Design approaches for active,semi-active and passive control systems based on analysis of characteristics of active control force

In this paper, the characteristics of forces in active control systems connected to adjacent levels of a building are analyzed. The following characteristics are observed： （1） active control can provide significantly superior supplemental damping to a building, but causes a small frequency shift; （2） the linear quadratic regulator （LQR）-based control force is composed of an elastic restoring force component and a damping force component, where the damping force is almost identical to the total control force, however, the elastic restoring force is very small; and （3） the active control forces prevent mction most of the time during the entire control process. These three characteristics imply that active control systems connected to adjacent levels of a building behave like passive damping devices with adjustable parameters, namely damping characteristics in an active control, which is the mechanism used by semi-active control devices to reach similar performance as active control systems. Two indices are defined to quantify the damping characteristics of control forces in active control systems. These two indices can also be used to quantify the capacity of semi-active control to achieve the perfonrlance of active control. Based on the above observations, two principles are founded for optimization of parameters of semi-active control devices and passive dampers. The first is that the maximum output force of a semi-active or passive device to be designed is identical to an active device, called ＂design principle＂. The other is the response equivalent principle, which states that the response of a building with semi-active or passive devices is the same as with active devices when the same maximum output force is applied. The design procedure for semi-active control devices and passive dampers is described in detail. Finally, numerical simulations of two benchmark problems is conducted to demonstrate the damping characteristics of active control and investigate the capacity of semi-active control to achieve the same performance as active control.

Development and in-vitro evaluation of an optimized carvedilol transdermal therapeutic system using experimental design approach

The effect of formulation variables on in-vitro release and permeation properties of carvedilol from transdermal patch was studied by varying one factor at a time as preliminary study.Based on these results,design of experiments technique was applied followed by regression analysis and response surface methodology to optimize formulation variables.Central Composite IV model design was used with four formulation variables:drug loading,matrix thickness,adhesive layer thickness,and propylene glycol concentration.Nineteen formulations were prepared according to the design;and the effect of formulation variables was studied on in-vitro release and permeation profiles of these formulations.In all cases,the permeation profiles paralleled in-vitro release profiles.The drug released at 7 h and 24 h was used as release response parameters while permeation flux obtained was employed as permeation response parameter.All four formulation variables were found to be significant for release properties and three of these exhibited significant effect on permeation profile of carvedilol across artificial membrane.Constrained optimization,using 47.9%of cumulative carvedilol released at 7 h and 99.8%at 24 h as well as 25.7 mg/cm2/h of permeation flux,was applied to obtain desired release and permeation profiles.Experimentally,carvedilol was observed to release from the optimized formulation with 51.4%drug release at 7 h and 98.5%at 24 h with an observed flux value of 27.4 mg/cm2/h across artificial membrane,which showed an excellent agreement with the predicted values.The results of this investigation show that the quadratic mathematical model developed could be used to further predict formulations with desirable release and permeation properties.

Generalized Odd-Even Mode Theory and Mode Synthesis Antenna Design Approach

In this article,studies on the multimode excitation problem of waveguides and antennas,the balance/unbalance mech-anism and the balanced feeding techniques in dipole antenna systems are first briefly historically reviewed.In this context,general-ized odd-even mode theory is advanced to quantitatively and approximately describe the mutual coupling effect between a feed line and an antenna.As is mathematically deduced and demonstrated,the modal parity mismatch between the feed line and the antenna should ultimately dominate the unbalance phenomenon in antenna systems.Thus,an elegant,closed-form formula is derived to ap-proximately calculate the“unbalance degree”of a straight dipole off-center fed by a symmetric twin-wire line.Design approaches for the simplest,linear,1-D multimode resonant antennas are introduced.Moreover,the“falling tone excitation”law gauged based on prototype dipoles is revealed and used to develop a mode synthesis design approach for microstrip patch antennas(MPAs)and 2-D sectorial electric dipole antennas.Design examples with distinctive radiation performance are presented and discussed.Finally,possible development trends of multimode resonant antennas are prospected.

