Abstract: This paper analyses the unsteady, two-dimensional
stagnation point flow of an incompressible viscous fluid over a flat
sheet when the flow is started impulsively from rest and at the same
time, the sheet is suddenly stretched in its own plane with a velocity
proportional to the distance from the stagnation point. The partial
differential equations governing the laminar boundary layer forced
convection flow are non-dimensionalised using semi-similar
transformations and then solved numerically using an implicit finitedifference
scheme known as the Keller-box method. Results
pertaining to the flow and heat transfer characteristics are computed
for all dimensionless time, uniformly valid in the whole spatial region
without any numerical difficulties. Analytical solutions are also
obtained for both small and large times, respectively representing the
initial unsteady and final steady state flow and heat transfer.
Numerical results indicate that the velocity ratio parameter is found
to have a significant effect on skin friction and heat transfer rate at
the surface. Furthermore, it is exposed that there is a smooth
transition from the initial unsteady state flow (small time solution) to
the final steady state (large time solution).
Abstract: A physically based, spatially-distributed water quality model is being developed to simulate spatial and temporal distributions of material transport in the Great Lakes Watersheds of the U.S. Multiple databases of meteorology, land use, topography, hydrography, soils, agricultural statistics, and water quality were used to estimate nonpoint source loading potential in the study watersheds. Animal manure production was computed from tabulations of animals by zip code area for the census years of 1987, 1992, 1997, and 2002. Relative chemical loadings for agricultural land use were calculated from fertilizer and pesticide estimates by crop for the same periods. Comparison of these estimates to the monitored total phosphorous load indicates that both point and nonpoint sources are major contributors to the total nutrient loads in the study watersheds, with nonpoint sources being the largest contributor, particularly in the rural watersheds. These estimates are used as the input to the distributed water quality model for simulating pollutant transport through surface and subsurface processes to Great Lakes waters. Visualization and GIS interfaces are developed to visualize the spatial and temporal distribution of the pollutant transport in support of water management programs.
Abstract: By incorporating a prey refuge, this paper proposes new discrete Leslie–Gower predator–prey systems with and without Allee effect. The existence of fixed points are established and the stability of fixed points are discussed by analyzing the modulus of characteristic roots.
Abstract: We present the results of a case study aiming to assess the reflection of the tourism community in the Web and its usability to propose new ways to communicate visually. The wealth of information contained in the Web and the clear facilities to communicate personals points of view makes of the social web a new space of exploration. In this way, social web allow the sharing of information between communities with similar interests. However, the tourism community remains unexplored as is the case of the information covered in travel stories. Along the Web, we find multiples sites allowing the users to communicate their experiences and personal points of view of a particular place of the world. This cultural heritage is found in multiple documents, usually very little supplemented with photos, so they are difficult to explore due to the lack of visual information. This paper explores the possibility of analyzing travel stories to display them visually on maps and generate new knowledge such as patterns of travel routes. This way, travel narratives published in electronic formats can be very important especially to the tourism community because of the great amount of knowledge that can be extracted. Our approach is based on the use of a Geoparsing Web Service to extract geographic coordinates from travel narratives in order to draw the geo-positions and link the documents into a map image.
Abstract: The importance for manipulating an incorporated
scaffold and directing cell behaviors is well appreciated for tissue
engineering. Here, we developed newly nano-topographic oxidized
silicon nanosponges capable of being various chemical modifications
to provide much insight into the fundamental biology of how cells
interact with their surrounding environment in vitro. A wet etching
technique is exerted to allow us fabricated the silicon nanosponges in a
high-throughput manner. Furthermore, various organo-silane
chemicals enabled self-assembled on the surfaces by vapor deposition.
We have found that Chinese hamster ovary (CHO) cells displayed
certain distinguishable morphogenesis, adherent responses, and
biochemical properties while cultured on these chemical modified
nano-topographic structures in compared with the planar oxidized
silicon counterparts, indicating that cell behaviors can be influenced
by certain physical characteristic derived from nano-topography in
addition to the hydrophobicity of contact surfaces crucial for cell
adhesion and spreading. Of particular, there were predominant
nano-actin punches and slender protrusions formed while cells were
cultured on the nano-topographic structures. This study shed potential
applications of these nano-topographic biomaterials for controlling
cell development in tissue engineering or basic cell biology research.
