• Journal of Environmental Health Sciences
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• v.4 no.1
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• pp.26-33
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• 1977

A bacteriological research of the school desks, bags and indoor-shoes was made from Oct. 2, 197 through May 28, 1976. The research included one girl's middle school, two boy's middle schools, two boy's high schools and 15 girl's high schools, alltogether 244 students from 28 schools, The research was analyzed and the results are as follows: 1) The research showed that 95% of the indoor-shoes materials were of cloth. Only 13% of the students carried the indoor-shoes in shoes sacks and 84.8% of them kept the shoes in schoolbags with books and lunchbox. 2) Only 5% of them cleaned their shoes every week and 79% cleaned every six. 3) 49.3% of the students kept the indoor-shoes in the school bag with other contents at home. 4) 88% of the bag was made of vinyl and 24.8% of the students carried their lunch in their bag without lunch box. 5) The research showed that 79.1% of the students never cleaned their bags. 6) In using the desk drawer, 58.2% of the students put their out-door shoes into the drawer, 18.9% of them kept their lunch in it, 11.9% used it keeping books alone and 11% keeping school bags with books. 7) 30.4% of the students had an experience of having cleaned their desks and 69.6% were unconcerned wirh desk-cleaning. 8) 34.4% of the indoor-shoes using school showed fecal coliform positive, 40.2% showed non-fecal coliform positive and 25.4% showed no reaction to IMViC. 9) The 34.4% of the fecal coliform positive showing schools, equivalant to 77 students, was composed of zero percents of girl's middle school, 18.2% of girl's high school, 36.4% of boy's middle school and 45.4% of boy's high school. 10) Among the 77 students, whose shoes showed fecal coliform positive, only 6.5% of them cleaned their shoes once in a week or a month and 62.3% of them cleaned them once in a six month. 11) The fccal coliform positive rate was higher in the cloth shoes materials than the vinyl materials. 12) The concrete-bottomed building higher positive rate (40.2%) than the wood-bottomed building (7.5%). 13) Even among the student's who frequently cleaned their desk drawer, 2.3% were in the positive, and among those who were unconcerned with drawer cleaning, 48.9% were involved in the positive. 14) In the fecal coliform positive rate of bags, 38.5% of the positive rate belonged to using indoor shoes while cleaning their class bottom with water, 53.8% belonged to using outdoor shoes while cleaning their class bottom with water, 7.7% belonged to using outdoor shoes while cleaning their class with oil.

• Korean Journal of Construction Engineering and Management
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• v.11 no.6
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• pp.111-121
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• 2010

As the customer's interest for sidewalk block in the street or apartment complex is increasing, the materials of block which had been a concrete block exclusively are varied to clay paver, native rock and wood etc. Especially, the sales volume of clay paver which is environment-friendly and ergonomic is dramatically increasing every year with two digits growth rate, however, many problems like "Edge Cracking" "Freezing Breakage" "Bending Breakage" "Joint Gap" are happening frequently within a couple of hours after installation due to the durabilities. Because of the characteristics of Ceramic products, clay pavers are very easy to be broken when they are bumped against each other. In addition, they are relatively fragile by a freezing expansion breakage when exposed to water due to hydrophilic property as well as the intensity and absorptance of the products are varied with small difference from the production process such as production equipment and process control. Therefore, it costs a lot of money to repair the breakdown unless production and installation is carried out according to the strict criteria of the quality control. In this study, the symptoms of breakdown frequently happened in clay paver are classified by each type and finally the solution for this problem in the production of brick, installation and criteria of quality control through compressive strength and absorptance test is suggested.

• Journal of the Korean Recycled Construction Resources Institute
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• v.5 no.4
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• pp.427-434
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• 2017

The generation of construction waste can be divided into a decommissioning phase and a new construction phase, and most of the waste is generated at the decommissioning stage. However, recently, domestic new construction construction has expanded to 150 trillion yards per year, so construction work is increasing rapidly. Especially, as the size of the construction work with much waste of construction waste exceeds 100 trillion, the management of the amount of construction waste in the new construction site is required. Unlike the dismantling work site, the new construction site can separate waste generated by each property, and relatively low foreign matter content is generated. The purpose of this study was to investigate the amount of construction waste generated by new construction sites and to calculate the unit amount of construction waste based on this. In addition, since the existing unit cost is centered on concrete and mixed waste, we set the basic unit by setting synthetic resin, waste wood, and waste board as additional items. The basic unit survey was carried out to investigate the wastes according to the characteristics of each construction period. As a result of the survey, the new construction site showed that most wastes were discharged in the first 30% and after 70% of the process, and the ratio of mixed construction waste was as high as 45%. As a result of this study, it was found that about twice as much waste was produced as compared with the conventional standard product.

