Abstract: Cs-type nanocomposite zeolite membrane was successfully synthesized on an alumina ceramic hollow fibre with a mean outer diameter of 1.7 mm; cesium cationic exchange test was carried out inside test module with mean wall thickness of 230 μm and an average crossing pore size smaller than 0.2 μm. Separation factor of n-butane/H2 obtained indicate that a relatively high quality closed to 20. Maxwell-Stefan modeling provides an equivalent thickness lower than 1 µm. To compare the difference an application to CO2/N2 separation has been achieved, reaching separation factors close to (4,18) before and after cation exchange on H-zeolite membrane formed within the pores of a ceramic alumina substrate.
Abstract: In the area of Human Resource Management, the trend is towards online exchange of information about human resources. For example, online applications for employment become standard and job offerings are posted in many job portals. However, there are too many job portals to monitor all of them if someone is interested in a new job. We developed a prototype for integrating information of different job portals into one meta-search engine. First, existing job portals were investigated and XML schema documents were derived automated from these portals. Second, translation rules for transforming each schema to a central HR-XML-conform schema were determined. The HR-XML-schema is used to build a form for searching jobs. The data supplied by a user in this form is now translated into queries for the different job portals. Each result obtained by a job portal is sent to the meta-search engine that ranks the result of all received job offers according to user's preferences.
Abstract: Using Turkish data, in this study it is investigated that
whether a firm’s ownership structure has an impact on its stock
prices after the crisis. A linear regression model is conducted on the
data of non-financial firms that are trading in Istanbul Stock
Exchange 100 Index (ISE 100) index. The findings show that, all
explanatory variables such as inside ownership, largest ownership,
concentrated ownership, foreign shareholders, family controlled and
dispersed ownership are not very important to explain stock prices
after the crisis. Family controlled firms and concentrated ownership
is positively related to stock price, dispersed ownership, largest
ownership, foreign shareholders, and inside ownership structures
have negative interaction between stock prices, but because of the p
value is not under the value of 0.05 this relation is not significant. In
addition, the analysis shows that, the shares of firms that have inside,
largest and dispersed ownership structure are outperform comparing
with the other firms. Furthermore, ownership concentrated firms
outperform to family controlled firms.
Abstract: Distant-talking voice-based HCI system suffers from
performance degradation due to mismatch between the acoustic
speech (runtime) and the acoustic model (training). Mismatch is
caused by the change in the power of the speech signal as observed at
the microphones. This change is greatly influenced by the change in
distance, affecting speech dynamics inside the room before reaching
the microphones. Moreover, as the speech signal is reflected, its
acoustical characteristic is also altered by the room properties. In
general, power mismatch due to distance is a complex problem. This
paper presents a novel approach in dealing with distance-induced
mismatch by intelligently sensing instantaneous voice power variation
and compensating model parameters. First, the distant-talking speech
signal is processed through microphone array processing, and the
corresponding distance information is extracted. Distance-sensitive
Gaussian Mixture Models (GMMs), pre-trained to capture both
speech power and room property are used to predict the optimal
distance of the speech source. Consequently, pre-computed statistic
priors corresponding to the optimal distance is selected to correct
the statistics of the generic model which was frozen during training.
Thus, model combinatorics are post-conditioned to match the power
of instantaneous speech acoustics at runtime. This results to an
improved likelihood in predicting the correct speech command at
farther distances. We experiment using real data recorded inside two
rooms. Experimental evaluation shows voice recognition performance
using our method is more robust to the change in distance compared
to the conventional approach. In our experiment, under the most
acoustically challenging environment (i.e., Room 2: 2.5 meters), our
method achieved 24.2% improvement in recognition performance
against the best-performing conventional method.
Abstract: The main objective of this study is to test the
relationship between numbers of variables representing the firm
characteristics (market-related variables) and the extent of voluntary
disclosure levels (forward-looking disclosure) in the annual reports of
Egyptian firms listed on the Egyptian Stock Exchange. The results
show that audit firm size is significantly positively correlated (in all
the three years) with the level of forward-looking disclosure.
