Abstract: In this paper, we consider a cognitive relay network
(CRN) in which the primary receiver (PR) is protected by peak
transmit power ¯PST and/or peak interference power Q constraints.
In addition, the interference effect from the primary transmitter (PT)
is considered to show its impact on the performance of the CRN. We
investigate the outage probability (OP) and outage capacity (OC) of
the CRN by deriving closed-form expressions over Rayleigh fading
channel. Results show that both the OP and OC improve by increasing
the cooperative relay nodes as well as when the PT is far away from
the SR.
Abstract: In recent years, fire accidents have been steadily
increased and the amount of property damage caused by the accidents
has gradually raised. Damaging building structure, fire incidents bring
about not only such property damage but also strength degradation and
member deformation. As a result, the building structure undermines its
structural ability. Examining the degradation and the deformation is
very important because reusing the building is more economical than
reconstruction. Therefore, engineers need to investigate the strength
degradation and member deformation well, and make sure that they
apply right rehabilitation methods. This study aims at evaluating
deformation characteristics of fire damaged and rehabilitated normal
strength concrete beams through both experiments and finite element
analyses. For the experiments, control beams, fire damaged beams and
rehabilitated beams are tested to examine deformation characteristics.
Ten test beam specimens with compressive strength of 21MPa are
fabricated and main test variables are selected as cover thickness of
40mm and 50mm and fire exposure time of 1 hour or 2 hours. After
heating, fire damaged beams are air-recurred for 2 months and
rehabilitated beams are repaired with polymeric cement mortar after
being removed the fire damaged concrete cover. All beam specimens
are tested under four points loading. FE analyses are executed to
investigate the effects of main parameters applied to experimental
study. Test results show that both maximum load and stiffness of the
rehabilitated beams are higher than those of the fire damaged beams.
In addition, predicted structural behaviors from the analyses also show
good rehabilitation effect and the predicted load-deflection curves are
similar to the experimental results. For the further, the proposed
analytical method can be used to predict deformation characteristics of
fire damaged and rehabilitated concrete beams without suffering from
time and cost consuming of experimental process.
Abstract: In this paper, we consider some integrable Heisenberg
Ferromagnet Equations with self-consistent potentials. We study
their Lax representations. In particular we derive their equivalent
counterparts in the form of nonlinear Schr¨odinger type equations.
We present the integrable reductions of the Heisenberg Ferromagnet
Equations with self-consistent potentials. These integrable Heisenberg
Ferromagnet Equations with self-consistent potentials describe
nonlinear waves in ferromagnets with some additional physical fields.
Abstract: New design of three dimensional (3D) flywheel system
based on gimbal and gyro mechanics is proposed. The 3D flywheel
device utilizes the rotational motion of three spherical shells and the
conservation of angular momentum to achieve planar locomotion.
Actuators mounted to the ring-shape frames are installed within the
system to drive the spherical shells to rotate, for the purpose of steering
and stabilization. Similar to the design of 2D flywheel system, it is
expected that the spherical shells may function like a “flyball” to store
and supply mechanical energy; additionally, in comparison with
typical single-wheel and spherical robots, the 3D flywheel can be used
for developing omnidirectional robotic systems with better mobility.
The Lagrangian method is applied to derive the equation of motion of
the 3D flywheel system, and simulation studies are presented to verify
the proposed design.
Abstract: The aim of the present study is to detect the chaotic
behavior in monetary economic relevant dynamical system. The
study employs three different forms of Taylor rules: current, forward,
and backward looking. The result suggests the existence of the
chaotic behavior in all three systems. In addition, the results strongly
represent that using expectations in policy rule especially rational
expectation hypothesis can increase complexity of the system and
leads to more chaotic behavior.
Abstract: Bicycle Level of Service (BLOS) is a measure for
evaluating street conditions for cyclists. Currently, various methods
are proposed for BLOS. These analytical methods however have
some drawbacks: they usually assume cyclists as users that can share
street facilities with motorized vehicles, it is not easy to link them to
design process and they are not easy to follow. In addition, they only
support a narrow range of cycling facilities and may not be applicable
for all situations. Along this, the current paper introduces various
effective design factors for bicycle-friendly streets. This study
considers cyclists as users of streets who have special needs and
facilities. Therefore, the key factors that influence BLOS based on
different cycling facilities that are proposed by developed guidelines
and literature are identified. The combination of these factors
presents a complete set of effective design factors for bicycle-friendly
streets. In addition, the weight of each factor in existing BLOS
models is estimated and these effective factors are ranked based on
these weights. These factors and their weights can be used in further
studies to propose special bicycle-friendly street design model.
