• Archives of Plastic Surgery
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• v.37 no.4
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• pp.496-498
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• 2010

Purpose: Lacerations requiring formal wound closure compose a significant number of all childhood injuries presenting to the emergency department. The problem with conventional suture technique are that suture removal is quite cumbersome, especially in children. Unwanted soft tissue damage can result in the process of suture removal, which calls for sedation, stressful for both medical personnel and child. The purpose of this study is to introduce the convenient suture technique for pediatric facial lacerations. Methods: Children under the age of four, presenting to the emergency department with facial lacerations were enrolled in the study. From March 2008 to June 2009, 63 patients (41 males and 22 females) with an average age of 1.4 years were treated with our convenient suture technique using utilized a loop suspended above a double, flat tie. Clean, tension free wounds were treated with our technique, wounds with significant skin defect and concomitant fractures were excluded. Results: The Patients were followed-up in 1, 3 and 5 days postoperatively. On the third hospital visit, suture removal was done by simply cutting the loop suspended above the wound margin and gently pulling the thread with forceps. There were no significant differences in the rates of infection and dehiscence compared with conventional suture technique. Conclusion: The use of our technique was to be simple with similar operative time compared with conventional suture technique. Removal of suture materials were easy without unwanted injuries to the surrounding tissue which resulted in less discomfort for the patient and greater parental satisfaction, minimized the complications. It can be considered as a viable alternative in the repair of pediatric facial lacerations.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.23 no.2
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• pp.169-176
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• 2012

This paper uses loop-star basis functions to overcome the low frequency breakdown problem in method of moments (MoM) based on electric field integral equation(EFIE). In addition, p-Type Multiplicative Schwarz preconditioner (p-MUS) technique is employed to reduce the number of iterations required for the conjugate gradient method(CGM). Low frequency instability with Rao Wilton Glisson(RWG) basis functions in EFIE can be resolved using loop-start basis functions and frequency normalized techniques. However, loop-star basis functions, consisting of irrotational and solenoidal components of RWG basis functions, require a large number of iterations to calculate a solution through iterative methods, such as conjugate gradient method(CGM), due to high condition number. To circumvent this problem, in this paper, the pMUS preconditioner technique is proposed to reduce the number of iterations in CGM. Simulation results show that pMUS preconditioner is much faster than block diagonal preconditioner(BDP) when the sparsity of pMUS is the same as that of BDP.

• The korean journal of orthodontics
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• v.31 no.2 s.85
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• pp.199-207
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• 2001

The segmented TMA T-loop spring, used for reciprocal space closure and described by Burstone, was used to achievebodily movement of canine. Photoelastic analysis is a technique for the transformation of internal stress into visible light patterns. The two-dimensional photoelastic stress analysis was performed, and stress distribution was recorded by photography. The purpose of this study was to visualize photoelastically the distribution of forces transmitted to the alveolus and surrounding structures using new segmented TMA T-loop spring for canine retraction. The results were as follows: 1. Decreased activation produced decreased stress of upper 1st. premolar extraction site and increased intrusive stress of upper 1st. molar, regardless of T-loop position. 2. At 5mm activation, More posterior positioning of T-loop Produced an increased stress in upper 1st. premolar extraction site. 3. At 3mm activation, More posterior positioning of T-loop produced an increased stress in upper 1st. premolar extraction site and mesial lower half of upper 1st. molar mesio-buccal root. 4. At 1mm activation, More anterior positioning of T-loop produced an increased stress in upper mesial and blew apex area of upper canine root. 5. 0.25 B/L ratio and 3mm activation produced bodily movement of canine. To summarize, desired tooth movement and anchorage requirement is possible by altering the activation and mesio-distal position of the T-loop spring.

• Proceedings of the KIPE Conference
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• 1997.07a
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• pp.454-459
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• 1997

The good features of a switched reluctance motor(SRM) are appreciated by the appliance manufactures. And it is spread into a commercial and industries market. The few disadvantage of the motor is higher torque ripple and noise. This paper proposes an instantaneous torque control scheme to control a speed precisely. It adapts phase-locked loop (PLL) technique to control speed precisely. In this control scheme, the phase detector signal of the PLL regulates the switching dwell angle flexibly and the loop filter's signal controls adaptively the instantaneous switching voltage. Experimental results show that drive performance is good with low torque ripple.

• Proceedings of the KIPE Conference
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• 2000.07a
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• pp.368-371
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• 2000

The PLL(Phase-Locked Loop) techniques re employed to make the switching frequency of a resonant inverter follow the resonant frequency which may vary due to the load variations during operation. The conventional design guide of PLL is not suitable in these case since the inverter characteristics are not considered. In this paper the phase characteristics of a resonant inverter is analysed and added to the closed loop. And the design of PLL with digital phase detector is illustrated for the output frequency to track the resonant frequency of the inverter.

• Proceedings of the KIPE Conference
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• 2000.07a
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• pp.485-488
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• 2000

In this paper dynamic analyses and control design of a step-down switched-capacitor dc-dc converter are presented. Open-loop dynamics of the converter are analyzed using the stage-space averaging technique. A systmatic control design method that offers excellent closed-loop performance for the converter is proposed, The analysis results and dynamic performance of the converter are verified using 18 W experimental converter that delivers a 5V/3.5V output from a 11-16V input source.

• 제어로봇시스템학회:학술대회논문집
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• 1993.10a
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• pp.920-925
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• 1993

For a multi-input, multi-output system, it is widely known that feedback control gain presents extra freedom pole placement problem. An eigenstructure assignment utilizes this freedom for assignment of all or some elements of the closed-loop eigenvectors. In this paper, a nonlinear optimization technique is adopted to obtain a small gain controller that assigns closed-loop eigenvalues and elements of eigenvectors simultaneously. To illustrate the approach, a numerical example of the Airplane mode decoupling using an advanced fighter is shown.

• Proceedings of the KIPE Conference
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• 1999.07a
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• pp.260-265
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• 1999

This paper describes a novel control method of a three-phase PWM inverter for uninterruptible power supply(UPS) applications. To obtain the fast dynamics and excellent harmonic characteristics, a new state feedback control technique is proposed. The proposed control consists of the inner-loop current and outer-loop voltage controllers with a load current estimator to reduce the effects of the load variations and nonlinearity. In order to verify the effectiveness of the proposed control, the simulation is carried out for various load condition.

• Proceedings of the KIEE Conference
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• 1999.07b
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• pp.566-568
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• 1999

HILS is widely used in the test and evaluation of complex control system. This paper describes the structure of HILS and the control loop performance monitoring of HILS system Distal path delay and FMS(Flight Motion Simulator) dynamics were estimated and output of the estimated model were compared with real FMS output. The monitoring system can be used for analyzing the result of HILS.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2003.11a
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• pp.183-187
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• 2003

The expression for the effects of an amplitude imbalance, a phase imbalance and a delay mismatch on the characteristics of a linearization loop in feedforward amplifiers is derived and analyzed. The simulation results are compared with the results obtained by means of using a commercial simulation tool and the exact agreement is reported.