• 한국안전학회지
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• 제10권4호
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• pp.87-96
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• 1995

It is only three(3) years since we applied brackets for scaffolding in the construction area. Unfortunately, there is no structural criteria on how to install those in the site so far, despite the fact that those brackets have been applied into the site by the firms already. It is shown that resistant capacity of each bracket type has been investigated, analyzed from this experimental study. Accident-concerning data on construction site analyzed by the Ministry of Labor, show temporary structure involves 18.6% of the total industrial accident, which the accidents from scafold-supporting brackets have rate of 42.5% of the ones occurred from the temporary structures. There are two main aspects to be observed : one is how much resistant capacity the brackets have themselves, the other is how exactly to install those without eccentricity. But practically, nobody does check of this bolt-installing conditions in the site and no check of tightening level of nut because there is no available tool to check torque amount for this kind of nut. We just have to rely on scaffolders experience of this tightening. This experiment involves just this variable of tightness at site. Eventually this insufficient tightness causes to collapse those scaffolding structures. The bracket might have less the one than its original capacity due to this insufficient tightness. Three(3) times of PIVOT tests show that fractured condition of two(2) row brackets has occurred mostly at lower bolt due to shear force. Therefore, tightness of bracket-installing bolt, tensile strength of the bolt, shear strength of the bolt, loading condition with equal two point or inequal two point loads, are mainly investigated as variables in this study.

• 대한물리의학회지
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• 제15권4호
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• pp.111-119
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• 2020

PURPOSE: In adults with hamstring tightness, stretching is considered a therapeutic exercise that improves flexibility. However, previous studies have reported efficacy of numerous methods, and are inconclusive in determining the most effective stretching techniques. This study aims to compare the outcomes of Evjenth-Hamberg stretching (E-HS), proprioceptive neuromuscular facilitation stretching (PNFS), and static stretching (SS), on muscle tone and flexibility. METHODS: A total of 30 subjects were assigned to each of the three stretching groups:; E-HS (n₁ = 10), PNFS (n₂ = 10), and SS (n₃ = 10). Muscle tone of the hamstring muscle, active knee extension (AKE), and passive knee extension (PKE) were assessed by range of motion. RESULTS: After the intervention, statistically significant differences were obtained between groups for muscle tone (p < .05). The post hoc test, showed statistically significant differences in muscle tone between the E-HS and PNFS groups (p < .05), and PNFS and SS groups (p < .05). Post hoc test after intervention, also revealed statistically significant differences in flexibility (p < .05) between the E-HS and PNFS groups (p < .05), E-HS and SS groups (p < .05), and PNFS and SS groups (p < .05). Moreover, a statistically significant difference was observed in PKE scores between the E-HS and SS groups (p < .05), and PNFS and SS groups (p < .05). CONCLUSION: This study indicates that E-HS may be the most effective stretching technique for muscle tone and flexibility, in adults with hamstring tightness.

• 에너지공학
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• 제24권4호
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• pp.63-70
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• 2015

창문에서의 틈은 열 손실 뿐만 아니라 차음 성능에도 중대한 결함으로 작용되며, 특히 인체에 유해한 미세먼지 유입 경로로도 작용된다. 이러한 틈을 제거하기위해 많은 시도들이 이루어지고 있으나, 창문의 고유 기능인 이동특성으로 인해 해결하기 어려운 난제로 인식되어왔다. 본 연구는 이를 해결하기위해 수평 회전 휠과 곡선 레일을 적용한 새로운 유형의 미서기 창문을 제작하고, KS 시험 기준에 따라 사용성, 내구성, 기밀성능, 등의 성능 시험을 하였다. 시험 결과, 개폐력은 2000 N 중량의 창문에서 30 N, 개폐 반복성 시험에서는 100,000 cycles, 기밀성 시험에서는 10 Pa에서 $0.00m^3/(m^2h)$의 성능을 보여주었다. 상기 시험 결과, 새로운 구동 방식을 지닌 본 연구에서의 창문은 기밀성과 경제적 측면에서 새로운 접근 방식을 제시하고 있다.

