|
Home>Products>Journals
and Reviews>I.Re.Co.S.>Latest issue
International Review on
Computers and Software - Papers
Automatic
Feature Extraction to COSMOS-7 Content Models
by M. J. Parmar, M. C. Angelides
Abstract
- Extracting and modeling multimedia content in MPEG-7 is a laborious task as
most systems use manual or partially automatic extraction methods. Systems that
use partially automatic extraction techniques tend to use a limited set of
features that are of little or no use to other applications negating the purpose
of the MPEG-7 standard. In this paper we present our automatic extraction
methods for the structural components of media. In particular, we extract from
scenes, shots, objects and spatial and temporal relationships. These features
are then processed and incorporated into an MPEG-7 content model that is rich
enough to facilitate content filtering.
Copyright © 2006 Praise Worthy Prize S.r.l. - All rights reserved
Keywords:
Multimedia content modeling, feature extraction, MPEG-7.
A
Fuzzy Algorithm for Real-Time Scheduling of Soft Periodic Tasks
by M. Sabeghi, M. Naghibzadeh
Abstract
- Many
scheduling algorithms have been studied to guarantee the time constraints of
real-time processes. Scheduling decision of these algorithms is usually based on
parameters which are assumed to be crisp. However, in many circumstances the
values of these parameters are vague. The vagueness of parameters suggests that
we make use of fuzzy logic to decide in what order the requests should be
executed to better utilize the system and as a result reduce the chance of a
request being missed. We have proposed a new fuzzy algorithm called highest
fuzzy priority first. The performance of this algorithm is compared with the
well-known earliest deadline first (EDF) algorithm as well as least laxity first
(LLF) algorithm through simulation. The simulations were divided into two parts.
Firs, the tasks were considered to be preemptable, and second tasks were assumed
to be non-preemptable. Simulation results show that this fuzzy approach
outperforms the EDF and LLF. It is concluded that the proposed fuzzy approach is
very promising and it has the potential to be considered for future research.
Copyright © 2006 Praise Worthy Prize S.r.l. - All rights reserved
Keywords:
Fuzzy real time scheduling, EDF, LLF, MFDF, MFLF.
An
Integrated Metrics Based Approach for Usability Engineering
by H. S. Jabbar, T. V. Gopal
Abstract
- Usability Assessment (UA) is a method that is used to elicit the quality of
software products through regular tests with potential users by a variety of
methods and models. However, existing methods either falls in qualitative
methods, which generally estimate users opinion of a software product which
called (subjective assessment) or falls in quantitative methods, which focus on
the performance measurement of the software product which is called (objective
assessment). In this paper, we have proposed an Integrated Metrics Based
Approach For Usability Engineering (IMAUE), which combine both qualitative and
quantitative factors to complement the analysis process. Qualitatively, we have
contributed to the factors of (1) conducting UA with fewer requirements by means
of time, budget and resources (2) establish 2-way interaction between the user
and the tester by interviewing users responses in the UA (3) employing dynamic
tasks to fill the gap of communication and convert the UA into a discovery
process. Quantitatively, we have proposed various models and metrics that can be
used to measure the level of usability, those metrics are (1) interviewing time
(2) number of errors (3) task accomplishment (4) time for the task and (5) users
satisfaction. In order to clarify the assumptions of the proposed model, we have
validated our model against two experimental case studies.
Copyright © 2006 Praise Worthy Prize S.r.l. - All rights reserved
Keywords:
UA, literature overview, research needs, IMAUE, case studies.
Network Priority Mapping Using Dynamic RT-CORBA Scheduling Service
by T. Guesmi, S. Hasnaoui, H. Rezig
Abstract
- Distributed computer control in complex embedded systems and their software
components gain complexity when these systems are equipped with many
microcontrollers which oversee diverse electronic control units connecting
hundreds or thousands of analog and digital sensors and actuators. These systems
need new inter-object communication patterns thus QoS-enabled middleware
services and mechanisms have begun to emerge. It is also, widely known that
Control Area Networks (CAN) are used in real-time, distributed and parallel
processing which cover manufacture plants, humanoid robots, networking fields.
We show how prioritization of messages over the physical CAN network can be
achieved, when adopting the use of RT-CORBA distributed scheduling service which
implements a dynamic scheduling policy to achieve end-to-end predictability and
performance.
Copyright © 2006 Praise Worthy Prize S.r.l. - All rights reserved
Keywords:
Real-Time Scheduling, Earliest Deadline First, CAN Bus, Intermediate Deadline,
Network Priority Mapping.
by L. V. Stoimenov, E. O. Kajan, S. Djordjevic-Kajan
Abstract
- Semantic interoperability between applications, systems, organizations, and
communities appears today as a crucial feature that should allow their
intelligent communications with a minimum or completely without human
interventions. In this paper we introduce our common concept for a semantic
interoperable middleware kernel that may satisfy the requirements of many
different applications. Finally, a short overview of implementation for two
different domains (GIS and B2B) has given.
Copyright © 2006 Praise Worthy Prize S.r.l. - All rights reserved
Keywords:
Interoperability, semantics, ontologies, framework.
Multicast Retransmission Strategies for Content Delivery in Heterogeneous Mobile
Internet Environments
by N. Reyes, J. Mahnke, I. Miloucheva, K. Jonas
Abstract
- For efficient deployment of new reliable multicast applications in
heterogeneous mobile Internet environments, appropriate retransmission
strategies are proposed.
