Constant turning force operation with a fixed metal removal rate via a prior fuzzy controller system

This study examines constant metal removal rate (MRR) with constant turning force (CTF) that operates by means of a prior fuzzy controller (PFC) that is able to automatically manipulate the spindle speed to maintain the MRR at a specified suitable value. Fuzzy-control techniques and grey theory are integrated to integrate a PFC into the constant turning force operation. The most important difference between the PFC and conventional fuzzy controller (FC) is that the fuzzy control signal is determined by the future predicted-state value obtained by a grey model instead of by the present-state value used in the traditional fuzzy controller (FC). Hence, the control signal can be obtained in advance and ensure the safety of the system. This study adopts an auxiliary fixed metal removal rate (MRR) controller, which can respond to the lathe power, machining roughness or tool chatter, and which in constant turning force (CTF) operations is adopted because when the controlled system is a non-linear function, as F_c = aK_ff^p, the productivity will always decrease. With the exponential function, the increase in cutting depth a will entail decrease in the feed f, thus reducing the metal removal rate (MRR), which is defined as MRR = afV_c (mm³ s⁻¹). A suitable solution is to increase the cutting speed V_c (mm s⁻¹). Consequently, the concept of the MRR is built into the auxiliary controller to improve the CTF control system.     

一种基于图割的图像去雾方法

暗原色先验去雾方法在户外场景图像去雾方面取得了一定的去雾效果,但该方法在估计近景局部高亮物体透射率时会产生严重误差。本文针对暗原色先验方法的不足首先利用图割理论对粗透射率图进行分块,并使用指导滤波器对细化透射率图进行校正,最后将校正的透射率图带入有雾图像成像模型求得清晰无雾图像。通过将基于暗原色先验的方法、局部对比度最大化的方法和本文中的改进方法进行了实验并对实验结果进行了分析,结果表明本文中的图割分块校正透射率的方法能够更有效地复原因雾霾影响的单幅降质图像。     

Improving learning from animated soccer scenes: Evidence for the expertise reversal effect

In two experiments, we investigated how animation of play (soccer) should be designed in order to avoid the high cognitive load due to the fleeting nature of information. Using static pictures and altering the animation’s presentation speed have been proposed as instructional strategies to reduce learners’ cognitive load. In the first experiment, we tested the effect of static vs. animated presentations on learning. The results indicated that novices benefited more from the static presentation whereas experts benefited more from the animated presentation. The second experiment investigated the effect of low vs. normal vs. high levels of presentation speed on learning. The results showed that novices profited more from the low presentation speed while experts profited more from the normal and high presentation speeds. Thus both experiments demonstrated the occurrences of the expertise reversal effect. Findings suggest that the effectiveness of instructional strategies depends on levels of soccer players’ expertise.     

Dealing with conflicting information from multiple nonlinear texts: Effects of prior attitudes

This study investigated the effects of prior attitudes on how students deal with conflicting information in multiple nonlinear texts. Sixty-one Dutch 11th grade students read multiple texts on a controversial topic and wrote a short essay on it. These essays were scored on perspective taken and the origin of information included in them. Ordinal regression analysis showed that students with strong prior attitudes were significantly more likely to write essays that were biased towards their prior attitudes. Furthermore, multiple regression analyses revealed that students with strong attitudes took explicit stances and added large proportions of information not presented in the reading materials in their essays, whereas students with neutral attitudes wrote syntheses and borrowed more information from the materials. Overall, results show that prior attitudes can bias how students deal with conflicting information in an open-ended reading and writing task.     

