Abstract: In networks, mainly small and medium-sized businesses benefit from the knowledge, experiences and solutions offered by experts from industry and science or from the exchange with practitioners. Associations which focus, among other things, on networking, information and knowledge transfer and which are interested in supporting such cooperations are especially well suited to provide such networks and the appropriate web platforms. Using METORA as an example – a project developed and run by the Federal Association for Information Economy, Telecommunications and New Media e.V. (BITKOM) for the Federal Ministry of Economics and Technology (BMWi) – This paper will discuss how associations and other network organizations can achieve this task and what conditions they have to consider.
Abstract: An end-member selection method for spectral unmixing that is based on Particle Swarm Optimization (PSO) is developed in this paper. The algorithm uses the K-means clustering algorithm and a method of dynamic selection of end-members subsets to find the appropriate set of end-members for a given set of multispectral images. The proposed algorithm has been successfully applied to test image sets from various platforms such as LANDSAT 5 MSS and NOAA's AVHRR. The experimental results of the proposed algorithm are encouraging. The influence of different values of the algorithm control parameters on performance is studied. Furthermore, the performance of different versions of PSO is also investigated.
Abstract: Nevertheless the widespread application of finite
mixture models in segmentation, finite mixture model selection is
still an important issue. In fact, the selection of an adequate number
of segments is a key issue in deriving latent segments structures and
it is desirable that the selection criteria used for this end are effective.
In order to select among several information criteria, which may
support the selection of the correct number of segments we conduct a
simulation study. In particular, this study is intended to determine
which information criteria are more appropriate for mixture model
selection when considering data sets with only categorical
segmentation base variables. The generation of mixtures of
multinomial data supports the proposed analysis. As a result, we
establish a relationship between the level of measurement of
segmentation variables and some (eleven) information criteria-s
performance. The criterion AIC3 shows better performance (it
indicates the correct number of the simulated segments- structure
more often) when referring to mixtures of multinomial segmentation
base variables.
Abstract: Urban disaster risks and vulnerabilities are great problems for Turkey. The annual loss of life and property through disaster in the world-s major metropolitan areas is increasing. Urban concentrations of the poor and less-informed in environmentally fragile locations suffer the impact of disaster disproportionately. Gecekondu (squatter) developments will compound the inherent risks associated with high-density environments, in appropriate technologies, and inadequate infrastructure. On the other hand, there are many geological disadvantages such as sitting on top of active tectonic plate boundaries, and why having avalanche, flood, and landslide and drought prone areas in Turkey. However, this natural formation is inevitable; the only way to survive in such a harsh geography is to be aware of importance of these natural events and to take political and physical measures. The main aim of this research is to bring up the magnitude of natural hazard risks in Izmir built-up zone, not being taken into consideration adequately. Because the dimensions of the peril are not taken seriously enough, the natural hazard risks, which are commonly well known, are not considered important or they are being forgotten after some time passes. Within this research, the magnitude of natural hazard risks for Izmir is being presented in the scope of concrete and local researches over Izmir risky areas.
Abstract: Concrete strength evaluated from compression tests
on cores is affected by several factors causing differences from the
in-situ strength at the location from which the core specimen was
extracted. Among the factors, there is the damage possibly occurring
during the drilling phase that generally leads to underestimate the
actual in-situ strength. In order to quantify this effect, in this study
two wide datasets have been examined, including: (i) about 500 core
specimens extracted from Reinforced Concrete existing structures,
and (ii) about 600 cube specimens taken during the construction of
new structures in the framework of routine acceptance control. The
two experimental datasets have been compared in terms of
compression strength and specific weight values, accounting for the
main factors affecting a concrete property, that is type and amount of
cement, aggregates' grading, type and maximum size of aggregates,
water/cement ratio, placing and curing modality, concrete age. The
results show that the magnitude of the strength reduction due to
drilling damage is strongly affected by the actual properties of
concrete, being inversely proportional to its strength. Therefore, the
application of a single value of the correction coefficient, as generally
suggested in the technical literature and in structural codes, appears
inappropriate. A set of values of the drilling damage coefficient is
suggested as a function of the strength obtained from compressive
tests on cores.
