Abstract: The aim of this study was to evaluate the sensitivity
of a range of EEG indices to time-on-task effects and to a workload
manipulation (cueing), during performance of a resource-limited
vigilance task. Effects of task period and cueing on performance and
subjective state response were consistent with previous vigilance
studies and with resource theory. Two EEG indices – the Task Load
Index (TLI) and global lower frequency (LF) alpha power – showed
effects of task period and cueing similar to those seen with correct
detections. Across four successive task periods, the TLI declined and
LF alpha power increased. Cueing increased TLI and decreased LF
alpha. Other indices – the Engagement Index (EI), frontal theta and
upper frequency (UF) alpha failed to show these effects. However, EI
and frontal theta were sensitive to interactive effects of task period
and cueing, which may correspond to a stronger anxiety response to
the uncued task.
Abstract: FW4 is a newly developed hot die material widely
used in Forging Dies manufacturing. The right selection of the
machining conditions is one of the most important aspects to take
into consideration in the Electrical Discharge Machining (EDM) of
FW4. In this paper an attempt has been made to develop
mathematical models for relating the Material Removal Rate (MRR),
Tool Wear Ratio (TWR) and surface roughness (Ra) to machining
parameters (current, pulse-on time and voltage). Furthermore, a study
was carried out to analyze the effects of machining parameters in
respect of listed technological characteristics. The results of analysis
of variance (ANOVA) indicate that the proposed mathematical
models, can adequately describe the performance within the limits of
the factors being studied.
Abstract: Simultaneous Saccharification and Fermentation (SSF) of sugarcane bagasse by cellulase and Pachysolen tannophilus MTCC *1077 were investigated in the present study. Important process variables for ethanol production form pretreated bagasse were optimized using Response Surface Methodology (RSM) based on central composite design (CCD) experiments. A 23 five level CCD experiments with central and axial points was used to develop a statistical model for the optimization of process variables such as incubation temperature (25–45°) X1, pH (5.0–7.0) X2 and fermentation time (24–120 h) X3. Data obtained from RSM on ethanol production were subjected to the analysis of variance (ANOVA) and analyzed using a second order polynomial equation and contour plots were used to study the interactions among three relevant variables of the fermentation process. The fermentation experiments were carried out using an online monitored modular fermenter 2L capacity. The processing parameters setup for reaching a maximum response for ethanol production was obtained when applying the optimum values for temperature (32°C), pH (5.6) and fermentation time (110 h). Maximum ethanol concentration (3.36 g/l) was obtained from 50 g/l pretreated sugarcane bagasse at the optimized process conditions in aerobic batch fermentation. Kinetic models such as Monod, Modified Logistic model, Modified Logistic incorporated Leudeking – Piret model and Modified Logistic incorporated Modified Leudeking – Piret model have been evaluated and the constants were predicted.
Abstract: The aim of this study is to examine the reading
comprehension scores of Turkish 5th grade students according to the
variables given in the student questionnaire. In this descriptive
survey study research participated 279 5th grade students, who
studied at 10 different primary schools in four provinces of Ankara in
2008-2009 academic year. Two different data collection tools were
made use of in the study: “Reading Comprehension Test" and
“Student Information Questionnaire". Independent sample t-test, oneway
Anova and two-way Anova tests were used in the analyses of
the gathered data. The results of the study indicate that the reading
comprehension scores of the students differ significantly according to
sex of the students, the number of books in their houses, the
frequency of summarizing activities on the reading text of free and
the frequency reading hours provided by their teachers; but, differ
not significantly according to educational level of their mothers and
fathers.
Abstract: We present a low frequency watermarking method
adaptive to image content. The image content is analyzed and
properties of HVS are exploited to generate a visual mask of the
same size as the approximation image. Using this mask we embed the
watermark in the approximation image without degrading the image
quality. Watermark detection is performed without using the original
image. Experimental results show that the proposed watermarking
method is robust against most common image processing operations,
which can be easily implemented and usually do not degrade the
image quality.
Abstract: Article devoted to the development of technologies
for medicine and agroecology by using plant organelle – spherosome.
