• 한국생태학회:학술대회논문집
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• 1998.05a
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• pp.91-92
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• 1998

• Korean Architects
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• no.3 s.443
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• pp.12-14
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• 2006

• The Magazine for Energy Service Companies
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• s.18
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• pp.53-59
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• 2002

• KOREAN POULTRY JOURNAL
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• v.54 no.6
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• pp.165-167
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• 2022

• Journal of Korean Society of Steel Construction
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• v.21 no.2
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• pp.193-201
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• 2009

Structural design of most nonprismatic Pre-Engineered Building Systems (PEBS) is performed using optimizing software developed in foreign countries. In this study, a structural optimizing software for the design of 3-D structures of nonprismatic PEBS is developed according to the allowable stress design method of AISC2005 and KBC. Optimizing structural design with nonprismatic members is carried out by repeating the process of structural analysis and member design to minimize the weight of a structure. According to the optimizing design results of 2-D and 3-D structures with nonprismatic members, there are considerable steel savings in designing structures with nonprismatic H-shaped built-up sections rather than with H-shaped rolled sections. When H-shaped built-up sections were used, the weight of the structural steel was reduced when AISC2005 specification rather than AISC1898 was used in the design. It is therefore concluded that utilizing the new AISC2005 specification is safer in preventingweb buckling because the height of a member is designed to be small despite some differences depending on the structural type.

• Journal of the Korean Chemical Society
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• v.58 no.5
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• pp.478-489
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• 2014

The purposes of this study were to develop teaching strategy enhancing the activity to explore variables and to examine the instructional influences on students' creative thinking skills and critical thinking skills. In this study, a model using listing-excluding-controlling variables (DPAS model) was designed and applied to the existing 'Teaching model for the enhancement of the creative problem solving skills'. And it was implemented to preservice science teachers for the one semester. Results indicated that the experimental group presented statistically meaningful improvement in creative thinking skills, especially in recognizing problems, making hypothesis, controlling of variables and interpreting & transforming of data (p<.05). In addition, the strategy contributed to improve critical thinking skills, especially in making hypothesis and making conclusion & generalization (p<.05).

• Journal of Science Education
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• v.36 no.2
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• pp.251-262
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• 2012

In this study, we develop 15 learning programs to enhance the variable identification and control abilities for the middle school students and analyze the effect of the programs applied to the class. To increase the learning effect of the variable identification and control abilities, we design the programs so that the students can monitor their thinking processes and also they can evaluate the results from their cognitive activities objectively. We analyze the effect of the programs applied to the class and the results show that the test group, which uses the program, marks higher scores in the variable identification abilities compared to the control group. Also, the test group has the increased level of logic to control the variables. Especially, the effect is higher with the students who do not have any logic to control the variables. From the results, we know that it is possible to improve the variable identification and control abilities of the students through the meta-cognitive learning programs developed by us. Furthermore, the results show that the score of variable control abilities positively correlate with that of meta-cognitive level. It means that the meta-cognitive strategy meaningfully increases the variable control abilities of middle school students.

• Journal of Educational Research in Mathematics
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• v.20 no.3
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• pp.339-356
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• 2010

It is important for children to develop statistical reasoning as they think through data. In particular, it is imperative to provide children instructional situations in which they are encouraged to consider variability in data because the ability to reason about variability is fundamental to the development of statistical reasoning. Many researchers argue that even highperforming mathematics students show low levels of statistical reasoning; interventions attending to pedagogical concerns about child ren's statistical reasoning are, thus, necessary. The purpose of this study was to investigate 15 gifted elementary students' various ways of understanding important statistical concepts, with particular attention given to 3 students' reasoning about data that emerged as they engaged in the process of generating and graphing data. Analysis revealed that in recognizing variability in a context involving data, mathematically gifted students did not show any difference from previous results with general students. The authors suggest that our current statistics education may not help elementary students understand variability in their development of statistical reasoning.

• Applied Biological Chemistry
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• v.41 no.1
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• pp.18-22
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• 1998

A mutant strain which hyperproduced thermostable ${\alpha}-amylase$ was obtained by chemical mutagenesis of Bacillus licheniformis. The mutant strain, SK-5, produced the enzyme about 50 times higher than the original strain. The mutant was longer and slimmer in shape, slower in growth compared to the original strain. Nucleotide sequence analysis of the SK-5 ${\alpha}-amylase$ gene revealed no changes in the the structural gene. The changes found in the promoter region might be responsible for the hyperproduction of the enzyme by the mutant. No structural changes in the enzyme structure could be observed when the secreted enzymes at various culture times were analyzed by Western blot.

• Korean Journal of Microbiology
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• v.32 no.1
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• pp.70-77
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• 1994

The author isolated 7 mutant candidates which mapped around cysA (which was 10 o'clock). They were divided into two groups. One of them was located counterclockwise to cysA, and the other was clockwise to cysA. Since bldA was mapped counterclockwise to cysA, the candidate which mapped counterclockwise to cysA was transduced with phage containing wild type bldA gene clone. The candidates might be the alleles of bldA, because they were complemented by bldA clone. However some of such mutants sporulated very well and developed as much pigment as wild type on rich media plate. Their phenotype was not like bld mutant at all on such conditions. There were real antibiotics gene expressions, since transcriptional reporter gene xylE had shown high activities. Majority of the bldA like mutants showed act gene expressions when they were transformed with high copy number plasmid containing actII-ORF4.