Abstract: With the drastically growth in optical communication
technology, a lossless, low-crosstalk and multifunction optical switch
is most desirable for large-scale photonic network. To realize such a
switch, we have introduced the new architecture of optical switch
that embedded many functions on single device. The asymmetrical
architecture of OXADM consists of 3 parts; selective port, add/drop
operation, and path routing. Selective port permits only the interest
wavelength pass through and acts as a filter. While add and drop
function can be implemented in second part of OXADM architecture.
The signals can then be re-routed to any output port or/and perform
an accumulation function which multiplex all signals onto single path
and then exit to any interest output port. This will be done by path
routing operation. The unique features offered by OXADM has
extended its application to Fiber to-the Home Technology (FTTH),
here the OXADM is used as a wavelength management element in
Optical Line Terminal (OLT). Each port is assigned specifically with
the operating wavelengths and with the dynamic routing management
to ensure no traffic combustion occurs in OLT.
Abstract: ERP systems are the largest software applications adopted by universities, along with quite significant investments in their implementation. However, unlike other applications little research has been conducted regarding these systems in a university environment. This paper aims at providing a critical review of previous research in ERP system in higher education with a special focus on higher education in Australia. The research not only forms the basis of an evaluation of previous research and research needs, it also makes inroads in identifying the payoff of ERPs in the sector from different perspectives with particular reference to the user. The paper is divided into two parts, the first part focuses on ERP literature in higher education at large, while the second focuses on ERP literature in higher education in Australia.
Abstract: The process for predicting the ballistic properties of a liquid rocket engine is based on the quantitative estimation of idealized performance deviations. In this aim, an equilibrium chemistry procedure is firstly developed and implemented in a Fortran routine. The thermodynamic formulation allows for the calculation of the theoretical performances of a rocket thrust chamber. In a second step, a computational fluid dynamic analysis of the turbulent reactive flow within the chamber is performed using a finite volume approach. The obtained values for the “quasi-real" performances account for both turbulent mixing and chemistryturbulence coupling. In the present work, emphasis is made on the combustion efficiency performance for which deviation is mainly due to radial gradients of static temperature and mixture ratio. Numerical values of the characteristic velocity are successfully compared with results from an industry-used code. The results are also confronted with the experimental data of a laboratory-scale rocket engine.
Abstract: In this paper we have proposed a novel dynamic least cost multicast routing protocol using hybrid genetic algorithm for IP networks. Our protocol finds the multicast tree with minimum cost subject to delay, degree, and bandwidth constraints. The proposed protocol has the following features: i. Heuristic local search function has been devised and embedded with normal genetic operation to increase the speed and to get the optimized tree, ii. It is efficient to handle the dynamic situation arises due to either change in the multicast group membership or node / link failure, iii. Two different crossover and mutation probabilities have been used for maintaining the diversity of solution and quick convergence. The simulation results have shown that our proposed protocol generates dynamic multicast tree with lower cost. Results have also shown that the proposed algorithm has better convergence rate, better dynamic request success rate and less execution time than other existing algorithms. Effects of degree and delay constraints have also been analyzed for the multicast tree interns of search success rate.
Abstract: This paper focuses on the quadratic stabilization problem for a class of uncertain impulsive switched systems. The uncertainty is assumed to be norm-bounded and enters both the state and the input matrices. Based on the Lyapunov methods, some results on robust stabilization and quadratic stabilization for the impulsive switched system are obtained. A stabilizing state feedback control law realizing the robust stabilization of the closed-loop system is constructed.
Abstract: Martensitic stainless steels have been extensively used for their good corrosion resistance and better mechanical properties. Heat treatment was suggested as one of the most excellent ways to this regard; hence, it affects the microstructure, mechanical and corrosion properties of the steel. In the current research work the microstructural changes and corrosion behavior in an AISI 420A stainless steel exposed to temperatures in the 980-1035oC range were investigated. The heat treatment is carried out in vacuum furnace within the said temperature range. The quenching of the samples was carried out in oil, brine and water media. The formation and stability of passive film was studied by Open Circuit Potential, Potentiodynamic polarization and Electrochemical Scratch Tests. The Electrochemical Impedance Spectroscopy results simulated with Equivalent Electrical Circuit suggested bilayer structure of outer porous and inner barrier oxide films. The quantitative data showed thick inner barrier oxide film retarded electrochemical reactions. Micrographs of the quenched samples showed sigma and chromium carbide phases which prove the corrosion resistance of steel alloy.
