Recovery Time

The aim of this study was to determine in statistical terms, the systolic blood pressure recovery time (SBPRT) and the effects of age, gender and exercise intensity in a large sample of apparently healthy non-athletic adults (n=597, aged 18-68). Subjects performed mild, moderate, and severe ergometer exercise tests. Blood pressure was measured before exercise (after 10 and 15 minutes of rest), during exercise (at 2-minute intervals) and at every minute of post-exercise recovery until systolic blood pressure (SBP) returned to baseline. The present findings indicate that the average values of SBPRT were between 5 and 7 minutes regardless of age, gender or exercise intensity. Systolic blood pressure recovery time increased with each age group (p<0.001) in all the exercise intensities. Young and middle-aged men indicated higher SBPRT than females (p<0.001) in mild and moderate exercise regimens. In men, SBPRT appeared to decrease with increase in exercise intensity (p<0.001) but indicated no significant differences amongst the exercise intensities in women. The present study therefore indicated mean SBPRT values that were consistent with previously reported values and which indicated age and gender effects following three exercise intensities of cycle ergometer. The reported data will help clinicians to define post-exercise SBP responses in statistical terms stratified by age, gender and exercise intensity in future investigations and during clinical assessment of individuals.

Checkpointing with rollback recovery is a well-known method for achieving fault-tolerance in distributed systems. In this work, we introduce algorithms for checkpointing and rollback recovery on asynchronous unidirectional and bi-directional ring networks. The proposed checkpointing algorithms can handle multiple concurrent initiations by different processes. While taking checkpoints, processes do not have to take into consideration any application message dependency. The synchronization is achieved by passing control messages among the processes. Application messages are acknowledged. Each process maintains a list of unacknowledged messages. Here we use a logical checkpoint, which is a standard checkpoint (i.e., snapshot of the process) plus a list of messages that have been sent by this process but are unacknowledged at the time of taking the checkpoint. The worst case message complexity of the proposed checkpointing algorithm is O(kn) when k initiators initiate concurrently. The time complexity is O(n). For the recovery algorithm, time and message complexities are both O(n).

One of the desirable features of any network is its ability to keep services running despite a link or node failure. This ability is usually referred to as network resilience and has become a key demand from service providers. Resilient networks recover from a failure by repairing themselves automatically by diverting traffic from the failed part of the network to another portion of the network. This traffic diversion process should be fast enough to ensure that the interruption of service due to a link or node failure is either unnoticeable or as small as possible. The new path taken by a diverted traffic can be computed at the time a failure occurs through a procedure called rerouting. Alternatively the path can be computed before a failure occurs through a procedure called fast reroute. Much attention is currently being paid to fast reroute because service providers who are used to the 50-ms failure recovery time associated with SONET networks are demanding the same feature from IP and MPLS networks. While this requirement can easily be met in SONET because it operates at the physical layer, it is not easily met in IP and MPLS networks that operate above the physical layer. However, over the last few years, several schemes have been proposed for accomplishing 50-ms fast reroutes for IP and MPLS networks. The purpose of this paper is to provide a survey of the IP fast reroute and MPLS fast reroute schemes that have been proposed.

Growth of adult traíras Hoplias malabaricus ceased and body mass (M) decreased during starvation periods of 30, 60, 90, 150, 180 and 240 days. Hepatic reserves were mobilized in fish starved for 30 days, but liver mass of fish starved for longer periods was not significantly different from those starved for 30 days. Perivisceral fat bodies were consumed gradually, being completely exhausted after 240 days of food deprivation. Length of starvation was associated with a significant decrease in the oxygen uptake (Ṽ 2 ). In spite of this reduction, the respiratory frequency (f R ) was kept nearly constant during the starvation periods. The haematocrit and the number of red blood cells decreased after 150 and 240 days of starvation, respectively. These parameters did not recover after refeeding (after 90 and 240 days of starvation). This hypometabolic state in response to food deprivation contributed to energy conservation during these periods. Traíras can survive food deprivation for periods of up to 180 days without reductions in metabolism and when they do become hypometabolic, normal metabolic rates are rapidly restored upon refeeding.

In generalized multiprotocol label switching (GMPLS)-enabled wavelength-switched optical networks (WSONs), shared path protection (SPP) attains 100% survivability with an acceptable recovery time, for lightpaths affected by a single-link failure. This is achieved by sharing backup resources. Nevertheless, neither the standard OSPF-TE nor the RSVP-TE protocols support the respective flooding/collection of shareable resource information for SPP purposes. This prevents the source node from computing backup paths exploiting the SPP advantages, and the destination node from performing optimal wavelength assignment (WA) favoring the reuse of shareable resources. In this paper, we experimentally evaluate, in the GMPLS control plane of the ADRENALINE testbed, the performance improvements when shareable resource information is either flooded (by enhanced OSPF-TE) and/or collected (by enhanced RSVP-TE), under the wavelength continuity constraint. Additionally, we propose efficient SPP path computation and WA algorithms, considering three information dissemination strategies: aggregated unreserved bandwidth, aggregated shared bandwidth, and wavelength-channel granularity.

Ahstract -In this paper we introduce a siniple adapthe control mechaniwi into nonlinear s>stem\ which are capable of complicated oscillaton \tates and chaotic dynamics. We show that it provides efficient regulation while displa! ing novel behavior. Sudden perturbations in the s!stem'\ parameters can degenerate into chaotic bursts with no precursors, When such bursts occur, the s!stem first re\erberates wildl! and then reco\ers in times that are in\er\ely proportional to the d f f n e s s of the control. We a h exhibit a general control principle which provides a quantitatite relation between the nia\imum amplitude of a perturbation from which a s!\teni can recober, and the \peed at which it does \o.

