• Proceedings of the KSR Conference
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• 2005.11a
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• pp.170-175
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• 2005

In this study, experimental and theoretical methods were applied to understand brake squeal noise VVVF rolling stock on tracks. Trailer cars needed to payed a particular attention, because they were the major source of brake noise. VVVF rolling stocks for lines no 1 of the subway system in Seoul were used for experimental analyses. In order to study brake squeal noise, a dynamometer test at the S&T Brake, Co., which was a manufacturer of brake pads had performed. For measuring vibration and noise, vibration tests of brake parts (brake lining, brake lining head, back plates, etc.) at the SNUT were executed. Also, vibration tests of disc assembly and lining block at the heavy maintenance shop of the Gunja depot were performed. The modal analyses by using an ANSYS which was one of the CAE commercial program were simulated to know the relationship to the mechanism of brake noise. On the based of the tests and the simulations it was found that specific frequencies of the brake parts affected squeal noise, and improvements for reducing squeal noise were proposed.

• The Mathematical Education
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• v.50 no.1
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• pp.119-128
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• 2011

In this paper, we studied into a qualitative research to see mathematical understanding of preschool and kindergarten's teachers such as feeling attitude, parents' concern, difficulty of math teaching in kindergarten field, teacher's role, type of feed back, beauty of math, relationship of real life, and self philosophy of math education. We selected 10 teachers whose career was 7~10 years. Because this research way is qualitative, we can new aspect that teacher want to break their ignorance for math. Moreover, they would like to learn about math practicality, application, and beauty from art in professional training. Therefore we assert that fusion math lecture would support in the professional training for teacher, preschool or kindergarten's president training, and remuneration training.

• Bulletin of the Korean Chemical Society
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• v.34 no.11
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• pp.3372-3376
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• 2013

The kinetic studies on the reactions of ethyl methyl (2) and ethyl propyl (4) chlorothiophosphates with X-pyridines have been carried out in acetonitrile at $35.0^{\circ}C$. The free energy correlations with X show biphasic concave upwards with a break point at X = H (2) and 3-Ph (4), respectively. A stepwise mechanism with a rate-limiting leaving group expulsion from the intermediate is proposed based on the magnitudes of selectivity parameters for both substrates. The considerably large values of ${\beta}_X$ = 1.50(2) and 1.44(4) with strongly basic pyridines and relatively small values of ${\beta}_X$ = 0.43(2) and 0.36(4) with weakly basic pyridines are interpreted as a change of the attacking direction of the X-pyridines from a frontside to a backside attack toward the chloride leaving group.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2006.05a
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• pp.185-187
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• 2006

This study deals with characterization and the application of magnetoelasticity as a device which measures existing steel stress. Available method of measuring existing stress needs break the concrete and cut the steel bar. But Proposed method doesn't need to cut the steel bar. A successful application of magnetoelasticity depends on the linearity of the relationship between the elastic and magnetic response due to loading. To investigate the correlation between two, steel bars are loaded in tension under uniaxial loading while the magnetic reading is recorded. Results showed linearity or partial-linearity of the elastic behavior of steel bars in relation to magnetic change. In the paper, the various factors affecting the measurements are also discussed.

• Bulletin of the Korean Chemical Society
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• v.33 no.10
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• pp.3203-3207
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• 2012

The nucleophilic substitution reactions of diisopropyl chlorothiophosphate (5) with X-pyridines have been kinetically studied in MeCN at $35.0^{\circ}C$. The Hammett and Br$\ddot{o}$nsted plots for the substituent X variations in the nucleophiles show biphasic concave upwards with a break point at X = 3-Ph. The pyridinolysis rate of 5 exhibits great negative deviation from the Taft plot. A concerted $S_N2$ mechanism is proposed involving a change of the attacking direction of the X-pyridines from a frontside attack with the strongly basic pyridines to a backside attack with the weakly basic pyridines.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2006.04a
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• pp.77-81
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• 2006

An attempt has been made to measure existing steel stress using magnetoelasticity. A device has been developed and used for the measurement of magnetism in response to the deformation of a steel bar. The proposed technique can be used for the assessment of existing reinforced concrete structures by the measurements of steel stress embedded inside concrete. A traditional technique requires to break the existing steel bar to measure existing strain. However, the proposed technique is developed to measure the stress without damaging the steel bar. A successful application of magnetoelasticity depends on the establishment of relationship between elastic and magnetic response due to loading. To investigate the correlation between the two, steel bars are loaded in tension under uniaxial loading while the magnetic reading is recorded. Based on the test results, equations are suggested to predict stress for steel bars with different diameters.

