• 한국전문물리치료학회지
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• 제30권4호
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• pp.306-313
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• 2023

Background: As social problems due to the acceleration of the aging era and the increase in the elderly population are becoming serious, virtual reality (VR)-based healthcare is emerging as an approach for preventing and managing health issues. Objects: This study used validity and reliability analyses to examine the clinical efficacy that is, the clinical value and usability of a novel VR cognitive evaluation system index that we developed. Methods: We developed a VR cognitive evaluation system based on motion recognition analysis evaluation for individuals aged 65 to 85. After conducting the Korean version of the Mini-Mental State Exam (K-MMSE) cognitive evaluation, the evaluation score was verified through correlation analysis in the VR cognitive evaluation system. To verify the construct validity of the two groups, the Global Deterioration Scale (GDS) grades were categorized into a normal cognitive group (GDS grade 1) and a cognitive impairment group (GDS grades 2 and 3). The data were measured twice to determine the reliability between the two measurements and assess the stability and clinical value of the evaluation system. Results: Our evaluation system had a high correlation of 0.85 with the widely used K-MMSE cognitive evaluation. The system had strong criterion-related validity at the 95% confidence interval. Compared to the average score of GDS grade 1 in the VR cognitive evaluation system, the average score of GDS grades 2 and 3 in the VR cognitive evaluation system was statistically significantly lower while also having strong construct validity at the 95% confidence interval. To measure the reliability of the VR cognitive evaluation system, tests-retests were conducted using the intraclass correlation coefficient (3,1), which equaled 0.923 and was statistically significant. Conclusion: The VR cognitive evaluation system we developed is a valid and reliable clinical tool to distinguish between normal cognitive status and mild cognitive impairment.

• Physical Therapy Rehabilitation Science
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• 제11권4호
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• pp.571-578
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• 2022

Objective: Cognitive-motor trainings had a positive impact on cognitive function and dual-task trainings led to improvements of global cognitive function. The brain activity of the prefrontal cortex (PFC) is another indicator that can infer cognitive function. This study aims to confirm the usability of the interactive system cognitive-motor training program and the changes in the prefrontal cortex through training. Design: Cross-sectional study Methods: In this study, two cognitive tasks were randomly applied to 20 adults as cognitive-motor training using an interactive system, and the same task was performed using the original method. During all tasks, the brain activity of the prefrontal cortex was measured by the change in oxyhemoglobin (HbO) in real-time using Functional Near-Infrastructure. After performing the tasks, the usability of the developed interactive system was evaluated by a usability questionnaire which consists of five items, and each item consists of a 7-point Likert scale that responds from 1 point to 7 points. Results: The HbO levels were increased during cognitive task performance than at the resting phase. And evaluating the usefulness of the interactive system, a questionnaire result showed that it would be useful for cognitive-motor programs. Conclusions: The cognitive-motor training using the interactive system increased the activity of the prefrontal cortex, and the developed wearable sensor-based interactive system confirmed its usefulness.

• 한국IT서비스학회지
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• 제18권4호
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• pp.1-22
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• 2019

Companies have attempted to build a rational and future-oriented new personnel system in order to adapt and survive in a rapidly changing environment. Recently, Samsung, LG, SK, and CJ, which are large domestic corporations, have been introducing new types of simplified personnel systems competitively. Although there are several prior studies that tried to classify these simplified personnel systems from a strategic point of view, there is a lack of empirical research in terms of the specific types from the perspective of employees. Therefore, in this study, an empirical study on the simplified personnel system which has currently been highlighted was carried out. The relationship between perceived justice (i.e., distributive justice and procedural justice) and organizational effectiveness (i.e., organizational commitment and innovative behavior) were tested. In addition, the mediating role of cognitive attitude as well as the moderating role of cognitive intensity in the simplified personnel system were investigated. The results of structural equation model using 157 survey data show that both distributive and procedural justice have a positive effect on cognitive attitude toward the simplified personnel system, which in turn leads to increased organizational commitment and innovative behavior. Interestingly, it is found that cognitive intensity intensifies the effect of distributive justice on cognitive attitude, whereas it attenuates the influence of procedural justice as expected. This study is among one of the first empirical studies focusing on the simplified personnel system and expands the concept of related variables such as perceived justice, cognitive attitude, and cognitive intensity in this context. Moreover, by clarifying the causal relationship between perceived justice and organizational effectiveness through the roles of cognitive attitude and cognitive intensity, it could provide several practical implications to managers who are interested in the introduction and early settlement of simplified personnel systems in a successful manner.

• Nuclear Engineering and Technology
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• 제39권6호
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• pp.703-716
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• 2007

As digital and computer technologies have grown, human-machine interfaces (HMIs) have evolved. In safety-critical systems, especially in nuclear power plants (NPPs), HMIs are important for reducing operational costs, the number of necessary operators, and the probability of accident occurrence. Efforts have been made to improve main control room (MCR) interface design and to develop automated or decision support systems to ensure convenient operation and maintenance. In this paper, an integrated decision support system to aid operator cognitive processes is proposed for advanced MCRs of future NPPs. This work suggests the design concept of a decision support system which accounts for an operator's cognitive processes. The proposed system supports not only a particular task, but also the entire operation process based on a human cognitive process model. In this paper, the operator's operation processes are analyzed according to a human cognitive process model and appropriate support systems that support each cognitive process activity are suggested.

