Abstract: Attitude control of aerospace system with liquid containers may face to a problem associate with fuel sloshing. The sloshing phenomena can degrade the stability of control system and in the worst case, interaction between the attitude control system and fuel vibration leading to resonance. In this paper, a full process of nonlinear dynamic modeling of an aerospace launch vehicle with fuel sloshing is given. Then, a new control system based on model reference adaptive filter is proposed and its algorithm is extracted. This controller implemented on the main attitude control system. Finally, numerical simulation of nonlinear model and control system is carried out to examine the performance of the new controller. Results of simulations show that the inconvenient effects of the fuel sloshing by augmenting this control system are reduced and attitude control system performs, satisfactorily.
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: In this paper, an improvement of PDLZW implementation
with a new dictionary updating technique is proposed. A
unique dictionary is partitioned into hierarchical variable word-width
dictionaries. This allows us to search through dictionaries in parallel.
Moreover, the barrel shifter is adopted for loading a new input string
into the shift register in order to achieve a faster speed. However,
the original PDLZW uses a simple FIFO update strategy, which is
not efficient. Therefore, a new window based updating technique
is implemented to better classify the difference in how often each
particular address in the window is referred. The freezing policy
is applied to the address most often referred, which would not be
updated until all the other addresses in the window have the same
priority. This guarantees that the more often referred addresses would
not be updated until their time comes. This updating policy leads
to an improvement on the compression efficiency of the proposed
algorithm while still keep the architecture low complexity and easy
to implement.
Abstract: In this paper, we analyze the effect of noise in a single- ended input differential amplifier working at high frequencies. Both extrinsic and intrinsic noise are analyzed using time domain method employing techniques from stochastic calculus. Stochastic differential equations are used to obtain autocorrelation functions of the output noise voltage and other solution statistics like mean and variance. The analysis leads to important design implications and suggests changes in the device parameters for improved noise characteristics of the differential amplifier.
Abstract: The effect of teaching method on learning
assistance Dunn Review .The study, to compare the effects of
collaboration on teaching mathematics learning courses, including
writing, science, experimental girl students by other methods of
teaching basic first paid and the amount of learning students
methods have been trained to cooperate with other students with
other traditional methods have been trained to compare. The
survey on 100 students in Tehran that using random sampling ¬
cluster of girl students between the first primary selections was
performed. Considering the topic of semi-experimental research
methods used to practice the necessary information by
questionnaire, examination questions by the researcher, in
collaboration with teachers and view authority in this field and
related courses that teach these must have been collected.
Research samples to test and control groups were divided.
Experimental group and control group collaboration using
traditional methods of mathematics courses, including writing and
experimental sciences were trained. Research results using
statistical methods T is obtained in two independent groups show
that, through training assistance will lead to positive results and
student learning in comparison with traditional methods, will
increase also led to collaboration methods increase skills to solve
math lesson practice, better understanding and increased skill
level of students in practical lessons such as science and has been
writing.
Abstract: The inherent complexity in nowadays- business
environments is forcing organizations to be attentive to the dynamics
in several fronts. Therefore, the management of technological
innovation is continually faced with uncertainty about the future.
These issues lead to a need for a systemic perspective, able to analyze
the consequences of interactions between different factors. The field
of technology foresight has proposed methods and tools to deal with
this broader perspective. In an attempt to provide a method to analyze
the complex interactions between events in several areas, departing
from the identification of the most strategic competencies, this paper
presents a methodology based on the Delphi method and Quality
Function Deployment. This methodology is applied in a sheet metal
processing equipment manufacturer, as a case study.
Abstract: This article is an extension and a practical application
approach of Wheeler-s NEBIC theory (Net Enabled Business
Innovation Cycle). NEBIC theory is a new approach in IS research
and can be used for dynamic environment related to new technology.
