SHOP2: An HTN Planning System

The SHOP2 planning system received one of the awards for distinguished performance in the 2002 International Planning Competition. This paper describes the features of SHOP2 which enabled it to excel in the competition, especially those aspects of SHOP2 that deal with temporal and metric planning domains

Logarithmic perturbation theory for quasinormal modes

Logarithmic perturbation theory (LPT) is developed and applied to quasinormal modes (QNMs) in open systems. QNMs often do not form a complete set, so LPT is especially convenient because summation over a complete set of unperturbed states is not required. Attention is paid to potentials with exponential tails, and the example of a Poschl-Teller potential is briefly discussed. A numerical method is developed that handles the exponentially large wavefunctions which appear in dealing with QNMs.Comment: 24 pages, 4 Postscript figures, uses ioplppt.sty and epsfig.st

Developmental dyscalculia and low numeracy in Chinese children

Children struggle with mathematics for different reasons. Developmental dyscalculia and low numeracy - two kinds of mathematical difficulties - may have their roots, respectively, in poor understanding of exact non-symbolic numerosities and of symbolic numerals. This study was the first to explore whether Chinese children, despite cultural and linguistic factors supporting their mathematical learning, also showed such mathematical difficulties and whether such difficulties have measurable impact on children's early school mathematical performance. First-graders, classified as dyscalculia, low numeracy, or normal achievement, were compared for their performance in various school mathematical tasks requiring a grasp of non-symbolic numerosities (i.e., non-symbolic tasks) or an understanding of symbolic numerals (i.e., symbolic tasks). Children with dyscalculia showed poorer performance than their peers in non-symbolic tasks but not symbolic ones, whereas those with low numeracy showed poorer performance in symbolic tasks but not non-symbolic ones. As hypothesized, these findings suggested that dyscalculia and low numeracy were distinct deficits and caused by deficits in non-symbolic and symbolic processing, respectively. These findings went beyond prior research that only documented generally low mathematical achievements for these two groups of children. Moreover, these deficits appeared to be persistent and could not be remedied simply through day-to-day school mathematical learning. The present findings highlighted the importance of tailoring early learning support for children with these distinct deficits, and pointed to future directions for the screening of such mathematical difficulties among Chinese children. © 2013 Elsevier Ltd.postprin

Weaknesses in motivation and in establishing a meritocratic system: A portrait of the Portuguese public administration

The complexities of Public Administration have gained the growing attention of scholars around the world, mainly due to the impacts of the reforms implemented under the doctrine of New Public Management (which aims to apply concepts and practices of private management in public management) on civil servants. The aim of this study is to find out how Portuguese citizens evaluate the Portuguese Public Administration under the aspects of bureaucracy, organisation of human resources, innovation, skills and attitudes of civil servants, its motivation and recognition; and to verify if there are differences of opinion between respondents working in public sector and respondents from other sectors. This study follows a quali-quantitative approach, and data were collected through an online survey in the period from June to December 2020. The survey was answered by 1119 citizens from all districts of Portugal. The main findings reveal a still high level of bureaucracy in the Portuguese Public Administration; weaknesses in the management of human resources, namely regarding the motivation and recognition of civil servants; and difficulties in the establishment of a meritocratic system of recruitment and performance evaluation of civil servants. Statistically significant evaluation differences (chi-square test and non-parametric Mann–Whitney U tests, involving five hypotheses) were found between the public sector and other sectors, except for the motivation variable.info:eu-repo/semantics/publishedVersio

Eigenvectors in the Superintegrable Model II: Ground State Sector

In 1993, Baxter gave $2^{m_Q}$ eigenvalues of the transfer matrix of the $N$-state superintegrable chiral Potts model with spin-translation quantum number $Q$, where $m_Q=\lfloor(NL-L-Q)/N\rfloor$. In our previous paper we studied the Q=0 ground state sector, when the size $L$ of the transfer matrix is chosen to be a multiple of $N$. It was shown that the corresponding $\tau_2$ matrix has a degenerate eigenspace generated by the generators of $r=m_0$ simple $sl_2$ algebras. These results enable us to express the transfer matrix in the subspace in terms of these generators $E_m^{\pm}$ and $H_m$ for $m=1,...,r$. Moreover, the corresponding $2^r$ eigenvectors of the transfer matrix are expressed in terms of rotated eigenvectors of $H_m$.Comment: LaTeX 2E document, using iopart.cls with iopams packages. 17 pages, uses eufb10 and eurm10 fonts. Typeset twice! vs2: Many changes and additions, adding 7 pages. vs3: minor corrections. vs4 minor improvement

Magnetic Dipole Sum Rules for Odd-Mass Nuclei

Sum rules for the total- and scissors-mode M1 strength in odd-A nuclei are derived within the single-j interacting boson-fermion model. We discuss the physical content and geometric interpretation of these sum rules and apply them to ^{167}Er and ^{161}Dy. We find consistency with the former measurements but not with the latter.Comment: 13 pages, Revtex, 1 figure, Phys. Rev. Lett. in pres

Perturbative Approach to the Quasinormal Modes of Dirty Black Holes

Using a recently developed perturbation theory for uasinormal modes (QNM's), we evaluate the shifts in the real and imaginary parts of the QNM frequencies due to a quasi-static perturbation of the black hole spacetime. We show the perturbed QNM spectrum of a black hole can have interesting features using a simple model based on the scalar wave equation.Comment: Published in PR

Symmetries of Large N Matrix Models for Closed Strings

We obtain the symmetry algebra of multi-matrix models in the planar large N limit. We use this algebra to associate these matrix models with quantum spin chains. In particular, certain multi-matrix models are exactly solved by using known results of solvable spin chain systems.Comment: 12 pages, 1 eps figure, RevTex, some minor typos in the publised version are correcte

BOVA is Superior to sPESI in Identification of High Risk Pulmonary Embolism Patients

Introduction: Prognostic models exist for the purpose of stratifying patients with acute pulmonary embolism. Of these, the Pulmonary Embolism Severity Index (PESI) and the simplified PESI (sPESI) are the most well-known, although more recent composite models, like the BOVA score, are now being studied and implemented. Comparative efficacy of these scores to predict long term mortality is not well established. Methods: We performed a retrospective analysis of all consecutive patients diagnosed with PE using computed tomography scan from 2014-2016 at an urban tertiary-referral medical center. Cox proportional hazard analyses were performed to compare the performance of two prognostic models – sPESI and BOVA – to predict all-cause in-hospital and cumulative one-year mortality. Results: The all-cause in-hospital mortality rate was 6.0%, and cumulative one-year mortality rate was 21.3%. In adjusted analyses, a BOVA score \u3e4 was significantly associated with an increased in-hospital mortality (HR 3.5, 95% CI: 1.4-9.0, p = 0.009) and one-year mortality (HR 2.0, 95% CI: 1.0-3.9, p = 0.04), as compared to a BOVA score \u3c4. However, the sPESI (p = 0.14) did not show a significant association with one-year mortality. In identifying in-hospital mortality, the sPESI had high sensitivity (100%) and low specificity (10.1%), whereas the BOVA score had low sensitivity (20.0%) and high specificity (92.7%). Similar trends were seen for one-year mortality. Conclusion: In this study, a high BOVA score was found to be the best predictor of both short and long-term mortality in PE patients. A low sPESI score identified with high sensitivity patients with low-risk PEs