• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제15권7호
• /
• pp.2589-2609
• /
• 2021

Segment routing (SR) is a highly implementable approach for traffic engineering (TE) with high flexibility, high scalability, and high stability, which can be established upon existing network infrastructure. Thus, when a network failure occurs, it can leverage the existing rerouting methods, such as rerouting based on Interior Gateway Protocol (IGP) and fast rerouting with loop-free alternates. To better exploit these features, we propose a high-performance and easy-to-deploy method SRUF (Segment Routing under Uncertain Failures). The method is inspired by the Value-at-Risk (VaR) theory in finance. Just as each investment risk is considered in financial investment, SRUF also considers each traffic distribution scheme's risk when forwarding traffic to achieve optimal traffic distribution. Specifically, SRUF takes into account that every link may fail and therefore has inherent robustness and high availability. Also, SRUF considers that a single link failure is a low-probability event; hence it can achieve high performance. We perform experiments on real topologies to validate the flexibility, high-availability, and load balancing of SRUF. The results show that when given an availability requirement, SRUF has greater load balancing performance under uncertain failures and that when given a demand requirement, SRUF can achieve higher availability.

• Journal of Korean Neurosurgical Society
• /
• 제62권5호
• /
• pp.603-609
• /
• 2019

Objective : The purpose of this retrospective study was to determine which of the proximal adjacent segment disease (ASD) and distal ASD was more prevalent and what parameters is more related to ASD in proximal levels and distal levels after more than 2 levels fusions. Methods : The medical records were reviewed retrospectively for 856 cases. A total of 66 cases of ASD were enrolled. On preop magnetic resonance imaging, disc degeneration was measured at the upper and lower parts of surgically treated levels and confirmed by the commonly used Pfirrmann grade. Segmental flexibility in sagittal plane was embodied in segment range of motion (ROM) obtained through flexion and extension X-ray before surgery. Coronal angle was recorded as methods Cobb's angle including fusion levels preoperatively. For the comparison of categorical variables between two independent groups, the chi-square test and Fisher exact test were performed. Results : Proximal ASD and distal ASD were 37/856 (4.32%) and 29/856 (3.39%), respectively. The incidence of proximal ASD was relatively high but insignificant differences. In comparison between ASD group and non ASD group, proximal Pfirmman was higher in proximal ASD and distal Pfirmman was higher in distal ASD group (p=0.005, p<0.008, respectively). However, in the ROM, proximal ROM was higher in proximal ASD, but distal ROM was not different between the two groups (p<0.0001, p=0.995, respectively). Coronal angle was not quite different in both groups (p=0.846). Conclusion : In spite of higher frequency in ASD in proximal level in spinal fusion, it is not clear that incidence of ASD in proximal level is not higher than that of distal ASD group in more than 2 level thoracolumbar fusions. Not only Pfirrmann grade but also proximal segmental ROM is risk factor for predicting the occurrence of ASD in patients more than 2 level of thoracolumbar spine fusion operation excluding L5S1.

• Structural Engineering and Mechanics
• /
• 제56권2호
• /
• pp.169-188
• /
• 2015

There are two types of nonlinear analysis methods for building frameworks depending on the method of modeling the plastification of members including lumped plasticity and distributed plasticity. The lumped plasticity method assumes that plasticity is concentrated at a zero-length plastic hinge section at the ends of the elements. The distributed plasticity method discretizes the structural members into many line segments, and further subdivides the cross-section of each segment into a number of finite elements. When a reinforced concrete member experiences inelastic deformations, cracks tend to spread form the joint interface resulting in a curvature distribution. The program IDARC includes a spread plasticity formulation to capture the variation of the section flexibility, and combine them to determine the element stiffness matrix. In this formulation, the flexibility distribution in the structural elements is assumed to be the linear. The main objective of this study is to evaluate the accuracy of linear flexibility distribution assumed in the spread inelasticity model. For this purpose, nonlinear analysis of two reinforced concrete frames is carried out and the linear flexibility models used in the elements are compared with the real ones. It is shown that the linear flexibility distribution is incorrect assumption in cases of significant gravity load effects and can be lead to incorrect nonlinear responses in some situations.

