Mathematical and Computer Modelling最新文献_第4页

Comparative study of different B-spline approaches for functional data 函数数据不同b样条方法的比较研究

Mathematical and Computer Modelling Pub Date : 2013-10-01 DOI: 10.1016/j.mcm.2013.04.007

A.M. Aguilera , M.C. Aguilera-Morillo

{"title":"Comparative study of different B-spline approaches for functional data","authors":"A.M. Aguilera , M.C. Aguilera-Morillo","doi":"10.1016/j.mcm.2013.04.007","DOIUrl":"10.1016/j.mcm.2013.04.007","url":null,"abstract":"<div><p>The sample observations of a functional variable are functions that come from the observation of a statistical variable in a continuous argument that in most cases is the time. But in practice, the sample functions are observed in a finite set of points. Then, the first step in functional data analysis is to reconstruct the functional form of sample curves from discrete observations. The sample curves are usually represented in terms of basis functions and the basis coefficients are fitted by interpolation, when data are observed without error, or by least squares approximation, in the other case. The main purpose of this paper is to compare three different approaches for estimating smooth sample curves observed with error in terms of <span><math><mi>B</mi></math></span>-spline basis: regression splines (non-penalized least squares approximation), smoothing splines (continuous roughness penalty) and <span><math><mi>P</mi></math></span>-splines (discrete roughness penalty). The performance of these spline smoothing approaches is studied via a simulation study and several applications with real data. Cross-validation and generalized cross-validation are adapted to select a common smoothing parameter for all sample curves with the roughness penalty approaches. From the results, it is concluded that both penalized approaches drastically reduced the mean squared errors with respect to the original smooth sample curves with <span><math><mi>P</mi></math></span>-splines giving the best approximations with less computational cost.</p></div>","PeriodicalId":49872,"journal":{"name":"Mathematical and Computer Modelling","volume":"58 7","pages":"Pages 1568-1579"},"PeriodicalIF":0.0,"publicationDate":"2013-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.mcm.2013.04.007","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87981899","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 42

The parameter sensibility analysis for fishing box tap based on the overall process of elastoplasticity in oil and gas wells 基于油气井弹塑性整体过程的渔盒抽头参数敏感性分析

Mathematical and Computer Modelling Pub Date : 2013-10-01 DOI: 10.1016/j.mcm.2013.06.004

Xiao-Hua Zhu, Yu Wang, Hua Tong

{"title":"The parameter sensibility analysis for fishing box tap based on the overall process of elastoplasticity in oil and gas wells","authors":"Xiao-Hua Zhu, Yu Wang, Hua Tong","doi":"10.1016/j.mcm.2013.06.004","DOIUrl":"10.1016/j.mcm.2013.06.004","url":null,"abstract":"<div><p>In view that the selections of box tap and thread making parameters are still groundless and lack scientific evidence, which has caused many practical engineering problems, such as long fishing cycle and low success rate, this study establishes a mathematical model such that fish is fished by the box tap based on the theory of large deformation and principle of virtual work. The analysis and evaluation methods of the whole elastoplasticity process for tapping and fishing are proposed as well in accordance with Johnson and Cook’s experimental model and separation criterion in our study. In addition, the effects of such factors (drilling pressure, rotation speed, box tap strength, taper and pitch) on the thread making capacity of the box tap and the new thread strength of fish have been systemically analyzed. In the case study, the paper derives the safety rotation speed range of tapping, the optimal box tap tape and parameter combination of fishing, and the maximum allowable lifting power. The results obtained in our study show that the analyzing model and evaluation methods are quite reasonable and can be generally applied, which will be of great significance for the enhancement of fishing efficiency in future industry.</p></div>","PeriodicalId":49872,"journal":{"name":"Mathematical and Computer Modelling","volume":"58 7","pages":"Pages 1540-1547"},"PeriodicalIF":0.0,"publicationDate":"2013-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.mcm.2013.06.004","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90708791","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Approximate solution of linear differential equations 线性微分方程的近似解

Mathematical and Computer Modelling Pub Date : 2013-10-01 DOI: 10.1016/j.mcm.2013.06.011

Nadhem ECHI

引用次数: 2

Upgraded Petri net model and analysis of adaptive and static arithmetic coding 改进了Petri网模型，分析了自适应静态算法编码

Mathematical and Computer Modelling Pub Date : 2013-10-01 DOI: 10.1016/j.mcm.2013.06.001

Perica Štrbac , Gradimir V. Milovanović

引用次数: 2

Solution of system of the mixed Volterra–Fredholm integral equations by an analytical method 用解析方法求解混合Volterra-Fredholm积分方程组

Mathematical and Computer Modelling Pub Date : 2013-10-01 DOI: 10.1016/j.mcm.2013.06.006

M. Ghasemi , M. Fardi , R. Khoshsiar Ghaziani

引用次数: 16

Stability analysis of switched systems with general nonlinear disturbances 具有一般非线性扰动的切换系统稳定性分析

Mathematical and Computer Modelling Pub Date : 2013-10-01 DOI: 10.1016/j.mcm.2013.05.001

