A review of: “A Manager's Guide to Ergonomics in the Electronic Office. By MARVIN J. DAINOFF and MARILYN HECHT DAINOFF (Chichester John Wiley and Sons, 1987.) [Pp. xii + 230.] £19·95.

When polygon displays are used to represent multiple sources of information, sometimes they can be processed in parallel so that the significant information can be taken in ‘at a glance’. Previous studies found that reaction times (RTs) remained constant as the number of vertices was increased (Greaney and MacRae 1993). However, these studies did not call for the explicit identification of critical vertices and used polygons that were relatively regular. The present study required abnormal vertices to be identified, and it was found that RTs increased as a function of the total number of vertices. In addition, RTs were longer when the variability of the displayed information was greater, that is, when the polygon was more irregular. It was concluded that the polygon display may have more potential as a global warning indicator than as a means of displaying individual parameter values, which must be assessed separately.     

A review of:“People and Productivity”. Edited by Robert A. Sutermeister. (McGraw-Hill.) [Pp. 520.] 54s.

Abstract

The benefits for the consumer, and for the practising ergonomist of implementing a marketing strategy designed to increase consumer awareness of ergonomics is discussed with reference to the experiences of ICE Ergonomics, a commercial ergonomics research and consultancy organization based in Great Britain. The marketing strategy, which addresses the areas of publicity, education and practical involvement, forms one part of an integrated marketing strategy now being implemented by ICE.     

Review of:“Design of Man-Computer Dialogues” By James Martin. (Englewood Cliffs,N.J.: Prentice-Hall, 1973.) [Pp. xiii+559.] £8.30.

Abstract

An electromyographical field study was performed in the operating theatre on four surgeons during 15 urological operations. In the course of the operations two endoscopic techniques were applied alternately: (1) direct endoscopy, and (2) monitor endoscopy. During direct endoscopy the surgeon looks into the urethra and the bladder via an endoscope. In monitor endoscopy, by contrast, the operating area is observed via a video system consisting of a camera mounted on top of the endoscope and a monitor. During the operations surface electro-myograms were derived from both trapezius muscles, the right deltoideus muscle and the left erector spinae muscle. An activity code describing the surgeons’ activity was additionally recorded. Analysis of the activity recording reveals that the monitor endoscopic method is preferred in the first third of the operations, whereas preference is given to the direct method in the last third. The electromyographical measurements indicate that during monitor endoscopy the myo-electrical activity of both trapezius muscles and of the right deltoideus muscle is significantly reduced in comparison with the activity for the direct endoscopic technique. A significant influence of the surgical technique on the myoelectrical activity could not be established for the erector spinae muscle. The electromyographical findings reveal that the activity of the shoulder musculature required for the maintenance of the posture and the performance of the operation is significantly lower in monitor endoscopy than in direct endoscopy. Consequently, a clear reduction in muscular strain can be achieved during the performance of endoscopic operations in urology if a video system is employed.     

A review of: “Ways of the Hand. The Organisation of Improvised Conduct”. By D. SUDNOW. (London: Routledge & Kegan Paul, 1978.) [Pp. xiv + 155.] £6·50.

Traffic systems are undergoing enormous change with the advent of Intelligent Transport Systems (ITS). Although productivity and quality of mobility are emerging interests, safety remains the predominant preoccupation of ITS human factors. It should be evident that while intelligent technologies may have the potential to improve traffic safety, they also have the potential to adversely affect it. Ultimately, the effect on safety depends on the specific technologies that are invoked and the manner in which they are incorporated within the vehicle as well as within the larger road transportation system. Current automotive developments can be characterized as technology-centred solutions rather than usercentred solutions. Greater effort must be directed at understanding and accommodating the human element in the road transportation system in order that future transportation objectives can be achieved. There is a need to expand the scope of traditional human factors to include macro-level effects as well as to place greater emphasis on understanding human interactions with other elements of the system. There is also increasing recognition of the urgent need for systematic procedures and criteria for testing the safety of ITS prior to large-scale market penetration.     

A Review of: “The Psychology of Thinking”. By NEIL BOLTON. (London: Methuen; New York: Barnes and Noble, 1972.) [Pp. ix+291.] £3.20.

We are in the midst of a major shift in the way computers are designed and used. The architectures, both of computer systems and of the organizations which use them, are changing from hierarchies (‘tiers’) to networks (‘peers’). This gives us, as individuals and as a profession, a challenging opportunity to enlarge our ‘systems approach’ in order to help solve the difficulties which will inevitably arise from such a major shift.     

