Recursos de colección

Caltech Authors (167.915 recursos)

Repository of works by Caltech published authors.

Status = Unpublished

Mostrando recursos 1 - 20 de 1.906

  1. PhotoSpec - Comprehensive Ground-Based Studies of Solar-Induced Chlorophyll Fluorescence: From the New Methods for Measurements of Photosynthesis from Space Study

    Frankenberg, Christian; Drewry, Darren; Stutz, Jochen
    The major goal of the PhotoSpec program was to develop a set of robust ground-based spectrometers that meet the measurement requirements to retrieve solar-induced chlorophyll fluorescence by exploiting solar Fraunhofer lines.

  2. Statistical Discrimination and Affirmative Action in the Lab

    Dianat, Ahrash; Echenique, Federico; Yariv, Leeat
    We present results from laboratory experiments studying the impacts of affirmative-action policies. We induce statistical discrimination in simple labor-market interactions between rms and workers. We then introduce affirmative-action policies that vary in the size and duration of a subsidy firms receive for hiring discriminated-against workers. These different affirmative-action policies have nearly the same effect and practically eliminate discriminatory hiring practices. However, once lifted, few positive effects remain and discrimination reverts to its initial levels. One exception is lengthy affirmative-action policies, which exhibit somewhat longer-lived effects. Stickiness of beliefs, which we elicit, helps explain the evolution of these outcomes.

  3. Methane on Mars and Habitability: Challenges and Responses

    Yung, Yuk L.; Chen, Pin; Nealson, Kenneth H.; Atreya, Sushil; Beckett, Patrick; Ehlmann, Bethany; Blank, Jennifer; Eiler, John; Etiope, Giuseppe; Ferry, James G.; Forget, Francois; Gao, Peter; Hu, Renyu; Kleinböhl, Armin; Klusman, Ronald; Lefèvre, Franck; Miller, Charles; Mischna, Michael; Mumma, Michael; Newman, Sally; Oehler, Dorothy; Okumura, Mitchio; Oremland, Ronald; Orphan, Victoria; Popa, Radu; Russell, Michael; Shen, Linhan; Sherwood Lollar, Barbara; Stamenković, Vlada; Staehle, Robert; Stolper, Daniel; Templeton, Alex; Vandaele, Ann C.; Viscardy, Sébastien; Webster, Chris; Wennberg, Paul O.; Wong, Michael; Worden, John
    Recent measurements of methane (CH_4) by the Mars Science Laboratory (MSL) now confront us with robust data that demand interpretation. The baseline level of CH_4 (~1 ppbv, parts per billion by volume) requires a minimum production source of 1.7 × 10^7 mol year^(-1), while the pulses of CH_4 (~10 ppbv) require a source orders of magnitude larger (~5 × 10^9 mol year^(-1) if originating from a point source). What does this CH_4 represent in terms of interior geochemical processes, or is Martian CH_4 a biosignature? Discerning how CH_4 generation occurs on Mars may shed light on the potential habitability of...

  4. Performance of Viscous Damping in Inelastic Seismic Analysis of Moment-Frame Buildings

    Hall, John
    This report investigates the performance of several viscous damping formulations in the inelastic seismic response of moment-frame buildings. The evaluation employs a detailed model of a 20-story steel building. Damping schemes included in the study are Rayleigh, condensed Rayleigh, Wilson-Penzien, two versions of tangent Rayleigh and one implementation of capped damping. Caughey damping is found not to be computationally viable. Differences among the damping schemes, as quantified by amounts of plastic hinge rotations and story drifts, become noticeable once these quantities reach the 3% level. In order of least to greatest hinge rotations and drifts that occur under lateral response...

