Maintenance Related Activities Research Articles

Biostimulants for Sustainable Management of Sport Turfgrass.

Research on the efficacy of innovative, ecofriendly biostimulants in sport turf management is scarce, with less information available from open-field experiments, and even less pertaining to thatch control-related problems. The objective was to investigate the open-field effectiveness of a commercial product, EM-1, and two newly developed products, ExpA and ExpB, in improving both rhizosphere and turfgrass, Agrostis stoloniferous L., characteristics on a golf green. ExpA and ExpB, identical in microbial composition, were equally effective in significantly increasing chlorophyll synthesis and visual turf quality, as well as in resistance to tearing out, compared to the untreated control 56 days after treatment (DAT). EM-1 showed intermediate trends between the control and novel biostimulants. The inclusion of humic acids and mycorrhizal fungi to the microbial composition in ExpB significantly improved some rhizosphere properties 56 DAT relative to the control. Results on ExpB evidenced a significant decrease in the thatch layer thickness and fresh leaf weight, associated with a significant increase in the humus thickness, organic matter decomposition and evapotranspiration efficiency. An increased dry leaf biomass was also shown. ExpA and EM-1 showed either marginal or intermediate improvements relative to the control. ExpB represents a promising alternative to alleviate negative environmental impacts associated with turf maintenance-related activities.

Valuation of inter-boundary inefficiencies accounting IoT based monitoring system in processed food supply chain

Nowadays, demand for processed food items is escalating towards the record consumption volume, which resulted in the surging of the Food Supply Chain (FSCs) network. But, the flow of the commodities through the various channels of the FSC is hampered by the various inefficiencies, which persist due to a lack of monitoring. This results in the widening of the gap between the supply and demand patterns allied with it. To tackle the same, and cater to the upwelling shares of the consumer demand, the dynamics of the Food Supply Chain Performance System (FSCPS) need to be tuned with the avenues of Industry 4.0 practices. Presented work clusters the various attributes of the inefficiencies, which hampers the processed FSCs dynamics and maintenance-related activities, elaborated by their sub-attributes based upon their events of occurrences. A model comprising the various attributes and sub-attributes of inefficiencies constrained outside the organizational boundaries of a firm’s FSC is rendered in this study. For effective handling of the mutual interdependencies persisting between the attributes, the methodology of the Graph Theory and Matrix Approach (GTMA) is exercised for the analysis of the developed model. Outcomes of the presented work felicitate the managers of industries, its allied corporates and numerous stakeholders of the FSC to ground a robust decisional framework, governing policies and managing the process permutations.

A method to assess the value of monitoring an SHM system

Abstract Aging structural components, together with the increasing transportation needs and limited budgets, are challenging aspects that typically concern decision-makers and infrastructure owners. Although Structural Health Monitoring (SHM) has been a powerful tool to optimize maintenance-related activities and post-disaster emergency management, the sensor readout and, therefore, the outcome of the monitoring system is susceptible to errors due to malfunctioning. For years, the Value of Information (VoI) has been studied to quantify the long- term benefit of SHM systems against the initial investment in sensing instrumentation without considering the eventuality of faulty sensing nodes. However, these are very common in field applications. This paper proposes a new framework to calculate the benefit of using Sensor Validation Tools (SVTs) before calculating the damage-sensitive features that drive the SHM process. The novel approach extends the traditional Vol to consider multiple “health” states of the SHM system, associate the outcome of the SHM system with the state of both the structure and the SHM system, and quantify the additional value obtained from SVTs.

ICT and Digital Technology based Solutions for Smart City Challenges and Opportunities

