数字图书馆的信息获取

当前的数字图书馆(DLs)主要支持基于关键字的查询和浏览,所以从研究问题到关键字的变换、主题与研究问题是否有关,完全由用户来决定.为增强当前DLs的功能,提出一个两层的数字图书馆模型,用以支持不同层次的人们的认识活动,从而在不同的用户之间交换新的信息.模型的下层除完成查询和浏览外,为用户提供对相关文档的请求;模型的上层不仅为用户提供相关文档,而且直接、智能地回答用户的认知问题.     

Shelves from bits [digital libraries]

Digital library is a broad term traditionally describing an online archive of documents. With the emergence of the Internet and Web, the concept of a digital library finally found its raison d'etre, and so today just about every academic institution and publisher on the planet is planning, or has implemented, some form of Web-based archive. The author looks at how the digital library concept today is useful not only to publishers but also for anyone wanting to create an online information archive     

Digital libraries

The history of modern information processing and the technology underlying it is reviewed. The development of hypertext is examined. Current technology and current efforts to expand information processing are discussed. The future of digital libraries is outlined     

Learning from the future of component repositories

An important aspect of the quality assurance of large component repositories is to ensure the logical coherence of component metadata, and to this end one needs to identify incoherences as early as possible. Some relevant classes of problems can be formulated in term of properties of the future repositories into which the current repository may evolve. However, checking such properties on all possible future repositories requires a way to construct a finite representation of the infinite set of all potential futures. A class of properties for which this can be done is presented in this work.We illustrate the practical usefulness of the approach with two quality assurance applications: (i) establishing the amount of “forced upgrades” induced by introducing new versions of existing components in a repository, and (ii) identifying outdated components that are currently not installable and need to be upgraded in order to become installable again. For both applications we provide experience reports obtained on the Debian free software distribution.     

Collaborative eScience libraries

In the context of collaborative eScience, digital libraries are one of many distributed, interoperable resources available to scientists that facilitate both human and machine collaboration: machine collaboration in the form of standards such as the Open Archives Initiative Protocol for Metadata Harvesting and human collaboration in the form of collaborative workspaces. This paper describes a set of collaborative workspaces created at the Los Alamos National Laboratory Research Library, initial patterns of use, and additional user requirements determined based on these initial patterns of use.     

Towards k-vertex connected component discovery from large networks

World Wide Web - In many real life network-based applications such as social relation analysis, Web analysis, collaborative network, road network and bioinformatics, the discovery of components...     

Synthesis from hyperproperties

We study the reactive synthesis problem for hyperproperties given as formulas of the temporal logic HyperLTL. Hyperproperties generalize trace properties, i.e., sets of traces, to sets of sets of traces. Typical examples are information-flow policies like noninterference, which stipulate that no sensitive data must leak into the public domain. Such properties cannot be expressed in standard linear or branching-time temporal logics like LTL, CTL, or $$\hbox {CTL}^*$$. Furthermore, HyperLTL subsumes many classical extensions of the LTL realizability problem, including realizability under incomplete information, distributed synthesis, and fault-tolerant synthesis. We show that, while the synthesis problem is undecidable for full HyperLTL, it remains decidable for the $$\exists ^*$$, $$\exists ^*\forall ^1$$, and the $${{ linear }}\;\forall ^*$$ fragments. Beyond these fragments, the synthesis problem immediately becomes undecidable. For universal HyperLTL, we present a semi-decision procedure that constructs implementations and counterexamples up to a given bound. We report encouraging experimental results obtained with a prototype implementation on example specifications with hyperproperties like symmetric responses, secrecy, and information flow.     

Building large-scale digital libraries

In this era of the Internet and the World Wide Web, the long-time topic of digital libraries has suddenly become white hot. As the Internet expands, particularly the WWW, more people are recognizing the need to search indexed collections. The paper discusses some of the Digital Library Initiative (DLI) projects which are a good measure of the research into large scale digital libraries. They span a wide range of the major topics necessary to develop the National Information Infrastructure     

Automation in American libraries

Despite its concentration on technical developments in library science, this survey is offered here because it is relevant to humanists for two reasons: first, that humanists all use libraries and therefore need to encourage their evolution to higher levels of efficiency, and, second, that the procedures outlined here may be of help to humanists in establishing procedures for their own research.     

