Abstract: There are several ways of improving the performance of a vapor compression refrigeration cycle. Use of an ejector as expansion device is one of the alternative ways. The present paper aims at evaluate the performance improvement of a vapor compression refrigeration cycle under a wide range of operating conditions. A numerical model is developed and a parametric study of important parameters such as condensation (30-50°C) and evaporation temperatures (-20-5°C), nozzle and diffuser efficiencies (0.75-0.95), subcooling and superheating degrees (0-15K) are investigated. The model verification gives a good agreement with the literature data. The simulation results revealed that condensation temperature has the highest effect (129%) on the performance improvement ratio while superheating has the lowest one (6.2%). Among ejector efficiencies, the diffuser efficiency has a significant effect on the COP of ejector expansion refrigeration cycle. The COP improvement percentage decreases from 10.9% to 4.6% as subcooling degrees increases by 15K.
Abstract: Orthogonal Frequency Division Multiplexing (OFDM) is one of the techniques for high speed data rate communication with main consideration for 4G and 5G systems. In OFDM, there are several mapping schemes which provide a way of parallel transmission. In this paper, comparisons of mapping schemes used by some standards have been made and also has been discussed about the performance of the non-conventional modulation technique. The Comparisons of Bit Error Rate (BER) performances for conventional and non-conventional modulation schemes have been done using MATLAB software. Mentioned schemes used in OFDM system can be selected on the basis of the requirement of power or spectrum efficiency and BER analysis.
Abstract: Bumpers play an important role in preventing the
impact energy from being transferred to the automobile and
passengers. Saving the impact energy in the bumper to be released in
the environment reduces the damages of the automobile and
passengers.
The goal of this paper is to design a bumper with minimum weight
by employing the Glass Material Thermoplastic (GMT) materials.
This bumper either absorbs the impact energy with its deformation or
transfers it perpendicular to the impact direction.
To reach this aim, a mechanism is designed to convert about 80%
of the kinetic impact energy to the spring potential energy and
release it to the environment in the low impact velocity according to
American standard1. In addition, since the residual kinetic energy
will be damped with the infinitesimal elastic deformation of the
bumper elements, the passengers will not sense any impact. It should
be noted that in this paper, modeling, solving and result-s analysis
are done in CATIA, LS-DYNA and ANSYS V8.0 software
respectively.
Abstract: This paper presents a wavelet transform and Support
Vector Machine (SVM) based algorithm for estimating fault location
on transmission lines. The Discrete wavelet transform (DWT) is used
for data pre-processing and this data are used for training and testing
SVM. Five types of mother wavelet are used for signal processing to
identify a suitable wavelet family that is more appropriate for use in
estimating fault location. The results demonstrated the ability of SVM
to generalize the situation from the provided patterns and to
accurately estimate the location of faults with varying fault resistance.
Abstract: Value engineering is an efficacious contraption for
administrators to make up their minds. Value perusals proffer the
gaffers a suitable instrument to decrease the expenditures of the life
span, quality amelioration, structural improvement, curtailment of the
construction schedule, longevity prolongation or a merging of the
aforementioned cases. Subjecting organizers to pressures on one
hand and their accountability towards their pertinent fields together
with inherent risks and ambiguities of other options on the other hand
set some comptrollers in a dilemma utilization of risk management
and the value engineering in projects manipulation with regard to
complexities of implementing projects can be wielded as a
contraption to identify and efface each item which wreaks
unnecessary expenses and time squandering sans inflicting any
damages upon the essential project applications. Of course It should
be noted that implementation of risk management and value
engineering with regard to the betterment of efficiency and functions
may lead to the project implementation timing elongation. Here time
revamping does not refer to time diminishing in the whole cases. his
article deals with risk and value engineering conceptualizations at
first. The germane reverberations effectuated due to its execution in
Iran Khodro Corporation are regarded together with the joint features
and amalgamation of the aforesaid entia; hence the proposed
blueprint is submitted to be taken advantage of in engineering and
industrial projects including Iran Khodro Corporation.
Abstract: This paper presents a 2-D hydrodynamic model of the ablated plasma when irradiating a 50 μm Al solid target with a single pulsed ion beam. The Lagrange method is used to solve the moving fluid for the ablated plasma production and formation mechanism. In the calculations, a 10-ns-single-pulsed of ion beam with a total energy density of 120 J/cm2, is used. The results show that the ablated plasma was formed after 2 ns of ion beam irradiation and it started to expand right after 4-6 ns. In addition, the 2-D model give a better understanding of pulsed ion beam-solid target ablated plasma production and expansion process clearer.
Abstract: Text similarity measurement is a fundamental issue in
many textual applications such as document clustering, classification,
summarization and question answering. However, prevailing approaches
based on Vector Space Model (VSM) more or less suffer
from the limitation of Bag of Words (BOW), which ignores the semantic
relationship among words. Enriching document representation
with background knowledge from Wikipedia is proven to be an effective
way to solve this problem, but most existing methods still
cannot avoid similar flaws of BOW in a new vector space. In this
paper, we propose a novel text similarity measurement which goes
beyond VSM and can find semantic affinity between documents.
