Abstract: In order to verify the performance of lunar lander
structure, landing-impact test is urgently needed. And the test
equipment is necessary for the test. The functions and the key points of
the equipment are presented to satisfy the requirements of the test, and
the design scheme is proposed. The composition, the major function
and the critical parts’ design of the equipment are introduced. By the
load test of releasing device and single-beam hoist, and the
compatibility test of landing-impact testing system, the rationality and
reliability of the equipment is proved.
Abstract: The goal of this article is the analysis of knowledge
transfer at the regional level of the Czech Republic. We show how
goals of enterprises´ innovative activities are related to the rate of
cooperation with different actors within regional innovative systems
as well as in other world regions. The results show that the most
important partners of enterprises are their suppliers and clients in
most Czech regions. The cooperation rate of enterprises correlates
significantly mainly with enterprises´ efforts to enter new markets
and reduce labour costs per unit output. The meaning of this
cooperation decreases with the increase of partner’s distance.
Regarding the type of a cooperating partner, cooperation within an
enterprise had to do with the increase of market share and decrease of
labour costs. On the other hand, cooperation with clients had to do
with efforts to replace outdated products or processes or enter new
markets. We can pay less attention to the cooperation with
government authorities and organizations. The reasons for
marginalization of this cooperation should be submitted to further
detailed investigation.
Abstract: Urban greenery remains the bastion of urban
landscape and a key to sustainable development due to its integral
connections to the general health and wellbeing of urban residents.
However, in an era of rapid urbanisation, recent studies indicate that
urban greenery, especially ecologically sensitive areas, in many
African cities is becoming increasingly depleted. Given the scale and
rate of natural and anthropogenic change, effective management of
urban greenery as the ultimate goal of restoring depleting urban
landscapes is urgent. This review advocates for an urban resilience
model to managing urban greenery.
Abstract: Different strategies and tools are available at the oil
and gas industry for detecting and analyzing tension and possible
fractures in borehole walls. Most of these techniques are based on
manual observation of the captured borehole images. While this
strategy may be possible and convenient with small images and few
data, it may become difficult and suitable to errors when big
databases of images must be treated. While the patterns may differ
among the image area, depending on many characteristics (drilling
strategy, rock components, rock strength, etc.). In this work we
propose the inclusion of data-mining classification strategies in order
to create a knowledge database of the segmented curves. These
classifiers allow that, after some time using and manually pointing
parts of borehole images that correspond to tension regions and
breakout areas, the system will indicate and suggest automatically
new candidate regions, with higher accuracy. We suggest the use of
different classifiers methods, in order to achieve different knowledge
dataset configurations.
Abstract: The main aim of this research was to investigate the
perspectives of English language teachers and learners on the effect
of test techniques on reading comprehension, test performance and
assessment. The research has also aimed at finding the differences
between teacher and learner perspectives, specifying the test
techniques which have the highest effect, investigating the other
factors affecting reading comprehension, and comparing the results
with the similar studies. In order to achieve these objectives,
perspectives and findings of different researchers were reviewed, two
different questionnaires were prepared to collect data for the
perspectives of teachers and learners, the questionnaires were applied
to 26 learners and 8 teachers from the University of Batna (Algeria),
and quantitative and qualitative data analysis of the results were
done. The results and analysis of the results show that different test
techniques affect reading comprehension, test performance and
assessment at different percentages rates.
Abstract: The use of IT equipment has become a part of every
day. However, each device that is part of cyberspace should be
secured against unauthorized use. It is very important to know the
basics of these security devices, but also the basics of safe conduct
their owners. This information should be part of every curriculum
computer science education in primary and secondary schools.
Therefore, the work focuses on the education of pupils in primary and
secondary schools on the Internet. Analysis of the current state
describes approaches to the education of pupils in security issues on
the Internet. The paper presents a questionnaire-based survey which
was carried out in the Czech Republic, whose task was to ascertain
the level of opinion pupils in primary and secondary schools on the
issue of communication in social networks. The research showed that
awareness of socio-pathological phenomena on the Internet
environment is very low. Based on the results it was proposed
appropriate ways of teaching to this issue and its inclusion a proposal
of curriculum for primary and secondary schools.
