| A Novel Discrete Multi-Tone Constellation Algorithm |
| Posted on 06 October, 2009 |
In this study, a novel constellation algorithm for application in Discrete Multi Tone (DMT) modulation is presented. As the signal space diagram obtained is similar to snail, we have called the resulting modulation scheme as Snail Shift Keying (SSK), whose major property is its non-symmetric configuration where demands of subscribers can be prioritized conveniently. Quadrature Amplitude Modulation (QAM) and SSK, with the same power, have been applied to the DMT system with AWGN channels. Compared to a well-known QAM modulation scheme, based on the simulation results, the constellation algorithm presented has an improved Bit Error Rate (BER) performance with the same complexity in implementation. |
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| Analysis of the Relationship Between Eating Attitudes and Body Shape in Female Students |
| Posted on 06 October, 2009 |
This study aims at investigating the relationship between
eating attitudes and body image dissatisfaction. Among the female students
of psychology from Shahid Chamran University of Ahvaz, during 2008, 140
students were selected through random sampling. This research was conducted
in a field work fashion using the Eating Attitudes Test (EAT) and the
Body Shape Questionnaire (BSQ). The data collected were analyzed using
correlational statistics. Results suggested that there is a significant
positive correlation between the eating attitudes and body image dissatisfaction.
Thus, students who are overly dissatisfied with their body shape are at
a higher risk for an eating disorder. |
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| Comparing Achievement Goal Orientations of Iranian Gifted and Nongifted Schoolchildren |
| Posted on 06 October, 2009 |
This study was designed to compare achievement goal orientations of gifted and nongifted students. The 512 students in secondary school, including 262 nongifted students and 250 gifted students, responded to the achievement goal questionnaire. Analysis indicated that nongifted students scored significantly higher than gifted students on mastery goal orientation (F (1, 464) = 30.69, p<0.0001). Within groups analysis showed gifted students, as well as nongifted students more significantly use of performance-approach goals than mastery and performance-avoidance goals. Results are discussed with respect to general theoretical implications and context of Iranian educational system. |
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| The Use of Project Management Software in Construction Industry |
| Posted on 06 October, 2009 |
This research summarizes a study that was performed
on the construction industry in Iraq related to the use of Project Management
Software (PMS), its applicability and acceptance in the execution of todays
constructed projects. The data were collected from project management
professionals that yielded 31% response. The major findings concerning
software use over time, reasons for use/nonuse PMS, analytical technique
usage and software development are described. The results indicate that
construction professionals have different characteristics, needs and preferences.
The study shows that construction professionals are more experienced and
educated, they tend to work on fewer projects with larger numbers of activities
and they are more likely to use Primavera Project Plan (P3) than Microsoft
Project. Construction respondents revealed in heavy users of critical
path analysis for planning and control, resource scheduling for planning
and earned value analysis for control. The number of activities in a typical
project and the use of software for all active projects were the key determinants
of the usage of specific analytical techniques. These factors are also
significant determinants of the types of information entered and updated,
although the effect is weaker. To maximize the impact on practice, development
of new planning and control methods should include their integration into
project management software. In Iraq, substantial efforts have been made
in order to enhance the efficiency of software usage in construction industry. |
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| Effects of Fiber Type and Content on the Rutting Performance of Stone Matrix Asphalt |
| Posted on 06 October, 2009 |
The purpose of this study is to evaluate the effect
of fiber type and content on the rutting performance of stone matrix asphalt
mixtures. In this research two types, cellulose fibers (made in Iran and
Germany) and mineral fibers (rock wool) with various percentages (0.1-0.5%)
of the total weight of the Stone Matrix Asphalt (SMA) mixture were used
and after determining optimal bitumen content for each fiber percentage,
we examined their effect on SMA bulk specific gravity, Void in Mineral
