Abstract: In this article, we deal with a variant of the classical
course timetabling problem that has a practical application in many
areas of education. In particular, in this paper we are interested in
high schools remedial courses. The purpose of such courses is to
provide under-prepared students with the skills necessary to succeed
in their studies. In particular, a student might be under prepared in
an entire course, or only in a part of it. The limited availability
of funds, as well as the limited amount of time and teachers at
disposal, often requires schools to choose which courses and/or which
teaching units to activate. Thus, schools need to model the training
offer and the related timetabling, with the goal of ensuring the
highest possible teaching quality, by meeting the above-mentioned
financial, time and resources constraints. Moreover, there are some
prerequisites between the teaching units that must be satisfied. We
first present a Mixed-Integer Programming (MIP) model to solve
this problem to optimality. However, the presence of many peculiar
constraints contributes inevitably in increasing the complexity of
the mathematical model. Thus, solving it through a general-purpose
solver may be performed for small instances only, while solving
real-life-sized instances of such model requires specific techniques
or heuristic approaches. For this purpose, we also propose a heuristic
approach, in which we make use of a fast constructive procedure
to obtain a feasible solution. To assess our exact and heuristic
approaches we perform extensive computational results on both
real-life instances (obtained from a high school in Lecce, Italy) and
randomly generated instances. Our tests show that the MIP model is
never solved to optimality, with an average optimality gap of 57%.
On the other hand, the heuristic algorithm is much faster (in about the
50% of the considered instances it converges in approximately half of
the time limit) and in many cases allows achieving an improvement
on the objective function value obtained by the MIP model. Such an
improvement ranges between 18% and 66%.
Abstract: The spindle system is one of the most important
components of machine tool. The dynamic properties of the spindle
affect the machining productivity and quality of the work pieces.
Thus, it is important and necessary to determine its dynamic
characteristics of spindles in the design and development in order to
avoid forced resonance. The finite element method (FEM) has been
adopted in order to obtain the dynamic behavior of spindle system.
For this reason, obtaining the Campbell diagrams and determining the
critical speeds are very useful to evaluate the spindle system
dynamics. The unbalance response of the system to the center of
mass unbalance at the cutting tool is also calculated to investigate the
dynamic behavior. In this paper, we used an ANSYS Parametric
Design Language (APDL) program which based on finite element
method has been implemented to make the full dynamic analysis and
evaluation of the results. Results show that the calculated critical
speeds are far from the operating speed range of the spindle, thus, the
spindle would not experience resonance, and the maximum
unbalance response at operating speed is still with acceptable limit.
ANSYS Parametric Design Language (APDL) can be used by spindle
designer as tools in order to increase the product quality, reducing
cost, and time consuming in the design and development stages.
Abstract: Biodiesel production from vegetable oil will produce
glycerol as by-product about 10% of the biodiesel production. The
amount of glycerol that was produced needed alternative way to
handling immediately so as to not become the waste that polluted
environment. One of the solutions was to process glycerol to
polyglycidyl nitrate (PGN). PGN is synthesized from glycerol by
three-step reactions i.e. nitration of glycerol, cyclization of 13-
dinitroglycerine and polymerization of glycosyl nitrate. Optimum
condition of nitration of glycerol with nitric acid has not been known.
Thermodynamic feasibility should be done before run experiments in
the laboratory. The aim of this study was to determine the parameters
those affect nitration of glycerol and nitric acid and chose the
operation condition. Many parameters were simulated to verify its
possibility to experiment under conditions which would get the
highest conversion of 1, 3-dinitroglycerine and which was the ideal
condition to get it. The parameters that need to be studied to obtain
the highest conversion of 1, 3-dinitroglycerine were mol ratio of
nitric acid/glycerol, reaction temperature, mol ratio of
glycerol/dichloromethane and pressure. The highest conversion was
obtained in the range of mol ratio of nitric acid /glycerol between 2/1
– 5/1, reaction temperature of 5-25oC and pressure of 1 atm. The
parameters that need to be studied further to obtain the highest
conversion of 1.3 DNG are mol ratio of nitric acid/glycerol and
reaction temperature.
