• 제목/요약/키워드: Strength Note

검색결과 65건 처리시간 0.024초

A Note on Association for Korean Markets Using Correspondence Analysis

  • Jeong, Dong-Bin
    • 산경연구논집
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    • 제7권3호
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    • pp.5-12
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    • 2016
  • Purpose - In this paper, we consider more segmented types of markets than conventional version of ones in South Korea and explore the degree of relations between these markets and the related factors with them. In this case, ten attributes of types of markets mentioned above will be considered. To be more specific, the numerical strength is evaluated and graphical approach is expressed on two-dimensional plane, if the association exists between the considered variables. Research design, data, and methodology - This work is done by the 2013 report on the commercial building lease offered by Small Businessmen Promotion Institute (May/2013~August/2013) and exploited by statistical analyses such as correspondence analysis and a chi-squared test in IBM SPSS 23.0. Results - Findings of this paper indicate that a variable Korean market, including traditional markets, are closely connected with variables administrative district, sales and occupation instead of company, age group and business duration and the detailed associations between variables can be obtained by inspecting results of correspondence analysis. Conclusions - We can understand where the status of the Korean markets stands now through this work and also government authority and local autonomy can take advantage of these findings to enhance the revitalization of Korean markets and other markets.

Physical Properties of Gelidium corneum Films Treated with Cinnamaldehyde - Research Note -

  • Ku, Kyoung-Ju;Seo, Yung-Bum;Song, Kyung-Bin
    • Preventive Nutrition and Food Science
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    • 제12권2호
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    • pp.122-125
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    • 2007
  • Gelidium corneum films were prepared using cinnamaldehyde as a cross-linking agent and their physical properties were determined. Tensile strength (TS) value of the film containing 0.01% cinnamaldehyde was higher than the control by 8.31 MPa. However, increasing cinnamaldehyde from 0.01% to 0.1% significantly decreased TS from 9.54 MPa to 0.03 MPa, and no film was formed at 1% cinnamaldehyde. On the contrary, when cinnamaldehyde content was increased from 0.01% to 0.1%, % elongation was increased from 1.44% to 2.75%. Water vapor permeability (WVP) of the film containing 0% and 0.01% cinnamaldehyde were 1.64 ng m/m$^2$sPa and 1.42 ng m/m$^2$sPa, respectively. There was no significant difference in Hunter values among treatments. Scanning electron microscopy results revealed that both cinnamaldehyde and control films had similar surfaces. These results suggest that 1.5% Gelidium corneum treated with 0.01% cinnamaldehyde should be the most suitable condition for film formation.

Seismic vibration control of bridges with excessive isolator displacement

  • Roy, Bijan K.;Chakraborty, Subrata;Mishra, Sudib K.
    • Earthquakes and Structures
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    • 제10권6호
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    • pp.1451-1465
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    • 2016
  • The effectiveness of base isolation (BI) systems for mitigation of seismic vibration of bridges have been extensively studied in the past. It is well established in those studies that the performance of BI system is largely dependent on the characteristics of isolator yield strength. For optimum design of such systems, normally a standard nonlinear optimization problem is formulated to minimize the maximum response of the structure, referred as Stochastic Structural Optimization (SSO). The SSO of BI system is usually performed with reference to a problem of unconstrained optimization without imposing any restriction on the maximum isolator displacement. In this regard it is important to note that the isolator displacement should not be arbitrarily large to fulfil the serviceability requirements and to avoid the possibility of pounding to the adjacent units. The present study is intended to incorporate the effect of excessive isolator displacement in optimizing BI system to control seismic vibration effect of bridges. In doing so, the necessary stochastic response of the isolated bridge needs to be optimized is obtained in the framework of statistical linearization of the related nonlinear random vibration problem. A simply supported bridge is taken up to elucidate the effect of constraint condition on optimum design and overall performance of the isolated bridge compared to that of obtained by the conventional unconstrained optimization approach.

FPSO 선의 PAU SEAT 강도 해석 (Strength Analysis for PAU Seat of FPSO)

  • 하태민;김성수;송명근
    • 대한조선학회 특별논문집
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    • 대한조선학회 2005년도 특별논문집
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    • pp.90-96
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    • 2005
  • This paper presents the results of the reliability analysis of PAU (Preliminary Assembly Unit) seat of the floating Production Storage and Off1-loading Unit (FPSO) The main aim of the analysis was to demonstrate that a sufficient safety of structural members is guaranteed against PAU loads, internal and external pressure, and hull girder moments. Topside loads for PAU design are based on owner's request. According to the seat type, topside loads are classified into maximum values of same seat type for design efficiency. Totally, 26 loading cases for each model are used for this analysis with the combination of the reactions of PAU loafing and the hull girder bending moments according to LR offshore (2). The analysis results are evaluated according to the acceptance criteria for yielding given in LR offshore and guidance note (3) and The panel buckling resistance is verified by LR offshore and SDA (4). For 900,000 bbls FPSO, the PAU support foundation analysis using 3-D F.E. model is carried out to verify the structural adequacy of PAU foundation and structure members in way of PAU. The modified structures in way of PAU support are safe against considered load cases and all stresses in way of PAU support are within design criteria.

