• Journal of the Microelectronics and Packaging Society
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• v.6 no.4
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• pp.9-14
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• 1999

In this paper, we proposed a simultaneous switching noise (SSN) reduction technique in multi-layer boards (MLB) for high-speed digital applications and analyzed it using the Finite Difference Time Domain (FDTD) method. The new structure using conductive dielectric substrates is effective for the reduction of SSN couplings and resonances. The uniform insertion of the conducive layer reduced the SSN coupling and resonance by 85% and the partial insertion only around the edges reduced by 55% respectively.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2005.11a
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• pp.383-386
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• 2005

In this paper, proposed new partial resonance ZCS PWM controlled High frequency insulated Full-bridge DC-DC converter not using exciting current of high frequency transformer. It is compared with the existing principles in characteristics. It also realizes a widely stabilized ZVS operating using new ON-OFF control method at synchronized power rectification MOSFET of high frequency insulated transformer secondary. Besides, it is brought over 97[%] measurement efficiency by proposed DC-DC converter.

• Proceedings of the KIEE Conference
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• 2003.11a
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• pp.31-33
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• 2003

Power system restoration following a partial or complete blackout starts with energizing of primary transmission lines. Because system changed rapidly during early restoration process, transformer energization and load pickup is executed to maintain the power system stability. However unexpected problem such as harmonic overvoltage may be arisen during energizing transformer. The reason of harmonic overvoltage is known as transformer saturation and magnetizing in-rush current and so on, but it is difficult to estimate the condition of occurrence. This paper describes the analysis of the harmonic overvoltage while unloaded transformer is energized using PSCAD/EMTDC.

• Proceedings of the KIEE Conference
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• 2005.07b
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• pp.1413-1415
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• 2005

In paper, propose new partial resonance ZCS PWM controlled High frequency insulating Full-bridge DC/DC converter not using exciting current of high frequency transformer. It is compared with the existing principles in characteristics. It also realizes a widely stabilized ZVS operating using new On-Off control method at synchronized power rectification MOSFET of high frequency insulating transformer secondary. Finally, it is brought over 97[%] measurement -efficiency by proposed DC-DC converter. It is proved effectiveness of new methods using DC UPS PWM rectifier as switching power.

• Journal of Korean Neurosurgical Society
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• v.38 no.1
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• pp.71-73
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• 2005

A case of intramedullary spinal cord lipoma is presented. A one month-old male infant presented with irritability and weakness on his upper extremities. A magnetic resonance[MR] image of the cervical spine demonstrated a well defined, high signal intensity lesion on both T1 and T2-weighted MR images and suppression on the fat saturation sequence. The tumor mass extended from the foramen magnum to T2 vertebra level. Ventral displacement of the spinal cord with kinking of the cervico-medullary junction was evident on the T2-weighted sagittal image. Partial resection of the tumor mass through laminoplastic laminotomy from C1 to T2 resulted in improved motor weakness on his upper extremities.

• Journal of Oral Medicine and Pain
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• v.43 no.4
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• pp.142-146
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• 2018

Patients with temporomandibular disorder often present with acute occlusal change and properly managed with conservative treatment. If such change is caused by unusual etiology, differential diagnosis may be challenged. This article describes the diagnosis of a patient exhibiting pain and acute posterior open bite on the ipsilateral side after chewing hard food. After initial conservative treatment failed to resolve the complaint, magnetic resonance imaging was ordered and confirmed partial perforation of articular disc. Disc perforation itself is usually chronic in nature, but sudden macrotrauma may also cause the disorder. However, occlusal discrepancy caused by disc perforation is rare and seldom reported. We present a case of acute malocclusion caused by disc perforation with a review of related literature.

• Journal of Oral Medicine and Pain
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• v.49 no.2
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• pp.29-34
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• 2024

Acute malocclusion can occur in conditions related to temporomandibular joint (TMJ) disorders. This report presents two cases of acute malocclusion related to posterior disc displacement according to complete disc tearing. A 65-year-old male and an 88-yearold female presented with TMJ pain and occlusal discrepancies. Clinical examination, computed tomography, and magnetic resonance imaging revealed complete disc tearing and posterior displacement of a partial disc fragment. Dental cast analysis revealed a slight anterior and lateral deviation of the mandible toward the non-affected side; however, clinically, significant occlusal changes were not observed. This was attributed to the displacement of a small disc fragment rather than the entire disc. Including the cases presented, most instances of complete disc tearing responded well to conservative treatment such as pharmacotherapy and physical therapy, resulting in pain alleviation, and residual occlusal changes were tolerable for the patients in their daily activities. However, persistent occlusal changes or severe chewing difficulty may require surgical intervention.

