Abstract: The IDR(s) method based on an extended IDR theorem was proposed by Sonneveld and van Gijzen. The original IDR(s) method has excellent property compared with the conventional iterative methods in terms of efficiency and small amount of memory. IDR(s) method, however, has unexpected property that relative residual 2-norm stagnates at the level of less than 10-12. In this paper, an effective strategy for stagnation detection, stagnation avoidance using adaptively information of parameter s and improvement of convergence rate itself of IDR(s) method are proposed in order to gain high accuracy of the approximated solution of IDR(s) method. Through numerical experiments, effectiveness of adaptive tuning IDR(s) method is verified and demonstrated.
Abstract: Most of the existing text mining approaches are
proposed, keeping in mind, transaction databases model. Thus, the
mined dataset is structured using just one concept: the “transaction",
whereas the whole dataset is modeled using the “set" abstract type. In
such cases, the structure of the whole dataset and the relationships
among the transactions themselves are not modeled and
consequently, not considered in the mining process.
We believe that taking into account structure properties of
hierarchically structured information (e.g. textual document, etc ...)
in the mining process, can leads to best results. For this purpose, an
hierarchical associations rule mining approach for textual documents
is proposed in this paper and the classical set-oriented mining
approach is reconsidered profits to a Direct Acyclic Graph (DAG)
oriented approach. Natural languages processing techniques are used
in order to obtain the DAG structure. Based on this graph model, an
hierarchical bottom up algorithm is proposed. The main idea is that
each node is mined with its parent node.
Abstract: The research investigates the effects of super plasticizer and molarity of sodium hydroxide alkaline solution on the workability, microstructure and compressive strength of self compacting geopolymer concrete (SCGC). SCGC is an improved way of concreting execution that does not require compaction and is made by complete elimination of ordinary Portland cement content. The parameters studied were superplasticizer (SP) dosage and molarity of NaOH solution. SCGC were synthesized from low calcium fly ash, activated by combinations of sodium hydroxide and sodium silicate solutions, and by incorporation of superplasticizer for self compactability. The workability properties such as filling ability, passing ability and resistance to segregation were assessed using slump flow, T-50, V-funnel, L-Box and J-ring test methods. It was found that the essential workability requirements for self compactability according to EFNARC were satisfied. Results showed that the workability and compressive strength improved with the increase in superplasticizer dosage. An increase in strength and a decrease in workability of these concrete samples were observed with the increase in molarity of NaOH solution from 8M to 14M. Improvement of interfacial transition zone (ITZ) and micro structure with the increase of SP and increase of concentration from 8M to 12M were also identified.
Abstract: Mercury is a natural occurring element and present in
various concentrations in the environment. Due to its toxic effects, it
is desirable to research mercury sensitive materials to adsorb
mercury. This paper describes the preparation of Au nanoparticles for
mercury adsorption by using a microwave (MW)-polyol method in
the presence of three different Sodium Chloride (NaCl)
concentrations (10, 20 and 30 mM). Mixtures of spherical, triangular,
octahedral, decahedral particles and 1-D product were obtained using
this rapid method. Sizes and shapes was found strongly depend on the
concentrations of NaCl. Without NaCl concentration, spherical,
triangular plates, octahedral, decahedral nanoparticles and 1D
product were produced. At the lower NaCl concentration (10 mM),
spherical, octahedral and decahedral nanoparticles were present,
while spherical and decahedral nanoparticles were preferentially form
by using 20 mM of NaCl concentration. Spherical, triangular plates,
octahedral and decahedral nanoparticles were obtained at the highest
NaCl concentration (30 mM). The amount of mercury adsorbed using
20 ppm mercury solution is the highest (67.5 %) for NaCl
concentration of 30 mM. The high yield of polygonal particles will
increase the mercury adsorption. In addition, the adsorption of
mercury is also due to the sizes of the particles. The sizes of particles
become smaller with increasing NaCl concentrations (size ranges, 5-
16 nm) than those synthesized without addition of NaCl (size ranges
11-32 nm). It is concluded that NaCl concentrations affects the
formation of sizes and shapes of Au nanoparticles thus affects the
mercury adsorption.
Abstract: Passive systems were born with the purpose of the
greatest exploitation of solar energy in cold climates and high
altitudes. They spread themselves until the 80-s all over the world
without any attention to the specific climate and the summer
behavior; this caused the deactivation of the systems due to a series
of problems connected to the summer overheating, the complex
management and the rising of the dust.
Until today the European regulation limits only the winter
consumptions without any attention to the summer behavior but, the
recent European EN 15251 underlines the relevance of the indoor
comfort, and the necessity of the analytic studies validation by
monitoring case studies.
