Abstract: IEEE has recently incorporated CCMP protocol to provide robust security to IEEE 802.11 wireless LANs. It is found that CCMP has been designed with a weak nonce construction and transmission mechanism, which leads to the exposure of initial counter value. This weak construction of nonce renders the protocol vulnerable to attacks by intruders. This paper presents how the initial counter can be pre-computed by the intruder. This vulnerability of counter block value leads to pre-computation attack on the counter mode encryption of CCMP. The failure of the counter mode will result in the collapse of the whole security mechanism of 802.11 WLAN.
Abstract: Based on a non-linear single track model which
describes the dynamics of vehicle, an optimal path planning strategy
is developed. Real time optimization is used to generate reference
control values to allow leading the vehicle alongside a calculated lane
which is optimal for different objectives such as energy consumption,
run time, safety or comfort characteristics. Strict mathematic
formulation of the autonomous driving allows taking decision on
undefined situation such as lane change or obstacle avoidance. Based
on position of the vehicle, lane situation and obstacle position, the
optimization problem is reformulated in real-time to avoid the
obstacle and any car crash.
Abstract: In today's complex global environment, emotional intelligence in educational administrations encompasses self-regard that is formed to utilize communication effectiveness. The paper is undertaken to understand the relationship between managers- emotional intelligence especially self-regard and employees to improve communication effectiveness in educational administrations of Iran. Data (N = 145) for this study were collected through questionnaires that participants were managers and employees educational administrations of Iran. The aim of this paper assess the emotional intelligence especially self-regard of managers and employees and its relationship with communication effectiveness in educational administrations of Iran. This paper explained self-regard that has a high relationship with communication especially communication effectiveness. Self-regard plays an important role in communication effectiveness. Individuals with high self-regard tend to have higher emotional intelligence and this action lead to improve communication effectiveness. The result of the paper shows a strong correspondence between self-regard and communication effectiveness in educational administrations.
Abstract: In this work we numerically examine structures which
could confine light in nanometer areas. A system consisting of two silicon disks with in plane separation of a few tens of nanometers has
been studied first. The normalized unitless effective mode volume, Veff, has been calculated for the two lowest whispering gallery mode resonances. The effective mode volume is reduced significantly as the gap between the disks decreases. In addition, the effect of the substrate is also studied. In that case, Veff of approximately the same
value as the non-substrate case for a similar two disk system can be
obtained by using disks almost twice as thick. We also numerically examine a structure consisting of a circular slot waveguide which is formed into a silicon disk resonator. We show that the proposed structure could have high Q resonances thus raising the belief that it
is a very promising candidate for optical interconnects applications.
The study includes several numerical calculations for all the geometric parameters of the structure. It also includes numerical simulations of the coupling between a waveguide and the proposed
disk resonator leading to a very promising conclusion about its applicability.
Abstract: In its attempt to offer new ways into autonomy for a
large population of disabled people, assistive technology has largely
been inspired by robotics engineering. Recent human-like robots
carry new hopes that it seems to us necessary to analyze by means of
a specific theory of anthropomorphism. We propose to distinguish a
functional anthropomorphism which is the one of actual wheelchairs
from a structural anthropomorphism based on a mimicking of human
physiological systems. If functional anthropomorphism offers the
main advantage of eliminating the physiological systems
interdependence issue, the highly link between the robot for disabled
people and their human-built environment would lead to privilege in
the future the anthropomorphic structural way. In this future
framework, we highlight a general interdependence principle : any
partial or local structural anthropomorphism generates new
anthropomorphic needs due to the physiological systems
interdependency, whose effects can be evaluated by means of
specific anthropomorphic criterions derived from a set theory-based
approach of physiological systems.
Abstract: Mobile IP has been developed to provide the
continuous information network access to mobile users. In IP-based
mobile networks, location management is an important component of
mobility management. This management enables the system to track
the location of mobile node between consecutive communications. It
includes two important tasks- location update and call delivery.
