Abstract: This paper presents a new spread-spectrum
watermarking algorithm for digital images in discrete wavelet
transform (DWT) domain. The algorithm is applied for embedding
watermarks like patient identification /source identification or
doctors signature in binary image format into host digital
radiological image for potential telemedicine applications.
Performance of the algorithm is analysed by varying the gain factor,
subband decomposition levels, and size of watermark. Simulation
results show that the proposed method achieves higher watermarking
capacity.
Abstract: The objective of this research is to investigate the
advantages of using large-diameter 0.7 inch prestressing strands in
pretention applications. The advantages of large-diameter strands are
mainly beneficial in the heavy construction applications. Bridges and
tunnels are subjected to a higher daily traffic with an exponential
increase in trucks ultimate weight, which raise the demand for higher
structural capacity of bridges and tunnels. In this research, precast
prestressed I-girders were considered as a case study. Flexure
capacities of girders fabricated using 0.7 inch strands and different
concrete strengths were calculated and compared to capacities of 0.6
inch strands girders fabricated using equivalent concrete strength.
The effect of bridge deck concrete strength on composite deck-girder
section capacity was investigated due to its possible effect on final
section capacity. Finally, a comparison was made to compare the
bridge cross-section of girders designed using regular 0.6 inch strands
and the large-diameter 0.7 inch. The research findings showed that
structural advantages of 0.7 inch strands allow for using fewer bridge
girders, reduced material quantity, and light-weight members. The
structural advantages of 0.7 inch strands are maximized when high
strength concrete (HSC) are used in girder fabrication, and concrete
of minimum 5ksi compressive strength is used in pouring bridge
decks. The use of 0.7 inch strands in bridge industry can partially
contribute to the improvement of bridge conditions, minimize
construction cost, and reduce the construction duration of the project.
Abstract: The main objective of this research was to investigate
the biosorption capacity for biofilms of sulphate reducing bacteria
(SRB) to remove heavy metals, such as Zn, Pb and Cd from
rainwater using laboratory-scale reactors containing mixed support
media. Evidence showed that biosorption had contributed to removal
of heavy metals including Zn, Pb and Cd in presence of SRB and
SRB were also found in the aqueous samples from reactors.
However, the SRB and specific families (Desulfobacteriaceae and
Desulfovibrionaceae) were found mainly in the biomass samples
taken from all reactors at the end of the experiment. EDX-analysis
of reactor solids at end of experiment showed that heavy metals Zn,
Pb and Cd had also accumulated in these precipitates.
Abstract: The use of composite materials in offshore engineering for deep sea oil production riser systems has drawn considerable interest due to the potential weight savings and improvement in durability. The design of composite risers consists of two stages: (1) local design based on critical local load cases, and (2) global analysis of the full length composite riser under global loads and assessment of critical locations. In the first stage, eight different material combinations were selected and their laminate configurations optimised under local load considerations. Stage two includes a final local stress analysis of the critical sections of the riser under the combined loads determined in the global analysis. This paper describes two design methodologies of the composite riser to provide minimum structural weight and shows that the use of off angle fibre orientations in addition to axial and hoop reinforcements offer substantial weight savings and ensure the structural capacity.
Abstract: This study investigates the roles of knowledge
acquisition, absorptive capacity, and innovation capability in finance
and manufacturing industries. With 362 valid questionnaires from
manufactures and financial industries in Taiwan, we examine the
relationships between absorptive capacity, knowledge acquisition and
innovation capability using a structural equation model. The results
indicate that absorptive capacity is the mediator between knowledge
acquisition and innovation capability, and that knowledge acquisition
has a positive effect on absorptive capacity.
Abstract: In this paper, we propose a high capacity image hiding
technology based on pixel prediction and the difference of modified histogram. This approach is used the pixel prediction and the
difference of modified histogram to calculate the best embedding point.
