With the development of intelligent manufacturing, more and more nonstandard parts are used in high-precision assembly. The robotic assembly method based on attractive region in environment (ARIE) has been proven to have good performance in the high-precision assembly under the limitation of robot system accuracy or sensing accuracy. However, for the assembly of nonstandard parts, especially nonconvex parts, the existing ARIE-based strategy lacks a targeted design. In the assembly process, the nonconvex structure may cause blocking problems, which will lead to assembly failure when using the strategy. In order to solve this problem, this paper proposes a new assembly method by using the geometric features of constraint region based on the concept of ARIE. Specifically, first, when using the ARIE-based classic strategy, the reasons for the possible blocking problem in the assembly of a class of nonconvex axisymmetric parts are analyzed in detail. Second, a multi-step sliding strategy is proposed based on the theory of ARIE to solve the possible blocking problem in the assembly process. Third, impedance control is used to enable the peg to achieve the desired compliant motion in the proposed strategy. The improvement in the success rate of the proposed method is verified by the comparison experiment of small clearance peg-in-hole assembly, where the structure of the peg is nonconvex and axisymmetric.

In this paper, we explore potential surplus modelling improvements by investigating how well the available models describe an insurance risk process. To this end, we obtain and analyse a real-life data set that is provided by an anonymous insurer. Based on our analysis, we discover that both the purchasing process and the corresponding claim process have seasonal fluctuations. Some special events, such as public holidays, also have impact on these processes. In the existing literature, the seasonality is often stressed in the claim process, while the cash inflow usually assumes simple forms. We further suggest a possible way of modelling the dependence between these two processes. A preliminary analysis of the impact of these patterns on the surplus process is also conducted. As a result, we propose a surplus process model which utilises a non-homogeneous Poisson process for premium counts and a Cox process for claim counts that reflect the specific features of the data.

The study examined how learners’ motivational dispositions predict the complexity, accuracy, fluency of their oral task performance and their overall second language proficiency. Eighty-one speakers of English as a second language in the United States completed a regulatory focus and a regulatory mode questionnaire, an oral interview task, and a picture description task. Regression analyses showed a meaningful pattern of results. The assessment mode (concerned with analysis, evaluation, and comparison) contributed to syntactic and lexical complexity, the reduction of dysfluencies, and overall English proficiency, whereas the locomotion mode (concerned with acting without deliberation) positively predicted the speed measure of fluency and the total number of errors. The prevention focus (concerned with stability, security, and safety) negatively predicted lexical sophistication, whereas the promotion focus (concerned with advancement, accomplishments, and growth) predicted overall English proficiency. Theoretical and instructional implications were discussed.

A simple process for the design of broadband planar antennas is presented for base station applications. The process is based on a square patch above a ground plane. Only three geometric parameters are involved in the design of a dual-polarized broadband planar antenna, including the width (Ws) of the square patch, a trimming angle (θ) of the square, and the height (H) of the patch above the ground plane. By adjusting the critical parameters θ and H, an impedance bandwidth of 50% for return loss (RL) >15 dB is achieved with an isolation of higher than 35 dB. The bandwidth of the broadband planar antenna is enhanced to 67% by etching four Γ slots on the square patch. The operating mechanisms of these broadband antennas are analyzed and verified by simulation and experiment.

In this study, we built on our previous research that discovered that autophagy activated the metaphase I stage during porcine oocytes in vitro maturation. We investigated the relationship between autophagy and oocyte maturation. First, we confirmed whether autophagy was activated differently by different media (TCM199 and NCSU-23) during maturation. Then, we investigated whether oocyte maturation affected autophagic activation. In addition, we examined whether the inhibition of autophagy affected the nuclear maturation rate of porcine oocytes. As for the main experiment, we measured LC3-II levels using western blotting after inhibition of nuclear maturation via cAMP treatment in an in vitro culture to clarify whether nuclear maturation affected autophagy. After autophagy inhibition, we also counted matured oocytes by treating them with wortmannin or a E64d and pepstatin A mixture. Both groups, which had different treatment times of cAMP, showed the same levels of LC3-II, while the maturation rates were about four times higher after cAMP 22 h treatment than that of the 42 h treatment group. This indicated that neither cAMP nor nuclear status affected autophagy. Autophagy inhibition during in vitro oocyte maturation with wortmannin treatment reduced oocyte maturation rates by about half, while autophagy inhibition by the E64d and pepstatin A mixture treatment did not significantly affect the oocyte maturation. Therefore, wortmannin itself, or the autophagy induction step, but not the degradation step, is involved in the oocyte maturation of porcine oocytes. Overall, we propose that oocyte maturation does not stand upstream of autophagy activation, but autophagy may exist upstream of oocyte maturation.

