A prototype approach to information system design and development

Many organisations view the development of an information processing system as a linear process consisting of an ordered sequence of steps from conception to hand-over and make no provision for alternative strategies. While excellent in many circumstances, the linear strategy is not the only possible approach. This paper discusses alternatives, with particular reference to a prototype strategy, which has some important advantages.     

A decoupled approach to filter design for stochastic systems

This paper presents a new theorem to guarantee the almost sure exponential stability for a class of stochastic triangular systems by studying only the stability of each diagonal subsystems. This result allows to solve the filtering problem of the stochastic systems with multiplicative noises by using the almost sure exponential stability concept. Two kinds of observers are treated: the full-order and reduced-order cases.     

FBMC系统中原型滤波器的迭代设计算法

基于滤波器组的多载波系统的整体性能完全由一个原型滤波器决定,例如频率选择特性、符号间干扰和信道间干扰。为构建近似完全重构的多载波系统,提出了一种迭代算法来设计原型滤波器。该算法将设计问题归结为一个无约束的优化问题,其目标函数为符号间干扰、信道间干扰以及原型滤波器阻带能量的加权和。通过推导目标函数的梯度向量和海森矩阵,采用修正牛顿算法来迭代优化原型滤波器,每次迭代更新中,原型滤波器都是通过闭合公式求解,因此算法的计算复杂度很低。仿真实验表明,与已有的设计算法相比,所提出的算法提高了系统的整体性能。     

The combinatorial design approach to automatic test generation

The combinatorial design method substantially reduces testing costs. The authors describe an application in which the method reduced test plan development from one month to less than a week. In several experiments, the method demonstrated good code coverage and fault detection ability     

A new approach to design triplet halfband filter banks based on balanced-uncertainty optimization

This paper presents a novel approach to design a class of triplet halfband filter banks (THFB) based on optimized time–frequency localization. First, an Euler–Frobenius polynomial (EFP) is introduced to design a class of halfband polynomial. The vanishing moments and perfect reconstruction conditions are imposed on EFP to obtain maximally flat halfband filter. The resultant halfband filter is optimized using a balanced-uncertainty (BU) metric in order to have balance between time and frequency spread. Next, this optimized halfband filter is used in three-step lifting scheme to obtain analysis and synthesis wavelet filters which have balance between time and frequency localization. The proposed method provides three degrees of freedom that results in flexible design of filter bank. It is observed that the proposed filter bank gives more regularity and better frequency selectivity as compared to existing filter banks. These designed filters are then used for human chromosome image compression application. The performance of the designed filter bank is compared in terms of PSNR using different bit-rates with well-known existing filter banks in order to validate the experimental results.     

A local approach to concept generation

Generating concepts defined by a binary relation between a set of properties and a set of objects is one of the important current problems encountered in Data Mining and Knowledge Discovery in Databases. We present a new algorithmic process which computes all the concepts, without requiring an exponential-size data structure, and with a good worst-time complexity analysis, which makes it competitive with the best existing algorithms for this problem. Our algorithm can be used to compute the edges of the lattice as well at no extra cost.      

新的基于LMI的鲁棒故障检测滤波器设计方法*

提出一种新的基于LMI的滤波器设计方法,能够解决在线性时不变系统中进行故障检测时所遇到的多目标优化问题。通常在故障检测中,H∞范数用于描述残差对于外界干扰的鲁棒性,而H指标用于描述残差对于故障的灵敏度。通过引入残差的误差值,将多个指标（H∞和H指标）统一转换成H∞范数,从而将故障检测滤波器的设计问题转换成对H∞范数优化问题;然后用一种新颖的基于LMI的方法来求解;最后,将本算法应用于某导弹发生故障的纵向平面模型,仿真结果表明了该算法能有效、及时地检测出故障。     

A knowledge-based approach to design

A framework is presented for constructing knowledge-based aids for design problems. In particular, we describe the organization of an interactive knowledge-based consultant for VLSI design (called VEXED?an acronym for VLSI expert editor), and a prototype implementation of VEXED. The paper focuses on the principles underlying the design of VEXED, and on several lessons and research issues that have arisen from implementing and experimenting with this prototype.     

A geometric approach to boundary-conformed toolpath generation

Isoparametric or streamline-like toolpath generation is an important method for CNC surface machining. For a trimmed surface, the generation of such a toolpath is not straightforward because by simply following the isoparametric curves of the parametric surface to generate the toolpath, the resulting toolpath may no longer conform to the trimmed boundary of the surface. Various methods have been proposed to solve this problem. Some methods work well for single surface machining, but may not be feasible for multi-patch surface machining. A new geometric approach to the problem of multi-patch machining is proposed in this paper. The new method works by generating bisectors to partition the region into smaller subregions, and generates the toolpath by offsetting the subregion boundary by using a special offset function. As this new method does not rely on processing on the parametric domain of the surface patches, it can be used for both NURBS and subdivision surfaces. Examples are given to demonstrate the capability of the new method, and to show that the new method compares favorably with existing techniques.     