Abstract: In this study, nuclear magnetic resonance
spectroscopy and nuclear quadrupole resonance spectroscopy
parameters of 14N (Nitrogen in imidazole ring) in N–H…O hydrogen
bonding for Histidine hydrochloride monohydrate were calculated via
density functional theory. We considered a five-molecule model
system of Histidine hydrochloride monohydrate. Also we examined
the trends of environmental effect on hydrogen bonds as well as
cooperativity. The functional used in this research is M06-2X which
is a good functional and the obtained results has shown good
agreement with experimental data. This functional was applied to
calculate the NMR and NQR parameters. Some correlations among
NBO parameters, NMR and NQR parameters have been studied
which have shown the existence of strong correlations among them.
Furthermore, the geometry optimization has been performed using
M062X/6-31++G(d,p) method. In addition, in order to study
cooperativity and changes in structural parameters, along with
increase in cluster size, natural bond orbitals have been employed.
Abstract: Artificial neural networks have gained a lot of interest
as empirical models for their powerful representational capacity,
multi input and output mapping characteristics. In fact, most feedforward
networks with nonlinear nodal functions have been proved to
be universal approximates. In this paper, we propose a new
supervised method for color image classification based on selforganizing
feature maps (SOFM). This algorithm is based on
competitive learning. The method partitions the input space using
self-organizing feature maps to introduce the concept of local
neighborhoods. Our image classification system entered into RGB
image. Experiments with simulated data showed that separability of
classes increased when increasing training time. In additional, the
result shows proposed algorithms are effective for color image
classification.
Abstract: This paper presents a state-of-the-art survey of the
operations research models developed for internal audit planning.
Two alternative approaches have been followed in the literature for
audit planning: (1) identifying the optimal audit frequency; and (2)
determining the optimal audit resource allocation. The first approach
identifies the elapsed time between two successive audits, which can
be presented as the optimal number of audits in a given planning
horizon, or the optimal number of transactions after which an audit
should be performed. It also includes the optimal audit schedule. The
second approach determines the optimal allocation of audit frequency
among all auditable units in the firm. In our review, we discuss both
the deterministic and probabilistic models developed for audit
planning. In addition, game theory models are reviewed to find the
optimal auditing strategy based on the interactions between the
auditors and the clients.
Abstract: High Voltage Direct Current (HVDC) power
transmission is employed to move large amounts of electric power.
There are several possibilities to enhance the transient stability in a
power system. One adequate option is by using the high
controllability of the HVDC if HVDC is available in the system. This
paper presents a control technique for HVDC to enhance the transient
stability. The strategy controls the power through the HVDC to help
make the system more transient stable during disturbances. Loss of
synchronism is prevented by quickly producing sufficient
decelerating energy to counteract accelerating energy gained during.
In this study, the power flow in the HVDC link is modulated with the
addition of an auxiliary signal to the current reference of the rectifier
firing angle controller. This modulation control signal is derived from
speed deviation signal of the generator utilizing a PD controller; the
utilization of a PD controller is suitable because it has the property of
fast response. The effectiveness of the proposed controller is
demonstrated with a SMIB test system.
Abstract: In present global scenario, aluminum alloys are
coining the attention of many innovators as competing structural
materials for automotive and space applications. Comparing to other
challenging alloys, especially, 7xxx series aluminum alloys have
been studied seriously because of benefits such as moderate strength;
better deforming characteristics and affordable cost. It is expected
that substitution of aluminum alloys for steels will result in great
improvements in energy economy, durability and recyclability.
However, it is necessary to improve the strength and the formability
levels at low temperatures in aluminum alloys for still better
applications. Aluminum–Zinc–Magnesium with or without other
wetting agent denoted as 7XXX series alloys are medium strength
heat treatable alloys. In addition to Zn, Mg as major alloying
additions, Cu, Mn and Si are the other solute elements which
contribute for the improvement in mechanical properties by suitable
heat treatment process. Subjecting to suitable treatments like age
hardening or cold deformation assisted heat treatments; known as low
temperature thermomechanical treatments (LTMT) the challenging
properties might be incorporated. T6 is the age hardening or
precipitation hardening process with artificial aging cycle whereas T8
comprises of LTMT treatment aged artificially with X% cold
deformation. When the cold deformation is provided after solution
treatment, there is increase in hardness related properties such as
wear resistance, yield and ultimate strength, toughness with the
expense of ductility. During precipitation hardening both hardness
and strength of the samples are increasing. The hardness value may
further improve when room temperature deformation is positively
supported with age hardening known as thermomechanical treatment.