Purpose: Today's Smart Cities are rapidly evolving with the help of the latest tools and technologies and also due to large investment and priority focus by various countries across the globe. Smart Cities while growing also consider the environmental aspects such as producing lower carbon footprint, lower harmful gas emissions, and lower consumption of power. Abiding by this new paradigm, various Smart Cities started focusing on continuous improvement and innovation in their different services. Many Smart Cities have their own pain points such as traffic congestion, water scarcity, energy deficiency, waste management, poor participation of citizens in city administration, maintenance of complex IT Infrastructure, and so on. Such kind of issues may differ in scale and type but mostly common across geographies. While developing, operating, and maintaining Smart Cities, it is necessary to identify the most pressing and urgent issues that Smart City solutions must tackle on priority. In such cases, high-end technologies and tools can help to focus and eliminate the problems. In this paper, we analysed key challenges faced by Smart Cities during the development, operation, and maintenance related activities of various Smart Services and how these challenges and issues are effectively addressed by some of the key technologies with special attention to ICT and digital technologies. We have also reviewed some selected research papers devoted to Smart Cities challenges ad issues and how these issues are addressed using the latest tools and technologies. Finally, we have also specified the future plans about the discussed technical solutions to undertake its full-fledged implementation and addressing of its some of the limitations. Design/Methodology/Approach: This paper is based on the primary data collected while preparing research papers written by us on Smart Cities and a systematic literature review of existing literature including journal research papers, book chapters, dedicated websites, and white papers. Findings/Result: Smart Cities various operational and development challenges are effectively get addressed using various ICT and digital technologies. Some of the key technologies that played an important role in addressing some of the key concerns of Smart Cities include IoT, AI and ML, Blockchain, Data Analytics, Digital Twin, 5G, and Cloud Computing. Originality/Value: The Information presented in this paper is genuine and original and based on own research, data collected from industry professionals, systematic literature review of existing relevant research papers, and relevant data analysis and findings. Most of the information presented in this paper is derived from our own research papers written on Smart City services and solutions. Paper Type: Technology oriented Research

Upper-Limb Prosthetic Maintenance Data: A Retrospective Analysis Study

ABSTRACT Introduction Understanding repair patterns of upper-limb (UL) prosthetic devices have received little attention compared with their lower-limb counterparts. This study focuses on a retrospective analysis of anonymized UL prosthetic maintenance data to establish if there were any patterns of repairs at a regional prosthetic limb-fitting center in the United Kingdom. A secondary aim of this study is to describe the patient demographics of this center. Methods Data containing prosthetic repair log and demographic description (n = 212) were acquired through our clinical partners and subjected to statistical analyses. Results On average, each client visited the center 0.2 times/year for a new device and 0.9 times/year for maintenance-related activities. It is found that the repair rates are generally higher for body-powered devices (1.28 visits/device per year) compared with passive (0.94 visits/device per year) and externally powered devices (0.90 visits/device per year). In keeping with the typical UK UL-deficient population, there is a high male-to-female ratio, and higher instances of traumatic amputations were noticed for males at the center. There is a very high preponderance of congenital cases and an overall emphasis on prescribing passive devices to a majority of patients at the center. Conclusions The data from our study are similar to previously published data from other centers and show a consistent pattern in terms of relative rates of maintenance attendances for different types of UL prostheses. Clinical Relevance This study provides a longitudinal perspective and insights on ever-changing requirements (prostheses and related care) of the users at the level of a regional limb-fitting center. This study underscores current gaps in prosthetic device durability/reliability and opens up avenues for improvement of prosthetic services and devices.

Brain Correlates of Verbal Working Memory in Children with Hearing Loss: Auditory Experience Matters

Brain Correlates of Verbal Working Memory in Children with Hearing Loss: Auditory Experience Matters

Amount of Hearing Aid Use Impacts Neural Oscillatory Dynamics Underlying Verbal Working Memory Processing for Children With Hearing Loss.

