Abstract: With 40% of total world energy consumption,
building systems are developing into technically complex large
energy consumers suitable for application of sophisticated power
management approaches to largely increase the energy efficiency
and even make them active energy market participants. Centralized
control system of building heating and cooling managed by
economically-optimal model predictive control shows promising
results with estimated 30% of energy efficiency increase. The research
is focused on implementation of such a method on a case study
performed on two floors of our faculty building with corresponding
sensors wireless data acquisition, remote heating/cooling units and
central climate controller. Building walls are mathematically modeled
with corresponding material types, surface shapes and sizes. Models
are then exploited to predict thermal characteristics and changes in
different building zones. Exterior influences such as environmental
conditions and weather forecast, people behavior and comfort
demands are all taken into account for deriving price-optimal climate
control. Finally, a DC microgrid with photovoltaics, wind turbine,
supercapacitor, batteries and fuel cell stacks is added to make the
building a unit capable of active participation in a price-varying
energy market. Computational burden of applying model predictive
control on such a complex system is relaxed through a hierarchical
decomposition of the microgrid and climate control, where the
former is designed as higher hierarchical level with pre-calculated
price-optimal power flows control, and latter is designed as lower
level control responsible to ensure thermal comfort and exploit
the optimal supply conditions enabled by microgrid energy flows
management. Such an approach is expected to enable the inclusion
of more complex building subsystems into consideration in order to
further increase the energy efficiency.
Abstract: This paper describes a simple way to control the speed
of PMBLDC motor using Fuzzy logic control method. In the
conventional PI controller the performance of the motor system is
simulated and the speed is regulated by using PI controller. These
methods used to improve the performance of PMSM drives, but in
some cases at different operating conditions when the dynamics of
the system also vary over time and it can change the reference speed,
parameter variations and the load disturbance. The simulation is
powered with the MATLAB program to get a reliable and flexible
simulation. In order to highlight the effectiveness of the speed control
method the FLC method is used. The proposed method targeted in
achieving the improved dynamic performance and avoids the
variations of the motor drive. This drive has high accuracy, robust
operation from near zero to high speed. The effectiveness and
flexibility of the individual techniques of the speed control method
will be thoroughly discussed for merits and demerits and finally
verified through simulation and experimental results for comparative
analysis.
Abstract: In this study, the potential benefits of playing action
video game among congenitally deaf and dumb subjects is reported in
terms of EEG ratio indices. The frontal and occipital lobes are
associated with development of motor skills, cognition, and visual
information processing and color recognition. The sixteen hours of
First-Person shooter action video game play resulted in the increase
of the ratios β/(α+θ) and β/θ in frontal and occipital lobes. This can
be attributed to the enhancement of certain aspect of cognition among
deaf and dumb subjects.
Abstract: An analysis of the air tightness level is performed on a representative sample of school classrooms in Southern Spain, which allows knowing the infiltration level of these classrooms, mainly through its envelope, which can affect both energy demand and occupant's thermal comfort. By using a pressurization/depressurization equipment (Blower-Door test), a characterization of 45 multipurpose classrooms have been performed in nine non-university educational institutions of the main climate zones of Southern Spain. In spite of having two doors and a high ratio between glass surface and outer surface, it is possible to see in these classrooms that there is an adequate level of airtightness, since all the n50 values obtained are lower than 9.0 ACH, with an average value around 7.0 ACH.
Abstract: The application of recycle waste tires into civil
engineering practices, namely asphalt paving mixtures and cementbased
materials has been gaining ground across the world. This
review summarizes and compares the recent achievements in the area
of plain rubberized concrete (PRC), in details. Different treatment
methods have been discussed to improve the performance of
rubberized Portland cement concrete. The review also includes the
effects of size and amount of tire rubbers on mechanical and
durability properties of PRC. The microstructure behaviour of the
rubberized concrete was detailed.
Abstract: For several hundred years, the design of railway tracks
has practically remained unchanged. Traditionally, rail tracks are
placed on a ballast layer due to several reasons, including economy,
rapid drainage, and high load bearing capacity. The primary function
of ballast is to distributing dynamic track loads to sub-ballast and
subgrade layers, while also providing lateral resistance and allowing
for rapid drainage. Upon repeated trainloads, the ballast becomes
fouled due to ballast degradation and the intrusion of fines which
adversely affects the strength and deformation behaviour of ballast.
This paper presents the use of three-dimensional discrete element
method (DEM) in studying the shear behaviour of the fouled ballast
subjected to direct shear loading. Irregularly shaped particles of
ballast were modelled by grouping many spherical balls together in
appropriate sizes to simulate representative ballast aggregates. Fouled
ballast was modelled by injecting a specified number of miniature
spherical particles into the void spaces. The DEM simulation
highlights that the peak shear stress of the ballast assembly decreases
and the dilation of fouled ballast increases with an increase level of
fouling. Additionally, the distributions of contact force chain and
particle displacement vectors were captured during shearing progress,
explaining the formation of shear band and the evolutions of
volumetric change of fouled ballast.
