waashk/acm huggingface dataset:
design of a multi-media vehicle for social browsing  in this paper we present a new approach to the use of computer-mediated communications technology to support distributed cooperative work. in contrast to most of the existing approaches to cscw, we focus explicitly on tools to enable unplanned, informal social interaction. we describe a "social interface" which provides direct, low-cost access to other people through the use of multi-media communications channels. the design of the system centers around three basic concepts derived from the research literature and our own observations of the workplace: social browsing, a virtual workplace, and interaction protocols. we use these design properties to describe a new system concept, and examine the implications for cscw of having automated social interaction available through the desktop workstation.  robert w. root
support for fully interactive playout in disk-array-based video server  in a video-on-demand (vod) system, it is desirable to provide the user with interactive browsing functions such as "fast forward" and "fast backward." however, these functions usually require a significant amount of additional resources from the vod system in terms of storage space, retrieval throughput, network bandwidth, etc. moreover, prevalent video compression techniques such as mpeg impose additional constraints on the process since they introduce inter-frame dependencies. in this paper, we devise methods to support variable rate browsing for mpeg-like video steams and minimize the additional resources required. specifically, we consider retrieval for a disk-array-based video server and address the problem of distributing the retrieval requests across the disks.  our overall approach for interactive browsing comprises (1) a storage method, (2) placement and sampling methods, and (3) a playout method, where the placement and sampling methods are two alternatives for video segment selection. the segment sampling scheme supports browsing at any desired speed, while minimizing the variation on the number of video segments skipped between samplings. on the other hand, the segment placement scheme supports completely uniform segment sampling across the disk array for some specific speedup rates. experiments for the visual effect of the proposed segment skipping approach have been conducted on mpeg data. it is shown that the proposed method is a viable approach to video browsing.  m.-s. chen d. kandlur p. yu
optimization of constrained frequent set queries with 2-variable constraints  currently, there is tremendous interest in providing ad-hoc mining capabilities in database management systems. as a first step towards this goal, in [15] we proposed an architecture for supporting constraint-based, human-centered, exploratory mining of various kinds of rules including associations, introduced the notion of constrained frequent set queries (cfqs), and developed effective pruning optimizations for cfqs with 1-variable (1-var) constraints.  while 1-var constraints are useful for constraining the antecedent and consequent separately, many natural examples of cfqs illustrate the need for constraining the antecedent and consequent jointly, for which 2-variable (2-var) constraints are indispensable. developing pruning optimizations for cfqs with 2-var constraints is the subject of this paper. but this is a difficult problem because: (i) in 2-var constraints, both variables keep changing and, unlike 1-var constraints, there is no fixed target for pruning; (ii) as we show, "conventional" monotonicity-based optimization techniques do not apply effectively to 2-var constraints.  the contributions are as follows. (1) we introduce a notion of quasi- succinctness, which allows a quasi-succinct 2-var constraint to be reduced to two succinct 1-var constraints for pruning. (2) we characterize the class of 2-var constraints that are quasi-succinct. (3) we develop heuristic techniques for non-quasi-succinct constraints. experimental results show the effectiveness of all our techniques. (4) we propose a query optimizer for cfqs and show that for a large class of constraints, the computation strategy generated by the optimizer is ccc-optimal, i.e., minimizing the effort incurred w.r.t. constraint checking and support counting.  laks v. s. lakshmanan raymond ng jiawei han alex pang
cognitive differences in end user searching of a cd-rom index  cognitive abilities of fifty university students were tested using eight tests from the kit of factor-referenced cognitive tests. all students searched for references on the same topic using a standard computerized index, and performance in the searches was analyzed using a variety of measures. effects for cognitive differences, as well as for differences in demographic characteristics and knowledge, were identified using multiple regression. perceptual speed had an effect on the quality of searches, and logical reasoning, verbal comprehension, and spatial scanning abilities influenced search tactics. it is suggested that information retrieval systems can be made more accessible to users with different levels of cognitive abilities through improvements that will assist users to scan lists of terms, choose appropriate vocabulary for searching, and select useful references.  bryce allen
advanced capabilities of the outer join  this paper demonstrates that the modeling of complex data structures can be performed easily and naturally in sql using the direct outer join operation as defined in the proposed iso- ansi sql2 standard. this paper goes on to demonstrate four advanced capabilities that can be implemented by sql vendors utilizing the data modeling ability of the outer join. these capabilities are: powerful optimization techniques that can dynamically shorten the access path length; intelligent join view updates that utilize the semantics in the data structure being modeled; direct disparate heterogeneous database access that is transparent and efficient; and automatic conversion of multi-table structures into nested relations allowing for more powerful sql operations.  michael m. david
