Abstract: In this paper, we investigate the low-lying energy
levels of the two-dimensional parabolic graphene quantum dots
(GQDs) in the presence of topological defects with long range
Coulomb impurity and subjected to an external uniform magnetic
field. The low-lying energy levels of the system are obtained within
the framework of the perturbation theory. We theoretically
demonstrate that a valley splitting can be controlled by geometrical
parameters of the graphene quantum dots and/or by tuning a uniform
magnetic field, as well as topological defects. It is found that, for
parabolic graphene dots, the valley splitting occurs due to the
introduction of spatial confinement. The corresponding splitting is
enhanced by the introduction of a uniform magnetic field and it
increases by increasing the angle of the cone in subcritical regime.
Abstract: Discussing the nexus between global health policy and local practices, this article addresses the recent Ebola outbreak as a role model for narrative co-constructions of epidemic risk. We will demonstrate in how far a theory-driven and methodologically rooted analysis of narrativity can help to improve mechanisms of prevention and intervention whenever epidemic risk needs to be addressed locally in order to contribute to global health. Analyzing the narrative transformation of Ebola, we will also address issues of transcultural problem-solving and of normative questions at stake. In this regard, we seek to contribute to a better understanding of a key question of global health and justice as well as to the underlying ethical questions. By highlighting and analyzing the functions of narratives, this paper provides a translational approach to refine our practices by which we address epidemic risk, be it on the national, the transnational or the global scale.
Abstract: Landfill leachates contain a number of persistent pollutants, including heavy metals. They have the ability to spread in ecosystems and accumulate in fish which most of them are classified as top-consumers of trophic chains. Fish are freely swimming organisms; but perhaps, due to their species-specific ecological and behavioral properties, they often prefer the most suitable biotopes and therefore, did not avoid harmful substances or environments. That is why it is necessary to evaluate the persistent pollutant dispersion in hydroecosystem using fish tissue metal concentration. In hydroecosystems of hybrid type (e.g. river-pond-river) the distance from the pollution source could be a perfect indicator of such a kind of metal distribution. The studies were carried out in the Kairiai landfill neighboring hybrid-type ecosystem which is located 5 km east of the Šiauliai City. Fish tissue (gills, liver, and muscle) metal concentration measurements were performed on two types of ecologically-different fishes according to their feeding characteristics: benthophagous (Gibel carp, roach) and predatory (Northern pike, perch). A number of mathematical models (linear, non-linear, using log and other transformations) have been applied in order to identify the most satisfactorily description of the interdependence between fish tissue metal concentration and the distance from the pollution source. However, the only one log-multiple regression model revealed the pattern that the distance from the pollution source is closely and positively correlated with metal concentration in all predatory fish tissues studied (gills, liver, and muscle).
Abstract: The increasing availability of information about earth
surface elevation (Digital Elevation Models DEM) generated from
different sources (remote sensing, Aerial Images, Lidar) poses the
question about how to integrate and make available to the most than
possible audience this huge amount of data. In order to exploit the potential of 3D elevation representation the
quality of data management plays a fundamental role. Due to the high
acquisition costs and the huge amount of generated data, highresolution
terrain surveys tend to be small or medium sized and
available on limited portion of earth. Here comes the need to merge
large-scale height maps that typically are made available for free at
worldwide level, with very specific high resolute datasets. One the
other hand, the third dimension increases the user experience and the
data representation quality, unlocking new possibilities in data
analysis for civil protection, real estate, urban planning, environment
monitoring, etc. The open-source 3D virtual globes, which are
trending topics in Geovisual Analytics, aim at improving the
visualization of geographical data provided by standard web services
or with proprietary formats. Typically, 3D Virtual globes like do not
offer an open-source tool that allows the generation of a terrain
elevation data structure starting from heterogeneous-resolution terrain
datasets. This paper describes a technological solution aimed to set
up a so-called “Terrain Builder”. This tool is able to merge
heterogeneous-resolution datasets, and to provide a multi-resolution
worldwide terrain services fully compatible with CesiumJS and
therefore accessible via web using traditional browser without any
additional plug-in.
