3,948 research outputs found
Sy Montgomery and Matt Patterson: 2024 Cook Prize Gold Medal Winners
No full textAuthor Sy Montgomery and illustrator Matt Patterson\u27s video for The Book of Turtles (Clarion)https://educate.bankstreet.edu/cook/1012/thumbnail.jp
Large-eddy simulation of turbulent flow in a concentric annulus with rotation of an inner cylinder
No full textLarge-eddy simulations of the turbulent flow in a concentric annulus with inner wall rotation were performed at Re-Dh = 8900 for three rotation rates (N = 0.2145, 0.429 and 0.858). The main emphasis of this work was on the destabilization of the near-wall turbulent structures due to rotation of the inner wall. The turbulent structures close to the inner wall were scrutinized by computing the lower-order statistics. The anisotropy invariant map for the Reynolds stress tensor and the invariant function revealed that rotation of the inner wall altered the anisotropy of the turbulent structure. The probability density functions of the velocity fluctuations and the splat/anti-splat process were examined to create a more complete picture of the contributions of the flow events to turbulent production. The present numerical results indicate that the alteration of the turbulent structures can be attributed to the destabilizing effect of rotation of the inner wall, which gives rise to an augmentation of sweep and ejection events. (C) 2004 Elsevier Inc. All rights reserved
Direct numerical simulation of turbulent concentric annular pipe flow - Part 2: Heat transfer
No full textA direct numerical simulation is performed for turbulent heat transfer in a concentric annulus at Re-Dh = 8900 and Pr = 0.71 for two radius ratios (R-1/R-2 = 0.1 and 0.5) and wall heat flux ratio q* = 1.0. Main emphasis is placed on the transverse curvature effect on near-wall turbulent thermal structures. Near-wall turbulent thermal structures close to the inner and outer walls are scrutinized by computing the lower-order statistics. The fluctuating temperature variance and turbulent heat flux budgets are illustrated to confirm the results of the lower-order statistics. Probability density functions of the splat/anti-splat process are investigated to analyze the transverse curvature effect on the strong relationship between sweep and splat events. The present numerical results show that the turbulent thermal structures near the outer wall are more activated than those near the inner wall, which may be attributed to the different vortex regeneration processes between the inner and outer walls. (C) 2003 Elsevier Science Inc. All rights reserved
IDENTIFICATION OF FUZZY RELATIONAL MODEL AND ITS APPLICATION TO CONTROL
No full textIn the cases of control systems where physical mechanisms are not well known due to high complexity and nonlinearity, a fuzzy relational model may be useful. In this paper, we propose a recursive parameter tuning algorithm for the identification of fuzzy relational model for an unknown dynamic system. Furthermore, using the fact that a dynamic system is represented by the relational strength between a few reference input and output fuzzy sets in the fuzzy relational model, we construct a control input fuzzy set inducing a desired output fuzzy set by calculating the possibility between the model output and the desired output fuzzy set for the control purpose. Simulation results show the usefulness of the proposed identification and control algorithms
Comprehensive clinical evaluation of deep learning-based auto-segmentation for radiotherapy in patients with cervical cancer
No full textBackground and purpose: Deep learning-based models have been actively investigated for various aspects of radiotherapy. However, for cervical cancer, only a few studies dealing with the auto-segmentation of organs-at-risk (OARs) and clinical target volumes (CTVs) exist. This study aimed to train a deep learning-based auto-segmentation model for OAR/CTVs for patients with cervical cancer undergoing radiotherapy and to evaluate the model’s feasibility and efficacy with not only geometric indices but also comprehensive clinical evaluation. Materials and methods: A total of 180 abdominopelvic computed tomography images were included (training set, 165; validation set, 15). Geometric indices such as the Dice similarity coefficient (DSC) and the 95% Hausdorff distance (HD) were analyzed. A Turing test was performed and physicians from other institutions were asked to delineate contours with and without using auto-segmented contours to assess inter-physician heterogeneity and contouring time. Results: The correlation between the manual and auto-segmented contours was acceptable for the anorectum, bladder, spinal cord, cauda equina, right and left femoral heads, bowel bag, uterocervix, liver, and left and right kidneys (DSC greater than 0.80). The stomach and duodenum showed DSCs of 0.67 and 0.73, respectively. CTVs showed DSCs between 0.75 and 0.80. Turing test results were favorable for most OARs and CTVs. No auto-segmented contours had large, obvious errors. The median overall satisfaction score of the participating physicians was 7 out of 10. Auto-segmentation reduced heterogeneity and shortened contouring time by 30 min among radiation oncologists from different institutions. Most participants favored the auto-contouring system. Conclusion: The proposed deep learning-based auto-segmentation model may be an efficient tool for patients with cervical cancer undergoing radiotherapy. Although the current model may not completely replace humans, it can serve as a useful and efficient tool in real-world clinics
中正中学戏剧研究会 （1947-1970） = Chung Cheng High School Drama Club (1947-1970)
