Optimization of Center of Gravity Position and Anti-Wave Plate Angle of Amphibious Unmanned Vehicle Based on Orthogonal Experimental Method

When the amphibious vehicle navigates in water,the angle of the anti-wave plate and the position of the center of gravity greatly influence the navigation characteristics.In the relevant research on reducing the navigation resistance of amphibious vehicles by adjusting the angle of the anti-wave plate,there is a lack of scientific selection of parameters and reasonable research of simulation results by using mathematical methods,and the influence of the center of gravity position on navigation characteristics is not considered at the same time.To study the influence of the combinations of the angle of the anti-wave plate and the position of the center of gravity on the resistance reduction characteristics,a numerical calculation model of the amphibious unmanned vehicle was established by using the theory of computational fluid dynamics,and the experimental data verified the correctness of the numerical model.Based on this numerical model,the navigation characteristics of the amphibious unmanned vehicle were studied when the center of gravity was located at different positions,and the orthogonal experimental design method was used to optimize the parameters of the angle of the anti-wave plate and the position of the center of gravity.The results show that through the parameter optimization analysis based on the orthogonal experimental method,the combination of the optimal angle of the anti-wave plate and the position of the center of gravity is obtained.And the numerical simulation result of resistance is consistent with the predicted optimal solution.Compared with the maximum navigational resistance,the parameter optimization reduces the navigational resistance of the amphibious unmanned vehicle by 24%.

Fundamental Options for Designing Transmission Systems Supplying Metropolitan Centers

Transgression networks in metropolitan centers need to supply a large quantity of power in a reliable manner to vital loads that are located within. A transmission network supplying such an important area must have a high standard of reliability. Therefore, those transmission systems require a special form of redundancy in order to prevent sustained outages after severe contingencies such as multiple faults. This paper outlines different forms of redundancy, and the fundamental options for designing a metropolitan network based on different forms of redundancy are illustrated. Relative merits and drawbacks of network designs based on each form of redundancy are also shown.

OPTIMIZING DESIGN OF MECHANICAL SELF-CENTERING DEVICE FOR SUSPENSION HEIGHT

Firstly,in view of the respective defects of existing self-centering devices for vehicle suspension height,the design scheme of the proposed mechanical self-centering device for suspension height is described.Taking the rear suspension of a certain light bus as a research example,the structures and parameters of the novel device are designed and ascertained.Then,the road excitation models,the performance evaluation indexes and the half-vehicle model are built,the simulation outputs of time and frequency domain are obtained with the road excitations of random and pulse by using MATLAB/Simulink sofiware.So the main characteristics of the self-centering suspension are presented preliminarily.Finally,a multi-objective parameter design optimization model for the self-centering device is built by weighted sum approach,and optimal solution is obtained by adopting complex approach.The relevant choosing-type parameters for self-centering device components are deduced by using discrete variable optimal method,and the optimal results are verified and analyzed. So the performance potentials of the self-centering device are exerted fully in condition of ensuring overall suspension performances.

An Innovative Architectural Strategy for the Integration of Energy Issues into the Design Process of a Commercial Center in Switzerland

In a context of growing efforts to develop sustainability strategies, energy-related issues occupy central stage in the built environment. Thus, the energy performance of housings has improved radically over the past decades. Yet other types of buildings, in particular commercial centers, haven’t received the same level of interest. As a result, there is a need for effective and practical measures to decrease their energy consumption, both for heating and electricity. The objective of the paper is to demonstrate that it is possible, through coherent strategies, to integrate energy issues and bioclimatic principles into the design process of commercial centers. It analyzes the exemplary case study of Marin Commercial Center (Switzerland). The interdisciplinary approach, based on integrated design strategies, aimed at increasing the energy efficiency while keeping the cost comparable to the market cost. The main design principles include natural ventilation, nighttime cooling with energy recovery and natural lighting, as well as optimization of mechanical systems. The results of the simulations show that Marin Center attains the best energy performance observed so far among Swiss commercial centers. It also meets the Swiss Minergie standard. The paper thus questions traditional design processes and outlines the need for interdisciplinary evaluation and monitoring approaches tailored for commercial centers. Even though most crucial decisions are taken during the early stages, all phases of the process require systematic optimization strategies, especially operating stages. Recommendations include legal measures, in particular in the fields of ventilation and air-conditioning, education, professional development and technology transfer, and financial incentives for the replacement of energy intensive installations.

