• The Korean Journal of Rheology
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• v.10 no.2
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• pp.82-91
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• 1998

액정고분자/폴리카보네이트 혼합계로 구성된 분자복합계를 쉬트상으로 가공할 때 취 약해지기 쉬운 횡단면 방향의 물성을 향상시키기 위하여 미세섬유상의 배향을 in-situ 상태 로 적절히 제어할수 있는 Simultaneous Convergent-Divergent(SCD) 다이를 설계·제작하 고 압출실험을 수행하여 얻은 압출 쉬트를 대상으로 구조-물성-가공의 상관관계를 조사하 였다. 액정고분자의 첨가 함량에 따른 토오크와 토출량의 변화는 액정고분자를 10wt% 소량 첨가하였음에도 현저한 감소 효과를 보였으며 약 30wt%일 때 최소로되었다. 이는 액정고분 자가 보강 기능외에 가공특성의 개선에도 큰 효과가 있어 가공조제로서의 가능성을 보이는 결과로 혼합계의 유변학적 특성 결과에서도 확인할수 있었다. 또 DSC와 DMA를 이용한 열 분석 결과 액정고분자의 함량이 증가함에 따라 PC의 유리전이온도가 다소 감소하는 현상을 보임에 미루어 이 혼합계는 부분적으로 상용성을 갖는 것으로 볼수 있으며 모폴로지 분석을 통해서도 이를 확인할수 있었다. TLCP/PC 혼합계로 구성되는 분자복합재를 SCD 다이를 사용하여 제조한 압출 쉬트의 방향성에 따른 기계적 물성은 기존의 쉬트 다이보다 흐름방향 으로는 다소 낮은 물성치를 보이지만 횡단면 방향으로는 물성이 현저히 향상됨을 관찰할수 있었다. 모폴로지 분석결과 기존의 쉬트 다이의 경우 벽면 부근에서는 액정고분자가 미세섬 유상으로 형성되어 흐름방향으로 배향되어 있지만 중심부에서는 액정 상태로 존재하는 반 면, SCD 다이의 경우 미세섬유상으로 형성된 액정고분자가 벽면에서부터 중심부로 갈수록 횡단면 방향으로 서서히 배향되어 있음을 확인할수 있었다.

• Journal of Animal Science and Technology
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• v.50 no.1
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• pp.89-98
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• 2008

This experiment was carried out to investigate the combination feeding of β-glucan and multi-species probiotics on growth performance, various lipid concentrations of serum, antibody production and cecal microbial profiles in broiler chicks. A total of six hundred 1-d-old male broiler chicks were divided into five groups, placed into four pens per group(30 birds per pen) and fed one of five non-medicated experimental diets(T1, 0.15% multi-species probiotics; T2, 0.1% β-glucan+0.15% multi-species probiotics; T3, 0.3% multi-species probiotics; T4, 0.1% β-glucan+0.3% probiotics or devoid them as control) for 5 wk. There was no significant difference in feed intake among the groups. The average weight gains and FCR in groups fed diet containing 0.3% probiotics were significantly improved(p<0.05) than control in finisher period(22-35d). The concentration of serum cholesterol ester in groups fed 0.3% probiotics were significantly lowered(p<0.05) as compared to that of the control. Relative weights of liver, spleen, bursa of Fabricius, breast and leg were not influenced by the dietary treatments. The average ND or IB antibody titers in groups fed diets containing β-glucan and probiotics were tended to be increased, but not significantly. The number of cecal lactic acid bacteria was significantly increased(p<0.05) by the dietary β- glucan and probiotics. These results indicated that dietary β-glucan and probiotics exerted a growth- promoting and immune-enhancing effects on broiler chicks. In addition, yeast derived β-glucan, and multi-species probiotics modulated the profiles of cecal microflora, reflecting potential alternative substances to replace antibiotics for feeding broiler.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.28 no.1
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• pp.21-27
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• 2018

