• Journal of KIISE:Information Networking
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• v.32 no.6
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• pp.705-715
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• 2005

A peer-to-peer web caching has been studied recently as it can reduce the traffic converged on the server side and can support the traditional web caching model. Although the peer-to-peer web caching has the merit of having additional cache space from the local caches of peers without additional infrastructure, several constraints such as dynamic participation and local caching strategy caused by the autonomy of peers in peer-to-peer networks nay limit the performance of the peer-to-peer web caching. To overcome these limitations, we propose an efficient directory-based peer-to-peer web caching system under dynamic participation of peers. In the proposed caching system, we present new peer selection and replica management schemes by introducing the concept of the object lifetime in P2P networks. We evaluate the effectiveness of the proposed system through trace-driven simulations with a web log dataset. Simulation results show that the proposed system has higher accuracy and fewer redirection failures than the conventional directory-based P2P web caching system in feasible peer-to-peer networks.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.8
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• pp.634-641
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• 2019

The world's population reached 7.7 billion in 2019. Despite this trend, not all cities are growing. Most of the growing population is driven to large cities for convenience and jobs. This phenomenon has led to a decrease in the population of small and medium-sized cities, and in certain cities, a decrease in employment as well as recession have resulted. Korea is no exception. The nation's population is concentrated in the metropolitan cities. To solve these problems, researchers started to study how to deal with the contraction of a city, i.e., a shrinking city, rather than focusing on only the growth of a city. In this paper, demographically outstanding declined domestic cities were selected as shrinking cities and their characteristics were analyzed. The concept of smart shrinking cities was then defined for the selected cities, which were chosen as a good case in overseas countries to solve the shrinking city problem. Through this process, the strategic differences were compared between domestic and oversea cases. As a result, a modified strategy for the smart shrinking city concept, FSSC (flexible smart shrinking city), is proposed as an alternative strategy that can save resources and cost.

• Journal of international Conference on Electrical Machines and Systems
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• v.2 no.2
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• pp.216-224
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• 2013

This paper describes dual inverter drive for a fractional-slot concentrated winding permanent magnet synchronous machine (PMSM). PMSMs are widely used in many applications from small servo motors to few megawatts generators thanks to its high efficiency and torque density. Especially, fractional-slot concentrated winding PMSM is very popular in the applications where wide operation range is required because it shows very wide constant power speed ratios. High speed operation, however, requires lots of negative daxis current for reducing back-EMF regardless of output torque. Field weakening current does not contribute to the torque generation in surface mounted PMSM case and causes inverter and copper loss. To reduce the losses from field weakening current, this paper proposes PMSM with split stator and parallel dual inverter drive. Proposed parallel dual inverter drive reduces back-EMF and enables efficient drive at high speed and light load situation. Control strategy of proposed dual inverter system is established through loss analysis and simulation. Proposed concept is verified with practical experiment.

• Human Ecology Research
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• v.62 no.3
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• pp.399-408
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• 2024

Food literacy (FL) refers to the ability to understand and utilize food information. This concept consists of functional (FFL), interactive (IFL), and critical food literacy (CFL). In today's massive information-driven society, FL needs must be paid attention to as a determinant of health along with health literacy. This study sought to identify the FL of Korean adults, and to analyze the association between FL and nutritional status. Data was collected through an online self-reported survey among 1,355 Korean adults aged 19 to 64 years, stratified by gender and age. An χ² -test, student's t-test, ANOVA, analysis of covariance (ANCOVA), and multinomial logistic regression were performed using IBM SPSS 25.0. There were significant differences in the subjects' FFL, IFL, and CFL according to their gender, age, residence area, work type, and monthly income. Furthermore, it was confirmed that subjects with a higher nutrition quotient (NQ) grade also had higher FLs. Additionally, FFL and CFL contributed to improving the NQ grade. This study is meaningful in that it investigated the FL of Korean adults and provided data to identify populations that are particularly vulnerable to a lack of FL. In addition, it was confirmed that FL can have a positive effect on the nutritional status of adults. In conclusion, this study suggests the possibility of using FL as an intervention strategy to improve nutrition.

• Proceedings of the Korea Technology Innovation Society Conference
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• 2006.11a
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• pp.15-41
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• 2006

The increasing popularity of the concept of technology innovation has been driven by greater international competition in a rapidly globalizing economy. Both countries and enterprises are placing more and more emphasis on it in order to gain competitive advantages. This article gives a general introduction about the research and application of technology innovation in China. At the national level, one obvious fact is that the total R&D expenditure increased rapidly during the year 2001 to year 2005 and reached Y 245 billions, and China made 2,452 international patent applications in 2005 and became the world's 10th largest user of the Patent Cooperation Treaty. At the industry and enterprise level, much progress has also been made in China. This article uses the high-tech industry as an example to introduce the industry and enterprise technology innovation respectively. Corresponding to the practice, scholars also did a great amount of research work related to technology innovation. This article sums up all the work done from the macroscopic aspect (such as national technology innovation strategy, regional innovation system, industry technology innovation) and microcosmic aspect (such as enterprise technology innovation strategy, patterns and evaluation standards). Based on the analysis, this article discusses the limitation of current work and research trend about the technology innovation.

