The one-round Voronoi game replayed

We consider the one-round Voronoi game, where player one (``White'', called ``Wilma'') places a set of n points in a rectangular area of aspect ratio r <=1, followed by the second player (``Black'', called ``Barney''), who places the same number of points. Each player wins the fraction of the board closest to one of his points, and the goal is to win more than half of the total area. This problem has been studied by Cheong et al., who showed that for large enough $n$ and r=1, Barney has a strategy that guarantees a fraction of 1/2+a, for some small fixed a. We resolve a number of open problems raised by that paper. In particular, we give a precise characterization of the outcome of the game for optimal play: We show that Barney has a winning strategy for n>2 and r>sqrt{2}/n, and for n=2 and r>sqrt{3}/2. Wilma wins in all remaining cases, i.e., for n>=3 and r<=sqrt{2}/n, for n=2 and r<=sqrt{3}/2, and for n=1. We also discuss complexity aspects of the game on more general boards, by proving that for a polygon with holes, it is NP-hard to maximize the area Barney can win against a given set of points by Wilma.Comment: 14 pages, 6 figures, Latex; revised for journal version, to appear in Computational Geometry: Theory and Applications. Extended abstract version appeared in Workshop on Algorithms and Data Structures, Springer Lecture Notes in Computer Science, vol.2748, 2003, pp. 150-16

Facility, Location and Employer-Employee Relations of German-Canadian Businesses in Canada

The purpose of this paper is an investigation into aspects of the decision-making process of German-Canadian business owners regarding the reasons for their choice of location and their assessment of the differences of some major traits of German and Canadian employees. This paper presents the results of a questionnaire that was administered by mail to German business owners in Canada. The purpose of this focus is to provide regional planners with some understanding why German owners/managers choose specific provinces or sites, and to provide managers in Canada with information concerning differences in traits of German and Canadian employees. The results of this work are that location decisions are mostly personal when it comes to choosing Canada as a country for their business, but the more we zoom into the chosen province and the specific site, the more business-related features become relevant. As far as personnel evaluations by German managers are concerned, the key result is that while at first glance it may appear that Canadians and Germans (and, by extension, Canadian and German employees) are not very different culturally, they actually are. Whereas some results appear to support common stereotypes, e.g., Canadians rank higher when it comes to politeness and tolerance, while Germans excel in job knowledge and punctuality, others are more unexpected. Among them are the results indicating no significant differences when it comes to flexibility, ambitiousness, and the acceptance of authority

STRATEGIST : a program that models strategy-driven and content-driven inference behavior

In the course of understanding a text, different readers use different inference strategies to guide their choice of interpretations of the events in the text. This is in contrast to previous computer models of understanding, which all use the content-driven inference. The separate strategies are theorized to be composed of the same component inference processes, but of different rules for application of the processes. The use of different strategies occasionally results in different results of new experimental data and a working computer program, called STRATEGIST, that models both strategy-drive and content-driven inference behavior. The rules which make up two of these strategies are presented

Parsing with parallelism : a spreading-activation model of inference processing during text understanding

The past decade of reseatch in Natural Language Processing has universally recognized that, since natural language input is almost always ambiguous with respect to its pragmatic implications, its syntactic parse, and even its lexical analysis (i.e., choice of correct word-sense for an ambiguous word), processing natural language input requires decisions about word meanings, syntactic structure, and pragmatic inferences. The lexical, syntactic, and pragmatic levels of inferencing are not as disparate as they have often been treated in both psychological and artificial intelligence research. In fact, these three levels of analysis interact to form a joint interpretation of text.ATLAST (A Three-level Language Analysis SysTem) is an implemented integration of human language understanding at the lexical, the syntactic, and the pragmatic levels. For psychological validity, ATLAST is based on results of experiments with human subjects. The ATLAST model uses a new architecture which was developed to incorporate three features: spreading activation memory, two-stage syntax, and parallel processing of syntax and semantics. It is also a new framework within which to interpret and tackle unsolved problems through implementation and experimentation

Accurate Measurement of Propagation Delay in a Multi-Span Optical Link

The principle of Correlation Optical Time Domain Reflectometry (C-OTDR) is proposed to accurately measure the propagation delay over a multi-span optical fiber link. The delay of the transmission fiber is measured in the reflective mode, while uni-directional node components are measured in a transmissive mode. Delimiting reflectors are required between the sections for accurate demarcation.Comment: 2019 International Topical Meeting on Microwave Photonics (MWP), Ottawa, Canad

Monitoring of Optical Networks Using Correlation-Aided Time-Domain Reflectometry with Direct and Coherent Detection

We report on methods to monitor the transmission path in optical networks using a correlation-based OTDR technique with direct and coherent detection. A high probing symbol rate can provide picosecond-accuracy of the fiber propagation delay, while a sensitive phase detection with a high repetition rate allows the monitoring of dynamic effects in the vicinity of the fiber. We discuss various approaches to evaluate the measured traces and show the results of a few monitoring applications.Comment: Invited paper to OECC 2023, Shanghai, July 2-6, 202

ODS-materials for high temperature applications in advanced nuclear systems

AbstractA ferritic ODS-alloy (Fe-14Cr-1W-0.25Ti) has been manufactured by application of the powder metallurgical production route involving at first mechanical alloying of ∼10kg pre-alloyed steel powder together with an Y2O3 addition for 12h in a high energy industrial ball mill under hydrogen atmosphere at the company ZOZ GmbH. As a next step, one part of the alloyed powder was hot extruded into rods while another portion was hot isostatically pressed into plates. Both materials were then heat treated. A characterization program on these ODS-alloy production forms included microstructural and mechanical investigations: SANS and TEM assume the existence of Y2Ti2O7 nano clusters and show a bimodal distribution of ODS-particle sizes in both ODS variants. EBSD maps showed a strong 〈110〉 texture corresponding to the α fiber for the hot extruded ODS and a slight 〈001〉 texture for the hipped ODS material. Fracture toughness tests in different specimen orientations (extruded ODS) with mini 0.2T C(T) specimens together with Charpy impact tests revealed anisotropic mechanical properties: Promising (fracture) toughness levels were obtained in the specimen orientation perpendicular to the extrusion direction, while the toughness levels remained low in extrusion direction and generally for the hipped ODS material at all test temperatures. The fracture toughness tests were performed according to ASTM E 1921 and 1820 standards