Abstract: This paper provides a flexible way of controlling
Variable-Bit-Rate (VBR) of compressed digital video, applicable to
the new H264 video compression standard. The entire video
sequence is assessed in advance and the quantisation level is then set
such that bit rate (and thus the frame rate) remains within
predetermined limits compatible with the bandwidth of the
transmission system and the capabilities of the remote end, while at
the same time providing constant quality similar to VBR encoding.
A process for avoiding buffer starvation by selectively eliminating
frames from the encoded output at times when the frame rate is slow
(large number of bits per frame) will be also described. Finally, the
problem of buffer overflow will be solved by selectively eliminating
frames from the received input to the decoder. The decoder detects
the omission of the frames and resynchronizes the transmission by
monitoring time stamps and repeating frames if necessary.
Abstract: According to development of communications and
web-based technologies in recent years, e-Learning has became very
important for everyone and is seen as one of most dynamic teaching
methods.
Grid computing is a pattern for increasing of computing power
and storage capacity of a system and is based on hardware and
software resources in a network with common purpose. In this article
we study grid architecture and describe its different layers. In this
way, we will analyze grid layered architecture. Then we will
introduce a new suitable architecture for e-Learning which is based
on grid network, and for this reason we call it Grid Learning
Architecture. Various sections and layers of suggested architecture
will be analyzed; especially grid middleware layer that has key role.
This layer is heart of grid learning architecture and, in fact,
regardless of this layer, e-Learning based on grid architecture will
not be feasible.
Abstract: Antioxidant activities of ethanolic extracts of Ardisia
japonica Blume., Ageartum conyzoides Linn., and Cocculus hirsutus
Linn Diels. leaves was determined qualitatively and quantitatively in
this research. 1, 1-diphenyl-2-picrylhydrazyl (DPPH) free radical
solution was used to investigate free radical scavenging activity of
these leaves extracts. Ascorbic acid (Vitamin C) was used as the
standard. In the present investigation, it is found that all of these
extracts have remarkable antioxidant activities. The EC50 values of
these ethanolic extracts were 12.72 μg/ml for A. japonica, 15.19
μg/ml for A. conyzoides, 10.68 μg/ml for C. hirsutus respectively.
Among these Myanmar medicinal plants, C. hirsutus showed higher
antioxidant activities as well as free radical scavenging activity than
black tea (Camellia sinensis), the famous antioxidant, and A.
japonica and A. conyzoides showed a rather lower antioxidant
activity than tea extracts. According to results from bioassay with
carrot discs infected with Agrobacterium tumefaciens, all extracts
showed anti-tumor activity after 3 weeks of incubation. No gall was
detected in carrot disks treated with C. hirsutus and A. japonica
extracts in the dose of 100ppm and in carrot discs treated with A.
conyzoides extract in the dose of 1000 ppm. Therefore, the research
clearly indicates that these weedy plants of dry farm land are
exceptionally advantageous for human health.
Abstract: Partitions can play a significant role in minimising cochannel
interference of Wireless LANs by attenuating signals across
room boundaries. This could pave the way towards higher density
deployments in home and office environments through spatial
channel reuse. Yet, due to protocol limitations, the latest incantation
of IEEE 802.11 standard is still unable to take advantage of this fact:
Despite having clearly adequate Signal to Interference Ratio (SIR)
over co-channel neighbouring networks in other rooms, its goodput
falls significantly lower than its maximum in the absence of cochannel
interferers. In this paper, we describe how this situation can
be remedied via modest modifications to the standard.