This approach can improve the predictive accuracy and increase the pixel difference to advance the hiding capacity. We also use the
histogram modification to prevent the overflow and underflow. Experimental results demonstrate that our proposed method within the
same average hiding capacity can still keep high quality of image and low distortion
Abstract: In this paper, a new reversible watermarking method is presented that reduces the size of a stereoscopic image sequence while keeping its content visible. The proposed technique embeds the residuals of the right frames to the corresponding frames of the left sequence, halving the total capacity. The residual frames may result in after a disparity compensated procedure between the two video streams or by a joint motion and disparity compensation. The residuals are usually lossy compressed before embedding because of the limited embedding capacity of the left frames. The watermarked frames are visible at a high quality and at any instant the stereoscopic video may be recovered by an inverse process. In fact, the left frames may be exactly recovered whereas the right ones are slightly distorted as the residuals are not embedded intact. The employed embedding method reorders the left frame into an array of consecutive pixel pairs and embeds a number of bits according to their intensity difference. In this way, it hides a number of bits in intensity smooth areas and most of the data in textured areas where resulting distortions are less visible. The experimental evaluation demonstrates that the proposed scheme is quite effective.
Abstract: The reduction of hexavalent chromium by scrap iron
was investigated in continuous system, using long-term column
experiments, for aqueous Cr(VI) solutions having low buffering
capacities, over the Cr(VI) concentration range of 5 – 40 mg/L. The
results showed that the initial Cr(VI) concentration significantly
affects the reduction capacity of scrap iron. Maximum reduction
capacity of scrap iron was observed at the beginning of the column
experiments; the lower the Cr(VI) concentration, the greater the
experiment duration with maximum scrap iron reduction capacity.
However, due to passivation of active surface, scrap iron reduction
capacity continuously decreased in time, especially after Cr(VI)
breakthrough. The experimental results showed that highest
reduction capacity recorded until Cr(VI) breakthrough was 22.8 mg
Cr(VI)/g scrap iron, at CI = 5 mg/L, and decreased with increasing
Cr(VI) concentration. In order to assure total reduction of greater
Cr(VI) concentrations for a longer period of time, either the mass of
scrap iron filling, or the hydraulic retention time should be increased.
Abstract: Existing underground pipe jacking methods use a
reinforcing rod in a steel tube to obtain structural stiffness. However,
some problems such as inconvenience of works and expensive
materials resulted from limited working space and reinforcing works
are existed. To resolve these problems, a new pipe jacking method,
namely PST (Prestressed Segment Tunnel) method, was developed
which used joint to connect the steel segment and form erection
structure. For evaluating the flexural capacity of the PST method
structure, a experimental test was conducted. The parameters
considered in the test were span-to-depth ratio of segment, diameter of
steel tube at the corner, prestressing force, and welding of joint. The
flexural behaviours with the effect of load capacity in serviceability
state according to different parameters were examined.. The frame
with long segments could increase flexural stiffness and the specimen
with large diameter of concave corner showed excellent resistance
ability to the negative moment. In addition, welding of joints increased
the flexural capacity.
Abstract: It is necessary to evaluate the bridges conditions and
strengthen bridges or parts of them. The reinforcement necessary due
to some reasons can be summarized as: First, a changing in use of
bridge could produce internal forces in a part of structural which
exceed the existing cross-sectional capacity. Second, bridges may
also need reinforcement because damage due to external factors
which reduced the cross-sectional resistance to external loads. One of
other factors could listed here its misdesign in some details, like
safety of bridge or part of its.This article identify the design demands
of Qing Shan bridge located in is in Heilongjiang Province He gang -
Nen Jiang Road 303 provincial highway, Wudalianchi area, China, is
an important bridge in the urban areas. The investigation program
was include the observation and evaluate the damage in T- section
concrete beams , prestressed concrete box girder bridges section in
additional evaluate the whole state of bridge includes the pier ,
abutments , bridge decks, wings , bearing and capping beam, joints,
........etc. The test results show that the bridges in general structural
condition are good. T beam span No 10 were observed, crack
extended upward along the ribbed T beam, and continue to the T
beam flange. Crack width varying between 0.1mm to 0.4mm, the
maximum about 0.4mm. The bridge needs to be improved flexural
bending strength especially at for T beam section.
Abstract: Perturbed-Chain Statistical Association Fluid Theory (PC-SAFT) equation of state (EOS) is a modified SAFT EOS with three pure component specific parameters: segment number (m), diameter (σ) and energy (ε). These PC-SAFT parameters need to be determined for each component under the conditions of interest by fitting experimental data, such as vapor pressure, density or heat capacity. PC-SAFT parameters for propane, ethylene and hydrogen in supercritical region were successfully estimated by fitting experimental density data available in literature. The regressed PCSAFT parameters were compared with the literature values by means of estimating pure component density and calculating average absolute deviation between the estimated and experimental density values. PC-SAFT parameters available in literature especially for ethylene and hydrogen estimated density in supercritical region reasonably well. However, the regressed PC-SAFT parameters performed better in supercritical region than the PC-SAFT parameters from literature.