Abstract: Purpose of this paper is two-folded. At first it explains
the major problems that are causing stagnation in brownfield
redevelopment. In addition, these problems given the context of the
present multi-actor built environment are becoming more complex to
observe. Therefore, this paper suggests also a prospective decisionmaking
approach that is the most appropriate to observe and react on
the given stagnation problems. Such an approach should be regarded
as prescriptive-interactive decision-making approach, a barely
established branch. This approach should offer models that have
prescriptive as well as an interactive component enabling them to
successfully cope with the multi-actor environment. Overall, this
paper provides up-to-date insight on the brownfield stagnation by
gradually introducing the nowadays major problems and offers a
prospective decision-making approach how these problems could be
tackled.
Abstract: The effect of notch depth on the elastic new strainconcentration
factor (SNCF) of rectangular bars with single edge Unotch
under combined loading is studied here. The finite element
method (FEM) and super position technique are used in the current
study. This new SNCF under combined loading of static tension and
pure bending has been defined under triaxial stress state. The
employed specimens have constant gross thickness of 16.7 mm and
net section thickness varied to give net-to-gross thickness ratio ho/Ho
from 0.2 to 0.95. The results indicated that the elastic SNCF for
combined loading increases with increasing notch depth up to ho/Ho =
0.7 and sharply decreases with increasing notch depth. It is also
indicated that the elastic SNCF of combined loading is greater than
that of pure bending and less than that of the static tension for 0.2 ≤
ho/Ho ≤ 0.7. However, the elastic SNCF of combined loading is the
elastic SNCF for static tension and less than that of pure bending for
shallow notches (i.e. 0.8 ≤ ho/Ho ≤ 0.95).
Abstract: Food and fibre production in arid and semi-arid regions has emerged as one of the major challenges for various socio-economic and political reasons such as the food security and self-sufficiency. Productive use of the renewable water resources has risen on top ofthe decision-making agenda. For this reason, efficient operation and maintenance of modern irrigation and drainage schemes become part and parcel and indispensible reality in agricultural policy making arena. The aim of this paper is to investigate the complexity of operating and maintaining such schemes, mainly focussing on challenges which enhance and opportunities that impedsustainable food and fibre production. The methodology involved using secondary data complemented byroutine observations and stakeholders views on issues that influence the O&M in the Dez command area. The SPSS program was used as an analytical framework for data analysis and interpretation.Results indicate poor application efficiency in most croplands, much of which is attributed to deficient operation of conveyance and distribution canals. These in turn, are reportedly linked to inadequate maintenance of the pumping stations and hydraulic structures like turnouts,flumes and other control systems particularly in the secondary and tertiary canals. Results show that the aforementioned deficiencies have been the major impediment to establishing regular flow toward the farm gates which subsequently undermine application efficiency and tillage operationsat farm level. Results further show that accumulative impact of such deficiencies has been the major causes of poorcrop yield and quality that deem production system in these croplands uneconomic. Results further show that the present state might undermine the sustainability of agricultural system in the command area. The overall conclusion being that present water management is unlikely to be responsive to challenges that the sector faces. And in the absence of coherent measures to shift the status quo situation in favour of more productive resource use, it would be hard to fulfil the objectives of the National Economic and Socio-cultural Development Plans.
Abstract: In the present communication, stochastic comparison
of a series (parallel) system having heterogeneous components with
random lifetimes and series (parallel) system having homogeneous
exponential components with random lifetimes has been studied.
Further, conditions under which such a comparison is possible has
been established.
Abstract: According to investigating impact of complexity of
stereoscopic frame pairs on stereoscopic video coding and
transmission, a new rate control algorithm is presented. The proposed
rate control algorithm is performed on three levels: stereoscopic group
of pictures (SGOP) level, stereoscopic frame (SFrame) level and
frame level. A temporal-spatial frame complexity model is firstly
established, in the bits allocation stage, the frame complexity, position
significance and reference property between the left and right frames
are taken into account. Meanwhile, the target buffer is set according to
the frame complexity. Experimental results show that the proposed
method can efficiently control the bitrates, and it outperforms the fixed
quantization parameter method from the rate distortion perspective,
and average PSNR gain between rate-distortion curves (BDPSNR) is
0.21dB.
