• Magazine of the Korea Concrete Institute
• /
• v.11 no.1
• /
• pp.149-160
• /
• 1999

This paper is a part of a research aimed at the verification of basic design rules of high-strength concrete columns. A total of 32 column specimens were tested to investigate structural behavior and strength of eccentrically loaded reinforced concrete tied columns. Main variables included in this test program were concrete compressive strength. steel amount, eccentricity, and slenderness ratio. The concrete compressive strength varied from 356 kg/$cm^2$ to 951 kg/$cm^2$ and the longitudinal steel ratios were between 1.13 % and 5.51 %. Test results of column sectional strength are compared with the results of analyses by ACI rectangular stress block, trapezoidal stress block, and modified rectangular stress block. Axial force-moment-curvature analysis is also performed for predicting axial load-moment strength and compared with the test results. The ACI rectangular stress block provides over-estimated column strengths for the lightly reinforced high strength column specimens. The calculated strengths by moment-curvature analyses are highly affected by $k_3$ values of the concrete stress-strain curve. Observed failure mode. concrete ultimate strain, and stress block parameters are discussed.

• Journal of the Korean GEO-environmental Society
• /
• v.10 no.7
• /
• pp.7-14
• /
• 2009

The correlation equation empirically proposed to obtain compression indexes has been proposed to conveniently obtain the value using the soil parameter that can be obtained through simple tests when the number of time of consolidation testing is low or the distribution is large but most of the analyzed regions are limited to certain regions abroad or in the country and multiple data were integrated for use in many cases, thus it is not very reasonable to apply it. Therefore, to establish a new design method considering the uncertainty of the ground, it was selected the Kwangyang port area of which the data have been collected recently thus are relatively more reliable as the subject region of the study in order to maximally reduce the uncertainty of test data. After performing the verification of the normality of the consolidation test data obtained from the selected region and the transformation of variables, a prediction formula was proposed through the regression model with the transformed variables and the proposed regression model with transformed variables was compared with existing empirical equations to verify the suitability of the proposed model formula. After analyzing, it was confirmed that the coefficient of determination was increased after the Box-Cox variable transformation, thus the explanatory power was being enhanced and through the root-mean-square-error method, it was confirmed that the proposed model formula showed the most closed value to the test value.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
• /
• v.4 no.4
• /
• pp.1-25
• /
• 2009

The Government is putting efforts to enhance efficiency and productivity of performances of National R&D Programs by enacting 'Law on Evaluation and Management of Performances of National R&D Program'. This study is the result of development of evaluation model and indices for analysis of efficiency through meta evaluation method for the specific evaluation among evaluation systems for National R&D Program that are being carried out at government-wide level. Meta evaluation model for analysis of efficiency of evaluation system for National R&D Program designed evaluation indices by categorizing compositional factors into 5 categories, namely, evaluation context factor, evaluation resources factor, evaluation process factor, evaluation result factor and evaluation utilization factor. Furthermore, the result of verification of reliability on evaluation composition factors and evaluation indices analyzed to select evaluation items displayed Cronbach' $\alpha$ coefficient of 0.933, thereby illustrating that there is no major problem in the evaluation index system. In addition, computation of weight for each evaluation composition factor and evaluation index was analyzed by using analytical hierarchy process (AHP) technique. The result of analysis displayed overall consistency index of less than 0.1 for the investigators, thereby enabling analysis that there is consistency in investigators.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.33 no.3
• /
• pp.1123-1130
• /
• 2013

This paper aims to estimate work zone base capacity by the number of lanes for urban freeway. To do this, data were collected from the field survey and the database system maintained by traffic control center, and analyzed with four different methods such as the average maximum observation flow rate, headway, regression analysis, and parameter inspection. The work zone base capacity for urban freeway is estimated based on the average maximum observation flow rate and headway method, which are more reliable methods compared to others. The average capacity is 1,650pcphpl when the design speed is 80km/h. The capacity of four lanes one-way work zones was about 1,700pcphpl, while one of 2 lanes one-way work zones was about 1,600pcphpl. The capacity reduction rates for each are 0.15 and 0.2, respectively. The smaller the number of lane is, the more base capacity is reduced. For verification of results, we estimate the capacity by simulation analysis using PARAMICS, and compare with analytical results by a statistical method. This research can be used for efficient and systemic management of work zone in the urban freeway.

