• Journal of the Korea institute for structural maintenance and inspection
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• v.28 no.1
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• pp.24-31
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• 2024

Mortar has been applied in most previous studies on 3D concrete printing. In such cases, however, the economic efficient cannot help decreasing due to higher binder contents and larger amount of fine aggregates. In order to enhance the applicability of 3D printing technology to construction industry, therefore, 3D concrete printing technology utilizing coarse aggregates needs to be developed further. This study aims at proposing the mix design process of concrete containing coarse aggregates for 3D printing. Based on extensive literature review and experimental studies, the mix proportion suitable for 3D printing has been derived, and the extrudability of concrete with coarse aggregates has been verified through 3D printing tests. The primary variable of the extrudability tests was the contents of viscosity modifying agent (VMA), and the extrudability was quantitatively evaluated by measuring dimensions, distribution of aggregates, and surface quality of 3D-printed filaments. The test results showed that the dimensional suitability and surface quality were improved as the VMA contents were larger, and the coarse aggregates were evenly distributed in the section of filament regardless of the VMA contents. Based on the test results, the mix design process for concrete containing coarse aggregates for 3D printing has been proposed.

• Journal of the Korean Institute of Landscape Architecture
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• v.44 no.2
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• pp.11-24
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• 2016

This study, which takes the New York Governors Island project as an example, is an in-depth analysis of the process of participatory design for transforming a space that had long been isolated from the public into a park and/or communal space. We found that the process of participatory design at each project phase consists of the following. First, in the preparatory phase, there was construction of public discourse: efforts to find a consensus to develop the space in a public-driven direction was led by various initiatives. Second, by opening the site to the public before the design phase and by consistently inviting a wide range of activities, a community was formed and its attachment to the site was established. Third, after the competition until the completion of the project master planning phase, substantial and active participatory design was enabled through social interaction of the community formed and developed over many years. Fourth, in the detail design and implementation phase, a traditional and passive way of participatory design such as public hearings was used, thereby preserving the expertise of professional designers. Public participation was reflected most in the master planning phase to create a broad framework of the park, while professionals designed the more specific aspects; this efficient and effective approach enabled both citizens and professionals to dutifully take part in developing the park. The results of this study can be summarized as follows. The mode of participatory design should be varied at each project phase, from construction of public discourse, to formation and development of the community, to participatory design for social interaction. Furthermore, it is effective to preserve the unique roles of citizens and design professionals. It is particularly important to extend the process of participatory design to include the construction of public discourse and community.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.23 no.3
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• pp.229-242
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• 2013

Objectives: This study was designed to investigate the current status of the association of job-related information such as employment status, workplace environment, and hazard material exposures with health examination outcomes. Methods: The study used data from KNHANES 2007-2009 representing the three years of 2007-2009, which was conducted annually using a rolling sampling design that involved a complex, stratified, multistage, probability-cluster survey of a representative sample of the non-institutionalized civilian population in Korea. The final analytical sample consisted of 17,240 participants. Information on age, education, smoking history and alcohol intake was collected during the health interview. Job related information consisted of employment status, workplace environment, and hazardous material exposure. The selected indices of health examination were blood pressure, fasting glucose, blood cholesterol, HDL, SGOT, SGPT, and BUN. Results: In multiple logistic regression analysis using hypertension and pre-hypertension as dependent variables and job related categories as independent variables after covariate adjustments, the odds of hypertension and pre-hypertension were significantly lower in those with responsibility and power in their job activities. Interestingly, low odds for hypertension were observed among those who reported that their jobs were fast-paced. Conclusions: This study confirmed that some job-related categories in employment status, workplace environment, and hazardous material exposure had an association with health outcome status. It is worthwhile to comment that high responsibility and power in job activities were revealed as one of the important favorable factors to improve health condition of workers.

• Journal of the Korean Association of Geographic Information Studies
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• v.8 no.2
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• pp.55-67
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• 2005

This study presented the route location method by applying AHP and evaluating quantitatively. This study developed the program that can be easily applied to this kind of road design, and built the decision support system for route location. The study results are summarized as follows ; We could quantitatively evaluate the appropriateness of exiting routes by applying the AHP based on GIS. If we apply this to the roads that will be newly constructed, we can make the objective and reliable route location when making road plans and basic designs. We improved the technique of route location by applying the decision support system with third-dimensional data, which considers even the vertical alignment plan, to the existing decision support system with second-dimensional data. And, since we can set those data such as vertical slope, earth-volume, structure size, location and construction cost to independent variables, we can make road designs more scientifically and reasonably.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.6 no.6
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• pp.56-71
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• 2003

Waste landfills have been the center of environmental problems and they must be restored due to environmental pollution, disgusting landscape, and cost of management. It is suggested that they be recycled urban space as cities expand. Specially, nonsanitary waste landfills which have no pollution prevention facilities cause serious problems. Restoring the landfills as parks and golf courses, so on makes more benefits because of cheap use land, closeness to urban area, flat topography applicable to parks and golf courses, and high land values after restoration and the changes to local recreation sites. Restoration of waste landfills is a complex, costly, and interdisciplinary work. But, the waste landfill is a manmade ecosystem. Control, restoration and postmanagement of waste landfills are very important problems. The role of vegetation prevents soil erosion, reduces soil water storage, and obstructs leachate seepage. Early restoration makes derelict lands into man park artificially geared to soil, vegetation, landforms and hydrology. But, Ideal restoration is to make stable ecosystem nature-friendly and compatible with surrounding landscape without more management. Landscape is structured hierarchically with patches and stands as small components and forms forest as large components. Therefore, landscape formation of the waste landfills needs much restoration process. There are many ecological restoration techniques for the waste landfills. Those are divided into artificial and natural methods. The artificial method is anthropogenic plantings while the natural method is to trigger and use succession processes. The most important thing in the restoration of waste landfills is to consider the final restoration objectives of each waste landfill. According to these objectives, the depth of covering layer, planting degree, and structural design should be determined. The effective restoration methods should be selected of artificial and natural options.

