• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.13 no.2
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• pp.12-16
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• 1999

Phantom phenomena on the signal light was observed and change of perception-reaction tirre of the observer was rreasured. If phantcm phernrena occurs, signal light perception-reaction time by the drivers is prolonged, the extent of which rmy disturb driving. Length of the percetopn-reaction time is affected by the luminance contrast between the turned-on and turned-off signals. Based on the rreasured results, several methods to prevent phantom phenorrena were suggested.

• Therapeutic Science for Rehabilitation
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• v.10 no.4
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• pp.81-94
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• 2021

Objective : Response time plays a prominent part in research on cognitive ability and the aging effect. This study aimed to identify the impact of cognitive ability on information processing by conducting cognitive response time (CRT) using a computer program. Methods : This study was conducted in 30 normal elderly (NE) and 30 elderly with amnestic MCI (aMCI), aged 65-79 years old living in Daegu and Gyeongbuk. The results were analyzed using the statistical analysis program R 4.0.2 (University of Auckland, New Zealand). Results : In the three sub-areas of CRT, the total response time showed a significant difference depending on group or age, and the error rate showed a significant difference depending on age or group in some sub-areas. In the aMCI group, the performance of CRT significantly correlated with that of the overall cognition and memory test. Conclusion : Information processing depending on aging or cognitive ability and the differential performance of processing speed could be observed through CRT. The performance of this test was found to be significantly correlated with that of the overall cognition and memory test. Therefore, CRT could be used meaningfully as a simplified tool to predict the initial cognitive disorder of the elderly in the community.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2002.05a
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• pp.278-285
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• 2002

본 논문에서는 인지적 긍정/부정 선택 과제의 수행 시 뇌파를 이용하여 피험자의 반응시간 RT를 감지하는 방법에 관하여 기술한다. 실험 Task에서 피험자는 시각적 자극에 대한 반응, 문제의 해석, 손 움직임의 조절, 손동작 등과 같은 작업을 수행한다. 이와 같은 상황에서의 피험자의 정신상태의 변화를 모델링하고, 선택시간 ST를 감지하여 피험자의 반응시간 RT를 예측한다. ST를 감지하기 위하여 측정한 뇌파로부터 $\alpha$, $\beta$, ${\gamma}$파를 분리하고, 4쌍의 전극들로부터 3가지의 특징들을 추출한다. 추출한 특징들을 분석하여 각 피험자별로 나타나는 상세 규칙과 공통적인 특성인 일반 규칙들을 설정하고 이들을 적용한다. 4명의 피험자를 대상으로 평균 81%의 ST 감지 성공률을 보이고, ST 감지 이후 약 0.73초에서 RT가 나타나는 것을 보인다. 본 논문에서 제안한 방법을 기존의 인지적인 정신상태 판별을 위한 방법들이나 왼손/오른손 동작구분 방법들과 결합하여 사용할 경우 BCI를 위한 기반 기술로 활용될 것으로 기대한다.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 1998.11a
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• pp.142-146
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• 1998

본 연구에서는 신호등에서 발생하는 Phantom 현상을 관찰하고, 이에 의해 관찰자의 인지반응시간이 변화하는 정도를 측정하였다. Phantom 현상이 발생하면 운전자의 신호등 인지시간이 길어지며, 그 정도는 운전에 장해를 줄 수 있는 정도임을 알 수 있었다. 인지시간의 길이는 점등된 신호등과 소등된 신호등 사이의 휘도 대비에 의해 영향을 받는 것으로 밝혀졌다. 측정 결과를 바탕으로 Phantom 현상을 방지하기 위한 방법들을 제안하였다.

• Journal of Korean Society of Transportation
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• v.24 no.5 s.91
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• pp.57-66
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• 2006

This paper presents new pedestrian signal timings considering pedestrian demand Pedestrian characteristics, and land use which were obtained by Pedestrian characteristics field survey and pedestrian signal operation survey. Pedestrian signal timings suggested were compared to the existing pedestrian signal timings by using real field data. pedestrian characteristics field survey was conducted to collect pedestrian crossing speed data and reaction time data. Sixteen areas in Seoul were selected for the data collection. The average pedestrian crossing speed was 1.30m/sec and the 15th Percentile speed was 1.11m/sec. The average reaction time was 2.24 seconds. Pedestrian crossing speed differs by land use, road width. pedestrian age, sex, and number of Pedestrians. Reaction time also differs by road width, pedestrian age, and number of pedestrians. Statistical testing was performed to secure reliability of the collected data.

