Restoration Time Research Articles

Machine learning approaches to modeling interdependent network restoration time

Machine learning approaches to modeling interdependent network restoration time

Survey of Power System Restoration Documents Issued from 2016 to 2021

More than thirty-six partial or whole blackouts, from 2016 to 2021, prove that neither the probability of blackouts can be ignored nor the required plans and the readiness of the utilities for power system restoration can be forgotten. To properly deal with blackouts and minimize the social and economic costs, utilities should prepare a suitable restoration plan in advance to quickly restore the system to the normal state and minimize the restoration time and loss of energy. In this paper, after summarizing major blackouts occurred from 2016 to 2021, the progress in the research reports, industrial documents, and books in the context of power system restoration is reviewed to show and classify the different aspects of power system restoration plans and strategies presented during these years. This review indicates that although there are many published methods and techniques which have tried to give more autonomous solutions, there are still more complexities in power system restoration. However, this paper respects all efforts and attempts and tries to illustrate the achievements, up to now, in power system restoration, as well as research gaps.

Effects of vegetation type and topography on vegetation restoration after pipeline construction in the Northern Shaanxi Loess Plateau, China

AbstractVegetation disturbance during infrastructure construction can cause serious ecological problems, especially in fragile environments. The Northern Shaanxi Loess Plateau is an oil industry base in China with a fragile ecosystem. Vegetation restoration on the disturbance area can effectively control soil erosion and ensure the safety of oil pipelines. In the linear disturbance area, surrounding vegetation traits and topography may play an important role in vegetation restoration by influencing propagules and recruitment microsites. This study aimed to reveal the influence of vegetation type and topography on vegetation restoration in the disturbance area along the oil pipeline. The results showed that 89 species were recorded, and they belonged to 30 families and 74 genera. These species were mainly native herbaceous plants, especially perennial herbs. The species number and species diversity index in the disturbance area had a positive relationship with the undisturbed area. The lateral undisturbed vegetation type and species reproductive strategies influenced the vegetation restoration in the disturbance area. The species that produce a large number of seeds or regenerate by rhizome recolonized quickly in the disturbance area. However, the shrubs and arbor species that need seeds for recruitment will take a long time for restoration. The topographic factor had an obvious influence on the vegetation restoration and species diversity in the disturbance areas. On the sunny and steep slopes, vegetation restoration was difficult and slow, and artificial measures were needed to control soil erosion and maintain soil moisture to help seedling recruitment and survival.

Integrated and coordinated relief logistics and road recovery planning problem

Sudden onset disasters can block roads and hinder relief logistics. With the objective of facilitating access to critical locations in the disaster-stricken area, we propose a new mathematical model that determines the schedule and routes of a relief distribution team and a road restoration team. The road restoration team restores some of the blocked roads to provide faster access to critical nodes for the relief distribution team. We study the case in which the restoration times are stochastic, and our goal is to minimize the time by which the last demand node is met by the relief distribution team. We provide a detailed case study of our model with real data from Harris County in Texas, which was impacted by Hurricane Harvey during 2017. The results obtained from testing our model show that the objective function is decreased by up to 15% using the proposed non-myopic policy.