Multi-Hazard Evaluation Using Cluster Analysis—For Designated Evacuation Centers of Yokohama

Hazard maps are usually prepared for each disaster, including seismic hazard maps, flood hazard maps, and landslide hazard maps. However, when the general public attempts to check their own disaster risk, most are likely not aware of the specific types of disaster. So, first of all, we need to know what kinds of hazards are important. However, the information that integrates multiple hazards is not well maintained, and there are few such studies. On the other hand, in Japan, a lot of hazard information is being released on the Internet. So, we summarized and assessed hazard data that can be accessed online regarding shelters (where evacuees live during disasters) and their catchments (areas assigned to each shelter) in Yokohama City, Kanagawa Prefecture. Based on the results, we investigated whether a grouping by cluster analysis would allow for multi-hazard assessment. We used four natural disasters (seismic, flood, tsunami, sediment disaster) and six parameters of other population and senior population. However, since the characteristics of the population and the senior population were almost the same, only population data was used in the final examination. From the cluster analysis, it was found that it is appropriate to group the designated evacuation centers in Yokohama City into six groups. In addition, each of the six groups was found to have explainable characteristics, confirming the effectiveness of multi-hazard creation using cluster analysis. For example, we divided, all hazards are low, both flood and Seismic hazards are high, sediment hazards are high, etc. In many Japanese cities, disaster prevention measures have been constructed in consideration of ground hazards, mainly for earthquake disasters. In this paper, we confirmed the consistency between the evaluation results of the multi-hazard evaluated here and the existing ground hazard map and examined the usefulness of the designated evacuation center. Finally, the validity was confirmed by comparing this result with the ground hazard based on the actual measurement by the past research. In places where the seismic hazard is large, the two are consistent with the fact that the easiness of shaking by actual measurement is also large.

User Centered Design for Battlefield Screen

This thesis paper is a brief summary of user centered design, (particularly in the situation of under the battlefield), which incorporates the related information after reviewing many other papers. A display screen user requires an ability to provide proper information while considering a variety of information in a short period. While operating the display screen, the user is heavily pressed for time as the missions are allocated through many different steps of orders. In addition, since a failure would cause fatal damage or cause further defeat, this increases the pressure of time. The right environment for operating a display screen is most useful when the user is in the most vulnerable time period or long-term continuous operation of the display screen. In that kind of sterile environment, the operating display screen is there to help the user’s decisions for the matter at hand, in this it should follow the user centered design and improve the user’s handiness and use. Furthermore, the information should be provided in accordance with the user's informational and perceptional process, and the capacity of the information process should be improved with the movement through each process and step. This thesis paper can be used as a reference material when designing the display screen in order to apply a user’s experiences.

Finite Element Analysis and Optimal Design Based on ANSYS in a XH2408 Gantry Style NC Machining Center

ANSYS,the software of construction analysis,is used to analyze static and dynamic performances of a XH2408 gantry style numerical control (NC) milling machining center and optimize its construction using the finite element method.First,a finite element model is established and the static and dynamic analysis are completed as constraints and loads applied on the finite element model.It is found that both spindle box and gantry are the worst components of assembly in performance.Secondly,the spindle box and gantry are chosen as objects of optimal design separately,aiming to improve their performance.The optimal plans are accomplished on the basis of the minimum volume for the spindle box and the maximum inherent frequency for the gantry subject to the constrains.Finally,the machine tool improved is analyzed statically and dynamically based on the optimal results of the spindle box and gantry.The results show that optimal design with the finite element method increases static and dynamical performances of the XH2408 gantry style numerical control milling machining center and the technique is effective and practical in engineering applications.

Optimization Design for Fixed Table of Gantry Machining Center Based on Sensitivity and Topology Analyses

In order to decrease the deformation and stress and increase the natural frequency of the fixed table,a method of optimization driven by the sensitivity and topology analyses is proposed.The finite element model of the fixed table is constructed and analyzed by using ANSYS software.Based on the results of static analysis and modal analysis,the maximum deformation,the maximum stress,and natural frequencies are obtained.Then,the sensitivity analysis and topology optimization are carried out to find out the parameters to be optimized.The fixed table is reconstructed according to optimal design scheme.In the comparison of the results between original model and the optimized one,the maximum deformation and stress are decreased by 71.73%and 60.27%respectively.At the same time,the natural frequencies from the first mode to the sixth mode are increased by 30.28%,29.57%,29.51%,31.52%,22.19%,and 21.80%,respectively.The method can provide technology guide for the design and optimization of machining structure.

