Abstract: In this study, Friction Stir Processing (FSP) a recent grain refinement technique was employed to disperse micron-sized (2 *m) SiCp particles into aluminum alloy AA6063. The feasibility to fabricate bulk composites through FSP was analyzed and experiments were conducted at different traverse speeds and wider volumes of the specimens. Micro structural observation were carried out by employing optical microscopy test of the cross sections in both parallel and perpendicular to the tool traverse direction. Mechanical property including micro hardness was evaluated in detail at various regions on the specimen. The composites had an excellent bonding with aluminum alloy substrate and a significant increase of 30% in the micro hardness value of metal matrix composite (MMC) as to that of the base metal has observed. The observations clearly indicate that SiC particles were uniformly distributed within the aluminum matrix.
Abstract: This article examines the emergence and development
of the Kazakhstan species of humanism. The biggest challenge for
Kazakhstan in terms of humanism is connected with advocating
human values in parallel to promoting national interests; preserving
the continuity of traditions in various spheres of life, business and
culture. This should be a common goal for the entire society, the
main direction for a national intelligence, and a platform for the state
policy. An idea worth considering is a formation of national humanist
tradition model; the challenges are adapting people to live in the
context of new industrial and innovative economic conditions,
keeping the balance during intensive economic development of the
country, and ensuring social harmony in the society.
Abstract: A novel methodology has been used to design an
evaporator coil of a refrigerant. The methodology used is through a
complete Computer Aided Design /Computer Aided Engineering
approach, by means of a Computational Fluid Dynamic/Finite
Element Analysis model which is executed many times for the
thermal-fluid exploration of several designs' configuration by an
commercial optimizer. Hence the design is carried out automatically
by parallel computations, with an optimization package taking the
decisions rather than the design engineer. The engineer instead takes
decision regarding the physical settings and initializing of the
computational models to employ, the number and the extension of the
geometrical parameters of the coil fins and the optimization tools to
be employed. The final design of the coil geometry found to be better
than the initial design.
Abstract: In MPEG and H.26x standards, to eliminate the
temporal redundancy we use motion estimation. Given that the
motion estimation stage is very complex in terms of computational
effort, a hardware implementation on a re-configurable circuit is
crucial for the requirements of different real time multimedia
applications. In this paper, we present hardware architecture for
motion estimation based on "Full Search Block Matching" (FSBM)
algorithm. This architecture presents minimum latency, maximum
throughput, full utilization of hardware resources such as embedded
memory blocks, and combining both pipelining and parallel
processing techniques. Our design is described in VHDL language,
verified by simulation and implemented in a Stratix II
EP2S130F1020C4 FPGA circuit. The experiment result show that the
optimum operating clock frequency of the proposed design is 89MHz
which achieves 160M pixels/sec.
Abstract: Parallel programming models exist as an abstraction
of hardware and memory architectures. There are several parallel
programming models in commonly use; they are shared memory
model, thread model, message passing model, data parallel model,
hybrid model, Flynn-s models, embarrassingly parallel computations
model, pipelined computations model. These models are not specific
to a particular type of machine or memory architecture. This paper
expresses the model program for concurrent approach to data parallel
model through java programming.
Abstract: MinC plays an important role in bacterial cell division
system by inhibiting FtsZ assembly. However, the molecular
mechanism of the action is poorly understood. E. coli MinC Nterminus
domain was purified and crystallized using 1.4 M sodium
citrate pH 6.5 as a precipitant. X-ray diffraction data was collected
and processed to 2.3 Å from a native crystal. The crystal belonged to
space group P212121, with the unit cell parameters a = 52.7, b = 54.0,
c = 64.7 Å. Assuming the presence of two molecules in the
asymmetric unit, the Matthews coefficient value is 1.94 Å3 Da-1,
which corresponds to a solvent content of 36.5%. The overall
structure of MinCN is observed as a dimer form through anti-parallel
ß-strand interaction.
Abstract: Reconfigurable optical add/drop multiplexers
(ROADMs) can be classified into three categories based on their
underlying switching technologies. Category I consists of a single
large optical switch; category II is composed of a number of small
optical switches aligned in parallel; and category III has a single
optical switch and only one wavelength being added/dropped. In this
paper, to evaluate the wavelength-routing capability of ROADMs of
category-II in dynamic optical networks,the dynamic traffic models
are designed based on Bernoulli, Poisson distributions for smooth
and regular types of traffic. Through Analytical and Simulation
results, the routing power of cat-II of ROADM networks for two
traffic models are determined.
