• Journal of Biomedical Engineering Research
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• v.27 no.6
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• pp.323-331
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• 2006

The purpose of this study was to investigate the effect of performing a cognitive task during treadmill walking on the stride rate variability. Ten university students(age $24.0{\pm}0.25$, height $172{\pm}3.1cm$, weight $66{\pm}5.3kg$) were participated in dual task experiments which consist of both walking alone and walking with a cognitive task. Two-back task was selected for the cognitive task since it did not have learning effect during the experimental procedure.3D motion analysis system was used to measure subject's position data by changing walking speed with 4.8, 5.6, 6.4, 6.8, and 7.2 km/hr. Stride rate was calculated by the time between heel contact and heel contact. Accuracy rate of a cognitive task during walking, coefficient of variance, allometric scaling methods and Fano factor were used to estimated the stride rate variability. As the walking speed increased, accuracy rate decreased and the logarithmic value of Fano factor increased which showed the statistical difference. Thus it can be concluded that the gait control mechanism is distracted by the secondary attention focus which is the cognitive task ie. two-back task. Further study is needed to clarify this by increasing the number of subject and experiment time.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.23 no.7
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• pp.1-7
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• 2009

The research aims at providing data needed for planning the lighting of a study room by comparing the lighting environments of study rooms for urban and rural juveniles. The subject of the research was 300 students in middle schools in Daegu and Checngdo-gun, Gyeongsangbuk-do (Daegu 150 houses and Cheongdo 150 houses), and their study rooms were examined. The following is the result of the research. First, rural students stayed more time in their study room than urban students. The task that rural students (studying) and urban students (studying and using computer) all did in their study room was mainly visual work Second, although the sizes of rural study rooms were bigger than those of urban study rooms, urban study rooms had more light sources than rural study rooms. In the rate that of having a task lighting, the city(87.1[%]) was higher than the country (45.7[%]). However, the rate of using a task lighting was lot high in both the city and the country. Third, the result that compared the average values of illuminations on desk planes was that the average value of the city was 3.4 times higher than that of the country. Also, the average value of the country did not meet the standard illumination of Korean industrial standards (KS). In particular, it did not reach the lowest standard. The result is related with that only 52[%] of students who had a task lighting used it. Finally, the satisfaction of lighting environment in the city was generally higher than the country. Especially, although the country had a low illumination, the user showed a high satisfaction. It indicates that people living in the country need to understand about the needs of illumination.

• Journal of Digital Convergence
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• v.10 no.6
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• pp.275-281
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• 2012

This research proposes the method to develop the recommendation system of automobile parts using task ontology technology. The proposed intelligent recommendation system is designed to learn the assembly process of automobile parts and the automobile parts are composed by ontology method for the recommendation of the parts. Using hierarchical taxonomy based on is-a relationship, the relationship between each part that makes up automotive engine was set. Each part has each different weighted value according to the knowledge of automobile experts. The weighted value is created by the number of selection that the users of the automobile recommendation system select while using the system and the final value calculated by the multiplication of the weighted value, which is recorded within the system. As a result, the users can easily identify which factor in which part is important by the output in the order of the priority. The intelligent recommendation system for automobile parts is a system to inform of the assembly, the usage and the importance of automobile parts without any specialized knowledge by expressing the parts that are closely related with the applicable parts when selecting any part on the basis of the generated data for the automobile parts that are difficult to access by users.

• International Journal of Control, Automation, and Systems
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• v.6 no.6
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• pp.904-914
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• 2008

An action-selection-mechanism(ASM) has been proposed to work as a fully connected finite state machine to deal with sequential behaviors as well as to allow a state in the task program to migrate to any state in the task, in which a primitive node in association with a state and its transitional conditions can be easily inserted/deleted. Also, such a primitive node can be learned by a shortest path-finding-based reinforcement learning technique. Specifically, we define a behavioral motivation as having state-dependent value as a primitive node for action selection, and then sequentially construct a network of behavioral motivations in such a way that the value of a parent node is allowed to flow into a child node by a releasing mechanism. A vertical path in a network represents a behavioral sequence. Here, such a tree for our proposed ASM can be newly generated and/or updated whenever a new behavior sequence is learned. To show the validity of our proposed ASM, experimental results of a mobile robot performing the task of pushing- a- box-in to- a-goal(PBIG) will be illustrated.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.1587-1592
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• 2003

There are three kinds of singularity in controlling redundant manipulators. Kinematic, algorithmic and representation singularities are those. If manipulators fall into any singularity without proper action to avoid it, the control system must go away from our desire, and we can meet a dangerous situation. Hence, we have to deal the singularities very carefully. In this paper, we describe an on-line solution for avoiding the occurrence of both algorithmic and kinematic singularities in task-priority based kinematic controllers of robotic manipulators. Representation singularity can be easily avoided by using proper representation algorithm, so, in this paper, we only consider kinematic and algorithmic singularities. The proposed approach uses a desired task reconstruction and a successive task projection in order to maintain the measure for singularity over a user defined minimum value. It shows a gain in performance and a better task error especially when working in proximity of singular configurations. It is particularly suitable for autonomous systems where an off-line trajectory control scheme is often not applicable. The advantage and performance of the proposed controller is verified by simulation works. And, the experiment with real manipulator is remaining for the future works.

