Search Results (21)

Poor code locality in virtual memory systems significantly contributes to page faults, leading to degraded system performance. Although many solutions aim to minimize page faults, most rely on clustering techniques that do not quantify the approximation error relative to the optimal solution. In this work, we develop a novel mathematical model based on the Working Set strategy combined with a geometric interpretation of the computational process via a Hasse diagram. This approach enables the reduction of the problem dimensionality and facilitates identification of critical control states under realistic constraints. We formalize the minimization of expected page faults as a discrete optimization problem with well-defined functionals and constraints. Experimental evaluation demonstrates that our model achieves lower average page faults and execution times compared to classical algorithms, especially under poor code locality conditions. Our method also provides a foundation for obtaining ε-optimal solutions and paves the way for designing efficient and cost-effective page replacement algorithms with provable guarantees. These contributions establish both theoretical and practical advances in virtual memory management. Full article

A partially ordered set (or a poset, for short) is a set endowed with a partial order relation, i.e., with a reflexive, anti-symmetric, and transitive binary relation. As mathematical objects, posets have been intensively studied in the last century, coming to play essential roles in pure mathematics, logic, and theoretical computer science. More recently, they have been increasingly employed in data analysis, multi-criteria decision-making, and social sciences, particularly for building synthetic indicators and extracting rankings from multidimensional systems of ordinal data. Posets naturally represent systems and phenomena where some elements can be compared and ordered, while others cannot be and are then incomparable. This makes them a powerful data structure to describe collections of units assessed against multidimensional variable systems, preserving the nuanced and multi-faceted nature of the underlying domains. Moreover, poset theory collects the proper mathematical tools to treat ordinal data, fully respecting their non-numerical nature, and to extract information out of order relations, providing the proper setting for the statistical analysis of multidimensional ordinal data. Currently, their use is expanding both to solve open methodological issues in ordinal data analysis and to address evaluation problems in socio-economic sciences, from multidimensional poverty, well-being, or quality-of-life assessment to the measurement of financial literacy, from the construction of knowledge spaces in mathematical psychology and education theory to the measurement of multidimensional ordinal inequality/polarization. Full article

Identifying and ranking the key drivers of grassland conversion at the county level is crucial for developing targeted policies and improving protection efficiency. However, this process faces methodological challenges because of spatial and temporal variability. Partial order theory offers a robust framework for addressing these complexities. This study applies partial order theory (POT) combined with the Hasse diagram technique (HDT) to analyze grassland conversion in the Hohhot–Baotou–Ordos region during two time periods (2000–2010 and 2010–2020). First, patterns of grassland transformation are quantified, and the dominant driving factors of grassland conversion out (GCO) are identified and ranked, highlighting regional differences and temporal shifts. By integrating POT and HDT, this study offers a novel approach to handling complex, nonlinear, and hierarchical relationships among multiple drivers. The results provide scientific insight and policy recommendations for region-specific grassland management and sustainable land-use planning. The results show that (1) transitions between grasslands and other land-use types became more frequent across the two periods. Specifically, the rates of grassland conversion out and conversion increased from 2.1% and 3.5% during the period 2000–2010 to 4.7% and 4.8% during the period 2010–2020, respectively. (2) Urbanization was the primary driver of grassland conversion in 11 and 10 of the 18 counties during the first and second periods, respectively, followed by factors related to weather variables. (3) In the future, the eastern region of the study area needs to prioritize mitigating the impacts of urban development, while the western region should focus on enhancing ecological construction projects. This study recommends adopting region-specific ecological protection and economic strategies for balanced outcomes in conservation and development. Full article

