Common Paths Research Articles

Double-difference seismic attenuation tomography method and its application to The Geysers geothermal field, California

SUMMARY Knowledge of attenuation structure is important for understanding subsurface material properties. We have developed a double-difference seismic attenuation (DDQ) tomography method for high-resolution imaging of 3-D attenuation structure. Our method includes two main elements, the inversion of event-pair differential ${t^*}$ ($d{t^*}$) data and 3-D attenuation tomography with the $d{t^*}$ data. We developed a new spectral ratio method that jointly inverts spectral ratio data from pairs of events observed at a common set of stations to determine the $d{t^*}$ data. The spectral ratio method cancels out instrument and site response terms, resulting in more accurate $d{t^*}$ data compared to absolute ${t^*}$ from traditional methods using individual spectra. Synthetic tests show that the inversion of $d{t^*}$ data using our spectral ratio method is robust to the choice of source model and a moderate degree of noise. We modified an existing velocity tomography code so that it can invert $d{t^*}$ data for 3-D attenuation structure. We applied the new method to The Geyser geothermal field, California, which has vapour-dominated reservoirs and a long history of water injection. A new Qp model at The Geysers is determined using P-wave data of earthquakes in 2011, using our updated earthquake locations and Vp model. By taking advantage of more accurate $d{t^*}$ data and the cancellation of model uncertainties along the common paths outside of the source region, the DDQ tomography method achieves higher resolution, especially in the earthquake source regions, compared to the standard tomography method using ${t^*}$ data. This is validated by both the real and synthetic data tests. Our Qp and Vp models show consistent variations in a normal temperature reservoir that can be explained by variations in fracturing, permeability and fluid saturation and/or steam pressure. A prominent low-Qp and Vp zone associated with very active seismicity is imaged within a high temperature reservoir at depths below 2 km. This anomalous zone is likely partially saturated with injected fluids.

Social housing: common needs, common paths, and common barriers. The Uruguayan experience

This paper attempts to describe a particularly successful model of social production of habitat, that of Uruguayan housing cooperatives, which has already been developed for more than half a century, linking it with the conclusions of studies on the management of common goods by the people own selves by the Elinor Ostrom. Uruguayan housing cooperative´s characteristics and central aspects are analysed. Main singularities of the system are self-management, direct involvement of future users throughout their work or savings, and collective ownership of the houses, granting the right to use and enjoy to households. Subsequently, it is made a brief presentation of Ostrom’s work on commons and the Uruguayan cooperative model is taken up considering these concepts. This paper concludes that this social housing model would have great potential if had the support of the governments, currently oriented to free market, throughout development of an adequate legal framework, public funding, and access to land.

Hidden Fissures and Epidemics in Plain Sight: The Common Paths of Syphilis and HIV in Russia

The paper examines and compares two epidemics in Russia: syphilis in the first quarter of 20th century and HIV in the early 21st century. The author considers both epidemics from the standpoint of the social sciences by applying the concept of vulnerability to underline the social and cultural factors that cause one social group to be more susceptible to a disease than another. The article focuses on gender-based vulnerability and maintains that both epidemics follow a single, structurally similar scenario. The author shows that the vulnerability of women during both the syphilis and HIV epidemics depends upon the clear continuity in the way gender roles and expectations and the relationships between men and women were structured during the early days of the USSR and in present-day Russia. The article analyzes how stigma arises and how in both eras inequality of power and expectations for men and women formed the main channel for transmission of disease. The paths along which modern epidemics spread have been mostly inherited from the epidemics of past centuries, and in particular the HIV epidemic is following a pattern derived from the syphilis epidemic. More precisely, the current epidemics exploit the same vulnerability of certain groups, vulnerability rooted in the past and still manifest in the norms and relations in contemporary culture and society where one group is much more exposed than the other. The article relies on historical sources, in particular Lev Friedland"s book Behind a Closed Door: Observations of a Venereologist published in 1927, for its account of the syphilis epidemic in the early 20th century and on the author"s own research into the experience of women living with HIV in contemporary Russia.