Location update is associated with signaling load. Frequent updates
lead to degradation in the overall performance of the network and the
underutilization of the resources. It is, therefore, required to devise
the mechanism to minimize the update rate. Mobile IPv6 (MIPv6)
and Hierarchical MIPv6 (HMIPv6) have been the potential
candidates for deployments in mobile IP networks for mobility
management. HMIPv6 through studies has been shown with better
performance as compared to MIPv6. It reduces the signaling
overhead traffic by making registration process local. In this paper,
we present performance analysis of MIPv6 and HMIPv6 using an
analytical model. Location update cost function is formulated based
on fluid flow mobility model. The impact of cell residence time, cell
residence probability and user-s mobility is investigated. Numerical
results are obtained and presented in graphical form. It is shown that
HMIPv6 outperforms MIPv6 for high mobility users only and for low
mobility users; performance of both the schemes is almost equivalent
to each other.
Abstract: Recently, X. Ge and J. Qian investigated some relations between higher mathematics scores and calculus scores (resp. linear algebra scores, probability statistics scores) for Chinese university students. Based on rough-set theory, they established an information system S = (U,CuD,V, f). In this information system, higher mathematics score was taken as a decision attribute and calculus score, linear algebra score, probability statistics score were taken as condition attributes. They investigated importance of each condition attribute with respective to decision attribute and strength of each condition attribute supporting decision attribute. In this paper, we give further investigations for this issue. Based on the above information system S = (U, CU D, V, f), we analyze the decision rules between condition and decision granules. For each x E U, we obtain support (resp. strength, certainty factor, coverage factor) of the decision rule C —>x D, where C —>x D is the decision rule induced by x in S = (U, CU D, V, f). Results of this paper gives new analysis of on higher mathematics scores for Chinese university students, which can further lead Chinese university students to raise higher mathematics scores in Chinese graduate student entrance examination.
Abstract: The purpose of this article is to analyze economic and
political tendencies of development of integration processes with
different developing level and speed on the Eurasian space, by considering two organizations at the region – Eurasian Economic
Community and Shanghai Cooperation Organization, by considering the interests of participations in organizations of Russia and China as
a global powers and Kazakhstan as a leader among the Central Asian
countries. This article investigates what certain goals Eurasian
countries (especially Russia, Kazakhstan and China) are waiting from integration within the SCO and the EurAsEC, linking the process
with the theories of regional integration. After European debt crisis it is more topically to research the integration within the specific
region's conditions.
Abstract: Web-based technologies have created numerous
opportunities for electronic word-of-mouth (eWOM) communication.
There are many factors that affect customer adoption and decisionmaking
process. However, only a few researches focus on some
factors such as the membership time of forum and propensity to trust.
Using a discrete-time event simulation to simulate a diffusion model
along with a consumer decision model, the study shows the effect of
each factor on adoption of opinions on on-line discussion forum. The
purpose of this study is to examine the effect of factor affecting
information adoption and decision making process. The model is
constructed to test quantitative aspects of each factor. The simulation
study shows the membership time and the propensity to trust has an
effect on information adoption and purchasing decision. The result of
simulation shows that the longer the membership time in the
communities and the higher propensity to trust could lead to the
higher demand rates because consumers find it easier and faster to
trust the person in the community and then adopt the eWOM. Other
implications for both researchers and practitioners are provided.
Abstract: Solid fuel transient burning behavior under oxidizer
gas flow is numerically investigated. It is done using analysis of the
regression rate responses to the imposed sudden and oscillatory
variation at inflow properties. The conjugate problem is considered
by simultaneous solution of flow and solid phase governing
equations to compute the fuel regression rate. The advection
upstream splitting method is used as flow computational scheme in
finite volume method. The ignition phase is completely simulated to
obtain the exact initial condition for response analysis. The results
show that the transient burning effects which lead to the combustion
instabilities and intermittent extinctions could be observed in solid
fuels as the solid propellants.
Abstract: Concrete strength evaluated from compression tests
on cores is affected by several factors causing differences from the
in-situ strength at the location from which the core specimen was
extracted. Among the factors, there is the damage possibly occurring
during the drilling phase that generally leads to underestimate the
actual in-situ strength. In order to quantify this effect, in this study
two wide datasets have been examined, including: (i) about 500 core
specimens extracted from Reinforced Concrete existing structures,
and (ii) about 600 cube specimens taken during the construction of
new structures in the framework of routine acceptance control. The
two experimental datasets have been compared in terms of
compression strength and specific weight values, accounting for the
main factors affecting a concrete property, that is type and amount of
cement, aggregates' grading, type and maximum size of aggregates,
water/cement ratio, placing and curing modality, concrete age. The
results show that the magnitude of the strength reduction due to
drilling damage is strongly affected by the actual properties of
concrete, being inversely proportional to its strength. Therefore, the
application of a single value of the correction coefficient, as generally
suggested in the technical literature and in structural codes, appears
inappropriate. A set of values of the drilling damage coefficient is
suggested as a function of the strength obtained from compressive
tests on cores.
