• The Journal of Korean Physical Therapy
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• 제29권6호
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• pp.303-306
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• 2017

Purpose: Gait variability is defined as the intrinsic fluctuations which occur during continuous gait cycles. Increased gait variability is closely associated with increased fall risk in older adults. This study investigated the influence of attention-demanding tasks on gait variability in elderly healthy adults. Methods: We recruited 15 healthy elderly adults in this study. All participants performed two cognitive tasks: a subtraction dual-task (SDT) and working memory dual-task (WMDT) during gait plus one normal gait. Using the $LEGSys^+$ system, we measured the coefficient of variation (CV %=$100{\times}$[standard deviation/mean]) for participants' stride time, stride length, and stride velocity. Results: SDT gait showed significant increment of stride time variability compared with usual gait (p<0.05), however, stride length and velocity variability did not difference between SDT gait and usual gait (p>0.05). WMDT gait showed significant increment of stride time and velocity variability compared with usual gait (p<0.05). In addition, stride time variability during WMDT gait also significantly increased compared with SDT gait (p<0.05). Conclusion: We reported that SDT and WMDT gait can induce the increment of the gait variability in elderly adults. We assume that attention demanding task based on working memory has the most influence on the interference between cognitive and gait function. Understanding the changes during dual task gait in older ages would be helpful for physical intervention strategies and improved risk assessment.

• 감성과학
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• 제23권4호
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• pp.3-20
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• 2020

본 연구의 목적은 노화에 따라 나타나는 시공간 주의배분능력과 정서지각 편향성의 변화에 대해 탐구하는 것이다. 본 연구에서는 시공간 주의배분능력을 측정하기 위해 useful field of view (UFOV) 과제와 정서지각 편향성을 측정하기 위해 정서지각과제(emotional perception task)를 사용하였다. 본 연구에는 노인 집단의 23명과 청년 집단의 25명의 총 48명의 실험참가자가 참여하였다. 실험 결과, UFOV 과제에서는 노인 집단이 청년 집단에 비해 느린 반응속도와 낮은 정답률을 보여 노인 집단이 청년 집단보다 저하된 시공간 주의배분능력을 가지고 있다는 것을 나타냈다. 또한, 정서지각과제에서는 노인 집단이 청년 집단에 비해 긍정적 정서지각 편향성과 부정적 정서지각 편향성 모두 크게 나타났다. 상관분석 결과에서는 정서지각과제의 정답률에 대한 부정적 정서지각 편향성이 UFOV 과제의 시야각 30° 조건의 반응속도와 유의미한 정적 상관관계가 나타났다(r=.289). 또한, 정서지각과제의 정답률에 대한 긍정적 정서지각 편향성은 UFOV 과제의 모든 시야각 조건들의 정답률과 유의미한 정적 상관관계가 나타났으며(r=.305, r=.322, r=.299), 반응속도와 유의미한 부적 상관관계가 나타났다(r=-.345, r=-.295, r=-.308). 이러한 결과는 노화가 저하된 시공간 주의배분능력 그리고 긍정적 정서지각 편향성과 부정적 정서지각 편향성의 증가와 관련있다는 것을 의미하고, 노화에 따라 나타나는 긍정적 및 부정적 정서지각 편향성은 저하된 시공간 주의배분능력과 관련성이 있는 것으로 여겨진다.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2011년도 추계학술발표대회 논문집
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• pp.324-327
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• 2011

SolarPACES(Solar Power and Chemical Energy systems) is an international organization under the REWP(Renewable Energy Working Party)in the IEA(International Energy Agency) and focuses on the technology development and market expansion of CSP(Concentrating Solar Power). Seventeen countries including Rep. of Korea participate in the ExCo(Executive Committee) of SolarPACES. The ExCo meeting helds two times in a year and the second ExCo meeting opens in company with the five Task meetings. Rep. of Korea takes part in the Task-1officially. The 81th ExCo and Task meetings were held during September 18 and 19 in Spain with SolarPACES conference which also continued in succession to September 23 in this year. This paper introduces the activities which have been under progressed in the Task-1 and Task-3based on this time attendance of the meeting. In accordance with the expansion of CSP market and technology development, the needs for the standardization and project status underway in the world are increasing. Therefore, build an international project database and standard of the CSP technology are the main activities in the Task-1 and the standardization is also connected with the Task-3. In addition, to increase the reliability of the new technology of CSP and to reduce the concern of investors, the Task-1 is making guidelines for CSP performance prediction which can provide medium quality calculated performance data of PTC(Parabolic Trough Concentrator) type technology widely used and occupies over 90% CSP market.