Abstract: In this paper the behavior of fixed series compensated
extra high voltage transmission lines during faults is simulated. Many
over-voltage protection schemes for series capacitors are limited in
terms of size and performance, and are easily affected by
environmental conditions. While the need for more compact and
environmentally robust equipment is required. use of series
capacitors for compensating part of the inductive reactance of long
transmission lines increases the power transmission capacity.
Emphasis is given on the impact of modern capacitor protection
techniques (MOV protection). The simulation study is performed
using MATLAB/SIMULINK®and results are given for a three phase
and a single phase to ground fault.
Abstract: The composition, vapour pressure, and heat capacity
of nine biodiesel fuels from different sources were measured. The
vapour pressure of the biodiesel fuels is modeled assuming an ideal
liquid phase of the fatty acid methyl esters constituting the fuel. New
methodologies to calculate the vapour pressure and ideal gas and
liquid heat capacities of the biodiesel fuel constituents are proposed.
Two alternative optimization scenarios are evaluated: 1) vapour
pressure only; 2) vapour pressure constrained with liquid heat
capacity. Without physical constraints, significant errors in liquid
heat capacity predictions were found whereas the constrained
correlation accurately fit both vapour pressure and liquid heat
capacity.
Abstract: The main aim of the presented experiments is to
improve behaviour of sandwich structures under dynamic loading,
such as crash or explosion. Several cellular materials are widely used
as core of the sandwich structures and their properties influence
the response of the entire element under impact load. To optimize
their performance requires the characterisation of the core material
behaviour at high strain rates and identification of the underlying
mechanism. This work presents the study of high strain-rate
characteristics of a specific porous lightweight blast energy absorbing
foam using a Split Hopkinson Pressure Bar (SHPB) technique
adapted to perform tests on low strength materials. Two different
velocities, 15 and 30 m.s-1 were used to determine the strain
sensitivity of the material. Foams were designed using two types of
porous lightweight spherical raw materials with diameters of 30-
100 *m, combined with polymer matrix. Cylindrical specimens with
diameter of 15 mm and length of 7 mm were prepared and loaded
using a Split Hopkinson Pressure Bar apparatus to assess the relation
between the composition of the material and its shock wave
attenuation capacity.
Abstract: We propose a novel prioritized limited
processor-sharing (PS) rule and a simulation algorithm for the performance evaluation of this rule. The performance measures of practical interest are evaluated using this algorithm. Suppose that there
are two classes and that an arriving (class-1 or class-2) request encounters n1 class-1 and n2 class-2 requests (including the arriving
one) in a single-server system. According to the proposed rule, class-1
requests individually and simultaneously receive m / (m * n1+ n2) of the service-facility capacity, whereas class-2 requests receive 1 / (m *n1 + n2) of it, if m * n1 + n2 ≤ C. Otherwise (m * n1 + n2 > C), the arriving request will be queued in the corresponding class waiting
room or rejected. Here, m (1) denotes the priority ratio, and C ( ∞), the service-facility capacity. In this rule, when a request arrives at [or
departs from] the system, the extension [shortening] of the remaining
sojourn time of each request receiving service can be calculated using
the number of requests of each class and the priority ratio. Employing
a simulation program to execute these events and calculations enables
us to analyze the performance of the proposed prioritized limited PS
rule, which is realistic in a time-sharing system (TSS) with a
sufficiently small time slot. Moreover, this simulation algorithm is
expanded for the evaluation of the prioritized limited PS system with
N 3 priority classes.
