Abstract: Mathematical programming has been applied to various
problems. For many actual problems, the assumption that the parameters
involved are deterministic known data is often unjustified. In
such cases, these data contain uncertainty and are thus represented
as random variables, since they represent information about the
future. Decision-making under uncertainty involves potential risk.
Stochastic programming is a commonly used method for optimization
under uncertainty. A stochastic programming problem with recourse
is referred to as a two-stage stochastic problem. In this study, we
consider a stochastic programming problem with simple integer
recourse in which the value of the recourse variable is restricted to a
multiple of a nonnegative integer. The algorithm of a dynamic slope
scaling procedure for solving this problem is developed by using a
property of the expected recourse function. Numerical experiments
demonstrate that the proposed algorithm is quite efficient. The
stochastic programming model defined in this paper is quite useful
for a variety of design and operational problems.
Abstract: This paper presents an optimized methodology to
folded cascode operational transconductance amplifier (OTA) design.
The design is done in different regions of operation, weak inversion,
strong inversion and moderate inversion using the gm/ID methodology
in order to optimize MOS transistor sizing.
Using 0.35μm CMOS process, the designed folded cascode OTA
achieves a DC gain of 77.5dB and a unity-gain frequency of 430MHz
in strong inversion mode. In moderate inversion mode, it has a 92dB
DC gain and provides a gain bandwidth product of around 69MHz.
The OTA circuit has a DC gain of 75.5dB and unity-gain frequency
limited to 19.14MHZ in weak inversion region.
Abstract: The purpose of this article applies the monthly final
energy yield and failure data of 202 PV systems installed in Taiwan to
analyze the PV operational performance and system availability. This
data is collected by Industrial Technology Research Institute through
manual records. Bad data detection and failure data estimation
approaches are proposed to guarantee the quality of the received
information. The performance ratio value and system availability are
then calculated and compared with those of other countries. It is
indicated that the average performance ratio of Taiwan-s PV systems
is 0.74 and the availability is 95.7%. These results are similar with
those of Germany, Switzerland, Italy and Japan.
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: The production of devices in nanoscale with specific
molecular rectifying function is one of the most significant goals in
state-of-art technology. In this work we show by ab initio quantum
mechanics calculations coupled with non-equilibrium Green
function, the design of an organic two-terminal device. These
molecular structures have molecular source and drain with several
bridge length (from five up to 11 double bonds). Our results are
consistent with significant features as a molecular rectifier and can be
raised up as: (a) it can be used as bi-directional symmetrical rectifier;
(b) two devices integrated in one (FET with one operational region,
and Thyristor thiristor); (c) Inherent stability due small intrinsic
capacitance under forward/reverse bias. We utilize a scheme for the
transport mechanism based on previous properties of ¤Ç bonds type
that can be successfully utilized to construct organic nanodevices.
Abstract: In recent years, sustainable supply chain management
(SSCM) has been widely researched in academic domain. However,
due to the traditional operational role and the complexity of supply
chain management in the cement industry, a relatively small amount
of research has been conducted on cement supply chain simulation
integrated with sustainability criteria. This paper analyses the cement
supply chain operations using the Push-Pull supply chain
frameworks, the Life Cycle Assessment (LCA) methodology; and
proposal integration approach, proposes three supply chain scenarios
based on Make-To-Stock (MTS), Pack-To-Order (PTO) and Grind-
To-Order (GTO) strategies. A Discrete-Event Simulation (DES)
model of SSCM is constructed using Arena software to implement
the three-target scenarios. We conclude with the simulation results
that (GTO) is the optimal supply chain strategy that demonstrates the
best economic, ecological and social performance in the cement
industry.
Abstract: In this paper a unified approach via block-pulse functions (BPFs) or shifted Legendre polynomials (SLPs) is presented to solve the linear-quadratic-Gaussian (LQG) control problem. Also a recursive algorithm is proposed to solve the above problem via BPFs. By using the elegant operational properties of orthogonal functions (BPFs or SLPs) these computationally attractive algorithms are developed. To demonstrate the validity of the proposed approaches a numerical example is included.
