• 한국세라믹학회지
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• 제28권11호
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• pp.935-941
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• 1991

Effects of calcination process and ZrO2 addition on the electrical properties of [(Ba0.82Sr0.08Ca0.1)O]m(Ti1-$\chi$Zr$\chi$)O2 ceramics have been investigated. With the variation of A/B-site ratio m of the dielectric formulations, sintering behavior and the resistivity after sintering in a reducing atmosphere have been affected by the calcination process. When the dielectric formulations of m=1.01 were sintered in a reducing atmosphere, the room-temperature resitivity of 109 {{{{ OMEGA }}.cm was obtained for samples processed with two-step calcination, which was much lower than 1012 {{{{ OMEGA }}.cm of samples calcined once. It was confirmed that high resistivity of Ca-doped BaTiO3 ceramics, after sintering in a reducing atmosphere, is maintained by acceptor-like behavior of CaTi" which is formed by Ca substitution to Ti-site. It was also found out that the critical amount of B-site Ca substitution for reduction inhibition of BaTiO3 is around 0.005 mol. With the increasing amount of ZrO2 addition to dielectric formulations, Curie peak was depressed and Curie temperature was lowered due to the enhanced diffuse phase transition.tion.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제12권1호
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• pp.72-81
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• 1990

Because failure of microvascular flap grafting has sometimes been attributed to vascular obstruction in the anastomotic site, this study investigated the healing process after microvascular anastomoses. The healing process of anastomotic sites were observed by the use of the light and the scanning electron microscope after microvascular anastomoses of the right common carotid artery in rats. The experimental animals were sacrificed on the 4th day, 1st, 2nd, 4th and 6th week. Throughout the whole experimental period, arterial patency rate was 78% (11/14). At the early stage, it was possible to recognize histologically disappearance of endothelial cell and rupture of part of the media. Subintimal hyperplasia and the growth of media appeared around the suture line at the 2nd week. Endothelial cell regeneration occurred and the depth of vessel wall was normalized at the 4th week. By the scanning electron microscope, at the early stage, the anastomotic site was covered with many platelets, red blood cells, fibrins and macrophages. At the 4th week, the insertion site of the thread was completely covered with normal endothelial cells which were parallel to longitudinal axis of vessels and complete reendothelialization over the anastomotic site seemed to take about 6th week.

• 대한가정학회지
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• 제44권12호
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• pp.189-201
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• 2006

The purpose of this study was to explore consumers' experiences in one used market site. For this purpose, in-depth interviews were conducted for the 8 consumers who were members of the used market site. In the study methodology, the grounded theory designed by Strauss and Corbin was utilized. From the analysis results, 23 subcategories and 11 categories were created. In the axial coding, the following paradigm model was proposed: 1) the casual conditions were "the pond of information" and "underground market," 2) the contextual conditions were "inconsistent behavior" and "error of communication", 3) the central phenomenon was "non-ethic behavior of seller/buyer, 4) the intervening conditions were "induction of intimacy", "use of patronage", and "creation of network", 5) the action/interaction strategy was "being shrewd", and 6) the consequence was "adaptation/non-adaptation". In selective coding, the core category was "to adapt of non-ethic behaviors through being shrewd." Based on the core category, the following four types of process of adaptation of the used market site were found: "A selfish addict," "An advanced utilitarian", "A hard philosopher," and "A cynical dropout".

• 한국주거학회논문집
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• 제17권6호
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• pp.149-157
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• 2006

In the planning process, there are five directions to planning residential sites. Firstly, the site must be planned to allow continuity with the city space, or created to conform to the city structure. Secondly, plans for community space and programs as well as convenience facilities must coexist in the road space. Thirdly, in terms of view, the site must be planned in territories to secure identity of the site. Fourthly, in terms of the environment, the site should utilize the natural environment. Lastly, in terms of infrastructure, the site should include a pedestrian-centered road system as well as establishing city infrastructure facilities for a combined planning in the municipal dimension. So far we have looked at planning methods for an apartment site that can be integrated into the existing city. The study into five elements to planning a large-scale apartment site, context, community, landscape, environment and infrastructure, and their relationship among each other must continue on.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2021년도 봄 학술논문 발표대회
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• pp.36-37
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• 2021

OSC(Off-Site Construction) is regarded as a faster and more economical method in the construction industry, and the attention towards the OSC is growing. In the modular construction process, which is one type of OSC, accurate identification of a module is essential. Because the installation position and the MEP(Mechanical, Electrical, and Plumbing) composition are distinct between modules, a defect in the finishing or junction area is likely to happen during the construction process. This study suggested the modular construction process by applying a beacon receiver using BLE(Bluetooth Low Energy) technology on each module. Construction quality management would be improved using the location and assembly data, particularly for a different module in modular construction.

