742 research outputs found
Model Checking CTL is Almost Always Inherently Sequential
The model checking problem for CTL is known to be P-complete (Clarke,
Emerson, and Sistla (1986), see Schnoebelen (2002)). We consider fragments of
CTL obtained by restricting the use of temporal modalities or the use of
negations---restrictions already studied for LTL by Sistla and Clarke (1985)
and Markey (2004). For all these fragments, except for the trivial case without
any temporal operator, we systematically prove model checking to be either
inherently sequential (P-complete) or very efficiently parallelizable
(LOGCFL-complete). For most fragments, however, model checking for CTL is
already P-complete. Hence our results indicate that, in cases where the
combined complexity is of relevance, approaching CTL model checking by
parallelism cannot be expected to result in any significant speedup. We also
completely determine the complexity of the model checking problem for all
fragments of the extensions ECTL, CTL+, and ECTL+
The Equal Rights Amendment: A Constitutional Basis for Equal Rights for Women
In the present legal structure, some laws exclude women from legalrights, opportunities, or responsibilities. Some are framed as legislationconferring special benefits, or protection, on women. Others create orperpetuate a separate legal status without indicating on their facewhether the position of women ranks below, or above, the positionof men. Many of the efforts to create a separate legal status for womenstem from a good faith attempt to advance the interests of women.Nevertheless, the preponderant effect has been to buttress the socialand economic subordination of women
The Quantum Mechanics of Hyperion
This paper is motivated by the suggestion [W. Zurek, Physica Scripta, T76,
186 (1998)] that the chaotic tumbling of the satellite Hyperion would become
non-classical within 20 years, but for the effects of environmental
decoherence. The dynamics of quantum and classical probability distributions
are compared for a satellite rotating perpendicular to its orbital plane,
driven by the gravitational gradient. The model is studied with and without
environmental decoherence. Without decoherence, the maximum quantum-classical
(QC) differences in its average angular momentum scale as hbar^{2/3} for
chaotic states, and as hbar^2 for non-chaotic states, leading to negligible QC
differences for a macroscopic object like Hyperion. The quantum probability
distributions do not approach their classical limit smoothly, having an
extremely fine oscillatory structure superimposed on the smooth classical
background. For a macroscopic object, this oscillatory structure is too fine to
be resolved by any realistic measurement. Either a small amount of smoothing
(due to the finite resolution of the apparatus) or a very small amount of
environmental decoherence is sufficient ensure the classical limit. Under
decoherence, the QC differences in the probability distributions scale as
(hbar^2/D)^{1/6}, where D is the momentum diffusion parameter. We conclude that
decoherence is not essential to explain the classical behavior of macroscopic
bodies.Comment: 17 pages, 24 figure
Метод расчета теплообмена излучением в топке осесимметричной конфигурации на основе уравнений для компонент суммарного вектора потока лучистой энергии. Инженерная методика
На основе системы уравнений первой части статьи, получены разностные уравнения квазиодномерного метода расчета теплообмена излучением в топке котла осесимметричной конфигурации. Записаны уравнения и разностные формулы метода инженерного расчета теплообмена излучением при наличии экранной сетки около поверхности горелки. Методика пригодна для использования в инженерных расчетах при определении оптимальной конфигурации топки и определении оптимального расстояния экранной сетки до поверхности горелки
Deciphering the Grand Village of the Illinois: A Preliminary Assessment of the Grand Village Research Project
On April 24, 1987, Thomas Emerson at the State Historic Preservation Office received a telephone call from a Chicago lawyer who wanted an answer to a simple question: Are there any laws that protect old Indian villages and graves that are on the National Register? Unfortunately, the answer was a simple “no.” At the time, Emerson did not suspect that this question would initiate a more than four-year struggle to save one of the most important historic sites in the country. The site, known variously as the Zimmerman site, the Grand Village of the Kaskaskia, Old Kaskaskia Village, the Grand Village of the Illinois, or simply llLS13, was purchased by developers who planned to build vacation homes on it. Eventually, after a private and public campaign that reached an international level, Governor James Thompson authorized the Illinois Historic Preservation Agency (IHPA) to seek condemnation of the property to bring it into public ownership. In April 1991, a final settlement was reached and the site was purchased by the state. It is currently under the administration of the IHPA and has been renamed the Grand Village of the Illinois State Historic Site.
The Grand Village is the most important surviving village and burial site of the seventeenth-century Illinois Confederacy. In addition, it is the location of the initial French-Illinois contact and of the first Catholic mission in the Illinois Country. The site also contains materials that represent an unbroken sequence of late prehistoric, protohistoric, and Historic Indian cultural development from the ninth to the last quarter of the eighteenth century
Linear growth in preschool children treated with mass azithromycin distributions for trachoma: A cluster-randomized trial.
