首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
Predicting the onset of epileptic seizure is an important and difficult biomedical problem, which has attracted substantial attention of the intelligent computing community over the past two decades. We apply recurrent neural networks (RNN) combined with signal wavelet decomposition to the problem. We input raw EEG and its wavelet-decomposed subbands into RNN training/testing, as opposed to specific signal features extracted from EEG. To the best of our knowledge this approach has never been attempted before. The data used included both scalp and intracranial EEG recordings obtained from two epileptic patients. We demonstrate that the existence of a “preictal” stage (immediately preceding seizure) of some minutes duration is quite feasible.  相似文献   

2.
A term rewrite system is terminating when no infinite reduction sequences are possible. Relative termination generalizes termination by permitting infinite reductions as long as some distinguished rules are not applied infinitely many times. Relative termination is thus a fundamental notion that has been used in a number of different contexts, like analyzing the confluence of rewrite systems or the termination of narrowing. In this work, we introduce a novel technique to prove relative termination by reducing it to dependency pair problems. To the best of our knowledge, this is the first significant contribution to Problem #106 of the RTA List of Open Problems. We first present a general approach that is then instantiated to provide a concrete technique for proving relative termination. The practical significance of our method is illustrated by means of an experimental evaluation.  相似文献   

3.
The mini-max method is designed for the analysis and optimization of energy consumption in single-processor real-time systems and offers several advantages over alternative methods when used in single-task and multitask systems. There has been no research, however, dedicated to its use in real-time systems with several processing elements. This work deals with the use of the mini-max method in subsystems with two executive elements. Two methods for the organization of systems processing sequential task threads are proposed. The first method is a synchronous one with an allotted time period for each task, and the second method involves an asynchronous task stream. The analysis and comparison of these methods are performed, and their efficiency in solving the problem of energy consumption is shown.  相似文献   

4.
Professional sport is a vital part of many peoples’ lives and sport is a multi billion industry in its own right. Professional coaches, sporting professionals and sports journalists often use video recordings of sporting events as a tool in their daily work. With the rapid growth of sport video recordings, there is an emerging demand for a sophisticated sports content-based video indexing systems. Video recordings of sporting event broadcasts often last several hours including commercial breaks. It is therefore time-consuming and difficult to locate key segments containing highlights. This study proposes the use of computational intelligence strategies and information from both the audio and video domains to automatically locate sporting highlight on personal video playback devices. Tennis is chosen as the target domain but the strategy should generalize to other sports as well. Experimental results show that both the mean precision and recall rates are higher than 89%, hence, the proposed approach is capable of effectively detecting tennis highlights in sports broadcasts.  相似文献   

5.
A group of algorithms has been developed to investigate the characteristics of beat-to-beat intervals preceding and following the onset and termination of repeated pattern ventricular arrhythmias (RPVA) such as bigeminy and trigeminy. Eighty-five patients, each with more than 3000 ventricular ectopic beats in a 24-hour Holter recording and with more than 10 episodes of RPVA, were evaluated. A statistically significant prolongation of sinus intervals preceding the onset of bigeminy and trigeminy and shortening of postectopic intervals after the onset were observed. In addition, shortening of postectopic intervals before the termination of bigeminy and trigeminy and lengthening of sinus intervals following their termination were also seen. A significant presence of these characteristics was not observed in arrhythmias with a greater number of sinus beats between ectopic beats. These dynamics provide information which may be utilized in the assessment of mechanisms involved in the onset and termination of RPVA.  相似文献   

6.
Numerical computations form an essential part of almost any real-world program. Traditional approaches to termination of logic programs are restricted to domains isomorphic to (ℕ,>); more recent works study termination of integer computations where the lack of well-foundedness of the integers has to be taken into account. Termination of computations involving floating-point numbers can be counterintuitive because of rounding errors and implementation conventions. We present a novel technique that allows us to prove termination of such computations. Our approach extends the previous work on termination of integer computations. Alexander Serebrenik: This research has been carried out during the first author's stay at the Department of Computer Science, K.U. Leuven, Belgium and STIX, école Polytechnique, France.  相似文献   

7.
8.
文章分析了我国电子政务应用的特点,提出了一种面向电子政务的基于活动网络图的工作流模型,描述了组成工作流的基本实体类型,讨论了模型如何支持电子政务应用中的复杂流程、如何利用已有组织模型、如何与现有系统集成,同时还讨论了工作流模型与XPDL的映射关系,最后介绍了基于该模型的工作流引擎的实现方法.该工作流引擎已经在税务等多个政府信息系统中得到成功应用,应用结果表明所讨论的工作流模型能够满足我国现有电子政务的应用需求.  相似文献   

