• Journal of Plant Biology
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• v.13 no.1
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• pp.65-69
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• 1970

Several days after culture, the parts around suspensor turned brown. In about 10 days the embryo started to form protocorm sending out hairs through seed coat. Around 20 days after culture, most of the protocorms emerged out of seed coat and some of them began to take green color. When observed two months after culture, the protocorn took the characteristic top-shape feature.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2009.10a
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• pp.395-396
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• 2009

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.11a
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• pp.819-820
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• 2010

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• v.5B no.3
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• pp.267-271
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• 2005

This paper deals with two kinds of novel shape switched reluctance motors (SRM) with magnetic barriers in order to improve operating performances of prototype. The magnetic barriers make rotor poles more saturated, and consequently inductance profiles are distorted. The changed inductance affects input current shape and eventually torque characteristics. In order to analyze the complicated flux pattern of the SRM with magnetic barriers and its terminal characteristics simultaneously, coupled field circuit modeling method is used. The finite element method is used to model the nonlinear magnetic field, and coupled to the circuit model of the SRM overall system. After experimental results are presented to prove the accuracy of the method, the several analysis results are compared, and the improved rotor shape is presented.

• Korean Journal of Materials Research
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• v.4 no.8
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• pp.927-933
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• 1994

The effect of particle shape and size on the settling characteristics in monodisperse suspensions of non-spherical particles was investigated. The slope index n values which was obtained from the plot of logarithm of settling rate vs. voidage were increased with the decrease of particle size because different amount of liquid could be adsorbed on irregular particle shape and/or size at same volume concentration. From the experimental results, an equation, $n_{i}=n(a+b/d_{v})$ where n is value of spherical particles, dv is minimum particle diameter and a, b are constants for characteristic of particles.

• Korean Institute of Interior Design Journal
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• v.21 no.4
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• pp.129-137
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• 2012

This study investigated the architectural characteristics and preservation status of traditional houses, designated as cultural assets in Jecheon. It aimed to provide basic information for cultural assets preservation policy in Jecheon by finding architectural characteristics of traditional houses. This study was conducted using the research methods of the existing literature and field survey to compare a current status of traditional houses. The result are as followings. Firstly, measures to protect the archetype of traditional houses are urgently needed. For systematic maintenance of local cultural assets, the relevant informations have to be constantly updated with ongoing management. Secondly, the site of traditional houses show the typical appearance of Baesanimsu(背山臨水). They were built with the hill or mountain in the north and agricultural land in the south. Types of placement are mostly closed type of 'ㅁ' shape. Thirdly, An-chae is found various type of 'ㄱ' shape, and Toet-khan was developed. Lastly, Sarang-chae is a mostly type of 'ㄴ' shape, and the traces of confucian thinking is found in floor plan.

• Transactions of the Korean Society of Mechanical Engineers
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• v.17 no.9
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• pp.2162-2171
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• 1993

Geneal Structure optimization is utilized to minimize the weight of structures while satisfying constraints imposed on stress, displacements and natural frequencies, etc. Sandwich structures consist of inside core and outside face sheets. The selected sandwich structures are isotropic sandwich beams and isotropic sandwich plate. The face sheets are treated as membrane and assumed to carry only tensions, while the core is assumed to carry only transverse shear. The characteristic of the varying area are considered by adding the projected component of the tension to the transverse shear. The bending theory and energy method are adopted for analyzing sandwich beams and plates, respectively. In the optimization process, the cost function is the weight of a structure, and a deflection and stress constraints are considered. Design variable are thickness and tapering coefficients which determine the shape of a structure. An existing optimization code is used for solving the formulated problems.

• 유체기계공업학회:학술대회논문집
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• 2002.12a
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• pp.227-233
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• 2002

It is common for highly loaded supersonic stage to have very high relative inlet Mach number. To get this level of inlet Mach number, rotor blade outer diameter or rotational speed should be increased. In the case of commercial turbo-fan engine, it is preferred to make the rotor blade outer diameter large than increasing the rotational speed. But, for multi-stage fan of military engines, overall diameter is often restricted and they are apt to increase the rotational speed. With high rotational speed, relative inlet Mach number is likely to be well supersonic over the entire rotor blade span and the characteristic of the stage is affected with meridional shape of the stage, especially at near hub or tip. In this paper, the aerodynamic performance of two different hub surface shape is compared and it's merit and demerits were discussed.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2002.04a
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• pp.670-674
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• 2002

In the recent years, as the research and the development of micro and precision machinery become active, the interest of micro actuators using SMA(Shape Memory Alloy) has been increased. The dynamic characteristic analysis of SMA is necessary for actuator application and many common researches report the material characteristics of SMA sufficiently. However, the research on dynamic characteristics is very deficient. In this paper, the helical spring are fabricated with NiTi SMA wire of high resistivity. The force, response speed, temperature, and displacement are measured by digital force gauge, infrared thermometer, and laser displacement sensor so that the dynamic characteristics of this SMA is analyzed. Also, bidirectional actuator was fabricated and experimented for its performance.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2004.04a
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• pp.155-159
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• 2004

In the recent years, as the research and the development of micro and precision machinery become active, the interest of micro actuators using SMA(Shape Memory Alloy) has been increased. The dydnamic characteristic analysis of SMA is necessary for actuator application and many common researches report the material characteristics of SMA sufficiently. However the research for dynamic characteristics is very deficient. In this paper, the helical suing are fabricated with NiTi SMA wire of high resistivity. The force, response speed, temperature, and displacement are measured by digital force gauge, infrared thermometer, and laser displacement sensor so that the dynamic characteristics of this SMA is analyzed. Also, bidicrectional actuator was fabricated and experimented for its performance.