Abstract: The present study is concerned with the problem of determining the shape of the free surface flow in a hydraulic channel which has an uneven bottom. For the mathematical formulation of the problem, the fluid of the two-dimensional irrotational steady flow in water is assumed inviscid and incompressible. The solutions of the nonlinear problem are obtained by using the usual conformal mapping theory and Hilbert’s technique. An experimental study, for comparing the obtained results, has been conducted in a hydraulic channel (subcritical regime and supercritical regime).
Abstract: The 3D printing is a combination of digital technology, material science, intelligent manufacturing and control of opto-mechatronics systems. It is called the third industrial revolution from the view of the Economist Journal. A color 3D printing machine may provide the necessary support for high value-added industrial and commercial design, architectural design, personal boutique, and 3D artist’s creation. The main goal of this paper is to develop photo-curable color 3D manufacturing technology and system implementation. The key technologies include (1) Photo-curable color 3D additive manufacturing processes development and materials research (2) Piezo type ink-jet head control and Opto-mechatronics integration technique of the photo-curable color 3D laminated manufacturing system. The proposed system is integrated with single Piezo type ink-jet head with two individual channels for two primary UV light curable color resins which can provide for future colorful 3D printing solutions. The main research results are 16 grey levels and grey resolution of 75 dpi.
Abstract: This paper presented a study of three algorithms, the
equalization algorithm to equalize the transmission channel with ZF
and MMSE criteria, application of channel Bran A, and adaptive
filtering algorithms LMS and RLS to estimate the parameters of the
equalizer filter, i.e. move to the channel estimation and therefore
reflect the temporal variations of the channel, and reduce the error in
the transmitted signal. So far the performance of the algorithm
equalizer with ZF and MMSE criteria both in the case without noise,
a comparison of performance of the LMS and RLS algorithm.
Abstract: In this paper, the dependence of soliton pulses with
respect to phase in a 10Gbps, single channel, dispersion
uncompensated telecommunication system was studied. The
characteristic feature of periodic soliton interaction was noted at the
Interaction point (I=6202.5Km) in one collision length of L=12405.1
Km. The interaction point is located for 10Gbps system with an
initial relative spacing (qo) of soliton as 5.28 using Perturbation
theory. It is shown that, when two in-phase solitons are launched,
they interact at the point I=6202.5 Km, but the interaction could be
restricted with introduction of different phase initially. When the
phase of the input solitons increases, the deviation of soliton pulses at
the ‘I’ also increases. We have successfully demonstrated this effect
in a telecommunication set-up in terms of Quality factor (Q), where
the Q=0 for in-phase soliton. The Q was noted to be 125.9, 38.63,
47.53, 59.60, 161.37, and 78.04 for different phases such as 10o, 20o,
30o, 45o, 60o and 90o degrees respectively at Interaction point (I).
Abstract: This paper presents an optimization method for
reducing the number of input channels and the complexity of the
feed-forward NARX neural network (NN) without compromising the
accuracy of the NN model. By utilizing the correlation analysis
method, the most significant regressors are selected to form the input
layer of the NN structure. An application of vehicle dynamic model
identification is also presented in this paper to demonstrate the
optimization technique and the optimal input layer structure and the
optimal number of neurons for the neural network is investigated.
Abstract: Optical biosensors have become a powerful detection
and analysis tool for wide-ranging applications in biomedical research,
pharmaceuticals and environmental monitoring. This study carried out
the computational fluid dynamics (CFD)-based simulations to explore
the dispersion phenomenon in the micro channel of an optical
biosensor. The predicted time sequences of concentration contours
were utilized to better understand the dispersion development occurred
in different geometric shapes of micro channels. The simulation results
showed the surface concentrations at the sensing probe (with the best
performance of a grating coupler) in respect of time to appraise the
dispersion effect and therefore identify the design configurations
resulting in minimum dispersion.
Abstract: Roles of the vegetation to mitigate the erosion of the
stream bed or to facilitate the deposition of the fine sediments by the
species of the aquatic plants were presented. Field investigation on the
estimation of the change of the bed level and the estimation of the flow
characteristics were performed. The results showed that Phragmites
japonica has the mitigation function of 0.3m-0.4m of the erosion in the
range of higher than 1.0m/s of flow velocity at the vegetated region.
