Abstract: Later marine propeller is the main component of ship
propulsion system. For a non-series propeller, it is difficult to
indicate the open water marine propeller performance without an
experimental study to measure the marine propeller parameters.
In the present study, the open water performance of a non-series
marine propeller has been carried out experimentally. The
geometrical aspects of a commercial non-series marine propeller
have been measured for a propeller blade area ratio of 0.3985. The
measured propeller performance parameters were the thrust and
torque coefficients for different propeller rotational speed and
different water channel flow velocity, then the open water
performance for the propeller has been plotted.
In addition, a direct comparison between the obtained
experimental results and a theoretical study of a B-series marine
propeller of the same blade area ratio has been carried out. A
correction factor has been introduced to apply the operating
conditions of the experimental results to that of the theoretical study
for the studied marine propeller.
Abstract: Implemented 5-bit 125-MS/s successive
approximation register (SAR) analog to digital converter (ADC) on
FPGA is presented in this paper.The design and modeling of a high
performance SAR analog to digital converter are based on monotonic
capacitor switching procedure algorithm .Spartan 3 FPGA is chosen
for implementing SAR analog to digital converter algorithm. SAR
VHDL program writes in Xilinx and modelsim uses for showing
results.
Abstract: Run-offs are considered as important hydrological factors in feasibility studies of river engineering and irrigation-related projects under arid and semi-arid condition. Flood control is one of the crucial factor, the management of which while mitigates its destructive consequences, abstracts considerable volume of renewable water resources. The methodology applied here was based on Mizumura, which applied a mathematical model for simple tank to simulate the rainfall-run-off process in a particular water basin using the data from the observational hydrograph. The model was applied in the Dez River water basin adjacent to Greater Dezful region, Iran in order to simulate and estimate the floods. Results indicated that the calculated hydrographs using the simple tank method, SCS-CN model and the observation hydrographs had a close proximity. It was also found that on average the flood time and discharge peaks in the simple tank were closer to the observational data than the CN method. On the other hand, the calculated flood volume in the CN model was significantly closer to the observational data than the simple tank model.
Abstract: In this work we report on preliminary analysis of a novel optoelectronic gas sensor based on an optical fiber integrated with a tetrakis(4-sulfonatophenyl)porphyrin (TPPS) thin film. The sensitive materials are selectively deposited on the core region of a fiber tip by UV light induced deposition technique. A simple and cheap process which can be easily extended to different porphyrin derivatives. When the TPPS film on the fiber tip is exposed to acid and/or base vapors, dramatic changes occur in the aggregation structure of the dye molecules in the film, from J- to H-type, resulting in a profound modification of their corresponding reflectance spectra. From the achieved experimental results it is evident that the presence of intense and narrow band peaks in the reflected spectra could be monitored to detect hazardous vapors.
Abstract: We proposed the use of a Toda-Rayleigh ring as a
central pattern generator (CPG) for controlling hexapodal robots. We
show that the ring composed of six Toda-Rayleigh units coupled to
the limb actuators reproduces the most common hexapodal gaits. We
provide an electrical circuit implementation of the CPG and test our
theoretical results obtaining fixed gaits. Then we propose a method
of incorporation of the actuator (motor) dynamics in the CPG. With
this approach we close the loop CPG – environment – CPG, thus
obtaining a decentralized model for the leg control that does not
require higher level intervention to the CPG during locomotion in
a nonhomogeneous environments. The gaits generated by the novel
CPG are not fixed, but adapt to the current robot bahvior.
Abstract: An alternative approach to the use of Discrete Fourier
Transform (DFT) for Magnetic Resonance Imaging (MRI) reconstruction
is the use of parametric modeling technique. This method
is suitable for problems in which the image can be modeled by
explicit known source functions with a few adjustable parameters.
Despite the success reported in the use of modeling technique as an
alternative MRI reconstruction technique, two important problems
constitutes challenges to the applicability of this method, these are
estimation of Model order and model coefficient determination. In
this paper, five of the suggested method of evaluating the model
order have been evaluated, these are: The Final Prediction Error
(FPE), Akaike Information Criterion (AIC), Residual Variance (RV),
Minimum Description Length (MDL) and Hannan and Quinn (HNQ)
criterion. These criteria were evaluated on MRI data sets based on the
method of Transient Error Reconstruction Algorithm (TERA). The
result for each criterion is compared to result obtained by the use of a
fixed order technique and three measures of similarity were evaluated.
Result obtained shows that the use of MDL gives the highest measure
of similarity to that use by a fixed order technique.
