Abstract: This paper aims to address the new trend of social
commerce as electronic commerce leverages Web 2.0 technologies
and online social media. The infusions of new technologies on the
World Wide Web connect users in their homes and workplaces,
thus transforming social formations and business transactions. An
in-depth study of the growth and success of a social commerce site,
Facebook was conducted. The investigation is finalized with a triad
relational model which reflects socioeconomic life in the Internet
today. The following three concepts work jointly to form a global
community that has already started to take the place of traditional
commerce and socialization: Web 2.0 technology, E-commerce,
and online social media. A discussion of the research findings
indicates that social commerce networks are sustainable because of
the various incentives given to users as they collaborate with others
regardless of their identity and location. The focus of this article is
to increase understanding on quickly developing Web 2.0 based
social media and their subsequent effects on the emerging social
commerce.
Abstract: Landscape connectivity combines a description of the
physical structure of the landscape with special species- response to
that structure, which forms the theoretical background of applying
landscape connectivity principles in the practices of landscape
planning and design. In this study, a residential development project in
the southern United States was used to explore the meaning of
landscape connectivity and its application in town planning. The vast
rural landscape in the southern United States is conspicuously
characterized by the hedgerow trees or groves. The patchwork
landscape of fields surrounded by high hedgerows is a traditional and
familiar feature of the American countryside. Hedgerows are in effect
linear strips of trees, groves, or woodlands, which are often critical
habitats for wildlife and important for the visual quality of the
landscape. Based on geographic information system (GIS) and
statistical analysis (FRAGSTAT), this study attempts to quantify the
landscape connectivity characterized by hedgerows in south Alabama
where substantial areas of authentic hedgerow landscape are being
urbanized due to the ever expanding real estate industry and high
demand for new residential development. The results of this study
shed lights on how to balance the needs of new urban development and
biodiversity conservation by maintaining a higher level of landscape
connectivity, thus will inform the design intervention.
Abstract: In nature, electromagnetic fields always appear like
atmosphere static electric field, the earth's static magnetic field and
the wide-rang frequency electromagnetic field caused by lightening.
However, besides natural electromagnetic fields (EMF), today human
beings are mostly exposed to artificial electromagnetic fields due to
technology progress and outspread use of electrical devices. To
evaluate nuisance of EMF, it is necessary to know field intensity for
every frequency which appears and compare it with allowed values.
Low frequency EMF-s around transmission and distribution lines are
time-varying quasi-static electromagnetic fields which have
conservative component of low frequency electrical field caused by
charges and eddy component of low frequency magnetic field caused
by currents. Displacement current or field delay are negligible, so
energy flow in quasi-static EMF involves diffusion, analog like heat
transfer. Electrical and magnetic field can be analyzed separately.
This paper analysis the numerical calculations in ELF-400 software
of EMF in distribution substation in shopping center. Analyzing the
results it is possible to specify locations exposed to the fields and
give useful suggestion to eliminate electromagnetic effect or reduce it
on acceptable level within the non-ionizing radiation norms and
norms of protection from EMF.
Abstract: A suspension bridge is the most suitable type of structure for a long-span bridge due to rational use of structural materials. Increased deformability, which is conditioned by appearance of the elastic and kinematic displacements, is the major disadvantage of suspension bridges. The problem of increased kinematic displacements under the action of non-symmetrical load can be solved by prestressing. The prestressed suspension bridge with the span of 200 m was considered as an object of investigations. The cable truss with the cross web was considered as the main load carrying structure of the prestressed suspension bridge. The considered cable truss was optimized by 47 variable factors using Genetic algorithm and FEM program ANSYS. It was stated, that the maximum total displacements are reduced up to 29.9% by using of the cable truss with the rational characteristics instead of the single cable in the case of the worst situated load.
Abstract: The tray/multi-tray distillation process is a topic that
has been investigated to great detail over the last decade by many
teams such as Jubran et al. [1], Adhikari et al. [2], Mowla et al. [3],
Shatat et al. [4] and Fath [5] to name a few. A significant amount of
work and effort was spent focusing on modeling and/simulation of
specific distillation hardware designs. In this work, we have focused
our efforts on investigating and gathering experimental data on
several engineering and design variables to quantify their influence
on the yield of the multi-tray distillation process. Our goals are to
generate experimental performance data to bridge some existing gaps
in the design, engineering, optimization and theoretical modeling
aspects of the multi-tray distillation process.
