Abstract: The noticeable advance in the area of computer technology has paved the way for the invention of powerful mobile devices. However, limited storage, short battery life, and relatively low computational power define the major problems of such devices. Due to the ever increasing computational requirements, such devices may fail to process needed tasks under certain constraints. One of the proposed solutions to this drawback is the introduction of Collaborative Computing, a new concept dealing with the distribution of computational tasks amongst several handhelds. This paper introduces the basics of Collaborative Computing, and proposes a new protocol that aims at managing and optimizing computing tasks in Ad-Hoc Collaborative Computing Environments.
Abstract: Variable digital filters are useful for various signal processing and communication applications where the frequency characteristics, such as fractional delays and cutoff frequencies, can be varied. In this paper, we propose a design method of variable FIR digital filters with an approximate linear phase characteristic in the passband. The proposed variable FIR filters have some large attenuation in stopband and their large attenuation can be varied by spectrum parameters. In the proposed design method, a quasi-equiripple characteristic can be obtained by using an iterative weighted least square method. The usefulness of the proposed design method is verified through some examples.
Abstract: Recently, Denial of Service(DoS) attacks and Distributed DoS(DDoS) attacks which are stronger form of DoS attacks from plural hosts have become security threats on the Internet. It is important to identify the attack source and to block attack traffic as one of the measures against these attacks. In general, it is difficult to identify them because information about the attack source is falsified. Therefore a method of identifying the attack source by tracing the route of the attack traffic is necessary. A traceback method which uses traffic patterns, using changes in the number of packets over time as criteria for the attack traceback has been proposed. The traceback method using the traffic patterns can trace the attack by matching the shapes of input traffic patterns and the shape of output traffic pattern observed at a network branch point such as a router. The traffic pattern is a shapes of traffic and unfalsifiable information. The proposed trace methods proposed till date cannot obtain enough tracing accuracy, because they directly use traffic patterns which are influenced by non-attack traffics. In this paper, a new traffic pattern matching method using Independent Component Analysis(ICA) is proposed.
Abstract: This paper addresses a current problem that occurs among Thai internet service providers with regard to bandwidth network quality management. The IPSTAR department of Telecom Organization of Thailand public company (TOT); the largest internet service provider in Thailand, is the case study to analyze the problem that exists. The Internet bandwidth network quality management (iBWQM) framework is mainly applied to the problem that has been found. Bandwidth management policy (BMP) and quality of service (QoS) are two antecedents of iBWQM. This paper investigates internet user behavior, marketing demand and network operation views in order to determine bandwidth management policy (e.g. quota management, scheduling and malicious management). The congestion of bandwidth is also analyzed to enhance quality of service (QoS). Moreover, the iBWQM framework is able to improve the quality of service and increase bandwidth utilization, minimize complaint rate concerns to slow speed, and provide network planning guidelines through Thai Internet services providers.
Abstract: The main aims in this research are to study the solid
waste generation in the Faculty of Engineering and Built
Environment in the UKM and at the same time to determine
composition and some of the waste characteristics likewise: moisture
content, density, pH and C/N ratio. For this purpose multiple
campaigns were conducted to collect the wastes produced in all
hostels, faculties, offices and so on, during 24th of February till 2nd
of March 2009, measure and investigate them with regard to both
physical and chemical characteristics leading to highlight the
necessary management policies. Research locations are Faculty of
Engineering and the Canteen nearby that. From the result gained, the
most suitable solid waste management solution will be proposed to
UKM. The average solid waste generation rate in UKM is 203.38
kg/day. The composition of solid waste generated are glass, plastic,
metal, aluminum, organic and inorganic waste and others waste.
From the laboratory result, the average moisture content, density, pH
and C/N ratio values from the solid waste generated are 49.74%,
165.1 kg/m3, 5.3, and 7:1 respectively. Since, the food waste (organic
waste) were the most dominant component, around 62% from the
total waste generated hence, the most suitable solid waste
management solution is composting.
