Abstract: 3-roller conical bending process is widely used in the
industries for manufacturing of conical sections and shells. It
involves static as well dynamic bending stages. Analytical models for
prediction of bending force during static as well as dynamic bending
stage are available in the literature. In this paper bending forces
required for static bending stage and dynamic bending stages have
been compared using the analytical models. It is concluded that force
required for dynamic bending is very less as compared to the bending
force required during the static bending stage.
Abstract: This paper presents a new automatic vehicle detection
method from very high resolution aerial images to measure traffic
density. The proposed method starts by extracting road regions from
image using road vector data. Then, the road image is divided into
equal sections considering resolution of the images. Gradient vectors
of the road image are computed from edge map of the corresponding
image. Gradient vectors on the each boundary of the sections are
divided where the gradient vectors significantly change their
directions. Finally, number of vehicles in each section is carried out
by calculating the standard deviation of the gradient vectors in each
group and accepting the group as vehicle that has standard deviation
above predefined threshold value. The proposed method was tested in
four very high resolution aerial images acquired from Istanbul,
Turkey which illustrate roads and vehicles with diverse
characteristics. The results show the reliability of the proposed
method in detecting vehicles by producing 86% overall F1 accuracy
value.
Abstract: This paper presents development results of usage of
C-OTDR monitoring systems for rail traffic management. The COTDR
method is based on vibrosensitive properties of optical fibers.
Analysis of Rayleigh backscattering radiation parameters changes
which take place due to microscopic seismoacoustic impacts on the
optical fiber allows to determine seismoacoustic emission source
positions and to identify their types. This approach proved successful
for rail traffic management (moving block system, weigh- in-motion
system etc.).
Abstract: Metal thin-walled members have been widely used in
building industry. Usually they are utilized as purlins, girts or ceiling
beams. Due to slenderness of thin-walled cross-sections these
structural members are prone to stability problems (e.g. flexural
buckling, lateral torsional buckling). If buckling is not
constructionally prevented their resistance is limited by buckling
strength. In practice planar members of roof or wall cladding can be
attached to thin-walled members. These elements reduce
displacement of thin-walled members and therefore increase their
buckling strength. If this effect is taken into static assessment more
economical sections of thin-walled members might be utilized and
certain savings of material might be achieved. This paper focuses on
problem of determination of critical load of steel thin-walled beams
with lateral continuous restraint which is crucial for lateral torsional
buckling assessment.
Abstract: Channel sections are widely used in practice as beams.
However, design rules for eccentrically loaded (not through shear
center) beams with channel cross- sections are not available in
Eurocode 3. This paper compares the ultimate loads based on the
adjusted design rules for lateral torsional buckling of eccentrically
loaded channel beams in bending to the ultimate loads obtained with
Finite Element (FE) simulations on the basis of a parameter study.
Based on the proposed design rule, this study has led to a new design
rule which conforms to Eurocode 3.
Abstract: The aim of this research is to identify the key factors in shipping company’s port selection in order to providing their requirement. To identify and rank factors that play the main role in selecting port for providing the ship requirement, at the first step, data were collected via Semi-structured interviews, the aim was to generate knowledge on how shipping company select the port and suppliers for providing their needs. 37 port selection factors were chosen from the previous researches and field interviews and have been categorized into two groups of port's factor and the factors of services of suppliers companies. The current study adopts a questionnaire survey to the main shipping companies' operators in Iran. Their responses reveal that level of services of supplying companies and customs rules play the important role in selecting the ports. Our findings could affect decisions made by port authorities to consider that supporting the privet sections for ship chandelling business could have the best result in attracting ships.
Abstract: The main objective of this paper is to provide a new
methodology for road safety assessment in Oman through the
development of suitable accident prediction models. GLM technique
with Poisson or NBR using SAS package was carried out to develop
these models. The paper utilized the accidents data of 31 un-signalized
T-intersections during three years. Five goodness-of-fit
measures were used to assess the overall quality of the developed
models. Two types of models were developed separately; the flow-based
models including only traffic exposure functions, and the full
models containing both exposure functions and other significant
geometry and traffic variables.
The results show that, traffic exposure functions produced much
better fit to the accident data. The most effective geometric variables
were major-road mean speed, minor-road 85th percentile speed,
major-road lane width, distance to the nearest junction, and right-turn
curb radius.
