• Korean Journal of Adult Nursing
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• v.23 no.6
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• pp.584-594
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• 2011

Purpose: The purpose of this study was to identify the prevalence of visual and hearing impairment and to investigate the effect of visual and hearing impairment on depression and cognitive function in community-dwelling Korean elderly. Methods: The study population consisted of a representative community sample of 4,028 persons aged 65 and older from the Korean Longitudinal Study of Aging 2008. Depression and cognitive function were measured by CES-D 10-item scale and K-MMSE. Visual and hearing impairment were measured by 5-Likert scale. Data were analyzed using Rao-Scott ${\chi}^2$-test, simple and multiple logistic regression. Results: The prevalence of visual and hearing impairment were 37.3% and 14.0%, respectively. Of the participants, the prevalence of depression was 58.4% and cognitive impairment was 50.6%. There were significant differences in depression and cognitive function according to visual and hearing impairment. Far vision and hearing impairment were predictors for both depression and cognitive impairment even after covariates had been adjusted. Conclusion: These data suggest that visual and hearing impairment in older adults may increase their probability of experiencing depression and cognitive impairment. Thus sensory impairment should be considered a risk factor for mental health and the cognitive function of elderly.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.7 no.7
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• pp.1533-1546
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• 2013

Wireless multicast is considered as an effective transmission mode for the future mobile social contact services supported by Long Time Evolution (LTE). Though wireless multicast has an excellent resource efficiency, its performance suffers deterioration from the channel condition and wireless resource availability. Cognitive Radio (CR) and Device to Device (D2D) are two solutions to provide potential resource. However, resource allocation for cognitive wireless multicast based on D2D is still a great challenge for LTE social networks. In this paper, a joint sub-carriers and power allocation model based on D2D for general cognitive radio multicast (CR-D2D-MC) is proposed for Orthogonal Frequency-Division Multiplexing (OFDM) LTE systems. By opportunistically accessing the licensed spectrum, the maximized capacity for multiple cognitive multicast groups is achieved with the condition of the general scenario of imperfect spectrum sensing, the constrains of interference to primary users (PUs) and an upper-bound power of secondary users (SUs) acting as multicast source nodes. Furthermore, the fairness for multicast groups or unicast terminals is guaranteed by setting a lower-bound number of the subcarriers allocated to cognitive multicast groups. Lagrange duality algorithm is adopted to obtain the optimal solution to the proposed CR-D2D-MC model. The simulation results show that the proposed algorithm improves the performance of cognitive multicast groups and achieves a good balance between capacity and fairness.

• The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.3 s.59
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• pp.17-25
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• 2006

석유, 철강 등과 함께 주파수 자원은 정보화 사회에서 소중한 자산으로 사용이 한정되어 있는 유한자원이다. 새로운 서비스를 위해 새로 할당할 대역이 더 이상 남아 있지 않는 지금, 주파수 부족 현상은 광대역 멀티미디어 통신 서비스를 제공해야 하는 차세대 무선 통신 서비스를 실현함에 있어서 큰 걸림돌이 될 것으로 예상된다. 하지만 FCC의 보고에 따르면 할당된 주파수 대역이 효율적으로 사용되고 있지 않음을 확인할 수 있다 이러한 관찰은 주파수 부족 현상이 주파수 자원이 가지고 있는 유한성의 문제보다는 비효율적으로 운영되고 있는 주파수 관리 방식에 원인이 있다는 것을 말해준다. Cognitive Radio 기술은 이렇게 비효율적으로 사용되고 있는 지금의 상황을 해결해줄 수 있는 기술로 주목받고 있다. Cognitive Radio에 대한 많은 연구가 지금까지 진행되어 왔지만 아직까지 단일화된 정의나 구체적인 시나리오가 제시되지 않은 상태이다. 이에 따라 본 고에서는 Cognitive Radio 기술이 적용될 수 있는 구체적 시나리오를 파악하고자 주요 관점 별로 구체적인 시나리오를 제시하고 각 시나리오에 따라서 Cognitive Radio 기술이 어떠한 방식으로 주파수 사용 효율을 높일 수 있는 지와 이때 요구되는 핵심 기술들에 대해 논의한다.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2003.05a
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• pp.931-939
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• 2003

This paper is aimed at proposing a new framework to predict decision performance, by Investigating decision maker's cognitive resonance. We assume that every decision maker has two kinds of schema­emotional schema and rational schema. Cognitive resonance is believed to have a close relationship with the two schemata and decision performance. In literature on decision performance there is no study' seeking relationship among the two schemata ana cognitive resonance. Therefore, our research purposes are twofold: (1) to provide a theoretical basis for the proposed framework describing the causal relationships among two schemata, cognitive resonance, and decision Performance, and (2) to empirically prove its validity applying to. Internet shopping Situation. Based on the questionnaires from 13S- respondents, we used a second order confirmatory factor analysis (CFA) to extract valid constructs, and structural equation model (SEM) to calculate path coefficients and prove the statistical validity of our proposed research model. Experimental results supported our research model with some further research issues.

