Precedent-free fault isolation in a diesel engine exhaust gas recirculation system

In this paper, a recently introduced model-based method for precedent-free fault detection and isolation (FDI) is modified to deal with multiple input, multiple output (MIMO) systems and is applied to an automotive engine with exhaust gas recirculation (EGR) system. Using normal behavior data generated by a high fidelity engine simulation, the growing structure multiple model system (GSMMS) approach is used to construct dynamic models of normal behavior for the EGR system and its constituent subsystems. Using the GSMMS models as a foundation, anomalous behavior is detected whenever statistically significant departures of the most recent modeling residuals away from the modeling residuals displayed during normal behavior are observed. By reconnecting the anomaly detectors (ADs) to the constituent subsystems, EGR valve, cooler, and valve controller faults are isolated without the need for prior training using data corresponding to particular faulty system behaviors.

Timing and distribution of protein ingestion during prolonged recovery from resistance exercise alters myofibrillar protein synthesis

Quantity and timing of protein ingestion are major factors regulating myofibrillar protein synthesis (MPS). However, the effect of specific ingestion patterns on MPS throughout a 12 h period is unknown. We determined how different distributions of protein feeding during 12 h recovery after resistance exercise affects anabolic responses in skeletal muscle. Twenty-four healthy trained males were assigned to three groups (n = 8/group) and undertook a bout of resistance exercise followed by ingestion of 80 g of whey protein throughout 12 h recovery in one of the following protocols: 8 × 10 g every 1.5 h (PULSE); 4 × 20 g every 3 h (intermediate: INT); or 2 × 40 g every 6 h (BOLUS). Muscle biopsies were obtained at rest and after 1, 4, 6, 7 and 12 h post exercise. Resting and post-exercise MPS (l-[ring-(13)C6] phenylalanine), and muscle mRNA abundance and cell signalling were assessed. All ingestion protocols increased MPS above rest throughout 1-12 h recovery (88-148%, P < 0.02), but INT elicited greater MPS than PULSE and BOLUS (31-48%, P < 0.02). In general signalling showed a BOLUS>INT>PULSE hierarchy in magnitude of phosphorylation. MuRF-1 and SLC38A2 mRNA were differentially expressed with BOLUS. In conclusion, 20 g of whey protein consumed every 3 h was superior to either PULSE or BOLUS feeding patterns for stimulating MPS throughout the day. This study provides novel information on the effect of modulating the distribution of protein intake on anabolic responses in skeletal muscle and has the potential to maximize outcomes of resistance training for attaining peak muscle mass.

The recovery concept and crisis intervention : time for a revolution in the realm of acute psychiatric care

“Mental illness is a tough illness to survive, it is incurable but manageable. Living with the illness when at its full potency can disrupt your life at any moment.” Intensive care for patients experiencing acute psychiatric distress is an essential yet complex part of mental health services as a whole system. Psychiatric intensive care units remain a source of controversy; despite promising developments to health services incorporating recovery goals and processes outlined by people with a mental illness themselves. In past decades changes in the provision of mental health services have focused on the restoration of a meaningful and empowered life with choice and hope as a defining attribute of recovery. Yet, what does recovery mean and how are recovery principles accomplished in psychiatric intensive care arrangements for someone experiencing acute psychiatric distress?

Effect of recovery modality on 4-hour repeated treadmill running performance and changes in physiological variables

The purpose of this study was to compare the effectiveness of three different recovery modalities - active (ACT), passive (PAS) and contrast temperature water immersion (CTW) - on the performance of repeated treadmill running, lactate concentration and pH. Fourteen males performed two pairs of treadmill runs to exhaustion at 120% and 90% of peak running speed (PRS) over a 4-hour period. ACT, PAS or CTW was performed for 15-min after the first pair of treadmill runs. ACT consisted of running at 40% PRS, PAS consisted of standing stationary and CTW consisted of alternating between 60-s cold (10°C) and 120-s hot (42°C) water immersion. Run times were converted to time to cover set distance using critical power. Type of recovery modality did not have a significant effect on change in time to cover 400 m (Mean±SD; ACT 2.7±3.6 s, PAS 2.9±4.2 s, CTW 4.2±6.9 s), 1000 m (ACT 2.2±4.0 s, PAS 4.8±8.6 s, CTW 2.1±7.2 s) or 5000 m (ACT 1.4±29.0 s, PAS 16.7±58.5 s, CTW 11.7±33.0 s). Post exercise blood lactate concentration was lower in ACT and CTW compared with PAS. Participants reported an increased perception of recovery in the CTW compared with ACT and PAS. Blood pH was not significantly influenced by recovery modality. Data suggest both ACT and CTW reduce lactate accumulation after high intensity running, but high intensity treadmill running performance is returned to baseline 4-hours after the initial exercise bout regardless of the recovery strategy employed.

