2,580 research outputs found
Multi-Robot Planning on Dynamic Topological Graphs using Mixed-Integer Programming
Planning for multi-robot teams in complex environments is a challenging
problem, especially when these teams must coordinate to accomplish a common
objective. In general, optimal solutions to these planning problems are
computationally intractable, since the decision space grows exponentially with
the number of robots. In this paper, we present a novel approach for
multi-robot planning on topological graphs using mixed-integer programming.
Central to our approach is the notion of a dynamic topological graph, where
edge weights vary dynamically based on the locations of the robots in the
graph. We construct this graph using the critical features of the planning
problem and the relationships between robots; we then leverage mixed-integer
programming to minimize a shared cost that depends on the paths of all robots
through the graph. To improve computational tractability, we formulated our
optimization problem with a fully convex relaxation and designed our decision
space around eliminating the exponential dependence on the number of robots. We
test our approach on a multi-robot reconnaissance scenario, where robots must
coordinate to minimize detectability and maximize safety while gathering
information. We demonstrate that our approach is able to scale to a series of
representative scenarios and is capable of computing optimal coordinated
strategic behaviors for autonomous multi-robot teams in seconds.Comment: \copyright 2023 IEEE. Personal use of this material is permitted.
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The role of gender in the relations among Dark Triad and psychopathy, sociosexuality, and moral judgments
The Dark Triad (D3) traits of narcissism, Machiavellianism, and psychopathy have been linked to a range of moral behavior, and to sociosexuality and sexual behavior, particularly in males. The current study examined whether males and females differ with respect to relations among D3 traits and dimensions of psychopathy from the Triarchic Psychopathy Measure (TriPM), sexual behavior, sociosexuality, tendency towards infidelity, and moral judgments, using a community sample. D3 and TriPM measures were generally more strongly correlated with sexual behavior for males in ways that might increase numbers of matings and sexual partners, but were more strongly correlated with intention towards infidelity and sociosexual attitudes for females—in ways that might facilitate extra-pair mating. Sociosexuality and self-reported sexual behavior showed a strong pattern of overall and gender-specific relations to moral judgments. D3 and psychopathy measures were also related to everyday moral judgments, although generally less so than were sociosexuality and sexual behavior. These results clearly point to the importance of taking gender into account when considering the relations between D3 traits, sexual behavior, sociosexuality, and moral judgments
Inverse Function: Pre-Service Teachers’ Techniques and Meanings
Researchers have argued teachers and students are not developing connected meanings for function inverse, thus calling for a closer examination of teachers’ and students’ inverse function meanings. Responding to this call, we characterize 25 pre-service teachers’ inverse function meanings as inferred from our analysis of clinical interviews. After summarizing relevant research, we describe the methodology and theoretical framework we used to interpret the pre-service teachers’ activities. We then present data highlighting the techniques the pre-service teachers used when responding to tasks that involved analytical and graphical representations of functions and inverse functions in both decontextualized and contextualized situations and discuss our inferences of their meanings based on their activities. We conclude with implications for the teaching and learning of inverse function and areas for future research
Ab initio molecular dynamics calculations of ion hydration free energies
We apply ab initio molecular dynamics (AIMD) methods in conjunction with the
thermodynamic integration or "lambda-path" technique to compute the intrinsic
hydration free energies of Li+, Cl-, and Ag+ ions. Using the
Perdew-Burke-Ernzerhof functional, adapting methods developed for classical
force field applications, and with consistent assumptions about surface
potential (phi) contributions, we obtain absolute AIMD hydration free energies
(Delta G(hyd)) within a few kcal/mol, or better than 4%, of Tissandier 's [J.
