp.175-176
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• 2006

본 논문은 IMS 개발-에 있어서 컨버전스 서비스를 지향하는 망 진화 방향을 제안한다. 4 세대 라고 언급하고 있는 4G 네트워크의 핵심인 IMS 는 3GPP 에서 표준화를 진행하며, ITU-T, MSF, TISPAN 과 같은 표준화 단체에서도 유사한 망구조로 제안하고 있다. 그러나 IMS망을 통하여 생성되는 컨버전스 서비스로의 발전에는 고려해야 할 사항들이 많이 있다. 본 논문에서는 망구조를 통하여 단말의 입장과 서비스의 진화방향을 제안한다.

• Membrane and Water Treatment
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• 제8권3호
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• pp.279-292
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• 2017

This study was aimed at ultrafiltration (UF) as a pretreatment before reverse osmosis (RO) within the scheme of hybrid reverse osmosis-multistage flush (RO-MSF) desalination. Seawater at elevated temperature (after MSF heat-exchangers) was used as a feed in this process. The pretreatment system was represented as a set of functionally-linked technological segments such as: UF filtration, backwashing, chemical- enhanced backwashing, cleaning, waste disposal, etc. The process represents the sequences of operating cycles. The cycle, in turn, consists of the following unit operations: filtration, backwashing and chemical-enhanced backwashing (CEB). Quantitative assessment was based on the following indicators: normalized permeability, transmembrane pressure, specific energy and water consumption, specific waste generation. UF pre-treatment is accompanied by the following waste streams: $W1=1.19{\times}10$ power of $-2m^3$ (disposed NaOCl with 0.0044% wt.)/$m^3$ (filtrate); $W2=5.95{\times}10$ power of $-3m^3$ (disposed $H_2SO_4$ with 0.052% wt.)/$m^3$(filtrate); $W3=7.26{\times}10$ power of $-2m^3$ (disposed sea water)/$m^3$ (filtrate). Specific energy consumption is $1.11{\times}10$ power of $-1kWh/m^3$ (filtrate). The indicators evaluated over the cycles with conventional (non-chemical) backwashing were compared with the cycles accompanied by CEB. A positive impact of CEB on performance indicators was demonstrated namely: normalized UF resistance remains unchanged within the regime accompanied by CEB, whereas the lack of CEB results in 30% of its growth. Those quantitative indicators can be incorporated into the target function for solving different optimization problems. They can be used in the software for optimisation of operating regimes or in the synthesis of optimal flow- diagram. The cycle characteristics, process parameters and water quality data are attached.

• 시스템엔지니어링학술지
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• 제12권1호
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• pp.73-87
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• 2016

Combining power generation and water production by desalination is economically advantageous. Most desalination projects use fossil fuels as an energy source, and thus contribute to increased levels of greenhouse gases. Environmental concerns have spurred researchers to find new sources of energy for desalination plants. The coupling of nuclear power production with desalination is one of the best options to achieve growth with lower environmental impact. In this paper, we will per-form a sensitivity study of coupling nuclear power to various combinations of desalination technology: {1} thermal (MSF [Multi-Stage Flashing], MED [Multi-Effect Distillation], and MED-TVC [Multi-Effect Distillation with Thermal Vapour Compression]); {2} membrane RO [Reverse Osmosis]; and {3} hybrid (MSF-RO [Multi-Stage Flashing & Reverse Osmosis] and MED-RO [Multi-Effect Distillation & Reverse Osmosis]). The Korean designed reactor plant, the APR1400 will be modeled as the energy production facility. The economical evaluation will then be executed using the computer program DEEP (Desalination Economic Evaluation Program) as developed by the IAEA. The program has capabilities to model several types of nuclear and fossil power plants, nuclear and fossil heat sources, and thermal distillation and membrane desalination technologies. The output of DEEP includes levelized water and power costs, breakdowns of cost components, energy consumption, and net saleable power for any selected option. In this study, we will examine the APR1400 coupled with a desalination power plant in the Kingdom of Saudi Arabia (KSA) as a prototypical example. The KSA currently has approximately 20% of the installed worldwide capacity for seawater desalination. Utilities such as power and water are constructed and run by the government. Per state practice, economic evaluation for these utilities do not consider or apply interest or carrying cost. Therefore, in this paper the evaluation results will be based on two scenarios. The first one assumes the water utility is under direct government control and in this case the interest and discount rate will be set to zero. The second scenario will assume that the water utility is controlled by a private enterprise and in this case we will consider different values of interest and discount rates (4%, 8%, & 12%).

