Abstract: The effect of porous medium on the capillary instability of a cylindrical interface in the presence of axial electric field has been investigated using viscous potential flow theory. In viscous potential flow, the viscous term in Navier-Stokes equation vanishes as
vorticity is zero but viscosity is not zero. Viscosity enters through normal stress balance in the viscous potential flow theory and tangential stresses are not considered. A dispersion relation that accounts for the growth of axisymmetric waves is derived and stability is discussed theoretically as well as numerically. Stability criterion is given by critical value of applied electric field as well as critical wave number. Various graphs have been drawn to show the effect of various physical parameters such as electric field, viscosity ratio, permittivity ratio on the stability of the system. It has been observed that the axial electric field and porous medium both have stabilizing effect on the stability of the system.
Abstract: According to Hermite there exists only a finite
number of number fields having a given degree, and a given value of
the discriminant, nevertheless this number is not known generally.
The determination of a maximum number of number fields of degree
10 having a given discriminant that contain a subfield of degree 5
having a fixed class number, narrow class number and Galois group
is the purpose of this work. The constructed lists of the first
coincidences of 52 (resp. 50, 40, 48, 22, 6) nonisomorphic number
fields with same discriminant of degree 10 of signature (6,2) (resp.
(4,3), (8,1), (2,4), (0,5), (10,0)) containing a quintic field. For each
field in the lists, we indicate its discriminant, the discriminant of its
subfield, a relative polynomial generating the field over its quintic
field and its relative discriminant, the corresponding polynomial over
Q and its Galois closure are presented with concluding remarks.
Abstract: Evaluation of educational portals is an important
subject area that needs more attention from researchers. A university
that has an educational portal which is difficult to use and interact by
teachers or students or management staff can reduce the position and
reputation of the university. Therefore, it is important to have the
ability to make an evaluation of the quality of e-services the
university provide to improve them over time.
The present study evaluates the usability of the Information
Technology Faculty portal at University of Benghazi. Two evaluation
methods were used: a questionnaire-based method and an online
automated tool-based method. The first method was used to measure
the portal's external attributes of usability (Information, Content and
Organization of the portal, Navigation, Links and Accessibility,
Aesthetic and Visual Appeal, Performance and Effectiveness and
educational purpose) from users' perspectives, while the second
method was used to measure the portal's internal attributes of
usability (number and size of HTML files, number and size of images,
load time, HTML check errors, browsers compatibility problems,
number of bad and broken links), which cannot be perceived by the
users. The study showed that some of the usability aspects have been
found at the acceptable level of performance and quality, and some
others have been found otherwise. In general, it was concluded that
the usability of IT faculty educational portal generally acceptable.
Recommendations and suggestions to improve the weakness and
quality of the portal usability are presented in this study.
Abstract: Nowadays, biometrical characterizations of Artemia
cysts are used as one of the most important factors in the study of
Artemia populations and intraspecific particularity; meanwhile these
characters can be used as economical indices. For example, typically
high hatching efficiency is possible due to the small diameter of
cysts (high number per gram); therefore small diameter of cysts
show someway high quality of cysts. This study was performed
during a ten year period, including two different ecological
conditions: rainy and drought. It is important from two different
aspects because it covers alteration of A. urmiana during ten years
also its variation in the best and worst environmental situations in
which salinity increased from 173.8 ppt in 1994 to 280.8 ppt in
2003/4. In this study the biometrical raw data of Artemia urmiana
cysts at seven stations from the Urmia Lake in 1994 and their seven
identical locations at 26 studied stations in 2003/4 were reanalyzed
again and compared together. Biometrical comparison of untreated
and decapsulated cysts in each of the seven similar stations showed a
highly significant variation between 1994 and 2003/4. Based on this
study, in whole stations the untreated and decapsulated cysts from
1994 were larger than cysts of 2003/4 without any exception. But
there was no logical relationship between salinity and chorion
thickness in the Urmia Lake. With regard to PCA analyses the
stations of two different studied years certainly have been separated
with factor 1 from each other. In conclusion, the interaction between
genetic and environmental factors can determine and explain
variation in the range of cysts diameter in Artemia.
Abstract: The notions of I-vague normal groups with membership
and non-membership functions taking values in an involutary dually
residuated lattice ordered semigroup are introduced which generalize
the notions with truth values in a Boolean algebra as well as those
usual vague sets whose membership and non-membership functions
taking values in the unit interval [0, 1]. Various operations and
properties are established.
