Abstract: Key management represents a major and the most
sensitive part of cryptographic systems. It includes key generation,
key distribution, key storage, and key deletion. It is also considered
the hardest part of cryptography. Designing secure cryptographic
algorithms is hard, and keeping the keys secret is much harder.
Cryptanalysts usually attack both symmetric and public key
cryptosystems through their key management. We introduce a
protocol to exchange cipher keys over insecure communication
channel. This protocol is based on public key cryptosystem,
especially elliptic curve cryptosystem. Meanwhile, it tests the cipher
keys and selects only the good keys and rejects the weak one.
Abstract: This study shows the effect of carbon towards
molybdenum carbide alloy when exposed to Microwave. This
technique is also known as Microwave Induced Alloying (MIA) for
the preparation of molybdenum carbide. In this study ammonium
heptamolybdate solution and carbon black powder were
heterogeneously mixed and exposed to microwave irradiation for 2
minutes. The effect on amount of carbon towards the produced alloy
on morphological and oxidation states changes during microwave is
presented. In this experiment, it is expected carbon act as a reducing
agent with the ratio 2:7 molybdenum to carbon as the optimum for
the production of molybdenum carbide alloy. All the morphological
transformations and changes in this experiment were followed and
characterized using X-Ray Diffraction and FESEM.
Abstract: Copolymerization of ethylene with 1-hexene was
carried out using two ansa-fluorenyl titanium derivative complexes.
The substituent effect on the catalytic activity, monomer reactivity
ratio and polymer property was investigated. It was found that the
presence of t-Bu groups on fluorenyl ring exhibited remarkable
catalytic activity and produced polymer with high molecular weight.
However, these catalysts produce polymer with narrow molecular
weight distribution, indicating the characteristic of single-site
metallocene catalyst. Based on 13C NMR, we can observe that
monomer reactivity ratio was affected by catalyst structure. The rH
values of complex 2 were lower than that of complex 1 which might
be result from the higher steric hindrance leading to a reduction of 1-
hexene insertion step.
Abstract: Within the new world order, the term “crisis" is nowadays familiar to companies. Organizations are experiencing conditions which are surprising, uncertain, often adverse and usually unstable. The companies, who grasp the importance of transformation within the information age, have felt the need to develop modern methods to achieve the ability to thrive despite severe shocks. Through strategically managing human resource and developing appropriate elements of human resource system, companies can be assured for resolving the crisis. In this paper the role of HR system on resolving crisis has been evaluated. To help accomplish this, an insight on previous strategic HRM literature and an introduction to the elements and relationship within HR systems has been presented. It also reviews different attitude around resilience in literature. It continues by reviewing three elements central to developing an organization-s capacity for crisis resolving and it will demonstrate how designing proper elements of HR system can lead the organizations to possess the ability for passing through crisis. Finally it will evaluate an Iranian Insurance organization in case of one of the three central elements (specific cognitive ability) and observe how successful they were on developing an effective HR system to be ready for facing crisis.
Abstract: This paper investigates the effect of product substitution in the single-period 'newsboy-type' problem in a fuzzy environment. It is supposed that the single-period problem operates under uncertainty in customer demand, which is described by imprecise terms and modelled by fuzzy sets. To perform this analysis, we consider the fuzzy model for two-item with upward substitution. This upward substitutability is reasonable when the products can be stored according to certain attribute levels such as quality, brand or package size. We show that the explicit consideration of this substitution opportunity increase the average expected profit. Computational study is performed to observe the benefits of product's substitution.
Abstract: Increasing demand on the performance of Subsea
Production Systems (SPS) suggests a need for more detailed
investigation of fluid behavior taking place in subsea equipment.
Complete CFD cool down analyses of subsea equipment are very
time demanding. The objective of this paper is to investigate a
Locked CFD approach, which enables significant reduction of the
computational time and at the same time maintains sufficient
accuracy during thermal cool down simulations. The result
comparison of a dead leg simulation using the Full CFD and the three
LCFD-methods confirms the validity of the locked flow field
assumption for the selected case. For the tested case the LCFD
simulation speed up by factor of 200 results in the absolute thermal
error of 0.5 °C (3% relative error), speed up by factor of 10 keeps the
LCFD results within 0.1 °C (0.5 % relative error) comparing to the
Full CFD.
Abstract: Methanol-to-olefins coupled with transformation of
coal or natural gas to methanol gives an interesting and promising way
to produce ethylene and propylene. To investigate solid concentration
in gas-solid fluidized bed for methanol-to-olefins process catalyzed by
SAPO-34, a cold model experiment system is established in this paper.
The system comprises a gas distributor in a 300mm internal diameter
and 5000mm height acrylic column, the fiber optic probe system and
series of cyclones. The experiments are carried out at ambient
conditions and under different superficial gas velocity ranging from
0.3930m/s to 0.7860m/s and different initial bed height ranging from
600mm to 1200mm. The effects of radial distance, axial distance,
superficial gas velocity, initial bed height on solid concentration in the
bed are discussed. The effects of distributor shape and porosity on
solid concentration are also discussed. The time-averaged solid
concentration profiles under different conditions are obtained.
