Abstract: A new nonlinear PID controller and its stability
analysis are presented in this paper. A nonlinear function is deduced
from the similarities between the control effort and the electric-field
effect of a capacitor. The conventional linear PID controller can be
modified into a nonlinear one by this function. To analyze the stability
of the nonlinear PID controlled system, an idea of energy equivalence
is adapted to avoid the conservativeness which is usually arisen from
some traditional theorems and Criterions. The energy equivalence is
naturally related with the conceptions of Passivity and T-Passivity. As
a result, an engineering guideline for the parameter design of the
nonlinear PID controller is obtained. An inverted pendulum system is
tested to verify the nonlinear PID control scheme.
Abstract: The recent advances in computational fluid dynamics
(CFD) can be useful in observing the detailed hemodynamics in
cerebral aneurysms for understanding not only their formation and
rupture but also for clinical evaluation and treatment. However,
important hemodynamic quantities are difficult to measure in vivo. In
the present study, an approximate model of normal middle cerebral
artery (MCA) along with two cases consisting broad and narrow
saccular aneurysms are analyzed. The models are generated in
ANSYS WORKBENCH and transient analysis is performed in
ANSYS-CFX. The results obtained are compared for three cases and
agree well with the available literature.
Abstract: Controlled modification of appropriate sharpness for
nanotips is of paramount importance to develop novel materials and
functional devices at a nanometer resolution. Herein, we present a
reliable and unique strategy of laser irradiation enhanced
physicochemical etching to manufacture super sharp tungsten tips
with reproducible shape and dimension as well as high yields
(~80%). The corresponding morphology structure evolution of
tungsten tips and laser-tip interaction mechanisms were
systematically investigated and discussed using field emission
scanning electron microscope (SEM) and physical optics statistics
method with different fluences under 532 nm laser irradiation. This
work paves the way for exploring more accessible metallic tips
applications with tunable apex diameter and aspect ratio, and,
furthermore, facilitates the potential sharpening enhancement
technique for other materials used in a variety of nanoscale devices.
Abstract: This research paper presents a framework on how to
build up malware dataset.Many researchers took longer time to
clean the dataset from any noise or to transform the dataset into a
format that can be used straight away for testing. Therefore, this
research is proposing a framework to help researchers to speed up
the malware dataset cleaningprocesses which later can be used for
testing. It is believed, an efficient malware dataset cleaning
processes, can improved the quality of the data, thus help to improve
the accuracy and the efficiency of the subsequent analysis. Apart
from that, an in-depth understanding of the malware taxonomy is
also important prior and during the dataset cleaning processes. A
new Trojan classification has been proposed to complement this
framework.This experiment has been conducted in a controlled lab
environment and using the dataset from VxHeavens dataset. This
framework is built based on the integration of static and dynamic
analyses, incident response method and knowledge database
discovery (KDD) processes.This framework can be used as the basis
guideline for malware researchers in building malware dataset.
Abstract: A lot of Scientific and Engineering problems require the solution of large systems of linear equations of the form bAx in an effective manner. LU-Decomposition offers good choices for solving this problem. Our approach is to find the lower bound of processing elements needed for this purpose. Here is used the so called Omega calculus, as a computational method for solving problems via their corresponding Diophantine relation. From the corresponding algorithm is formed a system of linear diophantine equalities using the domain of computation which is given by the set of lattice points inside the polyhedron. Then is run the Mathematica program DiophantineGF.m. This program calculates the generating function from which is possible to find the number of solutions to the system of Diophantine equalities, which in fact gives the lower bound for the number of processors needed for the corresponding algorithm. There is given a mathematical explanation of the problem as well. Keywordsgenerating function, lattice points in polyhedron, lower bound of processor elements, system of Diophantine equationsand : calculus.
Abstract: This paper presents an experimental case using sensory thermography to describe temperatures behavior on median nerve once an activity of repetitive motion was done. Thermography is a noninvasive technique without biological hazard and not harm at all times and has been applied in many experiments to seek for temperature patterns that help to understand diseases like cancer and cumulative trauma disorders (CTD’s). An infrared sensory thermography technology was developed to execute this study. Three women in good shape were selected for the repetitive motion tests for 4 days, two right-handed women and 1 left handed woman, two sensory thermographers were put on both median nerve wrists to get measures. The evaluation time was of 3 hours 30 minutes in a controlled temperature, 20 minutes of stabilization time at the beginning and end of the operation. Temperatures distributions are statistically evaluated and showed similar temperature patterns behavior.
Abstract: This paper introduces a technique for simulating a
single-server exponential queuing system. The technique called the
Q-Simulator is a computer program which can simulate the effect of
traffic intensity on all system average quantities given the arrival
and/or service rates. The Q-Simulator has three phases namely: the
formula based method, the uncontrolled simulation, and the
controlled simulation. The Q-Simulator generates graphs (crystal
solutions) for all results of the simulation or calculation and can be
used to estimate desirable average quantities such as waiting times,
queue lengths, etc.
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.