Abstract: A computational platform is presented in this
contribution. It has been designed as a virtual laboratory to be used
for exploring optimization algorithms in biological problems. This
platform is built on a blackboard-based agent architecture. As a test
case, the version of the platform presented here is devoted to the
study of protein folding, initially with a bead-like description of the
chain and with the widely used model of hydrophobic and polar
residues (HP model). Some details of the platform design are
presented along with its capabilities and also are revised some
explorations of the protein folding problems with different types of
discrete space. It is also shown the capability of the platform to
incorporate specific tools for the structural analysis of the runs in
order to understand and improve the optimization process.
Accordingly, the results obtained demonstrate that the ensemble of
computational tools into a single platform is worthwhile by itself,
since experiments developed on it can be designed to fulfill different
levels of information in a self-consistent fashion. By now, it is being
explored how an experiment design can be useful to create a
computational agent to be included within the platform. These
inclusions of designed agents –or software pieces– are useful for the
better accomplishment of the tasks to be developed by the platform.
Clearly, while the number of agents increases the new version of the
virtual laboratory thus enhances in robustness and functionality.
Abstract: There are two common types of operational research techniques, optimisation and metaheuristic methods. The latter may be defined as a sequential process that intelligently performs the exploration and exploitation adopted by natural intelligence and strong inspiration to form several iterative searches. An aim is to effectively determine near optimal solutions in a solution space. In this work, a type of metaheuristics called Ant Colonies Optimisation, ACO, inspired by a foraging behaviour of ants was adapted to find optimal solutions of eight non-linear continuous mathematical models. Under a consideration of a solution space in a specified region on each model, sub-solutions may contain global or multiple local optimum. Moreover, the algorithm has several common parameters; number of ants, moves, and iterations, which act as the algorithm-s driver. A series of computational experiments for initialising parameters were conducted through methods of Rigid Simplex, RS, and Modified Simplex, MSM. Experimental results were analysed in terms of the best so far solutions, mean and standard deviation. Finally, they stated a recommendation of proper level settings of ACO parameters for all eight functions. These parameter settings can be applied as a guideline for future uses of ACO. This is to promote an ease of use of ACO in real industrial processes. It was found that the results obtained from MSM were pretty similar to those gained from RS. However, if these results with noise standard deviations of 1 and 3 are compared, MSM will reach optimal solutions more efficiently than RS, in terms of speed of convergence.
Abstract: Simulation of the flow and sedimentation process in
the reservoir dams can be made by two methods of physical and mathematical modeling. The study area was within a region which
ranged from the Jelogir hydrometric station to the Karkheh reservoir
dam aimed at investigating the effects of stream tubes on the
GSTARS-3 model behavior. The methodologies was to run the model based on 5 stream tubes in order to observe the influence of
each scenario on longitudinal profiles, cross-section, flow velocity and bed load sediment size. Results further suggest that the use of
two stream tubes or more which result in the semi-two-dimensional
model will yield relatively closer results to the observational data
than a singular stream tube modeling. Moreover, the results of
modeling with three stream tubes shown to yield a relatively close
results with the observational data. The overall conclusion of the paper is with applying various stream tubes; it would be possible to yield a significant influence on the modeling behavior Vis-a Vis the bed load sediment size.
Abstract: Ten lactating multiparous Holstein cows were used in
a cross-over design with two dietary treatments and 28-d periods
(with 14 d as an adaptation) to study the effect of restaurant fat on
milk production and composition. Each cow was offered 14.7 kg
DM /d of the basal concentrate diet based on barley and corn (crude
protein = 17.7%, neutral detergent fiber = 23.5%, and acid detergent
fiber = 5.8% of dry matter) with free access to alfalfa. Dietary
treatments were arranged as supplying each cow with 0 (CONTROL)
or 150 g/day (RF) of restaurant fat. Supplemental RF did not
significantly (P > 0.25) affect milk yield, composition, and
composition yields, except for milk fat contents. Milk fat contents
were depressed (P < 0.05) with supplemental RF. Our results indicate
that RF could depress milk fat without affecting milk yield and that
the depression in milk fat in response to RF precedes the depression
in milk yield.
Abstract: One of the purposes of the robust method of
estimation is to reduce the influence of outliers in the data, on the
estimates. The outliers arise from gross errors or contamination from
distributions with long tails. The trimmed mean is a robust estimate.
