Ridge extraction and its application to surface meshing

Geometrical feature lines, such as ${{\mathcal{C}}}^1Geometrical feature lines, such as -discontinuity lines, lines of curvature, ridges, asymptotic lines, etc., provide useful information about the surface geometry. The inclusion of these lines into a surface mesh contributes to improving the quality of the geometrical approximation, independently from the element size. In particular, if the element size is locally large with respect to the minimal radius of curvature, then the geometrical approximation of the surface will generally be poor. In this case, the presence of ridges in the mesh improves the geometrical approximation. This paper proposes a new method to extract the extremal graph whose graph nodes are the umbilics and the extremal points, and edges are extremal lines. A function is also introduced to classify the extremal lines to be able to select the ridges from a parametric surface. The resulting graph of ridges is then simplified and integrated as a constraint in a classical surface mesh generation via an indirect approach. A numerical example will illustrate the pertinence of this method.

Boris Clémen?onEmail:

     

Algorithms for additive clustering of rectangular data tables

The overlapping additive clustering model or principal cluster model is a model for two-way two-mode object by variable data that implies an overlapping clustering of the objects and a set of profiles (characteristic variable values for each cluster). The model values of the variables of an object are the sum of the profiles of its corresponding clusters. In the associated data analysis the data matrix at hand is approximated by an overlapping additive clustering model of a prespecified rank by minimizing a least squares loss function. Recently an algorithm has been proposed for this purpose. This algorithm is a sequential fitting strategy, also called the method of principal clusters (PCL). Theoretical and empirical evidence that the PCL algorithm may have problems in revealing the true structure underlying a data set will be presented. As a way out, three new algorithms to fit the principal cluster model to empirical data will be presented: two of an alternating least squares (ALS) type, orthogonally combined with two different starting strategies, and one based on simulated annealing (SA). In a simulation study it is demonstrated that all three new algorithms outperform the existing PCL algorithm. The amount of objects that belong to more than one cluster (the overlap) is further found to have a considerable influence on the algorithmic performance of the ALS algorithms, with low amounts of overlap requiring a different starting strategy than high ones. As a consequence, for the analysis of real data sets in practice, a hybrid approach will be presented consisting of one of the ALS algorithms initialized by means of the two starting strategies under study.     

Concept Learning and Feature Selection Based on Square-Error Clustering

Based on a reinterpretation of the square-error criterion for classical clustering, a separate-and-conquer version of K-Means clustering is presented and a contribution weight is determined for each variable of every cluster. The weight is used to produce conjunctive concepts that describe clusters and to reduce or transform the variable (feature) space.     

一个基于XML的Agent通信框架

Agent通信是多Agnet系统的核心活动之一,是Agent相互协调、合作、竞争和完成任务的基础。Agent通信语言为此提供了一种高层次、灵活、通用的通信模式。在KQML和FIPA－ACL的基础上提出通用Agent通信语言的概念,阐述构建通用ACL的重要性和可行性,深入讨论一个基于XML的Agent通信框架,最后给出实例。     

Chromatic dispersion and losses of microstructured optical fibers

Using a rigorous and vector multipole method, we compute both losses and dispersion properties of microstructured optical fibers with finite cross sections. We restrict our study to triangular lattices of air-hole inclusions in a silica matrix, taking into account material dispersion. The fiber core is modeled by a missing inclusion. The influence of pitch, hole diameter, and number of hole rings on chromatic dispersion is described, and physical insights are given to explain the behavior observed. It is shown that flattened dispersion curves obtained for certain microstructured fiber configurations are unsuitable for applications because of the fibers' high losses and that they cannot be improved by a simple increase of the number of air-hole rings.     

