Analysis of occupational health hazards and associated risks in fuzzy environment: a case research in an Indian underground coal mine

This paper presents a unique hierarchical structure on various occupational health hazards including physical, chemical, biological, ergonomic and psychosocial hazards, and associated adverse consequences in relation to an underground coal mine. The study proposes a systematic health hazard risk assessment methodology for estimating extent of hazard risk using three important measuring parameters: consequence of exposure, period of exposure and probability of exposure. An improved decision making method using fuzzy set theory has been attempted herein for converting linguistic data into numeric risk ratings. The concept of ‘centre of area’ method for generalized triangular fuzzy numbers has been explored to quantify the ‘degree of hazard risk’ in terms of crisp ratings. Finally, a logical framework for categorizing health hazards into different risk levels has been constructed on the basis of distinguished ranges of evaluated risk ratings (crisp). Subsequently, an action requirement plan has been suggested, which could provide guideline to the managers for successfully managing health hazard risks in the context of underground coal mining exercise.     

The relationship among enterprise clustering,prices, and productivity in Ethiopia’s manufacturing sector

We use census panel data on Ethiopian manufacturing firms to analyze how enterprise clustering in local markets covaries with firm‐level output prices and physical productivity. We find a negative and statistically significant relationship between the density of firms that produce a given product in a given location and the local price of that product. We also find a positive and statistically significant relationship between the density of firms that produce a given product in a location and the physical productivity of same‐product firms in the location. These results are consistent with the notion that increased clustering of firms generates higher competitive pressure and positive externalities. Across firms that produce different products, we find no statistically significant relationship between enterprise clustering and firm‐level output prices and productivity. We also find no clustering effects across towns. Our results suggest that while clustering can impact firm performance, the advantages are narrow in scope.     

A risk-based decision support framework for selection of appropriate safety measure system for underground coal mines

In the context of underground coal mining industry, the increased economic issues regarding implementation of additional safety measure systems, along with growing public awareness to ensure high level of workers safety, have put great pressure on the managers towards finding the best solution to ensure safe as well as economically viable alternative selection. Risk-based decision support system plays an important role in finding such solutions amongst candidate alternatives with respect to multiple decision criteria. Therefore, in this paper, a unified risk-based decision-making methodology has been proposed for selecting an appropriate safety measure system in relation to an underground coal mining industry with respect to multiple risk criteria such as financial risk, operating risk, and maintenance risk. The proposed methodology uses interval-valued fuzzy set theory for modelling vagueness and subjectivity in the estimates of fuzzy risk ratings for making appropriate decision. The methodology is based on the aggregative fuzzy risk analysis and multi-criteria decision making. The selection decisions are made within the context of understanding the total integrated risk that is likely to incur while adapting the particular safety system alternative. Effectiveness of the proposed methodology has been validated through a real-time case study. The result in the context of final priority ranking is seemed fairly consistent.