Abstract: This research is to study the performance of heat
pump dryer for drying of kaffir lime leaves under different media and
to compare the color values and essential oil content of final products
after drying. In the experiments, kaffir lime leaves were dried in the
closed-loop system at drying temperatures of 40, 50 and 60 oC. The
drying media used in this study were hot air, CO2 and N2 gases. The
velocity of drying media in the drying chamber was 0.4 m/s with
bypass ratio of 30%. The initial moisture content of kaffir lime leaves
was approximately 180-190 % d.b. It was dried until down to a final
moisture content of 10% d.b. From the experiments, the results
showed that drying rate, the coefficient of performance (COP) and
specific energy consumption (SEC) depended on drying temperature.
While drying media did not affect on drying rate. The time for kaffir
lime leaves drying at 40, 50 and 60 oC was 10, 5 and 3 hours,
respectively. The performance of the heat pump system decreased
with drying temperature in the range of 2.20-3.51. In the aspect of
final product color, the greenness and overall color had a great
change under drying temperature at 60 oC rather than drying at 40
and 50 oC. When compared among drying media, the greenness and
overall color of product dried with hot air at 60 oC had a great change
rather than dried with CO2 and N2.
Abstract: The home in these days has not one computer connected to the Internet but rather a network of many devices within the home, and that network might be connected to the Internet. In such an environment, the potential for attacks is greatly increased. The general security technology can not apply because of the use of various wired and wireless network, middleware and protocol in digital home environment and a restricted system resource of home information appliances. To offer secure home services home network environments have need of access control for various home devices and information when users want to access. Therefore home network access control for user authorization is a very important issue. In this paper we propose access control model using RBAC in home network environments to provide home users with secure home services.
Abstract: Nowadays, efficiency, effectiveness and economy are regarded as the main objectives of managers and the secret of the continuity of an organization in competing economy. In such competing settings, it is essential that the management of an organization has not been neglected and been obliged to identify quickly the opportunities for improving the operation of organization and remove the shortcomings of their managed system in order to use the opportunities for development. Operational auditing is a useful tool for system adjustment and leading an organization toward its objectives. Operational auditing is indeed a viewpoint which identifies the causes of insufficiencies, weaknesses and deficiencies of system and plans to eliminate them. Operational auditing is useful in the effectiveness and optimization of executive managers- decisions and increasing the efficiency and economy of their performance in the future and prevents the waste and incorrect use of resources. Evidence shows that operational auditing is used at a limited level in Iran. This matter raises some questions like the following ones in the minds. Why do a limited number of corporations use operational auditing? Which factors can guarantee its full implementation? What obstacles are there in its implementation? The purpose of this article is to determine executive objectives, the operation domain of operational auditing, the components of operational auditing and the executive obstacles to operational auditing in Iran.
Abstract: Service discovery is a very important component of Service Oriented Architectures (SOA). This paper presents two alternative approaches to customise the query results of private service registry such as Universal Description, Discovery and Integration (UDDI). The customisation is performed based on some pre-defined and/or real-time changing parameters. This work identifies the requirements, designs and additional mechanisms that must be applied to UDDI in order to support this customisation capability. We also detail the implements of the approaches and examine its performance and scalability. Based on our experimental results, we conclude that both approaches can be used to customise registry query results, but by storing personalization parameters in external resource will yield better performance and but less scalable when size of query results increases. We believe these approaches when combined with semantics enabled service registry will enhance the service discovery methods within a private UDDI registry environment.
Abstract: The plant world is the source of many medicines.
Recently, researchers have estimated that there are approximately
400,000 plant species worldwide, of which about a quarter or a third
have been used by societies for medicinal purposes. The human uses
of plants for thousands of years to treat various ailments, in many
developing countries, much of the population trust in traditional
doctors and their collections of medicinal plants to treat them.
Essential oils have many therapeutic properties. In herbal medicine,
they are used for their antiseptic properties against infectious
diseases of fungal origin, against dermatophytes, those of bacterial
origin. The aim of our study is to determine the antimicrobial effect
of essential oils of the plant Trigonella focnum greacum on some
pathogenic bacteria, it is a medicinal plant used in traditional
therapy. The test adopted is based on the diffusion method on solid
medium (Antibiogram), this method determines the sensitivity or
resistance of a microorganism vis-à-vis the extract studied. Our study
reveals that the essential oil of the plant Trigonella focnum greacum
has a different effect on the resistance of germs. For staphiloccocus
Pseudomonnas aeroginosa and Krebsilla, are moderately sensitive
strains, also Escherichia coli and Candida albicans represents a high
sensitivity. By against Proteus is a strain that represents a weak
sensitivity.
