• International Journal of Highway Engineering
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• v.18 no.3
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• pp.33-45
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• 2016

PURPOSES : Concrete pavement has been used in the construction of the Jungbu expressway in 1987. More than 60% of the pavement on the expressway is currently made of concrete, but most has been used far beyond their design life. Pavement life has been extended through routine maintenance or overlay. However, the structural capacity of the pavement has reached its limit, and extensive rehabilitation/reconstruction with long time traffic blocking should be considered. The three following issues on concrete rehabilitation/reconstruction will be discussed: (1) economic comparison of asphalt inlay and asphalt overlay, (2) economic comparison preventive overlay on a section which is currently good and routine overlay on the section which will be poor, and (3) economic analysis of early-strength concrete when it is used in concrete reconstruction. METHODS : First, various life cycle cost analysis tools were compared, and the proper tool for the extensive rehabilitation/reconstruction was selected. Second, a sensitivity analysis of the selected tool was performed to find the influential input variables, which should be carefully selected in the analysis. Third, three case studies, which can be issues in the rehabilitation/reconstruction of the expressway concrete pavement in Korea, were performed. RESULTS : Asphalt overlay without milling the deteriorated concrete showed 18~25% lower life cycle cost than the current asphalt inlay with milling. The good current preventive overlay on the section was economically justified within the scope of this study. The construction cost limit of the early strength concrete was suggested to be economical for 1, 3, and 7 days of construction alternative opening. CONCLUSIONS : CA4PRS was a viable tool for comparing various rehabilitation/reconstruction issue alternatives. Several concrete issues associated with the rehabilitation/reconstruction of the deteriorated concrete pavement were discussed as mentioned above.

• The Transactions of the Korean Institute of Power Electronics
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• v.22 no.2
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• pp.175-180
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• 2017

The measurement of three-phase current is important to control the instantaneous torque of a interior permanent magnet synchronous motor(IPMSM) using a three-phase inverter. Therefore, shunt resistors are used in low-cost motor-driving systems to measure three-phase current instead of additional current sensors that are too expensive for these systems. However, in certain regions of a space vector plane, shunt resistors cannot reconstruct three-phase current in high-speed driving mode. In this paper, predictive current control is used to compensate for the three-phase current in those regions, which results in a reduction of current ripple in a three-shunt sensing inverter(TSSI) and torque ripple in IPMSM.

• Journal of Biomedical Engineering Research
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• v.24 no.5
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• pp.459-464
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• 2003

The source current distribution in a heart was reconstructed from the magnetocardiogram (MCG) and its clinical usefulness was demonstrated. MCG was measured using 40-channel superconducting quantum interference device (SQUID) gradiometers for a patient of Wolff-Parkinson-White (WPW) syndrome, which has an accessory pathway between the atria and the ventricles. Reconstruction of source current distribution in a plane below the chest surface was performed using minimum norm estimation (MNE) algorithm and truncated singular value decomposition (SVD), In the simulation, we confirmed that the current distributions. which were computed for the test dipoles, represented well the essential feature of the test current configurations, In the current map of WPW syndrome, we observed abnormal currents that would bypass the atrioventricular junction at a delta wave. However, we could not observe such currents any more after the surgery. These results showed that the obtained current distribution using MCG signals is consistent with the electrical activity in a heart and has clinical usefulness.

• Clinics in Shoulder and Elbow
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• v.23 no.1
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• pp.41-47
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• 2020

Ulnar collateral ligament injuries have been increasingly common in overhead throwing athletes. Ulnar collateral ligament reconstruction is the current gold standard for managing ulnar collateral ligament insufficiency, and numerous reconstruction techniques have been described. Although good clinical outcomes have been reported regarding return to sports, there are still several technical issues including exposure, graft selection and fixation, and ulnar nerve management. This review article summarizes a variety of surgical techniques of ulnar collateral ligament reconstructions and compares clinical outcomes and biomechanics.

