期刊文献+
共找到13篇文章
< 1 >
每页显示 20 50 100
Modelling Epidemiological Data Using Box-Jenkins Procedure 被引量:2
1
作者 Stanley Jere Edwin Moyo 《Open Journal of Statistics》 2016年第2期295-302,共8页
In this paper, the Box-Jenkins modelling procedure is used to determine an ARIMA model and go further to forecasting. We consider data of Malaria cases from Ministry of Health (Kabwe District)-Zambia for the period, 2... In this paper, the Box-Jenkins modelling procedure is used to determine an ARIMA model and go further to forecasting. We consider data of Malaria cases from Ministry of Health (Kabwe District)-Zambia for the period, 2009 to 2013 for age 1 to under 5 years. The model-building process involves three steps: tentative identification of a model from the ARIMA class, estimation of parameters in the identified model, and diagnostic checks. Results show that an appropriate model is simply an ARIMA (1, 0, 0) due to the fact that, the ACF has an exponential decay and the PACF has a spike at lag 1 which is an indication of the said model. The forecasted Malaria cases for January and February, 2014 are 220 and 265, respectively. 展开更多
关键词 Box-Jenkins modeling procedure ARIMA model Exponential Decay SPIKE
下载PDF
Structural Characteristics and Influencing Factors of Carbon Emission Spatial Association Network:A Case Study of Yangtze River Delta City Cluster,China
2
作者 BI Xi SUN Renjin +2 位作者 HU Dongou SHI Hongling ZHANG Han 《Chinese Geographical Science》 SCIE CSCD 2024年第4期689-705,共17页
City cluster is an effective platform for encouraging regionally coordinated development.Coordinated reduction of carbon emissions within city cluster via the spatial association network between cities can help coordi... City cluster is an effective platform for encouraging regionally coordinated development.Coordinated reduction of carbon emissions within city cluster via the spatial association network between cities can help coordinate the regional carbon emission management,realize sustainable development,and assist China in achieving the carbon peaking and carbon neutrality goals.This paper applies the improved gravity model and social network analysis(SNA)to the study of spatial correlation of carbon emissions in city clusters and analyzes the structural characteristics of the spatial correlation network of carbon emissions in the Yangtze River Delta(YRD)city cluster in China and its influencing factors.The results demonstrate that:1)the spatial association of carbon emissions in the YRD city cluster exhibits a typical and complex multi-threaded network structure.The network association number and density show an upward trend,indicating closer spatial association between cities,but their values remain generally low.Meanwhile,the network hierarchy and network efficiency show a downward trend but remain high.2)The spatial association network of carbon emissions in the YRD city cluster shows an obvious‘core-edge’distribution pattern.The network is centered around Shanghai,Suzhou and Wuxi,all of which play the role of‘bridges’,while cities such as Zhoushan,Ma'anshan,Tongling and other cities characterized by the remote location,single transportation mode or lower economic level are positioned at the edge of the network.3)Geographic proximity,varying levels of economic development,different industrial structures,degrees of urbanization,levels of technological innovation,energy intensities and environmental regulation are important influencing factors on the spatial association of within the YRD city cluster.Finally,policy implications are provided from four aspects:government macro-control and market mechanism guidance,structural characteristics of the‘core-edge’network,reconfiguration and optimization of the spatial layout of the YRD city cluster,and the application of advanced technologies. 展开更多
关键词 carbon emission spatial association network social network analysis(SNA) quadratic assignment procedure(QAP)model Yangtze River Delta city cluster China
下载PDF
3D Model Reconstruction Based on Process Information 被引量:1
3
作者 SHI Yun-fei ZHANG Shu-sheng CAO Ju-lu FAN Hai-tao YANG Yan 《Computer Aided Drafting,Design and Manufacturing》 2007年第2期15-22,共8页
