Abstract: Non-saturated soils that while saturation greatly
decrease their volume, have sudden settlement due to increasing
humidity, fracture and structural crack are called loess soils. Whereas
importance of civil projects including: dams, canals and
constructions bearing this type of soil and thereof problems, it is
required for carrying out more research and study in relation to loess
soils. This research studies shear strength parameters by using
grading test, Atterberg limit, compression, direct shear and
consolidation and then effect of using cement and lime additives on
stability of loess soils is studied. In related tests, lime and cement are
separately added to mixed ratios under different percentages of soil
and for different times the stabilized samples are processed and effect
of aforesaid additives on shear strength parameters of soil is studied.
Results show that upon passing time the effect of additives and
collapsible potential is greatly decreased and upon increasing
percentage of cement and lime the maximum dry density is
decreased; however, optimum humidity is increased. In addition,
liquid limit and plastic index is decreased; however, plastic index
limit is increased. It is to be noted that results of direct shear test
reveal increasing shear strength of soil due to increasing cohesion
parameter and soil friction angle.
Abstract: Time varying network induced delays in networked
control systems (NCS) are known for degrading control system-s
quality of performance (QoP) and causing stability problems. In
literature, a control method employing modeling of communication
delays as probability distribution, proves to be a better method. This
paper focuses on modeling of network induced delays as probability
distribution.
CAN and MIL-STD-1553B are extensively used to carry periodic
control and monitoring data in networked control systems.
In literature, methods to estimate only the worst-case delays for
these networks are available. In this paper probabilistic network
delay model for CAN and MIL-STD-1553B networks are given.
A systematic method to estimate values to model parameters from
network parameters is given. A method to predict network delay in
next cycle based on the present network delay is presented. Effect of
active network redundancy and redundancy at node level on network
delay and system response-time is also analyzed.
Abstract: The aim of this paper to characterize a larger set of
wavelet functions for implementation in a still image compression
system using SPIHT algorithm. This paper discusses important
features of wavelet functions and filters used in sub band coding to
convert image into wavelet coefficients in MATLAB. Image quality
is measured objectively using peak signal to noise ratio (PSNR) and
its variation with bit rate (bpp). The effect of different parameters is
studied on different wavelet functions. Our results provide a good
reference for application designers of wavelet based coder.
Abstract: Independent component analysis (ICA) is a computational method for finding underlying signals or components from multivariate statistical data. The ICA method has been successfully applied in many fields, e.g. in vision research, brain imaging, geological signals and telecommunications. In this paper, we apply the ICA method to an analysis of mass spectra of oligomeric species emerged from aluminium sulphate. Mass spectra are typically complex, because they are linear combinations of spectra from different types of oligomeric species. The results show that ICA can decomposite the spectral components for useful information. This information is essential in developing coagulation phases of water treatment processes.
Abstract: The present work compares the performance of three
turbulence modeling approach (based on the two-equation k -ε
model) in predicting erosive wear in multi-size dense slurry flow
through rotating channel. All three turbulence models include
rotation modification to the production term in the turbulent kineticenergy
equation. The two-phase flow field obtained numerically
using Galerkin finite element methodology relates the local flow
velocity and concentration to the wear rate via a suitable wear model.
The wear models for both sliding wear and impact wear mechanisms
account for the particle size dependence. Results of predicted wear
rates using the three turbulence models are compared for a large
number of cases spanning such operating parameters as rotation rate,
solids concentration, flow rate, particle size distribution and so forth.
The root-mean-square error between FE-generated data and the
correlation between maximum wear rate and the operating
parameters is found less than 2.5% for all the three models.
Abstract: In this work, we study the impact of dynamically changing link slowdowns on the stability properties of packetswitched networks under the Adversarial Queueing Theory framework. Especially, we consider the Adversarial, Quasi-Static Slowdown Queueing Theory model, where each link slowdown may take on values in the two-valued set of integers {1, D} with D > 1 which remain fixed for a long time, under a (w, p)-adversary. In this framework, we present an innovative systematic construction for the estimation of adversarial injection rate lower bounds, which, if exceeded, cause instability in networks that use the LIS (Longest-in- System) protocol for contention-resolution. In addition, we show that a network that uses the LIS protocol for contention-resolution may result in dropping its instability bound at injection rates p > 0 when the network size and the high slowdown D take large values. This is the best ever known instability lower bound for LIS networks.
Abstract: Whole genome duplication (WGD) increased the
number of yeast Saccharomyces cerevisiae chromosomes from 8 to
16. In spite of retention the number of chromosomes in the genome
of this organism after WGD to date, chromosomal rearrangement
events have caused an evolutionary distance between current genome
and its ancestor. Studies under evolutionary-based approaches on
eukaryotic genomes have shown that the rearrangement distance is an
approximable problem. In the case of S. cerevisiae, we describe that
rearrangement distance is accessible by using dedoubled adjacency
graph drawn for 55 large paired chromosomal regions originated
from WGD. Then, we provide a program extracted from a C program
database to draw a dedoubled genome adjacency graph for S.
cerevisiae. From a bioinformatical perspective, using the duplicated
blocks of current genome in S. cerevisiae, we infer that genomic
organization of eukaryotes has the potential to provide valuable
detailed information about their ancestrygenome.
