Abstract: The rate of production of main products of the Fischer-Tropsch reactions over Fe/HZSM5 bifunctional catalyst in a fixed bed reactor is investigated at a broad range of temperature, pressure, space velocity, H2/CO feed molar ratio and CO2, CH4 and water flow rates. Model discrimination and parameter estimation were performed according to the integral method of kinetic analysis. Due to lack of mechanism development for Fisher – Tropsch Synthesis on bifunctional catalysts, 26 different models were tested and the best model is selected. Comprehensive one and two dimensional heterogeneous reactor models are developed to simulate the performance of fixed-bed Fischer – Tropsch reactors. To reduce computational time for optimization purposes, an Artificial Feed Forward Neural Network (AFFNN) has been used to describe intra particle mass and heat transfer diffusion in the catalyst pellet. It is seen that products' reaction rates have direct relation with H2 partial pressure and reverse relation with CO partial pressure. The results show that the hybrid model has good agreement with rigorous mechanistic model, favoring that the hybrid model is about 25-30 times faster.
Abstract: Computer-based decision support (CDSS) systems can
deliver real patient care and increase chances of long-term survival in
areas of chronic disease management prone to poor control. One such
CDSS, for the management of warfarin, is described in this paper and
the outcomes shown. Data is derived from the running system and
show a performance consistently around 20% better than the
applicable guidelines.
Abstract: Multicast transmissions allow an host (the source) to send only one flow bound for a group of hosts (the receivers). Any equipment eager to belong to the group may explicitly register itself to that group via its multicast router. This router will be given the responsibility to convey all information relating to the group to all registered hosts. However in an environment in which the final receiver or the source frequently moves, the multicast flows need particular treatment. This constitutes one of the multicast transmissions problems around which several proposals were made in the Mobile IPv6 case in general. In this article, we describe the problems involved in this IPv6 multicast mobility and the existing proposals for their resolution. Then architecture will be proposed aiming to satisfy and optimize these transmissions in the specific case of a mobile multicast receiver in NC-HMIPv6 environment.
Abstract: Knowledge sharing enables the information or
knowledge to be transmitted from one source to another. This paper
demonstrates the needs of having the online book catalogue which
can be used to facilitate disseminating information on textbook used
in the university. This project is aimed to give access to the students
and lecturers to the list of books in the bookstore and at the same
time to allow book reviewing without having to visit the bookstore
physically. Research is carried out according to the boundaries which
accounts to current process of new book purchasing, current system
used by the bookstore and current process the lecturers go through
for reviewing textbooks. The questionnaire is used to gather the
requirements and it is distributed to 100 students and 40 lecturers.
This project has enabled the improvement of a manual process to be
carried out automatically, through a web based platform. It is shown
based on the user acceptance survey carried out that target groups
found that this web service is feasible to be implemented in
Universiti Teknologi PETRONAS (UTP), and they have shown
positive signs of interest in utilizing it in the future.
Abstract: In this paper, 3X3 routing nodes are proposed to
provide speedup and parallel processing capability in Data Vortex
network architectures. The new design not only significantly
improves network throughput and latency, but also eliminates the
need for distributive traffic control mechanism originally embedded
among nodes and the need for nodal buffering. The cost effectiveness
is studied by a comparison study with the previously proposed 2-
input buffered networks, and considerable performance enhancement
can be achieved with similar or lower cost of hardware. Unlike
previous implementation, the network leaves small probability of
contention, therefore, the packet drop rate must be kept low for such
implementation to be feasible and attractive, and it can be achieved
with proper choice of operation conditions.
Abstract: Nanomaterials have attracted considerable attention
during the last two decades, due to their unusual electrical, mechanical
and other physical properties as compared with their bulky
counterparts. The mechanical properties of nanostructured materials
show strong size dependency, which has been explained within the
framework of continuum mechanics by including the effects of surface
stress. The size-dependent deformations of two-dimensional
nanosized structures with surface effects are investigated in the paper
by the finite element method. Truss element is used to evaluate the
contribution of surface stress to the total potential energy and the
Gurtin and Murdoch surface stress model is implemented with
ANSYS through its user programmable features. The proposed
approach is used to investigate size-dependent stress concentration
around a nanosized circular hole and the size-dependent effective
moduli of nanoporous materials. Numerical results are compared with
available analytical results to validate the proposed modeling
approach.