• 전자공학회논문지
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• 제52권1호
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• pp.140-147
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• 2015

본 연구는 의료기기법이 시행된 이래 의료기기 부작용등 안전성 정보관리를 위한 의료기기 안전성 정보 원내 보고 시스템 설계에 대한 연구이다. 본 연구는 현행 의료기기 부작용등 안전성정보 보고 관리에 대한 법적 규정 및 시스템에 대한 절차와 현황을 파악하고, MSF/CD(Microsoft Solution Framework/Component Design)설계방법론을 적용한 시스템 설계 방법을 적용하여 의료기기 안전성 정보 원내 보고 시스템 구축을 위한 설계를 하였다. 본 연구를 통해 우리나라의 부작용 등 안전성 정보 보고에 대한 식품의약품안전처 고시 규정을 포함한 의료기기 관리 제도를 파악하고, 좀 더 환자의 안전과 의료기기의 위험관리를 효과적으로 할 수 있는 의료기기 안전성 정보 원내 보고 시스템을 설계 및 구축함으로써 의료기기 부작용 등 안전성 정보 보고의 활성화에 이바지 할 수 있기를 기대한다.

• Korea-Australia Rheology Journal
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• 제21권4호
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• pp.203-211
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• 2009

In flows with deformation rates larger than the inverse Rouse time of the polymer chain, chains are stretched and their confining tubes become increasingly anisotropic. The pressures exerted by a polymer chain on the walls of an anisotropic confinement are anisotropic and limit chain stretch. In the Molecular Stress Function (MSF) model, chain stretch is balanced by an interchain pressure term, which is inverse proportional to the $3^{rd}$ power of the tube diameter and is characterized by a tube diameter relaxation time. We show that the tube diameter relaxation time is equal to 3 times the Rouse time in the limit of small chain stretch. At larger deformations, we argue that chain stretch is balanced by two restoring tensions with weights of 1/3 in the longitudinal direction of the tube (due to a linear spring force) and 2/3 in the lateral direction (due to the nonlinear interchain pressure), both of which are characterized by the Rouse time. This approach is shown to be in quantitative agreement with transient and steady-state elongational viscosity data of two monodisperse polystyrene melts without using any nonlinear parameter, i.e. solely based on the linear-viscoelastic characterization of the melts. The same approach is extended to model experimental data of four styrene-butadiene random copolymer melts in shear flow. Thus for monodisperse linear polymer melts, for the first time a constitutive equation is presented which allows quantitative modeling of nonlinear extension and shear rheology on the basis of linear-viscoelastic data alone.

• 전자공학회논문지SC
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• 제48권5호
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• pp.74-80
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• 2011

본 연구는 유통되는 이식형(implantable) 의료기기의 추적(tracking) 및 회수(recall) 처리를 신속하고 정확하게 수행할 수 있는 통합 전산 관리시스템 설계하는 것을 목적으로 한다. 이를 위해 최신 FDA 규정을 만족하는 시스템을 MSF/CD 설계방법론을 기반으로 설계하였다. 추적과 회수의 주요한 4가지 가상 시나리오를 설정하고 workflow diagram을 작성하여 개념설계하였다. 또한 business workflow를 만족하는 서버의 논리 DB를 개발하여 논리설계 단계까지 시스템을 설계하였다. 제안된 시스템으로 이식형 의료기기의 심각한 부작용 등 문제 발생 시 신속하고 정확한 추적과 회수 처리가 가능하여 이식형 의료기기를 장착한 환자의 생명유지 및 국민 건강 보호를 위한 정부 차원의 효율적인 관리가 가능할 것으로 사료된다.

• 한국컴퓨터산업학회논문지
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• 제5권2호
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• pp.311-324
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• 2004

소프트웨어의 개발은 여러 번의 반복(Iteration)을 거치며 각각의 반복은 요구사항 분석, 분석 및 설계, 구현, 그리고 테스트 및 평가 과정을 포함하고 있어 자체로서도 하나의 개발주기를 이룬다. 이러한 반복적인 개발 방법에서는 반복마다 실행 가능한 릴리즈가 산출되고 이는 반복이 거듭될수록 향상되어 결국 최종 시스템으로 발전된다. 전통적인 프로세스와 비교했을 때 빠르고 반복적인 개발 방법이 갖는 장점은 초기에 위험요소를 줄일 수 있고 변경에 대한 관리가 용이하다. 그리고 보다 높은 수준의 재사용이 가능하며, 프로세스가 진행됨에 따라 프로젝트 팀원의 기술을 향상시킬 수 있다. 이러한 결과로 전반적인 고품질을 얻을 수 있다. 본 논문에서는 고객 중심의 요구를 빠르게 적용할 수 있고 짧은 기간에 개발 산출물을 제공할 수 있도록 프로세스 개선의 초점을 둔 빠른 개발 프로세스와 사례연구를 목적으로 하고 있으며, 이를 위해서 제안 프로세스는 NET 기반에서 마르미III, MSF/CD, XP, Agile, PSP, TSP의 공통적이고 핵심 적인 활동을 중심으로 구성하였다.