gebhart/patrepeval huggingface dataset:
Differentially Private Algorithms for the Stochastic Saddle Point Problem with Optimal Rates for the Strong Gap (2023)

We show that convex-concave Lipschitz stochastic saddle point problems (also known as stochastic minimax optimization) can be solved under the constraint of $(ε,δ)$-differential privacy with \emph{strong (primal-dual) gap} rate of $\tilde O\big(\frac{1}{\sqrt{n}} + \frac{\sqrt{d}}{nε}\big)$, where $n$ is the dataset size and $d$ is the dimension of the problem. This rate is nearly optimal, based on existing lower bounds in differentially private stochastic optimization. Specifically, we prove a tight upper bound on the strong gap via novel implementation and analysis of the recursive regularization technique repurposed for saddle point problems. We show that this rate can be attained with $O\big(\min\big\{\frac{n^2ε^{1.5}}{\sqrt{d}}, n^{3/2}\big\}\big)$ gradient complexity, and $\tilde{O}(n)$ gradient complexity if the loss function is smooth. As a byproduct of our method, we develop a general algorithm that, given a black-box access to a subroutine satisfying a certain $α$ primal-dual accuracy guarantee with respect to the empirical objective, gives a solution to the stochastic saddle point problem with a strong gap of $\tilde{O}(α+\frac{1}{\sqrt{n}})$. We show that this $α$-accuracy condition is satisfied by standard algorithms for the empirical saddle point problem such as the proximal point method and the stochastic gradient descent ascent algorithm. Further, we show that even for simple problems it is possible for an algorithm to have zero weak gap and suffer from $Ω(1)$ strong gap. We also show that there exists a fundamental tradeoff between stability and accuracy. Specifically, we show that any $Δ$-stable algorithm has empirical gap $Ω\big(\frac{1}{Δn}\big)$, and that this bound is tight. This result also holds also more specifically for empirical risk minimization problems and may be of independent interest.
On the Kinematics of Solar Mirrors Using Massively Parallel Binary Actuation (2010)

Precision mirrors are required for effective solar energy collectors. Manufacturing such mirrors and making them robust to disturbances such as thermal gradients is expensive. In this paper, the use of parallel binary actuation to control the shape of mirrors for solar concentrators is explored. The approach embeds binary actuators in a compliant mirror substructure. Actuators are deployed in a specified pattern to correct the mirror shape. The analysis for binary-actuated compliant mirror structures is presented. Analytical models are developed for one-dimensional and two-dimensional compliant structures with embedded binary actuators. These analytical models are validated using finite element analysis and experimental studies. The models and experiments demonstrate the capabilities of binary actuated mirrors. System workspace is explored, the principle of superposition required for their control is demonstrated, as is the mirror ability to correct its figure.
Post-Fracturing Fluid-Recovery Enhancement With Microemulsion (2010)

Abstract The fields of East Kalimantan, Indonesia contain several depleted gas zones of medium permeability (0.1 to 300 mD). Though the permeability is quite good for gas bearing formations, the majority of the wells targeting these sands have failed to produce at expected rates. In the 1980s, hydraulic fracturing was introduced to the area in an attempt to increase production. The treatments yielded limited success with many wells actually producing less after being fractured. This led operators in the area to believe that the formations could be water sensitive with damage from the injected fluids causing the poor results after fracturing. As laboratory testing has ruled out water-sensitive mineralogy, the suspected cause of damage has been attributed to a decrease in relative permeability to gas after the fracturing fluid has penetrated the pore throats (water block). The water block conclusion is supported by the low percentage of injected fluids that are returned after the treatment. In 2007, VICO performed four fracturing treatments using a conventional surfactant to aid in post-frac cleanup. Only 2 of the 4 wells that were fractured produced after the treatment. Again, a common problem between the wells was the poor return of treatment fluids during cleanout. The limited success of these treatments indicated the water block issue had not been resolved. After reviewing the results of the first four wells, three additional fracturing treatments were placed in similar reservoirs using a microemulsion additive instead of the surfactant. Though laboratory testing in cores between 1 and 8.5mD failed to show a significant difference between the microemulsion and surfactant, the wells fractured with the microemulsion additive consistently outperformed those fractured previously in terms of returned treatment fluids and incremental production. Paktinat et al. (2006) wrote that the use of fracturing fluids with microemulsion in unconventional tight gas reservoirs can help increase production by increasing the relative permeability to gas in the area surrounding the fracture. Our study shows that similar benefits can also be achieved in depleted gas reservoirs with permeabilities greater than 1 mD, even if the benefits can not be clearly demonstrated under laboratory conditions.
Formation of Functionalized 2H-Azirines through PhIO-Mediated Trifluoroethoxylation and Azirination of Enamines (2013)