Abstract: Sickness absence represents a major economic and
social issue. Analysis of sick leave data is a recurrent challenge to analysts because of the complexity of the data structure which is
often time dependent, highly skewed and clumped at zero. Ignoring these features to make statistical inference is likely to be inefficient
and misguided. Traditional approaches do not address these problems. In this study, we discuss model methodologies in terms of statistical techniques for addressing the difficulties with sick leave data. We also introduce and demonstrate a new method by performing a longitudinal assessment of long-term absenteeism using
a large registration dataset as a working example available from the Helsinki Health Study for municipal employees from Finland during the period of 1990-1999. We present a comparative study on model
selection and a critical analysis of the temporal trends, the occurrence
and degree of long-term sickness absences among municipal employees. The strengths of this working example include the large
sample size over a long follow-up period providing strong evidence in supporting of the new model. Our main goal is to propose a way to
select an appropriate model and to introduce a new methodology for analysing sickness absence data as well as to demonstrate model
applicability to complicated longitudinal data.
Abstract: In this paper, we apply and compare two generalized estimating equation approaches to the analysis of car breakdowns data in Mauritius. Number of breakdowns experienced by a machinery is a highly under-dispersed count random variable and its value can be attributed to the factors related to the mechanical input and output of that machinery. Analyzing such under-dispersed count observation as a function of the explanatory factors has been a challenging problem. In this paper, we aim at estimating the effects of various factors on the number of breakdowns experienced by a passenger car based on a study performed in Mauritius over a year. We remark that the number of passenger car breakdowns is highly under-dispersed. These data are therefore modelled and analyzed using Com-Poisson regression model. We use the two types of quasi-likelihood estimation approaches to estimate the parameters of the model: marginal and joint generalized quasi-likelihood estimating equation approaches. Under-dispersion parameter is estimated to be around 2.14 justifying the appropriateness of Com-Poisson distribution in modelling underdispersed count responses recorded in this study.
Abstract: In this paper, an estimation accuracy of multiple moving
talker tracking using a microphone array is improved. The tracking
can be achieved by the adaptive method in which two algorithms are integrated, namely, the PAST (Projection Approximation Subspace
Tracking) algorithm and the IPLS (Interior Point Least Square) algorithm. When either talker begins to speak again after a silent
period, an appropriate feasible region for an evaluation function of
the IPLS algorithm might not be set. Then, the tracking fails due to the incorrect updating. Therefore, if an increment of the number of
active talkers is detected, the feasible region must be reset. Then, a low cost realization is required for the high speed tracking and a high
accuracy realization is desired for the precise tracking. In this paper,
the directions roughly estimated using the delayed-sum-array method
are used for the resetting. Several results of experiments performed in
an actual room environment show the effectiveness of the proposed method.
Abstract: Eutrophication of surface water is one of the most
widespread environmental problems at present. Large number of
pilgrims and tourists visit sacred artificial tank known as “Brahma
Sarover” located at Kurukshetra, India to take holy dip and perform
religious ceremonies. The sources of pollutants include impurities in
feed water, mass bathing, religious offerings and windblown
particulate matter. Studies so far have focused mainly on assessing
water quality for bathing purpose by using physico-chemical and
bacteriological parameters. No effort has been made to assess nutrient
concentration and trophic status of the tank to take more appropriate
measures for improving water quality on long term basis. In the
present study, total nitrogen, total phosphorous and chlorophyll a
measurements have been done to assess the nutrient level and trophic
status of the tank. The results show presence of high concentration of
nutrients and Chlorophyll a indicating mesotrophic and eutrophic
state of the tank. Phosphorous has been observed as limiting nutrient
in the tank water.
Abstract: For over a decade, the Pulse Coupled Neural Network
(PCNN) based algorithms have been successfully used in image
interpretation applications including image segmentation. There are
several versions of the PCNN based image segmentation methods,
and the segmentation accuracy of all of them is very sensitive to the
values of the network parameters. Most methods treat PCNN
parameters like linking coefficient and primary firing threshold as
global parameters, and determine them by trial-and-error. The
automatic determination of appropriate values for linking coefficient,
and primary firing threshold is a challenging problem and deserves
further research. This paper presents a method for obtaining global as
well as local values for the linking coefficient and the primary firing
threshold for neurons directly from the image statistics. Extensive
simulation results show that the proposed approach achieves
excellent segmentation accuracy comparable to the best accuracy
obtainable by trial-and-error for a variety of images.
