Set Of Indices Research Articles

Research on the application of biomechanical theories to e-commerce product selection strategies

In recent years, the proportion of cross-border e-commerce in China’s foreign trade has been steadily increasing. Many enterprises have opted to engage in international trade by establishing a presence on overseas e-commerce platforms, making the integration of research findings from various fields with e-commerce product selection strategies a popular research direction. This study focuses on the Southeast Asian e-commerce platform Lazada and incorporates biomechanical theories to conduct cluster analysis. The objective is to uncover product classification patterns through biomechanical aspects and provide strategic recommendations for product selection to novice cross-border e-commerce merchants seeking entry into the Southeast Asian market. First, this study provides a comprehensive analysis of the current development trends in cross-border e-commerce and the application prospects of biomechanical theories in this field. Subsequently, key variables were selected based on biomechanical concepts such as the “stress-strain” relationship and dynamic equilibrium. These core concepts were utilized to draw analogies with the critical variables in cross-border e-commerce product selection. A set of evaluation indexes for product selection was constructed from two dimensions: product attributes and customer reviews. In this framework, product selection strategies were analogized as state variables, product price and brand strength as “external forces,” and product ratings and online reviews as “internal forces.” Data collection techniques were employed to acquire product data from the first 20 pages of listings across secondary categories on Lazada’s Vietnam platform. The data underwent rigorous cleaning, preprocessing, and descriptive statistical analysis. Finally, a clustering algorithm was used to classify the primary product categories into four distinct clusters. Based on comparative analysis of the features among these clusters, the study quantitatively elucidates the patterns of changes in product category under the combined influence of “internal” and “external” forces, and proposes actionable recommendations for product selection strategies. Based on the findings of this study, biomechanical theory provides new insights into e-commerce product selection strategies, demonstrating promising applicability in this field. From a biomechanical perspective, the study identifies women’s fashion and accessories, as well as home and lifestyle categories, as the most popular segments in the Vietnamese market. However, these categories are characterized by intense price competition, making them unsuitable for novice merchants to enter impulsively. In contrast, the electronics category, driven by robust market demand and promising growth potential, emerges as an ideal product selection direction for foreign trade enterprises with reliable quality assurance. Drawing on biomechanical theory and clustering analysis, this study offers product selection recommendations, emphasizing that merchants should carefully select target categories and products based on their resources and market positioning. By adopting appropriate market strategies, businesses can achieve steady development in the Southeast Asian market, gradually build and enhance their brand image, and drive the long-term growth of their cross-border e-commerce ventures.

Insights in Managing Ungulates Population and Forest Sustainability in Romania

Improved forage and living conditions in certain parts of Europe over the past few decades have led to alarming levels of ungulate densities. Consequently, the overabundance of red deer, roe deer, and fallow deer in the Western Plains of Romania has begun to generate issues in the development of young oak stands. In addition to causing damage to the agricultural sector and increasing the risk of vehicle collisions, ungulates are increasing pressure on the forestry sector, mainly through the browsing of young saplings. This study quantifies the levels of ungulate browsing in oak stands using a permanent sample grid of 42 plots in both natural and artificial regeneration areas. A total of 3223 individual saplings were measured, revealing browsing intensities of 49.65% in clearcut systems and 12.8% in continuous forest cover systems. With high ungulate densities identified as the main cause, the Sustainable Population Threshold was calculated using a complex set of indices and compared to the actual numbers of ungulates, both of which were translated into stock unit equivalents. A logistic regression model was developed based on silvicultural and wildlife indices to identify other factors influencing browsing occurrence. The findings indicate that the proportion of forested areas in the hunting ground and the type of silvicultural system are significant factors in the occurrence of browsing. The problem of ungulate overabundance clearly influences forest development, and new solutions should be identified in terms of both forestry and wildlife management.

Measuring drug policy evolution: A cross-country analysis.

Measuring drug policy evolution: A cross-country analysis.

