Asymptotic stress intensity factor density profiles for smeared-tip method for cohesive fracture

The paper presents a computational approach and numerical data which facilitate the use of the smeared-tip method for cohesive fracture in large enough structures. In the recently developed K-version of the smeared tip method, the large-size asymptotic profile of the stress intensity factor density along a cohesive crack is considered as a material characteristic, which is uniquely related to the softening stress-displacement law of the cohesive crack. After reviewing the K-version, an accurate and efficient numerical algorithm for the computation of this asymptotic profile is presented. The algorithm is based on solving a singular Abel's integral equation. The profiles corresponding to various typical softening stress-displacement laws of the cohesive crack model are computed, tabulated and plotted. The profiles for a certain range of other typical softening laws can be approximately obtained by interpolation from the tables. Knowing the profile, one can obtain with the smeared-tip method an analytical expression for the large-size solution to fracture problems, including the first two asymptotic terms of the size effect law. Consequently, numerical solutions of the integral equations of the cohesive crack model as well as finite element simulations of the cohesive crack are made superfluous. However, when the fracture process zone is attached to a notch or to the body surface and the cohesive zone ends with a stress jump, the solution is expected to be accurate only for large-enough structures.     

Syllables as processing units in handwriting production.

This research focused on the syllable as a processing unit in handwriting. Participants wrote, in uppercase letters, words that had been visually presented. The interletter intervals provide information on the timing of motor production. In Experiment 1, French participants wrote words that shared the initial letters but had different syllable boundaries. In Experiment 2, French- and Spanish-speaking participants wrote cognates and pseudowords with a letter sequence that was always intrasyllabic in French and intersyllabic in Spanish. In Experiment 3, French-Spanish bilinguals wrote the cognates and pseudowords with the same type of sequences. In the 3 experiments, the critical interletter intervals were longer between syllables than within syllables, indicating that word syllable structure constrains motor production both in French and Spanish. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A histopathologic study of direct pulp-capping with adhesive resins

The concentration of heat-shock proteins of 70 kD (HSP70) in heart tissue has been shown to increase during transient myocardial ischaemia and to persist during several hours of reperfusion. In this study the relationship between the local myocardial HSP70 concentration and blood flow was addressed for control physiological conditions and acute myocardial ischaemia. A specific aim of this study was to address the question of whether low flow areas under control physiological conditions have undergone a transient ischaemia during the preceding hours and thus may be in a state of hibernation or stunning. In 12 anaesthetized, open-chest beagle dogs (6 control and 6 with 60-min coronary artery stenosis) heart rate, mean aortic pressure, mean arterial partial pressure of O2 and partial pressure of CO2 averaged 85+/-16 beats/min, 94+/-14 mmHg, 102+/-17 mmHg and 39+/-6 mmHg, respectively. Regional HSP70 and myocardial blood flow (RMBF) were measured using an HSP70-enzyme-linked immunosorbent assay and the tracer microsphere technique, respectively, in samples of 250 mg wet mass. In the control group the mean RMBF was 1.06+/-0.59 ml.min-1.g-1 and the local HSP70 concentration was 7.08+/-1.03 microg/mg cytosolic protein. Myocardial HSP70 showed a blood flow-independent regional biological heterogeneity, equivalent to a coefficient of variation of 0.31. Local HSP70 concentrations did not differ (P>0.05) between control low and high flow samples, 6.16+/-1.0 vs 6.08+/-0.75 microg/mg cytosolic protein, respectively. However, after 60 min of coronary artery occlusion the local HSP70 concentration increased from 7.08 +/-1.03 to 13.43+/-3.19 microg/mg cytosolic protein (P<0. 001). There was a significant inverse relationship between the percent reduction of local blood flow and HSP70 (r=-0.56, P<0.001). From these results it is concluded that: (1) low flow samples under control physiological conditions are unlikely to be in a state of hibernation or stunning since their HSP70 concentration is normal and (2) the increase in the local HSP70 concentration during myocardial ischaemia reflects the degree of impairment of O2 delivery.     

A group priority earliest deadline first scheduling algorithm

In most priority scheduling algorithms, the number of priority levels is assumed to be unlimited. However, if a task set requires more priority levels than the system can support, several jobs must in practice be assigned the same priority level. To solve this problem, a novel group priority earliest deadline first (GPEDF) scheduling algorithm is presented. In this algorithm, a schedulability test is given to form a job group, in which the jobs can arbitrarily change their order without reducing the schedulability. We consider jobs in the group having the same priority level and use shortest job first (SJF) to schedule the jobs in the group to improve the performance of the system. Compared with earliest deadline first (EDF), best effort (BE), and group-EDF (gEDF), simulation results show that the new algorithm exhibits the least switching, the shortest average response time, and the fewest required priority levels. It also has a higher success ratio than both EDF and gEDF.     

基于强跟踪滤波器的开关变换器故障诊断

Buck变换器又称降压变换器、串联开关稳压电源、三端开关型降压稳压器。广泛用于计算机、家用电器、控制系统和通信系统中的电源几乎都是开关电源,具有超快速负载动态响应、高功率变换效率、高功率密度、低电压、大电流的特性.开关变换器作为它的主要电路,故障率较高,对它故障诊断研究是有意义的。基于强跟踪滤波理论,给出了一种开关变换器电路故障实时诊断的一种方法。该方法以建立一种开关变换器电路状态空间模型为基础,利用强跟踪滤波器对电路状态及元件参数进行估计,当元件参数发生软、硬型故障时,根据强跟踪滤波器对元件参数的跟踪结果及修正的Bayes分类算法,可实时诊断开关变换器电路中的元件故障。仿真结果证明了该方法的有效性。     

ANDES: efficient evaluation of NOT-twig queries in relational databases

Despite a large body of work on XPath query processing in relational environment, systematic study of queries containing not-predicates have received little attention in the literature. Particularly, several xml supports of industrial-strength commercial rdbms fail to efficiently evaluate such queries. In this paper, we present an efficient and novel strategy to evaluate not -twig queries in a tree-unaware relational environment. not -twig queries are XPath queries with ancestor–descendant and parent–child axis and contain one or more not-predicates. We propose a novel Dewey-based encoding scheme called Andes (ANcestor Dewey-based Encoding Scheme), which enables us to efficiently filter out elements satisfying a not-predicate by comparing their ancestor group identifiers. In this approach, a set of elements under the same common ancestor at a specific level in the xml tree is assigned same ancestor group identifier. Based on this scheme, we propose a novel sql translation algorithm for not-twig query evaluation. Experiments carried out confirm that our proposed approach built on top of an off-the-shelf commercial rdbms significantly outperforms state-of-the-art relational and native approaches. We also explore the query plans selected by a commercial relational optimizer to evaluate our translated queries in different input cardinality. Such exploration further validates the performance benefits of Andes.     

Retraction of “Using ergonomic digital human modeling in evaluation of workplace design and prevention of workrelated musculoskeletal disorders onboard small fishing vessel”

The following article from Human Factors and Ergonomics in Manufacturing & Service Industries, “Using ergonomic digital human modeling in evaluation of workplace design and prevention of workrelated musculoskeletal disorders onboard small fishing vessel,” by Enrique Álvarez‐Casado, Bing Zhang, Sonia Tello Sandoval and Mondelo Pedro, published online on October 11, 2011 in Wiley Online Library ( www.onlinelibrary.wiley.com ), has been retracted by agreement between the authors, the journal Editors‐in‐Chief, Waldemar Karwowski and Gavriel Salvendy, and Publisher Wiley Periodicals, Inc. The retraction has been agreed as these articles were mistakenly published after being rejected.