Determination of a Cut-Off Point of a Scale for Achievement Motive in Geriatrics That Predicts the Frequency of Undertaking Instrumental Activities of Daily Living in Community-Dwelling Elderly People

Background: Among elderly people, rehabilitation is important for reducing the risk of falls and hospitalization and to maintain an independent life for longer. Motivation is a factor for elderly people to lead an active daily life and leave home more frequently. Purpose: The purposes of this study were to determine the optimal cut-off point in the Scale for Achievement Motive in Geriatrics (SAMG) that could identify individuals as inactive or active, based on the Frenchay Activities Index (FAI), and to compare characteristics between active and inactive groups classified by the cut-off point. Methods: A cross-sectional study of 285 community-dwelling elderly people measured SAMG and FAI and physical function. Receiver operating characteristic (ROC) analysis was used to calculate the area under the curve (AUC) that was the optimal cut-off point for the SAMG total score, with the associated sensitivity and 1-specificity when compared with the FAI results. Demographic parameters and physical function were compared between two groups defined by cut-off point. Results: The AUC was 0.78, the optimal cut-off for SAMG total score for indicating inactivity was ≤48, the sensitivity was 77.98% and the 1-specificity was 75.00%. The group with SAMG score >48 was characterized by a significantly higher proportion of women, fewer people sharing a house, and participation in more hobbies. Discussion: A cut-off point of 48 in the SAMG could be a predictive index of motivation toward goals for individuals with inactive daily activities. The group with score higher than the cut-off was characterized by more women, fewer people living together, and more hobbies than the group with lower scores.

Is the present cut-point to define type 2 diabetes appropriate in Latin-Americans?

The diagnosis of diabetes mellitus type 2(DM2) is based either on increased plasma glucose or Glycated hemoglobin levels. Since these measures are the only means for diagnosis of DM2, they must be well adapted to each population according to their metabolic characteristics, given that these may vary in each population. The World Health Organization(WHO) determined the cut-points of plasma glucose levels for the diagnosis of DM2 by associating hyperglycemia with the risk of a specific microvascular complication-retinopathy. Cardiovascular diseases are however the principal causes of mortality in patients with DM2 and we reported that in the Colombo-Ecuadorian population impaired fasting glucose and impaired glucose tolerance are both riskmarkers for myocardial infarction. We propose that the current cut-points accepted by the WHO need to be revaluated in populations such as Latin America and that there should be lower cut points for glycaemia in this population, to reduce the prevalence of cardiovascular complications associated with DM2.

Investigation of Surface Micro Waviness in Single Point Diamond Fly Cutting

Single point diamond fly cutting is widely used in the manufacture of large-aperture ultra-precision optical elements. However,some micro waviness( amplitude about 30 nm,wavelength about 15 mm) along the cutting direction which will decrease the quality of the optical elements can always be found in the processed surface,and the axial vibration of the spindle caused by the cut-in process is speculated as the immediate cause of this waviness. In this paper,the analytical method of dynamic mesh is applied for simulating the dynamic behavior of the vertical spindle. The consequence is then exerted to the fly cutter and the processed surface profile is simulated. The wavelength of the simulation result coincides well with the experimental result which proves the importance of the cut-in process during the single point diamond fly cutting.

The Characteristics of Glued Tensile Shear Strength Constituted of Wood Cut by CO_(2) Laser

The performance of engineered wood products is highly associated with proper bonding and an efficient cutting method.This paper investigates the influence of CO_(2) laser cutting on the wetting properties,the modified che-mical component of the laser-cut surface,and the strength and adhesive penetration near the bondline.Beech-wood is cut by the laser with varying processing parameters,cutting speeds,gas pressures,and focal point positions.The laser-cut samples were divided into two groups,sanded and non-sanded samples.Polyvinyl acetate adhesive(PVAc)was used to bond the groups of laser-cut samples.After assembly with cold pressing,the tensile shear test was carried out.Numerical modelling was carried out to determine the partial elongation and shear strain of the glue line.Based on this,the shear modulus and linear elasticity of the glue line were estimated.Scan-ning electron microscopy was used to assess the adhesive penetration into the porosity structure of the laser-cut samples,and the depth of the heat-affected zone.The laser-cut surface was analysed by Fourier transform infrared spectroscopy.The wetting properties of the laser-cut surface were investigated by using a contact angle goni-ometer.The numerical model of the strain-stress curve confirmed the experimental model.The highest modulus of the linear elasticity of the glue in the numerical calculation belongs to the joint containing laser-cut samples at a gas pressure of 21(bar).The penetration depth of PVAc adhesive into the porosity structure of the laser-cut sam-ples was similar to that of sawn samples.The deepest heat-affected zone in the laser-cut samples was 150µm.A PVAc drop disappeared immediately on the laser-cut surface without sanding,but gradually on the sanded surface.In contrast,the drop on the sawn surface remained with an angle of 32°–48°.The degradation of hemi-cellulose and lignin was proven by the lower intensity of the C=O and C-O Bonds,compared to the sawn surface.

