A general material removal strategy based on surface sampling and reconstruction on unknown objects

In most material removal processes, the size and shape of the stock material, the desired surface and the orientation of the part are known. If some or all of these factors are unknown, typical automatic systems will not be able to handle the situation. In reality, most of these cases are subsequently handled by human operators. This results in low productivity and inconsistency in the production and potential ergonomic problems for the human operators. Therefore, a new system needs to be designed to meet the requirements for material removal with unknown objects.;This dissertation presents a feasible and efficient automatic system for material removal with unknown processing factors. The characteristics of this type of processes were investigated. The corresponding inputs of the system were decided, while balancing the ease of use and the complexity of the system. A simple point sampling strategy was developed to sample the reference points, which are used to create the approximated surface for the unknown objects with a modified triangular based surface approximation method. A universal layer based path planning method was developed to guide the tool among the layers within the designated working area to remove the excess material effectively and efficiently without changing the programming codes.;This system was verified by simulations and a prototype of the grinding system

Intraday volatility analysis of CSI 300 index futures: a dependent functional data method

This study introduces a new volatility model based on dependent functional data to investigate the intraday volatility characteristics of CSI 300 in the context of high-frequency data. The volatility curve is fitted and reconstructed using three methods: functional principal component analysis, Newey-West kernel, and truncationfree Bartlett kernel. We adopt a functional time series approach for short-term dynamic forecasting. The empirical results show that the proposed dependent functional volatility estimation model based on the long-term covariance of the truncated Bartlett kernel can accurately capture the intraday volatility trajectory and outperforms other models in terms of forecast accuracy and profitability. This study improves the volatility-related research methodology, which is conducive to discovering the price formation mechanism of the stock index futures market and improving risk management capabilities

Factors Affecting Users\u27 Dynamic Message Deleting Intention on Social Networks: An Empirical Study Based on Impression Management Theory

Social dynamics is a social networking service that allows users to input updates including letters, pictures, videos and share them with their social friends. Previous research mainly focus on the application of dynamic messages in the fields of communication science and economics. Based on impression management theory, this paper studies the influencing factors of users\u27 dynamic message deleting intention on social networks. The results show that impression management performance and social network fatigue significantly affect user\u27s intention to delete the dynamic messages. While message sender factors, such as self-monitoring, interpersonal interaction and image promotion; social platform factors such as information overload and social overload, indirectly influence the deleting intention through intermediary variables. This paper makes up for the lack of relevant empirical research, making users more social flexibility and effectiveness, thereby enhancing social validity, and have some practical implications for social networking services platforms

China’s Regional Innovation Environment Evaluation

On the base of monitoring China’s regional environmental quality and analyzing soft power of innovation environment, the authors make a comprehensive evaluation on China’s 31 provinces’ regional innovation environment in four levels: basic environment, organizational environment, cultural environment and information environment. The study shows that the innovation environment in East Coast is the best; the Central and Northeastern regions are moderate; while the innovation environment of the West is worse than the other three regions. Also, the policy recommendations to enhance innovation environment quality of the West have been proposed

Impact of authentic leadership on performance: Role of followers’ positive psychological capital and relational processes

Authentic leadership has received considerable attention and research support over the past decade. Now the time has come to refine and better understand how it impacts performance. This study investigates the moderating role followers’ positive psychological capital (PsyCap) and the mediating role that leader–member exchange (LMX) may play in influencing the relationship between authentic leadership and followers’ performance. Specifically, we tested this mediated moderation model with matched data from 794 followers and their immediate leaders. We found that authentic leadership is positively related to LMX and consequently followers’ performance, and to a larger degree, among followers who have low rather than high levels of PsyCap. Our discussion highlights the benefits of understanding the roles of relational processes and followers’ positive psychological resources involved in the effectiveness of authentic leadership and how they can be practically implemented

Coping with newcomer “hangover”: how socialization tactics affect declining job satisfaction during early employment

New entrants to a job often experience a “hangover effect,” whereby their job satisfaction declines as they become familiar with the job. Socialization scholars thus have sought to identify ways to forestall or ameliorate such declines. Recently, Boswell, Shipp, Payne, and Culbertson (2009) found that the extent of socialization can exacerbate the hangover effect. Following up this provocative finding, this study investigated whether socialization tactics worsen or dampen the hangover effect and by so doing, affect newcomer attrition. We monitored how newcomers' job satisfaction changed over time by surveying them on four occasions during the first six months of employment. We observed that socialization tactics (especially context and social tactics) increase the rate of declining job satisfaction during early employment. Yet all three tactics decrease this descent rate when enacted at high levels. Moreover, the present research established that declining job satisfaction translates into a trajectory of increasing turnover intentions and thus higher quits. Further, we found that extremely high social tactics can actually suppress the hangover effect and thereby reduce newcomer attrition. Our dynamic research offered a more nuanced understanding of how socialization tactics influence the hangover effect and newcomer attrition

Condensin Promotes Position Effects within Tandem DNA Repeats via the RITS Complex

SummaryTandem repetitive DNA is highly abundant in eukaryotic genomes and contributes to transcription control and genome stability. However, how the individual sequences within tandem repeats behave remains largely unknown. Here we develop a collection of fission yeast strains with a reporter gene inserted at different units in a tandem repeat array. We show that, contrary to what is usually assumed, transcriptional silencing and replication timing among the individual repeats differ significantly. RNAi-mediated H3K9 methylation is essential for the silencing position effect. A short hairpin RNA of ura4+ induces silencing in trans within the tandem array in a position-dependent manner. Importantly, the position effect depends on the condensin subunit, cut3+. Cut3 promotes the position effect via interaction with the RNA-induced transcriptional silencing (RITS) complex. This study reveals variations in silencing within tandem DNA repeats and provides mechanistic insights into how DNA repeats at the individual level are regulated