• Journal of the Korea institute for structural maintenance and inspection
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• v.25 no.5
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• pp.182-189
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• 2021

VPS(Void Plywood Slab System, VPS) has optimized the shape of the hollow material. In addition, it has a function to prevent the floating of the hollow material and the separation due to the working load. In this study, the punching shear capacity of flat plate was performed using Void Plywood Slab System with form work panel proposed in the previous study. As a result of the test, the strength of the VSPS specimen in which the hollow material was placed beyond 2.0 times the column width from the loading point was reduced by 9.4% compared to the reference specimen. However, the strength value was about 1.57 times higher than the design value suggested by KBC 2016. It was found that there was no change in stiffness compared to the reference specimen until shear failure occurred in the VSPS specimen in which the hollow material was placed. It can be seen that this experiment is being destroyed by shear as the flexural reinforcing bars are sufficiently reinforced.

• The Journal of the Korea Contents Association
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• v.19 no.2
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• pp.99-111
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• 2019

With the low birth rate and the inner city decline, the number of small schools is expected to increase. In this trend, the Ministry of Education has consistently used the number of students as a standard for the merger and abolition of schools since 1982, but it seems that has generated a vicious circle of education in rural areas and also it did not reflect realistic requirements and changes in the times although it is efficiency of local education finances. With the number of students constantly decreasing, it has a high probability to make villages without schools in urban areas if decisions are made by the number of students. In this sense, it is suggested that regional contexts and socioeconomic environment should be taken into account rather than to conduct the merger and abolition of small schools with economic logic. It is necessary to change the direction of improving the quality of education through the operation of small schools for coexistence of schools and villages and a cultivating the manpower needed in the 21st century knowledge information society and the 4th industrial revolution era. Therefore, we tried to find tasks for expanding small schools of the local community and developing small schools suitable for future social change.

• Journal of the Korean Chemical Society
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• v.67 no.4
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• pp.253-270
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• 2023

The purpose of this study was to examine the effect of student-led assessment on achievement emotions and science concept understanding in middle school science classes. For this purpose, 4 of the 7 classes in the third grade of mid- dle school in small and medium-sized cities were selected as the experimental group and conducted student-led assessment, while the comparative group (3 classes) conducted teacher-led assessment. The student-led assessment consisted of 4 stages in which learners took initiative to set learning goals and develop assessment criteria, conduct self assessment and peer assess- ment, and carry out seven assessment activities. Student-led assessment was effective in improving positive achievement emotions and relieving negative achievement emotions and increasing students' science concept understanding in middle school students. Students perform student-led assessment, grasp their reach, and repeatedly go through reflective thinking to compensate for deficiencies in the learning process. Therefore, student-led assessment can be used as a tool to increase science concept understanding by continuously checking the level of science concept understanding.

• Journal of Nutrition and Health
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• v.41 no.5
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• pp.414-427
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• 2008

The purpose of the study was to develop an eating habit checklist for screening elementary school children at high risk of energy overintake. Dietary habits, food intake, anthropometric data were collected from 142 children (80 boys and 62 girls) in the 4th to 6th grades of elementary schools. Energy intake, fat intake, and percentage of Estimated Energy Requirement (%EER) were used as indices to detect the risk of energy overintake of the children. Pearson correlation coefficients were calculated between dietary habit scores and energy overintake indices in order to select questions included in the checklist. TV watching during the meal, meal speed, meal amount, overintake frequency, eatingout frequency, snack frequency, frequency of eating Ramyun or fast foods showed significant correlations with energy overintake indices. Stepwise regression analysis was performed to give each item a different weight by prediction strength. To determine the cut-off point of the test score, sensitivity, specificity, and positive predictive values were calculated. The 7-item checklist with test results from 0 to 13 points was developed, and those with equal or higher than 5 points were diagnosed as a risk group of energy overintake. Among our subjects 13.4% was diagnosed as the risk group. Mean energy intake of the subjects in the risk group and the normal group were 2,650 kcal and 1,640 kcal, respectively. However, there were no significant differences of Index of Nutritional Quality (INQ) of the other nutrients except eating fiber between the risk group and the normal group. This checklist will provide a useful screening tool to identify children at high risk of energy overintake.

