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This study examined bidirectional associations between cross-racial friendships and children's social and academic adjustment. Participants were 583 elementary school-age children in western Canada, or the midwestern United States (4-10 years; 279 girls; 143 Asian, 88 Black, 65 Hispanic or Latinx, 171 White, 116 mixed). Children's adjustment (social preference, academic enablers, academic performance) and friendship nominations (reciprocated, received, given) were measured in fall and spring over one school year from 2017 to 2018, or from 2018 to 2019. Regarding reciprocated nominations, fall adjustment positively predicted spring reciprocated cross-racial friendships, but not vice-versa. For received nominations, academic enablers and received cross-racial friendship nominations were positively and bidirectionally related to one another. Fall same-racial friendship nominations positively predicted spring academic performance and social preference. Effect sizes were small.

A wheel set bearing is an important supporting component of a high-speed train. Its quality and performance directly determine the overall safety of the train. Therefore, monitoring a wheel set bearing’s conditions for an early fault diagnosis is vital to ensure the safe operation of high-speed trains. However, the collected signals are often contaminated by environmental noise, transmission path, and signal attenuation because of the complexity of high-speed train systems and poor operation conditions, making it difficult to extract the early fault features of the wheel set bearing accurately. Vibration monitoring is most widely used for bearing fault diagnosis, with the acoustic emission (AE) technology emerging as a powerful tool. This article reports a comparison between vibration and AE technology in terms of their applicability for diagnosing naturally degraded wheel set bearings. In addition, a novel fault diagnosis method based on the optimized maximum second-order cyclostationarity blind deconvolution (CYCBD) and chirp Z-transform (CZT) is proposed to diagnose early composite fault defects in a wheel set bearing. The optimization CYCBD is adopted to enhance the fault-induced impact response and eliminate the interference of environmental noise, transmission path, and signal attenuation. CZT is used to improve the frequency resolution and match the fault features accurately under a limited data length condition. Moreover, the efficiency of the proposed method is verified by the simulated bearing signal and the real datasets. The results show that the proposed method is effective in the detection of wheel set bearing faults compared with the minimum entropy deconvolution (MED) and maximum correlated kurtosis deconvolution (MCKD) methods. This research is also the first to compare the effectiveness of applying AE and vibration technologies to diagnose a naturally degraded high-speed train bearing, particularly close to actual line operation conditions.

Inter-rater agreement about children’s symptoms of attention-deficit/hyperactivity disorder (ADHD) is crucial for accurately identifying and treating children with this condition. Decades of empirical research demonstrate that parents and teachers rarely agree about children’s ADHD symptoms, yet few studies have tested the factors that relate to parent-teacher agreement. This exploratory study examined potential associations between parent-teacher agreement about child ADHD symptoms, and child factors (academic functioning, demographic characteristics, externalizing psychopathology, and social functioning), in a community (n = 752; mean age = 7.28; 51.3% male; 46.5% White) and in a clinical (n = 213; mean age = 8.58; 69.0% male; 70.4% White) sample. Agreement was examined using polynomial regression analyses, which overcome mathematical limitations and constraints imposed by using difference scores. Parent-teacher agreement about ADHD symptoms related to several academic and social functioning variables in the community sample. Most relationships were non-linear (e.g., quadratic, cubic). The 3-dimensional distribution of the results revealed that parent-teacher agreement was strongest for children functioning approximately 1 standard deviation below the mean (but not lower) on grades, academic enablers, academic performance, and social functioning. In the clinical sample, only teacher-rated social functioning related to parent-teacher agreement about ADHD symptoms. These findings provide a more nuanced understanding of parent-teacher agreement, thereby advancing theoretical knowledge. An implication for assessment and treatment is that children with very poor, or conversely, very good, social and academic functioning are at risk for parent-teacher disagreement on ADHD symptom ratings.