Sparse estimation of parameter support sets for generalized vector autoregressions by resampling and model aggregation

The central problem we address in this work is estimation of the parameter support set S, the set of indices corresponding to nonzero parameters, in the context of a sparse parametric likelihood model for discrete multivariate time series. We develop an algorithm that performs the estimation by aggregating support sets obtained by applying the LASSO to data subsamples. Our approach is to identify several candidate models and estimate S by selecting common parameters, thus ‘aggregating’ candidate models. While our method is broadly applicable to any selection problem, we focus on the generalized vector autoregressive (GVAR) model class, and particularly the Poisson case, emphasizing applications in network recovery from discrete multivariate time series. We propose benchmark methods based on the LASSO, develop simulation strategies for GVAR processes, and present empirical results demonstrating the superior performance of our method. Additionally, we present an application estimating ecological interaction networks from paleoclimatology data.

Semiconic Idempotent Logic II: Beth Definability and Deductive Interpolation

Semiconic Idempotent Logic II: Beth Definability and Deductive Interpolation

When possessor and argument indexes coincide. A cross-linguistic survey

Abstract Cross-linguistically, it is not uncommon to find the same person indexes in noun and verb phrases, referring, respectively, to the possessor of the noun and to various (combinations of) arguments (A, S and P). This phenomenon has never been the object of a dedicated typological survey. This article seeks to address this gap by investigating cases in which possessor and argument indexes coincide in a variety sample of 225 languages. The parameters of analysis include the (combinations of) arguments indexed, the type of coincidence (total, covering all persons in a given index set, or partial, limited to some persons), the segmental similarity between coinciding argument/possessor indexes and independent pronouns, the restriction of coinciding indexes to specific TAM and/or voice constructions, and the type of possessor indexes involved (alienable vs. inalienable). The typological survey is further complemented by a discussion of diachronic scenarios that may explain these patterns of coincidence, including (but not limited to) parallel developments from independent pronouns and the reinterpretation of nominalized forms of the verb (where possessor indexes correspond to an argument of the full verb) as predicative forms.

Real-Time Evaluation of Ground Insulation Degradation and Fault Warning Method Under Multiple Operating Conditions for Train Traction Drive System.

Aiming at the problem that the main circuit grounding fault in the traction drive system of locomotives and high-speed trains can only be diagnosed under a single operating condition and cannot be warned about early, a mechanism and data-driven real-time evaluation and full operating condition fault warning method for ground insulation degradation is proposed. Firstly, based on the mechanism of grounding faults, the circuit characteristics of the main circuit of the traction transmission system under different grounding fault conditions are analyzed, and mathematical models are established for the detection of various grounding faults and sensor signals under different operating conditions, as well as for evaluating the degree of degradation of grounding faults. Secondly, based on engineering application experience, a feature index set that can accurately classify different types of grounding faults is extracted. Combined with on-site fault case data, a decision tree method is used to establish a classification model between the feature index set and typical grounding fault sources under different operating conditions, which is then converted into a fault diagnosis rule library. Finally, real-time collection of relevant sensor signals, based on the fault diagnosis rule library and the degradation degree evaluation model of grounding faults, enables real-time detection and warning of grounding faults under all operating conditions to ensure train safety and provide key information support for optimal degraded operation in the future. The test result based on controller hardware in the loop shows that the method proposed in this paper can achieve accurate detection and localization of grounding faults under different operating conditions and can provide real-time warning of the severity of grounding faults, which has good engineering application value.

An approach to comprehensive assessment of the post-COVID quality of life in the children