• KIEAE Journal
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• 제3권3호
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• pp.43-50
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• 2003

Nowdays the apartment is a main type of modernized residential buildings. According to the improvement of construction techniques and functions of windows and doors, recent apartments are enhanced air tightness of windows, doors and building envelopes. As Infiltration is decreased and natural ventilation is reduced, energy could be saved in winter. However, indoor air quality is bad. The air Infiltration of a building could be enlarged by physical actions, such as building designs, constructions and reduction of air tightness which is caused by aging. This research analyzes and measures with KNS-4000P (Sapporo air tightness measurement) the air tightness of the high rise apartments which is recently constructed and not occupied yet. With depressurization method, the KNS-4000 installed on the window and the indoor air-leakage was measured. At that time, Air come out from the edge of the windows and doors because of the pressure differences between indoor and outdoor. We measure the amount of the air as effective air leakage areas. This method of depressurization takes less time to measure than other methods and is less affected from other conditions. We measured infiltration of total 56 household, 29 households S apartment (total floor area : $64.42m^2$) in Balan and 29 households D apartment(total floor area : $78.21m^2$) in Chonan. As a result of the field measurements at October 2003, normalized leakage area of D apartment in Cheonan was $2.05cm^2/m^2{\sim}3.49cm^2/m^2$ (average: $2.77cm^2/m^2$) and normalized leakage area of S apartment in Balan is $1.23cm^2/m^2{\sim}1.68cm^2/m^2$ (average: $1.5cm^2/m^2$).

• 보건의료산업학회지
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• 제13권4호
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• pp.133-144
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• 2019

Objectieves: 본 논문의 목적은 정형외과 수술 중 골결손에 대하여 β-TCP를 이용하여 치료 받은 대상자의 방사선학적 결과를 평가하기 위함이다. Methods: 총 49명의 대상자 중 24명 (49.0%)는 남자 였으며, 25명 (51%)는 여자였다. 요인 분석을 위하여 의무 기록 검토가 시행되었다. 각 시기별로 골대체재의 흡수 정도는 Irwin 의 방사선학적 체계에 따라서 평가되었다. Results: 술 후 3개월 째, 세 가지 측정 변수인 골대체제 이식 견고성, 진단 당시 나이, 병변의 부피에 의한 회귀 모형의 설명력은 65.6% 였다. 술 후 6개월 째, 두 가지 측정 변수인 병변의 부피, 골대체제 이식 견고성에 의한 회귀 모형의 설명력은 32.9% 였다. 술 후 9개월 째, 두 가지 측정 변수인 병변의 장축 길이, 골대체제 이식 견고성에 의한 회귀 모형의 설명력은 30.8% 였다. Conclusions: 골대체제 이식 견고성, 병변의 부피, 진단 당시 나이 그리고 병변의 장측 길이가 골대체제의 흡수에 영향을 미치는 인자였다.

• 한국해양공학회지
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• 제22권4호
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• pp.40-45
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• 2008

This paper describes the effects of fly ash replacement on the water tightness of antiwashout underwater concrete, which replaced the cement with fly ash from 0% to 30%. The experimental work was performed to find out the depth of permeation of concrete specimens cast in air and cured in 23 $^{\circ}C$ tap water using an open center pressure type of water permeation tester. The results showed that the permeation depth values of antiwashout underwater concrete were deeper than normal concrete, but that an admixture using fly ash during antiwashout underwater concrete casting in air made it more watertight than normal concrete according to the water permeation testing. SEM observations of the specimens of fly ash antiwashout underwater concrete showed that it wasmore packed with structures because of the pozzolan reaction of the fly ash and cement.

