Abstract: A new SUZ-4 zeolite membrane with
tetraethlyammonium hydroxide as the template was fabricated on
mullite tube via hydrothermal sol-gel synthesis in a rotating
autoclave reactor. The suitable synthesis condition was SiO2:Al2O3
ratio of 21.2 for 4 days at 155 °C crystallization under autogenous
pressure. The obtained SUZ-4 possessed a high BET surface area of
396.4 m2/g, total pore volume at 2.611 cm3/g, and narrow pore size
distribution with 97 nm mean diameter and 760 nm long of needle
crystal shape. The SUZ-4 layer obtained from seeding crystallization
was thicker than that of without seeds or in situ crystallization.
Abstract: Li1.5Al0.5Ti1.5 (PO4)3(LATP) has received much
attention as a solid electrolyte for lithium batteries. In this study, the
LATP solid electrolyte is prepared by the co-precipitation method
using Li3PO4 as a Li source. The LATP is successfully prepared and
the Li ion conductivities of bulk (inner crystal) and total (inner crystal
and grain boundary) are 1.1 × 10-3 and 1.1 × 10-4 S cm-1, respectively.
These values are comparable to the reported values, in which Li2C2O4
is used as the Li source. It is conclude that the LATP solid electrolyte
can be prepared by the co-precipitation method using Li3PO4 as the Li
source and this procedure has an advantage in mass production over
previous procedure using Li2C2O4 because Li3PO4 is lower price
reagent compared with Li2C2O4.
Abstract: In this work, we present for the first time in our
perception an efficient digital watermarking scheme for mpeg audio
layer 3 files that operates directly in the compressed data domain,
while manipulating the time and subband/channel domain. In
addition, it does not need the original signal to detect the watermark.
Our scheme was implemented taking special care for the efficient
usage of the two limited resources of computer systems: time and
space. It offers to the industrial user the capability of watermark
embedding and detection in time immediately comparable to the real
music time of the original audio file that depends on the mpeg
compression, while the end user/audience does not face any artifacts
or delays hearing the watermarked audio file. Furthermore, it
overcomes the disadvantage of algorithms operating in the PCMData
domain to be vulnerable to compression/recompression attacks,
as it places the watermark in the scale factors domain and not in the
digitized sound audio data. The strength of our scheme, that allows it
to be used with success in both authentication and copyright
protection, relies on the fact that it gives to the users the enhanced
capability their ownership of the audio file not to be accomplished
simply by detecting the bit pattern that comprises the watermark
itself, but by showing that the legal owner knows a hard to compute
property of the watermark.
Abstract: To simulate expected climate change, we implemented a two-factor (temperature and soil moisture) field design in a forest in Ontario, Canada. To manipulate moisture input, we erected rain-exclusion structures. Under each structure, plots were watered with one of three treatments and thermally controlled with three heat treatments to simulate changes in air temperature and rainfall based on the climate model (GCM) predictions for the study area. Environmental conditions (including untreated controls) were monitored tracking air temperature, soil temperature, soil moisture, and photosynthetically active radiation. We measured rainfall and relative humidity at the site outside the rain-exclusion structures. Analyses of environmental conditions demonstrates that the temperature manipulation was most effective at maintaining target temperature during the early part of the growing season, but it was more difficult to keep the warmest treatment at 5º C above ambient by late summer. Target moisture regimes were generally achieved however incoming solar radiation was slightly attenuated by the structures.
Abstract: An array of piezoelectric micro actuators can be used
for radiation of an ultrasonic carrier signal modulated in amplitude
with an acoustic signal, which yields audio frequency applications as
the air acts as a self-demodulating medium. This application is
known as the parametric array. We propose a parametric array with
array elements based on existing piezoelectric micro ultrasonic
transducer (pMUT) design techniques. In order to reach enough
acoustic output power at a desired operating frequency, a proper ratio
between number of array elements and array size needs to be used,
with an array total area of the order of one cm square. The
transducers presented are characterized via impedance, admittance,
noise figure, transducer gain and frequency responses.
