Toward an automaton Constraint for Local Search

We explore the idea of using finite automata to implement new constraints for local search (this is already a successful technique in constraint-based global search). We show how it is possible to maintain incrementally the violations of a constraint and its decision variables from an automaton that describes a ground checker for that constraint. We establish the practicality of our approach idea on real-life personnel rostering problems, and show that it is competitive with the approach of [Pralong, 2007]

Time, Tense, & Rationality

In this thesis I try to advance our understanding of the nature of time. In particular I defend the idea that there is an objective difference between the past, the present, and the future; a metaphysical tense. This is in opposition to the idea that these distinctions merely mark an aspect of our perspective on entities in time. I argue that tensed beliefs – beliefs that go hand-in-hand with tensed language – are essential to our lives as rational animals. Firstly, they are essential to our practices of providing reasons for action and acting for reasons. Secondly, they are essential for our lives as emotional animals whose emotions are appropriately responsive to the world. Perry has argued that indexical – including tensed – beliefs are essential for actions. In order to attend my meeting, it is not enough that I know that it is at 2pm, I must also know that it is now 1:55pm. Examining Perry’s argument I show that its proper conclusion is that tensed and first-personal beliefs are necessary for rational actions. I argue that reasons are facts (not belief/desire complexes or intensional entities). Further, the rationality of an action derives solely from these reasons, so that when an agent is not mistaken their action is rational purely insofar as it is done for a reason that justifies it. This means that beliefs are required for rational actions only to the extent that they provide an awareness of reasons and thereby enable an action. A proper understanding of rational action thus enables me to say that if an action must involve one belief rather than another in order to be rational, this must be because the former belief involves an awareness of a reason, hence fact, that the latter does not. Combining this with the proper conclusion of Perry’s argument we can say that tensed beliefs are required in the place of any tenseless beliefs in rational actions, and therefore must involve an awareness of facts that the latter cannot capture. Given that our actions are by and large rational, it follows there are facts captured by tensed beliefs not captured by tenseless beliefs. There is a metaphysical tense. Prior has argued that some emotions involve tensed beliefs and Cockburn has furthered this to show that the appropriateness of some emotions depends upon these beliefs. It is inappropriate to grieve a future death or fear a past danger. I show that the appropriateness of emotions stems from the reasons they are felt for and that these reasons are revealed by the beliefs involved in these emotions. This enables me to argue that if an emotion must involve one belief rather than another to be appropriate, then this can only be because the former belief captures a reason that the latter does not. In combination with Prior/Cockburn’s conclusion I am thus able to argue, analogously to the case of rational actions, that if there are emotions which must involve tensed beliefs to be appropriate and there are examples of appropriate such emotions, then metaphysical tense is real. My thesis thus derives a conclusion about the nature of time from our nature as rational animals. These arguments also have implications for a proper understanding of first-personal indexicals, which must now be recognized to pick out facts not captured by non-first-personal language. The former of these conclusions has been famously attacked by McTaggart, and the latter by Wittgenstein, and so I will also say something to rebut these criticisms. My arguments also have implications for certain issues surrounding the cognitive significance of co-referring names/natural kind terms which I will show to be unproblematic

Risky Group Decision Making: A Comparative Analysis of FTF and CMC Teams in Stock-Trak Investment Simulations

Few studies have explicitly focused on risky group decision making in information sharing or examined the manifestation of communication differences in face-to-face (FTF) and computer-mediated communication (CMC) teams. Hypothesizing that information-sharing behaviors could be influenced not only by contextual forces but also by personality and trust, we integrate communication mode, trust and personality into a theoretical framework, and also examine the possible impact of these constructs on risky group decision-making outcomes. Our interdisciplinary study integrates the fields of information system management, investment analysis and financial education by examining both FTF and CMC teamwork in a Stock-Trak portfolio simulation. We find that contrary to the common wisdom, even though FTF team members tend to feel greater levels of trust, affiliation and satisfaction in their team collaboration process, CMC teams eventually outperform their FTF counterparts by having greater portfolio returns and investor utilities

