waashk/acm huggingface dataset:
a general language model for information retrieval  statistical language modeling has been successfully used for speech recognition, part-of- speech tagging, and syntactic parsing. recently, it has also been applied to information retrieval. according to this new paradigm, each document is viewed as a language sample, and a query as a generation process. the retrieved documents are ranked based on the probabilities of producing a query from the corresponding language models of these documents. in this paper, we will present a new language model for information retrieval, which is based on a range of data smoothing techniques, including the good- turning estimate, curve-fitting functions, and model combinations. our model is conceptually simple and intuitive, and can be easily extended to incorporate probabilities of phrases such as word pairs and word triples. the experiments with the wall street journal and trec4 data sets showed that the performance of our model is comparable to that of inquery and better than that of another language model for information retrieval. in particular, word pairs are shown to be useful in improving the retrieval performance.  fei song w. bruce croft
the effect of windows on man-machine interfaces (or opening doors with windows)  a recent development in human-machine interfaces is the partitioning of a computer terminal screen into distinct "windows" of information. this paper defines the concept of "windows" and describes its most common features and applicable operations. it then investigates the utility and application of windowing and compares its features with those of existing user interfaces. the emphasis is on improving the human-machine interface.  richard holcomb alan l. tharp
the impact of database selection on distributed searching  the proliferation of online information resources increases the importance of effective and efficient distributed searching. distributed searching is cast in three parts --- database selection, query processing, and results merging. in this paper we examine the effect of database selection on retrieval performance. we look at retrieval performance in three different distributed retrieval testbeds and distill some general results. first we find that good database selection can result in better retrieval effectiveness than can be achieved in a centralized database. second we find that good performance can be achieved when only a few sites are selected and that the performance generally increases as more sites are selected. finally we find that when database selection is employed, it is not necessary to maintain collection wide information (cwi), e.g. global idf. local information can be used to achieve superior performance. this means that distributed systems can be engineered with more autonomy and less cooperation. this work suggests that improvements in database selection can lead to broader improvements in retrieval performance, even in centralized (i.e. single database) systems. given a centralized database and a good selection mechanism, retrieval performance can be improved by decomposing that database conceptually and employing a selection step.  allison l. powell james c. french jamie callan margaret connell charles l. viles
integrating communication, cooperation, and awareness: the diva virtual office environment  diva, a novel environment for group work, is presented. this prototype virtual office environment provides support for communication, cooperation, and awareness in both the synchronous and asynchronous modes, smoothly integrated into a simple and intuitive interface which may be viewed as a replacement for the standard graphical user interface desktop. in order to utilize the skills that people have acquired through years of shared work in real offices, diva is modeled after the standard office, abstracting elements of physical offices required to support collaborative work: people, rooms, desks, and documents.  markus sohlenkamp greg chwelos
the precedence-assignment model for distributed databases concurrency control algorithms  we have developed a unified model, called the precedence- assignment model (pam), of concurrency control algorithms in distributed database. it is shown that two-phase locking timestamp-ordering and other existing concurrency control algorithms may be modeled by pam. we have also developed a new concurrency control algorithm under the pam modeling framework, which is free from deadlocks and transaction restarts. finally, a unified concurrency control subsystem for precedence-assignment algorithms is developed. by using this subsystem, different transactions may be executed under different concurrency control algorithms simultaneously.  c. p. wang v. o. k. li
concurrency control in a system for distributed databases (sdd-1)  this paper presents the concurrency control strategy of sdd-1. sdd-1, a system for distributed databases, is a prototype distributed database system being developed by computer corporation of america. in sdd-1, portions of data distributed throughout a network may be replicated at multiple sites. the sdd-1 concurrency control guarantees database consistency in the face of such distribution and replication.  this paper is one of a series of companion papers on sdd-1 [4, 10, 12, 21].  philip a. bernstein david w. shipman james b. rothnie
creating a cd-rom from scratch: a case study  technology has moved us to the point where creating a cd-rom as an alternative to paper volumes is not only cost effective, but also provides an opportunity to add significant value to the information presented, both in terms of quantity and usefulness. the past year has been a pivotal one in terms of access to simple and cost- effective tools and technologies that push "personal publishing" of cd-roms closer to reality for a whole range of publishers and information providers. this paper will review the development cycle of spie's first cd-rom product, the electronic imaging '93 proceedings on cd-rom, a hybrid windows/macintosh disc that was created without the use of any of the proprietary (and often expensive) software royalty-based contracts that have been the established turn-key solution until now. the intent of this paper is to provide a first-hand look at the developmental, technical, and financial issues involved in creating a cd-rom publication.  brian j. thomas
