Abstract: This paper analyses the unsteady, two-dimensional
stagnation point flow of an incompressible viscous fluid over a flat
sheet when the flow is started impulsively from rest and at the same
time, the sheet is suddenly stretched in its own plane with a velocity
proportional to the distance from the stagnation point. The partial
differential equations governing the laminar boundary layer forced
convection flow are non-dimensionalised using semi-similar
transformations and then solved numerically using an implicit finitedifference
scheme known as the Keller-box method. Results
pertaining to the flow and heat transfer characteristics are computed
for all dimensionless time, uniformly valid in the whole spatial region
without any numerical difficulties. Analytical solutions are also
obtained for both small and large times, respectively representing the
initial unsteady and final steady state flow and heat transfer.
Numerical results indicate that the velocity ratio parameter is found
to have a significant effect on skin friction and heat transfer rate at
the surface. Furthermore, it is exposed that there is a smooth
transition from the initial unsteady state flow (small time solution) to
the final steady state (large time solution).
Abstract: High-frequency (HF) communications have been used by military organizations for more than 90 years. The opportunity of very long range communications without the need for advanced equipment makes HF a convenient and inexpensive alternative of satellite communications. Besides the advantages, voice and data transmission over HF is a challenging task, because the HF channel generally suffers from Doppler shift and spread, multi-path, cochannel interference, and many other sources of noise. In constructing an HF data modem, all these effects must be taken into account. STANAG 4539 is a NATO standard for high-speed data transmission over HF. It allows data rates up to 12800 bps over an HF channel of 3 kHz. In this work, an efficient implementation of STANAG 4539 on a single Texas Instruments- TMS320C6747 DSP chip is described. The state-of-the-art algorithms used in the receiver and the efficiency of the implementation enables real-time high-speed data / digitized voice transmission over poor HF channels.
Abstract: The objective of this research is to develop an advanced driver assistance system characterized with the functions of lane departure warning (LDW), forward collision warning (FCW) and adaptive front-lighting system (AFS). The system is mainly configured a CCD/CMOS camera to acquire the images of roadway ahead in association with the analysis made by an image-processing unit concerning the lane ahead and the preceding vehicles. The input image captured by a camera is used to recognize the lane and the preceding vehicle positions by image detection and DROI (Dynamic Range of Interesting) algorithms. Therefore, the system is able to issue real-time auditory and visual outputs of warning when a driver is departing the lane or driving too close to approach the preceding vehicle unwittingly so that the danger could be prevented from occurring. During the nighttime, in addition to the foregoing warning functions, the system is able to control the bending light of headlamp to provide an immediate light illumination when making a turn at a curved lane and adjust the level automatically to reduce the lighting interference against the oncoming vehicles driving in the opposite direction by the curvature of lane and the vanishing point estimations. The experimental results show that the integrated vehicle image system is robust to most environments such as the lane detection and preceding vehicle detection average accuracy performances are both above 90 %.
Abstract: In this paper, the main principles of text-to-speech synthesis system are presented. Associated problems which arise when developing speech synthesis system are described. Used approaches and their application in the speech synthesis systems for Azerbaijani language are shown.
Abstract: The mesoporous MoO3/γ-Al2O3 catalyst was prepared
by incipient wetness impregnation method aiming to investigate the
effect of drying method and molybdenum content on the catalyst
property and performance towards the oxidation of benzothiophene
(BT), dibenzothiophene (DBT) and 4,6-dimethyle dibenzothiophene
(4,6-DMDBT) with H2O2 for deep oxidative desulfurization of diesel
fuel. The catalyst was characterized by XRD, BET, BJH and SEM
method. The catalyst with 10wt.% and 15wt.% Mo content represent
same optimum performance for DBT and 4,6-DMDBT removal, but
a catalyst with 10wt.% Mo has higher efficiency than 15wt.% Mo for
BT conversion. The SEM images show that use of rotary evaporator
in drying step reaches a more homogenous impregnation. The
oxidation reactivity of different sulfur compounds was studied which
followed the order of DBT>4,6-DMDBT>>BT.
