• International Journal of Safety
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• v.11 no.2
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• pp.29-37
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• 2012

Since most construction workers comprehend information on work through sight, the importance of safety signs are increasing by the day. In Korea, due to the sharp economic progress and the higher standard of the workforce, since the end of 1980, each year the number of foreign workers entering the country who working simple technical jobs have increased this condition. This study researched safety signs, which are the final accident prevention measures at the workplace. Based on the study, comprehension of the standard safety signs of the Occupational Safety and Health Act (OSHA) was lacking at a level of 2.5. Also, the perception level of the Industry Public Safety Law (38%) was very low. And, it was found that sex and experience or non-experience in safety training was not an issue in the level of understanding. However, when satisfying the standards of the Occupational Safety and Health Act and changing the safety signs, the level of understanding went up to 3.49 and the perception level was increased significantly to 70%. Thus, it is concluded that, since the foreign workers are mainly from non-English speaking countries and because the workers of Korea are not familiar with English, in order to provide proper safety information, there must first of all be simplistic and concise pictograms. This will provide needed information and must be coupled with simple English words that can give additional information to the worker and be effective in helping him understand and perceive the safety sign. Also, it has been determined that the existing forms of safety signs and their effectiveness in industry accident prevention must be reassessed.

• Journal of Environmental Science International
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• v.22 no.3
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• pp.291-301
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• 2013

Sediment from the upstream channel has been deposited near the Nakdong River Estuary Barrage (NREB) due to the mild slope and decreased velocity. The annual mechanical dredging to ensure the flood capacity has been performed to remove the deposited sediment. However, the dredging method is not considered as an effective countermeasure due to high cost and long time to operate. Therefore, many methods for sedimentation reduction have been proposed for NREB. Especially, the channel contraction method to mitigate sedimentation problem by changing the channel geometry from 2 km to 3 km upstream of NREB has been recently suggested as an effective countermeasure. However, there is the possibility that the channel contraction method induces flood level increase compared to original condition. Therefore, it is necessary to investigate quantitatively the flood level changes in the upstream and downstream section due to the channel contraction method for NREB. In this study, water level changes by 10% channel contraction of whole width has been evaluated using the HEC-RAS model and simulated with and without channel contraction for various flood discharge. As a result, water level in the section where the channel was contracted was decreased by 0.02 m and flood level at the upstream of channel contracted was increased up to 0.015 m for the 500-year flood.

• Journal of the Korean GEO-environmental Society
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• v.15 no.6
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• pp.41-48
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• 2014

In this study, the behavior of fill dam with continuous water level change considering velocity changes via centrifugal model test was investigated. In addition, the collapse of fill dam due to the overflow was also experimentally simulated. The experimental results demonstrate that the pore water pressures and displacements vary in proportion to the water-level-change velocity, and the displacement increment is independent to the water-level-change velocity. Also, it is confirmed that the continuous water level change induces to the progress of fill-dam deformation due to displacement accumulation and the fill-dam stability dramatically degrades owing to the overflow. Hence, the real-time monitoring of pore water pressures and displacements of fill dam, and the control of water level in heavy rain through the countermeasure such as opening sluice gates are needed to ensure the stability of fill dam.

• The Journal of Engineering Geology
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• v.33 no.3
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• pp.461-474
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• 2023

The study area is located in Hyeonseo-myeon and Andeok-myeon of Cheongsong-gun, Korea around the Yeongcheon dam waterway tunnel, and in this paper, it is analyzed whether the groundwater level is recovered or not compared to groundwater level before waterway tunnel construction by measuring the groundwater level of 156 wells which were installed in areas near and away from the waterway tunnel. From September 2017 to August 2018, the groundwater level of the well was measured at least once a month, and as a result of groundwater level observation survey, the groundwater level of wells distributed in the directly affected zone by the waterway tunnel is relatively lower than that of the indirectly affected zone apart from the waterway tunnel. These results are estimated to be predominantly affected by the effect of waterway tunnel acting on geologic discontinuities rather than by terrain conditions, i.e. groundwater flows being leaked to the waterway tunnel through direct or indirect channels. Continuous monitoring and further investigation will be required to maintain groundwater facilities and preserve groundwater environments in the future.