• 한국산림과학회지
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• 제21권1호
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• pp.39-45
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• 1974

지위지수추정시 발생되는 오차를 감소시키기 위하여 수고생장과정에 적합한 실험식과 기타 정보를 얻고자 이 연구를 착수한 것이다. 11개 실험식으로 물오리나무, 일본잎갈나무, 잎갈나무, 잣나무, 젓나무, 리기다소나무, 상수리나무와 갈참나무의 수고생장 추정식을 계산하였다. 계산결과에 의하면 수종간에는 적합실험식의 종류가 서로 다르며 지위지수는 임령에 따라 항상 일정한 것이 아니고 변동하는 경우가 있으므로 지위지수추정시 수간석해 또는 다변형지위지수 곡선을 이용함이 합리적인 것으로 생각된다.

• 국제학술발표논문집
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• The 3th International Conference on Construction Engineering and Project Management
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• pp.738-746
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• 2009

The purpose of this study is to develop the web-based system for work performance analysis(WPAS). The need of work performance analysis system has already been suggested in many previous researches on the computerization of the performance measurement in the construction site by using the indicators such as time, cost and quality. However, they had focused on measuring or analyzing the result when the project would be over. The WPAS suggests three indicators - work reliability, work effectiveness and work efficiency - to manage the performance of the construction site. It can help the manager more easily recognize the status of on-going work in the construction site by measuring and analyzing the work reliability rate, the work effectiveness and work efficiency every day. This research includes the procedures for WPAS measurement process, database structure of WPAS which was analyzed by the IDEF0 and the data flow diagram. Finally, this research introduces the result of WAPS's case studies and validation in the Korean construction site.

• 국제학술발표논문집
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• The 3th International Conference on Construction Engineering and Project Management
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• pp.579-586
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• 2009

4D simulation integrates the 3 dimensional model of a building with the construction schedule, and it leads to the possibility of virtually checking the construction process and the building itself in advance. However, the existing problem of 4D simulation is the difference between the demands of architects, engineers, and construction site workers in 4D simulation. This study suggests the possible way to enhance the availability of 4D simulation, considering more the practical demands from the construction site. In order to conduct this study, we build a 3D BIM model of a business-residential complex and link the model with the pre-defined construction schedule in order to make a 4D simulation. This study concludes with the optimized 4D simulation methodology based on BIM model considering the demands in perspective of the construction site. It would contribute to the harmonic collaboration among architects, engineers, and labors in the construction site when using 4D simulation based on BIM model.

• 국제학술발표논문집
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• The 6th International Conference on Construction Engineering and Project Management
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• pp.716-717
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• 2015

A construction temporary work is main process and importance trade section. A technology system of construction temporary has very low availability of field works and needs improvements in Korea as construction site has a quick response about new requirements. This study reviews literature researches and can verify that changes to a comprehensive technology system for construction site. In addition, it suggests a breakdown structure of new standards for temporary construction technology based on views of construction site managers. Meanwhile, temporary construction technology in Korea has changed with a specification of construction temporary work which had been revised in 2014. However, the revision is merely dividing the design and building off of construction temporary technology. It is lacking in many ways to change this in a new standard system for temporary construction technology. Henceforth, it needs to develop a standard system for temporary construction technology and a professional system that is appropriate for different purposes by detail trade sections.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2022년도 가을 학술논문 발표대회
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• pp.41-42
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• 2022

This study analyzed the process related to the linkage between on-site work targeting the middle size Precast Concrete(PC) public apartment building with beam-column system and prepared on-site works flow relationship diagram in which the wet process consists of core Critical Path(CP) to prepare a network diagram of the Precedence Diagram Method(PDM). Through this study, it is expected that it will be possible to maximize the project management capability by suggesting a method to minimize risk factors and the optimized process management of the beam-column system PC public apartment building.