Abstract: In this paper we study some numerical methods to solve a model one-dimensional convection–diffusion equation. The semi-discretisation of the space variable results into a system of ordinary differential equations and the solution of the latter involves the evaluation of a matrix exponent. Since the calculation of this term is computationally expensive, we study some methods based on Krylov subspace and on Restrictive Taylor series approximation respectively. We also consider the Chebyshev Pseudospectral collocation method to do the spatial discretisation and we present the numerical solution obtained by these methods.
Abstract: Optimal cultural site selection is one of the ways that
can lead to the promotion of citizenship culture in addition to
ensuring the health and leisure of city residents. This study examines
the social and cultural needs of the community and optimal cultural
site allocation and after identifying the problems and shortcomings,
provides a suitable model for finding the best location for these
centers where there is the greatest impact on the promotion of
citizenship culture. On the other hand, non-scientific methods cause
irreversible impacts to the urban environment and citizens. But
modern efficient methods can reduce these impacts. One of these
methods is using geographical information systems (GIS). In this
study, Analytical Hierarchy Process (AHP) method was used to
locate the optimal cultural site. In AHP, three principles
(decomposition), (comparative analysis), and (combining
preferences) are used. The objectives of this research include
providing optimal contexts for passing time and performing cultural
activities by Shiraz residents and also proposing construction of some
cultural sites in different areas of the city. The results of this study
show the correct positioning of cultural sites based on social needs of
citizens. Thus, considering the population parameters and radii
access, GIS and AHP model for locating cultural centers can meet
social needs of citizens.
Abstract: Assume that we have m identical graphs where the
graphs consists of paths with k vertices where k is a positive integer.
In this paper, we discuss certain labelling of the m graphs called
c-Erdösian for some positive integers c. We regard labellings of the
vertices of the graphs by positive integers, which induce the edge
labels for the paths as the sum of the two incident vertex labels.
They have the property that each vertex label and edge label appears
only once in the set of positive integers {c, . . . , c+6m- 1}. Here,
we show how to construct certain c-Erdösian of m paths with 2 and
3 vertices by using Skolem sequences.
Abstract: Indices summarizing community structure are used to
evaluate fundamental community ecology, species interaction,
biogeographical factors, and environmental stress. Some of these
indices are insensitive to gross community changes induced by
contaminants of pollution. Diversity indices and similarity indices are
reviewed considering their ecological application, both theoretical
and practical. For some useful indices, empirical equations are given
to calculate the expected maximum value of the indices to which the
observed values can be related at any combination of sample sizes at
the experimental sites. This paper examines the effects of sample size
and diversity on the expected values of diversity indices and
similarity indices, using various formulae. It has been shown that all
indices are strongly affected by sample size and diversity. In some
indices, this influence is greater than the others and an attempt has
been made to deal with these influences.
Abstract: As the resources for naturally occurring aggregates
diminished at an ever increasing rate, researchers are keen to utilize
recycled materials in road construction in harmony with sustainable
development. Steel slag, a waste product from the steel making
industry, is one of the recycled materials reported to exhibit great
potential to replace naturally occurring aggregates in asphalt
mixtures. This paper presents the resilient modulus properties of
steel slag asphalt mixtures subjected to short term oven ageing
(STOA). The resilient modulus test was carried out to evaluate the
stiffness of asphalt mixtures at 10ºC, 25ºC and 40ºC. Previous
studies showed that stiffness changes in asphalt mixture played an
important role in inflicting pavement distress particularly cracking
and rutting that are common at low and high temperatures
respectively. Temperature was found to significantly influence the
resilient modulus of asphalt mixes. The resilient modulus of the
asphalt specimens tested decreased by more than 90% when the test
temperature increased from 10°C to 40°C.
Abstract: Eigenvector methods are gaining increasing acceptance in the area of spectrum estimation. This paper presents a successful attempt at testing and evaluating the performance of two of the most popular types of subspace techniques in determining the parameters of multiexponential signals with real decay constants buried in noise. In particular, MUSIC (Multiple Signal Classification) and minimum-norm techniques are examined. It is shown that these methods perform almost equally well on multiexponential signals with MUSIC displaying better defined peaks.
