• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.15 no.4
• /
• pp.68-80
• /
• 2016

This study proposes the traffic prediction and optimal traffic control system based on cell transmission model and genetic algorithm in cloud environment. The proposed prediction and control system consists of four parts. 1) Data preprocessing module detects and imputes the corrupted data and missing data points. 2) Data-driven traffic prediction module predicts the future traffic state using Multi-level K-Nearest Neighbor (MK-NN) Algorithm with stored historical data in SQL database. 3) Online traffic simulation module simulates the future traffic state in various situations including accident, road work, and extreme weather condition with predicted traffic data by MK-NN. 4) Optimal road control module produces the control strategy for large road network with cell transmission model and genetic algorithm. The results show that proposed system can effectively reduce the Vehicle Hours Traveled upto 60%.

• Journal of agricultural medicine and community health
• /
• v.45 no.3
• /
• pp.121-129
• /
• 2020

Purpose: As dementia progresses, cognitive function decreasing leads to memory loss, speech degradation, time and space degradation and judgment degradation, which causes difficulties in carrying out tasks related to daily life. It was said that community-based non-drug intervention therapy for early dementia patients was important to participate in entertainment treatment, including activities such as awareness and exercise therapy, exercise rehabilitation, aerobic exercise, and art. Methods: This study conducted 15 experimental and 15 control groups(experimental group : Fumanet exercise, control group : general occupational therapy) for eight weeks at the Daycare Center in Gyeonggi-do to find out the impact of the Fumanet exercise program on cognitive and depression functions of the elderly. The pre-post evaluation used KGDS, MMSE. Results: There were significant differences between the two groups in the function of menopause, memory recall, attention concentration and calculation, and depression, and no significant results were obtatined in memory registration, language function, understanding and fracture. The Fumanet movement was judged to be effective in improving cognitive function and reducing depression for the elderly with dementia. Conclisions: The Fumanet movement was judged to be effective in improving cognitive function and reducing depression for the elderly with dementia.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.31 no.1D
• /
• pp.65-72
• /
• 2011

When an expressway intersects another expressway, a unique connector needs to be designed between the two consecutive exit ramps. In such a case, it is important to design a connector such that there is enough distance for drivers to find their way safely. A current design manual in Korea prescribes the minimum length of the connector as 240 m. In this research, we have suggested a method for calculating the minimum length of a connector in order to check the feasibility of the currently prescribed length. For this purpose, we have attempted to determine the total perception-reaction time and lane-changing time required by a driver. For determining the driver's perception-reaction time, we have used the driver's decision time in addition to the conventional 2.5 s of perception-reaction time for stopping sight distances. We have considered both the design speed and the average travel speed for the calculation of the length. To evaluate the accuracy of the new method, we have chosen four sites on expressways for which relatively high accident rates were recorded. As a result, we could verify that the current limit (240 m) was sufficient for drivers to be able to change lanes in the given specific geometry. However, the prescribed limit should be revised in case the drivers' decision time is considered to be their perception-reaction time. All new approaches for calculating the ideal length of a connector have been carried out by taking into account the design speed as well as the average travel speed. Owing to the characteristics of the specific geometry for two consecutive exit ramps and the large difference between the design speed and the average travel speed in the objective areas, it is more realistic to use the proposed method by keeping the decision time equal to a driver's perception-reaction time, in order to determine the ideal distance that should be maintained between two consecutive exit ramps.

• Korean Journal of Cognitive Science
• /
• v.27 no.3
• /
• pp.469-499
• /
• 2016

The present study investigated the cognitive mechanism underlying online processing of Korean syntactic (for example, A bed/a clock belongs to/doesn't belong to the furniture "침대는/시계는 가구에 속한다/속하지 않는다") and lexical negation (for example, A tiger/a butterfly has/doesn't have a tail "호랑이는/나비는 꼬리가 있다/없다") using an ERP(Event-related potentials) technique and a truth-value verification task. 23 Korean native speakers were employed for the whole experiment and 15's brain responses (out of 23) were recorded for the ERP analysis. The behavioral results (i.e. verification task scores) show that there is universal pattern of the accuracy and response time for verification process: True-Affirmative (high accuracy and short latency) > False-Affirmative > False-Negated > True-Negated. However, the components (early N400 & P600) reflecting the immediate processing of a negation operator were observed only in lexical negation. Moreover, the ERP patterns reflecting an effect of truth value were not identical: N400 effect was observed in the true condition compared to the false condition in the lexically negated sentences, whereas Positivity effect (like early P600) was observed in the false condition compared to the true condition in the syntactically negated sentences. In conclusion, the form and location of negation operator varied by languages and negation types influences the strategy and pattern of online negation processing, however, the final representation resulting from different computational processing of negation appears to be language universal and is not directly affected by negation types.

