Abstract: In this work, new experimental data for slugging
frequency in inclined gas-liquid flow are reported, and a new
correlation is proposed. Scale experiments were carried out using a
mixture of air and water in a 6 m long pipe. Two different pipe
diameters were used, namely, 38 and 67 mm. The data were taken
with capacitance type sensors at a data acquisition frequency of 200
Hz over an interval of 60 seconds. For the range of flow conditions
studied, the liquid superficial velocity is observed to influence the
frequency strongly. A comparison of the present data with
correlations available in the literature reveals a lack of agreement. A
new correlation for slug frequency has been proposed for the inclined
flow, which represents the main contribution of this work.
Abstract: In this paper we present a substantiation of a new
Laguerre-s type iterative method for solving of a nonlinear
polynomial equations systems with real coefficients. The problems of
its implementation, including relating to the structural choice of
initial approximations, were considered. Test examples demonstrate
the effectiveness of the method at the solving of many practical
problems solving.
Abstract: The error monitoring and processing system, EMPS is
the system located in the substantia nigra of the midbrain, basal
ganglia and cortex of the forebrain, and plays a leading role in error
detection and correction. The main components of EMPS are the
dopaminergic system and anterior cingulate cortex. Although, recent
studies show that alcohol disrupts the EMPS, the ways in which
alcohol affects this system are poorly understood. Based on current
literature data, here we suggest a hypothesis of alcohol-related
glucose-dependent system of error monitoring and processing, which
holds that the disruption of the EMPS is related to the competency of
glucose homeostasis regulation, which in turn may determine the
dopamine level as a major component of EMPS. Alcohol may
indirectly disrupt the EMPS by affecting dopamine level through
disorders in blood glucose homeostasis regulation.
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: At present, dictionary attack has been the basic tool for
recovering key passwords. In order to avoid dictionary attack, users
purposely choose another character strings as passwords. According to
statistics, about 14% of users choose keys on a keyboard (Kkey, for
short) as passwords. This paper develops a framework system to attack
the password chosen from Kkeys and analyzes its efficiency. Within
this system, we build up keyboard rules using the adjacent and parallel
relationship among Kkeys and then use these Kkey rules to generate
password databases by depth-first search method. According to the
experiment results, we find the key space of databases derived from
these Kkey rules that could be far smaller than the password databases
generated within brute-force attack, thus effectively narrowing down
the scope of attack research. Taking one general Kkey rule, the
combinations in all printable characters (94 types) with Kkey adjacent
and parallel relationship, as an example, the derived key space is about
240 smaller than those in brute-force attack. In addition, we
demonstrate the method's practicality and value by successfully
cracking the access password to UNIX and PC using the password
databases created
Abstract: The development of wireless communication technologies has changed our living style in global level. After the international success of mobile telephony standards, the location and time independent voice connection has become a default method in daily telecommunications. As for today, highly advanced multimedia messaging plays a key role in value added service handling. Along with evolving data services, the need for more complex applications can be seen, including the mobile usage of broadcast technologies. Here performance of a system design for terrestrial multimedia content is examined with emphasis on mobile reception. This review paper has accommodated the understanding of physical layer role and the flavour of terrestrial channel effects on the terrestrial multimedia transmission using OFDM keeping DVB-H as benchmark standard.
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: 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 aim of the study was to investigate the possible
use of commercial Computational Fluid Dynamics (CFD) software in
the design process of a domestic gas boiler. Because of the limited
computational resources some simplifications had to be made in
order to contribute to the design in a reasonable timescale.
The porous media model was used in order to simulate the
influence of the pressure drop characteristic of particular elements of
a heat transfer system on the water-flow distribution in the system.
Further, a combination of CFD analyses and spread sheet
calculations was used in order to solve the flow distribution problem.
Abstract: the data of Taiwanese 8th grader in the 4th cycle of
Trends in International Mathematics and Science Study (TIMSS) are
analyzed to examine the influence of the science teachers- preference
in experimental teaching on the relationships between the affective
variables ( the perceived usefulness of science, ease of using science
and science learning interest) and the academic achievement in science.
After dealing with the missing data, 3711 students and 145 science
teacher-s data were analyzed through a Hierarchical Linear Modeling
technique. The major objective of this study was to determine the role
of the experimental teaching moderates the relationship between
perceived usefulness and achievement.
Abstract: Due to the growing dynamic and complexity within
the market environment production enterprises in particular are faced
with new logistic challenges. Moreover, it is here in this dynamic
environment that the Logistic Operating Curve Theory also reaches
its limits as a method for describing the correlations between the
logistic objectives. In order to convert this theory into a method for
dynamically monitoring productions this paper will introduce
methods for reliably and quickly identifying structural changes
relevant to logistics.
Abstract: Exposure to ambient air pollution has been linked to a
number of health outcomes, starting from modest transient changes in
the respiratory tract and impaired pulmonary function, continuing to
restrict activity/reduce performance and to the increase emergency
rooms visits, hospital admissions or mortality. The increase of
allergenic symptoms has been associated with air contaminants such
as ozone, particulate matter, fungal spores and pollen.
Considering the potential relevance of crossed effects of nonbiological
pollutants and airborne pollens and fungal spores on
allergy worsening, the aim of this work was to evaluate the influence
of non-biological pollutants (O3 and PM10) and meteorological
parameters on the concentrations of pollen and fungal spores using
multiple linear regressions.