• The Journal of Bigdata
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• v.5 no.2
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• pp.85-95
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• 2020

In this study, a mobility analysis method is suggested to estimate an O/D trip demand estimation using Mobile Phone Signaling Data. Using mobile data based on mobile base station location information, a trip chain database was established for each person and daily traffic patterns were analyzed. In addition, a new algorithm was developed to determine the traffic characteristics of their mobilities. To correct the ping pong handover problem of communication data itself, the methodology was developed and the criteria for stay time was set to distinguish pass by between stay within the influence area. The big-data based method is applied to analyze the mobility pattern in inter-regional trip and intra-regional trip in both of an urban area and a rural city. When comparing it with the results with traditional methods, it seems that the new methodology has a possibility to be applied to the national survey projects in the future.

• Journal of the Korean Geographical Society
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• v.30 no.3
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• pp.296-310
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• 1995

Classification of spatial units into meaningful sets is an important procedure in spatial analysis. It is crucial in characterizing and identifying spatial structures. But traditional classification methods such as cluster analysis require an exact database and impose a clear-cut boundary between classes. Scrutiny of realistic classification problems, however, reveals that available infermation may be vague and that the boundary may be ambiguous. The weakness of conventional methods is that they fail to capture the fuzzy data and the transition between classes. Fuzzy subsets theory is useful for solving these problems. This paper aims to come to the understanding of theoretical foundations of fuzzy spatial analysis, and to find the characteristics of fuzzy classification methods. It attempts to do so through the literature review and the case study of urban classification of the Cities and Eups of Kyung-Nam Province. The main findings are summarized as follows: 1. Following Dubois and Prade, fuzzy information has an imprecise and/or uncertain evaluation. In geography, fuzzy informations about spatial organization, geographical space perception and human behavior are frequent. But the researcher limits his work to numerical data processing and he does not consider spatial fringe. Fuzzy spatial analysis makes it possible to include the interface of groups in classification. 2. Fuzzy numerical taxonomic method is settled by Deloche, Tranquis, Ponsard and Leung. Depending on the data and the method employed, groups derived may be mutually exclusive or they may overlap to a certain degree. Classification pattern can be derived for each degree of similarity/distance $\alpha$. By takina the values of $\alpha$ in ascending or descending order, the hierarchical classification is obtained. 3. Kyung-Nam Cities and Eups were classified by fuzzy discrete classification, fuzzy conjoint classification and cluster analysis according to the ratio of number of persons employed in industries. As a result, they were divided into several groups which had homogeneous characteristies. Fuzzy discrete classification and cluste-analysis give clear-cut boundary, but fuzzy conjoint classification delimit the edges and cores of urban classification. 4. The results of different methods are varied. But each method contributes to the revealing the transparence of spatial structure. Through the result of three kinds of classification, Chung-mu city which has special characteristics and the group of Industrial cities composed by Changwon, Ulsan, Masan, Chinhai, Kimhai, Yangsan, Ungsang, Changsungpo and Shinhyun are evident in common. Even though the appraisal of the fuzzy classification methods, this framework appears to be more realistic and flexible in preserving information pertinent to urban classification.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.12
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• pp.8147-8156
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• 2015

This study analyzes the Pattern Language of Insadong-gil in street environmental design analysis for street vitalization. The urban public spaces, such as pedestrian streets, parks and plazas, have been increased with rapid urbanization and industrialization. But the fact is the satisfied spaces with the behavior patterns of users is little. This is because of the too much slanted thought toward formal supply and management of spaces without enough consideration for people and spatial quality of public spaces. The purpose of this study is to find out the factors to make the street more vital and diverse and to give the characteristic of region through the research on Insadong street with the pattern language of Christopher Alexander. So, throughout the value recognition of the changing urban street environment that has been changed by age selected spatial characteristic of public spaces. By selecting a suitable pattern language for each spatial characteristics provide the basis for street environmental design analysis. For this study, look at the relationship between pattern language focused on Insadong street, pattern language as the vitalization factor of street were analyzed 16 elements, including Pedestrian Street(100), Building Fronts(122), Activity Nodes(30) etc. This study focuses on street environmental design analysis of Insadong-gil through the Pattern Language, it propose the criteria and guidelines that will help enable street vitalization.