Convective dissolution is an important mechanism for long-term CO$_2$ sequestration in deep saline aquifers. The presence of an unstable geothermal gradient can affect the process of dissolution. In this paper, we present direct numerical simulations in a three-dimensional porous medium at three different concentration Rayleigh numbers $Ra_S$ with a set of thermal Rayleigh numbers $Ra_T$. Simulations reveal that the flow structures alter when ${\textit {Ra}}_T$ increases for a fixed ${\textit {Ra}}_S$. Strong thermal gradient can yield large-scale convection rolls which change the horizontal distribution and motions of concentration fingers. The time evolution of fluxes also has different responses to different ${\textit {Ra}}_T$. A theoretical model is developed and successfully describes the evolution of concentration flux and volume averaged concentration during the final shutdown stage. We further calculate the dissolved CO$_2$ into the interior over time, which shows non-monotonic variations as ${\textit {Ra}}_T$ increases. At the end of our simulations, the maximum increment of dissolved CO$_2$ occurs when density ratio is around unity for all three concentration Rayleigh numbers we have explored. We apply our results to a typical geological reservoir and discuss their implications.

We propose a test for anticipated changes in spot volatility, either due to continuous or discontinuous price moves, at the times of realization of event risk in the form of pre-scheduled releases of economic information such as earnings announcements by firms and macroeconomic news announcements. These events can generate nontrivial volatility in asset returns, which does not scale even locally in time. Our test is based on short-dated options written on an underlying asset subject to event risk, which takes place after the options’ observation time and prior to or after their expiration. We use options with different tenors to estimate the conditional (risk-neutral) characteristic functions of the underlying asset log-returns over the horizons of the options. Using these estimates and a relationship between the conditional characteristic functions with three different tenors, which holds true if and only if continuous and discontinuous spot volatility does not change at the event time, we design a test for this hypothesis. In an empirical application, we study anticipated individual stocks’ volatility changes following earnings announcements for a set of stocks with good option coverage.

This article concentrates on four Chinese blockbuster movies, Wolf Warrior (2015), Operation Mekong (2016), Wolf Warrior 2 (2017) and Operation Red Sea (2018), referring to them collectively as the “wolf warrior cycle” on the basis of their shared themes of China's overseas military actions. To understand why films addressing this topic have emerged since the mid-2010s, the article employs a critical political economy approach and situates the wolf warrior cycle in China's transforming foreign policies. It argues that the Belt and Road Initiative, one of the state's prominent foreign policies and global strategies in this period, played a crucial role in shaping the production of the wolf warrior cycle films under a trend of the politicization of commercial blockbusters in the Chinese film industry. In turn, these films contributed to the formation of the “wolf warrior diplomacy” image by reinforcing the proactiveness of China's diplomacy and nationalistic stereotypes in Chinese society towards international relations.

