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61.
Gutiérrez G. de Guzmán I. P. Martínez J. Ojeda-Aciego M. Valverde A. 《Studia Logica》2002,72(1):85-112
The tree-based data structure of -tree for propositional formulas is introduced in an improved and optimised form. The -trees allow a compact representation for negation normal forms as well as for a number of reduction strategies in order to consider only those occurrences of literals which are relevant for the satisfiability of the input formula. These reduction strategies are divided into two subsets (meaning- and satisfiability-preserving transformations) and can be used to decrease the size of a negation normal form A at (at most) quadratic cost. The reduction strategies are aimed at decreasing the number of required branchings and, therefore, these strategies allow to limit the size of the search space for the SAT problem. 相似文献
62.
Andersen D;Danish Committee on Scientific Dishonesty 《Science and engineering ethics》2000,6(1):25-34
In 1992, The Danish Medical Research Council established a national committee on scientific dishonesty with the twofold task
of handling cases of scientific misconduct and taking preventive initiatives. Scientific dishonesty was proven in only five
cases, but in another nine cases lesser degrees of deviations from good scientific practice were found. The experiences from
a total of 24 treated cases indicated that three key areas were at the basis of most of the accusations and the deviations
from good practice: uncertainty about 1) authorship, about 2) rights and duties to use scientific data and about 3) agreements
at the initiation of joint studies. As a consequence guidelines on good practice have been issued on these key subjects.
An earlier version of this paper was presented at a symposium, Scientific Misconduct. An International Perspective, organised by The Medical University of Warsaw, 16 November, 1998. 相似文献
63.
The increasing number of companies providing internet services and auction tools helped popularize the online reverse auction
trend for purchasing commodities and services in the last decade. As a result, a number of owners, both public and private,
accepted the online reverse auctions as the bidding technique for their construction projects. Owners, while trying to minimize
their costs for construction projects, are also required to address their ethical responsibilities to the shareholders. In
the case of online reverse auctions for construction projects, the ethical issues involved in the bidding technique directly
reflects on the owner’s ethical and social responsibilities to their shareholders.
The goal of this paper is to identify the shareholder ethics and responsibilities in online reverse auctions for construction
projects by analyzing the ethical issues for the parties involved in the process. The identification of the ethical issues
and responsibilities requires clear definition and understanding of professional ethics and the roles of the involved parties.
In this paper, first, the concept of professional ethics and social responsibility is described in a general form. To illustrate
the ethical issues and responsibilities, a sample case of bidding for a construction project using online reverse auction
techniques is presented in which the shareholders were actively involved in questioning the ethical issues. The issues involved
in the bidding process and their reflection on the shareholder responsibilities are described and analyzed for each stage
of the process. A brief discussion of the overall process is also included to address the general ethical issues involved
in online reverse auctions.
An earlier version of this paper was presented at the “Ethics and Social Responsibility in Engineering and Technology” meeting,
New Orleans, 2003. 相似文献
64.
Tucker3 hierarchical classes analysis 总被引:1,自引:0,他引:1
This paper presents a new model for binary three-way three-mode data, called Tucker3 hierarchical classes model (Tucker3-HICLAS). This new model generalizes Leenen, Van Mechelen, De Boeck, and Rosenberg's (1999) individual differences hierarchical classes model (INDCLAS). Like the INDCLAS model, the Tucker3-HICLAS model includes a hierarchical classification of the elements of each mode, and a linking structure among the three hierarchies. Unlike INDCLAS, Tucker3-HICLAS (a) does not restrict the hierarchical classifications of the three modes to have the same rank, and (b) allows for more complex linking structures among the three hierarchies. An algorithm to fit the Tucker3-HICLAS model is described and evaluated in an extensive simulation study. An application of the model to hostility data is discussed.The first author is a Research Assistant of the Fund for Scientific Research-Flanders (Belgium). The research reported in this paper was partially supported by the Research Council of K.U. Leuven (GOA/2000/02). We are grateful to Kristof Vansteelandt for providing us with an interesting data set. 相似文献
65.
