• Proceedings of the Korean Vacuum Society Conference
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• 2000.02a
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• pp.80-80
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• 2000

Surface acoustic wave (SAW) devices have become more important as mobile telecommunication systems need h호-frrequency, low-loss, and down-sized components. Higher-frequency SAW divices can be more sasily realized by developing new h호-SAW-velocity materials. The ZnO/diamond/Si multilasyer structure is one of the most promising material components for GHz-band SAW filters because of its SAW velocity above 10,000 m/sec. Silicon carbide is also a potential candidate material for high frequency, high power and radiation resistive electronic devices due to its superior mechanical, thermal and electronic properties. However, high price of commercialized 6- or 4H-SiC single crystalline wafer is an obstacle to apply SiC to high frequency SAW devices. In this study, single crystalline 3C-SiC thin films were grown on Si (100) by MOCVD using bis-trimethylsilymethane (BTMSM, C7H20Si7) organosilicon precursor. The 3C-SiC film properties were investigated using SEM, TEM, and high resolution XRD. The FWHM of 3C-SiC (200) peak was obtained 0.37 degree. To investigate the SAW propagation characteristics of the 3C-SiC films, SAW filters were fabricated using interdigital transducer electrodes on the top of ZnO/3C-SiC/Si(100), which were used to excite surface acoustic waves. SAW velocities were calculated from the frequency-response measurements of SAW filters. A generalized SAW mode. The hard 3C-SiC thin films stiffened Si substrate so that the velocities of fundamental and the 1st mode increased up to 5,100 m/s and 9,140 m/s, respectively.

• Journal of Preventive Medicine and Public Health
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• v.34 no.4
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• pp.363-371
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• 2001

Objectives : To assess the degree of quality improvement (QI) implementation and to identify its associated factors. Methods : A mailed questionnaire survey of the QI staffs at hospitals with 400 beds or more was conducted between September 15 and October 30, 2000. Of the 108 hospitals eligible for inclusion in our study, 79 participated, yielding a response rate of 73.1%. After excluding 12 hospitals that did not perform any QI activities, 117 responses from 67 hospitals were used in our analysis. The degree of QI implementation was measured using the Malcolm Baldrige National Quality Award Criteria (MBNQAC). Factors evaluated for association with the degree of QI implementation were cultural, technical, strategic, and structural factors of the hospitals. Results : The average 01 implementation score across the 7 dimensions of MBNQAC was 3.34 on a 5-point scale, with the highest score for the area of customer satisfaction (3.88) followed by information and analysis (3.59) and quality management (3.35). The results of regression analysis showed that hospitals with a ofter information system (p<0.05) and using scientific and systematic problem solving approach (p<0.01) tended to perform a higher degree of QI implementation. While statistically insignificant, positive associations were observed for the factors of group or developmental culture, the degree of employee empowerment, and the use of prospective strategy. Conclusions : It appears that the most important factors contributing to active implementation of QI in Korean hospitals were the use of scientific skills in decision making, and having a quality information system to produce precise and valid information.

• Journal of Preventive Medicine and Public Health
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• v.33 no.4
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• pp.495-504
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• 2000

Objectives : To examine various dimensions of consumer ratings of health care service with factor analysis and to find which factors influence the overall quality of health care service. Methods : A cross-sectional study was conducted on outpatients of a general hospital located in Sungnam City. A self-administered questionnaire was used to assess the consumer's ratings of health care service received. The response rate was 92.8% with a total of 537 persons completing the questionnaire. Factor analysis was performed on 34 items evaluating the quality of health care service. Items were grouped into 5 dimensions as a result of factor analysis and the reliability and validity of influence on patient service assessment were evaluated for each dimension. Results : The 5 dimensions were as follows, 1) physician services, 2) non-physician services, 3) process 4) facilities, and 5) cleanliness A positive correlation with the quality of health care service was found for the dimensions of non-physician services and process, while no significant correlation was found for the dimensions of physician services, facilities, and cleanliness. Conclusions : The result of this study may provide basic information for the development of future self-administered questionnaires of consumer ratings and for the evaluation of quality improvement activities in hospital outpatient settings.

