Abstract: This paper reports on the response of a fiber-optic
sensing probe to small concentrations of hydrogen peroxide (H2O2)
vapor at room temperature. H2O2 has extensive applications in industrial and medical
environments. Conversely, H2O2 can be a health hazard by itself. For
example, H2O2 induces cellular damage in human cells and its
presence can be used to diagnose illnesses such as asthma and human
breast cancer. Hence, development of reliable H2O2 sensor is of vital
importance to detect and measure this species. Ferric ferrocyanide, referred to as Prussian Blue (PB), was
deposited on the tip of a multimode optical fiber through the single
source precursor technique and served as an indicator of H2O2 in a
spectroscopic manner. Sensing tests were performed in H2O2-H2O
vapor mixtures with different concentrations of H2O2. The results of sensing tests show the sensor is able to detect H2O2
concentrations in the range of 50.6 ppm to 229.5 ppm. Furthermore,
the sensor response to H2O2 concentrations is linear in a log-log scale
with the adjacent R-square of 0.93. This sensing behavior allows us
to detect and quantify the concentration of H2O2 in the vapor phase.
Abstract: The end of the line controls of the finished products in
the automotive industry is important. The control that has been
conducted with the manual methods for the sliding doors tracks is not
sufficient and faulty products cannot be identified. As a result, the
customer has the faulty products. In the scope of this study, the
design criteria of the PLC integrated modular end of line control unit
has been examined, designed and manufactured to make the control
of the 10 different track profile to 2 different vehicles with an
objective to minimize the salvage costs by obtaining more sensitive,
certain and accurate measurement results. In the study that started
with literature and patent review, the design inputs have been
specified, the technical concept has been developed, computer
supported mechanic design, control system and automation design,
design review and design improvement have been made. Laser
analog sensors at high sensitivity, probes and modular blocks have
been used in the unit. The measurement has been conducted in the
system and it is observed that measurement results are more sensitive
than the previous methods that we use.
Abstract: A novel Active Flap System (AFS) has been developed
at DTU Wind Energy, as a result of a 3-year R&D project following
almost 10 years of innovative research in this field. The full scale AFS
comprises an active deformable trailing edge has been tested at the
unique rotating test facility at the Risø Campus of DTU Wind Energy
in Denmark. The design and instrumentation of the wing section and
the AFS are described. The general description and objectives of the
rotating test rig at the Risø campus of DTU are presented, along
with an overview of sensors on the setup and the test cases. The
post-processing of data is discussed and results of steady, flap step
and azimuth control flap cases are presented.
Abstract: To decrease the grating scale thermal expansion error,
a novel method which based on multiple temperature detection is
proposed. Several temperature sensors are installed on the grating
scale and the temperatures of these sensors are recorded. The
temperatures of every point on the grating scale are calculated by
interpolating between adjacent sensors. According to the thermal
expansion principle, the grating scale thermal expansion error model
can be established by doing the integral for the variations of position
and temperature. A novel compensation method is proposed in this
paper. By applying the established error model, the grating scale
thermal expansion error is decreased by 90% compared with no
compensation. The residual positioning error of the grating scale is
less than 15μm/10m and the accuracy of the machine tool is
significant improved.
Abstract: As smartphones are equipped with various sensors,
there have been many studies focused on using these sensors to create
valuable applications. Human activity recognition is one such
application motivated by various welfare applications, such as the
support for the elderly, measurement of calorie consumption, lifestyle
and exercise patterns analyses, and so on. One of the challenges one
faces when using smartphone sensors for activity recognition is that
the number of sensors should be minimized to save battery power. In
this paper, we show that a fairly accurate classifier can be built that
can distinguish ten different activities by using only a single sensor
data, i.e., the smartphone accelerometer data. The approach that we
adopt to deal with this twelve-class problem uses various methods.
The features used for classifying these activities include not only the
magnitude of acceleration vector at each time point, but also the
maximum, the minimum, and the standard deviation of vector
magnitude within a time window. The experiments compared the
performance of four kinds of basic multi-class classifiers and the
performance of four kinds of ensemble learning methods based on
three kinds of basic multi-class classifiers. The results show that
while the method with the highest accuracy is ECOC based on
Random forest.
