• Title/Summary/Keyword: VeA

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Shaking table study of a 2/5 scale steel frame with new viscoelastic dampers

  • Chang, K.C.;Tsai, M.H.;Lai, M.L.
    • Structural Engineering and Mechanics
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    • v.11 no.3
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    • pp.273-286
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    • 2001
  • Viscoelastic (VE) dampers have shown to be capable of providing structures with considerable additional damping to reduce the dynamic response of structures. However, the VE material appears to be sensitive to the variations in ambient temperature and vibration frequency. To minimize these effects, a new VE material has been developed. This new material shows less sensitivity to variations in vibration frequency and temperature. However, it is highly dependent on the shear strain. Experimental studies on the seismic behavior of a 2/5 scale five-story steel frame with these new VE dampers have been carried out. Test results show that the structural response can be effectively reduced due to the added stiffness and damping provided by the new type of VE dampers under both mild and strong earthquake ground motions. In addition, analytical studies have been carried out to describe the strain-dependent behavior of the VE damper. The dynamic properties and hysteresis behavior of the dampers can be simulated by a simple bilinear model based on the equivalent dissipated energy principle proposed in this study.

A Study on the Selection of the Optimum Railroad Line using VE-LCC Analysis (VE-LCC 분석을 통한 철도의 최적노선 선정방안 연구)

  • Shin Tae-Kyun;Son Seok-Ku;Lee Seung-Hoon;Koo Kyo-Jin;Hyun Chang-Taek
    • Proceedings of the KSR Conference
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    • 2003.05a
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    • pp.315-320
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    • 2003
  • Selecting a railroad line requires the comparative evaluation of various elements. As a systematic approach to this selection it will be necessary to apply the VE study and the LCC analysis. This study proposes a methodology for selecting the optimum line of the ralroad using VE-LCC analysis. The VE study is performed by following four steps : Information analysis, Function analysis, Alternative evaluation, and Optimum plan selection. The economics evaluation in VE study is using LCC analysis and Sensitivity analysis. Cost items in LCC analysis are classified into bridge, tunnel, rail, and earthwork. We could select the optimum alte-rnatives considering not only cost elements hut also various evaluation element in VE-LCC analysis. The synthetic evaluation process of relative value composition and weighted matrix evaluation

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Styrene-free Synthesis of Flame-retardant Vinyl Ester Resin Films for Hot-melt Prepreg Process (핫멜트 프리프레그 공정용 난연성 비닐에스터 수지 필름의 무 스티렌 합성)

  • Jiseon, Kang;Minji, Kim;Mongyoung, Huh;Seok Il, Yun
    • Composites Research
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    • v.35 no.6
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    • pp.412-418
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    • 2022
  • Flame-retardant vinyl ester (VE) resin films were developed from the mixtures of brominated and non-brominated epoxy resins via esterification with methacrylic acid without reactive diluents. The films were used to fabricate carbon fiber (CF) prepregs via a hot melt impregnation process. The viscosity of VE resins suitable for film production was optimized by mixing low-viscosity bisphenol-A and high-viscosity brominated bisphenol-A epoxy precursors. Increasing the bromine content of the cured VE resin further increased the limited oxygen index (LOI) (39%), storage modulus (2.4 GPa) at 25℃ and residual carbonization (16.1%) values compared to non-brominated VE. Manual layup of as-prepared VE prepregs with subsequent curing led to the successful fabrication of CF-reinforced composites with high tensile and flexural strength. The results from the study hold high promise for a styrene-free, environmentally friendly VE composite process in the future.

A Hi-Value Process Establishment for Efficient Implement of Design Value Engineering in Highway (효율적 고속도로 설계VE 수행을 위한 Hi-Value 프로세스 정립)

  • Heo, In;Lee, Yong-Gu;Jeong, Byeong-Cheon;Yang, Jae-Gyeong
    • Construction Engineering and Management
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    • v.12 no.6
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    • pp.36-48
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    • 2011
  • 도로건설프로젝트에서의 VE는 도로시설물의 기능을 향상시키고 비용을 절감하기 위한 방법으로 지금까지 널리 활용되고 있다. 그러나, 실제 건설VE 실무에서는 VE Job Plan 중 일부 단계가 생략되거나 형식적으로 수행되는 문제점이 발생되어 VE 수행결과에 대한 신뢰성에 의문이 제기되고 있다. 이는 제조업과 달리 대규모이며 복합공종을 갖는 건설프로젝트의 특성을 반영하지 못하고 있기 때문이다. 건설프로젝트는 대규모 복합공종으로 구성되어 복잡하고 다양한 기능 및 요구성능이 있으며, 시설물이 갖는 기능(Function)과 요구성능(Required Performance)의 일부는 반복적으로 발생하는 특징을 가지고 있다. 이에 본 연구에서는 VE Process의 실효성을 높이기 위하여 품질모델(Quality Model)과 기능분석(Function Analysis)단계에서 이러한 특징을 반영한 개선방향을 제시하고, 수차례 실무 검증을 통하여 적용성 및 효율성을 확인하였다. 이와 더불어 고속도로 VE Job Plan은 고속도로 설계 업무절차에 부합하도록 개선하여 VE 수행효과가 극대화 되도록 제안하였으며, 또한 한국도로공사에서 시행하는 고속도로 대한 VE절차를 "Hi-Value"라 명명하고 실무활용성, 효율성을 확대하고 지속적으로 발전시켜 나아갈 계획이다.

