Abstract: An international cooperation between educators in
Australia and the US has led to a reconceptualization of the teaching
of a library science course at Appalachian State University. The
pedagogy of Action Learning coupled with a 3D virtual learning
environment immerses students in a social constructivist learning
space that incorporates and supports interaction and reflection. The
intent of this study was to build a bridge between theory and practice
by providing students with a tool set that promoted personal and
social reflection, and created and scaffolded a community of practice.
Besides, action learning is an educational process whereby the fifty
graduate students experienced their own actions and experience to
improve performance.
Abstract: Polyurethanes (PURs) are very versatile polymeric
materials with a wide range of physical and chemical properties.
PURs have desirable properties such as high abrasion resistance, tear
strength, shock absorption, flexibility and elasticity. Although they
have relatively poor thermal stability, this can be improved by using
treated clay. Polyurethane/clay nanocomposites have been
synthesized from renewable sources. A polyol for the production of
polyurethane by reaction with an isocyanate was obtained by the
synthesis of palm oil-based oleic acid with glycerol. Dodecylbenzene
sulfonic acid (DBSA) was used as catalyst and emulsifier. The
unmodified clay (kunipia-F) was treated with cetyltrimethyl
ammonium bromide (CTAB-mont) and octadodecylamine (ODAmont).
The d-spacing in CTAB-mont and ODA-mont were 1.571 nm
and 1.798 nm respectively and larger than that of the pure-mont
(1.142 nm). The organoclay was completely intercalated in the
polyurethane, as confirmed by a wide angle x-ray diffraction
(WAXD) pattern.
The results showed that adding clay demonstrated better thermal
stability in comparison with the virgin polyurethane. Onset
degradation of pure PU is at 200oC, and is lower than that of the
CTAB-mont PU and ODA-mont PU which takes place at about
318oC and 330oC, respectively. The mechanical properties (including
the dynamic mechanical properties) of pure polyurethane (PU) and
PU/clay nanocomposites, were measured. The modified organoclay
had a remarkably beneficial effect on the strength and elongation at
break of the nanocomposites, which both increased with increasing
clay content with the increase of the tensile strength of more than
214% and 267% by the addition of only 5 wt% of the
montmorillonite CTAB-mont PU and ODA-mont PU, respectively.
Abstract: In this paper, an ultra low power and low jitter 12bit
CMOS digitally controlled oscillator (DCO) design is presented.
Based on a ring oscillator implemented with low power Schmitt
trigger based inverters. Simulation of the proposed DCO using 32nm
CMOS Predictive Transistor Model (PTM) achieves controllable
frequency range of 550MHz~830MHz with a wide linearity and high
resolution. Monte Carlo simulation demonstrates that the time-period
jitter due to random power supply fluctuation is under 31ps and the
power consumption is 0.5677mW at 750MHz with 1.2V power
supply and 0.53-ps resolution. The proposed DCO has a good
robustness to voltage and temperature variations and better linearity
comparing to the conventional design.
Abstract: Nonlinear finite element method and Serendipity eight
nodes element are used for determining of ground surface settlement
due to tunneling. Linear element with elastic behavior is used for
modeling of lining. Modified Generalized plasticity model with nonassociated
flow rule is applied for analysis of a tunnel in Sao Paulo –
Brazil. The tunnel had analyzed by Lades- model with 16 parameters.
In this work modified Generalized Plasticity is used with 10
parameters, also Mohr-Coulomb model is used to analysis the tunnel.
The results show good agreement with observed results of field data
by modified Generalized Plasticity model than other models. The
obtained result by Mohr-Coulomb model shows less settlement than
other model due to excavation.
Abstract: Development of intelligent assembly cell conception includes new solution kind of how to create structures of automated and flexible assembly system. The current trend of the final product quality increasing is affected by time analysis of the entire manufacturing process. The primary requirement of manufacturing is to produce as many products as soon as possible, at the lowest possible cost, but of course with the highest quality. Such requirements may be satisfied only if all the elements entering and affecting the production cycle are in a fully functional condition. These elements consist of sensory equipment and intelligent control elements that are essential for building intelligent manufacturing systems. Intelligent behavior of the system as the control system will repose on monitoring of important parameters of the system in the real time. Intelligent manufacturing system itself should be a system that can flexibly respond to changes in entering and exiting the process in interaction with the surroundings.
