• Journal of Biomedical Engineering Research
• /
• v.43 no.1
• /
• pp.52-60
• /
• 2022

Purpose: For now, cognitive load is assessed based on survey-based methods, which can be difficult to track the amount of cognitive load in real-time. In this study, we investigated the difference in electrophysiological activation due to different levels of cognitive load not only at sensor-level but also at source-level using electroencephalogram that might be potentially used for quantitative cognitive load evaluation. Materials and Methods: In this study, ten healthy subjects (mean age 24.3 ± 2.1, three female) participated the experiment. All participants performed 4 sessions of n-back task in different difficulties: 0-, 1-, 2-, and 3-back during electroencephalogram recording. For sensor-level analysis, we calculated the event-related potential and event-related spectral perturbation while low resolution brain electromagnetic tomography (LORETA) to estimate the source activation. Each result was compared between different workload conditions using statistical analysis. Results: Statistical results revealed that the accuracy of the task performance was significantly different between different cognitive loads (p = 0.018). The post-hoc analysis confirmed that the accuracy of the 3-back task was significantly decreased compared to 1-back condition (p = 0.018), but not with 2-back condition (p = 0.180). ERP results showed that P300 target amplitude between 1-back and 3-back had a marginal difference in Cz (p = 0.059) and Pz(p = 0.093). A significant inhibition in Cz high-beta activation (p = 0.017) and decrease in source activation of right parahippocampal gyrus was found in 3-back condition compared to 1-back condition (p < 0.05). Conclusion: In this study, we compared the sensor- and source-level differences in electroencephalogram between different levels of cognitive load, that were found to be in line with the previous reports related to cognitive load evaluation. We expect that the outcome of the current study can be used as a feature to establish a quantitative cognitive load assessment system.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.13 no.9
• /
• pp.3999-4008
• /
• 2012

This study investigated the symptoms of work-related musculoskeletal disorder(WMSDs) for physical therapists who have different work duties. We analyzed the symptoms in the musculoskeletal system and the degree of work-harmfulness by the survey of the symptom in the musculoskeletal system and rapid upper limb assessment(RULA) for pain control group(n=56), adult exercise group(n=53), and pediatric exercise group(n=22). As a result, 69.6% of the pain control group, 84.9% of the adult exercise group, 81.8% of the pediatric exercise group show the observable symptom. The adult exercise group has the biggest work load per hour in the final wrist & arm score of the ergonomic risk assessment using RULA. The action level of the pain control group is $3.0{\pm}0.9$; the Action Level of adult exercise group is $3.3{\pm}0.6$; the Action Level of the pediatric exercise group is $3.2{\pm}0.8$, and so it is shown that the adult exercise group has a problem of working posture. It is considered that devices and education system for preventing from WMSDs should come into wide use.

• Korean Journal of Community Nutrition
• /
• v.17 no.5
• /
• pp.652-663
• /
• 2012

The purpose of this study was to assess the physical activity level of Korean farmers to establish estimated energy requirements during the off-season. Subjects were 90 healthy males (n = 25) and females (n = 65). Body weight, height and body fat and muscles of subjects were measured. The prevalence of obesity among farmers was 56.7% according to the BMI. The farmers spent about 18 hours 7 minutes (75.5%) in sleeping and resting. The farmers spent about 19 hours 56 minutes (83.1%) out of 24 hours (one day) in "sedentary activities" and spent about 3 hours 56 minutes (16.4%) in "light activities". Physical activity level (PAL, activity coefficient) of female farmers was 1.42 which was not significantly higher than that (1.37) of male farmers. Estimated energy requirements (EER) for farmers who were different in age groups and gender were calculated. For example, the EERs for male and female farmers were 2190 kcal/day and 1712 kcal/day, respectively. The daily energy intakes of male and female farmers were 1803 kcal/day and 1610 kcal/day, respectively. The EER of male farmers was 2190 kcal/day which was significantly higher than that (1803 kcal/day) of the recommended daily energy intake of male farmers. The results of this study suggest that estimated EER of farmers should be modified according to seasonal workload and energy balance of farmers should be evaluated to prevent obesity.

• Journal of the Ergonomics Society of Korea
• /
• v.24 no.3
• /
• pp.11-27
• /
• 2005

The objectives of this study are to analyze representative wrist postures while using hand tools and parts at general assembly processes, to evaluate perceived discomfort on the wrist when external loads are present, and to suggest an evaluation and prediction model of perceived discomfort. Sixteen subjects participated in an experiment to appraise perceived discomfort. Three types of the wrist postures with five levels of non-neutralities were analyzed when five levels of external load were applied to each posture. The ANOVA results showed that the perceived discomfort of wrist postures was significantly affected by both the wrist posture and external load (p$<$0.001). It was also shown that some of the interactions between external loads and the wrist postures(Flexion/$Extension^*$Load, Flexion/$Extension^*$supination/pronation, ulnar/radial $deviation^*$supination/pronation) were significant(p$<$0.001). The result implies that a new posture classification scheme for workload assessment methods may be needed to reflect such effects of external load and wrist posture. A regression model of perceived discomfort was developed with respect to wrist posture and external load from the experimental data. A subsequent experiment revealed that the correlation coefficient between the predicted values of perceived discomfort from the model and the actual values obtained from the experiment was about 0.98. It is expected that the results help to properly estimate the body stress resulting from worker's postures and external loads and can be used as a valuable design guideline to analyze potential hazard of musculoskeletal diseases in industry.