Tracking embodied water uses and GHG emissions along Chinese supply chains

China is facing both serious water scarcity and climate change challenges simultaneously. There is an urgent need to identify the synergies between water conservation and greenhouse gas (GHG) emission mitigation. This paper aims to trace the embodied water uses and GHG emissions (i.e., CO2, CH4 and N2O) via China's domestic supply chains in 2012 and to explore their common important paths for driving the water withdrawals and the emissions of GHGs using the environmentally-extended input-output analysis and the structural path analysis. The results show a significant coupling between the embodied water uses and the embodied emissions of CO2, CH4 and N2O in the supply chains on a national scale. The water-GHG nexus relationships from the consumption-side are systematically revealed in terms of industrial sectors, final demands and supply chain paths. The top 20 nexus paths ranked by water together accounted for 37.40% of the national total water withdrawals. Ranked by GHGs, the proportions were 22.46% of the total GHG emissions. Synergies in saving water resources and mitigating the emissions of CO2, CH4 and N2O can be achieved through controlling important supply chain paths and critical transmission sectors. The highly interlinked nature of water and climate change issues requires comprehensive solutions to reduce future freshwater and GHG emission needs to maintain sustained economic growth in China.

EMI Noise Reduction for the Single-Phase Grid-Connected Inverter With A Modified Harmonic Filter Design

Harmonics and conducted electromagnetic interference (EMI) are two main issues in grid-connected inverter system. In this article, a modified LCL-LC harmonic filter is structured to strengthen its EMI suppression ability. Considering the common mode and differential mode EMI propagation paths, the traditional LCL-LC filter is split into a symmetrical topology, and with the midpoint of the split filtering capacitors connected to the midpoint of the dc-link capacitor. Compared to the traditional LCL-LC filter, the modified one can maintain the satisfied harmonic attenuation ability and strengthen the EMI suppression. Also, a double closed-loop control strategy is employed to solve the severe resonance problem caused by the harmonic filter. Moreover, a system calibration method is proposed and introduced to design the controller parameters to improve the high-order grid-connected system's stability. A comprehensive analysis and discussions concerning the traditional and modified LCL-LC filters are conducted in simulation and experiment on a 2 kW/220 V/50 Hz single-phase grid-connected inverter. The results have verified the feasibility of the proposed design method, and shown the superiority of the modified LCL-LC filter and active damping strategy in EMI mitigation. Besides, the weight and volume of the harmonic filter can be significantly reduced through this strategy.

Early prediction of macrocrack location in concrete, rocks and other granular composite materials

Heterogeneous quasibrittle composites like concrete, ceramics and rocks comprise grains held together by bonds. The question on whether or not the path of the crack that leads to failure can be predicted from known microstructural features, viz. bond connectivity, size, fracture surface energy and strength, remains open. Many fracture criteria exist. The most widely used are based on a postulated stress and/or energy extremal. Since force and energy share common transmission paths, their flow bottleneck may be the precursory failure mechanism to reconcile these optimality criteria in one unified framework. We explore this in the framework of network flow theory, using microstructural data from 3D discrete element models of concrete under uniaxial tension. We find the force and energy bottlenecks emerge in the same path and provide an early and accurate prediction of the ultimate macrocrack path {mathcal {C}}. Relative to all feasible crack paths, the Griffith’s fracture surface energy and the Francfort–Marigo energy functional are minimum in {mathcal {C}}; likewise for the critical strain energy density if bonds are uniformly sized. Redundancies in transmission paths govern prefailure dynamics, and predispose {mathcal {C}} to cascading failure during which the concomitant energy release rate and normal (Rankine) stress become maximum along {mathcal {C}}.

Phase-stable optical activity measurement by common-path spectral interferometry.

A robust optical activity (OA) spectrometer covering the visible and near-infrared regimes was designed and built via a combination of a linear polarizer and a birefringent plate. The OA spectrometer relies on common-path spectral interferometry, where the two interfering fields travel common optical paths, and ensures signal reproducibility over several hours. By detecting OA without polarization switching, the data acquisition time is shortened to 1 s, enabling real-time monitoring of the chiral complex formation. The present configuration also allows OA measurement with broadband pulses, which is promising for probing ultrafast circular dichroism and optical rotatory dispersion.

