Abstract: The electrochemical coagulation of a kaolin
suspension was investigated at the currents of 0.06, 0.12, 0.22, 0.44,
0.85 A (corresponding to 0.68, 1.36, 2.50, 5.00, 9.66 mA·cm-2,
respectively) for the contact time of 5, 10, 20, 30, and 50 min. The
TSS removal efficiency at currents of 0.06 A, 0.12 A and 0.22 A
increased with the amount of iron generated by the sacrificial anode,
while the removal efficiencies did not increase proportionally with
the amount of iron generated at the currents of 0.44 and 0.85 A,
where electroflotation was clearly observed. Zeta potential
measurement illustrated the presence of the highly positive charged
particles created by sorption of highly charged polymeric metal
hydroxyl species onto the negative surface charged kaolin particles at
both low and high applied currents. The disappearance of the
individual peaks after certain contact times indicated the attraction
between these positive and negative charged particles causing
agglomeration. It was concluded that charge neutralization of the
individual species was not the only mechanism operating in the
electrocoagulation process at any current level, but electrostatic
attraction was likely to co-operate or mainly operate.
Abstract: This paper presents an approach for the design of
fuzzy logic power system stabilizers using genetic algorithms. In the
proposed fuzzy expert system, speed deviation and its derivative
have been selected as fuzzy inputs. In this approach the parameters of
the fuzzy logic controllers have been tuned using genetic algorithm.
Incorporation of GA in the design of fuzzy logic power system
stabilizer will add an intelligent dimension to the stabilizer and
significantly reduces computational time in the design process. It is
shown in this paper that the system dynamic performance can be
improved significantly by incorporating a genetic-based searching
mechanism. To demonstrate the robustness of the genetic based
fuzzy logic power system stabilizer (GFLPSS), simulation studies on
multimachine system subjected to small perturbation and three-phase
fault have been carried out. Simulation results show the superiority
and robustness of GA based power system stabilizer as compare to
conventionally tuned controller to enhance system dynamic
performance over a wide range of operating conditions.
Abstract: Routing in mobile ad hoc networks is a challenging task because nodes are free to move randomly. In DSR like all On- Demand routing algorithms, route discovery mechanism is associated with great delay. More Clearly in DSR routing protocol to send route reply packet, when current route breaks, destination seeks a new route. In this paper we try to change route selection mechanism proactively. We also define a link stability parameter in which a stability value is assigned to each link. Given this feature, destination node can estimate stability of routes and can select the best and more stable route. Therefore we can reduce the delay and jitter of sending data packets.
Abstract: Measures of complexity and entropy have not converged to a single quantitative description of levels of organization of complex systems. The need for such a measure is increasingly necessary in all disciplines studying complex systems. To address this problem, starting from the most fundamental principle in Physics, here a new measure for quantity of organization and rate of self-organization in complex systems based on the principle of least (stationary) action is applied to a model system - the central processing unit (CPU) of computers. The quantity of organization for several generations of CPUs shows a double exponential rate of change of organization with time. The exact functional dependence has a fine, S-shaped structure, revealing some of the mechanisms of self-organization. The principle of least action helps to explain the mechanism of increase of organization through quantity accumulation and constraint and curvature minimization with an attractor, the least average sum of actions of all elements and for all motions. This approach can help describe, quantify, measure, manage, design and predict future behavior of complex systems to achieve the highest rates of self organization to improve their quality. It can be applied to other complex systems from Physics, Chemistry, Biology, Ecology, Economics, Cities, network theory and others where complex systems are present.
Abstract: In this study, we used shape memory alloys as
actuators to build a biomorphic robot which can imitate the motion of
an earthworm. The robot can be used to explore in a narrow space.
Therefore we chose shape memory alloys as actuators. Because of the
small deformation of a wire shape memory alloy, spiral shape memory
alloys are selected and installed both on the X axis and Y axis (each
axis having two shape memory alloys) to enable the biomorphic robot
to do reciprocating motion. By the mechanism we designed, the robot
can increase the distance as it moves in a duty cycle. In addition, two
shape memory alloys are added to the robot head for controlling right
and left turns. By sending pulses through the I/O card from the
controller, the signals are then amplified by a driver to heat the shape
memory alloys in order to make the SMA shrink to pull the mechanism
to move.
