waashk/acm huggingface dataset:
pragmatic solutions for better integration of the visually impaired in virtual communities  this article introduces and discusses issues in the design of user interfaces for visually impaired people in the domain of virtual communities. we begin by pointing out that collaborative virtual environments provide additional means for visually impaired people which may help to accomplish a better integration into existing communities and social activities. we give a short introduction to the way visually impaired people usually work with a pc and show how their method of information access differs to sighted people. we then take a look at the advantages and disadvantages of existing adaptations to operating systems. based on this analysis we describe some requirements for user interfaces the usability for visually impaired people without losing the attractiveness and intuitiveness for the sighted. we finally describe a prototype of a special irc-client, called birc, and discuss its advantages and limitations.  thorsten hampel reinhard keil-slawik bastian ginger claassen frank plohmann christian reimann
type-syntax and token-syntax in diagrammatic systems while it is crucial to understand the formal structure of thesemantic domain of an information system, in this paper we raise anontological issue about the syntactic aspect of a representationsystem through a case study on a diagrammatic system. the uptake inthe software industry of notations for designing systems visuallyhas been accelerated with the standardization of the unifiedmodeling language (uml). the formalization of diagrammaticnotations is important for the development of essential toolsupport and to allow reasoning to take place at the diagrammaticlevel. focusing on an extended version of venn and eulerdiagram(which was developed to complement uml in the specificationof software systems), this paper presents two levels of syntax forthis system: type-syntax and token-syntax. token-syntax is aboutparticular diagrams instantiated on some physical medium, andtype-syntax provides a formal definition with which a concreterepresentation of a diagram must comply. while these two levels ofsyntax are closely related, the domains of type-syntax andtoken-syntax are ontologically independent, that is, one isabstract and the other concrete. we discuss the roles oftype-syntax and token-syntax in diagrammatic systems and show thatit is important to consider both levels of syntax in diagrammaticreasoning systems and in developing software tools to support suchsystems. john howse fernando molina john taylor sun-joo shin
associative hardware and software techniques for integrity control  this paper presents the integrity control mechanism of the associative processing system, cassm. the mechanism takes advantage of the associative techniques, such as content and context addressing, tagging and marking data, parallel processing, automatic triggering of integrity control procedures, etc., for integrity control and as a result offers three significant advantages: (1) the problem of staging data in a main memory for integrity checking can be eliminated because database storage operations are verified at the place where the data are stored. (2) the backout or merging procedures are relatively easy and inexpensive in the associative system because modified copies can be substituted for the originals or may be discarded by merely changing their associated tags. (3) the database management system software is simplified because database integrity functions are handled by the associative processing system to which a mainframe computer is a front-end computer.  y. c. hong stanley y. w. su
compensation-based on-line query processing  it is well known that using conventional concurrency control techniques for obtaining serializable answers to long-running queries leads to an unacceptable drop in system performance. as a result, most current dbmss execute such queries under a reduced degree of consistency, thus providing non-serializable answers. in this paper, we present a new and highly concurrent approach for processing large decision support queries in relational databases. in this new approach, called compensation-based query processing, concurrent updates to any data participating in a query are communicated to the query's on-line query processor, which then compensates for these updates so that the final answer reflects changes caused by the updates. very high concurrency is achieved by locking data only briefly, while still delivering transaction-consistent answers to queries.  v. srinivasan michael j. carey
a retrospective on the development of star  star, officially known as the xerox 8010 information system, is a workstation for professionals, providing a comprehensive set of capabilities for the office environment. the star software consists of just over 250,000 lines of code. its development required 93 work years over a 3.5 year period.  the development of star depended heavily on the use of powerful personal computers connected to a local-area network and on the use of the mesa language and development environment. an integration service was introduced to speed up the building of star and to relieve the programmers of many complex, but repetitive, tasks.  eric harslem leroy e. nelson
hybrid inferential security methods for statistical databases memoryless inference control methods have been shown to provide effective means of reducing the amount of sensitive information released from a statistical database while maximizing the release of non-sensitive information. early memoryless inference controls have the additional benefit of providing control at a low computation and storage cost. two recent extensions to memoryless inference control allow the controls to release more non-sensitive information but do so at a greater cost in terms of computation and storage. this paper describes a proposed hybrid inference control method that can potentially maximize the release of information while holding down computation costs. steven c. hansen
