共查询到20条相似文献，搜索用时 31 毫秒
1.
2.
An approach based on hybrid semantic model (HSM) was proposed to the solve problem raised in the retrieval process of product knowledge documentation. It expands the traditional user query to a semantic set composed of user preference, context and query, while representing the knowledge documents and user interest with an ontology based fuzzy concept. The leaves in the ontology are selected as components of the document concept vector with the weight determined by the depth of the concept in the ontology graph, the quantity of the information contained, and occurrence in the document and the whole repository. Furthermore, ontology is used to express context and query, and to construct a user preference model. Different relevancy computation methods are adopted for different retrieval models. The semantic similarity between query or user preference and documentation is computed by cosine method. The semantic similarity of context is estimated by the concept distance in the concept hierarchy. Finally, the method is shown by experimentation to be more effective than the classic vector space method. 相似文献
3.
Segmentation Ambiguity is an important factor influencing accuracy of Chinese auto-segmentation system. Time words include expressions both indicating exact time positions and those scattering in a treriod of time. On the foundations of modern Chinese corpus processing principles and certain type time word segmentation ambiguity, this paper proposes problem, a statistical language model and corresponding approach based on maximum likelihood to solve the ambiguous and it reaches a 90% accuracy which shows the effectiveness of the algorithm. 相似文献
4.
针对在水果表面品质检测的图像处理中,苹果的果梗和花萼很容易被错误辨识成缺陷,提出一种自动识别出苹果缺陷,并计算其大小的图像处理算法,如图像分割、图像去噪、区域标记与提取、感兴趣区域提取等,设计出一种能将采集到的苹果图片进行正确处理后,识别出果梗和花萼,得到真正缺陷大小的图像处理算法。运用C++语言进行编程,采用MFC基于对话框的非模态形式设计了图像处理软件,处理采集到的苹果样品图片,结果表明,该算法能正确计算缺陷大小,并且能得到果梗和花萼的辨识依据,可用于水果表面品质实时检测中。 相似文献
5.
ABSTRACT Canadian poverty rates have persisted at disappointingly high levels despite almost 15 years of continuous economic growth. The problem is exacerbated by some communities and neighborhoods having exceedingly high poverty, including very high rates for vulnerable demographic groups, such as aboriginals and recent immigrants. We investigate low‐income rates (poverty rates) for 2,400 Canadian “communities” over the 1981–2001 period. By focusing on communities, we fill a void in the related Canadian literature, which tends to focus on individuals, case studies, or more aggregate measures, such as provinces. Our approach allows us to assess the role of place‐based policies. Particular attention is given to communities with differing shares of aboriginal Canadians and recent immigrants. One novel feature is our analysis of both “short‐term” and “long‐term” causes of differential community poverty rates. The results suggest that community low‐income rates are more affected by initial economic conditions in the short term, with certain demographic factors becoming relatively more important in the long run. 相似文献
6.
The acquisition of physiological signals is the first step of its analysis and processing. The development mode for PC/104 module is introduced and the design of multichannel acquisition system for physiological signals based on PC/104 is also put forward. The system hardware mainly includes PC/104 embedded computer,DIAMOND-MM-16-AT acquisition card and four-channel amplifiers. Windows 2000 is used as operating system for PC/104 embedded computer. The multithread program to sample data is made by means of programming language Visual C++ 6.0. The experimental results show that the system can be applied to sample, analyse, and process the physiological signals. The system also has lots of advantages, such as small volume, low power, firm structure and steady performance. 相似文献
7.
Dendriform connections of concrete filled steel rectangular tubes (CFSRT) are composed of a bifurcated column and double cruciform beam column connections. A 3 D nonlinear finite element analysis (FEA) which considers all nonlinear effects of materials, geometry and contact interfaces is established. Analysis of the FEA results show that the load displacement curves at the ends of the beam and hysteretic curves obtained experimentally and via FEA agreed with each other. The stiffener transfers the tension compression stress efficiently, the middle hole has little influence on the stress transfer, and the compressive zone of the core concrete under repeated loading has a greater contribution to the compression stress transfer. 相似文献
8.