Abstract: We present the results of a case study aiming to assess the reflection of the tourism community in the Web and its usability to propose new ways to communicate visually. The wealth of information contained in the Web and the clear facilities to communicate personals points of view makes of the social web a new space of exploration. In this way, social web allow the sharing of information between communities with similar interests. However, the tourism community remains unexplored as is the case of the information covered in travel stories. Along the Web, we find multiples sites allowing the users to communicate their experiences and personal points of view of a particular place of the world. This cultural heritage is found in multiple documents, usually very little supplemented with photos, so they are difficult to explore due to the lack of visual information. This paper explores the possibility of analyzing travel stories to display them visually on maps and generate new knowledge such as patterns of travel routes. This way, travel narratives published in electronic formats can be very important especially to the tourism community because of the great amount of knowledge that can be extracted. Our approach is based on the use of a Geoparsing Web Service to extract geographic coordinates from travel narratives in order to draw the geo-positions and link the documents into a map image.
Abstract: Gamboge disorder (GD) or fruit damage by the yellow sap is a major problem in mangosteen. Mangosteen plants varied in the level of GD, from very low or non GD to low, moderate and high GD. However it was difficult to differentiate between GD and non GD plants because evaluation of the disorder is strongly influenced by environment. In this study we investigated the usefulness of primer designed from bioinformatics related to cell wall strength, termed as MCWS, to predict GD. Plant materials used were 28 mangosteen plants selected based on percentage of GD categorized as high, moderate, low and very low or non GD. The result showed that the specific DNA fragments were absent in the high GD accessions. The MCWS marker suggests as a novel polymorphic marker for GD in mangosteen as well as a marker for detect variability in mangosteen as apomictic plant.
Abstract: Two novel hydrodesulfurization (HDS) catalysts:
FeN4/C and FeN2/C, were prepared using an impregnation-pyrolysis
method. The two materials were investigated as catalysts for
hydrodesulfurization (HDS) and hydrodearomitization (HDA) of
model compounds. The turnover frequency of the two FeN catalysts
is comparable to (FeN4/C) or even higher (FeN2/C) than that of
MoNi/Al2O3. The FeN4/C catalyst also exhibited catalytic activity
toward HDA.
Abstract: In CMOS integrated circuit design there is a trade-off between static power consumption and technology scaling. Recently, the power density has increased due to combination of higher clock speeds, greater functional integration, and smaller process geometries. As a result static power consumption is becoming more dominant. This is a challenge for the circuit designers. However, the designers do have a few methods which they can use to reduce this static power consumption. But all of these methods have some drawbacks. In order to achieve lower static power consumption, one has to sacrifice design area and circuit performance. In this paper, we propose a new method to reduce static power in the CMOS VLSI circuit using Variable Body Biasing technique without being penalized in area requirement and circuit performance.
Abstract: Determination of wellbore problems during a
production/injection process might be evaluated thorough
temperature log analysis. Other applications of this kind of log
analysis may also include evaluation of fluid distribution analysis
along the wellbore and identification of anomalies encountered
during production/injection process. While the accuracy of such
prediction is paramount, the common method of determination of a
wellbore temperature log includes use of steady-state energy balance
equations, which hardly describe the real conditions as observed in
typical oil and gas flowing wells during production operation; and
thus increase level of uncertainties. In this study, a practical method
has been proposed through development of a simplified semianalytical
model to apply for predicting temperature profile along the
wellbore. The developed model includes an overall heat transfer
coefficient accounting all modes of heat transferring mechanism,
which has been focused on the prediction of a temperature profile as
a function of depth for the injection/production wells. The model has
been validated with the results obtained from numerical simulation.
Abstract: Purpose of this paper is two-folded. At first it explains
the major problems that are causing stagnation in brownfield
redevelopment. In addition, these problems given the context of the
present multi-actor built environment are becoming more complex to
observe. Therefore, this paper suggests also a prospective decisionmaking
approach that is the most appropriate to observe and react on
the given stagnation problems. Such an approach should be regarded
as prescriptive-interactive decision-making approach, a barely
established branch. This approach should offer models that have
prescriptive as well as an interactive component enabling them to
successfully cope with the multi-actor environment. Overall, this
paper provides up-to-date insight on the brownfield stagnation by
gradually introducing the nowadays major problems and offers a
prospective decision-making approach how these problems could be
tackled.
