scholarly journals Risk Assessment for the Power Grid Dispatching Process Considering the Impact of Cyber Systems

Energies ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 1084 ◽  
Author(s):  
Biyun Chen ◽  
Haoying Chen ◽  
Yiyi Zhang ◽  
Junhui Zhao ◽  
Emad Manla

Power grid dispatching is a high-risk process, and its execution depends on an available cyber system. However, the effects of cyber systems have not caught enough attention in current research on risk assessments in dispatching processes, which may cause optimistic risk results. In order to solve this problem, this paper proposes a risk assessment model that considers the impact of a cyber system on power grid dispatching processes. Firstly, a cyber-physical switchgear state model that integrates the reliability states of both cyber system functions and switchgears is proposed, based on the transition of switchgear states in the dispatching process. Then, the potential effects of each operating step on power grid states are analyzed considering the failure model of cyber-physical system (CPS) components. The risk probabilities and consequences of the power grid states are calculated to quantify the risk index. Finally, the workings and effectiveness of this model are illustrated using the IEEE Reliability Test System-1979.

Author(s):  
Xiaosheng Wang ◽  
Wei Li ◽  
Haiying Guo ◽  
Ran Li

Abstract As a novel market-based water-saving mechanism, the Water Saving Management Contract (WSMC) project faces interruption risk caused by emergencies like the coronavirus disease-2019 (COVID-19) pandemic. An interruption risk assessment model of WSMC projects is established through a quantitative evaluation of the impact of emergencies on water users based on input-output theory. First, the concept of the interruption risk index (IRI) is defined as a function of the duration of enterprise shutdown (DES). Second, the DES is divided into two parts: the duration caused by COVID-19 and the that under other types of emergencies. Third, the risk tolerance threshold is given to estimate the interruption result, and its different consequences are discussed. Finally, a WSMC project in China is taken as a case study, and its interruption risks are analysed. The results show that the IRIs of this WSMC in both 2020 and 2021 are theoretically greater than the risk tolerance thresholds, and the high pandemic prevention standards and conservative pandemic estimates are the main reasons for the above results. The model established in this study provides a reference for WSMC participants to deal with emergencies and provides the theoretical support for the extension of the WSMC.


Author(s):  
Grant Duwe

As the use of risk assessments for correctional populations has grown, so has concern that these instruments exacerbate existing racial and ethnic disparities. While much of the attention arising from this concern has focused on how algorithms are designed, relatively little consideration has been given to how risk assessments are used. To this end, the present study tests whether application of the risk principle would help preserve predictive accuracy while, at the same time, mitigate disparities. Using a sample of 9,529 inmates released from Minnesota prisons who had been assessed multiple times during their confinement on a fully-automated risk assessment, this study relies on both actual and simulated data to examine the impact of program assignment decisions on changes in risk level from intake to release. The findings showed that while the risk principle was used in practice to some extent, the simulated results showed that greater adherence to the risk principle would increase reductions in risk levels and minimize the disparities observed at intake. The simulated data further revealed the most favorable outcomes would be achieved by not only applying the risk principle, but also by expanding program capacity for the higher-risk inmates in order to adequately reduce their risk.


2021 ◽  
Vol 13 (2) ◽  
pp. 826
Author(s):  
Meiling Zhou ◽  
Xiuli Feng ◽  
Kaikai Liu ◽  
Chi Zhang ◽  
Lijian Xie ◽  
...  