Abstract: Microstructure and mechanical properties of AZ91D
Mg alloys for nonflammable use, containing Ca and Y, were
investigated in this study. Solid solution treatment of AZ91D Mg alloy
with Ca and Y was successfully conducted at 420oC and
supersaturated microstructure with almost all beta phases resolved into
matrix was obtained. After solid solution treatment, the alloy was
annealed at temperatures of 180 and 200oC for time intervals from 1
min to 48 hrs and hardness of each condition was measured by
micro-Vickers method. Peak aging conditions were deduced from the
results as at the temperature of 200oC for 10 hrs. Hot rolling was also
carried out at 400oC by the reduction ratio of 0.6 through 5 passes
followed by recrystallization treatment. Tensile and compressive
properties were measured at room temperature on the specimens of
each process, i.e. as-cast, solution treatment, hot rolling, and
recrystallization.
Abstract: The aim of irrigation is to recharge the available water
in the soil. Quality of irrigation water is essential for the yield and
quality of crops produced, maintenance of soil productivity and
protection of the environment. The analysis of irrigation water arises
as a need to know the impact of irrigation water on the yield of crops,
the effect, and the necessary control measures to rectify the effect of
this for optimum production and yield of crops. This study was conducted to assess the quality of irrigation water
with its performance on crop planted, in Josepdam irrigation scheme
Bacita, Nigeria. Field visits were undertaken to identify and locate
water supply sources and collect water samples from these sources;
X1 Drain, Oshin, River Niger loop and Ndafa. Laboratory
experiments were then undertaken to determine the quality of raw
water from these sources. The analysis was carried for various parameters namely; physical
and chemical analyses after water samples have been taken from four
sources. The samples were tested in laboratory. Results showed that
the raw water sources shows no salinity tendencies with SAR values
less than 1me/l and Ecvaules at Zero while the pH were within the
recommended range by FAO, there are increase in potassium and
sulphate content contamination in three of the location. From this, it
is recommended that there should be proper monitoring of the
scheme by conducting analysis of water and soil in the environment,
preferable test should be carried out at least one year to cover the
impact of seasonal variations and to determine the physical and
chemical analysis of the water used for irrigation at the scheme.
Abstract: Many cluster based routing protocols have been
proposed in the field of wireless sensor networks, in which a group of
nodes are formed as clusters. A cluster head is selected from one
among those nodes based on residual energy, coverage area, number
of hops and that cluster-head will perform data gathering from
various sensor nodes and forwards aggregated data to the base station
or to a relay node (another cluster-head), which will forward the
packet along with its own data packet to the base station. Here a
Game Theory based Diligent Energy Utilization Algorithm (GTDEA)
for routing is proposed. In GTDEA, the cluster head selection is done
with the help of game theory, a decision making process, that selects
a cluster-head based on three parameters such as residual energy
(RE), Received Signal Strength Index (RSSI) and Packet Reception
Rate (PRR). Finding a feasible path to the destination with minimum
utilization of available energy improves the network lifetime and is
achieved by the proposed approach. In GTDEA, the packets are
forwarded to the base station using inter-cluster routing technique,
which will further forward it to the base station. Simulation results
reveal that GTDEA improves the network performance in terms of
throughput, lifetime, and power consumption.
Abstract: Although Mobile Wireless Sensor Networks (MWSNs),
which consist of mobile sensor nodes (MSNs), can cover a wide range
of observation region by using a small number of sensor nodes, they
need to construct a network to collect the sensing data on the base
station by moving the MSNs. As an effective method, the network
construction method based on Virtual Rails (VRs), which is referred
to as VR method, has been proposed. In this paper, we propose two
types of effective techniques for the VR method. They can prolong
the operation time of the network, which is limited by the battery
capabilities of MSNs and the energy consumption of MSNs. The
first technique, an effective arrangement of VRs, almost equalizes
the number of MSNs belonging to each VR. The second technique,
an adaptive movement method of MSNs, takes into account the
residual energy of battery. In the simulation, we demonstrate that each
technique can improve the network lifetime and the combination of
both techniques is the most effective.