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 condition of lightning surge causes the traveling waves and the temporary increase in voltage in the transmission line system. Lightning is the most harmful for destroying the transmission line and setting devices so it is necessary to study and analyze the temporary increase in voltage for designing and setting the surge arrester. This analysis describes the figure of the lightning wave in transmission line with 115 kV voltage level in Thailand by using ATP/EMTP program to create the model of the transmission line and lightning surge. Because of the limit of this program, it must be calculated for the geometry of the transmission line and surge parameter and calculation in the manual book for the closest value of the parameter. On the other hand, for the effects on surge protector when the lightning comes, the surge arrester model must be right and standardized as metropolitan electrical authority's standard. The candidate compared the real information to the result from calculation, also. The results of the analysis show that the temporary increase in voltage value will be rise to 326.59 kV at the line which is done by lightning when the surge arrester is not set in the system. On the other hand, the temporary increase in voltage value will be 182.83 kV at the line which is done by lightning when the surge arrester is set in the system and the period of the traveling wave is reduced, also. The distance for setting the surge arrester must be as near to the transformer as possible. Moreover, it is necessary to know the right distance for setting the surge arrester and the size of the surge arrester for preventing the temporary increase in voltage, effectively.
Abstract: SDMA (Space-Division Multiple Access) is a MIMO
(Multiple-Input and Multiple-Output) based wireless communication
network architecture which has the potential to significantly increase
the spectral efficiency and the system performance. The maximum
likelihood (ML) detection provides the optimal performance, but its
complexity increases exponentially with the constellation size of
modulation and number of users. The QR decomposition (QRD)
MUD can be a substitute to ML detection due its low complexity and
near optimal performance. The minimum mean-squared-error
(MMSE) multiuser detection (MUD) minimises the mean square
error (MSE), which may not give guarantee that the BER of the
system is also minimum. But the minimum bit error rate (MBER)
MUD performs better than the classic MMSE MUD in term of
minimum probability of error by directly minimising the BER cost
function. Also the MBER MUD is able to support more users than
the number of receiving antennas, whereas the rest of MUDs fail in
this scenario. In this paper the performance of various MUD
techniques is verified for the correlated MIMO channel models based
on IEEE 802.16n standard.
Abstract: In this paper, the implementation of low power,
high throughput convolutional filters for the one dimensional
Discrete Wavelet Transform and its inverse are presented. The
analysis filters have already been used for the implementation of a
high performance DWT encoder [15] with minimum memory
requirements for the JPEG 2000 standard. This paper presents the
design techniques and the implementation of the convolutional filters
included in the JPEG2000 standard for the forward and inverse DWT
for achieving low-power operation, high performance and reduced
memory accesses. Moreover, they have the ability of performing
progressive computations so as to minimize the buffering between
the decomposition and reconstruction phases. The experimental
results illustrate the filters- low power high throughput characteristics
as well as their memory efficient operation.
Abstract: In this paper, a vision based system has been used for
controlling an industrial 3P Cartesian robot. The vision system will
recognize the target and control the robot by obtaining images from
environment and processing them. At the first stage, images from
environment are changed to a grayscale mode then it can diverse and
identify objects and noises by using a threshold objects which are
stored in different frames and then the main object will be
recognized. This will control the robot to achieve the target. A vision
system can be an appropriate tool for measuring errors of a robot in a
situation where the experimental test is conducted for a 3P robot.
Finally, the international standard ANSI/RIA R15.05-2 is used for
evaluating the path-related characteristics of the robot. To evaluate
the performance of the proposed method experimental test is carried
out.
Abstract: In this paper, creep constitutive equations of base
(Parent) and weld materials of the weldment for cold-drawn 304L
stainless steel have been obtained experimentally. For this purpose,
test samples have been generated from cold drawn bars and weld
material according to the ASTM standard. The creep behavior and
properties have been examined for these materials by conducting uniaxial
creep tests. Constant temperatures and constant load uni-axial
creep tests have been carried out at two high temperatures, 680 and
720 oC, subjected to constant loads, which produce initial stresses
ranging from 240 to 360 MPa. The experimental data have been used
to obtain the creep constitutive parameters using numerical
optimization techniques.
Abstract: This paper shows the results of empirical research. It
presents experiences of Polish companies from the Podkarpackie
voivodeship connected with implementing EMS according to the
requirements of the ISO 14001 international standard. The incentives
to introduce and certify organizational eco-innovation, which formal
EMSs are treated as, are presented in this paper.
