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Actual condition survey for thermokeeping of winter school uniforms (겨울철 교복의 보온성 개선을 위한 실태조사)

  • Kim, Yumi;Lee, Jeongran
    • Journal of Fashion Business
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    • v.17 no.2
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    • pp.82-94
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    • 2013
  • This study aims to investigate purchase attitude towards uniforms, wear condition and their requirements for functional school uniforms for high school boy students, and to help to present basic data for the development of functional school uniforms by reflecting requirements from high school students. First, research on school uniform brands purchased in Busan, Ulsan, and Kyungnam regions showed 2 brands were preferred, and the school uniform purchase expenses are primarily between two hundred thousand won and three hundred thousand won. Second, in terms of differences among fabrics of summer and winter uniforms, many students answered that 'they are similar' or 'there is no difference'. As for complaints about winter uniforms, thermal insulation accounts for the highest rate. As a result of research on underwear worn primarily in the winter, boy students tend to wear underwear to keep their lower bodies warm rather than their upper bodies. They tend to keep their upper bodies warm with outerwear such as vests, cardigans, and padding jumper. According to a survey on experience and satisfaction of functional uniforms, students showed satisfaction with more than three points to all questions except for two, which means their satisfaction about the functions of uniforms that they wear currently is above the average. Third, many boy students complains about the thermokeeping of winter uniforms, especially thigh parts of pants. It is required to make research for the improvement of functional pants for boy students.

Electrical fire prediction model study using machine learning (기계학습을 통한 전기화재 예측모델 연구)

  • Ko, Kyeong-Seok;Hwang, Dong-Hyun;Park, Sang-June;Moon, Ga-Gyeong
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.11 no.6
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    • pp.703-710
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    • 2018
  • Although various efforts have been made every year to reduce electric fire accidents such as accident analysis and inspection for electric fire accidents, there is no effective countermeasure due to lack of effective decision support system and existing cumulative data utilization method. The purpose of this study is to develop an algorithm for predicting electric fire based on data such as electric safety inspection data, electric fire accident information, building information, and weather information. Through the pre-processing of collected data for each institution such as Korea Electrical Safety Corporation, Meteorological Administration, Ministry of Land, Infrastructure, and Transport, Fire Defense Headquarters, convergence, analysis, modeling, and verification process, we derive the factors influencing electric fire and develop prediction models. The results showed insulation resistance value, humidity, wind speed, building deterioration(aging), floor space ratio, building coverage ratio and building use. The accuracy of prediction model using random forest algorithm was 74.7%.

Effect of perlite powder on properties of structural lightweight concrete with perlite aggregate

  • Yan, Gongxing;Al-Mulali, Mohammed Zuhear;Madadi, Amirhossein;Albaijan, Ibrahim;Ali, H. Elhosiny;Algarni, H.;Le, Binh Nguyen;Assilzadeh, Hamid
    • Structural Engineering and Mechanics
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    • v.84 no.3
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    • pp.393-411
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    • 2022
  • A high-performance reactive powder concrete (RPC) has been readied alongside river sand, with 1.25 mm particle size when under the condition of 80C steam curing. As a heat and sound insulation, expanded perlite aggregate (EPA) provides economic advantages in building. Concrete containing EPA is examined in terms of cement types (CEM II 32.5R and CEM I 42.5R), doses (0, 2%, 4% and 6%) as well as replacement rates in this research study. The compressive and density of concrete were used in the testing. At the end of the 28-day period, destructive and nondestructive tests were performed on cube specimens of 150 mm150 mm150 mm. The concrete density is not decreased with the addition of more perlite (from 45 to 60 percent), since the enlarged perlite has a very low barrier to crushing. To get a homogenous and fluid concrete mix, longer mixing times for all the mix components are necessary due to the higher amount of perlite. As a result, it is not suggested to use greater volumes of this aggregate in RPC. In the presence of de-icing salt, the lightweight RPC exhibits excellent freeze-thaw resistance (mass is less than 0.2 kg/m2). The addition of perlite strengthens the aggregate-matrix contact, but there is no apparent ITZ. An increased compressive strength was seen in concretes containing expanded perlite powder and steel fibers with good performance.

Study of the Method to Examine the Cause of Damage to a Flat-Type Vinyl Cord (VFF) According to the Type of Energy Source (에너지원의 종류에 따른 비닐평형코드(VFF)의 소손원인 판정기법에 관한 연구)