Pb–Zr–Ti–O (PZT) perovskites span a large solid-solution range and have found widespread use due to their piezoelectric and ferroelectric properties that also span a large range. Crystal structure analysis via Rietveld refinement facilitates materials analysis via the extraction of the structural parameters. These parameters, often obtained as a function of an additional dimension (e.g., pressure), can help to diagnose materials response within a use environment. Often referred to as “in-situ” studies, these experiments provide an abundance of data. Viewing structural changes due to applied pressure conditions can give much-needed insight into materials performance. However, challenges exist for viewing/presenting results when the details are inherently three-dimensional (3D) in nature. For PZT perovskites, the use of polyhedra (e.g., Zr/Ti–O6 octahedra) to view bonding/connectivity is beneficial; however, the visualization of the octahedra behavior with pressure dependence is less easily demonstrated due to the complexity of the added pressure dimension. We present a more intuitive visualization by projecting structural data into virtual reality (VR). We employ previously published structural data for Pb0.99(Zr0.95Ti0.05)0.98Nb0.02O3 as an exemplar for VR visualization of the PZT R3c crystal structure between ambient and 0.62 GPa pressure. This is accomplished via our in-house CAD2VR™ software platform and the new CrystalVR plugin. The use of the VR environment enables a more intuitive viewing experience, while enabling on-the-fly evaluation of crystal data, to form a detailed and comprehensive understanding of in-situ datasets. Discussion of methodology and tools for viewing are given, along with how recording results in video form can enable the viewing experience.

In masked priming lexical decision tasks in alphabetic or syllabic script languages, latencies are longer when a word target is primed by a higher frequency neighbor (e.g., blue–BLUR) than when primed by an unrelated word of equivalent frequency (e.g., care–BLUR) – an “inhibitory neighbor priming effect.” In contrast, Zhou et al. (1999) demonstrated facilitatory orthographic neighbor priming for two-character Chinese words (e.g., 华丽–华贵). However, Zhou et al. did not control for relative prime-target frequency, which has been shown to be important in experiments when examining languages with other scripts. In the present Experiment 1 word neighbor primes (e.g., 容易-容貌) produced an inhibitory neighbor priming effect when the prime was higher frequency than the target, paralleling effects in other script languages. In further experiments, paralleling those in other script languages, two-character targets primed by nonword neighbors (容待-容貌) or single constituent characters matching the target in either position (容-容貌) showed significant facilitation. These results suggest that lexical activation/competition processes for two-character Chinese words are reasonably similar to those for words in alphabetic/syllabic script languages.

This study aimed to screen factors related to live birth outcomes of women with first frozen embryo transfer (FET). The enrolled women were divided into training and validation cohorts. The least absolute shrinkage and selection operator (Lasso) regression algorithm of machine learning and the multiple regression model were then used to screen factors relevant to live birth failure (LBF) for the training dataset. A nomogram risk prediction model was established on the basis of the screened factors, and the consistency index (C-index) and calibration curve were derived for evaluating the model. The validation cohort was utilized to validate the nomogram model further. In total, 2083 women who accepted the first FET in our hospital were included and 44 factors were initially screened in this study. On the basis of the training cohort, the screened risk factors via multiple regression analysis with odds ratio (OR) values were female age (OR: 3.092, 95%CI: 1.065–4.852), body mass index (BMI; OR: 1.106, 95%CI: 1.015–1.546), caesarean section (OR: 1.909, 95%CI: 1.318–2.814), number of high-quality embryos (OR: 0.698, 95%CI: 0.599–0.812), and endometrial thickness (OR: 0.957, CI: 0.904–0.980). The nomogram model was generated based on five predictors. Furthermore, favourable results with C-indexes and calibration curves close to ideal curves indicated the accurate predictive ability of the nomogram. Female age, BMI, caesarean section, number of high-quality embryos, and endometrial thickness were independent predictors for LBF. The five factors of the risk assessment model may help to identify LBF with high accuracy in women who accept FET.

Motivated by traffic congestion and air pollution, Beijing is one of several major cities to restrict vehicle ownership by requiring residents to win a lottery for the right to obtain an additional car. We examine the welfare cost of preventing people from owning cars because of misallocation: under a lottery, some individuals with low willingness to pay (WTP) for cars can obtain cars, while other individuals with high WTP cannot. We estimate welfare costs using a new contingent valuation method survey of Beijing lottery participants which we designed and conducted explicitly for this purpose. We find that restricting vehicle ownership reduced private welfare by 26 billion yuan. Back-of-the-envelope calculations suggest that the benefits of lower congestion and pollution roughly equal the costs. Our WTP estimates indicate a net welfare gain of approximately 32 billion yuan if Beijing’s lottery were replaced with an auction, which is similar to previous estimates.