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1.
Vafeiadis Thanasis Bora-Senta Efthimia Kugiumtzis Dimitris 《Simulation Modelling Practice and Theory》2011,19(5):1384-1398
We propose a method to detect the onset of linear trend in a time series and estimate the change point T from the profile of a linear trend test statistic, computed on consecutive overlapping time windows along the time series. We compare our method to two standard methods for trend change detection and evaluate them with Monte Carlo simulations for different time series lengths, autocorrelation strengths, trend slopes and distribution of residuals. The proposed method turns out to estimate T better for small and correlated time series. The methods were also applied to global temperature records suggesting different turning points. 相似文献
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Mantzourani ED Platts JA Brancale A Mavromoustakos TM Tselios TV 《Journal of molecular graphics & modelling》2007,26(2):471-481
This work reports molecular dynamics studies at the receptor level of the immunodominant myelin basic protein (MBP) epitope 87-99 implicated in multiple sclerosis, and its antagonists altered peptide ligands (APLs), namely [Arg91, Ala96] MBP87-99 and [Ala91,96] MBP87-99. The interaction of each peptide ligand with the receptor human leukocyte antigen HLA-DR2b was studied, starting from X-ray structure with pdb code: 1ymm. This is the first such study of APL-HLA-DR2b complexes, and hence the first attempt to gain a better understanding of the molecular recognition mechanisms that underlie TCR antagonism by these APLs. The amino acids His88 and Phe89 serve as T-cell receptor (TCR) anchors in the formation of the trimolecular complex TCR-peptide-HLA-DR2b, where the TCR binds in a diagonal, off-centered mode to the peptide-HLA complex. The present findings indicate that these two amino acids have a different orientation in the APLs [Arg91, Ala96] MBP87-99 and [Ala91,96] MBP87-99: His88 and Phe89 remain buried in HLA grooves and are not available for interaction with the TCR. We propose that this different topology could provide a possible mechanism of action for TCR antagonism. 相似文献
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Efthimia Aivaloglou Stefanos Gritzalis Charalabos Skianis 《Telecommunication Systems》2007,35(3-4):207-213
Wireless sensor networks highly depend on the distributed cooperation among network nodes. Trust establishment frameworks provide the means for representing, evaluating, maintaining and distributing trust within the network, and serve as the basis for higher level security services. In this paper, we propose a trust establishment framework targeted sensor networks that can uniformly support the needs of nodes with highly diverse network roles and capabilities, by exploiting the pre-deployment knowledge on the network topology and the information flows. The framework allows for flexibility by combining aspects from alternative approaches on trust establishment on common evaluation metrics, and enables controlled trust evolution based on the network pre-configuration. 相似文献
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Mark Becker Efthimia Kefalea Eric Maël Christoph Von Der Malsburg Mike Pagel Jochen Triesch Jan C. Vorbrüggen Rolf P. Würtz Stefan Zadel 《Autonomous Robots》1999,6(2):203-221
We have designed a research platform for a perceptually guided robot, which also serves as a demonstrator for a coming generation of service robots. In order to operate semi-autonomously, these require a capacity for learning about their environment and tasks, and will have to interact directly with their human operators. Thus, they must be supplied with skills in the fields of human-computer interaction, vision, and manipulation. GripSee is able to autonomously grasp and manipulate objects on a table in front of it. The choice of object, the grip to be used, and the desired final position are indicated by an operator using hand gestures. Grasping is performed similar to human behavior: the object is first fixated, then its form, size, orientation, and position are determined, a grip is planned, and finally the object is grasped, moved to a new position, and released. As a final example for useful autonomous behavior we show how the calibration of the robot's image-to-world coordinate transform can be learned from experience, thus making detailed and unstable calibration of this important subsystem superfluous. The integration concepts developed at our institute have led to a flexible library of robot skills that can be easily recombined for a variety of useful behaviors. 相似文献
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Evaluation of shelf life was made of cured, cooked, sliced turkey breast fillets and a type of cooked pork sausage called 'piroski', stored in vacuum and in six different modified atmospheres (MA) at +4 and +10?°C. Total viable count, lactic acid bacteria, pH changes, colour attributes and the presence of pathogenic bacteria (listeriae, staphylococci) were monitored during the storage. The results of the study showed that the average shelf life for both products was 2 and 1 week at 4 and 10?°C, respectively. By the end of these periods, the bacterial population consisting of only lactic acid bacteria reached 10(8) cfu g(-1). Macroscopical (colour, drip loss and slime) and organoleptical changes (sour odours) were not related to pH and observed already at pH values >5.5. It is concluded that the use of MA packaging in these tests did not extend and not reduce the product shelf life in comparison to vacuum packaging. 相似文献
8.
