Stability and Bifurcation Analysis of Man-machine System with Time Delay

A mathematical model of man-machine system is considered.Based on the reference [4],the direction and stability of the Hopf bifurcation are determined using the normal form method and the center manifold theory.Furthermore,the existence of Hopf-zero bifurcation is discussed.In the end,some numerical simulations are carried out to illustrate the results found.

Research on menu-typed man-machine interaction system of digital TIG welding machine

A digital man-machine interaction system controlled by communications between two processors of TMS320F240 and AT98C2051 was researched in the paper. The system is easy to set and modify welding process parameters by keyboards, and display information of welding site by LCD (Liquid Crystal Display). As one part of multi-task system about TIG welding machine, the coordination of man-machine interaction system with other tasks is the main point to the stability and reliability of its operation. Experiments result indicates that the system is stable, operation-flexible, high precision, and anti-interfering.

Man-machine Relationship Analysis Based on Dashboard Similar Structure Design

Dashboard similar structure design is a kind of interactive design of ergonomics and industrial design, and also the consistency design of functional features and visual organization effect of dashboard. Functional feature design of dashboard is the analysis of man-machine interface, and visual organization effect design of dashboard is a branch of industrial design, both of them interact and unite.

Research of Integration Method of Interpersonal Teaching and Man-machine Teaching in College English

with the rapid development of hi-tech at present, the college English curriculum teaching of higher education in our country faces an inevitable deep reform and innovation. In order to effectively improve the English application ability of undergraduates, this paper analyzes the integration of interpersonal teaching and man-machine teaching in college English, illustrates the connotation and the current situation of interpersonal and man-machine teaching and makes deep research of integration of these two teaching modes. The author proposes to fully exert the features and advantages of interpersonal teaching and multi-media teaching and hopes to improve the teaching quality of college English through the analysis and research of this paper.

Research on the Man-machine Interactive Environment VR and the Applications on Vocational Education and Training under the Perspective of Interactivity

In this paper, we conduct research on the man-machine interactive environment VR and the applications on vocational educationand training under the perspective of interactivity. With the increase in the general standard of social knowledge level and competition intensifi es,more and more people have a goal to build a lifelong learning system, according to their own hobbies, work and the needs of the marketcompetition. Under this condition, the vocational education is becoming more and more essential. This paper integrates the VR and man-machineinteractive concept to propose the new education paradigm that is innovative.

Research on the Man-Machine Engineering Theory and the Applications on Furniture Design and Interior Decoration Design

In this paper, we conduct research on the man-machine engineering theory and the applications on furniture design and interior decoration design. Furniture is one of the important media, contacts and relationships between building it by their own different shape and size provide comfortable environment for people. Ergonomics is the study of human activity and the claim size on the surrounding environment, how to make furniture to better serve people＇ s life and work. Our research proposed novel paradigm of the man-machine engineering theory which is meaningful.

快速路交织区车头时距分布特征

针对快速路交织区中车流的频繁交织行为引发车头时距重分布现象,系统研究了快速路交织区车头时距分布的内在规律,得出了城市快速路交织区内车头时距分布随断面流率动态变化的结论。选择北京、上海、广州等7个典型城市的城市快速路系统为研究对象,利用数理统计方法对采集的代表性快速路中A类交织区中车头时距数据进行分车道分断面统计分析,拟合分析及x^2检验的结果表明断面流率小于250 veh/h时,车头时距服从负指数分布;当断面流率位于250～750 veh/h时,车头时距服从移位负指数分布,而当断面流率位于750～1500 veh/h时,车头时距则服从Cowan M3分布,为城市快速路交织区的通行能力分析、规划管理等方面的深入研究提供了理论依据。

我国经济型轿车柴油机的发展策略

详细分析了柴油机轿车的发展历史、柴油机轿车的优点、柴油机轿车的市场以及轿车柴油机的特点和当前所处的技术水平情况,阐述了经济型轿车柴油机及其发展前景,通过对国内现状的分析指出了我国开展经济型轿车柴油机研究和开发的必要性,最后,从市场定位、产品定位、开发方式和技术方案等几个方面出发提出了我国发展经济型轿车柴油机的策略。

混氢对怠速工况发动机循环变动和排放的影响

针对汽油机怠速时循环变动大、排放高的问题,在一台加装了电控氢气喷射系统的1.6L汽油机上就混氢对发动机怠速性能的影响进行了试验研究。在怠速条件下,通过自主开发的电子控制单元调整氢气与汽油的喷射脉宽,使进气中混氢体积分数从0%逐渐增加至6.52%,同时减少汽油的喷射脉宽,以保证混氢后发动机仍工作在理论过量空气系数条件下。试验结果表明,混氢后发动机火焰发展期和快速传播期缩短;平均指示有效压力的循环变动系数由原机的9.97%减少至混氢体积分数为6.52%时的4.93%。NOx排放随混氢分数增加而减少;在混氢体积分数小于4.88%时,HC与CO随混氢比的增加而减少,但当混氢分数大于4.88%时,HC与CO排放再次升高。

