• MALSORI
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• no.57
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• pp.31-42
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• 2006

The purpose of this study is to observe how Korean learners perceive an English weak syllable in words containing WS syllable pattern. According to the automated discrimination task using E-Prime, the ratio of correct answer(%) and reaction time of the stimuli with same syllable patterns were respectively higher and faster than those with different syllable patterns. Specifically, in the stimuli with different syllable patterns, the frequency(familiarity) of stressed word succeeding weak syllable and whether the weak syllable had coda in it were two important factors in distinguishing between a word with and without weak syllable. Even though the high English proficiency Koreans had faster reaction time than the low English proficiency Koreans, all Korean learners had a difficulty in perceiving the weak syllable at the beginning of a word.

• Journal of the Ergonomics Society of Korea
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• v.31 no.2
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• pp.371-377
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• 2012

Objective: The aim of this study is to investigate effect of driver's cognitive distraction on driver's physiological state and driving performance, and then to determine parameters appropriate for detecting the cognitive distraction. Background: Driver distraction is a major cause of traffic accidents and poses a serious threat to traffic safety due to ever increasing use of in-vehicle information systems and mobile phones during driving. Cognitive distraction, among four different types of distractions, prevents a driver from processing traffic information correctly and adapting to change in surround vehicle behavior in time. However, the cognitive distraction is more difficult to detect because it normally does not involve significant change in driver behavior. Method: A full-scale driving simulator was used to create virtual driving environment and situations. Participants in the experiment drove the driving simulator in three different conditions: attentive driving with no secondary task, driving and conducting secondary task of adding numbers, and driving and conducting secondary task of conversing with an experimenter. Parameters related with driver's physiological state and driving performance were measured and analyzed for their change. Results: The experiment results show that driver's cognitive distraction, induced by secondary task of addition and conversation during driving, increased driver's cognitive workload, and indeed brought change in driver's physiological state and degraded driving performance. Conclusion: The galvanic skin response, pupil size, steering reversal rate, and driver reaction time are shown to be statistically significant for detecting cognitive distraction. The appropriate combination of these parameters will be used to detect the cognitive distraction and estimate risk of traffic accidents in real-time for a driver distraction warning system.

• Proceedings of the Ginseng society Conference
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• 1980.09a
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• pp.143-150
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• 1980

The purpose of this double-blind study was to study the standardized ginseng-extract (marketed form, GINSANA), in regard to its efficacy on the reaction time, pulmonary function and general health in subjects of various age-groups. The trial was conducted as a double-blind study in a total of 120 subjectsm allocated to different groups, according to age (30 to 39 and 40 to 60 year age-groups), sex and preparation administered (ginseng/placebo). The study lasted 12 weeks and the dosage was fixed at 2 capsules per day. The rusults regarding reaction time and pulmonary function showed significant differences in favour of the GINSANA group, over the placebo group, in the 40 to 60-year-old men and women. In the self-evaluation (performance, mood, concentration) we observed a clear improvement (p < 0.001) in the subjects treated with GINSANA, with the exception of the men age 30-39 years. The results botained, which are specially related to reaction, pulmonary function, self evaluation and tolerability, have shown that GINSANA, as standardized ginseng extract, has a favourable effect on the psychic and physical functions studied. 3. Performance test in top sportsmen before and after 9 weeks' treatment with GINSANA To what extent can GINSANA influence physical performance? It is precisely we the physicians whose task it is to find drugs which in physiological amounts do not have any special pharmacodynamic effects. We were therefore interested in the preparation, GINSANA which was made available to us, since it contains a qualitatively and quantitatively standardized GINSENG EXTRACT and is not doping agent.

• Physical Therapy Korea
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• v.13 no.3
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• pp.24-32
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• 2006

Theoretical framework of motor learning is used to enhance perceptual motor skill in physical therapy intervention, which can be subdivided into two main types-explicit and implicit. The purpose of this study was to examine whether stroke patients with unilateral brain damage learn implicitly a motor skill using the arm ipsilateral to the damaged hemisphere. Speculation then followed as to the formation of therapeutic plans and instructions provided to patients with stroke. 20 patients with stroke and 20 normal participants were recruited. All the subjects practiced serial reaction time tasks for 30 minutes a day and retention tests on the following day. The tasks and tests involved pressing the corresponding buttons to 4 colored circles presented on a computer screen as quickly and accurately as possible. Patients with stroke responded more slowly than controls. However, both groups showed decreased reaction time in the experimental and retention periods. Also, there was no significant difference between both groups regarding explicit knowledge of consecutive order. Therefore, patients with stoke had the ability to learn implicitly a perceptual motor skill. Prescriptive instruction using implicit and explicit feedback may be beneficial for motor skill learning in physical therapy intervention for patients with brain damage.

• Journal of Korean Institute of Industrial Engineers
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• v.30 no.1
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• pp.11-16
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• 2004

Oxygen is an essential element for human beings' physical and mental activities, and in particular, plays an important role in brain functions. The present study attempted to investigate the effects of supply of highly concentrated (30%) oxygen on human ability of visuospatial cognition, compared to air of normal oxygen concentration (21%). This study sampled eight male university students (the average age: 23.5) as subjects. An equipment that supplies 21% and 30% oxygen at a constant rate of 8L/min was developed. Two types of questionnaire containing 20 questions were developed to measure the ability of visuospatial cognition, and accuracy and reaction time were calculated from the result of task performance. The average accuracy was $50.63{\pm}8.63$ [%] and $62.50{\pm}9.64$[%] for 21%and 30% oxygen respectively, and a statistically significant difference was found in the accuracy between the two types of oxygen. The average reaction time was $6.60{\pm}O.77$ [sec] and $7.23{\pm}0.69$ [sec] for 21%and 30% oxygen respectively, and a statistically significant difference was not found in the reaction time. The results showed that there is no difference in the average reaction time but the average accuracy rises with the supply of highly concentrated (30%) oxygen, indicating that the supply of highly concentrated oxygen has a partially positive effect on the ability of visuospatial cognition.

