Abstract: The radius-of-curvature (ROC) defines the degree of
curvature along the centerline of a roadway whereby a travelling
vehicle must follow. Roadway designs must encompass ROC in
mitigating the cost of earthwork associated with construction while
also allowing vehicles to travel at maximum allowable design speeds.
Thus, a road will tend to follow natural topography where possible,
but curvature must also be optimized to permit fast, but safe vehicle
speeds. The more severe the curvature of the road, the slower the
permissible vehicle speed. For route planning, whether for urban
settings, emergency operations, or even parcel delivery, ROC is a
necessary attribute of road arcs for computing travel time.
It is extremely rare for a geo-spatial database to contain ROC. This
paper will present a procedure and mathematical algorithm to
calculate and assign ROC to a segment pair and/or polyline.
Abstract: Rotor Flux based Model Reference Adaptive System
(RF-MRAS) is the most popularly used conventional speed
estimation scheme for sensor-less IM drives. In this scheme, the
voltage model equations are used for the reference model. This
encounters major drawbacks at low frequencies/speed which leads to
the poor performance of RF-MRAS. Replacing the reference model
using Neural Network (NN) based flux estimator provides an
alternate solution and addresses such drawbacks. This paper
identifies an NN based flux estimator using Single Neuron Cascaded
(SNC) Architecture. The proposed SNC-NN model replaces the
conventional voltage model in RF-MRAS to form a novel MRAS
scheme named as SNC-NN-MRAS. Through simulation the proposed
SNC-NN-MRAS is shown to be promising in terms of all major
issues and robustness to parameter variation. The suitability of the
proposed SNC-NN-MRAS based speed estimator and its advantages
over RF-MRAS for sensor-less induction motor drives is
comprehensively presented through extensive simulations.
Abstract: An effective approach for extracting document images from a noisy background is introduced. The entire scheme is divided into three sub- stechniques – the initial preprocessing operations for noise cluster tightening, introduction of a new thresholding method by maximizing the ratio of stan- dard deviations of the combined effect on the image to the sum of weighted classes and finally the image restoration phase by image binarization utiliz- ing the proposed optimum threshold level. The proposed method is found to be efficient compared to the existing schemes in terms of computational complexity as well as speed with better noise rejection.
Abstract: Schools today face ever-increasing demands in their attempts to ensure that students are well equipped to enter the workforce and navigate a complex world. Research indicates that computer technology can help support learning, implementation of various experiments or learning games, and that it is especially useful in developing the higher-order skills of critical thinking, observation, comprehension, implementation, comparison, analysis and active attention to activities such as research, field work, simulations and scientific inquiry. The ICT in education supports the learning procedure by enabling it to be more flexible and effective, create a rich and attractive training environment and equip the students with knowledge and potential useful for the competitive social environment in which they live. This paper presents the design, the development, and the results of the evaluation analysis of an interactive educational game which using real electric vehicles - toys (material) on a toy race track. When the game starts each student selects a specific vehicle toy. Then students are answering questionnaires in the computer. The vehicles' speed is related to the percentage of right answers in a multiple choice questionnaire (software). Every question has its own significant value depending of the different level of questionnaire. Via the developed software, each right or wrong answers in questionnaire increase or decrease the real time speed of their vehicle toys. Moreover the rate of vehicle's speed increase or decrease depends on the difficulty level of each question. The aim of the work is to attract the student’s interest in a learning process and also to improve their scores. The developed real time game was tested using independent populations of students of age groups: 8-10, 11-14, 15-18 years. Standard educational and statistical analysis tools were used for the evaluation analysis of the game. Results reveal that students using the developed real time control game scored much higher (60%) than students using a traditional simulation game on the same questionnaire. Results further indicate that student's interest in repeating the developed real time control gaming was far higher (70%) than the interest of students using a traditional simulation game.
