• Title/Summary/Keyword: 강도등급

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Fusion research is the degree of participation leisure sports physically disabled persons on the objectified body consciousness(OBC) (지체장애인의 생활체육 참여정도가 객체화된 신체의식(OBC)에 미치는 융합 연구)

  • Kim, Dong-Won
    • Journal of the Korea Convergence Society
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    • v.7 no.5
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    • pp.247-254
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    • 2016
  • The purpose of this study is to identify the degree of participation sport for how this affects the objectified body consciousness of the Physically Disabled. The subjects were enrolled in the members participating in the sport for the disabled, while 221 people living in the city A. Data processing was carried out frequency analysis, factor analysis using SPSS 21.0 program, the analysis of the specific factors independent t-test and the way analysis of variance and multiple regression analysis was carried out. All statistical significance level was set at .05. First, population, gender (male), age of the sociological characteristics of the handicapped (40, 50), the objectification of the body consciousness level of the disability rating (Level 4) showed that a positive effect. Second, there are life sports participation rate (exercise duration, exercise time, exercise intensity) has positive effects on the body shame of objectification of the body consciousness of the handicapped, the body monitoring Exercise Period, the body shame, the intensity of exercise, control beliefs this exercise showed that each time a positive impact.

A Study of Engineering Properties of Rock Mass Weathered by Sea water (해수에 의한 암반 풍화의 공학적 특성 연구)

  • Choi Kang-Il;Kang Coo-Won;Go Chin-Surk
    • Explosives and Blasting
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    • v.23 no.1
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    • pp.9-17
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    • 2005
  • This study is to clarify the comparative relationship and mechanical anisotropy of granite distributed in the Nam-weon on the subject of weathered rock mass sea water surroundings. Artificial weathering test is defined as a test, which controls the weathering rate and agents by controlling the weathering rate and agents by artificial environmental of salt water. Increased weathering degree is large indicated by weathering salt water, such as apparent specific gravity, absorption, porosity, uniaxial compression strength, P-wave velocity, slake durability, shore hardness, indirect tensile strength(brazilian test) and cohesion were measured. As the Weathering salt water proceeds, cracks develope increasingly. A number the cracks affect the rock deformation. Therefore, stress-strain curve of weathered salt water rock in one confined state are quite differ from weathered fresh water rock those. A reason of their deformation type is the formation of micro-cracks and potential porosity caused by artificial weathering test.

Case Study of Derivation of Input-Parameters for Ground-Structure Stability on Foliation-Parallel Faults in Folded Metamorphic Rocks (단층 발달 습곡지반 상 구조물 안정성을 위한 설계정수 도출 사례 연구)

  • Ihm, Myeong Hyeok
    • The Journal of the Convergence on Culture Technology
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    • v.6 no.2
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    • pp.467-472
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    • 2020
  • Methods for deriving design input-parameters to ensure the stability of a structure on a common ground are generally well known. Folded metamorphic rocks, such as the study area, are highly foliated and have small faults parallel to the foliation, resulting in special research methods and tests to derive design input parameters, Etc. are required. The metamorphic rock ground with foliation development of several mm intervals has a direct shear test on the foliation surface, the strike/dip mapping of the foliation, the boring investigation to determine the continuity of the foliation, and the rock mass rating of the metamorphic rock. etc. are required. In the case of a large number of small foliation-parallel faults developed along a specific foliation plane, it is essential to analyze the lineament, surface geologic mapping for fault tracing, and direct shear test. Folded ground requires additional geological-structural-domain analysis, discontinuity analysis of stereonet, electrical resistivity exploration along the fold axis, and so on.

Use Impacts on Environmental Deteriorations of Trail and Campsite in Tokyusan National Park (덕유산 국립공원 등산로 및 야영장의. 환경훼손에 대한 이용영향)

  • 권태호;오구균;이준우
    • Korean Journal of Environment and Ecology
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    • v.7 no.2
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    • pp.241-251
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    • 1994
  • Use impacts on environmental deteriorations were studied on the four major trails and a campsite of Tokyuksan National Park in 1993. The entire width, bare width, maximum depth and slope of trail as the trail condition were significantly greater on the more heavily used trail. Percentages of rock-exposed, deepening, root-exposed points as the deterioration types of trail which were surveyed at the total of 106 points were higher and trail conditions were significantly different from those of non-deteriorated points. On the Paekryon trail, the damaged area more severe than Class 4 reaches about 910$m^2$/km and the use impact and deterioration on campsites were accelerated. The dominant trees of the the upper and lower layer in trail edge vegetation could be Quercus serrata and Acer pseudo-sieboldianum for Paekryon trail, Q. mongolica and Tripterigium regelii for the other trails. A. pseudo-sieboldianum, Q. serrata, Rhus trichocarpa, Fraxinus sieboldiana, Lespedeza maximowiczii, Symplocos chinensis for Pilosa were classified for tolerant species to use impacts.

