• 제목/요약/키워드: Resonance Type

검색결과 1,096건 처리시간 0.03초

척추전방전위증을 동반한 요추간판 탈출증 환자 32례에 대한 한의학적 임상고찰 (Clinical Study on 32 Patients of Lumbar Herniated Intervertebral Disc with Spondylolisthesis)

  • 이한;정호석;김상주;김은석;한경완;우재혁;이준석;이슬지;이선구;차윤엽
    • 동의생리병리학회지
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    • 제24권6호
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    • pp.1087-1093
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    • 2010
  • The purpose of this study is to survey the effectiveness of oriental medicine treatment on lumbar herniated intervertebral disc and spondylolisthesis. The clinical study was performed on 32 cases of patients with lumbar herniated intervertebral disc and spondylolisthesis as diagnosed by X-ray, Magnetic resonance imaging(MRI) exams amongst the patients who were admitted to Jaseng Hospital of Oriental Medicine from January 2010 to June 2010. 32 cases of patients were analyzed according to the distribution of sex, age, duration of disease, contributory factor, symptoms, admission period, disc herniation type and level of spondylolisthesis. The efficacy of treatment was evaluated respectively. The number of the female patients were larger than that of male with the ratio of 1:0.6. Most of the patients were in their fifties(43.8%), choronic phase(46.9%), those patients suffered from lower back pain and leg pain radiation(90.6%), reasons unknown(56.3%). Most of them also had mixed disc(37.5%), bulging disc(37.5%) and spondylolisthesis of LS on L5(50.0%). Most of them stayed in the hospital for 21-25days. After treatment, the percentage with good improvement was 62.5%, fair 18.8%, poor 12.5%, and excellent 6.3%, respectively. Oriental medicine treatment has on useful effect on the recovery of lumbar herniated intervertebral disc with spondylolisthesis.

Pulmonary Langerhans Cell Histiocytosis in an Adult Male Presenting with Central Diabetes Insipidus and Diabetes Mellitus: A Case Report

  • Choi, Yeun Seoung;Lim, Jung Soo;Kwon, Woocheol;Jung, Soon-Hee;Park, Il Hwan;Lee, Myoung Kyu;Lee, Won Yeon;Yong, Suk Joong;Lee, Seok Jeong;Jung, Ye-Ryung;Choi, Jiwon;Choi, Ji Sun;Jeong, Joon Taek;Yoo, Jin Sae;Kim, Sang-Ha
    • Tuberculosis and Respiratory Diseases
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    • 제78권4호
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    • pp.463-468
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    • 2015
  • Pulmonary Langerhans cell histiocytosis is an uncommon diffuse cystic lung disease in adults. In rare cases, it can involve extrapulmonary organs and lead to endocrine abnormalities such as central diabetes insipidus. A 42-year-old man presented with polyphagia and polydipsia, as well as a dry cough and dyspnea on exertion. Magnetic resonance imaging of the hypothalamic-pituitary system failed to show the posterior pituitary, which is a typical finding in patients with central diabetes insipidus. This condition was confirmed by a water deprivation test, and the patient was also found to have type 2 diabetes mellitus. Computed tomographic scanning of the lungs revealed multiple, irregularly shaped cystic lesions and small nodules bilaterally, with sparing of the costophrenic angles. Lung biopsy through video-assisted thoracoscopic surgery revealed pulmonary Langerhans cell histiocytosis. On a follow-up visit, only 1 year after the patient had quit smoking, clinical and radiological improvement was significant. Here, we report an uncommon case of pulmonary Langerhans cell histiocytosis that simultaneously presented with diabetes insipidus and diabetes mellitus.

좁은 직경 임플란트 3년간의 생존율에 관한 후향적 연구 (A 3 year prospective study of survival rate of narrow diameter implants)

  • 이성조;정세영;신현승;박정철;송영균;조인우
    • 구강회복응용과학지
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    • 제34권1호
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    • pp.32-38
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    • 2018
  • 목적: 3.6 mm 이하 좁은 직경 임플란트의 일정 기간 생존율을 초기고정 값과 방사선학적 계측을 통해 분석해보고자 하였다. 연구 재료 및 방법: 24명의 환자에 식립된 직경 3.6 mm 이하, 길이 7 mm 이상의 38개의 임플란트를 조사하였다. 식립된 임플란트의 platform 직경, body 직경, 길이, 식립 부위 등을 확인하였고 식립 시 골유도재생술의 동반 시행 여부, 완성된 보철의 형태를 확인하였다. 초기고정 값은 임플란트 식립 직후 측정한 implant stability quotient (ISQ) 값을 확인하였고, 방사선 사진을 통해 식립된 임플란트의 근 원심 marginal bone level (MBL)을 측정하였다. 결과: 전체 임플란트의 생존율은 92.11% 이었고 ISQ값은 평균 66.26으로 나타났다. 생존한 임플란트의 MBL 변화는 평균 $0.14{\pm}0.31mm$를 나타내었다. Platform 직경이 body 직경보다 큰 임플란트 중 실패한 임플란트는 없었다. 결론: 좁은 직경의 임플란트는 좁은 직경의 치조제에 안정적인 치료 결과를 나타낸다 사료된다.