Objectives:Children with hearing loss (CHL) may exhibit spoken language delays and may also experience deficits in other cognitive domains including working memory. Consistent hearing aid use (i.e., more than 10 hours per day) ameliorates these language delays; however, the impact of hearing aid intervention on the neural dynamics serving working memory remains unknown. The objective of this study was to examine the association between the amount of hearing aid use and neural oscillatory activity during verbal working memory processing in children with mild-to-severe hearing loss.Design:Twenty-three CHL between 8 and 15 years-old performed a letter-based Sternberg working memory task during magnetoencephalography (MEG). Guardians also completed a questionnaire describing the participants’ daily hearing aid use. Each participant’s MEG data was coregistered to their structural MRI, epoched, and transformed into the time–frequency domain using complex demodulation. Significant oscillatory responses corresponding to working memory encoding and maintenance were independently imaged using beamforming. Finally, these whole-brain source images were correlated with the total number of hours of weekly hearing aid use, controlling for degree of hearing loss.Results:During the encoding period, hearing aid use negatively correlated with alpha-beta oscillatory activity in the bilateral occipital cortices and right precentral gyrus. In the occipital cortices, this relationship suggested that with greater hearing aid use, there was a larger suppression of occipital activity (i.e., more negative relative to baseline). In the precentral gyrus, greater hearing aid use was related to less synchronous activity (i.e., less positive relative to baseline). During the maintenance period, hearing aid use significantly correlated with alpha activity in the right prefrontal cortex, such that with greater hearing aid use, there was less right prefrontal maintenance-related activity (i.e., less positive relative to baseline).Conclusions:This study is the first to investigate the impact of hearing aid use on the neural dynamics that underlie working memory function. These data show robust relationships between the amount of hearing aid use and phase-specific neural patterns during working memory encoding and maintenance after controlling for degree of hearing loss. Furthermore, our data demonstrate that wearing hearing aids for more than ~8.5 hours/day may serve to normalize these neural patterns. This study also demonstrates the potential for neuroimaging to help determine the locus of variability in outcomes in CHL.

The impact of mild-to-severe hearing loss on the neural dynamics serving verbal working memory processing in children

Children with hearing loss (CHL) exhibit delays in language function relative to children with normal hearing (CNH). However, evidence on whether these delays extend into other cognitive domains such as working memory is mixed, with some studies showing decrements in CHL and others showing CHL performing at the level of CNH. Despite the growing literature investigating the impact of hearing loss on cognitive and language development, studies of the neural dynamics that underlie these cognitive processes are notably absent. This study sought to identify the oscillatory neural responses serving verbal working memory processing in CHL compared to CNH. To this end, participants with and without hearing loss performed a verbal working memory task during magnetoencephalography. Neural oscillatory responses associated with working memory encoding and maintenance were imaged separately, and these responses were statistically evaluated between CHL and CNH. While CHL performed as well on the task as CNH, CHL exhibited significantly elevated alpha–beta activity in the right frontal and precentral cortices during encoding relative to CNH. In contrast, CHL showed elevated alpha maintenance-related activity in the right precentral and parieto-occipital cortices. Crucially, right superior frontal encoding activity and right parieto-occipital maintenance activity correlated with language ability across groups. These data suggest that CHL may utilize compensatory right-hemispheric activity to achieve verbal working memory function at the level of CNH. Neural behavior in these regions may impact language function during crucial developmental ages.

A decision support tool for bi-objective risk-based maintenance scheduling of an LNG gas sweetening unit

PurposeThe purpose of this paper is to develop a decision support tool for risk-based maintenance scheduling for a large heavily equipped gas sweetening unit in a Liquefied Natural Gas (LNG) plant. Two conflicting objectives, i.e., total maintenance cost and the reliability, are considered in the tool. The tool is tested with the real plant data and suggests several Pareto-optimal schedules for a decision maker to choose from. The financial impacts are assessed.Design/methodology/approachA bi-objective scheduling optimization model is developed for maintenance scheduling using a risk-based framework. The model is developed integrating genetic algorithm and simulation-based optimization to find Pareto-optimal schedules. The model delivered true Pareto front optimal solutions for given plant-specific data. The two conflicting objectives: the minimization of total expenditures incurred on maintenance-related activities and improving the total reliability are considered.FindingsFor large and complex processing facilities such as LNG plant, a shutdown of facility generates a significant financial impact, resulting in millions of dollars in production loss. The developed risk-based equipment selection strategy helps to minimize such an event of production loss by generating a thorough maintenance strategy for inspection, repair, overhaul or replacement schedule of the unit without initiating the shutdown. The proposed model has been successfully applied to obtain an optimize maintenance schedule for a gas sweetening unit.Research limitations/implicationsA future work may consider the state-dependent models for various failure modes that will result in obtaining a better representation of the model. The proposed scheduling can further be extended to multi-criteria scheduling including availability, resource limitation and inflationary condition. A comparative analysis with other meta-heuristic techniques such as harmony search algorithm, tabu search, and simulated annealing will further help in confirming the schedule obtained from this application.Practical implicationsMaintenance scheduling using a conventional approach for special equipment generally does not consider the conflicting objectives. This research addresses this aspect using a bi-objective model. The usefulness of risk-based method is to assist in minimizing the financial and safety risk exposure to the operating companies, but some variation in results is expected due to varying risk matrix for different organizations.Social implicationsManaging two objectives, i.e., minimizing the cost of maintenance-related activities, while at the same time maximizing the overall reliability dramatically, helps in mitigating adverse safety and financial risk due to fires, explosions, fatality and excessive maintenance cost.Originality/valueResearch develops a decision support tool for managing conflicting objectives for an LNG process. This research highlights the impact of utilizing the simulation-based approach coupled with risk-based equipment selection for complex processing unit or plant maintenance scheduling optimization.