Simplified Method of Designing FIR Filter with Controllable Center Frequency

A novel simplified method is presented to design FIR filter with controllable center frequency. The properties of transfer curves for all-phase filters are illustrated under 3 windowing conditions. By combining single-window all-phase filter design steps and double phase-shift combination, a series of design formulas for point-pass filter, notch filter, band-pass filter and band-stop filter are derived, thus the design computation complexity is greatly reduced. Experiments prove that the center frequency of all the filters can be accurately specified at arbitrary position by adjusting frequency parameters m and λ.

Fast and scalable routing protocols for data center networks

Data center networks may comprise tens or hundreds of thousands of nodes,and,naturally,suffer from frequent software and hardware failures as well as link congestions.Packets are routed along the shortest paths with sufficient resources to facilitate efficient network utilization and minimize delays.In such dynamic networks,links frequently fail or get congested,making the recalculation of the shortest paths a computationally intensive problem.Various routing protocols were proposed to overcome this problem by focusing on network utilization rather than speed.Surprisingly,the design of fast shortest-path algorithms for data centers was largely neglected,though they are universal components of routing protocols.Moreover,parallelization techniques were mostly deployed for random network topologies,and not for regular topologies that are often found in data centers.The aim of this paper is to improve scalability and reduce the time required for the shortest-path calculation in data center networks by parallelization on general-purpose hardware.We propose a novel algorithm that parallelizes edge relaxations as a faster and more scalable solution for popular data center topologies.

Hybrid Multi-Object Optimization Method for Tapping Center Machines

This paper proposes a hybrid multi-object optimization method integrating a uniform design,an adaptive network-based fuzzy inference system(ANFIS),and a multi-objective particle swarm optimizer(MOPSO)to optimize the rigid tapping parameters and minimize the synchronization errors and cycle times of computer numerical control(CNC)machines.First,rigid tapping parameters and uniform(including 41-level and 19-level)layouts were adopted to collect representative data for modeling.Next,ANFIS was used to build the model for the collected 41-level and 19-level uniform layout experiment data.In tapping center machines,the synchronization errors and cycle times are important consid-erations,so these two objects were used to build the ANFIS models.Then,a MOPSO algorithm was used to search for the optimal parameter combinations for the two ANFIS models simultaneously.The experimental results showed that the proposed method obtains suitable parameter values and optimal parameter combinations compared with the nonsystematic method.Additionally,the optimal parameter combination was used to optimize existing CNC tools during the commissioning process.Adjusting the proportional and integral gains of the spindle could improve resistance to deformation during rigid tapping.The posi-tion gain and prefeedback coefficient can reduce the synchronization errors significantly,and the acceleration and deceleration times of the spindle affect both the machining time and synchronization errors.The proposed method can quickly and accurately minimize synchronization errors from 107 to 19.5 pulses as well as the processing time from 3,600 to 3,248 ms;it can also shorten the machining time significantly and reduce simultaneous errors to improve tapping yield,there-by helping factories achieve carbon reduction.

Exploiting User Centered Design Approach and Interactivity in Web Based Software Developing

Human computer interaction (HCI) and software engineering approaches are always taken into the account together in order to make the well-organized software. Interactive design is the significant part of new media which has been proposed to the world for the past decades, and it is a very proficient technique. Interactive maps add more dimensions of information;they become a more and more helpful tools and resources. This research clarifies the idea of how we can smooth the progress of presenting and communicating the essential information using interactive manner. The interactive map of Bangkok underground train and sky train navigation routes map was developed as the case study using user-centered design (UCD) methodology as the fundamental developing processes. The main objective of the work is to develop the friendly and usable web based software that reduce the confusion and help users save times. The software developing processes in this work tend to focus on the users. And also the essential idea of the research is to take the uses and gratification communication theory of the users into account with the intention of providing what user requires by finding the real users’ requirements. This means the user can control software according to their needs and software act or response according to user’s requests. The paper mentions the role of communication theory, human computer interaction, and user-centered design software developing.

基于对分课堂理念的蔬菜嫁接实验课堂教学改革

“以学生为中心”的对分课堂教学模式是一种新型教学模式,突出强调内化吸收和讨论环节。传统的蔬菜嫁接实验课堂教学模式不能充分调动学生课堂参与的积极性和主动性,也不能提升学生的创新能力。基于学生主体性与潜能发挥,结合蔬菜嫁接实验本身,提出了“以学生为中心”的蔬菜嫁接实验对分课堂教学模式,对教学内容进行了层次化设计,增加了实验的综合性和创新性。实验过程增加了实验设计、小组讨论和答辩环节,建立了实验全过程的考核体系。教学实践证明,“以学生为中心”的蔬菜嫁接实验对分课堂教学模式激发和培养了学生的实践和创新能力,有效提高了实验教学效果。

