• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2008.06a
• /
• pp.450-451
• /
• 2008

In this paper, we have designed the Anti-Reflection (AR) coating for 850, 1310 nm(multi type) and 1310, 1550 nm(multi type) wavelength ranges on the ferrule facet of special optical connector. The reflectance of the AR coated ferrule facet is designed under 5% for 850, 1310 nm(multi type) and 1310, 1550 nm (multi type). AR thin film was deposited by ion- assisted deposition in low temperature. The average return loss of the AR coated ferrule facet is 47.1 dB.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2008.06a
• /
• pp.176-177
• /
• 2008

이 논문에서는 $0.35{\mu}m$ 공정으로 제작된 MOSFET의 고주파 동작 특성을 분석하였다. Multi-finger 형태인 게이트 폭의 길이 변화에 따른 특성 변화를 BSIM3v3 모델과 외부 기생 파라미터를 포함한 lumped element를 이용해 모델링을 하였다. 또한 Multi-finger 게이트 구조에서 게이트 finger 수의 증가에 따라 생기는 특성 변화를 각각의 구조에 따라 추출된 주요 기생 파라미터의 변화를 통해 분석하였다.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.13 no.2
• /
• pp.170-176
• /
• 2000

The joints with multi-interfaces was expected to have low DC resistance compared with those with single interface. The small size joint specimens joined with Nb3Sn sub-cables were fabricated to investi-gate the DC performance in the range of 0 to 600A transport current without external magnetic field. The joints with multi-interfaces have a few n-Ohm resistance, which is much lower than that of single lap joint. Because the interfaces between sub-cables of multi-interfaced joint are more complicated than those of single-interfaced joint, the soldering condition between sub-cables is very effective on the joint DC resistance.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 1999.11a
• /
• pp.640-643
• /
• 1999

This paper presents the results of multi-stress chamber experiments done to examine the tracking and erosion performance of polymer insulator. Multi-stress testing is able to demonstrate deficiencies of polymer insulator materials and designs, including the nature of interfaces in insulation design. Therefore, multi-stress testing is believed to a suitable test for evaluating the aging performance of polymer insulator designs. We have nvestigated IEC 61109 Annex C for estimating long time performance of polymer insulator.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.13 no.5
• /
• pp.426-430
• /
• 2000

We have studied the field emission characteristics of multi-layered diamond-like-carbon (DLC) films deposited by vertical electrodes type plasma enhanced chemical vapor deposition with CH$_4$ and H$_2$ mixture. We deposited a thin layer of DLC on the p$^{+}$-Si substrate and then turned off plasma before another deposition of a new DLC layer. The thickness and the number of DLC layers are varied. The emission characteristics of multi-layered DLC films were compared with conventional one. The multi-layered DLC film shows higher emission current than conventional one.e.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2004.07a
• /
• pp.365-368
• /
• 2004

Charge compensation effects in multi-resurf structure make possible to obtain high breakdown volatage and low on-resistance in vertical MOSFET. In this paper, electrical characteristics of the vertical MOSFET with multi epitaxial layer is presented. Proposed device has n and p-pillar for obtaining the charge compensation effects and The doping concentration each pillar is varied from $5{\times}10^{14}\;to\;1{\times}10^{16}/cm^3$. The thickness of the proposed device also varied from $400{\mu}m\;to\;500{\mu}m$. Due to the charge compensation effects, 4500V of breakdown voltage can be obtained.

• Journal of the Korean Society of Safety
• /
• v.33 no.2
• /
• pp.1-7
• /
• 2018

The multi-scale analysis is more proper and precise for composite materials because of considering the individual microscopic structure and properties of each material for composite materials. The purpose of this study is to verify the validity of using palladium particles in carbon/fiber composites by multi-scale analysis. The palladium is a material for itself to detect leaking hydrogen by using the property of adsorbing hydrogen. The macroscopic model material properties used in this study are homogeneous material properties from microstructure. Homogenized material properties that are calculated from periodic boundary conditions in the microscopic representative volume element model of each macroscopic analysis model. In this study, three macroscopic models were used : carbon fiber/epoxy, carbon fiber/palladium, palladium/epoxy. As a result, adding palladium to carbon/epoxy composite is not a problem in terms of strength.

• Journal of Information Technology Applications and Management
• /
• v.19 no.3
• /
• pp.19-30
• /
• 2012

Material selection is a complex problem in the design and development of products for diverse engineering applications. This paper is aimed to present a fuzzy decision making approach to deal with the material selection in engineering design problems. A fuzzy multi criteria decision-making model is proposed for solving the material selection problem. The proposed model makes use of fuzzy TOPSIS (Technique for Order reference by Similarity to Ideal Solution) with trapezoidal numbers for evaluating the criteria and ranking the alternatives. And result is compared with fuzzy VIKOR (VlseKriterijumska Optimizacija I Kompromisno Resenje in Serbian, means Multi criteria Optimisation and Compromise Solution) which is proposed by Jeya Girubha and Vinodh [2012]. The present paper is aimed to also improve literature of fuzzy decision making for material selection problem.

• KSTLE International Journal
• /
• v.4 no.1
• /
• pp.27-30
• /
• 2003

The basic principles of tribo-systems and study method based on tribe-systems are introduced in the paper, Based on the viewpoint of tribe-systems, the experiment on tribology characteristics of friction lining material in multi-rope friction hoist is carried out. The research result shows: tribology characteristics of friction material are not its inherent characteristic but system characteristics of the tribo-systems, the“sliding-rope”of multi-rope friction hoist can be divided into“safety sliding-rope”and“fault sliding-rope”, study on friction material only based on characteristic of system where friction material exists possesses practical significance.

• Structural Engineering and Mechanics
• /
• v.33 no.3
• /
• pp.285-306
• /
• 2009

In the literature the problem of the topology optimization of the structure is usually solved for one, clearly described from the mechanical point of view material. Generally the topology optimization answers the question of the distribution of this mentioned above material within the design domain. Finally, material-voids distribution it is obtained. In this paper, for the structure mainly strengthened or sometimes weakened by the inclusions, the variation approach of the topology optimization problem is formulated. This multi material approach may be useful for the design process of various mechanical or civil engineering structures which need to be more "refined" and more "optimal" than they can be using previous topology optimization procedures of optimization one material structures.