• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.2
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• pp.237-243
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• 2008

This paper presents the backplane effects for two-wire transmission line with different line length crossing the rectangular aperture in an infinite ground backplane. The FDTD method is used to determine the characteristics of the backplane insertion loss and return loss of the transmission line in accordance with the transmission line spacing and additional wire lengths. The results show that the insertion gain is obtained for the narrow spacing of the transmission line and the insertion loss is appeared for the transmission line with the additional wire The measurements of return loss are performed to verify the theoretical analysis.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.12
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• pp.2518-2524
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• 2009

This paper presents the backplane effects due to a rectangular aperture size for two-wire transmission line with equal line length crossing the changeable rectangular aperture in an infinite ground backplane. It is used to determine the characteristics of the backplane insertion loss of the transmission line from the load section in accordance with the backplane aperture size. The results show that the insertion gain and insertion loss are obtained for the specific frequency range when the transmission line is closed to the backplane aperture size. The insertion loss is decreased that the aperture horizontal length and vertical length is more than a=50 mm and b=20 mm. The measurements of insertion loss are performed to verify the theoretical analysis.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.22 no.7
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• pp.675-682
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• 2011

This paper presents two ground plane effects due to the size of two rectangular apertures for two-wire transmission line with equal line length crossing the changeable rectangular apertures in infinite ground planes. The CST MWS is used to determine the characteristics of the insertion loss of the transmission line from the load section in accordance with the ground plane aperture size. The results show that the insertion gain and the insertion loss are periodically observed for the multiple frequency of the half wavelength resonance by the wire length when the transmission line is nearby to horizontal side or vertical side of the aperture. The measurements of the insertion loss are performed to verify the theoretical analysis.

• Journal of Korean Institute of Industrial Engineers
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• v.20 no.4
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• pp.5-21
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• 1994

We have described the optimal process route selection model for the PCB(printed circuit board) auto-insertion line. This PCB assembly line is known as a FFL(flexible flow line) which produces a range of products keeping the flow shop properties. Under FFL environments, we have emphasized the balancing of work-loads in order to maximize total productivity of PCB auto-insertion line. So we have developed a heuristic algorithm based on a work-order selection rule and min-max concept for the job route selection model.

• Proceedings of the KIEE Conference
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• 2002.11b
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• pp.141-144
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• 2002

This paper describes the correction of the protective relay equipped in the dedicated line used for connecting distributed generators (DG) to power grid. The fault current measured in a relaying point might be changed according to the fault conditions. Generally, the fault current of the line to line fault or the line to ground fault at the dedicated line is much higher than the protective set value due to the large fault level. However. when the high impedance fault is occurred in the dedicated line, we may not detect it because its fault level can be lower than the generating capacity of DG. And, the protective relay with conventional set value may generate a trip signal for insertion of DG due to the large transient characteristics of generators. Through the various simulations such as the fault in the dedicated line and the insertion of DG, we show that it would be necessary to modify the protective relay set value for detecting the high impedance fault occurred in the dedicated line and for preventing the mis-operation of protective relay caused by the insertion of DG.

• IE interfaces
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• v.8 no.3
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• pp.259-267
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• 1995

A printed circuit board auto-insertion line consists of several processes of identical machines and produces several different types of PCBs. Each board must be processed by at most one machine in each process. So, we call it a flexible flow line. The load balancing is the one of the most important issues in the FFL which has many sequential processes. Therefore we have represented the job route selection model to balance the load of inter-process in the PCB auto-insertion line, and validated it by simulation.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.15 no.3
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• pp.301-310
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• 2004

In this paper, a compact dual-mode filter structure without coupling gaps is proposed. The novel design is achieved by embedding a pair of equal crossed slots and spur-lines. Without coupling gaps between feed lines and patch resonator, the new filter can provide low insertion loss. It is found that this design has wide coupling range for dual-mode operation. It means that these characteristics of the proposed filter can reduce uncertainty in fabrication. By using two PIN diodes mounted inside a pair of spur-lines, the proposed structure works as a switchable filter. Also, it has a size reduction of about 34.7 %, compared with conventional dual-mode filters.