Unmasking Arrhythmogenic Hubs of Reentry Driving Persistent Atrial Fibrillation for Patient-Specific Treatment.

BackgroundAtrial fibrillation (AF) driver mechanisms are obscured to clinical multielectrode mapping approaches that provide partial, surface‐only visualization of unstable 3‐dimensional atrial conduction. We hypothesized that transient modulation of refractoriness by pharmacologic challenge during multielectrode mapping improves visualization of hidden paths of reentrant AF drivers for targeted ablation.Methods and ResultsPharmacologic challenge with adenosine was tested in ex vivo human hearts with a history of AF and cardiac diseases by multielectrode and high‐resolution subsurface near‐infrared optical mapping, integrated with 3‐dimensional structural imaging and heart‐specific computational simulations. Adenosine challenge was also studied on acutely terminated AF drivers in 10 patients with persistent AF. Ex vivo, adenosine stabilized reentrant driver paths within arrhythmogenic fibrotic hubs and improved visualization of reentrant paths, previously seen as focal or unstable breakthrough activation pattern, for targeted AF ablation. Computational simulations suggested that shortening of atrial refractoriness by adenosine may (1) improve driver stability by annihilating spatially unstable functional blocks and tightening reentrant circuits around fibrotic substrates, thus unmasking the common reentrant path; and (2) destabilize already stable reentrant drivers along fibrotic substrates by accelerating competing fibrillatory wavelets or secondary drivers. In patients with persistent AF, adenosine challenge unmasked hidden common reentry paths (9/15 AF drivers, 41±26% to 68±25% visualization), but worsened visualization of previously visible reentry paths (6/15, 74±14% to 34±12%). AF driver ablation led to acute termination of AF.ConclusionsOur ex vivo to in vivo human translational study suggests that transiently altering atrial refractoriness can stabilize reentrant paths and unmask arrhythmogenic hubs to guide targeted AF driver ablation treatment.

“Nudge” in Lucca’s Hospital: separate waste collection improvement and cigarettes dumping reduction

Abstract Background Positive behaviour and user's collaboration improved by using choices orientation techniques; in Lucca's Hospital (North-West Tuscany Sanitary Authority) this approach has improved separate waste collection execution and has decreased cigarettes dumping in commons areas. Objectives Phase 1 (May 2019): amendment of choices architecture recyclable waste bins in commons areas and into the wards were boosted, with “islands” clearly visible from any point of common paths; in the transit areas were installed exclusively multi-material and paper bins, equipped with signs that clearly indicate which products deliver; residual waste bins were allowed exclusively in certain points.ashtrays at the hospital entrances were eliminated and replaced with signage indicating smoking cessation benefits and the presence of areas “put your cigarette out” along the structure approach routes. Phase 2 (scheduled for May 2020): “nudge” action Spreading in community (using press and social-media) and locally (using poster) of the slogan “In San Luca we are taking a step forward: don't lag behind!”. This message stimulate the perception of an ongoing change to join. Results A decrease in residual waste collection and in instances of non-compliance in separate waste collection was detected. Decorum in the outdoor environments improved, with a reduction of user's reports and extra-cleaning interventions. Conclusions The described actions have improved user's collaboration, management efficiency of waste disposal and cleaning service, perceived quality and cost. Key messages Imitating a social model appears to be successful motivator of virtuous behaviours. Choices architecture and “nudge” techniques may improve citizens’ care pathways governance.

