Abstract: Worldwide Interoperability for Microwave Access (WiMAX) became one of the most challenging issues, since it was responsible for distributing available resources of the network among all users this leaded to the demand of constructing and designing high efficient scheduling algorithms in order to improve the network utilization, to increase the network throughput, and to minimize the end-to-end delay. In this study, the proposed algorithm focuses on an efficient mechanism to serve non_real time traffic in congested networks by considering channel status.
Abstract: This paper involves a study of the heavy metal pollution of the soils around one of cement plants in Libya called Suk-Alkhameas and surrounding urban areas caused by cement kiln dust (CKD) emitted. Samples of soil was collected from sites at four directions around the cement factory at distances 250m, 1000m, and 3000m from the factory and at (0-10)cm deep in the soil. These samples are analyzed for Fe (iii), Zn(ii), and Pb (ii) as major pollutants. These values are compared with soils at 25 Km distances from the factory as a reference or control samples. The results show that the concentration of Fe ions in the surface soil was within the acceptable range of 1000ppm. However, for Zn and Pb ions the concentrations at the east and north sides of the factory were found six fold higher than the benchmark level. This high value was attributed to the wind which blows usually from south to north and from west to east. This work includes an investigation of the adsorption isotherms and adsorption efficiency of CKD as adsorbent of heavy metal ions (Fe (iii), Zn(ii), and Pb(ii)) from the polluted soils of Suk-Alkameas city. The investigation was conducted in batch and fixed bed column flow technique. The adsorption efficiency of the studied heavy metals ions removals onto CKD depends on the pH of the solution. The optimum pH values are found to be in the ranges of 8-10 and decreases at lower pH values. The removal efficiency of these heavy metals ions ranged from 93% for Pb, 94% for Zn, and 98% for Fe ions for 10 g.l-1 adsorbent concentration. The maximum removal efficiency of these ions was achieved at 50-60 minutes contact times at which equilibrium is reached. Fixed bed column experimental measurements are also made to evaluate CKD as an adsorbent for the heavy metals. Results obtained are with good agreement with Langmuir and Drachsal assumption of multilayer formation on the adsorbent surface.
Abstract: The selection of control strategy depends on the converters of the drive including power, speed, performance and the possible system costs. A number of attempts were therefore made in recent times to develop novel power electronic converter structures for SRM drives, based on the utilization. Many of the converters with variable speed drives have no input power factor correction circuits. This results in harmonic pollution of the utility supply, which should be avoided. The effect of power factor variation in terms of harmonic content is also analyzed in this study. The proposed topologies were simulated using MATLAB / Simulink software package and the results are obtained.
Abstract: Microcirculatory dysfunction is very common in sepsis and may results in organ failure and increased risk of death. Analyzing oxygen utilization can potentially assess microcirculation function of an individual. In this study, a modified pulse oximeter is used to extract information signals due to absorption of red (R) and infrared (IR) light. IR and R signal are related to the overall blood volume and reduced hemoglobin, respectively. Differences between these two signals thus represent the amount of oxygenated hemoglobin. Avascular occlusion test has been conducted on healthy individuals to validate the pulse oximeter concept. In this test, both R and IR signals rapidly changed according to the occlusion process. The pulse oximeter concept presented is capable of extracting valuable information to assess microcirculation condition. Implementing this concept on ICU patients has the potential to aid sepsis diagnosis and provide more accurate tracking of patient state and sepsis status.
Abstract: This paper focuses on the operational and strategic planning decisions related to the quayside of container terminals. We introduce an integrated operational research (OR) and system dynamics (SD) approach to solve the Berth Allocation Problem (BAP) and the Quay Crane Assignment Problem (QCAP). A BAP-QCAP optimization modeling approach which considers practical aspects not studied before in the integration of BAP and QCAP is discussed. A conceptual SD model is developed to determine the long-term effect of optimization on the system behavior factors like resource utilization, attractiveness to port, number of incoming vessels to port and port profits. The framework can be used for improving the operational efficiency of container terminals and providing a strategic view after applying optimization.
Abstract: The television multiplex has reserved capacity and therefore we can use only limited number of videos for propagation of it. Appropriate composition of the multiplex has a major impact on how many videos is spread by multiplex. Therefore in this paper is designed a simple algorithm to optimize capacity utilization multiplex. Significant impact on the number of programs in the multiplex has also the fact from which programs is composed. Content of multiplex can be movies, news, sport, animated stories, documentaries, etc. These types have their own specific characteristics that affect their resulting data stream. In this paper is also done an impact analysis of the composition of the multiplex to use its capacity by video content.
