• Journal of Technologic Dentistry
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• v.26 no.1
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• pp.209-216
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• 2004

The purpose of this study is to introduce how to make implant supported over denture with Oring. Many kinds of attachments have used to dental restorations. The application of attachment has widely increased implant fixed prosthesis and implant supported over denture. In order that implant supported over denture have properly retention, generally used O-ring, magnetic, bar attachment. O-ring give us an advantage that is required more minimum vertical dimension than bar-type and easily replace with new part. When we make these prosthesis using O-ring, Bar, Ball attachment, we should following procedures. Strong occlusion force leads to fracture of over denture because part of functional mechanism as implant abutment or attachment is spaced. Clips are regularly activated. O-ring and springs are changed every year. The pattern of resorption should be carefully monitored and compensated for by relining procedures. If the over denture appears to rest on the bar or the ball attachments, relining should be performed and clips/caps should be changed.

• Investigative Magnetic Resonance Imaging
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• v.25 no.2
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• pp.93-100
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• 2021

Purpose: (1) To evaluate the trabecular pattern at the femoral attachment of the posterior cruciate ligament (PCL) in patients with a PCL injury; (2) to analyze bone microarchitecture by applying gray level co-occurrence matrix (GLCM)-based texture analysis; and (3) to determine if there is a significant relationship between bone microarchitecture and posterior instability. Materials and Methods: The study included 96 patients with PCL tears. Trabecular patterns were evaluated on T2-weighted MRI qualitatively, and were evaluated by GLCM texture analysis quantitatively. The grades of posterior drawer test (PDT) and the degrees of posterior displacement on stress radiographs were recorded. The 96 patients were classified into two groups: acute and chronic injury. And 27 patients with no PCL injury were enrolled for control. Pearson's correlation coefficient and one-way ANOVA with Bonferroni test were conducted for statistical analyses. This protocol was approved by the Institutional Review Board. Results: A thick and anisotropic trabecular bone pattern was apparent in normal or acute injury (n = 57/61;93.4%), but was not prominent in chronic injury and posterior instability (n = 31/35;88.6%). Grades of PDT and degrees of posterior displacement on stress radiograph were not correlated with texture parameters. However, the texture analysis parameters of chronic injury were significantly different from those of acute injury and control groups (P < 0.05). Conclusion: The trabecular pattern and texture analysis parameters are useful in predicting posterior instability in patients with PCL injury. Evaluation of the bone microarchitecture resulting from altered biomechanics could advance the understanding of PCL function and improve the detection of PCL injury.

• 대한치과보철학회:학술대회논문집
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• 1999.11a
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• pp.38-39
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• 1999

• Journal of IKEEE
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• v.23 no.1
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• pp.306-309
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• 2019

Wireless charging is a technology of transmitting power through an air gap to an electrical load for the purpose of energy dissemination. Compared to traditional charging with code, wireless power charging has many benefits of avoiding the hassle from connecting cables, rendering the design and fabrication of much smaller devices without the attachment of batteries, providing flexibility for devices, and enhancing energy efficiency, etc. A transmitting coil and a receiving coil for inductive coupling or magnetic resonant coupling methods are available for the near field techniques, but are not for the far field one. In this paper, the wireless power transfer (WPT) circuit by using magnetic resonant coupling method with a resonant frequency of 13.45 Mhz for the low power system is implemented to measure the power transmission efficiency in terms of mutual distance and omnidirectional angles of receiver.

• Smart Structures and Systems
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• v.1 no.4
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• pp.325-338
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• 2005

Utilizing robotic based reconfigurable nodal structural health monitoring systems has many advantages over static or human positioned sensor systems. However, creating a robot capable of traversing a variety of civil infrastructures is a difficult task, as these structures each have unique features and characteristics posing a variety of challenges to the robot design. This paper outlines the design and implementation of a novel robotic platform for deployment on ferromagnetic structures as an enabling structural health monitoring technology. The key feature of this design is the utilization of an attachment device which is an advancement of the common magnetic base found in the machine tool industry. By mechanizing this switchable magnetic circuit and redesigning it for light weight and compactness, it becomes an extremely efficient and robust means of attachment for use in various robotic and structural health monitoring applications. The ability to engage and disengage the magnet as needed, the very low power required to do so, the variety of applicable geometric configurations, and the ability to hold indefinitely once engaged make this device ideally suited for numerous robotic and distributed sensor network applications. Presented here are examples of the mechanized variable force magnets, as well as a prototype robot which has been successfully deployed on a large construction site. Also presented are other applications and future directions of this technology.

