In relational database management systems indexes are used to accelerate specific queries. The selection of indexes is an important task when tuning a database which is performed by a database administrator or an index propagation tool which suggests a set of suitable indexes. In this paper we introduce a new index approach, called keyoriented XML index (KeyX), that uses specific XML element or...

We present a novel approach for a tool that assists the database administrator in designing an index connguration for a relational database system. A new methodology for collecting usage statistics at run time is developed which lets the optimizer estimate query execution costs for alternative index conngurations. Deening the workload specii-cation required by existing index design tools may be...

abstract background: musculoskeletal disorders (msds) are a serious problem among the nursing staff. mental workload is the major cause of msds among nursing staff. the aim of this study was to investigate the mental workload dimensions and their association with msds among nurses of alzahra hospital, affi liated to isfahan university of medical sciences. materials and methods: this descriptive...

Background: Firefighting and rescue require high physical and psychological needs under unpredictable and dangerous conditions. Thus, this study aimed to investigate mental workload and affecting factors in firefighters. Materials and Methods: This is a descriptive study which was conducted on 250 firefighters of Tehran, Iran. National Aeronautics and Space Administration Task Load Index (NASA...

INTRODUCTION Two great changes in developed countries are taking place: populations are ageing and becoming increasingly overweight. Combination of these factors with shift work is a risk factor for work ability and mental workload that are dynamic processes which change greatly throughout an individual's work life. The aim of this study was to investigate mental workload and work ability in te...

OBJECTIVE A study was run to test which of five electroencephalographic (EEG) indices was most diagnostic of loss of vigilance at two levels of workload. BACKGROUND EEG indices of alertness include conventional spectral power measures as well as indices combining measures from multiple frequency bands, such as the Task Load Index (TLI) and the Engagement Index (El). However, it is unclear whi...

abstract background: mental workload is a general concept in the literature of ergonomics and human factors that are affected by external working demands, environmental, psychological and organizational factors, organizational and mental abilities. the aim of this study was to assess the mental workload and its impact on musculoskeletal disorders among nurses employed at different parts of the ...

  Background: The lack of satisfaction and balance between the workload and abilities and limitations of individuals in various occupations may influence their general health. The aim of this study was to determine the effect of workload and job satisfaction on the general health of industrial workers.   Materials and Methods: This was a cross-sectional and correlational study on 2...