The Experts below are selected from a list of 237 Experts worldwide ranked by ideXlab platform
R Billinton - One of the best experts on this subject based on the ideXlab platform.
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locational transmission Capacity Reserve determination using system well being analysis
Electric Power Systems Research, 2015Co-Authors: Wijarn Wangdee, R BillintonAbstract:Abstract This paper presents a methodology to determine the locational transmission Capacity Reserve required to provide additional transmission transfer capability to access remote generation. The methodology is based on translating the accepted deterministic criteria into probabilistic measures using the system well-being analysis framework. The objective of utilizing system well-being analysis is to help to identify and characterize the actual system reliability concerns regarding the exclusive use of deterministic criteria, and to help to determine what the appropriate deterministic reliability criteria should be so that power utilities can adjust and expand the deterministic criteria to cope with uncertainty considerations that exist in practical power systems. An application of system well-being analysis to determine the locational transmission Capacity Reserve on an actual island system in Canada is illustrated in this paper.
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Load forecast uncertainty considerations in bulk electric system reliability assessment
2008 40th North American Power Symposium, 2008Co-Authors: Dange Huang, R BillintonAbstract:Load forecast uncertainty is an important factor in long range system planning and has been shown to have a significant impact on the calculated reliability indices in generating Capacity studies. In general, a higher Capacity Reserve is required to satisfy a future uncertainty load than to serve a known load, at a specified level of reliability. Load forecast considerations are also important in composite generation and transmission system reliability studies, and their associated probability distributions. This paper examines the effects of load forecast uncertainty in bulk system reliability assessment incorporating changes in system composition, topology, load curtailment policies and bus load correlation levels.
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Effects of Load Forecast Uncertainty on Bulk Electric System Reliability Evaluation
IEEE Transactions on Power Systems, 2008Co-Authors: R Billinton, Dange HuangAbstract:Load forecast uncertainty is an important factor in long-range system planning and has been shown to have a significant impact on the calculated reliability indices in generating Capacity studies. In general, a higher Capacity Reserve is required to satisfy a future uncertainty load than to serve a known load, at a specified level of reliability. Load forecast considerations are also important in composite generation and transmission system reliability studies, and their associated probability distributions. This paper examines the effects of load forecast uncertainty in bulk system reliability assessment incorporating changes in system composition, topology, load curtailment policies and bus load correlation levels.
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application of monte carlo simulation to generating system well being analysis
IEEE Transactions on Power Systems, 1999Co-Authors: R Billinton, Rajesh KarkiAbstract:System well-being analysis is a new approach to power system generation adequacy evaluation which incorporates deterministic criteria in a probabilistic framework and provides system operating information in addition to risk assessment. This approach not only provides a new perspective to generation adequacy studies but can also be useful in those situations in which conventional probabilistic techniques are not normally accepted, such as, in system operating Capacity Reserve assessment and in small isolated system planning. The probabilities of system health, margin and risk are the basic well-being indices and can be evaluated using analytical techniques. Monte Carlo simulation can also be used to estimate the indices by simulating the actual process and random behavior of the system and can include system effects which may not be possible without excessive approximation in a direct analytical approach. This paper illustrates the utilization of Monte Carlo simulation to evaluate additional well-being indices and their distributions and the significance of this additional information on Capacity Reserve evaluation.
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Capacity Reserve assessment using system well-being analysis
IEEE Transactions on Power Systems, 1999Co-Authors: R Billinton, Rajesh KarkiAbstract:Deterministic methods are widely used in operating Reserve assessment and in small isolated power system Capacity planning. These approaches do not normally include any explicit recognition of system risk and do not provide comparable risks for systems of different size or composition. Many large power systems, therefore, use probabilistic methods for generation adequacy evaluation. The reluctance to utilize the existing probabilistic techniques in both large and small systems dictates a need to create a bridge between the two different approaches. This paper presents a new probabilistic method designated as 'system well-being analysis', which incorporates the accepted deterministic criteria in the definition of 'healthy' and 'marginal' power system states. This paper illustrates methodologies to evaluate the system well-being indices of practical systems and describes how they can be used in the assessment of power system Capacity Reserves.
Tingting Liu - One of the best experts on this subject based on the ideXlab platform.
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A Multiple Response-Based Structural Capacity Reserve Assessment Model for Long-Span Single-Layer Lattice Shells under Strong Earthquakes
Journal of Earthquake Engineering, 2019Co-Authors: Tingting LiuAbstract:A new structural Capacity Reserve (SCR) model is proposed based on the selected response-based indicators for single-layer lattice shells. The modified residual seismic Capacity ratio is defined as...