It is intended to perform heat treatment and evaluate hardness, tensile
strength, wear resistance and distribution pattern of reinforcement in
the matrix. 2 to 2.5 and 3 to 3.5 times increase in hardness is reported
in age hardening and LTMT treatments respectively as compared to
as-cast composite. There was better distribution of reinforcements in
the matrix, nearly two fold increase in strength levels and up to 5
times increase in wear resistance are also observed in the present
study.
Abstract: Studying stress and strain trends in the femur and
recognizing femur failure mechanism is very important for
preventing hip fracture in the elderly. The aim of this study was to
identify high stress and strain regions in the femur during normal
walking and falling to find the mechanical behavior and failure
mechanism of the femur. We developed a finite element model of the
femur from the subject’s quantitative computed tomography (QCT)
image and used it to identify potentially high stress and strain regions
during the single-leg stance and the sideways fall. It was found that
fracture may initiate from the superior region of femoral neck and
propagate to the inferior region during a high impact force such as
sideways fall. The results of this study showed that the femur bone is
more sensitive to strain than stress which indicates the effect of
strain, in addition to effect of stress, should be considered for failure
analysis.
Abstract: Present work deals with the possible use of fertigation
in agriculture and its impact on the availability of mineral nitrogen
(Nmin) in topsoil and subsoil horizons. The aim of the present study is
to demonstrate the effect of the organic matter presence in fertigation
on microbial transformation and availability of mineral nitrogen
forms. The main investigation reason is the potential use of pretreated
waste water, as a source of organic carbon (Corg) and residual
nutrients (Nmin) for fertigation. Laboratory experiment has been
conducted to demonstrate the effect of the arable land fertilization
method on the Nmin availability in different depths of the soil with
the usage of model experimental containers filled with soil from
topsoil and podsoil horizons that were taken from the precise area.
Tufted hairgrass (Deschampsia caespitosa) has been chosen as a
model plant. The water source protection zone Brezova nad Svitavou
has been a research area where significant underground reservoirs of
drinking water of the highest quality are located. From the second
half of the last century local sources of drinking water show
nitrogenous compounds increase that get here almost only from
arable lands. Therefore, an attention of the following text focuses on
the fate of mineral nitrogen in the complex plant-soil. Research
results show that the fertigation application with Corg in a
combination with mineral fertilizer can reduce the amount of Nmin
leached from topsoil horizon of agricultural soils. In addition, some
plants biomass production reduces may occur.
Abstract: A new fast growing trend in tourism is ecotourism, in
which tourists visit natural ecosystems under low impact, nonconsumptive
and locally oriented activities. Through these activities
species and habitats are maintained and typically, underdeveloped
regions are emphasized. Ecotourism provides a great alternative,
especially for rural and undeveloped area. At the same time, despite
its many benefits, it also poses many risks for the naturally protected
areas. If ecotourism is practiced improperly degradation and
irreversible damages could be the unwanted result. In addition, the
lack of MSc programs in the field of Ecotourism in Europe makes it a
necessity to be developed. Such an MSc program is being
implemented with the lead partner the Technical University of
Madrid. The entire partnership has six Universities, seven SMEs and
one National Park from seven different countries all over Europe.
The MSc will have 10 educational modules that will be available
online and will prepare professionals that will be able to implement
ecotourism in a sustainable way. Only through awareness and
education a sustainable ecotourism will be achieved in the protected
areas of Europe.
Abstract: Cemented carbides, owing to their excellent
mechanical properties, have been of immense interest in the field of
hard materials for the past few decades. A number of processing
techniques have been developed to obtain high quality carbide tools,
with a wide range of grain size depending on the application and
requirements. Microwave sintering is one of the heating processes,
which has been used to prepare a wide range of materials including
ceramics. A deep understanding of microwave sintering and its
contribution towards control of grain growth and on deformation of
the resulting carbide materials requires further studies and attention.
In addition, the effect of binder materials and their behavior during
microwave sintering is another area that requires clear understanding.
This review aims to focus on microwave sintering, providing
information of how the process works and what type of materials it is
best suited for. In addition, a closer look at some microwave sintered
Tungsten Carbide-Cobalt samples will be taken and discussed,
highlighting some of the key issues and challenges faced in this
research area.