• Journal of Korean Academy of Nursing Administration
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• v.16 no.4
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• pp.446-454
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• 2010

Purpose: This study was conducted to compare job satisfaction, self-esteem, and nursing task performance between registered nurses (RN) and nurse assistants (NA) in long-term care hospitals. Method: The sample consisted of 203 nursing personnel (RN 99 and AN 104), who were working in one of 5 long-term care hospitals in 5 different areas. Data were collected by structured questionnaires from March 15 to April 30, 2010, and analyzed using the descriptive statistics, independent t-test, One-way ANOVA, and Pearson correlation coefficients with SPSS/Win 17.0 program. Result: There was no significant difference between nurses and nurse assistants in job satisfaction and self-esteem. But nurses had higher levels of nursing task performance than nurse assistants. Conclusions: These findings demonstrate the necessity of developing programs that will help to improve job satisfaction and self-esteem in nurses and nursing task performance in nurse assistants. Strategies need to be developed to maximize the value of the existing workforce without impacting on the quality of care delivered.

• Korean Journal of Social Welfare
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• v.62 no.4
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• pp.59-77
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• 2010

The purpose of this paper is to suggest the implications of volunteering's task design and the volunteer's placement that make the motive-benefit matching from the functional perspective of motivation. For this study, we conducted a multi-regression analysis to examine the impact of the volunteer motivation on task satisfaction and retention will. Results showed that first, volunteers' most important motive for volunteering was social motive, followed by enhancement, value. Secondly, each motive influenced the task satisfaction and retention will of volunteers differentially. The practical implications of these findings were discussed.

• Journal of the Korea Institute of Military Science and Technology
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• v.26 no.2
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• pp.188-196
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• 2023

In the future battlefield centered on the concept of mosaic warfare, the need for an unmanned combat system will increase to value human life. It is necessary for Multiple/Heterogeneous Unmanned Combat Systems to have suitable mission planning method in order to perform various mission. In this paper, we propose the MTSR model for mission planning of the unmanned combat system, and introduce a method of identifying a task by a combination of services using a request operator and a method of allocating resources to perform a task using the requested service. In order to verify the performance of the proposed task-resource matchmaking algorithm, simulation using occupation scenarios is performed and the results are analyzed.

• Journal of the Ergonomics Society of Korea
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• v.25 no.2
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• pp.11-22
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• 2006

The muscular-skeletal disorders(MSDs) that have become a major issue recently in Korean industrial safety area are mainly caused by manual material handling task. The objective of this study is to provide scientific data for the establishment of work safety standard for Korean workers through the experiments of lifting task under various conditions, in order to prevent the muscular-skeletal disorders in the industrial work site. Eight male college students were recruited as participants. Three different lifting frequencies(1, 3, 5 lifts/min) and three twisting angles(including the sagittal plane and two asymmetric angles; i.e., 0°, 45°, 90°) for symmetric and asymmetric tasks, respectively, with three lifting range from floor to knuckle height, knuckle to shoulder, floor to shoulder height for one hour's work shift using free style lifting technique were studied. The maximum acceptable weight of load(MAWL) was determined under the different task conditions, and the oxygen consumption, heart rate, and RPE were measured or recorded while subjects were lifting their MAWLs. The results showed that: (1) The MAWLs were significantly decreased as the task frequency and task angle increased.; (2) The heart rate, oxygen consumption, RPE significantly increased with an increase in lifting frequency although maximum acceptable weight of lift decreased.; (3) The highest heart rate and oxygen consumption was recorded at the lifting range of floor to shoulder, followed by floor to knuckle and knuckle to shoulder.; (4) The RPE value showed that subjects perceived more exertion at the high frequency rate of lifting task and lifting range of floor to shoulder height. (5) The modeling for MAWL using isometric strength, task angle and lifting frequency were developed. It is expected that use of the results provided in this study may prove helpful in reducing MMH hazards, especially from lifting tasks for Korean, and can be used as a basis for pre-employment screening.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.9
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• pp.4103-4121
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• 2018

Quality of Service (QoS) awareness is recognized as a key point for the success of Internet of Things (IOT).Realizing the full potential of the Internet of Things requires, a real-time task scheduling algorithm must be designed to meet the QoS need. In order to schedule tasks with diverse QoS requirements in cloud environment efficiently, we propose a task scheduling strategy based on dynamic priority and load balancing (DPLB) in this paper. The dynamic priority consisted of task value density and the urgency of the task execution, the priority is increased over time to insure that each task can be implemented in time. The scheduling decision variable is composed of time attractiveness considered earliest completion time (ECT) and load brightness considered load status information which by obtain from each virtual machine by topic-based publish/subscribe mechanism. Then sorting tasks by priority and first schedule the task with highest priority to the virtual machine in feasible VMs group which satisfy the QoS requirements of task with maximal. Finally, after this patch tasks are scheduled over, the task migration manager will start work to reduce the load balancing degree.The experimental results show that, compared with the Min-Min, Max-Min, WRR, GAs, and HBB-LB algorithm, the DPLB is more effective, it reduces the Makespan, balances the load of VMs, augments the success completed ratio of tasks before deadline and raises the profit of cloud service per second.