Abstract: Discrete choice model is the most used methodology for studying traveler-s mode choice and demand. However, to calibrate the discrete choice model needs to have plenty of questionnaire survey. In this study, an aggregative model is proposed. The historical data of passenger volumes for high speed rail and domestic civil aviation are employed to calibrate and validate the model. In this study, different models are compared so as to propose the best one. From the results, systematic equations forecast better than single equation do. Models with the external variable, which is oil price, are better than models based on closed system assumption.
Abstract: Experiments have been carried out at sub-critical
Reynolds number to investigate free-to-roll motions induced by
forebody and/or wings complex flow on a 30° swept back nonslender
wings-slender body-model for static and dynamic (pitch-up)
cases. For the dynamic (pitch-up) case it has been observed that roll
amplitude decreases and lag increases with increase in pitching
speed. Decrease in roll amplitude with increase in pitch rate is
attributed to low disturbing rolling moment due to weaker interaction
between forebody and wing flow components. Asymmetric forebody
vortices dominate and control the roll motion of the model in
dynamic case when non-dimensional pitch rate ≥ 1x10-2.
Effectiveness of the active control scheme utilizing rotating nose with
artificial tip perturbation is observed to be low in the angle of attack
region where the complex flow over the wings has contributions from
both forebody and wings.
Abstract: This paper presents a real-time defect detection
algorithm for high-speed steel bar in coil. Because the target speed is
very high, proposed algorithm should process quickly the large
volumes of image for real-time processing. Therefore, defect detection
algorithm should satisfy two conflicting requirements of reducing the
processing time and improving the efficiency of defect detection. To
enhance performance of detection, edge preserving method is
suggested for noise reduction of target image. Finally, experiment
results show that the proposed algorithm guarantees the condition of
the real-time processing and accuracy of detection.
Abstract: Fractional delay FIR filters design method based on
the differential evolution algorithm is presented. Differential evolution
is an evolutionary algorithm for solving a global optimization problems in the continuous search space. In the proposed approach,
an evolutionary algorithm is used to determine the coefficients of
a fractional delay FIR filter based on the Farrow structure. Basic
differential evolution is enhanced with a restricted mating technique,
which improves the algorithm performance in terms of convergence
speed and obtained solution. Evolutionary optimization is carried out by minimizing an objective function which is based on the amplitude
response and phase delay errors. Experimental results show that the proposed algorithm leads to a reduction in the amplitude response and phase delay errors relative to those achieved with the Least-Squares
method.
Abstract: Roundabout work on the principle of circulation and
entry flows, where the maximum entry flow rates depend largely on
circulating flow bearing in mind that entry flows must give away to
circulating flows. Where an existing roundabout has a road hump
installed at the entry arm, it can be hypothesized that the kinematics
of vehicles may prevent the entry arm from achieving optimum
performance. Road humps are traffic calming devices placed across
road width solely as speed reduction mechanism. They are the
preferred traffic calming option in Malaysia and often used on single
and dual carriageway local routes. The speed limit on local routes is
30mph (50 km/hr). Road humps in their various forms achieved the
biggest mean speed reduction (based on a mean speed before traffic
calming of 30mph) of up to 10mph or 16 km/hr according to the UK
Department of Transport. The underlying aim of reduced speed
should be to achieve a 'safe' distribution of speeds which reflects the
function of the road and the impacts on the local community.
Constraining safe distribution of speeds may lead to poor drivers
timing and delayed reflex reaction that can probably cause accident.
Previous studies on road hump impact have focused mainly on speed
reduction, traffic volume, noise and vibrations, discomfort and delay
from the use of road humps. The paper is aimed at optimal entry and
circulating flow induced by road humps. Results show that
roundabout entry and circulating flow perform better in
circumstances where there is no road hump at entrance.
Abstract: The three-time-scale plant model of a wind power
generator, including a wind turbine, a flexible vertical shaft, a Variable
Inertia Flywheel (VIF) module, an Active Magnetic Bearing (AMB)
unit and the applied wind sequence, is constructed. In order to make
the wind power generator be still able to operate as the spindle speed
exceeds its rated speed, the VIF is equipped so that the spindle speed
can be appropriately slowed down once any stronger wind field is
exerted. To prevent any potential damage due to collision by shaft
against conventional bearings, the AMB unit is proposed to regulate
the shaft position deviation. By singular perturbation order-reduction
technique, a lower-order plant model can be established for the
synthesis of feedback controller. Two major system parameter
uncertainties, an additive uncertainty and a multiplicative uncertainty,
are constituted by the wind turbine and the VIF respectively.
Frequency Shaping Sliding Mode Control (FSSMC) loop is proposed
to account for these uncertainties and suppress the unmodeled
higher-order plant dynamics. At last, the efficacy of the FSSMC is
verified by intensive computer and experimental simulations for
regulation on position deviation of the shaft and counter-balance of
unpredictable wind disturbance.
Abstract: A high performance computer includes a fast
processor and millions bytes of memory. During the data processing,
huge amount of information are shuffled between the memory and
processor. Because of its small size and its effectiveness speed, cache
has become a common feature of high performance computers.