이중대역(PCS/IMT-2000) 마이크로스트립 패치 안테나 설계 및 구조에 따른 SAR 분석 (SAR Analysis and Design the Microstrip Patch Antenna on Dual-Band(PCS/IMT-2000))

  • 최윤희;신호섭;김남;박주덕
    • 한국전자파학회논문지
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    • 제15권1호
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    • pp.12-20
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    • 2004
  • 본 논문에서는 PCS/IMT-2000 이동통신 전화기에 의해 인체 두부에 유기되는 SAR의 1 g 및 10 g 평균 첨두 값을 비교 분석하였다. 평면형 구조인 single-semi-disc MPA와 double-semi-disc MPA를 설계하고, 안테나 설계 파라미터에 따른 공진 특성을 분석하였다. 그 결과 중심주파수 2.0 ㎓에서 대역폭이 15.5 %, 31 %로 나타났다. 그리고 제안한 안테나와 동일한 공진 주파수를 갖는 모노폴 안테나를 설계하여 SAR 값을 비교ㆍ분석하였다. 폴더형 전화기에 부착된 double-semi-disc MPA에 의한 1 g 및 10 g 평균 첨두 SAR 값은 각각 0.811 W/kg과 0.507 W/kg으로 모노폴 안테나의 1.206 W/kg과 0.755 W/kg에 비해 약32.7 % 가량 낮은 것으로 나타났다. 평면형 구조의 안테나는 등방성 방사패턴을 나타내는 모노폴 안테나에 비해 인체 외부 방향으로 지향성 방사 패턴을 나타내어 인체 두부에 유기되는 SAR이 낮은 값으로 나타났다.

Characteristics of $Al_2O_3/TiO_2$ multi-layers as moisture permeation barriers deposited on PES substrates using ECR-ALD

  • 권태석;문연건;김웅선;문대용;김경택;박종완
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2009년도 제38회 동계학술대회 초록집
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    • pp.457-457
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    • 2010
  • Flexible organic light emitting diodes (F-OLEDs) requires excellent moisture permeation barriers to minimize the degradation of the F-OLEDs device. Specifically, F-OLEDs device need a barrier layer that transmits less than $10^{-6}g/m^2/day$ of water and $10^{-5}g/m^2/day$ of oxygen. To increase the life time of F-OLEDs, therefore, it is indispensable to protect the organic materials from water and oxygen. Severe groups have reported on multi-layerd barriers consisting inorganic thin films deposited by plasma enhenced chemical deposition (PECVD) or sputtering. However, it is difficult to control the formation of granular-type morphology and microscopic pinholes in PECVD and sputtering. On the contrary, atomic layer deoposition (ALD) is free of pinhole, highly uniform, conformal films and show good step coverage. Thus, $Al_2O_3/TiO_2$ multi-layer was deposited onto the polyethersulfon (PES) substrate by electron cyclotron resonance atomic layer deposition (ECR-ALD), and the water vapor transmission rates (WVTR) were measured. WVTR of moisture permeation barriers is dependent upon density of films and initial state of polymer surface. A significant reduction of WVTR was achieved by increasing density of films and by applying low plasma induced interlayer on the PES substrate. In order to minimize damage of polymer surface, a 10 nm thick $TiO_2$ was deposited on PES prior to a $Al_2O_3$ ECR-ALD process. High quality barriers were developed from $Al_2O_3$ barriers on the $TiO_2$ interlayer. WVTR of $Al_2O_3$ by introducing $TiO_2$ interlayer was recorded in the range of $10^{-3}g/m^2.day$ at $38^{\circ}C$ and 100% relative humidity using a MOCON instrument. The WVTR was two orders of magnitude smaller than $Al_2O_3$ barriers directly grown on PES substrate without the $TiO_2$ interlayer. Thus, we can consider that the $Al_2O_3/TiO_2$ multi-layer passivation can be one of the most suitable F-OLEDs passivation films.

