waashk/acm huggingface dataset:
how good is that data in the warehouse? a data warehouse is an analytical database used for decision support. data are copied from production databases, cleaned up, and possibly renormalized (i.e., denormalized for performance or normalized to create correct record structures). if the resulting records are normalized incorrectly or if the users do not understand how the records have been denormalized, then a phenomenon called semantic disintegrity may occur. semantic disintegrity occurs when a user submits a query and receives an answer, but the answer is not the answer to the question they believe that they asked.thus an understanding of normalization is critically important for both database designers and database users. unfortunately, the process of normalization relies on a series of heuristics that, in turn, assume the existence of an innate mental logic in the mind of the database designer or user for understanding data dependencies and their implications. the quality of answers derived from the data warehouse, in turn, relies on the existence of this innate mental logic.in order to determine if this is a reasonable assumption, an empirical test was constructed for the purpose of determining if subjects have an innate mental logic for understanding data dependencies and their implications. john m. artz
integrating object-oriented data modelling with a rule-based programming paradigm  logres is a new project for the development of extended database systems which is based on the integration of the object-oriented data modelling paradigm and of the rule-based approach for the specification of queries and updates.  the data model supports generalization hierarchies and object sharing, the rule-based language extends datalog to support generalized type constructors (sets, multisets, and sequences), rule-based integrity constraints are automatically produced by analyzing schema definitions. modularization is a fundamental feature, as modules encapsulate queries and updates, when modules are applied to a logres database, their side effects can be controlled.  the logres project is a follow-up of the algres project, and takes advantage of the algres programming environment for the development of a fast prototype.  f. cacace s. ceri s. crespi- reghizzi l. tanca r. zicari
the scent of a site: a system for analyzing and predicting information scent, usage, and usability of a web site  designers and researchers of users' interactions with the world wide web need tools that permit the rapid exploration of hypotheses about complex interactions of user goals, user behaviors, and web site designs. we present an architecture and system for the analysis and prediction of user behavior and web site usability. the system integrates research on human information foraging theory, a reference model of information visualization and web data- mining techniques. the system also incorporates new methods of web site visualization (dome tree, usage based layouts), a new predictive modeling technique for web site use (web user flow by information scent, wufis), and new web usability metrics.  ed h. chi peter pirolli james pitkow
implementing ranking strategies using text signatures  signature files provide an efficient access method for text in documents, but retrieval is usually limited to finding documents that contain a specified boolean pattern of words. effective retrieval requires that documents with similar meanings be found through a process of plausible inference. the simplest way of implementing this retrieval process is to rank documents in order of their probability of relevance. in this paper techniques are described for implementing probabilistic ranking strategies with sequential and bit-sliced signature tiles and the limitations of these implementations with regard to their effectiveness are pointed out. a detailed comparison is made between signature-based ranking techniques and ranking using term-based document representatives and inverted files. the comparison shows that term- based representations are at least competitive (in terms of efficiency) with signature files and, in some situations, superior.  w. bruce croft pasquale savino
transaction management for object-oriented systems  recently there has been a lot of interest in object-oriented databases, which appears to be driven by application demands in areas such as cad-cam and software development environments. a number of projects are developing data models for object-oriented databases, but, while data models are obviously necessary, less attention has been paid to the more difficult problems involved in supporting such models reliably. my research aims to extend database transaction processing concepts to the object-oriented world. there is general agreement that traditional transaction processing will not be effective.  i am investigating two ideas for extension: using the semantics of the operations being performed (as opposed to read/write semantics), and taking advantage of multiple layers of abstraction in the application. both ideas lead me towards a per-abstraction transaction management design, which is natural for object-oriented programming languages. i hope that inheritance can be used to prevent applications programmers from having to construct transaction management code for each abstraction.  my goal is to build a distributed object- oriented system that is resilient to failures, appropriately controls concurrency, and provides the illusion of a single global object space to all its users, roughly in the sense of a smalltalk or lisp workspace (i.e., small objects, not large objects). this is in contrast to, for example, building a object-oriented database server, or just a reliable centralized system. in working towards such a system, i will first define what the ideal behavior should be. this is not so obvious as one might think, since multiple user workspaces have not been previously developed, to my knowledge. once i have a conceptual model, i will deal with the performance problems. once begun, conceptual design and performance improvement will be an iterative process. i believe that i will learn more about the real problems by taking this approach, rather than by starting with a server or centralized system design. however, the conceptual model will tend to downplay distribution per se, concentrating on the concurrency problems posed by multiple users in the same logical address space. while this is an ambitious line of research, it should produce a number of valuable and interesting results even if my initial goals are not met.  j. elliot b. moss
