On Designing a Socially-Optimal Expedited Service When Customers Have Heterogeneous Usage Rates

2020 ◽  
Author(s):  
Ricky Roet-Green ◽  
Aditya Shetty
Keyword(s):  
Usage Rates

scholarly journals Changes in Passengers’ Travel Behavior Due to COVID-19

2021 ◽  
Vol 13 (14) ◽  
pp. 7974
Author(s):  
Dong-Gyun Ku ◽  
Jung-Sik Um ◽  
Young-Ji Byon ◽  
Joo-Young Kim ◽  
Seung-Jae Lee
Keyword(s):  
Travel Behavior ◽  
Occupancy Rate ◽  
Traffic Patterns ◽  
Similar Time ◽  
Usage Rate ◽  
Contagious Nature ◽  
Passenger Volume ◽  
Service Rates ◽  
Time Periods ◽  
Usage Rates

The COVID-19 outbreak in 2020 has changed the way people travel due to its highly contagious nature. In this study, changes in the travel behavior of passengers due to COVID-19 in the first half of 2020 were examined. To determine whether COVID-19 has affected the use of transportation by passengers, paired t-tests were conducted between the passenger volume of private vehicles in Seoul prior to and after the pandemic. Additionally, the passenger occupancy rate of different modes of transportation during the similar time periods were compared and analyzed to identify the changes in monthly usage rate for each mode. In the case of private vehicles and public bicycles, the usage rates have recovered or increased when compared to those of before the pandemic. Conversely, bus and rail passenger service rates have decreased from the previous year before the pandemic. Furthermore, it is found that existing bus and rail users have switched to the private auto mode due to COVID-19. Based on the results, traffic patterns of travelers after the outbreak and implications responding to the pandemic are discussed.

Adjusted and unadjusted energy usage rates both determine body fat and plasma leptin in male Fischer 344 rats

Metabolism ◽  
1999 ◽  
Vol 48 (10) ◽  
pp. 1272-1277 ◽  
Author(s):  
James A. Greenberg ◽  
Shah Rahman ◽  
Sandra Saint-Preux ◽  
David R. Owen ◽  
Carol N. Boozer
Keyword(s):  
Body Fat ◽  
Fischer 344 Rats ◽  
Energy Usage ◽  
Fischer 344 ◽  
Plasma Leptin ◽  
Usage Rates

Field Reliability Estimation of Agricultural Tractors Based on Warranty Data

2021 ◽  
Vol 64 (2) ◽  
pp. 705-714
Author(s):  
Zhilin Zhao ◽  
Fang Cheng
Keyword(s):  
Regression Model ◽  
List Type ◽  
Reliability Parameters ◽  
Light Gradient ◽  
Manufacturing Company ◽  
Agricultural Tractors ◽  
Warranty Claims ◽  
Field Reliability ◽  
Usage Context ◽  
Usage Rates

HighlightsA LightGBM regression model for predicting tractor usage rates was established based on warranty data and considering agricultural tractors’ usage context (region and season) and was then interpreted using SHAP.The field reliability of tractors was estimated based on the usage of failed and unfailed tractors, after unfailed tractors’ usage was imputed using the LightGBM regression model.The proposed methodology was validated by predicting warranty claims using estimated reliability parameters.The proposed methodology was demonstrated using warranty data from a tractor manufacturing company in China.Abstract. Warranty data provide a valuable source of information for assessing the reliability of products in operation (called the field reliability). However, warranty data consist of failure information only. The unavailability of usage data for unfailed products makes it difficult to estimate the reliability of durable products such as agricultural tractors, for which usage is a greater concern than age for reliability analysis. Several studies have proposed methods to address this problem, but they did not include information on the usage context. This study proposes a methodology to estimate the field reliability of agricultural tractors from warranty data considering the tractors’ usage context. First, by taking features representing tractors’ usage context as the input, a usage rate regression model was established using a light gradient boosting machine (LightGBM). The usage of unfailed tractors was then generated. Finally, parametric estimates of the tractors’ reliability were determined based on the usage of failed and unfailed tractors. By interpreting the LightGBM model using SHapley Additive exPlanations (SHAP), it was found that tractors that were used more days in October and April had higher predicted usage rates. To validate the effectiveness of the proposed methodology, the estimated reliability parameters were used to predict the warranty claims of six types of tractors. The results showed that the proposed methodology performed the best in four cases and close to the best in two other cases when compared with two other baseline methods. The proposed methodology was demonstrated using warranty data from an agricultural tractor manufacturing company in China and can be applied to improve understanding of tractor reliability. Keywords: Field reliability, LightGBM, SHAP, Usage context, Warranty data.

scholarly journals Research on Pricing of Flexible Two-Dimensional Extended Warranty Considering Preventive Maintenance

