• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• 제20권2호
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• pp.61-67
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• 2009

Objectives: The purpose of this study was to examine the performance and electrophysiological characteristics of drug-naive children with attention-deficit/hyperactivity disorder(ADHD) during the Go/NoGo task. Methods: Twenty-three boys with ADHD and 18 age-matched normal boys were recruited at a child psychiatric outpatient clinic in Seoul. All subjects were assessed by the Kiddie Schedules for Affective Disorders and Schizophrenia Present and Lifetime version. The investigator also assessed all subjects using the ADHD Rating Scale-IV(ADHDRS). Event-related potentials were recorded from 8 scalp electrodes during the visual Go/NoGo task. Results: Children with ADHD showed a larger mean of standard deviation of response time during the Go/NoGo task than normal children. The temporal N200 and P300 amplitudes were larger in children with ADHD relative to controls. The parietal N200 and P300 latencies were more prolonged in children with ADHD compared to normal controls. Conclusion: These results suggest that psychotropic-naive children with ADHD may have more variable performance ability, more difficulty in discriminating visual stimuli, and slower information processing speed than their normal age-matched counterparts.

• 대한불안의학회지
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• 제11권1호
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• pp.33-37
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• 2015

Objective : Impaired response inhibition has been suggested to play an important role in the pathophysiology of obsessive-compulsive disorder (OCD). The aim of this study was to evaluate the response inhibition in patients with OCD, by using the Go/NoGo paradigm, and to better understand its associations with clinical symptoms. Methods : The participants included 63 OCD patients and 80 healthy volunteers matched in age and sex. response inhibition was evaluated using computerized Go/NoGo task, in which their commission error rates, omission error rates, and mean response times were measured. The severity of clinical symptoms in the OCD patients was assessed using Montgomery-Asberg Depression Scale and Yale-Brown Obsessive Compulsive Scale. Result : OCD patients showed significantly impaired inhibition and higher omission errors rates despite their slower response time, compared to normal controls. Clinical symptoms were not correlated with commission errors and omission errors. Conclusion : The present results indicate that impairment in response inhibition may play a critical role in the pathophysiology of OCD as a trait. These findings suggest that deficit of response inhibition may contribute to developing and maintaining clinical symptoms such as compelling need to repeat certain actions in patients with OCD.

• 인지과학
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• 제14권4호
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• pp.1-7
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• 2003

본 연구는 집행기능의 범주에 속하는 행동적 억제(behavioral inhibition) 기능과 행동 감시(action monitoring) 기능의 공통점을 사건관련전위 요소 및 그 뇌 신경원 분석을 통해 비교 분석하였다. 피험자들에게 Go/NoGo 과제를 수행시키면서 측정, 분석한 사건관련전위인 N200 및 P300 요소는 NoGo 조건의 경우 전두엽 쪽에서 더욱 큰 진폭을 보였다는 점에서 NoGo 조건에서 요구되는 행동적 억제기능을 반영한다고 볼 수 있었다. 또한 전두엽 영역에서 오류반응 후에 관찰되는 부적 전위인 ERN 정반응 이후 관찰되는 CRN에 비해 보다 큰 진폭과 빠른 잠재기를 보였다는 점에서 행동감시의 신호가 오류반응에 대해 보다 크게 요구되는 것이라 추론할 수 있었다. 행동적 억제의 지표인 NoGo 조건에서의 N200과 P300 요소의 잠재기와 행동감시의 지표인 ERN 요소의 진폭간에는 유의미한 부적상관이 발견되었는데, 이는 행동적 억제의 효율성이 높은 피험자일수록 행동감시의 정도 또한 크게 나타냄을 시사하는 결과라 볼 수 있었다. 이러한 집행기능 지표들간의 관련성은 이들 사건관련전위 요소들의 신경원이 거의 유사한 위치인 전대상피질(anterior cingulate cortex)에서 나타난 뇌 신경원 국소화법 결과를 통해서도 지지되었으며, 이러한 결과를 전대상피질의 집행적 통제기능이라는 맥락에서 논의하였다.