基于改进超体素与图割的室内场景点云分割

室内场景点云分割是三维场景感知、理解、分析及应用的基础。尽管目前的室内点云分割方法可以应用于很多场景,但缺乏对不同结构分割的适应性,在处理临近平行面的分割时,仍无法避免欠分割,因此,本文提出了一种基于改进超体素与图割的方法。首先通过对超体素的邻域选择、法向量计算、特征距离度量,以及对超体素局部邻接图的空间连通性约束与分割,构建出自适应处理临近平行面关系的机制,实现复杂室内场景点云的有效分割,克服欠分割现象;最后通过4组室内场景点云进行验证,并与现有方法进行对比分析。结果表明,本文方法提高了复杂室内场景点云分割的精确率和召回率,验证了其对不同结构分割的适应性和有效性。

基于点云数据的大型复杂钢结构智能化施工方法

大型复杂钢结构施工过程中,常面临施工尺寸质量难以把控、构件提升变形监测困难和合拢段现场配切效率低等问题。三维激光扫描技术可全覆盖地、快速精准地获取复杂构部件在施工过程中的点云数据,这为解决上述问题提供了新方法。为此,该文以重庆两江新区寨子路钢拱桥为工程背景,开展基于点云数据的大型复杂钢拱桥智能化施工方法的全流程研究。基于标靶球检测算法、快速四点一致集算法、迭代最近邻算法等实现标靶球点云数据的自动检测及多站点云数据之间的自动配准;通过BIM点云化技术、kNN算法等完成目标点云数据的半自动化提取,实现拱肋尺寸的智能化检测;基于八叉树算法、区域增长算法等实现拱肋提升变形的智能检测;为缩短拱肋的合拢工期,基于BIM模型焊缝信息提取技术、主成分分析算法、Canny边界检测算法、霍夫变换算法等提出数字化预拼装算法,得到合拢段的配切量。工程应用表明,该文所提出的智能施工方法效率高、自动化程度好,研究成果可为大型复杂钢结构的施工质量和安装效率的提升提供理论和算法支撑。

基于Ncut的SIFT特征匹配算法

经典尺度不变特征变换(SIFT)特征匹配算法存在实时性差、纹理相似区域易发生误匹配的问题。为此,提出一种基于归一化分割(Ncut)的SIFT特征匹配算法。针对相同背景的运动视频,将归一化分割算法的图论聚类思想融入SIFT特征匹配中,根据运动趋势相似度对特征点进行Ncut运动聚类,再逐类分别匹配,通过缩小各特征点匹配过程中的搜索范围,减少匹配时间及不同特征类之间的误匹配。实验结果表明,该算法能提高匹配效率,对纹理相似区域的误匹配现象有较好的抑制作用,实现了相邻图像帧的特征稳定匹配。

不同肥胖指标对中老年人群糖尿病的筛检效果研究

目的探讨中老年人群不同肥胖指标对糖尿病的筛检效果,并确定不同肥胖指标的最优切点值及最适指标,为糖尿病的早期筛检及防控提供数据支撑和科学依据。方法对12630名45~79岁某医院体检人群进行问卷调查和体格检查,采用ROC曲线确定最适指标及最优切点值,Delong检验比较不同肥胖指标对糖尿病的筛检效果,logistic回归评估不同切点下不同肥胖指标的预测效果。结果(1)糖尿病患病率男性高于女性;(2)不同性别腰围身高比指标的ROC曲线下面积均最大,且腰围、腰围身高比的ROC曲线下面积与身体质量指数、腰臀比的ROC曲线下面积均有显著差异;(3)不同切点下,腰围和腰围身高比有更高的OR值和ROC曲线下面积。结论对于中老年人群而言,腰围和腰围身高比相比于其他指标对糖尿病有更好的筛检能力和预测效果。