• The Journal of Industrial Distribution & Business
• /
• v.8 no.4
• /
• pp.47-52
• /
• 2017

Purpose - This current study will investigate the average financial ratio of top and failed five-star hotels in the Jeju area. A total of 14 financial ratio variables are utilized. This study aims to; first, assess financial ratio of the first-class hotels in Jeju to establishing variables, second, develop distress prediction model for the first-class hotels in Jeju district by using logit analysis and third, evaluate distress prediction capacity for the first-class hotels in Jeju district by using logit analysis. Research design, data, and methodology - The sample was collected from year 2015 and 14 financial ratios of 12 first-class hotels in Jeju district. The results from the samples were analyzed by t-test, and the independent variables were chosen. This was an empirical study where the distress prediction model was evaluated by logit analysis. This current research has focused on critically analyzing and differentiating between the top and failed hotels in the Jeju area by utilizing the 14 financial ratio variables. Results - The verification result of the accuracy estimated by logit analysis has shown to indicate that the distress prediction model's distress prediction capacity was 83.3%. In order to extract the factors that differentiated the top hotels in the Jeju area from the failed hotels among the 14 chosen, the analysis of t-black was utilized by independent variables. Logit analysis was also used in this study. As a result, it was observed that 5 variables were statistically significant and are included in the logit analysis for discernment of top and failed hotels in the Jeju area. Conclusions - The distress prediction press' prediction capability was compared in this research analysis. The distress prediction press prediction capability was shown to range from 75-85% by logit analysis from a previous study. In this current research, the study's prediction capacity was shown to be 83.33%. It was considered a high number and was found to belong to the range of the previous study's prediction capacity range. From a practical perspective, the capacity of the assessment of the distress prediction model in the top and failed hotels in the Jeju area was considered to be a prominent factor in applications of future hotel appraisal.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.19 no.6
• /
• pp.664-668
• /
• 2018

Free-standing structures that are especially high are more likely to receive brain attacks caused by lightning. Since special structures are generally part of national industrial structures, lightning strikes mostly cause socio-economic damage. Lightning protection facilities are installed to prevent such lightning damage, but in 2015, support cables on West Sea bridges were hit by lightning, causing a lot of economic damage. Accordingly, the design of a lightning protection system shall establish protective measures after analyzing the risk of debris falling onto the structure. In this thesis, lightning strikes are analyzed directly in relation to the modeling system that operates the actual information collection system for lightning strikes, depending on the location of the tall, free-standing structures, and practical lightning hazard information is provided by a meteorological station. In addition, we propose monitoring and applying a probability correction rate to the calculation of the lightning risk based on the number of lightning strikes directly reaching the ground in order to obtain an effective lightning risk assessment.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.21 no.10
• /
• pp.461-470
• /
• 2020

This study analyzed the determinants of land compensation costs using the CALS (Continuous Acquisition & Life-Cycle Support) system to generate data for the construction (planning, design, building, management) process. For analysis, variables used in the related research on land costs were used, which included eight variables (Land Area, Individual Public Land Price, Appraisal & Assessment, Land Category, Use District 1, Terrain Elevation, Terrain Shape, and Road). Also, the variables were analyzed using the machine learning-based Xgboost algorithm. Individual Public Land Price was identified as the most important variable in determining land cost. We used a linear multiple regression analysis to verify the determinants of land compensation. For this verification, the dependent variable included was the Individual Public Land Price, and the independent variables were the numeric variable (Land Area) and factor variables (Land Category, Use District 1, Terrain Elevation, Terrain Shape, Road). This study found that the significant variables were Land Category, Use District 1, and Road.

