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IN a previous article (Ref. 1) the present author outlined some fundamental considerations of general practice. In the present paper the intention is, in effect, to take some pages from a designer's notebook and explain in detail the procedure by which the dynamic characteristics of a leg are determined. A description of one of the author's own designs will provide a suitable area of reference, and although certain of the geometrical calculations will apply rather specially to this, the remainder of the working will be quite general in its application. In particular, the orifice calculations—a vitally useful aspect which has not previously been treated in a practical fashion—have been compared with drop‐test results over a range of differing designs and sizes of shock‐absorber and show very good agreement with them; certainly good enough for a close initial approximation, and in the style of leg described here and in other simple fixed orifice designs, sufficiently accurate to allow of dispensing with dynamic tests provided that tyre and oleo relationships do not diverge too far from the conventional.

The new developments in silicon Hall sensors are highlighted. First, basic components made by microelectronic technology are explained. They lead to the development of high accuracy vectorial magnetic probes. Then examples of new applications like angular position sensor and current measurements are illustrated. Finally, new concepts in order to increase the detectivity using magnetic chopping are demonstrated.

In this presentation I shall be concerned with only one aspect of information science and its relation with linguistics: namely document analysis (for a broader survey of ‘Linguistics and information science’, see the recent article published under that title by C. Montgomery (1972); also M. Kay and K. Sparck Jones (1971), and the report prepared for F.I.D. by the same authors, forthcoming; M. Coyaud (1972), in French, deals with many separate facets of the same subject).

This chapter uses data from the World Bank’s Private Participation in Infrastructure project database, and hand-collected evidence on project performance, to examine how PPPs are applied to infrastructure development in Africa, and how well they have delivered expected benefits. It has two analytical parts: an investment trend analysis and a meta-analysis of project performance and explanatory factors. The analysis shows growth both in number and volume of PPP investments that is weaker than that observed in other developing regions, and more volatile. The performance of PPP contracts appears to be improving over time with an overall cancelation rate of 7% over the assessment period. Although PPPs have contributed to increasing infrastructure stock, they have not completely met their potential, especially with respect to increasing infrastructure access rates. The main determinants of performance include accuracy of costing and allocation of risks, consistency of macro policies with the objectives and functioning of PPPs, coherence of sector policies and plans and local capacity. Contract cancellations are mainly explained by the misalignment of outcomes with government objectives, in particular, access and investment objectives. These findings suggest that PPP application should be well planned to ensure coherence of a wide range of policies, readiness of institutions and capacity of public sector actors. This chapter contributes to closing information gaps on a relatively novel policy instrument, and provides useful evidence to support prudent policy making at the time of considerable growth in PPP application.

The purpose of the method is to develop a numerical method for the solution of nonlinear partial differential equations.

A new numerical approach based on Barycentric Rational interpolation has been used to solve partial differential equations.

A numerical technique based on barycentric rational interpolation has been developed to investigate numerical simulation of the Burgers’ and Fisher’s equations. Barycentric interpolation is basically a variant of well-known Lagrange polynomial interpolation which is very fast and stable. Using semi-discretization for unknown variable and its derivatives in spatial direction by barycentric rational interpolation, we get a system of ordinary differential equations. This system of ordinary differential equation’s has been solved by applying SSP-RK43 method. To check the efficiency of the method, computed numerical results have been compared with those obtained by existing methods. Barycentric method is able to capture solution behavior at small values of kinematic viscosity for Burgers’ equation.

To the best of the authors’ knowledge, the method is developed for the first time and validity is checked by stability and error analysis.

This article follows on an investigation conducted by the Unit for Library and Information Research of the Human Sciences Research Council in 1981 for the Department of National Education. The article is limited to a consideration of the aim and functions of national library services. Matters such as the organisation and management of these services, the pros and cons of centralisation and decentralisation in particular circumstances, bringing services into line with modern demands, problem areas in existing services, the raison d'être of national library and information advisory councils alongside the management councils of national library services, legislation of these services, etc. have been excluded from the discussion.

The main purpose of this paper is to identify, screen and prioritize customer requirements (CRs) for men’s denim jeans. Moreover, the effect of demographic factors on the primary evaluation criteria has been examined.

The study was initiated by the growing complaints about denim jeans products of a local manufacturing company. First, 24 CRs were identified from the literature and customer complaints. Then, a survey was conducted to rate the identified CRs and solicit more CRs through closed-ended and open-ended questions, respectively. From the survey, 368 usable responses were collected while the participants were shopping in 14 local retail shops. After analyzing the data using factor analysis, univariate and multivariate analysis of variance (MANOVA), and content analysis, the resulting 15 criteria were prioritized by experts’ pairwise comparisons employing the fuzzy analytic hierarchy process (AHP).

Factor analysis extracted six components (primary criteria) including design cues, pocket design, comfort, size and fit, fashionability, and extrinsic cues from the CRs included in the closed-ended questions. MANOVA showed that age and frequency of purchasing denim jeans significantly affected the primary criteria, while educational level and frequency of wearing denim jeans did not. The weights from the fuzzy AHP revealed that colour fastness, price, durability, fabric weight, workmanship, side pocket design and fit as the most important CRs. Moreover, consumers preferred regular fit, stitched round side pockets, patch back pockets and stretchable denim fabric.

The limitations of the study are discussed in the body of the paper in Section 7.

The paper presents exploratory findings on denim jeans evaluation criteria in a developing country’s context. Moreover, the application of fuzzy AHP for prioritizing denim jeans’ CRs is unique.

THE aim of this paper is to provide a survey of some of the principal theoretical considerations affecting the design of aircraft undercarriages.

THE bearing described in this article may help to solve many problems peculiar to aircraft design, where deflections of large orders are experienced between one location and another.

THE purpose of this article is to describe a useful variable velocity‐ratio unit suitable for inclusion in flying‐control circuits of aeroplanes, and to provide sufficient of a mathematical analysis to assist designers in the accurate production of such a device. Worked examples are included to illustrate the procedure, and draughtsmen should find these helpful and preferable to a trial and error method of layout on the drawing board.