Abstract: This paper deals with a novel approach of power
transformers diagnostics. This approach identifies the exact location
and the range of a fault in the transformer and helps to reduce
operation costs related to handling of the faulty transformer, its
disassembly and repair. The advantage of the approach is a
possibility to simulate healthy transformer and also all faults, which
can occur in transformer during its operation without its
disassembling, which is very expensive in practice. The approach is
based on creating frequency dependent impedance of the transformer
by sweep frequency response analysis measurements and by 3D FE
parametrical modeling of the fault in the transformer. The parameters
of the 3D FE model are the position and the range of the axial short
circuit. Then, by comparing the frequency dependent impedances of
the parametrical models with the measured ones, the location and the
range of the fault is identified. The approach was tested on a real
transformer and showed high coincidence between the real fault and
the simulated one.
Abstract: Engineered nanoparticles’ usage rapidly increased in
various applications in the last decade due to their unusual properties.
However, there is an ever increasing concern to understand their
toxicological effect in human health. Particularly, metal and metal
oxide nanoparticles have been used in various sectors including
biomedical, food and agriculture. But their impact on human health is
yet to be fully understood. In this present investigation, we assessed
the toxic effect of engineered nanoparticles (ENPs) including Ag,
MgO and Co3O4 nanoparticles (NPs) on human mesenchymal stem
cells (hMSC) adopting cell viability and cellular morphological
changes as tools The results suggested that silver NPs are more toxic
than MgO and Co3O4NPs. The ENPs induced cytotoxicity and
nuclear morphological changes in hMSC depending on dose. The cell
viability decreases with increase in concentration of ENPs. The
cellular morphology studies revealed that ENPs damaged the cells.
These preliminary findings have implications for the use of these
nanoparticles in food industry with systematic regulations.
Abstract: In this paper, a two factor scheme is proposed to
generate cryptographic keys directly from biometric data, which
unlike passwords, are strongly bound to the user. Hash value of the
reference iris code is used as a cryptographic key and its length
depends only on the hash function, being independent of any other
parameter. The entropy of such keys is 94 bits, which is much higher
than any other comparable system. The most important and distinct
feature of this scheme is that it regenerates the reference iris code by
providing a genuine iris sample and the correct user password. Since
iris codes obtained from two images of the same eye are not exactly
the same, error correcting codes (Hadamard code and Reed-Solomon
code) are used to deal with the variability. The scheme proposed here
can be used to provide keys for a cryptographic system and/or for
user authentication. The performance of this system is evaluated on
two publicly available databases for iris biometrics namely CBS and
ICE databases. The operating point of the system (values of False
Acceptance Rate (FAR) and False Rejection Rate (FRR)) can be set
by properly selecting the error correction capacity (ts) of the Reed-
Solomon codes, e.g., on the ICE database, at ts = 15, FAR is 0.096%
and FRR is 0.76%.
Abstract: Video watermarking is usually considered as watermarking of a set of still images. In frame-by-frame watermarking approach, each video frame is seen as a single watermarked image, so collusion attack is more critical in video watermarking. If the same or redundant watermark is used for embedding in every frame of video, the watermark can be estimated and then removed by watermark estimate remodolulation (WER) attack. Also if uncorrelated watermarks are used for every frame, these watermarks can be washed out with frame temporal filtering (FTF). Switching watermark system or so-called SS-N system has better performance against WER and FTF attacks. In this system, for each frame, the watermark is randomly picked up from a finite pool of watermark patterns. At first SS-N system will be surveyed and then a new collusion attack for SS-N system will be proposed using a new algorithm for separating video frame based on watermark pattern. So N sets will be built in which every set contains frames carrying the same watermark. After that, using WER attack in every set, N different watermark patterns will be estimated and removed later.