Abstract: The inherent iterative nature of product design and development poses significant challenge to reduce the product design and development time (PD). In order to shorten the time to market, organizations have adopted concurrent development where multiple specialized tasks and design activities are carried out in parallel. Iterative nature of work coupled with the overlap of activities can result in unpredictable time to completion and significant rework. Many of the products have missed the time to market window due to unanticipated or rather unplanned iteration and rework. The iterative and often overlapped processes introduce greater amounts of ambiguity in design and development, where the traditional methods and tools of project management provide less value. In this context, identifying critical metrics to understand the iteration probability is an open research area where significant contribution can be made given that iteration has been the key driver of cost and schedule risk in PD projects. Two important questions that the proposed study attempts to address are: Can we predict and identify the number of iterations in a product development flow? Can we provide managerial insights for a better control over iteration? The proposal introduces the concept of decision points and using this concept intends to develop metrics that can provide managerial insights into iteration predictability. By characterizing the product development flow as a network of decision points, the proposed research intends to delve further into iteration probability and attempts to provide more clarity.
Abstract: Long terms variation of solar insolation had been
widely studied. However, its parallel observations in short time scale
is rather lacking. This paper aims to investigate the short time scale
evolution of solar radiation spectrum (UV, PAR, and NIR bands) due
to atmospheric aerosols and water vapors. A total of 25 days of
global and diffused solar spectrum ranges from air mass 2 to 6 were
collected using ground-based spectrometer with shadowband
technique. The result shows that variation of solar radiation is the
least in UV fraction, followed by PAR and the most in NIR. Broader
variations in PAR and NIR are associated with the short time scale
fluctuations of aerosol and water vapors. The corresponding daily
evolution of UV, PAR, and NIR fractions implies that aerosol and
water vapors variation could also be responsible for the deviation
pattern in the Langley-plot analysis.
Abstract: Load balancing is the process of improving the
performance of a parallel and distributed system through a
redistribution of load among the processors [1] [5]. In this paper we
present the performance analysis of various load balancing
algorithms based on different parameters, considering two typical
load balancing approaches static and dynamic. The analysis indicates
that static and dynamic both types of algorithm can have
advancements as well as weaknesses over each other. Deciding type
of algorithm to be implemented will be based on type of parallel
applications to solve. The main purpose of this paper is to help in
design of new algorithms in future by studying the behavior of
various existing algorithms.
Abstract: The aim of this work is to determine the supersonic
nozzle profiles used in propulsion, for the launchers or embarked
with the satellites. This design has as a role firstly, to give a
important propulsion, i.e. with uniform and parallel flow at exit,
secondly to find a short length profiles without modification of the
flow in the nozzle. The first elaborate program is used to determine
the profile of divergent by using the characteristics method for an
axisymmetric flow. The second program is conceived by using the
finite volume method to determine and test the profile found
connected to a convergent.
Abstract: The effects of ethylene (C2H4) feed position and
O2/C2H4 feed molar ratio on ethylene epoxidation in a parallel
dielectric barrier discharge (DBD) were studied. The results showed
that the ethylene feed position fraction of 0.5 and the feed molar
ratio of O2/C2H4 of 0.2:1 gave the highest EO selectivity of 34.3%
and the highest EO yield of 5.28% with low power consumptions of
2.11×10-16 Ws/molecule of ethylene converted and 6.34×10-16
Ws/molecule of EO produced when the DBD system was operated
under the best conditions: an applied voltage of 19 kV, an input
frequency of 500 Hz and a total feed flow rate of 50 cm3/min. The
separate ethylene feed system provided much higher epoxidation
activity as compared to the mixed feed system which gave EO
selectivity of 15.5%, EO yield of 2.1% and the power consumption of
EO produced of 7.7×10-16 Ws/molecule.
Abstract: In this paper, parallel interface for microprocessor
trainer was implemented. A programmable parallel–port device such
as the IC 8255A is initialized for simple input or output and for
handshake input or output by choosing kinds of modes. The hardware
connections and the programs can be used to interface
microprocessor trainer and a personal computer by using IC 8255A.
The assembly programs edited on PC-s editor can be downloaded to
the trainer.