Synthesis of ferromagnetic composite materials for the $Cu-BaFe_{12}O_{19}$ system by mechanical alloying (MA) has been investigated at room temperature. A mixture of copper and barium ferrite with a weight ratio of $Cu:BaFe_{12}O_{19}=4:1$, 3 : 2, 2 : 3 and 1 : 4 was used. It is found that $Cu-BaFe_{12}O_{19}$ composite powders in which $BaFe_{12}O_{19}$ is dispersed in copper matrix are successfully produced by mechanical alloying of $BaFe_{12}O_{19}$ with Cu for 80 min. in all composition. The change in X-ray diffraction patterns and magnetic properties reflects the details for the formation of ferromagnetic metal matrix composite of pure Cu and $BaFe_{12}O_{19}$ during mechanical alloying. Magnetization of $Cu-BaFe_{12}O_{19}$ composite powders gradually increases with increasing the amounts of barium ferrite, whereas coercive force of MA powders gradually decreases due to the refinement of barium ferrite powders with ball milling. However, it can be seen that the coercivity of $Cu-BaFe_{12}O_{19}$ MA composite powders with a weight ratio of $Cu:BaFe_{12}O_{19}=4:1$ and 3 : 2 ball-milled for 80 min. is still high value of 1400 Oe and 1450 Oe, respectively suggesting that the refinement of barium ferrite powders during ball milling process tend to be suppressed due to the ductile copper.

• Restorative Dentistry and Endodontics
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• v.36 no.3
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• pp.219-230
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• 2011

Objectives: The aim of this study was to evaluate the optical characteristics such as color and translucency changes before and after light curing, to quantify the CQ and to measure refractive indices of body and opaque shade of resin composites materials. Materials and Methods: Resin composites used in this study were A2 body and A2 opaque shade of Esthet-X, Filtek supreme, Gradia Direct, Clearfil Majesty and Beautifil II. Color and translucency changes before and after light curing were evaluated by colorimeter, the CQ was quantified by GC-MS and refractive index changes were measured by spectroscopic ellipsometer. Results: Translucency parameter (TP) was significantly increased after curing. The CQ content of body shades are higher than that of opaque shades in all resin composites. Refractive index increased after polymerization in all materials and significant difference in ${\Delta}$refractive index was found between body and opaque shade (significance level 0.05). Conclusions: For an accurate shade match, direct shade matching of resin composite should be performed by using the cured material.

• Composites Research
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• v.23 no.3
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• pp.19-30
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• 2010

The present study describes a method for analytical solution to elastic field in structural elements of general symmetric laminated composite materials. The two dimensional plane stress elasticity problems under mixed boundary conditions are reduced to the solution of a single fourth order partial differential equation, expressed in terms of a single unknown function, called displacement potential function. In addition, all the components of stress and displacement are expressed in terms of the same displacement potential function, which makes the method suitable for any boundary conditions. The method is applied to obtain analytical solutions to two particular problems of structural elements consisting of an angle-ply laminate and a cross-ply laminate, respectively. Some numerical results are presented for both the problems with reference to the glass/epoxy composite. The results are highly accurate and reliable as all the boundary conditions including those in the critical regions of supports and loads are satisfied exactly. This verifies the method as a simple and reliable one as well as capable to obtain exact analytical solution to elastic field in structural elements of composite materials under mixed and any other boundary conditions.

• Polymer(Korea)
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• v.29 no.3
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• pp.221-230
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• 2005

Interfacial interactions and interphases played a key role in multicomponent materials irrespectively of the number and type of their components or their actual structure. They were equally important in particulate filled polymer, polymer blends, fibers-reinforced advanced composites, nanocomposites or biomimetic materials. Recognition of the role of the main factors influencing interfacial adhesion and proper surface modification could lead to significant progress in many fields of research and development, as well as in related technologies. Although the role and importance of interfaces and interphases were the same for all multicomponent materials, the surface modification could be always selected according to the objectives targeted, as well as to the characteristics of the particular system. In this wort therefore, several types of surface modification were performed to improve the interfacial interactions between two components in composite system and their results for the composites were investigated.

• The Journal of the Korea Contents Association
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• v.10 no.9
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• pp.421-431
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• 2010

Sustainable development is the main stream of urban development in 21st century. Also, in contemporary cultural space, it is the pivotal paradigm that the development of culture complex and mixture of cultural space, educational facilities, information technology and public space. So, the purpose of this paper lies in presentation for building culture complex belt for innovation city. For this purpose, this paper has reviewed the developmental trend of cultural facilities, has analyzed cultural environment of Naju city, has set the vision and the strategy for Naju innovation city up, and finally has suggested and planned the method of culture complex belt for sustainable new town development.

