Abstract: The roll center is one of the key parameters for designing a suspension. Several driving characteristics are affected significantly by the migration of the roll center during the suspension-s motion. The strut/SLA (strut/short-long-arm) suspension, which is widely used in production cars, combines the space-saving characteristics of a MacPherson strut suspension with some of the preferred handling characteristics of an SLA suspension. In this study, a front strut/SLA suspension is modeled by ADAMS/Car software. Kinematic roll analysis is then employed to investigate how the rolling characteristics change under the wheel travel and steering input. The related parameters, including the roll center height, roll camber gain, toe change, scrub radius and wheel track width change, are analyzed and discussed. It is found that the strut/SLA suspension clearly has a higher roll center than strut and SLA suspensions do. The variations in the roll center height under roll analysis are very different as the wheel travel displacement and steering angle are added. The results of the roll camber gain, scrub radius and wheel track width change are considered satisfactory. However, the toe change is too large and needs fine-tuning through a sensitivity analysis.
Abstract: This paper presents an authoring tool which makes a
user easily and intuitively design vibrotactile sensation. A mobile
hardware platform powered by ANDROID, a multi-purpose haptic
driver and a linear resonance actuator are used to implement the
system of the presented authoring tool. The tool allows users to easily
and simply create a vibrotactile sensation by drawing vibrotactile
images and to feel the sensation by rubbing drawn images on the touch
screen of a mobile device. The tool supports a graphical interface for
designing, editing and playing vibrotactile images as well as a
pre-defined file format for save and open.
Abstract: Classification of electroencephalogram (EEG) signals
extracted during mental tasks is a technique that is actively pursued
for Brain Computer Interfaces (BCI) designs. In this paper, we
compared the classification performances of univariateautoregressive
(AR) and multivariate autoregressive (MAR) models
for representing EEG signals that were extracted during different
mental tasks. Multilayer Perceptron (MLP) neural network (NN)
trained by the backpropagation (BP) algorithm was used to classify
these features into the different categories representing the mental
tasks. Classification performances were also compared across
different mental task combinations and 2 sets of hidden units (HU): 2
to 10 HU in steps of 2 and 20 to 100 HU in steps of 20. Five different
mental tasks from 4 subjects were used in the experimental study and
combinations of 2 different mental tasks were studied for each
subject. Three different feature extraction methods with 6th order
were used to extract features from these EEG signals: AR
coefficients computed with Burg-s algorithm (ARBG), AR
coefficients computed with stepwise least square algorithm (ARLS)
and MAR coefficients computed with stepwise least square
algorithm. The best results were obtained with 20 to 100 HU using
ARBG. It is concluded that i) it is important to choose the suitable
mental tasks for different individuals for a successful BCI design, ii)
higher HU are more suitable and iii) ARBG is the most suitable
feature extraction method.
Abstract: Manufacturing companies are facing a broad variety
of challenges caused by a dynamic production environment. To
succeed in such an environment, it is crucial to minimize the loss of
time required to trigger the adaptation process of a company-s
production structures. This paper presents an approach for the
continuous monitoring of production structures by neurologic
principles. It enhances classical monitoring concepts, which are
principally focused on reactive strategies, and enables companies to
act proactively. Thereby, strategic aspects regarding the
harmonization of certain life cycles are integrated into the decision
making process for triggering the reconfiguration process of the
production structure.
Abstract: Internet application in China has maintained a constant
development tendency in the past decade. China is now one of the
most populous countries in terms of internet user population. While
offering enormous opportunities, the dramatic digitalization also
brings about a series of challenges that demand urgent attention.
Digital divide is one of the challenges that affect China as well as other
countries in the world. This paper examines digital divide in the
Chinese context from the perspective of development communication.
Through a case study of a rural township under the backdrop of the
rapid internet development in China, the paper discusses the
economic, psychological and cultural roots of digital divide; and
explores development communication strategies addressing the roots
of digital divide. It is argued that development communication must be
responsive to the potentialities and preferences of the specific society
and serve the purposes of participation and sustainability.
Abstract: This paper presents results of measurements campaign
carried out at a carrier frequency of 24GHz with the help of TPLINK
router in indoor line-of-sight (LOS) scenarios. Firstly, the
radio wave propagation strategies are analyzed in some rooms with
router of point to point Ad hoc network. Then floor attenuation is
defined for 3 floors in experimental region. The free space model and
dual slope models are modified by considering the influence of
corridor conditions on each floor. Using these models, indoor signal
attenuation can be estimated in modeling of indoor radio wave
propagation. These results and modified models can also be used in
planning the networks of future personal communications services.
