• Tunnel and Underground Space
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• v.6 no.4
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• pp.298-305
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• 1996

Grouting technique is frequently used where a tunnel structure is passing through the shallow overburden area or where the thickness of hard rock above the tunnel is rather thin. However, engineering background on design process of the grout reinforcement does not seem to be fully understood until now. Mechanics of composite material is, therefore, introduced in this study to investigate the orthotropic material properties of the composites containing soil(or rock) and grouting material. These orthotropic material properties can be used to represent the reinfocement effects quantitatively. The model developed in this study is next applied to a typical tunnel structure and the grouting effect is analyzed numerically. The idea used in this study can be expanded to a situation where a pipe roofing or a forepoling technique is adopted and a simplified design procedure, similar to the model model introduced in this study, can be developed.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.11a
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• pp.281-284
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• 2000

For estimation manufacturing cost during the early design stage, desingers have to know compositon of manufacturmg cost. Manufacturing cost is summalion of material cost and processmg cost. To be able to control the manufacturmg cost, it is necessary to estimate the costs adequately and to store the cost data in a generic way. a generic system, which is the basis for the control of the production costs, takes into account geometric information, material information, process information and production planning information Manufacturing cost is summation of material cost and processing cost.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.05b
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• pp.61-64
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• 2000

An ultrasonic linear motor was composed of a slider and a stator vibrator including piezoelectric material and elastic material. The ultrasonic linear motors mainly consist of an ultrasonic oscillator which generates elliptical oscillations. Elliptical oscillations are generated by synthesizing two degenerated modes. The design of a stator for an ultrasonic linear motor was optimized with respect to vibration mode and direction of vibratory displacement by employing the finite element method. Applying multilayer piezoelectric ceramics. we found larger elliptical oscillations. The motors were designed by varying the width of stator vibrator and the thickness. the length and the position of multilayer piezoelectric ceramics.

• JSTS:Journal of Semiconductor Technology and Science
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• v.8 no.1
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• pp.92-97
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• 2008

In this Paper, we present a scaling theory for dual material surrounding gate (DMSGTs) MOSFETs, which gives a guidance for the device design and maintaining a precise subthreshold factor for given device parameters. By studying the subthreshold conducting phenomenon of DMSGTs, the effective conductive path effect (ECPE) is employed to acquire the natural length to guide the design. With ECPE, the minimum channel potential is used to monitor the subthreshold behavior. The effect of ECPE on scaling factor significantly improves the subthreshold swing compared to conventional scaling rule. This proposed model offers the basic designing guidance for dual material surrounding gate MOSFETs.

• Proceedings of the Korea Contents Association Conference
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• 2010.05a
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• pp.488-490
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• 2010

Recently demand for the titanium material has been increasing continuously, and the titanium material is being applied to various fields these days. Especially, in the jewelry filed, the diamond set titanium jewels begin to appear. In this paper, the authors introduce advanced material titanium jewels by various expression techniques and propose the wedding jewel design using titanium material, practical and 'ECO-Steel'.

• International Journal of Precision Engineering and Manufacturing
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• v.9 no.3
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• pp.64-67
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• 2008

This study investigated the influence of composite resins with different elastic moduli and occlusal loading conditions on the stress distribution of restored notch-shaped non-carious cervical lesions (NCCL) using 3D finite element analysis. Two different materials, Tetric Flow and Z100, were used as representative flowable hybrid resins for the restoration of NCCL. A static point load of 500 N was applied at the buccal and palatal cusps. The ratios of stress reduction to energy dissipation were better in the compressive state than the tensile state regardless of the restorative material. The total dissipation ratios for Tetric Flow were 1.5% and 4.2% larger than those for Z100 under compression and tension, respectively. Therefore, tensile stress poses more of a risk for tooth fracture, and Tetric Flow is a more appropriate material for restoration.

• Journal of KSNVE
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• v.8 no.5
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• pp.900-907
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• 1998

Rubber materials are extensively used in various machine design application, mainly for vibration/shock/noise control devices. Over the years an enormous effort has been put into developing procedures to provide properties of rubber material for design function. However, there are still a lot of difficulties in the understanding of dynamic characteristics of the rubber components in compression. In this paper, the dynamic characteristics of rubber materials for anti-vibration under compression were investigated. Dynamic and static tests for rubber material with 3 different hardness were performed. In dynamic tests, non-resonance method, impedance method, was used to obtain the complex modulus(storage modulus and loss factor) and the effects of static pre-strain on the dynamic characteristics were investigated. Also, a relation equation between linear dynamic and nonlinear static behavior of rubber material was discussed and its usefulness to predict their combined effects was investigated.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.25 no.6
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• pp.467-473
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• 2012

A functionally graded material (FGM) spacer, which the distribution of dielectric permittivity inside an insulator changes spatially, can considerably reduce the electric field concentration around a high-voltage electrode and along the gas-insulator interface when compared to a conventional spacer with a uniform permittivity distribution. In this research, we propose the FGM spacer with an elliptical permittivity distribution instead of that with a distribution of dielectric permittivity varying along a radial direction only in order to improve efficiently the insulation capability. The optimal design of the elliptical FGM spacer configuration is performed by using the response surface methodology (RSM) combined with the steepest descent method (SDM).

• Textile Coloration and Finishing
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• v.25 no.2
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• pp.140-151
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• 2013

In order to investigate the mechanical properties of working clothes materials considering industrial settings, the test weaving materials were compared with the existing materials depending on the season. The material design of the test fabrics were changed through fineness, composition, density of materials then subsequently treated with functional finish. As a result of evaluation of the forms according to KES-FB system, Koshi was deduced, and Numeri and Fukurami were increased. Thereby, the test weaving materials became flexible, surface became smoother, elasticity and volume characteristics indicated to have been improved. Consequently, the THV value of working clothes materials for test weaving was increased compared to existing materials which indicated improved result of the total hand value. Specially, the winter cloth material indicated improved drape characteristics and dimensional characteristics, showed improved liveliness as being compressed softly.

• Journal of the Korean Society for Precision Engineering
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• v.25 no.11
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• pp.95-99
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• 2008

Applications of composite materials in various engineering fields have been extended significantly. For being useful composite materials, we could modify the rigidity and strength characteristics of composite material according to structures and material direction. In this study, CFRP, which has been widely used in space leisure and general structural applications due to the weight, elasticity coefficient, high fatigue strength and lower thermal transformation ect, was selected. As the CFRP is an anisotropic material whose mechanical properties change with its stacking sequence or angle, special attention was given to the effects of the fiber orientation angle on the bending characteristics of CFRP fiat and CFEP square members. It's different on the each result of strength and rigidity of CFRP flat and CFRP square members.