• The Journal of Advanced Prosthodontics
• /
• 제11권4호
• /
• pp.215-222
• /
• 2019

PURPOSE. To evaluate the polishing effect on roughness and color change of pressed and layering ceramics after immersion in coffee solution. MATERIALS AND METHODS. 88 ceramic discs ($1.0mm{\times}10.0mm$) were manufactured - 44 nano-fluorapatite layering ceramics (IPS e.max Ceram. Group C) and 44 pressed lithium disilicate ceramic discs (IPS e. max Press - Group P). Each group was divided into 4 subgroups according to surface treatments: (G) Glaze, (S) Shofu polishing system (Shofu Inc.), (E) Edenta AG polishing System, (KG) $30-{\mu}m$ diamond granulation tip. Surface roughness (Ra) and color change (${\Delta}E$) measurings after the surface treatments were performed, before and 12 days after the immersion in coffee solution. A samples' qualitative analysis was conducted with a scanning electron microscopy (SEM). Data were statistically-treated with one-way-ANOVA and Duncan's tests, apart from paired t-test and Pearson's correlation test (${\alpha}=5%$). RESULTS. The decrescent order, both for surface roughness (Ra) and ${\Delta}E$ for both ceramics were: KG > E > S > G (P<.05). With exception for PG and CG subgroups, which did not present statistical difference between them, all other pressed ceramics subgroups presented smaller Ra values and greater ${\Delta}E$ values than the layering ceramics subgroups (P<.05). CONCLUSION. Although mechanical polishing systems presented intermediate Ra values, their colors were considered clinically acceptable. There is a strong correlation between the surface roughness and the color change of tested ceramics.

• Restorative Dentistry and Endodontics
• /
• 제13권1호
• /
• pp.139-150
• /
• 1988

The purpose of this study was to evaluate the marginal adaptation of Class V resin restorations by the filling techniques. The cavities were filled with Heliosit$^{(R)}$ light curing composite resin system in accordance with the following three filling techniques - bulk-pack placement technique, apical to occlusal layering placement technique, and buccolingual layering placement technique. And the interface between the restoration and the tooth structure was observed with scanning electron microscope. The following results were obtained. 1. Marginal adaptation of enamel showed excellent irrespective of the filling techniques. 2. Marginal leakage of dentin was observed irrespective of the filling techniques. 3. No difference of marginal adaptation according to the filling techniques was observed in light curing composite resin.

• 복식문화연구
• /
• 제20권2호
• /
• pp.222-237
• /
• 2012

Air-containing fashion, which can offer diverse functions through the inflow and outflow of air, is highly relevant in today's mobile society, where people are experiencing a wider range of environments. This study attempts to suggest the possibility of air-containing multi-functional fashion that could continuously be utilized by developing a design for an air-containing jacket using modular systems. In this research, the modular systems in architecture and furniture design were referenced through a review of the literature for the purpose of establishing modular systems in fashion. Functions relevant to the mobility of today's society are derived from the results of advanced research and applied to the design of modules of the jacket. The modules are integrated through the modular systems. The folding and unfolding structure in architecture and furniture is applied as a folding system in fashion, the vertical accumulation structure as a layering system, and the horizontal integration structure as a combining system, and in addition, the containing system has emerged in fashion. Each module is designed to fulfill certain functions, such as cushioning, heat insulation, and portability. The folding system is utilized in designing the cushion module to support the neck and back of a wearer by making its hood and hem fold in the back. The application of a layering system was suggested by making the vest, combined with the neck cushion and back cushion via the combining system, layered with its insulation module. By applying the combining system, the hood that includes the neck cushion, the skirt that includes the back cushion, the body that includes the insulation module, and the sleeves can be connected and separated by a zipper. The applicability of this concept was proven by applying a developed design to an actual item.

