On the ternary spatial relation "between".

The spatial relation "between" is a notion which is intrinsically both fuzzy and contextual, and depends, in particular, on the shape of the objects. The literature is quite poor on this and the few existing definitions do not take into account these aspects. In particular, an object B that is in a concavity of an object A1 not visible from an object A2 is considered between A1 and A2 for most definitions, which is counter intuitive. Also, none of the definitions deal with cases where one object is much more elongated than the other. Here, we propose definitions which are based on convexity, morphological operators, and separation tools, and a fuzzy notion of visibility. They correspond to the main intuitive exceptions of the relation. We distinguish between cases where objects have similar spatial extensions and cases where one object is much more extended than the other. Extensions to cases where objects, themselves, are fuzzy and to three-dimensional space are proposed as well. The original work proposed in this paper covers the main classes of situations and overcomes the limits of existing approaches, particularly concerning nonvisible concavities and extended objects. Moreover, the definitions capture the intrinsic imprecision attached to this relation. The main proposed definitions are illustrated on real data from medical images.     

Exploring the relation between spatial structure and wavelength: Implications for sampling reflectance in the field

Recently, the variogram has been used to represent the spatial dependence in remotely sensed data obtained from ground-based, airborne and satellite-borne sensors. The variogram may be used in a variety of techniques such as kriging, cokriging, and conditional simulation and, in particular, optimal sampling design. However, little is known about the relation between spatial variation (summarized by the variogram) and spectral wavelength. Therefore, an investigation was undertaken to determine the relation between spatial dependence and wavelength for two field sites in England: one at Middlebere Heath on the Isle of Purbeck, Dorset, and the other at the Isle of Grain, Kent. At both sites, visible and near-infrared reflectance spectra comprising 252 wavebands were obtained using a Spectron SE-590TM spectroradiometer for 100 observations spaced 1m apart along 100m transects. Variograms were computed for 235 wavebands and these plotted as a three-dimensional surface. The resulting surfaces revealed changes with wavelength not only in the amount, but also in the scales of spatial variation. The spatial variation in all 235 wavelengths was approximately two-dimensional for both case studies. The implication for the design of optimal strategies with which to sample reflectance in the field is that two (and only two) sample spacings are necessary to sample all 235 wavebands.     

Hierarchical spatial relation based on a contiguity graph

Autonomous agents traversing a natural space need to be knowledgeable of its space configuration. The existing space models in geographic information systems and robotics, however, deal with only the topological relations among numerous types of spatial relations. We aim to develop an enhanced space model that elaborates the spatial relations with respect to their relevant physical relations. Specifically, the spatial relations in a space configuration are further characterized with the gravitation as a potential factor to affect the space configuration. The resulting space model is capable of capturing an extended set of spatial relations over existing models such as a four‐intersection model. © 2005 Wiley Periodicals, Inc. Int J Int Syst 20: 867–892, 2005.     

不同坐标系下空间两球体关系的安全判定协议

如何将处于不同空间坐标系下的几何对象统一到相同空间坐标系下是合作过程中经常遇到的问题,为了保证双方安全与利益,合作双方都希望不泄露自身的私有输入信息。针对以上情况,首先提出并设计了隐私保护的不同空间坐标系下的两点距离计算协议,然后进一步设计了保护隐私的不同空间坐标系下两球体关系的判定协议,分析了协议的正确性、安全性和复杂性。在保护参与方私有输入信息的条件下,所设计的协议解决了不同空间坐标系下球体与球体之间的相对位置安全判定问题。     

Quality evaluation of insulating parts by fusion of classifiers issued from tomographic images

The industrial manufacturing of insulating parts must meet strict requirements in order to be used in disturbed environments. Experts know that the moulding process has an impact on the final product quality. However, the phenomenon is so complicated that the relation between the manufacturing process and the product quality is difficult to identify. Some non-destructive methods are nowadays used in the industry to obtain information from inside the parts. In this paper, 3D tomographic acquisitions are used in order to analyse the parts. From the huge set of data obtained, several attributes have been computed to characterize images. A fusion system based on the Decision Templates method is proposed in this paper. Adaptations of the initial method are proposed to be more effective for image segmentation. The fusion approach capabilities are analysed on real data in the context of insulating part analysis.     

