• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.11
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• pp.8-17
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• 2018

A large urban region in Bangkok, Thailand is often inundated due to shallow water floods along the paved roads that have poor drainage facilities, and that can cause urban flooding. Existing methods, including using sand bags are not effective to prevent flooding in urban areas where the amount of sand is not sufficient. Thus, it is necessary to install artificial flood defense structures. However flooding and overflow defense equipment, which was developed in some advanced nations in Europe and in the USA, is highly expensive and complex construction methods are needed, therefore they are not suitable to be used in Southeast Asia. Thus, it is necessary to develop a flood rapid defense system(FRDS), which is inexpensive and simple to build, but is also highly functional. Thus, this study developed an FRDS that can be applied to Southeast Asia through the careful study of FRDS overviews, an analysis on the development trends in Korea and overseas, and the proposal of development needs and directions of the region. For the system developed, Korean Standards(KS) performance evaluations on leakage ratio deformation tests and impact resistance tests were conducted at the Outdoor Demonstration Test Center(Seosan) in the Korea Conformity Laboratories(KCL) and the system satisfied the standards of KS F 2639(leakage and deformation test) and KS F 2236(impact resistance test). The present study results can not only be applied to urban floods in Southeast Asian nations to cope with flood-related disasters, but also be utilized in flood prone regions and for major facilities in Korea. They can also induce scientific and pro-active responses from major local governments and facility management organizations in relation to urban floods.

• Journal of the Korea Institute of Building Construction
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• v.19 no.2
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• pp.113-121
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• 2019

Single walled carbon nanotube (SWCNT) has been used as a material for reinforcing various advanced materials because it has superior mechanical properties. However, pure SWCNT that does not have any functional group has a hydrophobic character, and exists as bundles due to the strong Van der Waals attraction between each SWCNT. Due to these reasons, it is very difficult to disperse SWCNTs in the water. In this work, in order to use SWCNT for production of cementitious composites, SWCNT was first dispersed in water to make an aqueous solution. Sodium deoxycholate (DOC) and Sodium dodecyl sulfate (SDS) were chosen as surfactants, and the dosage of DOC and SDS were 2wt% and 1wt%, respectively. Sonication and ultracentrifugation were applied to separate each SWCNT and impurities. Using such processed SWCNT solutions, cement paste was prepared and its shear stress vs. strain rate relationship was studied. The yield stress and plastic viscosity of cement paste were obtained using Bingham model. According to the results in this work, cement pastes made with DOC and SDS showed similar rheological behavior to that of air entrained cement paste. While cement paste made with DOC 2 wt.% SWCNT solution showed similar rheological behavior to that of plain cement paste, cement paste made with SDS 1 wt.% SWCNT solution showed different rheological behavior showing much less yield stress than plain cement paste.

• Advances in concrete construction
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• v.10 no.4
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• pp.301-310
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• 2020

The following paper concentrates on the objective of studying the influences of extent of duration and temperature on the Pozzolanic properties as well as reactivity of locally existing natural clay of Nai Gaj, district Dadu, Sindh Pakistan. The activation of the clay only occurs through heating when temperature in a furnace chamber reaches 600, 700 and 800oC for 1, 2 and 3 hours and at 900 and 1000℃ for 1 and 2 hours. Furthermore, the strength activity index (SAI) of advanced pozzolanic material happens to be identified through 20% cement replacement for different samples of calcined clay as per ASTM C-618. The compressive strength test of samples had been operated for 7 and 28-days curing afterwards. The maximum compressive strength had been seen in mix E in which cement was replaced with clay calcined at 700℃ for 1 hour that is 27.05 MPa that is 24.31% more than that of control mix. The results gathered from the SAI verdicts the optimal activation temperature is 700℃ within a one-hour time period. The SAI at a temperature of 700℃ with a one-hour duration at 28 days is 124.31% which happens to satisfy the requirements of the new Pozzolanic material, in order to be applied in mortar/concrete (i.e., 75%). The Energy- dispersive spectrometry (EDS) along with the X-ray diffraction (XRD) have been carried out in means of verifying whether there is silica content or amorphous silica present in metakaolin that has been developed. The findings gathered from the SAI were validated, as the analysis of XRD verified that there is in fact Pozzolanic activity of developed metakaolin. Additionally, based on observation, the activated metakaolin holds a significant influence on the increase in mortar's compressive strength.

