基于简单度和能量的心音分段算法研究

研究诊断心血管病,结合形象化,利用图像检测,提高诊断水平。心音分段是心音图分析的一个重要环节。分段效果将直接影响心脏疾病的诊断水平。为了提高心音的分段正确率,根据动力学复杂性原理,提出一种简单度和归一化平均香农能的心音分段算法。对于复杂多样的心音信号,算法不仅分段正确率高,而且还能准确计算出第一心音和第二心音的时限。通过对144例正常心音和异常心音信号进行分段仿真实验,结果表明,算法是一种有效的和鲁棒性强的心音分段技术,为后期心音信号的识别奠定了良好的基础。

On the Total Domination Number of Graphs with Minimum Degree at Least Three

Let G be a simple graph with no isolated vertices. A set S of vertices of G is a total dominating set if every vertex of G is adjacent to some vertex in S . The total domination number of G , denoted by γ t (G) , is the minimum cardinality of a total dominating set of G . It is shown that if G is a graph of order n with minimum degree at least 3, then γ t (G)≤n/2 . Thus a conjecture of Favaron, Henning, Mynhart and Puech is settled in the affirmative.

Effect of vertical overturning circulation scale and moist static energy tendency on MJO phase speed

The combined effects of vertical overturning circulation(VOC) zonal length scale and moist static energy(MSE)tendency zonal asymmetry on MJO phase speed were investigated based on diagnosis of ERA-Interim data over a 40-year period(1979-2019).In a key region(80°-100°E),128 MJO events were selected.It was found that the larger the VOC zonal length scale,the faster the MJO eastward propagation.The correlation coefficient between them was 0.52,exceeding the 99% confidence level.A significant positive correlation(0.59) was also identified between the phase speed and MSE tendency zonal asymmetry.A linear regression model based on the aforementioned two parameters was constructed,and the phase speed could be estimated based on the model.The correlation coefficient between the reconstructed phase speed and its observed counterpart was 0.73,exceeding the 99% confidence level with an F-test.A composite analysis of the fast and slow groups indicated that the VOC zonal length scale was modulated by the background state.An El Nino(La Ni?a)-like SST pattern and associated precipitation anomalies promoted a larger(smaller) VOC zonal length scale and thus a faster(slower)propagation speed.A sensitivity test with a reference point in a different longitudinal zone(120°-140°E) was conducted.Again,there were significant relationships between the MJO phase speed and the two parameters.The correlation between the reconstructed and observed phase speed was 0.67,exceeding the 99% confidence level.

The Perception of Small- and Medium-Sized Enterprises （SMEs） on the Importance of a Proper Accounting System： Malaysian Evidence

This paper examines the relationship between small- and medium-sized enterprises＇ （SMEs） entrepreneurs＇ perceptions towards a proper accounting system with the level of accounting staff recruited, preparation of final accounts, meetings with accounting staff, and entrepreneurs＇ ranking of accounting according to their priority. The methodology used to gather the data is survey questionnaire. It has been distributed to SMEs based on simple random sampling method. Three hundred businesses were selected from the total of 3,390 businesses listed in Kuala Lumpur, Malaysia area obtained from Small and Medium Industries Development Corporation （SMIDEC） website and a few random selected from Ampang and Cheras areas. Regression analysis has been used to analyze the data. The results of the study reveal that there was a significant relation between SMEs entrepreneurs＇ perceptions on the importance of a good accounting system and the level of professional accounting staff recruited. Furthermore, findings of this study also found that there was an insignificant relationship between SMEs entrepreneurs＇ perceptions on the importance of a good accounting system and preparation of final accounts of the company and frequency of meetings with accounting staff.

热带地区几个珍贵树种干形曲线研究

准确描述热带珍贵树种的林木干形变化,可为预估各材种数量、蓄积量及合理造材提供支撑。以热带格木、红锥和柚木3个珍贵树种,共120株解析木为研究对象,利用简单削度方程、分段削度方程和可变指数削度方程分别构建格木、红锥和柚木3个热带树种的干形曲线方程,通过相关指数、剩余残差平方和、平均残差、残差方差和均方误差统计量比较分析,找出最佳削度模型作为3个树种最终的干形曲线方程,并对各曲线变化趋势进行了初步的定量分析。结果表明,所选的3类典型基础模型对每个树种的预估效果都很好,其中基于双因素自动优选法拟合且以分段削度方程构建的干形曲线预估效果最好。3个树种的干形曲线变化趋势表明：相对高在（0-0.8）时,柚木干形变化最大,红锥干形变化最小,格木干形介于二者之间;当相对高〉0.8时,红锥干形变化最大,格木和柚木干形变化几乎相同。因此,基于双因素自动优选法拟合的分段削度方程可作为3种热带树种的干形曲线方程,用于3种珍贵树种活立木蓄积量和材种数量的估计,以及指导合理造材。

Minimal Elements in the Poset of Graphic Sequences

A nonincreasing sequence ( of n nonnegative integers is said to be graphic if it is the degree sequence of a simple graph G of order n. The set of all graphic sequences of n terms with even sum 2m and trace f is a poset G_(n,m,f) under majorization relation. The paper characterizes the minimal elements in the poset G_(n,m,f) and determines the number of minimal elements in various posets of graphic sequences.

区域价值链嵌入有利于降低我国境内增加值碳排放成本吗--基于制造业数据实证分析

当今国际分工模式下全球价值链呈现更多区域化特征,积极嵌入区域性价值链成为各经济体破解低端锁定局势的重要手段。本文构建了区域价值链的简单嵌入度和复杂嵌入度指标,且推导出增加值境内碳排放成本测算方法。研究了2000-2014年中国制造业对欧盟、北美、东亚、金砖四大区域的嵌入度对境内增加值碳排放成本的影响,结论如下:(1)提升区域价值链简单嵌入度增加了中国制造业增加值境内碳排放成本,尤其中国嵌入欧盟、东亚地区以资源型高碳型行业为主,其影响效应更为显著。(2)提升区域价值链复杂嵌入度,利于降低中国境内增加值碳排放成本,但金砖地区例外。(3)四大区域价值链嵌入度对制造业增加值境内碳排放成本的影响具有行业异质性。提升高技术制造业区域价值链嵌入度均利于降低境内碳排放成本;低技术制造业只有提升其复杂嵌入度水平才能降低成本实现制造业绿色转型。

Comparisons of Metrics on Teichmller Space

For a Riemann surface X of conformally finite type （g, n）, let dT, dL and dpi （i = 1, 2） be the Teichmuller metric, the length spectrum metric and Thurston＇s pseudometrics on the Teichmutler space T（X）, respectively. The authors get a description of the Teichmiiller distance in terms of the Jenkins-Strebel differential lengths of simple closed curves. Using this result, by relatively short arguments, some comparisons between dT and dL, dpi （i = 1, 2） on Tε（X） and T（X） are obtained, respectively. These comparisons improve a corresponding result of Li a little. As applications, the authors first get an alternative proof of the topological equivalence of dT to any one of dL, dp1 and dp2 on T（X）. Second, a new proof of the completeness of the length spectrum metric from the viewpoint of Finsler geometry is given. Third, a simple proof of the following result of Liu-Papadopoulos is given： a sequence goes to infinity in T（X） with respect to dT if and only if it goes to infinity with respect to dL （as well as dpi （i = 1, 2））.

On the solutions of an oxygen absorption model

In this note we present the Adomian decomposition method for solving a simple model for the diffusion and absorption of oxygen in tissue. The method is examined for computational efficiency and accuracy.