commitment in a partitioned distributed database  network partition is among the hardest failure types in a distributed system even if all processors and links are of fail-stop type. we address the transaction commitment problem in a partitioned distributed database. it is assumed that partitions are detectable. the approach taken is conservative - that is, the same transaction cannot be committed by one site and aborted by another.  a new and very general formal model of protocols operating in a partitioned system is introduced and protocols more efficient than the existing ones are constructed.  k. v. s. ramarao
some remarks on variable independence, closure, and orthographic dimension in constraint databases  the notion of variable independence was introduced by chomicki, goldin, and kuper in their pods'96 paper as a means of adding a limited form of aggregation to constraint query languages while retaining the closure property. later, grumbach, rigoux and segoufin showed in their icdt'99 paper that variable independence and a related notion of orthographic dimension are useful tools for optimizing constraint queries.  however, several results in those papers are incorrect as stated. as the notions of variable independence and orthographic dimension appear to be important for implementing constraint database prototypes, i explain in this short note the problems with the above mentioned papers and outline a solution for aggregate closure.  leonid libkin
scalable multimedia delivery for pervasive computing  growing numbers of pervasive devices are gaining access to the internet and other information sources. however, much of the rich multimedia content cannot be easily handled by the client devices with limited communication, processing, storage and display capabilities. in order to improve access, we are developing a system for scalable delivery of multimedia. the system uses an infopyramid for managing and manipulating multimedia content composed of video, images, audio and text. the infopyramid manages the different variations of media objects with different fidelities and modalities and generates and selects among the alternatives in order to adapt the delivery to different client devices. we describe a system for scalable multimedia delivery for a variety of client devices, including pdas, hhcs, smart phones, tv browsers and color pcs.  john r. smith rakesh mohan chung-sheng li
storing hytime documents in an object-oriented databases  an open hypermedia-document storage system has to meet requirements that are not satisfied by existing systems: it has to support non-generic hypermedia document types, i.e. document types enriched with application-specific semantics. it has to provide hypermedia-document access methods. finally, it has to allow the exchange of hypermedia documents with other systems. on a technical level, an object-oriented database-management system, on a logical level, a well established iso standard, namely hytime, is used to satisfy the requirements mentioned above. by means of the example of documents incorporating hypertext structures we discuss the impact of taking such an approach on representation and processing within the database system.  klemens böhm karl aberer
the application of spatialization and spatial metaphor to augmentative and alternative communication  the university of delaware and the university of dundee are collaborating on a project that is investigating the application of spatialization and spatial metaphors to interfaces for augmentative and alternative communication. this paper outlines the project's motivation, goals, and methodological considerations. it presents a number of design principles obtained from a review of the hci literature. finally, it describes progress on the demonstration of this approach. this application called val provides a computer-based word board that retains spatial equivalence to the user's paper-based system. it also allows the user to access an extended lexicon through an interface to the wordnet lexical database.  p. demasco a. f. newell j. l. arnott
talking in circles: designing a spatially-grounded audioconferencing environment  this paper presents _talking in circles_, a multimodal audioconferencing environment whose novel design emphasizes spatial grounding with the aim of supporting naturalistic group interaction behaviors. participants communicate primarily by speech and are represented as colored circles in a two- dimensional space. behaviors such as subgroup conversations and social navigation are supported through circle mobility as mediated by the environment and the crowd and distance-based attenuation of the audio. the circles serve as platforms for the display of identity, presence and activity: graphics are synchronized to participants' speech to aid in speech-source identification and participants can sketch in their circle, allowing a pictorial and gestural channel to complement the audio. we note user experiences through informal studies as well as design challenges we have faced in the creation of a rich environment for computer- mediated communication.  roy rodenstein judith s. donath
improving personal efficiency: time management in today's changing university computing environment  with escalating technological advances and increased computing demands, the director of a university based computing facility finds greater professional responsibilities to perform with somewhat diminishing resources. to partially resolve this imbalance of task and resources, the leaders of computing organizations must seek to utilize their own time as efficaciously as possible. planning to achieve maximum efficiency in a given time frame is a complex and individualized process. even though people react differently to time constraints, each can seek to improve individual productivity within a constant time parameter. practical ways to manage time to improve performance in a changing university computing environment is the theme of this paper.  darleen pigford
