February 2000

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142 Reads

Published by Springer Nature

Online ISSN: 2191-4281

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Print ISSN: 1319-8025

February 2000

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142 Reads

In this study a broadcast routing algorithm has been developed for
a faulty hypercube parallel processing system using cube algebra.
Without any restriction to the number of the faulty nodes, the routing
from the source node to the destination node is implemented minimally.
The developed routing algorithm has been visually simulated via the
prepared data routing simulator program. It has been observed that this
algorithm can be applied to various routing problems

January 2007

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536 Reads

A novel approach for an efficient network-on-chip using a modified Fat Tree is presented. Contention is eliminated and latency is reduced through an improved topology and router architecture. The adopted topology increases performance without a substantial increase in the routing cost. This is achieved by using an improved buffer-less, paremeterizable router architecture. The proposed router architecture is simple to implement yet can achieve the required packet collision avoidance. Simulation results that show the level of performance achieved by both the topology and the router architecture are presented. A throughput of more than 90% is achieved way above the 40-50% usually seen in other networks on chips.

January 2005

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322 Reads

In this paper, an image restoration algorithm is proposed to identify nonlinear and noncausal blur function using artificial neural networks. Image and degradation processes include both linear and nonlinear phenomena. The proposed neural network model combines an adaptive auto-associative network with a random Gaussian process, is used to restore the blurred image and blur function, simultaneously. The noisy and blurred images are modeled as nonlinear continuous associative networks, whereas autoassociative part determines the image model coefficients and the hetero-associative part determines the blur function of the image degradation process. The self-organization like structure of the proposed neural network provides the potential solution of the blind image restoration problem. The estimation and restoration are implemented by using an iterative gradient based algorithm to minimize the error function.

September 2008

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68 Reads

Quantum state swapping is required for long-distance quantum communication. Quantum state swapping protocols are based on the quantum controlled-NOT (CNOT) or similar quantum logic operations, which are very difficult to implement experimentally. Here we present a feasible scheme for the implementation of Quantum state swapping based on planar lightwave circuit (PLC) implementation of quantum CNOT gate. This quantum gate is realized by using Mach-Zehnder interferometer. By using planar lightwave circuit in implementation, the width of waveguides and the length of CNOT gate were obtained 12 micron and 2.8 cm respectively.

January 2007

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81 Reads

This paper presents an on-line testing and diagnosis approach of microcontroller. The proposed approach has been achieved through both fault masking and fault diagnosis algorithms. Concurrent testing technique through using triple modular redundancy (TMR) is required to mask the operational faults and specially tolerate the transient faults. For permanent faults and in parallel with TMR, an on-line and non-concurrent fault detection and diagnostic technique is used to locate the faulty elements. The fault detection and diagnostic technique uses a set of assembly programs that test the entire microcontroller instruction-sets called macros. The macros are able to excite all of the microcontroller functions. A macro is associated to each machine-level instruction; and composed of a few instructions, aimed at activating the target instruction with some operand values representing the macro parameters and propagates the results of its execution to an observable memory positions. A Simulation study has been done using Xilinx Foundation tool, VHDL, and an FPGA Vertix chip.

April 2009

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138 Reads

This paper presents a multiobjective differential evolution (MODE) based approach to solve the optimal power flow (OPF) problem. OPF problem has been treated as a true multiobjective constrained optimization problem. Different objective functions and different operational constraints have been considered in the problem formulation. A clustering algorithm is applied to manage the size of the Pareto set. Also, an algorithm based on fuzzy set theory is used to extract the best compromise solution. Simulation results on IEEE-30 bus test system show the effectiveness of the proposed approach in solving true multi-objective OPF and also finding well distributed Pareto solutions.