Abstract: To reduce the carbon dioxide emission into the
atmosphere, adsorption is believed to be one of the most attractive
methods for post-combustion treatment of flue gas. In this work,
activated carbon (AC) was modified by polyethylenimine (PEI) via
impregnation in order to enhance CO2 adsorption capacity. The
adsorbents were produced at 0.04, 0.16, 0.22, 0.25, and 0.28 wt%
PEI/AC. The adsorption was carried out at a temperature range from
30 °C to 75 °C and five different gas pressures up to 1 atm. TG-DTA,
FT-IR, UV-visible spectrometer, and BET were used to characterize
the adsorbents. Effects of PEI loading on the AC for the CO2
adsorption were investigated. Effectiveness of the adsorbents on the
CO2 adsorption including CO2 adsorption capacity and adsorption
temperature was also investigated. Adsorption capacities of CO2 were
enhanced with the increase in the amount of PEI from 0.04 to 0.22
wt% PEI before the capacities decreased onwards from0.25 wt% PEI
at 30 °C. The 0.22 wt% PEI/AC showed higher adsorption capacity
than the AC for adsorption at 50 °C to 75 °C.
Abstract: Most electrical distribution systems are incurring large
losses as the loads are wide spread, inadequate reactive power
compensation facilities and their improper control. A typical static
VAR compensator consists of capacitor bank in binary sequential
steps operated in conjunction with a thyristor controlled reactor of the
smallest step size. This SVC facilitates stepless control of reactive
power closely matching with load requirements so as to maintain
power factor nearer to unity. This type of SVC-s requiring a
appropriately controlled TCR. This paper deals with an air cored
reactor suitable for distribution transformer of 3phase, 50Hz, Dy11,
11KV/433V, 125 KVA capacity. Air cored reactors are designed,
built, tested and operated in conjunction with capacitor bank in five
binary sequential steps. It is established how the delta connected TCR
minimizes the harmonic components and the operating range for
various electrical quantities as a function of firing angle is
investigated. In particular firing angle v/s line & phase currents, D.C.
components, THD-s, active and reactive powers, odd and even triplen
harmonics, dominant characteristic harmonics are all investigated and
range of firing angle is fixed for satisfactory operation. The harmonic
spectra for phase and line quantities at specified firing angles are
given. In case the TCR is operated within the bound specified in this
paper established through simulation studies are yielding the best
possible operating condition particularly free from all dominant
harmonics.
Abstract: In this paper, we investigate the strategic stochastic air traffic flow management problem which seeks to balance airspace capacity and demand under weather disruptions. The goal is to reduce the need for myopic tactical decisions that do not account for probabilistic knowledge about the NAS near-future states. We present and discuss a scenario-based modeling approach based on a time-space stochastic process to depict weather disruption occurrences in the NAS. A solution framework is also proposed along with a distributed implementation aimed at overcoming scalability problems. Issues related to this implementation are also discussed.
Abstract: Hexavalent chromium is highly toxic to most living organisms and a known human carcinogen by the inhalation route of exposure. Therefore, treatment of Cr(VI) contaminated wastewater is essential before their discharge to the natural water bodies. Cr(VI) reduction to Cr(III) can be beneficial because a more mobile and more toxic chromium species is converted to a less mobile and less toxic form. Zero-valence-state metals, such as scrap iron, can serve as electron donors for reducing Cr(VI) to Cr(III). The influence of pH on scrap iron capacity to reduce Cr(VI) was investigated in this study. Maximum reduction capacity of scrap iron was observed at the beginning of the column experiments; the lower the pH, the greater the experiment duration with maximum scrap iron reduction capacity. The experimental results showed that highest maximum reduction capacity of scrap iron was 12.5 mg Cr(VI)/g scrap iron, at pH 2.0, and decreased with increasing pH up to 1.9 mg Cr(VI)/g scrap iron at pH = 7.3.
Abstract: A new chelating resin is prepared by coupling Amberlite XAD-4 with 1-amino-2-naphthole through an azo spacer. The resulting sorbent has been characterized by FT-IR, elemental analysis and thermogravimetric analysis (TGA) and studied for preconcentrating of Fe (II) using flame atomic absorption spectrometry (FAAS) for metal monitoring. The optimum pH value for sorption of the iron ions was 6.5. The resin was subjected to evaluation through batch binding of mentioned metal ion. Quantitative desorption occurs instantaneously with 0.5 M HNO3. The sorption capacity was found 4.1 mmol.g-1 of resin for Fe (II) in the aqueous solution. The chelating resin can be reused for 10 cycles of sorption-desorption without any significant change in sorption capacity. A recovery of 97% was obtained the metal ions with 0.5 M HNO3 as eluting agent. The method was applied for metal ions determination from industrial waste water sample.