Wyniki wyszukiwania - BazTech

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Worksheets for Computing Recommended Notebook Computer and Workstation Adjustments

Nanthavanij S., Udomratana C., Hansawad S., Thepkanjana J., Tantasuwan W.

International Journal of Occupational Safety and Ergonomics

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2013

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Vol. 19, No. 2

259--274

EN

This paper discusses the design and development of worksheets for helping notebook computer (NBC) users to compute NBC and workstation adjustments so as to assume an appropriate seated posture. The worksheets(one for male users, the other for female ones) require the following information: body height, NBC screen size, work surface height, and seat height. The worksheets contain tables for estimating recommended NBC base angle, NBC screen angle, body–NBC distance, work surface height, and seat height. Additionally, they include flow charts to help NBC users to determine necessary adjustment accessories and their settings.

2

On Evaluation and Localization of Auditory Warning Devices for Adequate Audibility

Asawarungsaengkul K., Nanthavanij S.

International Journal of Occupational Safety and Ergonomics

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2013

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Vol. 19, No. 3

355--369

EN

This paper presents an analytic procedure to assist safety practitioners in evaluating the audibility of an existing auditory warning system in their workplaces. Two alarm location models are described: (a) a model with an unknown signal sound level, and (b) a model with a known signal sound level. A heuristic algorithm to determine a minimum number of alarm devices and their locations so that the warning signals can be clearly heard by workers is also proposed. The algorithm considers the ambient noise level, noise levels generated by individual machines, locations where workers are likely to be present, and noise levels at worker locations. From the numerical examples and the computation experiment, both the optimization and heuristic approaches yield solutions that satisfy the 15-dBA constraints. The heuristic approach is efficient in solving large alarm location problems due its capability to find near-optimal solutions within reasonable computation time.

3

Heuristic Procedure for the Assembly Line Balancing Problem With Postural Load Smoothness

Jaturanonda C., Nanthavanij S., Das S. K.

International Journal of Occupational Safety and Ergonomics

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2013

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Vol. 19, No. 4

531--541

EN

This paper presents a heuristic procedure for assigning assembly tasks to workstations where both productivity and ergonomics issues are considered concurrently. The procedure uses Kilbridge and Wester’s algorithm to obtain an initial task–workstation assignment solution which minimizes the balance delay of an assembly line. A task reassignment algorithm was applied to improve the initial solution by exchanging assembly tasks, which smooth postural load among workers, between workstations. A composite index of variation was used to measure the effectiveness of the task–workstation assignment solution. On the basis of clothes assembling, it was found that the task–workstation assignment solution with a minimum composite index of variation can be obtained with relatively equal weights in balance delay and postural load.

4

Heuristic Job Rotation Procedures for Reducing Daily Exposure to Occupational Hazards

Yaoyuenyong S., Nanthavanij S.

International Journal of Occupational Safety and Ergonomics

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2008

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Vol. 14, No. 2

195--206

EN

This paper discusses 2 heuristic job rotation procedures for preventing industrial workers from being excessively exposed to ergonomics and safety hazards in their workplaces. The objective of the procedures is 2-fold: (a) to find a minimum number of workers required for the given set of jobs, and (b) to determine a set of safe worker–job–period assignments such that all workers’ exposure to hazard does not exceed the permissible limit. Here, occupational hazards are divided into 2 categories: single- and variable-limit hazards. In the first category, workers are considered to have equal capability to withstand the hazard; in the second category, the limit of hazard exposure varies for different individuals. Numerical examples are presented to demonstrate the procedures.

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Decision Support System for Designing Effective Noise Hazard Prevention Strategies

Asawarungsaengkul K., Nanthavanij S., Chalidabhongse J.

International Journal of Occupational Safety and Ergonomics

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2007

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Vol. 13, No. 4

451--470

EN

A decision support system for designing effective noise hazard prevention (NHP) strategies is proposed. NHP consists of four modules: (a) database, (b) input, (c) algorithms, and (d) solution. The user can choose among single-, two-, and three-approach solution procedures. Heuristic and genetic algorithms are used to determine appropriate noise controls (NCs). From the given noise condition and NC budget, NHP recommends a minimum-cost NHP strategy that prevents any worker’s daily noise exposure from exceeding the permissible level. If the budget is insufficient, NHP is able to search for a feasible noise hazard strategy that requires a minimum NC budget.

6

Design of Optimal Noise Hazard Control Strategy With Budget Constraint

Asawarungsaengkul K., Nanthavanij S.

International Journal of Occupational Safety and Ergonomics

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2006

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Vol. 12, No. 4

355--367

EN

An analytical design procedure to determine optimal noise hazard control strategies for industrial facilities is presented. Its objective is to determine a set of appropriate noise controls to eliminate or reduce noise levels so that workers’ daily noise exposure does not exceed a permissible level. From a given noise control budget, engineering controls will be firstly implemented, followed by administrative controls, and then the use of hearing protection devices. Six optimization models are developed and sequentially applied to select appropriate noise controls without exceeding the budget. Numerical examples are presented to demonstrate the application of the proposed design procedure.