• 한국음향학회지
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• 제6권2호
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• pp.5-14
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• 1987

소음과 음악이 정신작업에 어떠한 영향을 미치는가를 검토하기 위해, 국민학생을 대상으로 소음그룹과 음악그룹으로 나누어 좌반구작업으로서 수의 가산데스트를, 우반구작업으로서 그림의 패턴찾기 테스트를 실시하였다. 그 결과소음과 음악의 작업에 미치는 영향은 매우 달랐다. 음악그룹의 피험자가 가산작업을 한 경우의 작업량은 평균 작업량보다 다 적은 주기를 나타내는 경향이 있다. 이것은 좌반구에서 가제작업과 음악처리간의 간섭때문이다. 한편, 소음하에서의 의 가산작업은 소음과 가산작업이 좌우 다른 반구에서 처리되므로 소음의 영향은 나타나지 않았다. 소음하의 패턴 찾기 테스트에서는 피험자가 작업중에 동요를 나타내는 경향을 보였다. 의미없는 소음은 우반구에서 처리되기 때문에 이것은 우반구에서의 간섭효과로 실명할 수 있다.

• 정보교육학회논문지
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• 제15권3호
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• pp.449-458
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• 2011

본 연구는 사이버대학생의 과제가치, 지각된 유용성이 학습성과(학습몰입, 학습지속의향)에 미치는 영향과 교수실재감의 매개효과를 분석하기 위해, H 사이버대학생 137명을 대상으로 수행되었다. 그 결과, 과제가치와 지각된 유용성은 학습몰입과 학습지속의향에 유의미한 영향을 미치는 요인으로 확인되었으며, 교수실재감은 과제 가치와 지각된 유용성이 학습성과(학습몰입, 학습지속의향)을 예측하는 데 있어 매개역할을 하는 것으로 나타났다. 이와 같은 결과는 사이버대학생의 학습성과(학습몰입, 학습지속의향)를 높이기 위해서는 과제가치, 지각된 유용성 향상을 위한 학습과정 설계 전략과 함께 교수자의 역할과 행동, 촉진을 제공하기 위한 노력이 필요함을 시사한다.

• The Journal of Korean Physical Therapy
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• 제27권5호
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• pp.292-298
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• 2015

Purpose: The purpose of this study was to examine the effects of dual tasks on balance and postural control during standing in patients with cerebellar ataxia (CA). It was hypothesized that CA patients would exhibit different sway characteristics of the center of mass (COM) depending on the complexity of the secondary cognitive tasks compared with normal control subjects. Methods: A total of 8 patients with CA and age-matched healthy control subjects participated in this study. They were instructed to perform two balance tasks (non-dual and dual movement) with 3 different complexity of dual tasks. Range, variability, and velocity of COMs were measured. Results: According to the results CA patients showed deficits in balance and postural control with increased dual-task complexity during the static balance task in saggital sway movements. However, there was no significant difference in static balance in frontal sway. With higher difficulty in the cognitive task, CA patients took longer to stabilize their body center, while normal control subjects showed no change between conditions. In addition, CA patients had a greater COM resultant velocity during recovery in the dual-task condition compared with the single-task condition. These findings indicate that CA patients had defendable compensatory strategies in performing dual tasks. Conclusion: In conclusion, CA patients appeared to manage the priority to balance and postural control. Particularly in a situation with a postural threat such as when potential consequences of the loss of stability increase, they appeared to prioritize the control of balance and posture over the performance of the secondary task.

