共查询到20条相似文献,搜索用时 15 毫秒
1.
This paper proposes a new hand-held device called “InfoPoint” that allows appliances to work together over a network. We
have applied the idea of “drag-and-drop” operation as provided in the GUIs of PC and workstation desktop environment. InfoPoint
provides a unified interface that gives different types of appliances “drag-and-drop”-like behaviour for the transfer of data.
Moreover, it can transfer data from/to non-appliances such as pieces of paper. As a result, InfoPoint allows appliances to
work together, in the real-world environment, in terms of data transfer. A prototype of InfoPoint has been implemented and
several experimental applications have been investigated. InfoPoint has shown its applicability in a variety of circumstances.
We believe that the idea proposed in this paper will be a significant technology in the network of the future. 相似文献
2.
Henry S. Baird Allison L. Coates Richard J. Fateman 《International Journal on Document Analysis and Recognition》2003,5(2-3):158-163
Abstract. We exploit the gap in ability between human and machine vision systems to craft a family of automatic challenges that tell
human and machine users apart via graphical interfaces including Internet browsers. Turing proposed [Tur50] a method whereby
human judges might validate “artificial intelligence” by failing to distinguish between human and machine interlocutors. Stimulated
by the “chat room problem” posed by Udi Manber of Yahoo!, and influenced by the CAPTCHA project [BAL00] of Manuel Blum et
al. of Carnegie-Mellon Univ., we propose a variant of the Turing test using pessimal print: that is, low-quality images of machine-printed text synthesized pseudo-randomly over certain ranges of words, typefaces,
and image degradations. We show experimentally that judicious choice of these ranges can ensure that the images are legible
to human readers but illegible to several of the best present-day optical character recognition (OCR) machines. Our approach
is motivated by a decade of research on performance evaluation of OCR machines [RJN96,RNN99] and on quantitative stochastic
models of document image quality [Bai92,Kan96]. The slow pace of evolution of OCR and other species of machine vision over
many decades [NS96,Pav00] suggests that pessimal print will defy automated attack for many years. Applications include `bot'
barriers and database rationing.
Received: February 14, 2002 / Accepted: March 28, 2002
An expanded version of: A.L. Coates, H.S. Baird, R.J. Fateman (2001) Pessimal Print: a reverse Turing Test. In: {\it Proc.
6th Int. Conf. on Document Analysis and Recognition}, Seattle, Wash., USA, September 10–13, pp. 1154–1158
Correspondence to: H. S. Baird 相似文献
3.
Scott D. Stoller 《Distributed Computing》2000,13(2):85-98
Summary. This paper proposes a framework for detecting global state predicates in systems of processes with approximately-synchronized
real-time clocks. Timestamps from these clocks are used to define two orderings on events: “definitely occurred before” and
“possibly occurred before”. These orderings lead naturally to definitions of 3 distinct detection modalities, i.e., 3 meanings of “predicate held during a computation”, namely: (“ possibly held”), (“ definitely held”), and (“ definitely held in a specific global state”). This paper defines these modalities and gives efficient algorithms for detecting
them. The algorithms are based on algorithms of Garg and Waldecker, Alagar and Venkatesan, Cooper and Marzullo, and Fromentin
and Raynal. Complexity analysis shows that under reasonable assumptions, these real-time-clock-based detection algorithms
are less expensive than detection algorithms based on Lamport's happened-before ordering. Sample applications are given to
illustrate the benefits of this approach.
Received: January 1999 / Accepted: November 1999 相似文献
4.
We present a new approach to the tracking of very non-rigid patterns of motion, such as water flowing down a stream. The
algorithm is based on a “disturbance map”, which is obtained by linearly subtracting the temporal average of the previous
frames from the new frame. Every local motion creates a disturbance having the form of a wave, with a “head” at the present
position of the motion and a historical “tail” that indicates the previous locations of that motion. These disturbances serve
as loci of attraction for “tracking particles” that are scattered throughout the image. The algorithm is very fast and can
be performed in real time. We provide excellent tracking results on various complex sequences, using both stabilized and moving
cameras, showing a busy ant column, waterfalls, rapids and flowing streams, shoppers in a mall, and cars in a traffic intersection.
Received: 24 June 1997 / Accepted: 30 July 1998 相似文献
5.