The scientific literature around the world reports on the increasing problem of post-COVID syndrome in children affecting their quality of life. Post-COVID syndrome is a clinical condition that occurs several weeks after an episode of acute COVID-19 infection, which resulted in clinical recovery accompanied by nonspecific neurological symptoms, skin vasculitis, mental disorders and impaired functions of different organs. Significant difficulties in diagnosis and medical and preventive measures are caused by the lack of accurate definitions and diagnostic criteria, which currently allows us to determine post-COVID syndrome as a “diagnosis of exclusion”. The purpose of our present study was to develop an approach to comprehensive assessment of the life quality in children with post-COVID syndrome. COVID-19 infection was diagnosed on the basis of anamnestic data, medical repotrts, results of clinical, laboratory and instrumental studies, consulting with narrow specialists, in accordance with the “ICD 10th revision”. An objective assessment of QOL was based on a set of indices of general clinical blood and urine tests, biochemical parameters, evaluation of immunological status, cardiovascular system, autonomic nervous system, psychoemotional status, and the state of cognitive functions. We studied the initial vegetative tone, the level of memorization, the stability of attention and the performance dynamics, work efficiency, degree of working ability and mental stability, self-assessment scale for the anxiety levels. To diagnose the psychophysiological state of the persons, determine their requests and needs, expectations and attitudes, volitional abilities and stress coping, to assess relationships with people, analyze sources of stress, anxiety, and internal conflicts, the Lusher method (color test) was used. The study has shown development of vegetative, psychoemotional and cognitive disorders after COVID-19 infection, which cause significant discomfort in daily life in children and adolescents which persist for a considerable time, which, in turn, significantly reduces the quality of life in children and adolescents with post-COVID syndrome. The developed method of comprehensive quality of life assessment in the children with post-COVID syndrome is aimed at determining clear objective criteria for assessing the quality of life, thus allowing further evaluation of life quality in this patient population, but also specify medical control over all children and adolescents, and those who suffered from COVID-19, and require further observation by neurologists, psychoneurologists, neuropsychologists, speech therapist, psychologist and psychiatrician.

New Families of Strength‐3 Covering Arrays Using Linear Feedback Shift Register Sequences

ABSTRACTIn an array over an alphabet of symbols, a ‐set of column indices is covered if each ‐tuple of the alphabet occurs at least once as a row of the sub‐array indexed by . A covering array, denoted by CA, is an array over an alphabet with symbols with the property that any ‐set of columns is covered. Here, is the size and is the strength of the covering array. Raaphorst et al. (Des. Codes Cryptogr. (2014) 73:949‐968) give a construction for a CA, which we denote as , by using linear feedback shift register (LFSR) sequences with characteristic polynomial being a primitive polynomial over . The array corresponds to a covering perfect hash family. We give a construction of covering arrays of strength 3 based on horizontally concatenating copies of , for any prime power and . The coverage is completed by developing Roux‐type constructions that exploit the structure of and remove repeated rows. Some of these covering arrays improve the previous best‐known upper bound of the size of covering arrays with the same corresponding parameters.

The centimeter emission from planet-forming disks in Taurus

The last decade has witnessed remarkable advances in the characterization of the (sub-)millimeter emission from planet-forming disks. Conversely, the study of (sub-)centimeter emission has made more limited progress, to the point that only a few exceptional disk-bearing objects have been characterized in the centimeter regime. This work takes a broad view of the centimeter emission from a large sample with Karl G. Jansky Very Large Array (VLA) observations that is selected from previous Atacama Large (sub-)Millimeter Array (ALMA) surveys of more representative disks in brightness and extent . We report on the detection and characterization of flux at centimeter wavelengths from 21 sources in the Taurus star-forming region. Complemented by literature and archival data, the entire photometry from 0.85 mm to 6 cm is fit by a two-component model that determines the ubiquitous presence of free-free emission entangled with the dust emission. The flux density of the free-free emission is found to scale with the accretion rate but is independent of the outer-disk morphology depicted by ALMA. The dust emission at 2 cm is still appreciable and offers the possibility to extract an unprecedented large set of dust spectral indices in the centimeter regime. A pronounced change between the median millimeter indices (2.3) and centimeter indices (2.8) suggests that a large portion of the disk emission is optically thick up to 3 mm. The comparison of both indices and fluxes with the ALMA disk extent indicates that this portion can be as large as 40 au and suggests that the grain population within this disk region that emits the observed centimeter emission is similar in disks with different sizes and morphologies. All these results await confirmation and dedicated dust modeling once facilities such as next generation VLA (ngVLA) or Square Kilometre Array (SKA)-mid are able to resolve the centimeter emission from planet-forming disks and disentangle the various components.

