Feature Extraction of Fabric Defects Based on Complex Contourlet Transform and Principal Component Analysis

To extract features of fabric defects effectively and reduce dimension of feature space,a feature extraction method of fabric defects based on complex contourlet transform （CCT） and principal component analysis （PCA） is proposed.Firstly,training samples of fabric defect images are decomposed by CCT.Secondly,PCA is applied in the obtained low-frequency component and part of highfrequency components to get a lower dimensional feature space.Finally,components of testing samples obtained by CCT are projected onto the feature space where different types of fabric defects are distinguished by the minimum Euclidean distance method.A large number of experimental results show that,compared with PCA,the method combining wavdet low-frequency component with PCA （WLPCA）,the method combining contourlet transform with PCA （CPCA）,and the method combining wavelet low-frequency and highfrequency components with PCA （WPCA）,the proposed method can extract features of common fabric defect types effectively.The recognition rate is greatly improved while the dimension is reduced.

委托代理理论视角下科技查新的共生应用研究

文章旨在通过委托代理理论视角研究科技查新的共生应用,探讨委托代理关系下科技查新的可能性和限制,为企业和个人在查新过程中提供理论指导。同时,通过委托代理理论视角科技查新的共生应用,为企业和个人在查新过程中提供了新的思路和方法。

城市更新项目中地方政府政策执行偏差影响因素的实证分析

识别城市更新项目政策执行背后深层影响机理是提高城市更新政策效果的重要路径。文中基于委托代理理论,结合文献分析提炼出地方政府政策执行影响因素,然后运用模糊集定性比较分析(fuzzy set qualitative comparative analysis, fsQCA)方法,构建分析框架,讨论目标模糊(blur goal, BG)、自利倾向(self-interested tendency, ST)、晋升激励(promotion incentive, PI)、资源禀赋(resources endow, RE)、监督与考核(supervision and assessment, SA)、执行压力(execution pressure, EP)这6个条件变量的不同组合,对城市更新项目政策执行偏差(policy implementation deviation, PID)的作用机理。研究发现,所有单一条件变量的一致性均小于0.9,表明这些因素并不构成城市更新项目政策执行偏差的必要条件。通过多变量组态分析,得出城市更新项目政策执行偏差发生的6条路径,并总结为目标漂移型偏差、激励不足型偏差、资源桎梏型偏差模式3种典型模式。其中,监督与考核缺位构成了政策执行偏差的核心条件。

Multi-response optimization of Ti-6A1-4V turning operations using Taguchi-based grey relational analysis coupled with kernel principal component analysis

Ti-6A1-4V has a wide range of applications, especially in the aerospace field;however, it is a difficultto- cut material. In order to achieve sustainable machining of Ti?6A1-4V, multiple objectives considering not only economic and technical requirements but also the environmental requirement need to be optimized simultaneously. In this work, the optimization design of process parameters such as type of inserts, feed rate, and depth of cut for Ti-6A1-4V turning under dry condition was investigated experimentally. The major performance indexes chosen to evaluate this sustainable process were radial thrust, cutting power, and coefficient of friction at the toolchip interface. Considering the nonlinearity between the various objectives, grey relational analysis (GRA) was first performed to transform these indexes into the corresponding grey relational coefficients, and then kernel principal component analysis (KPCA) was applied to extract the kernel principal components and determine the corresponding weights which showed their relative importance. Eventually, kernel grey relational grade (KGRG) was proposed as the optimization criterion to identify the optimal combination of process parameters. The results of the range analysis show that the depth of cut has the most significant effect, followed by the feed rate and type of inserts. Confirmation tests clearly show that the modified method combining GRA with KPCA outperforms the traditional GRA method with equal weights and the hybrid method based on GRA and PCA.

单一及组合引发剂对甜瓜种子萌发及幼苗生长的影响

以宁夏地区甜瓜主栽品种花兰柿老化种子为材料,选用3种引发剂(5 g·L^(-1)CaCl_(2)、2 g·L^(-1)MnSO_(4)·H_(2)O、1.25 g·L^(-1)水溶性壳聚糖)对甜瓜种子进行单一及组合渗透引发处理,探讨不同种类引发剂对甜瓜种子萌发及幼苗生长的影响,筛选最优的引发剂。标准发芽试验结果表明:单一和组合引发剂处理均能显著促进老化甜瓜种子发芽,其中,组合引发剂5 g·L^(-1)CaCl_(2)+2 g·L^(-1)MnSO_(4)·H_(2)O处理的甜瓜种子活力指数显著高于对照和其他处理。穴盘育苗结果表明:组合引发剂可提高甜瓜幼苗质量,显著增加幼苗的茎粗、总鲜质量、总干质量和壮苗指数,组合引发剂5 g·L^(-1)CaCl_(2)+2 g·L^(-1)MnSO_(4)·H_(2)O(T4)和5 g·L^(-1)CaCl_(2)+1.25 g·L^(-1)水溶性壳聚糖(T5)处理的壮苗指数分别是对照CK1的2.00倍和1.89倍。T5处理对幼苗叶片光合色素含量提升幅度最大,幼苗根系活力最高。主成分分析筛选结果表明T5处理效果最佳。本研究筛选出的组合引发剂能有效改善老化甜瓜种子活力,促进幼苗生长,增强幼苗素质,可为甜瓜高质量集约化育苗提供技术支持。