A fault current limiter (FCL) based on an arrangement of parallel connected high temperature superconducting tapes constituting a limiter element was designed and tested in 220 V line for a fault current peak between 1 kA to 2 kA. The limiter employed second generation (2G) HTS tapes of YBCO coated conductor reinforced with stainless steel. Four tapes were electrically connected in parallel with 0.4 m effective length per element wherein 16 elements connected in series constitutes a single-phase unit. The FCL performance was evaluated through over-current and current fault tests. Its recovery characteristics were used to design the shunt protection. The designed limiting ratio is 4 for 16 elements and the experimental result for one element showed a 20% limiting ratio. For the fault current test one element can withstand five cycles of fault without degradation. It was observed recovery times below 0.5 s under nominal load using a shunt resistance of 173 m.

Deadlock detection and recovery-based routing schemes for wormhole networks have gained attraction because unlike deadlock avoidance-based schemes, they do not restrict routing adaptability. In order to alleviate the overhead of running a recovery procedure, the studies on deadlock detection have focused on the accuracy of deadlock detection, trying to reduce the number of false detections. This paper proposes both deadlock detection and recovery schemes. The proposed detection scheme is based on the turn model and designed to declare only one packet per simple cycle of blocked packets as deadlocked. Our recovery scheme adjusts the time-out value flexibly according to the utilization rate of the recovery resources, rather than fixing a single time-out value as in previous schemes. As a consequence, it not only prevents saturation of the recovery resources by deadlocked packets but also reduces congestion of normal buffers at heavy loads. Simulation experiments show that the proposed deadlock detection scheme significantly reduces the number of false deadlock detections over previous schemes for low to moderate time-out thresholds. It is also found that the proposed recovery scheme prevents overloading of the recovery resources, yielding better network performance.

Little is known about the sinoatrial automatism and atrioventricular conduction of trained individuals who present a normal resting electrocardiogram. We used transesophageal atrial stimulation, a minimally invasive technique, to evaluate aerobically trained athletes (n 10) and sedentary individuals (n 10) with normal resting electrocardiograms, to test the hypothesis that parasympathetic tone, as detected by heart rate variability, could be associated with changes in sinoatrial automatism and atrioventricular conduction. Corrected sinus node recovery time tended to be longer in athletes than in sedentary individuals, but this difference did not reach statistical signi®cance. The Wenckebach point occurred at a lower rate in athletes than in the controls. Over a 24-h period of measurement, the mean RR interval was longer in the athletes than in the sedentary individuals. The mean square root of successive dierences (rMSSD) tended to be higher in athletes than in controls, but this dierence did not reach statistical signi®cance. There was a moderate correlation (r 0.48, P < 0.05) between the index of atrioventricular conduction, the rate at the Wenckebach point, and the logarithmically transformed rMSSD. Thus, as a corollary to its eects on the sinus node, where increased parasympathetic tone, decreased sympathetic tone, and non-autonomic components may contribute to sinus bradycardia, it is possible that athletic training may also induce intrinsic adaptations in the conduction system, which could contribute to the higher prevalence of atrioventricular conduction abnormalities observed in athletes.

Introduction and hypothesis In a retrospective study, the sacrospinous hysteropexy was associated with a shorter recovery time compared to a vaginal hysterectomy with no differences in anatomical outcomes. No randomized trials are performed. Methods Sixty-six women with stage2-4 uterine descent were randomized for vaginal hysterectomy(31) or sacrospinous hysteropexy(35). Recovery time, anatomical outcomes, functional outcomes, and quality of life were measured. Results Length of time to return to work was shorter after a sacrospinous hysteropexy (43 versus 66 days, p=0.02). The difference in risk for recurrent prolapse stage2 or more of the apical compartment at 1-year follow-up was 17% (95% confidence interval, 2 to 30) in favor of the vaginal hysterectomy. No differences in quality of life and urogenital symptoms were found. Conclusions The sacrospinous hysteropexy for uterine descent is associated with an earlier recovery time, more recurrent apical prolapses but no differences in functional outcomes, and quality of life.

Abstract— Border gateway protocol (BGP) is the standard routing protocol between various autonomous systems (AS) in the Internet. In the event of a failure, BGP may repeatedly withdraw some routes and advertise new ones until a stable state is reached. It is known that the corresponding ...

In generalized multiprotocol label switching (GMPLS)-enabled wavelength-switched optical networks (WSONs), shared path protection (SPP) attains 100% survivability with an acceptable recovery time, for lightpaths affected by a single-link failure. This is achieved by sharing backup resources. Nevertheless, neither the standard OSPF-TE nor the RSVP-TE protocols support the respective flooding/collection of shareable resource information for SPP purposes. This prevents the source node from computing backup paths exploiting the SPP advantages, and the destination node from performing optimal wavelength assignment (WA) favoring the reuse of shareable resources. In this paper, we experimentally evaluate, in the GMPLS control plane of the ADRENALINE testbed, the performance improvements when shareable resource information is either flooded (by enhanced OSPF-TE) and/or collected (by enhanced RSVP-TE), under the wavelength continuity constraint. Additionally, we propose efficient SPP path computation and WA algorithms, considering three information dissemination strategies: aggregated unreserved bandwidth, aggregated shared bandwidth, and wavelength-channel granularity.