Abstract: Internet infrastructures in most places of the world
have been supported by the advancement of optical fiber technology,
most notably wavelength division multiplexing (WDM) system.
Optical technology by means of WDM system has revolutionized
long distance data transport and has resulted in high data capacity,
cost reductions, extremely low bit error rate, and operational
simplification of the overall Internet infrastructure. This paper
analyses and compares the system impairments, which occur at data
transmission rates of 2.5Gb/s and 10 Gb/s per wavelength channel in
our proposed optical WDM system for Internet infrastructure in
Tanzania. The results show that the data transmission rate of 2.5 Gb/s
has minimum system impairments compared with a rate of 10 Gb/s
per wavelength channel, and achieves a sufficient system
performance to provide a good Internet access service.
Abstract: There are two types of drought as conceptual drought
and operational drought. The three parameters as the beginning, the
end and the degree of severity of the drought can be identifying in
operational drought by average precipitation in the whole region. One
of the methods classified to measure drought is Reconnaissance
Drought Index (RDI). Evapotranspiration is calculated using
Penman-Monteith method by analyzing thirty nine years prolong
climatic data. The evapotranspiration is then utilized in RDI to
classify normalized and standardized RDI. These RDI classifications
led to what kind of drought faced in Bhavnagar region on 12 month
time scale basis. The comparison between actual drought conditions
and RDI method used to find out drought are also illustrated. It can
be concluded that the index results of drought in a particular year are
same in both methods but having different index values where as
severity remain same.
Abstract: The request for a sustainable development challenges
both managers and consumers to rethink habitual practices and
activities. While consumers are challenged to develop sustainable
consumption patterns, companies are asked to establish managerial
systems and structures considering economical, ecological, and social
issues. As this is in particular true for housing associations, this paper
aims first, at providing an understanding of sustainability strategy in
residential trade and industry (RTI) by identifying relevant facets of
this construct and second, at conceptually analyzing the impact of
sustainability strategy in RTI on operational efficiency and
performance of municipal housing companies. The author develops a
model of sustainability strategy in RTI and its effects and further,
sheds light in priorities for future research.
Abstract: Considering payload, reliability, security and operational lifetime as major constraints in transmission of images we put forward in this paper a steganographic technique implemented at the physical layer. We suggest transmission of Halftoned images (payload constraint) in wireless sensor networks to reduce the amount of transmitted data. For low power and interference limited applications Turbo codes provide suitable reliability. Ensuring security is one of the highest priorities in many sensor networks. The Turbo Code structure apart from providing forward error correction can be utilized to provide for encryption. We first consider the Halftoned image and then the method of embedding a block of data (called secret) in this Halftoned image during the turbo encoding process is presented. The small modifications required at the turbo decoder end to extract the embedded data are presented next. The implementation complexity and the degradation of the BER (bit error rate) in the Turbo based stego system are analyzed. Using some of the entropy based crypt analytic techniques we show that the strength of our Turbo based stego system approaches that found in the OTPs (one time pad).
Abstract: Policies that support entrepreneurship are keys to the
generation of new business. In Brazil, seed capital, installation of
technology parks, programs and zero interest financing, economic
subsidy as Program First Innovative Company (PRIME) are
examples of incentive policies. For the implementation of PRIME, in
particular the Brazilian Innovation Agency (FINEP) decentralized
operationalization so that business incubators could select innovative
projects. This paper analyzes the program PRIME Business Incubator
Center of the State of Sergipe (CISE) after calculating the mean and
standard deviation of the grades obtained by companies in the factors
of innovation, market potential, financial return economic, market
strategy and staff and application of the Mann-Whitney test.
