8938753
Toward a progress indicator for program compilation
For user-friendliness purposes, many modern software systems provide progress indicators for longrunning tasks. These progress indicators continuously estimate the percentage of the task that has been completed and when the task will finish. However, none of the existing program compilation tools provide a non-trivial progress indicator, although it often takes minutes or hours to build a large program. In this paper, we investigate the problem of supporting such progress indicators. We first discuss the goals and challenges inherent in this problem. Then we present a set of techniques that are sufficient for implementing a simple yet useful progress indicator for program compilation. Finally, we report on an initial implementation of these techniques in GNU Make. Copyright c © 2006 John Wiley & Sons, Ltd.
7442505
Transaction Reordering and Grouping for Continuous Data Loading
With the increasing popularity of operational data warehousing, the ability to load data quickly and continuously into an RDBMS is becoming more and more important. However, in the presence of materialized join views, loading data concurrently into multiple base relations of the same materialized join view can cause a severe deadlock problem. To solve this problem, we propose reordering the data to be loaded so that at any time, for any materialized join view, data is only loaded into one of its base relations. Also, for load transactions on the relations that contain "aggregate" attributes, we propose using pre-aggregation to reduce the number of SQL statements in the load transactions. The advantages of our methods are demonstrated through experiments with a commercial parallel RDBMS.
11082409
Answering relationship queries on the web
Finding relationships between entities on the Web, e.g., the connections between different places or the commonalities of people, is a novel and challenging problem. Existing Web search engines excel in keyword matching and document ranking, but they cannot well handle many relationship queries. This paper proposes a new method for answering relationship queries on two entities. Our method first respectively retrieves the top Web pages for either entity from a Web search engine. It then matches these Web pages and generates an ordered list of Web page pairs. Each Web page pair consists of one Web page for either entity. The top ranked Web page pairs are likely to contain the relationships between the two entities. One main challenge in the ranking process is to effectively filter out the large amount of noise in the Web pages without losing much useful information. To achieve this, our method assigns appropriate weights to terms in Web pages and intelligently identifies the potential connecting terms that capture the relationships between the two entities. Only those top potential connecting terms with large weights are used to rank Web page pairs. Finally, the top ranked Web page pairs are presented to the searcher. For each such pair, the query terms and the top potential connecting terms are properly highlighted so that the relationships between the two entities can be easily identified. We implemented a prototype on top of the Google search engine and evaluated it under a wide variety of query scenarios. The experimental results show that our method is effective at finding important relationships with low overhead.
14863037
Resource-adaptive real-time new event detection
In a document streaming environment, online detection of the first documents that mention previously unseen events is an open challenge. For this online new event detection (ONED) task, existing studies usually assume that enough resources are always available and focus entirely on detection accuracy without considering efficiency. Moreover, none of the existing work addresses the issue of providing an effective and friendly user interface. As a result, there is a significant gap between the existing systems and a system that can be used in practice. In this paper, we propose an ONED framework with the following prominent features. First, a combination of indexing and compression methods is used to improve the document processing rate by orders of magnitude without sacrificing much detection accuracy. Second, when resources are tight, a resource-adaptive computation method is used to maximize the benefit that can be gained from the limited resources. Third, when the new event arrival rate is beyond the processing capability of the consumer of the ONED system, new events are further filtered and prioritized before they are presented to the consumer. Fourth, implicit citation relationships are created among all the documents and used to compute the importance of document sources. This importance information can guide the selection of document sources. We implemented a prototype of our framework on top of IBM's Stream Processing Core middleware. We also evaluated the effectiveness of our techniques on the standard TDT5 benchmark. To the best of our knowledge, this is the first implementation of a real application in a large-scale stream processing system.