The developed models can be used for intersection treatment or
upgrading and specify the appropriate design parameters of T-intersections.
Finally, the models presented in this thesis reflect the intersection
conditions in Oman and could represent the typical conditions in
several countries in the middle east area, especially gulf countries.
Abstract: This paper presents experimental investigation and
finite element analysis on buckling behavior of irregular section coldformed
steel columns under axially concentric loading. For the
experimental study, four different sections of columns were tested to
investigate effect of stiffening and width-to-thickness ratio on
buckling behavior. For each of the section, three lengths of 230, 950
and 1900 mm. were studied representing short, intermediate long and
long columns, respectively. Then, nonlinear finite element analyses
of the tested columns were performed. The comparisons in terms of
load-deformation response and buckling mode show good agreement
and hence the FEM models were validated. Parametric study of
stiffening element and thickness of 1.0, 1.15, 1.2, 1.5, 1.6 and 2.0
mm. was analyzed. The test results showed that stiffening effect pays
a large contribution to prevent distortional mode. The increase in wall
thickness enhanced buckling stress beyond the yielding strength in
short and intermediate columns, but not for the long columns.
Abstract: In general, codes and regulations consider seismic
loads only for completed structures of the bridges while, evaluation
of incomplete structure of bridges, especially those constructed by
free cantilever method, under these loads is also of great importance.
Hence, this research tried to study the behavior of incomplete
structure of common bridge type (box girder bridge), in construction
phase under vertical seismic loads. Subsequently, the paper provided
suitable guidelines and solutions to resist this destructive
phenomenon. Research results proved that use of preventive methods
can significantly reduce the stresses resulted from vertical seismic
loads in box cross sections to an acceptable range recommended by
design codes.
Abstract: To determine the potential of a low cost Irish
engineered timber product to replace high cost solid timber for use in
bending active structures such as gridshells a single Irish engineered
timber product in the form of orientated strand board (OSB) was
selected. A comparative study of OSB and solid timber was carried
out to determine the optimum properties that make a material suitable
for use in gridshells. Three parameters were identified to be relevant
in the selection of a material for gridshells. These three parameters
are the strength to stiffness ratio, the flexural stiffness of
commercially available sections, and the variability of material and
section properties. It is shown that when comparing OSB against
solid timber, OSB is a more suitable material for use in gridshells that
are at the smaller end of the scale and that have tight radii of
curvature. Typically, for solid timber materials, stiffness is used as an
indicator for strength and engineered timber is no different. Thus, low
flexural stiffness would mean low flexural strength. However, when
it comes to bending active gridshells, OSB offers a significant
advantage. By the addition of multiple layers, an increased section
size is created, thus endowing the structure with higher stiffness and
higher strength from initial low stiffness and low strength materials
while still maintaining tight radii of curvature. This allows OSB to
compete with solid timber on large scale gridshells. Additionally, a
preliminary sustainability study using a set of sustainability indicators
was carried out to determine the relative sustainability of building a
large-scale gridshell in Ireland with a primary focus on economic
viability but a mention is also given to social and environmental
aspects. For this, the Savill garden gridshell in the UK was used as
the functional unit with the sustainability of the structural roof
skeleton constructed from UK larch solid timber being compared
with the same structure using Irish OSB. Albeit that the advantages of
using commercially available OSB in a bending active gridshell are
marginal and limited to specific gridshell applications, further study
into an optimised engineered timber product is merited.
Abstract: The check-in area of airport terminal is one of the
busiest sections at airports at certain periods. The passengers are
subjected to queues and delays during the check-in process. These
delays and queues are due to constraints in the capacity of service
facilities. In this project, the airport terminal is decomposed into
several check-in areas. The airport check-in scheduling problem
requires both a deterministic (integer programming) and stochastic
(simulation) approach. Integer programming formulations are
provided to minimize the total number of counters in each check-in
area under the realistic constraint that counters for one and the same
flight should be adjacent and the desired number of counters
remaining in each area should be fixed during check-in operations.
By using simulation, the airport system can be modeled to study the
effects of various parameters such as number of passengers on a
flight and check-in counter opening and closing time.
