Incremental clickstream pattern mining with search boundaries

Recently, there has been a growing interest in sequential pattern mining in data mining, with a particular focus on clickstream pattern mining. These areas hold the potential for discovering valuable patterns. However, traditional mining algorithms in these domains often assume that databases are static, simplifying the mining process. In reality, databases are updated incrementally over time, partially rendering a portion of the previous results invalid. This necessitates rerunning algorithms on updated databases to obtain accurate frequent patterns. As database size increases, this approach can become time-consuming and affect performance. To tackle this issue, we propose PSB-CUP to mine frequent clickstream patterns in an incremental update manner. PSB-CUP employs the concept of search borders to reduce the search space and the information retained in memory. Furthermore, an IDList generation method called “partial imbalance join” was proposed to reconstruct possibly missing information during the incremental process. This join method, however, requires more extra information to be cached in exchange for speed. We then improve this technique by introducing “recursive imbalance join”, removing the need for extra cached data in the PSB-CUP + algorithm. The experimental results show that our proposed algorithms are efficient for incremental clickstream pattern mining.Faculty of Applied Informatics, Tomas Bata University in Zlin; Internal Grant Agency of Tomas Bata University, (IGA/CebiaTech/2023/004)Internal Grant Agency of Tomas Bata University [IGA/CebiaTech/2023/004

DFT study of water on graphene: Synergistic effect of multilayer p-doping

Recent experiments related to a study concerning the adsorption of water on graphene have demonstrated the p-doping of graphene, although most of the ab initio calculations predict nearly zero doping. To shed more light on this problem, we have carried out van der Waals density functional theory calculations of water on graphene for both individual water molecules and continuous water layers with coverage ranging from one to eight monolayers. Furthermore, we have paid attention to the influence of the water molecule orientation toward graphene on its doping properties. In this article, we present the results of the band structure and the Bader charge analysis, showing the p-doping of graphene can be synergistically enhanced by putting 4-8 layers of an ice-like water structure on graphene having the water molecules oriented with oxygen atoms toward graphene.AMISPEC, (TE01020233); INCHAR, (FW03010504); Technology Agency of the Czech Republic, TACR; Ministerstvo Školství, Mládeže a Tělovýchovy, MŠMT; Grantová Agentura České Republiky, GA ČR, (23-07617S); Vysoké Učení Technické v Brně, BUT, (FSI-S-23-8324)Grant Agency of the Czech Republic; Ministry of Education, Youth and Sports from the Large Infrastructures for Research; Technology Agency of the Czech Republic [TE01020233]; Specific Research grant of the Brno University of Technology [FSI-S-23-8324]; [23-07617S]Grant Agency of the Czech Republic; Ministry of Education, Youth and Sports from the Large Infrastructures for Research; Technology Agency of the Czech Republic [TE01020233]; Specific Research grant of the Brno University of Technology [FSI-S-23-8324]; [23-07617S

Interlinking dynamics of natural resources, financial development, industrialization, and energy intensity: Implications for natural resources policy in emerging seven countries

The study examines the intricate relationship between energy poverty, natural resources rents, energy intensity, financial development, and industrialization, with CO2 emissions in the E−7 countries from 1996 to 2021. This study utilizes a nonparametric econometric approach known as the method of moments quantile regression. The findings highlight significant associations among these variables. Higher energy poverty levels are linked to increased CO2 emissions, indicating a correlation between energy poverty and carbon emissions. Likewise, higher energy intensity, reflecting lower energy efficiency, contributes to greater carbon emissions. Furthermore, reliance on natural resources for economic development is positively associated with CO2 emissions, suggesting potential environmental deterioration. The financial development shows a positive association with CO2 emissions, suggesting that increased financial resources may lead to higher carbon emissions. However, this relationship diminishes at higher levels of financial development, indicating a potential decoupling of financial progress from carbon emissions. Industrialization and natural resources display a positive relationship with CO2 emissions, highlighting the contribution of industrialization to carbon emissions. Policymakers are urged to prioritize energy efficiency promotion, facilitate the transition to renewable energy sources, and encourage sustainable industrial practices. Integrating innovation activities that prioritize green technologies and sustainable development can effectively reduce CO2 emissions while supporting economic growth. These findings hold crucial implications for policymakers in the E−7 countries, emphasizing the need for sustainable development and environmental stewardship. Striking a balance between economic growth and environmental preservation is essential for a sustainable future in the E−7 countries

The implication of PMMA molecular weight on compatibility of SAN/PMMA blends containing GO-g-PMMA hybrid compatibilizers

