Abstract: We estimate snow velocity and snow drift density on hilly terrain under the assumption that the drifting snow mass can be represented using a micro-continuum approach (i.e. using a nonclassical mechanics approach assuming a class of fluids for which basic equations of mass, momentum and energy have been derived). In our model, the theory of coupled stress fluids proposed by Stokes [1] has been employed for the computation of flow parameters. Analyses of bulk drift velocity, drift density, drift transport and mass transport of snow particles have been carried out and computations made, considering various parametric effects. Results are compared with those of classical mechanics (logarithmic wind profile). The results indicate that particle size affects the flow characteristics significantly.
Abstract: Phase locked loops (PLL) and delay locked loops (DLL) play an important role in establishing coherent references (phase of carrier and symbol timing) in digital communication systems. Fully digital receiver including digital carrier synchronizer and symbol timing synchronizer fulfils the conditions for universal multi-mode communication receiver with option of symbol rate setting over several digit places and long-term stability of requirement parameters. Afterwards it is necessary to realize PLL and DLL in synchronizer in digital form and to approach to these subsystems as a discrete representation of analog template. Analysis of discrete phase locked loop (DPLL) or discrete delay locked loop (DDLL) and technique to determine their characteristics based on analog (continuous-time) template is performed in this posed paper. There are derived transmission response and error function for 1st order discrete locked loop and resulting equations and graphical representations for 2nd order one. It is shown that the spectrum translation due to sampling takes effect at frequency characteristics computing for specific values of loop parameters.
Abstract: The importance of nurturing, accumulating, and efficiently deploying knowledge resources through formal structures and organisational mechanisms is well understood. Recent trends in knowledge management (KM) highlight that the effective creation and transfer of knowledge can also rely upon extra-organisational channels, such as, informal networks. The perception exists that the role of informal networks in knowledge creation and performance has been underestimated in the organisational context. Literature indicates that many managers fail to comprehend and successfully exploit the potential role of informal networks to create value for their organisations. This paper investigates: 1) whether managers share work-specific knowledge with informal contacts within and outside organisational boundaries; and 2) what do they think is the importance of this knowledge collaboration in their learning and work outcomes.
Abstract: The mechanical properties including flexural and
tensile of neat vinyl ester and polymer based on layered silicate
nanocomposite materials are discussed. The addition of layered
silicate into the polymer matrix increased the tensile and flexural
modulus up to 1 wt.% clay loading. The incorporation of more clay
resulted in decreasing the mechanical properties which was traced to
the existence of aggregation layers. Likewise, up to 1 wt.% clay
loading, the thermal behaviour showed significant improvements and
at higher clay loading the thermal pattern was reduced. The
aggregation layers imparted a negative impact on the overall
mechanical and thermal properties. Wide Angle X-ray Diffraction,
Scanning Electron Microscopy and Transmission Electron
Microscopy were utilised in order to characterise the interlamellar
structure of nanocomposites.
Abstract: Process-oriented software development is a new
software development paradigm in which software design is modeled
by a business process which is in turn translated into a process
execution language for execution. The building blocks of this
paradigm are software units that are composed together to work
according to the flow of the business process. This new paradigm
still exhibits the characteristic of the applications built with the
traditional software component technology. This paper discusses an
approach to apply a traditional technique for software component
fabrication to the design of process-oriented software units, called
process components. These process components result from
decomposing a business process of a particular application domain
into subprocesses, and these process components can be reused to
design the business processes of other application domains. The
decomposition considers five managerial goals, namely cost
effectiveness, ease of assembly, customization, reusability, and
maintainability. The paper presents how to design or decompose
process components from a business process model and measure
some technical features of the design that would affect the
managerial goals. A comparison between the measurement values
from different designs can tell which process component design is
more appropriate for the managerial goals that have been set. The
proposed approach can be applied in Web Services environment
which accommodates process-oriented software development.
