Abstract: Bond graph models of an electrical transformer
including the nonlinear saturation are presented. These models
determine the relation between self and mutual inductances, and
the leakage and magnetizing inductances of power transformers
with two and three windings using the properties of a bond
graph. The modelling and analysis using this methodology to
three phase power transformers or transformers with internal
incipient faults can be extended.
Abstract: In-place sorting algorithms play an important role in many fields such as very large database systems, data warehouses, data mining, etc. Such algorithms maximize the size of data that can be processed in main memory without input/output operations. In this paper, a novel in-place sorting algorithm is presented. The algorithm comprises two phases; rearranging the input unsorted array in place, resulting segments that are ordered relative to each other but whose elements are yet to be sorted. The first phase requires linear time, while, in the second phase, elements of each segment are sorted inplace in the order of z log (z), where z is the size of the segment, and O(1) auxiliary storage. The algorithm performs, in the worst case, for an array of size n, an O(n log z) element comparisons and O(n log z) element moves. Further, no auxiliary arithmetic operations with indices are required. Besides these theoretical achievements of this algorithm, it is of practical interest, because of its simplicity. Experimental results also show that it outperforms other in-place sorting algorithms. Finally, the analysis of time and space complexity, and required number of moves are presented, along with the auxiliary storage requirements of the proposed algorithm.
Abstract: This paper gives an overview of the mapping
mechanism of SEAM-a methodology for the automatic generation of
knowledge models and its mapping onto Java codes. It discusses the
rules that will be used to map the different components in the
knowledge model automatically onto Java classes, properties and
methods. The aim of developing this mechanism is to help in the
creation of a prototype which will be used to validate the knowledge
model which has been generated automatically. It will also help to
link the modeling phase with the implementation phase as existing
knowledge engineering methodologies do not provide for proper
guidelines for the transition from the knowledge modeling phase to
development phase. This will decrease the development overheads
associated to the development of Knowledge Based Systems.
Abstract: Data clustering is an important data exploration technique
with many applications in data mining. We present an enhanced
version of the well known single link clustering algorithm. We will
refer to this algorithm as DCBOR. The proposed algorithm alleviates
the chain effect by removing the outliers from the given dataset.
So this algorithm provides outlier detection and data clustering
simultaneously. This algorithm does not need to update the distance
matrix, since the algorithm depends on merging the most k-nearest
objects in one step and the cluster continues grow as long as possible
under specified condition. So the algorithm consists of two phases;
at the first phase, it removes the outliers from the input dataset. At
the second phase, it performs the clustering process. This algorithm
discovers clusters of different shapes, sizes, densities and requires
only one input parameter; this parameter represents a threshold for
outlier points. The value of the input parameter is ranging from 0 to
1. The algorithm supports the user in determining an appropriate
value for it. We have tested this algorithm on different datasets
contain outlier and connecting clusters by chain of density points,
and the algorithm discovers the correct clusters. The results of
our experiments demonstrate the effectiveness and the efficiency of
DCBOR.
Abstract: Scalability poses a severe threat to the existing
DRAM technology. The capacitors that are used for storing and
sensing charge in DRAM are generally not scaled beyond 42nm.
This is because; the capacitors must be sufficiently large for reliable
sensing and charge storage mechanism. This leaves DRAM memory
scaling in jeopardy, as charge sensing and storage mechanisms
become extremely difficult. In this paper we provide an overview of
the potential and the possibilities of using Phase Change Memory
(PCM) as an alternative for the existing DRAM technology. The
main challenges that we encounter in using PCM are, the limited
endurance, high access latencies, and higher dynamic energy
consumption than that of the conventional DRAM. We then provide
an overview of various methods, which can be employed to
overcome these drawbacks. Hybrid memories involving both PCM
and DRAM can be used, to achieve good tradeoffs in access latency
and storage density. We conclude by presenting, the results of these
methods that makes PCM a potential replacement for the current
DRAM technology.
