Reliable Anchors Research Articles

Ensuring the Stability of Channel Linings Under Unsteady Filtration

When assessing the stability of the slopes of the banks of reservoirs and channels, the filtration regime that occurs with a rapid decrease in the water level in the upstream, which is due to the nature of the operation of structures before floods, discharges, emergency situations, is of particular interest. A change in the water levels in the upstream causes a change in the position of the depression surface and the parameters of the filtration flow (pressure gradients, filtration rates and flow rates) in the coastal massif. At the same time, unsteady filtration occurs in the coastal massif and the stability of the slopes is reduced significantly due to the action of hydrodynamic forces directed towards the slope. The most reliable anchors of channel slopes in similar conditions are those that, under normal channel operation, when there is no groundwater support, the lining should exclude filtration from the channel, ie filtration losses of irrigated water, and if there is a backwater and with a rapid decrease in the water level in the channel, it should provide free access of the ground stream into the channel channel or its diversion in the other direction. This eliminates the occurrence of significant hydrodynamic pressures, and the destruction of the channel slope fasteners. The article presents the results of studies of 4 designs of channel linings operating under conditions of unsteady filtration. In the course of the study, we considered the following variants of structural schemes of linings. Fastening with combined deformation and filtration seams; fastening with self-collapsing seams; fastening with discharge tubular drains with water discharge into the channel; fastening with filtration and discharge holes arranged during the appearance of groundwater backup in the channel area. The results of calculating the stability of the fastening plates for overturning and surfacing are presented. According to the results of the calculation, the most acceptable fastening options are determined, their advantages and disadvantages are given. The proposed fastening design meets the above requirements and thereby ensures the strength and stability of the linings during the operation of the channel.

Reference-Guided Landmark Image Inpainting With Deep Feature Matching

Despite impressive progress made by recent image inpainting methods, they often fail to predict the original content when the corrupted region contains unique structures, especially for landmark images. Applying similar images as a reference is helpful but introduces a style gap of textures, resulting in color misalignment. To this end, we propose a style-robust approach for reference-guided landmark image inpainting, taking advantage of both the representation power of learned deep features and the structural prior from the reference image. By matching deep features, our approach builds style-robust nearest-neighbor mapping vector fields between the corrupted and reference images, in which the loss of information due to corruption leads to mismatched mapping vectors. To correct these mismatched mapping vectors based on the relationship between the uncorrupted and corrupted regions, we introduce mutual nearest neighbors as reliable anchors and interpolate around these anchors progressively. Finally, based on the corrected mapping vector fields, we propose a two-step warping strategy to complete the corrupted image, utilizing the reference image as a structural “blueprint”, avoiding the style misalignment problem. Extensive experiments show that our approach effectively and robustly assists image inpainting methods in restoring unique structures in the corrupted image.

Clinical and radiological outcomes of posterior cervical decompression and fusion for severe cervical compressive-extension injury: A case series

BackgroundAlthough severe cervical compressive-extension (CE) injuries are usually repaired using a combined anterior-posterior approach, the repair is possible using a posterior approach alone with reliable anchors. This study aimed to present the outcomes and imaging analysis results of posterior cervical decompression and fusion (PCDF) for severe CE injuries. MethodsWe retrospectively reviewed 16 patients who underwent PCDF surgery for severe CE injuries (>50% subluxation) between January 2012 and December 2018. All patients completed 1-year follow-up, and their mean age at the time of surgery was 63.5 years. American Spinal Injury Association Impairment Scale (AIS) grade, kyphotic angle of lower vertebra (KALV), and anterior defect area of lower vertebra (ADLV) were assessed preoperatively. ResultsOf 16 patients, nine patients improved at the final follow-up, and eight patients could walk with or without assistance. All patients achieved bone union postoperatively, but four patients showed progression of correction loss of ≥10°. Therefore, patients were divided into two groups: NL group with correction loss of <10°; L group with correction loss of ≥10°. All patients in L group showed KALV of ≥15°, while 10 of 12 patients in NL group showed KALV of <15°. Furthermore, all patients in L group showed ADLV of ≥50%, whereas all patients in NL group showed ADLV of <50%. ConclusionsPCDF is feasible and a favorable procedure for severe CE injuries that require early reduction and cervical spinal stabilization. However, in the cases of advanced destruction of the anterior vertebra, loss of correction after PCDF might occur postoperatively.