Abstract: In the fifteenth century, the Malacca Empire emerged
as the centre of Islamic civilization in the Malay Archipelago. The
history had been recorded in Sulalat Al-Salatin, an important literary
source about the genealogy of all Kings in Malacca. The objective of
this study was to analyze the understanding of sayings from Prophet
Muhammad among Malays in Malacca during the fifteenth century
through all of the hadith quoted in Sulalat Al-Salatin. This study used
content analysis methodology to validate the sayings where all of
them were critically analyzed and compared with the classical hadith
sources from prominent Muslim scholars. As a result, only two out of
the four quotations were considered as authentic sayings of Prophet
Muhammad. This study also showed the importance of the palace as
the centre of the Islamic education system and the role played by
Muslim preachers from outside of Malacca to propagate Islam in
Malacca.
Abstract: This paper presents a general trainable framework
for fast and robust upright human face and non-human object
detection and verification in static images. To enhance the
performance of the detection process, the technique we develop is
based on the combination of fast neural network (FNN) and
classical neural network (CNN). In FNN, a useful correlation is
exploited to sustain high level of detection accuracy between input
image and the weight of the hidden neurons. This is to enable the
use of Fourier transform that significantly speed up the time
detection. The combination of CNN is responsible to verify the
face region. A bootstrap algorithm is used to collect non human
object, which adds the false detection to the training process of the
human and non-human object. Experimental results on test images
with both simple and complex background demonstrate that the
proposed method has obtained high detection rate and low false
positive rate in detecting both human face and non-human object.
Abstract: In this paper, half bridge DC-DC converters with
transformer isolation presented in the literature are analyzed for highcurrent
and low-voltage applications under the same operation
conditions, and compared in terms of losses and efficiency. The
conventional and improved half-bridge DC-DC converters are
simulated, and current and voltage waveforms are obtained for input
voltage Vdc=500V, output current IO=450A, output voltage VO=38V
and switching frequency fS=20kHz. IGBTs are used as power
semiconductor switches. The power losses of the semiconductor
devices are calculated from current and voltage waveforms. From
simulation results, it is seen that the capacitor switched half bridge
converter has the best efficiency value, and can be preferred at high
power and high frequency applications.
Abstract: A variational method is used to obtain the growth rate of a transverse long-wavelength perturbation applied to the soliton solution of a nonlinear Schr¨odinger equation with a three-half order potential. We demonstrate numerically that this unstable perturbed soliton will eventually transform into a cylindrical soliton.
Abstract: The effect of flooding can be a serious problem for
wheat farmers, even at dry land condition. Amount of flooding
damage depends on duration flooding, developmental stage, wheat
type and variety. Therefore as a factorial experiment in randomized
complete design based on winter bread wheat cultivars (Pishtaz,
Marvdasht, Shiraz, Zarin, Shahriar, C-81-4, Sardari, Agosta seed,
FGS and Azar2) at stages (Non- flooding stress, flooding at tillering
and stem elongation stages for 15 days) carried out in Faculty of
Agriculture, Razi University, Kermanshah, Iran. During flooding,
soil environment of plant roots were water saturated. Analysis of
variance showed that flooding had a significant effect on the number
of grains per spike, grain weight per spike and a grain weight. Hence
flooding reduces the number of grain per spike between 27.1 to 42.5
percent, grain weight per spike between 34.7 to 54.4 percent and
single grain weight between 12.1 to 15.1 percent. Effects of flooding
at the tillering stage reduced higher than stem elongation stage on
studied traits. The result also showed that flooding at tillering stage
delayed spikelet primordial and floret. Between wheat cultivars was
significant for traits, but were different reactions. "Shiraz", "Zarin"
and "Shahriar" had the most no. grain per spike, but "Zarin" and
"Sardari" had the most grain weight per spike and single grain
weight, respectively. Also, interaction between start of flooding and
cultivar was significant.
Abstract: A new Markovianity approach is introduced in this
paper. This approach reduces the response time of classic Markov
Random Fields approach. First, one region is determinated by a
clustering technique. Then, this region is excluded from the study.
The remaining pixel form the study zone and they are selected for a
Markovianity segmentation task. With Selective Markovianity
approach, segmentation process is faster than classic one.
Abstract: In this paper, an efficient wave concept iterative
process (WCIP) with auxiliary Sources is presented for full wave
investigation of an active microwave structure on micro strip
technology. Good agreement between the experimental and
simulation results is observed.
Abstract: A SnO2/CdS/CdTe heterojunction was fabricated by
thermal evaporation technique. The fabricated cells were annealed at
573K for periods of 60, 120 and 180 minutes. The structural
properties of the solar cells have been studied by using X-ray
diffraction. Capacitance- voltage measurements were studied for the
as-prepared and annealed cells at a frequency of 102 Hz. The
capacitance- voltage measurements indicated that these cells are
abrupt. The capacitance decreases with increasing annealing time.