real world performance of association rule algorithms this study compares five well-known association rule algorithms using three real-world datasets and an artificial dataset. the experimental results confirm the performance improvements previously claimed by the authors on the artificial data, but some of these gains do not carry over to the real datasets, indicating overfitting of the algorithms to the ibm artificial dataset. more importantly, we found that the choice of algorithm only matters at support levels that generate more rules than would be useful in practice. for support levels that generate less than 1,000,000 rules, which is much more than humans can handle and is sufficient for prediction purposes where data is loaded into ram, apriori finishes processing in less than 10 minutes. on our datasets, we observed super-exponential growth in the number of rules. on one of our datasets, a 0.02% change in the support increased the number of rules from less than a million to over a billion, implying that outside a very narrow range of support values, the choice of algorithm is irrelevant. zijian zheng ron kohavi llew mason
murax: a robust linguistic approach for question answering using an on-line encyclopedia  robust linguistic methods are applied to the task of answering closed-class questions using a corpus of natural language. the methods are illustrated in a broad domain: answering general-knowledge questions using an on-line encyclopedia.  a closed-class question is a question stated in natural language, which assumes some definite answer typified by a noun phrase rather than a procedural answer. the methods hypothesize noun phrases that are likely to be the answer, and present the user with relevant text in which they are marked, focussing the user's attention appropriately. furthermore, the sentences of matching text that are shown to the user are selected to confirm phrase relations implied by the question, rather than being selected solely on the basis of word frequency.  the corpus is accessed via an information retrieval (ir) system that supports boolean search with proximity constraints. queries are automatically constructed from the phrasal content of the question, and passed to the ir system to find relevant text. then the relevant text is itself analyzed; noun phrase hypotheses are extracted and new queries are independently made to confirm phrase relations for the various hypotheses.  the methods are currently being implemented in a system called murax and although this process is not complete, it is sufficiently advanced for an interim evaluation to be presented.  julian kupiec
tolerating bounded inconsistency for increasing concurrency in database systems  recently, the scope of databases has been extended to many non-standard applications, and serializability is found to be too restrictive for such applications. in general, two approaches are adopted to address this problem. the first approach considers placing more structure on data objects to exploit type specific properties while keeping serializability as the correctness criterion. the other approach uses explicit semantics of transactions and databases to permit interleaved executions of transactions that are non- serializable. in this paper, we attempt to bridge the gap between the two approaches by using the notion of serializability with bounded inconsistency. users are free to specifiy the maximum level of inconsistency that can be allowed in the executions of operations dynamically. in particular, if no inconsistency is allowed in the execution of any operation, the protocol will be reduced to a standard strict two phase locking protocol based on type- specific semantics of data objects. bounded inconsistency can be applied to many areas which do not require exact values of the data such as for gathering information for statistical purpose, for making high level decisions and reasoning in expert systems which can tolerate uncertainty in input data.  m. h. wong d. agrawal
dynamic information visualization  dynamic queries constitute a very powerful mechanism for information visualization; some universe of data is visualized, and this visualization is modified on-the-fly as users modify the range of interest within the domains of the various attributes of the visualized information. in this paper, we analyze dynamic queries and offer some natural generalizations of the original concept by establishing a connection to sql. we also discuss some implementation ideas that should make these generalizations efficient as well.  yannis e. ioannidis
efficient commit protocols for the tree of processes model of distributed transactions  this paper describes two efficient distributed transaction commit protocols, the presumed abort (pa) and presumed commit (pc) protocols, which have been implemented in the distributed data base system r* [dshlm82, lhmwy83]. pa and pc are extensions of the well-known two-phase (2p) commit protocol [gray78, lamp80, lsggl80]. pa is optimized for read-only transactions and a class of multi-site update transactions, and pc is optimized for other classes of multi-site update transactions. the optimizations result in reduced inter-site message traffic and log writes, and, consequently, a better response time for such transactions. we derive the new protocols in a step-wise fashion by modifying the 2p protocol.  c. mohan b. lindsay
query processing in a multimedia document system  query processing in a multimedia document system is described. multimedia documents are information objects containing formatted data, text, image, graphics, and voice. the query language is based on a conceptual document model that allows the users to formulate queries on both document content and structure. the architecture of the system is outlined, with focus on the storage organization in which both optical and magnetic devices can coexist. query processing and the different strategies evaluated by our optimization algorithm are discussed.  elisa bertino fausto rabbiti simon gibbs