Influenced by climate change, extreme weather events occur frequently, and bring huge impacts to urban areas, including urban waterlogging. Conducting risk assessments of urban waterlogging is a critical step to diagnose problems, improve infrastructure and achieve sustainable development facing extreme weathers. This study takes Ningbo, a typical coastal city in the Yangtze River Delta, as an example to conduct a risk assessment of urban waterlogging with high-resolution remote sensing images and high-precision digital elevation models to further analyze the spatial distribution characteristics of waterlogging risk. Results indicate that waterlogging risk in the city proper of Ningbo is mainly low risk, accounting for 36.9%. The higher-risk and medium-risk areas have the same proportions, accounting for 18.7%. They are followed by the lower-risk and high-risk areas, accounting for 15.5% and 9.6%, respectively. In terms of space, waterlogging risk in the city proper of Ningbo is high in the south and low in the north. The high-risk area is mainly located to the west of Jiangdong district and the middle of Haishu district. The low-risk area is mainly distributed in the north of Jiangbei district. These results are consistent with the historical situation of waterlogging in Ningbo, which prove the effectiveness of the risk assessment model and provide an important reference for the government to prevent and mitigate waterlogging. The optimized risk assessment model is also of importance for waterlogging risk assessments in coastal cities. Based on this model, the waterlogging risk of coastal cities can be quickly assessed, combining with local characteristics, which will help improve the city’s capability of responding to waterlogging disasters and reduce socio-economic loss.


PLoS ONE ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. e0249937
Author(s):  
Danielle M. McLaughlin ◽  
Jack Mewhirter ◽  
Rebecca Sanders

We use survey data collected from 12,037 US respondents to examine the extent to which the American public believes that political motives drive the manner in which scientific research is conducted and assess the impact that such beliefs have on COVID-19 risk assessments. We find that this is a commonly held belief and that it is negatively associated with risk assessments. Public distrust in scientists could complicate efforts to combat COVID-19, given that risk assessments are strongly associated with one’s propensity to adopt preventative health measures.


1998 ◽  
Vol 17 (8) ◽  
pp. 454-459 ◽  
Author(s):  
Angelo Turturro ◽  
Bruce Hass ◽  
Ronald W Hart

Hormesis can be considered as a parameter which has a non-monotonic relationship with some endpoint. Since caloric intake is such a parameter, and the impact of this parameter on risk assessment has been fairly well characterized, it can provide clues as to how to integrate the information from a hormetic parameter into risk assessments for toxicants. Based on the work with caloric intake, one could: (a) define a biomarker for hormetic effect; (b) integrate specific information on when in the animals lifespan the parameter is active to influence parameters such as survival; (c) evaluate component effects of the overall hormetic response; and (d) address the consequences of a non-monotonic relationship between the hormetic parameter and endpoints critical for risk assessment. These impacts on risk assessments have been characterized for chronic tests, but are also true for short-term tests. A priority is the characterization of the dose-response curves for hormetic parameters. This quantification will be critical in utilizing them in risk assessment. With this information, one could better quantitatively address the changes one expects to result from the hormetic parameter, and limit the uncertainty and variability which occurs in toxicity testing.


Author(s):  
Otto Huisman ◽  
Ricardo Almandoz ◽  
Thomas Schuster ◽  
Adriana Andrade Caballero ◽  
Leonardo Martinez Forero

Pipeline risk analysis is a common step carried out by operators in their overall Pipeline Integrity Management Process. There is a growing realization among operators of the need to adopt more proactive risk management approaches. This has brought about increased demand for more quantitative models to support risk reduction decision-making. Consequences of failure are a key component of these models where enhanced quantitative approaches can be deployed. Impacts to the environment and upon populations are key issues which both operators and regulatory bodies seek to minimize. Pipeline risk models and High Consequence Area (HCA) analyses play an increasingly important role in this context by allowing operators to identify a range of potential scenarios and the relative impact to receptors based upon the best available data sources. This paper presents the process and results of an HCA analysis project carried out by ROSEN for a major South American state-owned pipeline operator (hereafter referred to as ‘the Client’). This analysis was implemented using automated GIS processing methods and includes HCA analyses for approximately 2354 km of pipeline. The analysis was based on industry standards for both liquid and gas pipelines (i.e. American Petroleum Institute (API) and American Society of mechanical Engineers (ASME)), but customized for the specific needs of the Client and the South American geographical context. A key use for the results of this analysis is to serve as input for the pipeline risk assessment model jointly developed by ROSEN Integrity Solutions, MACAW Engineering and the Client. The methodology for development of this model is briefly discussed, and operational uses of HCA results are illustrated. The benefits of this project include, but are not limited to, identifying areas that could be severely impacted should a pipeline failure occur, being able to assess the risk profile of credible threats in HCAs, but also being able to prioritize preventative and mitigation measures at HCAs to either reduce the likelihood of failure or the impact of failure upon various receptors.