Abstract: Modern management in most fields is performance based; both planning and implementation of maintenance and operational activities are driven by appropriately defined performance indicators. Continuous real-time data collection for management is becoming feasible due to technological advancements. Outdated and insufficient input data may result in incorrect decisions. When using deterministic models the uncertainty of the object state is not visible thus applying the deterministic models are more likely to give false diagnosis. Constructing structured probabilistic models of the performance indicators taking into consideration the surrounding indicator environment enables to estimate the trustworthiness of the indicator values. It also assists to fill gaps in data to improve the quality of the performance analysis and management decisions. In this paper authors discuss the application of probabilistic graphical models in the road performance measurement and propose a high-level conceptual model that enables analyzing and predicting more precisely future pavement deterioration based on road utilization.
Abstract: Electrification is a complex process and governed by various parameters. Modeling of power plant’s target efficiency or target heat rate is often formulated and compared with the actual values. This comparison not only implies the performance of the power plant but also reflects the energy losses possibly inherited in some of related equipment and processes. The current modeling of Coal-fired Mae Moh power plant was formulated at the first commissioning. Some of equipments were replaced due to its life time. Relatively outdated for 20 years, the utilization of the model is not accomplished. This work has focused on the development of the performance analysis model of aforementioned power plant according to the most updated and current working conditions. The model is more appropriate and shows accuracy in its analysis. Losses are detected and measures are introduced such that reduction in energy consumption, related cost, and also environment impacts can be anticipated.
Abstract: The purpose of this paper is to simulate the production process of a metal stamping industry and to evaluate the utilization of the production line by using ARENA simulation software. The process time and the standard time for each process of the production line is obtained from data given by the company management. Other data are collected through direct observation of the line. There are three work stations performing ten different types of processes in order to produce a single product type. Arena simulation model is then developed based on the collected data. Verification and validation are done to the Arena model, and finally the result of Arena simulation can be analyzed. It is found that utilization at each workstation will increase if batch size is increased although throughput rate remains/is kept constant. This study is very useful for the company because the company needs to improve the efficiency and utilization of its production lines.
Abstract: Themain goal of this article is to find efficient
methods for elemental and molecular analysis of living
microorganisms (algae) under defined environmental conditions and
cultivation processes. The overall knowledge of chemical
composition is obtained utilizing laser-based techniques, Laser-
Induced Breakdown Spectroscopy (LIBS) for acquiring information
about elemental composition and Raman Spectroscopy for gaining
molecular information, respectively. Algal cells were suspended in
liquid media and characterized using their spectra. Results obtained
employing LIBS and Raman Spectroscopy techniques will help to
elucidate algae biology (nutrition dynamics depending on cultivation
conditions) and to identify algal strains, which have the potential for
applications in metal-ion absorption (bioremediation) and biofuel
industry. Moreover, bioremediation can be readily combined with
production of 3rd generation biofuels. In order to use algae for
efficient fuel production, the optimal cultivation parameters have to
be determinedleading to high production of oil in selected
cellswithout significant inhibition of the photosynthetic activity and
the culture growth rate, e.g. it is necessary to distinguish conditions
for algal strain containing high amount of higher unsaturated fatty
acids. Measurements employing LIBS and Raman Spectroscopy were
utilized in order to give information about alga Trachydiscusminutus
with emphasis on the amount of the lipid content inside the algal cell
and the ability of algae to withdraw nutrients from its environment
and bioremediation (elemental composition), respectively. This
article can serve as the reference for further efforts in describing
complete chemical composition of algal samples employing laserablation
techniques.
Abstract: This study was an investigation on the suitability of Lahar/HDPE composite as a primary material for low-cost smallscale biogas digesters. While sources of raw materials for biogas are abundant in the Philippines, cost of the technology has made the widespread utilization of this resource an indefinite proposition. Aside from capital economics, another problem arises with space requirements of current digester designs. These problems may be simultaneously addressed by fabricating digesters on a smaller, household scale to reach a wider market, and to use materials that may accommodate optimization of overall design and fabrication cost without sacrificing operational efficiency. This study involved actual fabrication of the Lahar/HDPE composite at varying composition and geometry, subsequent mechanical and thermal characterization, and implementation of Statistical Analysis to find intrinsic relationships between variables. From the results, Lahar/HDPE composite was found to be feasible for use as digester material from both mechanical and economic standpoints.
