Gait Verification using Knee Acceleration Signals

A novel gait recognition method for biometric applications is proposed. The approach has the following distinct features. First, gait patterns are determined via knee acceleration signals, circumventing difficulties associated with conventional vision-based gait recognition methods. Second, an automatic procedure to extract gait features from acceleration signals is developed that employs a multiple-template classification method. Consequently, the proposed approach can adjust the sensitivity and specificity of the gait recognition system with great flexibility. Experimental results from 35 subjects demonstrate the potential of the approach for successful recognition. By setting sensitivity to be 0.95 and 0.90, the resulting specificity ranges from 1 to 0.783 and 1.00 to 0.945, respectively

Allocation of tie-line costs in power exchange scheduling using amulti-agent approach

After deregulations in power industries, the original boundary lines have been removed and how to support optimal cross-border electricity trade planning has become an important issue. Decentralization, or all market participants have the rights to participate in decision making, is one of the directions. In this paper a decentralized structure is suggested to solve the problem using multi-agent technology. In this structure the information centralization is prevented and each market participant behaves rationally based on local information. Although the market participants make decisions to protect its own benefits, the minimum production and transmission cost of the whole system can be finally reached. This structure is based on the method proposed in another paper by the authors and implemented on computer via a multi-agent system using Java programming language. A demonstration on a 5-area test system shows that the suggested new approach is effective and promising.published_or_final_versio

A decentralized approach for optimal wholesale cross-border trade planning using multi-agent technology

Over the past decade, power industry has been undergoing deregulations to introduce competitions among market participants. Once centralized decision making must now adapt to the new market structure. The optimal cross-border electricity trade planning is an important issue in interconnected power systems under transmission open access. In this paper a decentralized approach is suggested to solve the problem using multi-agent technology. In the new approach rational market participants make decisions based on their own benefits, in the meantime the minimum production and transmission cost of the whole system can be reached without a central coordination except necessary information exchange through media like the Internet. A relevant lemma has been proven. The approach is implemented via a multi-agent system using Java programming language. Computer tests on a 5-area test system show that the suggested new approach is effective and promising.published_or_final_versio

A multi-agent based negotiation support system for cost allocation of cross-border transmission

Regulation and protection have been the major issues to prevent the consumers from enjoying good quality of service (QoS) at reasonable prices, for example, electricity and long distance call service. Deregulation in such industries started in early 1970s and have achieved significant results in, for example, telecommunication industry. The deregulation in telecommunication was mainly focused on reducing the market power to add more competition to reduce the price and to improve QoS. Similarly, the power industry in several countries also underwent regulation. The power industry used to be protected and regulated. Consumers were forced to buy electricity from particular suppliers and suffered high prices and low QoS. After deregulation, the original boundary lines have been removed and consumers have more alternatives. How to support optimal planning of cross-border electricity trade has become an important issue since then. Decentralization, or participants have the rights to participate in decision making, is one of the directions of deregulation. In this paper a decentralized structure is suggested to solve the problem by using multi-agent technology to create autonomy for each participant. In such structure the centralization of information transmission or decision making is prevented. Each participant behaves rationally to search for best benefit or payoff through the information she or he owns or through information exchange with other participants. Although all the market participants make decisions to protect their own benefits, the optimal solution (total costs) of the whole system can be achieved finally. This structure is based on the method proposed in [5] and implementation, which a multiagent system called Multi-Agent System for Cross-Border Trade (MASCBT), was done by using Java programming language. A demonstration on a 5-area test system shows that the suggested new approach is effective and promising.published_or_final_versio

Marginally Trapped Surfaces in the Nonsymmetric Gravitational Theory

We consider a simple, physical approach to the problem of marginally trapped surfaces in the Nonsymmetric Gravitational Theory (NGT). We apply this approach to a particular spherically symmetric, Wyman sector gravitational field, consisting of a pulse in the antisymmetric field variable. We demonstrate that marginally trapped surfaces do exist for this choice of initial data.Comment: REVTeX 3.0 with epsf macros and AMS symbols, 3 pages, 1 figur

Large strain actuation in barium titanate single crystals under stress and electric field

