Abstract: In this paper, the application of thermal spray
coatings in high speed shafts by a revolution up to 23000 RPM
has been studied. Gas compressor shafts are worn in contact
zone with journal therefore will be undersized. Wear
mechanisms of compressor shaft were identified. The
predominant wear mechanism is abrasion wear. The worn
surface was coated by hard WC-Co cermets using high
velocity oxy fuel (HVOF) after preparation. The shafts were in
satisfactory service in 8000h period. The metallurgical and
Tribological studies has been made on the worn and coated
shaft using optical microscopy, scanning electron microscopy
(SEM) and X-ray diffraction.
Abstract: In Croatia, the majority of cultured marine fish species are reared in net cages. The intensive production of the fish in net cages may generate the considerable amount of bio waste and change water quality especially in enclosed and semi-enclosed coastal areas. The aim of this paper is to assess the potential impact of sea bass (Dicentrarchus labrax L.) cage farm on water quality. The weak relationship between food supply and water quality parameters (nutrient content and phytoplankton biomass) was found, but significant changes in oxygen saturation was observed in the cages during the warmer period of a year especially in the morning (occasionally it dropped below 70 %). Despite of, satisfactory results of water quality parameters, it is necessary to establish comprehensive monitoring process, especially to include quality assessment of fouling communities.
Abstract: Background, measuring an individual-s Health
Literacy is gaining attention, yet no appropriate instrument is available
in Taiwan. Measurement tools that were developed and used in
western countries may not be appropriate for use in Taiwan due to a
different language system. Purpose of this research was to develop a
Health Literacy measurement instrument specific for Taiwan adults.
Methods, several experts of clinic physicians; healthcare
administrators and scholars identified 125 common used health related
Chinese phrases from major medical knowledge sources that easy
accessible to the public. A five-point Likert scale is used to measure
the understanding level of the target population. Such measurement is
then used to compare with the correctness of their answers to a health
knowledge test for validation. Samples, samples under study were
purposefully taken from four groups of people in the northern
Pingtung, OPD patients, university students, community residents,
and casual visitors to the central park. A set of health knowledge index
with 10 questions is used to screen those false responses. A sample
size of 686 valid cases out of 776 was then included to construct this
scale. An independent t-test was used to examine each individual
phrase. The phrases with the highest significance are then identified
and retained to compose this scale. Result, a Taiwan Health Literacy
Scale (THLS) was finalized with 66 health-related phrases under nine
divisions. Cronbach-s alpha of each division is at a satisfactory level
of 89% and above. Conclusions, factors significantly differentiate the
levels of health literacy are education, female gender, age, family
members of stroke victims, experience with patient care, and
healthcare professionals in the initial application in this study..
Abstract: The Principal component regression (PCR) is a
combination of principal component analysis (PCA) and multiple linear regression (MLR). The objective of this paper is to revise the
use of PCR in shortwave near infrared (SWNIR) (750-1000nm) spectral analysis. The idea of PCR was explained mathematically and
implemented in the non-destructive assessment of the soluble solid
content (SSC) of pineapple based on SWNIR spectral data. PCR achieved satisfactory results in this application with root mean
squared error of calibration (RMSEC) of 0.7611 Brix°, coefficient of determination (R2) of 0.5865 and root mean squared error of crossvalidation
(RMSECV) of 0.8323 Brix° with principal components
(PCs) of 14.
Abstract: In many applications, magnetic suspension systems
are required to operate over large variations in air gap. As a result,
the nonlinearities inherent in most types of suspensions have a
significant impact on performance. Specifically, it may be difficult to
design a linear controller which gives satisfactory performance,
stability, and disturbance rejection over a wide range of operating
points. in this paper an optimal controller based on discontinuous
mathematical model of the system for an electromagnetic suspension
system which is applied in magnetic trains has been designed .
Simulations show that the new controller can adapt well to the
variance of suspension mass and gap, and keep its dynamic
performance, thus it is superior to the classic controller.
