Cognitive and Driving Performance of Young and Elderly Driver’s on Unexpected Event

Murali Subramaniyam1,Se Jin Park,Hyun Kyoon Lim,Dong Gyun Kim,Heeran Lee,Myung Kug Moon 대한인간공학회 2013 대한인간공학회 학술대회논문집 Vol.2013 No.10

Objective: The cognitive and driving performance of both young adult drivers and elderly drivers during unexpected driving situations were compared and analyzed, using a graphic driving simulator. Background: An unexpected event described as while driving, the lead-vehicle stops unexpectedly the participant vehicle needs to apply last minute braking to avoid accident. The physiological stress and responses involved during unexpected event are studied very little. Aging makes people do less social, physical and psychological activities. Method: The cognitive parameters considered were percentage of relative beta spectrum power, measured from Fz and O2 area using electroencephalogram, and R-R interval measured using an electrocardiogram. The driving performances measured from the driving simulator were: crash rate, inter vehicle distance, reaction time, full braking time and participant vehicle approaching velocity to the unexpected event. There were two groups of participants employed in this study. The younger group 26.3±2.0 years of age and older group were 65.6±5.0 years of age. Nineteen participants were assigned to each group, and these groups included only male drivers. All the participants were experienced two unexpected driving situations, one while driving at 70 km/h and another at 90 km/h. Results: Compared with young drivers, elderly drivers showed longer and greater cognitive stain during unexpected events. Electroencephalogram analysis showed significant difference (p < 0.05) in relative beta spectrum power before and after the unexpected event, and also a significant difference (p < 0.05) between driving situations. Young drivers reacted quicker to the sudden event than elderly drivers. Therefore, the crash rates were higher by the elderly drivers in both driving situations. Conclusion: Elderly drivers showed the different physiological responses under unexpected events and may need different guides for the safer driving.

Seating comfort evaluation of child safety seats with a child manikin for making new standard

( Murali Subramaniyam ),( Seung Nam Min ),( Se Jin Park ) 한국감성과학회 2013 추계학술대회 Vol.2013 No.-

Efficiency evaluation of micro factory for micro pump manufacture

Murali Subramaniyam,박상호,최성일,송준엽,박종권 대한기계학회 2009 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.23 No.2

The micro factory, a miniature manufacturing system, is a means of achieving higher throughput with minimal space, and minimal consumption of energy and resources by downsizing of production processes. Even though, a micro factory is able to perform whole manufacturing processes like the macro factory, the possibility of improving its manufacturing efficiency has not been considered enough. In this paper, an efficiency index is proposed to calculate the efficiency of the micro factory to manufacture a micro pump. The efficiency index has been proposed based on efficiency definition with input and output parameters of the system. Input parameters include cost of system, processing time and energy. Output parameters represent number of product manufactured from the microfactory. Cost of the system has been categorized by micro assembly machine cost, cost of resources, manipulators’ cost, manufacturing space value, and human operators. Processing time has been categorized by assembly time and material handling time.

Analysis of five- and six-machine micro-factory layouts for micro-pump productivity improvement

Murali Subramaniyam,박상호,박종권 대한기계학회 2010 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.24 No.11

In the present study, analyses of two micro-factory layouts were performed to improve its micro-pump production rate and efficiency. For the purpose of the analysis, the two layouts, Layout A (existing) with five micro machines (including one micro milling machine)and Layout B (proposed) with six micro machines (including two micro milling machines), were constructed in the virtual environment. First, Layout A was simulated to predict the production time and to calculate the production rate and efficiency. The robot-arm waiting time, which was considered as the bottleneck, had a significant effect on the production rate. Second, to alleviate this bottleneck, we introduced,based on the robot-arm reach envelope concept, another micro milling machine to the Layout A, and named this new scheme Layout B. In the results of our analysis, Layout B improved the production rate by about 1.88 times and enhanced the efficiency by a factor of 1.57.

Symmetrical load lifting beside the body compared to in front of the body

Murali Subramaniyam,Seung Nam Min,Heeran Lee,Sangho Park,Se Jin Park 대한인간공학회 2014 대한인간공학회 학술대회논문집 Vol.2014 No.5

This study investigated the lifting loads beside the body compared to in front of the body. Lumbar spinal load during manual lifting is considered an important risk factor for the occurrence of work related back pain. The lumbar spinal load can be expected to increase while manual lifting in front of body compared to beside the body. The horizontal distance of the combined load relative to the low back can be reduced to zero with manual lifting beside the body. Many researchers want to collect quantitative data like low back muscle activities and lumbar loads for preventing back pain. Twenty healthy young men symmetrically lifted hand loads beside the body and in front of the body. The hand loads considered were 0, 6.5, 11.5, and 16.5 kg. Using digital human modeling (DHM) software magnitude of the low-back loads was estimated. The estimated lumbar spinal loads were moment, compression, and joint shear about L4/L5. Subjects’ anthropometric details were used to model digital human in the DHM software. The electromyography was used to measure the symmetry of erector spinae muscle activity (between right and left side) during manual lifting with in front of body and beside body. Specifically, muscle activities obtained with surface electromyography were processed with standard root-mean-square (RMS) amplitude calculations. Finally, the foot balance during manual lifting for the selected postures was measured with foot analyzer. The overall foot balance in the front, back, right, and left side of the body were estimated. Extensor moment was increased with hand loads when lifting in front of the body. Flexor moment was increased with hand loads when lifting beside the body. For the in front of the body lifting technique, the lumbar spinal load values were significantly (p < 0.05) greater than lifting beside the body. There was a significant difference (p < 0.05) in the lumbar spinal loads between the selected postures and for the hand loads. The RMS of erector spinae muscle was significantly (p < 0.05) greater when lifting in front of the body. The comparison of RMS values between the sides of the erector spinae muscle activity reveals that the left side muscle activity was greater than the right side. The foot balance map reveals that significantly (p < 0.05) greater force produced by the left side foot compared with right side to maintain balance when increased hand loads. And also there was a significant (p < 0.05) interaction effect between lifting posture and hand loads in the right side foot balance. The current study showed that lifting a symmetrical load beside the body did reduce lumbar spinal loads and erector spinae muscle activities; this was probably due to the reduced horizontal distance between the hand loads and low back (L4/L5).