Firms can follow the market changes rapidly with support of the IT
resources. Flexible firms adapt their market strategies, and respond
more quickly to customers changing behaviors. When every leading
firm in an industry has access to the same IT resources, the way that
these IT resources are managed will determine the competitive
advantages or disadvantages of firm. From Dynamic Capabilities
Perspective and from newly introduced NEBIC theory by Wheeler,
we know that only IT resources cannot deliver customer value but
good configuration of those resources can guarantee customer value
by choosing the right emerging technology, grasping the right
economic opportunities through business innovation and growth. We
found evidences in literature that SOA (Service Oriented
Architecture) is a promising emerging technology which can deliver
the desired economic opportunity through modularity, flexibility and
loose-coupling. SOA can also help firms to connect in network which
can open a new window of opportunity to collaborate in innovation
and right kind of outsourcing. There are many articles and research
reports indicates that failure rate in outsourcing is very high but at the
same time research indicates that successful outsourcing projects
adds tangible and intangible benefits to the service consumer.
Business executives and policy makers in the west should not afraid
of outsourcing but they should choose the right strategy through the
use of emerging technology to significantly reduce the failure rate in
outsourcing.
Abstract: There exists a strong correlation between efficient project management and competitive advantage for organizations. Therefore, organizations are striving to standardize and assess the rigor of their project management processes and capabilities i.e. project management maturity. Researchers and standardization organizations have developed several project management maturity models (PMMMs) to assess project management maturity of the organizations. This study presents a critical evaluation of some of the leading PMMMs against OPM3® in a multitude of ways to look at which PMMM is the most comprehensive model - which could assess most aspects of organizations and also help the organizations in gaining competitive advantage over competitors. After a detailed morphological analysis of the models, it is concluded that OPM3® is the most promising maturity model that can really provide a competitive advantage to the organizations due to its unique approach of assessment and improvement strategies.
Abstract: Vernonia divergens Benth., commonly known as
“Insulin Plant” (Fam: Asteraceae) is a potent sugar killer. Locally the
leaves of the plant, boiled in water are successfully administered to a
large number of diabetic patients. The present study evaluates the
putative anti-diabetic ingredients, isolated from the in vivo and in
vitro grown plantlets of V. divergens for their antimicrobial and
anticancer activities. Sterilized explants of nodal segments were
cultured on MS (Musashige and Skoog, 1962) medium in presence of
different combinations of hormones. Multiple shoots along with
bunch of roots were regenerated at 1mg l-1 BAP and 0.5 mg l-1 NAA.
Micro-plantlets were separated and sub-cultured on the double
strength (2X) of the above combination of hormones leading to
increased length of roots and shoots. These plantlets were
successfully transferred to soil and survived well in nature. The
ethanol extract of plantlets from both in vivo & in vitro sources were
prepared in soxhlet extractor and then concentrated to dryness under
reduced pressure in rotary evaporator. Thus obtainedconcentrated
extracts showed significant inhibitory activity against gram
negative bacteria like Escherichia coli and Pseudomonas
aeruginosa but no inhibition was found against gram positive
bacteria. Further, these ethanol extracts were screened for in vitro
percentage cytotoxicity at different time periods (24 h, 48 h and 72 h)
of different dilutions. The in vivo plant extract inhibited the growth of
EAC mouse cell lines in the range of 65, 66, 78, and 88% at 100, 50,
25 & 12.5μg mL-1 but at 72 h of treatment. In case of the extract of in
vitro origin, the inhibition was found against EAC cell lines even at
48h. During spectrophotometric scanning, the extracts exhibited
different maxima (ʎ) - four peaks in in vitro extracts as against single
in in vivo preparation suggesting the possible change in the nature of
ingredients during micropropagation through tissue culture
techniques.
