Developing a Compensation System: The Experience of the Downers Grove Public Library

published or submitted for publicatio

Bowen Measure From Heteroclinic Points

We present a new construction of the entropy-maximizing, invariant probability measure on a Smale space (the Bowen measure). Our construction is based on points that are unstably equivalent to one given point, and stably equivalent to another: heteroclinic points. The spirit of the construction is similar to Bowen's construction from periodic points, though the techniques are very different. We also prove results about the growth rate of certain sets of heteroclinic points, and about the stable and unstable components of the Bowen measure. The approach we take is to prove results through direct computation for the case of a Shift of Finite type, and then use resolving factor maps to extend the results to more general Smale spaces

Analyticity of the SRB measure for a class of simple Anosov flows

We consider perturbations of the Hamiltonian flow associated with the geodesic flow on a surface of constant negative curvature. We prove that, under a small perturbation, not necessarely of Hamiltonian character, the SRB measure associated to the flow exists and is analytic in the strength of the perturbation. An explicit example of "thermostatted" dissipative dynamics is constructed.Comment: 23 pages, corrected typo

Aerodynamic characteristics determined during development of the Apollo launch escape vehicle configuration

Aerodynamic characteristics determined during development of Apollo launch escape vehicle configuration in wind tunnel test

Ultimate ocean depth packaging for a digital ring laser gyroscope

A Honeywell GG 1320AN Digital Ring Laser Gyroscope (RLG), typically an aviation sensor, has been adapted for use as part of a navigation package rated to ocean depths of 6,000 meters. Researchers and engineers at the Deep Submergence Laboratory (DSL) of the Woods Hole Oceanographic Institution (WHOI) designed a high-density instrument package around the basic RLG. The integrated instrument is modular and field serviceable. It includes a chassis, housing, a Crossbow 6-axis dynamic measurement unit (DMU), battery backup, power regulation, support circuitry and robust interfaces. A pressure-proof titanium case and non-corroding accessories ensure that the RLG will remain unaffected by prolonged immersion in seawater. Associated mounting bracketry allow the housing to be axially registered alongside the navigation suites of various deep diving WHOI assets, or with any host platform capable of caring a 25 pound payload. Primary RLG platforms will be the manned deep submergence vehicle ALVIN, the unmanned remotely operated vehicle JASON, and the unmanned autonomous vehicle ABE. As an extremely accurate yaw rate measuring device, the RLG will provide navigation data far more reliable and precise that has been available to scientists in the past. The WHOI RLG has been used successfully on one JASON cruise.Funding was provided by the National Science Foundation under Grant No. OCE-9710512

Mosaic: A Lifetime of Poems

In hopes of providing a clearer picture of the aging process and its effects on our personalities, follow this collection of poems through diary-like entries of individuals navigating their lives from daycare, heartbreak, and loneliness. The impact that development can have on our psychological well-being and brains is fascinating and feels familiar. Why do we see the world so differently when we are young? As we grow older, what is so important that makes us shift how we view ourselves and our environment multiple times? It is often seen that each generation shares like-mindedness throughout their lives – why

A passive capture latch for ODYSSEY-class AUVs

Under subcontract to the Massachusetts Institute of Techology's (MIT) Sea Grant Autonomous Ocean Sampling Network (AOSN) program, the Woods Hole Oceanographic Institution's Deep Submergence Laboratory (WHOI-DSL) produced a passive capture latch for ODYSSEY -class autonomous underwater vehicles (AUVs). The latch is an all-titanium, split tine device, shock-mounted to the bow of the AUV. When the AUV concludes a survey mission and returns to a moored, midwater docking station, the latch leads the AUV's approach and is the first device to collide with the station's vertical docking pole. Latching to the pole is an entirely passive event requiring only forward motion of the AUV. A positive capture indication generated by proximity switches mounted on the device initiates AUV power and data transfer servicing by the station. Unlatching action requires one revolution of a latch motor cam and a brief backing command to the AUV thruster. The possibility of system malfunction was considered in latch design. If for any reason the latched vehicle canot perform normal unlatching behavior, or the station fails, the latch defaults by securing the AUV to the moored station indefinitely. Two WHOI AUV latches have been used successfully on three offshore engineering test cruises.Funding was provided by the Offce of Naval Research under Grant No. NOOO-14-95-1-1316

Changes in the Forest Composition in the Great Lakes St. Lawrence Forest Region of Ontario and the Resultant Outbreaks of the Spruce Budworm \u3cem\u3eChoristoneura fumiferana\u3c/em\u3e (CLEM.)

The spruce budworm Choristoneura fumiferana Clem. is the foremost forest pest in Canada. The species is endemic to eastern North America. Since the turn of the century the insect has become a major problem in the “Great Lakes St. Lawrence Forest Region” of Ontario, an area where prior to recent times the insect did not occur in damaging numbers. Analysis of the life cycle of the insect reveals that the only limiting factor capable of controlling outbreaks is a lack of food. The required tree species is balsam fir Abies balsama (L.) Mill. The forests of Ontario have been altered to favour the balsam fir. Logging of the former pine forests that once dominated the landscape and the fires which followed are responsible for such change. It has also been shown that changes in the climate may also be responsible for the increase in balsam fir as a dominant species of the forests of Ontario. Once established balsam fir forests and the spruce budworm are a self-regulating natural system, an evolved process that ensures a future food supply for the insect. The suppression of forest fires since the logging era is also shown to encourage the continual presence of high balsam fir content forests. The budworm will continue to thrive and cause damage in that region where it did not formerly occur in significant numbers

Teleportation of continuous variable polarisation states

This paper discusses methods for the optical teleportation of continuous variable polarisation states. We show that using two pairs of entangled beams, generated using four squeezed beams, perfect teleportation of optical polarisation states can be performed. Restricting ourselves to 3 squeezed beams, we demonstrate that polarisation state teleportation can still exceed the classical limit. The 3-squeezer schemes involve either the use of quantum non-demolition measurement or biased entanglement generated from a single squeezed beam. We analyse the efficacies of these schemes in terms of fidelity, signal transfer coefficients and quantum correlations