Abstract: This paper explores steady-state characteristics of
grid-connected doubly fed induction motor (DFIM) in case of unity
power factor operation. Based on the synchronized mathematical
model, analytic determination of the control laws is presented and
illustrated by various figures to understand the effect of the applied
rotor voltage on the speed and the active power. On other hand,
unlike previous works where the stator resistance was neglected, in
this work, stator resistance is included such that the equations can be
applied to small wind turbine generators which are becoming more
popular. Finally the work is crowned by integration of the studied
induction generator in a wind system where an open loop control is
proposed confers a remarkable simplicity of implementation
compared to the known methods.
Abstract: Supply Chain Management (SCM) is the integration
between manufacturer, transporter and customer in order to form one
seamless chain that allows smooth flow of raw materials, information
and products throughout the entire network that help in minimizing
all related efforts and costs. The main objective of this paper is to
develop a model that can accept a specified number of spare-parts
within the supply chain, simulating its inventory operations
throughout all stages in order to minimize the inventory holding
costs, base-stock, safety-stock, and to find the optimum quantity of
inventory levels, thereby suggesting a way forward to adapt some
factors of Just-In-Time to minimizing the inventory costs throughout
the entire supply chain. The model has been developed using Micro-
Soft Excel & Visual Basic in order to study inventory allocations in
any network of the supply chain. The application and reproducibility
of this model were tested by comparing the actual system that was
implemented in the case study with the results of the developed
model. The findings showed that the total inventory costs of the
developed model are about 50% less than the actual costs of the
inventory items within the case study.
Abstract: Lanthanide-doped upconversion nanoparticles which can convert near-infrared lights to visible lights have attracted growing interest because of their great potentials in fluorescence imaging. Upconversion fluorescence imaging technique with excitation in the near-infrared (NIR) region has been used for imaging of biological cells and tissues. However, improving the detection sensitivity and decreasing the absorption and scattering in biological tissues are as yet unresolved problems. In this present study, a novel NIR-reflected multispectral imaging system was developed for upconversion fluorescent imaging in small animals. Based on this system, we have obtained the high contrast images without the autofluorescence when biocompatible UCPs were injected near the body surface or deeply into the tissue. Furthermore, we have extracted respective spectra of the upconversion fluorescence and relatively quantify the fluorescence intensity with the multispectral analysis. To our knowledge, this is the first time to analyze and quantify the upconversion fluorescence in the small animal imaging.
Abstract: This paper provides an introduction into the evolution
of information and communication technology and illustrates its
usage in the work domain. The paper is sub-divided into two parts.
The first part gives an overview over the different phases of
information processing in the work domain. It starts by charting the
past and present usage of computers in work environments and shows
current technological trends, which are likely to influence future
business applications. The second part starts by briefly describing,
how the usage of computers changed business processes in the past,
and presents first Ambient Intelligence applications based on
identification and localization information, which are already used in
the production and retail sector. Based on current systems and
prototype applications, the paper gives an outlook of how Ambient
Intelligence technologies could change business processes in the
future.
Abstract: This paper compares Hilditch, Rosenfeld, Zhang-
Suen, dan Nagendraprasad Wang Gupta (NWG) thinning algorithms
for Javanese character image recognition. Thinning is an effective
process when the focus in not on the size of the pattern, but rather on
the relative position of the strokes in the pattern. The research
analyzes the thinning of 60 Javanese characters.
Time-wise, Zhang-Suen algorithm gives the best results with the
average process time being 0.00455188 seconds. But if we look at
the percentage of pixels that meet one-pixel thickness, Rosenfelt
algorithm gives the best results, with a 99.98% success rate. From the
number of pixels that are erased, NWG algorithm gives the best
results with the average number of pixels erased being 84.12%. It can
be concluded that the Hilditch algorithm performs least successfully
compared to the other three algorithms.
Abstract: Nowadays the control of stator voltage at a constant frequency is one of the traditional and low expense methods in order to control the speed of induction motors near its nominal speed. The torque of induction motor is a nonlinear function of the firing angle, phase angle and speed. In this paper the speed control of induction motor regarding various load torque and under different conditions will be investigated based on a fuzzy controller with inverse training.
Abstract: Lactic acid alone and its combined application with
nisin were evaluated for reducing population of naturally occurring
microorganisms on chilled shrimp. Fresh shrimps were dipped in 0,
1.0% and 2.0% (v/v) lactic acid alone and their combined application
with 0.04 (g/L/kg) nisin solution for 10 min. Total plate counts of
aerobic bacteria (TPCs), Psychrotrophic counts, population of
Pseudomonas spp., H2S producing bacteria and Lactic acid bacteria
(LAB) on shrimps were determined during storage at 4 °C. The
results indicated that total plate counts were 2.91 and 2.63 log CFU/g
higher on untreated shrimps after 7 and 14 days of storage,
respectively, than on shrimps treated with 2.0% lactic acid combined
with 0.04 (g/L/kg) nisin. Both concentrations of lactic acid indicated
significant reduction on Pseudomonas counts during storage, while
2.0% lactic acid combined with nisin indicated the highest reduction.