A review of: “System Identification—Parameter and State Estimation.” By PIETER EYKHOFF. (Bristol : John Wiley & Sons, 1974.) [Pp. 555.] Price £12.50.

This article extends the concept of input–output finite time stability (IO–FTS) to a class of hybrid systems, namely impulsive dynamical linear systems, which are systems that exhibit jumps in the state trajectory. Sufficient conditions are given for the analysis of IO–FTS and for the design of both static output and state feedback controllers, guaranteeing IO–FTS of the closed loop system. In the general case the presented results require to solve feasibility problems involving either linear matrix inequalities or bilinear matrix inequalities, which can be solved numerically in an efficient way by using off-the-shelf optimisation tools, as illustrated by the proposed examples.     

A Review of: “Fuzzy Sets and Their Applications”. By C. V. NEGOIT[Abreve] and D. A. RALESCU. (In Rumanian) (Bucharest: Editura Technica, 1974.) [Pp.219.]

This paper presents a new controller for position and force control of robotic devices interacting with passive environments. In this approach, for the manipulator dynamics in joint space, suitable output equations are defined which represent the position control and force control subspaces. The dynamics of the manipulator are projected along these subspaces to obtain the dynamics in the respective subspaces. The resulting dynamics are linearized and decoupled using a nonlinear input-state linearizing controller. For the position control subspace dynamics, desirable stability features are achieved through pole placement design. Along the force control subspace, a soft base is introduced, the compliance effect of which is controlled by an appropriate compensation term. Based on the force feedback information, this compensation is modifed online using an extended dynamics. Assuming a model of the passive environment, aspects of local stability of the controller have been discussed. The theory has been presented for a two-link planar manipulator example, based on which, a numerical simulation is discussed.     

A Review of:“Fundamentals of Psychology”. By FRANK A. GELDARD. ( New York,John Wiley and Sons. ) [Pp.437.] 57s.

Abstract

Industrial Design is a discipline which, despite an early pre-occupation with styling and making technology saleable, is now centrally concerned with user needs. This is reflected in Coventry's unique degree course in the Industrial Design/Transport Department at Lanchester Polytechnic. The course contains a significant commitment to Human Factors and this is evident in the range of design projects which are undertaken either by students or as sponsored research. The emphasis in these projects is on practical designs which meet user requirements.

This paper describes the following typical course projects:

1. The competition winning design for a dinghy which can be used as an emergency life-raft.

2. An adaptation of a standard front-wheel-drive car with a transverse slide seat to allow easy access for a wheel chair user.

3. The design for a bus seat which can be used either as a conventional seat or as a standee ‘lean’ seat.

4. Design of a vehicle for use by spina bifida children.

5. Design for a pedal driven power unit for transport and machine uses in Developing Countries.

6. The design of adult tricycles for the transport of mothers plus children under 5 yr.

It is concluded that greater collaboration between industrial designers and ergonomists would be possible if the latter published their data in a more accessible form, and that designers must place greater emphasis on the product evaluation aspect of their work.     

A review of: “Human Motor Actions: Bernstein Reassessed.” Edited by H. T. A. WHITING. (Oxford: North-Holland, 1984.) [Pp. xxxv + 633.] ISBN 0-444-86813-5.

The physical work performance of eight fit fire fighters wearing fire brigade uniforms and wearing breathing apparatus was assessed. They were tested in a climatic chamber set at temperatures of 15 and 45°C respectively. The test was performed with and without fire fighting equipment. The subjects walked on a treadmill at a speed of 3.5km/h, which produce a workload equivalent of 20% of the subjects' maximal oxygen uptake without equipment, and 30% with equipment. The test lasted for 60 min. Heart rate, oxygen uptake, skin and deep body temperatures were measured during the test. The subjects estimated perceived physical exertion and perceived temperature. Wearing fire fighting equipment increased the oxygen uptake by 0.4 1min^-1. Heart rate at the end of the experiments reached near-maximum levels when the temperature was 45°C with equipment, and deep body temperature increased to an average of 38.7°C. The subjects' ratings of perceived exertion were highly correlated to heart rate. The loading induced by heat and protective equipment reduced the ability to perform strenuous work. The combination of thick clothing and heavy breathing apparatus was found to have a significant limiting effect on the endurance of fire fighters.     

A Review of:“Safety in Manual Materials Handling.” By COLIN G. DRURY. (Cincinnati: US Dept. of Health,Education & Welfare, 1978.) [Pp. viii+ 209.]

