• Elastomers and Composites
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• v.44 no.4
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• pp.442-446
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• 2009

Recovery behaviors of unfilled NR, BR, and SBR vulcanizates after aging with a circular deformation were compared to prevent the influence of reinforcing agent. Samples were aged at room temperature, 50, 70, and $90^{\circ}C$ for 10 days. Recovery increased by increasing the measurement time. Instantaneous recoveries less than 1.0 sec were obtained using the recovery variations with the measurement time. For aging at room temperature, difference in the recoveries of the rubber samples was not significant because the aging time was too short. However, for accelerated thermal aging at 50, 70, and $90^{\circ}C$, difference in the recoveries of the rubber samples was significant. Degree of recovery of BR specimen was higher than those of the others, while that of SBR was lowest. However, for accelerated thermal aging at $90^{\circ}C$, recovery of the NR sample was higher than that of the BR one. The initial recovery decreased by increasing the aging temperature and the decrement of SBR was larger than the others. The experimental results were explained with the resilience properties of rubbers and the crosslink density changes by thermal aging.

• Journal of the Society of Naval Architects of Korea
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• v.53 no.3
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• pp.228-236
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• 2016

Extraordinarily the establishment of towing tank has been initiated after the allocation of space at the basement floor of existing building through remodeling procedure. Therefore the asymmetric tank should be unavoidably determined by compromising with the allowable space and existing building structure. Consequently the shape of towing carriage ought to be selected as a cantilever type to match with the given environmental conditions. Finally the major role of the towing tank has been configured on the fundamental research work for the high speed marine vehicles. Due to the limited length of towing tank, it is appeared that the carriage should accelerated with 1.2m/sec² which is equivalent to twice of the maximum acceleration in ordinary practices on design application of carriage. In such a condition the exerted total power of motor could not be converted to traction force of the carriage without slip for the acceleration. To overcome these difficulties the contact pressure of a horizontal traction wheel to rail has been reinforced by the elastic recovery force of springs on supporting rollers. It is believed that the design experience of the high speed towing carriage under unusual circumferential condition and acceleration barrier could be utilized not only on the design of high speed towing carriage but also on the improvement of existing facilities.

• The Journal of the Korea Contents Association
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• v.10 no.1
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• pp.222-229
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• 2010

I study how the deviation of strong women clashes with patriarchism and the clash is represented in the films. Women of Spirit's in 1960's narrative deals with the generational conflicts and the older's defeat, and that reflects the changes of the times. The narrative of Horse-year Bride in 1960's deals with changes of housewives' status, deviation and return of the strong-willed women, and becoming 'a wise mother and good wife'. The Daughter-in-Law Born in the Year of Horse in 1970's has two meanings - rejecting the active women and reinforcing patriarchism. The narratives of these films mean the obedience to patriarchism and the punishment women for their activity. But, these films also show the pleasure of resistance by revealing the gap and the contradiction of patriarchism.

• The Journal of the Korea Contents Association
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• v.14 no.9
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• pp.227-235
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• 2014

The private security has achieved a rapid growth by playing an important role in supporting the public security. However, there are some negative results of this rapid growth. Violence committed by the private security is the biggest problem among them. This study discuss the necessity of eradicating violence committed by the private security, present some violence cases, and find solutions to the problem resulting from the cases. If violence committed by the private security is not eradicated, advancement in the private security service industry can not be expected. This study suggests the three possible solutions: reinforcing regulations restricting violence committed by the private security; strenthening the responsibility of the private security company (employer) for supervision and management on the private security guard (employee); establishing the philosophical identity of security service.

• Journal of Korea Technology Innovation Society
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• v.13 no.2
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• pp.310-331
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• 2010

Recently, US, EU and major development countries, including Korea, have set green growth strategy the for national robust economic growth. Green growth strategy was also adopted as economic stimulus policy. Korea also have established some policies for green growth such as Green Growth National Strategy and 5-years Plan. Thought the SMEs play an important role as the innovative driver that can supply material and components for final products, there are few policies for joining green growth strategy. So, the purpose of this paper is to explore the current extent of public procurement for technology-development products and propose the betterment of it. Firstly, we analyzed the public procurement-policies of major countries to kinds of policy-purposes and types including Korea. and then we deducted the needs to policy utilizing the public procurement for joining the SMEs to green growth strategy. Second, we proposed that the objects of purchase conditional public procurement policy be extent to the pre-commercial technologies. The pre-commercial technologies could be performed further R&D by some other compaines or pubic institutes. Considering the natures of green technology-such as quasi-public-, this improvement would be helpful for SMEs which could create initial-marketplace and sales-references.

