Abstract: An analysis of the air tightness level is performed on a representative sample of school classrooms in Southern Spain, which allows knowing the infiltration level of these classrooms, mainly through its envelope, which can affect both energy demand and occupant's thermal comfort. By using a pressurization/depressurization equipment (Blower-Door test), a characterization of 45 multipurpose classrooms have been performed in nine non-university educational institutions of the main climate zones of Southern Spain. In spite of having two doors and a high ratio between glass surface and outer surface, it is possible to see in these classrooms that there is an adequate level of airtightness, since all the n50 values obtained are lower than 9.0 ACH, with an average value around 7.0 ACH.
Abstract: Patient-specific models are instance-based learning
algorithms that take advantage of the particular features of the patient
case at hand to predict an outcome. We introduce two patient-specific
algorithms based on decision tree paradigm that use AUC as a
metric to select an attribute. We apply the patient specific algorithms
to predict outcomes in several datasets, including medical datasets.
Compared to the patient-specific decision path (PSDP) entropy-based
and CART methods, the AUC-based patient-specific decision path
models performed equivalently on area under the ROC curve (AUC).
Our results provide support for patient-specific methods being a
promising approach for making clinical predictions.
Abstract: Nowadays, education cannot be imagined without digital technologies. It broadens the horizons of teaching learning processes. Several universities are offering online courses. For evaluation purpose, e-examination systems are being widely adopted in academic environments. Multiple-choice tests are extremely popular. Moving away from traditional examinations to e-examination, Moodle as Learning Management Systems (LMS) is being used. Moodle logs every click that students make for attempting and navigational purposes in e-examination. Data mining has been applied in various domains including retail sales, bioinformatics. In recent years, there has been increasing interest in the use of data mining in e-learning environment. It has been applied to discover, extract, and evaluate parameters related to student’s learning performance. The combination of data mining and e-learning is still in its babyhood. Log data generated by the students during online examination can be used to discover knowledge with the help of data mining techniques. In web based applications, number of right and wrong answers of the test result is not sufficient to assess and evaluate the student’s performance. So, assessment techniques must be intelligent enough. If student cannot answer the question asked by the instructor then some easier question can be asked. Otherwise, more difficult question can be post on similar topic. To do so, it is necessary to identify difficulty level of the questions. Proposed work concentrate on the same issue. Data mining techniques in specific clustering is used in this work. This method decide difficulty levels of the question and categories them as tough, easy or moderate and later this will be served to the desire students based on their performance. Proposed experiment categories the question set and also group the students based on their performance in examination. This will help the instructor to guide the students more specifically. In short mined knowledge helps to support, guide, facilitate and enhance learning as a whole.
Abstract: Frequency transformation with Pascal matrix
equations is a method for transforming an electronic filter (analogue
or digital) into another filter. The technique is based on frequency
transformation in the s-domain, bilinear z-transform with pre-warping
frequency, inverse bilinear transformation and a very useful
application of the Pascal’s triangle that simplifies computing and
enables calculation by hand when transforming from one filter to
another. This paper will introduce two methods to transform a filter
into a digital filter: frequency transformation from the s-domain into
the z-domain; and frequency transformation in the z-domain. Further,
two Pascal matrix equations are derived: an analogue to digital filter
Pascal matrix equation and a digital to digital filter Pascal matrix
equation. These are used to design a desired digital filter from a given
filter.
Abstract: Many cluster based routing protocols have been
proposed in the field of wireless sensor networks, in which a group of
nodes are formed as clusters. A cluster head is selected from one
among those nodes based on residual energy, coverage area, number
of hops and that cluster-head will perform data gathering from
various sensor nodes and forwards aggregated data to the base station
or to a relay node (another cluster-head), which will forward the
packet along with its own data packet to the base station. Here a
Game Theory based Diligent Energy Utilization Algorithm (GTDEA)
for routing is proposed. In GTDEA, the cluster head selection is done
with the help of game theory, a decision making process, that selects
a cluster-head based on three parameters such as residual energy
(RE), Received Signal Strength Index (RSSI) and Packet Reception
Rate (PRR). Finding a feasible path to the destination with minimum
utilization of available energy improves the network lifetime and is
achieved by the proposed approach. In GTDEA, the packets are
forwarded to the base station using inter-cluster routing technique,
which will further forward it to the base station. Simulation results
reveal that GTDEA improves the network performance in terms of
throughput, lifetime, and power consumption.
