Horizontal Connections Research Articles

Modular horizontal network within mouse primary visual cortex.

Interactions between feedback connections from higher cortical areas and local horizontal connections within primary visual cortex (V1) were shown to play a role in contextual processing in different behavioral states. Layer 1 (L1) is an important part of the underlying network. This cell-sparse layer is a target of feedback and local inputs, and nexus for contacts onto apical dendrites of projection neurons in the layers below. Importantly, L1 is a site for coupling inputs from the outside world with internal information. To determine whether all of these circuit elements overlap in L1, we labeled the horizontal network within mouse V1 with anterograde and retrograde viral tracers. We found two types of local horizontal connections: short ones that were tangentially limited to the representation of the point image, and long ones which reached beyond the receptive field center, deep into its surround. The long connections were patchy and terminated preferentially in M2 muscarinic acetylcholine receptor-negative (M2-) interpatches. Anterogradely labeled inputs overlapped in M2-interpatches with apical dendrites of retrogradely labeled L2/3 and L5 cells, forming module-selective loops between topographically distant locations. Previous work showed that L1 of M2-interpatches receive inputs from the lateral posterior thalamic nucleus (LP) and from a feedback network from areas of the medial dorsal stream, including the secondary motor cortex. Together, these findings suggest that interactions in M2-interpatches play a role in processing visual inputs produced by object-and self-motion.

Crisis resilience assessment and management of public utility companies

Currently, the most frequently used models for forecasting the probability of company bankruptcy in the housing and utilities sector lack accuracy. The hypothesis is put forward that crisis resilience of a company can be assessed based on its adaptive capabilities. The paper aims to construct a more accurate compared to the known regression model for predicting bankruptcies, as well as develop models for assessing the quality of crisis adaptation management at public utility companies allowing for the stakeholders’ interests and peculiarities of their interface. The methodological basis of the study consists of the theory of crisis management and a stakeholder approach. The methods include multiple regression analysis, stakeholder mapping, sociological survey, and expert assessments. The evidence comes from the accounting and statistical reporting of 49 public utility companies, materials of arbitration cases, survey results of 33 heads of organisations obtained in the period from February to March 2023. The theoretical developments are implemented within the empirical studies of public utility companies. To improve crisis adaptation and resilience of public utility companies the findings recommend to launch staff training programmes, establish mechanisms for horizontal intra-sectoral connections and maintain cooperation at the level of public authorities in order to control investments in the housing and utilities sector.

Hydrocarbon micro‐migration and differential enrichment mechanism of shale oil in upper Cretaceous Qingshankou Formation in Songliao Basin

Shale reservoir has strong heterogeneity in mineral composition and oil content even at a short distance in the same interval. To better understand the accumulation mechanism of shale oil and hydrocarbon migration tendency in the interval, and explore the main influencing factors of distribution. This paper employed various methods, including thin‐section observation, TOC (total organic matter (OM)) analysis, rock pyrolysis, Soxhlet extraction, group component separation, and GC–MS (gas chromatography mass spectrometry) analysis of saturated hydrocarbons. The shale oil samples were collected from an exploratory well in the Songliao Basin, and the distribution and enrichment characteristics of shale oil interlayers were analysed. The results show that the first member of Qingshankou Formation (K2qn1) could be divided into six small layers. From Q1 to Q6, the lithofacies could be divided into three types: high‐frequency laminar shale, massive shale, and bioclastic shale. The lacustrine matrix shale of K2qn1 in Songliao Basin has medium TOC, and high oil contents, OM conversion rate. The TOC ranges from 1.5 to 4.2 wt%, S1 varies between 1.4 and 4 mg/g, S2 falls within the range of 4 to 10.6 mg/g, Tmax ranges from 351 to 497°C, and the OSI varies between 57 and 115.34 mg HC/g rock. The lower part of the K2qn1, Q1–Q4, characterized by high‐frequency laminar shale, contained residual shale oil, while the upper part of the K2qn1, Q5 and Q6, characterized by bioclastic shale and massive mudstone, and are dominated by in‐situ type shale oil. The crude oil in K2qn1 is homologous, and primarily undergoes micro‐migration. The Q5–Q6 section has the highest light oil content, while other regions with notable light components are located in the middle of Q1, the upper sections of Q2, Q3, and Q4.Q1–Q4 are primarily composed of residual shale oil, whereas Q5–Q6 is primarily composed of in‐situ shale oil, and the primary micro‐migration direction of shale oil occurs laterally within Q1–Q4. The lateral migration of each section mainly occurs at the upper part of Q3 and Q4, the lower part of Q1 and Q2, the bottom of Q5, and the interface between Q6 and the second member of Qingshankou formation (K2qn2). The block mudstone retains in‐situ shale oil, especially light hydrocarbons. Within the high‐frequency laminar shale, there is strong horizontal connectivity, and lateral hydrocarbon expulsion serves as the primary mechanism for micro‐migration in Q1–Q4. This paper can provide reference values for K2qn1 Formation shale oil and the migration and differential reservoir formation of medium and high‐maturity matrix shale oil.