Abstract: In order to obtain efficient pollutants removal in
small-scale wastewater treatment plants, uniform water flow has to be
achieved. The experimental setup, designed for treating high-load
wastewater (leachate), consists of two aerobic biological reactors and
a lamellar settler. Both biological tanks were aerated by using three
different types of aeration systems - perforated pipes, membrane air
diffusers and tube ceramic diffusers. The possibility of homogenizing
the water mass with each of the air diffusion systems was evaluated
comparatively. The oxygen concentration was determined by optical
sensors with data logging. The experimental data was analyzed
comparatively for all three different air dispersion systems aiming to
identify the oxygen concentration variation during different
operational conditions. The Oxygenation Capacity was calculated for
each of the three systems and used as performance and selection
parameter. The global mass transfer coefficients were also evaluated
as important tools in designing the aeration system. Even though
using the tubular porous diffusers leads to higher oxygen
concentration compared to the perforated pipe system (which
provides medium-sized bubbles in the aqueous solution), it doesn’t
achieve the threshold limit of 80% oxygen saturation in less than 30
minutes. The study has shown that the optimal solution for the
studied configuration was the radial air diffusers which ensure an
oxygen saturation of 80% in 20 minutes. An increment of the values
was identified when the air flow was increased.
Abstract: This research presents the main ideas to implement an
intelligent system composed by communicating wireless sensors
measuring environmental data linked to drought indicators (such as
air temperature, soil moisture , etc...). On the other hand, the setting
up of a spatio temporal database communicating with a Web mapping
application for a monitoring in real time in activity 24:00 /day, 7
days/week is proposed to allow the screening of the drought
parameters time evolution and their extraction. Thus this system
helps detecting surfaces touched by the phenomenon of drought.
Spatio-temporal conceptual models seek to answer the users who
need to manage soil water content for irrigating or fertilizing or other
activities pursuing crop yield augmentation. Effectively, spatiotemporal
conceptual models enable users to obtain a diagram of
readable and easy data to apprehend. Based on socio-economic
information, it helps identifying people impacted by the phenomena
with the corresponding severity especially that this information is
accessible by farmers and stakeholders themselves. The study will be
applied in Siliana watershed Northern Tunisia.
Abstract: Nine Degrees of Freedom (9 DOF) systems are
already in development in many areas. In this paper, an integrated
pressure sensor is proposed that will make use of an already existing
monolithic 9 DOF inertial MEMS platform. Capacitive pressure
sensors can suffer from limited sensitivity for a given size of
membrane. This novel pressure sensor design increases the sensitivity
by over 5 times compared to a traditional array of square diaphragms
while still fitting within a 2 mm x 2 mm chip and maintaining a fixed
static capacitance. The improved design uses one large diaphragm
supported by pillars with fixed electrodes placed above the areas of
maximum deflection. The design optimization increases the
sensitivity from 0.22 fF/kPa to 1.16 fF/kPa. Temperature sensitivity
was also examined through simulation.
Abstract: The MEMS pressure sensor has been introduced and
presented in this paper. The types of pressure sensor and its theory of
operation are also included. The latest MEMS technology, the
fabrication processes of pressure sensor are explored and discussed.
Besides, various device applications of pressure sensor such as tire
pressure-monitoring system, diesel particulate filter and others are
explained. Due to further miniaturization of the device nowadays, the
pressure sensor with nanotechnology (NEMS) is also reviewed. The
NEMS pressure sensor is expected to have better performance as well
as lower in its cost. It has gained an excellent popularity in many
applications.
Abstract: The lifetime of a wireless sensor network can be
effectively increased by using scheduling operations. Once the
sensors are randomly deployed, the task at hand is to find the largest
number of disjoint sets of sensors such that every sensor set provides
complete coverage of the target area. At any instant, only one of these
disjoint sets is switched on, while all other are switched off. This
paper proposes a heuristic search method to find the maximum
number of disjoint sets that completely cover the region. A
population of randomly initialized members is made to explore the
solution space. A set of heuristics has been applied to guide the
members to a possible solution in their neighborhood. The heuristics
escalate the convergence of the algorithm. The best solution explored
by the population is recorded and is continuously updated. The
proposed algorithm has been tested for applications which require
sensing of multiple target points, referred to as point coverage
applications. Results show that the proposed algorithm outclasses the
existing algorithms. It always finds the optimum solution, and that
too by making fewer number of fitness function evaluations than the
existing approaches.