Aggregate (VMA), void content, Marshall stability, Indirect Tensile Strength
(ITS) and flow parameters. Also results of dynamic creep test were used
as an indicator of rutting performance of SMA specimens. Results of the
laboratory tests showed that variation of fiber type and content can lead
to considerable changes in rutting performance of SMA. Specimens made
with 3% cellulose-GER (made in Germany) has resulted to highest value
of ITS and least permanent deformations. Also with considerations of potential
rutting, optimum percentage for each fiber type has been concluded. |
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| The Market Potential of Oil Palm Empty-Fruit Bunches Particleboard as a Furniture Material |
| Posted on 06 October, 2009 |
The study evaluated the consumer perceptions towards
particleboard as a premier furniture material. The data for this study
was collected from a questionnaire survey, completed by 500 buyers who
attended the international furniture fairs in Malaysia in 2008. Correlation
analysis showed that the success factors of particleboard as a furniture
stock are primarily its low cost and environmental friendly status. Further,
the study also revealed that the major advantages of particleboard made
from oil palm empty-fruit bunch (EFB), a potential substitute for the
conventional wood-based particleboard, are its comparatively lower cost
and greater environmental friendliness. Since, particleboard-based furniture
are perceived as being inexpensive and fragile, the choice of using particleboard
in furniture manufacturing is driven primarily on cost, rather than performance.
Therefore, the market potential of oil palm EFB particleboard is dependent
on its comparative cost, which could increase market share if the material
is available at a competitive price. |
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| Bearing Capacity of Stabilized Peat Column Using Hand Operated Cone Penetrometer |
| Posted on 06 October, 2009 |
The main objective of this study is to stabilize peat soil by deep mixing method using cement, sand, bentonite and calcium chloride as binder and to determine the effect on bearing capacity using proving ring hand operated cone penetrometer. Eight soil-binder columns have been constructed by mixing auger and prebored and premixing method using two different combination of binder. Bearing capacity of the columns has been evaluated by hand operated cone penetrometer after 1, 3, 7, 14 and 28 days of curing time. From the test results it was observed that bearing capacity of peat column increased considerably after stabilization. |
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| An Inverse Solution for 2D Electrical Impedance Tomography Based on Electrical Properties of Material Blocks |
| Posted on 06 October, 2009 |
The present study provides an inverse solution and analysis
on a new approach for Electrical Impedance Tomography (EIT) process as
Block Method in EIT. In this method, it is assumed that all of the particles
of each block have the same electrical properties (electrical conductivities).
This technique is used to enhance image resolution and also to improve
reconstruction algorithm. Although this method has been developed for
3D objects, in this study it is assumed that the subject has a (two-dimensional)
rectangular shape and is made of fixed size blocks. By considering the
previous conditions and computing relationship among currents, voltages
and electrical impedances of blocks, the required equations to solve the
problem is generated. Computer simulations show that employing the block
method in reconstruction algorithm results in more accurate identification. |
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| Study of Factors Affecting Mental Health |
| Posted on 06 October, 2009 |
The aim of this study is to investigate the simple and multiple relationships between role ambiguity, role conflict, role overload and mental health considering the moderating role of type A personality and sense of coherence. To this end correlation and regression analysis is utilized. Research sample includes 196 personnel working in Ahvaz Pipe-production factory during year 2007. Research results revealed that there is a significant relation between role ambiguity and mental health deficiency, but no one was found between role conflict and role overload and mental health deficiency; nevertheless, higher correlation level between role stressors and mental Health deficiency in low-level sense of coherence in comparison with high-level sense of coherence personnel was found. Also, a higher multiple correlations between role stressors and MH deficiency in personnel having further type A personality in comparison with personnel having not as much of mentioned group’s type A personality was observed. |