  5. Observational implications of lowering the LIGO-Virgo alert threshold

    Lynch, Ryan; Coughlin, Michael; Vitale, Salvatore; Stubbs, Christopher W.; Katsavounidis, Erik
    The recent detection of the binary-neutron-star merger associated with GW170817 by both LIGO- Virgo and the network of electromagnetic-spectrum observing facilities around the world has made the multi-messenger detection of gravitational-wave events a reality. These joint detections allow us to probe gravitational-wave sources in greater detail and provide us with the possibility of confidently establishing events that would not have been detected in gravitational-wave data alone. In this paper, we explore the prospects of using the electromagnetic follow-up of low-significance gravitational-wave transient event candidates to increase the sample of confident detections with electromagnetic counterparts. We find that the gravitational-wave alert threshold change that would roughly double the number of detectable astrophysical...

  6. MEMS IMU navigation with model based dead-reckoning and one-way-travel-time acoustic range measurements for autonomous underwater vehicles

    Kepper, James H., IV
    Recent advances in acoustic navigation methodologies are enabling the way for AUVs to extend their submerged mission time and maintain a bounded XY position error. Additionally, advances in inertial sensor technology have drastically lowered the size, power consumption, and cost of these sensors. Nonetheless, these sensors are still noisy and accrue error over time. This thesis builds on the research and recent developments in single beacon one-way travel-time (OWTT) acoustic navigation and investigates the degree of bounding position error for small AUVs with a minimal navigation strap-down sensor suite, relying mostly on a consumer grade microelectromechanical system (MEMS) inertial measurement...

  7. Science-driven Autonomous & Heterogeneous Robotic Networks: A Vision for Future Ocean Observations

    Thompson, Andrew F.; Chien, Steve; Chao, Yi; Kinsey, James
    The goal of this project was to develop the first algorithms that allow a heterogeneous group of oceanic robots to autonomously determine and implement sampling strategies with the help of numerical ocean forecasts and remotely-sensed observations. Two-way feedback with shore-based numerical models, tested in the field, had not previously been attempted. New planning algorithms were tested during two field programs in Monterey Bay during a 12-month period using three different types of autonomous vehicles.

  8. Smog: a report to the people of the South Coast Air Basin. Part I. The EQL Strategy - A Summary (including Figures 1-14). Part II. The EQL Strategy - Legislative and Administrative Action Required

    Lees, Lester; Borrelli, Peter; Easterling, Mahlon; Klein, Burton H.; Pauker, Guy; Poppe, Robert; List, E. John

  9. A Simple Model of Mixing and Chemical Reaction in a Turbulent Shear Layer

    Broadwell, J. E.; Breidenthal, R. E.

  10. Theoretical and Experimental Investigations of Axial Flow Compressors

    Bowen, John T.; Sabersky, Rolf H.; Rannie, W. Duncan; Millikan, Clark B.

  11. Theoretical and Experimental Investigations of Axial Flow Compressors

    Bowen, John T.; Sabersky, Rolf H.; Rannie, W. Duncan; Millikan, Clark B.

  12. Water Tunnel Tests on NACA-66 (Modified) and YS-920 Foil Sections with and whitout Surface Roughness

    Baloga, Paul E.

  13. A Research Program on Solid Propellant Physical Behavior

    Blatz, P. J.; Tschoegl, N. W.; Landel, R. F.

  14. Physicomechanical Behavior of Rubberlike Materials

    Blatz, P. J.

  15. Dynamic Buckling of Structures

    Bhatia, Prem; Babcock, Charles D., Jr.

  16. Fundamental Studies Relating to the Mechanical Behavior to the Mechanical Behavior of Solid Propellants Rocket Grains and Rocket Motors

    Blatz, P. J.; Ko, W. L.; Zak, A.

  17. Fundamental Studies Relating to Sytems Analysis of Solid Propellants

    Blatz, P. J.; Schapery, R. A.; Stimpson, L. D.; Williams, M. L.

  18. Fundamental Studies Relating to Systems Analysis of Solid Propellants

    Blatz, P. J.; Schapery, R. A.; Stimpson, L. D.; Williams, M. L.

  19. A Scaling Technique for the Design of Idealized Electromagnetic Lenses

    Baum, Carl E.

  20. Constant Pressure Laminar Mixing with Arbitrary Initial Velocity and Stagnation Enthalpy Profiles

    Reeves, Barry L.

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