A mildly exponential approximation algorithm for the permanent

A new approximation algorithm for the permanent of ann ×n 0,1-matrix is presented. The algorithm is shown to have worst-case time complexity exp(O(n ^1/2 log² n)). Asymptotically, this represents a considerable improvement over the best existing algorithm, which has worst-case time complexity exp((n)).Supported by SERC Grant GR/F 90363; work done in part while visiting DIMACS (Center for Discrete Mathematics and Computer Science).Supported by an NSF PYI grant, with matching equipment grant from the AT&T Foundation; work done in part while visiting DIMACS.     

An interface finite element for the simulation of localized membrane-bending deformation in shells

The folding of thin shells around localized lines occurs in several situations of engineering interest, such as in buckling induced deformation, as the consequence of crash, in industrial processes like metal forming, in the deployment of folded membranes, in packaging related processes. In this paper an interface element, allowing for displacement and rotation discontinuities, to be placed between two adjacent 4-node Mindlin–Reissner shell finite elements, is developed for a computationally effective simulation of this type of localized deformation. The large displacement and rotation kinematics of the interface element is discussed, arriving at a rigid-rotation free element tangent stiffness matrix. An adaptive dynamic relaxation scheme is proposed for the evolutionary analysis of the quasi-static structural response. To test the element formulation, a simple coupled membrane-bending elastoplastic behavior is assumed. The element is used for the simulation of few examples taken from the literature, where the structural response is characterized by the formation of plastic hinges, exhibiting good accuracy and computational effectiveness.     

Efficient multitasking in a dual-core CPU system

The paper offers an associative-neural-net method to optimize resource allocation between independent tasks in a multiprocessor system. In the case of a dual-core CPU the method allows the task to be fully solved in O(M) operations. The text was submitted by the authors in English.     

Micromechanical three-axial tactile force sensor for micromaterial characterisation

 A three-axial tactile force sensor for the investigation of micromechanical structures has been developed using silicon micromachining technology. The sensor is capable of performing mechanical micro material characterisation such as the determination of the spring constant of complex micromechanical structures. Another application for this sensor is dimensional metrology where it has been tested as a 3D probe in a test set-up for coordinate measurements.     

On the analysis of stochastic divide and conquer algorithms

This paper develops general tools for the analysis of stochastic divide and conquer algorithms. We concentrate on the average performance and the distribution of the running time of the algorithm. As a special example we analyse the average performance and the running time distribution of the (2k + 1)-median version of Quicksort. Online publication October 13, 2000.     

Integration of medical responsibility

The article describes responsibility as a term with six relations and four different levels. It analyses the conflicts between different addresses, levels and values and emphasizes the need to integrate the responsibilities of the physician. The term "responsibility" provides a more differentiating analytical tool for conflicts in medical acting than the so-called "principles of biomedical ethics".     

A trial with diclofenac HEP plaster as topical treatment in minor sport injuries

Diclofenac HEP plaster was tested in an open study in the treatment of different traumatic sport and overload injuries, to confirm the results of efficacy and tolerability already shown in other clinical studies. A total of 101 patients were assigned to treatment and were eligible for the evaluation of results at the end of a 14-day treatment period. The average score of spontaneous pain, assessed by means of a verbal scale and a visual analogical scale, showed a clear difference in pain rating between the beginning and end of treatment. In general 60% pain reduction was observed. The difference in analgesic activity was already apparent on the 7th day of treatment (-28%). The reduction of pain was confirmed by changes in another subjective sign related to the injury: provoked pain. This symptom decreased in a manner comparable to spontaneous pain: 61% pain reduction after 2 weeks of treatment. Global assessment of efficacy, performed by the investigator at the end of treatment, showed the clear therapeutic activity of local treatment with diclofenac HEP plaster. Satisfactory results were obtained and only 18% of the patients (most of them with chronic and persistent pain) experienced ineffective pain relief at the end of the 2-week treatment. The beneficial effects of diclofenac HEP plaster on pain are confirmed by the patients' assessment, since almost identical scores were obtained. It is striking that the overall tolerance of diclofenac HEP plaster, applied topically twice a day for 2 weeks, was "good" or "excellent" in the 101 patients treated. Any side effect was reported on the patient's card and all the patients completed the study.