• 한국신재생에너지학회:학술대회논문집
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• 2006.06a
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• pp.415-418
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• 2006

In Japan, research and development were undertaken on gas hydrate-side industrial processes associated with power generation system connections that may particularly be necessary to develop gas hydrated technology-based industrial systems. In so doing, data and engineering technologies useful n formulating guidelines on design of practical process were accumulated. In addition, basic research into theoretical evidence were carried out to promote and support the development of technological elements for those processes. In basic research designed to promote and support the research and development of elemental technologies microanalyses were conducted to understand the decomposition mechanism of mixed gas hydrate. Moreover, measurement technologies that can be applied in industrial processes, such as numerical analyses and concentration ion measurement, were examined. Japan has developed a highly efficient gas hydrate formation process using micro-bubbles with a tubular reactor. Higher formation rate over conventional systems has been obtained by the process. As mentioned above, the technical problems were clarified and the economics were studied from a view point of the NGH technology in this study. The results can be applied for utilization and must contribute to popularization of gas hydrate production.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.18 no.1
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• pp.94-100
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• 2008

Noise barriers are being used more often to solve problems of noise pollution from traffic noise. Several types of noise barriers are being installed to increase the cost-effectiveness of noise barrier installation. In this study, the insertion loss is analyzed to evaluate the effectiveness of the noise barrier by using the BEM. In order to check the validity of the BEM, the BEM and Lam's theoretical analysis are compared with measurement, which is performed in the anechoic chamber for the 1/10 scale-down model, and good agreements are obtained. By using the two dimensional boundary element method, the insertion loss is calculated and analyzed for several typical noise barriers such as the vertical barrier, the barrier with an oblique edge on top, the T-shaped barrier and the barrier with interference device on top. With these analyses, it is possible to design more cost-effective noise barriers appropriate for a particular area.

• Journal of the Korean Society of Industry Convergence
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• v.13 no.3
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• pp.153-160
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• 2010

This study analyzes the difference of perspectives between companies and students for tax science education in order to present plans to enhance the efficiencies of tax science education. Analyses were made on a total of 93 subjects composed of companies and seniors majoring in tax science at the department of taxation in K University. After analyzing the perspectives on the need for the current curriculum, there was no difference in the overall average between companies and students. For the need for revising the education course, there was a difference in perspective between the two groups at about 1%. There was no difference between the groups for perception on theoretical, lab and on-site experience education, but there was a high difference from the current education course for its perception level. For certification instructions there was a noticeable difference between companies and students at about 1%, and companies responded that guidance on computerized taxation accounting was needed, while students stated that they needed guidance on financial administrator certification. In brief, the significance of this study is that it shows that in order to enhance the efficiency of education on tax sciences, the rapidly changing educational environment must be reflected, and the demands of companies and students.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.9
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• pp.3056-3074
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• 2014

Convergecast is probably the most common communication style in wireless sensor networks (WSNs). And linear network coding (LNC) is a promising concept to improve throughput or reliability of convergecast. Most of the existing works have mainly focused on exploiting these benefits without considering its potential adverse effect. In this paper, we argue that LNC may not always benefit convergecast. This viewpoint is discussed within four basic scenarios: LNC-aided and none-LNC convergecast schemes with and without automatic repeat request (ARQ) mechanisms. The most concerned performance metrics, including packet collection rate, energy consumption, energy consumption balance and end-to-end delay, are investigated. Theoretical analyses and simulation results show that the way LNC operates, i.e., conscious overhearing and the prerequisite of successfully decoding, could naturally diminish its advantages in convergecast. And LNC-aided convergecast schemes may even be inferior to none-LNC ones when the wireless link delivery ratio is high enough. The conclusion drawn in this paper casts a new light on how to effectively apply LNC to practical WSNs.

• Journal of the Korean Society for Library and Information Science
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• v.22
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• pp.83-107
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• 1992

The Purpose of this paper is to suggest directions for the future education of Library management. For this purpose, some theoretical backgrounds are traced based on the historical events, the standards provided by international and national organizations, and theories suggested through researches. And the percentages of library management subjects in the curricula of ten Library and Information Science Departments are calculated divided by compulsory and elective ones, along with the contents analyses of a few textbooks in the field. The hypotheses to be tested are as follows: 1. The American postgraduate library education was introduced into Korea as an undergraduate course. So the importance of the subject of library management was recognized as in America, and the numbers of subject Would have been increased, and the contents detailed. 2. The contents of the subject taught would not have changed much since its introduction. It means that they will be almost the same as those were prevalent in the United States of America in the 1950s, when the American education was brought into Korea. The hypotheses can be accepted as being true. Based on the conclusions, some suggestions, including the teaching of the subject should be directed more towards management aspects rather than administrative ones, are provided.

