Reliability Benefits Research Articles

Leveraging older adults' susceptibility to distraction to improve memory for face-name associations.

Forgetting people's names is a common memory complaint among older adults and one that is consistent with experimental evidence of age-related decline in memory for face-name associations. Despite this difficulty intentionally forming face-name associations, a recent study demonstrated that older adults hyperbind distracting names and attended faces, which produces better learning of these face-name pairs when they reappear on a memory test (Weeks, Biss, Murphy, & Hasher, 2016). The current study explored whether this effect could be leveraged as an intervention to reduce older adults' forgetting of face-name associations, using a method previously shown to improve older adults' retention of a word list (Biss, Ngo, Hasher, Campbell, & Rowe, 2013). Twenty-five younger and 32 older adults studied 24 face-name pairs and were tested via immediate and delayed memory tests. During the 30-min retention interval, 10 of the face-name pairs reoccurred as distraction in an ostensibly unrelated face-judgment task, providing an opportunity to implicitly rehearse these pairs. Older adults showed reduced forgetting of repeated face-name pairs as well as improved recollection. Younger adults showed no reliable benefit. These findings indicate that useful distraction benefits older adults' memory for face-name associations, suggesting its potential utility as a memory intervention technique. (PsycINFO Database Record

Optimal Reconstruction of Power Distribution Network based on Reliability and Economy

Great significance shall be attached to the research on how to improve reliability of user-end power supply with limited expense by coordinating reliability and economic efficiency of power grid, so that to meet the increasing demand on reliability of electric power, and achieve considerable economic effectiveness. In this paper, process of power distribution network reliability calculation based on minimum-path failure mode and effect analysis mode is expounded, and a demonstration on calculation of power distribution network reliability is provided. Furthermore, cost-benefit analysis, which includes calculations of cost and benefit of reliability, is introduced to reflect reliability efficiency through power interruption cost calculation. At the end of this paper the cost-benefit Analyses is applied on the optimal reconstructed power distribution network.

Evaluating Demand Response Impacts on Capacity Credit of Renewable Distributed Generation in Smart Distribution Systems

Environmental concerns and depletion of traditional energy lead to the booming development of renewable distributed generation (RDG) in the past decade. However, due to intermittent nature of renewable energy sources, to what extent RDG could provide capacity to power systems becomes a critical issue to the utility company when implementing long-term system strategic (generation expansion) planning. On the other hand, in a smart-grid frame, the popularization of different varieties of demand-side resources enables the system to operate at more flexible modes ever before. The potential variability in load demand not only introduces additional dynamics and uncertainties to the system, but could also affect the reliability benefits of RDG. Therefore, in practice, to effectively estimate the reliability value of RDG in power systems, the potential interaction between generation- and demand-side must be properly captured. In this paper, a study to assess the capacity credit (CC) of RDG in a context of distributed generation system is performed with consideration of the impacts of demand response (DR). A compound reliability model for DR is presented, which considers the uncertainties involved in both instant response and follow-on load recovery processes. On this basis, an assessment framework for the CC of RDG based on sequential Monte Carlo simulation is developed by which the inter-temporal characteristics of DR resources can be fully captured. The numerical study is implemented based on the IEEE-38 bus test case. The calculation results demonstrate that the CC of RDG would depend on a variety of factors, including penetration level, responsiveness of load demand and the correlations between RDG and DR availability. Also, it is shown that accounting for the underlying effect of DR is of absolute importance, otherwise the CC of RDG might be estimated erroneously in real practices.

Optimal sizing of flexible nuclear hybrid energy system components considering wind volatility

This paper seeks to quantify the benefits of a flexible energy system in the context of enabling higher levels of variable renewable energy on the grid. We explore a nuclear hybrid energy system (NHES) consisting of a 300 MW small modular reactor, wind generation, battery storage, and a reverse osmosis desalination plant. A dispatch rule is constructed within the Risk Analysis Virtual Environment (RAVEN) to model the system. Stochastic optimization and parametric analysis are utilized to explore how increased volatility in the net demand resulting from higher levels of wind penetration affect the optimal solution, and the stability of the system’s levelized cost of electricity (LCOE). In this study, net demand is the demand minus wind generation. This work contributes multi-objective analysis implemented through a supply-demand mismatch penalty to illustrate the financial stability and operational reliability benefits of the flexible energy system. In this context, we find that the additional up front cost of flexible loads and energy storage result in greater stability in LCOE as volatility in the demand increases. Additionally, the flexibility results in increased reliability in terms of meeting the demand. Although the analysis is conducted on a NHES, we emphasize the flexibility of the method applied here, in that the RAVEN platform and the multi-objective strategy are widely applicable to the analysis of energy systems faced with uncertainties in supply and demand.

