Given Level Of Reliability Research Articles

Developing a Sampling Plan for Brown Stink Bug (Hemiptera: Pentatomidae) in Field Corn.

Brown stink bug, Euschistus servus (Say), is a damaging pest of corn, Zea mays (L.), in the southeastern United States. Developing a reliable and practical sampling plan for population monitoring of this pest is essential for implementing integrated pest management measures. E. servus was sampled from commercial corn fields (n = 14) in North Carolina in 2016 and 2017. Both the adults and nymphs had a predominantly aggregated spatial distribution, estimated using the variance to mean ratio and Taylor's power law constant (b). Using the Taylor's power law constants, the optimum sample size required to estimate population density with a given level of reliability was calculated. For early vegetative stage corn (V4-V6), using whole plant visual sampling and an economic threshold density of 2 adult stink bugs per 20 plants, 27 sample units were required to estimate population density within 30% of the mean. At the same growth stage, using partial plant sampling and an economic threshold density of 1.73 adult stink bugs per 20 plants, 28 sample units were required to estimate population density with the same level of reliability. Reproductive stage corn (R1-R4) required eight sample units for whole plant sampling and nine sample units for partial plant sampling (Dx = 0.3). For E. servus adults, the partial plant sampling method was equally or more cost-reliable than the whole-plant sampling method for pest management in all corn growth stages tested.

THE WAYS TO IMPROVE RELIABILITY OF POWER SUPPLY CIRCUITS OF GROUND STATIONARY OBJECTS ELECTRONIC EQUIPMENT

Modern radio electronic equipment (REE) in various areas of economic activity performs increasingly complex tasks at sites with increased levels of responsibility. This circumstance increases the dependence of the operation of the REE on the uninterrupted power supply and its quality level, as well as on the level of fault tolerance of an important auxiliary part of the REE - power supply system (PSS), which significantly affects the ability of the REE to perform its tasks. The results of the analysis of existing and search for promising ways to ensure a given level of reliability of REE associated with its power supply problems show the need for an integrated approach to choosing the most effective option. It consists in the cumulative implementation of the process indicated by the newly introduced term «reliability of the power supply chain (PSC) of the REE», combining the continuity of supplying REE with electricity of the established level of quality and trouble-free operation of the PSS performing the conversion of the initial electricity to the form and the values of its parameters acceptable for the power supply of the functional units REE. Ways to improve the reliability of the PSC of the REE of ground stationary objects are considered for two of its characteristic types - a computer system (CS) and a telecommunication system (TS) with a single-phase voltage of 220V; 50Hz and the value of power consumption to 3-5kW. In terms of increasing the continuity of electricity supply, the feature of the proposed solutions is the achievement of the set goal by additional use of existing resources of the facilities of the REE installation. In some cases, their limited increase is also envisaged. In order to increase the fault tolerance, the PSS REA suggests: in the centralized part of the PSS - the application of the trunk-modular architecture, the choice of the effective structure, and also the adaptive methods and algorithms for management and redundancy, in the distributed part of the PSS - optimization of the structure and minimization of the number of constituent parts.

MODELING AN EFFECTIVE SYSTEM FOR DIAGNOSING A TRACTION MOTOR WITH ACCOUNTING FOR SELECTION OF ITS ELEMENTS ASSEMBLY OPTIONS

Purpose. The purpose of study is the simulation the parameters of the locomotive traction motor diagnosis system to ensure a given level of reliability. Methodology. The research was carried out on the basis of the multi-criteria optimization procedure, methods of the reliability theory and the recovery theory. Results. The procedure of multicriteria optimization for the traction motor diagnostics system was presented that accounts for the following quality indicators: the number of diagnostic moments, and the mean time to failure. A method for constructing the moments of diagnosing components of a traction motor have been presented with the further determination of rational volumes of diagnosis and determination of corresponding resulting moments of diagnosing the engine as a single system. The diagnosis moments are selected so that the failure probability of the components does not fall below the pre-set value. Novelty. A new method for constructing a rational system for diagnosing a traction motor has been proposed by the definition of the Pareto criteria: the number of diagnostic tests, the mean time between failures. Practical value. The Research was carried out with the State Program for the Strategic Development of Railways of Ukraine prepared by the State Research Center for Railway Transport of Ukraine in conjunction with the specialists of Ukrzaliznytsia, and Renovation Program of the Traction Rolling-Stock of Railways to the 2020 year. The necessary quality of the diagnostic system should be determined according to the diagnosed object, taking into account the requirements imposed on the latter. The system of diagnosing of a technical object depends on the production technology and the technology of renovation of the components used, which makes it possible to choose the performer of the repair work or the manufacturer of the components of the technical object.

