Human-like behavior of robot arms: general considerations and the handwriting task—Part II: the robot arm in handwriting

This paper (Part II) investigates the motion of a redundant anthropomorphic arm during the writing task. Two approaches are applied. The first is based on the concept of distributed positioning which is suitable to model the “writing” task before the occurrence of fatigue symptoms. The second approach uses the concept of “virtual fatigue” (VF) which is a variable that dynamically behaves in a way analogous to the biological fatigue. VF enables the arm to reconfigure itself and take postures appropriate for the current level of fatigue. The study includes the analysis of legibility and inclination of handwriting, and a set of simulation results that show most practical aspects of robot human-like performance.     

Performance Analysis of Interference-Limited Mobile-to-Mobile κ–μ Fading Channel

Wireless Personal Communications - In this paper, a wireless cooperative network, with two sections, operating over multipath mobile-to-mobile interference-limited fading channel is considered. The...     

Development of Grid e-Infrastructure in South-Eastern Europe

Over the period of six years and three phases, the SEE-GRID programme has established a strong regional human network in the area of distributed scientific computing and has set up a powerful regional Grid infrastructure. It attracted a number of user communities and applications from diverse fields from countries throughout the South-Eastern Europe. From the infrastructure point view, the first project phase has established a pilot Grid infrastructure with more than 20 resource centers in 11 countries. During the subsequent two phases of the project, the infrastructure has grown to currently 55 resource centers with more than 6,600 CPUs and 750 TBs of disk storage, distributed in 16 participating countries. Inclusion of new resource centers to the existing infrastructure, as well as a support to new user communities, has demanded setup of regionally distributed core services, development of new monitoring and operational tools, and close collaboration of all partner institution in managing such a complex infrastructure. In this paper we give an overview of the development and current status of SEE-GRID regional infrastructure and describe its transition to the NGI-based Grid model in EGI, with the strong SEE regional collaboration.     

Second order statistics of the SC receiver over Rician fading channels in the presence of multiple Nakagami‐m interferers

In this paper, a numerical approach to the performance analysis of a signal‐to‐interference‐based selection combining receiver, operating over a Rician multipath‐fading environment, in the presence of multiple Nakagami‐m co‐channel interferers is provided. Closed form expressions are obtained for the first‐order and second‐order statistical measures, that is, the probability density function, cumulative distribution function, and average level‐crossing rate of the received signal. Further, the aforementioned results are used for an efficient evaluation of other performance measures, such are outage probability and average fade duration. A graphical representation of the obtained numerical results is also provided in order to present and discuss the influence of transmission parameters on the studied performance measures. Copyright © 2015 John Wiley & Sons, Ltd.     

Performance analysis of selection diversity over exponentially correlated α– µ fading environment

An approach to the performance analysis of multibranch selection combiner (SC) receiver operating over fading channels is presented. High level of generality for the proposed analysis is achieved by considering correlated α– µ fading environment. The effect of correlation is studied by assuming exponential correlation model of the signals in each diversity branch. The whole analysis is observed in the interference‐limited fading environments (SIR‐based diversity system is assumed). The important performance measures are considered. Closed form of formulae for the output SIR's probability density function and cumulative distribution function are derived. In order to check the accuracy of the complete proposed formulation, some numerical results are presented. Copyright © 2011 John Wiley & Sons, Ltd.     

Performance analysis of system with L‐branch selection combining over correlated Weibull fading channels in the presence of cochannel interference

In this paper, the performance of L‐branch selection combining receiver over correlated Weibull fading channels in the presence of correlated Weibull‐distributed cochannel interference is analyzed. Closed‐form expressions for probability density function and cumulative distribution function of the signal‐to‐interference ratio at the output of the selection combining receiver present main contribution of this paper. Numerical results are also presented to show the effects of various parameters as the fading severity, correlation and number of branches on outage probability. Copyright © 2009 John Wiley & Sons, Ltd.     

The analysis of simultaneous clove/oregano and clove/thyme supercritical extraction

The goal of present work was to investigate and explain kinetics and mass transfer phenomena occurring during the SFE from the mixture of two plants with different initial composition. The extractions from pure clove, oregano and thyme as well as from clove/oregano (C/O) and clove/thyme (C/T) mixtures with various initial compositions of plant material were carried out using supercritical CO₂ at 10 MPa and 40 °C. The results indicated that presence of light compounds in supercritical CO₂ originated from the oregano leaves or thyme at the beginning of extraction process increases the extraction rate of compounds from clove bud. Only small added amounts of oregano or thyme to clove bud (C/O - 90:10%, w/w; or C/T - 84:16%, w/w) in the starting plant mixture had the same effect resulted in the similar and the highest increase of the extraction rate and had negligible influence on total extraction yield compared to extract isolated from pure clove. Different mathematical models were used for simulation of experimental data which showed that the highest increase of the solubility of extractable compounds in supercritical CO₂ as well as the highest mass transfer rate in the solid phase during extractions existed during extraction from C/O (90:10, w/w) and C/T (84:16, w/w) mixtures. Decrease of SC CO₂ consumption or shorter time of extraction necessary for achieving desired extract yield in the case of SFE of the clove buds could be important for industrial-scale application.     

Effect of noisy carrier reference signal and interference on performance of MSK receiver

This paper considers the coherent detection of minimum shift keying signal and a degradation in error rate performance from ideal due to an interference and a phase discrepancy between the carrier of the received signal and the carrier of the receiver. The error rate is calculated for the simple receiver model with integrate‐and‐dump circuits. The reference carrier signal unsteadiness is presented by the probability density function of the first order non‐linear PLL phase error, while the uncertainty due to an interference is involved in the system model with a random phase of cosine signal that accompanied the useful signal. Copyright © 2004 John Wiley & Sons, Ltd.     

Evaluation of rotary dehumidifier performance with and without heated purge

In this paper we evaluate the potential benefits from separating process air stream at the exit of rotary dehumidifier into two streams. One air stream, hot and humid, is called purge air stream and other is remaining process air stream. The remaining process air stream has a lower temperature and humidity ratio as result of separation of initial hot process air stream. It is found that as the purge angle increases the exit humidity ratio of remaining process air stream decreases up to a point where it reaches a minimum. The purge angle for which this occurs is named “effective purge angle”. The effective purge angles for different splits between adsorption and desorption side of the rotary dehumidifier, various regeneration temperatures, non-dimensional lengths and their corresponding optimum non-dimensional times are determined. An existing finite-difference model, developed by the authors of this paper, for simulation of desiccant wheel performance is extended to account for the separation of the process air stream at the exit of rotary dehumidifier and later mixing of purge air stream and outside air to form the regeneration air stream. The performance of desiccant wheel with heated “effective purge angle” is evaluated and compared with performance of the same wheel without purge angle at all. It is found, for all cases considered in this study, that having heated “effective purge angle” has overall positive effect on the performance of the rotary dehumidifier.     

C.P.S.K. receiver performances in presence of carrier-frequency offset

Error probability in a binary c.p.s.k. receiver with a carrier-frequency offset is studied. The error probability has been evaluated as a function of the p.l.l. bandwidth. The optimum value of the p.l.l. bandwidth for a given frequency offset is determined with and without the slow Rice fading.