钢箱单勒系杆拱桥施工阶段索力优化研究

文章针对国内少有的刚构钢箱单勒系杆拱桥,以在建的某桥为工程背景,对其施工阶段的吊杆索力进行了确定,运用影响矩阵法来确定施工阶段第二次吊杆张拉控制力,实现了仅在张拉2次吊杆的情况下,就使各吊杆索力达到成桥状态设计值,为预制拼装类施工的单勒拱桥吊杆张拉提供了实践经验.     

从某一微车气囊设计探讨安全气囊标定技术

文章以某一微车安全气囊设计为基础,详细阐述汽车设计中气囊标定整车碰撞试验矩阵确定的依据、气囊标定对车辆状态的要求及气囊标定核心——点火控制的原理,从而得出准确的标定报告,以指导设计生产。     

Limitations of portfolio diversification through fat tails of the return Distributions: Some empirical evidence

This study investigates the level of risk due to fat tails of the return distribution and the changes of tail fatness (TF) through portfolio diversification. TF is not eliminated through portfolio diversification, and, interestingly, the positive tail has declining fatness until a certain level is reached, while the negative tail has rising fatness. This indicates that fat tails are highly relevant to common factors on systematic risk and that the relevance of common factors is higher for the negative tail compared to the positive tail. In the portfolio diversification effect, the declining fatness of the positive tail further reduces risk, but the rising fatness of the negative tail does not contribute to this effect. The asymmetry between the fatness of the positive and negative tails in the return distribution corresponds to the asymmetry of the trade-off relationship between loss avoidance and profit sacrifice that is expected as a consequence of portfolio diversification. Investors use portfolio diversification to reduce their risk of suffering high losses, but following this strategy means sacrificing high-profit potential. Our study provides empirical confirmation for the practical limitation of portfolio diversification and explains why investors with diversified portfolios suffer high losses from market crashes. An examination of the Northeast Asian stock markets of China, Japan, Korea, and Taiwan show identical results.     

秩幂等矩阵的特征

如果n阶方阵A满足秩(A2)=秩(A),那么称A为秩幂等矩阵.利用线性代数的方法研究秩幂等矩阵的性质,得到了秩幂等矩阵的一些充要条件,揭示了秩幂等矩阵A的值域、核子空间与线性空间Pn的联系.     

我国第三方支付沉淀资金监管的博弈论分析

国内电子商务的迅猛发展导致第三方支付业务交易量增加显著。它在给人们带来极大便利的同时,也引起人们对相应第三方支付行业中大笔沉淀资金的挪用及账户中产生利息的归宿问题的关注。近期央行采取颁发营业牌照的措施以抬高第三方支付业务准入门槛,进一步引发人们对第三方支付业务中存在的诸多问题的讨论。本文通过分析沉淀资金的形成、积累及利用和相应利息的配置,借用博弈分析方法对支付矩阵进行推导,在加强第三方支付行业沉淀资金监管的基础上,针对性提出央行应给予第三方支付机构适度利用沉淀资金的权利、沉淀资金利息多样化配置、构建评价体系、促进信息公开化的观点。     

Hospital economic impact from hemostatic matrix usage in cardiac surgery

Objective:

Improved health outcomes can result in economic savings for hospitals and payers. While effectiveness of topical hemostatic agents in cardiac surgery has been demonstrated, evaluations of their economic benefit are limited. This study quantifies the cost consequences to hospitals, based on clinical outcomes, from using a flowable hemostatic matrix vs non-flowable topical hemostatic agents in cardiac surgery.

Research design and methods:

Applying clinical outcomes from a prospective randomized clinical trial, a cost consequence framework was utilized to model the economic impact of comparator groups. From that study, clinical outcomes were obtained and analyzed for a flowable hemostatic matrix (FLOSEAL, Baxter Healthcare Corporation) vs non-flowable topical hemostats (SURGICEL Nu-Knit, Ethicon–Johnson &; Johnson; GELFOAM, Pfizer). Costing analyses focused on the following outcomes: complications, blood transfusions, surgical revisions, and operating room (OR) time. Cardiac surgery costs were analyzed and expressed in 2012 US dollars based on available literature searches and US data. Comparator group variability in cost consequences (i.e., cost savings) was calculated based on annualized impact and scenario testing.

