• Transactions on Control, Automation and Systems Engineering
• /
• 제4권1호
• /
• pp.100-107
• /
• 2002

The advanced bilateral control algorithm, which can enlarge a reflected force by combining force reflection and compliance control, greatly enhances workability in teleoperation. In this scheme the maximum boundaries of a compliance controller and a force reflection gain guaranteeing stability and good task performance greatly depend upon characteristics of a slave arm, a master arm, and an environment. These characteristics, however, are generally unknown in teleoperation. It is, therefore, very difficult to determine such maximum boundary of the gain. The paper presented a novel method for design of an advanced bilateral controller. The factors affecting task performance and stability in the advanced bilateral controller were analyzed and a design guideline was presented. The neurofuzzy compliance model (NFCM)-based bilateral control proposed herein is an algorithm designed to automatically determine the suitable compliance for a given task or environment. The NFCM, composed of a fuzzy logic controller (FLC) and a rule-learning mechanism, is used as a compliance controller. The FLC generates compliant motions according to contact forces. The rule-learning mechanism, which is based upon the reinforcement learning algorithm, trains the rule-base of the FLC until the given task is done successfully. Since the scheme allows the use of large force reflection gain, it can assure good task performance. Moreover, the scheme does not require any priori knowledge on a slave arm dynamics, a slave arm controller and an environment, and thus, it can be easily applied to the control of any telerobot systems. Through a series of experiments effectiveness of the proposed algorithm has been verified.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2003년도 ICCAS
• /
• pp.1109-1114
• /
• 2003

In this paper, task control architecture is proposed for a mobile robot with behaviors based on cognition theory to endow the robot intelligence. In the task control architecture, task manager is introduced especially for the management of computational resource. The management is based on classical RMS (Rate Monotonic Strategy), but with online rate modulation strategy. The rate modulation is performed using the value variances of behavior execution for the task. Because the values are based on natively uncertain sensor information, they are modeled using PDF (probability Density Function). As a rate modulation process, the range of the rate modulation is defined firstly by real-time constraints of RMS and discrete control stability of behaviors. With the allowable range, rate modulations are performed considering harmonic bases to maintain utilization bound without decrease. To evaluate the efficiency of the proposed rate modulation strategy, a simulation test is performed to compare the efficiency between the control architecture with the proposed strategy and previous one. A performance index with the formalization of propensity of resource allocation is proposed and utilized for the simulation test. To evaluate the appropriateness of the performance index, the performance index is compared with practical one through a practical simulation test.

• Asia pacific journal of information systems
• /
• 제20권2호
• /
• pp.103-124
• /
• 2010

Social communications using information and communication technologies (ICT) for social interactions have been making a significant impact on task performance in organizations. However, most of the existing studies on ICT (e.g., telephone and email) have only focused on technical improvement of communication efficiencies (e.g., information exchange and storage). In this paper, we claim that ICT may be another alternative source of knowledge creation that enables employees to work, find solutions, and achieve their goals faster and better. We investigate the impact of ICT in terms of both tasks and social aspects with knowledge creation as task performance. Also, we investigate the moderating effect of media synchronicity on these relationships. This study contributes to the understanding of contemporary communications media usage and its performance in organizations. We collected and analyzed survey data of 248 company employees, using PLS. The results indicate that task urgency and social influence directly affect ICT usage, and even knowledge creation. Also the media synchronicity moderates the relationship between the characteristics of a given task and ICT usage and the relationship between ICT usage and knowledge creation. Theoretical and practical implications of these findings are also discussed in the paper.

• 간호행정학회지
• /
• 제21권3호
• /
• pp.287-296
• /
• 2015

Purpose: Purpose of the study was to investigate task performance, importance, knowledge, and level of job stress and job satisfaction of nurses working in a hospital with no family or family paid auxiliary caregivers. Methods: Participants were 119 nurses working in hospitals with no guardians. The questionnaire contained 488 items: general characteristics, performance, importance, knowledge of nursing tasks, job stress and job satisfaction. Data were analyzed using descriptive statistics and Pearson correlation coefficients with SPSS/WIN 21.0. Results: Most frequently performed nursing tasks were patient nursing management and information management. Nursing tasks perceived as most important were medication and transfusion and nursing tasks with the highest knowledge were also medication and transfusion. Nursing task (subcategory) most frequently performed was oral medication. Nursing task (subcategory) perceived as most important was mental status observation and nursing task (subcategory) with the highest knowledge was vital sign check. Nurses' job stress was significantly associated with job satisfaction. The mean scores for nurses' job stress and job satisfaction were low. Conclusion: The results indicate that nurses working in hospitals with no guardians perform daily living assistance services more often than previously, and nurses need to be prepared to do these tasks.

