The homology of path spaces and Floer homology with conormal boundary conditions

We define the Floer complex for Hamiltonian orbits on the cotangent bundle of a compact manifold satisfying non-local conormal boundary conditions. We prove that the homology of this chain complex is isomorphic to the singular homology of the natural path space associated to the boundary conditions.Comment: 25 pages, final versio

Evaluation of the efficiency and resulting electrical and economic losses of photovoltaic home storage systems

The increase in electricity prices along with a decrease in the price of storage systems has led to a rapid expansion of the photovoltaic (PV) home storage system market, particularly in Germany. In order to be economically viable, PV home storage systems must fulfil certain performance criteria. The overall performance and achievable self-sufficiency ratio of a PV battery home storage system depends on (i) the efficiencies of the system components, (ii) the standby consumption, (iii) the reaction time of the home storage system as well as (iv) the intelligence of the overall system control software. So far, PV home storage system still show very big differences in their performance. However, poor system performance can result in the system being no longer economic viable. Up to now, there have been only a few studies that deal with the evaluation and systematic comparison of the performance of PV home storage systems. For this paper the performance of 12 commercially available PV-battery systems has been analysed with a focus on the overall system efficiency. The efficiency of the systems is mainly influenced by the battery efficiency, power conversion efficiency and standby consumption of the different system components. Therefore, a testing and evaluation method has been developed. In this work the method as well as the results of the systems are presented. A detailed study of the influence of the effects of the individual losses on both total energy and monetary losses was carried out. It is shown that power conversion has the greatest influence on energy and monetary losses. For the systems under evaluation the monetary losses per year due to battery efficiency losses range between 2 €/a and 40 €/a. Monetary losses due to conversion losses range between 33 €/a and 137 €/a and due to standby consumption between 1 €/a and 46 €/a. The individual losses can be summed up to give a total loss, which lies between 44 €/a and 174 €/a

Driving and Speaking: Revelations by the Head-Mounted Detection Response Task

The cognitive workload of speech-related activity needs to be examined in an economic and simple way. This is especially important as invehicle technology is becoming more cognitive with, for example, the use of speech-interaction and industry will need a way to keep pace with new technologies. One proposed way to measure cognitive workload is the detection response task (DRT) method. In this study, the DRT was used to assess different speech-related cognitive tasks. Three conversation tasks and the n-back task were performed together with a simulated driving task and a head-mounted DRT (HDRT). The aim was to evaluate the conversation and n-back tasks with the HDRT and to quantify the respective cognitive workload. Results show an increase in HDRT reaction times when additional cognitive tasks are performed relative to baseline measurements. In line with other research methods, the HDRT provided a reliable measurement of additional workload

Comparing eye movements recorded by search coil and infrared eye tracking

Objective: The performance of a new video-based infrared eye tracker (IR) was compared to the magnetic search coil technique (SC). Since the IR offers interesting possibilities as a diagnostic tool in neuro-ophthalmology, it was investigated whether the new device has overcome shortcomings that were reported from former IR systems. Methods: Horizontal saccades were recorded using the IR and the SC. The IR allowed eye movement recordings at different sampling rates ranging from 250Hz to 1000Hz while the SC recorded at 1000Hz. Results/Conclusions: The results show that the IR and the SC were in good agreement and produced similar results. In contrast to other studies, the influence of the sampling rate of the IR was small. The saccade main-sequences did not show significant differences. The latency times observed for both systems were mainly in the short-latency rang

Flight Controls of Otto Lilienthal's Experimental Monoplane from 1895

In 1889, Otto Lilienthal published his book Birdflight as the Basis of Aviation, containing the first lift-versus-drag data of cambered wings and other important information required for human flight. In 1895, Lilienthal demonstrated his 12th aircraft design, a monoplane with a wing area of over 20 m2. Because of its wingspan of almost 9 m and wing chord length of 3 m, Lilienthal’s largest monoplane can only be used in light winds. Lilienthal applied for a patent on the same day. The patent claim was submitted for the front wing (Vorflügel), a leading-edge flap used in a glider for this purpose for the first time. Because of the size of the apparatus, three profile rails were slid onto each wing instead of the usual two