• Journal of the Korea Concrete Institute
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• v.26 no.4
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• pp.517-524
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• 2014

Nitrite-Type hydrocalumite (calumite) is a material that can adsorb chloride ions ($Cl^-$) that cause corrosion of reinforce bars and liberate the nitrite ions ($NO_2{^-}$) that inhibit corrosion in reinforced concrete. In this study, polymer-modified mortars using two types of epoxy resin with calumite are prepared with various polymer binder-ratios of 0, 5, 10, 15, 20% and calumite contents of 0, 5%. The specimens are tested for chloride ion penetration, carbonation, drying shrinkage and corrosion inhibition. As a result, the chloride ion penetration and carbonation depth of PMM using epoxy resin somewhat increases with increasing calumite contents, but those remarkably decreases depending on the polymer-binder ratios. The 28-d drying shrinkage shows a tendency to decrease with increasing polymer-binder ratio and calumite content. Unmodified mortars with calumite content of 5% did not satisfy quality requirement by KS. However, it was satisfied with KS requirement by the modification of epoxy resin in cement mortar. On the whole, the carbonation and chloride ion penetration depth of epoxy-modified mortars with calumite is considerably improved with an increase in the polymer-binder ratio regardless of the calumite content, and is remarkably improved over unmodified mortar. And, the replacement of the portland cement with the calumite has a marked effect in the corrosion-inhibiting property of the epoxy-modified mortars.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2012.03a
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• pp.89-89
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• 2012

선행 연구에서는 m-Aramid와 p-Aramid의 Ring 방적사/Core 방적사 조건에 따른 방적사 물성에 대해서 연구하였는데, Ring 방적사의 혼용율, 스핀들 속도에 따른 물성 변화, Core 방적사의 공정특성에 따른 방적성, 피복성에 대해 연구를 하였다. 그 결과 Ring 방적사의 경우 m-Aramid의 혼용율이 증가할수록 사 강도는 증가하는 경향을 확인할 수 있었고, 스핀들 속도가 증가함에 따라서 불균제도 및 사결점이 다소 증가하였다. Core 방적사의 경우 Core에 p-Aramid를 사용했을 때 방적성과 피복성은 양호 하였지만, 강한 p-Aramid에 의해 톱 롤러코트의 마모가 되는 경향을 볼 수 있었다. 본 연구에서는 Ring 방적사/Core 방적사에 대해 좀더 구체적인 제조공정조건에 의한 물성 변화를 알아보았고, 좀더 다양한 섬유소재를 적용해서 제조하였다. Ring 방적사의 경우 p-Aramid 혼용율에 따른 실험을 하였는데, m-Aramid에 대한 p-Aramid의 혼용율을 0%, 5%, 10%, 20% 로 하여 Ne30을 제조하였으며, Core 방적사는 Core를 p-Aramid 200D로 하고 Sheath를 Cotton으로 하여 Core 공급속도비 (1.06, 1.10, 1.14), 연계수(T/M, 3.8, 4.0, 4.2), Sheath/Core 혼섬율(70/30, 60/40, 50/50)에 따라 제조하였다. 추가로 Core 방적사는 Sheath에 Cotton 대신 FR-Rayon과 선염 Cotton을 사용하여 각각 Sheath/Core 혼섬율 70/30의 비율로 방적사를 제조하여 다양한 소재에 따른 방적사의 물성을 측정하였다. 제조된 시험 원사들의 측정 물성은 번수(Ne), 균제도(U%), 사결점(IPI), 강력(cN), 신도(%), 비강도(cN/Tex) 등이며, 편직을 통해 편성물의 외관을 확인하였다. Ring 방적사의 경우 p-Aramid의 혼용율이 증가할수록 강도는 완만하게 증가한 반면, 신도는 급격하게 감소하였다. Cotton Core 방적사의 경우는 공급속도비가 높아질수록 균제도가 높아지는 것을 볼수 있었고, Core 공급속도비가 높아질수록 외관상 피복도는 높아진 것을 볼 수 있었다. 이렇게 연구된 Aramid 소재를 이용한 방적사 제조 공정조건변화에 따른 물성 및 피복도 결과는 기존 방적업체에서 Aramid를 이용한 방적사 제조시에 공정조건을 확보하는데 도움이 될 것이라 생각되며, 방적사 시제품 생산시에 발생할 수 있는 시행착오를 줄임으로써 시제품 제조를 위한 생산비용의 Loss를 절감할 수 있을 것으로 예상된다.

