Abstract: In this paper numerous robust fitting procedures are considered in estimating spatial variograms. In spatial statistics, the conventional variogram fitting procedure (non-linear weighted least squares) suffers from the same outlier problem that has plagued this method from its inception. Even a 3-parameter model, like the variogram, can be adversely affected by a single outlier. This paper uses the Hogg-Type adaptive procedures to select an optimal score function for a rank-based estimator for these non-linear models. Numeric examples and simulation studies will demonstrate the robustness, utility, efficiency, and validity of these estimates.
Abstract: Due to the increasing growth of internet users, the emerging applications of multicast are growing day by day and there is a requisite for the design of high-speed switches/routers. Huge amounts of effort have been done into the research area of multicast switch fabric design and algorithms. Different traffic scenarios are the influencing factor which affect the throughput and delay of the switch. The pointer based multicast scheduling algorithms are not performed well under non-uniform traffic conditions. In this work, performance of the switch has been analyzed by applying the advanced multicast scheduling algorithm OQSMS (Optimal Queue Selection Based Multicast Scheduling Algorithm), MDDR (Multicast Due Date Round-Robin Scheduling Algorithm) and MDRR (Multicast Dual Round-Robin Scheduling Algorithm). The results show that OQSMS achieves better switching performance than other algorithms under the uniform, non-uniform and bursty traffic conditions and it estimates optimal queue in each time slot so that it achieves maximum possible throughput.
Abstract: As greenhouse effect has been recognized as serious environmental problem of the world, interests in carbon dioxide (CO2) emission which comprises major part of greenhouse gas (GHG) emissions have been increased recently. Since construction industry takes a relatively large portion of total CO2 emissions of the world, extensive studies about reducing CO2 emissions in construction and operation of building have been carried out after the 2000s. Also, performance based design (PBD) methodology based on nonlinear analysis has been robustly developed after Northridge Earthquake in 1994 to assure and assess seismic performance of building more exactly because structural engineers recognized that prescriptive code based design approach cannot address inelastic earthquake responses directly and assure performance of building exactly. Although CO2 emissions and PBD approach are recent rising issues on construction industry and structural engineering, there were few or no researches considering these two issues simultaneously. Thus, the objective of this study is to minimize the CO2 emissions and cost of building designed by PBD approach in structural design stage considering structural materials. 4 story and 4 span reinforced concrete building optimally designed to minimize CO2 emissions and cost of building and to satisfy specific seismic performance (collapse prevention in maximum considered earthquake) of building satisfying prescriptive code regulations using non-dominated sorting genetic algorithm-II (NSGA-II). Optimized design result showed that minimized CO2 emissions and cost of building were acquired satisfying specific seismic performance. Therefore, the methodology proposed in this paper can be used to reduce both CO2 emissions and cost of building designed by PBD approach.
Abstract: With the rapid development of computer technology,
the design of computers and keyboards moves towards a trend of
slimness. The change of mobile input devices directly influences
users’ behavior. Although multi-touch applications allow entering
texts through a virtual keyboard, the performance, feedback, and
comfortableness of the technology is inferior to traditional keyboard,
and while manufacturers launch mobile touch keyboards and
projection keyboards, the performance has not been satisfying.
Therefore, this study discussed the design factors of slim
pressure-sensitive keyboards. The factors were evaluated with an
objective (accuracy and speed) and a subjective evaluation
(operability, recognition, feedback, and difficulty) depending on the
shape (circle, rectangle, and L-shaped), thickness (flat, 3mm, and
6mm), and force (35±10g, 60±10g, and 85±10g) of the keyboard.
Moreover, MANOVA and Taguchi methods (regarding
signal-to-noise ratios) were conducted to find the optimal level of each
design factor. The research participants, by their typing speed (30
words/ minute), were divided in two groups. Considering the
multitude of variables and levels, the experiments were implemented
using the fractional factorial design. A representative model of the
research samples were established for input task testing. The findings
of this study showed that participants with low typing speed primarily
relied on vision to recognize the keys, and those with high typing
speed relied on tactile feedback that was affected by the thickness and
force of the keys. In the objective and subjective evaluation, a
combination of keyboard design factors that might result in higher
performance and satisfaction was identified (L-shaped, 3mm, and
60±10g) as the optimal combination. The learning curve was analyzed
to make a comparison with a traditional standard keyboard to
investigate the influence of user experience on keyboard operation.