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: Background in music analysis: Traditionally, when we
think about a composer’s sketches, the chances are that we are
thinking in terms of the working out of detail, rather than the
evolution of an overall concept. Since music is a “time art,” it follows
that questions of a form cannot be entirely detached from
considerations of time. One could say that composers tend to regard
time either as a place gradually and partially intuitively filled, or they
can look for a specific strategy to occupy it. It seems that the one
thing that sheds light on Stockhausen’s compositional thinking is his
frequent use of “form schemas,” that is often a single-page
representation of the entire structure of a piece.
Background in music technology: Sonic Visualiser is a program
used to study a musical recording. It is an open source application for
viewing, analyzing, and annotating music audio files. It contains a
number of visualisation tools, which are designed with useful default
parameters for musical analysis. Additionally, the Vamp plugin
format of SV supports to provide analysis such as for example
structural segmentation.
Aims: The aim of paper is to show how SV may be used to obtain
a better understanding of the specific musical work, and how the
compositional strategy does impact on musical structures and musical
surfaces. It is known that “traditional” music analytic methods don’t
allow indicating interrelationships between musical surface (which is
perceived) and underlying musical/acoustical structure.
Main Contribution: Stockhausen had dealt with the most diverse
musical problems by the most varied methods. A characteristic which
he had never ceased to be placed at the center of his thought and
works, it was the quest for a new balance founded upon an acute
connection between speculation and intuition. In the case with
Mikrophonie I (1964) for tam-tam and 6 players Stockhausen makes
a distinction between the “connection scheme,” which indicates the
ground rules underlying all versions, and the form scheme, which is
associated with a particular version. The preface to the published
score includes both the connection scheme, and a single instance of a
“form scheme,” which is what one can hear on the CD recording. In
the current study, the insight into the compositional strategy chosen
by Stockhausen was been compared with auditory image, that is, with
the perceived musical surface. Stockhausen’s musical work is
analyzed both in terms of melodic/voice and timbre evolution.
Implications: The current study shows how musical structures
have determined of musical surface. The general assumption is this,
that while listening to music we can extract basic kinds of musical
information from musical surfaces. It is shown that interactive
strategies of musical structure analysis can offer a very fruitful way
of looking directly into certain structural features of music.
Abstract: Supply chains are the backbone of trade and
commerce. Their logistics use different transport corridors on regular
basis for operational purpose. The international supply chain
transport corridors include different infrastructure elements (e.g.
weighbridge, package handling equipments, border clearance
authorities, and so on). This paper presents the use of multi-agent
systems (MAS) to model and simulate some aspects of transportation
corridors, and in particular the area of weighbridge resource
optimization for operational profit. An underlying multi-agent model
provides a means of modeling the relationships among stakeholders
in order to enable coordination in a transport corridor environment.
Simulations of the costs of container unloading, reloading, and
waiting time for queuing up tracks have been carried out using data
sets. Results of the simulation provide the potential guidance in
making decisions about optimal service resource allocation in a trade
corridor.
Abstract: To mitigate the urban heat island effect has become a
global issue when we are faced with the challenge of climate change.
Through literature review, plant photosynthesis can reduce the carbon
dioxide and mitigate the urban heat island effect to a degree. Because
there are not enough open space and parks, green roof has become an
important policy in Taiwan.
We selected elementary school buildings in northern New Taipei
City as research subjects since elementary schools are asked with
priority to build green roof and important educational place to promote
green roof concept. Testo175-H1 recording device was used to record
the temperature and humidity differences between roof surface and
interior space below roof with and without green roof in the long-term.
We also use questionnaires to investigate the awareness of comfort
level of green roof and sensation of teachers and students of the
elementary schools.
The results indicated that the temperature of roof without greening
was higher than that with greening by about 2°C. But sometimes
during noontime, the temperature of green roof was higher than that of
non-green roof probably because of the character of the accumulation
and dissipation of heat of greening. The temperature of the interior
space below green roof was normally lower than that without green
roof by about 1°C, showing that green roof could lower the
temperature. The humidity of the green roof was higher than the one
without greening also indicated that green roof retained water better.
Teachers liked to combine green roof concept in the curriculum,
and students wished all classes can take turns to maintain the green
roof. Teachers and students whose school had integrated green roof
concept in the curriculum were more willing to participate in the
maintenance work of green roof. Teachers and students who may have
access to and touch the green roof can be more aware of the green roof
benefit. We suggest architects to increase the accessibility and
visibility of green roof, such as use it as a part of the activity space.