• Journal of KIISE:Software and Applications
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• v.37 no.2
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• pp.104-109
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• 2010

The lighting reflection is a common problem in image analysis and causes the many difficulties to extract distinct features in related fields. Furthermore, the problem grows in the rainy night. In this paper, we aim to remove light reflection effects and reconstruct a road surface without lighting reflections in order to extract distinct features. The proposed method utilizes a 3D analysis based on a multiple geometry using captured images, with which we can combine each reflected areas; that is, we can remove lighting reflection effects and reconstruct the surface. At first, the regions of lighting sources and reflected surfaces are extracted by local maxima based on vertically projected intensity-histograms. After that, a fundamental matrix and homography matrix among multiple images are calculated by corresponding points in each image. Finally, we combine each surface by selecting minimum value among multiple images and replace it on a target image. The proposed method can reduces lighting reflection effects and the property on the surface is not lost. While the experimental results with collected data shows plausible performance comparing to the speed, reflection-overlapping areas which can not be reconstructed remain in the result. In order to solve this problem, a new reflection model needs to be constructed.

• Journal of the Korea Institute of Building Construction
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• v.12 no.3
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• pp.275-283
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• 2012

Nitrite-type hydrocalumite (calumite) is a material that can adsorb the chloride ions ($Cl^-$)that cause the corrosion of reinforcing bars and liberate the nitrite ions ($NO_2{^-}$) that inhibit corrosion in reinforced concrete, and can provide a self-corrosion inhibition function to the reinforced concrete. In this study, VA/E/MMA-modified mortars with calumite were prepared with various calumite contents and polymer binder-ratios, and tested for corrosion inhibition, chloride ion penetration, carbonation and drying shrinkage. As a result, regardless of polymer-binder ratio, the replacement of ordinary Portland cement with hydrocalumite has a marked effect on the corrosion inhibiting property of the polymer-modified mortars. However, chloride ion penetration and carbonation depths are somewhat increased with higher calumite content, but can be remarkably decreased depending on the polymer-binder ratios. The 28-d drying shrinkage shows a tendency to increase with the polymer-binder ratio and calumite content. VA/E/MMA-Modified mortars with 10 % calumite did not satisfy KS requirements. Accordingly, a calumite content of 5 % is recommended for the VA/E/MMA-modified mortars with calumite.

• KDI Journal of Economic Policy
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• v.26 no.2
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• pp.63-104
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• 2004

Economists have long been involved in various studies, theoretical and empirical, on the economic gains from innovative activities and as their outcome, intellectual properties. In Korea, however, research in this field has experienced rather slow progress, partly due to the lack of data availability and the awareness of its importance. This study attempts to measure the economic impact of patents on market value of firms from a microeconomic point of view. Analyses are performed to examine the ex-ante market valuation of patent acquisition activities by investigating the effect of patent acquisitions on daily stock prices as well as on annual market values. The study on the effect of a disclosure of granted patents on daily stock prices reveals that the economic value of a firm's patent acquisition is fairly high. The study on listed firms also reveals that a firm's patent registration stock has a positive and statistically significant effect on its year-end market value. Therefore, it can be concluded that the analysis performed in this study supports the validity of Korea's current patent system. The result, however, does not guarantee the optimality of current system. Studies on various aspects of intellectual property should follow to shape the system into a socially optimal one.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.8
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• pp.1085-1090
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• 2002