No full text中正中学戏剧研究会在新马戏剧活动以及学生戏剧运动中扮演着举足轻重的角色。从1947年至1970年，中正剧研会几乎每一年都有演出，也拥有当时大众公认的高演出水平。本论文探讨中正剧研会是什么时候创立的，到底是战前 1940 或 1941 年，还是前人学者所普遍认为的 1947 年。本文介绍中正剧研会从创立时期至冬眠时期，即 1947 年至 1970 年的种种课题，例如：组织性质、剧研会的推动人、演出剧目，以及当时剧评人对于中正剧研会演出后所关心的课题。以中正剧研会的背景作为基础，本论文进一步介绍中正剧研会所培育出的人才的社会参与与贡献。他们除了在戏剧方面有优异的成绩之外，他们也热心推动其他领域，如电视与广播电台。Chung Cheng High School Drama Club has been playing an important role in Singapore’s drama activities and student drama activities especially from 1947 to 1970. Chung Cheng Drama Club had public performances almost every year, and was credited with high performing standards.This thesis aims to discuss the establishment year of Chung Cheng High School Drama Club. Previous researchers generally believed that Chung Cheng Drama Club was established in 1947, but there are evidences from other sources which show that it could be in 1940 or 1941. This thesis will be an introduction of different topics regarding Chung Cheng Drama Club; such as the nature of the Club, people who launched the Club, the plays performed, as well as critics’ reviews. Other than having outstanding results in theatre works, members of Chung Cheng Drama Club are also active in other sectors, like television and radio broadcast. This thesis will focus on their participation and the contribution in the society.Bachelor of Art
Direct numerical simulation of turbulent concentric annular pipe flow - Part 1: Flow field
No full textA direct numerical simulation is performed for a turbulent concentric annular pipe flow at Re-Dh = 8900 for two radius ratios (R-1/R-2 = 0.1 and 0.5). Main emphasis is placed on the transverse curvature effect on near-wall turbulent structures. Near-wall turbulent structures close to the inner and outer walls are scrutinized by computing the lower-order and higher-order statistics. The Reynolds stress budgets are illustrated to confirm the results of the lower-order statistics. A quadrant analysis of the Reynolds shear stress is explored to develop a sufficiently complete picture of the contribution of flow events to turbulence production (consumption). Probability density functions of the inclination angles of the projected vorticity vectors are investigated to analyze the transverse curvature effects on the orientation of the vorticity field. The present numerical results show that the turbulent structures near the outer wall are more activated than those near the inner wall, which may be attributed to the different vortex regeneration processes between the inner and outer walls. (C) 2002 Elsevier Science Inc. All rights reserved
An Investigation of the Effect of Virtual Reality on Alleviating Anxiety in Patients With Breast Cancer Undergoing Radiation Therapy: A Randomized Controlled Trial
No full textPurpose: The aim of this study was to evaluate the anxiety-reducing effects of virtual reality (VR) on patients with breast cancer undergoing adjuvant radiation therapy (RT). Methods and Materials: This randomized controlled trial was conducted among patients with breast cancer receiving RT at a single institution. Of 196 enrolled and randomized patients, 97 were assigned to a VR explanation group (intervention) and 99 were assigned to the standard-of-care group (control). Anxiety levels were measured using the Amsterdam Preoperative Anxiety and Information Scale (APAIS) as the primary endpoint and the State-Trait Anxiety Inventory (STAI) and Linear Analogue Scale Assessment (LASA) as secondary endpoints. Knowledge of the RT procedure, patient satisfaction, and time spent for counseling were also assessed. Results: Intervention significantly reduced patient anxiety immediately, not only on the primary endpoint, APAIS, but also on the STAI and LASA anxiety scales. Specifically, in the intervention group, there were immediate reductions of 26.0%, 16.1%, and 55.8% for APAIS, STAI, and LASA, respectively, whereas in the control group, the respective reductions were 8.1%, 8.5%, and 13.7%. Among the 3 anxiety scales, long-term anxiety reduction was observed only when anxiety was measured by LASA. Subgroup analyses showed that the effect on anxiety did not differ based on the physician, baseline anxiety level, use of hormone therapy, or health literacy. The intervention also significantly improved knowledge of the RT procedure (81.9/100 vs 76.8/100; P = .006) and patient satisfaction with the explanation manner (6.56 vs 5.72; P < .001) compared with the control group. Conclusions: Immersive VR applied to the current procedure reduces anxiety during RT planning for patients with breast cancer. Further research is necessary to investigate the long-term effects of VR on anxiety
Design of a LiNbO3 ribbon waveguide for efficient difference-frequency generation of terahertz wave in the collinear configuration
No full textWe propose and investigate a ribbon waveguide for difference-frequency generation of terahertz (THz) wave from infrared light sources. The proposed ribbon waveguide is composed of a nonlinear optic crystal and has a thickness less than the wavelength of the THz wave to support the surface-wave mode in the THz region. By utilizing the waveguide dispersion of the surface-wave mode, the phase matching condition between infrared pump, idler and THz waves can be realized in the collinear configuration. Owing to the weak mode confinement of the THz wave, the absorption coefficient can also be reduced. We design the ribbon waveguide which uses LiNbO3 crystal and discuss the phase-matching condition for DFG of THz wave. Highly efficient THz-wave generation is confirmed by numerical simulations. (C) 2007 Optical Society of America
Motion Planning of Bimanual Robot Using Adaptive Model of Assembly
No full textThis paper presents a motion planning method for a bimanual robot for executing assembly tasks. The method employs ail adaptive modeling which can automatically generate, in assembly model and modify the model during actual assembly. Bimanual robotic assembly is modeled at the task-level using contact states of workpieces and their transitions. The lower-level velocity commands of the workpieces are automatically derived by solving optimization problem formulated with assembly constraints, position of the workpieces, and kinematics of manipulators. Motion requirements of the workpieces are transformed to motion commands of the bimanual robot. The proposed approach is evaluated with experiments on peg-in-hole assembly with ail L-shaped peg
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