Abstract: Ant colony based routing algorithms are known to
grantee the packet delivery, but they suffer from the huge overhead
of control messages which are needed to discover the route. In this
paper we utilize the network nodes positions to group the nodes
in connected clusters. We use clusters-heads only on forwarding
the route discovery control messages. Our simulations proved that
the new algorithm has decreased the overhead dramatically without
affecting the delivery rate.
Abstract: The paper presents a one-dimensional transient
mathematical model of thermal oil-water two-phase emulsion flows
in pipes. The set of the mass, momentum and enthalpy conservation
equations for the continuous fluid and droplet phases are solved. Two
friction correlations for the continuous fluid phase to wall friction are
accounted for in the model and tested. The aerodynamic drag force
between the continuous fluid phase and droplets is modeled, too. The
density and viscosity of both phases are assumed to be constant due
to adiabatic experimental conditions. The proposed mathematical
model is validated on the experimental measurements of oil-water
emulsion flows in horizontal pipe [1,2]. Numerical analysis on
single- and two-phase oil-water flows in a pipe is presented in the
paper. The continuous oil flow having water droplets is simulated.
Predictions, which are performed by using the presented model, show
excellent agreement with the experimental data if the water fraction is
equal or less than 10%. Disagreement between simulations and
measurements is increased if the water fraction is larger than 10%.
Abstract: The Elliptic Curve Digital Signature Algorithm
(ECDSA) is the elliptic curve analogue of DSA, where it is a digital
signature scheme designed to provide a digital signature based on a
secret number known only to the signer and also on the actual
message being signed. These digital signatures are considered the
digital counterparts to handwritten signatures, and are the basis for
validating the authenticity of a connection. The security of these
schemes results from the infeasibility to compute the signature
without the private key. In this paper we introduce a proposed to
development the original ECDSA with more complexity.
Abstract: The fundamental objective of the university is to
genuinely provide a higher education to mankind and society. Higher
education institutions earn billions of dollars in research funds, granted
by national government or related institutions, which literally came
from taxpayers. Everyday universities consume those grants; in return,
provide society with a human resource and research developments.
However, not all taxpayers have their major concerns on those
researches, other than that they are more curiously to see the project
being build tangibly and evidently to certify what they pay for. This
paper introduces the concept of University – Community Business
Continuity Management for Disaster – Resilient City, which modified
the concept of Business Continuity Management (BCM) toward
university community to create advancing collaboration leading to the
disaster – resilient community and city. This paper focuses on
describing in details the backgrounds and principles of the concept and
discussing the advantages and limitations of the concept.
Abstract: In article are analyzed value of audiovisual sources which possesses high integrative potential and allows studying movement of information in the history - information movement from generation to the generation, in essence providing continuity of historical development and inheritance of traditions. Information thus fixed in them is considered as a source not only about last condition of society, but also significant for programming of its subsequent activity.
Abstract: This paper presents an integrated knowledge-based
approach to multi-scale modeling of aquatic systems, with a view to
enhancing predictive power and aiding environmental management
and policy-making. The basic phases of this approach have been
exemplified in the case of a bay in Saronicos Gulf (Attiki, Greece).
The results showed a significant problem with rising phytoplankton
blooms linked to excessive microbial growth, arisen mostly due to
increased nitrogen inflows; therefore, the nitrification/denitrification
processes of the benthic and water column sub-systems have
provided the quality variables to be monitored for assessing
environmental status. It is thereby demonstrated that the proposed
approach facilitates modeling choices and implementation option
decisions, while it provides substantial support for knowledge and
experience capitalization in long-term water management.
Abstract: Team distillation assisted by microwave extraction
(SDAM) considered as accelerated technique extraction is a
combination of microwave heating and steam distillation, performed
at atmospheric pressure. SDAM has been compared with the same
technique coupled with the cryogrinding of seeds (SDAM -CG).
Isolation and concentration of volatile compounds are performed by a
single stage for the extraction of essential oil from Cuminum
cyminum seeds. The essential oils extracted by these two methods for
5 min were quantitatively (yield) and qualitatively (aromatic profile)
no similar. These methods yield an essential oil with higher amounts
of more valuable oxygenated compounds, and allow substantial
savings of costs, in terms of time, energy and plant material. SDAM
and SDAM-CG is a green technology and appears as a good
alternative for the extraction of essential oils from aromatic plants.
Abstract: Classification is one of the primary themes in
computational biology. The accuracy of classification strongly
depends on quality of a dataset, and we need some method to
evaluate this quality. In this paper, we propose a new graphical
analysis method using 'Membership-Deviation Graph (MDG)' for
analyzing quality of a dataset. MDG represents degree of
membership and deviations for instances of a class in the dataset. The
result of MDG analysis is used for understanding specific feature and
for selecting best feature for classification.
