• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.23 no.4
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• pp.375-384
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• 2005

Three dimensional urban models are being increasingly applied for various purposes such as city planning, telecommunication cell planning, traffic analysis, environmental monitoring and disaster management. In recent years, technologies from CAD and GIS are being merged to find optimal solutions in three dimensional modeling of urban buildings. These solutions include modeling of the interior building space as well as its exterior shape visualization. Research and development effort in this area has been performed by scientists and engineers from Computer Graphics, CAD and GIS. Computer Graphics and CAD focussed on precise and efficient visualization, where as GIS emphasized on topology and spatial analysis. Complementary research effort is required for an effective model to serve both visualization and spatial analysis purposes. This study presents an efficient way of using the CAD plans included in the building register documents to reconstruct the internal space of buildings. Topological information was built in the geospatial database and merged with the geometric information of CAD plans. as well as other attributal data from the building register. The GIS network modeling method introduced in this study is expected to enable an effective 3 dimensional spatial analysis of building interior which is developing with increasing complexity and size.

• Journal of the Korean Society for Nondestructive Testing
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• v.29 no.5
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• pp.427-435
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• 2009

Cylindrical structures such as pipes and shafts are widely used in various industrial facilities. Recently, researches on magnetostrictive transduction of torsional waves have been actively reported for the nondestructive evaluation of those cylindrical structures. However, the existing magnetostrictive patch transducer has somewhat inconvenient and time.consuming process like patch bonding to a structure since it should employ a magnetostrictive patch having strong magnetostriction. To overcome these limitations of the existing transducer, in this work, we develop a novel modular magnetostrictive transducer to generate and measure torsional waves to inspect a cylindrical structure. The proposed transducer can be applied as viscous liquid coupling with shear couplant or dry coupling without coupling media instead of patch bonding to a structure. We describe a detailed structure of the modular transducer and conduct some experiments to verify its performance.

• Korean Journal of Soil Science and Fertilizer
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• v.8 no.3
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• pp.153-160
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• 1975

Jeju island has high potential productivity of livestock in terms of climate, geography, and economic prospect. Grass-land is now widespread and increasing rapidly year after year. However, the productivity of grass land is very low compared with that of main land. It is supposed that the low productivity is due to improper chemical properties of volcanic ash soil which is mostly distributed in the island. Volcanic ash soil, which have high alumina ratio, is characterized by the lack of bases and avilable phosphorous while its phosphorous fixation capacity is very high. In addition to poor chemical properties, low level of fertilization technique appears to be another limitation to grass production. Farmers have not given care to improve their soil to be suitable for grass cultivation. In order to increase the productivity of grassland in Jeju, the proper amounts of N, P, and K fertilizer should be applied following the improvements of poor chemical properties such as liming and a great deal of phosphorous increment, using mainly fused phosphate, based upon the balance of bases, and the application of organic matter and micro-elements which can be easily deficient in soil.

• Journal of Information Technology and Architecture
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• v.11 no.4
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• pp.427-439
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• 2014

Introduction of new information systems due to continuous progress of ICT has made the enterprise IT environment into a mixed pot of various IT resources. Rapidly changing business situation has emphasized the integration of organizational IT resources as one of key competitive advantages. Those distributed IT resources are now demanding to solve the problems not only on their own effective management but also on security and control issues against unauthorized infiltration and information leakages. Under the situation that the number of IT resources is constantly increasing, it is needed to study a management model and its implementation that integrally solves above all problems. In this paper, it is revealed that a directory service can be used to integrally manage distributed IT resources and a directory service based system model for distributed IT resource management is suggested. By implementing an HR solution over active directory service, it is demonstrated that our integrated management model for distributed resources is applicable to real business cases. It is expected that for small and medium sized enterprises with limited IT investments, directory service based IT resource management system can be a cost-effective solution for increasing security threats and lack of governance.

• The KIPS Transactions:PartC
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• v.15C no.6
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• pp.573-586
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• 2008

The improved performance and miniaturization of computer and the improvement of wireless communication technology have enabled the emergence of many high quality services. Among them multicast services are receiving much attention and their usage is increasing due to the increase of Internet multimedia services such as video conference, multimedia stream, internet TV, etc. Security plays an important role in mobile multicast services. In this paper, we proposed a secure multicast protocol for a hierarchical micro-mobility environment. The proposed secure multicast protocol provides security services such as authentication, access control, confidentiality and integrity using mechanisms including symmetric/asymmetric key crypto-algorithms and capabilities. To provide forward/backward secrecy and scalability, we used sub-group keys based on the hierarchical micro-mobility environment. With this security services, it is possible to guard against all kinds of security attacks performed by illegal mobile nodes. Attacks executed by internal nodes can be thwarted except those attacks which delete packet or cause network resources to be wasted. We used simulator to measure the performance of proposed protocol. As a result, the simulation showed that effect of these security mechanisms on the multicast protocol was not too high.

• Transactions of the KSME C: Technology and Education
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• v.1 no.1
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• pp.107-113
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• 2013

This paper presents the process of turbine development for Organic Rankine Cycle(ORC) system. Development of turbine for ORC system is hot issue in the electric generation market due to the characteristic of organic refrigerant which the evaporate temperature is lower than general refrigerant. Recently, the industry have an interest about ORC turbine development in Korea, and they presented numerous research results. In developing the turbine, several processes can be considered. However, there was few document about ORC turbine development because of the trade secret. This paper can be used as a reference in developing ORC turbine.

