• 공업화학
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• 제26권1호
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• pp.23-28
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• 2015

옻나무에서 추출한 우루시올은 우수한 열안정상과 항균성을 나타내며, 이러한 특성을 기능성 패키징에 응용하기 위하여 폴리우루시올(YPUOH) 분말을 제조하였다. 제조한 YPUOH 분말과 저밀도 폴리에틸렌(LDPE)을 twin screw extruder system을 이용하여 다른 세 가지 조성의 LDPE/YPUOH 복합필름을 제조하였다. 기능성 패키징 소재로서의 응용 가능성을 알아보기 위하여 LDPE/YPUOH 복합필름에 대한 모폴로지, 열적 특성, 항균 특성, 배리어 특성을 조사하였다. LDPE와 YPUOH의 상호작용은 약하지만, 잘 분산된 복합필름 제조가 가능하였으며, YPUOH의 도입에 따라 열안정성은 증가하였다. YPUOH 분말의 우수한 항균특성은 제조한 LDPE/YPUOH의 복합필름에서도 E. coli에 대하여 99.9%의 우수한 항균활성(R)을 확인할 수 있었다. 또한, LDPE/YPUOH 복합필름의 수분에 대한 배리어 특성은 YPUOH의 함량이 증가함에 따라 향상되었으며, 이는 YPUOH가 수분에 대한 배리어성 필러로서 작용하며, 또한 복합필름의 표면 특성을 소수성으로 변화시켜주는 것에 기인한다. 저함량의 YPUOH 도입에 따른 LDPE의 내열성, 항균 특성, 수분에 대한 배리어 특성의 향상은 옻 추출물로 제조한 YPUOH가 패키징 소재의 기능성 필러로서 응용 가능성이 높다는 것을 의미한다.

• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 2003년도 The Korea-Japan Joint Symposium
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• pp.102-102
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• 2003

TLCP/polyester composite fibers (TPCFs) based on melt blends of PEN, PET, and TLCP were prepared by melt blending and spinning process to achieve high performance fibers. Reinforcement effect and TLCP fibrillar structure resulted in improvement of mechanical properties for TPCFs. The increase in the apparent crystallite size was attributed to the development of larger crystallites and more ordered crystalline structures in the annealed TPCFs. Molecular orientation was an important factor to determine mechanical property of TPCFs.

• 대한수학회지
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• 제38권2호
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• pp.321-336
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• 2001

A Feynman functional formulation is given for the Global Positioning System, GPS. Both the sequential and analytic Feynman functionals are presented for the classical, exterior, gravity problems which included rigid body rotations, special relativity and some general relativity corrections. A mathematically rigorous approach is introduced whose solutions exist, are unique and which depend continuously on the intial data. This formulation is convergent and has the finite approximation property. It is emphasized that all of the problems studied are classical (not quantum) evolution systems.

• 대한수학회논문집
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• 제21권2호
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• pp.397-407
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• 2006

We construct polynomial-fitting interpolation rules to agree with a function f and its first derivative f' at equally spaced nodes on the interval of interest by introducing a linear functional with which we produce systems of linear equations. We also introduce a matrix whose determinant is not zero. Such a property makes it possible to solve the linear systems and then leads to a conclusion that the rules are uniquely determined for the nodes. An example is investigated to compare the rules with Hermite interpolating polynomials.

• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 2003년도 The Korea-Japan Joint Symposium
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• pp.87-87
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• 2003

Three kinds of acrylic polymers containing silk protein were synthesized, which are (1) blending of silk fibroin (SF) fiber and polyacrylonitrile (PAN); (2) graft-copolymer of PAN onto SFs; (3) random-copolymer synthesized by copolymerization of acrylonitrile (AN) and silk fibroin peptide (SFP) with vinyl groups, and their solubility, thermal property, and moisture absorption was investigated, respectively. These polymers have difference solubility and attributable to their structure. Their excellent thermal stabilities and better moisture absorptions were indicated.

• 한국경영과학회지
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• 제32권3호
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• pp.17-31
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• 2007

In this paper, we consider a service system with bi-functional servers, which can switch between the primary service room and the secondary room. A service policy is characterized by the switching paints which depend on the queue length in the primary service room and the service level requirement constraint of the secondary room. The primary service room is modeled as a Markovian queueing system and the throughput of the primary service room is function of the total number of bi-functional servers. the buffer capacity of the primary service room, and the service policy. There is a revenue obtained from throughput and costs due to servers and buffers. We study the problem of simuitaneously determining the optimal number of servers, buffer capacity, and service policy to maximize profit of the service system, and develop an algorithm which can be successfully applied with the small number of computations.