基于委托-代理理论的城市轨道交通激励约束机制博弈分析

城市轨道交通属于准经营性项目,其投资规模大、盈利能力差,采用特许权方式进行项目建设、运营时,需要政府部门对项目公司进行相应的扶持补贴。这种扶持补贴必须建立在现代委托-代理关系上,即建立相应的激励约束机制,以利于城市轨道交通项目能够低成本、高效率地运营。介绍了激励约束机制的重要性,运用博弈论对政府与项目公司的委托-代理关系进行了分析,得出政府给予项目公司的补贴是建立激励约束机制的关键。针对如何选择合理的补贴方式提出了相应的政策建议。

寿险激励机制局限性分析及其完善--基于委托代理模型角度

寿险公司与代理人之间本质上是一种委托代理关系,委托代理问题是寿险公司激励机制问题产生的根源。本文基于委托代理理论,根据现阶段寿险业激励机制的特征,对委托代理基本模型进行修正,通过修正后的模型分析得出寿险激励机制是以"业绩量"为核心设计与实行的,存在局限性,无法对代理人实现正确的激励。同时,通过实证调查研究寿险代理人在现行激励机制下的决策验证了模型分析的结论。最后,总结分析激励机制的局限性,为激励机制的完善提供一些对策。

Friction coefficient in rubber forming process of Ti-15-3 alloy

The forming limit diagram of Ti-15-3 alloy sheet was constituted at room temperature. The effects of different punch and rubber hardness on the limit principal strain distributions were investigated experimentally. Finite element analysis models of the samples with dimensions of 180 mm×180 mm were established to analyze the friction coefficients of different interfaces. Effects of various friction coefficients on the strain distributions were studied in detail. Finally, the friction coefficients in the cold forming were determined by contrasting the strain results between the experimental data and the simulated ones.

A comparative study on crash-influencing factors by facility types on urban expressway

This study aims at identifying crash-influencing factors by facility type of Nagoya Urban Expressway, considering the interaction of geometry, traffic flow, and ambient conditions. Crash rate （CR） model is firstly developed separately at four facility types： basic, merge, and diverge segments and sharp curve. Traffic flows are thereby categorized, and based on the traffic categories, the significances of factors affecting crashes are analyzed by principal component analysis. The results reveal that, the CR at merge segment is significantly higher than those at basic and diverge segments in uncongested flow, while the value is not significantly different at the three facility types in congested flow. In both un- and congested flows, sharp curve has the worst safety performance in view of its highest CR. Regarding influencing factors, geometric design and traffic flow are most significant in un- and congested flows, respectively. As mainline flow increases, the effect of merging ratio affecting crash is on the rise at basic and merge segments as opposed to the decreasing significance of diverging ratio at diverge segment. Mean- while, longer acceleration and deceleration lanes are adverse to safety in uncongested flow, while shorter acceleration and deceleration lanes are adverse in congested flow. Due to its special geometric design, crashes at sharp curve are highly associated with the large centrifugal force and heavy restricted visibility.

A Study on the Multi-Task Incentive Mechanism for the Service Provider

Both conflict and asymmetric information exist betweenthe telecom operators and the service provider,and result in illegal behaviors of the service provider.The relationship between the telecom operators andthe service provider is classical multi-task principalagentrelationship. The multi-task incentive for theservice provider is considered in the design of theprincipal-agent incentive contract, and it is necessaryto add the multi-task incentive to the serviceproviders through the analysis of the risk costs andthe agency costs of this problem.