January 2007

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296 Reads

An insensitive current mode versatile first order filter section with single input and multiple outputs is realized. The realization uses two multi outputs current conveyors, only one grounded resistor and one grounded capacitor. The realized current mode section provides low-pass, high-pass and all-pass responses at different outputs without any component matching constraint. The all-pass section is then cascaded with the current mode non-inverting integrator to realize a current mode multiphase sinusoidal oscillator. Thus the realized current mode oscillator provides eight phase sinusoidal outputs with equal magnitudes. The current mode outputs are loaded with same valued resistive load to achieve the eight phase voltage mode sinusoidal outputs with equal magnitudes. All the realization were designed and simulated using PSPICE. The simulation results thus obtained, verify the theory.

July 2011

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51 Reads

Various theoretical models have been applied to evaluate the sound velocity values at 298.15 K for the ternary system of galactose
with aqueous amylase and compared with experimental values. The validity of Nomoto (NR), Van Deal-Vangeal (IMR), Impedance
dependence relation (IDR), Collision factor theory (CFT) and Nutsch-Kuhnkies (NK) methods is checked and a comparative study
of these models is made. The non-ideal behavior of the systems is explained in terms of molecular interactions of the constituents
of the mixture.
KeywordsUltrasonic velocity–Galactose–
α-Amylase–Theoretical models

March 2011

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1,073 Reads

This paper tackles the problem of payload uncertainties through polytopic system formulation and robust controller design for a 2DOF parallel manipulator. Typically, such platforms are used as a base for different payloads, e.g. satellite antenna and camera in oceangoing crafts. Traditionally, these kinds of manipulators are modeled through a time varying nonlinear model, thus providing the rationale for a nonlinear or adaptive controller. Uncertainties due to load variations present a significant challenge for robust control design. In this paper, the authors have proposed a novel and practical approach to solve the variant payload dilemma for the stabilized platform. The novelty lies in extracting different linear models with distinct load conditions using the system identification method and quantifying them into a convex hull to formulate a polytopic system. A regulator is then designed by mixed H
2/H
∞ synthesis with pole-placement constraints in a linear matrix inequality (LMI) framework to compensate output disturbances. The results are compared with a Riccati-based H
∞ loop shaping controller. It is shown through simulations and experiments that an LMI design is a better choice for achieving robustness as well as performance. The hallmark of this work is the successful testing of the control strategy on a stabilized platform with heavy asymmetric satellite antenna to reject the tides’ effect in a deep, turbulent sea.

July 2011

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123 Reads

Chromium compounds have received considerable attention because they have been used extensively in such industrial applications
as electro-plating, steelmaking, tanning of leather goods, and as corrosion inhibitors. The use of flat sheet supported liquid
membranes (FSSLMs) to remove metals from wastewaters has been actively undertaken by both the scientific and industrial communities.
The present work deals with carrier-facilitated membrane transport of Cr(VI) from acidic media across a FSSLM using the organic
extractant reagent Alamine 336. The efficiency of the membrane transport was optimized as a function of pH, diluent type,
strip phase (NaOH) concentration, feed and strip phase mixing speed, extractant type and concentration, and support type.
Various initial feed phase Cr(VI) concentrations were studied under the optimum conditions. At a 2,000ppm optimum feed phase
concentration, the FSSLM showed no significant loss in permeability and retained the same transport ability over 49 h. Under
that condition, the extraction of Cr(VI) was found to be >99% and the mass flux and permeation coefficient were calculated
using related equations as 7.35× 10−6 kg m−2 s and 7.88× 10−6 m s−1, respectively.
KeywordsCr(VI) extraction–Flat sheet supported liquid membrane (FSSLM)–Alamine 336–Tertiary amine extractants–Facilitated mass transport

July 2011

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58 Reads

The aim of this study was to obtain a description of the neutral lutetium spectrum. We calculated the radiative parameters
(wavelengths, weighted oscillator strengths and transition probabilities) for electric dipole (E1) transitions for some excited
levels in neutral lutetium (Lu I, Z = 71). Two configuration interaction methods were used: the multiconfiguration Hartree–Fock
method developed by Fischer within the Breit-Pauli relativistic framework (MCHF + BP), and Cowan’s relativistic Hartree–Fock
(HFR) method. Results obtained have been compared with each other and with other works. A discussion of these calculations
for Lu I in this study has also been in view of the MCHF + BP and HFR methods.
KeywordsRelativistic correction–Wavelength–Oscillator strength–Transition probability