INFLUENCE OF METABOLIC THERAPY ON LIFE QUALITY IN PATIENTS WITH ATRIAL FIBRILLATION PAROXYSMS

Abstract. The goal of the study was to investigate the effect of magnesium orotate as a part of complex therapy in sinus rhythm restoring in patients with AF paroxysm, as well as to evaluate its effectiveness and effect on LQo with long-term use.
 Materials and research methods. We examined 56 patients (16 women and 40 men) with an average age of (61,5 ± 4,3) years with paroxysmal atrial fibrillation. All patients were divided into two groups. Patients of the 1st group (n=28) underwent medical cardioversion with amiodarone and magnesium orotate. Patients of the 2nd group (n=28) received only amiodarone. The time of sinus rhythm restoration, parameters of electrical instability of the atrial and ventricular myocardium after sinus rhythm restoration, patients life quality 3 months after discharge - were assessed in both groups.
 Results. The study allowed to reveal that the addition of magnesium orotate to the basic therapy of patients with atrial fibrillation increases the effectiveness of medical cardioversion and reduces the time of its onset. When using amiodarone and magnesium orotate, signs of electrical instability of the atrial myocardium (the number of paired and supraventricular extrasystoles) are significantly less according to the results of Holter electrocardiogram monitoring compared with amiodarone monotherapy. Atrial fibrillation caused a life quality parameters deviations in the form of an increase in the severity of the disease symptoms, physical activity limitation and psycho-emotional sphere disorders. 3 months after the treatment, it was noted that life quality in patients of the 1st group (complex therapy using magnesium orotate) was higher compared to patients of the 2nd group due to the improvement in the indicators of the "psycho-emotional" component.
 Conclusions. The addition of magnesium orotate to the basic therapy of paroxysmal atrial fibrillation can significantly improve the clinical course of the disease in patients and their life quality after 3 months treatment period.

Mitigation of the impact of disturbances in gas transmission systems

The current study presents a novel method for mitigating the consequences of disturbances in gas transmission systems (GTSs). The method presented was developed during the SecureGas project for identification of critical infrastructure and risk and resilience analysis. The method determines the optimal response strategies consisting of detailed coordination of demand curtailment for consumer nodes and the use of available reserve gas sources. Key characteristics of the method are an ability to adapt the modelling complexity for a particular task or a network part and several computational time economy measures making the method practical for large GTSs. The method can simultaneously consider variations of demand rates, consumer group compositions, source capacities, and average temperature and density of the gas in user-defined network parts during one or multiple concurrent disruptions in a GTS with different element restoration times. Preliminary analysis of a GTS model, which dynamically excludes network parts that are impossible to supply, implementation of a tailored genetic algorithm and supplemental sub-algorithms are used to save computation time while providing an optimal solution. A robust hydraulic steady-state solver is utilised for verification of solution feasibility in combination with dynamic changes to a GTS model implementing an adaptive network-wise control of multi-directional compressor stations and pressure regulators during different disturbance states of a GTS. A case study using a model of a real GTS demonstrated the effects of consumer categorisation and different modelling complexities, possible to consider with the developed method, on the estimated consequences of several types of disturbances and actions necessary to mitigate them by creating optimal response strategies.

Predetermined standby mode transfers in 1-out-of-N systems with resource-constrained elements

It has been shown that mode transfers can effectively balance the resource consumption and restoration time of standby systems. However, the existing methods assumed unlimited resource in each element, which is not practical for many real-world systems. This work advances the state of the art by considering resource-constrained system elements, which have some maximum lifetime due to resource depletion during the mission. The optimal element standby mode transfer problem is formulated and solved, which determines the mode transfer schedule minimizing the expected mission downtime (EMD). The solution methodology encompasses a new event transition-based numerical algorithm for evaluating the EMD of the considered 1-out-of-N standby system subject to mode transfers. Through the detailed analysis of a sensor standby system, it is revealed that the EMD decreases and the scheduled warm to hot mode transfer time increases as the element's initial available resource increases; the EMD increases as the element's resource consumption or stress level during the mode transfer increases; the EMD and its fraction in the mission time increases as the mission time increases; and it is beneficial to put the element with the smallest initial available resource into operation first.