Rebecca H. Bilous 《Asia Pacific viewpoint》2015,56(3):365-379
Yol?u people living in northeast Arnhem Land regularly celebrate their connections with the Macassan trepangers from Indonesian Sulawesi in storytelling, art and music. The history of this contact is well known in academic literature, and these stories of Macassan contact are told regularly by Yol?u people to tourists visiting northeast Arnhem Land. This paper explores the impact that hearing stories about the Macassans from one Yol?u family's tourism business had on a group of Australian Indonesian language teachers, visiting as part of an Endeavour Language Teaching Fellowship. It draws on ideas related to telling and hearing stories and argues that these particular stories enabled the teachers to make powerful connections: with each other and with Australia's histories and geographies. The paper also explores the ways in which the teachers went on to become storytellers themselves, using stories to make connections in their students' learning. 相似文献
9.
China’s specialized markets as a special form of bottom-up capital agglomeration have played a key role in fostering regional development. It once exhibited positive externalities with high efficiencies. However, given the rapid proliferation of specialized markets and the penetration of E-commerce, their advantages may have shifted and the understanding of this shift is limited. The paper explores the spatio-temporal dynamics of China’s specialized markets in terms of technical efficiency. Based on turnover data from Statistical Yearbooks of China Commodity Exchange Market from 2000 to 2016, technical efficiencies in specialized markets are measured by a Stochastic Frontier Analysis (SFA) approach using panel data. The results show that (a) the technical efficiencies in China’s specialized markets are significantly divergent in space over time; (b) labor input has notable effect on efficiency increase, while capital input has no significant effect; (c) informatization level, cluster size, and degree of market openness are identified to have a positive effect on specialized market’s technical efficiency. This paper argues that specialized markets should be taken seriously in the cluster evolution research. The role of proximity and the bounded links between specialized markets and their local clusters is the key to understanding their changing forms, performances, and trajectories. 相似文献
10.
The behavior and strength of tube gusset connections with tube 219×6 and 1/4 annular ribbed plate subjected to eccentric force is investigated. Non dimensionalized ultimate strength interaction relations between the wall moment of tube ,vertical axial force ,and eccentric vertical component force of axial brace force of tube gusset connections with 1/4(1/2) and annular ribbed plate subjected to eccentric force is researched based on the model of equivalent forces of tubular joint. The parameters which influence the ultimate strength of tube gusset joint were analyzed and non dimensionalized ultimate strength interaction relationships were proposed. It is shown that the proposal formula has theoretical and practical significance for design because of comparation with experimentation. 相似文献
11.
A novel double ring plate gear reducer (DRPGR) is designed and its experimental validation is conducted. By using the closed graph method, the modification coefficients of internal gearing in DRPGR are determined. Based on this, the overall structure of the reducer is designed and its kinematics simulation is achieved. With APDL programming language of ANSYS, a 3D finite element (FE) model of DRPGR is established, and its modal analysis and loaded tooth contact analysis (LTCA) are conducted respectively. The modal analysis reveals that the lower natural frequencies of DRPGR are much higher than the input frequency and the lower modes can be classified as vertical and horizontal bending of input and output shafts. The LTCA indicates that three pairs of gear teeth contact simultaneously at rated output torque. Due to the multi teeth contacts, the maximum stress is much lower than the permissible stress of internal gearings. The experimental tests of the prototype validate that DRPGR is adapted to both single driven and dual driven work condition. When single droved, DRPGR can eliminate the kinematic uncertainty by non 180 degree phase difference design. DRPGR claims a better dynamic performance in dual driven work condition. The efficiency of DRPGR increases with the increment of output torque and the reducer has an excellent short term overloaded capacity. The experimental results validate that the proposed method can be used to guide the design of that kind of reducer. 相似文献
12.
不同调控措施和施肥方法对烤烟产质量的影响 总被引：1，自引：1，他引：0
由于石林地区的高海拔会减缓烤烟生长周期中的前期生长速度。为此,通过实验,采用不同生长调节剂和施肥方法分析其对烤烟生育期、农艺性状和经济性状等的影响,从而探究提高烤烟生长速度的方法。实验结果表明：在大田生育期,进行水杨酸+生根粉+营养土拌塘+腐殖酸处理烟株的团棵期、旺长期均比对照实验提前4天;在农艺性状方面,经过水杨酸+生根粉+营养土拌塘+腐殖酸处理的烟株的株高、茎围方面都极显著高于对照实验烟株;在经济性状方面,进行水杨酸+生根粉+营养土拌塘+腐殖酸处理的烟株在产量、产值、上等烟比例及中上等烟比例方面,都极显著高于对照实验。因此,采用实验方法在一定程度上可以提升该地区烤烟的产质量。 相似文献
13.