August 2011

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2,384 Reads

The aim of this study was to compare the efficacy of three ASTM saturation techniques for measuring the water absorption of
concrete. The water absorption of two ordinary concretes was determined based on the cold water, boiling water and vacuum
saturation techniques. The concretes were produced with water to cement (w/c) ratios of 0.50 and 0.60 and tested at 7 and
28 days. The vacuum saturation was more effective than the cold water and boiling water saturation methods. The vacuum saturation
technique produced up to 13.1% more water absorption than the boiling water saturation method and up to 20.2% more water absorption
than the cold water saturation method. Thus the present study suggests that the vacuum saturation technique is more efficient
than both cold water and boiling water saturation methods to measure the water absorption of concrete.
KeywordsConcrete–Mixture proportions–Saturation techniques–Water absorption

July 2011

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233 Reads

Chlorins are potential photosensitizers for photodynamic therapy because of their intense absorption in the red spectral region.
In this study, the effect of pH on the absorption and fluorescence of Sn(IV) chlorin e6 dichloride trisodium salt was investigated.
Absorption, fluorescence emission and fluorescence excitation spectra of the photosensitizer were recorded at different pH
values in an analytical buffer solution with and without fetal bovine serum (FBS). In the neat buffer solution, changing the
pH resulted in small shifts in both absorption and emission spectra. The shape of the excitation spectra also changed slightly,
with shoulders almost vanishing below pH5. Also, a pronounced reduction of the fluorescence intensity was observed upon acidification.
The fluorescence intensity gradually decreased as the concentration of FBS was increased without shifting fluorescence maxima.
The absorbance of the photosensitizer in different solvents was recorded and revealed that Sn(IV) chlorin e6 is highly soluble
in polar solvents.
KeywordsSn(IV) chlorin e6–Titration curve–Acidification–Fluorescence–Absorption–Emission

July 2011

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1,088 Reads

A new method was developed for the determination of trifluoperazine hydrochloride (TFPH) at trace levels in pharmaceuticals.
This method involved formation of a TFPH-Pt(IV) complex at a specific pH, and extraction of this complex into an organic solvent.
Flame atomic absorption spectrometry was used to measure the absorbance of platinum in the complex, and indirectly determine
the concentration of TFPH. Under the optimized conditions, the linear dynamic range, detection limit, relative standard deviation
(n=5), and the recoveries of the standard addition method were 2−60μg mL−1, 0.085μg mL−1, 1.58−2.03, and 102.24 ± 0.43, respectively. The proposed method was applied to the determination of TFPH in the drug Stelazine
(5 mg of TFPH per tablet) by both direct and standard addition procedures and gave results of 4.89 and 4.88 mg of TFPH per
tablet. This method was compared statistically with the determination of TFPH by UV–Vis spectroscopy, and the difference in
the precision from these methods was insignificant at the 95% confidence level.
KeywordsTrifluoperazine hydrochloride–Platinum(IV)–Stelazine–Atomic absorption spectroscopy–Indirect method

December 2014

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162 Reads

Provisioning of quality of service (QoS) is a key issue in visible light
communication (VLC) system as well as in other wireless communication systems.
Due to the fact that QoS requirements are not as strict for all traffic types,
more calls of higher priority traffic classes can be accommodated by blocking
some more calls of lower priority traffic classes. Diverse types of high data
rate traffic are supported by existing wireless communication systems while the
resource is limited. Hence, priority based resource allocation can ensure the
service quality for the calls of important traffic class. The fixed guard
channels to prioritize any class of calls always reduce the channel
utilization. In this paper we propose a priority based dynamic channel
reservation scheme for higher priority calls that does not reduce the channel
utilization significantly. The number of reserved channels for each of the
individual traffic classes is calculated using real-time observation of the
call arrival rates of all the traffic classes. The features of the scheme allow
reduction of the call blocking probability of higher priority calls along with
the increase of the channel utilization. The proposed Markov Chain model is
expected to be very much effective for the queuing analysis especially for the
priority scheme of any number of traffic classes. The numerical results show
that the proposed scheme is able to attain reasonable call blocking probability
of higher priority calls without sacrificing channel utilization.