Paolo Traverso Piergiorgio Bertoli 《International Journal on Software Tools for Technology Transfer (STTT)》2000,3(1):78-92
We present part of an industrial project where mechanized theorem proving is used for the validation of a translator which
generates safety critical software. In this project, the mechanized proof is decomposed in two parts: one is done “online”,
at each run of the translator, by a custom prover which checks automatically that the result of each translation meets some
verification conditions; the other is done “offline”, once for all, interactively with a general purpose prover; the offline
proof shows that the verification conditions checked by the online prover are sufficient to guarantee the correctness of each
translation. The provably correct verification conditions can thus be seen as specifications for the online prover. This approach
is called mechanized result verification. This paper describes the project requirements and explains the motivations to formal validation by mechanized result verification,
provides an overview of the formalization of the specifications for the online prover and discusses in detail some issues
we have addressed in the mechanized offline proof. 相似文献
6.
Design and analysis of a video-on-demand server 总被引:6,自引:0,他引:6
The availability of high-speed networks, fast computers and improved storage technology is stimulating interest in the development
of video on-demand services that provide facilities similar to a video cassette player (VCP). In this paper, we present a
design of a video-on-demand (VOD) server, capable of supporting a large number of video requests with complete functionality
of a remote control (as used in VCPs), for each request. In the proposed design, we have used an interleaved storage method
with constrained allocation of video and audio blocks on the disk to provide continuous retrieval. Our storage scheme interleaves
a movie with itself (while satisfying the constraints on video and audio block allocation. This approach minimizes the starting delay and the
buffer requirement at the user end, while ensuring a jitter-free display for every request. In order to minimize the starting
delay and to support more non-concurrent requests, we have proposed the use of multiple disks for the same movie. Since a
disk needs to hold only one movie, an array of inexpensive disks can be used, which reduces the overall cost of the proposed
system. A scheme supported by our disk storage method to provide all the functions of a remote control such as “fast-forwarding”,
“rewinding” (with play “on” or “off”), “pause” and “play” has also been discussed. This scheme handles a user request independent
of others and satisfies it without degrading the quality of service to other users. The server design presented in this paper
achieves the multiple goals of high disk utilization, global buffer optimization, cost-effectiveness and high-quality service
to the users. 相似文献
7.
ExploreNet is an experimental environment for creating and delivering networked “virtual worlds.” This system's style of user
interaction was inspired by the concept of a “habitat” as first articulated in the LucasFilm's Habitat system. Players enter
and interact in a habitat via their animated alter egos, called “avatars.” Habitats may be created for many purposes, including
social interaction, entertainment and education. Our focus has been to facilitate the creation of habitats in which virtual
communities of learners and mentors interact. This paper presents details of the current ExploreNet system, including its
user interface, the means it provides for creating complex behaviors, details of its implementation, the outcomes of several
experiments using this system, and our plans for its natural migration to a World Wide Web-based system. 相似文献
8.
Flip Korn Alexandros Labrinidis Yannis Kotidis Christos Faloutsos 《The VLDB Journal The International Journal on Very Large Data Bases》2000,8(3-4):254-266
Association Rule Mining algorithms operate on a data matrix (e.g., customers products) to derive association rules [AIS93b, SA96]. We propose a new paradigm, namely, Ratio Rules, which are quantifiable in that we can measure the “goodness” of a set of discovered rules. We also propose the “guessing
error” as a measure of the “goodness”, that is, the root-mean-square error of the reconstructed values of the cells of the
given matrix, when we pretend that they are unknown. Another contribution is a novel method to guess missing/hidden values
from the Ratio Rules that our method derives. For example, if somebody bought $10 of milk and $3 of bread, our rules can “guess”
the amount spent on butter. Thus, unlike association rules, Ratio Rules can perform a variety of important tasks such as forecasting,
answering “what-if” scenarios, detecting outliers, and visualizing the data. Moreover, we show that we can compute Ratio Rules
in a single pass over the data set with small memory requirements (a few small matrices), in contrast to association rule mining methods
which require multiple passes and/or large memory. Experiments on several real data sets (e.g., basketball and baseball statistics,
biological data) demonstrate that the proposed method: (a) leads to rules that make sense; (b) can find large itemsets in
binary matrices, even in the presence of noise; and (c) consistently achieves a “guessing error” of up to 5 times less than
using straightforward column averages.
Received: March 15, 1999 / Accepted: November 1, 1999 相似文献
9.
This paper presents a fast and simple method using a timed motion history image (tMHI) for representing motion from the gradients
in successively layered silhouettes. This representation can be used to (a) determine the current pose of the object and (b)
segment and measure the motions induced by the object in a video scene. These segmented regions are not “motion blobs”, but
instead are motion regions that are naturally connected to parts of the moving object. This method may be used as a very general
gesture recognition “toolbox”. We demonstrate the approach with recognition of waving and overhead clapping motions to control
a music synthesis program.
Accepted: 13 August 2001 相似文献
10.
