16840924
Improving Transliteration with Precise Alignment of Phoneme Chunks and Using Contextual Features
Automatic transliteration of foreign names is basically regarded as a diminutive clone of the machine translation (MT) problem. It thus follows IBM's conventional MT models under the source-channel framework. Nonetheless, some parameters of this model dealing with zero-fertility words in the target sequences, can negatively impact transliteration effectiveness because of the inevitable inverted conditional probability estimation. Instead of source-channel, this paper presents a direct probabilistic transliteration model using contextual features of phonemes with a tailored alignment scheme for phoneme chunks. Experiments demonstrate superior performance over the source-channel for the task of English-Chinese transliteration.
35278447
An Investigation on Transformation-based Error-driven Learning Algorithm for Chinese Noun Phrase Extraction
Noun phrases are commonly used for generating index terms for information retrieval systems. Therefore, we need an effective noun phrase extraction method. In this paper, we propose an approach to extract maximal noun phrases from Chinese text. Although previous studies have been proposed to extract noun phrases, most of them are only applicable to Western languages. To the best of our knowledge, very few has handled Chinese text. Many existing approaches for Western languages made use of statistical methods. However, due to the complicated structure of maximal Chinese noun phrase, pure statistical approaches are not effective. We attempt to improve the performance of a statistical method by integrating it with the transformation-based error-driven learning (TEL) technique. Our methodology includes two modules. The first module applies a statistical method to extract Chinese noun phrases. The performance of this approach, in terms of precision and recall, is investigated. The second module applies the TEL algorithm to further refine the output of the first module. The TEL algorithm automatically learns a set of transformation rules to fix the errors that are obtained through comparing the output of the first module with the correctly annotated corpus. The learned rules can be applied to sentences in any corpus one by one to correct the errors. The TEL algorithm is shown to be effective in improving the precision.
1165688
A Chinese dictionary construction algorithm for information retrieval
In this article we propose a method for constructing, from raw Chinese text, a statistics-based automatic dictionary. The method makes use of local statistical information (i.e., data within a document) to identify and discard repeated string patterns, which, at an earlier stage, were substrings of legitimate words. Global statistical information (which exists throughout the entire corpus) and contextual constraints are then used for further filtering. The method can be used to alleviate the out-of-vocabulary (OOV) problem, which is commonly found in dictionary-based natural language information-processing applications, e.g., word segmentation. It can handle text corpora dynamically and, further, it does not impose any strict requirements on the size and quality of the training corpora. Based on our method, we constructed Chinese dictionaries from different Chinese corpora. We then applied the words in the constructed dictionaries to indexing in information retrieval (IR). Retrieval performance using such indexes was compared to the same, but based on indexes produced by static dictionaries. Three Chinese corpora using various character-encoding schemes and language styles were used in the experiments. The results show that retrieval using indexes based on the constructed dictionary is effective. This implies that fully automatic Chinese dictionary construction based on dynamic data sources, e.g., from the Internet, for the purposes of IR is feasible. Drawing on the experiment, we were able to make some interesting observations: (1) using only a portion of a dictionary is enough to produce good retrieval performance, e.g., a dictionary consisting of only the 500 highest-frequency strings extracted from the NTCIR 2 Chinese corpus produced as good a retrieval result as using a more complete dictionary with over 100K entries; and (2) complete word segmentation is not a strict requirement for achieving practical information retrieval.
28736963
Approximate Graph Schema Extraction for Semi-Structured Data
Semi-structured data are typically represented in the form of labeled directed graphs. They are self-describing and schemaless. The lack of a schema renders query processing over semi-structured data expensive. To overcome this predicament, some researchers proposed to use the structure of the data for schema representation. Such schemas are commonly referred to as graph schemas. Nevertheless, since semi-structured data are irregular and frequently subjected to modifications, it is costly to construct an accurate graph schema and worse still, it is difficult to maintain it thereafter. Furthermore, an accurate graph schema is generally very large, hence impractical. In this paper, an approximation approach is proposed for graph schema extraction. Approximation is achieved by summarizing the semi-structured data graph using an incremental clustering method. The preliminary experimental results have shown that approximate graph schemas were more compact than the conventional accurate graph schemas and promising in query evaluation that involved regular path expressions.
