Abstract: Simulation is a very powerful method used for highperformance
and high-quality design in distributed system, and now
maybe the only one, considering the heterogeneity, complexity and
cost of distributed systems. In Grid environments, foe example, it is
hard and even impossible to perform scheduler performance
evaluation in a repeatable and controllable manner as resources and
users are distributed across multiple organizations with their own
policies. In addition, Grid test-beds are limited and creating an
adequately-sized test-bed is expensive and time consuming.
Scalability, reliability and fault-tolerance become important
requirements for distributed systems in order to support distributed
computation. A distributed system with such characteristics is called
dependable. Large environments, like Cloud, offer unique
advantages, such as low cost, dependability and satisfy QoS for all
users. Resource management in large environments address
performant scheduling algorithm guided by QoS constrains. This
paper presents the performance evaluation of scheduling heuristics
guided by different optimization criteria. The algorithms for
distributed scheduling are analyzed in order to satisfy users
constrains considering in the same time independent capabilities of
resources. This analysis acts like a profiling step for algorithm
calibration. The performance evaluation is based on simulation. The
simulator is MONARC, a powerful tool for large scale distributed
systems simulation. The novelty of this paper consists in synthetic
analysis results that offer guidelines for scheduler service
configuration and sustain the empirical-based decision. The results
could be used in decisions regarding optimizations to existing Grid
DAG Scheduling and for selecting the proper algorithm for DAG
scheduling in various actual situations.
Abstract: This study describes a micro device integrated with
multi-chamber for polymerase chain reaction (PCR) with different
annealing temperatures. The device consists of the reaction
polydimethylsiloxane (PDMS) chip, a cover glass chip, and is
equipped with cartridge heaters, fans, and thermocouples for
temperature control. In this prototype, commercial software is utilized
to determine the geometric and operational parameters those are
responsible for creating the denaturation, annealing, and extension
temperatures within the chip. Two cartridge heaters are placed at two
sides of the chip and maintained at two different temperatures to
achieve a thermal gradient on the chip during the annealing step. The
temperatures on the chip surface are measured via an infrared imager.
Some thermocouples inserted into the reaction chambers are used to
obtain the transient temperature profiles of the reaction chambers
during several thermal cycles. The experimental temperatures
compared to the simulated results show a similar trend. This work
should be interesting to persons involved in the high-temperature
based reactions and genomics or cell analysis.
Abstract: This research tries to analyze the role that knowledge
about foreign markets has in increasing firms- exports in clustered
spaces. We consider two interrelated sources of knowledge: firms-
direct experience and indirect experience from other clustered firms –
export externalities. In particular, it is proposed that firms would
improve their export performance by accessing to export externalities
if they have some previous direct experience that allows them to
identify, understand and exploit them. Also, we propose that this
positive influence of previous direct experience on export
externalities keeps only up to a point, where it becomes negative,
creating an inverted “U" shape. Empirical evidence gathered among
wine producers located in La Rioja tends to confirm that firms enjoy
of export externalities if they have export experience along several
years and countries increase their export performance. While this
relationship becomes less relevant as they develop a higher
experience, we could not confirm the existence of a curvilinear
relationship in their influence on export externalities and export
performance.
Abstract: This article deals with the conceptual modeling under uncertainty. First, the division of information systems with their definition will be described, focusing on those where the construction of a conceptual model is suitable for the design of future information system database. Furthermore, the disadvantages of the traditional approach in creating a conceptual model and database design will be analyzed. A comprehensive methodology for the creation of a conceptual model based on analysis of client requirements and the selection of a suitable domain model is proposed here. This article presents the expert system used for the construction of a conceptual model and is a suitable tool for database designers to create a conceptual model.
