• Journal of Power System Engineering
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• v.14 no.3
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• pp.19-24
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• 2010

The purpose of this study is to develop a snow melting system using the pulsating heat pipe(PHP). The experimental apparatus is consisted of a PHP, a concrete structure, a constant water thermostatic bath and a flowmeter. The experiment was performed at the outdoor air temperature of $-8^{\circ}C$ and inlet temperature of hot water of $75^{\circ}C$. PHP is the closed and non-loop type heat exchanger which is charging R-410A as an operating fluid. As experimental results, the temperature profile of vertical and horizontal orientation of concrete structure was measured with operating time. The heat flux of the snow melting was required more than 300 $W/m^2$. We confirmed that the snow melting system using the PHP was useful for anti-freezing road.

• Research in Community and Public Health Nursing
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• v.17 no.1
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• pp.65-73
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• 2006

Purpose: The purpose of this study was to identify the correlation between the feeling of powerlessness, social support and life satisfaction in the elderly. Methods: The subjects were 158 old people aged over 65 who were attending one of one college and three settlement houses for senior citizens located in B city. Results: The relationship between the feeling of powerlessness and life satisfaction was in a moderate negative correlation with each other (r=-.433, p=.000). The relationship between social support and life satisfaction was in a moderate positive correlation with each other (r=.410, p=.000). It was found that the higher social support was, the higher life satisfaction was. There was remarkable difference in the form of family (F=2.69, p=.023), the form of residence (F=5.29, p=.002), whether to belong to a group (F=2.26, p=.025). Conclusion: For the reasons stated above, as the feeling of powerlessness is lower and social support is higher, life satisfaction is higher. The results clearly show that in order to improve life satisfaction of the elderly, we need to ease their feeling of powerlessness and enhance social support to them. Therefore, it is necessary to develop a nursing intervention program to reduce powerlessness and to improve social support for the elderly.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.13 no.3
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• pp.447-456
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• 2006

Purpose: This study was done to examine symptom experiences and related factors in angina patients. Method: The participants were 92 patients admitted to C university hospital between October and December 2004. The tools used were a questionnaire on symptom experience related to angina developed by Gensini(Coronary Angiographic Gensini Score). Global Assessment of Recent Stress Scale and a tool measuring performance of health behavior. Results: The mean score for symptom experience was relatively low (M=27.65, SD=18.44) as was the score for coronary severity (Gensini score) was 16.30 point (SD=18.04). The mean score for perceived stress was moderate (M=30.16, SD=12.26). Compliance was relatively good in these patients with angina (M=61.55, SD=7.60). Analysis of the correlation of symptom experience showed a statistically significant positive relationship with perceived stress (r=.410, p=.000). There was significant negative relationship (r=-.251, p=.016) between symptom experience and compliance. In the regression analysis, symptom experience was found to be significantly influenced by stress ($R^2$=.168, p=.000), age ($R^2$=.057, p=.002), and economic status ($R^2$=.061, p=.007). These variables explained 26.2% of the variance in symptom experience. Conclusion: The results of this study provide evidence that symptoms of angina can present not only as chest pain itself but also with fatigue, shortness of breath, and sleep disturbance as the most common symptoms.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.3
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• pp.410-416
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• 2010

Methane emitted from ruminant livestock is regarded as a loss of feed energy and also a contributor to global warming. Methane is synthesized in the rumen as one of the hydrogen sink products that are unavoidable for efficient succession of anaerobic microbial fermentation. Various attempts have been made to reduce methane emission, mainly through rumen microbial manipulation, by the use of agents including chemicals, antibiotics and natural products such as oils, fatty acids and plant extracts. A newer approach is the development of vaccines against methanogenic bacteria. While ionophore antibiotics have been widely used due to their efficacy and affordable prices, the use of alternative natural materials is becoming more attractive due to health concerns regarding antibiotics. An important feature of a natural material that constitutes a possible alternative methane inhibitor is that the material does not reduce feed intake or digestibility but does enhance propionate that is the major hydrogen sink alternative to methane. Some implications of these approaches, as well as an introduction to antibiotic-alternative natural materials and novel approaches, are provided.

