418 research outputs found
The Extreme Value Machine
It is often desirable to be able to recognize when inputs to a recognition
function learned in a supervised manner correspond to classes unseen at
training time. With this ability, new class labels could be assigned to these
inputs by a human operator, allowing them to be incorporated into the
recognition function --- ideally under an efficient incremental update
mechanism. While good algorithms that assume inputs from a fixed set of classes
exist, e.g., artificial neural networks and kernel machines, it is not
immediately obvious how to extend them to perform incremental learning in the
presence of unknown query classes. Existing algorithms take little to no
distributional information into account when learning recognition functions and
lack a strong theoretical foundation. We address this gap by formulating a
novel, theoretically sound classifier --- the Extreme Value Machine (EVM). The
EVM has a well-grounded interpretation derived from statistical Extreme Value
Theory (EVT), and is the first classifier to be able to perform nonlinear
kernel-free variable bandwidth incremental learning. Compared to other
classifiers in the same deep network derived feature space, the EVM is accurate
and efficient on an established benchmark partition of the ImageNet dataset.Comment: Pre-print of a manuscript accepted to the IEEE Transactions on
Pattern Analysis and Machine Intelligence (T-PAMI) journa
Analysis of the Spatial Dynamics of the American Lobster (Homarus Americanus) Fishery along the Coast of Maine
The American lobster (Homarus americanus) supports the most valuable commercial fishery in the northeastern United States, thus the fishery is critical to Maine\u27s economy. No systematic study has been done to collect information about, identify, and quantify the spatial dynamics of the Maine lobster fishery. This project helps to provide a better understanding of Maine\u27s lobster fishery dynamics, and it will aid f\u27iture efforts to improve the stock assessment of Maine\u27s lobster fishery. The analysis consists of three distinct parts: (1) comparison of data collected by two separate fishery dependent sampling programs; (2) spatial analysis of electronic logbook data; and (3) harbor gang temtoriality evidenced by electronic logbook data. The Maine Department of Marine Resources has established two fishery- dependent sampling programs: sea sampling and port sampling. Using data from 1998 - 2000, we evaluated the consistency in size composition and catch per unit of effort (CPUE) between the sea and port sampling programs. The overall pattern that emerged was a stronger relationship between sea and port sampling data over time from 1998- 2000, implying the two sampling programs were consistent in describing temporal variations in CPUE. This study suggests that either program should be sufficient in monitoring temporal trends of the lobster fishery. The American lobster fishery exhibits strong seasonal variations in spatial distributions of traps. In this study, we developed and applied two spatial statistical models, a moving window model and the empirical distribution function (EDF) model, to explore and describe data from the lobster fishery in order to quantify the spatial and temporal dynamics of fishing effort. This study suggests that fishing effort data were clustered rather than randomly distributed for the entire fishing season in the Stonington area. Therefore, we can state the data are not random in space or in time, but rather trap locations are clustered. Plots of nearest trap locations from May to December indicated that the trap locations were also not random at the smaller time scale. The nearest location distances of trap locations varied by month, but a general trend of decreased distances from May to September was observed, followed by increased distances from October to December. Electronic logbook data were displayed using GIs software to analyze the various boundaries observed by lobstermen. Management zone boundaries affected Stonington, Vinalhaven, Tenants Harbor, Spruce Head, New Harbor, and Long Island fishing areas to varying degrees in most seasons. Unofficial or territorial boundaries were assumed to have affected all areas, but some more obviously than others. Among these most affected were Stonington, Tenants Harbor, Port Clyde, Metinic, Round Pond, New Harbor, Cousins Island, and Harpswell. Territoriality among harbor gangs was shown to have at least partially structured the fishing areas observed through Thistle Marine data. These analyses have provided the DMR with important information on their current sampling programs, methodologies for future analysis of the fishery, and information affecting future management decisions and stock assessments
Subsurface Geometry of the San Andreas Fault in Southern California: Results from the Salton Seismic Imaging Project (SSIP) and Strong Ground Motion Expectations