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| Creep Life Prediction of Inconel 738 Gas Turbine Blade |
| Posted on 06 October, 2009 |
The aim of this study is life prediction of IN738 LC
gas turbine blade via Larson- Miller parameter method and fulfillment
of some systematic metallographic, creep and hardness tests. Various calculative
methods of remaining life prediction have been considered and Larson-Miller
parameter method is used in order to predict remaining life of ABB-130
gas turbine blade. By investigation of the metallographic images it was
observed that the hardening phase (γ’) becomes bigger after
passing of a long time and under high temperature (780 °C) and has
been converted from cubic to almost spherical status. It results in a
decrease in the strength of the matrix and degradation of alloy’s
metallurgical properties and eventually generation of continuous carbides
in the grain boundaries, bigness and joining of γ’ particles,
grain boundary refining and generation of creep voids, all of which resulted
in satisfactorily calculation of remaining life time. |
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| A Novel Simulated Annealing Algorithm to Hybrid Flow Shops Scheduling with Sequence-Dependent Setup Times |
| Posted on 06 October, 2009 |
This study deals with the hybrid flow shop scheduling problems in which there are sequence-dependent setup times. This type of production system is found in industries such as chemical, textile, metallurgical, printed circuit board and automobile manufacture. This study describes a simulated annealing algorithm to the scheduling of a hybrid flow shop with sequence-dependent setup times. The obtained results are compared with those computed by RKGA presented previously. The superiority and effectiveness of our novel simulated annealing algorithm is inferred from all the results obtained in various situations. |
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| Effect of Orexin Infusion into Third Ventricle on the GnRH and LH Secretions in the Prepubertal Rat |
| Posted on 06 October, 2009 |
The goal of this study was to determine whether orexin
affects gonadotropin releasing hormone (GnRH) and Luteinizing Hormone
(LH) secretions in the prepubertal male and female rats. Forty prepubertal
rats were randomly divided into 4 groups. Animals in group 1 and 2 were
male and 3 and 4 were female. Animals in group 1 and 3 received infusions
of 1 μg orexin and group 2 and 4 received infusions of 2 μg
orexin into their third ventricle. Blood samples were collected from jugular
veins, every 30 min from 4 h before the first infusion of orexin until
4 h after the last orexin infusion. Infusions of 1 and 2 μg orexin
significantly (p<0.01) decreased the mean plasma concentrations and
pulse amplitudes of GnRH and LH in prepubertal female animal. Also, infusions
of 1 and 2 μg orexin significantly (p<0.05) decreased the mean
plasma concentrations and pulse amplitudes of GnRH and LH in prepubertal
male animal, but this decrease were lower in than female prepubertal rat.
Infusions of 1 and 2 μg orexin did not change the mean plasma concentrations
of FSH in the animal of all groups. Infusions of 1 and 2 μg, orexin
significantly (p<0.01) decreased the glucose levels of the prepubertal
female animals. The conclusion of this experiment indicated that orexin
may negatively affect the GnRH and LH in the prepubertal rats with negative
energy balance, but not in those with the positive energy balance. |
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| H∞ Controller for Consensus of Swarm Agents with Complete and Incomplete Communication Graphs |
| Posted on 06 October, 2009 |
This study mainly focuses on design method for H∞
controllers achieving consensus among the autonomous agents within swarm.
A robust controller is designed for the entire closed-loop system to achieve
consensus among the agents, while the non-consensus part is Lyapunov stable
based on the robust disturbance rejection. Two cases are considered. The
first one is that the agents in the swarm can interact with every other
agent when each agent can receive information from every other. The other
one is that the topology structure composed by the agents is fixed when
each agent in the swarm can only exchange information with some agents
but not all other agents. Simulation results demonstrate that designed
controller for the system can make the closed-loop system reach consensus
with non-consensus part be Lyapunov stable meeting the H∞
performance for disturbances attenuation. |
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| A Study on the Temporal and Local Distribution of Showers Generating Flood in Zolachai River Basin by Using Intensity-Duration-Frequency-Area Curves Relationships |
| Posted on 06 October, 2009 |
The present research sets out to study the temporal
and local distribution of showers generating flood in Zolachai river basin.