A variety of enaminones and enamine carboxylic esters were converted to trifluoroethoxylated 2H-azirines through reactions with PhIO in trifluoroethanol (TFE). The cascade reaction is postulated to proceed via a PhIO-mediated oxidative trifluoroethoxylation and a subsequent azirination of the α-trifluoroethoxylated enamine intermediates.
Parallel processing control of a joint manipulator. (1985)

A multi-microprocessor system (N-1) has been developed for machinery control. It is composed of 64 microprocessor units and an inter-processor communication system. Main objectives of N-1 are (1) to realize clear software structure by using dedicated processors for independent functions, (2) to make it possible to execute complicated tasks in real time by means of parallel processing capability and (3) to realize high reliability through redundant configuration. N-1 is connected with a manipulator which has six joints in order to investigate its performance. Parallel software for manipulator control and fault tolerant processing are developed and implemented on N-1. It is confirmed by experiments and analysis that N-1 has enough processing capability and flexibility to realize the main objectives.
Results of Fielded Module Analysis and the Development of Accelerated Module Durability Test Protocols to Better Predict Real-Life Performance (2014)

To better understand the performance and degradation mechanisms of photovoltaic modules in the service environment, we have inspected and characterized more than 60 global installations with more than 1.5 million modules (&gt;200 MW) in Europe, Israel, China, Japan, India, Canada, and United States. These inspections covered a range of installation types, climates, and ages ranging from newly commissioned to 30 years of operation. Modules were inspected and evaluated in the field and then selected modules were removed for further analysis in the laboratory. Both photovoltaic performance and failure analyses were done using a range of physical and chemical methods. This allowed characterization of failure modes and degradation, and provided critical guidance in the development of accelerated durability test protocols in order to better predict module performance and lifetime. The data and analysis from these fielded modules was used with environmental data to re-design single stress accelerated test protocols, including UV exposure and damp heat. Combined stress tests (simultaneous and sequential) were also designed and investigated to better match the service environment. These tests were then applied with modules using different materials and processing to understand the impact of materials and process changes, such as backsheet changes, on module performance. By comparing the results of these accelerated tests to the fielded modules we gained insights into the ability of these accelerated tests to predict field performance and the role of different materials in affecting module performance and reliability.
Efficient and Practical Synthesis of Sulfonamides Utilizing SO2 Gas Generated On Demand (2020)

A simple and practical protocol was developed for the synthesis of sulfonamides by reacting organometallic reagents with SO2 gas generated on demand. SO2 was generated from readily available reagents safely in a highly contained and controlled fashion. The protocol allows the synthesis of sulfonamides without using either atom-inefficient SO2 surrogates or a SO2 cylinder that requires stringent storage regulations in the laboratory. The protocol was successfully applied to the synthesis of sildenafil.
Management and Risk Assessment of Sabellid Polychaete Infestations in Abalone Mariculture Facilities (1996)

