Abstract: Software maintenance, which involves making enhancements, modifications and corrections to existing software systems, consumes more than half of developer time. Specification comprehensibility plays an important role in software maintenance as it permits the understanding of the system properties more easily and quickly. The use of formal notation such as B increases a specification-s precision and consistency. However, the notation is regarded as being difficult to comprehend. Semi-formal notation such as the Unified Modelling Language (UML) is perceived as more accessible but it lacks formality. Perhaps by combining both notations could produce a specification that is not only accurate and consistent but also accessible to users. This paper presents an experiment conducted on a model that integrates the use of both UML and B notations, namely UML-B, versus a B model alone. The objective of the experiment was to evaluate the comprehensibility of a UML-B model compared to a traditional B model. The measurement used in the experiment focused on the efficiency in performing the comprehension tasks. The experiment employed a cross-over design and was conducted on forty-one subjects, including undergraduate and masters students. The results show that the notation used in the UML-B model is more comprehensible than the B model.
Abstract: Full - Scale Accelerated Loading System, one part of
“the Eleventh - Five - Year National Grand Technology Infrastructure
Program" is a facility to evaluate the performance and service life of
different kinds of pavements subjected to traffic loading under full -
controlled environment. While simulating the environments of frigid
zone and permafrost zone, the accurate control of air temperature, road
temperature and roadbed temperature are the key points and also
aporias for the designment. In this paper, numerical simulations are
used to determine the design parameters of the frozen soil simulation
system. At first, a brief introduction of the Full - Scale Accelerate
Loading System was given. Then, the temperature control method of
frozen soil simulation system was proposed. Finally, by using finite
element simulations, the optimal design of frozen soil simulation
system was obtained. This proposed design, which was obtained by
finite element simulations, provided significant referents to the
ultimate design of the environment simulation system.
Abstract: The Build-Then-Sell (BTS) is a novel system
implemented in Malaysia after a number of complaints have been
received from buyers in the preceding Sell-Then-Build (STB) system.
When the government announced the implementation of the BTS in
2007, proponents of BTS have asserted that the new system will
provide houses with low level of defects. Their argument however is
not supported by any empirical data. Hence, this study is conducted
to evaluate the housing defects in BTS houses. Six BTS residential
areas have been surveyed to collect the defects data. Questionnaires
were administered directly to the occupiers in each of the BTS houses
through door-to-door visits. The result has shown that the rate of
defects for the six residential areas is ranged from minor to slight,
which only affect the aesthetic value of the house.
Abstract: In this study, the dispersion of heavy particles line in
an isotropic and incompressible three-dimensional turbulent flow has
been studied using the Kinematic Simulation techniques to find out
the evolution of the line fractal dimension. The fractal dimension of
the line is found in the case of different particle gravity (in practice,
different values of particle drift velocity) in the presence of small
particle inertia with a comparison with that obtained in the diffusion
case of material line at the same Reynolds number. It can be
concluded for the dispersion of heavy particles line in turbulent flow
that the particle gravity affect the fractal dimension of the line for
different particle gravity velocities in the range 0.2 < W < 2. With
the increase of the particle drift velocity, the fractal dimension of the
line decreases which may be explained as the particles pass many
scales in their journey in the direction of the gravity and the particles
trajectories do not affect by these scales at high particle drift
velocities.
Abstract: In recent years, there has been an increasing interest in using daylight to save energy in buildings. In tropical regions, daylighting is always an energy saver. On the other hand, daylight provides visual comfort. According to standards, it shows that many criteria should be taken into consideration in order to have daylight utilization and visual comfort. The current standard in Malaysia, MS 1525 does not provide sufficient guideline. Hence, more research is needed on daylight performance. If architects do not consider daylight design, it not only causes inconvenience in working spaces but also causes more energy consumption as well as environmental pollution. This research had surveyed daylight performance in 5 selected office buildings from different area of Malaysian through experimental method. Several parameters of daylight quality such as daylight factor, surface luminance and surface luminance ratio were measured in different rooms in each building. The result of this research demonstrated that most of the buildings were not designed for daylight utilization. Therefore, it is very important that architects follow the daylight design recommendation to reduce consumption of electric power for artificial lighting while the sufficient quality of daylight is available.
