Input Signature Research Articles

A Deep Neural Network for Unsupervised Anomaly Detection and Diagnosis in Multivariate Time Series Data

Nowadays, multivariate time series data are increasingly collected in various real world systems, e.g., power plants, wearable devices, etc. Anomaly detection and diagnosis in multivariate time series refer to identifying abnormal status in certain time steps and pinpointing the root causes. Building such a system, however, is challenging since it not only requires to capture the temporal dependency in each time series, but also need encode the inter-correlations between different pairs of time series. In addition, the system should be robust to noise and provide operators with different levels of anomaly scores based upon the severity of different incidents. Despite the fact that a number of unsupervised anomaly detection algorithms have been developed, few of them can jointly address these challenges. In this paper, we propose a Multi-Scale Convolutional Recurrent Encoder-Decoder (MSCRED), to perform anomaly detection and diagnosis in multivariate time series data. Specifically, MSCRED first constructs multi-scale (resolution) signature matrices to characterize multiple levels of the system statuses in different time steps. Subsequently, given the signature matrices, a convolutional encoder is employed to encode the inter-sensor (time series) correlations and an attention based Convolutional Long-Short Term Memory (ConvLSTM) network is developed to capture the temporal patterns. Finally, based upon the feature maps which encode the inter-sensor correlations and temporal information, a convolutional decoder is used to reconstruct the input signature matrices and the residual signature matrices are further utilized to detect and diagnose anomalies. Extensive empirical studies based on a synthetic dataset and a real power plant dataset demonstrate that MSCRED can outperform state-ofthe-art baseline methods.

The sediment‐fill of Pago Pago Bay (Tutuila Island, American Samoa): New insights on the sediment record of past tsunamis

AbstractExtensive bathymetric and two‐dimensional seismic surveys have been carried out and cores collected in Pago Pago Bay (Tutuila, American Samoa) in order to describe and gain a better understanding of the sediment fill of the bay, which was affected by the 2009 South Pacific Tsunami. Eight sedimentary units were identified over the volcanic bedrock. The basal transgressive unit displays retrograding onlaps towards the shore, whereas the overlying seven aggradational layers alternate between four draping units and three pinching out seaward units. ‘Core to seismic’ correlation reveals that draping units are composed of homogeneous silts, while pinching out units are dominated by very coarse coral fragments showing fresh cuts, mixed with Halimeda plates. The basal unit is attributed to transgressive sedimentation in response to flooding of the bay after the last glacial maximum, followed by the upper aggradational units corresponding to highstand sedimentation. The changeovers in these upper units indicate an alternation between low‐energy silt units and high‐energy coral debris units interpreted as tsunami‐induced deposits. The 14C dating reveals that high‐energy sedimentation units can last up to approximately 2000 years while low‐energy sedimentation units can last up to approximately 1000 years. This alternation, deposited during the last highstand, may be explained by cycles of tectonic activity and quiescence of the Tonga Trench subduction, which is the main source of tsunamigenic earthquakes impacting the Samoan archipelago. In the uppermost silt unit, only the geochemical signature of the terrestrial input of the 2009 SPT backwash deposits was detected between 7 cm and 9 cm depth. Hence, Pago Pago Bay offers a unique sediment record of Holocene bay‐fill under the impact of past tsunamis intermittently during the last 7000 years.

Nitrogen Inputs by Marine Vertebrates Drive Abundance and Richness in Antarctic Terrestrial Ecosystems

Biodiversity is threatened by climate change and other human activities [1], but to assess impacts, we also need to identify the current distribution of species on Earth. Predicting abundance and richness patterns is difficult in many regions and especially so on the remote Antarctic continent, due to periods of snow cover, which limit remote sensing, and the small size of the biota present. As the Earth's coldest continent, temperature and water availability have received particular attention in understanding patterns of Antarctic biodiversity [2], whereas nitrogen availability has received less attention [3]. Nitrogen input by birds is a major nutrient source in many regions on Earth [4-7], and input from penguins and seals is associated with increased plant growth [8-10] and soil respiration [11-13] at some Antarctic locations. However, the consequences of increased nitrogen concentrations in Antarctic mosses and lichens for their associated food web has hardly been addressed [14, 15], despite the fact that nutrient status of primary producers affects the abundance and diversity of higher trophic levels [16, 17]. We show that nitrogen input and δ15N signatures from marine vertebrates are associated with terrestrial biodiversity hotspots well beyond (>1,000 m) their immediate colony borders along the Antarctic Peninsula. Invertebrate abundance and richness was two to eight times higher under penguin and elephant seal influence. The nitrogen footprint area was correlated with the vertebrate population size. These findings improve our ability to predict biogeographical patterns of Antarctic terrestrial biodiversity through knowledge of the location and size of penguin and elephant seal concentrations.