Abstract: The paper presents the potential of fuzzy logic (FL-I)
and neural network techniques (ANN-I) for predicting the
compressive strength, for SCC mixtures. Six input parameters that is
contents of cement, sand, coarse aggregate, fly ash, superplasticizer
percentage and water-to-binder ratio and an output parameter i.e. 28-
day compressive strength for ANN-I and FL-I are used for modeling.
The fuzzy logic model showed better performance than neural
network model.
Abstract: Estimation of voltage stability based on optimal
filtering method is presented. PV curve is used as a tool for voltage stability analysis. Dynamic voltage stability estimation is done by
using particle filter method. Optimum value (nose point) of PV curve can be estimated by estimating parameter of PV curve equation
optimal value represents critical voltage and
condition at specified point of measurement. Voltage stability is then estimated by analyzing loading margin condition c stimating equation. This
maximum loading
ecified dynamically.
Abstract: A steady two-dimensional magnetohydrodynamics
flow and heat transfer over a stretching vertical sheet influenced by
radiation and porosity is studied. The governing boundary layer
equations of partial differential equations are reduced to a system of
ordinary differential equations using similarity transformation. The
system is solved numerically by using a finite difference scheme
known as the Keller-box method for some values of parameters,
namely the radiation parameter N, magnetic parameter M, buoyancy
parameter l , Prandtl number Pr and permeability parameter K. The
effects of the parameters on the heat transfer characteristics are
analyzed and discussed. It is found that both the skin friction
coefficient and the local Nusselt number decrease as the magnetic
parameter M and permeability parameter K increase. Heat transfer
rate at the surface decreases as the radiation parameter increases.
Abstract: Power cables are vulnerable to failure due to aging or
defects that occur with the passage of time under continuous
operation and loading stresses. PD detection and characterization
provide information on the location, nature, form and extent of the
degradation. As a result, PD monitoring has become an important
part of condition based maintenance (CBM) program among power
utilities. Online partial discharge (PD) localization of defect sources
in power cable system is possible using the time of flight method.
The information regarding the time difference between the main and
reflected pulses and cable length can help in locating the partial
discharge source along the cable length. However, if the length of
the cable is not known and the defect source is located at the extreme
ends of the cable or in the middle of the cable, then double ended
measurement is required to indicate the location of PD source. Use of
multiple sensors can also help in discriminating the cable PD or local/
external PD. This paper presents the experience and results from
online partial discharge measurements conducted in the laboratory
and the challenges in partial discharge source localization.
Abstract: In this study, effects of premixed and equivalence
ratios on CO and HC emissions of a dual fuel HCCI engine are
investigated. Tests were conducted on a single-cylinder engine with
compression ratio of 17.5. Premixed gasoline is provided by a
carburetor connected to intake manifold and equipped with a screw
to adjust premixed air-fuel ratio, and diesel fuel is injected directly
into the cylinder through an injector at pressure of 250 bars. A heater
placed at inlet manifold is used to control the intake charge
temperature. Optimal intake charge temperature results in better
HCCI combustion due to formation of a homogeneous mixture,
therefore, all tests were carried out over the optimum intake
temperature of 110-115 ºC. Timing of diesel fuel injection has a great
effect on stratification of in-cylinder charge and plays an important
role in HCCI combustion phasing. Experiments indicated 35 BTDC
as the optimum injection timing. Varying the coolant temperature in
a range of 40 to 70 ºC, better HCCI combustion was achieved at 50
ºC. Therefore, coolant temperature was maintained 50 ºC during all
tests. Simultaneous investigation of effective parameters on HCCI
combustion was conducted to determine optimum parameters
resulting in fast transition to HCCI combustion. One of the
advantages of the method studied in this study is feasibility of easy
and fast transition of typical diesel engine to a dual fuel HCCI
engine. Results show that increasing premixed ratio, while keeping
EGR rate constant, increases unburned hydrocarbon (UHC)
emissions due to quenching phenomena and trapping of premixed
fuel in crevices, but CO emission decreases due to increase in CO to
CO2 reactions.
Abstract: In the recent years multimedia traffic and in particular
VoIP services are growing dramatically. We present a new algorithm
to control the resource utilization and to optimize the voice codec
selection during SIP call setup on behalf of the traffic condition
estimated on the network path.
The most suitable methodologies and the tools that perform realtime
evaluation of the available bandwidth on a network path have
been integrated with our proposed algorithm: this selects the best
codec for a VoIP call in function of the instantaneous available
bandwidth on the path. The algorithm does not require any explicit
feedback from the network, and this makes it easily deployable over
the Internet. We have also performed intensive tests on real network
scenarios with a software prototype, verifying the algorithm
efficiency with different network topologies and traffic patterns
between two SIP PBXs.
The promising results obtained during the experimental validation
of the algorithm are now the basis for the extension towards a larger
set of multimedia services and the integration of our methodology
with existing PBX appliances.