Abstract: Effective cooling of electronic equipment has emerged
as a challenging and constraining problem of the new century. In the
present work the feasibility and effectiveness of jet impingement
cooling on electronics were investigated numerically and
experimentally. Studies have been conducted to see the effect of the
geometrical parameters such as jet diameter (D), jet to target
spacing (Z) and ratio of jet spacing to jet diameter (Z/D) on the heat
transfer characteristics. The values of Reynolds numbers considered
are in the range 7000 to 42000. The results obtained from the
numerical studies are validated by conducting experiments. From the
studies it is found that the optimum value of Z/D ratio is 5. For a
given Reynolds number, the Nusselt number increases by about 28%
if the diameter of the nozzle is increased from 1mm to 2mm.
Correlations are proposed for Nusselt number in terms of Reynolds
number and these are valid for air as the cooling medium.
Abstract: In distributed resource allocation a set of agents must assign their resources to a set of tasks. This problem arises in many real-world domains such as distributed sensor networks, disaster rescue, hospital scheduling and others. Despite the variety of approaches proposed for distributed resource allocation, a systematic formalization of the problem, explaining the different sources of difficulties, and a formal explanation of the strengths and limitations of key approaches is missing. We take a step towards this goal by using a formalization of distributed resource allocation that represents both dynamic and distributed aspects of the problem. In this paper we present a new idea for target tracking in sensor networks and compare it with previous approaches. The central contribution of the paper is a generalized mapping from distributed resource allocation to DDCSP. This mapping is proven to correctly perform resource allocation problems of specific difficulty. This theoretical result is verified in practice by a simulation on a realworld distributed sensor network.
Abstract: Field mapping activity for an active volcano mainly in
the Torrid Zone is usually hampered by several problems such as steep
terrain and bad atmosphere conditions. In this paper we present a
simple solution for such problem by a combination Synthetic Aperture
Radar (SAR) and geostatistical methods. By this combination, we
could reduce the speckle effect from the SAR data and then estimate
roughness distribution of the pyroclastic flow deposits. The main
purpose of this study is to detect spatial distribution of new pyroclastic
flow deposits termed as P-zone accurately using the β°data from two
RADARSAT-1 SAR level-0 data. Single scene of Hyperion data and
field observation were used for cross-validation of the SAR results.
Mt. Merapi in central Java, Indonesia, was chosen as a study site and
the eruptions in May-June 2006 were examined. The P-zones were
found in the western and southern flanks. The area size and the longest
flow distance were calculated as 2.3 km2 and 6.8 km, respectively. The
grain size variation of the P-zone was mapped in detail from fine to
coarse deposits regarding the C-band wavelength of 5.6 cm.
Abstract: Coagulation of water involves the use of coagulating
agents to bring the suspended matter in the raw water together for
settling and the filtration stage. Present study is aimed to examine the
effects of aluminum sulfate as coagulant in conjunction with Moringa
Oleifera Coagulant Protein as coagulant aid on turbidity, hardness,
and bacteria in turbid water. A conventional jar test apparatus was
employed for the tests. The best removal was observed at a pH of 7
to 7.5 for all turbidities. Turbidity removal efficiency was resulted
between % 80 to % 99 by Moringa Oleifera Coagulant Protein as
coagulant aid. Dosage of coagulant and coagulant aid decreased with
increasing turbidity. In addition, Moringa Oleifera Coagulant Protein
significantly has reduced the required dosage of primary coagulant.
