Ergodynamics and Hybrid Intelligence Systems in the Reliability of Power Plant Operators Valery F. Venda, Svyatoslav A. Chachko, 93-108 Handgrip and Box Tilting Strategies in Handling: Effect on Stability and Trunk and Knee Efforts Alain Delisle, Micheline Gagnon, Pierre Desjardins, 109-118 Permeability of Organic Solvents Through Two-Layer Safety Gloves Determined by a Gravimetric Method Jolanta Liwkowicz, 119-127 Characteristic of Muscular Load in Computer Data Entry Workers Assessed by EMG and Postural Angles Danuta Roman, Joanna Bugajska, Maria Konarska, 128-136 Alveolar Macrophage (AM) Mobility Reduction as a Result of Long-Term Exposure To High Dust Concentration in Inhaled Air Leon Gradoń, Albert Podgórski, 137-147 An Investigation of Stress Level and Human Reliability Analysis of Two Security Companies in Taiwan Jacob Jen-Gwo Chen, Yueh-Wen Chen, 148-163 A Contribution to the Study of the Anti-Dust Respirators' Real Performance Sławomir Zakrzewski, Katarzyna Majchrzycka, Agnieszka Brochocka, Krzysztof Makowski, 164-170

Notes:

Algorithms for Increasing the Efficiency of Precision Production Operator's Activities Vladimir V. Savchenko, 173-181

Ergodynamics and Hybrid Intelligence Systems in the Reliability of Power Plant Operators
Valery F. Venda, Svyatoslav A. Chachko, 93-108

Based on ergodynamics and the hybrid intelligence theory, an analysis of the nuclear power plant operator's performance is given at the levels of strategies, tactics, and actions. Special attention is paid to the strategies used in the course of severe accidents at nuclear power plants. Data from Ukrainian and Russian power plants and training centres, and from accidents around the world were collected and processed. It is shown that in an emergency it is essential for the human operator to be flexible. This flexibility includes two main training and personal factors: a large set of strategies and tactics the operator manages to use, and quick transformations between the strategies (tactics). It was also found that some emergency tasks are too complicated: They require simultaneous use of different strategies, with time strictly limited by nuclear power plant dynamics. Those tasks cannot be successfully solved by any individual operator. Hybrid intelligence systems involving different specialists should be used in those cases in order to avoid failures in emergency problem solving.

Handgrip and Box Tilting Strategies in Handling: Effect on Stability and Trunk and Knee Efforts
Alain Delisle, Micheline Gagnon, Pierre Desjardins, 109-118

The purpose of this study was to evaluate the effect of four handgrip-box tilting strategies (right, left, backward, and no tilt of the box) on trunk and knee efforts, body posture, and the stability of 14 participants with limited experience in handling. The tasks consisted of transferring a low-lying box placed in front of the participant to a shelf of the same height at the participant's left. It was hypothesized that tilting the box could reduce trunk and knee efforts as well as body asymmetry, and improve stability. A tridimensional dynamic rigid body model was used to estimate the triaxial net muscular moment magnitudes at the trunk (L5/Sl) and at the knees. An approach to quantify the participants' dynamic stability was also included. Finally, 5 angles were computed to characterize body asymmetries. The results showed that tilting the box affected specific trunk efforts, but did not succeed in reducing trunk asymmetric efforts. However, the tilts were executed in a single direction, and it may be possible that combined tilts of the box could help reduce trunk asymmetric efforts. Tilting the box had little effect on knee loadings, and the left tilt strategy reduced participants' stability. This study showed the importance of considering the position of the box when assessing the risks encountered in asymmetrical handling.

Permeability of Organic Solvents Through Two-Layer Safety Gloves Determined by a Gravimetric Method
Jolanta Liwkowicz, 119-127

Organic solvents are harmful to humans and many of them are recognized as carcinogens. Therefore it is necessary to protect hands from contact with them. Most methods for testing solvent resistance of gloves use Gas Chromatography. However, these methods are expensive and so complex that they present application problems for most glove producers and users.
   A simple gravimetric method to test solvent resistance of gloves was developed. It was tested by measuring permeability of organic solvents such as white spirit, acetone, isopropyl alcohol, benzene, p-xylene, trichloroethylene, through gloves made of natural rubber, polivinyl chloride, neoprene, perbunan, polivinyl alcohol, and two-layer gloves made of natural rubber and neoprene. This method proved to be a simple, economical, and reliable way to examine glove permeability.

