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306
result(s) for
"recovery delay"
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Network topology and recovery delay thresholds determine cascading failure vulnerability in sports systems
2026
Network topology fundamentally determines how cascading failures propagate through sports systems, yet the risk thresholds governing this relationship remain unquantified. We developed a network-agent model comparing four structural configurations through failure propagation dynamics, protection strategies, and recovery mechanisms across random, regular, small-world, and scale-free networks. Scale-free structures, characteristic of star-player dependent teams, exhibit 57% higher vulnerability than regular counterparts, with a Network Vulnerability Index of 1.24 versus 0.79. Immediate recovery interventions (
) effectively prevent cascading failures, while delayed responses (
) trigger exponential propagation. Phase space analysis reveals distinct stability basins, with scale-free configurations occupying the largest failure-dominant region at 43% of the phase space. Empirical validation against professional injury cascade records and international league shutdown data confirms strong agreement between model predictions and observed outcomes, with leagues implementing immediate interventions recovering 26.9% faster. These findings establish quantitative thresholds for topology-aware management strategies to mitigate cascading failures in professional sports.
Journal Article
Transient analysis of computing system with reboot and recovery delay
2020
PurposeThe purpose of this paper is to present a sensitivity analysis of fault-tolerant redundant repairable computing systems with imperfect coverage, reboot and recovery process.Design/methodology/approachIn this investigation, the authors consider the computing system having a finite number of identical working units functioning simultaneously with the provision of standby units. Working and standby units are prone to random failure in nature and are administered by unreliable software, which is also likely to unpredictable failure. The redundant repairable computing system is modeled as a Markovian machine interference problem with exponentially distributed failure rates and service rates. To excerpt the failed unit from the computing system, the system either opts randomized reboot process or leads to recovery delay.FindingsTransient-state probabilities have been determined with which the authors develop various reliability measures, namely reliability/availability, mean time to failure, failure frequency, and so on, and queueing characteristics, namely expected number of failed units, the throughput of the system and so on, for the predictive purpose. To spectacle the practicability of the developed model, a numerical simulation, sensitivity analysis and so on for different parameters have also been done, and the results are summarized in the tables and graphs. The transient results are helpful to analyze the developing model of the system before having the stability of the system. The derived measures give direct insights into parametric decision-making.Social implicationsThe conclusion has been drawn, and future scope is remarked. The present research study would help system analyst and system designer to make a better choice/decision in order to have the economical design and strategy based on the desired mean time to failure, reliability/availability of the systems and other queueing characteristics.Originality/valueDifferent from previous investigations, this studied model provides a more accurate assessment of the computing system compared to uncertain environments based on sensitivity analysis.
Journal Article
Delay recovery model for high-speed trains with compressed train dwell time and running time
2020
Modeling the application of train operation adjustment actions to recover from delays is of great importance to supporting the decision-making of dispatchers. In this study, the effects of two train operation adjustment actions on train delay recovery were explored using train operation records from scheduled and actual train timetables. First, the modeling data were sorted to extract the possible influencing factors under two typical train operation adjustment actions, namely the compression of the train dwell time at stations and the compression of the train running time in sections. Stepwise regression methods were then employed to determine the importance of the influencing factors corresponding to the train delay recovery time, namely the delay time, the scheduled supplement time, the running interval, the occurrence time, and the place where the delay occurred, under the two train operation adjustment actions. Finally, the gradient-boosted regression tree (GBRT) algorithm was applied to construct a delay recovery model to predict the delay recovery effects of the train operation adjustment actions. A comparison of the prediction results of the GBRT model with those of a random forest model confirmed the better performance of the GBRT prediction model.
Journal Article
Factors associated with recovery delay in a sample of patients diagnosed by MERS‐CoV rRT‐PCR: A Saudi Arabian multicenter retrospective study
2018
Background Research evidence exists that poor prognosis is common in Middle East respiratory syndrome coronavirus (MERS‐CoV) patients. Objectives This study estimates recovery delay intervals and identifies associated factors in a sample of Saudi Arabian patients admitted for suspected MERS‐CoV and diagnosed by rRT‐PCR assay. Methods A multicenter retrospective study was conducted on 829 patients admitted between September 2012 and June 2016 and diagnosed by rRT‐PCR procedures to have MERS‐CoV and non‐MERS‐CoV infection in which 396 achieved recovery. Detailed medical charts were reviewed for each patient who achieved recovery. Time intervals in days were calculated from presentation to the initial rRT‐PCR diagnosis (diagnosis delay) and from the initial rRT‐PCR diagnosis to recovery (recovery delay). Results The median recovery delay in our sample was 5 days. According to the multivariate negative binomial model, elderly (age ≥ 65), MERS‐CoV infection, ICU admission, and abnormal radiology findings were associated with longer recovery delay (adjusted relative risk (aRR): 1.741, 2.138, 2.048, and 1.473, respectively). Camel contact and the presence of respiratory symptoms at presentation were associated with a shorter recovery delay (expedited recovery) (aRR: 0.267 and 0.537, respectively). Diagnosis delay is a positive predictor for recovery delay (r = .421; P = .001). Conclusions The study evidence supports that longer recovery delay was seen in patients of older age, MERS‐CoV infection, ICU admission, and abnormal radiology findings. Shorter recovery delay was found in patients who had camel contact and respiratory symptoms at presentation. These findings may help us understand clinical decision making on directing hospital resources toward prompt screening, monitoring, and implementing clinical recovery and treatment strategies.