Tracing of Cl input into the sub-arc mantle through the combined analysis of B, O and Cl isotopes in melt inclusions

The effect that recycling crust and sediments have on the composition of the mantle wedge, in particular in terms of volatiles, is still debated. Chlorine, an important fluid mobile element that has stable isotopes with different concentrations in the terrestrial reservoirs, has the potential to be used to trace slab-derived fluids.Olivine-hosted melt inclusions (OHMIs) provide a first order constraint on the δ37Cl of primary magmas, since they are unaffected by near surface processes. In this study, δ37Cl were coupled with δ11B and δ18O analyses in samples from the Lesser Antilles, Vanuatu, Aeolian, NE Japan and Izu-Bonin arcs. This unique dataset is used to better understand the large δ37Cl variation in melt inclusions from a single sample. OHMIs from the Vulcano (Aeolian arc) and Sukumoyama (Izu-Bonin arc) samples have similar δ37Cl (−2.5 ± 0.5‰ and −2.6 ± 0.8‰, respectively). These are different from δ37Cl in OHMIs from the other three localities (δ37Cl of −0.7 ± 0.6‰ for Aoba (Vanuatu arc) and St. Vincent (Lesser Antilles arc), −1 ± 0.9‰ for Iwate (NE Japan)). Vulcano OHMIs also have statistically different B and O isotope compositions compared to those from the other locations: average δ11B of −5.1 ± 2.9‰ for Vulcano OHMIs, compared to 2.5 ± 3.7‰, 5.2 ± 1.4‰, 7.0 ± 2.2‰, 3.8 ± 7.5‰ for Sukumoyama, Iwate, Aoba and St. Vincent OHMIs, respectively. All OHMIs have δ18O between 4.0 and 7.4‰, except for those from Vulcano, which are significantly different, with δ18O from 7.2 to 9.1‰. Combining these three stable isotope systems suggests that the large variation (>2‰) of δ37Cl in OHMIs from a sample reflects inputs from different sources of Cl rather than heterogeneities in a single main source. Variability between arcs might reflect different major sources of Cl.Comparing OHMIs Cl isotope data from the Aeolian and Izu-Bonin arcs with existing bulk rock Cl isotope data suggest that OHMIs preserve the source signature of Cl input whereas this signal can be lost in whole rocks as a result of Cl isotope diffusive fractionation during Cl degassing. SIMS measurements of Cl isotopes in OHMIs could thus help refine models of Cl cycles in the mantle.

Dredging and canal gate technologies in Portus, the ancient harbour of Rome, reconstructed from event stratigraphy and multi-proxy sediment analysis

Ancient harbours are rich archives of human-environment interaction. However, dating harbour deposits and correlating their stratigraphy is a major challenge because of typically high sedimentation rates over short periods and possible curative dredging events. Portus, the maritime harbour of Rome at the height of the Roman Empire, was a port complex composed of basins and canals connecting the commercial harbour to Rome via the Tiber River. Sediment core CPS1 in the narrowest of these canals, Canale Traverso, is located centrally in what was the capital city's commercial hub and contains a continuous harbour depositional record with average sedimentation rates greater than 1 cm per year. Here we use piston coring, high-resolution core scanning and a multi-proxy sediment analysis including for the first time paleo- and rock-magnetism, and bulk and clay mineralogy in order to overcome the problems of dating harbour deposits and correlating their stratigraphy. The method allowed precise identification of major reworked events, including a dredged deposit and a hyperpycnal deposit, which improve the chronostratigraphy and water depth reconstruction, and sheds light on harbour technologies at the height of the Roman Empire. A debris layer with abundant ceramic fragments and rocks marks the decommissioning of Canale Traverso and provides a new chronostratigraphic marker at Portus. Multi-proxy riverine input signatures point to the possible use of canal gate technology for water flow management.