an approach to natural gesture in virtual environments  this article presents research---an experiment and the resulting prototype--- on a method for treating gestural input so that it can be used for multimodal applications, such as interacting with virtual environments. this method involves the capture and use of natural , empty-hand gestures that are made during conventional descriptive utterances. users are allowed to gesture in a normal continuous manner, rather than being restricted to a small set of discrete gestural commands as in most other systems. the gestures are captured and analyzed into a higher-level description. this description can be used by an application-specific interpreter to understand the gestural input in its proper context. having a gesture analyzer of this sort enables natural gesture input to any appropriate application.  alan wexelblat
reflective programming in the relational algebra  in reflective programming languages it is possible for a program to generate code that is integrated into the program's own execution. we introduce a reflective version of the relational algebra. reflection is achieved by storing and manipulating relational algebra programs as relations in the database. we then study the expressibility and complexity of the reflective algebra thus obtained. it turns out that there is a close correspondence between reflection and bounded looping. we also discuss the applicability of the reflective algebra.  jan van den bussche dirk van gucht gottfried vossen
statistical profile estimation in database systems  a statistical profile summarizes the instances of a database. it describes aspects such as the number of tuples, the number of values, the distribution of values, the correlation between value sets, and the distribution of tuples among secondary storage units. estimation of database profiles is critical in the problems of query optimization, physical database design, and database performance prediction. this paper describes a model of a database of profile, relates this model to estimating the cost of database operations, and surveys methods of estimating profiles. the operators and objects in the model include build profile, estimate profile, and update profile. the estimate operator is classified by the relational algebra operator (select, project, join), the property to be estimated (cardinality, distribution of values, and other parameters), and the underlying method (parametric, nonparametric, and ad- hoc). the accuracy, overhead, and assumptions of methods are discussed in detail. relevant research in both the database and the statistics disciplines is incorporated in the detailed discussion.  michael v. mannino paicheng chu thomas sager
protocols for integrated audio and shared windows in collaborative systems  this paper describes the architecture and protocols for integrating real-time audio and shared windows in computer-supported cooperative work (cscw) environments. such applications require that actions on shared windows be synchronized with accompanying audio. we give a characterization of this synchronization problem and propose an architecture for handling audio- enhanced cooperative work. we present a protocol for synchronizing the audio stream and window-event streams and evaluate its performance.  a. mathur a. prakash
functionality and architecture of a cooperative database system: a vision  a database system fostering the cooperative usage and modification of a common data pool should provide standard database functionality (e.g. application- independent correctness criteria and data modelling) plus means for a step- wise, cooperative refinement of data over a long period of time. key ingredients are a hierarchical organization of work, a sound data model covering cooperative uncertainly, and support for long-living cooperative processes. furthermore, mechanisms for data passing and hiding, negotiation means, and notification are of prominent importance. in the paper, the rationale behind such a functionality is described. furthermore, a proposal is made for the software architecture of what is called a cooperative database system (cdbms).  thomas kirsche richard lenz hans schuster
a formal approach to the definition and the design of conceptual schemata for databased systems  a formal approach is proposed to the definition and the design of conceptual database diagrams to be used as conceptual schemata in a system featuring a multilevel schema architecture, and as an aid for the design of other forms of schemata. we consider e-r (entity-relationship) diagrams, and we introduce a new representation called caz-graphs. a rigorous connection is established between these diagrams and some formal constraints used to describe relationships in the framework of the relational data model. these include functional and multivalued dependencies of database relations. the basis for our schemata is a combined representation for two fundamental structures underlying every relation: the first defined by its minimal atomic decompositions, the second by its elementary functional dependencies.  the interaction between these two structures is explored, and we show that, jointly, they can represent a wide spectrum of database relationships, of which the well-known one-to-one, one-to-many, and many-to-many associations constitute only a small subset. it is suggested that a main objective in conceptual schema design is to ensure a complete representation of these two structures. a procedure is presented to design schemata which obtain this objective while eliminating redundancy. a simple correspondence between the topological properties of these schemata and the structure of multivalued dependencies of the original relation is established. various applications are discussed and a number of illustrative examples are given.  carlo zaniolo michel a. melkaoff