Phragmites communis has the mitigation function of 0.2m-0.3m of the
erosion in the range of higher than 0.7m/s of flow velocity at the
vegetated region. Salix gracilistyla has greater role than Phragmites
japonica and Phragmites communis to sustain the stable channel. It
has the mitigation function of 0.4m-0.5m of the erosion in the range of
higher than 1.4m/s of flow velocity. Miscanthus sacchariflorus has a
weak role compared with that of Phragmites japonica and Salix
gracilistyla, but it has still function for sustaining the stable bed. From
these results, the vegetation has effective roles to mitigate the erosion
or to facilitate the deposition of the stream bed.
Abstract: In this study, firstly democratic thoughts which
directly or indirectly affect economic development and/or the
interaction between authoritarian regimes and the economic
development and the direction and channels of this interaction were
studied and then the study tried to determine how democracy affects
economic development. It was concluded that the positive
contributions of democracy to economic development were more
determinant than the effects that were either negative or restrictive in
terms of development. When compared to autocracy, since
democracy is more successful in managing social conflicts, ensuring
political stability and preventing social disasters such as famine, it
contributes more to economic development. Democracy also
facilitates delegation of authority, provides a stable investment
environment and accelerates mobilization of resources in accordance
with economic growth/development. Democracy leads to an increase
in human capital accumulation and increases the growth rate through
reducing income inequality. It can be said that democratic regimes
are the most appropriate ones in terms of increasing economic
performance and supporting economic development through their
strong institutional structures and the assurance they will ensure in
property rights.
Abstract: The paper presents new results concerning selection of
optimal information fusion formula for ensembles of C-OTDR
channels. The goal of information fusion is to create an integral
classificator designed for effective classification of seismoacoustic
target events. The LPBoost (LP-β and LP-B variants), the Multiple
Kernel Learning, and Weighing of Inversely as Lipschitz Constants
(WILC) approaches were compared. The WILC is a brand new
approach to optimal fusion of Lipschitz Classifiers Ensembles.
Results of practical usage are presented.
Abstract: Experimental studies to investigate the depth of the
scour conducted at a side-weir intersection located at the 1800 curved
flume which located Hydraulic Laboratory of Yıldız Technical
University, Istanbul, Turkey. Side weirs were located at the middle of
the straight part of the main channel. Three different lengths (25, 40
and 50 cm) and three different weir crest height (7, 10 and 12 cm) of
the side weir placed on the side weir station. There is no scour when
the material is only kaolin. Therefore, the cohesive bed was prepared
by properly mixing clay material (kaolin) with 31% sand in all
experiments. Following 24h consolidation time, in order to observe
the effect of flow intensity on the scour depth, experiments were
carried out for five different upstream Froude numbers in the range of
0.33-0.81.
As a result of this study the relation between scour depth and
upstream flow intensity as a function of time have been established.
The longitudinal velocities decreased along the side weir; towards the
downstream due to overflow over the side-weirs. At the beginning,
the scour depth increases rapidly with time and then asymptotically
approached constant values in all experiments for all side weir
dimensions as in non-cohesive sediment. Thus, the scour depth
reached equilibrium conditions. Time to equilibrium depends on the
approach flow intensity and the dimensions of side weirs. For
different heights of the weir crest, dimensionless scour depths
increased with increasing upstream Froude number. Equilibrium
scour depths which formed 7 cm side-weir crest height were obtained
higher than that of the 12 cm side-weir crest height. This means when
side-weir crest height increased equilibrium scour depths decreased.
Although the upstream side of the scour hole is almost vertical, the
downstream side of the hole is inclined.
Abstract: Channel sections are widely used in practice as beams.
However, design rules for eccentrically loaded (not through shear
center) beams with channel cross- sections are not available in
Eurocode 3. This paper compares the ultimate loads based on the
adjusted design rules for lateral torsional buckling of eccentrically
loaded channel beams in bending to the ultimate loads obtained with
Finite Element (FE) simulations on the basis of a parameter study.