Vitamin E Modulates Radiation-induced Oxidative Damage in Mice Fed a High-Lipid Diet

  • Shin, Sung-Jae
    • BMB Reports
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    • v.36 no.2
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    • pp.190-195
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    • 2003
  • The Vitamin E (VE) effect was examined on oxidative damage to DNA, lipids, and protein in mice that were fed various levels of lipid diets after total body irradiation (TBI) with X-rays at 2 Gy. No increase of 8-hydroxydeoxyguanosine (8OHdG) by TBI was observed in the +VE group; however, in the case of the -VE group, a significantly higher 8OHdG level was observed in the high-lipid group than in the low- or basal-lipid group. In the groups with TBI, the concentration of thiobarbituric reactive substances (TBARS) only significantly increased in the high-lipid (-VE) group. These changes in TBARS, due to TBI, were not detected in other groups. The contents of protein carbonyls only increased in the (-VE) group. The contents of protein carbonyls was significantly different between the (+VE) and the (-VE) groups, regardless of the lipid levels. The concentrations of GSH, vitamins C and E in the liver were lower, and the concentration of non-heme iron in the liver was higher in the high-lipid group than in the low- and basal-lipid groups. These concentrations in the high-lipid group were significantly different between the (+VE) and the (-VE) groups. These results strongly suggest that mice that are fed a high-lipid diet are susceptible to TBI-induced oxidative damage. Also, decreases in the GSH levels and an increase in the iron level are involved in the mechanism of this susceptibility.

Changes in Preference for Grape Seed Oil Dressing according to Mirepoix au Maigre Content Level (Mirepoix Au Maigre 함량 수준에 따른 포도씨유 드레싱의 수용도 변화)

  • Yoo, Seung-Seok;Seo, Min-Suk
    • Korean journal of food and cookery science
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    • v.23 no.5
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    • pp.685-695
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    • 2007
  • The purpose of this study was to develop an excellent salad dressing using grape seed oil, which contains high levels of unsaturated fatty acids. First, a vinaigrette was made with grape seed oil and vinegar and divided into five portions. Then, five types of mirepoix au maigre ($M_1,M_2,M_3,M_4,M_5$) were made with apple, onion, carrot, garlic, tomato puree, and tomato ketchup by mixing in a main material vessel. The samples were then allowed to ripen for three days. The control group $M_1$ was named $GD_1$, and the experimental groups $M_2,\;M_3,\;M_4,\;and\;M_5$ were named $GD_2,\;GD_3,\;GD_4,\;and\;GD_5$. respectively. To measure receptiveness, a sensory test was conducted using a 7 point category scale. The test concentrated on flavor, taste, color, agreeability, aftertaste, and overall acceptability: the panel consisted of 15 subjects According to the results, $GD_4$ had the best flavor, color and agreeability. The samples with the most preferred taste and aftertaste were $GD_4\;and\;GD_5$. Between $GD_4\;and\;GD_5$, there were no noticeable differences in taste, aftertaste, or overall acceptability, but differences in color and agreeability did exist. Thus, $GD_4$ proved to be the most favorable product. To determine the best complementing vegetables for $GD_4$ yam($VE_1$), broccoli sprouts($VE_2$), mustard leaves($VE_3$), beet leaves($VE_4$), cucumber($VE_5$), and lettuce(VE6) were selected as samples, and a sensory test was conducted. Each vegetable has its own peculiarities. According to the results, $VE_2$ had the nicest vegetable fragrance recording the highest mean value. The vegetable with the most preferred taste, aftertaste, and agreeability were $VE_2\;and\;VE_6$. $VE_1\;and\;VE_6$ had the nicest color and contained the brightest color as well. The highest overall acceptability was awarded to $VE_2\;and\;VE_6$ and there was no remarkable difference between thorn at a level of 0.05. In conclusion, $VE_2\;and\;VE_6$ were the best complementing vegetables with grape seed oil dressing. However, to commercialize such a dressing, many follow-up studies must be conducted.

