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971.
Typically in the United States only one contractor (the developer or first producer) makes a weapon system because it is too expensive or for some other reason infeasible to develop a second source. Congress and higher headquarters are constantly challenging the Armed Services to add other sources who can competitively make their systems. This paper describes a method of analyzing this complex problem which often has very large monetary and other significant impacts. Procedures and a case study are presented which consider cost and other criteria which might be used to make the second source decision. 相似文献
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A treatment model for the developmentally handicapped child does more than meet crisis situations. 相似文献
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The syntenic distance between two genomes is the minimum number of fusions, fissions, and translocations that can transform one genome to the other, ignoring the gene order within chromosomes. As the problem is NP-hard in general, some particular classes of synteny instances, such as linear synteny, exact synteny and nested synteny, are examined in the literature. In this paper, we propose a new special class of synteny instances, called uncovering synteny. We first present a polynomial time algorithm to solve the connected case of uncovering synteny optimally. By performing only intra-component moves, we then solve the unconnected case of uncovering synteny. We will further calculate the diameters of connected and unconnected uncovering synteny, respectively. 相似文献
979.
The use of constructive-developmental theory to advance the understanding of leadership 总被引:1,自引:0,他引:1
Cynthia D. McCauley Wilfred H.Drath Charles J. Palus Patricia M.G. O'Connor Becca A. Baker 《The Leadership Quarterly》2006,17(6):634
Constructive-developmental theory is a stage theory of adult development that focuses on the growth and elaboration of a person's ways of understanding the self and the world. In this article we review how the constructive-developmental frameworks of Kegan [Kegan, R. (1982). The evolving self: Problem and process in human development. Cambridge, MA: Harvard University Press], Torbert [Torbert, W. R. (1987). Managing the corporate dream: Restructuring for long-term success. Homewood, IL: Dow Jones-Irwin.], and Kohlberg [Kohlberg, L. (1969). Stage and sequence: The cognitive developmental approach to socialization. In D. Goslin (Ed.), Handbook of socialization: Theory and research. New York: Rand McNally] have been applied in the theoretical and empirical literature on leadership and management. Although the literature has produced a number of propositions, the notion that a leader's order of development should impact his or her leadership effectiveness or managerial performance has generated the most research. We found mixed support for this proposition as well as a number of limitations in the research in general. To have a greater impact on the leadership field, constructive-developmental theory needs to generate more robust research, to link more clearly with on-going streams of leadership research, and to explore the contribution of aspects of the theory beyond individual order of development. 相似文献
980.
We consider the problem of binary-image restoration. The image being restored is not random, and we make no assumption about the nature of its contents. The estimate of the colour at each site is a fixed (the same for all sites) function of the data available in a neighbourhood of that site. Under this restriction, the estimate minimizing the overall mean squared error of prediction is the conditional expectation of the true colour given the observations in the neighbourhood of a site. The computation of this conditional expectation leads to the formal definition of the local characteristics of an image, namely, the frequency with which each pattern appears in the true unobserved image. When the “true” distribution of the patterns is unknown, it can be estimated from the records. The conditional expectation described above can then be evaluated using the estimated distribution of the patterns, and this procedure leads to a very natural estimate of the colour at each site. We propose two unbiased and consistent estimates for the distribution of patterns when the noise is a Gaussian white noise. Since the size of realistic images is very large, the estimated pattern distribution is usually close to the true one. This suggests that the estimated conditional expectation can be expected to be nearly optimal. An interesting feature of the proposed restoration methods is that they do not require prior knowledge of the local or global properties of the true underlying image. Several examples based on synthetic images show that the new methods perform fairly well for a variety of images with different degrees of colour continuity or textures. 相似文献