Abstract: This paper is concerning the issues of behaviour of
lightweight expanded clay aggregates concrete exposed to high
temperature. Lightweight aggregates from expanded clay are
produced by firing of row material up to temperature 1050°C.
Lightweight aggregates have suitable properties in terms of volume
stability, when exposed to temperatures up to 1050°C, which could
indicate their suitability for construction applications with higher risk
of fire. The test samples were exposed to heat by using the standard
temperature-time curve ISO 834. Negative changes in resulting
mechanical properties, such as compressive strength, tensile strength,
and flexural strength were evaluated. Also visual evaluation of the
specimen was performed. On specimen exposed to excessive heat, an
explosive spalling could be observed, due to evaporation of
considerable amount of unbounded water from the inner structure of
the concrete.
Abstract: Characterization of the engineering behavior of
unsaturated soil is dependent on the soil-water characteristic curve
(SWCC), a graphical representation of the relationship between water
content or degree of saturation and soil suction. A reasonable
description of the SWCC is thus important for the accurate prediction
of unsaturated soil parameters. The measurement procedures for
determining the SWCC, however, are difficult, expensive, and timeconsuming.
During the past few decades, researchers have laid a
major focus on developing empirical equations for predicting the
SWCC, with a large number of empirical models suggested. One of
the most crucial questions is how precisely existing equations can
represent the SWCC. As different models have different ranges of
capability, it is essential to evaluate the precision of the SWCC
models used for each particular soil type for better SWCC estimation.
It is expected that better estimation of SWCC would be achieved via
a thorough statistical analysis of its distribution within a particular
soil class. With this in view, a statistical analysis was conducted in
order to evaluate the reliability of the SWCC prediction models
against laboratory measurement. Optimization techniques were used
to obtain the best-fit of the model parameters in four forms of SWCC
equation, using laboratory data for relatively coarse-textured (i.e.,
sandy) soil. The four most prominent SWCCs were evaluated and
computed for each sample. The result shows that the Brooks and
Corey model is the most consistent in describing the SWCC for sand
soil type. The Brooks and Corey model prediction also exhibit
compatibility with samples ranging from low to high soil water
content in which subjected to the samples that evaluated in this study.
Abstract: Immunomodulators are substances that alter immune
system via dynamic regulation of messenger molecules. It can be
divided into immunostimulant and immunosuppressant. It can help to
increase immunity of people with a low immune system, and also can
help to normalize an overactive immune system. Aim of this study is
to investigate the effects of in vitro exposure to low and high doses of
several immunomodulators which include caffeine, kaloba and
quercetin on antigen-stimulated whole blood culture cytokine
production. Whole blood samples were taken from 5 healthy males
(age: 32 ± 12 years; weight: 75.7 ± 6.1 kg; BMI: 24.3 ± 1.5 kg/m2)
following an overnight fast with no vigorous activity during the
preceding 24 h. The whole blood was then stimulated with 50 μl of
100 x diluted Pediacel vaccine and low or high dose of
immunomodulators in the culture plate. After 20 h incubation (5%
CO2, 37°C), it was analysed using the Evidence Investigator to
determine the production of cytokines including IL-2, IL-4, IL-10,
IFN-γ, and IL-1α. Caffeine and quercetin showed a tendency towards
decrease cytokine production as the doses were increased. On the
other hand, an upward trend was evident with kaloba, where a high
dose of kaloba seemed to increase the cytokine production. In
conclusion, we found that caffeine and quercetin have potential as
immunosuppressant and kaloba as immunostimulant.
Abstract: This study has been presented which is a detailed
work of seismic microzonation of the city center. For seismic
microzonation area of 225 km2 has been selected as the study area.
MASW (Multichannel analysis of surface wave) and seismic
refraction methods have been used to generate one-dimensional shear
wave velocity profile at 250 locations and two-dimensional profile at
60 locations. These shear wave velocities are used to estimate
equivalent shear wave velocity in the study area at every 2 and 5 m
intervals up to a depth of 60 m. Levels of equivalent shear wave
velocity of soil are used the classified of the study area. After the
results of the study, it must be considered as components of urban
planning and building design of Denizli and the application and use
of these results should be required and enforced by municipal
authorities.