Technological method of purification and isolation of this organelle
by using novel nanostructured carbon sorbent – “nanocarbosorb"
ARK type are presented. Also the methods of preparation of
nanocontainers based on using of spherosome with loaded isosorbide
dinitrate, piroxicam or diclofenak are exhibited. We found that the
spherosome could be applied for ecological aims as bioregulator and
also as biosensor for determination of ammonia ions in water
reservoirs at concentration range 1mM to 100mM.
Abstract: Evolvable Hardware (EHW) has been regarded as adaptive system acquired by wide application market. Consumer market of any good requires diversity to satisfy consumers- preferences. Adaptation of EHW is a key technology that could provide individual approach to every particular user. This situation raises a question: how to set target for evolutionary algorithm? The existing techniques do not allow consumer to influence evolutionary process. Only designer at the moment is capable to influence the evolution. The proposed consumer-triggered evolution overcomes this problem by introducing new features to EHW that help adaptive system to obtain targets during consumer stage. Classification of EHW is given according to responsiveness, imitation of human behavior and target circuit response. Home intelligent water heating system is considered as an example.
Abstract: This paper discusses the cued speech recognition
methods in videoconference. Cued speech is a specific gesture
language that is used for communication between deaf people. We
define the criteria for sentence intelligibility according to answers of
testing subjects (deaf people). In our tests we use 30 sample videos
coded by H.264 codec with various bit-rates and various speed of
cued speech. Additionally, we define the criteria for consonant sign
recognizability in single-handed finger alphabet (dactyl) analogically
to acoustics. We use another 12 sample videos coded by H.264 codec
with various bit-rates in four different video formats. To interpret the
results we apply the standard scale for subjective video quality
evaluation and the percentual evaluation of intelligibility as in
acoustics. From the results we construct the minimum coded bit-rate
recommendations for every spatial resolution.
Abstract: The purposes of this research are: 1) to study the media
literacy of early teenagers, and 2) to study the interaction between
gender and timing of media exposure that affects the media literacy
of teenagers. The sample of the study included 400 young people
aged between 11 to 17 and who were living in Bangkok. The data
was collected using questionnaires. Two-way ANOVA was used in
analyzing the collected data. The result revealed that gender and
timing of media exposure affected the media literacy of early
teenagers with statistical significance at the level of 0.05.
Abstract: Study was conducted to determine the concentration of
copper, cadmium, lead and zinc in Cabomba furcata that found
abundance in Lake Chini. This aquatic plant was collected randomly
within the lake for heavy metal determination. Water quality
measurement was undertaken in situ for temperature, pH,
conductivity and dissolved oksigen using portable multi sensor probe
YSI model 556. The C. furcata was digested using wet digestion
method and heavy metal concentrations were analysed using Atomic
Absorption Spectrometer (AAS) Perkin Elmer 4100B (flame
method). Result of water quality classify Lake Chini between class II
to class III using Malaysian Water Quality Standard. According to
this standard, Lake Chini has moderate quality, which normal for
natural lake. Heavy metal concentrations in C.furcata were low and
found to be lower than the critical toxic value in aquatic plants. Oneway
ANOVA test indicated the heavy metal concentrations in
C.furcata were significantly differ between sampling location. Water
quality and heavy metal concentrations indicates that Lake Chini was
not receives anthropogenic load from nearby activities.
Abstract: The aim of this study is evaluating the antinociceptive
and anti-inflamatory activity of Geum kokanicum. After
determination total extract LD50, different doses of extract were
chosen for intrapritoneal injections. In inflammation test, male NMRI
mice were divided into 6 groups: control (normal saline), positive
control (Dexamethasone 15mg/kg), and total extract (0.025, 0.05,
0.1, and 0.2 gr/kg). The inflammation was produced by xyleneinduced
edema. In order to evaluate the antinociceptive effect of total
extract, formalin test was used. Mice were divided into 6 groups:
control, positive control (morphine 10mg/kg), and 4 groups which
received total extract. Then they received Formalin. The animals
were observed for the reaction to pain. Data were analyzed using
One-way ANOVA followed by Tukey-Kramer multiple comparison
test. LD50 was 1 gr/kg. Data indicated that 0.5,0.1 and 0.2 gr/kg
doses of total extract have particular antinociceptive and antiinflammatory
effects in a comparison with control (P
Abstract: This questionnaire-based study, aimed to measure and
compare the awareness of English reading strategies among EFL
learners at Bangkok University (BU) classified by their gender, field
of study, and English learning experience. Proportional stratified
random sampling was employed to formulate a sample of 380 BU
students. The data were statistically analyzed in terms of the mean
and standard deviation. t-Test analysis was used to find differences in
awareness of reading strategies between two groups (-male and
female- /-science and social-science students). In addition, one-way
analysis of variance (ANOVA) was used to compare reading strategy
awareness among BU students with different lengths of English
learning experience. The results of this study indicated that the
overall awareness of reading strategies of EFL learners at BU was at
a high level (ðÑ = 3.60) and that there was no statistically significant
difference between males and females, and among students who have
different lengths of English learning experience at the significance
level of 0.05. However, significant differences among students
coming from different fields of study were found at the same level of
significance.