Time course-dependent changes in the transcriptome of human skeletal muscle during recovery from endurance exercise: From inflammation to adaptive remodeling

Re-programming of gene expression is fundamental for skeletal muscle adaptations in response to endurance exercise. This study investigated the time-course dependent changes in the muscular transcriptome following an endurance exercise trial consisting of 1 h of intense cycling immediately followed by 1 h of intense running. Skeletal muscle samples were taken at baseline, 3 h, 48 h, and 96 h post-exercise from eight healthy, endurance-trained, male individuals. RNA was extracted from muscle. Differential gene expression was evaluated using Illumina microarrays and validated with qPCR. Gene set enrichment analysis identified enriched molecular signatures chosen from the Molecular Signatures Database. Three h post-exercise, 102 gene sets were up-regulated [family wise error rate (FWER), P < 0.05]; including groups of genes related with leukocyte migration, immune and chaperone activation, and cyclic AMP responsive element binding protein (CREB) 1-signaling. Forty-eight h post-exercise, among 19 enriched gene sets (FWER, P < 0.05), two gene sets related to actin cytoskeleton remodeling were up-regulated. Ninety-six h post-exercise, 83 gene sets were enriched (FWER, P < 0.05), 80 of which were up-regulated; including gene groups related to chemokine signaling, cell stress management, and extracellular matrix remodeling. These data provide comprehensive insights into the molecular pathways involved in acute stress, recovery, and adaptive muscular responses to endurance exercise. The novel 96 h post-exercise transcriptome indicates substantial transcriptional activity, potentially associated with the prolonged presence of leukocytes in the muscles. This suggests that muscular recovery, from a transcriptional perspective, is incomplete 96 h after endurance exercise involving muscle damage.

Recovery of transverse strain in high–stress tendons following exercise

Background. This study evaluated the time course of recovery of transverse strain in the Achilles and patellar tendons following a bout of resistance exercise. Methods. Seventeen healthy adults underwent sonographic examination of the right patellar (n = 9) or Achilles (n = 8) tendons immediately prior to and following 90 repetitions of weight–bearing exercise. Quadriceps and gastrocnemius exercise were performed against an effective resistance of 175% and 250% body weight, respectively. Sagittal tendon thickness was determined 20 mm from the tendon enthesis and transverse strain was repeatedly monitored over a 24 hour recovery period. Results. Resistance exercise resulted in an immediate decrease in Achilles (t7 = 10.6, P<.01) and patellar (t8 = 8.9, P<.01) tendon thickness, resulting in an average transverse strain of 0.14 ± 0.04 and 0.18 ± 0.05. While the average strain was not significantly different between tendons, older age was associated with a reduced transverse strain response (r=0.63, P<.01). Recovery of transverse strain, in contrast, was prolonged compared with the duration of loading and exponential in nature. The mean primary recovery time was not significantly different between Achilles (6.5 ± 3.2 hours) and patellar (7.1 ± 3.2 hours) tendons and body weight accounted for 62% and 64% of the variation in recovery time, respectively. Discussion. Despite structural and biochemical differences between the Achilles and patellar tendons [1], the mechanisms underlying transverse creep–recovery in vivo appear similar and are highly time dependent. Primary recovery required about 7 hours in healthy tendons, with full recovery requiring up to 24 hours. These in vivo recovery times are similar to those reported for axial creep recovery of the vertebral disc in vitro [2], and may be used clinically to guide physical activity to rest ratios in healthy adults. Optimal ratios for high–stress tendons in clinical populations, however, remain unknown and require further attention in light of the knowledge gained in this study.

Fault symptoms of rolling element bearings under variable operating conditions - a multi domain analysis

Diagnostics of rolling element bearings have been traditionally developed for constant operating conditions, and sophisticated techniques, like Spectral Kurtosis or Envelope Analysis, have proven their effectiveness by means of experimental tests, mainly conducted in small-scale laboratory test-rigs. Algorithms have been developed for the digital signal processing of data collected at constant speed and bearing load, with a few exceptions, allowing only small fluctuations of these quantities. Owing to the spreading of condition based maintenance in many industrial fields, in the last years a need for more flexible algorithms emerged, asking for compatibility with highly variable operating conditions, such as acceleration/deceleration transients. This paper analyzes the problems related with significant speed and load variability, discussing in detail the effect that they have on bearing damage symptoms, and propose solutions to adapt existing algorithms to cope with this new challenge. In particular, the paper will i) discuss the implication of variable speed on the applicability of diagnostic techniques, ii) address quantitatively the effects of load on the characteristic frequencies of damaged bearings and iii) finally present a new approach for bearing diagnostics in variable conditions, based on envelope analysis. The research is based on experimental data obtained by using artificially damaged bearings installed on a full scale test-rig, equipped with actual train traction system and reproducing the operation on a real track, including all the environmental noise, owing to track irregularity and electrical disturbances of such a harsh application.

