• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2000년도 추계학술대회논문집 - 한국공작기계학회
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• pp.113-118
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• 2000

Collision free task planning for dual-arm robot which perform many subtasks in a common work space can be achieved in two steps : path planning and trajectory planning. Path planning finds the order of tasks for each robot to minimize path lengths as well as to avoid collision with static obstacles. A trajectory planning strategy is to let each robot move along its path as fast as possible and delay one robot at its initial position or reduce speed at the middle of its path to avoid collision with the other robot.

• Educational Technology International
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• 제10권2호
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• pp.145-166
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• 2009

The purpose of this study was to investigate why advance organizers (AO) are effective in promoting comprehension and mental model formation in terms of cognitive load. Two experimental groups: a concept-map AO group and a key-word AO group and one control group were used. This study considered cognitive load in view of Baddeley's working memory model: central executive (CE), phonological loop (PL), and visuo-spatial sketch pad (VSSP). The present experiment directly examined cognitive load using dual task methodology. The results were as follows: central executive (CE) suppression task achievement for the concept map AO group was higher than the key word AO group and control group. Comprehension and mental model construction for the concept map AO group were higher than the other groups. These results indicated that the superiority of concept map AO owing to CE load decrement occurred with comprehension and mental model construction in learning. Thus, the available resources produced by CE load reduction may have been invested for comprehension and mental model construction of learning contents.

• 한국전문물리치료학회지
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• 제21권4호
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• pp.34-39
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• 2014

The purpose of this study was to examine the effect of three cognitive tasks on gait at a preferred walking speed, and at a fast speed, using dual-task methodology. A total of 29 stroke patients participated in the study. All 29 subjects performed 2 motor tasks (10-meter walk task and timed up and go task each at a preferred and a fast speed) and three cognitive tasks [Stroop, word list generation (WLG), serial subtraction (SS)] under dual-task conditions [cognitive-motor interference (CMI)] in a randomized order. Gait speeds were measured in six different conditions. A repeated-measure analysis of variance was employed to compare the results of the Stroop training, WLG, and SS tasks during preferred and fast walking. A Bonferroni adjustment use for post hoc analysis. The level of statistical significance was set at ${\alpha}=.05$. A CMI effect occurred for performance of a 10-meter walking task at two different speed and a cognitive task (p<.05). Stroop had a significantly greater effect than SS and WLG (p<.05). The timed up and go task was affected when performed with fast walking speed during Stroop cognitive task (p<.05), but was not affected if performed with preferred walking speed during a cognitive task (p>.05). This study showed that CMI of Stroop can be used as a rehabilitation program for stroke patients.

• 한국생산제조학회지
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• 제23권6호
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• pp.580-589
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• 2014

Demands for automation in the cell production process of IT products are becoming increasingly sophisticated. In particular, the dual-arm robot has drawn attention as a solution because it has a flexibility and works similarly to humans. In this paper, we propose an automation system for cellular phone packing processes using two dual-arm robots. Applied robots are designed with specifications to meet the requirements of cellular phone packing jobs. In addition, a robotic cell production system is proposed by applying a method of task allocation for efficient packing of cellular phones. Specifically, a task is assigned to reduce takt-time and to avoid collision between two robots. Finally, we discuss some experimental results that include the packing job of five unit boxes with seven kinds of accessories.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2018년도 춘계학술대회
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• pp.59-60
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• 2018

부산신항의 환적화물 처리물량은 지속적으로 늘어나 전체 물동량의 50%를 넘기고 있지만 작업자의 경험에 의존한 작업의 순서 결정에 따라 효율적인 환적화물 운송이 이루어지고 있다고 보기 힘들다. 특히, 외부 트럭이 필요한 경우가 많은 타부두 환적은 작업 상황에 따라 차량 대기로 인한 과도한 혼잡으로 물류비 증가와 사회적 비용이 발생하게 된다. 이 문제를 해결하기 위한 방법 중 하나는 트럭의 단일 운송을 최소화하고 작업을 마친 트럭을 다른 작업에 투입하여 활용하는 듀얼 사이클 운송을 최대화하는 것이다. 이에 따라, 본 연구에서는 컨테이너 터미널간 환적화물의 듀얼 사이클 운송을 위한 방안에 대해 연구하고자 한다.