Abstract: Web services provide significant new benefits for SOAbased
applications, but they also expose significant new security
risks. There are huge number of WS security standards and
processes. At present, there is still a lack of a comprehensive
approach which offers a methodical development in the construction
of secure WS-based SOA. Thus, the main objective of this paper is
to address this needs, presenting a comprehensive method for Web
Services Security guaranty in SOA. The proposed method defines
three stages, Initial Security Analysis, Architectural Security
Guaranty and WS Security Standards Identification. These facilitate,
respectively, the definition and analysis of WS-specific security
requirements, the development of a WS-based security architecture
and the identification of the related WS security standards that the
security architecture must articulate in order to implement the
security services.
Abstract: The talks about technological convergence had been
around for almost twenty years. Today Internet made it possible. And
this is not only technical evolution. The way it changed our lives
reflected in variety of applications, services and technologies used in
day-to-day life. Such benefits imposed even more requirements on
heterogeneous and unreliable IP networks.
Current paper outlines QoS management system developed in the
NetQoS [1] project. It describes an overall architecture of
management system for heterogeneous networks and proposes
automated multi-layer QoS management. Paper focuses on the
structure of the most crucial modules of the system that enable
autonomous and multi-layer provisioning and dynamic adaptation.
Abstract: The quality attributes and storage life of 'Jinhwang' mango fruit can be effectively maintained with 1-methylcyclopropene (1-MCP) application and/or chitosan coating. 'Jinhwang' mango fruit was treated with 5 μl l-1 1-MCP for 12 h, dipped with 0.5 % chitosan, 5 μl l-1 1-MCP combine with 0.5 % chitosan and untreated (control) then stored at 10oC. Mango treated with 1-MCP maintained firmness, sucrose and starch content. Chitosan coating delayed firmness loss, sucrose content and the fruit decay when compare with control. Application of 1-MCP combine with chitosan also delayed firmness loss, sucrose content and starch content during storage. Furthermore, chitosan coating and combine treatment prolonged storage life of mango up to 29 days after storage while 1-MCP extended to 28 days after storage. Therefore, using all application of chitosan coating or 1-MCP combine with chitosan or 1-MCP in mango at 10oC is a feasible technology for maintains quality and prolongs storage life in order to expand marketability and export options.
Abstract: One of the potential and effective ways of
storing thermal energy in buildings is the integration of brick with phase change materials (PCMs). This paper presents a two-dimensional model for simulating and analyzing of PCM
in order to minimize energy consumption in the buildings. The numerical approach has been used with the real weather data of a selected city of Iran (Tehran). Two kinds of brick integrated PCM are investigated and compared base on
outdoor weather conditions and the amount of energy
consumption. The results show a significant reduction in
maximum entering heat flux to building about 32.8%
depending on PCM quantity. The results are analyzed by
various temperature contour plots. The contour plots
illustrated the time dependent mechanism of entering heat flux for a brick integrated with PCM. Further analysis is developed to investigate the effect of PCM location on the inlet heat flux. The results demonstrated that to achieve maximum performance of PCM it is better to locate PCM near the outdoor.
Abstract: It is well known that surface enhancements play an important role in augmenting the thermal performance of flat plate solar collector. In this paper, an attempt is made to explain in a comparative way the effect of surface geometry of solar collector having dimple geometry with that of a flat plate solar collector of the same size. A CFD analysis was carried out for the two cases, subjected to a constant heat flux of 600W/m2 and 1000W/m2. It can be inferred from the study that the absorber plate temperature shows a rise of average surface temperature of about 50C for the dimple solar collector when compared to a flat plate solar collector. Most importantly, the average exit water temperature shows a marked improvement of about 5.50C for a dimple solar collector as compared to that of a flat plate solar collector.
Abstract: Capital structure is one of the most important financial
decisions in corporate financing strategy. It involves the choice of
debt and equity level in financing a company-s operations. This study
aims to investigate whether the capital structure choice of Malaysian
electrical and electronic manufacturing companies that are listed in
the Bursa Malaysia can be explained by factors that have been found
by most studies as dominant determinants of capital structure
(company size, profitability, asset tangibility, liquidity and growth).
Using debt ratio as the proxy for capital structure and applying
pooled ordinary least square multiple regression estimation, the
results showed that on average, Malaysian electrical and electronic
manufacturing companies used less debt in funding their business
operations. The findings also showed that size and asset tangibility
has a significant positive relationship with debt level, while liquidity
has a negative significant relationship with leverage.