Abstract: Nanoemulsions are a class of emulsions with a droplet
size in the range of 50–500 nm and have attracted a great deal of
attention in recent years because it is unique characteristics. The
physicochemical properties of nanoemulsion suggests that it can be
successfully used to recover the residual oil which is trapped in the
fine pore of reservoir rock by capillary forces after primary and
secondary recovery. Oil-in-water nanoemulsion which can be formed
by high-energy emulsification techniques using specific surfactants
can reduce oil-water interfacial tension (IFT) by 3-4 orders of
magnitude. The present work is aimed on characterization of oil-inwater
nanoemulsion in terms of its phase behavior, morphological
studies; interfacial energy; ability to reduce the interfacial tension and
understanding the mechanisms of mobilization and displacement of
entrapped oil blobs by lowering interfacial tension both at the
macroscopic and microscopic level. In order to investigate the
efficiency of oil-water nanoemulsion in enhanced oil recovery
(EOR), experiments were performed to characterize the emulsion in
terms of their physicochemical properties and size distribution of the
dispersed oil droplet in water phase. Synthetic mineral oil and a series
of surfactants were used to prepare oil-in-water emulsions.
Characterization of emulsion shows that it follows pseudo-plastic
behaviour and drop size of dispersed oil phase follows lognormal
distribution. Flooding experiments were also carried out in a
sandpack system to evaluate the effectiveness of the nanoemulsion as
displacing fluid for enhanced oil recovery. Substantial additional
recoveries (more than 25% of original oil in place) over conventional
water flooding were obtained in the present investigation.
Abstract: Hypersonic flows around spatial vehicles during their
reentry phase in planetary atmospheres are characterized by intense
aerothermal phenomena. The aim of this work is to analyze high
temperature flows around an axisymmetric blunt body taking into
account chemical and vibrational non-equilibrium for air mixture
species. For this purpose, a finite volume methodology is employed
to determine the supersonic flow parameters around the axisymmetric
blunt body, especially at the stagnation point and along the wall of
spacecraft for several altitudes. This allows the capture shock wave
before a blunt body placed in supersonic free stream. The numerical
technique uses the Flux Vector Splitting method of Van Leer. Here,
adequate time stepping parameter, along with CFL coefficient and
mesh size level are selected to ensure numerical convergence, sought
with an order of 10-8
Abstract: It is not easy to imagine how the existing city can be
converted to the principles of sustainability, however, the need for
innovation, requires a pioneering phase which must address the main
problems of rehabilitation of the operating models of the city. Today,
however, there is a growing awareness that the identification and
implementation of policies and measures to promote the adaptation,
resilience and reversibility of the city, require the contribution of our
discipline. This breakthrough is present in some recent international
experiences of Climate Plans, in which the envisaged measures are
closely interwoven with those of urban planning. These experiences,
provide some answers principle questions, such as: how the strategies
to combat climate can be integrated in the instruments of the local
government; what new and specific analysis must be introduced in
urban planning in order to understand the issues of urban
sustainability, and how the project compares with different spatial
scales.
Abstract: Multiphasing of dc-dc converters has been known to give technical and economical benefits to low voltage high power buck regulator modules. A major advantage of multiphasing dc-dc converters is the improvement of input and output performances in the buck converter. From this aspect, a potential use would be in renewable energy where power quality plays an important factor. This paper presents the design of a 2-phase 200W boost converter for battery charging application. Analysis of results from hardware measurement of the boost converter demonstrates the benefits of using multiphase. Results from the hardware prototype of the 2-phase boost converter further show the potential extension of multiphase beyond its commonly used low voltage high current domains.
Abstract: Bean common mosaic necrosis virus (BCMNV) is a
potyvirus with a worldwide distribution. This virus causes serious
economic losses in Iran in many leguminoses. During 20008,
samples were collected from soybeans fields in Tehran Province.
