• Title/Summary/Keyword: Mental workload

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The study of the relationship between the similarity of cognitive map and the mental workload (인지지도 유사도와 정신적 작업부하와의 관계에 대한 연구)

  • Yu, Seung-Dong;Park, Peom
    • Journal of the Ergonomics Society of Korea
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    • v.21 no.3
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    • pp.47-58
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    • 2002
  • The similarity of shape of shape of interface between human cognitive map and real product is the important factor to determine the human performance. Nevertheless, the degree of similarity between these has not been defined quantitatively in recent studies. Therefore, in this study, the cognitive map and the mental workload were measured by SMM(Sketch Map Method) and RNASA-TLX(Revision of NASA-Task Load Index). And the numerical expression of the accuracy point was suggested for the quantitative calculation of relative positional similarity between cognitive map and real product. In the experiment, nine subjects were participated and two kinds of vehicles were used. Mental workload was mental workload was measured immediately after the road test. The result of analysis on the relationship between accuracy and mental workload shows that the negative correlation exists on each vehicle, and the lower score of mental workloads id measured on the vehicle that has the higher score of accuracy between two vehicles.

A Comparison of Subjective Mental Workload Measures in Driving Contexts

  • Kim, Ji Yeon;Ji, Yong Gu
    • Journal of the Ergonomics Society of Korea
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    • v.32 no.2
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    • pp.167-177
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    • 2013
  • Objective: This study aims to compare the usefulness of subjective measures which are comprised of existing methods like NASA-TLX, Bedford-scale and ZEIS and newly developed method like DALI in measuring drivers' mental workload in terms of validity, sensitivity and diagnosticity. Background: Nowadays, with the development of intelligent vehicle and HMI, mental workload of driver has become more and more important. For this reason, the studies on drivers' mental workload about driving situation and the use of information technology equipment such as mobile phones and navigations were conducted intensively. However, the studies on measuring drivers' mental workload were rarely conducted. Moreover, most of studies on comparison of subjective measures were used with performance based measure. However, performance based measures can cause distraction effect with subjective measures. Method: Participants (N=19) were engaged in a driving simulation experiment in 2 driving contexts (downtown driving and highway driving context). The experiment has 2 sessions according to driving contexts. The level of difficulties by driving contexts were adjusted according to existence of intersections, traffic signs and signals, billboards and the number of doublings. Moreover, as criteria of concurrent validity and sensitivity, the EEG data were recorded before and during the sessions. Results: The results indicated that all subjective methods were correlates with EEG in high-way driving. On the contrary to this, in downtown driving, all subjective methods were not correlates with EEG. In terms of sensitivity, multi-dimensional scales (NASA-TLX, DALI) were the only ones to identify differences between high way and downtown driving. Finally, in terms of diagnosticity, DALI was the most suitable method for evaluating drivers' mental workload in driving context. Conclusion: The DALI as newly developed method dedicated to evaluate driver's mental workload was superior in terms of sensitivity and diagnosticity. However, researchers should consider the characteristics of each subjective method synthetically according to research objective by selecting the method in subjective measures. Application: The results of this study could be applied to the intelligent vehicle and next generation of HMI design to decrease mental workload of driver and for the development of new subjective method in vehicle domain.

An Evaluation of the Operator Mental Workload of Advanced Control Facilities in Korea Next Generation Reactor (차세대 원자력 발전소 첨단 제어설비에 의한 운전원의 정신적 작업부하 평가)

  • Byun, Seong Nam;Choi, Seong Nam
    • Journal of Korean Institute of Industrial Engineers
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    • v.28 no.2
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    • pp.178-186
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    • 2002
  • The objective of this study is to evaluate impact of computer-based man-machine interfaces of Korea Next Generation Reactor (KNGR) on the operator mental workload. Empirical experiments were conducted to measure the operator mental workloads of KNGR and Yong-Gwang Unit 3 and 4, respectively. A comparison analysis based on a NASA TLX revealed that Yong-Gwang Unit 3 and 4 were superior to KNGR in terms of the mental workload. Post-hoc analyses showed that the mental workload of senior reactor operators was significantly higher than those of reactor and turbine operators, regardless of plant types. The implications of the findings were discussed in detail.

