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1.
Parallel parsing is currently receiving attention but there is little discussion about the adaptation of sequential error handling techniques to these parallel algorithms. We describe a noncorrecting error handler implemented with a parallel LR substring parser. The parser used is a parallel version of Cormack's LR substring parser. The applicability of noncorrecting error handling for parallel parsing is discussed. The error information provided for a standard set of 118 erroneous Pascal programs is analysed. The programs are run on the sequential LR substring parser.  相似文献   

2.
We describe our implementation of C and Fortran preprocessors for the FPS T-series hypercube. The target of these preprocessors is the occam I language. We provide a brief overview of the INMOS transputer and the Weitek vector processing unit (VPU). These two units comprise one node of the T-series. Some depth of understanding of the VPU is required to fully appreciate the problems encountered in generating vector code. These complexities were not fully appreciated at the outset. The occam I language is briefly described. We focus on only those aspects of occam I which differ radically from C. The transformations used to preprocess C into occam I are discussed in detail. The special problems with the VPU both in terms of its (non)interface with occam I and in dealing with numerical programs is discussed separately. A lengthy discussion on the special techniques required for compilation is provided. C and Fortran are simply incompatible with the occam I model. We provide a catalogue of problems encountered. We emphasize that these problems are not so much with occam I but with preprocessing to occam I. We feel the CSP and occam I models are quite good for distributed processing. The ultimate message from this work should be seen in a larger context. Several languages—such as Ada and Modula-2—are being touted as the standards for the 1990s. These languages severely restrict parallel programming style; this may make saving dusty decks by preprocessing an impossibility.  相似文献   

3.
We present a method for the recognition of complex actions. Our method combines automatic learning of simple actions and manual definition of complex actions in a single grammar. Contrary to the general trend in complex action recognition that consists in dividing recognition into two stages, our method performs recognition of simple and complex actions in a unified way. This is performed by encoding simple action HMMs within the stochastic grammar that models complex actions. This unified approach enables a more effective influence of the higher activity layers into the recognition of simple actions which leads to a substantial improvement in the classification of complex actions. We consider the recognition of complex actions based on person transits between areas in the scene. As input, our method receives crossings of tracks along a set of zones which are derived using unsupervised learning of the movement patterns of the objects in the scene. We evaluate our method on a large dataset showing normal, suspicious and threat behaviour on a parking lot. Experiments show an improvement of ~ 30% in the recognition of both high-level scenarios and their composing simple actions with respect to a two-stage approach. Experiments with synthetic noise simulating the most common tracking failures show that our method only experiences a limited decrease in performance when moderate amounts of noise are added.  相似文献   

4.
5.
Event ma nagement and response generation are two essential aspects of systems for ambient intelligence. This work proposes handling these issues through the use of a semantic model for ambient intelligence which, under the umbrella of a philosophical and common-sense optic, describes what actions and events are, how they are connected, and how computational systems should think about their meaning. This model entails an approach with which to both reason about and model context events and generate behavioral responses to those events, when necessary. The model supports this ad hoc response generation by automatically composing services when those which are available do not meet the expected functionality (without requesting user intervention). An evaluation methodology is presented and illustrated with a case scenario, in which synthetic data has been generated to emulate events and analyze the system response. The evaluation of the system response is carried out on the basis of a vector of attributes.  相似文献   

6.
This paper surveys some of the contemporary work in syntactic/semantic pattern recognition, with emphasis on four topics that are active research areas. These areas-grammatical inferrence, probabilistic models, syntactic errorcorrection, and grammars with attributes-present challenging questions both as to theory and as to practice.Portions of the paper are adapted from Syntactic Methods in Pattern Recognition, M. G. Thomason, to appear in theProceedings of the NATO Advanced Study Institute, Oxford University, 1981 J. Kittler, Ed. (D. Reidel Publishing Company. Dordrecht, Holland).  相似文献   

7.
The identification of part families and machine groups that form the cells is a major step in the development of a cellular manufacturing system and, consequently, a large number of concepts, theories and algorithms have been proposed. One common assumption for most of these cell formation algorithms is that the product mix remains stable over a period of time. In today’s world, the market demand is being shaped by consumers resulting in a highly volatile market. This has given rise to a new class of products characterized by low volume and high variety. To incorporate product mix changes into an existing cellular manufacturing system many important issues have to be tackled. In this paper, a methodology to incorporate new parts and machines into an existing cellular manufacturing system has been presented. The objective is to fit the new parts and machines into an existing cellular manufacturing system thereby increasing machine utilization and reducing investment in new equipment.  相似文献   

