• 한국산업보건학회지
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• 제28권1호
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• pp.91-99
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• 2018

Objectives: From a policy perspective, the introduction of confidential information reviews is a vital task for expanding workers' right to know and improving hazardous materials information communication. In this study, rational methods for introducing and administering confidential information reviews were examined as a part of advancing chemical information communication. Methods: The domestic status, social demands, and control cases from other countries about confidential information in material safety data sheets(MSDSs) were all examined. Additionally, principles for introducing MSDS confidential information review, what needs to be revised prior to its introduction, and procedures and manners of reviewing confidential information were suggested. Results and Conclusions: When composition information on MSDS needs to be protected in the EU and Canada, confidential information should be claimed and then approved by competent authorities with a principle of reviewing confidential information prior to rescinding information from MSDS. Applying the same principle, certain information on an MSDS that needs to be protected should be reviewed and approved in Korea. As a result, the MSDS is communicated with approval numbers replacing composition information. MSDS confidential information review has five steps, including deciding whether chemicals claimed to be confidential are excluded from applying for a confidentiality exemption, the names and concentration ranges of ingredients are adequate, and the claimed information is valid in terms of confidentiality.

• 대한음성언어의학회:학술대회논문집
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• 대한음성언어의학회 2003년도 제19회 학술대회
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• pp.180-180
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• 2003

Objectives : Vocal fold augmentation by injectable material under direct visual control is an easy and simple operation. However, when autologous fat or bovine collagen is used, resorption creates a problem. And autologous fascia is debating about absorption now days. This study is to evaluate the histology of minced and injected autologous auricular cartilage and fat graft in the augmentation of unilateral vocal fold paralysis using a canine model. Methods : Nine dogs were operated. At first, a piece of auricular cartilage was harvested from ear and minced into tiny chips with a scalpel. And also, a piece of fat tissue was harvested from inguinal area and minced into tiny chips with a scalpel. Cutting off a section of the recurrent nerve paralyzed the right vocal fold. The minced cartilage and fat-paste (0.2ml) was injected using a pressure syringe into the paralyzed thyroarytenoid muscle under direct laryngoscopy. Two animals were sacrificed at 3 days, three at 3 weeks, two at 3 months, one at 6 months, one at 12 months. Each dog underwent laryngectomy and serial coronal sections of paraffin blocks from the posterior part of the vocal fold were made. Results : There was no significant complication perioperatively and during follow-up. There was acute inflammatory findings in the graft at 3 days and 3 weeks. The injected cartilage remained in the larynx until 12 months. Conclusion : The autologous auricular cartilage graft is well tolerated and may be very effective material for volumetric augmentation on paralyzed vocal cord.

• 한국철도학회논문집
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• 제9권6호
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• pp.644-651
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• 2006

An application of concrete track is being actively processed for the construction of Korean railroad. The concrete track has an advantage to decrease the maintenance ire, but is very difficult system to maintain after earthwork settlement occurred. Therefore, the management and control of embankment and foundation settlement is very important for the successful concrete track construction. We expect that the main part of the settlement of the concrete track is the one of embankment and foundation supporting it. Settlements vulnerable to the concrete track among the causes of lots of settlements are primary consolidation and secondary compression settlement of foundation, creep settlement of embankment, settlement caused by train load, and unequal settlement resulting from the difference of embankment material and construction process. This paper investigated the settlement causes to make badly effects on the concrete track and also evaluated the settlement with field tests and numerical analysis.

• 한국주조공학회지
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• 제28권2호
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• pp.79-84
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• 2008

Metal foam is one of the most interesting materials with various multi-functional properties such as light weight, energy absorption, high stiffness and damping capability. Among them, energy absorption property has keen interests in the field of automotives for passenger protection. Nowadays, researches about pore size and porosity control of the foam are increased to correspond them. However, though energy absorption properties are improved, these results are not cost-effective process. In present research, however, as a part of improving the energy absorption property of metallic foams, 606X aluminum alloy was used for cell wall material which has higher strength than pure aluminum. And its morphological features are characterized. As a results, porosity and pore size are uniformity distribution with increasing foaming temperature in the case of 6061 alloy foams. 6063 alloy foam specimens have opposite tendency because of the influence of alloying element and viscosity of the molten melt.

• 대한화장품학회:학술대회논문집
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• 대한화장품학회 2003년도 IFSCC Conference Proceeding Book II
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• pp.464-478
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• 2003

Free radicals and reactive oxygen species (ROS) caused by UV exposure or other environmental facts play critical roles in cellular damage and aging. The extract of tinged autumnal leaves of maple tree(Acer palmatum) has proven to be a powerful antioxidant. The Acer palmatum extract is very effective on the stabilization of biological membranes( containing unsaturated fatty acid). We studied photoprotective effect of the extract against UVB-induced cytotoxicity in human keratinocytes. The extract improved cell viability comparing to control after UVB irradiation. In the determination test of pro inflammatory cytokines the extract decreased expression of interleukin 1 a and 6, which play an important role in inflammation and skin erythema caused by UV. We also studied property of varying cosmetic formulations on the percutaneous absorption of the extract. After 24 hour in vitro penetration study, the content of the extract was more highly detected in skin residue part. This result showed the extract had relatively high compatibility of skin in our emulsion system. On human skin, after appling the product containing the extract we obtained a good result of antiwrinkle effect by skin visiometer. In conclusion, the Acer palmatum extract is a photoprotective and very effective in stressed and aged skin care. And we can predict the extract mainly affects on the skin cell and tissue in our emulsion system.