Recovery of Fine and Ultrafine Mineral Particles by Electroflotation – A Review

Fine and ultrafine particles are successfully recovered by flotation when fine bubbles are present. Electroflotation is a technique in which fine bubbles are generated by the electrolysis of water. This article reviews the experimental studies into mineral recovery by electroflotation and the potential application of electrolytic bubbles in the recovery of fine and ultrafine mineral particles. The literature reveals that electroflotation resulted in better recoveries of ultrafine particles (e.g. dolomite, magnesite, and pyrite) as compared with dispersed-air flotation because electrolytic bubbles are smaller in size and are more active than those generated during dispersed-air flotation.     

Ethical and legal considerations in marital and family therapy.

Notes insufficiencies in the American Psychological Association's ethical standards for marriage and family therapy. Guidelines regarding therapist responsibility, confidentiality, and informed consent sometimes become ambiguous with individual clients, but they are even more complicated when multiple family members are seen together in therapy. Questions about confidentiality, refusal of treatment, and value of conflicts between the family members and the therapist may arise. Consideration of these questions in terms of their ethical implications is complex and controversial. Yet answers to these questions must also take into account clinical and legal considerations, which sometimes run a collision course with what is desirable from a strictly ethical standpoint. Examples and preliminary recommendations with respect to these issues are examined; further clarification of professional conduct in marital and family therapy is urged. (45 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Variability in outcome and clinical significance of behavioral marital therapy: A reanalysis of outcome data.

Reanalyzed the data from the following studies evaluating the effectiveness of behavioral marital therapy to see what proportion of couples improved and how many join the ranks of happily married couples: D. H. Baucom (see record 1982-21665-001), K. Hahlweg et al (see record 1983-26163-001), N. S. Jacobson (see record 1984-21130-001), and G. Margolin and R. L. Wiess (see record 1979-26577-001). Data on 148 couples showed that slightly more than half improved and deterioration was rare. (35 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Endogenous opiate reward induced by an enkephalinase inhibitor, thiorphan, injected into the ventral midbrain.

Opiates are known to be reinforcing when injected into the ventral tegmental area (VTA). The present study, with 87 female Sprague-Dawley rats, produced conditioned reinforcement with local injections of exogenous d-ala–2-met–5-enkephalinamide (DALA), a potent analog of met-enkephalin, and with thiorphan, an enkephalinase inhibitor that protects endogenous opiates from enzymic degradation. In a conditioned place perference paradigm, Ss received injections of DALA (1.0, 3.0, or 8.0 μg), thiorphan (60 μg), and/or naloxone (10 μg), or saline vehicle. Conditioned reinforcement was obtained with 8.0 μg of DALA and also with thiorphan but not with thiorphan plus naloxone. This suggests that reward can be generated by endogenous opiates in the VTA. Tests during the light phase and dark phase suggested that diurnal periodicity may play a role in opiate reward. It is concluded that the VTA can generate conditioned reward through transmitter–receptor interaction involving an endogenous opiate substrate that is probably enkephalinergic. (29 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

StopGap: elastic VMs to enhance server consolidation

Virtualized cloud infrastructures (also known as IaaS platforms) generally rely on a server consolidation system to pack virtual machines (VMs) on as few servers as possible. However, an important limitation of consolidation is not addressed by such systems. Because the managed VMs may be of various sizes (small, medium, large, etc.), VM packing may be obstructed when VMs do not fit available spaces. This phenomenon leaves servers with a set of unused resources (‘holes’). It is similar to memory fragmentation, a well‐known problem in operating system domain. In this paper, we propose a solution which consists in resizing VMs so that they can fit with holes. This operation leads to the management of what we call elastic VMs and requires cooperation between the application level and the IaaS level, because it impacts management at both levels. To this end, we propose a new resource negotiation and allocation model in the IaaS, called HRNM. We demonstrate HRNM's applicability through the implementation of a prototype compatible with two main IaaS managers (OpenStack and OpenNebula). By performing thorough experiments with SPECvirt_sc2010 (a reference benchmark for server consolidation), we show that the impact of HRNM on customer's application is negligible. Finally, using Google data center traces, we show an improvement of about 62.5% for the traditional consolidation engines. Copyright © 2017 John Wiley & Sons, Ltd.