Abstract: The plastic forming process of sheet plate takes an
important place in forming metals. The traditional techniques of tool
design for sheet forming operations used in industry are experimental
and expensive methods. Prediction of the forming results,
determination of the punching force, blank holder forces and the
thickness distribution of the sheet metal will decrease the production
cost and time of the material to be formed. In this paper, multi-stage
deep drawing simulation of an Industrial Part has been presented
with finite element method. The entire production steps with
additional operations such as intermediate annealing and springback
has been simulated by ABAQUS software under axisymmetric
conditions. The simulation results such as sheet thickness
distribution, Punch force and residual stresses have been extracted in
any stages and sheet thickness distribution was compared with
experimental results. It was found through comparison of results, the
FE model have proven to be in close agreement with those of
experiment.
Abstract: Business scenario is an important technique that may be used at various stages of the enterprise architecture to derive its characteristics based on the high-level requirements of the business. In terms of wireless deployments, they are used to help identify and understand business needs involving wireless services, and thereby to derive the business requirements that the architecture development has to address by taking into account of various wireless challenges. This study assesses the deployment of Wireless Local Area Network (WLAN) and Broadband Wireless Access (BWA) solutions for several business scenarios in Asia Pacific region. This paper focuses on the overview of the business and technology environments, whereby examples of existing (or suggested) wireless solutions (to be) adopted in Asia Pacific region will be discussed. Interactions of several players, enabling technologies, and key processes in the wireless environments are studied. The analysis and discussions associated to this study are divided into two divisions: healthcare and education, where the merits of wireless solutions in improving living quality are highlighted.
Abstract: In this paper, the optimum weight and cost of a laminated composite plate is seeked, while it undergoes the heaviest load prior to a complete failure. Various failure criteria are defined for such structures in the literature. In this work, the Tsai-Hill theory is used as the failure criterion. The theory of analysis was based on the Classical Lamination Theory (CLT). A newly type of Genetic Algorithm (GA) as an optimization technique with a direct use of real variables was employed. Yet, since the optimization via GAs is a long process, and the major time is consumed through the analysis, Radial Basis Function Neural Networks (RBFNN) was employed in predicting the output from the analysis. Thus, the process of optimization will be carried out through a hybrid neuro-GA environment, and the procedure will be carried out until a predicted optimum solution is achieved.
Abstract: The background estimation approach using a small
window median filter is presented on the bases of analyzing IR point
target, noise and clutter model. After simplifying the two-dimensional
filter, a simple method of adopting one-dimensional median filter is
illustrated to make estimations of background according to the
characteristics of IR scanning system. The adaptive threshold is used
to segment canceled image in the background. Experimental results
show that the algorithm achieved good performance and satisfy the
requirement of big size image-s real-time processing.
Abstract: Spatial and mobile computing evolves. This paper
describes a smart modeling platform called “GeoSEMA". This
approach tends to model multidimensional GeoSpatial Evolutionary
and Mobile Agents. Instead of 3D and location-based issues, there
are some other dimensions that may characterize spatial agents, e.g.
discrete-continuous time, agent behaviors. GeoSEMA is seen as a
devoted design pattern motivating temporal geographic-based
applications; it is a firm foundation for multipurpose and
multidimensional special-based applications. It deals with
multipurpose smart objects (buildings, shapes, missiles, etc.) by
stimulating geospatial agents.
Formally, GeoSEMA refers to geospatial, spatio-evolutive and
mobile space constituents where a conceptual geospatial space model
is given in this paper. In addition to modeling and categorizing
geospatial agents, the model incorporates the concept of inter-agents
event-based protocols. Finally, a rapid software-architecture
prototyping GeoSEMA platform is also given. It will be
implemented/ validated in the next phase of our work.