The extension force against resistance was recorded in 23 postures for 12 subjects to find explanations for the decrease in back strength in asymmetric postures. A reduction in muscle force in asymmetric postures was found up to 40%, but was strongly dependent on the plane in which asymmetry occurred, and on the posture to which it referred. A quantitative relationship between the forces exerted in different asymmetric postures is discussed, as a basis for formulating universal ergonomic guidelines for optimal working postures. The reduction in force in different asymmetric postures can be explained by length of the muscle, the activation of the muscle, and the moment angle of the muscle.     

A review of: “Traffic on the Right Requires Steering on the Right.” By E. BORSARI and H. A. SCHWARZENBACH (Editors). (Zurich: Zollikon Action Committee for Introducing Right-Side Steering.) (Distributed through Orell Füssli Verlag,Zürich, 1967.) [Pp. 166.]

A link between subjects' preferences for certain labels over others in an Electronic Mail System (EMS) and their performance was established in an earlier study conducted in a pen/paper format. The same tasks were completed on a computer in this study to test the extent to which pen/paper studies may be indicative of subsequent performance on a computer. This link was found to be quite strong. Three further experiments, also carried out on the computer, isolated two other factors of importance for novices in their initial interaction with a computer. Pre-experimental training on a single task eliminated any effects of vocabulary, regardless of whether or not the serial position of items presented on the screen was randomized between trials, and of whether subjects saw the same or different lists of labels in the pre-experimental and the experimental phase. It was concluded that position constancy of items presented on the screen and knowledge of task requirements are as important for determining initial performance for novices as vocabulary.     

A Review of: “Exploration of the Solar System by Infrared Remote Sensing”. By R. A. HANEL,B. J. CONRATH,D. E. JENNINGS and R. E. SAMUELSON. (Cambridge: Cambridge University Press, 1992.) [Pp. 458.] Price £75.00.

Crop classification is a key issue for agricultural monitoring using remote-sensing techniques. Synthetic aperture radar (SAR) data are attractive for crop classification because of their all-weather, all-day imaging capability. The objective of this study is to investigate the capability of SAR data for crop classification in the North China Plain. Multi-temporal Envisat advanced synthetic aperture radar (ASAR) and TerraSAR data were acquired. A support vector machine (SVM) classifier was selected for the classification using different combinations of these SAR data and texture features. The results indicated that multi-configuration SAR data achieved satisfactory classification accuracy (best overall accuracy of 91.83%) in the North China Plain. ASAR performed slightly better than TerraSAR data acquired in the same time span for crop classification, while the combination of two frequencies of SAR data (C- and X-band) was better than the multi-temporal C-band data. Two temporal ASAR data acquired in late jointing and flowering periods achieved sufficient classification accuracy, and adding data to the early jointing period had little effect on improving classification accuracy. In addition, texture features of SAR data were also useful for improving classification accuracy. SAR data have considerable potential for agricultural monitoring and can become a suitable complementary data source to optical data.     

Review of: “Management by Motivation”By Saul W. Gellerman. (American Management Association,’1968.) [Pp. 286.] $0.

This paper examines the effects of different types of complexity facing novice designers in constraint satisfaction tasks. The nature of the complexity in a design task was varied by manipulating different aspects of the extrinsic constraints, which refer to restrictions concerning how design components can be assembled. We investigated the effect of the number of constraints (Study 1) and the number of different types of constraint (Study 2) in a simulated office design task. Results indicated that tackling a design task with a greater number of constraints, or more types of constraint, resulted in decrements in performance. Study 3 examined the effect of reasoning about constraints that involved a fixed location in the office layout and those that did not. It was found that having a higher proportion of constraints that referenced a fixed location led to better design performance. The theoretical and practical aspects of these results are discussed.

Practitioner summary: This paper identifies sources of constraint complexity facing the novice designer in an office design task. Three features of constraints proved problematic: the number of constraints, the number of types of constraint and whether the constraint involved a specific location. Training and decision support solutions are discussed.     

Review of: “Machine Intelligence 7”. Edited by Bernard Meltzeb and Donald Michie.(Edinburgh University Press, 1972.) [Pp. xiv+485.] £12.00.

