Human Performance Requirements Research Articles

Research on digital soft start method of boost DC-DC switching power supply

Due to the progress of science and technology and the rapid development of the economy, human performance requirements for electronic products are getting higher and higher. Therefore, it is necessary to study a Boost-type DC-DC converter with high conversion efficiency, miniaturization, strong stability, and fast start speed. Currently, there are many ways to solve the DC-DC switching power supply problem. By analyzing the switching power supply, an efficient digital soft start method for boosting DC-DC switching power supply. This method adopts programmable digital technology. By precharging the output capacitor with the multiplexed substrate switching circuit, the output current rises steadily, and the soft start effect of the switching power supply is achieved. Based on the 0.18um BCD process, the test shows that when the input voltage is 3.7 V, the output voltage is 4.6 V, and the duty ratio is 20%, the soft start time is 210 us when the PVT changes and the steady rise of the output voltage does not produce the surge current phenomenon. Through theoretical analysis and experimental verification, the proposed method has the obvious advantages of simple structure, strong stability, low power consumption, and fast starting speed.

Evaluation of Human Error Probability of Disc Brake Unit Assembly and Wheel Set Maintenance of Railway Bogie

The railway sector is key to the continuous expansion of industrialized nations, but the sector's working conditions and human performance requirements are qualitatively different from other industries. Human error in railway maintenance is a subject which warrants serious attention so as to achieve and sustain a competitive advantage. This paper investigates the probability of human error during the maintenance process of disc brake assembly unit and wheel set of railway bogie under various error producing conditions in railway maintenance workshop in Luleå, Sweden. The objective is to evaluate human error probability so as to take measures to reduce the likelihood of errors occurring within a system and, thus, to improve the overall levels of safety. For this paper, a case study that explores the causes of maintenance error during disassembly, inspection, maintenance, assembly and installation was derived from brain storming sessions among subject matter experts (SMEs), i.e technicians, supervisors and academic experts. In our case study, the Human Error Assessment and Reduction Technique (HEART) was implemented to evaluate the probability of human error occurring throughout the completion of maintenance task. HEART is based upon the principle that every time a task is performed on the maintenance of a disc brake assembly unit and wheel set, there is a likelihood of failure and the probability of this is affected by one or more error producing condition, for instance, shortage of time, over-riding information, inexperience etc. This paper presents the need for interventions in the human factor elements of maintenance tasks performed on railway bogie. A number of factors directly or indirectly result in a decline in human performance, leading to errors in maintenance tasks. The probability of a technician committing an error during maintenance of the disc brake assembly unit and wheel set is found to be 0.20 and 0.039 respectively. It has been observed that error producing conditions such as time pressure, ability to detect and perceive problems, the existence of over-riding information, the need to make absolute decisions, and a mismatch between the operator and the designer's model are major contributors to human error.

New type of standard for accessibility, designed to foster the competition and innovation of designers, developers, and project and business management

This paper describes the many beneficiaries of accessibility to IT, creating a multifaceted business opportunity. Evolution is underway as some organizations and governments develop and adopt accessibility standards and regulations. But organized planning, design and development of technology solutions require improved tactics and strategies. The very recent US Section 508 is a new and novel regulatory marketing strategy in the evolution of standards. This regulatory standard's effectiveness dependents upon the 'innovation and divergent thinking' of those directly involved in product design. Designers, developers and their management are most comfortable with an analytical structure based on improved definition and measurement. Research will improve understanding of the human performance requirements of the client audience. Research and standards should continue but certain areas are in need of more immediate focus, e.g. human performance requirements in cognition.

Situation-Adaptive Degree of Automation in Man-Machine Systems: Theoretical and Experimental Validations

This paper investigates responsibility allocation between human and computer in semi-autonomous processes. It is proven theoretically and experimentally that responsibility allocation must be situation-adaptive for process safety. Factors considered include: (1) reliability of an alarm system, (2) human’s trust on machine intelligence, (3) human performance requirements, (4) process dynamics, (5) time-pressure for a prompt decision making.

Guidelines for the Selection of Gloves for the Workplace

The selection of gloves for the workplace can be accomplished using a seven step process including consideration of alternatives to protective clothing, evaluating the nature and extent of the hazard, determining material and human performance requirements for the gloves, and cost. The primary determinant is protection of the worker. Gloves selected for protection against chemical hazards should be chosen based on permeation resistance. No single glove is available that can provide all desirable chemical and physical properties, hence, compromise is usually necessary.

Automation and Supervisory Control: A Perspective on Human Performance, Training, and Performance Aiding

This paper is based on results from an on-going effort sponsored by the US Army Research Institute (ARI) concerned with human performance and training issues in automated, near-real-time air defense command and control systems. Air defense command and control is the specific applications context, but the paper's implications extend to many contemporary process control settings. Topics that are addressed in the paper include: (1) human performance problems associated with automation, (2) a new look at human performance requirements in near-real-time process control, (3) and training and job performance support requirements for supervisory controllers. The “new look” portion describes a reasonable and evolving concept for human participation in automated processing, designated Rule-Based Supervisory Control. The paper is intended to introduce these topics to concept developers, system designers, and trainers dealing with automated process control technology.

International human factors experience : E.W. Hagen (Ed), Conference Record for 1988 IEEE 4th Conf on Human Factors and Power Plants, Monterey, Cal, 5–9 June 1988. Institute of Electrical and Electronics Engineers, New York, 1988, pp 69–72, 0 refs

The author examines the various issues involved in the safety enhancement of nuclear power plants worldwide in connection with human factor engineering. In particular, he considers the concentration of the International Atomic Energy Agency on the following issues: (1) operator qualification, education and training to increase the 'nuclear safety culture' in nuclear power plant operation; (2) human performance requirements; (3) the man-machine interface, with particular emphasis on the balance between automation and direct human action and in the need for additional operator support systems in the nuclear power plant control room; and (4) human error data collection and modelling. >

Human Performance Requirements for an Innovative Transit Bus Operation

Human performance requirements for an innovative transit bus operation system utilizing exclusive bus lanes in a downtown are described. Requirements for transit company personnel and bus patrons are discussed. Performance levels achieved during a test and demonstration of the system in downtown Rochester, New York are analyzed. Transit company personnel performed at an average level of 94% compliance with their particular requirements; bus patrons at an average level of 87 percent. Overall compliance level (transit personnel plus patrons) was 74 percent. The system was found to be feasible; it was successfully integrated into regular transit operations. It provided a reserve capacity potential 26% above the then-scheduled flow. Computer simulation using Rochester, New York parameters as inputs suggest that, with certain operational changes, potential capacity could be increased 59% over flows scheduled at the time of the experiment.

Bus Modification to Improve Safety, Comfort, and Human Reliability

The MITRE Corporation has made a preliminary analysis of the needs of bus patrons, with emphasis on the needs of the disabled. This analysis, based on observations and consultation with specialists was used to derive human performance requirements for average, aged and disabled patrons, and for the driver. The bus modification kits described are intended to increase human reliability and safety. To accomplish this the kits should improve: Information on the identification of buses, routes, and destinations; access, equilibrium, and egress for the disabled, with a minimum of assistance; recognition and use of emergency exits; nighttime visual access for drivers and patrons; familiarity with vehicle accessories; and safety under mobile or emergency conditions. Modification kits are evaluated on the basis of effectiveness, and costs of research, development, production, and installation. Since it may be impractical to install all kits immediately, they are recommended for implementation on the basis of effect on utility of transportation for the aged and disabled. The following kits meet this criterion: Public Address, Route Identification, Handrails, Stanchions, Raised Seat, and Extended Step.