• The Korean Journal of Physiology and Pharmacology
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• v.2 no.5
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• pp.581-589
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• 1998

A regulating mechanism of the ATP-sensitive potassium channels $(K_{ATP}\;channels)$ is yet to fully explained. This study was carried out to investigate the effects of intracellular application of monocarboxylates (acetate, formate, lactate, and pyruvate) on $K_{ATP}$ channels in isolated rabbit ventricular myocytes. Single channel currents of $K_{ATP}$ channels were recorded using the excised inside-out or permeabilized attached (open-cell) patch-clamp technique at room temperature. Intracellular application of acetate, formate and pyruvate led to an inhibition of channel activity, whereas intracellular application of lactate increased channel activity. These effects were reversible upon washout. Analysis of single channel kinetics showed that monocarboxylates did not affect open-time constant and close-time constant. These results suggest that monocarboxylates participate in modulating $K_{ATP}$ channels activity in cardiac cells and that modulation of $K_{ATP}$ channels activity may resolve the discrepancy between the low $K_i$ in excised membrane patches and high levels of intracellular ATP concentration during myocardial ischemia or hypoxia.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.36 no.1
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• pp.30-36
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• 2014

There are many treatment options in management of mandibular condylar neck fractures. Closed reduction is the most conservative treatment; however, achievement of anatomic reduction is difficult, and there are some risks of mandibular functional impairment. Open anatomic reduction and internal fixation have some advantages; therefore, many oral and maxillofacial surgeons have attempted to achieve anatomic reduction through the open approach and extracorporeal reduction and fixation. However, when using this method, there is some risk of resorption of the fractured mandibular condylar head. Therefore, we designed a modified extracorporeal reduction technique, without detaching the lateral pterygoid muscle in order to maintain the blood supply to the fractured mandibular condylar head. We believe that this minor modification may minimize the risk of resorption of the fractured mandibular condylar head. In this article, we introduce this technique in detail, and report on two cases.

• KIPS Transactions on Software and Data Engineering
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• v.6 no.12
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• pp.581-586
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• 2017

This paper proposes a GPU based water surface animation and rendering technique for interactive applications such as games. On the water surface, a lot of physical phenomenon occurs including reflection and refraction depending on the viewing direction. When we represent the water surface, not only showing them in real time, but also make them adjusted automatically. In our implementation, we are able to capture the reflection and refraction through render-to-texture technique and then modify the texture coordinates for applying separate DU/DV map. Also, we make the amount of ratio between reflection and refraction change automatically based on Fresnel formula. All proposed method are implemented using OpenGL 3D graphics API.

• Proceedings of the KSRS Conference
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• 2007.10a
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• pp.442-444
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• 2007

How to observe the atmosphere is a subject of atmospheric research. The meteorological satellites and the ground states are used to do observation. However, both ways do not satisfy the requirement of scientists, especially the profiles of atmosphere on the ocean and the data for global atmosphere. Radio occultation (RO) technique, which has been used in planet science, is a method to solve the problem. In RO technique, the low Earth orbit (LEO) satellite receives the two frequency signal of Global Positioning System (GPS) satellite. The excess phase of the signal is calculated to retrieve the profiles of atmosphere parameters. In moist troposphere, the fluctuations appear in the phase of the signal and open loop (OL) is used to resolve it. The quality of the GPS signal generally deteriorates as the altitude decreases. In the procedure, the SNR of the GPS signal is used as the criterion. However, the SNR decreases with fluctuation which makes it difficult to locate the data of poor quality. In this paper, the phase of the signal will be used as part of the criterion.

• Journal of the Society of Naval Architects of Korea
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• v.51 no.2
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• pp.162-170
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• 2014

A CFD(Computational Fluid Dynamics) analysis is presented to predict hydrodynamic characteristics of a marine propeller. A commercial RANS(Reynolds Averaged Navier-Stokes equation) solver, namely FLUENT, is utilized in conjunction with fully unstructured meshes around rotating propeller. Mesh generation process is greatly accelerated by using fully unstructured meshes composed of both isotropic and anisotropic tetrahedral elements. The anisotropic tetrahedral elements were used in the flow domain near the blade and shaft, where the viscous effect is important, having complex shape yet resolving the thin boundary layers. For other regions, isotropic tetrahedral elements are utilized. Two different approaches simulating rotational effect of the propeller are employed, namely Moving reference frame technique for steady simulation, and Sliding mesh technique for unsteady simulation. Both approaches are applied to the propeller open water (POW) test simulation. The current results, which are thrust and torque coefficients, are compared with available experimental data.