The research results indicated the optimal combination provided input
performance to inferior to a standard keyboard. The results could serve
as a reference for the development of related products in industry and
for applying comprehensively to touch devices and input interfaces
which are interacted with people.
Abstract: Topology optimization technique utilizes constant
element densities as design parameters. Finally, optimal distribution
contours of the material densities between voids (0) and solids (1) in
design domain represent the determination of topology. It means that
regions with element density values become occupied by solids in
design domain, while there are only void phases in regions where no
density values exist. Therefore the void regions of topology
optimization results provide design information to decide appropriate
depositions of web-opening in structure. Contrary to the basic
objective of the topology optimization technique which is to obtain
optimal topology of structures, this present study proposes a new idea
that topology optimization results can be also utilized for decision of
proper web-opening’s position. Numerical examples of linear
elastostatic structures demonstrate efficiency of methodological
design processes using topology optimization in order to determinate
the proper deposition of web-openings.
Abstract: Particle swarm optimization (PSO) is becoming one of
the most important swarm intelligent paradigms for solving global
optimization problems. Although some progress has been made to
improve PSO algorithms over the last two decades, additional work
is still needed to balance parameters to achieve better numerical
properties of accuracy, efficiency, and stability. In the optimal
PSO algorithm, the optimal weightings of (√ 5 − 1)/2 and (3 − √5)/2 are used for the cognitive factor and the social factor,
respectively. By the same token, the same optimal weightings have
been applied for intensification searches and diversification searches,
respectively. Perturbation and constriction effects are optimally
balanced. Simulations of the de Jong, the Rosenbrock, and the
Griewank functions show that the optimal PSO algorithm indeed
achieves better numerical properties and outperforms the canonical
PSO algorithm.
Abstract: This paper discusses the simulation and experimental work of small Smart Grid containing ten consumers. Smart Grid is characterized by a two-way flow of real-time information and energy. RTP (Real Time Pricing) based tariff is implemented in this work to reduce peak demand, PAR (peak to average ratio) and cost of energy consumed. In the experimental work described here, working of Smart Plug, HEC (Home Energy Controller), HAN (Home Area Network) and communication link between consumers and utility server are explained. Algorithms for Smart Plug, HEC, and utility server are presented and explained in this work. After receiving the Real Time Price for different time slots of the day, HEC interacts automatically by running an algorithm which is based on Linear Programming Problem (LPP) method to find the optimal energy consumption schedule. Algorithm made for utility server can handle more than one off-peak time period during the day. Simulation and experimental work are carried out for different cases. At the end of this work, comparison between simulation results and experimental results are presented to show the effectiveness of the minimization method adopted.
Abstract: Information system risk management helps to reduce
or eliminate risk by implementing appropriate controls. In this paper,
we propose a quantification model of controls impact on information
system risks by automatizing the residual criticality estimation step of
FMECA which is based on a inductive reasoning. For this, we defined
three equations based on type and maturity of controls. For testing,
the values obtained with the model were compared to estimated
values given by interlocutors during different working sessions and
the result is satisfactory. This model allows an optimal assessment of
controls maturity and facilitates risk analysis of information system.
Abstract: Risk management in banking sector is a key issue
linked to financial system stability and its importance has been
elevated by technological developments and emergence of new
financial instruments. In this paper, we improve the model previously
defined for quantifying internal control impact on banking risks by
automatizing the residual criticality estimation step of FMECA. For
this, we defined three equations and a maturity coefficient to obtain
a mathematical model which is tested on all banking processes and
type of risks. The new model allows an optimal assessment of residual
criticality and improves the correlation rate that has become 98%.