Abstract: Opportunistic network is a kind of Delay Tolerant Networks (DTN) where the nodes in this network come into contact with each other opportunistically and communicate wirelessly and, an end-to-end path between source and destination may have never existed, and disconnection and reconnection is common in the network. In such a network, because of the nature of opportunistic network, perhaps there is no a complete path from source to destination for most of the time and even if there is a path; the path can be very unstable and may change or break quickly. Therefore, routing is one of the main challenges in this environment and, in order to make communication possible in an opportunistic network, the intermediate nodes have to play important role in the opportunistic routing protocols. In this paper we proposed an Adaptive Fuzzy Routing in opportunistic network (AFRON). This protocol is using the simple parameters as input parameters to find the path to the destination node. Using Message Transmission Count, Message Size and Time To Live parameters as input fuzzy to increase delivery ratio and decrease the buffer consumption in the all nodes of network.
Abstract: The main aim of this paper is to develop and calibrate
an econometric model for modeling prices of long term electricity
futures contracts. The calibration of our model is performed on data
from EEX AG allowing us to capture the specific features of German
electricity market. The data sample contains several structural breaks
which have to be taken into account for modeling. We model the data
with an ARIMAX model which reveals high correlation between the
price of electricity futures contracts and prices of LT futures
contracts of fuels (namely coal, natural gas and crude oil). Besides
this, also a share price index of representative electricity companies
traded on Xetra, spread between 10Y and 1Y German bonds and
exchange rate between EUR and USD appeared to have significant
explanatory power over these futures contracts on EEX.
Abstract: We numerically study the three-dimensional
magnetohydrodynamics (MHD) stability of oscillatory natural
convection flow in a rectangular cavity, with free top surface, filled
with a liquid metal, having an aspect ratio equal to A=L/H=5, and
subjected to a transversal temperature gradient and a uniform
magnetic field oriented in x and z directions. The finite volume
method was used in order to solve the equations of continuity,
momentum, energy, and potential. The stability diagram obtained in
this study highlights the dependence of the critical value of the
Grashof number Grcrit , with the increase of the Hartmann number
Ha for two orientations of the magnetic field. This study confirms
the possibility of stabilization of a liquid metal flow in natural
convection by application of a magnetic field and shows that the
flow stability is more important when the direction of magnetic field
is longitudinal than when the direction is transversal.
Abstract: Food and fibre production in arid and semi-arid regions has emerged as one of the major challenges for various socio-economic and political reasons such as the food security and self-sufficiency. Productive use of the renewable water resources has risen on top ofthe decision-making agenda. For this reason, efficient operation and maintenance of modern irrigation and drainage schemes become part and parcel and indispensible reality in agricultural policy making arena. The aim of this paper is to investigate the complexity of operating and maintaining such schemes, mainly focussing on challenges which enhance and opportunities that impedsustainable food and fibre production. The methodology involved using secondary data complemented byroutine observations and stakeholders views on issues that influence the O&M in the Dez command area. The SPSS program was used as an analytical framework for data analysis and interpretation.Results indicate poor application efficiency in most croplands, much of which is attributed to deficient operation of conveyance and distribution canals. These in turn, are reportedly linked to inadequate maintenance of the pumping stations and hydraulic structures like turnouts,flumes and other control systems particularly in the secondary and tertiary canals. Results show that the aforementioned deficiencies have been the major impediment to establishing regular flow toward the farm gates which subsequently undermine application efficiency and tillage operationsat farm level. Results further show that accumulative impact of such deficiencies has been the major causes of poorcrop yield and quality that deem production system in these croplands uneconomic. Results further show that the present state might undermine the sustainability of agricultural system in the command area. The overall conclusion being that present water management is unlikely to be responsive to challenges that the sector faces. And in the absence of coherent measures to shift the status quo situation in favour of more productive resource use, it would be hard to fulfil the objectives of the National Economic and Socio-cultural Development Plans.