Abstract: Prediction of highly non linear behavior of suspended
sediment flow in rivers has prime importance in the field of water
resources engineering. In this study the predictive performance of
two Artificial Neural Networks (ANNs) namely, the Radial Basis
Function (RBF) Network and the Multi Layer Feed Forward (MLFF)
Network have been compared. Time series data of daily suspended
sediment discharge and water discharge at Pari River was used for
training and testing the networks. A number of statistical parameters
i.e. root mean square error (RMSE), mean absolute error (MAE),
coefficient of efficiency (CE) and coefficient of determination (R2)
were used for performance evaluation of the models. Both the models
produced satisfactory results and showed a good agreement between
the predicted and observed data. The RBF network model provided
slightly better results than the MLFF network model in predicting
suspended sediment discharge.
Abstract: In this paper, we show that the association of the PI
regulators for the speed and stator currents with a control strategy
using the linearization by state feedback for an induction machine
without speed sensor, and with an adaptation of the rotor resistance.
The rotor speed is estimated by using the model reference adaptive
system approach (MRAS). This method consists of using two
models: The first is the reference model and the second is an
adjustable one in which two components of the stator flux, obtained
from the measurement of the currents and stator voltages are
estimated. The estimated rotor speed is then obtained by canceling
the difference between stator-flux of the reference model and those
of the adjustable one. Satisfactory results of simulation are obtained
and discussed in this paper to highlight the proposed approach.
Abstract: Through inward perceptions, we intuitively expect
distributed software development to increase the risks associated with
achieving cost, schedule, and quality goals. To compound this
problem, agile software development (ASD) insists one of the main
ingredients of its success is cohesive communication attributed to
collocation of the development team. The following study identified
the degree of communication richness needed to achieve comparable
software quality (reduce pre-release defects) between distributed and
collocated teams. This paper explores the relevancy of
communication richness in various development phases and its
impact on quality. Through examination of a large distributed agile
development project, this investigation seeks to understand the levels
of communication required within each ASD phase to produce
comparable quality results achieved by collocated teams. Obviously,
a multitude of factors affects the outcome of software projects.
However, within distributed agile software development teams, the
mode of communication is one of the critical components required to
achieve team cohesiveness and effectiveness. As such, this study
constructs a distributed agile communication model (DAC-M) for
potential application to similar distributed agile development efforts
using the measurement of the suitable level of communication. The
results of the study show that less rich communication methods, in
the appropriate phase, might be satisfactory to achieve equivalent
quality in distributed ASD efforts.
Abstract: In this paper, an intelligent automatic parking control method is proposed. First, the dynamical equation of the rear parking control is derived. Then a fuzzy logic control is proposed to perform the parking planning process. Further, a rear neural network is proposed for the steering control. Through the simulations and experiments, the intelligent auto-parking mode controllers have been shown to achieve the demanded goals with satisfactory control performance and to guarantee the system robustness under parametric variations and external disturbances. To improve some shortcomings and limitations in conventional parking mode control and further to reduce consumption time and prime cost.
Abstract: Global approximation using metamodel for complex
mathematical function or computer model over a large variable
domain is often needed in sensibility analysis, computer simulation,
optimal control, and global design optimization of complex, multiphysics
systems. To overcome the limitations of the existing
response surface (RS), surrogate or metamodel modeling methods for
complex models over large variable domain, a new adaptive and
regressive RS modeling method using quadratic functions and local
area model improvement schemes is introduced. The method applies
an iterative and Latin hypercube sampling based RS update process,
divides the entire domain of design variables into multiple cells,
identifies rougher cells with large modeling error, and further divides
these cells along the roughest dimension direction. A small number
of additional sampling points from the original, expensive model are
added over the small and isolated rough cells to improve the RS
model locally until the model accuracy criteria are satisfied. The
method then combines local RS cells to regenerate the global RS
model with satisfactory accuracy. An effective RS cells sorting
algorithm is also introduced to improve the efficiency of model
evaluation. Benchmark tests are presented and use of the new
metamodeling method to replace complex hybrid electrical vehicle
powertrain performance model in vehicle design optimization and
optimal control are discussed.
Abstract: This study presents an investigation of
electrochemical variables and an application of the optimal
parameters in operating a continuous upflow electrocoagulation
reactor in removing dye. Direct red 23, which is azo-based, was used
as a representative of direct dyes. First, a batch mode was employed
to optimize the design parameters: electrode type, electrode distance,
current density and electrocoagulation time. The optimal parameters
were found to be iron anode, distance between electrodes of 8 mm
and current density of 30 A·m-2 with contact time of 5 min. The
performance of the continuous upflow reactor with these parameters
was satisfactory, with >95% color removal and energy consumption
in the order of 0.6-0.7 kWh·m-3.