Abstract: In present study the effects of anti-inflammatory and
antinociceptive of vitex hydro-alcoholic extract were evaluated on
male mice. In inflammatory test mice were divided into 7 groups:
first group was control. The second group, positive control group,
received dexamethasone (15 mg/kg) and the other five groups
received different doses of hydroalcohol extract of Vitex fruit (265,
365, 465, 565, and 665 mg/kg). The inflammation was caused by
xylene-induced ear edema. Formalin test was used for evaluation of
antinociceptive effect of extract. In this test, mice were divided into 7
groups: control, morphine (10mg/kg) as positive control group, and
Vitex extract groups ((265, 365, 465, 565, and 665 mg/kg). All drugs
were administered intrapritoneally, 30 min before each test. The data
were analyzed using one-way ANOVA followed by Tukey-kramer
multiple comparison test. Results have shown significant antiinflammatory
effects of extract at all dosed as compared with control
(P
Abstract: The traditional Failure Mode and Effects Analysis
(FMEA) uses Risk Priority Number (RPN) to evaluate the risk level
of a component or process. The RPN index is determined by
calculating the product of severity, occurrence and detection indexes.
The most critically debated disadvantage of this approach is that
various sets of these three indexes may produce an identical value of
RPN. This research paper seeks to address the drawbacks in
traditional FMEA and to propose a new approach to overcome these
shortcomings. The Risk Priority Code (RPC) is used to prioritize
failure modes, when two or more failure modes have the same RPN.
A new method is proposed to prioritize failure modes, when there is a
disagreement in ranking scale for severity, occurrence and detection.
An Analysis of Variance (ANOVA) is used to compare means of
RPN values. SPSS (Statistical Package for the Social Sciences)
statistical analysis package is used to analyze the data. The results
presented are based on two case studies. It is found that the proposed
new methodology/approach resolves the limitations of traditional
FMEA approach.
Abstract: This paper deals optimized model to investigate the
effects of peak current, pulse on time and pulse off time in EDM performance on material removal rate of titanium alloy utilizing copper tungsten as electrode and positive polarity of the electrode. The experiments are carried out on Ti6Al4V. Experiments were
conducted by varying the peak current, pulse on time and pulse off time. A mathematical model is developed to correlate the influences of these variables and material removal rate of workpiece. Design of
experiments (DOE) method and response surface methodology
(RSM) techniques are implemented. The validity test of the fit and adequacy of the proposed models has been carried out through
analysis of variance (ANOVA). The obtained results evidence that as
the material removal rate increases as peak current and pulse on time
increases. The effect of pulse off time on MRR changes with peak ampere. The optimum machining conditions in favor of material removal rate are verified and compared. The optimum machining
conditions in favor of material removal rate are estimated and verified with proposed optimized results. It is observed that the developed model is within the limits of the agreeable error (about
4%) when compared to experimental results. This result leads to desirable material removal rate and economical industrial machining to optimize the input parameters.
