Abstract: In this paper a novel method for multiple one dimensional real valued sinusoidal signal frequency estimation in the presence of additive Gaussian noise is postulated. A computationally simple frequency estimation method with efficient statistical performance is attractive in many array signal processing applications. The prime focus of this paper is to combine the subspace-based technique and a simple peak search approach. This paper presents a variant of the Propagator Method (PM), where a collaborative approach of SUMWE and Propagator method is applied in order to estimate the multiple real valued sine wave frequencies. A new data model is proposed, which gives the dimension of the signal subspace is equal to the number of frequencies present in the observation. But, the signal subspace dimension is twice the number of frequencies in the conventional MUSIC method for estimating frequencies of real-valued sinusoidal signal. The statistical analysis of the proposed method is studied, and the explicit expression of asymptotic (large-sample) mean-squared-error (MSE) or variance of the estimation error is derived. The performance of the method is demonstrated, and the theoretical analysis is substantiated through numerical examples. The proposed method can achieve sustainable high estimation accuracy and frequency resolution at a lower SNR, which is verified by simulation by comparing with conventional MUSIC, ESPRIT and Propagator Method.
Abstract: Properties of cement pastes with fine-ground ceramics
used as an alternative binder replacing Portland cement up to 20% of
its mass are investigated. At first, the particle size distribution of
cement and fine-ground ceramics is measured using laser analyser.
Then, the material properties are studied in the early hardening
period up to 28 days. The hydration process of studied materials is
monitored by electrical conductivity measurement using TDR
sensors. The changes of materials- structures within the hardening are
observed using pore size distribution measurement. The compressive
strength measurements are done as well. Experimental results show
that the replacement of Portland cement by fine-ground ceramics in
the amount of up to 20% by mass is acceptable solution from the
mechanical point of view. One can also assume similar physical
properties of designed materials to the reference material with only
Portland cement as binder.
Abstract: Renewable water resources are crucial production
variables in arid and semi-arid regions where intensive agriculture is
practiced to meet ever-increasing demand for food and fiber. This is
crucial for the Dez and Moghan command areas where water delivery
problems and adverse environmental issues are widespread. This
paper aims to identify major problems areas using on-farm surveys of
200 farmers, agricultural extensionists and water suppliers which was
complemented by secondary data and field observations during 2010-
2011 cultivating season. The SPSS package was used to analyze and
synthesis data. Results indicated inappropriate canal operations in
both schemes, though there was no unanimity about the underlying
causes. Inequitable and inflexible distribution was found to be rooted
in deficient hydraulic structures particularly in the main and
secondary canals. The inadequacy and inflexibility of water
scheduling regime was the underlying causes of recurring pest and
disease spread which often led to the decline of crop yield and
quality, although these were not disputed, the water suppliers were
not prepared to link with the deficiencies in the operation of the main
and secondary canals. They rather attributed these to the prevailing
salinity; alkalinity, water table fluctuations and leaching of the
valuable agro-chemical inputs from the plants- route zone with farreaching
consequences. Examples of these include the pollution of
ground and surface resources due to over-irrigation at the farm level
which falls under the growers- own responsibility. Poor irrigation
efficiency and adverse environmental problems were attributed to
deficient and outdated farming practices that were in turn rooted in
poor extension programs and irrational water charges.
Abstract: A CFD study on heat flux reduction in hypersonic flow with opposing jet has been conducted. Flowfield parameters, reattachment point position, surface pressure distributions and heat flux distributions are obtained and validated with experiments. The physical mechanism of heat reduction has been analyzed. When the opposing jet blows, the freestream is blocked off, flows to the edges and not interacts with the surface to form aerodynamic heating. At the same time, the jet flows back to form cool recirculation region, which reduces the difference in temperature between the surface and the nearby gas, and then reduces the heat flux. As the pressure ratio increases, the interface between jet and freestream is gradually pushed away from the surface. Larger the total pressure ratio is, lower the heat flux is. To study the effect of the intensity of opposing jet more reasonably, a new parameter RPA has been introduced by combining the flux and the total pressure ratio. The study shows that the same shock wave position and total heat load can be obtained with the same RPA with different fluxes and the total pressures, which means the new parameter could stand for the intensity of opposing jet and could be used to analyze the influence of opposing jet on flow field and aerodynamic heating.
Abstract: Since DVB-RCS has been successively implemented, the mobile communication on the multi-beam satellite communication is attractive attention. And the DVB-RCS standard sets up to support mobility of a RCST. In the case of the spot-beam satellite system, the received signal strength does not differ largely between the center and the boundary of the beam. Thus, the RSS based handoff detection algorithm is not benefit to the satellite system as a terrestrial system. Therefore we propose an Adaptive handoff detection algorithm based on RCST mobility information. Our handoff detection algorithm not only can be used as centralized handoff detection algorithm but also removes uncertainties of handoff due to the variation of RSS. Performances were compared with RSS based handoff algorithm. Simulation results show that the proposed handoff detection algorithm not only achieved better handoff and link degradation rate, but also achieved better forward link spectral efficiency.
