Abstract: A novel calibration approach that aims to reduce
ASM2d parameter subsets and decrease the model complexity is
presented. This approach does not require high computational
demand and reduces the number of modeling parameters required to
achieve the ASMs calibration by employing a sensitivity and iteration
methodology. Parameter sensitivity is a crucial factor and the
iteration methodology enables refinement of the simulation parameter
values. When completing the iteration process, parameters values are
determined in descending order of their sensitivities. The number of
iterations required is equal to the number of model parameters of the
parameter significance ranking. This approach was used for the
ASM2d model to the evaluated EBPR phosphorus removal and it was
successful. Results of the simulation provide calibration parameters.
These included YPAO, YPO4, YPHA, qPHA, qPP, μPAO, bPAO, bPP, bPHA,
KPS, YA, μAUT, bAUT, KO2 AUT, and KNH4 AUT. Those parameters were
corresponding to the experimental data available.
Abstract: As it is known, buoyancy and drag forces rule bubble's rise velocity in a liquid column. These forces are strongly dependent on fluid properties, gravity as well as equivalent's diameter. This study reports a set of bubble rising velocity experiments in a liquid column using water or glycerol. Several records of terminal velocity were obtained. The results show that bubble's rise terminal velocity is strongly dependent on dynamic viscosity effect. The data set allowed to have some terminal velocities data interval of 8.0 ? 32.9 cm/s with Reynolds number interval 1.3 -7490. The bubble's movement was recorded with a video camera. The main goal is to present an original set data and results that will be discussed based on two-phase flow's theory. It will also discussed, the prediction of terminal velocity of a single bubble in liquid, as well as the range of its applicability. In conclusion, this study presents general expressions for the determination of the terminal velocity of isolated gas bubbles of a Reynolds number range, when the fluid proprieties are known.
Abstract: This paper presents a numerical study on surface heat
transfer characteristics of laminar air flows in parallel-plate dimpled
channels. The two-dimensional numerical model is provided by
commercial code FLUENT and the results are obtained for channels
with symmetrically opposing hemi-cylindrical cavities onto both
walls for Reynolds number ranging from 1000 to 2500. The influence
of variations in relative depth of dimples (the ratio of cavity depth to
the cavity curvature diameter), the number of them and the thermophysical
properties of channel walls on heat transfer enhancement is
studied. The results are evident for existence of an optimum value for
the relative depth of dimples in which the largest wall heat flux and
average Nusselt number can be achieved. In addition, the results of
conjugation simulation indicate that the overall influence of the ratio
of wall thermal conductivity to the one of the fluid on heat transfer
rate is not much significant and can be ignored.
Abstract: In this paper we consider the problem of distributed adaptive estimation in wireless sensor networks for two different observation noise conditions. In the first case, we assume that there are some sensors with high observation noise variance (noisy sensors) in the network. In the second case, different variance for observation noise is assumed among the sensors which is more close to real scenario. In both cases, an initial estimate of each sensor-s observation noise is obtained. For the first case, we show that when there are such sensors in the network, the performance of conventional distributed adaptive estimation algorithms such as incremental distributed least mean square (IDLMS) algorithm drastically decreases. In addition, detecting and ignoring these sensors leads to a better performance in a sense of estimation. In the next step, we propose a simple algorithm to detect theses noisy sensors and modify the IDLMS algorithm to deal with noisy sensors. For the second case, we propose a new algorithm in which the step-size parameter is adjusted for each sensor according to its observation noise variance. As the simulation results show, the proposed methods outperforms the IDLMS algorithm in the same condition.
Abstract: In this paper, Neuro-Fuzzy based Fuzzy Subtractive
Clustering Method (FSCM) and Self Tuning Fuzzy PD-like
Controller (STFPDC) were used to solve non-linearity and trajectory
problems of pitch AND yaw angles of Twin Rotor MIMO system
(TRMS). The control objective is to make the beams of TRMS reach
a desired position quickly and accurately. The proposed method
could achieve control objectives with simpler controller. To simplify
the complexity of STFPDC, ANFIS based FSCM was used to
simplify the controller and improve the response. The proposed
controllers could achieve satisfactory objectives under different input
signals. Simulation results under MATLAB/Simulink® proved the
improvement of response and superiority of simplified STFPDC on
Fuzzy Logic Controller (FLC).