Testing ripple carry adder using bist architecture

Very Large-Scale Integration has a greater impact on the developing circuit technology. The Cost and Size has been gradually reducing since years but increased the circuit complexity, there are problems which may affect the growth of VLSI technology. Among them one of major problem is circuit testing. To resolve this issue, we implement Built in Self-Test (BIST). BIST architecture is used to test the circuit itself. Engineers Design BIST to achieve high reliability and low repair cycle times. We implement Linear Feedback Shift Registers (LFSR) to generate the pseudo random test pattern and implement a ripple carry adder as circuit under test and Multiple Input Signature Register(MISR) as output response analyzer and test patterns are given to circuit under test and outputs are obtained these are compared with the actual outputs to test whether the circuit is faulty or not. To check whether the circuit is faulty or fault free we check the obtained outputs with actual outputs using Signature Analysis.

Are boron isotopes a reliable tracer of anthropogenic inputs to rivers over time?

This study aims at determining how the boron signal of the Seine River evolved in terms of concentration and isotopic signatures over eighteen years (1994–95 and 2006–12) and if boron isotopes can reliably trace anthropogenic inputs over time. In the anthropised Seine River watershed, boron is widely released by human activities, and even if boron concentrations ([B]) are below the potability limit, our study confirms the potential of boron isotopes (δ11B) to trace urban anthropogenic contaminations. Between 1994 and 2012, [B] have decreased across the anthropised part of the Seine River basin (and by a factor of two in Paris) while δ11B has increased. This means either that urban inputs have been reduced or that the boron signature of urban inputs has changed over time. Both hypotheses are in agreement with the decrease of perborate consumption in Europe over 15years and are not mutually exclusive.Results of a thorough analysis of urban effluents from the sewage network of Paris conurbation that are in fine released to the Seine River suggest a shift of the urban δ11B from −10‰ in 1994 to 1.5±2.0‰ in 2012, in agreement with our second hypothesis. We attribute this change to the removal of perborates from detergents rather than to the modernisation of wastewater treatment network, because it does not significantly impact the wastewater boron signatures. Eighteen years after the first assessment and despite the decreased use of perborates, geochemical and isotopic mass budgets confirm, that boron in the Seine River basin is mainly released from urban activities (60–100%), especially in Paris and the downstream part of the basin. Contrastingly, in headwaters and/or tributaries with low urbanisation, the relative boron input to river from agricultural practices and rains increased, up to 10% and by 10 to 30%, respectively.

Agricultural land use change impacts soil CO2 emission and its 13C-isotopic signature in central China

Land use change has been widely considered as a key driver of global carbon (C) dynamics. However, the impact of agricultural land use change on soil respiration and its 13C-isotopic signature of CO2 are not fully understood. Therefore, we conducted a field experiment to investigate the seasonal variation of soil CO2 flux and its 13C-isotopic signature and their relationships with biotic factors and abiotic factors under land use conversion from croplands to afforested land (woodland and shrubland) after 30 years. Measurement of CO2 flux was conducted once a month for a whole year. The results showed that the conversion cropland to afforested land significantly increased soil CO2 flux and lowered the δ13C of soil CO2. The soil CO2 flux showed similar seasonal patterns among land use types with the highest (994.87 mg m−2 h−1) in summer and the lowest (25.53 mg m−2 h−1) in winter. The soil CO2 flux was positively related to soil organic C and labile C of topsoil (0–10 cm), as well as soil temperature, whereas the δ13C of soil CO2 emission was positively correlated with the δ13C of microbial biomass and negatively correlated with soil temperature. Overall, our results reveal that subject to long-term land use change, soil CO2 fluxes significantly increase in afforested land due to improved availability of soil C, and its 13C-isotopic signature are strongly related to isotope signature of plant litter inputs.

