• Proceedings of the Optical Society of Korea Conference
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• 2005.02a
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• pp.32-33
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• 2005

• Journal of the Society of Cosmetic Scientists of Korea
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• v.30 no.1
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• pp.135-140
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• 2004

Anti-skin aging agent could be have an inhibition effect of ROS production as well as fragmentation and change of collagen cross linkage in collagen molecule. For the monitoring of lipid peroxidation and collagen degradation, the skin of young and old rats were incised and observed 7 days. In the result, the wound closure was observed in the skin from 10 of 11 young rats and in 8 of 11 old rats. And the longer wound length but shorter wound closure, weaker collagen density and thicker epidermis were observed in old rats than in young rats. The level of hydroxyproline as a parameter of collagen synthesis and MDA as a parameter of lipid peroxidation was lower in old group than in young group. The cyst and lacuna between collagen bundle and fibroblast were observed in old rats in contrast to young rats. So that we propose that MDA and hydroxyproline could be used for monitoring of anti-skin aging agent.

• Composites Research
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• v.14 no.6
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• pp.24-31
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• 2001

Filament wound structures such as pressure tanks, pipes and motor cases of rockets are widely used in the aerospace application. The determination of a proper winding angle and thickness is very important to decrease manufacturing difficulties and to increase structural efficiency. In this study, possible winding angles considering the slippage between a fiber and a mandrel surface are calculated using the semi-geodesic path equation. In addition, finite element analysis using ABAcUS are performed to predict the behavior of filament wound structures considering continuous change of winding angle along the dome part. The water-pressuring tests of 3rd stage motor case are performed to verify the analysis procedure. The strain gages are attached on the surface in the fiber direction. Progressive failure analysis is performed to predict the burst pressure and the weakest region of the motor case. The effect of reinforcement is also studied to increase its performance.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2003.10a
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• pp.141-145
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• 2003

The FBG sensors are inserted on the liners of the filament wound pressure tanks. The strains near the welding region of the liners are monitored in the hydro-pressurizing tests. The hydro-pressurizing tests consist of the proof tests at 4500 or 3300 psi and repeated test at the operating pressure, 3000 psi. The FBG sensors work well under $3000\mu\varepsilon$, but the strains calculated from the reflected signals are instable at the high strain level. The transverse compression on the sensor head results in the split of the reflected peaks, and the calculating algorism from the split peaks is not robust under the various signal condition. The FBG sensors fracture near $7500\mu\varepsilon$ level and lose their function permanently.

• Journal of Periodontal and Implant Science
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• v.32 no.2
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• pp.291-302
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• 2002

In most of the previous studies, invasive and discrete techniques have been used to monitor the healing process of the gingival graft. However, Laser Doppler Flowmetry(LDF, floLAB(R), Moor Instruments Ltd., England) is a non-invasive technique for measurement of blood flow in the tissue and also allows continuous monitoring. Thus, we tested the usefulness of LDF in monitoring the healing process of free gingival graft at gingival recession. Eleven gingival graft site of 7 patients, including 5 males and 2 females, aged between 21 and 41 years (mean age 28.5) were monitored for the blood flow. The blood flow in gingival graft at coronal site, central site, apical site, mesial site and distal site was measured using LDF. Blood flow was measured at 1- week, 2- week, 3- week and 4- week after gingival graft surgery from 10 a.m. to 2 p.m. Time-course of the healing process was evaluated by statistical analysis using repeated ANOVA and Duncan test. The results were as follows : (1) Blood flow stayed increased for 2 weeks, and then, it was a tendency to decrease. (2) The blood flow at distal site had always higher than mesial site during the measuring periods. (3) The blood flow was high orderly after 1 week ; most coronal site, most apical site, central site. But that was high orderly after 2 week, 3 week, 4 week ; most coronal site, central site, most apical site. In conclusion, LDF was a useful and clinically adaptable method to monitor wound healing process. Our study suggested that it was important to protect surgical site to promote initial wound healing.

• Journal of Electrical Engineering and Technology
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• v.9 no.2
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• pp.559-568
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• 2014

Induction motors are critical components in industrial processes since their failure usually lead to an unexpected interruption at the industrial plant. The studies of induction motor behavior during abnormal conditions and the possibility to diagnose different types of faults have been a challenging topic for many electrical machine researchers. In this regard, an efficient and new method to detect the induction motor-fault may be the application of the Time Synchronous Averaging (TSA) to the stator current Park's Vector. The aim of this paper is to present a methodology by which defects in a three-phase wound rotor induction motor can be diagnosed. By exploiting the cyclostationarity characteristics of electrical signals, the TSA method is applied to the stator current Park's Vector, allowing the monitoring of the induction motor operation. Simulation and experimental results are presented in order to show the effectiveness of the proposed method. The obtained results are largely satisfactory, indicating a promising industrial application of the hybrid Park's Vector-TSA approach.