Abstract: Auckland has a temperate climate with comfortable
warm, dry summers and mild, wet winters. An Auckland school
normally does not need air conditioning for cooling during the
summer and only need heating during the winter. The space hating
energy is the major portion of winter school energy consumption and
the winter energy consumption is major portion of annual school
energy consumption. School building thermal design should focus
on the winter thermal performance for reducing the space heating
energy. A number of Auckland schools- design data and energy
consumption data are used for this study. This pilot study
investigates the relationships between their energy consumption data
and school building design data to improve future school design for
energy efficiency.
Abstract: Manufacturing components of fiber-reinforced
thermoplastics requires three steps: heating the matrix, forming and
consolidation of the composite and terminal cooling the matrix. For
the heating process a pre-determined temperature distribution through
the layers and the thickness of the pre-consolidated sheets is
recommended to enable forming mechanism. Thus, a design for the
heating process for forming composites with thermoplastic matrices
is necessary. To obtain a constant temperature through thickness and
width of the sheet, the heating process was analyzed by the help of
the finite element method. The simulation models were validated by
experiments with resistance thermometers as well as with an infrared
camera. Based on the finite element simulation, heating methods for
infrared radiators have been developed. Using the numeric
simulation many iteration loops are required to determine the process
parameters. Hence, the initiation of a model for calculating relevant
process parameters started applying regression functions.
Abstract: This paper presents the experimental as well as the
simulated performance studies on the transcritical CO2 heat pumps
for simultaneous water cooling and heating; effects of water mass
flow rates and water inlet temperatures of both evaporator and gas
cooler on the cooling and heating capacities, system COP and water
outlets temperatures are investigated. Study shows that both the
water mass flow rate and inlet temperature have significant effect on
system performances. Test results show that the effect of evaporator
water mass flow rate on the system performances and water outlet
temperatures is more pronounced (COP increases 0.6 for 1 kg/min)
compared to the gas cooler water mass flow rate (COP increases 0.4
for 1 kg/min) and the effect of gas cooler water inlet temperature is
more significant (COP decreases 0.48 for given ranges) compared to
the evaporator water inlet temperature (COP increases 0.43 for given
ranges). Comparisons of experimental values with simulated results
show the maximum deviation of 5% for cooling capacity, 10% for
heating capacity, 16% for system COP. This study offers useful
guidelines for selecting appropriate water mass flow rate to obtain
required system performance.
Abstract: Educational institutions are increasingly exploring the affordances of 3D virtual worlds for instruction and research, but few studies have been done to document current practices and uses of this emerging technology. This observational survey examines the virtual presences of 170 accredited educational institutions found in one such 3D virtual world called Second Life®, created by San- Francisco based Linden Lab®. The study focuses on what educational institutions look like in this virtual environment, the types of spaces educational institutions are creating or simulating, and what types of activities are being conducted.
Abstract: The 15-a-side Fiji rugby team trains well in preparations for any rugby competition but rarely performs to expectations. In order to help the Fiji local based rugby players to identify some key basic areas in improving their performance, a series of workshops were conducted to assess their nutritional status and dietary habits in relation to energy demand during rugby matches. The nutrition workshop included the administration of questionnaires to 19 local based rugby players, requesting the following information: usual food intakes, training camp food intakes, carbohydrate loading, pre-game meals and post-game meals. The study revealed that poor eating habits of the players resulted in the low carbohydrate intake, which may have contributed to increase levels of fatigue leading to loss of stamina even before the second half of the game. It appears that the diet of most 15-a-side players does not provide enough energy to enable them to last the full eightyminutes of the game.
Abstract: Vibration characteristics of subcooled flow boiling on
thin and long structures such as a heating rod were recently
investigated by the author. The results show that the intensity of the
subcooled boiling-induced vibration (SBIV) was influenced strongly
by the conditions of the subcooling temperature, linear power density
and flow velocity. Implosive bubble formation and collapse are the
main nature of subcooled boiling, and their behaviors are the only
sources to originate from SBIV. Therefore, in order to explain the
phenomenon of SBIV, it is essential to obtain reliable information
about bubble behavior in subcooled boiling conditions. This was
investigated at different conditions of coolant subcooling
temperatures of 25 to 75°C, coolant flow velocities of 0.16 to
0.53m/s, and linear power densities of 100 to 600 W/cm. High speed
photography at 13,500 frames per second was performed at these
conditions. The results show that even at the highest subcooling
condition, the absolute majority of bubbles collapse very close to the
surface after detaching from the heating surface. Based on these
observations, a simple model of surface tension and momentum
change is introduced to offer a rough quantitative estimate of the
force exerted on the heating surface during the bubble ebullition. The
formation of a typical bubble in subcooled boiling is predicted to
exert an excitation force in the order of 10-4 N.