Abstract: The process of human resources management in the structures of corporate groups demonstrates certain specificity, resulting from the division of decision-making and executive competencies, which occurs within these structures between a parent company and its subsidiaries. The subprocess of employee assessment is considered crucial, since it provides information for the implementation of personnel function. The empirical studies conducted in corporate groups, within which at least one company is located in Poland, confirmed the critical significance of employee assessment systems in the process of human resources management in corporate groups. Parent companies, most often, retain their decision-making authority within the framework of the discussed process and introduce uniform employee assessment and personnel controlling systems to subsidiary companies. However, the instruments for employee assessment applied in corporate groups do not present such specificity.
Abstract: With 40% of total world energy consumption,
building systems are developing into technically complex large
energy consumers suitable for application of sophisticated power
management approaches to largely increase the energy efficiency
and even make them active energy market participants. Centralized
control system of building heating and cooling managed by
economically-optimal model predictive control shows promising
results with estimated 30% of energy efficiency increase. The research
is focused on implementation of such a method on a case study
performed on two floors of our faculty building with corresponding
sensors wireless data acquisition, remote heating/cooling units and
central climate controller. Building walls are mathematically modeled
with corresponding material types, surface shapes and sizes. Models
are then exploited to predict thermal characteristics and changes in
different building zones. Exterior influences such as environmental
conditions and weather forecast, people behavior and comfort
demands are all taken into account for deriving price-optimal climate
control. Finally, a DC microgrid with photovoltaics, wind turbine,
supercapacitor, batteries and fuel cell stacks is added to make the
building a unit capable of active participation in a price-varying
energy market. Computational burden of applying model predictive
control on such a complex system is relaxed through a hierarchical
decomposition of the microgrid and climate control, where the
former is designed as higher hierarchical level with pre-calculated
price-optimal power flows control, and latter is designed as lower
level control responsible to ensure thermal comfort and exploit
the optimal supply conditions enabled by microgrid energy flows
management. Such an approach is expected to enable the inclusion
of more complex building subsystems into consideration in order to
further increase the energy efficiency.
Abstract: This paper describes a simple way to control the speed
of PMBLDC motor using Fuzzy logic control method. In the
conventional PI controller the performance of the motor system is
simulated and the speed is regulated by using PI controller. These
methods used to improve the performance of PMSM drives, but in
some cases at different operating conditions when the dynamics of
the system also vary over time and it can change the reference speed,
parameter variations and the load disturbance. The simulation is
powered with the MATLAB program to get a reliable and flexible
simulation. In order to highlight the effectiveness of the speed control
method the FLC method is used. The proposed method targeted in
achieving the improved dynamic performance and avoids the
variations of the motor drive. This drive has high accuracy, robust
operation from near zero to high speed. The effectiveness and
flexibility of the individual techniques of the speed control method
will be thoroughly discussed for merits and demerits and finally
verified through simulation and experimental results for comparative
analysis.
Abstract: Seeking and sharing knowledge on online forums
have made them popular in recent years. Although online forums are
valuable sources of information, due to variety of sources of
messages, retrieving reliable threads with high quality content is an
issue. Majority of the existing information retrieval systems ignore
the quality of retrieved documents, particularly, in the field of thread
retrieval. In this research, we present an approach that employs
various quality features in order to investigate the quality of retrieved
threads. Different aspects of content quality, including completeness,
comprehensiveness, and politeness, are assessed using these features,
which lead to finding not only textual, but also conceptual relevant
threads for a user query within a forum. To analyse the influence of
the features, we used an adopted version of voting model thread
search as a retrieval system. We equipped it with each feature solely
and also various combinations of features in turn during multiple
runs. The results show that incorporating the quality features
enhances the effectiveness of the utilised retrieval system
significantly.
Abstract: In this study, the potential benefits of playing action
video game among congenitally deaf and dumb subjects is reported in
terms of EEG ratio indices. The frontal and occipital lobes are
associated with development of motor skills, cognition, and visual
information processing and color recognition. The sixteen hours of
First-Person shooter action video game play resulted in the increase
of the ratios β/(α+θ) and β/θ in frontal and occipital lobes. This can
be attributed to the enhancement of certain aspect of cognition among
deaf and dumb subjects.