July 2011

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60 Reads

Bis(dibutyldithiocarbamato)metal complexes of cadmium and zinc were synthesized as precursors for growth of thin films of
cadmium sulfide (CdS) and zinc sulfide (ZnS) by aerosol-assisted chemical vapor deposition on glass substrates. The decomposition
of the precursor complexes was observed by thermogravimetric analysis, and it took place at 350–450°C with toluene used as
the solvent. The CdS and ZnS films were analyzed by X-ray powder diffraction, scanning electron microscopy and energy-dispersive
X-ray analysis. The preferred orientation of the crystallites within the films changed with respect to the deposition temperature.
The scanning electron microscopy and energy-dispersive X-ray analysis results showed the uniform distribution of CdS and ZnS
in the films, which makes them useful photoconducting materials on a structured surface.
KeywordsCadmium sulfide–Zinc sulfide–Photoconductors–Aerosol-assisted chemical vapor deposition

August 2011

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2,073 Reads

In this work, computer-aided finite element analysis to determine conditions for flashless cold forging of a connecting rod
is presented. The workpiece specifications were calculated by developing mathematical relations between the volumes of the
die cavity and workpiece. The three dimensional FE simulation was made using DEFORM-F3 V 6.0 and geometrical modeling of the
die and workpiece was performed with SOLIDWORKS 2007 4.0. The workpiece modeled was of AISI 1045 steel and the die material
was die steel (AISI D2). The aspect ratios for the bigger eye, smaller eye and column of the connecting rod were optimized
to obtain the minimum flash volume without underfilling. Three workpiece geometries were modeled: cylindrical, pre-form 1
(dumbbell shape with fillet) and pre-form 2 (dumbbell shape without fillet). Pre-form 2 was found to be the optimum workpiece
to obtain flashless forging without underfilling, while minimizing the material volume and forging load.
KeywordsCold forging–Flashless forging–Underfilling–Plastic deformation–Optimization–Connecting rod

July 2011

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69 Reads

Preserving forests and their value to us is indispensable to human life. When making forest preservation plans and managing
forests efficiently, it is necessary to use three dimensional (3D) models of the forest regions. Apart from the traditional
and photogrammetric methods used for producing these maps, the LIght Detection and Ranging (LIDAR) measurement technique with
its various advantages has been used in recent years. This paper explains the principle of the operation of the LIDAR measurement
system and discusses the determination of digital elevation models (DEM) of forest areas and their usage in 3D models. This
test study aims to convert the scattered distributed 3D datasets obtained from airborne LIDAR technology to a digital elevation
model with a regular grid format. One of the most significant aspects of this process, the interpolation method, which affects
the quality of the final product when generating the digital elevation model, is examined with respect to data density and
distribution, grid size interval and terrain type.
KeywordsLIDAR–Three dimensional modeling–Forestlands–Digital elevation model–Interpolation methods

June 2008

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71 Reads

The notion of crossed product with a coquasi-Hopf algebra H is introduced and studied. The result of such a crossed product is an algebra in the monoidal category of right H-comodules. We give necessary and sufficient conditions for two crossed products to be equivalent. Then, two structure theorems for coquasi-Hopf modules are given. First, these are relative Hopf modules over the crossed product. Second, the category of coquasi-Hopf modules is trivial, namely equivalent to the category of modules over the starting associative algebra. In deep connection with the crossed product is the notion of a cleft extension over a coquasi-Hopf algebra, introduced by the author in a previous paper. A Morita context of Hom spaces is constructed in order to explain these extensions, which are shown to be equivalent with crossed product with invertible cocycle.

