Relational networks of conditional preferences

Much like relational probabilistic models, the need for relational preference models naturally arises in real-world applications involving multiple, heterogeneous, and richly interconnected objects. On the one hand, relational preferences should be represented into statements which are natural for human users to express. On the other hand, relational preference models should be endowed with a structure that supports tractable forms of reasoning and learning. Based on these criteria, this paper introduces the framework of relational conditional preference networks (RCP-nets), that maintains the spirit of the popular ??CP-nets?? by expressing relational preferences in a natural way using the ceteris paribus semantics. We show that acyclic RCP-nets support tractable inference for optimization and ranking tasks. In addition, we show that in the online learning model, tree-structured RCP-nets (with bipartite orderings) are efficiently learnable from both optimization tasks and ranking tasks, using linear loss functions. Our results are corroborated by experiments on a large-scale movie recommendation dataset.     

Deciphering the human nucleolar proteome

Nucleoli are plurifunctional nuclear domains involved in the regulation of several major cellular processes such as ribosome biogenesis, the biogenesis of non-ribosomal ribonucleoprotein complexes, cell cycle, and cellular aging. Until recently, the protein content of nucleoli was poorly described. Several proteomic analyses have been undertaken to discover the molecular bases of the biological roles fulfilled by nucleoli. These studies have led to the identification of more than 700 proteins. Extensive bibliographic and bioinformatic analyses allowed the classification of the identified proteins into functional groups and suggested potential functions of 150 human proteins previously uncharacterized. The combination of improvements in mass spectrometry technologies, the characterization of protein complexes, and data mining will assist in furthering our understanding of the role of nucleoli in different physiological and pathological cell states.     

Distribution-insensitive cluster analysis in SAS on real-time PCR gene expression data of steadily expressed genes

Cluster analysis is a tool often employed in the micro-array techniques but used less in the real-time PCR. Herein we present core SAS code that instead of the Euclidian distances takes correlation coefficient as a dissimilarity measure. The dissimilarity measure is made robust using a rank-order correlation coefficient rather than a parametric one. There is no need for an overall probability adjustment like in scoring methods based on repeated pair-wise comparisons. The rank-order correlation matrix gives a good base for the clustering procedure of gene expression data obtained by real-time RT-PCR as it disregards the different expression levels. Associated with each cluster is a linear combination of the variables in the cluster, which is the first principal component. Large set of variables can then be replaced by the set of cluster components with little loss of information. In this way, distinct clusters containing unregulated housekeeping genes along with other steadily expressed genes can be disclosed and utilized for standardization purposes. Simulated data in parallel with the data from a biological experiment were taken to validate the SAS macro. For both cases, good intuitive results were obtained.     

高职高专“机床电气控制”课程教学改革的探讨

高职高专院校实行的是"厚基础、宽口径,强能力"的人才培养模式,针对"机床电气控制"这门实践性和应用性较强的专业课,应在教学内容上突出知识应用的系统性,教学方法上强化工程能力的培养,教学手段上采用板书与多媒体教学相结合三位一体的教学改革,有利于激发学生的学习热情,提高学生的操作技能,增强学生创新意识和社会竞争力。     

哥特小说《瘸者先入》中恶棍形象的分析

《瘸者先入》以10岁小男孩诺顿的上吊自杀作为结尾,给读者带来无尽的忧伤和悲愤。他自私冷漠的父亲谢帕德有着不可推卸的责任,跛脚的鲁夫斯.约翰逊的对诺顿的死也起到了推波助澜的作用,两人作恶的形式不同,但都应遭到谴责。如果说约翰逊的恶棍形象是作者对传统哥特文学的继承,谢帕德的恶行则是作者对人性弱点的揭示,同时也是对哥特文学的创新。     

Hybrid approaches for the two‐scenario max–min knapsack problem

In this paper, we deal with the two‐scenario max–min knapsack (MNK) problem. First, we consider several formulations of MNK as a mixed integer programming problem. Then, we propose a hybrid method as an alternative to solve the MNK exactly. The approach combines relaxation technique and the temporary setting of variables to improve iteratively two sequences of upper and lower bounds. More precisely, pseudo‐cuts are added to the problem to strengthen the bounds and reduce the gap between the best lower bound and the best upper bound. The algorithm stops when the proof of the optimality of the best solution is found. We also use a reduction technique to set some variables definitively at their optimal values. Numerical experiments demonstrate the robustness of the approach. In particular, our algorithm is efficient to solve large and correlated instances of MNK.     

On the Grundy and b-Chromatic Numbers of a Graph

The Grundy number of a graph G, denoted by Γ(G), is the largest k such that G has a greedy k-colouring, that is a colouring with k colours obtained by applying the greedy algorithm according to some ordering of the vertexes of G. The b-chromatic number of a graph G, denoted by χ _b (G), is the largest k such that G has a b-colouring with k colours, that is a colouring in which each colour class contains a b-vertex, a vertex with neighbours in all other colour classes. Trivially χ _b (G),Γ(G)≤Δ(G)+1. In this paper, we show that deciding if Γ(G)≤Δ(G) is NP-complete even for a bipartite graph G. We then show that deciding if Γ(G)≥|V(G)|?k or if χ _b (G)≥|V(G)|?k are fixed parameter tractable problems with respect to the parameter k.     

A Multigrid Method on Non-Graded Adaptive Octree and Quadtree Cartesian Grids

In order to develop efficient numerical methods for solving elliptic and parabolic problems where Dirichlet boundary conditions are imposed on irregular domains, Chen et al. (J. Sci. Comput. 31(1):19–60, 2007) presented a methodology that produces second-order accurate solutions with second-order gradients on non-graded quadtree and octree data structures. These data structures significantly reduce the number of computational nodes while still allowing for the resolution of small length scales. In this paper, we present a multigrid solver for this framework and present numerical results in two and three spatial dimensions that demonstrate that the computational time scales linearly with the number of nodes, producing a very efficient solver for elliptic and parabolic problems with multiple length scales.     

Physiological and subjective evaluation of a human-robot object hand-over task

In the context of task sharing between a robot companion and its human partners, the notions of safe and compliant hardware are not enough. It is necessary to guarantee ergonomic robot motions. Therefore, we have developed Human Aware Manipulation Planner (Sisbot et al., 2010), a motion planner specifically designed for human–robot object transfer by explicitly taking into account the legibility, the safety and the physical comfort of robot motions. The main objective of this research was to define precise subjective metrics to assess our planner when a human interacts with a robot in an object hand-over task. A second objective was to obtain quantitative data to evaluate the effect of this interaction. Given the short duration, the “relative ease” of the object hand-over task and its qualitative component, classical behavioral measures based on accuracy or reaction time were unsuitable to compare our gestures. In this perspective, we selected three measurements based on the galvanic skin conductance response, the deltoid muscle activity and the ocular activity. To test our assumptions and validate our planner, an experimental set-up involving Jido, a mobile manipulator robot, and a seated human was proposed. For the purpose of the experiment, we have defined three motions that combine different levels of legibility, safety and physical comfort values. After each robot gesture the participants were asked to rate them on a three dimensional subjective scale. It has appeared that the subjective data were in favor of our reference motion. Eventually the three motions elicited different physiological and ocular responses that could be used to partially discriminate them.