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: 21st century has transformed the labor market
landscape in a way of posing new and different demands on
university graduates as well as university lecturers, which means that
the knowledge and academic skills students acquire in the course of
their studies should be applicable and transferable from the higher
education context to their future professional careers. Given the
context of the Languages for Specific Purposes (LSP) classroom, the
teachers’ objective is not only to teach the language itself, but also to
prepare students to use that language as a medium to develop generic
skills and competences. These include media and information
literacy, critical and creative thinking, problem-solving and analytical
skills, effective written and oral communication, as well as
collaborative work and social skills, all of which are necessary to
make university graduates more competitive in everyday professional
environments. On the other hand, due to limitations of time and large
numbers of students in classes, the frequently topic-centered syllabus
of LSP courses places considerable focus on acquiring the subject
matter and specialist vocabulary instead of sufficient development of
skills and competences required by students’ prospective employers.
This paper intends to explore some of those issues as viewed both by
LSP lecturers and by business professionals in their respective
surveys. The surveys were conducted among more than 50 LSP
lecturers at higher education institutions in Croatia, more than 40 HR
professionals and more than 60 university graduates with degrees in
economics and/or business working in management positions in
mainly large and medium-sized companies in Croatia. Various elements of LSP course content have been taken into
consideration in this research, including reading and listening
comprehension of specialist texts, acquisition of specialist vocabulary
and grammatical structures, as well as presentation and negotiation
skills. The ability to hold meetings, conduct business correspondence,
write reports, academic texts, case studies and take part in debates
were also taken into consideration, as well as informal business
communication, business etiquette and core courses delivered in a
foreign language. The results of the surveys conducted among LSP
lecturers will be analyzed with reference to what extent those
elements are included in their courses and how consistently and
thoroughly they are evaluated according to their course requirements.
Their opinions will be compared to the results of the surveys
conducted among professionals from a range of industries in Croatia
so as to examine how useful and important they perceive the same
elements of the LSP course content in their working environments.
Such comparative analysis will thus show to what extent the syllabi
of LSP courses meet the demands of the employment market when it
comes to the students’ language skills and competences, as well as
transferable skills. Finally, the findings will also be compared to the
observations based on practical teaching experience and the relevant
sources that have been used in this research. In conclusion, the ideas and observations in this paper are merely
open-ended questions that do not have conclusive answers, but might
prompt LSP lecturers to re-evaluate the content and objectives of
their course syllabi.
Abstract: This paper presents the performance characteristics of
Darrieus-type vertical axis wind turbine (VAWT) with NACA airfoil
blades. The performance of Darrieus-type VAWT can be
characterized by torque and power. There are various parameters
affecting the performance such as chord length, helical angle, pitch
angle and rotor diameter. To estimate the optimum shape of Darrieustype
wind turbine in accordance with various design parameters, we
examined aerodynamic characteristics and separated flow occurring
in the vicinity of blade, interaction between flow and blade, and
torque and power characteristics derived from it. For flow analysis,
flow variations were investigated based on the unsteady RANS
(Reynolds-averaged Navier-Stokes) equation. Sliding mesh algorithm
was employed in order to consider rotational effect of blade. To
obtain more realistic results we conducted experiment and numerical
analysis at the same time for three-dimensional shape. In addition,
several parameters (chord length, rotor diameter, pitch angle, and
helical angle) were considered to find out optimum shape design and
characteristics of interaction with ambient flow. Since the NACA
airfoil used in this study showed significant changes in magnitude of
lift and drag depending on an angle of attack, the rotor with low drag,
long cord length and short diameter shows high power coefficient in
low tip speed ratio (TSR) range. On the contrary, in high TSR range,
drag becomes high. Hence, the short-chord and long-diameter rotor
produces high power coefficient. When a pitch angle at which airfoil
directs toward inside equals to -2° and helical angle equals to 0°,
Darrieus-type VAWT generates maximum power.
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: This paper discusses the applicability of the numerical model for a damage prediction method of the accidental hydrogen explosion occurring in a hydrogen facility. The numerical model was based on an unstructured finite volume method (FVM) code “NuFD/FrontFlowRed”. For simulating unsteady turbulent combustion of leaked hydrogen gas, a combination of Large Eddy Simulation (LES) and a combustion model were used. The combustion model was based on a two scalar flamelet approach, where a G-equation model and a conserved scalar model expressed a propagation of premixed flame surface and a diffusion combustion process, respectively. For validation of this numerical model, we have simulated the previous two types of hydrogen explosion tests. One is open-space explosion test, and the source was a prismatic 5.27 m3 volume with 30% of hydrogen-air mixture. A reinforced concrete wall was set 4 m away from the front surface of the source. The source was ignited at the bottom center by a spark. The other is vented enclosure explosion test, and the chamber was 4.6 m × 4.6 m × 3.0 m with a vent opening on one side. Vent area of 5.4 m2 was used. Test was performed with ignition at the center of the wall opposite the vent. Hydrogen-air mixtures with hydrogen concentrations close to 18% vol. were used in the tests. The results from the numerical simulations are compared with the previous experimental data for the accuracy of the numerical model, and we have verified that the simulated overpressures and flame time-of-arrival data were in good agreement with the results of the previous two explosion tests.