Abstract: Paper deals with the topic of questions as important
components of information behavior in the school. By analyzing the
Corpus Schola2010, the state of contemporary education in terms of
questioning is proven unsatisfactory: 80% of the questions are asked
by teachers; most of teacher-s questions are asked at the beginning of
the first grade, than their number decreases and is settling down on
80±10 questions per lesson. The average number of questions within
one lesson per one pupil is generally less than one whole question.
The highest values are achieved in the first, sixth, eighth and tenth
grade,, i.e. in the transition years in which pupils are moving into
higher levels of education and every following year it declines. We
can state Czech school do not support questioning and question skill
of their pupils, thereby typical Czech schools are neglecting the
development of thinking, reasoning and cooperation of their pupils.
Abstract: Data clustering is an important data exploration
technique with many applications in data mining. The k-means
algorithm is well known for its efficiency in clustering large data
sets. However, this algorithm is suitable for spherical shaped clusters
of similar sizes and densities. The quality of the resulting clusters
decreases when the data set contains spherical shaped with large
variance in sizes. In this paper, we introduce a competent procedure
to overcome this problem. The proposed method is based on shifting
the center of the large cluster toward the small cluster, and recomputing
the membership of small cluster points, the experimental
results reveal that the proposed algorithm produces satisfactory
results.
Abstract: Riprap is mostly used to prevent erosion by flows
down the steep slopes in river engineering. A total of 53 stability tests
performed on angular riprap with a median stone size ranging from
15 to 278 mm and slope ranging from 1 to 40% are used in this study.
The existing equations for the prediction of medium size of angular
stones are checked for their accuracy using the available data.
Predictions of median size using these equations are not satisfactory
and results show deviation by more than ±20% from the observed
values. A multivariable power regression analysis is performed to
propose a new equation relating the median size with unit discharge,
bed slope, riprap thickness and coefficient of uniformity. The
proposed relationship satisfactorily predicts the median angular stone
size with ±20% error. Further, the required size of the rounded stone
is more than the angular stone for the same unit discharge and the
ratio increases with unit discharge and also with embankment slope
of the riprap.
Abstract: Discovery schools in Jordan are connected in one flat
ATM bridge network. All Schools connected to the network will hear
broadcast traffic. High percentage of unwanted traffic such as
broadcast, consumes the bandwidth between schools and QRC.
Routers in QRC have high CPU utilization. The number of
connections on the router is very high, and may exceed recommend
manufacturing specifications. One way to minimize number of
connections to the routers in QRC, and minimize broadcast traffic is
to use PPPoE. In this study, a PPPoE solution has been presented
which shows high performance for the clients when accessing the
school server resources. Despite the large number of the discovery
schools at MoE, the experimental results show that the PPPoE
solution is able to yield a satisfactory performance for each client at
the school and noticeably reduce the traffic broadcast to the QRC.
Abstract: Cylindrical concrete reservoirs are appropriate choice
for storing liquids as water, oil and etc. By using of the pre-cast
concrete reservoirs instead of the in-situ constructed reservoirs, the
speed and precision of the construction would considerably increase.
In this construction method, wall and roof panels would make in
factory with high quality materials and precise controlling. Then,
pre-cast wall and roof panels would carry out to the construction site
for assembling. This method has a few faults such as: the existing
weeks in connection of wall panels together and wall panels to
foundation. Therefore, these have to be resisted under applied loads
such as seismic load. One of the innovative methods which was
successfully applied for seismic retrofitting of numerous pre-cast
cylindrical water reservoirs in New Zealand, using of the high tensile
cables around the reservoirs and post-tensioning them. In this paper,
analytical modeling of wall and roof panels and post-tensioned
cables are carried out with finite element method and the effect of
height to diameter ratio, post-tensioning force value, liquid level in
reservoir, installing position of tendons on seismic response of
reservoirs are investigated.
Abstract: Although, it is a long time that human know about
the importance of environment in life, but at the last decade of 20
century, the space that was full of hot scientific, collegial and
political were made in environmental challenge, So much that, this
problem not only disarrange the peace and security of life, but also it
has threatened human existence. One of the problems in last years
that are significant for authorities is unsatisfactory achieved results
against of using huge cost for magnificent environmental projects.