Large strain actuation in barium titanate (BaTiO3) single crystals subjected to combined uniaxial stress and electric field is examined. A maximum strain of about 0.45% is measured under a combined loading of 2.7 MPa compressive stress and ±1.25 MVm-1 cyclic electric field. Above 2.7 MPa, the crystal does not cycle fully between the in-plane and out-of-plane polarized states due to large compressive stress, and consequently, a considerable reduction in actuation strain is apparent. The hysteresis evolution of the crystal under combined electromechanical loading reveals incomplete switching characteristics and a considerable disproportion of slope gradients at zero electric field for the measured polarization and strain hysteresis curves. A likely cause for the disproportion of slope gradients is the cooperative operation of multiple 90° switching systems by which “polarization-free” strain changes are induced

Long-term X-ray Variability of Ultraluminous X-ray Sources

Long-term X-ray modulations on timescales from tens to hundreds of days have been widely studied for X-ray binaries located in the Milky Way and the Magellanic Clouds. For other nearby galaxies, only the most luminous X-ray sources can be monitored with dedicated observations. We here present the first systematic study of long-term X-ray variability of four ultraluminous X-ray sources (ESO 243-49 HLX-1, Holmberg IX X-1, M81 X-6, and NGC 5408 X-1) monitored with Swift. By using various dynamic techniques to analyse their light curves, we find several interesting low-frequency quasi-periodicities. Although the periodic signals may not represent any stable orbital modulations, these detections reveal that such long-term regular patterns may be related to superorbital periods and structure of the accretion discs. In particular, we show that the outburst recurrence time of ESO 243-49 HLX-1 varies over time and suggest that it may not be the orbital period. Instead, it may be due to some kinds of precession, and the true binary period is expected to be much shorter.Comment: 15 pages, 8 figures; accepted for publication in MNRA

Discovery of X-ray pulsations from "next Geminga" - PSR J1836+5925

We report the X-ray pulsation of ~173.3 ms for the "next Geminga", PSR J1836+5925, with recent XMM-Newton investigations. The X-ray periodicity is consistent wtih the gamma-ray ephemeris at the same epoch. The X-ray folded light curve has a sinusoidal structure which is different from the double-peaked gamma-ray pulse profile. We have also analysed the X-ray phase-averaged spectra which shows the X-ray emission from PSR J1836+5925 is thermal dominant. This suggests the X-ray pulsation mainly originates from the modulated hot spot on the stellar surface.Comment: 7 pages, 3 figures, 1 table, accepted for publication in ApJ Lette

Stability of Horava-Lifshitz Black Holes in the Context of AdS/CFT

The anti--de Sitter/conformal field theory (AdS/CFT) correspondence is a powerful tool that promises to provide new insights toward a full understanding of field theories under extreme conditions, including but not limited to quark-gluon plasma, Fermi liquid and superconductor. In many such applications, one typically models the field theory with asymptotically AdS black holes. These black holes are subjected to stringy effects that might render them unstable. Ho\v{r}ava-Lifshitz gravity, in which space and time undergo different transformations, has attracted attentions due to its power-counting renormalizability. In terms of AdS/CFT correspondence, Ho\v{r}ava-Lifshitz black holes might be useful to model holographic superconductors with Lifshitz scaling symmetry. It is thus interesting to study the stringy stability of Ho\v{r}ava-Lifshitz black holes in the context of AdS/CFT. We find that uncharged topological black holes in $\lambda=1$ Ho\v{r}ava-Lifshitz theory are nonperturbatively stable, unlike their counterparts in Einstein gravity, with the possible exceptions of negatively curved black holes with detailed balance parameter $\epsilon$ close to unity. Sufficiently charged flat black holes for $\epsilon$ close to unity, and sufficiently charged positively curved black holes with $\epsilon$ close to zero, are also unstable. The implication to the Ho\v{r}ava-Lifshitz holographic superconductor is discussed.Comment: 15 pages, 6 figures. Updated version accepted by Phys. Rev. D, with corrections to various misprints. References update

Radiotelemetry monitored measurements of the effects of medetomidine-midazolam-fentanyl, isoflurane or ketamine-xylazine anaesthesia on physiological parameters in guinea pigs

