453 research outputs found

    Self-critical Sequence Training for Image Captioning

    Full text link
    Recently it has been shown that policy-gradient methods for reinforcement learning can be utilized to train deep end-to-end systems directly on non-differentiable metrics for the task at hand. In this paper we consider the problem of optimizing image captioning systems using reinforcement learning, and show that by carefully optimizing our systems using the test metrics of the MSCOCO task, significant gains in performance can be realized. Our systems are built using a new optimization approach that we call self-critical sequence training (SCST). SCST is a form of the popular REINFORCE algorithm that, rather than estimating a "baseline" to normalize the rewards and reduce variance, utilizes the output of its own test-time inference algorithm to normalize the rewards it experiences. Using this approach, estimating the reward signal (as actor-critic methods must do) and estimating normalization (as REINFORCE algorithms typically do) is avoided, while at the same time harmonizing the model with respect to its test-time inference procedure. Empirically we find that directly optimizing the CIDEr metric with SCST and greedy decoding at test-time is highly effective. Our results on the MSCOCO evaluation sever establish a new state-of-the-art on the task, improving the best result in terms of CIDEr from 104.9 to 114.7.Comment: CVPR 2017 + additional analysis + fixed baseline results, 16 page

    Angle of Attack Modulation for Mars Entry Terminal State Optimization

    Get PDF
    From the perspective of atmospheric entry, descent, and landing (EDL), one of the most foreboding destinations in the solar system is Mars due in part to its exceedingly thin atmosphere. To benchmark best possible scenarios for evaluation of potential Mars EDL system designs, a study is conducted to optimize the entry-to-terminal-state portion of EDL for a variety of entry velocities and vehicle masses, focusing on the identification of potential benefits of enabling angle of attack modulation. The terminal state is envisioned as one appropriate for the initiation of terminal descent via parachute or other means. A particle swarm optimizer varies entry flight path angle, ten bank profile points, and ten angle of attack profile points to find maximum-final-altitude trajectories for a 10 30 m ellipsled at 180 different combinations of values for entry mass, entry velocity, terminal Mach number, and minimum allowable altitude. Parametric plots of maximum achievable altitude are shown, as are examples of optimized trajectories. It is shown that appreciable terminal state altitude gains (2.5-4.0 km) over pure bank angle control may be possible if angle of attack modulation is enabled for Mars entry vehicles. Gains of this magnitude could prove to be enabling for missions requiring high-altitude landing sites. Conclusions are also drawn regarding trends in the bank and angle of attack profiles that produce the optimal trajectories in this study, and directions for future work are identified

    Mems device with large out-of-plane actuation and low-resistance interconnect and methods of use

    Full text link
    Source: United States Patent and Trademark Office, www.uspto.gov”The present application is directed to a MEMS device. The MEMS device includes a substrate having a first end and a second end extending along a longitudinal axis, the Substrate including an electrostatic actuator. The device also includes a movable plate having a first end and a second end. The device also includes a thermal actuator having a first end coupled to the first end of the substrate and a second end coupled to the first end of the plate. The actuator moves the plate in relation to the substrate. Further, the device includes a power source electrically coupled to the thermal actuator and the Substrate. The application is also directed to a method for operating a MEMS device

    Gallus GBrowse: a unified genomic database for the chicken

    Get PDF
    Gallus GBrowse (http://birdbase.net/cgi-bin/gbrowse/gallus/) provides online access to genomic and other information about the chicken, Gallus gallus. The information provided by this resource includes predicted genes and Gene Ontology (GO) terms, links to Gallus In Situ Hybridization Analysis (GEISHA), Unigene and Reactome, the genomic positions of chicken genetic markers, SNPs and microarray probes, and mappings from turkey, condor and zebra finch DNA and EST sequences to the chicken genome. We also provide a BLAT server (http://birdbase.net/cgi-bin/webBlat) for matching user-provided sequences to the chicken genome. These tools make the Gallus GBrowse server a valuable resource for researchers seeking genomic information regarding the chicken and other avian species

    Pockets of Proterozoic hydrocarbons and implications for the Archaean

    Get PDF
    Precambrian biomarkers convey invaluable information about the early evolution of life, ancient ecosystems, redox conditions, climate and depositional environment and prospective petroleum systems. They are however thermally unstable, easily obliterated by contamination and thus extremely difficult to find. This is particularly true if conditions favourable for biomarker preservation had to prevail for more than 2.5 billion years – the prerequisite for finding Archaean biomarkers. Many organic geochemists abandoned this hope after original discoveries of Archaean biomarkers proved to be of younger origin [1,2] but our study of ca. 550-825 Ma old sediments from the Centralian Superbasin now shows that biomarkers can be preserved in distinctive pockets in seemingly barren areas, even if sections are metamorphosed in parts. Most Centralian sections seem empty. Yet, eventually we identified intervals with preserved biomarkers in three drill cores. A detailed investigation of 825 Ma sediments in drill core Mt Charlotte-1 revealed maturity variations that are most likely due to hydrothermal influence and in turn control the hydrocarbon preservation. Sediments might appear metamorphosed after localized, subtle alteration by hydrothermal fluids but protected intervals can still contain biomarkers. The same might be true for Archaean sediments and we might still find those protected intervals with indigenous biomarkers that allow us to glimpse the early life on earth

