Abstract: Through a proper analysis of residual strain and stress
distributions obtained at the surface of high speed milled specimens
of AA 6082–T6 aluminium alloy, the performance of an improved
indentation method is evaluated. This method integrates a special
device of indentation to a universal measuring machine. The
mentioned device allows introducing elongated indents allowing to
diminish the absolute error of measurement. It must be noted that the
present method offers the great advantage of avoiding both the
specific equipment and highly qualified personnel, and their inherent
high costs. In this work, the cutting tool geometry and high speed
parameters are selected to introduce reduced plastic damage.
Through the variation of the depth of cut, the stability of the shapes
adopted by the residual strain and stress distributions is evaluated.
The results show that the strain and stress distributions remain
unchanged, compressive and small. Moreover, these distributions
reveal a similar asymmetry when the gradients corresponding to
conventional and climb cutting zones are compared.
Abstract: The Maximum Weighted Independent Set (MWIS)
problem is a classic graph optimization NP-hard problem. Given an
undirected graph G = (V, E) and weighting function defined on the
vertex set, the MWIS problem is to find a vertex set S V whose total
weight is maximum subject to no two vertices in S are adjacent. This
paper presents a novel approach to approximate the MWIS of a graph
using minimum weighted vertex cover of the graph. Computational
experiments are designed and conducted to study the performance
of our proposed algorithm. Extensive simulation results show that
the proposed algorithm can yield better solutions than other existing
algorithms found in the literature for solving the MWIS.
Abstract: In this paper, we study the application of Extreme
Learning Machine (ELM) algorithm for single layered feedforward
neural networks to non-linear chaotic time series problems. In this
algorithm the input weights and the hidden layer bias are randomly
chosen. The ELM formulation leads to solving a system of linear
equations in terms of the unknown weights connecting the hidden
layer to the output layer. The solution of this general system of
linear equations will be obtained using Moore-Penrose generalized
pseudo inverse. For the study of the application of the method we
consider the time series generated by the Mackey Glass delay
differential equation with different time delays, Santa Fe A and
UCR heart beat rate ECG time series. For the choice of sigmoid,
sin and hardlim activation functions the optimal values for the
memory order and the number of hidden neurons which give the
best prediction performance in terms of root mean square error are
determined. It is observed that the results obtained are in close
agreement with the exact solution of the problems considered
which clearly shows that ELM is a very promising alternative
method for time series prediction.
Abstract: A major part of the flow field involves no complicated
turbulent behavior in many turbulent flows. In this research work, in
order to reduce required memory and CPU time, the flow field was
decomposed into several blocks, each block including its special
turbulence. A two dimensional backward facing step was considered
here. Four combinations of the Prandtl mixing length and standard k-
E models were implemented as well. Computer memory and CPU
time consumption in addition to numerical convergence and accuracy
of the obtained results were mainly investigated. Observations
showed that, a suitable combination of turbulence models in different
blocks led to the results with the same accuracy as the high order
turbulence model for all of the blocks, in addition to the reductions in
memory and CPU time consumption.
Abstract: This paper presents an Extended Kaman Filter
implementation of a single-camera Visual Simultaneous Localization
and Mapping algorithm, a novel algorithm for simultaneous
localization and mapping problem widely studied in mobile robotics
field. The algorithm is vision and odometry-based, The odometry
data is incremental, and therefore it will accumulate error over time,
since the robot may slip or may be lifted, consequently if the
odometry is used alone we can not accurately estimate the robot
position, in this paper we show that a combination of odometry and
visual landmark via the extended Kalman filter can improve the robot
position estimate. We use a Pioneer II robot and motorized pan tilt
camera models to implement the algorithm.
Abstract: Bioinformatics and Cheminformatics use computer as disciplines providing tools for acquisition, storage, processing, analysis, integrate data and for the development of potential applications of biological and chemical data. A chemical database is one of the databases that exclusively designed to store chemical information. NMRShiftDB is one of the main databases that used to represent the chemical structures in 2D or 3D structures. SMILES format is one of many ways to write a chemical structure in a linear format. In this study we extracted Antimicrobial Structures in SMILES format from NMRShiftDB and stored it in our Local Data Warehouse with its corresponding information. Additionally, we developed a searching tool that would response to user-s query using the JME Editor tool that allows user to draw or edit molecules and converts the drawn structure into SMILES format. We applied Quick Search algorithm to search for Antimicrobial Structures in our Local Data Ware House.
