• 대한치과보철학회지
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• 제49권1호
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• pp.22-28
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• 2011

연구 목적: 지르코니아 보철물을 위한 치아 형성이 실제 임상에서 어떻게 이루어지는지에 대해 조사하고 향후 치아 형성에 대한 교육 자료 및 추가 연구의 기초 자료로 활용하고자 한다. 연구 재료 및 방법: 지르코니아 치관 제작을 위해 milling center에 보내진 모형을 조사하여 Lava CAD/CAM System으로 스캔 한 후 'ImageJ' 프로그램 상에서 측정하여, 이를 비교 분석하였다. 각 치아마다 근원심면과 협설면에서의 축면 경사각을 측정하였다. 또한, 견치를 제외한 전치에서 절단연 0.4 mm 하방 부위의 bucco-lingual diameter 측정하였다. 결과 및 결론: 실험군 내에서 지르코니아 전부도재관을 위한 지대치의 축면 경사각은 $18.67^{\circ}$로 문헌에서 추천하는 각도 보다 크게 나타났다. 지르코니아 완전도재관의 지대치 형성 시 축면 경사각은 협설과 근원심면, 악궁 내 위치에 따라 차이가 있었다. Peak 0.4의 평균값은 1.18 mm로 밀링버의 최소직경을 고려한 요구조건인 0.8 mm 보다 큰 값으로 나타났다. 그러나 선각 부위 rounding 에 관한 추가적인 연구가 필요할 것으로 생각된다.

• 한국터널지하공간학회 논문집
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• 제17권4호
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• pp.473-485
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• 2015

디스크커터 내부부품의 손상과 관련된 원인은 씰(seal)부의 손상으로 인한 윤활유 부족, 토사 및 수분의 침투, 과부하, 과열, 조립문제, 소재문제 등이 있으며 손상 정도에 따라 디스크커터의 작동여부, 즉 회전이 가능한지가 나타난다. 따라서 디스크커터 회전문제에서의 핵심은 베어링의 작동여부라고 할 수 있다. 본 연구는 TBM의 굴착도구인 디스크커터의 재활용에 도움이 되고자 현장 적용된 디스크커터를 회수한 후 분해하여 내부부품을 조사하고 분석하였다. 그 결과, 허브의 부하영역에서의 스크래치는 재활용을 위해 가공작업이 필요한 것으로 나타났으며, 플로팅 씰의 래핑면과 오일상태는 재활용을 위한 성능파악에 필요한 시험으로 판단되었다. 특히 플로팅 씰은 베어링의 정상작동여부에 중요한 영향을 미치는 부품으로 파악되었다. 그 외의 베어링, 샤프트, 씰 리테이너에서는 특이사항이 없는 것으로 나타났다.

• 한국산업보건학회지
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• 제8권1호
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• pp.50-66
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• 1998

This study was conducted to estimate crystalline silica contents in airborne respirable dust from various manufacturing industries and to compare analytical performance of two methods of quantifying crystalline silica, X-ray diffraction(XRD) and Fourie transform infrared spectroscopy (FTIR). For this study, various manufacturing industries with a history of having pneumoconiosis cases and also known to generate dusts containing crystalline silica were investigated. These industries include: foundry, brick, potteries, concrete, and abrasive material, etc. Both personal and area respirable dust samples were collected using 10 mm, Dorr-Oliver nylon cyclone equipped with 37mm, $5{\mu}m$ pore size, polyvinylchloride (PVC) filters as collection media. In addition, total dust samples were collected side-by-side to the respirable samples. All samples were weighed before and after sampling and were pretreated according to the NIOSH sampling and analytical methods 0500, 7500, and 7602 for dust collection and quartz analysis. In addition, bulk samples were collected and analyzed by X-ray fluorescence (XRF) for minerals. In this article, only the results obtained from foundry are reported. The results from various other industries will be published in future articles. The respirable dust concentrations from personal samples by cyclone were $0.46-1.06mg/m^3$ and those from area samples were $0.34-0.73mg/m^3$. Dust concentrations of personal samples were significantly higher than those of area samples. The highest dust concentration was obtained from the personal samples of the finishing operation. Total dust concentration ranged $1.24-3.40mg/m^3$. The mean quartz contents estimated by FTIR and XRD in the personal respirable dust samples were 5.12% and 4.41%, respectively, without significant difference between them. For quartz analyses, the two techniques were highly correlated with $r^2$ ranged 0.803-0.920. But the results by FTIR were mostly higher than those by XRD. In addition, cristobalite was not detected by FTIR. Significant correlations between contents of crystalline silica and such minerals as $Al_2O_3$, CaO, $TiO_2$, and $K_2O$ suggest possible interferences from these minerals.

