Abstract: In this paper, we study the knapsack sharing problem, a variant of the well-known NP-Hard single knapsack problem. We investigate the use of a tree search for optimally solving the problem. The used method combines two complementary phases: a reduction interval search phase and a branch and bound procedure one. First, the reduction phase applies a polynomial reduction strategy; that is used for decomposing the problem into a series of knapsack problems. Second, the tree search procedure is applied in order to attain a set of optimal capacities characterizing the knapsack problems. Finally, the performance of the proposed optimal algorithm is evaluated on a set of instances of the literature and its runtime is compared to the best exact algorithm of the literature.
Abstract: The paper investigates parallel channel instabilities of
natural circulation boiling water reactor. A thermal-hydraulic model
is developed to simulate two-phase flow behavior in the natural circulation boiling water reactor (NCBWR) with the incorporation of
ex-core components and recirculation loop such as steam separator, down-comer, lower-horizontal section and upper-horizontal section
and then, numerical analysis is carried out for parallel channel
instabilities of the reactor undergoing both in-phase and out-of-phase
modes of oscillations. To analyze the relative effect on stability of the reactor due to inclusion of various ex-core components and
recirculation loop, marginal stable point is obtained at a particular inlet enthalpy of the reactor core without the inclusion of ex-core
components and recirculation loop and then with the inclusion of the
same. Numerical simulations are also conducted to determine the
relative dominance between two modes of oscillations i.e. in-phase and out-of-phase. Simulations are also carried out when the channels
are subjected to asymmetric power distribution keeping the inlet enthalpy same.
Abstract: Thermal-driven refrigeration systems have attracted increasing research and development interest in recent years. These systems do not cause ozone depletion and can reduce demand on electricity. The main objective of this work is to perform theoretical analyses of a thermal-driven refrigeration system using a new sorbent-sorptive pair as the working pair. The active component of sorbent is sodium thiocyanate (NaSCN). Ammonia (NH3) is chosen as sorptive. Based on the thermodynamic properties of the working solution, a mathematical model is introduced to analyze the system characteristics and performance. The results are used to compare with other thermal-driven refrigeration systems. It is shown that the advantages provided by this system over other absorption units include lower generator and evaporator temperatures, a higher coefficient of performance (COP). The COP is about 10 percent higher than the ones for the NH3-H2O system working at the same conditions.
Abstract: Attempt was made to improve certain characteristics of bio-oil derived from palm kernel pyrolysis by blending it with diesel fuel and alcohols. Two types of alcohol, ethanol or butanol, was used as cosolvent to stabilize the phase of ternary systems. Phase behaviors and basic fuel properties of palm kernel bio-oildiesel- alcohol systems were investigated in this study. Alcohol types showed a significant influence on the phase characteristics with palm kernel bio-oil-diesel-butanol system giving larger soluble area than that of palm kernel bio-oil-diesel-ethanol system. For fuel properties, blended fuels showed superior properties including lower values of density (~860 kg/m3 at 25°C), viscosity (~4.12 mm2/s at 40°C), carbon residue (1.02-2.53 wt%), ash (0.018-0.034 wt%) and pour point (
Abstract: This paper proposes different methods for estimation
of the harmonic currents of the single-phase diode bridge rectifier. Both simple and advanced methods are compared and the models are
put into a context of practical use for calculating the harmonic distortion in a typical application. Finally, the different models are
compared to measurements of a real application and convincing results are achieved.
Abstract: In this paper, an approach to reduce the computation steps required by fast neural networksfor the searching process is presented. The principle ofdivide and conquer strategy is applied through imagedecomposition. Each image is divided into small in sizesub-images and then each one is tested separately usinga fast neural network. The operation of fast neuralnetworks based on applying cross correlation in thefrequency domain between the input image and theweights of the hidden neurons. Compared toconventional and fast neural networks, experimentalresults show that a speed up ratio is achieved whenapplying this technique to locate human facesautomatically in cluttered scenes. Furthermore, fasterface detection is obtained by using parallel processingtechniques to test the resulting sub-images at the sametime using the same number of fast neural networks. Incontrast to using only fast neural networks, the speed upratio is increased with the size of the input image whenusing fast neural networks and image decomposition.