Abstract: Since 2005, an SRF module of CESR type serves as the
accelerating cavity at the Taiwan Light Source in the National
Synchrotron Radiation Research Center. A 500-MHz niobium cavity
is immersed in liquid helium inside this SRF module. To reduce heat
load, the liquid helium vessel is thermally shielded by
liquid-nitrogen-cooled copper layer, and the beam chambers are also
anchored with pipes of the liquid nitrogen flow in middle of the liquid
helium vessel and the vacuum vessel. A strong correlation of the
movement of the cavity-s frequency tuner with the temperature
variation of parts cooled with liquid nitrogen was observed. A
previous study on a spare SRF module with the niobium cavity cooled
by liquid nitrogen instead of liquid helium, satisfactory suppression of
the thermal oscillation was achieved by attaching a temporary buffer
tank for the vented shielding nitrogen flow from the SRF module. In
this study, a home-made buffer tank is designed and integrated to the
spare SRF module with cavity cooled by liquid helium. Design,
construction, integration, and preliminary test results of this buffer
tank are presented.
Abstract: In order to enhance the knowledge of certain
phytochemical Algerian plants that are widely used in traditional
medicine and to exploit their therapeutic potential in modern
medicine, we have done a specific extraction of terpenes and
alkaloids from the leaves of Euphorbia granulata to evaluate the
antioxidant and antibacterial activity of this extracts. After the
extraction it was found that the terpene extract gave the highest yield
59.72% compared with alkaloids extracts.
The disc diffusion method was used to determine the antibacterial
activity against different bacterial strains: Escherichia coli
(ATCC25922), Pseudomonas aeruginosa (ATCC27853) and
Staphylococcus aureus (ATCC25923). All extracts have shown
inhibition of growth bacteria. The different zones of inhibition have
varied from (7 -10 mm) according to the concentrations of extract
used.
Testing the antiradical activity on DPPH-TLC plates indicated the
presence of substances that have potent anti-free radical. As against,
the BC-TLC revealed that only terpenes extract which was reacted
positively. These results can validate the importance of Euphorbia
granulata in traditional medicine.
Abstract: This study applied the Theory of Planned Behavior
model in predicting dietary behavior among Type 2 diabetics in a
Kenyan environment. The study was conducted for three months
within the diabetic clinic at Kisii Hospital in Nyanza Province in
Kenya and adopted sequential mixed methods design combing both
qualitative and quantitative phases. Qualitative data was analyzed
using grounded theory analysis method. Structural equation modeling
using maximum likelihood was used to analyze quantitative data.
The results based on the common fit indices revealed that the theory
of planned behavior fitted the data acceptably well among the Type 2
diabetes and within dietary behavior {χ2 = 223.3, df = 77, p = .02,
χ2/df = 2.9, n=237; TLI = .93; CFI =.91; RMSEA (90CI) = .090(.039,
.146)}. This implies that the Theory of Planned Behavior holds and
forms a framework for promoting dietary practice among Type 2
diabetics.
Abstract: Though nonlinear dynamic analysis using a specialized
hydro-code such as AUTODYN is accurate and useful tool for
progressive collapse assessment of a multi-story building subjected to
blast load, it takes too much time to be applied to a practical simulation
of progressive collapse of a tall building. In this paper, blast analysis of
a RC frame structure using a simplified model with Reinforcement
Contact technique provided in Ansys Workbench was introduced and
investigated on its accuracy. Even though the simplified model has a
fraction of elements of the detailed model, the simplified model with
this modeling technique shows similar structural behavior under the
blast load to the detailed model. The proposed modeling method can
be effectively applied to blast loading progressive collapse analysis of
a RC frame structure.
Abstract: A new distance-adjusted approach is proposed in
which static square contours are defined around an estimated
symbol in a QAM constellation, which create regions that
correspond to fixed step sizes and weighting factors. As a
result, the equalizer tap adjustment consists of a linearly
weighted sum of adaptation criteria that is scaled by a variable
step size. This approach is the basis of two new algorithms: the
Variable step size Square Contour Algorithm (VSCA) and the
Variable step size Square Contour Decision-Directed
Algorithm (VSDA). The proposed schemes are compared with
existing blind equalization algorithms in the SCA family in
terms of convergence speed, constellation eye opening and
residual ISI suppression. Simulation results for 64-QAM
signaling over empirically derived microwave radio channels
confirm the efficacy of the proposed algorithms. An RTL
implementation of the blind adaptive equalizer based on the
proposed schemes is presented and the system is configured to
operate in VSCA error signal mode, for square QAM signals
up to 64-QAM.
Abstract: Electrophysiological signals were recorded from primary cultures of dissociated rat cortical neurons coupled to Micro-Electrode Arrays (MEAs). The neuronal discharge patterns may change under varying physiological and pathological conditions. For this reason, we developed a new burst detection method able to identify bursts with peculiar features in different experimental conditions (i.e. spontaneous activity and under the effect of specific drugs). The main feature of our algorithm (i.e. Burst On Hurst), based on the auto-similarity or fractal property of the recorded signal, is the independence from the chosen spike detection method since it works directly on the raw data.
