A statistical, nonparametric methodology for document degradation model validation

Printing, photocopying, and scanning processes degrade the image quality of a document. Statistical models of these degradation processes are crucial for document image understanding research. In this paper, we present a statistical methodology that can be used to validate local degradation models. This method is based on a nonparametric, two-sample permutation test. Another standard statistical device, the power function, is then used to choose between algorithm variables such as distance functions. Since the validation and the power function procedures are independent of the model, they can be used to validate any other degradation model. A method for comparing any two models is also described. It uses p-values associated with the estimated models to select the model that is closer to the real world.     

Integrated reconfiguration and age-based preventive maintenance decision making

The use of manufacturing system reconfiguration in conjunction with maintenance operations has not been previously reported in the literature. This research attempts to incorporate reconfiguration into Preventive Maintenance (PM) actions for improved system performance in terms of reduced total cost. This paper presents an Integrated Reconfiguration and Age-Based Maintenance (IRABM) policy and applies it to a parallel-serial manufacturing system. The expected total cost of implementing the IRABM policy is estimated and minimized through a simulation-based heuristic optimization procedure. Using this method, it is possible to systematically identify the conditions under which the integration of reconfiguration into maintenance is cost effective. In addition, numerical examples demonstrate that the manufacturing system could have a higher probability of fulfilling production requirements at a lower cost under the IRABM policy compared to the conventional age-based PM policy. The influences of the input parameters associated with reconfiguration, production, and reliability on the performance of IRABM policy also are studied.     

Study on morphology of copper deposited onto aluminium by immersion plating from an oxalate bath containing perchloric acid

The structural characteristics of copper deposits resulting from immersion plating of copper are presented. In this study halide is replaced by perchloric acid, which is found to effectively break down the impervious oxide film from aluminium surface and to facilitate copper plating. Increase in copper concentration results in a smooth deposit, showing layered structure where crystallite grows in fine globular shape. Perchloric acid concentration has a significant effect on the deposit morphology. Increase in its concentration mainly affects the crystallite size and its distribution on the substrate surface. At higher perchloric acid concentrations no dendrite formation is observed but surface corrosion is initiated. Increase in plating temperature results in the nodular growth and also surface corrosion. The activation energy calculated from the Arrhenius plot is found to be 34.19 kJ mol⁻¹.     

Hysteresis‐Free 1D Network Mixed Halide‐Perovskite Semitransparent Solar Cells

The morphology of hybrid organic–inorganic perovskite films is known to strongly affect the performance of perovskite‐based solar cells. CH₃NH₃PbI_3‐xCl_x (MAPbI_3‐xCl_x) films have been previously fabricated with 100% surface coverage in glove boxes. In ambient air, fabrication generally relies on solvent engineering to obtain compact films. In contrast, this work explores the potential of altering the perovskites microstructure for solar cell engineering. This work starts with CH₃NH₃PbI_3‐xCl_x, films with grain morphology carefully controlled by varying the deposition speed during the spin‐coating process to fabricate efficient and partially transparent solar cells. Devices produced with a CH₃NH₃PbI_3‐xCl_x film and a compact thick top gold electrode reach a maximum efficiency of 10.2% but display a large photocurrent hysteresis. As it is demonstrated, the introduction of different concentrations of bromide in the precursor solution addresses the hysteresis issues and turns the film morphology into a partially transparent interconnected network of 1D microstructures. This approach leads to semitransparent solar cells with negligible hysteresis and efficiencies up to 7.2%, while allowing average transmission of 17% across the visible spectrum. This work demonstrates that the optimization of the perovskites composition can mitigate the hysteresis effects commonly attributed to the charge trapping within the perovskite film.     

Role of exercise training in the prevention and treatment of insulin resistance and non-insulin-dependent diabetes mellitus