The traditional strategy of 3D model reconstruction mainly concentrates on orthographic projections or engineering drawings. But there are some shortcomings. Such as, only few kinds of solids can be reconstructed, the... The traditional strategy of 3D model reconstruction mainly concentrates on orthographic projections or engineering drawings. But there are some shortcomings. Such as, only few kinds of solids can be reconstructed, the high complexity of time and less information about the 3D model. The research is extended and process card is treated as part of the 3D reconstruction. A set of process data is a superset of 2D engineering drawings set. The set comprises process drawings and process steps, and shows a sequencing and asymptotic course that a part is made from roughcast blank to final product. According to these characteristics, the object to be reconstructed is translated from the complicated engineering drawings into a series of much simpler process drawings. With the plentiful process information added for reconstruction, the disturbances such as irrelevant graph, symbol and label, etc. can be avoided. And more, the form change of both neighbor process drawings is so little that the engineering drawings interpretation has no difficulty; in addition, the abnormal solution and multi-solution can be avoided during reconstruction, and the problems of being applicable to more objects is solved ultimately. Therefore, the utility method for 3D reconstruction model will be possible. On the other hand, the feature information in process cards is provided for reconstruction model. Focusing on process cards, the feasibility and requirements of Working Procedure Model reconstruction is analyzed, and the method to apply and implement the Natural Language Understanding into the 3D reconstruction is studied. The method of asymptotic approximation product was proposed, by which a 3D process model can be constructed automatically and intelligently. The process model not only includes the information about parts characters, but also can deliver the information of design, process and engineering to the downstream applications. 展开更多
关键词 3D model reconstruction natural language understanding process cards working procedure model feature model
下载PDF
利用地震记录反演震源非均匀特征的一些问题 被引量:2
4
作者 金星 《地震工程与工程振动》 CSCD 北大核心 1997年第3期15-21,共7页
利用地震记录反演震源非均匀特征是目前强震地震学研究中的一个重要的课题。本文在总结现有文献的基础上,对与震源反演相关联的六个环节即震源模型及模型参数、格林函数计算、观测数据、反演准则与目标函数、初始模型与迭代方式、反演... 利用地震记录反演震源非均匀特征是目前强震地震学研究中的一个重要的课题。本文在总结现有文献的基础上,对与震源反演相关联的六个环节即震源模型及模型参数、格林函数计算、观测数据、反演准则与目标函数、初始模型与迭代方式、反演精度与分辨率等进行了初步阐述和分析,同时对震源反演中存在的问题也进行了相应的讨论。 展开更多
关键词 震源反演 模型参数 地震记录 震源 非均匀特征
下载PDF
自动矢量网络分析仪10个误差模型自校准技术
5
作者 方子文 沈庭芝 《北京理工大学学报》 EI CAS CSCD 1997年第6期712-716,共5页
自校准技术是精确测量微波晶体管参数和精密校准自动矢量网络分析仪的关键技术,利用信号流图和矩阵方法,分析了测量微波晶体管S参数的3种电路模型,给出了10个和8个误差参数的显式解,为各种型号的矢量网络分析仪测量微波晶体管... 自校准技术是精确测量微波晶体管参数和精密校准自动矢量网络分析仪的关键技术,利用信号流图和矩阵方法,分析了测量微波晶体管S参数的3种电路模型,给出了10个和8个误差参数的显式解,为各种型号的矢量网络分析仪测量微波晶体管S参数,提供了精确测试方法. 展开更多
关键词 矢量网络分析仪 误差模型 微波晶体管 自校准法
下载PDF
The effect of mining face's direction on the observed seismic activity 被引量:8
6
作者 Witold Pytel Joanna Switon Adrian Wojcik 《International Journal of Coal Science & Technology》 EI 2016年第3期322-329,共8页
A major natural hazard associated with LGOM (Legnica-Glogow Copper Mining) mining is the dynamic phenomena occurrence, physically observed as seismic tremors. Some of them generate effects in the form of relaxations... A major natural hazard associated with LGOM (Legnica-Glogow Copper Mining) mining is the dynamic phenomena occurrence, physically observed as seismic tremors. Some of them generate effects in the form of relaxations or bumps. Long-term observations of the rock mass behaviour indicate that the degree of seismic hazard, and therefore also seismic activity in the LGOM area, is affected by the great depth of the copper deposit, high-strength rocks as well as the ability of rock mass to accumulate elastic energy. In this aspect, the effect of the characteristics of initial stress tensor and the orientation of considered mining panel in regards to its components must be emphasised. The primary objective of this study is to answer the question, which of the factors considered as "influencing" the dynamic phenomena occurrence in copper mines have a statistically significant effect on seismic activity and to what extent. Using the general linear model procedure, an attempt has been made to quantify the impact of different parameters, including the depth of deposit, the presence of goaf in the vicinity of operating mining panels and the direction of mining face advance, on seismic activity based on historical data from 2000 to 2010 concerned with the dynamic phenomena recorded in different mining panels in Rudna mine. The direction of mining face advance as well as the goaf situation in the vicinity of the mining panel are of the greatest interest in the case of the seismic activity in LGOM. It can be assumed that the appropriate manipulation of parameters of mining systems should ensure the safest variant of mining method under specific geological and mining conditions. 展开更多