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허약한 노인을 위한 고유수용성 신경근 촉진법과 타이치의 적용에 관한 고찰 (Review of the approach in the PNF and Tai Chi on frail elders)

  • 조정선;배성수;박래준
    • PNF and Movement
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    • 제5권1호
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    • pp.29-35
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    • 2007
  • Purpose : The purpose of this study was investigated to find the approach in the PNF and TC for frail elder Method : This is a literature study with books, articles, seminal note and books for PNF and TC international course. Result : Neural mechanisms contribute significantly to the gains that occur in the range of motion about a joint with stretching exercises. The participation in a stretch-training program decreases tonic reflex activity and increases flexibility and decreases in force production and muscle activation. Also the stretching-induced decreases may be due to a central nervous system inhibitory mechanism. PNF stretch techniques can increase ROM in older adults. These results may differ from those of studies performed with younger populations because of age-related physiologic changes. TC exercise improves balance control and muscle strength and were associated with reorganized lower extremity neuromuscular patterns. Conclusions : The stretch training program of the PNF and TC contribute to increase the balance and coordination for frail elder. Therefore, The frail elder prevent falling. Further study, The PNF and TC be introduced as the new therapeutic intervention for frail elder.

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Studies on structural interaction and performance of cement composite using Molecular Dynamics

  • Sindu, B.S.;Alex, Aleena;Sasmal, Saptarshi
    • Advances in Computational Design
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    • 제3권2호
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    • pp.147-163
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    • 2018
  • Cementitious composites are multiphase heterogeneous materials with distinct dissimilarity in strength under compression and tension (high under compression and very low under tension). At macro scale, the phenomenon can be well-explained as the material contains physical heterogeneity and pores. But, it is interesting to note that this dissimilarity initiates at molecular level where there is no heterogeneity. In this regard, molecular dynamics based computational investigations are carried out on cement clinkers and calcium silicate hydrate (C-S-H) under tension and compression to trace out the origin of dissimilarity. In the study, effect of strain rate, size of computational volume and presence of un-structured atoms on the obtained response is also investigated. It is identified that certain type of molecular interactions and the molecular structural parameters are responsible for causing the dissimilarity in behavior. Hence, the judiciously modified or tailored molecular structure would not only be able to reduce the extent of dissimilarity, it would also be capable of incorporating the desired properties in heterogeneous composites. The findings of this study would facilitate to take step to scientifically alter the structure of cementitious composites to attain the desired mechanical properties.

다구찌 기법을 적용한 강의만족도 향상 사례 연구 (A Study on Improving Lecture Satisfaction using Taguchi Method)

  • 이상복
    • 품질경영학회지
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    • 제42권1호
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    • pp.63-70
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    • 2014
  • Purpose: This article introduces a case study of using Taguchi Method to improve lecture satisfaction. Developed by Taguchi Genichi, this method has its strength in finding the control factor that is robust against noise factor. Finding the condition for such control factor has an effect of reducing the dispersion of the Lecture satisfaction. Methods: There are various factors in university classrooms. The factors which influenced the Lecture Satisfaction are analyzed by control factors and noise factors, control factors which is controllable are lecture completeness and thoroughly test the degree of supervision and noise factors which is not controllable is degree of physical and psychological Lecturer tired, then the experiment is conducted as guided by Taguchi's experimental design, one semester are experimented by eight professor with 2 classes, after discussion of the results the optimal lecture condition is suggested. Results: To improve Lecture Satisfaction under noise factor of physical and psychological Lecturer tired, optimal condition are that lecture completeness have scenario note during lecture and thoroughly test the degree of supervision have two proctors during test. Conclusion: In this paper, we have succession case by applying Taguchi methods in Lecture Satisfaction. We can apply to improve service by applying the Taguchi methods. In the future we hope to have many succession cases.