  • Choi, Chung-Seog
    • Fire Science and Engineering
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    • v.25 no.6
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    • pp.83-88
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    • 2011
  • This study presented the structure and characteristics of vinyl cords used for wiring electric equipment and appliances and analyzed the photographs of damaged flat-type vinyl cords (VFF, $1.25mm^2$) and the metallic cross-sectional structure of melted conductors. Normal VFFs were made by twisting several strands together and the surface of the conductor was red brown. In addition, from the analysis of the metallic structure of the conductor, it was found that its grains had been elongated. The surface of a VFF damaged by normal flame showed no sheen with carbonized insulation material fused on the conductor surface. In addition, from the analysis of the cross-sectional structure of the melted area, it was found that voids of a certain shape were formed on it but that the cord's own elongation structure could not be checked. The cross-sectional analysis of the melted conductor damaged by the external flame applied to a VFF to which electric current was being applied showed no elongation structure for each cord, and revealed that irregular voids and a columnar structure had grown. The surface of the VFF damaged by overcurrent was uniformly carbonized and the cross-sectional structure analysis of the melted conductor revealed that the dendritic structure had grown. The analysis of the characteristics of the VFF melted by short-circuit showed that even though some part of the surface was contaminated, it showed little sheen and that the area rebounded by melting was round in shape. In addition, the cross-sectional structure analysis using a metallurgical microscope showed the boundary surface and columnar structure and revealed an amorphous structure like normal copper at areas other than the melted conductor.

Water Temperature and Sound Environment Characteristics of Huanren Brown Frog Oviposition Sites (계곡산개구리 산란지의 수온 및 음환경 특성)

  • Ki, Kyong-Seok;Gim, Ji-Youn;Lee, Jae-Yoon
    • Korean Journal of Environment and Ecology
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    • v.30 no.3
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    • pp.344-352
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    • 2016
  • The goal of this study was to identify the water temperature and sound environment of oviposition sites of the Huanren brown frog (Rana huanrensis), which breeds in valleys in early spring. The study was conducted in Chiak National Park, central Korea, between March 23 and April 24, 2015. Correlation analysis of the physical factors of oviposition sites revealed that the number of egg clutches was positively correlated (p < 0.05) with the water temperature and negatively correlated (p < 0.05) with the sound volume of the oviposition sites. However, no correlation was found between clutch number and the total area or depth of water. The water temperature of the oviposition sites was $2.2^{\circ}C$ higher on average than that of the mainstream (p < 0.001). To avoid the low early spring temperatures, R. huanrensis spawned in sites with accumulated water, in which the depths were less than 10cm and the temperature was relatively high. Further, eggs were spawned in clusters in small spaces to maximize the thermal insulation effect. In terms of noise levels, oviposition sites were found to be 6.9 dB quieter than the mainstream (p<0.001). In conclusion, R. huanrensis was found to spawn in warm, quiet, and small oviposition sites in valleys to avoid low early spring temperatures and loud water noise. This study is significant because it is the first to characterize the sound environment of amphibian oviposition sites.

A Study on the Standard Drawings of Seoul Middle School Architecture in 1975 (1975년 서울시 중학교 표준설계도에 관한 연구)

  • Lee, Jeong-Woo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.14 no.5
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    • pp.2497-2504
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    • 2013
  • This study aims to analyze the 'Standard Drawings for School Facilities' issued by Seoul Education Committee in 1975 because it is the early example for middle school architecture. The results of this study are summarized as follows 1) In general trend of single-corridor type block plan, there are also changes in floor plan like no-corridor type block plan, $9.9{\times}6.6m$ classroom unit for the better daylight condition, built-in storage for students. 2) As for elevation design, it is characterized as daylight-oriented, functional exterior for without making full use of design elements. 3) Standardized dimensions are used as a rule in the height of story, ceiling, window sill and etc. Transitional characteristics of the early RC school architecture are found in exposed ceiling, incomplete insulation structure and mixed use of wood framed floor of earlier type. 4) Contrast to main school building, gymnasium shows the intend to express the symbolism of school architecture with diverse elevation design elements and the plasticity of building mass. 5) Separated plan of toilet and night-duty building also show the transitional characteristics. As conclusion, though showing the stereotyped school architecture, on the other hand, 'Standard Drawings for School Facilities' (1975) makes it possible to see the way of coping with the demands for school architecture in that time and the transition of school architecture. This is the main value of it as the material for the studies related to the history of educational facilities.

A Study on the Application of Finishing Materials According to the Locational Function of the Chapel in Church Space (교회공간 예배실의 위치적 기능에 따른 마감재 적용 연구)

  • Yeo, Mi;Lee, Chang No
    • Korean Institute of Interior Design Journal
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    • v.24 no.1
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    • pp.178-188
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    • 2015
  • This study has the main objective of being of help as a reference data for the application of the finishing materials when designing the interior of the chapel of the church space through analysis of the finishing materials against the chapels of church space which has complex function. As precedent studies for this, the composition of the function and concept of the church space was surveyed and the complex function of the church space was surveyed. The theoretical surveyed was performed according to the casual composition, behavior of the community and role and location of the duties of the church members. The case objects were 10 chapels constructed by 5 professional interior design companies. The content of the analysis was the finishing materials in the chapels and their application characteristics. The detailed considerations to be referred to when designing the interior of the chapels of church space in the future were proposed. The analysis result of the application of the finishing materials according to the locational function of the chapels of church space can be explained as follows. First, the platform area was the characteristic of applying finishing materials which induce visual immersion. As for the floor materials in the platform, in order to minimize the floor sound and vibration phenomenon occurring during movements, noise insulation and dust protection rubber sheet was place and on top of it the floor or the carpet was placed. Second, the Choir area had the difficult problem of having to consider the appropriate sound absorption occurring due to the proliferation of sound and performance of classical instruments at the same time. However, in the case, this problem was solved through the sculptures of convex shape. Third, since the scheelite is a space where many people move around, the finishing material which absorbs sound was mainly used. Fourth, the entrance area was composed of thick wall materials compared to other walls, and the sound absorption character was most significantly considered when applying the finishing material. Fifth, the broadcasting room was composed either in independent type or an open type and performed its function and the main finishing materials was transparent glass which was highest use frequency.