• 한국분말재료학회지
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• 제21권1호
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• pp.16-20
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• 2014

In order to fabricate the porous $Al_2O_3$ with dispersion of nano-sized Cu particles, freeze-drying of camphene/$Al_2O_3$ slurry and solution chemistry process using Cu-nitrate are introduced. Camphene slurries with 10 vol% $Al_2O_3$ was frozen at $-25^{\circ}C$. Pores were generated by sublimation of the camphene during drying in air. The sintered samples at 1400 and $1500^{\circ}C$ showed the same size of large pores which were aligned parallel to the sublimable vehicles growth direction. However, the size of fine pores in the internal walls of large pores decreased with increase in sintering temperature. It was shown that Cu particles with the size of 100 nm were homogeneously dispersed on the surfaces of the large pores. Antibacterial test using fungus revealed that the porous $Al_2O_3$/1 vol% Cu composite showed antifungal property due to the dispersion of Cu particles. The results are suggested that the porous composites with required pore characteristics and functional property can be fabricated by freeze-drying process and addition of functional nano particles by chemical method.

• 펄프종이기술
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• 제42권5호
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• pp.37-46
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• 2010

This study was carried out to develop new application field and obtain the basic data of mixed paper with wood pulp and chitosan fiber for producing functional paper. Two types of wood pulp, such as SwBKP and HwBKP, were mixed with chitosan fiber. Physical and optical properties, water vapor absorption, air permeability, antibacterial activity and ash were measured. And the surface morphology of manufactured paper was observed using SEM. The results are as follows. It was revealed that density, breaking length, burst index, tear index, folding endurance and brightness were reduced but water vapor absorption and air permeability were on the rise in the structural view of SwBKP according to increasing the chitosan fiber ratio. Those HwBKP added chitosan fiber were great not only in the strength but also water vapor absorption and air permeability except for brightness. The water vapor absorption was lower and the air permeability was higher in the HwBKP added various chitosan fiber ratios than those with no chitosan fiber. It is estimated that these properties were related with various mixed rate of chitosan fiber. Particularly, air permeability was strongly dependent on the mixed rate of chitosan fiber. The chitosan fiber has superior antibacterial property, comparing with wood fiber. Adding chitosan fiber to the wood pulp was found to have an excellent antibacterial activity, more than 90%. The ashes were determined within 0.5%. Special bonds between chitosan fiber and wood pulp was observed by SEM and it means that the chitosan fiber were combined equally in the interior of wood pulp. In conclusion, mixing wood pulp with chitosan fiber can not only improves the quality of paper but also extend the usage of paper as a functional paper by using inherent property of chitosan. After all, production of functional paper added chitosan fiber is expected for new valuable industry of paper.

• 한국정보과학회논문지:소프트웨어및응용
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• 제33권7호
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• pp.615-623
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• 2006

비기능적 요구사항은 대상 시스템이 지원해야 할 기능적 요구사항의 속성 또는 품질 요구사항을 말하며, 소프트웨어의 품질 속성으로 반영된다. 이러한 비기능적 요구사항은 특히 성능과 관계된 부분의 설계를 결정하기 위한 중요한 기준으로 사용된다. 따라서 비기능적 요구사항은 소프트웨어 개발 생명주기 전반에 걸쳐 계속적으로 고려되고, 관리되어야 한다. 하지만 비기능적 요구사항의 모호성과 비가시적 특성으로 인해 도출 및 명세뿐만 아니라, 관리에도 어려움이 많다. 이에 본 논문에서는 NFR 그래프를 이용해 비기능적 요구사항에 가시성을 부여하고 비기능적 요구사항을 설계에 반영하여 비기능적 요구사항 관리의 효율성을 높이기 위한 비기능적 요구사항의 추적 기법을 제안한다. 비기능적 요구사항 개발 절차에 따라 지능형 조명 제어 시스템의 성능 요구사항 추적 방법을 사례연구로 수행하였으며, 이를 통해 종합적으로 비기능적 요구사항 관리의 효율을 높이고자 한다.

• 한국축산식품학회지
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• 제32권6호
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• pp.695-705
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• 2012

Dietary fiber naturally present in various sources of cereals, legumes, fruits and vegetables plays a physiological role in human health, such as lowering cholesterol and blood pressure, improving blood glucose control in diabetes, helping with weight loss and management, and reducing cancer risk. In addition, dietary fibers have has been added as a functional food ingredient to food products to provide water-holding capacity, viscosity, gel-forming ability, and fat-binding capacity to food products. These beneficial characteristics of dietary fiber components can improve the image of meat products to be healthy and functional food products. This article reviews the concept and current definition of dietary fibers in food products along with their health benefits and functional characteristics. Dietary fibers from different sources like cereals, legumes, fruits, and vegetables and soluble dietary fibers have been applied as functional ingredients to various types of meat products, such as beef patties, ground beef and pork, pork and chicken sausages, meatballs, and jerky etc. Based on the application of dietary fibers to different types of meat products, possible future characteristics in selecting appropriate dietary fiber ingredients and their proper incorporation are explored to develop and produce healthy and functional meat products with high dietary fiber contents.