• 터널과지하공간
• /
• 제16권1호
• /
• pp.85-94
• /
• 2006

본 연구에서는 장대 터널 화재시 발생되는 역기류를 제압하는 최적의 임계속도를 결정하기 위하여 제연설비를 가동시키는데 소요되는 시간, 피난자들의 대피시간 등에 대한 연구 자료들을 취합, 분석하였고, 이를 토대로 화재 시나리오를 설정하여 축소 모형실험을 실시하였다. 비상 환기시스템 가동시점을 분석한 결과, 화재 발생후 약 240초(약 4분)후 비상 환기시스템이 가동하게 되며, 제연팬 가동 후 4분 이내에 역기류를 제어할 수 있는 임계속도를 확보하는 것이 실제 터널에 적합한 시간 시나리오였다. 화재지점 주변의 역기류 분포를 분석하기위해 Froude 상사이론에 기초한 아크릴 재질의 축소비 1/50의 모형(직경 : 0.2m, 연장 : 20 m)을 제작하였고, Tetzner 식의 보정계수$(\beta)$를 변화시키며 화재지점 주변의 CO농도를 측정한 결과, 보정계수가 0.5인 경우에 피난허용시간 기준에 적합한 제연효과를 나타내었다.

• 디지털융복합연구
• /
• 제11권9호
• /
• pp.29-43
• /
• 2013

출연연 제도변화에 대한 지배적인 관점은 환경 정책변화라는 외부적인 환경의 요구사항에 기능적으로 대응하기 위해 변화한다는 기능론적 입장이다. 하지만 출연연 제도는 내부적 요인으로 인해 변화가 발생하기도 한다. 따라서 출연연 제도변화를 분석에 있어서 외부적 요인과 내부적 요인이 상호작용해서 변화가 발생한다는 동태적인 대안적 모형이 필요하다. 본 논문에서는 출연연 예산제도가 연구과제중심제도(PBS 모델)에서 묶음예산 모델로 변화하는 과정을 살펴보았는데, 변화과정이 동태적 제도변화 양식 중에 층화(layering)에 해당함을 확인하였다. 즉 외부적 요인과 내부적 요인이 상호작용해서 PBS 모델을 수정하기 위해 정부출연금 확대라는 제도개선의 층을 지속적으로 누적시켰다. 결국 안정적 연구환경 조성 및 연구전념을 위해 지속적으로 누적된 정부출연금 확대라는 제도개선의 층은 정치적 계기를 맞아 단계적으로 빠르게 성장함으로서 묶음예산 모델로 변화되는 동태적인 과정을 확인하였다.

• 건축역사연구
• /
• 제20권5호
• /
• pp.47-61
• /
• 2011

This study examined the background and change of building Yeongam eupseong and characteristics and construction method of its spatial structure. The results of this study can be summarized as follows. First, Yeongam eupseong was built for the same purpose of national border defense against the invasion of Japanese army as other Eupseongs were built and it was found first in the literature in the era of King Munjong of Joseon Dynasty with the scale of three gates and 4,369 cheok of castle wall. Such a scale was continued and in particular, according to flat structure, road network and gate position shown in the map, the form and road system of Yeongam eupseong before the 19th century were mostly identical with the current ones. Second, castle wall was built over foundation by using talcum after leveling the foundation soil and castle wall can be divided into outer wall, filling part and inner wall from the section. Outer wall was constructed by inserting and layering pebbles with big irregular stone, filling part was made with talcum and riprap and inner wall with soil in several layers by keeping gradient. This building method showed common features in inserting and layering pebbles for outer wall, use of protruded base and section form compared to Jeollado Eupseong.

• 한국의류학회지
• /
• 제46권5호
• /
• pp.910-926
• /
• 2022

Suitability for the human body, freedom to move and thermal insulation are important design considerations in military clothing. This study investigates the performance and wearer-satisfaction of the functional inner winter uniform currently used in Korea; it is hoped that our data can inform the development of a future version. Interviews were conducted, in which the participants suggested various improvements. The uniforms were mainly worn for guard duty or as daily attire in cold weather. The participants chose how many layers to wear according to the current situation, rather than sticking to the layering recommended in the manual. Layering choices did not significantly affect combat efficiency but were found to affect wearers' comfort. Wearers' satisfaction was found to depend on the convenience of the clothing, whether it was in the appropriate size, freedom to move and thermal insulation. Also, this study suggests a problem with the current size system, as the analysis of size distribution, across all sizes, the range of current production is insufficient to cover the demand.

