• Title/Summary/Keyword: Non-rigid System

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The Cognition of Non-Ridged Objects Using Linguistic Cognitive System for Human-Robot Interaction (인간로봇 상호작용을 위한 언어적 인지시스템 기반의 비강체 인지)

  • Ahn, Hyun-Sik
    • Journal of Institute of Control, Robotics and Systems
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    • v.15 no.11
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    • pp.1115-1121
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    • 2009
  • For HRI (Human-Robot Interaction) in daily life, robots need to recognize non-rigid objects such as clothes and blankets. However, the recognition of non-rigid objects is challenging because of the variation of the shapes according to the places and laying manners. In this paper, the cognition of non-rigid object based on a cognitive system is presented. The characteristics of non-rigid objects are analysed in the view of HRI and referred to design a framework for the cognition of them. We adopt a linguistic cognitive system for describing all of the events happened to robots. When an event related to the non-rigid objects is occurred, the cognitive system describes the event into a sentential form and stores it at a sentential memory, and depicts the objects with a spatial model for being used as references. The cognitive system parses each sentence syntactically and semantically, in which the nouns meaning objects are connected to their models. For answering the questions of humans, sentences are retrieved by searching temporal information in the sentential memory and by spatial reasoning in a schematic imagery. Experiments show the feasibility of the cognitive system for cognizing non-rigid objects in HRI.

The Type and Development for Structure System with Non-rigid Member (대공간 연성 구조시스템의 종류와 발달과정)

  • Lee, Ju-Na;Park, Sun-Woo;Park, Chan-Soo
    • 한국공간정보시스템학회:학술대회논문집
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    • 2004.05a
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    • pp.148-157
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    • 2004
  • The structure systems with non-rigid member were classified by the composition type of line and surface members. As a result of the classification, there are 1-way cable structure, cable net and radial cable net structure in the line member system. And there are pneumatic structure and suspension membrane structure in surface member system. In addition, when the line and surface members are composed together, there is the hybrid membrane system which are divided into hanging type and supported type. In this paper, the Korean terms of structure systems with non-rigid member are recommended through this classification. In each the structure systems with non-rigid member, the examples were also investigated considering their historical developments. It present that the light weight structure system and the openness of space have pursued with the developments. So largely, cable net structure with membrane, membrane structure and hybrid structure have used in these days.

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Suggestions of Define Methods by Rigid/Non-Rigid Parts' Definitions (강체와 비강체 부품의 정의와 지정방법에 대한 제안)

  • Kim, Jae-Moon;Chang, Sung-Ho;Lee, Wang-Bum
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.41 no.3
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    • pp.115-119
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    • 2018
  • Defining and measuring non-rigid or flexible parts has been controversial in industry for many years. There are two primary areas of controversy. The first is agreeing on what exactly a non-rigid part is. The second is agreeing on how to define and measure a non-rigid part. The subject of non-rigid parts is further complicated by the brief coverage it receives in the national and international standards. This leaves each company to improvise or create its own rules for non-rigid parts. There are some who believe that Geometrical Dimensioning and Tolerancing (GD&T) should not be used on non-rigid parts. This is not true. The ASME Y14.5M standard applies to rigid parts as a default condition. However, there is no definition given for a rigid part. The term rigid part has been used in industry for so long that it has gained a definition by its general use. When most people in industry say rigid part, they are referring to a part doesn't move (deform or flex) when a force (including gravity) is applied. How much force is relative based on the part characteristics. In reality, all parts will deform (or flex) if enough force is applied. Using this logic, all parts would be considered non-rigid. However, we all know that this is not how parts are treated in industry. Although GD&T defaults to rigid parts, it should also be used on non-rigid parts with a few special techniques. Actually 50~60% of all products designed contain parts or features on parts that are non-rigid. Therefore, we try to suggest the definitions of rigid and non-rigid parts and method to measure non-rigid parts.

Molecular Dynamics Simulation Studies of Zeolite A. VIII. Structure and Dynamics of Na+ ions in a Non-Rigid Dehydrated Zeolite-A Framework

  • 이송희;최상구
    • Bulletin of the Korean Chemical Society
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    • v.20 no.5
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    • pp.587-591
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    • 1999
  • A molecular dynamics simulation study on the structure and dynamics of Na+ ions in non-rigid dehydrated Na12-A zeolite framework at 298.15 K was conducted using the same method reported in previous studies on rigid and non-rigid Na12-A zeolite frameworks. The agreement between the experimental and calculated results for the zeolite-A framework atoms of structural parameters for non-rigid dehydrated Na12-A zeolite is generally quite good, and for the adsorbed Na+ions the agreement is acceptable. The calculated bond lengths are generally in good agreement with the experimental results and other theoretical data. The calculated IR spectrum by Fourier transform of the total dipole moment autocorrelation function shows two major peaks around 2700 cm-1 and 7000 cm-1. The former appeared in the calculated IR spectra of non-rigid zeolite-A framework only system and the latter remains unexplained except, perhaps, indicating a new formation of a vibrational mode of the framework due to the adsorption of Na+ ions. The peaks above 6200-6800 cm-1 in non-rigid dehydrated Nal2-A zeolite are much larger than those in non-rigid dehydrated H12-A zeolite.