Abstract: This paper presents a comparative study on dry and wet grinding through experimental investigation in the grinding of CSM glass fibre reinforced polymer laminates using a pink aluminium oxide wheel. Different sets of experiments were performed to study the effects of the independent grinding parameters such as grinding wheel speed, feed and depth of cut on dependent performance criteria such as cutting forces and surface finish. Experimental conditions were laid out using design of experiment central composite design. An effective coolant was sought in this study to minimise cutting forces and surface roughness for GFRP laminates grinding. Test results showed that the use of coolants reduces surface roughness, although not necessarily the cutting forces. These research findings provide useful economic machining solution in terms of optimized grinding conditions for grinding CSM GFRP.
Abstract: This paper investigates the effects of lubrication on
the quantity of heat emission of two spur gear. System with and
without lubrication effected on the quantity of heat induced on the
gear box (oil - bearings – gears). Both of lubrication and speed of
motor are affected on the performance of gears. Research investigated
the lubrication on the system with and without loading as well as the
wear of gears and bearing's conditions. Gear box investigated
includes the motor, pump, two spur gears, two shafts; speed change
used pulleys and belts. Load used equal one weight ones of gear.
Lubrication mechanism used jet system (upper and lower jet). Gear
box we used system of jet lubrication is perpendicular direction of
the contact line between two teeth. Results appeared in this work that
the lubrication is the vital parameter which is affected on the
performance and durability of gears and bearings. In macroscopic
observation, we noted that damage of bearings happened during the
absence of lubrication as well as abrasive of wear of teeth. Higher
speed of motor without lubrication increased the noise, but in the
presence of lubrication was decreased.
Abstract: The aim of this work is to present a multi-objective optimization method to find maximum efficiency kinematics for a flapping wing unmanned aerial vehicle. We restrained our study to rectangular wings with the same profile along the span and to harmonic dihedral motion. It is assumed that the birdlike aerial vehicle (whose span and surface area were fixed respectively to 1m and 0.15m2) is in horizontal mechanically balanced motion at fixed speed. We used two flight physics models to describe the vehicle aerodynamic performances, namely DeLaurier-s model, which has been used in many studies dealing with flapping wings, and the model proposed by Dae-Kwan et al. Then, a constrained multi-objective optimization of the propulsive efficiency is performed using a recent evolutionary multi-objective algorithm called є-MOEA. Firstly, we show that feasible solutions (i.e. solutions that fulfil the imposed constraints) can be obtained using Dae-Kwan et al.-s model. Secondly, we highlight that a single objective optimization approach (weighted sum method for example) can also give optimal solutions as good as the multi-objective one which nevertheless offers the advantage of directly generating the set of the best trade-offs. Finally, we show that the DeLaurier-s model does not yield feasible solutions.
Abstract: Researches on the general rules of temperature field
changing and their effects on the bridge in construction are necessary.
This paper investigated the rules of temperature field changing and its
effects on bridge using onsite measurement and computational
analysis. Guanyinsha Bridge was used as a case study in this research.
The temperature field was simulated in analyses. The effects of certain
boundary conditions such as sun radiance, wind speed, and model
parameters such as heat factor and specific heat on temperature field
are investigated. Recommended values for these parameters are
proposed. The simulated temperature field matches the measured
observations with high accuracy. At the same time, the stresses and
deflections of the bridge computed with the simulated temperature
field matches measured values too. As a conclusion, the temperature
effect analysis of reinforced concrete box girder can be conducted
directly based on the reliable weather data of the concerned area.
Abstract: A trustworthy voting process in democratic is
important that each vote is recorded with accuracy and impartiality.
The accuracy and impartiality are tallied in high rate with biometric
system. One of the sign is a fingerprint. Fingerprint recognition is
still a challenging problem, because of the distortions among the
different impression of the same finger. Because of the trustworthy of
biometric voting technologies, it may give a great effect on numbers
of voter-s participation and outcomes of the democratic process.
Hence in this study, the authors are interested in designing and
analyzing the Electronic Voting System and the participation of the
users. The system is based on the fingerprint minutiae with the
addition of person ID number. This is in order to enhance the
accuracy and speed of the voting process. The new design is analyzed
by conducting pilot election among a class of students for selecting
their representative.
Abstract: In this paper, we study statistical multiplexing of VBR
video in ATM networks. ATM promises to provide high speed realtime
multi-point to central video transmission for telemedicine
applications in rural hospitals and in emergency medical services.