• The Korean Journal of Pesticide Science
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• v.16 no.4
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• pp.308-314
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• 2012

In order to monitor the residual pesticides in environment friendly agricultural commodities, fruits and fruiting vegetables. Twenty-five agricultural commodities were collected twice in May and August 2011 from nine environment friendly agricultural commodities-selling supermarkets and retail stores located in eight major cities in Korea. The number of each agricultural commodity collected, 555 samples in total, was 152 organic agricultural products, 202 pesticide-free agricultural products and 201 low-pesticide agricultural products. Pesticide residues in samples were analyzed by multiresidue method for 245 pesticides using a GC-ECD/NPD and an HPLC-DAD/FLD and the peaks suspected as pesticides were identified with a GC/MSD. As a result of pesticide residue analysis, three pesticides, bifenthrin, EPN and chlorpyrifos, were detected from four samples including apple, representing a detection rate of 0.72%. The residue levels of the four pesticide-detected samples were less than their maximum residue limits (MRLs) but one pesticide EPN detected from pear exceeded its legible criterion of one twentieth MRL. Estimated daily intakes of the pesticides detected from fruits and fruiting vegetables were less than 0.76% of their maximum permissible intake.

• Journal of Korean Society of Transportation
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• v.18 no.6
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• pp.89-99
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• 2000

To cope with the limits of conventional O-D trip matrix collecting methods, several approaches have been developed. One of them is bilevel Programming method Proposed by Yang(1995), which uses Sensitivity Analysis Based(SAB) algorithm to solve Generalized Least Square(GLS) problem. However, the SAB a1gorithm has revealed two critical short-comings. The first is that when there exists a significant difference between target O-D matrix and true O-D matrix, SAB algorithm may not produce correct solution. This stems from the heavy dependance on the historical O-D information, in special when gravel Patterns are dramatically changed. The second is the assumption of iterative linear approximation to original Problem. Because of the approximation, SAB algorithm has difficulty in converging to Perfect Stackelberg game condition. So as to avoid the Problems. we need a more robust and stable solution method. The main purpose of this Paper is to show the problem of the dependency of Previous models and to Propose an alternative solution method to handle it. The Problem of O-D matrix estimation is intrinsically nonlinear and nonconvex. thus it has multiple solutions. Therefore it is necessary to require a method for searching globa1 solution. In this paper, we develop a solution algorithm combined with genetic algorithm(GA) , which is widely used as probabilistic global searching method To compare the efficiency of the algorithm, SAB algorithm suggested by Yang et al. (1992,1995) is used. From the results of numerical example, the Proposed algorithm is superior to SAB algorithm irrespective of travel patterns.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.41 no.5
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• pp.543-550
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• 2021

Recently, there has been an increase of accidents related to the rise in the use of Personal Mobility Vehicle (PMV). To solve this problem, the National Assembly announced an amendment that restricted the use of PMV to bicycle roads and to prohibited for people under 13 years old to use PMV, but there is no detailed information about travel speed and safety. In this study, a survey was conducted by dividing the group into minors and adults based on the age of obtaining a driver's license to find out the direction of improvement of laws and systems about PMV. Our results showed that adults considered PMV as more dangerous (Adults 5.50, Minors 4.94) and the suggested age for PMV use was lower from minors than adults (Adults 15.70, Minors 13.85). We found that proper travel speed on bicycle roads differed according to the presence of a driveway (Driveway 26.21 km/h, Non-Driveway 23.55 km/h) and minors had higher a travel speed than adults on all types of bicycle road. Also, Helmets for PMV were seen as the most important safety equipment on all types of bicycle road. and the importance of other safety equipment differed according to the presence of a driveway (Driveway Front-Lighting, Non-Driveway Car Horn). Through this study, It proposes that we have to make new regulations about the use of front lights and horns, as well as enforcement measures that differentiate the speed on each bicycle road type as a way to improve the laws and systems for PMV.