Detecting Design Patterns in Object-Oriented Program Source Code by Using Metrics and Machine Learning

Detecting well-known design patterns in object-oriented program source code can help maintainers understand the design of a program. Through the detection, the understandability, maintainability, and reusability of object-oriented programs can be improved. There are automated detection techniques;however, many existing techniques are based on static analysis and use strict conditions composed on class structure data. Hence, it is difficult for them to detect and distinguish design patterns in which the class structures are similar. Moreover, it is difficult for them to deal with diversity in design pattern applications. To solve these problems in existing techniques, we propose a design pattern detection technique using source code metrics and machine learning. Our technique judges candidates for the roles that compose design patterns by using machine learning and measurements of several metrics, and it detects design patterns by analyzing the relations between candidates. It suppresses false negatives and distinguishes patterns in which the class structures are similar. As a result of experimental evaluations with a set of programs, we confirmed that our technique is more accurate than two conventional techniques.

Gradient Analysis of Urbanization Pattern Based on Class-level Landscape Metrics for Shanghai Region

The spatial pattern of urbanization in the Shanghai metropolitan area is quantified with GIS-based land use data set and gradient analysis of landscape metrics. A number of landscape metrics were computed along a 64 Ion long and 6 km wide west-east transect and another 66 km long and 6 km wide south-north transect. The results of transect analysis with class-level metrics showed that the spatial pattern of urbanization could be reliably quantified using landscape metrics with a gradient analysis approach, and the location of the urbanization center could be identified precisely and consistently with multiple indices of the landscape metrics used in this study. Different land use types exhibited distinctive, but not necessarily unique, spatial signatures that were dependent on specific landscape metrics. These results seemed to characterize the urban core of the Shanghai metropolitan area rather accurately and precisely.. Agriculture patches were abundant and less fragmented; the urban land use types were extensive, having many small patches and highly fragmented.

Geographic patterns of taxonomic and phylogenetic β-diversity of aquatic angiosperms in China

China covers a vast territory harbouring a large number of aquatic plants.Although there are many studies on the β-diversity of total,herbaceous or woody plants in China and elsewhere,few studies have focused on aquatic plants.Here,we analyse a comprehensive data set of 889 aquatic angiosperm species in China,and explore the geographic patterns and climatic correlates of total taxonomic and phylogeneticβ-diversity as well as their turnover and nestedness components.Our results show that geographic patterns of taxonomic and phylogenetic β-diversity are highly congruent for aquatic angiosperms,and taxonomic β-diversity is consistently higher than phylogenetic β-diversity.The ratio between the nestedness component and total β-diversity is high in northwestern China and low in southeastern China.The geographic patterns of taxonomic and phylogenetic β-diversity of aquatic angiosperms in China are obviously affected by geographic and climatic distances,respectively.In conclusion,the geographic patterns of taxonomic and phylogenetic β-diversity of aquatic angiosperms are consistent across China.Climatic and geographic distances jointly affect the geographic patterns of β-diversity of aquatic angiosperms.Overall,our work provides insight into understanding the large-scale patterns of aquatic angiosperm β-diversity,and is a critical addition to previous studies on the macroecological patterns of terrestrial organisms.

Mapping Software Metrics to Module Complexity: A Pattern Classification Approach

A desirable software engineering goal is the prediction of software module complexity (a qualitative concept) using automatically generated software metrics (quantitative measurements). This goal may be couched in the language of pattern classification;namely, given a set of metrics (a pattern) for a software module, predict the class (level of complexity) to which the module belongs. To find this mapping from metrics to complexity, we present a classification strategy, stochastic metric selection, to determine the subset of software metrics that yields the greatest predictive power with respect to module complexity. We demonstrate the effectiveness of this strategy by empirically evaluating it using a publicly available dataset of metrics compiled from a medical imaging system and comparing the prediction results against several classification system benchmarks.