Video coders are known to produce variable bit rate (VBR) signals
and the effects of aggregating these VBR signals need to be
determined in order to design a telemedicine network infrastructure
capable of carrying these signals. We first model the VBR video
signal and simulate it using a generic continuous-data autoregressive
(AR) scheme. We carry out the queueing analysis by the Fluid
Approximation Model (FAM) and the Markov Modulated Poisson
Process (MMPP). The study has shown a trade off: multiplexing
VBR signals reduces burstiness and improves resource utilization,
however, the buffer size needs to be increased with an associated
economic cost. We also show that the MMPP model and the Fluid
Approximation model fit best, respectively, the cell region and the
burst region. Therefore, a hybrid MMPP and FAM completely
characterizes the overall performance of the ATM statistical
multiplexer. The ramifications of this technology are clear: speed,
reliability (lower loss rate and jitter), and increased capacity in video
transmission for telemedicine. With migration to full IP-based
networks still a long way to achieving both high speed and high
quality of service, the proposed ATM architecture will remain of
significant use for telemedicine.
Abstract: A computer cluster is a group of tightly coupled
computers that work together closely so that in many respects they
can be viewed as though they are a single computer. The components
of a cluster are commonly, but not always, connected to each other
through fast local area networks. Clusters are usually deployed to
improve performance and/or availability over that provided by a
single computer, while typically being much more cost-effective than
single computers of comparable speed or availability. This paper
proposed the way to implement the Beowulf Cluster in order to
achieve high performance as well as high availability.
Abstract: The African Great Lakes Region refers to the zone
around lakes Victoria, Tanganyika, Albert, Edward, Kivu, and
Malawi. The main source of electricity in this region is hydropower
whose systems are generally characterized by relatively weak,
isolated power schemes, poor maintenance and technical deficiencies
with limited electricity infrastructures. Most of the hydro sources are
rain fed, and as such there is normally a deficiency of water during
the dry seasons and extended droughts. In such calamities fossil fuels
sources, in particular petroleum products and natural gas, are
normally used to rescue the situation but apart from them being nonrenewable,
they also release huge amount of green house gases to our
environment which in turn accelerates the global warming that has at
present reached an amazing stage. Wind power is ample, renewable,
widely distributed, clean, and free energy source that does not
consume or pollute water. Wind generated electricity is one of the
most practical and commercially viable option for grid quality and
utility scale electricity production. However, the main shortcoming
associated with electric wind power generation is fluctuation in its
output both in space and time. Before making a decision to establish
a wind park at a site, the wind speed features there should therefore
be known thoroughly as well as local demand or transmission
capacity. The main objective of this paper is to utilise monthly
average wind speed data collected from one prospective site within
the African Great Lakes Region to demonstrate that the available
wind power there is high enough to generate electricity. The mean
monthly values were calculated from records gathered on hourly
basis for a period of 5 years (2001 to 2005) from a site in Tanzania.
The documentations that were collected at a height of 2 m were
projected to a height of 50 m which is the standard hub height of
wind turbines. The overall monthly average wind speed was found to
be 12.11 m/s whereas June to November was established to be the
windy season as the wind speed during the session is above the
overall monthly wind speed. The available wind power density
corresponding to the overall mean monthly wind speed was evaluated
to be 1072 W/m2, a potential that is worthwhile harvesting for the
purpose of electric generation.
Abstract: Multicarrier transmission system such as Orthogonal
Frequency Division Multiplexing (OFDM) is a promising technique
for high bit rate transmission in wireless communication systems.
OFDM is a spectrally efficient modulation technique that can achieve
high speed data transmission over multipath fading channels without
the need for powerful equalization techniques. A major drawback
of OFDM is the high Peak-to-Average Power Ratio (PAPR) of the
transmit signal which can significantly impact the performance of the
power amplifier. In this paper we have compared the PAPR reduction
performance of Golay and Reed-Muller coded OFDM signal. From
our simulation it has been found that the PAPR reduction performance
of Golay coded OFDM is better than the Reed-Muller coded OFDM
signal. Moreover, for the optimum PAPR reduction performance, code
configuration for Golay and Reed-Muller codes has been identified.