城市道路基础地理要素编码方法研究

对城市道路基础地理要素——路口及路段的编码方法进行了研究。从分析现有编码的方法及问题入手,结合现代化城市智能交通管理的需求,提出考虑地理要素空间位置的基于地理网格的编码方法,详细分析了该编码方法的思路和具体内容并对比分析了该方法的优势和特点。基于本方法的城市道路基础地理要素编码可以应用于城市道路交通系统的规划、建设及管理等领域,同时为推动城市道路基础地理信息的共享和交换提供了支持。

颅内动脉瘤手术废弃脑组织中成人自体神经干细胞的培养与鉴定

背景:对胎儿、胎鼠及成鼠神经干细胞培养已有大量研究,但成体人自体神经干细胞培养相关研究较少。目的:通过改进原代培养方法,从颅内动脉瘤破裂脑出血患者血肿腔周边废弃脑组织中培养和鉴定神经干细胞,并进行冻存与复苏研究,建立成人自体神经干细胞库。方法:收集3例动脉瘤破裂脑出血(2例大脑中动脉瘤及1例前交通动脉瘤)手术中血肿腔周边的废弃脑组织各约500 mg以上,采用细小组织块接种法进行原代无血清悬浮培养成人自体神经干细胞,倒置显微镜下观察细胞生长情况,免疫荧光细胞化学技术检测神经干细胞标志物巢蛋白(Nestin)的表达。培养获得的神经干细胞球以体积分数4%胎牛血清诱导其贴壁生长,待细胞增殖达到一定数量后传代培养。传代后部分细胞予以冻存建库,并复苏继续传代及诱导分化培养。体积分数10%胎牛血清诱导神经干细胞分化,通过免疫荧光细胞化学技术检测胶质纤维酸性蛋白(标记星形胶质样细胞),β-tubulinⅢ(标记神经元样细胞),SOX10(标记少突胶质样细胞)蛋白的表达来测定神经干细胞的分化能力。结果与结论:改进培养方法后,3例患者废弃脑组织中,在无血清培养液中均可形成Nestin阳性表达的神经球,并可在体外大量扩增和连续传代。在给予体积分数10%FBS条件下神经球可分化为神经元样细胞、少突胶质细胞及星形胶质细胞,即β-tubulin Ⅲ,SOX10及胶质纤维酸性蛋白阳性表达。经传代培养至5代后,仍呈Nestin阳性即可维持其神经干细胞特征。冻存细胞复苏后生长状态良好且呈Nestin阳性,可继续传代扩增。结果表明,从动脉瘤破裂脑出血患者不同脑区(颞极及额底)血肿腔周边废弃脑组织中可成功培养获得自体神经干细胞,并可向神经元样细胞、少突胶质样细胞及星形胶质样细胞分化,使自体神经干细胞移植促进神经功能修复从实验室到临床应用成为可能。

工科数学教学改革的探索

根据国家教委高教司（94）208号文件精神，结合自己几年来的教学实践，就普通高校工科数学教学改革中的一些问题以及应采取的措施与对策进行了探讨。

对比与探讨:教育改革思路的调整

对比与探讨：教育改革思路的调整毛晋１９８８年９月邓小平同志的两次谈话中英明地指出：“马克思说过，科学技术是生产力，事实证明这话讲得很对。依我看科学技术是第一生产力。”同时还指出：“从长远看要注意教育和科学技术”。“我们要千方百计，在别的方面忍耐一些，...

内燃机机体变形原因分析及改进

以某六缸柴油机为例,介绍了机体在制造加工、组装和使用中产生的变形;从设计、铸造及机械加工诸方面对变形原因及影响因素进行了分析,并介绍了所采取的改进措施和收到的效果;最后提出建议:在设计上应对机体的应力值做出具体规定。

