A Generalized Symbolic Notation for Mechanisms

1971 ◽  
Vol 93 (1) ◽  
pp. 102-112 ◽  
Author(s):  
P. N. Sheth ◽  
J. J. Uicker
Keyword(s):  
Data Collection ◽  
Kinematic Analysis ◽  
Numerical Scheme ◽  
Matrix Methods ◽  
Clear Separation ◽  
Entire Domain ◽  
Rigid Link ◽  
Symbolic Notation

Revisions of the Denavit-Hartenberg symbolic notation are proposed which extend its use to the entire domain of rigid link mechanisms. The extended notation provides a clear separation of the pair variables and the invariant parameters of a mechanism and thus provides a framework in which higher pairs can be systematically modeled. The new symbolism can be used directly with the existing matrix methods of kinematic analysis, and a numerical scheme is presented to reduce the task of data collection for these methods.

scholarly journals Forensic Engineering Determination Of who Was Driving

2011 ◽  
Vol 28 (2) ◽  
Author(s):  
Jeffrey D. Armstrong
Keyword(s):  
Data Collection ◽  
Case Studies ◽  
Kinematic Analysis ◽  
Vehicle Crashes ◽  
Passenger Compartment ◽  
Crash Data ◽  
Physical Evidence ◽  
Forensic Engineering ◽  
Witness Statements

The Investigation Of Vehicle Crashes Occasionally Presents A Question Of Who Was Driving A Vehicle At the Time Of A Collision. Many Accidents Result In Drivers And Passengers Being Thrown About The Passenger compartment, Or Being Completely Ejected From Their Vehicle. In Such Cases, Driver, Passenger, And witness Statements Are Often In Conflict With One Another; Especially When The Driver Could Potentially be Charged With A Crime, Or Be Held Liable For Damages Resulting From A Crash. In Many Cases, Physical evidence Can Provide The Forensic Engineer With Information To Conduct A Proper Reconstruction Of The crash, To Perform An Occupant Kinematic Analysis, And To Make A Determination And Render An Opinion regarding Who Was Driving The Vehicle At The Time Of The Crash.  this Paper Will Address Methodologies For Data Collection And Crash Reconstruction That Can Be Used in Determining Who Was Driving A Vehicle At The Time Of A Crash. It Will Include Instruction To The At-Scene investigator As To Data That Can Be Helpful In Such Analyses And Determinations. Two Case Studies Will Be presented In Which The Author Analyzed The Crash Data To Determine Who Was Driving.

scholarly journals When advertisements are disguised as news: the ethics problem in Indonesian mass media

2021 ◽  
Vol 5 (2) ◽  
pp. 397-420
Author(s):  
Nanang Krisdinanto
Keyword(s):  
Data Collection ◽  
Mass Media ◽  
Research Approach ◽  
Clear Separation ◽  
Qualitative Descriptive ◽  
Journalistic Ethics

The practice of obscuring news and advertising is still a problem in the Indonesian mass media. This research aimed to unravel journalistic ethics problems, especially those related to advertorials (advertisements delivered in an editorial style). The clear separation between news and advertisements is one of the two pillars of journalistic ethics, apart from separating facts and opinions to maintain journalistic independence. The research approach used was qualitative-descriptive, with data collection techniques through interviews (to journalists), observation and document searches. The results showed that most of the printed mass media studied tended to blur the boundaries between news and advertisements through various means, such as removing or shortening advertorial information.  

Kinematic Analysis of Spatial Mechanisms by Means of Constant-Distance Equations

1972 ◽  
Vol 1 (3) ◽  
pp. 129-134 ◽  
Author(s):  
M.O.M. Osman ◽  
D. Segev
Keyword(s):  
Computer Analysis ◽  
Digital Computer ◽  
Kinematic Analysis ◽  
Dimensional Synthesis ◽  
Mobility Analysis ◽  
Rigid Link ◽  
Spatial Mechanisms ◽  
Constant Distance ◽  
Complex Mechanisms

The concept and use of constant-distance equations for the kinematic analysis of linkages are presented. The procedure is based on the fact that a constant-distance equation is formulated, wherever the distance between two pair-centers of a rigid link remains constant throughout its motion. This results in a much simpler kinematic analysis of the linkage. To illustrate the procedure and the feasibility of the method, the cases of spatial RRRR– and RGCR-mechanisms with coupler points are considered. The technique is well suited to digital computer analysis of complex mechanisms; extensions to dimensional synthesis as well as to dynamic and mobility analysis are possible.