Analysis Method for Damage Patterns of Low Voltage Switches for PL Judgment (PL 판정을 위한 저압용 스위치의 소손 패턴 해석기법)

  • Choi, Chung-Seog
    • Fire Science and Engineering
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    • v.24 no.5
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    • pp.136-141
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    • 2010
  • The purpose of this study is to examine the structure and heat generation mechanism of low voltage switches used to turn on or off the power supply to an indoor lighting system and investigate how the fixtures and movable contacts of the switches are damaged depending on the types of energy sources in order to secure the judgment base for expected PL disputes. Based on the Korean Standard (KS) testing method for incombustibility, this study applied a general flame to the switch. In addition, current was supplied to the switch using the PCITS (Primary Current Injection Test System). The ambient temperature and humidity were maintained at $22{\pm}2^{\circ}C$ and 40~60% respectively while performing the test. It is thought that the switch generated heat due to a defective connection of the wire and clip, insulation deterioration and defective contact of the movable contact, etc. The surface of the switch damaged by the general flame was uniformly carbonized. When the flame source was removed, the fire on the switch was extinguished naturally. From the result obtained by disassembling the switch carbonized by the general flame, it could be seen that fixtures and movable contacts remained in comparatively good shape but the enclosure, clip support, movable contact, indicating lamp, etc. showed carbonization and discoloration. In the case of the switch damaged by overcurrent, the clip connecting the wires, clip support, etc. showed almost no trace of damage, but the fixtures, movable contact, indicating lamp, etc. were severely carbonized. That is, the sections with high contact resistance were intensively damaged and showed a damage pattern indicating that carbonization progressed from the inside to the outside. Therefore, it is possible to judge the initial energy source by analyzing the characteristics of the carbonization pattern and the metal fixtures of damaged switches.

A Study on Fire Performance Evaluation of EIFS on Anti-Flaming Finish by Cone Calorimeter Test (콘칼로리미터에 의한 외단열시스템의 방염 화재성능평가를 위한 연구)

  • Min, Se-Hong;Sun, Ju-Seok;Kim, Sang-Chul;Choi, Yong-Mook;Lee, Seok-Ki
    • Fire Science and Engineering
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    • v.26 no.3
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    • pp.106-111
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    • 2012
  • In this study, EIFS (Exterior insulation finish system) of exterior cladding was applied Cone calorimeter test to confirm the effect of flame retardant. As a results, the initial ignition points in accordance with the coated form and concentration of the flame retardant was delayed. But flame resistant treatment of EIFS cladding to control the fire will not affect confirmed that. In addition, EIFS that uses high-density and low-density due to difference in the density of the impact of the fire was no difference. The exterior of the ignition experiment occurred before and after 40 seconds, heat release rate to 100 seconds appears to occur about 90 % compared with the other exterior wall materials, the initial fire spread very fast was confirmed. EIFS cladding in order to prevent the spread of fire in the application of EIFS legally use is limited by the use of the building. And flame spread can be prevented, such as a vertical outer wall compartment measures are urgently needed.

Overview of Technology for Fixation of Carbon Dioxide Using Microalgae (미세조류를 이용한 이산화탄소 고정화 기술 현황)

  • Jeon, Seon-Mi;Kim, In Hae;Ha, Jong-Myung;Lee, Jae-Hwa
    • Applied Chemistry for Engineering
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    • v.19 no.2
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    • pp.145-150
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    • 2008
  • In this work we have studied the antifouling properties of the hydrophobic sol-gel modified sensing membrane and its optical properties for sensor application. E. coli JM109, B. cereus 318 and P. pastoris X-33 were cultivated in confocal cultivation dishes with glass surface, respectively. The glass surface was coated with the hydrophobic sol-gels prepared by the dimethoxy-dimethyl-silane (DiMe-DMOS) and tetramethyl-orthosilicate (TMOS). After cultivation, microorganisms adhered on the surface coated with sol-gels and glass surface were dyed by gram-staining method and the numbers of microorganisms were analyzed based on the image data of the scanning electronic microscope (SEM). A great number of microorganisms, about $2{\sim}3{\times}10^4/mm^2$, was adhered on the glass surfaces which no hydrophobic sol-gels were coated. But, the antifouling effect of the hydrophobic sol-gels was large, that microorganisms of less than $200{\sim}300/mm^2$ were adhered on the coated glass surface. The performance of the sensing membranes for detection of pH and dissolved oxygen was enhanced by recoating the light insulation layer prepared with the mixture of the hydrophobic sol-gel and graphite particles.