Physical Sciences and Mathematics Commons^™

The Taman Negara Batek: A People In Transition, Paul Faulstich

Pitzer Faculty Publications and Research

Batek Negritos from the vicinity of Taman Negara National Park in West Malaysia are a hunting and gathering people presently experiencing rapid encroachment by the modern world. Under the authority of the Malaysian government, they are being encouraged to settle and to emulate Malay subsistence farming communities. Unfortunately, this strategy has had a number of adverse effects on the Batek.

Approaching Distributed Database Implementations Through Functional Programming Concepts, Robert M. Keller, Gary Lindstrom

All HMC Faculty Publications and Research

The application of functional programming concepts to the data representation and querying aspects of databases has been discussed by Shipman and Buneman, et al. respectively. We argue the suitability of a function-based approach to additional aspects of database systems, including updating, transaction serialization, and physical distribution and communication. It is shown how the NmergeH extension of a purely functional model permits serializable concurrent "primary site" distribution control. We also present preliminary experimental results which indicate that a reasonable degree of concurrency is attainable from the functional approach.

Measuring R And D Productivity, Richard A. Pappas, Donald S. Remer

All HMC Faculty Publications and Research

Measuring the productivity of an R&D organization is extremely tricky. Productivity is usually defined as a ratio of an output, like number of cars produced on an assembly line, to an input, like the wages paid the workers. While R&D may have a measurable input, the output is often intangible and difficult to quantify. This is further complicated because the return from an R&D department may not be realized for one or two decades,which means the time lag is much higher than in factory measurements. Furthermore, many researchers believe that this kind of measurement may be counterproductive,since the mere act …

Problems Of Channel Correlation And Statistical Bias In Photon-Correlation Spectroscopy, Richard C. Haskell, Gary L. Pisciotta

All HMC Faculty Publications and Research

Correlation between channels of the normalized photocount-rate correlation function g⁽²⁾(τ) becomes significant at high count rates and leads to a number of data-analysis problems. We derive an expression for channel correlation that is valid for a detector area of arbitrary extent and compare the theoretical predictions with measured values. A data-analysis procedure is demonstrated that employs the theoretical expression for channel correlation and provides a rigorous test of an assumed fitting function. The procedure facilitates the use of the cumulant method in determining the polydispersity of scatterers. An expression for the statistical bias of g^{(2) …}

The Quaternary Bone Caves And Associated Sites At Wallingford, Jamaica, Donald A. Mcfarlane, R. E. Gledhill

WM Keck Science Faculty Papers

A group of caves associated with the sink of the One Eye River in St. Elizabeth Parish, Jamaica, have been the subject of numerous important palaeontological investigations beginning 1919. Unfortunately, considerable confusion has arisen in the literature through inadequate documentation of different sites. The caves of the immediate area are described and located, and their palaeontological significance is summarised in the light of recent taxonomic review and relevant geochronological evidence.

Response Of Lithographic Mask Structures To Repetitively Pulsed X-Rays: Thermal Stress Analysis, A. Ballantyne, H.A. Hyman, Clive L. Dym, R.C. Southworth

All HMC Faculty Publications and Research

This paper examines the effects of thermal loading and time history upon the thermal stresses developed in lithographic mask structures as would be expected under irradiation by intense soft x rays. The objective of this work was to examine the phenomenology of the interaction and to evaluate the limits placed upon mask dosage. The mechanics of mask failure are examined in terms of single pulse and cumulative, or fatigue, effects. A number of prototypical mask structures are investigated, which show that the application of intense pulsed sources to x‐ray lithography does not reduce the potential utility of the techique. However, …

Some Graph-Colouring Theorems With Applications To Generalized Connection Networks, David G. Kirkpatrick, Maria M. Klawe, Nicholas Pippenger

All HMC Faculty Publications and Research

With the aid of a new graph-colouring theorem, we give a simple explicit construction for generalized n-connectors with 2k - 1 stages and O( n^{1 + 1 / k} (log n )^{( k - 1)/ 2} ) edges. This is asymptotically the best explicit construction known for generalized connectors.

On The Steepest Descent For Nonpotential Locally Lipschitzian Vector Fields, Alfonso Castro

All HMC Faculty Publications and Research

In [4] J. Neuberger gave various sufficient conditions for the solvability of nonvariational operator equations via a variant of the steepest descent method. In this note we give versions of these conditions under weaker assumptions on the smoothness of the operators.

Response Of Lithographic Mask Structures To Repetitively Pulsed X-Rays: Dynamic Response, Clive L. Dym, A. Ballantyne

All HMC Faculty Publications and Research

This paper addresses the issue of the dynamic response of thin lithographic mask structures to thermally induced stress fields. In particular, the impact of repetitively pulsed x‐ray sources are examined: the short duration (1–100 nsec) pulses induce large step changes in mask temperatures, which can, in turn, induce a dynamic response. The impact of conductive cooling of the mask is to reduce the repetitively pulsed problem to a series of isolated nearly identical thermal impulses of duration approximately equal to the cooling time. The importance of self‐weight and prestress is examined, and an analysis of the nonlinear dynamic response to …

Necessary And Sufficient Conditions For Certain Homology 3-Spheres To Have Smooth Zp-Actions, Erica Flapan

Pomona Faculty Publications and Research

We derive necessary and sufficient conditions for a broad class of homology 3-spheres, obtained as the gluing of two knot complements, to have Zp-actions.

We explore when a homology sphere, obtained as the gluing of two knot complements has any smooth periodic diffeomorphisms.

Infinitely Periodic Knots, Erica Flapan

Pomona Faculty Publications and Research

One aspect of the study of 3-manifolds is to determine what infinite group actions a given manifold has. Some important questions that one can ask about these actions on a given manifold are: What periods could they have? and, what sets of points may be fixed by the action?