• IE interfaces
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• v.18 no.2
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• pp.178-183
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• 2005

In this study, changes in memory performance, blood oxygen saturation and heart rate according to 30% concentration oxygen supply were observed. Ten healthy male and female college students (male:$25.8{\pm}0.8$ years, female: $24.2{\pm}1.9$ years) participated in the study. The experiment was performed as Rest (1min.), Control task (1min.), Word presentation (1min.), Reaction time task (1min.), Distractor (2min.), and Word recall (1min.) and the physiological signals such as blood oxygen saturation and heart rate were measured throughout the stages. Subjects who received 30% oxygen recalled more words than those who received 21% oxygen, which shows 30% oxygen supply has influenced positively on memory cognitive performance. When 30% concentration oxygen is supplied, the blood oxygen saturation in the task phases was increased and the heart rate decreased when comparing to 21%. It means that 30% oxygen can stimulate brain activation by increasing actual blood oxygen concentration in the process of cognitive performance, and the heart rate decreases because enough oxygen is supplied to process the cognitive performance.

• The Journal of Korean Physical Therapy
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• v.27 no.2
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• pp.106-111
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• 2015

Purpose: Impaired reaching movement is commonly observed in children with cerebral palsy. The purpose of this study was to determine whether the inclination of seat surface can influence the reaching movement in children with spastic diplegic cerebral palsy (CP). Methods: The subjects were 31 children, 16 children with spastic bilateral CP and 15 typically developing (TD) children. The children performed static sitting and forward reaching under three conditions: a horizontal seat surface (Horizontal $0^{\circ}$), a seat surface inclined anterior 15 degrees (Ant $15^{\circ}$), and a seat surface inclined posterior 15 degrees (Post $15^{\circ}$). A 3-axis accelerometer ('ZSTAR3') was used for analysis of the reaching movement. A 3-axis accelerometer was attached on the manubrium of the sternum, lateral epicondyle of the humerus, and styloid process of the ulna. We measured the reaction time, movement time, and data amount during reaching the 8 cm target with an index finger on the three inclined seat surfaces. Results: Reaction time and movement time for CPs showed significant delay; comparing the TD's and CP's amount was significantly greater than the TD's during reaching task (p<0.05). In particular, CP's reaction time and movement time on a seat surface inclined Ant $15^{\circ}$ was significantly more delayed compared with the other seat surfaces (p<0.05). Conclusion: Our results suggest that seat-inclination intervention may provide an ergonomic approach for children with spastic cerebral palsy.

• The Journal of Korean Physical Therapy
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• v.22 no.5
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• pp.109-115
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• 2010

Purpose: This study was to delineate the structural change of neural pathway after sequential motor learning using diffusion tensor imaging (DTI). Methods: The participants were 16 healthy subjects, which were divided by training (n=8) and control (n=8) group. The task for the training was the Serial Reaction Time Task (SRTT) which was designed by Superlab program. When the 'asterisk' shows up in the 4 partition spaces on the monitor, the subject presses the correct response button as soon as possible. The training group participated in the training program of motor learning with SRTT composed of 24 digits pattern in one hour per daily through 10 days during 2 weeks. Results: In the behavioral results the training group showed significant changes in the increase of response number and the reduction of response time than those of the control group. There was significant difference in the left inferior frontal area in the fractional anisotropy (FA) map of the training group in DTI analysis. Conclusion: Motor sequential learning as like SRTT may be needed to the learning of language and visuospatial processing and may be induced for the experience-dependent structural plasticity during short period.

• Proceedings of the ESK Conference
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• 1998.04a
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• pp.167-172
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• 1998

Methods of evaluating the physiological activity of the living body are EEG, EOG, Heart rate, and Rectal temperature, etc. In the study of Hagiwara and Araki(1993), they found positive correlations among performance test, physiological measurement, and subjective feeling measurement. Human alertness of pilot directly influences on the flight performance that accomplishes a lot of vigilance task and procedure execution in flight. Accordingly, this paper deals with the quantitative and objective performance test based on tracking error and reaction time by means of the new computer test program into which the perception-motion system of human beings is applies. Throughout this experiment using performance thst, the results suggest that performance capability in state of sleep deprivation 2 hours and alcoholic 0.05 .apaprox. 0.06% in blood were more impaired than one in a normal state, and they further showed statistically significant differences between them, which were influenced by impairment factors of body regulation and pilot's grade. We also obtained the prediction value and the 95% confidence interval of tracking error and reaction time at the normal state for the purpose of distinguishing performance capability between the normal state and the abnormal state. And it is ecpected that the evaluation of human alertness using performance test will be applied to the quantitative assessment of an each pilot's realistic consciousness/attention, and will lead a flight commander to the accurate decision of mission approval prior to a flight.

• Journal of the Korean Society of Safety
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• v.23 no.1
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• pp.46-50
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• 2008

The purpose of the present study was to investigate the mariner's information characteristics in ship-ta-ship collision situation using the full mission ship-handling simulator. Risk levels of ship-to-ship collision were manipulated by whether the target ship complies with the naval regulations and by movement patterns of target ship. Dependent variables reflecting mariner's information characteristics in ship-ta-ship collision situation were measured in terms of radar detection reaction time, free recall performance of past navigation situation, and subjective ratings for the task difficulty. The results showed that, in general, the mariners appeared to be deteriorated in their radar detection reaction time and free recall performance as the risk of ship-ta-ship collision increased. Also, the mariners tended to rate required tasks more difficult in the high risk ship-ta-ship collision situation.