• Journal of Korea Water Resources Association
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• v.50 no.2
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• pp.111-119
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• 2017

The underflow type movable weirs were arranged in a multi-stage way along a reach at the Chiseong River, where flooding has been observed frequently. With management water level of the movable weirs the control effects of storage and flood were suggested and the control effects were compared with those of existed weir system. The water level for the targeted storage and flood elevation was suggested by building the artificial neural network model. When the underflow type of movable weirs were arranged in a multi-stage way, the peak flood elevation decreased by 68.28% in the downstream compared with the existed weir system, and the total storage of the target section of multi-stage movable weirs increased by 216%. As a result of numerical simulation to build the artificial neural network model, 60%, 20%, and 20% among 216 data were used for the training, validation, and test, respectively. The training result of mean square error was $0.1681m^2$ and the high coefficients of determination were 0.9961, 0.9967, and 0.9943 in the training, validation, and test, respectively. As a result the water level management of each movable weir for the controls of flood elevation in the targeted downstream and targeted storage was suggested by using the artificial neural network.

• Korean Journal of Human Ecology
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• v.2 no.1
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• pp.45-51
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• 1993

The purpose of this study is to provide some information for the proper education on clothing wearing habits so that the education may be performed in the direction of social needs according to the social change and in the direction of the needs and interest of the high school girl students in their adolescence by being conscious of the influence of clothing on the high school girl students. I have used questionaire as an instrument of measurement. The length of the time of survey is from February 11, 1991 to February 28. The subjects are 544 first grade girl students of general high schools in Cheong-Ju, Choong-Ju, and Je-Cheon. The analysis of the data includes frequency, percentage, average person's Correlation Program, t-test, ANOVA, Scheffe's test. The conclusion of this study is as follows: The first, it is shown that (l)students's interest in the design and fashion of clothing is significantly related to the socio-anthropological and socio-psychological factors such and the education level of their fathers, the education level of their mothers, monthly income of their homes, the clothing habits of their home economics teachers, the subjects which they are interested in, their average scholoary achievements, their religious background, and whether they have boy friends or not, etd. (2)students' interest in purchasing of clothing is significantly related to the socio-anthropological and socio-psychological factors such as the education level of their fathers, the education level of their mothers, monthly income of their homes, the clothing habits of their home economics teachers, the subjects which they are interested in, their average scholoary achievements, and whether they have boy friends or not, etc. (3)students' interest in the social-psyclological aspect is significantly related to the socio-anthropological and socio-psychological factors such as their living area, the clothing habits of their home economics teachers, etc. (4)students' interest in the clothing construction is significantly related to only the clothing habits of their home economics teachersl. (5)students' interest in the clothing management is significantly related to the socio-anthropological and socio-psychological factors such as the education level of their parents, the age of their mothers, their religious background, and their sisters. The second, as for the interest of the high school girl students in clothing, it has been shown that those who wear school uniforms tend to have more interest than those who wear free-choice clothes in such areas as shopping, the construction, and management. As for the other two areas, that is, disign and fashion, and the interest in socio-psychological dependence there has been little meaningful difference between the two groups, while the uniform group has shown more interest than the other group. The third, the interest of hish school students in clothing is considered to be most seriously influenced by their socio-psychological dependence out of five areas of interest. It has been shown that the proportion of the content dealing with clothing wearing life in the high school home economics texbooks in relatively small, especially in such areas as socio-psychological dependence, shopping, management, and design and fashion except in construcion.