Genetic parameters for birth weights (BWT), calving ease scores observed from calves born by heifers (CEH), and calving ease scores observed from calves born by cows (CEC) were estimated using Bayesian methodology with Gibbs sampling in different threshold animal models. Data consisted of 77,458 records for calving ease scores and birth weights in Gelbvieh cattle. Gibbs samplers were used to obtain the parameters of interest for the categorical traits in two univariate threshold animal models, a bivariate threshold animal model, and a three-trait linear-threshold animal model. Samples of heritabilities and genetic correlations were calculated from the posterior means of dispersion parameters. In a univariate threshold animal model with CEH (model 1), the posterior means of heritabilities for calving ease was 0.35 for direct genetic effects and 0.18 for maternal genetic effects. In the other univariate threshold model with CEC (model 2), the posterior means of heritabilities of CEC was 0.28 for direct genetic effects and 0.18 for maternal genetic effects. In a bivariate threshold model with CEH and CEC (model 3), heritability estimates were similar to those in unvariate threshold models. In this model, genetic correlation between heifer calving ease and cow calving ease was 0.89 and 0.87 for direct genetic effect and maternal genetic effects, respectively. In a three-trait animal model, which contained two categorical traits (CEH and CEC) and one continuous trait (BWT) (model 4), heritability estimates of CEH and CEC for direct (maternal) genetic effects were 0.40 (0.23) and 0.23 (0.13), respectively. In this model, genetic correlation estimates between CEH and CEC were 0.89 and 0.66 for direct genetic effects and maternal effects, respectively. These estimates were greater than estimates between BWT and CEH (0.82 and 0.34) or BWT and CEC (0.85 and 0.26). This result indicates that CEH and CEC should be high correlated rather than estimates between calving ease and birth weight. Genetic correlation estimates between direct genetic effects and maternal effects were -0.29, -0.31 and 0.15 for BWT, CEH and CEC, respectively. Correlation for permanent environmental effects between BWT and CEC was -0.83 in model 4. This study can provide genetic evaluation for calving ease with other continuous traits jointly with assuming that calving ease from first calving was a same trait to calving ease from later parities calving. Further researches for reliability of dispersion parameters would be needed even if the more correlated traits would be concerned in the model, the higher reliability could be obtained, especially on threshold model with property that categorical traits have little information.

• Journal of Korea Technology Innovation Society
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• v.15 no.2
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• pp.242-261
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• 2012

Early stages of technology valuation have been often overlooked or under-represented. The early stage technologies are even riskier due to their inadequacy of commercial development and market applicability. More than 95% of patents fail to earn any revenues so that the majority of patents were valueless. Technology transfers from laboratories at universities and research institutes to industrial firms have increased to acquire value from invented technologies. Technology transfer, a process of transferring discoveries and innovations resulted from research to commercial sectors, typically comprises several steps: disclosing the discoveries and innovations, i.e., intellectual property (IP), evaluating the IP's economic prospects, securing a patent, copyright or trademark for the IP, commercializing the technology through licensing, forming a joint venture, or selling. At each of those stages in the research and development of technology, the value of technology would play a very important role of making decision on the movement toward the next step, however, the financial value of technology is not easy to determine due to a great amount of uncertainty in the course of research and development, and commercialization. This paper refers to technology embodied as devices, equipment, software or processes primarily developed at public research institutions such as universities. Sometimes it is also as the result of externally financed projects contracted with industry. Nearly always technology developed at public research entities results in laboratory prototypes. When it is required to define the technology transfer contract terms for the license of the university patrimonial rights to external funding companies or other interested parties, a question arises: what is the monetary value? In this paper, we present a method for technology valuation based on the identification of specific value points related to its development. The final technology value must be within previously defined value limits. This paper consists of the review of issues related to technology transfer and commercialization, the identification of characteristics of technologies in the early stage of technology development, the formulation of framework of methods to value the early stage technologies, and the conclusion and implication of the previous review.