The relation between logic and functional languages: a survey

The paper considers different methods of integrating the functional and logic programming paradigms, starting with the identification of their semantic differences. The main methods to extend functional programs with logic features (i.e. unification) are then considered. These include narrowing, completion, SLD-resolution of equational formulas, and set abstraction. The different techniques are analyzed from several viewpoints, including the ability to support both paradigms, lazy evaluation, and concurrency.     

问题引导的空间关系图推理视觉问答模型

目的 现有视觉问答模型的研究主要从注意力机制和多模态融合角度出发,未能对图像场景中对象之间的语义联系显式建模,且较少突出对象的空间位置关系,导致空间关系推理能力欠佳。对此,本文针对需要空间关系推理的视觉问答问题,提出利用视觉对象之间空间关系属性结构化建模图像,构建问题引导的空间关系图推理视觉问答模型。方法 利用显著性注意力,用Faster R-CNN(region-based convolutional neural network)提取图像中显著的视觉对象和视觉特征;对图像中的视觉对象及其空间关系结构化建模为空间关系图;利用问题引导的聚焦式注意力进行基于问题的空间关系推理。聚焦式注意力分为节点注意力和边注意力,分别用于发现与问题相关的视觉对象和空间关系;利用节点注意力和边注意力权重构造门控图推理网络,通过门控图推理网络的信息传递机制和控制特征信息的聚合,获得节点的深度交互信息,学习得到具有空间感知的视觉特征表示,达到基于问题的空间关系推理;将具有空间关系感知的图像特征和问题特征进行多模态融合,预测出正确答案。结果 模型在VQA(visual question answering)v2...     

A recommendation framework for remote sensing images by spatial relation analysis

In recent years, Remote Sensing Images (RS-Images) are widely recognized as an essential geospatial data due to their superior ability to offer abundant and instantaneous ground truth information. One of the active RS-Image approaches is the RS-Image recommendation from the Internet for meeting the user's queried Area-of-Interest (AOI). Although a number of studies on RS-Image ranking and recommendation have been proposed, most of them only consider the spatial distance between RS-Image and AOI. It is inappropriate since both of the RS-Image and AOI not only have the spatial information but also the cover range information. In this paper, we propose a novel framework named Location-based rs-Image Finding Engine (LIFE) to rank and recommend a series of relevant RS-Images to users according to the user-specific AOI. In LIFE, we first propose a cluster-based RS-Image index structure to efficiently maintain the large amount of RS-Images. Then, two quantitative indicators named Available Space (AS) and Image Extension (IE) are proposed to measure the Extensibility and Centrality between RS-Image and AOI, respectively. To our best knowledge, this is the first work on RS-Image recommendation that considers the issues of extensibility and centrality simultaneously. Through comprehensive experimental evaluations, the experiment result shows that both indicators have their own distinguished ranking behaviors and are able to successfully recommend meaningful RS-Image results. Besides, the experimental results show that the proposed LIFE framework outperforms the state-of-the-art approach Hausdorff in terms of Precision, Recall and Normalized Discounted Cumulative Gain (NDCG).     

BendCad: a design system for concurrent multiple representations of parts

Concurrency in product design and manufacturing process planning is supported in a recently developed sheet metal design system that incorporates preliminary process design at the detail product design stage. This new design with process features approach represents the evolving part form to the designer in multiple process domains and at multiple stages of a sequential process. Each set of part form representations defines the conceptualized process that transforms it from one to the other. At this modeling level, processes are reversible so that design activity can take place in any of the domains and be transferred to the others. We have fully implemented this concept in a sheet metal design/manufacturing system in which preliminary process design occurs concurrently with product design and the normal representational ambiguities of wireframe and flat panel models are eliminated.     

PROCASE: a case-based process planning system for machining of rotational parts

This paper introduces a case-based process planning system PROCASE which generates new process routines through learning from existing process routines. In contrast to traditional rule-based systems, the process planning knowledge of the PROCASE is represented in terms of cases instead of production rules. The planning basically comprises case retrieving and case adaptation rather than chaining applicable rules together to form process plans. The advantages are, first, the system is cheaper to build as it saves the expense of knowledge acquisition. Second, the system is able to advance its knowledge automatically through planning practice. Third, it is robust, because the reasoning is not based on pattern matching but similarity comparison. PROCASE has three modules: the retriever, the adapter and the simulator. It is supported by a feature-based representation scheme which naturally serves as the case indices for case retrieving and adaptation. The retriever uses a similarity metric to retrieve an old case which is the most similar case, among all old ones, to the new case. The adapter is then activated to adapt the process plan of the retrieved case to fit the needs for the new case. The simulator is used to verify the feasibility of the adapted plan. PROCASE is implemented on a Silicon Graphics IRIS workstation using C++ . An example is given to demonstrate how the process routine is generated by the system proposed by the authors.     

