• Journal of the Architectural Institute of Korea Planning & Design
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• v.34 no.7
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• pp.21-29
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• 2018

This study aimed to find and suggest the purpose of future plans, critical items on designing and Related standards to amend construction standards for domestic energy saving and environmentally friendly housings. It would also activate and increase the supplies of passive house minimizing the problems on current apartment housings in winter and reducing heating energy which brings fine dust pollution. After defining the standard model of Korean apartment housings(reference model), this study calculated the amount of heating energy demand per unit area annually as applying the yearly changed standards from 2008 to 2017 to existing standard model. It turned out that applying 2017 construction standards of energy saving and eco-friendly housings to reference model has saved up to 75% of heating energy demand comparing to the one applied 2008's. However, it still could not solve the fundamental problems such as winter fungus, condensation, freezing, freeze and burst, and insulation weakness space, and could not be free from fine dust particles. To solve them, this study suggested improved standards adding critical items on design related to outside insulation, cut off the heat-bridge, enforce air-tightness and heat change efficiency on heat recovery ventilator. As a result, it has reduced more than 10% of heat demand from 2017. It would be more than 90% of savings from 2008 if we make the amount of heat loss be zero on heat bridge on designing stage in the future.

• Journal of the Architectural Institute of Korea Planning & Design
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• v.35 no.11
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• pp.13-24
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• 2019

The history of tall buildings begins in 1853with the development of elevators. After the Industrial Revolution of the 18th century, the development of high-rise buildings will be carried out in earnest as a means to efficiently use the limited land of cities. The development, which began around Chicago, extended over a long period of time to Asia, maximizing the high competition. However, in the 2000s, not only was it high due to the development of construction and digital technology, but it also became competitive in eco-friendly elements and unstructured forms. High-rise building plans that have gained elemental and morphological diversity are completed by the interrelationships of various plans. Among them, it is important that the core plan has a reasonable approach from the initial planning stage as the basis for the vertical copper plan linking vertically-intensive functions. The cores should be designed to be clear and adequately responsive to changes in the shape of the building. This study aims to provide designers with a reasonable understanding of core planning by identifying core characteristics of irregular high-rise. In particular, we want to analyze the shape of the ground layer core and the relationship between the area and components of the ground layer core. The analysis results are as follows, classified according to the type or use of the building. Of the atypical forms composed of double bending, the TAPER-Curve and TWIST forms are the most distributed, and the plane and core shapes of the ground floor are the most commonly used. Based on the analysis of the validity of the ground floor cores by shape of the cores, the most commonly used forms for core shapes in the planning of the atypical high-rise are square, circular and Oval, and the most efficient oval cores and relatively inefficient ones when planned.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.8
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• pp.1015-1021
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• 2020

Mobile news users want news articles without advertising, meanwhile the news providers require advertisement displays in several types to attain advertising revenue. In this paper, we classified the types of advertisements on mobile news articles into fixed article type which is fixed on some areas of articles, fixed screen type which is fixed on mobile screens, and a combination type of them. In addition, we proposed a smart solution based on overlapping method which effectively organize advertisements to not distract the readers. The proposed method is similar to fixed article type and overlapping technique of advertisements on news article's photo or virtual area. The performance evaluation result shows that the proposed method provides more spaces for news articles effectively than the existing methods. Although only some areas of advertisements may be blocked according to the number or size of advertisements, the effect is not critical.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.19 no.10
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• pp.98-104
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• 2020

Recently, friction stir welding of dissimilar materials has become one of the biggest issues in lightweight and eco-friendly bonding technology. In this study, a lightweight torsion beam axle, which is an automobile chassis component, was used in the welding to cast aluminum material. The friction stir welding process of A357 cast aluminum and FB590 high-strength steel as well as the effects of the process parameters were investigated and optimized using a novel definitive screening design (DSD). ANOVA was used to predict the importance of the process parameters with 13 degradation experiments using the proposed DSD. Also, FSWed experiments were conducted using an optical microscope analysis to investigate the tensile strength behavior in the weld area. In addition to determining the interaction between the tool's rotational speed and the plunge speed, results indicate that the influence of the plunge depth was the most significant.

• Korean Journal of Construction Engineering and Management
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• v.22 no.1
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• pp.90-97
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• 2021

Saemangeum Development is the largest national project in South Korea, which has been developed for an agricultural, economic and tourist area for 30 years from 1987. In order to convert power sources that used to depend on nuclear and thermal power to eco-friendly for carbon reduction, the government plans to construct a 2.1GW floating photovoltaic project by investing 4.6 trillion won, as a public-private project. For success of the Saemangeum floating photovoltaic project, economic feasibility should be checked. This study defined the factors (construction cost, electricity selling price, power generation and maintenance cost) that give a effect to the volatility of the floating photovoltaic payoffs, and analyzed the volatility of payoffs during 20 years operation period. NPV and option value of the project were calculated by applying an option to abandon. According to NPV analysis, it is determined that projects are difficult to invest. But this project has economic feasibility through real options analysis. This study is expected to help decision-makers in the economic analysis of floating photovoltaic projects by using the real options analysis.