Abstract: This paper proposes a dual tree complex wavelet transform (DT-CWT) based directional interpolation scheme for noisy images. The problems of denoising and interpolation are modelled as to estimate the noiseless and missing samples under the same framework of optimal estimation. Initially, DT-CWT is used to decompose an input low-resolution noisy image into low and high frequency subbands. The high-frequency subband images are interpolated by linear minimum mean square estimation (LMMSE) based interpolation, which preserves the edges of the interpolated images. For each noisy LR image sample, we compute multiple estimates of it along different directions and then fuse those directional estimates for a more accurate denoised LR image. The estimation parameters calculated in the denoising processing can be readily used to interpolate the missing samples. The inverse DT-CWT is applied on the denoised input and interpolated high frequency subband images to obtain the high resolution image. Compared with the conventional schemes that perform denoising and interpolation in tandem, the proposed DT-CWT based noisy image interpolation method can reduce many noise-caused interpolation artifacts and preserve well the image edge structures. The visual and quantitative results show that the proposed technique outperforms many of the existing denoising and interpolation methods.
Abstract: This paper applies the homotopy analysis method method to a nonlinear differential-difference equation arising in nanotechnology. Continuum hypothesis on nanoscales is invalid, and a differential-difference model is considered as an alternative approach to describing discontinued problems. Comparison of the approximate solution with the exact one reveals that the method is very effective.
Abstract: Feature-based registration is an effective technique for clinical use, because it can greatly reduce computational costs. However, this technique, which estimates the transformation by using feature points extracted from two images, may cause misalignments. To handle with this limitation, we propose to extract the salient edges and extracted control points (CP) of medical images by using efficiency of multiresolution representation of data nonsubsampled contourlet transform (NSCT) that finds the best feature points. The MR images were first decomposed using the NSCT, and then Edge and CP were extracted from bandpass directional subband of NSCT coefficients and some proposed rules. After edge and CP extraction, mutual information was adopted for the registration of feature points and translation parameters are calculated by using particle swarm optimization (PSO). The experimental results showed that the proposed method produces totally accurate performance for registration medical CT-MR images.
Abstract: Moral decisions are considered as an intuitive process,
while conscious reasoning is mostly used only to justify those
intuitions. This problem is described in few different dual-process
theories of mind, that are being developed e.g. by Frederick and
Kahneman, Stanovich and Evans. Those theories recently evolved
into tri-process theories with a proposed process that makes ultimate
decision or allows to paraformal processing with focal bias..
Presented experiment compares the decision patterns to the
implications of those models.
In presented study participants (n=179) considered different
aspects of trolley dilemma or its footbridge version and decided after
that.
Results show that in the control group 70% of people decided to
use the lever to change tracks for the running trolley, and 20% chose
to push the fat man down the tracks. In contrast, after experimental
manipulation almost no one decided to act. Also the decision time
difference between dilemmas disappeared after experimental
manipulation.
The result supports the idea of three co-working processes:
intuitive (TASS), paraformal (reflective mind) and algorithmic
process.
Abstract: EEG signal is one of the oldest measures of brain
activity that has been used vastly for clinical diagnoses and
biomedical researches. However, EEG signals are highly
contaminated with various artifacts, both from the subject and from
equipment interferences. Among these various kinds of artifacts,
ocular noise is the most important one. Since many applications such
as BCI require online and real-time processing of EEG signal, it is
ideal if the removal of artifacts is performed in an online fashion.
Recently, some methods for online ocular artifact removing have
been proposed. One of these methods is ARMAX modeling of EEG
signal. This method assumes that the recorded EEG signal is a
combination of EOG artifacts and the background EEG. Then the
background EEG is estimated via estimation of ARMAX parameters.
The other recently proposed method is based on adaptive filtering.
