10864166
The arithmetic of certain cubic function fields
In this paper, we discuss the properties of curves of the form y3 = f(x) over a given field K of characteristic different from 3. If f(x) satisfies certain properties, then the Jacobian of such a curve is isomorphic to the ideal class group of the maximal order in the corresponding function field. We seek to make this connection concrete and then use it to develop an explicit arithmetic for the Jacobian of such curves. From a purely mathematical perspective, this provides explicit and efficient techniques for performing arithmetic in certain ideal class groups which are of fundamental interest in algebraic number theory. At the same time, it provides another source of groups which are suitable for Diffie-Hellman type protocols in cryptographic applications.
12324712
On Class Group Computations Using the Number Field Sieve
The best practical algorithm for class group computations in imaginary quadratic number fields (such as group structure, class number, discrete logarithm computations) is a variant of the quadratic sieve factoring algorithm. Paradoxical as it sounds, the principles of the number field sieve, in a strict sense, could not be applied to number field computations, yet. In this article we give an indication of the obstructions.
60530194
Qualitative researching with text, image and sound : a practical handbook
Quality, Quantity and Knowledge Interests - Martin W Bauer, George Gaskell and N C Allum Avoiding Confusions PART ONE: CONSTRUCTING A RESEARCH CORPUS Corpus Construction - Martin W Bauer and Bas Aarts A Principle for Qualitative Data Collection Individual and Group Interviewing - George Gaskell Narrative Interviewing - Sandra Jovchelovitch and Martin W Bauer Episodic Interviewing - Uwe Flick Video, Film and Photographs as Research Documents - Peter Loizos Betemology - G Fassnacht Towards Continous (Self) Observation and Personality Assessment PART TWO: ANALYTIC APPROACHES FOR TEXT, IMAGE AND SOUND Classical Content Analysis - Martin W Bauer A Review Argumentation Analysis - M Liakopoulos Discourse Analysis - Rosalind Gill Analysis of Conversation and Talk - Greg Myers Rhetorical Analysis - Joan Leach Semiotic Analysis of Still Images - Gemma Penn Analysis of Moving Images - Diana Rose Analyzing Noise and Music as Social Data - Martin W Bauer PART THREE: COMPUTER ASSISTANCE Computer-Assisted Analysis - Udo Kelle Coding and Indexing Keyword-in-Context - Nicole Kronberger and Wolfgang Wagner Statistical Analysis of Text Features PART FOUR: ISSUES OF GOOD PRACTICE Fallacies in Interpretating Historical and Social Data - Robert W D Boyce Towards Public Accountability - George Gaskell and Martin W Bauer Beyond Sampling, Reliability and Validity
9613111
Strategies for distributed search
The problem of locating information among cooperating agents within a distributed computing environment is considered. Such collections of agents can be collectively thought of as a single distributed application providing a single set of services; the X.500 distributed directory is an example of such an application. A central problem in such applications is the cooperative search for certain information which might be located at one of the agents. One approach to this problem relies on flooding messages throughout the distributed environment, such as that which might be used in routing algorithms to locate entries. Although the use of such algorithms, in principle, takes advantage of reaching many different agents via parallel data communication paths, the additional number of messages may be a distinct disadvantage in “higher layer” applications. This paper presents a variant of such approaches which rely on a depth-first method of distributing messages. Results of simulations illustrating the savings in messages of this approach to one relying on traditional flooding are presented for different network configurations.
6925738
: Functional Safety of a Theatre Stage Machinery Control System
Computer technology has the potential to significantly reduce the risks associated with scenery motion in live theatre, as well as enhancing the spectacle of performance. The industry is becoming more concerned about safety standards compliance. IEC 61508 is emerging as the universally favoured standard for functional safety of stage machinery control systems.
272027
An Interval-based Temporal Logic in a Multivalued Setting
We describe the embedding of the semantic notions and modal operators of a first-order temporal logic based on time intervals in a multivalued setting. Truth values will be realized as functions from time intervals to “ordinary” truth values like t and f. The main emphasis lies on the realization of the various modal operators contained in the temporal logic as operations on the functional truth values. We show that it is possible to obtain an efficient system sufficient for tasks in the area of diagnostic reasoning.
14555581
How to observe real-world events through a distributed world model
In this paper we propose an approach for observing real-world events through a distributed model providing dynamic data about the state of the world. Typical examples for real-world events are spatial events, i.e. events that occur when a user enters a certain spatial relationship with other users or his environment. To the best of our knowledge, this paper is the first to propose a uniform approach for observing real-world events that takes the issues related to the distribution of the model into account. The state of the world is only available with limited accuracy in both the value and time dimension, which is due to sensor inaccuracy and the properties of the distributed system. Therefore, it is not always possible to determine for certain, if an event has occurred. We propose to calculate the probability with which an event has occurred. The event is considered to have occurred when the calculated probability is above a threshold probability specified by the user. To realize this approach, we show which system parameters influence the observation, how update protocols provide the data to the observer model, on which the event is actually observed, and how the probability that an event has occurred can be calculated based on this model.