Abstract: The acidity of different raw Jordanian clays
containing zeolite, bentonite, red and white kaolinite and diatomite
was characterized by means of temperature programmed desorption
(TPD) of ammonia, conversion of 2-methyl-3-butyn-2-ol (MBOH),
FTIR and BET-measurements. FTIR spectra proved presence of
silanol and bridged hydroxyls on the clay surface. The number of
acidic sites was calculated from experimental TPD-profiles. We
observed the decrease of surface acidity correlates with the decrease
of Si/Al ratio except for diatomite. On the TPD-plot for zeolite two
maxima were registered due to different strength of surface acidic
sites. Values of MBOH conversion, product yields and selectivity
were calculated for the catalysis on Jordanian clays. We obtained that
all clay samples are able to convert MBOH into a major product
which is 3-methyl-3-buten-1-yne (MBYNE) catalyzed by acid
surface sites with the selectivity close to 70%. There was found a
correlation between MBOH conversion and acidity of clays
determined by TPD-NH3, i.e. the higher the acidity the higher the
conversion of MBOH. However, diatomite provided the lowest
conversion of MBOH as result of poor polarization of silanol groups.
Comparison of surface areas and conversions revealed the highest
density of active sites for red kaolinite and the lowest for zeolite and
diatomite.
Abstract: The feasibility of applying a simple and cost effective sliding friction testing apparatus to study the friction behaviour of a clutch facing material, effected by the variation of temperature and contact pressure, was investigated. It was found that the method used in this work was able to give a convenient and cost effective measurement of friction coefficients and their transitions of a clutch facing material. The obtained results will be useful for the development process of new facing materials.
Abstract: We present design, fabrication, and characterization of
a small (12 mm × 12 mm × 8 mm) movable railway vehicle for sensor
carrying. The miniature railway vehicle (MRV) was mainly composed
of a vibrational structure and three legs. A railway was designed and
fabricated to power and guide the MRV. It also transmits the sensed
data from the MRV to the signal processing unit. The MRV with legs
on the railway was moving due to its high-frequency vibration. A
model was derived to describe the motion. Besides, FEM simulations
were performed to design the legs. Then, the MRV and the railway
were fabricated by precision machining. Finally, an infrared sensor
was carried and tested. The result shows that the MRV without loading
was moving along the railway and its maximum speed was 12.2 mm/s.
Moreover, the testing signal was sensed by the MRV.
Abstract: In this paper is reported an analysis about the outdoor air pollution of the urban centre of the city of Messina. The variations of the most critical pollutants concentrations (PM10, O3, CO, C6H6) and their trends respect of climatic parameters and vehicular traffic have been studied. Linear regressions have been effectuated for representing the relations among the pollutants; the differences between pollutants concentrations on weekend/weekday were also analyzed. In order to evaluate air pollution and its effects on human health, a method for calculating a pollution index was implemented and applied in the urban centre of the city. This index is based on the weighted mean of the most detrimental air pollutants concentrations respect of their limit values for protection of human health. The analyzed data of the polluting substances were collected by the Assessorship of the Environment of the Regional Province of Messina in the year 2004. A statistical analysis of the air quality index trends is also reported.
Abstract: Hydrogen is considered to be the most promising
candidate as a future energy carrier. One of the most used
technologies for the electrolytic hydrogen production is alkaline
water electrolysis. However, due to the high energy requirements, the
cost of hydrogen produced in such a way is high. In continuous
search to improve this process using advanced electrocatalytic
materials for the hydrogen evolution reaction (HER), Ni type Raney
and macro-porous Ni-Co electrodes were prepared on AISI 304
stainless steel substrates by electrodeposition. The developed
electrodes were characterized by SEM and confocal laser scanning
microscopy. HER on these electrodes was evaluated in 30 wt.% KOH
solution by means of hydrogen discharge curves and galvanostatic
tests. Results show that the developed electrodes present a most
efficient behaviour for HER when comparing with the smooth Ni
cathode. It has been reported a reduction in the energy consumption
of the electrolysis cell of about 25% by using the developed coatings
as cathodes.
Abstract: This paper presents an equivalent circuit model based on piecewise linear parallel branches (PLPB) to study solar cell modules which are partially shaded. The PLPB model can easily be used in circuit simulation software such as the ElectroMagnetic Transients Program (EMTP). This PLPB model allows the user to simulate several different configurations of solar cells, the influence of partial shadowing on a single or multiple cells, the influence of the number of solar cells protected by a bypass diode and the effect of the cell connection configuration on partial shadowing.
