• Journal of the Institute of Electronics Engineers of Korea SP
• /
• v.47 no.5
• /
• pp.9-17
• /
• 2010

This paper presents a localization perception of a phantom sound image for ultrahigh-definition TV with respect to various loudspeaker configurations; two-horizontal, two-vertical and triplet loudspeakers. Vector base amplitude panning algorithm with modification for non-equidistant loudspeaker setup is applied to create the phantom sound image. In order to practically study the localization performance in real situation, the listening tests were conducted at the on-axis and off-axis positions of TV in normal listening room. A method of adjustment which can reduce the ambiguity of a perceived angle is exploited to evaluate the angles of octave-band signals. The subjects changed the panning angle until the real sound source and virtually panned source were coincident. A spatial blurring can be measured by examining the differences of the panning angles perceived with respect to each band. The listening tests show that the triplet panning method has better performance than vertical panning in view of perceptual localization and spatial blurring at both on-axis and off-axis positions.

• Journal of Korean Elementary Science Education
• /
• v.33 no.4
• /
• pp.751-761
• /
• 2014

이 연구의 목적은 과학적 예상 과정에서 초등학생의 안구운동을 분석하여 과학적 예상의 인지전략을 발견하는 것이다. 예상은 관찰, 측정, 추론과 같은 기초 탐구 과정들을 통해 문제를 해결하는 중요한 탐구 능력이다. 6학년 초등학생 40명이 자발적으로 이 연구에 참여했으며, 과학적 예상 두 과제를 해결하였다. 예상 과제는 점진적으로 변화하는 모형의 다음 모양을 예상하는 것과 14일 간의 기온 그래프를 보고 다음 5일간의 기온을 예상하는 과제였다. 과학적 예상 과정에서 참가자들의 안구 운동을 기록하기 위해 SMI사의 안구운동 추적기를 사용하였다. 40명의 참가자들 중 15명(그룹 A)은 두 과제를 모두 해결하였으며, 17명(그룹 B)은 하나의 과제만 해결하였고, 8명(그룹 C)은 두 과제 모두 해결하지 못했다. 예상 능력이 높은 학생과 낮은 학생의 인지 전략의 차이를 규명하기 위해 그룹 A와 그룹 C의 안구운동을 비교 분석하였다. 연구 결과는 다음과 같다. 첫째, 그룹 A는 짧은 시간 동안 문제를 읽고 문제의 주요어에 집중했으며, 단서들을 비교하고 경향성을 찾고 답을 재확인하는 활발한 움직임을 보였다. 그룹 C는 문제 자체를 이해하는데 긴 시간이 걸렸으며, 주요어와 단서를 찾지 못하고, 무의미한 짧고 빠른 도약 안구 운동을 보였다. 둘째, 그룹 A와 C의 안구 운동의 고정, 도약, 시선 경로를 분석한 결과, 6가지의 안구 운동 패턴이 나타났다. 셋째, 안구운동 분석결과를 토대로 참가자들의 인지 전략을 유동전략과 고착전략의 두 가지로 구분하였다. 본 연구에서 규명한 과학적 예상의 인지전략은 교사들이 과학적 예상의 문제 해결 단계에서 학생들이 겪는 어려움을 이해하고, 예상 능력을 향상시키는 프로그램을 개발하는 것에 도움이 될 것이다.

• Korean Journal of Cognitive Science
• /
• v.30 no.1
• /
• pp.1-30
• /
• 2019

The main goal of this paper is to understand the underlying cognitive mechanisms of collaborative learning and how it can be supported by technology. The paper first overviews changes in conceptions of learning and distinguishes different types of joint works including collaborative learning. Cognitive mechanisms of collaborative learning are examined in terms of resource pooling, facilitation of constructive activities, knowledge co-construction, and supports for monitoring and regulation. Socio-emotional mechanisms of collaborative learning moderate the directions and strengths of these cognitive mechanisms. Technology supports these mechanisms in a number of different ways. Seven major supports technology provides for collaborative learning are discussed. A deeper understanding of the cognitive mechanisms of collaborative learning can help us to harness the benefits of collaborative learning better and also to develop more sophisticated tools supporting collaborative learning.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
• /
• v.12 no.1
• /
• pp.58-71
• /
• 2019

This paper proposes architecture of a cognitive radio engine platform and the allowable frequency channel reasoning method that enables acquisition of the allowable channels for the military tactical network environment. The current military tactical wireless communication system is increasing need to secure a supplementary radio frequency to ensure that multiple wireless networks for different military wireless devices coexist, so that tactical wireless communication between the same or different systems can be operated effectively. This paper presents the allowable frequency channel reasoning method based on cognitive radio engine for realizing DSA(Dynamic Spectrum Access) as an optimal available frequency channel. To this end, a case-based allowable frequency channel reasoning method for cognitive radio devices is proposed through modeling of primary user's traffic status and calculation of channel occupancy probability. Also through the simulation of the performance analysis, changing rate of collision probability between the primary users' occupancy channel and the available channel acquisition information that can be used by the cognitive radio device was analysed.

• Journal of Convergence for Information Technology
• /
• v.11 no.1
• /
• pp.254-260
• /
• 2021

This study was conducted to investigate the effect of Occupation-based Reminiscence training on cognitive function, depression, and quality of life of the normal elderly. Subjects were 19 normal elderly. The evaluation was evaluated using the Montreal Cognitive Assessment Korean Version, Short Form of Geriatric Depression Scale-Korean Version, and the Geriatric Quality of Life. The Occupation-based Reminiscence training was conducted once a week for an hour for a total of 8 weeks. The collected data was confirmed using the Wilcoxon signed test. As a result of the training, significant positive changes in cognitive function, depression, and quality of life of the subjects were confirmed after application of Occupation-based Reminiscence training. From this result, it was confirmed that the Occupation-based Reminiscence training is a positive training method for improving cognitive function and preventing dementia of the normal elderly.