9.
In the last two decades, there has been an increased interest in automated deception detection systems (ADDs) for use in screening, although little attention has been paid to the usefulness of these systems. ADDs use various means, both invasive and non‐invasive, to ascertain individual intent to deceive or engage in malicious behaviour. Many papers introducing ADDs use signal detection theory to compare a technique's ability to detect malicious intent with other techniques, but in doing so, they do not include contextual information such as base rate and cost. In this paper, we aim to improve future research by showing how the inclusion of contextual information provides a more realistic picture of the research. Through both theoretical arguments and a real‐data example, we show that especially for those contexts where malicious intent is infrequent (ie, with low base rates of deception) that not factoring in the base rate overestimates the accuracy and therefore usefulness. We conclude with recommendations for how future research should provide a fuller picture of the accuracy and usefulness of ADDs.  相似文献   

10.
Context-sensitive rewriting (CSR) is a restriction of rewriting that forbids reductions on selected arguments of functions. With CSR, we can achieve a terminating behavior with non-terminating term rewriting systems, by pruning (all) infinite rewrite sequences. Proving termination of CSR has been recently recognized as an interesting problem with several applications in the fields of term rewriting and programming languages. Several methods have been developed for proving termination of CSR. Specifically, a number of transformations that permit treating this problem as a standard termination problem have been described. The main goal of this paper is to contribute to a better comprehension and practical use of transformations for proving termination of CSR. We provide new completeness results regarding the use of the transformations in two restricted (but relevant) settings: (a) proofs of termination of canonical CSR and (b) proofs of termination of CSR by using transformations together with simplification orderings. We have also made an experimental evaluation of the transformations, which complements the theoretical analysis from a practical point of view. This leads to new hierarchies of the transformations which are useful to guide their practical use when implementing tools for proving termination of CSR.  相似文献   

11.
In the past, similarity search for audio data has largely been focused on music. Recent digitization efforts in some of the larger animal sound archives bring other types of audio recordings into the focus of interest. Although recordings in animal sound archives are usually very well annotated by metadata, it is almost impossible to manually annotate all sounds made by animals in each recording. Complementary to classical text-based querying of databases that exploit available annotations, algorithms capable of automatically finding sections of recordings similar to a given query fragment provide a promising approach for content-based navigation. In our work, we present algorithms for feature extraction, as well as indexing and retrieval of animal sound recordings. Making use of a concept from image processing, the structure tensor, our feature extraction algorithm is adapted to the typical curve-like spectral features that are characteristic for many types of animal sounds. We propose a method for similarity search in animal sound databases which is obtained by adding a novel ranking scheme to an existing inverted file based approach for multimedia retrieval. Evaluation of our methods is based on recordings from the Animal Sound Archive, Berlin.  相似文献   

12.
ECA主动规则中的“条件”通常描述主动数据库的当前状态或状态转换,表现为一个或一组查询语句。但是经常还会遇到基于数据库一系列状态演变过程之上的查询要求,这时不能使用平常意义上的条件来表示。文章基于过去时序逻辑,提出了一种说明时序条件的语言,可以对数据库基于时间状态的演变的过程进行监控,从而增强了主动数据库中规则语言的表达能力。  相似文献   

13.
The amount of scientific papers in the Molecular Biology field has experienced an enormous growth in the last years, prompting the need of developing automatic Information Extraction (IE) systems. This work is a first step towards the ontology-based domain-independent generalization of a system that identifies Escherichia coli regulatory networks. First, a domain ontology based on the RegulonDB database was designed and populated. After that, the steps of the existing IE system were generalized to use the knowledge contained in the ontology, so that it could be potentially applied to other domains. The resulting system has been tested both with abstract and full articles that describe regulatory interactions for E. coli, obtaining satisfactory results.  相似文献   

14.
Accessing and updating information in a self organizing data structure in a distributed environment requires execution of various distributed algorithms. Design of such algorithms is often facilitated by the use of a distributed termination detection algorithm superimposed on top of another distributed algorithm. The problem of distributed termination detection is considered, and message counting is introduced as an effective technique in designing such algorithms. A class of efficient algorithms, based on the idea of message counting, for this problem is presented. After termination has occurred, it is detected within a small number of message communications. These algorithms do not require the FIFO (first in, first out) property for the communication lines. Assumptions regarding the connectivity of the processes are simple. The algorithms are incrementally developed, i.e. a succession of algorithms leading to the final algorithms is presented  相似文献   

