From Raster to Vectors: Extracting Visual Information from Line Drawings

Vectorisation of raster line images is a relatively mature subject in the document analysis and recognition field, but it is far from being perfect as yet. We survey the methods and algorithms developed to-date for the vectorisation of document images, and classify them into six categories: Hough transform-based, thinning-based, contour-based, run-graph-based, mesh-pattern-based, and sparse-pixel-based. The purpose of the survey is to provide researchers with a comprehensive overview of this technique, to enable a judicious decision while selecting a vectorisation algorithm for a system under development or a newly developed vectorisation algorithm. Received: 10 November 1998?Received in revised form: 7 January 1999?Accepted: 7 January 1999     

Development and validation of safety climate scales for mobile remote workers using utility/electrical workers as exemplar

Purpose

The objective of this study was to develop and test the reliability and validity of a new scale designed for measuring safety climate among mobile remote workers, using utility/electrical workers as exemplar. The new scale employs perceived safety priority as the metric of safety climate and a multi-level framework, separating the measurement of organization- and group-level safety climate items into two sub-scales. The question of the emergence of shared perceptions among remote workers was also examined.

Method

For the initial survey development, several items were adopted from a generic safety climate scale and new industry-specific items were generated based on an extensive literature review, expert judgment, 15-day field observations, and 38 in-depth individual interviews with subject matter experts (i.e., utility industry electrical workers, trainers and supervisors of electrical workers). The items were revised after 45 cognitive interviews and a pre-test with 139 additional utility/electrical workers. The revised scale was subsequently implemented with a total of 2421 workers at two large US electric utility companies (1560 participants for the pilot company and 861 for the second company). Both exploratory (EFA) and confirmatory factor analyses (CFA) were adopted to finalize the items and to ensure construct validity. Reliability of the scale was tested based on Cronbach's α. Homogeneity tests examined whether utility/electrical workers’ safety climate perceptions were shared within the same supervisor group. This was followed by an analysis of the criterion-related validity, which linked the safety climate scores to self-reports of safety behavior and injury outcomes (i.e., recordable incidents, missing days due to work-related injuries, vehicle accidents, and near misses).

Results

Six dimensions (Safety pro-activity, General training, Trucks and equipment, Field orientation, Financial Investment, and Schedule flexibility) with 29 items were extracted from the EFA to measure the organization-level safety climate. Three dimensions (Supervisory care, Participation encouragement, and Safety straight talk) with 19 items were extracted to measure the group-level safety climate. Acceptable ranges of internal consistency statistics for the sub-scales were observed. Whether or not to aggregate these multi-dimensions of safety climate into a single higher-order construct (overall safety climate) was discussed. CFAs confirmed the construct validity of the developed safety climate scale for utility/electrical workers. Homogeneity tests showed that utility/electrical workers’ safety climate perceptions were shared within the same supervisor group. Both the organization- and group-level safety climate scores showed a statistically significant relationship with workers’ self-reported safety behaviors and injury outcomes.

Implications

A valid and reliable instrument to measure the essential elements of safety climate for utility/electrical workers in the remote working situation has been introduced. The scale can provide an in-depth understanding of safety climate based on its key dimensions and show where improvements can be made at both group and organization levels. As such, it may also offer a valuable starting point for future safety interventions.     

扩展青霉侵染对苹果果实膜磷脂代谢的影响

目的:研究扩展青霉侵染对苹果果实膜透性及膜磷脂代谢的影响.方法:以'元帅'苹果为试材,测定扩展青霉损伤接种果实病健交界处组织的细胞膜透率、膜磷脂代谢关键酶活力以及相关底物和产物含量的变化.结果:扩展青霉侵染早期(2 d前)果实病斑直径无明显变化,侵染后期(2 d后)果实病斑直径和细胞膜透率明显增大.侵染期间,果实的磷脂...     

