177,279 research outputs found
The dynamics of collaboration networks and the history of general relativity, 1925–1970
No full textThis paper presents a novel methodology for defining and analyzing the dynamics of the collaboration networks of scientists working on general relativity from the mid-1920s–1970. During these four and a half decades the status of the theory underwent a radical transformation: from a marginal theory before the mid-1950s to a pillar of modern physics. To investigate this passage—known as the renaissance of general relativity—we used a definition of collaboration networks broader than the co-authorship relations retrievable from online datasets. We constructed a multilayer network, in which each layer represents a different kind of collaboration. After having analyzed the evolution over time of specific parameters of the co-authorship network, we investigated the effects of adding one type of collaboration edge at a time, in a cumulative fashion, on the values of these parameters and on the topology of the collaboration network through time, including rapid shifts in the dynamic evolution of the largest component. This analysis provides robust quantitative evidence that a shift in the structure of the relativity collaboration network occurred between the late 1950s and the early 1960s, when a giant component started forming. We interpret this shift as the central social dynamic of the renaissance process and then identify its central actors. Our analysis disproves common explanations of the renaissance process. It shows that this phenomenon was not a consequence of astrophysical discoveries in the 1960s, nor was it a simple by-product of socio-economic transformations in the physics landscape after World War II
The Socio-Epistemic Networks of General Relativity, 1925–1970
No full textWe report the results of our analysis of the development of general relativity between 1925 and 1970 based on the conceptual and methodological framework of socio-epistemic networks comprised of three different layers: social, semiotic, and semantic. Our computational approach is used to uncover the mechanism of the passage between the low-water-mark phase of general relativity—roughly from the mid-1920s to the mid-1950s—and the so-called renaissance of the theory after the mid-1950s. Based on this multilayer analysis, we provide substantial empirical evidence that between the second half of the 1950s and the early 1960s there was an evident shift in all three layers. Our analysis disproves common explanations of the renaissance process. It shows that this phenomenon was not a consequence of astrophysical discoveries in the 1960s, nor was it a simple by-product of socio-economic transformations in the physics landscape after World War II. We argue instead that the renaissance has to be understood as a two-phase process both at the social and at the epistemic level. The first occurred between the second half of the 1950s and the early 1960s, when a growing community of physicists redirected their interest toward physical problems in general relativity, while the previous period was characterized by a dispersion of research agendas aimed at substituting the theory with a different and more general one. We call this first phase the theoretical renaissance general relativity. The second phase, which we call the astrophysical turn, was instead an experiment-driven process that started with the discovery of quasars and was characterized by the emergence of relativistic astrophysics and physical cosmology as well as the early phases of gravitational-wave astronomy
The Howey Test Turns 64: Are Courts Grading This Test on a Curve
No full textSixty-four years ago, the Supreme Court decided SEC v. WJ Howey, crafting a definition for one form of security, known as an investment contract. The Supreme Court\u27s definition of investment contract in Howey is flexible, consistent with the Congressional approach to defining the broader concept of what constitutes a security. This choice of adopting a flexible definition for investment contract is not without cost, and raises the specter of inconsistent interpretation and/or application by the lower courts that threatens to undermine the utility of the Howey test itself as a trigger for investor protection. The intentional breadth and adaptability of the definition of investment contract necessarily leads to complex and fact-intensive judicial inquiries in the application thereof and allows for inconsistent results between and among the various courts engaging in such inquiries, creating the possibility of similarly-situated litigants winding up with dissimilar outcomes.
Examples of these disparate outcomes are present in a number of industries, including the viatical settlement industry. Viatical settlements are a form of asset-backed securities under which purchasers buy the right to receive death benefits under life insurance policies from policyholders. These days, the very words asset-backed security may cause the public to recoil in horror, thinking of the sub-prime mortgage debacle and Bernard Madoff being led off in handcuffs while his devastated victims sobbed on the evening news. But not all asset-backed securities are problematic, and when undertaken legally and ethically, these interests can be solid investment vehicles, providing needed liquidity to the capital markets.
As the financial markets continue to grow and innovate, new forms of asset-backed securities will likely be created, and the potential for inconsistent treatment of similarly-situated investors in these asset-backed securities arguably increases, prompting the question explored herein of whether the definition of investment contract in the Howey test is too flexible to further the underlying legislative intent of the federal securities laws to protect investors through mandatory disclosure and anti-fraud liability. At present, investors and issuers have no certainty as to the absolute parameters of the test or how any given court will articulate or interpret the definition of investment contract. The test has been burdened by judicially-imposed nuances, as judges try to give meaning to the Supreme Court\u27s words, and as a consequence, has triggered uneven applications.
