• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2007년도 정기 학술대회 논문집
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• pp.757-762
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• 2007

The lining segment which is the main structure of the shield tunnel consists of joints, not continua. Past international and domestic design data have been commonly used for design practices without specific verification about the structural analysis model, design load, and affection of the soil constant of the lining segment. In this study, the propriety is estimated through the comparison between analytical solution and numerical solution for segment analysis and design models of the shield tunnel which is being used internationally and domestically. As a result, the full. circumferential beam jointed spring model (1R-S0) is suggested by considering aspects of convenient use, application to field condition, and accuracy of analysis result. With suggested model, the parameter analysis was conducted for joint stiffness, ground rigidity, joint distribution, and joint number.

• Journal of Korean Neurosurgical Society
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• 제57권2호
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• pp.108-113
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• 2015

Objective : Although the L5-S1 has distinct structural features in comparison with other lumbar spine segments, not much is known about adjacent segment degeneration (ASD) at the L5-S1 segment. The aim of study was to compare the incidence and character of ASD of the cephalad and L5-S1 segments after L5 floating lumbar fusion. Methods : From 2005 to 2010, 115 patients who underwent L5 floating lumber fusion were investigated. The mean follow-up period was 46.1 months. The incidence of radiological and clinical ASD of the cephalad and the L5-S1 segments was compared using survival analysis. Risk factors affecting ASD were analyzed using a log rank test and the Cox proportional hazard model. Results : Radiological ASD of the L5-S1 segment had a statistically significant higher survival rate than that of the cephalad segment (p=0.001). However, clinical ASD of the L5-S1 segment was significantly lower survival rates than that of the cephalad segment (p=0.038). Risk factor analysis showed that disc degeneration of the cephalad segment and preoperative spinal stenosis of the L5-S1 segment were risk factors. Conclusion : In L5 floating fusion, radiological ASD was more common in the cephalad segment and clinical ASD was more common in the L5-S1 segment. At the L5-S1 segment, the degree of spinal stenosis appears to be the most influential risk factor in ASD incidences, unlike the cephalad segment.

• 한국터널지하공간학회 논문집
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• 제17권6호
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• pp.695-702
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• 2015

원심모형시험은 최근의 기계적, 이론적 발전에 따라 그 활용도와 정확성이 높아지고 있다. 원심모형시험은 원지반 응력을 효과적으로 재현할 수 있으므로 주위 지반 또는 암반과 상호작용을 하는 터널과 같은 지하구조물의 거동을 모사하기 적합하다. 본 연구에서는 병렬 터널의 지진시 동적 거동을 원심모형시험을 통하여 분석하였다. 터널 모델링시 지진에 의해 발생하는 최대 가속도 저감을 위하여 Flexible segment를 고려하였으며 Flexible segment의 두께가 얇은 경우와 두꺼운 경우를 각각 고려하였다. 시험 결과 Flexible segment의 지진시 터널 구조물에 발생하는 최대 가속도 저감 효과를 확인하였다. 그러나 Flexible segment가 얇은 경우 단주기파 적용시 최대가속도의 저감효과는 없었고, 두꺼운 경우 기반암 가속도가 클 경우 보다 효과적임을 확인하였다. 또한 동일 모델에 대하여 3차원 수치해석을 수행하여 지진시 거동을 파악한 결과, 시험 결과와 유사한 경향을 보임을 확인할 수 있었다.

• Journal of Medicine and Life Science
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• 제16권1호
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• pp.1-5
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• 2019

