• Computers and Concrete
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• v.18 no.2
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• pp.279-295
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• 2016

A new innovative composite material is textile reinforced cementitious composite (TRCC). To achieve high flexural performance researchers suggest polymer modification of TRCC matrices. In this study, nine ready mix repair mortars commonly used in construction industry and the production of TRCC elements were examined. Mechanical properties such as compressive and flexural strength, drying shrinkage were studied. Being a significant durability concern, alkali silica reaction tests were performed according to related standards. Results showed that, some ready repair mortar mixes are potentially reactive due to the alkali silica reaction. Two of the ready mortar mixes labelled as non-shrinkage in their technical data sheets showed the highest shrinkage. In this experiment, researchers designed new matrices. These matrices were fine grained concretes modified with polymer additives; latexes and redispersible powders. Two latexes and six redispersible powder polymers were used in the study. Mechanical properties of fine grained concretes such as compressive and flexural strengths were determined. Results showed that some of the fine grained concretes cast with redispersible powders had higher flexural strength than ready mix repair mortars at 28 days. Matrix composition has to be designed for a suitable consistency for planned production processes of TRCC and mechanical properties for load-carrying capacity.

• Journal of the Korea Concrete Institute
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• v.29 no.4
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• pp.361-369
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• 2017

Setting time of cement-based materials can represent a developing strength in early-age mixture, and it can be used a significant parameter of high-performance concrete having various mix-proportions. Generally, initial and final setting time of concrete is measured by penetration resistance method that used a wet-sieving mortar mixture, therefore, it hardly represents the setting time of sound concrete including coarse aggregate. Recently, several nondestructive methods, such as ultrasonic velocity and impendence measurement, are proposed to evaluate the setting time of fresh concrete. This study attempts to measure an electrical resistivity using four-electrode method for evaluation of setting time in early-age cement-based materials. For this purpose, total 10 mixtures are prepared as different mix-proportions including chemical admixture. Based on the experimental results, two electrical parameters, such as initial electrical resistivity and rising time, are proposed to reflect a microstructure development by hydration of cement-based materials. As a result, proposed parameter is also discussed with the measured setting time by penetration resistance method.

• Proceedings of the Korea Concrete Institute Conference
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• 1995.10a
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• pp.50-55
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• 1995

Recently, high-workable concrete has been developed and began to be used to a great extent in foreign countries, but it isn't familiar with and fully introduced in Korea yet. The aim of this paper is to suggest a reference data for the development of High-workable concrete according to the comparative analysis the effect of mix proportion (unit water sand/aggregate ratio) on the flowing characteristics. And also this paper aims to examine the compactability of High-workable concrete in a model wall-form.

• STI Policy Review
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• v.5 no.1
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• pp.34-56
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• 2014

This paper reviews the most central analytical and methodological issues that arise in developing national STI strategies. First, an outline of the relationship between national innovation systems and the strategic dimension is presented. The paper shows that science, technology and innovation strategy are often used in different forms and that there is no common understanding yet of the actual meaning and coverage of these strategies. The paper develops the terminology from a discussion of different approaches towards company innovation processes analyzing their evolution in different socioeconomic environments and the role and impact of science, technology and innovation policy on company innovation processes. Based on this conceptual understanding the paper defines national science, technology, innovation, and STI strategy and explains the basic terminology. From these definitions, the strategic dimension including the impact on the stakeholders is discussed. It is shown that a major success factor for STI strategy development is the involvement of stakeholders to vary and extend their use of their portfolio of instruments. Moreover it becomes evident that stakeholders follow their own interests which aren't necessarily in the interest of the national STI strategies. The analysis shows advantages and disadvantages as well as potentials and limitations of different approaches to develop STI strategies in their ability to describe the reality of innovation processes and to allow conclusions about the relationship between innovation policy and the innovation processes implemented by companies. It is shown that knowledge of these limitations is an important factor to consider in designing consistent and coherent national STI policy which aims at supporting innovation eventually. Finally the paper concludes that the STI policy mix concept needs a more systemic development approach which is integrated in the national STI strategy development and implementation.

