• Journal of the Korean Recycled Construction Resources Institute
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• 제7권1호
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• pp.22-28
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• 2019

Cement is a basic material for the construction industry and it requires high temperature sintering when manufacturing cement. $CO_2$ emissions from raw materials and fuels are recognized as new environmental problems and efforts are underway to reduce them. Techniques for reducing $CO_2$ in concrete are also recommended to use blended cement such as blast furnace slag or fly ash. In addition, the construction waste generated in the dismantling of concrete structures is recognized as another environmental problem. Thus, various methods are being implemented to increase the recycling rate. The purpose of this study is to utilize the inorganic raw materials generated during the dismantling of the structure as a raw material for the low carbon type cement binder. Such as, waste concrete powder, waste cement block, waste clay brick and waste textile as raw materials for low carbon type cement binder. From the research results, low carbon type cement binder was manufactured from the raw material composition of waste concrete powder, waste cement block, waste clay brick and waste textile.

• Environmental and Resource Economics Review
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• 제28권1호
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• pp.147-176
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• 2019

This paper uses research on the Levelized Cost of Electricity (LCOE) in South Korea to conduct a simulation analysis on the impact of nuclear power dependency and usage rates on the social costs of power generation. We compare the $7^{th}$ basic plan for long-term electricity supply and demand, which was designed to increase nuclear power generation, to the $8^{th}$ basic plan for long-term electricity supply and demand that decreased nuclear power generation and increased renewable energy generation in order to estimate changes in social costs and electricity rates according to the power generation mix. Our environmental generation mix simulation results indicate that social costs may increase by 22% within 10 years while direct generation cost and electricity rates based on generation and other production costs may increase by as much as 22% and 18%, respectively. Thus we confirm that the power generation mix from the $8^{th}$ basic plan for long-term electricity supply and demand compared to the $7^{th}$ plan increases social costs of generation, which include environmental external costs.

• Journal of Korean Society of Coastal and Ocean Engineers
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• 제31권2호
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• pp.62-72
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• 2019

Due to the difficulties in forecasting the intensity and the source location of tsunami the countermeasures prepared based on the deterministic approach fail to work properly. Thus, there is an increasing demand of the tsunami hazard analyses that consider the uncertainties of tsunami behavior in probabilistic approach. In this paper a fundamental study is conducted to perform the probabilistic tsunami hazard analysis (PTHA) for the tsunamis that caused the disaster to the east coast of Korea. A logic tree approach is employed to consider the uncertainties of the initial free surface displacement and the tsunami height distribution along the coast. The branches of the logic tree are constructed by reflecting characteristics of tsunamis that have attacked the east coast of Korea. The computational time is nonlinearly increasing if the number of branches increases in the process of extracting the fractile curves. Thus, an improved method valid even for the case of a huge number of branches is proposed to save the computational time. The performance of the discrete weight distribution method proposed first in this study is compared with those of the conventional sorting method and the Monte Carlo method. The present method is comparable to the conventional methods in its accuracy, and is efficient in the sense of computational time when compared with the conventional sorting method. The Monte Carlo method, however, is more efficient than the other two methods if the number of branches and the number of fault segments increase significantly.

• The Journal of the Acoustical Society of Korea
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• 제38권1호
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• pp.56-65
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• 2019

The Indo-Pacific bottlenose dolphins (Tursiops aduncus) are a toothed whale using echolocation clicks and have been studied continuously abroad. However, most studies on this whale's clicks were performed about captive animals and, in Korea, only the studies of the whistle sounds of this animal were done. In this paper, acoustic characteristics of clicks were analyzed about the free-ranging Indo-Pacific bottlenose dolphins living in the coast of the Jeju Island. Acoustic parameters such as signal duration, 1st and 2nd peak frequency, 3 dB and 10 dB bandwidth for acoustic characteristics were calculated and compared with those of Australian species. As a result, the signal durations had average of $38{\mu}s$ and most clicks were within range of $20{\mu}s-60{\mu}s$. The two types of bandwidths showed both narrowband and broadband characteristics, and bimodal signal characteristics were confirmed through the 1st peak frequencies(average of $96kHz{\pm}18kHz$) and the 2nd peak frequencies(average of $69kHz{\pm}19kHz$).

• Journal of the Korea Academia-Industrial cooperation Society
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• 제20권6호
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• pp.483-488
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• 2019

This study first examines whether the high matching principle reduces the cost of equity, and then examines the effect on discretionary accruals and capital cost. According to previous studies, the higher the response to revenue cost, the higher the earnings quality. The higher the quality of earnings, the lower the information risk, and the lower the information risk, the lower the capital cost of enterprise. Discretionary accruals can play two roles in opposing each other. One is that managers use the discretionary accruals to provide private information about the future of the corporation to the market, thus enhancing the usefulness of the earnings. The other is that managers can use the discretionary accruals opportunistically to distort earnings and provide misinformed information to investors, thus reducing the usefulness of earnings. The results of this study represents that the higher the responding to the revenue cost, the less the cost of equity. In the case of firms with high revenue response, we examine whether discretionary accruals reduce the cost of equity capital. As a result of the study, the higher the responding to the revenue cost, the lower the cost of equity capital. Companies with higher matching principle have been shown to reduce their capital costs by using discretionary accruals.

