Abstract: An efficient architecture for low jitter All Digital
Phase Locked Loop (ADPLL) suitable for high speed SoC
applications is presented in this paper. The ADPLL is designed using
standard cells and described by Hardware Description Language
(HDL). The ADPLL implemented in a 90 nm CMOS process can
operate from 10 to 200 MHz and achieve worst case frequency
acquisition in 14 reference clock cycles. The simulation result shows
that PLL has cycle to cycle jitter of 164 ps and period jitter of 100 ps
at 100MHz. Since the digitally controlled oscillator (DCO) can
achieve both high resolution and wide frequency range, it can meet
the demands of system-level integration. The proposed ADPLL can
easily be ported to different processes in a short time. Thus, it can
reduce the design time and design complexity of the ADPLL, making
it very suitable for System-on-Chip (SoC) applications.
Abstract: The past decade has witnessed a good opportunities
for city development schemes in UK. The government encouraged
restoration of city centers to comprise mixed use developments with
high density residential apartments. Investments in regeneration areas
were doing well according to the analyses of Property Databank
(IPD). However, more recent analysis by IPD has shown that since
2007, property in regeneration areas has been more vulnerable to the
market downturn than other types of investment property. The early
stages of a property market downturn may be felt most in
regeneration where funding, investor confidence and occupier
demand would dissipate because the sector was considered more
marginal or risky when development costs rise. Moreover, the Bank
of England survey shows that lenders have sequentially tightened the
availability of credit for commercial real estate since mid-2007. A
sharp reduction in the willingness of banks to lend on commercial
property was recorded. The credit crunch has already affected
commercial property but its impact has been particularly severe in
certain kinds of properties where residential developments are
extremely difficult, in particular city centre apartments and buy-to-let
markets. Commercial property – retail, industrial leisure and mixed
use were also pressed, in Birmingham; tens of mixed use plots were
built to replace old factories in the heart of the city. The purpose of
these developments was to enable young professionals to work and
live in same place. Thousands of people lost their jobs during the
recession, moreover lending was more difficult and the future of
many developments is unknown. The recession casts its shadow upon
the society due to cuts in public spending by government, Inflation,
rising tuition fees and high rise in unemployment generated anger and
hatred was spreading among youth causing vandalism and riots in
many cities. Recent riots targeted many mixed used development in
the UK where banks, shops, restaurants and big stores were robbed
and set into fire leaving residents with horror and shock. This paper
examines the impact of the recession and riots on mixed use
development in UK.
Abstract: Bones are dynamic and responsive organs, they
regulate their strength and mass according to the loads which they are subjected. Because, the Wnt/β-catenin pathway has profound
effects on the regulation of bone mass, we hypothesized that mechanical loading of bone cells stimulates Wnt/β-catenin signaling, which results in the generation of new bone mass.
Mechanical loading triggers the secretion of the Wnt molecule, which after binding to transmembrane proteins, causes GSK-3β (Glycogen synthase kinase 3 beta) to cease the phosphorylation of β-catenin. β-catenin accumulation in the cytoplasm, followed by its
transport into the nucleus, binding to transcription factors (TCF/LEF)
that initiate transcription of genes related to bone formation. To test this hypothesis, we used TOPGAL (Tcf Optimal Promoter
β-galactosidase) mice in an experiment in which cyclic loads were
applied to the forearm. TOPGAL mice are reporters for cells effected
by the Wnt/β-catenin signaling pathway. TOPGAL mice are genetically engineered mice in which transcriptional activation of β-
catenin, results in the production of an enzyme, β-galactosidase. The
presence of this enzyme allows us to localize transcriptional
activation of β-catenin to individual cells, thereby, allowing us to quantify the effects that mechanical loading has on the Wnt/β-catenin pathway and new bone formation. The ulnae of loaded TOPGAL
mice were excised and transverse slices along different parts of the
ulnar shaft were assayed for the presence of β-galactosidase.
Our results indicate that loading increases β-catenin transcriptional
activity in regions where this pathway is already primed (i.e. where basal activity is already higher) in a load magnitude dependent
manner. Further experiments are needed to determine the temporal and spatial activation of this signaling in relation to bone formation.
Abstract: Crime is a major societal problem for most of the
world's nations. Consequently, the police need to develop new
methods to improve their efficiency in dealing with these ever increasing crime rates. Two of the common difficulties that the police
face in crime control are crime investigation and the provision of crime information to the general public to help them protect themselves. Crime control in police operations involves the use of
spatial data, crime data and the related crime data from different organizations (depending on the nature of the analysis to be made).
