Abstract: Learning using labeled and unlabelled data has
received considerable amount of attention in the machine learning
community due its potential in reducing the need for expensive
labeled data. In this work we present a new method for combining
labeled and unlabeled data based on classifier ensembles. The model
we propose assumes each classifier in the ensemble observes the
input using different set of features. Classifiers are initially trained
using some labeled samples. The trained classifiers learn further
through labeling the unknown patterns using a teaching signals that is
generated using the decision of the classifier ensemble, i.e. the
classifiers self-supervise each other. Experiments on a set of object
images are presented. Our experiments investigate different classifier
models, different fusing techniques, different training sizes and
different input features. Experimental results reveal that the proposed
self-supervised ensemble learning approach reduces classification
error over the single classifier and the traditional ensemble classifier
approachs.
Abstract: Cities expansion, urban travels increase, the
technology development, the automobile price cheapen, and the
families' income ascending cause the considerable increase in
automobile numbers of the city. This fact has led to the traffic
creation and the automobile parking site shortage in the city. Also in
Esfahan metropolis, the parking lots shortage has been the great
problem of this town; in addition, in designing and constructing of
the parking sites the traditional methods are utilized which do not
have a reasonable and optimized usage of the valuable urban lands. In
this article, by introducing the prefabricate mechanized parking
system which is inexpensive, simple and quick, and occupies very
small space, therefore provides the high content of parking site for
the cities, we can eliminate the parking space shortage difficulty of
the cities. The achieved results of this research represent that an
optimized utilization of the existent urban spaces for parking site
construction has not been accomplished. By employing the new
parking site technologies such as mechanization categorized parking
sites and the capacity prefabricate mechanized of each parking space
have become 8 multiples; in this case, the valuable urban lands can
be used in an optimized way.
Abstract: This paper predicts the effect of the user-s hand-hold
position on the Total Isotropic Sensitivity (TIS) of GSM900/1800
mobile phone antennas of realistic in-use conditions, where different
semi-realistic mobile phone models, i.e., candy bar and clamshell, as
well as different antenna types, i.e., external and internal, are
simulated using a FDTD-based platform. A semi-realistic hand model
consisting of three tissues and the SAM head are used in simulations.
The results show a considerable impact on TIS of the adopted mobile
phone models owing to the user-s hand presence at different
positions, where a maximum level of TIS is obtained while grasping
the upper part of the mobile phone against head. Maximum TIS
levels are recorded in talk position for mobile phones with external
antenna and maximum differences in TIS levels due to the hand-hold
alteration are recorded for clamshell-type phones.
Abstract: In general, reports are a form of representing data in
such way that user gets the information he needs. They can be built in
various ways, from the simplest (“select from") to the most complex
ones (results derived from different sources/tables with complex
formulas applied). Furthermore, rules of calculations could be written
as a program hard code or built in the database to be used by dynamic
code. This paper will introduce two types of reports, defined in the
DB structure. The main goal is to manage calculations in optimal
way, keeping maintenance of reports as simple and smooth as
possible.
Abstract: Economic models are complex dynamic systems with a lot of uncertainties and fuzzy data. Conventional modeling approaches using well known methods and techniques cannot provide realistic and satisfactory answers to today-s challenging economic problems. Qualitative modeling using fuzzy logic and intelligent system theories can be used to model macroeconomic models. Fuzzy Cognitive maps (FCM) is a new method been used to model the dynamic behavior of complex systems. For the first time FCMs and the Mamdani Model of Intelligent control is used to model macroeconomic models. This new model is referred as the Mamdani Rule-Based Fuzzy Cognitive Map (MBFCM) and provides the academic and research community with a new promising integrated advanced computational model. A new economic model is developed for a qualitative approach to Macroeconomic modeling. Fuzzy Controllers for such models are designed. Simulation results for an economic scenario are provided and extensively discussed
Abstract: An exploration in the competency of the optical
multilevel Mapping Multiplexing Technique (MMT) system in
tolerating to the impact of nonlinearities as Self Phase Modulation
(SPM) during the presence of dispersion compensation methods. The
existence of high energy pulses stimulates deterioration in the chirp
compression process attained by SPM which introduces an upper
power boundary limit. An evaluation of the post and asymmetric prepost
fiber compensation methods have been deployed on the MMT
system compared with others of the same bit rate modulation formats.