a horizontal fragmentation algorithm for the fact relation in a distributed data warehouse  data warehousing is one of the major research topics of appliedside database investigators. most of the work to date has focused on building large centralized systems that are integrated repositories founded on pre-existing systems upon which all corporate-wide data are based. unfortunately, this approach is very expensive and tends to ignore the advantages realized during the past decade in the area of distribution and support for data localization in a geographically dispersed corporate structure. this research investigates building distributed data warehouses with particular emphasis placed on distribution design for the data warehouse environment. the article provides an architectural model for a distributed data warehouse, the formal definition of the relational data model for data warehouse and a methodology for distributed data warehouse design along with a "horizontal" fragmentation algorithm for the fact relation.  amin y. noaman ken barker
whiter (or wither) uims?  the subject of user interface management systems (uims) has been a topic of research and debate for the last several years. the goal of such systems has been to automate the production of user interface software. the problem of building quality user interfaces within available resources is a very important one as the demand for new interactive programs grows. prototype uimss have been built and some software packages are presently being marketed as such. many papers have been published on the topic.  there still, however, remain a number of unanswered questions. is a uims an effective tool for building high quality user interfaces or is the run-time cost of abstracting out the user interface too high? why are there not more uimss available and why are they not more frequently used? is simple programmer productivity alone sufficient motivation for learning and adopting yet another programming tool? what is the difference, if any, between a "user interface toolbox", a windowing system and a uims? what are the differences between a uims and the screen and editor generators found in fourth generation languages? in fact, exactly what is a uims?  in order to discuss these questions and to reassess the state of the uims art, siggraph sponsored a workshop on these issues (proceedings will be published in computer graphics in 1987). the panelists represent four subgroups who have each addressed these problems from different points of view.  dan r. olsen mark green keith a. lantz andrew schulert john l. sibert
schemasql: an extension to sql for multidatabase interoperability we provide a principled extension of sql, called _schemasql_, that offers the capability of uniform manipulation of data and schema in relational multidatabase systems. we develop a precise syntax and semantics of _schemasql_ in a manner that extends traditional sql syntax and semantics, and demonstrate the following. (1) _schemasql_ retains the flavor of sql while supporting querying of both data and schema. (2) it can be used to transform data in a database in a structure substantially different from original database, in which data and schema may be interchanged. (3) it also permits the creation of views whose schema is dynamically dependent on the contents of the input instance. (4) while aggregation in sql is restricted to values occurring in one column at a time, _schemasql_ permits "horizontal" aggregation and even aggregation over more general "blocks" of information. (5) _schemasql_ provides a useful facility for interoperability and data/schema manipulation in relational multidatabase systems. we provide many examples to illustrate our claims. we clearly spell out the formal semantics of _schemasql_ that accounts for all these features. we describe an architecture for the implementation of _schemasql_ and develop implementation algorithms based on available database technology that allows for powerful integration of sql based relational dbms. we also discuss the applicability of _schemasql_ for handling semantic heterogeneity arising in a multidatabase system. laks v. s. lakshmanan fereidoon sadri subbu n. subramanian
nonparametric methods for automatic classification of documents and transactions (abstract)  the question of how to classify documents is a central problem in document retrieval. the classification problem can be stated as follows. there exists a large document collection, each of which contains a set of terms. how should the documents be clustered to allow the selection of index terms so that the collection can be searched to the maximal collective benefit of the retrieval system customers? traditionally, transaction functionalities are manually scheduled into deferred and immediate queues for processing without any special consideration given to the interwoven functionalities invoked by the different user groups. the question of how to classify transactions for the concurrency controller in a distributed system is a major problem in transaction scheduling. the problem here is, how should transaction functionalities be scheduled for processing to satisfy the requirements of the different user groups? that is, how should transaction functionalities be organized on disk to minimize disk access time, in the hope of fulfilling the requirements of individual user groups?  