Our purpose was to evaluate usefulness of the contrast-enhanced 3 dimensional fluid attenuated inversion recovery (3D-FLAIR) technique of half brain volume to diagnose the patients with facial neuritis based on segment-based analysis. We assessed retrospectively 17 consecutive patients who underwent brain MR imaging at 3 tesla for facial neuritis: 11 patients with idiopathic facial neuritis and 6 with herpes zoster oticus. Contrast enhanced 3D-FLAIR sequences of the half brain volume were analyzed and 3D T1-weighted sequence of the full brain volume were used as the base-line exam. Enhancement of the facial nerve was determined in each segment of 5 facial nerve segments by two radiologists. Sensitivity, specificity and accuracy of enhancement of each segment were assessed. The authors experienced a prompt fuzzy CSF enhancement in the fundus of the internal auditory canal in patients with enhancement of the canalicular segment. Interobserver agreement of CE 3D-FLAIR was excellent(${\kappa}$-value 0.885). Sensitivity, specificity, and accuracy of each segment are 1.0, 0.823, 0.912 in the canalicular segment; 0.118, 1.0, 0.559 in the labyrinthine segment; 0.823, 0.294, 0.559 in the anterior genu; 0.823, 0.529, 0.676 in the tympanic segment; 0.823, 0.235, 0.529 in the mastoid segment, respectively. In addition, those of prompt fuzzy enhancement were 0.647, 1.0, and 0.824, respectively. Incidence of prompt fuzzy enhancement with enhancement of the canalicular segment was 11 sites(55%): 6 (54.5%) in idiopathic facial neuritis and 5 (83.3%) in herpes zoster. Enhancement of the canalicular segment and prompt fuzzy enhancement on CE 3D-FLAIR was significantly correlated with occurrence of facial neuritis (p<0.001). CE 3D-FLAIR technique of the half brain volume is useful to evaluate the patients with facial neuritis as an adjunct sequence in addition to contrast-enhanced 3D T1-weighted sequence. On segment-based analysis, contrast enhancement of the canalicular segment is the most reliable. Prompt fuzzy enhancement is seen in not only herpes zoster, but in idiopathic facial neuritis.

• 한국터널지하공간학회 논문집
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• 제19권6호
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• pp.905-913
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• 2017

세그먼트 라이닝 설계시 고려하는 하중은 자중, 연직하중, 수평하중, 지반반력, 수압, 뒤채움 주입압, 부력 등이 있으며, 이 가운데 토압과 수압은 세그먼트 라이닝 설계시 콘크리트 강도, 세그먼트 라이닝의 두께 및 철근량 등을 결정하는데 가장 큰 영향을 미치는 주요 인자이다. 따라서 본 연구에서는 쉴드터널 시공단계별 계측결과를 토대로 세그먼트 라이닝에 발생하는 휨모멘트 계산하였으며, 이를 역해석 결과와 비교분석을 통하여 세그먼트 라이닝에 작용하는 토압 등을 분석하였다.

• 터널과지하공간
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• 제21권6호
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• pp.427-438
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• 2011

세그먼트 라이닝은 쉴드터널에서 공사 중의 안정성을 확보하고 영구적인 터널 라이닝으로 사용되는 중요한 구조체이다. 더욱이 세그먼트 라이닝은 쉴드터널의 공사비에서 가장 큰 비중을 차지하기 때문에, 세그먼트의 경제성 향상을 위한 기술적인 개선 노력들이 이루어지고 있다. 따라서 본 연구에서는 경제적인 세그먼트 라이닝의 시공을 위한 고성능 세그먼트의 최신 개발 동향을 조사 및 분석하여 세그먼트의 기술개발 방향을 제시하고자 하였다. 또한 설계단계에서 세그먼트의 주요 설계사항들을 개략적으로 추정하는데 활용하기 위하여, 전 세계 2,100여개 세그먼트 자료들을 조사하고 이를 기반으로 세그먼트 라이닝 외경, 세그먼트 주요 형상치수 및 세그먼트 재질들에 대한 통계분석을 실시하였다.

• 한국항해항만학회지
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• 제34권7호
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• pp.553-558
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• 2010

This study presents the optimization design process of a segment ball valve that involves the reduction of the flow resistance coefficient and the satisfaction of the strength requirement. Numerical analysis of fluid flow and structural analysis have been performed to predict the flow resistance coefficient and the maximum stress of a segment ball valve. In this study, a segment ball valve incorporating the advantages of a ball valve and a butterfly valve has been devised. In general, ball valves are installed in a pipe system where tight shut off is required. Butterfly valves having smaller end-to-end dimension than ball valve can be installed in narrow spaces in a pipe system. The metamodels for the shape design of a segment ball valve are built by the response surface method and the Kriging interpolation model.

