• Quality Improvement in Health Care
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• v.8 no.1
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• pp.10-21
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• 2001

Background : The Clostridium difficile is the most important identifiable cause of nosocomial infectious diarrhea and colitis, which lengthens hospital stay. Recently incidence of C. difficile has been increasing in an university hospital, and an intervention for prevention and control of C. difficile associated diarrhea (CDAD) was in prompt need. Methods : Subjects were the patients in the neurosurgical intensive care unit(NCU) where C. difficile was most frequently isolated. To increase participation of various departments, we used the CQI method, because management of CDAD requires a wholistic approach including control of antibiotics, barrier precaution and environmental cleaning and disinfection. Duration of the CQI activities was 9 months from April to December 1999. Results : The identified problems were misuse and overuse of antibiotics, lack of consciousness of medical personnels and the possibility of transmission from the contaminated environment and tube feeding. Education for proper use of antibiotics and management of C. difficile infection, use of precaution stickers, supplement of handwashing equipments, emphasis on environmental disinfection, and the change of the process of tube feeding were done. The CDAD rate in NCU was significantly decreased after the CQI program (8.6 case per 1,000 patient days from January to April 1999 vs 4.8 from May to December 1999). The distribution of neurosurgical wards including NCU among the total number of isolated C. difficile from the clinical specimens dropped from 49.4% in January to April to 33,7% in May to December. The average hospital stay of the neurosurgical department changed from 19.6 days to 15.2 days. Also, the effect of the CQI activities for C. difficile may have affected the incidence of vancomycin resistant enterococci (VRE). Duration and dosage of certain antibiotics used in the NS department were decreased. The distribution of neurosurgical department in the number of VRE isolated patients declined from 18.4% to 11.1%. Conclusion : Infection control of resistant organisms such as C. difficile is likely to be successful when management of environmental contamination an collaborative efforts of decreasing the patients' risk factors such as antibiotics management and decreasing the length of hospital stay come simultaneously. For this work, related departments need to actively participate in the entire process under a common target through discussions for identifying problems and bringing up solutions. In this respect, making use of a CQI team is an efficient method of infection control for gathering participation and cooperation of related departments.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2002.09a
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• pp.314-317
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• 2002

The purpose of this study was to evaluate the clinical application of Patlak tool on GE PET workstation for quantitative analysis of dynamic PET images in cardiac patients. Three patients including coronary artery disease (CAD), myocardial infarction (MI), and angina were studied. All subjects underwent dynamic cardiac PET scan using a GE Advance scanner. After 10 min transmission scan for attenuation correction using two rotating $\^$68/Ge rod sources, three patients with cardiac disease were performed dynamic cardiac PET scan after the administration of approximately 370 MBq of FDG. The dynamic scan consisted of 36 frames with variable frame length (12${\times}$10s, 6${\times}$20s, 6${\times}$60s, 12${\times}$300s) for a total time of 70 min. Blood samples were obtained to determine the plasma substrate concentration. Region of interest of circular and rectangular shape to acquire input functions and tissue data were placed on left ventricle and myocardium. A value of 0.67 was used for lumped constant. Mean plasma substrate concentrations for three patients were 100 mg/dl (CAD), 100 mg/dl (MI), 132 mg/dl (angina), respectively. Regional MMRGlc values (mean${\pm}$SD) at lateral myocardium area for CAD, MI, and angina were 8.43${\pm}$0.24, 4.08${\pm}$0.16, and 6.15${\pm}$0.23 mg/min/100ml, respectively. Patlak tool on GE PET workstation appeared to be useful for quantitative analysis of dynamic PET images in cardiac patients, although further studies may be required for absolute quantitation.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.25 no.2
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• pp.156-163
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• 2014

In this paper, a compact circularly polarized metamaterial patch antenna using cross aperture-coupled feed is proposed. The CP antenna utilizes the -1 mode that is induced by the composit right-left handed(CRLH) transmission line. Since the -1 mode has the same properties with the $TM_{010}$ mode of the conventional patch antenna, the circular polarization(CP) can be realized. If two orthogonal modes are excited with $90^{\circ}$ phase difference, the CP property can be obtained. In order to obtain two orthogonal modes and $90^{\circ}$ phase difference, 4 mushroom structures having the shape of square are employed. The width and length of the cross aperture are optimized through the design algorithm. The fabricated antenna is based on RT/duroid5880 substrate and the total area of the 4 mushroom is $0.25{\lambda}_0{\times}0.25{\lambda}_0$. The center frequency of the LHCP(Left-Handed Circular Polarization) antenna is measured as 1.622 GHz and circular polarization bandwidth(3 dB) is measured as 3 MHz. The center frequency of the RHCP(Right-Handed Circular Polarization) antenna is measured as 1.609 GHz and circular polarization bandwidth (3 dB) is measured as 3 MHz, respectively. The measured radiation efficiency of LHCP antenna is 61.1 % and the measured radiation efficiency of RHCP antenna is 54.5 %.

• Journal of Korea Multimedia Society
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• v.11 no.7
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• pp.1007-1015
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• 2008

In order to provide real-time data from sensors and instruments at manufacturing processes on web, we proposed a communication service model based on XML(eXtensible Markup Language). HTML(Hyper Text Markup Language) is inadequate for describing real-time data from manufacturing plants while it is suitable for display of non-real-time multimedia data on web. For applying XML-based web service of process data in Intranet environment, real-time performance of communication services was evaluated to provide the system design criteria. XML schema for the data presentation was proposed and its communication performance was evaluated by simulation in terms of transmission delay due to increased message length and processing delay for transformation of raw data into defined format. For transformation of raw data into XML format, we proposed two structures: one is the scheme where transformation is done at an SCC(Supervisory Control Computer) after receiving real-time data from instruments. the other is the scheme where transformation is carried out at instruments before the data are transmitted to the SCC. Performances of two structures were evaluated on a testbed under various conditions such as six packet sizes and offered loads of 20%, 50% and 80%, respectively. Test results show that proposed schemes are applicable to the systems in Ethernet 100BaseT network if total message traffic is less than 7 Mbps.