• Journal of the Korea Concrete Institute
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• v.22 no.2
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• pp.219-228
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• 2010

It has been well known that concrete structures exposed to acid and sulfate environments such as sewer, sewage and wastewater, soil, groundwater, and seawater etc. show significant decrease in their durability due to chemical attack. Such deleterious acid and sulfate attacks lead to expansion and cracking in concrete, and thus, eventually result in damage to concrete matrix by forming expansive hydration products due to the reaction between portland cement hydration products and acid and sulfate ions. Objectives of this experimental research are to investigate the effect of mineral admixtures on the resistance to acid and sulfate attack in concrete and to suggest high-resistance concrete mix against acid and sulfate attack. For this purpose, concretes specimens with three types of cement (ordinary portland cement (OPC), binary blended cement (BBC), and ternary blended cement (TBC) composed of different types and proportions of admixtures) were prepared at water-biner ratios of 32% and 43%. The concrete specimens were immersed in fresh water, 5% sulfuric acid, 10% sodium sulfate, and 10% magnesium sulfate solutions for 28, 56, 91, 182, and 365 days, respectively. To evaluate the resistance to acid and sulfate for concrete specimens, visual appearance changes were observed and compressive strength ratios and mass change ratios were measured. It was observed from the test results that the resistance against sulfuric acid and sodium sulfate solutions of the concretes containing mineral admixtures were much better than that of OPC concrete, but in the case of magnesium sulfate solution the concretes containing mineral admixtures was less resistant than OPC concrete due to formation of magnesium silicate hydrate (M-S-H) which is non-cementitious.

• Korean Journal of Environment and Ecology
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• v.21 no.3
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• pp.290-298
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• 2007

The results of this research on the diversity, zonation of vegetation and micro-topography by TWINSPAN classification and DECORANA ordination, executed with Sinduri coastal dunes of Korea, are as follows: The vegetation and micro-topography of coastal dunes formed a noticeably clear zonation structure. The beach in the direction of the coastline saw a lot of appearance of Salsola komarovi and the primary dune was dominated by Elymus mollis. Imperata cylindrica var. koenigii and Carex pumila formed a colony at flat area of the sand hills and Calamagrostis epigeios was widely distributed at the wet slack. The secondary dune was dominated mostly by Ischaemum anthephoroides and Imperata cylindrica var. koenigii, and it showed an aspect of the distribution of Vitex rotundifolia and Rosa rugosa. while the hinterland hillside in the direction of inland was dominated by Robinia pseudo-acacia and Pinus thunbergii. However, Carex kobomugi, known as the pioneer species of the coastline-bound areas at the coastal dune, dominantly occupied the secondary dune of the rear side and continentally-inclined Miscanthus sinensi and Oenothera biennis of naturalized plant were irregularly spread over the whole of the coastal dune, so the stabilization of micro-topography seemed to be uncertain. Particularly, Miscanthus sinensis was predicted to be changed into dominant species of the primary dune, and secondary dune and slack having a commonly high species gathering inclination with the more progress of stabilization of the coastal dune. The expansion of sand hill wetlands and roads located between the primary dune and secondary dune was judged to have an effect on the zonation structure of plant distribution.

• Journal of Science and Technology Studies
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• v.12 no.1
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• pp.1-43
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• 2012

This paper examines the American Civil Liberties Union(ACLU)'s recent legal challenge on patents held by Myriad Genetics on two genes (BRCA1 and BRCA2) associated with a high risk of breast and ovarian cancer. Instead of analyzing the ACLU's objections to the BRCA patents in terms of its legal technicalities and normative ethical principles, this paper seeks to situate this legal case in the broader historical context of the shifting understanding of the relationship between private ownership, economic development, and the public interest in academic sciences. This paper first briefly chronicles a series of scientific developments and key legal decisions involving patenting of life forms, including genetically engineered micro-organisms animals and biological materials of human origins like cell cultures and genes, that led to the US Patent and Trademark Office(USPTO)'s official guidelines on human gene patenting in 2001. At another level, this paper analyzes the expansion of the scope of intellectual property rights in the life sciences in terms of shifting economic and legal assumptions about public knowledge and its role for economic development in the 1970s. I then show how these economic, legal, and ethical ideas that linked private ownership and the public interest have been challenged from the 1990s, calling for revisions in intellectual property laws regarding a wide array of life forms. The tragedy of the anticommons in human gene patenting, according to ACLU, has severely undermined creative scientific activities, medical innovations, access to health care and rights to life among cancer patient groups. ACLU's objection to human gene patenting on several US-constitutional grounds in turn suggests issues regarding intellectual property are critically linked to vital issues pertinent to the creative communities in arts and sciences, such as free exchange of ideas, censorship and monopoly, and free expression and piracy etc.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.22 no.3
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• pp.225-232
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• 2004