EFFECTIVENESS OF ANULOM VILOM PRANAYAMA ON QUALITY OF SLEEP AMONG GERIATRICS AT SELECTED OLD AGE HOME

Background: Aging is a universal phenomenon, and it is a natural and inevitable process. According to the 2011 census, about 10.1% of the population is over 60 years; this is expected to increase to 20% in 2050. Globally 1% of the population average of 60 years, is rising, and it is likely to reach 30% of the world population by 2050. Sleep is a biological necessity; it is nature's gift of a particular time for rest, restoration, and recreation. As the age progresses towards senility, people experience several psycho-physiological problems. Often these problems create sleep disturbances among the elderly. Methods: The present study focused on evaluating Anulom Vilom Pranayama's effectiveness on the quality of sleep among geriatrics at Inba Illam and Geriatric home at Christian mission Hospital, Madurai. The research design adopted for the study was a quasi-experimental pre and post-test control group design. The selected samples were 60, of which 30 were allotted to the experimental group, and the remaining 30 were in the control group. The samples were recognized based on the inclusion criteria and picked up with Non-probability – convenience sampling technique. The sleep quality index rating scale was a tool for data collection. Results: The comparison of the mean post-test score of quality of sleep between the experimental and control group's unpaired “t” value was 14, which was highly signicant at p<0.001 level. It infers that the Anulom Vilom Pranayama effectively increases sleep among geriatrics. Conclusion: From the result, it was concluded that AnulomVilom Pranayama is an easily practicable and effective intervention method for the elderly population to improve the sleep quality

The Coupling Relationship between Herb Communities and Soil in a Coal Mine Reclamation Area after Different Years of Restoration

In a complete organic ecosystem restoration in mining areas, soil and vegetation complement and influence each other. It is of great significance to evaluate the ecological restoration effect on and ecosystem stability of the mining area, with the coupling and coordinating relationship between herb community and soil physicochemical properties after land reclamation. Therefore, this study takes Juxinlong Coal Mine in Dongsheng District of Ordos City, Inner Mongolia Autonomous Region as the study area. The understory herbaceous plant community and soil factors with restoration time of 3 to 7 years were selected as the research objects. In addition, artificial grassland and natural restoration grassland were used as controls to investigate the species composition of herbaceous communities and soil physicochemical properties in different sites. The grey relational coupling model was adopted not only to study the relationship between herb community and soil factors but also to explore the coupling mechanism between herb community and soils’ physicochemical properties. The results included: (1) 51 herbaceous plants were investigated in the study area, among which Gramineae, Compositae, Leguminosae, and Chenopodiaceae were the primary ones, accounting for 70% of the total. (2) With the increase of restoration years, the diversity indices of understory herbaceous plants generally showed an increasing trend, but the diversity indices of understory herbaceous plants with different restoration years was smaller than that of artificial grassland. (3) The results of grey correlation analysis showed that the diversity of herbaceous plant community in the study area was closely related to soils’ available nitrogen and water content. (4) The degree of coupling and coordinating between the diversity of herbaceous plants and soils in the study area presented a trend of first increasing then decreasing during the accumulating restoration years. Among them, the degree of coupling between the diversity of understory herbaceous plants and soil system in the 5-year restoration’s sample plot (0.73) was found to be the highest, which was classified as medium coordination. The lowest coupling degree of herb diversity and soils was identified in the artificial grassland (0.51), which was light incoordination. Therefore, it is suggested that the control of water and nitrogen resources should be strengthened, the herbaceous vegetation should be reasonably selected, and the artificial tending should be carried out in the later stage of understory herbaceous vegetation construction in the study area to better promote the vegetation construction in the mining area.

The Phenomena of Bursts by Opening Low-Voltage Relay

The article deals with the issue of electromagnetic disturbances caused by electromechanical relays. Electromagnetic compatibility (EMC) is important for the reliable work of electrical and electronic devices. Our research focused on the low-voltage relay, which is the source of electrical fast transients (EFT)/burst disturbances. The voltage and current waveforms were tested on the constructed stand while opening the relays’ contacts. We investigated one-circuit topology with varied element parameters in order to observe their influence on the burst phenomenon. The new technologies in the measurement equipment allow us to observe many detailed aspects of the burst phenomenon, which were not reported up to now. In order to analyze the disturbances, they have been fragmented into restoration, ignition and arc times. The number of disturbance cycles differs depending on the value of the circuit capacitance on the load side. The effect of capacity on times of restoration, ignition and burning arc was also observed. The division into cycles allowed us to observe changes in the studied phenomenon along with the increased distance between the relay contacts during its opening. There were also discrepancies between the presentation of the phenomenon in the standard defining the method of measuring the resistance to interference EFT/burst and the measurement results.