The molecular weight of a polymer is one of the most important factors defining material properties and performance. Within the current study, poly(styrene-co-acrylonitrile)/poly(methyl methacrylate) (SAN/PMMA) blends containing hybrid particles of graphene oxide-g-poly(methyl methacrylate) (GO-g-PMMA) were designed so that the molecular weight of the PMMA chains tethered on the GO particles was correlated with the molecular weight of the PMMA matrix. Hybrid particles were prepared using surface-initiated atom transfer radical polymerization (ATRP). The number average molecular weight of the matrix PMMA was Mn = 20,100 or 130,900 g/mol, while in the case of hybrids it was Mn = 5600, 27,300 or 191,600 g/mol. Two blend compositions were investigated: SAN/PMMA= 70/30 and 90/10 wt/wt, and the content of GO-g-PMMA was 1 wt%. Based on rheological studies it was demonstrated that higher molecular weights of the matrix PMMA promoted the compatibility of SAN/PMMA due to the similar viscosity of both blend components. Furthermore, the length of the PMMA chains grafted to the GO influenced the viscoelastic response of the material, resulting in different relaxation behavior as confirmed by mean relaxation times calculated from Cole-Cole plots. In addition, the effect of neat GO and GO-g-PMMA particles on the blend morphology and size distribution of PMMA droplets was discussed based on rheology and TEM analyses.DKRVO, (RP/CPS/2022/003); Doctoral Candidate in the Interdisciplinary Doctoral School at the Lodz University of Technology; Ministerstvo Školství, Mládeže a Tělovýchovy, MŠM

Development of a contact glass-break detector for the highest security level

The main object of this research was to develop a security system to evaluate the intrusion into an object through a glass pane. More specifically, this study deals with sensing and evaluating signals from a contact glass-break detector, which is part of an intruder alarm system. Each alarm detector in an alarm system must accomplish certain security level requirements that strictly describe the requirements for the area of use and the detector’s reliability. To date, no contact glass-break detector has been developed and fully tested to meet the stringent requirements of the highest security level. A contact glass-break detector was developed whose main part is an accelerometer that transmits signals from the glass pane. These signals were evaluated according to the developed methodology. It was verified that the proposed system can distinguish at the highest security level between false alarms and situations where the building has been intruded.Crime Scenario Reconstruction Within Virtual Reality, (MV-73045-3/OBVV-2021); Internal Grant Agency of Tomas Bata University, (IGA/CebiaTech/2023/001); Ministerstvo Školství, Mládeže a Tělovýchovy, MŠMT, (LO1303, MSMT-7778/2014); European Regional Development Fund, ERDF, (CEBIA-Tech ED2.1.00/03.0089, VJ02010043)Ministry of Education, Youth and Sports of the Czech Republic within the National Sustainability Program Projec

Recent advances in nanocellulose-based two-dimensional nanostructured membranes for sustainable water purification: A review

Nanocellulose (NC), a one-dimensional nanomaterial, is considered a sustainable material for water and wastewater purification because of its promising hydrophilic surface and mechanical characteristics. In this regard, nanostructured membranes comprising NC and two-dimensional (2D) nanomaterials emerged as advanced membranes for efficient and sustainable water purification. This article critically reviews the recent progress on NC-2D nanostructured membranes for water and wastewater treatment. The review highlights the main techniques employed to fabricate NC-2D nanostructured membranes. The physicochemical properties, including hydrophilicity, percent porosity, surface roughness, structure, and mechanical and thermal stability, are summarized. The key performance indicators such as permeability, rejection, long operation stability, antifouling, and interaction mechanisms are thoroughly discussed to evaluate the role of NC and 2D nanomaterials. Finally, summary points and future development work are highlighted to overcome the challenges for potential practical applications. This review contributes to the design and development of advanced membranes to solve growing water pollution concerns in a sustainable manner.NCBP, (QUCP-CAM23/24-153); National Capacity Building Program; Qatar University, QUQatar University [QUCP-CAM23/24-153

Analysis of stylistic and grammatical errors in PhD students' research paper manuscripts

The ability to publish research papers is a must for scientists nowadays. Ideally, at the very beginning of their career, young researchers, PhD students, should be instructed in writing research papers and should get feedback on their texts. In this study, the first manuscripts from 22 doctoral students, non-native English speakers, 223 pages were analysed for errors in grammar, spelling, punctuation, and style. For each type of error and each student, the average per page was calculated. The most frequent errors were identified in using articles, formal features, missing information, and the use of inappropriate words. Individual students showed significantly different levels, which reflected their previous language training and the approach (responsibility) to completing the task. The results will be used to modify the course in Academic Writing (more attention paid to the most frequent errors) and individual work with students