Development of Real-Time Mental Work Load Measurement System using Heart Rate Variability base on Personal Computer (심박변화율을 이용한 PC 기반 실시간 정신작업부하 측정시스템 개발)

  • 고한우;윤용현;양희경;김동윤
    • Science of Emotion and Sensibility
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    • v.4 no.1
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    • pp.1-5
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    • 2001
  • The evaluation of mental workload is measured by subjective ratings, physiological signals. It takes long time to analysis the measured signals and is very tedious and time-consumming work. Therefore, to evaluate the affect of workload effectively, real-time measurement system is required. In this paper, real-time mental workload measurement system using cardiac autonomic indiced which reflect well the mental workload was developed and evaluated. Analyzed indices were HR, IBI, Lorentz plot, CSI, CVI, and LF/HF ratio of heart rate variability. The system was applied to evaluate the affect of arithmetic task and showed good results. This system was consisted of ECG amplifier, A/D converter, and personal computer, and algorithm was implemented using LabVIEW.

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A study on the relationship between the time for a driver implement driving secondary task and mental workload due to the speed changes in driving simulation. (시뮬레이터 환경에서 속도변화에 따른 운전자의 이차과제 수행시간과 정신적 부하와의 관계에 대한 연구)

  • Son, Je-Sung;Yu, Seung-Dong;Kim, Jin-Ho;Park, Peom
    • Proceedings of the Korean Society for Emotion and Sensibility Conference
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    • 2002.11a
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    • pp.114-119
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    • 2002
  • In driving situation, driver’s performance can be divided into primary task and secondary task. Many studies of primary task have been in progress, but those of secondary task are not implemented sufficiently. However, the driver’s error is greatly influenced by secondary task. In this study, an experiment was assessed to determine the relationship between the driver's operation time for the secondary task and mental workload due to speed changes in a driving simulation. The time to perform the secondary task was analyzed with Fitts’ Law, and mental workload was analyzed with RNASA-TLX(Revision of NASA-Task Load Index). The results has showed that the higher speed, the weaker the explanation by the use of Fitts' Law and the result of analyzing mental workload using RNASA-TLX was similar to the result of Fitts’ Law.

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Physiological Data Monitoring of Physical Exertion of Construction Workers Using Exoskeleton in Varied Temperatures

  • Ibrahim, Abdullahi;Okpala, Ifeanyi;Nnaji, Chukwuma
    • International conference on construction engineering and project management
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    • 2022.06a
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    • pp.1242-1242
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    • 2022
  • Annually, several construction workers fall ill, are injured, or die due to heat-related exposure. The prevalence of work-related heat illness may rise and become an issue for workers operating in temperate climates, given the increase in frequency and intensity of heatwaves in the US. An increase in temperature negatively impacts physical exertion levels and mental state, thereby increasing the potential of accidents on the job site. To reduce the impact of heat stress on workers, it is critical to develop and implement measures for monitoring physical exertion levels and mental state in hot conditions. For this, limited studies have evaluated the utility of wearable biosensors in measuring physical exertion and mental workload in hot conditions. In addition, most studies focus solely on male participants, with little to no reference to female workers who may be exposed to greater heat stress risk. Therefore, this study aims to develop a process for objective and continuous assessment of worker physical exertion and mental workload using wearable biosensors. Physiological data were collected from eight (four male and four female) participants performing a simulated drilling task at 92oF and about 50% humidity level. After removing signal artifacts from the data using multiple filtering processes, the data was compared to a perceived muscle exertion scale and mental workload scale. Results indicate that biosensors' features can effectively detect the change in worker physical and mental state in hot conditions. Therefore, wearable biosensors provide a feasible and effective opportunity to continuously assess worker physical exertion and mental workload.

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Comparative Study of Subjective Mental Workload Assessment Techniques for the Evaluation of ITS-oriented Human-Machine Interface Systems (지능형 교통체계 기반 인간-기계 인터페이스 시스템 평가를 위한 정신적부하 측정방법의 비교 연구)

  • Cha, Doo-Won;Park, Peom
    • Journal of Korean Society of Transportation
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    • v.19 no.3
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    • pp.45-58
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    • 2001
  • Subjective mental workload assessment technique becomes a standard human factors and human-machine interface evaluation tool for the evaluation of ITS(Intelligent Transport Systems)-oriented information systems as well as the drivers visual activity analysis, physiological indices(GSR, EEG, ECG, etc.), secondary task performance, reaction time. vehicle control parameters(speed, steering behavior, accelerator control) that are widely applied for transportation and vehicle systems to evaluate the safety, to decide the system or design alternatives, and to establish the design guidelines. This paper reviewed and compared the most globally employed four mental workload assessment techniques that have been designed for the use of various human-machine systems and ITS-oriented in-vehicle information systems. NASA-TLX(National Aeronautics and Space Administration-Task Load Index). SWAT(Subjective Workload Assessment Technique), MCH(Modified Cooper-Harper) scale, and recently developed RNASA-TLX(Revision of NASA-TH) were compared in terms of sensitivity and subjective evaluations to derive the human-machine interface evaluation guidelines for the application of ITS-oriented in-vehicle information systems. Then, experiment results supported that RNASA-TLX is the prospective tool for the mental workload assessment of ITS-oriented in-vehicle information systems.