TEST REGISTER INSERTION AT RTL BASED ON REDUCED BIST

Built-in self-test (BIST) method has high area overhead and long test application time. In this paper, a new BIST method is proposed at register transfer level (RTL) as a design for testability (DFT) method to modify a given RTL circuit to a reduced BIST-able RTL circuit. First, we introduce modelling method called extended R-graph to represent the register connectivity of an RTL circuit. The original register in the RTL circuit is modified into multiple input signature registers (MISRs) as test register. The selection of MISR is performed by extended minimum feedback vertex set (MFVS) algorithm that identifies a set of vertices (representing test register) which breaks all the loops of extended R-graph with minimal cost when vertices are removed. It has been proven through simulation that the proposed BIST method has lower area overhead of 32.9% on average and achieves comparably high fault coverage compared to the previous method, concurrent BIST using ITC'99 benchmark circuits.

Micromotion dynamics and geometrical shape parameters estimation of exoatmospheric infrared targets

The micromotion dynamics and geometrical shape are considered to be essential characteristics for exoatmospheric targets discrimination. Many methods have been investigated to retrieve the micromotion features using radar signals returned from targets of a given shape. We explore a way of jointly estimating micromotion dynamics and geometrical shape parameters from the infrared (IR) signals of targets in remote detection distance. It is found that the micromotion dynamics of the target would induce a periodic fluctuating variation on the IR irradiance intensity signature. In addition to the micromotion characteristics, the fluctuation could also reflect target structure properties, which offer a possible clue in extracting the features of micromotion dynamics and geometrical shape. Thus, the data model of target IR irradiance intensity signatures induced by micromotion patterns including spinning, coning, and tumbling is developed, and a method of parameters estimation based on joint optimization analysis techniques is proposed. Experimental results demonstrated that the parameters of target micromotion dynamics and geometrical shape can be effectively estimated using the proposed method, if the input signature contains multiple dominant frequency components.

Visual cortex responses reflect temporal structure of continuous quasi-rhythmic sensory stimulation

Neural processing of dynamic continuous visual input, and cognitive influences thereon, are frequently studied in paradigms employing strictly rhythmic stimulation. However, the temporal structure of natural stimuli is hardly ever fully rhythmic but possesses certain spectral bandwidths (e.g. lip movements in speech, gestures). Examining periodic brain responses elicited by strictly rhythmic stimulation might thus represent ideal, yet isolated cases. Here, we tested how the visual system reflects quasi-rhythmic stimulation with frequencies continuously varying within ranges of classical theta (4–7Hz), alpha (8–13Hz) and beta bands (14–20Hz) using EEG. Our findings substantiate a systematic and sustained neural phase-locking to stimulation in all three frequency ranges. Further, we found that allocation of spatial attention enhances EEG-stimulus locking to theta- and alpha-band stimulation. Our results bridge recent findings regarding phase locking (“entrainment”) to quasi-rhythmic visual input and “frequency-tagging” experiments employing strictly rhythmic stimulation. We propose that sustained EEG-stimulus locking can be considered as a continuous neural signature of processing dynamic sensory input in early visual cortices. Accordingly, EEG-stimulus locking serves to trace the temporal evolution of rhythmic as well as quasi-rhythmic visual input and is subject to attentional bias.

Can SNOMED CT be squeezed without losing its shape?

BackgroundIn biomedical applications where the size and complexity of SNOMED CT become problematic, using a smaller subset that can act as a reasonable substitute is usually preferred. In a special class of use cases—like ontology-based quality assurance, or when performing scaling experiments for real-time performance—it is essential that modules show a similar shape than SNOMED CT in terms of concept distribution per sub-hierarchy. Exactly how to extract such balanced modules remains unclear, as most previous work on ontology modularization has focused on other problems. In this study, we investigate to what extent extracting balanced modules that preserve the original shape of SNOMED CT is possible, by presenting and evaluating an iterative algorithm.MethodsWe used a graph-traversal modularization approach based on an input signature. To conform to our definition of a balanced module, we implemented an iterative algorithm that carefully bootstraped and dynamically adjusted the signature at each step. We measured the error for each sub-hierarchy and defined convergence as a residual sum of squares <1.ResultsUsing 2000 concepts as an initial signature, our algorithm converged after seven iterations and extracted a module 4.7 % the size of SNOMED CT. Seven sub-hierarhies were either over or under-represented within a range of 1–8 %.ConclusionsOur study shows that balanced modules from large terminologies can be extracted using ontology graph-traversal modularization techniques under certain conditions: that the process is repeated a number of times, the input signature is dynamically adjusted in each iteration, and a moderate under/over-representation of some hierarchies is tolerated. In the case of SNOMED CT, our results conclusively show that it can be squeezed to less than 5 % of its size without any sub-hierarchy losing its shape more than 8 %, which is likely sufficient in most use cases.