Abstract: The present paper discusses the selection of process
parameters for obtaining optimal nanocrystallites size in the CuOZrO2
catalyst. There are some parameters changing the inorganic
structure which have an influence on the role of hydrolysis and
condensation reaction. A statistical design test method is
implemented in order to optimize the experimental conditions of
CuO-ZrO2 nanoparticles preparation. This method is applied for the
experiments and L16 orthogonal array standard. The crystallites size
is considered as an index. This index will be used for the analysis in
the condition where the parameters vary. The effect of pH, H2O/
precursor molar ratio (R), time and temperature of calcination,
chelating agent and alcohol volume are particularity investigated
among all other parameters. In accordance with the results of
Taguchi, it is found that temperature has the greatest impact on the
particle size. The pH and H2O/ precursor molar ratio have low
influences as compared with temperature. The alcohol volume as
well as the time has almost no effect as compared with all other
parameters. Temperature also has an influence on the morphology
and amorphous structure of zirconia. The optimal conditions are
determined by using Taguchi method. The nanocatalyst is studied by
DTA-TG, XRD, EDS, SEM and TEM. The results of this research
indicate that it is possible to vary the structure, morphology and
properties of the sol-gel by controlling the above-mentioned
parameters.
Abstract: A new code synchronization algorithm is proposed in
this paper for the secondary cell-search stage in wideband CDMA
systems. Rather than using the Cyclically Permutable (CP) code in the
Secondary Synchronization Channel (S-SCH) to simultaneously
determine the frame boundary and scrambling code group, the new
synchronization algorithm implements the same function with less
system complexity and less Mean Acquisition Time (MAT). The
Secondary Synchronization Code (SSC) is redesigned by splitting into
two sub-sequences. We treat the information of scrambling code group
as data bits and use simple time diversity BCH coding for further
reliability. It avoids involved and time-costly Reed-Solomon (RS)
code computations and comparisons. Analysis and simulation results
show that the Synchronization Error Rate (SER) yielded by the new
algorithm in Rayleigh fading channels is close to that of the
conventional algorithm in the standard. This new synchronization
algorithm reduces system complexities, shortens the average
cell-search time and can be implemented in the slot-based cell-search
pipeline. By taking antenna diversity and pipelining correlation
processes, the new algorithm also shows its flexible application in
multiple antenna systems.
Abstract: The non-destructive testing of launch tube weld with
radiography was investigated and evaluated with AWS D1.1
standard. The paper started with preparation of launch tube and
radiographic inspection. X-Ray inspection then was done and gotten
the result. The judgment of inspection results were concluded by
certified person and finally, the evaluation with AWS D1.1 standard
was conducted as well.
The result shown that weld position P1 was not conformed to
AWS D1.1 which allowed size of incomplete penetration did not
exceed 4 mm. The other welds were corresponded to as mentioned
standard. Additionally, the corrective actions for incomplete
penetration either provided for future actions.
Abstract: In the visual servoing systems, the data obtained by
Visionary is used for controlling robots. In this project, at first the
simulator which was proposed for simulating the performance of a
6R robot before, was examined in terms of software and test, and in
the proposed simulator, existing defects were obviated. In the first
version of simulation, the robot was directed toward the target object only in a Position-based method using two cameras in the
environment. In the new version of the software, three cameras were used simultaneously. The camera which is installed as eye-inhand on the end-effector of the robot is used for visual servoing in a
Feature-based method. The target object is recognized according to
its characteristics and the robot is directed toward the object in compliance with an algorithm similar to the function of human-s
eyes. Then, the function and accuracy of the operation of the robot are examined through Position-based visual servoing method using
two cameras installed as eye-to-hand in the environment. Finally, the obtained results are tested under ANSI-RIA R15.05-2 standard.