11663917
On iterative intelligent medical search
Searching for medical information on the Web has become highly popular, but it remains a challenging task because searchers are often uncertain about their exact medical situations and unfamiliar with medical terminology. To address this challenge, we have built an intelligent medical Web search engine called iMed, which uses medical knowledge and an interactive questionnaire to help searchers form queries. This paper focuses on iMed's iterative search advisor, which integrates medical and linguistic knowledge to help searchers improve search results iteratively. Such an iterative process is common for general Web search, and especially crucial for medical Web search, because searchers often miss desired search results due to their limited medical knowledge and the task's inherent difficulty. iMed's iterative search advisor helps the searcher in several ways. First, relevant symptoms and signs are automatically suggested based on the searcher's description of his situation. Second, instead of taking for granted the searcher's answers to the questions, iMed ranks and recommends alternative answers according to their likelihoods of being the correct answers. Third, related MeSH medical phrases are suggested to help the searcher refine his situation description. We demonstrate the effectiveness of iMed's iterative search advisor by evaluating it using real medical case records and USMLE medical exam questions.
235091
Efficient detection of empty-result queries
Frequently encountered in query processing, empty query results usually do not provide users with much useful information. Yet, users might still have to wait for a long time before they disappointingly realize that their results are empty. To significantly reduce such unfavorable delays, in this paper, we propose a novel method to quickly detect, without actual execution, those queries that will return empty results. Our key idea is to remember and reuse the results from previously-executed, empty-result queries. These results are stored in the form of so-called atomic query parts so that the (partial) results from multiple queries can be combined together to handle a new query without incurring much overhead. To increase our chance of detecting empty-result queries with only a limited storage, our method (1) stores the most "valuable" information about empty-result queries, (2) removes redundant information among different empty-result queries, (3) continuously updates the stored information to adapt to the current query pattern, and (4) utilizes a set of special properties of empty results. We evaluate the efficiency of our method through a theoretical analysis and an initial implementation in PostgreSQL. The results show that our method has low overhead and can often successfully avoid executing empty-result queries.
2819430
Comments on "Leading-One Prediction with Concurrent Position Correction"
In this report, we first point out and analyse an error in the implementation of the pre-encoding logic in the LOP module proposed in [1], and then present a modification method.
22377735
Failure-Equivalent Transformation of Transition Systems to Avoid Internal Actions
Abstract Labelled transition systems are often used as a theoretical framework for modelling communication protocols or distributed software systems. In order to model the deadlock properties of the systems, the internal transitions of the submodules are often represented globally by so-called internal actions. However, certain verification and testing methods assume that the specification of the system is given in the form of a transition system without internal actions. This paper shows that most labelled transition systems with internal actions can be transformed into a failure-equivalent labelled transition system without internal actions. A sufficient condition is given, and an algorithm is described which does the transformation for any transition system which satisfies the condition. This algorithm can be applied to use the above verification and testing methods also for specification including internal actions.
44490004
Fault Models in Testing
15224900
A Novel Clock Duty-Cycle Corrector of DSP Systems
A novel 50% duty-cycle corrector (DCC) of digital signal processing (DSP) systems, designed with a purely digital phase-blending technique, is presented in this paper. The novel features of the proposed DCC includes a higher reliability against process, voltage and temperature variation due to the use of the synchronous mirror delay (SMD) technique, no-skew output clock, and a much faster duty-cycle correction speed compared to conventional DCC's. When designed with a 0.13-μm CMOS technology, the acceptable duty-cycle of the input signal ranges from 10% to 90% when the clock frequency is 400 MHz and the correction operation spends 4 clock cycles with the corrected duty-cycle varying from 48% to 52%.
10608907
Development and Evaluation of Vision Multiplexing Devices for Vision Impairments
We have proposed a novel concept of vision multiplexing for the visually impaired - superimposing contour images over their natural view of a scene or over original images presented on a TV screen. We have implemented the concept using an optical see-through head mounted display to provide either visual field expansion to patients with peripheral field loss or vision enhancement to patients with central vision loss. We have also implemented the concept in a video player with dynamic magnification for patients with central vision loss. Results of initial testing in the lab and on the street are promising.