Abstract: The present study attempted to improve the Mercury
(Hg) sorption capacity of kanuma volcanic ash soil (KVAS) by
impregnating the cupper (Cu). Impregnation was executed by 1 and
5% Cu powder and sorption characterization of optimum Hg
removing Cu impregnated KVAS was performed under different
operational conditions, contact time, solution pH, sorbent dosage and
Hg concentration using the batch operation studies. The 1% Cu
impregnated KVAS pronounced optimum improvement (79%) in
removing Hg from water compare to control. The present
investigation determined the equilibrium state of maximum Hg
adsorption at 6 h contact period. The adsorption revealed a pH
dependent response and pH 3.5 showed maximum sorption capacity
of Hg. Freundlich isotherm model is well fitted with the experimental
data than that of Langmuir isotherm. It can be concluded that the Cu
impregnation improves the Hg sorption capacity of KVAS and 1%
Cu impregnated KVAS could be employed as cost-effective
adsorbent media for treating Hg contaminated water.
Abstract: This research aimed to study on the potential of
recycling organic waste in Suan Sunandha Rajabhat University as
compost. In doing so, the composition of solid waste generated in the
campus was investigated while physical and chemical properties of
organic waste were analyzed in order to evaluate the portion of waste
suitable for recycling as compost. As a result of the study, it was
found that (1) the amount of organic waste was averaged at 299.8
kg/day in which mixed food wastes had the highest amount of 191.9
kg/day followed by mixed leave & yard wastes and mixed fruit &
vegetable wastes at the amount of 66.3 and 41.6 kg/day respectively;
(2) physical and chemical properties of organic waste in terms of
moisture content was between 69.54 to 78.15%, major elements for
plant as N, P and K were 0.14 to 0.17%, 0.46 to 0.52% and 0.16 to
0.18% respectively, and carbon/nitrogen ratio (C/N) was about 15:1
to 17.5:1; (3) recycling organic waste as compost was designed by
aerobic decomposition using mixed food wastes : mixed leave & yard
wastes : mixed fruit & vegetable wastes at the portion of 3:2:1 by
weight in accordance with the potential of their amounts and their
physical and chemical properties.
Abstract: Yogurt is a coagulated milk product obtained from
the lactic acid fermentation by the action of Lactobacillus
bulgaricus and Streptococcus thermophilus. The additions of fruits
into milk may enhance the taste and the therapeutical values of milk
products. However fruits also may change the fermentation
behaviour. In this present study, the changes in physicochemical, the
peptide concentration, total phenolics content and the antioxidant
potential of yogurt upon the addition of Hylocereus polyrhizus and
Hylocereus undatus (white and red dragon fruit) were investigated.
Fruits enriched yogurt (10%, 20%, 30% w/w) were prepared and the
pH, TTA, syneresis measurement, peptide concentration, total
phenolics content and DPPH antioxidant inhibition percentage were
determined. Milk fermentation rate was enhanced in red dragon fruit
yogurt for all doses (-0.3606 - -0.4126 pH/h) while only white
dragon fruit yogurt with 20% and 30% (w/w) composition showed
increment in fermentation rate (-0.3471 - -0.3609 pH/h) compared to
plain yogurt (-0.3369pH/h). All dragon fruit enriched yogurts
generally showed lower pH readings (pH 3.95 - 4.03) compared to
plain yogurt (pH 4.05). Both fruit yogurts showed a higher lactic
acid percentage (1.14-1.23%) compared to plain yogurt (1.08%).
Significantly higher syneresis percentage (57.19 - 70.32%)
compared to plain yogurt (52.93%) were seen in all fruit enriched
yogurts. The antioxidant activity of plain yogurt (19.16%) was
enhanced by the presence of white and red dragon fruit (24.97-
45.74%). All fruit enriched yogurt showed an increment in total
phenolic content (36.44 - 64.43mg/ml) compared to plain yogurt
(20.25mg/ml). However, the addition of white and red dragon fruit
did not enhance the proteolysis of milk during fermentation.
