• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.222-222
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• 2006

New types of constrained geometry complexes comprising rigid silacycloalkyl group incorporated into the bridging position between cyclopentadienyl and amido functionalities were prepared. The catalytic activities of olefin polymerization were influenced by the change of exo-cyclic ring size on bridge-head silacycloalkyl unit. It has been noted that the activities of this unique series increase with increasing size of the silacycloalkyl bridge and reach the maximum in six-membered silacyclohexyl-bridged CGC complex. It is noteworthy that conformation of silacycloalkanes gives rise to enhanced catalytic activity of the titanium center although the cyclic ring and titanium center are far remoted from each other.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2000.10a
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• pp.101-104
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• 2000

Milli-structure components are classified as component group whose size is between macro and micro scale. that is, about less than 20mm and larger than 1mm. The forming of these components has a typical phenomenon of bulk deformation with thin sheets because of the forming size. In order to conventional metal forming, where numerical process simulation is already idly applied, the micro-forming process is characterized by some scale effects which have to be considered in an advanced process simulation. milli-structure rectangular cup drawing is analyzed and designed using the finite element method and experiment. The result of the finite element analysis is confirmed by a series of experiment.

• Journal of Agricultural Extension & Community Development
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• v.24 no.1
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• pp.63-81
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• 2017

The purpose of this study is to analyze the changes of time series, the use by farm type and the causes of farm household debt. First, the mid and long term changes in farm household debt over the past 50 years have increased. Since 2010, the share of non-agricultural debt has exceeded the share of agricultural debt. Second, as a result of the analysis of the farm household debt use by farm type - full time&part time, farming type, land size, age, family members - there was a difference between the agricultural and the non-agricultural debt according to the type of farm household in a significant level of 1%. Finally, as a result of the cause analysis of the farm household debt, the related non-agricultural expenditure variables and the dummy variable of the manager's age, family member and land size has a common influence on the farm household debt increase.

• Journal of Environmental Science International
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• v.20 no.1
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• pp.71-79
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• 2011

In this study, a series of soil concrete mixtures were tested for the compressive strength according to ratio of aggregate to binder, compaction energy, maximum aggregate size, ratio of silica fume to cement, and ratio of water to binder. The optimum mixing ratio of soil concrete mixtures composed of volcaniclastic, cement, silica fume, concrete polymer and water were analysed. The test results for optimum proportion were as follows ; (1)ratio of aggregate to binder was 4 : 1, (2)compaction energy level was level 2, (3)maximum aggregate size was 13 mm, (4)ratio of silica fume to cement was 10%, (5)ratio of water to binder was 25%. Also, dry type construction techniques were applied using the optimum soil concrete mixture. From the results of this study, the compressive strength of soil concrete and construction techniques were suitable for making eco-friendly soil pavement.

• Proceedings of the Korean Geotechical Society Conference
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• 2006.03a
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• pp.752-759
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• 2006

Conglomerates and core-stones are the typical composite geomaterials that are composed of a weak matrix and a strong pebble part. In general, we couldn't analyze the composite geomaterials by using emperical rock classification methods. In the study, a series of analyses of elastic behavior of composite geomaterials are carried out by using homogenization theory. 45-case models are made with considering 3 kind of factors such as gravel content, size and strength of matrix. Those are applicable to various composite geomaterials of conglomerates and core-stones. The size of analysis model is large enough to exceed REV.

• Journal of the Korean Home Economics Association
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• v.18 no.4
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• pp.17-29
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• 1980

This study is to obtain the basic-standard for establishing the nominal size of 4∼6 year-old children's clothes. From the results of the data analysis, we found the following points. 1) Almost all the items with respect to children's age show the significant level (α=0.01 or α=0.05), and it was also shown that boys are bigger than girls. 2) The correlation among all the parts of the body is strong in the case of the stature and the weight. 3) The upper arm girth of children for this study is larger than that of japanese children, and the posterior shoulder width and the crotch to ankle of children for this study are smaller than that of japanese children. 4) In time series change this study shows that the average sizes have increased continuously.

• Journal of the Korean Chemical Society
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• v.16 no.3
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• pp.135-141
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• 1972

In the past years, a number of theories have been published to elucidate the structure of liquid water. common to most of these theories is that water mainly consist of several different kinds of clusters and also hydrogen bonds in water may be bent to some degree. Recentrly, in a series of paper, Jhon and Eyring successfully explained thermodynamic, dielectric, surface and transport properites of water, assuming that it contains small domains of about 46 molecules. According to the theory, the cluster size does not change with temperature, but the cluster concentration changes. In this paper, the potential function for the hydrogen bond, the dispersion energy and dipole-dipole interaction terms. The calculated results show that the domain of nearly 46 molecules is energetically most probable, and its size is independent of temperature. And also, we evaluated the effect of angel variation of the bent hydrogen bond. In addition, the relaxation energy different for ice and water is also explained by this method.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.9 no.3
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• pp.323-332
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• 1997

It was reported by some researchers that two-stage parallel-plate ESPs, commonly called electronic air cleaners, show decreasing behavior of collection efficiency as particle size decreases below about $0.03{\mu}m$. This phenomenon is attributed to partial particle charging characteristics, where some of incoming particles are not charged in the charging cell of 2-stage parallel-plate ESP. One way to improve the decreasing collection efficieny in that particle size range is to enforce particle charging quantity in the charging cell. In the present study, in order to do this a 2-wire series-type charging cell modified from a 1-wire normal-type one was suggested and investigated theoretically and experimentally concerning improvement of the collection efficiency. It was confirmed from the experimental and theoretical works that the collection efficiency was apparently improved.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.21 no.3
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• pp.197-202
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• 2008

In this paper, we proposed an analytical model for TFT which has series of the polycrystalline structures. An average speed is defined as carrier speed by the electric field. The effective square is suggested as the area of grain without depletion for the changed grain size. First, physical parameters such as grain size, channel lenght and trap density, have been changed to prove the validity of the average speed model and the value of the effective square has been estimated through drain-source current.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.625-630
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• 2008

In the manufacturing industries, viewing CAE analysis results is frequently required during the product development process for design verification. CAE data which include all related information of an analysis is, however, not efficiently shared among designers because CAE data size is in general large to deal with. In order to increase collaboration among designers this paper introduces the development of a CAE visualization system based on JT format exploiting for a large model visualization with a scene graph-based toolkit. Since CAE analysis results and JT format have different structure we developed a translator to convert the CAE result in binary format to the JT format. To show the effectiveness of JT format in showing the CAE result we also developed a prototype viewer offering basic functions provided by commercial systems. By using JT format we are able not only to reduce the size of analysis results, but to store a series of analysis results with several LOD in a data file.