Abstract: This research investigates the design of a low-cost 3D
spatial interaction approach using the Wii Remote for immersive
Head-Mounted Display (HMD) virtual reality. Current virtual reality
applications that incorporate the Wii Remote are either desktop
virtual reality applications or systems that use large screen displays.
However, the requirements for an HMD virtual reality system differ
from such systems. This is mainly because in HMD virtual reality,
the display screen does not remain at a fixed location. The user views
the virtual environment through display screens that are in front of
the user-s eyes and when the user moves his/her head, these screens
move as well. This means that the display has to be updated in realtime
based on where the user is currently looking. Normal usage of
the Wii Remote requires the controller to be pointed in a certain
direction, typically towards the display. This is too restrictive for
HMD virtual reality systems that ideally require the user to be able to
turn around in the virtual environment. Previous work proposed a
design to achieve this, however it suffered from a number of
drawbacks. The aim of this study is to look into a suitable method of
using the Wii Remote for 3D interaction in a space around the user
for HMD virtual reality. This paper presents an overview of issues
that had to be considered, the system design as well as experimental
results.
Abstract: High strength concrete has been used in situations
where it may be exposed to elevated temperatures. Numerous authors
have shown the significant contribution of polypropylene fiber to the
spalling resistance of high strength concrete.
When cement-based composite that reinforced by polypropylene
fibers heated up to 170 °C, polypropylene fibers readily melt and
volatilize, creating additional porosity and small channels in to the
matrix that cause the poor structure and low strength.
This investigation develops on the mechanical properties of mortar
incorporating polypropylene fibers exposed to high temperature.
Also effects of different pozzolans on strength behaviour of samples
at elevated temperature have been studied.
To reach this purpose, the specimens were produced by partial
replacement of cement with finely ground glass, silica fume and rice
husk ash as high reactive pozzolans. The amount of this replacement
was 10% by weight of cement to find the effects of pozzolans as a
partial replacement of cement on the mechanical properties of
mortars. In this way, lots of mixtures with 0%, 0.5%, 1% and 1.5% of
polypropylene fibers were cast and tested for compressive and
flexural strength, accordance to ASTM standard. After that
specimens being heated to temperatures of 300, 600 °C, respectively,
the mechanical properties of heated samples were tested.
Mechanical tests showed significant reduction in compressive
strength which could be due to polypropylene fiber melting. Also
pozzolans improve the mechanical properties of sampels.
Abstract: Calcium is a vital second messenger used in signal transduction. Calcium controls secretion, cell movement, muscular contraction, cell differentiation, ciliary beating and so on. Two theories have been used to simplify the system of reaction-diffusion equations of calcium into a single equation. One is excess buffer approximation (EBA) which assumes that mobile buffer is present in excess and cannot be saturated. The other is rapid buffer approximation (RBA), which assumes that calcium binding to buffer is rapid compared to calcium diffusion rate. In the present work, attempt has been made to develop a model for calcium diffusion under excess buffer approximation in neuron cells. This model incorporates the effect of [Na+] influx on [Ca2+] diffusion,variable calcium and sodium sources, sodium-calcium exchange protein, Sarcolemmal Calcium ATPase pump, sodium and calcium channels. The proposed mathematical model leads to a system of partial differential equations which have been solved numerically using Forward Time Centered Space (FTCS) approach. The numerical results have been used to study the relationships among different types of parameters such as buffer concentration, association rate, calcium permeability.
Abstract: Use of fly ash as a supplementary cementing material
in large volumes can bring both technological and economic benefits
for concrete industry. In this investigation mix proportions for high
volume fly ash concrete were determined at cement replacement
levels of 50%, 55%, 60% and 65% with low calcium fly ash. Flexural
and compressive strengths of different mixes were measured at ages
of 7, 28 and 90 days. Flexural strength of composite section prepared
from pavement quality and lean high volume fly ash concrete was
determined at the age of 28 days. High volume fly ash concrete mixes
exhibited higher rate of strength gain and age factors than
corresponding reference concrete mixes. The optimum cement
replacement level for pavement quality concrete was found to be
60%. The consideration of bond between pavement quality and lean
of high volume fly ash concrete will be beneficial in design of rigid
pavements.