Abstract: The autonomous mobile robot was designed and implemented which was capable of navigating in the industrial environments and did a job of picking objects from variable height and delivering it to another location following a predefined trajectory. In developing country like Bangladesh industrial robotics is not very prevalent yet, due to the high installation cost. The objective of this project was to develop an autonomous mobile robot for industrial application using the available resources in the local market at lower manufacturing cost. The mechanical system of the robot was comprised of locomotion, gripping and elevation system. Grippers were designed to grip objects of a predefined shape. Cartesian elevation system was designed for vertical movement of the gripper. PIC18F452 microcontroller was the brain of the control system. The prototype autonomous robot was fabricated for relatively lower load than the industry and the performance was tested in a virtual industrial environment created within the laboratory to realize the effectiveness.
Abstract: Routing security is a major concerned in Wireless
Sensor Network since a large scale of unattended nodes is deployed
in ad hoc fashion with no possibility of a global addressing due to a
limitation of node-s memory and the node have to be self organizing
when the systems require a connection with the other nodes. It
becomes more challenging when the nodes have to act as the router
and tightly constrained on energy and computational capabilities
where any existing security mechanisms are not allowed to be fitted
directly. These reasons thus increasing vulnerabilities to the network
layer particularly and to the whole network, generally. In this paper,
a Dynamic Window Secured Implicit Geographic Forwarding
(DWSIGF) routing is presented where a dynamic time is used for
collection window to collect Clear to Send (CTS) control packet in
order to find an appropriate hoping node. The DWIGF is expected to
minimize a chance to select an attacker as the hoping node that
caused by a blackhole attack that happen because of the CTS rushing
attack, which promise a good network performance with high packet
delivery ratios.
Abstract: Free and open source software is gaining popularity at
an unprecedented rate of growth. Organizations despite some
concerns about the quality have been using them for various
purposes. One of the biggest concerns about free and open source
software is post release software defects and their fixing. Many
believe that there is no appropriate support available to fix the bugs.
On the contrary some believe that due to the active involvement of
internet user in online forums, they become a major source of
communicating the identification and fixing of defects in open source
software. The research model of this empirical investigation
establishes and studies the relationship between open source software
defects and online public forums. The results of this empirical study
provide evidence about the realities of software defects myths of
open source software. We used a dataset consist of 616 open source
software projects covering a broad range of categories to study the
research model of this investigation. The results of this investigation
show that online forums play a significant role identifying and fixing
the defects in open source software.
Abstract: the current study presents a modeling framework to determine the torsion strength of an induction hardened splined shaft by considering geometry and material aspects with the aim to optimize the static torsion strength by selection of spline geometry and hardness depth. Six different spline geometries and seven different hardness profiles including non-hardened and throughhardened shafts have been considered. The results reveal that the torque that causes initial yielding of the induction hardened splined shaft is strongly dependent on the hardness depth and the geometry of the spline teeth. Guidelines for selection of the appropriate hardness depth and spline geometry are given such that an optimum static torsion strength of the component can be achieved.
Abstract: Space Vector Modulation (SVM) is an optimum Pulse Width Modulation (PWM) technique for an inverter used in a variable frequency drive applications. It is computationally rigorous and hence limits the inverter switching frequency. Increase in switching frequency can be achieved using Neural Network (NN) based SVM, implemented on application specific chips. This paper proposes a neural network based SVM technique for a Voltage Source Inverter (VSI). The network proposed is independent of switching frequency. Different architectures are investigated keeping the total number of neurons constant. The performance of the inverter is compared for various switching frequencies for different architectures of NN based SVM. From the results obtained, the network with minimum resource and appropriate word length is identified. The bit precision required for this application is identified. The network with 8-bit precision is implemented in the IC XCV 400 and the results are presented. The performance of NN based general purpose SVM with higher bit precision is discussed.