Computation of component image velocity from local phase information

We present a technique for the computation of 2D component velocity from image sequences. Initially, the image sequence is represented by a family of spatiotemporal velocity-tuned linear filters. Component velocity, computed from spatiotemporal responses of identically tuned filters, is expressed in terms of the local first-order behavior of surfaces of constant phase. Justification for this definition is discussed from the perspectives of both 2D image translation and deviations from translation that are typical in perspective projections of 3D scenes. The resulting technique is predominantly linear, efficient, and suitable for parallel processing. Moreover, it is local in space-time, robust with respect to noise, and permits multiple estimates within a single neighborhood. Promising quantiative results are reported from experiments with realistic image sequences, including cases with sizeable perspective deformation.     

Procedure-based component and architecture modeling from a single image

This paper advocates a new component-aware framework to reconstruct 3D architecture from a single image. Different from existing work, our motivation is to obtain a complete set of semantically correct 3D architectural components, which enables part reusability towards rapid model reproduction and facilitates model variation. The core of our system is a novel algorithm to adaptively segment repeated curved stripes (e.g., roof tiles, building floors) into individual elements, based on which 3D dimensions as well as architectural components are derived from a single image. Specially for Chinese architectures, we further devise an interactive method to identify outer columns based on user-specified inner columns. Finally, 3D components are generated and shape rules are derived, from which the buildings and their variants are constructed. Our new component-aware framework minimizes the use of data resource (i.e., one single image) and emphasizes component utility during rapid 3D architecture reproduction by advocating a component-aware approach.     

Synthesis from scenario-based specifications

We consider the problem of the automatic generation of reactive systems from specifications given in the scenario-based language of live sequence charts (LSCs). We start by extending the language so that it becomes more suitable for synthesis. We then translate a system specification given in the language into a two-player game between the system and the environment. By solving the game, we generate a winning strategy for the system, which corresponds to a correct implementation of the specification. We also define two notions of system correctness, and show how each can be synthesized.     

Integrated use of case libraries

Case-based reasoning is now a well-explored method for intelligent problem solving. It has great potential for engineering applications, particularly for those related to reuse and redesign. However, to make it practically useful, an important technical problem to be solved is how to realize the integrated use of existing case libraries. In this paper, we first give an overview of case-based reasoning, then outline our methodology which leads to a distributed case library in a network environment. We explain how the indexing and retrieval techniques as used in “conventional” case libraries can be extended. An experimental system is described, and the relationship between our work and an object-oriented paradigm, as well as the relationship between our work and distributed artificial intelligence are also briefly examined.     

Simulation libraries for system-level design

Raising the level of design abstraction to achieve a system synthesis capability requires electronic design automation (EDA) tools for design capture, analysis and verification at the new level of abstraction, as well as tools for synthesis at the next lower level of abstraction. It is essential that simulation libraries exist that support the new toolset. In system synthesis, elements of the desired product functionality will be specified as combinations of functional primitives in a high-order language or as flowgraph representations. Implementation trade offs will require the designer to simulate the performance of these functions when implemented in ASICs, FPGAs, or software. Simulation will require extensive libraries of primitives and their performance characteristics on a wide variety of hardware and software implementations. The paper considers system synthesis and some problems in system-level simulation     

Efficient computation of new extinction values from extended component tree

A gray-scale image can be interpreted as a topographical surface, and represented by a component tree, based on the inclusion relation of connected components obtained by threshold decomposition. Relations between plateaus, valleys or mountains of this relief are useful in computer vision systems. An important definition to characterize the topographical surface is the dynamics, introduced by Grimaud (1992), associated with each regional minimum. This concept has been extended, by Vachier and Meyer (1995), by the definition of extinction values associated with each extremum of the image. This paper proposes three new extinction values - two based on the topology of the component tree: (i) number of descendants and (ii) sub-tree height; and one geometric: (iii) level component bounding box (subdivided into extinctions of height, width or diagonal). This paper describes an efficient computation of these extinction values based on the incremental determination of attributes from the component tree construction in quasi-linear time, compares the computation time of the method and illustrates the usefulness of these new extinction values from real examples.