Four isolates (S1, S2 and S3) were inoculated on 15 species of
Cucurbitaceae, Chenopodiaceae, Solanacae and Leguminosae.
Chenopodium quinoa and C. amaranticolor.
Did not developed any symptoms.all isolates caused mosaic
symptoms on Phaseolus vulgaris cv. Red Kidney and P. vulgaris cv.
Bountiful. The molecular weights of coat protein using SDS-PAGE
and western blotting were estimated at 33 kDa. Reverse transcription
polymerase chain reaction (RT-PCR) was performed using one
primer pairs designed by L. XU et al. An approximately 920 bp
fragment was amplified with a specific primer.
Abstract: To support mobility in ATM networks, a number of
technical challenges need to be resolved. The impact of handoff
schemes in terms of service disruption, handoff latency, cost
implications and excess resources required during handoffs needs to
be addressed. In this paper, a one phase handoff and route
optimization solution using reserved PVCs between adjacent ATM
switches to reroute connections during inter-switch handoff is
studied. In the second phase, a distributed optimization process is
initiated to optimally reroute handoff connections. The main
objective is to find the optimal operating point at which to perform
optimization subject to cost constraint with the purpose of reducing
blocking probability of inter-switch handoff calls for delay tolerant
traffic. We examine the relation between the required bandwidth
resources and optimization rate. Also we calculate and study the
handoff blocking probability due to lack of bandwidth for resources
reserved to facilitate the rapid rerouting.
Abstract: The current methods of predictive controllers are
utilized for those processes in which the rate of output variations is
not high. For such processes, therefore, stability can be achieved by
implementing the constrained predictive controller or applying
infinite prediction horizon. When the rate of the output growth is
high (e.g. for unstable nonminimum phase process) the stabilization
seems to be problematic. In order to avoid this, it is suggested to
change the method in the way that: first, the prediction error growth
should be decreased at the early stage of the prediction horizon, and
second, the rate of the error variation should be penalized. The
growth of the error is decreased through adjusting its weighting
coefficients in the cost function. Reduction in the error variation is
possible by adding the first order derivate of the error into the cost
function. By studying different examples it is shown that using these
two remedies together, the closed-loop stability of unstable
nonminimum phase process can be achieved.
Abstract: We present an explicit expression to estimate driving voltage attenuation through RC networks representation of an ultrahigh- speed image sensor. Elmore delay metric for a fundamental RC chain is employed as the first-order approximation. By application of dimensional analysis to SPICE simulation data, we found a simple expression that significantly improves the accuracy of the approximation. Estimation error of the resultant expression for uniform RC networks is less than 2%. Similarly, another simple closed-form model to estimate 50 % delay through fundamental RC networks is also derived with sufficient accuracy. The framework of this analysis can be extended to address delay or attenuation issues of other VLSI structures.
Abstract: This paper presents design trade-off and performance impacts of
the amount of pipeline phase of control path signals in a wormhole-switched
network-on-chip (NoC). The numbers of the pipeline phase of the control
path vary between two- and one-cycle pipeline phase. The control paths
consist of the routing request paths for output selection and the arbitration
paths for input selection. Data communications between on-chip routers are
implemented synchronously and for quality of service, the inter-router data
transports are controlled by using a link-level congestion control to avoid
lose of data because of an overflow. The trade-off between the area (logic
cell area) and the performance (bandwidth gain) of two proposed NoC router
microarchitectures are presented in this paper. The performance evaluation is
made by using a traffic scenario with different number of workloads under
2D mesh NoC topology using a static routing algorithm. By using a 130-nm
CMOS standard-cell technology, our NoC routers can be clocked at 1 GHz,
resulting in a high speed network link and high router bandwidth capacity
of about 320 Gbit/s. Based on our experiments, the amount of control path
pipeline stages gives more significant impact on the NoC performance than
the impact on the logic area of the NoC router.
