Abstract: Measurements of capacitance C and dissipation
factor tand of the stator insulation system provide useful information
about internal defects within the insulation. The index k is defined as
the proportionality constant between the changes at high voltage of
capacitance DC and of the dissipation factor Dtand . DC and
Dtand values were highly correlated when small flat defects were
within the insulation and that correlation was lost in the presence of
large narrow defects like electrical treeing. The discrimination
between small and large defects is made resorting to partial discharge
PD phase angle analysis. For the validation of the results, C and tand
measurements were carried out in a 15MVA 4160V steam turbine
turbogenerator placed in a sugar mill. In addition, laboratory test
results obtained by other authors were analyzed jointly. In such
laboratory tests, model coil bars subjected to thermal cycling resulted
highly degraded and DC and Dtand values were not correlated. Thus,
the index k could not be calculated.
Abstract: Sound pathways in the enclosures of small earphones
are very narrow. In such narrow pathways, the speed of sound
propagation and the phase of sound waves change because of the air
viscosity. We have developed a new finite element method that
includes the effects of damping due to air viscosity for modeling the
sound pathway. This method is developed as an extension of the
existing finite element method for porous sound-absorbing materials.
The numerical calculation results using the proposed finite element
method are validated against the existing calculation methods.
Abstract: In this paper, the least-squares design of variable fractional-delay (VFD) finite impulse response (FIR) digital differentiators is proposed. The used transfer function is formulated so that Farrow structure can be applied to realize the designed system. Also, the symmetric characteristics of filter coefficients are derived, which leads to the complexity reduction by saving almost a half of the number of coefficients. Moreover, all the elements of related vectors or matrices for the optimal process can be represented in closed forms, which make the design easier. Design example is also presented to illustrate the effectiveness of the proposed method.
Abstract: Historic preservation areas are extremely vulnerable to disasters because they are home to many vulnerable people and contain many closely spaced wooden houses. However, the narrow streets in these regions have historic meaning, which means that they cannot be widened and can become blocked easily during large disasters. Here, we describe our efforts to establish a methodology for the planning of evacuation route sin such historic preservation areas. In particular, this study aims to clarify the effectiveness of measures intended to secure two-way evacuation routes for vulnerable people during large disasters in a historic area preserved under the Cultural Properties Protection Law, Japan.
Abstract: Vector quantization is a powerful tool for speech
coding applications. This paper deals with LPC Coding of speech
signals which uses a new technique called Multi Switched Split
Vector Quantization (MSSVQ), which is a hybrid of Multi, switched,
split vector quantization techniques. The spectral distortion
performance, computational complexity, and memory requirements
of MSSVQ are compared to split vector quantization (SVQ), multi
stage vector quantization(MSVQ) and switched split vector
quantization (SSVQ) techniques. It has been proved from results that
MSSVQ has better spectral distortion performance, lower
computational complexity and lower memory requirements when
compared to all the above mentioned product code vector
quantization techniques. Computational complexity is measured in
floating point operations (flops), and memory requirements is
measured in (floats).
Abstract: Antimosy-doped tin oxide (ATO) particles were
prepared via chemical coprecipitation and reverse emulsion. The size
and size distribution of ATO particles were obviously decreased via
reverse microemulsion method. At the relatively high yield the ATO
particles were nearly spherical in shape, meanwhile the crystalline
structure and excellent conductivity were reserved, which could satisfy
the requirement as composite fillers, such as dielectric filler of
polyimide film.
Abstract: Fractional delay FIR filters design method based on
the differential evolution algorithm is presented. Differential evolution
is an evolutionary algorithm for solving a global optimization problems in the continuous search space. In the proposed approach,
an evolutionary algorithm is used to determine the coefficients of
a fractional delay FIR filter based on the Farrow structure. Basic
differential evolution is enhanced with a restricted mating technique,
which improves the algorithm performance in terms of convergence
speed and obtained solution. Evolutionary optimization is carried out by minimizing an objective function which is based on the amplitude
response and phase delay errors. Experimental results show that the proposed algorithm leads to a reduction in the amplitude response and phase delay errors relative to those achieved with the Least-Squares
method.
Abstract: This article experimentally investigates the
thermal performance of thermoelectric air-cooling module
which comprises a thermoelectric cooler (TEC) and an
air-cooling heat sink. The influences of input current and heat
load are determined. And performances under each situation
are quantified by thermal resistance analysis. Since TEC
generates Joule heat, this nature makes construction of thermal
resistance network difficult. To simplify the analysis, this
article emphasizes on the resistance heat load might meet when
passing through the device. Therefore, the thermal resistances
in this paper are to divide temperature differences by heat load.