Effectiveness of MED for Fault Diagnosis in Roller Bearings

Diagnostics of rolling element bearings is usually performed by means of vibration signals measured by accelerometers placed in the proximity of the bearing under investigation. The aim is to monitor the integrity of the bearing components, in order to avoid catastrophic failures, or to implement condition based maintenance strategies. In particular, the trend in this field is to combine in a single algorithm different signal-enhancement and signal-analysis techniques. Among the first ones, Minimum Entropy Deconvolution (MED) has been pointed out as a key tool able to highlight the effect of a possible damage in one of the bearing components within the vibration signal. This paper presents the application of this technique to signals collected on a simple test-rig, able to test damaged industrial roller bearings in different working conditions. The effectiveness of the technique has been tested, comparing the results of one undamaged bearing with three bearings artificially damaged in different locations, namely on the inner race, outer race and rollers. Since MED performances are dependent on the filter length, the most suitable value of this parameter is defined on the basis of both the application and measured signals. This represents an original contribution of the paper.

Bearing Fault Diagnostics Using the Spectral Pattern Recognition

In the field of diagnostics of rolling element bearings, the development of sophisticated techniques, such as Spectral Kurtosis and 2nd Order Cyclostationarity, extended the capability of expert users to identify not only the presence, but also the location of the damage in the bearing. Most of the signal-analysis methods, as the ones previously mentioned, result in a spectrum-like diagram that presents line frequencies or peaks in the neighbourhood of some theoretical characteristic frequencies, in case of damage. These frequencies depend only on damage position, bearing geometry and rotational speed. The major improvement in this field would be the development of algorithms with high degree of automation. This paper aims at this important objective, by discussing for the first time how these peaks can draw away from the theoretical expected frequencies as a function of different working conditions, i.e. speed, torque and lubrication. After providing a brief description of the peak-patterns associated with each type of damage, this paper shows the typical magnitudes of the deviations from the theoretical expected frequencies. The last part of the study presents some remarks about increasing the reliability of the automatic algorithm. The research is based on experimental data obtained by using artificially damaged bearings installed in a gearbox.

Is recovery driven by central or peripheral factors? A role for the brain in recovery following intermittent-sprint exercise

Prolonged intermittent-sprint exercise (i.e., team sports) induce disturbances in skeletal muscle structure and function that are associated with reduced contractile function, a cascade of inflammatory responses, perceptual soreness, and a delayed return to optimal physical performance. In this context, recovery from exercise-induced fatigue is traditionally treated from a peripheral viewpoint, with the regeneration of muscle physiology and other peripheral factors the target of recovery strategies. The direction of this research narrative on post-exercise recovery differs to the increasing emphasis on the complex interaction between both central and peripheral factors regulating exercise intensity during exercise performance. Given the role of the central nervous system (CNS) in motor-unit recruitment during exercise, it too may have an integral role in post-exercise recovery. Indeed, this hypothesis is indirectly supported by an apparent disconnect in time-course changes in physiological and biochemical markers resultant from exercise and the ensuing recovery of exercise performance. Equally, improvements in perceptual recovery, even withstanding the physiological state of recovery, may interact with both feed-forward/feed-back mechanisms to influence subsequent efforts. Considering the research interest afforded to recovery methodologies designed to hasten the return of homeostasis within the muscle, the limited focus on contributors to post-exercise recovery from CNS origins is somewhat surprising. Based on this context, the current review aims to outline the potential contributions of the brain to performance recovery after strenuous exercise.

Theory-based self-management programs for promoting recovery in community-dwelling stroke survivors : a systematic review

