waashk/acm huggingface dataset:
on the design of a learning crawler for topical resource discovery in recent years, the world wide web has shown enormous growth in size. vast repositories of information are available on practically every possible topic. in such cases, it is valuable to perform topical resource discovery effectively. consequently, several new ideas have been proposed in recent years; among them a key technique is focused crawling which is able to crawl particular topical portions of the world wide web quickly, without having to explore all web pages. in this paper, we propose the novel concept of intelligent crawling which actually _learns_ characteristics of the linkage structure of the world wide web while performing the crawling. specifically, the intelligent crawler uses the inlinking web page content, candidate url structure, or other behaviors of the inlinking web pages or siblings in order to estimate the probability that a candidate is useful for a given crawl. this is a much more general framework than the focused crawling technique which is based on a pre- defined understanding of the topical structure of the web. the techniques discussed in this paper are applicable for crawling web pages which satisfy arbitrary user-defined predicates such as topical queries, keyword queries, or any combinations of the above. unlike focused crawling, it is not necessary to provide representative topical examples, since the crawler can learn its way into the appropriate topic. we refer to this technique as _intelligent crawling_ because of its adaptive nature in adjusting to the web page linkage structure. we discuss how to intelligently select features which are most useful for a given crawl. the learning crawler is capable of reusing the knowledge gained in a given crawl in order to provide more efficient crawling for closely related predicates. charu c. aggarwal fatima al-garawi philip s. yu
a test of task-technology fit theory for group support systems group support systems (gss) provide both promise and puzzlement. experimental studies of different systems over the years have resulted in conflicting findings --- sometimes enhancing group performance, at other times having no effect, and occasionally even resulting in worse performance for gss-supported groups than for traditional groups. researchers have speculated that the mixed results are due to a poor fit of the gss with the group's task. a recent model of task- technology fit has provided a theoretical perspective from which to test this issue. in this paper, a theory of task-technology fit is tested by applying it to a selected set of published gss experiments. key constructs in the theory are operationalized via coding instruments, and the application of the coding scheme provides support for the theory. ilze zigurs bonnie k. buckland james r. connolly e. vance wilson
creating trading networks of digital archives  digital archives can best survive failures if they have made several c opies of their collections at remote sites. in this paper, we discuss how autonomous sites can cooperate to provide preservation by trading data. we examine the decisions that an archive must make when forming trading networks, such as the amount of storage space to provide and the best number of partner sites. we also deal with the fact that some sites may be more reliable than others. experimental results from a data trading simulator illustrate which policies are most reliable. our techniques focus on preserving the ``bits'' of digital collections; other services that focus on other archiving concerns (such as preserving meaningful metadata) can be built on top of the system we describe here.  brian cooper hector garcia
using local optimality criteria for efficient information retrieval with redundant information filters  we consider information retrieval when the data---for instance, multimedia--- is computationally expensive to fetch. our approach uses "information filters" to considerably narrow the universe of possibilities before retrieval. we are especially interested in redundant information filters that save time over more general but more costly filters. efficient retrieval requires that decisions must be made about the necessity, order, and concurrent processing of proposed filters (an "execution plan"). we develop simple polynomial-time local criteria for optimal execution plans and show that most forms of concurrency are suboptimal with information filters. although the general problem of finding an optimal execution plan is likely to be exponential in the number of filters, we show experimentally that our local optimality criteria, used in a polynomial-time algorithm, nearly always find the global optimum with 15 filters or less, a sufficient number of filters for most applications. our methods require no special hardware and avoid the high processor idleness that is characteristic of massive-parallelism solutions to this problem. we apply our ideas to an important application, information retrieval of captioned data using natural-language understanding, a problem for which the natural-language processing can be the bottleneck if not implemented well.  neil c. rowe
applying database visualization to the world wide web  in this paper, we present visualizations of parts of the network of documents comprising the world wide web. we describe how we are using the hy+ visualization system to visualize the portion of the world wide web explored during a browsing session. as the user browses, the web browser communicates the url and title of each document fetched as well as all the anchors contained in the document. hy+ displays graphically the history of the navigation and multiple views of the structure of that portion of the web.  masum z. hasan alberto o. mendelzon dimitra vista
