The geometry which is the topic of this book is that determined by a map of one space N onto another, M, mapping a diffusion process, or operator, on N to one on M. Filtering theory is the science of ...obtaining or estimating information about a system from partial and possibly flawed observations of it. The system itself may be random, and the flaws in the observations can be caused by additional noise. In this volume the randomness and noises will be of Gaussian white noise type so that the system can be modelled by a diffusion process, that is it evolves continuously in time in a Markovian way, the future evolution depending only on the present situation. This is the standard situation of systems governed by Ito type stochastic differential equations. The state space will be the smooth manifold, N, possibly infinite dimensional, and the 'observations' will be obtained by a smooth map onto another manifold, N, say. We emphasise that the geometry is important even when both manifolds are Euclidean spaces. This can also be viewed from a purely partial differential equations viewpoint as one smooth second order elliptic partial differential operator lying above another, both with no zero order term. We consider the geometry of this situation with special emphasis on situations of geometric, stochastic analytic, or filtering interest. The most well studied case is of one Brownian motion being mapped to another with a consequent skew product decomposition (or equivalently the case of Riemannian submersions). This sort of decomposition is generalised and a key to the rest of the book. It is used to study in particular, classical filtering, (semi-)connections determined by stochastic flows, and generalised Weitzenbock formulae.
This volume contains the proceedings of the AMS Special Session on Unimodularity in Randomly Generated Graphs, held from October 8-9, 2016, in Denver, Colorado.Unimodularity, a term initially used in ...locally compact topological groups, is one of the main examples in which the generalization from groups to graphs is successful. The ``randomly generated graphs'', which include percolation graphs, random Erdos-Renyi graphs, and graphings of equivalence relations, are much easier to describe if they result as random objects in the context of unimodularity, with respect to either a vertex-transient ``host''-graph or a probability measure.This volume tries to give an impression of the various fields in which the notion currently finds strong development and application: percolation theory, point processes, ergodic theory, and dynamical systems.
For Markov processes with absorption, we provide general criteria ensuring the existence and the exponential non-uniform convergence in total variation norm to a quasi-stationary distribution. We ...also characterize a subset of its domain of attraction by an integrability condition, prove the existence of a right eigenvector for the semigroup of the process and the existence and exponential ergodicity of the Q-process. These results are applied to one-dimensional and multi-dimensional diffusion processes, to pure jump continuous time processes, to reducible processes with several communication classes, to perturbed dynamical systems and discrete time processes evolving in discrete state spaces.
•Three categories of FBR-Fenton processes for industrial wastewater treatment.•Factors to enhance organics removal and iron crystallization efficiency are reviewed.•Technology upscaling of ...FBR-Fenton-like processes is challenging.•Strategies to tackle technical limitations and enhance process cost-effectiveness.
In recent years, fluidized-bed Fenton (FBR-Fenton) process has gained more attention in treating recalcitrant industrial wastewater. FBR-Fenton combines the effectiveness of homogeneous Fenton and sludge reduction of heterogeneous Fenton. Comparing to other modified Fenton processes, FBR-Fenton has greater economical and scaling up potential. However, large consumption of Fenton reagents and strict pH control are still the bottlenecks hampering the full-scale application of FBR-Fenton. While prior reviews mainly focused on the operation and performance of FBR-Fenton process, the present study critically discussed the challenges and bottlenecks for its full-scale industrial application. This study also comprehensively reviewed the development strategies for tackling these drawbacks, mainly over the recent five years. Homogeneous FBR-Fenton, heterogeneous FBR-Fenton and heterogeneous FBR-photo-Fenton processes were classified for the first time according to their reaction mechanisms and system designs. Important operational and design parameters affecting the cost-effectiveness of all FBR-Fenton technologies were reviewed, including the fundamentals, common practices and even innovative steps for enhancing the process performance. Up-to-date applications of FBR-Fenton technologies in recalcitrant wastewater/compounds treatment were also summarized, and it was found that upscaling of heterogeneous FBR-Fenton and heterogeneous FBR-photo-Fenton processes was still very challenging. Strategies to overcome the key technical limitations and enhance process cost-effectiveness were discussed in the future perspective part. Furthermore, modelling techniques such as computational fluid dynamics model and artificial neural network were suggested to be promising modelling techniques for speeding up the full-scale applications of FBR-Fenton technologies.
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The focus of this book is the evolution of cardiovascular and respiratory control in vertebrates. Life originated in water, which has constantly changing temperatures and O2 levels. Fish gills can ...extract up to 80% of their inspired O2, because they have a countercurrent bloodstream. Oxygen sensors have been found within the gill arches of ray-finned fish such as carp and trout, and these O2 sensors screen the inspired water and the capillary blood. Very likely, land vertebrates and the lungfish arose as a sister group, and both possess real lungs. Lungfish include 6 species, inhabiting shallow lakes or rivers, whereas the second ramification includes all the land vertebrates. A possible ancestor to the lungfish and land vertebrates has been discovered in China, and this fossil (Styloichthys) bridges a gap. Living 417 million years ago, it could represent one of the last ramifications before the common ancestor to the lungfish and land vertebrates. In addition, rather constant atmospheric O2 levels permit a joint acid-base regulation by the lung and the kidney. Likewise, lungfish and land vertebrates share a central control of pulmonary ventilation, while the peripheral receptor contribution to acid-base regulation is minor.
