• Title/Summary/Keyword: Experimental Economics

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Experimental Study on Deformation Resistance Capacity of SY Permanent Steel Form for RC Beam and Girder under Casting Concrete (SY 비탈형 보 거푸집의 콘크리트 타설시 변형저항성능에 관한 실험적 연구)

  • Bae, Kyu-Woong;Shin, Sang-Min
    • Journal of the Korea Institute of Building Construction
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    • v.21 no.6
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    • pp.605-615
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    • 2021
  • Recently, to shorten construction periods and reduce labor costs, the need for a corrugated beam form in the RC structure is being emphasized. The purpose of this study is to evaluate the deformation performance of SY Beam, a newly developed corrugated beam form work, during concrete casting. The standard cross-sectional shape of SY Beam was determined by modeling the deck structure of various thicknesses using the MIDAS GEN program. As a result, the cross-sectional dimensions of the SY Beam were determined to be 400mm and 450mm in width and height, respectively. A total of three SY Beam specimens were fabricated using steel plate thicknesses of 0.8, 1.0, and 1.2mm. The load conditions applied during casting concrete at the actual site are reflected. The vertical and horizontal displacements of the SY beam were measured during concrete casting. As a result, the vertical displacement showed a tendency to decrease as the thickness increased. Considering both vertical and horizontal displacement, the case with steel plate thickness of 1.2mm is the safest and most immediately applicable to the field. In the future, to secure manufacturability, constructability, and economics, the optimum steel plate thickness should be derived, and additional analysis and experimental studies for 1.05, 1.1, and 1.15mm are required.

Estimating the Impact of Plant Surface Area Increase and Physiological Activities on Fine Dust Purification (식물에 의한 표면적 증가와 생리작용이 미세먼지 정화에 미치는 영향 추정)

  • Deuk-Kyun Oh;Sung-Soo Lim;Jeong-Ho Kim
    • Korean Journal of Environment and Ecology
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    • v.38 no.4
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    • pp.426-433
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    • 2024
  • In this study, to estimate the effects of plant-induced surface area increase and physiological activity on fine dust purification, a control group was set up. We utilized both foliage plants (Spathiphyllum wallisii) and artificial plants (shaped like Spathiphyllum wallisii) to measure and compare the purification time for fine dust. The results showed that the time required for fine dust purification in each experimental group decreased by 57-64% for Type AP and 31-32% for Type P compared to the control group. Subsequently, using a Linear Mixed Model (LMM), we tested the interaction between time and each experimental group, revealing statistically significant interactions between surface area increase and time(PM10 : t=3.123, p<0.05, PM2.5 : t=3.180, p<0.05), as well as physiological activity and time(PM10 : t=4.065, p<0.05, PM2.5 : t=4.307, p<0.05), indicating the presence of interactions between each factor and the time variable. Finally, we estimated the efficiency of fine dust purification by plant factors through nonlinear regression analysis. Compared to the control group without purification factors (Type C), it was estimated that surface area increase shortened the purification time by 1.40 times and physiological activity by an average of 1.95 times, resulting in a total 2.74 times shorter purification time. Based on these results, we hypothesized that physiological activity(transpiration and absorption) has a greater impact on fine dust purification than surface area increase(biosorption). Accordingly, we emphasize the importance of vegetation management practices such as pruning and irrigation management in green spaces aimed at fine dust purification.

