There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

: This thesis applies neural network feature selection techniques to multivariate time series data to improve prediction of a target time series. Two approaches to feature selection are used. First, a subset enumeration method is used to determine which financial indicators are most useful for aiding in prediction of the S&P 500 futures daily price. The candidate indicators evaluated include RSI, Stochastics and several moving averages. Results indicate that the Stochastics and RSI indicators result in better prediction results than the moving averages. The second approach to feature selection is calculation of individual saliency metrics. A new decision boundary-based individual saliency metric, and a classifier independent saliency metric are developed and tested. Ruck's saliency metric, the decision boundary based saliency metric, and the classifier independent saliency metric are compared for a data set consisting of the RSI and Stochastics indicators as well as delayed closing price values. The decision based metric and the Ruck metric results are similar, but the classifier independent metric agrees with neither of the other metrics. The nine most salient features, determined by the decision boundary based metric, are used to train a neural network and the results are presented and compared to other published results. (AN)

/pdf/nonlinear-time-series-analysis-1j3a35n4y3.pdf

Nonlinear Time Series Analysis.

Commercialization of Lithium Battery Technologies for Electric Vehicles

A surprise announcement by then prime minister Tony Blair in 1998 led to the creation of a new senior clinical role - the nurse consultant.

Work in progress: The evolving nurse consultant role has all-round benefits and should be embraced, finds Frances Pickersgill

A general methodology for dynamic modeling and analysis of multibody systems with multiple clearance joints is presented and discussed in this paper. The joint components that constitute a real joint are modeled as colliding bodies, being their behavior influenced by geometric and physical properties of the contacting surfaces. A continuous contact force model, based on the elastic Hertz theory together with a dissipative term, is used to evaluate the intrajoint contact forces. Furthermore, the incorporation of the friction phenomenon, based on the classical Coulomb’s friction law, is also discussed. The suitable contact-impact force models are embedded into the dynamics of multibody systems methodologies. An elementary mechanical system is used to demonstrate the accuracy and efficiency of the presented approach, and to discuss the main assumptions and procedures adopted. Different test scenarios are considered with the purpose of performing a parametric study for quantifying the influence of the clearance size, input crank speed, and number of clearance joints on the dynamic response of multibody systems with multiple clearance joints. Additionally, the total computation time consumed in each simulation is evaluated in order to test the computational accuracy and efficiency of the presented approach. From the main results obtained in this study, it can be drawn that clearance size and the operating conditions play a crucial role in predicting accurately the dynamic responses of multibody systems.

https://repositorium.sdum.uminho.pt/bitstream/1822/23520/1/6.7.22%202010.pdf

A parametric study on the dynamic response of planar multibody systems with multiple clearance joints

A review on belt and chain continuously variable transmissions (CVT): Dynamics and control

This paper presents an overview of different commer- cial photovoltaic (PV) module options to power on-board electric vehicles (EVs). We propose the evaluation factors, constraints, and the decision-making criteria necessary to assess the suitability of this PV module for this application. The incorporation of quality function deployment (QFD) and the analytical hierarchy process (AHP) is the decision-making methodology used in this study. Our approach is innovative and robust in that the evaluation depends upon data collected from PV manufactures datasheets. Unlike tra- ditional research, a hybrid AHP and QFD innovative decision- making methodology has been created, and current commercial PV market data for all pairwise comparisons are used to show that methodology. Using both cooled and uncooled PV modules, best, intermediate, and worst-case scenarios were used to estimate the driving ranges of lightweight EVs powered exclusively by bulk sil- icon PV modules. Results showed that the available daily driving ranges were between 25 and 60 km and that the CO2 emissions were reduced between 3 and 6.5 kg, compared with internal combustion vehicles of a similar type. We found that mono-Si PV modules were most suited to power low-speed, lightweight, and aerodynamically efficient EVs.

/pdf/evaluation-of-on-board-photovoltaic-modules-options-for-5ch4gh0hmr.pdf

Evaluation of On-Board Photovoltaic Modules Options for Electric Vehicles

Transient dynamics of metal V-belt CVT : Effects of band pack slip and friction characteristic

This article deals with the optimal design of ground vehicles and their subsystems, with particular reference to ‘active’ safety and comfort. A review of state-of-the-art optimization methods for solving vehicle system design problems, including the integration of electronic controls, is given, thus further encouraging the use of such methods as standard tools for automotive engineers. Particular attention is devoted to the class of methods pertaining to complex system design optimization, as well as approaches for the optimal design of complex systems under uncertainty. Some examples of design optimizations are given in the fields of vehicle system dynamics, powertrain/internal combustion engine design, active safety and ride comfort, vehicle system design and lightweight structures, advanced automotive electronics, and smart vehicles.

Optimization and integration of ground vehicle systems

Since ballistic and blast survivability and off-road handling and stability of military vehicles, such as the high-mobility multi-purpose wheeled vehicle (HMMWV), are two critical vehicle performance aspects, they both (including the delicate balance between them) have to be considered when a new vehicle is being designed or an existing vehicle retrofitted (e.g. up- armoured). Finite-element-based transient non-linear dynamics and multi-body longitudinal dynamics computational analyses were employed in the present work to address the following two specific aspects respectively of the performance of an HMMWV: firstly, the ability of the vehicle to survive detonation of a landmine shallow buried into sand underneath the right wheel of the vehicle and, secondly, the ability of the vehicle to withstand a simple straight-line brake manoeuvre during off-road travel without compromising its stability and safety of its occupants. Within the first analysis, the kinematic and structural responses (including large- scale rotation and deformation, buckling, plastic yielding, failure initiation, fracture, and fragmentation) of the HMMWV to the detonation of a landmine were analysed computationally using the general-purpose transient non-linear dynamics analysis software ABAQUS/Explicit. The second analysis was carried out using Simpack, a general purpose multi-body dynamics program, and the main purpose of this analysis was to address the vehicle stability during the off-road travel. The same sand model was used in both types of analysis. Finally, the computational results obtained are compared with general field-test observations and data in order to judge the physical soundness and fidelity of the present approach.

Imtiaz Haque

Papers

A review on belt and chain continuously variable transmissions (CVT): Dynamics and control

Evaluation of On-Board Photovoltaic Modules Options for Electric Vehicles

Transient dynamics of metal V-belt CVT : Effects of band pack slip and friction characteristic

Optimization and integration of ground vehicle systems

Computational investigation of blast survivability and off-road performance of an up-armoured high-mobility multi-purpose wheeled vehicle