• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.11a
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• pp.911-914
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• 2005

The vibrational characteristics of the piezoelectric disc for a torsional vibration transducer is theoretically studied in this paper. The characteristic equation of the piezoelectric annular disc has been derived from Newton's End law and Gibb's free energy equations. With an anisotropic material property of the disc, the characteristic equation has yielded resonance frequencies. Numerically-calculated results were compared with the values obtained by finite element analysis and experiments

• East Asian mathematical journal
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• v.39 no.1
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• pp.11-21
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• 2023

Non-trivial automorphisms of the unit disc in the complex plane can be classified by three classes; elliptic, parabolic and hyperbolic automorphisms. This classification is due to a representation in the projective special linear group of the real field, or in terms of fixed points on the closure of the unit disc. In this paper, we will characterize this classification by the distance function of the Poincaré metric on the interior of the unit disc.

• The korean journal of orthodontics
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• v.24 no.2
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• pp.331-348
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• 1994

The purpose of this study was to investigate changes in the shape and ultrastructure of the articular disc of the rat mandibular joint with aging. Mechanical stress applied to the articular disc changes during neonatal, suckling, juvenile, adult and senile stages. Mandibular joints of 6 groups of rats(1-, 7-, 17-, 27-, 55-day and over-1-year groups) were removed en bloc and processed for light and electro microscopic study. The changes in the shape of articular disc were examined by light microscope in each group. Structural and ultrastructural changes in the articular disc were examined by light and electron microscope in each group. The results were as follows : In the 1-day and 7-day groups, the articular disc was long and slender in shape and the articular disc was not fitted with the shape of the mandibular fossa and condyle. However' after that time, the anterior and posterior portions of the articular disc were more bulged and the middle portion was shorter and biconcave. Thus the articular disc was well fitted with the shape of the mandibular fossa and condyle. The cell density decreased with aging. In the l -day and 7-day groups, the Golgi apparatus, rough endoplasmic reticulum and free ribosome, which are involved in the synthesis of intracellular and extracellular matrix, were developed. In the 17-day, 27-day and 55-day groups, not only the cell organelles involved in the synthesis of the intracellular and extracellular matrix but also the cell organelles involved in the remodeling of the extracellular matrix(i.e., finger-like cell process, lysosome and mitochondria)were well developed. With advancing age, intracytoplasmic microfilaments were more accumulated and condroid cells increased. In the over-1-year group, the majority of cells of the articular disc were chondroid cells. The majority of cytoplasmic compartment were filled with intracytoplasmic microfilaments and cell organelles were not developed. Therefore, metabolic activities of the cell was markedly reduced and cells contained structures enduring mechanical stress, and cells which were in the process of degeneration were observed occasionally.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.25 no.2
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• pp.319-330
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• 1995

This study was designed to evaluate the interrelationship between the condylar head position in transcranial view and the articular disc position in the arthrography. The condylar positions were assessed by subjective method and linear measurement method on the transcranial view. The subjects for this study consisted of 24 symptomatic joints with normal disc position, 37 joints with anterior disc displacement with reduction and 44 joints with anterior disc displacement without reduction that were classified by arthrotomography under the fluoroscopic guidance. The interrelationship between the condylar head position in transcranial view and the articular disc position in the arthrography was evaluated by Chi square test. The obtained results were as follows : 1. There was no significant interrelationship between the position of condylar head in closed mouth state on transcraniaJ view and articular disc position in the arthrography (p>0.05). 2. There was no significant interrelationship between the changes of interarticular distance in 1 inch opening state and articular disc position in the arthrography (p>0.05). 3. There was no significant interrelationship between the position of condylar head related to the apex of articular eminence in 1 inch opening state and articular disc position in the arthrography(p>0.05). 4. There was significant interrelationship between the changes of interarticular distance that is assessed by linear measurement method in maximum opening state and articular disc position in the arthrography(p<0.05), but there was no significant interrelationship when the condylar head position was assessed by subjective method(p>0.05). 5. There was significant interrelationship between the degree of condylar translation in maximum opening state and articular disc position in the arthrography(p<0.05). 6. The correlation coefficient between two methods to assess the position of condylar head were 0.7989: the condylar head position in articular fossa in closed state, 0.6847: interarticular space in 1 inch opening state, 0.8965: the degree of condylar translation in 1 inch opening state, 0.5944: the changes of interarticular space in maximum opening state, 0.9215: the degree of condylar translation in maximum opening state.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.15 no.1
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• pp.12-20
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• 2004