The MMT 40 Gb/s post compensation system has 1.4 dB
enhancements to the 40 Gb/s 4-Arysystem and less than 3.9 dB
penalty compared to the 40 Gb/s OOK-RZsystem. However, the
optimized Pre-Post asymmetric compensation has an enhancement of
4.6 dB compared to the Post compensation MMT configuration for a
30% pre compensation dispersion.
Abstract: The direct synthesis process of dimethyl ether (DME)
from syngas in slurry reactors is considered to be promising because
of its advantages in caloric transfer. In this paper, the influences of
operating conditions (temperature, pressure and weight hourly space
velocity) on the conversion of CO, selectivity of DME and methanol
were studied in a stirred autoclave over Cu-Zn-Al-Zr slurry catalyst,
which is far more suitable to liquid phase dimethyl ether synthesis
process than bifunctional catalyst commercially. A Langmuir-
Hinshelwood mechanism type global kinetics model for liquid phase
DME direct synthesis based on methanol synthesis models and a
methanol dehydration model has been investigated by fitting our
experimental data. The model parameters were estimated with
MATLAB program based on general Genetic Algorithms and
Levenberg-Marquardt method, which is suitably fitting experimental
data and its reliability was verified by statistical test and residual
error analysis.
Abstract: Recently, the Spherical Motion Models (SMM-s) have been introduced [1]. These new models have been developed for 3D local landmark-base Autonomous Navigation (AN). This paper is revealing new arguments and experimental results to support the SMM-s characteristics. The accuracy and the robustness in performing a specific task are the main concerns of the new investigations. To analyze their performances of the SMM-s, the most powerful tools of estimation theory, the extended Kalman filter (EKF) and unscented Kalman filter (UKF), which give the best estimations in noisy environments, have been employed. The Monte Carlo validation implementations used to test the stability and robustness of the models have been employed as well.
Abstract: Liners are made to protect the groundwater table from
the infiltration of leachate which normally carries different kinds of
toxic materials from landfills. Although these liners are engineered to
last for long period of time; unfortunately these liners fail; therefore,
toxic materials pass to groundwater. This paper focuses on the
changes of the hydraulic conductivity of a sand-bentonite liner due to
the infiltration of biofuel and ethanol fuel. Series of laboratory tests
were conducted in 20-cm-high PVC columns. Several compositions
of sand-bentonite liners were tested: 95% sand: 5% bentonite; 90%
sand: 10% bentonite; and 100% sand (passed mesh #40). The
columns were subjected to extreme pressures of 40 kPa, and 100 kPa
to evaluate the transport of alternative fuels (biofuel and ethanol
fuel). For comparative studies, similar tests were carried out using
water. Results showed that hydraulic conductivity increased due to
the infiltration of alternative fuels through the liners. Accordingly,
the increase in the hydraulic conductivity showed significant
dependency on the type of liner mixture and the characteristics of the
liquid. The hydraulic conductivity of a liner (subjected to biofuel
infiltration) consisting of 5% bentonite: 95% sand under pressure of
40 kPa and 100 kPa had increased by one fold. In addition, the
hydraulic conductivity of a liner consisting of 10% bentonite: 90%
sand under pressure of 40 kPa and 100 kPa and infiltrated by biofuel
had increased by three folds. On the other hand, the results obtained
by water infiltration under 40 kPa showed lower hydraulic
conductivities of 1.50×10-5 and 1.37×10-9 cm/s for 5% bentonite:
95% sand, and 10% bentonite: 90% sand, respectively. Similarly,
under 100 kPa, the hydraulic conductivities were 2.30×10-5 and
1.90×10-9 cm/s for 5% bentonite: 95% sand, and 10% bentonite: 90%
sand, respectively.
Abstract: German electricity European options on futures using
Lévy processes for the underlying asset are examined. Implied
volatility evolution, under each of the considered models, is
discussed after calibrating for the Merton jump diffusion (MJD),
variance gamma (VG), normal inverse Gaussian (NIG), Carr, Geman,
Madan and Yor (CGMY) and the Black and Scholes (B&S) model.
Implied volatility is examined for the entire sample period, revealing
some curious features about market evolution, where data fitting
performances of the five models are compared. It is shown that
variance gamma processes provide relatively better results and that
implied volatility shows significant differences through time, having
increasingly evolved. Volatility changes for changed uncertainty, or
else, increasing futures prices and there is evidence for the need to
account for seasonality when modelling both electricity spot/futures
prices and volatility.
