waashk/acm huggingface dataset:
computer communication system design affects group decision making  the impact of computer-based communication on group performance depends upon the structure enforced by the communication system. while the ability to introduce structures which enhance human communication processes has been applauded, research to evaluate the impact of various design features is lacking. this research has explored the impact of two synchronous systems which vary in the role of immediacy of interaction and feedback on group decision making. one system is message-oriented, requiring a conferee to complete a message before interacting with others. the other displays what each group member is typing in a separate window on the screens of all participants. in this system, comments can be made as ideas are expressed. groups were asked to solve a problem first individually and then cooperatively using one of the two systems. all groups produced decisions superior to the average initial individual solutions. window system groups both improved more and produced significantly higher quality decisions. these groups focused on fewer topics at one time while spending less time discussing how to organize both system and task efforts. by influencing the group's ability to organize and focus its attention, the design of the communication system influenced decision quality.  sharon murrel
baroque: a browser for relational databases  the standard, most efficient method to retrieve information from databases can be described as systematic retrieval: the needs of the user are described in a formal query, and the database management system retrieves the data promptly. there are several situations, however, in which systematic retrieval is difficult or even impossible. in such situations exploratory search (browsing) is a helpful alternative. this paper describes a new user interface, called baroque, that implements exploratory searches in relational databases. baroque requires few formal skills from its users. it does not assume knowledge of the principles of the relational data model or familiarity with the organization of the particular database being accessed. it is especially helpful when retrieval targets are vague or cannot be specified satisfactorily. baroque establishes a view of the relational database that resembles a semantic network, and provides several intuitive functions for scanning it. the network integrates both schema and data, and supports access by value. baroque can be implemented on top of any basic relational database management system but can be modified to take advantage of additional capabilities and enhancements often present in relational systems.  amihai motro
on the performance of object clustering techniques  we investigate the performance of some of the best-known object clustering algorithms on four different workloads based upon the tektronix benchmark. for all four workloads, stochastic clustering gave the best performance for a variety of performance metrics. since stochastic clustering is computationally expensive, it is interesting that for every workload there was at least one cheaper clustering algorithm that matched or almost matched stochastic clustering. unfortunately, for each workload, the algorithm that approximated stochastic clustering was different. our experiments also demonstrated that even when the workload and object graph are fixed, the choice of the clustering algorithm depends upon the goals of the system. for example, if the goal is to perform well on traversals of small portions of the database starting with a cold cache, the important metric is the per-traversal expansion factor, and a well- chosen placement tree will be nearly optimal; if the goal is to achieve a high steady-state performance with a reasonably large cache, the appropriate metric is the number of pages to which the clustering algorithm maps the active portion of the database. for this metric, the prp clustering algorithm, which only uses access probabilities achieves nearly optimal performance.  manolis m. tsangaris jeffrey f. naughton
viewing meeting captured by an omni-directional camera  one vision of future technology is the ability to easily and inexpensively capture any group meeting that occurs, store it, and make it available for people to view anytime and anywhere on the network. one barrier to achieving this vision has been the design of low-cost camera systems that can capture important aspects of the meeting without needing a human camera operator. a promising solution that has emerged recently is omni-directional cameras that can capture a 360-degree video of the entire meeting.  the panoramic capability provided by these cameras raises both new opportunities and new issues for the interfaces provided for post-meeting viewers --- for example, do we show all meeting participants all the time or do we just show the person who is speaking, how much control do we provide to the end-user in selecting the view, and will providing this control distract them from their task. these are not just user interface issues, they also raise tradeoffs for the client- server systems used to deliver such content. they impact how much data needs to be stored on the disk, what computation can be done on the server vs. the client, and how much bandwidth is needed. we report on a rototype system built using an omni-directional camera and results from user studies of interface preferences expressed by viewers.  yong rui anoop gupta j. j. cadiz
incremental clustering for dynamic information processing  clustering of very large document databases is useful for both searching and browsing. the periodic updating of clusters is required due to the dynamic nature of databases. an algorithm for incremental clustering is introduced. the complexity and cost analysis of the algorithm together with an investigation of its expected behavior are presented. through empirical testing it is shown that the algorithm achieves cost effectiveness and generates statistically valid clusters that are compatible with those of reclustering. the experimental evidence shows that the algorithm creates an effective and efficient retrieval environment.  fazli can