• Asian Journal of Atmospheric Environment
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• v.8 no.1
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• pp.59-68
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• 2014

The Fukushima nuclear accident in 2011 had an extensive impact on the national electricity plans. This paper outlines alternative electricity scenarios that meet the goals of nuclear phase-out and greenhouse gas (GHG) emission reduction. This paper also analyzes the results of each scenario in respect to the electricity mix, GHG emissions, costs and employment effects. The Long-range Energy Alternatives Planning system (LEAP) model was used to simulate the annual electricity demand and supply system from 2011 to 2030. The reference year was 2009. Scenarios are reference (where existing plans are continued), A1, A2, B1, B2, and C2 (where the levels of demand management and nuclear phase-out are different). The share of renewable energy in the electricity mix in 2030 for each scenario will be increased from about 1% in 2009 to 8% in the reference scenario and from 11% to 31% in five alternative scenarios. Total cumulative cost increases up to 14% more than the reference scenario by replacing nuclear power plants with renewable energy in alternative scenarios could be affordable. Deploying enough renewable energy to meet such targets requires a roadmap for electricity price realization, expansion of research, development and deployment for renewable energy technologies, establishment of an organization dedicated to renewable energy, and ambitious targets for renewable energy.

• Journal of the Korea Fashion and Costume Design Association
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• v.6 no.3
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• pp.19-29
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• 2004

The current fashion market is experiencing a lot of difficulties in fashion forecasting due to consumers' fast-changing lifestyle on fashion, changes in consumer behavior, and the segmentation of the fashion market. To cope with this harsh reality, many fashion enterprises have paid much attention to the SPA (Specialty Retailer's Store of Private Label Apparel) brand as a promising fashion marketing strategy in terms of which they can survive in the extremely competing fashion market. The SPA brand is in the stage of inception in Korea, but the SPA brands such as MUJI and UNIQLO are already dominating the fashion business in Japan. Korea has just started developing the SPA brand, but its technological development, which was triggered by the success of 'BASIC HOUSE', is rapidly evolving. Under these circumstances, the SPA brand is getting vital for the fashion market in efficiently realizing consumers' requirements, revolutionizing the method for providing product information and the process of Marketing Mix Program, and expressing the value of shop. This paper studies the nature of the SPA brand and fashion merchandising system, and in turn examine the differences between the visual merchandising of the existing fashion brands and the Japanese SPA brands that are used as the fashion marketing strategy which is driven by the up-to-date technological system. Centering around these issues, we propose a visual merchandising system for fashion enterprises which serves to develop Korean-style SPA brands.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.10b
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• pp.961-966
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• 2000

It is difficult to change or remedy concrete structure after hardened. It is usual to evaluate the quality of hardened concrete using several test method. This study was performed to make fundamental data that could be used to evaluate the quality of hardened concrete. This study is to estimate mix proportion of hardened concrete. Each elements of concrete needed different estimation methods. First, the cement that handled by the most important compounds measured by XRF(X-ray fluorecence) machine with scanning Ca-K${\alpha}$. Second, the coarse aggregate that divided by maximum size measured by the area comparison method that starts from the assumption of uniform distribution. Third, the fine aggregate measured by the weight comparison method that needs several prerequsite constants which concerned cement hydration reaction. Fourth, the water content would be estimated by expert system that has data base of design data, the contents of above estimation results, the characteristics of concrete strength. As the result of the above research, some conclusions are as follows. The cement estimation method resulted by reliability of mean 96.7%, standard deviation 3.92. The area comparison method resulted by reliability of mean 95.3%, standard deviation 2.08. The weight comparison method resulted by reliability of mean 93.3%, standard deviation 3.35.