Simple eye-movement feedback during visual search is not helpful

Searching for targets in the visual world, or visual search, is something we all do every day. We frequently make ‘false-negative’ errors, wherein we erroneously conclude a target was absent when one was, in fact, present. These sorts of errors can have tremendous costs, as when signs of cancers are missed in diagnostic radiology. Prior research has characterized the cause of many of these errors as being due to failure to completely search the area where targets may be present; indeed, roughly one-third of chest nodules missed in lung cancer screening are never fixated (Drew, Võ, Olwal, Jacobson, Seltzer and Wolfe, Journal of Vision 13:3, 2013). This suggests that observers do not have a good representation of what areas have and have not been searched prior to declaring an area target free. Therefore, in six experiments, we sought to examine the utility of reducing the uncertainty with respect to what areas had been examined via online eye-tracking feedback. We hypothesized that providing information about what areas had or had not been examined would lead to lower rates of false negatives or more efficient search, namely faster response times with no cost on target detection accuracy. Neither of these predictions held true. Over six experiments, online eye-tracking feedback did not yield any reliable performance benefits.

Time to Adopt New Measures of Severe Obesity in Children and Adolescents.

* Abbreviations: ΔBMIp95 — : BMI minus BMI at the 95th percentile BMIp95 — : BMI as a percent of the 95th percentile BMIz — : BMI z score CDC — : Centers for Disease Control and Prevention The ideal measure of weight gain and loss should distinguish children and adolescents across the distribution of weight and height and should include the capacity for changes in weight adjusted for height over time. Over short intervals, in which there is little growth in height, absolute changes in weight or BMI provide suitable indicators of weight gain or loss. However, over longer intervals, during which height increases significantly, weight change must be adjusted for changes in height and age by sex. BMI, which is calculated as weight (in kg) divided by the square of height (in m2), adjusts body weight for height. Although the correlation of BMI with various measures of body fat percentage is modest across the distribution of BMI, the correlation of BMI with body fat improves at the upper part of the body fat distribution. Increases in BMI greater than the 95th percentile are associated with increases in body fat.1,2 In addition, BMI has benefits in feasibility, reliability, and measurement and clinical validity.3 Changes in BMI, BMI percentiles, or changes in BMI expressed as an SD score (BMI z score [BMIz]) provide a reasonably … Address correspondence to William H. Dietz, MD, PhD, George Washington University, Sumner M. Redstone Global Center for Prevention and Wellness, 950 New Hampshire Ave, NW, Washington, DC 20052. E-mail: dietzwcd4{at}gmail.com

Sustainable Low-Carbon Expansion for the Power Sector of an Emerging Economy: The Case of Kenya.

Fast growing and emerging economies face the dual challenge of sustainably expanding and improving their energy supply and reliability while at the same time reducing poverty. Critical to such transformation is to provide affordable and sustainable access to electricity. We use the capacity expansion model SWITCH to explore low carbon development pathways for the Kenyan power sector under a set of plausible scenarios for fast growing economies that include uncertainty in load projections, capital costs, operational performance, and technology and environmental policies. In addition to an aggressive and needed expansion of overall supply, the Kenyan power system presents a unique transition from one basal renewable resource-hydropower-to another based on geothermal and wind power for ∼90% of total capacity. We find geothermal resource adoption is more sensitive to operational degradation than high capital costs, which suggests an emphasis on ongoing maintenance subsidies rather than upfront capital cost subsidies. We also find that a cost-effective and viable suite of solutions includes availability of storage, diesel engines, and transmission expansion to provide flexibility to enable up to 50% of wind power penetration. In an already low-carbon system, typical externality pricing for CO2 has little to no effect on technology choice. Consequently, a "zero carbon emissions" by 2030 scenario is possible with only moderate levelized cost increases of between $3 and $7/MWh with a number of social and reliability benefits. Our results suggest that fast growing and emerging economies could benefit by incentivizing anticipated strategic transmission expansion. Existing and new diesel and natural gas capacity can play an important role to provide flexibility and meet peak demand in specific hours without a significant increase in carbon emissions, although more research is required for other pollutant's impacts.