Abstract: The paper outlines the drivers behind the movement
from products to solutions in the Hi-Tech Business-to-Business
markets. The paper lists out the challenges in enabling the
transformation from products to solutions and also attempts to explore
strategic and operational recommendations based on the authors-
factual experiences with Japanese Hi-tech manufacturing
organizations. Organizations in the Hi-Tech Business-to-Business
markets are increasingly being compelled to move to a solutions model
from the conventional products model. Despite the added complexity
of solutions, successful technology commercialization can be achieved
by making prudent choices in defining a relevant solutions model, by
backing the solution model through appropriate organizational design,
and by overhauling the new product development process and
supporting infrastructure.
Abstract: The Norwegian Military Academy (Army) has
initiated a project with the main ambition to explore possible avenues
to enhancing operational effectiveness through an increased use of
simulation-based training and exercises. Within a cost/benefit
framework, we discuss opportunities and limitations of vertical and
horizontal integration of the existing tactical training system. Vertical
integration implies expanding the existing training system to span the
full range of training from tactical level (platoon, company) to
command and staff level (battalion, brigade). Horizontal integration
means including other domains than army tactics and staff
procedures in the training, such as military ethics, foreign languages,
leadership and decision making. We discuss each of the integration
options with respect to purpose and content of training, "best
practice" for organising and conducting simulation-based training,
and suggest how to evaluate training procedures and measure
learning outcomes. We conclude by giving guidelines towards further
explorative work and possible implementation.
Abstract: The connection between solar activity and adverse phenomena in the Earth’s environment that can affect space and ground based technologies has spurred interest in Space Weather (SW) research. A great effort has been put on the development of suitable models that can provide advanced forecast of SW events. With the progress in computational technology, it is becoming possible to develop operational large scale physics based models which can incorporate the most important physical processes and domains of the Sun-Earth system. In order to enhance our SW prediction capabilities we are developing advanced numerical tools. With operational requirements in mind, our goal is to develop a modular simulation framework of propagation of the disturbances from the Sun through interplanetary space to the Earth. Here, we report and discuss on the development of coronal field and solar wind components for a large scale MHD code. The model for these components is based on a potential field source surface model and an empirical Wang-Sheeley-Arge solar wind relation.
Abstract: There was a high rate of corrosion in Pyrolysis
Gasoline Hydrogenation (PGH) unit of Arak Petrochemical Company
(ARPC), and it caused some operational problem in this plant. A
commercial chemical had been used as anti-corrosion in the
depentanizer column overhead in order to control the corrosion rate.
Injection of commercial corrosion inhibitor caused some
operational problems such as fouling in some heat exchangers. It was
proposed to replace this commercial material with another more
effective trouble free, and well-known additive by R&D and
operation specialists.
At first, the system was simulated by commercial simulation
software in electrolytic system to specify low pH points inside the
plant. After a very comprehensive study of the situation and technical
investigations ,ammonia / monoethanol amine solution was proposed
as neutralizer or corrosion inhibitor to be injected in a suitable point
of the plant. For this purpose, the depentanizer column and its
accessories system was simulated again in case of this solution
injection.
According to the simulation results, injection of new anticorrosion
substance has no any side effect on C5 cut product and
operating conditions of the column. The corrosion rate will be
cotrolled, if the pH remains at the range of 6.5 to 8 . Aactual plant
test run was also carried out by injection of ammonia / monoethanol
amine solution at the rate of 0.6 Kg/hr and the results of iron content
of water samples and corrosion test coupons confirmed the
simulation results.
Now, ammonia / monoethanol amine solution is injected to a
suitable pint inside the plant and corrosion rate has decreased
significantly.
Abstract: Complex systems are composed of several plain interacting independent entities. Interaction between these entities creates a unified behavior at the global level that cannot be predicted by examining the behavior of any single individual component of the system. In this paper we consider a welded frame of an automobile trailer as a real example of Complex Technical Systems, The purpose of this paper is to introduce a Statistical method for predicting the life cycle of complex technical systems. To organize gathering of primary data for modeling the life cycle of complex technical systems an “Automobile Trailer Frame" were used as a prototype in this research. The prototype represents a welded structure of several pieces. Both information flows underwent a computerized analysis and classification for the acquisition of final results to reach final recommendations for improving the trailers structure and their operational conditions.
