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1.
Easy-to-use audio/video authoring tools play a crucial role in moving multimedia software from research curiosity to mainstream
applications. However, research in multimedia authoring systems has rarely been documented in the literature. This paper describes
the design and implementation of an interactive video authoring system called Zodiac, which employs an innovative edit history abstraction to support several unique editing features not found in existing commercial
and research video editing systems. Zodiac provides users a conceptually clean and semantically powerful branching history model of edit operations to organize the authoring process, and to navigate among versions of authored documents. In addition,
by analyzing the edit history, Zodiac is able to reliably detect a composed video stream's shot and scene boundaries, which facilitates interactive video browsing.
Zodiac also features a video object annotation capability that allows users to associate annotations to moving objects in a video sequence. The annotations themselves could
be text, image, audio, or video. Zodiac is built on top of MMFS, a file system specifically designed for interactive multimedia development environments, and implements an internal buffer
manager that supports transparent lossless compression/decompression. Shot/scene detection, video object annotation, and buffer
management all exploit the edit history information for performance optimization. 相似文献
2.
I. Mirbel B. Pernici T. Sellis S. Tserkezoglou M. Vazirgiannis 《The VLDB Journal The International Journal on Very Large Data Bases》2000,9(2):111-130
Abstract. When authoring multimedia scenarios, and in particular scenarios with user interaction, where the sequence and time of occurrence
of interactions is not predefined, it is difficult to guarantee the consistency of the resulting scenarios. As a consequence,
the execution of the scenario may result in unexpected behavior or inconsistent use of media. The present paper proposes a methodology
for checking the temporal integrity of interactive multimedia document (IMD) scenarios at authoring time at various levels.
The IMD flow is mainly defined by the events occurring during the IMD session. Integrity checking consists of a set of discrete
steps, during which we transform the scenario into temporal constraint networks representing the constraints linking the different
possible events in the scenario. Temporal constraint verification techniques are applied to verify the integrity of the scenario,
deriving a minimal network, showing possible temporal relationships between events given a set of constraints.
Received June 9, 1998 / Accepted November 10, 1999 相似文献
3.
Large-Scale Requirements Analysis Revisited: The need for Understanding the Political Ecology of Requirements Engineering 总被引:1,自引:1,他引:1
This paper addresses the political nature of requirements for large systems, and argues that requirements engineering theory and practice must become more engaged with these issues.
It argues that large-scale system requirements is constructed through a political decision process, whereby requirements emerge
as a set of mappings between consecutive solution spaces justified by a problem space of concern to a set of principals. These
solution spaces are complex socio-technical ensembles that often exhibit non-linear behaviour in expansion due to domain complexity
and political ambiguity. Stabilisation of solutions into agreed-on specifications occurs only through the exercise of organisational
power. Effective requirements engineering in such cases is most effectively seen as a form of heterogeneous engineering in which technical, social, economic and institutional factors are brought together in a current solution space that provides
the baseline for construction of proposed new solution spaces. 相似文献
4.
An airborne air-to-ground data link communication interface was evaluated in a multi-sector-planning scenario using an Airbus
A 340 full flight simulator. In a close-to-reality experimental setting, eight professional crews performed a flight mission
in a mixed voice/data link environment. Experimental factors were the medium (voice vs. data link), workload (low vs. high)
and the role in the cockpit (pilot flying vs. pilot non-flying). Data link communication and the usability of the newly developed
communication interface were rated positively by the pilots, but there is a clear preference for using a data link only in
the phase of cruise. Cognitive demands were determined for selected sections of en-route flight. Demands are affected mainly
by increased communication needs. In the pilots’ view, although a data link has no effect on safety or the possibilities of
intervention, it causes more problems. The subjective workload, as measured with the NASA Task Load Index, increased moderately
under data link conditions. A data link has no general effect on pilots’ situation awareness although flight plan negotiations
with a data link cause a distraction of attention from monitoring tasks. The use of a data link has an impact on air-to-ground
as well as intra-crew communication. Under data link conditions the pilot non-flying plays a more active role in the cockpit.
Before introducing data link communication, several aspects of crew resource management have to be reconsidered.
Correspondence and offprint requests to: T. Müller, Technical University of Berlin, Institute of Psychology and Ergonomics, Department of Human–Machine Systems, Jebensstrasse
1, 10623 Berlin, Germany. 相似文献
5.
We present a shared memory algorithm that allows a set of f+1 processes to wait-free “simulate” a larger system of n processes, that may also exhibit up to f stopping failures.
Applying this simulation algorithm to the k-set-agreement problem enables conversion of an arbitrary k-fault-tolerant{\it n}-process solution for the k-set-agreement problem into a wait-free k+1-process solution for the same problem. Since the k+1-processk-set-agreement problem has been shown to have no wait-free solution [5,18,26], this transformation implies that there is no
k-fault-tolerant solution to the n-process k-set-agreement problem, for any n.