• Journal of Korean Society of Forest Science
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• v.100 no.3
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• pp.504-521
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• 2011

This study was carried out phytosociological forest community analysis, the sampled dada were collected and studied by 1,456 plots from 1993 to 2009 for 17 years in the 22 mountain area of South Korea. Four opposed species groups were classified and 10 vegetation units were divided as a result of forest vegetation classification. The 10 units were closely correlated with major environmental factors such as geological features, climatic conditions, topographical configurations, and etc. Therefore the forest vegetation of South Korea could be conclusively abstracted by 10 vegetation units and 7 eco-types.

• Journal of Korean Society on Water Environment
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• v.37 no.3
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• pp.175-189
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• 2021

In this study, 48 streams in the Sapgyo Watershed were selected, and the Load Duration Curves (LDC) were drawn up for each stream using water quality and flow monitoring over the last three years (2018-2020), and it was evaluated whether the target water quality was achieved for each flow section. As a result of evaluating whether or not the target water quality exceeded according to the LDC, it was found that 22 rivers exceeded the target water quality. Five rivers exceeded the target water quality due to point pollutant sources, 13 rivers exceeded the target water quality due to non-point pollutant sources, and 4 rivers exceeded the target water quality due to both point and non-point pollutant sources. Among the rivers that exceeded the target water quality due to point pollutant sources, which included domestic sewage of the untreated population, there is a need to reduce the influx of polluted loads by the untreated population. The use of eco-friendly fertilizers is recommended for rivers with a relatively high farmland ratio among rivers exceeding the target water quality due to non-point pollutant sources, and installation of boiling point reduction facilities that can reduce the amount of polluted load introduced during rainfall or manage water shores. In rivers with a large number of livestock breeding heads, the livestock houses located in these rivers need to be preferentially transferred to livestock manure treatment plants. Due to the high ratio of land area because of urbanization, initial rainwater treatment facilities are required to reduce the amount of pollutant load flowing into the river through the impermeable layer during rainfall.

• Journal of Advanced Navigation Technology
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• v.25 no.1
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• pp.17-28
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• 2021

Recently, eVTOL, the next-generation of eco-friendly transportation, has been in the spotlight due to global warming along with traffic jams in large cities of many countries. This study benchmark the external features of Hyundai Motors S-A1, a compound eVTOL combined fixed and tilt rotors among many types of eVTOLs, to create the basic configuration using reverse design techniques. Basic configurations were created using CATIA and aerodynamic analyses were performed using the aircraft design and aerodynamic analysis programs, OpenVSP, XFLR5, and the aircraft wetted area, drag, and lift were calculated after selecting the airfoil, incidence angle, and dihedral and anhedral angles through trade study. Also, required powers were estimated for completing the given mission profile and components weight and the total weight were predicted using the estimation formula and data survey.

• Korean Journal of Environment and Ecology
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• v.36 no.5
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• pp.468-480
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• 2022

Although the construction of the Nakdong River Estuary Barrage (NEB) improved the water supply in the region, it cut off the longitudinal connectivity of the estuary aquatic ecosystem. Thus, the social demands for opening the NEB have been continuously raised, and the efforts to restore the aquatic ecosystem of the Nakdong River estuary began in 2017. Many fish species have inhabited the Nakdong River estuary. Since their habitat and migration characteristics vary widely, the sluice gate operation considering them is essential for the restoration of the aquatic ecosystem. Therefore, in this study, we monitored the fish species living and migrating in the Nakdong River estuary and analyzed the possibility of smooth movement of for each fish species by calculating the average flow velocity according to the type and the height of the gate opening. Moreover, we selected the target fish species for each month and suggested the sluice gate operation according to the depth of the main habitat to present the measures that are ideal for optimal restoration of the aquatic ecosystem in the Nakdong River estuary area.

• SUVANNABHUMI
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• v.13 no.2
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• pp.109-134
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• 2021

Indonesia has undergone the rapid deforestation largely as a result of practical consequences of human overexploitation of the forest. Between 1950 and 2015, around 43% of the forest area in Indonesia had been lost (68.0 million hectares). The process of deforestation has partly been a response to the rapidly intensifying 'global' and 'domestic' economic demands. Deforestation in Indonesia is also indirectly due to 'materialism-driven' value system and the corresponding weakening of Indonesian ethics. Therefore, given that socio-cultural expressions of modern Indonesian value systems have mostly taken place within a framework of Islam, the aim of the paper is to attempt to find Islamic ethics in general, which can provide the basis of ecological ethics to prevent rapid deforestation in Indonesia. The paper is composed of the followings. First, following the 'Introduction', it outlines the historical process of deforestation in Indonesia and also its corresponding socio-economic contexts. Then it moves on to talk about ecological ethics in general, thereby emphasizing that the phenomenological problem of deforestation needs to be conceived at a philosophical level beyond ecological phenomena. After discussing the ecological ethics, the paper proceeds to examine Islamic ethics as a canonical framework of ecological ethics in Indonesia. In doing so, it attempts to apply the Islamic ethics to the diverse Indonesian society and then considers 'Pancasila' as a potential framework for a pragmatic link between Islam ethics and Indonesian society. Having said that, in conclusion, the paper argues that there is a need for 'concrete' translation of 'Pancasila' into implementation in an Indonesian context, thereby various agents (government, policy-practitioners, concessionaires and also all the Indonesian) may agree in saying 'no' to overexploitation of the forest, to rapid depletion of the forest and to 'unsustainable' development practices.