BackgroundMass azithromycin distributions have been shown to reduce mortality among pre-school children in sub-Saharan Africa. It is unclear what mediates this mortality reduction, but one possibility is that antibiotics function as growth promoters for young children.Methods and findings24 rural Ethiopian communities that had received biannual mass azithromycin distributions over the previous four years were enrolled in a parallel-group, cluster-randomized trial. Communities were randomized in a 1:1 ratio to either continuation of biannual oral azithromycin (20mg/kg for children, 1 g for adults) or to no programmatic antibiotics over the 36 months of the study period. All community members 6 months and older were eligible for the intervention. The primary outcome was ocular chlamydia; height and weight were measured as secondary outcomes on children less than 60 months of age at months 12 and 36. Study participants were not masked; anthropometrists were not informed of the treatment allocation. Anthropometric measurements were collected for 282 children aged 0-36 months at the month 12 assessment and 455 children aged 0-59 months at the month 36 assessment, including 207 children who had measurements at both time points. After adjusting for age and sex, children were slightly but not significantly taller in the biannually treated communities (84.0 cm, 95%CI 83.2-84.8, in the azithromycin-treated communities vs. 83.7 cm, 95%CI 82.9-84.5, in the untreated communities; mean difference 0.31 cm, 95%CI -0.85 to 1.47, P = 0.60). No adverse events were reported.ConclusionsPeriodic mass azithromycin distributions for trachoma did not demonstrate a strong impact on childhood growth.Trial registrationThe TANA II trial was registered on clinicaltrials.gov #NCT01202331
Sparse Positional Strategies for Safety Games
We consider the problem of obtaining sparse positional strategies for safety
games. Such games are a commonly used model in many formal methods, as they
make the interaction of a system with its environment explicit. Often, a
winning strategy for one of the players is used as a certificate or as an
artefact for further processing in the application. Small such certificates,
i.e., strategies that can be written down very compactly, are typically
preferred. For safety games, we only need to consider positional strategies.
These map game positions of a player onto a move that is to be taken by the
player whenever the play enters that position. For representing positional
strategies compactly, a common goal is to minimize the number of positions for
which a winning player's move needs to be defined such that the game is still
won by the same player, without visiting a position with an undefined next
move. We call winning strategies in which the next move is defined for few of
the player's positions sparse.
Unfortunately, even roughly approximating the density of the sparsest
strategy for a safety game has been shown to be NP-hard. Thus, to obtain sparse
strategies in practice, one either has to apply some heuristics, or use some
exhaustive search technique, like ILP (integer linear programming) solving. In
this paper, we perform a comparative study of currently available methods to
obtain sparse winning strategies for the safety player in safety games. We
consider techniques from common knowledge, such as using ILP or SAT
(satisfiability) solving, and a novel technique based on iterative linear
programming. The results of this paper tell us if current techniques are
already scalable enough for practical use.Comment: In Proceedings SYNT 2012, arXiv:1207.055
Effects of preovulatory estradiol on uterine environment and conceptus survival from fertilization to maternal recognition of pregnancy
Preovulatory estradiol is known to impact embryo quality and survival. The objective of this study was to determine the effects of preovulatory estradiol on the uterine environment and conceptus survival through maternal recognition of pregnancy. Beef cows/heifers were AIed following induced ovulation. Cows were grouped into high and low preovulatory estradiol. Conceptuses were collected on day 16 nonsurgically (Rep 1; n = 20), or following slaughter (Rep 2; n = 29). Blood was collected to determine plasma glucose concentrations, and uterine luminal fluid (ULF) was analyzed for protein, glucose, and interferon tau (IFNT) concentrations. Total cellular RNA was extracted from caruncular (CAR) and intercaruncular (INCAR) endometrial tissue. There was no effect of preovulatory estradiol on conceptus recovery rate (P = 0.38) or on apoptosis rate in the trophectoderm (P = 0.64). Cows in which a conceptus was recovered had greater concentrations of protein in the ULF (P = 0.04). Animals with elevated preovulatory estradiol had greater endometrial abundance of SLC2A1 (P = 0.05) and SLC5A1 (P = 0.04) in both INCAR and CAR tissue. Presence of a conceptus also tended to increase (P = 0.10) abundance of SLC5A1 in INCAR. In CAR tissue, cows with a conceptus had decreased SLC2A4 abundance (P = 0.05). In summary, conceptus recovery rates, apoptosis in the trophectoderm, IFNT, glucose, and protein concentration in ULF did not differ between cows that did or did not have an increase in preovulatory estradiol concentrations. Thus, there is no indication of increased conceptus survival to day 16 of pregnancy based on estradiol concentrations
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