    The Conway-Kochen argument and relativistic GRW models

    Get PDF
    In a recent paper, Conway and Kochen proposed what is now known as the "Free Will theorem" which, among other things, should prove the impossibility of combining GRW models with special relativity, i.e., of formulating relativistically invariant models of spontaneous wavefunction collapse. Since their argument basically amounts to a non-locality proof for any theory aiming at reproducing quantum correlations, and since it was clear since very a long time that any relativistic collapse model must be non-local in some way, we discuss why the theorem of Conway and Kochen does not affect the program of formulating relativistic GRW models.Comment: 16 pages, RevTe

    Groundwater: From Windmills to Comprehensive Public Management

    Get PDF
    I. Preface II. Introduction III. The First Period—Territorial Days to 1920 IV. The Second Period—The Impetus for Change Emerges in the \u2720s, \u2730s, and \u2740s … A. Mechanization and Electrification … B. Drought and Depression … C. Profitability of Irrigation … D. Knowledge about Groundwater Sources … E. Adoption of a Legal Rule to Govern Conflicts between Adjoining Owners—Olson v. City of Wahoo … F. Legislative Response and Public Opinion V. The Third Era—1950 to 1972 … A. Rapidity of Growth … B. Overview of Developments in Specific Areas … C. Declining Water Tables … D. Judicial Rules Governing Disputes between Adjacent Landowners … 1. The Reasonable Use Doctrine … 2. The Correlative Rights Doctrine … 3. Conclusion … E. Safeguarding Municipal Supplies … 1. Background … 2. Insecurity under Judge-Made Rules … 3. Omaha\u27s Leadership in Obtaining Enactment of the City, Village, and Municipal Corporation Ground Water Permit Act … a. Flaws in the Act … b. Litigation under the Act—MUD v. Merrit Beach Co. … F. Water for Industry … 1. Burger v. City of Beatrice … 2. The Stumbling Block of the Nebraska Preference Statute … 3. Proposals to Aid in Future Municipal Planning … 4. Conclusion … G. The Movement toward Management of Groundwater in Nebraska … 1. Non-Using Owners … 2. Overdevelopment … 3. Future Generations … 4. A Water Market … 5. The Public Interest … 6. Integration of Streams and Groundwater Supplies … a. Cut-Off Lines … b. The Restatement Position … H. Local Control … 1. Special Purpose Districts in Nebraska … 2. Summary of LB1357 … 3. Management Powers for Natural Resources Districts—An Appropriation, Permit System for Nebraska … a. Introduction … b. Permits … (1) Vested Rights … (2) Procedure for Issuance of Permits … (3) Subirrigation … (4) Standard Conditions … (5) Prescriptive Rights … c. General Powers … (1) Collection of Data … (2) Rules and Regulations … (3) Pollution … (4) Rotation and Exchange Agreements … (5) Practical Adjustments … (6) Substitute Supply from District … (7) Sales and Exchanges … (8) Taxes and Extraction Charges … (9) Eminent Domain … (10) Minimum Stream Flows … (11) Perched Water Tables … d. Critical Areas … e. Special Powers in Critical Areas … f. Litigation … g. Lobbying and Public Relations … h. Conjunctive Use VI. Conclusion VII. Appendi

    Dilute gas of ultracold two-level atoms inside a cavity; generalized Dicke model

    Full text link
    We consider a gas of ultracold two-level atoms confined in a cavity, taking into account for atomic center-of-mass motion and cavity mode variations. We use the generalized Dicke model, and analyze separately the cases of a Gaussian, and a standing wave mode shape. Owing to the interplay between external motional energies of the atoms and internal atomic and field energies, the phase-diagrams exhibit novel features not encountered in the standard Dicke model, such as the existence of first and second order phase transitions between normal and superradiant phases. Due to the quantum description of atomic motion, internal and external atomic degrees of freedom are highly correlated leading to modified normal and superradiant phases.Comment: 10 pages, 7 figure

    Analytical performance of an immunoprofiling assay based on RNA models

    Get PDF
    As immuno-oncology drugs grow more popular in the treatment of cancer, better methods are needed to quantify the tumor immune cell component to determine which patients are most likely to benefit from treatment. Methods such as flow cytometry can accurately assess the composition of infiltrating immune cells; however, they show limited use in formalin-fixed, paraffin-embedded (FFPE) specimens. This article describes a novel hybrid-capture RNA sequencing assay, ImmunoPrism, that estimates the relative percentage abundance of eight immune cell types in FFPE solid tumors. Immune health expression models were generated using machine learning methods and used to uniquely identify each immune cell type using the most discriminatively expressed genes. The analytical performance of the assay was assessed using 101 libraries from 40 FFPE and 32 fresh-frozen samples. With defined samples, ImmunoPrism had a precision of ±2.72%, a total error of 2.75%, and a strong correlation (
    • …
    corecore