Vibrations of multiple delaminated beams

The free vibrations of beams with two enveloping delaminations have been solved analytically without resorting to numerical approximation. The multiple delaminated beam is analyzed as several interconnected Euler–Bernoulli beams. The differential stretching and the bending–extension coupling are considered in the formulation. The influence of the sizes and locations of the delaminations on the primary and secondary frequencies and mode shapes of a beam are investigated. For clamped–clamped beams, the primary frequency shows a high sensitivity for the long delamination but a low sensitivity for the second short delamination, while for the secondary frequency, the sensitivity is high for both delaminations. For cantilever beams, the primary and secondary frequencies show a high sensitivity for the long delamination but low sensitivity for the second short delamination. Results are compared with the analytical and experimental data reported in the literature to verify the validity of the present model.     

Heart rate response to industrial work at different outdoor temperatures with or without temperature control system at the plant

Different outdoor temperatures, the association between indoor temperature control at the workplace and working heart rates of industrial employees were evaluated. The subjects, 6,016 male and female employees in 21 industrial plants in Israel, were screened for cardiovascular risk factors between 1985–87 (The CORDIS Study). The data collected included resting heart rate, working heart rate (based on one hour ambulatory ECG), outdoor temperatures, temperature control (TC) status of the plant, workload, age and health-related habits. At outdoor temperatures below or above 22–28°C, subjects working in plants with TC had lower mean working heart rate HR (- 2 bpm) than those working in plants without TC (p < 0·0004 after adjustment for confounders). No statistically significant differences in mean working HR were found between subjects working with TC (at all the outdoor temperatures) and those without TC within the outdoor temperature range 22–28°C. Based on working heart rate, indoor temperature control in industrial plants appears to moderate the cardiovascular strain in working subjects during both cold and hot days.     

Web内容过滤实现方法的研究

介绍了Web内容过滤的技术原理以及如何通过防火墙实现的方法。通过所设计的"内容过滤模型"体现出"用防火墙实现内容过 滤"的优势。该模型把URL过滤和文本关键词过滤二种技术相结合。在不降低过滤精度的基础上提高了过滤速度。还论述了对经典过滤算法 以及参数设置的改进,最后以实例介绍在防火墙上的实现方法。     

Pseudo-arithmetical operations as a basis for the general measure and integration theory

Several generalizations of the classical measure and integration theory are based on some generalizations of the standard arithmetical operations. The axiomatic approach to the pseudo-arithmetical operations of pseudo-addition and pseudo-multiplication is discussed. Some of required properties strongly influence the structure of these operations (and consequently the resulting measure and integral generalizations). So, e.g., the -idempotency of the -unit element u results to the idempotency of the pseudo-addition , i.e., =v (sup). Several other properties of and and their consequences are discussed and illustrated by examples.     

Automatic software model checking via constraint logic

This paper proposes the use of constraint logic to perform model checking of imperative, infinite-state programs. We present a semantics-preserving translation from an imperative language with recursive procedures and heap-allocated mutable data structures into constraint logic. The constraint logic formulation provides a clean way to reason about the behavior and correctness of the original program. In addition, it enables the use of existing constraint logic implementations to perform bounded software model checking, using a combination of symbolic reasoning and explicit path exploration.     

Type error slicing in implicitly typed higher-order languages

Previous methods have generally identified the location of a type error as a particular program point or the program subtree rooted at that point. We present a new approach that identifies the location of a type error as a set of program points (a slice) all of which are necessary for the type error. We identify the criteria of completeness and minimality for type error slices. We discuss the advantages of complete and minimal type error slices over previous methods of presenting type errors. We present and prove the correctness of algorithms for finding complete and minimal type error slices for implicitly typed higher-order languages like Standard ML.     

Using the fuzzy analytic hierarchy process on optimum spatial allocation

This study uses the fuzzy analytic hierarchy process (FAHP) approach on a multiple criteria decision-making process made up of rational and emotional choices. The process involves setting evaluation criteria, constructing a fuzzy judgment matrix and weight vector, and then ranking the order of candidate alternatives by a fuzzy number in the fuzzy sequencing vector. This FAHP approach can provide hotel managers with a suitable way to determine the optimum spatial allocation. Also, creation of an artificial spatial allocation image by the image compositing technique allows hotel managers to see the future completed work before renovating, and the emotional judgment of the spatial image can take place immediately. Furthermore, the virtual image facilitates the reduction of communication time between hotel managers and designers and increases the level of satisfaction towards the final spatial allocation.

Relevance to industry

The FAHP approach addressed in this study can be applied to hotels, motels and related spaces where spatial allocation is needed and helps decision-makers or designers to choose the optimum alternative under the consideration of rational and emotional factors.     

Global optimization of linear hybrid systems with explicit transitions

The global optimization of hybrid systems described by linear time-varying ordinary differential equations is examined. A method to construct convex relaxations of general, nonlinear Bolza-type objective functions or constraints subject to an embedded hybrid system with explicit transitions is presented. The optimization problem can be solved using gradient-based algorithms in a branch and bound framework that is shown to be infinitely convergent when the implied state bounds are employed.     

H2 approximation of multiple input/output delay systems

Many physical multivariable processes can be sufficiently described as linear models with multiple input/output delays. To simplify the synthesis and analysis of control problem, a reduced-complexity model is often desired. In this paper, an H₂ model reduction scheme is introduced for stable linear systems with multiple input/output delays. The reduced model can be a finite dimensional linear model, or a linear model with a time delay. In the latter case the approximation can be improved drastically without increasing the order of the finite dimensional part. The stability is preserved in the approximating models by employing a parametrization of linear stable systems. The optimal parameters can be obtained by solving an optimization problem using a gradient-based method. Two chemical numerical examples are used to show the effectiveness of the proposed scheme.     

Striving for a total integration of CAD, CAPP, CAM and CNC

Over the last 50 years, conventional programming of the numerical controlled (NC) machine tools has been based on a data model stipulated by ISO 6983, or otherwise known as G-codes. It was designed to sequentially pass instructions to the controls of machine tools with little, if any, intelligence. It has been realized that this standard has led to serious impediments for the fulfilment of total CAD/CAM integration. The forthcoming ISO 14649 defines a new interface for exchange of information between CAD/CAM systems and NC machine tools. ISO 14649 is strictly harmonized with ISO 10303 (STEP), hence the name STEP-NC meaning an extended STEP for numerical control. There has been substantial amount of research being carried out concerning STEP-NC, in particular EU and USA; its benefits and potentials are revealing and appealing. The manufacturing industry may have to embrace itself with a revolutionary change even more dramatic than that of introduction of numerical control about half a century ago.