Abstract: With optimized bandwidth and latency discrepancy ratios, Node Gain Scores (NGSs) are determined and used as a basis for shaping the max-heap overlay. The NGSs - determined as the respective bandwidth-latency-products - govern the construction of max-heap-form overlays. Each NGS is earned as a synergy of discrepancy ratio of the bandwidth requested with respect to the estimated available bandwidth, and latency discrepancy ratio between the nodes and the source node. The tree leads to enhanceddelivery overlay multicasting – increasing packet delivery which could, otherwise, be hindered by induced packet loss occurring in other schemes not considering the synergy of these parameters on placing the nodes on the overlays. The NGS is a function of four main parameters – estimated available bandwidth, Ba; individual node's requested bandwidth, Br; proposed node latency to its prospective parent (Lp); and suggested best latency as advised by source node (Lb). Bandwidth discrepancy ratio (BDR) and latency discrepancy ratio (LDR) carry weights of α and (1,000 - α ) , respectively, with arbitrary chosen α ranging between 0 and 1,000 to ensure that the NGS values, used as node IDs, maintain a good possibility of uniqueness and balance between the most critical factor between the BDR and the LDR. A max-heap-form tree is constructed with assumption that all nodes possess NGS less than the source node. To maintain a sense of load balance, children of each level's siblings are evenly distributed such that a node can not accept a second child, and so on, until all its siblings able to do so, have already acquired the same number of children. That is so logically done from left to right in a conceptual overlay tree. The records of the pair-wise approximate available bandwidths as measured by a pathChirp scheme at individual nodes are maintained. Evaluation measures as compared to other schemes – Bandwidth Aware multicaSt architecturE (BASE), Tree Building Control Protocol (TBCP), and Host Multicast Tree Protocol (HMTP) - have been conducted. This new scheme generally performs better in terms of trade-off between packet delivery ratio; link stress; control overhead; and end-to-end delays.
Abstract: Design of Converter transformer insulation is a major
challenge. The insulation of these transformers is stressed by both
AC and DC voltages. Particle contamination is one of the major
problems in insulation structures, as they generate partial discharges
leading it to major failure of insulation. Similarly corona discharges
occur in transformer insulation. This partial discharge due to particle
movement / corona formation in insulation structure under different
voltage wave shapes, are different. In the present study, UHF
technique is adopted to understand the discharge activity and could
be realized that the characteristics of UHF signal generated under
low and high fields are different. In the case of corona generated
signal, the frequency content of the UHF sensor output lies in the
range 0.3-1.2 GHz and is not much varied except for its increase in
magnitude of discharge with the increase in applied voltage. It is
realized that the current signal injected due to partial
discharges/corona is about 4ns duration measured for first one half
cycle. Wavelet technique is adopted in the present study. It allows
one to identify the frequency content present in the signal at different
instant of time. The STD-MRA analysis helps one to identify the
frequency band in which the energy content of the UHF signal is
maximum.
Abstract: Tandem mass spectrometry (MS/MS) is the engine
driving high-throughput protein identification. Protein mixtures possibly
representing thousands of proteins from multiple species are
treated with proteolytic enzymes, cutting the proteins into smaller
peptides that are then analyzed generating MS/MS spectra. The
task of determining the identity of the peptide from its spectrum
is currently the weak point in the process. Current approaches to de
novo sequencing are able to compute candidate peptides efficiently.
The problem lies in the limitations of current scoring functions. In this
paper we introduce the concept of proteome signature. By examining
proteins and compiling proteome signatures (amino acid usage) it is
possible to characterize likely combinations of amino acids and better
distinguish between candidate peptides. Our results strongly support
the hypothesis that a scoring function that considers amino acid usage
patterns is better able to distinguish between candidate peptides. This
in turn leads to higher accuracy in peptide prediction.
Abstract: In manufacturing industries, development of measurement leads to increase the number of monitoring variables and eventually the importance of multivariate control comes to the fore. Statistical process control (SPC) is one of the most widely used as multivariate control chart. Nevertheless, SPC is restricted to apply in processes because its assumption of data as following specific distribution. Unfortunately, process data are composed by the mixture of several processes and it is hard to estimate as one certain distribution. To alternative conventional SPC, therefore, nonparametric control chart come into the picture because of the strength of nonparametric control chart, the absence of parameter estimation. SVDD based control chart is one of the nonparametric control charts having the advantage of flexible control boundary. However,basic concept of SVDD has been an oversight to the important of data characteristic, density distribution. Therefore, we proposed DW-SVDD (Density Weighted SVDD) to cover up the weakness of conventional SVDD. DW-SVDD makes a new attempt to consider dense of data as introducing the notion of density Weight. We extend as control chart using new proposed SVDD and a simulation study of various distributional data is conducted to demonstrate the improvement of performance.