• Journal of the Korea Institute of Building Construction
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• v.20 no.2
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• pp.171-181
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• 2020

Recently, free-formed construction technology is becoming a new measure of representing technological superiority and sociocultural ingenuity. However, the CNC processing technology utilizing the existing wood and iron form has limitations in terms of the manufacturing time and material cost. Therefore, in this study, the method and process of manufacturing free-formed EPS form using S-LOM-based 3D printing technology were suggested. Furthermore, through the mock-up test, a comparative analysis of the manufacturing time and precision with CNC milling technology was conducted. The results show that S-LOM-based 3D printing technology has reduced manufacturing time about 57.4% compared to CNC milling technology during the free-formed EPS form manufacturing process. In addition, compared to the design drawings, the maximum error value was 20.5mm, proving the applicability of S-LOM-based 3D printing technology. The results of this study are expected to contribute to the improvement of S-LOM method and the activation of S-LOM method by verifying the applicability of S-LOM-based 3D printing technology.

• Journal of Physiology & Pathology in Korean Medicine
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• v.19 no.5
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• pp.1181-1190
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• 2005

After study about the shapes of Jung, Gi, Sin, Hyul-kwa advocated by Master Jisan, the conclusions are drawn as follows. It pursues the rules of universe being changed from formless to concrete objects that the Body Essence, Vital energy, Mentality, and Blood are materialized to Jung, GE, Sin, Hyul-kwa. It can be drawn an inference from the next three theories that Jisan considered Jung, Gi, Sin, Hyul-kwa as round, square, reverse triangle, and triangle or oval shape. First, it was taken to following the shapes of viscera. Namely Jung-kwa was taken as Kidney, Gi-kwa as Lung, Sin-kwa as Heart, Hyul-kwa as Liver. Second, it was adopted from five kinds of constitutions according to the five elements in [Yeongchu Yin and Yang twenty five shapes] that is Jung-kwa is purchased with Water-earth phases, Gi-kwa with metal phase Sin-kwa with fire phase, Hyul-kwa with Wood phase, Third, it is taken in order to eliminate contradictions. Hyul-kwa disliking to move is assumed to round shape to easily move. Gi-kwa tending to disperse is chosen to square in order to be unmoved. Sin-kwa declining to stagnate of seven emotions is pursued to reverse triangle to compose oneself. Hyul-kwa inclining to gather is preferred to acreage phase to harmonize ascending tendency. Among shapes which Jisan was divided Hado, Nakseo, Bokhee pal kwoe, Moonwang pal kwoe, Jung-kwa as round is Hado, Gi-kwa as square is Nakseo, Sin-kwa as reverse triangle is Bokhee pal kwoe order shape, Hyul-kwa as acreage phase or oval shape is accord with Moonwang pal kwoe order shape. The reason being classified into Jung, GE, Sin, Hyul-kwa from the shapes of the face is that the face is the place to reflect the whole conditions of the body connected with all of the viscera and meridian system such as semen of plants. Above contents are drawn an inference from the transcription of Jisan's lectures and his writings. And it is considered that insufficient parts of the Jisan's theory must be demonstrated continuously.

• Korean Journal of Construction Engineering and Management
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• v.14 no.3
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• pp.107-114
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• 2013

The interest in traditional Korean housing has greatly increasing in Korean housing market. However, it is difficult to wildly disseminate for a high construction cost reason. In order to effectively facilitate the Hanok construction, Korean government has initiated a project that develops a new style Korean housing, which meets the requirements of low cost and modernized life style. Cost of building is mainly affected by materials and construction methods. Hanok has some special commodities those significantly impact the cost. In order to effectively cut down the costs, well-organized planning for costs is very important. Also, improving the productivity by utilizing new materials and methods can result in cost down. In this context, this paper compared and analyzed two different types of Korean housing; one is a modernized Korean house which used new materials and methods, the other is a traditional Korean house which was build up by purely traditional methods. Productivity has also been compared and analyzed for 5 major commodities between two types of models. Based on these comparative data, effect of cost down by new model has been analyzed. As a result it is confirmed that by using the new materials and methods could highly effect to increasing productivity and cost down. Especially, the cost of Roofing have been more influenced by using new material while the Wood and Finishes have been influenced by new construction method. Construction cost of Foundation (Earthwork, Concrete, Masonry) and Openings were influenced both factors, changing of materials and methods.

• Land and Housing Review
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• v.8 no.3
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• pp.189-200
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• 2017