This means that it is not sensitive to violation of distributional
assumptions of the data. It is called an adaptive estimate when the
trimming proportion is determined from the data rather than being
fixed a “priori-.
The main objective of this study is to find out the robustness
properties of the adaptive trimmed means in terms of efficiency, high
breakdown point and influence function. Specifically, it seeks to find
out the magnitude of the trimming proportion of the adaptive
trimmed mean which will yield efficient and robust estimates of the
parameter for data which follow a modified Weibull distribution with
parameter λ = 1/2 , where the trimming proportion is determined by a
ratio of two trimmed means defined as the tail length. Secondly, the
asymptotic properties of the tail length and the trimmed means are
also investigated. Finally, a comparison is made on the efficiency of
the adaptive trimmed means in terms of the standard deviation for the
trimming proportions and when these were fixed a “priori".
The asymptotic tail lengths defined as the ratio of two trimmed
means and the asymptotic variances were computed by using the
formulas derived. While the values of the standard deviations for the
derived tail lengths for data of size 40 simulated from a Weibull
distribution were computed for 100 iterations using a computer
program written in Pascal language.
The findings of the study revealed that the tail lengths of the
Weibull distribution increase in magnitudes as the trimming
proportions increase, the measure of the tail length and the adaptive
trimmed mean are asymptotically independent as the number of
observations n becomes very large or approaching infinity, the tail
length is asymptotically distributed as the ratio of two independent
normal random variables, and the asymptotic variances decrease as
the trimming proportions increase. The simulation study revealed
empirically that the standard error of the adaptive trimmed mean
using the ratio of tail lengths is relatively smaller for different values
of trimming proportions than its counterpart when the trimming
proportions were fixed a 'priori'.
Abstract: To support mobility in ATM networks, a number of
technical challenges need to be resolved. The impact of handoff
schemes in terms of service disruption, handoff latency, cost
implications and excess resources required during handoffs needs to
be addressed. In this paper, a one phase handoff and route
optimization solution using reserved PVCs between adjacent ATM
switches to reroute connections during inter-switch handoff is
studied. In the second phase, a distributed optimization process is
initiated to optimally reroute handoff connections. The main
objective is to find the optimal operating point at which to perform
optimization subject to cost constraint with the purpose of reducing
blocking probability of inter-switch handoff calls for delay tolerant
traffic. We examine the relation between the required bandwidth
resources and optimization rate. Also we calculate and study the
handoff blocking probability due to lack of bandwidth for resources
reserved to facilitate the rapid rerouting.
Abstract: The effect of time-periodic oscillations of the Rayleigh- Benard system on the heat transport in dielectric liquids is investigated by weakly nonlinear analysis. We focus on stationary convection using the slow time scale and arrive at the real Ginzburg- Landau equation. Classical fourth order Runge-kutta method is used to solve the Ginzburg-Landau equation which gives the amplitude of convection and this helps in quantifying the heat transfer in dielectric liquids in terms of the Nusselt number. The effect of electrical Rayleigh number and the amplitude of modulation on heat transport is studied.
Abstract: fibers of pure cellulose can be made from some bacteria such as acetobacter xylinum. Bacterial cellulose fibers are very pure, tens of nm across and about 0.5 micron long. The fibers are very stiff and, although nobody seems to have measured the strength of individual fibers. Their stiffness up to 70 GPa. Fundamental strengths should be at least greater than those of the best commercial polymers, but best bulk strength seems to about the same as that of steel. They can potentially be produced in industrial quantities at greatly lowered cost and water content, and with triple the yield, by a new process. This article presents a critical review of the available information on the bacterial cellulose as a biological nonwoven fabric with special emphasis on its fermentative production and applications. Characteristics of bacterial cellulose biofabric with respect to its structure and physicochemical properties are discussed. Current and potential applications of bacterial cellulose in textile, nonwoven cloth, paper, films synthetic fiber coating, food, pharmaceutical and other industries are also presented.
