• 대한토목학회논문집
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• 제31권5C호
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• pp.171-185
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• 2011

레디믹스트(Ready-mixed) 숏크리트는 전문공장에서 원재료를 건조배합 형태로 생산하여 시공현장으로 운반 및 타설되는 재료로서, 확실한 골재 품질관리가 가능하며 규격화된 재료 사용으로 시공 품질 개선이 가능하다. 특히, 현장 배치플랜트의 축소 혹은 생략이 가능하기 때문에, 설치비용 절감 및 부지확보로 인한 민원과 환경문제를 해결할 수 있는 추가적인 장점이 있다. 본 연구에서는 숏크리트 성능 향상을 위한 방법으로 혼화재 및 급결제에만 국한되어 있던 기존 연구방향을 벗어나, 골재 자체의 품질 개선을 통해 숏크리트 성능을 향상시키고자 하였다. 기초 연구에서는 국내 숏크리트 시공실태 및 공급골재의 품질파악을 실시하였고, 현장실험을 통해 레디믹스트 숏크리트의 굵은 골재 최대치수를 8mm로 결정하였다. 또한, Pilot Plant Test를 실시하여 공장생산 공정의 재료분리 현상을 최소화 하고자 하였고, 현장실험을 통해 강섬유와 동일 수준의 휨인성을 발휘할 수 있는 합성섬유의 최적 혼입량과 고로슬래그 미분말의 최적 치환율을 도출하였다.

• 생약학회지
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• 제51권3호
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• pp.222-229
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• 2020

Recently, consume for functional cosmetics containing natural products has been greatly increased. In order to develop it as a natural cosmetic material, we selected Ixeridium dentatum (Thunb.) Tzvelev, Plantago asiatica L. and Rumex crispus L. that have antioxidant and anti-inflammatory effects. In this study, simultaneous quantitative analysis of the isolated compounds and natural product complexes (Mix.) were validated using high performance liquid chromatography (HPLC). The isolated six compounds were shown in a large linearity with a correlation coefficient (R²) of 0.99. The limit of detection (LOD) of chlorogenic acid, plantamajoside, acteoside, emodin chrysophanol and physcion were 0.36 ㎍/mL, 0.36 ㎍/mL, 0.37 ㎍/mL, 0.30 ㎍/mL, 0.22 ㎍/mL and 0.12 ㎍/mL, respectively. The limit of quantification (LOQ) of chlorogenic acid, plantamajoside, acteoside, emodin chrysophanol and physcion were 1.10 ㎍/mL, 1.08 ㎍/mL, 1.12 ㎍/mL, 0.99 ㎍/mL, 0.66 ㎍/mL and 0.35 ㎍/mL, respectively. Content analysis showed chlorogenic acid (0.19 ± 0.02%), plantamajoside (0.48 ± 0.01%), acteoside (0.65 ± 0.01%), emodin (1.15 ± 0.11%), chrysophanol (0.73 ± 0.01%) and physcion (0.69 ± 0.09%). Therefore, the results of this study may provide for basic data of standardization research natural cosmetic material development on the I. dentatum, P. asiatica and R. cripus.

• Restorative Dentistry and Endodontics
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• 제40권3호
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• pp.229-235
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• 2015

Objectives: To determine and compare the fracture resistance of endodontically treated maxillary central incisors restored with different posts and cores. Materials and Methods: Forty-eight upper central incisors were randomly divided into four groups: cast post and core (group 1), fiber-reinforced composite (FRC) post and composite core (group 2), composite post and core (group 3), and controls (group 4). Mesio-distal and bucco-lingual dimensions at 7 and 14 mm from the apex were compared to ensure standardization among the groups. Twelve teeth were prepared for crown restoration (group 4). Teeth in other groups were endodontically treated, decoronated at 14 mm from the apex, and prepared for posts and cores. Resin-based materials were used for cementation in groups 1 and 2. In group 3, composite was used directly to fill the post space and for core build-up. All samples were restored by standard metal crowns using glass ionomer cement, mounted at $135^{\circ}$ vertical angle, subjected to thermo-mechanical aging, and then fractured using a universal testing machine. Kruskal-Wallis and Mann-Whitney U tests were used to analyze the data. Results: Fracture resistance of the groups was as follows: Control (group 4) > cast post and core (group 1) > fiber post and composite core (group 2) > composite post and core (group 3). All samples in groups 2 and 3 fractured in restorable patterns, whereas most (58%) in group 1 were non-restorable. Conclusions: Within the limitations of this study, FRC posts showed acceptable fracture resistance with favorable fracture patterns for reconstruction of upper central incisors.