This paper proposes an architecture of a next-generation Internet eXchange (IX) based on the Generalized Multi-Protocol Label Switching (GMPLS) technologies and the photonic cross-connect (PXC), hereafter referred to a Lambda-IX. At first, we investigate a basic Lambda-IX model where the PXC provides a GMPLS-controlled lambda label-switched path (LSP) to interconnect different ISPs' border routers. We verify that the proposed Lambda-IX model can achieve the lambda-based and resilient interconnection for the ISPs, thanks to the PXC's bit-rate insensitive operation as well as fast restoration operation. In addition, once GMPLS functionalities are introduced on the border routers as well as the PXC, very flexible interconnection can be achieved such as demand-based creation and deletion of lambda LSPs. Next, we initiatively demonstrate an experimental Lambda-IX using a PXC and IP/MPLS routers. A Lambda-LSP with OC-192 bandwidth can be successfully created by using the GMPLS RSVP-TE signaling protocol via a control plane, and an EGP session of Border Gateway Protocol 4 (BGP-4) can be established over the Lambda-LSP created between the GMPLS-enabled border routers via a data plane. We also evaluate the fault recovery operation in the case where such Lambda-IXs are consisted of several PXCs and demonstrate that the Lambda-LSP as well as the corresponding BGP session can be restored with a fast recovery time of less than 1s. Through these investigation and demonstration, it is revealed that the Lambda-IX can be put to practical use aiming at inter-exchanging a large traffic in a near future, while enriching the functions of IX.

Time Wrap algorithm is a well-known mechanism of optimistic synchronization in a parallel discrete-event simulation (PDES) system. It offers a run time recovery mechanism that deals with the causality errors. For an efficient use of rollback, the global virtual time (GVT) computation is performed to reclaim the memory, commit the output, detect the termination, and handle the errors. This paper presents a new unacknowledged message list (UML) scheme for an efficient and accurate GVT computation. The proposed UML scheme is based on the assumption that certain variables are accessible by all processors. In addition to GVT computation, the proposed UML scheme provides an effective solution for both simultaneous reporting and transient message problems in the context of synchronous algorithm. To support the proposed UML approach, two algorithms are presented in details, with a proof of its correctness. Empirical evidence from an experimental study of the proposed UML scheme on PHOLD benchmark fully confirms the theoretical outcomes of this paper.

Biopolymer used for the production of nanoparticles (NPs) has attracted increasing attention. In the presence article we use aqueous solution of polysaccharide Cyamopsis tetragonaloba commonly known as guar gum (GG), from plants. GG acts as reductive preparation of silver nanoparticles which are found to be <10 nm in size. The uniformity of the NPs size was measured by the SEM and TEM, while a face centered cubic structure of crystalline silver nanoparticles was characterized using powder X-ray diffraction technique. Aqueous ammonia sensing study of polymer/silver nanoparticles nanocomposite (GG/AgNPs NC) was performed by optical method based on surface plasmon resonance (SPR). The performances of optical sensor were investigated which provide the excellent result. The response time of 2-3 s and the detection limit of ammonia solution, 1 ppm were found at room temperature. Thus, in future this room temperature optical ammonia sensor can be used for clinical and medical diagnosis for detecting low ammonia level in biological fluids, such as plasma, sweat, saliva, cerebrospinal liquid or biological samples in general for various biomedical applications in human.

The paper provides an overview of the resilient schemes currently adopted in network architectures based on IP over Automatically Switched Optical Networks (ASONs)/Generalized Multiprotocol Label Switching (GMPLS) based optical networks, namely the Optical Internet. In addition it outlooks the raising challenges and possible solutions in implementing advanced resilient schemes capable of satisfying the requirements of the different applications carried by a single multi-layer network infrastructure.

Time Wrap algorithm is a well-known mechanism of optimistic synchronization in a parallel discrete-event simulation (PDES) system. It offers a run time recovery mechanism that deals with the causality errors. For an efficient use of rollback, the global virtual time (GVT) computation is performed to reclaim the memory, commit the output, detect the termination, and handle the errors. This paper presents a new unacknowledged message list (UML) scheme for an efficient and accurate GVT computation. The proposed UML scheme is based on the assumption that certain variables are accessible by all processors. In addition to GVT computation, the proposed UML scheme provides an effective solution for both simultaneous reporting and transient message problems in the context of synchronous algorithm. To support the proposed UML approach, two algorithms are presented in details, with a proof of its correctness. Empirical evidence from an experimental study of the proposed UML scheme on PHOLD benchmark fully confirms the theoretical outcomes of this paper.

Time Wrap algorithm is a well-known mechanism of optimistic synchronization in a parallel discrete-event simulation (PDES) system. It offers a run time recovery mechanism that deals with the causality errors. For an efficient use of rollback, the global virtual time (GVT) computation is performed to reclaim the memory, commit the output, detect the termination, and handle the errors. This paper presents a new unacknowledged message list (UML) scheme for an efficient and accurate GVT computation. The proposed UML scheme is based on the assumption that certain variables are accessible by all processors. In addition to GVT computation, the proposed UML scheme provides an effective solution for both simultaneous reporting and transient message problems in the context of synchronous algorithm. To support the proposed UML approach, two algorithms are presented in details, with a proof of its correctness. Empirical evidence from an experimental study of the proposed UML scheme on PHOLD benchmark fully confirms the theoretical outcomes of this paper.