Abstract: This study considers the problem of determining
operation and maintenance schedules for a containership equipped
with components during its sailing according to a pre-determined
navigation schedule. The operation schedule, which specifies work
time of each component, determines the due-date of each maintenance
activity, and the maintenance schedule specifies the actual start
time of each maintenance activity. The main constraints are component
requirements, workforce availability, working time limitation,
and inter-maintenance time. To represent the problem mathematically,
a mixed integer programming model is developed. Then,
due to the problem complexity, we suggest a heuristic for the objective
of minimizing the sum of earliness and tardiness between the
due-date and the starting time of each maintenance activity. Computational
experiments were done on various test instances and the
results are reported.
Abstract: When the profile information of an existing road is
missing or not up-to-date and the parameters of the vertical
alignment are needed for engineering analysis, the engineer has to recreate
the geometric design features of the road alignment using
collected profile data. The profile data may be collected using
traditional surveying methods, global positioning systems, or digital
imagery. This paper develops a method that estimates the parameters
of the geometric features that best characterize the existing vertical
alignments in terms of tangents and the expressions of the curve, that
may be symmetrical, asymmetrical, reverse, and complex vertical
curves. The method is implemented using an Excel-based
optimization method that minimizes the differences between the
observed profile and the profiles estimated from the equations of the
vertical curve. The method uses a 'wireframe' representation of the
profile that makes the proposed method applicable to all types of
vertical curves. A secondary contribution of this paper is to introduce
the properties of the equal-arc asymmetrical curve that has been
recently developed in the highway geometric design field.
Abstract: Isobaric vapor-liquid equilibrium measurements are reported for the binary mixtures of Mesitylene + 1-Heptanol and Mesitylene + 1-Octanol at 97.3 kPa. The measurements have been performed using a vapor recirculating type (modified Othmer's) equilibrium still. Both the mixtures show positive deviation from ideality. The Mesitylene + 1-Heptanol mixture forms an azeotrope whereas Mesitylene + 1- Octanol form a non – azeotropic mixture. The activity coefficients have been calculated taking into consideration the vapor phase nonideality. The data satisfy the thermodynamic consistency tests of Herington, and Hirata. The activity coefficients have been satisfactorily correlated by means of the Margules, Redlich-Kister, Wilson, Black, and NRTL equations. The activity coefficient values have also been obtained by UNIFAC method.
Abstract: In this paper we will develop further the sequential life test approach presented in a previous article by [1] using an underlying two parameter Inverse Weibull sampling distribution. The location parameter or minimum life will be considered equal to zero. Once again we will provide rules for making one of the three possible decisions as each observation becomes available; that is: accept the null hypothesis H0; reject the null hypothesis H0; or obtain additional information by making another observation. The product being analyzed is a new electronic component. There is little information available about the possible values the parameters of the corresponding Inverse Weibull underlying sampling distribution could have.To estimate the shape and the scale parameters of the underlying Inverse Weibull model we will use a maximum likelihood approach for censored failure data. A new example will further develop the proposed sequential life testing approach.
Abstract: The goal of this work is to improve the efficiency and the reliability of the automatic artifact rejection, in particular from the Electroencephalographic (EEG) recordings. Artifact rejection is a key topic in signal processing. The artifacts are unwelcome signals that may occur during the signal acquisition and that may alter the analysis of the signals themselves. A technique for the automatic artifact rejection, based on the Independent Component Analysis (ICA) for the artifact extraction and on some high order statistics such as kurtosis and Shannon-s entropy, was proposed some years ago in literature. In this paper we enhance this technique introducing the Renyi-s entropy. The performance of our method was tested exploiting the Independent Component scalp maps and it was compared to the performance of the method in literature and it showed to outperform it.
Abstract: The aim of this paper is to explore the security issues
that significantly affect the performance of Mobile Adhoc Networks
(MANET)and limit the services provided to their intended users. The
MANETs are more vulnerable to Distributed Denial of Service
attacks (DDoS) because of their properties like shared medium,
dynamic topologies etc. A DDoS attack is a coordinated attempt
made by malicious users to flood the victim network with the large
amount of data such that the resources of the victim network are
exhausted resulting in the deterioration of the network performance.
This paper highlights the effects of different types of DDoS attacks
in MANETs and categorizes them according to their behavior.
Abstract: Recently, a growing interest has emerged on the
development of new and efficient energy sources, due to the inevitable extinction of the nonrenewable energy reserves. One of
these alternative sources which has a great potential and sustainability to meet up the energy demand is biomass energy. This
significant energy source can be utilized with various energy
conversion technologies, one of which is biomass gasification in
supercritical water.
Water, being the most important solvent in nature, has very important characteristics as a reaction solvent under supercritical
circumstances. At temperatures above its critical point (374.8oC and
22.1 MPa), water becomes more acidic and its diffusivity increases.
Working with water at high temperatures increases the thermal
reaction rate, which in consequence leads to a better dissolving of the
organic matters and a fast reaction with oxygen. Hence, supercritical water offers a control mechanism depending on solubility, excellent
transport properties based on its high diffusion ability and new reaction possibilities for hydrolysis or oxidation.
