• Proceedings of the Korea Association of Crystal Growth Conference
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• 1997.06a
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• pp.163-170
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• 1997

The MgO-doped LiNbO$_3$ single crystals were grown along c-axis by the Czochralski method with the pulling rate of 3mm/h and the rotation of 10rpm. The MgO contents were form 1 to 4 mole%. The SHG properties were investigated with the pulsed Nd:YAG laser, and thermo-optic coefficient, electro-optic coefficient of birefringence and curie temperature were measured. Phase matching temperature and Curie temperature increase similarly with MgO content until 4 mole%.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2009.10a
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• pp.250-253
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• 2009

In this study, the friction test was performed to find friction characteristics of advanced high strength steel (AHSS) sheets and the multiple regression method was employed to obtain friction models. The friction coefficients associated with the lubricant viscosity, drawing speed, and blank holding pressure are measured. Differently from GA steel sheets, the effects of the lubricant viscosity and pulling speed are a little, which are explained by a theory of adhesion and wear as well as a deformation of friction surface. In addition, the effects of friction parameters are numerically represented by friction regression models.

• The Journal of Korea Robotics Society
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• v.3 no.4
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• pp.315-322
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• 2008

A new soft finger mechanism using a spring as a backbone is proposed in this work. It is a 4 DOF mechanism that consists of a spring and 3 cylinders, which behave like joints with 3 up-and-down rotations and 1 left-and-right rotation. To control each joint, cylinders have small holes in their cross-sectional areas, and wires of different length are penetrated into these holes. We can control each joint by pulling the corresponding wire. The forward kinematics is solved by using the geometry of mechanism. And the relationship (Jacobian) between the linear velocity of the wires and the joint angular rate is obtained. A virtual simulator is developed to test the validity of the kinematic model. In the experiment, first, the position control is conducted by tracking a given trajectory. Second, to verify the flexibility and safety, we show that the soft finger deflects in a safe manner, in spite of the collision with environment.

• Proceedings of the IEEK Conference
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• 2001.06c
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• pp.209-212
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• 2001

In this paper, an intelligent notification system has been presented. The system operates on both wired and wireless internet. When a new message has been uploaded in a bulletin board systems(BBS) on HTTP web server, it sends the same message to their cellular phones of all members of a given group at the same time via SMS(Short Message Service). In addition, on reading SMS message, those who read them respond to a WAP server using pulling technique via wireless internet. Therefore, the HTTP server does know the members who did not read the message yet. Two different web servers, the HTTP server and the WAP server, running on a single system has been implemented. They share the single database which covers al1 related information about the BBS. The set of experiments shows that the notification system works well as we have expected Thus, we conclude that the proposed system that operates on both wired and wireless internet is the one of successful model for such environments.

• Journal of the Korean Society for Advanced Composite Structures
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• v.6 no.1
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• pp.59-66
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• 2015

In this study, structural stability of large diameter high density polyethylene (HDPE) pipe during installation was numerically investigated in order to investigate the effect of concrete collar dimension, water depth and tension (pulling force). From the numerical simulation results, the total stress of HDPE pipe with designed concrete collar was within 2.5%, so the total weight of concrete collar for sinking of HDPE is important rather than concrete collar dimension. Furthermore, the tension area for possible installation is decreased as the air filling rate is increased. Therefore, it is important to calculate the reasonable tension range before actual installation for safe installation of HDPE pipe.

• Fashion & Textile Research Journal
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• v.17 no.5
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• pp.681-690
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• 2015

Sustainability has been a important issue in fashion industry that reflects the modern phase of the time. More education institutions than ever before are beginning to offer specialized courses, certificates and degrees related to sustainability in fashion, and many fashion institutions are working to embed sustainability issues into the educational contents. In this study, I investigate how sustainability is being integrated into the curriculum of leading fashion institutions, corporate management activity across the world and overview the world leading educational programmes related to sustainable fashion, pulling out the unique expertise and areas of specialization for each institution. In conclusion, the sustainable fashion were still not widely promoted domestical fashion institutions compare with other foreign leading fashion institutions. This happens in fashion business as well. Korean fashion institutions have to make educational program and certificates and degrees related to sustainability because the educational program can transform domestic fashion industry to sustainable fashion leading country level.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.6
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• pp.1031-1034
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• 2007

Electric transmission lines pass through a variety of area. Foundation supporting the conductors and tower are selected properly in accordance with external load, for example dead load, wind load, snow load, construction load etc, and topography and geology condition. Typical types of foundation are as follows: pad foundation for small load and hard soil or rock in mountainous area, pile foundation for medium or large load and soft soil in plain field area. This paper introduced cylindrical foundation design & construction for large load and mountainous area. This foundation failure mode against pulling-out show splitting failure by tensile force toward circumferential direction.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2000.04a
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• pp.15-19
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• 2000

Recently Western countries are now beginning to use ACM (Advanced Composites Material), in the construction industry Compared with existing construction materials, ACM possesses many advantages such as light-weight, high-strength, corrosion resistant property. Among other fabrication process of ACM, pultrusion is one of the promising one for civil infrastructure application. In this paper, the structural characteristics of pultruded GFRP strip and structural members of angle and tube type were studied. For the strip, parametric studies of pultrusion process has been carried out. Considered parameters were volume fraction, temperature, pulling speed and fiber orientations. For the pultruded angle and tube, compression test and buckling analysis has been carried out. The results were compared with calculated values using coded formulae

• Korean Journal of Child Studies
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• v.30 no.6
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• pp.297-308
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• 2009

The study abroad phenomenon at an early age in Korea is increasing steadily. Increasing social demand for global leaders, disappointment in Korean educational system and economic growth are motivating more students to study abroad. The study abroad is a social phenomenon that is widespread across all social status in Korea. This study tries to examine the phenomenon in respect to social, psychological, educational and economical perspectives and seek future research questions. The findings suggest ways to improve Korean educational system, support students currently or planning to study abroad and to re-adjust in Korea after they come back. A balanced perspective is necessary in viewing study abroad phenomenon, rather than preventing, implementing stronger pulling factors in Korean educational system. It is necessary to hold the study abroad as another educational opportunity.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.13 no.5
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• pp.222-229
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• 2003

InP crystal is an increasingly important semiconductor material in the application of long-wave optoelectronic and high frequency devices. The equilibrium vapor pressure of phosphorus at the melting point of InP is so high that the synthesis process is very difficult. Liquid-encapsulated Czochralski (LEC) pulling from the melt at high pressure is a generally favored technique to grow InP single crystals. This technique involves two steps: the synthesis of polycrystalline powder and the growth of single crystal from the melt at high pressure. This article reviewed the latest development in the preparation of InP crystal and the evaluation on the crystal quality.