Evidence for improved memory from 5\xa0minutes of immediate, post-encoding exercise among women

Memories consolidate over time, with one consequence being that what we experience after learning can influence what we remember. In these experiments, women who engaged in 5 minutes of low-impact exercise immediately after learning showed better recall for paired associations than did women who engaged in a non-exercise control activity. In experiments 1 and 2, this benefit was apparent in a direct comparison between exercise and non-exercise groups. In experiment 3, it was reflected in a weak, positive correlation between memory performance and exercise-induced change in heart rate. In experiment 4, similar patterns emerged, although they fell short of statistical significance. Such memorial benefits did not emerge among male participants. In experiment 1, half the participants alternatively engaged in an equivalent period of exercise prior to learning, with no benefits for retention of the learned material, suggesting that the memorial benefits of exercise-induced arousal may reflect a specific impact on post-learning processes such as memory consolidation. A meta-analysis across the experiments revealed a reliable benefit of post-learning exercise among women. Variation in the strength of the effect between experiments is consistent with a literature suggesting small but reliable benefits of acute exercise on cognitive performance.

Extended warranty strategies for online shopping supply chain with competing suppliers considering component reliability

This article presents the issue of extended warranty and management strategies in a three-echelon competing online shopping supply chain with price- and base warranty period-dependent demand. We employ game theory to develop decision models to explore the interactions between component suppliers and the manufacturer, as well as competition between two component suppliers. Products and extended warranty are sold by an online store, which is the leader in the Stackelberg game. Two scenarios are considered: either the manufacturer offers a prepaid extended warranty to customers or doses not. In each scenario, base warranties are assumed to be bundled with products. Our results show that when the manufacturer’s repair costs change in a proper range, providing extended warranty can benefit both the manufacturer and the online store; otherwise, the manufacturer has no incentive to offer the extended warranty. Reducing repair costs, improving component reliability, or shortening the base warranty period allows the manufacturer to realize significantly better value of the extended warranty. High component reliability benefits both the manufacturer and the online store, with the manufacturer reaping more benefit. Extending the length of the base warranty adversely affects profit of the manufacturer and the value of the extended warranty.

Optimising patient outcomes with photoselective vaporization of the prostate (PVP): a review.

Benign prostatic hyperplasia (BPH) is a common pathology causing lower urinary tract symptoms (LUTS) and may significantly impact quality of life. While transurethral resection of the prostate (TURP) remains the gold standard treatment, there are many evolving technologies that are gaining popularity. Photoselective vaporization of the prostate (PVP) is one such therapy which has been shown to be non-inferior to TURP. We aimed to review the literature and discuss factors to optimise patient outcomes in the setting of PVP for BPH. A comprehensive search of the electronic databases, including MEDLINE, Embase, Web of Science and The Cochrane Library was performed on articles published after the year 2000. After exclusion, a total of 38 papers were included for review. The evolution of higher powered device has enabled men with larger prostates and those on oral anticoagulation to undergo safely and successfully PVP. Despite continued oral anticoagulation in patients undergoing PVP, the risk of bleeding may be minimised with 5-Alpha Reductase Inhibitor (5-ARI) therapy however further studies are required. Pre-treatment with 5-ARI’s does not hinder the procedure however more studies are required to demonstrate a reliable benefit. Current data suggests that success and complication rate is largely influenced by the experience of the operator. Post-operative erectile dysfunction is reported in patients with previously normal function following PVP, however those with a degree of erectile dysfunction pre-operatively may see improvement with alleviation of LUTS.