In this study the gasification of a real biomass, namely olive mill
wastewater (OMW), in supercritical water is investigated with the
use of Pt/Al2O3 and Ni/Al2O3 catalysts. OMW is a by-product
obtained during olive oil production, which has a complex nature
characterized by a high content of organic compounds and
polyphenols. These properties impose OMW a significant pollution
potential, but at the same time, the high content of organics makes
OMW a desirable biomass candidate for energy production.
All of the catalytic gasification experiments were made with five
different reaction temperatures (400, 450, 500, 550 and 600°C),
under a constant pressure of 25 MPa. For the experiments conducted
with Ni/Al2O3 catalyst, the effect of five reaction times (30, 60, 90,
120 and 150 s) was investigated. However, procuring that similar
gasification efficiencies could be obtained at shorter times, the experiments were made by using different reaction times (10, 15, 20,
25 and 30 s) for the case of Pt/Al2O3 catalyst. Through these experiments, the effects of temperature, time and catalyst type on the
gasification yields and treatment efficiencies were investigated.
Abstract: The primary education system in Indonesia involved the community recognized as the school committee, to take a part in the process of achieving the quality of education via the school facility performance, the low level of school committee involvement in the education system has become the issue in the development of education and reflected to the quality of education. This paper will discuss the conceptual framework and methodology for the performance of school committees within the management of school facilities in Batubara district of Indonesia. The concepts of Community based Facility Management (CbFM) and Logometrix are used as a basis to measure the school committee performance in order to address the needs of quality school management. The data will be taken from questionnaires distributed for those who work and use school facilities spread over seven sub district of Batubara, Indonesia. The result of this study is expected to provide a guide for evaluating the performance of existing school committee in improving the quality of education in Indonesia.
Abstract: In this work Artificial Intelligence (AI) techniques like Fuzzy logic, Genetic Algorithms and Particle Swarm Optimization have been used to improve the performance of the Automatic Generation Control (AGC) system. Instead of applying Genetic Algorithms and Particle swarm optimization independently for optimizing the parameters of the conventional AGC with PI controller, an intelligent tuned Fuzzy logic controller (acting as the secondary controller in the AGC system) has been designed. The controller gives an improved dynamic performance for both hydrothermal and thermal-thermal power systems under a variety of operating conditions.
Abstract: The successful use of CDMA technology is based on
the construction of large families of encoding sequences with good
correlation properties. This paper discusses PN sequence generation
based on Residue Arithmetic with an effort to improve the performance
of existing interference-limited CDMA technology for mobile
cellular systems. All spreading codes with residual number system
proposed earlier did not consider external interferences, multipath
propagation, Doppler effect etc. In literature the use of residual
arithmetic in DS-CDMA was restricted to encoding of already spread
sequence; where spreading of sequence is done by some existing
techniques. The novelty of this paper is the use of residual number
system in generation of the PN sequences which is used to spread
the message signal. The significance of cross-correlation factor in
alleviating multi-access interference is also discussed. The RNS based
PN sequence has superior performance than most of the existing
codes that are widely used in DS-CDMA applications. Simulation
results suggest that the performance of the proposed system is
superior to many existing systems.
Abstract: Significant changes in oil and gas drilling have
emphasized the need to verify the integrity and reliability of drill
stem components. Defects are inevitable in cast components,
regardless of application; but if these defects go undetected, any
severe defect could cause down-hole failure.
One such defect is shrinkage porosity. Castings with lower level
shrinkage porosity (CB levels 1 and 2) have scattered pores and do
not occupy large volumes; so pressure testing and helium leak testing
(HLT) are sufficient for qualifying the castings. However, castings
with shrinkage porosity of CB level 3 and higher, behave erratically
under pressure testing and HLT making these techniques insufficient
for evaluating the castings- integrity.
This paper presents a case study to highlight how the radiography
technique is much more effective than pressure testing and HLT.
Abstract: Nowadays over-consumption of fossil energy in
buildings especially in residential buildings and also considering the
increase in populations, the crisis of energy shortage in a near future
is predictable. The recent performance of developed countries in
construction with the aim of decreasing fossil energies shows that
these countries have understood the incoming crisis and has taken
reasonable and basic actions in this regard. However, Iranian
architecture, with several thousands years of history, has acquired
and executed invaluable experiences in designing, adapting and
coordinating with the nature.
Architectural studies during the recent decades show that imitating
modern western architecture results in high energy wastage beside
the fact that it not reasonably adaptable and corresponded with the
habits and customs of people unlike the architecture in the past which
was compatible and adaptable with the climatic conditions and this
necessitates optimal using of renewable energies more than ever. This
paper studies problems of design, execution and living in today's
houses and reviews the characteristics of climatic elements paying
special attention to the performance of trombe wall and solar
greenhouse in traditional houses and offers some suggestions for
combining these two elements and a climatic strategy.