Traditional model of distribution networks mostly research the response of input excitation, by describing elements and connections of elements for distribution networks. When the states of vertexes in distribution networks have changed, the connections of elements transformation. Owning to the mutual couplings and branches of distribution networks, it is hard to achieve the global optimization for load balancing, reconfiguration and restoration after fault by nomograph. A new model based on hierarchical model is presented. This model can be employed to identify the zone and branches efficiently and offer a cogent topological analysis method for the global optimization. The test result shows the effectiveness of the proposed method. 相似文献
14.
Under the action of lateral forces and vertical loads, the connection of reinforced concrete slab-column structure will not only transfer significant shear forces, but also unbalanced moment. As to the edge slab-column connection, even if there is no later force, it will also transfer unbalanced moment due to the asymmetry. Currently, most tests and studies focus on interior connections, but there are few tests or studies on edge slab-column connections. A relatively new type of shear reinforcement named shear-stud reinforcement was applied in edge column-slab connections and study on the seismic behavior of these connections was conducted. Tests and finite element analysis of three full-scale reinforced concrete edge slab-column connections subjected to gravity and unbalanced moment were completed in this paper, and main conclusions were as following: the bearing capacity, deformation capacity and seismic behavior of connections reinforced with shear-stud reinforcement are improved; deformation of specimens reinforced with shear-stud reinforcement could meet requirements of current codes; the performance of energy dissipating is as good as the common connections, and has reached the medium ductility level. 相似文献
15.
The mountain hazards like snow avalanches, landslides, rock falls, debris flows and so on all have strong power of destruction which seriously threaten human’s lives and belongings. Therefore, it is necessary to study more the development of these disasters in order to prevent them. Setting up obstacles is the primary measure to control the movement and deposition process of mountain hazards. For the study of the influence of this measure on the development of disasters, the numerical simulation calculation aiming at the flow and deposition process of the granulars flowing past different built obstacles was made by the theory of SH granular flow and the method of finite volume discretization based on Roe's Scheme. Futhermore, the influence of different settings of obstacles on the granular flow is discussed. The numerical results show that the settings of obstacles have a great effect on the process of granular flow. That is, the effective precaution against the disasters is no other than setting up the obstacles correctly. As the numerical simulation calculation can optimize the setting of obstacle, it provides a reasonable and economic reference scheme of disaster prevention and planning of mountain area. 相似文献
16.
为了探究农产品加工业的发展质量和发展差异、加快新疆农产品加工业快速健康发展,基于2015—2018年的面板数据,运用基于对数柯布-道格拉斯生产函数的随机前沿分析模型测算农产品加工业生产技术效率。研究表明,固定资产、从业人员均对全疆农产品加工企业技术效率的增长有显著影响,但当前整体生产效率仍较低。五大类型、14个地区的农产品加工企业技术效率均呈现逐年提高、差异较大、差距逐年缩小的特征。五大类型中,市场流通型技术效率最高,为0.947;畜牧产品加工企业最低,为0.483。14个地区中,乌鲁木齐市最高,为0.991;和田地区最低,为0.134。新疆农产品加工企业技术效率逐年增长得益于固定资产和劳动力投入,当前应以畜产品和林果产品加工业为重点行业,以吐鲁番市、哈密市、和田地区为重点区域,优化生产要素配置,推动农产品加工业由主要依靠要素投入和资源消耗向依靠科技进步和提高劳动者素质转变。 相似文献
17.
Richard Le Heron 《Asia Pacific viewpoint》2007,48(1):26-40
Abstract: The paper argues that post‐structural political economy (PSPE) offers geography and geographers interesting potential for the development of a style of geographic inquiry that has qualities that may be constitutive of progressive spaces. This new style of inquiry is seen as adding to the repertoire of political strategies and potential geographies of responsibility and extending notions of ethical behaviours. Issues relating to the assemblage of PSPE as a distinctive approach to knowledge production are considered and situated in the Australasian context. Discussion focuses especially on insight about the use of PSPE derived from three illustrative research case studies (a project on learning challenges in sheep meat and dairy supply chain realignment, tensions around fisheries management in New Zealand and an international workshop series on the topic of governmentality). The case studies provide a lens on the socio‐spatial relationships between globalisation and governance and interrogate the value of PSPE for understanding the connections between individual choices, governing practices and the construction of the globalising economy. The PSPE approach if actively incorporated into research processes may have important implications for future relationships between social responsibility, national economic development and globalisation. 相似文献
18.