Spike synchrony as a measure of Gestalt structure

The function of spike synchrony is debatable: some researchers view it as a mechanism for binding perceptual features, others – as a byproduct of brain activity. We argue for an alternative computational role: synchrony can estimate the prior probability of incoming stimuli. In V1, this can be achieved by comparing input with previously acquired visual experience, which is encoded in plastic horizontal intracortical connections. V1 connectivity structure can encode the acquired visual experience in the form of its aggregate statistics. Since the aggregate statistics of natural images tend to follow the Gestalt principles, we can assume that V1 is more often exposed to Gestalt-like stimuli, and this is manifested in its connectivity structure. At the same time, the connectivity structure has an impact on spike synchrony in V1. We used a spiking model with V1-like connectivity to demonstrate that spike synchrony reflects the Gestalt structure of the stimulus. We conducted simulation experiments with three Gestalt laws: proximity, similarity, and continuity, and found substantial differences in firing synchrony for stimuli with varying degrees of Gestalt-likeness. This allows us to conclude that spike synchrony indeed reflects the Gestalt structure of the stimulus, which can be interpreted as a mechanism for prior probability estimation.

Motivation components of personnel management at enterprises

Methods. Methods of analysis and synthesis, empirical methods, methods of induction and deduction, graphic and logical methods, methods of financial, economic and statistical analysis were used in the process of researching the components of personnel management of enterprises. The methodological basis of the research is the index method, the results of which allow evaluating the main components of the enterprise personnel management. Results. The article provides a detailed analysis of statistical data and survey results regarding the main motivational components of personnel management at enterprises. The dependence between indicators of economic activity and components of personnel motivation was revealed. The article substantiates the main motivational components of personnel management, improves the structuralfunctional model of the dependence of quantitative and qualitative indicators and the motivational component of personnel management of the enterprise, which synthesizes a comprehensive approach to taking into account all important directions of improvement of motivational processes of personnel management. Novelty. It consists in justifying the need to take into account motivational components when planning and improving the scientific and methodological foundations of the development of a structural and functional model of personnel management and a system for evaluating the economic activity of the enterprise. Practical value. Evaluation of the motivational components of the personnel management of the enterprise is the basis for building effective models of the development of enterprises, which is an analytical tool for organizing the vertical and horizontal connections of the management system of the multi-level and multifunctional management decision-making system, taking into account the properties of the interdependent influence of performance indicators and establishing the safety parameters of individual trajectories of the development of personnel management .