Anaesthesia in guinea pigs (GPs) has often been described as difficult and risky. Therefore, the included publications invested the effect of the mostly used anaesthesias MMF (medetomidine-midazolam-fentanyl), isoflurane (Iso) and ketamine-xylazine (KX) on physiological parameters in GPs. Throughout the anaesthesia, the GPs’ cardiovascular parameters were monitored, using abdominally implanted radiotelemetry devices to obtain optimal data quality. The surgical approach used for the implantation of the radiotelemetry transmitter is presented in detail in the first publication. For surgery, the GPs were anaesthetised with MMF (medetomi-dine-midazolam-fentanyl) and they were antagonised with AFN (atipamezole-flumazenil-nalxone) at the end of the surgery. For pain medication, the GPs were started on meloxicam (0.4 mg/kg) and metamizole (80 mg/kg) 30 min before the surgery. Metamizole was continued for 24 h after surgery and meloxicam for 2 more days. During the implantation, they were additionally covered with the fentanyl component in MMF. Prior to the surgery, enrofloxacin (10 mg/kg) was applied for antibiotic coverage which was continued for 2 more days. Using the implanted system, arterial blood pressure (BP), heart rate (HR) and core body temperature (BT) were measured throughout the first 24 h after the end of the implantation. The implantation approach led to the highest long-term survival rate reported to date, with 13 of 16 GPs (81 %) surviving. The GPs lost body weight (BW) until 2 d after surgery (-11.9 %, -53.6 g) but steadily increased their weight thereafter. The GPs had returned to physiological values in BP and BT at 8 h after abdominal surgery and at 24 h regarding HR. As GPs are stress-prone, recommendations for stress reduced handling were given for before, during and after the implantation. The findings on the effects of the implantation can be used as a model for other abdominal operations in the GP. The second publication described the investigation of the effects of one-time Iso, MMF and KX anaesthesia on the physiological parameters using the 13 implanted GPs. Each animal was anesthetised once with MMF, Iso and KX at an interval of 7 d. The entire anaesthesia pass was recorded radiotelemetrically and supplemented by manual measurements of respiratory rate (ReR), reflexes and blood glucose (BG). One anaesthesia pass included 120 min acclimatization time, of which the last 15 min were averaged as individual baseline values. The GPs were then premedicated; with Iso with atropine and with MMF and KX with sodium chloride as placebo. Ten minutes later, anaesthesia was initiated, for Iso anaesthesia using a pre-filled whole body chamber and for MMF and KX with intramuscular injections into the hind limbs. Anaesthesia was discontinued after 40 min by Iso supply stop, AFN antagonisation for MMF or partial antagonisation with atipamezole for KX anaesthesia. The MAP, HR, BT were measured continuously until at least 240 min after anaesthesia induction. Respiratory rate (ReR) was measured until at least 55 min and reflexes were tested until the GPs showed a positive righting reflex again. BG values were measured at 7.5, 20 and 40 min during anaesthesia. With Iso use, all GPs reached a surgical tolerance, 11 did so with MMF anaesthesia and only 7 reached an operable state with KX. The induction, non-surgical tolerance and surgical tolerance phase durations did not differ considerably between the 3 anaesthetics. Following MMF and Iso there were short wake-up times (7.6 & 12.2 min), whereas it required 59.7 min until the GPs regained their RR after KX. MMF anaesthesia led to a marked transient MAP decrease after antagonisation, otherwise the MAP and the HR were only mildly altered. Iso exposure led to a marked hypotension during anaesthesia maintenance (approx. 