Acoustic emission (AE) technology is suitable for monitoring the status of high-speed train bearings owing to its high sensitivity and real-time dynamic monitoring capabilities. However, a complete theoretical model of the AE sensor, which is the core component of AE signal sensing equipment, has not yet been reported. The existing matching layer models do not account for wave attenuation in the matching layer. To address these shortcomings, we established a novel piezoelectric AE sensor design and modeling method. First, a rough contact model is established for piezoelectric ceramics, and the influence of roughness on size selection of piezoelectric ceramics is analyzed. Second, the sound intensity transmission coefficient (SITC) model of the matching layer is established considering the attenuation of AE waves, and the corresponding relationship between the attenuation coefficient and the optimum thickness of the matching layer is derived. Then a complete finite element (FE) model of an AE sensor is established, and the electroacoustic properties of the AE sensor are numerically simulated based on acoustic and piezoelectric coupling. Furthermore, AE sensors with different thicknesses of matching layers are constructed, and the validity of the mathematical model of the matching layer is verified through a lead-breaking experiment. Thereafter, a novel comprehensive performance evaluation index (CPEI) is designed through principal component analysis (PCA) based on hit parameters of AE sensors. Finally, the effectiveness and environmental adaptability of the AE sensor is verified by performance testing under complex conditions near an actual high-speed train line. The proposed method can provide a valuable theoretical framework for AE sensor design and status monitoring of high-speed train bearings.

In this paper, three liquids flowing in five pipes with the same inner diameter of 14 mm were studied to determine the relationship between the surface wettability and flow properties in laminar flow (Re

Despite the numerous studies on bearing fault diagnosis based on frequency domain or time-frequency domain analyses, there is a lack of a fair assessment on which method or methods are practically effective in identifying the fault frequencies of damaged bearings in noisy environments. Most methods were developed based on experiments with simple lab test rigs equipped with bearings having manufactured artificial defects, and the signal-to-noise ratio under lab conditions is too ideal to be useful for verifying the effectiveness of a signal processing method. The purpose of this study is to evaluate the effectiveness of advanced signal processing methods applied in a high-speed train operating environment with multi-source interference. In this work, the most advanced signal processing methods (including spectral kurtosis, deconvolution, and mode decomposition) are studied, and the shortcomings of each method are analyzed. Based on the characteristics of high-speed train wheel set bearings (HSTWSBs), the concept of fault characteristic signal-to-noise ratio (FCSNR) is put forward to quantitatively evaluate the fault periodicity intensity, and corresponding improved methods are proposed by combining the FCSNR with existing signal processing methods; all these methods consider the periodic characteristics and impact characteristics of the bearing fault. The simulation signal and actual signals of HSTWSB with natural defects help verify the effectiveness of the proposed methods. Finally, the advantages and disadvantages of the different signal processing methods are objectively evaluated, and the application scope of each method is analyzed and prospected. This study provides a reference and new ideas for the fault diagnosis of HSTWSB and other industrial bearings.

As fundamental software of high-performance computers, elementary functions have a significant impact on the performance of the high-level applications. Benefiting from the Chinese-designed manycore system consisting of processing cores and auxiliary cores, the Sunway TaihuLight supercomputer is considered as one of the fastest supercomputers in the world, having ranked on the top of the TOP500 supercomputer list several times. The processing cores of the Sunway architecture are coupled using a shared memory strategy, leading to high latency of memory accesses and performance degradation of the elementary functions where a variety of memory accesses exist. To address this issue, we propose a set of optimizations for memory latency of the Sunway processing cores. Firstly, we obtain a reduced data table in the context of guaranteed accuracy by optimizing underlying algorithms, grouping and mapping, removing error compensations, etc. Secondly, we perform data movement from the global memory shared by all processing cores to the scratchpad memory of individual processing cores, significantly reducing the memory latency. Finally, we convert the memory accesses that cannot be localized due to the limited space of the scratchpad memory into equivalent immediate loads and/or shift operators, further improving the performance. In addition, we automate the algorithm by carefully selecting the most suitable data conversion approach and table-lookup algorithm, mitigating the code explosion issue effectively. We implement our method and evaluate the effectiveness of the optimizations by conducting experiments on the Sunway architecture. The experimental results show that exponential functions can achieve performance improvements by 91 and 86.2% from the data movement and data conversion strategies.