Aerial Seeding Promotes the Restoration of Ecosystem Health in Mu Us Sandy Grasslands in China

Grassland ecosystem health is related to global ecological problems, and large areas of grassland are threatened by degradation. Various measures, such as aerial seeding, have been applied to restore degraded grassland ecosystems. However, the effects of these measures remain unclear. In this study, based on the CVOR (condition, vitality, organization, and resilience) model, the entropy method was used to calculate the ecosystem health of aerial seeding restoration sites in the Mu Us sandy grassland, China. Then, the relationship between CVOR value, various indices in the model, and restoration time was measured using correlation analysis. The results show that (1) the vitality criterion layer has the highest weight in the CVOR model; (2) the cautionary hierarchy is the most (40.0%), and the healthy hierarchy is the opposite (10.0%) among all the restoration sites; and (3) 30-year aerial seeding can promote ecosystem health in sandy grasslands. This study demonstrates that aerial seeding is an effective method for restoring degraded grassland ecosystems and can guide future restoration measures and policies for degraded ecosystems.

Digitally prefabricated versus conventionally fabricated implant-supported full-arch provisional prosthesis: a retrospective cohort study

BackgroundTo evaluate and compare the clinical outcomes of digitally prefabricated and conventionally fabricated implant-supported full-arch provisional prostheses.MethodsIn this retrospective study, a total of 39 patients (22 males and 17 females) who underwent implant-supported full-arch rehabilitation using the All-on-4 concept with an immediate loading protocol were included: 20 patients treated with digitally prefabricated provisional prostheses were assigned into Group A, and 19 patients treated with conventionally fabricated provisional prostheses were assigned into Group B. Implant/provisional prosthesis survival rates and complications were reviewed. Marginal bone loss (MBL) was investigated by CBCT. Surgical time, restorative time, and total operative time were analyzed. Postoperative pain and swelling were evaluated with the visual analog scale (VAS). The oral health impact profile (OHIP) questionnaire was administered before and after surgery.ResultsThe implant/provisional prosthesis survival rate was 100%, and complications appeared with low frequency in both groups, while the mean MBL was 0.30 ± 0.29 mm in Group A and 0.31 ± 0.41 mm in Group B after 3~ 6 months (P > 0.05). The average restorative time in Group A (116.16 ± 16.61 min) was significantly shorter than that in Group B (242.11 ± 30.14 min) (P < 0.05). Patients in Group A showed lower pain/swelling VAS scores after surgery than Group B (P < 0.05). Low OHIP scores with high satisfaction with the overall effects were shown in both groups.ConclusionPrefabricated prostheses reduced the prosthetic time and postoperative discomfort in patients whose immediate rehabilitation was based on the All-on-4 concept. This prefabrication technology may be a predictable alternative to improve the short-term clinical outcome of implant-supported full-arch provisional rehabilitation.

A large-scale equilibrium model of energy emergency production: Embedding social choice rules into Nash Q-learning automatically achieving consensus of urgent recovery behaviors

A large-scale energy emergency production plan driven by extreme events in energy supply chain networks is the low-probability/high-consequence event that is difficult to prepare. One of the most prominent challenges is efficiently computing the equilibrium point characterized with more frequently involved in common resource conflicts due to different player behaviors in energy supply chain networks. In this paper, a novel large-scale equilibrium model of energy emergency production: embedding social choice rules into Nash Q-learning automatically achieving consensus of urgent recovery behaviors, is proposed to tackle this challenge. The main contributions of this work are that firstly set up a large-scale equilibrium model of energy emergency production to formulate energy emergency production plans by modifying the large-scale energy equilibrium model, and the computational limitations of Generalized Nash Equilibrium are overcame by combination of Nash Q-learning methods and individuals’ preferences reaching a collective decision which guarantees uniqueness of the large-scale Nash equilibrium to achieve both system-level efficiency and maximum fairness. Simulations results show that the generalized Nash bargaining solution can be implemented by the proposed large-scale equilibrium model of energy emergency production, in which outcome of the game is the emergency production stable equilibria alternative with no chance moves in a given consensus level, and compared with the existing techniques considering non-cooperative behaviors, it has a significantly lower minimisation of time for the energy restoration by twenty-nine percent, and reduces minimisation of cost for the energy restoration by seventeen percent and minimisation of carbon dioxide emissions by twenty-three percent with disaster recovery.