In October 1993, growers at some commercial abalone mariculture facilities (AMFs) in Southern California brought an interesting sabellid polychaete to our attention.The worm infested shells of cultured red abalone, Haliotis rufescens. Heavily infested abalone ceased growth. Their shells exhibited domed teratology often lacking respiratory holes. The worms appeared to bore into the shell.We discovered that all AMFs in California were infested; several were so heavily infested that domed specimens were abundant. The objectives of our study were to describe the worm (Associate principal investigator, K. Fitzhugh, Los Angeles County Museum of Natural History), investigate transmission to abalone, its mechanism of attachment and the cause of shell damage. We also examined the host specificity among common intertidal molluscs. In the course of our research we discovered that a natural rocky intertidal site at Cayucos, California had become infested. Here we sought to investigate how the worms had escaped into the adjacent facility, determine whether the worms had become established there, quantify transmission at that site and devise and supervise an eradication plan.
Anionic ring-opening alternating copolymerization of a bicyclic bis(.gamma.-lactone) with an epoxide: a novel ring-opening polymerization of a monomer containing a .gamma.-lactone structure (1993)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTAnionic ring-opening alternating copolymerization of a bicyclic bis(.gamma.-lactone) with an epoxide: a novel ring-opening polymerization of a monomer containing a .gamma.-lactone structureAtsuhito Tadokoro, Toshikazu Takata, and Takeshi EndoCite this: Macromolecules 1993, 26, 17, 4400–4406Publication Date (Print):August 1, 1993Publication History Published online1 May 2002Published inissue 1 August 1993https://pubs.acs.org/doi/10.1021/ma00069a002https://doi.org/10.1021/ma00069a002research-articleACS PublicationsRequest reuse permissionsArticle Views480Altmetric-Citations32LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts
Linear and Nonlinear Spectral Integration in Type IV Neurons of the Dorsal Cochlear Nucleus. II. Predicting Responses With the Use of Nonlinear Models (1997)

Two nonlinear modeling methods were used to characterize the input/output relationships of type IV units, which are one principal cell type in the dorsal cochlear nucleus (DCN). In both cases, the goal was to derive predictive models, i.e., models that could predict the responses to other stimuli. In one method, frequency integration was estimated from response maps derived from single tones and simultaneous pairs of tones presented over a range of frequencies. This model combined linear integration of energy across frequency and nonlinear interactions of energy at different frequencies. The model was used to predict responses to noisebands with varying width and center frequency. In almost all cases, predictions using two-tone interactions were better than linear predictions based on single-tone responses only. In about half the cases, reasonable quantitative fits were achieved. The fits were best for noisebands with narrow bandwidth and low sound levels. In the second nonlinear method, the spectrotemporal receptive field (STRF) was derived from responses to broadband stimuli. The STRF could account for some qualitative features of the responses to broad noisebands and spectral notches embedded in broad noisebands. Quantitatively, however, the STRFs failed to predict the responses of type IV units even to simple broadband noise stimuli. For narrowband stimuli, the STRF failed to predict even qualitative features (such as excitatory and inhibitory frequency bands). The responses of DCN type IV units presumably result from interactions of two inhibitory sources, a strong one that is preferentially activated by narrowband stimuli and a weaker one that is preferentially activated by broadband stimuli. The results presented here suggest that the STRF measures effects related to the broadband inhibition, whereas two-tone interactions measure mostly effects related to narrowband inhibition. This explains why models based on two-tone interactions predict the responses to narrow noisebands much better then models based on STRFs. It is concluded that a minimal stimulus set for characterizing type IV units must contain both broadband and narrowband stimuli, because each stimulus class by itself activates only partially the integration mechanisms that shape the responses of type IV units. Similar conclusions are expected to hold in other parts of the auditory system: when characterizing a complex auditory unit, it is necessary to use a range of stimuli to ensure that all integration mechanisms are activated.
Review of the Influence of Pigment Dispersion and Exfoliation Glaucoma Diagnosis on Intraocular Pressure in Clinical Trials Evaluating Primary Open-angle Glaucoma and Ocular Hypertension (2012)