Abstract: In the past few decades, the field of chemistry
education has grown tremendously and researches indicated that after
traditional chemistry instruction students often lacked deep
conceptual understanding and failed to integrate their ideas into
coherent conceptual framework. For several concepts in chemistry,
students at all levels have demonstrated difficulty in changing their
initial perceptions. Their perceptions are most often wrong and don't
agree with correct scientific concepts. This study explored the
effectiveness of intervention discussion sections for a college general
chemistry course designed to apply research on students
preconceptions, knowledge integration and student explanation.
Three interventions discussions lasting three hours on bond energy
and spontaneity were done tested and intervention (treatment)
students’ performances were compared with that of control group
which did not use the experimental pedagogy. Results indicated that
this instruction which was capable of identifying students'
misconceptions, initial conceptions and integrating those ideas into
class discussion led to enhanced conceptual understanding and better
achievement for the experimental group.
Abstract: Theory of interpretation of electromagnetic fields studied in the electrical prospecting with direct current is mainly developed for the case of a horizontal surface observation. However in practice we often have to work in difficult terrain surface. Conducting interpretation without the influence of topography can cause non-existent anomalies on sections. This raises the problem of studying the impact of different shapes of ground surface relief on the results of electrical prospecting's research. This research examines the numerical solutions of the direct problem of electrical prospecting for two-dimensional and three-dimensional media, taking into account the terrain. The problem is solved using the method of integral equations. The density of secondary currents on the relief surface is obtained.
Abstract: In this study, several crossplots of the P-impedance
with the lithology logs (gamma ray, neutron porosity, deep resistivity,
water saturation and Vp/Vs curves) were made in three available
wells, which were drilled in central part of the Blue Nile basin in
depths varies from 1460m to 1600m. These crossplots were
successful to discriminate between sand and shale when using PImpedance
values, and between the wet sand and the pay sand when
using both P-impedance and Vp/Vs together. Also some impedance
sections were converted to porosity sections using linear formula to
characterize the reservoir in terms of porosity. The used crossplots
were created on log resolution, while the seismic resolution can
identify only the reservoir, unless a 3D seismic angle stacks were
available; then it would be easier to identify the pay sand with great
confidence; through high resolution seismic inversion and
geostatistical approach when using P-impedance and Vp/Vs volumes.
Abstract: In this paper, groundwater seepage into Amirkabir
tunnel has been estimated using analytical and numerical methods for
14 different sections of the tunnel. Site Groundwater Rating (SGR)
method also has been performed for qualitative and quantitative
classification of the tunnel sections. The obtained results of above
mentioned methods were compared together. The study shows
reasonable accordance with results of the all methods unless for two
sections of tunnel. In these two sections there are some significant
discrepancies between numerical and analytical results mainly
originated from model geometry and high overburden. SGR and the
analytical and numerical calculations, confirm high concentration of
seepage inflow in fault zones. Maximum seepage flow into tunnel has
been estimated 0.425 lit/sec/m using analytical method and 0.628
lit/sec/m using numerical method occured in crashed zone. Based on
SGR method, six sections of 14 sections in Amirkabir tunnel axis are
found to be in "No Risk" class that is supported by the analytical and
numerical seepage value of less than 0.04 lit/sec/m.
Abstract: Artificial intelligence applications are commonly used
in industry in many fields in parallel with the developments in the
computer technology. In this study, a fire room was prepared for the
resistance of wooden construction elements and with the mechanism
here, the experiments of polished materials were carried out. By
utilizing from the experimental data, an artificial neural network
(ANN) was modelled in order to evaluate the final cross sections of
the wooden samples remaining from the fire. In modelling,
experimental data obtained from the fire room were used. In the
developed system, the first weight of samples (ws-gr), preliminary
cross-section (pcs-mm2), fire time (ft-minute), and fire temperature
(t-oC) as input parameters and final cross-section (fcs-mm2) as output
parameter were taken. When the results obtained from ANN and
experimental data are compared after making statistical analyses, the
data of two groups are determined to be coherent and seen to have no
meaning difference between them. As a result, it is seen that ANN
can be safely used in determining cross sections of wooden materials
after fire and it prevents many disadvantages.
Abstract: Vehicular Adhoc Network (VANET) is a new
technology which aims to ensure intelligent inter-vehicle
communications, seamless internet connectivity leading to improved
road safety, essential alerts, and access to comfort and entertainment.