Abstract: This paper describes an ab-initio design, development and calibration results of an Optical Sensor Ground Reaction Force Measurement Platform (OSGRFP) for gait and geriatric studies. The developed system employs an array of FBG sensors to measure the respective ground reaction forces from all three axes (X, Y and Z), which are perpendicular to each other. The novelty of this work is two folded. One is in its uniqueness to resolve the tri axial resultant forces during the stance in to the respective pure axis loads and the other is the applicability of inherently advantageous FBG sensors which are most suitable for biomechanical instrumentation. To validate the response of the FBG sensors installed in OSGRFP and to measure the cross sensitivity of the force applied in other directions, load sensors with indicators are used. Further in this work, relevant mathematical formulations are presented for extracting respective ground reaction forces from wavelength shifts/strain of FBG sensors on the OSGRFP. The result of this device has implications in understanding the foot function, identifying issues in gait cycle and measuring discrepancies between left and right foot. The device also provides a method to quantify and compare relative postural stability of different subjects under test, which has implications in post-surgical rehabilitation, geriatrics and optimizing training protocols for sports personnel.
Abstract: Torrefaction of biomass pellets is considered as a
useful pretreatment technology in order to convert them into a high
quality solid biofuel that is more suitable for pyrolysis, gasification,
combustion, and co-firing applications. In the course of torrefaction,
the temperature varies across the pellet, and therefore chemical
reactions proceed unevenly within the pellet. However, the
uniformity of the thermal distribution along the pellet is generally
assumed. The torrefaction process of a single cylindrical pellet is
modeled here, accounting for heat transfer coupled with chemical
kinetics. The drying sub-model was also introduced. The nonstationary
process of wood pellet decomposition is described by the
system of non-linear partial differential equations over the
temperature and mass. The model captures well the main features of
the experimental data.
Abstract: This paper proposes a method of learning topics for
broadcasting contents. There are two kinds of texts related to
broadcasting contents. One is a broadcasting script, which is a series of
texts including directions and dialogues. The other is blogposts, which
possesses relatively abstracted contents, stories, and diverse
information of broadcasting contents. Although two texts range over
similar broadcasting contents, words in blogposts and broadcasting
script are different. When unseen words appear, it needs a method to
reflect to existing topic. In this paper, we introduce a semantic
vocabulary expansion method to reflect unseen words. We expand
topics of the broadcasting script by incorporating the words in
blogposts. Each word in blogposts is added to the most semantically
correlated topics. We use word2vec to get the semantic correlation
between words in blogposts and topics of scripts. The vocabularies of
topics are updated and then posterior inference is performed to
rearrange the topics. In experiments, we verified that the proposed
method can discover more salient topics for broadcasting contents.
Abstract: Some of the main causes for degradation of polymeric materials are thermal aging, hydrolysis, oxidation or chemical degradation by acids, alkalis or water. The first part of this paper provides a brief summary of advances in technology, methods and specification of composite materials for relining as a rehabilitation technique for sewage systems. The second part summarizes an investigation on frequently used composite materials for relining in Sweden, the rubber filled epoxy composite and reinforced polyester composite when they were immersed in deionized water or in dry conditions, and elevated temperatures up to 80°C in the laboratory. The tests were conducted by visual inspection, microscopy, Dynamic Mechanical Analysis (DMA), Differential Scanning Calorimetry (DSC) as well as mechanical testing, three point bending and tensile testing.
Abstract: We have aimed to produce a self-cleaning transparent
polymer coating with polyurethane (PU) matrix as the latter is highly
solvent, chemical and weather resistant having good mechanical
properties. Nano-silica modified by 1H, 1H, 2H, 2Hperflurooctyltriethoxysilane
was incorporated into the PU matrix for
attaining self-cleaning ability through hydrophobicity. The
modification was confirmed by particle size analysis and scanning
electron microscopy (SEM). Thermo-gravimetric (TGA) studies were
carried to ascertain the grafting of silane onto the silica. Several
coating formulations were prepared by varying the silica loading
content and compared to a commercial equivalent. The effect of
dispersion and the morphology of the coated films were assessed by
SEM analysis. All coating standardized tests like solvent resistance,
adhesion, flexibility, acid, alkali, gloss etc. have been performed as
per ASTM standards. Water contact angle studies were conducted to
analyze the hydrophobic character of the coating. In addition, the
coatings were also subjected to salt spray and accelerated weather
testing to analyze the durability of the coating.