8.
Automatic recommenders are now omnipresent in e-commerce websites, as selecting and offering to users products they may be interested in can considerably increase sales revenue. The most popular recommendation strategy is currently considered to be the collaborative filtering technique, based on offering to the user who will receive the recommendation items that were appealing to other individuals with similar preferences (the so-called neighbors). On the other hand, its principal obstacle is the sparsity problem, related to the difficulty to find overlappings in ratings when there are many items. As the product catalogue of these sites gets more and more diverse, a new problem has arisen that happens when users share likings for lots of products (for which they are reckoned to be neighbors) but they differ in products similar to the one that is being considered for recommendation. They are fake neighbors. Narrowing the range of products on which similarities between users are sought can help to avoid this, but it usually causes a worsening of the sparsity problem because the chances of finding overlappings gets lower. In this paper, a new strategy is proposed based on semantic reasoning that aims to improve the neighborhood formation in order to overcome the aforementioned fake neighborhood problem. Our approach is aimed at making more flexible the search for semantic similarities between different products, and thus not require users to rate the same products in order to be compared.  相似文献   

9.
在高速分组分类中,基于TCAM的硬件实现方法是一种重要的解决方案.但TCAM存储空间价格昂贵,并且要求区间匹配转换成前缀匹配,大区间报文匹配的直接转化通常会引起规则空间的膨胀.本文提出一种规则的优化表示方案,提高了区间规则表示的效率,使区间匹配转化的最坏情况由2w-2减少到w,有效节省了空间.  相似文献   

10.
Grid computing environments are set up mainly to encourage the shared use of different resources based on business/scientific needs. The way these resources are shared in terms of CPU cycles, storage capacity, software licenses etc., is normally dictated by the availability of these resources outside the local administration context. The Semantic Grid is the extension of Grid computing with Semantic Web-based technologies. The Semantic Grid represents grid management data in a machine-understandable format, and reasoning can handle complicated situations in virtual organization management. This paper presents the extension of the collaborative awareness model (CAM) to manage virtual organizations in Semantic Grid environments. CAM applies some theoretical principles of awareness models to promote resource interaction and management, as well as task delivery.  相似文献   

11.
12.
The issues of data integration and interoperability pose significant challenges in scientific hydrological and environmental studies, due largely to the inherent semantic and structural heterogeneities of massive datasets and non-uniform autonomous data sources. To address these data integration challenges, we propose a unified data integration framework, called Hydrological Integrated Data Environment (HIDE). HIDE is based on a labeled-tree data integration model referred to as DataNode tree. Using this framework, characteristics of datasets gathered from diverse data sources - with different logical and access organizations - can be extracted and classified as Time-Space-Attribute (TSA) labels and are subsequently arranged in a DataNode tree. The uniqueness of our approach is that it effectively combines the semantic aspects of the scientific domain with diverse datasets having different logical organizations to form a unified view. Further, we also adopt a metadata-based approach for specifying the TSA-DataNode tree in order to achieve flexibility and extensibility. The search engine of our HIDE prototype system evaluates a simple user query systematically on the TSA-DataNode tree, presenting integrated results in a standardized format that facilitates both effective and efficient data integration.  相似文献   

13.
基于不带字库的图形LCD模块汉字显示解决方案   总被引:6,自引:5,他引:6  
针对不带汉字字库的图形点阵液晶模块的系统,嵌入GB2312-80字库芯片,利用国标区位码和液晶模块的特点实现汉字和西文字符的混合显示。本文介绍了汉字机内码与区位码的相互转换关系,以及利用T6963C作控制器的液晶模块YJ240D的基本原理,探讨了实际应用中此类液晶模块在嵌入式仪器仪表中混合显示的硬件设计和软件实现方法。  相似文献   

14.
Recommender systems arose with the goal of helping users search in overloaded information domains (like e-commerce, e-learning or Digital TV). These tools automatically select items (commercial products, educational courses, TV programs, etc.) that may be appealing to each user taking into account his/her personal preferences. The personalization strategies used to compare these preferences with the available items suffer from well-known deficiencies that reduce the quality of the recommendations. Most of the limitations arise from using syntactic matching techniques because they miss a lot of useful knowledge during the recommendation process. In this paper, we propose a personalization strategy that overcomes these drawbacks by applying inference techniques borrowed from the Semantic Web. Our approach reasons about the semantics of items and user preferences to discover complex associations between them. These semantic associations provide additional knowledge about the user preferences, and permit the recommender system to compare them with the available items in a more effective way. The proposed strategy is flexible enough to be applied in many recommender systems, regardless of their application domain. Here, we illustrate its use in AVATAR, a tool that selects appealing audiovisual programs from among the myriad available in Digital TV.  相似文献   

15.
Cooperative multirobot systems require both real-time responsiveness and some form of coordination to get the desired overall behavior. This can be obtained with a combined use of reactive and deliberative subsystems. In this paper, we illustrate an effective technique for putting together these two components. The method is based on the idea that every robot maintains a local map and then dynamically focuses its attention on the part which is relevant in the current context. The framework, which is fully distributed and scalable, is enriched with cooperative behaviors, i.e. behaviors pursued by more than one robot. We provide the details of how the proposed idea has been studied in a simulated cooperative foraging task and proved to be effective.  相似文献   

