Search results for "FLE"
showing 10 items of 3517 documents
Analysis of Offshore Knuckle Boom Crane - Part One: Modeling and Parameter Identification
2013
This paper presents an extensive model of a knuckle boom crane used for pipe handling on offshore drilling rigs. The mechanical system is modeled as a multi-body system and includes the structural flexibility and damping. The motion control system model includes the main components of the crane's electro-hydraulic actuation system. For this a novel black-box model for counterbalance valves is presented, which uses two different pressure ratios to compute the flow through the valve. Experimental data and parameter identification, based on both numerical optimization and manual tuning, are used to verify the crane model. The demonstrated modeling and parameter identification techniques target…
Modeling of out-of-plane behavior of masonry walls
2009
The flexural behavior of rectangular masonry sections is investigated by considering nonlinear stress-strain in compression and limited-tension material. A preliminary analysis shows that, with variation in the parameters specializing with the adopted conventional constitutive law, the experimentally observed behavior of different kinds of masonry materials can be approximated. Subsequently, moment-curvature dimensionless curves are derived numerically by satisfying the equilibrium equations of the section. In the case of negligible tensile strength these curves exhibit a typical shape that can be approximated by analytical expressions; consequently, suitable functions are proposed that are…
Machining Economics in FMS by a Fuzzy Approach
1995
Abstract In a conventional manufacturing system, cutting parameters have to be fixed in order to pursue the economical and productive target related to each cutting operation. In a Flexible Manufacturing System (FMS), as a consequence of the unbalanced workload due to the mutual interaction among the shared resources, the optimization of each operation does not allow the optimum of the global production system to be reached. A fuzzy programming model is developed in this paper in order to select cutting speeds of the operations in the production plan as a satisfying compromise solution between single operation and the integrated system targets.
Influence of the Hourly Variation of Temperature on the Estimation of Fatigue Damage and Rutting in Flexible Pavement Design
2004
The work presented in this paper offers a contribution to understand to what extent different discretization modes for describing a whole day can affect the estimation of in-service durability of a flexible pavement, in relation with concomitant traffic flow fluctuations. Calculation of the stress–strain state was carried out with an elastic multi-layer model, and performance laws were implemented for verification of the major distress mechanisms that are able to affect the prediction of a flexible pavement’s service life. Results from the prediction of the fatigue life allow one to conclude that no big mistakes are made when evaluating the total damage by describing climatic conditions via…
Physical Properties of Latvian Hemp Fibres
2015
Each year more and more people focus on healthy, ecological and environmental-friendly living. Environmentally friendly lifestyle doesn’t mean that we are using only natural products, but attention is pointed to the manufacturing and production process also. The rapid development of recycled and biodegradable products causes expanding usage of hemp fibers both in household and technical textiles. The analysis of hemp cultivation and usage trends in the world and Europe shows that hemp cultivation and processing in Latvia has good perspectives. Product quality is influenced by raw materials. In this case it is hemp fiber descriptive characteristics. Hemp fibers are natural fibers and their p…
An Effective Multirestart Deterministic Annealing Metaheuristic for the Fleet Size and Mix Vehicle-Routing Problem with Time Windows
2008
This paper presents a new deterministic annealing metaheuristic for the fleet size and mix vehicle-routing problem with time windows. The objective is to service, at minimal total cost, a set of customers within their time windows by a heterogeneous capacitated vehicle fleet. First, we motivate and define the problem. We then give a mathematical formulation of the most studied variant in the literature in the form of a mixed-integer linear program. We also suggest an industrially relevant, alternative definition that leads to a linear mixed-integer formulation. The suggested metaheuristic solution method solves both problem variants and comprises three phases. In Phase 1, high-quality init…
A feasibility study of some DSM enabling solutions in small islands: The case of Lampedusa
2017
Abstract The paper addresses the issue of the transition from a traditional electrical system without automation to a newer active and smart system allowing the possibility of implementing Demand Side Management policies, for little islands not supplied by the main grid. In particular, the paper focuses on two main topics related to the definition of: • an effective control, monitoring and communication system as a tool for the full exploitation of the opportunities given by Demand Response policies; • some solutions for the automation of the end-users’ electrical installations, in order to offer to the utility flexibility to be used for the improvement of the generation and distribution ef…
Cost benefits of flexible hybrid cloud storage : Mitigating volume variation with shorter acquisition cycle
2016
The hybrid cloud storage is investigated as a case of concurrent sourcing.The paper introduces an analytical model for hybrid cloud storage costs.We study the role of acquisition cycle and volume variation in hybrid cloud costs.Shortening the reassessment interval reduces the volume non-stationarity.Shortening the reassessment interval reduces the total hybrid costs. Hybrid cloud storage combines cost-effective but inflexible private storage along with flexible but premium-priced public cloud storage. As a form of concurrent sourcing, it offers flexibility and cost benefits to organizations by allowing them to operate at a cost-optimal scale and scope under demand volume uncertainty. Howeve…
<title>Control and measuring buses with amplitude fiber optical sensors</title>
2004
This paper presents controlling-measuring buses (linear and quasi-linear) using amplitude properties of fiber-optics and fiber-optical sensors of typical and/or special construction. It refers to linear sensors and commonly used measuring OTDR method, as wel as to realizations with linear binary sensors in transmission networks. Presented advantages and parameters of such measuring structures. Presented main area of application buses and practical realizations, regarding typical needs in industrial measurements, points out technical and economical advantages, in opposition to difficult and expensive (but more accurate) technology of measuring networks based on polarization and interfering m…
Concrete softening effects on the axial capacity of RC jacketed circular columns
2016
Abstract Among the different strengthening techniques to repair RC structures, reinforced concrete (RC) jacketing is one of the most commonly adopted, especially for columns. Its wide application is due to its easy application and relatively reduced cost with respect to other methods (e.g. FRP wrapping, Shape Memory Alloy active confinement). The target of RC jacketing is to increase axial, flexural capacity and ductility of weak existing members by means of two main effects: confinement action provided by the jacket and composite action between external jacket and inner concrete. Different theoretical studies have been carried out to calculate the strength enhancement due to confinement ac…