Basketball games are characterized by the large number of lineups that can be used by the coach during a game, e.g., with 12 players there are 792 possible lineups. This has led to the development of several statistics for the combinations of players on the court since team performance depends on synergy among players. It is of primary importance for a basketball team to understand the team performance and aid the coaching staff in making the proper decisions. In this work, we apply data mining and knowledge extraction techniques to basketball analytics. In particular, we propose an algorithm for answering questions (including filtering and maximization) about the team performance when any K-Player lineup is on the court ($1\le K\le 5$). The algorithm uses a semilattice representation and a depth-first search traversal that incrementally computes the statistics by exploiting set theory properties. As a case study, we provide experiments by using lineups mainly from the EuroLeague Basketball but also from the National Basketball Association (NBA). Regarding the results, the proposed method is more than 30× faster than the baseline for the EuroLeague and 200× faster for the NBA. Indicatively, we can compute the key traditional cumulative and average statistics for all K-Player combinations of players of the EuroLeague of a single season in less than 1 s. Finally, we introduce indicative statistics using the computations mentioned. Full article

In this paper, we express ${\sum }_{n,m\ge 1}{\displaystyle \frac{{\mathit{\epsilon }}_1^n{\mathit{\epsilon }}_2^m{M}_n^{\left(u\right)}{M}_m^{\left(v\right)}}{n^r{m}^s{(n+m)}^t}}$ as a linear combination of alternating multiple zeta values, where ${\mathit{\epsilon }}_i\in \{1,-1\}$ and $M_k^{\left(u\right)}\in \{H_k^{\left(u\right)},{\overline{H}}_k^{\left(u\right)}\}$, with $H_k^{\left(u\right)}$ and ${\overline{H}}_k^{\left(u\right)}$ being harmonic and alternating harmonic numbers, respectively. These sums include Subbarao and Sitaramachandrarao’s alternating analogues of Tornheim’s double series as a special case. Our method is based on employing two different techniques to evaluate the specific integral associated with a 3-poset Hasse diagram. Full article

In this paper, we solve the open problem posed by Kuba by expressing ${\sum }_{j,k\ge 1}\frac{H_k^{\left(u\right)}{H}_j^{\left(v\right)}{H}_{j+k}^{\left(w\right)}}{j^r{k}^s{(j+k)}^t}$ as a linear combination of multiple zeta values. These sums include Tornheim’s double series as a special case. Our approach is based on employing two distinct methods to evaluate the specific integral proposed by Yamamoto, which is associated with the two-poset Hasse diagram. We also provide a new evaluation formula for the general Mordell–Tornheim series and some similar types of double and triple series. Full article

The current standards used for nitrogen pollution evaluation are lacking, and scientific classification methods are needed for nitrogen pollution to improve water quality management capabilities. This study addresses the important issue of assessing surface water nitrogen pollution by utilizing two advanced multivariate statistical techniques: self-organizing maps (SOMs) obtained using the K-means algorithm and the Hasse diagram technique (HDT). The research targets of this study are the rivers of the megacity Chengdu, China. Samples were collected on a monthly basis in 2017–2020 from different sites along the rivers, and their nitrogen pollution parameters were determined. The grouping of nitrogen pollution parameters and the clustering of sampling events using SOMs facilitate the preprocessing required for the HDT, wherein clusters are ordered according to the pre-clustered water sampling events. The results indicate that nitrogen pollution in the Chengdu River Basin, which is prominent and mainly driven by nitrate nitrogen, can be categorized into five levels. The nitrogen pollution in Tuo River is serious. Although the degree of ammonia nitrogen pollution in Jin River is higher, the pollution range is smaller. Furthermore, these results were evaluated by the SOMs and HDT to be clear and reliable. Overall, these findings can provide a basis for local environmental legislation. Full article

