A Nonparametric Hawkes Model for Forecasting California Seismicity

2021 ◽  
Author(s):  
Joshua Seth Gordon ◽  
Eric Warren Fox ◽  
Frederic Paik Schoenberg
Keyword(s):  
Fault Estimation ◽  
Earthquake Catalog ◽  
Simulation Studies ◽  
Earthquake Triggering ◽  
Forecast Performance ◽  
Nonparametric Models ◽  
Model Independent ◽  
Improved Performance ◽  
Nonparametric Estimates

ABSTRACT A variety of nonparametric models have been proposed for estimating earthquake triggering. We investigate the ability of the model-independent stochastic declustering method developed by Marsan and Lengliné (2008) to estimate variable spatial triggering that can vary with direction, magnitude, and region. We develop an approach for local fault estimation and demonstrate forecasting methods that use the nonparametric estimates. Simulation studies are conducted to verify the effectiveness of the method, and the nonparametric estimates are applied to a California earthquake catalog. Model forecast performance is evaluated retrospectively by comparing our models with the long-term forecast of Helmstetter et al. (2007), using both deviance and Voronoi residuals. We show improved performance compared with Helmstetter et al. (2007) in various regions while using a full nonparametric estimation and forecasting approach.

Bleaching optimization at WestRock mill in Covington, Virginia

TAPPI Journal ◽  
2016 ◽  
Vol 15 (9) ◽  
pp. 581-586 ◽  
Author(s):  
RICARDO B. SANTOS ◽  
PETER W. HART ◽  
DOUGLAS C. PRYKE ◽  
JOHN VANDERHEIDE
Keyword(s):  
Hydrogen Peroxide ◽  
Sodium Hydroxide ◽  
Chlorine Dioxide ◽  
Capital Expenditures ◽  
Equipment Repair ◽  
Optimization Program ◽  
Hardwood Pulp ◽  
Improved Performance

The WestRock mill in Covington, VA, USA, initiated a long term diagnostic and optimization program for all three of its bleaching lines. Benchmarking studies were used to help identify optimization opportunities. Capital expenditures for mixing improvement, filtrate changes, equipment repair, other equipment changes, and species changes were outside the scope of this work. This focus of this paper is the B line, producing southern hardwood pulp in a D(EP)DD sequence at 88% GE brightness. The benchmarking study and optimization work identified the following opportunities for improved performance: nonoptimal addition of caustic and hydrogen peroxide to the (EP) stage, carryover of D0 filtrate to the (EP) stage, and carryover of (EP) filtrate to the D1 stage. As a result of actions the mill undertook to address these opportunities, D0 kappa factor decreased about 5%, sodium hydroxide consumption in the (EP) stage decreased about 35%, chlorine dioxide consumption in the D1 stage decreased about 25%, and overall bleaching cost decreased about 15%.

scholarly journals Engineering Sr-doping for enabling long-term stable FAPb1−xSrxI3 quantum dots with 100% photoluminescence quantum yield

2021 ◽  
Vol 9 (5) ◽  
pp. 1555-1566
Author(s):  
Andrés F. Gualdrón-Reyes ◽  
David F. Macias-Pinilla ◽  
Sofia Masi ◽  
Carlos Echeverría-Arrondo ◽  
Said Agouram ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Quantum Yield ◽  
Toxic Metals ◽  
Environmentally Friendly ◽  
Photoluminescence Quantum Yield ◽  
Improved Performance ◽  
Pb Substitution

The Pb substitution in quantum dots (PQDs) with lesser toxic metals has been widely searched to be environmentally friendly, and be of comparable or improved performance compared to the lead-perovskite.

Learning Processes and Violent Video Games

2011 ◽  
pp. 1807-1822
Author(s):  
Edward L. Swing ◽  
Douglas A. Gentile ◽  
Craig A. Anderson
Keyword(s):  
Video Games ◽  
Learning Outcomes ◽  
Learning Processes ◽  
Long Term Effects ◽  
Violent Video Games ◽  
Improved Performance ◽  
Learning Principles ◽  
General Learning Model ◽  
Basic Learning

Though video games can produce desirable learning outcomes, such as improved performance in school subjects, they also can produce undesirable outcomes, such as increased aggression. Some of the basic learning principles that make video games (particularly violent video games) effective at teaching are discussed in this chapter. A general learning model is presented to explain how video games can produce a variety of effects in their users. This model explains both the immediate, short term effects and cumulative, long term effects of video games. Implications of these principles are discussed in relation to education. The issue of addressing violent video games’ effects on aggression is also examined.