GAN与Diffusion在传统纹样设计中的实验研究

传统纹样是中国优秀传统文化的重要组成部分,传统人工设计已经无法满足纹样的现代设计需求,生成式AI为传统纹样设计提供了新的设计路径和方法。文章将生成式AI应用于传统纹样设计中,通过适配实验优选基于GAN的Style GAN和基于Diffusion的Stable Diffusion两种主流图像生成模型进行实验,采用技术分析与艺术分析相结合,对实验结果进行多角度、多维度对比分析,为设计师选择生成设计方法提供参照。实验结果表明,两个模型均能满足基本的艺术设计需求。Style GAN模型生成的纹样图像更接近真实图像的分布,具有更高的图像质量和多样性;Stable Diffusion模型能较好地传承传统纹样的基因,艺术性与创造性兼具,更加符合传统纹样的艺术设计需求。

基于Usage Metrics的中文学术论文用户平台偏好和兴趣偏好比较研究

研究中文学术论文用户使用模式有助于分析使用规律,为应用决策提供依据。本文以八个学科被CSSCI或CSCD收录的61本开放获取期刊发表于2014—2015年的学术论文为样本,以期刊官网和信息集成平台上的使用数据为来源,采用Usage Metrics的方法,从用户平台偏好和用户兴趣偏好两方面比较中文学术论文的用户使用模式。研究发现:(1)期刊官网与信息集成平台的用户平台偏好存在差异。一是从学科视角看,用户整体上倾向于使用期刊官网而不是信息集成平台获取所需论文,而社会科学的信息集成平台篇均下载次数均大于自然科学。二是从期刊视角看,社会科学用户比自然科学用户更倾向于使用信息集成平台获取所需论文;与信息集成平台相比,期刊官网的用户下载数据呈现更为明显的"两级分化"现象;期刊官网下载次数与信息集成平台下载次数整体上的相关性较低。(2)期刊官网与信息集成平台的用户兴趣偏好存在差异。每本期刊官网和信息集成平台下载次数前20%的学术论文的Jaccard相似系数较低;在所列举的图书馆、情报与文献学中,期刊官网与信息集成平台的用户关注主题不同。

SPATIAL GRADIENT ANALYSIS OF URBAN GREEN SPACES COMBINED WITH LANDSCAPE METRICS IN JINAN CITY OF CHINA

Urban green spaces have been arisen growing concern responded to the social and environmental costs of urban sprawl. A wide range of planning and policies has been and/or will be designed to protect urban green spaces and optimize their spatial pattern. A better design or planning of urban green space can make a major contribution to quality of environment and urban life, and furthermore can decide whether we can have a sustainable development in the urban area. Information about the status quo of urban green spaces can help planners design more effectively. However, how to quantify and capture such information will be the essential question we face. In this paper, to quantify the urban green space, a new method comprising gradient analysis, landscape metrics and GIS was developed through a case of Jinan City. The results demonstrate: 1) the gradient analysis is a valid and reliable instrument to quantify the urban green space spatial pattern precisely; 2) using moving window, explicit landscape metrics were spatially realized. Compared with quantifying metrics in the entire landscape, it would be better to link pattern with process and establish an important basis for analyzing the ecological and socioeconomic functions of green spaces.

Characterization of landscape pattern based on land economic niche change: A case study in Ganzhou,Gansu Province, China

Land use change has a profound impact on biodiversity and ecological processes, and is closely related to changes in landscape patterns. This paper introduces the theory and method of land economic niche into landscape ecology, which provides a new method for spatial characterization of urban and rural spatial landscape patterns. Based on this theory, this paper analyzes the landscape pattern of Ganzhou District by using Landsat images as data source in 1995, 2000, 2005, 2010 and 2015. We calculated the land economic niche by applying the niche potential theory. Combined with the theory of landscape ecology, we explored the effects of the land economic niche change on the landscape pattern at a county scale. The results show that economic niche of construction land, watershed and farmland increased during 1995-2015, and grassland declined significantly. The economic niche of farmland, construction land, watershed and grassland show a negative correlation with the number of patches （NP）, fragmentation index （FN） and the fractal dimension index （FD）, and had a positive correlation with the aggregation index （AI）. There was no significant correlation between the forest land economic niche and landscape metrics. The change of land economic niche has a driving effect on the landscape pattern of the county, which can represent the economic development direction of Ganzhou District. The land economic niche is closely related to the landscape type which can directly obtain an economic benefit.

Analysis of Rural Ecological Pattern Based on FRAGSTATS: A Case Study of Puxing Village in Pidu District

According to the plant information of Puxing Village, a typical village in Chengdu Plain, the GIS map was drawn to analyze the landscape ecology pattern by FRAGSTATS software. The results show that in the past 10 years, although urbanization had a great impact on the rural ecological pattern, it was still in a stable ecological environment. The comparison of the landscape index shows that the replacement of the vegetation community pattern leads to the conversion of the source population from the original farmland to laurel, and the increase of whole vegetation community under artificial intervention is the most important factor for the change of the vegetation community richness. At the same time, the pattern analysis at the horizontal level also reveals the obvious effect of the fast road as an artificial product for the enhancement of nearby vegetation community richness.