• Investigative Magnetic Resonance Imaging
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• v.13 no.1
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• pp.22-30
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• 2009

Purpose : Patient motion during magnetic resonance (MR) imaging is one of the major problems due to its long scan time. Entropy based post-processing motion correction techniques have been shown to correct motion artifact effectively. One of main limitations of these techniques however is its long processing time. In this study, we propose several methods to reduce this long processing time effectively. Materials and Methods : To reduce the long processing time, we used the separability property of two dimensional Fourier transform (2-D FT). Also, a computationally light metric (sum of all image pixel intensity) was used instead of the entropy criterion. Finally, partial Fourier reconstruction, in particular the projection onto convex set (POCS) method, was combined thereby reducing the size of the data which should be processed and corrected. Results : Time savings of each proposed method are presented with different data size of brain images. In vivo data were processed using the proposed method and showed similar image quality. The total processing time was reduced to 15% in two dimensional images and 30% in the three dimensional images. Conclusion : The proposed methods can be useful in reducing image motion artifacts when only post-processing motion correction algorithms are available. The proposed methods can also be combined with parallel imaging technique to further reduce the processing times.

• Journal of Korean Neurosurgical Society
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• v.30 no.sup1
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• pp.44-50
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• 2001

Objectives : The objective of this study was to investigate the role of postoperative three dimensional short-range magnetic resonance angiography(3D-TOF MRA) in predicting the clinical outcomes following microvascular decompression(MVD) for the treatment of a hemifacial spasm(HFS). Material and Method : Postoperative magnetic resonance(MR) imaging was performed on 123 patients with a HFS between March 1999 and May 2000. All patients who had postoperative MR imaging were undertaken preoperative MR imaging. Of the 123 patients, 122 patients were included in this retrospective study. The degree of the detachment of vascular contact, and change of the position of offender were determined by pre- and postoperative 3D-TOF MRA. These findings were compared with the surgical findings and clinical outcomes. Results : Of 122 patients who had successful MVD, clear decompression of offenders of the root entry zone(REZ) of facial nerve was found in 106 patients(86.9%), partial decompression in 10 patients(8.2%) and contact of offenders to the REZ of facial nerve in 6 patients(4.9%) by the postoperative 3D-TOF MRA. Our patients demonstrated that the types of offender did not influence with the degree of decompression of REZ of facial nerve and with surgical outcomes(p>0.05). Also, there was no significant relationship between the degree of decompression of the REZ of facial nerve from offenders and an improvement of symptoms(p>0.05). Futhermore, there was no significant relationship between the degree of decompression of the REZ of facial nerve from offenders and an improvement time (p>0.05). Conclusion : Our data suggests that MVD of facial nerve alone may not be sufficient to resolve the symptoms in all patients with hemifacial spasm. Therefore, another unknown factors besides vascular compression may be involved to cause symptoms in certain patients and it may be necessary to remove these factors with MVD simultaneously to obtain the resolution of symptom.

• BMB Reports
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• v.40 no.5
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• pp.832-838
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• 2007

A novel inhibitory protein against blood coagulation factor Va (FVa) was purified from muscle protein of granulated ark (Tegillarca granosa, order Arcoida, marine bivalvia) by consecutive FPLC method using anion exchange and gel permeation chromatography. In the results of ESI-QTOF tandem mass analysis and database research, it was revealed that the purified T. granosa anticoagulant protein (TGAP) has 7.7 kDa of molecular mass and its partial sequence, HTHLQRAPHPNALGYHGK, has a high identity (64%) with serine/threonine kinase derived from Rhodopirellula baltica (order Planctomycetales, marine bacteria). TGAP could potently prolong thrombin time (TT), corresponding to inhibition of thrombin (FIIa) formation. Specific factor inhibitory assay showed that TGAP inhibits FVa among the major components of prothrombinase complex. In vitro assay for direct-binding affinity using surface plasmon resonance (SPR) spectrometer indicated that TGAP could be directly bound with FVa. In addition, the binding affinity of FVa to FII was decreased by addition of TGAP in dose-dependant manner ($IC_{50}$ value = 77.9 nM). These results illustrated that TGAP might interact with a heavy chain of FVa ($FVa_H$) bound to FII in prothrombin complex. The present study elucidated that non-cytotoxic T. granosa anticoagulant protein (TGAP) bound to FVa can prolong blood coagulation time by inhibiting conversion of FII to FIIa in blood coagulation cascade. In addition, TGAP did not significantly (P < 0.05) show fibrinolytic activity and cytotoxicity on venous endothelial cell line (ECV 304).