Abstract: Ultrastructure of duodenum mucosa of irradiated rat
was studied versus dose rate of irradiation following exposure to
gamma rays from 60-Cobalt source. The animals were whole body
irradiated at two dose rates (1 Gy.mn-1 and 1 Gy.h-1) and three total
doses (1, 2 or 4 Gy) for each dose rate. 24 or 48 h after irradiation,
their small intestine was removed and samples of duodenum were
processed for observations under a transmission electron microscopy.
Samples of duodenum mucosa of control rats were processed in the
same way. For the lower dose rate of 1 Gy.h-1, main lesions
characteristic of apoptosis were detected within irradiated enterocytes
at a total dose of 2 Gy and 24 h after exposure. Necrosis was noted in
the samples, 48 h after exposition. For the higher dose rate of 1
Gy.mn-1, fewer changes were detected at all total doses 24 or 48 h
irradiation. Thus, it was shown that the appearance of radiationinduced
alterations varies not only with increasing total dose and
post-irradiation time but especially with decreasing dose rate.
Abstract: Rooted in the study of social functioning of space in architecture, Space Syntax (SS) and the more recent Network Pattern (NP) researches demonstrate the 'spatial structures' of city, i.e. the hierarchical patterns of streets, junctions and alley ends. Applying SS and NP models, planners can conceptualize the real city-s patterns. Although, both models yield the optimal path of the city their underpinning displays of the city-s spatial configuration differ. The Axial Map analyzes the topological non-distance-based connectivity structure, whereas, the Central-Node Map and the Shortcut-Path Map, in contrast, analyze the metrical distance-based structures. This research contrasts and combines them to understand various forms of city-s structures. It concludes that, while they reveal different spatial structures, Space Syntax and Network Pattern urban models support each the other. Combining together they simulate the global access and the locally compact structures namely the central nodes and the shortcuts for the city.
Abstract: After reporting a literature review on Customer
Relationship Management (CRM) and knowledge management, some
important issued arise, in particular related to the lack of success of
CRM strategies implementation. The paper contributes to this
proposing an integrated model of CRM success taking into account
complementary factors such as organizational factors, technology,
knowledge management and customer orientation.
Abstract: Early detection of dementia by testing the spatial
memory can be applied using a virtual environment. This paper
presents guidelines on how to design a virtual environment
specifically for elderly in early detection of dementia. The specific
design needs to be considered because the effectiveness of the
technology relies on the ability of the end user to use it. The primary
goal of these guidelines is to promote accessibility. Based on these
guidelines, a virtual simulation was developed and evaluated. The
results on usability of acceptance and satisfaction that are tested on
young (control group) and elderly participants indicate that these
guidelines are reliable and useful for use with elderly people.
Abstract: A behavioral model of a second order switchedcapacitor Sigma-Delta modulator is presented. The purpose of this work is the presentation of a behavioral model of a second order switched capacitor ΣΔ modulator considering (Error due to Clock Jitter, Thermal noise Amplifier Noise, Amplifier Slew-Rate, Non linearity of amplifiers, Gain error, Charge Injection, Clock Feedthrough, and Nonlinear on-resistance). A comparison between the use of MOS switches and the use transmission gate switches use is analyzed.
Abstract: The introduction of haptic elements in a graphic user interfaces are becoming more widespread. Since haptics are being introduced rapidly into computational tools, investigating how these models affect Human-Computer Interaction would help define how to integrate and model new modes of interaction. The interest of this paper is to discuss and investigate the issues surrounding Haptic and Graphic User Interface designs (GUI) as separate systems, as well as understand how these work in tandem. The development of these systems is explored from a psychological perspective, based on how usability is addressed through learning and affordances, defined by J.J. Gibson. Haptic design can be a powerful tool, aiding in intuitive learning. The problems discussed within the text is how can haptic interfaces be integrated within a GUI without the sense of frivolity. Juxtaposing haptics and Graphic user interfaces has issues of motivation; GUI tends to have a performatory process, while Haptic Interfaces use affordances to learn tool use. In a deeper view, it is noted that two modes of perception, foveal and ambient, dictate perception. These two modes were once thought to work in tandem, however it has been discovered that these processes work independently from each other. Foveal modes interpret orientation is space which provide for posture, locomotion, and motor skills with variations of the sensory information, which instructs perceptions of object-task performance. It is contended, here, that object-task performance is a key element in the use of Haptic Interfaces because exploratory learning uses affordances in order to use an object, without meditating an experience cognitively. It is a direct experience that, through iteration, can lead to skill-sets. It is also indicated that object-task performance will not work as efficiently without the use of exploratory or kinesthetic learning practices. Therefore, object-task performance is not as congruently explored in GUI than it is practiced in Haptic interfaces.