Optimizing PID controller parameters for robust automatic voltage regulator system through indirect design approach-2

Automatic voltage regulators(AVR)are designed to manipulate a synchronous generator’s voltage level automatically.Proportional integral derivative(PID)controllers are typically used in AVR systems to regulate voltage.Although advanced PID tuning methods have been proposed,the actual voltage response differs from the theoretical predictions due to modeling errors and system uncertainties.This requires continuous fine tuning of the PID parameters.However,manual adjustment of these parameters can compromise the stability and robustness of the AVR system.This study focuses on the online self-tuning of PID controllers called indirect design approach-2(IDA-2)in AVR systems while preserving robustness.In particular,we indirectly tune the PID controller by shifting the frequency response.The new PID parameters depend on the frequency-shifting constant and the previously optimized PID parameters.Adjusting the frequency-shifting constant modifies all the PID parameters simultaneously,thereby improving the control performance and robustness.We evaluate the robustness of the proposed online PID tuning method by comparing the gain margins(GMs)and phase margins(PMs)with previously optimized PID parameters during parameter uncertainties.The proposed method is further evaluated in terms of disturbance rejection,measurement noise,and frequency response analysis during parameter uncertainty calculations against existing methods.Simulations show that the proposed method significantly improves the robustness of the controller in the AVR system.In summary,online self-tuning enables automated PID parameter adjustment in an AVR system,while maintaining stability and robustness.

Assessing the Applicability of Three Approaches to Design-Oriented Research

The three main approaches in inquisitive research design are qualitative,quantitative,and mixed methods[1].However,recent developments in the research field have resulted in multiple other approaches,borrowing ideas from a broad range of fields.One such approach is the practice-led approach.This approach involves an efficient design process,novel qualitative interviewing methods,together with data mining procedures from quantitative data collection[2].This paper assesses the practice-led approach used in user experience(UX)design,together with three approaches:co-design,service design,and reflective practice.

Fault reconstruction observer design for continuous-time systems with measurement disturbances via descriptor system approach

This paper addresses a problem of observer-based sensor fault reconstruction for continuous-time systems subject to sensor faults and measurement disturbances via a descriptor system approach. An augmented descriptor plant is first formulated, by assembling measurement disturbances and sensor faults into an auxiliary state vector. Then a novel descriptor state observer for the augmented plant is constructed such that simultaneous reconstruction of original system states, sensor faults and measurement disturbances are obtained readily. Sufficient conditions for the existence of the proposed observer are explicitly provided, and the application scope of the observer is further discussed. In addition, an extension of the proposed linear approach to a class of nonlinear systems with Lipschitz constraints is investigated. Finally, two numerical examples are simulated to illustrate the effectiveness of the proposed fault-reconstructing approaches.

A Trace-state Based Approach to Specification and Design of Parallel Programs

In this paper they deal with the issue of specification and design of parallel communicatingprocesses. A trace-state based model is introduced to describe the behaviour of concurrent programs. They presenta formal system based on that model to achieve hierarchical and modular development and verification methods. Anumber of refinement rules are used to decompose the specification into smaller ones and calculate program fromthe

莫高窟壁画文创产品转喻设计方法研究

立足当下国内各区域文旅发展需求,构建文创产品转喻设计创新方法,促进多样化设计方案生成,并满足消费者对文创产品的深度文化体验和情感共鸣需求。通过内涵外延传承说的类层级结构的建立,挖掘、构建文化目的域内涵项与外延项两者间的传承关系;通过转喻映射三层级的建立,得出产品源域的多个映射结果,最终产生多样化的设计方案,并应用于莫高窟文创产品设计实践中。在转喻认知相邻逻辑视角下建立的“用户”“文化”“文创产品”多路径认知关联,为用户深度认知莫高窟文化提供了新的思路与方法。