• Imaging Science in Dentistry
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• v.33 no.2
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• pp.63-70
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• 2003

Purpose: To describe the MRI findings of the retrodiskal tissue in patients presenting with TMJ internal derangement and to correlate these findings with clinical and other MRI manifestations. Materials and Methods: One hundred eighteen joints of 63 patients with TMJ internal derangement were examined by MRI. Tl-weighted sagittal MR images taken in both closed- and open-mouth were evaluated for the presence of demarcation between disk and retrodiskal tissue, the presence of low signal intensity, and the depiction of the temporal part of the posterior attachment. The results were correlated with the duration of TMJ internal derangement, the presence of pain, and other MRI findings, including the type of internal derangement, the extent of disk displacement, the degree of disc deformation, and the presence of osteoarthrosis. Results: A significant relationship between the presence of low signal intensity in the retrodiskal tissue and other MRI findings was determined. Low signal intensity on the open-mouth view was observed more frequently in patients with disc displacement without reduction, severe disc displacement and deformation, and osteoarthrosis (p<0.05). The demarcation between disk and retrodiskal tissue, and the depiction of the temporal part of the posterior attachment(TPA) were correlated neither with clinical, nor with other MRI findings. Conclusion: This study suggests that low signal intensity in the retrodiskal tissue on open-mouth MR image can be indicative of advanced stages of disk displacement.

• The Journal of Korean Academy of Prosthodontics
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• v.46 no.3
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• pp.261-268
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• 2008

STATEMENT OF PROBLEM: Detachment of the magnetic assembly from the denture base has been a problem in magnetic overdenture patients. PURPOSE: The objectives of this study were to compare the dislodging force by the fixing materials and the designs of the magnetic assembly, and to compare the effect between the fixing materials and the designs of the magnetic assembly. MATERIAL AND METHODS: Two fixing materials, Jet denture repair $acrylic^{(R)}$ and Super-$Bond^{(R)}$ C&$B^{(R)}$ and two types of magnetic assembly designed with or without wing were used. Each magnetic assembly was fixed in the chamber of the denture base resin block ($Lucitone^{(R)}$199) with each fixing material respectively. These specimens were thermocycled 2,000 cycles in the water held at $4^{\circ}C$ and $60^{\circ}C$ with a dwell time of 1 min each time. Each specimen was seated in a testing jig and then a push-out test was performed with a universal testing machine at a cross head speed of 0.5 mm/min to measure the maximum dislodging forces. RESULTS: Comparing the fixing materials, Super-Bond C&$B^{(R)}$ showed superior dislodging force than Jet denture repair $acrylic^{(R)}$. Comparing the design of the magnetic assemblies, the wing design magnetic assembly showed better dislodging force. Combination of the Super-Bond C&$B^{(R)}$ as a fixing material and wing design magnetic assembly revealed a greatest dislodging force. The kind of fixing material was more influential than the type of magnetic assembly. CONCLUSION: The dislodging force of Super-Bond C&$B^{(R)}$ was significantly higher than Jet denture repair $acrylic^{(R)}$. And the dislodging force of magnetic assembly which have wing design was significantly higher than magnetic assembly which have no wing design.

• Journal of the Korean Ceramic Society
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• v.51 no.6
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• pp.570-574
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• 2014

Magnetic-graphene nanosheets have been synthesized via a simple effective chemical precipitation method followed by heat treatment. The composite nanosheets are super paramagnetic at room temperature and can be separated by an external magnetic field. The prepared magnetic-graphene nanosheets were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy, and BET surface area analysis. The results demonstrated the successful attachment of iron oxide nanoparticles to graphene nanosheets. It was found that the attached nanoparticles were mainly $Fe_3O_4$. The magnetic-graphene nanosheets showed near complete methyl orange removal within 10 mintues and would be practically usable for methyl orange separation from water.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.21 no.4
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• pp.601-607
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• 2012

The magnetic abrasive polishing (MAP), for online monitoring with AE sensor attachment, was performed in this study. To predict the surface roughness after the magnetic abrasive polishing of NAK80, the signal data acquired from the AE sensor were analyzed. A dimensionless coefficient, which consisted of average of AErms and standard deviation of AE signal, was defined as a characteristic of the MAP and a prediction model was obtained using least square method. A neural network, which had multiple input parameters from AE signals and polishing conditions, was applied for predicting the surface roughness. As a result of this study, it was seen that there was very close correlation between the AE signal and the surface roughness in the MAP. And then on-line prediction of the surface roughness after the MAP of the NAK80 was possible by the developed prediction model.

• Investigative Magnetic Resonance Imaging
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• v.17 no.4
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• pp.308-311
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• 2013

Deep sylvian meningioma is a rare form of meningiomas. So far, only 4 cases including the present one have been reported in South Korea. A 43-year-old man without any previous medical history presented to our hospital with seizure. There was a rim enhancing mass in the right deep sylvian fissure without dural attachment on magnetic resonance images. Surgical resection of the mass revealed the lesion to be a meningioma in this patient.