strategies and interfaces  while it is difficult to devise human- computer interfaces which work well, it is even more difficult to determine why a good interface is good. in programming and database query languages, many human factors experiments have been performed. these experiments have led to little hard knowledge about the nature of learning or using computer languages.  the paucity of results suggests that we may be examining the wrong factors; we are looking at syntactic features of the interface when perhaps we should be looking at its cognitive features. one of the cognitive features of an interface language is the strategy employed when the language is used to solve a problem. the relationship of a language to the problem-solving strategies it encourages should be the focus of more human factors experiments.  there are a number of problems associated with determining cognitive strategies. the first has to do with the "thinking-out-loud interview approach. while beginning students can sometimes articulate their thoughts and confusions while solving problems, they tend to internalize strategies as they progress, becoming unaware of some of their more powerful cognitive techniques. learning a computer language, like learning most things, is a progression of "chunkings", each level of which may lead to a different kind of hidden strategy. if we are to discover what strategies a language encourages, we must find a way of monitoring this iceberg-like hierarchy of strategies. error analysis may be the best way. we need to construct cognitive models of language users, predict what kinds of errors would occur if the models were correct, and run experiments to test the predictions.  david w. stemple
modification operations in data base machines: where are they?  advances in technology coupled with the inefficiency of the conventional von- neumann type architecture in handling database systems have motivated the design and implementation of the so called database machines. unfortunately, a majority of the proposed database machines have neglected to address proper procedures for modification operations. this negligence is partially due to the complexity of the operations and low performance of the database architectures in handling modification operations.  first, the implementation of the modification operations in some database machines is overviewed. second, we will address the mechanisms in which the relational database machine aslm handles the modification operations. finally, our approach is compared against the other proposed approaches in the literature.  a. r. hurson l. l. miller
a user-friendly algorithm  the interface between a person and a computer can be looked at from either side. programmers tend to view it from the inside; they consider it their job to defend the machine against errors made by its users. from the outside, the user sees his/her problems as paramount. he/she is often at odds with this complex, inflexible, albeit powerful tool. the needs of both people and machines can be reconciled; users will respond more efficiently and intelligently if they receive meaningful feedback. a "user-friendly" algorithm that covers a wide range of interactive environments and is typical of most operating systems and many application programs is presented.  barry dwyer
the active database management system manifesto: a rulebase of adbms features  active database systems have been a hot research topic for quite some years now. however, while "active functionality" has been claimed for many systems, and notions such as "active objects" or "events" are used in many research areas (even beyond database technology), it is not yet clear which functionality a database management system must support in order to be legitimately considered as an active system. in this paper, we attempt to clarify the notion of "active database management system" as well as the functionality it has to support. we thereby distinguish mandatory features that are needed to qualify as an active database system, and desired features which are nice to have. finally, we perform a classification of applications of active database systems and identify the requirements for an active database management system in order to be applicable in these application areas.  corporate act-net consortium
principles of delay-sensitive multimedia data storage retrieval  this paper establishes some fundamental principles for the retrieval and storage of delay-sensitive multimedia data. delay-sensitive data include digital audio, animations, and video. retrieval of these data types from secondary storage has to satisfy certain time constraints in order to be acceptable to the user. the presentation is based on digital audio in order to provide intuition to the reader, although the results are applicable to all delay-sensitive data. a theoretical framework is developed for the real-time requirements of digital audio playback. we show how to describe these requirements in terms of the consumption rate of the audio data and the nature of the data-retrieval rate from secondary storage. making use of this framework, bounds are derived for buffer space requirements for certain common retrieval scenarios. storage placement strategies for multichannel synchronized data are then categorized and examined. the results presented in this paper are basic to any playback of delay-sensitive data and should assist the multimedia system designer in estimating hardware requirements and in evaluating possible design choices.  jim gemmell stavros christodoulakis