Abstract: This article presents a numerical study of the doublediffusive
mixed convection in a vertical channel filled with porous
medium by using non-equilibrium model. The flow is assumed
fully developed, uni-directional and steady state. The controlling
parameters are thermal Rayleigh number (RaT ), Darcy number (Da),
Forchheimer number (F), buoyancy ratio (N), inter phase heat transfer
coefficient (H), and porosity scaled thermal conductivity ratio
(γ). The Brinkman-extended non-Darcy model is considered. The
governing equations are solved by spectral collocation method. The
main emphasize is given on flow profiles as well as heat and solute
transfer rates, when two diffusive components in terms of buoyancy
ratio are in favor (against) of each other and solid matrix and fluid
are thermally non-equilibrium. The results show that, for aiding flow
(RaT = 1000), the heat transfer rate of fluid (Nuf ) increases upto a
certain value of H, beyond that decreases smoothly and converges
to a constant, whereas in case of opposing flow (RaT = -1000),
the result is same for N = 0 and 1. The variation of Nuf in (N,
Nuf )-plane shows sinusoidal pattern for RaT = -1000. For both cases
(aiding and opposing) the flow destabilize on increasing N by inviting
point of inflection or flow separation on the velocity profile. Overall,
the buoyancy force have significant impact on the non-Darcy mixed
convection under LTNE conditions.
Abstract: Virtual Reality Modelling Language (VRML) is description language, which belongs to a field Window on World virtual reality system. The file, which is in VRML format, can be interpreted by VRML explorer in three-dimensional scene. VRML was created with aim to represent virtual reality on Internet easier. Development of 3D graphic is connected with Silicon Graphic Corporation. VRML 2.0 is the file format for describing interactive 3D scenes and objects. It can be used in collaboration with www, can be used for 3D complex representations creating of scenes, products or VR applications VRML 2.0 enables represent static and animated objects too. Interesting application of VRML is in area of manufacturing systems presentation.
Abstract: The purpose of this study was to examine a broader range of sport constraints perceived by young Koreans in Australia who may need to adjust to changing behavioral expectations due to the socio-cultural transitions. Regardless of gender, in terms of quantitative findings, the most important participation constraints within the seven categories were resources, access, interpersonal, affective, religious, socio-cultural, and physical in that order. The most important constraining items were a lack of time, access, information, adaptive skills, and parental and family support in that order. Qualitative research found young Korean’s participation constraints among three categories (time, parental control and interpersonal constraints). It is possible that different ethnic groups would be constrained by different factors; however, this is outside the scope of this study.
Abstract: The nature of wireless ad hoc and sensor networks
make them very attractive to attackers. One of the most popular and
serious attacks in wireless ad hoc networks is wormhole attack and
most proposed protocols to defend against this attack used
positioning devices, synchronized clocks, or directional antennas.
This paper analyzes the nature of wormhole attack and existing
methods of defending mechanism and then proposes round trip time
(RTT) and neighbor numbers based wormhole detection mechanism.
The consideration of proposed mechanism is the RTT between two
successive nodes and those nodes- neighbor number which is needed
to compare those values of other successive nodes. The identification
of wormhole attacks is based on the two faces. The first consideration
is that the transmission time between two wormhole attack affected
nodes is considerable higher than that between two normal neighbor
nodes. The second detection mechanism is based on the fact that by
introducing new links into the network, the adversary increases the
number of neighbors of the nodes within its radius. This system does
not require any specific hardware, has good performance and little
overhead and also does not consume extra energy. The proposed
system is designed in ad hoc on-demand distance vector (AODV)
routing protocol and analysis and simulations of the proposed system
are performed in network simulator (ns-2).