An agent-based model of building occupant behavior during load shedding

Load shedding enjoys increasing popularity as a way to reduce power consumption in buildings during hours of peak demand on the electricity grid. This practice has well known cost saving and reliability benefits for the grid, and the contracts utilities sign with their “interruptible” customers often pass on substantial electricity cost savings to participants. Less well-studied are the impacts of load shedding on building occupants, hence this study investigates those impacts on occupant comfort and adaptive behaviors. It documents experience in two office buildings located near Philadelphia (USA) that vary in terms of controllability and the set of adaptive actions available to occupants. An agent-based model (ABM) framework generalizes the case-study insights in a “what-if” format to support operational decision making by building managers and tenants. The framework, implemented in EnergyPlus and NetLogo, simulates occupants that have heterogeneous thermal and lighting preferences. The simulated occupants pursue local adaptive actions such as adjusting clothing or using portable fans when central building controls are not responsive, and experience organizational constraints, including a corporate dress code and miscommunication with building managers. The model predicts occupant decisions to act fairly well but has limited ability to predict which specific adaptive actions occupants will select.

Cognitive effects of a 30-min aerobic exercise bout on adults with overweight/obesity and type 2 diabetes.

SummaryBackgroundSeveral studies document reliable brain health benefits of acute exercise bouts. However, no prior studies have explored such effects among those living with co‐morbid overweight/obesity and type 2 diabetes (T2DM), both of which are conditions associated with cognitive performance decrements.PurposeTo examine the impact of a 30‐min bout of moderate‐intensity aerobic exercise on executive function among adults with overweight/obesity and T2DM, employing a widely used experimental paradigm.MethodsThirty adults with overweight/obesity and T2DM were randomly assigned to moderate (30% maximal heart rate reserve) and minimal (r.p.m. 30–50; work load 5) intensity aerobic exercise. Pre‐exercise to post‐exercise changes in Stroop interference and Go/No‐Go scores were compared across conditions.ResultsPrimary analyses revealed no overall effect of exercise condition on changes in Stroop or Go/No‐Go performance. Post‐hoc moderation analyses indicated that Stroop interference scores were reduced, following moderate exercise among female participants and among those who were more physically active.ConclusionThe current study revealed no reliable benefit of acute aerobic exercise for overweight and obese individuals living with T2DM overall. There may be limited benefits for women and more and active subgroups, but the precise nature of such benefits remains unclear.

The importance of acknowledgement of emotions in routine patient psychological assessment: The example of the dental setting

ObjectiveTo investigate, by means of a conceptual model, the effect of dental staff engaging with their patients who share their level of dental anxiety in a short screening questionnaire. Methods: Three consecutive studies based in the UK primary dental care services were conducted. Each study adopted a randomised group design to focus on the possible influence on patient state anxiety of the dentist becoming aware of their patients’ dental anxiety from the self-reports of the Modified Dental Anxiety Scale (MDAS). ResultsA consistent finding in the first two studies was that the presentation of MDAS score sheet to the dentist was effective in reducing patient state anxiety when leaving the surgery. The third study provided supportive evidence that a more permanent anxiolytic effect of the presentation of the MDAS to the dentist was associated with the dentist responding openly to their patient about the fears expressed. ConclusionThe active engagement of dental staff in the formal presentation of dental anxiety screening confers a reliable benefit to dentally anxious patients. Clinical implicationsAnxiety assessments in clinical service may give patients significant relief when staff acknowledge and engage patients when presented with their self-reported ratings.

Finite‐control‐set model predictive control scheme of three‐phase four‐leg back‐to‐back converter‐fed induction motor drive

The three-phase four-leg back-to-back converter-fed induction motor drive with only eight switches has the capability of variable-frequency speed control and bidirectional power flow. It can provide the benefit of higher reliability and less cost in comparison with the full-bridge back-to-back converter. On the other hand, the four-leg back-to-back converter can be utilised in fault-tolerant control to solve open-circuit fault occurring at both rectifier and inverter leg in a full-bridge back-to-back converter. However, the deviation of the two capacitor voltages which will lead to variation of voltage vectors in both amplitude and phase angle hinders its applications. This study proposes a control scheme based on finite-control-set model predictive control to remedy this disadvantage. With the proposed scheme, capacitor voltage deviation is suppressed. Bidirectional power flows and balanced input and output currents are achieved. The effectiveness of the proposed scheme is verified by the experimental results presented.