粗纱物理特性对环锭纺细纱机后区牵伸效果影响

为探究粗纱在细纱后区的形态变化和粗纱物理特性能对细纱后区牵伸效果的影响,以不同粗纱定量、捻度和纤维长度的粗纱为例,分析粗纱截面纤维分布、粗纱定量和捻度等物理特性对粗纱拉伸强力影响、粗纱须条在牵伸区的变化以及基于等长切断称重法分析牵伸效果。结果表明:在牵伸过程中粗纱须条截面从圆形变成扁平带状后又恢复成一定紧密度的类圆形;粗纱定量为450 g/(10 m),捻度为4.01和4.48捻/m的粗纱力学性能好,利用粗纱捻回产生的附加摩擦力界能有效控制纤维的运动,牵伸区内纤维变速点集中,牵伸效果好;大定量粗纱受罗拉胶辊差速影响易发生纤维分层,纤维变速点分散,需加大罗拉钳口压力予以改善;后区牵伸倍数在1.10~1.36倍以内,有利于牵伸稳定。

数控刀具技术与应用探析

数控刀具是切削加工的基础工艺装备,在制造过程中与数控机床相互配合承载不同的加工工艺,共同完成材料切削加工。针对数控刀具的选用,探讨了选用要点,并以具体数控车加工为例进行了刀具的选用,以促进数控刀具更好地发展与应用。

单线小曲线切翼缘简支箱梁施工技术研究

主要研究了在高铁车站出站口变线处及其他特殊周边环境下曲线半径过小导致梁缝的宽度过大不能保证线路的平顺性,以及由于桥梁景观的要求而进行的箱梁特殊设计及施工的问题。分析了在曲线半径过小的情况下,桥梁设计中的处理原则和方法,以及在预制过程中模板设计的要点、支座板的位置、接地端地的位置、接触网及下锚拉线的位置、桥面无砟轨道预埋套筒的位置、钢筋尺寸、张拉力的变化等质量控制要点。

基于点云数据的切坡建房风险评价——以武汉市低山丘陵区为例

针对武汉市低山丘陵区的切坡建房风险区,本文采用机载激光雷达(LiDAR)生成坡面山体点云数据,大面积排查区域内的房屋建筑,降低人为参与程度,提高切坡建房判断精度,同时运用区域生长法、坡度计算等方法,结合武汉市地质灾害隐患排查标准,建立武汉市切坡建房风险等级评价体系,并采用点云剖面计算、实地勘察的方式进行准确度验证。结果表明,依据本文算法提取的风险区成果与点云剖面计算、实地勘测的风险等级一致,所得结果与削坡高度、边坡距离、自然坡长的误差分别在-0.2~1 m、-1.3~2.7 m、-1~2 mm之间;坡度误差在-1°~7°之间;容积率误差在-0.07~0.53之间;与实地勘测的拟合度在0.9以上。因此,基于点云数据建立的切坡建房风险等级评价体系可从不同角度对地貌特征进行分析,大大节约人力和物力,为武汉市地质灾害及隐患调查数据的获取提供参考。

云存储系统中文件分界点确定方法——Cut-GAR

针对Hadoop分布式文件系统(HDFS)中小文件定义模糊导致HDFS处理小文件性能不佳的问题,提出了一种云存储系统中文件分界点的确定方法——Cut-GAR。该方法分析消耗Name Node内存(M)、文件上传速度(MUFS)、文件读取速度(MAFS)与文件大小之间的关系,得出文件大小三个近似最优值,FM、FMUFS、FMAFS;然后利用灰度关联分析,将M、MUFS、MAFS作为评价指标,文件大小作为评价对象,得到评价指标-评价对象灰色关联度以及评价指标所占权重,将FM、FMUFS、FMAFS与对应权重相乘,得出文件分界点。实验结果表明,Cut-GAR在M、MUFS和MAFS三者之间取得平衡,可以有效确定文件分界点,提升小文件处理性能。

The Influence Law of Oil Relative Permeability on Water Cut

Water cut is a key evaluation parameter for reservoir development evaluation. Relative permeability curve reflects reservoir characteristics and fluid characteristics. It is important to figure out the influence law of oil relative permeability on water cut. Based on the 269 relative permeability curves of Bohai oilfields, the distribution of oil index of Bohai oilfields were studied. On the basis, combined with Corey expression of relative permeability and fractional flow equation, the theoretical relationship between oil index and water cut increasing rate was established. Three end points of water cut increasing rate curve were proposed and the influence law between three end points and oil index was studied. The results show that the oil index has a linear relationship with three end points. When the value of water oil mobile ratio is large than 1, with the increase of oil index, maximum value of water cut increasing rate gradually increase. When the value of water oil mobile ratio is less than 10, oil index has great effect on recovery percent when water cut increasing rate reaches to the maximum value as well as water cut when water cut increasing rate reaches to the maximum value. The application of SS field shows that the theoretical value is consistent with the field data.