Security challenges for cloud-based email infrastructure

Over the past few years, the recognition and acceptance of cloud-based applications has gained a lot of momentum. Commercial applications that were initially installed inside corporate on-premises server rooms are now hosted on cloud infrastructures. Software applications are provided in the form of commercial services that are accessible anytime, anywhere. Cloud-based solutions also eliminate the need for regular maintenance-related activities, unnecessary downtimes or outages, attention to back-ups or regular infrastructure upgrades. Commercial applications that were initially installed inside corporate server rooms are now hosted on cloud infrastructures, accessible anytime, anywhere. However, mitigating cloud-based security risks requires that service providers and corporate users adopt a universal approach for ensuring that the right solution is in place, especially when application services used over insecure Internet connections raise new risks. Akashdeep Bhardwaj and Sam Goundar examine the kinds of threats facing cloud-based email systems and the mitigations available.

Attentional orienting to mnemonic representations: Reduction of load-sensitive maintenance-related activity in the intraparietal sulcus

The orienting of attention to internal or mnemonic representations held in visual working memory (VWM) has recently become a field of increasing interest. While a number of studies support the hypothesis that attention to selected representations in VWM reduces memory load, conclusive findings are still missing. In this event-related functional magnetic resonance imaging (fMRI) study, we directly investigated whether attentional orienting to mnemonic representations reduces activity in VWM storage-related areas of the brain. VWM load was manipulated by asking subjects to memorize two, four or six items. A retro-cue during the subsequent delay period asked subjects to attend to just one of these items for a subsequent test. This was compared to trials where subjects were required to continue attending to all items for the subsequent test. Data show reduction of load-sensitive maintenance-related activity along the right intraparietal sulcus (IPS), directly linked to attentional orienting. While activity in the anterior IPS reflected the number of representations in the focus of attention, the activation pattern in the posterior IPS suggested residual activation related to unattended items. This dissociation is in line with a functional subdivision of the right IPS according to attentional and mnemonic properties.

Continuous activity recognition in a maintenance scenario: combining motion sensors and ultrasonic hands tracking

We describe the design and evaluation of pattern analysis methods for the recognition of maintenance-related activities. The presented work focuses on the spotting of subtle hand actions in a continuous stream of data based on a combination of body-mounted motion sensors and ultrasonic positioning. The spotting and recognition approach is based on three core ideas: (1) the use of location information to compensate for the ambiguity of hand motions, (2) the use of motion data to compensate for the slow sampling rate and unreliable signal of the low cost ultrasonic positioning system, and (3) an incremental, multistage spotting methodology. The proposed methods are evaluated in an elaborate bicycle repair experiment containing nearly 10 h of data from six subjects. The evaluation compares different strategies and system variants and shows that precision and recall rates around 90% can be achieved.

Modulation of working-memory maintenance by directed attention

Many current models of working memory (WM) emphasize a close relationship between WM and attention. Recently it was demonstrated that attention can be dynamically and voluntarily oriented to items held in WM, and it was suggested that directed attention can modulate the maintenance of specific WM representations. Here we used event-related functional magnetic resonance imaging to test the effects of orienting attention to a category of stimuli when participants maintained a variable number of faces and scenes in WM. Retro-cues that indicated the relevant stimulus type for the subsequent WM test modulated maintenance-related activity in extrastriate areas preferentially responsive to face or scene stimuli – fusiform and parahippocampal gyri respectively – in a categorical way. After the retro-cue, the activity level in these areas was larger for the cued category in a load-independent way, suggesting the modulation may also reflect anticipation of the probe stimulus. Activity in associative parietal and prefrontal cortices was also modulated by retro-cues, and additionally co-varied with the number of stimuli of the relevant stimulus category that was being maintained. The findings suggest that these associative areas participate in maintaining the relevant memoranda in a flexible and goal-directed way to guide future behaviour.

