• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제45권1호
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• pp.29-33
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• 2019

Objectives: Bone density seems to be an important factor affecting implant stability. The relationship between bone density and primary and secondary stability remains under debate. The aim of this study was to compare primary and secondary stability measured by resonance frequency analysis (RFA) between different bone types and to compare implant stability at different time points during 3 months of follow-up. Materials and Methods: Our study included 65 implants (BioHorizons Implant Systems) with 3.8 or 4.6 mm diameter and 9 or 10.5 mm length in 59 patients. Bone quality was assessed by Lekholm-Zarb classification. After implant insertion, stability was measured by an Osstell device using RFA at three follow-up visits (immediately, 1 month, and 3 months after implant insertion). ANOVA test was used to compare primary and secondary stability between different bone types and between the three time points for each density type. Results: There were 9 patients in type I, 18 patients in type II, 20 patients in type III, and 12 patients in type IV. Three implants failed, 1 in type I and 2 in type IV. Stability values decreased in the first month but increased during the following two months in all bone types. Statistical analysis showed no significant difference between RFA values of different bone types at each follow-up or between stability values of each bone type at different time points. Conclusion: According to our results, implant stability was not affected by bone density. It is difficult to reach a certain conclusion about the effect of bone density on implant stability as stability is affected by numerous factors.

• 한국방사선학회논문지
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• 제3권3호
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• pp.23-25
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• 2009

Gd-157 material has very large neutron capture cross section in the thermal region. So it is very useful to shield material for thermal neutrons. Futhermore, in the neutron capture experiment and calculation, the neutron absorption and scattering are very important. Especially these effects are conspicuous in the resonance energy region and below the thermal energy region. In the case of very narrow resonance, the effect of scattering is to be more considerable factor. In the present study, we obtained energy dependent neutron absorption ratios of natural indium in energy region from 0.003 to 100 keV by MCNP-4B Code. The coefficients for neutron absorption was calculated for circular type and 1 mm thickness. In the lower energy region, neutron absorption is larger than higher region, because of large capture cross section (1/v). Furthermore it seems very different neutron absorption in the large resonance energy region. These results are very useful to decide the thickness of sample and shielding materials.

• Annals of Clinical Neurophysiology
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• 제19권2호
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• pp.145-147
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• 2017

Trigeminal neuralgia (TN) is generally characterized by lancinating, unilateral, paroxysmal pain occurring in the distribution of the fifth cranial nerve. TN is diagnosed clinically based on the typical patient history, negative findings in a neurologic examination, and the response to medication. Idiopathic TN is the most common type, but TN can result from vascular malformation, compression, trauma, neoplasm, multiple sclerosis, or inflammation. We report a TN case diagnosed as recurrent trigeminal neuritis of the maxillary branch confirmed by magnetic resonance imaging.

• The Korean Journal of Pain
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• 제23권1호
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• pp.51-54
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• 2010

A herniated intervertebral disc is the most common type of soft tissue mass lesion within the lumbar spinal canal. Magnetic resonance imaging (MRI) is a useful tool for the assessment of patients with lower back pain and radiating pain, especially intervertebral disc herniation. MRI findings of intervertebral disc herniation are typical. However, from time to time, despite an apparently classic history and typical MRI findings suggestive of disc herniation, surgical exploration fails to reveal any lesion of an intervertebral disc. Our patient underwent lumbar disc surgery with the preoperative diagnosis of lumbar disc herniation; however, nothing could be found during the surgical procedure, except a swollen nerve root.

