BACKGROUND Lower gastrointestinal bleeds(LGIB)is a very common inpatient condition in the United States.Gastrointestinal bleeds have a variety of presentations,from minor bleeding to severe hemorrhage and shock.Althou...BACKGROUND Lower gastrointestinal bleeds(LGIB)is a very common inpatient condition in the United States.Gastrointestinal bleeds have a variety of presentations,from minor bleeding to severe hemorrhage and shock.Although previous studies investigated the efficacy of colonoscopy in hospitalized patients with LGIB,there is limited research that discusses disparities in colonoscopy utilization in patients with LGIB in urban and rural settings.AIM To investigate the difference in utilization of colonoscopy in lower gastrointestinal bleeding between patients hospitalized in urban and rural hospitals.METHODS This is a retrospective cohort study of 157748 patients using National Inpatient Sample data and the Healthcare Cost and Utilization Project provided by the Agency for Healthcare Research and Quality.It includes patients 18 years and older hospitalized with LGIB admitted between 2010 and 2016.This study does not differentiate between acute and chronic LGIB and both are included in this study.The primary outcome measure of this study was the utilization of colonoscopy among patients in rural and urban hospitals admitted for lower gastrointestinal bleeds;the secondary outcome measures were in-hospital mortality,length of stay,and costs involved in those receiving colonoscopy for LGIB.Statistical analyses were all performed using STATA software.Logistic regression was used to analyze the utilization of colonoscopy and mortality,and a generalized linear model was used to analyze the length of stay and cost.RESULTS Our study found that 37.9%of LGIB patients at rural hospitals compared to approximately 45.1%at urban hospitals received colonoscopy,(OR=0.730,95%CI:0.705-0.7,P>0.0001).After controlling for covariates,colonoscopies were found to have a protective association with lower inhospital mortality[OR=0.498,95%CI:0.446-0.557,P<0.0001],but a longer length of stay by 0.72 d(95%CI:0.677-0.759 d,P<0.0001)and approximately$2199 in increased costs.CONCLUSION Although there was a lower percentage of LGIB patients that received colonoscopies in rural hospitals compared to urban hospitals,patients in both urban and rural hospitals with LGIB undergoing colonoscopy had decreased in-hospital mortality.In both settings,benefit came at a cost of extended stay,and higher total costs.展开更多
In this paper, the operation of the Double Fed Induction Generator (DFIG) in the range from synchronous speed down to sub-synchronous speeds is analyzed using the power-flow approach. The objective of this analysis is...In this paper, the operation of the Double Fed Induction Generator (DFIG) in the range from synchronous speed down to sub-synchronous speeds is analyzed using the power-flow approach. The objective of this analysis is to determine a ceiling for the rating of the converter interfacing the rotor of the wind driven double fed induction generator (DFIG) to the grid. Sizing the converter is an important issue in determining the economic viability of using the DFIM as a generator at synchronous and sub-synchronous speeds in wind energy conversion systems. The size of the converter is proved to be less than 10% of the rated power of the DFIG, which is 40% to 67% lower than that estimated in previous publications.展开更多
A novel test access mechanism （TAM） architecture with multi test-channel （TC） based on IEEE Standard 1500 is proposed instead of the traditional sub-TAM structure. The cost model of an area-time associated test an...A novel test access mechanism （TAM） architecture with multi test-channel （TC） based on IEEE Standard 1500 is proposed instead of the traditional sub-TAM structure. The cost model of an area-time associated test and the corresponding lower bound of system-on-chip （SoC） test time are established based on this TAM architecture. The model provides a more reliable method to control the SoC scheduling and reduces the complexity in related algorithm research. The result based on the area time associated test cost model has been validated using the ITC02 test benchmark.展开更多
Due to high competition of the agriculture machines sector, the auto parts suppliers are investing in research to promote the development and reduce the costs of the products, passing these results to their clients wh...Due to high competition of the agriculture machines sector, the auto parts suppliers are investing in research to promote the development and reduce the costs of the products, passing these results to their clients who are the automakers. It was identified the need to redesign the regulation sieve system harvester, which is a compound assembly in the harvester＇s grain cleaning system, with the objective to reduce the costs and improve the ergonomic aspect, keeping the same efficiency from the original project. The improvement was developed by studying the original design and identifying possible project fails, such as components and manufacturing process which could be eliminated. For this, it was needed to do a research about rules and project considerations that must be applied in the products development and ergonomic too, specifically about geometric forms and anthropometric measures. From the redesign of this system, it is verified that it is possible by a study to identify possible improvements, and to develop a new system by a simple project, improving the ergonomic, reducing the cost and keeping the same efficacy from the original project.展开更多
