Journal of Mathematical Techniques and Computational Mathematics最新文献_第5页

Species can base their impression of themselves on the number of sensory neurons they have and their IUCN level 物种对自己的印象可以建立在它们拥有的感觉神经元数量和它们的IUCN水平上

Journal of Mathematical Techniques and Computational Mathematics Pub Date : 2021-10-21 DOI: 10.21203/rs.3.rs-993231/v1

Aaron T. Goetz

引用次数: 0

Fired Heater Simulation, Modelling and Optimization 燃烧加热器仿真、建模与优化

Journal of Mathematical Techniques and Computational Mathematics Pub Date : 2021-09-01 DOI: 10.21203/rs.3.rs-847461/v1

Taj Alasfia M brakat, Mahmoud Hassan

{"title":"Fired Heater Simulation, Modelling and Optimization","authors":"Taj Alasfia M brakat, Mahmoud Hassan","doi":"10.21203/rs.3.rs-847461/v1","DOIUrl":"https://doi.org/10.21203/rs.3.rs-847461/v1","url":null,"abstract":"\u0000 In this study a dynamic model Simulation was carried out using ASPEN HYSY for industrial refinery fired heater, PID controller was applied to control the flue gas exit temperature. the simulation shows perfect agreement with the datasheet of the furnace. It was found that Increasing the number of the tube rows in convection bank from 2 to 3 allows us to recover approximately 5% of the overall efficiency, hence the duty furnace has increased from 65.9MW to 68.1MW and the fuel flow in like manner has increased from 5597kg/h to 5807kg/h moreover Adding more rows has a reverse return as we start to notice increase on the flue gas temperature. Furthermore, sensitivity analysis was conducted with HYSYS to determine one of the most important parameters that affect the performance of the heater based on the data generated from the simulation. MATLAB code was generated for efficiency calculation and for parameter manipulation, the code was designed to be flexible as possible, user will just need to replace the nominal fuel and air characteristics. for gaining optimum furnace operation the heat transfer inside the furnace was studied, and the results were compared with previous research involving furnace analysis to validate models, the heat transfer coefficient is determined by analysis of conductive heat transfer through the boundary layer. well-stirred model was used for mathematical model calculations and for optimization of furnace operation, the models were validated with ASPEN Exchanger Design and Rating(EDR) alongside ASPEN HYSYS","PeriodicalId":437292,"journal":{"name":"Journal of Mathematical Techniques and Computational Mathematics","volume":"95 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121406090","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}

引用次数: 1

New Mobility Model for Mobile and Geographic Cross-layer Architecture for Mobile IoT Networks 移动物联网网络的移动和地理跨层架构的新移动性模型

Journal of Mathematical Techniques and Computational Mathematics Pub Date : 2021-06-18 DOI: 10.21203/rs.3.rs-456526/v1

Ridouane El Mezouary, Abdelmoghit Souissi

{"title":"New Mobility Model for Mobile and Geographic Cross-layer Architecture for Mobile IoT Networks","authors":"Ridouane El Mezouary, Abdelmoghit Souissi","doi":"10.21203/rs.3.rs-456526/v1","DOIUrl":"https://doi.org/10.21203/rs.3.rs-456526/v1","url":null,"abstract":"\u0000 In this article, we propose a new mobility model, for a mobile and geographic cross-layer architecture. This cross-layer architecture allows service differentiation between real-time and best-effort traffic, for a mobile internet of things ( IoT ) network. We present a mathematical model, which works on the parameters of the MAC layer and the network layer. The mathematical model makes it possible to calculate the throughput between a source object and a destination object (gateway), under conditions of stable queues. We use the positional (geographic) information in the mathematical model of the proposed cross-layer architecture, to study the impact of mobility on the performance of the proposed mathematical model. The proposed mobility model defines two time intervals, the first interval for communication (transmission and reception of data without mobility at the same time), and the second time interval for the mobility of objects of the IoT network (without communication at the same time). The results show that the calculated throughput depends on the position of the objects, as well as the probability of transmission. Finally, we study the effect of distance and speed on the performance of the proposed cross-layer architecture.","PeriodicalId":437292,"journal":{"name":"Journal of Mathematical Techniques and Computational Mathematics","volume":"289 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117048005","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}

引用次数: 0

Pre–service and In-service primary teachers’ generic and subject-specific skills On Geometric understanding of symmetry: A case study 职前与在职小学教师一般技能与专业技能:对称几何理解之个案研究

Journal of Mathematical Techniques and Computational Mathematics Pub Date : 2021-01-29 DOI: 10.21203/rs.3.rs-162682/v1

S. Mafakheri

{"title":"Pre–service and In-service primary teachers’ generic and subject-specific skills On Geometric understanding of symmetry: A case study","authors":"S. Mafakheri","doi":"10.21203/rs.3.rs-162682/v1","DOIUrl":"https://doi.org/10.21203/rs.3.rs-162682/v1","url":null,"abstract":"\u0000 According to the curricula all over the world symmetry plays an important role in the teaching geometry at primary levels. Geometry is one of topics that have the most problematic content knowledge for the prospective primary teachers. This paper studies the understanding of the symmetry of shapes among pre-service and in-service teachers to find out their visual perception of the geometric shapes symmetry and the symmetry axis. The aim is to create a symmetrical pattern with symmetry axis of the shapes. Evidence that only content-oriented professional development coursework taken by primary school math teachers appears effective, suggests that relatively more resources ought to be put into content focused training for teachers and that changes are warranted at the elementary level and in pedagogical in-service training generally. The primary teacher needs to be able to modify some proposed problems in order to get a richer mathematical activity, being aware of their mathematical benefits. It should be part of growing the capacity of analyzing didactically the mathematics activity.","PeriodicalId":437292,"journal":{"name":"Journal of Mathematical Techniques and Computational Mathematics","volume":"52 2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115101574","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}