• 한국건설관리학회논문집
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• 제2권3호
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• pp.92-100
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• 2001

건설공사의 계약문서에는 설계도면, 공사시방서 등이 포함된다. 그러나 공사시방서의 경우 분서의 중요성만큼 활용되지 못하고 있다. 그 이유는 시발정보가 설계도면과 재료마감표등 다른 건축정보들과 관련되어 찾을 수 있게 되어있지 않아 활용도가 떨어진다. 따라서 다른 정보와 연관되어 질 수 있는 통합모델이 필요하고 이러한 통합모델을 바탕으로한 DB가 구축되어 져야 설계 및 시공, 유지관리시에 그 활용성이 증대된다. 이러한 통합모델의 구현은 부위를 사용함으로서, 설계도를 작성하고 그리고 부위 정보에 자재정보, 법규정보, 시방정보의 속성이 들어가 있다면 견적을 낼 수 있고 많은 정보를 참조할 수 있어 설계의 질이 향상될 것이다. 또한 유지관리시에도 설계정보에 법규, 자재정보, 시방정보가 들어가 있기 때문에 수선유지 및 하자보수등에 유용하게 사용된다. 설계단계에서부터 만들어진 시방정보 DB는 설계의 수정과 공사의 수정에 맞게 update 되어 져야 한다. 또한 시공현장이나 감리시에도 참고를 하기 위해서는 시방서가 web을 이용한 문서화가 되어 어디서든지 참조할 수 있는 환경이 되어 져야만 한다. 따라서 본 연구에서는 시방정보 구조화를 위한 부위분류 체계글 제시하고, 이를 바탕으로 하여 건축시방정보를 DB화하며, DB를 상호 참조할 수 있는 인터넷 환경에서의 시방정보의 검색 빛 작성이 가능하도록 하였다. 이 시스템을 활용하여 공사시방서출 작성, 참조함으로써 공사시방서의 활용의 향상이 기대되려 이를 통해 건설공사의 클레임 방지와 설계, 시공, 유지관리의 품질 향상이 기대된다. 또 발주기관, 설계용역업체, 공사현장 등의 실무에서 더욱 편리하게 정보를 활용할 수 있을 것으로 사료된다.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2017년도 춘계학술대회 논문집
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• pp.77-77
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• 2017

Titanium and its alloys offer attractive properties in a variety of applications. These are widely used for the field of biomedical implants because of its good biocompatibility and high corrosion resistance. Titanium anodizing is often used in the metal finishing of products, especially those can be used in the medical devices with dense oxide surface. Based on SAE/AMS (Society of Automotive Engineers/Aerospace Material Specification) 2488D, it has the specification for industrial titanium anodizing that have three different types of titanium anodization as following: Type I is used as a coating for elevated temperature forming; Type II is used as an anti-galling coating without additional lubrication or as a pre-treatment for improving adherence of film lubricants; Type III is used as a treatment to produce a spectrum of surface colours on titanium. In this study, we have focused on Type II anodization for the medical (dental and orthopedic) application, the anodized surface was modified with gray color under alkaline electrolyte. The surface characteristics were analyzed with Focused Ion Beam (FIB), Scanning Electron Microscopy (SEM), surface roughness, Vickers hardness, three point bending test, biocompatibility, and corrosion (potentiodynamic) test. The Ti-6Al-4V alloy was used for specimen, the anodizing procedure was conducted in alkaline solution (NaOH based, pH>13). Applied voltage was range between 20 V to 40 V until the ampere to be zero. As results, the surface characteristics of anodic oxide layer were analyzed with SEM, the dissecting layer was fabricated with FIB method prior to analyze surface. The surface roughness was measured by arithmetic mean deviation of the roughness profile (Ra). The Vickers hardness was obtained with Vickers hardness tester, indentation was repeated for 5 times on each sample, and the three point bending property was verified by yield load values. In order to determine the corrosion resistance for the corrosion rate, the potentiodynamic test was performed for each specimen. The biological safety assessment was analyzed by cytotoxic and pyrogen test. Through FIB feature of anodic surfaces, the thickness of oxide layer was 1.1 um. The surface roughness, Vickers hardness, bending yield, and corrosion resistance of the anodized specimen were shown higher value than those of non-treated specimen. Also we could verify that there was no significant issues from cytotoxicity and pyrogen test.