This idea can be a reference to the green roof curriculum design.
Abstract: This article proposes a new method for application in
communication circuit systems that increase efficiency, PAE, output
power and gain in the circuit. The proposed method is based on a
combination of switching class-E and class-J and has been termed
class-EJ. This method was investigated using both theory and
simulation to confirm ∼72% PAE and output power of >39dBm. The
combination and design of the proposed power amplifier accrues gain
of over 15dB in the 2.9 to 3.5GHz frequency bandwidth. This circuit
was designed using MOSFET and high power transistors. The loadand
source-pull method achieved the best input and output networks
using lumped elements. The proposed technique was investigated for
fundamental and second harmonics having desirable amplitudes for
the output signal.
Abstract: Mammography is widely used technique for breast cancer
screening. There are various other techniques for breast cancer screening
but mammography is the most reliable and effective technique. The
images obtained through mammography are of low contrast which
causes problem for the radiologists to interpret. Hence, a high quality
image is mandatory for the processing of the image for extracting any
kind of information from it. Many contrast enhancement algorithms have
been developed over the years. In the present work, an efficient
morphology based technique is proposed for contrast enhancement of
masses in mammographic images. The proposed method is based on
Multiscale Morphology and it takes into consideration the scale of the
structuring element. The proposed method is compared with other stateof-
the-art techniques. The experimental results show that the proposed
method is better both qualitatively and quantitatively than the other
standard contrast enhancement techniques.
Abstract: This paper describes an optimization tool-based
design strategy for a Current Mode Logic CML divide-by-2 circuit.
Representing a building block for output frequency generation in a
RFID protocol based-frequency synthesizer, the circuit was designed
to minimize the power consumption for driving of multiple loads
with unbalancing (at transceiver level). Implemented with XFAB
XC08 180 nm technology, the circuit was optimized through
MunEDA WiCkeD tool at Cadence Virtuoso Analog Design
Environment ADE.
Abstract: Family is a basic unit of the society and the main
source of human development. The initial aim of the family is
psychological and social support of its members and has special
developmental stages. Researches show the families who have less
cohesion, have more conflicts and maladjustments and the members
of such families are not able to communicate effectively. Family is a
system in which any inter communication is related to child rearing
patterns and can affect it. Even the child rearing styles in childhood
can determine the family communications in adulthood. Therefore,
the aim of the present research was to examine the relationship
between child-rearing styles including authoritative, authoritarian and
permissive with dimensions of family communication patterns
including the conversation and conformity. The research design was a
correlational and the population consisted of the psychology students
of Roudehen Islamic Azad University who were studying in
academic year 2013-2014. A sample of 324 students was selected
randomly from the population. The research tools were the Baumrind
Child-rearing Questionnaires and Family Communication
Patterns Inventory, The Revised Scale of Koerner and Fitzpatrick.
The result was as below: (a) there was a positive and significant
relationship between conversation orientation and authoritative style.
(b) There was no significant relationship between conversation
orientation and other child-rearing styles. (c) There was a negative
significant relationship between conformity orientation and
authoritative style. (d) There was a positive significant relationship
between conformity orientation with authoritarian and permissive
styles. (e) There was a significant relationship between 3 dimensions
of child-rearing and communication patterns.
Abstract: Advanced treatments such as forward osmosis (FO)
can be used to separate or reject nutrients from secondary treated
effluents. Forward osmosis uses the chemical potential across the
membrane, which is the osmotic pressure gradient, to induce water to
flow through the membrane from a feed solution (FS) into a draw
solution (DS). The performance of FO is affected by the membrane
characteristics, composition of the FS and DS, and operating
conditions. The aim of this study was to investigate the optimum
velocity and temperature for nutrient rejection and water flux
performance in FO treatments. MgCl2 was used as the DS in the FO
process. The results showed that higher cross flow velocities yielded
higher water fluxes. High rejection of nutrients was achieved by using
a moderate cross flow velocity at 0.25 m/s. Nutrient rejection was
insensitive to temperature variation, whereas water flux was
significantly impacted by it. A temperature of 25°C was found to be
good for nutrient rejection.