Can the World Monetary System be Saved from Collapse by Monetary Gold

The world community is gripped by the expectation of significant changes in the international monetary system, which has been permanently in crisis for decades. The uncertainty of the future gives rise to a sense of impending catastrophe, which must be prepared now, finding reliable anchors for preserving capital and providing an equivalent exchange in commodity markets. Historically, during a period of aggravation of the crisis of the international monetary system, monetary gold invariably remains as a reliable anchor, which is due not only to its unique properties, but also to the mentality of economic entities of all levels. The article deals with the basis of the emergence and periodic aggravation of the crises of the international monetary system, the causes of the new exacerbation, and the changing role of monetary gold in the process of globalization of the world economy. The role of international reserves in the gold reserve in the maintenance of socio-political stability is shown, the reasons determining the need to preserve and increase the gold reserves of central banks are substantiated.

Accurate Nodes Localization in Anisotropic Wireless Sensor Networks

An accurate localization algorithm tailored for anisotropic wireless sensors networks (WSNs) is proposed in this paper. Using the proposed algorithm, each regular or position-unaware node estimates its distances only to reliable anchors or position-aware nodes. The latter are properly chosen following a new reliable anchor selection strategy that ensures an accurate distance estimation making thereby our localization algorithm more precise. It is shown that the proposed algorithm is implementable in both 2-dimensional (2D) and 3-dimensional (3D) scenarios. A power saving mechanism aiming to enhance the WSN lifetime is also envisaged in this paper. It is proven that the proposed algorithm could easily incorporate such a mechanism. Simulations show that our algorithm, whether combined or not with the power saving mechanism, consistently outperforms the best representative localization algorithms currently available in the literature in terms of accuracy, even with the presence of nonuniform node distribution or radiation irregularities.

RAPS: Reliable Anchor Pair Selection for Range-Free Localization in Anisotropic Networks

This letter presents a range-free localization algorithm with reliable anchor pair selection (RAPS) for anisotropic networks. To mitigate the effects of different network anisotropy, the proposed RAPS algorithm selects reliable anchor pairs by measuring the average hop progresses. The distances to the reliable anchors are estimated based on the geometric approximation of the node location. Compared to existing algorithms, the RAPS algorithm enables higher localization accuracy with fewer anchors while having less communication overhead in anisotropic networks. The superiority of the proposed algorithm is validated over the recently developed algorithms through extensive computer simulations.

Improved Least Median of Squares Localization for Non-Line-of-Sight Mitigation

Non-line-of-sight (NLOS) propagation is one of the major problems that cause errors in localization systems. There exist many algorithms to reduce NLOS caused errors. Most of these algorithms require ap rioriinformation about the NLOS links, which limits their application. The least median of squares (LMedS) method is an exception and is thus attractive for its simplicity. LMedS selects only a subset of the anchors with the smallest residue for location calculation, but it tends to discard more range measurements than necessary. Its performance can be improved significantly, particularly when the percentage of NLOS links is not high. In this paper, we present an improved LMedS method, which maximizes the subset of reliable anchors to be used. We show via simulation that, compared with the existing LMedS method, the proposed algorithm has significantly higher localization accuracy and is more stable. Index Terms—Least median of squares method (LMedS), local- ization, non-line-of-sight (NLOS) propagation.

SPEAR: Source Position Estimation for Anchor Position Uncertainty Reduction

This letter introduces an RSS-based framework (termed Source Position Estimation for Anchor position uncertainty Reduction - SPEAR) for joint estimation of the positions of a wireless transmitter source and the corresponding measuring anchors. The framework exploits the imprecise anchor position information using non-Bayesian estimation and employs a novel Joint Maximum Likelihood (JML) algorithm for reliable anchor and agent position estimations. It proposes to use the iterative Trust Region (TR) strategy as a solution to the JML nonlinear minimization problem. Simulation results show that the JML results in source localization improvements (compared to the ML that ignores the anchor position uncertainty) and provides a more reliable anchors? positions estimates.