Abstract: This work aims to test the application of computational fluid dynamics (CFD) modeling to fixed bed catalytic cracking reactors. Studies of CFD with a fixed bed design commonly use a regular packing with N=2 to define bed geometry. CFD allows us to obtain a more accurate view of the fluid flow and heat transfer mechanisms present in fixed bed equipment. Naphtha was used as feedstock and the reactor length was 80cm. It is divided in three sections that catalyst bed packed in the middle section of the reactor. The reaction scheme was involved one primary reaction and 24 secondary reactions. Because of high CPU times in these simulations, parallel processing have been used. In this study the coke formation process in fixed bed and empty tube reactor was simulated and coke in these reactors are compared. In addition, the effect of steam ratio and feed flow rate on coke formation was investigated.
Abstract: Distributed Computing Systems are usually considered the most suitable model for practical solutions of many parallel algorithms. In this paper an enhanced distributed system is presented to improve the time complexity of Binary Indexed Trees (BIT). The proposed system uses multi-uniform processors with identical architectures and a specially designed distributed memory system. The analysis of this system has shown that it has reduced the time complexity of the read query to O(Log(Log(N))), and the update query to constant complexity, while the naive solution has a time complexity of O(Log(N)) for both queries. The system was implemented and simulated using VHDL and Verilog Hardware Description Languages, with xilinx ISE 10.1, as the development environment and ModelSim 6.1c, similarly as the simulation tool. The simulation has shown that the overhead resulting by the wiring and communication between the system fragments could be fairly neglected, which makes it applicable to practically reach the maximum speed up offered by the proposed model.
Abstract: The paper deals with the kinematics and automated
calculation of intermittent mechanisms with radial cams. Currently,
electronic cams are increasingly applied in the drives of working link
mechanisms. Despite a huge advantage of electronic cams in their reprogrammability
or instantaneous change of displacement diagrams,
conventional cam mechanisms have an irreplaceable role in
production and handling machines. With high frequency of working
cycle periods, the dynamic load of the proper servomotor rotor
increases and efficiency of electronic cams strongly decreases.
Though conventional intermittent mechanisms with radial cams are
representatives of fixed automation, they have distinct advantages in
their high speed (high dynamics), positional accuracy and relatively
easy manufacture. We try to remove the disadvantage of firm
displacement diagram by reducing costs for simple design and
automated calculation that leads reliably to high-quality and
inexpensive manufacture.
Abstract: Very Large and/or computationally complex optimization problems sometimes require parallel or highperformance computing for achieving a reasonable time for computation. One of the most popular and most complicate problems of this family is “Traveling Salesman Problem". In this paper we have introduced a Branch & Bound based algorithm for the solution of such complicated problems. The main focus of the algorithm is to solve the “symmetric traveling salesman problem". We reviewed some of already available algorithms and felt that there is need of new algorithm which should give optimal solution or near to the optimal solution. On the basis of the use of logarithmic sampling, it was found that the proposed algorithm produced a relatively optimal solution for the problem and results excellent performance as compared with the traditional algorithms of this series.
Abstract: In this paper, we discuss convergence of the extrapolated iterative methods for linear systems with the coefficient matrices are singular H-matrices. And we present the sufficient and necessary conditions for convergence of the extrapolated iterative methods. Moreover, we apply the results to the GMAOR methods. Finally, we give one numerical example.
Abstract: The present paper deals with the experimental and
computational study of axial collapse of the aluminum metallic shells
having combined tube-frusta geometry between two parallel plates.
Shells were having bottom two third lengths as frusta and remaining
top one third lengths as tube. Shells were compressed to recognize
their modes of collapse and associated energy absorption capability.
An axisymmetric Finite Element computational model of collapse
process is presented and analysed, using a non-linear FE code
FORGE2. Six noded isoparametric triangular elements were used to
discretize the deforming shell. The material of the shells was
idealized as rigid visco-plastic. To validate the computational model
experimental and computed results of the deformed shapes and their
corresponding load-compression and energy-compression curves
were compared. With the help of the obtained results progress of the
axisymmetric mode of collapse has been presented, analysed and
discussed.
Abstract: This paper deals with the synthesis of fuzzy controller
applied to a permanent magnet synchronous machine (PMSM) with a
guaranteed H∞ performance. To design this fuzzy controller,
nonlinear model of the PMSM is approximated by Takagi-Sugeno
fuzzy model (T-S fuzzy model), then the so-called parallel
distributed compensation (PDC) is employed. Next, we derive the
property of the H∞ norm. The latter is cast in terms of linear matrix
inequalities (LMI-s) while minimizing the H∞ norm of the transfer
function between the disturbance and the error ( ) ev T . The
experimental and simulations results were conducted on a permanent
magnet synchronous machine to illustrate the effects of the fuzzy
modelling and the controller design via the PDC.