Abstract: This paper presents a new method to design nonlinear
feedback linearization controller for PEMFCs (Polymer Electrolyte
Membrane Fuel Cells). A nonlinear controller is designed based on
nonlinear model to prolong the stack life of PEMFCs. Since it is
known that large deviations between hydrogen and oxygen partial
pressures can cause severe membrane damage in the fuel cell,
feedback linearization is applied to the PEMFC system so that the
deviation can be kept as small as possible during disturbances or load
variations. To obtain an accurate feedback linearization controller,
tuning the linear parameters are always important. So in proposed
study NSGA (Non-Dominated Sorting Genetic Algorithm)-II method
was used to tune the designed controller in aim to decrease the
controller tracking error. The simulation result showed that the
proposed method tuned the controller efficiently.
Abstract: This study was conducted to evaluate the manganese
removal from aqueous solution using Banana peels activated carbon
(BPAC). Batch experiments have been carried out to determine the
influence of parameters such as pH, biosorbent dose, initial metal ion
concentrations and contact times on the biosorption process. From
these investigations, a significant increase in percentage removal of
manganese 97.4% is observed at pH value 5.0, biosorbent dose 0.8 g,
initial concentration 20 ppm, temperature 25 ± 2°C, stirring rate 200
rpm and contact time 2h. The equilibrium concentration and the
adsorption capacity at equilibrium of the experimental results were
fitted to the Langmuir and Freundlich isotherm models; the Langmuir
isotherm was found to well represent the measured adsorption data
implying BPAC had heterogeneous surface. A raw groundwater
samples were collected from Baharmos groundwater treatment plant
network at Embaba and Manshiet Elkanater City/District-Giza,
Egypt, for treatment at the best conditions that reached at first phase
by BPAC. The treatment with BPAC could reduce iron and
manganese value of raw groundwater by 91.4% and 97.1%,
respectively and the effect of the treatment process on the
microbiological properties of groundwater sample showed decrease
of total bacterial count either at 22°C or at 37°C to 85.7% and 82.4%,
respectively. Also, BPAC was characterized using SEM and FTIR
spectroscopy.
Abstract: This paper presents a model predictive control (MPC)
of a utility interactive (UI) single phase inverter (SPI) for a
photovoltaic (PV) system at residential/distribution level. The
proposed model uses single-phase phase locked loop (PLL) to
synchronize SPI with the grid and performs MPC control in a dq
reference frame. SPI model consists of boost converter (BC),
maximum power point tracking (MPPT) control, and a full bridge
(FB) voltage source inverter (VSI). No PI regulators to tune and
carrier and modulating waves are required to produce switching
sequence. Instead, the operational model of VSI is used to synthesize
sinusoidal current and track the reference. Model is validated using a
three kW PV system at the input of UI-SPI in Matlab/Simulink.
Implementation and results demonstrate simplicity and accuracy, as
well as reliability of the model.
Abstract: The organizations of European and Czech critical
infrastructure have specific position, mission, characteristics and
behaviour in European Union and Czech state/business environments,
regarding specific requirements for regional and global security
environments. They must respect policy of national security and
global rules, requirements and standards in all their inherent and
outer processes of supply - customer chains and networks. A
controlling is generalized capability to have control over situational
policy. This paper aims and purposes are to introduce the controlling
as quite new necessary process attribute providing for critical
infrastructure is environment the capability and profit to achieve its
commitment regarding to the effectiveness of the quality
management system in meeting customer/ user requirements and also
the continual improvement of critical infrastructure organization’s
processes overall performance and efficiency, as well as its societal
security via continual planning improvement via DYVELOP
modelling.
Abstract: Well-designed composite steel and concrete structures
highlight the good material properties and lower the deficiencies of
steel and concrete, in particular they make use of high tensile strength
of steel and high stiffness of concrete. The most common composite
steel and concrete structure is a simply supported beam, which
concrete slab transferring the slab load to a beam is connected to the
steel cross-section. The aim of this paper is to find the most adequate
numerical model of a simply supported composite beam with the
cross-sectional and material parameters based on the results of a
processed parametric study and numerical analysis. The paper also
evaluates the suitability of using compact concrete with the
lightweight aggregates for composite steel and concrete beams. The
most adequate numerical model will be used in the resent future to
compare the results of laboratory tests.
Abstract: Load Forecasting plays a key role in making today's
and future's Smart Energy Grids sustainable and reliable. Accurate
power consumption prediction allows utilities to organize in advance
their resources or to execute Demand Response strategies more
effectively, which enables several features such as higher
sustainability, better quality of service, and affordable electricity
tariffs. It is easy yet effective to apply Load Forecasting at larger
geographic scale, i.e. Smart Micro Grids, wherein the lower available
grid flexibility makes accurate prediction more critical in Demand
Response applications. This paper analyses the application of
short-term load forecasting in a concrete scenario, proposed within the
EU-funded GreenCom project, which collect load data from single
loads and households belonging to a Smart Micro Grid. Three
short-term load forecasting techniques, i.e. linear regression, artificial
neural networks, and radial basis function network, are considered,
compared, and evaluated through absolute forecast errors and training
time. The influence of weather conditions in Load Forecasting is also
evaluated. A new definition of Gain is introduced in this paper, which
innovatively serves as an indicator of short-term prediction
capabilities of time spam consistency. Two models, 24- and
1-hour-ahead forecasting, are built to comprehensively compare these
three techniques.