Multistage Robust Unit Commitment With Dynamic Uncertainty Sets and Energy Storage

The deep penetration of wind and solar power is a critical component of the future power grid. However, the intermittency and stochasticity of these renewable resources bring significant challenges to the reliable and economic operation of power systems. Motivated by these challenges, we present a multistage adaptive robust optimization model for the unit commitment (UC) problem, which models the sequential nature of the dispatch process and utilizes a new type of dynamic uncertainty sets to capture the temporal and spatial correlations of wind and solar power. The model also considers the operation of energy storage devices. We propose a simplified and effective affine policy for dispatch decisions, and develop an efficient algorithmic framework using a combination of constraint generation and duality-based reformulation with various improvements. Extensive computational experiments show that the proposed method can efficiently solve multistage robust UC problems on the Polish 2736-bus system under high dimensional uncertainty of 60 wind farms and 30 solar farms. The computational results also suggest that the proposed model leads to significant benefits in both costs and reliability over robust models with traditional uncertainty sets as well as deterministic models with reserve rules.

Energy-Aware Memory Mapping for Hybrid FRAM-SRAM MCUs in Intermittently-Powered IoT Devices

Forecasts project that by 2020, there will be around 50 billion devices connected to the Internet of Things (IoT), most of which will operate untethered and unplugged. While environmental energy harvesting is a promising solution to power these IoT edge devices, it introduces new complexities due to the unreliable nature of ambient energy sources. In the presence of an unreliable power supply, frequent checkpointing of the system state becomes imperative, and recent research has proposed the concept of in-situ checkpointing by using ferroelectric RAM (FRAM), an emerging non-volatile memory technology, as unified memory in these systems. Even though an entirely FRAM-based solution provides reliability, it is energy inefficient compared to SRAM due to the higher access latency of FRAM. On the other hand, an entirely SRAM-based solution is highly energy efficient but is unreliable in the face of power loss. This paper advocates an intermediate approach in hybrid FRAM-SRAM microcontrollers that involves judicious memory mapping of program sections to retain the reliability benefits provided by FRAM while performing almost as efficiently as an SRAM-based system. We propose an energy-aware memory mapping technique that maps different program sections to the hybrid FRAM-SRAM microcontroller such that energy consumption is minimized without sacrificing reliability. Our technique consists of eM-map , which performs a one-time characterization to find the optimal memory map for the functions that constitute a program and energy-align , a novel hardware-software technique that aligns the system’s powered-on time intervals to function execution boundaries, which results in further improvements in energy efficiency and performance. Experimental results obtained using the MSP430FR5739 microcontroller demonstrate a significant performance improvement of up to 2x and energy reduction of up to 20% over a state-of-the-art FRAM-based solution. Finally, we present a case study that shows the implementation of our techniques in the context of a real IoT application.

An assessment of flexibility reserves in stochastic modeling at multiple timescales

Due to recent technological achievements, stochastic optimization, which inherently captures the uncertainty of intermittent resources, is being used to capture the variability and uncertainty of wind and solar resources. However, due to persistent computational limitations, it is not practical to consider all possible variable generation scenarios. As a result, a reduced number of most likely scenarios is usually considered. While this helps reduce the computational burden, it also leaves the system operator vulnerable to some risk. In order to address this issue, this paper aims at providing insight into using an explicit reserve requirement in a stochastic modeling framework in order to provide system operators with greater confidence in stochastic dispatch solutions. This is accomplished by simulating a modified version of the IEEE 118 bus system in a fully stochastic, multi-timescale framework with flexibility reserve requirements. Results show that utilizing a stochastic flexibility reserve requirement within the stochastic modeling framework offers the most reliability benefit.

Valuing Water Supply Reliability with Sensitivity Analysis

The purpose of this paper is to calculate the expected reliability benefits of alternative water supplies that are less vulnerable to disruption than the current composition of supplies, especially those regions which rely on imported surface water. Expected reliability benefits are measured using estimates of welfare losses under various levels of supply disruption, the probability of each level disruption, and on consumption forecasts over the life of proposed alternative supplies. To consider uncertainty in reliability benefits, we run sensitivity analyses to value reliability under different discount rates, the elasticities of demand, water supply disruption levels, and corresponding probability distributions of disruption.