Decay Modes of Unstable Strings in Plane-Wave String Field Theory

The cubic interaction vertex of light-cone string field theory in the plane-wave background has a simple effective form when considering states with only bosonic excitations. This simple effective interaction vertex is used in this paper to calculate the three string interaction matrix elements for states of arbitrary bosonic excitation and these results are used to examine certain decay modes on the mass-shell. It is shown that the matrix elements of one string to two string decays involving only bosonic excitations will vanish to all orders in 1/mu on the mass-shell when the number of excitations on the initial string is less than or equal to two, but in general will not vanish when the number of excitations is greater than two. Also, a truncated calculation of the mass-shell matrix elements for one string to three string decays of two excitation states is performed and suggests that these matrix elements do not vanish on the mass-shell. There is, however, a quantitative discrepancy between this last result and its (also non-vanishing) gauge theory prediction from the BMN correspondence.Comment: 11 pages; v2: references added; v3: normalization of interaction vertex and corresponding amplitudes changed by a factor of mu to reflect SFT normalization (must now divide by mu to compare with BMN dual gauge theory), and minor errors correcte

Note on Plane Wave Quantum Mechanics

We study the quantum mechanics of BMN operators with two scalar impurities and arbitrarily many traces, at one loop and all genus. We prove an operator identity which partially elucidates the structure of this quantum mechanics, provides some support for a conjectured formula for the free all genus two-point functions, and demonstrates that a single O(g_2^2) contact term arises in the Hamiltonian as a result of transforming from the natural gauge theory basis to the string basis. We propose to identify the S-matrix of this quantum mechanics with the S-matrix of string theory in the plane-wave background.Comment: (22 pages, harvmac) v2: minor change

BMN Gauge Theory as a Quantum Mechanical System

We rigorously derive an effective quantum mechanical Hamiltonian from N=4 gauge theory in the BMN limit. Its eigenvalues yield the exact one-loop anomalous dimensions of scalar two-impurity BMN operators for all genera. It is demonstrated that this reformulation vastly simplifies computations. E.g. the known anomalous dimension formula for genus one is reproduced through a one-line calculation. We also efficiently evaluate the genus two correction, finding a non-vanishing result. We comment on multi-trace two-impurity operators and we conjecture that our quantum-mechanical reformulation could be extended to higher quantum loops and more impurities.Comment: 13 pages, v2: minor changes, v3: typo corrected, to appear in Phys. Lett.

Prevalence and association of single nucleotide polymorphisms with sarcopenia in older women depends on definition

© 2020, The Author(s). The prevalence of sarcopenia depends on the definition used. There are, however, consistent sarcopenic characteristics, including a low muscle mass and muscle strength. Few studies have investigated the relationship between sarcopenia and genotype. A cross-sectional study was conducted with 307 community-dwelling ≥60-year-old women in South Cheshire, UK. Handgrip strength was assessed with a handgrip dynamometer and skeletal muscle mass was estimated using bioelectrical impedance. DNA was extracted from saliva (∼38%) or blood (∼62%) and 24 single-nucleotide polymorphisms (SNPs) were genotyped. Three established sarcopenia definitions - %Skeletal Muscle Mass (%SMM), Skeletal Muscle Mass Index (SMI) and European Working Group on Sarcopenia in Older People (EWGSOP) - were used to assess sarcopenia prevalence. Binary logistic regression with age as covariate was used to identify SNPs associated with sarcopenia. The prevalence of sarcopenia was: %SMM 14.7%, SMI 60.6% and EWGSOP 1.3%. Four SNPs were associated with the %SMM and SMI definitions of sarcopenia; FTO rs9939609, ESR1 rs4870044, NOS3 rs1799983 and TRHR rs7832552. The first three were associated with the %SMM definition, and TRHR rs7832552 with the SMI definition, but none were common to both sarcopenia definitions. The gene variants associated with sarcopenia may help proper counselling and interventions to prevent individuals from developing sarcopenia

Potential super-hard Osmium di-nitride with fluorite structure: First-principles calculations

We have performed systematic first-principles calculations on di-carbide, -nitride, -oxide and -boride of platinum and osmium with the fluorite structure. It is found that only PtN$_{2}$, OsN$_{2}$ and OsO$_{2}$ are mechanically stable. In particular OsN$_{2}$ has the highest bulk modulus of 360.7 GPa. Both the band structure and density of states show that the new phase of OsN$_{2}$ is metallic. The high bulk modulus is owing to the strong covalent bonding between Os 5\textit{d} and N 2\textit{p} states and the dense packed fluorite structure.Comment: Phys. Rev. B 74,125118 (2006

SYM Description of PP-wave String Interactions: Singlet Sector and Arbitrary Impurities

We study string interactions among string states with arbitrary impurities in the Type IIB plane wave background using string field theory. We reproduce all string amplitudes from gauge theory by computing matrix elements of the dilatation operator in a previously proposed basis of states. A direct correspondence is found between the string field theory and gauge theory Feynman diagrams.Comment: 51 pages, 8 figures. Some clarifications added, minor typos correcte