Background: Clinical depression and postdialysis fatigue are important concerns for patients with kidney failure and can have a negative impact on quality of life and survival. Study Design: The FREEDOM (Following Rehabilitation, Economics and Everyday-Dialysis Outcome Measurements) Study is an ongoing prospective cohort study investigating the clinical and economic benefits of daily (6 times per week) hemodialysis (HD). In this interim report, as part of an a priori planned analysis, we examine the long-term impact of daily HD on depressive symptoms, measured using the Beck Depression Inventory (BDI) survey, and postdialysis recovery time, measured using a previously validated questionnaire. Setting & Participants: Adult patients initiating daily HD with a planned 12-month follow-up. Outcomes & Measurements: The BDI survey and postdialysis recovery time question were administered at baseline, and changes were assessed at months 4 and 12. Results: 239 participants were enrolled (intention-to-treat cohort) and 128 completed the study (per-protocol cohort). Mean age was 52 years, 64% were men, 55% had an arteriovenous fistula, and 90% transitioned from in-center HD therapy. In the per-protocol cohort, there was a significant decrease in mean BDI score over 12 months (11.2 [95% CI, 9.6-12.9] vs 7.8 [95% CI, 6.5-9.1]; P Ͻ 0.001). For robustness, the intention-to-treat analysis was performed, yielding similar results. The percentage of patients with depressive symptoms (BDI score Ͼ10) significantly decreased during 12 months (41% vs 27%; P ϭ 0.03). Similarly, in the per-protocol cohort, there was a significant decrease in postdialysis recovery time over 12 months (476 [95% CI, 359-594] vs 63 minutes [95% CI, 32-95]; P Ͻ 0.001). The intention-to-treat analysis yielded similar results. The percentage of patients experiencing prolonged postdialysis recovery time (Ն60 minutes) also significantly decreased (81% vs 35%; P ϭ 0.001). Limitations: Observational study with lack of control arm. Conclusions: Daily HD is associated with long-term improvement in depressive symptoms and postdialysis recovery time.

This paper discusses a modeling approach to robust crew pairing when a set of extra flights is likely to be added to the regular flight schedule. The set of these possible extra flights is known at the planning stage. We demonstrate that these extra flights may be incorporated into the schedule if necessary by modifying the planned crew pairings appropriately and without delaying or canceling existing flights. To this end, we either identify a pair of crews whose schedules may be (partially) swapped while adding an extra flight into the schedule or show that an extra flight may be inserted into the schedule of a crew without affecting others. We note that deadheading may be necessary in either case. For these two types of solutions, we define the appropriate feasibility rules with respect to the common airline regulations. We then propose two robust mathematical programming models that consider incorporating such solutions into the set of selected pairings while keeping the increase in the crew cost at an acceptable level. The baseline solution for comparison is found by a conventional crew pairing model in the literature which ignores robustness at the planning stage and relies on recovery procedures at the time of operation. We also propose the variations of the two models, where the double counting of the possible solutions across extra flights is prevented. Finally, we conduct computational experiments on a set of data generated from the actual data of an airline company. We solve the crew pairing problem both with the proposed robust models and the conventional model. Our results demonstrate the benefits of the proposed modeling approach and indicate that the proposed robust models provide natural options to recovery without disrupting the existing flights at a relatively small incremental cost, which is visible at the planning stage.

Nanocrystalline ZnO based sensor using micromachined silicon substrate has been reported for efficient detection of methane as opposed to conventional SnO 2 based micromachined sensors for its higher compatibility to silicon IC technology and greater response. A suitably designed nickel microheater has been fabricated on to the micromachined Si platform. The optimum temperature for highest response magnitude and lowest response time were found to be 250°C although relatively high (76.6%) response is obtained even at as low as 150°C. Our study showed quite high response magnitude (87.3%), appreciably fast response time (8.3 s) and recovery time (17.8 s) to 1.0% methane at 250°C. The sensor showed appreciably fast response (14.3 s) and recovery time (28.7 s) at 150°C. The power consumption at an operating temperature of 250°C was 120 mW and at 150°C is only $70 mW. Moreover, this type of sensor was found to give fairly appreciable response for lower methane concentrations (0.01%) also. For higher methane concentrations (>0.5%) response is detectable even at 100°C where the power consumption is only $40 mW.

The resistivity of several materials varies predictably with temperature; this makes them suitable for the use as temperature sensors. If these material gets heated due to the electric current passing through it and if it preserves a uniform temperature distribution during heating, then its total resistance would accurately reflect its temperature, allowing it to simultaneously act as both a temperature sensor and a self heater. This paper describes the results of indigenously formulated lead free thick film NTC thermistor paste composition with sheet resistance of 1 kO/h used for heater application. The current-voltage, temperature-current characteristics, dissipation constant, response and recovery time of the heater are reported. The maximum current handling capacity of the prepared thick film thermistor was observed at 300 mA and the temperature achieved to 340°C. Therefore, the heater was tested at a constant current of 300 mA for 24 h, which did not show any extreme change in behaviour and the temperature of the thermistor/ heater remained constant to 340 ± 5°C.

Legacy ring-based networks have been deployed in conjunction with SONET/SDH technology to provide survivability to transport networks, and they achieve service recovery within 50 ms after fault detection. Current generalized multiprotocol label switching (GMPLS)-controlled optical transport networks need efficient resilience mechanisms to allow recovery times equivalent to those granted by SONET/SDH networks. In this paper, dedicated and shared optical multiplex section (OMS) protection systems are proposed. Both solutions consist of a mechanism based on extensions of the GMPLS link management protocol (LMP) to properly manage the protection actions, and both utilize a new reconfigurable optical add/drop multiplexer (ROADM) design to support the protection schemes. The performance of both solutions has been experimentally evaluated.