Abstract: Organic farmers across Saskatchewan face soil
phosphorus (P) shortages. Due to the restriction on inputs in organic
systems, farmers rely on crop rotation and naturally-occurring
arbuscular mycorrhizal fungi (AMF) for plant P supply. Crop rotation
is important for disease, pest, and weed management. Crops that are
not colonized by AMF (non-mycorrhizal) can decrease colonization
of a following crop. An experiment was performed to quantify soil P
cycling in four cropping sequences under organic management and
determine if mustard (non-mycorrhizal) was delaying the
colonization of subsequent wheat. Soils from the four cropping
sequences were measured for inorganic soil P (Pi), AMF spore
density (SD), phospholipid fatty acid analysis (PLFA, for AMF
biomarker counts), and alkaline phosphatase activity (ALPase,
related to AMF metabolic activity). Plants were measured for AMF
colonization and P content and uptake of above-ground biomass. A
lack of difference in AMF activity indicated that mustard was not
depressing colonization. Instead, AMF colonization was largely
determined by crop type and crop rotation.
Abstract: Due to rapid economic growth, Indonesia's energy needs is rapidly increasing. Indonesia-s primary energy consumption has doubled in 2007 compared to 2003. Indonesia's status change from oil net-exporter to oil net-importer country recently has increased Indonesia's concern over energy security. Due to this, oil import becomes center of attention in the dynamics of Indonesia's energy security. Conventional studies addressing Indonesia's energy security have focused on energy production sector. This study explores Indonesia-s energy security considering energy import sector by modeling and simulating Indonesia-s energy-related policies using system dynamics. Simulation result of Indonesia's energy security in 2020 in Business-As-Usual scenario shows that in term of supply demand ratio, energy security will be very high, but also it poses high dependence on energy import. The Alternative scenario result shows lower energy security in term of supply demand ratio and much lower dependence on energy import. It is also found that the Alternative scenario produce lower GDP growth.
Abstract: The aim of the paper work is to investigate and predict
the static performance of journal bearing in turbulent flow condition
considering micropolar lubrication. The Reynolds equation has been
modified considering turbulent micropolar lubrication and is solved
for steady state operations. The Constantinescu-s turbulence model is
adopted using the coefficients. The analysis has been done for a
parallel and inertia less flow. Load capacity and friction factor have
been evaluated for various operating parameters.
Abstract: Stairway Ushtobin Village is one of the five villages with original and sustainable architecture in Northwest of Iran along the border of Armenia, which has been able to maintain its environment and sustainable ecosystem. Studying circulation, function and scale (grand, medium and minor) of space, ratio of full and empty spaces, number and height of stairs, ratio of compound volume to luxury spaces, openings, type of local masonry (stone, mud, wood) and form of covering elements have been carried out in four houses of this village comparatively as some samples in this article, and furthermore, this article analyzes that the architectural shapes and organic texture of the village meet the needs of cold and dry climate. Finally, some efficient plans are offered suiting the present needs of the village to have a sustainable architecture.
Abstract: Utilization of waste material in asphalt pavement
would be beneficial in order to find an alternative solution to increase
service life of asphalt pavement and reduce environmental pollution
as well. One of these waste materials is Polyethylene Terephthalate
(PET) which is a type of polyester material and is produced in a large
extent. This research program is investigating the effects of adding
waste PET particles into the asphalt mixture with a maximum size of
2.36 mm. Different percentages of PET were added into the mixture
during dry process. Gap-graded mixture (SMA 14) and PG 80-100
asphalt binder have been used for this study. To evaluate PET
reinforced asphalt mixture different laboratory investigations have
been conducted on specimens. Marshall Stability test was carried
out. Besides, stiffness modulus test and indirect tensile fatigue test
were conducted on specimens at optimum asphalt content. It was
observed that in many cases PET reinforced SMA mixture had better
mechanical properties in comparison with control mixture.
Abstract: In this work a visual and reactive contour following
behaviour is learned by reinforcement. With artificial vision the
environment is perceived in 3D, and it is possible to avoid obstacles
that are invisible to other sensors that are more common in mobile
robotics. Reinforcement learning reduces the need for intervention in
behaviour design, and simplifies its adjustment to the environment,
the robot and the task. In order to facilitate its generalisation to other
behaviours and to reduce the role of the designer, we propose a
regular image-based codification of states. Even though this is much
more difficult, our implementation converges and is robust. Results
are presented with a Pioneer 2 AT on a Gazebo 3D simulator.
Abstract: A new hybrid method to realise high-precision
distortion determination for optical ultra-precision 3D measurement
systems based on stereo cameras using active light projection is
introduced. It consists of two phases: the basic distortion
determination and the refinement. The refinement phase of the
procedure uses a plane surface and projected fringe patterns as
calibration tools to determine simultaneously the distortion of both
cameras within an iterative procedure. The new technique may be
performed in the state of the device “ready for measurement" which
avoids errors by a later adjustment. A considerable reduction of
distortion errors is achieved and leads to considerable improvements
of the accuracy of 3D measurements, especially in the precise
measurement of smooth surfaces.
