• Journal of the Korean Institute of Telematics and Electronics B
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• v.31B no.1
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• pp.41-48
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• 1994

The conventional resolved motion control is not applicable for the control of robots on the spacecraft on account of the floating base of the robots. When the robots perform the assembly or repair operations, the position and attitude of the base satellite are disturbed by the reaction force/moment caused by the robot motion. This reaction will cause error on the robot. motion. Therefore, we define a new type of Jacobian(Extended Jacobian) to minimize the effects of reaction on the accuracy of the robot performing assembly or repair operations. In this paper, we utilize the redundancy of the closed chain system to minimize the effects of the robot motion on the position and attitude of spacecraft. This will results in the accurate assembly and repair operations by the robot.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.576-579
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• 1997

In order to repair sewage pipes, it is necessary to dig up the damaged sewage pipes, which results in traffic jams. Since digging up the pipes takes too much time and cost, this method is inefficient. So, in stead of digging up the damaged pipes, a robot is sent down to the pipe to do the repair works. For big pipes, human workers go into the pipe and do to repair works, but for small pipes, it is impossible for human worker to go inside the pipe. In this case, mobile robots have used. The procedures for repairing pipes are as follows : First, the condition of the sewage pipes is observed by a robot. Second, appropriate steps for repair are determined according to the types of the damage. While repairing procedures, a newly-developed packer is sent into the sport to be repaired inside the pipe. Then, the packer is filled with air by a V-shaped wrinkel pipe. This makes the packer inflates uniformly and adhere closely to the inside wall of the pipe in large area. This increases the area that can be repaired. Therefore, the newly-developed packer will be very helpful for sewage pipe repair works.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.6
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• pp.2760-2769
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• 2011

An intelligent autonomous robot generates a plan to achieve a goal. A plan is a sequence of robot actions that accomplish a given mission by being successfully executed. However, in the complex and dynamic real world, a robot may encounter unexpected situations and may not execute its planned actions any more. Therefore, an intelligent autonomous robot must prepare an efficient handling process to cope with these situations to successfully complete a given mission. Plan repair with milestone states is an efficient method to cope with the situation. It retains the advantages of other plan repair procedures. This paper proposes a regressive method of formulating milestone states and a method of assigning weighting values on conditions that compose a milestone state. The task to repair a plan may employ the weighting values as its job priority. The regressive method formulates less complex milestone states and leads to the conditions of a milestone state to take pertinent weighting values for an efficient handling procedure to repair a plan with milestone states.

• Journal of Institute of Control, Robotics and Systems
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• v.19 no.5
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• pp.435-441
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• 2013

A swarm robot system consists of with multiple mobile robots, each of which is called an agent. Each agent interacts with others and cooperates for a given task and a given environment. For the swarm robotic system, the loss of the entire work capability by malfunction or damage to a single robot is relatively small and replacement and repair of the robot is less costly. So, it is suitable to perform more complex tasks. The essential component for a swarm robotic system is an inter-robot collaboration strategy for teamwork. Recently, the swarm intelligence theory is applied to robotic system domain as a new framework of collective robotic system design. In this paper, FA (Firefly Algorithm) which is based on firefly's reaction to the lights of other fireflies and their social behavior is employed to optimize the group behavior of multiple robots. The main application of the firefly algorithm is performed on path planning of swarm mobile robots and its effectiveness is verified by simulations under various conditions.

• Korean Journal of Cognitive Science
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• v.33 no.4
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• pp.205-228
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• 2022

This study aimed to confirm the effect of social and relational behavior types of robots on human cognition in human-robot interaction. In the experiment, the participants evaluated trust in robots by watching a video on the robot Nao interacting with a human, in which the robot made an error and then made an effort to restore trust. The trust recovery behavior was set as three conditions: an internal attribution in which the robot acknowledges and apologizes for an error, a condition in which the robot apologizes for an error but attributes it externally, and a non-action condition in which the robot denies the error itself and does not take any action for the error. As the result, in all three cases, the error was perceived as less serious when the robot apologized than when it did not, and the ability of the robot was also highly evaluated. These results provide evidence that human attitudes towards robots can respond sensitively depending on the robot's behavior and how they overcome errors, suggesting that human perception towards robots can change. In particular, the fact that robots are more trustworthy when they acknowledge and apologize for their own errors shows that robots can promote positive human-robot interactions through human-like social and polite behavior.

• Journal of Industrial Technology
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• v.20 no.A
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• pp.229-238
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• 2000

Simulation analysis for an auto body manufacturing system has been performed in this study. The major goal is to figure out the condition yielding the production rate, 70 per hour. It is, however, very difficult to maintain this rate due to inherent system factors such as machine failure rates, machine repair rates, number of carriers between manufacturing lines(shops), carrier speed etc. We first carefully examined the system and developed a simulation model using ARENA. We then applied statistical experimental design concepts for performance analysis. Our results indicate that the buffer size of 30 and quick repair of failed robots are required for the desired production rate. Other factors, on the other hand, are seen to have minor effects on the throughput. The approach taken in this study and the results obtained may provide a practical guideline for performance analysis and thus be applied without trepidation for similar cases.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.21 no.2
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• pp.177-186
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• 2021

This paper aims to show that cooperative robots, which have only been used in manufacturing sites, are expanding their scope of use in daily living spaces due to the expansion of non-face-to-face services. By combining robots and IoT technologies in terms of diversifying services in daily life and customized service areas, it is expected that the general public will also have easy access to smart technologies, and these technologies will be used in more areas. The robot barista system will provide customers with the services they want, monitoring, maintenance, and management of the system, making this paper convenient for customers, as well as managers who run stores, maintenance and repair, and engineers who design the system. This paper attempts to demonstrate this through a structure called Robopresso.