壳聚糖藻酸盐支架与脂肪间充质干细胞复合构建的组织工程脊髓修复急性脊髓损伤

背景:组织工程化脊髓为脊髓损伤的修复带来了新的治疗思路。目的:探讨壳聚糖藻酸盐支架与脂肪间充质干细胞复合的组织工程脊髓修复大鼠急性脊髓损伤的效果。方法:取48只SD大鼠,建立脊髓半横断模型,随机分4组干预,模型组直接缝合硬膜,细胞组在脊髓断端周边移植脂肪间充质干细胞,支架组在脊髓损伤区植入壳聚糖藻酸盐支架,实验组在脊髓损伤区植入组织工程脊髓(壳聚糖藻酸盐支架与CM-Dil标记脂肪间充质干细胞复合物)。移植后1,3,7周,评估大鼠后肢运动功能;移植后7周取脊髓标本,进行免疫荧光染色和苏木精-伊红染色。结果与结论:(1)后肢运动功能:移植后3,7周,实验组后肢运动功能强于模型组、细胞组及支架组(P<0.05),细胞组、支架组后肢运动功能强于模型组(P<0.05);(2)免疫荧光染色:模型组无神经丝蛋白200、神经元特异性烯醇化酶、胶原纤维酸性蛋白阳性细胞;支架组可见神经元特异性烯醇化酶阳性细胞、胶原纤维酸性蛋白阳性细胞及少量神经丝蛋白200阳性细胞;细胞组未见神经丝蛋白200、神经元特异性烯醇化酶阳性细胞,可见大量的胶原纤维酸性蛋白阳性细胞;实验组见大量神经元特异性烯醇化酶阳性细胞,少量CM-Dil标记的脂肪间充质干细胞、较多的胶原纤维酸性蛋白阳性细胞及神经丝蛋白200阳性细胞;(3)苏木精-伊红染色:模型组有大量成纤维细胞和炎性细胞浸润,有较大的脊髓空洞;支架组无脊髓空洞,脊髓和支架材料之间连接紧密;细胞组有脊髓空洞;实验组无脊髓空洞,脊髓损伤区有各种形态细胞形成;(4)结果表明:壳聚糖藻酸盐支架与脂肪间充质干细胞复合的组织工程脊髓,可促进急性脊髓损伤的修复。

双点火及补气对摩托车发动机性能影响的研究

针对摩托车发动机经济性差、排放高的问题,笔者在一台加装了双火花塞和进气补气系统的单缸摩托车发动机上,在不同转速条件下,就双火花塞点火和补气对内燃机燃烧与排放特性的影响进行了试验研究。试验结果表明,采用双点火配合进气补气的方法可以有效降低发动机CO、HC排放及比燃油消耗率。在转速为3500r.min-1的条件下,采用双点火配合进气补气的发动机比燃油消耗率较原机降低约12.5%。在发动机转速高于3000r.min-1时,采用双点火也可以在一定程度上改善发动机经济性并降低CO和HC排放。但NOx排放在双点火条件下较原机略有升高。

高温燃料流量调节发拉瓦尔管口特性分析(英文)

600～700℃高温下,冲压发动机所用燃油为完全气态。为解决气态燃料在高温下的流量精确调节,设计新式燃料流量调节阀,对流经发动机进气道的燃料进行调节。对拉瓦尔管阀口特性进行研究,采用FLUENT仿真软件,分析流经阀口的气态燃料速度及压力的分布,从而找出流量变化规律。研究结果表明,采用拉瓦尔管状阀口的流量调节阀,阀芯位移和入口压力不变时,改变出口压力,流经阀口的燃料流量保持不变。

Man-machine Function Allocation Based on Uncertain Linguistic Multiple Attribute Decision Making

Function allocation is one of the necessary stages in the design course of man-machine systems since appropriate function allocation makes the whole system more effective, reliable and inexpensive. Therefore, our research mainly focuses on the problems of function allocation between man and machine in man-machine systems, analyses each capability advantage of man and machine according to their respective inherent characteristics and makes a comparison between them. In view of highly uncertain characteristics of decision attribute value in the practical process, we introduce the uncertain linguistic multiple attribute decision making （ULMADM） method in the function allocation process. Meanwhile, we also use the uncertain extended weighted arithmetic averaging （UEWAA） method to determine the automation level range of the operator functions. Then, we eventually estab- lish the automation level of man-machine function allocation by using the multi-attribute decision making algorithm, which is combined by UEWAA and uncertain linguistic hybrid aggregation （ULHA） operators. Finally, an example about function allocation is given, that is, fault diagnosis in the cockpit of civil aircraft. The final result of the example demonstrates that the proposed method about function allocation is feasible and effective.

Man-machine verification of mouse trajectory based on the random forest model

Identifying code has been widely used in man-machine verification to maintain network security.The challenge in engaging man-machine verification involves the correct classification of man and machine tracks.In this study,we propose a random forest(RF)model for man-machine verification based on the mouse movement trajectory dataset.We also compare the RF model with the baseline models(logistic regression and support vector machine)based on performance metrics such as precision,recall,false positive rates,false negative rates,F-measure,and weighted accuracy.The performance metrics of the RF model exceed those of the baseline models.

Analysis of Drivers＇Burden and Man－Machine Interfaces in High－Speed Locomotive Driving Cab

With the introduction of high-speed trains into chinese railway system, closeattention should be paid to the aspects of safety in hish-speed railways. Thereare many interfaces which are very important and directly related to drivmgsafety. This paper focuses on features of design and analyses the principles ofsafety.