Визначення системи діагностування ТЕД з урахуванням вибору бажаних елементів зі змінною інтенсивністю відмов

The purpose of study is the simulation the parameters of the locomotive traction motor diagnosis sys-tem to ensure a given level of reliability. The research was carried out on the basis of the multi-criteria optimization procedure, methods of the reliability theory and the recovery theory. The procedure of multicriteria optimization for the traction motor diagnostics system was presented that accounts for the following quality indicators: the number of diagnostic moments, and the mean time to failure. A method for constructing the moments of diagnosing components of a traction motor have been presented with the further determination of ra-tional volumes of diagnosis and determination of corresponding resulting moments of diagnosing the engine as a single system. The diagnosis moments are selected so that the failure probability of the components does not fall below the pre-set value. A new method for constructing a rational system for diagnosing a traction motor has been proposed by the definition of the Pareto criteria: the number of diagnostic tests, the mean time between failures. The Research was carried out with the State Program for the Strategic Development of Railways of Ukraine prepared by the State Research Center for Railway Transport of Ukraine in conjunction with the specialists of Ukrzaliznytsia, and Renovation Program of the Traction Rolling-Stock of Railways to the 2020 year. The necessary quality of the diagnostic system should be determined according to the diagnosed object, taking into account the requirements imposed on the latter. The system of diagnosing of a technical object depends on the production technology and the technology of renovation of the components used, which makes it possible to choose the performer of the repair work or the manufacturer of the components of the technical object

QoI-Aware Unified Framework for Node Classification and Self-Reconfiguration Within Heterogeneous Visual Sensor Networks

Due to energy and throughput constraints of visual sensing nodes, in-node energy conservation is one of the prime concerns in visual sensor networks (VSNs) with wireless transceiving capability. To cope with these constraints, the energy efficiency of a VSN for a given level of reliability can be enhanced by reconfiguring its nodes dynamically to achieve optimal configurations. In this paper, a unified framework for node classification and dynamic self-reconfiguration in VSNs is proposed. The proposed framework incorporates quality-of-information (QoI) awareness using peak signal-to-noise ratio-based representative metric to support a diverse range of applications. First, for a given application, the proposed framework provides a feasible solution for the classification of visual sensing nodes based on their field-of-view by exploiting the heterogeneity of the targeted QoI within the sensing region. Second, with the dynamic realization of QoI, a strategy is devised for selecting suitable configurations of visual sensing nodes to reduce redundant visual content prior to transmission without sacrificing the expected information retrieval reliability. The robustness of the proposed framework is evaluated under various scenarios by considering: 1) target QoI thresholds; 2) degree of heterogeneity; and 3) compression schemes. From the simulation results, it is observed that for the second degree of heterogeneity in targeted QoI, the unified framework outperforms its existing counterparts and results in up to 72% energy savings with as low as 94% reliability.

Identification of medicobiological parameters system of clinical monitoring for family medicine

The paper examines the problems associated with collecting and processing the data on medico-biological parameters of patients. These problems are considered in terms of solving the problem of clinical monitoring. Implementing the clinical monitoring process suggests that a family doctor should have modern diagnostic equipment. Such equipment can collect primary medical data and transmit them to the server side for the automated processing. Health Grid infrastructure technologies enable distributed data processing of a large number of patients. These patients may relate to different doctors from different medical institutions. Such an approach allows to collect a large amount of statistical data that can be used for the individual needs of a certain patient and comprehensive epidemiological analysis in the country or in a particular area. The open e-Health architecture platform ensures the operation of sensors that collect medical data of patients during clinical monitoring. These data can be transmitted via a wired or wireless connection to the microcontroller and the server. Processed data from many patients allow to build intelligent algorithms that detect dependencies between the values of medico-biological parameters and diagnosis. In addition, various medical research data can be collected from the web space. These two types of data can be used for developing collaborative recommendation systems. Such systems are some kind of decision support systems that provide family doctors with the possible options of diagnoses and useful recommendations in a convenient form and with a given level of reliability and accuracy.