Trial designs for prospective, parallel, glaucoma clinical studies that are performed in the United States generally can include PD and XFG patients with only a small impact on the IOP and a low number of such subjects enrolled.
Effect of magnetic field profile on the anode fall in a Hall-effect thruster discharge (2006)

The effect of the magnetic field configuration on the anode fall in an E⃗×B⃗ discharge of a Hall thruster is studied both experimentally and theoretically. Plasma potential, electron temperature, and plasma density in the near-anode region are measured with a biased probe in three configurations of the magnetic field. It is observed that the anode fall in a Hall thruster can be changed from negative to positive by creating a magnetic field configuration with a zero magnetic field region. Similar configurations are utilized in some advanced Hall thrusters, like an ATON thruster. Results of the measurements are employed to model a Hall thruster with different magnetic field configurations, including the one with a zero-field region. Different anode sheath regimes observed experimentally are used to set the boundary conditions for the quasineutral plasma. Numerical solutions obtained with a hydrodynamic quasi-one-dimensional model suggest that varying the magnetic field configuration affects the electron mobility both inside and outside the channel, as well as the plasma density distribution along the axis.
Modeling and Design of a UV Disinfection System Employing Excimer Lamps (2007)

Modeling and Design of a UV Disinfection System Employing Excimer LampsA non-mercury, excimer UV disinfection reactor was designed by integration of the results of numerical simulations based on computational fluid dynamics and an irradiance field model for cylindrical excimer lamps. The irradiance field model was developed based on the principle that excimer lamps emit radiation from a large number of point sources; the model incorporates calculations for...Author(s)Zorana NaunovicKelly L. PennellChengyue ShenPo-Shun ChanSoojung LimBeibei SunDennis A. LynErnest R. BlatchleySourceProceedings of the Water Environment FederationSubjectSession 115: UV Efficiency, Effectiveness and ApplicationsDocument typeConference PaperPublisherWater Environment FederationPrint publication date Oct, 2007ISSN1938-6478SICI1938-6478(20071001)2007:8L.8954;1-DOI10.2175/193864707787780648Volume / Issue2007 / 8Content sourceWEFTECFirst / last page(s)8954 - 8965Copyright2007Word count144Subject keywordsIRRADIANCE FIELD MODELINGEXCIMER LAMPXEBR ASTULTRAVIOLET DISINFECTION
Fracture behavior of a composite of bone and calcium sulfate/hydroxyapatite (2022)

Calcium sulfate/hydroxyapatite (CaS/HA) biomaterials have been investigated for use in several orthopedic applications. However, the mechanical interactions between the composite of CaS/HA and bone at the microscale are still unknown. The aim of this study was to determine if and how augmentation with CaS/HA alters the fracture behavior of bone. Eleven cylinders of trabecular bone were drilled from human femoral heads and cleaned from bone marrow. Among them, five cylinders were injected with CaS/HA to generate composite specimens, while the others were kept intact. One extra specimen of pure CaS/HA was prepared. All specimens were compressed in situ using synchrotron X-ray tomography and imaged at ∼2% strain intervals. Structural properties were calculated from the images in unloaded state and mechanical properties were determined from the load-curves. CaS/HA alone displayed the highest peak force and stiffness and the lowest strain at fracture. All composite specimens had a higher peak force than the pure bone specimens and the composite specimens had higher toughness than the pure CaS/HA specimen. Furthermore, the fracture behavior was analyzed further to characterize the local deformations. The pure bone specimens presented damage in multiple trabeculae and the CaS/HA specimen displayed sharp transition in strains, with low strain in one load step and large cracks in the next. The composite specimens deformed uniformly, with the CaS/HA preventing tissue damage and the bone preventing cracks in the CaS/HA from propagating through the specimen. In conclusion, using tomography with in situ loading, it was possible to show how CaS/HA can help prevent bone tissue damage before global failure.
Mondialisation de la communication, à la recherche du sens perdu (2009)