Enhancing cache performance proved to be essential in the speed up
of cache-based computers. Most enhancement approaches can be
classified as either software based or hardware controlled. The
performance of the cache is quantified in terms of hit ratio or miss
ratio. In this paper, we are optimizing the cache performance based
on enhancing the cache hit ratio. The optimum cache performance is
obtained by focusing on the cache hardware modification in the way
to make a quick rejection to the missed line's tags from the hit-or
miss comparison stage, and thus a low hit time for the wanted line in
the cache is achieved. In the proposed technique which we called
Even- Odd Tabulation (EOT), the cache lines come from the main
memory into cache are classified in two types; even line's tags and
odd line's tags depending on their Least Significant Bit (LSB). This
division is exploited by EOT technique to reject the miss match line's
tags in very low time compared to the time spent by the main
comparator in the cache, giving an optimum hitting time for the
wanted cache line. The high performance of EOT technique against
the familiar mapping technique FAM is shown in the simulated
results.
Abstract: The dynamic behaviour of a four-bar linkage driven by a velocity controlled DC motor is discussed in the paper. In particular the author presents the results obtained by means of a specifically developed software, which implements the mathematical models of all components of the system (linkage, transmission, electric motor, control devices). The use of this software enables a more efficient design approach, since it allows the designer to check, in a simple and immediate way, the dynamic behaviour of the mechanism, arising from different values of the system parameters.
Abstract: We investigate the planar quasi-septic non-analytic systems which have a center-focus equilibrium at the origin and whose angular speed is constant. The system could be changed into an analytic system by two transformations, with the help of computer algebra system MATHEMATICA, the conditions of uniform isochronous center are obtained.
Abstract: In this paper, the hardware implementation of the
RSA public-key cryptographic algorithm is presented. The RSA
cryptographic algorithm is depends on the computation of repeated
modular exponentials.
The Montgomery algorithm is used and modified to reduce
hardware resources and to achieve reasonable operating speed for
FPGA. An efficient architecture for modular multiplications based on
the array multiplier is proposed. We have implemented a RSA
cryptosystem based on Montgomery algorithm. As a result, it is
shown that proposed architecture contributes to small area and
reasonable speed.
Abstract: This paper presents a new method for the
implementation of a direct rotor flux control (DRFOC) of induction
motor (IM) drives. It is based on the rotor flux components
regulation. The d and q axis rotor flux components feed proportional
integral (PI) controllers. The outputs of which are the target stator
voltages (vdsref and vqsref). While, the synchronous speed is depicted at
the output of rotor speed controller. In order to accomplish variable
speed operation, conventional PI like controller is commonly used.
These controllers provide limited good performances over a wide
range of operations even under ideal field oriented conditions. An
alternate approach is to use the so called fuzzy logic controller. The
overall investigated system is implemented using dSpace system
based on digital signal processor (DSP). Simulation and experimental
results have been presented for a one kw IM drives to confirm the
validity of the proposed algorithms.
Abstract: Saudi Arabia in recent years has seen drastic increase
in traffic related crashes. With population of over 29 million, Saudi
Arabia is considered as a fast growing and emerging economy. The
rapid population increase and economic growth has resulted in rapid
expansion of transportation infrastructure, which has led to increase
in road crashes. Saudi Ministry of Interior reported more than 7,000
people killed and 68,000 injured in 2011 ranking Saudi Arabia to be
one of the worst worldwide in traffic safety. The traffic safety issues
in the country also result in distress to road users and cause and
economic loss exceeding 3.7 billion Euros annually. Keeping this in
view, the researchers in Saudi Arabia are investigating ways to
improve traffic safety conditions in the country. This paper presents a
multilevel approach to collect traffic safety related data required to do
traffic safety studies in the region. Two highway corridors including
King Fahd Highway 39 kilometre and Gulf Cooperation Council
Highway 42 kilometre long connecting the cities of Dammam and
Khobar were selected as a study area. Traffic data collected included
traffic counts, crash data, travel time data, and speed data. The
collected data was analysed using geographic information system to
evaluate any correlation. Further research is needed to investigate the
effectiveness of traffic safety related data when collected in a
concerted effort.
Abstract: Development of motor car safety devices has reduced
fatality rates in car accidents. Yet despite this increase in car safety,
neck injuries resulting from rear impact collisions, particularly at low
speed, remain a primary concern. In this study, FEA(Finite Element
Analysis) of seat was performed to evaluate neck injuries in rear
impact. And the FEA result was verified by comparison with the actual
test results. The dummy used in FE model and actual test is BioRID II
which is regarded suitable for rear impact collision analysis. A
threshold of the BioRID II neck injury indicators was also proposed to
upgrade seat performance in order to reduce whiplash injury. To
optimize the seat for a low-speed rear impact collision, a method was
proposed, which is multi-objective optimization idea using DOE
(Design of Experiments) results.