Abstract: Although many researchers have studied the flow
hydraulics in compound channels, there are still many complicated problems in determination of their flow rating curves. Many different
methods have been presented for these channels but extending them
for all types of compound channels with different geometrical and
hydraulic conditions is certainly difficult. In this study, by aid of nearly 400 laboratory and field data sets of geometry and flow rating
curves from 30 different straight compound sections and using artificial neural networks (ANNs), flow discharge in compound channels was estimated. 13 dimensionless input variables including relative depth, relative roughness, relative width, aspect ratio, bed
slope, main channel side slopes, flood plains side slopes and berm
inclination and one output variable (flow discharge), have been used
in ANNs. Comparison of ANNs model and traditional method
(divided channel method-DCM) shows high accuracy of ANNs model results. The results of Sensitivity analysis showed that the relative depth with 47.6 percent contribution, is the most effective input parameter for flow discharge prediction. Relative width and
relative roughness have 19.3 and 12.2 percent of importance, respectively. On the other hand, shape parameter, main channel and
flood plains side slopes with 2.1, 3.8 and 3.8 percent of contribution, have the least importance.
Abstract: In this paper, the residual stress of thermal spray
coatings in gas turbine component by curvature method has been
studied. The samples and shaft were coated by hard WC-12Co
cermets using high velocity oxy fuel (HVOF) after preparation in
same conditions. The curvature of coated samples was measured by
using of coordinate measurement machine (CMM). The metallurgical
and Tribological studies has been made on the coated shaft using
optical microscopy and scanning electron microscopy (SEM)
Abstract: This paper propose a new circuit design which
monitor total leakage current during standby mode and generates the
optimal reverse body bias voltage, by using the adaptive body bias
(ABB) technique to compensate die-to-die parameter variations.
Design details of power monitor are examined using simulation
framework in 65nm and 32nm BTPM model CMOS process.
Experimental results show the overhead of proposed circuit in terms
of its power consumption is about 10 μW for 32nm technology and
about 12 μW for 65nm technology at the same power supply voltage
as the core power supply. Moreover the results show that our
proposed circuit design is not far sensitive to the temperature
variations and also process variations. Besides, uses the simple
blocks which offer good sensitivity, high speed, the continuously
feedback loop.
Abstract: Let T and S be a subspace of Cn and Cm, respectively.
Then for A ∈ Cm×n satisfied AT ⊕ S = Cm, the generalized
inverse A(2)
T,S is given by A(2)
T,S = (PS⊥APT )†. In this paper, a
finite formulae is presented to compute generalized inverse A(2)
T,S
under the concept of restricted inner product, which defined as <
A,B >T,S=< PS⊥APT,B > for the A,B ∈ Cm×n. By this
iterative method, when taken the initial matrix X0 = PTA∗PS⊥, the
generalized inverse A(2)
T,S can be obtained within at most mn iteration
steps in absence of roundoff errors. Finally given numerical example
is shown that the iterative formulae is quite efficient.
Abstract: Developing techniques for mobile robot navigation constitutes one of the major trends in the current
research on mobile robotics. This paper develops a local
model network (LMN) for mobile robot navigation. The
LMN represents the mobile robot by a set of locally valid
submodels that are Multi-Layer Perceptrons (MLPs).
Training these submodels employs Back Propagation (BP) algorithm. The paper proposes the fuzzy C-means (FCM) in this scheme to divide the input space to sub regions, and then a submodel (MLP) is identified to represent a particular
region. The submodels then are combined in a unified
structure. In run time phase, Radial Basis Functions (RBFs) are employed as windows for the activated submodels. This
proposed structure overcomes the problem of changing operating regions of mobile robots. Read data are used in all experiments. Results for mobile robot navigation using the
proposed LMN reflect the soundness of the proposed
scheme.
Abstract: In this paper, three dimensional flow characteristic was
presented by a revision of an impeller of an axial turbo fan for
improving the airflow rate and the static pressure. TO consider an
incompressible steady three-dimensional flow, the RANS equations
are used as the governing equations, and the standard k-ε turbulence
model is chosen. The pitch angles of 44°, 54°, 59°, and 64° are
implemented for the numerical model. The numerical results show that
airflow rates of each pitch angle are 1,175 CMH, 1,270 CMH, 1,340
CMH, and 800 CMH, respectively. The difference of the static
pressure at impeller inlet and outlet are 120 Pa, 214 Pa, 242 Pa, and 60
Pa according to respective pitch angles. It means that the 59° of the
impeller pitch angle is optimal to improve the airflow rate and the
static pressure.