Dispersal constrains the biotic connectivity of mountain assemblages

AbstractAimClimate warming is shifting the bioclimatic optima of species towards mountaintops, but the ability of organisms to track these changes also depends on their dispersal skills. Here, we assessed the role of dispersal over niche‐driven processes in connecting assemblages along mountain slopes and between mountain massifs.LocationCantabrian Mountains, Spain.TaxonBirds (Animalia; Aves) and Lichens (Fungi; Ascomycota, Basidiomycota).MethodsWe examined the change with elevation of community‐level traits that are dispersal proxies (wing shape in birds and type of dispersing propagule in lichens) and ecological niche proxies (micro‐habitat, substrate, and foraging features). We then permutate species composition within sites and massifs to create models of species distribution constrained by dispersal and niche processes. These models were compared with observed species distribution to disclose the relative contribution of dispersal and niche‐based processes in the biotic interchange along mountain slopes (vertical connectivity) and between isolated summits (horizontal connectivity).ResultsBoth bird and lichen communities were formed by species with traits that enhance dispersal at high elevations. These groups also showed similarities in the elevational patterns of niche diversity, which dropped at high elevations. Dispersal was by far the dominant assembly mechanism in both taxa. Pairwise community comparisons among elevation belts showed weak vertical connectivity, with predominant dispersal limitations but also niche barriers between the extremes of the gradient. Among massifs, horizontal connectivity was higher among high mountain assemblages than those from lower elevations.Main ConclusionDispersal was found to be the dominant assembly mechanism in mountain systems, even in taxa with high dispersal potential. Highland assemblages had low functional diversity but their species had high mobility. This permits biotic interchange between isolated summits and, potentially, colonization of other summits as climate warms. Our framework combining traits and occurrence‐permutation models improve the understanding of community assembly mechanisms along elevation gradients and points to dispersal limitations, especially at low‐middle elevations.

Perceptual Cycles Travel Across Retinotopic Space.

Visual perception waxes and wanes periodically over time at low frequencies (theta: 4-7 Hz; alpha: 8-13 Hz), creating "perceptual cycles." These perceptual cycles can be induced when stimulating the brain with a flickering visual stimulus at the theta or alpha frequency. Here, we took advantage of the well-known organization of the visual system into retinotopic maps (topographic correspondence between visual and cortical spaces) to assess the spatial organization of induced perceptual cycles. Specifically, we tested the hypothesis that they can propagate across the retinotopic space. A disk oscillating in luminance (inducer) at 4, 6, 8, or 10 Hz was presented in the periphery of the visual field to induce perceptual cycles at specific frequencies. EEG recordings verified that the brain responded at the corresponding inducer frequencies and their first harmonics. Perceptual cycles were assessed with a concurrent detection task-target stimuli were displayed at threshold contrast (50% detection) at random times during the inducer. Behavioral results confirmed that perceptual performance was modulated periodically by the inducer at each frequency. We additionally manipulated the distance between the target and the inducer (three possible positions) and showed that the optimal phase, that is, moment of highest target detection, shifted across target distance to the inducer, specifically when its flicker frequency was in the alpha range (8 and 10 Hz). These results demonstrate that induced alpha perceptual cycles travel across the retinotopic space in humans at a propagation speed of 0.3-0.5 m/sec, consistent with the speed of unmyelinated horizontal connections in the visual cortex.

Новая индустриализация – в основе синергия науки, инноваций и пространственных особенностей

The paper analyzes the problems of the new industrialization of the Russian economy in the context of the peculiarities of its historical development, as well as the colossal role and importance that the spatial factor has in our country. We have shown the importance of solving the problem of the formation and development of horizontal connections and interactions - both at the level of industries and organizations, and territories. The solution to this problem is largely delayed. This is due to historical reasons. The reasons are the departmental (corporate) model of vertical organization of industrial structures that has developed and continues to this day and insufficient involvement in the processes of industrialization of territories. According to the authors, the development of cooperative ties and integration processes in modern conditions is impossible without solving the deferred problem noted above.

Сучасні тенденції розвитку комунікаційної діяльності як інструменту публічного адміністрування