• Clinical and Experimental Pediatrics
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• v.51 no.10
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• pp.1058-1064
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• 2008

Purpose : This study aimed to assess current knowledge of and training experiences with the intraosseous (IO) line among emergency medicine (EM) and pediatric residents who care for critically ill children and to evaluate the educational effectiveness of the IO line workshop. Methods : During May and June 2008, a workshops on IO line insertion was held for EM and pediatric residents. The workshop comprised a 45-min lecture and a 15-min hands-on session. A semi-drill type EZ-IO machine was used for education. Self-assessment questionnaires gauged residents knowledge of and experiences with IO line insertion or bone marrow (BM) examination and their confidence with IO line insertion before and after the workshop. Performance tests were completed for skill evaluation. Results : Forty-five pediatric residents and 22 EM residents participated in the workshop. The pre-educational questionnaire revealed that EM residents had more educational experience in IO line insertion than pediatric residents (P<0.001), while pediatric residents reported more experience in BM examination (P<0.001). The post-educational questionnaire showed a statistically significant higher percentage of correct answers (P<0.001). Although the pediatric residents inserted an IO line more quickly (P=0.001), most residents (88.7%) succeeded in IO line insertion on their first attempt; there was no difference in the groups success rates. Both groups showed higher confidence in performing IO line insertion after training (P<0.001). Conclusion : Observed educational effectiveness in both knowledge and confidence of IO line insertion skill suggest educational opportunities for pediatric and EM residents should be increased.

• Journal of Korean Academy of Nursing
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• v.50 no.4
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• pp.541-553
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• 2020

Purpose: In spite of the recent application of a general infection control method, central line-associated infections is still relatively high in Korea. Central line bundle with Chlorhexidine gluconate (CHG) tegaderm dressing was reported to be effective in reducing catheter colonization and central line-associated bloodstream infections (CLABSI). Therefore, this study aimed to examine the incidences of catheter colonization occurrence and CLABSI while using Tegaderm vs. CHG Tegaderm dressings. Methods: We used a descriptive design. 400 patients who had central venous catheters were selected from four hospitals in the Korean National Healthcare-associated Infections Surveillance System. Of all subjects, 200 used Tegaderm™ (Tegaderm group), and the remaining 200 used CHG Tegaderm (CHG Tegaderm group) dressing at the catheter insertion site. Data were analyzed using the χ² test or Fisher's exact test, t-test, and logistic regression analysis using SPSS WIN 21.0. Results: In the Tegaderm and CHG Tegaderm groups, CLABSI incidences were 5.89 and 1.79 per 1,000 catheter-days, catheter colonization incidences were 3.93 and 1.43 per 1,000 catheter-days, and central line bundle compliance rates were 26.0% and 49.0%, respectively. Catheter colonization risk factors were 'reinsertion after failure' and 'Tegaderm dressing' at the central line insertion site. CLABSI risk factors were 'incomplete performance of 7 central line bundle items' and 'Tegaderm dressing' at the central line insertion site. Conclusion: A further prospective study is needed to examine the effects of central line bundle with CHG Tegaderm dressing, avoiding central line reinsertion after failure, and improving the bundle compliance in reducing catheter colonization and CLABSI.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.9B
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• pp.1668-1675
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• 1999

In this thesis, a narrowband bandpass filter using HTS is proposed for the multiplexer of the satellite communication subsystems. The proposed structure using HTS provides the narrower band and the lower insertion loss characteristics than the conventional parallel-coupled-line bandpass filter. The filter structure using hairpin-line only cause the spurious modes due to the surface waves. But these modes can be lessened by using the hybrid hairpin-line/parallel-coupled-line proposed in this thesis. The narrowband bandpass filters using HTS at the operation frequency of 14.25 GHz are fabricated to have the narrow bandwidth less 1% and the insertion loss less 3dB in comparison with the normal metal microstrip filter with the same three poles. The experimental results show that the filter using HTS has the characteristics of the narrower bandwidth and less insertion loss and can be fabricated with more compact size in comparison with the bandpass filter using normal metal.