VANET operations are hindered by mobile node’s (vehicles)
uncertain mobility. Routing algorithms use metrics to evaluate which
path is best for packets to travel. Metrics like path length (hop count),
delay, reliability, bandwidth, and load determine optimal route. The
proposed scheme exploits link quality, traffic density, and
intersections as routing metrics to determine next hop. This study
enhances Geographical Routing Protocol (GRP) using fuzzy
controllers while rules are optimized with Bee Swarm Optimization
(BSO). Simulations results are compared to conventional GRP.
Abstract: The paper deals with the diagnostics of steel roof
structure of the winter sports halls built in 1970 year. The necessity
of the diagnostics has been given by the requirement to the evaluation
design of this structure, which has been caused by the new situation
in the field of the loadings given by the validity of the European
Standards in the Czech Republic from 2010 year. Due to these
changes in the normative rules, in practice existing structures are
gradually subjected to the evaluation design and depending on its
results to the strengthening or reconstruction, respectively. Steel roof
is composed of plane truss main girders, purlins and bracings and the
roof structure is supported by two arch main girders with the span of
L = 84 m. The in situ diagnostics of the roof structure was oriented to
the following parts: (i) determination and evaluation of the actual
material properties of used steel and (ii) verification of the actual
dimensions of the structural members. For the solution the nondestructive
methods have been used for in situ measurement. For the
indicative determination of steel strengths the modified method based
on the determination of Rockwell’s hardness has been used. For the
verification of the member’s dimensions (thickness of hollow
sections) the ultrasound method has been used. This paper presents
the results obtained using these testing methods and their evaluation,
from the viewpoint of the usage for the subsequent static assessment
and design evaluation of the existing structure. For the comparison,
the examples of the similar evaluations realized for steel structures of
the stadiums in Olomouc and Jihlava cities are briefly illustrated, too.
Abstract: Image search engines rely on the surrounding textual
keywords for the retrieval of images. It is a tedious work for the
search engines like Google and Bing to interpret the user’s search
intention and to provide the desired results. The recent researches
also state that the Google image search engines do not work well on
all the images. Consequently, this leads to the emergence of efficient
image retrieval technique, which interprets the user’s search intention
and shows the desired results. In order to accomplish this task, an
efficient image re-ranking framework is required. Sequentially, to
provide best image retrieval, the new image re-ranking framework is
experimented in this paper. The implemented new image re-ranking
framework provides best image retrieval from the image dataset by
making use of re-ranking of retrieved images that is based on the
user’s desired images. This is experimented in two sections. One is
offline section and other is online section. In offline section, the reranking
framework studies differently (reference classes or Semantic
Spaces) for diverse user query keywords. The semantic signatures get
generated by combining the textual and visual features of the images.
In the online section, images are re-ranked by comparing the
semantic signatures that are obtained from the reference classes with
the user specified image query keywords. This re-ranking
methodology will increases the retrieval image efficiency and the
result will be effective to the user.
Abstract: The thyroid gland is the largest classic endocrine
organ that effects many organs of the body and plays a significant
role in the process of Metabolism in animals. The aim of this study
was to investigate the prevalence of thyroid disorders diagnosed by
ultrasound and microscopic Lesions of the thyroid during the
slaughter of apparently healthy One Humped Camels (Camelus
dromedarius) in Iran. Randomly, 520 male camels (With an age
range of 4 to 8 years), were studied in 2012 to 2013. The Camels’
thyroid glands were evaluated by sonographic examination. In both
longitudinal and transverse view and then tissue sections were
provide and stained with H & E and finally examined by light
microscopy. The results obtained indicated the following:
hyperplastic goiter (21%), degenerative changes (12%), follicular
cysts (8%), follicular atrophy (4%), nodular hyperplasia (3%),
adenoma (1%), carcinoma (1%) and simple goiter colloid (1%).
Ultrasound evaluation of thyroid gland in adenoma and carcinoma
showed enlargement and irregular of the gland, decreased
echogenicity, and the heterogeneous thyroid parenchyma. Also, in
follicular cysts were observed in the enlarged gland with no echo
structures of different sizes and decreased echogenicity as a local or
general. In nodular hyperplasia, increase echogenicity and
heterogeneous parenchymal were seen. These findings suggest the
use of sonography and pathology as a screening test in the diagnosis
of complications of thyroid disorders.