However, industry type variable (which divided to: industries,
cement, construction, petrochemicals and services), is found being
insignificantly association with the level of forward-looking
information disclosed in the annual reports for all the three years.
Abstract: The aim of this paper is description of the notion of
the death for prisoners and the ways of deal with. They express
indifference, coldness, inability to accept the blame, they have no
shame and no empathy. Is it enough to perform acts verging on the
death. In this paper we described mechanisms and regularities of selfdestructive
behaviour in the view of the relevant literature? The
explanation of the phenomenon is of a biological and sociopsychological
nature. It must be clearly stated that all forms of selfdestructive
behaviour result from various impulses, conflicts and
deficits. That is why they should be treated differently in terms of
motivation and functions which they perform in a given group of
people. Behind self-destruction there seems to be a motivational
mechanism which forces prisoners to rebel and fight against the hated
law and penitentiary systems. The imprisoned believe that pain and
suffering inflicted on them by themselves are better than passive
acceptance of repression. The variety of self-destruction acts is wide,
and some of them take strange forms. We assume that a life-death
barrier is a kind of game for them. If they cannot change the
degrading situation, their life loses sense.
Abstract: In the present essay, a model of choice by actors is analysedby utilizing the theory of chaos to explain how change comes about. Then, by using ancient and modern sources of literature, the theory of the social contract is analysed as a historical phenomenon that first appeared during the period of Classical Greece. Then, based on the findings of this analysis, the practice of direct democracy and public choice in ancient Athens is analysed, through two historical cases: Eubulus and Lycurgus political program in the second half of the 4th century. The main finding of this research is that these policies can be interpreted as an implementation of a social contract, through which citizens were taking decisions based on rational choice according to economic considerations.
Abstract: We address the balancing problem of transfer lines in
this paper to find the optimal line balancing that minimizes the nonproductive
time. We focus on the tool change time and face
orientation change time both of which influence the makespane. We
consider machine capacity limitations and technological constraints
associated with the manufacturing process of auto cylinder heads.
The problem is represented by a mixed integer programming model
that aims at distributing the design features to workstations and
sequencing the machining processes at a minimum non-productive
time. The proposed model is solved by an algorithm established using
linearization schemes and Benders- decomposition approach. The
experiments show the efficiency of the algorithm in reaching the
exact solution of small and medium problem instances at reasonable
time.
Abstract: The data measurement of mean velocity has been
taken for the wake of single circular cylinder with three different diameters for two different velocities. The effects of change in
diameter and in velocity are studied in self-similar coordinate system.
The spatial variations of velocity defect and that of the half-width
have been investigated. The results are compared with those
published by H.Schlichting. In the normalized coordinates, it is also observed that all cases except for the first station are self-similar. By attention to self-similarity profiles of mean velocity, it is observed for all the cases at the each station curves tend to zero at a same point.
Abstract: The Proton Exchange Membrane Fuel Cell (PEMFC)
control system has an important effect on operation of cell.
Traditional controllers couldn-t lead to acceptable responses because
of time- change, long- hysteresis, uncertainty, strong- coupling and
nonlinear characteristics of PEMFCs, so an intelligent or adaptive
controller is needed. In this paper a neural network predictive
controller have been designed to control the voltage of at the
presence of fluctuations of temperature. The results of
implementation of this designed NN Predictive controller on a
dynamic electrochemical model of a small size 5 KW, PEM fuel cell
have been simulated by MATLAB/SIMULINK.
Abstract: In this paper, we consider Wiener nonlinear model for solid oxide fuel cell (SOFC). The Wiener model of the SOFC consists of a linear dynamic block and a static output non-linearity followed by the block, in which linear part is approximated by state-space model and the nonlinear part is identified by a polynomial form. To control the SOFC system, we have to consider various view points such as operating conditions, another constraint conditions, change of load current and so on. A change of load current is the significant one of these for good performance of the SOFC system. In order to keep the constant stack terminal voltage by changing load current, the nonlinear model predictive control (MPC) is proposed in this paper. After primary control method is designed to guarantee the fuel utilization as a proper constant, a nonlinear model predictive control based on the Wiener model is developed to control the stack terminal voltage of the SOFC system. Simulation results verify the possibility of the proposed Wiener model and MPC method to control of SOFC system.