The human history has progressed closely related to land. Mankind started land administration as a tool of governance to make land the object of imposing taxation as well as developing the land administration as a concept of securing property rights. People have drawn boundary lines on the ground to form a land parcel according to the usage and/or ownership. Furthermore, the land administration has been developed as a registering system of cadastral records fer the public announcement of fixed boundary instead of changeable ground boundary. Currently the citizens demand the provision of accurate and diverse information on the land which is assessed to has high property value encouraged by the rapid development in the post-industrial society today. However, even though the fact that the Korean cadastral registers produced during the Land Investigation Project are still practically in use causes land-related disputes and promotes public mistrust because of the changed boundaries by parcel mutation, the expansion and contraction of map sheets and the quality deterioration and damage of map paper, but the ultimate resolution is not yet made so far. The distance difference between boundary points are compared and analyzed using TS surveying method in the research as a methodology to resolve the boundary inconsistency, the current problem of cadastral records. Consequently, I'd say that the new surveying method of registering the coordinates of real ground boundary has been regarded as more efficient than considering the matter on the map regardless of urban or rural areas.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.6
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• pp.1775-1781
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• 2008

The effects of the type of curing agent on the swelling of the natural rubber(NR) sponge applicable to the self-sealing layer of a helicopter fuel tank were investigated. The curing systems employed were peroxide and mixed ones of sulfur and peroxide. The NR compounds were prepared in a kneader and a roll-mill. The compounds were partially cured in a press at high pressure and subsequently cured fully with expansion in another press at atmospheric pressure. The apparent density of the NR sponge was measured and the cell structure was observed with scanning electron microscopy. The swelling experiments were performed at room temperature using toluene, iso-octane, and an aircraft fuel as a solvent. More rapid volume swelling of the NR sponge cured by peroxide was achieved than cured by sulfur and peroxide with similar amount of curing agent added in rubber compounds. The apparent density and cell structure of the sponge were extremely sensitive to the amount of peroxide, which influences again the swelling behavior of the NR sponge. It is important to control properly two reactions of decomposition of foaming agent and crosslinking of NR in the mold to obtain rapid swelling of the NR sponge on contact of the fuel.

• Journal of the Korean Institute of Gas
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• v.2 no.2
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• pp.18-25
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• 1998

According to the requirements of ANSI B3l.8, the pipe thickness is determined with hoop stress resulted from internal pressure. And the other loads induced by soil, vehicle, thermal expansion, ground subsidence, etc shall be evaluated rationally. There are two ways of calculating stress of buried gas pipeline. The first is FEM. FEM can calculate the stress regardless of the complexity of pipeline shape and boundary conditions. But it needs high cost and long time. The second is the way to use equation. The reliable equations to calculate the stress of buried gas pipeline was developed and have been used in designing pipeline and evaluating pipeline safety, But these equation are very difficult to understand and use for non-specialist. For easy calculation of non-specialist, the new computer program to calculate stress of buried natural gas pipeline have been developed. The stress is calculated by the equations and extrapolation of the graph resulted from FEM. The full paper is consist of series I and II. In this paper, series I, the calculating equation of the program is explained in detail.