The dynamic balance of import and export of zinc in Escherichia coli suggests a heterogeneous population response to stress

Zinc is essential for life, but toxic in excess. Thus all cells must control their internal zinc concentration. We used a systems approach, alternating rounds of experiments and models, to further elucidate the zinc control systems in Escherichia coli. We measured the response to zinc of the main specific zinc import and export systems in the wild-type, and a series of deletion mutant strains. We interpreted these data with a detailed mathematical model and Bayesian model fitting routines. There are three key findings: first, that alternate, non-inducible importers and exporters are important. Second, that an internal zinc reservoir is essential for maintaining the internal zinc concentration. Third, our data fitting led us to propose that the cells mount a heterogeneous response to zinc: some respond effectively, while others die or stop growing. In a further round of experiments, we demonstrated lower viable cell counts in the mutant strain tested exposed to excess zinc, consistent with this hypothesis. A stochastic model simulation demonstrated considerable fluctuations in the cellular levels of the ZntA exporter protein, reinforcing this proposal. We hypothesize that maintaining population heterogeneity could be a bet-hedging response allowing a population of cells to survive in varied and fluctuating environments.     

Is Correction of Iron Deficiency a New Addition to the Treatment of the Heart Failure?

Anemia is present in about 40% of heart failure (HF) patients. Iron deficiency (ID) is present in about 60% of the patients with anemia (about 24% of all HF patients) and in about 40% of patients without anemia (about 24% of all HF patients). Thus ID is present in about half the patients with HF. The ID in HF is associated with reduced iron stores in the bone marrow and the heart. ID is an independent risk factor for severity and worsening of the HF. Correction of ID with intravenous (IV) iron usually corrects both the anemia and the ID. Currently used IV iron preparations are very safe and effective in treating the ID in HF whereas little information is available on the effectiveness of oral iron. In HF IV iron correction of ID is associated with improvement in functional status, exercise capacity, quality of life and, in some studies, improvement in rate of hospitalization for HF, cardiac structure and function, and renal function. Large long-term adequately-controlled intervention studies are needed to clarify the effect of IV iron in HF. Several heart associations suggest that ID should be routinely sought for in all HF patients and corrected if present. In this paper we present our approach to diagnosis and treatment of iron deficiency in heart failure.     

The convergence of a PLL with variable parameters

A phase-locked loop with variable parameters is considered. In such a system it is possible to obtain a short convergence time together with a small bandwidth. It is supposed that the PLL's parameters cannot be switched and there is a restriction on the velocity of the parameter variation. An optimal strategy of parameter variation is obtained which gives an improvement in convergence time by a factor of about 30 in comparision to fixed parameter and small-bandwidth PLLs.     

An additive model of test anxiety: Role of exam-specific expectations.

The study tested a hypothesis whereby anxiety concerning examinations covering different subjects is an additive function of dispositional test anxiety and the anticipated results of individual tests. This hypothesis was generated on the basis of the integration of test anxiety theory and appraisal models of emotion. The study involved 118 students who took 3 examinations during the course of a Scholastic Aptitude Test preparation class, namely Quantitative, Verbal, and English (as a foreign language). Results with a repeated-measures design indicated that expected success, measured with self-efficacy for grade attainment 3 days before each test, incrementally predicted anxiety level during the test (i.e., beyond the prediction offered by test anxiety [trait], general efficacy [trait], and self-efficacy ratings for the previous exam). The same results were obtained when anxiety level was residualized on the basis of anxiety level associated either with the previous exam or with the Quantitative exam. These data indicate that anxiety level associated with different exams is an incremental function of dispositional and situational factors. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Empathy and ego development.

Examined the relationship between empathy and ego development to determine whether, as J. Loevinger (1976) suggested, empathy is characteristic of higher levels of ego development. 51 undergraduates (dormitory advisors) completed the Affective Sensitivity Scale (a measure of empathy) and the Loevinger Sentence Completion Test (a measure of ego development). Analysis of test scores indicated that Ss at higher levels of ego development (I-? and above) had significantly higher empathy scores than did those at lower ego levels. Findings have implications for the selection and training of individuals to serve in counseling or quasi-counseling roles. (21 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of a respite from work on burnout: Vacation relief and fade-out.

In a quasi-experiment designed to examine the relief from job stress and burnout afforded by a vacation respite, 76 clerks completed measures of job stress and burnout twice before a vacation, once during vacation, and twice after vacation. There was a decline in burnout during the vacation and a return to prevacation levels by the time of the second postvacation measure. Comparing the two prevacation measures indicated no anticipation effects. However the return to work showed gradual fade-out, as burnout returned part way toward its prevacation level by 3 days after the vacation and all the way by 3 weeks after the vacation. Women and those satisfied with their vacations experienced greater relief; however, both subsamples also experienced the quickest fade-out. The respite effect and its complete fade-out were detected among all subgroups analyzed. Burnout, relief, interpersonal stress crossover, and burnout climate at work are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)