Residual Al+3 in treated water were less than 0.2 mg/l and meets the
environmental protection agency guidelines. The results showed that
turbidity reduction of % 85.9- % 98 paralleled by a primary
Escherichia coli reduction of 1-3 log units (99.2 – 99.97%) was
obtained within the first 1 to 2 h of treatment. In conclusions,
Moringa Oleifera Coagulant Protein as coagulant aid can be used for
drinking water treatment without the risk of organic or nutrient
release. We demonstrated that optimal design method is an efficient
approach for optimization of coagulation-flocculation process and
appropriate for raw water treatment.
Abstract: The importance of nurturing, accumulating, and efficiently deploying knowledge resources through formal structures and organisational mechanisms is well understood. Recent trends in knowledge management (KM) highlight that the effective creation and transfer of knowledge can also rely upon extra-organisational channels, such as, informal networks. The perception exists that the role of informal networks in knowledge creation and performance has been underestimated in the organisational context. Literature indicates that many managers fail to comprehend and successfully exploit the potential role of informal networks to create value for their organisations. This paper investigates: 1) whether managers share work-specific knowledge with informal contacts within and outside organisational boundaries; and 2) what do they think is the importance of this knowledge collaboration in their learning and work outcomes.
Abstract: Located within the tropical belt region, there are
certain rules which should implemented in creating a passive
sustainable housing design in Malaysia. Traditional Malay house
possess a strong character with certain special spaces to create a
sustainable house which suit to the tropical climate in Malaysia. One
of the special space known as verandah or serambi gantung, create
various advantages in solving various issues. However, this special
space is not extremely being applied currently which produce major
issues in term of social and environmental aspects. Hence, this
phenomena create a negative impact to the occupant while Malaysia
already has a best housing design previously. Therefore, this paper
aims to explore both of the main issues mentioned above and reveal
the advantages of implementing verandah into passive sustainable
housing design in Malaysia. A systematic literature review is the
main methodology in this research to identify the various advantages
about verandah.. The study reveals that verandah is the best solution
in term of social and environmental issues and should be
implemented in current housing design in Malaysia.
Abstract: The restoration of extinct ponds is considered as one
of ways to gain new retention capacities for water which is getting
much more important issue with respect to expected impacts of a
climate change. However, there are also other pressures on the
landscape which must be all taken into consideration when making a
decision on the possible restoration of extinct ponds. The research
presented here focuses besides others on the restoration of former
ponds which could be important for both the flood protection and
drought impacts prevention. The first step of the methodology
development for the assessment of such areas is the assessment of
their present state. In this paper, the results of land use types
assessment for 22 localities are presented. These results confirm the
assumption that the most present land use type in such areas is the
permanent grassland. However, the spectra of land use types present
in extinct pond areas is very diverse and include besides others also
airport areas and industry.
Abstract: Fully customized hardware based technology provides high performance and low power consumption by specializing the tasks in hardware but lacks design flexibility since any kind of changes require re-design and re-fabrication. Software based solutions operate with software instructions due to which a great flexibility is achieved from the easy development and maintenance of the software code. But this execution of instructions introduces a high overhead in performance and area consumption. In past few decades the reconfigurable computing domain has been introduced which overcomes the traditional trades-off between flexibility and performance and is able to achieve high performance while maintaining a good flexibility. The dramatic gains in terms of chip performance and design flexibility achieved through the reconfigurable computing systems are greatly dependent on the design of their computational units being integrated with reconfigurable logic resources. The computational unit of any reconfigurable system plays vital role in defining its strength. In this research paper an RFU based computational unit design has been presented using the tightly coupled, multi-threaded reconfigurable cores. The proposed design has been simulated for VLIW based architectures and a high gain in performance has been observed as compared to the conventional computing systems.
Abstract: PCMs have always been viewed as a suitable
candidate for off peak thermal storage, particularly for refrigeration
systems, due to the high latent energy densities of these materials.