Abstract: The results obtained after incorporating the competence “creativity" to the subject Technical Drawing of the first course of the Degree in Forestry, Technical University of Madrid, are presented in this study.At first, learning activities which could serve two functions at the same time -developing students- creativity and developing other specific competences of the subject- were considered. Besides, changes in the assessment procedure were made and a method which analyzes two aspects of the assessment of the competence creativity was established. On the one hand, the products are evaluated by analyzing the outcomes obtained by students in the essays suggested and by establishing a parameter to assess the creativity expressed in those essays. On the other, an assessment of the student is directly carried out through a psychometric test which has been previously chosen by the team.Moreover, these results can be applied to similar or could be of general application.
Abstract: Genetic algorithms (GAs) have been widely used for
global optimization problems. The GA performance depends highly
on the choice of the search space for each parameter to be optimized.
Often, this choice is a problem-based experience. The search space
being a set of potential solutions may contain the global optimum
and/or other local optimums. A bad choice of this search space
results in poor solutions. In this paper, our approach consists in
extending the search space boundaries during the GA optimization,
only when it is required. This leads to more diversification of GA
population by new solutions that were not available with fixed search
space boundaries. So, these dynamic search spaces can improve the
GA optimization performances. The proposed approach is applied to
power system stabilizer optimization for multimachine power system
(16-generator and 68-bus). The obtained results are evaluated and
compared with those obtained by ordinary GAs. Eigenvalue analysis
and nonlinear system simulation results show the effectiveness of the
proposed approach to damp out the electromechanical oscillation and
enhance the global system stability.
Abstract: From the beginning of creation, human being has ever
fought against the ecosystem by changes has made in environment.
The most environmental changes on the nature have been done after
starting the concentrated life in the same region. Dams are one of the
most important buildings in water resources and transferring. These
buildings have been made from old times without access to
hydrological, hydraulically, hydro mechanical information. Dams
have positive and negative effects on environment. Constructing a
dam relatively causes equal ecological consequences. According to
different criteria, environmental effects of dams can lead short term
and long term damages. These effects may influence on the situation
and treatment of meteorology, biology, culture, ancient works, etc
and severely causes to change and complicate it. So considering
importance of positive effects of dam construction, it is necessary to
minimize negative environmental effects of dams to achieve a stable
development. In this article the considered effects and their solutions
in influencing on assessment of destructive environmental effects of
dams construction have been surveyed and presented.
Abstract: From environmental aspect purification of ammonia
containing wastewater is expected. High efficiency ammonia
desorption can be done from the water by air on proper temperature.
After the desorption process, ammonia can be recovered and used in
another technology. The calculation method described below give
some methods to find either the minimum column height or ammonia
rich solution of the effluent.
Abstract: This paper addresses linear quadratic regulation (LQR)
for variable speed variable pitch wind turbines. Because of the
inherent nonlinearity of wind turbine, a set of operating conditions is
identified and then a LQR controller is designed for each operating
point. The feedback controller gains are then interpolated linearly to
get control law for the entire operating region. Besides, the
aerodynamic torque and effective wind speed are estimated online to
get the gain-scheduling variable for implementing the controller. The
potential of the method is verified through simulation with the help of
MATLAB/Simulink and GH Bladed. The performance and
mechanical load when using LQR are also compared with that when
using PI controller.
Abstract: One major difficulty that faces developers of
concurrent and distributed software is analysis for concurrency based
faults like deadlocks. Petri nets are used extensively in the
verification of correctness of concurrent programs. ECATNets are a
category of algebraic Petri nets based on a sound combination of
algebraic abstract types and high-level Petri nets. ECATNets have
'sound' and 'complete' semantics because of their integration in
rewriting logic and its programming language Maude. Rewriting
logic is considered as one of very powerful logics in terms of
description, verification and programming of concurrent systems We
proposed previously a method for translating Ada-95 tasking
programs to ECATNets formalism (Ada-ECATNet) and we showed
that ECATNets formalism provides a more compact translation for
Ada programs compared to the other approaches based on simple
Petri nets or Colored Petri nets. We showed also previously how the
ECATNet formalism offers to Ada many validation and verification
tools like simulation, Model Checking, accessibility analysis and
static analysis. In this paper, we describe the implementation of our
translation of the Ada programs into ECATNets.
