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A simple algebraic test applied to a specially constructed constant matrix is developed to test the semi‐definiteness property of symmetric functional matrices. The simplicity of the algebraic test makes it very suitable for computer implementation. The results are applied in the analysis of a class of nonlinear time‐varying singular RC networks. Robustness of the boundedness property of network response with respect to resistive elements is shown.

The purpose of this paper is to investigate whether age plays a role in the acquisition of construct state (CS) constructions in Arabic by 14 children with autism spectrum disorder (ASD). It also examined the challenges faced by children with ASD in producing different types of CS constructions. Finally, the study analysed the sources of difficulties children with ASD encounter during the learning process of the CS.

For the purposes of this study, the participants were asked to orally complete short sentences with the help of illustrative pictures.

Results revealed that the age of the 14 children with ASD plays a role in the acquisition of CS constructions. Children of age 12–15 performed better than those of age 8 and 10. Results also showed that children with ASD performed better in producing phrases rather than compounds. Moreover, the participants performed better on endocentric compounds as opposed to exocentric ones. Finally, analysing the errors produced on the text revealed that the acquisition of head direction precedes definiteness.

The topic of the study has not been investigated yet and the study concluded with some important findings concerning teaching Arabic CS to children with ADS.

In this study, we analyze the power of the individual return-to-volatility security performance heuristic (ri/stdi) to simplify the identification of securities to buy and, consequently, to form the optimal no short sales mean–variance portfolios. The heuristic ri/stdi is powerful enough to identify the long and shorts sets. This is due to the positive definiteness of the variance–covariance matrix – the key is to use the heuristic sequentially. At the investor level, the heuristic helps investors to decide what securities to consider first. At the portfolio level, the heuristic may help us find out whether it is a good idea to invest in equity to begin with. Our research may also help to integrate individual security analysis into portfolio optimization through improved security rankings.

This chapter compares the performance of the maximum simulated likelihood (MSL) approach with the composite marginal likelihood (CML) approach in multivariate ordered-response situations. The ability of the two approaches to recover model parameters in simulated data sets is examined, as is the efficiency of estimated parameters and computational cost. Overall, the simulation results demonstrate the ability of the CML approach to recover the parameters very well in a 5–6 dimensional ordered-response choice model context. In addition, the CML recovers parameters as well as the MSL estimation approach in the simulation contexts used in this study, while also doing so at a substantially reduced computational cost. Further, any reduction in the efficiency of the CML approach relative to the MSL approach is in the range of nonexistent to small. When taken together with its conceptual and implementation simplicity, the CML approach appears to be a promising approach for the estimation of not only the multivariate ordered-response model considered here, but also for other analytically intractable econometric models.

This article aims to present a direct solution to handle linear constraints in finite element (FE) analysis without penalties or the Lagrange multipliers introduced.

First, the system of linear equations corresponding to the linear constraints is solved for the leading variables in terms of the free variables and the constants. Then, the reduced system of equilibrium equations with respect to the free variables is derived from the finite-dimensional virtual work equation. Finally, the algorithm is designed.

The proposed procedure is promising in three typical cases: (1) to enforce displacement constraints in any direction; (2) to implement local refinements by allowing hanging nodes from element subdivision and (3) to treat non-matching grids of distinct parts of the problem domain. The procedure is general and suitable for 3D non-linear analyses.

The algorithm is fitted only to the Galerkin-based numerical methods.

The proposed procedure does not need Lagrange multipliers or penalties. The tangential stiffness matrix of the reduced system of equilibrium equations reserves positive definiteness and symmetry. Besides, many contemporary Galerkin-based numerical methods need to tackle the enforcement of the essential conditions, whose weak forms reduce to linear constraints. As a result, the proposed procedure is quite promising.

In order to make the aperture of spatial deployable antenna larger, this paper proposed the study on a spatial annular tensegrity structure with 100 m large scale, which could be one of the ideal solutions to improve the dimension of the antenna. This study is aiming to figure out the dynamic characteristic of ultra-large annular tensegrity and address the problem of insufficient rigidity with local modes that many ring truss-type deployable antenna structures have faced.

This work is carried out based on the nonlinear dynamic modelling when fully considering the effect of bending and torsion deformation of beams, as well as the pretension of cables. Additionally, the structural stability analysis based on the proposed stability criterion is also presented to evaluate the tensegrity configuration with different distribution of cable groups.

This research results verify that the modified structure with radial ribs could eliminate the effect of the local vibration mode on stiffness and is suitable to meet the requirements of the annular tensegrity structure. Additionally, the calculation results demonstrate that the structural configuration of annular tensegrity with 36 groups of cables which share the nodes with radial ribs is more appropriate to enhance the stiffness and structural stability.

A new large annular tensegrity structure with radial ribs and tensioned cables is proposed. Based on the proposed structural configuration, the positive definiteness of the tangent stiffness matrix is carried out as the criterion of stability and the composition of the analytical expression of the tangent stiffness matrix is analyzed. Four levels of tensegrity structure stability have been carried out and the influence of the structural parameters on the stability and the rigidity has been analyzed. A scaled-down prototype is developed to verify the feasibility of the design of the hoop-column-rib configuration by the deployment and dynamic experiment.

‘A peculiarity of the study of (Information Science) is its lack of demarcations: sooner or later the student of (Information Science) finds himself wandering into fields that are occupied by other sciences. The practical difficulty of drawing a dividing‐line between the legitimate scope of (Information Science) and that of other studies is so great that we are often told there is no science of (Information). This lack of definiteness adds a charm to the subject and is fertile in the production of new idea, for it is at the fringe of a science that originality has its scope.’

Sufficient conditions for bounded input‐bounded output (BIBO) stability are established for a class of time‐variable linear semi‐state systems. These conditions are expressed directly in terms of system parameters and reduce to testing of negative semi‐definiteness of a time‐varying matrix. Simple algebraic conditions convenient for the computer applications are derived for this purpose. It is shown how the results obtained can be applied in the analysis of linear time‐variable RLC electrical networks.

The purpose of this paper is to explore the role and viability of changing contract terms as a project progresses and to offer an original analysis in this respect. Commonly, projects start out with broadly defined information, and this gets refined as the project progresses. This suggests that a prudent approach would be to tailor the contract between the project owner and the project contractor to the project stage, with conversions along the way. Information asymmetry between owner and contractor also suggests the need to tailor a contract to a project ' s situation.

An original method of analysis of the conversion of contract terms within projects is given, along with discussion on the risk transfer between owner and contractor, the common law issues associated with implementing such conversions, any compensation that the owner might need to pay, the timing of the conversion and associated practical implementation issues. The paper, for definiteness, concentrates on construction contracts with conversion between payment types, but the paper’s approach applies to all contracts and all terms within contracts.

The paper provides a readily usable method for analysing the value of having a convertible contract, couched within acceptable common law practice.

The paper offers a novel method and framework usable by practitioners for establishing the value of convertibility within a contract. Having convertibility within a contract can be shown to offer benefits to both contracting parties.

The idea of having flexible contracts is not new, but, hitherto, a rational method of analysing their value has been missing. This paper gives an original analysis of contracts with conversion capabilities. Current literature does not deal directly with the matter addressed in the paper.