Research on cognitive load evaluation with subjective method in manual assembly

Subjective scales have different kinds of applicability in diverse fields.This study intends to implement a quantitative approach to determine the applicability of subjective scales in manual as-sembly work and evaluate the cognitive load of assembly workers.A multi-scale research paradigm based on subjective evaluation method is proposed.Three typical task stages are extracted from the process of assembly work.The National Aeronautics and Space Administration Task Load Index(NASA-TLX)scale,PAAS scale and Workload Profile Index Ratings(WP)scale are selected for the design of 3×3 multi-factor mixed experiment.The power spectrum density(PSD)characteris-tics of electroencephalogram(EEG)are utilized to identify the difficulty levels of the three task sta-ges.The relevant indicators of scale applicability are assessed.The results show that in terms of sensitivity,NASA-TLX scale reaches the highest sensitivity(F=999.137,P=0<0.05).In terms of validity,NASA-TLX scale possesses the best concurrent validity(P=0.0255<0.05).In terms of diagnosticity,NASA-TLX scale based on 6 dimensions takes on the best diagnostic performance.In terms of subject acceptability,WP scale performs the worst.According to the analytic hierarchy process(AHP)model,the applicability scores of NASA-TLX scale,PAAS scale and WP scale are determined as 3,2.55 and 1.6714,respectively.Therefore,NASA-TLX scale is regarded as the most suitable subjective evaluation questionnaire for assembly workers,which is also an effective quantitative evaluation method for the cognitive load of assembly workers.

Scale Consistency Quantification for Subjective Evaluation of Vehicle Dynamics

The subjective evaluation of vehicle dynamics performance is widely applied in different stages of vehicle development.However,the rating result has frequently been challenged because it is easily affected by various subjective and objective factors.Currently,there is no suitable index for determining evaluator’s consistency when performing a subjective evalua-tion of vehicle dynamics.This evaluation is quite unique,with limited samples,multiple indices,and poor repeatability,in addition to being stratified and two dimensional.The cross-grouped factor analysis(CFA)method is proposed to identify the scale for a subjective evaluation and to quantify its consistency.An application case study revealed that the proposed method is effective.

Objective Quantification of Small Motor Sound Quality Based on Psychoacoustic Metrics

With the widespread application of electrification and intelligence of automobiles,the number of electric devices with small DC motors in automobiles has gradually increased,and the in-terior of electric vehicles is quieter.The sound quality(SQ)of small motor directly affects the pas-senger experience.Therefore,the research on the SQ of small motor is of great significance.In this paper,the objective quantification of small motor sound quality was investigated based on tradi-tional psychoacoustic metrics.The time-frequency characteristics of sound signal was analyzed to quantify the subjective perception caused by the sound of small motor.And a new psychoacoustic metrics of objective evaluation which were suitable for small motor SQ evaluation were proposed,namely specific loudness energy(SLE),specific prominence ratio index(SPRI),relative pitch exceedance(RPE)and tremolo index(TI).Then,two objective evaluation models of small motor SQ were established to characterize the multi-dimensional subjective perception attributes by using multiple linear regression(MLR)and support vector regression(SVR)respectively,which can be used for the prediction and evaluation of the small motor SQ.The results show that the prediction accuracy of the model established by SVR method was higher than that of MLR,and SVR has stronger robustness.The objective evaluation model of small motors SQ established in this study is of great importance for improving the sound quality of small motors.

Design and Development of Garment Fabric Database Management System

The main performance characteristics of garment fabric are analyzed and extracted,which include physical characteristics,appearance characteristics and subjective evaluation characteristics.A calculating model of fabric’s subjective evaluation is provided,which can be adjusted as the data increasing.The database system of garment fabric is analyzed,and then function design,concept design and logic design are carried out.The user interface(UI)design of garment fabric database system is described.The system can not only serve the fabric management and customization of garment enterprises,but also serve the teaching work of colleges and universities,because it is rich in information and convenient.It is of great significance to digital construction in the clothing field.

Research on Teaching Evaluation of Courses Based on Computer System Ability Training

The courses based on computer system ability training has its particularity of training objective.To achieve objective feedback of teaching,a multi-subject and multi-dimensional hierarchical teaching evaluation system is proposed based on the analysis of computer system ability training objectives.Then,the teaching content,implementation,learning experience and teaching effect were evaluated by supervisors,colleague teachers and students.Finally,the multi-dimensional evaluation results show that the evaluation system proposed is effective and provides a reference for teaching evaluation.

Impacts of corridor design:An investigation on occupant perception of corridor forms in elderly facilities

The study addresses the issue of monotonous and lengthy corridors with a single spatial form commonly found in Chinese elderly facilities.We aim to assess the influence of the built spatial environment on the emotions of the elderly quantitatively.To do this,Virtual Reality(VR)technology was employed to construct a digital twin model featuring three corridor forms:straight,arc,and folded,respectively.Forty participants experienced walking in each corridor form for 144 s,while electroencephalogram(EEG)data and subjective questionnaires were collected to explore the psychological and physiological effects caused by different corridors.The results of the questionnaire indicate that arc corridor yielded the highest satisfaction,followed by straight corridor,and the satisfaction for folded corridor is the lowest.EEG results show that folded corridor has 26.0%higher average power than arc corridor and 6.6%higher than straight corridor.The participants consume less energy and are more satisfied in arc corridor,compared to straight and folded corridors.The results establish a correlation between spatial form and occupant perception,suggesting that moderate spatial variations contribute to a better experience of the elderly.Moreover,this study provides quantitative cross-referencing information to optimize the design methods of public space in elderly facilities.

Research on emotional space for movie and TV drama videos

Emotional space refers to a multi-dimensional emotional model that describes a group of subjective feelings or emotions. Since the existing discrete emotional space is mainly aimed at human’s primary emotions, it cannot describe the complex emotions evoked when watching movies. In order to solve this problem, an emotional fusion space for videos was constructed by selecting movies and TV dramas with rich emotional semantics as the research objects. Firstly, emotional words based on movie and TV drama videos are acquired and analyzed by using subjective evaluation and semantic analysis methods. Then, the emotional word vectors obtained from the above analysis are fused, reduced dimension by t-distributed stochastic neighbor embedding(t-SNE) algorithm, and clustered by bisecting K-means clustering algorithm to get a discrete emotional space for movie and TV drama videos. This emotional fusion space can obtain different categories by changing the value of the emotion classification number without re-labeling and calculation.

Comparison of Color and Grayscale Simulated TV-Graphics in Rendezvous and Docking

Subjective evaluation is one of the most important methods of assessing the fidelity of a virtual dynamic scene,whose results could be seen as a reference to improve a rendering method.In the present study,we apply a rendering method to the color rendezvous and docking(RVD) scene,where one shadow algorithm and three tone mapping operator algorithms are used to process the scene based on the distance between two spacecrafts.The grayscale RVD scene is transformed from the color RVD scene,and each RVD scene is desired to make comparisons with the real RVD-video recorded in SZ-10 mission.In addition,we perform an evaluation on 36 subjects to compare the results.The results show that shadow effects have important roles in RVD virtual scenes,where they enhance the sense of realism and immersion.Shadows,high brightness,contrast and luminance are highly correlated with the overall preference,and the grayscale scene receives better evaluations than the color scene.The analysis of these conclusions is vital for improving the algorithms used to render color virtual space scenes when virtual scenes for astronaut training in Chinese space station mission are prepared.