Matrix product approach for the asymmetric random average process

We consider the asymmetric random average process which is a one-dimensional stochastic lattice model with nearest neighbour interaction but continuous and unbounded state variables. First, the explicit functional representations, so-called beta densities, of all local interactions leading to steady states of product measure form are rigorously derived. This also completes an outstanding proof given in a previous publication. Then, we present an alternative solution for the processes with factorized stationary states by using a matrix product ansatz. Due to continuous state variables we obtain a matrix algebra in form of a functional equation which can be solved exactly.Comment: 17 pages, 1 figur

Construction of the factorized steady state distribution in models of mass transport

For a class of one-dimensional mass transport models we present a simple and direct test on the chipping functions, which define the probabilities for mass to be transferred to neighbouring sites, to determine whether the stationary distribution is factorized. In cases where the answer is affirmative, we provide an explicit method for constructing the single-site weight function. As an illustration of the power of this approach, previously known results on the Zero-range process and Asymmetric random average process are recovered in a few lines. We also construct new models, namely a generalized Zero-range process and a binomial chipping model, which have factorized steady states.Comment: 6 pages, no figure

Breakdown and recovery in traffic flow models

Most car-following models show a transition from laminar to ``congested'' flow and vice versa. Deterministic models often have a density range where a disturbance needs a sufficiently large critical amplitude to move the flow from the laminar into the congested phase. In stochastic models, it may be assumed that the size of this amplitude gets translated into a waiting time, i.e.\ until fluctuations sufficiently add up to trigger the transition. A recently introduced model of traffic flow however does not show this behavior: in the density regime where the jam solution co-exists with the high-flow state, the intrinsic stochasticity of the model is not sufficient to cause a transition into the jammed regime, at least not within relevant time scales. In addition, models can be differentiated by the stability of the outflow interface. We demonstrate that this additional criterion is not related to the stability of the flow. The combination of these criteria makes it possible to characterize commonalities and differences between many existing models for traffic in a new way

Corporate Governance, Opaque Bank Activities, and Risk/Return Efficiency: Pre- and Post-Crisis Evidence from Turkey

Does better corporate governance unambiguously improve the risk/return efficiency of banks? Or does either a re-orientation of banks' revenue mix towards more opaque products, an economic downturn, or tighter supervision create off-setting or reinforcing effects? The authors relate bank efficiency to shortfalls from a stochastic risk/return frontier. They analyze how internal governance mechanisms (CEO duality, board experience, political connections, and education profile) and external governance mechanisms (discipline exerted by shareholders, depositors, or skilled employees) determine efficiency in a sample of Turkish banks. The 2000 financial crisis was a wakeup call for bank efficiency and corporate governance. As a result, better corporate governance mechanisms have been able to improve risk/return efficiency when the economic, regulatory, and supervisory environments are more stable and bank products are more complex.corporate governance;bank risk;noninterest income;crisis;frontier

Applications of RESRAD family of computer codes to sites contaminated with radioactive residues.

The RESIL4D family of computer codes was developed to provide a scientifically defensible answer to the question ''How clean is clean?'' and to provide useful tools for evaluating human health risk at sites contaminated with radioactive residues. The RESRAD codes include (1) RESRAD for soil contaminated with radionuclides; (2) RESRAD-BUILD for buildings contaminated with radionuclides; (3) RESRAD-CHEM for soil contaminated with hazardous chemicals; (4) RESRAD-BASELINE for baseline risk assessment with measured media concentrations of both radionuclides and chemicals; (5) RESRAD-ECORISK for ecological risk assessment; (6) RESRAD-RECYCLE for recycle and reuse of radiologically contaminated metals and equipment; and (7) RESRAD-OFFSITE for off-site receptor radiological dose assessment. Four of these seven codes (RESRAD, RESRAD-BUILD, RESRAD-RECYCLE, and RESRAD-OFFSITE) also have uncertainty analysis capabilities that allow the user to input distributions of parameters. RESRAD has been widely used in the United States and abroad and approved by many federal and state agencies. Experience has shown that the RESRAD codes are useful tools for evaluating sites contaminated with radioactive residues. The use of RESRAD codes has resulted in significant savings in cleanup cost. Analysis of 19 site-specific uranium guidelines is discussed in the paper

