Magnetic and transport properties of the new antiferromagnetic Kondo-lattice CeNiBi2

We report results of the first studies on the magnetic and transport properties of a new material CeNiBi_2. The magnetic susceptibility exhibits a sharp peak at T_N = 6K, indicating an antiferromagnetic phase transition. This antiferromagnetic order below T_N is confirmed by magnetization measurement, which displays a metamagnetic-like transition at H_m = 5 T. Both low-temperature susceptibility and high-field magnetization are suggestive of strong crystalline-electric-field effect in CeNiBi_2. The electrical resistivity shows the presence of Kondo and crystal-field effects with a sharp drop below TN due to the antiferromagnetic ordering. This sharp drop below T_N in the electrical resistivity is suppressed slightly to higher temperatures by an applied magnetic field to 18 T. With increasing magnetic field, the slope of magnetoresistance changes from positive to negative, being indicative of the transition to a ferromagnetic state.Comment: 11 pages, including 4 figure

Knowledge representation for culturally competent personal robots: requirements, design principles, implementation, and assessment

Culture, intended as the set of beliefs, values, ideas, language, norms and customs which compose a person’s life, is an essential element to know by any robot for personal assistance. Culture, intended as that person’s background, can be an invaluable source of information to drive and speed up the process of discovering and adapting to the person’s habits, preferences and needs. This article discusses the requirements posed by cultural competence on the knowledge management system of a robot. We propose a framework for cultural knowledge representation that relies on (i) a three layer ontology for storing concepts of relevance, culture specific information and statistics, person-specific information and preferences; (ii) an algorithm for the acquisition of person-specific knowledge, which uses culture specific knowledge to drive the search; (iii) a Bayesian Network for speeding up the adaptation to the person by propagating the effects of acquiring one specific information onto interconnected concepts. We have conducted a preliminary evaluation of the framework involving 159 Italian and German volunteers and considering 122 among habits, attitudes and social norms