The article analyzes the communication paradigm of relations between government and society. The main functions of state communication are analyzed. Different stages of the communicative process are considered. Modern approaches in the field of management of political and communicative processes in government bodies are highlighted. Attention is drawn to the complication of the social structure and connections, the increase of non-state participants in the political process, the formation of the infrastructure of the information society, and the growing role of horizontal connections, which require new approaches in managing political processes. The focus of the scientific article is on new communication practices and the possibilities of their use in political activity, among which strategic management technologies and PR activities, crowdsourcing technology, Internet technologies, and network communities stand out. On the one hand, new information technologies can significantly transform the modern communication practices of authorities, contributing to the establishment of rigid forms of power based on subordination and subject-object relations. On the other hand, information can be used to form a new image of power, which received the concept of “soft power” in the literature, using “soft technologies”. In modern democratic states, for the most part, the interaction of authorities with the objects of the socio-political process is ensured by using political communication tools and developing feedback mechanisms. The role of communication relations in the public administration system is growing, and the communication component of political reality is changing and becoming increasingly complicated. Legitimate interaction mechanisms between authorities and society are now formally established in Ukraine. However, their effectiveness is constantly questioned by both political scientists and the very objects of the socio-political process. The strategic transformations currently taking place in the country’s political life, following a change during political and socio-economic development, also suggest a change in the political and communication component of the political process. At the same time, the government itself at the highest level puts forward new requirements for political communication of the authorities, which consist of a reorientation to an open discussion of the strategies and directions of the country’s development, as well as a transition to an open and interactive format of interaction. Keywords: public administration, communication, public relations, public communication, stages of communication.

The Essence of High-Tech Warfare in the Organizational and Institutional Security Theory of State Administration

At the turn of the 20th and 21st centuries, fundamental changes occurred in the field of international security. The world community faced fundamentally new challenges and threats. In many regions of the world, interstate rivalry was observed, which led to the outbreak of local wars and military conflicts, which mostly took the form of armed confrontation. Technological progress, the presence of significant military power, the demonstration of determination and its use transformed social relations into more conflictual ones. Gradually, more and more countries of the world are involved in local wars and military conflicts. In this context, it should be noted that the intensity and scale of hostilities during the last thirty years, which took place in different corners of the globe, testify to the growth of dynamic changes in the situation in the combat zone during the use of international coalition forces. At the same time, the strict implementation of the requirements for stable, continuous, operational and covert management of troops during their performance of combat missions prompts the world's leading countries to develop and implement new concepts of information networks and systems. It should be noted that future wars will depend on high-tech intelligence. The priority is to identify the enemy first, before he notices you; blind the enemy's sensors, be it drones or satellites; and disrupt their means and data channels, whether through cyberattacks, electronic warfare, or old-fashioned firepower. Armies will have to develop new forms and methods of application, relying on mobility, dispersion, camouflage and deception measures. Large armies that fail to invest in new technology or develop new doctrine will be overwhelmed by smaller ones that do. "We have to recognize that the old concepts of fighting large tank battles on European land are over," said Boris Johnson, the UK's prime minister, in November 2021. "There are other, more important things in which we should invest. Cyber technologies, this will be the war of the future." Three months later, Russia invaded Ukraine. So, the work defines the problem of incomplete compliance of the current state and readiness of the security and defense sector with regard to the requirements of effective countermeasures against threats to national security and their neutralization, the task of improving this activity, regarding the creation of unified management and communication systems, and horizontal connections are defined connections of these systems and electronic communication networks, which in the future will undoubtedly affect the safe functioning of the national segment of cyberspace.

Quantifying variation in maximum floor accelerations of modular buildings under earthquakes through stochastic nonlinear structural analysis

For earthquake-resistant design of modular buildings, reinforced concrete (RC) cores can be a viable choice as the vertical seismic force resisting system. The maximum floor acceleration determines the maximum inertial force that will be transferred by the connections in the horizontal diaphragm to the RC walls. However, the randomness in the structural properties of RC walls may result in fluctuations in the floor acceleration response. Given the limited number of horizontal inter-module connections in modular buildings, the failure of these connections can have severe consequences. To ensure adequate safety margins in the design of horizontal diaphragm connections, it is essential to account for the variations in maximum floor accelerations. To quantify these variations, a 9-story prototype building with RC walls was examined in this study. Monte Carlo simulations were conducted on sample structures with univariate and bivariate randomness in fc (concrete cylinder compressive strength) and Fy (yield strength of steel rebars) of RC walls. Nonlinear response history analyses were performed for each sample structure using 22 ground motions to account for uncertainty in earthquake excitation. The results demonstrated significant and highly complex variations in the maximum floor accelerations due to the randomness considered. A coefficient of variation (CoV) of 0.13 was determined for the maximum floor acceleration response resulting from the bivariate randomness in fc and Fy. Furthermore, the variations were found to increase as the correlation scale in the spatial variation of fc increased. Based on the findings, it is proposed to apply an increase ratio of 1.2 to the maximum floor acceleration to account for the randomness of RC wall properties to ensure adequate safety margins in the design of horizontal diaphragm connections.