a cache filtering optimisation for queries to massive datasets on tertiary storage  we consider a system in which many users run queries to examine subsets of a large object set. the object set is partitioned into files on tape. a single subset of objects will be visited by multiple queries in the workload. this locality of access creates the opportunity for caching on disk. we introduce and evaluate a novel optimisation, cache filtering, in which the 'hot' objects are automatically extracted from the files that are staged on disk, and then cached separately in new files on disk. cache filtering can lead to complex situations in the disk cache. we show that these do not prevent effective caching and we introduce a special cache replacement algorithm to maximise efficiency. through simulations we evaluate the system over a broad range of likely workloads. depending on workload and system parameters, the cache filtering optimisation yields speedup factors up to 6.  koen holtman peter van der stok ian willers
an investigation of social loafing and social compensation in computer- supported cooperative work  the effects of computer-mediated communication on social loafing in brainstorming tasks and social compensation in decision-making tasks are examined. in the first experiment, subjects performed a brainstorming task in either nominal, face-to-face or computer- mediated brainstorming group conditions. production blocking, in which brainstorming group members interfere with each other's output, was minimised, but the nominal group still out-performed the other groups. in the second experiment, subjects performed a group decision task in face-to-face and computer mediated communication conditions. social compensation in the presence of social loafing was seen to occur in the first condition, but not in the second. the paper concludes by discussing some of the consequences of both experiments for the future role of computer-mediated communication in group work.  andy mckinlay rob procter anne dunnett
a system for semantic query optimization  this paper describes a scheme to utilize semantic integrity constraints in optimizing a user specified query. the scheme uses a graph theoretic approach to identify redundant join clauses and redundant restriction clauses specified in a user query. an algorithm is suggested to eliminate such redundant joins and avoid unnecessary restrictions. in addition to these eliminations, the algorithm aims to introduce as many restrictions on indexed attributes as possible, thus yielding an equivalent, but potentially more profitable, form of the original query.  sreekumar t. shenoy z. meral ozsoyoglu
the cubic mouse: a new device for three-dimensional input  we have developed a new input device that allows users to intuitively specify three- dimensional coordinates in graphics applications. the device consists of a cube-shaped box with three perpendicular rods passing through the center and buttons on the top for additional control. the rods represent the x, y, and z axes of a given coordinate system. pushing and pulling the rods specifies constrained motion along the corresponding axes. embedded within the device is a six degree of freedom tracking sensor, which allows the rods to be continually aligned with a coordinate system located in a virtual world. we have integrated the device into two visualization prototypes for crash engineers and geologists from oil and gas companies. in these systems the cubic mouse controls the position and orientation of a virtual model and the rods move three orthogonal cutting or slicing planes through the model. we have evaluated the device with experts from these domains, who were enthusiastic about its ease of use.  bernd fröhlich john plate
interfacing realities to the human body (abstract)  almost 25 years ago, the first glimmerings of a revolution in the ways people interact with computers began to appear. however, it was not until the mid-1980s that radically new human interfaces started to be taken seriously. the ultimate computer interface is the human body and the human senses. this idea is now termed virtual reality. the idea works in that it has already changed how people think. the technology is moving rapidly into research labs, but much more slowly into the realm of practical applications. when the ultimate expression of this concept is achieved, any fantasy that can be imagined could be experienced. long before that time, preliminary implementations of the idea will radically change how we interact with computers.  this new technology changes the focus of computer science from the computer to the human. instead of receiving input from a sedentary user, the computer now perceives the behavior of a mobile participant. it allows conceptual information to be presented perceptually. similarly, by immersing the participant in a graphic world, this technology suggests a new approach to a host of old problems. by creating a telecommunication environment in which remote participants can share information as if they are together, it will change how we relate to each other. the advent of virtual reality can be seen as a major cultural event. indeed, it is a medium in which content and aesthetics will be as important as technology.  current virtual reality orthodoxy assumes a goggles-and-gloves approach and is willing to encumber users with as much electronics as necessary to accomplish its purely technical ends. it is not likely that this attitude will succeed in the marketplace. alternative approaches that instrument the environment instead of the body, but provide some of the functionality of virtual reality are more compatible with the existing workplace. it is likely that such approximations of virtual reality will be the first techniques that are widely used.  myron w. krueger