• 패션비즈니스
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• 제1권2호
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• pp.46-54
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• 1997

The purpose of this study is to understand women's wear manufacturing industries. First, the study was to investigate the present production systems and how much the automatic facility are by comparing them. This study enhanced more efficient, stable, and suitable work line. This intern will direct the way in which automatic facilities will be created. Second, through this study on the general character of the inspectors, the ratio of impaired goods, and the reasons for unsatisfactory goods, I intended to find out a way to decrease the impaired goods and to produce competitive and high quality goods. The results of the survey can be summarized as follows; 1. The result of the research on the automatic industrial facilities shows that the majority of the factories (77.4%) are 40% below the automatic facility rate. The reasons for this according to order are that was a deficit in money, no reason for expensive machines, and lack of the technique and the number of workers required to handle the machines. 2. At this time, the most required equipments are shown according to its importance; automatic sewing machine, automatic cutting machine, automatic spreading machine, and finishing & pressing machine. So in the women's wear manufacturing industries, they think that they need more automatic cutting machine, automatic spreading machine in the cutting field rather than high price automatic machine in the sewing field such as pattern former, pocket welting, automatic sleeve connecting machine and automatic label connecting machine. 3. The result of the research in the goods quality shows that the average impaired rate is 12.7% at the first inspection. In addition the average rate for complete impaired rate is 1.52%. The line system shows that it has a impaired rate that is double the rate of the pair system. Because of this, the industries plan to combine the line system and pair system to create an improved and suitable production system which can boost the quality and productivity of the goods. 4. The fabric is the main point of the impaired goods. The factors of the impaired goods in manufacturing are the lack of mental abilities of the worker, impaired fabrics and a lack of cooperation in the working system. Furthermore, there is a lack of technique for new material. 5. To prohibit impaired goods in manufacturing, there need to be a way to educate the workers and to enhance the workers' mind on the productive goods. Also there need to increase in the investments of automatic production machines. Finally there need to be a standardized working line. Therefore, there need to be an improvement on the management of the production of goods, the development of technique and an increase in the education for the workers, with this there will be a decrease in impaired goods, and an increase in better quality of goods to enforce the domestic apparel industries.

• 보존과학회지
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• 제29권1호
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• pp.81-92
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• 2013

과거 국내 사찰벽화 보존처리는 유공성과 친수성의 특성을 고려한 재료선정이나 적합성에 대한 연구가 미흡한 상황에서 유럽의 재료 및 공법이 적용되었다. 그리고 합성수지를 사용하여 채색층 고착처리가 이루어진 벽화들은 현재까지 만족스럽지 못한 결과들이 나타나고 있다. 따라서 본 논문에서는 보존처리 효과를 규명하고자 사찰벽화 채색층 보강에 사용되는 고착제를 선별하여 고착처리 적용연구를 실시하였다. 고착제의 점도와 접착력 그리고 침투상태의 관계성을 파악한 결과 대부분 점도가 높은 시료에서 접착력이 증가하였고, 저점도의 시료에서는 접착력이 낮게 측정되었다. 시료별 고착제의 침투상태는 유사하지만 채색층과 토양 마감면의 상응 및 결합반응은 큰 차이점이 있는 것을 발견할 수 있었다. 동물성 아교와 MC의 경우, 채색층을 포함하여 토양과의 고착반응이 우수한 것으로 보이며, 토양과 견고하게 결속되어 안정적인 고착효과를 나타내는 것으로 판단된다. 합성수지계인 PVAc와 아크릴수지는 침투는 원활하지만, 토양과의 고착반응은 효과가 떨어지는 것으로 보인다.

