• 대한기계학회논문집A
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• 제36권10호
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• pp.1221-1226
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• 2012

핫 스탬핑은 오스테나이트 변태 온도 이상에서 프레스 성형 후 급속히 냉각되는 고강도 부품을 제조하는 성형 방법이다. 매우 적은 양의 보론 성분을 가지고 있는 보론강은 핫 스탬핑에 사용되는 재료 중의 하나이다. 본 연구의 목적은 열처리 조건에 따르는 기계적 성질과 에릭슨 커핑 시험에 의하여 성형성을 조사하는 것이다. 다양한 온도에서 다이��칭은 대기 시간을 달리하여 실시하였다. 1173 K-0s에서 ��칭 후 TWB는 1203 MPa의 인장 강도를 얻었다. 이것은 모재 인장강도(1,522 MPA)의 79 %이다. 금형 온도(298, 523, 673 K)에 따른 보론강 TWB의 성형성은 차이가 크지 않았다. 그러나 성형 속도가 증가함에 따라 성형성이 감소하는 것을 확인할 수 있었다.

• 대한치과기공학회지
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• 제42권3호
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• pp.202-207
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• 2020

Purpose: This study is a comparative analysis of the strain according to deposition in a constant temperature water bath after manufacturing ultraviolet (UV)-cured artificial teeth. Methods: As a control group, 10 ready-made artificial teeth were selected as the first molar on the right side of the maxilla (RT group). Silicone was used as a duplicate of the artificial denture teeth. Experimental teeth were prepared in two groups using the prepared silicone mold. In the first experimental group, the UV-cured resin was injected into the negative silicone, followed by irradiation with a UV-curing machine for 5 minutes (5M group). In the second experimental group, the UV-cured resin was injected into the negative silicone, and then irradiated for 30 minutes using a UV-curing machine (30M group). The one-way ANOVA was performed, and post-test was analyzed by Tukey. Results: When immersed in a water bath for 15 days, it was found to be -0.3% in the RT group, -0.6% in the 5M group, and -0.7% in the 30M group. The results revealed -0.2% in the RT group, 0.2% in the 5M group, and -0.2% in the 30M group when they were in the bath for 30 days. Conclusion: In the water bath, the swelling was greater when deposited for 1 to 15 days, but was less when deposited for 15 to 30 days.

• 한국의류산업학회지
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• 제21권4호
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• pp.480-487
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• 2019

This study used 3D technology to develop a multi-functional sports brassiere with increased comfort and fit that can be worn as a base layer during exercise or as underwear. A 75A size industrial lingerie figure was used to develop a standard pattern. 3D tools for scanning and pattern making, such as Vivid 910, Geomagic Design X, 2C-AN and Yuka CAD were used. The sports brassiere was designed as a tank top style with dual structure and linings attached to a pad utilized with a sport brassiere mold cup. 3D outer and lining's pattern was differently developed in consideration of the body's curvature with pad's shape and structure. Shoulder and neck part reduction rates were adjusted to increase the neck areas fit that considered the nude pattern's structure due to uncomfortableness felt by wearers who were uncomfortable with the neck areas fit on existing brand products. The reduction rate was also set differently on each part. For example, the reduction rate on outer side panel was set strongly to increase the breast's volume. Two products, developed by a 3D sports brassiere and previously released product, were worn on 8 subjects in their 20's to evaluate fit, comfort, and purchase preferences. The evaluation proved that newly developed 3D products were superior to comparative products. The results of the clothing pressure measurement indicate that the newly developed sports brassiere's front part had less pressure on upper bust and shoulder areas compared to comparative products as well as showed less pressure on the back side, which shows improved wearing comfort compared to comparative products.

• 융합정보논문지
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• 제9권4호
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• pp.8-13
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• 2019

본 논문은 지역의 문화콘텐츠의 제작기술과 인프라를 기반으로 스토리텔링 중심의 캐릭터 브랜드 상품의 부재로 인하여 지역 문화자원의 재구성 및 상품화가 필요하다고 판단되어 전통적 문화소재인 캐릭터를 발굴하여 문화산업 기념품으로 개발하였다. 스토리텔링 기반의 캐릭터 상품 개발에 대한 차별화 전략을 통해 발전된 사업기반을 확립할 수 있는 토대가 되어, 다양한 콘텐츠 제작의 밑거름과 더불어 발전된 도예 상품들의 공급 확대에 기여할 것으로 보여 진다. 또한, 수작업 기반의 제작으로 인해 소량 생산만 가능하고 제작기간이 길어지는 반면 3D 프로그램 및 3D 프린팅을 통한 목업 제작으로 석고 틀 제작 기간이 단축되었으며, 대량생산의 발판이 마련되어 기존의 전통적인 도자기 인형에서 벗어나 다양하고 풍부한 도자기 제품 개발에 효과가 있었다.