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Structural-Capacity-Reserve-based performance assessment of long-span single-layer lattice shell structures
Journal of Constructional Steel Research, 2019Co-Authors: Tingting LiuAbstract:Abstract To achieve a well-balanced structural design, a customized performance assessment approach based on the structural Capacity Reserve (SCR) is proposed for commonly used long-span single-layer lattice shells. The SCR is calculated by integrating the normalized residual seismic Capacity (RSC) over the entire range of possible earthquake-induced damage levels. Six typical RSC ratio curves and the corresponding ranges of the SCR index are discussed and verified for several spherical single-layer lattice shells. The impact of the arrangement of the components on the structural deformability, failure mode, plasticity and damage development as well as the RSC and SCR is clarified for two Schwedler shells. Based on observations from vulnerability and sensitivity analyses, several alternative strengthening schemes are generated for an S12 Schwedler single-layer lattice shell, and the optimal one is determined by means of a multiple-objective evaluation system that includes the SCR. The investigation indicates that normalized RSC ratio curves can reflect the design rationality of structural layouts and that they can clearly capture the dynamic instability of lattice shells. The ability of lattice shells to retain their post-earthquake resistance Reserves is found to depend primarily on the locations where damage develops. The localization of fully yielded components has the potential to create several weak regions, leading to a high possibility of substantial loss of resistance Reserves. The case study of the S12 Schwedler shell demonstrates the necessity of considering the SCR in a comprehensive structural performance evaluation system.
Rajesh Karki - One of the best experts on this subject based on the ideXlab platform.
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application of monte carlo simulation to generating system well being analysis
IEEE Transactions on Power Systems, 1999Co-Authors: R Billinton, Rajesh KarkiAbstract:System well-being analysis is a new approach to power system generation adequacy evaluation which incorporates deterministic criteria in a probabilistic framework and provides system operating information in addition to risk assessment. This approach not only provides a new perspective to generation adequacy studies but can also be useful in those situations in which conventional probabilistic techniques are not normally accepted, such as, in system operating Capacity Reserve assessment and in small isolated system planning. The probabilities of system health, margin and risk are the basic well-being indices and can be evaluated using analytical techniques. Monte Carlo simulation can also be used to estimate the indices by simulating the actual process and random behavior of the system and can include system effects which may not be possible without excessive approximation in a direct analytical approach. This paper illustrates the utilization of Monte Carlo simulation to evaluate additional well-being indices and their distributions and the significance of this additional information on Capacity Reserve evaluation.
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Capacity Reserve assessment using system well-being analysis
IEEE Transactions on Power Systems, 1999Co-Authors: R Billinton, Rajesh KarkiAbstract:Deterministic methods are widely used in operating Reserve assessment and in small isolated power system Capacity planning. These approaches do not normally include any explicit recognition of system risk and do not provide comparable risks for systems of different size or composition. Many large power systems, therefore, use probabilistic methods for generation adequacy evaluation. The reluctance to utilize the existing probabilistic techniques in both large and small systems dictates a need to create a bridge between the two different approaches. This paper presents a new probabilistic method designated as 'system well-being analysis', which incorporates the accepted deterministic criteria in the definition of 'healthy' and 'marginal' power system states. This paper illustrates methodologies to evaluate the system well-being indices of practical systems and describes how they can be used in the assessment of power system Capacity Reserves.
Anthony M. J. Bull - One of the best experts on this subject based on the ideXlab platform.
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age related compensation neuromusculoskeletal Capacity Reserve movement objectives
Journal of Biomechanics, 2021Co-Authors: Eline Van Der Kruk, Anne K. Silverman, Peter Reilly, Louis Koizia, Michael Fertleman, Anthony M. J. BullAbstract:Abstract The prevention, mitigation and treatment of movement impairments, ideally, requires early diagnosis or identification. As the human movement system has physiological and functional redundancy, movement limitations do not promptly arise at the onset of physical decline. A such, prediction of movement limitations is complex: it is unclear how much decline can be tolerated before movement limitations start. Currently, the term ‘homeostatic Reserve’ or ‘physiological Reserve’ is used to refer to the redundancy of the human biological system, but these terms do not describe the redundancy in the muscle architecture of the human body. The result of functional redundancy is compensation. Although compensation is an early predictor of movement limitations, clear definitions are lacking and the topic is underexposed in literature. The aim of this article is to provide a definition of compensation and emphasize its importance. Compensation is defined as an alteration in the movement trajectory and/or altering muscle recruitment to complete a movement task. Compensation for Capacity is the result of a lack in neuromusculoskeletal Reserve, where Reserve is defined as the difference between the Capacity (physiological abilities of the neuromusculoskeletal system) and the task demand. Compensation for movement objectives is a result of a shift in weighting of movement objectives, reflecting changing priorities. Studying compensation in biomechanics requires altered protocols in experimental set-ups, musculoskeletal models that are not reliant on prescribed movement, and inclusion of alternative movement objectives in optimal control theory.
