• Journal of the Korean GEO-environmental Society
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• v.18 no.7
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• pp.13-20
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• 2017

Soil nailing is ground reinforcement method using the shear strength of ground and the pullout shear resistance force of nail. It is mainly used for reinforcement of cut slopes, earth retaining structures and retaining walls, etc. It may be designed considering the pullout resistance of nail in the case of earth retaining structure and retaining wall, but it should be designed considering not only pullout resistance but also shear and bending resistance in the case of slope. However, conservative designs considering only pullout resistance are being done and most of the studies are about increasing pullout resistance by improving of material, shape and construction method of nail. Actually, Shear bending deformations occur centering on the active surface in ground reinforced with the nail. The grout with relatively low strength is destroyed and separated from the reinforcing material. As a result, the ground is collapsed while reducing the frictional resistance rapidly. Therefore, it is necessary to develop the method to increase the shear resistance while preventing separation of nail and grout body. In this study, an experimental study was conducted on new soil nailing method which can increase shear resistance by forming protrusions through pressurized grouting after installing a packer on the outside of deformed bar.

• The Transactions of the Korea Information Processing Society
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• v.7 no.1
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• pp.224-234
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• 2000

In this paper, we propose a new CPLD technology mapping algorithm for sequential circuit under time constraints. The algorithm detects feedbacks of sequential circuit, separate each feedback variables into immediate input variable, and represent combinational part into DAG. Also, among the nodes of the DAG, the nodes that the number of outdegree is more than or equal to 2 is not separated, but replicated from the DAG, and reconstructed to fanout-free-tree. To use this construction method is for reason that area is less consumed than the TEMPLA algorithm to implement circuits, and process time is improved rather than TMCPLD within given time constraint. Using time constraint and delay of device the number of partitionable multi-level is defined, the number of OR terms that the initial costs of each nodes is set to and total costs that the costs is set to after merging nodes is calculated, and the nodes that the number of OR terms of CLBs that construct CPLD is excessed is partitioned and is reconstructed as subgraphs. The nodes in the partitioned subgraphs is merged through collapsing, and the collapsed equations is performed by bin packing so that if fit to the number of OR terms in the CLBs of a given device. In the results of experiments to MCNC circuits for logic synthesis benchmark, we can shows that proposed technology mapping algorithm reduces the number of CLBs bu 15.58% rather than the TEMPLA, and reduces process time rather than the TMCPLD.

• Journal of the Korean Institute of Gas
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• v.14 no.4
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• pp.51-55
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• 2010

The global activities to reduce the $CO_2$ emission as a greenhouse gas have been various efforts. Under this circumstance, small and medium sized gas field containing $CO_2$ to develop as LNG is not economic feasibility. Particularly, for the separation of $CO_2$ in gas field, separation facilities should be installed to add. This is and increase in plant construction cost and separated $CO_2$ emission into the atmosphere is not the result of greenhouse gas reduction. When the uneconomic gas field apply the KOGAS DME process, the gas field containing $CO_2$ can be increase economic feasibility because of natural gas and $CO_2$ can be use to resource gas. The Tri-reformer produced syngas as H2 and CO in KOGAS DME process and the resource gases are natural gas, steam, oxygen and $CO_2$. The $CO_2$ is used as raw material gases from recover $CO_2$ in DME process. In this study, we investigated range of application of $CO_2$ in gas field.

• Journal of Korea Water Resources Association
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• v.38 no.8 s.157
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• pp.665-674
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• 2005

The aim of this study is to evaluate 3 types of sedimentation basins: dredging, shield skirt and auxiliary dam, constructed at inlets of two irrigation reservoir and to estimate the most beneficial type and fitted size, SAR(surface to area ratio), for pollutant removal efficiency(RE). For this, RE of major water quality items and change of physicochemical properties in sediments before and post construction of sedimentation basin(SB) were investigated. RE depended on SB types, water quality items and survey times with wide range from $-87\%$ to $92\%$. Long term overall removal efficiency by ROC(regression of concentration) method were $18\%$ in dredging, $29\%$ in shield skirt and $42\%$ in auxiliary dam type. There was a change of physicochemical properties in sediments at auxiliary dam type, while a slight change at dredging and shield skirt type. In comparison to RE, SAR and hydraulic retention time at 3 types of SB, auxiliary dam type was the most beneficial one. Thus, it is recommended that SB would be constructed in completely separated structure from water body of a reservoir with SAR ranged from 0.7 to $1.0\%.$