Abstract: Decision Support System (DSS) are interactive
software systems that are built to assist the management of an
organization in the decision making process when faced with nonroutine
problems in a specific application domain. Non-functional
requirements (NFRs) for a DSS deal with the desirable qualities and
restrictions that the DSS functionalities must satisfy. Unlike the
functional requirements, which are tangible functionalities provided
by the DSS, NFRs are often hidden and transparent to DSS users but
affect the quality of the provided functionalities. NFRs are often
overlooked or added later to the system in an ad hoc manner, leading
to a poor overall quality of the system. In this paper, we discuss the
development of NFRs as part of the requirements engineering phase
of the system development life cycle of DSSs. To help eliciting
NFRs, we provide a comprehensive taxonomy of NFRs for DSSs.
Abstract: The Ni/α-Al2O3 catalysts with different amounts of La
as promoter from 0 to 4 wt % were prepared, characterized and their
catalytic activity was investigated in syngas methanation reaction.
Effects of reaction temperature and lanthanum loading on carbon
oxides conversion and methane selectivity were also studied. Adding
certain amount of lanthanum to 10Ni /α-Al2O3 catalysts can decrease
the average NiO crystallite diameter which leads to higher activity and
stability while excessive addition would cause deactivation quickly.
Stability on stream towards deactivation was observed up to 800 min
at 500 °C, 0.1MPa and 600000 mL·g-1·h-1.
Abstract: The objective of this study is to evaluate the threshold
stress of the clay with sand subgrade soil. Threshold stress can be
defined as the stress level above which cyclic loading leads to
excessive deformation and eventual failure. The thickness
determination of highways formations using the threshold stress
approach is a more realistic assessment of the soil behaviour because
it is subjected to repeated loadings from moving vehicles. Threshold
stress can be evaluated by plastic strain criterion, which is based on
the accumulated plastic strain behaviour during cyclic loadings [1].
Several conditions of the all-round pressure the subgrade soil namely,
zero confinement, low all-round pressure and high all-round pressure
are investigated. The threshold stresses of various soil conditions are
determined. Threshold stress of the soil are 60%, 31% and 38.6% for
unconfined partially saturated sample, low effective stress saturated
sample, high effective stress saturated sample respectively.
Abstract: In this paper the effect of faults in the elements and
parts of discrete event systems is investigated. In the occurrence of
faults, some states of the system must be changed and some of them
must be forbidden. For this goal, different states of these elements are
examined and a model for fail-safe behavior of each state is
introduced. Replacing new models of the target elements in the
preliminary model by a systematic method, leads to a fail-safe
discrete event system.
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: The survey and classification of the different security
attacks in structured peer-to-peer (P2P) overlay networks can be
useful to computer system designers, programmers, administrators,
and users. In this paper, we attempt to provide a taxonomy of
structured P2P overlay networks security attacks. We have specially
focused on the way these attacks can arise at each level of the
network. Moreover, we observed that most of the existing systems
such as Content Addressable Network (CAN), Chord, Pastry,
Tapestry, Kademlia, and Viceroy suffer from threats and vulnerability
which lead to disrupt and corrupt their functioning. We hope that our
survey constitutes a good help for who-s working on this area of
research.
Abstract: The Canadian aerospace industry faces many
challenges. One of them is the difficulty in estimating costs. In
particular, the design effort required in a project impacts resource
requirements and lead-time, and consequently the final cost. This
paper presents the findings of a case study conducted for recognized
global leader in the design and manufacturing of aircraft engines. The
study models parametric cost estimation relationships to estimate the
design effort of integrated blade-rotor low-pressure compressor fans.
Several effort drivers are selected to model the relationship.
Comparative analyses of three types of models are conducted. The
model with the best accuracy and significance in design estimation is
retained.