More generally, the algorithm satisfies the requirements of a fault-tolerant distributed simulation.\/ The distributed simulation implements a notion of fault-tolerant reducibility\/ between decision problems. This paper defines these notions and gives examples of their application to fundamental distributed
computing problems.
The algorithm is presented and verified in terms of I/O automata. The presentation has a great deal of interesting modularity,
expressed by I/O automaton composition and both forward and backward simulation relations. Composition is used to include
a safe agreement\/ module as a subroutine. Forward and backward simulation relations are used to view the algorithm as implementing a multi-try snapshot\/ strategy.
The main algorithm works in snapshot shared memory systems; a simple modification of the algorithm that works in read/write
shared memory systems is also presented.
Received: February 2001 / Accepted: February 2001 相似文献
6.
We discuss the problem of capturing media streams which occur during a live lecture in class or during a telepresentation.
Instead of presenting yet another method or system for capturing the classroom experience, we introduce some informal guidelines
and show their importance for such a system. We derive from these guidelines a formal framework for sets of data streams and
an application model to handle these sets so that a real-time replay becomes possible. The Authoring on the Fly system is a possible realization of a framework which follows these guidelines. It allows the capture and real-time replay
of data streams captured during a (tele)presentation, including audio, video, and whiteboard action streams. This article
gives an overview of the different AoF system components for the various phases of the teaching and learning cycle. It comprises
an integrated text and graphics editor for the preparation of pages to be loaded by the whiteboard during the presentation
phase. The recording component of the system captures various data streams of the live presentation. They are postprocessed
by the system so that they become instances of the class of media for whose replay the general application model was developed.
From a global point of view, the Authoring on the Fly system allows one to merge three apparently distinct tasks – teaching
in class, telepresentation, and multimedia authoring – into one single activity. The system has been used routinely for recording
telepresentations over the MBone net and has already led to a large number of multimedia documents which have been integrated
automatically into Web-based teaching and learning environments. 相似文献
7.
8.
Human error is responsible for a large proportion of the anaesthesia mishaps that occur annually in the United States. Ventilation-related events (VRE) constitute a significant number of anaesthesia critical incidents. Monitoring equipment and their displays extend anaesthesiologists’
resources during VRE but at the expense of additional cognitive demands. This project is a cognitive analysis of intraoperative (inside the operating room) VRE. Goal–means networks were utilised to build a problem-solving model of clinicians’ management
of patients’ ventilation during anaesthesia and to map the demands of VRE. The model was also used to identify challenging
VRE that were then simulated using a comprehensive anaesthesia simulator. The response of eight experienced clinicians was
captured on videotape and analysed to investigate the effectiveness of medical equipment in supporting clinical decision making
during VRE. 相似文献
9.
The present study began with an assessment of the reliability and usefulness of an existing minor event coding system in
a British ‘high-consequence’ industry. It was discovered that despite the fact that the system produced replicable data, when
tested in a reliability trial the causal inferences it was producing failed to meet the normal criteria for statistical reliability.
It was therefore felt necessary to create a new model of the human factors component of action in this industry, from which
a model of human factors error in the same industry could be inferred. A set of codes (to facilitate statistical analysis) were deduced from this last,
which were then tested in a new reliability trial. The results from this trial were very encouraging, and after a six-month
pilot study in which it demonstrated its usefulness as a trend and patterning tool, the system is now being phased in within
this industry. 相似文献
10.
Towards video-based immersive environments 总被引:2,自引:0,他引:2
Arun Katkere Saied Moezzi Don Y. Kuramura Patrick Kelly Ramesh Jain 《Multimedia Systems》1997,5(2):69-85
Video provides a comprehensive visual record of environment activity over time. Thus, video data is an attractive source
of information for the creation of virtual worlds which require some real-world fidelity. This paper describes the use of
multiple streams of video data for the creation of immersive virtual environments. We outline our multiple perspective interactive video (MPI-Video) architecture which provides the infrastructure for the processing and analysis of multiple streams of video data. Our MPI-Video system performs automated analysis of the raw video and constructs a model of the environment and object activity within
this environment. This model provides a comprehensive representation of the world monitored by the cameras which, in turn,
can be used in the construction of a virtual world. In addition, using the information produced and maintained by the MPI-Video system, our immersive video system generates virtual video sequences. These are sequences of the dynamic environment from an arbitrary view point generated
using the real camera data. Such sequences allow a user to navigate through the environment and provide a sense of immersion
in the scene. We discuss results from our MPI-Video prototype, outline algorithms for the construction of virtual views and provide examples of a variety of such immersive video
sequences. 相似文献
11.