The CO outflow survey toward the Very Low Luminosity Object candidates: a progress report

  • Kim, Gwanjeong;Lee, Chang Won;Kim, Mi-Ryang;Kazuhiro, Kiyokane;Saito, Masao
    • The Bulletin of The Korean Astronomical Society
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    • v.39 no.1
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    • pp.57.1-57.1
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    • 2014
  • We present the preliminary results of CO outflow survey toward the 56 Very Low Luminosity Object (VeLLO) candidates at CO J=2-1 and J=3-2 transitions with two radio telescopes of the Caltech Submillimeter Observatory (CSO) and the Atacama Submillimeter Telescope Experiment (ASTE). The survey is aimed to understand the origin of the formation of low-mass stars or substellar objects. The VeLLO is a very faint (${\leq}0.1$ $L_{\odot}$) object deeply embedded in dense molecular clouds and believed to be a proto-brown dwarf which will be a brown dwarf or a faint protostar which has just formed with little mass accretion or which is in quiescent stage of episodic accretion. The candidates were searched for over all nearby ($d{\leq}450$ pc) Gould belt clouds and listed in a new catalogue of the VeLLO candidates by Kim et al. (2014 submitted). To diagnose present status and future fate of the VeLLOs, we conducted a systematic observation for the CO molecular outflows of the 56 VeLLOs to infer how accretion is being made around the VeLLOs. We found 17 VeLLO candidates either having a prominent wing in line profiles or showing bipolar intensity distribution of high velocity components. We will discuss the physical properties of these CO outflows and the identity of the VeLLO candidates.

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Aerodynamic Characteristics, Vocal Efficiency, and Closed Quotient Differences according to Fundamental Frequency Fixation (음도 고정 유무에 따른 공기역학, 음성효율성 및 성대접촉률 차이)

  • Kim, Jaeock
    • Phonetics and Speech Sciences
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    • v.5 no.1
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    • pp.19-26
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    • 2013
  • The aerodynamic characteristics (subglottal pressure (Ps) and mean airflow rate (MFR)), fundamental frequency (Fo), intensity (I), vocal efficiency (VE), and closed quotient (CQ) were compared during a sustained vowel /o/ sound under three conditions: in a comfortable loudness and pitch level (condition 1), in a maximum loudness level with a fixed pitch (condition 2), and in a maximum loudness level without a fixed pitch (condition 3). Also, multiple regression analyses were done to measure the aerodynamic characteristics affect on the VE and the CQ in each condition. The results showed the Fo, Ps, MFR, VE, and CQ increased as I increased with and without fixed pitch. Most notably, VE in condition 3 was the highest of all the conditions, but CQ was not very high. By the results of multiple regression analysis, VE was significantly affected by I and Ps in all conditions; Fo was the other main key for affecting VE in high pitch. However, none of the aerodynamic characteristics significantly affected CQ. As I increases, Fo should be increased by increasing Ps and VE. Therefore, researchers should consider and specify an a priori to Fo, Ps, and I when measuring VE to examine the complex and delicate vocal mechanism.

An investigation of Function Analysis patterns for the Effective VE at the Design Phase (효과적인 설계VE 활동을 위한 기능분석 유형조사)

  • Min Kyung-Seok
    • Korean Journal of Construction Engineering and Management
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    • v.5 no.6 s.22
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    • pp.63-71
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    • 2004
  • This study is an analysis the function Analysis Patterns for the effective application of VE(Value Engineering) and a presentation of the function analysis methods. 1. The function analysis of VE activities can be summarized 6 patterns as follows ; a generated ideas without function analysis process, a function analysis make use of inspection tools for generated idea, an illogical jump as a using of subjective terms, a using of duplication terms for same functions, a subjective ranking as function definitions for function analysis, and a large classification for a for approaching function definition. 2. In order for the effective function analysis, the process requires as follows; a check level by project advanced, a reclassified main nouns in the order of frequency of use, a main check objects by concepts of importance and satisfaction degree. It is not only good for the effective function analysis, it also induces effective turn out of the FAST Diagram for function arrangement.

Considering Performance Measurement and Life-Cycle Costs for Andong Culture & Art Center BTL Project (VE기법을 적용한 안동문화예술회관 민간투자사업의 성능개선 사례연구)

  • Kim, Seong-Il;Lee, Kwang-Mo;Choi, Seok-Won
    • Proceedings of the Korean Institute Of Construction Engineering and Management
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    • 2007.11a
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    • pp.1005-1010
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    • 2007
  • According to revision of Construction Technology Management Act (2005), the government ordering construction which cost is more than 10billion won should investigate the value engineering(VE) of a construction. In this sense, the government actively promote plans in 2008 after identifying the examining standards of the investigation on the VE(2007). It is substantial issue to introduce Pre-Qualification(PQ) in oder to restrain unlicensed VE consulting companies or VE consultants. This system will contribute to the quality and the settlement of the value engineering in our country. The reason why the Korea VE Society founded in 2006 is one of the afore-mentioned reasons. Therefore, we try to establish the value engineering of Build-Transfer-Lease Scheme by providing the practical application of construction value engineering and definite procedures through the example of Andong Culture and Art Center's research in one of the various construction fields.

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