利益群体视角下江西省国家区域医疗中心建设探讨

建设国家区域医疗中心是促进优质医疗资源均衡布局的重大举措。江西省国家区域医疗中心建设数量多,且病种选择准、会商调度勤、思想统一快。但从政府、输出医院、依托医院等利益群体视角看,仍存在顶层设计不清晰、参与医院动力不足等问题,需要加快健全协调机制、明晰三方权责、完善考评和专班制度、优化绿色通道,强化输出医院动力,支持依托医院错位发展,打造可持续的双方合作与项目医院自我发展模式。

基于胆碱类低共熔溶剂高效提取香附总黄酮的研究

目的:采用胆碱类低共熔溶剂高效提取香附药效组分总黄酮。方法:通过中心组合设计法,对胆碱类低共熔溶剂的性质(种类、组分摩尔比、含水量)、提取温度、提取时间、液料比等因素进行分析。结果:研究发现,香附总黄酮的最佳提取条件为:以氯化胆碱为氢键供体,以丙三醇为氢键受体,摩尔比1∶2,含水量20%,配比1∶4,水比例30%,提取温度80℃,提取时间40 min,液固比为15 mL/g。结论:本研究提示可将胆碱类低共熔溶剂作为可持续、高效的天然提取介质应用于香附药效组分的提取。

学习中心视角下的大单元教学设计

大单元作为学习单位的本质规定,意味着大单元教学的重心不是教授内容而是组织和引导学习,也决定了其教学设计必须以学习为中心。学习中心视角下,大单元教学设计在任务设定、内容生成和时间安排方面分别遵循依学施教、因学而成和以学定时的理念。其内在逻辑表现为,以大观念为内核生成大单元,以大任务为起点驱动大单元,以大活动为过程展开大单元。大单元教学要在素养目标与现实材料的双向比对中提取大观念,在理论学习与经验学习的双层考量中构建大任务,在素养针对性与学科典型性的双重观照中设计大活动。其过程设计可按进阶式学习、平行式学习、迭代式学习等模式展开。

以女性为中心的智能产品设计研究

强调在智能产品设计领域应挖掘女性文化价值。围绕女性设计与人本智能产品发展现状,探究新视角下女性智能产品设计前景。采用案例分析法、文献调查法、跨学科研究法等研究方法,分析不同女性社会性别角色在产品设计中的现状。归纳以女性为中心的产品设计层次:“为女性设计”“由女性设计”和“因女性设计”。总结主要流程的设计方法,并结合智能美妆冰箱设计实践案例验证相关设计方法。为女性智能产品设计研究提供一定参考。

木窗双端铣削加工中心关键机构的设计与研究

针对被动式欧式木窗外框铣削加工效率低、加工精度低和人工劳动强度大等问题,设计一种被动式欧式木窗的双端铣削加工中心,用于被动式欧式木窗外框高效率、高精度铣削加工。通过对木窗铣削工艺的分析,采用计算机辅助设计方法对加工中心结构进行详细设计,利用Solidworks软件对加工中心进行三维建模,基于有限元分析软件对关键支撑零件的强度、刚度进行分析,使用虚拟试验方法验证加工中心的加工效率。研究结果表明,加工中心理论加工效率约为400扇/d,相较于人工加工效率350扇/d,效率提升了14.28%,关键支撑零件的最大应力远小于材料的许用应力,满足使用要求。

变滞回性能阻尼器的抗震性能及其在RC排架墩中的应用

为了实现分级保护主体结构同时减小传统耗能阻尼器在强震作用下的残余变形的目的,提出一种基于形状记忆合金(shape memory alloy,SMA)板环的新型变滞回性能阻尼器(variable hysteresis performance damper based on shape memory alloy,SMA-VHD)。首先阐明了新型阻尼器的基本构造,揭示了其变滞回性能工作机理和自复位原理。通过对SMA板材进行材性试验确定了SMA板材的关键性能参数,进而建立阻尼器精细化有限元模型,系统研究阻尼器的滞回性能及参数影响规律。最后将新型阻尼器应用于RC排架墩中,通过动力时程分析研究附加阻尼器桥墩结构的分阶段抗震性能。研究结果表明:SMA板材应力应变关系呈“旗帜型”,具有良好的自复位能力;SMA-VHD滞回曲线呈现明显分级平台,随着阻尼器变形的增加,其滞回曲线由饱满的矩形变为具有自复位功能的“旗帜型”,表明该阻尼器具有变滞回性能的特性;将SMA-VHD应用到RC排架墩中,可有效实现结构的分级抗震,提高桥墩结构的抗震性能水平。