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Simulator-Based Mental Workload Assessment of the In-Vehicle Navigation System Driver Using Revision of NASA-TLX (항법장치 simulator 기반의 RNASA-TLX 를 이용한 항법장치 운전자 mental workload 평가에 관한 연구)

  • Cha, Doo-Won;Park, Peom
    • IE interfaces
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    • v.10 no.1
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    • pp.145-154
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    • 1997
  • In developing the HMI(Human-Machine Interface) evaluation system for the IVNS(In-Vehicle Navigation System), design guidelines and evaluation methods are the most crucial problems for its use and efficiency. As the part of this system, focused on the final product of the database, subjective mental workload assessment is seriously considered to evaluate the driver's own driving task using the IVNS. This paper suggests the methodology for the ergonomic assessment of the IVNS that corresponds to the subjective measurement of the driver's mental workload by rating his or her own driving task. For this approach, Revision of NASA-Task Load Index(RNASA-TLX) was developed which translated and revised the version of NASA-TLX that is generally accepted an efficient and powerful method for evaluating the in-vehicle information systems. To verify the RNASA-TLX, an experiment was conducted in a real road situation, because the result of the laboratory approach is uncertain and has the differences from the real road test.

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Measuring Workload of Home Visit Care Activities Using Relative Values (방문요양 행위 업무량의 상대적 가치 측정)

  • Han, Seong-Ok;Park, Eun-Cheol;Kang, Dae-Ryong;Kang, Im-Ok
    • Journal of Preventive Medicine and Public Health
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    • v.41 no.5
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    • pp.331-338
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    • 2008
  • Objectives : The purpose of this study was to measure the workload of home visit care activities and their relative values. This study examined also factors that affect the workload of home visit care activities. Methods : The participants of this study were 126 home-helpers of 50 home visit care agencies at the 2nd Long-term Care Insurance Demonstration Project. The workload of home visit care activities was divided into total work and four dimensions ; physical efforts, mental efforts, stress and time. Home visit care activities consisted of four categories with 24 items. We used magnitude estimation method to measure their relative values of the four dimensions. The participants answered the relative values of each activities based on the reference service. We used the activity for supporting their elderly's evacuation as the reference service. Results : Most of the respondents were over 40 years old female. They consumed most their time supporting elderly's going out. They consumed their highest physical, mental efforts, and stress for activities of coping with emergency situation. The Pearson correlation coefficients showed significant relationships between workload and each dimensions. This study showed that all four dimensions are statistically significant predictors of workload of home visit care activities. Also, we found that the home-helper's career affects the workload of home visit care activities. Conclusions : The workload of home visit care activities could be explained by physical efforts, mental efforts, stress and time.

Development of a Workload Assessment Model for Overhead Crane Operation (천장 크레인 운전 작업부하 평가모델 개발)

  • Kwon, O-Chae;Lee, Sang-Ki;Cho, Young-Seok;Park, Jung-Chul;Jung, Ki-Hyo;You, Hee-Cheon;Han, Sung-H.
    • Journal of the Ergonomics Society of Korea
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    • v.26 no.2
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    • pp.45-59
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    • 2007
  • The operating tasks of overhead crane have caused undue stress to the operators from physical, mental, and environmental workload. Existing workload assessment models for musculoskeletal disorders such as OWAS, RULA, and QEC have limited applicability to the crane operating tasks because they focus mainly on physical factors and do not consider the relative importance of each factor. The present study was to develop a workload assessment model customized to overhead crane operation, following a systematic process: (1) analyzing task characteristics, (2) selecting workload factors, (3) developing assessment methods, (4) establishing action levels, and (5) computerizing the assessment model. Based on literature review, worksite survey, and focus group interview, 4 physical factors (awkward posture, static posture, repetitive motion, and excessive force), 6 mental factors (visual demand, auditory demand, task complexity and difficulty, time urgency, work schedule related stress, and safety related stress), and 4 environmental factors (noise, vibration, dust, and temperature) were selected and their rating scales and relative weights were determined. Then, based on the workload assessment results of 8 overhead cranes operated at different workplaces, the action levels of each factor category were established. Finally, the crane operation assessment model was computerized for effective analysis and report preparation. The present approach is applicable to develop a customized workload assessment model for an operating task under consideration.