2016 ◽  
Vol 29 (5) ◽  
pp. 423-442 ◽  
Author(s):  
James T. McCafferty

Research on risk assessments has illustrated many utilitarian purposes of these tools, including the robust prediction of recidivism and uniformity in correctional decision making. Recently, however, Former U.S. Attorney General Eric Holder vocalized his position that actuarial risk assessments could be unintentionally contributing to disproportionate minority contact in the correctional system. This study used data from approximately 2,600 juvenile delinquents assessed with the Ohio Youth Assessment System–Disposition Instrument to examine these claims across subsamples of White and Black youth. Bivariate and multivariate analyses indicated that the instrument predicted recidivism similarly across the two groups. There were slightly more prediction errors for Black youth than White youth; however, these differences may be the result of methodological factors rather than empirical realities. The article concluded with a discussion of the implications that potential racial biases have on risk assessment research and practice.


2018 ◽  
Vol 17 (5) ◽  
pp. 0-10
Author(s):  
Andrew J. Kruger ◽  
Fasika Aberra ◽  
Sylvester M. Black ◽  
Alice Hinton ◽  
James Hanje ◽  
...  

Introduction and aim. Hepatic encephalopathy (HE) is a common complication in cirrhotics and is associated with an increased healthcare burden. Our aim was to study independent predictors of 30-day readmission and develop a readmission risk model in patients with HE. Secondary aims included studying readmission rates, cost, and the impact of readmission on mortality. Material and methods. We utilized the 2013 Nationwide Readmission Database (NRD) for hospitalized patients with HE. A risk assessment model based on index hospitalization variables for predicting 30-day readmission was developed using multivariate logistic regression and validated with the 2014 NRD. Patients were stratified into Low Risk and High Risk groups. Cox regression models were fit to identify predictors of calendar-year mortality. Results. Of 24,473 cirrhosis patients hospitalized with HE, 32.4% were readmitted within 30-days. Predictors of readmission included presence of ascites (OR: 1.19; 95% CI: 1.06-1.33), receiving paracentesis (OR: 1.43; 95% CI: 1.26-1.62) and acute kidney injury (OR: 1.11; 95% CI: 1.00-1.22). Our validated model stratified patients into Low Risk and High Risk of 30-day readmissions (29% and 40%, respectively). The cost of the first readmission was higher than index admission in the 30-day readmission cohort ($14,198 vs. $10,386; p-value < 0.001). Thirty-day readmission was the strongest predictor of calendar-year mortality (HR: 4.03; 95% CI: 3.49-4.65). Conclusions. Nearly one-third of patients with HE were readmitted within 30-days, and early readmission adversely impacted healthcare utilization and calendar-year mortality. With our proposed simple risk assessment model, patients at high risk for early readmissions can be identified to potentially avert poor outcomes.


Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 3337-3337
Author(s):  
Grigoris T Gerotziafas ◽  
Miltos Chrysanthidis ◽  
Reda Isaad ◽  
Hela Baccouche ◽  
Chrysoula Papageorgiou ◽  
...  