M. Hühn 《Journal of Agronomy and Crop Science》2001,187(4):241-250
In this study a stochastic approach, based on several simplifying assumptions, is developed that allows an estimation of the effects of nonregular spatial patterns of the distribution of individual plants on yield per area. In this approach, two random variables were attached to each individual plant: single plant yield and individual space per plant. The latter can be estimated, for example, by the area of Thiessen polygons. Yield per area is calculated theoretically by the expectation (=mean) of the ratio between individual yield and area. Based on the logarithmic relationship between single plant yield and individual space per plant, yield per area can be broken down into three additive terms: the first term depends only on the mean of individual plant areas, while the second depends on their mean and variance simultaneously. This second term is the product of the variance and a factor which depends only on the mean. The third term is a function of the mean and of higher order (≥ 3) central moments of a fractional linear transformation of individual plant area. Finally, these theoretical concepts were applied to 17 experimental data sets of three cultivars of winter oilseed rape (Brassica napus L.) with measurements for single plant yields and individual areas for the Thiessen polygon tesselations. Since yield per area is theoretically defined by the expectation of the ratio between individual yield and area, it is estimated by the arithmetic mean of the individual yield/area‐ratios. The agreement between this estimate and the sum of the estimated terms from the aforementioned additive decomposition of yield per area is particularly good. For the 17 data sets, percentages for these additive terms of approximately 71.4 % up to 98.4 % (mean: 89.0 %) for the first term, 1.6 % up to 20.0 % (mean: 9.8 %) for the second term and 0 % up to 8.7 % (mean: 1.2 %) for the third term are obtained. As a consequence it may be concluded, that yield per area can be explained mainly by dependencies on the means of individual plant areas while the variance of individual plant spaces is of only minor importance. The effect of the third term is insignificant. These results clearly indicate an answer to the main issue raised in the paper, namely the importance of seeding density as opposed to seeding accuracy/uniformity: nonuniformity is of limited influence and seeding density is the main correlate of yield/area. Seed placement accuracy of seeding technology therefore plays an only minor role. 相似文献
19.
摘要： 为解决城乡收入差距的问题,基于农村金融发展对城乡收入差距的影响研究,以宁夏地区为例,分析农村金融发展对城乡收入差距的影响。选择4种方法,对宁夏地区农村金融发展和城乡收入差距之间的关系进行实证分析。得出金融运转效能对于城乡所得差异的支撑率最大至近5%,而农村金融运转体量对于城乡所得差异的支撑率相对降低,最高达到1.29%。在其他控制变量中,大约有0~4.5%的波动可以由城市化水平解释,财政支农支出可以解释0~3.5%的波动。说明短时间内农村金融运转体量与金融运转效能的升高会减小城乡所得差异,长时间内城乡所得差异表现为波动性,而城市化指标、财政支出指标、农村特定财产投入在短期内可以缩小城乡收入差距,如果长期受到这些因素的影响,则会产生更加重要的作用。结合以上分析结果,提出完善宁夏农村金融体系、完善农村金融流动机制、加大政策性金融支农的对策建议。 相似文献
20.
Landsat-8能够提供15 m全色波段和30 m分辨率的多光谱波段,Landsat-8上携带有OLI（operational land imager,陆地成像仪）和TIRS（thermal infrared sensor,热红外传感器）2个主要载荷,OLI陆地成像仪包括9个波段,TIRS包括2个热红处波段,全色波段Band8波段范围较窄,这种方式可以在全色图像上更好区分植被和无植被特征。本研究以攸县为例,采用Landsat-8遥感影像为数据源,进行缨帽变换及主成分分析处理,利用决策树分类模型进行提取。结果表明：Landsat-8遥感数据经过缨帽变换和主成分分析处理后,增强纹理信息,突出各地物的特征,把各地物在经过处理后的灰度值作为决策树分类模型的阈值,利用计算机自动提取,提取的总体精度为84.7%,攸县森林植被的面积为150911.7 hm2与以往的只利用波段的灰度值及植被指数等作为阈值相比,精度明显提高,方法也得到改善,得到了比较好的提取结果。 相似文献