Abstract: This paper involved the performance of a hightemperature
X-Ray powder diffraction analysis (XRD) of a sample of
chemical gypsum generated in the production of titanium white; this
gypsum originates by neutralizing highly acidic water with limestone
suspension. Specifically, it was gypsum formed in the first stage of
neutralization when the resulting material contains, apart from
gypsum, a number of waste products resulting from the
decomposition of ilmenite by sulphuric acid. So it can be described as
red titanogypsum. By conducting the experiment using XRD
apparatus Bruker D8 Advance with a Cu anode (λkα=1.54184 Å)
equipped with high-temperature chamber Anton Paar HTK 16, it was
possible to identify clearly in the sample each phase transition in the
system of CaSO4·xH2O.
Abstract: This study aimed at investigating whether the
functional brain networks constructed using the initial EEG (obtained
when patients first visited hospital) can be correlated with the
progression of cognitive decline calculated as the changes of
mini-mental state examination (MMSE) scores between the latest and
initial examinations. We integrated the time–frequency cross mutual
information (TFCMI) method to estimate the EEG functional
connectivity between cortical regions, and the network analysis based
on graph theory to investigate the organization of functional networks
in aMCI. Our finding suggested that higher integrated functional
network with sufficient connection strengths, dense connection
between local regions, and high network efficiency in processing
information at the initial stage may result in a better prognosis of the
subsequent cognitive functions for aMCI. In conclusion, the functional
connectivity can be a useful biomarker to assist in prediction of
cognitive declines in aMCI.
Abstract: Brain functional networks based on resting-state EEG
data were compared between patients with mild Alzheimer’s disease
(mAD) and matched patients with amnestic subtype of mild cognitive
impairment (aMCI). We integrated the time–frequency cross mutual
information (TFCMI) method to estimate the EEG functional
connectivity between cortical regions and the network analysis based
on graph theory to further investigate the alterations of functional
networks in mAD compared with aMCI group. We aimed at
investigating the changes of network integrity, local clustering,
information processing efficiency, and fault tolerance in mAD brain
networks for different frequency bands based on several topological
properties, including degree, strength, clustering coefficient, shortest
path length, and efficiency. Results showed that the disruptions of
network integrity and reductions of network efficiency in mAD
characterized by lower degree, decreased clustering coefficient, higher
shortest path length, and reduced global and local efficiencies in the
delta, theta, beta2, and gamma bands were evident. The significant
changes in network organization can be used in assisting
discrimination of mAD from aMCI in clinical.
Abstract: Segmentation is one of the essential tasks in image
processing. Thresholding is one of the simplest techniques for
performing image segmentation. Multilevel thresholding is a simple
and effective technique. The primary objective of bi-level or
multilevel thresholding for image segmentation is to determine a best
thresholding value. To achieve multilevel thresholding various
techniques has been proposed. A study of some nature inspired
metaheuristic algorithms for multilevel thresholding for image
segmentation is conducted. Here, we study about Particle swarm
optimization (PSO) algorithm, artificial bee colony optimization
(ABC), Ant colony optimization (ACO) algorithm and Cuckoo
search (CS) algorithm.
Abstract: Spectrum sensing is the main feature of cognitive
radio technology. Spectrum sensing gives an idea of detecting the
presence of the primary users in a licensed spectrum. In this paper we
compare the theoretical results of detection probability of different
fading environments like Rayleigh, Rician, Nakagami-m fading
channels with the simulation results using energy detection based
spectrum sensing. The numerical results are plotted as Pf Vs Pd for
different SNR values, fading parameters. It is observed that
Nakagami fading channel performance is better than other fading
channels by using energy detection in spectrum sensing. A MATLAB
simulation test bench has been implemented to know the performance
of energy detection in different fading channel environment.
Abstract: This article presents a new vibration diagnostic
method designed to (PM) machines with permanent magnets. Those
devices are commonly used in small wind and water systems or
vehicles drives. The author’s method is very innovative and unique.
Specific structural properties of PM machines are used in this method
- electromotive force (EMF) generated due to vibrations. There was
analysed number of publications which describe vibration diagnostic
methods and tests of electrical PM machines and there was no
method found to determine the technical condition of such machine
basing on their own signals. In this article will be discussed: the
method genesis, the similarity of machines with permanent magnet to
vibration sensor and simulation and laboratory tests results. The
method of determination the technical condition of electrical machine
with permanent magnets basing on its own signals is the subject of
patent application and it is the main thesis of author’s doctoral
dissertation.