정삼투 멤브레인 공정에서 칼슘이온과 용존 유기물 상호작용에 의한 플럭스 변화 연구 (Systematic study on calcium-dissolved organic matter interaction in a forward osmosis membrane-filtration system)

  • 허지용;한종훈;김예진;허남국
    • 상하수도학회지
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    • 제30권6호
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    • pp.737-744
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    • 2016
  • The investigation of effects on fouling propensity with various viscosity of feed solutions would be better understanding for forward osmosis (FO) performance since the fouling propensity was directly influenced with solution viscosity. Therefore, this study was focused on the FO fouling with model foultants (humic acid, alginate) by altering solution viscosity with change of ionic strength (I.S) and $Ca^{2+}$ concentrations. In the comparison between humic acid and alginate, as expected, the alginate generally caused more severe fouling (almost 35.8 % of flux reduction) based on the solution characteristics (high viscosity) and fouling patterns (coil and gel layer). However, interesting point to note is that the fouling propensity of alginate was more severe even though it was applied with low viscosity of feed conditions (I.S = 20 mM, $Ca^{2+}=1mM$). This might be due to that crossed linked gel layer of alginate on the FO membrane surface could be best formed in the condition of $Ca^{2+}$ presence and higher I.S, and that is more dominant to fouling propensity than the low viscosity of feed solutions.

Entropy, enthalpy, and gibbs free energy variations of 133Cs via CO2-activated carbon filter and ferric ferrocyanide hybrid composites

  • Lee, Joon Hyuk;Suh, Dong Hack
    • Nuclear Engineering and Technology
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    • 제53권11호
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    • pp.3711-3716
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    • 2021
  • The addition of ferric ferrocyanide (Prussian blue; PB) to adsorbents could enhance the adsorption performance of 133Cs. Toward this goal, we present a heterogeneously integrated carbonaceous material platform consisting of PB in direct contact with CO2-activated carbon filters (PB-CACF). The resulted sample retains 24.39% more PB than vice versa probed by the ultraviolet-visible spectrometer. We leverage this effect to capture 133Cs in the aqueous environment via the increase in ionic strength and micropores. We note that the amount of PB was likely to be the key factor for 133Cs adsorption compared with specific surface characteristics. The revealed adsorption capacity of PB-CACF was 21.69% higher than the bare support. The adsorption characteristics were feasible and spontaneous. Positive values of 𝜟Ho and 𝜟So show the endothermic nature and increased randomness. Based on the concept of capturing hazardous materials via hazardous materials, our work will be of interest within the relevant academia for collecting radionuclides in a sufficient manner.

경량기포모르터와 합성한 경량형강 벽체의 전단 저항 (Shear Resistance of Light-gauge Steel Stud Wall infilled with light-weight foamed mortar)

  • 이상섭;배규웅
    • 한국강구조학회 논문집
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    • 제16권4호통권71호
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    • pp.397-406
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    • 2004
  • 본 논문은 경량형강으로 제작한 프레임에 경량기포모르터를 채운 경량합성벽체의 전단 거동에 대한 실험 결과와 전단 강도 및 강성 평가를 제시한 것이다. 경량기포모르터는 스틸하우스 벽체의 구조 성능 및 단열 성능의 향상과 마감에 대한 시공성 개선을 위해 도입되었다. 연구 결과 단열 성능에 대한 기여도는 낮으나, 경량기포모르터의 슬러리 비중이 0.8 이상인 경우 구조 성능의 향상과 마감성이 좋은 것으로 나타났다. 본 연구에서는 전단 거동에 미치는 경량기포모르터의 영향을 알아보기 위해 경량기포모르터의 비중(0.6, 0.8, 1.0, 1.2) 벽체의 스터드 배치간격(450mm, 600mm, 900mm), 마감재(경량기포모르터, OSB, 석고보드) 및 브레이싱 등을 변수로 한 14개의 경량합성벽체를 제작하였고 비교를 위해 대표적인 스틸하우스 벽체 3개를 제작하였다. 면내전단 실험결과, 경량기포모르터를 타설한 경량합성벽체가 기존의 스틸스터드 벽체에 비해 최대 내력은 1.15~5.38배, 초기강성은 1.45~13.7배 증가한 것으로 나타났다. 또한 벽체 내부의 스터드를 900mm까지 확장하여도 무리가 없는 것으로 나타났다. 그러나 이와 같은 결과는 건조수축 균열이 억제되지 않은 상태에서 나온 것으로 경량합성벽체의 내력을 향상시키기 위해서는 경량기포모르터의 초기 건조수축균열을 억제하고 스터드와 경량기포모르터 사이의 부착력을 확보하는 것이 무엇보다도 중요한 것으로 나타났다.