This method uses EOG signal as the reference input and subtracts
EOG artifacts from recorded EEG signals. In this paper we
investigate the efficiency of each method for removing of EOG
artifacts. A comparison is made between these two methods. Our
undertaken conclusion from this comparison is that adaptive filtering
method has better results compared with the results achieved by
ARMAX modeling.
Abstract: With the tremendous growth of World Wide Web
(WWW) data, there is an emerging need for effective information
retrieval at the document level. Several query languages such as
XML-QL, XPath, XQL, Quilt and XQuery are proposed in recent
years to provide faster way of querying XML data, but they still lack of
generality and efficiency. Our approach towards evolving a framework
for querying semistructured documents is based on formal query
algebra. Two elements are introduced in the proposed framework:
first, a generic and flexible data model for logical representation of
semistructured data and second, a set of operators for the manipulation
of objects defined in the data model. In additional to accommodating
several peculiarities of semistructured data, our model offers novel
features such as bidirectional paths for navigational querying and
partitions for data transformation that are not available in other
proposals.
Abstract: Transportation authorities need to provide the services
and facilities that are critical to every country-s well-being and
development. Management of the road network is becoming
increasingly challenging as demands increase and resources are
limited. Public sector institutions are integrating performance
information into budgeting, managing and reporting via
implementing performance measurement systems. In the face of
growing challenges, performance measurement of road networks is
attracting growing interest in many countries. The large scale of
public investments makes the maintenance and development of road
networks an area where such systems are an important assessment
tool. Transportation agencies have been using performance
measurement and modeling as part of pavement and bridge
management systems. Recently the focus has been on extending the
process to applications in road construction and maintenance
systems, operations and safety programs, and administrative
structures and procedures. To eliminate failure and dysfunctional
consequences the importance of obtaining objective data and
implementing evaluation instrument where necessary is presented in
this paper
Abstract: The spreading characteristics of acoustically excited
swirling double-concentric jets were studied experimentally. The
central jet was acoustically excited at low and high pulsation
intensities. A smoke wire flow visualization and a hot-wire
anemometer velocity measurement results show that excitation forces
a vortex ring to roll-up from the edge of the central tube during each
excitation period. At low pulsation intensities, the vortex ring evolves
downstream, and eventually breaks up into turbulent eddies. At high
pulsation intensities, the primary vortex ring evolves and a series of
trailing vortex rings form during the same period of excitation. The
trailing vortex rings accelerate while evolving downstream and
overtake the primary vortex ring within the same cycle. In the
process, the primary vortex ring becomes unstable and breaks up
early. The effect of the fast traveling trailing vortex rings combined
with the swirl motion of the annular flow improve jet spreading
compared with the naturally evolving jets.
Abstract: Citizens are increasingly are provided with choice and
customization in public services and this has now also become a key
feature of higher education in terms of policy roll-outs on personal
development planning (PDP) and more generally as part of the
employability agenda. The goal here is to transform people, in this
case graduates, into active, responsible citizen-workers. A key part of
this rhetoric and logic is the inculcation of graduate attributes within
students. However, there has also been a concern with the issue of
student lack of engagement and perseverance with their studies. This
paper sets out to explore some of these conceptions that link graduate
attributes with citizenship as well as the notion of how identity is
forged through the higher education process. Examples are drawn
from a quality enhancement project that is being operated within the
context of the Scottish higher education system. This is further
framed within the wider context of competing and conflicting
demands on higher education, exacerbated by the current worldwide
economic climate. There are now pressures on students to develop
their employability skills as well as their capacity to engage with
global issues such as behavioural change in the light of
environmental concerns. It is argued that these pressures, in effect,
lead to a form of personalization that is concerned with how
graduates develop their sense of identity as something that is
engineered and re-engineered to meet these demands.