Abstract: Owing to the stringent environmental legislations,
CO2 capture and sequestration is one of the viable solutions to reduce
the CO2 emissions from various sources. In this context, Ionic liquids
(ILs) are being investigated as suitable absorption media for CO2
capture. Due to their non-evaporative, non-toxic, and non-corrosive
nature, these ILs have the potential to replace the existing solvents
like aqueous amine solutions for CO2 separation technologies. Thus,
the present work aims at studying the important aspects such as the
interactions of CO2 molecule with different anions (F-, Br-, Cl-, NO3
-,
BF4
-, PF6
-, Tf2N-, and CF3SO3
-) that are commonly used in ILs
through molecular modeling. In this, the minimum energy structures
have been obtained using Ab initio based calculations at MP2
(Moller-Plesset perturbation) level. Results revealed various degrees
of distortion of CO2 molecule (from its linearity) with the anions
studied, most likely due to the Lewis acid-base interactions between
CO2 and anion. Furthermore, binding energies for the anion-CO2
complexes were also calculated. The implication of anion-CO2
interactions to the solubility of CO2 in ionic liquids is also discussed.
Abstract: South Africa is facing a crisis with not being able to produce enough graduates in the scarce skills areas to sustain economic growth. The crisis is fuelled by a school system that does not produce enough potential students with Mathematics, Accounting and Science. Since the introduction of the new school curriculum in 2008, there is no longer an option to take pure maths on a standard grade level. Instead, only two mathematical subjects are offered: pure maths (which is on par with higher grade maths) and mathematical literacy. It is compulsory to take one or the other. As a result, lees student finishes Grade 12 with pure mathematics every year. This national problem needs urgent attention if South Africa is to make any headway in critical skills development as mathematics is a gateway to scarce skills professions. Higher education institutions initiated several initiatives in an attempt to address the above, including preparatory courses, bridging programmes and extended curricula with foundation provisions. In view of the above, and government policy directives to broaden access in the scarce skills areas to increase student throughput, foundation provision was introduced for Commerce and Information Technology programmes at the Vaal Triangle Campus (VTC) of North-West University (NWU) in 2010. Students enrolling for extended programmes do not comply with the minimum prerequisites for the normal programmes. The question then arises as to whether these programmes have the intended impact? This paper reports the results of a two year longitudinal study, tracking the first year academic achievement of the two cohorts of enrolments since 2010. The results provide valuable insight into the structuring of an extended programme and its potential impact.
Abstract: This article is based on the technique which is called
Discrete Parameter Tracking (DPT). First introduced by A. A. Azab
[8] which is applicable for less order reference model. The order of
the reference model is (n-l) and n is the number of the adjustable
parameters in the physical plant.
The technique utilizes a modified gradient method [9] where the
knowledge of the exact order of the nonadaptive system is not
required, so, as to eliminate the identification problem. The
applicability of the mentioned technique (DPT) was examined
through the solution of several problems.
This article introduces the solution of a third order system with
three adjustable parameters, controlled according to second order
reference model. The adjustable parameters have great initial error
which represent condition.
Computer simulations for the solution and analysis are provided
to demonstrate the simplicity and feasibility of the technique.
Abstract: The purpose of this paper is to investigate the
durability of cement mortar in presence of Rice Husk Ash (RHA).
The strength and durability of mortar with different replacement
level (0%, 10%, 15%, 20%, 25% and 30%) of Ordinary Portland
Cement (OPC) by RHA is investigated here. RHA was
manufactured from an uncontrolled burning process. Test samples
were prepared with river sand of FM 2.73. Samples were kept in
controlled environment up to test time. The results show that
addition of RHA was shown better results for 20% replacement
level than OPC at 90 days. In durability test all samples passed for
20 cycles except 25% and 30% replacement level.
Abstract: This paper describes the two stage control using a disturbance observer and a Kalman filter. The system feedback uses the estimated state when it controls the speed. After the change-over point, its feedback uses the controlled plant output when it controls the position. To change the system continually, a change-over point has to be determined pertinently, and the controlled plant input has to be adjusted by the addition of the appropriate value. The proposed method has noise-reduction effect. It changes the system continually, even if the controlled plant identification has the error. Although the conventional method needs a speed sensor, the proposed method does not need it. The proposed method has a superior robustness compared with the conventional two stage control.
Abstract: The market transformation in Kazakhstan during the
last two decades has essentially strengthened a gap between
development of urban and rural areas. Implementation of market
institutes, transition from public financing to paid rendering of social
services, change of forms of financing of social and economic
infrastructure have led to strengthening of an economic inequality of
social groups, including growth of stratification of the city and the
village. Sociological survey of urban and rural households in Almaty
city and villages of Almaty region has been carried out within the
international research project “Livelihoods Strategies of Private
Households in Central Asia: A Rural–Urban Comparison in
Kazakhstan and Kyrgyzstan" (Germany, Kazakhstan, Kyrgyzstan).
The analysis of statistical data and results of sociological research of
urban and rural households allows us to reveal issues of territorial
development, to investigate an availability of medical, educational
and other services in the city and the village, to reveal an evaluation
urban and rural dwellers of living conditions, to compare economic
strategies of households in the city and the village.