Abstract Abstract 3337 Introduction: Risk assessment models (RAM) are helpful tools for the screening VTE risk in hospitalized patients. Most of the available RAMs have been constructed on a disease-based or surgery-based approach and include some of the most relevant risk factors for VTE. There is limited information on the impact and importance of individual and comorbidity related risk factors for VTE present during hospitalization on the global VTE risk. Incorporation of the most frequent VTE risk and bleeding risk factors related to comorbidities might improve the ability of RAM to detect real-life patients at risk VTE and to evaluate drawbacks for the application of thromboprophylaxis. Aim of the study: The primary aim of the COMPASS programme was to evaluate the prevalence of the all known VTE and bleeding risk factors reported in the literature in real-life surgical and medical hospitalized patients. Methods: A prospective multicenter cross-sectional observational study was conducted in 6 hospitals in Greece and 1 in France. All inpatients aged >40 years hospitalised for medical diseases and inpatients aged >18 years admitted due to a surgical procedure and hospitalisation for a period exceeding three days were included. Patients and their treating physicians were interviewed with standardised questionnaire including all VTE and bleeding risk factors described in literature (130 items) on the third day of hospitalisation. Patients not giving informed consent, or receiving anticoagulant treatment for any reason or hospitalised in order to undergo diagnostic investigation without any further therapeutic intervention were excluded. Results: A total of 806 patients were enrolled in the study (414 medical and 392 surgical). Most frequent causes of hospitalisation in medical patients were infection (42%), ischemic stroke (14%), cancer (13%), gastrointestinal disease (9%), pulmonary disease (4%), renal disease (3%) and rheumatologic disease (1,4%). Surgical patients were hospitalised for vascular disease (22%) cancer (19,4%) gastrointestinal disease (12,5%), infection (8%), orthopaedic surgery and trauma (14%) or minor surgery (7%). Analysis of the frequency of risk factors for VTE showed that active cancer, recent hospitalisation, venous insufficiency and total bed rest without bathroom privileges were frequent in both groups. Medical patients had significantly more frequently than surgical patients several important predisposing risk factors for VTE. Moreover, medical patient had more frequently than surgical ones bleeding risk factors. The data for the most frequent risk factors are summarised in Table 1. Conclusion: COMPASS is the first registry that provides key data on the prevalence of all known VTE and bleeding risk factors in real life medical and surgical patients hospitalised in two countries of European Union. The analysis of the data shows that in addition to risk stemin from the disease or surgical act both medical and surgical patients share common VTE risk factors. The careful analysis of the most frequent and relevant VTE risk factors will allow the derivation of a practical VTE and bleeding risk assessment model taken into account these factors. Disclosures: Chrysanthidis: Sanofi-Aventis: Employment.


Aviation ◽  
2018 ◽  
Vol 22 (4) ◽  
pp. 143-155
Author(s):  
Masoud Rezaei ◽  
Naimeh Borjalilu

Risk assessment in large organizations with extensive operational domains has been a challenging issue. Employing an efficient method along with realistic pair comparisons, applying subjective inferences of organization experts, and purging the intrinsic ambiguity of inferences, are not reflected in current airlines' safety management. Traditional two-dimensional risk assessment for risk management of safety hazards, however, is no longer sufficient to comply with this complexity. A new model for risk management and a novel formula for risk index calculation, based on a fuzzy approach, are presented in this study. In this new model, unlike in the traditional approach, the latent aftermath of safety reports, especially those which affect the continuity of the business, is also taken into account. In this model, along with the definition of a new structure for risk management, risk analysis should be restructured. To that end, a two-dimensional classic risk formula was replaced with three-dimensional (nonlinear) exponential ones, considering “the impact on the business” as a source of risk and hazard. For measuring the safety risk using the Fuzzy hierarchical evaluation method, considering experts' opinions, three criteria in four different operational fields were developed. This method employs a Fuzzy ANP to help quantify judgments, make qualitative judgments in the traditional method, and weigh the priority of elements contributing to risk. Also, it provides a tool for top-level as well as expert level management to monitor safety more precisely, monitor the safety level within their departments or organizations, set quantitative safety goals and provide feedback for improvement as well as find the most critical areas with the least cost. In this study, an airline has been selected as a case study for the risk assessment of reports based on the new model.


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