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Based on previous research and properties of organizational memory, a conceptual model for navigation and retrieval functions in an Intranet portal organizational memory information system was proposed, and two human-centred features (memory structure map and history-based tool) were developed to support user's navigation and retrieval in a well-known organizational memory. To test two hypotheses concerning the validity of the conceptual model and two human-centred features, an experiment was conducted with 30 subjects. Testing of the two hypotheses indicated the following: (1) the memory structure map's users showed 29% better performance in navigation, and (2) the history-based tool's users outperformed by 34% in identifying information. The results of the study suggest that a conceptual model and two human-centred features could be used in an user-adaptive interface design to improve user's performance in an intranet portal organizational memory information system. [ABSTRACT FROM AUTHOR]

Background: Tube current is an important determinant of radiation dose and image quality in X-ray-based examination. The combined automatic tube current modulation technique (ATCM) enables automatic adjustment of the tube current in various planes (x-y and z) based on the size and attenuation of the body area scanned. Purpose: To compare image quality and radiation dose of the ATCM with those of a fixed tube current technique (FTC) in CT of the abdomen and pelvis performed with a 16-slice multidetector row CT. Material and Methods: We reviewed 100 patients in whom initial and follow-up CT of the abdomen and pelvis were performed with FTC and ATCM. All acquisition parameters were identical in both techniques except for tube current. We recorded objective image noise in liver parenchyma, subjective image noise and diagnostic acceptability by using a five-point scale, radiation dose, and body mass index (BMI, kg/m(2)). Data were analyzed with parametric and non-parametric statistical tests. Results: There was no significant difference in image noise and diagnostic acceptability between two techniques. All subjects had acceptable subjective image noise in both techniques. The significant reduction in radiation dose (45.25% reduction) was noted with combined ATCM (P < 0.001). There was a significant linear statistical correlation between BMI and dose reduction (r = -0.78, P < 0.05). Conclusion: The ATCM for CT of the abdomen and pelvis substantially reduced radiation dose while maintaining diagnostic image quality. Patients with lower BMI showed more reduction in radiation dose. [ABSTRACT FROM AUTHOR]