Abstract: Diabetes is a growing health problem in worldwide.
Especially, the patients with Type 1 diabetes need strict glycemic
control because they have deficiency of insulin production. This
paper attempts to control blood glucose based on body mathematical
body model. The Bergman minimal mathematical model is used to
develop the nonlinear controller. A novel back-stepping based sliding
mode control (B-SMC) strategy is proposed as a solution that
guarantees practical tracking of a desired glucose concentration. In
order to show the performance of the proposed design, it is compared
with conventional linear and fuzzy controllers which have been done
in previous researches. The numerical simulation result shows the
advantages of sliding mode back stepping controller design to linear
and fuzzy controllers.
Abstract: The aim of the paper was to elaborate a novel calculator BasWilCalc, that allows to estimate the actual amount of biomass on the basket willow plantations. The proposed method is based on the results of field experiment conducted during years 2011-2013 on basket willow plantation in the south-western part of Poland. As input data the results of destructive measurements of the diameter, length and weight of willow stems and non-destructive biometric measurements of diameter in the middle of stems and their length during the growing season performed at weekly intervals were used. Performed analysis enabled to develop the algorithm which, due to the fact that energy plantations are of known and constant planting structure, allows to estimate the actual amount of willow basket biomass on the plantation with a given probability and accuracy specified by the model, based on the number of stems measured and the age of the plantation.
Abstract: The mathematical analysis on radiation obtained and
the development of the solar photovoltaic (PV) array groundwater
pumping is needed in the rural areas of Thohoyandou for sizing and
power performance subject to the climate conditions within the area.
A simple methodology approach is developed for the directed
coupled solar, controller and submersible ground water pump system.
The system consists of a PV array, pump controller and submerged
pump, battery backup and charger controller. For this reason, the
theoretical solar radiation is obtained for optimal predictions and
system performance in order to achieve different design and
operating parameters. Here the examination of the PV schematic
module in a Direct Current (DC) application is used for obtainable
maximum solar power energy for water pumping. In this paper, a
simple efficient photovoltaic water pumping system is presented with
its theoretical studies and mathematical modeling of photovoltaics
(PV) system.
Abstract: Calcium phosphate coating (CaP) has been employed
for protein delivery, but the typical direct protein adsorption on the
coating led to low incorporation content and fast release of the
protein from the coating. By using bovine serum albumin (BSA) as a
model protein, rapid biomimetic co-precipitation between calcium
phosphate and BSA was employed to control the distribution of BSA
within calcium phosphate coating during biomimetic formation on
titanium surface for only 6 h at 50oC in an accelerated calcium
phosphate solution. As a result, the amount of BSA incorporation and
release duration could be increased by using a rapid biomimetic coprecipitation
technique. Up to 43 fold increases in the BSA
incorporation content and the increase from 6 h to more than 360 h in
release duration compared to typical direct adsorption technique were
observed depending on the initial BSA concentration used during coprecipitation
(1, 10 and 100 μg.ml-1). From x-ray diffraction and
Fourier transform infrared spectroscopy studies, the coating
composition was not altered with the incorporation of BSA by this
rapid biomimetic co-precipitation and mainly comprised octacalcium
phosphate and hydroxyapatite. However, the microstructure of
calcium phosphate crystals changed from straight, plate-like units to
curved, plate-like units with increasing BSA content.
Abstract: The article presents the concept of an electromagnetic
circuit generator with permanent magnets mounted on the surface
rotor core designed for single phase work. Computation field-circuit
model was shown. The spectrum of time course of voltages in the
idle work was presented. The cross section with graphically
presentation of magnetic induction in particular parts of
electromagnetic circuits was presented. Distribution of magnetic
induction at the rated load point for each phase was shown. The time
course of voltages and currents for each phases for rated power were
displayed. An analysis of laboratory results and measurement of load
characteristics of the generator was discussed. The work deals with
three electromagnetic circuits of generators with permanent magnet
where output voltage characteristics versus rated power were
expressed.
Abstract: The success of any retail business is predisposed by its
swift response and its knack in understanding the constraints and the
requirements of customers. In this paper a conceptual design model
of an automated customer-friendly supermarket has been proposed.
In this model a 10-sided, space benefited, regular polygon shaped
gravity shelves have been designed for goods storage and effective
customer-specific algorithms have been built-in for quick automatic
delivery of the randomly listed goods. The algorithm is developed
with two main objectives, viz., delivery time and priority. For
meeting these objectives the randomly listed items are reorganized
according to the critical-path of the robotic arm specific to the
identified shop and its layout and the items are categorized according
to the demand, shape, size, similarity and nature of the product for an
efficient pick-up, packing and delivery process. We conjectured that
the proposed automated supermarket model reduces business
operating costs with much customer satisfaction warranting a winwin
situation.