The focus is the minimization of the protocol overhead for reliable transport
taking into account behavior in mobile networks (f.i. loss and handover
behavior) and application requirements (such as carousel file transfer,
one-to-many download and media streaming combined with recording).
The proposed techniques are designed as building blocks for localized multicast
error control supported by access routers. Considering IETF RMT standardization
work, the discussed retransmission approaches can be used for flexible
configuration of tree-based reliable multicast protocols in converged wired and
wireless Internet environment.
The implementation is based on Linux IPv6 environment. Simulations in ns2
focusing on the benefits of the proposed multicast retransmission schemes for
particular application scenarios are presented
.
Copyright © 2006 Praise Worthy Prize S.r.l. - All rights reserved
Keywords:
reliable multicast, retransmission, carousel, one-to-many download, error
control, network simulation.
Stability and Performance Analysis of Clock Synchronization in FlexRay
by A. Hanzlik
Abstract
- This paper presents a case study on the performance of a distributed clock
synchronization algorithm used in FlexRay, a communication protocol designed to
meet the requirements of dependable, fault-tolerant real-time applications. The
FlexRay industry consortium drives forward the standardization of a
fault-tolerant communication system for advanced automotive applications. In
this case study we will analyze two different configurations for typical
automotive applications by means of simulation. The focus of the simulation
experiments is the assessment of performance and stability of the FlexRay clock
synchronization algorithm in the presence of varying clock drift rates. For the
analysis we will use SIDERA, a simulation model for time-triggered distributed
systems.
Copyright © 2006 Praise Worthy Prize S.r.l. - All rights reserved
Keywords:
Clock Synchronization, Global Time, Time-Triggered Systems, Clock drift,
Real-Time Communication Protocol.
Tolerating DDoS
Attacks Using Dynamic Rate Limiting
by K. Kumar, R. C. Joshi, K. Singh
Abstract
- Distributed Denial of Service (DDoS) attacks pose a serious threat to
availability of Internet Services. Several schemes have been proposed for
countering DDoS attacks directed at an Internet Server, but they suffer from a
range of problems, some of them being impractical and others not being effective
against these attacks. We propose a dynamic rate throttling technique that will
greatly minimize the impact of attack. The basic mechanism is to have
monitoring, rate limiting and filtering at edges of ISPs. The participating
routers, start there function after getting a signal from a server under attack.
Our scheme is invoked only during attack times, and is able to mitigate attack
traffic through dynamic filtering. Server instructs edge routers to rate limit
the traffic according to the share of traffic which is being passed through
particular edge router. The solution proposed is an ISP level solution which is
practical enough to be implemented. We simulate the scheme in NS-2 in Linux
System. We use an Internet type topology to test our scheme. Web and FTP traffic
was generated to evaluate the effectiveness of scheme. Our scheme shows good
improvement over static router throttling techniques which were proposed
earlier. Hence we believe that the scheme proposed in this paper is a promising
approach to stop DDoS attacks.
Copyright © 2006 Praise Worthy Prize S.r.l. - All rights reserved
Keywords:
Congestion control, Distributed Denial of service, Network level security and
protection, router throttling.
Fully Distributed
Security Architecture for MANET
by A. Shajin Nargunam, M. P. Sebastian
Abstract
- Secured communication in mobile ad hoc network is a crucial issue due to
dynamic nature of the network topology. Due to lack of centralized control,
issuing certificates from a centralized certification agent is not possible in
ad hoc network. The major problem in providing security services in such
infrastructure less networks is how to manage the cryptographic keys that are
needed In MANET any node may compromise the packet routing functionality by
disrupting the route discovery process.. These unique characteristics of mobile
ad hoc networks causes a number of nontrivial challenges to security design such
as open network architecture, shared wireless medium, stringent resource
constraints and highly dynamic topology. These challenges make a cause for
building multi-fence security solution that achieves both extensive protection
and desirable network performance. We propose a novel cluster based security
scheme to protect mobile ad hoc network link layer and network layer operations
of delivering packet over the multihop wireless channel. The dynamic network
topology can be managed efficiently by the proposed cluster based architecture.
A well-behaving node becomes a cluster member after the initial trust
verification process. The membership validity period of a node depends on how
long it has stayed and behaved well. Non overlapping clusters are created using
the dynamic cluster creation algorithm. The cluster construction is fully
distributed so efficiency is not degraded by node mobility.
Copyright © 2006 Praise Worthy Prize S.r.l. - All rights reserved
Keywords:
Cluster, Denial of Service and MANET Security.
Recognition of Bilingual Segmented Characters (Gurmukhi and Roman)
by R. Dhir, C. Singh
Abstract
- Recognition of bilingual script in an image of a document page is of primary
importance for a system processing bilingual document. In this paper two
essential sub stages of recognition phase, feature extraction and classification
has been discussed for segmented Gurmukhi and Roman characters. Two classifier
schemes have been proposed for recognition of machine printed Bilingual
characters. It has been found that structural and statistical features provide
very good results. With both the classifiers a good accuracy is achieved for
segmented Gurmukhi and Roman characters without preprocessing.
Copyright © 2006 Praise Worthy Prize S.r.l. - All rights reserved
Keywords:
Bilingual Script, Neuro Fuzzy, nearest neighbor, segmentation, simplified fuzzy.
| 
