• Journal of the Korean Chemical Society
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• v.55 no.3
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• pp.490-494
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• 2011

This paper reports the use of supplementary cementing materials (SCMs) derived from local resources, for the partial replacement of Portland cement to reduce $CO_2$ emission during cement production. Replacement of Portland clinkers up to 20 wt.% with SCMs in normal cements reduced $CO_2$ emission by 0.18 kg $CO_2$/kg. The compressive strength exceeded the standard specification for Portland cement ASTM C-150. Blended cement samples containing 20% Portland clinker replacement had compressive strengths of 37 MPa after 28 days of curing time. The microstructure evolution of blended cement at a composition of 80:20 was similar to that of the 100% Portland cement, where the structure between days 28 and 56 reached a steady state. Blended cements with compositions of 70:30 and 60:40 still showed progress of CSH plate formation and the lack of massive structure development. It is shown that the use of supplementary cementing materials could be as one of alternative ways to reduce $CO_2$ emissions during cement production.

• Journal of the Korean Ceramic Society
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• v.41 no.9
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• pp.690-695
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• 2004

In this study, inorganic (steel, asbestos and carbon) and organic (polyacryl and polyamide) fibers were used to investigate their reinforcing effects of the physical properties of Portland cement. From the load-displacement curve of each reinforced specimen, fracture strength, Young's module, fracture energy and fracture toughness were computed and compared with each other. In addition, the experiment of their impact toughness was carried out and compared with the fracture energy. For the improvement of fracture strength the inorganic (asbestos) fiber reinforcement was most effective, while the best reinforcing effect of impact toughness was achieved by organic (polyacryl) fiber. And steel fiber proved to be most adequate for improvement of both fracture strength and impact toughness. Steel fiber also showed the highest fracture energy and fracture toughness among all of the fibers.

• Defense and Technology
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• no.12 s.106
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• pp.56-57
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• 1987

• Korean Journal of Environmental Agriculture
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• v.26 no.3
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• pp.259-266
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• 2007

Enormous amount of zeolite by-products as a fine powder have been produced while manufacturing commercial zeolite products. Granulation of the zeolite by-products is necessary in order for them to be recycled as soil conditioners or absorbent for various environmental contaminants due to the limitations inherent from their physical properties. We granulated the zeolite powders using Portland cement as a cementing agent and characterized the physical and chemical properties of the granulated zeolite product. The experimental natural zeolite had a Si/Al ratio of 4.8 and CEC of 68.1 $cmol_c\;kg^{-1}$. The X-ray diffractometry (XRD) revealed that clinoptilolite and mordenite were the major minerals of natural zeolite. Smectite, feldspar and quartz also existed as secondary minerals. Optimum conditions of granulated zeolite production occurred when natural zeolite was mixed with Portland cement at a 4:1 ratio and granulated using the extruder, left to harden for one month at $25^{\circ}C$ and treated at $400^{\circ}C$ for 3 hours. The wide spectra of XRD revealed that the granulated zeolite had amorphous oxide minerals. The alkali- or thermal-treated natural zeolite exhibited pH-dependent charge properties. The major minerals of the granulated zeolite were clinoptilolite, mordenite and tobermorite. The buffering capacity and charge density of the granulated zeolite were greater than those of natural zeolite.

• Journal of the Korean Geographical Society
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• v.45 no.1
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• pp.49-74
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• 2010

Cities are major sources of greenhouse gas emissions but also suitable places for implementing proactive climate mitigation and adaptation strategies. Based on the interdisciplinary review of literature, we categorize the current discussion about urban climate mitigation and adaptation planning, policy and practices into four perspectives - sustainability science, global change science, multilevel governance, and structural engineering. While these four schools of thought have distinct perspectives rooted in different disciplinary lenses, our synthesis of the literature identifies several universal themes that are common to all of the perspectives in the context of combating threats posed by climate change. The Portland case study illustrates that a city can make changes to reduce greenhouse gas emissions and increase adaptive capacity to climate change impacts by implementing smart growth, devising local climate action plans that target emission reductions in various sectors, recognizing the interactions and influences of multiple scales of governance, and supporting the installation of various green infrastructures that contribute to green economy. Furthermore, a university can serve as a hub in this climate mitigation and adaptation arena by connecting various levels of community organizations in both public and private sectors, creating innovative research centers and spatially explicit green infrastructure, designing impact assessments and campus carbon inventories, and engaging students and the larger community through service learning.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2000.10a
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• pp.116-123
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• 2000