• 한국자기공명학회논문지
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• 제13권1호
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• pp.56-63
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• 2009

SWIRM domain, a core domain of SRG3 is well conserved in SW13, RSC8, and MOIRA family proteins. To understand structural basis for cellular functions of the SWIRM domain, we have initiated biochemical and structural studies on SWIRM domain and mutants using gelfiltration chromatography, circular dichroism and NMR spectroscopy. The structural properties of the mutant SWIRM domains (K34A and M75A) have been characterized, showing that the structures of both wild-type and mutant proteins are a-helical conformation. The data conclude that mutations at interaction sites of its binding partner protein do not affect its secondary and tertiary structure.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2008년도 춘계학술대회논문집
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• pp.280-285
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• 2008

The helmholtz resonator with the perforated neck has demerits that the absorption performance is not so outstanding in an anti-resonance frequency and high frequency bandwidth. In order to overcome these problems, in the paper, a resonator combined with porous material is proposed. The absorption performances of resonators are measured by two-microphone method and estimated by transfer matrix method. The experimentally measured values of normal absorption coefficients agree well with the corresponding values from the transfer matrix method. Because of the porous material, it is shown that the absorption performance have been significantly improved in the anti-resonance frequency and high frequency bandwidth.

• 한국정보통신설비학회:학술대회논문집
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• 한국정보통신설비학회 2009년도 정보통신설비 학술대회
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• pp.215-218
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• 2009

In this paper, Dual-band bandpass filter studied design using Parallel Coupled SIR(Stepped Impedance Resonator). This Dual-band bandpass filter design SIR of half-wavelength by Parallel-coupled type that is available to RFID system and Changed structure in Meander form by size reduce. Because seen Dual-band bandpass filter is designed so that is applicable for frequency 433MHz and 2.45GHz of RFID system is very wide distance between two pass-band, establish 433MHz by fundamental frequency and controlled 2.45GHz by 2st spurious resonance frequency bandstop filter of 1st spurious resonance frequency and Parallel coupled SIR Combine to remove 1st spurious resonance frequency.

• Investigative Magnetic Resonance Imaging
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• 제20권3호
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• pp.200-205
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• 2016

In Korea, tuberculosis is still common disease. Central nervous system tuberculosis can manifest in a variety of forms, including tuberculous meningitis, tuberculous cerebritis, tuberculoma, tuberculous abscess, and miliary tuberculosis. Although intra-axial tuberculomas are the more common type of CNS tuberculosis, extra-axial lesions are rarely encountered. En plaque tuberculoma is an extremely rare presentation of intracranial tuberculosis with mimicking primary or secondary meningeal neoplasia. We describe a rare case of an en plaque tuberculoma accompanied by tuberculous meningitis and tuberculomas.

• Investigative Magnetic Resonance Imaging
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• 제21권4호
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• pp.269-272
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• 2017

Periductal stromal sarcoma (PSS) is a type of rare malignant fibroepithelial tumor. PSS is a recently introduced diagnostic entity and there are few reports about radiological features of this tumor. Pre-operative diagnosis is difficult because it reveals similar symptoms with other benign and malignant tumors with absence of specific radiologic findings. We present a woman age 30 that underwent mammotome biopsy for a BI-RADS 4 lesion on her left breast and received histopathology diagnosis of a phyllodes tumor. Additionally, she underwent a wide excision depending on her histopathology diagnosis. Her final diagnosis was PSS. Six months later, no recurrence was detected. However, frequent follow-up is needed because PSS can develop into phyllodes tumor or entity of breast cancer.

• 대한조선학회 특별논문집
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• 대한조선학회 2013년도 특별논문집
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• pp.55-59
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• 2013

Transverse vibrations of ship's aft end and deckhouse among the various modes of hull structures are induced mainly by transverse exciting forces and moments of main engine such as ${\times}$ and h-moment. Avoidance of resonance should be made in a intial design stage in case there is a prediction for resonance between main engine and transverse modes of deckhouse. This study shows a case of change in type of main engine from 12 cylinders to 10 without modification of hull structures in engine room requested by a shipowner of 8,600 TEU class container carrier and proposes a guide to the effective ways of structural arrangement for avoiding resonance between transverse exciting force and surrounding structures of main engine in engine room through case studies.