Numerical Scheme for the Solution of Fractional Differential Equations of Order Greater Than One

2005 ◽  
Vol 1 (2) ◽  
pp. 178-185 ◽  
Author(s):  
Pankaj Kumar ◽  
Om P. Agrawal
Keyword(s):  
Integral Equation ◽  
Differential Equations ◽  
Fractional Order ◽  
Fractional Differential Equations ◽  
Numerical Scheme ◽  
Numerical Solutions ◽  
Volterra Type ◽  
Entire Domain ◽  
Type Integral ◽  
Fractional Differential

This paper presents a numerical scheme for the solutions of Fractional Differential Equations (FDEs) of order α, 1<α<2 which have been expressed in terms of Caputo Fractional Derivative (FD). In this scheme, the properties of the Caputo derivative are used to reduce an FDE into a Volterra-type integral equation. The entire domain is divided into several small domains, and the distribution of the unknown function over the domain is expressed in terms of the function values and its slopes at the node points. These approximations are then substituted into the Volterra-type integral equation to reduce it to algebraic equations. Since the method enforces the continuity of variables at the node points, it provides a solution that is continuous and with a slope that is also continuous over the entire domain. The method is used to solve two problems, linear and nonlinear, using two different types of polynomials, cubic order and fractional order. Results obtained using both types of polynomials agree well with the analytical results for problem 1 and the numerical results obtained using another scheme for problem 2. However, the fractional order polynomials give more accurate results than the cubic order polynomials do. This suggests that for the numerical solutions of FDEs fractional order polynomials may be more suitable than the integer order polynomials. A series of numerical studies suggests that the algorithm is stable.

Kinematic Analysis of Skill Acquisition in Physically Awkward Boys

1987 ◽  
Vol 4 (4) ◽  
pp. 305-315 ◽  
Author(s):  
Gordon E. Marchiori ◽  
Albert E. Wall ◽  
E. Wendy Bedingfield
Keyword(s):  
Data Collection ◽  
Initial Data ◽  
Skill Acquisition ◽  
Kinematic Analysis ◽  
Performance Data ◽  
Training Period ◽  
Baseline Session ◽  
Control Subjects ◽  
Practice Trials ◽  
Data Collection Session

This study investigated the learning of the stationary hockey slap shot by two physically awkward boys; for comparison purposes, two age-matched boys performed the same skill. In an initial data collection session, the physically awkward and the control boys performed three successful slap shots. Following this, the physically awkward subjects practiced 400 trials at home every 2 weeks over a 6-week training period, under the supervision of their parents. Performance data were collected every 2 weeks, after 400, 800, and 1,200 practice trials. Cinematographic analysis of each subject’s three successful responses led to an examination of the kinematics, phasing, and timing of the slap shot. In the initial baseline session, the control subjects exhibited consistency of performance; however, even after 1,200 trials of supervised practice the performance of the two physically awkward children was extremely variable.

Numerical Scheme for the Solution of Fractional Differential Equations of Order Greater Than 1

2005 ◽  
Author(s):  
Pankaj Kumar ◽  
Om P. Agrawal
Keyword(s):  
Integral Equation ◽  
Differential Equations ◽  
Fractional Order ◽  
Fractional Differential Equations ◽  
Numerical Scheme ◽  
Numerical Solutions ◽  
Volterra Type ◽  
Entire Domain ◽  
Type Integral ◽  
Fractional Differential

This paper presents a numerical scheme for the solutions of Fractional Differential Equations (FDEs) of order α, 1 &lt; α &lt; 2 which have been expressed in terms of Caputo Fractional Derivative (FD). In this scheme, the properties of the Caputo derivative are used to reduce an FDE into a Volterra type integral equation. The entire domain is divided into several small domains, and the distribution of the unknown function over the domain is expressed in terms of the function values and its slopes at the node points. These approximations are then substituted into the Volterra type integral equation to reduce it to algebraic equations. Since the method enforces the continuity of variables at the node points, it provides a solution that is continuous and with a slope that is also continuous over the entire domain. The method is used to solve a simple FDE using two different types of polynomials, namely cubic order and fractional order. Results obtained using both types of polynomials agree well with the analytical results. However, the fractional order polynomials give more accurate results than the cubic order polynomials do. This suggests that for the numerical solutions of FDEs fractional order polynomials may be more suitable than the integer order polynomials. A series of numerical studies suggests that the algorithm is stable.

scholarly journals Marine controlled-source electromagnetic of the Scarborough gas field — Part 3: Multicomponent 2D magnetotelluric/controlled-source electromagnetic inversions

