• The Korean Journal of Pain
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• v.19 no.2
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• pp.257-260
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• 2006

Radiofrequency neurotomy of the lumbar medial branch, via a caudal approach, is a representative interventional procedure for lumbar zygapophysial joint pain, which can be performed more accurately and easily using a guide needle technique. We experienced a case of burn wound formation along the guide needle trajectory, where heat conduction through the guide needle was suggested to have resulted in the burn wound.

• Archives of Reconstructive Microsurgery
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• v.6 no.1
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• pp.96-102
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• 1997

The gracilis that is frequently used as a donor of free muscle trasfer is appropriate in the muscular shape and vascular position. This muscle is belonged to the second type of muscle group by the classification of the pattern of muscular nutrient vessel. The adductor branch or first perforating branch of deep femoral artery which supplies the proximal 1/3 of this muscle is a dominant one and this is used for the microscopic anastomosis of muscle or musculocutaneous flap. The minor vascular pedicles which enter the distal 1/3 of this of this muscle are branches of the superficial femoral artery and it is 0.5mm in diameter, 2cm in length with two venae comitantes. These minor pedicles supplies distal half of the gracilis muscle. This island musculocutaneous flap using distal vascular pedicle can be used to cover the defect of soft tissue around the distal femoral supra-condylar area, knee joint and proximal tibial condyle area which cause limitation of motion of knee joint, or in the cases that usual skin graft is impossible. The important operative procedure is as follows; The dissection is carried proximally and distally and the entire gracilis muscle including proximal and distal pedicle is completely dissected. After temporary blocking of the proximal vascular pedicle, the adequate muscle perfusion by the distal pedicle is identified and it is rotated to the recipient site around knee joint. The advantages of this procedure are simple, no need of microscopic vascular anastomoses and no significant functional loss of donor site. Especially in the cases of poor condition of the recipient vessel, this procedure can be used effectively. From 1991 to 1996, we performed 4 cases; complete survival of flap in 3 cases and partial survival of flap with partial necrosis in 1 case. This procedure is though to be useful in the small sized soft tissue defect of distal femoral supra-condylar area, knee joint and proximal tibial condylar area, especially in the defect of anterior aspect which expected to cause limitation of motion of knee joint due to scar contracture. But the problems of this procedure are the diameter of distal vascular pedicle is small and the location of distal vascular pedicle is not constant. To reduce the failure rate, identify the muscular perfusion of distal vascular pedicle after blocking the proximal pedicle, or strategic delay will be helpful.

• Journal of Korean Society of Steel Construction
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• v.21 no.5
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• pp.451-459
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• 2009

The purpose of this study was to evaluate the in-plane bending moment for T-joints made of cold-formed square hollow steel sections. In the previous studies, the T-joint was shown not to have an obvious peak load, and the failure mode was the main chord flange failure at the branch-width-to-chord-width ratio ($\beta$) of below 0.71. Based on the experimental results, including the tests conducted by Zhao, the deformation limit of 1% B was proposed for ${16.7{\leq}2{\gamma}(=B/T){\leq}33}$ and ${0.34{\leq}{\beta}(=b_{1}/B){\leq}0.71}$. Then, the ultimate in-plane bending strength was shown to be Mu=1.5${\cdot}$M1% B. The existing strength formulae for the original T-joint were investigated and were determined to be the main chord flange failure for the branch-squared T-joint. The bending strength formulae of CIDECT and other researchers were compared with the test results. Finally, a reasonably good agreement with Zhao's formula was found. Therefore, the design guidelines were presented based on Zhao's strength formula for T-joints.

• Proceedings of the KIEE Conference
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• 2000.07d
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• pp.2705-2707
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• 2000

The branch of the laser imaging has implemented 3D graphics, color graphics and video images after it drew a simple image by development the salvo's X-Y scanner in 1960 year. Now it is used as the multimedia show of an event and an advertisement. The latest issue of laserist is the ability to generate laser images with the same ease and speed associated with traditional computer graphics. All laser projector used in the interior of a countris was imported from other country. The most important component of the laser projector is the speed and the accuracy of a actuator and the software which actuates the controller on computer. In this paper we developed the controller with a universal joint and the PC based user interface software in order to implement the laser image of two dimension, and will prepare the base of beginning the home laser projector

• Journal of Biomedical Engineering Research
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• v.29 no.1
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• pp.32-39
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• 2008

This paper reports on a realtime OS based master-slave configuration robot control system for laparoscopic surgery robot which enables telesurgery and overcomes shortcomings with conventional laparoscopic surgery. Surgery robot system requires control system that can process large volume information such as medical image data and video signal from endoscope in real-time manner, as well as precisely control the robot with high reliability. To meet the complex requirements, the use of high-level real-time OS (Operating System) in surgery robot controller is a must, which is as common as in many of modem robot controllers that adopt real-time OS as a base system software on which specific functional modules are implemened for more reliable and stable system. The control system consists of joint controllers, host controllers, and user interface units. The robot features a compact slave robot with 5 DOF (Degree-Of-Freedom) expanding the workspace of each tool and increasing the number of tools operating simultaneously. Each master, slave and Gill (Graphical User Interface) host runs a dedicated RTOS (Real-time OS), RTLinux-Pro (FSMLabs Inc., U.S.A.) on which functional modules such as motion control, communication, video signal integration and etc, are implemented, and all the hosts are in a gigabit Ethernet network for inter-host communication. Each master and slave controller set has a dedicated CAN (Controller Area Network) channel for control and monitoring signal communication with the joint controllers. Total 4 pairs of the master/slave manipulators as current are controlled by one host controller. The system showed satisfactory performance in both position control precision and master-slave motion synchronization in both bench test and animal experiment, and is now under further development for better safety and control fidelity for clinically applicable prototype.