• English Language & Literature Teaching
• /
• v.16 no.1
• /
• pp.259-281
• /
• 2009

The ICELT(In-Service Certificate in English Language Teaching) is a highly practical course-based English teacher education program which integrates classroom teaching and off-site teacher training. This case study analyzes the three-year implementation of the ICELT program in Korea and discusses its effects and the implications for improving the inservice English teacher education system. It has been found that the course participants were satisfied with the quality of its execution, thinking that it contributed to their professional development in the areas of teaching practice, methodology and language competence. The study has identified several success factors as shared program goals among the course participants, including systematic selection of course participants, well-qualified tutors and the proper provision of resources including syllabus, teaching materials and course assessment system. Nonetheless, it has been suggested that attention needs to be paid to generalized application of the ICELT for English teacher education due to the limitations such as the heavy workload caused by the program, lack of course participants' collaboration with other teachers at their schools and tutors' poor understanding of the Korean education context. Bearing this in mind, the implications for improving the inservice English teacher education system in Korea have been discussed. Finally, further studies have been suggested, which are concerned with in-depth investigation in exploring the division of roles between native English speaking tutors and Korean ones and the impact of the program on the sustainability of course participants' professional development and the impact on schools.

• Imaging Science in Dentistry
• /
• v.50 no.2
• /
• pp.81-92
• /
• 2020

Intelligent systems(i.e., artificial intelligence), particularly deep learning, are machines able to mimic the cognitive functions of humans to perform tasks of problem-solving and learning. This field deals with computational models that can think and act intelligently, like the human brain, and construct algorithms that can learn from data to make predictions. Artificial intelligence is becoming important in radiology due to its ability to detect abnormalities in radiographic images that are unnoticed by the naked human eye. These systems have reduced radiologists' workload by rapidly recording and presenting data, and thereby monitoring the treatment response with a reduced risk of cognitive bias. Intelligent systems have an important role to play and could be used by dentists as an adjunct to other imaging modalities in making appropriate diagnoses and treatment plans. In the field of maxillofacial radiology, these systems have shown promise for the interpretation of complex images, accurate localization of landmarks, characterization of bone architecture, estimation of oral cancer risk, and the assessment of metastatic lymph nodes, periapical pathologies, and maxillary sinus pathologies. This review discusses the clinical applications and scope of intelligent systems such as machine learning, artificial intelligence, and deep learning programs in maxillofacial imaging.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.48 no.11
• /
• pp.935-943
• /
• 2020

This paper presents a methodology for evaluating suitability of a manned-unmanned aerial vehicle team for a complicated mission. The study identified vehicle performance, equipment performance and level of autonomy as the key factors that affect the mission effectiveness. A manned and an unmanned aircraft were compared, and their performance was quantized in these respects. SEAD was chosen as a representative manned-unmanned team mission. The SEAD mission was broken down to a sequence of tasks. Mission experts evaluated the importance of each mark item for the mission legs. Combining the results showed proper type of aircraft for each leg depending on the complexity, safety, and importance of the task. Finally, the whole mission plan was laid out as a time-based sequence which alleviate pilot workload significantly.

• Journal of the Korean Society for Railway
• /
• v.12 no.5
• /
• pp.744-750
• /
• 2009

According to the result of related studies, the degradation of human performance has been revealed as one of the most significant causes resulting in the safety of any human-involved system. This means that preventing the occurrence of accidents/incidents through avoiding the degradation of human performance is prerequisite for their successive operation. To this end, it is necessary to develop a plausible tool to evaluate the complexity of a task, which has been known as one of the decisive factors affecting the human performance. For this reason, in this paper, the complexity of tasks to be conducted by KTX drivers was quantified by TACOM measure that is enable to quantify the complexity of proceduralized tasks being used in nuclear power plants. After that, TACOM scores about the tasks of KTX drivers were compared with NASA-TLX scores that are responsible for the level of a subjective workload to be felt by KTX drivers.

• Korean Journal of Community Nutrition
• /
• v.16 no.6
• /
• pp.751-761
• /
• 2011

The purpose of this study was to assess the physical activity level of Korean farmers to establish their estimated energy requirements during busy farming season. 113 farmers (mean age $51.9{\pm}7.2$ years, male 42, female 71) who own farmland area above 300 pyung participated in measurement of body weight and height and interviewing of one-day activity diaries. There was no significant difference in age, BMI between male and female. Obesity prevalence according to BMI among male and female farmers was 40.5% and 50.7% respectively. The farmers spent about 7 hours in sleeping and spent about 4 hours 35 minutes working on the farm and spent about 15 hours 30 minutes (64.6% of 24 hours) in "very light activities" and spent about 3 hours 31 minutes (14.7%) in "light activities". Physical activity level (PAL, activity coefficient) of male farmers was 2.63 which was significantly higher than that (2.19) of female farmers (p < 0.05). Estimated energy requirements (EER) for farmers who were different in age and gender were suggested. For example, the estimated energy requirements for male and female farmers were 3058 kcal/day and 2279 kcal/day, respectively. The results of this study suggest that estimated energy requirements (EER) of farmers should be differentiated according to seasonal workload and energy balance of farmers should be evaluated to prevent obesity.

• Convergence Security Journal
• /
• v.15 no.5
• /
• pp.47-52
• /
• 2015

The aim of this study is to suggest the effective protocol to manage the obese children using the data based on PAPS(Physical Activity Promotion System). In the school, there are a lot of efforts for the management of increasing obese children through the data obtained from PAPS which is conducted annually includes the assessment of obesity. But the follow-up of obese children was not effective due to the workload of teachers and the lack of available manpower. For more active and systematic management, the combination of a smart device transfer in the existing ways for facilitating access to the information is more effective. The information of obese children such as fitness, health, and obesity automatically will be sent in web-PAPS, And when personalized exercise prescription, proper nutrition education for obesity are shared with their parent, it will be more effective in weight management.