Abstract: Purpose: The key aim of the research was to identify
the secondary stressors experienced by businesses affected by single
or repeated flooding and to determine to what extent businesses were
affected by these stressors, along with any resulting impact on health.
Additionally the research aimed to establish the likelihood of
businesses being re-exposed to the secondary stressors through
assessing awareness of flood risk, implementation of property
protection measures and level of community resilience. Design/methodology/approach: The chosen research method
involved the distribution of a questionnaire survey to businesses
affected by either single or repeated flood events. The questionnaire
included the Impact of Event Scale (a 15-item self-report measure
which assesses subjective distress caused by traumatic events). Findings: 55 completed questionnaires were returned by flood
impacted businesses. 89% of the businesses had sustained internal
flooding, while 11% had experienced external flooding. The results
established that the key secondary stressors experienced by
businesses, in order of priority, were: flood damage, fear of
reoccurring flooding, prevention of access to the premise/closure,
loss of income, repair works, length of closure and insurance issues.
There was a lack of preparedness for potential future floods and
consequent vulnerability to the emergence of secondary stressors
among flood affected businesses, as flood resistance or flood
resilience measures had only been implemented by 11% and 13%
respectively. In relation to the psychological repercussions, the
Impact of Event scores suggested that potential prevalence of posttraumatic
stress disorder (PTSD) was noted among 8 out of 55
respondents (l5%). Originality/value: The results improve understanding of the
enduring repercussions of flood events on businesses, indicating that
not only residents may be susceptible to the detrimental health
impacts of flood events and single flood events may be just as likely
as reoccurring flooding to contribute to ongoing stress. Lack of
financial resources is a possible explanation for the lack of
implementation of property protection measures among businesses,
despite 49% experiencing flooding on multiple occasions. Therefore
it is recommended that policymakers should consider potential
sources of financial support or grants towards flood defences for
flood impacted businesses. Any form of assistance should be made
available to businesses at the earliest opportunity as there was no
significant association between the time of the last flood event and
the likelihood of experiencing PTSD symptoms.
Abstract: The purpose of the research described in this work is
to answer how to measure the rheologic (viscoelastic) properties
tendo–deformational characteristics of soft tissue. The method would
also resemble muscle palpation examination as it is known in clinical
practice. For this purpose, an instrument with the working name
“myotonometer” has been used. At present, there is lack of objective methods for assessing the
muscle tone by viscous and elastic properties of soft tissue. That is
why we decided to focus on creating or finding quantitative and
qualitative methodology capable to specify muscle tone.
Abstract: Teaching of mathematics to engineering students is an
open ended problem in education. The main goal of mathematics
learning for engineering students is the ability of applying a wide
range of mathematical techniques and skills in their engineering
classes and later in their professional work. Most of the
undergraduate engineering students and faculties feels that no efforts
and attempts are made to demonstrate the applicability of various
topics of mathematics that are taught thus making mathematics
unavoidable for some engineering faculty and their students. The lack
of understanding of concepts in engineering mathematics may hinder
the understanding of other concepts or even subjects. However, for
most undergraduate engineering students, mathematics is one of the
most difficult courses in their field of study. Most of the engineering students never understood mathematics or
they never liked it because it was too abstract for them and they could
never relate to it. A right balance of application and concept based
teaching can only fulfill the objectives of teaching mathematics to
engineering students. It will surely improve and enhance their
problem solving and creative thinking skills. In this paper, some practical (informal) ways of making
mathematics-teaching application based for the engineering students
is discussed. An attempt is made to understand the present state of
teaching mathematics in engineering colleges. The weaknesses and
strengths of the current teaching approach are elaborated. Some of
the causes of unpopularity of mathematics subject are analyzed and a
few pragmatic suggestions have been made. Faculty in mathematics
courses should spend more time discussing the applications as well as
the conceptual underpinnings rather than focus solely on strategies
and techniques to solve problems. They should also introduce more
‘word’ problems as these problems are commonly encountered in
engineering courses. Overspecialization in engineering education
should not occur at the expense of (or by diluting) mathematics and
basic sciences. The role of engineering education is to provide the
fundamental (basic) knowledge and to teach the students simple
methodology of self-learning and self-development. All these issues
would be better addressed if mathematics and engineering faculty
join hands together to plan and design the learning experiences for
the students who take their classes. When faculties stop competing
against each other and start competing against the situation, they will
perform better. Without creating any administrative hassles these
suggestions can be used by any young inexperienced faculty of
mathematics to inspire engineering students to learn engineering
mathematics effectively.