In the porpose paper we demonstrate that the solar wall is an
efficient system both from thermal comfort and energy saving point
of view and it is the most suitable for our temperate climates because
it can be used as a passive cooling sistem too. In particular the paper
present an experimental and numerical analisys carried out on a case
study with nine different solar passive systems in Ancona, Italy.
We carried out a detailed study of the lodging provided by the
solar wall by the monitoring and the evaluation of the indoor
conditions.
Analyzing the monitored data, on the base of recognized models
of comfort (ISO, ASHRAE, Givoni-s BBCC), is emerged that the
solar wall has an optimal behavior in the middle seasons. In winter
phase this passive system gives more advantages in terms of energy
consumptions than the other systems, because it gives greater heat
gain and therefore smaller consumptions. In summer, when outside
air temperature return in the mean seasonal value, the indoor comfort
is optimal thanks to an efficient transversal ventilation activated from
the same wall.
Abstract: As the data-driven economy is growing faster than
ever and the demand for energy is being spurred, we are facing
unprecedented challenges of improving energy efficiency in data
centers. Effectively maximizing energy efficiency or minimising the
cooling energy demand is becoming pervasive for data centers. This
paper investigates overall energy consumption and the energy
efficiency of cooling system for a data center in Finland as a case
study. The power, cooling and energy consumption characteristics
and operation condition of facilities are examined and analysed.
Potential energy and cooling saving opportunities are identified and
further suggestions for improving the performance of cooling system
are put forward. Results are presented as a comprehensive evaluation
of both the energy performance and good practices of energy
efficient cooling operations for the data center. Utilization of an
energy recovery concept for cooling system is proposed. The
conclusion we can draw is that even though the analysed data center
demonstrated relatively high energy efficiency, based on its power
usage effectiveness value, there is still a significant potential for
energy saving from its cooling systems.
Abstract: New nondestructive technique, namely an inverse technique based on vibration tests, to characterize nonlinear mechanical properties of adhesive layers in sandwich composites is developed. An adhesive layer is described as a viscoelastic isotropic material with storage and loss moduli which are both frequency dependent values in wide frequency range. An optimization based on the planning of experiments and response surface technique to minimize the error functional is applied to decrease considerably the computational expenses. The developed identification technique has been tested on aluminum panels and successfully applied to characterize viscoelastic material properties of 3M damping polymer ISD-112 used as a core material in sandwich panels.
Abstract: Earthquakes produce some of the most violent loading
situations that a structure can be subjected to and if a structure fails
under these loads then inevitably human life is put at risk. One of the
most common methods by which a structure fails under seismic
loading is at the connection of structural elements. The research
presented in this paper investigates the interlock systems as a novel
method for building structures. The main objective of this
experimental study wasto determine the dynamic characteristics and
the seismic behaviour of the proposed structures compared to
conventional structural systemsduring seismic motions. Results of
this study indicate that the interlock mechanism of the panels
influences the behaviour of lateral load-resisting systems of the
structures during earthquakes, contributing to better structural
flexibility and easier maintenance.
Abstract: Grid computing is a form of distributed computing
that involves coordinating and sharing computational power, data
storage and network resources across dynamic and geographically
dispersed organizations. Scheduling onto the Grid is NP-complete,
so there is no best scheduling algorithm for all grid computing
systems. An alternative is to select an appropriate scheduling
algorithm to use in a given grid environment because of the
characteristics of the tasks, machines and network connectivity. Job
and resource scheduling is one of the key research area in grid
computing. The goal of scheduling is to achieve highest possible
system throughput and to match the application need with the
available computing resources. Motivation of the survey is to
encourage the amateur researcher in the field of grid computing, so
that they can understand easily the concept of scheduling and can
contribute in developing more efficient scheduling algorithm. This
will benefit interested researchers to carry out further work in this
thrust area of research.
Abstract: The deficit of power for electricity demand reaches
almost 30% for consumers in the last few years. This reflects with
continually increasing the price of electricity, and today the price for
small industry is almost 110Euro/MWh. The high price is additional
problem for the owners in the economy crisis which is reflected with
higher price of the goods.
The paper gives analyses of the energy needs for real agro
complex in Macedonia, private vinery with capacity of over 2 million
liters in a year and with self grapes and fruits fields. The existing
power supply is from grid with 10/04 kV transformer. The
geographical and meteorological condition of the vinery location
gives opportunity for including renewable as a power supply option
for the vinery complex.
After observation of the monthly energy needs for the vinery, the
base scenario is the existing power supply from the distribution grid.