• Journal of KSNVE
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• v.10 no.1
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• pp.41-48
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• 2000

Evaluation model for damage consciousness was established through the survey of 2,210 residents' consciousness on aircraft noise near Taegu Airport. There were none who replied that the level of the aircraft noise was as los as it was quiet. 77(3.5%) people replied the noise was normal, and 2,133(95.5%) people said it was noisy. As to the period of time when the aircraft noise occurred, 51%, 97%, 86%, 0.6% of the residents pointed out the morning time, the day time, the evening time, and the night time, respectively. Because of aircraft noise, 73%, 88%, 70%, 77%, 78%, and 33% of the residents felt it disturbing indoor conversation, telephoning, watching TV or listening to the ratio, reading or meditating, working, sleeping, and studying, respectively. It was examined that the bad effects of aircraft noise on the health were severe : 43% of the resident said they experienced embarrassment. 52% astonishment, 66% absence of mind, 61% heart-beating. 77% headaches, 78% earache, and 93% displeasure. For the survey of the residents' damage consciousness about aircraft noise, the level of aircraft noise was set as an objective variable, and gender, age, occupation. Education, the type of house, the structure of windows, the consciousness of settlement in the district, and the period of residence were set as explanatory variables. And the quantification theory I was applied to the analysis. The most influencing factor of the damage consciousness on aircraft noise was the education, the second occupation, the third age, the forth the consciousness of settlement, the fifth the period of residence, the sixth gender, the seventh the type of house, and the least influencing factor among them was the structure of windows. These findings will be a useful guideline when the government seeks to set up policies which will help solve the resident's noise problems near Taegu Airport.

• Journal of the Korean Society of Food Culture
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• v.15 no.2
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• pp.111-121
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• 2000

This study was to investigate the nutrition and cancer prevention knowledge, beliefs, attitudes, and self-reported dietary changes. Data were collected from 903 parents whose children were attending an elementary school, a middle school, a high school, or a junior college in Kimcheon. Thirty-seven percent of the subjects reported that they had made dietary changes for their health. Respondents reported eating more vegetables(33.1%), fruit(24.1%), whole grains(19.9%), and lower-fat meats(14.5%) and less alcohol(17.2%), high-fat meat(16.4%), fats(13.8%), smoked foods(13.8%), snacks/cake/sweets(11.7%), salty foods(9.6%), and refined grain products(6.1%). Those who did not make any dietary changes most often said the reason was that they thought their diets were already healthful and therefore there was no reason to make a change. Eighty-nine percent of the subjects agreed that diet and disease were related and 89.5% knew that diet and cancer were related, yet 8% believed there was nothing a person could do to reduce the risk of getting cancer. In response to open-ended questions about foods that either increase or decrease cancer risk, vegetables, fruit, traditional fermented foods, etceteras, and whole grains were thought to decrease risk, and burned foods, salty foods, additives, high-fat meats/fats, and alcohol were thought to increase cancer risk. In this study, education levels to be the major demographic variable and residential district had an impact on cancer prevention knowledge and attitudes. People at lower educational levels and rural residents should be targeted for education about cancer risk reduction.

• Korean Journal of Food Science and Technology
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• v.32 no.6
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• pp.1306-1312
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• 2000

This study was conducted to examine the effects of levels of flavoring materials on the sensory characteristics of chicken feet Jokpyun (Korean traditional gel type food) and to determine the optimum levels. Consumer desirability of Jokpyun flavored with different levels of black pepper and ginger was evaluated. Optimum levels of variables were obtained using response surface methodology. The levels were 0.33% and 0.1% for black pepper and ginger extract, respectively. The shelf-life of the optimized Jokpyun at $4^{\circ}C$ was determined as 6 days. Addition of powdered chicken broth in the Jokpyun preparation at the level of 1.5%(w/w) markedly increased boiled chicken flavor without resulting in undesirable properties.

• Annual Conference of KIPS
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• 2000.04a
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• pp.28-35
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• 2000

In order to acquire the precise and fast response for an analytical query, proper selection of the views to materialize in data warehouse is very crucial. In traditional algorithms, the whole relation is considered to be selected as materialized views. However, materializing the whole relation rather than a part of relation results in much worse performance in terms of time and space cost. Therefore, we present a new algorithm for selection of views to materialize using clustering method in order to improve the performance of data warehouse including this problem. In the presented algorithm, ASVMR(Algorithm for Selection of Views to Materialize using Reduced table), we first generate reduced tables in data warehouse using automatic clustering based on attribute-values density, then we consider the combination of reduced tables as materialized views instead of the combination of the original base relations. We also show the experimental results in which both time and space cost are approximately 1.8 times better than the conventional algorithms.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.7 no.5
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• pp.170-179
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• 2008