Geophysics ◽  
2019 ◽  
Vol 84 (6) ◽  
pp. B387-B401
Author(s):  
Steven Constable ◽  
Arnold Orange ◽  
David Myer
Keyword(s):  
Data Collection ◽  
Data Sets ◽  
Independent Data ◽  
Gas Field ◽  
Clear Separation ◽  
Controlled Source ◽  
Model Studies ◽  
Lateral Extent ◽  
Thin Reservoir ◽  
Water Depths

We carried out a multicomponent electromagnetic (EM) survey of the Scarborough gas field in 950 m water on the northwest Australian shelf. Magnetotelluric (MT) data, along with transmitter inline horizontal electric (Ey), vertical electric (Ez), and horizontal magnetic (Bx) field controlled-source electromagnetic (CSEM) data were collected. The Scarborough reservoir is a challenging EM target because it lies between a resistive overlying siltstone and a resistive basement. We carried out 2D inversions of various data combinations to determine how well they recover the expected geology. In particular, we examined the value of the vertical electric CSEM fields. Individual inversions of the Ey and Bx components generate almost identical models, suggesting that these two data sets do not carry independent data, although model studies suggest that this may not be the case in shallower water. Both models smear the siltstone, reservoir, and basement resistors together. The Ez-only inversion includes a resistor with a clear lateral extent at reservoir depths that is separated from basement, but when combined with other CSEM components, Ez provides only marginal improvements in resolution. Not surprisingly, an MT-only inversion is blind to the thin reservoir resistor but combined with CSEM data produces a clear separation of the reservoir from the basement. The combination of Ey, MT, and Ez also separates the siltstone horizon from the reservoir. The sensitivity of MT to horizontal conductivity makes it a powerful complement to the standard Ey CSEM data. The Ez CSEM component adds some value, but perhaps not commensurate with the logistical costs of data collection. The horizontal magnetic CSEM field appears to add little value at these water depths, but if simultaneous MT data are being collected, this component will be available at little cost.

scholarly journals KINEMATICS OF POSITIONING DEVICE FOR MATERIAL HANDLING IN MANUFACTURING

2021 ◽  
Vol 8 (1) ◽  
pp. 11-18
Author(s):  
Darina Hroncová ◽  
Ingrid Delyová ◽  
Peter Frankovský
Keyword(s):  
Kinematic Analysis ◽  
Material Handling ◽  
Industrial Robots ◽  
Production Lines ◽  
Matrix Methods ◽  
Automated Production ◽  
Industrial Manipulators ◽  
Different Types ◽  
Positioning Device ◽  
Familiar Environment

Different types of robots are used in many areas of industry. Industrial manipulators are used to ensure productivity and flexibility in automated production lines. Most of them is used for tasks that automatically repeat the same operation in a familiar environment. The key element in the development and analysis of industrial robots is their kinematic analysis. The article deals with the kinematic analysis of this positioning equipment. Individual relations of kinematic quantities are plotted graphically. Matrix methods were used for the analysis.

Jerk Analysis and Axode Geometry of Spatial Linkages

2008 ◽  
Vol 130 (4) ◽  
Author(s):  
H. J. Sommer
Keyword(s):  
Kinematic Analysis ◽  
Closed Loop ◽  
Matrix Methods ◽  
Spatial Linkages

Matrix methods for kinematic analysis of spatial linkages were extended to provide jerk of joint pair variables, individual points, and individual links. Simple expressions for axode geometry were also developed. The methods were tested on revolute-spherical-universal-revolute and revolute-cylindrical-cylindrical-cylindrical closed loop mechanisms.

Electron Diffraction of Wet Biological Membranes

1974 ◽  
Vol 32 ◽  
pp. 158-159
Author(s):  
S.W. Hui ◽  
D.F. Parsons
Keyword(s):  
Electron Diffraction ◽  
Data Collection ◽  
Biological Membranes ◽  
Small Areas ◽  
Electron Diffraction Technique ◽  
Electron Microscopes ◽  
Collection Time ◽  
Camera Length

The development of the hydration stages for electron microscopes has opened up the application of electron diffraction in the study of biological membranes. Membrane specimen can now be observed without the artifacts introduced during drying, fixation and staining. The advantages of the electron diffraction technique, such as the abilities to observe small areas and thin specimens, to image and to screen impurities, to vary the camera length, and to reduce data collection time are fully utilized. Here we report our pioneering work in this area.

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