Abstract: Environmental awareness and the recent
environmental policies have forced many electric utilities to
restructure their operational practices to account for their emission
impacts. One way to accomplish this is by reformulating the
traditional economic dispatch problem such that emission effects are
included in the mathematical model. This paper presents a Particle
Swarm Optimization (PSO) algorithm to solve the Economic-
Emission Dispatch problem (EED) which gained recent attention due
to the deregulation of the power industry and strict environmental
regulations. The problem is formulated as a multi-objective one with
two competing functions, namely economic cost and emission
functions, subject to different constraints. The inequality constraints
considered are the generating unit capacity limits while the equality
constraint is generation-demand balance. A novel equality constraint
handling mechanism is proposed in this paper. PSO algorithm is
tested on a 30-bus standard test system. Results obtained show that
PSO algorithm has a great potential in handling multi-objective
optimization problems and is capable of capturing Pareto optimal
solution set under different loading conditions.
Abstract: With high speed vessels getting ever more sophisti-cated, travelling at higher and higher speeds and operating in With high speed vessels getting ever more sophisticated,
travelling at higher and higher speeds and operating in areas of
high maritime traffic density, training becomes of the highest priority
to ensure that safety levels are maintained, and risks are adequately
mitigated. Training onboard the actual craft on the actual route still
remains the most effective way for crews to gain experience. However,
operational experience and incidents during the last 10 years
demonstrate the need for supplementary training whether in the area
of simulation or man to man, man/ machine interaction. Training and
familiarisation of the crew is the most important aspect in preventing
incidents. The use of simulator, computer and web based training
systems in conjunction with onboard training focusing on critical
situations will improve the man machine interaction and thereby
reduce the risk of accidents. Today, both ship simulator and bridge
teamwork courses are now becoming the norm in order to improve
further emergency response and crisis management skills. One of the
main causes of accidents is the human factor. An efficient way to
reduce human errors is to provide high-quality training to the personnel
and to select the navigators carefully.areas of high maritime traffic density, training becomes of the highest priority to ensure that safety levels are maintained, and risks are adequately mitigated. Training onboard the actual craft on the actual route still remains the most effective way for crews to gain experience. How-ever, operational experience and incidents during the last 10 years demonstrate the need for supplementary training whether in the area of simulation or man to man, man/ machine interaction. Training and familiarisation of the crew is the most important aspect in preventing incidents. The use of simulator, computer and web based training systems in conjunction with onboard training focusing on critical situations will improve the man machine interaction and thereby reduce the risk of accidents. Today, both ship simulator and bridge teamwork courses are now becoming the norm in order to improve further emergency response and crisis management skills. One of the main causes of accidents is the human factor. An efficient way to reduce human errors is to provide high-quality training to the person-nel and to select the navigators carefully. KeywordsCBT - WBT systems, Human factors.
Abstract: New generation mobile communication networks have
the ability of supporting triple play. In order that, Orthogonal
Frequency Division Multiplexing (OFDM) access techniques have
been chosen to enlarge the system ability for high data rates
networks. Many of cross-layer modeling and optimization schemes
for Quality of Service (QoS) and capacity of downlink multiuser
OFDM system were proposed. In this paper, the Maximum Weighted
Capacity (MWC) based resource allocation at the Physical (PHY)
layer is used. This resource allocation scheme provides a much better
QoS than the previous resource allocation schemes, while
maintaining the highest or nearly highest capacity and costing similar
complexity. In addition, the Delay Satisfaction (DS) scheduling at the
Medium Access Control (MAC) layer, which allows more than one
connection to be served in each slot is used. This scheduling
technique is more efficient than conventional scheduling to
investigate both of the number of users as well as the number of
subcarriers against system capacity. The system will be optimized for
different operational environments: the outdoor deployment scenarios
as well as the indoor deployment scenarios are investigated and also
for different channel models. In addition, effective capacity approach
[1] is used not only for providing QoS for different mobile users, but
also to increase the total wireless network's throughput.