• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.624-627
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• 2003

Microcontact printing (uCP) of alkanethiols on gold was the first representative of soft-lithography processes. This is an attempt to enhance the accuracy of classical to a precision comparable with optical lithography, creating a low-cost, large-area, and high-resolution patterning process. Microcontact printing relies on replication of a pattered PDMS stamp from a master to form an elastic stamp that can be inked with a SAM solution(monolayer -forming ink) using either immersion inking or contact inking. The inked PDMS stamp is then used to print a pattern that selectively protects the gold substrate during the subsequent etch.

• Journal of the Korean Institute of Telematics and Electronics C
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• v.35C no.5
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• pp.50-58
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• 1998

We propose an efficient face recognition system for controllinng the access to the restricted zone using both the face region detectors based on facial symmetry and the extended self-organizing maps (ESOM) which have sensory synapses and descriptive synapses. Based on the visual cues of the facial symmetry, we apply horizontal and vertical projections on elliptic regions detected by GHT(generalized hough transform) to identify all the face regions from the complex background.And we propose an ESOM which can exploit principal components and imitate an elastic similarity matching, to authenticate faces of the enlisted member. In order to cope with changes of facial experession or glasses wearing, etc, the facial descriptions of each member at the time of authentication are simultaneously updated on the discriptive synapses online using the incremental learning of the proposed ESOM. Experimental results prove the feasibility of our approach.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2000.04a
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• pp.187-191
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• 2000

High temperature creep behaviour of Al-5 wt% Mg alloy reinforced with 7.5% BN flakes was studied. The composite specimens showed two main creep characteristics : (1) the value of the apparent stress exponent of the composite was high and varied with applied stress (2) the apparent activation energy for creep was much larger than that for self-diffusion in aluminum The true stress exponent of the composite was set equal to 5. Temperature dependence of the threshold stress of the composite was very strong. Which could not be rationalized by allowing for the temperature dependence of the elastic modulus change. AIN particles which were incorporated into the Al matrix during fabrication of the composite by the PRIMEXTM method were found to be effective barriers to dislocation motion and to give rise the threshold stress during creep of the composite

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1997.10a
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• pp.134-141
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• 1997

A geometrically non-linear finite element formulation of spatial cable networks is presented using three cable elements. Firstly, derivation procedures of tangent stiffness and mass matrices for the space truss element and the elastic catenary cable element, and the isoparametric cable element are summarized. The load incremental method based on Newton-Raphson iteration method and the dynamic relaxation method are presented in order to determine the initial static state of cable nets subjected to self-weights and support motions. Furthermore, static non-linear analysis of cable structures under additional live loads are performed based on the initial configuration. Challenging example problems are presented and discussed in order to demonstrate the feasibility of the present finite element method and investigate static non-linear behaviors of cable nets.

• Journal of the Korean Ceramic Society
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• v.46 no.5
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• pp.497-504
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• 2009

DLC is considered as the candidate material for application of moving parts in automotive components relatively in high pressure and temperature operating conditions for its high hardness with self lubrication and chemical inertness. Different deposition method such as arc plating, ion gun plating and PECVD were used for comparing mechanical and tribological properties of each DLCs deposited on stainless steel with 1 um thick respectively. Among these 3 types of DLCs, the arc plated DLC film showed highest value for wear resistance in dry condition. From the results of analysis for physical properties of DLC films, it seems that the adhesion force and crack initiation modes were more important factors than intrinsic mechanical properties such as hardness, elastic modulus and/or roughness to the wear resistance of DLC films. Raman spectroscopy was used for understanding chemical bonding natures of each type of DLC films. Typical D and G peaks were identified based on the deposition method. Hardness of the coating layers were identified by nanoindentation method and the adhesions were checked by scratch method.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2015.05a
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• pp.92-93
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• 2015

The main purpose of this paper is to present the dynamic test method developed for measuring the elastic modulus of sound insulating coat. The test setup was devised based on the theoretical natural frequency of a simply-supported beam subject to free transverse vibration. A stainless steel beam was tested and the result showed a good compliance with the standard value listed in literatures. The result indicates that the test set up can serve as a quick, economical and suitable scheme to test non self-supporting materials.

• Geotechnical Engineering
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• v.9 no.4
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• pp.93-102
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• 1993

Soil structures which are constructed over the soft ground settle continuously by the self-weight of embankment for a long time. It is because of timetependent behaviours . consolidation and creep occurring simultaneously. This paper tries to determine the required parameters for analysis of the creep behaviour in marine clays and studied the effect of the confining stress and stress level on the creep parameters . As a result, it presents an equation for the determination of creep parameters according to stress level considering that elastic modulus El and creep parameter f are found to be affected by the applied stress level.

• Journal of Ocean Engineering and Technology
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• v.13 no.1 s.31
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• pp.51-61
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• 1999

When a structure is built on the ground under consolidation, the instant corresponding contact pressure which the upper structure exerts on the ground is established. But, as the consolidation of the ground proceeds, the contact pressure is changed because of the flexural rigidity of the upper structure. This varied contact pressure exerts influence on the consolidation behavior of the ground. And, this varied consolidation behavior exerts on the contact pressure in retum. This kind of interaction between the upper struture and the olwer ground under consolidation contimues till all the consolidation process in finished. So this problem cannot be defined as a linear problem. In this paper an approximation method which can analyse this non-linear interaction problem is proposed by the FEM.

• Journal of the Korean institute of surface engineering
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• v.52 no.6
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• pp.321-325
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• 2019

Triso-type coating layers of silicon carbide and graphite on UO₂ paticulate nuclear fuel were prepared by using fluidized bed type chemical vapor deposition and self-propagating high temperature synthesis methods to make a coated nuclear fuel of a power plant for hydrogen mass-production. The source and carrier gases were the mixture of methyltrichlorosilane and propane, and inert argon. Chemical analysis and microstructure observation showed that the coated layers were inner graphite, middle silicon carbide and outer graphite. The elastic modulus and nano-hardness of the silicon carbide layer were 503 [GPa] and 36 [GPa], respectively.

• Journal of the Korean Society of Clothing and Textiles
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• v.33 no.9
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• pp.1495-1505
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• 2009

This study analyzes how well-being lifestyle and functional textile knowledge effect the perception of high functional sports/leisure wear importance. A survey was conducted among male and female sports/leisure wear consumers aged 15 and over in the Daegu and Gyeongbuk area from May $12^{th}$ to June $2^{nd}$ 2009. A total of 288 responses were analyzed using descriptive statistics, factor analysis, and regression. As a result, 9 factors were determined as sub-elements of a well-being lifestyle. Knowledge levels for functional textiles were high in elastic, UV blocking, air permeable, and antibacterial properties. The perception of high functional sports/leisure wear importance was positively influenced by functional textile knowledge and two well-being lifestyle constructing factors ('self-confidence/affirmative thinking' and 'health/environment oriented eating habits').