Abstract: A 3.5-bit stage of the CMOS pipelined ADC is proposed. In this report, the main part of 3.5-bit stage ADC is introduced. How the MDAC, comparator and encoder worked and designed are shown in details. Besides, an OTA which is used in fully differential pipelined ADC was described. Using gain-boost architecture with differential amplifier, this OTA achieve high-gain and high-speed. This design was using CMOS 0.18um process and simulation in Cadence. The result of the simulation shows that the OTA has a gain up to 80dB, the unity gain bandwidth of about 1.138GHz with 2pF load.
Abstract: This study explores perceptions of English as a Foreign
Language (EFL) learners on using computer mediated communication
technology in their learner of English. The data consists of
observations of both synchronous and asynchronous communication
participants engaged in for over a period of 4 months, which included
online, and offline communication protocols, open-ended interviews
and reflection papers composed by participants.
Content analysis of interview data and the written documents listed
above, as well as, member check and triangulation techniques are the
major data analysis strategies. The findings suggest that participants
generally do not benefit from computer-mediated communication in
terms of its effect in learning a foreign language. Participants regarded
the nature of CMC as artificial, or pseudo communication that did not
aid their authentic communicational skills in English. The results of
this study sheds lights on insufficient and inconclusive findings, which
most quantitative CMC studies previously generated.
Abstract: Interaction effects of xanthan gum (XG), carboxymethyl
cellulose (CMC), and locust bean gum (LBG) on the flow properties
of oil-in-water emulsions were investigated by a mixture design
experiment. Blends of XG, CMC and LBG were prepared according
to an augmented simplex-centroid mixture design (10 points) and used
at 0.5% (wt/wt) in the emulsion formulations. An appropriate
mathematical model was fitted to express each response as a function
of the proportions of the blend components that are able to
empirically predict the response to any blend of combination of the
components. The synergistic interaction effect of the ternary
XG:CMC:LBG blends at approximately 33-67% XG levels was
shown to be much stronger than that of the binary XG:LBG blend at
50% XG level (p < 0.05). Nevertheless, an antagonistic interaction
effect became significant as CMC level in blends was more than 33%
(p < 0.05). Yield stress and apparent viscosity (at 10 s-1) responses
were successfully fitted with a special quartic model while flow
behaviour index and consistency coefficient were fitted with a full
quartic model (R2
adjusted ≥ 0.90). This study found that a mixture
design approach could serve as a valuable tool in better elucidating
and predicting the interaction effects beyond the conventional twocomponent
blends.
Abstract: The most planted cover crops in the Czech Republic
are mustard (Sinapis alba) and phacelia (Phacelia tanacetifolia
Benth.). A field trial was executed to evaluate root system size (RSS)
in eight varieties of mustard and five varieties of phacelia on two
locations, in three BBCH phases and in two years. The relationship
between RSS and aboveground biomass was inquired. The root
system was assessed by measuring its electric capacity. Aboveground
mass and root samples to be evaluated by means of a digital image
analysis were recovered in the BBCH phase 70. The yield of
aboveground biomass of mustard was always statistically
significantly higher than that of phacelia. Mustard showed a
statistically significant negative correlation between root length
density (RLD) within 10 cm and aboveground biomass weight (r = -
0.46*). Phacelia featured a statistically significant correlation
between aboveground biomass production and nitrate nitrogen
content in soil (r=0.782**).
Abstract: In this document, we have proposed a robust
conceptual strategy, in order to improve the robustness against the manufacturing defects and thus the reliability of logic CMOS circuits. However, in order to enable the use of future CMOS
technology nodes this strategy combines various types of design:
DFR (Design for Reliability), techniques of tolerance: hardware
redundancy TMR (Triple Modular Redundancy) for hard error
tolerance, the DFT (Design for Testability. The Results on largest ISCAS and ITC benchmark circuits show that our approach improves
considerably the reliability, by reducing the key factors, the area costs and fault tolerance probability.