Organizational Performance through Dairy Supply Chain Management Practices

2016 ◽  
pp. 84-96
Author(s):  
Rajeev Kumar
Keyword(s):  
Supply Chain ◽  
Supply Chain Management ◽  
Organizational Performance ◽  
Management System ◽  
Market Performance ◽  
Customer Relationship ◽  
Chain Management ◽  
Improved Performance ◽  
The Relationship

Organizational implementing supply chain management (SCM) has obtained improved performance. Cost savings, increased revenues and the reduction of defects in products are some of the main advantages of introducing dairy supply chain management. These are also mentioned as long-term goals of the supply chain. Business profitability is closely associated with market and business shares. Based on the long-term goals of the SCM, the organizational performance measures are identified as financial and market performance and customer satisfaction. In the context of SCM, the financial and market performance factor is operational zed in terms of market share, return of total assets, annuals sales growth (Tan et al, 1999).The research paper attempts to find out the relationship between the dairy supply chain management (DSCM) practices and organizational performance. Various practices of DSCM through extensive literature review is taken into account i.e. Information and Communication Technology Practices, Supplier Relationship Practices, Supply Chain Manufacturing Practices, Inventory management system, Warehousing Management System, Transportation Management System, Customer Relationship Management for establishing the relationship with organizational performance. The aim of this study is to recommend these findings to companies which are still at the infancy stage when it comes to dairy supply chain management and integration with customers and suppliers.

Optimization of Structural Design for High-Performance Concrete Bridges

1998 ◽  
Vol 1624 (1) ◽  
pp. 132-139
Author(s):  
Mary Lou Ralls ◽  
Ramon L. Carrasquillo ◽  
Ned H. Burns
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
High Strength ◽  
Cost Effective ◽  
Concrete Bridges ◽  
Practical Guidelines ◽  
Improved Performance ◽  
Maintenance Requirements ◽  
Design And Construction

High-performance concrete (HPC) bridges can be cost-effective both initially and in the long term, provided the design and construction optimize the improved performance characteristics of HPC. Using the high-strength characteristic of HPC can reduce the required number and size of beams. Using the improved durability characteristics of HPC can reduce maintenance requirements and extend the service life. Practical guidelines help design and construction engineers implement HPC in bridges.

scholarly journals Creatine Use in Sports

2017 ◽  
Vol 10 (1) ◽  
pp. 31-34 ◽  
Author(s):  
Jessica Butts ◽  
Bret Jacobs ◽  
Matthew Silvis
Keyword(s):  
Dietary Supplement ◽  
National Collegiate Athletic Association ◽  
Creatine Supplementation ◽  
Sports Performance ◽  
Short Term ◽  
Level Of Evidence ◽  
Improved Performance ◽  
Google Search ◽  
Long Term Studies

Context: The use of creatine as a dietary supplement has become increasingly popular over the past several decades. Despite the popularity of creatine, questions remain with regard to dosing, effects on sports performance, and safety. Evidence Acquisition: PubMed was searched for articles published between 1980 and January 2017 using the terms creatine, creatine supplementation, sports performance, and dietary supplements. An additional Google search was performed to capture National Collegiate Athletic Association–specific creatine usage data and US dietary supplement and creatine sales. Study Design: Clinical review. Level of Evidence: Level 4. Results: Short-term use of creatine is considered safe and without significant adverse effects, although caution should be advised as the number of long-term studies is limited. Suggested dosing is variable, with many different regimens showing benefits. The safety of creatine supplementation has not been studied in children and adolescents. Currently, the scientific literature best supports creatine supplementation for increased performance in short-duration, maximal-intensity resistance training. Conclusion: While creatine appears to be safe and effective for particular settings, whether creatine supplementation leads to improved performance on the field of play remains unknown.

scholarly journals Six out of ten patients with sinus tarsi syndrome returned to pre-injury type of sport after subtalar arthroscopy

2020 ◽  
Author(s):  
Kenny Lauf ◽  
Jari Dahmen ◽  
J. Nienke Altink ◽  
Sjoerd A. S. Stufkens ◽  
Gino M. M. J. Kerkhoffs
Keyword(s):  
Clinical Outcomes ◽  
Median Time ◽  
Outcome Measures ◽  
Return To Sport ◽  
Injury Type ◽  
Sinus Tarsi ◽  
Sinus Tarsi Syndrome ◽  
Improved Performance

