Theory of Computing Systems \/ Mathematical Systems Theory最新文献

{"title":"Trend Significance Levels of Rain Onset and Cessation and Lengths of the Wet and Dry Seasons in Epe, Lagos State, Nigeria","authors":"A. A. Alli, O. Omofunmi","doi":"10.7454/MST.V25I2.3953","DOIUrl":"https://doi.org/10.7454/MST.V25I2.3953","url":null,"abstract":"This study aims to reduce crop failure resulting from a dry spell, which is the first occurrence of unsustainable rainfall that deceives farmers into planting. Thus, trends need to be tested using hypothesis, kurtosis, and other statistics to analyze the risks associated with unstable planting calendars and their possible mitigation strategies. The daily rainfall data from 1982 to 2018 were obtained from the archive of NASA/POWER SRB/FLASH, and the research location is Epe, Lagos State, Nigeria, which lies at latitude 6.585° N and longitude 3.962° E. Microsoft Excel was used to perform the tests. Results show that the null hypothesis of no trend in the distribution was rejected on the basis of the fact that the probability value (p = 0.00) is less than the significance level (α = 0.05). The mean onset and cessation dates are March 27 and October 18, with skewness values of −0.63 and 11.02, respectively. Rain onset and cessation that occur from February 12 to April 27 and from September 28 to November 28, respectively, are safe with low risks of dry spell. Moreover, drought and dry spell were most probable in years that experienced a shorter length of wet season than dry season.","PeriodicalId":22842,"journal":{"name":"Theory of Computing Systems \\/ Mathematical Systems Theory","volume":"46 1","pages":"79-83"},"PeriodicalIF":0.0,"publicationDate":"2021-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86691761","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of drying method on compressive strength of straw-based thermal insulations","authors":"Olivér Fenyvesi, Dániel Csanády","doi":"10.31448/MSTJ.03.01.2020.108-116","DOIUrl":"https://doi.org/10.31448/MSTJ.03.01.2020.108-116","url":null,"abstract":"Most of the thermal insulations in the construction industry market based on fossil raw material or need a huge amount of production energy. Nowadays, sustainable thermal insulation products are more popular, and the demand for these products on the market is increasing. Some of them reach the main material properties of artificial ones but usually not all. Today the reaction to fire is another big challenge in this field. In many cases, producers use chemicals that can increase fire resistance, but on the other hand, increase the environmental impact of insulations too. It is also hard to find a binder which provides proper mechanical parameters and durability and is environmentally friendly too. During our scientific research on environmentally friendly thermal insulation materials, which is running for 4 years, we found that silicate-based adhesives meet many of these criteria mentioned above. In this article, the mechanical properties of straw-based insulation bonded with silicate binder were investigated. The effect of conventional and microwave drying on compressive strength were compared to found the optimal hardening process of binders. During the experiments, straw was applied in a natural state, natural stem length distribution and without microstructure and surface modification. The used binder is a simple silicate-based binder (potassium silicate) without any modification agent. Conventional drying needs a longer time, and during it, many cracks form in the early age of the hardened binder. It is because of shrinkage and the differences in the rigidity of the binder along its cross-section. Besides, the straw stems swell when exposed to moisture (from binder), and after drying they shrink, which decreases the quality of the bond between stems and binder. The microwave drying evenly heats the various points of the specimen, so it is not generated such big differences in shrinkage. The contact between stems and binder are also better. Due to these effects, the microwave dried specimens reached the limit required for step resistance, and they had three-time higher average compressive strength than we got by the conventional drying of the same raw material.","PeriodicalId":22842,"journal":{"name":"Theory of Computing Systems \\/ Mathematical Systems Theory","volume":"2 1","pages":"108-116"},"PeriodicalIF":0.0,"publicationDate":"2021-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87374989","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"CONTENT MANAGEMENT SYSTEM FOR SCHOOL INFORMATION WEBSITE","authors":"M. Yani, Fahrul Rizal, Muhammad Reza Padillah","doi":"10.47002/MST.V1I1.203","DOIUrl":"https://doi.org/10.47002/MST.V1I1.203","url":null,"abstract":"The website is one of the digital information media used by schools to display their profiles so that they can be known by the public. Some SMP Negeri in Kota Samarinda do not yet have a website as a media or school information center. This could be due to difficulties in creating and on the website of each school. From these problems, in this study researchers innovated to create a Content Management System (CMS) for school websites, especially at SMP Negeri 29 Samarinda. Laravel PHP framework is used with the system development method is the Waterfall method.","PeriodicalId":22842,"journal":{"name":"Theory of Computing Systems \\/ Mathematical Systems Theory","volume":"31 1","pages":"28-35"},"PeriodicalIF":0.0,"publicationDate":"2021-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74082218","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Static analysis of bond between prestressing strand and UHPC exposed to elevated temperatures","authors":"D. Čítek, J. Čech, P. Pokorný, J. Kolísko","doi":"10.31448/MSTJ.03.01.2020.102-107","DOIUrl":"https://doi.org/10.31448/MSTJ.03.01.2020.102-107","url":null,"abstract":"This article deals with the numerical analysis of the bond of a prestressing strand with UHPC heated to elevated temperatures and subsequently cooled. Numerical analysis was performed with experimentally determined material properties of UHPC at a reference temperature of 20 °C and further after heating to temperatures of 200, 400 and 600 °C and subsequent annealing to normal temperature. The resulting deflection depending on the pulling force from the numerical analysis were compared with the experimental results. The results are used to configure the cement composite model for more demanding simulations of structures and load cases.","PeriodicalId":22842,"journal":{"name":"Theory of Computing Systems \\/ Mathematical Systems Theory","volume":"20 1","pages":"102-107"},"PeriodicalIF":0.0,"publicationDate":"2021-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86516344","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Buckling length of reinforced concrete columns in non-sway constructions","authors":"P. Dolny, P. Wilinski, Krzysztofiń Kamski","doi":"10.31448/MSTJ.03.01.2020.94-101","DOIUrl":"https://doi.org/10.31448/MSTJ.03.01.2020.94-101","url":null,"abstract":"The paper presents a comparison of methods of determining the buckling length of reinforced concrete columns in non-sway frames. The comparison was made on the basis of guidelines issued by Poland some EU countries, USA and India. Differences in approaches and values of buckling length coefficients of columns calculated according to these guidelines are shown. An example of the calculation of column buckling length coefficients on selected multi-span, multi-storey non-sway frames is given.","PeriodicalId":22842,"journal":{"name":"Theory of Computing Systems \\/ Mathematical Systems Theory","volume":"25 1","pages":"94-101"},"PeriodicalIF":0.0,"publicationDate":"2021-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73493434","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Redesign of Product Packaging with Kansei Engineering: Empirical Study on Small-medium Enterprises in Indonesia","authors":"A. Suzianti, A. Aldianto","doi":"10.7454/mst.v24i2.2990","DOIUrl":"https://doi.org/10.7454/mst.v24i2.2990","url":null,"abstract":"Small-medium enterprises (SMEs) in Indonesia have been proven to be one of the important pillars of the national economy. Unfortunately, some problems hinder their development, and one of the critical problems is the quality of product packaging. The packages of SME products are considered poor, dirty, and unattractive. Packaging problem is one of the factors why consumers are less interested in buying and why SME products always lose in the competition with other products. This study discusses how to employ Kansei engineering to design better SME product packaging with a focus on psychological (affective) aspects. This research concludes that there are four components that represent consumers’ desires: Attractiveness, Robustness, Handy & Green, and Lightness. The final result of this research is the creation of four new designs for a product package that satisfies each of the above components.","PeriodicalId":22842,"journal":{"name":"Theory of Computing Systems \\/ Mathematical Systems Theory","volume":"11 1","pages":"65-71"},"PeriodicalIF":0.0,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88140696","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of Landfill Leachates on Some Water Quality Indicators of Selected Surface Water and Groundwater at Ilokun, Ado-Ekiti, Nigeria","authors":"O. Omofunmi, A. Satimehin, A. Oloye, Okwunna M Umego","doi":"10.7454/mst.v24i2.3881","DOIUrl":"https://doi.org/10.7454/mst.v24i2.3881","url":null,"abstract":"This study was conducted to examine the impact of dumpsites on the quality of groundwater and surface water. The water samples and leachates were collected from dumpsites in respective zones. The physicochemical properties of the samples were examined and determined in accordance with the standards of the American Public Health Association. Results indicated that the groundwater and surface water that are close to the dumpsites have an electrical conductivity of 385 and 245 Sd/cm, total dissolved solids of 168 and 128 mg/L, a turbidity of 4.6 and 22 NTU, a total alkalinity of 103 and 50 mg/L, a total hardness of 120 and 80 mg/L, Ca concentration of 44 and 14 mg/L, Mg concentration of 0.2 and 15 mg/L, SO4 concentration of 4 and 42 mg/L, Cl concentration of 38 and 16 mg/L, and NO3 concentration of 6 and 8 mg/L, respectively. Moreover, the water near the dumpsites had higher elevated physicochemical properties compared with those far from the dumpsites; in addition, they were significantly different (p ≥ 0.05). Hence, the closer the groundwater and surface water to the dumpsite, the greater the negative impact on the physicochemical properties of water. The pH concentration in leachate serves as an indicator for the age