Abstract: Process improvements have drawn much attention in
practical software engineering. The capability maturity levels from
CMMI have become an important index to assess a software company-s
software engineering capability. However, in countries like
Taiwan, customers often have no choices but to deal with vendors that
are not CMMI prepared or qualified. We call these vendors maturitylevel-
1 (ML1) vendors. In this paper, we describe our experience
from consulting an e-school project. We propose an approach to help
our client tackle the ML1 vendors. Through our system analysis, we
produce a design. This design is suggested to be used as part of
contract and a blueprint to guide the implementation.
Abstract: The network of delivering commodities has been an important design problem in our daily lives and many transportation applications. The delivery performance is evaluated based on the system reliability of delivering commodities from a source node to a sink node in the network. The system reliability is thus maximized to find the optimal routing. However, the design problem is not simple because (1) each path segment has randomly distributed attributes; (2) there are multiple commodities that consume various path capacities; (3) the optimal routing must successfully complete the delivery process within the allowable time constraints. In this paper, we want to focus on the design optimization of the Multi-State Flow Network (MSFN) for multiple commodities. We propose an efficient approach to evaluate the system reliability in the MSFN with respect to randomly distributed path attributes and find the optimal routing subject to the allowable time constraints. The delivery rates, also known as delivery currents, of the path segments are evaluated and the minimal-current arcs are eliminated to reduce the complexity of the MSFN. Accordingly, the correct optimal routing is found and the worst-case reliability is evaluated. It has been shown that the reliability of the optimal routing is at least higher than worst-case measure. Two benchmark examples are utilized to demonstrate the proposed method. The comparisons between the original and the reduced networks show that the proposed method is very efficient.
Abstract: A bird strike can cause damage to stationary and
rotating aircraft engine parts, especially the engine fan. This paper
presents a bird strike simulated by blocking four stator blade
passages. It includes the numerical results of the unsteady lowfrequency
aerodynamic forces and the aeroelastic behaviour caused
by a non-symmetric upstream flow affecting the first two rotor blade
stages in the axial-compressor of a jet engine. The obtained results
show that disturbances in the engine inlet strongly influence the level
of unsteady forces acting on the rotor blades. With a partially
blocked inlet the whole spectrum of low-frequency harmonics is
observed. Such harmonics can lead to rotor blade damage. The lowfrequency
amplitudes are higher in the first stage rotor blades than in
the second stage. In both rotor blades stages flutter appeared as a
result of bird strike.
Abstract: Gaharu that produced by Aquilaria spp. is classified as
one of the most valuable forest products traded internationally as it is
very resinous, fragrant and highly valuable heartwood. Gaharu has
been widely used in aromatheraphy, medicine, perfume and religious
practices. This work aimed to determine the factors affecting solid
liquid extraction of gaharu oil using hexane as solvent under
experimental condition. The kinetics of extraction was assumed and
verified based on a second-order mechanism. The effect of three
main factors, which were temperature, reaction time and solvent to
solid ratio were investigated to achieve maximum oil yield. The
optimum condition were found at temperature 65°C, 9 hours reaction
time and solvent to solid ratio of 12:1 with 14.5% oil yield. The
kinetics experimental data agrees and well fitted with the second
order extraction model. The initial extraction rate (h) was 0.0115
gmL-1min-1; the extraction capacity (Cs) was 1.282gmL-1; the second
order extraction constant (k) was 0.007 mLg-1min-1 and coefficient of
determination, R2 was 0.945.
Abstract: Recent years have instance that there is a invigoration
of interest in drug discovery from medicinal plants for the support of
health in all parts of the world . This study was designed to examine
the in vitro antimicrobial activities of the flowers and leaves
methanolic and ethanolic extracts of Chenopodium album L.
Chenopodium album Linn. flowers and leaves were collected from
East Esfahan, Iran. The effects of methanolic and ethanolic extracts
were tested against 4 bacterial strains by using disc,well-diffusion
method. Results showed that flowers and leaves methanolic and
ethanolic extracts of C.album don-t have any activity against the
selected bacterial strains. Our study has indicated that ,there are
effective different factors on antimicrobial properties of plant extracts