Abstract: Data rate, tolerable bit error rate or frame error rate
and range & coverage are the key performance requirement of a
communication link. In this paper performance of MFSK link is
analyzed in terms of bit error rate, number of errors and total number
of data processed. In the communication link model proposed, which
is implemented using MATLAB block set, an improvement in BER
is observed. Different parameters which effects and enables to keep
BER low in M-ary communication system are also identified.
Abstract: A unique combination of adsorption and
electrochemical regeneration with a proprietary adsorbent material
called Nyex 100 was introduced at the University of Manchester for
waste water treatment applications. Nyex 100 is based on graphite
intercalation compound. It is non porous and electrically conducing
adsorbent material. This material exhibited very small BET surface
area i.e. 2.75 m2g-1, in consequence, small adsorptive capacities for
the adsorption of various organic pollutants were obtained. This work
aims to develop composite adsorbent material essentially capable of
electrochemical regeneration coupled with improved adsorption
characteristics. An organic dye, acid violet 17 was used as standard
organic pollutant. The developed composite material was
successfully electrochemically regenerated using a DC current of 1 A
for 60 minutes. Regeneration efficiency was maintained at around
100% for five adsorption-regeneration cycles.
Abstract: This paper deals with a periodic-review substitutable
inventory system for a finite and an infinite number of periods. Here
an upward substitution structure, a substitution of a more costly item
by a less costly one, is assumed, with two products. At the beginning
of each period, a stochastic demand comes for the first item only,
which is quality-wise better and hence costlier. Whenever an arriving
demand finds zero inventory of this product, a fraction of unsatisfied
customers goes for its substitutable second item. An optimal ordering
policy has been derived for each period. The results are illustrated
with numerical examples. A sensitivity analysis has been done to
examine how sensitive the optimal solution and the maximum profit
are to the values of the discount factor, when there is a large number
of periods.
Abstract: In this paper multi-objective genetic algorithms are
employed for Pareto approach optimization of ideal Turboshaft
engines. In the multi-objective optimization a number of conflicting
objective functions are to be optimized simultaneously. The
important objective functions that have been considered for
optimization are specific thrust (F/m& 0), specific fuel consumption
( P S ), output shaft power 0 (& /&) shaft W m and overall efficiency( ) O
η .
These objectives are usually conflicting with each other. The design
variables consist of thermodynamic parameters (compressor pressure
ratio, turbine temperature ratio and Mach number).
At the first stage single objective optimization has been
investigated and the method of NSGA-II has been used for multiobjective
optimization. Optimization procedures are performed for
two and four objective functions and the results are compared for
ideal Turboshaft engine. In order to investigate the optimal
thermodynamic behavior of two objectives, different set, each
including two objectives of output parameters, are considered
individually. For each set Pareto front are depicted. The sets of
selected decision variables based on this Pareto front, will cause the
best possible combination of corresponding objective functions.
There is no superiority for the points on the Pareto front figure,
but they are superior to any other point. In the case of four objective
optimization the results are given in tables.
Abstract: The six sigma method is a project-driven management approach to improve the organization-s products, services, and processes by continually reducing defects in the organization. Understanding the key features, obstacles, and shortcomings of the six sigma method allows organizations to better support their strategic directions, and increasing needs for coaching, mentoring, and training. It also provides opportunities to better implement six sigma projects. The purpose of this paper is the survey of six sigma process and its impact on the organizational productivity. So I have studied key concepts , problem solving process of six sigmaas well as the survey of important fields such as: DMAIC, six sigma and productivity applied programme, and other advantages of six sigma. In the end of this paper, present research conclusions. (direct and positive relation between six sigma and productivity)
Abstract: Although the usefulness of fuzzy databases has been
pointed out in several works, they are not fully developed in numerous
domains. A task that is mostly disregarded and which is the topic
of this paper is the determination of suitable inequalities for fuzzy
sets in fuzzy query languages. This paper examines which kinds
of fuzzy inequalities exist at all. Afterwards, different procedures
are presented that appear theoretically appropriate. By being applied
to various examples, their strengths and weaknesses are revealed.