Road Centrality and Landscape Spatial Patterns in Wuhan Metropolitan Area,China

Road network is a corridor system that interacts with surrounding landscapes,and understanding their interaction helps to develop an optimal plan for sustainable transportation and land use.This study investigates the relationships between road centrality and landscape patterns in the Wuhan Metropolitan Area,China.The densities of centrality measures,including closeness,betweenness,and straightness,are calculated by kernel density estimation(KDE).The landscape patterns are characterized by four landscape metrics,including percentage of landscape(PLAND),Shannon′s diversity index(SHDI),mean patch size(MPS),and mean shape index(MSI).Spearman rank correlation analysis is then used to quantify their relationships at both landscape and class levels.The results show that the centrality measures can reflect the hierarchy of road network as they associate with road grade.Further analysis exhibit that as centrality densities increase,the whole landscape becomes more fragmented and regular.At the class level,the forest gradually decreases and becomes fragmented,while the construction land increases and turns to more compact.Therefore,these findings indicate that the ability and potential applications of centrality densities estimated by KDE in quantifying the relationships between roads and landscapes,can provide detailed information and valuable guidance for transportation and land-use planning as well as a new insight into ecological effects of roads.

Pattern Change of Urban Green Space in Beijing from 2000 to 2010

With the rapid urbanization in Beijing, the vegetated surfaces have been increasingly replaced by impervious built surfaces. A clear recognition on the changes in green spaces pattern is vital for urban administrators and planners to optimize the urban development areas and define the ecological protection red lines. Based on the SPOT images and field investigation data of urban green spaces within the sixth ring road of Beijing in 2000, 2005 and 2010, the study investigated the dynamic changes of urban green spaces in this area, by means of GIS techniques and landscape ecology methods. The results indicated that green spaces in Beijing have decreased by 207 km2 from 2000 to 2010 at the expense of agricultural lands and waters. Although there has been some increases in urban forests and grasslands, it cannot compensate the rapid decrease of urban green spaces. The land cover types conversion occurred mainly in the areas between the fifth and sixth ring roads while the zones encircled by the fourth ring road had a little change. In addition, landscape metrics such as number of patches(NP) and shape index(SHAPE) increased, but the mean nearest-neighbor distance(MNN), aggregation index(AI) and patch cohesion index(COHESION) decreased during the period of 2000-2010. Also green landscapes became considerably isolated and fragmented. The study disclosed the obvious changes of green space size, composition and layout in urban districts of Beijing City from 2000 to 2010, and highlighted that construction of urban green space should consider not only the geometric or aesthetic effect, but also the increase of vertical green volume and optimization of spatial layout to fully develop the ecological service functions of green spaces.

Physical Growth Pattern of Settlements in a Traditional Region, Southwest Nigeria

The study examined the growth pattern of settlements in Oke-Ogun area of Oyo State, Nigeria between 1984 and 2011;and predicted the future growth pattern of settlements in the study area. Both primary and secondary data were used for this study. Primary sources of data include Global Positioning System (GPS), Landsat TM and ETM+ imageries of 1984, 1990, 2000, and 2011. Secondary data included administrative map and population data of the study area. Descriptive statistics and geospatial technique were used to analyse the data collected. The results showed a random pattern of settlement distribution in the study area. Results revealed that settlements covered about 0.52% of the total land area in 1984;1.32% in 2000;and 3.78% in 2011. Whereas linear pattern of growth characterised the periods between 1984 and 1990;clustering, infilling, and fringes were the patterns of growth that characterised the periods between 1990 and 2011. The study predicted that, at an average 1.2% of annual growth rate, settlements will occupy about 44.37% of the total land area by 2031. The study concluded that settlements in the study area varied in the patterns of distribution;the area was dominated by indigenous settlements type with overconcentration of social and economic infrastructures in few centres.