Improved Litz wire manufacture process using resonant power converter-based induction heating

PurposeLitz wire manufacturing using mechanical procedures presents several limitations regarding reliability and repeatability, especially when a small strand diameter is used. This paper aims to propose a power supply design for Litz wire manufacturing using a high-frequency high-performance resonant converter.Design/methodology/approachThis paper proposes the design of a resonant power supply for induction heating specially designed to tackle with the challenge of heating Litz wires quickly.FindingsThe proposed converter enables the removal of the isolating coating from the Litz wire through induction heating, improving significantly the manufacturing process.Originality/valueThe proposed converter improves significantly the manufacturing process of Litz wire through induction heating, with economic and reliability benefits.

Abstract P2-09-06: Addition of ovarian function suppression to endocrine therapy in premenopausal women with early breast cancer: A meta-analysis

Abstract Introduction The Suppression of Ovarian Function Trial (SOFT) and the Tamoxifen and EXemestane Trial (TEXT), together with the Austrian Breast Cancer Study Group (ABCSG-12)and the Eastern Cooperative Oncology Group 3193 (E-3193 trials, have examined adding ovarian function suppression (OFS) using gonadotropin–releasing hormone (GnRH) agonists to endocrine therapy in premenopausal women with early stage breast cancer. However, OFS with GnRH agonist plus aromatase inhibitor has subsequently been found to not consistently reduce estradiol levels to optimal target in the SOFT-EST study (JCO 2016; 34:1584) and implications of these study findings for clinical practice are controversial. Therefore, to further examine this issue, we conducted a systematic literature review and meta-analysis of available evidence. Methods We updated a recently published literature review of randomized clinical trials (JCO 2016; 34:1689) through June 1, 2016 using the keywords “breast cancer,” “ovarian function suppression,” “tamoxifen,” and “aromatase inhibitor”. Of 683 of records identified through database searching, the 4 studies named above met inclusion criteria and were included in the quantitative synthesis. Information on disease-free survival (DFS) and overall survival was examined using hazard ratio (HR) and 95% confidence interval (CI). Because of significant heterogeneity in one performed meta-analyses, the random-effects (DerSimonian and Laird) method was used to estimate the combined RR for studies (Open MetaAnalyst). Results Combining ABCSG-12, SOFT and TEXT trial findings, OFS addition to aromatase inhibitor resulted in 65 fewer DFS events across the 3 trials compared to OFS addition to tamoxifen (350 DFS events vs. 415 DFS events, respectively, HR 0.89, 95% CI 0.57-1.39, P=0.62, Tau2 =0.09, heterogeneity P<0.01). In contrast, 30 more deaths were seen with OFS plus aromatase inhibitor use (155 deaths vs. 125 deaths, respectively, HR 1.31, 95% CI 0.93 -1.84, P=0.12, Tau2 =0.03, heterogeneity P=0.18). Combining SOFT and E-3193 trials to compare OFS addition to tamoxifen to tamoxifen alone use, more concordance between DFS events and overall survival is seen. There were 24 fewer DFS events across the 2 trials with OFS addition to tamoxifen compared to tamoxifen alone (160 DFS events vs. 184 DFS events, respectively, HR 0.83, 95% CI 0.67-1.03, P=0.09, Tau2 =0, heterogeneity P=0.94) and there were 14 fewer deaths in the OFS plus tamoxifen compared to tamoxifen alone group (58 deaths vs. 72 deaths, respectively, HR 0.76 95% CI 0.53 -1.07, P=0.12, Tau2 =0, heterogeneity P=0.78). Conclusion In conclusion, the apparent discordance between DFS and overall survival in the aromatase inhibitor and OFS trials and the results suggesting incomplete and/or intermittent estrogen suppression with GNRH analogs in the SOFT-EST trial suggest that adoption of OFS plus aromatase inhibitor use as adjuvant therapy in premenopausal women with early stage breast cancer may be premature. Longer term survival analyses of the endocrine therapy trials are needed before reliable risks and benefits of aromatase inhibitor plus OFS and tamoxifen plus OFS use as adjuvant therapy can be determined. Citation Format: Chlebowski R, Pan K, Col NF. Addition of ovarian function suppression to endocrine therapy in premenopausal women with early breast cancer: A meta-analysis [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P2-09-06.