• Journal of the Korea Academia-Industrial cooperation Society
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• 제20권7호
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• pp.255-264
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• 2019

This study aimed to examine the moderating effects of emotional support and facilitative relationship in the relation of emotional abuse and difficulties in emotion regulation. This research suggests therapeutic methods for reducing the negative effects of emotional abuse. Data about emotional abuse, difficulties in emotion regulation, emotional support, and relationship inventory were collected by online survey from 336 adults in South Korea. To test moderation effects, multiple regression analyses entering emotional abuse, emotional support(facilitative relationship) and their interaction terms were hierarchically conducted. Emotional abuse increased difficulties in emotion regulation. Moderating effects of emotional support and facilitative relationship were found in the relation between father's emotional abuse and difficulties in emotion regulation. But Moderating effects of emotional support and facilitative relationship were not found in the relation between mother's emotional abuse and difficulties in emotion regulation. The different effects of father's emotional abuse and mother's, the effects of adult's positive relationship, and clinical implications of these findings were discussed.

• Plant Journal
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• 제14권4호
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• pp.39-47
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• 2018

In this research, when the output of the standard coal-fired thermal power plant operating continuously at the rated output of 500 MW is changed to operate at 300 to 500 MW, the amount of sulfur oxide produced and the amount of sulfur oxide in the absorption tower of desulfurization equipment and proposed an extra liquid to gas ratio improvement inversely proportional to the output. In order to calibrate the combustion efficiency at low power, the ratio of sulfur oxides relative to the amount of combustion gas is increased as the excess air ratio is increased. When the concentration of sulfur oxide at the inlet of the desulfurization absorber was changed from 300 to 500 ppm along with the output fluctuation. The liquid to gas ratio of limestone slurry and combustion gas was changed from 10.99 to 16.27. Therefore, if the concentration of sulfur oxides with output of 300 MW is x, The following correlation equation is recommended for the minimum required flow rate of slurry for the reduction of surplus energy due to the increase of the liquid weight at low load. $y1[m^3/sec]=0.11x+3.74$

• Journal of the Korean Institute of Traditional Landscape Architecture
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• 제36권4호
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• pp.105-112
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• 2018

This study aims to apply 3D scanning technology to the field of landscape planning design. Through this, 3D scans were conducted on Soswaewon Garden and Seongrakwon Gardens to find directions for traditional landscape planning and designs. The results as follows. First, the actual measurement of the traditional garden through a 3D scan confirmed that a precise three-dimensional modeling of ${\pm}3-5mm$ error was constructed through the merging of coordinate values based on point data acquired at each observation point and postprocessing. Second, as a result of the 3D survey, the Soswaewon Garden obtained survey data on Jewoldang House, Gwangpunggak Pavilion, the surrounding wall, stone axis, and Aeyangdan wall, while the Seongnakwon Garden obtained survey data on the topography, rocks and waterways around the Yeongbyeokji pond area. The above data have the advantage of being able to monitor the changing appearance of the garden. Third, spatial information developed through 3D scans could be developed with a three-dimensional drawing preparation and inspection tool that included precise real-world data, and this process ensured the economic feasibility of time and manpower in the actual survey and investigation of landscaping space. In addition, modelling with a three-dimensional 1:1 scale is expected to be highly efficient in that reliable spatial data can be maintained and reprocessed to a specific size depending on the size of the design. In addition, from a long-term perspective, the deployment of 3D scan data is easy to predict and simulate changes in traditional landscaping space over time.

• Journal of Internet Computing and Services
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• 제19권6호
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• pp.9-20
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• 2018

Financial service industry has introduced and operated management systems such as information security management system (ISMS), personal information security management system, business continuity management system to protect and maintain suitably customer's financial information and financial service. This study started that it's desirable financial industry takes consideration of ISMS and it can be different types among various organizations taking consideration of culture, practical work, and guideline of information security. The study derives primary control areas of ISMS through analyzing non-conformity trends and control factors according to certification audit for finance-related organizations introduced international ISMS of ISO27001 which is well known and commonly applicable irrespective of areas in financial service industry. Through case analyses for five finance-related organizations operating ISMS, this study analyzed improvement effects of ISMS. It has a meaning as an initial research though it was difficulty in acquiring data for empirical study because of rare organizations maintaining certification in financial sector. As a result, number of non-confirmity from the first audit to three years' elapse was decreased every year. Physical and environmental security, communication and operations management, and access control having the highest frequency of non-conformity each presented 23%, 19%, and 17%, which reached 59% in total and they are derived into primary control areas. ISMS can fulfill technical, managerial, physical security issues, which have not been treated importantly in financial industry. In addition, this study presented that ISMS can be an effective management system applicable for financial service industry.

• Korean Journal of Construction Engineering and Management
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• 제22권5호
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• pp.29-38
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• 2021

Governments and companies are trying to reduce occupational accidents in the construction industry; however, the number of disasters are not decreasing significantly. This study aims to identify the correlation between factors affecting construction disasters quantitatively. To this end, 1,197 cases of serious disasters provided by Korea Occupational Safety and Health Administration (KOSHA) were analyzed using affinity analysis, one of the data mining techniques. The data from KOSHA were preprocessed and analyzed with variables of accident type, project type, activity type, original cause materials, sensory temperature, time of the accident, and fall height, and the association rules were derived for fall accidents and the others. For fall accidents, 64 association rules with lift ratios of 1.38 or greater were derived, and for the other accidents, 59 association rules with lift ratios of 1.54 or greater were derived. After analyzing the derived association rules focusing on the relationship among accident factors, this study presented the significance of applying the affinity analysis to address the study's limitations. The significance of this study can be found in that the correlation among factors affecting construction accidents is presented quantitatively.