• Management & Information Systems Review
• /
• v.33 no.1
• /
• pp.17-43
• /
• 2014

research tries to present the role of perceived justice and authenticity in service recovery process. Prior research on the service recovery have focused on relationship among perceived justice, recovery satisfaction and positive customer behavior. Especially perceived justice including distributive, procedural, and interactional justice has addressed as most important antecedents of recovery satisfaction. Although the pivotal role of perceived justice for successful service recovery has agreed by many researchers, relatively little attention has been paid to emotional aspect of customer. During the service recovery process, even if customer perceived recovery effort from service provider as justice one, they might feel displeasure or dissatisfaction. It means prior researches have underestimated the importance of emotional aspect while they focus on cognitive aspects. The one research focused on emotional aspects examined effect of authenticity in service context with other related factors. However, solely examined effect of authenticity is not enough to present proper implication effect between justice and authenticity so that it can be understood more clearly. In this study, we examined customer reactions to service failure and recovery process in restaurant service settings. Specifically, we focused on the moderating effect of authenticity on the paths between perceived justice and outcome variables such as forgiveness and recovery satisfaction.

• Korean Journal of Cognitive Science
• /
• v.19 no.2
• /
• pp.177-203
• /
• 2008

The present study was aimed to compare the semantic systems represented by the lexicon between L1 and L2 in late Korean-English bilinguals. The participants performed the word-picture matching task. the task was to decide whether the pictures represent the previously presented words' meaning. The words were the basic level categories. The stimuli were consisted of common object belonged to two different semantic categories (natural and artificial). To control the translation strategies, the SOA were manipulated as 650ms(Exp. 1) and 250ms(Exp. 2). No translation effort was found in the comparison of the two experiments. In both experiment, the RTs were faster in L1 rendition, and it took longer to decide the stimuli in natural categories than with artificial ones in L1. However, this category effect was not observed in L2. The results showed the differences in the organization of semantic representations in the brain through the bilinguals' two languages. While L1 semantic knowledge might be more systematically organized, that of L2 seems to be less well organized, at least by late bilinguals who participated in the present study.

• Journal of the Institute of Electronics and Information Engineers
• /
• v.52 no.6
• /
• pp.117-125
• /
• 2015

In the modern age, it is important for people to maintain a good sitting posture because they spend long hours sitting. Posture correction treatment requires a great deal of time and expenses with continuous observation by a specialist. Therefore, there is a need for a system with which users can judge and correct their postures on their own. In this study, we collected users' postures and judged whether they are normal or abnormal. To obtain a user's posture, we propose a four-joint motion capture system that uses inertial sensors. The system collects the subject's postures, and features are extracted from the collected data to build a database. The data in the DB are classified into normal and abnormal postures after posture learning using the K-means clustering algorithm. An experiment was performed to classify the posture from the joints' rotation angles and positions; the normal posture judgment reached a success rate of 99.79%. This result suggests that the features of the four joints can be used to judge and help correct a user's posture through application to a spinal disease prevention system in the future.

• Journal of the Korea Society for Simulation
• /
• v.25 no.3
• /
• pp.65-76
• /
• 2016

Self-adaptive software is software that adapts by itself to system requirements about the recognized problems without stopping the software cycle. In order to reduce the unnecessary adaptation in the system having the critical points, we propose proactive approach which can predict the future operation after a critical point. In this paper, we predict the future operation after a critical point using a hybrid model to deal with the characteristics of the observed data with the linear and non-linear pattern. The operation of the prediction method is determined on a timing decision indicator based on the prediction accuracy. The two main points of contributions of this paper are to reduce uncertainty about the future operation by predicting the situation after a critical point using hybrid model and to reduce unnecessary adaptation implementation by deciding a timing based on a timing decision indicator.

• Therapeutic Science for Rehabilitation
• /
• v.7 no.4
• /
• pp.31-41
• /
• 2018

Objective: This study was to develop computerized screening test items for mild cognitive impairment. Methods: Through literature reviews, items from computerized tests for screening mild cognitive impairment were extracted. A panel of professional experts validated that the items were important and fit to screen for mild cognitive impairment. Results: A total 37 items were extracted from 12 computerized tests and 11 new items were added through the first panel review. After that, 18 items were removed via the second panel review. Finally, 16 items were selected by analyzing content validity ratio. 16 items consisted of memory, attention, and executive function areas. Conclusions: A total of 16 computerized test items were developed. It is urgent to validate them to screen mild cognitive impairment. Moreover, standardization studies for this test are required in the future.

• Journal of Digital Convergence
• /
• v.17 no.2
• /
• pp.283-292
• /
• 2019

The loss of semantic knowledge and impairments in semantic associations by semantic category is gaining increasing attention, as indicators of early-stage cognitive decline. As such, we assigned semantic association task (SAT) to normal elderly (NE) and those with subjective memory impairment (SMI) or mild cognitive impairment (MCI) to examine their performance by semantic subcategories and the differences in error patterns. We found a significant difference in the number of correct response and reaction time under the SAT categories among the three groups, with the highest performance observed in 'function' and the lowest performance in 'superordinate' and 'part/whole'. Moreover, the error frequency was the lowest in NE, followed by those with SMI and MCI, with the latter two groups showing a significant increase in no-response. Our findings demonstrate the varying extent and process of impairments in the semantic network by category over different stages of cognitive decline. Thus, we proposed SAT performance as an indicator to detect and follow-up on cognitive decline in elderly with cognitive disorder.