Recent epidemiological studies indicate that individuals who maintain a physically active lifestyle are much less likely to develop impaired glucose tolerance and non-insulin-dependent diabetes mellitus (NIDDM). Moreover, it was found that the protective effect of physical activity was strongest for individuals at highest risk of developing NIDDM. Reducing the risk of insulin resistance and NIDDM by regularly performed exercise is also supported by several aging studies. It has been found that older individuals who vigorously train on a regular basis exhibit a greater glucose tolerance and a lower insulin response to a glucose challenge than sedentary individuals of similar age and weight. While the evidence is substantial that aerobic exercise training can reduce the risk of impaired glucose tolerance and NIDDM, the evidence that exercise training is beneficial in the treatment of NIDDM is not particularly strong. Many of the early studies investigating the effects of exercise training on NIDDM could not demonstrate improvements in fasting plasma glucose and insulin levels, or glucose tolerance. The adequacy of the training programmes in many of these studies, however, is questionable. More recent studies using prolonged, vigorous exercise-training protocols have produced more favourable results. There are several important adaptations to exercise training that may be beneficial in the prevention and treatment of insulin resistance, impaired glucose tolerance and NIDDM. An increase in abdominal fat accumulation and loss of muscle mass are highly associated with the development of insulin resistance. Exercise training results in preferential loss of fat from the central regions of the body and should therefore contribute significantly in preventing or alleviating insulin resistance due to its development. Likewise, exercise training can prevent muscle atrophy and stimulate muscle development. Several months of weight training has been found to significantly lower the insulin response to a glucose challenge without affecting glucose tolerance, and to increase the rate of glucose clearance during a euglycaemic clamp. Muscle glucose uptake is equal to the product of the arteriovenous glucose difference and the rate of glucose delivery or muscle blood flow. While it has been known for many years that insulin will accelerate blood glucose extraction by insulin-sensitive peripheral tissues, recent evidence suggests that it can also acutely vasodilate skeletal muscle and increase muscle blood flow in a dose-dependent manner. A reduced ability of insulin to stimulate muscle blood flow is a characteristic of insulin-resistant obese individuals and individuals with NIDDM. Exercise training, however, has been found to help alleviate this problem, and substantially improve the control of insulin over blood glucose. Improvements in insulin resistance and glucose tolerance with exercise training are highly related to an increased skeletal muscle insulin action. This increased insulin action is associated with an increase in the insulin-regulatable glucose transporters, GLUT4, and enzymes responsible for the phosphorylation, storage and oxidation of glucose. Changes in muscle morphology may also be important following training. With exercise training there is an increase in the conversion of fast twitch glycolytic IIb fibres to fast twitch oxidative IIa fibres, as well as an increase in capillary density. IIa fibres have a greater capillary density and are more insulin-sensitive and -responsive than IIb fibres. Evidence has been provided that morphological changes in muscle, particularly the capillary density of the muscle, are associated with changes in fasting insulin levels and glucose tolerance. Furthermore, significant correlations between glucose clearance, muscle capillary density and fibre type have been found in humans during a euglycaemic clamp. Exercise training may also improve control over hepatic glucose production by increasin     

Measurement of job and work involvement.

Developed separate measures of job and work constructs using 3 techniques: semantic differential, questionnaire, and graphic. Assessment measures included the Job Involvement and Work Involvement Questionnaires, Job Involvement and Work Involvement Semantic Differentials, and Job Involvement and Work Involvement Graphic scales. Data collected from a heterogeneous sample of 703 employees are analyzed to establish reliability, construct validity, and criterion-related validity of each measure. Results reveal that questionnaire and graphic measures pass the tests of reliability and validity. Semantic differential measures, however, have questionable validity for measuring work involvement and should, perhaps, be limited to only highly educated samples of respondents. Results also support the conceptual distinction between job and work involvement. (19 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

怀旧的台湾味

走进香港九龙湾的这家垦丁茶室,立即被一股既时尚又怀旧的台湾风情包围。在蓝与白交织的想象空间中,周遭的船木与砖块让人犹如置身码头。淡淡的怀旧风,细细地诉     

淡蓝色的梦

如果做一个关于家居的梦,你的梦是什么颜色的?对S来说,她的梦想之家应该是一抹淡淡的蒂芙尼蓝,纯净优雅得不见半点点庸俗。显然,这不是一位甘于将就的业主。对于生活与居住,她讲究又有要求,即便是租住的房子,也要来一番彻头彻尾的翻新与变革,还专门聘请设计师帮助完成这个计划,壁纸的色彩,家具的风格,每一件她都精挑细选。与很多住在房子里的人不同,她认为她是     

Evaluation of various selective media for the detection of Pseudomonas species in pasteurized milk

Pseudomonas spp. are common gram-negative, post-pasteurization contaminants that contribute to spoilage of pasteurized dairy products. This study evaluated 5 common selective media for detecting Pseudomonas spp. in pasteurized milk. The performance of each selective medium for recovering 12 different Pseudomonas isolates (selected to represent a diversity of pasteurized milk isolates) was compared with that of standard plate count agar pour plates. Pseudomonas isolates showed varying abilities to produce colonies on different selective media. For 2 of 12 isolates, a 48-h incubation time was required for colony formation on any of the media tested. Violet red bile agar and coliform Petrifilm (3M, St. Paul, MN) were less effective than standard plate count agar pour plates at recovering Pseudomonas, regardless of incubation time, and MacConkey agar showed poor detection efficiency compared with SPCP after a 48-h incubation (R(2) = 0.26). Therefore, the use of violet red bile agar, MacConkey agar, or coliform Petrifilm may not be sufficient for detecting common Pseudomonas spp. in milk. The methods showing the highest detection efficiencies were crystal violet tetrazolium agar (CVTA) pour plates (R(2) = 0.95) and CVTA plates inoculated by spiral plating (R(2) = 0.89) incubated at 32 °C for 48 h. Overall, plating milk samples on CVTA followed by a 48-h incubation at 32 °C was the most effective selective method for recovering a diversity of Pseudomonas spp. from milk.     

Differential roles of frequency and meaningfulness in free recall.

Performed 2 experiments with 91 experimentally naive high school students to study the comparative influence of frequency and meaningfulness (m) on free recall. In Exp. I, the free-recall scores of 3 lists of words matched for m but varying in frequency levels were compared. In Exp. II, free recall of 3 lists of words matched for their frequency but varying in their m values were compared. Findings reveal that it is the frequency and not m of the words that influences free-recall, and that the influence of frequency is noticeable in the early trials of free-recall learning. Findings are discussed in terms of the existing theories of verbal learning. (French summary) (PsycINFO Database Record (c) 2010 APA, all rights reserved)