A Stochastic Markov Model for Maintenance Scheduling in the Presence of Online Monitoring System

Active electricity distribution systems (AEDS) play an important role on the social welfare that is highly relies on the reliability of these systems. In this regard, maintenance management tries to decrease component failures via repairing component that are more possible to be failed in operation time. In this manuscript, a stochastic MINLP maintenance scheduling model is proposed in which the reliability of AEDS's equipment is considered through employing a three-state Markov model. This model helps us to embed the uncertainty of AEDS's equipment service restoration time by considering online monitoring system for it and FLISR functions in AEDS. In this paper, minimizing the total cost of AEDS is determined as objective function considering total customer interruption cost, total cost of energy not supplied, total cost of prevented maintenance actions, total corrective maintenance actions cost implemented in the AEDS and total cost of implementing online monitoring for AEDS's component in maintenance scheduling. The proposed framework is applied in two different cases, Case I is maintenance scheduling without online monitoring system and Case II is maintenance scheduling with online monitoring system. The aforementioned cases are implemented in an IEEE Test System as well as a real scale distribution network. Moreover, several sensitivity analyses are implemented for indicating the efficiency of the proposed model.

Monitoring of Vegetation Disturbance and Restoration at the Dumping Sites of the Baorixile Open-Pit Mine Based on the LandTrendr Algorithm

Overstocked dumping sites associated with open-pit coal mining occupy original vegetation areas and cause damage to the environment. The monitoring of vegetation disturbance and restoration at dumping sites is important for the accurate planning of ecological restoration in mining areas. This paper aimed to monitor and assess vegetation disturbance and restoration in the dumping sites of the Baorixile open-pit mine using the LandTrendr algorithm and remote sensing images. Firstly, based on the temporal datasets of Landsat from 1990 to 2021, the boundaries of the dumping sites in the Baorixile open-pit mine in Hulunbuir city were extracted. Secondly, the LandTrendr algorithm was used to identify the initial time and duration of vegetation disturbance and restoration, while the Normalized Difference Vegetation Index (NDVI) was used as the input parameter for the LandTrendr algorithm. Thirdly, the vegetation restoration effect at the dumping sites was monitored and analyzed from both temporal and spatial perspectives. The results showed that the dumping sites of the Baorixile open-pit mine were disturbed sharply by the mining activities. The North dumping site, the South dumping site, and the East dumping site (hereinafter referred to as the North site, the South site, and the East site) were established in 1999, 2006, and 2010, respectively. The restored areas were mainly concentrated in the South site, the East site, and the northwest of the North site. The average restoration intensity in the North site, South site, and East site was 0.515, 0.489, and 0.451, respectively, and the average disturbance intensity was 0.371, 0.398, and 0.320, respectively. The average restoration intensity in the three dumping sites was greater than the average disturbance intensity. This study demonstrates that the combination of temporal remote sensing images and the LandTrendr algorithm can follow the vegetation restoration process of an open-pit mine clearly and can be used to monitor the progress and quality of ecological restoration projects such as vegetation restoration in mining areas. It provides important data and support for accurate ecological restoration in mining areas.

Fault indicator placement optimization using the cross-entropy method and traffic simulation data

This paper presents an approach to optimize the placement of fault indicator devices in distribution systems using the cross-entropy method and results from traffic simulations. The problem formulation takes into account the impact of the devices on restoration times and costs due to fines related to service interruption reliability indices. Candidate solutions to the problem are evaluated using sequential Monte Carlo simulations, where travel times of maintenance crews are sampled according to data acquired from mobility traffic simulations. Results show the applicability of the approach in different simulation scenarios and the benefits of installing the devices in distribution networks.

Markovian queueing model with catastrophe, unreliable and backup server

In this article, we considered a finite size Markovian queue with single server. When the server breaks down, in order to facilitate the customer, backup server is provided. When system happened to undergo catastrophe, the customers are being removed and by restoration time the system get back to its normal state. Here, we have analysed the number of times the system reached its capacity. By utilising matrix geometric method, model has been solved and measures of effectiveness are done. Also numerical examples and graphical representation are given.

