Possible contribution of artificial neural networks and linear discriminant analysis in recognition of patients with suspected atrophic body gastritis

AIM: To investigate whether ANNs and LDA could recognize patients with ABG in a database, containing only clinical and biochemical variables, of a pool of patients with and without ABG, by selecting the most predictive variables and by reducing input data to the minimum.METHODS: Data was collected from 350 consecutive outpatients (263 with ABG, 87 with non-atrophic gastritis and/or celiac disease [controls]). Structured questionnaires with 22 items (anagraphic, anamnestic, clinical, and biochemical data) were filled out for each patient. All patients underwent gastroscopy with biopsies. ANNs and LDA were applied to recognize patients with ABG.Experiment 1: random selection on 37 variables, experiment 2: optimization process on 30 variables, experiment 3:input data reduction on 8 variables, experiment 4: use of only clinical input data on 5 variables, and experiment 5:use of only serological variables.RESULTS: In experiment 1, overall accuracies of ANNs and LDA were 96.6% and 94.6%, respectively, for predicting patients with ABG. In experiment 2, ANNs and LDA reached an overall accuracy of 98.8% and 96.8%,respectively. In experiment 3, overall accuracy of ANNs was 98.4%. In experiment 4, overall accuracies of ANNs and LDA were, respectively, 91.3% and 88.6%. In experiment 5, overall accuracies of ANNs and LDA were,respectively, 97.7% and 94.5%.CONCLUSION: This preliminary study suggests that advanced statistical methods, not only ANNs, but also LDA,may contribute to better address bioptic sampling during gastroscopy in a subset of patients in whom ABG may be suspected on the basis of aspecific gastrointestinal symptoms or non-digestive disorders.

A Structured Mesh Euler and Interactive Boundary Layer Method for Wing/Body Configurations

To compute transonic flows over a complex 3D aircraft configuration, a viscous/inviscid interaction method is developed by coupling an integral boundary-layer solver with an Eluer solver in a ＂semi-inverse＂ manner. For the turbulent boundary-layer, an integral method using Green＇s lag equation is coupled with the outer inviscid flow. A blowing velocity approach is used to simulate the displacement effects of the boundary layer. To predict the aerodynamic drag, it is developed a numerical technique called far-field method that is based on the momentum theorem, in which the total drag is divided into three component drags, i.e. viscous, induced and wave-formed. Consequently, it can provide more physical insight into the drag sources than the often-used surface integral technique. The drag decomposition can be achieved with help of the second law of thermodynamics, which implies that entropy increases and total pressure decreases only across shock wave along a streamline of an inviscid non-isentropic flow. This method has been applied to the DLR-F4 wing/body configuration showing results in good agreement with the wind tunnel data.

Relevance of zero lift drag coefficient and lift coefficient to Mach number for large aspect ratio winged rigid body

Synthetic analysis is conducted to the wind tunnel experiment results of zero lift drag coefficient and lift coefficient for large aspect ratio winged rigid body.By means of wind tunnel experiment data,the dynamics model of the zero lift drag coefficient and lift coefficient for the large aspect ratio winged rigid body is amended.The research indicates that the change trends of zero lift drag coefficient and lift coefficient to Mach number are similar.The calculation result and wind tunnel experiment data all verify the validity of the amended dynamics model by which to estimate the zero lift drag coefficient and lift coefficient for the large aspect ratio winged rigid body,and thus providing some technical reference to aerodynamics character analysis of the same types of winged rigid body.

A computational study of the wing-wing and wing-body interactions of a model insect

The aerodynamic interaction between the contralateral wings and between the body and wings of a model insect are studied, by using the method of numerically solving the Navier-Stokes equations over moving overset grids, under typical hovering and forward flight conditions. Both the interaction between the contralateral wings and the interaction between the body and wings are very weak, e.g. at hovering, changes in aerodynamic forces of a wing due to the present of the other wing are less than 3% and changes in aerodynamic forces of the wings due to presence of the body are less than 2%. The reason for this is as following. During each down- or up-stroke, a wing produces a vortex ring, which induces a relatively large jet-like flow inside the ring but very small flow outside the ring. The vortex rings of the left and right wings are on the two sides of the body. Thus one wing is outside vortex ring of the other wing and the body is outside the vortex rings of the left and right wings, resulting in the weak interactions.

