Abstract: Iterative learning control aims to achieve zero tracking
error of a specific command. This is accomplished by iteratively
adjusting the command given to a feedback control system, based on
the tracking error observed in the previous iteration. One would like
the iterations to converge to zero tracking error in spite of any error
present in the model used to design the learning law. First, this need
for stability robustness is discussed, and then the need for robustness
of the property that the transients are well behaved. Methods of
producing the needed robustness to parameter variations and to
singular perturbations are presented. Then a method involving
reverse time runs is given that lets the world behavior produce the
ILC gains in such a way as to eliminate the need for a mathematical
model. Since the real world is producing the gains, there is no issue
of model error. Provided the world behaves linearly, the approach
gives an ILC law with both stability robustness and good transient
robustness, without the need to generate a model.
Abstract: This paper presents a new true RMS-to-DC converter
circuit based on a square-root-domain squarer/divider. The circuit is
designed by employing up-down translinear loop and using of
MOSFET transistors that operate in strong inversion saturation
region. The converter offer advantages of two-quadrant input current,
low circuit complexity, low supply voltage (1.2V) and immunity
from the body effect. The circuit has been simulated by HSPICE.
The simulation results are seen to conform to the theoretical analysis
and shows benefits of the proposed circuit.
Abstract: Termination Mechanism is an indispensible part of the
emergency management mechanism. Despite of its importance in both
theory and practice, it is almost a brand new field for researching. The
concept of termination mechanism is proposed firstly in this paper,
and the design and implementation which are helpful to guarantee the
effect and integrity of emergency management are discussed secondly.
Starting with introduction of the problems caused by absent
termination and incorrect termination, the essence of termination
mechanism is analyzed, a model based on Optimal Stopping Theory is
constructed and the termination index is given. The model could be
applied to find the best termination time point.. Termination decision
should not only be concerned in termination stage, but also in the
whole emergency management process, which makes it a dynamic
decision making process. Besides, the main subjects and the procedure
of termination are illustrated after the termination time point is given.
Some future works are discussed lastly.
Abstract: The characteristics of fluid flow and phase separation
in an oil-water separator were numerically analysed as part of the
work presented herein. Simulations were performed for different
velocities and droplet diameters, and the way this parameters can
influence the separator geometry was studied.
The simulations were carried out using the software package
Fluent 6.2, which is designed for numerical simulation of fluid flow
and mass transfer. The model consisted of a cylindrical horizontal
separator. A tetrahedral mesh was employed in the computational
domain. The condition of two-phase flow was simulated with the
two-fluid model, taking into consideration turbulence effects using
the k-ε model.
The results showed that there is a strong dependency of phase
separation on mixture velocity and droplet diameter. An increase in
mixture velocity will bring about a slow down in phase separation
and as a consequence will require a weir of greater height. An
increase in droplet diameter will produce a better phase separation.
The simulations are in agreement with results reported in literature
and show that CFD can be a useful tool in studying a horizontal oilwater
separator.
Abstract: This paper shows a simple and effective approach to
the design and implementation of Industrial Information Systems
(IIS) oriented to control the characteristics of each individual product manufactured in a production line and also their manufacturing conditions. The particular products considered in this work are large steel strips that are coiled just after their manufacturing. However, the approach is directly applicable to coiled strips in other industries, like
paper, textile, aluminum, etc. These IIS provide very detailed information of each manufactured product, which complement the general information managed by the ERP system of the production line. In spite of the high importance of this type of IIS to guarantee and improve the quality of the products manufactured in many industries, there are very few works about them in the technical literature. For this reason, this paper represents an important contribution to the development of this type of IIS, providing guidelines for their design, implementation and exploitation.
Abstract: We have devised a thermal carpet cloak theoretically
and implemented in silicon using layered metamaterial. The layered
metamaterial is composed of single crystalline silicon and its phononic
crystal. The design is based on a coordinate transformation. We
demonstrate the result with numerical simulation. Great cloaking
performance is achieved as a thermal insulator is well hidden under the
thermal carpet cloak. We also show that the thermal carpet cloak can
even the temperature on irregular surface. Using thermal carpet cloak
to manipulate the heat conduction is effective because of its low
complexity.
Abstract: In this paper effect of stator slots structure and
switching angle on a cylindrical single-phase brushless direct current
motor (BLDC) is analyzed. BLDC motor with three different
structures for stator slots is designed by using RMxprt software and
efficiency of BLDC motor for different structures in full-load
condition has been presented. Then the BLDC motor in different
conditions by using Maxwell 3D software is designed and with finite
element method is analyzed electromagnetically. At the end with the
use of MATLAB software influence of switching angle on motor
performance investigated and optimal angle has been determined.
The results indicate that with correct choosing of stator slots structure
and switching angle, maximum efficiency can be found.