时空克里金评估河套灌区土壤盐分时空格局

区域土壤盐分时空变异性大,采用经典统计和地统计方法无法准确判断取样时间不规则、空间位置不一致的土壤盐分的时空变化趋势。本文以内蒙古河套灌区隆胜研究区68个监测点0~1.8 m土壤剖面4582个土壤盐分数据为基础,利用时空地统计方法分析区域土壤盐分时空变化特征,比较时空克里金较传统空间克里金插值的精度提升效果,并验证时空地统计方法在监测点减少50%情况下预测区域盐分时空动态的能力。结果表明:(1)该研究区土壤盐分空间变异系数的变化范围是0.43~1.14,为中强变异,0~0.6 m根系层生育期积盐、非生育期脱盐,0.6~1.8 m土壤剖面生育期脱盐、非生育期积盐、农田土壤盐分有明显的季节性规律。(2)和度量模型能较好拟合盐分时空经验半方差,各层土壤盐分预测值和观测值间的均方根误差RMSE均小于0.21 dS·m^(-1),较传统空间克里金的RMSE小0.02~0.09 d S·m^(-1)。(3)采用该方法在减少50%监测点情况下确定的土壤盐渍化分布与所有取样点确定的结果一致性较高,0~0.6 m和0.6~1.2 m土壤盐分面积间的相对误差MRE分别为-13.20%和-8.35%,RMSE为466.67hm2和494.43 hm2,决定系数R2为0.79和0.72。时空克里金同时利用了土壤盐分时间和空间上的更多信息,实现了稀疏盐分监测点数据集土壤盐分时空动态的精确估计,可极大提高区域土壤盐分时空格局监测的效率。

基于格律设计理论的海昏侯墓当卢纹样再设计研究

通过对海昏侯墓当卢样式工艺、艺术特征及纹样功能和文化内涵进行分析,基于格律设计理论指导,寻找关于当卢纹样再设计的方法,为海昏侯当卢纹样再设计提供一条新的设计之路。

景观格局指标对不同景观格局的反应

探讨了在人为控制不同因子变量的条件下各景观格局指标对由中性随机模型产生的不同景观格局系列的反应 ,以评价一些常用指标的实用性和局限性。研究结果表明 ,大部分指标所指示的格局特征往往是不全面的 ,即它们只对格局系列中个别因子的变化敏感 ,而对另一些因子的变化反应迟钝。比较值得推荐的指标有 :总斑块数目 ,平均斑块大小 ,总边界密度 ,分维数 ,蔓延度 ,聚集度。但即使是这些指标 ,也各有其局限性 ,且存在冗余。由此提醒读者在运用景观格局指标时应在了解其实际意义的基础上 ,结合生态学过程慎重选择和解释 ,避免陷于数字游戏。

景观生态学中的格局分析：现状、困境与未来

作为景观格局分析的重要手段,景观格局指数的提出与发展极大地推动了景观生态学的发展,但是由于众多景观格局指数在指示生态学过程方面的不足,近年来景观格局分析已经走入困境。在总结近年来国内外相关研究的基础上,对景观格局分析的现状、困境及未来发展方向进行了综述。景观格局分析仍然是景观生态学的重要方面,景观格局指数仍然是景观格局分析的主要手段。但是如何建立具有生态学意义的景观格局指数和分析方法,如何将景观格局与生态过程联系起来,以及如何将"基质—斑块—廊道"的景观生态学理论应用到实际中是目前景观格局分析面临的主要困境。基于对景观格局分析现状及困境的认识,提出了景观格局分析未来的5个发展方向:(1)景观格局分析应该从目前的静态格局描述发展到对动态格局的刻画,只有找到刻画动态格局的方法,才能将格局和过程有机地联系在一起;(2)通过对多种景观格局指数的联合应用,发掘景观格局指数集合体对生态过程的解释能力;(3)发展基于生态过程的景观格局指数和分析方法;(4)通过多维景观格局分析,定量研究景观格局演变与生态过程之间的关系;(5)多尺度景观格局分析,将为解决格局与过程的关系提出有效手段。

Identifying Landscape Pattern Metrics for the Hani Terrace in Yunnan, China

This study seeks to isolate a select group of landscape metrics particularly well-suited for describing the Hani Terrace in southwest of China.We examined the response of 47 landscape metrics to a large range of imagery grain sizes.Based on a correlation analysis,the original 47 metrics were placed into 21 groups such that all metrics within a group were strongly correlated with each other with a value of more than 0.9,and were represented by a single descriptor.Using these cross-sectional metrics in the context of principal components analysis,we found that five factors explained almost 93％ of the total variation in the landscape pattern.The highest loadings for these five factors were the Splitting index （SPLIT）,Patch area distribution （AREA_CV）,Shannon＇s diversity index （SHDI）,Euclidean nearest neighbor distance distribution （ENN_AM）,and Total core area （TCA）,respectively.Considering the real landscape,we added the Patch fractal dimension distribution （FRAC_MN） as the sixth landscape pattern metric.As the scale effect of landscape pattern metrics we design to investigate how a suite of commonly use landscape metrics respond to changing grain size.Based on the anlasis,we determined that the best domain of scale to characterise the Hani Terrace pattern metrics is between 40m and 45m.Through the fractal method,we found that the characteristic scale of the Hani Terrace is the same as the scale domain of metrics,among the 40m and 45m.We suggest that the majority of the patterns in the Hani Terrace landscapes,indeed for all those in southwest China,can be described effectively with these six metrics.