Xiangyun Ye Mohamed Cheriet Ching Y. Suen 《International Journal on Document Analysis and Recognition》2001,4(2):84-96
The automation of business form processing is attracting intensive research interests due to its wide application and its
reduction of the heavy workload due to manual processing. Preparing clean and clear images for the recognition engines is
often taken for granted as a trivial task that requires little attention. In reality, handwritten data usually touch or cross
the preprinted form frames and texts, creating tremendous problems for the recognition engines. In this paper, we contribute
answers to two questions: “Why do we need cleaning and enhancement procedures in form processing systems?” and “How can we
clean and enhance the hand-filled items with easy implementation and high processing speed?” Here, we propose a generic system
including only cleaning and enhancing phases. In the cleaning phase, the system registers a template to the input form by
aligning corresponding landmarks. A unified morphological scheme is proposed to remove the form frames and restore the broken
handwriting from gray or binary images. When the handwriting is found touching or crossing preprinted texts, morphological
operations based on statistical features are used to clean it. In applications where a black-and-white scanning mode is adopted,
handwriting may contain broken or hollow strokes due to improper thresholding parameters. Therefore, we have designed a module
to enhance the image quality based on morphological operations. Subjective and objective evaluations have been studied to
show the effectiveness of the proposed procedures.
Received January 19, 2000 / Revised March 20, 2001 相似文献
11.
The paper investigates efficient bandwidth allocation schemes for the transmission of MPEG-2 video traffic on high-speed
networks. To this end we performed an extensive analysis of the traffic generated by an MPEG-2 encoder. Specifically, we encoded
“The Sheltering Sky” movie according to the MPEG-2 standard. By the analysis of the generated traffic it results that a constant-quality
transmission can be performed with a poor bandwidth utilization. In the paper we identified that the low bandwidth utilization
is caused by rare high-rate periods in the codec bitstream. Hence, we identified the source scalability as a promising approach
to achieve a “quasi-constant” quality transmission and an efficient bandwidth utilization. The effectiveness of this approach
is evaluated in the paper via simulation. Specifically, by defining a Markovian model for an MPEG-2 scalable source we performed
a set of simulation experiments which indicate that the source scalability approach significantly increases the utilization,
while maintaining the quality of the video signal at the highest value for most of the time, e.g., a 50% of the network utilization
with the highest quality for the 99.7% of the time. 相似文献
12.
Andrew Fano 《Personal and Ubiquitous Computing》2001,5(1):12-15
The promise of mobile devices lies not in their capacity to duplicate the capabilities of desktop machines, but rather in
their promise of enabling location-specific tasks. One of the challenges that must be addressed if they are to be used in
this way is how intuitive interfaces for mobile devices can be designed that enable access to location-specific services usable
across locations. We are developing a prototype mobile valet application that presents location-specific services organised
around the tasks associated with a location. The basic elements of the interface exploits commonalties in the way we address
tasks at various locations just as the familiar “file” and “edit” menus in various software applications exploit regularities
in software tasks. 相似文献
13.
David Gibson Jon Kleinberg Prabhakar Raghavan 《The VLDB Journal The International Journal on Very Large Data Bases》2000,8(3-4):222-236
We describe a novel approach for clustering collections of sets, and its application to the analysis and mining of categorical
data. By “categorical data,” we mean tables with fields that cannot be naturally ordered by a metric – e.g., the names of
producers of automobiles, or the names of products offered by a manufacturer. Our approach is based on an iterative method
for assigning and propagating weights on the categorical values in a table; this facilitates a type of similarity measure
arising from the co-occurrence of values in the dataset. Our techniques can be studied analytically in terms of certain types
of non-linear dynamical systems.
Received February 15, 1999 / Accepted August 15, 1999 相似文献
14.
Paul L. Rosin 《Machine Vision and Applications》1997,9(4):139-159
Edges are useful features for structural image analysis, but the output of standard edge detectors must be thresholded to
remove the many spurious edges. This paper describes experiments with both new and old techniques for: 1. determining edge
saliency (as alternatives to gradient magnitude) and 2. automatically determining appropriate edge threshold values. Some
examples of edge saliency measures are lifetime, wiggliness, spatial width, and phase congruency. Examples of thresholding
techniques use: the Rayleigh distribution to model the edge gradient magnitude histogram, relaxation labelling, and an edge
curve “length”–“average gradient magnitude” feature space. 相似文献
15.
S. Adam J.M. Ogier C. Cariou R. Mullot J. Labiche J. Gardes 《International Journal on Document Analysis and Recognition》2000,3(2):89-101
In this paper, we consider the general problem of technical document interpretation, as applied to the documents of the French
Telephonic Operator, France Télécom. More precisely, we focus the content of this paper on the computation of a new set of
features allowing the classification of multioriented and multiscaled patterns. This set of invariants is based on the Fourier–Mellin
Transform. The interests of this computation rely on the excellent classification rate obtained with this method and also
on using this Fourier–Mellin transform within a “filtering mode”, with which we can solve the well known difficult problem
of connected character recognition. 相似文献
16.