The electricity bill in small industry has three factors: electricity in
high and low tariffs in kWh and the power engaged for the
technological process of production in kW. These three factors make
the total electricity bill and it is over 110 Euro/MWh which is the
price near competitive for renewable option. On the other side
investments in renewable (especially photovoltaic (PV)) has tendency
of decreasing with price of near 1,5 Euro/W. This means that
renewable with PV can be real option for power supply for small
industry capacities (under 500kW installed power).
Therefore, the other scenarios give the option with PV and the last
one includes wind option. The paper presents some scenarios for
power supply of the vinery as the followings:
• Base scenario of existing conventional power supply from the
grid
• Scenario with implementation of renewable of Photovoltaic
• Scenario with implementation of renewable of Photovoltaic and
Wind power
The total power installed in a vinery is near 570 kW, but the
maximum needs are around 250kW. At the end of the full paper some
of the results from scenarios will be presented. The paper also
includes the environmental impacts of the renewable scenarios, as
well as financial needs for investments and revenues from renewable.
Abstract: The paper presents the results of research on trends in shaping of multifamily buildings in Poland on the example of Wrocław, after Polish accession to the European Union. The study is conducted within the research project: “Trends in creating of multifamily housing development since 2004, on the Wrocław study case" supported by Polish Ministry of Science and Higher Education and will be completed in November 2011. The research involves multifamily buildings completed in the last decade, in term of fundamental urbanization factors such as: building-s coefficient area, useable area, green area (biologically active surface), intensity of building development, amount of dwellings, dwelling area, amount of parking places, numbers of floors, etc. The analysis of these indicators was conducted based on the date obtained in the study of approximately one hundred new housing units, completed in Wroclaw. The analysis attempts to formulate the main trends in creating of housing policy in Poland during the last 10 years in reference to local urban policy.
Abstract: Theory of Constraints has been emerging as an
important tool for optimization of manufacturing/service systems.
Goldratt in his first book “ The Goal " gave the introduction on
Theory of Constraints and its applications in a factory scenario. A
large number of production managers around the globe read this book
but only a few could implement it in their plants because the book did
not explain the steps to implement TOC in the factory. To overcome
these limitations, Goldratt wrote this book to explain TOC, DBR and
the method to implement it. In this paper, an attempt has been made
to summarize the salient features of TOC and DBR listed in the book
and the correct approach to implement TOC in a factory setting. The
simulator available along with the book was actually used by the
authors and the claim of Goldratt regarding the use of DBR and
Buffer management to ease the work of production managers was
tested and was found to be correct.
Abstract: The concept of e-Learning is now emerging in Sub Saharan African countries like Tanzania. Due to economic constraints and other social and cultural factors faced by these countries, the use of Information and Communication Technology (ICT) is increasing at a very low pace. The digital divide threat has propelled the Government of Tanzania to put in place the national ICT Policy in 2003 which defines the direction of all ICT activities nationally. Among the main focused areas is the use of ICT in education, since for the development of any country, there is a need of creating knowledge based society. This paper discusses the initiatives made so far to introduce the use of ICT tools to some secondary schools using open source software in e-content development to facilitate a self-learning environment
Abstract: This paper presents the use of Legendre pseudospectral
method for the optimization of finite-thrust orbital transfer for
spacecrafts. In order to get an accurate solution, the System-s
dynamics equations were normalized through a dimensionless method.
The Legendre pseudospectral method is based on interpolating
functions on Legendre-Gauss-Lobatto (LGL) quadrature nodes. This
is used to transform the optimal control problem into a constrained
parameter optimization problem. The developed novel optimization
algorithm can be used to solve similar optimization problems of
spacecraft finite-thrust orbital transfer. The results of a numerical
simulation verified the validity of the proposed optimization method.
The simulation results reveal that pseudospectral optimization method
is a promising method for real-time trajectory optimization and
provides good accuracy and fast convergence.
Abstract: In this paper, we propose a robust face relighting
technique by using spherical space properties. The proposed method
is done for reducing the illumination effects on face recognition.
Given a single 2D face image, we relight the face object by
extracting the nine spherical harmonic bases and the face spherical
illumination coefficients. First, an internal training illumination
database is generated by computing face albedo and face normal
from 2D images under different lighting conditions. Based on the
generated database, we analyze the target face pixels and compare
them with the training bootstrap by using pre-generated tiles. In this
work, practical real time processing speed and small image size were
considered when designing the framework. In contrast to other works,
our technique requires no 3D face models for the training process
and takes a single 2D image as an input. Experimental results on
publicly available databases show that the proposed technique works
well under severe lighting conditions with significant improvements
on the face recognition rates.
