• 복식
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• 제58권6호
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• pp.24-34
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• 2008

The purpose of this study was to create a database of information on fabric factors(i.e., fabric insulation, fabric weight, clothing weight, fabric thickness, air permeability, and water vapor resistance) of clothing used for insulations, to compare them according to clothing types, and to estimate thermal resistance of clothing using these factors. A total of 25 kinds of clothing were selected(9 types for suits, 6 types of jacket, 5 types for shirts, and 5 types for trousers). The results of this study were as follows; Thermal insulation of clothing showed the highest positive correlation(0.85, p>0.01) with thermal insulation of fabric and very high positive correlation with water vapor resistance, fabric thickness, fabric weight, and clothing weight, respectively, 0.77, 0.77, 0.73, 0.71(p>0.01). Fabric weight of jacket was higher than that of shirts and trousers. Air permeability of shirts was the highest of clothing types. Clothing insulation of jacket was higher than that of shirts and trousers and its fabric insulation was also the highest of clothing types. Regression analysis showed that fabric thickness, water vapor resistance, and fabric weight would be useful factors for estimating the thermal resistance of clothing.

• 한국안전학회지
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• 제31권6호
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• pp.25-31
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• 2016

This paper has analyzed the structure, applicable regulations and the resistance characteristics of insulation ring type of CSST (Corrugated Stainless Steel Tubing for Gas). With the flammability test conducted in accordance with KS C IEC 60811-1-1, the evaluation of insulation resistance, temperature characteristics, and reliability has been conducted. An insulation ring type CSST consists of protective coating, tube, nut, insulation ring, packing, socket, and ball valve. Connecting an insulation ring type CSST to gas tubings for gas appliance is not permitted, moreover, the product shall be installed inside a sleeve pipe in case of buried installation such as the ceiling. Damages on protective coating and tube were detected when fire was applied to the test sample with a portable torch for 60 seconds. The insulation resistance of a normal product was $49.59M{\Omega}$, while that of the product completed the flammability test reduced to $9.21M{\Omega}$. The mean insulation resistance within the confidence Interval of 95% using the mini tap program 17 was $49.59M{\Omega}$ and the mean insulation resistance within the confidence interval reduced to $9.21M{\Omega}$. In the normal distribution analysis of 95% confidence interval, the value-P of the normal product was stable at 0.075 and AD(Anderson-Darling) statistic value was turned out to be 0.063, which is very normal, and the standard deviation was analyzed as 0.2586. The value P of the product completed the flammability test resulted in 0.005, the AD was 1.355 and the standard deviation reduced to 0.07908.

• 한국전기전자재료학회논문지
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• 제21권12호
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• pp.1124-1129
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• 2008

The object of this paper is to acquire the data related to insulation evaluation of hybrid vehicle traction motors. We made a comparative analysis on Insulation Resistance (IR), Dielectric Absorption Ratio (DAR), and Polarization Index (PI) of the motor stators. The experiment was carried out according to IEEE Std. 43 and IEC 60085-1 for insulation resistance test standard of rotating machinery. Test voltage of 500 V was applied between a phase and the enclosure. The IR and the DAR of used motors were lower than those of new ones. The DAR and the PI were $0.92{\sim}1.02$ and $0.74{\sim}1.1$, respectively and the result did not meet the recommendation basis 2 for insulation level H. From the experimental results, we could prepare parameters and basis for insulation evaluation of the traction motor stator by the comparative analysis of short-time insulation resistance changes, DAR and PI.

• 한국안전학회지
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• 제38권2호
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• pp.15-22
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• 2023

In this study, the process and the environment of a melting furnace, located in Workplace A in Chungnam Province was inspected, and the insulation resistances of electrical circuits and motors were measured, and their changes over five years (2017-2021) were analyzed. It was found that the exhaust fan, oil pumps #A and #B, and heater were installed in 2010. Their insulation resistances decreased from 2017. Specifically, the insulation resistance of Oil Pump #A decreased from 100 (㏁) in 2018 to 20(㏁) in 2021, an 80% reduction. The fast decrease in insulation resistance was due to the high temperature of the melting furnace affecting surrounding the electrical facilities. A safety management scheme on the electrical facility of the melting furnace was proposed.