关键词 Induced seismicity Polish copper mines General linear model procedure
下载PDF
The Hutong neighbourhood grammar:A procedural modelling approach to unravel the rationale of historical Beijing urban structure
7
作者 Yuyang Wang Andrew Crompton Asterios Agkathidis 《Frontiers of Architectural Research》 CSCD 2023年第3期458-476,共19页
Hutong neighbourhoods,composed of Chinese courtyard dwellings(Siheyuan),are historically and socially significant urban spaces that embody the traditional Chinese way of life and philosophy.As part of the national her... Hutong neighbourhoods,composed of Chinese courtyard dwellings(Siheyuan),are historically and socially significant urban spaces that embody the traditional Chinese way of life and philosophy.As part of the national heritage,there is an increasing research interest in Hutong neighbourhoods,many of which are facing oblivion.This study presents a formal grammar for Hutong neighbourhood generation.This research investigates traditional principles of urban planning of ancient Beijing,based on examples on the historical map Qianlong Jingcheng Quantu,to derive the lost design rules.These rules are used to build up a procedural modelling framework,which reveals the development of Beijing’s urban structure from the Yuan(1271–1368)to the Qing(1644–1911)dynasty.Our findings present a grammar incorporated into the procedural modelling framework to parametrically generate Hutong neighbourhoods,which replicates the morphological characteristics of historic cases.It contributes to the understanding of the generation of Hutong neighbourhoods.In support of heritage sustainability,this grammar can be implemented in a computational environment by visual scripting that enables the generation of new instances of Hutong neighbourhoods,both real and virtual. 展开更多
关键词 Urban morphology Siheyuan Hutong neighbourhood Procedural modelling Shape grammar
原文传递
Discriminant Analysis of the Linear Separable Data - Japanese 44 Cars
8
作者 Shuichi Shinmura 《Journal of Statistical Science and Application》 2016年第4期165-178,共14页
There are four serious problems in the discriminant analysis. We developed an optimal linear discriminant function (optimal LDF) based on the minimum number of misclassification (minimum NM) using integer programm... There are four serious problems in the discriminant analysis. We developed an optimal linear discriminant function (optimal LDF) based on the minimum number of misclassification (minimum NM) using integer programming (IP). We call this LDF as Revised IP-OLDF. Only this LDF can discriminate the cases on the discriminant hyperplane (Probleml). This LDF and a hard-margin SVM (H-SVM) can discriminate the lineary separable data (LSD) exactly. Another LDFs may not discriminate the LSD theoretically (Problem2). When Revised IP-OLDF discriminate the Swiss banknote data with six variables, we find MNM of two-variables model such as (X4, X6) is zero. Because MNMk decreases monotounusly (MNMk 〉= MNM(k+1)), sixteen MNMs including (X4, X6) are zero. Until now, because there is no research of the LSD, we surveyed another three linear separable data sets such as: 18 exam scores data sets, the Japanese 44 cars data and six microarray datasets. When we discriminate the exam scores with MNM=0, we find the generalized inverse matrix technique causes the serious Problem3 and confirmed this fact by the cars data. At last, we claim the discriminant analysis is not the inferential statistics because there is no standard errors (SEs) of error rates and discriminant coefficients (Problem4). Therefore, we poroposed the "100-fold cross validation for the small sample" method (the method). By this break-through, we can choose the best model having minimum mean of error rate (M2) in the validation sample and obtaine two 95% confidence intervals (CIs) of error rate and discriminant coefficients. When we discriminate the exam scores by this new method, we obtaine the surprising results seven LDFs except for Fisher's LDF are almost the same as the trivial LDFs. In this research, we discriminate the Japanese 44 cars data because we can discuss four problems. There are six independent variables to discriminate 29 regular cars and 15 small cars. This data is linear separable by the emission rate (X1) and the number of seats (X3). We examine the validity of the new model selection procedure of the discriminant analysis. We proposed the model with minimum mean of error rates (M2) in the validation samples is the best model. We had examined this procedure by the exam scores, and we obtain good results. Moreover, the 95% CI of eight LDFs offers us real perception of the discriminant theory. However, the exam scores are different from the ordinal data. Therefore, we apply our theory and procedure to the Japanese 44 cars data and confirmed the same conclution. 展开更多