Abstract: The biomarker for colorectal cancer (CRC) is CEACAM-6 antigen (C6AG). Therefore, this study aims to develop a novel, simple and low-cost CEACAM-6 antigen immumosensor (C6AG-IMS), based on electrical impedance measurement, for precise determination of C6AG. A low-cost screen-printed graphite electrode was constructed and used as the sensor, with CEACAM-6 antibody (C6AB) immobilized on it. The procedures of sensor fabrication and antibody immobilization are simple and low-cost. Measurement of the electrical impedance at a definite frequency ranges (0.43 – 1.26 MHz) showed that the C6AG-IMS has an excellent linear (r2>0.9) response range (8.125 – 65 pg/mL), covering the normal physiological and pathological ranges of blood C6AG levels. Also, the C6AG-IMS has excellent reliability and validity, with the intraclass correlation coefficient being 0.97. In conclusion, a novel, simple, low-cost and reliable C6AG-IMS was designed and developed, being able to accurately determine blood C6AG levels in the range of pathological and normal physiological regions. The C6AG-IMS can provide a point-of-care and immediate screening results to the user at home.
Abstract: This paper describes a computer-aided design for
design of the concave globoidal cam with cylindrical rollers and
swinging follower. Four models with different modeling methods are
made from the same input data. The input data are angular input and
output displacements of the cam and the follower and some other
geometrical parameters of the globoidal cam mechanism. The best
cam model is the cam which has no interference with the rollers
when their motions are simulated in assembly conditions. The
angular output displacement of the follower for the best cam is also
compared with that of in the input data to check errors. In this study,
Pro/ENGINEER® Wildfire 2.0 is used for modeling the cam,
simulating motions and checking interference and errors of the
system.
Abstract: This paper proposes a smart design strategy for a sequential detector to reliably detect the primary user-s signal, especially in fast fading environments. We study the computation of the log-likelihood ratio for coping with a fast changing received signal and noise sample variances, which are considered random variables. First, we analyze the detectability of the conventional generalized log-likelihood ratio (GLLR) scheme when considering fast changing statistics of unknown parameters caused by fast fading effects. Secondly, we propose an efficient sensing algorithm for performing the sequential probability ratio test in a robust and efficient manner when the channel statistics are unknown. Finally, the proposed scheme is compared to the conventional method with simulation results with respect to the average number of samples required to reach a detection decision.
Abstract: Metal stamping die design is a complex, experiencebased
and time-consuming task. Various artificial intelligence (AI)
techniques are being used by worldwide researchers for stamping die
design to reduce complexity, dependence on human expertise and
time taken in design process as well as to improve design efficiency.
In this paper a comprehensive review of applications of AI
techniques in manufacturability evaluation of sheet metal parts, die
design and process planning of metal stamping die is presented.
Further the salient features of major research work published in the
area of metal stamping are presented in tabular form and scope of
future research work is identified.
Abstract: A motion protection system is designed for a parallel
motion platform with subsided cabin. Due to its complex structure,
parallel mechanism is easy to encounter interference problems
including link length limits, joints limits and self-collision. Thus a
virtual spring algorithm in operational space is developed for the
motion protection system to avoid potential damages caused by
interference. Simulation results show that the proposed motion
protection system can effectively eliminate interference problems and
ensure safety of the whole motion platform.
Abstract: Nowadays it is a trend for electronic circuit designers to
integrate all system components on a single-chip. This paper proposed
the design of a single-chip proportional to absolute temperature
(PTAT) sensor including a voltage reference circuit using CEDEC
0.18m CMOS Technology. It is a challenge to design asingle-chip
wide range linear response temperature sensor for many applications.
The channel widths between the compensation transistor and the
reference transistor are critical to design the PTAT temperature sensor
circuit. The designed temperature sensor shows excellent linearity
between -100°C to 200° and the sensitivity is about 0.05mV/°C.
The chip is designed to operate with a single voltage source of 1.6V.
Abstract: Vehicle suspension design must fulfill
some conflicting criteria. Among those is ride comfort
which is attained by minimizing the acceleration
transmitted to the sprung mass, via suspension spring
and damper. Also good handling of a vehicle is a
desirable property which requires stiff suspension and
therefore is in contrast with a vehicle with good ride.
Among the other desirable features of a suspension is
the minimization of the maximum travel of suspension.
This travel which is called suspension working space in
vehicle dynamics literature is also a design constraint
and it favors good ride. In this research a full car 8
degrees of freedom model has been developed and the
three above mentioned criteria, namely: ride, handling
and working space has been adopted as objective
functions. The Multi Objective Programming (MOP)
discipline has been used to find the Pareto Front and
some reasoning used to chose a design point between
these non dominated points of Pareto Front.