Abstract: The running logs of a process hold valuable
information about its executed activity behavior and generated activity
logic structure. Theses informative logs can be extracted, analyzed and
utilized to improve the efficiencies of the process's execution and
conduction. One of the techniques used to accomplish the process
improvement is called as process mining. To mine similar processes is
such an improvement mission in process mining. Rather than directly
mining similar processes using a single comparing coefficient or a
complicate fitness function, this paper presents a simplified heuristic
process mining algorithm with two similarity comparisons that are
able to relatively conform the activity logic sequences (traces) of
mining processes with those of a normalized (regularized) one. The
relative process conformance is to find which of the mining processes
match the required activity sequences and relationships, further for
necessary and sufficient applications of the mined processes to process
improvements. One similarity presented is defined by the relationships
in terms of the number of similar activity sequences existing in
different processes; another similarity expresses the degree of the
similar (identical) activity sequences among the conforming processes.
Since these two similarities are with respect to certain typical behavior
(activity sequences) occurred in an entire process, the common
problems, such as the inappropriateness of an absolute comparison and
the incapability of an intrinsic information elicitation, which are often
appeared in other process conforming techniques, can be solved by the
relative process comparison presented in this paper. To demonstrate
the potentiality of the proposed algorithm, a numerical example is
illustrated.
Abstract: This paper is concerned with the existence of a linear copositive Lyapunov function(LCLF) for a special class of switched positive linear systems(SPLSs) composed of continuousand discrete-time subsystems. Firstly, by using system matrices, we construct a special kind of matrices in appropriate manner. Secondly, our results reveal that the Hurwitz stability of these matrices is equivalent to the existence of a common LCLF for arbitrary finite sets composed of continuous- and discrete-time positive linear timeinvariant( LTI) systems. Finally, a simple example is provided to illustrate the implication of our results.
Abstract: With the rapid popularization of internet services, it is apparent that the next generation terrestrial communication systems must be capable of supporting various applications like voice, video, and data. This paper presents the performance evaluation of turbo- coded mobile terrestrial communication systems, which are capable of providing high quality services for delay sensitive (voice or video) and delay tolerant (text transmission) multimedia applications in urban and suburban areas. Different types of multimedia information require different service qualities, which are generally expressed in terms of a maximum acceptable bit-error-rate (BER) and maximum tolerable latency. The breakthrough discovery of turbo codes allows us to significantly reduce the probability of bit errors with feasible latency. In a turbo-coded system, a trade-off between latency and BER results from the choice of convolutional component codes, interleaver type and size, decoding algorithm, and the number of decoding iterations. This trade-off can be exploited for multimedia applications by using optimal and suboptimal performance parameter amalgamations to achieve different service qualities. The results are therefore proposing an adaptive framework for turbo-coded wireless multimedia communications which incorporate a set of performance parameters that achieve an appropriate set of service qualities, depending on the application's requirements.
Abstract: This article proposes a voltage-mode
multifunction filter using differential voltage current
controllable current conveyor transconductance amplifier
(DV-CCCCTA). The features of the circuit are that: the
quality factor and pole frequency can be tuned independently
via the values of capacitors: the circuit description is very
simple, consisting of merely 1 DV-CCCCTA, and 2
capacitors. Without any component matching conditions, the
proposed circuit is very appropriate to further develop into
an integrated circuit. Additionally, each function response
can be selected by suitably selecting input signals with
digital method. The PSpice simulation results are depicted.
The given results agree well with the theoretical anticipation.
Abstract: An experimental and simulation flight test has been carried out to evaluate the longitudinal gliding characteristics of a lifting body with blunted half-cone geometry. The novelty here is the lifting body's pitch control mechanism, which consists of a pair of leading-edge rotating cylinders. Flight simulation uses aerodynamic data from computational fluid dynamics supported by wind-tunnel test. Flight test consists of releasing an aluminum lifting body model from a moving vehicle at the appropriate wind speed while measuring the lifting body's variation of altitude against time of flight. Results show that leading-edge rotating cylinder is able to give small amounts of improvement to the longitudinal stability and pitch control to the lifting body.