Abstract: The radio frequency identification (RFID) is a
technology for automatic identification of items, particularly in
supply chain, but it is becoming increasingly important for industrial
applications. Unlike barcode technology that detects the optical
signals reflected from barcode labels, RFID uses radio waves to
transmit the information from an RFID tag affixed to the physical
object. In contrast to today most often use of this technology in
warehouse inventory and supply chain, the focus of this paper is an
overview of the structure of RFID systems used by RFID technology
and it also presents a solution based on the application of RFID for
brand authentication, traceability and tracking, by implementing a
production management system and extending its use to traders.
Abstract: Variations in the growth rate constant of the Listeria
monocytogenes bacterial species were determined at 37°C in
irradiated environments and compared to the situation of a nonirradiated
environment. The bacteria cells, contained in a suspension
made of a nutrient solution of Brain Heart Infusion, were made to
grow at different frequency (2.30e2.60 GHz) and power (0e400
mW) values, in a plug flow reactor positioned in the irradiated
environment. Then the reacting suspension was made to pass into a
cylindrical cuvette where its optical density was read every 2.5
minutes at a wavelength of 600 nm. The obtained experimental data
of optical density vs. time allowed the bacterial growth rate constant
to be derived; this was found to be slightly influenced by microwave
power, but not by microwave frequency; in particular, a minimum
value was found for powers in the 50e150 mW field.
Abstract: With the drastically growth in optical communication
technology, a lossless, low-crosstalk and multifunction optical switch
is most desirable for large-scale photonic network. To realize such a
switch, we have introduced the new architecture of optical switch
that embedded many functions on single device. The asymmetrical
architecture of OXADM consists of 3 parts; selective port, add/drop
operation, and path routing. Selective port permits only the interest
wavelength pass through and acts as a filter. While add and drop
function can be implemented in second part of OXADM architecture.
The signals can then be re-routed to any output port or/and perform
an accumulation function which multiplex all signals onto single path
and then exit to any interest output port. This will be done by path
routing operation. The unique features offered by OXADM has
extended its application to Fiber to-the Home Technology (FTTH),
here the OXADM is used as a wavelength management element in
Optical Line Terminal (OLT). Each port is assigned specifically with
the operating wavelengths and with the dynamic routing management
to ensure no traffic combustion occurs in OLT.
Abstract: In this work we develop an object extraction method
and propose efficient algorithms for object motion characterization.
The set of proposed tools serves as a basis for development of objectbased
functionalities for manipulation of video content. The
estimators by different algorithms are compared in terms of quality
and performance and tested on real video sequences. The proposed
method will be useful for the latest standards of encoding and
description of multimedia content – MPEG4 and MPEG7.
Abstract: In this paper a new method for increasing the speed of
SAGCM-APD is proposed. Utilizing carrier rate equations in
different regions of the structure, a circuit model for the structure is
obtained. In this research, in addition to frequency response, the
effect of added new charge layer on some transient parameters like
slew-rate, rising and falling times have been considered. Finally, by
trading-off among some physical parameters such as different layers
widths and droppings, a noticeable decrease in breakdown voltage
has been achieved. The results of simulation, illustrate some features
of proposed structure improvement in comparison with conventional
SAGCM-APD structures.
Abstract: The technical realization of data transmission using
glass fiber began after the development of diode laser in year 1962.
The erbium doped fiber amplifiers (EDFA's) in high speed networks
allow information to be transmitted over longer distances without
using of signal amplification repeaters. These kinds of fibers are
doped with erbium atoms which have energy levels in its atomic
structure for amplifying light at 1550nm. When a carried signal wave
at 1550nm enters the erbium fiber, the light stimulates the excited
erbium atoms which pumped with laser beam at 980nm as additional
light. The wavelength and intensity of the semiconductor lasers
depend on the temperature of active zone and the injection current.
The present paper shows the effect of the diode lasers temperature
and injection current on the optical amplification. From the results of
in- and output power one may calculate the max. optical gain by
erbium doped fiber amplifier.
Abstract: The inphase/quadrature (I/Q) amplitude and phase
imbalance effects are studied in coherent optical orthogonal
frequency division multiplexing (CO-OFDM) systems. An analytical
model for the I/Q imbalance is developed and supported by
simulation results. The results indicate that the I/Q imbalance degrades the BER performance considerably.