Abstract: Automatic determination of blood in less bright or
noisy capsule endoscopic images is difficult due to low S/N ratio.
Especially it may not be accurate to analyze these images due to the
influence of external disturbance. Therefore, we proposed detection
methods that are not dependent only on color bands. In locating
bleeding regions, the identification of object outlines in the frame and
features of their local colors were taken into consideration. The results
showed that the capability of detecting bleeding was much improved.
Abstract: Manufacturing, production and service industries within Libya have struggled with many problems during the past two decades due to many difficulties. These problems have created a negative impact on the productivity and utilization of many industries around the country. This paper studies the implementation levels of the manufacturing control systems known as Manufacturing Resource Planning (MRPII) being adapted within some Libyan industries. A survey methodology has been applied for this research, based on the survey analysis, the results pointed out that the system within these industries has a modest strategy towards most of the areas that are considered as being very crucial in implementing these systems successfully. The findings also show a variation within these implementation levels with a respect to the key-elements that related to MRPII, giving the highest levels in the emphasise on financial data accuracy. The paper has also identified limitations within the investigated manufacturing and managerial areas and has pointed to where senior managers should take immediate actions in order to achieve effective implementation of MRPII within their business area.
Abstract: Collaborative problem solving in e-learning can take
in the form of discussion among learner, creating a highly social
learning environment and characterized by participation and
interactivity. This paper, designed a collaborative learning
environment where agent act as co-learner, can play different roles
during interaction. Since different roles have been assigned to the
agent, learner will assume that multiple co-learner exists to help and
guide him all throughout the collaborative problem solving process,
but in fact, alone during the learning process. Specifically, it answers
the questions what roles of the agent should be incorporated to
contribute better learning outcomes, how agent will facilitate the
communication process to provide social learning and interactivity
and what are the specific instructional strategies that facilitate learner
participation, increased skill acquisition and develop critical thinking.
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: Governments around the world are expending
considerable time and resources framing strategies and policies to
deliver energy security. The term 'energy security' has quietly
slipped into the energy lexicon without any meaningful discourse
about its meaning or assumptions. An examination of explicit and
inferred definitions finds that the concept is inherently slippery
because it is polysemic in nature having multiple dimensions and
taking on different specificities depending on the country (or
continent), timeframe or energy source to which it is applied. But
what does this mean for policymakers? Can traditional policy
approaches be used to address the problem of energy security or does
its- polysemic qualities mean that it should be treated as a 'wicked'
problem? To answer this question, the paper assesses energy security
against nine commonly cited characteristics of wicked policy
problems and finds strong evidence of 'wickedness'.
Abstract: Meshing is the process of discretizing problem
domain into many sub domains before the numerical calculation can
be performed. One of the most popular meshes among many types of meshes is tetrahedral mesh, due to their flexibility to fit into almost
any domain shape. In both 2D and 3D domains, triangular and tetrahedral meshes can be generated by using Delaunay triangulation.
The quality of mesh is an important factor in performing any Computational Fluid Dynamics (CFD) simulations as the results is
highly affected by the mesh quality. Many efforts had been done in
order to improve the quality of the mesh. The paper describes a mesh
generation routine which has been developed capable of generating
high quality tetrahedral cells in arbitrary complex geometry. A few
test cases in CFD problems are used for testing the mesh generator.
The result of the mesh is compared with the one generated by a
commercial software. The results show that no sliver exists for the
meshes generated, and the overall quality is acceptable since the percentage of the bad tetrahedral is relatively small. The boundary
recovery was also successfully done where all the missing faces are
rebuilt.
Abstract: Lately there has been a significant boost of interest in
music digital libraries, which constitute an attractive area of research
and development due to their inherent interesting issues and
challenging technical problems, solutions to which will be highly
appreciated by enthusiastic end-users. We present here a DL that we
have developed to support users in their quest for classical music
pieces within a particular collection of 18,000+ audio recordings.
To cope with the early DL model limitations, we have used a refined
socio-semantic and contextual model that allows rich bibliographic
content description, along with semantic annotations, reviewing,
rating, knowledge sharing etc. The multi-layered service model
allows incorporation of local and distributed information,
construction of rich hypermedia documents, expressing the complex
relationships between various objects and multi-dimensional spaces,
agents, actors, services, communities, scenarios etc., and facilitates
collaborative activities to offer to individual users the needed
collections and services.