Abstract: The fast growth in complexity coupled with requests for shorter development periods for embedded systems are bringing demands towards a more effective, i.e. higher-abstract, design process for hardaware/software integrated design. In Software Engineering area, Model Driven Architecture (MDA) and Executable UML (xUML) has been accepted to bring further improvement in software design. This paper constructs MDA and xUML stepwise transformations from an abstract specification model to a more concrete implementation model using the refactoring technique for hardaware/software integrated design. This approach provides clear and structured models which enables quick exploration and synthesis, and early stage verification.
Abstract: Severe heart failure is a common problem that has a significant effect on health expenditures in industrialized countries; moreover it reduces patient-s quality of life. However, current research usually focuses either on detailed modeling of the heart or on detailed modeling of the cardiovascular system. Thus, this paper aims to present a sophisticated model of the heart enhanced with an extensive model of the cardiovascular system. Special interest is on the pressure and flow values close to the heart since these values are critical to accurately diagnose causes of heart failure. The model is implemented in Dymola an object-oriented, physical modeling language. Results achieved with the novel model show overall feasibility of the approach. Moreover, results are illustrated and compared to other models. The novel model shows significant improvements.
Abstract: The Time-Domain Boundary Element Method (TDBEM)
is a well known numerical technique that handles quite
properly dynamic analyses considering infinite dimension media.
However, when these analyses are also related to nonlinear behavior,
very complex numerical procedures arise considering the TD-BEM,
which may turn its application prohibitive. In order to avoid this
drawback and model nonlinear infinite media, the present work
couples two BEM formulations, aiming to achieve the best of two
worlds. In this context, the regions expected to behave nonlinearly
are discretized by the Domain Boundary Element Method (D-BEM),
which has a simpler mathematical formulation but is unable to deal
with infinite domain analyses; the TD-BEM is employed as in the
sense of an effective non-reflexive boundary. An iterative procedure
is considered for the coupling of the TD-BEM and D-BEM, which is
based on a relaxed renew of the variables at the common interfaces.
Elastoplastic models are focused and different time-steps are allowed
to be considered by each BEM formulation in the coupled analysis.
Abstract: This paper presents a cold flow simulation study of a small gas turbine combustor performed using laboratory scale test rig. The main objective of this investigation is to obtain physical insight of the main vortex, responsible for the efficient mixing of fuel and air. Such models are necessary for predictions and optimization of real gas turbine combustors. Air swirler can control the combustor performance by assisting in the fuel-air mixing process and by producing recirculation region which can act as flame holders and influences residence time. Thus, proper selection of a swirler is needed to enhance combustor performance and to reduce NOx emissions. Three different axial air swirlers were used based on their vane angles i.e., 30°, 45°, and 60°. Three-dimensional, viscous, turbulent, isothermal flow characteristics of the combustor model operating at room temperature were simulated via Reynolds- Averaged Navier-Stokes (RANS) code. The model geometry has been created using solid model, and the meshing has been done using GAMBIT preprocessing package. Finally, the solution and analysis were carried out in a FLUENT solver. This serves to demonstrate the capability of the code for design and analysis of real combustor. The effects of swirlers and mass flow rate were examined. Details of the complex flow structure such as vortices and recirculation zones were obtained by the simulation model. The computational model predicts a major recirculation zone in the central region immediately downstream of the fuel nozzle and a second recirculation zone in the upstream corner of the combustion chamber. It is also shown that swirler angles changes have significant effects on the combustor flowfield as well as pressure losses.
Abstract: The image segmentation method described in this
paper has been developed as a pre-processing stage to be used in
methodologies and tools for video/image indexing and retrieval by
content. This method solves the problem of whole objects extraction
from background and it produces images of single complete objects
from videos or photos. The extracted images are used for calculating
the object visual features necessary for both indexing and retrieval
processes.
The segmentation algorithm is based on the cooperation among an
optical flow evaluation method, edge detection and region growing
procedures. The optical flow estimator belongs to the class of
differential methods. It permits to detect motions ranging from a
fraction of a pixel to a few pixels per frame, achieving good results in
presence of noise without the need of a filtering pre-processing stage
and includes a specialised model for moving object detection.