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3 kW 무선 전력전송을 위한 전력 변환기 회로 특성 (The Power Converter Circuit Characteristics for 3 kW Wireless Power Transmission)

  • 황락훈;나승권;김진선;강진희
    • 한국항행학회논문지
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    • 제24권6호
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    • pp.566-572
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    • 2020
  • 무선 전력전송기에서 두 유도 코일 사이의 무선 전력전송 특성과 영향에 대해서 알아보고, 무선 전력전송 기술을 이용한 전력변환기 회로와 배터리 충·방전기 회로를 제안한다. 무선 전력전송기 및 무선 충전기의 장점은 기존의 플러그인 탑재형 유선 충전기(OBC; on-board charger) 대신 무선으로 전력을 전송하여 배터리에 전력 충전 시 사용자가 외부에서 전원을 연결 시키지 않고 무선으로 충전할 수 있는 점이다. 또한 무선충전의 이점은 2차 측 정류기의 회로와 수신 코일을 사용하여 에너지 효율 향상 효과를 가져올 수 있으나, 대용량의 원거리 무선충전 방식은 전송거리에 대한 한계가 있어 현재 많은 연구가 진행되고 있다. 비 접촉 방식의 전력 전송기의 전력을 전송 할 수 있는 송신부 인 1차측 코일과 수신부인 2차측 코일 및 하프브리지(half bridge) 직렬공진 컨버터를 적용한 무선 전력전송장치의 송신부 회로와 수신부 회로의 연구를 목적으로 무선충전시스템의 전력전송거리 향상을 위한 새로운 토폴로지를 적용하고, 각각의 거리에 따른 실험을 통해 8 cm 전송거리에서 출력 3 kW 일 때, 최대 효율(95.8%)을 확인 할 수 있었다.

아킬레스건 봉합 후 초음파에서 보이는 섬유 배열 양상과 임상적 요인과의 관계 (Correlation between the Fibrillar Pattern in Ultrasonography and Clinical Factors after Achilles Tendon Repair)

  • 최영진;안수형;배서영
    • 대한족부족관절학회지
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    • 제26권3호
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    • pp.123-129
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    • 2022
  • Purpose: To evaluate the correlation between the fibrillar pattern of the Achilles tendon on ultrasonography (US) and functional outcomes in patients who underwent open tendon repair after Achilles tendon rupture. Materials and Methods: Data of 44 patients who had been subjected to US at least 6 months after repair, during the period between July 2012 and July 2019 were reviewed. Those with bilateral tendon rupture, re-rupture, open injury, and chronic or insertional rupture, were excluded from the review. We divided them into two groups, the homogenous group (HoP) and the heterogenous group (HeP) based on the fibrillar pattern on US. We also divided the HoP into linear and wavy subgroups, and the HeP into no hypoechoic lesion and hypoechoic lesion subgroups. The rupture type of the Achilles tendon, radiographic factors including US and magnetic resonance images, patient-related, surgical factors, and clinical results at the last visit after repair were assessed retrospectively. Results: The tendon thickness was 11.4±1.7 mm in the HoP, and 14.5±3.0 mm in the HeP (p<0.001). A shredded pattern was observed in 17 cases (65.4%) in the HoP, and in 17 cases (94.4%) in the HeP (p=0.031). The mean value of the number of sutures used was 8.9±3.05 in the HoP and 11.39±1.75 in the HeP (p=0.001). The mean value of the difference in calf circumference was 0.9±0.67 cm in the HoP and 1.36±0.71 cm in the HeP (p=0.037). There were no statistically significant differences in the fibrillar patterns and patient-related factors. Conclusion: The fibrillar pattern observed after repair was correlated with the functional outcome and showed a significant relationship with the rupture pattern and the number of sutures used. Therefore, we suggest a careful individualized postoperative rehabilitation protocol to maximize functional outcomes by referring to the fibrillar pattern in US, especially in shredded ruptures.

딥러닝 기반 고속철도교량의 주행안전성 및 승차감 예측 (Running Safety and Ride Comfort Prediction for a Highspeed Railway Bridge Using Deep Learning)

  • 김민수;최상현
    • 한국전산구조공학회논문집
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    • 제35권6호
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    • pp.375-380
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    • 2022
  • 고속철도 교량은 열차 하중에 의한 공진으로 인한 동적응답 증폭의 위험이 존재하므로 설계기준에 따른 동적해석을 통한 주행안전성 및 승차감 검토를 반드시 수행하여야 한다. 그러나 주행안전성 및 승차감 산정 절차는 열차의 종류별로 임계속도를 포함하여 설계속도의 110km/h까지 10km/h 간격으로 동적해석을 일일이 수행해야 하므로 많은 시간과 경비가 소요된다. 이 연구에서는 딥러닝 알고리즘을 활용하여 별도의 동적해석 없이 주행안전성 및 승차감을 사전에 예측할 수 있는 딥러닝 기반 예측 시스템 개발하였다. 제안된 시스템은 철도교량의 열차별, 속도별 동적해석 결과를 학습한 후 학습 완료된 신경망을 기반으로 한 예측 시스템이며, 열차속도, 교량 특성 등의 입력파라미터에 따른 주행안전성 및 승차감 산정 결과를 사전에 예측할 수 있다. 제안된 시스템의 성능을 확인하기 위하여 단경간 직선 단순보 교량을 대상으로 한 주행안전성 및 승차감 예측을 수행하였고, 주행안전성 및 승차감 산정을 위한 상판 연직변위 및 상판 연직가속도를 높은 정확도로 예측할 수 있음을 확인하였다.