« Les vrais paradis sont les paradis qu’on a perdus »Marcel Proust La mondialisation* de la communication trouve ses racines dans des bases philosophiques et économiques remontant aux écrivains du siècle des Lumières et à l’économie classique. Dès 1833, E. G. Wakefield, auteur d’un ouvrage de référence sur la colonisation, éditeur d’Adam Smith et l’un des fondateurs du Commonwealth, écrivait : « Le monde entier est devant vous ». Il signifiait ainsi que le système économique capitaliste dispo...
Unsupervised Perceptual Rewards for Imitation Learning (2017)

Reward function design and exploration time are arguably the biggest obstacles to the deployment of reinforcement learning (RL) agents in the real world. In many real-world tasks, designing a reward function takes considerable hand engineering and often requires additional and potentially visible sensors to be installed just to measure whether the task has been executed successfully. Furthermore, many interesting tasks consist of multiple implicit intermediate steps that must be executed in sequence. Even when the final outcome can be measured, it does not necessarily provide feedback on these intermediate steps or sub-goals. To address these issues, we propose leveraging the abstraction power of intermediate visual representations learned by deep models to quickly infer perceptual reward functions from small numbers of demonstrations. We present a method that is able to identify key intermediate steps of a task from only a handful of demonstration sequences, and automatically identify the most discriminative features for identifying these steps. This method makes use of the features in a pre-trained deep model, but does not require any explicit specification of sub-goals. The resulting reward functions, which are dense and smooth, can then be used by an RL agent to learn to perform the task in real-world settings. To evaluate the learned reward functions, we present qualitative results on two real-world tasks and a quantitative evaluation against a human-designed reward function. We also demonstrate that our method can be used to learn a complex real-world door opening skill using a real robot, even when the demonstration used for reward learning is provided by a human using their own hand. To our knowledge, these are the first results showing that complex robotic manipulation skills can be learned directly and without supervised labels from a video of a human performing the task. Supplementary material and dataset are available at sermanet.github.io/rewards * equal contribution Google Brain Residency program (g.co/brainresidency)
Documenting Storm Severity in the Mid-Atlantic Region Using Lightning and Radar Information (2013)

Abstract Storm severity in the mid-Atlantic region of the United States is examined using lightning, radar, and model-derived information. Automated Warning Decision Support System (WDSS) procedures are developed to create grids of lightning and radar parameters, cluster individual storm features, and data mine the lightning and radar attributes of 1252 severe and nonsevere storms. The study first examines the influence of serial correlation and uses autocorrelation functions to document the persistence of lightning and radar parameters. Decorrelation times are found to vary by parameter, storm severity, and mathematical operator, but the great majority are between three and six lags, suggesting that consecutive 2-min storm samples (following a storm) are effectively independent after only 6–12 min. The study next describes the distribution of lightning jumps in severe and nonsevere storms, differences between various types of severe storms (e.g., severe wind only), and relationships between lightning and radar parameters. The 2σ lightning jump algorithm (with a 10 flashes min−1 activation threshold) yields 0.92 jumps h−1 for nonsevere storms and 1.44 jumps h−1 in severe storms. Applying a 10-mm maximum expected size of hail (MESH) threshold to the 2σ lightning jump algorithm reduces the frequency of lightning jumps in nonsevere storms to 0.61 jumps h−1. Although radar-derived parameters are comparable between storms that produce severe wind plus hail and those that produce tornadoes, tornadic storms exhibit much greater intracloud (IC) and cloud-to-ground (CG) flash rates. Correlations further illustrate that lightning data provide complementary storm-scale information to radar-derived measures of storm intensity.
Atom interferometer inertial force sensors (2003)

Summary form only given. Atom interferometer inertial force sensors offer the prospect of unprecedented performance for rotation, acceleration and gravity gradient measurements. The basic sensor operating principle is illustrated.