Abstract: Encrypted messages sending frequently draws the attention
of third parties, perhaps causing attempts to break and
reveal the original messages. Steganography is introduced to hide
the existence of the communication by concealing a secret message
in an appropriate carrier like text, image, audio or video. Quantum
steganography where the sender (Alice) embeds her steganographic
information into the cover and sends it to the receiver (Bob) over a
communication channel. Alice and Bob share an algorithm and hide
quantum information in the cover. An eavesdropper (Eve) without
access to the algorithm can-t find out the existence of the quantum
message. In this paper, a text quantum steganography technique based
on the use of indefinite articles (a) or (an) in conjunction with the nonspecific
or non-particular nouns in English language and quantum
gate truth table have been proposed. The authors also introduced a
new code representation technique (SSCE - Secret Steganography
Code for Embedding) at both ends in order to achieve high level of
security. Before the embedding operation each character of the secret
message has been converted to SSCE Value and then embeds to cover
text. Finally stego text is formed and transmits to the receiver side.
At the receiver side different reverse operation has been carried out
to get back the original information.
Abstract: Practicum placements are an critical factor for student teachers on Education Programs. How can student teachers become professionals? This study was to investigate problems, weakness and obstacles of practicum placements and develop guidelines for partnership in the practicum placements. In response to this issue, a partnership concept was implemented for developing student teachers into professionals. Data were collected through questionnaires on attitude toward problems, weaknesses, and obstacles of practicum placements of student teachers in Rajabhat universities and included focus group interviews. The research revealed that learning management, classroom management, curriculum, assessment and evaluation, classroom action research, and teacher demeanor are the important factors affecting the professional development of Education Program student teachers. Learning management plan and classroom management concerning instructional design, teaching technique, instructional media, and student behavior management are another important aspects influencing the professional development for student teachers.
Abstract: Medical image modalities such as computed
tomography (CT), magnetic resonance imaging (MRI), ultrasound
(US), X-ray are adapted to diagnose disease. These modalities
provide flexible means of reviewing anatomical cross-sections and
physiological state in different parts of the human body. The raw
medical images have a huge file size and need large storage
requirements. So it should be such a way to reduce the size of those
image files to be valid for telemedicine applications. Thus the image
compression is a key factor to reduce the bit rate for transmission or
storage while maintaining an acceptable reproduction quality, but it is
natural to rise the question of how much an image can be compressed
and still preserve sufficient information for a given clinical
application. Many techniques for achieving data compression have
been introduced. In this study, three different MRI modalities which
are Brain, Spine and Knee have been compressed and reconstructed
using wavelet transform. Subjective and objective evaluation has
been done to investigate the clinical information quality of the
compressed images. For the objective evaluation, the results show
that the PSNR which indicates the quality of the reconstructed image
is ranging from (21.95 dB to 30.80 dB, 27.25 dB to 35.75 dB, and
26.93 dB to 34.93 dB) for Brain, Spine, and Knee respectively. For
the subjective evaluation test, the results show that the compression
ratio of 40:1 was acceptable for brain image, whereas for spine and
knee images 50:1 was acceptable.
Abstract: Cryptography provides the secure manner of
information transmission over the insecure channel. It authenticates
messages based on the key but not on the user. It requires a lengthy
key to encrypt and decrypt the sending and receiving the messages,
respectively. But these keys can be guessed or cracked. Moreover,
Maintaining and sharing lengthy, random keys in enciphering and
deciphering process is the critical problem in the cryptography
system. A new approach is described for generating a crypto key,
which is acquired from a person-s iris pattern. In the biometric field,
template created by the biometric algorithm can only be
authenticated with the same person. Among the biometric templates,
iris features can efficiently be distinguished with individuals and
produces less false positives in the larger population. This type of iris
code distribution provides merely less intra-class variability that aids
the cryptosystem to confidently decrypt messages with an exact
matching of iris pattern. In this proposed approach, the iris features
are extracted using multi resolution wavelets. It produces 135-bit iris
codes from each subject and is used for encrypting/decrypting the
messages. The autocorrelators are used to recall original messages
from the partially corrupted data produced by the decryption process.
It intends to resolve the repudiation and key management problems.