To better assess the energy expenditure and exertion of firefighters during simulated firefighting activities, a commercial firefighter self-contained breathing apparatus (SCBA) facepiece was modified to interface with a portable metabolic monitoring device (Cosmed K4b²) while still functioning as a positive pressure SCBA air supply. To validate the device, standard National Fire Protection Association 1981 SCBA function tests were conducted and 14 subjects performed variable-workload assessments using all combinations of two test devices (Cosmed K4b² and metabolic cart) and two masks (modified SCBA facepiece and stock manufacturer-supplied breath collection). Metabolic data collected with the Cosmed K4b² via the modified facepiece were found to be accurate when compared to a ParvoMedics Truemax 2400 metabolic cart (average per cent difference: 4.6%). This modified facepiece design is suitable for use in metabolic studies requiring the utilisation of an SCBA system. Furthermore, the well-established overestimation of oxygen consumption from the Cosmed K4b² system was replicated.     

A review of: “Posture. Sitting,standing, chair design and exercise.” By D. ZACHARKOW. (Springfield,IL: Charles C. Thomas, 1988.) [Pp. xxi + 433.] US$49·75. ISBN 0-398-05418-5.

Drivers experiencing rush hour congestion were interviewed using cellular telephones to study stress and coping responses. Measures were taken of each driver's predisposition to stress (trait stress) as well as their reactions to the experience of either low or high traffic congestion (state stress). Two interviews were conducted during the trip when drivers experienced both low and high congestion conditions. Although state stress was greatest for all drivers experiencing the high congestion condition, a trait X situation interaction was obtained, indicating that stress levels were highest for high trait stress drivers experiencing the congested roadway. In terms of trait coping behaviours, participants indicated a preference for direct over indirect behaviours. A greater variety of direct and indirect behaviours were reported in high congestion. Reports of aggressive behaviours showed the greatest increase from low to high congestion. Comments on the use of cellular telephones in methodology are offered.     

A review of: “ Advances in Digital Image Processing: Theory,Application, Implementation ”. Edited by P. STUCKI. (New York,London: Plenum Press, 1979.) [Pp. 332.] Price $39·50.

Abstract

Radiometric balancing is a form of radiometric correction that can be applied to radar imagery. However, its application can be based on untenable assumptions about the characteristics of the scene and so can be unreliable. The method of radiometrically balancing an image and the requirements of the technique are outlined along with an example of where its use would be inappropriate. A recommendation is made against policies of pre-dissemination radiometric balancing and it is suggested that users should evaluate the use of other techniques which may be more suitable for their imagery.     

A review of: “Man and his Thermal Environment” By R. P. CLARK and O. G. EDHOLM. (London: Arnold, 1985.) [Pp.288.] £39·95. ISBN 0-7131-4445-9.

Abstract

A computer-video interactive system is described that enables a trained observer to systematically record and view the behaviour of athletes performing within a team-sport competition. This system is designed to allow the recall of selected video instances from previously recorded athletic behaviours. In order to accomplish this form of analysis, a computerized recording system and a video cassette recording machine were combined using specialized hardware and software. A system for the analysis of field hockey is used to exemplify how the interaction of computers and video recorders can aid in the sport analysis process.     

A review of: “Health Hazards of the Human Environment.” (Geneva: World Health Organization, 1972.) | Pp. 387.] £4 40

This study investigated coordination of the grip force on and force applied with a hand tool using a precision pinch grip. A simulated hand tool was developed to measure grip force exerted on the tool as a function of the force transmitted from the tool to an external object in a dynamic force matching paradigm. Grip force coordination measures reflected subjects' abilities to modulate grip force in parallel with the tool application force and their abilities to minimize excessive grip force. These measures were calculated for seven subjects with a diagnosis of carpal tunnel syndrome (CTS) and seven age- and gender-matched controls. The absolute magnitude of excessive grip force (safety margin) was unreliable because of the high intrasubject variability in coefficient of friction measurements. Linear regression equations predicting coefficient of friction from pinch force magnitude had low r ² coefficients of determination and were generally not statistically significant (p &;gt; 0.05). Relative comparisons of grip force control showed that individuals with CTS exhibited a statistically significant (p &;lt; 0.05) increase in ratio of grip force to application force (54% higher than controls) and a significant (p &;lt; 0.05) decrease in modulation of pinch force with application force (12% lower than controls). These results suggest that individuals with CTS lose some ability to coordinate efficiently grip force on hand tools and exert higher grip forces on tools, at equivalent application forces, than controls. This is believed to be a result of tactile sensibility deficits associated with CTS. As a result, workers with CTS may be at increased risk of accelerating the progression of their musculoskeletal disorder.