Abstract: This paper presents a novel method that allows an
agent host to delegate its signing power to an anonymous mobile
agent in such away that the mobile agent does not reveal any information about its host-s identity and, at the same time, can be authenticated by the service host, hence, ensuring fairness of service
provision. The solution introduces a verification server to verify the
signature generated by the mobile agent in such a way that even if colluding with the service host, both parties will not get more information than what they already have. The solution incorporates
three methods: Agent Signature Key Generation method, Agent
Signature Generation method, Agent Signature Verification method.
The most notable feature of the solution is that, in addition to allowing secure and anonymous signature delegation, it enables
tracking of malicious mobile agents when a service host is attacked. The security properties of the proposed solution are analyzed, and the solution is compared with the most related work.
Abstract: Elastic and inelastic scattering of α-particles by 9Be nuclei at different incident energies have been analyzed. Optical model parameters (OMPs) of α-particles elastic scattering by 9Be at different energies have been obtained. Coupled Reaction Channel (CRC) of elastic scattering, inelastic scattering and transfer reaction has been calculated using Fresco Code. The effect of involving CRC calculations on the analysis of differential cross section has been studied. The transfer reaction of (5He) in the reaction 9Be(α,9Be)α has been studied. The spectroscopic factor of 9Be≡α+5He has been extracted.
Abstract: This paper examines the students’ self-concept among 16- and 17- year- old adolescents in Malaysian secondary schools. Previous studies have shown that positive self-concept played an important role in student adjustment and academic performance during schooling. This study attempts to investigate the factors influencing students’ perceptions toward their own self-concept. A total of 1168 students participated in the survey. This study utilized the CoPs (UM) instrument to measure self-concept. Principal Component Analysis (PCA) revealed three factors: academic selfconcept, physical self-concept and social self-concept. This study confirmed that students perceived certain internal context factors, and revealed that external context factor also have an impact on their self-concept.
Abstract: In order to study the influence of different methods of controlling weeds such as mechanical weeding and mechanical weeder efficiency analysis in mechanical cultivation conditions, in farming year of 2011 an experiment was done in a farm in coupling and development of technology center in Haraz,Iran. The treatments consisted of (I) control treatment: where no weeding was done, (II) use of mechanical weeding without engine and (III) power mechanical weeding. Results showed that experimental treatments had significantly different effects (p=0.05) on yield traits and number of filled grains per panicle, while treatments had the significant effects on grain weight and dry weight of weeds in the first, second and third weeding methods at 1% of confidence level. Treatment (II) had its most significant effect on number of filled grains per panicle and yield performance standpoint, which was 3705.97 kg ha-1 in its highest peak. Treatment (III) was ranked as second influential with 3559.8 kg ha-1. In addition, under (I) treatments, 2364.73 kg ha-1 of yield produced. The minimum dry weights of weeds in all weeding methods were related to the treatment (II), (III) and (I), respectively. The correlation coefficient analysis showed that total yield had a significant positive correlation with the panicle grain yield per plant (r= 0.55*) and the number of grains per panicle-1 (r= 0.57*) and the number of filled grains (r= 0.63*). Total rice yield also had negative correlation of r= -0. 64* with weed dry weight at second weed sampling time (17 DAT). The weed dry weight at third and fourth sampling times (24 and 40 DAT) had negative correlations of -0.65** and r=-0.61* with rice yield, respectively.
Abstract: Unlike the best effort service provided by the internet
today, next-generation wireless networks will support real-time
applications. This paper proposes an adaptive early packet discard
(AEPD) policy to improve the performance of the real time TCP
traffic over ATM networks and avoid the fragmentation problem.
Three main aspects are incorporated in the proposed policy. First,
providing quality-of-service (QoS) guaranteed for real-time
applications by implementing a priority scheduling. Second,
resolving the partially corrupted packets problem by differentiating
the buffered cells of one packet from another. Third, adapting a
threshold dynamically using Fuzzy logic based on the traffic
behavior to maintain a high throughput under a variety of load
conditions. The simulation is run for two priority classes of the input
traffic: real time and non-real time classes. Simulation results show
that the proposed AEPD policy improves throughput and fairness
over that using static threshold under the same traffic conditions.