According to the result, there exists an optimum input current
under every heating power. In this case, the optimum input
current is around 6A or 7A. The performance of the heat sink
would be improved with TEC under certain heating power and
input current, especially at a low heat load. According to the
result, the device can even make the heat source cooler than the
ambient. However, TEC is not always effective at every heat
load and input current. In some situation, the device works
worse than the heat sink without TEC. To determine the
availability of TEC, this study figures out the effective
operating region in which the TEC air-cooling module works
better than the heat sink without TEC. The result shows that
TEC is more effective at a lower heat load. If heat load is too
high, heat sink with TEC will perform worse than without TEC.
The limit of this device is 57W. Besides, TEC is not helpful if
input current is too high or too low. There is an effective range
of input current, and the range becomes narrower when the heat
load grows.
Abstract: Disordered function of maniphalanx and difficulty with
ambulation will occur insofar as a human has a failure in the spinal
marrow. Cervical spondylotic myelopathy as one of the myelopathy
emanates from not only external factors but also increased age. In
addition, the diacrisis is difficult since cervical spondylotic
myelopathy is evaluated by a doctor-s neurological remark and
imaging findings. As a quantitative method for measuring the degree
of disability, hand-operated triangle step test (for short, TST) has
formulated. In this research, a full automatic triangle step counter
apparatus is designed and developed to measure the degree of
disability in an accurate fashion according to the principle of TST. The
step counter apparatus whose shape is a low triangle pole displays the
number of stepping upon each corner. Furthermore, the apparatus has
two modes of operation. Namely, one is for measuring the degree of
disability and the other for rehabilitation exercise. In terms of
usefulness, clinical practice should be executed before too long.
Abstract: Image Compression using Artificial Neural Networks
is a topic where research is being carried out in various directions
towards achieving a generalized and economical network.
Feedforward Networks using Back propagation Algorithm adopting
the method of steepest descent for error minimization is popular and
widely adopted and is directly applied to image compression.
Various research works are directed towards achieving quick
convergence of the network without loss of quality of the restored
image. In general the images used for compression are of different
types like dark image, high intensity image etc. When these images
are compressed using Back-propagation Network, it takes longer
time to converge. The reason for this is, the given image may
contain a number of distinct gray levels with narrow difference with
their neighborhood pixels. If the gray levels of the pixels in an image
and their neighbors are mapped in such a way that the difference in
the gray levels of the neighbors with the pixel is minimum, then
compression ratio as well as the convergence of the network can be
improved. To achieve this, a Cumulative distribution function is
estimated for the image and it is used to map the image pixels. When
the mapped image pixels are used, the Back-propagation Neural
Network yields high compression ratio as well as it converges
quickly.
Abstract: The theoretical prediction of the acoustical
polarization effects in the heterogeneous composites, made of thick
elastic solids with thin nematic films, is presented. The numericalanalytical
solution to the problem of the different wave propagation
exhibits some new physical effects in the low frequency domain: the
appearance of the critical frequency and the existence of the narrow
transition zone where the wave rapidly changes its speed. The
associated wave attenuation is highly perturbed in this zone. We also
show the possible appearance of the critical frequencies where the
attenuation changes the sign. The numerical results of parametrical
analysis are presented and discussed.
Abstract: It is very important to determine reference temperature when convective temperature because it should be used to calculate the temperature potential. This paper deals with the development of a new method that can determine heat transfer coefficient and reference free stream temperature simultaneously, based on transient heat transfer experiments with using two narrow band thermo-tropic liquid crystals (TLC's). The method is validated through error analysis in terms of the random uncertainties in the measured temperatures. It is shown how the uncertainties in heat transfer coefficient and free stream temperature can be reduced. The general method described in this paper is applicable to many heat transfer models with unknown free stream temperature.