• 로봇학회논문지
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• 제12권4호
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• pp.441-447
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• 2017

Robot arms are being increasingly used in various fields with special attention given to unmanned systems. In this research, we developed a high payload dual-arm robot, in which the forearm module is replaceable to meet the assigned task, such as object handling or lifting humans in a rescue operation. With each forearm module specialized for an assigned task (e.g. safety for rescue and redundant joints for object handling task), the robot can conduct various tasks more effectively than could be done previously. In this paper, the design of the high payload dual-arm robot with replaceable forearm function is described in detail. Two forearms are developed here. Each of forearm has quite a different goal. One of the forearms is specialized for human rescue in human familiar flat aspect and compliance parts. Other is for general heavy objects, more than 30 kg, handling with high degree of freedom more than 7.

• 한국국방경영분석학회지
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• 제11권1호
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• pp.33-46
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• 1985

This study develops a scientific method in pilot selection by analysing a divided attention performance between the successful pilots and the failures in a flight training course. To measure the divided attention performance, Dual Task Method is used in which the primary task is a tracking task while the secondary tasks are, 1. short-term memory task 2. choice reaction task 3. judgement task. Result shows that the performance of the pilots is significantly better (p < 0.1) than that of the failures in divided attention performance. In addition, the differences in the divided attention performance between the two groups are increased in proportion to the difficulty of the task and especially in the short term memory, the increment is most dramatic.

• 한국전문물리치료학회지
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• 제15권2호
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• pp.11-19
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• 2008

Studies of attentional focus effects, have shown that the performer's attentional focus plays an important role in the performance and learning of motor tasks. We examined the influence of attentional focus on the performance of dual tasks (a postural task and a suprapostural task) and used electromyography (EMG) to examine whether the differences between external and internal focus were also manifest at the neuromuscular level. The subjects (n=40) stood on a balance board (postural task) and held a bar horizontally (suprapostural task). All of the subjects performed under different attentional focus conditions: external (balancer on balance board) or internal (feet) focus on the postural task, and external (balancer on bar) or internal (hand) focus on the suprapostural task. The mean displacement velocity of the bar and the percent reference voluntary contraction (%RVC) of the biceps brachii were reduced when the subjects adopted an external focus on the suprapostural task (p<.05). In addition, the mean displacement velocity of the balance board and %RVC of the tibialis anterior were reduced when the subjects adopted an external focus on the postural task (p<.05). When the subjects adopted an external focus on the suprapostural task, the mean displacement velocity of the balance board and %RVC of the tibialis anterior were also reduced (p<.05). When the subjects' attentional focus was on the postural task, there were no differences in the mean displacement and %RVC of the biceps brachii between attentional focuses. The performance of each task was enhanced when subjects focused on the respective task. The suprapostural task goals had a stronger influence on postural control than vice versa. These results reflect the propensity of the motor system to optimize control processes based on the environmental outcome, or movement effect, that the performer wants to achieve.

• 한국자동차공학회논문집
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• 제9권6호
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• pp.103-111
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• 2001

During cold-start period, the reduction of exhaust emissions is a challenging task. To decrease harmful gaseous substances such as HC, it is necessary to realize a fast catalyst warm-up. In this study, the performance of dual pipe exhaust system have been carried out through different test mode. From measurement of gas temperature and HC concentration, the following conclusions were derived ; 1) Compared with single pipe, dual pipe exhaust system remarkably increase temperature of exhaust gas going through M.C.C(Main Catalytic Converter). 2) W.C.C.(Warm-up Catalytic Converter) also decreases HC emission. To reduce HC emission, it is helpful to use W.C.C. as well as dual pipe exhaust system. 3) Using finite element method, it is shown that inner parts have much higher distribution of temperature than outer parts.

• 한국문헌정보학회지
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• 제48권2호
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• pp.379-398
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• 2014

This pilot study explored the effect of mental demand on a Web searcher's thoughts, emotions, efforts, and performance in Web searches in order to address whether or not there is any difference between searchers exposed to mental demand manipulation and searchers not exposed. Research data were collected via think-aloud protocol (TAP) with a dual-task in experiments and interviews with 10 subjects who participated in this study. For the searcher's thoughts, relevance judgment was found to be hindered by mental demand. For the searcher's emotions, the experimental group was more frustrated than the control group. With respect to the searcher's efforts, searchers for the experimental group with mental demand manipulation were more likely to spend more time, make fewer queries, and visit fewer pages but work harder to find more relevant information that they needed. Lastly, with regard to the searcher's performance, it is likely that performance was highly dependent upon the completion of the search tasks for both groups. The NASA-TLX six components and cognitive load scores of searchers did not make a significant difference in the outcome. The findings support the use of a dual-task methodology as a promising approach for the assessment of cognitive load induced by complex Web searches.