In this paper, the detection of 1 g and 10 g averaged SAR on human head caused by PCS/IMT-2000 handhold phones is analyzed and discussed. Planar structured Single-Semi-disc MPA and double-Semi-disc MPA is designed and resonance characteristics with variety of design parameters are analyzed. As a result, 2.0 ㎓ center frequency, at the bandwidth of single-semi-disc MPA and double-semi-disc MPA are 15.5 ％ and 31 ％, respectively. And monopole antenna with W4 length is designed and compared with double-semi-disc MPA in SARs. The SARs caused by double-semi-disc MPA on folder type handset are 0.811 W/kg and 0.507 W/kg and are about 32.7 ％ lower than monopole-1.206 W/kg and 0.7552 W/kg. While the radiation pattern of the monopole antenna is symmetrical, that of planar structured antenna is asymmetrical and SAR caused by double-semi-disc MPA is less than SAR by the monopole antenna.

• Molecules and Cells
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• v.26 no.2
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• pp.165-170
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• 2008

Procaspase-8 is activated by forming a death-inducing signaling complex (DISC) with the Fas-associated death domain (FADD) and the Fas receptor, but the mechanism of its activation is not well understood. Procaspase-8 devoid of the death effector domain at its N-terminus (${\Delta}nprocaspase-8$) was reported to be activated by kosmotropic salts, but it has not been induced to form a DISC in vitro because it cannot interact with FADD. Here, we report the production of full-length procaspase-8 and show that it is activated by adding the Fas death domain (Fas-DD) and the FADD forming the cytoplasmic part of the DISC (cDISC). Furthermore, mutations known to affect DISC formation in vivo were shown to have the same effect on procaspase-8 activation in vitro. An antibody that induces Fas-DD association enhanced procaspase-8 activation, suggesting that the Fas ligand is not required for low-level activation of procaspase-8, but that Fas receptor clustering is needed for high-level activation of procaspase-8 leading to cell death. In vitro activation of procaspase-8 by forming a cDISC will be invaluable for investigating activation of ligand-mediated apoptosis and the numerous interactions affecting procaspase-8 activation.

• The Korean Journal of Pain
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• v.25 no.3
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• pp.155-160
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• 2012

Background: We have developed an intradiscal pulsed radiofrequency (Disc PRF) technique, using Diskit $II^{(R)}$ needles (NeuroTherm, Wilmington, MA, USA), as a minimally invasive treatment option for chronic discogenic low back pain (LBP). The purpose of this study was to compare the representative outcomes of Disc PRF and Intradiscal Electrothermal Therapy (IDET) in terms of pain relief and reduction of disability. Methods: Thirty-one patients with chronic discogenic LBP who underwent either Disc PRF (n = 15) or IDET (n = 16) were enrolled in the study. A Diskit $II^{(R)}$ needle (15-cm length, 20-gauge needle with a 20-mm active tip) was placed centrally in the disc. PRF was applied for 15 min at a setting of $5{\times}50$ ms/s and 60 V. The pain intensity score on a 0-10 numeric rating scale (NRS) and the Roland-Morris Disability Questionnaire (RMDQ) were assessed pretreatment and at 1, 3, and 6 months post-treatment. Results: The mean NRS was significantly improved from $7.2{\pm}0.6$ pretreatment to$2.5{\pm}0.9$ in the Disc PRF group, and from $7.5{\pm}1.0$ to $1.7{\pm}1.5$ in the IDET group, at the 6-month follow-up. The mean RMDQ also showed significant improvement in both the Disc PRF group and the IDET group at the 6-month follow-up. There were no significant differences in the pretreatment NRS and RMDQ scores between the groups. Conclusions: Disc PRF appears to be an alternative to IDET as a safe, minimally invasive treatment option for patients with chronic discogenic LBP.