Bir Bhanu Yingqiang Lin Grinnell Jones Jing Peng 《Machine Vision and Applications》2000,11(6):289-299
Target recognition is a multilevel process requiring a sequence of algorithms at low, intermediate and high levels. Generally,
such systems are open loop with no feedback between levels and assuring their performance at the given probability of correct
identification (PCI) and probability of false alarm (Pf) is a key challenge in computer vision and pattern recognition research. In this paper, a robust closed-loop system for recognition
of SAR images based on reinforcement learning is presented. The parameters in model-based SAR target recognition are learned.
The method meets performance specifications by using PCI and Pf as feedback for the learning system. It has been experimentally validated by learning the parameters of the recognition system
for SAR imagery, successfully recognizing articulated targets, targets of different configuration and targets at different
depression angles. 相似文献
12.
Deepak Kapur Mahadevan Subramaniam 《International Journal on Software Tools for Technology Transfer (STTT)》2000,3(1):32-65
We show that existing theorem proving technology can be used effectively for mechanically verifying a family of arithmetic
circuits. A theorem prover implementing: (i) a decision procedure for quantifier-free Presburger arithmetic with uninterpreted
function symbols; (ii) conditional rewriting; and (iii) heuristics for carefully selecting induction schemes from terminating
recursive function definitions; and (iv) well integrated with backtracking, can automatically verify number-theoretic properties
of parameterized and generic adders, multipliers and division circuits. This is illustrated using our theorem prover Rewrite Rule Laboratory (RRL). To our knowledge, this is the first such demonstration of the capabilities of a theorem prover mechanizing induction.
The above features of RRL are briefly discussed using illustrations from the verification of adder, multiplier and division
circuits. Extensions to the prover likely to make it even more effective for hardware verification are discussed. Furthermore,
it is believed that these results are scalable, and the proposed approach is likely to be effective for other arithmetic circuits
as well. 相似文献
13.
R. Braumandl J. Claussen A. Kemper D. Kossmann 《The VLDB Journal The International Journal on Very Large Data Bases》2000,8(3-4):156-177
Inter-object references are one of the key concepts of object-relational and object-oriented database systems. In this work,
we investigate alternative techniques to implement inter-object references and make the best use of them in query processing,
i.e., in evaluating functional joins. We will give a comprehensive overview and performance evaluation of all known techniques
for simple (single-valued) as well as multi-valued functional joins. Furthermore, we will describe special order-preserving\/ functional-join techniques that are particularly attractive for decision support queries that require ordered results. While
most of the presentation of this paper is focused on object-relational and object-oriented database systems, some of the results
can also be applied to plain relational databases because index nested-loop joins\/ along key/foreign-key relationships, as they are frequently found in relational databases, are just one particular way to
execute a functional join.
Received February 28, 1999 / Accepted September 27, 1999 相似文献
14.
This article covers the conception and development of Empedia, a new locative software environment for mobile phones specifically designed for expanded archives, documentary and heritage/historical interpretation, using situated and collaborative learning, at resonant and related sites. It will examine our developmental methods employed through a number of workshops for pilot projects, employed specifically to test the reception of rich media assets and augmented reality features in a simple open source user interface and authoring environment for iPhone and browser consumption. The research projects at the Institute of Creative Technologies (IOCT) examined here include: a D. H. Lawrence Heritage Blue Line trail in Eastwood, Nottinghamshire (2009); Riverains, a dramatised history trail in Shoreditch, London (2010); and the use of collaborative documentary in Codes of Disobedience and Dysfunctionality in Athens (2011). 相似文献
15.
Luiz Fernando G. Soares Rogério F. Rodrigues Débora C. Muchaluat Saade 《Multimedia Systems》2000,8(2):118-134
This paper discusses multimedia and hypermedia modeling, authoring and formatting tools, presenting the proposals of the
HyperProp system and comparing them to related work. It also highlights several research challenges that still need to be
addressed. Moreover, it stresses the importance of document logical structuring and considers the use of compositions in order
to represent context relations, synchronization relations, derivation relations and task relations in hypermedia systems.
It discusses temporal and spatial synchronization among multimedia objects and briefly presents the HyperProp graphical authoring
and formatting tools. Integration between the proposed system and the WWW is also addressed. 相似文献
16.
Detection, segmentation, and classification of specific objects are the key building blocks of a computer vision system for
image analysis. This paper presents a unified model-based approach to these three tasks. It is based on using unsupervised
learning to find a set of templates specific to the objects being outlined by the user. The templates are formed by averaging
the shapes that belong to a particular cluster, and are used to guide a probabilistic search through the space of possible
objects. The main difference from previously reported methods is the use of on-line learning, ideal for highly repetitive
tasks. This results in faster and more accurate object detection, as system performance improves with continued use. Further,
the information gained through clustering and user feedback is used to classify the objects for problems in which shape is
relevant to the classification. The effectiveness of the resulting system is demonstrated in two applications: a medical diagnosis
task using cytological images, and a vehicle recognition task.