A Framework for Reliability Assessment in Expansion Planning of Power Distribution Systems

This article proposes a framework that uses analytical assessment of reliability to guide the expansion planning of power distribution systems (PDS) considering reliability criteria. The framework allows the estimation of reliability indices with and without the execution of expansion projects, thus supporting the decision-making process on investments in expansion projects. In the analytical assessment of reliability, failure rates of zones and restoration times are calculated from past data of interruptions in the primary distribution network. In addition, the estimated reliability indices are adjusted to historical values through failure rates proportionate to the length of each zone. To test and validate the proposed framework, it was applied to the distribution network at bus 5 of the Roy Billinton Test System (RBTS) and also to a real distribution feeder located in Brazil. The results indicated that the proposed framework can help define the most attractive investments leading to improvements in reliability indices and reduction in unsupplied energy. The estimation of reliability indices and energy not supplied, considered the following expansion alternatives: (i) the installation of normally-closed sectionalizing switches, (ii) the installation of normally-open switches with interconnection to adjacent feeders, (iii) the automation of switches, and (iv) the reconductoring of zones of the primary distribution network. Nevertheless, the proposed framework allows the inclusion of other expansion alternatives. Finally, the proposed framework proved to be handy and useful for real-life applications.

Development of Iron fortified potato fries through Vacuum assisted processing strategies.

Potato fries, a relatively an untapped food matrix for fortification, was fortified with iron using vacuum impregnation technique and impact of this fortification on quality attributes (structure, color, texture, flavor, acrylamide, sensory characteristics) of the product was assessed. Further, to reduce the dietary restraints of consumers for fried fries, fat reduction was achieved using vacuum frying. Ferrous ammonium sulphate hexahydrate was used as a fortificant to yield 3.15mg iron from 30g fries (RACC for snacks- Recommended Amount Customarily Consumed). Effect of iron fortificant level, blanching, vacuum and restoration time (independent variable) were evaluated on responses (iron impregnation level and firmness) of fries using box-behnken design of response surface methodology. Results showed that blanching time was the most significant variable affecting iron impregnation followed by iron concentration and vacuum time. Ferrous ammonium sulphate hexahydrate was found to be the most appropriate fortificant since reflecting the least colour and sensory changes in fries. A fortified raw potato fries when fried under vacuum, provided better retention of colour and reduced fat absorption (by 17.72%) with comparable crispiness (0.37kg/sec vs 0.35kg/sec), firmness (0.39kg/sec vs 0.38kg/sec), color (ΔE = 1.39) and sensory score (7.9 vs 8.1 on 9-point scale) with control fries.

BULK FILL COMPOSITE RESIN RESTORATION TECHNIQUES REPLACE INCREMENTAL TECHNIQUES

Introduction: Shrinkage during the polymerization process is the main disadvantage of using composite resins because it creates pressure between the tooth and the restoration which causes failure of the adhesion of the composite resin to the tooth, micro-fissures, and cuspid deflection. Review: To reduce shrinkage that occurs, it is known that conventional composite resins must be inserted into the cavity incrementally or in layers with a maximum thickness of 2 mm per layer. However, the incremental insertion method has several disadvantages, namely that it requires a longer clinical time for restoration. To overcome the shortcomings of these conventional composites, Bulk-fill composite resin was introduced. Composite bulk fill is a sophisticated technology that allows composites to be directly placed on the restoration, has a low polymerization shrinkage to reduce micro-leakage, reduces stress in the presence of elasticity, increases the depth of at least 4 mm translucent at the time of application, is very conducive to light transmission, is more flowable to allow adaptation to the cavity, including cervical margins, it is easy to apply with minimal handling and is resistant to large stresses. Conclusion: With the characteristics possessed by the Bulk-fill composite resin, it is known that the bulk-fill technique in addition to reducing the clinical application time, can also improve the edge adaptation between the restoration and the tooth compared to the incremental technique, without reducing its physical strength.