Abstract: Novel bio-based polymer electrolyte was synthesized
with LiClO4 as the main source of charge carrier. Initially,
polyurethane-LiClO4 polymer electrolytes were synthesized via
prepolymerization method with different NCO/OH ratios and labelled
them as PU1, PU2, PU3 and PU4. Fourier transform infrared (FTIR)
analysis indicates the co-ordination between Li+ ion and polyurethane
in PU1. Differential scanning calorimetry (DSC) analysis indicates
PU1 has the highest glass transition temperature (Tg) corresponds to
the most abundant urethane group which is the hard segment in PU1.
Scanning electron microscopy (SEM) shows the good miscibility
between lithium salt and the polymer. The study found that PU1
possessed the greatest ionic conductivity and the lowest activation
energy, Ea. All the polyurethanes exhibited linear Arrhenius
variations indicating ion transport via simple lithium ion hopping in
polyurethane. This research proves the NCO content in polyurethane
plays an important role in affecting the ionic conductivity of this
polymer electrolyte.
Abstract: The effect of trucks on the level of service is
determined by considering passenger car equivalents (PCE) of trucks.
The current version of Highway Capacity Manual (HCM) uses a
single PCE value for all tucks combined. However, the composition
of truck traffic varies from location to location; therefore, a single
PCE value for all trucks may not correctly represent the impact of
truck traffic at specific locations. Consequently, present study
developed separate PCE values for single-unit and combination
trucks to replace the single value provided in the HCM on different
freeways. Site specific PCE values, were developed using concept of
spatial lagging headways (that is the distance between rear bumpers
of two vehicles in a traffic stream) measured from field traffic data.
The study used data from four locations on a single urban freeway
and three different rural freeways in Indiana. Three-stage-leastsquares
(3SLS) regression techniques were used to generate models
that predicted lagging headways for passenger cars, single unit trucks
(SUT), and combination trucks (CT). The estimated PCE values for
single-unit and combination truck for basic urban freeways (level
terrain) were: 1.35 and 1.60, respectively. For rural freeways the
estimated PCE values for single-unit and combination truck were:
1.30 and 1.45, respectively. As expected, traffic variables such as
vehicle flow rates and speed have significant impacts on vehicle
headways. Study results revealed that the use of separate PCE values
for different truck classes can have significant influence on the LOS
estimation.
Abstract: This study is an attempt to raise the awareness of the
stakeholders and the authorities on the sensitivity of Algerian
secondary school teachers of English as a Foreign Language about
the students’ loss of English language skills learned during formal
schooling with effort and at expense and the supposed measures to
arrest that loss. Data was collected from secondary school teachers of
EFL and analyzed quantitatively using a questionnaire containing
open-ended and close-ended questions. The results advocate a
consensus about the need for actions to be adopted to make
assessment techniques outcome-oriented. Most of the participants
were in favor of including curricular activities involving
contextualized learning, problem-solving learning critical selfawareness,
self and peer-assisted learning, use of computers and
internet so as to make learners autonomous.
Abstract: Different order modulations combined with different
coding schemes, allow sending more bits per symbol, thus achieving
higher throughputs and better spectral efficiencies. However, it must
also be noted that when using a modulation technique such as 64-
QAM with less overhead bits, better signal-to-noise ratios (SNRs) are
needed to overcome any Inter symbol Interference (ISI) and maintain
a certain bit error ratio (BER). The use of adaptive modulation allows
wireless technologies to yielding higher throughputs while also
covering long distances. The aim of this paper is to implement an
Adaptive Modulation and Coding (AMC) features of the WiMAX
PHY in MATLAB and to analyze the performance of the system in
different channel conditions (AWGN, Rayleigh and Rician fading
channel) with channel estimation and blind equalization. Simulation
results have demonstrated that the increment in modulation order
causes to increment in throughput and BER values. These results
derived a trade-off among modulation order, FFT length, throughput,
BER value and spectral efficiency. The BER changes gradually for
AWGN channel and arbitrarily for Rayleigh and Rician fade
channels.