Criteria for early etiological diagnosis of serous meningitis in children

To improve early etiological diagnosis of serous meningitis in children, the differential diagnostic algorithms have been developed.Methods. 220 children with serous meningitis(SM) aged 1 to 17 years were divided into 3 groups depending on the etiological factor: 1) enterovirus SM (n=130); 2) herpesvirus SM (n=14); 3) enterovirus SM combined with persistent herpes virus infection (n=76). In the alternative groups of patients (in all combinations), the differential diagnostic significance of clinical and laboratory parameters has been evaluated by means of Wald–Genkin heterogeneous sequential procedure. All studied traits were divided into gradations and then differential diagnostic coefficients (DC) and diagnostic information (I) were obtained separately for the clinical indicators, CSF indicators and full blood count. The indicators were distributed in the descending order of their self-descriptiveness that, in future, taking into account the most significant of them, allowed to form a generalized diagnostic algorithms in each comparison group.Results. Differential algorithmic diagnosis is obtained by means of algebraic summation of DC until the diagnostic threshold is reached. For 95 percent confidence level, the threshold sum is DK≥13,0. Etiologic diagnosis of SM involves the use of all three algorithms, that is, differentiation is conducted between SM herpesvirus, enterovirus etiology and SM enterovirus etiology in combination with persistent herpes virus infection. When reaching the diagnostic threshold in favor of certain etiology, the appropriate diagnosis is made. In case the diagnostic threshold for two etiological factors is reached, the final diagnosis is formulated on the basis of the differential diagnosis data.Conclusions. The developed algorithms of early etiological diagnosis of SM in children are highly reliable (≥95%) and minimize the number of indicators required for diagnosis with a given level of reliability

A hybrid method for transportation with stochastic demand

In industrial transportation, the forecast demand at each destination may be affected by a number of factors. Consequently, a conventional transport plan often fails to match the reality, and the planned transport capacity is either insufficient to meet the demand or wastefully excessive. In this paper, we introduce a new algorithm to generate a minimal cost transport plan that meets a given level of reliability. The reliability of a candidate solution is measured through simulating each candidate solution against a large number of scenarios. To search for reliable solutions, a genetic algorithm method is applied as an external loop. The minimal transport cost is achieved through a deterministic optimisation algorithm. We show that this problem decomposition in principle enables the optimal solution of the original non-deterministic problem to be found. Experimental results establish the practical usefulness of the proposed algorithm.

Development of acceleration factors for reliability testing of mechanical equipment

Accelerated life tests allow for reduction of test time to demonstrate targeted life of a component for a given level of reliability. This is accomplished by increasing loads on the component or by compressing the time scale in relation to the service environment. The acceleration factor provides a quantitative estimate of the relationship between the test condition and the field condition for this purpose. This paper provides a detailed process, for developing acceleration factor models for reliability testing of mechanical components. Several examples are given for various types of mechanical components undergoing wear-out processes.

Expanding Renewable Energy by Implementing Demand Response

We evaluate the impacts of DR in future electricity systems and to what extent they can facilitate the spread of high shares of renewable energy while maintaining a given level of reliability. We propose an approach based on long-term planning models, the MARKAL/TIMES models and our analysis is demonstrated by the case of Reunion Island, which aims to produce electricity using 100% renewable energy sources by 2030. We demonstrate that higher shares of intermittent sources weaken reliability of supply and can be counter balanced through demand response solutions.

Quality-of-Service Routing Protocol for Wireless Sensor Networks

In this paper, we develop new algorithms to find the optimal, energy preserving, paths from Source Node (SN) to the Base Station (BS) in Wireless Sensor Networks (WSNs). Optimality is defined in a constrained sense, in which the minimal energy route is sought (to maximize the lifespan of WSNs) under reliability constraint, meaning that each packet must reach the BS with a given probability. Energy efficiency is going to be achieved by selecting nodes for multi-hop packet forwarding under information, which yields the most evenly distributed energy state over the network after the packet has reached the BS. The new algorithm gave good results with any BS positioning in sensor networks. The simulation results will demonstrate that our algorithm is more efficient than the other routing protocols proposed before. There are many efficient protocols which increase the lifetime of sensor network such as LEACH, PEGASIS, PEDAP and PEDAP-PA, but they failed to provide energy ba-lancing under reliability constraints. In this paper, we propose a new algorithm under name HQRA (High Quality of service Routing Algorithm), which is able to find near-optimal paths in WSNs by minimizing the energy but guaranteeing a given level of reliability, as well.