• 대한토목학회논문집
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• 제2권4호
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• pp.33-38
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• 1982

지하류비축동굴의 성패는 지하수에 의하여 공동(空洞) 주위에 유지되는 수밀성(水密性)에 있다. 수밀성(水密性)이 보장되면 동굴에 저장된 유류의 gas가 유출되지 않으며 인접공동(空洞)이 비어 있을 시 이곳으로 이동하지 않는다. 본 연구에서는 전기상사모형실험(電氣相似模型實驗)을 통하여 동굴형태가 gas누출에 미치는 영향과 여러 가지 형태에서 유류이동을 방지하는 지하수위, 동굴내의 유류수준, 동굴간격 등이 검토되었다. 연구결과 동굴의 천정이 큰 곡율을 갖고 있으면 gas누출이 방지될 수 있음이 입증되었고 유류이동을 방지하는데 필요한 자연지하수위, 공동내의 유류수준 및 공동간격이 도표로 주어졌다.

• 한국의류학회지
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• 제10권3호
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• pp.9-16
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• 1986

In this research, we tested the fertile physical and the sensory properties and the handle of the domestic polyester fabrics were treated with the varying alkaline concentrations and temperatures were tested. The tests were conducted to determine the effects of the alkaline treatment on the changes of the physical and the sensory chrateristics of the domestic polyester fabrics. The results were as follows; 1. When treated with the varying alkaline concentrations from $7.5\%$ to $15\%$ at temperatures from $60^{\circ}C$ to $90^{\circ}C$, the weight decreasing phenomena were shown to as a linear equations increase in that range. 2. As the weight loss increased, the softness and the smoothness were increased but the fullness and the tightness were decreased. 3. The positive correlations were found between the sensory and the physical properties, and the fullness ana the tightness, while a negative correlation was found between softness and the smoothness. 4. The regression equations obtained by the sensory chrateristics related with the physical chracteristics were as follows ; Softness: y=84.01-0.74x Fullness : y=0.06+0.78x Smoothness: y=88.67-0.82x Tightness : y= 0.34+0.79x

• 한국재료학회지
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• 제27권3호
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• pp.155-160
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• 2017

Doped-$LaCrO_3$ perovskites, because of their good electrical conductivity and thermal stability in oxidizing and/or reducing environments, are used in high temperature solid oxide fuel cells as a gas-tight and electrically conductive interconnection layer. In this study, perovskite $(La_{0.8}Ca_{0.2})(Cr_{0.9}Co_{0.1})O_3$ (LCCC) coatings manufactured by atmospheric plasma spraying followed by heat treatment at $1200^{\circ}C$ have been investigated in terms of microstructural defects, gas tightness and electrical conductivity. The plasma-sprayed LCCC coating formed an inhomogeneous layered structure after the successive deposition of fully-melted liquid droplets and/or partially-melted droplets. Micro-sized defects including unfilled pores, intersplat pores and micro-cracks in the plasma-sprayed LCCC coating were connected together and allowed substantial amounts gas to pass through the coating. Subsequent heat treatment at $1200^{\circ}C$ formed a homogeneous granule microstructure with a small number of isolated pores, providing a substantial improvement in the gas-tightness of the LCCC coating. The electrical conductivity of the LCCC coating was consequently enhanced due to the complete elimination of inter-splat pores and micro-cracks, and reached 53 S/cm at $900^{\circ}C$.

• 지질공학
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• 제5권2호
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• pp.155-165
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• 1995

열극암반내의 지하수유동 및 용질이동 해석을 위해서는 추계론적인(Simulation Techique) 3차원 불연속체 모형(Discrete Fracture Model)이 요구된다. Monte Carlo 모의기법(Simulation Techique)에 의해 구성된 추계론적 불연속체모형을 지하 유류저장공동의 기밀성평가를 위한 지하수유동 및 용질이동 모의에 적용하였다. 불연속체모형구성에 영향을 미치는 열극 특성요소는 방향서 및 크기로 분석되었으며, 구성도니 모형(Model)에서의 지하수유동에 영향을 미치는 요소는 투수성 열극밀도로 분석되었다. Particle Tracking 기법을 사용한 불연속체모형의 용질이동 모의에서는 열극의 투수성에 의해 이동경로 및 이동속도에 많은 차이가 관찰되었다. 검증된 추계론적 불연속체모형은 지하 유류저장공동 기밀성평가에 적용이 가능함이 부분적으로 인정되었다.