Abstract: The purpose of our study was to compare spontaneous
re-epithelisation characteristics versus assisted re-epithelisation. In
order to assess re-epithelisation of the injured skin, we have imagined
and designed a burn wound model on Wistar rat skin. Our aim was to
create standardised, easy reproducible and quantifiable skin lesions
involving entire epidermis and superficial dermis. We then have
applied the above mentioned therapeutic strategies to compare
regeneration of epidermis and dermis, local and systemic parameter
changes in different conditions. We have enhanced the reepithelisation
process under a moist atmosphere of a polyurethane
wound dress modified with helium non-thermal plasma, and with the
aid of direct cold-plasma treatment respectively. We have followed
systemic parameters change: hematologic and biochemical
parameters, and local features: oxidative stress markers and histology
of skin in the above mentioned conditions. Re-epithelisation is just a
part of the skin regeneration process, which recruits cellular
components, with the aid of epidermal and dermal interaction via
signal molecules.
Abstract: This paper presents a method to estimate load profile
in a multiple power flow solutions for every minutes in 24 hours per
day. A method to calculate multiple solutions of non linear profile is
introduced. The Power System Simulation/Engineering (PSS®E) and
python has been used to solve the load power flow. The result of this
power flow solutions has been used to estimate the load profiles for
each load at buses using Independent Component Analysis (ICA)
without any knowledge of parameter and network topology of the
systems. The proposed algorithm is tested with IEEE 69 test bus
system represents for distribution part and the method of ICA has
been programmed in MATLAB R2012b version. Simulation results
and errors of estimations are discussed in this paper.
Abstract: Controlled modification of appropriate sharpness for
nanotips is of paramount importance to develop novel materials and
functional devices at a nanometer resolution. Herein, we present a
reliable and unique strategy of laser irradiation enhanced
physicochemical etching to manufacture super sharp tungsten tips
with reproducible shape and dimension as well as high yields
(~80%). The corresponding morphology structure evolution of
tungsten tips and laser-tip interaction mechanisms were
systematically investigated and discussed using field emission
scanning electron microscope (SEM) and physical optics statistics
method with different fluences under 532 nm laser irradiation. This
work paves the way for exploring more accessible metallic tips
applications with tunable apex diameter and aspect ratio, and,
furthermore, facilitates the potential sharpening enhancement
technique for other materials used in a variety of nanoscale devices.
Abstract: This paper introduces an intelligent system, which can be applied in the monitoring of vehicle speed using a single camera. The ability of motion tracking is extremely useful in many automation problems and the solution to this problem will open up many future applications. One of the most common problems in our daily life is the speed detection of vehicles on a highway. In this paper, a novel technique is developed to track multiple moving objects with their speeds being estimated using a sequence of video frames. Field test has been conducted to capture real-life data and the processed results were presented. Multiple object problems and noisy in data are also considered. Implementing this system in real-time is straightforward. The proposal can accurately evaluate the position and the orientation of moving objects in real-time. The transformations and calibration between the 2D image and the actual road are also considered.
Abstract: The aim of study was to evaluate pressure distribution characteristics of the elastic textile bandages using two instrumental techniques: a prototype Instrument and a load Transference. The prototype instrument which simulates shape of real leg has pressure sensors which measure bandage pressure. Using this instrument, the results show that elastic textile bandages presents different pressure distribution characteristics and none produces a uniform distribution around lower limb.
The load transference test procedure is used to determine whether a relationship exists between elastic textile bandage structure and pressure distribution characteristics. The test procedure assesses degree of load, directly transferred through a textile when loads series are applied to bandaging surface. A range of weave fabrics was produced using needle weaving machine and a sewing technique. A textile bandage was developed with optimal characteristics far superior pressure distribution than other bandages. From results, we find that theoretical pressure is not consistent exactly with practical pressure. It is important in this study to make a practical application for specialized nurses in order to verify the results and draw useful conclusions for predicting the use of this type of elastic band.
Abstract: This paper presents the cepstral and trispectral
analysis of a speech signal produced by normal men, men with
defective audition (deaf, deep deaf) and others affected by
tracheotomy, the trispectral analysis based on parametric methods
(Autoregressive AR) using the fourth order cumulant. These
analyses are used to detect and compare the pitches and the formants
of corresponding voiced sounds (vowel \a\, \i\ and \u\). The first
results appear promising, since- it seems after several experimentsthere
is no deformation of the spectrum as one could have supposed
it at the beginning, however these pathologies influenced the two
characteristics:
The defective audition influences to the formants contrary to the
tracheotomy, which influences the fundamental frequency (pitch).
Abstract: An increasingly dynamic and complex environment poses huge challenges to production enterprises, especially with regards to logistics. The Logistic Operating Curve Theory, developed at the Institute of Production Systems and Logistics (IFA) of the Leibniz University of Hanover, is a recognized approach to describing logistic interactions, nevertheless, it reaches its limits when it comes to the dynamic aspects. In order to facilitate a timely and optimal Logistic Positioning a method is developed for quickly and reliably identifying dynamic processing states.