Population Spatial Distribution Based on Luojia 1-01 Nighttime Light Image:A Case Study of Beijing

With the continuous development of urbanization in China,the country’s growing population brings great challenges to urban development.By mastering the refined population spatial distribution in administrative units,the quantity and agglomeration of population distribution can be estimated and visualized.It will provide a basis for a more rational urban planning.This paper takes Beijing as the research area and uses a new Luojia1-01 nighttime light image with high resolution,land use type data,Points of Interest(POI)data,and other data to construct the population spatial index system,establishing the index weight based on the principal component analysis.The comprehensive weight value of population distribution in the study area was then used to calculate the street population distribution of Beijing in 2018.Then the population spatial distribution was visualize using GIS technology.After accuracy assessments by comparing the result with the WorldPop data,the accuracy has reached 0.74.The proposed method was validated as a qualified method to generate population spatial maps.By contrast of local areas,Luojia 1-01 data is more suitable for population distribution estimation than the NPP/VIIRS(Net Primary Productivity/Visible infrared Imaging Radiometer)nighttime light data.More geospatial big data and mathematical models can be combined to create more accurate population maps in the future.

基于主成分分析和响应曲面法的烤肉腌制剂配方优化

论文以猪里脊肉为原料,考察茶多酚、大豆分离蛋白和大蒜对烤肉品质的影响。以感官评分、色泽、丙二醛含量和过氧化值为响应指标,通过进行单因素、主成分分析及Box-Benhnken响应曲面设计优化烤制猪肉腌制剂配方。结果表明,单因素实验中茶多酚对烤肉感官评分影响不显著。感官评分随大豆分离蛋白、大蒜和菜籽油添加量的加大,皆呈先升高后降低趋势,在三者分别为2%、5%和12%时最高。大豆分离蛋白和茶多酚抑制脂肪氧化效果优于大蒜和菜籽油,茶多酚和菜籽油能较好提升烤肉L值。主成分分析及Box-Benhnken响应曲面设计优化结果显示,各添加剂最佳添加量分别为大蒜4.8%、大豆分离蛋白2.0%、菜籽油12.0%,茶多酚0.03%,得到规范化综合评分0.95,与预测值0.98基本一致。该主成分分析和响应面设计优化的腌制剂配方对实际生产具有一定指导意义。

不同处理对槠叶齐茶树插穗生根成苗的影响

为了筛选适合茶树“二段法”育苗的生根剂和水培处理方案,提高生根效果,采用二因素随机区组试验设计和主成分分析法,研究生根剂处理、水培时间对槠叶齐茶树插穗生根成苗的影响。结果表明,不同处理茶树插穗生根成苗效果以处理2(150 mg/L的NAA浸泡插穗2 h,水培时间1 d)最佳,各项生长指标综合表现最为优异。本研究结果可为茶树工厂化育苗提供理论依据,适合在生产中推广应用。

基于委托代理的工程监理寻租行为博弈分析

在综合分析工程监理制度下业主、工程监理和承包商相互作用关系的基础上,根据公共寻租理论,分析了工程监理与承包商之间的寻租动机;基于委托—代理理论,运用博弈论的方法建立了业主、工程监理与承包商之间的三方博弈模型,并对工程监理与承包商之间的寻租行为进行了博弈分析;基于博弈分析结果,对有效治理工程监理和承包商之间的寻租活动提出了政策建议。

轻量级主机数据采集与实时异常事件检测方法研究

针对特征值匹配方法不能检测未知异常的缺点以及常驻采集代理占用大量系统资源的问题,提出一种主机数据采集和异常检测方法。采用智能化的移动代理实现主机数据采集,大幅度降低系统中数据采集代理的数量;结合实时异常检测的需求,采用主成分分析方法对所收集的主机信息进行维度约减,并采用聚类方法对降维后的数据进行聚类分析,挖掘其中的异常点;为消除随机异常点对检测结果的影响,采用基于连续时间窗口的主机异常检测方法实现主机异常的准确检测。实验结果表明:与传统方法相比,数据规模相当的情况下,所提方法的时间复杂度减少了50%以上,检测准确率达到了95%以上,适用于主机异常的实时检测。

生态文明建设中的利益相关者博弈研究

中央政府、地方政府、企业、公众等多元主体的协同建设,是推进生态文明建设的必然要求。文章首先基于委托-代理模型,探讨了生态文明建设中“中央政府-地方政府”的双方利益博弈,分别模拟了监督和不监督条件下中央政府对地方政府的最优激励以及地方政府的努力水平;其次,构建了“地方政府-企业-公众”完全信息静态博弈模型,分析了在生态文明建设过程中影响三方决策的关键因素;在此基础上,提出了中央政府、地方政府、企业和公众之间的内生化综合激励模型,为多元利益相关者协同参与生态文明建设提供参考建议。