Abstract: The purpose of this investigation is to relate the rain
power and the overland flow power to soil erodibility to assess the
effects of both parameters on soil erosion using variable rainfall
intensity on remoulded agricultural soil. Six rainfall intensities were
used to simulate the natural rainfall and are as follows: 12.4mm/h,
20.3mm/h, 28.6mm/h, 52mm/h, 73.5mm/h and 103mm/h. The results
have shown that the relationship between overland flow power and
rain power is best represented by a linear function (R2=0.99). As
regards the relationships between soil erodibility factor and rain and
overland flow powers, the evolution of both parameters with the
erodibility factor follow a polynomial function with high coefficient
of determination. From their coefficients of determination (R2=0.95)
for rain power and (R2=0.96) for overland flow power, we can
conclude that the flow has more power to detach particles than rain.
This could be explained by the fact that the presence of particles,
already detached by rain and transported by the flow, give the flow
more weight and then contribute to the detachment of particles by
collision.
Abstract: Nowadays, the rapid development of multimedia
and internet allows for wide distribution of digital media data.
It becomes much easier to edit, modify and duplicate digital
information Besides that, digital documents are also easy to
copy and distribute, therefore it will be faced by many
threatens. It-s a big security and privacy issue with the large
flood of information and the development of the digital
format, it become necessary to find appropriate protection
because of the significance, accuracy and sensitivity of the
information. Nowadays protection system classified with more
specific as hiding information, encryption information, and
combination between hiding and encryption to increase information
security, the strength of the information hiding science is due to the
non-existence of standard algorithms to be used in hiding secret
messages. Also there is randomness in hiding methods such as
combining several media (covers) with different methods to pass a
secret message. In addition, there are no formal methods to be
followed to discover the hidden data. For this reason, the task of this
research becomes difficult. In this paper, a new system of information
hiding is presented. The proposed system aim to hidden information
(data file) in any execution file (EXE) and to detect the hidden file
and we will see implementation of steganography system which
embeds information in an execution file. (EXE) files have been
investigated. The system tries to find a solution to the size of the
cover file and making it undetectable by anti-virus software. The
system includes two main functions; first is the hiding of the
information in a Portable Executable File (EXE), through the
execution of four process (specify the cover file, specify the
information file, encryption of the information, and hiding the
information) and the second function is the extraction of the hiding
information through three process (specify the steno file, extract the
information, and decryption of the information). The system has
achieved the main goals, such as make the relation of the size of the
cover file and the size of information independent and the result file
does not make any conflict with anti-virus software.
Abstract: The high temperature degree and uniform
Temperature Distribution (TD) on surface of cookware which contact
with food are effective factors for improving cookware application.
Additionally, the ability of pan material in retaining the heat and nonreactivity
with foods are other significant properties. It is difficult for
single material to meet a wide variety of demands such as superior
thermal and chemical properties. Multi-Layer Plate (MLP) makes
more regular TD. In this study the main objectives are to find the best
structure (single or multi-layer) and materials to provide maximum
temperature degree and uniform TD up side surface of pan. And also
heat retaining of used metals with goal of improving the thermal
quality of pan to economize the energy. To achieve this aim were
employed Finite Element Method (FEM) for analyzing transient
thermal behavior of applied materials. The analysis has been
extended for different metals, we achieved the best temperature
profile and heat retaining in Copper/ Stainless Steel MLP.
Abstract: A new generation of manufacturing machines
so-called MIMCA (modular and integrated machine control
architecture) capable of handling much increased complexity in
manufacturing control-systems is presented. Requirement for more
flexible and effective control systems for manufacturing machine
systems is investigated and dimensioned-which highlights a need for
improved means of coordinating and monitoring production
machinery and equipment used to- transport material. The MIMCA
supports simulation based on machine modeling, was conceived by
the authors to address the issues. Essentially MIMCA comprises an
organized unification of selected architectural frameworks and
modeling methods, which include: NISTRCS, UMC and Colored
Timed Petri nets (CTPN). The unification has been achieved; to
support the design and construction of hierarchical and distributed
machine control which realized the concurrent operation of reusable
and distributed machine control components; ability to handle
growing complexity; and support requirements for real- time control
systems. Thus MIMCA enables mapping between 'what a machine
should do' and 'how the machine does it' in a well-defined but
flexible way designed to facilitate reconfiguration of machine
systems.
