• Journal of Power System Engineering
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• v.17 no.2
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• pp.108-113
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• 2013

In this study, lightweight aggregate was made from basalt stone powder sludge. Clay and glass powder were respectively added from 0 to 20 wt% and from 0 to 100 wt%. The glass powder helped to form glassy phase which trapped generating gas in the materials. $CaCO_3$ helping bloating process was added from 0 to 10 wt%. It was possible to produce lightweight aggregate at range from $1150^{\circ}C$ to $1200^{\circ}C$. The specimen was heated in furnace at 1100, 1150 and $1200^{\circ}C$ for 15 min, respectively, to sinter aggregates. Chemical composition of materials were determined, and characteristics were analyzed, including specific gravity, water absorption. Lightweight aggregate which was heated at $1200^{\circ}C$ had specific gravity of $0.53g/cm^3$, water absorption of 3.08%, and this value satisfied KS L 8551 standard.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.17 no.1
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• pp.122-129
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• 2018

This study conducted a seismic qualification analysis of small savonius style vertical axis wind turbine(VAWT) using finite element method(FEM). The modal analysis was performed on the wind turbine structure to check the occurrence of resonance caused by the rotation of gearbox and windmill blades. Next, it conducted a seismic response spectrum analysis due to horizontal and vertical seismic load of required response spectrum of safe shutdown earthquake with 5 % damping(RRS/SSE 5%) of KS C IEC 61400 and conducted a static analysis due to deadweight and wind load. The total maximum stress of the VAWT structure was calculated by adding the maximum stresses due to each load case using the square root of the sum of the squares(SRSS) method. Finally, the structural safety of the VAWT structure was verified by comparing the total maximum stress and the allowable stress.

• Journal of the Korea Safety Management & Science
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• v.17 no.4
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• pp.397-401
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• 2015

In this study, analysed the characteristics of power drop and surface damage in solar cell through high temperature and humidity test in the 3 case of EVA(ethylene vinyl acetate) and 2 case ribbon thickness. The solar cells were tested during the 500hr in $85^{\circ}C$ temperature and 85% relative humidity conditions, that excerpted standard of PV Module(KS C IEC-61215). Through the EL(Electroluminescence) shots, specimen's surface have partialy damaged. Before and after high humidity and high temperature test, ribbon thickness $200{\mu}m$ EVA1 case power drop rate was 8.463%, EVA2 case was 6.667%, EVA3 case was 6.373%. In the ribbon thickness $250{\mu}m$ EVA1 case power drop rate was 6.521%, EVA2 case was 8.517%, EVA3 case was 6.019%. EVA3 case was the lowest power and FF(fill factor) drop rate at the 2 case of ribbon thickness, because EVA3 is laerger than EVA1 and EVA2 in thickness, elongation and tensile strength.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.17 no.3 s.120
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• pp.226-234
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• 2007

This study aims to evaluate noise emission from water supply and drain installations in apartment bathroom. These noise were one of the most annoying noise sources in apartment houses. Especially, drain plumbing system have used bellow bathroom ceiling, it was very discomfort to hear the noise in bellow apartment. Noise of closets and faucets were measured which were main noise source, then these noise were evaluate and analyzed the emitting characteristics varying the supplying water pressure. As increasing the water pressure, also total noise level of the water supplying stool noise and faucet noise were increased. Especially the water closet showed remarkably the increasing noise level in middle and high frequency bandwidth, while the noise level of faucets increased in $50\;Hz{\sim}250\;Hz$ of low frequency bandwidth. Vortex closet were favorable to syphon closet, and lever faucet were favorable to conventional lavatory faucet on reducing the noise. Above these results could be used in basic data establishing KS (Korean Standard) for evaluation and rating procedure and measures reducing these noise.

• Journal of the Korea Fashion and Costume Design Association
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• v.25 no.3
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• pp.17-29
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• 2023

This study collected and analyzed reference information on the size labeling method and size of clothing products in 13 online shopping malls for plus size women in their 20s and 30s, and compared the size specification information focusing on jeans. First, in the results of examining the method of clothing size designation, clothing sizes indicated by 1, 2, 3 or physique designation (M, L, XL) differed between shopping malls, and even in the same shopping mall, even if the same size notation was used. Most the clothing sizes were different depending on the type of clothing. For bottoms, it was found that one company used seven size designation methods at the same time, two shopping malls used four size designation methods, and five shopping malls used three size designation methods. In the meantime, in the results of comparing the size specifications of jeans XL (size 88, 32 inches) by product part, for waist and hip circumferences, each of the eight companies showed that the size was smaller than the body size suggested by KS adult women's wear.