In addition, H2S producing bacteria were more sensitive to high
concentration of lactic acid combined with nisin during storage.
Abstract: This paper presents a hybrid approach for solving nqueen problem by combination of PSO and SA. PSO is a population based heuristic method that sometimes traps in local maximum. To solve this problem we can use SA. Although SA suffer from many iterations and long time convergence for solving some problems, By good adjusting initial parameters such as temperature and the length of temperature stages SA guarantees convergence. In this article we use discrete PSO (due to nature of n-queen problem) to achieve a good local maximum. Then we use SA to escape from local maximum. The experimental results show that our hybrid method in comparison of SA method converges to result faster, especially for high dimensions n-queen problems.
Abstract: In this paper we present a combined
hashing/watermarking method for image authentication. A robust
image hash, invariant to legitimate modifications, but fragile to
illegitimate modifications is generated from the local image
characteristics. To increase security of the system the watermark is
generated using the image hash as a key. Quantized Index
Modulation of DCT coefficients is used for watermark embedding.
Watermark detection is performed without use of the original image.
Experimental results demonstrate the effectiveness of the presented
method in terms of robustness and fragility.
Abstract: The identification and elimination of bad
measurements is one of the basic functions of a robust state estimator
as bad data have the effect of corrupting the results of state
estimation according to the popular weighted least squares method.
However this is a difficult problem to handle especially when dealing
with multiple errors from the interactive conforming type. In this
paper, a self adaptive genetic based algorithm is proposed. The
algorithm utilizes the results of the classical linearized normal
residuals approach to tune the genetic operators thus instead of
making a randomized search throughout the whole search space it is
more likely to be a directed search thus the optimum solution is
obtained at very early stages(maximum of 5 generations). The
algorithm utilizes the accumulating databases of already computed
cases to reduce the computational burden to minimum. Tests are
conducted with reference to the standard IEEE test systems. Test
results are very promising.
Abstract: Protection and proper management of archaeological heritage are an essential process of studying and interpreting the generations present and future. Protecting the archaeological heritage is based upon multidiscipline professional collaboration. This study aims to gather data by different sources (Photogrammetry and Geographic Information System (GIS)) integrated for the purpose of documenting one the of significant archeological sites (Ahl-Alkahf, Jordan). 3D modeling deals with the actual image of the features, shapes and texture to represent reality as realistically as possible by using texture. The 3D coordinates that result of the photogrammetric adjustment procedures are used to create 3D-models of the study area. Adding Textures to the 3D-models surfaces gives a 'real world' appearance to the displayed models. GIS system combined all data, including boundary maps, indicating the location of archeological sites, transportation layer, digital elevation model and orthoimages. For realistic representation of the study area, 3D - GIS model prepared, where efficient generation, management and visualization of such special data can be achieved.
Abstract: As mobile ad hoc networks (MANET) have different
characteristics from wired networks and even from standard wireless
networks, there are new challenges related to security issues that
need to be addressed. Due to its unique features such as open nature,
lack of infrastructure and central management, node mobility and
change of dynamic topology, prevention methods from attacks on
them are not enough. Therefore intrusion detection is one of the
possible ways in recognizing a possible attack before the system
could be penetrated. All in all, techniques for intrusion detection in
old wireless networks are not suitable for MANET. In this paper, we
classify the architecture for Intrusion detection systems that have so
far been introduced for MANETs, and then existing intrusion
detection techniques in MANET presented and compared. We then
indicate important future research directions.
Abstract: fifteen cultivars of Strawberries (Queen Eliza, Sequia,
Paros, Mcdonance, Selva, Chandler, Mrak, Ten beauty, Aliso, Pajero,
Kordestan, Camarosa, Blackmore, Gaviota and Fresno) were
investigated in 2011, under hydroponic system condition. Yield and
fruit Firmness was determinate. Chemical analyses of soluble solids
content (SSC), titratable acidity (TA), ascorbic acid (AA) and pH
were done. 4 cultivars (Aliso, Selva, Paros and Gaviota) yielded more
than 250 g/plant, while cultivar Black more, Fresno and Kordestan
produced less than 100g/plant. The amounts of fruit firmness
indicated that 'Camarosa' fruit was firmer than others cultivars.
Cultivar 'Fresno' had the highest pH (3.27). Ttitratable acidity varied
from 1.03g/l00g for cultivar 'Sequia' and 'Gaviota' to 1.48g/l00g for
cultivar 'Chandler'. Fresno, Kordestan, Aliso and Chandler showed
the highest soluble solid concentration. Ascorbic acid averaged for
most cultivars between 30.26 and 79.73 mg/100gf.w. Present results
showed that different cultivars of strawberry contain highly variable
in fruit quality.
Abstract: Nuclear energy sources have been widely used in the
past decades in order to power spacecraft subsystems. Nevertheless,
their use has attracted controversy because of the risk of harmful
material released into the atmosphere if an accident were to occur
during the launch phase of the mission, leading to the general
adoption of photovoltaic systems.