Abstract: This paper introduces a technique for simulating a
single-server exponential queuing system. The technique called the
Q-Simulator is a computer program which can simulate the effect of
traffic intensity on all system average quantities given the arrival
and/or service rates. The Q-Simulator has three phases namely: the
formula based method, the uncontrolled simulation, and the
controlled simulation. The Q-Simulator generates graphs (crystal
solutions) for all results of the simulation or calculation and can be
used to estimate desirable average quantities such as waiting times,
queue lengths, etc.
Abstract: The dramatic effect of information technology on
society is undeniable. In education, it is evident in the use of terms
like active learning, blended learning, electronic learning and mobile
learning (ubiquitous learning). This study explores the perceptions of
54 learners in a higher education institution regarding the use of
mobile devices in a third year module. Using semi-structured
interviews, it was found that mobile devices had a positive impact on
learner motivation, engagement and enjoyment. It also improved the
consistency of learning material, and the convenience and flexibility
(anywhere, anytime) of learning. User-interfacelimitation, bandwidth
and cognitive overload, however, were of concern. The use of cloud
based resources like Youtube and Google Docs, through mobile
devices, positively influenced learner perceptions, making them
prosumers (both consumers and producers) of education content.
Abstract: This paper presents a numerical investigation of the
unsteady flow around an American 19th century vertical-axis
windmill: the Stevens & Jolly rotor, patented on April 16, 1895. The
computational approach used is based on solving the complete
transient Reynolds-Averaged Navier-Stokes (t-RANS) equations: a
full campaign of numerical simulation has been performed using the
k-ω SST turbulence model. Flow field characteristics have been
investigated for several values of tip speed ratio and for a constant
unperturbed free-stream wind velocity of 6 m/s, enabling the study of
some unsteady flow phenomena in the rotor wake. Finally, the global
power generated from the windmill has been determined for each
simulated angular velocity, allowing the calculation of the rotor
power-curve.
Abstract: Increasing concerns over climate change have limited
the liberal usage of available energy technology options. India faces
a formidable challenge to meet its energy needs and provide adequate
energy of desired quality in various forms to users in sustainable
manner at reasonable costs. In this paper, work carried out with an
objective to study the role of various energy technology options
under different scenarios namely base line scenario, high nuclear
scenario, high renewable scenario, low growth and high growth rate
scenario. The study has been carried out using Model for Energy
Supply Strategy Alternatives and their General Environmental
Impacts (MESSAGE) model which evaluates the alternative energy
supply strategies with user defined constraints on fuel availability,
environmental regulations etc. The projected electricity demand, at
the end of study period i.e. 2035 is 500490 MWYr. The model
predicted the share of the demand by Thermal: 428170 MWYr,
Hydro: 40320 MWYr, Nuclear: 14000 MWYr, Wind: 18000 MWYr
in the base line scenario. Coal remains the dominant fuel for
production of electricity during the study period. However, the
import dependency of coal increased during the study period. In
baseline scenario the cumulative carbon dioxide emissions upto 2035
are about 11,000 million tones of CO2. In the scenario of high nuclear
capacity the carbon dioxide emissions reduced by 10 % when nuclear
energy share increased to 9 % compared to 3 % in baseline scenario.
Similarly aggressive use of renewables reduces 4 % of carbon
dioxide emissions.
Abstract: A wideband 2-1-1 cascaded ΣΔ modulator with a
single-bit quantizer in the two first stages and a 4-bit quantizer in the
final stage is developed. To reduce sensitivity of digital-to-analog
converter (DAC) nonlinearities in the feedback of the last stage,
dynamic element matching (DEM) is introduced. This paper presents
two modelling approaches: The first is MATLAB description and the
second is VHDL-AMS modelling of the proposed architecture and
exposes some high-level-simulation results allowing a behavioural
study. The detail of both ideal and non-ideal behaviour modelling are
presented. Then, the study of the effect of building blocks
nonidealities is presented; especially the influences of nonlinearity,
finite operational amplifier gain, amplifier slew rate limitation and
capacitor mismatch. A VHDL-AMS description presents a good
solution to predict system-s performances and can provide sensitivity
curves giving the impact of nonidealities on the system performance.
Abstract: This study assesses the vulnerability of Bulgarian
agriculture to drought using the WINISAREG model and seasonal
standard precipitation index SPI(2) for the period 1951-2004. This
model was previously validated for maize on soils of different water
holding capacity (TAW) in various locations. Simulations are
performed for Plovdiv, Stara Zagora and Sofia. Results relative to
Plovdiv show that in soils of large TAW (180 mm m-1) net irrigation
requirements (NIRs) range 0-40 mm in wet years and 350-380 mm in
dry years. In soils of small TAW (116 mm m-1), NIRs reach 440 mm
in the very dry year. NIRs in Sofia are about 80 mm smaller. Rainfed
maize is associated with great yield variability (29%