the friendly intelligent tutoring environment the advancement of using the artificial intelligence (ai) methods and techniques in design intelligent tutoring systems (itss) makes understanding them more difficult, so that teachers are less and less prepared to accept these systems. as a result, the gap between researchers in the field of itss and the educational community is constantly widening. while itss are becoming more common and proving to be increasingly effective, each one must still be built from scratch at a significant cost. also present itss need quite big development environments, huge computing resources and, in consequence, are expensive and hardly portable to personal computers. this paper describes our efforts toward developing uniform data, explanation and control structures that can be used by a wide circle of authors who are involved in building itss (e.g., domain experts, teachers, curriculum developers, etc.) that is, the model of the itss framework, the **get-bits** model. ljubomir jerinic vladan devedzic
a uniform approach toward handling atomic and structured information in the nested relational database model  the algebras and query languages for nested relations defined thus far do not allow us to "flatten" a relation scheme by disregarding the internal representation of data. in real life, however, the degree in which the structure of certain information, such as addresses, phone numbers, etc., is taken into account depends on the particular application and may even vary in time. therefore, an algebra is proposed that does allow us to simplify relations by disregarding the internal structure of a certain class of information. this algebra is based on a careful manipulation of attribute names. furthermore, the key operator in this algebra, called "copying," allows us to deal with various other common queries in a very uniform manner, provided these queries are interpreted as operations on classes of semantically equivalent relations rather than individual relations. finally, it is shown that the proposed algebra is complete in the sense of bancilhon and paredaens.  marc gyssens dirk van gucht
the mre wrapper approach: enabling incremental view maintenance of data warehouses defined on multi-relation information sources  some of the most recently proposed algorithms for the incremental maintenance of materialized data warehouses (dw), such as sweep and psweep, offer several significant advantages over previous solutions, such as high-performance, no potential for infinite waits and reduced remote queries and thus reduced network and information source (is) loads. however, similar to many other algorithms, they still have the restricting assumption that each is can be composed of just one single relation. this is unrealistic in practice. in this paper, we hence propose a solution to overcome this restriction. the multi- relation encapsulation (mre) wrapper supports multiple relations in iss in a manner transparent to the rest of the environment. the mre wrapper treats one is composed of multiple relations as if it were a single relation from the dw point of view; thus any existing incremental view maintenance algorithms can now be applied even to such complex iss without any changes. hence, our method maintains all advantages offered by existing algorithms in particular sweep and psweep, while also achieving the additional desired features of being non- intrusive, efficient, flexible and well-behaved.  lingli ding xin zhang elke a. rundensteiner
an access control model supporting periodicity constraints and temporal reasoning  access control models, such as the ones supported by commercial dbmss, are not yet able to fully meet many application needs. an important requirement derives from the temporal dimension that permissions have in many real-world situations. permissions are often limited in time or may hold only for specific periods of time. in this article, we present an access control model in which periodic temporal intervals are associated with authorizations. an authorization is automatically granted in the specified intervals and revoked when such intervals expire. deductive temporal rules with periodicity and order constraints are provided to derive new authorizations based on the presence or absence of other authorizations in specific periods of time. we provide a solution to the problem of ensuring the uniqueness of the global set of valid authorizations derivable at each instant, and we propose an algorithm to compute this set. moreover, we address issues related to the efficiency of access control by adopting a materialization approach. the resulting model provides a high degree of flexibility and supports the specification of several protection requirements that cannot be expressed in traditional access control models.  elisa bertino claudio bettini elena ferrari pierangela samarati
a survey of distributed deadlock detection algorithms  this paper surveys research work performed within the last five years in distributed deadlock detection. the last survey paper on this topic appeared in 1980; since that time a large number of interesting algorithms have been discribed in the literature. a new, more efficient scheme is the probe-based deadlock detection strategy used by many of the new algorithms. this paper will concentrate on distributed deadlock detection algorithms. only detection of resource deadlocks will be reviewed here, though other types of deadlock handling strategies and environments are briefly mentioned.  ahmed k. elmagarmid