Abstract: Triglycerides and their derivatives are considered as viable alternatives for diesel fuels. Rice bran oil is used as diesel fuel. Highly viscous rice bran oil can be reduced by blending it with diesel fuel. The present research is aimed to investigate experimentally the performance, exhaust emission and combustion characteristics of a direct injection (DI) diesel engine, typically used in agricultural sector, over the entire load range when fuelled with rice bran oil and diesel fuel blends, RB10 (10% rice bran oil + 90% diesel fuel) to RB50. The performance, emission and combustion parameters of RB20 were found to be very close to neat diesel fuel (ND). The injector opening pressure (IOP) undoubtedly is of prime importance in diesel engine operation. Performance, emission and combustion characteristics with RB30 at enhanced IOPs are better than ND. Improved premixed heat release rate were noticed with RB30 when the IOP is enhanced.
Abstract: The development and application of wind power for
renewable energy has attracted growing interest in recent years. Renewable energy sources are attracting much alteration as they can
reduce both environmental damage and dependence on fossil fuels. With the growing need for sustainable energy supplies, a case is made
for decentralized, stand-alone power supplies (SAPS) as an alternative to power grids. In the era which traditional petroleum energy resource
decreasing and the green house affect significant increasing, the development and usage of regenerative resources is inevitable. Due to the contribution of the pioneers, the development of regenerative resources already has a remarkable achievement; however, in the view of economy and quantity, it is still a long road for regenerative energy
to replace traditional petroleum energy. In our prospective, in stead of
investigate larger regenerative energy equipment, it is much wiser to
think about the blind side and breakthrough of the current technique.
Abstract: Design of Converter transformer insulation is a major
challenge. The insulation of these transformers is stressed by both
AC and DC voltages. Particle contamination is one of the major
problems in insulation structures, as they generate partial discharges
leading it to major failure of insulation. Similarly corona discharges
occur in transformer insulation. This partial discharge due to particle
movement / corona formation in insulation structure under different
voltage wave shapes, are different. In the present study, UHF
technique is adopted to understand the discharge activity and could
be realized that the characteristics of UHF signal generated under
low and high fields are different. In the case of corona generated
signal, the frequency content of the UHF sensor output lies in the
range 0.3-1.2 GHz and is not much varied except for its increase in
magnitude of discharge with the increase in applied voltage. It is
realized that the current signal injected due to partial
discharges/corona is about 4ns duration measured for first one half
cycle. Wavelet technique is adopted in the present study. It allows
one to identify the frequency content present in the signal at different
instant of time. The STD-MRA analysis helps one to identify the
frequency band in which the energy content of the UHF signal is
maximum.
Abstract: Eight steel reinforced concrete beams (SRC), were
fabricated and tested under earthquake type cyclic loading. The
effectiveness of intermediate stiffeners, such as mid-span stiffener and
plastic hinge zone stiffeners, in enhancing composite action and
ductility of SRC beams was investigated. The effectiveness of
strengthened beam-to-column (SBC) and weakened beam-to-column
(WBC) connections in enhancing beam ductility was also studied. It
was found that: (1) All the specimens possessed fairly high flexural
ductility and were found adequate for structures in high seismic zones.
(2) WBC connections induced stress concentration which caused extra
damage to concrete near the flange tapering zone. This extra damage
inhibited the flexural strength development and the ductility of the
specimens with WBC connections to some extent. (3) Specimens with
SBC connections demonstrated higher flexural strength and ductility
compared to specimens with WBC connections. (4) The intermediate
stiffeners, especially combination of plastic hinge zone stiffener and
mid span stiffeners, have an obvious effect in enhancing the ductility
of the beams with SBC connection.
Abstract: Detection and recognition of the Human Body Composition and extraction their measures (width and length of human body) in images are a major issue in detecting objects and the important field in Image, Signal and Vision Computing in recent years. Finding people and extraction their features in Images are particularly important problem of object recognition, because people can have high variability in the appearance. This variability may be due to the configuration of a person (e.g., standing vs. sitting vs. jogging), the pose (e.g. frontal vs. lateral view), clothing, and variations in illumination. In this study, first, Human Body is being recognized in image then the measures of Human Body extract from the image.