Establishing a positive peer climate in elementary school classrooms is an important goal for educators because peer dynamics are thought to affect academic learning. Thus, it is important to (a) understand the relationship between children's peer dynamics and academic functioning, and (b) identify teacher practices that influence both peer processes and academic outcomes. In this pilot study, we explored whether specific teacher strategies that promote positive behaviors in children and positive peer dynamics influence children's better academic enablers, as well as whether they do so indirectly via improving peer sociometric ratings. Such teacher strategies may be particularly relevant for supporting children who demonstrate impairment in both social and academic domains, such as children at risk for attention-deficit/hyperactivity disorder (ADHD). Thus, we also examined whether these relationships differ for children with elevated ADHD symptoms and peer problems (i.e., target students), relative to classmates (i.e., non-target students). Participants were 194 children in the classrooms of 12 teachers (grades K-4) who participated in an open-trial pilot study of the school-based version of the Making Socially Accepting Inclusive Classrooms (MOSAIC) program. In the fall and spring of a school year, we assessed children's sociometric ratings received from peers, and academic enabler skills as rated by teachers. Throughout one academic year, we obtained assessments of teachers' use of MOSAIC strategies (observed and self-reported). Results showed that, after accounting for fall academic enablers, the teacher strategy of CARE time (involving one-on-one interaction with the student to build the teacher-student relationship) was positively associated with spring academic enablers. However, findings did not support the hypothesized indirect effect of peer sociometric ratings on the relationship between teacher strategy use and academic enablers, or the moderated indirect effect by target student status. Implications for future research and classroom interventions are discussed.

Culture shapes children's memories. However, scant attention has been given to the influence of culture on specific memory stages. Thus, we conducted two controlled experiments to examine cultural differences in memory recall at immediate and delayed retrieval phases. In Studies 1 and 2 (n = 217), 7- to 10-year-old Chinese and Euro-Canadian children watched a story involving both social- and individual-focused scenarios. Participants then recalled the story immediately afterwards (Study 1) and 5-7 days later (Studies 1 and 2). Findings reveal that Chinese children accurately reported more details from the social-focused events than did their Euro-Canadian counterparts in the immediate interview, and this result was replicated after a delay in both studies. Moreover, as expected, within-country comparisons showed that Euro-Canadian children had better memory for individual- than for social-focused events in both studies. Chinese children, however, showed better memory for social- than for individual-focused events only in the immediate interview in Study 1; their delayed retrieval was not affected by event focus. These findings reveal that cultural variations in memory are evident in both immediate and delayed retrieval. Implications for future research are discussed.

Floating-point error is one of the important factors that limit the accuracy of calculation. Programs using floating-point numbers are prone to accuracy problems by rounding and catastrophic cancelation. Mathematical library is an essential part of computer system. Its implementation is a common genre of floating-point calculation. Implementing these functions through polynomial expansion has algorithmic error in addition to rounding and catastrophic cancelation. Furthermore, ‘concise’ mathematical functions are frequently developed for applications with high-performance requirements. These ‘concise’ functions pay more attention to performance rather than accuracy. As a result, serious accuracy problems might occur, which will further affect the execution of programs. In this paper, a heuristic approach is designed to detect the maximum error of mathematical functions. It is theoretically proved in Sect. 2 that the maximum error of the mathematical functions generally occurs in small intervals. This finding is further proved by several experiments. The heuristic approach is designed based on it. Firstly, the large-scale test is used to gain the error distribution of functions. After that, the intervals, where the maximum error may occur (called ‘tingle intervals’ in this paper), are derived from the error distribution. At last, the high coverage test over tingle intervals is used to detect the maximum error. We evaluate the algorithm by analyzing mainstream math libraries (MKL, Glibc and Sunway TaihuLight). Our experiments show the approach can correctly deal with over 96.2% of mathematical functions. The approach designed in this paper has been used in the analysis and optimization of Sunway TaihuLight Math Library.

Memory is socially constructed. The types of information that children pay attention to and remember, as well as how children organize and recall their memories can differ as a function of sociocultural background. This chapter presents an overview of cultural variations on children's memory and cognition. We draw attention to the necessity of conducting controlled experiments to examine cultural differences in the specific processes involved in episodic memory (e.g., encoding, retention, discrimination skills). We highlight potential challenges (e.g., language, measurement equivalence) that researchers need to overcome to conduct valid cross-cultural research. In light of cultural transformations in recent decades, we outline promising avenues for future research as well as the applications of this research to important issues for forensics and immigrants and asylum-seekers.