keystroke level analysis of email message organization  organization of email messages takes an increasing amount of time for many email users. research has demonstrated that users develop very different strategies to handle this organization. in this paper, the relationship between the different organization strategies and the time necessary to use a certain strategy is illustrated by a mathematical model based on keystroke- level analysis. the model estimates time usage for archiving and retrieving email messages for individual users. besides explaining why users develop different strategies to organize email messages, the model can also be used to advise users individually when to start using folders, clean messages, learn the search functionality, and using filters to store messages. similar models could assist evaluation of different interface designs where the number of items increase with time.  olle bälter
imprecise schema: a rationale for relations with embedded subrelations  exceptional conditions are anomalous data which meet the intent of a schema but not the schema definition, represent a small proportion of the database extension, and may become known only after the schema is in use. admission of exceptional conditions is argued to suggest a representation that locally stretches the schema definition by use of relations with embedded subrelations. attempted normalization of these relations to 1nf does not yield the static schema typically associated with such transformations. a class of relations, termed exceptional condition nested form (ecnf), is defined which allows the necessary representation of exceptional conditions while containing sufficient restrictions to prevent arbitrary and chaotic inclusion of embedded subrelations. queries on a subset of exceptional conditions, the exceptional constraints, are provided an interpretation via an algorithm that transforms ecnf relations into 1nf relations containing two types of null values. extensions of relational algebraic operators, suitable for interactive query navigation, are defined for use with ecnf relations containing all forms of exceptional conditions.  howard m. dreizen shi-kuo chang
microsoft terraserver: a spatial data warehouse  microsoft® terraserver stores aerial, satellite, and topographic images of the earth in a sql database available via the internet. it is the world's largest online atlas, combining eight terabytes of image data from the united states geological survey (usgs) and spin-2. internet browsers provide intuitive spatial and text interfaces to the data. users need no special hardware, software, or knowledge to locate and browse imagery. this paper describes how terabytes of "internet unfriendly" geo-spatial images were scrubbed and edited into hundreds of millions of "internet friendly" image tiles and loaded into a sql data warehouse. all meta-data and imagery are stored in the sql database.  terraserver demonstrates that general-purpose relational database technology can manage large scale image repositories, and shows that web browsers can be a good geo-spatial image presentation system.  tom barclay jim gray don slutz
control: continuous output and navigation technology with refinement on-line  the control project at u.c. berkeley has developed technologies to provide online behavior for data-intensive applications. using new query processing algorithms, these technologies continuously improve estimates and confidence statistics. in addition, they react to user feedback, thereby giving the user control over the behavior of long-running operations. this demonstration displays the modifications to a database system and the resulting impact on aggregation queries, data visualization, and gui widgets. we then compare this interactive behavior to batch-processing alternatives.  ron avnur joseph m. hellerstein bruce lo chris olston bhaskaran raman vijayshankar raman tali roth kirk wylie
neighborhood systems and relational databases  queries in database can be classified roughly into two types: specific targets and fuzzy targets. many queries are in effect fuzzy targets, however, because of lacking the supports, the user has been emulating them with specific targets by retiring a query repeatedly with minor changes. in this paper, we augment the relational database, with neighborhood systems, so the database can answer a fuzzy query. there have been many works to combine relational databases and fuzzy theory. bucklles and petry replaced attributes values by sets of values. zemankova- leech, kandel, and zviell used fuzzy logic. the formalism of present work is quite general, it allows numerical or nonnumerical measurements of fuzziness in relational databases. the fuzzy theory present here is quite different from the usual theory. our basic assumption here is that: the data are not fuzzy, the queries are.  motro [motr86] introduced the notion of distance into the relational databases. from that he can, then, define the notion of "close-ness" and develop goal queries. though "distance" is a useful concept, yet very often the quantification of it is meaningless or extremely difficult. for example, "very close", "very far" are meaningful concept of distance, yet there is no practical way to quantity them for all occasions. our approach here is more direct, we define directly the meaning of "very close neighborhood". using the concept of neighborhoods is not very original, in fact, in the theory of topological spaces [dugu66], mathematician has been using the "neighborhood system" to study the phenomena of "close-ness". in the territory of fuzzy queries, the notion of "neighborhood" captures the essence of the qualitative information of "close-ness" better than the brute-force- quantified information (distance). a "fuzzy" neighborhood is a qualitative measure of fuzziness.  on the surface, it seems a very complicated procedure to define a neighborhood for each value in the attribute. in fact, if we use the characteristic function (membership function) to define a subset, then the defining procedure is merely another type of distance function (non-measure distance or symbolic distance). now, to define the neighborhood system one can simply re-entered the third column of the relation with linguistic values: "very close", "close", "far". note that there is a "greater than" relation among these linguistic values. in mathematical terms, they forms a lattice [jaco60]. for technical reason, we require the values in third column be elements of a lattice. note that real number is a lattice, so we get motro's results back.  t. y. lin