Abstract: In this paper, a novel system
recognition of human faces without using face
different color photographs is proposed. It mainly in
face detection, normalization and recognition. Foot
method of combination of Haar-like face determined
segmentation and region-based histogram stretchi
(RHST) is proposed to achieve more accurate perf
using Haar. Apart from an effective angle norm
side-face (pose) normalization, which is almost a might be important and beneficial for the prepr
introduced. Then histogram-based and photom
normalization methods are investigated and ada
retinex (ASR) is selected for its satisfactory illumin
Finally, weighted multi-block local binary pattern
with 3 distance measures is applied for pair-mat
Experimental results show its advantageous perfo
with PCA and multi-block LBP, based on a principle.
Abstract: A steady two-phase flow model has been developed to simulate the drying process of porous particle in a pneumatic conveying dryer. The model takes into account the momentum, heat and mass transfer between the continuous phase and the dispersed phase. A single particle model was employed to calculate the evaporation rate. In this model the pore structure is simplified to allow the dominant evaporation mechanism to be readily identified at all points within the duct. The predominant mechanism at any time depends upon the pressure, temperature and the diameter of pore from which evaporating is occurring. The model was validated against experimental studies of pneumatic transport at low and high speeds as well as pneumatic drying. The effects of operating conditions on the dryer parameters are studied numerically. The present results show that the drying rate is enhanced as the inlet gas temperature and the gas flow rate increase and as the solid mass flow rate deceases. The present results also demonstrate the necessity of measuring the inlet gas velocity or the solid concentration in any experimental analysis.
Abstract: Continuously growing needs for Internet applications
that transmit massive amount of data have led to the emergence of
high speed network. Data transfer must take place without any
congestion and hence feedback parameters must be transferred from
the receiver end to the sender end so as to restrict the sending rate in
order to avoid congestion. Even though TCP tries to avoid
congestion by restricting the sending rate and window size, it never
announces the sender about the capacity of the data to be sent and
also it reduces the window size by half at the time of congestion
therefore resulting in the decrease of throughput, low utilization of
the bandwidth and maximum delay. In this paper, XCP protocol is
used and feedback parameters are calculated based on arrival rate,
service rate, traffic rate and queue size and hence the receiver
informs the sender about the throughput, capacity of the data to be
sent and window size adjustment, resulting in no drastic decrease in
window size, better increase in sending rate because of which there is
a continuous flow of data without congestion. Therefore as a result of
this, there is a maximum increase in throughput, high utilization of
the bandwidth and minimum delay. The result of the proposed work
is presented as a graph based on throughput, delay and window size.
Thus in this paper, XCP protocol is well illustrated and the various
parameters are thoroughly analyzed and adequately presented.
Abstract: Genetic Algorithms (GAs) are direct searching
methods which require little information from design space. This
characteristic beside robustness of these algorithms makes them to be
very popular in recent decades. On the other hand, while this method
is employed, there is no guarantee to achieve optimum results. This
obliged designer to run such algorithms more than one time to
achieve more reliable results. There are many attempts to modify the
algorithms to make them more efficient. In this paper, by application
of fractal dimension (particularly, Box Counting Method), the
complexity of design space are established for determination of
mutation and crossover probabilities (Pm and Pc). This methodology
is followed by a numerical example for more clarification. It is
concluded that this modification will improve efficiency of GAs and
make them to bring about more reliable results especially for design
space with higher fractal dimensions.
Abstract: Plastics occupy wide place in the applications of
automotive, electronics and house goods. Especially reinforced
plastics become popular because of their high strength besides their
advantages of low weight and easy manufacturability. In this study,
mechanical and morphological properties of polypropylene (PP) and
high density polyethylene (HDPE) matrix composites reinforced with
surface modified nano titan dioxide (TiO2) particles were
investigated. Surface modification was made by coating the nano
powders with maleic anhydride grafted styrene ethylene butylene
styrene (SEBS-g-MA) and silane, respectively. After surface
modification, PP/TiO2 and HDPE/TiO2 composites were obtained by
using twin screw extruder at titan dioxide loading of 1 wt.%, 3 wt.%
and 5 wt.%. Effects of surface modification were determined by
thermal and morphological analysis. SEBS-g-MA provided bridging
effect between TiO2 particles and polymer matrix while silane was
effective as a dispersant. Depending on that, homogenous structures
without agglomeration were obtained. Mechanical tests were
performed on the injection moldings of the composites for obtaining
the impact strength, tensile strength, stress at break, elongation and
elastic modulus. Reinforced HDPE and PP moldings gave higher
tensile strength and elastic modulus due to the rigid structure of TiO2.
Slight increment was seen in stress at break. Elongation and impact
strength decreased due to the stiffness of the nano titan dioxide.