• Structural Engineering and Mechanics
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• v.14 no.3
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• pp.287-306
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• 2002

The assessment of structural performance of transfer structures under potential seismic actions is presented. Various seismic assessment methodologies are used, with particular emphasis on the accurate modelling of the higher mode effects and the potential development of a soft storey effect in the mega-columns below the transfer plate (TP) level. Those methods include response spectrum analysis (RSA), manual calculation, pushover analysis (POA) and equivalent static load analysis (ESA). The capabilities and limitations of each method are highlighted. The paper aims, firstly, to determine the appropriate seismic assessment methodology for transfer structures using these different approaches, all of which can be undertaken with the resources generally available in a design office. Secondly, the paper highlights and discusses factors influencing the response behaviour of transfer structures, and finally provides a general indication of their seismic vulnerability. The representative Hong Kong building considered in this paper utilises a structural system with coupled shear walls and moment resisting portal-frames, above and below the TP, respectively. By adopting the wind load profile stipulated in the Code of Practice on Wind Effects: Hong Kong-1983, all the structural members are sized and detailed according to the British Standards BS8110 and the current local practices. The seismic displacement demand for the structure, when built on either rock or deep soil sites, was determined in a companion paper. The lateral load-displacement characteristic of the building, determined herein from manual calculation, has indicated that the poor ductility (brittle nature) of the mega-columns, due mainly to the high level of axial pre-compression as found from the analysis, cannot be effectively alleviated solely by increasing the quantity of confinement stirrups. The interstorey drift demands at lower and upper zones caused by seismic actions are found to be substantially higher than those arising from wind loads. The mega-columns supporting the TP and the coupling beams at higher zones are identified to be the most vulnerable components under seismic actions.

• The Journal of Korean Society for School & Community Health Education
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• v.13 no.3
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• pp.113-125
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• 2012

Objectives: This study was aimed to inspect what relation there exists between the elderly's social support, self-esteem and the suicidal thinking, and examined factors influencing their suicidal ideation. Methods: For 207 old persons above 65 residing at Seoul, questionnaire survey was performed for 4 weeks. For response data, t-test and ANOVA, Pearson's Correlation Coefficient and Multiple Regression Analysis were performed using spss 18.0 program. Results: The results of analysis are like followings. 1. As for the social support according to the general characteristics, there was statistically significant difference in sex distinction, religion, living arrangement, educational level, monthly allowance and mode to use spare time. As for self-esteem according to the general characteristics, there was statistically significant difference in sex distinction, religion, living arrangement and monthly allowance. And as for the suicidal ideation, there was statistically significant difference in the marital status. 2. As for the relation between the social support, self-esteem and the suicidal ideation, it showed statistically very significant positive correlation in the social support and self-esteem. And there existed relatively higher positive correlation in family support among sub-factors of the social support and the positive self-recognition among sub-factors of self-esteem. 3. It showed that positive and negative self-recognition as sub-factors of self-esteem, others' support as sub-factor of the social support influence on the suicidal ideation. In other words, as positive self-recognition was lower, as negative self-recognition was higher, as social support of others was lower, they had much more effect on the suicidal ideation of the elderly. And it showed about 36.1% of the explanatory capability. Conclusions: Health care providers should develop school health education for the elderly.

• Journal of Korean Academy of Nursing
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• v.29 no.2
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• pp.371-382
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• 1999

Nurses are at the forefront of providing hands-on care to patients infected with HIV(Human Immunodeficiency Virus). Therefore, appropriate and sensible infection control precaution should be taken at all times. The purpose of this study is to find out nurse's loaming needs about HIV/AIDS ; and nurse's willingness to perform nursing care to HIV/AIDS patients ; and the degree of fellowing universal precautions in nursing care ; and the degree of knowledge of HIV/AIDS to provide information on the guide for the further continuing education. The respondents of this study were 280 nurses in a university hospital in Kwang-Ju city. Data were collected using a self-administered questionnaire and analyzed by using percentages, means, Pearson's correlation, t-test, ANOVA, Duncan's grouping. The findings were as follows ; 1. The mean age of the nurses was 28.9 years, and the mean duration of their clinical experience was 6.8 years. Majority of the nurses(83.9%) had no experience in taking care of the AIDS patients. 2. The content s nurse's need to learn were showed in order such as clinical manifestations, infection control, patient care, and the mode of transmission of HIV/AIDS. 3. Even though the nurses had quite low knowledge about HIV/AIDS(mean score was 12.2 from the total of 26), they are willing to take care of the AIDS patients (mean score was 39.5 from the total of 60), and the degree of following universal precaution was also not so bad (mean score was 40.8 from the total of 50). 4. Nurses who are over 35 years old and had informal education regarding HIV/AIDS better following universal precautions. Nurses who had over 12 years of clinical experiences have more willingness to perform nursing care to the AIDS patients. Nurses who had experiences in taking care of the AIDS patients were more knowledgeable about HIV/AIDS. These findings suggest that some strategies should be develope to increase the willingness to perform the nursing care to the AIDS patients. And also continuing education program should be develope and run for the clinical nurses so that they can provide effective and appropriate nursing care to the AIDS patients.