Abstract: Sub-prime mortgage crisis which began in the US is
regarded as the most economic crisis since the Great Depression in the
early 20th century. Especially, hidden problems on efficient operation
of a business were disclosed at a time and many financial institutions
went bankrupt and filed for court receivership. The collapses of
physical market lead to bankruptcy of manufacturing and construction
businesses. This study is to analyze dynamic efficiency of construction
businesses during the five years at the turn of the global financial
crisis. By discovering the trend and stability of efficiency of a
construction business, this study-s objective is to improve
management efficiency of a construction business in the
ever-changing construction market. Variables were selected by
analyzing corporate information on top 20 construction businesses in
Korea and analyzed for static efficiency in 2008 and dynamic
efficiency between 2006 and 2010. Unlike other studies, this study
succeeded in deducing efficiency trend and stability of a construction
business for five years by using the DEA/Window model. Using the
analysis result, efficient and inefficient companies could be figured
out. In addition, relative efficiency among DMU was measured by
comparing the relationship between input and output variables of
construction businesses. This study can be used as a literature to
improve management efficiency for companies with low efficiency
based on efficiency analysis of construction businesses.
Abstract: Participation in sporting activities can lead to injury.
Sport injuries have been widely studied in many sports including the
more extreme categories of aquatic board sports. Kitesurfing is a
relatively new water surface action sport, and has not yet been
widely studied in terms of injuries and stress on the body. The aim of
this study was to get information about which injuries that are most
common among kitesurfing participants, where they occur, and their
causes. Injuries were studied using an international open web
questionnaire (n=206).
The results showed that many respondents reported injuries, in
total 251 injuries to knee (24%), ankle (17%), trunk (16%) and
shoulders (10%), often sustained while doing jumps and tricks
(40%). Among the reported injuries were joint injuries (n=101),
muscle/tendon damages (n=47), wounds and cuts (n=36) and bone
fractures (n=28). Also environmental factors and equipment can
influence the risk of injury, or the extent of injury in a hazardous
situation. Conclusively, the information from this retrospective study
supports earlier studies in terms of prevalence and site of injuries.
Suggestively, this information should be used for to build a
foundation of knowledge about the sport for development of
applications for physical training and product development.
Abstract: Electrocardiogram (ECG) segmentation is necessary to help reduce the time consuming task of manually annotating ECG's. Several algorithms have been developed to segment the ECG automatically. We first review several of such methods, and then present a new single lead segmentation method based on Adaptive piecewise constant approximation (APCA) and Piecewise derivative dynamic time warping (PDDTW). The results are tested on the QT database. We compared our results to Laguna's two lead method. Our proposed approach has a comparable mean error, but yields a slightly higher standard deviation than Laguna's method.
Abstract: Flows over a harmonically oscillating NACA 0012
airfoil are simulated here using a two-dimensional, unsteady,
incompressibleNavier-Stokes solver.Both pure-plunging and
pitching-plunging combined oscillations are considered at a Reynolds
number of 5000. Special attention is paid to the vortex shedding and
interaction mechanism of the motions. For all the simulations
presented here, the reduced frequency (k) is fixed at a value of 2.5
and plunging amplitude (h) is selected to be in the range of 0.2-0.5.
The simulation results show that the interaction mechanism between
the leading and trailing edge vortices has a decisive effect on the
values of the resulting thrust and propulsive efficiency.