Results were analyzed in both conventional iris cryptography system
(CIC) and non-repudiation iris cryptography system (NRIC). It
shows that this new approach provides considerably high
authentication in enciphering and deciphering processes.
Abstract: This paper presents a threshold voltage model of pocket implanted sub-100 nm n-MOSFETs incorporating the drain and substrate bias effects using two linear pocket profiles. Two linear equations are used to simulate the pocket profiles along the channel at the surface from the source and drain edges towards the center of the n-MOSFET. Then the effective doping concentration is derived and is used in the threshold voltage equation that is obtained by solving the Poisson-s equation in the depletion region at the surface. Simulated threshold voltages for various gate lengths fit well with the experimental data already published in the literature. The simulated result is compared with the two other pocket profiles used to derive the threshold voltage models of n-MOSFETs. The comparison shows that the linear model has a simple compact form that can be utilized to study and characterize the pocket implanted advanced ULSI devices.
Abstract: Rainfall data at fine resolution and knowledge of its
characteristics plays a major role in the efficient design and operation
of agricultural, telecommunication, runoff and erosion control as well
as water quality control systems. The paper is aimed to study the
statistical distribution of hourly rainfall depth for 12 representative
stations spread across Peninsular Malaysia. Hourly rainfall data of 10
to 22 years period were collected and its statistical characteristics
were estimated. Three probability distributions namely, Generalized
Pareto, Exponential and Gamma distributions were proposed to
model the hourly rainfall depth, and three goodness-of-fit tests,
namely, Kolmogorov-Sminov, Anderson-Darling and Chi-Squared
tests were used to evaluate their fitness. Result indicates that the east
cost of the Peninsular receives higher depth of rainfall as compared
to west coast. However, the rainfall frequency is found to be
irregular. Also result from the goodness-of-fit tests show that all the
three models fit the rainfall data at 1% level of significance.
However, Generalized Pareto fits better than Exponential and
Gamma distributions and is therefore recommended as the best fit.
Abstract: The large and small-scale shaking table tests, which
was conducted for investigating damage evolution of piles inside
liquefied soil, are numerically simulated and experimental verified by the3D nonlinear finite element analysis. Damage evolution of
elasto-plastic circular steel piles and reinforced concrete (RC) one with cracking and yield of reinforcement are focused on, and the failure patterns and residual damages are captured by the proposed constitutive models. The superstructure excitation behind quay wall is
reproduced as well.
Abstract: wind catchers have been served as a cooling system, used to provide acceptable ventilation by means of renewable energy of wind. In the present study, the city of Yazd in arid climate is selected as case study. From the architecture point of view, learning about wind catchers in this study is done by means of field surveys. Research method for selection of the case is based on random form, and analytical method. Wind catcher typology and knowledge of relationship governing the wind catcher's architecture were those measures that are taken for the first time. 53 wind catchers were analyzed. The typology of the wind-catchers is done by the physical analyzing, patterns and common concepts as incorporated in them. How the architecture of wind catcher can influence their operations by analyzing thermal behavior are the archetypes of selected wind catchers. Calculating fluids dynamics science, fluent software and numerical analysis are used in this study as the most accurate analytical approach. The results obtained from these analyses show the formal specifications of wind catchers with optimum operation in Yazd. The knowledge obtained from the optimum model could be used for design and construction of wind catchers with more improved operation
Abstract: The convergence of heterogeneous wireless access technologies characterizes the 4G wireless networks. In such converged systems, the seamless and efficient handoff between
different access technologies (vertical handoff) is essential and remains a challenging problem. The heterogeneous co-existence of access technologies with largely different characteristics creates a decision problem of determining the “best" available network at
“best" time to reduce the unnecessary handoffs. This paper proposes a dynamic decision model to decide the “best" network at “best"
time moment to handoffs. The proposed dynamic decision model make the right vertical handoff decisions by determining the “best"
network at “best" time among available networks based on, dynamic
factors such as “Received Signal Strength(RSS)" of network and
“velocity" of mobile station simultaneously with static factors like Usage Expense, Link capacity(offered bandwidth) and power
consumption. This model not only meets the individual user needs but also improve the whole system performance by reducing the unnecessary handoffs.