Abstract Purpose The purpose of this study was to determine multiple return to sport rates, long-term clinical outcomes and safety for subtalar arthroscopy for sinus tarsi syndrome. Methods Subtalar arthroscopies performed for sinus tarsi syndrome between 2013 and 2018 were analyzed. Twenty-two patients were assessed (median age: 28 (IQR 20–40), median follow-up 60 months (IQR 42–76). All patients were active in sports prior to the injury. The primary outcome was the return to pre-injury type of sport rate. Secondary outcomes were time and rate of return to any type of sports, return to performance and to improved performance. Clinical outcomes consisted of Numerous Rating Scale of pain, Foot and Ankle Outcome Score, 36-item Short Form Survey and complications and re-operations. Results Fifty-five percent of the patients returned to their preoperative type of sport at a median time of 23 weeks post-operatively (IQR 9.0–49), 95% of the patients returned to any type and level sport at a median time of 12 weeks post-operatively (IQR 4.0–39), 18% returned to their preoperative performance level at a median time of 25 weeks post-operatively (IQR 8.0–46) and 5% returned to improved performance postoperatively at 28 weeks postoperatively (one patient). Median NRS in rest was 1.0 (IQR 0.0–4.0), 2.0 during walking (IQR 0.0–5.3) during walking, 3.0 during running (IQR 1.0–8.0) and 2.0 during stair-climbing (IQR 0.0–4.5). The summarized FAOS score was 62 (IQR 50–90). The median SF-36 PCSS and the MCSS were 46 (IQR 41–54) and 55 (IQR 49–58), respectively. No complications and one re-do subtalar arthroscopy were reported. Conclusion Six out of ten patients with sinus tarsi syndrome returned to their pre-injury type of sport after being treated with a subtalar arthroscopy. Subtalar arthroscopy yields effective outcomes at long-term follow-up concerning patient-reported outcome measures in athletic population, with favorable return to sport level, return to sport time, clinical outcomes and safety outcome measures. Level of evidence IV.

Long‐Term Earthquake Hazard in North China Estimated from a Modern Catalog

2019 ◽  
Vol 109 (6) ◽  
pp. 2340-2355 ◽  
Author(s):  
Ziyao Xiong ◽  
Jiancang Zhuang ◽  
Shiyong Zhou
Keyword(s):  
Bayesian Method ◽  
North China ◽  
Voronoi Tessellation ◽  
Earthquake Hazard ◽  
B Value ◽  
Estimation Methods ◽  
Earthquake Catalog ◽  
Function Estimation ◽  
Simulation Experiments

Abstract In this study, to obtain optimal estimates of the earthquake hazard in North China based on the modern earthquake catalog, we used two variable kernel function estimation methods, proposed by Stock and Smith, and Zhuang, the Bayesian Delaunay tessellation smoothing method by Ogata (ODTB), and a newly proposed incomplete centroidal Voronoi tessellation (ICVT) method, to calculate the total and background seismic spatial occurrence rates for the study area. The sophisticated ODTB method is more stable than the others, but is relatively expensive, in terms of computation demands, whereas Zhuang et al.’s kernel estimate and the new ICVT method are able to provide reasonable estimates and easier to implement. We also calculated the spatial variations of the b‐value, using the Bayesian method with smoothness prior proposed by Ogata. Using comparative analyses and simulation experiments, we show that all of the methods give similar spatial patterns of seismic occurrences.

scholarly journals The effects of hybrid pay incentives on work-team performance: A longitudinal study

2015 ◽  
Vol 18 (4) ◽  
pp. 463-474
Author(s):  
Mbusi Dlamini ◽  
Margie Sutherland ◽  
Merle Werbeloff
Keyword(s):  
Work Performance ◽  
Field Studies ◽  
Individual Performance ◽  
Work Team ◽  
Team Members ◽  
Incentive Structures ◽  
Improved Performance ◽  
The Individual ◽  
Pay Incentives

Despite the widespread use of pay incentives to drive performance, few studies empirically demonstrate their long-term benefits within work-team settings in field studies; even fewer studies incorporate hybrid pay incentives in their design. This longitudinal field study explored the effects on individual work performance of allocating tellers to teams with supervisors who received hybrid pay incentives, where 60 per cent of their incentive was based on the individual performance of each of their team members and 40 per cent on their own performance. It was conducted on bulk-cash tellers working in 19 centres, using a time-series design. The results, derived from quantitative data collected from 82 individual tellers over 24 months, showed that hybrid pay incentives for supervisors of teams of tellers, some of whom were individually incentivised, were associated with significant increases in the volume, speed and accuracy of deposit processing by all the tellers. The findings empirically demonstrate the long term sustainability of improved performance associated with the introduction of hybrid pay incentive structures within work teams.

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