Abstract: This study was designed to formulate,
pharmaceutically evaluate a topical skin-care cream (w/o emulsion)
of Aloe Vera versus its vehicle (Base) as control and determine their
effects on Stratum Corneum (SC) water content and Transepidermal
water loss (TEWL). Base containing no extract and a Formulation
containing 3% concentrated extract of Aloe Vera was developed by
entrapping in the inner aqueous phase of w/o emulsion (cream).
Lemon oil was incorporated to improve the odor. Both the Base and
Formulation were stored at 8°C ±0.1°C (in refrigerator), 25°C±0.1°C,
40°C±0.1°C and 40°C± 0.1°C with 75% RH (in incubator) for a
period of 4 weeks to predict their stability. The evaluation parameters
consisted of color, smell, type of emulsion, phase separation,
electrical conductivity, centrifugation, liquefaction and pH. Both the
Base and Formulation were applied to the cheeks of 21 healthy
human volunteers for a period of 8 weeks Stratum corneum (SC)
water content and Transepidermal water loss (TEWL) were
monitored every week to measure any effect produced by these
topical creams. The expected organoleptic stability of creams was
achieved from 4 weeks in-vitro study period. Odor was disappeared
with the passage of time due to volatilization of lemon oil. Both the
Base and Formulation produced significant (p≤0.05) changes in
TEWL with respect to time. SC water content was significantly
(p≤0.05) increased by the Formulation while the Base has
insignificant (p 0.05) effects on SC water content. The newly
formulated cream of Aloe Vera, applied is suitable for improvement
and quantitative monitoring of skin hydration level (SC water
content/ moisturizing effects) and reducing TEWL in people with dry
skin.
Abstract: There has been a growing interest in utilizing surfactants in remediation processes to separate the hydrophobic volatile organic compounds (HVOCs) from aqueous solution. One attractive process is cloud point extraction (CPE), which utilizes nonionic surfactants as a separating agent. Since the surfactant cost is a key determination of the economic viability of the process, it is important that the surfactants are recycled and reused. This work aims to study the performance of the co-current vacuum stripping using a packed column for HVOCs removal from contaminated surfactant solution. Six types HVOCs are selected as contaminants. The studied surfactant is the branched secondary alcohol ethoxylates (AEs), Tergitol TMN-6 (C14H30O2). The volatility and the solubility of HVOCs in surfactant system are determined in terms of an apparent Henry’s law constant and a solubilization constant, respectively. Moreover, the HVOCs removal efficiency of vacuum stripping column is assessed in terms of percentage of HVOCs removal and the overall liquid phase volumetric mass transfer coefficient. The apparent Henry’s law constant of benzenz , toluene, and ethyl benzene were 7.00×10-5, 5.38×10-5, 3.35× 10-5 respectively. The solubilization constant of benzene, toluene, and ethyl benzene were 1.71, 2.68, 7.54 respectively. The HVOCs removal for all solute were around 90 percent.
Abstract: En bloc assumes modeling all phases of the orthostatic test with the only one mathematical model, which allows the complex parametric view of orthostatic response. The work presents the implementation of a mathematical model for processing of the measurements of systolic, diastolic blood pressure and heart rate performed on volunteers during orthostatic test. The original assumption of model hypothesis that every postural change means only one Stressor, did not complying with the measurements of physiological circulation factor-time profiles. Results of the identification support the hypothesis that second postural change of orthostatic test causes induced Stressors, with the observation of a physiological regulation mechanism. Maximal demonstrations are on the heart rate and diastolic blood pressure-time profile, minimal are for the measurements of the systolic blood pressure. Presented study gives a new view on orthostatic test with impact on clinical practice.
Abstract: Nanostructured materials have attracted many
researchers due to their outstanding mechanical and physical
properties. For example, carbon nanotubes (CNTs) or carbon
nanofibres (CNFs) are considered to be attractive reinforcement
materials for light weight and high strength metal matrix composites.