• The Korean Journal of Health Service Management
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• v.13 no.4
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• pp.53-65
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• 2019

Objectives: This study analyzed the influence of the career plateau phenomenon and distributive justice among hospital nurses on their turnover intention and the moderating effect of proactivity on these correlations. Methods: Survey data from 459 out of 500 hospital nurses at 9 hospitals were collected and used for analysis. SPSS 24.0 was used for conducting regression, validity, and reliability analyses. Results: Career plateau was positively related to turnover intention, whereas distributive justice was negatively related to turnover intention. Proactivity strengthened the positive influence of career plateau on turnover intention. By contrast, proactivity alleviated the negative relation between distributive justice and turnover intention. Conclusions: This study empirically confirmed that career plateau and distributive justice are important antecedent factors of the turnover intention of hospital nurses. Proactivity played a key moderating role between these antecedent factors and turnover intention. Theoretical and practical implications of this study were also discussed.

• Structural Engineering and Mechanics
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• v.76 no.3
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• pp.367-378
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• 2020

This paper presents a new design concept for ocean nuclear power plants (ONPPs) using a tension leg platform (TLP). The system-integrated modular advanced reactor, which is one of the successful small modular reactors, is mounted for demonstration. The authors define the design requirements and parameters, modularize and rearrange the nuclear and other facilities, and propose a new total general arrangement. The most fundamental level of design results for the platform and tendon system are provided, and the construction procedure and safety features are discussed. The integrated passive safety system developed for the gravity based structure-type ONPP is also available in the TLP-type ONPP with minor modifications. The safety system fully utilizes the benefits of the ocean environment, and enhances the safety features of the proposed concept. For the verification of the design concept, hydrodynamic analyses are performed using the commercial software ANSYS AQWA with the Pierson-Moskowitz and JONSWAP wave spectra that represent various ocean environments and the results are discussed.

• Journal of the Society of Naval Architects of Korea
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• v.30 no.3
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• pp.1-15
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• 1993

In response to the growing domestic request and the change of the overseas environment, Hyundai Maritime Research Institute has recently established a three-stage development plan for the high speed marine transportation system. As the first stage plan, the long-range high-speed foil catamaran passenger ship has been designed and constructed for the open-sea serivice of 800 nautical miles round trip with top speed above 40 knots. Extensive theoretical analyses and model tests were systematically carried omit along the course of design for the system optimization and the verification. In this paper, the brief summary of the design and the construction works shall be presented.

• Journal of the Society of Naval Architects of Korea
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• v.42 no.5 s.143
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• pp.528-533
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• 2005

A mono-static high frequency acoustic target strength analysis scheme was developed for underwater targets, based on the far-field Kirchhoff approximation. Au adaptive triangular beam method and a concept of virtual surface were adopted for considering the effect of hidden surfaces and multiple reflections of an underwater target, respectively. A test of a simple target showed that the suggested hidden surface removal scheme is valid. Then some numerical analyses, for several underwater targets, were carried out; (1) for several simple underwater targets, like sphere, square plate, cylinder, trihedral corner reflector, and (2) for a generic submarine model, The former was exactly coincident with the theoretical results including beam patterns versus azimuth angles, and the latter suggested that multiple reflections have to be considered to estimate more accurate target strength of underwater targets.

• International Journal of Naval Architecture and Ocean Engineering
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• v.4 no.1
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• pp.20-32
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• 2012

A software system for a complex object scattering analysis, named SYSCOS, has been developed for a systematic radar cross section (RCS) analysis and reduction design. The system is based on the high frequency analysis methods of physical optics, geometrical optics, and physical theory of diffraction, which are suitable for RCS analysis of electromagnetically large and complex targets as like naval ships. In addition, a direct scattering center analysis function has been included, which gives relatively simple and intuitive way to discriminate problem areas in design stage when comparing with conventional image-based approaches. In this paper, the theoretical background and the organization of the SYSCOS system are presented. To verify its accuracy and to demonstrate its applicability, numerical analyses for a square plate, a sphere and a cylinder, a weapon system and a virtual naval ship have been carried out, of which results have been compared with analytic solutions and those obtained by the other existing software.