• Archives of design research
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• v.18 no.3 s.61
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• pp.55-62
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• 2005

Recently, the opening of the world economy and regional ization of national demand endless endeavors and investments to upbring design-industry for regional economic development. Our domestic commodities, declined in price competitiveness against China and Southeast Asian nations, need construction of brand image of commodities and consumers' response through expanded concernments in marketing spheres. The design-industry is a important means to strengthen competitiveness of the domestic industry through discrimination of commodities and creativity of high added value. Design-industry has some problems in circumstances; commodity development and marketing are below the level in the sphere of manufacture industry yet and businessmen are unwilling to invest demanded for development of new design. Establishment of the personal foundation, useful for accumulating competent designers' experiences and technologies, can not pass limit. In addition, a system and a policy to protect design-industry have a problem in effectiveness. Concrete strategies to activate design industry which meets social and cultural circumstances of Daegu and Gyeongbuk region are to establish policy for construction of specialists' infra, systematization of study & development of design, common ownership of information on design, and expansion of design company. The business to upbring design in the region should be operated to develop competitive commodities which is helpful to the regional economy and to increase value of the regional enterprises' brand. In addition, foundation of design should be expanded personal, material, and informational infra through design-centered so that they are helpful to activate economy of Daegu and Gyeongbuk through making design reformational cluster.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.2
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• pp.987-994
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• 2015

This study examines how single-person household expenditure patterns are different with respect to age and income groups using Tobit model. The expenditure data of the national household survey from 2006 to 2012 were used. The results show that income elasticities of all items are greater than 1 except for food & beverage, housing, water, electricity & gas, and Communication. Income elasticities are significantly different among consuming items. Additionally the income elasticities are also different between various age and income groups of single-person households. Therefore governments and businesses have to take this into account when devising their policies or strategies regarding single-person households. Especially, businesses need to adopt a strategy targeted at single-person households with high income and buying power such as unmarried professional people. As the number of single-person household increases the proportion of expenditures on necessities such as beverage, food, and energy is expected to decrease while that on services increases. Consequently policy responses are required to prepare for the expansion of service industries such as health, hospital, and housekeeping services.

• KIPS Transactions on Computer and Communication Systems
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• v.3 no.8
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• pp.261-270
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• 2014

As Internet traffic increases recently, much effort has been put on improving the performance of a web server. In addition to hardware side solutions such as replacement by high-end hardware or expansion of the number of servers, there are software side solutions to improve performance. Recent studies on these software side solutions have been actively performed. In this paper, we identify performance degradation problems occurring in a conventional TCP networking reception process and propose a way to solve them. We improve performance by combining three kinds of existing methods for Linux Networking Performance Improvement and two kinds of newly proposed methods in this paper. The three existing methods include 1) an allocation method of a packet flow to a core in a multi-core environment, 2) ITR(Interrupt Throttle Rate) method to control excessive interrupt requests, and 3) sk_buff data structure recycling. The two newly proposed methods are fd data structure recycling and epoll_event data structure recycling. Through experiments in a web server environment, we verify the effect of our two proposed methods and its combination with the three existing methods for performance improvement, respectively. We use three kinds of web servers: a simple web server, Lighttpd generally used in Linux, and Apache. In a simple web server environment, fd data structure recycling and epoll_event data structure recycling bring out performance improvement by about 7 % and 6%, respectively. If they are combined with the three existing methods, performance is improved by up to 40% in total. In a Lighttpd and an Apache web server environment, the combination of five methods brings out performance improvement by up to 36% and 20% in total, respectively.

• Weed & Turfgrass Science
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• v.2 no.2
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• pp.184-190
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• 2013

It is important for genetic resources to collect and identify in native medium-leaf type zoysiagrasses species distributed in Korea. This study was conducted to investigate morphological variation and characteristics of native medium-leaf type zoysiagrasses from coastal, island and inland regions in Korea. Among them, 75 collected lines was confirmed to have various morphological variations, accessions were classified into 2 main based group coastal and inland regions by morphological characteristics and site environment. Group I included Z. sinica type, this group showed 3.7 mm in leaf width, 29 in number of seed per spikelet and 5.0 mm in seed length. Group II included Z. japonica type, this group showed 4.4 mm in leaf width, 42 in number of seed per spikelet and 3.5 mm in seed length. There is a need for additional research on growth characteristics and the molecular level for the introgressive hybridization between species which confirmed that cross-pollination is possible due to protogyny. The individuals showing variations should be preserved as valuable genetic resources for the expansion of variations in zoysiagrasses, and the results of this investigation on the genetic resources collected will be highly valuable in breeding high quality turfgrass.