converting nested algebra expressions into flat algebra expressions  nested relations generalize ordinary flat relations by allowing tuple values to be either atomic or set valued. the nested algebra is a generalization of the flat relational algebra to manipulate nested relations. in this paper we study the expressive power of the nested algebra relative to its operation on flat relational databases. we show that the flat relational algebra is rich enough to extract the same "flat information" from a flat database as the nested algebra does. theoretically, this result implies that recursive queries such as the transitive closure of a binary relation cannot be expressed in the nested algebra. practically, this result is relevant to (flat) relational query optimization.  jan paredaens dirk van gucht
performance enhancements to a relational database system  in this paper we examine four performance enhancements to a database management system: dynamic compilation, microcoded routines, a special-purpose file system, and a special-purpose operating system. all were examined in the context of the ingres database management system. benchmark timings that are included suggest the attractiveness of dynamic compilation and a special- purpose file system. microcode and a special-purpose operating system are analyzed and appear to be of more limited utility in the ingres context.  michael stonebraker john woodfill jeff ranstrom marguerite murphy marc meyer eric allman
concepts and methods for the optimization of distributed data processing  in this paper we introduce and discuss a model of distributed data processing. for this purpose, a typical application system is analyzed and divided into sub-applications. to fulfill the task of the global application, the sub- applications have to communicate in an appropriate manner by exchanging data resp. information. in our model the communication between sub- applications is split up into two steps: the offering of information by sending sub- applications, and its acceptance by receiving sub-applications. for both communication steps synchronous and asynchronous processing modes are defined. supporting those different communication modes the cooperation between sub- applications can be defined very closely to the specific demands of the application system. this optimizes distributed data processing. at last we demonstrate the prototype implementation of a distributed data management system, which is based on the flexible communication mechanism described in the paper.  s. jablonski t. ruf h. wedekind
panel on multimedia computer mail - technical issues and future standards  a computer-based message system (cbms) consists of computer facilities that expedite the creation, management, and nonreal time distribution of messages. these systems are increasingly being used for formal and informal communication, supporting the distribution of textual messages. however, nontext media such as voice and graphics are very important for human interaction, and are becoming more and more important in computer system applications. as a result, there is a growing need for the support of media other than text in cbms.  before standards for multimedia cbms can be implemented, there are many technical issues that must be addressed. these range from the design of new mechanisms for the distribution of multimedia mail, to the design of tools needed for editing nontext media. this panel will be discussing issues encountered in the development of multimedia cbms and an outlook for standards for multimedia computer mail.  franklin f. kuo debra p. deutsch harry c. forsdick j. j. garcia luna aceves najah naffah andrew poggio jonathan b. postel james e. white
another approach to the data base computer  data base computers have been identified as one means of using hardware to improve the performance of current data base management (software) systems while offering increased functionality. this paper describes a data base computer architecture and its operation that was developed during one of sperry univac's research efforts in this area. parallel transfer of large blocks of data which are then processed in parallel on a content-addressable basis by a series of microprocessors is the key to this design. the data base computer described in this paper is indicative of the special-purpose devices that will be available to meet the information storage and processing needs of the 1980s.  harvey a. freeman john r. jordan
towards estimation error guarantees for distinct values  we consider the problem of estimating the number of distinct values in a column of a table. for large tables without an index on the column, random sampling appears to be the only scalable approach for estimating the number of distinct values. we establish a powerful negative result stating that no estimator can guarantee small error across all input distributions, unless it examines a large fraction of the input data. in fact, any estimator must incur a significant error on at least some of a natural class of distributions. we then provide a new estimator which is provably optimal, in that its error is guaranteed to essentially match our negative result. a drawback of this estimator is that while its worst-case error is reasonable, it does not necessarily give the best possible error bound on any given distribution. therefore, we develop heuristic estimators that are optimized for a class of typical input distributions. while these estimators lack strong guarantees on distribution-independent worst-case error, our extensive empirical comparison indicate their effectiveness both on real data sets and on synthetic data sets.  moses charikar surajit chaudhuri rajeev motwani vivek narasayya