Effects of Conjugated Double Bond Derivatives of Polyunsaturated Fatty Acid on Serum Lipids in Rats (다가불포화지방산의 공역이중결합 유도체가 흰쥐의 혈청 지질 성분에 미치는 영향)

  • Kim, So-Young;Kim, Sung-Hee;Kim, Gyeong-Eup
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.36 no.9
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    • pp.1120-1127
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    • 2007
  • This study was designed to examine the effects of n-6 PUFA rich corn oil, n-3 PUFA rich perilla oil and their conjugated double bond derivatives on serum lipids status in rats. Experimental diets containing lard (control), corn oil (CO), perilla oil (PO), conjugated double bond derivatives of n-6 PUFA rich corn oil (TCO) and n-3 PUFA rich perilla oil (TPO) at the level of 10% (w/w) were fed to male Sprague Dawley rats for 4 weeks. TCO was found to have three derivatives of linoleic acid and TPO had five derivatives of linolenic acid by GC. Serum total cholesterol levels were significantly lower in the all experimental groups than in the control group, and particularly, the lowest in TCO and TPO groups. HDL-cholesterol concentrations were a little higher in the all experimental groups than in the control group, and TCO and TPO groups were not significantly different from CO and PO groups. Serum LDL, LDL-cholesterol, chylomicron and triglyceride concentrations were significantly lower in the all experimental groups than in the control group, remarkably lower in TCO group and particularly, the lowest in the TPO group. Serum free cholesterol and cholesteryl ester concentrations were lower in TCO and TPO groups than in CO and PO groups. From the above research, TCO and TPO groups were effective on the improvement of the lipid compositions in serum and particularly, TPO group was the most effective on the improvement of serum lipids.

Effects of Hot Water Soluble Extract from Green Tea on the Lipid Metabolism and Antioxidant Effect in Rats fed Animal or Vegetable Protein and a Hypercholesterol Diet (녹차 열수추출물이 동$\cdot$식물성 단백질과 고콜레스테롤을 급여한 흰쥐의 지질대사와 항산화효과에 미치는 영향)

  • Won, Hyang-Rye;Rhie, Seung-Gyo;Park, Dong-Yean
    • The Korean Journal of Community Living Science
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    • v.16 no.4
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    • pp.39-45
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    • 2005
  • The aim of this study is to investigate the effects of hot water soluble extract from green tea on the components of serum and the liver and the antioxidative effects in accordance with the different protein types. For this purpose, four experimental groups were set up. As for the protein source casein, isolated soy protein was supplemented to the rats, together with hot water soluble extract from green tea. Four experimental groups kept eight Sprague-Dawley rats respectively. The CP group was supplemented with casein only, the CG group was supplemented with casein and hot water soluble extract from green tea, the ISP group was supplemented with isolated soy protein only, and the ISG group was supplemented with the isolated soy protein with hot water soluble extract from green tea. After 4 weeks of feeding with experimental diet, the levels of serum and liver lipid and antioxidant enzyme activity and TBARS in the liver were measured. The results are; 1. Weight gain and FER were higher in the casein group than in the isolated soy protein group in general. In the casein group, the weight gain and FER were reduced significantly when hot water soluble extract from green tea was supplemented (P < 0.05). There was no significant difference in feed intake. 2. In general, total cholesterol and LDL-cholesterol in the serum were higher in the casein group than in the isolated soy protein group, however just the concentration of LDL-cholesterol in the casein group was significantly lower when the hot water soluble extract from green tea was supplemented (P < 0.05). 3. Triglycerides in the liver were higher in the casein group than in the isolated soy protein group general, however when hot water soluble extract from green teas was supplemented only in the isolated soy protein group, the content of triglyceride in liver was significantly lower (P < 0.05). 4. There was no significant difference in antioxidant enzyme activity in the liver in all the groups, however the content of TBARS was low only in the casein group when hot water soluble extract from green tea was supplemented (P < 0.05).