• Journal of the Korea Concrete Institute
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• v.17 no.5 s.89
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• pp.785-792
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• 2005

This study is to examine the influence of defective grain shape of coarse aggregate and lowered fineness modulus of fine aggregate on the characteristics of high flowing concrete. The flow ability and compact ability of high flowing concrete was examined using fine aggregate, varying its fineness modulus to 2.0, 2.5, 3.0, and 3.5, and coarse aggregate with before and after grain shape improvement. Also the influence of fineness modulus of fine aggregate and grain shape of coarse aggregate on dispersion distance of particles of aggregate was examined by relatively comparing the dispersion distance between particles of aggregate. According to the experimental result, minimum porosity when mixing fine aggregate and coarse aggregate was shown in order of fineness modulus of fine aggregate, 3.0, 2.5, 2.0, 3.5, regardless of the improvement of grain shape. So when the fineness modulus is bigger or smaller than KS Standard $2.3\~3.1$, the porosity increased. When the spherical rate of the grain shape of coarse aggregate unproved from 0.69, a disk shape to 0.78 sphere shape, the rate of fine aggregate, which represents minimum porosity, decreased $6\%$ from $47\%\;to\;41\%$. The 28 days compressive strength according to fineness modulus of fine aggregate increased about 3 ma as the fineness modulus increased from 2.0 to 2,5, and 3.0. However, the 28 days compressive strength decreased about 9 ma at 3.5 fineness modulus as compared with 3.0 fineness modulus. The improvement of grain shape in coarse aggregate and increase of fineness modulus in fine aggregate made the flow ability, compact ability, and V-rod flowing time improve. Also the fineness modulus of fine aggregate increased the paste volume ratio when a higher value was used within the scope of KS Standard $2.3\~3.1$.

• Journal of KSNVE
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• v.8 no.6
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• pp.1078-1085
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• 1998

This study is carried out to investigate the characteristics of sound insulation performances for masonry walls. PC walls and ALC walls. For these purposes. 17 types of masonry walls were selected and tested in accordance with KS F 2808 at reverberation room The sound insulation performance of 8" cement block walls are graded with D-45 ∼ D-55 which are to be evaluated very favorable grade. 4" cement block walls are D-30 ∼ D-40. 1 B cement brick walls are D-40∼D-50 favorable grade. 0.5 B brick walls are D-30∼D-45. 150 mm PC wall is D-50. and ALC walls(150 mm, 200 mm) are D-30∼D-45.

• Journal of Korean Institute of Industrial Engineers
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• v.41 no.1
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• pp.17-24
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• 2015

Mixed acceptance sampling plans for quantity of products in prepackages are widely used for compliance testing. To pass testing, random samples jointly comply with two legal requirements: (i) the average net content of an inspection lot shall be not less than the labelled quantity and (ii) the numbers of under-filled prepackages in a sample are less than or equal to permitted numbers. This paper discusses some drawbacks of the acceptance sampling plans and requirements recommended in OIML R87 (KS A 50087 translated by Korean) developed by the International Organization of Legal Metrology and evaluates the producer's and consumer's risks. In addition, problem of determining a target value in filling processes of prepackages under the OIML R87 requirements is addressed and illustrated with a numerical example.

• 월간 기계설비
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• s.288
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• pp.75-80
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• 2014

나사식 가단주철제 관이음쇠는 신한메탈, 영화테크(전신 영화금속) 외 국산 8개사, 중국산 9개사 등 모두 17개사가 공급에 참여하고 있다. 그러나 심한 가격경쟁으로 짝퉁과 중국산 제품이 판치는 시장에서 100% 국내 가공으로 최고의 품질을 자랑하며 고객과 신뢰를 쌓아가기란 여간 어렵지 않다. 나사식 가단주철제 관이음쇠 분야의 명품을 꼽으라면 설비건설업계는 대부분 다이아몬드가 표시된 제품을 집는다. 다이아몬드 표시로 더 알려진 관이음쇠 생산업체인 (주)신한메탈(대표 전진화)은 작년에 영화금속의 나사식 관이음쇠 부문을 인수한 후 경쟁력을 더욱 강화한데 이어 최근에는 엘보, 티 등 스테인리스 조인트 가공시장에 본격 진출하기 위해 생산시설 도입에 박차를 가하고 있다.

• Journal of Welding and Joining
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• v.21 no.2
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• pp.64-69
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• 2003

The bonding phenomena and mechanical property of duplex stainless steel during brazing have been investigated. The UNS32550 was used for base metal, and the MBF50 was used for insert metal. Brazing was carried out under the various conditions (brazing temperature : 1473K, 1498K, holding time : 0∼1.8ks). There were various microconstituents in the bonded interlayer because of reaction between liquid insert metal and base metal. In the early stage of brazing, BN is formed in the bonded interlayer and base metal near the bonded layer. Cr made is formed in the bonded interlayer. The amount of BN and Cr nitrides decrease with the increase of bonding temperature and holding time. Superior shear strength of 550MPa is obtained by restraining the formation of nitrides. (Received January 17, 2003)