Abstract: According to the increasing utilization in power system, the transmission lines and power plants often operate in stability boundary and system probably lose its stable condition by over loading or occurring disturbance. According to the reasons that are mentioned, the prediction and recognition of voltage instability in power system has particular importance and it makes the network security stronger.This paper, by considering of power system contingencies based on the effects of them on Mega Watt Margin (MWM) and maximum loading point is focused in order to analyse the static voltage stability using continuation power flow method. The study has been carried out on IEEE 14-Bus Test System using Matlab and Psat softwares and results are presented.
Abstract: Time-Cost Optimization "TCO" is one of the greatest challenges in construction project planning and control, since the optimization of either time or cost, would usually be at the expense of the other. Since there is a hidden trade-off relationship between project and cost, it might be difficult to predict whether the total cost would increase or decrease as a result of the schedule compression. Recently third dimension in trade-off analysis is taken into consideration that is quality of the projects. Few of the existing algorithms are applied in a case of construction project with threedimensional trade-off analysis, Time-Cost-Quality relationships. The objective of this paper is to presents the development of a practical software system; that named Automatic Multi-objective Typical Construction Resource Optimization System "AMTCROS". This system incorporates the basic concepts of Line Of Balance "LOB" and Critical Path Method "CPM" in a multi-objective Genetic Algorithms "GAs" model. The main objective of this system is to provide a practical support for typical construction planners who need to optimize resource utilization in order to minimize project cost and duration while maximizing its quality simultaneously. The application of these research developments in planning the typical construction projects holds a strong promise to: 1) Increase the efficiency of resource use in typical construction projects; 2) Reduce construction duration period; 3) Minimize construction cost (direct cost plus indirect cost); and 4) Improve the quality of newly construction projects. A general description of the proposed software for the Time-Cost-Quality Trade-Off "TCQTO" is presented. The main inputs and outputs of the proposed software are outlined. The main subroutines and the inference engine of this software are detailed. The complexity analysis of the software is discussed. In addition, the verification, and complexity of the proposed software are proved and tested using a real case study.
Abstract: In all industries which are related to heat, suitable
thermal ranges are defined for each device to operate well.
Consideration of these limits requires a thermal control unit beside
the main system. The Satellite Thermal Control Unit exploits from
different methods and facilities individually or mixed. For enhancing
heat transfer between primary surface and the environment,
utilization of radiating extended surfaces are common. Especially for
large temperature differences; variable thermal conductivity has a
strong effect on performance of such a surface .In most literatures,
thermo-physical properties, such as thermal conductivity, are
assumed as constant. However, in some recent researches the
variation of these parameters is considered. This may be helpful for
the evaluation of fin-s temperature distribution in relatively large
temperature differences. A new method is introduced to evaluate
temperature-dependent thermal conductivity values. The finite
volume method is employed to simulate numerically the temperature
distribution in a space radiating fin. The present modeling is carried
out for Aluminum as fin material and compared with previous
method. The present results are also compared with those of two
other analytical methods and good agreement is shown.
Abstract: This paper presents a case study that uses processoriented
simulation to identify bottlenecks in the service delivery
system in an emergency department of a hospital in the United Arab
Emirates. Using results of the simulation, response surface models
were developed to explain patient waiting time and the total time
patients spend in the hospital system. Results of the study could be
used as a service improvement tool to help hospital management in
improving patient throughput and service quality in the hospital
system.
Abstract: In this paper, we study statistical multiplexing of VBR
video in ATM networks. ATM promises to provide high speed realtime
multi-point to central video transmission for telemedicine
applications in rural hospitals and in emergency medical services.