The role of climate factors in geographic variation in body mass and wing length in a passerine bird

Background: Geographic variation in body size is assumed to reflect adaptation to local environmental conditions. Although Bergmann's rule is usually sufficient to explain such variation in homeotherms, some exceptions have been documented. The relationship between altitude, latitude and body size, has been well documented for some vertebrate taxa during the past decades. However, relatively little information is available on the effects of climate variables on body size in birds.Methods: We collected the data of 267 adult Eurasian Tree Sparrow(Passer montanus) specimens sampled at 48 localities in China's mainland, and further investigated the relationships between two response variables, body mass and wing length, as well as a suit of explanatory variables, i.e. altitude, latitude, mean annual temperature(MAT), annual precipitation(PRC), annual sunshine hours(SUN), average annual wind speed(WS), air pressure(AP) and relative humidity(RH).Results: Our study showed that(1) although the sexes did not differ significantly in body mass, males had longer wings than females;(2) body mass and wing length were positively correlated with altitude but not with latitude;(3) body mass and wing length were negatively correlated with AP and RH, but not significantly correlated with WS. Body mass was positively correlated with SUN and inversely correlated with MAT. Wing length was not correlated with MAT in either sex, but was positively correlated with SUN and negatively correlated with PRC in male sparrows;(4) variation in body mass could be best explained by AP and SUN, whereas variation in wing length could be explained by RH and AP in both sexes. In addition, variation in male sparrows can be explained by SUN, WS and PRC but not in females.Conclusions: Two different proxies of body size, body mass and wing length, correlated with same geographic factors and different climate factors. These differences may reflect selection for heat conservation in the case of body mass, and for efficient flight in the case of wing length.

Wing/body kinematics measurement and force and moment analyses of the takeoff flight of fruitflies

In the paper, we present a detailed analysis of the takeoff mechanics of fruitflies which perform voluntary takeoff flights. Wing and body kinematics of the insects during takeoff were measured using Based on the measured data, high-speed video techniques. inertia force acting on the insect was computed and aerodynamic force and moment of the wings were calculated by the method of computational fluid dynamics. Subtracting the aerodynamic force and the weight from the inertia force gave the leg force. The following has been shown. In its voluntary takeoff, a fruitfly jumps during the first wingbeat and becomes airborne at the end of the first wingbeat. When it is in the air, the fly has a relatively large ＂initial＂ pitch-up rotational velocity （more than 5 000~/s） resulting from the jumping, but in about 5 wingbeats, the pitch-up rotation is stopped and the fly goes into a quasi-hovering flight. The fly mainly uses the force of jumping legs to lift itself into the air （the force from the flapping wings during the jumping is only about 5%-10% of the leg force）. The main role played by the flapping wings in the takeoff is to produce a pitch-down moment to nullify the large ＂initial＂ pitch-up rotational velocity （otherwise, the fly would have kept pitching-up and quickly fallen down）.

EXPERIMENTAL STUDY OF TURBULENT WINGBODY JUNCTION AND WAKE FLOW

The experiments on wing-body junction and wake flow were carried cul in alow-turbulence level wind tunnel. Intensive measurements of various flow parameters,such as the distributions of the pressure on the surfaces of the airfoil and the plate wall,the mean and the fluctuating velocities, as well as the turbulent kinetic energy, u'v' andu'w'etc., were performed. The results indicate that the secondary flow entrains the highvelocity low-turbulence fluid into the boundary layer and the wake vortex dominates thewake flow. Some regions of negative eddy viscosity are also found in the wake flow.

SUPPORTING AND SEPARATING SUBSETS FOR INVEX BODIES

Invex bodies represent an important class of bodies which are considered as a generalization of convex bodies.In this article,the author studies the supporting for this class of bodies as well as the separating subsets of two bodies.

创新教育背景下工业设计专业“一体两翼四驱动”教学模式研究

近年来,国家倡导素质教育,提倡在高等院校加大实践能力和创新能力的培养,各高校不断进行教学模式改革和创新,取得了一定成效,但仍没能摆脱传统观念和教学模式的束缚。为适应行业发展趋势和需求,坚持以人为本的教育理念,紧跟时代步伐,引入“一体两翼四驱动”教学模式,开展“一体两翼四驱动”协同育人改革实践,以培养高素质创新复合型人才为主要目的,增强学生实践能力和创新能力,从根本上提升人才培养质量,以满足高速发展的社会需求,为高校人才培养模式变革提供参考依据。

高职院校助力职教“一体两翼”高质量发展研究

“一体两翼”是新时代职业教育高质量发展的有效策略,落实职业教育“一体两翼”发展策略具有现实逻辑内涵和重要实践价值。高职院校是职业教育改革发展的重要推动力量,虽然高职院校助力职教“一体两翼”高质量发展取得一系列成效,然而,因受到多种因素的影响和制约,高职院校助力职教“一体两翼”高质量发展仍面临不少挑战。因此,为了增强高职院校助力职教“一体两翼”高质量发展效能,应该立足省域发展,开展针对性专业人才培养;多维度建设市域产教联合体,创设高职教育发展新平台;多方协同发力,全方位推进行业产教融合共同体建设。

