• Structural Engineering and Mechanics
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• 제9권4호
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• pp.365-374
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• 2000

The structural behavior of connections between concrete-filled rectangular tubular column (CFRT column) and steel beam has been studied in this paper through sub-assemblage loading tests. It is found that the sub-assemblages exhibit ductile restoring force characteristics under seismic loading. A formula for the prediction of the yield strength of each member in the connection is proposed by using the yield line theory under the assumption of a simple stress transfer mechanism. It is shown that the proposed formula can produce a reasonable prediction while providing a basis for further investigation.

• 항공우주시스템공학회지
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• 제1권3호
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• pp.21-25
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• 2007

This is a study on the establishment of airworthiness certification system fitted for korean military aircraft acquisition and export. Based on the investigation of US civil & military airworthiness system and analysis of the real state of domestic military aircraft acquisition, this paper offers some ideas that can be helpful to establish laws and organizations to certify airworthiness. Particularly this paper suggests that the best way to build airworthiness certification laws/guidelines and technical criteria, the optimal organizational structure which is decentralized by dividing administrative certification authority and technical research center.

• 펄프종이기술
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• 제46권2호
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• pp.16-21
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• 2014

Characteristics of coating color penetration into paper were elucidated using various types of pulps and pigments. A commercial paper, KP and TMP handsheets were used for base paper. Clay and GCC were used as coating pigment. Laboratory rod draw down coater was used for coating application. Coating color penetration was evaluated by measuring the roughness of surface and back side of a coating layer. The results of coating roughness showed that clay was much better than GCC as a coating pigment. In case of pulp type, KP base paper was more effective than TMP base paper to reduce coating penetration.

• 한국펄프종이공학회:학술대회논문집
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• 한국펄프종이공학회 2003년도 추계학술발표논문집
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• pp.139-147
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• 2003

Coater runnability of the paper coating and final product properties can be affected by the immobilization of coating color and the dewatering into the base paper. During the dewatering, the rheological properties and solids content of a coating are dramatically changed. For the purpose of obtaining better coater runnability and high quality of coater paper many papermakers are trying to improve the water retention of paper coatings by using some additives such as thickener and co-binder. In this study, we tried to investigate the rheological properties and the immobilization point of coatings with immobilization cell during the dewatering of coatings.

• 한국펄프종이공학회:학술대회논문집
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• 한국펄프종이공학회 2003년도 추계학술발표논문집
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• pp.9-16
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• 2003

Interaction between wood-destroying basidiomycetes and blue stain fungi were studied during conjoint cultivation on 2% malt extract agar. The ability of basidial cultures to decolourise dark pigments of ophiostomatoid fungi was the main characteristics estimated during this investigation. Antrodiella hoehnelii(S28/91), Bjerkandera fumosa(137), Gleophyllum odoratum(124), Trametes versicolor (B18/91) cultures were found to be the most active in decreasing dark colour of blue stain fungi colonies. The cultures were recommended for further development as agents of biopulping and control of blue stain fungi in wood chips.

• 펄프종이기술
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• 제33권2호
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• pp.17-23
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• 2001

AKD sizing behavior of handsheets, which were prepared from the different pulps with various AKD fixing agents, was studied in this investigation. AKD sizing performance could be improved by removal of fines in the stock, minimizing damage of fiber, using a suitable fixing agent and heat treatment. Fillers with low surface energy, like calcium carbonate and talc, showed quite positive effect in AKD sizing. When PAM was added to the DIP stock as fixing agent, it showed lower sizing degree than polyamine did. But in case of NBKP system, PAM was more effective than polymine.

• 펄프종이기술
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• 제48권1호
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• pp.5-18
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• 2016

Electron microscopy is an important investigation and analytical method for the morphological characterization of various cellulosic materials, such as micro-crystalline cellulose (MCC), microfibrillated cellulose (MFC), nanofibrillated cellulose (NFC), and cellulose nanocrystals (CNC). However, more accurate morphological analysis requires high-quality micrographs acquired from the proper use of an electron microscope and associated sample preparation methods. Understanding the interaction of electron and matter as well as the importance of sample preparation methods, including drying and staining methods, enables the production of high quality images with adequate information on the nanocellulosic materials. This paper provides a brief overview of the micro and nano structural analysis of cellulose, as investigated using transmission and scanning electron microscopy.

• 한국진공학회지
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• 제6권S1호
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• pp.133-136
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• 1997

In this paper multi-arc plasma plating film equipment Bulat-6 and its technical characteristics were analyzed in detail. This machine is the first of its kind in China. Influential factors and reducing methods on microdroplets of titanium were investigated. By method of electromagnetic field control and ion beam enhanced deposition excellent titanium nitride film could be obtained. Bicrohardness and adhesion were 250Mpa and 6.5Kg respectively.

• 대한공업교육학회지
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• 제30권1호
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• pp.1-18
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• 2005

The purpose of this study was to development a model of problem solving instruction for improving practical skill-competence in technical high school. For the study, various literature researches were reviewed intensively about problem solving process, laboratory instruction's approaches and learning principals. The problem solving instruction process was composed with identifying problems, generating alternative solutions, investigation and research, choosing a solution, acting on a plan, modeling of problem solving, testing and evaluating, redesigning and improving. The skills schema combines a four domain of skilled activity, that is, cognitive skills, psychomotor skills, reactive skills and interactive skills. The problem solving instruction was composed with five major learning systems-emotional, social, cognitive, physical, and reflective-that can be used extensively as generic lesson plashing. The teacher serves as a coach or guide for student learning. As a facilitator, the teacher challenges, questions, and stimulates the students in their thinking, problem solving and self-directed study. In this process, students represent problem with think aloud, assume responsibility for their learning and move from teacher-centered to student-centered education.

• Journal of Information Processing Systems
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• 제5권4호
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• pp.197-206
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• 2009

We introduce a novel high-level security metrics objective taxonomization model for software- intensive systems. The model systematizes and organizes security metrics development activities. It focuses on the security level and security performance of technical systems while taking into account the alignment of metrics objectives with different business and other management goals. The model emphasizes the roles of security-enforcing mechanisms, the overall security quality of the system under investigation, and secure system lifecycle, project and business management. Security correctness, effectiveness and efficiency are seen as the fundamental measurement objectives, determining the directions for more detailed security metrics development. Integration of the proposed model with riskdriven security metrics development approaches is also discussed.