These composites are being projected for use in structural
applications for their high specific strength as well as functional
materials for their exciting thermal and electrical characteristics. The
critical issues of CNT-reinforced MMCs include processing
techniques, nanotube dispersion, interface, strengthening mechanisms
and mechanical properties. One of the major obstacles to the effective
use of carbon nanotubes as reinforcements in metal matrix
composites is their agglomeration and poor distribution/dispersion
within the metallic matrix. In order to tap into the advantages of the
properties of CNTs (or CNFs) in composites, the high dispersion of
CNTs (or CNFs) and strong interfacial bonding are the key issues
which are still challenging. Processing techniques used for synthesis
of the composites have been studied with an objective to achieve
homogeneous distribution of carbon nanotubes in the matrix.
Modified mechanical alloying (ball milling) techniques have emerged
as promising routes for the fabrication of carbon nanotube (CNT)
reinforced metal matrix composites. In order to obtain a
homogeneous product, good control of the milling process, in
particular control of the ball movement, is essential. The control of
the ball motion during the milling leads to a reduction in grinding
energy and a more homogeneous product. Also, the critical inner
diameter of the milling container at a particular rotational speed can
be calculated. In the present work, we use conventional and modified
mechanical alloying to generate a homogenous distribution of 2 wt.
% CNT within Al powders. 99% purity Aluminium powder (Acros,
200mesh) was used along with two different types of multiwall
carbon nanotube (MWCNTs) having different aspect ratios to
produce Al-CNT composites. The composite powders were processed
into bulk material by compaction, and sintering using a cylindrical
compaction and tube furnace. Field Emission Scanning electron
microscopy (FESEM), X-Ray diffraction (XRD), Raman
spectroscopy and Vickers macro hardness tester were used to
evaluate CNT dispersion, powder morphology, CNT damage, phase
analysis, mechanical properties and crystal size determination.
Despite the success of ball milling in dispersing CNTs in Al powder,
it is often accompanied with considerable strain hardening of the Al
powder, which may have implications on the final properties of the
composite. The results show that particle size and morphology vary
with milling time. Also, by using the mixing process and sonication
before mechanical alloying and modified ball mill, dispersion of the
CNTs in Al matrix improves.
Abstract: Image coding based on clustering provides immediate
access to targeted features of interest in a high quality decoded
image. This approach is useful for intelligent devices, as well as for
multimedia content-based description standards. The result of image
clustering cannot be precise in some positions especially on pixels
with edge information which produce ambiguity among the clusters.
Even with a good enhancement operator based on PDE, the quality of
the decoded image will highly depend on the clustering process. In
this paper, we introduce an ambiguity cluster in image coding to
represent pixels with vagueness properties. The presence of such
cluster allows preserving some details inherent to edges as well for
uncertain pixels. It will also be very useful during the decoding phase
in which an anisotropic diffusion operator, such as Perona-Malik,
enhances the quality of the restored image. This work also offers a
comparative study to demonstrate the effectiveness of a fuzzy
clustering technique in detecting the ambiguity cluster without losing
lot of the essential image information. Several experiments have been
carried out to demonstrate the usefulness of ambiguity concept in
image compression. The coding results and the performance of the
proposed algorithms are discussed in terms of the peak signal-tonoise
ratio and the quantity of ambiguous pixels.
Abstract: This paper develops an unscented grid-based filter
and a smoother for accurate nonlinear modeling and analysis
of time series. The filter uses unscented deterministic sampling
during both the time and measurement updating phases, to approximate
directly the distributions of the latent state variable. A
complementary grid smoother is also made to enable computing
of the likelihood. This helps us to formulate an expectation
maximisation algorithm for maximum likelihood estimation of
the state noise and the observation noise. Empirical investigations
show that the proposed unscented grid filter/smoother compares
favourably to other similar filters on nonlinear estimation tasks.