84 research outputs found
Distality of Attentional Focus and Its Role in Postural Balance Control
The role of attentional focusing in motor tasks has been highlighted frequently. The “internal–external” dimension has emerged, but also the spatial distance between body and attended location. In two experiments, an extended attentional focus paradigm was introduced to investigate distality effects of attentional foci on balance performance. First, the distality of the coordinates of the point of focus was varied between a proximal and distal position on an artificial tool attached to the body. Second, the distance of the displayed effect on the wall was varied between a 2.5 and 5 m condition. Subjects were instructed to focus on controlling either a proximal or distal spot on a tool attached to their head, represented by two laser pointers. Subsequently, they needed to visually track their own body-movement effect of one of the laser pointers at a wall while completing various single leg stance tasks. Center of pressure (COP) sway was analyzed using a linear method (classic sway variables) as well as a non-linear method (multiscale entropy). In addition, laser trajectories were videotaped and served as additional performance outcome measure. Experiment 1 revealed differences in balance performance under proximal compared to distal attentional focus conditions. Moreover, experiment 2 yielded differences in balance-related sway measures and laser data between the 2.5 and 5 m condition of the visually observable movement effect. In conclusion, varying the distality of the point of focus between proximal and distal impacted balance performance. However, this effect was not consistent across all balance tasks. Relevantly, the distality of the movement effect shows a significant effect on balance plus laser performance with advantages in more distal conditions. This research emphasizes the importance of the spatial distality of movement effects for human behavior
Optimized Energy Management of a Solar and Wind Equipped Student Residence with an Innovative Hybrid Energy Storage System
Grid-connected Energy Storage Systems (ESS) are vital for transforming the current energy sector. Lithium-Ion Battery (LIB) technology is presently the most popular form of ESS, especially because of its fast response capability, efficiency, and reducing market prices, but is not always preferred for long-term storage, due to its relatively shorter lifetime. A Redox Flow Battery (RFB) on the other hand has a higher lifetime and better long-term storage capability, but has a higher upfront cost and reduced round trip efficiency. A Hybrid ESS (HESS) consisting of LIB and RFB offers the advantages of both technologies, thus making the ESS more economical and flexible to use while also improving the cycle lifetime of individual ESS. Such a grid-connected HESS is planned and installed for a student residence at Bruchsal having 126 apartments for 150 students and equipped with 220 kWp photovoltaics and 10.5 kWp wind-power. Real-time high-resolution data of the residence’s electrical load and energy generation are collected and used to optimally control the HESS. Additionally, the RFB is also used as heat storage, which supports partial heating requirements of the residence.
In the present work, an Energy Management System (EMS) is deployed which not only controls this conglomerate but also optimizes its operations in real-time. The HESS is optimized two folds where it is operated with a fixed priority based strategy to improve the operational efficiency. Secondly using solar and load predictions, optimal charging schedules of the individual ESS are estimated. Based on the schedules the ESS are charged at its optimal charging points thus increasing charging efficiency and at the same time it avoids the ESS from staying at high SOC ranges for long time thus reducing ageing. Results based on real life operations based on the proposed methods are provided in this work
Generating realistic data for developing artificial neural network based SOC estimators for electric vehicles
Tracking the state of a lithium-ion battery in an electric vehicle (EV) is a challenging task. In order to tackle one aspect of this task, we choose a data-driven approach for estimating the State of Charge (SOC), which is one of the most import parameters. In this context, the quality of the provided data is of utmost importance. Usually, standardized driving profiles are used to generate current profiles which are then applied to battery cells during testing. However, these standardized driving profiles exhibit significant deviation from real-world conditions, which can considerably affect the learning and validation performance of data-driven approaches. In this paper, we first propose a test profile generator which generates realistic current profiles for EV battery testing. Second, to demonstrate the effect of the proposed test profiles a multilayer perceptron (MLP) based SOC estimator is presented. Finally, we compare the results to the standardized driving profiles
Generating realistic data for developing artificial neural network based SOC estimators for electric vehicles
Tracking the state of a lithium-ion battery in an electric vehicle (EV) is a challenging task. In order to tackle one aspect of this task, we choose a data-driven approach for estimating the State of Charge (SOC), which is one of the most import parameters. In this context, the quality of the provided data is of utmost importance. Usually, standardized driving profiles are used to generate current profiles which are then applied to battery cells during testing. However, these standardized driving profiles exhibit significant deviation from real-world conditions, which can considerably affect the learning and validation performance of data-driven approaches. In this paper, we first propose a test profile generator which generates realistic current profiles for EV battery testing. Second, to demonstrate the effect of the proposed test profiles a multilayer perceptron (MLP) based SOC estimator is presented. Finally, we compare the results to the standardized driving profiles