20 mmHg) and the HR was only mildly increased at the beginning of the anaesthesia. KX caused mild deviations from the normal physiology for MAP and HR during maintenance. However, after partial antagonisation, the MAP dropped and the GPs recovered only slowly. The HR was also reduced and increased only gradually during the wake-up following KX anaesthesia. All anaesthetics induced hypothermia, but the animals lost the most BT with Iso anaesthesia. Immediately after the end of the MMF and Iso anaesthesia, the GPs were able to quickly lift their BT back to the starting level through shivering. After KX anaesthesia only 3 of the 7 GPs had returned to 38.8°C after 5 h, the other 4 still had not reached pre-anaesthetic BT values after 8 h. Respiratory depression occurred with all 3 anaesthetics, with KX leading to a moderate (-52%) and Iso to a severe (-71%) hypoventilation. There was also a strong irritation of the mucous membranes of the respiratory tract through the respiratory gas. Subsequent mucosal secretion could only be alleviated by atropine pre-medication in the short term. BG increases were observed during KX (moderate) and strongly during MMF anaesthesia. The reflex responses varied considerably between the anaesthetics. They were strong and quick during MMF anaesthesia and slightly less so with KX use. Iso exposure led to weak and slow reflex responses. Overall, MMF was determined to be the anaesthesia of choice; Iso can only be advised for short and non-painful procedures and we advise against the use of KX anaesthesia in GPs. After investigating the effects of single anaesthesia with Iso, MMF and KX, the third paper de-scribed the impact of repeated MMF and Iso anaesthesia. KX was not tested for anaesthesia repetition because of its highly unfavourable effects in the recovery phase. Twelve instrumented MS were anesthetised in 2 anaesthesia sets, 6 times over 3 weeks with either only Iso or only MMF. Each anaesthesia repetition was performed as described for the single anaesthesia. All GPs reached a surgical tolerance and this could be maintained for the desired 40 min. Overall, the anaesthetic profiles of MMF and Iso did not change greatly with anaesthesia repetition. During Iso exposure, the repeated atropine premedication caused the HR to increase, and this increase remained longer with progressing repetitions. During MMF the wake-up phase short-ened from the 1st to the 2nd repetition and the MAP and the HR decreased from the first to all following anaesthesias. During the MMF maintenance, there was a large individual variation in the BP between the GPs, but the single animal always exhibited similar MAP values during all of the repetitions. At 40 min of the MMF anaesthesia, the BG had increased particularly strongly in those anaesthesias that were performed with an interval of 2 d. The BT decrease and the BW increase were not altered. Both anaesthetics can therefore be used repeatedly in the GP with very little change in the anaesthesia profile compared to the single anaesthesias. The GPs developed increasingly stronger defensive reactions which were particularly pronounced with Iso. They reduced the reliability with which the injections of MMF and atropine could be performed and with that the induction of anaesthesia. Although repeated Iso anaesthesia led to lesser repetition-related effects, the highly disadvantageous effects of hypotension, mucous production and hypoventilation with Iso anaesthesia remained and were further worsened by the strong defensive reactions. MMF led to a much more beneficial anaesthesia with the only drawback of altering the BG and the occurring hypothermia. In conclusion, MMF is superior for both single and repeated anaesthesia use in the GP. Iso is only preferable to MMF, if multiple anaesthesias need to be performed on the same day.Die Anästhesie an Meerschweinchen (MS) wurde schon oft als schwierig und risikoreich be-schrieben. Mit diesem Hintergrund wurden die drei häufigsten Narkosemittel, Medetomidin-Midazolam-Fentanyl (MMF), Isofluran (Iso) und Ketamin-Xylazin (KX), hinsichtlich