Abstract: Texture classification is a trendy and a catchy
technology in the field of texture analysis. Textures, the repeated
patterns, have different frequency components along different
orientations. Our work is based on Texture Classification and its
applications. It finds its applications in various fields like Medical
Image Classification, Computer Vision, Remote Sensing,
Agricultural Field, and Textile Industry. Weed control has a major
effect on agriculture. A large amount of herbicide has been used for
controlling weeds in agriculture fields, lawns, golf courses, sport
fields, etc. Random spraying of herbicides does not meet the exact
requirement of the field. Certain areas in field have more weed
patches than estimated. So, we need a visual system that can
discriminate weeds from the field image which will reduce or even
eliminate the amount of herbicide used. This would allow farmers to
not use any herbicides or only apply them where they are needed. A
machine vision precision automated weed control system could
reduce the usage of chemicals in crop fields. In this paper, an
intelligent system for automatic weeding strategy Multi Resolution
Combined Statistical & spatial Frequency is used to discriminate the
weeds from the crops and to classify them as narrow, little and broad
weeds.
Abstract: In this paper, we first give the representation of the general solution of the following inverse eigenvalue problem (IEP): Given X ∈ Rn×p and a diagonal matrix Λ ∈ Rp×p, find nontrivial real-valued symmetric arrow-head matrices A and B such that AXΛ = BX. We then consider an optimal approximation problem: Given real-valued symmetric arrow-head matrices A, ˜ B˜ ∈ Rn×n, find (A, ˆ Bˆ) ∈ SE such that Aˆ − A˜2 + Bˆ − B˜2 = min(A,B)∈SE (A−A˜2 +B −B˜2), where SE is the solution set of IEP. We show that the optimal approximation solution (A, ˆ Bˆ) is unique and derive an explicit formula for it.
Abstract: The voice signal in Voice over Internet protocol (VoIP) system is processed through the best effort policy based IP network, which leads to the network degradations including delay, packet loss jitter. The work in this paper presents the implementation of finite impulse response (FIR) filter for voice quality improvement in the VoIP system through distributed arithmetic (DA) algorithm. The VoIP simulations are conducted with AMR-NB 6.70 kbps and G.729a speech coders at different packet loss rates and the performance of the enhanced VoIP signal is evaluated using the perceptual evaluation of speech quality (PESQ) measurement for narrowband signal. The results show reduction in the computational complexity in the system and significant improvement in the quality of the VoIP voice signal.
Abstract: Bone marrow-derived stem cells have been widely
studied as an alternative source of stem cells. Mesenchymal stem
cells (MSCs) were mostly investigated and studies showed MSCs can
promote neurogenesis. Little is known about the non-mesenchymal
mononuclear cell fraction, which contains both hematopoietic and
nonhematopoietic cells, including monocytes and endothelial
progenitor cells. This study focused on unfractionated bone marrow
mononuclear cells (BMMCs), which remained 72 h after MSCs were
adhered to the culture plates. We showed that BMMC-conditioned
medium promoted morphological changes of human SH-SY5Y
neuroblastoma cells from an epithelial-like phenotype towards a
neuron-like phenotype as indicated by an increase in neurite
outgrowth, like those observed in retinoic acid (RA)-treated cells.
The result could be explained by the effects of trophic factors
released from BMMCs, as shown in the RT-PCR results that
BMMCs expressed nerve growth factor (NGF), brain-derived
neurotrophic factor (BDNF), and ciliary neurotrophic factor (CNTF).
Similar results on the cell proliferation rate were also observed
between RA-treated cells and cells cultured in BMMC-conditioned
medium, suggesting that cells creased proliferating and differentiated
into a neuronal phenotype. Using real-time RT-PCR, a significantly
increased expression of tyrosine hydroxylase (TH) mRNA in SHSY5Y
cells indicated that BMMC-conditioned medium induced
catecholaminergic identities in differentiated SH-SY5Y cells.