Abstract: Distance education program is a dimension of contemporary and new education technologies. Concepts and applications in this field are the results of a series of educational demands and developments in various communication and education technologies. Distance education applications have some conceptual bases. These are creating new education opportunities, realizing work-education unity, getting democratic in education, lifelong education, tendency to individual matters, effective use of institutions, integration of technology and education, tendency to individual and social needs, taking three dimensional integration as the main principle (publishing, printed materials and face to face education), reaching maximum mass, individual and mass education integrity and education demand and financial matters balance. Economics, Business Administration and Open Education faculties, which have been giving education within Anadolu University since 1982 in Turkey, are carrying on education with nearly 1.000.000 students. The aim of this study is to determine organizational commitment levels of students who have been studying at Anadolu University Economics, Business Administration and Open Education faculties in the scope of affective, continuance and nominative commitment in Allen&Meyer model. In the study, organizational commitment of the Economics, Business Administration and Open Education faculty students, who are receiving education by means of distance education, to their faculties is dealt after introducing Anadolu University Distance Education system which gives higher education via distance education method in Turkey. In order to increase the success level of faculties it is required for students to have high level of organizational commitment to their faculties. A questionnaire has been applied by using “Organizational Commitment Scale", developed by Meyer&Allen to determine organizational commitments of Economics, Business Administration and Open Education students. Organizational commitment is dealt with as affective, continuance and nominative commitment. The questionnaire was applied face to face to randomly chosen 500 students living in Eskişehir and the data was downloaded to the computer by using SPSS program and the results were analyzed in terms of demographic features (gender, age, marital status, years of study, work and income level) of students by using frequency test, ttest and ANOVA test. As a result of these analyses, when the comments of Open Education Faculty students on levels of affective, continuance and nominative commitment to their faculties were examined, it has been revealed that continuance commitment level has the highest rate. Among the female participants; continuance commitment is high in the age range of 30-40, for normative commitment it is 17-22. However no dominant age range was defined for affective commitment. Regarding the marital status; continuance commitment average is higher among married participants; but nominative affective commitment average is higher among single participants. As to the years of study, affective and continuance commitment is higher among senior students while normative commitment is higher among junior students. Moreover; in terms of continuance, affective and normative commitment, those who do not work and have low income have higher level of all there commitment types than those who work and have relatively high income.
Abstract: The aim of this research is to evaluate surface
roughness and develop a multiple regression model for surface roughness as a function of cutting parameters during the turning of
flame hardened medium carbon steel with TiN-Al2O3-TiCN coated inserts. An experimental plan of work and signal-to-noise ratio (S/N)
were used to relate the influence of turning parameters to the
workpiece surface finish utilizing Taguchi methodology. The effects
of turning parameters were studied by using the analysis of variance (ANOVA) method. Evaluated parameters were feed, cutting speed,
and depth of cut. It was found that the most significant interaction among the considered turning parameters was between depth of cut and feed. The average surface roughness (Ra) resulted by TiN-Al2O3-
TiCN coated inserts was about 2.44 μm and minimum value was 0.74 μm. In addition, the regression model was able to predict values for surface roughness in comparison with experimental values within
reasonable limit.
Abstract: Abrasive Jet Machining is an Unconventional
machining process in which the metal is removed from brittle and
hard material in the form of micro-chips. With increase in need of
materials like ceramics, composites, in manufacturing of various
Mechanical & Electronic components, AJM has become a useful
technique for micro machining. The present study highlights the
influence of different parameters like Pressure, SOD, Time, Abrasive
grain size, nozzle diameter on the Metal removal of FRP (Fiber
Reinforced Polymer) composite by Abrasive jet machining. The
results of the Experiments conducted were analyzed and optimized
with TAGUCHI method of Optimization and ANOVA for Optimal
Value.
Abstract: This paper presents a web based remote access
microcontroller laboratory. Because of accelerated development in
electronics and computer technologies, microcontroller-based devices
and appliances are found in all aspects of our daily life. Before the
implementation of remote access microcontroller laboratory an
experiment set is developed by teaching staff for training
microcontrollers. Requirement of technical teaching and industrial
applications are considered when experiment set is designed.
Students can make the experiments by connecting to the experiment
set which is connected to the computer that set as the web server. The
students can program the microcontroller, can control digital and
analog inputs and can observe experiment. Laboratory experiment
web page can be accessed via www.elab.aku.edu.tr address.
Abstract: In this paper we present a combined
hashing/watermarking method for image authentication. A robust
image hash, invariant to legitimate modifications, but fragile to
illegitimate modifications is generated from the local image
characteristics. To increase security of the system the watermark is
generated using the image hash as a key. Quantized Index
Modulation of DCT coefficients is used for watermark embedding.
Watermark detection is performed without use of the original image.
Experimental results demonstrate the effectiveness of the presented
method in terms of robustness and fragility.