Development Grouping of Synonym Set Thesaurus Vocabulary The Qur’an in English Using Hierarchical Clustering Algorithm

Research in the field of text mining to process entries or words from the Qur'an is very beneficial for Muslims. This study aims to establish a set of synonyms for the thesaurus in the words of the Qur'an. This research is used because the source of knowledge about the science of the Qur'an is still lacking. The dataset in this study uses the Corpus Qur'an and English Translation. This research is a research development of an article that has been published, namely "The Development of Al-Qur'an Vocabulary Set Synonyms with WordNet Approach" by Laras Gupitasari. Input from this research system uses nouns from the translation of English words in the Quran. The output of the system produces several groups that have the same level of closeness of meaning displayed, the first group means the word in the group has a close meaning. To produce output, this study uses word grouping with a hierarchical grouping method and calculates distances using common paths, then groups results according to the closeness of meaning from word entries. The evaluation in this study produced an F-Measure value of 76%, F-Measure Value is an evaluation to measure the accuracy of predictions issued by the system.

How the manufacturing economy impacts China's energy-related GHG emissions: Insights from structural path analysis

As “the world's factory”, China's energy consumption and GHG emissions can be largely attributed to its manufacturing economy. This paper aims to examine energy-related methane (CH4) and carbon dioxide (CO2) emissions by Chinese economy from a consumption-based perspective, and to explore the energy-climate-manufacturing nexus relationship in its supply chains. Nearly three-quarters of China's energy-related GHG emissions in 2012 were associated with the manufacturing industry directly or indirectly. Among which, over two-fifths of the national CH4 and CO2 emissions were embodied in the final demand of manufacturing products, mainly driven by the exports and capital formation. Meanwhile, manufacturing sectors served as important intemediate transmission nodes of embodied emissions for other industries such as construction and services. More than 80% and 40% of the embodied emissions in the sectors of construction and services were related to the intermediate uses of manufacturing products, respectively. Critical supply chain paths for linking embodied GHG emissions with manufacturing sectors were extracted through the structural path analysis technique. The top 30 common paths were responsible for about one fifth of the total CH4 and CO2 emissions. Three main transmission nodes of embodied energy-related GHG emission flows were identified. While approximately half of the energy-related CH4 emissions occurred at the fourth or higher production layers, the CO2 emissions were distributed evenly across the production layers. Mitigating energy-related GHG emissions associated with manufacturing economy by adjusting critical industrial sectors and final demands provides new insights for understanding the transitions of China's manufacturing industries to a low-carbon economy.

Beaver and Naked Mole Rat Genomes Reveal Common Paths to Longevity

Long-lived rodents have become an attractive model for the studies on aging. To understand evolutionary paths to long life, we prepare chromosome-level genome assemblies of the two longest-lived rodents, Canadian beaver (Castor canadensis) and naked mole rat (NMR, Heterocephalus glaber), which were scaffolded with invitro proximity ligation and chromosome conformation capture data and complemented with long-read sequencing. Our comparative genomic analyses reveal that amino acid substitutions at "disease-causing" sites are widespread in the rodent genomes and that identical substitutions in long-lived rodents are associated with common adaptive phenotypes, e.g., enhanced resistance to DNA damage and cellular stress. By employing a newly developed substitution model and likelihood ratio test, we find that energy and fatty acid metabolism pathways are enriched for signals of positive selection in both long-lived rodents. Thus, the high-quality genome resource of long-lived rodents can assist in the discovery of genetic factors that control longevity and adaptive evolution.

On Virtual Network Embedding: Paths and Cycles

Network virtualization provides a promising solution to overcome the ossification of current networks, allowing multiple Virtual Network Requests (VNRs) to be embedded on a common infrastructure. The major challenge in network virtualization is the Virtual Network Embedding (VNE) problem, which is to embed VNRs onto a shared substrate network and known to be $\mathcal {NP}$ -hard. The topological heterogeneity of VNRs is one important factor hampering the performance of the VNE. However, in many specialized applications and infrastructures, VNRs are of some common structural features, e.g., paths and cycles. To achieve better outcomes, it is thus critical to design dedicated algorithms for these applications and infrastructures by taking into accounting topological characteristics. Besides, paths and cycles are two of the most fundamental topologies that all network structures consist of. Exploiting the characteristics of path and cycle embeddings is vital to tackle the general VNE problem. In this paper, we investigate the path and cycle embedding problems. For path embedding, we prove its $\mathcal {NP}$ -hardness and inapproximability. Then, by utilizing Multiple Knapsack Problem (MKP) and Multi-Dimensional Knapsack Problem (MDKP), we propose an efficient and effective MKP-MDKP-based algorithm. For cycle embedding, we propose a Weighted Directed Auxiliary Graph (WDAG) to develop a polynomial-time algorithm to determine the least-resource-consuming embedding. Numerical results show our customized algorithms can boost the acceptance ratio and revenue compared to generic embedding algorithms in the literature.