• Korea-Australia Rheology Journal
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• v.19 no.3
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• pp.133-139
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• 2007

Low density polyethylene nanocomposites were prepared by melt intercalating maleic anhydride grafted polyethylene and montmorillonite clay. It has been found that maleic anhydride has promoted strong interactions between polyethylene and montmorillonite, leading to the homogeneous dispersion of clay layers. Rheological experiments revealed that prepared nanocomposites exhibited shear thinning behaviour. Polyethylene nanocomposites exhibited an increase in steady shear viscosities compared to virgin polyethylene owing to strong polymer clay interactions. The tensile strength of nanocomposites was improved but elongation at break decreased considerably. Also, barrier properties improved significantly with montmorillonite content.

• Management & Information Systems Review
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• v.15
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• pp.37-50
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• 2004

Internet commerce has the potential to propel a company to 'break out' of existing strategic constraints and radically alter business processes, strengthen customer and supplier ties, and open up new markets. Therefore, many firms have rushed into internet commerce to conduct business more efficiently, create new business opportunities, and generate business value. The purpose of this study is to examine the relationship between the sales promotional functionality of internet shopping mall and its performance considering the characteristics of internet shopping mall's operational form as moderating variables. The results showed that the price functionality affects positive effects on the performance of shopping mall, and the characteristics of operational form can be considered as a significant moderating variables between the sales promotional functionality of shopping mall and the performance.

• Korean Institute of Interior Design Journal
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• no.29
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• pp.203-210
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• 2001

Major companies have launched into the film industry since 1990s, which resulted in competition in facilities. In addition, restriction for the number of the prints was removed. Under these circumstances, the cinema has been transformed and developed from the established one-hall cinema into multiplex cinema with large-scaled halls. Contrary to the established cinema, modern cinema are a cultural place within easy access. They accommodate diverse social and cultural needs and their functions have been extending gradually. The waiting areas should not function only as the waiting space for the audience but also the places to attract the audience and provide them with various cultural and art information, and temporary restful break. For this study, the inter-relationship between the structure of the area and the audience are identified objectively by analyzing audience distribution and their routes within the area. The purpose of the study is to provide basic data about the design of the waiting area based on the findings above.

• Proceedings of the Korean Society of Computer Information Conference
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• 2019.01a
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• pp.165-168
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• 2019

양자제도는 나라마다 고유문화와 인간사회 발전의 속도에 따라 변화하는 내용이 서로 같지 않지만 자녀의 복리를 최우선하는 '자를 위한 양자제도'가 범세계적인 추세임에는 틀림이 없다. 이 양자제도는 당사자간의 합의에 의하여 혈연적인 관계가 없음에도 불구하고 자가 양친의 친생자로서의 신분을 취득하는 법정혈족관계를 말한다. 특히 오랜 기간 전통적인 가의 계승을 위한 이 양자제도는 시행하는 과정에서 여러 가지 문제가 지적되어 자녀의 복리를 위하여 친부모와 친족관계를 단절시키고 양친과 친생자관계를 발생시키는 친양자제도가 2005년 민법개정을 통해 도입되었고, 2008년 1월 1일 시행하고 있다. 그러나 이 또한 민법에서 친양자 입양조건 및 부부공동 입양에 있어서 3년간이라는 혼인기간을 요구하는 등 엄격하게 규율하고 있어 친양자제도를 실현하는데 한계가 있다는 문제점이 대두되고 있는 실정이다. 따라서 본 연구에서는 먼저 우리나라 현행 친양자제도에 대한 법률적인 내용을 검토하고, 친양자제도와 관련한 외국의 입법례를 통하여 자의 복리를 위한 최선의 합리적인 개선방안을 제시하고자 한다.