• Journal of the Korea Organic Resources Recycling Association
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• v.23 no.1
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• pp.38-44
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• 2015

We have investigated the productivity of microalgae, Nannochloropsis sp., using highly efficient vertical photobioreactor which has been developed by the company IMBiz. This experiment was performed in the field for one month with 2 sets of 2 tons of media under autotrophic cultural mode. In the culture with 0.1% of $CO_2$, the average daily productivity was shown to be up to 0.953g per liter, and 0.574g per liter in the culture with only ambient air. The temperature ranged from $20^{\circ}C$ to $31^{\circ}C$, and it didn't make any differences on the productivity. The light intensity ranged from 5,000 Lux to 40,000 Lux. The light has been appeared to have a very close relationship with the productivity of microalgae. Meanwhile, the harvesting method of pressurefloating attempted in this photobioreactor was found to be very effective.

• Journal of Korean Library and Information Science Society
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• v.31 no.1
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• pp.87-114
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• 2000

The purpose of this study is offering appropriate system and training program to helf the system designer and the trainer in addition to analyze information use behavior about the web search tools and evaluate the estimated system by user groups. The results of the study are as follows $\circledS1$ It is desirable to consider age than other demographic variables in the case of web search tool. $\circledS2$ It is desirable to design Directory Search Tool in the case of web search tool which serves the student user group. $\circledS3$ An Intelligent Search Tool is more appropriate for the students who are using keyword search tool than any other tools. $\circledS4$ A discussion about standard classification of the web information should be accomplished soon because users feel confused in using web search tools due t o absence of standard mode of classification about classified item. $\circledS5$ Librarians need the cognition about data on internet s a source of information and need positive service and user training program about these information because student users hardly get help from librarians or library orientation for learning method to use web search tool. $\circledS6$ Internet use experience and years of computer use had effect on their use ability when using web search tool, whereas computer use experience, library use experience and Online Public Access Catalogs (OPAC) use experience had no effect on it. Especially, OPAC use experience had no effect on use ability of web search tool of student user group because student user groups had no information about internet and web search tool and they did not recognized the difference about search method between web search tool and OPAC. $\circledS7$In the case of web search tool, it si important to index the increasing web resource automatically by a searching robot. But in the case of student users, web search tool is much more needed to index by index expert due to the absence of ability about selecting and combining keyword.

• Journal of Power System Engineering
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• v.9 no.2
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• pp.81-87
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• 2005

This study is numerical analysis on the increasing temperature characteristics of vaporizer fin for liquefied natural gas with super low temperature. Existing LNG vaporizers use the direct contact heat transfer mode where the extreme super low temperature LNG of $-162^{\circ}C$ flows inside of the tubes and about $20^{\circ}C$air flows on outside of the fin. Recently, the vaporizers with great enhanced performance compared to conventional type have been developed to fulfill these requirements. The vaporizing characteristic of LNG vaporizer with air as heat source has a fixed iced. These characteristic cause a low efficiency in vaporizer, total plant cost and installing space can be increased. The vaporizing characteristics of LNG via heat exchanger with air are analytically studied for an air heating type vaporizer. This study is intended to supply the design data for the domestic fabrication of the thickness and angle vaporizer fin. Governing conservation equations for mass, momentum and energy are solved by STAR-CD based on an finite volume method and SIMPLE algorithm. Calculation parameter is fin thickness, setup angle and LNG temperature. If the vaporization performance of the early stage and late stage of operating is considered, the case of ${\phi}=90^{\circ}$ was very suitable. In this paper was estimated that the heat transfer was most promoted in case of THF=2mm.