Christian Shin David Doermann Azriel Rosenfeld 《International Journal on Document Analysis and Recognition》2001,3(4):232-247
Searching for documents by their type or genre is a natural way to enhance the effectiveness of document retrieval. The layout
of a document contains a significant amount of information that can be used to classify it by type in the absence of domain-specific
models. Our approach to classification is based on “visual similarity” of layout structure and is implemented by building
a supervised classifier, given examples of each class. We use image features such as percentages of text and non-text (graphics,
images, tables, and rulings) content regions, column structures, relative point sizes of fonts, density of content area, and
statistics of features of connected components which can be derived without class knowledge. In order to obtain class labels
for training samples, we conducted a study where subjects ranked document pages with respect to their resemblance to representative
page images. Class labels can also be assigned based on known document types, or can be defined by the user. We implemented
our classification scheme using decision tree classifiers and self-organizing maps.
Received June 15, 2000 / Revised November 15, 2000 相似文献
17.
Restoring subsampled color images 总被引:1,自引:0,他引:1
In some capturing devices, such as digital cameras, there is only one color sensor at each pixel. Usually, 50% of the pixels
have only a green sensor, 25% only a red sensor, and 25% only a blue sensor. The problem is then to restore the two missing
colors at each pixel – this is called “demosaicing”, because the original samples are usually arranged in a mosaic pattern.
In this short paper, a few demosaicing algorithms are developed and compared. They all incorporate a notion of “smoothness
in chroma space”, by imposing conditions not only on the behavior of each color channel separately, but also on the correlation
between the three channels. 相似文献
18.
Xiaodong Wen Theodore D. Huffmire Helen H. Hu Adam Finkelstein 《Multimedia Systems》1999,7(5):350-358
We present several algorithms suitable for analysis of broadcast video. First, we show how wavelet analysis of frames of
video can be used to detect transitions between shots in a video stream, thereby dividing the stream into segments. Next we
describe how each segment can be inserted into a video database using an indexing scheme that involves a wavelet-based “signature.”
Finally, we show that during a subsequent broadcast of a similar or identical video clip, the segment can be found in the
database by quickly searching for the relevant signature. The method is robust against noise and typical variations in the
video stream, even global changes in brightness that can fool histogram-based techniques. In the paper, we compare experimentally
our shot transition mechanism to a color histogram implementation, and also evaluate the effectiveness of our database-searching
scheme. Our algorithms are very efficient and run in realtime on a desktop computer. We describe how this technology could
be employed to construct a “smart VCR” that was capable of alerting the viewer to the beginning of a specific program or identifying 相似文献
19.
In this paper we describe the fundamental principles that guide our work process at 5050 Ltd, in developing concepts and
prototypes for personal technology devices. We maintain that in designing personal devices it is critical to address the social
interaction elements of the user experience. We introduce the term “social functionality” to refer to those aspects of a device
that are specifically designed to elicit sociability and serendipity. It also refers to those aspects which enable users to
communicate or represent individuating characteristics through the use of their device. Social functionality is seen as a
critical success factor in the design of future personal devices. Introducing social functionality in personal technology
devices requires a multidisciplinary approach. Design and technology are seen as inseparable elements of the development process.
The mbracelet1, a wearable prototype we developed for, and in association with, NCR’s The Knowledge Lab, is used as a case in point. 相似文献
20.
S. Bernardi S. Donatelli A. Horváth 《International Journal on Software Tools for Technology Transfer (STTT)》2001,3(4):417-430
An implementation of compositionality for stochastic well-formed nets (SWN) and, consequently, for generalized stochastic
Petri nets (GSPN) has been recently included in the GreatSPN tool. Given two SWNs and a labelling function for places and
transitions, it is possible to produce a third one as a superposition of places and transitions of equal label. Colour domains
and arc functions of SWNs have to be treated appropriately. The main motivation for this extension was the need to evaluate
a library of fault-tolerant “mechanisms” that have been recently defined, and are now under implementation, in a European
project called TIRAN. The goal of the TIRAN project is to devise a portable software solution to the problem of fault tolerance
in embedded systems, while the goal of the evaluation is to provide evidence of the efficacy of the proposed solution. Modularity
being a natural “must” for the project, we have tried to reflect it in our modelling effort. In this paper, we discuss the
implementation of compositionality in the GreatSPN tool, and we show its use for the modelling of one of the TIRAN mechanisms,
the so-called local voter.
Published online: 24 August 2001 相似文献