The first task of the presented method exploits the cues from
motion analysis for moving areas detection. Objects and background
are then refined using respectively edge detection and seeded region
growing procedures. All the tasks are iteratively performed until
objects and background are completely resolved.
The method has been applied to a variety of indoor and outdoor
scenes where objects of different type and shape are represented on
variously textured background.
Abstract: one of the significant factors for improving the
accuracy of Land Surface Temperature (LST) retrieval is the correct
understanding of the directional anisotropy for thermal radiance. In
this paper, the multiple scattering effect between heterogeneous
non-isothermal surfaces is described rigorously according to the
concept of configuration factor, based on which a directional thermal
radiance model is built, and the directional radiant character for urban
canopy is analyzed. The model is applied to a simple urban canopy
with row structure to simulate the change of Directional Brightness
Temperature (DBT). The results show that the DBT is aggrandized
because of the multiple scattering effects, whereas the change range of
DBT is smoothed. The temperature difference, spatial distribution,
emissivity of the components can all lead to the change of DBT. The
“hot spot" phenomenon occurs when the proportion of high
temperature component in the vision field came to a head. On the other
hand, the “cool spot" phenomena occur when low temperature
proportion came to the head. The “spot" effect disappears only when
the proportion of every component keeps invariability. The model
built in this paper can be used for the study of directional effect on
emissivity, the LST retrieval over urban areas and the adjacency effect
of thermal remote sensing pixels.
Abstract: Three-dimensional geometric models have been used
to present architectural and engineering works, showing their final
configuration. When the clarification of a detail or the constitution of
a construction step in needed, these models are not appropriate. They
do not allow the observation of the construction progress of a
building. Models that could present dynamically changes of the
building geometry are a good support to the elaboration of projects.
Techniques of geometric modeling and virtual reality were used to
obtain models that could visually simulate the construction activity.
The applications explain the construction work of a cavity wall and a
bridge. These models allow the visualization of the physical
progression of the work following a planned construction sequence,
the observation of details of the form of every component of the
works and support the study of the type and method of operation of
the equipment applied in the construction. These models presented
distinct advantage as educational aids in first-degree courses in Civil
Engineering. The use of Virtual Reality techniques in the
development of educational applications brings new perspectives to
the teaching of subjects related to the field of civil construction.
Abstract: The design of a landing gear is one of the fundamental aspects of aircraft design. The need for a light weight, high strength, and stiffness characteristics coupled with techno economic feasibility are a key to the acceptability of any landing gear construction. In this paper, an approach for analyzing two different designed landing gears for an unmanned aircraft vehicle (UAV) using advanced CAE techniques will be applied. Different landing conditions have been considered for both models. The maximum principle stresses for each model along with the factor of safety are calculated for every loading condition. A conclusion is drawing about better geometry.
Abstract: In any trust model, the two information sources that a peer relies on to predict trustworthiness of another peer are direct experience as well as reputation. These two vital components evolve over time. Trust evolution is an important issue, where the objective is to observe a sequence of past values of a trust parameter and determine the future estimates. Unfortunately, trust evolution algorithms received little attention and the proposed algorithms in the literature do not comply with the conditions and the nature of trust. This paper contributes to this important problem in the following ways: (a) presents an algorithm that manages and models trust evolution in a P2P environment, (b) devises new mechanisms for effectively maintaining trust values based on the conditions that influence trust evolution , and (c) introduces a new methodology for incorporating trust-nurture incentives into the trust evolution algorithm. Simulation experiments are carried out to evaluate our trust evolution algorithm.
Abstract: This paper presents the comparative study of coded
data methods for finding the benefit of concealing the natural data
which is the mercantile secret. Influential parameters of the number
of replicates (rep), treatment effects (τ) and standard deviation (σ)
against the efficiency of each transformation method are investigated.
The experimental data are generated via computer simulations under
the specified condition of the process with the completely
randomized design (CRD). Three ways of data transformation consist
of Box-Cox, arcsine and logit methods. The difference values of F
statistic between coded data and natural data (Fc-Fn) and hypothesis
testing results were determined. The experimental results indicate
that the Box-Cox results are significantly different from natural data
in cases of smaller levels of replicates and seem to be improper when
the parameter of minus lambda has been assigned. On the other hand,
arcsine and logit transformations are more robust and obviously,
provide more precise numerical results. In addition, the alternate
ways to select the lambda in the power transformation are also
offered to achieve much more appropriate outcomes.