• Proceedings of the Korean Society for Food Science of Animal Resources Conference
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• 2004.10a
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• pp.1-29
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• 2004

본 연구에서 저알레르기 처리 공정은 Autoclaving, 가열처리, micro wave, dry heating, 초음파, 효소, 인산염, 천연효소, 가용화, 복합처리 등의 처리 공정으로 하였다. 저 allergy처리에서 allergy가 완전히 억제되는 것은 가열처리를 한 것으로 쇄양 B(추출액+가열 3분), autoclave 처리, micro파 처리, dry heating처리, 복합처리를 했을 때이다. 또한 천연효소(키위)를 침지한 후 tolergen과 같이 3분간 가열했을 때 allergy가 억제되는 것으로 나타났다. 즉 가열처리로 인한 단백질 구조 변성으로 이러한 결과를 보인 것으로 보인다. 인산염의 경우도 어느 정도 억제가 되는 것으로 보이고 있다. 나머지 처리들은 거의 효과를 보이고 있지 않다. 천연효소와 tolergen(쇄양)을 그냥 처리했을 때에는 allergy 억제효과는 없는 것으로 나타났다. 우유의 저 allergy 처리는 효소, autoclave, micro 파, NaOH 처리, 복합처리에서 감소되는 것으로 나타났다. 이러한 결과는 western blotting으로도 확인되었으며 그 억제율 %은 식육에서는 상당한 가열처리를 통하여 알레르기를 감소시킬 수 있는 것을 볼 수 있으며 또한 인산염, 가용화(NaOH처리)도 저 알레르기 효과가 있음을 알 수 있다. 키위, 쇄양 단독 처리 시 저 알레르기 효과가 없지만 약간의 가열을 통하여 알레르기가 감소됨을 알 수 있다. 우유는 효소나 autoclave 처리만이 저 allergy 효과가 각각 28%, 45%로 적게 나타났다. 모든 복합처리의 경우에서는 그 억제율이 41-96%로 높은 효과가 있음을 알 수 있다. 천연효소처리와 인산염 처리된 식육의 전자현미경적 관찰은 control과 비교시 조직의 변화가 없고 둘다 근육 단백질 구조를 분산시키는 것으로 나타났다. 또한 고기를 단계별 복합처리로 저 allergy 처리는 단계별로 점차적으로 allergy가 감소되었다. 즉 단계별로 억제가 안되는 것부터 억제되는 처리를 복합적으로 처리한 것으로 그 단계는 천연효소처리에 인산염 처리, 여기에 초음파 처리, 마지막 단계로 3분 끓이면 억제율이 68%까지 억제되었다. 이는 단일처리시 전혀 억제를 못하는 처리를 단계별로 한 단계씩 더해가면 allergy 억제효과가 나타난다고 할 수 있겠다. 초음파 처리도 역시 저 allergy 처리 공정에 이용될 수 있는데 이것은 그 처리로 인해 새로운 알러젠이 생성될 수도 있다. 또한 복합처리로 allergy를 감소시키면 연속적이고 동시적으로 하기 때문에 원가를 절감할 수 있다.

• The Journal of the Korea Contents Association
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• v.10 no.3
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• pp.10-20
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• 2010

This paper presents chunking strategy of a contiguous nouns sequence using semantic class. We call contiguous nouns which can be treated like a noun the compound noun phrase. We use noun pairs extracted from a syntactic tagged corpus and their semantic class pairs for chunking of the compound noun phrase. For reliability, these noun pairs and semantic classes are built from a syntactic tagged corpus and detailed dictionary in the Sejong corpus. The compound noun phrase of arbitrary length can also be chunked by these information. The 38,940 pairs of 'left noun - right noun', 65,629 pairs of 'left noun - semantic class of right noun', 46,094 pairs of 'semantic class of left noun - right noun', and 45,243 pairs of 'semantic class of left noun - semantic class of right noun' are used for compound noun phrase chunking. The test data are untrained 1,000 sentences with contiguous nouns of length more than 2randomly selected from Sejong morphological tagged corpus. Our experimental result is 86.89% precision, 80.48% recall, and 83.56% f-measure.

• Journal of Korea Multimedia Society
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• v.11 no.9
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• pp.1310-1323
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• 2008

Recently, many studies on automated generation of composite Web services have been done. Most of these works compose Web services by chaining their inputs and outputs, but do not consider the functional semantics. Therefore, they may construct unsatisfied composite services against users' intention. Futhermore, they have high time-complexity since every possible combinations of available services should be considered. To resolve these problems, this paper proposes a sophisticated composition method that explicitly specifies and uses the functional semantics of Web services. Specifically, A graph model is constructed to represent the functional semantics of Web services as well as the dependency among inputs and outputs. On the graph, we search core services which provide the requested function ality and additional services which transform between I/O types of the user request and the core services. Then, composite services are built from combinations of the discovered services. The proposed method improves the semantic correctness of composite services by the functional semantics of Web services, and reduces the time complexity by combinations of functionally related services.