The Term and Classification of Structure System with Non-rigid Member (연성구조시스템의 분류체계와 용어)

  • Lee, Ju-Na;Park, Sun-Woo;Kim, Seung-Deog;Park, Chan-Soo
    • Journal of Korean Association for Spatial Structures
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    • v.4 no.2 s.12
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    • pp.99-105
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    • 2004
  • The structure systems with non-rigid member were classified by the composition type of line and surface members. As a result of the classification, there are 1-way cable structure, cable net and radial cable net structure in the line member system. And there are pneumatic structure and suspension membrane structure in surface member system. In addition, when the line and surface members are composed together, there is the hybrid membrane system which are divided into hanging type and supported type. In this paper, the Korean terms of structure systems with non-rigid member are recommended through this classification.

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GROUP THEORY FOR TETRAAMMINEPLATINUM(II) WITH $C_{2v}\;AN;C_{4v}$ POINT GROUP IN THE NON-RIGID SYSTEM

  • Ashrafi, Ali-Reza;Hamadanian, Masood
    • Journal of applied mathematics & informatics
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    • v.14 no.1_2
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    • pp.289-303
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    • 2004
  • The non-rigid molecule group theory (NRG) in which the dynamical symmetry operations are defined as physical operations is a new field of chemistry. Smeyers in a series of papers applied this notion to determine the character table of restricted NRG of some molecules. In this work, a simple method is described, by means of which it is possible to calculate character tables for the symmetry group of molecules consisting of a number of NH3 groups attached to a rigid framework. We study the full non-rigid group (f-NRG) of tetraammineplatinum(II) with two separate symmetry groups C2v and C4v. We prove that they are groups of order 216 and 5184 with 27 and 45 conjugacy classes, respectively. Also, we will compute the character tables of these groups.

Molecular Dynamics Simulation Studies of Zeolite A. Ⅶ. Structure and Dynamics of $H^+$ ions in a Nom-Rigid Dehydrated H12-A Zeolite Framework

  • 이송희;최상구
    • Bulletin of the Korean Chemical Society
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    • v.20 no.3
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    • pp.285-290
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    • 1999
  • In the present paper, we report a molecular dynamics (MD) simulation study for the structure and dynamics of H+ ions in non-rigid dehydrated H12-A zeolite framework at 298.15 K, using the same method we used in our previous studies of rigid and non-rigid zeolite-A frameworks. It is found that two different structures appear, depending on the choice of the Lennard-Jones parameter (σ) for the H+ ion, as is also observed in the study of rigid dehydrated H12-A zeolite framework, but the ranges of σ are different for the two structures. It is also found that some of the H+ ions exchanged their sites without changing the number of H+ ions at each site. The agreement between experimental and calculated structural parameters for non-rigid dehydrated H12-A zeolite is generally quite good. The calculated IR spectrum by Fourier transform of the total dipole moment auto-correlation function shows two major peaks, one around 2700 cm-1 and the other around 7000 cm-1. The former appears in the calculated IR spectra of non-rigid zeolite-A framework only system and the latter remains unexplained except, perhaps, as an indication of a new formation of a vibrational mode of the framework due to the adsorption of the H+ ions.

The Development and Historical Character for Structure System with Non-rigid Member (연성구조시스템의 발달과정과 역사적 특성)

  • Lee, Ju-Na;Park, Sun-Woo;Park, Chan-Soo
    • Journal of Korean Association for Spatial Structures
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    • v.4 no.3 s.13
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    • pp.93-101
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    • 2004
  • Structural systems have a lot of architectural meaning concerning historical context of structural technology. Therefore, surveying constructed examples and their constructed year, the character and development of various formations of structure systems with non-rigid member were investigated. At the result, the early modem structure systems with non-rigid member were made up from the cable structures, then membrane structures have mainly used after 1970's. The early structural systems had intended to make the large scale space, after 1970's, they have been adopted into the smaller scale space structure, and cable net structure, pneumatic structure and dome typed hybrid membrane system tend to compose the larger scale spare structure.

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A Study on the Closed Linear Movement of the Center of Mass in the Rotatory Movement of a Rigid Body

  • Chung, Byung-Tae
    • Proceedings of the IEEK Conference
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    • 2002.07b
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    • pp.1216-1219
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    • 2002
  • It is understood so far that the center of mass does not make any linear movement from the rotatory movement of a rigid body in the closed system. However, it has been found that the center of mass of the system could make a closed linear movement due to production of an instantaneous center of mass by the Coriolis force in the rotatory movement of a rigid body in the closed system. The nature of the closed linear movement in the non-inertial system and that of the open movement in the inertial system are different from each other. That is, the closed movement is described like the time integration of frictional forces, which is different from the open movement usually considered and described like the time integration of external forces. It is shown in this paper that the Coriolis forces, called a fictitious force in the classical mechanics, is similar to the frictional force so that it causes to move the center of mass of a closed system. In this paper, following an explanation of the closed linear movement of a non-inertial system and the open movement of an inertial system, the source of the closed linear movement phenomenon of a rotatory rigid body is presented.

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A Computer Method for the Dynamic Analysis of a System of Rigid Bodies in Plane Motion

  • Attia, Hazem-Ali
    • Journal of Mechanical Science and Technology
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    • v.18 no.2
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    • pp.193-202
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    • 2004
  • This paper presents a computer method for the dynamic analysis of a system of rigid bodies in plane motion. The formulation rests upon the idea of replacing a rigid body by a dynamically equivalent constrained system of particles. Newton's second law is applied to study the motion of the resulting system of particles without introducing any rotational coordinates. A velocity transformation is used to transform the equations of motion to a reduced set. For an open-chain, this process automatically eliminates all of the non-working constraint forces and leads to an efficient integration of the equations of motion. For a closed-chain, suitable joints should be cut and few cut-joints constraint equations should be included. An example of a closed-chain is used to demonstrate the generality and efficiency of the proposed method.