Abstract: The IEEE 802.11e which is an enhanced version of the 802.11 WLAN standards incorporates the Quality of Service (QoS) which makes it a better choice for multimedia and real time applications. In this paper we study various aspects concerned with 802.11e standard. Further, the analysis results for this standard are compared with the legacy 802.11 standard. Simulation results show that IEEE 802.11e out performs legacy IEEE 802.11 in terms of quality of service due to its flow differentiated channel allocation and better queue management architecture. We also propose a method to improve the unfair allocation of bandwidth for downlink and uplink channels by varying the medium access priority level.
Abstract: This paper presents the findings of two experiments that were performed on the Redundancy in Wireless Connection Model (RiWC) using the 802.11b standard. The experiments were simulated using OPNET 11.5 Modeler software. The first was aimed at finding the maximum number of simultaneous Voice over Internet Protocol (VoIP) users the model would support under the G.711 and G.729 codec standards when the packetization interval was 10 milliseconds (ms). The second experiment examined the model?s VoIP user capacity using the G.729 codec standard along with background traffic using the same packetization interval as in the first experiment. To determine the capacity of the model under various experiments, we checked three metrics: jitter, delay and data loss. When background traffic was added, we checked the response time in addition to the previous three metrics. The findings of the first experiment indicated that the maximum number of simultaneous VoIP users the model was able to support was 5, which is consistent with recent research findings. When using the G.729 codec, the model was able to support up to 16 VoIP users; similar experiments in current literature have indicated a maximum of 7 users. The finding of the second experiment demonstrated that the maximum number of VoIP users the model was able to support was 12, with the existence of background traffic.
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: To compare Healing Effects of an
Ayurvedic Preparation and Silver Sulfadiazine on burn wounds in
Albino Rats.
Methods: Albino rats– 30 male / female rats weighing between
150-200 g were used in the study. They were individually housed and
maintained on normal diet and water ad libitum. Partial thickness
burn wounds were inflicted, on overnight-starved animals under
pentobarbitone (30mg/kg, i.p.) anaesthesia, by pouring hot molten
wax at 80oC into a plastic cylinder of 300 mm2 circular openings
placed on the shaven back of the animal. Apart from the drugs under
investigation no local/ systemic chemotherapeutic cover will be
provided to animals. All the animals were assessed for the percentage
of wound contraction, signs of infection, scab formation and
histopathological examination.
Results: Percentage of wound healing was significantly better in
the test ointment group compared to the standard. Signs of infection
were observed in more animals in the test ointment group compared
to the standard. Scab formation also took place earlier in the test
ointment group compared to standard. Epithelial regeneration and
healing profile was better in the test ointment compared to the
standard. Moreover the test ointment group did not show any raised
margins in the wound or blackish discoloration as was observed in
silver sulfadiazine group.
Conclusion: The burn wound healing effect of the ayurvedic
ointment under study is better in comparison to standard therapy of
silver sulfadiazine. The problem of infection encountered with the
test ointment can be overcome by changing the concentrations and
proportions of the ingredients in the test ointment which constitutes
the further plan of the study.
Abstract: This study investigated the number of Aedes larvae,
the key breeding sites of Aedes sp., and the relationship between
climatic factors and the incidence of DHF in Samui Islands. We
conducted our questionnaire and larval surveys from randomly
selected 105 households in Samui Islands in July-September 2006.
Pearson-s correlation coefficient was used to explore the primary
association between the DHF incidence and all climatic factors.
Multiple stepwise regression technique was then used to fit the
statistical model. The results showed that the positive indoor
containers were small jars, cement tanks, and plastic tanks. The
positive outdoor containers were small jars, cement tanks, plastic
tanks, used cans, tires, plastic bottles, discarded objects, pot saucers,
plant pots, and areca husks. All Ae. albopictus larval indices (i.e., CI,
HI, and BI) were higher than Ae. aegypti larval indices in this area.
These larval indices were higher than WHO standard. This indicated
a high risk of DHF transmission at Samui Islands. The multiple
stepwise regression model was y = –288.80 + 11.024xmean temp. The
mean temperature was positively associated with the DHF incidence
in this area.