Search results for "Complex."
showing 10 items of 5824 documents
An assessment of the state of grain mixture with the use of the method of statistical reduction
1995
Abstract A new way of assessment of the state of a granular mixture is presented in this paper. It is based on the method of statistical reduction and it enables a more precise assessment to be made of the state of a grain mixture as compared with other methods, especially when the mixture represents a large population. The new method is illustrated by a computational example.
odeling of Human Arm Energy Expenditure for Predicting Energy Optimal Trajectories
2011
Human arm motion can inspire the trajectory planning of anthropomorphic robotic arms to achieve energy-efficient movements. An approach for predicting metabolic cost in the planar human arm motion by means of the biomechanical simulation is proposed in this work. Two biomechanical models, including an analytical model and a musculoskeletal model, are developed to implement the proposed approach. The analytical model is developed by modifying a human muscle expenditure model, in which the muscles are grouped as torque providers for computation efficiency. In the musculoskeletal model, the predication of metabolic cost is conducted on the basis of individual muscles. With the proposed approac…
Measurement-based load modelling for power supply system design
2008
Load modelling is essential to simulate system features as closely as possible to the effective behaviour. In spite of model complexity, the need for accuracy often leads to a component-based approach, i.e. the analysis of load internal subsystems. It is a common belief that measurement-based load models lead to low accuracy. This paper presents a new, high-accuracy measurement-based load modelling approach to define a power consumption profile load model for power systems design. The load modeling technique is described by an application. Simulation and experimental results are compared. The efficiency and portability of the proposed modelling approach is discussed. ©2008 IEEE.
On the material flow in fsw of T-joints: influence of geometrical and tecnological parameters
2008
Friction stir welding (FSW) now definitively reached a large interest in the scientific community and what is more in the industrial environment, due to the advantages of such solid state welding process with respect to the classic ones. The latter aspects are relevant also with reference to joints characterized by a complex geometry. What is more, advanced FEM tools permit to develop effective engineering of the processes; quantitative results can be acquired from numerical simulations once basic information, as the process mechanics and the material flow, are certain. Material flow plays a fundamental role in FSW since it determines the effectiveness of the joints or, in turn, the insurge…
A comprehensive tool for efficient design and operation of polygeneration-based energy μgrids serving a cluster of buildings. Part I: Description of …
2013
Polygeneration systems with thermal energy storage represent promising solutions to achieve energy saving and emissions reduction in the civil sector. The definition of customer-oriented design and operation strategies represents a most challenging task, in order to maximize the profitability and make the investment attractive. A large potential is often recognized for the installation of centralized plants serving a cluster of buildings located over a small area; in such cases the design problem becomes extremely complex and the analyst needs reliable instruments to identify the optimal solution. This paper in two parts presents a scientific tool for the optimization of design and operatio…
Design optimization on the drive train of a light-weight robotic arm
2011
A drive train optimization method for design of light-weight robots is proposed. Optimal selections of motors and gearboxes from a limited catalog of commercially available components are done simultaneously for all joints of a robotic arm. Characteristics of the motor and gearbox, including gear ratio, gear inertia, motor inertia, and gear efficiency, are considered in the drive train modeling. A co-simulation method is developed for dynamic simulation of the arm. A design example is included to demonstrate the proposed design optimization method.
Phasor total unbalance power: Formulation and some properties
2007
Unbalance power has been used to quantify unbalance phenomenon effects in the electric power systems for a long time. Expressions of this power developed by some different theories only give the value of its module. Therefore, total unbalance power values in electric power systems cannot be obtained by the unbalance power values of each of their loads. For that, it is necessary to express the unbalance power as a complex number. In this paper the unbalance power is expressed in phasor notation and some of their properties are described, applied to electric systems with balanced voltages. Results are verified by simulation and also practical comparative experiences are realized in actual ins…
An extension of the fractional model for construction of asphalt binder master curve
2015
Knowledge and prediction of viscoelastic behaviour of asphalt binder is of great interest in order to design asphalt mixtures for civil construction of road and airports with good performances. The capability of a fractional model – requiring a very limited number of parameters – to describe and predict the linear viscoelastic behaviour of asphalt binder subjected to sinusoidal oscillations is investigated. Experimental data of complex modulus, |G*|, and phase angle, δ, are used to validate the proposed constitutive model. Based on the proposed extension of a fractional model, complex modulus isotherms for a range of frequencies can be created simply starting from isochronals at frequency v…
A multi-agent system reinforcement learning based optimal power flow for islanded microgrids
2016
In this paper, a distributed intelligence algorithm is used to manage the optimal power flow problem in islanded microgrids. The methodology provides a suboptimal solution although the error is limited to a few percent as compared to a centralized approach. The solution algorithm is multi-agent based. According to the method, couples of agents communicate with each other only if the buses where they are located are electrically connected. The overall prizing system required for learning uses a feedback from an approximated model of the network. Based on the latter, a distributed reiforcement learning algorithm is implemented to minimize the joule losses while meeting operational constraints…
Antibacterial studies, DNA oxidative cleavage, and crystal structures of Cu(II) and Co(II) complexes with two quinolone family members, ciprofloxacin…
2005
Nine coordination compounds of Cu(II) and Co(II) with Ciprofloxacin (HCp) and Enoxacin (HEx) as ligands have been prepared and characterized. Single crystal structural determinations of [Cu(HCp)2(ClO4)2].6H2O (1) and [Co(HEx)2(Ex)]Cl.2CH(3)OH.12H2O (4) are reported. The crystal of 1 is composed of [Cu(HCp)2(ClO4)2] units with the two perchlorate anions semicoordinated, and uncoordinated water molecules. The copper ion, at a crystallographic inversion centre, is in a tetragonally distorted octahedral environment. The structure of 4 consists of cationic monomeric [Co(HEx)2(Ex)]+ units, chloride anions, and uncoordinated methanol and water molecules. The complex is six-coordinate, with a sligh…