Abstract: A method and apparatus for noninvasive measurement
of blood glucose concentration based on transilluminated laser beam
via the Index Finger has been reported in this paper. This method
depends on atomic gas (He-Ne) laser operating at 632.8nm
wavelength. During measurement, the index finger is inserted into the
glucose sensing unit, the transilluminated optical signal is converted
into an electrical signal, compared with the reference electrical
signal, and the obtained difference signal is processed by signal
processing unit which presents the results in the form of blood
glucose concentration. This method would enable the monitoring
blood glucose level of the diabetic patient continuously, safely and
noninvasively.
Abstract: In this paper, by exploiting a single semiconductor
optical amplifier-Mach Zehnder Interferometer (SOA-MZI), an
integratable all-optical flip-flop (AOFF) is proposed. It is composed
of a SOA-MZI with a bidirectional coupler at the output. Output
signals of both bar and crossbar of the SOA-MZI is fed back to SOAs
located in the arms of the Mach-Zehnder Interferometer (MZI). The
injected photon-rates to the SOAs are modulated by feedback signals
in order to form optical flip-flop. According to numerical analysis,
Gaussian optical pulses with the energy of 15.2 fJ and 20 ps duration
with the full width at half-maximum criterion, can switch the states of
the SR-AOFF. Also simulation results show that the SR-AOFF has
the contrast ratio of 8.5 dB between two states with the transition
time of nearly 20 ps.
Abstract: In this paper, based on the coupled-mode and carrier rate equations, derivation of a dynamic model and numerically analysis of a MQW chirped DFB-SOA all-optical flip-flop is done precisely. We have analyzed the effects of strains of QW and MQW and cross phase modulation (XPM) on the dynamic response, and rise and fall times of the DFB-SOA all optical flip flop. We have shown that strained MQW active region in under an optimized condition into a DFB-SOA with chirped grating can improve the switching ON speed limitation in such a of the device, significantly while the fall time is increased. The values of the rise times for such an all optical flip-flop, are obtained in an optimized condition, areas tr=255ps.
Abstract: Based on a theoretical erbium-doped fiber amplifier
(EDFA) model, we have proposed an application of disturbance
observer(DOB) with proportional/integral/differential(PID) controller
to EDFA for minimizing gain-transient time of wavelength
-division-multiplexing (WDM) multi channels in optical amplifier in
channel add/drop networks. We have dramatically reduced the
gain-transient time to less than 30μsec by applying DOB with PID
controller to the control of amplifier gain. The proposed DOB-based
gain control algorithm for EDFA was implemented as a digital control
system using TI's DSP(TMS320C28346) chip and experimental
results of the system verify the excellent performance of the proposed
gain control methodology.
Abstract: We present a white LED-based optical wireless
communication systems for indoor ubiquitous sensor networks. Each
sensor node could access to the server through the PLC (Power Line
Communication)-Ethernet interface. The proposed system offers a
full-duplex wireless link by using different wavelengths to reduce the
inter-symbol interference between uplink and downlink. Through the
1-to-n optical wireless sensor network and PLC modem, the mobile
terminals send a temperature data to server. The data transmission
speed and distance are 115.2kbps and about 60cm, respectively.
Abstract: This current research focused on development of degradable starch based packaging film with enhanced mechanical properties. A series of low density polyethylene (LDPE)/tapioca starch compounds with various tapioca starch contents were prepared by twin screw extrusion with the addition of maleic anhydride grafted polyethylene as compatibilizer. Palm cooking oil was used as processing aid to ease the blown film process, thus, degradable film can be processed via conventional blown film machine. Studies on their characteristics, mechanical properties and biodegradation were carried out by Fourier Transform Infrared (FTIR) spectroscopy and optical properties, tensile test and exposure to fungi environment respectively. The presence of high starch contents had an adverse effect on the tensile properties of LDPE/tapioca starch blends. However, the addition of compatibilizer to the blends improved the interfacial adhesion between the two materials, hence, improved the tensile properties of the films. High content of starch amount also was found to increase the rate of biodegradability of LDPE/tapioca starch films. It can be proved by exposure of the film to fungi environment. A growth of microbes colony can be seen on the surface of LDPE/tapioca starch film indicates that the granular starch present on the surface of the polymer film is attacked by microorganisms, until most of it is assimilated as a carbon source.
Abstract: Carbon nanotubes (CNTs) are attractive because of
their excellent chemical durability mechanical strength and electrical
properties. Therefore there is interest in CNTs for not only electrical
and mechanical application, but also biological and medical
application.