A parameter-varying fault detection filter design approach for polytopic uncertain linear systems

This paper is concerned with the robust fault detection (FD) problem for a class of polytopic uncertain linear systems driven by a Wiener process. It is assumed that the state matrix is affinely depending on unknown but bounded time-varying parameters. A switching mechanism is introduced to construct the robust FD filter with variable gains and to improve the FD performances which are inherent in the traditional FD filter with fixed gains. Finally, the filter design problem is formulated as a feasibility problem in terms of solving linear matrix inequalities (LMIs), and an example is presented to illustrate the proposed methodology.     

A novel prototype generation technique for handwriting digit recognition

The aim of this paper is to introduce a novel prototype generation technique for handwriting digit recognition. Prototype generation is approached as a two-stage process. The first stage uses an Adaptive Resonance Theory 1 (ART1) based algorithm to select an effective initial solution, while the second one executes a fine tuning designed to generate the best prototypes.     

A formal approach to automating conceptual structural design,part II: Application to floor framing generation

The function of the structural system in a building is to transfer gravity as well as lateral loads from their points of origin to the ground. Floor framing generation involves providing a path to transfer the gravity loads to the ground through various structural elements in an architectural plan while meeting the requirements imposed by other entities, such as the architect, the mechanical engineer, and the contractor, involved in the design/construct process. In this paper a formal approach for generating floor framing plans for steel office buildings is presented. We describe the knowledge and the reasoning behind a computer system, FFG (floor framing generator), which generates floor framing schemes for steel office buildings that are rectangular in plan and have a single service core. Constraints arising from structural as well as exogenous considerations are enumerated and their effect on framing schemes is identified. We also elaborate on the evaluation mechanism for ranking alternative schemes, in addition to providing details of the computer implementation.     

A multi-agent approach to fixture design

The design of fixtures is a highly complex process that requires the human designer to draw from his rich experience. In addition, for a given workpiece, multiple solutions may exist. By exploiting the recent advances in CAD/CAM and Artificial Intelligence techniques, one may constrain the multiple solutions such that only good designs (measured through performance measures) are considered.In this paper, a multi-agent fixture design system is proposed that harnesses the advantages of genetic algorithms and neural networks. This system attempts to capture the relevant domain knowledge and uses it to produce acceptable solutions efficiently. The system is applied to a case problem and the suggested fixturing solution is compared to one offered by a human designer. The agreement between the two solutions is very close.     

A structured approach to language design

This report is an attempt at systematizing a set of ground rules for high-level language design. It recommends the use of a hierarchical semantic model schema. HGL, in a step by step, top-down approach imposing more and more structure on the language components as the design becomes solidified. The approach is demonstrated by showing the stepwise design of the high-level language, GRAAL. The method recommended is divided into three major phases. The first is an informal one. The second is encoding the language components into a very high-level model. This high-level design allows a redesign of language components before they have been specified at too detailed a level. The third phase is to design the compiler in HGL using the final language design.     

A feature-based approach to structural design

Despite the continuing improvements in computeraided design (CAD) systems and improvements in geometric modeling, most CAD systems are used as advanced drafting and drawing management tools by structural designers. A computer model of a structural design usually is generated by creating a detailed geometric model of the primitive components of the design and then attaching attributes, such as physical properties and loading conditions, to the various geometric components to reveal the structural characteristics of those components. Thisbottom-up approach has been inherited from early drafting techniques and contrasts sharply with a structural designer's natural way of thinking and reasoning about the design. Geometric features, on the other hand, provide high-level abstractions of design information and can be tailored to a designer's specific engineering needs. In this paper the advantages of using feature-based techniques in structural CAD systems are discussed. These techniques provide better modeling primitives for users and superior data models for CAD systems for reasoning about the geometry, topology, and engineering properties of a structure.     

A pattern approach to interaction design

To create successful interactive systems, user interface designers need to cooperate with developers and application domain experts in an interdisciplinary team. These groups, however, usually lack a common terminology to exchange ideas, opinions and values. This paper presents an approach that uses pattern languages to capture this knowledge in software development, human-computer interaction (HCI) and the application domain. A formal, domain-independent definition of design patterns allows for computer support without sacrificing readability, and pattern use is integrated into the usability engineering life cycle. As an example, experience from building an award-winning interactive music exhibit was turned into a pattern language, which was then used to inform follow-up projects and support HCI education.An earlier version of this paper appeared in theProceedings of the DIS 2000 International Conference on Designing Interactive Systems (16–19 August 2000, New York) and appears by permission of the ACM Press.     

A novel approach to L1 filter design for asynchronously switched positive linear systems with dwell time

In this paper, the L₁ filtering problem is studied for continuous‐time switched positive linear systems (SPLSs) with a small delay existing in the switching of the filter and the subsystem. Unlike the existing literature concerned with asynchronous problems of SPLSs, the synchronous and asynchronous filters will be designed separately, which implies less conservative results. By introducing a class of clock‐dependent Lyapunov function (CDLF), which jumps down when the modes of the filter or the subsystem change and may increase or decrease during the asynchronous interval, clock‐dependent sufficient conditions characterizing a nonweighted L₁‐gain performance of the filter error systems are established. Then, based on the L₁ analysis results, a pair of error‐bounding filters are designed to estimate the outputs of SPLSs. The filter gains can be obtained by solving a set of linear programming. Finally, two numerical examples are presented to show the effectiveness and advantages of the results.