• 대한치과기공학회지
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• 제42권4호
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• pp.355-361
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• 2020

Purpose: In this study, we added two kinds of photoinitiators (CQ and TPO) to prepare two kinds of denture base resins (Bis-GMA series and UDMA series) for three-dimensional (3D) printing to compare and analyze their mechanical and biological properties and to find the optimal composition. Methods: Control specimens were made using the mold made of polyvinyl siloxane of the same size. Light curing was performed twice for 20 seconds on both the upper and lower surfaces with LED (light emitting diode) light-curing unit (n=10). Experimental 3D printing dental resins were prepared, to which two photoinitiators were added. Digital light processing type 3D printer (EMBER, Autodesk, CA, USA) was used for 3D printing. The specimen size was 64 mm×10 mm×3.3 mm according to ISO 20795-1. The final specimens were tested for flexural strength and flexural modulus, and MTT test was performed. Furthermore, one-way analysis of variance was performed, and the post-test was analyzed by Duncan's test at α=0.05. Results: The flexural strength of both Bis-GMA+CQ (97.12±6.47 MPa) and UDMA+TPO (97.40±3.75 MPa) was significantly higher (p<0.05) in the experimental group. The flexural modulus in the experimental group of UDMA+TPO (2.56±0.06 GPa) was the highest (p<0.05). MTT test revealed that all the experimental groups showed more than 70% cell activity. Conclusion: The composition of UDMA+TPO showed excellent results in flexural strength, flexural modulus, and biocompatibility.

• 한국수산과학회지
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• 제55권3호
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• pp.267-277
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• 2022

This study investigated changes in the physicochemical and microbiological properties of fermented fish sauces based on the pacific sand lance Ammodytes personatus during fermentation according to rice koji treatments and salt contents. In total, six fish sauces were prepared, with rice koji treatment for 24 or 72 h before salt addition, and salt contents of 10 or 20%, including two controls to compare the response to different salt contents without koji treatment. The initial pH values of the sauces with koji treatments were notably lower than those of the controls. Over the 10 months of fermentation, the amino nitrogen contents of the sauces with 10% salt were higher than those with 20% salt, while the volatile base nitrogen value was also increased. In the microbial community, the initial numbers of lactic acid bacteria and mold were higher in the sauces with koji treatment than in the controls. After 8 months of fermentation, the free amino acid and organic acid contents were higher in the sauces with koji treatment than in the controls. Although the fermentation rate was affected to a greater extent by salt contents, the rice koji treatment also exerted a positive effect on the acceleration of fermentation.

• Geomechanics and Engineering
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• 제27권6호
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• pp.537-550
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• 2021

There are various technical problems need to be solved in the construction process of pre-setting an isolation wall into a double lane in the outburst prone mine. This study presents a methodology that pre-setting an isolation wall into a double lane without a coal pillar. This requires the excavation of two small section roadways to dig a wide section roadway, followed by construction of the separation wall. During this process the connecting lane is reserved. In order to ensure the stability of the separation wall, the required bearing capacity of the isolation wall is 4.66 MN/m and the deformation of the isolation wall is approximately 25 cm. To reduce the difficulty of implementing support the roadway is driven by 5 m/d. After the construction of the separation wall, the left side coal wall is brushed 1.5 m to make the width of the gas roadway reach 2.5 m and the roadway support utilizes anchor rod, ladder beam, anchor cable beam and net configuration. During construction, the concrete pump and removable self-propelled hydraulic wall mold are used to pump and pour the concrete of the isolation wall. In the process of mining, the stress distribution of coal body and isolation wall is detected and measured on site. The results demonstrate that the deformation of the surrounding rock of roadway and separation of roof in the roadway is small. The stress of the bolt and anchor cable is within equipment tolerance validating their selection. The roadway is well supported and the intended goal is achieved. The methodology can be used for reference for similar mine gas control.

• 한국산업융합학회 논문집
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• 제26권2_2호
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• pp.341-347
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• 2023

The subway is one of the most common and important means of transportation in modern society. In order to use the subway safely, tracks are necessary, but trains are prone to derailment and collisions. In order for the train to run safely on the track, the fishplate that connects the line connection is used. The damaged railway was a fishplate for connecting subway lines used for 11 years, and damage analysis and countermeasures were presented. Beach marks were observed on both fracture surfaces, and striations appeared at the range of crack propagation. The damaged part is Cr carbide, which has a higher hardness than the base metal, and is judged to be embrittled and destroyed by fatigue. The SM50C fishplate was subjected to a cyclic stress of about 59% of the upper limit of tensile-compression fatigue limit, but inclusions were the cause of failure. In order to prevent fatigue failure of the SM50C steel fishplate, the occurrence of inclusions should be minimized and processed to have a homogeneous structure when manufacturing the fishplate. In addition, compressive residual stress is given through surface modification such as peening to control crack generation. It is necessary to minimize the change in shape that can become a stress concentration part along with accurate fastening of the bolt, and to design the stress distribution to be as uniform as possible.