• Journal of the Korean Recycled Construction Resources Institute
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• v.6 no.1
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• pp.103-110
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• 2011

This study is to comparatively analyze the characteristics of pH decrease in recycled fine aggregates for embankment and landfill produced from waste concrete by using natural process and artificial process. The result was as follows In case of recycled fine aggregates left outdoor, it was found that pH level was decreased if the thickness of embankment becomes thinner, or the materials left outdoors owing to high concentration of $CO_2$ in atmosphere caused by respirations of people. When the air was permeated, pH level was decreased more effectively. It was analyzed that this phenomenon was caused by efficient supply of $CO_2$ in the recycled fine aggregates owing to high-pressure ventilators. In case of water spraying treatment, sprayed water facilitated hydration of unhydrated cement to dissolve calcium hydroxides which neutralized $CO_2$ in the atmosphere during desiccation process and decrease pH level by a considerable margin. In case of Immersed treatment, decrease of pH was not sufficient. When facilitating the supply of $CO_2$, pH level of the recycled fine aggregates was decreased by the largest margin. It was analyzed that this phenomenon was caused by efficient supply of $CO_2$. From the above results, it was analyzed that the most effective method of reducing pH level of the recycled fine aggregates from the aspects of pH reduction performance, economic efficiency and workability was repeated wet-dry cycles of spraying water to the aggregates in the proportion of 1:0.5 by weight and then treating by forcefully blowing $CO_2$ gas into the aggregates.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.8
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• pp.787-794
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• 2010

Recently, with sudden increase of supplying rate of cars and quantity of goods transported, traffic noisy becomes one of important factors obstruct environment of exhibition and view facilities have purpose in calmness and unsatisfaction about this is high now. Therefore, in case of exhibition and view facilities, it has to be grasped that satisfaction degree about the noisy in and out of the exhibition room by performing effect valuation on traffic noisy from design step. However the level of internal noise cannot be measured at the design phrase of the structure due to the noise of traffic. Up until now a walls transmission loss, based on the law of mass, is predicted using this method. However measuring the internal sound level after actual construction reveals that there is a large difference from measurements made at the design stage, and it is very difficult to find a solution after the opening of the structure. From research looking from this perspective the internal sound level was predicted- calculating the internal sound absorption ability, using acoustic simulation and loss prevention of an insulated wall- based on data collected to evaluate the internal sound of an exhibition room at a Folk Museum adjacent to a freeway. The results of this research are considered to provide important data for the prediction of internal sound level at the time of construction of exhibition facilities similar to this.

• Journal of the Korean Association of Geographic Information Studies
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• v.26 no.1
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• pp.56-68
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• 2023

A system that extracts seabed topographic information by simultaneously and continuously observing the horizontal position and water depth in the sea by combining a single beam echosounder and GNSS was constructed. By applying the developed system to actual measurements of small-scale sea areas, the effectiveness of bathymetry and sea-floor topographic data acquisition using GNSS and echosounder was examined. By using the developed outdoor program DS-NAV and indoor program DS-CAD and applying the tide level data at the time of actual measurement of the target sea area, it was possible to derive bathymetry results based on the datum level i.e. approximate lowest low water level(A.L.L.W). By using the developed outdoor program DS-NAV and indoor program DS-CAD and applying the tide level data at the time of actual measurement of the target sea area, it was possible to derive the results of bathymetric survey based on the datum level. From database built through the actual measurement. it was possible to create 3D model of the sea-floor topography and extract cross-sections. The results of this study are expected to be economically useful for extracting seabed topographical information from small sea areas or in dredging sites for offshore construction.

• Journal of The Korean Association For Science Education
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• v.43 no.2
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• pp.125-137
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• 2023

This study analyzed the types of knowledge building discourse and knowledge building processes in small group learning using augmented reality. Eight 8th grade students took classes using augmented reality in solubility, boiling and melting points. These classes were carried out twice and all the classes were videotaped and recorded. Every student participated in a semi-structured interview. In the types of knowledge building discourse, the proportion of knowledge sharing and knowledge construction was similar. Beneath the knowledge sharing, the proportion of introductory level discussion was higher than identifying key elements of augmented reality. Recalling existing knowledge rarely appeared. Under the knowledge construction, the proportion of advanced level discussion was the highest and the proportion of sharing and critiquing ideas at a different level and efforts to rise above current levels of explanation was similar. The introductory level discussion and identifying key elements of augmented reality were developed into efforts to rise above current levels of explanation and sharing and critiquing ideas at a different level. Visualized results of knowledge building processes showed all the students' graph drew an upward curve, though cumulative number of impact value was different by each student. As a result of the study, effective ways of improving small group learning using augmented reality are discussed.