Shared Causal Paths underlying Alzheimer\u2019s dementia and Type 2 Diabetes

Although Alzheimer’s disease (AD) is a central nervous system disease and type 2 diabetes MELLITUS (T2DM) is a metabolic disorder, an increasing number of genetic epidemiological studies show clear link between AD and T2DM. The current approach to uncovering the shared pathways between AD and T2DM involves association analysis; however such analyses lack power to discover the mechanisms of the diseases. As an alternative, we developed novel causal inference methods for genetic studies of AD and T2DM and pipelines for systematic multi-omic casual analysis to infer multilevel omics causal networks for the discovery of common paths from genetic variants to AD and T2DM. The proposed pipelines were applied to 448 individuals from the ROSMAP Project. We identified 13 shared causal genes, 16 shared causal pathways between AD and T2DM, and 754 gene expression and 101 gene methylation nodes that were connected to both AD and T2DM in multi-omics causal networks.

Identifying common paths of CO2 and air pollutants emissions in China

China faces the dual challenge of mitigating climate change and preventing air pollution. The coordinated control of both problems has become an issue of widespread concern. This study combined environmentally extended input-output analysis and structural path analysis to analyze the CO2, SO2, NOx, black carbon, and PM2.5 emissions embodied in the production supply chain of China in 2012. The results showed that electricity and heat production, nonmetallic mineral products along with the smelting and pressing of metal were primary sources of environmental emissions from the production perspective, and construction contributed 20–38% relevant emissions from the consumption perspective. Among the 100 largest paths, 22 common critical paths accounted for 16–37% of relevant emissions, meaning that measures focusing on these shared paths will have obvious co-controlling effects. These 22 critical supply chains were mainly driven by fixed capital formation and exports. The dominant sectors included the construction, electricity and heat production, transportation and storage, and construction-materials production (nonmetallic mineral products, smelting and pressing of metal). Therefore, measures from the production-side and the consumption-side should be given equal attention to effectively co-control such emissions. Measures to decrease energy intensity, thus reducing end-of-pipe discharge in these sectors, rather than to remove specific pollutants, represent the most promising production-related measures. Moreover, slowing construction growth by guiding investments and encouraging the use or export of products with lower emissions using environmental information labels are essential consumption-related policies.

Cyber-Attacks on the Oil & Gas Sector: A Survey on Incident Assessment and Attack Patterns

During the past two decades, oil and gas operational and information technology systems have experienced constant digital growth, closely followed by an increasing number of cyber-attacks on the newly interconnected systems. Adversaries exploit vulnerable accessible device or malware attacks networked services, in an attempt to gain access to critical systems and machinery that are interconnected over networks. Given the importance of the oil and gas sector on the global economy and the diversity of critical systems often being controlled over remote locations, it is highly important to understand and mitigate such attacks. In this paper, we survey cyber-attacks on all three domains of the oil and gas sector (upstream, midstream, downstream) starting from the early 90s up until 2020. For each domain, we document and analyze verified attacks based on real-world reports and published demo attacks on systems. We map and catalogue the attack types used in each case, in order to understand common and subliminal attack paths against oil and gas critical operations. Our aim is threefold, i.e., first, to assess documented attacks using standardized impact assessment techniques and highlight potential consequences of cyber-attacks on this sector, second, to build a vulnerability taxonomy based on technical knowledge gathered by all such incidents and connect each vulnerability with oil and gas systems and respective attack paths, and third, to map the documented knowledge and taxonomies with MITRE’s international knowledge base of Adversary Tactics and Techniques, so as to provide a general guide for analyzing and protecting against cyber-attacks at oil and gas infrastructures.