Abstract: Despite the advances made in various new
technologies, application of these technologies for agriculture still
remains a formidable task, as it involves integration of diverse
domains for monitoring the different process involved in agricultural
management. Advances in ambient intelligence technology represents
one of the most powerful technology for increasing the yield of
agricultural crops and to mitigate the impact of water scarcity,
climatic change and methods for managing pests, weeds and diseases.
This paper proposes a GPS-assisted, machine to machine solutions
that combine information collected by multiple sensors for the
automated management of paddy crops. To maintain the economic
viability of paddy cultivation, the various techniques used in
agriculture are discussed and a novel system which uses ambient
intelligence technique is proposed in this paper. The ambient
intelligence based agricultural system gives a great scope.
Abstract: This study suggests the estimation method of stress
distribution for the beam structures based on TLS (Terrestrial Laser
Scanning). The main components of method are the creation of the
lattices of raw data from TLS to satisfy the suitable condition and
application of CSSI (Cubic Smoothing Spline Interpolation) for
estimating stress distribution. Estimation of stress distribution for the
structural member or the whole structure is one of the important
factors for safety evaluation of the structure. Existing sensors which
include ESG (Electric strain gauge) and LVDT (Linear Variable
Differential Transformer) can be categorized as contact type sensor
which should be installed on the structural members and also there are
various limitations such as the need of separate space where the
network cables are installed and the difficulty of access for sensor
installation in real buildings. To overcome these problems inherent in
the contact type sensors, TLS system of LiDAR (light detection and
ranging), which can measure the displacement of a target in a long
range without the influence of surrounding environment and also get
the whole shape of the structure, has been applied to the field of
structural health monitoring. The important characteristic of TLS
measuring is a formation of point clouds which has many points
including the local coordinate. Point clouds are not linear distribution
but dispersed shape. Thus, to analyze point clouds, the interpolation is
needed vitally. Through formation of averaged lattices and CSSI for
the raw data, the method which can estimate the displacement of
simple beam was developed. Also, the developed method can be
extended to calculate the strain and finally applicable to estimate a
stress distribution of a structural member. To verify the validity of the
method, the loading test on a simple beam was conducted and TLS
measured it. Through a comparison of the estimated stress and
reference stress, the validity of the method is confirmed.
Abstract: An Acoustic Micro-Energy Harvester (AMEH) is
developed to convert wasted acoustical energy into useful electrical
energy. AMEH is mathematically modeled using Lumped Element
Modelling (LEM) and Euler-Bernoulli beam (EBB) modelling. An
experiment is designed to validate the mathematical model and assess
the feasibility of AMEH. Comparison of theoretical and experimental
data on critical parameter value such as Mm, Cms, dm and Ceb showed
the variances are within 1% to 6%, which is reasonably acceptable.
Then, AMEH undergoes bandwidth tuning for performance
optimization. The AMEH successfully produces 0.9V/(m/s^2) and
1.79μW/(m^2/s^4) at 60Hz and 400kΩ resistive load which only
show variances about 7% compared to theoretical data. At 1g and
60Hz resonance frequency, the averaged power output is about
2.2mW which fulfilled a range of wireless sensors and
communication peripherals power requirements. Finally, the design
for AMEH is assessed, validated and deemed as a feasible design.
Abstract: This paper presents the ‘Eye Ball Motion Controlled
Wheelchair using IR Sensors’ for the elderly and differently abled
people. In this eye tracking based technology, three Proximity
Infrared (IR) sensor modules are mounted on an eye frame to trace
the movement of the iris. Since, IR sensors detect only white objects;
a unique sequence of digital bits is generated corresponding to each
eye movement. These signals are then processed via a micro
controller IC (PIC18F452) to control the motors of the wheelchair.