Based on the proposed design rule, this study has led to a new design
rule which conforms to Eurocode 3.
Abstract: This paper reports a novel actuating design that uses
the shear deformation of a piezoelectric actuator to deflect a
bulge-diaphragm for driving an array microdroplet ejector. In essence,
we employed a circular-shaped actuator poled radial direction with
remnant polarization normal to the actuating electric field for inducing
the piezoelectric shear effect. The array microdroplet ejector consists
of a shear type piezoelectric actuator, a vibration plate, two chamber
plates, two channel plates and a nozzle plate. The vibration, chamber
and nozzle plate components are fabricated using nickel
electroforming technology, whereas the channel plate is fabricated by
etching of stainless steel. The diaphragm displacement was measured
by the laser two-dimensional scanning vibrometer. The ejected
droplets of the microejector were also observed via an optic
visualization system.
Abstract: We propose new multiple-channel piezoelectric (PZT)
actuated tunable optical filter based on racetrack multi-ring
resonators for wavelength de-multiplexing network applications. We
design tunable eight-channel wavelength de-multiplexer consisting of
eight cascaded PZT actuated tunable multi-ring resonator filter with a
channel spacing of 1.6nm. The filter for each channel is basically
structured on a suspended beam, sandwiched with piezoelectric
material and built in integrated ring resonators which are placed on
the middle of the beam to gain uniform stress and linearly varying
longitudinal strain. A reference single mode serially coupled multi
stage racetrack ring resonator with the same radii and coupling length
is designed with a line width of 0.8974nm with a flat top pass band at
1dB of 0.5205nm and free spectral range of about 14.9nm. In each
channel, a small change in the perimeter of the rings is introduced to
establish the shift in resonance wavelength as per the defined channel
spacing. As a result, when a DC voltage is applied, the beams will
elongate, which involves mechanical deformation of the ring
resonators that induces a stress and a strain, which brings a change in
refractive index and perimeter of the rings leading to change in the
output spectrum shift providing the tunability of central wavelength
in each channel. Simultaneous wave length shift as high as
45.54pm/
Abstract: High density electrical prospecting has been widely
used in groundwater investigation, civil engineering and
environmental survey. For efficient inversion, the forward modeling
routine, sensitivity calculation, and inversion algorithm must be
efficient. This paper attempts to provide a brief summary of the past
and ongoing developments of the method. It includes reviews of the
procedures used for data acquisition, processing and inversion of
electrical resistivity data based on compilation of academic literature.
In recent times there had been a significant evolution in field survey
designs and data inversion techniques for the resistivity method. In
general 2-D inversion for resistivity data is carried out using the
linearized least-square method with the local optimization technique
.Multi-electrode and multi-channel systems have made it possible to
conduct large 2-D, 3-D and even 4-D surveys efficiently to resolve
complex geological structures that were not possible with traditional
1-D surveys. 3-D surveys play an increasingly important role in very
complex areas where 2-D models suffer from artifacts due to off-line
structures. Continued developments in computation technology, as
well as fast data inversion techniques and software, have made it
possible to use optimization techniques to obtain model parameters to
a higher accuracy. A brief discussion on the limitations of the
electrical resistivity method has also been presented.
Abstract: An adaptive nonparametric method is proposed for
stable real-time detection of seismoacoustic sources in multichannel
C-OTDR systems with a significant number of channels. This
method guarantees given upper boundaries for probabilities of Type I
and Type II errors. Properties of the proposed method are rigorously
proved. The results of practical applications of the proposed method
in a real C-OTDR-system are presented in this report.
Abstract: One of the crucial parameters of digital cryptographic
systems is the selection of the keys used and their distribution. The
randomness of the keys has a strong impact on the system’s security
strength being difficult to be predicted, guessed, reproduced, or
discovered by a cryptanalyst. Therefore, adequate key randomness
generation is still sought for the benefit of stronger cryptosystems.