Therefore, it could be concluded that the addition of white and red
dragon fruit into yogurt enhanced the milk fermentation rate, lactic
acid content, syneresis percentage, antioxidant activity, and total
phenolics content in yogurt.
Abstract: This study was designed to investigate the role of serum nitric oxide and sialic acid in the development of diabetic nephropathy as disease marker. Total 210 diabetic patients (age and sex matched) were selected followed by informed consent and divided into four groups (70 each) as I: control; II: diabetic; III: diabetic hypertensive; IV: diabetic nephropathy. The blood samples of all subjects were collected and analyzed for serum nitric oxide, sialic acid, fasting blood glucose, serum urea, creatinine, HbA1c and GFR. The BMI, systolic and diastolic blood pressures, blood glucose, HbA1c and serum sialic acid levels were high (p
Abstract: Organochlorine pesticides (OCPs) are known to be
persistent and bioaccumulative toxicants that may cause reproductive
impairments in wildlife as well as human. The current study uses the
snail-eating turtle Malayemys macrocephala, a long-lived animal
commonly distribute in rice field habitat in central part of Thailand,
as a sentinel to monitor OCP contamination in environment. The
nest soil, complete clutch of eggs, and blood of the turtle were
collected from agricultural areas in the Chao Phraya River Basin,
Thailand during the nesting season of 2007-2008. The novel
methods for tissue extraction by an accelerated solvent extractor
(ASE, for egg) and liquid-liquid extraction (for blood) have been
developed. The nineteen OCP residues were analyzed by gas
chromatography with micro-electron captured detector (GC-μECD).
The validated methods have met requirements of the AOAC
standard. The results indicated that significant amounts of OCPs are
still contaminated in nest soil and eggs of the turtle even though the
OCPs had been banned in this area for many years. This suggested
the potential risk to health of wildlife as well as human in the area.
Abstract: This paper presents a controller design technique for
Synchronous Reluctance Motor to improve its dynamic performance
with fast response and high accuracy. The sliding mode control is the
most attractive and suitable method to use for this purpose, since it is
simple in design and for its insensitivity to parameter variations or
external disturbances. When this method implemented it yields fast
dynamic response without overshoot and a zero steady-state error.
The current loop control with decentralized sliding mode is presented
in this paper. The mathematical model for the synchronous machine,
the inverter and the controller is developed. The stability of the
sliding mode controller is analyzed. Simulation of synchronous
reluctance motor and the controller with PWM-inverter has been
curried out, using the SIMULINK software package of MATLAB.
Simulation results are presented to show the effectiveness of the
approach.
Abstract: In this paper we discuss a set of guidelines which
could be adapted when designing an audio user interface for the
visually impaired. It is based on an audio environment that is
focused on audio positioning. Unlike current applications which only
interpret Graphical User Interface (GUI) for the visually impaired,
this particular audio environment bypasses GUI to provide a direct
auditory output. It presents the capability of two dimensional (2D)
navigation on audio interfaces. This paper highlights the significance
of a 2D audio environment with spatial information in the context
of the visually impaired. A thorough usability study has been conducted
to prove the applicability of proposed design guidelines for
these auditory interfaces. While proving these guidelines, previously
unearthed design aspects have been revealed in this study.
Abstract: This paper deals with the problem of thermal and
mechanical shocks, which rising during operation, mostly at
interrupted cut. Here will be solved their impact on the cutting edge
tool life, the impact of coating technology on resistance to shocks
and experimental determination of tool life in heating flame.
Resistance of removable cutting edges against thermal and
mechanical shock is an important indicator of quality as well as its
abrasion resistance. Breach of the edge or its crumble may occur due
to cyclic loading. We can observe it not only during the interrupted
cutting (milling, turning areas abandoned hole or slot), but also in
continuous cutting. This is due to the volatility of cutting force on
cutting. Frequency of the volatility in this case depends on the type
of rising chips (chip size element). For difficult-to-machine materials
such as austenitic steel particularly happened at higher cutting speeds
for the localization of plastic deformation in the shear plane and for
the inception of separate elements substantially continuous chips.
This leads to variations of cutting forces substantially greater than for
other types of steel.