Abstract: Axial Flux Permanent Magnet (AFPM) Machines require effective cooling due to their high power density. The detrimental effects of overheating such as degradation of the insulation materials, magnets demagnetization, and increase of Joule losses are well known. This paper describes the CFD simulations performed on a test rig model of an air cooled Axial Flux Permanent Magnet (AFPM) generator built at Durham University to identify the temperatures and heat transfer coefficient on the stator. The Reynolds Averaged Navier-Stokes and the Energy equations are solved and the flow pattern and heat transfer developing inside the machine are described. The Nusselt number on the stator surfaces has been found. The dependency of the heat transfer on the flow field is described temperature field obtained. Tests on an experimental are undergoing in order to validate the CFD results.
Abstract: Due to the low heavy metal concentrations, the
bottom ash from a 32 MW municipal district heating plant was
determined to be a potential forest fertilizer as such. However,
additional Ca would be needed, because its Ca concentration of 1.9-
% (d.w.) was lower than the statutory Finnish minimum limit value
of 6.0-% (d.w.) for Ca in forest fertilizer. Due to the elevated As
concentration (53.0 mg/kg; d.w.) in the fly ash from the 32 MW
municipal district heating plant, and Cr concentration (620 mg/kg;
d.w.) in the ash fraction (i.e. mixture of the bottom ash and fly ash)
from the 6 MW municipal district heating plant, which exceed the
limit values of 30 mg/kg (d.w.) and 300 mg/kg (d.w.) for As and Cr,
respectively, these residues are not suitable as forest fertilizers.
Although these ash fractions cannot be used as a forest fertilizer as
such, they can be used for the landscaping of landfills or in industrial
and other areas that are closed to the public. However, an
environmental permit is then needed.
Abstract: Simulation model is an easy way to build up models
to represent real life scenarios, to identify bottlenecks and to enhance
system performance. Using a valid simulation model may give
several advantages in creating better manufacturing design in order to
improve the system performances. This paper presents result of
implementing a simulation model to design hard disk drive
manufacturing process by applying line balancing to improve both
productivity and quality of hard disk drive process. The line balance
efficiency showed 86% decrease in work in process, output was
increased by an average of 80%, average time in the system was
decreased 86% and waiting time was decreased 90%.
Abstract: In this article has been analyzed Kazakhstani
experience in organizing the system after the institute of higher education, legislative-regulative assurance of master preparation, and
statistic data in the republic. Have been the features of projecting the master programs, a condition of realization of studying credit system, have been analyzed the technologies of research teaching masters. In
conclusion have been given some recommendation on creating personal-oriented environment of research teaching masters.
Abstract: For scores of years now, several microfinance
organizations, non governmental organizations and other welfare
organizations have, with a view to aiding the progress of
communities rooted in poverty have been focusing on creating
microentrepreneurs, besides taking several other measures. In recent
times, business corporations have joined forces to combat poverty by
taking up microenterprise development. Hindustan Unilever Limited
(HUL), the Indian subsidiary of Unilever Limited exemplifies this
through its Project Shakti. The company through the Project creates
rural women entrepreneurs by making them direct to home sales
distributors of its products in villages that have thus far been ignored
by multinational corporations. The members participating in Project
Shakti are largely self help group members. The paper focuses on
assessing the impact made by the company on the members engaged
in Project Shakti. The analysis involves use of quantitative methods
to study the effect of Project Shakti on those self help group
members engaged in Project Shakti and those not engaged with
Project Shakti. Path analysis has been used to study the impact made
on those members engaged in Project Shakti. Significant differences
were observed on fronts of entrepreneurial development, economic
empowerment and social empowerment between members associated
with Project Shakti and those not associated with Project Shakti.