基于主成分分析的温室番茄最佳有机肥与微生物菌剂配比

以温室冬春茬大果型番茄"金棚323"为试验材料,设置T_1(有机肥1.5t、微生物菌剂25kg、EM菌剂15L)、T_2(有机肥2.0t、微生物菌剂50kg、EM菌剂15L)、T_3(有机肥2.5t、微生物菌剂75kg、EM菌剂15L)、T_4(有机肥3.0t、微生物菌剂100kg、EM菌剂15L)、CK(仅施用有机肥4.0t)5个处理,主要测定单果质量、维生素C含量、可滴定酸含量、可溶性糖含量、可溶性固形物含量、糖酸比、固酸比、口感接受度8项指标,应用主成分分析法对番茄品质进行综合评价,并结合番茄产量作为番茄综合品质的评定指标,研究有机肥(沼液)减施,微生物菌剂增加对番茄品质的影响,明确温室番茄优质高效的有机肥与微生物菌剂配比。结果表明:不同处理间除可溶性固形物无显著差异外,其它处理均差异显著。其中,T_3处理的单果质量最大,为203.67g;T_2处理的维生素C最高,为37.04mg·(100g)^(-1);T_4处理的可滴定酸含量最高,为0.84%;T_2处理的可溶性糖含量最高,为89.78mg·g-1;T_2处理的糖酸比含量最高,为14.63;CK的固酸比最高,为10.38;T_2处理的口感接受度最好,为49.40。采用主成分分析方法对不同有机肥与微生物菌肥配比的供试番茄品种的单果质量、维生素C、可滴定酸、可溶性糖等8项品质指标进行了分析,将8个品质指标转化为3个主成分,代表主要品质性状遗传信息的90.412%的信息量。通过综合分析,明确T_2处理的综合得分最高。通过分析不同微生物菌剂施用量对番茄产量影响,明确T_4处理施用微生物菌剂最多,其产量最高。若仅考虑不同有机肥与微生物菌剂配比对产量的影响,则T_4处理的配比最佳;若考虑番茄的综合品质,则T_2处理的有机肥与微生物菌剂配比最适宜。

多任务委托工程监理激励机制设计

工程监理制度下的业主与工程监理之间的关系属于多任务的委托-代理关系。根据多任务委托-代理博弈分析,由于工程监理承担任务间努力成本的替代性,多任务委托-代理情况下的工程监理具有不同于单一任务委托-代理情况下的激励机制;为防止对工程监理激励效能的弱化,工程监理激励报酬制度应以客观绩效评价为主,并辅以主观绩效评价机制。

生物制剂对约书亚树幼苗成活及生理生化影响的综合评价

采用保水剂(处理Ⅰ)、生根粉(处理Ⅱ)、矮壮素(处理Ⅲ)与多效唑(处理Ⅳ)4种生物制剂,研究了不同生物制剂对2年生沙漠植物约书亚树幼苗的成活、生长及生理生化指标的影响,并对其影响效益作出综合评价。结果表明:处理Ⅰ及处理Ⅱ均能显著提高约书亚树幼苗的成活率,分别高于对照10.78%及5.43%,处理Ⅲ及处理Ⅳ较对照的成活率分别降低了15.78%及11.25%。处理Ⅰ显著促进了幼苗生长并提高了约书亚树幼苗的光合生理指标、渗透调节物质含量、POD酶及CAT酶活性。处理Ⅱ对幼苗株型无显著影响,抗氧化酶活性及脯氨酸含量均显著高于对照。处理Ⅲ使幼苗株高显著低于其他处理,并主要影响幼苗的游离脯氨酸含量及抗氧化酶活性指标。处理Ⅳ促进幼苗地径增粗和植株矮化,并影响植物的光合生理及SOD酶活性指标。利用主成分分析得出,约书亚树幼苗的株型及光合生理因子在综合评价中权重最大,为68.11%;D值的排序为:处理Ⅰ>处理Ⅳ>处理Ⅱ>对照>处理Ⅲ,说明保水剂为最佳生物制剂,显著提高了植物的成活率及生理生化指标,并能显著促进幼苗生长;其次为生根粉,通过影响渗透调节物质和抗氧化酶活性指标促使成活率显著提高;多效唑虽然对植物的影响效益较大,但其浓度可能不适宜植物成活,对其施用浓度需要进一步研究。

工程监理寻租行为博弈分析

在综合分析工程监理制度下业主、工程监理和承包商相互作用关系的基础上,根据公共寻租理论与委托—代理理论,分析了工程监理与承包商之间的寻租动机,并建立了业主、工程监理与承包商之间的三方博弈模型,通过对模型及博弈结果的分析,提出强化业主内部管理、提升对寻租行为的监督效率及加大对寻租活动的惩罚力度是减少工程监理中寻租行为的有效措施。