Abstract: This paper presents a new approach for the prob-ability density function estimation using the Support Vector Ma-chines (SVM) and the Expectation Maximization (EM) algorithms.In the proposed approach, an advanced algorithm for the SVM den-sity estimation which incorporates the Mean Field theory in the learning process is used. Instead of using ad-hoc values for the para-meters of the kernel function which is used by the SVM algorithm,the proposed approach uses the EM algorithm for an automatic optimization of the kernel. Experimental evaluation using simulated data set shows encouraging results.
Abstract: In this article we present a methodology which
enables preschool and primary school unlanguaged children to
remember words, phrases and texts with the help of graphic signs -
letters, syllables and words. Reading for a child becomes a support
for speech development. Teaching is based on the principle "from
simple to complex", "a letter - a syllable - a word - a proposal - a
text." Availability of multi-level texts allows using this methodology
for working with children who have different levels of speech
development.
Abstract: A pilot project was carried out in 2007 by the senior
students of Cyprus International University, aiming to minimize the
total cost of waste collection in Northern Cyprus. Many developed
and developing countries have cut their transportation costs – which
lies between 30-40% – down at a rate of 40% percent, by
implementing network models for their route assignments.
Accordingly, a network model was implemented at Göçmenköy
district, to optimize and standardize waste collection works. The
work environment of the employees were also redesigned to provide
maximum ergonomy and to increase productivity, efficiency and
safety. Following the collection of the required data including waste
densities, lengths of roads and population, a model was constructed
to allocate the optimal route assignment for the waste collection
trucks at Göçmenköy district.
Abstract: Energy consumption is one of the indices in
determining the levels of development of a nation. Therefore,
availability of energy supply to all sectors of life in any country is
crucial for its development. These exists shortage of all kinds of
energy, particularly electricity which is badly needed for economic
development. Electricity from the sun which is quite abundant in
most of the developing countries is used in rural areas to meet basic
electricity needs of a rural community. Today-s electricity supply in
Myanmar is generated by fuel generators and hydroelectric power
plants. However, far-flung areas which are away from National Grids
cannot enjoy the electricity generated by these sources. Since
Myanmar is a land of plentiful sunshine, especially in central and
southern regions of the country, the first form of energy- solar energy
could hopefully become the final solution to its energy supply
problem. The direct conversion of solar energy into electricity using
photovoltaic system has been receiving intensive installation not only
in developed countries but also in developing countries. It is mainly
intended to present solar energy potential and application in
Myanmar. It is also wanted to get the benefits of using solar energy
for people in remote areas which are not yet connected to the national
grids because of the high price of fossil fuel.
Abstract: Caching was suggested as a solution for reducing bandwidth utilization and minimizing query latency in mobile environments. Over the years, different caching approaches have been proposed, some relying on the server to broadcast reports periodically informing of the updated data while others allowed the clients to request for the data whenever needed. Until recently a hybrid cache consistency scheme Scalable Asynchronous Cache Consistency Scheme SACCS was proposed, which combined the two different approaches benefits- and is proved to be more efficient and scalable. Nevertheless, caching has its limitations too, due to the limited cache size and the limited bandwidth, which makes the implementation of cache replacement strategy an important aspect for improving the cache consistency algorithms. In this thesis, we proposed a new cache replacement strategy, the Least Unified Value strategy (LUV) to replace the Least Recently Used (LRU) that SACCS was based on. This paper studies the advantages and the drawbacks of the new proposed strategy, comparing it with different categories of cache replacement strategies.
Abstract: In this paper a novel high output impedance, low input impedance, wide bandwidth, very simple current mirror with input and output voltage requirements less than that of a simple current mirror is presented. These features are achieved with very simple structure avoiding extra large node impedances to ensure high bandwidth operation. The circuit's principle of operation is discussed and compared to simple and low voltage cascode (LVC) current mirrors. Such outstanding features of this current mirror as high output impedance ~384K, low input impedance~6.4, wide bandwidth~178MHz, low input voltage ~ 362mV, low output voltage ~ 38mV and low current transfer error ~4% (all at 50μA) makes it an outstanding choice for high performance applications. Simulation results in BSIM 0.35μm CMOS technology with HSPICE are given in comparison with simple, and LVC current mirrors to verify and validate the performance of the proposed current mirror.