• Journal of the Korea Organic Resources Recycling Association
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• v.19 no.2
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• pp.55-69
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• 2011

Use of disposer at the kitchens of Korean apartments is inevitable in treating their foodwaste having a water content of more than 80%. Also we have to ensure that this extra disposer-foodwaste BOD loadings be treated properly by installing/operating a pre-treatment system before this wastewater enters public sewer system. However, the degree of BOD removal should not be excessive since a BOD/N ratio higher than 5 is required for removing N/P at a municipal wastewater treatment plant. The removal of BOD/N in the pretreatment system rather than BOD alone can be an alternative solution in solving this problem. The particles separated by sedimentation, screen or packed-bed can be anaerobically digested at apartment sites to generate biogas that can be used for simple digester heating and to generate volatile fatty acids (VFAs) for nitrogen removal. We suggest that Korean government grants a temporary license (say for 5 years) to foodwaste treatment companies in collaboration with apartment construction companies which may do business and develop various kinds of disposer-foodwaste treatment systems in diverse wastewater discharge systems of Korean apartments.

• (The)Korea Educational Review
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• v.22 no.3
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• pp.169-192
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• 2016

The purpose of this study is to investigate the relations between religious socialism and education of Martin Buber(1878~1965), a theistic existentialist. Buber suggested religious socialism as an alternative to modern capitalist society which has many problems. Buber's religious socialism is based on the communitarianism of Hasidism. Buber considered 'true' socialism must be based on decentralized associations, not based on centralized state apparatuses. For establishing this kind of socialism, human will and mind are the most important. Thus, education takes a very important role in the process of social transformation. According to Buber, education and pedagogy should contribute to overcoming modern society's problems by pursuing the construction of community(true socialist society). For Buber, education for individuals' character and education for building community are not separated but combined. That is, although education takes a main role in the social transformation, it should not be considered just as an instrument for the social transformation. This is the main distinction between Buber's thought and other key socialists' thoughts on social transformation and education, because many of socialists who stress the role of education in the process of social transformation, tend to regard education as an instrument for the social transformation. According to Buber, education can contribute to social transformation without being an instrument for the social transformation. These ideas of Buber on religious socialism and education have important implications for educators and educationalists who hope education contributes to solving problems of modern society.

• 한국사회정책
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• v.23 no.2
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• pp.113-139
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• 2016

This article tries to compare exchange relations between welfare and dictatorship in the East Germany and the North Korea. Unlike capitalist welfare aiming at correcting market results socialist welfare has been proposed to satisfy people's basic needs, but it had operated as instrument of dictatorship. Relation between welfare and dictatorship could be distinguished as hard exchange and soft one in line with social construction of welfare. Welfare-dictatorship relation in East Germany had developed from its formation(1949-1970s), crisis(1980s) and dissolution(1989-1990). There had established hard exchange relation in which the legitimacy of dominance had debted to welfare as social rights. While crisis of the exchange relation had been modest in a form of insufficient supply of consumption goods, it was one of the elements of collapse of dictatorship, leading to the unification with West Germany. The journey of the exchange relation in North Korea can be characterized by its formation(1948-1980), crisis(1990s-2000s), and transformation(2010s). Unlike East Germany, welfare was socially constructed as gift form the ruler to the ruled, which made the combination of welfare and dictatorship loosely coupled. Although economic crisis was severe compared to East German one the rulers have succeeded maintaining dictatorial dominance by creating dual exchange relation. They separated core group and subordinated one supporting the former at the expense of the latter. They blocked out most of the people from soft exchange relation making bad use of muddling-through life style dependent on market activities. This strategy led to a 'dictatorship neutral welfare extinction'. Taking the high degree of institutionalization of newly establishing welfare-dictatorship relation into account, lives of most people are hardly expected to be improved by gift by their rulers even if North Korean economy will recover in the future.