A substantial portion of immigrants to Canada comes from East Asia (e.g., Mainland China, Taiwan, Hong Kong, and Korea). In this article, we discuss how culture shapes the way that children recall autobiographical events, how language differences can affect prosecutions of child sexual abuse, and why cultural differences (between East Asia and North America) may affect the likelihood that children disclose abuse. These three factors closely interplay with each other, which can lead child abuse victims who are from East Asian cultures to be underrepresented and disadvantaged in the Canadian legal system.In this article, we discuss the severe consequences that may face East Asian immigrant families when their children try to disclose alleged sexual abuse. In particular, we refer to Mandarin Chinese speakers. We first discuss the role of children in investigations of abuse in Canada and then outline some cultural differences between Euro-Canadian and Asian cultures. We then present our argument about how cultural and language differences may impact the investigation and prosecution of abuse.Child sexual abuse investigations can take place in two ways: Children could directly voice the allegations (known as disclosure) or a concerned adult might suspect abuse and report it to authorities. In both Canada and the United States, there is mandatory reporting of abuse (i.e., adults must report suspected abuse to the authorities or risk being "accessories" to the abuse). A common sequence of events after a disclosure/suspicion of abuse is for the relevant child welfare and legal authorities to proceed with an investigation to determine, first, if the child is in imminent danger and, second, whether there is information of sufficient quality to proceed with an investigation (Brubacher, Bala, Roberts, & Price, 2016). Although there are sometimes witnesses who can give first-hand accounts, sexual abuse often takes place in private and so the only testimony can come from the child and/or the perpetrator. Suspected perpetrators commonly deny the abuse unless there is a credible, quality statement from the alleged victim (Pipe, Orbach, Lamb, Abbott, & Stewart, 2013). Thus, what children say in investigative (forensic) interviews is critical to decisions about whether to prosecute or not.It is our argument that East Asian immigrant children are particularly disadvantaged and, potentially, at-risk, compared to Westernized children. As illustrated in Figure 1, we focus specifically on three areas of concern: (1) cultural differences that can shape children's memory recall, (2) cultural differences that can impact the path of disclosure of sexual abuse, and (3) language differences which reduce the chances that perpetrators will be prosecuted for sexual abuse. Before discussing these cultural differences, we outline the role of memory in a forensic interview given the importance of children's role as victim witnesses. This provides the reader with a clear idea of what is involved in Canadian investigations of child abuse.Children's Memory and the Forensic InterviewGood forensic interviewers allow children to freely recall what happened to them. This means that children are free to choose what information they report. There are no hints or suggestions at this stage as to what sort of details are needed. When we recall, one memory reminds us of another memory and so on. In more visual terms, picture a web of neuronal pathways each connected to another. Each pathway produces a memory and links to the next piece of information. Thus, we can recall many details about an experienced event.Recalling memories requires a larger cognitive load than recognizing pieces of information. An interviewer who asks, "Was your mum there?" is asking the child to recognize whether mum was present. Although recognition is easier than recall, it is not a forensically valid technique in child sexual abuse interviews. By describing a piece of information, the interviewer is suggesting information that may or may not be true. …

A laboratory study was conducted to remediate petroleum contaminated soils using microwave irradiation, and the traditional method of electric heating was also used for comparison purpose. The feasibility of the microwave irradiation method was evaluated in aspects of the reaction time, petroleum removal efficiency and energy consumption level. Meanwhile, the impacts of microwave irradiation mode and soil conditions on petroleum removal efficiency were also investigated, with a thermodynamic model of soils specifically developed. The results showed that microwave irradiation was better than the traditional heating method in remediating petroleum contaminated soils with less energy consumed. Also, microwave irradiation time, microwave power, soil moisture content and soil petroleum content had all imposed significant impacts on the remediation efficiency, and the results obtained from the model were basically consistent with the experiment results. Therefore, the findings from this study are of significance in real-world applications of microwave irradiation for the remediation of petroleum contaminated soils.

In order to solve the problem of back pressure set unreasonable in direct air-cooling unit, a back-pressure-fuzzy-inference machine is established in this paper, of which the environmental temperature and wind speed are the inputs, and the optimal back pressure is the output. The feasibility of the novel method is verified by simulation and experimental results, and the accuracy of back pressure fuzzy prediction can satisfy the operating requirements.