Characteristic of Muscular Load in Computer Data Entry Workers Assessed by EMG and Postural Angles
Danuta Roman, Joanna Bugajska, Maria Konarska, 128-136

The goal of this study was to characterize the muscular load in computer data entry workers. Electromyography (EMG) parameters of trapezius muscle and postural angles of head, arm, and back were chosen as indicators of musculoskeletal load. The examination was done according to the methods and protocol of international MEPS studies (the "Musculoskeletal, Visual, and Psychosocial Load in VDT [Video Display Terminal] Operators in Optimized Environment" international program). The musculoskeletal load during routine VDT data entry work performed by a group of 36 women was assessed on the basis of 1-h physiometer recordings. Results show that the musculoskeletal load associated with data entry is relatively high comparing to other VDT operators' tasks described in the literature. An analysis of the measured parameters shows that most of the time women worked with a muscular load higher than optimal. It is postulated that the main reason for the heavy musculoskeletal load was improper posture compelled by unergonomic spatial configuration of work stands.

Alveolar Macrophage (AM) Mobility Reduction as a Result of Long-Term Exposure To High Dust Concentration in Inhaled Air
Leon Gradoń, Albert Podgórski, 137-147

The influence of high concentration of insoluble particles in inhaled air on the alveolar macrophage (AM) mobility is analyzed. Kinetics of phagocytosis and the mobility of AM as a function of overloading is proposed. Three patterns of AM displacement on the surface of alveolus are distinguished depending on the loading of the surface with insoluble deposits, namely, directional being a result of surfactant activity, directional with a chemotactic bias, and purely random. The exit time of AM from alveolus under overloading is calculated.

An Investigation of Stress Level and Human Reliability Analysis of Two Security Companies in Taiwan
Jacob Jen-Gwo Chen, Yueh-Wen Chen, 148-163

This article presents the results of an evaluation and comparison study of 3 subjective techniques for determining human reliability under stress for work performed at 2 Taiwanese security companies. Stress levels at security companies were estimated by using the Unified Tri-service Cognitive Performance Assessment Battery and 40 participants from 2 similar-size companies. Experiment results (memory searching task and mathematical processing task) indicated that the participants were under high levels of stress. Three subjective techniques (Success Likelihood Index Method, Technique for Human Error Rate Prediction, and Human Error Assessment and Reduction Technique) for estimating human error probability were evaluated and compared by using 20 experts for 6 tasks. The comparison criteria are interjudge consistency and accuracy. Of the 3 human error probability tests studied, the Technique for Human Error Rate Prediction and Success Likelihood Index Method were more consistent than the Human Error Assessment and Reduction Technique. The same relationship occurred in the comparison of accuracy. Thus, Human Error Assessment and Reduction Technique may need to be modified in some way if it is to be useful. It was already known that this technique required modifications in error producing conditions and nominal human unreliability. Our work presents additional evidence to substantiate this.

A Contribution to the Study of the Antidust Respirators' Real Performance
Sławomir Zakrzewski, Katarzyna Majchrzycka, Agnieszka Brochocka, Krzysztof Makowski, 164-170

In most industrial enterprises hazardous factors are present in quantities exceeding permissible levels. Such a situation requires using anti-dust respiratory protection. It has been suggested, however, that filters for respirators are not assessed properly and that lab results might not be related to real filtering efficiency in industry. This paper contains test results of some commercially available filtering half-masks, including the effect of loading with real dust, high humidity, high temperature, and a combination of loading with dust and high humidity on the half-masks' performance. The results show that the effect of these factors is considerable and that a combination of loading with silica dust and exposing to high humidity can cause a complete loss of the performance.