As compared to solar cells, wind turbines have a great advantage
on Mars, as they can continuously produce power both during dust
storms and at night-time: this paper focuses on the potential of a wind
energy conversion system (WECS) considering the atmospheric
conditions on Mars. Wind potential on Martian surface has been
estimated, as well as the average energy requirements of a Martian
probe or surface rover. Finally, the expected daily energy output of
the WECS has been computed on the basis of both the swept area of
the rotor and the equivalent wind speed at the landing site.
Abstract: This work presents an approach for the measurement
of mutual inductance on near field inductive coupling. The mutual
inductance between inductive circuits allows the simulation of energy
transfer from reader to tag, that can be used in RFID and powerless
implantable devices. It also allows one to predict the maximum
voltage in the tag of the radio-frequency system.
Abstract: Policies that support entrepreneurship are keys to the
generation of new business. In Brazil, seed capital, installation of
technology parks, programs and zero interest financing, economic
subsidy as Program First Innovative Company (PRIME) are
examples of incentive policies. For the implementation of PRIME, in
particular the Brazilian Innovation Agency (FINEP) decentralized
operationalization so that business incubators could select innovative
projects. This paper analyzes the program PRIME Business Incubator
Center of the State of Sergipe (CISE) after calculating the mean and
standard deviation of the grades obtained by companies in the factors
of innovation, market potential, financial return economic, market
strategy and staff and application of the Mann-Whitney test.
Abstract: This paper discusses the novel graphical approach for
stability analysis of multi induction motor drive controlled by a single
inverter. Stability issue arises in parallel connected induction motors
under unbalanced load conditions. The two powerful globally
accepted modeling and simulation software packages such as
MATLAB and LabVIEW are selected to perform the stability
analysis. The stability investigation is performed for different load
conditions and difference in stator and rotor resistances among the
two motors. It is very simple and effective than the techniques
presented to obtain the stability of the parallel connected induction
motor drive under unbalanced load conditions. Approximate transfer
functions are considered to model the induction motors, load
dynamics, speed controllers and inverter. Simulink library tools are
utilized to model the entire drive scheme in MATLAB. Stability
study is discussed in LabVIEW using control design and simulation
toolkits. Simulation results are illustrated for various running
conditions to demonstrate the effectiveness of the transfer function
method.
Abstract: The main purpose of this research is the calculation of implicit prices of the environmental level of air quality in the city of Moscow on the basis of housing property prices. The database used contains records of approximately 20 thousand apartments and has been provided by a leading real estate agency operating in Russia. The explanatory variables include physical characteristics of the houses, environmental (industry emissions), neighbourhood sociodemographic and geographic data: GPS coordinates of each house. The hedonic regression results for ecological variables show «negative» prices while increasing the level of air contamination from such substances as carbon monoxide, nitrogen dioxide, sulphur dioxide, and particles (CO, NO2, SO2, TSP). The marginal willingness to pay for higher environmental quality is presented for linear and log-log models.
Abstract: The mechanical behavior of porous media is governed by the interaction between its solid skeleton and the fluid existing inside its pores. The interaction occurs through the interface of gains and fluid. The traditional analysis methods of porous media, based on the effective stress and Darcy's law, are unable to account for these interactions. For an accurate analysis, the porous media is represented in a fluid-filled porous solid on the basis of the Biot theory of wave propagation in poroelastic media. In Biot formulation, the equations of motion of the soil mixture are coupled with the global mass balance equations to describe the realistic behavior of porous media. Because of irregular geometry, the domain is generally treated as an assemblage of fmite elements. In this investigation, the numerical formulation for the field equations governing the dynamic response of fluid-saturated porous media is analyzed and employed for the study of transient wave motion. A finite element model is developed and implemented into a computer code called DYNAPM for dynamic analysis of porous media. The weighted residual method with 8-node elements is used for developing of a finite element model and the analysis is carried out in the time domain considering the dynamic excitation and gravity loading. Newmark time integration scheme is developed to solve the time-discretized equations which are an unconditionally stable implicit method Finally, some numerical examples are presented to show the accuracy and capability of developed model for a wide variety of behaviors of porous media.
Abstract: Traditional higher-education classrooms allow lecturers to observe students- behaviours and responses to a particular pedagogy during learning in a way that can influence changes to the pedagogical approach. Within current e-learning systems it is difficult to perform continuous analysis of the cohort-s behavioural tendency, making real-time pedagogical decisions difficult. This paper presents a Virtual Learning Process Environment (VLPE) based on the Business Process Management (BPM) conceptual framework. Within the VLPE, course designers can model various education pedagogies in the form of learning process workflows using an intuitive flow diagram interface. These diagrams are used to visually track the learning progresses of a cohort of students. This helps assess the effectiveness of the chosen pedagogy, providing the information required to improve course design. A case scenario of a cohort of students is presented and quantitative statistical analysis of their learning process performance is gathered and displayed in realtime using dashboards.