Abstract: In the context of sensor networks, where every few
dB saving counts, the novel node cooperation schemes are reviewed
where MIMO techniques play a leading role. These methods could be
treated as joint approach for designing physical layer of their
communication scenarios. Then we analyzed the BER performance
of transmission diversity schemes under a general fading channel
model and proposed a power allocation strategy to the transmitting
sensor nodes. This approach is then compared to an equal-power
assignment method and its performance enhancement is verified by
the simulation. Another key point of the contribution lies in the
combination of optimal power allocation and sensor nodes-
cooperation in a transmission diversity regime (MISO). Numerical
results are given through figures to demonstrate the optimality and
efficiency of proposed combined approach.
Abstract: The presence of harmonic in power system is a major
concerned to power engineers for many years. With the increasing
usage of nonlinear loads in power systems, the harmonic pollution
becomes more serious. One of the widely used computation
algorithm for harmonic analysis is fast Fourier transform (FFT). In
this paper, a harmonic analyzer using FFT was implemented on
TMS320C6713 DSK. The supply voltage of 240 V 59 Hz is stepped
down to 5V using a voltage divider in order to match the power
rating of the DSK input. The output from the DSK was displayed on
oscilloscope and Code Composer Studio™ software. This work has
demonstrated the possibility of analyzing the 240V power supply
harmonic content using the DSK board.
Abstract: Speed estimation is one of the important and practical tasks in machine vision, Robotic and Mechatronic. the availability of high quality and inexpensive video cameras, and the increasing need for automated video analysis has generated a great deal of interest in machine vision algorithms. Numerous approaches for speed estimation have been proposed. So classification and survey of the proposed methods can be very useful. The goal of this paper is first to review and verify these methods. Then we will propose a novel algorithm to estimate the speed of moving object by using fuzzy concept. There is a direct relation between motion blur parameters and object speed. In our new approach we will use Radon transform to find direction of blurred image, and Fuzzy sets to estimate motion blur length. The most benefit of this algorithm is its robustness and precision in noisy images. Our method was tested on many images with different range of SNR and is satisfiable.
Abstract: This work presents a matched field processing (MFP)
algorithm based on Dopplerlet transform for estimating the motion
parameters of a sound source moving along a straight line and with a
constant speed by using a piecewise strategy, which can significantly
reduce the computational burden. Monte Carlo simulation results and
an experimental result are presented to verify the effectiveness of the
algorithm advocated.
Abstract: In this paper a new method for increasing the speed of
SAGCM-APD is proposed. Utilizing carrier rate equations in
different regions of the structure, a circuit model for the structure is
obtained. In this research, in addition to frequency response, the
effect of added new charge layer on some transient parameters like
slew-rate, rising and falling times have been considered. Finally, by
trading-off among some physical parameters such as different layers
widths and droppings, a noticeable decrease in breakdown voltage
has been achieved. The results of simulation, illustrate some features
of proposed structure improvement in comparison with conventional
SAGCM-APD structures.
Abstract: This study analyzed environmental health risks and
people-s perceptions of risks related to waste management in poor
settlements of Abidjan, to develop integrated solutions for health and
well-being improvement. The trans-disciplinary approach used relied
on remote sensing, a geographic information system (GIS),
qualitative and quantitative methods such as interviews and a
household survey (n=1800). Mitigating strategies were then
developed using an integrated participatory stakeholder workshop.
Waste management deficiencies resulting in lack of drainage and
uncontrolled solid and liquid waste disposal in the poor settlements
lead to severe environmental health risks. Health problems were
caused by direct handling of waste, as well as through broader
exposure of the population. People in poor settlements had little
awareness of health risks related to waste management in their
community and a general lack of knowledge pertaining to sanitation
systems. This unfortunate combination was the key determinant
affecting the health and vulnerability. For example, an increased
prevalence of malaria (47.1%) and diarrhoea (19.2%) was observed
in the rainy season when compared to the dry season (32.3% and
14.3%). Concerted and adapted solutions that suited all the
stakeholders concerned were developed in a participatory workshop
to allow for improvement of health and well-being.