关键词 model Selection procedure Means of Error Rates Fisher's LDF Logistic Regression Support VectorMachine (SVM) Minimum Number of Misclassifications (minimum NM MNM) Revised IP-OLDF based onMNM criterion Revised IPLP-OLDF Revised LP-OLDF Linear Separable Data and model K-fold Crossvalidation.
下载PDF
Increasing detail of 3D models through combined photogrammetric and procedural modelling 被引量:1
9
作者 Stefan MÜLLER ARISONA Chen ZHONG +1 位作者 Xianfeng HUANG Rongjun QIN 《Geo-Spatial Information Science》 SCIE EI 2013年第1期45-53,共9页
This study addresses the need of making reality-based 3D urban models more detailed.Our method combines the established workflows from photogrammetry and procedural modelling in order to exploit distinct advantages of... This study addresses the need of making reality-based 3D urban models more detailed.Our method combines the established workflows from photogrammetry and procedural modelling in order to exploit distinct advantages of both approaches.Our overall workflow uses photogrammetry for measuring geo-referenced satellite imagery to create 3D building models and textured roof geometry.The results are then used to create attributed building footprints,which can be applied in the procedural modelling part of the workflow.Thereby procedural building models and detailed façade structures,based on street-level photos,are created.The final step merges the textured roof geometry with the procedural façade geometry,resulting in an improved model compared with using each technique alone.The article details the individual workflow steps and exemplifies the approach by means of a concrete case study carried out in Singapore's Punggol area,where we modelled a newly developed part of Singapore,consisting mainly of 3D high-rise towers. 展开更多
关键词 procedural modelling reality-based modelling PHOTOGRAMMETRY
原文传递
Procedural modeling of water caustics and foamy water for cartoon animation
10
作者 Jing LIAO 1,Jin-hui YU 1,Long JIA 2 (1 State Key Laboratory of CAD & CG,Zhejiang University,Hangzhou 310027,China) (2 School of Information Technology and Mathematical Sciences,University of Ballarat,Ballarat 3350,Australia) 《Journal of Zhejiang University-Science C(Computers and Electronics)》 SCIE EI 2011年第7期533-541,共9页
We propose a method for procedural modeling and animation of cartoon water effects such as water caustics,foamy wake,and longshore currents.In our method we emulate the visual abstraction of these cartoon effects by t... We propose a method for procedural modeling and animation of cartoon water effects such as water caustics,foamy wake,and longshore currents.In our method we emulate the visual abstraction of these cartoon effects by the use of Voronoi diagrams and the motion abstraction by designing relevant controlling mechanisms corresponding to each effect.Our system enables the creation of cartoon effects withminimal intervention from the animator.Through high-level initial specification,the effects are animated procedurally in the style of hand-drawn cartoons. 展开更多
关键词 Procedural modeling Water effects Non-photorealistic rendering Cartoon animation
原文传递
Effect of Morphology on Word Acquisition: An Investigation on the Acquisition of Psych Adjectives
11
作者 徐承萍 景漾 《Chinese Journal of Applied Linguistics》 2015年第2期204-218,247,共16页
Morphology is said to play a role in word acquisition. English psych adjectives are identified as a category of words with morphological complex gradience, which consists of free morphs, derivatives and inflections. D... Morphology is said to play a role in word acquisition. English psych adjectives are identified as a category of words with morphological complex gradience, which consists of free morphs, derivatives and inflections. Due to their morphological features, psych adjectives were considered the ideal candidates to test the effect of morphology on word acquisition. This study adopted a within-group research design, where a controlled productive test and a receptive knowledge test were developed and administered