• The Journal of the Korea Contents Association
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• v.22 no.6
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• pp.92-103
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• 2022

This study was designed to explore the ways to improve the organization and implementation of the curriculum for the small rural middle schools. In order to do this, the situations and demands in organizing and operating the curriculum were analyzed through interviews and classroom observations. Having separated the country into 5 distinct regions and the cases of 10 small rural middle schools across these regions of the country were directly observed and analyzed. As a result of the study, it was necessary to prepare a fundamental solution to the following problems: 1) insufficient linkage between school levels of integrated operating schools in terms of curriculum, 2) lack of educational facilities and cultural space in rural areas in terms of local communities, and 3) supply and demand of teachers in small-scale middle schools in rural areas in terms of supply and demand of teachers. Based on the discussed issues, the following implications could be drawn for the improvement and support of school curriculum organization and implementation. Firstly, the autonomy in organizing and operating curriculums for small rural middle schools should be greatly expanded so that integrated schools or joint curriculums between schools can be operated in a robust manner. Secondly, it needs to strengthen the out-of-school support for small rural middle schools alongside local governments and local communities, including the operation of Edu buses and the construction of multipurpose educational and cultural centers. Finally, it is necessary to address the difficulties of operating circuit teachers by systematically expanding the pool of teachers and instructors, and managing teachers and instructors at the level of the local education office.

• The Journal of the Korea Contents Association
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• v.22 no.2
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• pp.147-161
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• 2022

This study examined changes in the ecological characteristics and design characteristics of Ban's exhibition space in three representative temporary exhibition halls and three permanent exhibition halls designed by Ban Shigeru since 2000. Through the investigation of the concepts and characteristics of ecological architecture, the design characteristics of exhibition space, the analysis framework of the design characteristics of exhibition space and the design elements of ecological architecture is obtained. The analysis results show that there are big changes between the temporary exhibition space and the permanent exhibition space in terms of building scale, space composition, function, materials and technology. On the one hand, the temporary exhibition space used recyclable materials, such as paper tubes, containers to be assembled on site into a single-layer space focused on display. The assembly method was simple and the construction period was short. After the exhibition, the exhibition space were dismantled. The materials were either transported to the next display site or recycled and reused. On the other hand, the permanent exhibition space used reinforced concrete as the main structure, and used a large amount of wood and glass materials to construct a multi-layered composite cultural space that separated the exhibition space and the leisure space. In terms of ecological characteristics, the building materials of the temporary exhibition space were recycled and no industrial wastes were generated after the demolition. The permanent exhibition hall uses eco-friendly wood for the roof and walls, so it is easy to replace and repair. Both types of exhibition halls are changing ecological architecture in a more sustainable direction by saving resources and energy through natural light and ventilation.

• Korean Journal of Materials Research
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• v.34 no.6
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• pp.291-302
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• 2024

In this paper, iron ore tailings (IOT) were separated from the tailings field and used to prepare cement stabilized macadam (CSM) with porous basalt aggregate. First, the basic properties of the raw materials were studied. Porous basalt was replaced by IOT at ratios of 0, 20 %, 40 %, 60 %, 80 %, and 100 % as fine aggregate to prepare CSM, and the effects of different cement dosage (4 %, 5 %, 6 %) on CSM performance were also investigated. CSM's durability and mechanical performance with ages of 7 d, 28 d, and 90 d were studied with the unconfined compression strength test, splitting tensile strength test, compressive modulus test and freeze-thaw test, respectively. The changes in Ca²⁺ content in CSM of different ages and different IOT ratios were analyzed by the ethylene diamine tetraacetic acid (EDTA) titration method, and the micro-morphology of CSM with different ages and different IOT replaced ratio were observed by scanning electron microscopy (SEM). It was found that with the same cement dosage, the strengths of the IOT-replaced CSM were weaker than that of the porous basalt aggregate at early stage, and the strength was highest at the replaced ratio of 60 %. With a cement dosage of 4 %, the unconfined compressive strength of CSM without IOT was increased by 6.78 % at ages from 28 d to 90 d, while the splitting tensile strength increased by 7.89 %. However, once the IOT replaced ratio reached 100 %, the values increased by about 76.24 % and 17.78 %, which was better than 0 % IOT. The CSM-IOT performed better than the porous basalt CSM at 90 d age. This means IOT can replace porous basalt fine aggregate as a pavement base.