Abstract: Vibration characteristics of subcooled flow boiling on
thin and long structures such as a heating rod were recently
investigated by the author. The results show that the intensity of the
subcooled boiling-induced vibration (SBIV) was influenced strongly
by the conditions of the subcooling temperature, linear power density
and flow velocity. Implosive bubble formation and collapse are the
main nature of subcooled boiling, and their behaviors are the only
sources to originate from SBIV. Therefore, in order to explain the
phenomenon of SBIV, it is essential to obtain reliable information
about bubble behavior in subcooled boiling conditions. This was
investigated at different conditions of coolant subcooling
temperatures of 25 to 75°C, coolant flow velocities of 0.16 to
0.53m/s, and linear power densities of 100 to 600 W/cm. High speed
photography at 13,500 frames per second was performed at these
conditions. The results show that even at the highest subcooling
condition, the absolute majority of bubbles collapse very close to the
surface after detaching from the heating surface. Based on these
observations, a simple model of surface tension and momentum
change is introduced to offer a rough quantitative estimate of the
force exerted on the heating surface during the bubble ebullition. The
formation of a typical bubble in subcooled boiling is predicted to
exert an excitation force in the order of 10-4 N.
Abstract: Nanofluids are novel fluids that are going to have an
important role in future industrial thermal device designs. Studies are
being predominantly conducted on the mechanism of these heat
transfers. The key to this attraction is in the increase in thermal
conductivity brought about by the Nanofluids compared with the
base fluid. Different models have been proposed for calculation of
effective thermal conduction that has been gradually modified. In this
investigation effect of nanolayer structure and Brownian motion of
particles are studied and a new modified thermal conductivity model
is proposed. Temperature, concentration, nanolayer thickness and
particle size are taken as variables and their effect are studied
simultaneously on the thermal conductivity of the fluids, showing the
concentration of the nanoparticles to affect the nanolayer thickness
which also affects the Brownian motion.
Abstract: The evaluation of conversational agents or chatterbots question answering systems is a major research area that needs much attention. Before the rise of domain-oriented conversational agents based on natural language understanding and reasoning, evaluation is never a problem as information retrieval-based metrics are readily available for use. However, when chatterbots began to become more domain specific, evaluation becomes a real issue. This is especially true when understanding and reasoning is required to cater for a wider variety of questions and at the same time to achieve high quality responses. This paper discusses the inappropriateness of the existing measures for response quality evaluation and the call for new standard measures and related considerations are brought forward. As a short-term solution for evaluating response quality of conversational agents, and to demonstrate the challenges in evaluating systems of different nature, this research proposes a blackbox approach using observation, classification scheme and a scoring mechanism to assess and rank three example systems, AnswerBus, START and AINI.
Abstract: Skip cycle is a working strategy for spark ignition
engines, which allows changing the effective stroke of an engine
through skipping some of the four stroke cycles. This study proposes
a new mechanism to achieve the desired skip-cycle strategy for
internal combustion engines. The air and fuel leakage, which occurs
through the gas exchange, negatively affects the efficiency of the
engine at high speeds and loads. An absolute sealing is assured by
direct use of poppet valves, which are kept in fully closed position
during the skipped mode. All the components of the mechanism were
designed according to the real dimensions of the Anadolu Motor's
gasoline engine and modeled in 3D by means of CAD software. As
the mechanism operates in two modes, two dynamically equivalent
models are established to obtain the force and strength analysis for
critical components.
Abstract: The most common cause of power transformer failures
is mechanical defect brought about by excessive vibration, which is
formed by the combination of multiples of a frequency of 120 Hz. In
this paper, the types of mechanical exciting forces applied to the
power transformer were classified, and the mechanical damage
mechanism of the power transformer was identified using the
vibration transfer route to the machine or structure. The general
effects of 120 Hz-vibration on the enclosure, bushing, Buchholz
relay, pressure release valve and tap changer of the transformer were
also examined.
