Electroweak Theory and Noncommutative Geometry

The noncommutative generalisation of the standard electroweak model due to Balakrishna, Gursey and Wali is formulated in terms of the derivations Der_2(M_3) of a three dimensional representation of the su(2) Lie algebra of weak isospin. A light Higgs boson of mass about 130 GeV, together with four very heavy scalar bosons are predicted.Comment: 11 pages, LATEX, no figures. Talk given at the 2nd Gursey Memorial Conference, June 2000, Istanbu

Automated and model-free bridge damage indicators with simultaneous multi-parameter modal anomaly detection

This paper pursues a simultaneous modal parameter anomaly detection paradigm to structural damage identification inferred from vibration-based structural health monitoring (SHM) sensors, e.g., accelerometers. System Realization Using Information Matrix (SRIM) method is performed in short duration sweeping time windows for identification of state matrices, and then, modal parameters with enhanced automation. Stable modal poles collected from stability diagrams are clustered and fed into the Gaussian distribution-based anomaly detection platform. Different anomaly thresholds are examined both on frequency and damping ratio terms taking two testbed bridge structures as application means, and simplistic Boolean Operators are performed to merge univariate anomalies. The first bridge is a reinforced concrete bridge subjected to incremental damage through a series of seismic shake table experiments conducted at the University of Nevada, Reno. The second bridge is a steel arch structure at Columbia University Morningside Campus, which reflects no damage throughout the measurements, unlike the first one. Two large-scale implementations indicate the realistic performance of automated modal analysis and anomaly recognition with minimal human intervention in terms of parameter extraction and learning supervision. Anomaly detection performance, presented in this paper, shows variation according to the designated thresholds, and hence, the information retrieval metrics being considered. The methodology is well-fitted to SHM problems which require sole data-driven, scalable, and fully autonomous perspectives

Postoperative spinal epidural hematoma resulting in cauda equina syndrome: A case report and review of the literature

Spinal epidural hematoma is a well known complication of spinal surgery. Clinically insignificant small epidural hematomas develop in most spinal surgeries following laminectomy. However, the incidence of clinically significant postoperative spinal epidural hematomas that result in neurological deficits is extremely rare. In this report, we present a 33-year-old female patient whose spinal surgery resulted in postoperative spinal epidural hematoma. She was diagnosed with lumbar disc disease and underwent hemipartial lumbar laminectomy and discectomy. After twelve hours postoperation, her neurologic status deteriorated and cauda equina syndrome with acute spinal epidural hematoma was identified. She was immediately treated with surgical decompression and evacuation of the hematoma. The incidence of epidural hematoma after spinal surgery is rare, but very serious complication. Spinal epidural hematomas can cause significant spinal cord and cauda equina compression, requiring surgical intervention. Once diagnosed, the patient should immediately undergo emergency surgical exploration and evacuation of the hematoma. © 2009 Kaner et al; licensee Cases Network Ltd