ihres Einflusses auf die physiologischen Parameter im MS untersucht. Die Überwachung vor, während und nach den Anästhesien wurde durch einen abdominal implantierten Radiotelemetriesender durchgeführt. In der ersten Publikation wurde die Implantation des Telemetriesenders detailliert dargestellt. Für den Eingriff wurden die MS mit MMF anästhesiert und die Narkose wurde am Ende des Eingriffes mit AFN (Atipamezol- Flumazenil-Naloxon) wieder aufgehoben. Die Analgesie bestand aus Meloxicam (0,4 mg/kg) und Metamizol (80 mg/kg), womit 30 Minuten vor dem Start der Operation begonnen wurde. Während der Anästhesie wurde die Analgesie zusätzlich über die Fentanyl Komponente des MMFs erhalten. Nach der Implantation wurde Metamizol für 24 Stunden und Meloxicam für 48 h fortgesetzt. Zur antibiotischen Versorgung erhielten die MS Enrofloxacin (10 mg/kg) vor dem Beginn der Operation und in den zwei darauffolgenden Tagen. Unter Verwendung des implantierten Senders wurden der arterielle Blutdruck (BD), die Herzfrequenz (HF) und die Kernkörpertemperatur (KT) in den ersten 24 h nach dem Ende der Implantation gemessen. Die durchgeführte Implantationsherangehensweise führte zu der bisher höchsten publizierten Langzeitüberlebensrate mit 13 von 16 Tieren (81%). Bis 2 Tage nach der Operation verloren die Tiere an Körpergewicht (-11,9 %, -53,6 g). Danach stieg ihr Gewicht jedoch stetig wieder an. Die MS waren nach 8 h nach ihrer abdominalen Operation zu physiologischen Werten in Blutdruck und Körperkerntemperatur und nach 24 h zu normalen HF zurückgekehrt. Aufgrund der hohen Stressanfälligkeit von MS, wurden Empfehlungen für stressarmes Handling, für vor, während und nach der Implantation gegeben. Die Erkenntnisse über die Auswirkungen der Implantation können modelhaft auf andere Bauchoperationen im MS angewendet werden. Die zweite Veröffentlichung beschrieb die Untersuchung der Wirkungen von einmaligen Iso, MMF und KX Anästhesien auf die physiologischen Parameter unter Verwendung der 13 implan-tierten MS. Jedes Tier wurde einmalig mit MMF, Iso und KX im Abstand von 7 d anästhesiert. Der gesamte Anästhesiedurchgang wurde radiotelemetrisch aufgezeichnet und durch manuelle Erhebungen für Atemfrequenz (AF), Reflexe und Blutglukose (BG) ergänzt. Ein Anästhesiedurch-gang beinhaltete 120 min Akklimatisierungszeit, wovon die letzten 15 min als individuelle Baselinewerte gemittelt wurden. Danach wurden die MS prämediziert; bei Iso mit Atropin und bei MMF und KX mit Natriumchlorid als Placebo. Zehn min später wurde die Anästhesie eingeleitet mit einer vorgefluteten Ganzkörperkammer für die Iso Anästhesie und für MMF und KX mit intramuskulären Injektionen in die Hintergliedmaßen. Die Anästhesie wurde für nach 40 min aufgehoben durch Iso-zufuhrstopp, AFN Antagonisierung oder Teilantagonisierung mit Atipamezol. Der BD, die HF, und die KT wurden kontinuierlich bis mindestens 240 min nach Anästhesieeinleitung gemessen. Die AF wurde bis mindestens 55 min gemessen, und die Reflexe wurden bis zum Erreichen eines positiven Stellreflexes getestet. Bei 7,5, 20 und 40 min während der Anästhesie wurden BG Werte erhoben. Mit der Anwendung von Iso erreichten alle MS eine chirurgische Toleranz, mit der MMF-Anästhesie waren es 11 MS und nur 7 erreichten einen operablen Zustand mit KX. Die Induktion, nicht-chirurgische Toleranz und chirurgische Toleranzphasendauer unterschieden sich nicht erheblich zwischen den 3 Anästhetika. Auf die Narkosen mit MMF und Iso folgten kurze Weckzeiten (7,6 & 12,2 min), während es 59,7 min benötigte, bis die MS ihren RR nach KX wiedererlangten. Die MMF-Anästhesie führte zu einer kurzen, deutlichen BD-Abnahme nach Antagonisierung, ansonsten wurden der BD und der HF nur geringfügig verändert. Die Iso-Exposition führte zu einer ausgeprägten Hypotonie während der Anästhesieerhaltung (ca. 20 mmHg) und die HF war zu Beginn der Anästhesie nur leicht erhöht. KX verursachte nur milde Abweichungen von der normalen Physiologie