• Proceedings of the Korean Society for Cognitive Science Conference
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• 2000.05a
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• pp.189-194
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• 2000

본 연구에서 면대면과 CMC상황에서 기저율과 개별정보를 통합해야하는 과제를 집단으로 결정하는 과제를 수행한 후, 집단 구성원들은 자신의 의견과 집단의 의견에 관해 다른 확신 수준을 보임을 발견하였다. 면대면 집단의 구성원이었던 사람들은 자신은 기저율과 개별정보를 둘 다 적게 사용하였지만 자신의 집단은 이 두 가지 정보를 모두 많이 사용하였다고, 지각하였으며, CMC집단의 구성원이었던 사람들은 자신과 자신의 집단이 유사한 정도로 기저율과 개별정보를 사용하였다고 지각하였다. 본 연구에서는 면대면 집단 조건에서는 집단 극화가 발생하였지만, CMC집단의 경우에는 오히려 억제되는 결과를 보였다. 이는 기존의 연구에 비추어 볼 때, 토론 시간의 부족에 기인한 것으로 고려되어지며, 추가 연구를 통해 더 많은 시간이 주어질 때 이 두 집단간에 어떠한 차이가 발생하는지 알아보고자 한다.

• International journal of advanced smart convergence
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• v.12 no.2
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• pp.17-24
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• 2023

Given the surge in the elderly population, and increasing in dementia cases, there is a growing interest in digital therapies that facilitate steady remote treatment. However, in the cognitive assessment of digital therapies through clinical trials, the absence of log data as an essential evaluation factor is a significant issue. To address this, we propose a solution of utilizing weighted derived variables based on high-importance variables' accuracy in log data utilization as an indirect cognitive assessment factor for digital therapies. We have validated the effectiveness of this approach using machine learning techniques such as XGBoost, LGBM, and CatBoost. Thus, we suggest the use of log data as a rapid and indirect cognitive evaluation factor for digital therapy users.

• ETRI Journal
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• v.42 no.6
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• pp.976-986
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• 2020

Internet of Things (IoT) is considered the future network to support wireless communications. To realize an IoT network, sufficient spectrum should be allocated for the rapidly increasing IoT devices. Through cognitive radio, unlicensed IoT devices exploit cooperative spectrum sensing (CSS) to opportunistically access a licensed spectrum without causing harmful interference to licensed primary users (PUs), thereby effectively improving the spectrum utilization. However, an open access cognitive IoT allows abnormal IoT devices to undermine the CSS process. Herein, we first establish a hard-combining attack model according to the malicious behavior of falsifying sensing data. Subsequently, we propose a weighted sequential hypothesis test (WSHT) to increase the PU detection accuracy and decrease the sampling number, which comprises the data transmission status-trust evaluation mechanism, sensing data availability, and sequential hypothesis test. Finally, simulation results show that when various attacks are encountered, the requirements of the WSHT are less than those of the conventional WSHT for a better detection performance.

• Korean Journal of Cognitive Science
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• v.29 no.1
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• pp.61-84
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• 2018

This paper aims to examine the philosophical significance of neuroethics and its unique position within the cognitive paradigm, and to discuss major issues of neuroethics. Recent advances in neuroscience enable more direct access and intervention to human mind, which reduces the distinction between matter and mind and brings up new philosophical questions on human nature. Neuroethics takes interdisciplinary and integrative approach, in order to deal with the ethical issues related to new findings and technology of neuroscience that cannot be covered by the traditional legal and social systems. Some of the ethical issues of neuroscience overlap with the classical bioethics problems but majority of major issues are unique to neuroethics. These issues are mainly related to mind reading through the observation and decoding of brain activities and to cognitive enhancement through directly manipulating brain functions. Considering the current status and trends of Korean neuroscientific research, it is necessary to begin in-depth discussion of neuroethical issues with the collaboration among experts in related fields.

• Journal of the Korean earth science society
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• v.26 no.5
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• pp.387-394
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• 2005

We have analyzed the science-gifted educational program (year 2002) at the Seoul National University in terms of its educational objectives, scientific models, and cognitive processes in scientific inquiry in order to provide insights into developing and improving science-gifted educational program. We assumed the following items as important factors for teaching scientifically gifted students: higher-order thinking skills involving synthesis domain in the educational objectives, highly abstract nature and complexity in the scientific models, cognitive processes of planning experiments in the cognitive processes in scientific inquiry. According to the analyzed results, the program has the following characteristics: (1) the rates of both higher and lower-order thinking skill domain in the educational objectives are similarly high, but the rate of synthesis domain is relatively low; (2) in the case of the scientific models, the rate of the multiple concepts and/or processes model is relatively low, while the level of the abstractness is relatively on average (3) cognitive processes of authentic scientific inquiry is not thoroughly reflected in the scientific inquiry activities, and very few cognitive processes of planning experiments factor is reflected. Therefore, we conclude in the synthesis domain in the educational objectives, multiple concepts and/or processes model, and cognitive processes of planning experiments should be especially reflected more on the science-gifted educational program in order to serve the needs of scientifically gifted students.

• Korean Journal of Cognitive Science
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• v.22 no.2
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• pp.103-121
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• 2011

This study investigated how spatial dimension information and dimensional consistency between learning and testing phase would influence the target search performance. The participants learned spatial layouts of Lego blocks shown in either two- (2D) or three-dimension (3D) and were tested with the rotated stimuli ($0^{\circ}$, $90^{\circ}$, $180^{\circ}$, or $270^{\circ}$ from the initial view) in consistent or inconsistent dimension. Significantly better performance was observed when initial learning display appeared in 2D than in 3D. Particularly, the participants showed difficulties in flexible usage of spatial information presented in 3D especially if the dimensional information in the testing phase also was 3D and required mental rotation. The present study indicates that spatial map presented in 2D may be more useful than 3D in driving situations in which acquired spatial information from navigating device, such as GPS, and location of driver continuously changes.