self maintenance of multiple views in data warehousing  materialized views (mv) at the data warehouse (dw) can be kept up to date in response to changes in data sources without accessing data sources for additional information. this process is usually refered to as "self maintenance of views". a number of algorithms have been proposed for self maintenance of views, which use auxiliary views (av) to keep some additional information in dw. in this paper we propose an algorithm for self maintainability of multiple mvs using the above approach. our algorithm generates a simple maintenance query to incrementally maintain an mv along with its av at dw. the algorithm maintains these views by minimizing the number and the size of the avs. our approach provides better insight into view maintenance issues by exploiting the dependencies and constraints that might exist in the data sources and multiple mvs at dw.  s. samtani v. kumar m. mohania
some recommendations for designing effective dss (abstract only)  choosing the proper hardware and software tools is only one phase of implementing and managing decision support systems. generally, organizations pass through three phases in adopting dss. the first phase is concerned with learning and experimenting with the system. in the second phase management assesses the benefits and rewards of end-user computing. in the third phase management tries to regain the control which was loosened because of the unrestrained growth of dss. many organizations put great emphasis on the first and third phases of the dss and do not put much attention to the second phase which is concerned with gaining value from the dss systems. to optimize the benefits of dss, management must develop a well-balanced approach that ensures both control of the system and getting rewards from the system. decision support systems must be the mind-support for management to identify the high- impact areas within the organization which lead to the development of a well- balanced approach. this paper presents some recommendations for designing such dss systems.  asad khailany wafa khorshid
a logical design methodology for relational databases using the extended entity-relationship model  a database design methodology is defined for the design of large relational databases. first, the data requirements are conceptualized using an extended entity-relationship model, with the extensions being additional semantics such as ternary relationships, optional relationships, and the generalization abstraction. the extended entity- relationship model is then decomposed according to a set of basic entity- relationship constructs, and these are transformed into candidate relations. a set of basic transformations has been developed for the three types of relations: entity relations, extended entity relations, and relationship relations. candidate relations are further analyzed and modified to attain the highest degree of normalization desired.  the methodology produces database designs that are not only accurate representations of reality, but flexible enough to accommodate future processing requirements. it also reduces the number of data dependencies that must be analyzed, using the extended er model conceptualization, and maintains data integrity through normalization. this approach can be implemented manually or in a simple software package as long as a "good" solution is acceptable and absolute optimality is not required.  toby j. teorey dongqing yang james p. fry
communication control in computer supported cooperative work systems  this paper presents alphadeltaphi-groups (adp-group) as a communication tool for connection level management in distributed cscw systems. in order to accurately model cscw communication patterns, an adp- group is a related set of cooperating processes whose communication is supported by allowing a spectrum of quality-of-service, message delivery reliability, atomicity and causal ordering options to co-exist within the same group. adp-group communication provides appropriate connection management support and network control within distributed cscw environments characterized by a heterogeneous mixture of equipment types, network performance and user activity levels. this efficiency is achieved by defining a small set of canonical group communication operations, by automatically making appropriate connections between data sources and sinks, and by using a receiver-based method of connection specification, monitoring and modification.  robert simon robert sclabassi taieb znati
efficient frequency domain video scrambling for content access control  multimedia data security is very important for multimedia commerce on the internet such as video-on-demand and real-time video multicast. traditional cryptographic algorithms for data security are often not fast enough to process the vast amount of data generated by the multimedia applications to meet the real-time constraints. this paper presents a joint encryption and compression framework in which video data are scrambled efficiently in the frequency domain by employing selective bit scrambling, block shuffling and block rotation of the transform coefficients and motion vectors. the new approach is very simple to implement, yet provides considerable level of security, has minimum adverse impact on the compression efficiency, and allows transparency, transcodability, and other content processing functionalities without accessing the cryptographic key.  wenjun zeng shawmin lei