Effects of Realistic Driving Profiles on the Degradation of Lithium-Ion Batteries
In dieser Studie werden die Alterungseigenschaften von Lithium-Ionen-Batterien unter konventionellen Zyklustests und realistischen Fahrprofilprüfungen untersucht. Wir verwenden regelmäßige Kapazitätstests und elektrochemische Impedanzspektroskopie für eine umfassende Analyse des Gesundheitszustandes. Für diese Untersuchung haben wir handelsübliche, runde LFP-Zellen im Format 21700 verwendet. Die Ergebnisse zeigen einen stärkeren Kapazitätsverlust bei realistischen Fahrprofilen im Vergleich zu konventionellen Zyklen. Diese Diskrepanz deutet darauf hin, dass die Rekuperationsphasen ein Schlüsselfaktor für die beschleunigte Alterung von Lithium-Ionen-Batterien sind, die in Elektrofahrzeugen eingesetzt werden. Diese Forschung unterstreicht die Bedeutung realistischer Belastungsszenarien für die Bewertung der Batterielebensdauer und kann zur Entwicklung fortschrittlicherer Batteriemanagementsysteme in Elektrofahrzeugen beitragen
3,5,5,6,8,8-Hexamethyl-5,6,7,8-tetrahydro-2-naphthoic acid (AHTN–COOH)
The title compound, C17H24O2, is the product of a haloform reaction of 6-acetyl-1,1,2,4,4,7-hexamethyltetraline (AHTN). The compound is a racemic mixture with a disorder in its aliphatic ring [occupany ratio 0.683 (4):0.317 (4)] due to two possible half-chair forms. The carboxylic acid unit is slightly twisted out of coplanarity with the aromatic system [dihedral angle = 29.26 (6)°]. In the crystal, pairs of short classical intermolecular O—H⋯O hydrogen bonds link pairs of molecules around a center of symmetry
Multi-Jet Event Rates in Deep Inelastic Scattering and Determination of the Strong Coupling Constant
Jet event rates in deep inelastic ep scattering at HERA are investigated
applying the modified JADE jet algorithm. The analysis uses data taken with the
H1 detector in 1994 and 1995. The data are corrected for detector and
hadronization effects and then compared with perturbative QCD predictions using
next-to-leading order calculations. The strong coupling constant alpha_S(M_Z^2)
is determined evaluating the jet event rates. Values of alpha_S(Q^2) are
extracted in four different bins of the negative squared momentum
transfer~\qq in the range from 40 GeV2 to 4000 GeV2. A combined fit of the
renormalization group equation to these several alpha_S(Q^2) values results in
alpha_S(M_Z^2) = 0.117+-0.003(stat)+0.009-0.013(syst)+0.006(jet algorithm).Comment: 17 pages, 4 figures, 3 tables, this version to appear in Eur. Phys.
J.; it replaces first posted hep-ex/9807019 which had incorrect figure 4
Measurement of Leading Proton and Neutron Production in Deep Inelastic Scattering at HERA
Deep--inelastic scattering events with a leading baryon have been detected by
the H1 experiment at HERA using a forward proton spectrometer and a forward
neutron calorimeter. Semi--inclusive cross sections have been measured in the
kinematic region 2 <= Q^2 <= 50 GeV^2, 6.10^-5 <= x <= 6.10^-3 and baryon p_T
<= MeV, for events with a final state proton with energy 580 <= E' <= 740 GeV,
or a neutron with energy E' >= 160 GeV. The measurements are used to test
production models and factorization hypotheses. A Regge model of leading baryon
production which consists of pion, pomeron and secondary reggeon exchanges
gives an acceptable description of both semi-inclusive cross sections in the
region 0.7 <= E'/E_p <= 0.9, where E_p is the proton beam energy. The leading
neutron data are used to estimate for the first time the structure function of
the pion at small Bjorken--x.Comment: 30 pages, 9 figures, 2 tables, submitted to Eur. Phys.
An open-label pilot study of the effectiveness of adalimumab in patients with rheumatoid arthritis and previous infliximab treatment: relationship to reasons for failure and anti-infliximab antibody status
This prospective open-label pilot study evaluated the effectiveness and safety of adalimumab and the relationship to antibodies against infliximab (IFX) in adult patients with active rheumatoid arthritis (RA) who had been treated previously with IFX and experienced treatment failure owing to lack or loss of response or intolerance. Patients self-administered adalimumab 40 mg subcutaneously every other week for 16 weeks, followed by maintenance therapy for up to Week 56. Measures of effectiveness included American College of Rheumatology (ACR) and European League Against Rheumatism (EULAR) response criteria, 28-joint Disease Activity Score, and the Health Assessment Questionnaire Disability Index. Serum IFX concentrations, human antichimeric antibody against IFX (HACA), adalimumab serum concentrations, antiadalimumab antibody, and safety also were assessed. Of the 41 enrolled patients, 37 completed 16 weeks and 30 completed 56 weeks of treatment. Patients experienced clinically meaningful improvements in all measures of RA activity, with greater response rates observed for patients who had experienced loss of initial response to or intolerance of IFX. At Week 16, 46% of patients achieved an ACR20 and 28% achieved an ACR50; 61% achieved an at least moderate and 17% achieved a good EULAR response. Clinical benefit was maintained through Week 56 in all effectiveness parameters. Baseline HACA status did not significantly impact effectiveness. No new safety signals were observed; neither former IFX intolerance status nor baseline HACA status had a clinically relevant impact on adverse event frequency or severity. Adalimumab was effective and well-tolerated in patients with RA who previously failed IFX therapy, irrespective of reason for discontinuation and of HACA status
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