Abstract: Here, we study the characteristic feature of
conventional (ON-OFF keying) and soliton based transmission
system. We consider 20Gbps transmission system implemented with
Conventional Single Mode Fiber (C-SMF) to examine the role of
Gaussian pulse which is the characteristic of conventional
propagation and Hyperbolic-secant pulse which is the characteristic
of soliton propagation in it. We note the influence of these pulses
with respect to different dispersion lengths and soliton period in
conventional and soliton system respectively and evaluate the system
performance in terms of Quality factor. From the analysis, we could
prove that the soliton pulse has the consistent performance even for
long distance without dispersion compensation than the conventional
system as it is robust to dispersion. For the length of transmission of
200Km, soliton system yielded Q of 33.958 while the conventional
system totally exhausted with Q=0.
Abstract: To understand the friction stir welding process, it is
very important to know the nature of the material flow in and around
the tool. The process is a combination of both thermal as well as
mechanical work i.e. it is a coupled thermo-mechanical process.
Numerical simulations are very much essential in order to obtain a
complete knowledge of the process as well as the physics underlying
it. In the present work a model based approach is adopted in order to
study material flow. A thermo-mechanical based CFD model is
developed using a Finite Element package, Comsol Multiphysics.
The fluid flow analysis is done. The model simultaneously predicts
shear strain fields, shear strain rates and shear stress over the entire
workpiece for the given conditions. The flow fields generated by the
streamline plot give an idea of the material flow. The variation of
dynamic viscosity, velocity field and shear strain fields with various
welding parameters is studied. Finally the result obtained from the
above mentioned conditions is discussed elaborately and concluded.
Abstract: The polymer foil used for manufacturing of
laminated glass members behaves in a viscoelastic manner with
temperature dependance. This contribution aims at incorporating
the time/temperature-dependent behavior of interlayer to our earlier
elastic finite element model for laminated glass beams. The model
is based on a refined beam theory: each layer behaves according
to the finite-strain shear deformable formulation by Reissner and
the adjacent layers are connected via the Lagrange multipliers
ensuring the inter-layer compatibility of a laminated unit. The
time/temperature-dependent behavior of the interlayer is accounted
for by the generalized Maxwell model and by the time-temperature
superposition principle due to the Williams, Landel, and Ferry.
The resulting system is solved by the Newton method with
consistent linearization and the viscoelastic response is determined
incrementally by the exponential algorithm. By comparing the model
predictions against available experimental data, we demonstrate that
the proposed formulation is reliable and accurately reproduces the
behavior of the laminated glass units.
Abstract: Microscopic simulation tool kits allow for
consideration of the two processes of railway operations and the
previous timetable production. Block occupation conflicts on both
process levels are often solved by using defined train priorities. These
conflict resolutions (dispatching decisions) generate reactionary
delays to the involved trains. The sum of reactionary delays is
commonly used to evaluate the quality of railway operations, which
describes the timetable robustness. It is either compared to an
acceptable train performance or the delays are appraised
economically by linear monetary functions. It is impossible to
adequately evaluate dispatching decisions without a well-founded
objective function. This paper presents a new approach for the
evaluation of dispatching decisions. The approach uses mode choice
models and considers the behaviour of the end-customers. These
models evaluate the reactionary delays in more detail and consider
other competing modes of transport. The new approach pursues the
coupling of a microscopic model of railway operations with the
macroscopic choice mode model. At first, it will be implemented for
railway operations process but it can also be used for timetable
production. The evaluation considers the possibility for the customer
to interchange to other transport modes. The new approach starts to
look at rail and road, but it can also be extended to air travel. The
result of mode choice models is the modal split. The reactions by the
end-customers have an impact on the revenue of the train operating
companies. Different purposes of travel have different payment
reserves and tolerances towards late running. Aside from changes to
revenues, longer journey times can also generate additional costs.
The costs are either time- or track-specific and arise from required
changes to rolling stock or train crew cycles. Only the variable values
are summarised in the contribution margin, which is the base for the
monetary evaluation of delays. The contribution margin is calculated
for different possible solutions to the same conflict. The conflict
resolution is optimised until the monetary loss becomes minimal. The
iterative process therefore determines an optimum conflict resolution
by monitoring the change to the contribution margin. Furthermore, a
monetary value of each dispatching decision can also be derived.
