An Extended Quadratic Frobenius Primality Test with Average- and Worst-Case Error Estimate

We present an Extended Quadratic Frobenius Primality Test (EQFT), which is related to the Miller-Rabin test and to several other known probabilistic tests. EQFT takes time equivalent to about two or three Miller-Rabin tests, but has a much smaller error probability, namely 256/331776^t for t iterations of the test in the worst case. We also give bounds on the average-case behaviour of the test: consider the algorithm that repeatedly chooses random odd k bit numbers, subjects them to t iterations of our test and outputs the first one found that passes all tests. We obtain numeric upper bounds for the error probability of this algorithm as well as a general closed expression bounding the error. For instance, it is at most 2^-155 for k = 500, t = 2. Compared with earlier similar results for the Miller-Rabin test, the results indicate that our test in the average case has the effect of nine Miller-Rabin tests. We also give bounds for the error in case a prime is sought by incremental search from a random starting point.     

Hume box calculus: robust system development through software transformation

Hume is a contemporary programming language oriented to systems with strong resource bounds, based on autonomous concurrent “boxes” interacting across “wires”. Hume’s design reflects the explicit separation of coordination and computation aspects of multi-process systems, which greatly eases establishing resource bounds for programs. However, coordination and computation are necessarily tightly coupled in reasoning about Hume programs. Furthermore, in Hume, local changes to coordination or computation, while preserving input/output correctness, can have profound and unforeseen effects on other aspects of programs such as timing of events and scheduling of processes. Thus, traditional program calculi prove inappropriate as they tend to focus exclusively either on the coordination of interacting processes or on computation within individual processes.     

Dynamic normal forms and dynamic characteristic polynomial

We present the first fully dynamic algorithm for computing the characteristic polynomial of a matrix. In the generic symmetric case, our algorithm supports rank-one updates in O(n²logn) randomized time and queries in constant time, whereas in the general case the algorithm works in O(n²klogn) randomized time, where k is the number of invariant factors of the matrix. The algorithm is based on the first dynamic algorithm for computing normal forms of a matrix such as the Frobenius normal form or the tridiagonal symmetric form. The algorithm can be extended to solve the matrix eigenproblem with relative error 2^−b in additional O(nlog²nlogb) time. Furthermore, it can be used to dynamically maintain the singular value decomposition (SVD) of a generic matrix. Together with the algorithm, the hardness of the problem is studied. For the symmetric case, we present an Ω(n²) lower bound for rank-one updates and an Ω(n) lower bound for element updates.     

Kinetic analysis of the liquid phase hydrogenation of 2-ethyl-hexenal in the presence of supported Ni,Pd and Ni-S catalysts

The kinetics of the consecutive hydrogenation reactions 2-ethyl-hexenal → 2-ethyl-hexanal → 2-ethyl-hexanol were studied in the liquid phase in presence of commercial Ni, Pd and Ni-S catalysts. The Pd and Ni-S catalysts were extremely selective with respect to the formation of 2-ethyl-hexanal, while the full reaction sequence was readily catalyzed by nickel. A Langmuir-Hinshelwood model with dissociative hydrogen adsorption was found to be the most probable model, for all three catalysts. The proposal of dissociative hydrogen adsorption of the Ni-S catalyst was supported by an independent gas-phase experiment, using the H₂/D₂ exchange reaction as a model reaction for the hydrogen àdsorption process.     

Creativity and aggression.

We studied problems of identification in an experiment using a meta-contrast design. The first stimulus in the pair (A) was the word I shown subliminally. The second stimulus (B) depicted an aggressor and a victim facing each other. To manipulate the subject's identification, the subliminal A was flashed either on the victim or on the aggressor, or was completely withheld. Subjects were 28 16-year-olds of both sexes. They also took a perceptgenetic (PG) test measuring creativity and a test on anxiety and defensive strategies as revealed in the perceptual process (the meta-contrast technique or MCT). It was predicted that creative subjects would identify more openly with the aggressor than noncreative ones, when I was presented on the aggressor. Differences in the use of defenses were also expected. The results supported the predictions. It was concluded that creative subjects are more self-reliant than noncreative ones, more inclined to believe in the value of private impressions and ideas. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A joint industry field expedition to study ice conditions in Pechora Sea, 1993

This paper describes the arrangements of an international joint industry field study on the ice conditions in the Pechora Sea in 1993. In the near future the Pechora Sea will attract the petroleum industry, and the areas developed then will be offshore structures like pipelines, production structures, a tanker terminal, and ice breaking vessels including tankers and icebreakers. The ice field work in the area started in winter 1992 when a Russian-Finnish expedition (by the Finnish-Russian Offshore Technology Working Group) was made. The main companies involved in the commissioning of the expedition were the Kvrner Masa-Yards Arctic Research Centre (MARC), the Arctic Offshore Research Centre of Helsinki University of Technology (AORC), and the Arctic Marine Geological expedition (AMIGE). During the winter of 1993 the same group and, in addition, the Polar Research Institute of Fishing and Oceanography (PINRO) arranged the second expedition to the Pechora Sea funded by five petroleum companies: AMOCO, EXXON, NESTE, NORSK HYDRO, and TEXACO.Published in Gidrotekhnicheskoe Stroitel'stvo, No. 8, pp. 28–29, August, 1994.     

Psychological distortions of the research process: A summary of psychotherapeutic explorations.

Presents the results of a psychotherapeutic research project concerning psychological blocks to research and creativity. Clients were 10 established researchers and postgraduate students who were offered psychoanalytically based focal-insight therapy. Some of the crucial personal-dynamic problems that hindered the normal development of the knowledge constructing aims of the researcher were anxiety-identity, separation, fear of criticism, competition and envy, research as a means of aggressive outlet, and intellectualization as a mechanism of defense. Illustrative case material is presented. The constructive role of anxiety in research is discussed together with the necessity of viewing research not only as an intellectual but also as an emotional activity. Findings reveal the impact of life situation on research and show a relationship between insight in therapy and the research process. (21 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)