The data considered in this study were collected in Oporto which
is the second largest Portuguese city, located in the North. Daily
mean of O3, PM10, pollen and fungal spore concentrations,
temperature, relative humidity, precipitation, wind velocity, pollen
and fungal spore concentrations, for 2003, 2004 and 2005 were
considered. Results showed that the 90th percentile of the adjusted
coefficient of determination, P90 (R2aj), of the multiple regressions
varied from 0.613 to 0.916 for pollen and from 0.275 to 0.512 for
fungal spores. O3 and PM10 showed to have some influence on the
biological pollutants. Among the meteorological parameters
analysed, temperature was the one that most influenced the pollen
and fungal spores airborne concentrations. Relative humidity also
showed to have some influence on the fungal spore dispersion.
Nevertheless, the models for each pollen and fungal spore were
different depending on the analysed period, which means that the
correlations identified as statistically significant can not be, even so,
consistent enough.
Abstract: This study had two goals. First, it investigated marital
interaction variables as predictors of treatment outcome in panic
disorder with agoraphobia (PDA) in sixty-five couples with one
spouse suffering from PDA. Second, it analyzed the impact of PDA
improvement, following therapy, on marital interaction patterns of
both spouses. The partners were observed during a problem-solving
task, before and after treatment. Negative behaviors at the outset of
therapy, both in the PDA and the NPDA partners, predicted less
improvement at post-test. It also appears that improvement in some
PDA symptoms following therapy is linked to increase in the
dominant behavior of the NPDA spouse and to an improvement in
terms of his intrusiveness.
Abstract: The growth of open networks created the interest to
commercialise it. The establishment of an electronic business
mechanism must be accompanied by a digital – electronic payment
system to transfer the value of transactions. Financial organizations
are requested to offer a secure e-payment synthesis with equivalent
level of security served in conventional paper-based payment
transactions. PKI, which is functioning as a chain of trust in security
architecture, can enable security services of cryptography to epayments,
in order to take advantage of the wider base either of
customer or of trading partners and the reduction of cost transaction
achieved by the use of Internet channels. The paper addresses the
possibilities and the implementation suggestions of PKI in relevance
to electronic payments by suggesting a framework that should be
followed.
Abstract: In this paper, we use Generalized Hamiltonian systems approach to synchronize a modified sixth-order Chua's circuit, which generates hyperchaotic dynamics. Synchronization is obtained between the master and slave dynamics with the slave being given by an observer. We apply this approach to transmit private information (analog and binary), while the encoding remains potentially secure.
Abstract: The Zung self-depression scale and Beck Anxiety Inventory were used both to study the depression and anxiety levels of Armenian Crohn’s disease patients, and to reveal the relation between emotional status and placebo effect of these patients. On the other hand, the blood cell analyses and gut bacteria investigations were used to assess the placebo effect on ESR, and haemoglobin-s and leukocyte-s levels as well as gut commensal E. coli quantities of these patients. Despite of registered high levels of depression and anxiety, the high placebo effect on psychoemotional status for investigated patients during the investigations was described. On the other hand, no positive effect of placebo on measurements of ESP and hemoglobin-s levels of Crohn’s disease patients was revealed. The importance of use of psychotherapies for optimal outcomes during treatments of Crohn’s disease is discussed.
Abstract: In this paper, we prove that if X is regular strongly screenable DC-like (C-scattered), then X ×Y is strongly screenable for every strongly screenable space Y . We also show that the product i∈ω Yi is strongly screenable if every Yi is a regular strongly screenable DC-like space. Finally, we present that the strongly screenableness are poorly behaved with its Tychonoff products.
Abstract: In practice, we often come across situations where it is
necessary to make decisions based on incomplete or uncertain data.
In control systems it may be due to the unknown exact mathematical
model, or its excessive complexity (e.g. nonlinearity) when it is
necessary to simplify it, respectively, to solve it using a rule base. In
the case of databases, searching data we compare a similarity
measure with of the requirements of the selection with stored data,
where both the select query and the data itself may contain vague
terms, for example in the form of linguistic qualifiers. In this paper,
we focus on the processing of uncertain data in databases and
demonstrate it on the example multi-criteria decision making in the
selection of variants, specified by higher number of technical
parameters.
Abstract: This paper addresses a novel technique for placement of distributed generation (DG) in electric power systems. A GA based approach for sizing and placement of DG keeping in view of system power loss minimization in different loading conditions is explained. Minimal system power loss is obtained under voltage and line loading constraints. Proposed strategy is applied to power distribution systems and its effectiveness is verified through simulation results on 16, 37-bus and 75-bus test systems.
Abstract: We present a method for the selection of students
in interdisciplinary studies based on the hybrid averaging
operator. We assume that the available information given in
the problem is uncertain so it is necessary to use interval
numbers. Therefore, we suggest a new type of hybrid
aggregation called uncertain induced generalized hybrid
averaging (UIGHA) operator. It is an aggregation operator
that considers the weighted average (WA) and the ordered
weighted averaging (OWA) operator in the same formulation.
Therefore, we are able to consider the degree of optimism of
the decision maker and grades of importance in the same
approach. By using interval numbers, we are able to represent
the information considering the best and worst possible results
so the decision maker gets a more complete view of the
decision problem. We develop an illustrative example of the
proposed scheme in the selection of students in
interdisciplinary studies. We see that with the use of the
UIGHA operator we get a more complete representation of the
selection problem. Then, the decision maker is able to
consider a wide range of alternatives depending on his
interests. We also show other potential applications that could
be used by using the UIGHA operator in educational problems
about selection of different types of resources such as
students, professors, etc.