Abstract: In this current contribution, authors are dedicated to
investigate influence of the crystal lamellae orientation on
electromechanical behaviors of relaxor ferroelectric Poly
(vinylidene fluoride –trifluoroethylene -chlorotrifluoroethylene)
(P(VDF-TrFE-CTFE)) films by control of polymer microstructure,
aiming to picture the full map of structure-property relationship. In
order to define their crystal orientation films, terpolymer films were
fabricated by solution-casting, stretching and hot-pressing process.
Differential scanning calorimetry, impedance analyzer, and tensile
strength techniques were employed to characterize crystallographic
parameters, dielectric permittivity, and elastic Young’s modulus
respectively. In addition, large electrical induced out-of-plane
electrostrictive strain was obtained by cantilever beam mode.
Consequently, as-casted pristine films exhibited surprisingly high
electrostrictive strain 0.1774% due to considerably small value of
elastic Young’s modulus although relatively low dielectric
permittivity. Such reasons contributed to large mechanical elastic
energy density. Instead, due to 2 folds increase of elastic Young’s
modulus and less than 50% augmentation of dielectric constant, fullycrystallized
film showed weak electrostrictive behavior and
mechanical energy density as well. And subjected to mechanical
stretching process, Film C exhibited stronger dielectric constant and
out-performed electrostrictive strain over Film B because edge-on
crystal lamellae orientation induced by uniaxially mechanical stretch.
Hot-press films were compared in term of cooling rate. Rather large
electrostrictive strain of 0.2788% for hot-pressed Film D in
quenching process was observed although its dielectric permittivity
equivalent to that of pristine as-casted Film A, showing highest
mechanical elastic energy density value of 359.5 J/m3. In hot-press
cooling process, dielectric permittivity of Film E saw values at 48.8
concomitant with ca.100% increase of Young’s modulus. Films with
intermediate mechanical energy density were obtained.
Abstract: The crossover probability and mutation probability are the two important factors in genetic algorithm. The adaptive genetic algorithm can improve the convergence performance of genetic algorithm, in which the crossover probability and mutation probability are adaptively designed with the changes of fitness value. We apply adaptive genetic algorithm into a function optimization problem. The numerical experiment represents that adaptive genetic algorithm improves the convergence speed and avoids local convergence.
Abstract: Excessive vibration means increased wear, increased
repair efforts, bad product selection & quality and high energy
consumption. This may be sometimes experienced by cavitation or
suction/discharge recirculation which could occur only when net
positive suction head available NPSHA drops below the net positive
suction head required NPSHR. Cavitation can cause axial surging, if it
is excessive, will damage mechanical seals, bearings, possibly other
pump components frequently, and shorten the life of the impeller.
Efforts have been made to explain Suction Energy (SE), Specific
Speed (Ns), Suction Specific Speed (Nss), NPSHA, NPSHR & their
significance, possible reasons of cavitation /internal recirculation, its
diagnostics and remedial measures to arrest and prevent cavitation in
this paper. A case study is presented by the author highlighting that
the root cause of unwanted noise and vibration is due to cavitation,
caused by high specific speeds or inadequate net- positive suction
head available which results in damages to material surfaces of
impeller & suction bells and degradation of machine performance, its
capacity and efficiency too. Author strongly recommends revisiting
the technical specifications of CW pumps to provide sufficient NPSH
margin ratios >1.5, for future projects and Nss be limited to 8500 -
9000 for cavitation free operation.