the logical data model  we propose an object-oriented data model that generalizes the relational, hierarchical, and network models. a database scheme in this model is a directed graph, whose leaves represent data and whose internal nodes represent connections among the data. instances are constructed from objects, which have separate names and values. we define a logic for the model, and describe a nonprocedural query language that is based on the logic. we also describe an algebraic query language and show that it is equivalent to the logical language.  gabriel m. kuper moshe y. vardi
a locking protocol for resource coordination in distributed databases  a locking protocol to coordinate access to a distributed database and to maintain system consistency throughout normal and abnormal conditions is presented. the proposed protocol is robust in the face of crashes of any participating site, as well as communication failures. recovery from any number of failures during normal operation or any of the recovery stages is supported. recovery is done in such a way that maximum forward progress is achieved by the recovery procedures. integration of virtually any locking discipline including predicate lock methods is permitted by this protocol. the locking algorithm operates, and operates correctly, when the network is partitioned, either intentionally or by failure of communication lines. each partition is able to continue with work local to it, and operation merges gracefully when the partitions are reconnected.  a subroutine of the protocol, that assures reliable communication among sites, is shown to have better performance than two-phase commit methods. for many topologies of interest, the delay introduced by the overall protocol is not a direct function of the size of the network. the communications cost is shown to grow in a relatively slow, linear fashion with the number of sites participating in the transaction. an informal proof of the correctness of the algorithm is also presented in this paper.  the algorithm has as its core a centralized locking protocol with distributed recovery procedures. a centralized controller with local appendages at each site coordinates all resource control, with requests initiated by application programs at any site. however, no site experiences undue load. recovery is broken down into three disjoint mechanisms: for single node recovery, merge of partitions, and reconstruction of the centralized controller and tables. the disjointness of the mechanisms contributes to comprehensibility and ease of proof.  the paper concludes with a proposal for an extension aimed at optimizing operation of the algorithm to adapt to highly skewed distributions of activity. the extension applies nicely to interconnected computer networks.  daniel a. menasce gerald j. popek richard r. muntz
partial-match retrieval using hashing and descriptors  this paper studies a partial-match retrieval scheme based on hash functions and descriptors. the emphasis is placed on showing how the use of a descriptor file can improve the performance of the scheme. records in the file are given addresses according to hash functions for each field in the record. furthermore, each page of the file has associated with it a descriptor, which is a fixed-length bit string, determined by the records actually present in the page. before a page is accessed to see if it contains records in the answer to a query, the descriptor for the page is checked. this check may show that no relevant records are on the page and, hence, that the page does not have to be accessed. the method is shown to have a very substantial performance advantage over pure hashing schemes, when some fields in the records have large key spaces. a mathematical model of the scheme, plus an algorithm for optimizing performance, is given.  k. ramamohanarao james a. thom john w. lloyd
data modeling of time-based media  many aspects of time-based media--- complex data encoding, compression, "quality factors," timing---appear problematic from a data modeling standpoint. this paper proposes timed streams as the basic abstraction for modeling time-based media. several media-independent structuring mechanisms are introduced and a data model is presented which, rather than leaving the interpretation of multimedia data to applications, addresses the complex organization and relationships present in multimedia.  simon gibbs christian breiteneder dennis tsichritzis
integrating automatic genre analysis into digital libraries  with the number and types of documents in digital library systems incr easing, tools for automatically organizing and presenting the content have to be found. while many approaches focus on topic-based organization and structuring, hardly any system incorporates automatic structural analysis and representation. yet, genre information (unconsciously) forms one of the most distinguishing features in conventional libraries and in information searches. in this paper we present an approach to automatically analyze the structure of documents and to integrate this information into an automatically created content-based organization. in the resulting visualization, documents on similar topics, yet representing different genres, are depicted as books in differing colors. this representation supports users intuitively in locating relevant information presented in a relevant form.  andreas rauber alexander muller-kogler