• 한국노년학
• /
• v.39 no.2
• /
• pp.389-404
• /
• 2019

The present study aims to examine the relationship between self-reported sensory impairment and cognitive function among older adults in Korea. Drawn from the 2017 Survey of Living Conditions and Welfare Needs Korean Older Persons, a total of 10,082 adults aged 65 and over were included in analyses. Results from hierarchial multiple regression analysis show that those who reported greater subjective discomfort about vision, hearing, and oral function were more likely to have poor cognitive function. Results from hierarchial logistic regression analysis show. Results from logistic regression analysis show that having hearing and oral discomfort increased the a risk for dementia. Findings suggest that it is necessary to manage sensory function of the elderly at the government level and to develop self-evaluation tools to monitor changes in sensory function for older adults. Future research should target finding effective ways to improve health of older adults.

• Journal of Nutrition and Health
• /
• v.42 no.7
• /
• pp.639-649
• /
• 2009

This study aims at investigating the psychosocial factors that influence on the intake of fruits and vegetables according to stage of change in rural children. Total 256 elementary school children, located in Yeongi-Gun, Chungnam-Do were surveyed from May 14 2007 to May 30 2007. Stage of change on the intake of fruits and vegetables of the students was categorized into three stages: precontemplation (PC), contemplation & preparation (CO&PR) and action (AC). Psychosocial factors consist of decisional balance based on pros and cons, process of change of cognitive and behavioral processes, and self-efficacy. The recognition of cons out of decisional balance showed the highest score in the subjects at the stage of PC and lowest score in those action stage. While, no difference was shown in the score of recognition of pros among the stages. Both levels of cognitive and behavioral process of change showed no difference between two pre-action stages, PC and CO&PR. However, the subjects of action stages got higher scores in more number of the variables in both of cognitive and behavioral process of change compared to those of pre-action stages with more remarkable in results vegetables than in fruits. The results of self-efficacy on fruits and vegetables intake showed that the higher stages of change, the higher the self-efficacy score. From the result, it is suggested that the items and level of psychosocial factors are different according to the stage of change and between fruits and vegetables in rural children.

• Journal of rehabilitation welfare engineering & assistive technology
• /
• v.12 no.1
• /
• pp.10-19
• /
• 2018

The present study was to investigated the effects of motion-based virtual reality training on cognitive function and activities of daily living in patients with stroke. This study was participated in forty one patients with acute stroke. All subjects were randomly assigned into either the experimental group(n=20) or the control group(n=21). The both groups received the conventional occupational therapy during 30 min a day, 5 a week, 4 a weeks. Additionally, experimental group performed motion-based virtual reality training on each session during 30 min/day, and control group conducted conventional occupational therapy on each session during 30 min/day. The outcome measures were the LOTCA(Loewenstein Occupational Therapy Cognitive Assessment), TMT(Trail Making Test), VM(Visual Memory), K-MBI(Korean Modified Barthel Index). In comparison of change score of cognitive function, the experimental group showed a significantly greater improvements in attention and visual working memory than the control group(p<.05). As a result for change score of activities of daily living, the experimental group showed a significant greater improvement in self care than the control group(p<.05). Our findings suggest that motion-based virtual reality training may have a effects of the improvements of cognitive function and activities of daily living than conventional therapy in patients with acute stroke.

• Korean Journal of Cognitive Science
• /
• v.16 no.3
• /
• pp.189-197
• /
• 2005

In this study, changes in performance of 2-back task, blood oxygen saturation and heart rate due to $40\%$ concentration oxygen supply were observed. Five male $(25.8\pm1.3)$ and five female $(23.0\pm1.0)$ college students were nked to perform 2-bark task during two types of oxygen (concentration $21\%,\;40\%$) administration. The experimental sequence consisted of Rest1(1 min.), 0-back Task (1 min.), 2-bark Task (2 min.), and Rest2 (4 min.) and the physiological signals such as blood oxygen saturation and heart rate were measured throughout the stages. The experimental result showed that the performance increased significantly at $40\%'s$ concentration of oxygen rather than $21\%'s$, which shows oxygen supply has positive influence on cognitive performance. When $40\%$ concentration oxygen is supplied, the oxygen saturation in the blood increased and heart rate was decreased significantly comparing to $21\%$. It is Suggested that $40\%$ oxygen can stimulate brain activation bY increasing actual blood oxygen concentration in the process of cognitive performance, and hyperoxia makes heart rate decrease.

• Journal of Digital Convergence
• /
• v.15 no.1
• /
• pp.485-495
• /
• 2017

This study looked into the effects of acceptance and commitment therapy(ACT) program on the premenstrual symptoms, attitudes toward menstruation and perceived stress, in females in their 20's suffering from premenstrual syndrome(PMS). Among the 263 students from 3~4 year universities, 21 were selected as participants. 7 were assigned to the acceptance and commitment therapy(ACT) group, 7 were assigned to the cognitive behavior therapy(CBT) group, and 7 were assigned to the control group. As a result, emotional factor from the premenstrual symptoms has significantly decreased more in the acceptance and commitment therapy(ACT) group, and the cognitive behavior therapy(CBT) group in comparison to the control group. In regards to attitudes toward menstruation, there were no statistical significance in the acceptance and commitment therapy(ACT) group, however there were positive changes, and the cognitive behavior therapy(CBT) group displayed significant change in the follow-up study. In perceived stress, acceptance and commitment therapy(ACT) group displayed more significant decrease than the control group and the cognitive behavior therapy(CBT) group, and that level remained unchanged until the follow-up study.