Abstract: Environmental contamination is a common problem in ex-industrial and industrial sites. This article gives a brief description of general applied environmental investigation methodologies and possible remediation applications in Latvia. Most of contaminated areas are situated in former and active industrial, military areas and ports. Industrial and logistic activities very often have been with great impact for more than hundred years thus the contamination level with heavy metals, hydrocarbons, pesticides, persistent organic pollutants is high and is threatening health and environment in general. 242 territories now are numbered as contaminated and fixed in the National Register of contaminated territories in Latvia. Research and remediation of contamination in densely populated areas are of important environmental policy domain. Four different investigation case studies of contaminated areas are given describing the history of use, environmental quality assessment as well as planned environmental management actions. All four case study locations are situated in Riga - the capital of the Republic of Latvia. The aim of this paper is to analyze the situation and problems with management of contaminated areas in Latvia, give description of field research methods and recommendations for remediation industry based on scientific data and innovations.
Abstract: Robust nonlinear integrated navigation of GPS and
low cost MEMS is a hot topic of research these days. A robust filter
is required to cope up with the problem of unpredictable
discontinuities and colored noises associated with low cost sensors.
H∞ filter is previously used in Extended Kalman filter and Unscented
Kalman filter frame. Unscented Kalman filter has a problem of
Cholesky matrix factorization at each step which is a very unstable
operation. To avoid this problem in this research H∞ filter is
designed in Square root Unscented filter framework and found 50%
more robust towards increased level of colored noises.
Abstract: The paper presents the design of a mini-UAV attitude
controller using the backstepping method. Starting from the nonlinear
dynamic equations of the mini-UAV, by using the backstepping
method, the author of this paper obtained the expressions of the
elevator, rudder and aileron deflections, which stabilize the UAV, at
each moment, to the desired values of the attitude angles. The attitude
controller controls the attitude angles, the angular rates, the angular
accelerations and other variables that describe the UAV longitudinal
and lateral motions. To design the nonlinear controller, by using the
backstepping technique, the nonlinear equations and the Lyapunov
analysis have been directly used. The designed controller has been
implemented in Matlab/Simulink environment and its effectiveness
has been tested with a campaign of numerical simulations using data
from the UAV flight tests. The obtained results are very good and
they are better than the ones found in previous works.
Abstract: It is important for an autonomous mobile robot to know
where it is in any time in an indoor environment. In this paper, we
design a relative self-localization algorithm. The algorithm compare
the interest point in two images and compute the relative displacement
and orientation to determent the posture. Firstly, we use the SURF
algorithm to extract the interest points of the ceiling. Second, in order
to reduce amount of calculation, a replacement SURF is used to extract
orientation and description of the interest points. At last, according to
the transformation of the interest points in two images, the relative
self-localization of the mobile robot will be estimated greatly.
Abstract: This work deals with the design of the robotic assembly
system for the roller clamps. The task is characterized by high speed,
high yield and safety engagement. This paper describes the design of
different parts of an automated high speed machine to assemble the
parts of roller clamps. The roller clamp robotic assembly system
performs various processes in the assembly line which include clamp
body and roller feeding, inserting the roller into the clamp body, and
dividing the rejected clamp and successfully assembled clamp into
their own tray. The electrical/electronics design of the machine is
discussed. The target is to design a cost effective, minimum
maintenance and high speed machine for the industry applications.