Abstract: In the analysis of structures, the nonlinear effects due to large displacement, large rotation and materially-nonlinear are very important and must be considered for the reliable analysis. The non-linear fmite element analysis has potential as usable and reliable means for analyzing of civil structures with the availability of computer technology. In this research the large displacements and materially nonlinear behavior of shear wall is presented with developing of fmite element code using the standard Galerkin weighted residual formulation. Two-dimensional plane stress model was carried out to present the shear wall response. Total Lagangian formulation, which is computationally more effective, is used in the formulation of stiffness matrices and the Newton-Raphson method is applied for the solution of nonlinear transient equations. The details of the program formulation are highlighted and the results of the analyses are presented, along with a comparison of the response of the structure with Ansys software results. The presented model in this paper can be developed for nonlinear analysis of civil engineering structures with different material behavior and complicated geometry.
Abstract: In the paper we presented the possibility of application
collagen gels with active principle-s from marine algae extract and chlorhexidine salt in dental medicine. The hydro-alcoholic extracts
from marine algae have been used as they have been obtained. The extracts from marine algae and chlorhexidine salt (digluconate) are
incorporated in type I non-denatured fibrillar collagen matrixes. In order to obtain therapeutic effects at nanostructure level, it is important to know the rheological characteristics of the relevant mixtures of collagen gels and extracts from marine algae selected for use. In this survey we have studied mixtures made of non-denatured
fibrillar collagen hydro-gels where different concentrations of marine
algae have been incorporated. Based on the data obtained for the
shearing tensions, we have traced the rheograms – the diagrams for shearing tensions depending on the shearing speed values – from
which we have calculated the apparent viscosities as ratios between shearing tension and speed values, which have been figured in
relation to the shearing speed values, with a view to levelling
dependency.
Abstract: This work presents a new algorithm based on a combination of fuzzy (FUZ), Dynamic Programming (DP), and Genetic Algorithm (GA) approach for capacitor allocation in distribution feeders. The problem formulation considers two distinct objectives related to total cost of power loss and total cost of capacitors including the purchase and installation costs. The novel formulation is a multi-objective and non-differentiable optimization problem. The proposed method of this article uses fuzzy reasoning for sitting of capacitors in radial distribution feeders, DP for sizing and finally GA for finding the optimum shape of membership functions which are used in fuzzy reasoning stage. The proposed method has been implemented in a software package and its effectiveness has been verified through a 9-bus radial distribution feeder for the sake of conclusions supports. A comparison has been done among the proposed method of this paper and similar methods in other research works that shows the effectiveness of the proposed method of this paper for solving optimum capacitor planning problem.
Abstract: The purpose of this paper is to develop a typology
based on market orientation (MO) and innovation orientation (IO),
and to illustrate to what extent housing companies in Sweden fit
within this framework. A qualitative study on 11 public housing
companies in the central part of Sweden has been conducted by the
help of open and semi-structured questions for data collection. Four
public housing company types- i.e. reactive prospector, proactive
prospector, reactive defender and proactive defender have been
identified by the combination of MO-IO dimensions. Future research
can include other dimensions like entrepreneurship and network to
observe how it particularly affects MO. An empirical study can
compare public and private housing companies on the basis of MO
and IO dimensions. One major contribution of the paper is the
proposition of typology which can be used to describe public housing
companies and deciding their future course of actions.
Abstract: The velocity of a moving point in a general path is the vector quantity, which has both magnitude and direction. The magnitude or the direction of the velocity vector can change over time as a result of acceleration that the time rate of velocity changes. Acceleration analysis is important because inertial forces and inertial torques are proportional to rectilinear and angular accelerations accordingly. The loads must be determined in advance to ensure that a machine is adequately designed to handle these dynamic loads. For planar motion, the vector direction of acceleration is commonly separated into two elements: tangential and centripetal or radial components of a point on a rotating body. All textbooks in physics, kinematics and dynamics of machinery consider the magnitude of a radial acceleration at condition when a point rotates with a constant angular velocity and it means without acceleration. The magnitude of the tangential acceleration considered on a basis of acceleration for a rotating point. Such condition of presentation of magnitudes for two components of acceleration logically and mathematically is not correct and may cause further confusion in calculation. This paper presents new analytical expressions of the radial and absolute accelerations of a rotating point with acceleration and covers the gap in theoretical study of acceleration analysis.
Abstract: In spite of the advent of new materials, clay bricks
remain, arguably, the most popular construction materials today.