• 복식
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• 제58권9호
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• pp.29-37
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• 2008

The purpose of this study was to investigate insulation of thermal clothing under still and dynamic air conditions(with 2.1m/sec air velocity) and decrease of insulation in both conditions, to analyze correlations among them, and to estimate insulation and decrease of insulation using factors, such as fabric insulation, fabric weight, clothing weight, air permeability, and water vapor resistance. A total of 25 kinds of clothing were tested(9 types for suits, 6 types of jacket, 5 types for shirts, and 5 types for trousers). The results of this study were as follows; Thermal resistance of clothing under the dynamic air condition decreased comparing to that of clothing under still air condition in all types of clothing. Decrease in shirts was the biggest(47.5%), followed by suits(39.51%), trousers(37.48%), and jackets(34.49%) in sequence. Thermal resistance of clothing under dynamic air condition showed very high correlation(0.98, p<0.01) with that of clothing under still air condition, followed by thermal resistance of fabric(0.86, p<0.01). Decrease in thermal resistance of clothing showed the highest correlation with air permeability. It didn't show correlation with other factors. Regression analysis showed that fabric thickness would be useful factor for estimating thermal resistance of clothing and air permeability also would be useful factor for estimating decrease in thermal resistance of clothing.

• 한국안전학회지
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• 제34권5호
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• pp.22-30
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• 2019

In 2018, overload, overcurrent, insulation aging, and a contact failure caused 659 electric fires. There is almost no failure of electrical socket outlets during their manufacturing or installation period. After several months or several years, overload or overcurrent of electrical socket outlets leads to a contact failure or short circuit which causes an electric fire. Therefore, this paper analyzed for thermal characteristics based on a current value and the change in insulation resistance along with a temperature rise caused by electrical socket outlets and the state of laboratory use in workplaces. As a results, regarding the thermal characteristics based on the current value of each installation year, a temperature increase was related to a current value, an installation year, and whether the contact unit is corroded. Insulation resistance began to decrease when a temperature increased to a certain level. With a lapse of installation year, the temperature at which insulation resistance began to decrease was lowered. This paper can be applicable for the survey data about electrical socket outlet induced fire accidents and management guidelines.

• 전기전자학회논문지
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• 제23권2호
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• pp.370-374
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• 2019

본 논문에서는 전기재해를 일으킬 수 있는 요소를 미리 제거하기 위해 보다 효율적이고 신뢰성 있는 누설전류 검출방법을 찾고자 온도, 습도가 다른 환경에서 누설전류 및 절연저항을 측정하여 그 측정값에 대한 차이점을 비교하고 분석하였다. 식당과 상점에서 누설전류 및 절연저항을 비교한 결과 식당에서 누설전류와 절연저항은 모두 허용값을 만족하였지만 2개 회로는 누설전류가 높게 나타났을 때 절연저항도 높게 나타나는 비정상적인 비례관계를 나타내었다. 상점에서 누설전류와 절연저항은 1개 회로에서 누설전류가 허용값 이하로 부적합하였지만 절연저항은 모두 허용값을 만족하였다. 누설전류 및 절연저항이 허용값 이내일 때도 비정상적인 비례관계를 나타냈으며 이러한 부하는 대부분 전열부하로 분석되었다.

• 복합신소재구조학회 논문집
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• 제3권2호
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• pp.36-46
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• 2012

Structure Insulated Panel (SIP) is an wooden structure material with which structure and insulation functions are satisfied. Hence, it would be a cost-effective model to implement low energy house which has higher insulation and structure performance and which the wall thickness is able to be reduced. In this study, performance of thermal insulation and fire resistance were evaluated in order to verify applicability to low energy house. Fire resistance test is performed on vertical load bearing members for partitions, and the test results satisfy one hour of fire resistance condition according to KS F 2257. The members include two layers of fireproof gypsum board with thicknesses of 12.5mm attached to SIP. Thermal insulation performance is satisfied with the 2012 standard ($0.225W/m^2{\cdot}K$). As the performance of resistance and thermal insulation are satisfied, SIP is expected to be applied to low energy building materials. In the future, the structural safety will be confirmed by structural performance and seismic performance test and the guidelines for distribution will be drawn up.

• 전기학회논문지
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• 제67권8호
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• pp.1106-1112
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• 2018

In this paper, measurement techniques are presented to test the performance of insulation without interruption if it is difficult to measure insulation resistance. Especially, non-contact voltage phase detection techniques have been developed that can be applied in environments where it is difficult to find voltage measurement locations such as component receptors. The performance verification of the non-interrupting insulation resistance measuring devices has been tested against existing products using standard calibration equipment and test jigs. The validation confirmed performance within 2 % for direct contact type and within 10 % for non-contact type. In addition, the procedure to make continuous insulation test using the equipment was proposed.

• 한국안전학회지
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• 제7권4호
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• pp.7-12
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• 1992

The smouldering combustibility of cellulose insulation treated with boric acid-borax-aluminium sulfate as combustion retardants are examined by cigarette ignition method and electrical cardrige heater method. The effectiveness of Aluminium sulfate as a third combustion are acceptable both smouldering resistance and flame resistance at 18% level of all examined formulation. As the proportion of Aluminium sulfate in the formulation was increased, the flame resistance of cellulose insulation was improved.