PSC-box 철도교량의 KTX 및 EMU 고속열차에 대한 동적 응답 특성 분석 (Analysis of Dynamic Response Characteristics for KTX and EMU High-Speed Trains on PSC-Box Railway Bridges)

  • 한만석;송민규;신수봉;이종한
    • 한국구조물진단유지관리공학회 논문집
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    • 제28권2호
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    • pp.61-68
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    • 2024
  • 국내 경부선 및 호남선의 고속철도교량은 대부분 PSC-box 형식으로 설계되어 있고, 경간장35~40m인 경우 약 4~5Hz 정도의 1차 휨 고유진동수를 가지고 있다. 이때 KTX 고속열차가 290~310 km/h 속도로 주행할 경우, 열차에 의한 가진 진동수가 교량의 1차 휨 고유진동수에 근접하면서 공진 유사 현상이 발생하게 된다. KTX와 함께 향후 운행예정인 EMU-320 고속열차의 증속에 대해서도 철도교량의 동적 응답을 통한 안전성 분석이 필요한 상황이다. 본 연구에서는 실제 철도교량에서 계측된 응답을 기반으로 구조해석모델 개선 기법을 통해 대상 철도교량과 거동이 유사한 해석모델을 구현하였다. 개선된 구조해석모델은 고속철도교량에 KTX가 주행할 때 계측된 응답과 비교하여 검증하고, 이를 통해 KTX와 EMU-320 고속열차가 증속할 경우 동적 응답 특성을 분석하였다. 또한, 결과적으로, 교량 중앙부의 최대 수직변위와 가속도의 변화는 철도설계기준과 비교하여 주행 안전성을 평가하였다.

Neuroimaging Findings in Patients with COVID-19: A Systematic Review and Meta-Analysis

  • Pyeong Hwa Kim;Minjae Kim;Chong Hyun Suh;Sae Rom Chung;Ji Eun Park;Soo Chin Kim;Young Jun Choi;Young Jun Choi;Ho Sung Kim;Jung Hwan Baek;Choong Gon Choi;Sang Joon Kim
    • Korean Journal of Radiology
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    • 제22권11호
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    • pp.1875-1885
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    • 2021
  • Objective: Central nervous system involvement in coronavirus disease 2019 (COVID-19) has been increasingly reported. We performed a systematic review and meta-analysis to evaluate the incidence of radiologically demonstrated neurologic complications and detailed neuroimaging findings associated with COVID-19. Materials and Methods: A systematic literature search of MEDLINE/PubMed and EMBASE databases was performed up to September 17, 2020, and studies evaluating neuroimaging findings of COVID-19 using brain CT or MRI were included. Several cohort-based outcomes, including the proportion of patients with abnormal neuroimaging findings related to COVID-19 were evaluated. The proportion of patients showing specific neuroimaging findings was also assessed. Subgroup analyses were also conducted focusing on critically ill COVID-19 patients and results from studies that used MRI as the only imaging modality. Results: A total of 1394 COVID-19 patients who underwent neuroimaging from 17 studies were included; among them, 3.4% of the patients demonstrated COVID-19-related neuroimaging findings. Olfactory bulb abnormalities were the most commonly observed (23.1%). The predominant cerebral neuroimaging finding was white matter abnormality (17.6%), followed by acute/subacute ischemic infarction (16.0%), and encephalopathy (13.0%). Significantly more critically ill patients had COVID-19-related neuroimaging findings than other patients (9.1% vs. 1.6%; p = 0.029). The type of imaging modality used did not significantly affect the proportion of COVID-19-related neuroimaging findings. Conclusion: Abnormal neuroimaging findings were occasionally observed in COVID-19 patients. Olfactory bulb abnormalities were the most commonly observed finding. Critically ill patients showed abnormal neuroimaging findings more frequently than the other patient groups. White matter abnormalities, ischemic infarctions, and encephalopathies were the common cerebral neuroimaging findings.