• Journal of Acupuncture Research
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• v.26 no.5
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• pp.171-181
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• 2009

Objectives : A ruptured disc is a condition in which part or all of the nucleus pulposus is forced through a weakened part of the disc, resulting in back pain and leg pain caused by nerve root irritation. In this report, we investigated the effect of oriental medicine treatment in parallel with sling exercise therapy on ruptured intervertebral lumbar disc patients. Methods : The patients who have ruptured disc were treated by oriental medicine treatment in parallel with sling exercise therapy. The patients' symptoms were assessed by visual analogue scale(VAS) and revised oswestry disability questionnaire(RODQ) every week. Results : In all cases, chief complain such as lumbago, radicular pain and paresthesia were improved after above treatment. VAS score and RODQ score of all cases were decreased. Conclusions : There were usually thought to need operation in ruptured disc. But conservative treatment such as oriental medicine treatment in parallel with sling exercise therapy is helpful to improve the symptoms of the ruptured intervertebral lumbar disc except the emergency state.

• Journal of Physiology & Pathology in Korean Medicine
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• v.27 no.1
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• pp.124-129
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• 2013

Embedding Therapy keep the stimulation to acupoint. Recently, Embedding Therapy is used for various disease and also studied in many different fields especially in China. In Korea, Embedding Therapy is studied and used for dermatology, face-lift, obesity, facial palsy most frequently. Chinese studies shows us Embedding Therapy could help musculoskeletal system disorder, lumbar herniated intervertebral disc, sprain, spinal canal stenosis. In Korea study concerning lumbar herniated intervertebral disc treatment used Embedding Therapy is few. This study's purpose is to ensure effect of Embedding Therapy at lumbar herniated intervertebral disc treatment. Four lumbar disc herniation patients had been treated with Embedding Therapy were described in this article. The patients(n=4) had been suffering from chronic lower back and leg pain that continued for more than 6 months. All patients had been diagnosed as lumbar disc herniation by MRI or CT, and treated with Embedding Therapy at least 2 times(7 days interval). 2 patients had been treated with concurrent treatment of acupuncture therapy, and the other 2 patients with concurrent treatment of acupuncture and herbal therapy. We observed 4 patients for more than 2 weeks, and their symptoms and quality of daily life had been improved. This suggests that lumbar disc herniation can be successfully recovered with Concurrent Embedding Therapy under conventional Korean Medical Treatment without side effects.

• The Journal of Korean Medicine
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• v.20 no.2
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• pp.200-207
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• 1999

Herniation of intervertevral disc(HIVD) is the most common disease causing low back pain. Acupuncture, electroacupuncture and moxibustion has been used for treatment of HIVD. Bee venom (BV) also has been traditionally applied to relieve pain. Recently, it has been reported that BV is effective in treating HIVD. But more objective methods were required to assess the efficacy of BV on HlVD. So we assessed of BV-acupuncture effect on herniated disc patients by use of rating scale for low back pain. We researched 22 patients who were treated at Department of Acupuncture & Moxibustion, Kyung Hee Medical Center from January 1999 to June 1999. The patients were diagnosed by MRI as having a herniated disc. The results of treatment using rating scale for low back pain in HIVD showed that $43.77{\pm}14.39$ point of pre-treatment score and $84.5{\pm}3.97$ point post-treatment score. The improvement index showed $0.43{\pm}0.15$. Especially, clinical score of neurologic deficits showed most highest improvement index of $0.7{\pm}0.45$. Assessment of BV-acupuncture Effect by MRI finding were showed that protruded disc and extruded disc got more higher improvement index than bulging disc. Among 22 patients, satisfactory assessment of BV-acupuncture effect showed that 15(68.2%) were excellent, and 7(31.8%) were good. The result suggest that BV-acupuncture is good method for treatment of HIVD.