The zero bias depletion region width and the carrier concentration
increased with increasing annealing time. The carrier transport
mechanism for the CdS/CdTe heterojunction in dark is tunneling
recombination. The ideality factor is 1.56 and the reverse bias
saturation current is 9.6×10-10A. The energy band lineup for the n-
CdS/p-CdTe heterojunction was investigated using current - voltage
and capacitance - voltage characteristics.
Abstract: Pressure vessels are usually operating at temperatures
where the conditions of linear elastic fracture mechanics are no
longer met because massive plasticity precedes crack propagation. In
this work the development of a surface crack in a pressure vessel
subject to bending and tension under elastic-plastic fracture
mechanics conditions was investigated. Finite element analysis was
used to evaluate the hydrostatic stress, the J-integral and crack
growth for semi-elliptical surface-breaking cracks. The results
showed non-uniform stress triaxiality and crack driving force around
the crack front at large deformation levels. Different ductile crack
extensions were observed which emphasis the dependent of ductile
tearing on crack geometry and type of loading. In bending the crack
grew only beneath the surface, and growth was suppressed at the
deepest segment. This contrasts to tension where the crack breaks
through the thickness with uniform growth along the entire crack
front except at the free surface. Current investigations showed that
the crack growth developed under linear elastic fracture mechanics
conditions will no longer be applicable under ductile tearing
scenarios.
Abstract: The study aimed to verify a hypothesis that a sense of
fulfillment in student life and perceived stress in training in the
facilities could affect vocational identity among social welfare
university students, in order to acquire implications for enhancing the
vocational consciousness. A questionnaire survey was conducted with
388 third- and fourth-year students of training course for certified
social workers in three universities in A prefecture in Japan. The
questionnaire was returned by 338 students, and 288 responses
(85.2%) were valid and used for the analysis. As a SEM result, the
hypothesized model proved to be fit to the data. Path coefficient of
sense of fulfillment of student life to vocational identity was
statistically positive. Path coefficient of training stress to vocational
identity was statistically negative.
Abstract: In the study of chironomids in Armenia several
species of Orthocladiinae subfamily of Cricotopus genus,
Diamesinae subfamily of Diamesa genus, and Chironominae
subfamily of Chironomus genus, have been identified. In the
Cricotopus genus two sibling species were found, not distinguishable
by larval morphological features, but clearly distinct cytogenetically.
Abstract: Operational safety of critical systems, such as nuclear power plants, industrial chemical processes and means of transportation, is a major concern for system engineers and operators. A means to assure that is on-line safety monitors that deliver three safety tasks; fault detection and diagnosis, alarm annunciation and fault controlling. While current monitors deliver these tasks, benefits and limitations in their approaches have at the same time been highlighted. Drawing from those benefits, this paper develops a distributed monitor based on semi-independent agents, i.e. a multiagent system, and monitoring knowledge derived from a safety assessment model of the monitored system. Agents are deployed hierarchically and provided with knowledge portions and collaboration protocols to reason and integrate over the operational conditions of the components of the monitored system. The monitor aims to address limitations arising from the large-scale, complicated behaviour and distributed nature of monitored systems and deliver the aforementioned three monitoring tasks effectively.
Abstract: Most standard software development methodologies
are often not applied to software projects in many developing
countries of the world. The approach generally practice is close to
what eXtreme Programming (XP) is likely promoting, just keep
coding and testing as the requirement evolves. XP is an agile
software process development methodology that has inherent
capability for improving efficiency of Business Software
Development (BSD). XP can facilitate Business-to-Development
(B2D) relationship due to its customer-oriented advocate. From
practitioner point of view, we applied XP to BSD and result shows
that customer involvement has positive impact on productivity, but
can as well frustrate the success of the project. In an effort to
promote software engineering practice in developing countries of
Africa, we present the experiment performed, lessons learned,
problems encountered and solution adopted in applying XP
methodology to BSD.
Abstract: Tomato nutrition value, color, flavor of their fruits and products depends mainly on lycopene, β-carotene, ascorbic acid, sugars and their ratio. The two most important carotenoids in fruits of tomato are lycopene, which determined fruits red color, and β- carotene, which accounts for approximately 7% of the tomato carotenoids. Therefore, tomato products and their quality can be well characterized by the content of these elements.Maturity at harvest is very important to composition and quality of tomatoes. This is especially a problem with tomatoes picked green since it is difficult to differentiate between mature and immature-green fruits. Typical and advanced mature-green tomatoes will usually attain a much better flavor than those picked at the immature or partially mature stages.To better understand the synthesis of biochemical compounds, their concentration should be compared not only at the last stage of maturity, but also during all fruit ripening period in different varieties.