Flexible Neural Network Architecture for Handwritten Signatures Recognition

Abstract This article illustrates modeling of flexible neural networks for handwritten signatures preprocessing. An input signature is interpolated to adjust inclination angle, than descriptor vector is composed. This information is preprocessed in proposed flexible neural network architecture, in which some neurons are becoming crucial for recognition and adapt to classification purposes. Experimental research results are compared in benchmark tests with classic approach to discuss efficiency of proposed solution.

Characterisation of hydraulic and hydrogeochemical processes in a reducing and alkalinity-producing system (RAPS) treating mine drainage, South Wales, UK

A series of tracer tests has been carried out in the compost and limestone Tan-y-Garn Reducing and Alkalinity-Producing System (RAPS), designed to treat iron-rich net acidic mine water (mean pH6.18, Fe=47mgL−1, alkalinity 1.70meqL−1 and mineral acidity 1.82meqL−1) in South Wales, UK. Conservative tracer breakthrough time in the RAPS basal effluent is approximately inversely related to throughflow rate. Repeat tracer tests indicate a long term decrease in hydraulic conductivity, but not in total porosity.A specific sodium chloride tracer test from June 2008 is reported, when 15kg salt was added to a raw mine water inflow rate of 0.87Ls−1. Electrical conductivity and major ion chemistry were monitored for a 170h period. Sodium exhibited a retardation of 1.15 to 1.2 in the RAPS medium relative to chloride, due to cation exchange. Simple 1-D advection-diffusion analytical modelling succeeded in simulating the early portion of tracer breakthrough in the RAPS effluent. More complex analytical modelling, accounting for (i) mixing and dilution effects in the supernatant water input signature and (ii) matrix diffusion effects, was found to be required to adequately simulate the later-stage tail of the breakthrough curve in the RAPS effluent.

Molybdenum isotope systematics in subduction zones

Abstract This study presents Mo isotope data for arc lavas from different subduction zones that range between δ 98 / 95 Mo = − 0.72 and + 0.07 ‰ . Heaviest isotope values are observed for the most slab fluid dominated samples. Isotopically lighter signatures are related to increasing relevance of terrigenous sediment subduction and sediment melt components. Our observation complements previous conclusions that an isotopically heavy Mo fluid flux likely mirrors selective incorporation of isotopically light Mo in secondary minerals within the subducting slab. Analogue to this interpretation, low δ 98 / 95 Mo flux that coincides with terrigenous sediment subduction and sediment melting cannot be simply related to a recycled input signature. Instead, breakdown of the controlling secondary minerals during sediment melting may release the light component and lead to decreasing δ 98 / 95 Mo influx into subarc mantle sources. The natural range between slab dehydration and hydrous sediment melting may thus cause a large spread of δ 98 / 95 Mo in global subduction zone magmas.

Authentication System for Any Touch Devices Using DWT

In today's world, the identification techniques based on human biometric features gaining much more importance. For e.g. Iris recognition system, face recognition system, finger print recognition system, retina scanning system, etc. Some important area of other techniques is also to recognize the human hand signature. Also, there is the requirement of some techniques which works automatically based on some standard computer algorithms for recognition. For e.g. to identify the criminal identity automatically based on biometric features. The aim of research is to develop an on-line system for signature verification using Discrete Wavelet Transform (DWT). Discrete Wavelet Transform (DWT) algorithm is used for features extraction. In online signature dynamic features are usually available. Genuine or Forgery signature is substantiating based features comparison. Each feature of an input signature is extracted using various steps discrete wavelet transform algorithm are matched against a reference signature to identify the genuine signature. The final decision of verification is made based on the matched features of both the signatures.

