Abstract: This paper presents the application of discrete-time
variable structure control with sliding mode based on the 'reaching
law' method for robust control of a 'simple inverted pendulum on
moving cart' - a standard nonlinear benchmark system. The
controllers designed using the above techniques are completely
insensitive to parametric uncertainty and external disturbance. The
controller design is carried out using pole placement technique to find
state feedback gain matrix , which decides the dynamic behavior
of the system during sliding mode. This is followed by feedback gain
realization using the control law which is synthesized from 'Gao-s
reaching law'. The model of a single inverted pendulum and the
discrete variable structure control controller are developed, simulated
in MATLAB-SIMULINK and results are presented. The response of
this simulation is compared with that of the discrete linear quadratic
regulator (DLQR) and the advantages of sliding mode controller over
DLQR are also presented
Abstract: The experiments were performed in a batch set up
under different concentrations of Cu (II) (0.2 g.l-1 to 0.9 g.l-1), pH (4-
6), temperatures (20oC – 40oC) with varying teak leaves powder (as
biosorbent) dosage of 0.3 g.l-1 to 0.5 g.l-1. The kinetics of interactions
were tested with pseudo first order Lagergran equation and the value
for k1 was found to be 6.909 x 10-3 min-1. The biosorption data gave
a good fit with Langmuir and Fruendlich isotherms and the Langmuir
monolayer capacity (qm) was found to be 166.78 mg. g-1. Similarly
the Freundlich adsorption capacity (Kf) was estimated as 2.49 l g-1.
The mean values of the thermodynamic parameters ΔH, ΔS, and ΔG
were -62.42 KJ. mol-1, -0.219 KJ.mol-1 K-1 and -1.747 KJ.mol-1 at
293 K from a solution containing 0.4 g l-1 of Cu(II) showing the
biosorption to be thermodynamically favourable. These results show
good potentiality of using teak leaves as a biosorbent for the removal
of Cu(II) from aqueous solutions.
Abstract: Group key management is an important functional
building block for any secure multicast architecture.
Thereby, it has been extensively studied in the literature.
In this paper we present relevant group key management
protocols. Then, we compare them against some pertinent
performance criteria.
Abstract: We successfully developed and tested a new
separation layer solving problems with unmanageable deposits inside the boilers of Zluticka Heating Plant. The deposits are mainly created
by glass-forming melts. We plotted straw ash compositions in K2OCaO-
SiO2 phase diagram and illustrated that they are in the area of low-melting eutectic points. To prevent the melting of ash and the
formation of deposits, we modified ash compositions by injecting additives into biomass fuel, and thus effectively suppressed deposits in a burner.
Abstract: During the last decade ultrafine grained (UFG) and nano-structured (NS) materials have experienced a rapid development. In this research work finite element analysis has been carried out to investigate the plastic strain distribution in equal channel angular process (ECAP). The magnitudes of Standard deviation (S. D.) and inhomogeneity index (Ci) were compared for different ECAP passes. Verification of a three-dimensional finite element model was performed with experimental tests. Finally the mechanical property including impact energy of ultrafine grained pure commercially pure Aluminum produced by severe plastic deformation method has been examined. For this aim, equal channel angular pressing die with the channel angle, outer corner angle and channel diameter of 90°, 20° and 20mm had been designed and manufactured. Commercial pure Aluminum billets were ECAPed up to four passes by route BC at the ambient temperature. The results indicated that there is a great improvement at the hardness measurement, yield strength and ultimate tensile strength after ECAP process. It is found that the magnitudes of HV reach 67HV from 21HV after the final stage of process. Also, about 330% and 285% enhancement at the YS and UTS values have been obtained after the fourth pass as compared to the as-received conditions, respectively. On the other hand, the elongation to failure and impact energy have been reduced by 23% and 50% after imposing four passes of ECAP process, respectively.
Abstract: The aim of this investigation is to study the
performance of the new generation of the PVD coated grade and to
map the influence of cutting conditions on the tool life in milling of
ADI (Austempered Ductile Iron). The results show that chipping is
the main wear mechanism which determines the tool life in dry
condition and notch wear in wet condition for this application. This
due to the different stress mechanisms and preexisting cracks in the
coating. The wear development shows clearly that the new PVD
coating (C20) has the best ability to delay the chipping growth. It
was also found that a high content of Al in the new coating (C20)
was especially favorable compared to a TiAlN multilayer with lower
Al content (C30) or CVD coating. This is due to fine grains and low
compressive stress level in the coating which increase the coating
ability to withstand the mechanical and thermal impact. It was also
found that the use of coolant decreases the tool life with 70-80%
compare to dry milling.
Abstract: A potential flow model is used to study the unsteady
flow past two airfoils in configuration, each of which is suddenly set
into motion. The airfoil bound vortices are modeled using lumped
vortex elements and the wake behind the airfoil is modeled by discrete
vortices. This consists of solving a steady state flow problem at each
time-step where unsteadiness is incorporated through the “zero normal
flow on a solid surface" boundary condition at every time instant.