Sleep Deprivation and Interference by Emotional Distracters

We determined if sleep deprivation would amplify the effect of negative emotional distracters on working memory. A crossover design involving 2 functional neuroimaging scans conducted at least one week apart. One scan followed a normal night of sleep and the other followed 24 h of sleep deprivation. Scanning order was counterbalanced across subjects. The study took place in a research laboratory. 24 young, healthy volunteers with no history of any sleep, psychiatric, or neurologic disorders. N/A Study participants were scanned while performing a delayed-response working memory task. Two distracters were presented during the maintenance phase, and these differed in content: highly arousing, negative emotional scenes; low-arousing, neutral scenes; and digitally scrambled versions of the pictures. Irrespective of whether volunteers were sleep deprived, negative emotional (relative to neutral) distracters elicited greater maintenance-related activity in the amygdala, ventrolateral prefrontal cortex, and fusiform gyri, while concurrently depressing activity in cognitive control regions. Individuals who maintained or increased distracter-related amygdala activation after sleep deprivation showed increased working memory disruptions by negative emotional distracters. These individuals also showed reduced functional connectivity between the amygdala and the ventromedial and dorsolateral prefrontal cortices, regions postulated to mediate cognitive control against emotional distraction. Increased distraction by emotional stimuli following sleep deprivation is accompanied by increases in amygdala activation and reduced functional connectivity between the amygdala and prefrontal cognitive control regions. These findings shed light on the neural basis for interindividual variation in how negative emotional stimuli might distract sleep deprived persons.

Sleep Deprivation and Interference by Emotional Distracters

We determined if sleep deprivation would amplify the effect of negative emotional distracters on working memory. A crossover design involving 2 functional neuroimaging scans conducted at least one week apart. One scan followed a normal night of sleep and the other followed 24 h of sleep deprivation. Scanning order was counterbalanced across subjects. The study took place in a research laboratory. 24 young, healthy volunteers with no history of any sleep, psychiatric, or neurologic disorders. N/A. Study participants were scanned while performing a delayed-response working memory task. Two distracters were presented during the maintenance phase, and these differed in content: highly arousing, negative emotional scenes; low-arousing, neutral scenes; and digitally scrambled versions of the pictures. Irrespective of whether volunteers were sleep deprived, negative emotional (relative to neutral) distracters elicited greater maintenance-related activity in the amygdala, ventrolateral prefrontal cortex, and fusiform gyri, while concurrently depressing activity in cognitive control regions. Individuals who maintained or increased distracter-related amygdala activation after sleep deprivation showed increased working memory disruptions by negative emotional distracters. These individuals also showed reduced functional connectivity between the amygdala and the ventromedial and dorsolateral prefrontal cortices, regions postulated to mediate cognitive control against emotional distraction. Increased distraction by emotional stimuli following sleep deprivation is accompanied by increases in amygdala activation and reduced functional connectivity between the amygdala and prefrontal cognitive control regions. These findings shed light on the neural basis for interindividual variation in how negative emotional stimuli might distract sleep deprived persons.

Neural dissociation of visual working memory consolidation and maintenance

Encoding of information into visual working memory (VWM), also known as short-term consolidation, is thought to represent a distinct process from maintenance of information (Jolicoeur & Dell'Acqua, 1998; Woodman & Vogel, 2004). In addition, VWM consolidation has been theorized to occupy a central role in conscious perception. Despite the fact that it has been the focus of much behavioral work, and that it is mechanistically dissociable from VWM maintenance, the neural substrates of VWM consolidation are poorly understood. Here we used functional magnetic resonance imaging (fMRI) to determine whether VWM consolidation is neurally dissociable from VWM maintenance. Participants performed a delayed recognition task that involved encoding and maintaining a variable number of colored discs over a retention interval (9.2s) that was long enough to distinguish encoding-related from maintenance-related activity. In two independent groups of subjects, we observed load-dependent, consolidation-related activity in lateral occipital cortex. By contrast, this brain region showed no maintenance-related activity. Control experiments indicate that the consolidation-related activity cannot be accounted for by perceptual processing. Finally, although several frontal and parietal cortex regions showed evidence of both encoding and maintenance-related activity, none showed consolidation-specific activity. Taken together, these results suggest that VWM consolidation is neurally dissociable from VWM maintenance.

