Community response to environmental noise and the impact on cardiovascular risk score

Objective

The objective of our study was to investigate and evaluate the relationship between road traffic noise and cardiovascular risk.

Methods

The study sample (n = 659; 36.9% male, 63.1% female university students, mean age 22.83 ± 1.58 years) included a group exposed to road traffic noise (n = 280, L_eq,24 h = 67 ± 2 dB(A)) and a control group (n = 379, L_eq,24 h = 58.7 ± 6 dB(A)). Subjective response was determined by a validated noise annoyance questionnaire. The ten year risk of developing a coronary heart disease event was quantified as an evaluation of cardiovascular risk (SCORE60, Framingham 10-year risk estimation and projection to the age of 60, relative risk SCORE chart).

Results

Cardiovascular risk scores were significantly higher in the exposed group based on the Framingham scores projected to the age of 60, SCORE60 (AOR = 2.72 (95% CI = 1.21-6.15)) and the relative risk SCORE chart (AOR = 2.81 (1.46-5.41)).

Conclusions

These findings highlight the association between road traffic noise and cardiovascular risk.     

Evaluation of a new alkaline/microbe/polymer flooding system for enhancing heavy oil recovery

The new alkaline/microbe/polymer (AMP) flooding system was first constructed and evaluated for enhancing oil recovery. The system is composed of 0.3?wt% Na₂CO₃, 2?wt% microbial cultures and 0.2?wt% polymer. Compared with the conventional alkaline/surfactant/polymer (ASP) system, the AMP system exhibits identical displacement properties. Chromatography analysis reveals crude oil is not negatively affected by the microbes in AMP system. Further comparative core flooding experiments using the AMP and ASP systems demonstrate that the AMP system possesses greater potential for enhancing heavy oil recovery, which shows the characteristic of two-stage additional oil increment with total additional oil recovery of 17.11%–19.91%.     

求解线性互补问题的区间AOR方法

将AOR方法与区间理论相结合,给出了一种求解线性互补问题的区间方法——IAOR方法,并对系数矩阵为正对角的H矩阵时,证明了该算法收敛的几个充分性条件.最后给出了几个数值实例,通过与其它区间算法相比说明了该IAOR方法的有效性.     

双α-对角占优矩阵与AOR迭代法的收敛性定理

对系数矩阵为严格双α-对角占优矩阵的情况,推广了解线性方程组的AOR迭代法,获得了AOR方法收敛的实用条件。推广了已有结果,并用数值例子说明了本文结论的实用性。     

奇异p-循环阵块AOR迭代的半收敛性

讨论了用块AOR迭代法解决线性方程组的系数矩阵为奇异p-循环阵的半收敛性问题.首先用外插迭代给出了用块AOR迭代法解线性方程组系数阵为奇异p-循环阵半收敛的一些充分条件,然后在合理的假设条件下给出一个数值例子对结论加以验证.     

The AOR Iterative Method for Preconditioned Linear Systems

In Ref.[1], two preconditioned methods for linear system Ax = b (1) are introduced, where nnAC×∈ ,nb∈ C are given and nx ∈ C is unknown. It is given as the following preconditioned methods. The preconditioned linear system A~ x= b~ (2) where A~ = (I S~)A, and b~ = (I S~)b with S~=????????????? 000000001LMMMMLLna and the preconditioned linear system A =(3) 0where I is the identity matrix, L and U are strictly lower and upper triangular matrices obtained from A, respectively. The c…     

Production rescheduling for machine breakdown at a job shop

Rescheduling is a procedure to repair a production plan affected by unexpected disruptions. It is important because a production schedule released to a shop floor is subject to unexpected disruptions. This paper develops two novel heuristic rescheduling procedures, AWI-J and AWI-O, to minimise mean tardiness of jobs in a job shop. The procedures are based on an active schedule-generation procedure and Wilkerson–Irwin algorithm, which is well known for minimising mean tardiness of a schedule. The performances of the new procedures are compared with those of the Affected Operations Rescheduling (AOR) procedure, which is popular in the rescheduling literature. Efficiency measures such as mean tardiness, mean flowtime, and makespan, and a stability measure, deviation of new operation start times from the original start times, are used for comparison. Test results show that AWI-J improves efficiency over AOR, and AWI-O improves efficiency and stability as well.     

求解线性系统的新预条件子及比较定理

本文提出了一种求解大规模线性系统的新预条件子,并从理论上证明了对AOR迭代法而言,新预条件子优于两类已知的预条件子,文中所得收敛性比较定理推广了已有结果.文尾给出的数值算例也充分验证了这种新预条件子的有效性.     

AOR与Jacobi迭代矩阵关系研究

给出AOR加速松弛）迭代与Jacobi迭代在广义相容次序（q,p-q）矩阵下,（p,q）＝（2,1）情形的迭代矩阵之间的一个等式．     

严格对角占优Z-矩阵的多级预条件AOR迭代法

为了加快线性方程组的迭代法求解速度,提出了一类新预条件子,分析了相应的预条件AOR迭代法的收敛性。给出了当系数矩阵为严格对角占优的Z-矩阵时,AOR和预条件AOR迭代法收敛速度的比较结论。同时也给出了多级预条件迭代法的相关比较结果,推广了现有的结论。数值算例验证了文中结果。