Abstract: The Globally Asynchronous Locally Synchronous Network on Chip (GALS NoC) is the most efficient solution that provides low latency transfers and power efficient System on Chip (SoC) interconnect. This study presents a GALS and generic NoC architecture based on a configurable router. This router integrates a sophisticated dynamic arbiter, the wormhole routing technique and can be configured in a manner that allows it to be used in many possible NoC topologies such as Mesh 2-D, Tree and Polygon architectures. This makes it possible to improve the quality of service (QoS) required by the proposed NoC. A comparative performances study of the proposed NoC architecture, Tore architecture and of the most used Mesh 2D architecture is performed. This study shows that Spidergon architecture is characterised by the lower latency and the later saturation. It is also shown that no matter what the number of used links is raised; the Links×Diameter product permitted by the Spidergon architecture remains always the lower. The only limitation of this architecture comes from it-s over cost in term of silicon area.
Abstract: Due to increased number of terrorist attacks in recent years, loads induced by explosions need to be incorporated in building designs. For safer performance of a structure, its foundation should have sufficient strength and stability. Therefore, prior to any reconstruction or rehabilitation of a building subjected to blast, it is important to examine adverse effects on the foundation caused by blast induced ground shocks. This paper evaluates the effects of a buried explosion on a pile foundation. It treats the dynamic response of the pile in saturated sand, using explicit dynamic nonlinear finite element software LS-DYNA. The blast induced wave propagation in the soil and the horizontal deformation of pile are presented and the results are discussed. Further, a parametric study is carried out to evaluate the effect of varying the explosive shape on the pile response. This information can be used to evaluate the vulnerability of piled foundations to credible blast events as well as develop guidance for their design.
Abstract: In this article, by means of examination of Bolshevists
Turkistanskie Vedomosti" newspaper and “Erikti Oylar Organi" and
“Turkistanskyi Vestnik" newspapers which had been published
during 1917-1918, the fact that “Turkistan Governorship" established
in city of Kokand in November of 1917, within the framework of
former tsarist Russia Turkistan general-governorship, was the legal
government formed as a requisition of people of Turkistan was
proved. An examination of these two newspapers providing
information regarding history of “Turkistan Autonomy" but having
opposite to each other views makes it possible to obtain valuable data
concerning history of autonomy which was inappropriately
misrepresented during Soviet period.
Abstract: In this paper, a novel approach is presented
for designing multiplier-free state-space digital filters. The
multiplier-free design is obtained by finding power-of-2 coefficients
and also quantizing the state variables to power-of-2
numbers. Expressions for the noise variance are derived for the
quantized state vector and the output of the filter. A “structuretransformation
matrix" is incorporated in these expressions. It
is shown that quantization effects can be minimized by properly
designing the structure-transformation matrix. Simulation
results are very promising and illustrate the design algorithm.
Abstract: This paper proposes a novel architecture for developing decision support systems. Unlike conventional decision support systems, the proposed architecture endeavors to reveal the decision-making process such that humans' subjectivity can be incorporated into a computerized system and, at the same time, to preserve the capability of the computerized system in processing information objectively. A number of techniques used in developing the decision support system are elaborated to make the decisionmarking process transparent. These include procedures for high dimensional data visualization, pattern classification, prediction, and evolutionary computational search. An artificial data set is first employed to compare the proposed approach with other methods. A simulated handwritten data set and a real data set on liver disease diagnosis are then employed to evaluate the efficacy of the proposed approach. The results are analyzed and discussed. The potentials of the proposed architecture as a useful decision support system are demonstrated.
Abstract: In most rule-induction algorithms, the only operator used against nominal attributes is the equality operator =. In this paper, we first propose the use of the inequality operator, ≠, in addition to the equality operator, to increase the expressiveness of induced rules. Then, we present a new method, Binary Coding, which can be used along with an arbitrary rule-induction algorithm to make use of the inequality operator without any need to change the algorithm. Experimental results suggest that the Binary Coding method is promising enough for further investigation, especially in cases where the minimum number of rules is desirable.
Abstract: Study investigates the level and extent of voluntary disclosure practice in Croatia. The research was conducted on the sample of 130 medium and large companies. Findings indicate that two thirds of the companies analyzed disclose below-average number of additional information. The explanatory analyses has shown that firm size, listing status and industrial sector significantly and positively affect the level and extent of voluntary disclosure in the annual report of Croatian companies. On the other hand, profitability and ownership structure were found statistically insignificant. Unlike previous studies, this paper deals with level of voluntary disclosure of medium and large companies, as well as companies whose shares are not listed on the organized capital market, which can be found as our contribution. Also, the research makes contribution by providing the insights into voluntary disclosure practices in Croatia, as a case of macro-oriented accounting system economy, i.e. bank oriented economy with an emerging capital market.