Abstract: The use of 3D computer-aided design (CAD) models
to support construction project planning has been increasing in the
previous year. 3D CAD models reveal more planning ideas by
visually showing the construction site environment in different stages
of the construction process. Using 3D CAD models together with
scheduling software to prepare construction plan can identify errors
in process sequence and spatial arrangement, which is vital to the
success of a construction project. A number of 4D (3D plus time)
CAD tools has been developed and utilized in different construction
projects due to the awareness of their importance. Virtual prototyping
extends the idea of 4D CAD by integrating more features for
simulating real construction process. Virtual prototyping originates
from the manufacturing industry where production of products such
as cars and airplanes are virtually simulated in computer before they
are built in the factory. Virtual prototyping integrates 3D CAD,
simulation engine, analysis tools (like structural analysis and
collision detection), and knowledgebase to streamline the whole
product design and production process. In this paper, we present the
application of a virtual prototyping software which has been used in
a few construction projects in Hong Kong to support construction
project planning. Specifically, the paper presents an implementation
of virtual prototyping in a residential building project in Hong Kong.
The applicability, difficulties and benefits of construction virtual
prototyping are examined based on this project.
Abstract: The trend in the world of Information Technology
(IT) is getting increasingly large and difficult projects rather than
smaller and easier. However, the data on large-scale IT project
success rates provide cause for concern. This paper seeks to answer
why large-scale IT projects are different from and more difficult than
other typical engineering projects. Drawing on the industrial
experience, a compilation of the conditions that influence failure is
presented. With a view to improve success rates solutions are
suggested.
Abstract: In a metal forming process, the friction between the
material and the tools influences the process by modifying the stress
distribution of the workpiece. This frictional behaviour is often taken
into account by using a constant coefficient of friction in the finite
element simulations of sheet metal forming processes. However,
friction coefficient varies in time and space with many parameters.
The Stribeck friction model is investigated in this study to predict
springback behaviour of AA6061-T4 sheets during V-bending
process. The coefficient of friction in Stribeck curve depends on
sliding velocity and contact pressure. The plane-strain bending
process is simulated in ABAQUS/Standard. We compared the
computed punch load-stroke curves and springback related to the
constant coefficient of friction with the defined friction model. The
results clearly showed that the new friction model provides better
agreement between experiments and results of numerical simulations.
The influence of friction models on stress distribution in the
workpiece is also studied numerically
Abstract: Water samples were collected from river Pandu at six
stations where human and animal activities were high. Composite
samples were analyzed for dissolved oxygen (DO), biochemical
oxygen demand (BOD), chemical oxygen demand (COD) , pH values
during dry and wet seasons as well as the harmattan period. The total
data points were used to establish relationships between the
parameters and data were also subjected to statistical analysis and
expressed as mean ± standard error of mean (SEM) at a level of
significance of p
Abstract: The demands of taller structures are becoming imperative almost everywhere in the world in addition to the challenges of material and labor cost, project time line etc. This paper conducted a study keeping in view the challenging nature of high-rise construction with no generic rules for deflection minimizations and frequency control. The effects of cyclonic wind and provision of outriggers on 28-storey, 42-storey and 57-storey are examined in this paper and certain conclusions are made which would pave way for researchers to conduct further study in this particular area of civil engineering. The results show that plan dimensions have vital impacts on structural heights. Increase of height while keeping the plan dimensions same, leads to the reduction in the lateral rigidity. To achieve required stiffness increase of bracings sizes as well as introduction of additional lateral resisting system such as belt truss and outriggers is required.
Abstract: The objective of this paper is the introduction to a
unified optimization framework for research and education. The
OPTILIB framework implements different general purpose algorithms
for combinatorial optimization and minimum search on standard continuous
test functions. The preferences of this library are the straightforward
integration of new optimization algorithms and problems
as well as the visualization of the optimization process of different
methods exploring the search space exclusively or for the real time
visualization of different methods in parallel. Further the usage of
several implemented methods is presented on the basis of two use
cases, where the focus is especially on the algorithm visualization.
First it is demonstrated how different methods can be compared
conveniently using OPTILIB on the example of different iterative
improvement schemes for the TRAVELING SALESMAN PROBLEM.
A second study emphasizes how the framework can be used to find
global minima in the continuous domain.
Abstract: Khatunabad area is situated geologically in Urmieh-
Dokhtar magmatic belt in NW of Iran. In this research, studied area
has been investigated in order to recognize the potential copper and
molybdenum-bearing target areas. The survey layers include the
lithologic units, alteration, geochemical result, tectonics and copper
and molybdenum occurrence. As an accurate decision can have a
considerable effect on exploration plans, so in this efforts have been
made to make use of new combination method. For this purpose, the
analytical hierarchy process was used and revealed highly potential
copper and molybdenum mineralization areas. Based on achieved
results, geological perspective in north of studied area is appropriate
for advance stage, especially for subsurface exploration in future.