Моделирование работы системы снабжения промышленного предприятия при заданном уровне надежности

Моделирование работы системы снабжения промышленного предприятия при заданном уровне надежности

Hydrological evaluation of satellite-based rainfall estimates over the Volta and Baro-Akobo Basin

Summary How useful are satellite-based rainfall estimates (SRFE) as forcing data for hydrological applications? Which SRFE should be favoured for hydrological modelling? What could researchers do to increase the performance of SRFE-driven hydrological simulations? To address these three research questions, four SRFE (CMORPH, RFE 2.0, TRMM-3B42 and PERSIANN) and one re-analysis product (ERA-Interim) are evaluated within a hydrological application for the time period 2003–2008, over two river basins (Volta and Baro-Akobo) which hold distinct physiographic, climatologic and hydrologic conditions. The focus was on the assessment of: (a) the individual and combined effect of SRFE-specific calibration and bias correction on the hydrological performance, (b) the level of complexity required regarding bias correction and interpolation to achieve a good hydrological performance, and (c) the hydrological performance of SRFE during high- and low-flow conditions. Results show that (1) the hydrological performance is always higher if the model is calibrated to the respective SRFE rather than to interpolated ground observations; (2) for SRFE that are afflicted with bias, a bias-correction step prior to SRFE-specific calibration is essential, while for SRFE with good intrinsic data quality applying only a SRFE-specific model calibration is sufficient; (3) the more sophisticated bias-correction method used in this work (histogram equalization) results generally in a superior hydrological performance, while a more sophisticated spatial interpolation method (Kriging with External Drift) seems to be of added value only over mountainous regions; (4) the bias correction is not over-proportionally important over mountainous catchments, as it solely depends on where the SRFE show high biases (e.g. for PERSIANN and CMORPH over lowland areas); and (5) the hydrological performance during high-flow conditions is superior thus promoting the use of SRFE for applications focusing on the high-end flow spectrum. These results complement a preliminary “ground truthing” phase and provide insight on the usefulness of SRFE for hydrological modelling and under which conditions they can be used with a given level of reliability.

Realization strategies of dedicated path protection: A bandwidth cost perspective

Communication networks have to provide a high level of availability and instantaneous recovery after failures in order to ensure sufficient survivability for mission-critical services. Currently, dedicated path protection (or 1+1) is implemented in backbone networks to provide the necessary resilience and instantaneous recovery against single link failures with remarkable simplicity. However, in order to satisfy strict availability requirements, connections also have to be resilient against Shared Risk Link Group (SRLG) failures. In addition, switching matrix reconfigurations have to be avoided after a failure in order to guarantee instantaneous recovery. For this purpose, there are several possible realization strategies improving the characteristics of traditional 1+1 path protection by lowering reserved bandwidth while conserving all its favorable properties. These methods either utilize diversity coding, network coding, or generalize the disjoint-path constraint of 1+1.In this paper, we consider the cost aspect of the traditional and the alternative 1+1 realization strategies. We evaluate the bandwidth cost of different schemes both analytically and empirically in realistic network topologies. As the more complex realizations lead to NP-complete problems even in the single link failure case, we propose both Integer Linear Programming (ILP) based optimal methods, as well as heuristic and meta-heuristic approaches to solve them. Our findings provide a tool and guidelines for service providers for selecting the path protection method with the lowest bandwidth cost for their network corresponding to a given level of reliability.

Design of reliable communication networks: A hybrid ant colony optimization algorithm

This article proposes a hybrid approach based on Ant Colony Optimization (ACO) and Simulated Annealing (SA), called ACO_SA, for the design of communication networks. The design problem is to find the optimal network topology for which the total cost is a minimum and the all-terminal reliability is not less than a given level of reliability. The proposed ACO_SA has the advantages of the ability to find higher performance solutions, created by the ACO, and the ability to jump out of local minima to find better solutions, created by the SA. The effectiveness of ACO_SA is investigated by comparing its results with those obtained by individual application of SA and ACO, which are basic forms of ACO_SA, two different genetic algorithms and a probabilistic solution discovery algorithm given in the literature for the design problem. Computational results show that ACO_SA has a better performance than its basic forms and the investigated heuristic approaches.