Landfill leachate is a type of complex organic wastewater, which can easily cause serious negative impacts on the human health and ecological environment if disposed improperly. Electrochemical ...technology provides an efficient approach to effectively reduce the pollutants in landfill leachate. In this review, the electrochemical standalone processes (electrochemical oxidation, electrochemical reduction, electro-coagulation, electro-Fenton process, three-dimensional electrode process, and ion exchange membrane electrochemical process) and the electrochemical integrated processes (electrochemical-advanced oxidation process (AOP) and biological electrochemical process) for landfill leachate treatment are summarized, which include the performance, mechanism, application, existing problems, and improvement schemes such as cost-effectiveness. The main objective of this review is to help researchers understand the characteristics of electrochemical treatment of landfill leachate and to provide a useful reference for the design of the process and reactor for the harmless treatment of landfill leachate.
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•Electrochemical processes for landfill leachate treatment•Advantages and shortcomings of electrochemical processes•Improvement schemes of electrochemical processes•Future research needs on landfill leachate electrochemical treatment
One of the major environmental problems caused by the agro-food industry is the treatment of olive mill wastewater (OMW). OMW is a byproduct of olive oil production and is characterized by high ...concentrations of various organic compounds, including organic acids, pectin, and polyphenols, as well as inorganic compounds like sulfate, chlorides, and phosphoric salts of potassium and sodium, and trace amounts of other elements. These compounds make OMW complex and toxic to plants, inhibiting bacterial activity. Therefore, these compounds must be removed from wastewater before it is discharged into the environment. Many conventional treatment processes for OMW have been used, relying on physical, biological, and chemical methods. However, they have limitations and low efficiency in removing pollutants, as they only transfer pollutants from one stage to another. The ultimate goal of any treatment process is to achieve complete mineralization of pollutants, which can be achieved through the integration of appropriate processes. Over the years, many researchers have evaluated various combined treatment methods to enhance treatment efficiency and comply with environmental regulations regarding wastewater discharge. This review focuses on combined treatment methods for treated OMW. We analyzed preliminary results in the literature and discussed many parameters used to improve the process. Additionally, this review summarizes the combined processes according to their respective types, along with their benefits, drawbacks, and future prospects. It also summarizes the environmental impacts of treating OMW. In general, the results extracted from the literature review show that combined treatment processes have proven effective in treating OMW and should remain a focal point for the development of enhanced processes that can remove more pollutants in a single process.
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•The review summarizes the performance of more than 54 combined processes in removing various pollutants from olive mill wastewater (OMW).•Combined processes are more convincing and efficient than single processes for OMW treatment.•The study found that combined chemical-chemical and chemical-biological treatment processes are OMW's most common and widely used combination treatments.•Fenton and coagulation/flocculation (C/F) methods are the best treatments to be integrated as combined methods.
Statistical Analysis of a Telephone Call Center Brown, Lawrence; Gans, Noah; Mandelbaum, Avishai ...
Journal of the American Statistical Association,
03/2005, Letnik:
100, Številka:
469
Journal Article
Recenzirano
A call center is a service network in which agents provide telephone-based services. Customers who seek these services are delayed in tele-queues. This article summarizes an analysis of a unique ...record of call center operations. The data comprise a complete operational history of a small banking call center, call by call, over a full year. Taking the perspective of queueing theory, we decompose the service process into three fundamental components: arrivals, customer patience, and service durations. Each component involves different basic mathematical structures and requires a different style of statistical analysis. Some of the key empirical results are sketched, along with descriptions of the varied techniques required. Several statistical techniques are developed for analysis of the basic components. One of these techniques is a test that a point process is a Poisson process. Another involves estimation of the mean function in a nonparametric regression with lognormal errors. A new graphical technique is introduced for nonparametric hazard rate estimation with censored data. Models are developed and implemented for forecasting of Poisson arrival rates. Finally, the article surveys how the characteristics deduced from the statistical analyses form the building blocks for theoretically interesting and practically useful mathematical models for call center operations.
Manufacturing Process Selection Handbook provides engineers and designers with process knowledge and the essential technological and cost data to guide the selection of manufacturing processes early ...in the product development cycle. Building on content from the authors' earlier introductory Process Selection guide, this expanded handbook begins with the challenges and benefits of identifying manufacturing processes in the design phase and appropriate strategies for process selection. The bulk of the book is then dedicated to concise coverage of different manufacturing processes, providing a quick reference guide for easy comparison and informed decision making. For each process examined, the book considers key factors driving selection decisions, including: * Basic process descriptions with simple diagrams to illustrate * Notes on material suitability * Notes on available process variations * Economic considerations such as costs and production rates * Typical applications and product examples * Notes on design aspects and quality issues Providing a quick and effective reference for the informed selection of manufacturing processes with suitable characteristics and capabilities, Manufacturing Process Selection Handbook is intended to quickly develop or refresh your experience of selecting optimal processes and costing design alternatives in the context of concurrent engineering. It is an ideal reference for those working in mechanical design across a variety of industries and a valuable learning resource for advanced students undertaking design modules and projects as part of broader engineering programs. * Provides manufacturing process information maps (PRIMAs) provide detailed information on the characteristics and capabilities of 65 processes in a standard format * Includes process capability charts detailing the processing tolerance ranges for key material types * Offers detailed methods for estimating costs, both at the component and assembly level
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