• Fashion & Textile Research Journal
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• v.24 no.6
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• pp.667-685
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• 2022

This paper aims to investigate 4D printing materials for soft robots. 4D printing is a targeted evolution of the 3D printed structure in shape, property, and functionality. It is capable of self-assembly, multi-functionality, and self-repair. In addition, it is time-dependent, printer-independent, and predictable. The shape-shifting behaviors considered in 4D printing include folding, bending, twisting, linear or nonlinear expansion/contraction, surface curling, and generating surface topographical features. The shapes can shift from 1D to 1D, 1D to 2D, 2D to 2D, 1D to 3D, 2D to 3D, and 3D to 3D. In the 4D printing auxetic structure, the kinetiX is a cellular-based material design composed of rigid plates and elastic hinges. In pneumatic auxetics based on the kirigami structure, an inverse optimization method for designing and fabricating morphs three-dimensional shapes out of patterns laid out flat. When 4D printing material is molded into a deformable 3D structure, it can be applied to the exoskeleton material of soft robots such as upper and lower limbs, fingers, hands, toes, and feet. Research on 4D printing materials for soft robots is essential in developing smart clothing for healthcare in the textile and fashion industry.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38C no.12
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• pp.1170-1178
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• 2013

Thanks to various benefits, low-cost real-time communication networks so called fieldbus have been widely used in many industrial applications including military systems, such as aircrafts, submarines, and robots. This paper presents a reliability analysis of dual-channel CAN(Controller Area Network) fieldbus which is used for controlling various equipment of submarine combat system. A submarine combat system playing a critical role to the success of missions and survivability consists of various devices including sensors/actuators and computers. Since a communication network for submarine combat system must satisfy an extremely high level of reliability, a dual channel technique is commonly adopted. In this paper, a Petri Net based reliability model for dual-channel CAN is discussed. A reliability model called generalized stochastic Petri Nets (GSPN) is built by utilizing the information on physical faults with CAN. The effectiveness of the proposed model is analyzed in terms of unreliability with respect to failure rate and repair rate.

• Journal of Chest Surgery
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• v.41 no.5
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• pp.598-604
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• 2008

Background: The improvements in endoscopic equipment and surgical robots has encouraged the performance of minimally invasive cardiac operations. Yet only a few Korean studies have compared this procedure with the sternotomy approach. Material and Method: Between December 2005 and July 2007, 48 patients (group A) underwent minimally invasive cardiac surgery with AESOP through a small right thoracotomy. During the same period, 50 patients (group B) underwent conventional surgery. We compared the operative time, the operative results, the post-operative pain and the recovery of both groups. Result: There was no hospital mortality and there were no significant differences in the incidence of operative complications between the two groups. The operative $(292.7{\pm}61.7\;and\;264.0{\pm}47.9min$, respectively; p=0.01) and CPB times ($128.4{\pm}37.6\;and\;101.7{\pm}32.5min$, respectively; <0.01) were longer for group A, whereas there was no difference between the aortic cross clamp times ($82.1{\pm}35.0\;and\;87.8{\pm}113.5min$, respectively; p=0.74) and ventilator times ($18.0{\pm}18.4\;and\;19.7{\pm}9.7$ hr, respectively; p=0.57) between the groups. The stay on the ICU $(53.2{\pm}40.2\;and\;72.8{\pm}42.1hr$, respectively; p=0.02) and the hospitalization time ($9.7{\pm}7.2\;and\;14.8{\pm}11.9days$, respectively; p=0.01) were shorter for group A. The Patients in group B had more transfusions, but the difference was not significant. For the overall operative intervals, which ranged from one to four weeks, the pair score was significantly lower for the patients of group A than for the patients of group B. In terms of the postoperative activities, which were measured by the Duke Activity Scale questionnaire, the functional status score was clearly higher for group A compared to group B. The analysis showed no difference in the severity of either post-repair of mitral ($0.7{\pm}1.0\;and\;0.9{\pm}0.9$, respectively; p=0.60) and tricuspid regurgitation ($1.0{\pm}0.9\;and\;1.1{\pm}1.0$, respectively; p=0.89). In both groups, there were no valve related complications, except for one patient with paravalvular leakage in each group. Conclusion: These results show that compared with the median sternotomy patients, the patients who underwent minimally invasive surgery enjoyed significant postoperative advantages such as less pain, a more rapid return to full activity, improved cosmetics and a reduced hospital stay. The minimally invasive surgery can be done with similar clinical safety compared to the conventional surgery that's done through a median sternotomy.