• Journal of Korean Society of Transportation
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• v.23 no.8 s.86
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• pp.43-51
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• 2005

Thomson(1977) proposed that the equilibrium status can exist among modes when each mode's attractivenesses' are equal. His theories key point is that when the equilibrium status is achieved the additional investment for individual car user such as constructing more roads or widening the existing roads, can lead to more congestion. That's the so called 'Downs-Thomson's Paradox. This paper is intended to demonstrate that the paradox is applicable to Seoul Metropolitan area. Before doing that job, we reviewed Downs-Thomson's paradoxes related Papers such as Mogridge's (1985) research for London case. and Seung Jea-Lee's(2004) research for Seoul. In conclusion, the equilibrium status that Thomson proposed can't be applied to Seoul Metropolitan area. because the suppressed demand's behaviour is different from real situation and that of in the theory.

• Journal of The Korean Astronomical Society
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• v.36 no.spc1
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• pp.75-81
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• 2003

Changes in the earth's climate depend on changes in the net sunlight reaching us. The net depends on the sun's output and earth's reflectance, or albedo. Here we develop the limits on the changes in the sun's output in historical times based on the physics of the origin of solar cycle changes. Many have suggested that the sun's output could have been $0.5\%$ less during the Maunder minimum, whereas the variation over the solar cycle is only about $0.1\%$. The frequencies of solar oscillations (f- and p-modes) evolve through the solar cycle, and provide the most exact measure of the cycle-dependent changes in the sun. But precisely what are they probing? The changes in the sun's output, structure and oscillation frequencies are driven by some combination of changes in the magnetic field, thermal structure and velocity field. It has been unclear what is the precise combination of the three. One way or another, this thorny issue rests on an understanding of the response of the solar structure to increased magnetic field, but this is complicated. Thus, we do not understand the origin of the sun's irradiance increase with increasing magnetic activity. Until recently, it seemed that an unphysically large magnetic field change was required to account for the frequency evolution during the cycle. However, the problem seems to have been solved (Dziembowski, Goode & Schou 2001) using f-mode data on size variations of the sun. From this and the work of Dziembowski & Goode (2003), we suggest that in historical times the sun couldn't be much dimmer than it is at activity minimum.

• The Korean Journal of Ceramics
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• v.2 no.4
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• pp.216-220
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• 1996

In the present paper, a new type of DC arc plasma torch is disclosed. The principles of the new magnetic and fluid dynamic controlled large orifice long discharge tunnel plasma torch is discussed. Two series of DC Plasma Jet diamond film deposition equipment have been developed. The 20kW Jet equipped with a $\Phi$70 mm orifice torch is capable of deposition diamond films at a growth rate as high as 40$\mu\textrm{m}$/h over a substrate area of $\Phi$65 mm. The 100kW high power Jet which is newly developed based on the experience of the low power model is equipped with a $\Phi$120 mm orifice torch, and is capable of depositing diamond films over a substrate area of $\Phi$110 mm at growth rate as high as 40 $\mu\textrm{m}$/h, and can be operated at gas recycling mode, which allows 95% of the gases be recycled. It is demonstrated that the new type DC plasma torch can be easily scaled up to even higher power Jet. It is estimated that even by the 100kW Jet, the cost for tool grade diamond films can be as low as less than ＄4/carat.

• Aerospace Engineering and Technology
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• v.6 no.1
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• pp.128-135
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• 2007

Combustion characteristics of full-scale gas generators were studied experimentally by changing the injector number installed at the injector head. Three full-scale gas generators were utilized; they have same total mass flow rate but mass flow rates per injector are different. Thirteen, nineteen and thirty seven injectors, which have internal-mixing and double-swirl characteristics, are distributed in injector heads, respectively. The results showed that pressure fluctuations in the gas generators with 13 and 19 injectors didn't occur around longitudinal resonant frequency, however longitudinal-mode pressure fluctuation appeared slightly in the gas generator with 37 injectors. As the number of injectors increased, deviations of temperature distribution in the combustion chamber decreased gradually, but the damage of injector LOx posts became a little severe.