• Journal of Mechanical Science and Technology
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• v.19 no.2
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• pp.567-577
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• 2005

Several methods for improving the interlaminar strength and fracture toughness of composite materials are developed. Through-the-thickness stitching is considered one of the most common ways to prevent delamination. Stitching significantly increases the Mode I fracture toughness and moderately improves the Mode II fracture toughness. An analytical model has been developed for simulating the behavior of stitched double cantilever beam specimen under various loading conditions. For z-directional load and moment about the y-axis the numerical solutions are compared with the exact solutions. The derived formulation shows good accuracy when the relative error of displacement and rotation between numerical and exact solution were calculated. Thus we can use the present model with confidence in analyzing other problems involving stitched beams.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.04a
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• pp.646-650
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• 1996

In this paper, A hydrostatic bearing spindle for high precision machining and a motor built-in spindle for high speed machining are developed toobtain the high precision machining accuracy of the prototype lathe. The sliding bearing with fluoric resin (turcite) pad is adopted for improving the damping charateristics of guide ways. The funning accuracy of moving elements isestimated to confirm the validity of application on the prototype; the high precision CNC lathe. The surface roughness of Cupper and Aluminum machined by the hydrostatic spindle are 0.07 .mu. m and 0.10 .mu. mRmax. The surface roughness of Aluminium machined by the built-in spindle are 0.10 .mu. mRmax. From this results, it is venified that the prototype lathe is effective to high precision maching.

• Proceedings of the Acoustical Society of Korea Conference
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• 1998.08a
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• pp.250-253
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• 1998

In digital communicatioin networks, speech recognition systems conventionally reconstruct speech followed by extracting feature [parameters. In this paper, we consider a useful approach by incorporating speech coding parameters into the speech recognizer. Most speech coders employed in the networks represent line spectral pairs as spectral parameters. In order to improve the recognition performance of the LSP-based speech recognizer, we introduce two different ways: one is to devise weighed distance measures of LSPs and the other is to transform LSPs into a new feature set, named a pseudo-cepstrum. Experiments on speaker-independent connected-digit recognition showed that the weighted distance measures significantly improved the recognition accuracy than the unweighted one of LSPs. Especially we could obtain more improved performance by using PCEP. Compared to the conventional methods employing mel-frequency cepstral coefficients, the proposed methods achieved higher performance in recognition accuracies.

• Journal of Industrial Technology
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• v.30 no.B
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• pp.49-54
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• 2010

E-learning has the potentials to provide educational publicity and equality, and has been deployed rapidly in many areas of our society. Growth of e-learning market is also rapid and sustained. However, for e-learning to be a good solution, enough contents should be provided, for which sharing limited contents in the early deployment stage should be necessary. In this paper, we survey some activities about contents sharing. On the other hand, there have been many complaint from e-learning about its effectiveness. Therefore, in this paper, based on the poll results on concentration and satisfaction of e-learning, we also study practical ways to improve studying efficiency of e-learners.

• 한국태양에너지학회:학술대회논문집
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• 2012.03a
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• pp.299-304
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• 2012

In terms of plane structure, tower-type apartments have several disadvantages compared to flat-type apartments in the aspect of ventilation rate. Such disadvantages may not produce good indoor cooling effects with natural ventilation inside the heated apartments in hot summer days, so they may cause high energy consumption by an increase in cooling load. The purpose of this study is to investigate ways for improving the indoor thermal environment of tower-type apartments in summer by conducting quantitative evaluations of the airflow distribution in households.

• Hwankyungkyoyuk
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• v.14 no.1
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• pp.145-165
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• 2001

Offered in this paper are basic materials for development of teaching-learning programs and ways for improving energy education in elementary schools. The purpose of this study is to, firstly; analyze energy education-related contents of the seventh elementary curriculum, secondly; examine the status and needs of energy education through the investigation of questionnaire subject to teachers and students of model schools for energy education and schools, which were the model schools of energy education before. A total of 1,1635 responses (315 teachers; 1,320 students from 42 elementary schools) were analyzed through the frequency-analysis of SPSSWIN program.

• Korean Journal of Child Studies
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• v.37 no.3
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• pp.123-133
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• 2016

Objective: The aim of this study was to achieve a qualitative understanding of childcare teachers' cooperation experiences with Nuri curriculum teaching assistants. Methods: The study adopted a qualitative research design. Participants comprised 23 childcare teachers working with Nuri curriculum teaching assistants. Focus group interviews were conducted to discuss their cooperation experience with the teaching assistants. Qualitative themes analyses were carried out following individual-level analyses, group-level analyses, and cross-group-comparisons. Results and Conclusion: The results showed that childcare teachers, at first, had low expectation for Nuri curriculum teaching assistants because they have ambiguous job descriptions. However, the teachers' actual interactions exhibited cooperation effects on improving the quality of childcare. Childcare teachers suggested the ways to promote cooperation between childcare teachers and Nuri curriculum teaching assistants at individual and systemic levels.

• Korean Journal of Computational Design and Engineering
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• v.17 no.3
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• pp.164-174
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• 2012

The recent introduction of BIM technology has raised the interest on the BIM quality assurance and management more than ever. This study aims to consider the ways of BIM quality improvement by analyzing the most frequent issues rising from multiple BIM projects. For this purpose, the 12 test models from BIM education program hosted by buildingSMART Korea are investigated based on the requirements in the public BIM guidelines. All the BIM issues generated are categorized by the criteria applied and analyzed for each kind of building element. The results showed that more than half of the issued at least could be cleared out by improving modeling habits and technical guides.

• Journal of Crop Science and Biotechnology
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• v.10 no.3
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• pp.123-132
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• 2007

In this review, we discuss the ways in which our understanding of the controls of nitrogen use efficiency applied to crop improvement has been increased through the development of molecular physiology studies using transgenic plants or mutants with modified capacities for nitrogen uptake, assimilation and recycling. More recently, exploiting crop genetic variability through quantitative trait loci and candidate gene detection has opened new perspectives toward the identification of key structural or regulatory elements involved in the control of nitrogen metabolism for improving crop productivity. All together these studies strongly suggest that in the near future nitrogen use efficiency can be improved both by marker-assisted selection and genetic engineering, thus having the most promise for the practical application of increasing the capacity of a wide range of economically important species to take up and utilize nitrogen more efficiently.

• Journal of Educational Research in Mathematics
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• v.8 no.2
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• pp.509-526
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• 1998

school mathematics is based on the premise that teacher have extensively complex mathematics content and pedagogical content knowledge to employ teaching to facilitate students' conceptualization of mathematics knowledge. In this paper we have presented the realities of teacher education program about several countries and three source area in teaching school mathematics. As a result we suggest that for developing mathematics teacher education First, communities have to hold teachers in high esteem due to confucian heritage. Second, our university have t provide one year internship for training for practices and the use of interactive multimedia simulation. Third, college courses have to help students discard misunderstanding knowledge and briefs about mathematics and pedagogy they bring to the university. Fourth, our country have to reform teacher education system. Fifth, the government have to pay the tuition costs for more students.