Which Granularity to Bootstrap a Multilingual Method of Document Alignment: Character N-grams or Word N-grams?

This article tackle multilingual automatic alignment. Alignment refers to the process by which segments that are translation of one another are automatically matched. Instead of comparing only pairs of languages at sentence level, as it is usually done to conform to human process in translation. The computer is used here for its capacity to infer semantic alignment from a collection of texts that are translations of the same content. The corpus contains press releases from Europa, the European Community website, available in up to 23 languages. The alignment process takes advantage of frequency similarity between different linguistic versions of a document by computing matching features for each repeated string in all versions. This is done to find reliable anchors in the process of linking versions. The question of the best granularity is raised to bring out some semantic equivalences, when comparing two linguistic versions, character N-grams or word N-grams. The alignment systems are traditionally based on word N-grams splitting. The observation of the morphological variety of languages, even inside a single linguistic family, quickly shows that the word granularity is inadequate to provide a widely multilingual system, i.e. a language independent system able to handle flexional languages as well as positional languages. Instead, when starting from a multilingual collection to focus on pairs of texts, we defend that character N-grams alignment is more efficient than word N-grams alignment.

Analysis of select Dalbergia and trade timber using direct analysis in real time and time‐of‐flight mass spectrometry for CITES enforcement

International trade of several Dalbergia wood species is regulated by The Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). In order to supplement morphological identification of these species, a rapid chemical method of analysis was developed. Using Direct Analysis in Real Time (DART) ionization coupled with Time-of-Flight (TOF) Mass Spectrometry (MS), selected Dalbergia and common trade species were analyzed. Each of the 13 wood species was classified using principal component analysis and linear discriminant analysis (LDA). These statistical data clusters served as reliable anchors for species identification of unknowns. Analysis of 20 or more samples from the 13 species studied in this research indicates that the DART-TOFMS results are reproducible. Statistical analysis of the most abundant ions gave good classifications that were useful for identifying unknown wood samples. DART-TOFMS and LDA analysis of 13 species of selected timber samples and the statistical classification allowed for the correct assignment of unknown wood samples. This method is rapid and can be useful when anatomical identification is difficult but needed in order to support CITES enforcement. Published 2012. This article is a US Government work and is in the public domain in the USA.

Reliable Anchor-Based Sensor Localization in Irregular Areas

Localization is a fundamental problem in wireless sensor networks and its accuracy impacts the efficiency of location-aware protocols and applications, such as routing and storage. Most previous localization algorithms assume that sensors are distributed in regular areas without holes or obstacles, which often does not reflect real-world conditions, especially for outdoor deployment of wireless sensor networks. In this paper, we propose a novel scheme called reliable anchor-based localization (RAL), which can greatly reduce the localization error due to the irregular deployment areas. We first provide theoretical analysis of the minimum hop length for uniformly distributed networks and then show its close approximation to empirical results, which can assist in the construction of a reliable minimal hop-length table offline. Using this table, we are able to tell whether a path is severely detoured and compute a more accurate average hop length as the basis for distance estimation. At runtime, the RAL scheme 1) utilizes the reliable minimal hop length from the table as the threshold to differentiate between reliable anchors and unreliable ones, and 2) allows each sensor to determine its position utilizing only distance constraints obtained from reliable anchors. The simulation results show that RAL can effectively filter out unreliable anchors and therefore improve the localization accuracy.