Journal Article
Peripheral Nerve Injuries: Electrophysiology for the Neurosurgeon
by
Kamble, Nitish
,
Shukla, Dhaval
,
Bhat, Dhananjay
in
Classification
,
Electrodes
,
Electromyography
2019
Peripheral nerve injuries are a heterogeneous and distinct group of disorders that are secondary to various causes commonly including motor vehicle accidents, falls, industrial accidents, household accidents, and penetrating trauma. The earliest classification of nerve injuries was given by Seddon and Sunderland, which holds true till date and is commonly used. Neuropraxia, axonotmesis, and neurotmesis are the three main types of nerve injuries. The electrophysiological studies including nerve conduction studies (NCS) and electromyography (EMG) play a key role and are now considered an extension of the clinical examination in patients with peripheral nerve injuries. The electrophysiological results should be interpreted in the light of clinical examination. These studies help in localizing the site of lesion, determine the type and severity of lesion, and help in prognosticating. In neuropraxia, the compound muscle action potential (CMAP) and sensory nerve action potential (SNAP) are elicitable on stimulating the nerve distal to the site of the lesion but demonstrate conduction block on proximal stimulation. The electrodiagnostic findings in axonotmesis and neurotmesis are similar. After few days of injury, Wallerian degeneration sets in with failure to record CMAP and SNAP. Intraoperative technique involves recording from the peripheral nerves during the intraoperative period and has proved useful in the surgical management of nerve injuries and helps in identifying the injured nerve, to determine whether the nerve is in continuity and in localizing the site of lesion. Intraoperative monitoring also helps in identifying the nerve close to an ongoing surgery so that surgical damage to the nerve can be prevented.
Journal Article
Project ambidexterity: case of recovering schedule delay in a brownfield airport project in India
by
Iyer, K. Chandrashekhar
,
Banerjee, Partha S.
in
Airport construction
,
airport construction project
,
Airport expansion
2016
Planning deficiencies and consequent execution delays are likely to persist in infrastructure development projects. However, recovery of schedule delay is a less researched area. This case research, using a two-stage inquiry modeled on the grounded theory, studied the schedule delay recovery during the execution phase of a brownfield airport construction project. The analyses generated contextual evidence and ambidexterity was found to be the key underlying phenomenon for successful recovery measures. The empirical learning was validated with literature and can be used by practitioners looking to institute schedule recovery measures.
Journal Article
Understanding long‐term effects of topsoil removal in peatlands: overcoming thresholds for fen meadows restoration
by
van der Elst, David J.D.
,
Grootjans, Albert P.
,
Klimkowska, Agata
in
Acidification
,
Base saturation
,
Community composition
2015
QUESTIONS: What are the long‐term results of fen meadow restoration after topsoil removal on peatlands? What are the causes of slow fen‐meadow vegetation recovery on peat soils after topsoil removal? LOCATION: Drentsche Aa Nature Reserve (53°00′49″N, 6°37′46″E) in the northeast Netherlands, with extensive natural and partially restored fen meadows (ca. 10,000 ha). METHODS: Restoration measures consisted of removal of acidified and fertilized topsoil and improvement of local hydrology by blocking or removing drainage ditches. The effects of shallow (20 cm) and deep (40 cm) topsoil removal were compared. We monitored vegetation changes after restoration measures in permanent plots over a 13‐yr period, and analysed changes in species composition over time with ordination techniques (multivariate analysis: PCA and RDA). Soil conditions over time were analysed using repeated measures ANOVA. RESULTS: The vegetation and environment shifted over time in response to restoration. At first the vegetation stagnated in a species‐poor phase for 5 yr, but eventually fen‐meadow species re‐established. At the end of the observation period, after 14 yr, the vegetation after both shallow and deep peat removal was similar. Soil acidification occurred immediately after topsoil removal (within the first 2–3 yr) due to pyrite oxidation when the soil was exposed to air after site excavation and the peat was temporarily desiccated. CONCLUSIONS: We found poor re‐establishment of fen‐meadow vegetation and persistence of species‐poor communities during the first 5 yr after topsoil removal, probably resulting from internal soil acidification. After further rewetting, a rapid shift towards the target community composition was observed. The positive shift in development of fen‐meadow vegetation probably occurred due to increased groundwater discharge after successful hydrological measures were applied. Appropriate hydrological conditions (strong discharge of groundwater) are important for the success of restoration of these fen meadows, especially if pyrite is present in shallow soil layers.