Furthermore, an algorithm for an efficient computation of the selected
fuzzy inequality is shown.
Abstract: In this research a comparison between k-epsilon and
LES model for a deoiling hydrocyclone is conducted. Flow field of
hydrocyclone is obtained by three-dimensional simulations with
OpenFOAM code. Potential of prediction for both methods of this
complex swirl flow is discussed. Large eddy simulation method
results have more similarity to experiment and its results are
presented in figures from different hydrocyclone cross sections.
Abstract: Web applications have become very complex and
crucial, especially when combined with areas such as CRM
(Customer Relationship Management) and BPR (Business Process
Reengineering), the scientific community has focused attention to
Web applications design, development, analysis, and testing, by
studying and proposing methodologies and tools. This paper
proposes an approach to automatic multi-dimensional concern
mining for Web Applications, based on concepts analysis, impact
analysis, and token-based concern identification. This approach lets
the user to analyse and traverse Web software relevant to a particular
concern (concept, goal, purpose, etc.) via multi-dimensional
separation of concerns, to document, understand and test Web
applications. This technique was developed in the context of WAAT
(Web Applications Analysis and Testing) project. A semi-automatic
tool to support this technique is currently under development.
Abstract: Mammographic images and data analysis to
facilitate modelling or computer aided diagnostic (CAD) software development should best be done using a common database that can handle various mammographic image file
formats and relate these to other patient information.
This would optimize the use of the data as both primary
reporting and enhanced information extraction of research data could be performed from the single dataset. One desired
improvement is the integration of DICOM file header information into the database, as an efficient and reliable source of supplementary patient information intrinsically
available in the images.
The purpose of this paper was to design a suitable database to link and integrate different types of image files and gather common information that can be further used for research
purposes. An interface was developed for accessing, adding,
updating, modifying and extracting data from the common
database, enhancing the future possible application of the data in CAD processing.
Technically, future developments envisaged include the creation of an advanced search function to selects image files
based on descriptor combinations. Results can be further used for specific CAD processing and other research. Design of a
user friendly configuration utility for importing of the required fields from the DICOM files must be done.
Abstract: Creating3D environments, including characters and
cities, is a significantly time consuming process due to a large amount
of workinvolved in designing and modelling.There have been a
number of attempts to automatically generate 3D objects employing
shape grammars. However it is still too early to apply the mechanism
to real problems such as real-time computer games.The purpose of this
research is to introduce a time efficient and cost effective method to
automatically generatevarious 3D objects for real-time 3D games.
This Shape grammar-based real-time City Generation (RCG) model is
a conceptual model for generating 3Denvironments in real-time and
can be applied to 3D gamesoranimations. The RCG system can
generate even a large cityby applying fundamental principles of shape
grammars to building elementsin various levels of detailin real-time.
Abstract: The new programming technologies allow for the
creation of components which can be automatically or manually
assembled to reach a new experience in knowledge understanding
and mastering or in getting skills for a specific knowledge area. The
project proposes an interactive framework that permits the creation,
combination and utilization of components that are specific to
mathematical training in high schools.
The main framework-s objectives are:
• authoring lessons by the teacher or the students; all they need
are simple operating skills for Equation Editor (or something
similar, or Latex); the rest are just drag & drop operations,
inserting data into a grid, or navigating through menus
• allowing sonorous presentations of mathematical texts and
solving hints (easier understood by the students)
• offering graphical representations of a mathematical function
edited in Equation
• storing of learning objects in a database
• storing of predefined lessons (efficient for expressions and
commands, the rest being calculations; allows a high
compression)
• viewing and/or modifying predefined lessons, according to the
curricula
The whole thing is focused on a mathematical expressions minicompiler,
storing the code that will be later used for different
purposes (tables, graphics, and optimisations).
Programming technologies used. A Visual C# .NET
implementation is proposed. New and innovative digital learning
objects for mathematics will be developed; they are capable to
interpret, contextualize and react depending on the architecture
where they are assembled.