Additionally, along with the “zero normal flow on a solid surface"
boundary condition Kelvin-s condition is used to compute the strength
of the latest wake vortex shed from the trailing edge of the airfoil.
Location of the wake vortices is updated at each time-step to get the
wake shape at each time instant. Results are presented to show the
effect of airfoil-airfoil interaction and airfoil-wake interaction on the
aerodynamic characteristics of each airfoil.
Abstract: Background Contact lens (CL) wear can cause
changes in blinking and corneal staining. Aims and Objectives To
determine the effects of CL materials (HEMA and SiHy) on
spontaneous blink rate, blinking patterns and corneal staining after 2
months of wear. Methods Ninety subjects in 3 groups (control,
HEMA and SiHy) were assessed at baseline and 2-months. Blink rate
was recorded using a video camera. Blinking patterns were assessed
with digital camera and slit lamp biomicroscope. Corneal staining
was graded using IER grading scale Results There were no significant
differences in all parameters at baseline. At 2 months, CL wearers
showed significant increment in average blink rate (F1.626, 47.141 =
7.250, p = 0.003; F2,58 = 6.240, p = 0.004) and corneal staining (χ2
2,
n=30 = 31.921, p < 0.001; χ2
2, n=30 = 26.909, p < 0.001). Conclusion
Blinking characteristics and corneal staining were not influence by
soft CL materials.
Abstract: This paper propose a new circuit design which
monitor total leakage current during standby mode and generates the
optimal reverse body bias voltage, by using the adaptive body bias
(ABB) technique to compensate die-to-die parameter variations.
Design details of power monitor are examined using simulation
framework in 65nm and 32nm BTPM model CMOS process.
Experimental results show the overhead of proposed circuit in terms
of its power consumption is about 10 μW for 32nm technology and
about 12 μW for 65nm technology at the same power supply voltage
as the core power supply. Moreover the results show that our
proposed circuit design is not far sensitive to the temperature
variations and also process variations. Besides, uses the simple
blocks which offer good sensitivity, high speed, the continuously
feedback loop.
Abstract: The agricultural organic farming is different from
conventional farming in a way that is aimed at providing a balanced
and constructive action in agricultural systems. With the increase in
intensive agriculture, undesirable changes were being observed in
ecosystems with irreparable damage being caused to the natural
equilibrium. This is the reason for the increasing interest in organic
farming as an environment friendly agricultural production method.
In the present work three red fruits produced in organic farming were
analyzed, namely raspberry, gooseberry and blueberry. The samples
were harvested in a local farm when at plain maturation. The results
obtained allowed to conclude that the blueberry contained higher
amounts of phenolic compounds, total tannins and total anthocyanins
than raspberry and gooseberry. Furthermore, the HPLC analysis
allowed to identify monomeric anthocyanins and phenolic acids in
the three fruits studied.
Abstract: This research uses computational linguistics, an area of study that employs a computer to process natural language, and aims at discerning the patterns that exist in declarative sentences used in technical texts. The approach is mathematical, and the focus is on instructional texts found on web pages. The technique developed by the author and named the MAYA Semantic Technique is used here and organized into four stages. In the first stage, the parts of speech in each sentence are identified. In the second stage, the subject of the sentence is determined. In the third stage, MAYA performs a frequency analysis on the remaining words to determine the verb and its object. In the fourth stage, MAYA does statistical analysis to determine the content of the web page. The advantage of the MAYA Semantic Technique lies in its use of mathematical principles to represent grammatical operations which assist processing and accuracy if performed on unambiguous text. The MAYA Semantic Technique is part of a proposed architecture for an entire web-based intelligent tutoring system. On a sample set of sentences, partial semantics derived using the MAYA Semantic Technique were approximately 80% accurate. The system currently processes technical text in one domain, namely Cµ programming. In this domain all the keywords and programming concepts are known and understood.
Abstract: Like other external sorting algorithms, the presented
algorithm is a two step algorithm including internal and external
steps. The first part of the algorithm is like the other similar
algorithms but second part of that is including a new easy
implementing method which has reduced the vast number of inputoutput
operations saliently. As decreasing processor operating time
does not have any effect on main algorithm speed, any improvement
in it should be done through decreasing the number of input-output
operations. This paper propose an easy algorithm for choose the
correct record location of the final list. This decreases the time
complexity and makes the algorithm faster.
Abstract: Protection system hidden failures have been identified as one of the main causes of system cascading collapse resulting to power system instability. In this paper, a systematic approach is presented in order to identify the probability of a system cascading collapse by taking into consideration the effect of protection system hidden failure. This includes the accurate calculation of the probability of hidden failure as it will provide significant impinge on the findings of the probability of system cascading collapse. The probability of a system cascading collapse is then used to identify the initial tripping of sensitive transmission lines which will contribute to a critical system cascading collapse. Based on the results obtained from this study, it is important to decide on the accurate value of the hidden failure probability as it will affect the probability of a system cascading collapse.