office automation: new arena for old struggle  office work accounts for one-half of the total employment in the united states. in 1978 there were 15.6 million professional and technical workers, 8.8 million managers and administrators, 6.4 million salesworkers, and 17.8 million clerical workers, for a grand total of 48.6 million white-collar employees constituting 49.8 percent of all workers. 1 the bureau of labor statistics projects an increase in this category of at least 24.9 percent, compared with 18.6 percent for blue-collar workers, 31.4 percent for service workers, and a decline of about 21 percent for farm workers. although service occupations are expected to be the fastest growing occupational group during 1978-1990, the largest number of new jobs will occur in the white- and blue- collar categories. the former is expected to increase by 12.1 to 16.1 million jobs; the latter by 5.9 to 8.9 million.  abbe mowshowitz
a synchronization model for recorded presentations and its relevance for information retrieval  in order to improve the acceptance of recorded presentations, we introduce a new open document type covering a wide range of different media classes typically appearing in this scenario. instances of this document type can be replayed using our time-based synchronization model. random access in combination with the realized stream/media-layered synchronization mechanism results in essential features such as random visible scrolling and unrestricted cross-referencing. the proposed synchronization model has been implemented and is routinely used by a variety of institutions. furthermore we show how the properties of the considered documents and the functionality of the proposed synchronization model affect cross-modal retrieval techniques.  w. hurst r. muller
a loosely-coupled integration of a text retrieval system and an object- oriented database system  document management systems are needed for many business applications. this type of system would combine the functionality of a database system, (for describing, storing and maintaining documents with complex structure and relationships) with a text retrieval system (for effective retrieval based on full text). the retrieval model for a document management system is complicated by the variety and complexity of the objects that are represented. in this paper, we describe an approach to complex object retrieval using a probabilistic inference net model, and an implementation of this approach using a loose coupling of an object-oriented database system (iris) and a text retrieval system based on inference nets (inquery). the resulting system is used to store long, structured documents and can retrieve document components (sections, figures, etc.) based on their contents or the contents of related components. the lessons learnt from the implementation are discussed.  w. bruce croft lisa a. smith howard r. turtle
extending complex ad-hoc olap  large scale data analysis and mining activities require sophisticated information extraction queries. many queries require complex aggregation, and many of these aggregates are non- distributive. conventional solutions to this problem involve defining user defined aggregate functions (udafs). however, the use of udafs entails several problems. defining a new udaf can be a significant burden for the user, and optimizing queries involving udafs is difficult because of the "black box" nature of the udaf.  in this paper, we present a method for expressing nested aggregates in a declarative way. a nested aggregate, which is a rollup of another aggregated value, expresses a wide range of useful non-distributive aggregation. for example, most frequent type aggregation can be naturally expressed using nested aggregation, e.g. "for each product, report its total sales during the month with the largest total sales of the product". by expressing compex aggregates declaratively, we relieve the user of the burden of defining udafs, and allow the evalution of the complex aggregates to be optimized.  we use the extended multi-feature (emf) syntax as the basis for expressing nested aggregation. an advantage of this approach is that emf sql can already express a wide range of complex aggregation in a succinct way, and emf sql is easily optimized into efficient query plans. we show that nested aggregation queries can be evaluated efficiently by using a small extension to the emf sql query evaluation algorithm. a side effect of this extension is to extend emf sql to permit complex aggregation of data from multiple sources.  theodore johnson damianos chatziantoniou
how do experienced information lens users use rules?  the information lens provides electronic mail users with the ability to write rules that automatically sort, select, and filter their messages. this paper describes preliminary results from an eighteen-month investigation of the use of this system at a corporate test site. we report the experiences of 13 voluntary users who have each had at least three months experience with the most recent version of the system. we found that:  people without significant computer experience are able to create and use rules effectively.  useful rules can be created based on the fields present in all messages (e.g., searching for distribution lists or one's own name in the address fields or for character strings in the subject field), even without any special message templates.  people use rules both to prioritize messages before reading them and to sort messages into folders for storage after reading them.  people use delete rules primarily to filter out messages from low-priority distribution lists, not to delete personal messages to themselves.  w. e. mackay t. w. malone k. crowston r. rao d. rosenblitt s. k. card