In this study, the dispersion power of surfactant-treated multiwalled
carbon nanotubes (MWCNTs) and their effect on the antibacterial
activity were examined. Surfactant was used sodium
dodecyl-benzenesulfonate (SDBS). UV-vis absorbance and
transmission electron microscopy(TEM) were used to characterize the
dispersion of MWCNTs in the aqueous phase, showing that the
surfactant molecules had been adsorbed onto the MWCNTs surface.
The surfactant-treated MWCNTs exhibited antimicrobial activities
to streptococcus mutans. The optical density growth curves and viable
cell number determined by the plating method suggested that the
antimicrobial activity of surfactant-treated MWCNTs was both
concentration and treatment time-dependent.
Abstract: Recently, the improvements in processing performance
of a computer and in high speed communication of an optical fiber
have been achieved, so that the amount of data which are processed
by a computer and flowed on a network has been increasing greatly.
However, in a client-server system, since the server receives and
processes the amount of data from the clients through the network, a
load on the server is increasing. Thus, there are needed to introduce
a server with high processing ability and to have a line with high
bandwidth. In this paper, concerning to P2P networks to resolve the
load on a specific server, a criterion called an Indexed-Priority Metric
is proposed and its performance is evaluated. The proposed metric is
to allocate some files to each node. As a result, the load on a specific
server can distribute them to each node equally well. A P2P file
sharing system using the proposed metric is implemented. Simulation
results show that the proposed metric can make it distribute files on
the specific server.
Abstract: Optical emission based on excitonic scattering processes becomes important in dense exciton systems in which the average distance between excitons is of the order of a few Bohr radii but still below the exciton screening threshold. The phenomena due to interactions among excited states play significant role in the emission near band edge of the material. The theory of two-exciton collisions for GaAs/AlGaAs quantum well systems is a mild attempt to understand the physics associated with the optical spectra due to excitonic scattering processes in these novel systems. The four typical processes considered give different spectral shape, peak position and temperature dependence of the emission spectra. We have used the theory of scattering together with the second order perturbation theory to derive the radiative power spontaneously emitted at an energy ħω by these processes. The results arrived at are purely qualitative in nature. The intensity of emitted light in quantum well systems varies inversely to the square of temperature, whereas in case of bulk materials it simply decreases with the temperature.
Abstract: For a generalized Hermite sinosiodal / hyperbolic Gaussian beam passing through an ABCD system with a finite aperture, the propagation properties are derived using the Collins integral. The results are obtained in the form of intensity graphs indicating that previously demonstrated rules of reciprocity are applicable, while the existence of the aperture accelerates this transformation.
Abstract: In this paper, the bond strength of thermal spray
coatings in high speed shafts has been studied. The metallurgical and
mechanical studies has been made on the coated samples and shaft
using optical microscopy, scanning electron microscopy (SEM).
Abstract: Since the driving speed and control accuracy of
commercial optical disk are increasing significantly, it needs an
efficient controller to monitor the track seeking and following
operations of the servo system for achieving the desired data
extracting response. The nonlinear behaviors of the actuator and servo
system of the optical disk drive will influence the laser spot
positioning. Here, the model-free fuzzy control scheme is employed to
design the track seeking servo controller for a d.c. motor driving
optical disk drive system. In addition, the sliding model control
strategy is introduced into the fuzzy control structure to construct a
1-D adaptive fuzzy rule intelligent controller for simplifying the
implementation problem and improving the control performance. The
experimental results show that the steady state error of the track
seeking by using this fuzzy controller can maintain within the track
width (1.6 μm ). It can be used in the track seeking and track
following servo control operations.
Abstract: Optical burst switching (OBS) has been proposed to
realize the next generation Internet based on the wavelength division
multiplexing (WDM) network technologies. In the OBS, the burst
contention is one of the major problems. The deflection routing has
been designed for resolving the problem. However, the deflection
routing becomes difficult to prevent from the burst contentions as the
network load becomes high. In this paper, we introduce a flow rate
control methods to reduce burst contentions. We propose new flow
rate control methods based on the leaky bucket algorithm and
deflection routing, i.e. separate leaky bucket deflection method, and
dynamic leaky bucket deflection method. In proposed methods, edge
nodes which generate data bursts carry out the flow rate control
protocols. In order to verify the effectiveness of the flow rate control in
OBS networks, we show that the proposed methods improve the
network utilization and reduce the burst loss probability through
computer simulations.