• 대한산업공학회지
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• 제39권3호
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• pp.149-155
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• 2013

Electric discharging machining (EDM) is commonly adopted to machine the precise and tiny part when it is difficult to meet the productivity and the tolerance by the conventional cutting method. The die-sinking EDM method works well to machine the micro-parts and the perpendicular wall of die and mould, whereas EDM drilling, called super drill, is excellent to machine the deep and narrow hole regardless the material hardness and the hole location. However, the electrode wear is rapid compared to the conventional cutting tool and makes it difficult to control the electrode feeding and to machine precisely. This paper presents an efficient method to estimate the electrode wear using hole pass-through experiment while the stochastic method is used to compensate for the estimation model. To validate the proposed method, the commercial EDM drill machine is used. The experiment result shows that the electrode wear amount can be predicted very precisely.

• 대한기계학회논문집
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• 제17권5호
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• pp.1106-1114
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• 1993

본 연구에서는우수한 섬유강화 고분자복합판의 제조 및 개량을 섬유구조의 분리. 배향의 관점에서 연구한다. 유리섬유매트는 유리섬유를 50mm의 길이로 균일하 게 절단하여 공기중에서 분산시켜 6~7mm두께로 만들고,이 유리섬유매트를 바늘의 종류와 스트레칭 횟수에 따라 니들펀칭하여 유리섬유의 매트구조를 변화시킨다. 유리 섬유의 매트구조 별로 모재와 적층시킨 다음 열압축프레스를 사용하여 1차로 시이트를 제작하고, 이 제작된 시이트를 가열로로 가열하여 2차 고온압축 프레스성형한다. 이 때 섬유와 모재의 분리 및 배향의 상관관계를 나타내는 상관계수를 구하고, 이 계수에 미치는 매트 구조의 영향에 대한 실험결과를 보고한다.

• 한국응용과학기술학회지
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• 제19권4호
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• pp.302-310
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• 2002

Demand for organic analysis increase as industries are growing and many products are spreaded in the daily life. One of many products is oil spill dispersant. It was used for oil accident in the ocean. When oil spill dispersant spread at the ocean, the petroleum in the ocean is dispersed. The oil spill dispersant is made of non ionic surfactant and petroleum oil. The non ionic surfactant disperse petroleum from oil accident. The other part is petroleum oil which has aromatic hydrocarbon. Because the aromatic hydrocarbon is cancerogenic material, it directly injure animals in the ocean. This cause the second pollution in the human body. Many oil accidents still are controlled by oil spill dispersant. Therefore quality control of the oil spill dispersant become important and this also demand for the exact quantitative analysis of aromatic hydrocarbon. Hereupon the first we develop separate petroleum oil from surfactant. The second standardize analytical method of aromatic hydrocarbon in the separated petroleum oil.

• 한국재난정보학회 논문집
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• 제15권4호
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• pp.524-530
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• 2019

연구목적: 본 논문에서는 3차원 해석프로그램을 활용하여 인터페이스 요소를 구성하고, 일반적인 부재의 특성치와 강도가 보강된 부재의 특성치 등의 실제 표현할 수 있는 물성조건을 적용하여 연결체의 복합거동 안정성을 평가하고자 하였다. 연구방법: 해석 모델은 비선형적인 재료 거동을 포함한 솔리드 요소(Solid Element)를 사용하여 빔 구조 및 원형 플랜지, 볼팅 시스템 등의 부재를 설계도면과 동일한 치수로 모델링을 완성하였고 각 부재는 하나의 복합거동연결체로 조립되는 과정에서 다른 요소유형(Element Type) 접촉면의 통일성과 매쉬(Mesh) 생성을 보다 효율적으로 제어하여 분할작업(Partition)을 수행하였으며 부재들에 활용된 강재는 Gr. 50 탄소강 재질로 모델링 하였다. 연구결과: 부재별 접촉 인접부위, 하중재하부위, 고정단 부위, 취약예상부위 등으로 하여 하중단계별 변위 및 변형, 응력상태 등을 나타내고, 유한요소 해석 후 복합거동연결체의 각 하중단계에서의 변위, 변형, 응력 등의 분포도로 영향을 검증하고 설계의 타당성을 확인하였다. 결론: 따라서 이 결과를 토대로 하여 마이크로 파일의 설계 지지력이 결정되면 복합거동 연결체의 취약 지점의 파악과 보강의 정도를 파악할 수 있을 것으로 판단된다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2008년도 추계 학술발표회 제20권2호
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• pp.37-40
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• 2008

최근 급속한 속도로 변화하는 현대 사회에서의 건설 현장에서는 공기 단축 및 자재의 절감을 통한 공사비 절감이 절실히 요구되고 있는 실정이다. 현재 현장에서의 거푸집 공사기간이 전체 공사기간의 1/4정도 차지하고 있으며, 공사비는 전체 공사비의 $15{\sim}20%$를 차지하고 있다. 이에 공기단축, 거푸집 자재의 절감 및 거푸집 폐자재의 처리에 대한 어려움을 줄일 수 있는 중공PC 반건식 기둥의 사용성 및 구조적 성능을 평가하고자 한다. 중공PC기둥은 전단보강근이 배근된 상태로 피복두께 만큼 공장에서 제작되어 지므로 품질관리 및 부재의 정밀도 등 여러 이점이 있지만, 코아 부분은 현장에서 후 타설 하여야 하므로 중공PC와 코아 콘크리트 간의 부착성능이 기둥의 압축거동에 미치는 영향에 대한 검증이 필요하다. 따라서 본 연구에서는 중공PC와 코아 콘크리트 간의 부착성능 및 압축거동성능을 평가하고자 기존 철근콘크리트 기둥 1개와 코아 콘크리트의 압축강도가 다른 중공PC 기둥2개를 제작하여, 철근 콘크리트 기둥과 중공PC기둥의 압축거동성능에 대하여 비교 분석 하고자 한다.