inter-relational information and incompleteness in relational databases (abstract only)  we augment every relation scheme in the relational data base (rdb) with a special attribute f ( the flag attribute). the values for attribute f may only be non-negative integers. values of f in the set (n:n>1, n is odd) are used for capturing inter-relational disjunctive information. values of f in the set (n:n >1, n is even) are used for capturing intra-relational disjunctive information. tuples of relations with flag value 1 represent information known to be true. tuples of relations with flag value 0 represent information neither known to be true nor known to be false. we shall denote the predicate represented in a relation scheme by the name of the relation scheme. below we show instances p and q of relation schemes p(x,y,f) and q(y,z,f) respectively and logical expressions representing the information contained in them: p(x y f) q(y z f) p(x1,y1) x1 y1 1 y1 z1 0 q(y1,z1) v~q(y1,z1) x2 y2 2 y2 z2 2 q(y2,z2) v q(y3,z3) x3 y3 2 y3 z3 2 p(x2,y2) v p(x3,y3) x4 y4 3 y4 z4 3 p(x4,y4) v q(y4,z4)  under the domain closure assumption [1], a tuple (x1,@@@@) in an instance of the conventional relation scheme r(x,y) represents the disjunction: r(x1,y1) v r(x1,y2) v r(x1,y3) when @@@@ denotes the null value and the domain of attribute y is the set (y1,y2,y3). our scheme thus includes null values as a special case. in addition, our scheme captures many more kinds of incomplete information.  we introduce the notion of an "alternative" under our definition the relation u(a b c f) a1 b1 c1 1 a1 b2 c2 2 a1 b1 c3 2 which contains only intra- relational incomplete information has the following conventional relations as alternatives: u1(a b c) u2(a b c) u3(a b c) a1 b1 c1 a1 b1 c1 a1 b1 c1 a1 b2 c2 a1 b2 c2 a1 b1 c3 a1 b1 c3 also, in our treatment, the following rdb containing inter-relational incomplete information r(a b f) s(b c f) a1 b1 2 b2 c2 3 a2 b2 2 b1 c1 5 a1 b1 3 b1 c1 2 a2 b2 5 b2 c2 2 a3 b3 4 b3 c3 1 a4 b4 4 b4 c4 4 b4 c5 4 has seven alternatives; here each alternative is a pair (ri,si), i lying between 1 and 7 and each of the alternatives contains only intra-relational incompleteness. for this example, the alternatives are as follows: r1= r0 u {(a1,b1,1),(a2,b2,1)} s1= s0 u {(b2,c2,1),(b1,c1,1)} r2= r1, s2= s0 u {(b2,c2,1)} r3=r1, s3= s0 u {(b1,c1,1)} r4= r0 u {(a1,b1,1)}, s4= s1 r5= r4, s5= s3 r6=r0 u {(a2,b2,1)}, s6= s1 r7= r6, s7= s2 where r0 and s0 are as shown below: r0(a b f) s0(b c f) a3 b3 4 b3 c3 1 a4 b4 4 b4 c4 4 b4 c5 4  we also introduce the notion of "minimality" of relation instances and based on the idea of an alternative, we give a specification and realization of an extended join operator; under our treatment, the extended join of r and s above is t, shown below: t(a b c f) a1 b1 c1 2 a2 b2 c2 2 a3 b3 c3 4 a4 b4 c4 4 a4 b4 c5 4  in the context of our scheme, we also introduce an extended closed world assumption, weak functional dependencies and inference rules and conditions for the lossless decomposition of a relation containing incomplete information.  r. b. abhyankar r. l. kashyap
on-line reorganization in object databases  reorganization of objects in an object databases is an important component of several operations like compaction, clustering, and schema evolution. the high availability requirements (24 × 7 operation) of certain application domains requires reorganization to be performed on-line with minimal interference to concurrently executing transactions.  in this paper, we address the problem of on-line reorganization in object databases, where a set of objects have to be migrated from one location to another. specifically, we consider the case where objects in the database may contain physical references to other objects. relocating an object in this case involves finding the set of objects (parents) that refer to it, and modifying the references in each parent. we propose an algorithm called the incremental reorganization algorithm (ira) that achieves the above task with minimal interference to concurrently executing transactions. the ira algorithm holds locks on at most two distinct objects at any point of time. we have implemented ira on brahma, a storage manager developed at iit bombay, and conducted an extensive performance study. our experiments reveal that ira makes on-line reorganization feasible, with very little impact on the response times of concurrently executing transactions and on overall system throughput. we also describe how the ira algorithm can handle system failures.  mohana k. lakhamraju rajeev rastogi s. seshadri s. sudarshan
an evaluation of the augment system  for a period of nine months the author used augment, an electronic office support system. this paper is an evaluation of that system. augment is a commercially available, time-shared system marketed by tymshare. in an integrated manner, augment supports functions needed in any electronic office support system. these functions include word processing, electronic mail, computer conferencing and file sharing. it also supports a powerful and unique method of structuring and viewing a file.  the author was a member of a group of six people who used the system in their daily activities. many of the major functions of augment were regularly used during that period. the author found the system to be extremely supportive in his daily activities and believes that it allowed him to materially increase his productivity. the functions that were supported are reviewed and the strengths and weaknesses of augment as seen by the author are examined.  e. d. callender
equivalence and optimization of relational transactions  a large class of relational database update transactions is investigated with respect to equivalence and optimization. the transactions are straight-line programs with inserts, deletes, and modifications using simple selection conditions. several basic results are obtained. it is shown that transaction equivalence can be decided in polynomial time. a number of optimality criteria for transactions are then proposed, as well as two normal forms. polynomial- time algorithms for transaction optimization and normalization are exhibited. also, an intuitively appealing system of axioms for proving transaction equivalence is introduced. finally, a simple, natural subclass of transactions, called strongly acyclic, is shown to have particularly desirable properties.  serge abiteboul victor vianu