Abstract: Cogeneration may be defined as a system which
contains electricity production and regain of the thermo value of
exhaust gases simultaneously. The examination is based on the data-s
of an active cogeneration plant. This study, it is aimed to determine
which component of the system should be revised first to raise the
efficiency and decrease the loss of exergy. For this purpose, second
law analysis of thermodynamics is applied to each component due to
consider the effects of environmental conditions and take the quality
of energy into consideration as well as the quantity of it. The exergy
balance equations are produced and exergy loss is calculated for each
component. 44,44 % loss of exergy in heat exchanger, 29,59 % in
combustion chamber, 18,68 % in steam boiler, 5,25 % in gas turbine
and 2,03 % in compressor is calculated.
Abstract: In this paper, we study the knapsack sharing problem, a variant of the well-known NP-Hard single knapsack problem. We investigate the use of a tree search for optimally solving the problem. The used method combines two complementary phases: a reduction interval search phase and a branch and bound procedure one. First, the reduction phase applies a polynomial reduction strategy; that is used for decomposing the problem into a series of knapsack problems. Second, the tree search procedure is applied in order to attain a set of optimal capacities characterizing the knapsack problems. Finally, the performance of the proposed optimal algorithm is evaluated on a set of instances of the literature and its runtime is compared to the best exact algorithm of the literature.
Abstract: Neem is a highly heterozygous and commercially
important perennial plant. Conventionally, it is propagated by seeds
which loose viability within two weeks. Strictly cross pollinating
nature of the plant causes serious barrier to the genetic improvement
by conventional methods. Alternative methods of tree improvement
such as somatic hybridization, mutagenesis and genetic
transformation require an efficient in vitro plant regeneration system.
In this regard, somatic embryogenesis particularly secondary somatic
embryogenesis may offer an effective system for large scale plant
propagation without affecting the clonal fidelity of the regenerants. It
can be used for synthetic seed production, which further bolsters
conservation of this tree species which is otherwise very difficult
The present report describes the culture conditions necessary to
induce and maintain repetitive somatic embryogenesis, for the first
time, in neem. Out of various treatments tested, the somatic embryos
were induced directly from immature zygotic embryos of neem on
MS + TDZ (0.1 μM) + ABA (4 μM), in more than 76 % cultures.
Direct secondary somatic embryogenesis occurred from primary
somatic embryos on MS + IAA (5 μM) + GA3 (5 μM) in 12.5 %
cultures. Embryogenic competence of the explant as well as of the
primary embryos was maintained for a long period by repeated
subcultures at frequent intervals. A maximum of 10 % of these
somatic embryos were converted into plantlets.
Abstract: The paper investigates parallel channel instabilities of
natural circulation boiling water reactor. A thermal-hydraulic model
is developed to simulate two-phase flow behavior in the natural circulation boiling water reactor (NCBWR) with the incorporation of
ex-core components and recirculation loop such as steam separator, down-comer, lower-horizontal section and upper-horizontal section
and then, numerical analysis is carried out for parallel channel
instabilities of the reactor undergoing both in-phase and out-of-phase
modes of oscillations. To analyze the relative effect on stability of the reactor due to inclusion of various ex-core components and
recirculation loop, marginal stable point is obtained at a particular inlet enthalpy of the reactor core without the inclusion of ex-core
components and recirculation loop and then with the inclusion of the
same. Numerical simulations are also conducted to determine the
relative dominance between two modes of oscillations i.e. in-phase and out-of-phase. Simulations are also carried out when the channels
are subjected to asymmetric power distribution keeping the inlet enthalpy same.
Abstract: Horizontal wells are proven to be better producers
because they can be extended for a long distance in the pay zone.
Engineers have the technical means to forecast the well productivity
for a given horizontal length. However, experiences have shown that
the actual production rate is often significantly less than that of
forecasted. It is a difficult task, if not impossible to identify the real
reason why a horizontal well is not producing what was forecasted.
