• Journal of Institute of Control, Robotics and Systems
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• v.6 no.2
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• pp.190-196
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• 2000

A hybrid position/force control scheme to regulate the force and position by dual arms is proposed where two arms are treated as one rm in a kinematic viewpoint. The force error calculated from the information of two force/torque sensors attached to the end of each arm is transferred to minimum configuration space coordinates and then is distributed to total system joint coordinates, The position adjustment at the total con-figuration coordinates is computed based on the effective compliance matrix with respect to total joint coordinates which is obtained by coordinate transformation between the task coordinates and the total joint coordinates. The proposed scheme is applied to sawing task. When the trajectory of the saw is planned to follow a line in a horizontal plane 2 position parameters are to be controlled(i.e., two translational positions) Also a certain level of contact force has to be controlled along the vertical direction(i.e. minus z-direction) not to loose the contact with the object to be sawn. We experimentally show that the performance of the velocity and force response are satisfactory. The proposed hybrid control scheme can be applied to arbitrary two cooperating arm system regardless of their kinematic structure and the number of actuated joints.

• Wind and Structures
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• v.30 no.1
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• pp.15-27
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• 2020

This paper reports the study on development and verification of numerical models and analyzes of flow at high speed around structural elements in the shape of a curved pipe (e.g., a fragment of a water slide). Possibility of engineering estimation of wind forces acting on an object in the shape of a helix is presented, using relationships concerning toroidal and cylindrical elements. Determination of useful engineering parameters (such as aerodynamic forces, pressure distribution, and air velocity field) is presented, impossible to obtain from the existing standard EN 1991-1-4 (the so-called wind standard). For this purpose, flow at high speed around a torus and helix, arranged both near planar surface and high above it, was analyzed. Analyzes begin with the flow around a cylinder. This is the simplest object with a circular cross-section and at the same time the most studied in the literature. Based on this model, more complex models are analyzed: first in the shape of half of a torus, next in the shape of a helix.

• The Transactions of the Korea Information Processing Society
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• v.4 no.12
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• pp.3097-3110
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• 1997

As to the recent advances in computer technologies and high-speed networks, telecommunication services and provision of multimedia services will be provided on the basic of a new software architecture adapting networking infrastructure on open information networking architecture. In this paper, the video conference services has been selected as a target service example because it is expected to become one of the most important services on the full service network. In fact, it can be viewed as the basis for providing telecommunication services such as video telephony and video conferencing. This paper presents the prototyping of TINA (Telecommunication Information Networking Architecture) based desktop video conference system using the concepts of session management. The prototyping of desktop video conference system aims at assessing TINA concepts and refinement of the mapping between session graph and connection graph, and provides object modeling methodologies towards distribution and objected-orientation.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.610-615
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• 2005

Visual servoing is the fusion of results from many elemental areas including high-speed image processing, kinematics, dynamics, control theory, and real-time computing. It has much in common with research into active vision and structure from motion, but is quite different from the often described use of vision in hierarchical task-level robot control systems. We present a new approach to visual feedback control using image-based visual servoing with the stereo vision in this paper. In order to control the position and orientation of a robot with respect to an object, a new technique is proposed using a binocular stereo vision. The stereo vision enables us to calculate an exact image Jacobian not only at around a desired location but also at the other locations. The suggested technique can guide a robot manipulator to the desired location without giving such priori knowledge as the relative distance to the desired location or the model of an object even if the initial positioning error is large. This paper describes a model of stereo vision and how to generate feedback commands. The performance of the proposed visual servoing system is illustrated by the simulation and experimental results and compared with the case of conventional method for dual-arm robot made in Samsung Electronics Co., Ltd.