To carry out this research the rainfall data of 13 non-recording and recording
rain gauges over a 15-year statistical period (1986-2000) were employed.
The main aim of this study is to prepare Intensity-Duration-Frequency
and Duration-Area-Depth 2 curves and combine them in Intensity-Duration-Frequency-Area
curve forms in order to recognize and study rainfall parameters. To do
so, after selecting stormy days isohyets maps and Duration-Area-Depth
curves were drawn using Excel, Arcview and ArcGIS software. Also, to draw
Intensity-Duration-Frequency curves, hydrological software called Hyfa
was utilized. Finally, the above-mentioned curves were combined and Intensity-Duration-Frequency-Area
curves were drawn using Excel software for different return periods. In
this research four parameters including intensity-duration-frequency-area
were presented collectively, which had never been performed in the previous
researches on Zolachai river basin. Thus, this research was carried out
to raise the confidence of coefficient in water projects like construction
of dams and prediction of flood for Zolachai river basin. |
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| Air Gap Optimization of High-Speed Axial-Flux PM Generator |
| Posted on 06 October, 2009 |
The aim of this research is an air gap (between stator
and rotor) sensitivity study in the special High-Speed Axial Flux Generators
(HSAFG). This study firstly presents designing and modeling of this machine.
Then air gap impacts on the machine performance including three main performance
indexes of the machine i.e., efficiency, induced voltage and THD are considered
using a Matalab/Simulink program supported by finite elements field analysis.
At the end, according to this sensitivity analysis the lowest value of
the air gap is recommended for HSAFGs. |
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| Development of a Polypyrrole-Based Amperometric Phosphate Biosensor |
| Posted on 06 October, 2009 |
A biosensor is developed by co-entrapment of Purin Nucleoside
Phosphorylase (PNP) and xanthine oxidase (XOD) and potassium ferrocyanide
(K4Fe(CN)6 into a polypyrrole (PPy) film via galvanostatic
polymerisation of pyrrole. The optimum conditions for formation of the
PPy-PNP-XOD-Fe(CN)64- film are 0.3 M pyrrole. 6.2
U mL-1 XOD, 49 U mL-1 PNP, 40 mM K4Fe
(CN)6, polymerisation period of 200 sec and an applied current
density of 0.5 mA cm-2. The optimum potential for the amperometric
biosensing of phosphate was 200 mV vs Ag/AgCl (3 M KCl) in 0.05 M barbitone
buffer. The achievable linear concentration range was between 0.1 and
1 mM, while the minimum detectable amount was 10 μM. |
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| Itinerary Planning in Multimodal Urban Transportation Network |
| Posted on 06 October, 2009 |
This study describes scheduling an itinerary in multimodal
urban transportation network proposed to address the tour planning problem
which is usually required in tourism. The approach has utilized a genetic
algorithm to solve the problem aims at catching as many scores as possible
considering user preferences and restrictions of interested points. The
proposed approach has been developed for analyzing the transportation
network of Tehran and the experimental results are given in this study.