Traditional TCP has a good congestion control strategy that adapts its sending rate in accordance with network congestion. In addition, a fast recovery algorithm can help TCP achieve better throughput by responding to temporary network congestion well. However, if multiple packet losses occur, the time to enter congestion avoidance phase would be delayed due to the long recovery time. Moreover, during the recovery phase, TCP freezes congestion window size until all lost packets are recovered, and this can make recovery time much longer resulting in performance degradation. To mitigate such recovery overhead, we propose Momentary recovery algorithm that recovers packet loss without an extra recovery phase. As other TCP and variants, our algorithm also halves the congestion window size when packet drop is detected, but it performs congestion avoidance phase immediately as if loss recovery is completed. For lost packets, TCP sender transmits them along with normal packets as long as congestion window permits rather than performs fast retransmission. In this manner, we can eliminate recovery overhead efficiently and reach steady state momentarily after network congestion. Finally, we provide a simulation based study on TCP recovery behaviors and confirm that our Momentary recovery algorithm always shows better performance compared with NewReno, SACK, and FACK. key words: transmission control protocol, loss recovery algorithm, congestion control, recovery overhead * In this paper, we separate temporary increments by duplicate ACKs from opening the congestion window size(cwnd) during fast recovery since it does not aim to perform additive increase.

Time Wrap algorithm is a well-known mechanism of optimistic synchronization in a parallel discrete-event simulation (PDES) system. It offers a run time recovery mechanism that deals with the causality errors. For an efficient use of rollback, the global virtual time (GVT) computation is performed to reclaim the memory, commit the output, detect the termination, and handle the errors. This paper presents a new unacknowledged message list (UML) scheme for an efficient and accurate GVT computation. The proposed UML scheme is based on the assumption that certain variables are accessible by all processors. In addition to GVT computation, the proposed UML scheme provides an effective solution for both simultaneous reporting and transient message problems in the context of synchronous algorithm. To support the proposed UML approach, two algorithms are presented in details, with a proof of its correctness. Empirical evidence from an experimental study of the proposed UML scheme on PHOLD benchmark fully confirms the theoretical outcomes of this paper.

ABSTRACT An original electrochemical process to prepare SnO2 gas sensors is detailed and correlated to electrical behaviour under gas environment. In particular conditions, Tin material was electrodeposited on insulating substrate to form a thin film principally composed of a single layer of individual nanoaggregates (5–10 nm in size). After tin electrodeposition, these supported aggregates were oxidised at air or pressurized oxygen to induce the formation of a fractal SnO2 film. From these resulting active films, electrical measurements were carried out in ethanol and 300 ppm CO atmospheres. The results show, a sensitivity of 400% at 227 °C in the ethanol case with a response time of 140 s. When the temperature of electrical measurements increases, response and recovery times decrease. However, the sensing amplitude was not modified (Sensitivity around 4) between 250 and 300 °C. In the case of CO, the sensor presented a typical response with a factor of about 2.5 at 250 °C. A fractal dimension between 1.4 and 1.6 is found for fractal-shaped samples allowing an increase of specific surface in contact with gases. However, its does not effect sensitivity, which depends mainly on grain size.

Halcrow and Unipart Rail have developed and are trialling a simple in-cab system which continually advises train drivers of the train&#x27;s time with respect to a pre-calculated time-distance profile. The profile is set up to save energy by making use of unused recovery time in the timetable. ...

In this paper, we propose a non-uniform biasing technique to improve the uniformity of the semiconductor optical amplifier (SOA) gain for ultra-high speed applications. In ultra-high speed applications, rapid gain recovery of the SOA is necessary to minimize the gain standard deviation and thus reducing system power penalties. A triangular shape biasing current is used in order to accelerate the SOA gain recovery while reducing the gain standard deviation. The effect of the non-uniform bias current on the SOA gain is investigated. The SOA is modeled using a segmentation method and the detailed theoretical analysis for the model is presented. The SOA gain and the output gain profiles achieved when injected with a burst of input Gaussian pulses for the non-uniform and the corresponding uniform techniques are also investigated. The operation principle is simulated and results show the boundaries and requirements in order to achieve the desired SOA bit rate for a range of different input powers. A reduction (at 1 mW input power) of 1.5 dB, 0.3 dB and 0.1 dB in the gain standard deviation is achieved for the input data rates of 10, 20 and 40 Gb/s, respectively. Index Terms-carrier density, gain response, recovery time, semiconductor optical amplifier (SOA).

Our quantitative approach to recovery procedures' assessment considers combining the following parameters into the single index: availability of the recovered connections, assured quality of the backup path, recovery time, cost and traffic affected by a failure. A common framework of recovery quality is proposed and some guidelines on how to calculate it are presented.

Electrical and thermal characteristics of Yttrium Barium Copper Oxide (YBCO) coated conductors (CCs) with different architectures, with and without stabilizer layers, in resistive fault current limiters (RSFCLs) have been widely studied. In this study, the recovery of the superconducting state under different conditions (no-load and under load) is analyzed for subsequent fault current limitation. Test of modular RSFCL using commercial coated conductor with and without the assistance of an air-core power reactor was carried out. Shunt-assisted quench tests were investigated and measurements have been performed in short samples employed in the construction of modular unit with 6 stacks of 0.7-m length of 12-mm width YBCO CC tapes. Using the pulsed current method (PCM), the quench current (from Ic up to 3 × Ic) for a time period from 16.6 to 80 ms was applied to evaluate the temperature and recovery time, by the power losses, generated after the second quench in sequence. The RSFCL operates in a distribution grid protected by a recloser switch with intervals of 300 ms, 900 ms, and 1.2 s. For these time intervals, it is necessary to verify if full recovery behavior happens.