Abstract: Data hiding into text documents itself involves pretty
complexities due to the nature of text documents. A robust text
watermarking scheme targeting an object based environment is
presented in this research. The heart of the proposed solution
describes the concept of watermarking an object based text document
where each and every text string is entertained as a separate object
having its own set of properties. Taking advantage of the z-ordering
of objects watermark is applied with the z-axis letting zero fidelity
disturbances to the text. Watermark sequence of bits generated
against user key is hashed with selected properties of given
document, to determine the bit sequence to embed. Bits are
embedded along z-axis and the document has no fidelity issues when
printed, scanned or photocopied.
Abstract: In this paper, for the first time, a two-dimensional
(2D) analytical drain current model for sub-100 nm multi-layered
gate material engineered trapezoidal recessed channel (MLGMETRC)
MOSFET: a novel design is presented and investigated using
ATLAS and DEVEDIT device simulators, to mitigate the large gate
leakages and increased standby power consumption that arise due to
continued scaling of SiO2-based gate dielectrics. The twodimensional
(2D) analytical model based on solution of Poisson-s
equation in cylindrical coordinates, utilizing the cylindrical
approximation, has been developed which evaluate the surface
potential, electric field, drain current, switching metric: ION/IOFF
ratio and transconductance for the proposed design. A good
agreement between the model predictions and device simulation
results is obtained, verifying the accuracy of the proposed analytical
model.
Abstract: An effective approach for realizing the binary tree structure, representing a combinational logic functionality with enhanced throughput, is discussed in this paper. The optimization in maximum operating frequency was achieved through delay minimization, which in turn was possible by means of reducing the depth of the binary network. The proposed synthesis methodology has been validated by experimentation with FPGA as the target technology. Though our proposal is technology independent, yet the heuristic enables better optimization in throughput even after technology mapping for such Boolean functionality; whose reduced CNF form is associated with a lesser literal cost than its reduced DNF form at the Boolean equation level. For cases otherwise, our method converges to similar results as that of [12]. The practical results obtained for a variety of case studies demonstrate an improvement in the maximum throughput rate for Spartan IIE (XC2S50E-7FT256) and Spartan 3 (XC3S50-4PQ144) FPGA logic families by 10.49% and 13.68% respectively. With respect to the LUTs and IOBUFs required for physical implementation of the requisite non-regenerative logic functionality, the proposed method enabled savings to the tune of 44.35% and 44.67% respectively, over the existing efficient method available in literature [12].
Abstract: The impact of a proposed pier on tidal current
alteration was evaluated. The proposed pier location was in Salad
Bay on Koa Kood Island, Trat province, Thailand, and was designed
to accommodate passenger ships with a draft of less than 2 m. The
study began with collecting necessary data, including bathymetric,
water elevation and tidal current characteristics. The impact was
assessed using a software package (MIKE21). Although the results
showed that the pier would affect the existing current pattern, the
change was determined to be insignificant, as the design of the piles
for the pier provided sufficient spacing to let the current flow as
freely as possible. Consequences of the altered current, such as
seabed erosion, water stagnation, sediment deposition and
navigational risk were assessed. Environmental mitigation measures
might be necessary if the impacts were considered unacceptable.
Abstract: Using a force balanced translational-radial dynamics,
phase space of the moving single bubble sonoluminescence (m-
SBSL) in 85% wt sulfuric acid has been numerically calculated. This
phase space is compared with that of single bubble sonoluminescence
(SBSL) in pure water which has been calculated by using the mere
radial dynamics. It is shown that in 85% wt sulfuric acid, in a general
agreement with experiment, the bubble-s positional instability
threshold lays under the shape instability threshold. At the onset of
spatial instability of moving sonoluminescing (SL) bubble in 85%
wt sulfuric acid, temporal effects of the hydrodynamic force on the
bubble translational-radial dynamics have been investigated. The
appearance of non-zero history force on the moving SL bubble is
because of proper condition which was produced by high viscosity of
acid. Around the moving bubble collapse due to the rapid contraction
of the bubble wall, the inertial based added mass force overcomes the
viscous based history force and induces acceleration on the bubble
translational motion.