• 펄프종이기술
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• 제41권3호
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• pp.66-70
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• 2009

Paper cultural heritages usually experienced the chemical and the physical deterioration because of various factors including preservation environment and the property of their materials. General restoration technology for paper cultural heritages is the lining. The application of the lining paper and the lining technology has varied depending on researcher's experiences. Therefore, each lining material and technology must be evaluated to develop a standard guide for preservation and restoration of paper cultural heritages. To date, various analysis techniques using lining paper, in terms of their materials, have been applied to analyses of causes and condition of damages, but it is difficult to develop a standard restoration treatment method of paper cultural heritages because it varies by their material. The Hanf, is made frrr the mulberry, is generally used for the lining in Korea.edt is required that the cr, in terms properties and general properties of Hanf, is used for lining papers, are evaluated to develop a standard guide for their restoration.ed this study, the general properties of several lining papers(Hanf), especially dimensave bility, were evaluated as part of the standardization of lining papers. The result have varied depending on the pulping chemical and the manufacturers. the basis weight, thickness and tensale strength of lining papers is bigger the paper treated by natural ash than the paper treated by sodium carbonate.ed case of formation, folding endurance, and dimensave bility, the paper treated by sodium carbonate showed better properties than those of the paper treated by natural ash.

• 한국항만경제학회지
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• 제25권3호
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• pp.1-20
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• 2009

본 연구에서는 파렛트 풀 서비스 사용자의 효익이라는 관점에서 파렛트 사용자를 대상으로 파렛트를 선택하는 주요 속성인 가격, 규격, 정합성, 재질 등에 대한 선호도에 대해 설문조사를 실시하였다. 설문조사는 수도권 창고업체를 대상으로 하였으며 컨조인트 분석기법을 통해 군집분석 및 초이스 시뮬레이션을 실시하였다. 그 결과 파렛트와 차량, 설비 및 제품과의 정합성이나 파렛트 재질을 규격보다 더 중요시하는 경향을 보였다. 이는 다양한 온도대의 상이한 물품을 보관하는 창고업체의 특성상 그 보관 목적에 맞는 다양한 제품군을 가진 파렛트를 선호함을 알 수 있었다. 따라서 파렛트 풀 서비스를 제공하는 업체의 입장에서는 이러한 세분화된 고객별로 적절한 마케팅 전략을 수립하여 향후 국내경쟁 및 해외경쟁에 대한 경쟁력 우위전략을 확보하여 경쟁력을 극대화시킬 수 있을 것이다. 이와 같이 국가물류표준화의 핵심이라고 할 수 있는 표준파렛트의 보급이 개별단위 물류의 표준화가 아닌 전체 물류시스템의 표준화랑 조화를 이루기 위해서는 다양한 물류활동 참여자에 대한 그 특성별 호환성이 전제되어야 할 것이다.

• International Journal of Internet, Broadcasting and Communication
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• 제14권3호
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• pp.171-181
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• 2022

Purpose: In this paper, we show our blending ratio of 10 types of Essential Oils that survives beneficial bacteria and kills harmful bacteria in the scalp, and we investigate the possibility of application of our blending ratio to the development of anti-dandruff products and the possibility of being used as a raw material for clinical beauty and customized cosmetics. Methods: The scalp microorganisms used in our study were M. furfur, S. epidermidis, E. coli, and P. nitroreducens. There are a total of 10 Essential Oils such as True Lavender, Lime, Roman chamomile, Rosemary camphor, Cedarwood, Geranium, Clove, Tea tree, Palmalosa, and Peppermint. The antibacterial test of the blended Essential Oil was carried out according to the test method of the standardized evaluation methodology of "Food and Food Additives Code". Since M. furfur is related to the growth of sebum in the scalp, in this study we used the fnLNB and the fnLNA with 20 ㎖ of whole fat cow milk added. Results: The blending ratio of EO, which inhibits dandruff-causing bacteria such as M. furfur, S. epidermidis, E. coli, and does not inhibit P. nitroreducens showing dominant growth in a healthy scalp, was B8(Clove 0.2%, Roman chamomile 0.5%, Tea tree 0.3%), B9(Geranium 0.1%, Palmarosa 0.1%, Roman chamomile 0.5%, Tea tree 0.3%), B10(Clove 0.1%, Geranium 0.1%, Palmarosa 0.1%, Roman chamomile 0.5%, Tea tree 0.2%). Conclusion: It is thought that the blending ratio of BEO obtained as a result of this study can provide a basis for use as an alternative to antibiotics in developing anti-dandruff drugs and emerge as a new alternative to solve scalp microbial imbalance. In order for EO to be used as a useful raw material for anti-dandruff preparation, researches on 1) Standardization (the effects of products differ according to the types, regions, climate, extraction methods, etc.), 2) Antimicrobial effects, 3) Safety, etc., must be established.