Asthma

Asthma is the most common respiratory disorder in Canada. Despite significant improvement in the diagnosis and management of this disorder, the majority of Canadians with asthma remain poorly controlled. In most patients, however, control can be achieved through the use of avoidance measures and appropriate pharmacological interventions. Inhaled corticosteroids (ICSs) represent the standard of care for the majority of patients. Combination ICS/long-acting beta2-agonists (LABA) inhalers are preferred for most adults who fail to achieve control with ICS therapy. Allergen-specific immunotherapy represents a potentially disease-modifying therapy for many patients with asthma, but should only be prescribed by physicians with appropriate training in allergy. Regular monitoring of asthma control, adherence to therapy and inhaler technique are also essential components of asthma management. This article provides a review of current literature and guidelines for the appropriate diagnosis and management of asthma

Nonequilibrium Statistical Mechanics of the Zero-Range Process and Related Models

We review recent progress on the zero-range process, a model of interacting particles which hop between the sites of a lattice with rates that depend on the occupancy of the departure site. We discuss several applications which have stimulated interest in the model such as shaken granular gases and network dynamics, also we discuss how the model may be used as a coarse-grained description of driven phase-separating systems. A useful property of the zero-range process is that the steady state has a factorised form. We show how this form enables one to analyse in detail condensation transitions, wherein a finite fraction of particles accumulate at a single site. We review condensation transitions in homogeneous and heterogeneous systems and also summarise recent progress in understanding the dynamics of condensation. We then turn to several generalisations which also, under certain specified conditions, share the property of a factorised steady state. These include several species of particles; hop rates which depend on both the departure and the destination sites; continuous masses; parallel discrete-time updating; non-conservation of particles and sites.Comment: 54 pages, 9 figures, review articl

Allergen-specific immunotherapy

Allergen-specific immunotherapy is a potentially disease-modifying therapy that is effective for the treatment of allergic rhinitis/conjunctivitis, allergic asthma and stinging insect hypersensitivity. However, despite its proven efficacy in these conditions, it is frequently underutilized in Canada. The decision to proceed with allergen-specific immunotherapy should be made on a case-by-case basis, taking into account individual patient factors such as the degree to which symptoms can be reduced by avoidance measures and pharmacological therapy, the amount and type of medication required to control symptoms, the adverse effects of pharmacological treatment, and patient preferences. Since this form of therapy carries the risk of anaphylactic reactions, it should only be prescribed by physicians who are adequately trained in the treatment of allergy. Furthermore, injections must be given under medical supervision in clinics that are equipped to manage anaphylaxis. In this article, the authors review the indications and contraindications, patient selection criteria, and the administration, safety and efficacy of allergen-specific immunotherapy

User's manual for RESRAD version 6.

This manual provides information on the design and application of the RESidual RADioactivity (RESRAD) code. It describes the basic models and parameters used in the RESRAD code to calculate doses and risks from residual radioactive materials and the procedures for applying these models to calculate operational guidelines for soil contamination. RESRAD has undergone many improvements to make it more realistic in terms of the models used in the code and the parameters used as defaults. Version 6 contains a total of 145 radionuclides (92 principal and 53 associated radionuclides), and the cutoff half-life for associated radionuclides has been reduced to 1 month. Other major improvements to the RESRAD code include its ability to run uncertainty analyses, additional options for graphical and text output, a better dose conversion factor editor, updated databases, a better groundwater transport model for long decay chains, an external ground radiation pathway model, an inhalation area factor model, time-integration of dose and risk, and a better graphical user interface. In addition, RESRAD has been benchmarked against other codes in the environmental assessment and site cleanup arena, and RESRAD models have been verified and validated