Abstract: power-line networks are promise infrastructure for
broadband services provision to end users. However, the network
performance is affected by stochastic channel changing which is due
to load impedances, number of branches and branched line lengths. It
has been proposed that multi-carrier modulations techniques such as
orthogonal frequency division multiplexing (OFDM), Multi-Carrier
Spread Spectrum (MC-SS), wavelet OFDM can be used in such
environment. This paper investigates the performance of different
indoor topologies of power-line networks that uses MC-SS
modulation scheme.It is observed that when a branch is added in the
link between sending and receiving end of an indoor channel an
average of 2.5dB power loss is found. In additional, when the branch
is added at a node an average of 1dB power loss is found.
Additionally when the terminal impedances of the branch change
from line characteristic impedance to impedance either higher or
lower values the channel performances were tremendously improved.
For example changing terminal load from characteristic impedance
(85 .) to 5 . the signal to noise ratio (SNR) required to attain the
same performances were decreased from 37dB to 24dB respectively.
Also, changing the terminal load from channel characteristic
impedance (85 .) to very higher impedance (1600 .) the SNR
required to maintain the same performances were decreased from
37dB to 23dB. The result concludes that MC-SS performs better
compared with OFDM techniques in all aspects and especially when
the channel is terminated in either higher or lower impedances.
Abstract: This paper explores an application of an adaptive learning mechanism for robots based on the natural immune system. Most of the research carried out so far are based either on the innate or adaptive characteristics of the immune system, we present a combination of these to achieve behavior arbitration wherein a robot learns to detect vulnerable areas of a track and adapts to the required speed over such portions. The test bed comprises of two Lego robots deployed simultaneously on two predefined near concentric tracks with the outer robot capable of helping the inner one when it misaligns. The helper robot works in a damage-control mode by realigning itself to guide the other robot back onto its track. The panic-stricken robot records the conditions under which it was misaligned and learns to detect and adapt under similar conditions thereby making the overall system immune to such failures.
Abstract: Most of the biclustering/projected clustering algorithms are based either on the Euclidean distance or correlation coefficient which capture only linear relationships. However, in many applications, like gene expression data and word-document data, non linear relationships may exist between the objects. Mutual Information between two variables provides a more general criterion to investigate dependencies amongst variables. In this paper, we improve upon our previous algorithm that uses mutual information for biclustering in terms of computation time and also the type of clusters identified. The algorithm is able to find biclusters with mixed relationships and is faster than the previous one. To the best of our knowledge, none of the other existing algorithms for biclustering have used mutual information as a similarity measure. We present the experimental results on synthetic data as well as on the yeast expression data. Biclusters on the yeast data were found to be biologically and statistically significant using GO Tool Box and FuncAssociate.
Abstract: The survival of publicly listed companies largely
depends on their stocks being liquidly traded. This goal can be
achieved when new investors are attracted to invest on companies-
stocks. Among different groups of investors, individual investors are
generally less able to objectively evaluate companies- risks and
returns, and tend to be emotionally biased in their investing
decisions. Therefore their decisions may be formed as a result of
perceived risks and returns, and influenced by companies- images.
This study finds that perceived risk, perceived returns and trust
directly affect individual investors- trading decisions while attitude
towards brand partially mediates the relationships. This finding
suggests that, in courting individual investors, companies still need to
perform financially while building a good image can result in their
stocks being accepted quicker than the stocks of good performing
companies with hidden images.
Abstract: The whole-cell protein-profiling technique was
evaluated for studying differences in banding pattern of three
different species of Cyanobacteria i.e. Anabaena fertilissima,
Aulosira fertilissima and Westiellopsis prolifica under the influence
of four different pesticides-2,4-D (Ethyl Ester of 2,4-Dichloro
Phenoxy Acetic Acid), Pencycuron (N-[(4-chlorophenyl)methyl]-Ncyclopentyl-
N'–phenylurea), Endosulfan (6,7,8,9,10,10hexachloro-
1,5,5a,6,9,9a-hexahydro-6,9-methano-2,4,3-benzodioxathiepine-3-
oxide) and Tebuconazole (1-(4-Chlorophenyl)-4,4-dimethyl-3-(1,2,4-
triazol-1-ylmethyl)pentan-3-ol). Whole-cell extracts were obtained by
sonication treatment (Sonifier cell disruptor -Branson Digital Sonifier
S-450D, USA) and were analyzed by sodium dodecyl sulfate
polyacrylamide gel electrophoresis (SDS-PAGE). SDS-PAGE
analyses of the total protein profile of Anabaena fertilissima,
Aulosira fertilissima and Westiellopsis prolifica showed a linear
decrease in the protein content with increasing pesticide stress when
administered to different concentrations of 2, 4-D, Pencycuron,
Endosulfan and Tebuconazole. The results indicate that different
stressors exert specific effects on cyanobacterial protein synthesis.