Approximately one-third of the food produced globally—close to 1 billion tons—ends up as waste, and, at the same time, more than 800 million people are undernourished, which makes Sustainable Development Goal 12.3, to halve food waste by 2020, rather ambitious if not illusory. In the present study, data on food waste in households, the food service sector, and the retail sector are used as indicators for 78 countries that are analyzed by applying a partial order methodology—allowing all indicators to be taken into account simultaneously—to disclose the “good” (below average) and the “bad” (above average) among the countries on an average scale. Countries such as Belgium, Japan, and Slovenia should be labeled as “good” in this context, whereas the “bad” includes countries such as Nigeria, Rwanda, and Tanzania, countries that must cope simultaneously with severe malnutrition and hunger. This study further includes a search for so-called peculiar countries. Here, the USA and Ireland pop up, as they have very high amounts of waste in their food service sectors due to their eating profiles. Finally, the possible influence of assigning a higher weight to household waste is discussed. The overall objective of this study is to contribute to the necessary decisions that need to be made in order to fight the food waste problem and, thus, fulfill Sustainable Development Goal No. 2—zero hunger. As the world produces enough food for everyone, it is unacceptable that more than 800 million people are undernourished and that 14 million children suffer from stunting; perhaps all countries call for the label “ugly”. The present study contributes to highlighting the food waste problem and suggests specific action points for the studied countries. Full article

The aim of is paper is to address the problem of identifying critical factors in the analysis of non-coal mine explosion accidents as well as to improve the rationality and accuracy of the risk analysis results. Hence, we developed a risk identification method for non-coal mine explosion accidents, combining the Systems-Theoretic Accident Model and Process (STAMP) and the Rank-order Centroid (ROC) method based on the Poset decision-making theory. The proposed method was applied to identify risk in engineering cases. Findings showed that four main dangerous events (out of twelve identified ones) were the primary culprits of related accidents, which were the events “Blasters without licenses and illegal operation” at the basic level, the event of “the confusion about the safety management system of non-coal mine companies” at the control level, and the event of “the failure about the emergency management departments” and “public security departments” at the supervision level. The approximate values of the average rank of the four events are 11.56, 10.4, 4.33, 4.33. The results of risk identification of non-coal mine explosion accidents based on Poset were consistent with the results obtained by the method used in the case study. This study extends the methods for identifying risks of non-coal mine explosion accidents and facilitates the formulation of effective preventive measures. Full article

Multi-criteria decision analyses (MCDA) for prioritizations may be performed applying a variety of available software, e.g., methods such as Analytic Network Process (ANP) and Elimination Et Choice Translating Reality (ELECTRE III) as recently suggested by Kalifa et al. In addition to a data matrix, usually based on indicators and designed for describing the parts of the framework intended for the MCDA, these methods require input of a variety of other parameters that are not necessarily immediately obtainable. Often the indicators are simply combined by a weighted sum to obtain a ranking score, which is supposed to reflect the opinion of a multitude of stakeholders. A single ranking score facilitates the decision as a unique ordering is obtained; however, such a ranking score masks potential conflicts that are expressed by the values of the single indicators. Beyond hiding the inherent conflicts, the problem arises that the weights, needed for summing up the indicator values are difficult to obtain or are even controversially discussed. Here we show a procedure, which takes care of potential different weighting schemes but nevertheless does not mask any inherent conflicts. Two examples are given, one with a small (traffic) system and one with a pretty large data matrix (food sustainability). The results show how decisions can be facilitated even taking a multitude of stakeholder opinions into account although conflicts are not necessarily completely eliminated as demonstrated in the second case. Full article

With the development of animal husbandry, environmental pollution caused by livestock and poultry breeding (LPB) has become a major problem faced by environmental protection departments. In response to this problem, this study established a spatial suitability evaluation system for LPB. According to the particularity of the indicators, there is a nonlinear relationship after quantification and not all elements in the matrix presented by the indexes and evaluation units have an ‘order’ relationship. Therefore, this study selects a method of combining a self-organising map network. The Hasse diagram technique and geographic information system were used to evaluate the suitability of LPB. Practical application research was conducted in Wangkui County. Most regions of Wangkui County are unsuitable for LPB, accounting for 81.23% of the total area of the county. A small part of a suitable region (434.76 km²) was determined to be a potential site for LPB. According to the results of suitable breeding regions, 17 existing large-scale livestock and poultry farms (LPFs) with unreasonable distribution were optimised for space, which are located in an urban construction area. Spatial optimisation was performed using GIS buffer and overlay analyses, providing the best relocation plot for these 17 LPFs. The results provide a scientific basis for the utilisation of livestock manure and spatial layout planning for LPB. Full article