Abstract: In contrast to existing methods which do not take into account multiconnectivity in a broad sense of this term, we develop mathematical models and highly effective combination (BIEM and FDM) numerical methods of calculation of stationary and quasi-stationary temperature field of a profile part of a blade with convective cooling (from the point of view of realization on PC). The theoretical substantiation of these methods is proved by appropriate theorems. For it, converging quadrature processes have been developed and the estimations of errors in the terms of A.Ziqmound continuity modules have been received. For visualization of profiles are used: the method of the least squares with automatic conjecture, device spline, smooth replenishment and neural nets. Boundary conditions of heat exchange are determined from the solution of the corresponding integral equations and empirical relationships. The reliability of designed methods is proved by calculation and experimental investigations heat and hydraulic characteristics of the gas turbine first stage nozzle blade.
Abstract: Until recently, energy security and climate change
were considered separate issues to be dealt with by policymakers.
The two issues are now converging, challenging the security and
climate communities to develop a better understanding of how to deal
with both issues simultaneously. Although Egypt is not a major
contributor to the world's total GHG emissions, it is particularly
vulnerable to the potential effects of global climate change such as
rising sea levels and changed patterns of rainfall in the Nile Basin.
Climate change is a major threat to sustainable growth and
development in Egypt, and the achievement of the Millennium
Development Goals. Egypt-s capacity to respond to the challenges of
climate instability will be expanded by improving overall resilience,
integrating climate change goals into sustainable development
strategies, increasing the use of modern energy systems with reduced
carbon intensity, and strengthening international initiatives. This
study seeks to establish a framework for considering the complex and
evolving links between energy security and climate change,
applicable to Egypt.
Abstract: This paper proposes a new algebraic scheme to design a PID controller for higher order linear time invariant continuous systems. Modified PSO (MPSO) based model order formulation techniques have applied to obtain the effective formulated second order system. A controller is tuned to meet the desired performance specification by using pole-zero cancellation method. Proposed PID controller is attached with both higher order system and formulated second order system. The closed loop response is observed for stabilization process and compared with general PSO based formulated second order system. The proposed method is illustrated through numerical example from literature.
Abstract: Because of architectural condition and structure application, sometimes mass source and stiffness source are not coincidence, and the structure is irregular. The structure is also might be asymmetric as an asymmetric bracing in plan which leads to unbalance distribution of stiffness or because of unbalance distribution of the mass. Both condition lead to eccentricity and torsion in the structure. The deficiency of ordinary code to evaluate the performance of steel structures against earthquake has been caused designing based on performance level or capacity spectrum be used. By using the mentioned methods it is possible to design a structure that its behavior against different earthquakes be predictive. In this article 5- story buildings with different percentage of asymmetric which is because of stiffness changes have been designed. The static and dynamic nonlinear analysis under three acceleration recording has been done. Finally performance level of the structure has been evaluated.
Abstract: IT consultants often take over an important role as an
interface between technological, organizational and managerial
structures. As a result, the services offered are in many cases
assigned to different disciplines which can cause a lack of
transparency on the market for consulting services. However, not all
consulting products are suitable for every company because of
different frameworks and business processes. In this context the
questions arises as to what consulting products are currently offered
and how they can be compared as well as how the market for IT
consulting services is structured on the supply side. The presented
study aims to shed light on the IT consulting market by giving an
overview of the current structure of the supply-side for IT consulting
services as well as proposing a categorization of the currently
available consulting services (consulting fields) in order to provide a
theoretical background for the empirical study. Apart from these
theoretical considerations, the empirical results of field surveys on
the Austrian IT consulting market are presented and analyzed.
Abstract: A co-generation system in automobile can improve
thermal efficiency of vehicle in some degree. The waste heat from the
engine exhaust and coolant is still attractive energy source that reaches
around 60% of the total energy converted from fuel. To maximize the
effectiveness of heat exchangers for recovering the waste heat, it is
vital to select the most suitable working fluid for the system, not to
mention that it is important to find the optimum design for the heat
exchangers. The design of heat exchanger is out of scoop of this study;
rather, the main focus has been on the right selection of working fluid
for the co-generation system. Simulation study was carried out to find
the most suitable working fluid that can allow the system to achieve
the optimum efficiency in terms of the heat recovery rate and thermal
efficiency.