2019 ◽  
Vol 37 (2) ◽  
pp. 393-400
Author(s):  
Xiaolei Zhang ◽  
Chun Su
Keyword(s):  
Preventive Maintenance ◽  
Two Dimensional ◽  
Maintenance Strategy ◽  
Pricing Model ◽  
Reduction Model ◽  
Warranty Period ◽  
Extended Warranty ◽  
Warranty Cost ◽  
Usage Rates

Facing the uncertainty in transaction of two-dimensional extended warranty, a flexible pricing model is presented considering imperfect preventive maintenance combined with the degradation characteristics of item. The measure of two-dimensional preventive maintenance is carried out based on specified age interval or usage interval, the effect of imperfect preventive maintenance is described by age reduction model. The extended warranty cost is modeled from the perspective of manufacturer and customer, the method of gridding search is employed to optimize the maintenance strategy under different cases. Moreover, customized extended warranty price and warranty services are proposed on the basis of consumer usage rates. The results demonstrate that it is helpful to maximize the benefit of vendor by providing customized warranty strategy, the implementation of preventive maintenance during the whole warranty period can effectively reduce warranty cost for both sides.

Analysis of situation of acute coronary syndrome based on the date of the Improving Care for Cardiovascular Disease in China–Acute Coronary Syndrome (CCC-ACS) project: single-centre observational study

2020 ◽  
pp. postgradmedj-2019-137008 ◽  
Author(s):  
Jiaying Li ◽  
Hui Peng ◽  
Xiexiong Zhao ◽  
Nana You ◽  
Yuyan Wu ◽  
...  
Keyword(s):  
Cardiovascular Disease ◽  
Acute Coronary Syndrome ◽  
Clinical Practice ◽  
Reperfusion Therapy ◽  
Hunan Province ◽  
Drug Usage ◽  
Coronary Syndrome ◽  
Central South ◽  
Usage Rates

BackgroundWe are currently faced with an increasing burden of cardiovascular disease in China and the inadequacy of the application of guidelines in clinical practice. In the past decade, China has been strengthening the healthcare system, but it still lacked a national performance measurement system and an appropriate quality improvement strategy. Therefore, in order to improve the implementation of guideline recommendations in clinical practice, China has learnt from the successful experience of Get With The Guidelines project in 2014. Under the guidance of the Medical and Health Hospital of the National Health and Family Planning Commission, the Chinese Society of Cardiology and the American Heart Association jointly launched the Improving Care for Cardiovascular Disease in China (CCC) project. The project team provided an analysis report on the completion of key medical quality evaluation indicators of each hospital every month, supplied guidance through education, training, experience exchange and on-site investigation for problems, and certified hospitals with outstanding performance and obvious progress. The circle pattern, including evaluation, training, improvement and re-evaluation, will boost the guidelines compliance on clinical practice in China and improve the quality of medical services.MethodsThis study was conducted in a centre of the Third Xiangya Hospital of Central South University. It included patients with ACS from December 2009 to December 2011 (n=225), patients with ACS in the Improving Care for Cardiovascular Disease in China–Acute Coronary Syndrome project coming from the Third Xiangya Hospital of Central South University (n=665), 12 hospitals in Hunan Province (n=4333) and 150 hospitals in China (n=63 641) from November 2014 to April 2017. It assessed the situation of drug therapy, hospitalisation day, mortality during hospitalisation, median of door-to-needle (D-to-N) time and median of door-to-balloon (D-to-B) time of patients with ST-segment elevation myocardial infarction (STEMI), the proportion of D-to-N within 30 min and D-to-B within 90 min, and the proportion of reperfusion therapy. Patients with ACS from the centre from November 2014 to April 2017 were divided into five groups (every 6 months as a group according to time). The study observed change trends in all the above-mentioned indexes.ResultsCompared with before participating in the CCC project, there were increases after participating in the CCC project in the drug usage rates of aspirin, P2Y12 inhibitor (clopidogrel or ticagrelor), β-blocker, statin and angiotensin converting enzyme inhibitor (ACEI)/angiotensin-receptor blocker (ARB). Hospitalisation day and mortality during hospitalisation were shortened. D-to-N and D-to-B times of patients with STEMI were shorter. Compared with Hunan Province and China, the drug usage rates were higher; hospitalisation day and D-to-N time were shorter; D-to-B time was longer; and the proportion of reperfusion therapy was higher. The trend of drug usage rates was on the rise. There was no significant change in the hospitalisation day and D-to-N and D-to-B times. The mortality during hospitalisation showed a downward trend. The proportion of D-to-N within 90 min and reperfusion therapy showed upward trends.ConclusionQuality of care for patients with ACS improved over time in the CCC project, including taking medicine following the guidelines, increased use of reperfusion therapy and faster time to treatment. Although overall mortality has improved, we also should attach importance to high-risk patients. The influence of the CCC project, which is based on guidelines on prognosis of ACS in the centre, presents an important clinical implication that it is necessary to enhance adherence to the guidelines in the treatment of ACS.

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