• 한국안전학회지
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• 제21권5호
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• pp.103-111
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• 2006

The purpose of this study was to analyse the relationships between cognitive abilities and driving characteristics of elderly drivers. Driving characteristics of elderly and younger drivers who were driving a fixed base driving simulator vehicle were examined. Participants consisted of 12 drivers over age 65 (the 'older' group) and 12 drivers between the ages of 25 and 55 (the "younger" group). As indices of cognitive ability, critical flicker fusion frequency (CFF) tests and cognitive reaction tests were given before the driving task. CFF was also tested after the simulated driving task for both groups. Cognitive reaction tests, which were composed of speed estimation tests, multiple choice reaction tests and obstacle avoidance tests, were developed by the Korean Road Traffic Safety Authority in 2003. CFF values between the two groups exhibited significant differences both before and after the task, with a p-value less than 0.01 and a t-value of -3.01 before the test and a p-value less than 0.031 and a t-value of -2.35 after the test. Older drivers' CFF values were lower than those of the younger. However, there was no difference in older or younger driver CFF values before and after the task within the same group. Except for the multiple choice reaction test, there was no difference in cognitive reaction test results between the two groups. The elderly drivers made more errors though they did not differ from the younger drivers in reaction times. At the simulated driving task the reaction time of the elderly driver was longer than that of the younger; however, the driving speed of the elderly was lower and the number of collisions greater. There was a positive correlation (r=.496) between the number of errors in the multiple choice reaction test and the number of collisions in the driving task. Therefore, it was identified that critical attributes contributing to automobile crashes involving elderly drivers included cognitive difficulty in judging and responding to complex situations.

• 대한통합의학회지
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• 제1권4호
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• pp.15-24
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• 2013

Purpose : The purpose of this pilot study was to examine the effects of task-oriented training program on balance, activities of daily living(ADL) performance, and self-efficacy in stroke patients. Method : Two subjects with stroke in experimental group participated in the task-oriented training program, while two subjects with stroke in control group received traditional rehabilitation therapy for 4 weeks, 30 minutes per session, four times per week. The task-oriented training program consisted of four tasks with 4 difficulty levels. In two groups, balance was examined with using the Berg Balance Scale(BBS), ADL performance was examined with using the Modified Barthel Index(MBI), and Self Efficacy was evaluated with using the Self-Efficacy scale(SES) before and after 4-week training. Result : After 4 weeks training, all scores of measurement variables increased in both the experimental group and the control group, but the average rates of change differed between the two groups. After the training program, the scores of BBS, MBI, and SES in experimental group increased to 11.4%, 9.9%, 15.4%, respectively than pre-training. Conclusion : According to the results of this study, task-oriented training program might be proposed as a intervention to improve balance ability, ADL performance, and self-efficacy in stroke patients.

• 정보처리학회논문지B
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• 제11B권5호
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• pp.597-602
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• 2004

최근 웹이나 가상환경에서는 아바타의 활용이 증가하고 있으나, 아바타의 행위를 사용자가 직접 제어하는 수준의 서비스는 이루어지지 못하고 있다. 또한 기존에 제공되었던 언어들에는 제어에 필요한 복잡한 세부 정보들이 많이 포함되어 있어서 사용자가 작성하기에 까다로움이 많았으며, 작성한 언어를 다른 작업 도메인에 적용하고자 할 때에도 언어를 수정하거나 재 작성해야하는 번거로움이 있었다. 따라서 본 논문에서는 아바타의 행위를 간단히 정의하기 위해, 작업수준별 아바타의 행위를 작성 할 수 있는 “작업 수준의 행위 표현 언어”와 동작에 관련된 세부적인 데이터를 작성 할 수 있는 “동작 표현 언어”로 각각 정의하였다. 또한 시스템 내에 “인터프리터”를 두어 동작 표현 언어를 자동으로 생성 할 수 있도록 함으로써, 사용자가 행위 표현 언어만으로 아바타의 행위를 쉽게 제어 할 수 있는 시스템을 구성하였다. 이러한 내용을 사이버 강의에 적용해 보고, 정의한 작업 수준의 행위 표현 언어를 기존 언어들과 비교하여 아바타의 행위를 얼마나 간단히 표현할 수 있는지 검토하였다.

• 영어어문교육
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• 제12권4호
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• pp.69-89
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• 2006

This study investigated whether and how semantic nature of intransitive verbs can be related to the L2 overpassivization errors. A total of 126 Korean high school students participated in a grammaticality judgment test on English sentences in which seven semantically different types of intransitive verbs were passivized. The results showed that there was an effect of semantic type on the students' judgment on overpassivization errors. Overall, it was shown that the students experienced the lowest degree of difficulty with the Controlled Process-Motional type verbs while experiencing the high degree of difficulty with the Change of State, Existence of State, Continuation of Pre-existing State, and Uncontrolled Process types. Two interlanguage patterns were also identified: the students at higher proficiency level and those at lower-proficiency level showed distinctive patterns on the task. It was argued that the simple dichotomy of unaccusative-unergative distinction does not suffice for the explanation of the complex phenomenon of L2 overpassivization.