für BD und HF während der Anästhesieerhaltung. Nach der Teilantagonisierung fiel der BD die HF und die KT jedoch ab und die MS erholten sich nur langsam. Alle Anästhetika induzierten eine Hypothermie, aber unter der Iso Narkose verloren die MS am schnellsten und am meisten Körpertemperatur. Direkt nach dem Ende der MMF- und Iso-Narkose konnten sie ihre KT über Kältezittern schnell wieder auf das Ausgangslevel heben. Nach der KX-Anästhesie waren jedoch nur 3 der 7 GPs auf 38,8 ° C KT zurückgekehrt, die anderen 4 hatten auch nach 8 h noch nicht wieder ihre Ausgangskörperkerntemperatur erreicht. Eine Atemdepression trat bei allen 3 Narkosemitteln auf, am ausgeprägtesten jedoch unter der Iso-Narkose (-71%). Dort trat zusätzlich eine starke Reizung der Schleimhäute der Atemwege durch das Atemgas auf. Die nachfolgende Schleimsekretion konnte durch die Atropinprämedikation nur kurzfristig gelindert werden. Der BG-Spiegel stieg während der Anästhesie mit KX (mäßig) und während der MMF-Anästhesie stark an. Die Reflexantworten variierten erheblich zwischen den Anästhetika. Sie waren stark und schnell während der MMF Anästhesie und etwas weniger deutlich ausgeprägt unter der KX-Anwendung. Die Iso-Exposition führte hingegen zu schwachen und langsamen Reflexantworten. Insgesamt ist MMF die Anästhesie der Wahl beim MS; Iso sollte nur für kurze und nicht schmerzhafte Verfahren beraten werden und wir empfehlen die Verwendung von KX Anästhesie bei GPs. Nach der Untersuchung der Einzelanästhesieffekte mit Iso, MMF und KX, beschrieb die dritte Publikation die Auswirkungen der wiederholten MMF- und Iso-Anästhesie. Aufgrund der deutli-chen Nachtteile der KX-Narkose in der Aufwachphase wurde KX von der Wiederholungsstudie ausgeschlossen. Zwölf instrumentierte MS wurden in 2 Anästhesiesets jeweils 6 mal über 3 Wo-chen mit entweder nur Iso oder nur MMF anästhesiert. Der Aufbau der einzelnen Anästhesie-durchgänge war derselbe wie bei in Einzelanästhesien beschrieben. Alle GPs erreichten eine chirurgische Toleranz, und diese konnte für die gewünschten 40 min aufrechterhalten werden. Insgesamt änderten sich die Anästhesieprofile von MMF und Iso nur sehr gering im Verlauf der Anästhesiewiederholung. Durch die wiederholte Atropinprämedikation nahm die HF zu und dieser Anstieg blieb mit fortschreitenden Wiederholungen immer länger bestehen. Bei der MMF Anästhesie verkürzte sich die Aufwachzeit vor allem von der 1. auf die 2. Wiederholung. Der BP und die HF nahmen nach der ersten Wiederholung für die nachfolgenden Anästhesien ab. Während der MMF-Anästhesieerhaltung zeigten die MS große individuelle Variationen im BD. Jedes einzelne Tier blieb jedoch während allen Wiederholungen auf seinem eigenen Niveau. Die BG war bei den MMF-Anästhesien zwischen denen nur 2 Tage lagen 40 min nach der Anästhesieeinleitung besonders hoch. Die KT-Abnahme trat sowohl bei MMF, als auch bei Iso während der Anästhesie auf und die Körpergewichtsentwicklung veränderte sich durch die Wiederholungen nicht. Sowohl Iso als auch MMF können nach diesen Ergebnissen daher wiederholt in MS eingesetzt werden. Trotzdem entwickelten die MS zunehmend stärkere Abwehrreaktionen gegen die Anäs-thesieeinleitung, die bei Iso besonders ausgeprägt waren. Sie reduzierten die Zuverlässigkeit, mit der die Injektionen von MMF und Atropin durchgeführt werden konnten und damit die Induktion der Anästhesie. Die Iso-Anästhesie führte zwar zu geringeren Wiederholungswirkungen im Vergleich zu MMF, das Anästhesieprofil mit der starken Atemdepression und Schleimproduktion und der starken Hypotension bestand jedoch weiterhin. Insgesamt sind die Effekte der Wiederholungen bei der MMF Anästhesie weitgehend vernachlässigbar und das Anästhesieprofil ist wesentlich vorteilhafter für die MS. Daher ist MMF für die einfache und wiederholte Anästhesie im MS das Anästhetikum der Wahl, es sei denn am selben Tag müssen mehrere Anästhesien durchgeführt werden müssen. In dem Fall ist Iso vorzuziehen