This Article challenges the Howey test in light of today\u27s increasingly complicated and volatile securities markets, focusing on whether the underlying legislative goals of the federal securities laws are still met by the Howey test, as currently construed by the courts. The Article provides an overview of the legislative history and current status of the U.S. law on the definition of investment contracts, with a brief examination of the component parts of the Howey test, followed by a discussion of the current regulation of the purchase of insurance policies from insurance policy holders in viatical settlement transactions, as background for the analysis highlighting the shortcomings of the Howey test discussed therein. The Article examines the resale of interests in life insurance policies purchased in viatical settlements, focusing on the inconsistent characterization of viatical settlements by the federal courts, specifically in the D.C. Circuit\u27s decision in SEC v. Life Partners, Inc. and the Eleventh Circuit\u27s decision in SEC v. Mutual Benefits Corp. and offers recommendations to further the underlying goals of the securities laws with respect to investor protection through disclosure and anti-fraud requirements in an effort to honor these goals without sacrificing consistency for the very investors these laws were enacted to protect. The Article ultimately concludes that the benefits of the flexibility of the Howey test outweigh the costs in terms of dissimilar results for similar investments and that the uneven applications of the Howey test by courts should be considered necessary collateral damage, acceptable in light of the significant protections still triggered by the Howey test
The Howey Test Turns 64: Are Courts Grading This Test on a Curve
No full textSixty-four years ago, the Supreme Court decided SEC v. WJ Howey, crafting a definition for one form of security, known as an investment contract. The Supreme Court\u27s definition of investment contract in Howey is flexible, consistent with the Congressional approach to defining the broader concept of what constitutes a security. This choice of adopting a flexible definition for investment contract is not without cost, and raises the specter of inconsistent interpretation and/or application by the lower courts that threatens to undermine the utility of the Howey test itself as a trigger for investor protection. The intentional breadth and adaptability of the definition of investment contract necessarily leads to complex and fact-intensive judicial inquiries in the application thereof and allows for inconsistent results between and among the various courts engaging in such inquiries, creating the possibility of similarly-situated litigants winding up with dissimilar outcomes.
Examples of these disparate outcomes are present in a number of industries, including the viatical settlement industry. Viatical settlements are a form of asset-backed securities under which purchasers buy the right to receive death benefits under life insurance policies from policyholders. These days, the very words asset-backed security may cause the public to recoil in horror, thinking of the sub-prime mortgage debacle and Bernard Madoff being led off in handcuffs while his devastated victims sobbed on the evening news. But not all asset-backed securities are problematic, and when undertaken legally and ethically, these interests can be solid investment vehicles, providing needed liquidity to the capital markets.
As the financial markets continue to grow and innovate, new forms of asset-backed securities will likely be created, and the potential for inconsistent treatment of similarly-situated investors in these asset-backed securities arguably increases, prompting the question explored herein of whether the definition of investment contract in the Howey test is too flexible to further the underlying legislative intent of the federal securities laws to protect investors through mandatory disclosure and anti-fraud liability. At present, investors and issuers have no certainty as to the absolute parameters of the test or how any given court will articulate or interpret the definition of investment contract. The test has been burdened by judicially-imposed nuances, as judges try to give meaning to the Supreme Court\u27s words, and as a consequence, has triggered uneven applications.
This Article challenges the Howey test in light of today\u27s increasingly complicated and volatile securities markets, focusing on whether the underlying legislative goals of the federal securities laws are still met by the Howey test, as currently construed by the courts. The Article provides an overview of the legislative history and current status of the U.S. law on the definition of investment contracts, with a brief examination of the component parts of the Howey test, followed by a discussion of the current regulation of the purchase of insurance policies from insurance policy holders in viatical settlement transactions, as background for the analysis highlighting the shortcomings of the Howey test discussed therein. The Article examines the resale of interests in life insurance policies purchased in viatical settlements, focusing on the inconsistent characterization of viatical settlements by the federal courts, specifically in the D.C. Circuit\u27s decision in SEC v. Life Partners, Inc. and the Eleventh Circuit\u27s decision in SEC v. Mutual Benefits Corp. and offers recommendations to further the underlying goals of the securities laws with respect to investor protection through disclosure and anti-fraud requirements in an effort to honor these goals without sacrificing consistency for the very investors these laws were enacted to protect. The Article ultimately concludes that the benefits of the flexibility of the Howey test outweigh the costs in terms of dissimilar results for similar investments and that the uneven applications of the Howey test by courts should be considered necessary collateral damage, acceptable in light of the significant protections still triggered by the Howey test
The Howey Test Turns 64: Are the Courts Grading this Test on a Curve?
No full textSixty-four years ago, the Supreme Court decided SEC v. W.J. Howey, crafting a definition for one form of security, known as an investment contract. The Supreme Court’s definition of investment contract in Howey is flexible, consistent with the Congressional approach to defining the broader concept of what constitutes a security. This choice of adopting a flexible definition for investment contract is not without cost, and raises the specter of inconsistent interpretation and/or application by the lower courts that threatens to undermine the utility of the Howey test itself as a trigger for investor protection. The intentional breadth and adaptability of the definition of investment contract necessarily leads to complex and factintensive judicial inquiries in the application thereof, and allows for inconsistent results between and among the various courts engaging in such inquiries, creating the possibility of similarly-situated litigants winding up with dissimilar outcomes.