Abstract: High strength concrete has been used in situations
where it may be exposed to elevated temperatures. Numerous authors
have shown the significant contribution of polypropylene fiber to the
spalling resistance of high strength concrete.
When cement-based composite that reinforced by polypropylene
fibers heated up to 170 °C, polypropylene fibers readily melt and
volatilize, creating additional porosity and small channels in to the
matrix that cause the poor structure and low strength.
This investigation develops on the mechanical properties of mortar
incorporating polypropylene fibers exposed to high temperature.
Also effects of different pozzolans on strength behaviour of samples
at elevated temperature have been studied.
To reach this purpose, the specimens were produced by partial
replacement of cement with finely ground glass, silica fume and rice
husk ash as high reactive pozzolans. The amount of this replacement
was 10% by weight of cement to find the effects of pozzolans as a
partial replacement of cement on the mechanical properties of
mortars. In this way, lots of mixtures with 0%, 0.5%, 1% and 1.5% of
polypropylene fibers were cast and tested for compressive and
flexural strength, accordance to ASTM standard. After that
specimens being heated to temperatures of 300, 600 °C, respectively,
the mechanical properties of heated samples were tested.
Mechanical tests showed significant reduction in compressive
strength which could be due to polypropylene fiber melting. Also
pozzolans improve the mechanical properties of sampels.
Abstract: After reporting a literature review on Customer
Relationship Management (CRM) and knowledge management, some
important issued arise, in particular related to the lack of success of
CRM strategies implementation. The paper contributes to this
proposing an integrated model of CRM success taking into account
complementary factors such as organizational factors, technology,
knowledge management and customer orientation.
Abstract: This paper describes a new approach of classification
using genetic programming. The proposed technique consists of
genetically coevolving a population of non-linear transformations on
the input data to be classified, and map them to a new space with a
reduced dimension, in order to get a maximum inter-classes
discrimination. The classification of new samples is then performed
on the transformed data, and so become much easier. Contrary to the
existing GP-classification techniques, the proposed one use a
dynamic repartition of the transformed data in separated intervals, the
efficacy of a given intervals repartition is handled by the fitness
criterion, with a maximum classes discrimination. Experiments were
first performed using the Fisher-s Iris dataset, and then, the KDD-99
Cup dataset was used to study the intrusion detection and
classification problem. Obtained results demonstrate that the
proposed genetic approach outperform the existing GP-classification
methods [1],[2] and [3], and give a very accepted results compared to
other existing techniques proposed in [4],[5],[6],[7] and [8].
Abstract: On-line handwritten scripts are usually dealt with pen tip traces from pen-down to pen-up positions. Time evaluation of the pen coordinates is also considered along with trajectory information. However, the data obtained needs a lot of preprocessing including filtering, smoothing, slant removing and size normalization before recognition process. Instead of doing such lengthy preprocessing, this paper presents a simple approach to extract the useful character information. This work evaluates the use of the counter- propagation neural network (CPN) and presents feature extraction mechanism in full detail to work with on-line handwriting recognition. The obtained recognition rates were 60% to 94% using the CPN for different sets of character samples. This paper also describes a performance study in which a recognition mechanism with multiple thresholds is evaluated for counter-propagation architecture. The results indicate that the application of multiple thresholds has significant effect on recognition mechanism. The method is applicable for off-line character recognition as well. The technique is tested for upper-case English alphabets for a number of different styles from different peoples.
Abstract: The modified Claus process is commonly used in oil
refining and gas processing to recover sulfur and destroy
contaminants formed in upstream processing. A Claus furnace feed
containing a relatively low concentration of H2S may be incapable of
producing a stable flame. Also, incomplete combustion of
hydrocarbons in the feed can lead to deterioration of the catalyst in
the reactors due to soot or carbon deposition. Therefore, special
consideration is necessary to achieve the appropriate overall sulfur
recovery. In this paper, some configurations available to treat lean
acid gas streams are described and the most appropriate ones are
studied to overcome low H2S concentration problems. As a result,
overall sulfur recovery is investigated for feed preheating and hot gas
configurations.
Abstract: Application of pesticides in the paddy fields has
deleterious effects on non-target organisms including cyanobacteria
which are photosynthesizing and nitrogen fixing micro-organisms
contributing significantly towards soil fertility and crop yield.