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An Analysis of Consumers' Socio-Cultural Experiences Expressed in Consumption Stories : An Experimental Application of a Narrative Analysis (소비생활 이야기에 반영된 소비자의 사회문화적 경험 분석: Narrative 분석의 실험적 적용)

  • Kim, Kee-Ok
    • Journal of the Korean Home Economics Association
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    • v.37 no.5
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    • pp.61-84
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    • 1999
  • The purpose of this study is to understand the context of cosumers' lives in Korea with a narrative analysis method. The epistemological orientation of eh narrative analysis is Interpretivism, which blends the two polar philosophical perspectives, Empiricism and Rationalism, and includes Narrotology, Hermeneneutics, Semiotics, and Structural Criticism. Narrative analysis takes as its object of investigation the story itself. This study collects eleven narrative plots from four housewives, into which Labov's structural approach is applied. This study shows clearly that the socio-cultural environment in which consumers live has strong influence on their consumption behavior and also reveals that narrativization tells not only about past actions but how individuals understand those actions, that is, meaning.

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A Experimental Study on the Structural Performance of Column Spliceswith Metal Touch Subjected to Axial Force and Bending Moment (압축력과 휨모멘트를 받는 메탈 터치된 기둥 이음부의 구조성능에 대한 실험적 연구)

  • Hong, Kap Pyo;Kim, Seok Koo;Lee, Joong Won
    • Journal of Korean Society of Steel Construction
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    • v.20 no.5
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    • pp.633-644
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    • 2008
  • The structural framework design uses high-strength bolts and welding in column splices. However, for the column under high compression, the number of the required high-strength bolts can be excessive and the increase of welding results in difficulty of quality inspection, the transformation of the structural steels, and the increase of erection time. According to the AISC criteria, when columns have bearing plates, or they are finished to bear at splices, there shall be sufficient connections to hold all parts securely in place. The Korean standard sets the maximum 25% of the load as criteria. Using direct contact makes it possible to transfer all compressive force through it. The objective of this study is to examine the generally applied stress path mechanism of welded or bolted columns and to verify the bending moment and compression transfer mechanism of the column splice according to metal touch precision. For this study,22 specimens of various geometric shapes were constructed according to the change in the variables for each column splice type, which includes the splice method, gap width, gap axis, presence or absence of splice material, and connector type. The results show that the application of each splice can be improved through the examination of the stress path mechanism upon metal contact. Moreover, the revision of the relative local code on direct contact needs to be reviewed properly for the economics and efficiency of the splices.

The study on the social network service quality of companies in Mobile Environment -focusing on the difference of recognition depending on the level of commitment and loyalty- (모바일 환경에서 기업의 소셜네트워크 서비스 품질에 관한 연구 -몰입 및 충성도에 따른 집단간 인식차이를 중심으로-)

  • Kim, Sang-Hyuck;Yang, Jae-Hoon
    • International Commerce and Information Review
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    • v.14 no.3
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    • pp.539-558
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    • 2012
  • The purpose of this study is examining the differences of mobile SNS's service quality, which consists data quality and system quality, among the groups that are classified by commitment and customer loyalty. For the experimental analysis, the frequency analysis was performed for general characteristics of sample. The variables were selected by factor analysis that also prove the validity of variables. The value of Cronbach's alpha was calculated to check the reliability of variables. In addition, the group was determined by the both hierarchical and hierarchical cluster analysis, then ANOVA was performed to test the hypotheses that there are differences of mobile SNS's service quality, among the groups that are classified by commitment and customer loyalty. The results of this study support that there are differences among the groups toward mobile SNS's service quality and also shows the more commitment and loyalty group is the higher recognition of mobile SNS's service quality. Thus, the companies have to realize that mobile SNS is very important key factor to success in rapidly changing business environment. In conclusion, the companies implement different customized strategy for the different group and develop the contents and the applications to maximize the commitment and loyalty of for the mobile SNS users.