• 한국염색가공학회지
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• 제26권1호
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• pp.45-52
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• 2014

Red pine (Pinus densiflora) is widely used traditional medicine, pharmacological and nutritional values from which the phytochemical compounds are derived. The present study was aimed to examine the antibacterial effects in the absence and presence of a immature red pine cone extract against 13 microorganisms. The components in the aqueous extract from immature red pine cone were identified by GC-MS. About 1.4% of total polyphenolic compound was measured in aqueous extract collected from immature red pine cone. Also, the high concentration of ${\beta}$-phellenandrene, ${\alpha}$-pinene, limonene, bornyl acetate and aldehyde was detected in total ion chromatograms. Of total 13 microorganisms, 4 microorganisms including Pseudomonas aeruginosa, Vibrio cholera, Listeria monocytogenes, Klebsiella pneumonia were effectively killed by aqueous extract of immature red pine cone. The highest anti-bacterial effect was detected in P. aeruginosa, followed by V. cholera, L. monocytogenes and K. pneumonia. In case of P. aeruginosa, the largest diameter of inhibition zone was maintained to 1/2 solution treated cells and slightly decreased at 1/4 and 1/8 solution treated cells. Also, in test used V. cholera and L. monocytogenes, the inhibition zone was strongly formed in only 1 and 1/2 solution treated cells, while K. pneumonia showed the very small diameter of inhibition zone in all concentrations. Therefore, these results suggested that the aqueous extracts of immature red pine cone should be considered as a new and potentially important anti-bacterial substrate to effectively prevent the microbial infection and penetration.

• 한국의류학회지
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• 제28권5호
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• pp.582-590
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• 2004

The purpose of this study was to evaluate thermal properties of Taekwondo wears with three different materials. As a begging step, the questionnaire survey about the actual condition of Taekwondo wears was conducted. With the results of the questionnaire, cotton/nylon(70/30) blended fabric(CN) that was newly woven with sweat absorbent finishing and cotton/spandex(95/5) blended fabric with flexibility property were developed. The same designed 3 Taekwondo wears with 3 different materials which were two different materials(CN and CS) and a current material(cotton/PET, CP) were made. Four young males volunteered for this study, they kicked and punched as Taekwondo action for 20 minutes. Mean skin temperature was the highest in CS(33.1${\pm}$0.8$^{\circ}C$) and the lowest in CP(32.7${\pm}$0.6$^{\circ}C$). Increasing degree of rectal temperature didn't show any significant difference. Clothing microclimate temperature on the thigh was higher in CS(32.8${\pm}$17.4$^{\circ}C$) than in CN(29.4${\pm}$1.1$^{\circ}C$) and CP(29.4${\pm}$1.0$^{\circ}C$). Clothing microclimate temperature on the back and humidity on the thigh didn't show any significant differences. Clothing microclimate humidity on the back was higher in CP(65${\pm}$20%RH) than in CS(61${\pm}$17％RH). Heart rate, total body weight loss, and local sweating were not significantly different by materials. Most subject responded more hot in CN than in others, but there were no significant differences at the subjective sensation of thermal humidity. They answered more comfortable in CN than in others. Tectile sensations were the best in CN and the worst in CS. From those results, first of all, it is necessary to be weighted on Taekwondo wears made of CN in the aspects of the dignity of military arts uniform. Secondly, CS was required to be lighted and enhanced for the subjective sensation. Third, CP weaved honey comb was asked more various design to eliminate sweat high competition power within the scope of the dignity of military arts uniform.

• 한국건축시공학회지
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• 제11권6호
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• pp.587-596
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• 2011

폴리머 시멘트 모르타르를 긴급공사의 보수 보강 재료로 사용할 때, 초속경시멘트와 혼입하여 사용함으로써 시멘트의 빠른 응결과 시멘트 매트릭스 내부에서 형성된 폴리머 필름의 작용이 물리적 성질과 내구성을 개선시킬 수 있다. 또한 각종 혼화재료를 혼입함으로써 매트릭스 내부 공극을 충전하여 성질을 개선시킬 수 있는데, 양생방법이 큰 영향을 미칠 수 있다. 본 연구에서는 속경성 SBR 시멘트 모르타르의 압축강도와 휨강도에 영향을 미칠 수 있는 혼화재료와 양생조건에 관하여 실험을 실시하여 그 영향성을 평가하고자 하였다. 본 연구결과, 초속경시멘트 모르타르에 SBR을 혼입함으로써 휨강도와 압축강도가 크게 개선되었으며, 여기에 메타카올린을 혼입함으로써 보다 더 강도를 증진시킬 수 있었다. 또한 양생방법에 있어서도 SBR을 사용한 경우에는 표준양생에서, SBR을 사용하지 않은 경우에는 수중양생에서 강도발현이 크게 나타났다.