Product Family Design Methodology Using Object-Oriented Approach

The serious competition environment of global marke t requests the enterprise to change traditional product development strategy and a dopt new theory in order to meet diverse customer needs while maintaining near m ass production efficiency, which is the main philosophy of mass customization. P roduct family design is research focus at present and also is the core technolog y of DFMC (design for mass customization). Firstly, this paper explores the fund amental issues of product family, such as concepts of modularity, commonality/di versity, product platform and product family architecture etc. We compare the te rminology between product family and object-oriented approach in the next step. Thirdly, this paper puts forwards one product family design methodology based o n product platform and under different phase of product life cycle constrains, f or example, functional, assembly and service etc. At the end section of this pap er, we applied, the object-oriented approach in above mentioned product family design methodology to realize the design process. In one word, this paper propos ed one product family design methodology based on object oriented approach and p roduct life cycle consideration, especially the conjointness of characteristic o f OOA and concepts of product family. The main property of OOA are encapsulation , inherence and polymorphism. Encapsulation can represent the module or building blocks of product family. Inherence can be extended to describe the modularity and commonality, and also be used to construct variant space. Alternative specif ic of product family architecture can be embodied with polymorphism. And fin aly, we give the future work contents. In order to derive the product platform a nd achieve modularity and commonality/diversity, interface management between bu ilding block is necessary. The question is how the OOA can be applied in interfa ce management to get our aim OOA is the basis of many information management sy stem, then the question is how to build one system to manage the information of product family and support mass customization The third question is how to deve lop one computer aided tool to facilitate the application of OOA for product fam ily design, even be used to category of design for mass customization.

Application of the Robust Approach and Finite Element Analysis in Door System Static Design

The robust design approach based on Taguchi＇s design of experiment （DOE） coupled with the traditional finite element analysis （FEA） is applied to the static design of a sedan door. This method aims at shortening the design period, reducing the calculation cost and improving the competitive competence. First, the pe^ormance re- quirements, the control factors and the corresponding levels are determined to design a DOE table. Second, based on the schemes from the DOE table, sensitive control factors are distinguished from the results of the FEA method. Finally, the optimum design is chosen after comparisons and analyses of these performance response graphs. Performance results of the optimum design indicate that the application of the robust approach and FEA can greatly im- prove the quality of the door system, satisfy the requirements of products, underline the design purpose and shorten the design period.

Airfoil design optimization based on lattice Boltzmann method and adjoint approach

We present a new aerodynamic design method based on the lattice Boltzmann method （LBM） and the adjoint approach. The flow field and the adjoint equation are numerically simulated by the GILBM （generalized form of interpolation supplemented LBM） on non-uniform meshes. The first-order approximation for the equilibrium dis- tribution function on the boundary is proposed to diminish the singularity of boundary conditions. Further, a new treatment of the solid boundary in the LBM is described par- ticularly for the airfoil optimization design problem. For a given objective function, the adjoint equation and its boundary conditions are derived analytically. The feasibility and accuracy of the new approach have been perfectly validated by the design optimization of NACA0012 airfoil.

An Innovative Soft Design Science Methodology for Improving Development of a Secure Information System in Tanzania Using Multi-Layered Approach

This paper presents an innovative Soft Design Science Methodology for improving information systems security using multi-layered security approach. The study applied Soft Design Science Methodology to address the problematic situation on how information systems security can be improved. In addition, Soft Design Science Methodology was compounded with mixed research methodology. This holistic approach helped for research methodology triangulation. The study assessed security requirements and developed a framework for improving information systems security. The study carried out maturity level assessment to determine security status quo in the education sector in Tanzania. The study identified security requirements gap (IT security controls, IT security measures) using ISO/IEC 21827: Systems Security Engineering-Capability Maturity Model (SSE-CMM) with a rating scale of 0 - 5. The results of this study show that maturity level across security domain is 0.44 out of 5. The finding shows that the implementation of IT security controls and security measures for ensuring security goals are lacking or conducted in ad-hoc. Thus, for improving the security of information systems, organisations should implement security controls and security measures in each security domain (multi-layer security). This research provides a framework for enhancing information systems security during capturing, processing, storage and transmission of information. This research has several practical contributions. Firstly, it contributes to the body of knowledge of information systems security by providing a set of security requirements for ensuring information systems security. Secondly, it contributes empirical evidence on how information systems security can be improved. Thirdly, it contributes on the applicability of Soft Design Science Methodology on addressing the problematic situation in information systems security. The research findings can be used by decision makers and lawmakers to improve existing cyber security laws, and enact laws for data privacy and sharing of open data.

