• The Journal of Korea Robotics Society
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• v.8 no.3
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• pp.186-196
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• 2013

Since its introduction (e.g., [4, 6]), virtual coupling technique has been de facto way to connect a haptic device with a virtual proxy for haptic rendering and control. However, because of the single dependence on spring-damper feedback action, this virtual coupling suffers from the degraded transparency particularly during contact tasks when large device/proxy-forces are involved. In this paper, we propose a novel virtual coupling technique, which, by utilizing passive decomposition, reduces device-proxy position deviation even during the contact tasks while also scaling down (or up) the apparent inertia of the coordinated device-proxy. By doing so, we can significantly improve transparency between multiple degree of freedom (possibly nonlinear) haptic device and virtual proxy. In other to use passive decomposition, disturbance observer of [3] is adopted to estimate human force with some dead-zone modification to avoid "winding-up" force estimation in the presence of device torque saturation. Some preliminary experimental results are also given to illustrate efficacy of the proposed technique.

• The Journal of the Korea Contents Association
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• v.20 no.7
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• pp.282-291
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• 2020

This study was conducted to explore the effects of students' problem solving ability according to the level of structuring of curriculum tasks in PBL activities. The study was conducted on 60 college students in curriculum classes. Problem solving ability was measured at the beginning of the semester. And after the midterm exam, PBL activities were conducted. 30 experimental groups performed unstructured tasks. 30 comparison groups performed semi-structured problems. After the task was completed, problem solving ability was measured at the end of the semester. Collected data were analyzed using ANCOVA. As a result, it was verified that the experimental group had a statistically significant improvement in information collection, evaluation, and feedback level than the comparative group.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.7
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• pp.53-57
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• 2006

PID controller is widely uesd as automatic equipment for industry. However when a system has various characters of intermittence or continuance, a new parameter decision for accurate control is a hard task. As method of solving this problem, in this paper, a Neural Network gain automatic regulator as PID controller functions is presented. A property feedback control gain of system is decided by a rule of Delta learning. The function of proposed automatic Neural Network gain regulator is verified by speed control experiment results of Induction Motor.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1887-1891
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• 2005

Despite significant advances in multimedia transferring technologies in various fields of robotics, it is sometimes quite difficult for the operator to fully understand the context of 3D remote environments from 2D image feedback. Particularly, in the remote control of mobile robots, the recognition of the object associated with the task is very important, because the operator has to control the robot safely in various situations not through trial and error. Therefore, it is necessary to provide the operator with 3D volumetric models of the object and object-related information as well such as locations, shape, size, material properties, and so on. Thus, in this paper, we propose a vision-based human interface system that provides an interactive, information-rich map through network-based information brokering. The system consists of an object recognition part, a 3D map building part, a networked knowledge base part, and a control part of the mobile robot.

• Journal of Institute of Control, Robotics and Systems
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• v.16 no.12
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• pp.1233-1240
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• 2010

In the flat panel display and semiconductor industries, the visual alignment system is considered as a core technology which determines the productivity of a manufacturing line. It consists of the vision system to extract the centroids of alignment marks and the stage control system to compensate the alignment error. In this paper, we develop a Kalman filter algorithm to estimate the alignment mark postures and propose a coarse-fine alignment control method which utilizes both original fine images and reduced coarse ones in the visual feedback. The error compensation trajectory for the distributed joint servos of the alignment stage is generated in terms of the inverse kinematic solution for the misalignment in task space. In constructing the estimation algorithm, the equation of motion for the alignment marks is given by using the forward kinematics of alignment stage. Secondly, the measurements for the alignment mark centroids are obtained from the reduced images by applying the geometric template matching. As a result, the proposed Kalman filter based coarse-fine alignment control method enables a considerable reduction of alignment time.