Hypermedia navigation: Differences between spatial cognitive styles

Recently, many studies have investigated the role of individual and cognitive differences during Web navigation and Web searching. Despite this interest, no works have considered the role may assume individual differences in real-environment navigation during Web navigation. The aim of this work is to investigate the effect of different spatial cognitive styles: Landmark style (LS), Route style (RS) and Survey style (SS), on Web searching behaviour. In real-environment navigation, having a specific style determines the type of information individuals selected to navigate and orient themselves. We hypothesize that LS individuals are less proficient during Web exploration due to their analytical analysis of the environmental features. Vice versa SS individuals will show high performance on Web exploration for their holistic analysis of the World. We asked 30 College Students (10 LS, 10 RS, 10 SS) to solve three Web information tasks. The spatial cognitive style of participants was assessed through the Spatial Cognitive Style Test, and they were also asked to fill in a questionnaire about their internet and computer use. An ad hoc key-logger program for browsers was used to collect Web behaviour measures. In particular, the measures considered were: search engine tools used (e.g. back button), pages visited and revisited, time spent on information searching, and mouse cursor movements. The results showed significant differences between the spatial cognitive styles: LS seems to use a trial and error strategy in order to obtain the relevant information. Differences also emerged in the distribution of mouse cursor movements during Web navigation.     

UV-diagram: a voronoi diagram for uncertain spatial databases

The Voronoi diagram is an important technique for answering nearest-neighbor queries for spatial databases. We study how the Voronoi diagram can be used for uncertain spatial data, which are inherent in scientific and business applications. Specifically, we propose the Uncertain-Voronoi diagram (or UV-diagram), which divides the data space into disjoint “UV-partitions”. Each UV-partition $P$ is associated with a set $S$ of objects, such that any point $q$ located in $P$ has the set $S$ as its nearest neighbor with nonzero probabilities. The UV-diagram enables queries that return objects with nonzero chances of being the nearest neighbor (NN) of a given point $q$ . It supports “continuous nearest-neighbor search”, which refreshes the set of NN objects of $q$ , as the position of $q$ changes. It also allows the analysis of nearest-neighbor information, for example, to find out the number of objects that are the nearest neighbors of any point in a given area. A UV-diagram requires exponential construction and storage costs. To tackle these problems, we devise an alternative representation of a UV-diagram, by using a set of UV-cells. A UV-cell of an object $o$ is the extent $e$ for which $o$ can be the nearest neighbor of any point $q \in e$ . We study how to speed up the derivation of UV-cells by considering its nearby objects. We also use the UV-cells to design the UV-index, which supports different queries, and can be constructed in polynomial time. We have performed extensive experiments on both real and synthetic data to validate the efficiency of our approaches.     

SLOM: a new measure for local spatial outliers

We propose a measure, spatial local outlier measure (SLOM), which captures the local behaviour of datum in their spatial neighbourhood. With the help of SLOM, we are able to discern local spatial outliers that are usually missed by global techniques, like “three standard deviations away from the mean”. Furthermore, the measure takes into account the local stability around a data point and suppresses the reporting of outliers in highly unstable areas, where data are too heterogeneous and the notion of outliers is not meaningful. We prove several properties of SLOM and report experiments on synthetic and real data sets that show that our approach is novel and scalable to large datasets. Sanjay Chawla is a Senior Lecturer in the School of Information Technologies at the University of Sydney. His research interests span the area of data mining and spatial database management. He is a co-author of the textbook “Spatial Databases: A Tour”, which is published by Prentice Hall. His research work has appeared in leading publications, including IEEE Transaction on Knowledge and Data Engineering and GeoInformatica. He received his Ph.D. in Mathematics from the University of Tennessee, USA. Pei Sun is currently a Ph.D. student in the School of Information Technology, Sydney University, Australia. His research interests include data mining and spatial database. He received his M.E. degree from the University of New South Wales, Sydney, Australia, in 2002 and a B.E. degree from Beijing Forestry University, China, in 1990.     