Abstract: Online learning with Intelligent Tutoring System (ITS) is becoming very popular where the system models the student-s learning behavior and presents to the student the learning material (content, questions-answers, assignments) accordingly. In today-s distributed computing environment, the tutoring system can take advantage of networking to utilize the model for a student for students from other similar groups. In the present paper we present a methodology where using Case Based Reasoning (CBR), ITS provides student modeling for online learning in a distributed environment with the help of agents. The paper describes the approach, the architecture, and the agent characteristics for such system. This concept can be deployed to develop ITS where the tutor can author and the students can learn locally whereas the ITS can model the students- learning globally in a distributed environment. The advantage of such an approach is that both the learning material (domain knowledge) and student model can be globally distributed thus enhancing the efficiency of ITS with reducing the bandwidth requirement and complexity of the system.
Abstract: Subcritical water extraction was investigated as a
novel and alternative technology in the food and pharmaceutical
industry for the separation of Mannitol from olive leaves and its
results was compared with those of Soxhlet extraction. The effects of
temperature, pressure, and flow rate of water and also momentum
and mass transfer dimensionless variables such as Reynolds and
Peclet Numbers on extraction yield and equilibrium partition
coefficient were investigated. The 30-110 bars, 60-150°C, and flow
rates of 0.2-2 mL/min were the water operating conditions. The
results revealed that the highest Mannitol yield was obtained at
100°C and 50 bars. However, extraction of Mannitol was not
influenced by the variations of flow rate. The mathematical modeling
of experimental measurements was also investigated and the model is
capable of predicting the experimental measurements very well. In
addition, the results indicated higher extraction yield for the
subcritical water extraction in contrast to Soxhlet method.
Abstract: This study was conducted to investigate the efficacy
of five herbicides on narrow leaved weeds and growth and yield of
wheat. An experiment was conducted at Agronomic Research
Farm, University of Agriculture Faisalabad. The experiment was
laid out in randomized complete block designee (RCBD) with three
replications. Treatments studied were clodinafop (Topic-15 WG) at
37 g a.i. ha-1, clodinafop (Topaz-15 WG) at 45 g a.i. ha-1,
fenoxaprop-p-ethyl (Puma Super-75 EW) at 45 g a.i. ha-1,
fenoxaprop-p-ethyl (Gramicide-6.9 EW) at 85 g a.i. ha-1,
fenoxaprop-p-ethyl (Chinlima-6.9 EW) at 85 g a.i. ha-1 and weedy
check. Plots treated with fenoxaprop-p-ethyl (Puma Super-75 EW)
at 45 g a.i. ha-1 produced relatively less weed biomass, more plant
height, number of spike bearing tillers, number of grains per spike,
1000-grain weight and grain yield (4.20 t ha-1).
Abstract: In inspection and workpiece localization, sampling point data is an important issue. Since the devices for sampling only sample discrete points, not the completely surface, sampling size and location of the points will be taken into consideration. In this paper a method is presented for determining the sampled points size and location for achieving efficient sampling. Firstly, uncertainty analysis of the localization parameters is investigated. A localization uncertainty model is developed to predict the uncertainty of the localization process. Using this model the minimum size of the sampled points is predicted. Secondly, based on the algebra theory an eigenvalue-optimal optimization is proposed. Then a freeform surface is used in the simulation. The proposed optimization is implemented. The simulation result shows its effectivity.
Abstract: The main objective of this study was to determine if a
minimal increase in road light level (luminance) could lead to
improved driving performance among older adults. Older, middleaged
and younger adults were tested in a driving simulator following
vision and cognitive screening. Comparisons were made for the
performance of simulated night driving under two road light
conditions (0.6 and 2.5 cd/m2). At each light level, the effects of self
reported night driving avoidance were examined along with the
vision/cognitive performance. It was found that increasing road light
level from 0.6 cd/m2 to 2.5 cd/m2 resulted in improved recognition of
signage on straight highway segments. The improvement depends on
different driver-related factors such as vision and cognitive abilities,
and confidence. On curved road sections, the results showed that
driver-s performance worsened. It is concluded that while increasing
road lighting may be helpful to older adults especially for sign
recognition, it may also result in increased driving confidence and
thus reduced attention in some driving situations.