user-defined music sequence retrieval  a system for retrieving a sequence of music excerpts or songs based on users and producers requirements is proposed in this paper. our system provides a flexible way to retrieve music pieces based on its contents as well as user- defined constraints. the proposed system allows online users to extract a sequence of songs whose first and last tracks are known and at the same time the in-between songs have minimum inter-track differences and satisfy predefined requirements. we model the problem as a constrained minimum cost flow problem which leads to a binary integer linear program (bilp) that can be solved in a reasonable amount of time.  masoud alghoniemy ahmed h. tewfik
incremental relevance feedback  although relevance feedback techniques have been investigated for more than 20 years, hardly any of these techniques has been implemented in a commercial full-text document retrieval system. in addition to pure performance problems, this is due to the fact that the application of relevance feedback techniques increases the complexity of the user interface and thus also the use of a document retrieval system. in this paper we concentrate on a relevance feedback technique that allows easily understandable and manageable user interfaces, and at the same time provides high-quality retrieval results. moreover, the relevance feedback technique introduced unifies as well as improves other well-known relevance feedback techniques.  ijsbrand jan aalbersberg
life and death of new technology: task, utility and social influences on the use of a communication medium  this field experiment investigates individual, structural and social influences on the use of two video telephone systems. one system flourished, while an equivalent system died. we use a time series design and multiple data sources to test media richness theory, critical mass theory, and social influence theories about new media use. results show that the fit between tasks and features of the communications medium influences use to a degree, but cannot explain why only one system survived. critical mass---the numbers of people one can reach on a system--- and social influence---the norms that grow up around a new medium---can explain this phenomenon.  robert e. kraut ronald e. rice colleen cool robert s. fish
functional completeness in object-oriented databases  a definition of completeness in the context of object oriented databases (oodbs) is proposed in this paper. it takes into account the existence of various categories of functions in oodbs, each of which must be complete in itself. the functionality of an oodb can be divided into sets of related functions. for example, functions needed to perform all schema evolution operations or all version management operations belong in two distinct sets. further, each set of functions must include all functions needed to perform all operations defined for that set. thus, for an oodb to be functionally complete, it must support a certain number of sets (or categories) of functions and each such set must be complete in itself. the purpose of this paper is not to give a precise definition of the categories of functions but rather to define a framework within which such categories should be examined. this paper contains a working definition of functional completeness. we would welcome any feedback on our proposal.  priti mishra margaret eich
niagaracq: a scalable continuous query system for internet databases  continuous queries are persistent queries that allow users to receive new results when they become available. while continuous query systems can transform a passive web into an active environment, they need to be able to support millions of queries due to the scale of the internet. no existing systems have achieved this level of scalability. niagaracq addresses this problem by grouping continuous queries based on the observation that many web queries share similar structures. grouped queries can share the common computation, tend to fit in memory and can reduce the i/o cost significantly. furthermore, grouping on selection predicates can eliminate a large number of unnecessary query invocations. our grouping technique is distinguished from previous group optimization approaches in the following ways. first, we use an incremental group optimization strategy with dynamic re-grouping. new queries are added to existing query groups, without having to regroup already installed queries. second, we use a query-split scheme that requires minimal changes to a general-purpose query engine. third, niagaracq groups both change-based and timer-based queries in a uniform way. to insure that niagaracq is scalable, we have also employed other techniques including incremental evaluation of continuous queries, use of both pull and push models for detecting heterogeneous data source changes, and memory caching. this paper presents the design of niagaracq system and gives some experimental results on the system's performance and scalability.  jianjun chen david j. dewitt feng tian yuan wang
a visual interface for a database with version management  this paper describes a graphical interface to an experimental database system which incorporates a built-in version control mechanism that maintains a history of the database development and changes. the system is an extension of isis [6], interface for a semantic information system, a workstation-based, graphical database programming tool developed at brown university. isis supports a graphical interface to a modified subset of the semantic data model (sdm) [7]. the isis extension introduces a transaction mechanism that interacts with the version control facilities.  a series of version control support tools have been added to isis to provide a notion of history to user- created databases. the user can form new versions of three types of isis objects: a class definition object (a type), the set of instances of a class (the content), and an entity. a version-viewing mechanism is provided to allow for the comparison of various object versions. database operations are grouped together in atomic units to form transactions, which are stored as entities in the database. a sample session demonstrates the capabilities of version and transaction control during the creation and manipulation of database objects.  jay w. davison stanley b. zdonik