Assessing the factors impacting shipping container dwell time: A multi-port optimization study

Ocean transportation is the most preferred mode of transportation that represents a significant role in the global trade. Ocean transportation comprises around 80% of the aggregate worldwide cargo volume. This research paper focused on evaluating the factors that influence the dwell time of the shipping containers. Dwell time is one of the important port performance parameters which evaluates the time spent by the container in a port. In this research, the data from the fourteen major ports was collected and analysed across the variables, such as cycle, size, mode, status, delivery and tracking technology for evaluating the variation in container dwell time. OLS regression method (Ordinary least squares) along with independent sample T test was adopted for the analysis of 2.8 million container data entries utilizing python for big data analysis and SPSS. For the top three ports with lowest RMSE (Root mean square error), Port A – 15.6 %, Port G – 15.7 % and Port L – 15.86 %, a qualitative study was performed to identify the reasons for the variation in dwell time. The major reasons identified included free days period, trans-shipment port, high rail frequency, industrial hubs in the vicinity of the ports for lower dwell time. A qualitative research framework was presented as the research outcomes and reasons for variations in a multiport study.FaME TBU, (IGA/FaME/2022/005

Towards anomally detection using stationary and non-stationary signal analysis

This paper focuses on demonstration of an enhanced model for investigating data signals features, i.e., whether the given signal has stationary or non-stationary features. The accurate detection of the features of signals is crucial for the right directions towards methodology of further preprocessing to perform data analysis of the data signal, specifically in the tasks of finding anomalies in the given signal and big data environment. A problem often encountered is the exact determination of the occurrence of stationary or non-stationary data signal features in data processing. Within this research paper, the mathematical foundations of data signal processing are described. Based on the mathematical model of the input signal processing, an improved workflow using the enhanced statistical KPSS test and autocorrelation function (graphical) analysis is demonstrated here, to confirm the accuracy and usability of selected methodology. The alternative approach described here leads to a much lower computational effort and the achievement of accurate identification of signal features in big data environment for possible deployment of A.I. or machine learning anomaly detection pipeline. The obtained dataset and model are based on the real environment and measured signals in the production process of machine tools in company Tajmac-ZPS Zlin

Detection of NH3 gas using CrVO4 nanoparticles

Nanostructured chromium orthovanadate with an average particle size of 65 nm was prepared by the co-precipitation technique for the chemiresistive sensor. The morphology and particle size distribution of CrVO4 nanoparticles were examined by SEM and TEM. According to XRD, most of the prepared CrVO4 material (crystallites) has a monoclinic structure belonging to the space group C2/m. XPS and UV-Vis absorbance measurements provided additional information on the main phase and the surface. The material has shown reasonable selectivity towards the NH3 gas. The as-prepared CrVO4 nanostructures exhibit a maximum relative response of 32% to 50 ppm NH3. The identical dynamic response profiles during the sequential injections of 50 ppm NH3 evinced the repeatability of the sensor. The limit of detection (LOD) value of the sensor was estimated ca 0.7 ppm using relative response values towards a wide range of NH3 concentrations from 10 ppm to 100 ppm. The sensing mechanism was expressed in terms of the surface band bending phenomenon caused by the adsorption and desorption of the ammonia. The best sensor performance was achieved at 330 °C, where the effects of humidity and moisture can be neglected. The results confirmed that the CrVO4 nanomaterial has the potential to fabricate an affordable, easy-to-make, and reliable gas sensor for NH3 gas.DKRVO, (RP/CPS/2022/007); European Union´s Horizon 2020 research and innovation programme, (739566); Ministerstvo Školství, Mládeže a Tělovýchovy, MŠMT; Istanbul Üniversitesi, (FYL-2021-38266); Agentúra na Podporu Výskumu a Vývoja, APVV; Vedecká Grantová Agentúra MŠVVaŠ SR a SAV, VEGA, (1/0844/21); Universität zu Köln, UoC; Univerzita Tomáše Bati ve Zlíně, UTB, (IGA/CPS/2022/002, IGA/CPS/2023/006)Ministry of Education, Youth and Sports of the Czech Republic - DKRVO [RP/CPS/2022/007]; European Union's Horizon 2020 research and innovation programme [739566]; Internal grant agency of Tomas Bata University in Zlin [IGA/CPS/2022/002, IGA/CPS/2023/006]; Scientific Research Projects Coordination Unit of Istanbul University [FYL-2021-38266]; Slovak Research and Development Agency [VEGA 1/0844/21]; University of Cologn