Abstract: Representation and description of object shapes by the
slopes of their contours or borders are proposed. The idea is to capture
the essence of the features that make it easier for a shape to be
stored, transmitted, compared and recognized. These features must
be independent of translation, rotation and scaling of the shape. A
approach is proposed to obtain high performance, efficiency and to
merge the boundaries into sequence of straight line segments with
the fewest possible segments. Evaluation on the performance of the
proposed method is based on its comparison with established method
of object shape description.
Abstract: Protection of slope and embankment from erosion has
become an important issue in Bangladesh. The constructions of
strong structures require large capital, integrated designing, high
maintenance cost. Strong structure methods have negative impact on
the environment and sometimes not function for the design period.
Plantation of vetiver system along the slopes is an alternative
solution. Vetiver not only serves the purpose of slope protection but
also adds green environment reducing pollution. Vetiver is available
in almost all the districts of Bangladesh. This paper presents the
application of vetiver system with geo-jute, for slope protection and
erosion control of embankments and slopes. In-situ shear tests have
been conducted on vetiver rooted soil system to find the shear
strength. The shear strength and effective soil cohesion of vetiver
rooted soil matrix are respectively 2.0 times and 2.1 times higher than
that of the bared soil. Similar trends have been found in direct shear
tests conducted on laboratory reconstituted samples. Field trials have
been conducted in road embankment and slope protection with
vetiver at different sites. During the time of vetiver root growth the
soil protection has been accomplished by geo-jute. As the geo-jute
degrades with time, vetiver roots grow and take over the function of
geo-jutes. Slope stability analyses showed that vegetation increase
the factor of safety significantly.
Abstract: In contrast to conventional generators, self-excited induction generators are found to be most suitable machines for wind energy conversion in remote and windy areas due to many advantages over grid connected machines. This papers presents a Self-Excited Induction Generator (SEIG) driven by wind turbine and supplying an induction motor which is coupled to a centrifugal pump. A method to describe the steady state performance based on nodal analysis is presented. Therefore the advanced knowledge of the minimum excitation capacitor value is required. The effects of variation of excitation capacitance on system and rotor speed under different loading conditions have been analyzed and considered to optimize induction motor pump performances.
Abstract: The copper flotation tailings from Konkola Copper
mine in Nchanga, Zambia were used in the study. The purpose of this
study was to determine the leaching characteristics of the tailings
material prior and after the physical beneficiation process is
employed. The Knelson gravity concentrator (KC-MD3) was used for
the beneficiation process. The copper leaching efficiencies and
impurity co-extraction percentages in both the upgraded and the raw
feed material were determined at different pH levels and temperature.
It was observed that the copper extraction increased with an increase
in temperature and a decrease in pH levels. In comparison to the raw
feed sample, the upgraded sample reported a maximum copper
extraction of 69% which was 9%, higher than raw feed % extractions.
The impurity carry over was reduced from 18% to 4 % on the
upgraded sample. The reduction in impurity co-extraction was as a
result of the removal of the reactive gangue elements during the
upgrading process, this minimized the number of side reaction
occurring during leaching.
Abstract: A DC-to-DC converter for applications involving a
source with widely varying voltage conditions with loads requiring
constant voltage from full load down to no load is presented.
The switching regulator considered is a Buck converter with Pulse
Skipping Modulation control whereby pulses applied to the switch
are blocked or released on output voltage crossing a predetermined
value. Results of the study on the performance of regulator circuit
are presented. The regulator regulates over a wide input voltage range
with slightly higher ripple content and good transient response. Input
current spectrum indicates a good EMI performance with crowding
of components at low frequency range.