Jiu-Gang Dong

引用次数: 11

A novel identification method for Wiener systems with the limited information 有限信息下维纳系统的一种新的辨识方法

Mathematical and Computer Modelling Pub Date : 2013-10-01 DOI: 10.1016/j.mcm.2013.06.005

Qibing Jin , Jun Dou , Feng Ding , Liting Cao

引用次数: 9

Energy-efficient carpool policy for wireless interfaces of mobile devices in ubiquitous environments 无所不在环境下移动设备无线接口的节能拼车策略

Mathematical and Computer Modelling Pub Date : 2013-09-01 DOI: 10.1016/j.mcm.2013.01.006

Sung-Hwa Lim , Jungsup Oh , Byoung-Hoon Lee , Se Won Lee , Mye Sohn

{"title":"Energy-efficient carpool policy for wireless interfaces of mobile devices in ubiquitous environments","authors":"Sung-Hwa Lim , Jungsup Oh , Byoung-Hoon Lee , Se Won Lee , Mye Sohn","doi":"10.1016/j.mcm.2013.01.006","DOIUrl":"10.1016/j.mcm.2013.01.006","url":null,"abstract":"<div><p>Nowadays, power consumption is a big concern for mobile devices because battery power of mobile devices is one of the most crucial resources. Unfortunately, the performance of battery power fails to meet the power needs of high-end mobile devices. Increased data to be transferred/received through wireless communication incur high power consumption, because the wireless communication interface is one of the most dominant modules of mobile devices in terms of power consumption. Therefore, efficient power management of wireless interfaces should be employed for mobile devices. Dynamic power management is widely employed in order to support multiple power modes such as active modes (e.g., transmit, receive, and idle mode) and inactive modes (e.g., sleep mode and power off). Therefore maximizing the staying time of the wireless interface in an inactive mode is an essential scheme to reduce energy expenditure. However, required overhead energy and time for turning on/off the wireless interface are not negligible. Most of recent works have been trying to enhance the hardware architecture or network/MAC protocols. In this paper, we present an energy-efficient carpool policy that turns on the wireless interface and transmits all awaited data only when the predefined threshold is exceeded. We propose two kinds of thresholds–time and space. For practical evaluation, we conduct not only simulations but also experimental measurements by implementing a test program on a real test bed. Results of simulation and experimental measurements show that our proposed scheme incurs less energy expenditure than legacy power management schemes do.</p></div>","PeriodicalId":49872,"journal":{"name":"Mathematical and Computer Modelling","volume":"58 5","pages":"Pages 1301-1312"},"PeriodicalIF":0.0,"publicationDate":"2013-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.mcm.2013.01.006","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75731502","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

Foreign investment, innovation capacity and environmental efficiency in China 中国的外商投资、创新能力和环境效率

Mathematical and Computer Modelling Pub Date : 2013-09-01 DOI: 10.1016/j.mcm.2012.08.012

Xia Gao , Wei Zhang

引用次数: 22

Modeling energy consumption in next-generation wireless access-over-WDM networks with hybrid power sources 基于混合电源的下一代wdm无线接入网络能耗建模

Mathematical and Computer Modelling Pub Date : 2013-09-01 DOI: 10.1016/j.mcm.2012.12.004

Sergio Ricciardi , Francesco Palmieri , Ugo Fiore , Aniello Castiglione , Germán Santos-Boada

{"title":"Modeling energy consumption in next-generation wireless access-over-WDM networks with hybrid power sources","authors":"Sergio Ricciardi , Francesco Palmieri , Ugo Fiore , Aniello Castiglione , Germán Santos-Boada","doi":"10.1016/j.mcm.2012.12.004","DOIUrl":"10.1016/j.mcm.2012.12.004","url":null,"abstract":"<div><p>Energy consumption is now one of the most important issues for network carriers, since the majority of the energy needed for their operation is consumed in the wireless access and optical transport networks. The continuous growth in the wireless customers and traffic volumes and the consequent energy demand on modern carriers’ broadband infrastructures require reconsidering their energy efficiency, by starting from the formulation of new, more complete and representative network models that should become the foundations for modern energy-aware control plane architectures.</p><p>Accordingly, this work presents a novel comprehensive energy model for next-generation wireless access-over-optical-transport networks characterized by hybrid power systems (i.e., multiple dynamically available power sources). The objective is to identify the energy-related information that need to be handled at the control plane layer to support energy-aware networking practices. Such information can be made available to suitable energy-aware routing and wavelength assignment algorithms that may exploit them to optimize the overall network energy-consumption and reducing the associated carbon footprint. The proposed model may be taken as a reference for the implementation of new energy-aware control plane protocols (routing and signaling) that make use of power-related considerations to achieve energy-efficiency and energy-awareness in wavelength-routed network infrastructures.</p></div>","PeriodicalId":49872,"journal":{"name":"Mathematical and Computer Modelling","volume":"58 5","pages":"Pages 1389-1404"},"PeriodicalIF":0.0,"publicationDate":"2013-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.mcm.2012.12.004","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86101864","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 13