The work breakdown structure and the precedence relations by work activity are very important because they are the basic data for estimating the construction duration in the construction work. However, there is no standard to accurately estimate the construction duration since the size of the school facilities construction is smaller than the general construction work. Therefore, some schools are unable to open in March or September and the delay of the construction duration can cause damage to the students. To solve this problem, this study developed a work breakdown structure of school facilities construction work and analyzed the precedence relations by work activities. The work breakdown structure of the school facilities construction is composed of three steps. The operations corresponding to level 1 and level 2 are as follows. (1) 2 preparatory work categories; preparation period and temporary construction. (2) 17 architectural work categories; temporary construction, foundation & pile work, reinforced concrete work, steel roof work, brick work, plaster work, tile work, stone work, waterproof construction, wood work, interior construction, floor work, metal work, roof work, windows construction, glazing work and paint construction. (3) 7 mechanic and fire work categories; outside trunk line work, plumbing work, air-conditioning equipment work, machine room work, city gas plumbing work, sanitation facilities and inspection & test working. (4) 4 civil work categories; wastewater work, drainage work, pavement work and other work. (5) 1 landscaping work categories; planting work. The work breakdown structure was derived from interviews with experts based on the milestones and detailed statements of existing school facilities. The analysis of precedence relations by school facilities work activity utilized PDM(Precedence Diagramming Method)which does not need a dummy and the relations were applied using FS(Finish to Start), FF(Finish to Finish), SS(Start to Start), SF(Start to Finish). The analysis of this study shows that if one work activity is delayed, the entire construction duration may be delayed because the majority of the works are FS relations. Therefore, it is necessary to use the Lag at the appropriate time to estimate the standard construction duration of the school facility construction. Lag is a term used only in the PDM method and it is used to define the relationship between the predecessor and the successor in creating the network milestone. And it means the delay time applied to the two work activities. The results of this study can reasonably estimate the standard construction duration of school facilities and it will contribute to the quality of the school facilities construction.

• Journal of Korea Water Resources Association
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• v.40 no.6 s.179
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• pp.485-494
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• 2007

This study was performed to evaluate the environmental qualities of the revetment construction methods and the river-facility materials using Life-Cycle-Assessment(LCA) for the nature-friendly design of close-to-nature river, The investigation results on the environmental qualities of energy and materials used to the close-to-nature river plan showed that the environmental impacts per unit weight increased in the order of gasoline > diesel > cement > wood. The environmental impacts per unit area of revetment construction method exhibited that the environmental loadings increased in the order of gabion > revetment > cribwork. In addition, it was observed that the environmental impact was reduced by improving the materials of zinc-galvanized wire. The model basin investigated in this study was the $0.3km^2$ area of river improvement works in Kyung stream, which is a tributary to the Seomjin river and the second regional stream. The research was conducted based on the 30years by life expectancy of artificial facilities. For the comparisons of revetment techniques with respect to the environmental qualities, the method resulted in the highest environmental loadings. The method using ready-mixed concrete ranked second in the environmental loadings of revetment techniques. The present results of this study are expected to play a beneficial role in the nature-friendly design of close-to-nature river by quantitatively identifying the environmental quality of total procedures (i.e., combination of techniques, selection of river-facility materials, maintenance of river-facility) applied to close-to-nature river plan.

• Journal of the Society of Disaster Information
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• v.17 no.2
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• pp.351-364
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• 2021

Purpose: Fire load analysis was conducted to secure basic data for evaluating fire risk of educational facilities. In order to calculate the fire load through a preliminary survey, basic data related to the fire load of school facilities were collected. Method: The basic data were the definition and types of fire loads, combustion heat data for the calculation of fire loads. The fire load was evaluated by multiplying the combustion heat by the weight of the combustibles in the compartment when calculating the fire load. Result: As for the fixed combustible materials of A-elementary school, the floor was mainly made of wood, in consideration of emotion and safety in the classroom, music room, and school office, and the rest of the compartments were made of stone. The ceiling and walls were made of gypsum board and concrete, so they were not combustible. The typical inflammable items in each room were desks, chairs, and lockers in the classroom, and the laboratory equipment box and experimental tool box were the main components in the science room, and books, bookshelves, and reading equipment occupied a large proportion in the library room. Conclusion: 'The fire loads of A-elementary' schools according to the combustibles loaded were in the order of library, computer room, English learning room, teacher's office, general classroom, science hall, and music room.

• Journal of the Society of Disaster Information
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• v.17 no.2
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• pp.195-205
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• 2021

Purpose: The ultraviolet reflectance and transmittance of coastal building materials are one of the important factors of ultraviolet radiation in and out of coastal building. In this research, the ultraviolet spectral reflectance of many kinds of building materials was measured. Also, the relationships with the lightness, roughness, and chromaticity, which are surface characteristics, were reviewed and suggested. Method: In this study, according to the CIE classification, the ultraviolet region was defined as short-wavelength region UV-C(10nm~280nm), medium-wavelength region UV-B (280-315 nm), and long-wavelength region UV-A (315-400nm), and the visible light region was defined as (400nm~780nm). Spectrophotometer was used to continuously measure the reflectance from the ultraviolet region to the visible light region. Results: From the measurement results, the ultraviolet reflectance on Wood was shown to be about Visible 55-68%, UV-A^* 7-12%, and UV-B 4-5%. Wall tiles are about Visible18-40%, UV-A^* 8-20%, and UV-B^* 7-8%. That on concrete was shown to be about Visible 37%, UV-A^* 28%, and UV-B^*19%. Conclusion: The ultraviolet reflectance can be estimated by visible reflectance. Also, it is important to select a variety of materials according to the application when blocking UV.