整车制造业中,物流是非增值环节,物流成本的削减可以为企业赢取更高的边际利润。为了降低厂内生产物流成本,准时化生产(JIT,Just in Time),排序拉动生产(JIS,Just in Sequence),物流服务外包等模式应运而生。文章以北京奔驰后驱车工厂为...整车制造业中,物流是非增值环节,物流成本的削减可以为企业赢取更高的边际利润。为了降低厂内生产物流成本,准时化生产(JIT,Just in Time),排序拉动生产(JIS,Just in Sequence),物流服务外包等模式应运而生。文章以北京奔驰后驱车工厂为例,对厂内的生产物流作业成本进行研究。以零件进入车间为起点,以最小化厂内物流作业成本为目标,综合考虑实际生产约束,搭建收货、入库、出库和配线四大厂内物流作业成本优化模型并成功应用,既实现了本企业生产运营成本的节约,也为其他汽车企业的厂内物流成本优化提供借鉴思路。展开更多
The paper presents a comprehensive model of a banking system that integrates network effects,bankruptcy costs,fire sales,and cross-holdings.For the integrated financial market we prove the existence of a price-payment...The paper presents a comprehensive model of a banking system that integrates network effects,bankruptcy costs,fire sales,and cross-holdings.For the integrated financial market we prove the existence of a price-payment equilibrium and design an algorithm for the computation of the greatest and the least equilibrium.The number of defaults corresponding to the greatest price-payment equilibrium is analyzed in several comparative case studies.These illustrate the individual and joint impact of interbank liabilities,bankruptcy costs,fire sales and cross-holdings on systemic risk.We study policy implications and regulatory instruments,including central bank guarantees and quantitative easing,the significance of last wills of financial institutions,and capital requirements.展开更多
Different forest fires causing different degrees of effects occur in fire-sensitive forests due to various reasons such as climate change.Useful as well as harmful aspects of forest fires are a multi-disciplinary rese...Different forest fires causing different degrees of effects occur in fire-sensitive forests due to various reasons such as climate change.Useful as well as harmful aspects of forest fires are a multi-disciplinary research topic.Geographical information systems(GIS)and remote sensing(RS)methods offer a number of benefits for researchers and operators in the field of forest fire research.The present study analyses timber pricing based on forest contractor demands of post-salvage logging processes.The effect of timber obtained from compartment units on producers’pricing policy was modelled.Sapadere forest fire area(2500 ha)located in Antalya in Turkey was selected as the main study area.Topography parameters(aspect,slope and slope position),stand types(diameter class and crown closure),and burn severity were analyzed together using GIS and R software packages.A multi-linear regression model(R^(2)=0.752)demonstrated that factors that had the most impact on pricing were slope position,aspect,stand age,crown closure and burn severity.This model can be used to estimate salvage logging prices in Calabrian pine(Pinus brutia Ten.)stands with similar parameters.Forest administrators and contractors may readily address the unit price of timber by estimating approximate costs in a given forest area for which they are going to bid.This will help reduce operational planning times of harvesting procedures in burned stands.展开更多
The Economic Production Quantity (EPQ) model is commonly used by practitioners in the fields of production and inventory management to assist them in making decision on production lot size. The common assumptions in t...The Economic Production Quantity (EPQ) model is commonly used by practitioners in the fields of production and inventory management to assist them in making decision on production lot size. The common assumptions in this model are that all units produced are perfect and shortages are not allowed. But, in real situation the defective items will be produced in each cycle of production and shortages and scrap are possible. These assumptions will underestimate the actual required quantity. Hence, the defective items can not be ignored in the production process. Rework process is necessary to convert those defective into finished goods. This study proposes EPQ model that incorporates both imperfect production quality and falsely not screening out a proportion of defects, thereby passing them on to customers, resulting in defect sales returns. To active this objective a suitable mathematical model is developed and the optimal production lot size which minimizes the total cost is derived. An illustrative example is provided and numerically verified. The validation of result in this model was coded in Microsoft Visual Basic 6.0.展开更多
