• 산업경영시스템학회지
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• 제26권3호
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• pp.18-23
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• 2003

This research deals with an object-oriented task description(OOTD) method to solve problems such as being hard to understand and a lack of description in existing task description methods. The OOTD method includes an object-oriented task structure diagram and an object-oriented task attribute diagram. The former shows some relationship between a task and a derived task. The latter includes important attributes to define each task. Finally, a sample case is introduced to show how efficient these two diagrams are for the task description.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1994년도 추계학술대회 논문집
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• pp.559-564
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• 1994

Recently, a visual servoing for an eye-in-hand robot has become an interesting problem. A distance between a camera and a task object is very useful information for visual servoing. In the previous works for visual servoing, the distance can be obtained from the difference between a reference and a measured feature value of the object such as area on image plane. However, since this feature depends on the object, the reference feature value must be changed when other task object is taken. To overcome this difficulty, this paper presents a novel method for visual servoing. In the proposed method, a blur is used to obtain the distance. The blur, one of the most important features, depends on the focal length of camera. Since it is not affected by the change of object, the reference feature value is not changed although other task object is taken. In this paper, we show a relationship between the distance and the blur, and define the feature jacobian matrix based on camera defocusing to operate the robot. A series of experiments is performed to verify the proposed method.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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• pp.720-723
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• 1997

This paper presents a cooperative control method for multiple robots. This method is based on local sensors. The proposed method integrates all information obtained by local perception through a set of sensors and generates commands without logical conflicts in designing control logic. To control multiple robots effectively, a global control strategy is proposed. These methods are constructed by using AND/OR logic and transition firing sequences in Petri nets. To evaluate these methods, the object-searching task is introduced. This task is to search an object like a box by two robots and consists of two sub-tasks, i.e., a wall tracking task and a robot tracking task. Simulation results for the object-searching task and the wall tracking task are presented to show the effectiveness of the method.

• 한국자동차공학회논문집
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• 제24권2호
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• pp.127-136
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• 2016

The camera based object detection systems should satisfy the recognition performance as well as real-time constraints. Particularly, in safety-critical systems such as Autonomous Emergency Braking (AEB), the real-time constraints significantly affects the system performance. Recently, multi-core processors and system-on-chip technologies are widely used to accelerate the object detection algorithm by distributing computational loads. However, due to the advanced hardware, the complexity of system architecture is increased even though additional hardwares improve the real-time performance. The increased complexity also cause difficulty in migration of existing algorithms and development of new algorithms. In this paper, to improve real-time performance and design complexity, a task scheduling strategy is proposed for visual object tracking systems. The real-time performance of the vision algorithm is increased by applying pipelining to task scheduling in a multi-core processor. Finally, the proposed task scheduling algorithm is applied to crosswalk detection and tracking system to prove the effectiveness of the proposed strategy.

• 로봇학회논문지
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• 제2권2호
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• pp.129-136
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• 2007

This paper introduces a position-based robust visual servoing method which is developed for operation of a human-like robot with two arms. The proposed visual servoing method utilizes SIFT algorithm for object detection and CAMSHIFT algorithm for object tracking. While the conventional CAMSHIFT has been used mainly for object tracking in a 2D image plane, we extend its usage for object tracking in 3D space, by combining the results of CAMSHIFT for two image plane of a stereo camera. This approach shows a robust and dependable result. Once the robot's task is defined based on the extracted 3D information, the robot is commanded to carry out the task. We conduct several position-based visual servoing tasks and compare performances under different conditions. The results show that the proposed visual tracking algorithm is simple but very effective for position-based visual servoing.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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• pp.1245-1248
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• 1996

This paper describes a cell programming environment that deals with problems associated with programming Flexible Manufacturing Cells(FMCs). The environment consists of the cell programming editor and the automatic generation module. In the cell programming editor, cell programmers can develop cell programs using task level description set which supports task-oriented specifications for manipulation cell activities. This approach to cell programming reduces the amount of details that cell programmers need to consider and allows them to concentrate on the most important aspects of the task at hand. The automatic generation module is used to transform task specifications into executable programs used by cell constituents. This module is based on efficient algorithm and expert systems which can be used for optimal path planning of robot operations and optimal machining parameters of machine tool operations. The development tool in designing the environment is an object-oriented approach which provides a simple to use and intuitive user interface, and allows for an easy development of object models associated with the environment.

• 로봇학회논문지
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• 제14권2호
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• pp.104-113
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• 2019

Object manipulation in cluttered environments remains an open hard problem. In cluttered environments, grasping objects often fails for various reasons. This paper proposes a novel task and motion planning scheme to grasp objects obstructed by other objects in cluttered environments. Task and motion planning (TAMP) aims to generate a sequence of task-level actions where its feasibility is verified in the motion space. The proposed scheme contains an open-loop consisting of three distinct phases: 1) Generation of a task-level skeleton plan with pose references, 2) Instantiation of pose references by motion-level search, and 3) Re-planning task based on the updated state description. By conducting experiments with simulated robots, we show the high efficiency of our scheme.

• 한국전자거래학회지
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• 제4권1호
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• pp.145-157
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• 1999

The challenge is to maximize the time-to-market benefits of concurrent engineering while maintaining control of data and distributing it automatically to the people who need it when they need it. The way PDM systems cope with this challenge is that master data is held only once in a secure vault where its integrity can be assured and all changes to it monitored, controlled and recorded. The structure of PDM is various from vendor, but they have common module. That is PDM and it is most important. The goal is to design the workflow in PDM using object-oriented modeling method. The past methods have concentrated on the flow between workflow engine and agent, but this paper will focus on task. We will model task as individual object. This paper uses OMT(Object Modeling Technique) by James Rumbaugh for base modeling tool and uses DCOM(Distributed Component Object Model) for base ORB(Object Request Broker). Research object is to design the static object model, to design state change by dynamic model and to design data transition by functional model.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.2713-2718
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• 2003

Some of manufacturing tasks such as sawing task often requires continuous impulsive motion. In case of sawing task, such impulsive motions can be observed between the teeth of the saw and the object. The amount of the external impulse exerted on the object has been treated as an important control parameter. The purpose of this work is to introduce a new concept of an effective mass in sawing task and to suggest an external impulse model in sawing task. A normalized impulse ellipsoid reflecting the velocity direction is employed to visualize the impact geometry. Experiments are performed for soft and hard workpieces to justify the external impulse model in the sawing task. It is demonstrated through simulation and experiment that the proposed external impulse model is effective to characterize the impact property.

• 한국과학교육학회지
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• 제14권2호
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• pp.133-142
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• 1994

Many students have misconceptions that upward direction force act on the object which is moving upward after being thrown vertically upward, and no force act on the object at the top of its flight because the object stop or don't' move at the top. To change these misconceptions, in this study, deductive reasoning tasks were used, and student's responses to the tasks were analyzed. In the first part of this study, student's prior conceptions about force and motion and student's deductive reasoning abilities were investigated. And the second part, student's explanations were classified to either the premise-based or idea-based explanation. In the case of the object which is moving upward, 62% of students who had misconception changed their misconceptions to physically correct concept, but, only 24% of students changed their misconceptions for the object at the top. For the first task, more students changed their misconceptions when they made responses based on premises than based on their own idea(p<.05), so, the first task can be helpful for conceptual change. 40% students changed their own misconception by reasoning deductively based on premises provided in the first task, but only 17% students changed by the second task. Student's reasoning abilities investigated in the first part of this study did not affect the conceptual change. Four students for the first task and one student for the second task did not change their misconception even though they made premise-based explanation and had high reasoning abilities.