Hygienic assessment of the ionic composition of drinking water of the centralized water supply of the Vladimir region

Introduction. The paper presents the results of a study on the hygienic assessment of the cationic-anionic composition of drinking water of centralized water supply in the administrative centers of the Vladimir region. Materials and methods. The object of the study was the water of the sources of the central water supply of the administrative centers of the Vladimir region. The content of water-soluble forms of anions and cations was determined by capillary electrophoresis. There were compared concentration values ​​with maximum permissible concentrations (MPC) and ranges of permissible hygienic standards (RHS). Results. In some administrative centers, there has been established concentrations of nitrate ions, phosphate ions, magnesium ions, hardness exceeding the maximum permissible concentrations in drinking water of centralized water supply. Non‒compliance with permissible hygienic standards for chlorides in 16 localities was revealed as follows: for sulfates – in 11; for potassium ions – in 8; for sodium ions – in 9; for magnesium ions – in 3. Non-compliance with minimum RHS for calcium ions was found in the one city. The excess of RHS was noted in seven administrative centers for calcium ions. The drinking water of centralized sources in the city of Petushki is characterized by the highest compliance with hygienic standards (MPC and RHS) according to a set of indices; the smallest is the city of Murom. Limitations are related to the one-time selection and small number of samples, which fails to allow for a broader interpreting of the obtained data. Conclusion. The use of drinking water, the quality of which does not meet sanitary and hygienic requirements, may cause an increase in both the level of general morbidity of the population and in certain nosological forms. In order to reduce the potential adverse impact of drinking water with a high content of nitrate ions, phosphate ions, hardness salts on health, the population is recommended to use household water purification filters, the principle of operation of which is based on methods of adsorption and ion exchange, as well as to use household reverse osmosis systems with a mineralizer, allowing to purify drinking water by the membrane method get rid of excess anions and hardness salts and saturate it with trace elements necessary for the human body.

EFGs: A Complete and Accurate Implementation of Ertl's Functional Group Detection Algorithm in RDKit.

Functional groups are widely used in organic chemistry, because they provide a rationale to analyze physicochemical and reactivity properties. In medicinal chemistry, they are the basis for analyzing ligand-biomacromolecule interactions. Ertl's algorithm is an approach to extract functional groups in arbitrary organic molecules that does not depend on predefined libraries of functional groups. However, there is a lack of a complete and accurate implementation of Ertl's algorithm in the widely used RDKit cheminformatic toolkit. In this paper, a new RDKit/Python implementation of the algorithm is described, that is both accurate and complete. For a RDKit molecule, it provides (i) a PNG binary string with an image of the molecule with color-highlighted functional groups; (ii) a list of sets of atom indices (idx), each set corresponding to a functional group; (iii) a list of pseudo-SMILES canonicalized strings for the full functional groups; and (iv) a list of RDKit labeled mol objects, one for each full functional group. The code is freely available in https://github.com/bbu-imdea/efgs and is part of the RDKit Contrib directory (https://github.com/rdkit/rdkit/tree/master/Contrib/efgs).

THE COMPLEXITY OF ORDER-COMPUTABLE SETS

Abstract This paper studies the conjecture of Hirschfeldt, Miller, and Podzorov in [13] on the complexity of order-computable sets, where a set A is order-computable if there is a computable copy of the structure $(\mathbb {N}, <,A)$ in the language of linear orders together with a unary predicate. The class of order-computable sets forms a subclass of $\Delta ^{0}_{2}$ sets. Firstly, we study the complexity of computably enumerable (c.e.) order-computable sets and prove that the index set of c.e. order-computable sets is $\Sigma ^{0}_{4}$ -complete. Secondly, as a corollary of the main result on c.e. order-computable sets, we obtain that the index set of general order computable sets is $\Sigma ^{0}_{4}$ -complete within the index set of $\Delta ^{0}_{2}$ sets. Finally, we continue to study the complexity of more general $\Delta ^{0}_{2}$ sets and prove that the index set of $\Delta ^{0}_{2}$ sets is $\Pi ^{0}_{3}$ -complete.