Abstract: Rule Discovery is an important technique for mining knowledge from large databases. Use of objective measures for discovering interesting rules lead to another data mining problem, although of reduced complexity. Data mining researchers have studied subjective measures of interestingness to reduce the volume of discovered rules to ultimately improve the overall efficiency of KDD process. In this paper we study novelty of the discovered rules as a subjective measure of interestingness. We propose a hybrid approach that uses objective and subjective measures to quantify novelty of the discovered rules in terms of their deviations from the known rules. We analyze the types of deviation that can arise between two rules and categorize the discovered rules according to the user specified threshold. We implement the proposed framework and experiment with some public datasets. The experimental results are quite promising.
Abstract: An advanced Monte Carlo simulation method, called Subset Simulation (SS) for the time-dependent reliability prediction for underground pipelines has been presented in this paper. The SS can provide better resolution for low failure probability level with efficient investigating of rare failure events which are commonly encountered in pipeline engineering applications. In SS method, random samples leading to progressive failure are generated efficiently and used for computing probabilistic performance by statistical variables. SS gains its efficiency as small probability event as a product of a sequence of intermediate events with larger conditional probabilities. The efficiency of SS has been demonstrated by numerical studies and attention in this work is devoted to scrutinise the robustness of the SS application in pipe reliability assessment. It is hoped that the development work can promote the use of SS tools for uncertainty propagation in the decision-making process of underground pipelines network reliability prediction.
Abstract: A large number of chemical, bio-chemical and pollution-control processes use heterogeneous fixed-bed reactors. The use of finite hollow cylindrical catalyst pellets can enhance conversion levels in such reactors. The absence of the pellet core can significantly lower the diffusional resistance associated with the solid phase. This leads to a better utilization of the catalytic material, which is reflected in the higher values for the effectiveness factor, leading ultimately to an enhanced conversion level in the reactor. It is however important to develop a rigorous heterogeneous model for the reactor incorporating the two-dimensional feature of the solid phase owing to the presence of the finite hollow cylindrical catalyst pellet. Presently, heterogeneous models reported in the literature invariably employ one-dimension solid phase models meant for spherical catalyst pellets. The objective of the paper is to present a rigorous model of the fixed-bed reactors containing finite hollow cylindrical catalyst pellets. The reaction kinetics considered here is the widely used Michaelis–Menten kinetics for the liquid-phase bio-chemical reactions. The reaction parameters used here are for the enzymatic degradation of urea. Results indicate that increasing the height to diameter ratio helps to improve the conversion level. On the other hand, decreasing the thickness is apparently not as effective. This could however be explained in terms of the higher void fraction of the bed that causes a smaller amount of the solid phase to be packed in the fixed-bed bio-chemical reactor.
Abstract: Historical monuments as architectural heritage are,
economically and culturally, considered one of the key aspects for
modern communities. Cultural heritage represents a country-s
national identity and pride and maintains and enriches that country-s
culture. Therefore, conservation of the monuments remained from
our ancestors requires everybody-s serious and unremitting effort.
Conservation, renewal, restoration, and technical study of cultural
and historical matters are issues which have a special status among
various forms of art and science in the present century and this is due
to two reasons: firstly, progress of humankind in this century has
created a factor called environmental pollution which not only has
caused new destructive processes of cultural/historical monuments
but also has accelerated the previous destructive processes by several
times, and secondly, the rapid advance of various sciences, especially
chemistry, has lead to the contribution of new methods and materials
to this significant issue.
Abstract: This paper deals optimized model to investigate the
effects of peak current, pulse on time and pulse off time in EDM performance on material removal rate of titanium alloy utilizing copper tungsten as electrode and positive polarity of the electrode. The experiments are carried out on Ti6Al4V. Experiments were
conducted by varying the peak current, pulse on time and pulse off time. A mathematical model is developed to correlate the influences of these variables and material removal rate of workpiece. Design of
experiments (DOE) method and response surface methodology
(RSM) techniques are implemented. The validity test of the fit and adequacy of the proposed models has been carried out through
analysis of variance (ANOVA). The obtained results evidence that as
the material removal rate increases as peak current and pulse on time
increases. The effect of pulse off time on MRR changes with peak ampere. The optimum machining conditions in favor of material removal rate are verified and compared. The optimum machining
conditions in favor of material removal rate are estimated and verified with proposed optimized results. It is observed that the developed model is within the limits of the agreeable error (about
4%) when compared to experimental results. This result leads to desirable material removal rate and economical industrial machining to optimize the input parameters.