the mlpq/gis constraint database system  mlpq/gis [4,6] is a constraint database [5] system like ccube [1] and dedale [3] but with a special emphases on spatio-temporal data. features include data entry tools (first four icons in fig. 1), icon-based queries such as @@@@ intersection, @@@@ union, @@@@ area, @@@@ buffer, @@@@ max and @@@@ min, which optimize linear objective functions, and @@@@ for datalog queries. for example, in fig. 1 we loaded and displayed a constraint database that represents the midwest united states and loaded two contraint relations describing the movements of two persons. the query icon opened a dialog box into which we entered the query which finds (t, i) pairs such that the two people are in the same state i at the same time t.  mlpq/gis can animate [2] spatio-temporal objects that are linear constraint relations over and t.  users can also display in discrete color zones (isometric maps) any spatially distributed variable z that is a linear function and for example, fig. 2 shows the mean annual air temperature nebraska. animation and isometric map display can be combined.  peter revesz rui chen pradip kanjamala yiming li yuguo liu yonghui wang
is information system a science? an inquiry into the nature of the information systems discipline the information systems (is) discipline is apparently undergoing an identity crisis. academicians question the need for is departments in colleges, stating the absence of a core for the field and its integration within other business functions as a basis for its elimination. at the same time, many practitioners, as reflected in the u.s. government's recent it labor shortage report, continue to ignore is as a distinct field of study. this article briefly outlines these and other challenges and argues that notwithstanding underlying philosophical differences, it can be concluded that is is an emerging scientific discipline. this conclusion is reached through an assessment of the debate surrounding the issue of whether is should be a discipline and an analysis of the is discipline using some key characteristics of "science." the arguments put forth in this paper have four key implications for the is community: a continuing emphasis on adopting scientific principles and practices for conducting inquiry into is phenomena; an enhancement of the self-concept of is academics and professionals through a common identity; it enhances the ability of supporters of the is field to defend against criticisms, integration with other disciplines, and resource rivalry; and it creates the potential of being well-situated to building a cumulative tradition in the field. deepak khazanchi bjørn erik munkvold
image mining in iris: integrated retinal information system  there is an increasing demand for systems that can automatically analyze images and extract semantically meaningful information. iris, an integrated retinal information system, has been developed to provide medical professionals easy and unified access to the screening, trend and progression of diabetic-related eye diseases in a diabetic patient database. this paper shows how mining techniques can be used to accurately extract features in the retinal images. in particular, we apply a classification approach to determine the conditions for tortuousity in retinal blood vessels.  wynne hsu mong li lee kheng guan goh
vertical partitioning algorithms for database design  this paper addresses the vertical partitioning of a set of logical records or a relation into fragments. the rationale behind vertical partitioning is to produce fragments, groups of attribute columns, that "closely match" the requirements of transactions.  vertical partitioning is applied in three contexts: a database stored on devices of a single type, a database stored in different memory levels, and a distributed database. in a two-level memory hierarchy, most transactions should be processed using the fragments in primary memory. in distributed databases, fragment allocation should maximize the amount of local transaction processing.  fragments may be nonoverlapping or overlapping. a two-phase approach for the determination of fragments is proposed; in the first phase, the design is driven by empirical objective functions which do not require specific cost information. the second phase performs cost optimization by incorporating the knowledge of a specific application environment. the algorithms presented in this paper have been implemented, and examples of their actual use are shown.  shamkant navathe stefano ceri gio wiederhold jinglie dou
workshop 1: visual interfaces to digital libraries - its past, present, and future  the design of easy-to-use and informative visual interfaces to digital libraries is an integral part to the advances of digital libraries. a wide range of approaches have been developed from a diverse spectrum of perspectives that focus on users and tasks to be supported, data to be modeled, and the efficiency of algorithms. information visualization aims to exploit the human visual information processing system, especially with non- spatial data (such as documents and images typically found in digital libraries). generally, information visualization examines semantic relationships intrinsic to an abstract information space and how they can be spatially navigated and memorized using similar cognitive processes to those that would apply during interactions with the real world. this workshop promotes the convergence of information visualization and digital libraries. it brings together researchers and practitioners in the areas of information visualization, digital libraries, human-computer interaction, library and information science, and computer science to identify the most important issues in the past and the present, and what should be done in the future.  katy börner chaomei chen