• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.1
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• pp.200-207
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• 2019

Cement is one of the most commonly used materials in the construction and civil engineering industry. However, emissions of carbon dioxide generated during the production of cement have been linked to climate change and environment pollutants. In order to replace cement, many studies have been actively performed research to utilizing Blast Furnace Slag(BFS), which is a byproduct of the steel industry. This study aims to investigate the physiochemical properties of the BFS powder based grout to determine whether it can be used as an environment-friendly grout material. As a fine powder, BSF can be used instead of cement grout due to its potential hydraulic property. BSF has also been known for its ability to strengthen materials long-term and to densify the internal structure of concrete. In order to investigate the physicochemical properties of the BFS powder based grout as a grout material, in this study assessment tests were performed through a gel-time measurement, uniaxial compressive strength, and chemical resistance tests, and heavy-metal leaching test. Characteristics and advantages of the slag were studied by comparing slag and cement in various methods.

• Korean Journal of Construction Engineering and Management
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• v.11 no.6
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• pp.111-121
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• 2010

As the customer's interest for sidewalk block in the street or apartment complex is increasing, the materials of block which had been a concrete block exclusively are varied to clay paver, native rock and wood etc. Especially, the sales volume of clay paver which is environment-friendly and ergonomic is dramatically increasing every year with two digits growth rate, however, many problems like "Edge Cracking" "Freezing Breakage" "Bending Breakage" "Joint Gap" are happening frequently within a couple of hours after installation due to the durabilities. Because of the characteristics of Ceramic products, clay pavers are very easy to be broken when they are bumped against each other. In addition, they are relatively fragile by a freezing expansion breakage when exposed to water due to hydrophilic property as well as the intensity and absorptance of the products are varied with small difference from the production process such as production equipment and process control. Therefore, it costs a lot of money to repair the breakdown unless production and installation is carried out according to the strict criteria of the quality control. In this study, the symptoms of breakdown frequently happened in clay paver are classified by each type and finally the solution for this problem in the production of brick, installation and criteria of quality control through compressive strength and absorptance test is suggested.

• Journal of Korean Society of Transportation
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• v.25 no.5
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• pp.91-100
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• 2007

This study suggests direct connection service which has advantage of high-speed operation of KTX and access convenience of general train, and Pre-feasibility studies on the direct connection service. And analyze transportation demand change by the method as follows; It is to analyze the demand change of before and after KTX operation by previous transport data of Gyeongbu line, and calculate the coefficient of utilization using triggering demand by opening the 2nd phase of Gyeongbu line (Dongdaegu${\sim}$Busan). Through Pre-feasibility analysis, reduction $70{\sim}100$ minutes of train travel time and total revenue will increase about $100 thousand per day. Also, there will be environment-friendly effects of decreasing $CO_2$ emissions. But, Direct connection service need to highly cost ; Buying and Operation cost of KTX train. Therefore, we will be get more correct result of Pre-feasibility study on direct connection service, if there are concrete on buying the KTX action plans.

• Korean Journal of Ecology and Environment
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• v.44 no.2
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• pp.203-213
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• 2011

Agriculture modern environments can vary due to factors such as land consolidation and ditch enhancement projects. But, these improvements projects can include cover-ing-up of irrigation ditches with concrete, increasing the drop between paddy field and drainage ditches, which might decrease the abundance and diversity of fish fauna around paddy fields. In this study, for the management of agrobiodiversity on fish in paddy fields, we installed a small-scale fishways between paddy fields and drainage ditches, and evaluated the effects on the eco-connection of the paddy fields, ditches and stream. Five fish species were recovered at the drainage ditches. The species exhibited characteristics spawning and growth based on the paddy field. The results indicate that the five fish species could ascend the paddy fields through the small-scale fishways. There are no difference of species numbers at ditches of environment-friendly agriculture paddy fields (A) and good agricultural practices (B) region, but individual numbers were higher at the B region. This result could be interpreted as indicating that ditch diversity was affected by positional properties rather than farming practices because the water flow and connection to adjacent stream of B region were better than A region. After ascertaining the fish species capable of ascending in a pre-survey of the drainage ditches, we set up small-scale fishways at the drop between paddy fields and drainage ditches. Three species of fish (Aphyocypris chinensis, Misgurnus anguillicaudatus, M. mizolepis) arrived at the paddy fields via small-scale fishways. The main movement time was from 18:00~24:00 and 00:00~06:00, indicating a preference for the night time period rather than the day period for migration. Concentrating the operation time from night to dawn seems prudent for effective management of small-scale fishways.

• The Korean Journal of Archival Studies
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• no.51
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• pp.89-132
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• 2017

The presidential records reflect the era of the times, and it has valuable evidence to support the administrative transparency and accountability of government operations. People's interest in the presidential records increased in response to its recent leak. The presidential archives were moved to Sejong in line with its desire to provide public-friendly services. This study will help users access the archives and utilize archiving information. The Ministry of Education introduced the free learning semester, which all middle schools have began conducting since 2016. The free learning semester provides an environment where education can be provided by external organizations. As middle school students are still unfamiliar with archives, the free learning semester provides a good environment for accessing archives and records. Although it serves as an opportunity to publicize archives, existing related studies are insufficient. This study aims to develop the free learning semester program using the presidential archives and records for middle school students during the free learning semester based on the analysis of the domestic and foreign archives education program. This study shows a development of the education program using presidential archives and records through literature research, domestic and foreign case analysis, and expert interview. First, through literature research, this research understood the definition of the free learning semester as well as its types. In addition, this research identified the four types of the free learning semester education program that can be linked to the presidential archives. Second, through website analysis and the information disclosure system, this research investigated domestic and foreign cases of the education program. A total of 46 education programs of institutions were analyzed, focusing on student-led education programs in the foreign archives as well as the education programs of the free learning semester in domestic libraries and archives. Third, based on these results, This study proposed four types of free learning semester education programs using the presidential archives and records, and provided concrete examples.

• Journal of the Korean Institute of Landscape Architecture
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• v.36 no.3
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• pp.9-20
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• 2008

The government is planning to link a small park with the soon to be ready subway line 9 as a part of Seoul's policy, "The standard or plan for making a water-friendly space by water use" (2007). However, the specified concepts and instructions of the small parks need further work. Therefore, the policy is expected to expand to neighboring small parks near the subway station, but these are not supported by research or data which suggests the needs or actual user behavior and utilization of small parks. our country added the specified concept of small parks and theme parks to the classification of urban parks in the Urban Park Act Revision (2005.3.31), but the concept of small parks is not clearly settled in the law in the scopes of its function, scale, promotion nor particularly defined plans for small park projects. This study examines as small park near a subway station. The characteristics of there region and users vary from the characteristics of the station and region. In the "directions for concrete standards under the types of urban parks and green zones" (2007.2) the types of small parks are classified by "regional characteristics" and "user characteristics". Therefore, this study classifies the subject of neighboring small parks near subway stations as the neighborhood and small urban parks according to the Urban Park Act. The study was paralleled with observation and questionnaires on the analysis of the neighborhood and small urban parks. The actual conditions of park utilization and user behavioral characteristics were deducted by observation, while the questionnaire determined actual user utilization, importance and satisfaction level as well as the small park environment. This study largely focused on three aspects: park facility, design of this sentence isn't even complete. The second aspect isn't finished and the third isn't here.