How well do we know VPDB? Variability of δ13C and δ18O in CO2 generated from NBS19‐calcite

In order to generate a local daughter scale from the material defining the international delta13C and delta18O stable isotope ratio scales (NBS19-calcite),1,2 the carbon and oxygen must be liberated to the gas phase, usually as CO2, using acid digestion of the calcite with H3PO4. It is during this conversion step that systematic errors can occur, giving rise to commonly observed discrepancies in isotopic measurements between different stable isotope laboratories. Scale consistency is of particular importance for air-CO2 isotope records where very small differences in isotopic composition have to be reliably compared between different laboratories and quantified over long time periods.3 The information is vital for estimating carbon budgets on regional and global scales and for understanding their variability under the conditions of climate change. Starting from this requirement a number of CO2 preparations from NBS19 were made at Environment Canada (EC) and analyzed in our laboratories together with Narcis II, a set of well-characterized CO2 samples in sealed tubes available from the National Institute for Environmental Studies (NIES).4,5 Narcis II is very homogeneous in delta13C and delta18O with the isotopic composition close to NBS19-CO2. Among our laboratories the results for delta13C agreed to within +/-0.004 per thousand. The same level of agreement in delta13C was obtained when CO2 was generated from NBS19-calcite using different experimental procedures and conditions in the other two laboratories. For delta18O, the corresponding data were +/-0.011 per thousand when using NBS19-CO2 produced at EC, but discrepancies were enhanced by almost one order of magnitude when NBS19-CO2 was prepared by the other laboratories using slightly different reaction conditions (range=0.13 per thousand).In a second series of experiments, larger amounts of CO2 prepared from NBS19 at the Max-Planck-Institut für Biogeochemie (MPI-BGC) were analyzed together with Narcis II and then mixed into CO2-free air. The resulting artificial air samples then were measured by the same three laboratories for the stable isotopic composition of CO2 using locally established extraction and evaluation procedures. Comparison of the results with the prior CO2 values and between the laboratories revealed additional systematic differences owing to the local CO2 extraction processes and standardization procedures. For delta13C the results showed a narrow range of discrepancies of about 0.02 per thousand; for delta18O cumulative disagreements in the range of 0.1 per thousand were observed. From these results the following conclusions are inferred: NBS19-CO2 is a reliable primary anchor to the VPDB delta13C scale. Although prepared by different methods an accuracy of better than +/-0.003 per thousand has been reached. This applies to sample amounts of 5 mg calcite or more.NBS19-CO2 can be used as a general anchor to the VPDB delta18O scale only for accuracy requirements of +/-0.1 per thousand. For a higher scale resolution additional agreements regarding details of the acid digestion reaction will have to be worked out and agreed upon.Narcis II-CO2 comprises an ideal set of test samples for the VPDB scale. The delta13C value is +1.923+/-0.003 per thousand (combined uncertainty); delta18O is between -2.50 and -2.65 per thousand versus VPDB-CO2, with most of the variation in this figure depending on details of the NBS19-CO2 preparation used for the calibration. (Ampoule to ampoule homogeneity is better than 0.01 per thousand.)When mixing NBS19-CO2 into artificial air and using this to test performance between laboratories, the delta13C offsets are small with a remaining discrepancy of only 0.02 per thousand. For delta18O, systematic disagreements are considerably larger than those found for the pure CO2 comparison. Further experimental clarification is required.Artificial air samples such as NBS19-CO2 in air can be used as reliable anchors to create a unified stable isotope scale between different laboratories. An adjustment of local scales based on these air standards appears to be necessary for improving data comparability.

An embedded anchor with an improved response to repeated loading

As ocean operations have expanded and moved into deeper waters the need for development of high capacity, reliable anchors for long term moorings has emerged. The advantages of embedded anchors are demonstrated but the ‘cyclic creep’ phenomenon is highlighted as potentially damaging to their long term behaviour. A small scale device to prevent cyclic creep is described (AECC system) and the behaviour of an anchor incorporating this device compared to a conventional embedded anchor. Response to both static and repeated loading is presented and the deleterious effect of repeated loading on the life of the system, particularly when installed by soil disturbing procedures, emphasized. It is shown that the use of the AECC device will provide considerable improvements in anchor life. In addition, it is clear that the use of static loading test results in order to demonstrate the general suitability of an embedded anchor is misleading and bears little relationship to subsequent long term response. Finally, proposals are made regarding the incorporation of the AECC device into existing large scale anchors and it is considered that this will result in substantial improvements in behaviour.