• New & Renewable Energy
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• v.10 no.3
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• pp.14-21
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• 2014

As the world supply of fossil fuel sources decreases, the need for efficient energy consevation and develping green energy technologies becomes critical. Because of the high cost of the foundation for large turbines and optional high wind speed (over 12 m/s), it is very difficult to be located at inland city. For the solution above mentioned problem, we have been experimented about that not only using the adaption of wind power system on buildings for improving turbine efficiency, but also applying a wound rotor type induction generator for a small wind turbine.In this research, we try to find out the wind direction and wind speed those were measured every 1 min., during operation period, using the anemometers which consist of horizontally spinning cups on a vertical post. Performance testing for small wind turbine generating system was carried out by using the induction motor and invertor. Finally, we measured the power of 1 kW wind turbine system with the clamp meter and a voltmeter.

• Health Policy and Management
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• v.15 no.4
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• pp.26-45
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• 2005

The purposes of this study were to Identify the .level of measurement on quality Indicators and evaluate the existing indicators in order to determine the priority of quality indicators' application in Korean general hospitals. A survey was conducted using a questionnaire. The subjects were quality managers working at general hospital having over 300 beds. The criteria were relevance, reliability, precision, impact, application, and preference to evaluate quality indicators. According to these six criteria, each indicator was evaluated on a five point scale(5: excellent, 1: poor). The response rate was $40.4\%$. The hospitals have monitored the average of 3.8 indicators(median 4). The indicators such as return to operating room, unplanned readmission, cancellation of booked operations, death, hospital infection, cesarean section rate, volume per disease or procedure, readmission, re-operation, blood transfusion, and post-procedural complications were frequently measured. The top ten quality indicators in the evaluation by its relevance, validity, reliability, impact, preference and application were decubitus ulcer, clean wound infection, fall, unplanned return to operation room, transfusion reactions, foreign body left In during procedure, unplanned readmission, wound infection after contaminated surgery, postoperative hemorrhage/hematoma, and cesarean section rate in order. The high priority quality indicators frequently measured could be used as primary national indicators. Standardized guidelines about monitoring indicators and the utilization will preliminarily be needed to compare and reuse the data for various purposes and improve the quality of care continuously.

• Composites Research
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• v.18 no.5
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• pp.1-8
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• 2005

Among many fabrication methods of composite materials, filament winding is the most effective method for fabricating axis-symmetric structures such as pressure tanks and pipes. Filament wound pressure tanks are under high internal pressure during the operation and it has the complexity in damage mechanisms and failure modes. For this reason, it is necessary to monitor the tank through its operation as well as whole fabrication process. A large number of sensors must be embedded into multi points of the tank from its fabrication step for monitoring the whole tank. Fiber optic sensors, especially fiber Bragg grating(FBG) sensors are widely used for various applications because of good multiplexing capabilities. However, we need to develop the embedding technique of FBG sensors into harsh inner environment of the tank far the successful embedment. In this paper, we studied the embedding technique of a number of FBG sensors into filament wound pressure tanks considering multiplexing.

• Archives of Plastic Surgery
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• v.34 no.4
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• pp.432-435
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• 2007

Purpose: The jejunal free flap has the shorter ischemic time than other flap and requires a laparotomy to harvest it. As the evaluation of the perfusion the buried flap is very important, the perfusion of the buried jejunal free flap requires monitoring for its salvage. We tried to improve the monitoring flap method in the jejunal free flap and examined its usefulness. Methods: From March 2002 to March 2006, the monitoring flap method was applied to 4 cases in 8 jejunal free flaps for the pharyngeal and cervical esophageal reconstructions. The distal part of the jejunal flap was exposed without suture fixation through cervical wound for monitoring its perfusion. The status of perfusion was judged by the color change of jejunal mucosa and mesentery. If necessary, pin prick test was performed. Doppler sonography was applied to mesenteric pedicle of the monitoring flap in case of suspicious abnormal circulation. Results: The monitoring flap shows no change in 3 cases, but the congestion happened in one case at the 12 hours after the operation. This congestion was caused by the twisting or kinking of the mesenteric pedicle of the monitoring flap. So, we fixed up the monitoring flap close to adjacent cervical skin for prevention of rotation. Finally, the main part of transferred jejunal flap was intact. Conclusion: The success of a jejunal free flap depends on close postoperative monitoring and early detection of vascular compromise. So, various monitoring methods have been tried, for instance, direct visualization using a fiberoptic pharyngoscope, through a Silastic window placed in the neck flap, or external surface monitoring with an Doppler sonography, use of a buried monitoring probe. But, all of the above have their own shortcomings of simplicity, non-invasiveness, reliability and etc. In our experience, monitoring flap can be a accurate and reliable method.