Abstract: This paper presents the benchmarking results and
performance evaluation of differentclustersbuilt atthe National Center
for High-Performance Computingin Taiwan. Performance of
processor, memory subsystem andinterconnect is a critical factor in the
overall performance of high performance computing platforms. The
evaluation compares different system architecture and software
platforms. Most supercomputer used HPL to benchmark their system
performance, in accordance with the requirement of the TOP500 List.
In this paper we consider system memory access factors that affect
benchmark performance, such as processor and memory
performance.We hope these works will provide useful information for
future development and construct cluster system.
Abstract: Cybercrime is now becoming a big challenge in Nigeria apart from the traditional crime. Inability to identify perpetrators is one of the reasons for the growing menace. This paper proposes a design for monitoring internet users’ activities in order to curbing cybercrime. It requires redefining the operations of Internet Service Providers (ISPs) which will now mandate users to be authenticated before accessing the internet. In implementing this work which can be adapted to a larger scale, a virtual router application is developed and configured to mimic a real router device. A sign-up portal is developed to allow users to register with the ISP. The portal asks for identification information which will include bio-data and government issued identification data like National Identity Card number, et cetera. A unique username and password are chosen by the user to enable access to the internet which will be used to reference him to an Internet Protocol Address (IP Address) of any system he uses on the internet and thereby associating him to any criminal act related to that IP address at that particular time. Questions such as “What happen when another user knows the password and uses it to commit crime?” and other pertinent issues are addressed.
Abstract: Electron multiplying charge coupled devices (EMCCDs) have revolutionized the world of low light imaging by introducing on-chip multiplication gain based on the impact ionization effect in the silicon. They combine the sub-electron readout noise with high frame rates. Signal-to-noise Ratio (SNR) is an important performance parameter for low-light-level imaging systems. This work investigates the SNR performance of an EMCCD operated in Non-inverted Mode (NIMO) and Inverted Mode (IMO). The theory of noise characteristics and operation modes is presented. The results show that the SNR of is determined by dark current and clock induced charge at high gain level. The optimum SNR performance is provided by an EMCCD operated in NIMO in short exposure and strong cooling applications. In contrast, an IMO EMCCD is preferable.
Abstract: To study the impact of the inter-module ventilation (IMV) on the space station, the Computational Fluid Dynamic (CFD) model under the influence of IMV, the mathematical model, boundary conditions and calculation method are established and determined to analyze the influence of IMV on cabin air flow characteristics and velocity distribution firstly; and then an integrated overall thermal mathematical model of the space station is used to consider the impact of IMV on thermal management. The results show that: the IMV has a significant influence on the cabin air flow, the flowrate of IMV within a certain range can effectively improve the air velocity distribution in cabin, if too much may lead to its deterioration; IMV can affect the heat deployment of the different modules in space station, thus affecting its thermal management, the use of IMV can effectively maintain the temperature levels of the different modules and help the space station to dissipate the waste heat.
Abstract: This study carried out in order to investigate the
effects of salinity on carbon isotope discrimination (Δ) of shoots and
roots of four sugar beet cultivars (cv) including Madison (British
origin) and three Iranian culivars (7233-P12, 7233-P21 and 7233-P29).
Plants were grown in sand culture medium in greenhouse conditions.
Plants irrigated with saline water (tap water as control, 50 mM, 150
mM, 250 mM and 350 mM of NaCl + CaCl2 in 5 to 1 molar ratio)
from 4 leaves stage for 16 weeks. Carbon isotope discrimination
significantly decreased with increasing salinity. Significant
differences of Δ between shoot and root were observed in all cvs and
all levels of salinity. Madison cv showed lower Δ in shoot and root
than other three cvs at all levels of salinity expect control, but cv
7233-P29 had significantly higher Δ values at saline conditions of 150
mM and above. Therefore, Δ might be applicable, as a useful tool, for
study of salinity tolerance of sugar beet genotypes.