• 한국식품영양학회지
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• 제25권3호
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• pp.460-482
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• 2012

한국고전종합 데이터베이스(http://db.itkc.or.kr/itkcdb/mainIndex Iframe.jsp)와 조리서를 통하여 고려시대(918~1392) 및 조선시대(1392~1897) 문헌에 실린 장류와 조리서에 실린 장류를 비교분석하였다. 고려시대의 장류는 문집에 15종류로 그중 장(6), 염장 염시(2), 겨자장(1) 등이 있으나, 조리서는 남아있지 않다. 고려 조정에서는 장을 굶주린 사람들에게 주어 구제하였다. 조선시대의 장류는 문집에 111종류, 조리서에 153종류가 있었다. 일반장류는 문집에 53종류로 그중 장(204), 염장(63), 초장 구장(7), 겨자장(6) 등이 있고, 조리서에는 55종류로 숙황장(9), 대맥장 면장 생황장 유인장(8) 등이 있는데, 그중 13종류가 중국계이다. 간장은 문집에 9종류로, 수장(30, 청장(23), 감장(8), 간장(3) 등이 있고, 조리서에는 12종류로 청장(10), 천리장(4), 간장(3) 등이 있다. 고추장은 문집에 9종류로 초장(12), 고초장(3) 등이 있다. 조리서에는 9종류로 고초장(7), 만초장 급조만초장(4) 등이 있다. 육류장은 문집에 16종류로 해장(15), 혜장 육장(11) 등이 있고, 조리서에는 22종류인데 계란장 및 알장(9), 게장(6), 육장(5), 쇠고기장(4) 등이 있다. 시류(청국장)는 문집에 18종류로, 염시(40), 시(35), 시장(6) 등이 있고, 조리서에는 19종류로 전시전 국장(6), 시 수시장(4)이 있는데 그중 11가지가 중국계이다. 집장은 문집에 6종류로 집장(7), 읍장(4), 포장 장즙(2) 등이 있고, 조리서에는 15종류로 집장(9), 즙저(7), 하절집장(5) 등이 있다. 구황장은 문집에 없으나 나라에서는 일반 장을 구제용으로 사용하였다. 조리서의 구황장은 21종류로 포장(7), 급조청장(6), 사삼길경장(4) 등이 있다. 문헌과 조리서에 모두 있는 장은 건장, 난장, 두장, 말장, 면장, 소두장, 육장, 장이다. 중국계장은 일반장류 조리서와 시류 조리서에만 있고 문집 등의 문헌에는 없으므로 중국계 장류는 일반 백성들에게 전파되지 않은 것으로 나타난다.

• 보존과학회지
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• 제34권6호
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• pp.595-604
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• 2018

종이 공예 및 한지 산업, 문화재 보존 등에 활용을 위한 천연 바이오 접착제를 개발하기 위해 해초류 중 갈조류, 홍조류의 복합 다당류를 추출하여 이를 접착 성분으로 사용하였다. 갈조류는 감태, 다시마, 대황, 미역, 홍조류는 도박, 우뭇가사리, 풀가사리, 후노리로 갈조류와 홍조류에 포함된 비수용성 Ca 착물 형태의 다당류를 수용성의 1 가 알칼리 금속이 포함된 수용성 다당류들로 변형하여 추출하고 알코올 침전을 이용하여 다당류만을 얻고자 하였다. 갈조류는 다시마의 접착 인장 강도가 21.58 kgf, 홍조류는 도박이 32.99 kgf를 나타내어 물풀(18.45 kgf)과 딱풀(20.45 kgf)로 알려진 고체풀의 접착력에 상회하는 결과를 나타내었다. 이 추출된 다당류들은 추출 환경에 따라서 추출 수율이 결정되었지만, 접착도에는 차이를 나타나지 않고 있어서 추출 환경이 아니라 생육 환경에 의해 다당류의 형태가 결정되어지는 것을 알 수 있었다. 추출 시에 다단계의 알코올 침전법을 사용함으로 추출 과정에서 단백질 및 기타 다당류를 제외한 구성 성분들이 제거된 결과가 나타나서 곰팡이 배양이 되지 않는 안정한 결과를 보이고 있었으며, 단순 용해에 의한 접착제 제작 후에도 곰팡이의 발생이 없어서 친환경 접착 재료로서의 사용이 가능한 결과를 나타내었다.