Abstract: This paper investigates the problem of sampling from transactional data streams. We introduce CFISDS as a content based sampling algorithm that works on a landmark window model of data streams and preserve more informed sample in sample space. This algorithm that work based on closed frequent itemset mining tasks, first initiate a concept lattice using initial data, then update lattice structure using an incremental mechanism.Incremental mechanism insert, update and delete nodes in/from concept lattice in batch manner. Presented algorithm extracts the final samples on demand of user. Experimental results show the accuracy of CFISDS on synthetic and real datasets, despite on CFISDS algorithm is not faster than exist sampling algorithms such as Z and DSS.
Abstract: Short message integrated distributed monitoring systems (SM-DMS) are growing rapidly in wireless communication applications in various areas, such as electromagnetic field (EMF) management, wastewater monitoring, and air pollution supervision, etc. However, delay in short messages often makes the data embedded in SM-DMS transmit unreliably. Moreover, there are few regulations dealing with this problem in SMS transmission protocols. In this study, based on the analysis of the command and data requirements in the SM-DMS, we developed a processing model for the control center to solve the delay problem in data transmission. Three components of the model: the data transmission protocol, the receiving buffer pool method, and the timer mechanism were described in detail. Discussions on adjusting the threshold parameter in the timer mechanism were presented for the adaptive performance during the runtime of the SM-DMS. This model optimized the data transmission reliability in SM-DMS, and provided a supplement to the data transmission reliability protocols at the application level.
Abstract: A rare phenomenon of SDS-induced activation of a latent protease activity associated with the purified silkworm excretory red fluorescent protein (SE-RFP) was noticed. SE-RFP aliquots incubated with SDS for different time intervals indicated that the protein undergoes an obligatory breakdown into a number of subunits which exhibit autoproteolytic (acting upon themselves) and/or heteroproteolytic (acting on other proteins) activities. A strong serine protease activity of SE-RFP subunits on Bombyx mori nucleopolyhedrovirus (BmNPV) polyhedral protein was detected by zymography technique. A complete inhibition of BmNPV infection to silkworms was observed by the oral administration assay of the SE-RFP. Here, it is proposed that the SE-RFP prevents the initial infection of BmNPV to silkworms by obliterating the polyhedral protein. This is the first report on a silkworm red fluorescent protein that exhibits a protease activity on exposure to SDS. The present studies would help in understanding the antiviral mechanism of silkworm red fluorescent proteins.
Abstract: In this paper, we propose an efficient hierarchical DNA
sequence search method to improve the search speed while the
accuracy is being kept constant. For a given query DNA sequence,
firstly, a fast local search method using histogram features is used as a
filtering mechanism before scanning the sequences in the database.
An overlapping processing is newly added to improve the robustness
of the algorithm. A large number of DNA sequences with low
similarity will be excluded for latter searching. The Smith-Waterman
algorithm is then applied to each remainder sequences. Experimental
results using GenBank sequence data show the proposed method
combining histogram information and Smith-Waterman algorithm is
more efficient for DNA sequence search.
Abstract: A new mechanism responsible for structural life
consumption due to resonant fatigue in turbine blades, or vanes, is
presented and explained. A rotating blade or vane in a gas turbine can
change its contour due to erosion and/or material build up, in any of
these instances, the surface pressure distribution occurring on the
suction and pressure sides of blades-vanes can suffer substantial
modification of their pressure and temperatures envelopes and flow
characteristics. Meanwhile, the relative rotation between the blade
and duct vane while the pressurized gas flows and the consequent
wake crossings, will induce a fluctuating thrust force or lift that will
excite the blade.
An actual totally used up set of vane-blade components in a HP
turbine power stage in a gas turbine is analyzed. The blade suffered
some material erosion mostly at the trailing edge provoking a
peculiar surface pressure envelope which evolved as the relative
position between the vane and the blade passed in front of each other.