Abstract: We present a label-free biosensor based on
electrochemical impedance spectroscopy for the detection of proinflammatory
cytokine Tumor Necrosis Factor (TNF-α). Secretion of
TNF-α has been correlated to the onset of various diseases including
rheumatoid arthritis, Crohn-s disease etc. Gold electrodes were
patterned on a silicon substrate and self assembled monolayer of
dithiobis-succinimidyl propionate was used to develop the biosensor
which achieved a detection limit of ~57fM. A linear relationship was
also observed between increasing TNF-α concentrations and chargetransfer
resistance within a dynamic range of 1pg/ml – 1ng/ml.
Abstract: This paper describes a new approach of classification
using genetic programming. The proposed technique consists of
genetically coevolving a population of non-linear transformations on
the input data to be classified, and map them to a new space with a
reduced dimension, in order to get a maximum inter-classes
discrimination. The classification of new samples is then performed
on the transformed data, and so become much easier. Contrary to the
existing GP-classification techniques, the proposed one use a
dynamic repartition of the transformed data in separated intervals, the
efficacy of a given intervals repartition is handled by the fitness
criterion, with a maximum classes discrimination. Experiments were
first performed using the Fisher-s Iris dataset, and then, the KDD-99
Cup dataset was used to study the intrusion detection and
classification problem. Obtained results demonstrate that the
proposed genetic approach outperform the existing GP-classification
methods [1],[2] and [3], and give a very accepted results compared to
other existing techniques proposed in [4],[5],[6],[7] and [8].
Abstract: This study analyzes the effect of discretization on
classification of datasets including continuous valued features. Six
datasets from UCI which containing continuous valued features are
discretized with entropy-based discretization method. The
performance improvement between the dataset with original features
and the dataset with discretized features is compared with k-nearest
neighbors, Naive Bayes, C4.5 and CN2 data mining classification
algorithms. As the result the classification accuracies of the six
datasets are improved averagely by 1.71% to 12.31%.
Abstract: Microbubbbles incorporating ultrasound have been used to increase the efficacy of targeted drug delivery, because microstreaming induced by cavitating bubbles affects the drug perfusion into the target cells and tissues. In order to clarify the physical effects of microstreaming on drug perfusion into tissues, a preliminary experimental study of perfusion enhancement by a stably oscillating microbubble was performed. Microstreaming was induced by an oscillating bubble at 15 kHz, and perfusion of dye into an agar phantom was optically measured by histology on agar phantom. Surface color intensity and the penetration length of dye in the agar phantom were increased more than 70% and 30%, respectively, due to the microstreaming induced by an oscillating bubble. The mass of dye perfused into a tissue phantom for 30 s was increased about 80% in the phantom with an oscillating bubble. This preliminary experiment shows the physical effects of steady streaming by an oscillating bubble can enhance the drug perfusion into the tissues while minimizing the biological effects.
Abstract: This paper focuses on the use of project work as a
pretext for applying the conventions of writing, or the correctness of
mechanics, usage, and sentence formation, in a content-based class in
a Rajabhat University. Its aim was to explore to what extent the
student teachers’ academic achievement of the basic writing features
against the 70% attainment target after the use of project is. The
organization of work around an agreed theme in which the students
reproduce language provided by texts and instructors is expected to
enhance students’ correct writing conventions. The sample of the
study comprised of 38 fourth-year English major students. The data
was collected by means of achievement test and student writing
works. The scores in the summative achievement test were analyzed
by mean score, standard deviation, and percentage. It was found that
the student teachers do more achieve of practicing mechanics and
usage, and less in sentence formation. The students benefited from
the exposure to texts during conducting the project; however, their
automaticity of how and when to form phrases and clauses into
simple/complex sentences had room for improvement.