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Properties of Alkali-Activated Cement Mortar by Curing Method (양생 방법에 따른 알칼리활성 시멘트 모르타르의 특성)

  • Kim, Ji-Hoon;Lee, Jae-Kyu;Hyung, Won-Gil
    • Journal of the Korea Concrete Institute
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    • v.26 no.2
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    • pp.117-124
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    • 2014
  • Globally, there are environmental problems due to greenhouse gas emissions. $CO_2$ emissions rate of the cement industry is very high, but the continued demand of cement is needed in the future. In this study, in order to reduce the environmental impact of $CO_2$ emissions from cement production. The experiments were carried out for the development of non-sintered cement (have not undergone firing burning) by granulated ground blast furnace slag. In order to compare the characteristics by curing, an experiment was conducted by changing the curing conditions such as atmospheric steam curing, observe the mechanical properties for the measurement of flexural compressive strength by mortar, observe the chemical properties such as acid resistance, $Cl^-$ penetrate resistance and analyzed the mechanism of hydration by XRD, SEM experiments. From the experimental results, as compared with portland cement usually confirm the mechanical and chemical properties excellent, it is expected be possible to apply to the undersea, underwater and underground structures that require superior durability. In addition, based on the excellent compressive strength by steam curing, it is expected to be possible to utilize as a cement replacement material in the secondary product of concrete. In the future, to solve the problem through continued research, it will be expected to reduce the effect of environmental load and to be excellent economics.

Estimation in a Model for Determining the Amount of Carbon in Soil and Measurement of the Influences of the Specific Factors (농경지 토양탄소량 결정모형 추정 및 요인별 영향력 계측)

  • Suh, Jeong-Min;Cho, Jae-Hwan;Son, Beung-Gu;Kang, Jum-Soon;Hong, Chang-Oh;Kim, Woon-Won;Park, Jeong-Ho;Lim, Woo-Taik;Jin, Kyung-Ho
    • Journal of Environmental Science International
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    • v.23 no.11
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    • pp.1827-1833
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    • 2014
  • This study has been carried out to present the valuation system of soil carbon sequestration potentials of soil in accordance with the new climate change scenarios(RCP). For that, by analyzing variation of soil carbon of the each type of agricultural land use, it aims to develop technology to increase the amount of carbon emissions and sequestration. Among the factors which affects the estimation of determining the soil carbon model and influence power after the measurement on soil organic carbon, under the center of a causal relationship between the explanatory variables this study were investigated. Chemical fertilizers (NPK) decreased with increasing the amount of soil organic carbon and as with the first experimental results, when cultivating rice than pepper, the fact that soil organic carbon content increased has been found out. The higher the carbon dioxide concentration, the higher the amount of organic carbon in the soil and this result is reliable under a 10% significance level. On the other hand, soil organic carbon, humus carbon and hot water extractable carbon has been found out that was not affected the soils depth, sames as the result of the first year. The higher concentration of carbon dioxide, the higher carbon content of humus and hot water extractable carbon content. According to IPCC 2006 Guidelines and the new climate change scenario RCP 4.5 and the measurement results of the total amount of soil organic carbon to the crops due to abnormal climate weather, 1% increase in atmospheric carbon dioxide concentration was found to be small when compared to the growing rate of increasing 0.01058% of organic carbon in the soil.

An Experimental Method of Calcium Absorption in Rat Small Intestine - in situ Closed Gut Segment Technique - (장관내(腸管內) 칼슘흡수 실험방법에 관한 연구)

  • Lee, Yeon Sook
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.12 no.1
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    • pp.41-45
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    • 1983
  • The method of intestinal Ca absorption in rats was studied by injecting the test solution of $^{45}Ca$ into ligated ileal loops (an in situ closed gut sement technique). The amount of Ca absorbed was measured in regard to the amount of soluble $^{40}Ca$ and $^{45}Ca$ which disappeared from the ligated ileal loops for 30min, and appeared portal blood for 15 min after the injection. The 15~20cm ligated segment of mid ileum and the test solution containing $0.2{\sim}0.5{\mu}Ci$ $5{\mu}g$ Ca/0.5ml, pH 7.0, $37^{\circ}C$ are appropriate for this in situ closed gut segment technique which turn out to be highly available for study of Ca absorption. The rats fed casein diet absorbed more Ca by 2~5 times than the rats fed egg albumin diet.

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