Abstract: Mega urban transport projects (MUTPs) are
increasingly being used in urban environments to ameliorate the
problem of congestion. However, a number of problems with regard
to mega projects have been identified. In particular the seemingly
institutionalised over estimation of economic benefits and persistent
cost over runs, could mean that the wrong projects are selected, and
that the projects that are selected cost more than they should. Studies
to date have produced a number of solutions to these problems,
perhaps most notably, the various methods for the inclusion of the
private sector in project provision. However the problems have
shown significant intractability in the face of these solutions. This
paper provides a detailed examination of some of the problems
facing mega projects and then examines Foucault-s theory of
'governmentality' as a possible frame of analysis which might shed
light on the intractability of the problems that have been identified,
through an identification of the art of government in which MUTPs
occur.
Abstract: Scheduling algorithm is a key technology in satellite
switching system with input-buffer. In this paper, a new scheduling
algorithm and its realization are proposed. Based on Crossbar
switching fabric, the algorithm adopts serial scheduling strategy and
adjusts the output port arbitrating strategy for the better equity of every
port. Consequently, it increases the matching probability. The
algorithm can greatly reduce the scheduling delay and cell loss rate.
The analysis and simulation results by OPNET show that the proposed
algorithm has the better performance than others in average delay and
cell loss rate, and has the equivalent complexity. On the basis of these
results, the hardware realization and simulation based on FPGA are
completed, which validate the feasibility of the new scheduling
algorithm.
Abstract: This paper presents a modified version of the
maximum urgency first scheduling algorithm. The maximum
urgency algorithm combines the advantages of fixed and dynamic
scheduling to provide the dynamically changing systems with
flexible scheduling. This algorithm, however, has a major
shortcoming due to its scheduling mechanism which may cause a
critical task to fail. The modified maximum urgency first scheduling
algorithm resolves the mentioned problem. In this paper, we propose
two possible implementations for this algorithm by using either
earliest deadline first or modified least laxity first algorithms for
calculating the dynamic priorities. These two approaches are
compared together by simulating the two algorithms. The earliest
deadline first algorithm as the preferred implementation is then
recommended. Afterwards, we make a comparison between our
proposed algorithm and maximum urgency first algorithm using
simulation and results are presented. It is shown that modified
maximum urgency first is superior to maximum urgency first, since it
usually has less task preemption and hence, less related overhead. It
also leads to less failed non-critical tasks in overloaded situations.
Abstract: An experiment was conducted under controlled
conditions to study the effect of water extract of leaves, shoots and
roots of either Sisymbrium irio L. =SISIR and/or Descurainia
sophia (L.) Schur =DESSO on the germination and primary growth
of wheat. A split-split plot experiment in CRD with three
replications was used. The main plots were the type of weed: i.e.
SISIR and DESSO and the sub-plots were type of organ: i.e. leaf,
stem and root and, the sub-sub plots were concentration of the
water extract of each organ of the weeds: i.e. 0, 2, 4 and 8 % w/v.
The plant materials were cut in 2-3 cm pieces and then were
ground in a blender. The crushed materials were weighed
according to experimental protocol and the final volume was
reached to 100 ml in distilled water in dark bottles. All bottles were
put on a shaker for 24 hours. The solutions were filtered by muslin
cloth. Whatman paper, 9 cm in diameter, were put in petri dishes
and twenty seeds of wheat were put on it and 5 ml distilled water
or water extract of weeds were added to each petri dish. All petri
dishes were put in constant temperature of 15 0C incubator.
The results showed that the SISIR water extract had a greater
inhibitory effects on germination and primary growth of wheat
than those of DESSO water extract. The water extracts of the
leaves of both weeds had the greatest inhibitory effects on
germination and primary growth of wheat, compared to those of
stems and roots. Increasing the concentration of water extract of
leaves, stems and roots of both weeds up to 8 % caused the greatest
inhibitory effects to wheat and reduced the germination rate and
primary growth of it linearly.
Abstract: We developed a new method based on quasimolecular
modeling to simulate the cavity flow in three cavity
shapes: rectangular, half-circular and bucket beer in cgs units. Each
quasi-molecule was a group of particles that interacted in a fashion
entirely analogous to classical Newtonian molecular interactions.
When a cavity flow was simulated, the instantaneous velocity vector
fields were obtained by using an inverse distance weighted
interpolation method. In all three cavity shapes, fluid motion was
rotated counter-clockwise. The velocity vector fields of the three
cavity shapes showed a primary vortex located near the upstream
corners at time t ~ 0.500 s, t ~ 0.450 s and t ~ 0.350 s, respectively.