Path analysis demonstrated that involvement in Project Shakti led to
entrepreneurial development resulting in economic empowerment
that in turn led to social empowerment and that these three elements
independently induced a feeling of privilege in the women for being
associated with the Project.
Abstract: Laboratory experiments have been performed to investigate photocatalytic detoxification by using TiO2 photocatalyst for treating dairy effluent. Various operational parameters such as catalyst concentration, initial concentration, angle of tilt of solar flat plate reactor and flow rate were investigated. Results indicated that the photocatalytic detoxification process can efficiently treat dairy effluent. Experimental runs with dairy wastewater can be used to identify the optimum operational parameters to perform wastewater degradation on large scale for recycling purpose. Also effect of two different types of reactors on degradation process was analyzed.
Abstract: Internet access is a vital part of the modern world and an important tool in the education of our children. It is present in schools, homes and even shopping malls. Mastering the use of the internet is likely to be an important skill for those entering the job markets of the future. An internet user can be anyone he or she wants to be in an online chat room, or play thrilling and challenging games against other players from all corners of the globe. It seems at present time (or near future) for many people relationships in the real world may be neglected as those in the virtual world increase in importance. Internet is provided a fast mode of transportation caused freedom from family bonds and mixing with different cultures and new communities. This research is an attempt to study effect of Internet on Social capital. For this purpose a survey technique on the sample size amounted 168 students of Payame Noor University of Kermanshah city in country of Iran were considered. Degree of social capital is moderate. With the help of the Multi-variable Regression, variables of Iranian message attractive, Interest to internet with effect of positive and variable Creating a cordial atmosphere with negative effect be significant.
Abstract: The investigation results of high-density hydrogen
heating by high-current electric arc are presented at initial pressure
from 5 MPa to 160 MPa with current amplitude up to 1.6 MA and
current rate of rise 109-1011 A/s. When changing the initial pressure
and current rate of rise, channel temperature varies from several
electronvolts to hundreds electronvolts. Arc channel radius is several
millimeters. But the radius of the discharge chamber greater than the
radius of the arc channel on approximately order of magnitude. High
efficiency of gas heating is caused by radiation absorption of
hydrogen surrounding the arc. Current channel consist from vapor of
the initiating wire. At current rate of rise of 109 A/s and relatively
small current amplitude gas heating occurs due to radiation
absorption in the band transparency of hydrogen by the wire vapours
with photon energies less than 13.6 eV. At current rate of rise of
1011 A/s gas heating is due to hydrogen absorption of soft X-rays
from discharge channel.
Abstract: Development of knowledge based society carries multiple challenges to the higher education system. Some of the challenges laid before the higher education sector of countries which aspire to become knowledge based societies are: the entrepreneurial leadership of the higher education institutions, finding new sources of financing in order to minimize dependence on public resources, creating connections with the labor market, commercial utilization of R&D results, promotion of innovations as well as the overall promotion of science excellence relevant to the economic sector. Within a framework of this paper and its main subject of research, the challenge which is being put before the higher education institutions is an effort of establishing regional mission of higher education through the open collaboration with regional key factors, both private and public. Development of the mentioned collaboration and its contribution to the overall regional development in Croatia is the main subject of empirical research in this paper.
Abstract: This article deals with the numerical simulation of the
floor heating convector in 3D. Presented convector can operate in
two modes – cooling mode and heating mode. This initial numerical
simulation is focused on cooling mode of the convector. Models with
different temperature of the fins are compared and three various
shapes of the fins are examined as well. The objective of the work is
to predict air flow and heat transfer inside convector for further
optimalization of these devices. For the numerical simulation was
used commercial software Ansys Fluent.