Abstract: The assessment of the risk posed by a borrower to a
lender is one of the common problems that financial institutions have
to deal with. Consumers vying for a mortgage are generally
compared to each other by the use of a number called the Credit
Score, which is generated by applying a mathematical algorithm to
information in the applicant’s credit report. The higher the credit
score, the lower the risk posed by the candidate, and the better he is
to be taken on by the lender. The objective of the present work is to
use fuzzy logic and linguistic rules to create a model that generates
Credit Scores.
Abstract: Load carrying capacity of an oil lubricated two-axial
groove journal bearing is simulated by taking into account the
viscosity variations in lubricant due to the addition of TiO2
nanoparticles as lubricant additive. Shear viscosities of TiO2
nanoparticle dispersions in oil are measured for various nanoparticle
additive concentrations. The viscosity model derived from the
experimental viscosities is employed in a modified Reynolds
equation to obtain the pressure profiles and load carrying capacity of
two-axial groove journal bearing. Results reveal an increase in load
carrying capacity of bearings operating on nanoparticle dispersions as
compared to plain oil.
Abstract: Access control is one of the most challenging issues
facing information security. Access control is defined as, the ability to
permit or deny access to a particular computational resource or digital
information by an unauthorized user or subject. The concept of usage
control (UCON) has been introduced as a unified approach to capture a
number of extensions for access control models and systems. In
UCON, an access decision is determined by three factors:
authorizations, obligations and conditions. Attribute mutability and
decision continuity are two distinct characteristics introduced by
UCON for the first time. An observation of UCON components
indicates that, the components are predefined and static. In this paper,
we propose a new and flexible model of usage control for the creation
and elimination of some of these components; for example new
objects, subjects, attributes and integrate these with the original
UCON model. We also propose a model for concurrent usage
scenarios in UCON.
Abstract: The article demonstrates on a case study how it is
possible to identify MSD risk. It is based on a dissertation Risk
identification model of occupational diseases formation in relation to
the work activity that determines what risk can endanger workers who
are exposed to the specific risk factors. It is evaluated based on
statistical calculations. These risk factors are main cause of upperextremities
musculoskeletal disorders.
Abstract: This paper explores competencies that managers of
small firms in Ghana use to enhance operational flexibility towards
the attainment of higher productivity. This is because the requisite
competence required of such managers to be effective performers
continues to be a challenge. Data was collected from managers of
three hundred small firms using a standardized self-completion
questionnaire and analyzed using the Amos-based structural equation
model approach. Findings from factor and confirmatory factor
analyses showed that the only competence exhibited by managers
toward effective performance is realistic practices evident at the
workplace. It is concluded that a manager’s self-confidence and
involvement in areas that he/she is good at, and his/her possession of
skills that enables performance at high capacity are indications of the
manger’s effectiveness. The study outcome provides a knowledge
base helpful to policy-makers, especially in Ghana, in determining
the requisite managerial competences required by small firm
managers for effective performance.
Abstract: The aim of this work is to present a theoretical analysis of a 2D ultrasound transducer comprised of crossed arrays of metal strips placed on both sides of thin piezoelectric layer (a). Such a structure is capable of electronic beam-steering of generated wavebeam both in elevation and azimuth. In this paper a semi-analytical model of the considered transducer is developed. It is based on generalization of the well-known BIS-expansion method. Specifically, applying the electrostatic approximation, the electric field components on the surface of the layer are expanded into fast converging series of double periodic spatial harmonics with corresponding amplitudes represented by the properly chosen Legendre polynomials. The problem is reduced to numerical solving of certain system of linear equations for unknown expansion coefficients.
Abstract: In this study, the evaluation of thermal stability of the
micrometer-sized silica particle reinforced epoxy composite was
carried out through the measurement of thermal expansion coefficient
and Young’s modulus of the specimens. For all the specimens in this
study from the baseline to those containing 50 wt% silica filler, the
thermal expansion coefficients and the Young’s moduli were
gradually decreased down to 20% and increased up to 41%,
respectively. The experimental results were compared with fillervolume-
based simple empirical relations. The experimental results of
thermal expansion coefficients correspond with those of Thomas’s
model which is modified from the rule of mixture. However, the
measured result for Young’s modulus tends to be increased slightly.
The differences in increments of the moduli between experimental and
numerical model data are quite large.
Abstract: In addition to the production, which is already
frequently optimized, improving the distribution logistics also opens
up tremendous potential for increasing an enterprise’s
competitiveness. Here too though, numerous interactions need to be
taken into account, enterprises thus need to be able to identify and
weigh between different potentials for economically efficient
optimizations. In order to be able to assess potentials, enterprises
require a suitable method. This paper first briefly presents the need
for this research before introducing the procedure that will be used to
develop an appropriate method that not only considers interactions
but is also quickly and easily implemented.