45209699
A Workflow Model for Chinese Business Processes
This paper proposes a new workflow model (MAWM) targeted at Chinese business processing. The cultural dependent characteristics of Chinese business processes are identified and taken into account in the MAWM model. MAWM adopts a decentralized modeling style based on the conventional business perspective on labor division and cooperation. This idea is reflected in the concept of agent-workflow. Activity-based and communication-based modeling methods are integrated in the process model. They are used to model different types of business activities. In addition, the model is formalized using Process Algebra and a simplified algorithm is proposed for safety verification of workflow processes.
7493579
CLARE—a Prolog database machine
The CLAuse Retrieval Engine (CLARE) is a coprocessor system which based on two-stage filtering, for handling large sets of disc resident clauses in Prolog database applications. The overall architecture and the timing measurements of the first stage CLARE hardware are reported. The timing measurements shows that the first stage CLARE hardware can perform search operations on data transferring at a rate up to 4.5 million double bytes per second.
15591165
Using an integrated toolset for program understanding
This paper demonstrates the use of an integrated toolset for program understanding. By leveraging the unique capabilities of individual tools, and exploiting their power in combination, the resultant toolset is able to facilitate specific reverse engineering tasks that would otherwise be difficult or impossible. This is illustrated by applying the integrated toolset to several typical reverse engineering scenarios, including code localization, data flow analysis, pattern matching, system clustering, and visualization, using a mid-size production program as the reference system.
337360
Distributed queueing in scalable high performance routers
This paper presents and evaluates distributed queueing algorithms for regulating the flow of traffic through large, high performance routers. Distributed queueing has a similar objective to crossbar-scheduling mechanisms used in routers with relatively small port counts, and shares some common high level characteristics. However, the need to minimize communication overhead rules out the iterative methods that are typically used for crossbar scheduling, while the ability to sub-divide the available bandwidth among different ports provides a degree of freedom that is absent in the crossbar scheduling context, where inputs must be matched to outputs. Our algorithms are based on four ideas (1) backlog-proportional-allocation of output bandwidth, (2) urgency-proportional-allocation of input bandwidth, (3) dynamic reallocation of bandwidth and (4) deferred underflow. Our algorithms guarantee congestion-free operation of the switch fabric. Our performance results show that for uniform random traffic, even a very modest speedup is sufficient to reduce the loss of output link bandwidth due to sub-optimal rate allocation to negligible levels, and that even under extreme conditions, a speedup of two is sufficient to eliminate such bandwidth loss.
34471388
Compressing and Restoring Multiple Images Using Variable Threshold Values
16104056
Performance analysis and design of a logic simulation machine
The high costs associated with logic simulation of large VLSI circuits has led to the need for new computer architectures tailored to the simulation task. Such architectures have the potential for significant speed-ups over software-based logic simulators executing on standard sequential computers. This paper presents a model of one class of multiprocessor simulation architectures and compares the performance of some of these machines using data obtained from simulations of VLSI circuits. In addition, we discuss the implications of our results on machine design and examine the sensitivity of the model to variations in circuit characteristics.
6918962
Head Model Acquisition from Silhouettes
This paper describes a practical system developed for generating 3D models of human heads from silhouettes alone. The input to the system is an image sequence acquired from circular motion. Both the camera motion and the 3D structure of the head are estimated using silhouettes which are tracked throughout the sequence. Special properties of the camera motion and their relationships with the intrinsic parameters of the camera are exploited to provide a simple parameterization of the fundamental matrix relating any pair of views in the sequence. Such a parameterization greatly reduces the dimension of the search space for the optimization problem. In contrast to previous methods, this work can cope with incomplete circular motion and more widely spaced images. Experiments on real image sequences are carried out, showing accurate recovery of 3D shapes.