Phys. Chem. A 102, 7787 (1998)] experimental values augmented with the SPC/E
water model phi predictions. The sums of Li+/Cl- and Ag+/Cl- AIMD Delta G(hyd),
which are not affected by surface potentials, are within 2.6% and 1.2 % of
experimental values, respectively. We also report the free energy changes
associated with the transition metal ion redox reaction Ag++Ni+-> Ag+Ni2+ in
water. The predictions for this reaction suggest that existing estimates of
Delta G(hyd) for unstable radiolysis intermediates such as Ni+ may need to be
extensively revised.Comment: 18 pages, 8 figures. This version is essentially the one published in
J. Chem. Phy
Micro-Raman Study of Stress Distribution Generated in Silicon During Proximity Rapid Thermal Diffusion
proximity rapid thermal diffusion (RTD). A compressive stress was found on the whole silicon wafer after 15 s RTD. After 165 s RTD, the distribution of the stress across the wafer was found to be different: compressive at the edge and tensile at the middle. Thermal stress was relieved in the RTD wafers via slip dislocations. These slip dislocations were observed in the product wafers using optical microscopy. Slip lines propagated from the wafer edge to the wafer centre in eight preferred positions of maximum induced stress. The thermally induced stress and the slip dislocation density increased with time spent at the RTD peak temperature
Custom rates for farm services in Missouri
"The custom rates reported in this guide were revised based on a statewide survey conducted in January 1986. Questionnaires were sent to farmers, agri-business firms, aerial applicators, and land improvement contractors known to be performing custom services. Rate data from the questionnaires were tabulated according to the most common rate reported, a simple average of all rates, and the range of the rates reported for the custom service being performed."--First page.Kevin C. Moore, Richard K. Rudel and Gerald M. Ehlmann (Department of Agricultural Economics), and Donald L. Pfost (Department of Agricultural Engineering, College of Agriculture)Revised 5/86/15
The metabolism and de-bromination of bromotyrosine in vivo
During inflammation, leukocyte-derived eosinophil peroxidase catalyses the formation of hypobromous acid, which can brominate tyrosine residues in proteins to form bromotyrosine. Since eosinophils are involved in the pathogenesis of allergic reactions, such as asthma, urinary bromotyrosine level has been used for the assessment of children with asthma. However, little is known about the metabolism and disposition of bromotyrosine in vivo. The aim of this study was to identify the major urinary metabolites formed during bromotyrosine metabolism and to develop mass spectrometric methods for their quantitation. Deuterium-labeled bromotyrosine was synthesized by deuterium exchange. [D3]bromotyrosine (500 nmole) was injected intraperitoneally into Sprague-Dawley rats and urine was collected for 24 h in a metabolic cage. 13C-labeled derivatives of bromotyrosine and its major urinary metabolite were synthesized and used as internal standards for quantitation. Following solid phase extraction, urine samples were derivatized to the pentafluorobenzyl ester, and analyzed using isotope dilution gas chromatography and negative-ion chemical ionization mass spectrometry. A novel brominated metabolite, 3-bromo-4-hydroxyphenylacetic acid (bromo-HPA), was identified as the major brominated metabolite of bromotyrosine. Bromo-HPA only accounted for 0.43±0.04% of infused [D3]bromotyrosine and 0.12±0.02% of infused [D3]bromotyrosine was excreted in the urine unchanged. However, ~1.3% (6.66±1.33 nmole) of infused [D3]bromotyrosine was excreted in the urine as the de-brominated metabolite, [D3]4-hydroxyphenylacetic acid, which is also a urinary metabolite of tyrosine in mammals. We also tested whether or not iodotyrosine dehalogenase can catalyse de-bromination of bromotyrosine and showed that iodotyrosine dehalogenase is able to de-brominate free bromotyrosine in vitro. We identified bromo-HPA as the main brominated urinary metabolite of bromotyrosine in rats. However, de-halogenation of bromotyrosine is the major metabolic pathway to eliminate free brominated tyrosine in vivo
Whole genome sequencing for mutation discovery in a single case of lysosomal storage disease (MPS type 1) in the dog.
Mucopolysaccharidosis (MPS) is a metabolic storage disorder caused by the deficiency of any lysosomal enzyme required for the breakdown of glycosaminoglycans. A 15-month-old Boston Terrier presented with clinical signs consistent with lysosomal storage disease including corneal opacities, multifocal central nervous system disease and progressively worsening clinical course. Diagnosis was confirmed at necropsy based on histopathologic evaluation of multiple organs demonstrating accumulation of mucopolysaccharides. Whole genome sequencing was used to uncover a frame-shift insertion affecting the alpha-L-iduronidase (IDUA) gene (c.19_20insCGGCCCCC), a mutation confirmed in another Boston Terrier presented 2 years later with a similar clinical picture. Both dogs were homozygous for the IDUA mutation and shared coat colors not recognized as normal for the breed by the American Kennel Club. In contrast, the mutation was not detected in 120 unrelated Boston Terriers as well as 202 dogs from other breeds. Recent inbreeding to select for recessive and unusual coat colors may have concentrated this relatively rare allele in the breed. The identification of the variant enables ante-mortem diagnosis of similar cases and selective breeding to avoid the spread of this disease in the breed. Boston Terriers carrying this variant represent a promising model for MPS I with neurological abnormalities in humans
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