• 한국콘텐츠학회:학술대회논문집
• /
• 한국콘텐츠학회 2005년도 추계 종합학술대회 논문집
• /
• pp.601-607
• /
• 2005

본 논문에서는 대역폭과 지연 파라미터를 참조하여 PG내의 토폴로지 정보를 요약하는 기법으로 라인 세그먼트를 이용하여 경계노드 사이의 다중 경로 정보를 요약하였다. 이를 위해 토폴로지 요약 정보를 줄이고 다중링크 요약에 유연성을 부여하기 위하여 대역폭과 지연의 한 쌍으로 구성된 두 개의 라인 세그먼트를 이용하는 수정된 라인 세그먼트 기법을 제안하였다. 시뮬레이션 분석결과 제안된 star TA 기법이 기존의 기법보다 성능이 향상됨을 알 수 있었다.

• Structural Engineering and Mechanics
• /
• 제41권2호
• /
• pp.285-297
• /
• 2012

An inverse approach is presented for calculating the flexibility coefficient of open-side cracks in the cross sectional of beams. The cracked cross section is treated as a massless rotational spring which connects two segments of the beam. Based on the Euler-Bernoulli beam theory, the differential equation governing the forced vibration of each segment of the beam is written. By using a mathematical manipulation the time dependent differential equations are transformed into the static substitutes. The crack characteristics are then introduced to the solution of the differential equations via the boundary conditions. By having the time history of transverse response of an arbitrary location along the beam, the flexibility coefficient of crack is calculated. The method is applied for some cracked beams with solid rectangular cross sections and the results obtained are compared with the available data in literature. The comparison indicates that the predictions of the proposed method are in good agreement with the reported data. The procedure is quite general so as to it can be applicable for both single-side crack and double-side crack analogously. Hence, it is also applied for some test beams with double-side cracks.

• 정보처리학회논문지C
• /
• 제11C권5호
• /
• pp.645-652
• /
• 2004

본 논문에서는 대역폭과 지연 파라미터를 참조하여 PG내의 토폴로지 정보를 하는 기법으로 라인 세그먼트를 이용하여 경계노드 사이의 다중 경로 정보를 하였다. 제안된 star 토폴로지 기법에서는 모든 경로를 찾는 대신 홉 카운트 기반의 깊이 우선 방식을 사용하여 효율적으로 다중 경로를 탐색할 수 있도록 하였다. 이를 위해 토폴로지 정보를 줄이고 다중링크 에 유연성을 부여하기 위하여 대역폭과 지연의 한 쌍으로 구성된 두 개의 라인 세그먼트를 이용하는 수정된 라인 세그먼트 기법을 제안하였다. 그리고, 이를 기존의 star 토폴로지에 적용한 효율적인 토폴로지 기법을 제안하였다. 제안된 기법의 성능을 평가하기 위해 기존의 star 기법과 호 성공율, 접근시간 및 크랭크 백율에 대하여 컴퓨터 시뮬레이션을 통해 비교 분석하였다. 시뮬레이션 분석결과 제안된 star TA 기법이 기존의 기법보다 성능이 향상됨을 알 수 있었다.

• The Journal of Korean Physical Therapy
• /
• 제35권2호
• /
• pp.37-42
• /
• 2023

Purpose: Compared to cities, rural areas are in a medical blind spot and face difficulties in accessing medical services due to inconvenient transportation facilities, lack of medical facilities, and the heavy burden of medical expenses. This study was carried out to identify the problems relating to the musculoskeletal system of the elderly in rural and fishing villages, which are medically vulnerable areas, and sought to present a regionally differentiated healthcare model. Methods: The study was conducted in 80 elderly people in two rural villages and two fishing villages after seeking inputs regarding medically vulnerable groups in the Gyeongnam Province. Postural balance and muscle flexibility were assessed and postural evaluation was conducted to identify musculoskeletal problems and gait stability. Strength and range of motion for each body segment were assessed for evaluating functional motion. Results: The elderly in both rural areas showed forward head posture characteristics. The strength level of the elderly in both rural areas was higher than the average, but their flexibility and balance ability were lower than the average. Conclusion: The musculoskeletal problems of the elderly in rural and fishing villages in this study did not show regional characteristics according to the area of residence. However, overall flexibility and balance ability appeared to be reduced. Therefore, a new management model connecting the region and the university is necessary in preparation for the coming era of community care.

