A real-time architecture for time-aware agents.

This paper describes the specification and implementation of a new three-layer time-aware agent architecture. This architecture is designed for applications and environments where societies of humans and agents play equally active roles, but interact and operate in completely different time frames. The architecture consists of three layers: the April real-time run-time (ART) layer, the time aware layer (TAL), and the application agents layer (AAL). The ART layer forms the underlying real-time agent platform. An original online, real-time, dynamic priority-based scheduling algorithm is described for scheduling the computation time of agent processes, and it is shown that the algorithm's O(n) complexity and scalable performance are sufficient for application in real-time domains. The TAL layer forms an abstraction layer through which human and agent interactions are temporally unified, that is, handled in a common way irrespective of their temporal representation and scale. A novel O(n2) interaction scheduling algorithm is described for predicting and guaranteeing interactions' initiation and completion times. The time-aware predicting component of a workflow management system is also presented as an instance of the AAL layer. The described time-aware architecture addresses two key challenges in enabling agents to be effectively configured and applied in environments where humans and agents play equally active roles. It provides flexibility and adaptability in its real-time mechanisms while placing them under direct agent control, and it temporally unifies human and agent interactions.

Greek versions of the Oswestry and Roland-Morris Disability Questionnaires.

Disability questionnaires are increasingly used for clinical assessment, outcome measurement of treatment and research methodology of low back pain. Their use in different countries and cultural groups must follow certain guidelines for translation and cross-cultural adaptation. The translation of such an instrument must be tested for its reliability and validity to be applied and to allow comparability of data. The Oswestry Disability Index and the Roland-Morris Disability Questionnaire are two disability questionnaires most commonly used as outcome measures in patients with low back pain. The two questionnaires were translated for use with the Greek population, were back translated and tested, and became available in a final version. The Greek versions of the Oswestry Disability Index and the Roland-Morris Disability Questionnaire were tested in 697 patients with low back pain. Internal consistency reliability for the Greek translation of the Oswestry Disability Index and the Roland-Morris Disability Questionnaire reached a Cronbach's alpha coefficient of 0.833 and 0.885 respectively. Face validity and content validity were ensured. Concurrent validity was assessed using a six-point pain scale as a criterion. The correlation of both scales was significant. The Greek translation of these disability questionnaires provided reliable and valid instruments for the evaluation of Greek-speaking patients with low back pain.