Seismic Damage Assessment of Reinforced Concrete Structures: Low, Medium, and High Rises Using a Performance-Based Seismic Design Approach

Purpose: The research addresses the limitations of the traditional force-based approach in earthquake-resistant design, particularly its inability to account for inelastic behaviour fully. It explores the potential of nonlinear static assessment techniques within the performance-based seismic design (PBSD) framework to provide a more accurate measure of earthquake structural performance. Design/Methodology/Approach: This research develops a set of damage indices to quantify structural damage in moment-resisting frames (MRFs) based on engineering demand parameters obtained through nonlinear analysis. The study examines reinforced concrete (R.C.) structures of various heights, evaluating their seismic load-bearing capacity and resilience using the PBSD approach. Findings: The proposed damage indices offer a reasonable way to quantify structural damage and enhance the understanding of the plastic collapse process. Performance-based design mainly benefits R.C. structures, improving their seismic resilience and cost-effectiveness. Research Limitation: Accurately quantifying building damage remains challenging even with nonlinear assessment tools. Further work is required to refine these tools for more precise damage quantification in various building types. Practical Implication: The findings have practical implications in reducing repair costs and ensuring public safety by providing preliminary damage estimates for tall buildings. The PBSD approach also meets acceptance criteria for immediate occupancy and life safety across various seismic intensities. Social Implication: By enhancing buildings' resilience to earthquakes, this research contributes to safer urban environments, reducing potential fatalities, economic losses, and downtime associated with earthquake-induced damage. Originality/Value: This study provides valuable insights into performance-based seismic design and presents a practical method for quantifying structural damage in R.C. structures. The proposed damage indices and PBSD approach significantly advance the safety and cost-effectiveness of earthquake-resistant buildings.

A dataset of Uniswap daily transaction indices by network

Decentralized Finance (DeFi) is reshaping traditional finance by enabling direct transactions without intermediaries, creating a rich source of open financial data. Layer 2 (L2) solutions are emerging to enhance the scalability and efficiency of the DeFi ecosystem, surpassing Layer 1 (L1) systems. However, the impact of L2 solutions is still underexplored, mainly due to the lack of comprehensive transaction data indices for economic analysis. This study bridges that gap by analyzing over 50 million transactions from Uniswap, a major decentralized exchange, across both L1 and L2 networks. We created a set of daily indices from blockchain data on Ethereum, Optimism, Arbitrum, and Polygon, offering insights into DeFi adoption, scalability, decentralization, and wealth distribution. Additionally, we developed an open-source Python framework for calculating decentralization indices, making this dataset highly useful for advanced machine learning research. Our work provides valuable resources for data scientists and contributes to the growth of the intelligent Web3 ecosystem.

Financial Reporting Quality of Licensed Financial Institutions in Sri Lanka: A Comparative Analysis Across Historical Cost and Fair Value Accounting Regimes

This study aims to develop a comprehensive framework to measure the financial reporting quality (FRQ) of licensed financial institutions (LFIs) in Sri Lanka and assess the FRQ of the fair value accounting regime over the historical cost regime. This study uses a quantitative design based on positivism to assess the FRQ. The sample size comprised 44 LFIs where the historical cost and fair value accounting regimes were assessed considering annual reports published in 2011 and 2021 respectively. Structured content analysis is used to collect data to assign a quantitative or numeric value for each item to capture FRQ dimensions under the conceptual framework. A comprehensive set of FRQ indices were developed to assess FRQ and the indices were compared using a t-test across historical cost and fair value accounting regimes. The analysis reveals that the FRQ of LFIs in Sri Lanka has improved significantly in the fair value accounting regime over the historical cost regime. However, regulatory disclosure requirements adhering to the strengthened corporate governance regime were also effective during the transition period Therefore, the IFRS adoption may not be the sole contributing factor to the improved FRQ in the fair value accounting regime. Hence, future studies may focus on assessing FRQ considering fair value-based earnings management practices and extend the scope of FRQ to evolving financial technology which may play an important role in FRQ.

Nowcasting the State of the Economy: An Application of Linear Combinations of Dynamic Common Factors to the Colombian Economy

The main goal of this work is to propose a general methodology to create a coincident index for the economy of a given country or region based on linear combinations of dynamic common factors, and to validate it on simulated scenarios and on a case study for Colombia. The methodology proposed can effectively handle both stationary and nonstationary macroeconomic variables as input and provides tools to obtain point estimates and confidence regions, and to test hypotheses for the linear-combination coefficients. This work highlights how promising this new proposal is in terms of its contribution with respect to its antecedents in the literature, by showcasing situations in which a linear combination of dynamic factors can enhance the accuracy of the nowcast and address potential problems and limitations of considering only one dynamic factor as index. The application of this work to the Colombian economy is based on the macroeconomic analysis conducted by previous researchers. This work, however, considers and analyzes a much larger set of candidate indices via linear combinations of factors, providing consistent results; which strengthens and validates their previous findings.