This paper suggests an algorithm designed to generate and test
pseudo random number sequences intended for cryptographic
applications. This algorithm is based on mathematically manipulating
a publically agreed upon information between sender and receiver
over a public channel. This information is used as a seed for
performing some mathematical functions in order to generate a
sequence of pseudorandom numbers that will be used for
encryption/decryption purposes. This manipulation involves
permutations and substitutions that fulfill Shannon’s principle of
“confusion and diffusion”. ASCII code characters were utilized in the
generation process instead of using bit strings initially, which adds
more flexibility in testing different seed values. Finally, the obtained
results would indicate sound difficulty of guessing keys by attackers.
Abstract: Reflux condensation occurs in vertical channels and tubes when there is an upward core flow of vapour (or gas-vapour mixture) and a downward flow of the liquid film. The understanding of this condensation configuration is crucial in the design of reflux condensers, distillation columns, and in loss-of-coolant safety analyses in nuclear power plant steam generators. The unique feature of this flow is the upward flow of the vapour-gas mixture (or pure vapour) that retards the liquid flow via shear at the liquid-mixture interface. The present model solves the full, elliptic governing equations in both the film and the gas-vapour core flow. The computational mesh is non-orthogonal and adapts dynamically the phase interface, thus produces a sharp and accurate interface. Shear forces and heat and mass transfer at the interface are accounted for fundamentally. This modeling is a big step ahead of current capabilities by removing the limitations of previous reflux condensation models which inherently cannot account for the detailed local balances of shear, mass, and heat transfer at the interface. Discretisation has been done based on finite volume method and co-located variable storage scheme. An in-house computer code was developed to implement the numerical solution scheme. Detailed results are presented for laminar reflux condensation from steam-air mixtures flowing in vertical parallel plate channels. The results include velocity and gas mass fraction profiles, as well as axial variations of film thickness.
Abstract: Cesium iodide (CsI) melt was injected into anodic aluminum oxide (AAO) template and was solidified to CsI column. The controllable AAO channel size (10~500 nm) can makes CsI column size from 10 to 500 nm in diameter. In order to have a shorter light irradiate from each singe CsI column top to bottom the AAO template was coated a TiO2 nano-film. The TiO2 film acts a refraction film and makes X-ray has a shorter irradiation path in the CsI crystal making a stronger the photo-electron signal. When the incidence light irradiate from air (R=1.0) to CsI’s first surface (R=1.84) the first refraction happen, the first refraction continue into TiO2 film (R=2.88) and produces the low angle of the second refraction. Then the second refraction continue into AAO wall (R=1.78) and produces the third refraction after refractions between CsI and AAO wall (R=1.78) produce the fourth refraction. The incidence light through TiO2 filmand the first surface of CsI then arrive to the second surface of CsI. Therefore, the TiO2 film can has shorter refraction path of incidence light and increase the photo-electron conversion efficiency.
Abstract: The paper presents a new method for efficient
innovation process management. Even though the innovation
management methods, tools and knowledge are well established and
documented in literature, most of the companies still do not manage it
efficiently. Especially in SMEs the front end of innovation - problem
identification, idea creation and selection - is often not optimally
performed. Our eMIPS methodology represents a sort of "umbrella
methodology" - a well-defined set of procedures, which can be
dynamically adapted to the concrete case in a company. In daily
practice, various methods (e.g. for problem identification and idea
creation) can be applied, depending on the company's needs. It is
based on the proactive involvement of the company's employees
supported by the appropriate methodology and external experts. The
presented phases are performed via a mixture of face-to-face
activities (workshops) and online (eLearning) activities taking place
in eLearning Moodle environment and using other e-communication
channels. One part of the outcomes is an identified set of
opportunities and concrete solutions ready for implementation. The
other also very important result is connected to innovation
competences for the participating employees related with concrete
tools and methods for idea management. In addition, the employees
get a strong experience for dynamic, efficient and solution oriented
managing of the invention process. The eMIPS also represents a way
of establishing or improving the innovation culture in the
organization. The first results in a pilot company showed excellent
results regarding the motivation of participants and also as to the
results achieved.
Abstract: We have conducted the optimal synthesis of rootmean-
squared objective filter to estimate the state vector in the case if
within the observation channel with memory the anomalous noises
with unknown mathematical expectation are complement in the
function of the regular noises. The synthesis has been carried out for
linear stochastic systems of continuous - time.