본 논문은 1995년 일본 남부 효고켄 남부 지진 (코베 대지진)에 의해 코베시에 위치하는 인공섬인 포트 아일랜등서 발생한 액상화 현상을 해석적 기법을 동원하여 액상화 현상의 저감 효과 혹은 방지를 위하여 실시되어져 오고 있는 여러 공법들의 타당성을 수치해석적인 입장에서 검증한 것이다. 따라서, 본 논문에서는 코베시에 의해 획득되어진 연직 방향의 지진 기록에 의해 포트 아일랜드 시공 당시 구역별로 다른 지반 개량 공법을 실시했고, 혹은 실시하지 않는 구역에 대해서 1차원 및 2차원 전응력 그리고 유효 응력 해석 기법을 동원하여 일련의 해석을 실시하였고 그 결과를 다각적인 방향에서 제시하였다.

• The Journal of the Korea Contents Association
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• v.15 no.9
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• pp.465-477
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• 2015

Today's companies build strong brand assets which, through the expansion of other business areas, promote efficient corporate management. Many companies manage brand assets among through a multitude of brand groups using brand portfolios rather than the single brand strategy. Such brand group influence can be related not only to brand group expansion, but also to parent company brands and product brand groups. The purpose of this study was to identify the effects of parent corporate brand associations on brand portfolio evaluation. The results of the present study is as follows: positive parent corporate brand image was revealed to play a positive role in brand portfolio evaluation. Parent corporate brand image provided endorsement for their product brands, and this can reduce consumer's decision cost on brand portfolio evaluations. This study focused on two types of brand relationship strategy : brand expansion strategy and individual brand strategy. With individual brand strategy, cases where parent company brands provided endorsement and cases to the contrary were studied separately. In cases where well-managed parent corporate brand image were able to provide endorsement in the case of individual brand strategy like that of brand expansion strategy.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 1998.10a
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• pp.287-305
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• 1998

This paper deals with the problem of port administration and management of the port of Pusan. As the port of Pusan has been administrated by central government, Efficiency of port is worse than other foreign ports. These include the time-lagged port development, the inconsistent port planning with city planning, the insufficient long-term port development planning, the various operating authorities and the lack of port sales activities etc. To solve the above-mentioned problems, other superior ports are compared. The port Authority is proposed. It takes part in the long term port planning and the planning of financial provision. It designates and supervises the port manager, measures the result of port management and arranges the proposals. The port ownership transfer from Ministry of Maritime Affairs and Fisheries to Pusan Metropolitan. The port management is to be taken by the port authority and the port operation is to be performed by private companies. As a result, it is expected that port productivity increases and marketing power strengthens.

• Magazine of the Korean Society of Agricultural Engineers
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• v.14 no.3
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• pp.2677-2684
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• 1972

This study was carried out to search for an effect on strengths of a pozzolan and a high-early strength cements due to accelerating the initial setting and a rate of strength development at early age, and to obtain the effects applicable for structural construction works safety in the cold winter weather. The results of the study were as follows: 1. The early strength of high-early strength cement was higher than an ordinary portland cement(Type I). 2. High-early strength cement had a characteristic suitable for construction works in the cold weather due to the rate of acceleration of the eary strength. 3. When using pozzolan cements, a weight proportion should be considered in mix design since the pozzolan cement has a lower specific gravity than other portland cements. 4. It was desirable for the pozzolan cement to shorten the storage period since particles of the pozzolan cement was so fine that it was likely to weathering.

• Journal of Elementary Mathematics Education in Korea
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• v.14 no.3
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• pp.843-863
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• 2010

The basic purpose of 2007 revision curriculum is content of activity oriented, management of differentiated instruction, communication, introduction of story mathematics, mathematical exploration and problem solving ability and so on. In this paper, we investigate some characteristics of number teaching in the primary school of New Zealand. Especially, focused on materials and methods and so on. So we've got the following results. First, there are no fundamental differences in materials and methods in teaching number between Korea and New Zealand but in New Zealand there are no national textbook like us so there is a possibility not to teach number systematically like our Korea. On the contrary, they divide number region from one to six level and are offering achievement objects, suggestive learning experiences, sample assessment activities for each level and also they do not guide activities itself in detail like us and so have learners themselves think about the given problems. Second, there is a strategy stage in getting knowledge about number in New Zealand and so children can take advantage of this steps according to the type of problems. Third, it must be developed some materials and idea to reach the learning purpose rousing interest of children.