Rating the potential land use for crop production and/or ranching is typically a process where production gains counterbalance environmental losses. Whereas the production gains are often easy to verify, the environmental losses may render visibility through the changes in the ecosystem service, such as water and habitat quality, carbon storage, etc., thus, leaving the decision maker with a multi-criteria problem. The present study demonstrates how partial-order methodology constitutes an advantageous tool for rating/ranking land use that takes trade-offs into account. It is demonstrated that not only the optimal choice of area, on an average basis, e.g., for crop production, is disclosed, but also the relative importance of the included indicators (production gains, ecosystem losses). A short introduction is given, applying data from a recent Chinese study looking for the optimal monoculture as a function of ecosystem tradeoffs. A more elaborate system applying data from the esgame was used, disclosing the most beneficial area for crop production and for ranching, as well as the relative indicators’ importance. The study further demonstrates that a single composite indicator obtained by simple aggregation of indicator values as a ranking tool may lead to a result where gains are optimized; however, this comes at the expense of the environment. Full article

Recently, there has been enormous development due to advancements in technology. Industries and enterprises are moving towards a digital system, and the oil and gas industries are no exception. There are several threats and risks in digital systems, which are controlled through cyber-security. For the first time in the theory of fuzzy sets, this research analyzes the relationships between cyber-security and cyber-crimes in the oil and gas sectors. The novel concepts of complex intuitionistic fuzzy relations (CIFRs) are introduced. Moreover, the types of CIFRs are defined and their properties are discussed. In addition, an application is presented that uses the Hasse diagram to make a decision regarding the most suitable cyber-security techniques to implement in an industry. Furthermore, the omnipotence of the proposed methods is explained by a comparative study. Full article

Technology is rapidly advancing and every aspect of life is being digitalized. Since technology has made life much better and easier, so organizations, such as businesses, industries, companies and educational institutes, etc., are using it. Despite the many benefits of technology, several risks and serious threats, called cyberattacks, are associated with it. The method of neutralizing these cyberattacks is known as cybersecurity. Sometimes, there are uncertainties in recognizing a cyberattack and nullifying its effects using righteous cybersecurity. For that reason, this article introduces interval-valued complex intuitionistic fuzzy relations (IVCIFRs). For the first time in the theory of fuzzy sets, we investigated the relationships among different types of cybersecurity and the sources of cyberattacks. Moreover, the Hasse diagram for the interval-valued complex intuitionistic partial order set and relation is defined. The concepts of the Hasse diagram are used to inspect different cybersecurity techniques and practices. Then, using the properties of Hasse diagrams, the most beneficial technique is identified. Furthermore, the best possible selection of types of cybersecurity is made after putting some restrictions on the selection. Lastly, the advantages of the proposed methods are illuminated through comparison tests. Full article

The inequality within the 27 European member states has been studied. Six indicators proclaimed by Eurostat to be the main indicators charactere the countries: (i) the relative median at-risk-of-poverty gap, (ii) the income distribution, (iii) the income share of the bottom 40% of the population, (iv) the purchasing power adjusted GDP per capita, (v) the adjusted gross disposable income of households per capita and (vi) the asylum applications by state of procedure. The resulting multi-indicator system was analyzed applying partial ordering methodology, i.e., including all indicators simultaneously without any pretreatment. The degree of inequality was studied for the years 2010, 2015 and 2019. The EU member states were partially ordered and ranked. For all three years Luxembourg, The Netherlands, Austria, and Finland are found to be highly ranked, i.e., having rather low inequality. Bulgaria and Romania are, on the other hand, for all three years ranked low, with the highest degree of inequality. Excluding the asylum indicator, the risk-poverty-gap and the adjusted gross disposable income were found as the most important indicators. If, however, the asylum application is included, this indicator turns out as the most important for the mutual ranking of the countries. A set of additional indicators was studied disclosing the educational aspect as of major importance to achieve equality. Special partial ordering tools were applied to study the role of the single indicators, e.g., in relation to elucidate the incomparability of some countries to all other countries within the union. Full article