Heegaard Floer homology and alternating knots

In an earlier paper, we introduced a knot invariant for a null-homologous knot K in an oriented three-manifold Y, which is closely related to the Heegaard Floer homology of Y. In this paper we investigate some properties of these knot homology groups for knots in the three-sphere. We give a combinatorial description for the generators of the chain complex and their gradings. With the help of this description, we determine the knot homology for alternating knots, showing that in this special case, it depends only on the signature and the Alexander polynomial of the knot (generalizing a result of Rasmussen for two-bridge knots). Applications include new restrictions on the Alexander polynomial of alternating knots.Comment: Published by Geometry and Topology at http://www.maths.warwick.ac.uk/gt/GTVol7/paper6.abs.htm

ON THE STATE-OF-THE-ART: METHODS FOR EVALUATING THE PERFORMANCE EFFECTS OF INVESTMENTS IN INFORMATION TECHNOLOGY

IT creates impacts at several levels in the firm and often indirectly contributes to firm profitability. The problem IS researchers face is identifying robust methods that give reliable results. This paper reports on state-of-the-art methods in IT value research, reviews eleven major empirical studies and suggests three fundamental classes of considerations for conducting successful IT value research. To illustrate methodological advance, new results are presented from two recently completed IT value studies in financial services and manufacturing. The paper concludes by suggesting untapped theory bases that have the most to offer IT value research.Information Systems Working Papers Serie

AN EVALUATIVE FRAMEWORK FOR RESEARCH ON THE PERFORMANCE EFFECTS OF INFORMATION TECHNOLOGY INVESTMENT

Firms today invest enormous resources in information technology with the hope of gaining significant returns which will impact their performance. A growing body of research into the firm performance effects of IT investment has emerged and is sometimes referred to as IT business value reseakh. The problem researchers face is identifying robust methods to gain insight into how IT business value is created. This paper reports on the state of IT business value research by reviewing thirteen empirical studies. It also proposes a new evaluative framework to identify strengths and weaknesses in this research. The paper concludes with a series of recommendations to improve the quality of future IT business value research

Knot Floer homology and the four-ball genus

We use the knot filtration on the Heegaard Floer complex to define an integer invariant tau(K) for knots. Like the classical signature, this invariant gives a homomorphism from the knot concordance group to Z. As such, it gives lower bounds for the slice genus (and hence also the unknotting number) of a knot; but unlike the signature, tau gives sharp bounds on the four-ball genera of torus knots. As another illustration, we calculate the invariant for several ten-crossing knots.Comment: Published by Geometry and Topology at http://www.maths.warwick.ac.uk/gt/GTVol7/paper17.abs.htm

MEASURING BUSINESS VALUE FOR INVESTMENTS IN POINT-OF-SALE TECHNOLOGY

Information Systems Working Papers Serie

Self-organized Critical Model Of Biological Evolution

A punctuated equilibrium model of biological evolution with relative fitness between different species being the fundamental driving force of evolution is introduced. Mutation is modeled as a fitness updating cellular automaton process where the change in fitness after mutation follows a Gaussian distribution with mean $x>0$ and standard deviation $\sigma$. Scaling behaviors are observed in our numerical simulation, indicating that the model is self-organized critical. Besides, the numerical experiment suggests that models with different $x$ and $\sigma$ belong to the same universality class. PACS numbers: 87.10.+e, 05.40.+jComment: 8 pages in REVTEX 3.0 with 4 figures (Figures available on request by sending e-mail to [email protected]

Sustainability conflicts in the blue economy: planning for offshore aquaculture and offshore wind energy development in Norway

Blue economy developments entail an industrialization of the world’s ocean and coastal areas, placing growing pressures on the marine environment and ecosystems. Moreover, the competition for ocean space and resources increases the likelihood for social conflicts. Marine spatial planning has been presented as a tool that can avoid or mitigate conflicts. However, there is a need for a more thorough analysis of the conflicts linked to the blue economy. The objective of this paper is to analyze characteristics of blue economy conflicts and how they are shaped by the institutional context and sustainability discourses. This study also explores perspectives on conflict management and pathways toward sustainable transformations in marine planning. Empirically, we use two case studies of blue growth industries in Norway: (1) offshore wind energy development and (2) offshore aquaculture development. Through these cases, we take a close look at the established principles and procedures which regulate conflicts. Our study shows how current blue economy conflicts are framed and handled through institutionalized practices of conflict management. Our findings are twofold. First, blue economy conflicts are not easily categorized through common conflict typologies (i.e., user-user, user-environment) but increasingly appear to be sustainability conflicts in which all actors use sustainability as a frame of reference for discussing possible and desirable futures. Second, conflicts are not necessarily a negative social process. In fact, conflicts often uncover unsustainable practices and create potential positive pathways for sustainable transformations.A correction to this article has been made. The file here is the updated version. Notes on the correction found here: https://link.springer.com/article/10.1007/s40152-023-00342-0publishedVersio

Probability as a physical motive

Recent theoretical progress in nonequilibrium thermodynamics, linking the physical principle of Maximum Entropy Production ("MEP") to the information-theoretical "MaxEnt" principle of scientific inference, together with conjectures from theoretical physics that there may be no fundamental causal laws but only probabilities for physical processes, and from evolutionary theory that biological systems expand "the adjacent possible" as rapidly as possible, all lend credence to the proposition that probability should be recognized as a fundamental physical motive. It is further proposed that spatial order and temporal order are two aspects of the same thing, and that this is the essence of the second law of thermodynamics.Comment: Replaced at the request of the publisher. Minor corrections to references and to Equation 1 added