• 한국멀티미디어학회논문지
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• 제17권11호
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• pp.1325-1334
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• 2014

Recently game addiction of young people has become a social issue. Therefore, many studies, mostly surveys, have been conducted to diagnose game addiction. In this paper, we suggest how to distinguish levels of addiction based on EEG. To this end, we first classify four groups by the degrees of addiction to internet games (High-risk group, Vigilance group, Normal group, Good-user group) using CSG (Comprehensive Scale for Assessing Game Behavior) and then measure their Event Related Potential(ERP) in the Go/NoGo Task. Specifically, we measure the signals of P300, N400 and N200 from the channels of the NoGo stimulus and Go stimulus. In addition, we extract distinct features from the discrete wavelet transform of the EEG signal and use these features to distinguish the degrees of addiction to internet games. The experiments in this study show that High-risk and Vigilance group exhibit lower Go-N200 amplitude of Fz channel than Normal and Good-user groups. In Go-P300 and NoGo-P300 of Fz channel, High-risk and Vigilance groups exhibit higher amplitude than Normal and Good-user group. In Go-N400 and NoGo-N400 of Pz channel, High-risk and Vigilance group exhibit lower amplitude than Normal and Good-user group. The test after the learning study of the extracted characteristics of each frequency band from the EEG signal showed 85% classification accuracy.

• Physical Therapy Rehabilitation Science
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• 제7권3호
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• pp.109-113
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• 2018

Objective: The purpose of this study was to investigate the effects of fall experience and task complexity on gait performance in community-dwelling persons with chronic hemiparetic stroke. Design: Cross-sectional study. Methods: Thirty-three persons who had a history of stroke participated in this study. The participants included 18 persons (aged mean 54.0, mean score of 24.6 points on the Montreal Cognitive Assessment, MoCA) with fall experience (faller group) and 15 persons (aged mean 53.7, mean score of 24.7 points on the MoCA) without fall experience (non-faller group) in the previous six months. This study measured balance and gait performance at two different conditions (with/without 70% of water filled in a 200 cc cup). The participants were clinically assessed using the 10-meter walk test (10MWT), 6-minute walk test (6MWT), Berg Balance scale (BBS), Dynamic Gait Index (DGI), and Timed Up-and-Go (TUG) test. Results: After analyzation, persons in the faller group performed significantly better on the 10MWT, 6MWT, BBS, DGI, and the TUG test in the no-cup-carrying condition than those in the cup-carrying condition (p<0.05). The persons in the non-faller group also performed significantly better in all outcome measures with the no-cup-carrying condition than those in the cup-carrying condition (p<0.05). However, there was no interaction between fall experience and task complexity in the two groups. Conclusions: Our results showed that balance and gait performance depended on fall experience and task complexity but fall experience did not interact with task complexity. Clinicians should consider fall prevention and task complexity during therapeutic approaches in persons with hemiparetic stroke.

• 대한통합의학회지
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• 제6권1호
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• pp.45-54
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• 2018

Purpose : The purpose of this study is to evaluate the effects of Action-observational training program on gait and balance of patients with hemiplegia. Method : The subjects of this study are patients with hemiplegia; 10 patients who agreed with this research, were picked up. Participants were divided randomly into equal groups: experimental group that applied to action-observation training for at least 30 minutes/day for 6 weeks and control group that underwent general task-oriented training. Gait and balance were measured 10 meter walk test(10MWT), gait speed, berg balance scale(BBS) and timed up and go(TUG). The intervention were compared by measuring before and after. Result : There were significant improvements in the subscales of the gait and balance test of those who practiced with the Action-observational training program, while the control group showed no significant changes. Conclusion : Therefore, Action-observational training program is effective in improvement of to improve the gait and balance in patients with hemiplegia.

• PNF and Movement
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• 제7권4호
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• pp.31-36
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• 2009

Many daily activities require people to complete a motor task while walking. Substantial gait decrements during simultaneous attention to a variety of cognitive tasks have been shown by a group of severely injured neurological patients of mixed etiology. And previous studies have shown that the attentional load of a walking-associated task increased with its level of difficulty. The purpose of this study was to analyze subjects' gait changes are affected by the effects of arithmetic task difficulty and performance level. Participants performed a walking task alone, three different Arithmetic tasks while seated, and among them, two kinds of the simillar Arithmetic tasks in combination with walking. Reaction time and accuracy were recorded for two of the Arithmetic tasks. The mean values of the gait were measured using a Timed Up and Go test among 11 with post-stroke patients while walking with and without forward counting (WFC) and backward counting(WBC).There was significant Arithmetic Task Difficulty level between the 10-forward counting task condition(FC) and the 10-backward counting task condition(BC)(p=0.008). The mean values of T.U.G time were significantly higher under backward counting dual-task condition than during a simple walking task(p=0.009) and WFC(p=0.009). The change in T.U.G time during WFC was higher when compared with the change during a simple walking, but there was no significant difference (p=0.246). This study suggesting that a high interference could be linked with a high level of difficulty, whereas adaptive task enabled participants to perfectly share their attention between two concurrent tasks. Future research should determine whether dual task training can reduce gait decrements in dual task situations in people after stroke. And the dual-task-based exercise program is feasible and beneficial for improving walking ability in subjects with stroke.