新型农业经营主体会计代理采用意愿及其影响因素实证分析

会计代理可以节约用工成本、提高效率和促进经营目标的实现,是当前推动新型农业经营主体财务规范的重要过渡阶段。基于湖北省891份调研数据,采用有序Logistic模型检验新型农业经营主体采用会计代理意愿的影响因素。结果表明:性别、年龄、受教育水平、流动资金投资、经营类型、产业类型、毛收入、示范级别、农业培训等因素显著影响新型农业经营主体采用会计代理意愿。据此提出加强经营主体会计知识培育,强化财务规范意识,夯实会计代理基础;建立资金管理台账,关注资金流向,推动会计代理行业发展;设立专项资金支持,提供会计代理对接服务,扩大会计代理行业覆盖面等建议。

下肢康复减重支撑系统的结构设计与分析

面向我国脑卒中和老龄化等原因导致的下肢运动功能障碍患者,开发了一种基于人体足底压力分布和重心轨迹的双腋支撑下肢康复减重系统。首先,分析研究了减重支撑训练对足底压力的影响;其次,基于人机工程学理论并结合人体重心轨迹研究,对总体结构进行了分析与设计,并确定了相关尺寸;然后,通过静力学分析,验证了结构的可靠性;最后,对减重模块进行了运动学分析和动力学仿真。该系统可帮助下肢运动功能障碍的患者实现模仿正常人行走的康复训练。

加快构建辽宁“一体两翼”对外开放新格局

辽宁是东北亚开放的窗口和“一带一路”建设的重要节点,加快构建“一体两翼”对外开放新格局是辽宁深化改革、扩大开放、实现高质量发展和全面振兴全方位振兴的重要举措。从贸易开放、资金开放、技术开放、社会开放四个维度构建“一体两翼”对外开放效果评价体系,采用因子分析法对2021年我国内地31个省份对外开放度进行评价,结果显示:辽宁对外开放度在全国处于较低水平,外贸外资因子、教育文化因子和旅游因子得分显著低于广东、上海和浙江,是影响辽宁对外开放水平的主要因素。从外资外贸、教育文化、旅游方面的主因子视角和对接国际高标准规则优化营商环境,加强区域合作开放平台建设,完善国际合作交通网络等政策方面,提出加快构建辽宁“一体两翼”对外开放新格局的对策建议。

一体两翼内外相维:明代中枢政治结构之再认识

作为帝制中国政治制度的核心部分,中枢政治结构的变革呈现出“因袭与演变”的重要特点。明代中枢政治结构的发展,经历了“皇帝—丞相”的“一对一模式”和“皇帝—六部”的“一对多模式”,最终形成了“皇帝—内阁、司礼监”的“一对二模式”,这是明朝不同于以往任何朝代的中枢决策系统。从纵向结构来看,明代中枢政治结构形成了一种立体的金字塔型结构,皇帝无疑处在权力的最顶峰;就横向分层而言,分居皇权之下的司礼监和内阁互相制约,形成“一体两翼,内外相维”的权力结构。

“一体两翼六驱动”发展型资助育人模式探析

党的十九大以来,以习近平同志为核心的党中央高度重视学生资助工作。党的十九大报告明确提出要“健全学生资助制度”。新时代学生资助工作的重点应由单纯的经济保障转变为经济保障与育人发展相结合,使育人功能成为学生资助工作的价值引领。聚焦当前时期学生资助工作,通过“一体两翼六驱动”探索发展型资助育人模式。

“一体两翼三环四创”沉浸式课程思政教学模式探索与实践——体育科学研究方法课程思政创新报告

从发现和解决课程思政教学过程中真实问题的角度出发,体育科学研究方法构建了“一体两翼三环四创”沉浸式课程思政教学模式,即以学生为主体,教学团队和导师团队为两翼,在课前、课中、课后3个环节,通过创新思政技术、思政供给、思政空间和思政场景,对学生的思想意识、情感态度和言行举止产生积极影响。该模式秉承以学生为中心的“三全育人”教育理念,将思政教育与专业教育紧密结合,引导学生立大志、明大德、成大才、担大任,最终完成立德树人之根本任务,为党和国家培养有用之才。实践表明,“一体两翼三环四创”沉浸式课程思政教学模式较好地解决了以往教学中存在的痛点问题,在实现“三全育人”和课程思政与知识传授、能力培养互融互促的三维立体教学目标方面取得了良好成效。