Abstract: The objective of this work is to investigate the
turbulent reacting flow in a three dimensional combustor with
emphasis on the effect of inlet swirl flow through a numerical
simulation. Flow field is analyzed using the SIMPLE method which is
known as stable as well as accurate in the combustion modeling, and
the finite volume method is adopted in solving the radiative transfer
equation. In this work, the thermal and flow characteristics in a three
dimensional combustor by changing parameters such as equivalence
ratio and inlet swirl angle have investigated. As the equivalence ratio
increases, which means that more fuel is supplied due to a larger inlet
fuel velocity, the flame temperature increases and the location of
maximum temperature has moved towards downstream. In the mean
while, the existence of inlet swirl velocity makes the fuel and
combustion air more completely mixed and burnt in short distance.
Therefore, the locations of the maximum reaction rate and temperature
were shifted to forward direction compared with the case of no swirl.
Abstract: The dramatic increasing of sea-freight container
transportations and the developing trends for using containers in the
multimodal handling systems through the sea, rail, road and land in
nowadays market cause general managers of container terminals to
face challenges such as increasing demand, competitive situation,
new investments and expansion of new activities and need to use new
methods to fulfil effective operations both along quayside and within
the yard. Among these issues, minimizing the turnaround time of
vessels is considered to be the first aim of every container port
system. Regarding the complex structure of container ports, this
paper presents a simulation model that calculates the number of
trucks needed in the Iranian Shahid Rajaee Container Port for
handling containers between the berth and the yard. In this research,
some important criteria such as vessel turnaround time, gantry crane
utilization and truck utilization have been considered. By analyzing
the results of the model, it has been shown that increasing the number
of trucks to 66 units has a significant effect on the performance
indices of the port and can increase the capacity of loading and
unloading up to 10.8%.
Abstract: In this paper, the authors take a look at advantages of
multiphase induction motors comparing them with three phase ones
and present the applications where six-phase induction motors are
used. They elaborate the mathematical model of six-phase induction
motor with two similar stator three phase winding, shifted by 30
degrees in space and three phase winding in rotor, in synchronous
reference frame for soft starting and scalar control. The authors
simulate and discuss results of speed and torque starting transients.
Abstract: Condition monitoring of electrical power equipment
has attracted considerable attention for many years. The aim of this
paper is to use Labview with Fuzzy Logic controller to build a
simulation system to diagnose transformer faults and monitor its
condition. The front panel of the system was designed using
LabVIEW to enable computer to act as customer-designed
instrument. The dissolved gas-in-oil analysis (DGA) method was
used as technique for oil type transformer diagnosis; meanwhile
terminal voltages and currents analysis method was used for dry type
transformer. Fuzzy Logic was used as expert system that assesses all
information keyed in at the front panel to diagnose and predict the
condition of the transformer. The outcome of the Fuzzy Logic
interpretation will be displayed at front panel of LabVIEW to show
the user the conditions of the transformer at any time.
Abstract: Permanent rivers are the main sources of renewable
water supply for the croplands under the irrigation and drainage
schemes. They are also the major source of sediment loads transport
into the storage reservoirs of the hydro-electrical dams, diversion
weirs and regulating dams. Sedimentation process results from soil
erosion which is related to poor watershed management and human
intervention ion in the hydraulic regime of the rivers. These could
change the hydraulic behavior and as such, leads to riverbed and river
bank scouring, the consequences of which would be sediment load
transport into the dams and therefore reducing the flow discharge in
water intakes. The present paper investigate sedimentation process
by varying the Manning coefficient "n" by using the SHARC
software along the watercourse in the Dez River. Results indicated
that the optimum "n" within that river range is 0.0315 at which
quantity minimum sediment loads are transported into the Eastern
intake. Comparison of the model results with those obtained by those
from the SSIIM software within the same river reach showed a very
close proximity between them. This suggests a relative accuracy with
which the model can simulate the hydraulic flow characteristics and
therefore its suitability as a powerful analytical tool for project
feasibility studies and project implementation.