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The Effect of Ageing on the Standing Up Movement Analysed using the Capacity, Reserve, Movement Objectives, and Compensation (CaReMoOC) Framework
2020Co-Authors: Eline Van Der Kruk, Anne K. Silverman, Peter Reilly, Anthony M. J. BullAbstract:In healthy ageing, Capacity declines in the neural, muscular, and skeletal systems, and each system decline has its effect on the execution of complex motor tasks. This decline in Capacity can result in the inability to stand up (sit-to-stand, sit-to-walk), which is a key movement for independence. The mechanisms leading to mobility limitations or inabilities are complex, overlapping, and interdependent and the complementary fields of biomechanics, motor control, and physiology need to be combined to understand these mechanisms. The aim of this review is to provide an overview of the current knowledge of age-related compensation in standing up and to consider the limitations of these results when analysing standing up in daily life using the Capacity, Reserve, Movement Objectives, and Compensation (CaReMoOC) framework that combines biomechanics, motor control, and physiology. A literature search was performed in the search engine Scopus, using the keywords and their synonyms: strateg*(approach, technique, way) AND, sit-to-walk OR sit-to-stand OR rise (raise, arise, stand, stand-up) AND chair (seat). Inclusion criteria were: biomechanics or motor control on sit-to-stand or sit-to-walk in healthy and/or frail adults (<60y) and elderly (>60y), and/or osteoarthritis patients as a specific case of ageing related decline. The review shows that movement compensations in standing up manifest as changes in planned trajectory (Compensation by Selection) and in muscle recruitment (Compensation by Reorganisation). However, as most studies in the literature typically use standardized experimental protocols where movement compensation is restricted, these studies cannot be directly translated to functional tasks, such as the mobility of the elderly in their homes, communities, and clinic. Compensation must be included in future studies in order to facilitate clinical translation. Specifically, future studies in the standing up task should 1) determine the effect of varying arm use strategies (e.g., armrests, knees, chair, cane) on trunk and both lower limb and upper limb joint loading, 2) analyse control strategies in elderly people, 3) determine the biomechanical implications of asymmetry, and 4) incorporate assessments of age-related physical and neural decline as well as changes in psychological priorities.
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CaReMoOC: Capacity, Reserve, Movement Objectives, and Compensation. A Proposed Framework to Describe Mechanisms of Movement Limitations, Demonstrated for Ageing
2020Co-Authors: Eline Van Der Kruk, Anne K. Silverman, Peter Reilly, Louis Koizia, Michael Fertleman, Anthony M. J. BullAbstract:To prevent, mitigate and treat movement impairments, we need to recognize early signs of decline and understand how to best compensate for limitations. The mechanisms leading to movement impairments are complex, overlapping, and interdependent and the fields of biomechanics, motor control, and physiology must be combined to understand these mechanisms. This article introduces CaReMoOC, a framework incorporating neuromusculoskeletal Capacity (accumulation of neuromusculoskeletal resources over the lifespan), Reserve (task-specific difference between Capacity and task demand), movement objectives (considerations made to plan a movement), and compensation (use of NMSK resources to respond to the task demand). The framework is demonstrated for healthy ageing, providing an overview of age-related Capacity decline (neural, skeletal, muscular system) and shifted weighting of movement objectives (energy, pain, stability, speed) relevant for biomechanics and motor control. Two forms of compensation are Compensation for Capacity, when Capacity does not meet the task demands, and Compensation for Movement Objectives, when the movement is changed due to for example a fear of falling. Understanding the interrelationships between decline in the variables within Capacity and the effect on compensation strategies will provide benefit in preventing mobility impairments and will support clinicians in their rehabilitation practice.
Keith R. Long - One of the best experts on this subject based on the ideXlab platform.
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A Test and Re-Estimation of Taylor’s Empirical Capacity–Reserve Relationship
Natural Resources Research, 2009Co-Authors: Keith R. LongAbstract:In 1977, Taylor proposed a constant elasticity model relating Capacity choice in mines to Reserves. A test of this model using a very large ( n = 1,195) dataset confirms its validity but obtains significantly different estimated values for the model coefficients. Capacity is somewhat inelastic with respect to Reserves, with an elasticity of 0.65 estimated for open-pit plus block-cave underground mines and 0.56 for all other underground mines. These new estimates should be useful for Capacity determinations as scoping studies and as a starting point for feasibility studies. The results are robust over a wide range of deposit types, deposit sizes, and time, consistent with physical constraints on mine Capacity that are largely independent of technology.
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A Test and Re-Estimation of Taylor’s Empirical Capacity-Reserve Relationship
Natural Resources Research, 2009Co-Authors: Keith R. LongAbstract:In 1977, Taylor proposed a constant elasticity model relating Capacity choice in mines to Reserves. A test of this model using a very large (n = 1,195) dataset confirms its validity but obtains significantly different estimated values for the model coefficients. Capacity is somewhat inelastic with respect to Reserves, with an elasticity of 0.65 estimated for open-pit plus block-cave underground mines and 0.56 for all other underground mines. These new estimates should be useful for Capacity determinations as scoping studies and as a starting point for feasibility studies. The results are robust over a wide range of deposit types, deposit sizes, and time, consistent with physical constraints on mine Capacity that are largely independent of technology.