Method to determine installing angle of conical point attack pick

In order to obtain the determining method of the installing angle and decrease the performance indices (cutting force and wearing rate) of the pick, the relationships among the installing angles (impact angle, inclination angle and the skew angle) were studied, and the static model of installing angles of the pick was built. The relationships among the impact angle, the tip angle of pick and the kinematics parameters of the pick were built, too. Moreover, the mechanic models of the maximum clearance angle and the wearing angle of the pick were set up. To research the relationships of the installing angles and the change law of the wearing angle along with the kinematics parameters, the simulation was done. In order to verify the correctness of the models, the cutting experiments were done by employing two picks with different pick tip angles. The results indicate that, the cutting force is the smallest when the direction of the resultant force of pick follows its axis, and the relationship derived among the installing angles should be satisfied. In addition, to decrease the cutting force and the wearing of the pick, the tip angle of pick should not be larger than the half of the difference between the minimum wearing angle and the impact angle of the pick, and the clearance angle must not be less than zero.

基于Cutting Tool的FANUC激光切割系统研制

传统的激光切割多数采用五轴CO_2激光切割机,占地面积大,柔性差,设备采购及维护成本居高不下。为此,设计了基于Cutting Tool的FANUC激光切割系统,该系统包含Cutting Tool技术、离线编程技术、图形生成技术、工具中心点速度输出技术等多种关键技术,拓展了机器人激光切割系统的应用领域,为工业用户提供了一种新的技术解决方案。

The Use of Genetic Approach to the Kinematics of Cutting

This article deals with the use of an interdisciplinary approach to modelling and creation of a complex technical system of different physical nature in relation to the kinematics of cutting and shaping. The professor of the National Technical University of Ukraine, Kuznetcov Iu. N., proposed the approach based on generalization of knowledge, methodological basis of which is the theory of evolution of the systems and methods of genetic analysis and synthesis. For generalization of the knowledge in the fundamental sciences is based on the principles of a limited number of elementary generic structures with the introduction of the gene concept. The modelling and synthesis of kinematic cutting schemes are providing the efficiency and viability of genetic and morphological approach. The material point, which can interact with other ma-terial points in space and time, simulating anthropogenic system of different origin, is introduced as a material object.

渤海C油田预钻井原油乳化对储层伤害实验研究

渤海C油田导管架期间首批12口预钻井在生产过程出现了生产压差高产量低的现象,分析认为原油乳化堵塞是潜在伤害因素。为了明确原油乳化堵塞机理,为产能恢复措施制定提供指导,针对该批低产井开展原油乳化堵塞实验研究。实验结果表明:当含水率为20%时,原油乳状液黏度为最高值10.9 mPa·s,为原油乳化反相点,乳状液类型为油包水(W/O)型;当含水率大于20%时,乳状液黏度降低,类型为水包油(O/W)型;原油高含水时,乳状液类型为O/W型,降低储层渗透率25.21%,对储层伤害相对较小;原油低含水时,乳状液类型为W/O型,降低储层渗透率75.01%,对储层伤害大。随着乳状液质量浓度从1000 mg·L^(-1)增加至4000 mg·L^(-1),岩心渗透率伤害程度最高达到50%。以I01H和I28H井为例,结合实验结果对实际生产动态进行分析,两口井生产初期含水率升高至20%后,生产压差不变,采液指数下降,说明原油发生乳化并堵塞近井地层,与实验结果一致。

范成法加工渐开线齿轮的根切机制研究

通过建立标准齿条刀具齿廓曲线方程,使用VB.NET编程语言在AutoCAD环境下进行二次开发,开发了范成法加工渐开线齿轮和根切全过程动态模拟程序,进一步研究和探索齿轮根切过程和根切机制,并精确求解出最大根切半径。更正了最大根切半径等于被加工齿轮回转中心到刀具齿顶线与啮合线交点间距离的错误结论。在此基础上,重新确定了变位系数选择封闭线图中的根切至大、小齿轮齿廓工作段起始点时的限制条件,确定了大、小齿轮齿根处发生干涉的限制条件,从而可准确绘制出变位系数选择封闭线图。