This subject leads thinker to this thought that for solving the
environmental problems it is needed new methods include of
sociology, ethics and philosophic, etc. methods apart of technical
affairs. Environment ethics is a new branch of philosophic ethics
discussion that discusses about the ethics relationship between
humans and universe that is around them. By notifying to the above
considered affairs, in today world, necessity of environmental ethics
for environment management is reduplicated. In the following the
article has been focused on environmental ethics role and
environmental management methods and techniques for developing
it.
Abstract: Leave of absence is important in maintaining a good
status of human resource quality. Allowing the employees temporarily
free from the routine assignments can vitalize the workers- morality
and productivity. This is particularly critical to secure a satisfactory
service quality for healthcare professionals of which were typically
featured with labor intensive and complicated works to perform. As
one of the veteran hospitals that were found and operated by the
Veteran Department of Taiwan, the nursing staff of the case hospital
was squeezed to an extreme minimum level under the pressure of a
tight budgeting. Leave of absence on schedule became extremely
difficult, especially for the intensive care units (ICU), in which
required close monitoring over the cared patients, and that had more
easily driven the ICU nurses nervous. Even worse, the deferred leaves
were more than 10 days at any time in the ICU because of a fluctuating
occupancy. As a result, these had brought a bad setback to this
particular nursing team, and consequently defeated the job
performance and service quality. To solve this problem and
accordingly to strengthen their morality, a project team was organized
across different departments specific for this. Sufficient information
regarding jobs and positions requirements, labor resources, and actual
working hours in detail were collected and analyzed in the team
meetings. Several alternatives were finalized. These included job
rotating, job combination, leave on impromptu and cross-departmental
redeployment. Consequently, the deferred leave days sharply reduced
70% to a level of 3 or less days. This improvement had not only
provided good shelter for the ICU nurses that improved their job
performance and patient safety but also encouraged the nurses active
participating of a project and learned the skills of solving problems
with colleagues.
Abstract: This paper is focused on issues of process modeling
and two model based control strategies of a fed-batch sugar
crystallization process applying the concept of artificial neural
networks (ANNs). The control objective is to force the operation into
following optimal supersaturation trajectory. It is achieved by
manipulating the feed flow rate of sugar liquor/syrup, considered as
the control input. The control task is rather challenging due to the
strong nonlinearity of the process dynamics and variations in the
crystallization kinetics. Two control alternatives are considered –
model predictive control (MPC) and feedback linearizing control
(FLC). Adequate ANN process models are first built as part of the
controller structures. MPC algorithm outperforms the FLC approach
with respect to satisfactory reference tracking and smooth control
action. However, the MPC is computationally much more involved
since it requires an online numerical optimization, while for the FLC
an analytical control solution was determined.
Abstract: A Decision Support System/Expert System for stock
portfolio selection presented where at first step, both technical and
fundamental data used to estimate technical and fundamental return
and risk (1st phase); Then, the estimated values are aggregated with
the investor preferences (2nd phase) to produce convenient stock
portfolio.
In the 1st phase, there are two expert systems, each of which is
responsible for technical or fundamental estimation. In the technical
expert system, for each stock, twenty seven candidates are identified
and with using rough sets-based clustering method (RC) the effective
variables have been selected. Next, for each stock two fuzzy rulebases
are developed with fuzzy C-Mean method and Takai-Sugeno-
Kang (TSK) approach; one for return estimation and the other for
risk. Thereafter, the parameters of the rule-bases are tuned with backpropagation
method. In parallel, for fundamental expert systems,
fuzzy rule-bases have been identified in the form of “IF-THEN" rules
through brainstorming with the stock market experts and the input
data have been derived from financial statements; as a result two
fuzzy rule-bases have been generated for all the stocks, one for return
and the other for risk.
In the 2nd phase, user preferences represented by four criteria and
are obtained by questionnaire. Using an expert system, four estimated
values of return and risk have been aggregated with the respective
values of user preference. At last, a fuzzy rule base having four rules,
treats these values and produce a ranking score for each stock which
will lead to a satisfactory portfolio for the user.
The stocks of six manufacturing companies and the period of
2003-2006 selected for data gathering.