Network survivability is becoming an important issue and a topical subject in WDM optical mesh networks. Many works have studied network survivability. However, few works have focused on survivability in multi-domain optical networks. This paper reviews the literature on survivability against failures in multi-domain optical networks. The main objective of this study is to evaluate and analyze existing solutions and to compare their performance in terms of different criteria: resource utilization, ratio of rejected connections and recovery time.

Recovery Time in Congenital LQTS. Introduction: Sympathetic stimulation play.s an important roie in the genesis of OT(t') prolongation and ventricular arrhythmias in cftnginital long QT syndrome (LQTS). Permanent pacemaker as well as /3 hlockers are reported to be etTcctive in the management of this syndrome. The purpose of this study was to examine inliuence (tf epinephrine (a-and ^S-adrenergic stimulation), propranolol (0 hlocker), and atrial pacing on Ihe spatial di,stribution of repolarization using hody surface recovery time (RT) in congenital LQTS. Methods and Restdts: Body surface mapping was recorded in 16 patients with congenital I ,QTS and 20 control patients before and after epinephrine infusion (d.l /xg/kg per niin). (»ral propranolol {I to 2 mg/kg per day), addition of epinephrine during oral propranolol, atrial pacing at a cycle length of 600 or 750 msec, and addition of epinephrine during atrial pacing. The RT, thai is, the interval between the QRS onset and the maximum dVVdt point in the ST-T segment, was measured automatically by a computer from each of the 87 mapping leads, and the corrected RT (RT^) was calculated using Bazett's method. In patients with congenital LQTS, epinephrine markedly changed the T(U) wave morphology and spatial distribution of RT, especially the distribution <if iTiaximum RT of the left anterior chest and buck, Kpinephriiie prolonged tbe maximum RT^ and the minimum RT^ in 87 leads and increased the RT. dispersion (difference between maximum and minimum RT^ in each patient). Neither propranolol nor atrial pacing changed the T(U) wave morphology, spatial distribution of RT, or any RT, parameters at rest. Propranolol prevented the influences of epinephrine on the T(U) wave morphology, spatial distribution of RT, and RT^, parameters, whereas atrial pacing did not. In control patients, marked changes of the T(U) wave morphology and RT, parameters were not recognized during the entire protocol. Conclttsions: Our results indicate that epinephrine markedly changes the spatial distrihution of repolarization and increases the dispersion of repolarization, which probably are linked to arrhythmogenesis in congenital LQTS. The data suggest that propranolol but not iitrial pacing are effective to suppress repolarization abnormalities during sympathetic stimulation.

Our quantitative approach to recovery procedures' assessment considers combining the following parameters into the single index: availability of the recovered connections, assured quality of the backup path, recovery time, cost and traffic affected by a failure. A common framework of recovery quality is proposed and some guidelines on how to calculate it are presented.

The introduction of 'Catch and Release' fishery programs are now widely employed by fisheries managers in most Atlantic Provinces, primarily due to the recent decline of Atlantic salmon stocks on the east coast of Canada. However, there is still considerable debate among special interest groups and regulators as to the effectiveness of the technique. Heart rate telemetry has been utilized as a tool for the assessment of metabolic rate in wild fish by a number of investigators, and was employed in the present study in order to assess recovery following staged angling events in Atlantic salmon. Wild Atlantic salmon were successfully angled at 20 ± 2 • C and 16.5 ± 1 • C at Noel Paul's Brook, Newfoundland. In addition, hatchery reared Atlantic salmon were angled at the Ontario Ministry of Agriculture and Fisheries Research Station, Alma, Ontario, at a temperature of 8 ± 1 • C. Survival rate for the angled salmon was 20% at 20 ± 2 • C; 100% at 16.5 ± 1 • C; and 100% at 8 ± 1 • C. Mean resting heart rate for the fish angled at 16.5 • C and 20 • C was approximately 1.6 and 1.8 times greater than that of fish angled at 8 • C. Heart rate, post angling, was found to increase 1.2 fold in the 8 • C group, 1.3 fold in the 16.5 • C group and approximately 1.15 fold in the 20 • C group. Time to recovery was assessed as a return to observed resting heart rate for each individual fish and was found to be similar for both the 8 • C and 16.5 • C angled groups (approximately 16 h). Although heart rate telemetry in fish is, perhaps, not an ideal measure of metabolic rate, the present study has demonstrated that remote monitoring of heart rate is a good indicator of post exercise physiological activity.

Objective: To evaluate the effects of sensory-amplitude electric stimulation (SES) of the paretic leg on motor recovery and gait kinematics of patients with stroke. Design: Randomized, controlled, double-blind study. Setting: Rehabilitation ward and gait laboratory of a university hospital. Participants: A total of 30 consecutive inpatients with stroke (mean age, 63.2y), all within 6 months poststroke and without volitional ankle dorsiflexion were studied. Intervention: Both the SES group (nϭ15) and the placebo group (nϭ15) participated in a conventional stroke rehabilitation program 5 days a week for 4 weeks. The SES group also received 30 minutes of SES to the paretic leg without muscle contraction 5 days a week for 4 weeks. Main Outcome Measures: Brunnstrom stages of motor recovery and time-distance and kinematic characteristics of gait. Results: Brunnstrom stages improved significantly in both groups (PϽ.05). In total, 58% of the SES group and 56% of the placebo group gained voluntary ankle dorsiflexion. The between-group difference of percentage change was not significant (PϾ.05). Gait kinematics was improved in both groups, but the between-group difference was not significant. Conclusions: In our patients with stroke, SES of the paretic leg was not superior to placebo in terms of lower-extremity motor recovery and gait kinematics.