Abstract: Flexible satellites are equipped with various appendages which vibrate under the influence of any excitation and make the attitude of the satellite to be unstable. Therefore, the system must be able to adjust to balance the effect of these appendages in order to point accurately and satisfactorily which is one of the most important problems in satellite design. Proportional Integral Derivative (PID) Controller is simple to design and computationally efficient to implement which is used to stabilize the effect of these flexible appendages. However, manual turning of the PID is time consuming, waste energy and money. Particle Swarm Optimization (PSO) is used to tune the parameters of PID Controller. Simulation results obtained show that PSO tuned PID Controller is able to re-orient the spacecraft attitude as well as dampen the effect of mechanical resonance and yields better performance when compared with manually tuned PID Controller.
Abstract: Climate change and sea level rise is one of the greatest challenges facing human beings in the 21st century. Because of sea level rise, several low-lying coastal areas around the globe are at risk of being completely submerged, disappearing under water. Particularly in Viet Nam, the rise in sea level is predicted to result in more frequent and even permanently inundated coastal plains. As a result, land reserving fund of coastal cities is going to be narrowed in near future, while construction ground is becoming increasingly limited due to a rapid growth in population. Faced with this reality, the solutions are being discussed not only in tradition view such as accommodation is raised or moved to higher areas, or “living with the water”, but also forwards to “living on the water”. Therefore, the concept of a sustainable floating community with floating houses based on the precious value of long term historical tradition of water dwellings in Viet Nam would be a sustainable solution for adaptation of climate change and sea level rise in the coastal areas. The sustainable floating community is comprised of sustainability in four components: architecture, environment, socio-economic and living quality. This research paper is focused on sustainability in architectural component of floating community. Through detailed architectural analysis of current floating houses and floating communities in Viet Nam, this research not only accumulates precious values of traditional architecture that need to be preserved and developed in the proposed concept, but also illustrates its weaknesses that need to address for optimal design of the future sustainable floating communities. Based on these studies the research would provide guidelines with appropriate architectural solutions for the concept of sustainable floating community with floating housing units that are adapted to climate change and sea level rise in Viet Nam.
Abstract: As DNA microarray data contain relatively small
sample size compared to the number of genes, high dimensional
models are often employed. In high dimensional models, the selection
of tuning parameter (or, penalty parameter) is often one of the crucial
parts of the modeling. Cross-validation is one of the most common
methods for the tuning parameter selection, which selects a parameter
value with the smallest cross-validated score. However, selecting a
single value as an ‘optimal’ value for the parameter can be very
unstable due to the sampling variation since the sample sizes of
microarray data are often small. Our approach is to choose multiple candidates of tuning parameter
first, then average the candidates with different weights depending
on their performance. The additional step of estimating the weights
and averaging the candidates rarely increase the computational cost,
while it can considerably improve the traditional cross-validation. We
show that the selected value from the suggested methods often lead to
stable parameter selection as well as improved detection of significant
genetic variables compared to the tradition cross-validation via real
data and simulated data sets.
Abstract: The article proposes maximum power point tracking without mechanical sensor using Multilayer Perceptron Neural Network (MLPNN). The aim of article is to reduce the cost and complexity but still retain efficiency. The experimental is that duty cycle is generated maximum power, if it has suitable qualification. The measured data from DC generator, voltage (V), current (I), power (P), turnover rate of power (dP), and turnover rate of voltage (dV) are used as input for MLPNN model. The output of this model is duty cycle for driving the converter. The experiment implemented using Arduino Uno board. This diagram is compared to MPPT using MLPNN and P&O control (Perturbation and Observation control). The experimental results show that the proposed MLPNN based approach is more efficiency than P&O algorithm for this application.
Abstract: This work proposed a multi-objective mathematical programming approach to select the appropriate supply network elements. The multi-item multi-objective production-distribution inventory model is formulated with possible constraints under fuzzy environment. The unit cost has taken under fuzzy environment. The inventory model and warehouse location model has combined to formulate the production-distribution inventory model. Warehouse location is important in supply chain network. Particularly, if a company maintains more selling stores it cannot maintain individual secondary warehouse near to each selling store. Hence, maintaining the optimum number of secondary warehouses is important. Hence, the combined mathematical model is formulated to reduce the total expenditure of the organization by arranging the network of minimum number of secondary warehouses. Numerical example has been taken to illustrate the proposed model.