Systems of second order differential equations as auto-parallel equations

Nonlinear connections and associated horizontal Berwald-type connections whose auto-parallel equations coincide with an arbitrary system of second order differential equations analytic in the velocities are constructed explicitly. For autonomous Lagrangian systems the nonlinear connection can be chosen in such a way that the horizontal derivative of the conserved Hamiltonian vanishes identically. For natural Lagrangian systems this connection is equivalent to the Levi-Civita connection of the associated Jacobi metric. The connection constructed from the Euler-Lagrange equations of a particle in an electromagnetic and gravitational background naturally provides a unified geometrical description of classical fundamental interactions.

싱가포르 중학교 수학교과서에서의 빅 아이디어 접근 구현 사례 연구

Big Ideas approach is gaining attention as a design and implementation perspective for curriculum that intends connected and coherent mathematics learning. This study conducted quantitative and qualitative analysis on horizontal connections between mathematical content in middle school mathematics textbooks of Singapore where Big Ideas approach was applied. The quantitative analysis revealed the strength of horizontal connections within strands and within topics by Big Ideas. Among the eight Big Ideas in Singapore mathematics curriculum, “diagrams” and “notations” aided generally high level of horizontal connections, while “functions,” “invariance,” and “models” promoted generally lower level. The qualitative analysis distinguished between process-oriented and concept-oriented Big Ideas. Horizontal connections by process-oriented Big Ideas were further classified into “connections by conventional mathematical practices” and “connections through non-routine mathematical reasoning”, while horizontal connections by concept-oriented Big Ideas were classified as “deductive connections based on definitions” and “inductive connections based on awareness of structure”. Results are discussed and implications for the implementation of Big Ideas approach in the 2022 revised mathematics curriculum are suggested.

О разработке инновационных стратегий устойчивого развития России

The current domestic strategizing practice needs significant improvements. On the one hand, innovative strategies should factor in the extreme variability of external environment. On the other hand, they should address long-term trends and goals, e.g., climate change, low-carbon economy, etc. This research featured the industrial strategizing of the Russian economy. In spite of the rapid changes postulated by the concepts of VUCA and BANI, proper strategizing can support effective transformations of companies and industries by cascading and synchronizing different economic policies. Most state-approved industrial strategies provide an effective in-depth situation analysis and problem definition but, being aimed at solving current problems, lack a long-term vision. As a result, they turn into catch-up development strategies that are unable to form leading positions in the future. The long-term goal of any innovative strategy is to develop the existing competencies, competitive advantages, and resource opportunities in order to attract additional resources and create new competitive advantages. Initially, industrial strategies can be limited to minimum allowable investment level that provide effective interaction between business, science, and the state, e.g., special economic zones, industrial clusters, digital platforms, etc. The resulting horizontal connections protect the economic system from the changing external environment.

Improved segmentation of basal ganglia from MR images using convolutional neural network with crossover-typed skip connection.

Accurate and automatic segmentation of basal ganglia from magnetic resonance (MR) images is important for diagnosis and treatment of various brain disorders. However, the basal ganglia segmentation is a challenging task because of the class imbalance and the unclear boundaries among basal ganglia anatomical structures. Thus, we aim to present an encoder-decoder convolutional neural network (CNN)-based method for improved segmentation of basal ganglia by focusing on skip connections that determine the segmentation performance of encoder-decoder CNNs. We also aim to reveal the effect of skip connections on the segmentation of basal ganglia with unclear boundaries. We used the encoder-decoder CNNs with the following five patterns of skip connections: without skip connection, with full-resolution horizontal skip connection, with horizontal skip connections, with vertical skip connections, and with crossover-typed skip connections (the proposed method). We compared and evaluated the performance of the CNNs in the experiment of basal ganglia segmentation using T1-weighted MR brain images of 79 patients. The experimental results showed that the skip connections at each scale level help CNNs to acquire multi-scale image features, the vertical skip connections contribute on acquiring finer image features for segmentation of smaller anatomical structures with more blurred boundaries, and the crossover-typed skip connections, a combination of horizontal and vertical skip connections, provided better segmentation accuracy. This paper investigated the effect of skip connections on the basal ganglia segmentation and revealed the crossover-typed skip connections might be effective for improving the segmentation of basal ganglia with the class imbalance and the unclear boundaries.