These types of data are collected from several heterogeneous sources
in different formats and from different platforms, resulting in a lack of standardization. Moreover, there is no standard framework for
crime data collection, integration and dissemination through mobile
devices. An investigation into the current situation in crime control was carried out to identify the needs to resolve these issues. This
paper proposes and investigates the use of service oriented
architecture (SOA) and the mobile spatial information service in crime control. SOA plays an important role in crime control as an
appropriate way to support data exchange and model sharing from
heterogeneous sources. Crime control also needs to facilitate mobile
spatial information services in order to exchange, receive, share and release information based on location to mobile users anytime and
anywhere.
Abstract: Recurrent event data is a special type of multivariate
survival data. Dynamic and frailty models are one of the approaches
that dealt with this kind of data. A comparison between these two
models is studied using the empirical standard deviation of the
standardized martingale residual processes as a way of assessing the
fit of the two models based on the Aalen additive regression model.
Here we found both approaches took heterogeneity into account and
produce residual standard deviations close to each other both in the
simulation study and in the real data set.
Abstract: In this paper, a new technique of signal detection has been proposed for detecting the orthogonal frequency-division multiplexing (OFDM) signal in the presence of nonlinear distortion.There are several advantages of OFDM communications system.However, one of the existing problems is remain considered as the nonlinear distortion generated by high-power-amplifier at the transmitter end due to the large dynamic range of an OFDM signal. The proposed method is the maximum likelihood detection with the symbol estimation. When the training data are available, the neural network has been used to learn the characteristic of received signal and to estimate the new positions of the transmitted symbol which are provided to the maximum likelihood detector. Resulting in the system performance, the nonlinear distortions of a traveling wave tube amplifier with OFDM signal are considered in this paper.Simulation results of the bit-error-rate performance are obtained with 16-QAM OFDM systems.
Abstract: Exclusive breastfeeding is the feeding of a baby on no other milk apart from breast milk. Exclusive breastfeeding during the first 6 months of life is of fundamental importance because it supports optimal growth and development during infancy and reduces the risk of obliterating diseases and problems. Moreover, in developed countries, exclusive breastfeeding has decreased the incidence and/or severity of diarrhea, lower respiratory infection and urinary tract infection. In this paper, we study the factors that influence exclusive breastfeeding and use the Generalized Poisson regression model to analyze the practices of exclusive breastfeeding in Mauritius. We develop two sets of quasi-likelihood equations (QLE)to estimate the parameters.
Abstract: To compare Healing Effects of an
Ayurvedic Preparation and Silver Sulfadiazine on burn wounds in
Albino Rats.
Methods: Albino rats– 30 male / female rats weighing between
150-200 g were used in the study. They were individually housed and
maintained on normal diet and water ad libitum. Partial thickness
burn wounds were inflicted, on overnight-starved animals under
pentobarbitone (30mg/kg, i.p.) anaesthesia, by pouring hot molten
wax at 80oC into a plastic cylinder of 300 mm2 circular openings
placed on the shaven back of the animal. Apart from the drugs under
investigation no local/ systemic chemotherapeutic cover will be
provided to animals. All the animals were assessed for the percentage
of wound contraction, signs of infection, scab formation and
histopathological examination.
Results: Percentage of wound healing was significantly better in
the test ointment group compared to the standard. Signs of infection
were observed in more animals in the test ointment group compared
to the standard. Scab formation also took place earlier in the test
ointment group compared to standard. Epithelial regeneration and
healing profile was better in the test ointment compared to the
standard. Moreover the test ointment group did not show any raised
margins in the wound or blackish discoloration as was observed in
silver sulfadiazine group.
Conclusion: The burn wound healing effect of the ayurvedic
ointment under study is better in comparison to standard therapy of
silver sulfadiazine. The problem of infection encountered with the
test ointment can be overcome by changing the concentrations and
proportions of the ingredients in the test ointment which constitutes
the further plan of the study.
Abstract: The paper contains an investigation of winding numbers
of paths of zeros of analytic theta functions. We have considered
briefly an analytic representation of finite quantum systems ZN.
The analytic functions on a torus have exactly N zeros. The brief
introduction to the zeros of analytic functions and there time evolution
is given. We have discussed the periodic finite quantum systems. We
have introduced the winding numbers in general. We consider the
winding numbers of the zeros of analytic theta functions.
Abstract: The crop rice is the staple food of most Sierra Leone
with no close substitute. However, its cultivation has been on its last
legs over the years. The decline in the domestic rice cultivation has
had vicious socio-economic implications such as hiking consumer
prices, balance of payment dilemmas with debt burden. The objective
of this study is thus, to assess the effect of the shift of rural labour
towards non-agricultural sectors on rice cultivation. The tools utilized
for analyzing the problem under consideration involved a thorough
descriptive statistics and generalized linear model using OLS
technique. Increased rural population was established positive and
significant in affecting rice cultivation. Fertilizer utilization was
insignificant in rice cultivation. For reducing the shift of rural labor
force towards nonagricultural sectors, the government should make
the agricultural sector very lucrative.