• International Journal of Highway Engineering
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• v.19 no.5
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• pp.77-88
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• 2017

PURPOSES : It is necessary to clarify the rheological properties of cement paste as a basic research in the development of mechanistic concrete mix design. The rheological properties of cement paste with different binder types, mix propositions, and with/without high range water reducers have been analyzed. METHODS : In this study, ordinary Portland cement, fly-ash, blast furnace slag, silica fume, and limestone powder were used as binders. The range of water-binder ratio was 0.3-0.5, and a total of 30 different mixes have been tested. The slump flow test, V-funnel test, and Dynamic Shear Rheometer (DSR) test were performed to analyze the rheological properties of cement paste. RESULTS : As a result of the slump flow test, it was found that the composition ratio of the binder contents greatly affected the paste flow when the high range water reducers were added. The results of V-funnel test showed that when the water-binder ratio was decreased without high range water reducers, the binder composition ratio had a large effect on the passing time of the V-funnel tester, but with high range water reducers the impact of the binder composition ratio was decreased. The slump flow and V-funnel have a certain relationship with the rheological factors (yield stress and plastic viscosity), but the correlation was not significant. Finally, we proposed the M-value considering the density and specific surface area of the binder. The correlation between rheological factors and M-value were better demonstrated than experimental values, but there is still a limit to predict the rheological factor in general mix design. CONCLUSIONS :In this study, the rheological properties of cement paste were analyzed. The binder type, composition ratio of binder, and with/without high range water reducers have combined to provide the complex effects on the rheological properties of cement paste. The correlation between the proposed M-value and rheological factor was found to be better than experimental results, but needs to be improved in the future.

• Geomechanics and Engineering
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• v.36 no.1
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• pp.39-50
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• 2024

Bitumen and high-quality subangular aggregates, the two principal materials used for asphalt concrete construction, are finite and expensive materials. The general availability of crumb rubber and naturally occurring aggregates of different shapes, especially flat and elongated shapes, indicates that they are feasible alternative materials for expanding the volume of bitumen and utilizing a wider range of aggregate shapes for the development of asphalt concrete, with an associated environmental benefit. The study investigated the effect of adding up to 15% crumb rubber and aggregates sorted into different groups, i.e., rounded, elongated, flat, and their combinations, on the rheological and mechanical properties and durability of 50/70 of hot-mix asphalt pavement. The addition of crumb rubber decreased ductility and penetration but increased the softening point. For a 5.5% bitumen content, asphalt concrete briquettes consisting of 7% crumb rubber and three types of aggregate shapes, i.e., 100% rounded, a mix of 75% rounded and 25% elongated, and a mix of 75% rounded, 15% elongated and 10% flat, were associated with high Marshall stability and indirect tensile strength as well as low lateral deformation due to their high solidity and moderate angularity ratio. Also, the addition of 7% crumb rubber resulted in a significant improvement in the tensile strength ratio and rebound strain of briquettes consisting of 75% rounded and 25% elongated aggregates and those with 75% rounded, 15% elongated and 10% flat aggregates. In relation to the parameters investigated, the three groups of briquettes met some of the local (South Africa) requirements for the surface course and base course of low traffic volume roads.

• Cartoon and Animation Studies
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• s.19
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• pp.145-159
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• 2010

Similar to the other cultural contents, the character industry is based on the media which acts as the technological background. In fact, the character industry is the process of that a created character accesses to the consumers via media, builds its value and becomes licensed as a brand in the market. Therefore, it is crucial to select the most effective media for the consistence of a character in the market, as well as for construction of a higher brand quality of the character. Today, "Webtoon" might be considered as one of the marketing means which utilizes the Internet media for raising the character as a brand. Webtoon has apparent strength because it can be produced in shorter period and with less expense than through other media. Furthermore, Webtoon can be simply featured by the easiness of two-way communication and transference to another media through it. For these reasons, and according to the result of analyzing some Korean Webtoons, it seems obvious that the most effective media in character marketing is the Internet. In addition to the Internet, the strategic development in the media-mix is also important for establishing a brand of a character. However, the effective media-mix is available only when the character's external identity meets with the trait of its media. For the purpose of learning how the media-mix works when a character reaches for the consumers, a character "Hamataeng" was born and used in the experiment. This study will explain the marketing process through the use of own-created Webtoon and other contents, and suggest the ways to build a brand of a character. In addition, it is also indicated that a media-mixing strategy for transformation and expansion of the character to other media.