Abstract: Composite nanostructures of metal
core/semiconductor shell (Au/CdS) configuration were prepared
using organometalic method. UV-Vis spectra for the Au/CdS colloids
show initially two well separated bands, corresponding to surface
plasmon of the Au core, and the exciton of CdS shell. The absorption
of CdS shell is enhanced, while the Au plasmon band is suppressed
as the shell thickness increases. The shell sizes were estimated from
the optical spectra using the effective mass approximation model
(EMA), and compared to the sizes of the Au core and CdS shell
measured by high resolution transmission electron microscope
(HRTEM). The changes in the absorption features are discussed in
terms of gradual increase in the coupling strength of the Au core
surface plasmon and the exciton in the CdS. leading to charge
transfer and modification of electron oscillation in Au core.
Abstract: Aeration by a plunging water jet is an energetically attractive way to effect oxygen-transfer than conventional oxygenation systems. In the present study, a new type of conical shaped plunging aeration device is fabricated to generate hollow inclined ined plunging jets (jet plunge angle of π/3 ) to investigate its oxygen transfer capacity. The results suggest that the volumetric oxygen-transfer coefficient and oxygen-transfer efficiency of the conical plunging jet aerator are competitive with other types of aeration systems. Relationships of volumetric oxygen-transfer coefficient with jet power per unit volume and jet parameters are also proposed. The suggested relationships predict the volumetric oxygentransfer coefficient within a scatter of ± 15% . Further, the application of Support Vector Machines on the experimental data revealed its utility in the prediction of volumetric oxygen-transfer coefficient and development of conical plunging jet aerators.
Abstract: We describe a novel method for removing noise (in wavelet domain) of unknown variance from microarrays. The method is based on the following procedure: We apply 1) Bidimentional Discrete Wavelet Transform (DWT-2D) to the Noisy Microarray, 2) scaling and rounding to the coefficients of the highest subbands (to obtain integer and positive coefficients), 3) bit-slicing to the new highest subbands (to obtain bit-planes), 4) then we apply the Systholic Boolean Orthonormalizer Network (SBON) to the input bit-plane set and we obtain two orthonormal otput bit-plane sets (in a Boolean sense), we project a set on the other one, by means of an AND operation, and then, 5) we apply re-assembling, and, 6) rescaling. Finally, 7) we apply Inverse DWT-2D and reconstruct a microarray from the modified wavelet coefficients. Denoising results compare favorably to the most of methods in use at the moment.
Abstract: The modern world is experiencing fundamental and dynamic changes. The transformation of international relations; the end of confrontation and successive overcoming of the Cold War consequences have expanded possible international cooperation. The global nuclear conflict threat has been minimized, while a tendency to establish a unipolar world structure with the U.S. economic and power domination is growing. The current world system of international relations, apparently is secular. However, the religious beliefs of one or another nations play a certain (sometimes a key) role, both in the domestic affairs of the individual countries and in the development of bilateral ties. Political situation in Central Asia has been characterized by new factors such as international terrorism; religious extremism and radicalism; narcotrafficking and illicit arms trade of a global character immediately threaten to peace and political stability in Central Asia. The role and influence of Islamic fundamentalism is increasing; political ethnocentrism and the associated aggravation of inter-ethnic relations, the ambiguity of national interests and objectives of major geo-political groups in the Central Asian region regarding the division the political influence, emerge. This article approaches the following issues: the role of Islam in Central Asia; destabilizing factors in Central Asia; Islamic movements in Central Asia, Western Europe and the United States; the United States, Western Europe and Central Asia: religion, politics, ideology, and the US-Central Asia antiterrorism and religious extremism cooperation.
Abstract: A automatic human tracking system using mobile
agent technology is realized because a mobile agent moves in
accordance with a migration of a target person. In this paper, we
propose a method for determining the neighbor node in consideration
of the imaging range of cameras.
Abstract: Ambient hydrolysis products in moist air and
hydrolysis kinetics in argon with humidity of RH1.5% for
polycrystalline LiH powders and sintered bulks were investigated by
X-ray diffraction, Raman spectroscopy and gravimetry. The results
showed that the hydrolysis products made up a layered structure of
LiOH•H2O/LiOH/Li2O from surface of the sample to inside. In low
humid argon atmosphere, the primary hydrolysis product was Li2O
rather than LiOH. The hydrolysis kinetic curves of LiH bulks present a
paralinear shape, which could be explained by the “Layer Diffusion
Control" model. While a three-stage hydrolysis kinetic profile was
observed for LiH powders under the same experimental conditions.
The first two sections were similar to that of the bulk samples, and the
third section also presents a linear reaction kinetics but with a smaller
reaction rate compared to the second section because of a larger
exothermic effect for the hydrolysis reaction of LiH powder.
Abstract: Wireless capsule endoscopy provides real-time images in the digestive tract. Capsule images are usually low resolution and are diverse images due to travel through various regions of human body. Color information has been a primary reference in predicting abnormalities such as bleeding. Often color is not sufficient for this purpose. In this study, we took morphological shapes into account as additional, but important criterion. First, we processed gastric images in order to indentify various objects in the image. Then, we analyzed color information in the object. In this way, we could remove unnecessary information and increase the accuracy. Compared to our previous investigations, we could handle images of various degrees of brightness and improve our diagnostic algorithm.