Application of the Frequency Spectrum to Spectral Similarity Measures

Several frequency-based spectral similarity measures, derived from commonly-used ones, are developed for hyperspectral image classification based on the frequency domain. Since the frequency spectrum (magnitude spectrum) of the original signature for each pixel from hyperspectral data can clearly reflect the spectral features of different types of land covers, we replace the original spectral signature with its frequency spectrum for calculating the existing spectral similarity measure. The frequency spectrum is symmetrical around the direct current (DC) component; thus, we take one-half of the frequency spectrum from the DC component to the highest frequency component as the input signature. Furthermore, considering the fact that the low frequencies include most of the frequency energy, we can optimize the classification result by choosing the ratio of the frequency spectrum (from the DC component to the highest frequency component) involved in the calculation. In our paper, the frequency-based measures based on the spectral gradient angle (SAM), spectral information divergence (SID), spectral correlation mapper (SCM), Euclidean distance (ED), normalized Euclidean distance (NED) and SID × sin(SAM) (SsS) measures are called the F-SAM, F-SID, F-SCM, F-ED, F-NED and F-SsS, respectively. In the experiment, three commonly-used hyperspectral remote sensing images are employed as test data. The frequency-based measures proposed here are compared to the corresponding existing ones in terms of classification accuracy. The classification results by parameter optimization are also analyzed. The results show that, although not all frequency-based spectral similarity measures are better than the original ones, some frequency-based measures, such as the F-SsS and F-SID, exhibit a relatively better performance and have more robust applications than the other spectral similarity measures.

Changes to nitrate isotopic composition of wastewater treatment effluent and rivers after upgrades to tertiary treatment in the Narragansett Bay watershed, RI

Due to nitrogen load reduction policies, wastewater treatment facilities (WWTFs) have upgraded to tertiary treatment — where denitrification reduces and removes nitrogen. Changes to the stable isotopic composition of nitrate inputs after upgrades or how it transfers to the estuary have not been assessed in Rhode Island. We investigate whether these upgrades impact the isotopic signature of nitrate inputs to Narragansett Bay. Samples from rivers and WWTFs discharging to Narragansett Bay characterize the anthropogenic source nitrate (NO3−) isotopic composition (δ15N–NO3− and δ18O–NO3−) and temporal variability. At one WWTF, tertiary treatment increased effluent nitrate δ15N–NO3− and δ18O–NO3− values by ~16‰. Riverine values increased by ~4‰, likely due to the combination of decreases in N and upgrades. Combined river and WWTF flux-weighted isotopic compositions showed enriched values and an amplitude reduction in monthly variability. When seasonal isotopic means are significantly different from other sources, δ15N–NO3− may be a useful tracer of inputs.

Geochemistry of Tri- and Tetracyclic Terpanes in the Palaeozoic Oils from the Tarim Basin, Northwest China

Tri- and tetracyclic terpanes in oils and gas condensates from the cratonic region of the Tarim Basin have been characterized by gas chromatography–mass spectrometry to investigate their geochemical applications in organic source input and maturity assessment. Most oils show typical marine source input characterized by the dominance of C23 tricyclic terpane (TT), low C19TT, and low C24 tetracyclic terpane (TeT), while some oils/condensates show typical terrigenous input signatures as indicated by the dominance of C19TT and C24TeT, which is obviously in conflict with early Palaeozoic geological settings. Commonly used organic source input parameters, such as C19TT/C20TT, C24TeT/C26TT, and C20TT/C23TT, show complicated correlation to maturity parameters. C19TT/C20TT ratios are positively correlated to n-C18/phytane (Ph), while C24TeT/C26TT and C20TT/C23TT ratios increase with n-C18/Ph in a narrow maturity range and then decrease at an extremely high maturity level. Unusually high C19TT/C20TT, C20TT/C23TT, a...

A New Approach to the Handwritten Signature Verification Based on the Method of the Normalized Distributions

In this paper introduces approach identification based on the handwritten signature and an method for Verification Data Handwritten Signature based on a normalization of measurement data from special device input signatures. This approach reduces the computational complexity of identification and can be used to many fields for the classification tasks and the secure transmission between two or more systems involved in communication.