Abstract: This paper describes an ab-initio design, development and calibration results of an Optical Sensor Ground Reaction Force Measurement Platform (OSGRFP) for gait and geriatric studies. The developed system employs an array of FBG sensors to measure the respective ground reaction forces from all three axes (X, Y and Z), which are perpendicular to each other. The novelty of this work is two folded. One is in its uniqueness to resolve the tri axial resultant forces during the stance in to the respective pure axis loads and the other is the applicability of inherently advantageous FBG sensors which are most suitable for biomechanical instrumentation. To validate the response of the FBG sensors installed in OSGRFP and to measure the cross sensitivity of the force applied in other directions, load sensors with indicators are used. Further in this work, relevant mathematical formulations are presented for extracting respective ground reaction forces from wavelength shifts/strain of FBG sensors on the OSGRFP. The result of this device has implications in understanding the foot function, identifying issues in gait cycle and measuring discrepancies between left and right foot. The device also provides a method to quantify and compare relative postural stability of different subjects under test, which has implications in post-surgical rehabilitation, geriatrics and optimizing training protocols for sports personnel.
Abstract: With the strengthened regulation on the mandatory use
of recycled aggregate, development of construction materials using
recycled aggregate has recently increased. This study aimed to secure
the performance of asphalt concrete mixture by developing
recycled-modified asphalt using recycled basalt aggregate from the
Jeju area. The strength of the basalt aggregate from the Jeju area used
in this study was similar to that of general aggregate, while the specific
surface area was larger due to the development of pores. Modified
asphalt was developed using a general aggregate-recycled aggregate
ratio of 7:3, and the results indicated that the Marshall stability
increased by 27% compared to that of asphalt concrete mixture using
only general aggregate, and the flow values showed similar levels.
Also, the indirect tensile strength increased by 79%, and the toughness
increased by more than 100%. In addition, the TSR for examining
moisture resistance was 0.95 indicating that the reduction in the
indirect tensile strength due to moisture was very low (5% level), and
the developed recycled-modified asphalt could satisfy all the quality
standards of asphalt concrete mixture.
Abstract: Energy consumption data, in particular those involving
public buildings, are impacted by many factors: the building structure,
climate/environmental parameters, construction, system operating
condition, and user behavior patterns. Traditional methods for data
analysis are insufficient. This paper delves into the data mining
technology to determine its application in the analysis of building
energy consumption data including energy consumption prediction,
fault diagnosis, and optimal operation. Recent literature are reviewed
and summarized, the problems faced by data mining technology in the
area of energy consumption data analysis are enumerated, and research
points for future studies are given.
Abstract: Model updating is an inverse eigenvalue problem which
concerns the modification of an existing but inaccurate model with
measured modal data. In this paper, an efficient gradient based
iterative method for updating the mass, damping and stiffness
matrices simultaneously using a few of complex measured modal
data is developed. Convergence analysis indicates that the iterative
solutions always converge to the unique minimum Frobenius norm
symmetric solution of the model updating problem by choosing a
special kind of initial matrices.
Abstract: This paper proposes a method of learning topics for
broadcasting contents. There are two kinds of texts related to
broadcasting contents. One is a broadcasting script, which is a series of
texts including directions and dialogues. The other is blogposts, which
possesses relatively abstracted contents, stories, and diverse
information of broadcasting contents. Although two texts range over
similar broadcasting contents, words in blogposts and broadcasting
script are different. When unseen words appear, it needs a method to
reflect to existing topic. In this paper, we introduce a semantic
vocabulary expansion method to reflect unseen words. We expand
topics of the broadcasting script by incorporating the words in
blogposts. Each word in blogposts is added to the most semantically
correlated topics. We use word2vec to get the semantic correlation
between words in blogposts and topics of scripts. The vocabularies of
topics are updated and then posterior inference is performed to
rearrange the topics. In experiments, we verified that the proposed
method can discover more salient topics for broadcasting contents.
Abstract: Some of the main causes for degradation of polymeric materials are thermal aging, hydrolysis, oxidation or chemical degradation by acids, alkalis or water. The first part of this paper provides a brief summary of advances in technology, methods and specification of composite materials for relining as a rehabilitation technique for sewage systems. The second part summarizes an investigation on frequently used composite materials for relining in Sweden, the rubber filled epoxy composite and reinforced polyester composite when they were immersed in deionized water or in dry conditions, and elevated temperatures up to 80°C in the laboratory. The tests were conducted by visual inspection, microscopy, Dynamic Mechanical Analysis (DMA), Differential Scanning Calorimetry (DSC) as well as mechanical testing, three point bending and tensile testing.
Abstract: This paper outlines the development of an
experimental technique in quantifying supersonic jet flows, in an
attempt to avoid seeding particle problems frequently associated with
particle-image velocimetry (PIV) techniques at high Mach numbers.