The minimum cost of capacity expansion for time-limited transportation problem on-demand (MCCETLTPD) is to find such a practicable capacity expansion transportation scheme satisfying the time-limited T along with all ...The minimum cost of capacity expansion for time-limited transportation problem on-demand (MCCETLTPD) is to find such a practicable capacity expansion transportation scheme satisfying the time-limited T along with all origins’ supply and all destinations’ demands as well as the expanding cost is minimum. Actually, MCCETLTPD is a balance transportation problem and a variant problem of minimum cost maximum flow problem. In this paper, by creating a mathematical model and constructing a network with lower and upper arc capacities, MCCETLTPD is transformed into searching feasible flow in the constructed network, and consequently, an algorithm MCCETLTPD-A is developed as MCCETLTPD’s solution method basing minimum cost maximum flow algorithm. Computational study validates that the MCCETLTPD-A algorithm is an efficient approach to solving the MCCETLTPD.展开更多
文摘BACKGROUND Lower gastrointestinal bleeds(LGIB)is a very common inpatient condition in the United States.Gastrointestinal bleeds have a variety of presentations,from minor bleeding to severe hemorrhage and shock.Although previous studies investigated the efficacy of colonoscopy in hospitalized patients with LGIB,there is limited research that discusses disparities in colonoscopy utilization in patients with LGIB in urban and rural settings.AIM To investigate the difference in utilization of colonoscopy in lower gastrointestinal bleeding between patients hospitalized in urban and rural hospitals.METHODS This is a retrospective cohort study of 157748 patients using National Inpatient Sample data and the Healthcare Cost and Utilization Project provided by the Agency for Healthcare Research and Quality.It includes patients 18 years and older hospitalized with LGIB admitted between 2010 and 2016.This study does not differentiate between acute and chronic LGIB and both are included in this study.The primary outcome measure of this study was the utilization of colonoscopy among patients in rural and urban hospitals admitted for lower gastrointestinal bleeds;the secondary outcome measures were in-hospital mortality,length of stay,and costs involved in those receiving colonoscopy for LGIB.Statistical analyses were all performed using STATA software.Logistic regression was used to analyze the utilization of colonoscopy and mortality,and a generalized linear model was used to analyze the length of stay and cost.RESULTS Our study found that 37.9%of LGIB patients at rural hospitals compared to approximately 45.1%at urban hospitals received colonoscopy,(OR=0.730,95%CI:0.705-0.7,P>0.0001).After controlling for covariates,colonoscopies were found to have a protective association with lower inhospital mortality[OR=0.498,95%CI:0.446-0.557,P<0.0001],but a longer length of stay by 0.72 d(95%CI:0.677-0.759 d,P<0.0001)and approximately$2199 in increased costs.CONCLUSION Although there was a lower percentage of LGIB patients that received colonoscopies in rural hospitals compared to urban hospitals,patients in both urban and rural hospitals with LGIB undergoing colonoscopy had decreased in-hospital mortality.In both settings,benefit came at a cost of extended stay,and higher total costs.
文摘In this paper, the operation of the Double Fed Induction Generator (DFIG) in the range from synchronous speed down to sub-synchronous speeds is analyzed using the power-flow approach. The objective of this analysis is to determine a ceiling for the rating of the converter interfacing the rotor of the wind driven double fed induction generator (DFIG) to the grid. Sizing the converter is an important issue in determining the economic viability of using the DFIM as a generator at synchronous and sub-synchronous speeds in wind energy conversion systems. The size of the converter is proved to be less than 10% of the rated power of the DFIG, which is 40% to 67% lower than that estimated in previous publications.
基金Project supported by the SDC Project of Science and Technology Commission of Shanghai Municipality (Grant No.08706201000)the AM Foundation Project of Science and Technology Commission of Shanghai Municipality (Grant No.08700741000)+1 种基金the Leading Academic Discipline Project of Shanghai Education Commission (Grant No.J50104)the Innovation Foundation Project of Shanghai University
文摘A novel test access mechanism （TAM） architecture with multi test-channel （TC） based on IEEE Standard 1500 is proposed instead of the traditional sub-TAM structure. The cost model of an area-time associated test and the corresponding lower bound of system-on-chip （SoC） test time are established based on this TAM architecture. The model provides a more reliable method to control the SoC scheduling and reduces the complexity in related algorithm research. The result based on the area time associated test cost model has been validated using the ITC02 test benchmark.