Results:

Results suggest that if a flowable hemostatic matrix (rather than a non-flowable hemostat) was utilized exclusively in 600 mixed cardiac surgeries annually, a hospital could improve patient outcomes by a reduction of 33 major complications, 76 minor complications, 54 surgical revisions, 194 transfusions, and 242?h of OR time. These outcomes correspond to a net annualized cost consequence savings of $5.38 million, with complication avoidance as the largest contributor.

Conclusions:

This cost consequence framework and supportive modeling was used to evaluate the hospital economic impact of outcomes resulting from the usage of various hemostatic agents. These analyses support that cost savings can be achieved from routine use of a flowable hemostatic matrix, rather than a non-flowable topical hemostat, in cardiac surgery.     

Cost–consequence analysis of a hemostatic matrix alone or in combination for spine surgery patients

Background: A five-year retrospective database analysis comparing the use of Floseal¹ flowable topical hemostat alone (F) and in combination with gelatin/thrombin (F?+?G/T) to achieve hemostasis and control surgical bleeding showed higher resource utilization for F?+?G/T cases relative to F matched pairs during spinal surgery. Lower resource use in the F group was characterized by shorter hospital length of stay and surgical time as well as fewer blood transfusions and less hemostat agent used per surgery.

Objective: To evaluate the cost–consequence of using F compared to F?+?G/T in minor, major and severe spinal surgery from the US hospital perspective.

Methods: A cost–consequence model was developed using the US hospital perspective. Model inputs include clinical inputs from the literature, cost inputs (hemostatic matrices, blood product transfusion, hospital stay and operating room time) from the literature, and an analysis of annual spine surgery volume (minor, major and severe) using the 2012 National Inpatient Sample (NIS) database. Costs are reported in 2017?US dollars. One-way and probabilistic sensitivity analyses address sources of variability in the results.

Results: A medium-volume hospital (130 spine surgeries per year) using F versus F?+?G/T for spine surgeries is expected to require 85 less hours of surgical time, 58 fewer hospital days and 7 fewer blood transfusions in addition to hemostat volume savings (F: 1?mL, thrombin: 1994?mL). The cost savings associated with the hospital resources for a medium-volume hospital are expected to be $317,959 (surgical hours?=?$154,746, hospital days?=?$125,237, blood transfusions?=?$19,023, hemostatic agents?=?$18,953) or $2445 per spine surgery.

Conclusions: The use of F versus F?+?G/T could lead to annual cost savings for US hospitals performing a low to high volume of spinal surgeries per year.     

生态资本化理论视角下的循环经济生态创新体系研究

循环经济生态创新的本质就是促进经济社会的可持续发展,以维持生态资本存量非减性作为其发展的生态基础。本文首先介绍了循环经济生态创新的内涵,分析探讨了生态资本与循环经济生态创新的关联性,以此确定生态资本化下循环经济生态创新的价值取向,以此为基础,构建一个循环经济生态化技术创新、生态化制度创新、生态化金融创新以及生态化观念创新"四位一体"循环经济生态创新体系。     

INCOME DISTRIBUTIONS IN INPUT-OUTPUT MODELS

The analysis of income distribution (ID) has traditionally been of prime importance for economists and policy-makers. However, the standard input–output (I–O) model is not particularly well equipped for studying current issues such as the consequences of decreasing access to primary inputs or the effects of specific redistributive policies. This paper addresses this gap in the existing literature. We propose that IDs can excellently be studied by restructuring the I–O relations. A new coefficients matrix is defined, the so-called augmented input coefficients matrix. This matrix is the sum of the intermediate input coefficients matrix and newly constructed matrices of sector-specific input coefficients that represent the existing distribution of income. We show that shifts in the distribution can be modelled by attributing weights to these matrices and vary these according to system-specific rules. Numerical illustrations based on the existing literature are given throughout the paper.     

基于现代设计方法学的平面研磨机设计

针对现有大回转半径平面研磨机整机重、效率低的问题,采用现代设计方法学为指导,给出了平面研磨机的黑箱模型和整机功能的形态学矩阵,依据形态学矩阵设计了多工位、大回转半径平面研磨机系统方案,并讨论了主要的研磨参数.