• Spatial Information Research
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• v.10 no.1
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• pp.1-14
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• 2002

Due to the rapid development in information technology, countries of advanced information technology and multi-national information communication industries have expanding their invesment in constructing a cyber territory or a cyber city, and even a cyber globe that combines the real world with the cyber world. As such, in order to keep up with the competition with other countries to secure the Invisible Continent, Korea cannot afford to fall behind in the preparation and efforts to construct a cyber territory. Therefore in preparation for the inevitable establishment of a cyber territory, this study defined the concept of a cyber territory clearly and proposed a promotional strategy needed by the government for the establishment of a cyber territory. A cyber territory is 'the dynamic second territory that realizes various values in various aspects through organically combining innumerable active bodies in a surreal space and that are created by systematically and optimally connecting the physical topographical space and activity of the first nation to the cyberspace'. To explain further, a cyber territory is defined as another simulated space not only to manage the land systematically and deal with administrative services far the greater population, but also to contain economic activities of corporations and the citizens' everyday lives in a virtual reality by digitizing the entire territory including even the sea. In order to establish such cyber territory, it is necessary to revise related laws and policies, to foster related technology and industry as a main engine for national development, to promote public awareness, and to train related human resources.

• Journal of Energy Engineering
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• v.21 no.3
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• pp.281-291
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• 2012

Recently, global economy has recovered and aspects of the renewable energy industry in the global competition is more fierce, the new growth engines of the major countries, including the United States and China, industry promotion policy as being deployed. Major advanced countries and Korea also invested a lot of money to wind power development as a part of renewable energy development and promoting the construction of wind power generation. The global wind power generation market is expected to further increase the scale to about 70 billion US dollars, thus, Korea as well as the installation of domestic wind power overseas actively considering. This study uses input-output analysis to estimate the role of wind power generation sector exports national economy. More specifically, this study shows what national economy effect of production-inducing effect, value-added inducing effect, and employment-inducing effect are explored with demand-driven moel. After define wind power generation sector what small sized of Input-Output table 168 sectors among 11 sectors, this study pays particular and close attention to wind power generation sector by taking the sector as exogenous specification and then investigating economic impacts of it. The wind power generation exportation case of overseas 100 billion won, production-inducing effect, value-added inducing effect, and employment-inducing effect are 205 billion won, 68 billion won and 1,054 persons, respectively. These quantitative information can be usefully utilized in the policy-making for the industrialization of wind power generation exports.

• Journal of the Korean GEO-environmental Society
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• v.22 no.11
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• pp.15-21
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• 2021

Losses of both life and property increased from damage to underground pipe such as heat transmission pipe buried underground in downtown because pipes are gradually aging. Considering the characteristics of the heat transmission pipe, which is not exposed to the outside and difficult to immediately identify problems such as damage, it is realistic to indirectly check the condition of the facility based on the historical information that is periodically collected through facility maintenance. In this study, a methodology for estimating the damage probability was developed by examining the history information of the heat transmission pipe, deriving an evaluation factor that is related to the damage probability. The contribution factor of the damage probability were reviewed by analyzing not only the guidelines for maintenance of heat transmission pipe of advanced European countries and domestic district heating companies, but also the cases of waterworks with similar characteristics. Evaluation factors were selected by considering not only the correlation with the damage probability but also the possibility of securing data. Based on 1999, when the construction technology and standards of heat transmission pipe changed, the damage probability estimation function according to the period of use was divided into the case of being buried before 1998 and the case of being buried after 1999, and presented. In addition, the damage probability was corrected by assigning weights according to the measured data for each evaluation factor such as the diameter, use, and management authority.

• The Journal of Engineering Geology
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• v.33 no.2
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• pp.275-291
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• 2023

Global warming has made the polar regions more accessible, leading to increased demand for the construction of new resource-development plants in oil-rich permafrost regions. The selection of locations of resource-development plants in permafrost regions should consider the surface displacement resulting from thawing and freezing of the active layer of permafrost. However, few studies have considered surface displacement in the selection of optimal locations of resource-development plants in permafrost region. In this study, Analytic Hierarchy Process (AHP) analysis using a range of geospatial information variables was performed to select optimal locations for the construction of oil-sands development plants in the permafrost region of southern Athabasca, Alberta, Canada, including consideration of surface displacement. The surface displacement velocity was estimated by applying the Small BAseline Subset Interferometric Synthetic Aperture Radar technique to time-series Advanced Land Observing Satellite Phased Array L-band Synthetic Aperture Radar images acquired from February 2007 to March 2011. ERA5 reanalysis data were used to generate geospatial data for air temperature, surface temperature, and soil temperature averaged for the period 2000~2010. Geospatial data for roads and railways provided by Statistics Canada and land cover maps distributed by the North American Commission for Environmental Cooperation were also used in the AHP analysis. The suitability of sites analyzed using land cover, surface displacement, and road accessibility as the three most important geospatial factors was validated using the locations of oil-sand plants built since 2010. The sensitivity of surface displacement to the determination of location suitability was found to be very high. We confirm that surface displacement should be considered in the selection of optimal locations for the construction of new resource-development plants in permafrost regions.