Pesticide contamination in the paddy fields has manifested into a
serious global environmental concern. To study the effect of one such
pesticide, three cyanobacterial strains; Anabaena fertilissima,
Aulosira fertilissima and Westiellopsis prolifica were selected for
their stress responses to an Organochlorine insecticide - 6, 7, 8, 9, 10,
10-hexachloro-1, 5, 5a, 6, 9, 9a-hexahydro-6, 9-methano-2, 4, 3-
benzodioxathiepine-3-oxide, with reference to their photosynthesic
pigments-chlorophyll-a and carotenoids as well as accessory
pigments-phycobiliproteins (phycocyanin, allophycocyanin and
phycoerythrin), stress induced biochemical metabolites like
carbohydrates, proteins, amino acids, phenols and enzymes-nitrate
reductase, glutamine synthetase and succinate dehydrogenase. All
the three cyanobacterial strains were adversely affected by the
insecticide doses and inhibition was dose dependent. Reduction in
photosynthetic and accessory pigments, metabolites, nitrogen fixing
and respiratory enzymes of the test organisms were accompanied
with an initial increase in their total protein at lower Organochlorine
doses. On the other hand, increased amount of phenols in all the
insecticide treated concentrations was indicative of stressed activities
of the organisms.
Abstract: High performance Resistive Random Access Memory
(RRAM) based on HfOx has been prepared and its temperature
instability has been investigated in this work. With increasing
temperature, it is found that: leakage current at high resistance state
increases, which can be explained by the higher density of traps
inside dielectrics (related to trap-assistant tunneling), leading to a
smaller On/Off ratio; set and reset voltages decrease, which may be
attributed to the higher oxygen ion mobility, in addition to the
reduced potential barrier to create / recover oxygen ions (or oxygen
vacancies); temperature impact on the RRAM retention degradation
is more serious than electrical bias.
Abstract: This paper describes the performance of TCP Vegas
over the wireless IPv6 network. The performance of TCP Vegas is
evaluated using network simulator (ns-2). The simulation experiment
investigates how packet spacing affects the network delay, network
throughput and network efficiency of TCP Vegas. Moreover, we
investigate how the variable FTP packet sizes affect the network
performance. The result of the simulation experiment shows that as
the packet spacing is implements, the network delay is reduces,
network throughput and network efficiency is optimizes. As the FTP
packet sizes increase, the ratio of delay per throughput decreases.
From the result of experiment, we propose the appropriate packet size
in transmitting file transfer protocol application using TCP Vegas
with packet spacing enhancement over wireless IPv6 environment in
ns-2. Additionally, we suggest the appropriate ratio in determining
the appropriate RTT and buffer size in a network.
Abstract: Facing the concern of the population to its environment and to climatic change, city planners are now considering the urban climate in their choices of planning. The urban climate, representing different urban morphologies across central Bangkok metropolitan area (BMA), are used to investigates the effects of both the composition and configuration of variables of urban morphology indicators on the summer diurnal range of urban climate, using correlation analyses and multiple linear regressions. Results show first indicate that approximately 92.6% of the variation in the average maximum daytime near-surface air temperature (Ta) was explained jointly by the two composition variables of urban morphology indicators including open space ratio (OSR) and floor area ratio (FAR). It has been possible to determine the membership of sample areas to the local climate zones (LCZs) using these urban morphology descriptors automatically computed with GIS and remote sensed data. Finally result found the temperature differences among zones of large separation, such as the city center could be respectively from 35.48±1.04ºC (Mean±S.D.) warmer than the outskirt of Bangkok on average for maximum daytime near surface temperature to 28.27±0.21ºC for extreme event and, can exceed as 8ºC. A spatially disaggregation of urban thermal responsiveness map would be helpful for several reasons. First, it would localize urban areas concerned by different climate behavior over summer daytime and be a good indicator of urban climate variability. Second, when overlaid with a land cover map, this map may contribute to identify possible urban management strategies to reduce heat wave effects in BMA.
Abstract: A macroscopic constitutive equation is developed for a high-density cellulose insulation material with emphasis on the outof- plane stress relaxation behavior. A hypothesis is proposed where the total stress is additively composed by an out-of-plane visco-elastic isotropic contribution and an in-plane elastic orthotropic response. The theory is validated against out-of-plane stress relaxation, compressive experiments and in-plane tensile hysteresis, respectively. For large scale finite element simulations, the presented model provides a balance between simplicity and capturing the materials constitutive behaviour.