The results show the high capabilities of proposed methodology. |
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| Intelligent System for Continuous Gas Lift Operation and Design with Unlimited Gas Supply |
| Posted on 06 October, 2009 |
Gas lift is one of a number of processes used to artificially
lift oil or water from wells where there is insufficient reservoir pressure
to produce the well. The process involves injecting gas through the tubing-casing
annulus. Injected gas aerates the fluid to reduce its density; the formation
pressure is then able to lift the oil column and forces the fluid out
of the wellbore. Gas may be injected continuously or intermittently, depending
on the producing characteristics of the well and the arrangement of the
gas-lift equipment. To enhance the financial revenues this operation has
usually always been a subject for optimization to reach the most rewarding
design before its operational establishment. Evolutionary approaches have
recently been successfully applied to almost every aspect of engineering
problems. This study reviews the general facts and ideas related to the
gas lift and its optimization and further focus on the application and
evaluation of genetic programming for such a purpose. It has been concluded
that genetic programming is fully capable in aiding faster gas lift optimizations
while is also stable and applicable to a very broad range of operating
conditions. The merits and draw backs are finally compared with the neural
network approach. |
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| Newsboy Problem with Two Objectives, Fuzzy Costs and Total Discount Strategy |
| Posted on 06 October, 2009 |
This study extends Newsboy problem with multi-product multi-constraint and two objectives. Also there is total discount on the purchasing prices. The constraints are the warehouse capacity and the batch forms of the order placements. The first objective of this problem is to find the order quantities such that the expected profit is maximized and the second objective is maximizing the service rate. Moreover, the decision variables are integer. A formulation to the problem is presented and shown to be an integer nonlinear fuzzy programming model. Finally, an efficient hybrid algorithm fuzzy simulation, goal programming and particle swarm optimization is provided to solve the model and the results are shown with a numerical example. |
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| Issues of E-Banking Transaction: An Empirical Investigation on Malaysian Customers Perception |
| Posted on 06 October, 2009 |
This study investigated the determinant factors of consumers’
perception on E-banking transaction in Internet banking by Malaysian bank
consumers. The research framework was developed to testify the statistical
relationships between consumer perceptions and E-banking transaction.
Factor analysis was performed to extraction and make initial decision
on the number of factors underlying asset of measured variables of interest.
Thereafter, multiple regression was estimated to anticipate the effects
of the explanatory variables. This study showed that only secure transaction,
have significant impact on consumers perception about E-banking transaction.
Rest three factors regulatory framework, service quality and sufficient
mechanism negligible impact and hypothesis was rejected. This study offers
an insight into E-banking in Malaysia, which has not been previously been
investigated and much statistical significance makes this study a potential
cornerstone for future research. |
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| Numerical and Analytical Hydraulic Characterization of a Horizontal Single Joint Based on Radial Flow in Water Pressure Test |
| Posted on 06 October, 2009 |
In this research, the hydraulic characteristics of a
horizontal disc, which is assumed as a rock joint, have been studied analytically
and numerically with reference to radial flow occurred along a typical
water pressure test that is also known as Lugeon test. The hydraulic characteristics
such as Lugeon value, i.e., flowrate to hydrostatic pressure ratio, the
joint hydraulic aperture, inertia conditions, turbulence and laminar conditions
and the effect of relative roughness were investigated by use of well-known
hydraulic relations coincided by numerical analysis. The numerical results
were regarded as a verifier to evaluate the accuracy of empirical and
analytical relations. The comparison between analytical and numerical
results was based on Lu value which is recorded as the main result of
Lugeon test. The results show that the simplest equation (the Darcy equation
of radial flow) demonstrates the closer estimation to numerical one, in
comparison with other analytical and empirical equations. Also, the Lugeon
test must be considered as a single-well test and it could just identify
a combination of some hydraulic parameters. A practical procedure is finally
presented to calculate the possible hydraulic characteristics of tested
section in the borehole according to Water Pressure test. |
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| Application of an Optimum Design of Cooling Water System by Regeneration Concept and Pinch Technology for Water and Energy Conservation |
| Posted on 06 October, 2009 |
In this study, using a combination of Pinch Technology
and Mathematical Programming, a new technique is presented in order to
grass-root design for a cooling water system to achieve minimum total
annual cost. The presented technique is further improved by using patterns
from the concept of regeneration recycling in water systems; in a sense
