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Objective. This study aims to develop a fully automatic planning framework for functional lung avoidance radiotherapy (AP-FLART). Approach. The AP-FLART integrates a dosimetric score-based beam angle selection method and a meta-optimization-based plan optimization method, both of which incorporate lung function information to guide dose redirection from high functional lung (HFL) to low functional lung (LFL). It is applicable to both contour-based FLART (cFLART) and voxel-based FLART (vFLART) optimization options. A cohort of 18 lung cancer patient cases underwent planning-CT and SPECT perfusion scans were collected. AP-FLART was applied to generate conventional RT (ConvRT), cFLART, and vFLART plans for all cases. We compared automatic against manual ConvRT plans as well as automatic ConvRT against FLART plans, to evaluate the effectiveness of AP-FLART. Ablation studies were performed to evaluate the contribution of function-guided beam angle selection and plan optimization to dose redirection. Main results. Automatic ConvRT plans generated by AP-FLART exhibited similar quality compared to manual counterparts. Furthermore, compared to automatic ConvRT plans, HFL mean dose, V 20, and V 5 were significantly reduced by 1.13 Gy (p <.001), 2.01% (p <.001), and 6.66% (p <.001) respectively for cFLART plans. Besides, vFLART plans showed a decrease in lung functionally weighted mean dose by 0.64 Gy (p <.01), fV 20 by 0.90% (p = 0.099), and fV 5 by 5.07% (p <.01) respectively. Though inferior conformity was observed, all dose constraints were well satisfied. The ablation study results indicated that both function-guided beam angle selection and plan optimization significantly contributed to dose redirection. Significance. AP-FLART can effectively redirect doses from HFL to LFL without severely degrading conventional dose metrics, producing high-quality FLART plans. It has the potential to advance the research and clinical application of FLART by providing labor-free, consistent, and high-quality plans. [ABSTRACT FROM AUTHOR]

Frequent changes in economic policy pose challenges to normal business production and operations. However, little is known about the non-market strategies adopted by firms in emerging economies, such as China, in response to economic policy uncertainty. This study proposes that firms in China respond to high levels of economic policy uncertainty by increasing philanthropic donations and bribery. In addition, this study argues that private firms and state-owned firms implement different strategies to cope with economic policy uncertainty. Specifically, the study suggests that state-owned enterprises (SOEs) are more likely, than non-SOEs, to respond to economic policy uncertainty by increasing corporate philanthropy, and less likely to respond by increasing expenditure on bribes. This study obtained empirical evidence to support these views, based on an analysis of a dataset of 2,904 listed Chinese firms from 2008 to 2019. [ABSTRACT FROM AUTHOR]

Pattern-illuminated Fourier ptychography (piFP) is an elegant combination of structured illumination imaging and a Fourier ptychographic algorithm with the ability to image beyond the diffraction limit of the employed optics. Artifact-free piFP super-resolution reconstruction requires a high level of stability in the illumination pattern. However, unpredictable pattern variation occurs in the presence of environment perturbation, intensity fluctuation, and pointing instability at the source, leading to declines in image reconstruction quality. To address this issue, we present an efficient and robust piFP algorithm based on low-rank approximation (LRA-piFP), which relaxes the requirement for the stability of illumination patterns. This LRA-piFP method can model frame-wise pattern variation during a full scan, thus improve the reconstruction quality significantly. We take numerical simulations and proof-of-principle experiments with both long-range imaging and microscopy for demonstrations. Results show that the LRA-piFP method can handle different kinds of pattern variation and outperforms other state-of-the-art techniques in terms of reconstruction quality and resolution improvement. Our method provides effective experimental robustness to piFP with a natural algorithmic extension, paving the way for its application in both macroscopic and microscopic imaging. [ABSTRACT FROM AUTHOR]

This study concerns the problem of integrated optimization of structure and control based on a fast steering mirror, aiming to achieve simultaneous optimization of the mechanical structure and control system. The traditional research and development path of the fast steering mirror involves a lengthy process from the initial design to the final physical manufacture. In the prior process, it was necessary to produce physical prototypes for repeated debugging and iterative optimization to achieve design requirements, but this approach consumes a significant amount of time and cost. To expedite this process and reduce unnecessary experimental costs, this study proposes an integrated optimization of structure and control (IOSC) method. With the use of IOSC, it is possible to achieve simultaneous optimization of structure and control. Specifically, the use of non-dominated sorting genetic algorithm II (NSGA-II) obtains globally optimal controller parameters and mechanical structure parameters under certain performance indices. This achieves an effective balance between the resonance frequency generated by the system and the working bandwidth, providing a high-precision reference for the research and development of fast steering mirrors. [ABSTRACT FROM AUTHOR]

