A General Stochastic Process for Day-to-Day Dynamic Traffic Assignment: Formulation, Asymptotic Behaviour, and Stability Analysis

This paper presents a general modelling approach to day-to-day dynamic assignment to a congested network through discrete-time stochastic and deterministic process models including an explicit modelling of users’ habit as a part of route choice behaviour, through an exponential smoothing filter, and of their memory of network conditions on past days, through a moving average or an exponentially smoothing filter. An asymptotic analysis of the mean process is carried out to provide a better insight. Results of such analyses are also used for deriving conditions, about values of the system parameters, assuring that the mean process is dissipative and/or converges to some kind of attractor. Numerical small examples are also provided in order to illustrate the theoretical results obtained

Ectopic expression of the HLXB9 gene is associated with an altered nuclear position in t(7;12) leukaemias

This article is available open access through the publisher’s website at the link below. Copyright @ 2009 Macmillan Publishers Ltd.No abstract available (Letter to the editor).The Leukaemia Research Fun

Feasibility of chest ultrasound up to 42 m underwater

After recent advancements, ultrasound has extended its applications from bedside clinical practice to wilderness medicine. Performing ultrasound scans in extreme environments can allow direct visualization of unique pathophysiological adaptations but can be technically challenging. This paper summarizes how a portable ultrasound apparatus was marinized to let scientific divers and sonographers perform ultrasound scans of the lungs underwater up to − 42 m. A metallic case protected the ultrasound apparatus inside; a frontal transparent panel with a glove allowed visualization and operation of the ultrasound by the diving sonographer. The inner pressure was equalized with environmental pressure through a compressed air tank connected with circuits similar to those used in SCUBA diving. Finally, the ultrasound probe exited the metallic case through a sealed aperture. No technical issues were reported after the first testing step and the real experiments

Upland rice under no-tillage preceded by crops for soil cover and nitrogen fertilization.

The grain yield of upland rice under no-tillage has been unsatisfactory and one reason could be the nitrate/ammonium balance in the soil. Cover crops and nitrogen fertilization can be used to change the nitrate/ammonium relation in the soil and improve conditions for the development of upland rice in the no-tillage (NT) system. The aim was to study the effect of cover crops and nitrogen sources on grain yield of upland rice under no tillage. The study was carried out on the Fazenda Experimental Lageado, in Botucatu, State of São Paulo, Brazil, in an Oxisol area under no-tillage for six years. The experiment was arranged in a randomized block split-plot design with four replications. The plots consisted of six cover crop species (Brachiaria brizantha, B. decumbens, B. humidicola, B. ruziziensis, Pennisetum americanum, and Crotalaria spectabilis) and the split-plots of seven forms of N fertilizer management. Millet is the best cover crop to precede upland rice under NT. The best form of N application, as nitrate, is in split rates or total rate at topdressing or an ammonium source with or without a nitrification inhibitor, in split doses. When the cover crops C. spectabilis, B. brizantha, B. decumbens, B. humidicola, and B. ruziziensis preceded rice, they induced the highest grain yield when rice was fertilized with N as ammonium sulfate source + nitrification inhibitor in split rates or total dose at topdressing

Teor de nitrogênio inorgânico no solo em função de plantas de cobertura, fontes de nitrogênio e inibidor de nitrificação.