and mineralization status of dumpsites, and it influences the other chemical properties of the leachate. Furthermore, the pH concentration in leachate is inversely proportional to the concentration of Ca, Mg, and SO4 in the study area.","PeriodicalId":22842,"journal":{"name":"Theory of Computing Systems \\/ Mathematical Systems Theory","volume":"10 1","pages":"72-78"},"PeriodicalIF":0.0,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80063615","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of PVDF-CA Ratio on Electrospun Membrane for Water–Oil Filtration Application","authors":"M. W. Alias, I. I. Misnon, R. Jose","doi":"10.7454/mst.v24i2.3845","DOIUrl":"https://doi.org/10.7454/mst.v24i2.3845","url":null,"abstract":"Oil spillage and generation of industrial water–oil wastewater mixture ignite a focus on filtration technology. Electrospinning technique provides a versatile route in producing tunable diameter and pores in nanofiber filtration membrane development. In this work, polyvinylidene difluoride (PVDF) and cellulose acetate (CA) electrospun membrane at different concentration ratios were synthesized for water–oil filtration application. The polymeric solutions were characterized using viscometer and conductivity testing, whereas the membranes were analyzed using contact angle, tensile test, scanning electron microscopy (SEM), and filtration testing of oil (dichloromethane). Conductivity test showed a decreased conductivity along with decrement of CA ratio in the polymeric solution. The viscosity results showed a rising trend along with the increment of CA in the polymeric solution along with the decrement of PVDF ratio. SEM result showed that all membranes had a fiber diameter range of 210–485 nm and pore size range of 235–856 nm. The tensile test showed a decreasing tensile strength as the ratio of PVDF in the electrospun membrane decreased. The membrane with PVDF-to-CA ratio of 90:10 showed optimum performance for water–oil filtration with a flux of 14,111 Lm −2 h −1 and oil recovery of 94%.","PeriodicalId":22842,"journal":{"name":"Theory of Computing Systems \\/ Mathematical Systems Theory","volume":"110 1","pages":"87-92"},"PeriodicalIF":0.0,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87612291","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Microstrip Filters: A Review of Different Filter Designs Used in Ultrawide Band Technology","authors":"Hussain Bohra, G. Prajapati","doi":"10.7454/mst.v24i2.3903","DOIUrl":"https://doi.org/10.7454/mst.v24i2.3903","url":null,"abstract":"In this study, optimization techniques applied in designing microstrip bandpass ultra-wideband (UWB) filters are presented. Optimization based on various defected ground structure techniques, resonator designs, and type of dielectric materials is discussed. Microstrip bandpass filters implemented at UWB frequency bands used in wireless communication systems have key features to control frequency response in passband and stopband. Optimization techniques are studied to attain optimum performance of bandpass microstrip filters to ensure minimum insertion loss, high selectivity, compactness, sharp transitions at cut-off frequencies, high return loss, and excellent linearity. Extensive study shows that proper selection of fabrication techniques and type of material optimizes the performance of microstrip filter design, thereby increasing its practicability for emerging wireless communication systems.","PeriodicalId":22842,"journal":{"name":"Theory of Computing Systems \\/ Mathematical Systems Theory","volume":"167 1","pages":"79-86"},"PeriodicalIF":0.0,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73956765","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Performance-Shaping Factors of Personnel Performing Evacuation and Escape on Offshore Installations in Tropical","authors":"N. Norazahar, Nur Azizah Arryanie Morshidi, A. Ahmad, Wijayanuddin Mohd Ali","doi":"10.7454/mst.v24i2.3756","DOIUrl":"https://doi.org/10.7454/mst.v24i2.3756","url":null,"abstract":"Performance-shaping factors (PSFs) are used to address the strengths and weaknesses of workers performing escape and evacuation activities. These PSFs are time, environmental factors as stressors, complexity of activities, experiences and training, interaction between workers and emergency equipment, workers’ physical conditions, and procedures. This paper presents a survey work on fitness for the duty of workers performing basic offshore survival and emergency response training. The training provides credible scenarios of escape and evacuation in case of an emergency of offshore installations in tropical waters. The survey is conducted among participants of the tropical basic offshore safety induction & emergency training with emergency breathing system. Sixteen participants of the training voluntarily answered the set of questionnaires. The survey work addresses the fitness for duty among workers performing escape and evacuation on offshore installations. Survey results indicate that workers must have good physical conditions and mental fitness in order to accomplish the escape and evacuation activities.","PeriodicalId":22842,"journal":{"name":"Theory of Computing Systems \\/ Mathematical Systems Theory","volume":"33 1","pages":"93-98"},"PeriodicalIF":0.0,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89139967","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}