The disabled and elderly people have a wide variety of functional impairments. By disability and elderly user group definition identification of users needs and specification of emergency support system were studied. Existing technologies including location navigation and information exchange devise and communication systems were analyzed to design proper integrated system for emergency situations. There are two types of services considered in the project: assisted living services(ALS) including health and emergency needs and assisted mobility services(AMS) with transportation needs. To develop emergency support system, functional identification and requirements was studied through the analysis of existing emergency system and organization. The 4-step emergency management scheme was developed to preactive emergency service which include emergency detection identification, response and follow-up steps.

• YAKHAK HOEJI
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• v.44 no.5
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• pp.391-398
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• 2000

Leptin, the product of the ob gene, is a small peptide molecule synthesized by white adipocytes with an important role in the regulation of body fat and food intake. Based on the evidence that synthesis of leptin is regulated by female sex hormone, estrogen, this present study was investigated whether sex hormone precursor DHEA, can regulate obese gene expression in lean and genetically obese (ob/ob) mice. Antiobesity activity of DHEA was evaluated by determining body weight, food consumption, epididymal fat weight and serum levels of cholesterol and triglyceride in ICR, C57BL/6J, and ob/ob mice. The treatment of C57BL/6J lean and obese mice with a diet containing 0.3% and 0.6% DHEA resulted in lowered rates of weight gain in comparison to non-treated mice, although much greater response was found in the obese mice. All other concentrations of DHEA (0.015%, 0.06%, 0.15%, 0.3%) except the highest one(0.6%) showed no significant effects on weight gain in ICR mice. Food consumption was significantly decreased in all mice treated with 0.6% DHEA, whereas it was not decreased in ICR mice at lower concentrations than 0.6% DHEA. DHEA decreased significantly epididymal adipose tissue weight and serum triglyceride levels dose dependently in lean and obese mice. However serum cholesterol levels were decreased at lower concentrations than 0.15% DHEA and increased at concentrations of 0.3% and 0.6% DHEA in lean and obese mice. These increases in serum cholestrol levels at high concentrations of DHEA might result from the fact that DHEA has a cholesterol moiety thereby interfered the assay system. As an approach to elucidate the mechanism for antiobesity activity of DHEA, we examined mRNA levels of obese gene in the adipocyte and obese gene product (leptin) in the serum. The results showed that DHEA did not affect obese gene expression in ICR and C57BL/6J mice. Therefore, we concluded that antiobesity activity of DHEA was not modulated by obese gene expression.

• Smart Structures and Systems
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• v.23 no.5
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• pp.449-466
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• 2019

Cable-stayed bridges are attractive due to their beauty, reducing material consumption, less harm to the environment and so on, in comparison with other kinds of bridges. As a massive structure with long period and low damping (0.3 to 2%) under many dynamic loads, these bridges are susceptible to fatigue, serviceability disorder, damage or even collapse. Tuned Mass Damper (TMD) is a suitable controlling system to reduce the vibrations and prevent the threats in such bridges. In this paper, Multi Tuned Mass Damper (MTMD) system is added to the Ahvaz cable stayed Bridge in Iran, to reduce its seismic vibrations. First, the bridge is modeled in SAP2000 followed with result verification. Dead and live loads and the moving loads have been assigned to the bridge. Then the finite element model is developed in OpenSees, with the goal of running a nonlinear time-history analysis. Three far-field and three near-field earthquake records are imposed to the model after scaling to the PGA of 0.25 g, 0.4 g, 0.55 g and 0.7 g. Two MTMD systems, passive and active, with the number of TMDs from 1 to 8, are placed in specific points of the main span of bridge, adding a total mass ratio of 1 to 10% to the bridge. The parameters of the TMDs are optimized using Genetic Algorithm (GA). Also, the optimum force for active control is achieved by Fuzzy Logic Control (FLC). The results showed that the maximum displacement of the center of the bridge main span reduced 33% and 48% respectively by adding passive and active MTMD systems. The RMS of displacement reduced 37% and 47%, the velocity 36% and 42% and also the base shear in pylons, 27% and 47%, respectively by adding passive and active systems, in the best cases.