Abstract: A combined heat and power (CHP) system is an efficient and clean way to generate power (electricity). Heat produced by the CHP system can be used for water and space heating. The CHP system which uses hydrogen as fuel produces zero carbon emission. Its’ efficiency can reach more than 80% whereas that of a traditional power station can only reach up to 50% because much of the thermal energy is wasted. The other advantages of CHP systems include that they can decentralize energy generation, improve energy security and sustainability, and significantly reduce the energy cost to the users. This paper presents the economic benefits of using a CHP system in the domestic environment. For this analysis, natural gas is considered as potential fuel as the hydrogen fuel cell based CHP systems are rarely used. UK government incentives for CHP systems are also considered as the added benefit. Results show that CHP requires a significant initial investment in returns it can reduce the annual energy bill significantly. Results show that an investment may be paid back in 7 years. After the back period, CHP can run for about 3 years as most of the CHP manufacturers provide 10 year warranty.
Abstract: In order to study the Mutual effect of genotype ×
environment for the percent of oil index in sunflower items, an
experiment was accomplished form complete random block designs
in four iteration and was four diverse researching station comprising
Esfahan, Birjand, Sari, and Karaj. Complex variance analysis showed
that there is an important diversity between the items under
investigation. The results relevant the coefficient variation of items
Azargol and Vidoc has respectively allocated the minimum
coefficient of variations. According to the results extrapolated from
Shokla stability variance, the Items Brocar, Allison and Fabiola, are
among the stable genotypes for oil percent respectively. In the biplot
GGE, the location under investigations divided in two superenvironments,
first one comprised of locations naming Esfahan,
Karaj, and Birjand, and second one were such a location as Sari. By
this point of view, in the first super-environment, the Item Fabiola
and in the second Almanzor item was among the best items and
crops.
Abstract: Nanofibers are defined as fibers with diameters less
than 100 nanometers. In this study, behaviours of activated carbon
nanofiber (ACNF), carbon nanofiber (CNF), polyacrylonitrile/ carbon
nanotube (PAN/CNT), polyvinyl alcohol/nanosilver (PVA/Ag) in
proton exchange membrane (PEM) fuel cells are investigated
experimentally. This material was used as gas diffusion layer (GDL)
in PEM fuel cells. In this study, the electrical conductivities of
nanofiber and nanofiber/nanoparticles have been studied to
understand their effects on PEM fuel cell performance. According to
the experimental results, the maximum electrical conductivity
performance of the fuel cell with nanofiber was found to be at
PVA/Ag (at UConn condition). The electrical conductivities of CNF,
ACNF, PAN/CNT are lower for PEM. The resistance of cell with
PVA/Ag is lower than the resistance of cell with PAN/CNT, ACNF,
CNF.
Abstract: Biodiesel is widely investigated to solve the twin
problem of depletion of fossil fuel and environmental degradation.
The main objective of the present work is to compare performance,
emissions, and combustion characteristics of biodiesel derived from
cotton seed oil in a diesel engine with the baseline results of
petrodiesel fuel. Tests have been conducted on a single cylinder, four
stroke CIDI diesel engine with a speed of 1500 rpm and a fixed
compression ratio of 17.5 at different load conditions. The
performance parameters evaluated include brake thermal efficiency,
brake specific fuel consumption, brake power, indicated mean
effective pressure, mechanical efficiency, and exhaust gas
temperature. Regarding combustion study, cylinder pressure, rate of
pressure rise, net heat release rate, cumulative heat release, mean gas
temperature, mass fraction burned, and fuel line pressure were
evaluated. The emission parameters such as carbon monoxide, carbon
dioxide, un-burnt hydrocarbon, oxides of nitrogen, and smoke
opacity were also measured by a smoke meter and an exhaust gas
analyzer and compared with baseline results. The brake thermal
efficiency of cotton seed oil methyl ester (CSOME) was lower than
that of petrodiesel and brake specific fuel consumption was found to
be higher. However, biodiesel resulted in the reduction of carbon
dioxide, un-burnt hydrocarbon, and smoke opacity at the expense of
nitrogen oxides. Carbon monoxide emissions for biodiesel was higher
at maximum output power. It has been found that the combustion
characteristics of cotton seed oil methyl ester closely followed those
of standard petrodiesel. The experimental results suggested that
biodiesel derived from cotton seed oil could be used as a good
substitute to petrodiesel fuel in a conventional diesel without any
modification.