A utilização de plantas de cobertura pode alterar a relação NO3 -:NH4 + no solo, proporcionando maiores quantidades de NH4 + e podendo viabilizar o desenvolvimento de culturas que absorvem mais e preferem esta forma de nitrogênio (N), como o arroz. Objetivou-se avaliar a influência da interação de plantas de cobertura e fontes de N, com e sem inibidor de nitrificação (dicianodiamida), em sistema plantio direto (SPD). O experimento foi realizado em 2009/2010, em Botucatu (SP), em Latossolo Vermelho distroférrico cultivado por seis anos no SPD. O delineamento experimental foi em blocos casualizados, em esquema de parcela subdividida, com quatro repetições. As parcelas foram constituídas por seis espécies de plantas de cobertura do solo (Urochloa brizantha, U. decumbens, U. humidicola, U. ruziziensis, Pennisetum americanum e Crotalaria spectabilis) e as subparcelas por sete formas de fertilização nitrogenada, aos 0 e 30 dias após a emergência (DAE) do arroz [1 - controle, sem aplicação de nitrogênio; 2 - nitrato de cálcio (40 + 40 kg ha-1); 3 - nitrato de cálcio (0 + 80 kg ha-1); 4 - sulfato de amônio (40 + 40 kg ha-1); 5 - sulfato de amônio (0 + 80 kg ha-1); 6 - sulfato de amônio + dicianodiamida (40 + 40 kg ha-1); e 7 - sulfato de amônio + dicianodiamida (0 + 80 kg ha-1)]. O uso do inibidor de nitrificação e o cultivo de C. spectabilis proporcionaram maiores teores de amônio no solo. A aplicação da fonte amoniacal sem inibidor em dose total aos 30 DAE e com inibidor tanto parcelada quanto em dose total proporcionaram os maiores teores de nitrato no solo

Advanced Vehicles: Challenges for Transportation Systems Engineering

Automatic vehicles represent one of the most active research fields within engineering. Among transportation systems engineering research topics, we highlight the need to update and/or develop new mathematical models, computer science methods and electronic technologies that contribute to the development of more effective, accurate and robust tools. In order to develop more effective models, it is advisable to consider the opportunity to interact with other specialists from sectors different of the transportation systems engineering to provide solutions to problems that may arise during the modeling and further new points of view. The main goal of this paper is discussing the most likely positive and negative effects of mixed flow expected in the near future, analyzing the main classifying criteria such as ownership, on-board technologies (sensor), and reviewing the most effective tools already available for macroscopic analysis of multi vehicle type transportation systems

scheduled synchronisation based on a mesoscopic flow model with speed dispersion

Abstract This paper proposes a method for netwok signal setting design, based on enhacements of an existing coordination method aiming: 1) to extend the existing approach in order to address the Traffic Control through Scheduled Synchronisation (i.e 'one step' optimisation of stage matrix, green timings, and node offsets ); 2) to extend the considered Mesoscopic Traffic Flow model (TRAFFMED) to the vehicle platoon speed dispersion; 3) to build up a solution method suitable for both off-line and on-line applications. The proposed optimisation method is an application of the Simulated Annealing meta-heuristic. Some numerical applications are proposed, specifically analysing 'two step' optimisation (synchronisation), and'one step' optimisation (scheduled synchronisation), for off-line (pre-timed strategy) and on-line applications (on-line computation strategy). A grid network was considered as case study and the effectiveness of the proposed strategies were evaluated by comparing the obtained results with those computed through commercial (benchmark) and in-house codes

solving stochastic assignment to transportation networks with tvs and avs

Abstract This paper focuses on solving stochastic assignment with several types of vehicles, for instance advanced and traditional vehicles, competing for the same arcs and jointly participating to congestion. In urban transportation networks paths likely overlap, thus two path choice models, derived from Random Utility Theory, are analyzed: Probit and Gammit, properly modeling path overlap through covariance between path perceived utilities. Since for these two models no closed form is available for choice probabilities, two specifications of Montecarlo algorithms for assignment to uncongested networks are presented: the efficiency of the commonly used Mersenne Twister Pseudo-Random Number Generator is compared with a PRNG based on Sobol (quasi-random) numbers. Then, several MSA-based algorithms for equilibrium assignment ot congested networks are analyzed: some step size strategies are proposed and compared with existing ones aiming at improving practical rate of convergence. Sufficient convergence conditions are presented for equilibrium assignment with arc cost flow functions with symmetric or asymmetric Jacobian matrix. Results of applications are also discussed to support theoretical results