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The macrobenthic community health was assessed using the Benthic Pollution Index(BPI) in Jinhae Bay, southern coast of Korea (저서오염지수를 이용한 진해만 해역의 저서건강도 평가 )

  • Jin-Young Seo;Jin-Woo Choi
    • Korean Journal of Environmental Biology
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    • v.40 no.4
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    • pp.510-524
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    • 2022
  • For the assessment of the benthic community health of Jinhae Bay using the Benthic Pollution Index, macrobenthic fauna samples were seasonally collected from 23 different sites between February, 2011 and November, 2012. The macrobenthic community health status was classified as "Poor" or "Very Poor" except for the bay mouth part of Jinhae Bay at the northern part of Geoje Island. A large proportion of functional Group IV and even azoic conditions appeared due to summer hypoxia at sites in sheltered regions of Jinhae Bay. Some of the dominant species recruited after summer hypoxia were Paraprionospio patiens, Sigambra bassi, and Theora fragilis belong to typical opportunistic species. By comparing the BPI values of the macrobenthic communities from other special management areas of Korea, Jinhae Bay was considered to have the lowest condition that was heavily polluted among special management areas.

Temperature-dependent Diffusion Coefficient of Chloride Ion in UAE Concrete (UAE 콘크리트에 대한 염화물 확산의 온도의존성)

  • Ji-Won Hwang;Seung-Jun Kwon
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.28 no.4
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    • pp.48-54
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    • 2024
  • NPP (Nuclear power plant) structures have been constructed near to the sea shore line for cooling water and exposed to steel corrosion due to chloride attack. Regarding NPP structures built in the UAE, chloride transport may be more rapid than those in the other regions since the temperature near to the coast is high. In this study, concrete samples with 5,000psi (35MPa) design strength grade were manufactured with the materials and mix proportions, which were the same as used in the UAE NPP structures, then chloride diffusion coefficients were evaluated considering temperature and curing age. The compressive strength and the diffusion coefficient were evaluated and analyzed for the samples with 28 and 91 curing days. In addition, chloride diffusion tests for 91-day-cured condition were carried out in the range of 20℃ to 50℃. The activation energy was obtained through converting the temperature slope to a logarithmic function and it was compared with the previous studies. The proposed activation energy can be useful for a reasonable durability design by using actual temperature-dependent chloride diffusion coefficient.

An Effect of TIG Dressing on Fatigue Characteristics of Non Load-Carrying Fillet Welded Joints (TIG처리에 따른 하중비전달형 필렛용접부의 피로특성)

  • Jung, Young Hwa;Kyung, Kab Soo;Hong, Sung Wook;Kim, Ik Gyeom;Nam, Wang Hyone
    • Journal of Korean Society of Steel Construction
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    • v.12 no.5 s.48
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    • pp.617-628
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    • 2000
  • In this study, the 4-point bending test has been performed in order to estimate the effect of TIG-dressing on fatigue strength and fatigue characteristics quantitatively for non load-carrying fillet welded joints subjected to pure bending. As a result of fatigue tests, fatigue strength of as-welded specimens has been satisfied the grade of fatigue strength prescribed in specifications of domestics and AASHTO & JSSC, and fatigue strength at $2{\times}106cycles$ of TIG-dressing specimens has been increased compared with as-welded specimens. As the result of beachmark tests, fatigue cracks have been occurred at several points, where the radius of curvature and flank angle in the weld bead toes are low, and grown as semi-elliptical cracks, then approached to fracture. As a result of finite element analysis, stress concentration factor in weld bead toes has been closely related to the flank angel and radius of curvature, and between these, the radius of curvature has more largely affected in stress concentration factor than flank angle. As a result of fracture mechanics approaches, the crack correction factor of test specimens has been largely affected on stress gradient correction factor in case a/t is below 0.4. From the relations between stress intensity factor range estimated from FEM analysis and fatigue crack growth rate, fatigue life has been correctly calculated.