CLARANS: a method for clustering objects for spatial data mining

Spatial data mining is the discovery of interesting relationships and characteristics that may exist implicitly in spatial databases. To this end, this paper has three main contributions. First, it proposes a new clustering method called CLARANS, whose aim is to identify spatial structures that may be present in the data. Experimental results indicate that, when compared with existing clustering methods, CLARANS is very efficient and effective. Second, the paper investigates how CLARANS can handle not only point objects, but also polygon objects efficiently. One of the methods considered, called the IR-approximation, is very efficient in clustering convex and nonconvex polygon objects. Third, building on top of CLARANS, the paper develops two spatial data mining algorithms that aim to discover relationships between spatial and nonspatial attributes. Both algorithms can discover knowledge that is difficult to find with existing spatial data mining algorithms.     

A geometrical and physical nonlinear finite element model for spatial thin-walled beams with arbitrary section

Based on the theories of Bernoulli-Euler beams and Vlasov's thin-walled members,a new geometrical and physical nonlinear beam element model is developed by applying an interior node in the element and independent interpolations on bending angles and warp,in which factors such as traverse shear deformation,torsional shear deformation and their coupling,coupling of flexure and torsion,and second shear stress are all considered.Thereafter,geometrical nonlinear strain in total Lagarange(TL) and the correspondin...     

A morphologically optimal strategy for classifier combination: multiple expert fusion as a tomographic process

We specify an analogy in which the various classifier combination methodologies are interpreted as the implicit reconstruction, by tomographic means, of the composite probability density function spanning the entirety of the pattern space, the process of feature selection in this scenario amounting to an extremely bandwidth-limited Radon transformation of the training data. This metaphor, once elaborated, immediately suggests techniques for improving the process, ultimately defining, in reconstructive terms, an optimal performance criterion for such combinatorial approaches.     

On the relation between a fuzzy number and its centroid

In this paper we answer the following question: if the centroid and the left/right spread of an unknown fuzzy number are given how do we find this fuzzy number?     

Building spatial temporal relation graph of concepts pair using web repository

Mining semantic relations between concepts underlies many fundamental tasks including natural language processing, web mining, information retrieval, and web search. In order to describe the semantic relation between concepts, in this paper, the problem of automatically generating spatial temporal relation graph (STRG) of semantic relation between concepts is studied. The spatial temporal relation graph of semantic relation between concepts includes relation words, relation sentences, relation factor, relation graph, faceted feature, temporal feature, and spatial feature. The proposed method can automatically generate the spatial temporal relation graph (STRG) of semantic relation between concepts, which is different from the manually generated annotation repository such as WordNet and Wikipedia. Moreover, the proposed method does not need any prior knowledge such as ontology or the hierarchical knowledge base such as WordNet. Empirical experiments on real dataset show that the proposed algorithm is effective and accurate.     

Mechanical parts orienting: The case of a polyhedron on a table

The positioning and orienting of parts is a standard problem in manufacturing. Orienting parts is often a prelude to the assembly of parts at tight tolerances. This paper considers the problem of orienting a part resting on a table, by tilting the table. The initial orientation of the part is assumed to be completely unknown. The objective is to tilt the table in a manner that reduces the uncertainty in the part's orientation. This paper focuses on three-dimensional polyhedral parts, with infinite friction between the parts and the table, and for which all transitions between different face-table contacts may be regarded as rotations across edges. The paper proposes a planner that determines a sequence of tilting operations designed to minimize the uncertainty in the part's orientation. The planner runs in timeO(n ³), wheren is the number of faces of the polyhedron. The planner produces a sequence ofO(n) distinct tilting operations. Each tilting operation wobbles the table until the part is in steady state.This research was supported, through the Leonardo Fibonacci Institute, by the Istituto Trentino di Cultura, Trento, Italy. Additional support for M. Erdmann was provided by Carnegie Mellon University and by NSF Grant IRI-9010686, additional support for M. Mason was provided by Carnegie Mellon University, and additional support for G. Vanek was provided by NSF Grant CCR-86-19817 to Purdue University.