• 인지과학
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• 제34권3호
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• pp.153-180
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• 2023

행동 효과(action effect)란, 특정 자극에 대한 단순한 행동이 이후의 시각 탐색 과제에서 해당 자극의 인지적 처리를 향상시키는 효과를 말한다. 본 연구는 행동을 지시하는 단어의 의미적 표상과 실제로 수행하는 행동의 종류가 행동 효과에 미치는 영향을 알아보고자 시행되었다. 실험 1은 선행 연구의 실험 패러다임을 반복 검증하였다. 참가자는 화면을 통해 제시되는 "출발" 또는 "정지"의 행동 지시어를 보고 뒤이어 나타나는 원형 자극에 대하여 키보드를 이용해 응답하거나(출발 조건) 응답하지 않았다(정지 조건). 다음으로, 참가자는 한쪽으로 기울어진 선분을 찾아 기울어진 방향을 보고하는 시각 탐색 과제를 수행하였다. 이때 표적 자극은 이전에 제시되었던 원형 자극 위에 나타나거나(타당 조건) 다른 자극 위에 나타날 수 있었다(비타당 조건). 시각 탐색 과제의 반응 속도를 분석한 결과, 선행연구와 동일한 행동 효과(행동 조건과 타당도 조건의 상호작용)를 관찰할 수 있었다. 실험 2에서는 반응 도구 및 물리적 행동의 종류가 상이한 경우에도 행동 효과가 유지되는지 알아보고자 진행되었다. 참가자는 제시되는 행동 지시어에 대하여 키보드를 이용해 응답하였으나, 시각 탐색 과제에서는 조이스틱 방향을 조정함으로써 반응을 보고하였다. 그 결과, 타당도에 따른 주효과 및 행동 효과 모두 유의한 것으로 나타났다. 단어의 의미적 표상이 행동 효과에 미치는 영향을 알아보기 위하여, 실험 3에서는 두 행동 조건 모두 반응을 하지 않게 하였고, 실험 4에서는 두 행동조건 모두 각기 다른 키를 사용하여 반응하게 하였다. 그 결과, 두 실험 모두 타당도에 따른 주효과만 유의미했으며 행동 효과는 관측되지 않았다. 실험 3과 실험 4의 결과를 비교 분석한 결과, 실험 유형과 타당도 간의 상호작용이 관찰되었다. 본 연구는 행동 지시어의 의미적 표상만으로는 행동 효과를 야기할 수 없으며, 이중과제 패러다임에서 물리적 반응의 도구 및 종류와 상관없이 행동 효과가 관찰될 수 있다는 점을 시사한다.

• 정형스포츠물리치료학회지
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• 제14권2호
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• pp.117-126
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• 2018

Purpose: The purpose of this study was to evaluate the effect of task-oriented exercise and abdominal muscle contraction using functional electrical stimulation (FES) on abdominal muscle thickness and balance of stroke patients. Methods: Ten stroke patients who met the selection criteria were assigned randomly into two groups of five. One group received FES therapy before task-oriented training (experimental group), while the other group received a FES placebo before task-oriented training (control group). The Mann-Whitney U test was used to compare the groups, and the Wilcoxon Signed-ranks test was used to compare differences between the groups before and after intervention. The Mann-Whitney U test was used to compare the rate changes of each item before and after intervention, between the two groups. Results: In the rectus abdominalis and external oblique muscle thickness tests that used ultrasound, there was a statistically significant difference in the experimental group (p<.05),but no significant difference in the control group (p>.05). There was also a significant difference between the groups (p<.05). In the Balance test that used the Berg Balance Scale (BBS) and timed up and go test (TUG), there was a statistically significant difference in the experimental and control groups (p<.05), but there was no significant difference between the groups (p>.05). Conclusions: FES therapy before task-oriented training increases the thickness of abdominal muscles and improves balance abilities.

• 한국국방경영분석학회지
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• 제17권1호
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• pp.146-158
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• 1991

In this paper, we deal with the TSP (Traveling Salesperson Problem) which is well-known as NP-complete optimization problem. the TSP is applicable to network routing. task allocation or scheduling. and VLSI wiring. Well known numerical methods such as Newton's Metheod. Gradient Method, Simplex Method can not be applicable to find Global Solution but the just give Local Minimum. Exhaustive search over all cyclic paths requires 1/2 (n-1) ! paths, so there is no computer to solve more than 15-cities. Heuristic algorithm. Simulated Annealing, Artificial Neural Net method can be used to get reasonable near-optimum with polynomial execution time on problem size. Therefore, we are able to select the fittest one according to the environment of problem domain. Three methods are simulated about symmetric TSP with 30 and 50-city samples and are compared by means of the quality of solution and the running time.