Interestingly preliminary modal analysis for this eroded blade
indicates several natural frequencies within the aeromechanic power
spectrum, moreover, the highest frequency component is 94% of one
natural frequency indicating near resonant condition.
Independently of other simultaneously occurring fatigue cycles
(such as thermal, centrifugal stresses).
Abstract: Mobile Ad Hoc Networks (MANETs) are multi-hop
wireless networks in which all nodes cooperatively maintain network
connectivity. In such a multi-hop wireless network, every node may
be required to perform routing in order to achieve end-to-end
communication among nodes. These networks are energy constrained
as most ad hoc mobile nodes today operate with limited battery
power. Hence, it is important to minimize the energy consumption of
the entire network in order to maximize the lifetime of ad hoc
networks. In this paper, a mechanism involving the integration of
load balancing approach and transmission power control approach is
introduced to maximize the life-span of MANETs. The mechanism is
applied on Ad hoc On-demand Vector (AODV) protocol to make it
as energy aware AODV (EA_AODV). The simulation is carried out
using GloMoSim2.03 simulator. The results show that the proposed
mechanism reduces the average required transmission energy per
packet compared to the standard AODV.
Abstract: The Marangoni convective instability in a horizontal
fluid layer with the insoluble surfactant and nondeformable free
surface is investigated. The surface tension at the free surface is
linearly dependent on the temperature and concentration gradients.
At the bottom surface, the temperature conditions of uniform
temperature and uniform heat flux are considered. By linear stability
theory, the exact analytical solutions for the steady Marangoni
convection are derived and the marginal curves are plotted. The
effects of surfactant or elasticity number, Lewis number and Biot
number on the marginal Marangoni instability are assessed. The
surfactant concentration gradients and the heat transfer mechanism at
the free surface have stabilizing effects while the Lewis number
destabilizes fluid system. The fluid system with uniform temperature
condition at the bottom boundary is more stable than the fluid layer
that is subjected to uniform heat flux at the bottom boundary.
Abstract: We present here the results for a comparative study of
some techniques, available in the literature, related to the relevance
feedback mechanism in the case of a short-term learning. Only one
method among those considered here is belonging to the data mining
field which is the K-nearest neighbors algorithm (KNN) while the
rest of the methods is related purely to the information retrieval field
and they fall under the purview of the following three major axes:
Shifting query, Feature Weighting and the optimization of the
parameters of similarity metric. As a contribution, and in addition to
the comparative purpose, we propose a new version of the KNN
algorithm referred to as an incremental KNN which is distinct from
the original version in the sense that besides the influence of the
seeds, the rate of the actual target image is influenced also by the
images already rated. The results presented here have been obtained
after experiments conducted on the Wang database for one iteration
and utilizing color moments on the RGB space. This compact
descriptor, Color Moments, is adequate for the efficiency purposes
needed in the case of interactive systems. The results obtained allow
us to claim that the proposed algorithm proves good results; it even
outperforms a wide range of techniques available in the literature.
Abstract: We investigate the ZnO role in the inherent protection
of old manuscripts to protect them against environmental damaging
effect of ultraviolet radiation, pollutant gasses, mold and bacteria. In
this study a cellulosic nanocomposite of ZnO were used as protective
coating on the surface of paper fibers. This layered nanocomposite
can act as a consolidate materials too. Furthermore, to determine how
well paper works screen objects from the damaging effects, two
accelerated aging mechanisms due to light and heat are discussed.
Results show good stability of papers with nanocomposite coating.
Also, a good light stability was shown in the colored paper that
treated with this nanocomposite. Furthermore, to demonstrate the
degree of antifungal and antibacterial properties of coated papers,
papers was treated with four common molds and bacteria and the
good preventive effects of coated paper against molds and bacteria
are described.
Abstract: A Novel fuzzy neural network combining with support vector learning mechanism called support-vector-based fuzzy neural networks (SVBFNN) is proposed. The SVBFNN combine the capability of minimizing the empirical risk (training error) and expected risk (testing error) of support vector learning in high dimensional data spaces and the efficient human-like reasoning of FNN.