The configurational kinetic energy of the cavities increased as time
increased until the kinetic energy reached a maximum at time t ~
0.02 s and, then, the kinetic energy decreased as time increased. The
rectangular cavity system showed the lowest kinetic energy, while
the half-circular cavity system showed the highest kinetic energy.
The kinetic energy of rectangular, beer bucket and half-circular
cavities fluctuated about stable average values 35.62 x 103, 38.04 x
103 and 40.80 x 103 ergs/particle, respectively. This indicated that the
half-circular shapes were the most suitable shape for a shrimp pond
because the water in shrimp pond flows best when we compared with
rectangular and beer bucket shape.
Abstract: Due to the fact that in the new century customers tend
to express globally increasing demands, networks of interconnected
businesses have been established in societies and the management of
such networks seems to be a major key through gaining competitive
advantages. Supply chain management encompasses such managerial
activities. Within a supply chain, a critical role is played by quality.
QFD is a widely-utilized tool which serves the purpose of not only
bringing quality to the ultimate provision of products or service
packages required by the end customer or the retailer, but it can also
initiate us into a satisfactory relationship with our initial customer;
that is the wholesaler. However, the wholesalers- cooperation is
considerably based on the capabilities that are heavily dependent on
their locations and existing circumstances. Therefore, it is undeniable
that for all companies each wholesaler possesses a specific
importance ratio which can heavily influence the figures calculated in
the House of Quality in QFD. Moreover, due to the competitiveness
of the marketplace today, it-s been widely recognized that
consumers- expression of demands has been highly volatile in
periods of production. Apparently, such instability and proneness to
change has been very tangibly noticed and taking it into account
during the analysis of HOQ is widely influential and doubtlessly
required. For a more reliable outcome in such matters, this article
demonstrates the application viability of Analytic Network Process
for considering the wholesalers- reputation and simultaneously
introduces a mortality coefficient for the reliability and stability of
the consumers- expressed demands in course of time. Following to
this, the paper provides further elaboration on the relevant
contributory factors and approaches through the calculation of such
coefficients. In the end, the article concludes that an empirical
application is needed to achieve broader validity.
Abstract: The main goal of data mining is to extract accurate, comprehensible and interesting knowledge from databases that may be considered as large search spaces. In this paper, a new, efficient type of Genetic Algorithm (GA) called uniform two-level GA is proposed as a search strategy to discover truly interesting, high-level prediction rules, a difficult problem and relatively little researched, rather than discovering classification knowledge as usual in the literatures. The proposed method uses the advantage of uniform population method and addresses the task of generalized rule induction that can be regarded as a generalization of the task of classification. Although the task of generalized rule induction requires a lot of computations, which is usually not satisfied with the normal algorithms, it was demonstrated that this method increased the performance of GAs and rapidly found interesting rules.
Abstract: This paper is an exploration of the conceptual
confusion between E-learning and M-learning particularly in Africa.
Section I provides a background to the development of E-learning
and M-learning. Section II focuses on the conceptual analysis as it
applies to Africa. It is with an investigative and expansive mind that
this paper is elaborated to respond to a profound question of the
suitability of the concepts in a particular era in Africa. The aim of this
paper is therefore to shed light on which concept best suits the unique
situation of Africa in the era of cloud computing.
Abstract: The area of Project Risk Management (PRM) has
been extensively researched, and the utilization of various tools and
techniques for managing risk in several industries has been
sufficiently reported. Formal and systematic PRM practices have
been made available for the construction industry. Based on such
body of knowledge, this paper tries to find out the global picture of
PRM practices and approaches with the help of a survey to look into
the usage of PRM techniques and diffusion of software tools, their
level of maturity, and their usefulness in the construction sector.
Results show that, despite existing techniques and tools, their usage is
limited: software tools are used only by a minority of respondents
and their cost is one of the largest hurdles in adoption. Finally, the
paper provides some important guidelines for future research
regarding quantitative risk analysis techniques and suggestions for
PRM software tools development and improvement.
Abstract: Simulation is a very helpful and valuable work tool in
manufacturing. It can be used in industrial field allowing the
system`s behavior to be learnt and tested. Simulation provides a low
cost, secure and fast analysis tool. It also provides benefits, which
can be reached with many different system configurations. Topics to
be discussed include: Applications, Modeling, Validating, Software
and benefits of simulation. This paper provides a comprehensive
literature review on research efforts in simulation.