Specifically, it is a unified graph model that exploits Wikipedia as
background knowledge and synthesizes both document representation
and similarity computation. The experimental results on two different
datasets show that our approach significantly improves VSM-based
methods in both text clustering and classification.
Abstract: Nowadays, the importance of energy saving is clearance to everyone. By attention to increasing price of fuels and also the problems of environment pollutions, there are the most efforts for using fuels littler and more optimum in everywhere. This essay studies optimizing of gas consumption in gas-burner space heaters. In oven of each gas-burner space heaters there is two snags to prevent the hot air (the result of combustion of natural gas) to go out of oven of the gas-burner space heaters directly without delivering its heat to the space of favorite environment like a room. These snags cause a excess circulating that helps hot air deliver its heat to the space of favorite environment. It means the exhaust air temperature will be decreased then when there are no snags. This is the aim of this essay to use maximum potential energy of the natural gas to make heat. In this study, by the help of a finite volume software (FLUENT) consumption of the gas-burner space heaters is simulated and optimized. At the end of this writing, by comparing the results of software and experimental results, it will be proved the authenticity of this method.
Abstract: Breast cancer is one of the most frequent occurring cancers in women throughout the world including U.K. The grading of this cancer plays a vital role in the prognosis of the disease. In this paper we present an overview of the use of advanced computational method of fuzzy inference system as a tool for the automation of breast cancer grading. A new spectral data set obtained from Fourier Transform Infrared Spectroscopy (FTIR) of cancer patients has been used for this study. The future work outlines the potential areas of fuzzy systems that can be used for the automation of breast cancer grading.
Abstract: This paper analyzes the effect of a single uniform accounting rule on reporting quality by investigating the influence of IFRS on earnings management. This paper examines whether earnings management is reduced after IFRS adoption through the use of “loss avoidance thresholds”, a method that has been verified in earlier studies. This paper concentrates on two European countries: one that represents the continental code law tradition with weak protection of investors (France) and one that represents the Anglo-American common law tradition, which typically implies a strong enforcement system (the United Kingdom).
The research investigates a sample of 526 companies (6822 firm-year observations) during the years 2000 – 2013. The results are different for the two jurisdictions. This study demonstrates that a single set of accounting standards contributes to better reporting quality and reduces the pervasiveness of earnings management in France. In contrast, there is no evidence that a reduction in earnings management followed the implementation of IFRS in the United Kingdom. Due to the fact that IFRS benefit France but not the United Kingdom, other political and economic factors, such legal system or capital market strength, must play a significant role in influencing the comparability and transparency cross-border companies’ financial statements. Overall, the result suggests that IFRS moderately contribute to the accounting quality of reported financial statements and bring benefit for stakeholders, though the role played by other economic factors cannot be discounted.
Abstract: In this work, the effects of scale on thermal behavior of the slab in a walking-beam type reheating furnace is studied by considering scale formation and growth in a furnace environment. Also, mathematical heat transfer model to predict the thermal radiation in a complex shaped reheating furnace with slab and skid buttons is developed with combined nongray WSGGM and blocked-off solution procedure. The model can attack the heat flux distribution within the furnace and the temperature distribution in the slab throughout the reheating furnace process by considering the heat exchange between the slab and its surroundings, including the radiant heat transfer among the slabs, the skids, the hot combustion gases and the furnace wall as well as the gas convective heat transfer in the furnace. With the introduction of the mathematical formulations validation of the present numerical model is conducted by calculating two example problems of blocked-off and nongray gas radiative heat transfer. After discussing the formation and growth of the scale on the slab surface, slab heating characteristics with scale is investigated in terms of temperature rise with time.
Abstract: Cryo-electron microscopy (CEM) in combination with
single particle analysis (SPA) is a widely used technique for
elucidating structural details of macromolecular assemblies at closeto-
atomic resolutions. However, development of automated software
for SPA processing is still vital since thousands to millions of
individual particle images need to be processed. Here, we present our
workflow for automated particle picking. Our approach integrates
peak shape analysis to the classical correlation and an iterative
approach to separate macromolecules and background by
classification. This particle selection workflow furthermore provides
a robust means for SPA with little user interaction. Processing
simulated and experimental data assesses performance of the
presented tools.
Abstract: A plausible architecture of an ancient genetic code is derived from an extended base triplet vector space over the Galois field of the extended base alphabet {D, G, A, U, C}, where the letter D represent one or more hypothetical bases with unspecific pairing. We hypothesized that the high degeneration of a primeval genetic code with five bases and the gradual origin and improvements of a primitive DNA repair system could make possible the transition from the ancient to the modern genetic code. Our results suggest that the Watson-Crick base pairing and the non-specific base pairing of the hypothetical ancestral base D used to define the sum and product operations are enough features to determine the coding constraints of the primeval and the modern genetic code, as well as the transition from the former to the later. Geometrical and algebraic properties of this vector space reveal that the present codon assignment of the standard genetic code could be induced from a primeval codon assignment. Besides, the Fourier spectrum of the extended DNA genome sequences derived from the multiple sequence alignment suggests that the called period-3 property of the present coding DNA sequences could also exist in the ancient coding DNA sequences.