this paper presents nonparametric algorithms and heuristic for automatic classification of documents according to the similarity in their keywords; the words likely to be useful as index terms for document set. the normal approximation to the binomial distribution was explored as an index for automatic classification of documents and transactions. a nonparametric measure of association consistent with the cramer statistic was used in the examination of similarities among documents. a nonparametric analysis of variance procedure was developed for comparing the profiles of term frequencies between documents or transaction functionalities invoked between users. the usefulness of the heuristic in the automatic classification of user groups according to the transaction functionalities that they invoke in a distributed system is discussed.  amos o. olagunju
graphical user interfaces and ease of use: some myths examined  graphical user interfaces (guis) are on their way to becoming the most pervasive interface for desktop systems at least partly because of conventional wisdom about their ease of use. such an assumption may have been kindled by vendors' claims about the inherent usability of such interfaces although previous research on the productivity gains from guis has yielded mixed results. this paper reports the results of a field study of 230 users of a popular gui, microsoft corporation's windows. the study examined windows' ease of use---an important factor contributing to eventual productivity. the results indicate that contrary to popular belief guis are not universally easy to use---certain types of individuals are likely to find them easier to use than others. organizational roles and management initiatives can also influence perceptions of ease of use. the findings also suggest that ease of use is enhanced through opportunities for self training rather than traditional, formal training.  michael c. zanino ritu agarwal jayesh prasad
experiments with query acquisition and use in document retrieval systems  in some recent experimental document retrieval systems, emphasis has been placed on the acquisition of a detailed model of the information need through interaction with the user. it has been argued that these "enhanced" queries, in combination with relevance feedback, will improve retrieval performance. in this paper, we describe a study with the aim of evaluating how easily enhanced queries can be acquired from users and how effectively this additional knowledge can be used in retrieval. the results indicate that significant effectiveness benefits can be obtained through the acquisition of domain concepts related to query concepts, together with their level of importance to the information need.  w. b. croft r. das
achieving robustness in distributed database systems  the problem of concurrency control in distributed database systems in which site and communication link failures may occur is considered. the possible range of failures is not restricted; in particular, failures may induce an arbitrary network partitioning. it is desirable to attain a high "level of robustness" in such a system; that is, these failures should have only a small impact on system operation.  a level of robustness termed maximal partial operability is identified. under our models of concurrency control and robustness, this robustness level is the highest level attainable without significantly degrading performance.  a basis for the implementation of maximal partial operability is presented. to illustrate its use, it is applied to a distributed locking concurrency control method and to a method that utilizes timestamps. when no failures are present, the robustness modifications for these methods induce no significant additional overhead.  derek l. eager kenneth c. sevcik
data mining techniques to improve forecast accuracy in airline business predictive models developed by applying data mining techniques are used to improve forecasting accuracy in the airline business. in order to maximize the revenue on a flight, the number of seats available for sale is typically higher than the physical seat capacity (overbooking). to optimize the overbooking rate, an accurate estimation of the number of no-show passengers (passengers who hold a valid booking but do not appear at the gate to board for the flight) is essential. currently, no-shows on future flights are estimated from the number of no-shows on historical flights averaged on booking class level. in this work, classification trees and logistic regression models are applied to estimate the probability that an individual passenger turns out to be a no-show. passenger information stored in the reservation system of the airline is either directly used as explanatory variable or used to create attributes that have an impact on the probability of a passenger to be a no-show. the total number of no-shows in each booking class or on the total flight is then obtained by accumulating the individual no-show probabilities over the entity of interest. we show that this forecasting approach is more accurate than the currently used method. in addition, the selected models lead to a deepened insight into passenger behavior. christoph hueglin francesco vannotti
data visualization sliders  computer sliders are a generic user input mechanism for specifying a numeric value from a range. for data visualization, the effectiveness of sliders may be increased by using the space inside the slider as  • an interactive color scale,  • a barplot for discrete data, and  • a density plot for continuous data.  the idea is to show the selected values in relation to the data and its distribution. furthermore, the selection mechanism may be generalized using a painting metaphor to specify arbitrary, disconnected intervals while maintaining an intuitive user-interface.  stephen g. eick