Abstract: Groundwater resources in Arsanjan plain provide
water for agriculture, industry, and human consumption. Continued
agricultural development in this area needs to additional groundwater
resources for, particularly during of drought periods, and effects on
the quantity and quality of ground water available. The purpose of
this study is to evaluate water level changes in the aquifer of
Arsanjan plain in the Fars province in order to determine the areas of
greatest depletion and the causes of depletion. In this plain, farmers
and other users are pumping groundwater faster than its natural
replenishment rate, causing a continuous drop in groundwater tables
and depletion of this resource. In this research variation of
groundwater level, their effects and ways to help control groundwater
levels in aquifer of the Arsanjan plains were evaluated .Excessive
exploitation of groundwater in this aquifer caused the groundwater
levels fall too fast or to unacceptable levels. The average drawdown
of the groundwater level in this plain were 19.66 meters during
1996 to 2003.
Abstract: Application of projective geometry to the theory of two-ports and cascade circuits with a load change is considered. The equations linking the input and output of a two-port are interpreted as projective transformations which have the invariant as a cross-ratio of four points. This invariant has place for all regime parameters in all parts of a cascade circuit. This approach allows justifying the definition of a regime and its change, to calculate a circuit without explicitly finding the aparameters, to transmit accurately an analogue signal through the unstable two-port.
Abstract: Employee-s task performance has been recognized as a
core contributor to overall organizational effectiveness. Hence,
verifying the determinants of task performance is one of the most
important research issues. This study tests the influence of perceived
organizational support, abusive supervision, and exchange ideology
on employee-s task performance. We examined our hypotheses by
collecting self-reported data from 413 Korean employees in different
organizations. Our all hypotheses gained support from the results.
Implications for research and directions for future research are
discussed.
Abstract: Carbon nanotubes (CNTs) possess unique structural,
mechanical, thermal and electronic properties, and have been
proposed to be used for applications in many fields. However, to
reach the full potential of the CNTs, many problems still need to be
solved, including the development of an easy and effective
purification procedure, since synthesized CNTs contain impurities,
such as amorphous carbon, carbon nanoparticles and metal particles.
Different purification methods yield different CNT characteristics
and may be suitable for the production of different types of CNTs. In
this study, the effect of different purification chemicals on carbon
nanotube quality was investigated. CNTs were firstly synthesized by
chemical vapor deposition (CVD) of acetylene (C2H2) on a
magnesium oxide (MgO) powder impregnated with an iron nitrate
(Fe(NO3)3·9H2O) solution. The synthesis parameters were selected
as: the synthesis temperature of 800°C, the iron content in the
precursor of 5% and the synthesis time of 30 min. The liquid phase
oxidation method was applied for the purification of the synthesized
CNT materials. Three different acid chemicals (HNO3, H2SO4, and
HCl) were used in the removal of the metal catalysts from the
synthesized CNT material to investigate the possible effects of each
acid solution to the purification step. Purification experiments were
carried out at two different temperatures (75 and 120 °C), two
different acid concentrations (3 and 6 M) and for three different time
intervals (6, 8 and 15 h). A 30% H2O2 : 3M HCl (1:1 v%) solution
was also used in the purification step to remove both the metal
catalysts and the amorphous carbon. The purifications using this
solution were performed at the temperature of 75°C for 8 hours.
Purification efficiencies at different conditions were evaluated by
thermogravimetric analysis. Thermal and electrical properties of
CNTs were also determined. It was found that the obtained electrical
conductivity values for the carbon nanotubes were typical for organic
semiconductor materials and thermal stabilities were changed
depending on the purification chemicals.
Abstract: Double-diffusive steady convection in a partially
porous cavity with partially permeable walls and under the combined
buoyancy effects of thermal and mass diffusion was analysed
numerically using finite volume method.
