Bengt Sandblad

Future train traffic control: control by re-planning

Improving train traffic control can be a cost-efficient way to improve train traffic punctuality and increase utilization of existing and future railway infrastructure. However, performance in train traffic control tasks currently involves working on a technical level in order to regulate the traffic flow. Working in a preventive manner is poorly supported and train traffic controllers are usually restricted to just solving problems as they occur. This often results in unnecessarily long delays and decreased timeliness of train traffic. The main objective of this paper is to describe a proposed control strategy and a case study, which evaluates the control strategy and the prototype tool derived from the research. By shifting the control paradigm to a high-level control strategy, many of today’s problems may be avoided, with benefits of the reduction in delays, improved timeliness and better utilization of the infrastructure. Twenty-one train traffic controllers participated in a case study, with a simulated prototype environment. The majority of the participating train traffic controllers were positive to the new concepts and ideas. Many of the important aspects of the proposed control strategy can be investigated with the simulation, but due to the complexity of train traffic some issues must be evaluated in an operative environment.

The art of the obvious

In addition to normal reading, knowledge can be gained from a paper document by pattern recognition and encoding of characteristics of the information media. There are reasons to believe that this can be done automatically with very little attentional demand. The knowledge gained is accessible to consciousness and can be used for task components like orientation, navigation, detection of changes and as a complement to normal reading. When information is computerized, and is read from a screen instead of from a paper, the conditions for automaticity are often radically changed. In most cases the reader has to gain the corresponding knowledge by effortful cognitive processes. This means adding to the cognitive load leaving less attentional capacity for the main task at hand. This problem can be avoided by a careful analysis of a reading task into its automatic and non-automatic components, followed by a dedicated user interface design where information relevant for orientation, navigation, etc. is presented in a way that the reader can perceive rather than read.

Work environment and computer systems development

Work environment and occupational health problems of different nature are constantly increasing in computer supported work. Most efforts to improve the work environment are focused primarily on physical aspects, and to some extent on psychosocial aspects. Mental workload and cognitive problems are of a more complex nature, more difficult to measure and provide efficient solutions to, and are more seldom studied or solved. Solutions to work environment problems are usually applied to already existing work situations through improved equipment and work place design, health programmes, education, reorganizations, etc. The problems are seldom prevented by means of applying relevant methods early in the systems development process, before the artefacts have been designed and implemented. This paper, and the following papers of this special issue, will focus on the need to integrate different interdisciplinary methods at different phases in the development process of computerized support systems, with the ultimate goal to prevent work environment problems and decrease the health risks to the users.

Domain-specific design of user interfaces

The use of graphical user interfaces in a computerized work environment is often considered to substantially improve the work situation. The outcome can, however, often be the opposite. Inappropriate use of windowing techniques, scrolling, and colors can result in tedious and confusing interaction with the computer. Todays standards and style guides define basic design principles but are insufficient for design of interfaces to end‐user applications. Here detailed domain knowledge is indeed essential. A domain‐specific style guide (DSSG) is an extension of todays standard with domain‐specific primitives, interface elements, and forms, together with domain‐specific guidelines. Careful dedicated analysis of information utilization in a domain is the development basis for a DSSG. The development is performed with an object‐oriented approach to facilitate the reuse of interface components and to support consistency and structure. Using a DSSG, the development of applications can be performed with a simplifi...

Integrating work environment considerations into usability evaluation methods—the ADA approach

The ADA-method is an attempt to integrate work environment issues into a usability evaluation method. The intention is to provide a method that can be used for the analysis of computer systems that ...

The interface is often not the problem

Computer systems in the form of tools for specific functions within a work environment are becoming increasingly common. Because the users are not computer experts, and because the introduction of the new tools can dramatically change their tasks, problems arise. It is argued that even if the proper design of the MMI is very important, this will not solve all the problems. More basic problems concern what functions should be included in the system and how the users can understand what the system can do in different work situations and how the response should be evaluated in the context of the work situations. This is demonstrated by experiences from application projects. It is concluded that more research must be devoted to these problem areas. Another important result is the fact that the possibilities to develop more generally applicable computer based tools are limited. Adaption to local circumstances and needs is usually a necessity.

Generation‐dependent control mechanisms in cell proliferation and differentiation—the power of two

Abstract. There is evidence that the proliferation of cells is controlled by the number of divisions after leaving a multi‐potent (stem) cell. A detailed study of the growth of tissue in the small intestinal tract, more precisely the growth of crypts and villi, suggests that not only the proliferation but also the differentiation of cells obey the same biological law. We postulate a theory of a cellular internal control mechanism: the cell‐generation control of differentiation and proliferation. This basic mechanism, together with extemal influences, determines the kinetic behaviour of the crypt‐villus system.

Analysis of information utilization (AIU)

Analysis of information utilisation (AIU) is a method for specifying how information entities encountered in information analysis are being physically manipulated in the work situation undergoing a ...

A simulation model for studies of intestine cell dynamics

A dynamic simulation model for the epithelial cell structures of the intestine has been developed. The model is based on hypotheses found in the literature. It is shown that basic cell dynamics can be reproduced by simulation experiments. The simulation program is designed so that model output comparable with experimental findings can be obtained. The use of a dynamic simulation model can be interpreted as a simulated experiment in vivo. The model therefore allows analysis of dynamic behaviour that cannot be performed by normal experimental work. This means that the model can be used as a tool for verification/falsification of hypotheses about dynamics in both normal and abnormal cell structures.

User certification of workplace software: assessing both artefact and usage

This article summarises activities and results from the quality assessment project ‘Quality Assurance of IT Support at Work’ (ITQ) which has been performed by Swedish researchers in close cooperation with trade unions 1999–2005. The ITQ project is part of a network, UsersAward, which works for the goal to develop and implement a strategy for good software products on the work floor. A main result of the ITQ project is the first version of a software certification programme, User Certified 2002, which is described in some detail. The underlying theoretical arguments for its design and the performed pilot projects which have informed its implementation are also presented. The outcome of performed certifications is discussed in terms of stakeholder response; in terms of whether to certify artefact, processes, or both; and in terms of the relationship between software certification, standardisation, and public procurement agreements. One conclusion from the project is that a viable software certification programme has to cover the softwares built-in features, its deployment process, and its actual situated usage. A second conclusion is that the buying organisation has to implement integrative processes in which its organisational development and its implementation of IT systems are coordinated. Conclusions are also drawn with respect to the set of organisational patterns underlying the UsersAward initiative – certifications, user panels, user surveys, user conferences and a yearly IT Prize contest. Finally, implications and plans for the future, especially international research and union cooperation activities, and further development of the certification process are described.