Modeling and Postural Analysis of Digital Human Motion in Virtual Environment for Material Handling

Murali Subramaniyam,Sangho Park,Sung il Choi,Se Jin PARK (사)한국CDE학회 2009 한국 CAD/CAM 학회 학술발표회 논문집 Vol.2009 No.2

Muscle activity and spinal loading in lifting symmetrical loads beside the body compared to in front of the body

Murali Subramaniyam,민승남,박세진,박상호 대한기계학회 2015 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.29 No.12

Digital human modeling enables engineers in product development to address questions of ergonomics and human factors early on inthe development. To build more accurate Digital human models (DHMs), the physiological standard reference data are necessary. Weinvestigated the effects of lifting loads beside the body compared to in front of the body. Forty healthy subjects performed eight liftingtasks with combinations of two postures, and four loads. The magnitude of the erector spinae muscle activity: Median frequency (MF)and Normalized root-mean-square (N-RMS) was estimated using surface electromyography. The magnitude of the lumbar spinal loadsabout lumbar vertebrae was estimated using DHM software. The effect of the moment arms (5, 6, 7.5 and 8.5 cm) on the lumbar spinalloads was estimated biomechanically. Lifting loads beside the body significantly (p < 0.01) reduced the muscle fatigue, muscle activity,and spinal loads. The increased moment arms resulted in the reduction of compression (5-13%) and muscle force (16-41%). The resultpresented in this study could be used to build more accurate DHMs.

Alcohol Intoxication Effects on Simulated Driving

( Murali Subramaniyam ),( Seoung Eun Kim ),( Se Jin Park ),( Heeran Lee ),( Seung Nam Min ) 한국감성과학회 2015 추계학술대회 Vol.2015 No.-

Alcohol intoxication and driving is responsible for a high proportion of traffic accidents. Drunken driving is the act of driving a motor vehicle with blood alcohol concentration (BAC) level in excess of a legal limit. In Korea, the legal limit for BAC is 0.05 %. Even with a small amount of alcohol intake, drivers are twice likely to be involved in traffic accidents than normal drivers. Alcohol use impairs drivers’ cognition, vigilance, attention, judgment, reaction, vision, and braking behavior. This pilot study was to investigate effects of alcohol intoxication on physiological behavior and driving performance in different BAC levels in a simulated driving environment. The physiological measures were EEG (alpha and theta frequency in the frontal and occipital region), and ECG (heart rate and R-R interval). The driving performance measured were accident rate and the number of time violating the specified speed limit (50, 70, 90, 110 km/h). Participants consisted of four healthy young male drivers (Age: 31 ± 4.3 years). The BAC levels considered were 0.00 % (control), 0.03, 0.05 and 0.1 %. The scenario considered was 5 min driving in a highway with different speed limits and unexpected event. Results showed that decreased alpha and increased theta frequency was observed with increased BAC level. Heart rate was increased with increased BAC level. The accident rate and the number of time violating the speed limit were significantly (p<0.05) higher with higher BAC level. Alcohol intoxication affected drivers’ decision-making ability, vision and integrating visual information ability.

Internet of Things (IoT) Applications - Possibilities of Wake-up Stroke Monitoring

( Murali Subramaniyam ),( Seung Hee Hong ),( Kim Da Mee ),( Yong Duck Park ),( Se Jin Park ) 한국감성과학회 2016 추계학술대회 Vol.2016 No.-

Influence of Aging on Isometric Muscle Strength and Lifting Capacity

( Murali Subramaniyam ),( Sangho Park ),( Seung Nam Min ),( Se Jin Park ) 한국감성과학회 2015 추계학술대회 Vol.2015 No.-

The Korean population is constantly evolving. According to the National Statistical Office (NSO), people over 65 years of age will account for 38.2 percent of Korea’s population in 2050, making it the most aged society among the 30 member economies of the Organization for Economic Cooperation and Development (OECD). Lifting tasks have been shown to be a risk factors of low back injuries in young adults. As aging is related to loss of muscle strength, working elderly subjects exposed to manual handling and lifting tasks may be more prone to develop back injuries. The manual lifting strategies influenced by back and leg extensors strength. This study sought to investigate whether the isometric muscle strength and lifting capacity affected by aging. The sample consisted of a total of 45 elderly (20 male and 25 female) and 40 young (20 male and 20 female) adults. Lifting capacity was measured with the back-leg dynamometer. Isometric muscle strength was recorded simultaneously with the capture of the electrical activity of left (LT) and right (RT) side lumbar erector spinae (ES) muscle. A surface electromyography (sEMG) system was used to measure the electrical activity of the muscles. Results showed that there was a significant reduction in elderly lifting capacity than younger adults. The elderly adults had significantly lower muscle strength in the isometric muscle strength compared to younger adults.