Relative-path-based algorithm for link prediction on complex networks using a basic similarity factor

Complex networks have found many applications in various fields. An important problem in theories of complex networks is to find factors that aid link prediction, which is needed for network reconstruction and to study network evolution mechanisms. Though current similarity-based algorithms study factors of common neighbors and local paths connecting a target node pair, they ignore factor information on paths between a node and its neighbors. Therefore, this paper first supposes that paths between nodes and neighbors provide basic similarity features. Accordingly, we propose a so-called relative-path-based method. This method utilizes factor information on paths between nodes and neighbors, besides paths between node pairs, in similarity calculation for link prediction. Furthermore, we solve the problem of determining the parameters in our algorithm as well as in other algorithms after a series of discoveries and validations. Experimental results on six disparate real networks demonstrate that the relative-path-based method can obtain greater prediction accuracy than other methods, as well as performance robustness.

Analysis Tools for the VyPR Performance Analysis Framework for Python

VyPR (http://pyvypr.github.io/home/) is a framework being developed with the aim of automating as much as possible the performance analysis of Python programs. To achieve this, it uses an analysis-by-specification approach; developers specify the performance requirements of their programs (without any modifications of the source code) and such requirements are checked at runtime. VyPR then provides tools which allow developers to perform detailed analyses of the performance of their code. Such analyses can include determining the common paths taken to reach badly performing parts of code, deciding whether a single path through code led to variations in time taken by future observations, and more. This paper describes the developments that have taken place in the past year on VyPR’s analysis tools to yield a Python shell-based analysis library, and a web-based application. It concludes by demonstrating the use of the analysis tools on the CMS Experiment’s Conditions Upload service.

Utilization of the cyclic interferometer in polarization phase-shifting technique to determine the thickness of transparent thin-films

An alternative polarization phase-shifting technique is proposed to determine the thickness of transparent thin-films. In this study, the cyclic interferometric configuration is chosen to maintain the stability of the operation against external vibrations. The incident light is simply split by a non-polarizing beam splitter cube to generate test and reference beams, which are subsequently polarized by a polarizing beam splitter. Both linearly polarized beams are orthogonal and counter-propagating within the interferometer. A wave plate is inserted into the common paths to introduce an intrinsic phase difference between the orthogonal polarized beams. A transparent thin-film sample, placed in one of the beam tracks, modifies the output signal in terms of the phase retardation in comparison with the reference beam. The proposed phase-shifting technique uses a moving mirror with a set of “fixed” polarizing elements, namely, a quarter-wave retarder and a polarizer, to facilitate phase extraction without rotating any polarizing devices. The measured thicknesses are compared with the measurements of the same films acquired using standard equipment such as the field-emission scanning electron microscope and spectroscopic ellipsometer. Experimental results with the corresponding measured values are in good agreement with commercial measurements. The system can be reliably utilized for non-destructive thickness measurements of transparent thin-films.

De casa para o meio-fio: pequenas histórias de uma residência terapêutica

Estes escritos versam sobre figuras do cotidiano de ex-internos de um hospital psiquiátrico em uma residência terapêutica na cidade de Vitória-ES. Após anos de isolamento manicomial, seus moradores e parceiros criam caminhos comuns de uma vida em liberdade, abrindo-se à imprevisibilidade das relações sociais, temporais, afetivas etc., que se dão no espaço comunitário, bem como às lutas e resistências diante dos mecanismos biopolíticos de normalização. Foram utilizados registros em caderno de campo como ferramenta metodológica, inspirando a produção de pequenas narrativas, fragmentos de histórias, que compõem e ativam o fluxo de experiências associadas à reforma psiquiátrica e à luta antimanicomial, com o objetivo de contribuir para uma manutenção das conquistas desse campo e também para o avanço desses processos. Os resultados apontam para a produção de um cuidado em saúde mental indissociável de uma dimensão ético-estético-política, afirmando práticas de potencialização de liberdades, buscando afetações e trocas com outras formas de sociabilidade.