Abstract: The paper reports on the results of experimental and
numerical study of nonstationary swirling flow in an isothermal
model of vortex burner. It has been identified that main source of the
instability is related to a precessing vortex core (PVC) phenomenon.
The PVC induced flow pulsation characteristics such as precession
frequency and its variation as a function of flowrate and swirl number
have been explored making use of acoustic probes. Additionally
pressure transducers were used to measure the pressure drops on the
working chamber and across the vortex flow. The experiments have
been included also the mean velocity measurements making use of a
laser-Doppler anemometry. The features of instantaneous flowfield
generated by the PVC were analyzed employing a commercial CFD
code (Star-CCM+) based on Detached Eddy Simulation (DES)
approach. Validity of the numerical code has been checked by
comparison calculated flowfield data with the obtained experimental
results. It has been confirmed particularly that the CFD code applied
correctly reproduces the flow features.
Abstract: The purpose of this research is to develop and apply the
RSCMAC to enhance the dynamic accuracy of Global Positioning
System (GPS). GPS devices provide services of accurate positioning,
speed detection and highly precise time standard for over 98% area on
the earth. The overall operation of Global Positioning System includes
24 GPS satellites in space; signal transmission that includes 2
frequency carrier waves (Link 1 and Link 2) and 2 sets random
telegraphic codes (C/A code and P code), on-earth monitoring stations
or client GPS receivers. Only 4 satellites utilization, the client position
and its elevation can be detected rapidly. The more receivable
satellites, the more accurate position can be decoded. Currently, the
standard positioning accuracy of the simplified GPS receiver is greatly
increased, but due to affected by the error of satellite clock, the
troposphere delay and the ionosphere delay, current measurement
accuracy is in the level of 5~15m. In increasing the dynamic GPS
positioning accuracy, most researchers mainly use inertial navigation
system (INS) and installation of other sensors or maps for the
assistance. This research utilizes the RSCMAC advantages of fast
learning, learning convergence assurance, solving capability of
time-related dynamic system problems with the static positioning
calibration structure to improve and increase the GPS dynamic
accuracy. The increasing of GPS dynamic positioning accuracy can be
achieved by using RSCMAC system with GPS receivers collecting
dynamic error data for the error prediction and follows by using the
predicted error to correct the GPS dynamic positioning data. The
ultimate purpose of this research is to improve the dynamic positioning
error of cheap GPS receivers and the economic benefits will be
enhanced while the accuracy is increased.
Abstract: Wavelet neural networks (WNNs) have emerged as a vital alternative to the vastly studied multilayer perceptrons (MLPs) since its first implementation. In this paper, we applied various clustering algorithms, namely, K-means (KM), Fuzzy C-means (FCM), symmetry-based K-means (SBKM), symmetry-based Fuzzy C-means (SBFCM) and modified point symmetry-based K-means (MPKM) clustering algorithms in choosing the translation parameter of a WNN. These modified WNNs are further applied to the heterogeneous cancer classification using benchmark microarray data and were compared against the conventional WNN with random initialization method. Experimental results showed that a WNN classifier with the MPKM algorithm is more precise than the conventional WNN as well as the WNNs with other clustering algorithms.
Abstract: ZnO nanostructures including nanowires, nanorods,
and nanoneedles were successfully deposited on GaAs substrates,
respectively, by simple two-step chemical method for the first time. A
ZnO seed layer was firstly pre-coated on the O2-plasma treated
substrate by sol-gel process, followed by the nucleation of ZnO
nanostructures through hydrothermal synthesis. Nanostructures with
different average diameter (15-250 nm), length (0.9-1.8 μm), density
(0.9-16×109 cm-2) were obtained via adjusting the growth time and
concentration of precursors. From the reflectivity spectra, we
concluded ordered and taper nanostructures were preferential for
photovoltaic applications. ZnO nanoneedles with an average diameter
of 106 nm, a moderate length of 2.4 μm, and the density of 7.2×109
cm-2 could be synthesized in the concentration of 0.04 M for 18 h.
Integrated with the nanoneedle array, the power conversion efficiency
of single junction solar cell was increased from 7.3 to 12.2%,
corresponding to a 67% improvement.