Abstract: This paper presents an advance in monitoring and
process control of surface roughness in CNC machine for the turning
and milling processes. An integration of the in-process monitoring
and process control of the surface roughness is proposed and
developed during the machining process by using the cutting force
ratio. The previously developed surface roughness models for turning
and milling processes of the author are adopted to predict the inprocess
surface roughness, which consist of the cutting speed, the
feed rate, the tool nose radius, the depth of cut, the rake angle, and
the cutting force ratio. The cutting force ratios obtained from the
turning and the milling are utilized to estimate the in-process surface
roughness. The dynamometers are installed on the tool turret of CNC
turning machine and the table of 5-axis machining center to monitor
the cutting forces. The in-process control of the surface roughness
has been developed and proposed to control the predicted surface
roughness. It has been proved by the cutting tests that the proposed
integration system of the in-process monitoring and the process
control can be used to check the surface roughness during the cutting
by utilizing the cutting force ratio.
Abstract: The effect of extraction solvent upon properties
of carrageenan from Eucheuma cottonii was studied. The
distilled water and KOH solution (concentration 0.1- 0.5N) were
used as the solvent. Extraction process was carried out in water
bath equipped by stirrer with constant speed of 275 rpm with a
constant ratio of seaweed weight to solvent volume ( 1:50 g/mL)
at 86oC for 45 minutes. The extract was then precipitated in 3
volume of 90% ethanol, oven dried at 60oC. Based on
experimental data, alkali significantly influenced yield and
properties of extracted carrageenan. The extracted carrageenan
was found to have essentially identical FTIR spectra to the
reference samples of kappa-carrageenan. Increasing the KOH
concentration led to carrageenan containing less sulfate content
and intrinsic viscosity. The gel strength increased along with the
increasing of KOH concentration. The decreasing of intrinsic
viscosity value indicates that a polymer degradation occurs
during alkali extraction.
Abstract: The application of a high frequency signal injection method as speed and position observer in PMSM drives has been a research focus. At present, the precision of this method is nearly good as that of ten-bit encoder. But there are some questions for estimating position polarity. Based on high frequency signal injection, this paper presents a method to compensate position polarity for permanent magnet synchronous motor (PMSM). Experiments were performed to test the effectiveness of the proposed algorithm and results present the good performance.
Abstract: The objective of this research was to study factors,
which were affected on surface roughness in high speed milling of
hardened tool steel. Material used in the experiment was tool steel JIS
SKD 61 that hardened on 60 ±2 HRC. Full factorial experimental
design was conducted on 3 factors and 3 levels (3
3
designs) with 2
replications. Factors were consisted of cutting speed, feed rate, and
depth of cut. The results showed that influenced factor affected to
surface roughness was cutting speed, feed rate and depth of cut which
showed statistical significant. Higher cutting speed would cause on
better surface quality. On the other hand, higher feed rate would cause
on poorer surface quality. Interaction of factor was found that cutting
speed and depth of cut were significantly to surface quality. The
interaction of high cutting speed associated with low depth of cut
affected to better surface quality than low cutting speed and high depth
of cut.
Abstract: The purpose of this article is to analyze economic and
political tendencies of development of integration processes with
different developing level and speed on the Eurasian space, by considering two organizations at the region – Eurasian Economic
Community and Shanghai Cooperation Organization, by considering the interests of participations in organizations of Russia and China as
a global powers and Kazakhstan as a leader among the Central Asian
countries. This article investigates what certain goals Eurasian
countries (especially Russia, Kazakhstan and China) are waiting from integration within the SCO and the EurAsEC, linking the process
with the theories of regional integration. After European debt crisis it is more topically to research the integration within the specific
region's conditions.
Abstract: Grid computing is a group of clusters connected over
high-speed networks that involves coordinating and sharing
computational power, data storage and network resources operating
across dynamic and geographically dispersed locations. Resource
management and job scheduling are critical tasks in grid computing.
Resource selection becomes challenging due to heterogeneity and
dynamic availability of resources. Job scheduling is a NP-complete
problem and different heuristics may be used to reach an optimal or
near optimal solution. This paper proposes a model for resource and
job scheduling in dynamic grid environment. The main focus is to
maximize the resource utilization and minimize processing time of
jobs. Grid resource selection strategy is based on Max Heap Tree
(MHT) that best suits for large scale application and root node of
MHT is selected for job submission. Job grouping concept is used to
maximize resource utilization for scheduling of jobs in grid
computing. Proposed resource selection model and job grouping
concept are used to enhance scalability, robustness, efficiency and
load balancing ability of the grid.
Abstract: We present a method for fast volume rendering using
graphics hardware (GPU). To our knowledge, it is the first implementation
on the GPU. Based on the Shear-Warp algorithm, our
GPU-based method provides real-time frame rates and outperforms
the CPU-based implementation. When the number of slices is not
sufficient, we add in-between slices computed by interpolation. This
improves then the quality of the rendered images. We have also
implemented the ray marching algorithm on the GPU. The results
generated by the three algorithms (CPU-based and GPU-based Shear-
Warp, GPU-based Ray Marching) for two test models has proved that
the ray marching algorithm outperforms the shear-warp methods in
terms of speed up and image quality.