Nevertheless the low cost and versatility of clay bricks cannot always
be associated with high environmental and sustainable values,
especially in terms of raw material sources and manufacturing
processes. At the same time, the worldwide agricultural footprint is
fast growing, with vast agricultural land cultivation and active
expansion of the agro-based industry. The resulting large quantities of
agricultural wastes, unfortunately, are not always well managed or
utilised. These wastes can be recycled, such as by retrieving fibres
from disposed leaves and fruit bunches, and then incorporated in
brick-making. This way the clay bricks are made a 'greener' building
material and the discarded natural wastes can be reutilised, avoiding
otherwise wasteful landfill and harmful open incineration. This study
examined the physical and mechanical properties of clay bricks made
by adding two natural fibres to a clay-water mixture, with baked and
non-baked conditions. The fibres were sourced from pineapple leaves
(PF) and oil palm fruit bunch (OF), and added within the range of
0.25-0.75 %. Cement was added as a binder to the mixture at 5-15 %.
Although the two fibres had different effects on the bricks produced,
cement appeared to dominate the compressive strength. The
non-baked bricks disintegrated when submerged in water, while the
baked ones displayed cement-dependent characteristics in
water-absorption and density changes. Interestingly, further increase
in fibre content did not cause significant density decrease in both the
baked and non-baked bricks.
Abstract: The combustion of liquid fuel in the porous burner
(PB) was experimented to investigate evaporation mechanism and
combustion behavior. The diesel oil was used as fuel and the pebbles
carefully chosen in the same size like the solid sphere homogeneously
was adopted as the porous media. Two structures of the liquid porous
burner, i.e. the PB without and with installation of porous emitter
(PE), were performed. PE was installed by lower than PB with
distance of 20 cm. The pebbles having porosity (φ) of 0.45 and 0.52
were, respectively, used in PB and PE. The fuel was supplied dropwise
from the top through the PB and the combustion was occurred between
PB and PE. Axial profiles of temperature along the burner length were
measured to clarify the evaporation and combustion phenomena. The
pollutant emission characteristics were monitored at the burner exit.
From the experiment, it was found that the temperature profiles of both
structures decreased with the three ways swirling air flows (QA)
increasing. On the other hand, the temperature profiles increased with
fuel heat input (QF). Obviously, the profile of the porous burner
installed with PE was higher than that of the porous burner without
PE
Abstract: Sensor network applications are often data centric and
involve collecting data from a set of sensor nodes to be delivered
to various consumers. Typically, nodes in a sensor network are
resource-constrained, and hence the algorithms operating in these
networks must be efficient. There may be several algorithms available
implementing the same service, and efficient considerations may
require a sensor application to choose the best suited algorithm. In
this paper, we present a systematic evaluation of a set of algorithms
implementing the data gathering service. We propose a modular
infrastructure for implementing such algorithms in TOSSIM with
separate configurable modules for various tasks such as interest
propagation, data propagation, aggregation, and path maintenance.
By appropriately configuring these modules, we propose a number
of data gathering algorithms, each of which incorporates a different
set of heuristics for optimizing performance. We have performed
comprehensive experiments to evaluate the effectiveness of these
heuristics, and we present results from our experimentation efforts.
Abstract: Content-based Image Retrieval (CBIR) aims at searching image databases for specific images that are similar to a given query image based on matching of features derived from the image content. This paper focuses on a low-dimensional color based indexing technique for achieving efficient and effective retrieval performance. In our approach, the color features are extracted using the mean shift algorithm, a robust clustering technique. Then the cluster (region) mode is used as representative of the image in 3-D color space. The feature descriptor consists of the representative color of a region and is indexed using a spatial indexing method that uses *R -tree thus avoiding the high-dimensional indexing problems associated with the traditional color histogram. Alternatively, the images in the database are clustered based on region feature similarity using Euclidian distance. Only representative (centroids) features of these clusters are indexed using *R -tree thus improving the efficiency. For similarity retrieval, each representative color in the query image or region is used independently to find regions containing that color. The results of these methods are compared. A JAVA based query engine supporting query-by- example is built to retrieve images by color.
Abstract: The use of composite materials in offshore engineering for deep sea oil production riser systems has drawn considerable interest due to the potential weight savings and improvement in durability. The design of composite risers consists of two stages: (1) local design based on critical local load cases, and (2) global analysis of the full length composite riser under global loads and assessment of critical locations. In the first stage, eight different material combinations were selected and their laminate configurations optimised under local load considerations. Stage two includes a final local stress analysis of the critical sections of the riser under the combined loads determined in the global analysis. This paper describes two design methodologies of the composite riser to provide minimum structural weight and shows that the use of off angle fibre orientations in addition to axial and hoop reinforcements offer substantial weight savings and ensure the structural capacity.