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Mechanical Properties And Chlorde Penetration Resistance of Shotcrete according to Mineral Admixture Types and Supplemental Ratio (광물성 혼화재료의 종류 및 혼입율에 따른 숏크리트의 역학적 특성 및 염해 저항성)

  • Han, Seung-Yeon;Yun, Kyong-Ku;Nam, Kyeong-Gung;Lee, Kyeo-Re;Eum, Young-Do
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.7
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    • pp.4960-4968
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    • 2015
  • In this study to improve the chloride durability of the shotcrete structure depending on types and contents of mineral admixture chloride resistance was evaluated by NT BUILD 492 of european test standards. It was also evaluated with the mechanical properties such as static strength and chloride penetration resistance. For shotcrete mixed crushed stone aggregate of the maximum size 10mm of coarse aggregates was produced. Based on 28days compression strength the variable mixed with 15% silica fume showed the highest strength in 67.55MPa. As the content of fly ash and blast furnace slag increased, the strength lowered. In the chloride penetration resistance test, OPC showed "high grade" and In the case of admixture, the penetration resistance tended to increase in all variables except the fly ash. In order to evaluate the service life, the accelerated chloride penetration test was conducted by the standards of KCL, ACI, FIB. Test results were obtained with the lowest spreading factor in a variable mixed with silica fume of 15%. At the KCI standards, It was found to have a service life of about 65 years and at the FIB standards, It was found to have a service life of 131 years. Among standards, the service life of KCI standard in all of the variables was evaluated as the lowest.

Damage Characteristics of Korean Traditional Textiles by Nitrogen Dioxide (NO2) Concentrations (이산화질소(NO2) 농도에 따른 전통직물의 손상 특성)

  • Kim, Myoung Nam;Lim, Bo A;Kim, Seojin;Lee, Sun Myung
    • Journal of Conservation Science
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    • v.29 no.3
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    • pp.197-207
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    • 2013
  • The gas acceleration test was conducted to identify the deterioration of Korean traditional textiles caused by $NO_2$. Total 20 specimens were prepared using 4 different materials (silk, cotton, ramie, hemp) after dyeing with 5 colors (undyed, red, yellow, blue, black). The specimens were exposed to 0.01, 0.1, 1, 10, 100, and 1000 ppm $NO_2$ gas in the test chamber at $20^{\circ}C$, 50% RH for 1 day. Optical, chemical, and physical evaluation was carried out after the exposure. In the case of Korean traditional textile, color difference increased at 1 ppm/day, $NO_3{^-}$ concentration, carbonyl and C-$NO_2$ functional group increased while pH decreased at 10 ppm/day and tensile strength weakened at 100 ppm/day. when it comes to undyed textile, alteration of color difference on silk and hemp cloth, $NO_3{^-}$ concentration and tensile strength on hemp cloth was remarkable. In addition, color difference on blue and yellow textile, $NO_3{^-}$ concentration increase of yellow textile and tensile strength decrease of hemp cloth & ramie cloth were significant. The results suggest that critical $NO_2$ concentration of optical, chemical, and physical damage on Korean traditional textiles are 1ppm/day, 10 ppm/day, 100 ppm/day respectively.

An Experimental Study on the High Strength Lightweight Self-Compacting Concrete (고강도경량 자기충전콘크리트에 관한 실험적 연구)

  • Choi Yun-Wang;Kim Yong-Jic;Moon Han-Young
    • Journal of the Korea Concrete Institute
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    • v.17 no.6 s.90
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    • pp.923-930
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    • 2005
  • This paper was to evaluate the high strength lightweight self-compacting concrete(HLSCC) manufactured by Nan-Su, which main factor, Packing Factor(PF) for mixing design, has been modified and improved. We have examined HLSCC performance at its fresh condition as well as its mechanical properties at the hardened condition. The evaluation of HLSCC fluidity has been conducted per the standard of second class rating of JSCE, by three categories of flowability(slump-flow), segregation resistance ability(time required to reach 500mm of slump-flow and time required to flow through V-funnel) and filling ability(U-box test) of fresh concrete. The compressive strength of HLSSC at 28 days has come out to more than 30MPa in all mixes. The relationship between the compressive strength-splitting tensile strength and compressive strength-modulus of elasticity of HLSSC were similar those of typical lightweight concrete. Compressive strength and dry density of HLSCC at 28 days from the multiple regression analysis resulted as $f_c=-0.16LC-0.008LS+50.05(R=0.83)\;and\;f_d=-3.598LC-2.244LS+2,310(R=0.99)$, respectively.