Video coders are known to produce variable bit rate (VBR) signals
and the effects of aggregating these VBR signals need to be
determined in order to design a telemedicine network infrastructure
capable of carrying these signals. We first model the VBR video
signal and simulate it using a generic continuous-data autoregressive
(AR) scheme. We carry out the queueing analysis by the Fluid
Approximation Model (FAM) and the Markov Modulated Poisson
Process (MMPP). The study has shown a trade off: multiplexing
VBR signals reduces burstiness and improves resource utilization,
however, the buffer size needs to be increased with an associated
economic cost. We also show that the MMPP model and the Fluid
Approximation model fit best, respectively, the cell region and the
burst region. Therefore, a hybrid MMPP and FAM completely
characterizes the overall performance of the ATM statistical
multiplexer. The ramifications of this technology are clear: speed,
reliability (lower loss rate and jitter), and increased capacity in video
transmission for telemedicine. With migration to full IP-based
networks still a long way to achieving both high speed and high
quality of service, the proposed ATM architecture will remain of
significant use for telemedicine.
Abstract: In today-s world, the efficient utilization of wood
resources comes more and more to the mind of forest owners. It is a
very complex challenge to ensure an efficient harvest of the wood
resources. This is one of the scopes the project “Virtual Forest II"
addresses. Its core is a database with data about forests containing
approximately 260 million trees located in North Rhine-Westphalia
(NRW). Based on this data, tree growth simulations and wood
mobilization simulations can be conducted. This paper focuses on the
latter. It describes a discrete-event-simulation with an attached 3-D
real time visualization which simulates timber harvest using trees
from the database with different crop resources. This simulation can
be displayed in 3-D to show the progress of the wood crop. All the
data gathered during the simulation is presented as a detailed
summary afterwards. This summary includes cost-benefit
calculations and can be compared to those of previous runs to
optimize the financial outcome of the timber harvest by exchanging
crop resources or modifying their parameters.
Abstract: Cities expansion, urban travels increase, the
technology development, the automobile price cheapen, and the
families' income ascending cause the considerable increase in
automobile numbers of the city. This fact has led to the traffic
creation and the automobile parking site shortage in the city. Also in
Esfahan metropolis, the parking lots shortage has been the great
problem of this town; in addition, in designing and constructing of
the parking sites the traditional methods are utilized which do not
have a reasonable and optimized usage of the valuable urban lands. In
this article, by introducing the prefabricate mechanized parking
system which is inexpensive, simple and quick, and occupies very
small space, therefore provides the high content of parking site for
the cities, we can eliminate the parking space shortage difficulty of
the cities. The achieved results of this research represent that an
optimized utilization of the existent urban spaces for parking site
construction has not been accomplished. By employing the new
parking site technologies such as mechanization categorized parking
sites and the capacity prefabricate mechanized of each parking space
have become 8 multiples; in this case, the valuable urban lands can
be used in an optimized way.
Abstract: Cattle manure and mineral fertilizers are two source
of Nitrogen, which can affect the growth and quantity of potato. In
this research the effects of the use of cattle manure (5, 10, 15 and 20
ton ha-1), Nitrogen fertilizer (50, 100 and 150 kg N ha-1) and their
interaction on potato growth were evaluated during field
experiments in 2008 with the help of Randomized Complete Block
(RCB) with the factorial arrangement of three experimental
replications in Iran. At the 75 th day after emergence, dry weight of
Shoots, leaf area index (LAI) and plant height were recorded. Results
showed that, dry weight of Shoots, LAI and plant height increased
linearly and very significantly in response to the application of
manure and Nitrogen fertilizer. While the interaction between
manure and Nitrogen fertilizer just on the LAI and plant height was
significant, somehow the maximum amount of plant height( 73 cm)
was obtained by using 150 kg Nitrogen + 15 tons of manure per
hectare, and maximum LAI ( 5.36) was obtained by using 150 kg
Nitrogen + 20 tons of manure per hectare. Also in this experiment
maximum tuber yield (36.8 tons ha-1) was obtained by the utilization
of 150 kg Nitrogen per hectare + 20 tons manure.
Abstract: In this paper, we introduce an mobile agent framework
with proactive load balancing for ambient intelligence (AmI) environments.
One of the main obstacles of AmI is the scalability in
which the openness of AmI environment introduces dynamic resource
requirements on agencies. To mediate this scalability problem, our
framework proposes a load balancing module to proactively analyze
the resource consumption of network bandwidth and preferred agencies
to suggest the optimal communication method to its user. The
framework generally formulates an AmI environment that consists
of three main components: (1) mobile devices, (2) hosts or agencies,
and (3) directory service center (DSC). A preliminary implementation
was conducted with NetLogo and the experimental results show that
the proposed approach provides enhanced system performance by
minimizing the network utilization to provide users with responsive
services.