Abstract: Silver nanoparticles were prepared by chemical reduction method. Silver nitrate was taken as the metal precursor and hydrazine hydrate as a reducing agent. The formation of the silver nanoparticles was monitored using UV-Vis absorption spectroscopy. The UV-Vis spectroscopy revealed the formation of silver nanopart├¡cles by exhibing the typical surface plasmon absorption maxima at 418-420 nm from the UV–Vis spectrum. Comparison of theoretical (Mie light scattering theory) and experimental results showed that diameter of silver nanoparticles in colloidal solution is about 60 nm. We have used energy-dispersive spectroscopy (EDX), X-ray diffraction (XRD), transmission electron microscopy (TEM) and, UV–Vis spectroscopy to characterize the nanoparticles obtained. The energy-dispersive spectroscopy (EDX) of the nanoparticles dispersion confirmed the presence of elemental silver signal no peaks of other impurity were detected. The average size and morphology of silver nanoparticles were determined by transmission electron microscopy (TEM). TEM photographs indicate that the nanopowders consist of well dispersed agglomerates of grains with a narrow size distribution (40 and 60 nm), whereas the radius of the individual particles are between 10 and 20 nm. The synthesized nanoparticles have been structurally characterized by X-ray diffraction and transmission high-energy electron diffraction (HEED). The peaks in the XRD pattern are in good agreement with the standard values of the face-centered-cubic form of metallic silver (ICCD-JCPDS card no. 4-0787) and no peaks of other impurity crystalline phases were detected. Additionally, the antibacterial activity of the nanopart├¡culas dispersion was measured by Kirby-Bauer method. The nanoparticles of silver showed high antimicrobial and bactericidal activity against gram positive bacteria such as Escherichia Coli, Pseudimonas aureginosa and staphylococcus aureus which is a highly methicillin resistant strain.
Abstract: This study was conducted to investigate the efficacy
of five herbicides on narrow leaved weeds and growth and yield of
wheat. An experiment was conducted at Agronomic Research
Farm, University of Agriculture Faisalabad. The experiment was
laid out in randomized complete block designee (RCBD) with three
replications. Treatments studied were clodinafop (Topic-15 WG) at
37 g a.i. ha-1, clodinafop (Topaz-15 WG) at 45 g a.i. ha-1,
fenoxaprop-p-ethyl (Puma Super-75 EW) at 45 g a.i. ha-1,
fenoxaprop-p-ethyl (Gramicide-6.9 EW) at 85 g a.i. ha-1,
fenoxaprop-p-ethyl (Chinlima-6.9 EW) at 85 g a.i. ha-1 and weedy
check. Plots treated with fenoxaprop-p-ethyl (Puma Super-75 EW)
at 45 g a.i. ha-1 produced relatively less weed biomass, more plant
height, number of spike bearing tillers, number of grains per spike,
1000-grain weight and grain yield (4.20 t ha-1).
Abstract: The paper presents the influence of the conventional
ploughing tillage technology in comparison with the minimum
tillage, upon the soil properties, weed control and yield in the case of
maize (Zea mays L.), soya-bean (Glycine hispida L.) and winter
wheat (Triticum aestivum L.) in a three years crop rotation. A
research has been conducted at the University of Agricultural
Sciences and Veterinary Medicine Cluj-Napoca, Romania. The use of
minimum soil tillage systems within a three years rotation: maize,
soya-bean, wheat favorites the rise of the aggregates hydro stability
with 5.6-7.5% on a 0-20 cm depth and 5-11% on 20-30 cm depth.
The minimum soil tillage systems – paraplow, chisel or rotary grape
– are polyvalent alternatives for basic preparation, germination bed
preparation and sowing, for fields and crops with moderate loose
requirements being optimized technologies for: soil natural fertility
activation and rationalization, reduction of erosion, increasing the
accumulation capacity for water and realization of sowing in the
optimal period. The soil tillage system influences the productivity
elements of cultivated species and finally the productions thus
obtained. Thus, related to conventional working system, the
productions registered in minimum tillage working represented 89-
97% in maize, 103-112% in soya-bean, 93-99% in winter-wheat. The
results of investigations showed that the yield is a conclusion soil
tillage systems influence on soil properties, plant density assurance
and on weed control. Under minimum tillage systems in the case of
winter weat as an option for replacing classic ploughing, the best
results in terms of quality indices were obtained from version worked
with paraplow, followed by rotary harrow and chisel. At variants
worked with paraplow were obtained quality indices close to those of
the variant worked with plow, and protein and gluten content was
even higher. At Ariesan variety, highest protein content, 12.50% and
gluten, 28.6% was obtained for the variant paraplow.
Abstract: In this paper, we aim to investigate a new stability analysis for discrete-time switched linear systems based on the comparison, the overvaluing principle, the application of Borne-Gentina criterion and the Kotelyanski conditions. This stability conditions issued from vector norms correspond to a vector Lyapunov function. In fact, the switched system to be controlled will be represented in the Companion form. A comparison system relative to a regular vector norm is used in order to get the simple arrow form of the state matrix that yields to a suitable use of Borne-Gentina criterion for the establishment of sufficient conditions for global asymptotic stability. This proposed approach could be a constructive solution to the state and static output feedback stabilization problems.