Abstract: The reduction of phosphorus and sulfur in engine oil
are the main topics of this paper. Very reproducible boundary
lubrication tests were conducted as part of Design of Experiment
software (DOE) to study the behavior of fluorinated catalyst iron
fluoride (FeF3), and polutetrafluoroethylene or Teflon (PTFE) in
developing environmentally friendly (reduced P and S) anti-wear
additives for future engine oil formulations. Multi-component
Chevron fully formulated oil (GF3) and Chevron plain oil were used
with the addition of PTFE and catalyst to characterize and analyze
their performance. Lower phosphorus blends were the goal of the
model solution. Experiments indicated that new sub-micron FeF3
catalyst played an important role in preventing breakdown of the
tribofilm.
Abstract: Waste Load Allocation (WLA) strategies usually
intend to find economic policies for water resource management.
Water quality trading (WQT) is an approach that uses discharge
permit market to reduce total environmental protection costs. This
primarily requires assigning discharge limits known as total
maximum daily loads (TMDLs). These are determined by monitoring
organizations with respect to the receiving water quality and
remediation capabilities. The purpose of this study is to compare two
approaches of TMDL assignment for WQT policy in small catchment
area of Haraz River, in north of Iran. At first, TMDLs are assigned
uniformly for the whole point sources to keep the concentrations of
BOD and dissolved oxygen (DO) at the standard level at checkpoint
(terminus point). This was simply simulated and controlled by
Qual2kw software. In the second scenario, TMDLs are assigned
using multi objective particle swarm optimization (MOPSO) method
in which the environmental violation at river basin and total treatment
costs are minimized simultaneously. In both scenarios, the equity
index and the WLA based on trading discharge permits (TDP) are
calculated. The comparative results showed that using economically
optimized TMDLs (2nd scenario) has slightly more cost savings rather
than uniform TMDL approach (1st scenario). The former annually
costs about 1 M$ while the latter is 1.15 M$. WQT can decrease
these annual costs to 0.9 and 1.1 M$, respectively. In other word,
these approaches may save 35 and 45% economically in comparison
with command and control policy. It means that using multi objective
decision support systems (DSS) may find more economical WLA,
however its outcome is not necessarily significant in comparison with
uniform TMDLs. This may be due to the similar impact factors of
dischargers in small catchments. Conversely, using uniform TMDLs
for WQT brings more equity that makes stakeholders not feel that
much envious of difference between TMDL and WQT allocation. In
addition, for this case, determination of TMDLs uniformly would be
much easier for monitoring. Consequently, uniform TMDL for TDP
market is recommended as a sustainable approach. However,
economical TMDLs can be used for larger watersheds.
Abstract: Psyllium gum alone and in combination with
sunflower oil was investigated as a possible alternative edible coating
for improvement of quality and shelf life of fresh-cut papaya.
Different concentrations including 0.5, 1 and 1.5 percent of psyllium
gum were used for coating of fresh-cut papaya. In some samples,
refined sunflower oil was used as a lipid component to increase the
effectiveness of coating in terms of water barrier properties. Soya
lecithin was used as an emulsifier in coatings containing oil.
Pretreatment with 1% calcium chloride was given to maintain the
firmness of fresh-cut papaya cubes. 1% psyllium gum coating was
found to yield better results. Further, addition of oil helped to
maintain the quality and acted as a barrier to water vapour, therefore,
minimizing the weight loss.
Abstract: In this study, the feasibility of incorporating ceramic
waste from bricks (perforated brick and double hollow brick) and
extruded polystyrene (XPS) waste, is analysed.
Results show that it is possible to incorporate up to 25% of
ceramic waste and 4% of XPS waste over the weight of gypsum in a
gypsum matrix. Furthermore, with the addition of ceramic waste an
8% of surface hardness increase and a 25% of capillary water
absorption reduction can be obtained. On the other hand, with the
addition of XPS, a 26% reduction of density and a 37% improvement
of thermal conductivity can be obtained.
The obtained results are favorable to use these materials in order to
produce prefabricated gypsum and also as material for interior
cladding walls.
Abstract: This study aims at developing a novel cold asphalt
concrete binder course mixture by using Ordinary Portland Cement
(OPC) as a replacement for conventional mineral filler (0%-100%)
with new by-product material (LJMU-A2) used as a supplementary
cementitious material. With this purpose, cold asphalt concrete binder
course mixtures with cationic emulsions were studied by means of
stiffness modulus whereas water sensitivity was assessed by
measuring the stiffness modulus ratio before and after sample
conditioning.
The results indicate that a substantial enhancement in the stiffness
modulus and a considerable improvement of water sensitivity
resistance is achieved by adding LJMU-A2 to the cold asphalt
mixtures as a supplementary cementitious material. Moreover, the
addition of LJMU-A2 to those mixtures leads to a stiffness modulus
after 2-day curing compared to that obtained with Portland cement,
which occurs after 7-day curing.