• Journal of Korea Technology Innovation Society
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• v.15 no.2
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• pp.345-368
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• 2012

As science and technology are the core engines of economic and social affairs, it is becoming increasingly necessary to explore new promising technologies in order to secure competitiveness in science and technology with a view to helping upgrade the country's overall competitiveness and promoting industrial development. The governments of major advanced countries provide R&D support for promising future technologies. Even in South Korea, a study is being carried out to set up a model for forecasting future technologies and reinforcing the relevant survey system. This study intends to explore methods of identifying promising future technologies in the bio-science sector, which has emerged as a new growth engine. It will use a text-mining technique to collect and analyze theses in the bio science sector. It will identify key research sectors by analyzing thesis contour lines, and then review promising future key research subjects through in-depth study.

• Journal of the Korean Applied Science and Technology
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• v.33 no.1
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• pp.168-175
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• 2016

The surface of glass fiber bundle was modified with functionalized silanes and phenolic resin to improve the tensile strength as well as the adhesion of glass fiber to matrix phenolic resin. The surface modification of reinforcing glass fiber can play a significant role in controlling whole composite characteristics. We applied surface modification of glass fiber with two different functionalized silanes, such as glycidyltrimethoxysilane(G-silane) and aminopropyltriethoxysilane (A-silane), and phenol formaldehyde(PF) resin in one pot or separated process under different coating compositions and temperatures. Thermal treatment temperature is very important factor to improve the mechanical properties of modified glass fiber. Modified glass fiber bundle treated at $170^{\circ}C$ showed the highest tensile strength of $10.05g_f/D$. Surface analyses by scanning electron microscope(SEM) and FT-IR spectroscopy were used to characterize the surface coatings on glass fiber bundles. Mechanical property changes as functions of treatment conditions and coupling agent types were also explained.

• Journal of the Korea institute for structural maintenance and inspection
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• v.20 no.1
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• pp.118-125
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• 2016

This paper proposes the appropriate waterproofing methods for underground structures after applying different types of waterproofing materials on the concrete test specimens and selecting the best results out of humidity testing in winter conditions. Results of the testing showed that the underground structures absolutely require relevant waterproofing application based on the environmental conditions; when applied with interior waterproofing, the results showed that the concrete maintained high level of humidity and reinforcing steel within the concrete layer corroded. However, when applied with exterior waterproofing, it was shown that the waterproofing layer prevent direct contact with water and concrete, thereby protecting the concrete structure and improving overall durability. It follows that during underground structure construction, exterior waterproofing methods are have shown by an effective method for improving the durability as well as providing a comfortable interior environment for users.

• Journal of the Korea institute for structural maintenance and inspection
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• v.18 no.6
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• pp.41-49
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• 2014

In order to investigation splitting bond strength of the deformed longitudinal reinforcing bars in the R C members strengthened laterally with the external steel-band, a total 9 sets of test re-bars with and without active confining force given by the external steel-band are pulled monotonically until failure. Test results indicate that the bond strength becomes higher with the increase in number of steel-band sets and their initial stress magnitude. This is due to the active confining force given by the steel-band, and passive confining forces given by the steel-band and transverse reinforcements, in which the passive confinement effect varies depending on the magnitude of active confining force. An equation to estimate the splitting bond strengths for the R C members strengthened laterally with the external steel-band is developed based on the several experimental results of the present study.

• Journal of the Korea institute for structural maintenance and inspection
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• v.9 no.1
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• pp.101-111
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• 2005

In this study, it is investigated the modified modulus of elasticity of the reinforced concrete columns including the longitudinal reinforcing steels as well as the confinement effect of the core concrete due to the transverse reinforced steel through the literature reviews. Equations are derived in order to evaluate the modified modulus of elasticity for the reinforced compressive concrete including the confinement effect. The finite element analysis for the 20 story reinforced concrete building is undertaken as a case study depending on the steel ratio and modulus of elasticity, and the analysis results are discussed.