• Proceedings of the KIPE Conference
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• 1999.07a
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• pp.197-200
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• 1999

In this paper, an algorithm of reconstructing the armature current of the battery car is presented by using MOSFET's on-voltage of the dc chopper and a corresponding circuit is developed with the low-cost analog multiplexer. For driving comfort, the armature current of the motor or the traction force should be properly controlled when the car changes the direction and is accelerated or decelerated and climbs up or down the hill. Therefore, an information of the current is needed for the traction control. The proposed reconstruction algorithm is experimentally verified.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.55 no.2
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• pp.110-114
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• 2006

This paper describes the accident analysis by modelling the current transformer mounting in a metal-clad switchgear at 22.9kV. In analyzing the accident, the reconstruction at the current transformer mounting(VCB connecting guide) has to be taken into account. The accident was modelled as a 3-phase ground fault occurring between the end plate of 22.9kV lines and the safety shutter at the current transformer mounting of the VCB inside the metal clad switchgear. Since the outside maintenance of the metal clad switchgear is restricted by the enclosed compartments, Its circumference has to be kept clean. Through the reconstruction results, it was confirmed that the fault of the enclosed switchboard could be reduced when the shutter made of Fe material was chanted into an insulation.

• 한국전산유체공학회:학술대회논문집
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• 2009.11a
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• pp.193-200
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• 2009

Recently, there have been efforts to construct hybrids among the existing methodologies for multiphase flow such as VOF, Level Set, and Front Tracking with the intention of facilitating simulations of general three-dimensional problems. As one of the hybrid method, we have developed the Level Contour Reconstruction Method (LCRM) for general three-dimensional multiphase flows including phase change. The main idea was focused on simplicity and a robust algorithm especially for the three-dimensional case. It combines characteristics of both Front Tracking and Level Set methods. While retaining an explicitly tracked interface using interfacial elements, the calculation of a vector distance function plays a crucial role in the periodic reconstruction of the interface elements in the LCRM method to maintain excellent mass conservation and interface fidelity. In addition, compact curvature formulation is incorporated for the calculation of the surface tension force thereby reducing parasitic currents to a negligible level.

• KIEE International Transactions on Electrophysics and Applications
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• v.4C no.3
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• pp.123-128
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• 2004

In electrical impedance tomography (EIT), the internal resistivity distribution of the unknown object is computed using the boundary voltage data induced by different current patterns using various reconstruction algorithms. This paper presents a new image reconstruction algorithm based on the genetic algorithm (GA) via a two-step approach for the solution of the EIT inverse problem, in particular for the reconstruction of "static" images. The computer simulation for the 32 channels synthetic data shows that the spatial resolution of reconstructed images in the proposed scheme is improved compared to that of the modified Newton-Raphson algorithm at the expense of an increased computational burden.rden.

• Korean Journal of Bronchoesophagology
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• v.4 no.1
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• pp.15-26
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• 1998

The first successful transthoracic esophagectomy and intrathoracic esophago- gastric anastomosis reported in 1938. Stomach, small intestine, and colon as well as free revascularized grafts have been substituted for excised esophagus. During the past 60 years, there have been substantial advances in preoperative assessment, nutritional support, anesthetic and operative techniques, and postoperative care of patients undergoing esophageal resection and reconstruction. However the hospital mortality and morbidity of esophageal resection and reconstruction is still high and disruption of an intrathoracic esophagogastric anastomosis continues to be the most dreaded complication of esophageal surgery, And the choice of the conduit is still controversial. In this paper, I would like to review the current surgical options available to patients who require esophageal resection and reconstruction as well as the advantages and disadvantages of each technique.

• Archives of Plastic Surgery
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• v.48 no.5
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• pp.498-502
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• 2021

Total and subtotal sternectomy oncological defects can result in large deficits in the chest wall, disrupting the biomechanics of respiration. Reviewing the current literature involving respiratory function and rib motion after sternectomy, autologous rigid reconstruction was determined to provide the optimal reconstructive option. We describe a novel technique for sternal defect reconstruction utilizing a double-barrel, longitudinally oriented, vascularized free fibula flap associated with rib titanium plates fixation. Our reconstructive approach was able to deliver a physiological reconstruction, providing rigid support and protection while allowing articulation with adjacent ribs and preservation of chest wall mechanics.