The formation of very wide binaries during the star cluster dissolution phase (2010)
Kouwenhoven, M. B. N., Goodwin, S. P., Parker, Richard J., Davies, M. B., Malmberg, D., Kroupa, P.
Over the past few decades, numerous wide (>1000 au) binaries in the Galactic field and halo have been discovered. Their existence cannot be explained by the process of star formation or by dynamical...
The origin of very wide binary systems (2009)
Kouwenhoven, M. B. N., Goodwin, S. P., Parker, Richard J., Davies, M. B., Malmberg, D., Kroupa, P.
The majority of stars in the Galactic field and halo are part of binary or multiple systems. A significant fraction of these systems have orbital separations in excess of thousands of astronomical...
The formation of very wide binaries (2009)
Kouwenhoven, M. B. N., Goodwin, S. P., Parker, Richard J., Davies, M. B., Malmberg, D., Kroupa, P.
Over the last decades, numerous wide (>1000 AU) binaries have been discovered in the Galactic field and halo. The origin of these wide binaries cannot be explained by star formation or by dynamical...
Do binaries in clusters form in the same way as in the field? (2009)
Parker, Richard J., Goodwin, Simon P., Kroupa, Pavel, Kouwenhoven, M. B. N.
We examine the dynamical destruction of binary systems in star clusters of different densities. We find that at high densities (10^4 - 10^5 Msun pc^-3) almost all binaries with separations > 10^3 AU...
The role of cluster evolution in disrupting planetary systems and disks: the Kozai mechanism (2009)
Parker, Richard J., Goodwin, Simon P.
We examine the effects of dynamical evolution in clusters on planetary systems or protoplanetary disks orbiting the components of binary stars. In particular, we look for evidence that the companions...
Using the minimum spanning tree to trace mass segregation (2009)
Allison, Richard J., Goodwin, Simon P., Parker, Richard J., Zwart, Simon F. Portegies, De Grijs, Richard, Kouwenhoven, M. B. N.
We present a new method to detect and quantify mass segregation in star clusters. It compares the minimum spanning tree (MST) of massive stars with that of random stars. If mass segregation is...
Activity Identification and Visualization 1 (2008)
Richard J. Parker, William A. Hoff, Alan Norton, Jae Young Lee, Michael Colagrosso
Abstract. Understanding activity from observing the motion of agents is simple for people to do, yet the procedure is difficult to codify. It is impossible to enumerate all possible motion patterns...
Do O-stars form in isolation? (2007)
Parker, Richard J., Goodwin, Simon P.
Around 4% of O-stars are observed in apparent isolation, with no associated cluster, and no indication of having been ejected from a nearby cluster. We define an isolated O-star as a star > 17.5...
Machine learning applied to human motion and behavior analysis / (2004)
Typescript (photocopy).
Rolling-Element Fatigue Life of AISI M-50 and 18-4-1 Balls. (1998)
Parker, Richard J., Zaretsky, Erwin V.
Rolling-element fatigue studies were conducted with VIM-VAR AISI M-50, EFR 18-4-1, and VAR 18-4-1. Groups of 12.7-mm (1/2-in.) diameter balls of each material were tested in the five-ball fatigue...
Effect of Component Differential Hardnesses on Rolling-Contact Fatigue and Load Capacity (1998)
Zaretsky, Erwin V., Parker, Richard J., Anderson, WIlliam J.
The five-ball fatigue tester was used to study the effect of component hardness combinations on the fatigue life of rolling elements subjected to repeated stresses applied in rolling contact....
Effect of Component Differential Hardness on Residual Stress and Rolling-Contact Fatigue (1998)
Zaretsky, Erwin V., Parker, Richard J., Anderson, WIlliam J., Miller, Steven T.
Residual stress measurements were made in the zone of resolved shearing stress on five SAE 52100 upper test ball specimens with an average Rockwell C hardness of 63.2. These upper test ball specimens...
Parker, Richard J., Grisaffe, Salvatore J., Zaretsky, Erwin V.
The five-ball fatigue tester was used to study the behavior of alumina balls under repeated stresses applied in rolling contact. Hot-pressed and cold-pressed-and-sintered 1/2-inch alumina balls were...
Apparatus for Studying Ball Spinning Friction (1998)
Miller, Steven T., Parker, Richard J., Zaretsky, Erwin V.
An experimental apparatus was designed and constructed at the NASA Lewis Research Center to study one aspect of spinning friction based on interfacial slip over the entire ball-race contact area. The...
Parker, Richard J., Grisaffe, Salvatore J., Zaretsky, Erwin V.
The five-ball fatigue tester was used to study the behavior of nickel- bonded titanium carbide cermet and self-bonded silicon carbide balls under repeated stresses applied in rolling contact. Test...
Bearing Life and Failure Distribution as Affected by Actual Component Differential Hardness (1998)
Zaretsky, Erwin V., Parker, Richard J., Anderson, William J., Reichard, David W.
Rolling-contact fatigue tests were performed on SAE 52100 207-size deep-groove ball bearing determine the relation between bearing fatigue life and actual bearing component hardness differences and...