Task analysis approach based on perceptual control theory

Based on perceptual control theory,a task analysis approach is proposed to describe more accurately user tasks in dynamic environments,which is of more powerful and flexible descriptive ability. Theoretically,a task meta model is established to describe the interactive process in an individual,dynamic,and flexible way.Methodologically,an implementation framework is illustrated to map the user-oriented description into implementation-oriented models,which will be as a technical tool to transform from a task model to a user interface prototype.

A Study on the Task Analysis and Performance Evaluation of Carved Lacquer Craft Inheritors in Novice Stage

The carved lacquer craft,a gem of traditional Chinese crafts,boasts a history of over 2,000 years and features craftsmanship of a superior order.This study attempts to investigate the typical tasks and learning result evaluation of carved lacquer apprentices at the novice stage by the method of qualitative research with 11 carved lacquer craft inheritors of a studio of a carved lacquer master.It is discovered that the design of carved lacquer draft sketches,the design of carved lacquer patterns,and the making and use of carved lacquer tools are typical tasks of novice apprentices,while the modeling and aesthetics of works,carving skills,and the level of interaction with the carved lacquer community are important criteria for evaluating the development of the skills of novice apprentices.

A method for measuring pilot workload based on task analysis

This paper presents a method for measuring pilot workload based on task analysis in order that the cockpit can be designed more reasonably. In addition, a prototype system is developed to use this method for the assessment of pilot workload. The method breaks the pilot's mission into several phases, segments, functions and tasks. And break pilot workload into 6 components using Wickens' 'multi-resource theory', which are vision(V), vision goggles(G), auditory sensation(A), cognitive activity(C), psychomotor activity(P) and kinesthesis(K). All missions consist of those tasks and each task have 6 workload components. The workload components for each task have been acquired by a study on many pilots, so workload can be assessed. A mission analysis database is built, and the prototype system can simulate pilot's flight process and evaluate workload.

Identification and Analysis of Multi-tasking Product Information Search Sessions with Query Logs

Purpose： This research aims to identify product search tasks in online shopplng ana analyze the characteristics of consumer multi-tasking search sessions. Design/methodology/approach： The experimental dataset contains 8,949 queries of 582 users from 3,483 search sessions. A sequential comparison of the Jaccard similarity coefficient between two adjacent search queries and hierarchical clustering of queries is used to identify search tasks. Findings： （1） Users issued a similar number of queries （1.43 to 1.47） with similar lengths （7.3-7.6 characters） per task in mono-tasking and multi-tasking sessions, and （2） Users spent more time on average in sessions with more tasks, but spent less time for each task when the number of tasks increased in a session. Research limitations： The task identification method that relies only on query terms does not completely reflect the complex nature of consumer shopping behavior.Practical implications： These results provide an exploratory understanding of the relationships among multiple shopping tasks, and can be useful for product recommendation and shopping task prediction. Originality/value： The originality of this research is its use of query clustering with online shopping task identification and analysis, and the analysis of product search session characteristics.

A User-Friendly SSVEP-Based BCI Using Imperceptible Phase-Coded Flickers at 60Hz

A brain-computer interface(BCI)system based on steady-state visual evoked potentials(SSVEP)was developed by four-class phase-coded stimuli.SSVEPs elicited by flickers at 60Hz,which is higher than the critical fusion frequency(CFF),were compared with those at 15Hz and 30Hz.SSVEP components in electroencephalogram(EEG)were detected using task related component analysis(TRCA)method.Offline analysis with 17 subjects indicated that the highest information transfer rate(ITR)was 29.80±4.65bpm with 0.5s data length for 60Hz and the classification accuracy was 70.07±4.15%.The online BCI system reached an averaged classification accuracy of 87.75±3.50%at 60Hz with 4s,resulting in an ITR of 16.73±1.63bpm.In particular,the maximum ITR for a subject was 80bpm with 0.5s at 60Hz.Although the BCI performance of 60Hz was lower than that of 15Hz and 30Hz,the results of the behavioral test indicated that,with no perception of flicker,the BCI system with 60Hz was more comfortable to use than 15Hz and 30Hz.Correlation analysis revealed that SSVEP with higher signal-to-noise ratio(SNR)corresponded to better classification performance and the improvement in comfortableness was accompanied by a decrease in performance.This study demonstrates the feasibility and potential of a user-friendly SSVEP-based BCI using imperceptible flickers.

Moxibustion modulates working memory in patients with amnestic mild cognitive impairment:a functional magnetic resonance imaging study

OBJECTIVE:To investigate the correlation between changes in brain activity associated with working memory and assessment scales of memory scores in amnestic mild cognitive impairment(aMCI)before and after moxibustion therapy.METHODS:aMCI patients were randomized into the moxibustion treatment(MT)group and the placebo moxibustion(PM)group.Each group received either moxibustion therapy or a placebo moxibustion for eight weeks.Neuropsychological performance and functional brain responses to a working memory task were assessed at baseline and at the end of treatment.Memory function was evaluated individually by the Rivermead behavioral memory test(RBMT),and working memory was assessed by the N-back task.RESULTS:Compared with the PM group,RBMT score changes were significant(P<0.05).In the MT group,the accuracy of the N-back texts increased compared with those before the intervention.After moxibustion intervention,the right insula,postcentral gyrus,precentral gyrus,superior temporal gyrus,thalamus,lingual gyrus,calcarine sulcus,posterior cingulate gyrus,middle frontal gyrus and anterior frontal gyrus were significantly activated(P=0.01,Cluster-level Family-Wise Error=0.05).Pearson correlation analysis showed that the insula,lingual gyrus and posterior cingulate gyrus were associated with changes in N-back score.Spearman correlation analysis showed that the postcentral gyrus,superior temporal gyrus,thalamus,lingual gyrus,and posterior cingulate gyrus were correlated with RBMT score changes.CONCLUSION:Moxibustion treatment improved memory in aMCI patients and was associated with the activation of the brain region of the insula,lingual gyrus,posterior cingulate gyrus,postcentral gyrus,superior temporal gyrus,and thalamus,which may be an important mechanism by which moxibustion improves the memory function.