Abstract: The traditional Failure Mode and Effects Analysis
(FMEA) uses Risk Priority Number (RPN) to evaluate the risk level
of a component or process. The RPN index is determined by
calculating the product of severity, occurrence and detection indexes.
The most critically debated disadvantage of this approach is that
various sets of these three indexes may produce an identical value of
RPN. This research paper seeks to address the drawbacks in
traditional FMEA and to propose a new approach to overcome these
shortcomings. The Risk Priority Code (RPC) is used to prioritize
failure modes, when two or more failure modes have the same RPN.
A new method is proposed to prioritize failure modes, when there is a
disagreement in ranking scale for severity, occurrence and detection.
An Analysis of Variance (ANOVA) is used to compare means of
RPN values. SPSS (Statistical Package for the Social Sciences)
statistical analysis package is used to analyze the data. The results
presented are based on two case studies. It is found that the proposed
new methodology/approach resolves the limitations of traditional
FMEA approach.
Abstract: This study presents a systematic analysis of the
dynamic behaviors of a gear-bearing system with porous squeeze film
damper (PSFD) under nonlinear suspension, nonlinear oil-film force
and nonlinear gear meshing force effect. It can be found that the
system exhibits very rich forms of sub-harmonic and even the chaotic
vibrations. The bifurcation diagrams also reveal that greater values of
permeability may not only improve non-periodic motions effectively,
but also suppress dynamic amplitudes of the system. Therefore, porous
effect plays an important role to improve dynamic stability of
gear-bearing systems or other mechanical systems. The results
presented in this study provide some useful insights into the design
and development of a gear-bearing system for rotating machinery that
operates in highly rotational speed and highly nonlinear regimes.
Abstract: This paper deals optimized model to investigate the
effects of peak current, pulse on time and pulse off time in EDM performance on material removal rate of titanium alloy utilizing copper tungsten as electrode and positive polarity of the electrode. The experiments are carried out on Ti6Al4V. Experiments were
conducted by varying the peak current, pulse on time and pulse off time. A mathematical model is developed to correlate the influences of these variables and material removal rate of workpiece. Design of
experiments (DOE) method and response surface methodology
(RSM) techniques are implemented. The validity test of the fit and adequacy of the proposed models has been carried out through
analysis of variance (ANOVA). The obtained results evidence that as
the material removal rate increases as peak current and pulse on time
increases. The effect of pulse off time on MRR changes with peak ampere. The optimum machining conditions in favor of material removal rate are verified and compared. The optimum machining
conditions in favor of material removal rate are estimated and verified with proposed optimized results. It is observed that the developed model is within the limits of the agreeable error (about
4%) when compared to experimental results. This result leads to desirable material removal rate and economical industrial machining to optimize the input parameters.
Abstract: Software reliability prediction gives a great opportunity to measure the software failure rate at any point throughout system test. A software reliability prediction model provides with the technique for improving reliability. Software reliability is very important factor for estimating overall system reliability, which depends on the individual component reliabilities. It differs from hardware reliability in that it reflects the design perfection. Main reason of software reliability problems is high complexity of software. Various approaches can be used to improve the reliability of software. We focus on software reliability model in this article, assuming that there is a time redundancy, the value of which (the number of repeated transmission of basic blocks) can be an optimization parameter. We consider given mathematical model in the assumption that in the system may occur not only irreversible failures, but also a failure that can be taken as self-repairing failures that significantly affect the reliability and accuracy of information transfer. Main task of the given paper is to find a time distribution function (DF) of instructions sequence transmission, which consists of random number of basic blocks. We consider the system software unreliable; the time between adjacent failures has exponential distribution.
Abstract: Complex networks have been intensively studied across
many fields, especially in Internet technology, biological engineering,
and nonlinear science. Software is built up out of many interacting
components at various levels of granularity, such as functions, classes,
and packages, representing another important class of complex networks.
It can also be studied using complex network theory. Over the
last decade, many papers on the interdisciplinary research between
software engineering and complex networks have been published.
It provides a different dimension to our understanding of software
and also is very useful for the design and development of software
systems. This paper will explore how to use the complex network
theory to analyze software structure, and briefly review the main
advances in corresponding aspects.
Abstract: Existing literature ondesign reasoning seems to give
either one sided accounts on expert design behaviour based on
internal processing. In the same way ecological theoriesseem to
focus one sidedly on external elementsthat result in a lack of unifying
design cognition theory. Although current extended design cognition
studies acknowledge the intellectual interaction between internal and
external resources, there still seems to be insufficient understanding
of the complexities involved in such interactive processes. As
such,this paper proposes a novelmulti-directional model for design
researchers tomap the complex and dynamic conduct controlling
behaviour in which both the computational and ecological
perspectives are integrated in a vertical manner. A clear distinction
between identified intentional and emerging physical drivers, and
relationships between them during the early phases of experts- design
process, is demonstrated by presenting a case study in which the
model was employed.