366 research outputs found

    Biological taxonomy and ontology development: scope and limitations

    Get PDF
    The prospects of integrating full-blown biological taxonomies into an ontological reasoning framework are reviewed. We contrast the common usage of a static 'snapshot' hierarchy in ontological representations of taxonomy with a more realistic situation that involves dynamic, piece-meal revisions of particular taxonomic groups and requires alignment with relevant preceding perspectives. Taxonomic practice is characterized by a range of phenomena that are orthogonal to the logical semantic background from which ontological entities and relationships originate, and therefore pose special challenges to ontological representation and reasoning. Among these phenomena are: (1) the notion that there is a single phylogenetic hierarchy in nature which taxonomy can only gradually approximate; (2) the evolvability of taxa which means that taxon-defining features may be lost in subordinate members or independently gained across multiple sections of the tree of life; (3) the hybrid approach of defining taxa both in reference to properties (intensional) and members (ostensive) which undermines the individual/class dichotomy sustaining conventional ontologies; (4) the idiosyncratic yet inferentially valuable usage of Linnaean ranks; (5) the indelible and semantically complex 250-year legacy of nomenclatural and taxonomic changes that characterizes the current system; (6) the insufficient taxonomic exploration of large portions of the tree of life; and the need to use a sophisticated terminology for aligning taxonomic entities in order to integrate both (7) single and (8) multiple hierarchies. We briefly such how such integration may proceed based on an initial expert alignment of concept relationship and subsequent use of first-order logic algorithms to maximize consistency, reveal implied relationships, and ultimately merge taxonomies.
 In light of the aforementioned obstacles, we suggest that research along the taxonomy/ontology interface should focus on either strictly nomenclatural entities or specialize in ontology-driven methods for producing alignments between multiple taxonomies. We furthermore suggest that the prospects of developing successful ontologies for taxonomy will largely depend on the ability of the taxonomic expert community to present their phylogenies and classifications in a way that is more compatible with ontological reasoning than concurrent practice. Minimally, this means (1) adopting rigorous standards for linking new core taxonomies to relevant peripheral taxonomies through comprehensive alignments so that their ontological/taxonomic connections are transparent; (2) using lineage-specific ontological standards for phenotype-based accounts of taxa while taking into account the phylogenetic contextuality of phenotypic descriptors; (3) presenting all nomenclatural and taxonomic novelties in an explicit, ontology-compatible format, including intensional and ostensive definitions; and (4) offering comprehensive intensional/ostensive alignments to entities in relevant preceding taxonomies

    Perceived entitlement causes discrimination against attractive job candidates in the domain of relatively less desirable jobs

    Get PDF
    People generally hold positive stereotypes of physically attractive people and because of those stereotypes often treat them more favorably. However, we propose that some beliefs about attractive people, specifically, the perception that attractive individuals have a greater sense of entitlement than less attractive individuals, can result in negative treatment of attractive people. We examine this in the context of job selection and propose that for relatively less desirable jobs, attractive candidates will be discriminated against. We argue that the ascribed sense of entitlement to good outcomes leads to perceptions that attractive individuals are more likely to be dissatisfied working in relatively less desirable jobs. When selecting candidates for relatively less desirable jobs, decision makers try to ascertain whether a candidate would be satisfied in those jobs, and the stereotype of attractive individuals feeling entitled to good outcomes makes decision makers judge attractive candidates as more likely to be dissatisfied in relatively less (but not more) desirable jobs. Consequently, attractive candidates are discriminated against in the selection for relatively less desirable jobs. Four experiments found support for this theory. Our results suggest that different discriminatory processes operate when decision makers select among candidates for relatively less desirable jobs and that attractive people might be systematically discriminated against in a segment of the workforce

    Additional studies of quasi-optimum feedback control techniques

    Get PDF
    Quasi-optimal control technique for space vehicle attitude, bounded acceleration rendezvous in free space, and aircraft landing proble

    MOSAIC: Unified Platform for Dynamic Overlay Selection and Composition

    Get PDF
    MOSAIC constructs new overlay networks with desired characteristics by composing existing overlays with subsets of those attributes. Thus, MOSAIC overcomes the problem of multiple network infrastructures that are partial solutions, while preserving deployability. Composition of control and/or data planes is possible in the system. MOSAIC overlays are specified in Mozlog, a declarative language that specifies overlay properties without binding them to a particular implementation or underlying network. This paper focuses on the runtime aspects of MOSAIC: how it enables interoperability between different overlay networks and how it implements switching between different overlay compositions, permitting dynamic compositions with both existing overlay networks and legacy applications. The system is validated experimentally using declarative overlay compositions concisely specified in Mozlog: an indirection overlay that supports mobility (i3), a resilient overlay (RON), and scalable lookups (Chord), all of which are combined to provide new functionality. MOSAIC provides the benefits of runtime composition to simultaneously deliver application-aware mobility, NAT traversal and reliability with low performance overhead, demonstrated by measurements on both a local cluster and PlanetLab