• 한국감성과학회:학술대회논문집
• /
• 한국감성과학회 1999년도 춘계학술발표논문집 논문집
• /
• pp.127-132
• /
• 1999

Cardiovascular, respiratory and electrodermal responses to acute stress episodes modeled by combined presentation of intense white noise and performance of word recognition task with noise background were studied in 15 college students. Experimental procedure consisted in sessions with white noise, word recognition task presentation with noise background and test with noise background. Recorded physiological variables were analyzed in terms of their sensitivity to detect activation of sympathetic and parasympathetic branches of autonomic nervous system and thus reflect autonomic arousal level during shout-term stress-inducing experimental manipulations. It was shown that performance of effortful mental task with noise background elicited significant physiological responses typical for active coping behavior, namely electrodermal arousal and increased cardiovascular activity. this response profile was more profound as compared to white noise only or attending task in noise background. However, all physiological responses were mostly phasic, without long-term tonic changes, since almost all variables recovered to their initial baseline levels, suggesting that dominant autonomic mechanisms in transient acute stress episodes were of parasympathetic nature (withdrawal in stress with subsequent activation in restoration period), while sympathetic contribution was not long-lasting. Nevertheless, increased number of stressors and their longer exposure may result in higher profile of tonic sympathetic arousal and reduced functional role of vagal mechanisms in autonomic balance regulation.

• 한국멀티미디어학회논문지
• /
• 제22권9호
• /
• pp.1000-1010
• /
• 2019

Image semantic segmentation and dehazing are key tasks in the computer vision. In recent years, researches in both tasks have achieved substantial improvements in performance with the development of Convolutional Neural Network (CNN). However, most of the previous works for semantic segmentation assume the images are captured in clear weather and show degraded performance under hazy images with low contrast and faded color. Meanwhile, dehazing aims to recover clear image given observed hazy image, which is an ill-posed problem and can be alleviated with additional information about the image. In this work, we propose a deep multi-task network for simultaneous semantic segmentation and dehazing. The proposed network takes single haze image as input and predicts dense semantic segmentation map and clear image. The visual information getting refined during the dehazing process can help the recognition task of semantic segmentation. On the other hand, semantic features obtained during the semantic segmentation process can provide cues for color priors for objects, which can help dehazing process. Experimental results demonstrate the effectiveness of the proposed multi-task approach, showing improved performance compared to the separate networks.

• 인지과학
• /
• 제24권1호
• /
• pp.71-93
• /
• 2013

멀티태스킹은 이제 일상이 되었다. 자발적으로 하고 있던 일을 중단하고, 다른 것으로 전환하는 행동이 점점 쉬워지고 잦아지고 있다. 그러나 기존 연구에 따르면 과제전환은 대부분 인지적 비용을 야기시킬 뿐이다. 본 연구에서는 자발적 과제전환으로 인지적 이득을 얻을 수 있는지에 대해서 알아보고자 하였다. 이를 위해서 우선, 실험 1에서는 비슷한 성격의 두 과제를 할 때, 기존 연구와 마찬가지로 과제전환빈도와 수행도에 부적상관관계가 나타남을 확인하였다. 실험 2에서는 과제전환 가능 조건과 불가능 조건을 나누고, 개인의 멀티태스킹 선호도와 미디어 멀티태스킹 지수에 따라 각 과제의 수행도와 주관적 평가가 어떻게 달라지는지를 분석하였다. 실험 결과, 기존의 대부분 연구와 다르게 과제전환에서 항상 손실이 나타나는 것은 아니었다. 특히, 멀티태스킹 선호도가 높은 집단에서는 자발적 과제전환에서의 이득이 더 크게 나타났다. 기존의 과제전환 연구는 주로 손실이 발생하는 이유와, 그것을 줄이는 방법에 집중된 경향이 있었다. 그러나 본 연구는 과제전환 행동에서 발생하는 인지적 손실 뿐만 아니라 이득도 살펴보고자 하였다. 그 결과 참가자내 조건과 과제의 특성에 따라 손실과 이득이 차이 나는 것을 확인하였다.