intelligent help in a one-shot dialog: a protocol study  a database of 150 interactions conducted via electronic mail was analyzed. the database had been constructed as an on-line tool for users and advisors, but the interactions can also be regarded as modelling intelligent help dialog in which posing a query and providing a response are each accomplished in "one- shot". the types of questions users ask and the advisory strategies employed for imcomplete queries without follow-up questioning are described. the goal is to understand this new on-line tool for advising and its implications as a model of one-shot intelligent help dialogs.  amy aaronson john m. carroll
preservation of local sound periodicity with variable-rate video  a method of allowing pitch preservation of sound with variable-rate video playback is suggested. this is an important factor in monitoring of audio content for cueing purposes. methods of separately considering a signal's frequency and time representations are considered with a view to performing time-scale modification with preservation of local periodicity (pitch). particular emphasis is placed upon granulation in time of a sampled source --- a technique based upon dennis gabor's landmark papers in 1946 and 1947 and developed in the field of computer music. this relatively simple method requires no prior signal analysis and is therefore a less computationally expensive method of achieving the goals stated above. this is an important point considering the need for real-time implementation. the process does however introduce some distortion, and investigation into how this may be minimised is necessary to produce acceptable results.  d. knox t. itagaki i. stewart a. nesbitt i. j. kemp
adaptive commitment for distributed real-time transactions  distributed real-time transaction systems are useful for both real- time and high-performance database applications. standard transaction management approaches that use the two-phase commit protocol suffer from its high costs and blocking behavior which is problematic in real-time computing environments. our approach in this paper is to identify ways in which a commit protocol can be made adaptive in the sense that under situations that demand it, such as a transient local overload, the system can dynamically change to a different commitment strategy. the decision to do so can be taken autonomously at any site. the different commitment strategies exploit a trade-off between the cost of commitment and the obtained degree of atomicity. our protocols are based on optimistic commitment strategies, and they rely on local compensatory actions to recover from non-atomic executions. we provide the necessary framework to study the logical and temporal correctness criteria, and we describe examples to illustrate the use of our strategies.  nandit soparkar eliezer levy henry f. korth avi silberschatz
the concurrency control problem in multidatabases: characteristics and solutions  a multidatabase system (mdbs) is a collection of local database management systems, each of which may follow a different concurrency control protocol. this heterogeneity makes the task of ensuring global serializability in an mdbs environment difficult. in this paper, we reduce the problem of ensuring global serializability to the problem of ensuring serializability in a centralized database system. we identify characteristics of the concurrency control problem in an mdbs environment, and additional requirements on concurrency control schemes for ensuring global serializability. we then develop a range of concurrency control schemes that ensure global serializability in an mdbs environment, and at the same time meet the requirements. finally, we study the tradeoffs between the complexities of the various schemes and the degree of concurrency provided by each of them.  sharad mehrotra rajeev rastogi yuri breitbart henry f. korth avi silberschatz
collaborative filtering and the generalized vector space model (poster session)  collaborative filtering is a technique for recommending documents to users based on how similar their tastes are to other users. if two users tend to agree on what they like, the system will recommend the same documents to them. the generalized vector space model of information retrieval represents a document by a vector of its similarities to all other documents. the process of collaborative filtering is nearly identical to the process of retrieval using gvsm in a matrix of user ratings. using this observation, a model for filtering collaboratively using document content is possible.  ian soboroff charles nicholas
olympic records for data at the 1998 nagano games  the 1998 nagano olympic games had more intensive demands on data management than any previous olympics in history. this talk will take you behind the scenes to talk about the technical challenges and the architectures that made it possible to handle 4.5 terabytes of data and sustain a total of almost 650 million web requests, reaching a peak of over 103k per minute. we will discuss the overall structure of the most comprehensive and heavily used internet technology application in history. many products were involved, both hardware and software, but this talk will focus in on the database and web challenges, the technology that made it possible to support this tremendous workload. high availability, data integrity, high performance, support of both smps and clustered architectures were among the features and functions that were critical. we will cover the olympic results system, the commentator information system, info '98, games management, and the olympic web site that made this information available to the internet community. the speaker will be ed lassettre, ibm fellow, and a key member of ibm's olympic team.  edwin r. lassettre