文摘Due to high competition of the agriculture machines sector, the auto parts suppliers are investing in research to promote the development and reduce the costs of the products, passing these results to their clients who are the automakers. It was identified the need to redesign the regulation sieve system harvester, which is a compound assembly in the harvester＇s grain cleaning system, with the objective to reduce the costs and improve the ergonomic aspect, keeping the same efficiency from the original project. The improvement was developed by studying the original design and identifying possible project fails, such as components and manufacturing process which could be eliminated. For this, it was needed to do a research about rules and project considerations that must be applied in the products development and ergonomic too, specifically about geometric forms and anthropometric measures. From the redesign of this system, it is verified that it is possible by a study to identify possible improvements, and to develop a new system by a simple project, improving the ergonomic, reducing the cost and keeping the same efficacy from the original project.
文摘整车制造业中,物流是非增值环节,物流成本的削减可以为企业赢取更高的边际利润。为了降低厂内生产物流成本,准时化生产(JIT,Just in Time),排序拉动生产(JIS,Just in Sequence),物流服务外包等模式应运而生。文章以北京奔驰后驱车工厂为例,对厂内的生产物流作业成本进行研究。以零件进入车间为起点,以最小化厂内物流作业成本为目标,综合考虑实际生产约束,搭建收货、入库、出库和配线四大厂内物流作业成本优化模型并成功应用,既实现了本企业生产运营成本的节约,也为其他汽车企业的厂内物流成本优化提供借鉴思路。
文摘The paper presents a comprehensive model of a banking system that integrates network effects,bankruptcy costs,fire sales,and cross-holdings.For the integrated financial market we prove the existence of a price-payment equilibrium and design an algorithm for the computation of the greatest and the least equilibrium.The number of defaults corresponding to the greatest price-payment equilibrium is analyzed in several comparative case studies.These illustrate the individual and joint impact of interbank liabilities,bankruptcy costs,fire sales and cross-holdings on systemic risk.We study policy implications and regulatory instruments,including central bank guarantees and quantitative easing,the significance of last wills of financial institutions,and capital requirements.
文摘Different forest fires causing different degrees of effects occur in fire-sensitive forests due to various reasons such as climate change.Useful as well as harmful aspects of forest fires are a multi-disciplinary research topic.Geographical information systems(GIS)and remote sensing(RS)methods offer a number of benefits for researchers and operators in the field of forest fire research.The present study analyses timber pricing based on forest contractor demands of post-salvage logging processes.The effect of timber obtained from compartment units on producers’pricing policy was modelled.Sapadere forest fire area(2500 ha)located in Antalya in Turkey was selected as the main study area.Topography parameters(aspect,slope and slope position),stand types(diameter class and crown closure),and burn severity were analyzed together using GIS and R software packages.A multi-linear regression model(R^(2)=0.752)demonstrated that factors that had the most impact on pricing were slope position,aspect,stand age,crown closure and burn severity.This model can be used to estimate salvage logging prices in Calabrian pine(Pinus brutia Ten.)stands with similar parameters.Forest administrators and contractors may readily address the unit price of timber by estimating approximate costs in a given forest area for which they are going to bid.This will help reduce operational planning times of harvesting procedures in burned stands.
文摘The Economic Production Quantity (EPQ) model is commonly used by practitioners in the fields of production and inventory management to assist them in making decision on production lot size. The common assumptions in this model are that all units produced are perfect and shortages are not allowed. But, in real situation the defective items will be produced in each cycle of production and shortages and scrap are possible. These assumptions will underestimate the actual required quantity. Hence, the defective items can not be ignored in the production process. Rework process is necessary to convert those defective into finished goods. This study proposes EPQ model that incorporates both imperfect production quality and falsely not screening out a proportion of defects, thereby passing them on to customers, resulting in defect sales returns. To active this objective a suitable mathematical model is developed and the optimal production lot size which minimizes the total cost is derived. An illustrative example is provided and numerically verified. The validation of result in this model was coded in Microsoft Visual Basic 6.0.
文摘The minimum cost of capacity expansion for time-limited transportation problem on-demand (MCCETLTPD) is to find such a practicable capacity expansion transportation scheme satisfying the time-limited T along with all origins’ supply and all destinations’ demands as well as the expanding cost is minimum. Actually, MCCETLTPD is a balance transportation problem and a variant problem of minimum cost maximum flow problem. In this paper, by creating a mathematical model and constructing a network with lower and upper arc capacities, MCCETLTPD is transformed into searching feasible flow in the constructed network, and consequently, an algorithm MCCETLTPD-A is developed as MCCETLTPD’s solution method basing minimum cost maximum flow algorithm. Computational study validates that the MCCETLTPD-A algorithm is an efficient approach to solving the MCCETLTPD.