Abstract: A series of 1-(1H-benzimidazol-2-yl)-3-(substituted phenyl)-2-propen-1-one were allowed to react with hydrazine hydrate and phenyl hydrazine in submitted reactions to get pyrazoline and phenyl pyrazoline derivatives. All the compounds entered for screening at the Tuberculosis Antimicrobial Acquisition and Coordinating Facility (TAACF) for their in vitro antibacterial activity against Mycobacterium tuberculosis H37Rv strain (ATCC 27294) using Microplate Alamar Blue Assay (MABA) susceptibility test. The results expressed as MIC (minimum inhibitory concentration) in μg/mL. Among the fifteen compounds, eight compounds were found to have MIC values less than 10 μg/mL. These were subjected for cytotoxicity assay in VERO cells to determine CC50 (cytotoxic concentration 50%) values and finally SI (Selectivity Index) were calculated. Compound (XV) 2-[5-(4- fluorophenyl)-1-phenyl-4,5-dihydro-1H-3-pyrazolyl]-1Hbenzimidazole was considered the best candidate of the series that could be a good starting point to develop new lead compounds in the fight against tuberculosis.
Abstract: The National Bridge Inventory (NBI) includes more
than 600,000 bridges within the United States of America.
Prestressed concrete girder bridges represent one of the most widely
used bridge systems. The majority of these girder bridges were
constructed using 0.5 and 0.6 inch diameter strands. The main
impediments to using larger strand diameters are: 1) lack of prestress
bed capacities, 2) lack of structural knowledge regarding the transfer
and development length of larger strands, and 3) the possibility of
developing wider end zone cracks upon strand release.
This paper presents a study about using 0.7 inch strands in girder
fabrication. Transfer and development length were evaluated, and
girders were fabricated using 0.7 inch strands at different spacings.
Results showed that 0.7 inch strands can be used at 2.0 inch spacing
without violating the AASHTO LRFD Specifications, while attaining
superior performance in shear and flexure.
Abstract: Support Vector Machine (SVM) is a statistical
learning tool developed to a more complex concept of
structural risk minimization (SRM). In this paper, SVM is
applied to signal detection in communication systems in the
presence of channel noise in various environments in the form
of Rayleigh fading, additive white Gaussian background noise
(AWGN), and interference noise generalized as additive color
Gaussian noise (ACGN). The structure and performance of
SVM in terms of the bit error rate (BER) metric is derived and
simulated for these advanced stochastic noise models and the
computational complexity of the implementation, in terms of
average computational time per bit, is also presented. The
performance of SVM is then compared to conventional binary
signaling optimal model-based detector driven by binary
phase shift keying (BPSK) modulation. We show that the
SVM performance is superior to that of conventional matched
filter-, innovation filter-, and Wiener filter-driven detectors,
even in the presence of random Doppler carrier deviation,
especially for low SNR (signal-to-noise ratio) ranges. For
large SNR, the performance of the SVM was similar to that of
the classical detectors. However, the convergence between
SVM and maximum likelihood detection occurred at a higher
SNR as the noise environment became more hostile.
Abstract: With the increasing number of on-chip components and the critical requirement for processing power, Chip Multiprocessor (CMP) has gained wide acceptance in both academia and industry during the last decade. However, the conventional bus-based onchip communication schemes suffer from very high communication delay and low scalability in large scale systems. Network-on-Chip (NoC) has been proposed to solve the bottleneck of parallel onchip communications by applying different network topologies which separate the communication phase from the computation phase. Observing that the memory bandwidth of the communication between on-chip components and off-chip memory has become a critical problem even in NoC based systems, in this paper, we propose a novel 3D NoC with on-chip Dynamic Random Access Memory (DRAM) in which different layers are dedicated to different functionalities such as processors, cache or memory. Results show that, by using our proposed architecture, average link utilization has reduced by 10.25% for SPLASH-2 workloads. Our proposed design costs 1.12% less execution cycles than the traditional design on average.
Abstract: The load frequency control problem of power systems has attracted a lot of attention from engineers and researchers over the years. Increasing and quickly changing load demand, coupled with the inclusion of more generators with high variability (solar and wind power generators) on the network are making power systems more difficult to regulate. Frequency changes are unavoidable but regulatory authorities require that these changes remain within a certain bound. Engineers are required to perform the tricky task of adjusting the control system to maintain the frequency within tolerated bounds. It is well known that to minimize frequency variations, a large proportional feedback gain (speed regulation constant) is desirable. However, this improvement in performance using proportional feedback comes about at the expense of a reduced stability margin and also allows some steady-state error. A conventional PI controller is then included as a secondary control loop to drive the steadystate error to zero. In this paper, we propose a robust controller to replace the conventional PI controller which guarantees performance and stability of the power system over the range of variation of the speed regulation constant. Simulation results are shown to validate the superiority of the proposed approach on a simple single-area power system model.