May 2008

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83 Reads

By using cocycle deformation, we construct a certain class of Hopf algebras, containing the quantized enveloping algebras and their analogues, from what we call pre-Nichols algebras. Our construction generalizes in some sense the known construction by (generalized) quantum doubles, but unlike in the known situation, it saves us from difficulties in checking complicated defining relations.

March 2009

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77 Reads

We show that the equivalence between several possible characterizations of Frobenius algebras, and of symmetric Frobenius algebras, carries over from the category of vector spaces to more general monoidal categories. For Frobenius algebras, the appropriate setting is the one of rigid monoidal categories, and for symmetric Frobenius algebras it is the one of sovereign monoidal categories. We also discuss some properties of Nakayama automorphisms.

October 2011

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59 Reads

The various canonical subcategories of the category Hopf
R
of Hopf algebras over a commutative ring R, like those of (co)commutative Hopf algebras or Hopf algebras whose antipode is bijective or of order 2, are shown to be
locally presentable categories and reflective and coreflective in their respective supercategories. The reflectivity results
provided only hold for commutative von Neumann regular rings, while most of the coreflectivity results are valid over any
ring. As a consequence one gets existence of free commutative Hopf algebras over coalgebras and cofree cocommutative Hopf
algebras over algebras.
KeywordsCommutative and cocommutative Hopf algebras–Bijective antipode–Reflections and coreflections

October 2008

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50 Reads

Motivated by the study of von Neumann regular skew groups as carried out by Alfaro, Ara and del Rio in 1995 we investigate regular and biregular Hopf module algebras. If $A$ is an algebra with an action by an affine Hopf algebra $H$, then any $H$-stable left ideal of $A$ is a direct summand if and only if $A^H$ is regular and the invariance functor $(-)^H$ induces an equivalence of $A^H$-Mod to the Wisbauer category of $A$ as $A# H$-module. Analogously we show a similar statement for the biregularity of $A$ relative to $H$ where $A^H$ is replaced by $R=Z(A)\cap A^H$ using the module theory of $A$ as a module over $A\otimes A^{op} \bowtie H$ the envelopping Hopf algebroid of $A$ and $H$. We show that every two-sided $H$-stable ideal of $A$ is generated by a central $H$-invariant idempotent if and only if $R$ is regular and $A_m$ is $H$-simple for all maximal ideals $m$ of $R$. Further sufficient conditions are given for $A# H$ and $A^H$ to be regular.

May 2008

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89 Reads

In this paper, we establish the Composition-Diamond lemma for free differential algebras. As applications, we give Groebner-Shirshov bases for free Lie-differential algebra and free commutative-differential algebra, respectively.

November 2004

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49 Reads

In the last decennia two generalizations of the Hopf algebra of symmetric functions have appeared and shown themselves important, the Hopf algebra of noncommutative symmetric functions NSymm and the Hopf algebra of quasisymmetric functions QSymm. It has also become clear that it is important to understand the noncommutative versions of such important structures as Symm the Hopf algebra of symmetric functions. Not least because the right noncommmutative versions are often more beautiful than the commutaive ones (not all cluttered up with counting coefficients). NSymm and QSymm are not truly the full noncommutative generalizations. One is maximally noncommutative but cocommutative, the other is maximally non cocommutative but commutative. There is a common, selfdual generalization, the Hopf algebra of permutations of Malvenuto, Poirier, and Reutenauer (MPR). This one is, I feel, best understood as a Hopf algebra of endomorphisms. In any case, this point of view suggests vast generalizations leading to the Hopf algebras of endomorphisms and word Hopf algebras with which this paper is concerned. This point of view also sheds light on the somewhat mysterious formulas of MPR and on the question where all the extra structure (such as autoduality) comes from. The paper concludes with a few sections on the structure of MPR and the question of algebra retractions of the natural inclusion of Hopf algebras of NSymm into MPR and section of the naural projection of MPR onto QSymm.