Abstract: When the foundations of structures under cyclic
loading with amplitudes less than their permissible load, the concern exists often for the amount of uniform and non-uniform settlement of
such structures. Storage tank foundations with numerous filling and discharging and railways ballast course under repeating
transportation loads are examples of such conditions. This paper
deals with the effects of using the new generation of reinforcements,
Grid-Anchor, for the purpose of reducing the permanent settlement
of these foundations under the influence of different proportions of
the ultimate load. Other items such as the type and the number of
reinforcements as well as the number of loading cycles are studied numerically. Numerical models were made using the Plaxis3D
Tunnel finite element code. The results show that by using gridanchor
and increasing the number of their layers in the same
proportion as that of the cyclic load being applied, the amount of
permanent settlement decreases up to 42% relative to unreinforced
condition depends on the number of reinforcement layers and percent
of applied load and the number of loading cycles to reach a constant
value of dimensionless settlement decreases up to 20% relative to
unreinforced condition.
Abstract: In recent years, a number of works proposing the
combination of multiple classifiers to produce a single
classification have been reported in remote sensing literature. The
resulting classifier, referred to as an ensemble classifier, is
generally found to be more accurate than any of the individual
classifiers making up the ensemble. As accuracy is the primary
concern, much of the research in the field of land cover
classification is focused on improving classification accuracy. This
study compares the performance of four ensemble approaches
(boosting, bagging, DECORATE and random subspace) with a
univariate decision tree as base classifier. Two training datasets,
one without ant noise and other with 20 percent noise was used to
judge the performance of different ensemble approaches. Results
with noise free data set suggest an improvement of about 4% in
classification accuracy with all ensemble approaches in
comparison to the results provided by univariate decision tree
classifier. Highest classification accuracy of 87.43% was achieved
by boosted decision tree. A comparison of results with noisy data
set suggests that bagging, DECORATE and random subspace
approaches works well with this data whereas the performance of
boosted decision tree degrades and a classification accuracy of
79.7% is achieved which is even lower than that is achieved (i.e.
80.02%) by using unboosted decision tree classifier.
Abstract: This article presents the simulation, parameterization and optimization of an electromagnet with the C–shaped configuration, intended for the study of magnetic properties of materials. The electromagnet studied consists of a C-shaped yoke, which provides self–shielding for minimizing losses of magnetic flux density, two poles of high magnetic permeability and power coils wound on the poles. The main physical variable studied was the static magnetic flux density in a column within the gap between the poles, with 4cm2 of square cross section and a length of 5cm, seeking a suitable set of parameters that allow us to achieve a uniform magnetic flux density of 1x104 Gaussor values above this in the column, when the system operates at room temperature and with a current consumption not exceeding 5A. By means of a magnetostatic analysis by the finite element method, the magnetic flux density and the distribution of the magnetic field lines were visualized and quantified. From the results obtained by simulating an initial configuration of electromagnet, a structural optimization of the geometry of the adjustable caps for the ends of the poles was performed. The magnetic permeability effect of the soft magnetic materials used in the poles system, such as low– carbon steel (0.08% C), Permalloy (45% Ni, 54.7% Fe) and Mumetal (21.2% Fe, 78.5% Ni), was also evaluated. The intensity and uniformity of the magnetic field in the gap showed a high dependence with the factors described above. The magnetic field achieved in the column was uniform and its magnitude ranged between 1.5x104 Gauss and 1.9x104 Gauss according to the material of the pole used, with the possibility of increasing the magnetic field by choosing a suitable geometry of the cap, introducing a cooling system for the coils and adjusting the spacing between the poles. This makes the device a versatile and scalable tool to generate the magnetic field necessary to perform magnetic characterization of materials by techniques such as vibrating sample magnetometry (VSM), Hall-effect, Kerr-effect magnetometry, among others. Additionally, a CAD design of the modules of the electromagnet is presented in order to facilitate the construction and scaling of the physical device.
Abstract: This study compares three meta heuristics to minimize makespan (Cmax) for Hybrid Flow Shop (HFS) Scheduling Problem with Parallel Machines. This problem is known to be NP-Hard. This study proposes three algorithms among improvement heuristic searches which are: Genetic Algorithm (GA), Simulated Annealing (SA), and Tabu Search (TS). SA and TS are known as deterministic improvement heuristic search. GA is known as stochastic improvement heuristic search. A comprehensive comparison from these three improvement heuristic searches is presented. The results for the experiments conducted show that TS is effective and efficient to solve HFS scheduling problems.
