6,486 research outputs found
DIVERSITY OF ETHNICITY AND STATE INVOLVEMENT ON URBAN INFORMALITY IN BEIRUT
Urban informality has become the dominant feature of urban growth on Beirut City and its periphery. Beirut context, as the rest of Lebanese cities, sheds light on a new era of controversy on urban informality. The appearance of urban informality in Beirut is due to the ways that the state being involved on such areas and its affect on shaping the urban fabric, the ways that the influence of various sociopolitical circumstances the country being passed through by which informal areas being established, and the complexity of ethnicity structure within Lebanese society. Understanding the diversity of the state power and ethnicity structure of the society during various periods of the establishment of informal housing areas would enable the state and housing professionals to provide a clear policy strategy to tackle urban informality. Each marginal area needs special treatment according to its religion and ethnicity structureâ to be remolded within the society.informality; urbanization; state; ethnicity; Lebanon.
Life-cycle of fatigue sensitive structures under uncertainty
Fatigue is the one of the main contributors to problems related to structural safety of civil and marine structures. Life-cycle management (LCM) techniques considering various uncertainties can be used to predict the safe service life of fatigue sensitive structures, plan for their future inspections and support the decision making process regarding maintenance and repair actions. This paper provides a brief overview of the LCM of fatigue sensitive civil and marine structures under uncertainty. Probabilistic performance prediction, inspection scheduling and maintenance optimization for such structures are discussed
A unified approach for numerical simulation of viscous compressible and incompressible flows over adiabatic and isothermal walls
A new formulation (including the choice of variables, their non-dimensionalization, and the form of the artificial viscosity) is proposed for the numerical solution of the full Navier-Stokes equations for compressible and incompressible flows with heat transfer. With the present approach, the same code can be used for constant as well as variable density flows. The changes of the density due to pressure and temperature variations are identified and it is shown that the low Mach number approximation is a special case. At zero Mach number, the density changes due to the temperature variation are accounted for, mainly through a body force term in the momentum equation. It is also shown that the Boussinesq approximation of the buoyancy effects in an incompressible flow is a special case. To demonstrate the new capability, three examples are tested. Flows in driven cavities with adiabatic and isothermal walls are simulated with the same code as well as incompressible and supersonic flows over a wall with and without a groove. Finally, viscous flow simulations of an oblique shock reflection from a flat plate are shown to be in good agreement with the solutions available in literature
Design of Observer-Based Robust Power System Stabilizers
Power systems are subject to undesirable small oscillations that might grow to cause system shutdown and consequently great loss of national economy. The present manuscript  proposes two  designs for observer-based robust power system stabilizer (PSS) using Linear Matrix Inequality (LMI) approach to damp such oscillations. A model to describe power system dynamics for different loads is derived in the norm-bounded form. The first controller design is based on the derived model to achieve  robust stability against load variation. The design is based on a new Bilinear matrix inequality (BMI) condition. The BMI optimization  is solved interatively in terms of Linear Matrix Inequality (LMI) framework. The condition contains a symmetric positive definite full matrix to be obtained, rather than the commonly used block diagonal form. The difficulty in finding a feasible solution is thus alleviated. The resulting LMI is of small size, easy to solve. The second PSS design shifts the closed loop poles in a desired region so as to achieve a favorite  settling time and damping ratio via a non-iterative solution to a set of LMIs.  The approach provides a systematic way to design a robust output feedback PSS which  guarantees good dynamic performance for different loads. Simulation results based on single-machine and multi-machine power system models verify the ability of the proposed PSS to satisfy control objectives for a wide range of load conditions
ECONOMICS OF PRODUCTIVE TRAITS OF SOME EGG-LAYER STRAINS UNDER EGYPTIAN CONDITIONS
University College of North Wales, Bangor, Gwynedd LL57 2UW Wales, Inited KingdomAverage Cost Curve, Profitabilityu, Mortality Rate, Eggs Yield per Hen Housed Per Month, Feed Consumption, Farm Management, Livestock Production/Industries, Production Economics, Productivity Analysis, Research Methods/ Statistical Methods,
Interleaving Gains for Receive Diversity Schemes of Distributed Turbo Codes in Wireless HalfâDuplex Relay Channels
This paper proposes the interleaving gain in two different distributed turbo-coding schemes: Distributed Turbo Codes (DTC) and Distributed Multiple Turbo Codes (DMTC) for half-duplex relay system as an extension of our previous work on turbo coding interleaver design for direct communication channel. For these schemes with half-duplex constraint, the source node transmits its information with the parity bit sequence(s) to both the relay and the destination nodes during the first phase. The relay received the data from the source and process it by using decode and forward protocol. For the second transmission period, the decoded systematic data at relay is interleaved and re-encoded by a Recursive Systematic Convolutional (RSC) encoder and forwarded to the destination. At destination node, the signals received from the source and relay are processed by using turbo log-MAP iterative decoding for retrieving the original information bits. We demonstrate via simulations that the interleaving gain has a large effect with DTC scheme when we use only one RSC encoder at both the source and relay with best performance when using Modified Matched S-Random (MMSR) interleaver. Furthermore, by designing a Chaotic Pseudo Random Interleaver (CPRI) as an outer interleaver at the source node instead of classical interleavers, our scheme can add more secure channel conditions
The Dahshour (Egypt) Earthquake of 12th of October 1992
On the 12th of October, 1992 an earthquake of 5. 7 moment magnitude hit Dahshour (Egypt) and the surrounding area. The characteristics of the building stock exposed to this earthquake is firstly presented in the paper. Then, the Dahshour earthquake is discussed in terms of the lessons that can be learned by engineers. The paper presents a short description of the geotechnical effects and the observed patterns of damage of the existing building categories and monuments. Finally, a list of the most important conclusions is introduced
Semiclassical Hartree-Fock theory of a rotating Bose-Einstein condensation
In this paper, we investigate the thermodynamic behavior of a rotating
Bose-Einstein condensation with non-zero interatomic interactions
theoretically. The analysis relies on a semiclassical Hartree-Fock
approximation where an integral is performed over the phase space and function
of the grand canonical ensemble is derived. Subsequently, we use this result to
derive several thermodynamic quantities including the condensate fraction,
critical temperature, entropy and heat capacity. Thereby, we investigate the
effect of the rotation rate and interactions parameter on the thermodynamic
behavior. The role of finite size is discussed. Our approach can be extended to
consider the rotating condensate in optical potential
Characterisation of the mechanical and thermal degradation behaviour of natural fibres for lightweight automotive applications
It is well established that light-weighting of automotive parts leads to reduced carbon emissions over vehicle lifetime. Mineral fibres and fillers have a relatively high density and may require high levels of energy in their production, resulting in a large carbon footprint. Natural fibres have been identified as a potential candidate to substitute mineral fillers in automotive application of thermoplastic matrix composites. This paper focuses on the characterisation of the mechanical and thermal degradation of two types of natural fibres (date palm and coir fibres) as part of an evaluation of their potential for the substitution of high density mineral fillers with more environmentally friendly lower density natural fibre reinforcements
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