• 한국소음진동공학회논문집
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• 제13권2호
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• pp.132-143
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• 2003

Viscoelastic components for vibration isolation or shock absorption in automobiles, machines and buildings are often subject to a high level of static deformation. From the dynamic design point of view, it is requisite to predict dynamic complex stiffness of viscoelastic components accurately and efficiently. To this end, a systematic procedure for complex modulus measurement of the viscoelastic material under large static deformation is often required in the industrial fields. In this paper, dynamic test conditions and procedures for the viscoelastic material under small oscillatory load superimposed on large static deformation are discussed. Various standard test methods are investigated in order to select an adequate test methodology. The influence of fixed boundary condition in the compression tests upon complex stiffness are investigated and an effective correction technique is proposed. Then the uniaxial tension and compression tests are performed and its results are compared with analysis results from conventional constitutive models.

• 한국물환경학회지
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• 제28권6호
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• pp.851-858
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• 2012

This study conducted a result analysis on operation of 26 Rural Community Sewage Treatment Plant (RCSTP) newly constructed in Yeong-yang, Bong-hwa and An-dong areas which are located at the upper region of An-dong Dam and Im-ha Dam. Based on operation result, an analysis on characteristics of sewage in each area and the treatment efficiency of the installed treatment process was conducted. The result of analysis on characteristics of sewage has shown the difference in concentration of the sewage according to area characteristics. Sewage in areas with frequent occurrence of agricultural water and livestock wastewater had high concentration. It is important to select the most suitable treatment process when selecting a treatment process for RCSTP according to properties of sewage in each area. As a result of operation, the disposal efficiency for organic matter and suspended solids was stable with less fluctuation, but the disposal efficiency for nitrogen and phosphorus showed high fluctuation. This signifies that it is necessary to pay attention to operation condition management of nitrogen and phosphorus when operating RCSTP.

• 한국정보과학회논문지:소프트웨어및응용
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• 제32권11호
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• pp.1047-1058
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• 2005

본 논문에서는 에이전트 지식 기반 화상회의 시스템의 유연성(flexibility)을 개선하기 위해서 기존의 서비스 조정 부분을 새롭게 설계한 전략적 지식 에이전트 아키텍처(Strategic-INTER Knowledge Architecture)를 제안한다. 제안한 아키텍처는 서비스 품질에 관한 문제에 있어서 발생한 문제의 성질이나 문제해결의 진행상황을 고려하면서 해결전략을 동적으로 변환하여 유연성 있게 해결한다 여기에서 유연성이란 시스템 내부에서 발생한 변동의 대응 및 이용자가 사용하기 편리한 서비스 제공 능력을 말한다. 한편, 제안 아키텍처를 화상회의 시스템에 적용한다. 본 아키텍처 적용에 의해서 화상회의 시스템의 에이전트 간 협조가 효과적으로 실행되었으며, 이전의 화상회의 시스템에 비해서 제약조건이 강화 된 경우에도 시스템의 유연한 대응이 가능하게 되었음을 제시한다.

• KSBB Journal
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• 제14권4호
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• pp.389-395
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• 1999

Bifidobcterium spp. can provide human being with several beneficial physiological. Therefor, there has been a considerable interest in products Bifidobcterium spp. dietary supplements or as starter cultures for probiotic products that may assint in the improvement of health on the human. But indusrial applications have been limited because Bifidobcterium spp. are sensitive to acidic pH due to organic acid produced by themselves and various conditions. The objective of this study was to establish new method for improvement of Bifidobcterium viability by entrapment im calcium alginate beads. We have a plan to select the most suitable polymer through the comparison with acid tolerance oxygen tolerance and theological properties of polymer. Increase of the viable number of Bifidobcterium induced increasing acid tolerance and oxygen tolernce trough the development of entrapment technique. The 4%, 3030mm diameter) sodium alginate beads led to the best survivability under acid condition. Especially, addition of 6% mannitol, 6% glycerol or 6% sorbitol to the sodium alginate helped a beneficial effect on viability against acid, bile salt, hydrogen peroxide and cold strage. The number of viability of entrapeede cells by retreatment was 96 fold higher than non-entrapeed cells after 5 hours of storage under pH 3 acidic condition. These experimental data clearly demonstrate that a whole cell immobilization by entrapment in calcium alginate beads is an important survival mechanism enable to withstand environmental stresses as the acidic condition, hydrogen peroxide toxicity and frozen state.

• 대한영양사협회학술지
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• 제21권1호
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• pp.72-82
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• 2015

The purpose of this study was to provide preliminary data for competitive dominance in an institutional foodservice environment. Data were collected from 85 experts and practitioners on customer-oriented service contact elements and contact fields in the foodservice industry. PASW Statistics ver.18 and MS Excel were used for data analysis. From the pilot study, 67 service contact-elements were derived. Contribution rate analysis and frequency analysis in each contact field were performed in order to categorize four factors, including environment-oriented contact, product-oriented contact, service-oriented contact, and image-oriented contact fields. Thirty three contact elements were derived, and environment-oriented contact consisted of eight contact-elements (cleanliness of restaurant/kitchen, etc.), product-oriented contact consisted of twelve contact-elements (food taste, etc.), service-oriented contact consisted of seven contact-elements (service quality, etc.), and image-oriented contact consisted of six contact-elements (image/reputation, etc.). The results of study will be useful to develop an effective marketing program for competitive dominance in an competitive foodservice industry environment.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1998년도 가을 학술발표회 논문집
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• pp.439-446
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• 1998