• Steel and Composite Structures
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• v.2 no.5
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• pp.397-410
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• 2002

The main aim of the present paper is to present the results of a full-scale experimental investigation to study the structural behaviour of composite steel beams. The composite beam was made of cold-formed steel section shapes filled with reinforced concrete. First a comprehensive description of the experimental results in terms of: deflections, deformations, slippage and stress levels on critical steps of the load path is presented. The experimental results were then compared to theoretical values obtained by the use of an analytical model based on ultimate limit state stress blocks. Finally, a practical application of the use of this structural solution is depicted.

• 유체기계공업학회:학술대회논문집
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• 2001.11a
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• pp.404-410
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• 2001

A new thermal type fluid level transmitter was designed and tested at the HITROL R&D institute. The relation of heat transfer and electric resistance was adopted as an operation principle. The length of a fabricated level transmitter was two meters and a water under normal temperature was used as a working fluid for the experiment Finally, the new product could have a high precision, acceptable accuracy and reasonable response time. Foreign-made level transmitter of this type is under in use for measuring water level of containment building in nuclear power plants so far. It is expected that new product will substitute it.

• Journal of Photoscience
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• v.9 no.1
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• pp.23-28
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• 2002

In order to obtain thermal-stable, low birefringent, and low optical loss waveguiding materials, we synthesized several fluorinated poly (maleimide-co-glycidylmethacrylate)s using a pentafluorophenylmaleimide (PEM) and two kinds of methacrylate derivatives as comonomers and glycidylmethacrylate as a crosslinker. One comonomer is a linear fluorinated methacrylate (HFBM) and another is a bulky norbornane-derived methacrylate (NMMA). These copolymers could be self-crosslinked by heating due to epoxy groups of glycidylmethacrylates. As a maleimide contents increased to 50 mol%, these copolymers showed high decomposition temperatures of above 300$^{\circ}C$. The refractive index could be precisely controlled by the variation of PFM/HFBA or PFM/NMMA feed ratio in the range of 1.410∼1.508 at 643 nm. The copolymers had very low birefringence in the range of 1∼5${\times}$10$\^$-4/.

• Proceedings of the KOSOMBE Conference
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• v.1997 no.11
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• pp.407-410
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• 1997

In this paper, we have designed a portable patient monitor that monitors both ECG and NIBP(Non-Invasive Blood Pressure) for a patient who is bring moved around inside a hospital. System hardware consists of the one-chip microcomputer(80c251), A/D converter, ROM, RAM, LCD diplsy, two channel ECG module and NIBP module. NIBP module was calibrated to the values found in NIBP analyzer. ECG module detects QRS complex and compute heart rate. NIBP module measures the blood pressure by oscilometric method.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1998.06a
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• pp.410-412
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• 1998

Subsymbolic Knowledge processing is said to be changed states of networks constructed from small elements. subsymbolic systems also make it possible to use connectionist models for knowledge processing. Connectionist realization such modulus are modulus linked together for solving a given problem. We study using neural networks as distinct actions. The output vectors produced by the neural networks are consider as a new facts. These new facts are then processed to activate another networks or used in the current production rule, The production rule is applying knowledge stored in the knowledge base to make inference. After neural networks knowledge base is constructed and trained. We present a running sample of incorporating neural network knowledge base. We implement using rochester connectionist simulator. We suggest that incorporating neural network knowledge base. Therefore incorporated neural network knowledge base ensures a cleaner solution which results in better perfor s.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.11 no.1
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• pp.15-20
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• 2015

In this study, the optimization and performance characteristics of a cascade heat pump system was analyzed with the variation of low stage refrigerant charge amount. The cascade heat pump was designed and constructed with R134a and R410A as the refrigerant for high stage and low stage cycle, respectively. Experiments were conducted by varying the low stage charge amount and the performance characteristics of the cascade heat pump were studied. The refrigerant charge amount of the low stage cycle was varied between the ranges of -15% and +10% of the optimum charge amount. The performance variation experienced in the cascade heat pump due to the variation of refrigerant charge amount shows greater effect in the undercharge regions than the overcharge regions. COP reduction in the undercharge region is larger than the decrease in the overcharge region. Some cycle variation such as power consumption and cycle pressure according to low stage refrigerant charge amount showed different trends comparing with those according to high stage refrrgerant charge amount. Therefore, the optimum charge amount of the cascade heat pump should be determined based on the experimental data obtained by the variation of high and low stage refrigerant charge amount.