Examples of these disparate outcomes are present in a number of industries, including the viatical settlement industry. Viatical settlements are a form of “asset-backed securities” under which purchasers buy the right to receive death benefits under life insurance policies from policyholders. These days, the very words “asset-backed security” may cause the public to recoil in horror, thinking of the sub-prime mortgage
debacle and Bernard Madoff being led off in handcuffs while his devastated victims sobbed on the evening news. But not all asset-backed securities are problematic, and when undertaken legally and ethically, these interests can be solid investment vehicles, providing needed liquidity to the capital markets.
As the financial markets continue to grow and innovate, new forms of asset-backed securities will likely be created, and the potential for inconsistent treatment of similarly-situated investors in these asset-backed securities arguably increases, prompting the question explored herein of whether the definition of investment contract in the Howey test is too flexible to further the underlying legislative intent of the federal securities laws to protect investors through mandatory disclosure and anti-fraud liability. At present, investors and issuers have no certainty as to the absolute parameters of the test or how any given court will articulate or interpret the definition of investment contract. The test has been burdened by judicially-imposed nuances, as judges try to give meaning to the Supreme Court’s words, and as a consequence, has triggered uneven applications.
This Article challenges the Howey test in light of today’s increasingly complicated and volatile securities markets, focusing on whether the underlying legislative goals of the federal securities laws are still met by the Howey test, as currently construed by the courts. The Article provides an overview of the legislative history and current status of the U.S. law on the definition of investment contracts, with a brief examination of the component parts of the Howey test, followed by a discussion of the current regulation of the purchase of insurance policies from insurance policy holders in viatical settlement transactions, as background for the analysis highlighting the shortcomings of the Howey test discussed therein. The Article examines the resale of interests in life insurance policies purchased in viatical settlements, focusing on the inconsistent characterization of viatical settlements by the federal courts, specifically in the D.C. Circuit’s decision in SEC v. Life Partners, Inc. and the Eleventh Circuit’s decision in SEC v. Mutual Benefits Corp. and offers recommendations to further the underlying goals of the securities laws with respect to investor protection through disclosure and anti-fraud requirements in an effort to honor these goals without sacrificing consistency for the very investors these laws were enacted to protect. The Article ultimately concludes that the benefits of the flexibility of the Howey test outweigh the costs in terms of dissimilar results for similar investments and that the uneven applications of the Howey test by courts should be considered necessary collateral damage, acceptable in light of the significant protections still triggered by the Howey test
Confirmation of the superior performance of the causal Graphical Analysis Using Genetics (cGAUGE) pipeline in comparison to various competing alternatives
No full text\ua9 2022 Howey R and Cordell HJ. Various methods exist that utilise information from genetic predictors to help identify potential causal relationships between measured biological or clinical traits. Here we conduct computer simulations to investigate the performance of a recently proposed causal Graphical Analysis Using Genetics (cGAUGE) pipeline, used as a precursor to Mendelian randomization analysis, in comparison to our previously proposed Bayesian Network approach for addressing this problem. We use the same simulation (and analysis) code as was used by the developers of cGAUGE, adding in a comparison with the Bayesian Network approach. Overall, we find the optimal method (in terms of giving high power and low false discovery rate) is the cGAUGE pipeline followed by subsequent analysis using the MR-PRESSO Mendelian randomization approach
Validating plans with continuous effects
No full textA critical element in the use of PDDL2.1, the modelling language developed for the International Planning Competition series, has been the common understanding of the semantics of the language. The fact that this has been implemented in plan validation software was vital to the progress of the competition. However, the validation of plans using actions with continuous effects presents new challenges (that precede the challenges presented by planning with those effects). In this paper we review the need for continuous effects, their semantics and the problems that arise in validation of plans that include them. We report our progress in implementing the semantics in an extended version of the plan validation software
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Validating plans with exogenous events
No full textWe are concerned with the problem of deciding the validity of a complex plan involving interacting continuous activity.In these situations there is a need to model and reason about the continuous processes and events that arise as a consequence of the behaviour of the physical world in which the plan is expected to execute. In this paper we describe how events, which occur as the outcome of uncontrolled physical processes, can be taken into account in determining whether a plan is valid with respect to the domain model. We do not consider plan generation issues in this paper but focus instead on issues in domain modelling and plan validation
VAL : automatic plan validation, continuous effects and mixed initiative planning using PDDL
No full textThis paper describes aspects of our plan validation tool, VAL. The tool was initially developed to support the 3rd International Planning Competition, but has subsequently been extended in order to exploit its capabilities in plan validation and development. In particular, the tool has been extended to include advanced features of PDDL2.1 which have proved important in mixed-initiative planning in a space operations project. Amongst these features, treatment of continuous effects is the most significant, with important effects on the semantic interpretation of plans. The tool has also been extended to keep abreast of developments in PDDL, providing critical support to participants and organisers of the 4th IPC
- …