to English learners of an intermediate level. Results suggested that acquisition of the inflections was significantly different from that of free morphs and derivatives in the controlled productive test, but no difference was found in the receptive knowledge test. Comparisons of the two tests for the three word groups showed that the only significant difference occurred in the inflection word group. The overall results revealed that learners experienced much more difficulty in acquiring inflectional psych adjectives. In light of the dissociation of associative memory and rule memory, two possible explanations for the learning problems were offered: 1) learners failed to represent the inflections in associative memory, or 2) they have not proceduralized the morphology rules in rule memory. 展开更多
关键词 MORPHOLOGY vocabulary acquisition the Declarative / Procedural model of Lexicon and Grammar
原文传递
Visual simulation of clouds 被引量:2
12
作者 Yoshinori Dobashi Kei Iwasaki +1 位作者 Yonghao Yue Tomoyuki Nishita 《Visual Informatics》 EI 2017年第1期1-8,共8页
Clouds play an important role when synthesizing realistic images of outdoor scenes.The realistic display of clouds is therefore one of the important research topics in computer graphics.In order to display realistic c... Clouds play an important role when synthesizing realistic images of outdoor scenes.The realistic display of clouds is therefore one of the important research topics in computer graphics.In order to display realistic clouds,we need methods for modeling,rendering,and animating clouds realistically.It is also important to control the shapes and appearances of clouds to create certain visual effects.In this paper,we explain our efforts and research results to meet such requirements,together with related researches on the visual simulation of clouds. 展开更多
关键词 CLOUDS Procedural modeling Image-based modeling Fluid simulation Feedback control Genetic algorithms
原文传递
A procedural footprint enhancement of global topographic surface with multiple levels of detail
13
作者 Lukáš Brůha Jan Kolář 《International Journal of Digital Earth》 SCIE 2020年第4期527-545,共19页
Virtual globes are technologies for visual navigation through a threedimensional,multi-resolution model of the entire planet.Data representations used in virtual globes,however,lack geometric flexibility at high-resol... Virtual globes are technologies for visual navigation through a threedimensional,multi-resolution model of the entire planet.Data representations used in virtual globes,however,lack geometric flexibility at high-resolution levels of the planet-wide terrain surface.This is a problem especially if boundaries between individual geospatial features and the terrain are important.A novel integration of individual polygonal boundaries with a specific multi-resolution representation of the planet-wide terrain is developed in this article.In the preparation stage,the integration relies on an original simplification algorithm applied to the polygonal boundaries between geospatial features and the terrain.Its output is a multiple level-of-detail(LOD)geometry,which can be combined with a known multi-LOD representation of the terrain that uses run-time triangulation.This data representation is suitable for storage in existing database systems,avoids any data redundancy across LODs,and is even independent of the subdivision schema that partitions the planet’s surface for the sake of dealing with LODs.At runtime,a novel reconstruction algorithm stitches geometric parts from different LODs together in a manner that augments the multi-LOD representation of the terrain.Within a certain proximity range from a given position,the method reconstructs a scene that preserves topological relations between the boundaries of geospatial features with the terrain.The method also guarantees that certain nearest proximity to the given position consists of the best geometries that correspond to the original datasets.Such properties of the method close up the gap between a mere exploratory visualization of static,pre-generated models and the models supporting geospatial analysis,which is deemed crucial for applications in Geographic Information Systems,Building Information Modelling and other software industries.A prototype implementation and experiment results that prove this method are also presented. 展开更多
关键词 Feature-based topography multiple level-of-detail procedural modeling vector data organization geometry reconstruction
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部