基于GIS的上海市景观格局梯度分析

定量分析景观格局及其变化对于监测和评价城市化的生态后果十分重要。该研究应用基于GIS的梯度分析与景观指数相结合的方法定量分析了上海市城市化的空间格局。沿一条自西向东 6 4km长 6km宽和另一条自南向北 6 6km长 6km宽的样带 ,应用移动窗口计算了一系列景观指数。结果表明 ,城市化的空间格局可以用梯度分析与景观指数来定量 ,不同的土地利用类型沿景观格局梯度确实表现出明显的“空间特征”。多项景观指数可准确地、定量地指示上海地区东西和南北发展轴线上城市化的前沿和城市景观梯度分异的特征。城市化的总体格局是随着城市化程度增加 ,景观在组分上更多样化 ,形状上更为复杂以及生态学上更破碎化。此外 ,该文显示的上海市城市化景观格局比较符合同心圆论的城市发展理论 ,研究结果支持斑块密度随城市化程度而增加 ,斑块大小和景观连接度则下降的假说 ,但与随人类干预程度增强 ,斑块形状变得更规则的假说不相符和 ,因此 。

上海市城乡梯度景观格局分析

利用 2 0 0 0年的土地利用数据 ,在 GIS的支持下 ,结合景观格局指数和梯度分析方法 ,研究了上海市景观结构及其在城市化梯度上的空间特征。结果表明 ,上海市的景观结构中 ,农田为优势景观 ,占整个景观比例的 6 0 %左右 ,而反映城市化的工业、居住和基础设施景观则占 2 2 % ,表明上海的城市化程度已经很高 ;郊区居住用地比例过大 (12 .6 9% ) ,城乡交错带居住区与工业区的高度混合显示上海市的景观结构需要优化 ,以提高土地利用率。样带上类型水平的景观格局指数分析表明各种景观类型表现出独特的空间特征 ,明显反映了城市化的梯度和前沿 ;而景观水平的格局分析则表明城市化导致景观的破碎化程度增大 ,景观异质性增高 ;景观格局指数曲线在城市化梯度上呈双峰型 ,是上海中心城区和浦东新区城市化区域的具体表现。研究结果表明景观格局指数和梯度分析相结合 ,是检测城市化和城市形态的有力工具。

空间幅度变化对景观格局分析的影响

景观格局指数是量化描述景观格局特征的主要方法之一 ,各种格局指数的尺度依赖性使比较分析景观格局特征和尺度推绎复杂化 ,分析不同指数随空间幅度变化的一般行为有助于景观格局分析结果的解释和降低空间尺度推绎的复杂性。研究以 2种真实景观和 2 7种模拟景观为分析对象 ,考查了 1 6种常用的景观水平格局指数随空间幅度变化行为。根据这些指数因幅度变化行为可预测性把它们分为两类 :第 1类随幅度变化可预测性强 ,指数与幅度之间的关系可用简单的函数关系来表达 ;这类指数包括缀块数、边界总长、景观形状指数和缀块丰度密度 ;前两者随幅度增加呈幂函数形式增加 ,而缀块丰度密度随幅度增加呈幂函数下降 ,景观形状指数随幅度增加呈直线增加。第 2类指数随幅度变化的可预测性较差 ,指数随幅度的变化存在多种可能 (不同形式的增加、减小或保持不变 ) ,不可用一种或多种简单的函数关系来描述所有的情况。这类指数包括缀块丰度、缀块密度、边界密度、最大缀块指数、平均缀块面积、缀块面积标准差、缀块面积变异系数、平均缀块形状指数、面积加权平均缀块形状指数、双对数回归分维数、聚集度指数与Shannon多样性指数。第 2类指数随幅度的变化行为受景观格局特征和指数本身算法的影响。总体上来说 ,第