• International Journal of Industrial Entomology and Biomaterials
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• v.1 no.2
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• pp.95-102
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• 2000

Experiments related to the field of sericulture started in the years 1900, in Korea. The sericultural experimental station in Korea was first organized among agricultural fields in Korea, indicating that sericulture in Korea was regarded as an important field of agriculture. Sericulture has been devoted to a great deal for the improvement of Korean economy during the past 100 years even under the coarse social circumstances caused particularly by the Korean War, However, the traditional Korean sericulture, aimed to produce silk yarn, was weakened, because of several reasons such as diminishment in silk consumption, increased labor charge in Korea, and so on. After this difficulty time, the Korean sericulture was revolutionized by shifting into functional sericulture from 1995, and the Korean sericulture now plays an important role for the improvement of human health. Mulberry tree, silkworm, and silk have a boundless potential to be developed as resources. We expect the know-how obtained through silkworm research would expand to the other insect research too. Thus, an area of entomological industry is hoped to prosper owing to insect research as well as sericulture. Mulberry tree is known to possess many bio-active substances, so it can be utilized as a resource for substitute medicine and a raw material for the functional food. In addition, an invention of genetically engineered mulberry variety, which will produce more bioactive substances, is expected. Silkworm is one of the most extensively studied insect organisms on the genome so far, Thus, silkworm is expected to be an "insect bio-factory", enabling mass-production of useful proteins by transformation, in which useful foreign genes are assimilated into silkworm. Silk can be transformed into several phases, because it possesses useful functional groups, which are sensitive to chemical reaction. Also, because silk fibrin itself is protein, it has a superior applicability as tissue membrane. Due to this usefulness, many researchers are now working on the silk as food, cosmetic, medical resource, and bioengineering resource, and even an expanded application is expected using silk in the future. Until now, the researches on insects were largely focused on the prevention of the damage caused by pest, instead of a beneficial aspect. However, insects are thought to be the fourth natural resource in the world, possessing unlimited potential as world resources in the near future. Therefore, our entomological research effort should be focused on the subject with potential for industrialization. Such subject includes selecting the insect species useful for environmental evaluation, construction of environment-friendly agricultural ecosystem, pollen mediation, pet, and advanced bio-resources.

• Journal of Environmental Science International
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• v.14 no.12
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• pp.1119-1127
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• 2005

The management of data on biological diversity is presently complex and confusing. This study was initiated to construct a database so that such data could be stored in a data management, and analysis instrument to correct the problems inherent in the current incoherent storage methods. MySQL was used in DBMS(DataBase Management System), and the program was basically produced using Java technology Also, the program was developed so people could adapt to the requirements that are changing every minute. We hope this was accomplished by modifying easily and quickly the advanced programming technology and patterns. To this end, an effective and flexible database schema was devised to store and analyze diversity databases. Even users with no knowledge of databases should be able to access this management instrument and easily manage the database through the World Wide Web. On a basis of databases stored in this manner, it could become routinely used for various databases using this analysis instrument supplied on the World Wide Web. Supplying the derived results by using a simple table and making results visible using simple charts, researchers could easily adapt these methods to various data analyses. As the diversity data was stored in a database, not in a general file, this study makes the precise, error-free and high -quality storage in a consistent manner. The methods proposed here should also minimize the errors that might appear in each data search, data movement, or data conversion by supplying management instrumentation on the Web. Also, this study was to deduce the various results to the level we required and execute the comparative analysis without the lengthy time necessary to supply the analytical instrument with similar results as provided by various other methods of analysis. The results of this research may be summerized as follows: 1)This study suggests methods of storage by giving consistency to diversity data. 2)This study prepared a suggested foundation for comparative analysis of various data. 3)It may suggest further research, which could lead to more and better standardization of diversity data and to better methods for predicting changes in species diversity.

• Journal of the Korean Geotechnical Society
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• v.32 no.12
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• pp.79-91
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• 2016

Geosynthetic-reinforced and Pile-supported (GRPS) embankment method is widely used to construct structures on soft ground due to restraining residual settlement and their rapid construction. However, effect of cyclic loading has not been established although some countries suggest design methods through many studies. In this paper, cyclic loading tests were conducted to analyze dynamic load transfer characteristics of pile-supported embankment reinforced with geosynthetics. A series of 3 case full scale model tests which were non-reinforced, one-layer-reinforced, two-layer reinforced with geosynthetics were performed on piled embankments. In these series of tests, the height of embankment and pile spacing were selected according to EBGEO (2010) standard in Germany. As a result of the vertical load parts on the pile and on the geosynthetic reinforcement measured separately, cyclic loads transferred by only arching effect decreased with strength geosynthetic-reinforced case. However, final loads on the pile showed no differences among the cases. These results conflict with previous studies that reinforcement with geosynthetics increases transfer load concentrated on piles. In addition, it is observed that the load transferred to pile decreases at the beginning of cycle number due to reduction of arching effected by cyclic loading. Based on these results, transferred mechanism for cyclic load on GRPS system has been presented.