Often the source of problem lies in the drilling of horizontal section
such as permeability reduction in the pay zone due to mud invasion
or snaky well patterns created during drilling. Although drillers aim
to drill a constant inclination hole in the pay zone, the more frequent
outcome is a sinusoidal wellbore trajectory. The two factors, which
play an important role in wellbore tortuosity, are the inclination and
side force at bit. A constant inclination horizontal well can only be
drilled if the bit face is maintained perpendicular to longitudinal axis
of bottom hole assembly (BHA) while keeping the side force nil at
the bit. This approach assumes that there exists no formation force at
bit. Hence, an appropriate BHA can be designed if bit side force and
bit tilt are determined accurately. The Artificial Neural Network
(ANN) is superior to existing analytical techniques. In this study, the
neural networks have been employed as a general approximation tool
for estimation of the bit side forces. A number of samples are
analyzed with ANN for parameters of bit side force and the results
are compared with exact analysis. Back Propagation Neural network
(BPN) is used to approximation of bit side forces. Resultant low
relative error value of the test indicates the usability of the BPN in
this area.
Abstract: Combining energy efficiency with renewable energy
sources constitutes a key strategy for a sustainable future. The wind
power sector stands out as a fundamental element for the
achievement of the European renewable objectives and Portugal is no
exception to the increase of the wind energy for the electricity
generation. This work proposes an optimization model for the long
range electricity power planning in a system similar to the
Portuguese one, where the expected impacts of the increasing
installed wind power on the operating performance of thermal power
plants are taken into account. The main results indicate that the
increasing penetration of wind power in the electricity system will
have significant effects on the combined cycle gas power plants
operation and on the theoretically expected cost reduction and
environmental gains. This research demonstrated the need to address
the impact that energy sources with variable output may have, not
only on the short-term operational planning, but especially on the
medium to long range planning activities, in order to meet the
strategic objectives for the energy sector.
Abstract: Mathematical models can be used to describe the
dynamics of the spread of infectious disease between susceptibles
and infectious populations. Dengue fever is a re-emerging disease in
the tropical and subtropical regions of the world. Its incidence has
increased fourfold since 1970 and outbreaks are now reported quite
frequently from many parts of the world. In dengue endemic regions,
more cases of dengue infection in pregnancy and infancy are being
found due to the increasing incidence. It has been reported that
dengue infection was vertically transmitted to the infants. Primary
dengue infection is associated with mild to high fever, headache,
muscle pain and skin rash. Immune response includes IgM antibodies
produced by the 5th day of symptoms and persist for 30-60 days. IgG
antibodies appear on the 14th day and persist for life. Secondary
infections often result in high fever and in many cases with
hemorrhagic events and circulatory failure. In the present paper, a
mathematical model is proposed to simulate the succession of dengue
disease transmission in pregnancy and infancy. Stability analysis of
the equilibrium points is carried out and a simulation is given for the
different sets of parameter. Moreover, the bifurcation diagrams of our
model are discussed. The controlling of this disease in infant cases is
introduced in the term of the threshold condition.
Abstract: Decision support systems are usually based on
multidimensional structures which use the concept of hypercube.
Dimensions are the axes on which facts are analyzed and form a
space where a fact is located by a set of coordinates at the
intersections of members of dimensions. Conventional
multidimensional structures deal with discrete facts linked to discrete
dimensions. However, when dealing with natural continuous
phenomena the discrete representation is not adequate. There is a
need to integrate spatiotemporal continuity within multidimensional
structures to enable analysis and exploration of continuous field data.
Research issues that lead to the integration of spatiotemporal
continuity in multidimensional structures are numerous. In this paper,
we discuss research issues related to the integration of continuity in
multidimensional structures, present briefly a multidimensional
model for continuous field data. We also define new aggregation
operations. The model and the associated operations and measures
are validated by a prototype.
Abstract: This study, focusing on the importance of encouraging
outdoor activities for children, aims to propose and implement a
Web-GIS based outdoor education program for elementary schools,
which will then be evaluated by users. Specifically, for the purpose of
improved outdoor activities in the elementary school education, the
outdoor education program, with chiefly using the Web-GIS that
provides a good information provision and sharing tool, is proposed
and implemented before being evaluated by users. Conclusions of the
study boil down to:
(1) An eight-staged outdoor education program based on the Web-GIS
was proposed for a “second school" of an elementary school that
was then implemented before being evaluated by users (teachers,
instructors, students, and their parents).
(2) The program generally received a good evaluation, while a lot of
students and their parents evaluated negatively for the degree of
discovery and for the degree of interest, respectively, in the
questionnaire survey of students and their parents conducted after
the “second school". The surveys clearly show that an issue to be
solved, from the viewpoint of teachers in particular, is the
establishment of the GIS that will easily represent teaching materials
developed by teachers and of Web-GIS, and improved significance
of the use of GIS and Web-GIS for their widespread.