Farming for the patchy Anthropocene: The spatial imaginaries of regenerative agriculture

AbstractWith its focus on the species level of the Anthropos, there is growing concern that the Anthropocene analytic lacks the conceptual nuance needed to grapple with the unevenly distributed harms and responsibilities tied up with issues of biodiversity loss, global warming, and land use change. Conceptual variants like the patchy Anthropocene have been proposed to better capture the justice implications of these socio‐ecological crises, directing attention to their spatially ubiquitous yet context‐specific character. The figure of the plantation has come to play an important role in this scholarship due to the contribution intensive agriculture had made to these interlinking crises. Through empirical study of the regenerative agricultural movement, this paper reflects on how regenerative farmers use different sites (fields, soils, livestock stomachs) to apprehend their agro‐ethical responsibilities to more‐than‐human actors both near to and far from the landscapes they manage. Our aims here are two‐fold. First, we provide a more affirmative account of agricultural management than is currently offered by plantation farming: a model of food production that is not just ‘in’ the Anthropocene, but ‘for’ it. Second, we contribute to ongoing discussions unfolding in the social sciences around the tools needed to conceptualise the interlinking spatial and justice aspects of the Anthropocene transition. By bringing the patchy analytic into conversation with more established geographic writing on scale, volume, and horizontal connections, we show the merit of juxtaposing multiple models of spatial relation as a way of gaining ethical and conceptual traction on complex socio‐ecological issues. We argue that the ‘polymorphic’ spatial imaginaries of regenerative agriculturalists can offer some guidance on the tools needed to attend to the specificity of local Anthropocene outcomes in relation to socio‐ecological forces actuating the world at much greater spatio‐temporal scales.

Refresh Rate-Based Caching and Prefetching Strategies for Internet of Things Middleware.

One of the research directions in Internet of Things (IoT) is the field of Context Management Platforms (CMPs) which is a specific type of IoT middleware. CMPs provide horizontal connectivity between vertically oriented IoT silos resulting in a noticeable difference in how IoT data streams are processed. As these context data exchanges can be monetised, there is a need to model and predict the context metrics and operational costs of this exchange to provide relevant and timely context in a large-scale IoT ecosystem. In this paper, we argue that caching all transient context information to satisfy this necessity requires large amounts of computational and network resources, resulting in tremendous operational costs. Using Service Level Agreements (SLAs) between the context providers, CMP, and context consumers, where the level of service imperfection is quantified and linked to the associated costs, we show that it is possible to find efficient caching and prefetching strategies to minimize the context management cost. So, this paper proposes a novel method to find the optimal rate of IoT data prefetching and caching. We show the main context caching strategies and the proposed mathematical models, then discuss how a correctly chosen proactive caching strategy and configurations can help to maximise the profit of CMP operation when multiple SLAs are defined. Our model is accurate up to 0.0016 in Root Mean Square Percentage Error against our simulation results when estimating the profits to the system. We also show our model is valid using the t-test value tending to 0 for all the experimental scenarios.

Industry 4.0

Industry 4.0 is considered a new industrial stage in which vertical and horizontal manufacturing processes integration and product connectivity can help companies to achieve higher industrial performance. However, little is known about how industries see the potential contribution of the Industry 4.0 related technologies for industrial performance, especially in emerging countries. Based on the use of secondary data from a large-scale survey of 27 industrial sectors representing 2,225 companies of the Brazilian industry, we studied how the adoption of different Industry 4.0 technologies is associated with expected benefits for product, operations and side-effects aspects. Using regression analysis, we show that some of the Industry 4.0 technologies are seen as promising for industrial performance while some of the emerging technologies are not, which contraries the conventional wisdom. We discuss the contextual conditions of the Brazilian industry that may require a partial implementation of the Industry 4.0 concepts created in developed countries. We summarize our findings in a framework, that shows the perception of Brazilian industries of Industry 4.0 technologies and their relations with the expected benefits. Thus, this work contributes by discussing the real expectations on the future performance of the industry when implementing new technologies, providing a background to advance in the research on real benefits of the Industry 4.0.