• Korean Journal of Human Ecology
• /
• v.17 no.6
• /
• pp.1225-1236
• /
• 2008

The purpose of this study is to determine the effect of aromatherapy, showing how the composition handling of aromatherapy and abdominal massage treatment reaches body ingredient transformation. The subjects for this research were total 18 middle-aged females in Seoul; aroma massage group of 7 females, aroma inhalation and water bathe group of 5 females, abdominal massage group of 6 females by jojoba oil without any medical effect. This clinic trial was held from July 1, 2008 to Aug.14, 2008. I held this clinic trial under the same condition after and before this clinic. A standard tape and OLYMPIA 3.5 of S hospital were used at the body measuring for subjects after and before clinic trials. I got Average and standard deviation by data analysis by SPSS Win. Ver.14.0. I did paired t-test for the comparison of before and after, and repeated measure ANOVA for between two groups or among three groups'. The verification was held Duncan Test. The results of this study were as follows: 1. Body mass quotient (F=2.86, p= .063) and Body region (F=1.34, p= .279) among three groups showed no meaningful difference, but weight meaningful difference and aroma massage group showed the greatest difference of body measure change quantity. 2. In change quantity of abdomen girth, Waist circumference and WHR, abdomen girth (F=4.56, p= .012) and Waist circumference (F=4.37, p= .031) showed a meaningful statistical difference. The result of subsequent inspection showed that there was a meaningful difference among three groups and aroma massage group was best. 3. In Cell quantity, Body region quantity and Muscle volume, Body region quantity (F=2.76, p= .182) and Muscle volume (F=3.12, p= .054) showed no difference, but Cell quantity (F=3.79, p= .040) showed a meaningful difference. In the comparison of three groups there was no difference, but aromatherapy group showed more change quantity than any other group. According to the result of this study, the composition handling of aromatherapy and body massage was effective in the decrease of Abdominal fatness and Waist circumference, Weight and the increase of Cell quantity. so I suggest that woman use this therapy in the program of obesity management for her health improvement.

• Journal of Korea Multimedia Society
• /
• v.9 no.11
• /
• pp.1503-1514
• /
• 2006

Today, consumers can access Internet from everywhere, therefore most commercial and other organizations provide their services on the Web. As the result, countless Web service systems are already on the Internet and more systems are under construction. Therefore, many researches of verifying that the system to be constructed will not have any deadlock and will run successfully without any problem at the early stage of design have been performed. Several Petri net based verification methods have also been published. However, they have focused on building Petri net models of Web service systems and none of them introduces efficient analysis methods. As a mathematical technique with which we can find the minimum duration time needed to fire all the transitions at least once and coming back to the initial marking in a timed net, the minimum cycle time method has been widely used in computer system analysis. A timed net is a modified version of a Petri net where a transition is associated with a delay time. A delay time used in a timed net is a constant even though the duration time associated with an event in the real world is a stochastic number in general. Therefore, this paper proposes 'Mixedly Distributed Stochastic Timed Net' where a transition can be associated with a stochastic number and introduce a minimum cycle time analysis method for 'Mixedly Distributed Stochastic Timed Net'. We also introduce a method of analysing a Web service system's response time with the minimum cycle time analysis method for 'Mixedly Distributed Stochastic Timed Net.'.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.38 no.4
• /
• pp.1-10
• /
• 2010

The scientific verification of the physiological and psychological effects that result from interaction with green plants would not only provide objective knowledge on the psychological effect of green but would also establish useful grounds for the creation of green spaces that consider human emotions. The present study measured the cerebral activity(cerebral blood flow) and the autonomic nervous system activity (blood pressure, pulse rate, amylase) of fifteen Korean male subjects as they inhaled the natural scent diffused by pine needles. Impression and mood state evaluations of the reactions to the pine scent were carried out using the SD method and POMS. Cerebral activity was observed to be significantly activated in the feeling, judgment, and motor areas of the frontal lobe, as well as the memory area in the temporal lobe. Verbal evaluations by the SD method and POMS indicated a pine scent left natural but stimulated and active impressions, provided vigor, and also reduced confusion. The autonomic nervous system activities, however, showed no significant differences. These findings verified scientifically that a pine scent vitalizes humans both physiologically and psychologically. These results could be useful as fundamental data for the design of green spaces that consider human emotional aspects.