that cooling water is regenerated locally by an air cooler. Moreover,
in the proposed method, optimum design of cooling tower has been achieved
through a mathematical model. Related coding in MATLAB version 7.3 was
used for the illustrative example to get optimal values in the proposed
cooling water design method computations. The result of the recently introduced
design methodology was compared with the conventional and Kim and Smith
design methods. The outcomes indicate that by using this new design method,
more water and energy can be saved and a lower level of total annual cost
can be reached. |
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| Amend Importance-Performance Analysis Method with Kano’s Model
and DEMATEL |
| Posted on 06 October, 2009 |
The purpose of this study was to set up new decision
making analysis methodology, KD-IPA, to assist enterprises in establishing
market strategy to win orders. Traditional Importance-Performance Analysis
(IPA) implies important assumptions: (1) performance and customer satisfaction
is a linear relationship and (2) the variables are independent and have
no causal relationship. If the quality characteristics do not meet the
abovementioned assumptions, the traditional IPA will not be able to analyze
the priority orders of importance and improvement accurately and results
in wrong decision-making. Therefore, the study integrated Kanos
Model and Decision Making Trial and Evaluation Laboratory (DEMATEL), to
establish a new methodology KD-IPA. The KD-IPA considers the nonlinear
impact of quality characteristics and the casual relationship between
the quality characteristics, which not only increase the effectiveness
and accuracy of IPA, but also maintain the ability to easily understand
the decision making model of the traditional IPA. The study adopted Taiwans
air-conditioner technology industry as the study case to explain the application
and effectiveness of KD-IPA methodology. In the case, the organization
has decided to strengthen the order-winner criteria delivery speed and
design for adopting differentiation strategy to segment the market. In
addition, quality conformance has the greatest increased satisfaction
effectiveness; therefore, it should be improved and used to increase the
market competitiveness. |
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| Endurance Time Method-Application in Nonlinear Seismic Analysis of Single Degree of Freedom Systems |
| Posted on 06 October, 2009 |
Endurance Time (ET) method has been introduced as a
time-history based dynamic analysis procedure. In this method structures
are subjected to a gradually intensifying acceleration function. Performance
of the structures is assessed based on the length of the time interval
that they can satisfy required performance objectives. In this study,
some fundamental concepts of ET method are explained and the potentials
and limitations of this procedure in nonlinear seismic analysis of SDOF
structures are investigated. A numerical optimization procedure for generating
ET acceleration functions that are compatible with ground motions are
explained. Results of ET analysis for inelastic SDOF systems are compared
with ground motions analysis results for different strength ratios, ductilities
and damping ratios. The accuracy of ET method in predicting the response
of SDOF systems with stiffness degradation and strength deterioration
is also investigated Application of ET method in performance based earthquake
engineering is described by an example of a single degree of freedom system.
The results show that the approximations of ET method are in good agreement
with the exact response history results of the similar ground motions
for different nonlinear systems. It is shown that ET acceleration functions
optimized in linear range considering long periods can be used in nonlinear
analysis with reasonable accuracy. |
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| Hydraulic (Flow) Unit Determination and Permeability Prediction: A Case Study of Block Shen-95, Liaohe Oilfield, North-East China |
| Posted on 06 October, 2009 |
This study analyzes three prediction approaches of the Bayesian method for predicting Hydraulic Unit (HU) and consequently predicts permeability for Block Shen-95. These approaches are intersection of multiple well-logs, independent mulitple well-logs and mutually exclusive multiple well-logs. In this study, HU was delineated to efficiently compute permeability and served as the building block of structural model for enhanced simulation study. HU is defined by the flow zone indicator concept from the modified Kozeny-Carmen equation. The Bayesian method was used to predict HU at uncored wells. This is done by first constructing a probability database through the integration of established HU and well-log responses at cored wells. HU is then inferred from the database using well-log responses. By comparison, estimated permeability from predicted HU gave an overall improved permeability match to that of traditional statistical methods. More so, mutually exclusive multiple well-logs proved more favourable. The highlight is that significant relationship exists by integrating reservoir performance with HU distribution indicating that reasonable prediction was obtained at uncored wells from the use of the mutually exclusive approach. The distribution was made possible by interwell HU correlation using depositional cycles as a framework but with modification. This integration step qualitatively examines prediction accuracy. |
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