• Elastomers and Composites
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• v.36 no.2
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• pp.111-120
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• 2001

Mechanical properties and their adhesion behavior with zinc- and brass-plated steel cords of natural rubber/acrylonitrile-butadiene blend compounds were investigated as a function of blend ratio. The Mooney viscosity and stress relaxation time were found to be lowered with increasing NBR content. Tensile modulus generally increased with increasing NBR content. Tensile stress at break stayed constant up to about 40 phr and showed minimum at $50{\sim}60 phr$, and thereafter increased with increasing NBR content. Strain at break decreased linearly below 50 phr, and above the level it showed nearly constant value. Based on the abrupt drops in elastic modulus and tan ${\delta}$ peak, the glass transition temperature of NR and NBR were found to be -55 and $-10^{\circ}C$, respectively. In the case of NR/NBR blend compounds, two distinct transition points were observed and each transition position was not affected by NBR level indicating an incompatible nature of NR/NBR blend system. The pullout force and rubber coverage decreased to the level of about 40% to that of pure m compound, when the 50 phr of NR was replaced by NBR. However, the pure NBR compound showed the comparable adhesion performance with NR(${\sim}90%$). The sulfur concentration was found to become lower with the increased NBR content at the adhesion interface based on the Auger spectrometer results, representing a lack of adhesion layer formation, and this was explained for a possible cause of low adhesion performance with adding NBR.

• Tunnel and Underground Space
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• v.23 no.3
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• pp.180-191
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• 2013

The purpose of this research was to find an optimal quarrying for marble by analyzing the applicability and the work efficiency of a chain saw machine newly introduced in the underground Baekwoon mine. From the test results of the physical properties of Baekwoon marble, which affects the efficiency of rock cutting, it was found to have similar physical characteristics as the ones which are now being produced in the other areas in Korea. And especially it shows isotropic property, which can be thought to be advantageous as a dimensional stone. To check the long-term quality of the marble as a stone material, several tests such as corrosion resistance test and abrasion test were carried out. It was found to be vulnerable to acid rain with decrease of weight and seismic wave velocity after applying artificial rain at pH 5.6 for 50 times. The percentage of wear from abrasion test was 22.67%. The working time and cutting speed of the chain saw machine were recorded and analyzed during the test-run at the quarry. The overall work cycle was assorted into 9 unit operations and the operating time per each unit was drawn. The operating times for the two cutting patterns, which could be possibly applicable to the work site, were compared. The results indicated that the pattern B, that the cutting sequence was set to minimize the movement of the machine, showed 6% less working hours than the pattern A, which first cuts the outer boundary. With cutting pattern analysis, the ore body in the Baekwoon mine was 3 dimensionally modeled and a quarrying plan considering the existing conditions of the marble was suggested.

• Geomechanics and Engineering
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• v.17 no.4
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• pp.333-342
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• 2019

Geological dynamic hazards during coal mining can be caused by the failure of a composite system consisting of roof rock and coal layers, subject to different loading rates due to different advancing velocities in the working face. In this paper, the uniaxial compression test simulations on the composite rock-coal layers were performed using $PFC^{2D}$ software and especially the effects of loading rate on the stress-strain behavior, strength characteristics and crack nucleation, propagation and coalescence in a composite layer were analyzed. In addition, considering the composite layer, the mechanisms for the advanced bore decompression in coal to prevent the geological dynamic hazards at a rapid advancing velocity of working face were explored. The uniaxial compressive strength and peak strain are found to increase with the increase of loading rate. After post-peak point, the stress-strain curve shows a steep stepped drop at a low loading rate, while the stress-strain curve exhibits a slowly progressive decrease at a high loading rate. The cracking mainly occurs within coal, and no apparent cracking is observed for rock. While at a high loading rate, the rock near the bedding plane is damaged by rapid crack propagation in coal. The cracking pattern is not a single shear zone, but exhibits as two simultaneously propagating shear zones in a "X" shape. Following this, the coal breaks into many pieces and the fragment size and number increase with loading rate. Whereas a low loading rate promotes the development of tensile crack, the failure pattern shows a V-shaped hybrid shear and tensile failure. The shear failure becomes dominant with an increasing loading rate. Meanwhile, with the increase of loading rate, the width of the main shear failure zone increases. Moreover, the advanced bore decompression changes the physical property and energy accumulation conditions of the composite layer, which increases the strain energy dissipation, and the occurrence possibility of geological dynamic hazards is reduced at a rapid advancing velocity of working face.