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A Dynamic Non-preemptive Priority Queueing Model with Two Types of Customers
No full textIn this paper, we study a single-server non-preemptive priority queueing model with two types of customers. The customers arrive according to two independent Poisson processes, and the service times are exponential with possibly different parameters. While Type 1 customers, who have non-preemptive priority over Type 2 customers, have a finite waiting room, Type 2 customers have no such restriction. A new dynamic rule based on a predetermined threshold is applied in offering services to lower-priority customers (when higher-priority customers are present) whenever the server becomes free. Using matrix-analytic methods, we analyze the model in steady state and bring out some qualitative and interesting aspects of the model under study. We also compare our model to the classical two-customer non-preemptive priority model to show a marked improvement in the quality of service to customers under the proposed threshold model
New Course Development and Assessment Tools in Automotive Lightweighting Technologies
No full textAutomotive industry traditionally has reduced weight primarily by downsizing. Today, the strategy of downsizing vehicle has reached its limits. The OEMs are also facing substantial increases in Corporate Average Fuel Economy (CAFE) regulations in the U.S. and the other global markets. In this context, engineering students need to understand the underlying contributors that significantly play a role in vehicle Lightweighting. One of the main contributors is the appropriate use of a variety of high strength and lightweight materials to meet the mass (weight) targets. Another aspect and a more challenging issue is that a realization of how OEMs are learning to cost effectively join (weld, rivet, form and cast) lightweight (and often multi) materials on a global platform. How to impart these ideas in to a single course? The purpose of this paper is to discuss the need and strategic development of undergraduate and graduate level course materials on this topic and the best assessment techniques to gauge the understanding of the topics by the students. The teaching and learning experiences of the author in delivering this course and related topics to two different levels of student audience, and to general technical audience at invited talks and conferences are also briefly discussed in this paper. Finally, at appropriate time, all course material taught will be consolidated for possible publication as an introductory textbook on this subject matter
Implantable Fluid Delivery System
Get PDFAn implantable system for delivering fluids , such as drugs , to one or more anatomical structures in a patient \u27 s ( i . e . , human or animal ) body . A number of medical conditions require continual and / or periodic administration of fluids ( e . g . , drugs ) to target regions ( e . g . , anatomic organs ) of the body . Accessibility to those target regions might be limited technically for ex . and not limited to : frequent endoscopic , radiologically guided or surgical approaches . The system delivers the fluid needed in a continual or intermittent fashion to the target region . It controls the amount of fluid delivered to the target region and measures the intended physiologic effect of the fluid delivered
Effective method of treatment of industrial effluents under basic pH conditions using acoustic cavitation – A comprehensive comparison with hydrodynamic cavitation processes
No full textThe use of acoustic cavitation in advanced oxidation processes (AOPs) is a promising trend in research for treatment of industrial effluents. The paper presents the results of investigations on the use of acoustic cavitation aided by additional oxidation processes (ozonation/H2O2 oxidation/Peroxone/UV-C) for the treatment of effluents from the production of bitumens. Under these conditions, the total contaminant load, expressed as chemical oxygen demand (COD), could be lowered by 51%. In addition, changes in concentrations of volatile organic compounds identified in the effluents following the treatment are discussed. The investigations revealed that by using acoustic cavitation combined with the Peroxone process, the majority of oxygenated organic compounds were oxidized. The paper also compares AOPs based on acoustic cavitation with hydrodynamic cavitation-aided processes. This study revealed that the use of acoustic cavitation results in a higher effectiveness of degradation of organic compounds using AOPs based on hydrogen peroxide. On the other hand, hydrodynamic cavitation is generally a slightly more effective method for degradation of organic compounds for ozone-based AOPs. Furthermore, furfural and 2-methylcyclohexanone were discovered as secondary pollutants whose concentration increased during the treatment
Comparison of HOG, LBP and Haar-Like Features for On-Road Vehicle Detection
No full textAutonomous vehicles may be the most significant innovation in transportation since automobiles were first invented. Environmental perception plays a pivotal role in the development of self-driving vehicles which need to navigate in a complex environment of static and dynamic objects. It is required to extract dynamic objects like vehicles and pedestrians more precisely and robustly to estimate the current position, motion and predict its future position. In this article, the performance of three commonly used object detection approaches, Histogram of Oriented Gradients (HOG), Haar-like features and Local Binary Pattern (LBP) is investigated and analyzed using a public dataset of camera images. The detection results show that for the same dataset, LBP features perform better than the other two feature types with a higher detection rate. Finally, a unique and robust detection algorithm using a combination of all the three different feature descriptors and AdaBoost cascade classification is proposed
Selective Death of Y79 Retinoblastoma Cells by Magnetic Hyperthermia via Caspase Dependent Apoptotic Pathway
No full textPurpose : To evaluate the selective death of Y79 retinoblastoma cells using dextran-coated iron oxide nanoparticles in a magnetic hyperthermia paradigm and assess the molecular pathways that play a role in cell death.
Methods : Y79 and ARPE-19 cells were exposed to different concentrations of dextran-coated iron oxide magnetic nanoparticles: 250, 500, 750 and 1000 µg/ml. After 2 hours of incubation, cells were exposed to a magnetic field with frequency and intensity values of 250 kHz and 4 kA/m at temperature of 43-44 degreeC for 30 minutes. Hyperthermia induced apoptosis was assessed at 4, 24 and 72 hours after treatment. Transmission electron microscopy was performed to elucidate the cellular uptake and distribution of nanoparticles in Y79 and ARPE-19 cells. Gene expression profiling for apoptosis was performed using RT2 Profiler PCR arrays.
Results : At 4 hours, cell death for Y79 cells was estimated to be 16, 16, 18 and 24% for 250, 500, 750 and 1000 µg/ml, respectively. At 24 hours, cell death in Y79 cells was estimated to be 46, 57, 67, and 73% at respective four concentrations. Y79 retinoblastoma cells underwent apoptosis at 72 hours with cell death estimated at 16, 48, 52 and 57% respectively with increasing nanoparticle concentrations. Magnetic hyperthermia did not have a significant toxic effect on ARPE-19 cells for all four concentrations of nanoparticles. Minimal baseline cytotoxicity of nanoparticles was observed without magnetic field activation. Transmission Electron Microscopy images showed that dextran-coated iron oxide nanoparticles were engulfed into the cytoplasm of both Y79 and ARPE-19 cells and specifically located in endosomes. Gene expression profiling showed that genes in the FAS signaling pathway and TNF alpha signaling were activated in Y79 retinoblastoma cells at 24 hours after magnetic hyperthermia. qRT-PCR results showed an increased gene expression of caspase8, caspase10, caspase14, caspase9 and cytochromeC. 48 hours after magnetic hyperthermia, we observed significantly increased caspase 3/7 activity in Y79 cells, confirming that apoptosis through intrinsic and extrinsic pathways were activated in these cells.
Conclusions : Magnetic hyperthermia using dextran-coated iron oxide nanoparticles were engulfed by both Y79 and ARPE-19 cells. They satisfactorily and selectively killed Y79 cells at 750 and 1000 µg/ml concentrations via activation of two apoptotic pathways