• International Journal of Safety
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• 제10권1호
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• pp.32-35
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• 2011

Lifting capacity and difficulty of task are influenced by body posture. In RULA and REBA, the body was divided into segments which formed two groups, A and B. Group A includes the upper and lower arm and wrist while group B includes the neck, trunk and legs. This ensures that whole body posture is recorded so that any awkward or constrained posture of the legs, trunk or neck which might influence the posture of the upper limb. This study aimed to measure MVC (maximum voluntary contraction) and subjective judgment in psychophysical method (Borg's scale) according to trunk and upper arm angle and to analyze results statistically. The results of this study were that lifting capacity was more influenced by interaction of body posture rather than angles of each part, and MVC variation according to trunk and upper arms angles should different patterns. This means that we consider the interaction of trunk angles and upper arm angles when we access risk factors of the postures. This survey would be also the basic data to evaluate difficulty of lifting tasks according to body postures ergonomically.

• International Journal of Advanced Culture Technology
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• 제11권2호
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• pp.298-309
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• 2023

The mouse as an input device has undoubtedly brought convenience to users due to its intuitiveness and simplicity, but it also brought unprecedented issues such as carpal tunnel syndrome (CTS). As a result, the necessity of alternative input devices that put less strain on the wrist, while still providing the convenience of a conventional mouse, has emerged. Unfortunately, there have been several research about alternative devices to replace a mouse, however, they showed inconsistent results. This study suggests that those inconsistent results may stem from the type and the difficulty of tasks used in previous studies. Therefore, we designed this study to compare the performance and perceived workload of three input devices (Mouse/Trackball/Touchpad) in each condition in terms of task type (Targeting/Tracking) and difficulty level (Easy/Hard). The results indicated that there were significant performance differences and no significant workload differences among the three devices, and the interactions were observed in some conditions. These results can provide users with practical guidelines to choose the optimal input device according to their needs or purpose.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제13권1호
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• pp.1-11
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• 2013

The determination of the pose of the imaging camera is a fundamental problem in computer vision. In the monocular case, difficulties in determining the scene scale and the limitation to bearing-only measurements increase the difficulty in estimating camera pose accurately. Many mobile phones now contain inertial measurement devices, which may lend some aid to the task of determining camera pose. In this study, by means of simulation and real-world experimentation, we explore an approach to monocular camera localization that incorporates both observations of the environment and measurements from accelerometers and gyroscopes. The unscented Kalman filter was implemented for this task. Our main contribution is a novel approach to landmark initialization in a Kalman filter; we characterize the tolerance to noise that this approach allows.

• 한국감성과학회:학술대회논문집
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• 한국감성과학회 2001년도 춘계학술대회 논문집
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• pp.121-124
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• 2001

Using ordors with the different concentration of essential oils, e studied the effect of a pleasant olfactory stimulation on physiological responses. we examined psychological response, mental task and changes in cardiac, immunity and EEG in responses to 150times solution (feel easily) and 500times solution (feel with difficulty) which of essential oil (called PCK) were diluted in propylene glycol, and neutral (water). The 150times solution that was felt pleasant produced significant differences (p<0.05) in relative power change of beta activity in the left frontal region (Fp1, F3, F7) of the brain, and heart rate (HR) deceleration after mental task. these results are consistent with substantial research that has documented cardiac and EEG responses to pleasant stimuli. What is more, 150times solution increased the concentration of s-IgA know as an index of immunity.

• 한국항공운항학회지
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• 제18권1호
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• pp.51-57
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• 2010

This study was to analyze the difference in pilot error by using the Signal Detection Theory. The task was to detect the targeted aircraft(signal) which is different shape from many other aircraft(noise). From the two experiments, we differentiated the task difficulty followed by change in noise stimuli. Experiment 1 was to search the signal stimuli(fighter plane) while the noise stimuli(cargo plane) were increasing. The results from the Experiment 1 showed the tendency to decrease the hit rate by increasing the number of noise stimuli. However, the false alarm rate was not increased. The sensitivity(d') showed quite high. In Experiment 2, a disturbance stimulus(helicopter) was added to noise stimuli. The result was generally similar to those of Experiment 1. However, the hit rate was lower than that of Experiment 1.

• 한국지능시스템학회논문지
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• 제11권7호
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• pp.633-640
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• 2001

In this paper we examine the machine learning issues raised by the domain of the Intrusion Detection Systems(IDS), which have difficulty successfully classifying intruders. There systems also require a significant amount of computational overhead making it difficult to create robust real-time IDS. Machine learning techniques can reduce the human effort required to build these systems and can improve their performance. Genetic algorithms are used to improve the performance of search problems, while data mining has been used for data analysis. Data Mining is the exploration and analysis of large quantities of data to discover meaningful patterns and rules. Among the tasks for data mining, we concentrate the classification task. Since classification is the basic element of human way of thinking, it is a well-studied problem in a wide variety of application. In this paper, we propose a classifier system based on genetic algorithm, and the proposed system is evaluated by applying it to IDS problem related to classification task in data mining. We report our experiments in using these method on KDD audit data.