• 대한정형도수물리치료학회지
• /
• 제27권2호
• /
• pp.9-15
• /
• 2021

Background: This study investigated the effects of sustained natural apophyseal glides (SNAGS) technique on lower back pain and pain disability among university students with lower back pain. Methods: A total thirty 20~30 year old university students with lower back pain were divided into two groups. A lumbar flexibility exercise was applied to the control group (n=15). The SNAGS technique group (n=15) received L1~L4 segment mobilization using SNAGS technique. Intervention was implemented for 20 minutes, 3 times a week for 3 weeks. The SNAGS were performed using belt with flexion and extension, whereas lumbar flexibility exercise included lumbar flexion and extension. Lower back disability was measured using the Korean Oswestry disability index (KODI), and pain sensitivity was measured by pain pressure threshold (PPT). The groups were assessed for lower back pain disability and pain, before and after the intervention. Results: There were significant improvements in both the KODI and PPT of the SNAGS technique group (p<.05), while the lumbar flexibility exercise group showed no significant change (p>.05). In addition, the SNAGS technique group had a statistically significant difference in KODI and PPT compared to the lumbar flexibility exercise group (p<.05). Conclusion: SNAGS technique is more effective than lumbar spine joint flexibility exercise in the improvement of lower back pain disability and pain among university students with lower back pain.

• Journal of Chest Surgery
• /
• 제26권8호
• /
• pp.664-666
• /
• 1993

A technique for insertion of a long silicone T-tube in patient with critical stenosis and high-risk resection and primary anastomosis of long segment of the distal trachea is presented. It was not easy to insert a long T-tube by existing methods because of flexibility of a T-tube and tightness of stenosis. So we used a silastic endotracheal tube and guiding wire as stylet of a T-tube. During insertion, ventilation was normally maintained through the lumen of endotracheal tube. This provided rapid relief from airway obstruction and asphyxation and is a easy, safe and effective method to restore patency of the major airways.

• 대한정형도수물리치료학회지
• /
• 제13권2호
• /
• pp.12-20
• /
• 2007

The purpose of this study was designed to find out the effectiveness of vertebral segment instability, muscle fatigue response on lumbar spine after apply lumbosacral stabilization exercise program to 4 patients with chronic low back pain and for 12 weeks. In this study, the lumbar spine motion with blind by MedX test machine and the difference of instability to lumbar vertebra segments in flexion, extension test of standing position and spinal load test(Matthiass Test) by Spinal Mouse. The stabilization exercise program was applied 2 times a week for 12 weeks in hospital and 2 times a day for 20 minutes at home. The results of the present study were as follows: 1. Instability test of lumbar vertebra segment is 2 type differential angle test between vertebrae segment and loading test of spine(matthiass) by Spinal Mouse. It appeared to improve stability of segments in sagittal plane after applying program. So lumbar spine curve increased lordosis toward anterior and was improved of the lumbar spine flexibility in flexion and extension. Specially, in matthiass test, (-) value was increased between lumbar vertebra segment when was the load on spine. And so applying stability improved after program. 2. Fatigue response test(FRT) results, in male, was raised muscle fatigue rate during increase weight, on the other hand female appeared lower than male. As a results, lumbosacral stabilization exercise was aided to improvement of lumbar spine vertebra segments stabilization. Spine instability patients will have a risk when in lifting a load or working with slight flexion posture during the daily of living life and it is probably to increase recurrence rate. Thus, not only lumbar extension muscle strength but also stability of vertebra segments in lumbar spine may be very important.