• Archives of design research
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• v.20 no.1 s.69
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• pp.243-252
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• 2007

Nowadays, technological differences between companies have decreased and products launched show more resemblance to each other. As an alternative plan companies started developing brands. The excellence in quality of a product from a company could be easily copied, but the formless value, brand, cannot be imitated easily. More importantly, in the globally competing generation the brand provides distinctiveness and gives a solution to the relationship between consumers. Also the design image takes a big part in a company's competitiveness. The design image that represents the company reflects the brand, and it reflects the image and the philosophy of the company. And the images of each product influence the brand. Also an effective delivery of a product image would give a synergistic effect on the brand. A company could build this design identity to elevate the brand. Therefore, the identity of design image reflects the brand. Therefore a study on the area of the absence and misled identity of design image is important. This study is fixed on the idea of, development of brand to increase competitiveness, and the affiliation of design image with the identity of the brand. This study, on the basis of preceding research and theoretical background, aims to find the design identity area focusing on the product design image of the product purchased by the consumer. Firstly, we need to examine the affinity of the product image from the consumer, and analyse the direction of images to offer a solution that could advance the design identity strategy.

• School Mathematics
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• v.15 no.2
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• pp.459-479
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• 2013

The Purpose of this study was to explore the methods of generalization and errors pattern generated by mathematically gifted students and non-gifted students in elementary school. In this research, 6 problems corresponding to the x+a, ax, ax+c, $ax^2$, $ax^2+c$, $a^x$ patterns were given to 156 students. Conclusions obtained through this study are as follows. First, both group were the best in symbolically generalizing ax pattern, whereas the number of students who generalized $a^x$ pattern symbolically was the least. Second, mathematically gifted students in elementary school were able to algebraically generalize more than 79% of in x+a, ax, ax+c, $ax^2$, $ax^2+c$, $a^x$ patterns. However, non-gifted students succeeded in algebraically generalizing more than 79% only in x+a, ax patterns. Third, students in both groups failed in finding commonness in phased numbers, so they solved problems arithmetically depending on to what extent it was increased when they failed in reaching generalization of formula. Fourth, as for the type of error that students make mistake, technical error was the highest with 10.9% among mathematically gifted students in elementary school, also technical error was the highest as 17.1% among non-gifted students. Fifth, as for the frequency of error against the types of all patterns, mathematically gifted students in elementary school marked 17.3% and non-gifted students were 31.2%, which means that a majority of mathematically gifted students in elementary school are able to do symbolic generalization to a certain degree, but many non-gifted students did not comprehend questions on patterns and failed in symbolic generalization.

• The Journal of the Korea Contents Association
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• v.13 no.5
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• pp.82-89
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• 2013

The phase in digital technology expedited low-budget digital film productions in the Korean film industry; hence the international film festivals circuit became the launching pad for Korean directors as they built their reputation and careers around the critical acclaim. Pieta (Kim Ki-Duk)'s Claim on Golden Lion prize at the Venice Film Festival in 2012 would be one of the splendid achievements - the festival is considered to be one of the top the international film festival. However, the increased volume of the low-budget digital film productions are not necessarily proportional to the growth in the quality of the productions. The drawbacks to the production system appeared to be the underlying cause. In attempt to approach the issue, this article explores the production system from 2000 until now. It is illustrated that the value chain model has been transformed from general ones into vertical & horizontal integrated ones. A notable example of successful indie bands-around Hongik university area-, as well the analysis on the low-budget hit productions, especially from the mid-2000's, are introduced as the case studies. The strategies that led the success, such as subsidies policy, the tax benefits on investment firms and production companies, and the aid in international film festival submissions on low-budget digital film productions, are thus examined with further suggestions.

• Microbiology and Biotechnology Letters
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• v.40 no.2
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• pp.83-91
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• 2012

Quorum sensing (QS) is a cell-to-cell communication system, which is used by many bacteria to regulate diverse gene expression in response to changes in population density. Bacteria recognize the differences in cell density by sensing the concentration of signal molecules such as N-acyl-homoserine lactones (AHL) and autoinducer-2 (AI-2). In particular, QS plays a key role in biofilm formation, which is a specific bacterial group behavior. Biofilms are dense aggregates of packed microbial communities that grow on surfaces, and are embedded in a self-produced matrix of extracellular polymeric substances (EPS). QS regulates biofilm dispersal as well as the production of EPS. In some bacteria, biofilm formations are regulated by c-di-GMP-mediated signaling as well as QS, thus the two signaling systems are mutually connected. Biofilms are one of the major virulence factors in pathogenic bacteria. In addition, they cause numerous problems in industrial fields, such as the biofouling of pipes, tanks and membrane bioreactors (MBR). Therefore, the interference of QS, referred to as quorum quenching (QQ) has received a great deal of attention. To inhibit biofilm formation, several strategies to disrupt bacterial QS have been reported, and many enzymes which can degrade or modify the signal molecule AHL have been studied. QQ enzymes, such as AHL-lactonase, AHL-acylase, and oxidoreductases may offer great potential for the effective control of biofilm formation and membrane biofouling in the future. This review describes the process of bacterial QS, biofilm formation, and the close relationship between them. Finally, QQ enzymes and their applications for the reduction of biofouling are also discussed.