• 인터넷정보학회논문지
• /
• 제9권5호
• /
• pp.35-46
• /
• 2008

서비스 기반 아키텍처의 서비스들 사이에서 연결 테스트를 하기 위하여 서비스 기반 아키텍처의 연결 특성을 분석하고, 분석을 통해서 서비스 기반 아키텍처 특성을 표현한 서비스 메시지 흐름도를 정의한다. 이 정의를 토대로 본 논문은 서비스 연결 테스트하기 위한 방안을 제안하고 실제 서비스 기반 아키텍처를 사용하는 회사에 이를 적용한다 최근 많은 기업들에서 기존의 시스템을 서비스 기반 아키텍처로 재구축하려는 움직임이 활발하다. 그러나 이러한 프로젝트들이 현실적으로 실제 시스템으로 사용되기 어려운 점은 그에 대한 연결테스트의 부재이기 때문이다. 또한 SOA에서의 통합과 연결에 차이에 대해 느끼지 못한다는 문제와 그에 따른 서비스의 계층 간의 연결에 대한 테스트의 필요성을 느끼지 못한다는 문제이다. 따라서 본 논문에서는 서비스 기반 아키텍처가 준수해야 하는 계층구조를 기반으로 서비스 연결 테스트 방안을 제안하고, 차별화 되는 두 가지 사례에 적용한다.

• 한국의류산업학회지
• /
• 제8권6호
• /
• pp.709-712
• /
• 2006

The aim of this study is to find out comfortable combinations of layered system for outdoor activities through water vapor permeability. Layering fabrics is an effective way of controlling water transport properties in fabric systems for outdoor activities and analysis of these systems may be useful for designing comfortable clothing. Seven fabrics were chosen for the experiments: two fabrics for base layer, two for the middle layer and three for the shell layer. A total of 12 different layered systems, which are all possible combinations were established using selected fabrics. The water vapor permeability was measured using JIS L1099 under isothermal and non-isothermal conditions. It was found that layered system was working together as a whole having influence on each layer, though every layer offers varying degree of water vapor permeability. Furthermore, it was also found that an optimal combination of the three layered system does exist although the combination may differ according to the ways. The shell layer is the greatest effect of water vapor permeability under isothermal and non-isothermal conditions within layered system.

• Journal of the Korean Wood Science and Technology
• /
• 제34권3호
• /
• pp.8-14
• /
• 2006

목재의 탄화기구를 이해하기 위하여 굴참나무재를 사용하여 $250{\sim}740^{\circ}C$의 온도조건에서 탄화하였다. 탄화온도가 높아질수록 시험체의 부피는 수축하였고, 방사 방향으로 할렬이 발생하였다. 탄화온도가 증가함에 따라 목탄의 중량감소율은 증가되었으며, 특히 탄화온도 $300{\sim}340^{\circ}C$에서 급격히 증가하는 경향이 나타났다. 목재의 도관은 탄화 시 방사방향보다 접선방향으로 매우 크게 수축하였다. 탄화온도 $250{\sim}300^{\circ}C$의 경우, 목섬유나 도관 주위의 유세포들이 탄화되지 않은 세포벽 형태를 보여주었다. 그러나 탄화온도 $340^{\circ}C$이상에서는 세포벽층이 매끄러운 비결정형인 목탄의 형태가 관찰되기 시작하였다. 탄화온도 $300^{\circ}C$까지는 목재 셀룰로오스의 결정성이 남아있었으나 $340^{\circ}C$ 이상에서는 비결정성으로 변화되고 있는 것이 관찰되었다.