Abstract: The strawberry tree (Arbutus unedo L.) is a small tree
or shrub from botanical Ericaceae family that grows spontaneously
nearby the Mediterranean basin and produce edible red fruits. A
traditional processed fruit application, in Mediterranean countries, is
the production of a spirit (known as aguardente de medronho, in
Portugal) obtained from the fermented fruit. The main objective of
our study was to contribute to the knowledge about the influence of
the degree of maturation of fruits in the volatile composition and
quality of arbutus spirit. The major volatiles in the three distillates
fractions (head, heart and tail) obtained from fermentation of two
different fruit maturation levels were quantified by GC-FID analysis
and ANOVA one-way was performed. Additionally, the total
antioxidant capacity and total phenolic compounds of both arbutus
fruit spirits were determined, by ABTS and Folin-Ciocalteau method,
respectively. The methanol concentration is higher (1022.39 g/hL
a.a.) in the spirit made from fruits with highest total soluble solids,
which is a value above the legal limit (1000 g/hL a.a.). Overall, our
study emphasizes, for the first time, the influence of maturation
degree of arbutus fruits in the spirit volatile composition and quality.
Abstract: This work sets out to debate the tensions involved in
the processes of contamination and self-purification in the urban
space, particularly in the streams that run through the Buenos Aires
metropolitan area. For much of their course, those streams are piped;
their waters do not come into contact with the outdoors until they
have reached deeply impoverished urban areas with high levels of
environmental contamination. These are peripheral zones that, until
thirty years ago, were marshlands and fields. They are now densely
populated areas largely lacking in urban infrastructure.
The Cárcova neighborhood, where this project is underway, is in
the José León Suárez section of General San Martín county, Buenos
Aires province. A stretch of José León Suarez canal crosses the
neighborhood. Starting upstream, this canal carries pollutants due to
the sewage and industrial waste released into it. Further downstream,
in the neighborhood, domestic drainage is poured into the stream. In
this paper, we formulate a hypothesis diametrical to the one that
holds that these neighborhoods are the primary source of
contamination, suggesting instead that in the stretch of the canal that
runs through the neighborhood the stream’s waters are actually
cleaned and the sediments accumulate pollutants. Indeed, the
stretches of water that runs through these neighborhoods act as water
processing plants for the metropolis.
This project has studied the different organic-load polluting
contributions to the water in a certain stretch of the canal, the
reduction of that load over the course of the canal, and the
incorporation of pollutants into the sediments. We have found that
the surface water has considerable ability to self-purify, mostly due to
processes of sedimentation and adsorption. The polluting load is
accumulated in the sediments where that load stabilizes slowly by
means of anaerobic processes. In this study, we also investigated the
risks of sediment management and the use of the processes studied
here in controlled conditions as tools of environmental restoration.
Abstract: Present study is carried out on six lane divided urban
arterial road in Patna and Pune city of India. Both the road having
distinct differences in terms of the vehicle composition and the road
side parking. Arterial road in Patan city has 33% of non-motorized
mode, whereas Pune arterial road dominated by 65% of Two wheeler.
Also road side parking is observed in Patna city. The field studies
using videography techniques are carried out for traffic data
collection. Data are extracted for one minute duration for vehicle
composition, speed variation and flow rate on selected arterial road of
the two cities. Speed flow relationship is developed and capacity is
determine. Equivalency factor in terms of dynamic car unit is
determine to represent the vehicle is single unit. The variation in the
capacity due to side friction, presence of non motorized traffic and
effective utilization of lane width is compared at concluding remarks.
Abstract: Transmission shafts are affected by various forces, for
example, during acceleration or sudden breaks, bending during
transportation, vertical forces that lead to cuts. One of the main
failures in combines is breaking shaft which repairmen refer it.
Structural resistance of canal against torque is very important in the
beginning of the movement. For analyzing stress, a typical sample
from a type of combine was selected, called JD955 combine. Long
shaft in this combine was analyzed with finite element method by
Ansys13 generic package under static load. Conducted analysis
showed that there is a maximum stress in contact surfaces of
indentations and also in place of changing diameter. Safety factor
value is low in parts of the shaft and this increases the probability of
failure at these points. To improve the conditions with the least cost
and an approach of product improvement, using alternative alloy is
important.