The potential and efficiency of previously developed rehabilitation
systems that use head motion, chin control, sip-n-puff control, voice
recognition, and EEG signals variedly have also been explored in
detail. They were found to be inconvenient as they served either
limited usability or non-affordability. After multiple regression
analyses, the proposed design was developed as a cost-effective,
flexible and stream-lined alternative for people who have trouble
adopting conventional assistive technologies.
Abstract: The Figaro AM-1 sensor module which employs TGS
2600 model gas sensor in air quality assessment was used. The
system was coupled with a microprocessor that enables sensor
module to create warning message via telephone. This low cot sensor
system’s performance was compared with a DiagNose II commercial
electronic nose system. Both air quality sensor and electronic nose
system employ metal oxide chemical gas sensors. In the study
experimental setup, data acquisition methods for electronic nose
system, and performance of the low cost air quality system were
evaluated and explained.
Abstract: Designing cost-efficient, secure network protocols for
Wireless Sensor Networks (WSNs) is a challenging problem because
sensors are resource-limited wireless devices. Security services such
as authentication and improved pairwise key establishment are
critical to high efficient networks with sensor nodes. For sensor
nodes to correspond securely with each other efficiently, usage of
cryptographic techniques is necessary. In this paper, two key
predistribution schemes that enable a mobile sink to establish a
secure data-communication link, on the fly, with any sensor nodes.
The intermediate nodes along the path to the sink are able to verify
the authenticity and integrity of the incoming packets using a
predicted value of the key generated by the sender’s essential power.
The proposed schemes are based on the pairwise key with the mobile
sink, our analytical results clearly show that our schemes perform
better in terms of network resilience to node capture than existing
schemes if used in wireless sensor networks with mobile sinks.
Abstract: Surf is an increasingly popular sport and its performance evaluation is often qualitative. This work aims at using a smartphone to collect and analyze the GPS and inertial sensors data in order to obtain quantitative metrics of the surfing performance. Two approaches are compared for detection of wave rides, computing the number of waves rode in a surfing session, the starting time of each wave and its duration. The first approach is based on computing the velocity from the Global Positioning System (GPS) signal and finding the velocity thresholds that allow identifying the start and end of each wave ride. The second approach adds information from the Inertial Measurement Unit (IMU) of the smartphone, to the velocity thresholds obtained from the GPS unit, to determine the start and end of each wave ride. The two methods were evaluated using GPS and IMU data from two surfing sessions and validated with similar metrics extracted from video data collected from the beach. The second method, combining GPS and IMU data, was found to be more accurate in determining the number of waves, start time and duration. This paper shows that it is feasible to use smartphones for quantification of performance metrics during surfing. In particular, detection of the waves rode and their duration can be accurately determined using the smartphone GPS and IMU.
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: Cooperative spectrum sensing is a crucial challenge in
cognitive radio networks. Cooperative sensing can increase the
reliability of spectrum hole detection, optimize sensing time and
reduce delay in cooperative networks. In this paper, an efficient
central capacity optimization algorithm is proposed to minimize
cooperative sensing time in a homogenous sensor network using OR
decision rule subject to the detection and false alarm probabilities
constraints. The evaluation results reveal significant improvement in
the sensing time and normalized capacity of the cognitive sensors.
Abstract: This paper presents the design and characterization of
analog readout interface circuits for ion sensitive field effect
transistor (ISFET) and ion selective electrode (ISE) based sensor.
These interface circuits are implemented using MIMOS’s 0.35um
CMOS technology and experimentally characterized under 24-leads
QFN package. The characterization evaluates the circuit’s
functionality, output sensitivity and output linearity. Commercial
sensors for both ISFET and ISE are employed together with glass
reference electrode during testing. The test result shows that the
designed interface circuits manage to readout signals produced by
both sensors with measured sensitivity of ISFET and ISE sensor are
54mV/pH and 62mV/decade, respectively. The characterized output
linearity for both circuits achieves above 0.999 Rsquare. The readout
also has demonstrated reliable operation by passing all qualifications
in reliability test plan.