• 대한공업교육학회지
• /
• 제35권2호
• /
• pp.159-181
• /
• 2010

이 연구는 고등학교 기술 가정과 '에너지와 수송기술' 단원에서 프로젝트법과 강의식 학습을 사용했을 때 여학생의 과제 수행 능력을 비교한 것이다. 과제 수행 능력은 하위 요인으로 정보 수집 능력, 과제 수행 계획 능력, 과제 수행 실행 능력 그리고 과제 수행 평가 능력을 갖는다. 경기도 소재 H 고등학교의 2개 학급의 여학생을 대상으로 실험한 결과는 다음과 같다. 첫째, 고등학교 기술 가정과 '에너지와 수송기술' 단원의 전반적인 과제 수행 능력에 있어서 프로젝트법을 적용한 집단이 강의식 학습을 적용한 집단보다 더 효과가 있었다. 즉 전체적으로는 프로젝트법이 강의식 학습 방법보다 학생들의 과제 수행 능력을 신장시키는데 더 효과가 있음이 검증되었다. 둘째, 고등학교 기술 가정과 '에너지와 수송기술' 단원에서 적용한 집단이 강의식 학습을 적용한 집단보다 과제 수행 능력의 하위 요소인 정보 수집 능력, 과제 수행 실행 능력에 있어서 더 효과적이었다. 그러나 또 다른 하위 요소인 과제 수행 계획 능력, 과제 수행 평가 능력에 있어서는 효과적이라고 할 수 없었다.

• 인지과학
• /
• 제16권3호
• /
• pp.189-197
• /
• 2005

본 연구에서는 $40\%$ 농도의 산소 공급에 따른 2·bark 과제 수행 능력, 혈중 산소 포화도, 심박동율의 변화를 관찰하고자 한다. 1명의 남자 (평균 $25.8\pm1.3$세)와 5명의 여자 (평균 $23.0\pm1.0$세) 대학생을 대상으로 두 가지 농도의 산소$(21\%,\;40\%)$를 공급하면서 2-back 과제를 수행하게 하였다. Rest1 (1분), 0-back Task (1분), 2-back Task (2분), Rest2 (4분)의 네 단계의 순서로 실험이 진행되었고, 전 단계에서 혈중 산소 포화도와 심박동율의 생리 신호가 측정되었다. $21\%$에 비해 $40\%$ 산소 농도에서 평균 정답률이 유의하게 증가하여, 고농도 산소 공급이 2-back 과제 수행 능력에 긍정적인 영향을 미친다는 사실을 도출할 수 있었다. $21\%$에 비해 $40\%$의 산소가 주어질 때 혈중 산소 포화도는 증가하였고 심박동율은 감소하였다. 이것은 인지 처리 수행 시 $21\%$에 비해 $40\%$의 산소 공급이 실제 혈중 산소 농도를 증가시켜 인지처리에 따른 뇌 활성화를 촉진시킬 수 있다는 사실을 의미하고, 공급된 과산소에 의해 심박동율이 감소한다는 사실을 의미하는 것이다.

• 한국콘텐츠학회논문지
• /
• 제18권3호
• /
• pp.101-113
• /
• 2018

실시간으로 데이터를 획득하고 평가하는 것이 중요한 군용 점검 장비와 같은 시스템에서는 운영체제 레벨에서 실시간 처리가 가능해야 한다. 기술의 발전으로 기존 장비를 휴대용 단말로 대체하려는 요구가 있으나, 안드로이드가 적용된 휴대용 단말은 실시간성이 요구되는 시스템에 적합하지 않다. 안드로이드에서는 가비지 컬렉션을 통해 가용 메모리를 확보하는데, 이 작업이 수행되는 동안 다른 태스크가 중단되어 특정 태스크의 주기성을 보장할 수 없다. 본 논문에서는 이를 해결하기 위해 안드로이드의 가비지 컬렉션 실행을 제어하는 구조를 설계 및 구현하였다. 실시간 작업이 필요한 시간 동안 가비지 컬렉션을 제어하여 실시간 성능을 보장하며, 안드로이드에 실시간 성능 보장을 위한 RTiK을 적용하였다. 성능 평가를 위해 5ms 주기 태스크의 호출 주기를 측정하였으며, 제어 이전에는 태스크의 34.31%만 주기가 보장되었으나, 제어를 통해 98.18%의 태스크 주기가 만족되어 안드로이드에 실시간성을 제공하였다.