• Imaging Science in Dentistry
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• 제32권3호
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• pp.147-151
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• 2002

Purpose: To compare the standard deviation of gray levels on digital subtracted images obtained by different dental subtraction programs. Materials and Methods: Paired periapical films were taken at the lower premolar and molar areas of the phantoms involving human mandible. The bite registration group used Rinn XCP equipment and bite registration material, based on polyvinyl siloxane, for standardization. The no bite registration group used only Rinn XCP equipment. The periapical film images were digitized at 1200 dpi resolution and 256 gray levels by a flat bed scanner with transparency unit. Dental digital subtraction programs used for this study were Subtractor (Biomedisys Co., Korea) and Emago (Oral Diagnostic Systems, The Netherlands). To measure the similarities between the subtracted images, the standard deviations of the gray levels were obtained using a histogram of subtracted images, which were then analyzed statistically. Results: Subtracted images obtained by using the Emago program without manual selection of corresponding points showed the lowest standard deviation of gray levels (p<0.01). And the standard deviation of gray levels was lower in subtracted images in the group of a bite registration than in the group of no use of bite registration (p < 0.01). Conclusion: Digital radiographic subtraction without manual selection of reference points was found to be a convenient and superior method.

• 한국해양공학회지
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• 제33권6호
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• pp.495-503
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• 2019

Approximately 90,000 ships are registered in South Korea, and about 80,000 of these ships are used in domestic shipping. Among these, 84% are small ships, such as a fishing vessels that weigh less than 20 tons and are made mostly of an FRP (Fiber Reinforced Plastics). When this fact is taken into account, the greenhouse gas emissions that are released per ton of a composite vessel are sizeable. In this study, the laminated structures of an FRP fishing vessel, many of which currently are being built in Korea, were analyzed by ISO (International Organization for Standardization) and international design rules, and the structures of the hulls are lightweight with optimum glass fiber mass content as determined by the laminate weight minimization algorithm. As a result, it was confirmed that the laminations of the vessels in accordance with the Korean rule could have 6.4% to approximately 11% more design margin compared to the requirements of ISO and other international rules. And the case study of the application of the laminate weight minimization algorithm showed the possibility of reducing the weight of the hull bottom plating by as much as about 19.32% and by as much as about 18.06% in the overall structure.

• 한국안전학회지
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• 제32권1호
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• pp.108-114
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• 2017

According to an increase in demand for polyurethane soft foam for thermally insulated containers, the purpose of this study is based on redefining existing rigid polyurethane foam insulation KS standard which has been limited to building material-based authentication techniques. Since there are arising concerns of consumer rights and safety due to humidifier fungicides and urethane track incidents, there are elements to be further researched on rigid polyurethane foam insulation for refregerated containers. Thus, we reviewed the prior standards for rigid polyurethane foam insulation and verified the validity of certification testing method for the new standard with self-foamed polyurethane.

• 복식문화연구
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• 제8권6호
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• pp.887-898
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• 2000

Mourning & funeral ritual means a various kinds of ritual procedures which begins at the time of death, buried and created a graveyard, a manner of wearing funeral garment being mourning the death, finally go back to everyday life. Our mourning & funeral custom was burial at first time. After going through the era of the Three kingdoms, The unified Shilla and Korea dynasty, cremation method has been prevailed. However, based on Chu-tzu celebration in Chosun dynasty, the burial custom has been widely spread again. Nowadays, due to effective land utilization issue, excessive cost for burial and the change of thinking for cremation, the cremation is recognized as remedy of righteous funeral system. At this point, a shroud following existing burial custom burdens considerably for quality, price, size and design of it. Accordingly, it needs anew style of shroud corresponding to cremation system. As an alternative, the shroud is required simplification and standardization ; Firstly, in size, a shroud should be larger than plain clothes and differentiated in small, medium and large. Secondly, the material of a shroud would be white cotton, which can keep from pollution during burning time. Thirdly, it unifies the item. In case of man, 바지(把特, those are trousers), 저고리(赤古里, Korean-style jacket) and Durumagi(周衣, Korean topcoat). In case of woman, 치마(赤　, those are skirt), 저고리(赤古里, Koran-style jacket) and Durumagi(周衣, Korean topcoat).