Journal Article
Design of a delay locked loop with low power and high operating frequency range characteristics in 180-nm CMOS process
by
Anisheh, Seyed Mahmoud
,
Ghorbani, Alireza
,
Saraji, Fatemeh Esmaili
in
Charge pumps
,
Circuits
,
Circuits and Systems
2024
A delay lock loop is a key element in circuits such as clock synchronization, clock and data clock recovery. In this paper, new structures for phase frequency detector (PFD), charge pump (CP) and delay cell for low power applications are presented. A dynamic PFD based on a CMOS inverter is proposed which has low power consumption and its operating frequency range is wide. The proposed CP is based on gate-driven and positive feedback techniques with good current matching. The delay cell uses the bulk-driven technique and has less power consumption than the conventional structure. To assess the performance of the proposed structures, some simulations are performed in a 0.18 μm CMOS process with a supply voltage of 1.8 V. The simulation results show higher efficiency of the proposed structures than the existing structures in terms of accuracy and power consumption. The simulation results show that the maximum operating frequency of the PFD is 2 GHz. The mismatch between up and down currents of the CP is less than 0.3%. The power consumption of the proposed delay cell is 25% less than the conventional structure.
Journal Article
Effect of Delayed Peripheral Nerve Repair on Nerve Regeneration, Schwann Cell Function and Target Muscle Recovery
2013
Despite advances in surgical techniques for peripheral nerve repair, functional restitution remains incomplete. The timing of surgery is one factor influencing the extent of recovery but it is not yet clearly defined how long a delay may be tolerated before repair becomes futile. In this study, rats underwent sciatic nerve transection before immediate (0) or 1, 3, or 6 months delayed repair with a nerve graft. Regeneration of spinal motoneurons, 13 weeks after nerve repair, was assessed using retrograde labeling. Nerve tissue was also collected from the proximal and distal stumps and from the nerve graft, together with the medial gastrocnemius (MG) muscles. A dramatic decline in the number of regenerating motoneurons and myelinated axons in the distal nerve stump was observed in the 3- and 6-months delayed groups. After 3 months delay, the axonal number in the proximal stump increased 2-3 folds, accompanied by a smaller axonal area. RT-PCR of distal nerve segments revealed a decline in Schwann cells (SC) markers, most notably in the 3 and 6 month delayed repair samples. There was also a progressive increase in fibrosis and proteoglycan scar markers in the distal nerve with increased delayed repair time. The yield of SC isolated from the distal nerve segments progressively fell with increased delay in repair time but cultured SC from all groups proliferated at similar rates. MG muscle at 3- and 6-months delay repair showed a significant decline in weight (61% and 27% compared with contra-lateral side). Muscle fiber atrophy and changes to neuromuscular junctions were observed with increased delayed repair time suggestive of progressively impaired reinnervation. This study demonstrates that one of the main limiting factors for nerve regeneration after delayed repair is the distal stump. The critical time point after which the outcome of regeneration becomes too poor appears to be 3-months.
Journal Article
A 2–20 Gbps Clock and Data Recovery Based on Phase Interpolation and Delay Locked Loop
2024
This paper presents a low-power multi-rate clock and data recovery (CDR) for receivers of serial links. Its basic structure includes a current-mode logic bang–bang phase detector sampled by low-mismatch half-rate quadrature clocks, which are generated by voltage-controlled delay line (VCDL) and two-stage time-average circuits. The total delay of VCDL can be adjusted to accommodate a wide frequency range by its bias voltage, which is generated by a delay-locked-loop-based bias generator. The quadrature clocks are 64-phase adjustable with high linearity, which is realized by phase interpolator with a compensating structure. The parameters of phase detection loop are well designed to satisfy both high jitter tolerance and low clock jitter. Fabricated in a 40 nm CMOS technology, the CDR occupies an active area of 0.036 mm
2
only. With a wide operating range of 2–20 Gb/s, the chip consumes 62.5 mW, corresponding to an energy efficiency of 3.1 pJ/bit. The measured root-mean-square jitter and peak-to-peak jitter for the recovered clock at 9 GHz are 1.9 and 10.8 ps, respectively.
Journal Article