• The KIPS Transactions:PartA
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• v.10A no.5
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• pp.493-502
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• 2003

For increasing needs about web-based XML applications, there has been a lot of studies about WIDL, CDF and OSD that are related to XML. Especially, the OSD format describes software packages and their inter-dependencies that is widely used in a CDF file, IT uses different forms for representing relationships among software pakages, because there has not been proposed a method of object modeling about it until now. In this paper, we propose a modeling method for the OSD and CDF documents using UML relationships. It is a part of the project to merge XML, applications and convert thd OCD and CDF documents into an IML class diagram to generate OODB sheme. We can esily not only visualuze implementation and dependency relationships among software packages but also understand and transform logical structure of XML documents using modeling functions.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.19 no.3
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• pp.462-478
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• 1994

Conventional hypermedia systems provide a simple data model based on nodes and link, and give us the limited capability in information retrieval such as browsing and navigating following the links. In this paper, we design and implement a hypermedia system (AHEAD) with enhanced data modeling and querying capability, which are strongly supported in object-oriented database technology. The AHEAD makes it possible to model the accurate data semantics and relationships in application domain, to represent useful information related to nodes and links, and to define the structure and manipulation operations of multimedia data. It also support the various querying capabilities by using modeling information.

• Journal of Institute of Control, Robotics and Systems
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• v.10 no.4
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• pp.350-356
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• 2004

This paper presents a farce manipulability analysis of multi-legged walking robots, which calculates force or acceleration workspace attainable from joint torque limits of each leg. Based on the observation that the kinematic structure of the multi-legged walking robots is basically the same as that of multiple cooperating robots, we derive the proposed method of analyzing the force manipulability of walking robot. The force acting on the object in multiple cooperating robot systems is taken as reaction force from ground to each robot foot in multi-legged walking robots, which is converted to the force of the body of walking robot by the nature of the reaction force. Note that each joint torque in multiple cooperating robot systems is transformed to the workspace of force or acceleration of the object manipulated by the robots in task space through the Jacobian matrix and grasp matrix. Assuming the torque limits are given in infinite norm-sense, the resultant dynamic manipulability is derived as a polytope. The validity of proposed method is verified by several examples, and the proposed method is believed to be useful for the optimal posture planning and gait planning of walking robots.

• The Journal of the Korea Contents Association
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• v.5 no.5
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• pp.78-84
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• 2005

Various kinds of data broadcasting services can be offered using a return-channel in digital broadcasting TV compared to analog services. In these data broadcasting environments, several data(associated with TV broadcasting programs, or not) are provided to the TV audiences except for audio/video broadcasting data. In this paper, a structure of data manager for data/object carousel, based on data broadcasting protocols, was proposed for data broadcasting services using a return-channel, and were supported to the production technologies of DTV contents. These contents application techniques for DTV will be implemented with this data manager in MPEG2-TS data broadcasts using PID(Packet ID).

• Asia pacific journal of information systems
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• v.11 no.2
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• pp.121-139
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• 2001

VOQL* query language, recently proposed, is a visual language for object-oriented databases. It is based on Ven Diagram and graph, so that the underlying schema structure can be naturally implied in query expressions. In VOQL*, structural relationship among the objects used in a query expression is represented graphically and thus it has formal semantics that can be inductively defined, as well as it can be used with ease. In this paper, we proposed revised VOQL* and introduced its query processor, InQs(Intelligent Querying System). While retaining the merit of VOQL* that it allows the structural relationship among the objects to be represented visually, the revised VOQL* has another merit that users can formulate a query interactively using various forms supplied by InQs. As a query processor that translates queries in revised VOQL into those in ODMG OQL, InQs provides an environment in which users express queries in revised VOQL* and then the system automatically translates them into those in ODMG OQL. Translation algorithm of InQs is much simpler and intuitive than other algorithms used in QUIVER and other systems, since it reflects the formal semantics of VOQL*, which is defined inductively.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.15 no.2
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• pp.263-268
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• 1997

Software structure must be dynamic to support new geospatial information sources and their object-oriented implementation on the Web. JAVA is interactive, platform idependent and object-oriented language and meets all needs on Internet GSIS. This paper introduce JAVA based GIS program to manipulates various geographic data on Internet, communicating interactively and transfer real-time data between server and client. This and this program analysis roof detector in all part of Pusan area and indicates the traffic states, road surface conditions, weather information, shortest cut, and road names in JAVA client windows. Also this study shows various techniques in expression real time traffic informations.