Abstract: A diamond-like carbon (DLC) based solid-lubricant
film was designed and DLC films were successfully prepared using a
microwave plasma enhanced magnetron sputtering deposition
technology. Post-test characterizations including Raman
spectrometry, X-ray diffraction, nano-indentation test, adhesion test,
friction coefficient test were performed to study the influence of
substrate bias voltage on the mechanical properties of the W- and
S-doped DLC films. The results indicated that the W- and S-doped
DLC films also had the typical structure of DLC films and a better
mechanical performance achieved by the application of a substrate
bias of -200V.
Abstract: This paper aims to perform the second law analysis of
thermodynamics on the laminar film condensation of pure saturated
vapor flowing in the direction of gravity on an ellipsoid with variable
wall temperature. The analysis provides us understanding how the
geometric parameter- ellipticity and non-isothermal wall temperature
variation amplitude “A." affect entropy generation during film-wise
condensation heat transfer process. To understand of which
irreversibility involved in this condensation process, we derived an
expression for the entropy generation number in terms of ellipticity
and A. The result indicates that entropy generation increases with
ellipticity. Furthermore, the irreversibility due to finite temperature
difference heat transfer dominates over that due to condensate film
flow friction and the local entropy generation rate decreases with
increasing A in the upper half of ellipsoid. Meanwhile, the local
entropy generation rate enhances with A around the rear lower half of
ellipsoid.
Abstract: This paper focuses on wormhole attacks detection in wireless sensor networks. The wormhole attack is particularly challenging to deal with since the adversary does not need to compromise any nodes and can use laptops or other wireless devices to send the packets on a low latency channel. This paper introduces an easy and effective method to detect and locate the wormholes: Since beacon nodes are assumed to know their coordinates, the straight line distance between each pair of them can be calculated and then compared with the corresponding hop distance, which in this paper equals hop counts × node-s transmission range R. Dramatic difference may emerge because of an existing wormhole. Our detection mechanism is based on this. The approximate location of the wormhole can also be derived in further steps based on this information. To the best of our knowledge, our method is much easier than other wormhole detecting schemes which also use beacon nodes, and to those have special requirements on each nodes (e.g., GPS receivers or tightly synchronized clocks or directional antennas), ours is more economical. Simulation results show that the algorithm is successful in detecting and locating wormholes when the density of beacon nodes reaches 0.008 per m2.
Abstract: This paper presents three models which enable the
customisation of Universal Description, Discovery and Integration
(UDDI) query results, based on some pre-defined and/or real-time
changing parameters. These proposed models detail the requirements,
design and techniques which make ranking of Web service discovery
results from a service registry possible. Our contribution is two fold:
First, we present an extension to the UDDI inquiry capabilities. This
enables a private UDDI registry owner to customise or rank the query
results, based on its business requirements. Second, our proposal
utilises existing technologies and standards which require minimal
changes to existing UDDI interfaces or its data structures. We believe
these models will serve as valuable reference for enhancing the
service discovery methods within a private UDDI registry
environment.
Abstract: This paper discusses the theory behind the existence of an idealistic model for business network governance and uses a clarifying case-study, containing governance structures and processes within a business network framework. The case study from a German pharmaceutical industry company complements existing literature by providing a comprehensive explanation of the relations between supply chains and business networks, and also between supply chain management and business network governance. Supply chains and supply chain management are only one side of the interorganizational relationships and ensure short-term performance, while real-world governance structures are needed for ensuring the long-term existence of a supply chain. Within this context, a comprehensive model for business governance is presented. An interesting finding from the case study is that multiple business network governance systems co-exist within the evaluated supply chain.
Abstract: This study investigates the possibility providing gully
erosion map by the supervised classification of satellite images
(ETM+) in two mountainous and plain land types. These land types
were the part of Varamin plain, Tehran province, and Roodbar subbasin,
Guilan province, as plain and mountain land types,
respectively. The position of 652 and 124 ground control points were
recorded by GPS respectively in mountain and plain land types. Soil
gully erosion, land uses or plant covers were investigated in these
points. Regarding ground control points and auxiliary points, training
points of gully erosion and other surface features were introduced to
software (Ilwis 3.3 Academic). The supervised classified map of
gully erosion was prepared by maximum likelihood method and then,
overall accuracy of this map was computed. Results showed that the
possibility supervised classification of gully erosion isn-t possible,
although it need more studies for results generalization to other
mountainous regions. Also, with increasing land uses and other
surface features in plain physiography, it decreases the classification
of accuracy.
Abstract: Integration of process planning and scheduling
functions is necessary to achieve superior overall system
performance. This paper proposes a methodology for integration of
process planning and scheduling for prismatic component that can be
implemented in a company with existing departments. The developed
model considers technological constraints whereas available time for
machining in shop floor is the limiting factor to produce multiple
process plan (MPP). It takes advantage of MPP while guarantied the
fulfillment of the due dates via using overtime. This study has been
proposed to determinate machining parameters, tools, machine and
amount of over time within the minimum cost objective while
overtime is considered for this. At last the illustration shows that the
system performance is improved by as measured by cost and
compatible with due date.