However, due to the need to have them encapsulated within a
container this density is reduced. Furthermore, PCMs have a low
thermal conductivity which reduces the useful amount of energy
which can be stored. To consider these factors, the true energy
storage density of a PCM system was proposed and optimised for
PCMs encapsulated in slabs. Using a validated numerical model of
the system, a parametric study was undertaken to investigate the
impact of the slab thickness, gap between slabs and the mass flow
rate. The study showed that, when optimised, a PCM system can
deliver a true energy storage density between 53% and 83% of the
latent energy density of the PCM.
Abstract: The mechanical properties including flexural and
tensile of neat vinyl ester and polymer based on layered silicate
nanocomposite materials are discussed. The addition of layered
silicate into the polymer matrix increased the tensile and flexural
modulus up to 1 wt.% clay loading. The incorporation of more clay
resulted in decreasing the mechanical properties which was traced to
the existence of aggregation layers. Likewise, up to 1 wt.% clay
loading, the thermal behaviour showed significant improvements and
at higher clay loading the thermal pattern was reduced. The
aggregation layers imparted a negative impact on the overall
mechanical and thermal properties. Wide Angle X-ray Diffraction,
Scanning Electron Microscopy and Transmission Electron
Microscopy were utilised in order to characterise the interlamellar
structure of nanocomposites.
Abstract: Image data holds a large amount of different context
information. However, as of today, these resources remain largely
untouched. It is thus the aim of this paper to present a basic technical
framework which allows for a quick and easy exploitation of context
information from image data especially by non-expert users.
Furthermore, the proposed framework is discussed in detail
concerning important social and ethical issues which demand special
requirements in system design. Finally, a first sensor prototype is
presented which meets the identified requirements. Additionally,
necessary implications for the software and hardware design of the
system are discussed, rendering a sensor system which could be
regarded as a good, acceptable and justifiable technical and thereby
enabling the extraction of context information from image data.
Abstract: High Speed PM Generators driven by micro-turbines
are widely used in Smart Grid System. So, this paper proposes
comparative study among six classical, optimized and genetic
analytical design cases for 400 kW output power at tip speed 200
m/s. These six design trials of High Speed Permanent Magnet
Synchronous Generators (HSPMSGs) are: Classical Sizing;
Unconstrained optimization for total losses and its minimization;
Constrained optimized total mass with bounded constraints are
introduced in the problem formulation. Then a genetic algorithm is
formulated for obtaining maximum efficiency and minimizing
machine size. In the second genetic problem formulation, we attempt
to obtain minimum mass, the machine sizing that is constrained by
the non-linear constraint function of machine losses. Finally, an
optimum torque per ampere genetic sizing is predicted. All results are
simulated with MATLAB, Optimization Toolbox and its Genetic
Algorithm. Finally, six analytical design examples comparisons are
introduced with study of machines waveforms, THD and rotor losses.
Abstract: This paper presents preliminary results of a
technology assessment analysis for the use of high pressure treatment
(HPT) on Halloumi cheese. In particular, it presents the importance
of this traditional Cyprus cheese to the island-s economy, explains its
production process, and gives a brief introduction to HPT and its
application on cheese. More importantly, it offers preliminary results
of HPT of Halloumi samples and a preliminary economic feasibility
study on the financial implications of the introduction of such
technology.
Abstract: One of the main environmental problems which affect extensive areas in the world is soil salinity. Traditional data collection methods are neither enough for considering this important environmental problem nor accurate for soil studies. Remote sensing data could overcome most of these problems. Although satellite images are commonly used for these studies, however there are still needs to find the best calibration between the data and real situations in each specified area. Neyshaboor area, North East of Iran was selected as a field study of this research. Landsat satellite images for this area were used in order to prepare suitable learning samples for processing and classifying the images. 300 locations were selected randomly in the area to collect soil samples and finally 273 locations were reselected for further laboratory works and image processing analysis. Electrical conductivity of all samples was measured. Six reflective bands of ETM+ satellite images taken from the study area in 2002 were used for soil salinity classification. The classification was carried out using common algorithms based on the best composition bands. The results showed that the reflective bands 7, 3, 4 and 1 are the best band composition for preparing the color composite images. We also found out, that hybrid classification is a suitable method for identifying and delineation of different salinity classes in the area.