Time Wrap algorithm is a well-known mechanism of optimistic synchronization in a parallel discrete-event simulation (PDES) system. It offers a run time recovery mechanism that deals with the causality errors. For an efficient use of rollback, the global virtual time (GVT) computation is performed to reclaim the memory, commit the output, detect the termination, and handle the errors. This paper presents a new unacknowledged message list (UML) scheme for an efficient and accurate GVT computation. The proposed UML scheme is based on the assumption that certain variables are accessible by all processors. In addition to GVT computation, the proposed UML scheme provides an effective solution for both simultaneous reporting and transient message problems in the context of synchronous algorithm. To support the proposed UML approach, two algorithms are presented in details, with a proof of its correctness. Empirical evidence from an experimental study of the proposed UML scheme on PHOLD benchmark fully confirms the theoretical outcomes of this paper.

In generalized multiprotocol label switching (GMPLS)-enabled wavelength-switched optical networks (WSONs), shared path protection (SPP) attains 100% survivability with an acceptable recovery time, for lightpaths affected by a single-link failure. This is achieved by sharing backup resources. Nevertheless, neither the standard OSPF-TE nor the RSVP-TE protocols support the respective flooding/collection of shareable resource information for SPP purposes. This prevents the source node from computing backup paths exploiting the SPP advantages, and the destination node from performing optimal wavelength assignment (WA) favoring the reuse of shareable resources. In this paper, we experimentally evaluate, in the GMPLS control plane of the ADRENALINE testbed, the performance improvements when shareable resource information is either flooded (by enhanced OSPF-TE) and/or collected (by enhanced RSVP-TE), under the wavelength continuity constraint. Additionally, we propose efficient SPP path computation and WA algorithms, considering three information dissemination strategies: aggregated unreserved bandwidth, aggregated shared bandwidth, and wavelength-channel granularity. Index Terms-Distributed signaling, dynamic routing and wavelength assignment (RWA), generalized multiprotocol label switching (GMPLS), shared path protection (SPP), wavelength continuity constraint (WCC), wavelength-switched optical network (WSON).

Legacy ring-based networks have been deployed in conjunction with SONET/SDH technology to provide survivability to transport networks, and they achieve service recovery within 50 ms after fault detection. Current generalized multiprotocol label switching (GMPLS)-controlled optical transport networks need efficient resilience mechanisms to allow recovery times equivalent to those granted by SONET/SDH networks. In this paper, dedicated and shared optical multiplex section (OMS) protection systems are proposed. Both solutions consist of a mechanism based on extensions of the GMPLS link management protocol (LMP) to properly manage the protection actions, and both utilize a new reconfigurable optical add/drop multiplexer (ROADM) design to support the protection schemes. The performance of both solutions has been experimentally evaluated.

In this paper, we propose a non-uniform biasing technique to improve the uniformity of the semiconductor optical amplifier (SOA) gain for ultra-high speed applications. In ultra-high speed applications, rapid gain recovery of the SOA is necessary to minimize the gain standard deviation and thus reducing system power penalties. A triangular shape biasing current is used in order to accelerate the SOA gain recovery while reducing the gain standard deviation. The effect of the non-uniform bias current on the SOA gain is investigated. The SOA is modeled using a segmentation method and the detailed theoretical analysis for the model is presented. The SOA gain and the output gain profiles achieved when injected with a burst of input Gaussian pulses for the non-uniform and the corresponding uniform techniques are also investigated. The operation principle is simulated and results show the boundaries and requirements in order to achieve the desired SOA bit rate for a range of different input powers. A reduction (at 1 mW input power) of 1.5 dB, 0.3 dB and 0.1 dB in the gain standard deviation is achieved for the input data rates of 10, 20 and 40 Gb/s, respectively.

This paper focuses on the modelling, simulation and analysis of the behaviour of the electromagnetic shaft synchronization system with two identical single-phase induction motors. Motors speed-control and their synchronization are achieved by this electromagnetic shaft. A mathematical model has been suggested to describe this synchronization system. The traditional electromagnetic shaft synchronization system has been modified by adding an adjustable air-gap within the core of the three-phase inductive rheostat element in the common rotor circuit. The length of this air-gap is adjustable. This makes the use of the electromagnetic shaft more flexible. This makes it possible to control the speeds of the motors and regulate the synchronization capability or the recovery time of the system response (quality indicators). The quality indicators of the proposed synchronization system have been analysed. The suggested system has been mathematically modelled and simulated using MATLAB/Simulink. The proposed system has been tested for various load conditions. Results of the steady state and dynamics of the electromagnetic shaft synchronization system have been illustrated.

