Abstract: Despite the fact that B2c eCommerce has become
important in numerous economies, its adoption varies from country to
country. This paper aims to identify the factors affecting (enabling or
inhibiting) B2c eCommerce and to determine their quantitative
impact on the diffusion of online sales across countries. A dynamic
panel model analyzing the relationship between 13 factors
(Macroeconomic, Demographic, Socio-Cultural, Infrastructural and
Offer related) stemming from a complete literature analysis and the
B2c eCommerce value in 45 countries over 9 years has been
developed. Having a positive correlation coefficient, GDP, mobile
penetration, Internet user penetration and credit card penetration
resulted as enabling drivers of the B2c eCommerce value across
countries, whereas, having a negative correlation coefficient,equal
distribution of income and the development of traditional retailing
network act as inhibiting factors.
Abstract: The development of competences and practical
capacities of students is getting an important incidence into the
guidelines of the European Higher Education Area (EHEA). The
methodology applied in this work is based on the education through
directed resolution of practical cases. All cases are related to
professional tasks that the students will have to develop in their
future career. The method is intended to form the necessary
competences of students of the Marine Engineering and Maritime
Transport Degree in the matter of “Physics".
The experience was applied in the course of 2011/2012. Students
were grouped, and a practical task was assigned to them, that should
be developed and solved within the team. The aim was to realize
students learning by three ways: their own knowledge, the
contribution of their teammates and the teacher's direction. The
results of the evaluation were compared with those obtained
previously by the traditional teaching method.
Abstract: In this paper, the experimental design of using the
Taguchi method is employed to optimize the processing parameters in
the plasma arc surface hardening process. The processing parameters
evaluated are arc current, scanning velocity and carbon content of
steel. In addition, other significant effects such as the relation between
processing parameters are also investigated. An orthogonal array,
signal-to-noise (S/N) ratio and analysis of variance (ANOVA) are
employed to investigate the effects of these processing parameters.
Through this study, not only the hardened depth increased and surface
roughness improved, but also the parameters that significantly affect
the hardening performance are identified. Experimental results are
provided to verify the effectiveness of this approach.
Abstract: Stuck-pipe in drilling operations is one of the most
pressing and expensive problems in the oil industry. This paper
describes a computational simulation and an experimental study of
the hydrodynamic vibrator, which may be used for liquidation of
stuck-pipe problems during well drilling. The work principle of the
vibrator is based upon the known phenomena of Vortex Street of
Karman and the resulting generation of vibrations. We will discuss
the computational simulation and experimental investigations of
vibrations in this device. The frequency of the vibration parameters
has been measured as a function of the wide range Reynolds Number.
The validity of the computational simulation and of the assumptions
on which it is based has been proved experimentally. The
computational simulation of the vibrator work and its effectiveness
was carried out using FLUENT software. The research showed high
degree of congruence with the results of the laboratory tests and
allowed to determine the effect of the granular material features upon
the pipe vibration in the well. This study demonstrates the potential
of using the hydrodynamic vibrator in a well drilling system.
Abstract: In this study, optimization is carried out to find the optimized design of a foam-filled column for the best Specific Energy Absorption (SEA) and Crush Force Efficiency (CFE). In order to maximize SEA, the optimization gives the value of 2.3 for column thickness and 151.7 for foam length. On the other hand to maximize CFE, the optimization gives the value of 1.1 for column thickness and 200 for foam length. Finite Element simulation is run by using this value and the SEA and CFE obtained 1237.76 J/kg and 0.92.
Abstract: A decomposition of a graph G is a collection ψ of
graphs H1,H2, . . . , Hr of G such that every edge of G belongs
to exactly one Hi. If each Hi is either an induced path in G,
then ψ is called an induced acyclic path decomposition of G and
if each Hi is a (induced) cycle in G then ψ is called a (induced)
cycle decomposition of G. The minimum cardinality of an induced
acyclic path decomposition of G is called the induced acyclic path
decomposition number of G and is denoted by ¤Çia(G). Similarly
the cyclic decomposition number ¤Çc(G) is defined. In this paper we
begin an investigation of these parameters.
Abstract: The NGN (Next Generation Network), which can
provide advanced multimedia services over an all-IP based network, has been the subject of much attention for years. While there have
been tremendous efforts to develop its architecture and protocols, especially for IMS, which is a key technology of the NGN, it is far
from being widely deployed. However, efforts to create an advanced
signaling infrastructure realizing many requirements have resulted in a
large number of functional components and interactions between those
components. Thus, the carriers are trying to explore effective ways to
deploy IMS while offering value-added services. As one such
approach, we have proposed a self-organizing IMS. A self-organizing
IMS enables IMS functional components and corresponding physical
nodes to adapt dynamically and automatically based on situation such
as network load and available system resources while continuing IMS
operation. To realize this, service continuity for users is an important
requirement when a reconfiguration occurs during operation. In this
paper, we propose a mechanism that will provide service continuity to
users and focus on the implementation and describe performance
evaluation in terms of number of control signaling and processing time
during reconfiguration
Abstract: This paper proposes an innovative approach for the Connection Admission Control (CAC) problem. Starting from an abstract network modelling, the CAC problem is formulated in a technology independent fashion allowing the proposed concepts to be applied to any wireless and wired domain. The proposed CAC is decoupled from the other Resource Management procedures, but cooperates with them in order to guarantee the desired QoS requirements. Moreover, it is based on suitable performance measurements which, by using proper predictors, allow to forecast the domain dynamics in the next future. Finally, the proposed CAC control scheme is based on a feedback loop aiming at maximizing a suitable performance index accounting for the domain throughput, whilst respecting a set of constraints accounting for the QoS requirements.
Abstract: The morphological parameter of a thin film surface
can be characterized by power spectral density (PSD) functions
which provides a better description to the topography than the RMS
roughness and imparts several useful information of the surface
including fractal and superstructure contributions. Through the
present study Nanoparticle copper/carbon composite films were
prepared by co-deposition of RF-Sputtering and RF-PECVD method
from acetylene gas and copper target. Surface morphology of thin
films is characterized by using atomic force microscopy (AFM). The
Carbon content of our films was obtained by Rutherford Back
Scattering (RBS) and it varied from .4% to 78%. The power values of
power spectral density (PSD) for the AFM data were determined by
the fast Fourier transform (FFT) algorithms. We investigate the effect
of carbon on the roughness of thin films surface. Using such
information, roughness contributions of the surface have been
successfully extracted.