Abstract: The application of recycle waste tires into civil
engineering practices, namely asphalt paving mixtures and cementbased
materials has been gaining ground across the world. This
review summarizes and compares the recent achievements in the area
of plain rubberized concrete (PRC), in details. Different treatment
methods have been discussed to improve the performance of
rubberized Portland cement concrete. The review also includes the
effects of size and amount of tire rubbers on mechanical and
durability properties of PRC. The microstructure behaviour of the
rubberized concrete was detailed.
Abstract: Tourism can do a great deal of good in destinations,
whether it be by bringing economic benefits to local communities,
helping with conservation efforts or in placing a value on aspects of
cultural heritage. As responsive travelers, we must all try to do more
of the good and less of the negative. This is simply description of the
sustainable tourism. This paper aims to set some criteria of successful
sustainable tourism development and then through these criteria
analyzing the development of some resorts in Egypt known as
sustainable resorts. Hence, a comprehensive improvement of the
touristic areas is certainly needed to ensure a successful sustainable
tourism development radiated the sense of uniformity and coherence.
Egypt can benefit from these criteria to develop its resorts in order to
preserve and revitalize its unique natural character and achieve mixed
uses and tourism development.
Abstract: Data fusion technology can be the best way to extract
useful information from multiple sources of data. It has been widely
applied in various applications. This paper presents a data fusion
approach in multimedia data for event detection in twitter by using
Dempster-Shafer evidence theory. The methodology applies a mining
algorithm to detect the event. There are two types of data in the
fusion. The first is features extracted from text by using the bag-ofwords
method which is calculated using the term frequency-inverse
document frequency (TF-IDF). The second is the visual features
extracted by applying scale-invariant feature transform (SIFT). The
Dempster - Shafer theory of evidence is applied in order to fuse the
information from these two sources. Our experiments have indicated
that comparing to the approaches using individual data source, the
proposed data fusion approach can increase the prediction accuracy
for event detection. The experimental result showed that the proposed
method achieved a high accuracy of 0.97, comparing with 0.93 with
texts only, and 0.86 with images only.
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: Teaching methods include lectures, workshops and
tutorials for the presentation and discussion of ideas have become out
of date; were developed outside the discipline of architecture from
the college of engineering and do not satisfy the architectural
students’ needs and causes them many difficulties in integrating
structure into their design. In an attempt to improve structure
teaching methods, this paper focused upon proposing a supportive
teaching/learning tool using multi-media applications which seeks to
better meet the architecture student’s needs and capabilities and
improve the understanding and application of basic and intermediate
structural engineering and technology principles. Before introducing
the use of multi-media as a supportive teaching tool, a questionnaire
was distributed to third year students of a structural design course
who were selected as a sample to be surveyed forming a sample of 90
cases. The primary aim of the questionnaire was to identify the
students’ learning style and to investigate whether the selected
method of teaching could make the teaching and learning process
more efficient. Students’ reaction on the use of this method was
measured using three key elements indicating that this method is an
appropriate teaching method for the nature of the students and the
course as well.
Abstract: Ant algorithms are well-known metaheuristics which
have been widely used since two decades. In most of the literature,
an ant is a constructive heuristic able to build a solution from scratch.
However, other types of ant algorithms have recently emerged: the
discussion is thus not limited by the common framework of the
constructive ant algorithms. Generally, at each generation of an ant
algorithm, each ant builds a solution step by step by adding an
element to it. Each choice is based on the greedy force (also called the
visibility, the short term profit or the heuristic information) and the
trail system (central memory which collects historical information of
the search process). Usually, all the ants of the population have the
same characteristics and behaviors. In contrast in this paper, a new
type of ant metaheuristic is proposed, namely SMART (for Solution
Methods with Ants Running by Types). It relies on the use of different
population of ants, where each population has its own personality.