• Proceedings of the Korea Concrete Institute Conference
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• 2003.11a
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• pp.219-222
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• 2003

Substantial experimental and theoretical work exists on the bond characteristics of FRP-concrete adhesive joints. Experimental studies show that the bond strength cannot always increase with an increase in the bond length, and that the ultimate strength is strongly influenced by the concrete strength. To solve this feature, analytic solutions based on fracture mechanics are widely used, and the local shear stress-slip curve with a softening branch is known as more rational model. The analytic solution, however, cannot describe various shapes of model curve. In this study, numerical method using interface element is introduced to express various shapes of model curve. Characteristics of adhesive joint is investigated for the shapes of the model curve and their parameters. And the numerical solutions are compared with the test results of CFRP sheet adhesive joints.

• Proceedings of the Korea Concrete Institute Conference
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• 2003.05a
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• pp.902-907
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• 2003

Substantial experimental and theoretical work exists on the bond characteristics of FRP-concrete adhesive joints. Analytic solutions based on fracture mechanics are most commonly accepted for theoretical work on joint. The solutions may be derived for the simple form of the shear strees-slip curve. And it is difficult to determine the model parameters consisting the curve. In this study, the bilinear curve with softening branch is introduced. The model parameters are determined by the method described by the companion paper with comparison of test results. There are many uncertainties in the test results of CFRP sheet adhesive joints, so that test results used for the construction of the regression problem should be reasonably selected.

• The Korean Journal of Pain
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• v.20 no.2
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• pp.111-115
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• 2007

Background: Selective diagnostic blocks of the medial branches of the dorsal primary ramus are usually performed under the guidance of fluoroscopic or computed tomography. Recently, however, ultrasound guidance has been suggested as an altemative method. In this study, the distances between the vertebral structures were measured and compared with the values measured using magnetic resonance imaging (MRI) to assess the clinical feasibility of using ultrasound-guided block in Korean patients. Methods: Five male and 15 female patients were enrolled in this study. The target point of the medial branch block in our study was the groove at the base of the superior articular process, We measured the depth from the skin to the target point at the transverse process (d-TP) and to the most superficial point of the superior articular process (d-AP). Results: The d-TP and d-AP values measured under ultrasound guidance were concordant with the values measured using MRI. Conclusions: The images of the bony landmarks obtained under ultrasound examination could be useful for ultrasound-guided lumbar medial branch block.

• The Korean Journal of Pain
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• v.21 no.2
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• pp.150-154
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• 2008

Pulsed or conventional radiofrequency (RF) denervation of the third occipital nerve (TON) is considered to be a safe and effective alternative for the treatment of pain originating from the cervical 2-3 facet joint, including cervicogenic headache. However, proper positioning of the RF probe in the TON can be difficult and time consuming due to the possible involvement of various lesions along the target nerve. We found that bipolar RF is easier to perform and more convenient than unipolar RF when administering a lumbar medial branch block. Here, we report the successful treatment of a patient with a cervicogenic headache by pulsed RF (PRF) denervation of the TON, using a bipolar probe. We believe that bipolar PRF denervation of the TON is an effective alternative to unipolar RF or PRF for the treatment of pain originating from the cervical 2-3 facet joint.

• Computers and Concrete
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• v.17 no.6
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• pp.723-737
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• 2016

In this paper an approach was described for determination of direction of sliding block in rock slopes containing planar non-persistent open joints. For this study, several gypsum blocks containing planar non-persistent open joints with dimensions of $15{\times}15{\times}15cm$ were build. The rock bridges occupy 45, 90 and $135cm^2$ of total shear surface ($225cm^2$), and their configuration in shear plane were different. From each model, two similar blocks were prepared and were subjected to shearing under normal stresses of 3.33 and $7.77kg/cm^{-2}$. Based on the change in the configuration of rock-bridges, a factor called the Effective Joint Coefficient (EJC) was formulated, that is the ratio of the effective joint surface that is in front of the rock-bridge and the total shear surface. In general, the failure pattern is influenced by the EJC while shear strength is closely related to the failure pattern. It is observed that the propagation of wing tensile cracks or shear cracks depends on the EJC and the coalescence of wing cracks or shear cracks dominates the eventual failure pattern and determines the peak shear load of the rock specimens. So the EJC is a key factor to determine the sliding direction in rock slopes containing planar non-persistent open joints.