Based on optical flow algorithms, the idea behind the technique
involves using high speed cameras to capture Schlieren images of the
supersonic jet shear layers, before they are subjected to an adapted
optical flow algorithm based on the Horn-Schnuck method to
determine the associated flow fields. The proposed method is capable
of offering full-field unsteady flow information with potentially
higher accuracy and resolution than existing point-measurements or
PIV techniques. Preliminary study via numerical simulations of a
circular de Laval jet nozzle successfully reveals flow and shock
structures typically associated with supersonic jet flows, which serve
as useful data for subsequent validation of the optical flow based
experimental results. For experimental technique, a Z-type Schlieren
setup is proposed with supersonic jet operated in cold mode,
stagnation pressure of 4 bar and exit Mach of 1.5. High-speed singleframe
or double-frame cameras are used to capture successive
Schlieren images. As implementation of optical flow technique to
supersonic flows remains rare, the current focus revolves around
methodology validation through synthetic images. The results of
validation test offers valuable insight into how the optical flow
algorithm can be further improved to improve robustness and
accuracy. Despite these challenges however, this supersonic flow
measurement technique may potentially offer a simpler way to
identify and quantify the fine spatial structures within the shock shear
layer.
Abstract: The present study investigates the effectiveness of
newly designed clayey pellets (fired clay pellets diameter sizes of 5
and 8 mm, and unfired clay pellets with the diameter size of 15 mm)
as the beds in the column adsorption process. The adsorption
experiments in the batch mode were performed before the column
experiment with the purpose to determine the order of adsorbent
package in the column which was to be designed in the investigation.
The column experiment was performed by using a known mass of the
clayey beds and the volume of the waste printing developer, which
was purified. The column was filled in the following order: fired clay
pellets of the diameter size of 5 mm, fired clay pellets of the diameter
size of 8 mm, and unfired clay pellets of the diameter size of 15 mm.
The selected order of the adsorbents showed a high removal
efficiency for zinc (97.8%) and copper (81.5%) ions. These
efficiencies were better than those in the case of the already existing
mode adsorption. The obtained experimental data present a good
basis for the selection of an appropriate column fill, but further
testing is necessary in order to obtain more accurate results.
Abstract: Purpose: The key aim of the research was to identify
the secondary stressors experienced by businesses affected by single
or repeated flooding and to determine to what extent businesses were
affected by these stressors, along with any resulting impact on health.
Additionally the research aimed to establish the likelihood of
businesses being re-exposed to the secondary stressors through
assessing awareness of flood risk, implementation of property
protection measures and level of community resilience. Design/methodology/approach: The chosen research method
involved the distribution of a questionnaire survey to businesses
affected by either single or repeated flood events. The questionnaire
included the Impact of Event Scale (a 15-item self-report measure
which assesses subjective distress caused by traumatic events). Findings: 55 completed questionnaires were returned by flood
impacted businesses. 89% of the businesses had sustained internal
flooding, while 11% had experienced external flooding. The results
established that the key secondary stressors experienced by
businesses, in order of priority, were: flood damage, fear of
reoccurring flooding, prevention of access to the premise/closure,
loss of income, repair works, length of closure and insurance issues.
There was a lack of preparedness for potential future floods and
consequent vulnerability to the emergence of secondary stressors
among flood affected businesses, as flood resistance or flood
resilience measures had only been implemented by 11% and 13%
respectively. In relation to the psychological repercussions, the
Impact of Event scores suggested that potential prevalence of posttraumatic
stress disorder (PTSD) was noted among 8 out of 55
respondents (l5%). Originality/value: The results improve understanding of the
enduring repercussions of flood events on businesses, indicating that
not only residents may be susceptible to the detrimental health
impacts of flood events and single flood events may be just as likely
as reoccurring flooding to contribute to ongoing stress. Lack of
financial resources is a possible explanation for the lack of
implementation of property protection measures among businesses,
despite 49% experiencing flooding on multiple occasions. Therefore
it is recommended that policymakers should consider potential
sources of financial support or grants towards flood defences for
flood impacted businesses. Any form of assistance should be made
available to businesses at the earliest opportunity as there was no
significant association between the time of the last flood event and
the likelihood of experiencing PTSD symptoms.
Abstract: Myoelectric control system is the fundamental
component of modern prostheses, which uses the myoelectric signals
from an individual’s muscles to control the prosthesis movements.
The surface electromyogram signal (sEMG) being noninvasive has
been used as an input to prostheses controllers for many years.
Recent technological advances has led to the development of
implantable myoelectric sensors which enable the internal
myoelectric signal (MES) to be used as input to these prostheses
controllers. The intramuscular measurement can provide focal
recordings from deep muscles of the forearm and independent signals
relatively free of crosstalk thus allowing for more independent
control sites. However, little work has been done to compare the two
inputs. In this paper we have compared the classification accuracy of
six pattern recognition based myoelectric controllers which use
surface myoelectric signals recorded using untargeted (symmetric)
surface electrode arrays to the same controllers with multichannel
intramuscular myolectric signals from targeted intramuscular
electrodes as inputs. There was no significant enhancement in the
classification accuracy as a result of using the intramuscular EMG
measurement technique when compared to the results acquired using
the surface EMG measurement technique. Impressive classification
accuracy (99%) could be achieved by optimally selecting only five
channels of surface EMG.