引用次数: 0

Supply versus demand of health care facilities in a competitive context: Case of tuberculosis care in Douala-Cameroon 竞争环境下卫生保健设施的供求关系:杜阿拉-喀麦隆结核病护理案例

Journal of Mathematical Techniques and Computational Mathematics Pub Date : 2020-10-12 DOI: 10.21203/rs.3.rs-51754/v1

A. N. Yakam, Prisca Fosso Koncy, Njocke Martin, Bowong Samuel, F. Louis, Noeske Jürgen

{"title":"Supply versus demand of health care facilities in a competitive context: Case of tuberculosis care in Douala-Cameroon","authors":"A. N. Yakam, Prisca Fosso Koncy, Njocke Martin, Bowong Samuel, F. Louis, Noeske Jürgen","doi":"10.21203/rs.3.rs-51754/v1","DOIUrl":"https://doi.org/10.21203/rs.3.rs-51754/v1","url":null,"abstract":"\u0000 Background\u0000\u0000Identifying the socio-economic factors associated with the supply and the demand of health facilities (HF), can contribute to the decision-making of the creation of the HF. This study aims to contribute to this issue, in the competitive context of the tuberculosis diagnosis and treatment centres (DTC), and to describe the spatial distribution of the residence of TB patients and DTC, to understand the DTC attendance’ rate in the city of Douala, Cameroon.\u0000Methods\u0000\u0000The Spatial analysis was performed to access the spatial-economic model hiding behind the distribution of the “observed” number of patients attending the DTCs compared to the “expected” number. Multivariate analysis using logistic regression and the analysis of variance were used to identify the factors associated to the demand and supply of DTCs respectively.\u0000Results\u0000\u0000The decentralization policy advocated by the national program against tuberculosis (NTP) is not always followed by the patients: The “expected” and the “observed” number of patients in DTCs are not correlated. The attendance of DTCs in Douala is in accordance with the spatial-economic theory models of Salop and Hotelling, which is an artefact. Patients seeking treatment in DTCs closer to their residence are mainly women and patients from relative poor households, while attendance of DTC was associated with the quality of service and the level of the HF.\u0000Conclusion\u0000\u0000Attendance HF is dictated by the spatial-economic theory models. The policy of creating HF for TB is not followed by patients in competitive context. Attendance of HF by TB patients is associated with socioeconomic factors;","PeriodicalId":437292,"journal":{"name":"Journal of Mathematical Techniques and Computational Mathematics","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115853119","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}

引用次数: 0

The Past, Present and the Futuristic Earth-Moon Orbital-Globe Dynamics - and its habitability 过去，现在和未来的地球-月球轨道-地球动力学-及其可居住性

Journal of Mathematical Techniques and Computational Mathematics Pub Date : 2020-08-03 DOI: 10.1002/essoar.10504140.1

B. Sharma

{"title":"The Past, Present and the Futuristic Earth-Moon Orbital-Globe Dynamics - and its habitability","authors":"B. Sharma","doi":"10.1002/essoar.10504140.1","DOIUrl":"https://doi.org/10.1002/essoar.10504140.1","url":null,"abstract":"Using Advanced Kinematic Model (AKM), the unfolding of Earth’s eco-system under the influence of the evolving tidally interacting Earth-Moon System (E-M system) is studied. E-M system is born 4.467Gy ago at inner geo-synchronous orbit (aG1 = 15,000Km) which is a Total Energy Maxima Hill Top (+4.18x10^30J). E-M system tidally evolves to its final interlocking orbit in 97Gy from NOW at outer geo-synchronous orbit (aG2 = 534,590.6Km) which is Total Energy Minima Valley (- 2.64x10^28J). Tidal evolution is accompanied with synchronization and circularization of Moon’s orbit but co-planarization with Ecliptic plane remains unachievable due to weak tidal coupling between Earth and Moon. E-M system falls in Cassini State 1 in 214My from NOW. In 992.56My from NOW Moon’s ‘orbit’ gets completely circularized and synchronized. In 1.1Gy Sun’s brightness increases 10% and Earth becomes moist greenhouse planet. In 1.3458Gy from NOW Earth Obliquity angle reaches an eco-hostile value of 30.42⁰ with complete destruction of Habitat trinity. In 2Gy from NOW due to Moon’s resonance passage there is large oscillations of obliquity and severe climatic alterations. In 3.5Gy Sun’s brightness increases 40% and Earth becomes a runaway greenhouse planet reducing to a molten remnant. If E-M system survives Red Giant Branch stage, Thermal Pulse-Asymtotic Giant Branch stage, the Planetary Nebular phase and if it survives the present phase of Big-Bang of our Bouncing Universe then in 97Gy from NOW Moon will get interlocked with Earth in a triple synchrony orbital period of 44.7473 d at aG2 = 534,590.6Km.","PeriodicalId":437292,"journal":{"name":"Journal of Mathematical Techniques and Computational Mathematics","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122701019","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}

引用次数: 0