The resistivity of several materials varies predictably with temperature; this makes them suitable for the use as temperature sensors. If these material gets heated due to the electric current passing through it and if it preserves a uniform temperature distribution during heating, then its total resistance would accurately reflect its temperature, allowing it to simultaneously act as both a temperature sensor and a self heater. This paper describes the results of indigenously formulated lead free thick film NTC thermistor paste composition with sheet resistance of 1 kO/h used for heater application. The current-voltage, temperature-current characteristics, dissipation constant, response and recovery time of the heater are reported. The maximum current handling capacity of the prepared thick film thermistor was observed at 300 mA and the temperature achieved to 340°C. Therefore, the heater was tested at a constant current of 300 mA for 24 h, which did not show any extreme change in behaviour and the temperature of the thermistor/ heater remained constant to 340 ± 5°C.

Soft state protocols use periodic refresh messages to keep the network state alive while adapting to changing network conditions; this has raised concerns regarding the scalability of protocols that use the soft state approach. In existing soft state protocols, the values of the timers that control the sending of these messages, and the timers for aging out state, are chosen by matching empirical observations with desired recovery and response times. These fixed timer-values fail because they use time as a metric for bandwidth; they adapt neither to (1) the wide range of link speeds that exist in most wide-area internets, nor to (2) fluctuations in the amount of network state over time. We propose and evaluate a new approach in which timer-values adapt dynamically to the volume of control traffic and available bandwidth on the link. The essential mechanisms required to realize this scalable timers approach are: (1) dynamic adjustment of the senders' refresh rate so that the bandwidth allocated for control traffic is not exceeded, and (2) estimation of the senders' refresh rate at the receiver in order to determine when the state can be timed-out and deleted. The refresh messages are sent in a round robin manner not exceeding the bandwidth allocated to the control traffic, and taking into account the message priorities. We evaluate two receiver estimation methods for dynamically adjusting network state timeout values: (1) counting of the rounds and (2) exponential weighted moving average

Soft state protocols use periodic refresh messages to keep network state alive while adapting to changing network conditions; this has raised concerns regarding the scalability of protocols that use the soft-state approach. In existing soft state protocols, the values of the timers that control the sending of these messages, and the timers for aging out state, are chosen by matching empirical observations with desired recovery and response times. These fixed timer-values fail because they use time as a metric for bandwidth; they adapt neither to (1) the wide range of link speeds that exist in most wide-area internets, nor to (2) fluctuations in the amount of network state over time.

Soft state protocols use periodic refresh messages to keep the network state alive while adapting to changing network conditions; this has raised concerns regarding the scalability of protocols that use the soft state approach. In existing soft state protocols, the values of the timers that control the sending of these messages, and the timers for aging out state, are chosen by matching empirical observations with desired recovery and response times. These fixed timer-values fail because they use time as a metric for bandwidth; they adapt neither to (1) the wide range of link speeds that exist in most wide-area internets, nor to (2) fluctuations in the amount of network state over time. We propose and evaluate a new approach in which timer-values adapt dynamically to the volume of control traffic and available bandwidth on the link. The essential mechanisms required to realize this scalable timers approach are: (1) dynamic adjustment of the senders' refresh rate so that the bandwidth allocated for control traffic is not exceeded, and (2) estimation of the senders' refresh rate at the receiver in order to determine when the state can be timed-out and deleted. The refresh messages are sent in a round robin manner not exceeding the bandwidth allocated to the control traffic, and taking into account the message priorities. We evaluate two receiver estimation methods for dynamically adjusting network state timeout values: (1) counting of the rounds and (2) exponential weighted moving average

ABSTRACT We used two different techniques to measure the recovery time of Photosystem II following the transfer of a single electron from P-680 to QA in thylakoid membranes isolated from spinach. Electron transfer in Photosystem II reaction centers was probed first by spectroscopic measurements of the electrochromic shift at 518 nm due to charge separation within the reaction centers. Using two short actinic flashes separated by a variable time interval we determined the time required after the first flash for the electrochromic shift at 518 nm to recover to the full extent on the second flash. In the second technique the redox state of QA at variable times after a saturating flash was monitored by measurement of the fluorescence induction in the absence of an inhibitor and in the presence of ferricyanide. The objective was to determine the time required after the actinic flash for the fluorescence induction to recover to the value observed after a 60 s dark period. Measurements were done under conditions in which (1) the electron donor for Photosystem II was water and the acceptor was the endogenous plastoquinone pool, and (2) Q400, the Fe2+ near QA, remained reduced and therefore was not a participant in the flash-induced electron-transfer reactions. The electrochromic shift at 518 nm and the fluorescence induction revealed a prominent biphasic recovery time for Photosystem II reaction centers. The majority of the Photosystem II reaction centers recovered in less than 50 ms. However, approx. one-third of the Photosystem II reaction centers required a half-time of 2–3 s to recover. Our interpretation of these data is that Photosystem II reaction centers consist of at least two distinct populations. One population, typically 68% of the total amount of Photosystem II as determined by the electrochromic shift, has a steady-state turnover rate for the electron-transfer reaction from water to the plastoquinone pool of approx. 250 e− / s, sufficiently rapid to account for measured rates of steady-state electron transport. The other population, typically 32%, has a turnover rate of approx. 0.2 e− / s. Since this turnover rate is over 1000-times slower than normally active Photosystem II complexes, we conclude that the slowly turning over Photosystem II complexes are inconsequential in contributing to energy transduction. The slowly turning over Photosystem II complexes are able to transfer an electron from P-680 to QA rapidly, but the reoxidation of Q−A is slow (). The fluorescence induction measurements lead us to conclude that there is significant overlap between the slowly turning over fraction of Photosystem II complexes and PS IIβ reaction centers. One corollary of this conclusion is that electron transfer from P-680 to QA in PS IIβ reaction centers results in charge separation across the membrane and gives rise to an electrochromic shift.