The San Andreas fault (SAF) is one of the most studied strike‐slip faults in the world; yet its subsurface geometry is still uncertain in most locations. The Salton Seismic Imaging Project (SSIP) was undertaken to image the structure surrounding the SAF and also its subsurface geometry. We present SSIP studies at two locations in the Coachella Valley of the northern Salton trough. On our line 4, a fault‐crossing profile just north of the Salton Sea, sedimentary basin depth reaches 4 km southwest of the SAF. On our line 6, a fault‐crossing profile at the north end of the Coachella Valley, sedimentary basin depth is ∼2–3 km and centered on the central, most active trace of the SAF. Subsurface geometry of the SAF and nearby faults along these two lines is determined using a new method of seismic‐reflection imaging, combined with potential‐field studies and earthquakes. Below a 6–9 km depth range, the SAF dips ∼50°–60° NE, and above this depth range it dips more steeply. Nearby faults are also imaged in the upper 10 km, many of which dip steeply and project to mapped surface fault traces. These secondary faults may join the SAF at depths below about 10 km to form a flower‐like structure. In Appendix D, we show that rupture on a northeast‐dipping SAF, using a single plane that approximates the two dips seen in our study, produces shaking that differs from shaking calculated for the Great California ShakeOut, for which the southern SAF was modeled as vertical in most places: shorter‐period (T<1 s) shaking is increased locally by up to a factor of 2 on the hanging wall and is decreased locally by up to a factor of 2 on the footwall, compared to shaking calculated for a vertical fault
Spectral actinic flux in the lower troposphere: measurement and 1-D simulations for cloudless, broken cloud and overcast situations
In September 2002, the first INSPECTRO campaign to study the influence of clouds on the spectral actinic flux in the lower troposphere was carried out in East Anglia, England. Measurements of the actinic flux, the irradiance and aerosol and cloud properties were made from four ground stations and by aircraft. The radiation measurements were modelled using the uvspec model and ancillary data. For cloudless conditions, the measurements of the actinic flux were reproduced by 1-D radiative transfer modelling within the measurement and model uncertainties of about ±10%. For overcast days, the ground-based and aircraft radiation measurements and the cloud microphysical property measurements are consistent within the framework of 1-D radiative transfer and within experimental uncertainties. Furthermore, the actinic flux is increased by between 60-100% above the cloud when compared to a cloudless sky, with the largest increase for the optically thickest cloud. Correspondingly, the below cloud actinic flux is decreased by about 55-65%. Just below the cloud top, the downwelling actinic flux has a maximum that is seen in both the measurements and the model results. For broken clouds the traditional cloud fraction approximation is not able to simultaneously reproduce the measured above-cloud enhancement and below-cloud reduction in the actinic flux
LifeCLEF 2016: Multimedia Life Species Identification Challenges
International audienceUsing multimedia identification tools is considered as one of the most promising solutions to help bridge the taxonomic gap and build accurate knowledge of the identity, the geographic distribution and the evolution of living species. Large and structured communities of nature observers (e.g., iSpot, Xeno-canto, Tela Botanica, etc.) as well as big monitoring equipment have actually started to produce outstanding collections of multimedia records. Unfortunately, the performance of the state-of-the-art analysis techniques on such data is still not well understood and is far from reaching real world requirements. The LifeCLEF lab proposes to evaluate these challenges around 3 tasks related to multimedia information retrieval and fine-grained classification problems in 3 domains. Each task is based on large volumes of real-world data and the measured challenges are defined in collaboration with biologists and environmental stakeholders to reflect realistic usage scenarios. For each task, we report the methodology, the data sets as well as the results and the main outcom
Spectral actinic flux in the lower troposphere: measurement and 1-D simulations for cloudless, broken cloud and overcast situations
In September 2002, the first INSPECTRO campaign to study the influence of clouds on the spectral actinic flux in the lower troposphere was carried out in East Anglia, England. Measurements of the actinic flux, the irradiance and aerosol and cloud properties were made from four ground stations and by aircraft. The radiation measurements were modelled using the uvspec model and ancillary data. For cloudless conditions, the measurements of the actinic flux were reproduced by 1-D radiative transfer modelling within the measurement and model uncertainties of about ±10%. For overcast days, the ground-based and aircraft radiation measurements and the cloud microphysical property measurements are consistent within the framework of 1-D radiative transfer and within experimental uncertainties. Furthermore, the actinic flux is increased by between 60-100% above the cloud when compared to a cloudless sky, with the largest increase for the optically thickest cloud. Correspondingly, the below cloud actinic flux is decreased by about 55-65%. Just below the cloud top, the downwelling actinic flux has a maximum that is seen in both the measurements and the model results. For broken clouds the traditional cloud fraction approximation is not able to simultaneously reproduce the measured above-cloud enhancement and below-cloud reduction in the actinic flux
Tectonic and magmatic controls on hydrothermal activity in the Woodlark Basin