Abstract: In this study the elastic-plastic stress distribution in
weld-bonded joint, fabricated from austenitic stainless steel (AISI
304) sheet of 1.00 mm thickness and Epoxy adhesive Araldite 2011,
subjected to axial loading is investigated. This is needed to improve
design procedures and welding codes, and saving efforts in the
cumbersome experiments and analysis. Therefore, a complete 3-D
finite element modelling and analysis of spot welded, bonded and
weld-bonded joints under axial loading conditions is carried out. A
comprehensive systematic experimental program is conducted to
determine many properties and quantities, of the base metals and the
adhesive, needed for FE modelling, such like the elastic – plastic
properties, modulus of elasticity, fracture limit, the nugget and heat
affected zones (HAZ) properties, etc. Consequently, the finite
element models developed, for each case, are used to evaluate
stresses distributions across the entire joint, in both the elastic and
plastic regions. The stress distribution curves are obtained,
particularly in the elastic regions and found to be consistent and in
excellent agreement with the published data. Furthermore, the
stresses distributions are obtained in the weld-bonded joint and
display the best results with almost uniform smooth distribution
compared to spot and bonded cases. The stress concentration peaks at
the edges of the weld-bonded region, are almost eliminated resulting
in achieving the strongest joint of all processes.
Abstract: In this paper a polymer electrolyte membrane (PEM)
fuel cell power system including burner, steam reformer, heat
exchanger and water heater has been considered to meet the
electrical, heating, cooling and domestic hot water loads of
residential building which in Tehran. The system uses natural gas as
fuel and works in CHP mode. Design and operating conditions of a
PEM fuel cell system is considered in this study. The energy
requirements of residential building and the number of fuel cell
stacks to meet them have been estimated. The method involved
exergy analysis and entropy generation thorough the months of the
year. Results show that all the energy needs of the building can be
met with 12 fuel cell stacks at a nominal capacity of 8.5 kW. Exergy
analysis of the CHP system shows that the increase in the ambient air
temperature from 1oC to 40oC, will have an increase of entropy
generation by 5.73%.Maximum entropy generates for 15 hour in 15th
of June and 15th of July is estimated to amount at 12624 (kW/K).
Entropy generation of this system through a year is estimated to
amount to 1004.54 GJ/k.year.
Abstract: Evolvable hardware (EHW) refers to a selfreconfiguration
hardware design, where the configuration is under
the control of an evolutionary algorithm (EA). A lot of research has
been done in this area several different EA have been introduced.
Every time a specific EA is chosen for solving a particular problem,
all its components, such as population size, initialization, selection
mechanism, mutation rate, and genetic operators, should be selected
in order to achieve the best results. In the last three decade a lot of
research has been carried out in order to identify the best parameters
for the EA-s components for different “test-problems". However
different researchers propose different solutions. In this paper the
behaviour of mutation rate on (1+λ) evolution strategy (ES) for
designing logic circuits, which has not been done before, has been
deeply analyzed. The mutation rate for an EHW system modifies
values of the logic cell inputs, the cell type (for example from AND
to NOR) and the circuit output. The behaviour of the mutation has
been analyzed based on the number of generations, genotype
redundancy and number of logic gates used for the evolved circuits.
The experimental results found provide the behaviour of the mutation
rate to be used during evolution for the design and optimization of
logic circuits. The researches on the best mutation rate during the last
40 years are also summarized.
Abstract: This paper invites to dialogue and reflections on
innovation and entrepreneurship by presenting concepts of innovation
leading to the introduction of a complex theoretical framework;
Cooperative Innovation (CO-IN). CO-IN is a didactic model
enhancing and scaffolding processes of cooperation creating
innovation drawing on a Scandinavian tradition.
CO-IN is based on a cross-sectorial and multidisciplinary
approach. We introduce the concept of complementarity to help
capture the validity of diversity and we suggest the concept of “the
space in between" to understand the creation of identity as a
collective mind. We see dialogue and the use of multi modal
techniques as essential tools for conceptualizations giving possibility
for clarification of the complexity and diversity leading to decision
making based on knowledge as commons.
We introduce the didactic design and present our empirical
findings from an innovation workshop in Argentina. In a final
paragraph we reflect on the design as a support of the development of
common ground, collective mind and collective action and the
creation of knowledge as commons to facilitate innovation and
entrepreneurship.