One of the most important roles in the nonlinear dynamic structural analysis is to select a proper ground excitation, which dominates the response of a structure. Because of the lack of recorded accelerograms in Korea, a stochastic model of ground excitation with various dynamic properties rather than recorded accelerograms is necessarily required. If all information is not available at site, the information from other sites with similar features can be used by the procedure of seismic hazard analysis. Eliopoulos and Wen identified the parameters of the ground motion model by the empirical relations or expressions developed by Trifunac and Lee. Because the relations used in the parameter identification are largely empirical, it is required to apply the artificial neural networks instead of the empirical model. Additionally, neural networks have the advantage of the empirical model that it can continuously re-train the new recorded data, so that it can adapt to the change of the enormous data. Based on the redefined traditional processes, three neural-networks-based models (FAS_NN, PSD_NN and INT_NN) are proposed to individually substitute the Fourier amplitude spectrum, the parameter identification of power spectral density function and intensity function. The paper describes the first half of the research for the development of Neural-Networks-based model for the generation of an Artificial earthquake and a Response Spectrum(NNARS).

• 대한전자공학회논문지SP
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• 제41권2호
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• pp.73-78
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• 2004

본 논문에서는 블록정합 알고리즘을 영상 블록들의 상관도 함수로 모델링하여, 고속 블록정합 방법을 위한 탐색 패턴을 유도하였으며, 이는 고속 블록정합 방법에서 주로 사용되는 다이아몬드 형태의 탐색 패턴에 대한 이론적인 기반을 제공한다. 이와 더불어, 능동적인 탐색 패턴과 물체의 움직임에 따른 통계적인 특성을 사용하여 새로운 고속 블록정합 움직임 예측방법을 제안하였다. 적절한 움직임 탐색 패턴을 얻기 위해 움직임 벡터와 영상간 블록들의 차이값 사이의 통계적인 관계를 이용하였다. 제안한 방법을 움직임 탐색 패턴을 능동적으로 변화시키면서 다른 고속 블록정합 방법들과 비교해 보면, 요구되는 탐색점의 개수를 감소시키면서 움직임 예측성능을 향상됨을 확인할 수 있었다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2019년도 춘계 학술논문 발표대회
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• pp.34-35
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• 2019

In recent years, the construction industry has also applied the dry method that can be assembled in the field by industrialization and factory production, which is free from climatic effects and can reduce the cost due to mass production and simplify the work in the field. Among the building materials used in this dry method, ALC products are made by mixing calcium oxide, gypsum, cement, and water in silica and putting them in an autoclave to create voids in the interior through steam curing at high temperature and pressure. But it requires curing cycle conditions of warming, isothermal, and temperature curing. It depends on the performance of the product depending on the curing conditions, the economical efficiency due to high oil prices, the emission of greenhouse gases by the use of fossil fuels. Experiments were conducted to select an appropriate animal protein foam for lightweight foamed concrete block which was cured by applying a prefilling method to replace existing ALC products. As a result of investigating the characteristics of lightweight foamed concrete by type of animal protein foam, it is considered that FP3 is most suitable for manufacturing lightweight foamed concrete block.

• 한국생산제조학회지
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• 제18권5호
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• pp.514-520
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• 2009

Titanium is one of the most attractive materials due to their superior properties of high specific strength and excellent corrosion resistance. The applications in aerospace and medical industries demand machining process more frequently to obtain more precise products. Machining of titanium is faced with strong challenges such as increased component complexity i.e. airframe components manufacturing processes. The machining cost on titanium have traditionally demanded high cutting tool consumable cost and slow machining cycle times. Similarly, the high wear of the cutting tools restricts the cutting process capabilities. Titanium screws applied to fasten parts In the several corrosion environment. In the thread cutting of titanium alloys, the key point for successful work is to select proper cutting methods and tool materials. This study suggests a guidance fur selecting the cutting methods and the tool materials to improve thread quality and productivity. Some experiments investigate surface roughnesses, cutting forces and tool wear with change of various cutting parameters including tool materials, cutting methods, cutting speed. As the results, the P10 type insert tip was assured of the best for thread cutting of Ti-6Al-4V titanium alloy. Also the initial depth of infeed was desirable to use the value below 0.5mm as the uniform cutting area method is applied.

• 한국공작기계학회논문집
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• 제17권2호
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• pp.38-44
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• 2008

Titanium and its alloys, due to their superior properties of high specific strength and excellent corrosion resistance, are increasingly used in living applications in the 21century. The applications in aerospace and medical industries demand machining process more frequently to obtain a desired product. But unfortunately, this material is one of the most difficult-to-cut. In the turning process of titanium alloys, the key point for successful work is to select proper tool materials and cutting conditions. This study suggests a guidance for selecting the tool materials and the cutting speeds to improve tool life and surface integrity in Ti-6Al-4V titanium turning process. The experiments investigate the change of surface roughnesses, cutting forces and flank wear with various cutting parameters of tool materials, depth of cuts and feeds. As the results, K10 type of insert tip was assured as the best for turning of Ti-6Al-4V titanium alloy.