Stock price index prediction based on SSA-BiGRU-GSCV model from the perspective of long memory

PurposeBecause the dynamic characteristics of the stock market are nonlinear, it is unclear whether stock prices can be predicted. This paper aims to explore the predictability of the stock price index from a long-memory perspective. The authors propose hybrid models to predict the next-day closing price index and explore the policy effects behind stock prices. The paper aims to discuss the aforementioned ideas.Design/methodology/approachThe authors found a long memory in the stock price index series using modified R/S and GPH tests, and propose an improved bi-directional gated recurrent units (BiGRU) hybrid network framework to predict the next-day stock price index. The proposed framework integrates (1) A de-noising module—Singular Spectrum Analysis (SSA) algorithm, (2) a predictive module—BiGRU model, and (3) an optimization module—Grid Search Cross-validation (GSCV) algorithm.FindingsThree critical findings are long memory, fit effectiveness and model optimization. There is long memory (predictability) in the stock price index series. The proposed framework yields predictions of optimum fit. Data de-noising and parameter optimization can improve the model fit.Practical implicationsThe empirical data are obtained from the financial data of listed companies in the Wind Financial Terminal. The model can accurately predict stock price index series, guide investors to make reasonable investment decisions, and provide a basis for establishing individual industry stock investment strategies.Social implicationsIf the index series in the stock market exhibits long-memory characteristics, the policy implication is that fractal markets, even in the nonlinear case, allow for a corresponding distribution pattern in the value of portfolio assets. The risk of stock price volatility in various sectors has expanded due to the effects of the COVID-19 pandemic and the R-U conflict on the stock market. Predicting future trends by forecasting stock prices is critical for minimizing financial risk. The ability to mitigate the epidemic’s impact and stop losses promptly is relevant to market regulators, companies and other relevant stakeholders.Originality/valueAlthough long memory exists, the stock price index series can be predicted. However, price fluctuations are unstable and chaotic, and traditional mathematical and statistical methods cannot provide precise predictions. The network framework proposed in this paper has robust horizontal connections between units, strong memory capability and stronger generalization ability than traditional network structures. The authors demonstrate significant performance improvements of SSA-BiGRU-GSCV over comparison models on Chinese stocks.

Porosity characterization using medical computed tomography scans of two deeply buried paleokarst aquifers in Silurian carbonates, southern Ontario, Canada

Paleokarst and paleokarst aquifers are not as well-documented as shallow karst, and studies of pores and pore networks are rare. Paleokarst lacks the open conduits typical of karst due to compaction, infilling, and diagenetic recrystallization by deep burial, so groundwater movement is through matrix porosity. In this case study, porosity networks in two saline aquifers in carbonate paleokarst of the Silurian Guelph Formation and Salina A-1 Carbonate Unit in southern Ontario (Canada) have been studied in drill cores at microscopic to macroscopic scales, utilizing medical computed tomography (CT) scans, optical petrography, macroscopic core examination, and scanning electron microscopy. The CT scans provided nondestructive three-dimensional visualization and quantification of pore distribution, size and volume, pore connections, and estimates of total porosity, similar to gas porosimetry. In the A-1 Carbonate, 50% of the pore volume comprises layers of macropores associated with algal laminations, with good horizontal connections. In the Guelph Formation, vuggy macropores contribute most of the pore volume. They are connected through subvertical fractures and rubble-filled karst conduits and by abundant small pores and micropores with poor horizontal connections. The Guelph paleokarst represents a longer period of subaerial exposure as evidenced by its greater thickness and geographic extent, former karst conduits, and near-total destruction of primary sedimentary fabrics. The findings provide real-world examples for construction of laboratory scale models of paleokarst aquifers, demonstrate the value of a multi-scale approach to porosity studies, and showcase the value of medical CT scans with its unique ability to visualize pore connections within drill cores.