16.
Mobile Ad hoc Network due to its intrinsic properties of mobility, infrastructure-less working and vulnerability of underlined standard routing protocols is exposed to various packet drop attacks such as blackhole attack, grayhole attack and co-operative blackhole attack. These attacking nodes participate actively in the route establishment process and when a path is established between two end nodes through these nodes, these nodes drop the data packets according to a pattern related to the type of attack. So, security of the network communication is a very critical issue and must be handled with greater efficiency and effectiveness. A lot of research has been carried out to detect and mitigate the effects of blackhole attack and its variants in MANET. In this paper, Different variants of blackhole attack are discussed along with shortcomings of present literature. We present a comprehensive taxonomy of the mitigation and detection mechanism along with summarization and comparison of some published work related to those categories. There are in total sixteen different categories of mitigation mechanism and we have reviewed and summarized ninety one research works related to the presented categories on various parameters like overhead, base protocol, modification in base routing protocol, detection type, nature, features and limitations.  相似文献   

17.
Directing at the problem of inaccurate expression of tacit knowledge and low heuristic of retrieval results in the design inspiration drawing process of designers based on traditional motifs, a semantic data representation method of traditional motifs knowledge is put forward, and an effective knowledge base construction and knowledge retrieval method for traditional motifs are described. First, the connotation of traditional motifs is deeply explored based on the theory of symbol semantics, realizing the interpretation and transfer of the semantic features in traditional motifs. Second, shape grammar is adopted for fractal traditional motifs, the hierarchical structure of traditional motifs is built, and the parametric coding of semantic features of traditional motifs is completed, providing the semantic data representation method of traditional motifs knowledge. Third, based on the clustering algorithm, the construction method of the traditional motifs knowledge base is explained, and a traditional motifs knowledge retrieval method taking into account the user's perceptual preference is proposed. Finally, setting the traditional Chinese motifs as an example, with a tea set as the designed product, the construction process of a small traditional motif knowledge base is shown in detail, proving the feasibility of this paper’s theory. Compared with the traditional theory, the semantic data representation method of traditional pattern knowledge is greatly advantageous in semantic differences elimination and computational efficiency.  相似文献   

18.
《国际计算机数学杂志》2012,89(16):3361-3379
The main idea of this work is to present a tool which may be useful to generate a mesh of points where urban actions may be taken after analysing and understanding complex urban situations. By the word complex we mean urban concentrations without precise limits and without a recognizable geometry pattern. In these situations, it is very hard for the architects to understand the system. Therefore, it is very difficult to define an action plan for this type of urban situations. What we propose is an adaptation of a neural network algorithm to work in the context of urban networks. Our objective is to develop a strategy to change this weakness of sparse urban development by activating public spaces with new meanings. A new 2D triangle mesh simplification model is introduced with the central property of preserving the shape of the original mesh. The mathematical model presented consists of a self-organizing algorithm whose objective is to generate the positions of the nodes of the simplified mesh; afterwards, a triangulation algorithm is carried out to reconstruct the triangles of the new simplified mesh. With this algorithm, it is possible to perform specific actions in an urban space, because the urban territory can be considered as a complex mesh with nodes and edges. A real example of an urban action is shown with the introduction of a wireless network in a residential area.  相似文献   

19.
利用表面等离子共振传感器进行免疫检测的实验中,需要在化学性质稳定的金膜表面固定蛋白质分子探针。如何验证一种方法是否能够成功固定蛋白质分子具有非常重要的现实意义。提出的验证方法采用酶反应作为标志,如果某种方法确实能有效固定蛋白质分子,那么它也能固定酶。将固定好酶的金膜浸入相应的底物溶液中发生变色反应,测量底物溶液的吸收光谱,即可根据结果判断是否有效固定了酶,同时达到判断这种方法是否可固定蛋白质的目的。具有快速、方便、低成本等优点。采用经过验证的方法固定抗IgG后通入IgG,实验响应良好。  相似文献   

20.
血液中血红蛋白和糖化血红蛋白(HbA1c)在偏酸性的溶液中具有不同的阳离子特性。根据这一特性采用离子交换液相色谱法梯度洗脱出血液中的不同物质成分,其中包括HbA1c。再利用紫外/可见光吸光光度计原理设计了能够检测到HbA1c浓度的检测器。由于洗脱的过程中不可避免的会出现两种物质洗脱不完全的情况,在检测得到的色谱曲线上会出现重叠峰。为了能够准确的计算HbA1c所对应的峰面积,采用指数修正高斯分布模型(EMG)来拟合测得的吸光度曲线以达到重叠峰分离的效果,最后计算分离出的HbA1c成分所对应的峰面积和整个吸光度曲线的面积。两面积的比值即是糖化血红蛋白的浓度。  相似文献   

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