Abstract: This paper presents modeling and optimization of two NP-hard problems in flexible manufacturing system (FMS), part type selection problem and loading problem. Due to the complexity and extent of the problems, the paper was split into two parts. The first part of the papers has discussed the modeling of the problems and showed how the real coded genetic algorithms (RCGA) can be applied to solve the problems. This second part discusses the effectiveness of the RCGA which uses an array of real numbers as chromosome representation. The novel proposed chromosome representation produces only feasible solutions which minimize a computational time needed by GA to push its population toward feasible search space or repair infeasible chromosomes. The proposed RCGA improves the FMS performance by considering two objectives, maximizing system throughput and maintaining the balance of the system (minimizing system unbalance). The resulted objective values are compared to the optimum values produced by branch-and-bound method. The experiments show that the proposed RCGA could reach near optimum solutions in a reasonable amount of time.
Abstract: Models are placed by modeling paradigm at the center of development process. These models are represented by languages, like UML the language standardized by the OMG which became necessary for development. Moreover the ontology engineering paradigm places ontologies at the center of development process; in this paradigm we find OWL the principal language for knowledge representation. Building ontologies from scratch is generally a difficult task. The bridging between UML and OWL appeared on several regards such as the classes and associations. In this paper, we have to profit from convergence between UML and OWL to propose an approach based on Meta-Modelling and Graph Grammars and registered in the MDA architecture for the automatic generation of OWL ontologies from UML class diagrams. The transformation is based on transformation rules; the level of abstraction in these rules is close to the application in order to have usable ontologies. We illustrate this approach by an example.
Abstract: Smart Dust particles, are small smart materials used for generating weather maps. We investigate question of the optimal number of Smart Dust particles necessary for generating precise, computationally feasible and cost effective 3–D weather maps. We also give an optimal matching algorithm for the generalized scenario, when there are N Smart Dust particles and M ground receivers.
Abstract: In view of their importance and usefulness in reliability theory and probability distributions, several generalizations of the inverse Gaussian distribution and the Krtzel function are investigated in recent years. This has motivated the authors to introduce and study a new generalization of the inverse Gaussian distribution and the Krtzel function associated with a product of a Bessel function of the third kind )(zKQ and a Z - Fox-Wright generalized hyper geometric function introduced in this paper. The introduced function turns out to be a unified gamma-type function. Its incomplete forms are also discussed. Several properties of this gamma-type function are obtained. By means of this generalized function, we introduce a generalization of inverse Gaussian distribution, which is useful in reliability analysis, diffusion processes, and radio techniques etc. The inverse Gaussian distribution thus introduced also provides a generalization of the Krtzel function. Some basic statistical functions associated with this probability density function, such as moments, the Mellin transform, the moment generating function, the hazard rate function, and the mean residue life function are also obtained.KeywordsFox-Wright function, Inverse Gaussian distribution, Krtzel function & Bessel function of the third kind.
Abstract: In many buildings we rely on large footings to offer
structural stability. Designers often compensate for the lack of
knowledge available with regard to foundation-soil interaction by
furnishing structures with overly large footings. This may lead to a
significant increase in building expenditures if many large
foundations are present. This paper describes the interface material
law that governs the behavior along the contact surface of adjacent
materials, and the behavior of a large foundation under ultimate limit
loading. A case study is chosen that represents a common
foundation-soil system frequently used in general practice and
therefore relevant to other structures. Investigations include
compressing versus uplifting wind forces, alterations to the
foundation size and subgrade compositions, the role of the slab
stiffness and presence and the effect of commonly used structural
joints and connections. These investigations aim to provide the
reader with an objective design approach, efficiently preventing
structural instability.
Abstract: This paper present a MATLAB-SIMULINK model of a single phase 2.5 KVA, 240V RMS controlled PV VSI (Photovoltaic Voltage Source Inverter) inverter using IGBTs (Insulated Gate Bipolar Transistor). The behavior of output voltage, output current, and the total harmonic distortion (THD), with the variation in input dc blocking capacitor (Cdc), for linear and non-linear load has been analyzed. The values of Cdc as suggested by the other authors in their papers are not clearly defined and it poses difficulty in selecting the proper value. As the dc power stored in Cdc, (generally placed parallel with battery) is used as input to the VSI inverter. The simulation results shows the variation in the output voltage and current with different values of Cdc for linear and non-linear load connected at the output side of PV VSI inverter and suggest the selection of suitable value of Cdc.