Effects of prior damage on the creep failure behaviour of similar and dissimilar welded CrMoV main steam pipes incorporating a partial repair

Creep damage finite element analyses, with the inclusion of “prior damage”, were performed for partially-repaired circumferential welds in a thick-walled, main steam, CrMoV pipe. The repair consists of aged parent material, weld metal and one HAZ region being partially excavated and replaced by new weld metal. The pipe welds were subjected to realistic internal pressure and uniform axial loading, the magnitude of the latter being up to that allowed by design codes. The material properties used are related to those of a CrMoV weldment at 640 °C. It is assumed that a full post-weld heat treatment has been carried out and that the effects of welding induced residual stresses reduce to negligible levels. The results obtained are used to examine the subsequent performance for “similar” and “dissimilar” welds with a range of “repair times” (defined as prior damage levels), magnitudes of axial (system) load, etc. From these results, the failure behaviour of this particular partial repair case was evaluated and discussed.     

Visual impact assessment of offshore wind farms and prior experience

Energy planners have shifted their attention towards offshore wind power generation and the decision is supported by the public in general, which in the literature has a positive attitude towards offshore wind generation. However, globally only a few offshore wind farms are operating. As more wind farms start operating and more people become experienced with especially the visual impacts from offshore wind farms, the public positive attitude could change if the experienced impacts are different from the initially perceived visual interference. Using a binary logit model, the present paper investigates the relation between different levels of prior experience with visual disamenities from offshore wind farms and perception of visual impacts from offshore wind farms. The differences in prior experience are systematically controlled for sampling respondents living in the areas close to the large scale offshore wind farms Nysted and Horns Rev and by sampling the a group of respondents representing the Danish population, which has little experience with offshore wind farms. Compared to previous results in the literature, the present paper finds that perception of wind power generation is influenced by prior experience. More specifically, the results show that people with experience from offshore wind farms located far from the coast have a significant more positive perception of the visual impacts from offshore wind farms than people with experience from wind farms located closer to the coast. These results are noteworthy on two levels. First of all, the results show that perceptions of offshore wind generation are systematically significantly influenced by prior experience with offshore wind farms. Secondly, and in a policy context, the results indicate that the future acceptance of future offshore wind farms is not independent of the location of existing and new offshore wind farms. This poses for caution in relation to locating offshore wind farms too close to the coast.     

Reliability estimation by Bayesian method: definition of prior distribution using dependability study

In this article, we present an evaluation method of the system reliability using Bayesian statistics and data feedback. In particular, we deal with the problem of the prior definition. A method is proposed to build the prior distribution from the dependability study (risk evaluation study).     

Post-adoption behavior of users of Internet Service Providers

We examined post-adoption behavior in the Internet Service Provider (ISP) industry and found that the needs of service continuers and service discontinuers are different and customers who discontinue generally do so in the first six months. Also, business customers are less likely to discontinue than are personal users and, while prior behavior is a powerful predictor of future behavior, socio-demographic characteristics are weak predictors. We generated a combined model, which accurately predicted 82.6% of customer choices to continue or discontinue. The findings have important implications for both theory development and practice.     

Robust specification of the roughness penalty prior distribution in spatially adaptive Bayesian P-splines models

The potential important role of the prior distribution of the roughness penalty parameter in the resulting smoothness of Bayesian P-splines models is considered. The recommended specification for that distribution yields models that can lack flexibility in specific circumstances. In such instances, these are shown to correspond to a frequentist P-splines model with a predefined and severe roughness penalty parameter, an obviously undesirable feature. It is shown that the specification of a hyperprior distribution for one parameter of that prior distribution provides the desired flexibility. Alternatively, a mixture prior can also be used. An extension of these two models by enabling adaptive penalties is provided. The posterior of all the proposed models can be quickly explored using the convenient Gibbs sampler.     

Centenary of the enactment of the United Kingdom’s Patents and Designs Act 1907

The UK Patents and Designs Act 1907 was especially significant in the historical development of the patent system in the UK. The article notes that the Act repealed all previous legislation, except the Statute of Monopolies of 1623. It introduced new provisions for adequacy of disclosure (e.g. the power to require samples in support of chemical patent applications), prior claiming, term extension in cases of proven inadequate remuneration, compulsory licences or revocation in cases of non-working in the UK, innocent infringement, and Crown use. The author provides much information on the passage of the Bill that became this Act, including the politics and personalities associated with the Act and the problems giving rise to the changes.