Abstract: Despite the relatively large number of studies that
have examined the use of appeals in advertisements, research on the
use of appeals in green advertisements is still underdeveloped and
needs to be investigated further, as it is definitely a tool for marketers
to create illustrious ads. In this study, content analysis was employed
to examine the nature of green advertising appeals and to match the
appeals with the green advertisements. Two different types of green
print advertisings, product orientation and organizational image
orientation were used. Thirty highly educated participants with
different backgrounds were asked individually to ascertain three
appeals out of thirty-four given appeals found among forty real green
advertisements. To analyze participant responses and to group them
based on common appeals, two-step K-mean clustering is used. The
clustering solution indicates that eye-catching graphics and
imaginative appeals are highly notable in both types of green ads.
Depressed, meaningful and sad appeals are found to be highly used in
organizational image orientation ads, whereas, corporate image,
informative and natural appeals are found to be essential for product
orientation ads.
Abstract: On-line handwritten scripts are usually dealt with pen tip traces from pen-down to pen-up positions. Time evaluation of the pen coordinates is also considered along with trajectory information. However, the data obtained needs a lot of preprocessing including filtering, smoothing, slant removing and size normalization before recognition process. Instead of doing such lengthy preprocessing, this paper presents a simple approach to extract the useful character information. This work evaluates the use of the counter- propagation neural network (CPN) and presents feature extraction mechanism in full detail to work with on-line handwriting recognition. The obtained recognition rates were 60% to 94% using the CPN for different sets of character samples. This paper also describes a performance study in which a recognition mechanism with multiple thresholds is evaluated for counter-propagation architecture. The results indicate that the application of multiple thresholds has significant effect on recognition mechanism. The method is applicable for off-line character recognition as well. The technique is tested for upper-case English alphabets for a number of different styles from different peoples.
Abstract: The modified Claus process is commonly used in oil
refining and gas processing to recover sulfur and destroy
contaminants formed in upstream processing. A Claus furnace feed
containing a relatively low concentration of H2S may be incapable of
producing a stable flame. Also, incomplete combustion of
hydrocarbons in the feed can lead to deterioration of the catalyst in
the reactors due to soot or carbon deposition. Therefore, special
consideration is necessary to achieve the appropriate overall sulfur
recovery. In this paper, some configurations available to treat lean
acid gas streams are described and the most appropriate ones are
studied to overcome low H2S concentration problems. As a result,
overall sulfur recovery is investigated for feed preheating and hot gas
configurations.
Abstract: Application of pesticides in the paddy fields has
deleterious effects on non-target organisms including cyanobacteria
which are photosynthesizing and nitrogen fixing micro-organisms
contributing significantly towards soil fertility and crop yield.
Pesticide contamination in the paddy fields has manifested into a
serious global environmental concern. To study the effect of one such
pesticide, three cyanobacterial strains; Anabaena fertilissima,
Aulosira fertilissima and Westiellopsis prolifica were selected for
their stress responses to an Organochlorine insecticide - 6, 7, 8, 9, 10,
10-hexachloro-1, 5, 5a, 6, 9, 9a-hexahydro-6, 9-methano-2, 4, 3-
benzodioxathiepine-3-oxide, with reference to their photosynthesic
pigments-chlorophyll-a and carotenoids as well as accessory
pigments-phycobiliproteins (phycocyanin, allophycocyanin and
phycoerythrin), stress induced biochemical metabolites like
carbohydrates, proteins, amino acids, phenols and enzymes-nitrate
reductase, glutamine synthetase and succinate dehydrogenase. All
the three cyanobacterial strains were adversely affected by the
insecticide doses and inhibition was dose dependent. Reduction in
photosynthetic and accessory pigments, metabolites, nitrogen fixing
and respiratory enzymes of the test organisms were accompanied
with an initial increase in their total protein at lower Organochlorine
doses. On the other hand, increased amount of phenols in all the
insecticide treated concentrations was indicative of stressed activities
of the organisms.
Abstract: High performance Resistive Random Access Memory
(RRAM) based on HfOx has been prepared and its temperature
instability has been investigated in this work. With increasing
temperature, it is found that: leakage current at high resistance state
increases, which can be explained by the higher density of traps
inside dielectrics (related to trap-assistant tunneling), leading to a
smaller On/Off ratio; set and reset voltages decrease, which may be
attributed to the higher oxygen ion mobility, in addition to the
reduced potential barrier to create / recover oxygen ions (or oxygen
vacancies); temperature impact on the RRAM retention degradation
is more serious than electrical bias.