• Journal of Digital Convergence
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• v.11 no.3
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• pp.189-197
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• 2013

Weak competitive Small Business are getting attention for their ability to enhance the brand power and marketing co-brand. Under these circumstances, in this study examined the operational status of the domestic co-branded. Also enable co-branding strategy was proposed. First, learn the various aspects of the concept of co-branding, and looked at the advantages and disadvantages of co-branding. Second, the type of co-branded partner combined, joint venture between companies Union type, a leading company driven and private companies and state agencies co-branded. Looked at the type of advantages and disadvantages of each. Thirdly, we presented the current status of the important co-branded domestic. Fourth, we examined the status of the Small and Medium Business Administration supports a co-branded Examined in detail by year look at the status of support for this type of co-branded Industry Distribution and co-branded interrupted. Finally, the short-term aspects and long-term perspective on the domestic co-brand activation strategy based on these materials are presented. The results of this study is expected to be the foundation of domestic co-branded business in the future to explore the ways to improve the system of government support will help to raise.

• Journal of The Korean Association of Information Education
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• v.22 no.6
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• pp.711-721
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• 2018

The development of artificial intelligence technology and the shift to a software-driven society are raising the need for digital literacy education on how to access, understand, use, create and share new open content in a variety of sustainable open content. At this point in time, this paper defines the digital literacy as the subliteracy concept for data, tools, and device elements. It is defined as a concept that includes cognitive and non-cognitive abilities and is stratified by computer literacy, ICT literacy, and information literacy. Open content is also defined as teaching-learning materials that can be used and shared freely by anyone, such as the Open Education Resource (OER) and the Open Access movement. Based on the two definitions, a three-step strategy for digital literacy education was developed to select open content in the digital environment, followed by a digital literacy education plan, and finally, an education frame to foster digital literacy capabilities.

• Journal of the Korean Society for Library and Information Science
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• v.58 no.1
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• pp.395-415
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• 2024

In the development of a university library's collection, the concept of patron-driven acquisition refers to a collection strategy that addresses users' direct information needs. In this study, an analysis of ten years' worth of book requests by user types was conducted to understand the topic preferences for efficient collection devleopment in the university library. In collection development, identifying subject areas of users' requested books is necessary for librarians to identify key areas of collection development and establish balanced collection development policies. To identify the major subject areas for each user group, KDC (Korean Decimal Classification) subject classifications were used, and network analysis techniques were applied to investigate the relationships between book topics in detail. The analysis revealed that "social sciences" emerged as the major topic across all user groups. However, in the analysis of sub-topics, "medicine" and "psychology" were distinctively identified as the major subject areas for graduate students, setting them apart from other user groups. The result of the network analysis further indicated that undergraduate students showed unique topics such as civil service, job placement, and career, which were not observed as major topic clusters in other user groups. On the other hand, graduate students tended to concentrate on a few specialized subjects, forming distinct topic clusters in the analysis.

• Korean Institute of Interior Design Journal
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• v.21 no.2
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• pp.74-83
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• 2012

This study is an historical consideration about the modern discourse of Japanese spacial tradition driven from cultural background. The purpose of this study is to establish a cartographic map of historical progress, and to shed light on the forming of identity in Japanese traditional space design on the schizo-analytical aspect. It adopts F. Guattari's psychoanalytic theory to the structural analysis of Japanese traditional space design. The process of this study is illustrated as follows: At first, it mentions Guattari's theory of Mechanical Unconscious, Schizo-analysis, Cartography, and Abstract machine as theoretical background. And, it considers the identity of Japanese traditional space constructed by various cultural sign over a long period of time as the statement of apriority. Secondly, it clarifies semiologic generation of Japanese traditional space design based on the analysis of spacial morphemes about each design stemmed from modernization process of Japan. Thirdly, it ascertains semiologic topography the representamens draw, i.e. schizo-analytic cartography from synchronic and diachronic point of view. Fourthly, it analyses traditional discourse structure in terms of generative schizo-analysis and transformational schizo-analysis with four categories- object, style, concept, strategy. Through this process, it studies the reproduction of Japanese tradition in terms of the 'social organization', and explores the way vitalized on the space-time coordinate system by the schizo-analysis of the mechanical unconscious. In conclusion, it clarifies Generative-schizo is accomplished in the level of formulating representamen, and Transformational-Schizo involves experimental mind that induce implantation of the heteromorphic elements and avant-garde experiments of abstract mechanical operation in the schizo-analysis of Japanese traditional space design. The significance of this study is to arrange an opportunity of introspection on Korean-ness seriously from inspecting logic of Japan-ness closely in traditional space design.

• Journal of Energy Engineering
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• v.28 no.4
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• pp.103-110
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• 2019

The domestic innovative power reactor named iPOWER will employ the passive molten corium cooling system(PMCCS) to cool down and stabilize the core melt in the severe accident. The final design concept of the PMCCS is yet to be determined, but the in-vessel retention through external reactor vessel cooling has been also considered as a viable strategy to cope with the severe accident. In this study, the two-phase natural circulation flow established between the reactor vessel and the insulation was simulated using a thermal-hydraulic system code, MARS-KS. The flow path of cooling water was modeled with one-dimensional nodes, and the boundary condition of the heat load from the molten core was defined to estimate the naturally-driven flow rate. The evolution of major thermal-hydraulic parameters were also evaluated, including the temperature and the level of cooling water, the void fraction around the lower head of the reactor vessel, and the heat transfer mode on its external surface.