orienteering in an information landscape: how information seekers get from here to there  we studied the uses of information search results by regular clients of professional intermediaries. the clients in our study engaged in three different types of searches: (1) monitoring a well-known topic or set of variables over time, (2) following an information-gathering plan suggested by a typical approach to the task at hand, and (3) exploring a topic in an undirected fashion. in most cases, a single search evolved into a series of interconnected searches, usually beginning with a high-level overview. we identified a set of common triggers and stop conditions for further search steps. we also observed a set of common operations that clients used to analyze search results. in some settings, the number of search iterations was reduced by restructuring the work done by intermediaries. we discuss the implications of the interconnected search pattern, triggers and stop conditions, common analysis techniques, and intermediary roles for the design of information access systems.  vicki l. o'day robin jeffries
heterogeneous databases and high level abstraction  a heterogeneous database management system combines multiple dissimilar models of data within a single integrated system. the objective is to allow a user to access data independently of how it is actually organized. for example, a user may access a database as though it were stored relationally (i.e., in tables) [codd70], even though it is actually stored as a codasyl/dbtg or network database [coda71]. in addition, different subpieces of the database may be organized under different data models. the heterogeneous database system must present these to the user as an integrated whole. the user's model of his data may be different from any of the models chosen to implement it.  rather than construct a new database system from scratch, we are interested in constructing a heterogeneous system out of existing systems. the key difficulties with this approach are: (1) the formulation of database design methods that are applicable to a variety of different data models, and (2) the development of techniques to translate programs and data between dissimilar data models. in this paper, we briefly describe how high level abstraction has been applied to these problems. the use of abstraction in database systems is related to the application of abstraction techniques in programming languages and artificial intelligence research.  randy h. katz
behavioral evaluation of cscw technologies (tutorial session)(abstract only)  goals and objectives: evaluating cscw systems is much more difficult than evaluating single-user systems because of the additional group and organizational factors. behavioral evaluation consists of having people use cscw technologies under appropriate conditions and gathering either qualitiative or quantitative information about their behavior.  we will examine a variety of methods, including case studies, large scale field studies, surveys, and laboratory studies.  tom finholt gary olson judy olson
access by content of documents in an office information system  this paper presents the integration of retrieval functions of an information retrieval system, iota, in an office information server. besides the linear scanning of the text (using a software and a hardware filter), two access methods are proposed. the first one is based on a simple indexing of documents based on signatures. here, texts are treated as character strings. we call this method textual search. the second one is based on the extention of signature methods for implementing the indexing relation of iota, where meaningful terms (noun groups, for example) are identified in the text together with grammatical information. we call this method of signature computation the indexing-term signature. the resulting access method is called semantic search. we present the current experimentations using the schuss hardware filter as a scanning accelerator and the results of different alternatives of implementation of these retrieval functions.  c. jimenez guarin
continuous queries over append-only databases  in a database to which data is continually added, users may wish to issue a permanent query and be notified whenever data matches the query. if such continuous queries examine only single records, this can be implemented by examining each record as it arrives. this is very efficient because only the incoming record needs to be scanned. this simple approach does not work for queries involving joins or time. the tapestry system allows users to issue such queries over a database of mail and bulletin board messages. the user issues a static query, such as "show me all messages that have been replied to by jones," as though the database were fixed and unchanging. tapestry converts the query into an incremental query that efficiently finds new matches to the original query as new messages are added to the database. this paper describes the techniques used in tapestry, which do not depend on triggers and thus be implemented on any commercial database that supports sql. although tapestry is designed for filtering mail and news messages, its techniques are applicable to any append-only database.  douglas terry david goldberg david nichols brian oki