Abstract: In this paper multivariable predictive PID controller has
been implemented on a multi-inputs multi-outputs control problem
i.e., quadruple tank system, in comparison with a simple multiloop
PI controller. One of the salient feature of this system is an
adjustable transmission zero which can be adjust to operate in both
minimum and non-minimum phase configuration, through the flow
distribution to upper and lower tanks in quadruple tank system.
Stability and performance analysis has also been carried out for this
highly interactive two input two output system, both in minimum
and non-minimum phases. Simulations of control system revealed
that better performance are obtained in predictive PID design.
Abstract: In current common research reports, salient regions
are usually defined as those regions that could present the main
meaningful or semantic contents. However, there are no uniform
saliency metrics that could describe the saliency of implicit image
regions. Most common metrics take those regions as salient regions,
which have many abrupt changes or some unpredictable
characteristics. But, this metric will fail to detect those salient useful
regions with flat textures. In fact, according to human semantic
perceptions, color and texture distinctions are the main characteristics
that could distinct different regions. Thus, we present a novel saliency
metric coupled with color and texture features, and its corresponding
salient region extraction methods. In order to evaluate the
corresponding saliency values of implicit regions in one image, three
main colors and multi-resolution Gabor features are respectively used
for color and texture features. For each region, its saliency value is
actually to evaluate the total sum of its Euclidean distances for other
regions in the color and texture spaces. A special synthesized image
and several practical images with main salient regions are used to
evaluate the performance of the proposed saliency metric and other
several common metrics, i.e., scale saliency, wavelet transform
modulus maxima point density, and important index based metrics.
Experiment results verified that the proposed saliency metric could
achieve more robust performance than those common saliency
metrics.
Abstract: The paper considers a single-server queue with fixedsize
batch Poisson arrivals and exponential service times, a model
that is useful for a buffer that accepts messages arriving as fixed size
batches of packets and releases them one packet at time. Transient
performance measures for queues have long been recognized as
being complementary to the steady-state analysis. The focus of the
paper is on the use of the functions that arise in the analysis of the
transient behaviour of the queuing system. The paper exploits
practical modelling to obtain a solution to the integral equation
encountered in the analysis. Results obtained indicate that under
heavy load conditions, there is significant disparity in the statistics
between the transient and steady state values.
Abstract: Complexity, as a theoretical background has made it
easier to understand and explain the features and dynamic behavior
of various complex systems. As the common theoretical background
has confirmed, borrowing the terminology for design from the
natural sciences has helped to control and understand urban
complexity. Phenomena like self-organization, evolution and
adaptation are appropriate to describe the formerly inaccessible
characteristics of the complex environment in unpredictable bottomup
systems. Increased computing capacity has been a key element in
capturing the chaotic nature of these systems.
A paradigm shift in urban planning and architectural design has
forced us to give up the illusion of total control in urban
environment, and consequently to seek for novel methods for
steering the development. New methods using dynamic modeling
have offered a real option for more thorough understanding of
complexity and urban processes. At best new approaches may renew
the design processes so that we get a better grip on the complex
world via more flexible processes, support urban environmental
diversity and respond to our needs beyond basic welfare by liberating
ourselves from the standardized minimalism.
A complex system and its features are as such beyond human
ethics. Self-organization or evolution is either good or bad. Their
mechanisms are by nature devoid of reason. They are common in
urban dynamics in both natural processes and gas. They are features
of a complex system, and they cannot be prevented. Yet their
dynamics can be studied and supported.
The paradigm of complexity and new design approaches has been
criticized for a lack of humanity and morality, but the ethical
implications of scientific or computational design processes have not
been much discussed. It is important to distinguish the (unexciting)
ethics of the theory and tools from the ethics of computer aided
processes based on ethical decisions. Urban planning and architecture
cannot be based on the survival of the fittest; however, the natural
dynamics of the system cannot be impeded on grounds of being
“non-human".
In this paper the ethical challenges of using the dynamic models
are contemplated in light of a few examples of new architecture and
dynamic urban models and literature. It is suggested that ethical
challenges in computational design processes could be reframed
under the concepts of responsibility and transparency.