Abstract: A high-linearity and high-speed current-mode sampleand-
hold circuit is designed and simulated using a 0.25μm CMOS
technology. This circuit design is based on low voltage and it utilizes
a fully differential circuit. Due to the use of only two switches the
switch related noise has been reduced. Signal - dependent -error is
completely eliminated by a new zero voltage switching technique.
The circuit has a linearity error equal to ±0.05μa, i.e. 12-bit
accuracy with a ±160 μa differential output - input signal frequency
of 5MHZ, and sampling frequency of 100 MHZ. Third
harmonic is equal to –78dB.
Abstract: Spatial understanding and the understanding of
dynamic change in the spatial structure of molecules during a
reaction is essential for designing new molecules. Knowing the
physical processes in the reactions helps to speed up the designing
process. To support the designer with the correct representation of
the designed molecule as well as showing the dynamic behavior of
the whole reacting system is the goal of our application. Our system
shows the spatial deformation of the molecules at every time interval
by minimizing the energy level of the molecules. The position and
orientation of the molecules can be intuitively controlled by
manipulating objects of the real world using Augmented Reality
techniques. Our approach has the potential to speed up the design of
new molecules and help students to understand the chemical
processes better.
Abstract: A new design approach for three-stage operational
amplifiers (op-amps) is proposed. It allows to actually implement a
symmetrical push-pull class-AB amplifier output stage for wellestablished
three-stage amplifiers using a feedforward
transconductance stage. Compared with the conventional design
practice, the proposed approach leads to a significant
improvement of the symmetry between the positive and the
negative op-amp step response, resulting in similar values of the
positive/negative settling time. The new approach proves to be very
useful in order to fully exploit the potentiality allowed by the op-amp
in terms of speed performances. Design examples in a commercial
0.35-μm CMOS prove the effectiveness of theproposed strategy.
Abstract: Exchange algorithm with constraints on magnitude and phase error separately in new way is presented in this paper. An important feature of the algorithms presented in this paper is that they allow for design constraints which often arise in practical filter design problems. Meeting required minimum stopband attenuation or a maximum deviation from the desired magnitude and phase responses in the passbands are common design constraints that can be handled by the methods proposed here. This new algorithm may have important advantages over existing technique, with respect to the speed and stability of convergence, memory requirement and low ripples.
Abstract: In this paper, some experiments of liquid dispersion flow driven by explosion in vertical plane were carried out using a liquid explosive dispersion device with film cylindrical constraints. The separated time series describing the breakup shape and dispersion process of liquid were recorded with high speed CMOS camera. The experimental results were analyzed and some essential characteristics of liquid dispersing flow are presented.
Abstract: PROFIBUS (PROcess FIeld BUS) which is defined with international standarts (IEC61158, EN50170) is the most popular fieldbus, and provides a communication between industrial applications which are located in different control environment and location in manufacturing, process and building automation. Its communication speed is from 9.6 Kbps to 12 Mbps over distances from 100 to 1200 meters, and so it is to be often necessary to interconnect them in order to break these limits. Unfortunately this interconnection raises several issues and the solutions found so far are not very satisfactory. In this paper, we propose a new solution to interconnect PROFIBUS segments, which uses a wireless MAN based on the IEEE 802.16 standard as a backbone system. Also, the solution which is described a model for internetworking unit integrates the traffic generated by PROFIBUS segments into IEEE 802.16 wireless MAN using encapsulation technique.
Abstract: This paper presents the design and layout of a two stage, high speed operational amplifiers using standard 0.35um CMOS technology. The design procedure involves designing the bias circuit, the differential input pair, and the gain stage using CAD tools. Both schematic and layout of the operational amplifier along with the comparison in the results of the two has been presented. The operational amplifier designed, has a gain of 93.51db at low frequencies. It has a gain bandwidth product of 55.07MHz, phase margin of 51.9º and a slew rate of 22v/us for a load of capacitor of 10pF.