• 한국정보과학회논문지:소프트웨어및응용
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• 제34권12호
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• pp.1065-1074
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• 2007

기존의 참조서명과 입력서명을 비교하는 방법 중 분절 단위 비교 방법은 전역적 비교와 점 단위 비교 방법과 비교하여 우수한 장점을 가지고 있다. 그러나 분절 단위 비교 방법은 인식률과 직접적인 관계가 있는 분절의 불안정 문제점이 있다. 이러한 문제점을 해결하기 위하여 본 논문에서는 분절단위 방법 외에 선형판별분석에 의한 매칭방법을 고려한 서명 검증 기법을 제안한다. 최종 검증단계에서 두 개의 독립모델을 효과적으로 융합할 수 있는 확률기반의 베이지안 분류기를 적용하였다 다양한 서명데이타를 이용하여 실험한 결과 제안된 기법은 분절단위 기반 구간분할매칭 기법에 비해 우수한 성능을 나타냈다.

• 한국전문물리치료학회지
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• 제10권1호
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• pp.63-76
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• 2003

This research was performed to compare spinal segment motion angle between low back pain (LBP) group and painless group during trunk flexion-extension and to investigate the effect of transversus abdominis strengthening exercise on spinal segment motion angle in LBP group. Nine subjects with LBP and ten subjects without LBP participated. Transversus abdominis strengthening exercise was performed in LBP group for three weeks, and spinal segment motion angles were compared before and after the exercise performance. Spinal segment motion angles were measured both in sitting and standing position. Results were as followed: 1) Subjects' average age was 24.79 years, height was 167.84 cm, and weight was 59.95 kg. 2) Spinal segment motion angle of T10/l1 was significantly higher in LBP group compared with painless group (p<.05) in sitting position during trunk flexion-extension. 3) In sitting position, whereas entire lumbar segment motion angles were lower in LBP group compared with painless group (p<.05), angle of L4/5 was higher in LBP group compared with painless group (p<.05). 4) There was no significant difference in thoracic segment motion angle in standing position. 5) After three weeks of transversus abdominis strengthening exercise, thoracic segment motion angle increased both in sitting and standing position (p<.05). 6) In painless group, there was no significant difference in entire spinal segment motion angles in sitting and standing position (p>.05). When spinal segment motion angles were compared between sitting and standing position, there were slight differences. In sitting position, there was no difference in spinal segment motion angle between LBP group and painless group while hip joint motion angle and sacral inclination angle of LBP group was lower than those of painless group (p<.05). In standing position, lumbar segment motion angle was significantly lower in LBP group than that of painless group. Transversus abdominis strengthening exercise influenced thoracic segment motion angle more significantly than lumbar segment motion angle.

• Korean Journal of Radiology
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• 제19권6호
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• pp.1140-1146
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• 2018

Objective: To compare the spinal enumeration methods that establish the first lumbar vertebra in patients with spinal variants. Materials and Methods: Of the 1446 consecutive patients who had undergone computed tomography of the spine from March 2012 to July 2016, 100 patients (62 men, 38 women; mean age, 47.9 years; age range, 19-88 years) with spinal variants were included. Two radiologists (readers 1 and 2) established the first lumbar vertebra through morphologic analysis of the thoracolumbar junction, and labeled the vertebra by counting in a cranial-to-caudal manner. Inter-observer agreement was established. Additionally, reader 1 detected the 20th vertebra under the assumption that there are 12 thoracic vertebra, and then classified it as a thoracic vertebra, lumbar vertebra, or thoracolumbar transitional vertebra (TLTV), on the basis of morphologic analysis. Results: The first lumbar vertebra, as established by morphologic analysis, was labeled by each reader as the 21st segment in 65.0% of the patients, as the 20th segment in 31.0%, and as the 19th segment in 4.0%. Inter-observer agreement between the two readers in determining the first lumbar vertebra, based on morphologic analysis, was nearly perfect (${\kappa}$ value: 1.00). The 20th vertebra was morphologically classified as a TLTV in 60.0% of the patients, as the first lumbar segment in 31.0%, as the second lumbar segment in 4.0%, and as a thoracic segment in 5.0%. Conclusion: The establishment of the first lumbar vertebra using morphologic characteristics of the thoracolumbar junction in patients with spinal variants was consistent with the morphologic traits of vertebral segmentation.