用户需求视角下湘西竹编纹样在家具设计中的应用

为探索湘西竹编纹样在家具设计中的传承应用,使其满足当代用户的需求,以圈椅为例进行剖析。首先通过调研和搜集资料构建圈椅样本库及湘西竹编元素库;其次通过问卷调查、文献检索和目标用户访谈法获取用户需求,利用熵权TOPSIS模型对用户需求进行整合,AHP计算用户需求的权重,以此为依据从圈椅样本库和湘西竹编元素库中确定初始形状;并通过形状文法的造型推演规则对各设计要素进行草图方案推演;最后基于灰色关联分析法得到方案评判关联度,确定最佳方案。结果表明,通过设计实践验证了使用AHP-熵权TOPSIS得到的用户需求较为准确,用形状文法将湘西竹编纹样运用在家具设计中的可行性。该设计方法的运用使竹编文化在家具设计中得到传承的同时,也能满足用户的需求,既提升了家具产品的文化内涵与美学价值,也为“以竹代塑”在家具行业的推行提供借鉴。

一体多面,思政育人——基于OBE教育理念的“高级英语”教学改革

“高级英语”是英语专业高年级学生的专业必修课,在人才培养中具有极为重要的地位和作用。新文科建设背景下,课题组积极探索改革与创新途径,对该课程进行了系统、全面的教学改革,坚持“思政引领、协同育人”的教学目标,采用OBE教育理念对课程教学进行反向设计,打造“课上课下+线上线下”的混合式课堂,构建一体多面的课程质量评价体系。

渐进式项目驱动法在网页设计课程教学中的应用

渐进式项目驱动法是在项目驱动法的基础上发展而来的,强调项目的选取和拆分,通过由小到大、由简单到复杂的项目整合多个知识点,让学生循序渐进地掌握所有知识。文中将项目渐进驱动法融入到《网页设计与制作》课程中,介绍了课程教学的现状、教学设计、教学实施以及教学效果,以期帮助学生快速掌握网页前端设计的技术,促进他们知识体系的构建。

产出导向法视阈下中医英语教材的设计与编写——以《中医文化交流英语》为例

《中医文化交流英语》是我国第一部以中医文化交流为主题设计、编写的中医英语教材。文章基于产出导向法,论述了该教材的设计思路和编写特色,具体讨论了如何将产出导向法的“学用一体”“学习中心说”和“文化交流说”应用于中医文化类教材,以及如何在“驱动-促成-评价”的教学流程指导下设计和构建单元的小循环和中循环,并从内容安排、材料选择、练习设计和教学目标角度讨论了该教材的编写特色。文章特别提出了在中医文化英语教学中,应培养学生“言之有物+结构合理+用词准确”的新三合一话语能力、跨文化交际能力和文化思辨能力的教学目标。

Design of Pastoral Cultural Landscape Oriented by the Concept of Ecology Villages

China is increasingly attaching importance to coordination and scientific development between humanist and economic constructions, especially for protection on rural pastoral cultural landscape. For eco-village theory, planning and construction of pastoral culture landscape is just a breakthrough. The research used modern landscaping technology and analyzed pastoral landscape culture, facilitating transformation of agricultural production pattern and ushering in a new trend in terms of retaining rural cultural landscapes with Chinese characteristics and inheriting and innovating rural culture.