• 한국멀티미디어학회논문지
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• 제10권7호
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• pp.882-892
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• 2007

본 논문에서는 임베디드 실시간 운영체제 수준에서 주기적 및 비주기적 태스크 스케줄링뿐만 아니라 태스크들의 일시적인 결함을 복구할 수 있는 결함허용이 가능한 임베디드 실시간 태스크 관리 메커니즘을 제안한다. 기존의 임베디드 운영체제들은 주기적 및 비주기적 태스크들을 동시에 고려한 스케줄링 메커니즘을 지원하지 않는다. 그리고 태스크 결함 복구 메커니즘의 미지원으로 인해 결함 태스크로 인한 시스템 고장을 야기할 수도 있다. 제안된 결함허용 실시간 태스크 관리 메커니즘은 운영체제 수준에서 주기적 태스크들의 마감시한과 비주기적 태스크의 실행완료를 보장할 뿐만 아니라 일시적인 결함이 발생한 태스크를 복구함으로써 태스크 결함으로 인한 시스템 고장을 방지할 수 있다.

• 한국수학교육학회지시리즈A:수학교육
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• 제55권1호
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• pp.107-127
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• 2016

The purpose of this study was to explore the possibility of mathematical instruction through performance task activities based on the The Backward Design, which was suggested at first by Wiggins & McTighe in 1998. The Design deals with a performance assessment task involving the whole objective and its entire content of a lesson. Based on the Backward Design, this study established the mathematical instructional materials, which deal with the concept of 'the sector' taught in middle school, with one large performance task including three small tasks. It is important that in the lesson students be guided to achieve the several learning goals by themselves through reasoning activities. For this purpose, a formal interview was carried out by the subject of three middle school mathematics teachers. As a result, in order to implement the instruction utilizing the performance tasks more efficiently in future, it is required that a large performance task should be selected or developed including the content or problem contexts to be relevant with the real-life challenging situations. In addition, to make students enhance reasoning skills, it is strongly requested that the tasks including the utilization of supplementary materials such as technological devices or manipulatives be dealt with in a lesson.

• 인터넷정보학회논문지
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• 제20권1호
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• pp.113-124
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• 2019

Recently, Omni Channel Services has been considered the most innovative business strategy. Omni-Channel sees a variety of channels from all channels viewpoints, organically combining each channel to provide a seamless experience for consumers. In other words, Omni-Channel is not simply a systematic integration of channels, but a means of delivering consistent services to consumers in all processes through a strategy to an organic connection. The aim of this study is to provide a comprehensive insight into the decision factors affecting the adoption of Omni-channel. For this purpose, an empirical analysis is conducted on the course of acceptanceof the Omni-channel service based on the Unified Theory of Acceptance and Use of Technology (UTAUT) and Task-technology fit (TTF), an effective model frequently selected to describe the acceptance of service in the introduction phase of new information technology. As a result of the study, it was confirmed that the task characteristics and the technical characteristics had a positive effect on the task-technology fit, and the task-technology fit had a positive effect on the performance expectancy. In addition, task-technology fit, performance expectancy, and social influence have a positive effect on the intention to use the Omni-Channel. This study is intended to deliver an experimental meaning by proposing a strategical measure to understand the behaviorsand uses of consumers in the Omni-channel service environment and increase the customer satisfaction for the system.

• 로봇학회논문지
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• 제16권1호
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• pp.56-63
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• 2021

As the use of robots in service area increases, research has been conducted to replace human tasks in daily life with robots. Among them, this study focuses on the tidy-up task on a desk using a robot arm. The order in which tidy-up motions are carried out has a great impact on the success rate of the task. Therefore, in this study, a neural network-based method for determining the priority of the tidy-up motions from the input image is proposed. Reinforcement learning, which shows good performance in the sequential decision-making process, is used to train such a task planner. The training process is conducted in a virtual tidy-up environment that is configured the same as the actual tidy-up environment. To transfer the learning results in the virtual environment to the actual environment, the input image is preprocessed into a segmented image. In addition, the use of a neural network that excludes unnecessary tidy-up motions from the priority during the tidy-up operation increases the success rate of the task planner. Experiments were conducted in the real world to verify the proposed task planning method.