Sökresultat

Abstract in UndeterminedThe temporal non-determinism introduced by computing and communication in the form of delay and jitter can lead to significant performance degradation. To achieve good performance in systems with limited computer resources, e.g. embedded systems, the resource constraints of the implementation platform must be taken into account at design time. To facilitate this, software t

The molecular relationship of placental mammals has attracted great interest in recent years. However, 2 crucial and conflicting hypotheses remain, one with respect to the position of the root of the eutherian tree and the other the relationship between the orders Rodentia, Lagomorpha (rabbits, hares), and Primates. Although most mitochondrial (mt) analyses have suggested that rodents have a basal

This article proposes Lagrange multiplier-based tests for the null hypothesis of no cointegration. The tests are general enough to allow for heteroskedastic and serially correlated errors, deterministic trends, and a structural break of unknown timing in both the intercept and slope. The limiting distributions of the test statistics are derived, and are found to be invariant not only with respect

Background: It is not clear whether risk factors for local recurrence after breast-conserving surgery differ in women having surgery for in situ or invasive cancer. Furthermore, the Nottingham Prognostic Index (NPI) and Nottingham Histological Grade (NHG) have been little studied as determinants of local recurrence risk. Method: In a case-control study (491 cases and 1098 controls) nested within a

We present a simple black box that takes a priority queue Q which supports find-min, insert, and delete in x-time at most t. Here x-time may be worst-case, expected, or amortized. The black-box transforms Q into a priority queue Q* that supports find-min in constant time, insert in constant x-time, and delete in x-time O(t). Moreover, if Q supports dec-key in constant time, then so does Q*.

This paper proposes a Lagrange multiplier (LM) test for the null hypothesis of cointegration that allows for the possibility of multiple structural breaks in both the level and trend of a cointegrated panel regression. The test is general enough to allow for endogenous regressors, serial correlation and an unknown number of breaks that may be located at different dates for different individuals. W

The basis of a new non-destructive method for concrete pavements is described. The method uses a hybrid approach that combines frequency domain (impact-echo) and time domain (seismic) data. The equipment and data interpretation for the hybrid approach are described. The dynamic response data are interpreted in terms of guided plate wave (Lamb wave) theory, which are shown to follow the S, Lamb mod

This paper describes the development of a novel modelling tool for evaluation of solid oxide fuel cell (SOFC) performance. An artificial neural network (ANN) is trained with a reduced amount of data generated by a validated cell model, and it is then capable of learning the generic functional relationship between inputs and outputs of the system. Once the network is trained, the ANN-driven simulat

Sharp transmission resonances have been observed in the U-235(d, Pf) U-236 reaction. The shapes of the resonances as well as the angular distributions of the associated fission fragments are analyzed together with the data obtained previously for U-234. The resonances are interpreted as being hyperdeformed rotational bands with (h) over bar(2)/2 theta = 1.8(-0.7)(+0.5) and 1.6(-0.4)(+1.0) keV and

Two-dimensional resistivity imaging using multiple gradient, Wenner and dipole-dipole electrode arrays was carried out at two field sites in Sweden and one in Nicaragua, with the objective of confirming the practical applicability of results obtained with numerical modelling. The results support earlier numerical modelling studies that concluded that the gradient array, using multiple current elec

Three rotational bands in Kr-74 were studied up to (in one case one transition short of) the maximum spin I-max of their respective single-particle configurations. Their lifetimes have been determined using the Doppler-shift attenuation method. The deduced transition quadrupole moments reveal a modest decrease, but far from a complete loss of collectivity at the maximum spin I-max. This feature, t

No abstract available

We present some results on the global existence of classical solutions for quasilinear parabolic equations with nonlinear dynamic boundary conditions in bounded domains with a smooth boundary.

Modern industrial customers, such as pulp and paper industries, have increased the vulnerability to power quality problems. A voltage source converter based high-voltage direct current (VSC-HVDC) transmission has the potential to offer high power quality when transmitting large amount of power. Therefore, in this paper, a VSC-HVDC transmission is proposed to supply such industrial plants in order

A Latin hypercube sampling method, including a reduction of spurious correlation in input data, is suggested for stochastic finite element analysis. This sampling procedure strongly improves the representation of stochastic design parameters compared to a standard Monte Carlo sampling. As the correlation control requires the number of realizations to be larger than the number of stochastic variabl

Following decades of detailed kinetic and spectroscopic evidence, two new, independent X-ray structures for the cytochrome b(6)f complex of photosynthesis now reveal the arrangement of its key electron carriers relative to each other, and to their protein ligands. But these are not predictable additions to the structural collection. The complex is dimeric, and encloses a central chamber in which p

Some future directions for mycorrhizal research are discussed. Data from The IPCC Third Assessment Reports 2001 on elevated carbon dioxide the concentration and consequences regarding global climate change, form the basis for arguments that a better understanding of the mycorrhizal activities with regard to controlling carbon flow and plant nutrient flow is essential. Mycorrhiza can be regarded as

The NorduGrid project operates a production Grid infrastructure in Scandinavia and Finland using own innovative middleware solutions. The resources range from small test clusters at academic institutions to large farms at several supercomputer centers, and are used for various scientific applications. This talk reviews the architecture and describes the Grid services, implemented via the NorduGrid