The Woodlark Basin is one of the rare places on earth where the transition from continental breakup to seafloor spreading can be observed. The potential juxtaposition of continental rocks, a large magmatic heat source, crustal-scale faulting, and hydrothermal circulation has made the Woodlark Basin a prime target for seafloor mineral exploration. However, over the past 20 years, only two locations of active hydrothermalism had been found. In 2009 we surveyed 435 km of the spreading axis for the presence of hydrothermal plumes. Only one additional plume was found, bringing the total number of plumes known over 520 km of ridge axis to only 3, much less than at ridges with similar spreading rates globally. Particularly the western half of the basin (280 km of axis) is apparently devoid of high temperature plumes despite having thick crust and a presumably high magmatic budget. This paucity of hydrothermal activity may be related to the peculiar tectonic setting at Woodlark, where repeated ridge jumps and a re-location of the rotation pole both lead to axial magmatism being more widely distributed than at many other, more mature and stable mid-ocean ridges. These factors could inhibit the development of both a stable magmatic heat source and the deeply penetrating faults needed to create long-lived hydrothermal systems. We conclude that large seafloor massive sulfide deposits, potential targets for seafloor mineral exploration, will probably not be present along the spreading axis of the Woodlark Basin, especially in its younger, western portion
Affective Man-Machine Interface: Unveiling human emotions through biosignals
As is known for centuries, humans exhibit an electrical profile. This profile is altered through various psychological and physiological processes, which can be measured through biosignals; e.g., electromyography (EMG) and electrodermal activity (EDA). These biosignals can reveal our emotions and, as such, can serve as an advanced man-machine interface (MMI) for empathic consumer products. However, such a MMI requires the correct classification of biosignals to emotion classes. This chapter starts with an introduction on biosignals for emotion detection. Next, a state-of-the-art review is presented on automatic emotion classification. Moreover, guidelines are presented for affective MMI. Subsequently, a research is presented that explores the use of EDA and three facial EMG signals to determine neutral, positive, negative, and mixed emotions, using recordings of 21 people. A range of techniques is tested, which resulted in a generic framework for automated emotion classification with up to 61.31% correct classification of the four emotion classes, without the need of personal profiles. Among various other directives for future research, the results emphasize the need for parallel processing of multiple biosignals
Expression of antisense or sense RNA of an ankyrin repeat-containing gene blocks chloroplast differentiation in arabidopsis.
The Arabidopsis AKR gene that encodes a protein with four ankyrin repeats (a 33-amino acid motif that appears in the 89K domain of the human protein ankyrin) was isolated and characterized. A short sequence outside the ankyrin repeats is similar to that of the protein of the Drosophila muscle segment homeobox (msh) gene. The expression of the AKR gene is light dependent, and transgenic Arabidopsis plants with two or more copies of an antisense or sense AKR construct became chlorotic in a developmentally regulated manner. The chlorotic phenotype was genetically transmitted to the next generation, although most chlorotic plants produced much less seed. Reduced presence of thylakoid membranes and loss of grana are found in the plastids of chlorotic leaves, indicating that antisense or sense AKR has blocked chloroplast differentiation. This study indicates the importance of ankyrin repeat-containing proteins, not only in yeast and animals, but in plants as well
Distribution of Isolated Volcanoes on the Flanks of the East Pacific Rise, 15.3°-20°S
Volcanic constructions, not associated with seamount (or volcano) chains, are abundant on the flanks of the East Pacific Rise (EPR) but are rare along the axial high. The distribution of isolated volcanoes, based on multibeam bathymetric maps, is approximately symmetric about the EPR axis. This symmetry contrasts with the asymmetries in the distribution of volcano chains (more abundant on the west flank), the seafloor subsidence rates (slower on the west flank), and the distribution of plate-motion-parallel gravity lineaments (more prominento nthe west flank). Most of the isolated volcanoes complete their growth within -14 km of the axis on crust younger than 0.2 Ma, while seamount chain volcanoes continue to be active on older crust. Volcanic edifices within 6 km of the ridge axis are primarily found adjacent to axial discontinuities, suggesting a more sporadic magma supply and stronger lithosphere able to support volcanic constructions near axial discontinuities. The volume of isolated near-axis volcanoes correlates with ridge axis cross-sectional area, suggesting a link between the magma budget of the ridge and the eruption of near-axis volcanoes. Within the study area, off-axis volcanic edifices cover at least 6% of the seafloor and contribute more than 0.2% to the volume of the crust. The inferred width of the zone where isolated volcanoes initially form increases with spreading rate for the Mid-Atlantic Ridge (\u3c4 km), northern EPR (\u3c20 km), and southern EPR(\u3c28 km), so that isolated volcanoes form primarily on lithosphere younger than 0.2 Ma (\u3c 4-6 km brittle thickness), independent of spreading rate. This suggests some form of lithospheric control on the eruption of isolated off-axis volcanoes due to brittle thickness, increased normal stresses across cracks impeding dike injection, or thermal stresses within the newly forming lithosphere
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