• Nuclear Engineering and Technology
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• 제52권1호
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• pp.78-86
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• 2020

The operation and monitoring (OM) interface is the digital medium between nuclear power system and operators. The cognitive load of OM interface has an important effect on the operation errors made by operator during OM task between operator and computer. The cognitive load model of OM interface is constructed for analysing the composition and influencing factors of OM interface cognitive load. And to study the coping strategies and methods for cognitive load of nuclear power system. An experiment method based on eye movement is proposed to measure the cognitive load of OM interface. Experiment case is carried out with 20 subjects and typical OM interface of a nuclear power system simulator. The OM interface is optimized based on the experiment results. And the results comparison between the original OM interface and the optimized OM interface shows that the cognitive load model and proposed method is valuable contributions in reducing the cognitive load and improving the interaction efficiency of OM tasks.

• 한국통신학회논문지
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• 제32권11A호
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• pp.1096-1105
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• 2007

본 논문에서는 MB-OFDM UWB 시스템의 간섭 회피 기술로서 무선 인지 기술(Cognitive Radio)을 사용하였다. 간섭 신호를 측정하기 위한 방안으로 FCC에서 제안한 무선 인지 기술의 간섭 온도 모델(Interference Temperature Model) 사용한다. 간섭 온도 측정을 통하여 MB-OFDM UWB 시스템의 채널 용량(Channel Capacity)를 계산한 후 간섭 상황을 해결하는 방안을 제시한다. 계산 과정에 해당하는 인지 엔진(Cognitive Engine)의 연산 알고리즘으로 사용될 유전 알고리즘을 사용하였다. 본 논문에서 제안한 국내 환경에 적합한 무선 인지 기술(Cognitive Radio using Interference Temperature Model Access)을 이용한 MB-OFDM UWB 시스템은 현재 문제가 될 수 있는 UWB 통신 시스템의 간섭문제를 해결하는데 좋은 성능을 보여주고 있는 것을 확인하였다.

• 대한의용생체공학회:의공학회지
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• 제35권6호
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• pp.197-202
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• 2014

The cognitive rehabilitation training is important for treating many cognitive impairment conditions, including Parkinson's disease, stroke, and ADHD. In this study, we developed a new evaluation system to improve the measurement of the conventional evaluation systems for cognitive rehabilitation training. The developed system measured the activity of dopamine(DA) and an autonomic nervous system(ANS) with photoplethysmography and electromyography. The results demonstrated that the cognitive capacity was increased but the activity of DA was decreased with unbalanced ANS by short-term stress. Based on the results, the effect of short-term stress should be recognized for the cognitive rehabilitation training.

• 제어로봇시스템학회논문지
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• 제15권1호
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• pp.111-119
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• 2009

For daily life interaction with human, robots need the capability of encoding and storing cognitive information and retrieving it contextually. In this paper, spatiotemporal grounding of cognitive information for a language based cognitive system is presented. The cognitive information of the event occurred at a robot is described with a sentence, stored in a memory, and retrieved contextually. Each sentence is parsed, discriminated with the functional type of it, and analyzed with argument structure for connecting to cognitive information. With the proposed grounding, the cognitive information is encoded to sentence form and stored in sentence memory with object descriptor. Sentences are retrieved for answering questions of human by searching temporal information from the sentence memory and doing spatial reasoning in schematic imagery. An experiment shows the feasibility and efficiency of the spatiotemporal grounding for advanced service robot.

• 제어로봇시스템학회논문지
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• 제15권11호
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• pp.1115-1121
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• 2009

For HRI (Human-Robot Interaction) in daily life, robots need to recognize non-rigid objects such as clothes and blankets. However, the recognition of non-rigid objects is challenging because of the variation of the shapes according to the places and laying manners. In this paper, the cognition of non-rigid object based on a cognitive system is presented. The characteristics of non-rigid objects are analysed in the view of HRI and referred to design a framework for the cognition of them. We adopt a linguistic cognitive system for describing all of the events happened to robots. When an event related to the non-rigid objects is occurred, the cognitive system describes the event into a sentential form and stores it at a sentential memory, and depicts the objects with a spatial model for being used as references. The cognitive system parses each sentence syntactically and semantically, in which the nouns meaning objects are connected to their models. For answering the questions of humans, sentences are retrieved by searching temporal information in the sentential memory and by spatial reasoning in a schematic imagery. Experiments show the feasibility of the cognitive system for cognizing non-rigid objects in HRI.

• 인지과학
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• 제15권4호
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• pp.15-20
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• 2004

유연성과 광범위성을 갖는 대규모 인지 시스템의 구축을 위해서는 전문적인 지식 뿐 아니라 상식 수준의 지식을 포함한 대용량 지시베이스의 구축이 필수 불가결하다. 이를 위해서는 효율적인 지식 표현 및 추론 기법이 핵심적 열할을 하게 될 것이다. 본 논문에서는 정성적 지식 표현 및 추론 기법을 이미 구축된 범용의 대용량 Cyc 지식베이스와 접목하여, 일상의 상식적인 추론을 제공할 수 있는 인지 시스템을 소개한다. 본 시스템은 구현되어 여러 예제에 적용되어 그 실효성을 입증한 수 있었다.