Total productive maintenance experience: a case study

To be competitive in the liberalised economy, organisations must be supported by both effective and efficient maintenance. Manufacturing systems, in particular, often operate at less than full capacity, productivity is low and the costs of producing products are high. The experience has indicated that a large percentage of the total cost of doing business is due to maintenance-related activities in the organisation. One approach to improving performance of maintenance activities is to implement and develop a Total Productive Maintenance (TPM). TPM methods and techniques have been successfully implemented in Japan over the past three decades, and more recently in India. Inherent within the TPM concept are the aspects of enhancing the overall equipment effectiveness. This paper shares some of the experiences of TPM implementation in Mayur Uniquoters, India and achievements made while adopting and implementing TPM. It also identifies some of the difficulties faced during implementation, relates with the concept of TPM and proposes some solutions to eliminate them.

Category-specific modulation of inferior temporal activity during working memory encoding and maintenance

Findings from neurophysiology have supported the view that visual working memory (WM) relies on modulation of activity in object-selective populations of neurons in inferior temporal cortex. Here, using event-related functional magnetic resonance imaging, we investigated whether similar mechanisms support human visual working memory encoding and maintenance processes. We identified regions in inferior temporal cortex that exhibited category-specific responses during perception of faces (fusiform face area [FFA]) or scenes (parahippocampal place area [PPA]) and investigated whether activity in these regions would be modulated by demands to actively encode and maintain faces and scenes. Results showed that independent of perceptual stimulation, the FFA and PPA exhibited greater encoding- and maintenance-related activity when their favored stimulus was relevant to the recognition task. In contrast, maintenance-related activity in the dorsolateral prefrontal cortex (PFC) was modulated by memory load, regardless of the type of information that was task relevant. These results are consistent with the view that visual working memory encoding and maintenance processes are implemented through modulation of inferior temporal activity by prefrontal cortex.

Category-specific modulation of inferior temporal activity during working memory encoding and maintenance

Findings from neurophysiology have supported the view that visual working memory (WM) relies on modulation of activity in object-selective populations of neurons in inferior temporal cortex. Here, using event-related functional magnetic resonance imaging, we investigated whether similar mechanisms support human visual working memory encoding and maintenance processes. We identified regions in inferior temporal cortex that exhibited category-specific responses during perception of faces (fusiform face area [FFA]) or scenes (parahippocampal place area [PPA]) and investigated whether activity in these regions would be modulated by demands to actively encode and maintain faces and scenes. Results showed that independent of perceptual stimulation, the FFA and PPA exhibited greater encoding- and maintenance-related activity when their favored stimulus was relevant to the recognition task. In contrast, maintenance-related activity in the dorsolateral prefrontal cortex (PFC) was modulated by memory load, regardless of the type of information that was task relevant. These results are consistent with the view that visual working memory encoding and maintenance processes are implemented through modulation of inferior temporal activity by prefrontal cortex.

Aircraft fault isolation based on pattern of cockpit indications: a human factors approach

It is commonly recognised among operators of modern commercial aircraft that maintenance is a significant and costly part of their operation. In fact, it is estimated that 28% of all aircraft operating costs can be attributed to maintenance-related activities. A major portion of this activity can be classified as unscheduled, that is, maintenance other than regular servicing and periodic overhauls. Much of the cost of unscheduled maintenance derives from the actual man-hours and materials involved in isolating and replacing faulty components. However, additional consideration must be given to the fact that an aircraft which is detained beyond its scheduled departure time is neither producing revenue for the operating airline during that period, nor promoting goodwill among passengers inconvenienced by delays or cancellations.