15.
支持复合事件的主动规则的可终止性分析   总被引:7,自引:1,他引:7  
ECA规则系统已经成为主动数据库提供主动服务的通用机制.规则集合的可终止性是规则行为分析的一个重要问题.文中给出了ECA规则系统的形式化描述,并着重讨论了复合事件机制对可终止性问题的影响.文中结合规则实例给出了分析规则终止性的静态判定算法,这一算法可作为主动规则分析工具的理论基础.  相似文献   

16.
A clinical expert system has been developed for detection of Parkinson’s Disease (PD). The system extracts features from voice recordings and considers an advanced statistical approach for pattern recognition. The significance of the work lies on the development and use of a novel subject-based Bayesian approach to account for the dependent nature of the data in a replicated measure-based design. The ideas under this approach are conceptually simple and easy-to-implement by using Gibbs sampling. Available information could be included in the model through the prior distribution. In order to assess the performance of the proposed system, a voice recording replication-based experiment has been specifically conducted to discriminate healthy people from people suffering PD. The experiment involved 80 subjects, half of them affected by PD. The proposed system is able to discriminate acceptably well healthy people from people with PD in spite that the experiment has a reduced number of subjects.  相似文献   

17.
This paper is concerned with the simultaneous evolution of artificial neural network (ANN) architectures and weights. The current practice in evolving ANN's is to choose the best ANN in the last generation as the final result. This paper proposes a different approach to form the final result by combining all the individuals in the last generation in order to make best use of all the information contained in the whole population. This approach regards a population of ANN's as an ensemble and uses a combination method to integrate them. Although there has been some work on integrating ANN modules, little has been done in evolutionary learning to make best use of its population information. Four linear combination methods have been investigated in this paper to illustrate our ideas. Three real-world data sets have been used in our experimental studies, which show that the recursive least-square (RLS) algorithm always produces an integrated system that outperforms the best individual. The results confirm that a population contains more information than a single individual. Evolutionary learning should exploit such information to improve generalization of learned systems.  相似文献   

18.
19.
The need for robust solutions for sets of nonlinear multivariate constraints or equations needs no motivation. Subdivision-based multivariate constraint solvers typically employ the convex hull and subdivision/domain clipping properties of the Bézier/B-spline representation to detect all regions that may contain a feasible solution. Once such a region has been identified, a numerical improvement method is usually applied, which quickly converges to the root. Termination criteria for this subdivision/domain clipping approach are necessary so that, for example, no two roots reside in the same sub-domain (root isolation).This work presents two such termination criteria. The first theoretical criterion identifies subdomains with at most a single solution. This criterion is based on the analysis of the normal cones of the multiviarates and has been known for some time. Yet, a computationally tractable algorithm to examine this criterion has never been proposed. In this paper, we present a dual representation of the normal cones as parallel hyperplanes over the unit hypersphere, which enables us to construct an algorithm for identifying subdomains with at most a single solution. Further, we also offer a second termination criterion, based on the representation of bounding parallel hyperplane pairs, to identify and reject subdomains that contain no solution.We implemented both algorithms in the multivariate solver of the IRIT solid modelling system and present examples using our implementation.  相似文献   

20.
The concept of ??virtual organization?? was coined about 15?years ago to describe changes in organizational structures and value creation, enabled by the affordances of ICT. Not surprisingly, the Information Systems community has been influential in researching virtual organization phenomena. However, it appears that, since the notion of ??virtual?? in its most basic connotation only denotes some form of difference to a ??traditional?? form of organization, the term VO has been interpreted in varied form with an unsatisfying mix of VO notions existing in the literature. What is more, papers frequently exhibit mismatches between what they characterize as VO and the real-life phenomena they discuss. Motivated by these observations we carry out a literature analysis to explore differing notions of virtual organization. Based on a systematic classification of VO definitions, we uncover three distinct types of VO that are used in the literature, each of which interprets the notion of ??virtual?? differently, but is useful in its own right and exhibits unique management challenges. The first type, named Internal VO, revolves around internal virtualization based on distributed collaboration in virtual teams. It emerged on the back of emerging new groupware and communication technologies. Its main challenges stem from distributed project and work organization. The second type, named Network VO, describes a network of smaller companies that form a virtual entity, bringing in core competencies in short term collaborative projects. It emerged on the back of a emerging inter-organizational information systems and a trend of forming network arrangement. Its main challenges are with the governance of the multi-entity network. The third type, termed Outsourcing VO, refers to a hierarchical network of suppliers to which the focal firm outsources a significant part of its value creation, thus appearing as a virtual firm. It emerged on the back of the outsourcing trend of the last decades. Its main challenge is determining the optimal degree of integration and virtualization. With the identification and detailed exploration of the three VO types, our study contributes to a better understanding of the conceptual foundation of VO research and points to the necessity for conceptual clarity in future research.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号