• Journal of Wetlands Research
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• v.6 no.2
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• pp.57-63
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• 2004

More than 1000 natural and constructed wetlands have been used to improve water quality. The general results showed that the highest removal efficiency was 84% for BOD and the lowest one was 48% for total nitrogen concentration. In addition, total phosphous removal efficiency was 67%, and the removal efficiencies are related to inflow loading. Researches donducted in Korea have focused on input-output mass balance and uptake by aquatic plant. As such little information if available about complex processes regulating water quality and role of microbes. Therefore, to determine the optimal design for construct, and methods to operate constructed wetland, researches about complex mechanisms of contaminant removal and interdisciplinary researches are necessary.

• Korean Journal of Cognitive Science
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• v.17 no.4
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• pp.375-398
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• 2006

Humans learn by observing, hearing, imitating, doing, and feeling. The brain(cortex) is the central tore of this process. The recent rapid progress of brain science and the active interdisciplinary collaboration between brain science and cognitive science opens a new possibility. That is a new research Held called 'Brain-Based learning Science', 'Edutational Neuroscienre', or 'NeuroEduration' This study reviews the nature and basic assumptions of brain-based learning science, current directions in educational neuroscience research, the neuro-myths, educational implications of neuroscience, and a possibility of making a meaningful connection between brain science and education. Also the future prospects and limitations of the brain-based learning science are discussed.

• Journal of Distribution Science
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• v.15 no.7
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• pp.53-59
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• 2017

Purpose - In the airline industry, an airport plays an important role. There are a lot of employees who work at an airport, and most of the workers experience restraints regarding leisure activities. Thus, there is a need for studying the internal marketing in the airport to better serve the worker. Although there is a lack of well-structured research regarding the restrictions and satisfaction factors experienced by the airport employees for their leisure activities, this research studies how the restrictions and satisfaction factors influence each other in relation to the internal marketing in the airport. The purpose of this research is to provide a detailed, real time research method for studying the restrictions and satisfaction factors in relation to the internal marketing that are experienced by the airport employees regarding their leisure activities. Research design, data, and methodology - This survey was conducted for airport employees working in two shifts. The questionnaire is 152 copies. The analysis method was used as SPSS statistical package 21.0 and Netminer 4.0 program. Social networks were analyzed for leisure satisfaction and leisure restrictions. Results - As a result of analyzing the linkage between variables for leisure satisfaction, most of the variables of leisure satisfaction are satisfied with "psychological factor" and "social factor". However, "educational factor" and "environmental factor" are not satisfied. In order to improve the leisure satisfaction of airport workers in the future, it is necessary to have an environment where leisure activities can be performed and related education. As a result of analyzing the linkage between variables of leisure restrictions, most of the variables in leisure restrictions are "personal factors" and "temporal factors". However, there are few restrictions on "cost-efficient" and "environment-friendly". Conclusions - In the future, in order to reduce the leisure restrictions of airport workers, they need to reduce work stress, psychological time and leisure allowance for leisure activities. However, it is difficult to solve these problems due to realistic problems including the specificity of working at the airport. This research presents an interdisciplinary analysis of how the restrictions and satisfaction factors influence each other in order to further advance the understanding of the constraints and satisfaction that are experienced by the airport employees.

• The Journal of the Korea Contents Association
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• v.17 no.1
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• pp.611-633
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• 2017

This research was designed to verify the causal relationships between organization managers' unmet expectations and job burnout and the mediating effects of overcommitment based on the effort-rewards imbalance theory. It was also intended to evaluate the moderating effect of LMXSC on the relationship between overcommitment and job burnout. 172 branch managers working at commercial bank were selected as the target research group. This study was validated by The SPSS 24.0, the reliability was justified through the factor analysis, and the casual relationship was confirmed through the three-step regression. As a result, unmet expectations had a strong positive correlation with job burnout and overcommitment. Overcommitment had a strong positive correlation with the mediating effect between unmet expectations and job burnout. Moderating effects of LMXSC were not significant. This study showed the practical implication between unmet expectations, overcommitment, and job burnout. Additionally it exhibited the job design and management practice in manager groups where the importance of their role has been expanded. Lastly, we found the interdisciplinary implication from making an effort to elaborate the antecedent of variables.

• Journal of Advanced Navigation Technology
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• v.12 no.2
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• pp.122-131
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• 2008

In this paper, an S-band oscillator of the low phase noise property using miniaturized microstrip hairpin shaped ring resonator has been designed and implemented. The TACONIC's RF-35 substrate has a dielectric constant ${\varepsilon}_r$=3.5 a thickness h=20mil a copper thickness t=17 um and loss tangent $tan{\delta}$=0.0025. The designed and implemented 2.45 GHz oscillator shows low phase performance of -100.5 dBc/Hz a 100kHz offset. Output power 20.9 dBm at center frequency 2.45 GHz and harmonic suppression -32 dBc. The circuit was implemented with hybrid technique. But can be fully compatible with the RFIC's, MIC and MMIC due to its entirely planar structure.