Background Post-stroke recovery is demanding. Increasing studies have examined the effectiveness of self-management programs for stroke survivors. However no systematic review has been conducted to summarize the effectiveness of theory-based stroke self-management programs. Objectives The aim is to present the best available research evidence about effectiveness of theory-based self-management programs on community-dwelling stroke survivors’ recovery. Inclusion criteria Types of participants All community-residing adults aged 18 years or above, and had a clinical diagnosis of stroke. Types of interventions Studies which examined effectiveness of a self-management program underpinned by a theoretical or conceptual framework for community-dwelling stroke survivors. Types of studies Randomized controlled trials. Types of outcomes Primary outcomes included health-related quality of life and self-management behaviors. Secondary outcomes included physical (activities of daily living), psychological (self-efficacy, depressive symptoms), and social outcomes (community reintegration, perceived social support). Search Strategy A three-step approach was adopted to identify all relevant published and unpublished studies in English or Chinese. Methodological quality The methodological quality of the included studies was assessed using the Joanna Briggs Institute critical appraisal checklist for experimental studies. Data Collection A standardized JBI data extraction form was used. There was no disagreement between the two reviewers on the data extraction results. Data Synthesis There were incomplete details about the number of participants and the results in two studies, which makes it impossible to perform meta-analysis. A narrative summary of the effectiveness of stroke self-management programs is presented. Results Three studies were included. The key issues of concern in methodological quality included insufficient information about random assignment, allocation concealment, reliability and validity of the measuring instruments, absence of intention-to-treat analysis, and small sample sizes. The three programs were designed based on the Stanford Chronic Disease Self-management program and were underpinned by the principles of self-efficacy. One study showed improvement in the intervention group in family and social roles three months after program completion, and work productivity at six months as measured by the Stroke Specific Quality of Life Scale (SSQOL). The intervention group also had an increased mean self-efficacy score in communicating with physicians six months after program completion. The mean changes from baseline in these variables were significantly different from the control group. No significant difference was found in time spent in aerobic exercise between the intervention and control groups at three and six months after program completion. Another study, using SSQOL, showed a significant interaction effect by treatment and time on family roles, fine motor tasks, self-care, and work productivity. However there was no significant interaction by treatment and time on self-efficacy. The third study showed improvement in quality of life, community participation, and depressive symptoms among the participants receiving the stroke self-management program, Stanford Chronic Disease Self-management program, or usual care six months after program completion. However, there was no significant difference between the groups. Conclusions There is inconclusive evidence about the effectiveness of theory-based stroke self-management programs on community-dwelling stroke survivors’ recovery. However the preliminary evidence suggests potential benefits in improving stroke survivors’ quality of life and self-efficacy.

Predicting fault-prone software modules with rank sum classification

The detection and correction of defects remains among the most time consuming and expensive aspects of software development. Extensive automated testing and code inspections may mitigate their effect, but some code fragments are necessarily more likely to be faulty than others, and automated identification of fault prone modules helps to focus testing and inspections, thus limiting wasted effort and potentially improving detection rates. However, software metrics data is often extremely noisy, with enormous imbalances in the size of the positive and negative classes. In this work, we present a new approach to predictive modelling of fault proneness in software modules, introducing a new feature representation to overcome some of these issues. This rank sum representation offers improved or at worst comparable performance to earlier approaches for standard data sets, and readily allows the user to choose an appropriate trade-off between precision and recall to optimise inspection effort to suit different testing environments. The method is evaluated using the NASA Metrics Data Program (MDP) data sets, and performance is compared with existing studies based on the Support Vector Machine (SVM) and Naïve Bayes (NB) Classifiers, and with our own comprehensive evaluation of these methods.

Health and safety for clean-up and recovery workers

This paper will identify and discuss the major occupational health and safety (OHS) hazards and risks for clean-up and recovery workers. The lessons learned from previous disasters including; the Exxon Valdez oil spill, World Trade Centre (WTC) terrorist attack, Hurricane Katrina and the Deepwater Horizon Gulf of Mexico oil spill will be discussed. The case for an increased level of preparation and planning to mitigate the health risks for clean-up and recovery workers will be presented, based on recurring themes identified in the peer reviewed literature. There are a number of important issues pertaining to the occupational health and safety of workers who are engaged in clean-up and recovery operations following natural and technological disasters. These workers are often exposed to a wide range of occupational health and safety hazards, some of which may be unknown at the time. It is well established that clean-up and recovery operations involve risks of physical injury, for example, from manual handling, mechanical equipment, extreme temperatures, slips, trips and falls. In addition to these well established physical injury risks there are now an increasing number of studies which highlight the risks of longer term or chronic health effects arising from clean-up and recovery work. In particular, follow up studies from the Exxon Valdez oil spill, Hurricane Katrina and the World Trade Centre (WTC) terrorism attack have documented the longer term health consequences of these events. These health effects include respiratory symptoms and musculoskeletal disorders, as well as post traumatic stress disorder (PTSD). In large scale operations many of those workers and supervisors involved have not had any specific occupational health and safety (OHS) training and may not have access to the necessary instruction, personal protective equipment or other appropriate equipment, this is especially true when volunteers are used to form part of the clean-up and recovery workforce. In general, first responders are better equipped and trained than clean-up and recovery workers and some of the training approaches used for the traditional first responders would be relevant for clean-up and recovery workers.

Strategies for rapid congestion recovery using ramp metering

This research investigated strategies for motorway congestion management from a different angle: that is, how to quickly recover motorway from congestion at the end of peak hours, given congestion cannot be eliminated due to excessive demand during the long peak hours nowadays. The project developed a zone recovery strategy using ramp metering for rapid congestion recovery, and a serious of traffic simulation investigations were included to evaluate the developed strategy. The results, from both microscopic and macroscopic simulation, demonstrated the effectiveness of the zone recovery strategy.