Received: 5 November 2000 / Accepted: 29 June 2001
Correspondence to: K.-M. Lee 相似文献
17.
A.F.R. Rahman M.C. Fairhurst 《International Journal on Document Analysis and Recognition》2000,3(1):40-55
Abstract. A new parallel hybrid decision fusion methodology is proposed. It is demonstrated that existing parallel multiple expert
decision combination approaches can be divided into two broad categories based on the implicit decision emphasis implemented.
The first category consists of methods implementing computationally intensive decision frameworks incorporating a priori information
about the target task domain and the reliability of the participating experts, while the second category encompasses approaches
implementing group consensus without assigning any importance to the reliability of the experts and ignoring other contextual
information. The methodology proposed in this paper is a hybridisation of these two approaches and has shown significant performance
enhancements in terms of higher overall recognition rates along with lower substitution rates. Detailed analysis using two
different databases supports this claim.
Received January 19, 1999 / Revised March 20, 2000 相似文献
18.
Kian-Lee Tan Cheng Hian Goh Beng Chin Ooi 《The VLDB Journal The International Journal on Very Large Data Bases》2000,9(3):261-278
In many decision-making scenarios, decision makers require rapid feedback to their queries, which typically involve aggregates.
The traditional blocking execution model can no longer meet the demands of these users. One promising approach in the literature, called online aggregation, evaluates an aggregation query progressively as follows: as soon as certain data have been evaluated, approximate answers
are produced with their respective running confidence intervals; as more data are examined, the answers and their corresponding
running confidence intervals are refined. In this paper, we extend this approach to handle nested queries with aggregates
(i.e., at least one inner query block is an aggregate query) by providing users with (approximate) answers progressively as
the inner aggregation query blocks are evaluated. We address the new issues pose by nested queries. In particular, the answer
space begins with a superset of the final answers and is refined as the aggregates from the inner query blocks are refined.
For the intermediary answers to be meaningful, they have to be interpreted with the aggregates from the inner queries. We
also propose a multi-threaded model in evaluating such queries: each query block is assigned to a thread, and the threads can be evaluated concurrently and independently.
The time slice across the threads is nondeterministic in the sense that the user controls the relative rate at which these subqueries are being evaluated. For enumerative nested queries, we propose a priority-based evaluation strategy to present answers that are certainly in the final answer
space first, before presenting those whose validity may be affected as the inner query aggregates are refined. We implemented
a prototype system using Java and evaluated our system. Results for nested queries with a level and multiple levels of nesting
are reported. Our results show the effectiveness of the proposed mechanisms in providing progressive feedback that reduces
the initial waiting time of users significantly without sacrificing the quality of the answers.
Received April 25, 2000 / Accepted June 27, 2000 相似文献
19.
Constructing stories is a type of playing that involves mobilizing the storyteller’s imagination and finding original ways
to convey narrative intentions. When a child invents a story, there is a natural interaction with the local environment and
the use of various means of expression. We adopted a user-centered approach to design POGO, a playful environment which utilizes
the child’s physical environment and sensory modalities. Pogo is a system of active tools that enable children to create stories
by connecting physical and virtual environments. By providing children with the possibility of capturing and manipulating
images and various media, and combining them in sequential form, Pogo triggered new strategies in the construction of narrative
logic, time and space, in the construction of the episodes and in the visual narration.
Correspondence to: Fran?oise Decortis, Psychology and Education Sciences Department, University of Liege, 4000 Liege, Belgium. Email:francoise.decortis@ulg.ac.be 相似文献
20.
Summary. Different replication algorithms provide different solutions to the same basic problem. However, there is no precise specification
of the problem itself, only of particular classes of solutions, such as active replication and primary-backup. Having a precise
specification of the problem would help us better understand the space of possible solutions and possibly come out with new
ones. We present a formal definition of the problem solved by replication in the form of a correctness criterion called x-ability (exactly-once ability). An x-able service has obligations to its environment and its clients. It must update its environment
under exactly-once semantics. Furthermore, it must provide idempotent, non-blocking request processing and deliver consistent
results to its clients. We illustrate the value of x-ability through a novel replication protocol that handles non-determinism
and external side-effects. The replication protocol is asynchronous in the sense that it may vary, at run-time and according
to the asynchrony of the system, between some form of primary-backup and some form of active replication.
Received: December 2000 / Accepted: September 2001 相似文献