中文国际传播视域下国际中文教育人才培养模式建构——以三亚学院为例

展现可信、可爱、可敬的中国形象,推动中华文化更好地走向世界,增强中华文化传播力、影响力的关键是语言相通,让世界上更多的人理解中文。中文国际传播的历史使命对国际中文教育相关专业的人才培养提出了更高要求。笔者针对当前国际中文教育人才培养模式同质化问题,依据高质量人才需求,在三亚学院经过多年实践探索,构建出本科阶段适应中文国际传播需求的“一体两翼三融通”国际化、复合型人才培养模式即以新时代国际中文教育人才培养为主体,以语言文化教育、语言文化传播实践转化为两翼,以中外语言文化融通、信息技术与职业技能融通、对内与对外双向传播融通为支撑,是解决当前国际中文教育人才培养痛点的有效举措。

身体意象对中学生社交焦虑的影响:有调节的中介模型

目的:分析身体意象与中学生社交焦虑之间的关系,以及自悯在其中的中介作用和社会支持的调节作用。方法:采用身体意象状态量表、中文版交往焦虑量表、简版自悯量表以及青少年社会支持量表对1174名中学生进行调查。结果:(1)身体意象显著负向预测中学生社交焦虑(β=-0.36,P<0.001);(2)自悯在身体意象与中学生社交焦虑之间起部分中介作用,中介效应占比46.88%;(3)社会支持在中介作用的后半段起调节作用,即随着社会支持的提高,自悯对社交焦虑的负向预测作用增强(社会支持低分组β=-0.27,P<0.001 vs社会支持高分组β=-0.40,P<0.001)。结论:身体意象不仅可以直接预测中学生社交焦虑,还可通过自悯间接对中学生社交焦虑产生影响,社会支持在这一中介作用的后半段起调节作用。

翼身融合布局飞机分布式推进边界层吸入效应影响研究

翼身融合布局是指机翼和机身高度融合的全升力面飞机外形,在提升巡航效率和减排降噪等方面展现出明显的性能优势和发展潜力.采用雷诺平均Navier-Stokes方法结合基于叶素理论的体积力模型,针对翼身融合布局民机分布式推进边界层吸入(BLI)效应影响下的绕流流场进行了数值研究.首先,将翼身融合布局民机分布式BLI推进构型简化为涵道风扇-机翼段耦合构型,计算涵道风扇质量流率小于1、等于1以及大于1的3个工况,对比分析了滑移网格方法、冻结转子方法和基于叶素理论的体积力模型法的流场细节、计算精度以及计算效率.其次,建立分布式BLI推进-机翼耦合构型,对此构型不同转速下的绕流流场进行对比分析,探究并验证所建立的分布式BLI推进系统抑制分离的能力.最后,将分布式BLI推进安装于翼身融合布局飞机概念方案NPU-BWB-300机翼与机身的融合段,探究其对NPU-BWB-300绕流流场的影响.研究结果表明:滑移网格方法、冻结转子方法和基于叶素理论的体积力模型方法均可以较好地刻画涵道风扇边界层吸入效应的流场细节;所建立的分布式BLI推进系统具备抑制分离的能力,将其应用于NPU-BWB-300也可以取得较为明显地改善分离流场的效果.

蝴蝶飞行机理及仿蝴蝶扑翼飞行器研究进展综述

仿生扑翼飞行器具有高机动性、高隐蔽性以及高效率等突出优势,在军事侦查、探险搜救等领域具有较好的应用前景,而其应用的基础是对生物飞行机理的深入探究.随着先进运动观测和实验技术的引入,对昆虫飞行行为的记录和分析更为便捷和准确.研究表明常见的昆虫拍打频率较高,在25~400 Hz之间,而蝴蝶较为特殊,其扑打频率较低,大约为10 Hz,对于蝴蝶的许多独特的飞行技能尚缺少足够的认识.蝴蝶前翼和后翼的翼面积都较大,身体同侧的前后翼几乎为同步拍打,且扑打幅度较大,甚至接近180°.蝴蝶飞行中身体有较大幅度的上下和俯仰震荡,翼和身体运动高度耦合.即便如此,蝴蝶仍具有敏捷的飞行能力,可以达到点对点的飞行目标,甚至上千公里的长途迁徙,是优秀的仿生学研究对象.因此,蝴蝶启发的仿生扑翼飞行器也得到了全世界研究人员的关注.蝴蝶的飞行机制相对于其他昆虫更加特殊,飞行行为和气动特性更为复杂,这使得仿蝴蝶扑翼飞行器的研制更加困难.目前对于仿蝴蝶飞行器的研制大多数对蝴蝶翼–身耦合的机理进行了简化,很少能实现受控的稳定飞行.最后,本文梳理了真实蝴蝶的飞行行为特点和飞行机理,指出了仿蝴蝶扑翼飞行器研制的关键技术,总结了该类飞行器未来的发展方向和应用前景.