Abstract: In this paper, we present an improved fast and robust
search algorithm for copy detection using histogram-based features for
short MPEG video clips from large video database. There are two
types of histogram features used to generate more robust features. The
first one is based on the adjacent pixel intensity difference quantization
(APIDQ) algorithm, which had been reliably applied to human face
recognition previously. An APIDQ histogram is utilized as the feature
vector of the frame image. Another one is ordinal histogram feature
which is robust to color distortion. Furthermore, by Combining with a
temporal division method, the spatial and temporal features of the
video sequence are integrated to realize fast and robust video search
for copy detection. Experimental results show the proposed algorithm
can detect the similar video clip more accurately and robust than
conventional fast video search algorithm.
Abstract: We present a Large-Eddy simulation of a vortex cell
with circular shaped. The results show that the flow field can be sub
divided into four important zones, the shear layer above the cavity,
the stagnation zone, the vortex core in the cavity and the boundary
layer along the wall of the cavity. It is shown that the vortex core
consits of solid body rotation without much turbulence activity. The
vortex is mainly driven by high energy packets that are driven into the
cavity from the stagnation point region and by entrainment of fluid
from the cavity into the shear layer. The physics in the boundary
layer along the cavity-s wall seems to be far from that of a canonical
boundary layer which might be a crucial point for modelling this
flow.
Abstract: This paper provides an exergy analysis of the multistage refrigeration cycle used for C2+ recovery plant. The behavior of an industrial refrigeration cycle with refrigerant propane has been investigated by the exergy method. A computational model based on the exergy analysis is presented for the investigation of the effects of the valves on the exergy losses, the second law of efficiency, and the coefficient of performance (COP) of a vapor compression refrigeration cycle. The equations of exergy destruction and exergetic efficiency for the main cycle components such as evaporators, condensers, compressors, and expansion valves are developed. The relations for the total exergy destruction in the cycle and the cycle exergetic efficiency are obtained. An ethane recovery unit with its refrigeration cycle has been simulated to prepare the exergy analysis. Using a typical actual work input value; the exergetic efficiency of the refrigeration cycle is determined to be 39.90% indicating a great potential for improvements. The simulation results reveal that the exergetic efficiencies of the heat exchanger and expansion sections get the lowest rank among the other compartments of refrigeration cycle. Refrigeration calculations have been carried out through the analysis of T–S and P–H diagrams where coefficient of performance (COP) was obtained as 1.85. The novelty of this article includes the effect and sensitivity analysis of molar flow, pressure drops and temperature on the exergy efficiency and coefficient of performance of the cycle.
Abstract: Ciprofloxacin (CIP) and Carbamazepine (CBZ), nonbiodegradable pharmaceutical residues, were become emerging pollutants in several aquatic environments. The objectives of this research were to study the possibility to recover these pharmaceuticals residues from pharmaceutical wastewater by increasing the selective adsorption on synthesized functionalized porous silicate, comparing with powdered activated carbon (PAC). Hexagonal mesoporous silicate (HMS), functionalized HMSs (3- aminopropyltriethoxy, 3- mercaptopropyltrimethoxy and noctyldimethyl) were synthesized and characterized physico-chemical characteristics. Obtained adsorption kinetics and isotherms showed that 3-mercaptopropyltrimethoxy functional groups grafted on HMS provided highest CIP and CBZ adsorption capacities; however, it was still lower than that of PAC. The kinetic results were compatible with pseudo-second order. The hydrophobicity and hydrogen bonding might play a key role on the adsorption. Furthermore, the capacities were affected by varying pH values due to the strength of hydrogen bonding between targeted compounds and adsorbents. Electrostatic interaction might not affect the adsorption capacities.
Abstract: The whole work is based on possibility to use Lego Mindstorms robotics systems to reduce costs. Lego Mindstorms consists of a wide variety of hardware components necessary to simulate, programme and test of robotics systems in practice. To programme algorithm, which simulates space using the ultrasonic sensor, was used development environment supplied with kit. Software Matlab was used to render values afterwards they were measured by ultrasonic sensor. The algorithm created for this paper uses theoretical knowledge from area of signal processing. Data being processed by algorithm are collected by ultrasonic sensor that scans 2D space in front of it. Ultrasonic sensor is placed on moving arm of robot which provides horizontal moving of sensor. Vertical movement of sensor is provided by wheel drive. The robot follows map in order to get correct positioning of measured data. Based on discovered facts it is possible to consider Lego Mindstorm for low-cost and capable kit for real-time modelling.