A cross entropy approach to design of reliable networks

One of the most important parameters determining the performance of communication networks is network reliability. The network reliability strongly depends on not only topological layout of the communication networks but also reliability and availability of the communication facilities. The selection of optimal network topology is an NP-hard problem so that computation time of enumeration-based methods grows exponentially with network size. This paper presents a new solution approach based on cross-entropy method, called NCE, to design of communication networks. The design problem is to find a network topology with minimum cost such that all-terminal reliability is not less than a given level of reliability. To investigate the effectiveness of the proposed NCE, comparisons with other heuristic approaches given in the literature for the design problem are carried out in a three-stage experimental study. Computational results show that NCE is an effective heuristic approach to design of reliable networks.

Effect of temporal sparseness and dichoptic presentation on multifocal visual evoked potentials

Multifocal VEP (mfVEP) responses were obtained from 13 normal human subjects for nine test conditions, covering three viewing conditions (dichoptic and left and right monocular), and three different temporal stimulation forms (rapid contrast reversal, rapid pattern pulse presentation, and slow pattern pulse presentation). The rapid contrast reversal stimulus had pseudorandomized reversals of checkerboards in each visual field region at a mean rate of 25 reversals/s, similar to most mfVEP studies to date. The rapid pattern pulse presentation had pseudorandomized presentations of a checkerboard for one frame, interspersed with uniform grey frames, with a mean rate of 25 presentations/s per region per eye. The slow pattern pulse stimulus had six presentations/s per region per eye. Recording time was 5.3 min/condition. For dichoptic presentation slow pattern pulse responses were 4.6 times larger in amplitude than the contrast reversal responses. Binocular suppression was greatest for the contrast reversal stimulus. Consideration of the signal-to-noise ratios indicated that to achieve a given level of reliability, slow pattern pulse stimuli would require half the recording time of contrast reversal stimuli for monocular viewing, and 0.4 times the recording time for dichoptically presented stimuli. About half the responses to the slow pattern pulse stimuli had peak value exceeding five times their estimated standard error. Responses were about 20% smaller in the upper visual field locations. Space-time decomposition showed that responses to slow pattern pulse were more consistent across visual field locations. We conclude that the pattern pulse stimuli, which we term temporally sparse, maintain the visual system in a high contrast gain state. This more than compensates for the smaller number of presentations in the run, and provides signal-to-noise advantages that may be valuable in clinical application.

Generalisability: a key to unlock professional assessment.

Reliability is defined as the extent to which a result reflects all possible measurements of the same construct. It is an essential measurement characteristic. Unfortunately, there are few objective tests for the most important aspects of the professional role because they are complex and intangible. In addition, professional performance varies markedly from setting to setting and case to case. Both these factors threaten reliability. This paper describes the classical approach to evaluating reliability and points out the limitations of this approach. It goes on to describe how generalisability theory solves many of these limitations. A G-study uses variance component analysis to measure the contributions that all relevant factors make to the result (observer, situation, case, assessee and their interactions). This information can be combined to reflect the reliability of a single observation as a reflection of all possible measurements - a true reflection of reliability. It can also be used to estimate the reliability of a combined sample of several different observations, or to predict how many observations are required with different test formats to achieve a given level of reliability. Worked examples are used to illustrate the concepts.

Emergency ambulance deployment in Barbados: a multi-objective approach

A multi-objective version of the Maximum Availability Location Problem is presented in this paper. The assumption of server independence is relaxed by adopting the approach of the Queuing Probabilistic Location Set Covering Problem for calculating the probability that all servers in a given region are busy. The first objective seeks to maximize the population receiving coverage within a given distance standard and with a given level of reliability. The second objective chooses those locations which minimize the cost of covering the population. This model is used to obtain sets of good locations using data obtained from the Barbados Emergency Ambulance Service. The solutions obtained from the optimization model are then subject to a detailed analysis by simulation. The results reveal the potentially good performance of the system, when locations derived from the optimization model are used.

Emergency ambulance deployment in Barbados: a multi-objective approach

A multi-objective version of the Maximum Availability Location Problem is presented in this paper. The assumption of server independence is relaxed by adopting the approach of the Queuing Probabilistic Location Set Covering Problem for calculating the probability that all servers in a given region are busy. The first objective seeks to maximize the population receiving coverage within a given distance standard and with a given level of reliability. The second objective chooses those locations which minimize the cost of covering the population. This model is used to obtain sets of good locations using data obtained from the Barbados Emergency Ambulance Service. The solutions obtained from the optimization model are then subject to a detailed analysis by simulation. The results reveal the potentially good performance of the system, when locations derived from the optimization model are used.