Abstract: Image registration plays an important role in the
diagnosis of dental pathologies such as dental caries, alveolar bone
loss and periapical lesions etc. This paper presents a new wavelet
based algorithm for registering noisy and poor contrast dental x-rays.
Proposed algorithm has two stages. First stage is a preprocessing
stage, removes the noise from the x-ray images. Gaussian filter has
been used. Second stage is a geometric transformation stage.
Proposed work uses two levels of affine transformation. Wavelet
coefficients are correlated instead of gray values. Algorithm has been
applied on number of pre and post RCT (Root canal treatment)
periapical radiographs. Root Mean Square Error (RMSE) and
Correlation coefficients (CC) are used for quantitative evaluation.
Proposed technique outperforms conventional Multiresolution
strategy based image registration technique and manual registration
technique.
Abstract: This paper presents a possibilistic (fuzzy) model in optimal siting and sizing of Distributed Generation (DG) for loss reduction and improve voltage profile in power distribution system. Multi-objective problem is developed in two phases. In the first one, the set of non-dominated planning solutions is obtained (with respect to the objective functions of fuzzy economic cost, and exposure) using genetic algorithm. In the second phase, one solution of the set of non-dominated solutions is selected as optimal solution, using a suitable max-min approach. This method can be determined operation-mode (PV or PQ) of DG. Because of considering load uncertainty in this paper, it can be obtained realistic results. The whole process of this method has been implemented in the MATLAB7 environment with technical and economic consideration for loss reduction and voltage profile improvement. Through numerical example the validity of the proposed method is verified.
Abstract: ebXML (Electronic Business using eXtensible
Markup Language) is an e-business standard, sponsored by
UN/CEFACT and OASIS, which enables enterprises to exchange
business messages, conduct trading relationships, communicate
data in common terms and define and register business
processes. While there is tremendous e-business value in the
ebXML, security remains an unsolved problem and one of the
largest barriers to adoption. XML security technologies emerging
recently have extensibility and flexibility suitable for security
implementation such as encryption, digital signature, access
control and authentication.
In this paper, we propose ebXML business transaction models
that allow trading partners to securely exchange XML based
business transactions by employing XML security technologies.
We show how each XML security technology meets the ebXML
standard by constructing the test software and validating messages
between the trading partners.
Abstract: With the tremendous growth of World Wide Web
(WWW) data, there is an emerging need for effective information
retrieval at the document level. Several query languages such as
XML-QL, XPath, XQL, Quilt and XQuery are proposed in recent
years to provide faster way of querying XML data, but they still lack of
generality and efficiency. Our approach towards evolving a framework
for querying semistructured documents is based on formal query
algebra. Two elements are introduced in the proposed framework:
first, a generic and flexible data model for logical representation of
semistructured data and second, a set of operators for the manipulation
of objects defined in the data model. In additional to accommodating
several peculiarities of semistructured data, our model offers novel
features such as bidirectional paths for navigational querying and
partitions for data transformation that are not available in other
proposals.
Abstract: Transportation authorities need to provide the services
and facilities that are critical to every country-s well-being and
development. Management of the road network is becoming
increasingly challenging as demands increase and resources are
limited. Public sector institutions are integrating performance
information into budgeting, managing and reporting via
implementing performance measurement systems. In the face of
growing challenges, performance measurement of road networks is
attracting growing interest in many countries. The large scale of
public investments makes the maintenance and development of road
networks an area where such systems are an important assessment
tool. Transportation agencies have been using performance
measurement and modeling as part of pavement and bridge
management systems. Recently the focus has been on extending the
process to applications in road construction and maintenance
systems, operations and safety programs, and administrative
structures and procedures. To eliminate failure and dysfunctional
consequences the importance of obtaining objective data and
implementing evaluation instrument where necessary is presented in
this paper
Abstract: The paper deals with results of a project “Interoperability Workplaces to Support Teaching of Security Management in a Computer Network". This project is focused on the perspectives and possibilities of "new approaches" to education, training and crisis communication of rescue teams in the Czech Republic. It means that common technologies considering new perspectives are used to educate selected members of crisis management. The main part concentrates on possibilities of application of new technology and computer-aided tools to education and training of Integrated Rescue System teams.This project uses the COST principle for the creation of specialized centers and for all communication between these workplaces.