Abstract: In this paper, a PSO based fractional order PID (FOPID) controller is proposed for concentration control of an isothermal Continuous Stirred Tank Reactor (CSTR) problem. CSTR is used to carry out chemical reactions in industries, which possesses complex nonlinear dynamic characteristics. Particle Swarm Optimization algorithm technique, which is an evolutionary optimization technique based on the movement and intelligence of swarm is proposed for tuning of the controller for this system. Comparisons of proposed controller with conventional and fuzzy based controller illustrate the superiority of proposed PSO-FOPID controller.
Abstract: This paper presents Differential Evolution Algorithm (DEA) based Variable Structure Position Control (VSPC) of Laboratory DC servomotor (LDCSM). DEA is employed for the optimal tuning of Variable Structure Control (VSC) parameters for position control of a DC servomotor. The VSC combines the techniques of Sliding Mode Control (SMC) that gives the advantages of small overshoot, improved step response characteristics, faster dynamic response and adaptability to plant parameter variations, suppressed influences of disturbances and uncertainties in system behavior. The results of the simulation responses of the VSC parameters adjustment by DEA were performed in Matlab Version 2010a platform and yield better dynamic performance compared with the untuned VSC designed.
Abstract: This paper covers application of an elitist selfadaptive
step-size search (ESASS) to optimum design of steel
skeletal structures. In the ESASS two approaches are considered for
improving the convergence accuracy as well as the computational
efficiency of the original technique namely the so called selfadaptive
step-size search (SASS). Firstly, an additional randomness
is incorporated into the sampling step of the technique to preserve
exploration capability of the algorithm during the optimization.
Moreover, an adaptive sampling scheme is introduced to improve the
quality of final solutions. Secondly, computational efficiency of the
technique is accelerated via avoiding unnecessary analyses during the
optimization process using an upper bound strategy. The numerical
results demonstrate the usefulness of the ESASS in the sizing
optimization problems of steel truss and frame structures.
Abstract: Since the advent of the law 86/14 concerning the
exploitation of the national territory by foreign companies in
partnership with the Algerian oil and gas company, the problem of
hydrocarbons metering in the sharing production come out.
More generally, good management counting hydrocarbons can
provide data on the production wells, the field and the reservoir for
medium and long term planning, particularly in the context of the
management and field development.
In this work, we are interested in the transactional metering which
is a very delicate and crucial period in the current context of the new
hydrocarbon’s law characterized by assets system between the
various activities of Sonatrach and its foreign partners.
After a state of the art on hydrocarbons metering devices in
Algeria and elsewhere, we will decline the advantages and
disadvantages of each system, and then we describe the problem to
try to reach an optimal solution.
Abstract: Recent progress in the next generation of automobile
technology is geared towards incorporating information technology
into cars. Collectively called smart cars are bringing intelligence to
cars that provides comfort, convenience and safety. A branch of smart
cars is connected-car system. The key concept in connected-cars is the
sharing of driving information among cars through decentralized
manner enabling collective intelligence. This paper proposes a
foundation of the information model that is necessary to define the
driving information for smart-cars. Road conditions are modeled
through a unique data structure that unambiguously represent the time
variant traffics in the streets. Additionally, the modeled data structure
is exemplified in a navigational scenario and usage using UML.
Optimal driving route searching is also discussed using the proposed
data structure in a dynamically changing road conditions.
Abstract: The irradiation of polymeric materials has received
much attention because it can produce diverse changes in chemical
structure and physical properties. Thus, studying the chemical and
structural changes of polymers is important in practice to achieve
optimal conditions for the modification of polymers. The effect of
gamma irradiation on the crystalline structure of poly(vinylidene
fluoride) (PVDF) has been investigated using differential scanning
calorimetry (DSC) and X-ray diffraction techniques (XRD). Gamma
irradiation was carried out in atmosphere air with doses between 100
kGy at 3,000 kGy with a Co-60 source. In the melting thermogram of
the samples irradiated can be seen a bimodal melting endotherm is
detected with two melting temperature. The lower melting
temperature is attributed to melting of crystals originally present and
the higher melting peak due to melting of crystals reorganized upon
heat treatment. These results are consistent with those obtained by
XRD technique showing increasing crystallinity with increasing
irradiation dose, although the melting latent heat is decreasing.