Abstract: Efficient storage, transmission and use of video information are key requirements in many multimedia applications currently being addressed by MPEG-4. To fulfill these requirements, a new approach for representing video information which relies on an object-based representation, has been adopted. Therefore, objectbased watermarking schemes are needed for copyright protection. This paper proposes a novel blind object watermarking scheme for images and video using the in place lifting shape adaptive-discrete wavelet transform (SA-DWT). In order to make the watermark robust and transparent, the watermark is embedded in the average of wavelet blocks using the visual model based on the human visual system. Wavelet coefficients n least significant bits (LSBs) are adjusted in concert with the average. Simulation results shows that the proposed watermarking scheme is perceptually invisible and robust against many attacks such as lossy image/video compression (e.g. JPEG, JPEG2000 and MPEG-4), scaling, adding noise, filtering, etc.
Abstract: Spam mails are unwanted mails sent to large number
of users. Spam mails not only consume the network resources, but
cause security threats as well. This paper proposes an efficient
technique to detect, and to prevent spam mail in the sender side rather
than the receiver side. This technique is based on a counter set on the
sender server. When a mail is transmitted to the server, the mail server
checks the number of the recipients based on its counter policy. The
counter policy performed by the mail server is based on some
pre-defined criteria. When the number of recipients exceeds the
counter policy, the mail server discontinues the rest of the process, and
sends a failure mail to sender of the mail; otherwise the mail is
transmitted through the network. By using this technique, the usage of
network resources such as bandwidth, and memory is preserved. The
simulation results in real network show that when the counter is set on
the sender side, the time required for spam mail detection is 100 times
faster than the time the counter is set on the receiver side, and the
network resources are preserved largely compared with other
anti-spam mail techniques in the receiver side.
Abstract: Mobile agents are a powerful approach to develop distributed systems since they migrate to hosts on which they have the resources to execute individual tasks. In a dynamic environment like a peer-to-peer network, Agents have to be generated frequently and dispatched to the network. Thus they will certainly consume a certain amount of bandwidth of each link in the network if there are too many agents migration through one or several links at the same time, they will introduce too much transferring overhead to the links eventually, these links will be busy and indirectly block the network traffic, therefore, there is a need of developing routing algorithms that consider about traffic load. In this paper we seek to create cooperation between a probabilistic manner according to the quality measure of the network traffic situation and the agent's migration decision making to the next hop based on decision tree learning algorithms.
Abstract: Nowadays, financial and economic crises are growing
more and reach more countries and sectors. These events have, as a
result, a considerable impact on the activities of the firms which think
unstable and in danger.
But besides this heavy uncertainty which weighs on the different
firms, the family firm, object of our research, is not only confronted
with these external difficulties but also with an internal challenge and
of size: that of transmission. Indeed, the transmission of an
organization from one generation to another can succeed as it can
fail; leaving considerable damage.
Our research registers as part of these problems since we tried to
understand relation between the behavior of two main actors of the
process of succession, predecessor and successor; and the success of
transmission.
Abstract: In this paper we present the PC cluster built at R.V.
College of Engineering (with great help from the Department of
Computer Science and Electrical Engineering). The structure of the
cluster is described and the performance is evaluated by rendering of
complex 3D Persistence of Vision (POV) images by the Ray-Tracing
algorithm. Here, we propose an unexampled method to render such
images, distributedly on a low cost scalable.
Abstract: This paper presents a comparison between Spectrum-
Sliced Wavelength Division Multiplexing (SS-WDM) and Spectrum
Amplitude Coding Optical Code Division Multiple Access (SAC
Optical CDMA) systems for different light sources. The performance
of the system is shown in the simulated results of the bit error rate
(BER) and the eye diagram of both systems. The comparison results
indicate that the Multiple Access Interference (MAI) effects have a
significant impact on SS-WDM over SAC Optical CDMA systems.
Finally, in terms of spectral efficiency at constant BER of 10-12, SSWDM
offers higher spectral efficiency than optical CDMA since no
bandwidth expansion in needed.
Abstract: Generally, in order to create 3D sound using binaural
systems, we use head related transfer functions (HRTF) including the
information of sounds which is arrived to our ears. But it can decline
some three-dimensional effects in the area of a cone of confusion
between front and back directions, because of the characteristics of
HRTF.
In this paper, we propose a new method to use psychoacoustics
theory that reduces the confusion of sound image localization. In the
method, HRTF spectrum characteristic is enhanced by using the
energy ratio of the bark band. Informal listening tests show that the
proposed method improves the front-back sound localization
characteristics much better than the conventional methods