241 research outputs found
Versatile Cold Atom Source for Multi-Species Experiments
We present a dual-species oven and Zeeman slower setup capable of producing
slow, high-flux atomic beams for loading magneto-optical traps. Our compact and
versatile system is based on electronic switching between different magnetic
field profiles and is applicable to a wide range of multi-species experiments.
We give details of the vacuum setup, coils and simple electronic circuitry. In
addition, we demonstrate the performance of our system by optimized, sequential
loading of magneto-optical traps of lithium-6 and cesium-133.Comment: 7 pages, 10 figure
Mechanical Team Final Design Report: Same Polytechnic College
The purpose of this document is to communicate the research, findings, and recommendations of the mechanical engineering team regarding the Same Polytechnic College project. This report includes a discussion of the design process utilized by the interdisciplinary team to construct preliminary building designs for both classroom and dormitory building modules. The mechanical team conducted testing using the wind tunnel to verify major building envelope design decisions. The following report also includes an explanation of the thermal testing that the team conducted to measure the thermal conductivity, diffusivity, and specific heat of bricks made to mimic those made locally in Same, Tanzania. The test combines predictions made in EES, transient testing using thermocouples, calorimetry, and MATLAB. The report concludes with recommendations made by the mechanical team for future design implementations
ALE Defeasible Description Logic
One of Semantic Web strengths is the ability to address incomplete knowledge. However, at present, it cannot handle incomplete knowledge directly. Also, it cannot handle non-monotonic reasoning. In this paper, we extend ALE Defeasible Description Logic with existential quantifier, i.e., ALE Defeasible Description Logic. Also, we modify some parts of the logic, resulting in an increasing efficiency in its reasoning
Defeasible Logic: Agency, Intention and Obligation
We propose a computationally oriented non-monotonic multi-modal logic arising from the combination of agency, intention and obligation. We argue about the defeasible nature of these notions and then we show how to represent and reason with them in the setting of defeasible logic
Comparative concept similarity over Minspaces: Axiomatisation and Tableaux Calculus
We study the logic of comparative concept similarity \CSL introduced by
Sheremet, Tishkovsky, Wolter and Zakharyaschev to capture a form of qualitative
similarity comparison. In this logic we can formulate assertions of the form "
objects A are more similar to B than to C". The semantics of this logic is
defined by structures equipped by distance functions evaluating the similarity
degree of objects. We consider here the particular case of the semantics
induced by \emph{minspaces}, the latter being distance spaces where the minimum
of a set of distances always exists. It turns out that the semantics over
arbitrary minspaces can be equivalently specified in terms of preferential
structures, typical of conditional logics. We first give a direct
axiomatisation of this logic over Minspaces. We next define a decision
procedure in the form of a tableaux calculus. Both the calculus and the
axiomatisation take advantage of the reformulation of the semantics in terms of
preferential structures.Comment: 25 page
Changing legal systems: Abrogation and annulment. Part I: Revision of defeasible theories
In this paper we investigate how to model legal abrogation and annulment in Defeasible Logic. We examine some options that embed in this setting, and similar rule-based systems, ideas from belief and base revision. In both cases, our conclusion is negative, which suggests to adopt a different logical model
Collimated dual species oven source and its characterisation via spatially resolved fluorescence spectroscopy
We describe the design, construction and characterisation of a collimated, dual-species oven source for generating intense beams of lithium and caesium in UHV environments. Our design produces full beam overlap for the two species. Using an aligned microtube array the FWHM of the output beam is restricted to ~ 75 milliradians, with an estimated axial brightness of 3.6x10[superscript]14 atoms s[superscript]-1 sr[superscript]-1 for Li and 7.4x10[superscript]15 atoms s[superscript]-1 sr[superscript]-1 for Cs. We measure the properties of the output beam using a spatially-resolved fluorescence technique, which allows for the extraction of additional information not accessible without spatial resolution
Genomics of Ocular Chlamydia trachomatis After 5 Years of SAFE Interventions for Trachoma in Amhara, Ethiopia.
BACKGROUND: To eliminate trachoma as a public health problem, the World Health Organization recommends the SAFE (surgery, antibiotics, facial cleanliness, and environmental improvement) strategy. As part of the SAFE strategy in the Amhara Region, Ethiopia, the Trachoma Control Program distributed >124 million doses of antibiotics between 2007 and 2015. Despite this, trachoma remained hyperendemic in many districts and a considerable level of Chlamydia trachomatis (Ct) infection was evident. METHODS: We utilized residual material from Abbott m2000 Ct diagnostic tests to sequence 99 ocular Ct samples from Amhara and investigated the role of Ct genomic variation in continued transmission of Ct. RESULTS: Sequences were typical of ocular Ct at the whole-genome level and in tissue tropism-associated genes. There was no evidence of macrolide resistance in this population. Polymorphism around the ompA gene was associated with village-level trachomatous inflammation-follicular prevalence. Greater ompA diversity at the district level was associated with increased Ct infection prevalence. CONCLUSIONS: We found no evidence for Ct genomic variation contributing to continued transmission of Ct after treatment, adding to evidence that azithromycin does not drive acquisition of macrolide resistance in Ct. Increased Ct infection in areas with more ompA variants requires longitudinal investigation to understand what impact this may have on treatment success and host immunity
BIO Logical Agents: Norms, Beliefs, Intentions in Defeasible Logic
In this paper we follow the BOID (Belief, Obligation, Intention, Desire) architecture to describe agents and agent types in Defeasible Logic. We argue, in particular, that the introduction of obligations can provide a new reading of the concepts of intention and intentionality. Then we examine the notion of social agent (i.e., an agent where obligations prevail over intentions) and discuss some computational and philosophical issues related to it. We show that the notion of social agent either requires more complex computations or has some philosophical drawbacks
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