The top wall is well insulated and impermeable while the bottom
surface is partially well insulated and impermeable and partially
submitted to constant temperature T1 and concentration C1. Constant
equal temperature T2 and concentration C2 are imposed along the
vertical surfaces of the enclosure. Mass suction/injection and
injection/suction are respectively considered at the bottom of the
porous centred partition and at one of the vertical walls.
Heat and mass transfer characteristics as streamlines and average
Nusselt numbers and Sherwood numbers were discussed for different
values of buoyancy ratio, Rayleigh number, and injection/suction
coefficient.
It is especially noted that increasing the injection factor
disadvantages the exchanges in the case of the injection while the
transfer is augmented in case of suction. On the other hand, a critical
value of the buoyancy ratio was highlighted for which heat and mass
transfers are minimized.
Abstract: A model of a system concerning one species of demersal
(inshore) fish and one of pelagic (offshore) fish undergoing fishing
restricted by marine protected areas is proposed in this paper. This
setup was based on the FISH-BE model applied to the Tabina fishery
in Zamboanga del Sur, Philippines. The components of the model
equations have been adapted from widely-accepted mechanisms in
population dynamics. The model employs Gompertz-s law of growth
and interaction on each type of protected and unprotected subpopulation.
Exchange coefficients between protected and unprotected
areas were assumed to be proportional to the relative area of the
entry region. Fishing harvests were assumed to be proportional to
both the number of fishers and the number of unprotected fish. An
extra term was included for the pelagic population to allow for the
exchange between the unprotected area and the outside environment.
The systems were found to be bounded for all parameter values. The
equations for the steady state were unsolvable analytically but the
existence and uniqueness of non-zero steady states can be proven.
Plots also show that an MPA size yielding the maximum steady state
of the unprotected population can be found. All steady states were
found to be globally asymptotically stable for the entire range of
parameter values.
Abstract: Salary risk and demographic risk have been identified
as main risks in analyzing pension expenditure particularly in
Defined Benefit pension plan. Therefore, public pension plan in
Malaysia is studied to analyze pension expenditure due to salary and
demographic risk. Through the literature review and interview session
with several officers in public sector, factors affecting pension
expenditure are determined. Then, the inter-relationships between
these factors are analyzed through causal loop diagram. The System
Dynamics model is later developed using iThink software to show how
demographic and salary changes affect the pension expenditure. Then, by
using actual data, the impact of different policy scenarios on pension
expenditure is analyzed. It is shown that dynamics simulation model of
pension expenditure is useful to evaluate the impact of changes and
policy decisions on risk particularly involving demographic and salary risk.
Abstract: Degradation of polymeric insulation systems of
electrical equipments increases the space charge density and the
concentration of electrical dipoles. By consequence, the maximum
values and the slopes of absorption/resorption (A/R) currents can
change with insulation systems ageing. In this paper, an analysis of
the nature of the A/R currents and the importance of their
components, especially the polarization current and the current given
by the space charge, is presented. The experimental study concerns
the A/R currents measurements of plane samples (made from
CALMICAGLAS tapes), virgin and thermally accelerated aged. The
obtained results show that the ageing process produces an increase of
the values and a decrease of shapes of the A/R currents. Finally, the
possibility of estimating insulations ageing state and lifetime from
A/R currents measurements is discussed.
Abstract: A lot of computer-based methods have been developed
to assess the evacuation capability (EC) of high-rise buildings.
Because softwares are time-consuming and not proper for on scene
applications, we adopted two methods, fuzzy analytic hierarchy
process (FAHP) and technique for order preference by similarity to an
ideal solution (TOPSIS), for EC assessment of a high-rise building in
Jinan. The EC scores obtained with the two methods and the
evacuation time acquired with Pathfinder 2009 for floors 47-60 of the
building were compared with each other. The results show that FAHP
performs better than TOPSIS for EC assessment of high-rise buildings,
especially in the aspect of dealing with the effect of occupant type and
distance to exit on EC, tackling complex problem with multi-level
structure of criteria, and requiring less amount of computation.
However, both FAHP and TOPSIS failed to appropriately handle the
situation where the exit width changes while occupants are few.