• Journal of Power Electronics
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• v.11 no.6
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• pp.801-810
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• 2011

An open circuit fault diagnostic method in IGBTs for the ac to dc converters used in microgrid applications is developed in this paper. An ac to dc converter is a key technology for microgrids in order to interface both distributed generation (DG) and renewable energy resources (RES). Also, highly reliable ac to dc converters are necessary to keep converters in continuous operation as long as possible during power switch fault conditions. Therefore, the proposed fault diagnostic method is developed to reduce the fault detection time and to avoid any other fault alarms because continuous operation is desired. The proposed diagnostic method is a combination of the absolute normalized dc current technique and the false alarm suppression algorithm to overcome the long fault detection time and fault alarm problems. The simulation and experimental results show that the developed fault diagnostic method can perform fault detection within about one cycle. The results illustrate that the reliability of an ac to dc converter interfaced with a microgrid can be improved by using the proposed fault diagnostic method.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.55 no.6
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• pp.286-295
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• 2006

This paper presents a design of a real-time software GPS receiver which runs on a PC. The software GPS receiver has advantages over conventional hardware based receivers in terms of flexibility and efficiency in application oriented system design and modification. In odor to reduce the processing time of the software operations in the receiver, a shared memory structure is used with a dynamic data control, and the byte-type IF data is processed through an Open Multi-Processing technique in the mixer and integrator which requires the most computational load. A high speed data acquisition device is used to capture the incoming high-rate IF signals. The FFT-IFFT correlation technique is used for initial acquisition and FLL assisted PLL is used for carrier tracking. All software modules are operated in sequence and are synchronized with pre-defined time scheduling. The performance of the designed software GPS receiver is evaluated by running it in real-time using the real GPS signals.

• Archives of Craniofacial Surgery
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• v.23 no.5
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• pp.211-219
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• 2022

Background: Correction of secondary cleft nose deformity is one of the most important portions in the management of cleft lip patients. Various techniques have been introduced to achieve adequate shape, balance, and symmetry of anatomical landmarks. None of these methods can claim to universally solve all aspects of the problems encountered in secondary cleft deformity surgery. Some authors overlook the aspect of functional rehabilitation with regard to nasal respiratory pathway problems, which is present in over 90% of the patients. This study aimed to evaluate the aesthetic and functional improvements of the authors' non-destructive technique. Methods: With over 15 years of experience, open rhinoplasty was performed, which included total remodeling of the deformed lower lateral cartilage using several suture fixation techniques without any graft or implantation with septo-turbinoplasty. A total of 150 questionnaires were sent by e-mail, but 55 completed questionnaires were returned. Surgical outcomes were evaluated using questionnaire responses, and outcomes were divided into five categories each for esthetic and functional analyses. Results: The satisfaction rate ranged from 75 % to 98%, which means "more or less," "very much," and "absolutely yes" in the esthetic and functional viewpoints. Conclusion: The results of this study strongly recommend performing the suture fixation technique and functional rehabilitation simultaneously for cleft lip/nose correction.

• Journal of Korean Tunnelling and Underground Space Association
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• v.19 no.3
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• pp.489-501
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• 2017

The collapse accidents during a open ground excavation in urban areas not only lead to human injuries and material damages in the construction site, but also lead to road sinks and damages to the adjacent facilities due to settlement of ground around the construction site. Therefore, during a open ground excavation in the urban areas, it is necessary to thoroughly prepare for prevention of collapse accidents, and consider whole construction stage such as planning, design and construction. In this study, the priorities to be managed mainly were obtained in order to prevent collapse accidents during a open ground excavation. After analyzing results from past accidents cases for open ground excavations, priorities were evaluated regarding collapse-inducing elements using the Delphi technique which is a decision-making method by consensus among experts. As a result, insufficient groundwater treatment, bad geotechnical investigation and instability on construction, etc. were obtained as priorities for prevention of collapse accidents.

• Journal of Gastric Cancer
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• v.15 no.3
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• pp.159-166
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• 2015

Purpose: Laparoscopic total gastrectomy (LTG) is more complicated than laparoscopic distal gastrectomy, especially during a surgeon's initial experience with the technique. In this study, we evaluated the short-term outcomes of and learning curve for LTG during the initial cases of a single surgeon compared with those of open total gastrectomy (OTG). Materials and Methods: Between 2009 and 2013, 134 OTG and 74 LTG procedures were performed by a single surgeon who was experienced with OTG but new to performing LTG. Clinical characteristics, operative parameters, and short-term postoperative outcomes were compared between groups. Results: Advanced gastric cancer and D2 lymph node dissection were more common in the OTG than LTG group. Although the operation time was significantly longer for LTG than for OTG ($175.7{\pm}43.1$ minutes vs. $217.5{\pm}63.4$ minutes), LTG seems to be slightly superior or similar to OTG in terms of postoperative recovery measures. The operation time moving average of 15 cases in the LTG group decreased gradually, and the curve flattened at 54 cases. The postoperative complication rate was similar for the two groups (11.9% vs. 13.5%). No anastomotic or stump leaks occurred. Conclusions: Although LTG is technically difficult and operation time is longer for surgeons experienced in open surgery, it can be performed safely, even during a surgeon's early experience with the technique. Considering the benefits of minimally invasive surgery, LTG is recommended for early gastric cancer.