    Negotiation Impasses: Types, Causes, and Resolutions

    Get PDF
    Although impasses are frequently experienced by negotiators, are featured in newspaper articles, and are reflected in online searches and can be costly, negotiation scholarship does not appear to consider them seriously as phenomena worth explaining. A review of negotiation tasks to study impasses reveals that they bias negotiators toward agreement. We systematically organize past findings on impasses and integrate them in the impasse type, cause, and resolution model (ITCR model). Our fundamental assumption is that a positive bargaining zone does not imply symmetric preferences for an agreement. One or both negotiators may prefer an impasse over an agreement despite a positive bargaining zone. We argue that it is beneficial for management research to distinguish between three impasse types: If both negotiators perceive benefit from an impasse, they are wanted; if one negotiator perceives benefits from an impasse, they are forced; and if both do not perceive benefits from the impasse, they are unwanted. We review structural (e.g., bargaining zone, communication channels), interpersonal (e.g., tough tactics, emotions), and intrapersonal (e.g., biases, available information, and framing) factors as the likely antecedents of the three impasse types. We also examine evidence that suggests that wanted impasses can be resolved by changing the negotiation structure for both parties, forced impasses can be resolved through persuasion, and unwanted impasses can be overcome by debiasing both parties. Finally, we review current methodological guidance and provide updated recommendations on how scholars should deal with impasses in both study designs and data analyses

    Multiple Diffractions of Elastic Shear Wawes by a Rigid Rectangular Foundation Embedded in an Elastic Half Space 1

    Get PDF
    A rigid rectangular foundation, embedded in an elasti

    Public Health for the Internet φ Towards A New Grand Challenge for Information Management

    Get PDF
    Business incentives have brought us within a small factor of achieving the database community\u27s Grand Challenge set out in the Asilomar Report of 1998. This paper makes the case for a new, focused Grand Challenge: Public Health for the Internet. The goal of PHI (or φ) is to enable collectives of hosts on the Internet to jointly monitor and promote network health by sharing information on network conditions in a peer-to-peer fashion. We argue that this will be a positive effort for the research community for a variety of reasons, both in terms of its technical reach and its societal impact. This version of the φ vision is targeted at readers in the database research community, but the effort is clearly multidisciplinary. A more generalist version of this paper will be maintained at http://openphi.net

    Unethical for the sake of the group: Risk of social exclusion and pro-group unethical behavior

    Get PDF
    This research tested the idea that the risk of exclusion from one’s group motivates group members to engage in unethical behaviors that secure better outcomes for the group (pro-group unethical behaviors). We theorized that this effect occurs because those at risk of exclusion seek to improve their inclusionary status by engaging in unethical behaviors that benefit the group; we tested this assumption by examining how the effect of exclusion risk on pro-group unethical behavior varies as a function of group members’ need for inclusion. A 2-wave field study conducted among a diverse sample of employees working in groups (Study 1) and a constructive replication using a laboratory experiment (Study 2) provided converging evidence for the theory. Study 1 found that perceived risk of exclusion from one’s workgroup predicted employees’ engagement in pro-group unethical behaviors, but only when employees have a high (not low) need for inclusion. In Study 2, compared to low risk of exclusion from a group, high risk of exclusion led to more pro-group (but not pro-self) unethical behaviors, but only for participants with a high (not low) need for inclusion. We discuss implications for theory and the management of unethical behaviors in organizations

    The Case for a Hybrid P2P Search Infrastructure

    Get PDF
    Popular P2P file-sharing systems like Gnutella and Kazaa use unstructured network designs. These networks typically adopt flooding-based search techniques to locate files. While flooding-based techniques are effective for locating highly replicated items, they are poorly suited for locating rare items. As an alternative, a wide variety of structured P2P networks such as distributed hash tables (DHTs) have been recently proposed. Structured networks can efficiently locate rare items, but they incur significantly higher overheads than unstructured P2P networks for popular files. Through extensive measurements of the Gnutella network from multiple vantage points, we argue for a hybrid search solution, where structured search techniques are used to index and locate rare items, and flooding techniques are used for locating highly replicated content. To illustrate, we present experimental results of a prototype implementation that runs at multiple sites on PlanetLab and participates live on the Gnutella network
    • …
    corecore