Gardenier JS 《Science and engineering ethics》2003,9(3):425-434
This paper informally summarizes a two-day symposium held at the U.S. National Academy of Sciences in Washington, D.C., September
5–6, 2002. The issue was to what extent the progress of science and societal capacity for continued technological innovation
are threatened by excessive protection of intellectual property. Excessive protection creates disadvantages not only for scientists
and inventors but also for educators/students and for librarians/clientele. Speakers from a variety of disciplines and institutions
agreed unanimously that scientific and technological progress is, indeed, under serious threat. Various opinions were expressed
about the degree of threat, currently and prospectively, as well as what counter-measures are best suited to resist undue
restrictions on creative uses of scientific and technical data and information. This summary is based entirely on the author’s
notes from the symposium, and the commentary offered is his alone. My apologies to the speakers if this paper does not accurately
reflect the primary intent of their presentations. The “Suggested Readings” offered at the end are not specific to the speakers’
statements but rather are offered as a general resource to aid further research. The definitive record of the symposium is
planned to be available from the National Academies Press as a Proceedings publication in the summer of 2003.
John Gardenier is an independent researcher, ethicist and science writer. 相似文献
66.
In this paper, the constrained maximum likelihood estimation of a two-level covariance structure model with unbalanced designs is considered. The two-level model is reformulated as a single-level model by treating the group level latent random vectors as hypothetical missing-data. Then, the popular EM algorithm is extended to obtain the constrained maximum likelihood estimates. For general nonlinear constraints, the multiplier method is used at theM-step to find the constrained minimum of the conditional expectation. An accelerated EM gradient procedure is derived to handle linear constraints. The empirical performance of the proposed EM type algorithms is illustrated by some artifical and real examples.This research was supported by a Hong Kong UCG Earmarked Grant, CUHK 4026/97H. We are greatly indebted to D.E. Morisky and J.A. Stein for the use of their AIDS data in our example. We also thank the Editor, two anonymous reviewers, W.Y. Poon and H.T. Zhu for constructive suggestions and comments in improving the paper. The assistance of Michael K.H. Leung and Esther L.S. Tam is gratefully acknowledged. 相似文献
67.
Psychological distress,help‐seeking,and perceived barriers to psychological treatment among Australian parents
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68.
We used the take‐the‐best heuristic to develop a model to forecast the popular two‐party vote shares in U.S. presidential elections. The model draws upon information about how voters expect the candidates to deal with the most important issue facing the country. We used cross‐validation to calculate a total of 1000 out‐of‐sample forecasts, one for each of the last 100 days of the ten U.S. presidential elections from 1972 to 2008. Ninety‐seven per cent of forecasts correctly predicted the winner of the popular vote. The model forecasts were competitive compared to forecasts from methods that incorporate substantially more information (e.g., econometric models and the Iowa Electronic Markets). The purpose of the model is to provide fast advice on which issues candidates should stress in their campaign. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
69.
The commentary discusses several topics in Dr. Iacobucci's article on mediation analysis with categorical variables including the lack of equivalency of mediated effect measures, ab, and c–c′, that are algebraically equivalent in ordinary least squares regression models. The commentary raises the issue of correlated mediation coefficients and presents formulas to include the correlation in the test of significance. References to new developments in causal mediation analysis for categorical variables are given and the importance of programs of research to establish a mediation theory is emphasized. 相似文献
70.
This paper provides an overview and task analysis for creating a continuous ABC data‐collection application using Xcode on a Mac computer. Behavior analysts can program an ABC data collection system, complete with a customized list of target clients, antecedents, behaviors, and consequences to be recorded, and have the data automatically sent to an e‐mail account after observations have concluded. Further suggestions are provided to customize the ABC data‐ collection system for individual preferences and clinical needs. 相似文献