Boukouvala E Antonopoulou E Favre-Krey L Diez A Bautista JM Leaver MJ Tocher DR Krey G 《Lipids》2004,39(11):1085-1092
Peroxisome proliferator-activated receptors (PPAR) are nuclear hormone receptors that control the expression of genes involved
in lipid homeostasis in mammals. We searched for PPAR in sea bass, a marine fish of particular interest to aquaculture, after
hypothesizing that the physiological and molecular processes that regulate lipid metabolism in fish are similar to those in
mammals. Here, we report the identification of complementary DNA and corresponding genomic sequences that encode three distinct
PPAR from sea bass. The sea bass PPAR are the structural homologs of the mammalian PPARα, β/δ and γ isotypes. As revealed
by RNase protection, the tissue expression profile of the fish PPAR appears to be very similar to that of the mammalian PPAR
homologs. Thus, PPARα is mainly expressed in the liver, PPARγ in adipose tissue, and PPARβ in all tissues tested, with its
highest levels in the liver, where it is also the dominant isotype expressed. Like mammalian PPAR, the sea bass isotypes recognize
and bind to PPAR response elements of both mammalian and piscine origin, as heterodimers with the 9-cis retinoic acid receptor. Through the coactivator-dependent receptor ligand assay, we also demonstrated that natural FA and
synthetic hypolipidemic compounds can act as ligands of the sea bass PPARα and β isotypes. This suggests that the sea bass
PPAR act through similar mechanisms and perform the same critical lipid metabolism functions as mammalian PPAR. 相似文献
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Mining affective needs of automotive industry customers for building a mass-customization recommender system 总被引:1,自引:0,他引:1
Efthimia Mavridou Dionisis D. Kehagias Dimitrios Tzovaras George Hassapis 《Journal of Intelligent Manufacturing》2013,24(2):251-265
Mass customization systems aim to receive customer preferences in order to facilitate personalization of products and services. Current online configuration systems are unable to efficiently identify real customer affective needs because they offer an excess variety of products that usually confuse customers. On the other hand, mining affective customer needs may result in recommender systems, which can enhance existing configuration systems by recommending initial configurations according to customer affective needs. This paper introduces a mass customization recommender system that exploits data mining techniques on automotive industry customer data aiming at revealing associations between user affective needs and the design parameters of automotive products. One key novelty of the presented approach is that it deploys the Citarasa engineering, a methodology that focuses on the provision of the appropriate characterizations on customer data in order to associate them with customer affective needs. Based on the application of classification techniques we build a recommendation engine, which is evaluated in terms of user satisfaction, tool’s effectiveness, usefulness and reliability among other parameters. 相似文献
10.
Efthimia P. Mourvati Ploumis S. Passadakis Elias D. Thodis Stelios A. Panagoutsos Omiros G. Galtsidopoulos Vassilis A. Vargemezis 《Hemodialysis international. International Symposium on Home Hemodialysis》2001,5(1):37-41
Uremic polyneuropathy is one of the major complications of long‐term end‐stage renal disease. In the present study, we performed an electrophysiologic evaluation in 17 patients having a mean age of 49 ± 11 years. The patients were divided into two groups according to dialysis method. Group A included 9 patients who were undergoing conventional hemodialysis (mean age, 44.2 ± 12.5 years; mean duration on dialysis, 21.7 ± 4.3 months); group B included 8 patients undergoing hemofiltration (mean age, 55.2 ± 5.2 years; mean duration on treatment, 27 ± 7.6 months). Measurements of the distal latency time of the sensory fibers (median, ulnar, and sural nerves), and measurements of the distal latency time and peripheral conduction velocity of the motor fibers (median and peroneal nerves) were performed. In addition, we recorded somatosensory evoked potentials after peripheral stimulation of the median and peroneal nerves. The electrophysiologic evaluations were repeated two times at intervals of 12 months. In group A, a statistically significant worsening of motor and sensory conductance in the upper and lower limbs was observed; in group B, a statistically significant improvement was found. These findings suggest that hemofiltration has a more beneficial effect on motor and sensory conductivity than does conventional hemodialysis. 相似文献