• KIISE Transactions on Computing Practices
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• v.21 no.5
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• pp.379-386
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• 2015

We propose a novel user-perceived performance optimization framework for the Android platform that takes advantage of the user-centric response time analysis. To this end, we propose a new definition of response time, which we call the user-centric response time, as a metric for the quality of user-perceived performance of the smartphone application. In this paper, we describe the design and implementation of an on-line user-centric response time analyzer for Android-based smartphones, which provides smartphone application developers with valuable insight for user-perceived performance optimization. We implemented the user-centric response time analyzer on the Android platform, version 4.0.4 (ICS) running on a Galaxy Nexus smartphone. From our experimental results, the proposed user-centric response time analyzer accurately estimates user-centric response times with an accuracy of 92.0% compared to manually measured times with less than 1% performance penalty. In order to evaluate the efficiency of the proposed framework, we were able to reduce the user-centric response time of the target application by up to 16.4% based on the evaluation results by the proposed framework.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.10 no.4
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• pp.36-43
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• 2011

The forward collision of vehicles in high speed can cause a chain collisions and high fatality rate. Most of the forward collisions are caused by insufficient braking distance due to detection time of driver and safe distance. Also, accumulated detection time of driver is cause of chain collisions after the forward collision. The FVCWS prevents the forward collision by maintaining the safety distance inter-vehicle and reducing detection time of driver. However the FVCWS can cause chain collisions because the system that interacts only forward vehicle has accumulated detection time of driver. In this paper, we analyze forward and chain collisions of normal vehicles and FVCWS vehicles on static traveling scenario. And then, we analyze and compare V2V based FVCWS with them after explaining the system. The V2V FVCWS reduces detection time of driver alike FVCWS as well as remove accumulated detection time of driver by broadcasting emergence message to backward vehicles at the same time. Therefore, the system decrease possibility of forward and chain collisions. All backward normal vehicles and 3~4 backward FVCWS vehicles have possibility of forward and chain collisions in result of analysis. However V2V FVCWS vehicles almost do not chain collisions in the result.

• Science of Emotion and Sensibility
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• v.17 no.2
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• pp.63-76
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• 2014

Although most behavioral reaction times (RTs) for cognitive tasks exhibit positively skewed distributions, the majority of studies primarily rely on a measure of central tendency (e.g. mean) which can cause misinterpretations of data's underlying property. The purpose of current study is to introduce procedures for describing characteristics of RT distributions, thereby effectively examine the influence of experimental manipulations. On the basis of assumption that RT distribution can be represented as a convolution of Gaussian and exponential variables, we fitted the ex-Gaussian function under a maximum-likelihood method. The ex-Gaussian function provides quantitative parameters of distributional properties and the probability density functions. Here we exemplified distributional analysis by using empirical RT data from two conventional visual search tasks, and attempted theoretical interpretation for setsize effect leading proportional mean RT delays. We believe that distributional RT analysis with a mathematical function beyond the central tendency estimates could provide insights into various theoretical and individual difference studies.

• Science of Emotion and Sensibility
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• v.6 no.3
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• pp.63-72
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• 2003

This study investigated how cognitive style and training context influenced visual discrimination skill acquisition and transfer under time pressure. This experiment consisted of a screening session, a training session, and a transfer session using random polygon comparison tasks. Screening session was designed to separate participants according to their cognitive style (analytic or holistic). Training session was divided into difficult and easy conditions. In transfer session, participants compared polygon pairs in a novel task. The stimuli were presented for 1.5 seconds to examine the influence of time pressure. Through the all sessions, this experiment measured accuracy and response time. According to the results of this study, analytic group responded as quickly as holistic group in the beginning of training session because time pressure induced them to the holistic strategy. However, as training session progressed, their slopes of reaction time increased, suggesting that their own analytic style emerged. Holistic group showed flatter slopes than did analytic group for training session. Of interest is the slopes increased at the beginning of transfer session, suggesting that they developed analytic strategies in difficult training context. It is suggested individuals differently develop strategic processing skills depending on cognitive styles even under time pressure.

• Korean Journal of Psychosomatic Medicine
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• v.5 no.1
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• pp.89-96
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• 1997

This study was designed to determine whether cognitive impairment was evident in patients with SLE. Also, it aimed to examine the association of cognitive impairment with other clinical variables. The subjects consisted of 20 patients with mildly active SLE and 20 healthy controls. Methods : A total of 20 SLE patients and 20 normal controls completed a computerized neuropsychological test battery using Vienna Test System. These included Cognitrone test, Continuous attention test, Corsi block tapping test, Standard progressive matrices. Also, neuro-behavioral cognitive status examination was done. The symptom severity of depression was measured with Beck Depression Inventory, Hamilton Depression Rating Scale, and current medications were documented. Disease activity was rated using the SLE diasease activity index (SLEDAI). Results : SLE patients had poorer performance than normal controls on the tests of Cognitrone, attention, nonverbal IQ and memory, independent of age, education, disease activity, steroid use and depression status. Conclusion : Cognitive dysfunction was not uncommon in ambulatory SLE patients as measured by standardized neuropsychological tests. It seemed to occur independently of various clinical variables. These findings would suggest that cognitive dysfunction in SLE may be explained by reflecting subclinical central nervous system(CNS) involvement, rather than coexisting psychological distress due to chronic illness or side effect of medication.