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A method is described by which systems may be represented as a collection of interlocking shells which indicate the boundaries of the components. It is suggested that this method gives a good visual impression of basic systemic properties such as openness, types of interaction, relative power of components, hierarchies and levels of organization.

This article summarises different approaches to defining what constitutes a drug‐related death (DRDs) and how they can be classified. DRDs usually fall into two broad categories: (a) those directly attributable to the consumption of drugs (both illegal and licit) eg. overdose and poisoning, and (b) indirect ‐ those which occur as a consequence of having a drug habit that exposes individuals to the risk of dying in some other way, eg. blood‐borne infections, accidents. Most attention is currently given to direct or ‘acute’ DRDs rather than the long‐term consequences of drug abuse. Problems associated with accurately deriving DRD statistics are outlined. Despite their limitations, such information is essential for identifying issues related to drug use and measuring progress against targets set for reducing DRDs.

In this paper, the contaminating role of socially desirable responding (SDR) in the investigation of “dark-side” aspects in international services marketing is examined. The main question to be answered is whether or not relationships between consumer ethnocentrism towards international services and its antecedents are biased by SDR, manifesting itself as impression management by respondents. The results of an empirical study confirm that conscious impression management indeed is likely to represent a serious threat in this type of consumer behavior-related research. The relationship between cultural openness and consumer collectivism on the one hand and consumer ethnocentric tendencies towards foreign services on the other hand was found to be biased by SDR. Such bias, however, could not be found for the other antecedents, namely patriotism and conservatism. This suggests that whether or not respondents engage in impression management depends on the conceptual character of the constructs being studied in international services research. Accordingly, the results have several implications for international services research practice.

Despite of the numerous characteristics of the multirotor unmanned aircraft systems (UASs), they have been termed as less energy-efficient compared to fixed-wing and helicopter counterparts. The purpose of this paper is to explore a more efficient multirotor configuration and to provide the robust and stable control system for it.

A heterogeneous multirotor configuration is explored in this paper, which employs a large rotor at the centre to provide majority of lift and three small tilted booms rotors to provide the control. Design provides the combined characteristics of both quadcopters and helicopters in a single UAS configuration, providing endurance of helicopters keeping the manoeuvrability, simplicity and control of quadcopters. In this paper, rotational as well as translational dynamics of the multirotor are explored. Cascade control system is designed to provide an effective solution to control the attitude, altitude and position of the rotorcraft.

One of the challenging tasks towards successful flight of such a configuration is to design a stable and robust control system as it is an underactuated system possessing complex non-linearities and coupled dynamics. Cascaded proportional integral (PI) control approach has provided an efficient solution with stable control performance. A novel motor control loop is implemented to ensure enhanced disturbance rejection, which is also validated through Dryden turbulence model and 1-cosine gust model.

Robustness and stability of the proposed control structure for such a dynamically complex UAS configuration is demonstrated with stable attitude and position performance, reference tracking and enhanced disturbance rejection.

OWING to the comparatively early date in the year of the Library Association Conference, this number of THE LIBRARY WORLD is published so that it may be in the hands of our readers before it begins. The official programme is not in the hands of members at the time we write, but the circumstances are such this year that delay has been inevitable. We have dwelt already on the good fortune we enjoy in going to the beautiful West‐Country Spa. At this time of year it is at its best, and, if the weather is more genial than this weather‐chequered year gives us reason to expect, the Conference should be memorable on that account alone. The Conference has always been the focus of library friendships, and this idea, now that the Association is so large, should be developed. To be a member is to be one of a freemasonry of librarians, pledged to help and forward the work of one another. It is not in the conference rooms alone, where we listen, not always completely awake, to papers not always eloquent or cleverly read, that we gain most, although no one would discount these; it is in the hotels and boarding houses and restaurants, over dinner tables and in the easy chairs of the lounges, that we draw out really useful business information. In short, shop is the subject‐matter of conference conversation, and only misanthropic curmudgeons think otherwise.