• Journal of Institute of Control, Robotics and Systems
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• v.14 no.11
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• pp.1117-1123
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• 2008

This paper implements dual-kernel system using standard Linux and real-time embedded Linux for the real-time control of intelligent robot systems. Such system provides more useful services including standard Linux thread that is easy to implement complicated tasks and real-time tasks for the deterministic response to velocity control. Here, an open source real-time embedded Linux, XENOMAI, is ported on embedded target board. And for interfacing with motor controller we adopted a real-time serial device driver. The real-time task was implemented with a priority to keep the cyclic control command for trajectory control. In order to validate deterministic response of the proposed system, the performance measurement of the delay in performing trajectory control with feedback loop is evaluated with non real-time standard Linux. The proposed software architecture is anticipated to take advantage of features in both standard Linux and real-time operating systems for the intelligent robot systems.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.6 no.1
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• pp.37-43
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• 2012

We conducted a user-centered usability testing on the Android-based Mobile Augmentative Alternative Communication(AAC) Software. In this paper, we examined functionality, satisfaction, and ease of information searching for a specific function using a task scenario, and we investigated appropriateness of development purposes, contents, instructional strategies, usability, functions of management mode, and user interface of the mobile AAC to the communication needs of children who are nonverbal. We also examined user requirements, preference, satisfaction, and other personal opinions for the mobile AAC using an open feedback. In addition, we investigated users' preference for the size of mobile devices using 4.3", 5.0", and 7.0" mobile devices.

• Knowledge Management Research
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• v.2 no.1
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• pp.25-44
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• 2001

There are two types of organizational knowledge in terms of its creation process: experiential and analytical knowledge. The experiential knowledge is created by repetitive experiences of an individual or team through task execution, while the analytical knowledge is acquired by analyzing accumulated data or information in the organization. The experiential knowledge often remains tacit or implicit in the organization because it is primarily acquired at an individual or team level. Therefore, the issue on the experiential knowledge is to share it actively within the organization. On the other hand, the analytical knowledge is explicit in its nature since it is extracted from data or information. Thus, it is important to guide a systematic creation of the analytical knowledge rather than encourage to share it. The current trend of "knowledge management" mainly focuses on the experiential knowledge - know-how, idea, case, etc - and neglects another important knowledge in the organization. i. e., analytical knowledge. This paper tries to shed a new light on the "knowledge management" arena by introducing rather new perspective in the concept of knowledge. The purpose of this study is to identify the factors affecting the analytical knowledge creation in the organization. We conducted an exploratory case study of three companies with a previously defined research framework and found some critical factors for the analytical knowledge creation. They are "organizational resource", "effectiveness of feedback process", "data source management", and "experimental mind set". Finally, we proposed research model and propositions regarding the analytical knowledge creation in the organization.

• Journal of Korea Society of Industrial Information Systems
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• v.11 no.5
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• pp.181-189
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• 2006

The ubiquitous technology has requested many changes both to the way of learning and to the way of convergence learning content development. However, until now most of e-Learning contents can not meet the requirements of technology convergence and are not developed from the user's perspectives. In this paper, we focus a convergence learning model that is learner-oriented structure, active use of formal and informal learning. Furthermore, examine carefully importance about task analysis, storytelling, and feedback design strategy of learning management system for e-Learning content development. In this context, this paper suggests the effective e-Learning content development method in a convergence era.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.4 s.97
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• pp.205-212
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• 1999

A three dimensional binary parallel robot manipulator uses actuators which have only two stable states and its structure is variable geometry truss. As a result, it has a finite number of states and fault tolerant mechanism because of kinematic redundancy. This kind of robot manipulator has some advantages compared to a traditional one. Feedback control is not required, task repeatability can be very high, and finite state actuators are generally inexpensive. Because the number of states of a binary robot manipulator grows exponentially with the number of actuators it is very difficult to solve and inverse kinematic problem. The goal of this paper is to develop an efficient algorithm to solve an inverse kinematic problem of three dimensional binary parallel robot manipulator using a backbone curve when the number of actuators are too much. We first derive the coordinate transformations associated with a three degree of freedom in-parallel actuated robot manipulator. The backbone curve is generated optimally by considering the maximum roll and pitch angles of the robot manipulator configuration and length of link. Then, the robot manipulator is fitted along the backbone curve with some criterion.