Ligand impacts on band edge energies and excited state splittings of silicane.

Two-dimensional (2D) silicanes are promising semiconductors for applications in optoelectronics and photochemistry. Covalent functionalization presents a facile strategy to customize silicanes to attain desired properties. A comprehensive understanding of the impacts of ligands on silicanes is thus pivotal. In this study, we perform density functional theory (DFT) and time-dependent DFT (TDDFT) calculations to investigate the effects of three typical classes of ligands: (1) σ-withdrawing and π-donating, (2) σ-withdrawing and π-withdrawing, and (3) σ-donating and π-withdrawing, on the geometric structure, electronic structure, and band edge excited states of silicanes. Covalent functionalization of silicanes enables a wide range of band edge energies. The band gaps can be tuned between indirect and direct, and the underlying mechanism is explained for the first time. Additionally, TDDFT calculations confirm that the band edge optical absorptions can be adjusted by the ligands broadly from the near-infrared to the visible light region. These desirable properties enhance the functionalities of silicanes. Methodologically, we discuss the applicability of using the conventional one-particle orbital model to describe the excited states of silicanes, and nail down the ∼0.1 eV inaccuracy of the model in describing excited state splittings. We present empirical functions for quick estimations of band edge energies of covalently functionalized silicanes. Through careful comparisons, we justify the use of the carbon-adapted σ/π-donating/accepting indices of typical ligands in silicon chemistry and present a set of silicon-based indices for future prudent applications in inorganic computational studies of silicon-based materials.

A Customized Local Energy Trading Approach Using A Comprehensive Set of Performance Indices

A Customized Local Energy Trading Approach Using A Comprehensive Set of Performance Indices

Bender–Knuth Billiards in Coxeter Groups

Abstract Let $(W,S)$ be a Coxeter system, and write $S=\{s_i:i\in I\}$ , where I is a finite index set. Fix a nonempty convex subset $\mathscr {L}$ of W. If W is of type A, then $\mathscr {L}$ is the set of linear extensions of a poset, and there are important Bender–Knuth involutions $\mathrm {BK}_i\colon \mathscr {L}\to \mathscr {L}$ indexed by elements of I. For arbitrary W and for each $i\in I$ , we introduce an operator $\tau _i\colon W\to W$ (depending on $\mathscr {L}$ ) that we call a noninvertible Bender–Knuth toggle; this operator restricts to an involution on $\mathscr {L}$ that coincides with $\mathrm {BK}_i$ in type A. Given a Coxeter element $c=s_{i_n}\cdots s_{i_1}$ , we consider the operator $\mathrm {Pro}_c=\tau _{i_n}\cdots \tau _{i_1}$ . We say W is futuristic if for every nonempty finite convex set $\mathscr {L}$ , every Coxeter element c and every $u\in W$ , there exists an integer $K\geq 0$ such that $\mathrm {Pro}_c^K(u)\in \mathscr {L}$ . We prove that finite Coxeter groups, right-angled Coxeter groups, rank-3 Coxeter groups, affine Coxeter groups of types $\widetilde A$ and $\widetilde C$ , and Coxeter groups whose Coxeter graphs are complete are all futuristic. When W is finite, we actually prove that if $s_{i_N}\cdots s_{i_1}$ is a reduced expression for the long element of W, then $\tau _{i_N}\cdots \tau _{i_1}(W)=\mathscr {L}$ ; this allows us to determine the smallest integer $\mathrm {M}(c)$ such that $\mathrm {Pro}_c^{{\mathrm {M}}(c)}(W)=\mathscr {L}$ for all $\mathscr {L}$ . We also exhibit infinitely many non-futuristic Coxeter groups, including all irreducible affine Coxeter groups that are not of type $\widetilde A$ , $\widetilde C$ , or $\widetilde G_2$ .