Whether and when differentiation strategies affect firms' environmental, social and governance (ESG) involvement remains unclear. Based on resource‐based view and behavioral theory of the firm, we propose that as the degree of differentiation strategies increases, firms' motivation to engage in ESG increases. Additionally, we propose that performance shortfalls moderate the relationship between differentiation strategies and a firm's ESG involvement. Specifically, we argue that historical performance shortfalls enhance this relationship, whereas social performance shortfalls weaken it. Using a large longitudinal dataset constructed from empirical data on Chinese listed companies from 2011 to 2020, we find strong support for these theoretical arguments. This study extends the differentiation strategies, and ESG literature by providing the first large sample of evidence that differentiation strategy is a key factor in facilitating firms' ESG involvement. The findings of this study also help firms to enhance their ESG practices by revisiting their existing strategies and relative performance. [ABSTRACT FROM AUTHOR]

Simple Summary: Dynamic chest radiographs offer a distinct advantage over traditional chest radiographs by integrating motion and functional data, elevating their significance in clinical diagnostics. This study introduces a pioneering technique employing deep neural networks to simulate respiratory lung motion and extract local functional details from single-phase chest X-rays, thereby enhancing lung cancer clinical diagnostic capabilities. Our research establishes the viability of generating patient-specific respiratory motion profiles from single-phase chest radiographs. The evaluation of results from the network developed here underscores its substantial accuracy and fidelity, affirming its robustness in providing valuable supplementary insights into pulmonary function. In this study, we present an innovative approach that harnesses deep neural networks to simulate respiratory lung motion and extract local functional information from single-phase chest X-rays, thus providing valuable auxiliary data for early diagnosis of lung cancer. A novel radiograph motion simulation (RMS) network was developed by combining a U-Net and a long short-term memory (LSTM) network for image generation and sequential prediction. By utilizing a spatial transformer network to deform input images, our proposed network ensures accurate image generation. We conducted both qualitative and quantitative assessments to evaluate the effectiveness and accuracy of our proposed network. The simulated respiratory motion closely aligns with pulmonary biomechanics and reveals enhanced details of pulmonary diseases. The proposed network demonstrates precise prediction of respiratory motion in the test cases, achieving remarkable average Dice scores exceeding 0.96 across all phases. The maximum variation in lung length prediction was observed during the end-exhale phase, with average deviation of 4.76 mm (±6.64) for the left lung and 4.77 mm (±7.00) for the right lung. This research validates the feasibility of generating patient-specific respiratory motion profiles from single-phase chest radiographs. [ABSTRACT FROM AUTHOR]

Based on the special background of transition economies, in which governments play a particularly important role in firms' survival and development, we discuss the impact of performance shortfall on firms' tax avoidance, which is a behavior that is considered unethical and irresponsible by the public. Drawing upon performance feedback theory and institutional theory, we propose that performance shortfall will drive firms to reduce tax avoidance to enhance their political legitimacy, thereby gaining more government support to solve current performance problems. We also argue that the relationship between performance shortfall and firms' tax avoidance is likely nuanced and may vary by institutional logics (e.g., state-owned enterprises (SOEs)), and regional marketization degree). Specifically, we argue that SOEs will strengthen the above-mentioned relationship, and the regional marketization degree will weaken the above-mentioned relationship. After testing listed companies in China as the research object, we find that most of our theoretical views are supported by empirical evidence. [ABSTRACT FROM AUTHOR]

Purpose: Many studies have examined the antecedents of firms' strategic change on a micro and meso level, but few studies have explored it from the macrolevel (e.g. economic policy uncertainty) perspective. This research draws attention to the impact of economic policy uncertainty on firms' strategic change. Design/methodology/approach: This research empirically tests hypotheses based on a sample of listed firms in China during the period between 2010 and 2017. Findings: Based on real options theory, the authors theorize and find that economic policy uncertainty will negatively affect firms' strategic change through the mediating effect of CEO turnover. Moreover, organizational inertia will strengthen the negative impact of economic policy uncertainty on CEO turnover and will weaken the positive impact of CEO turnover on firms' strategic change. Originality/value: First, this research contributes to the strategic change literature by demonstrating the important impact of economic policy uncertainty on firms' strategic change. Second, this research expands the literature on the economic consequences of economic policy uncertainty. Third, this research clarifies the path and boundary conditions of economic policy uncertainty affecting strategic change by introducing the mediating effects of CEO turnover and the moderating effects of organizational inertia. [ABSTRACT FROM AUTHOR]

Accurate and robust prostate segmentation in transrectal ultrasound (TRUS) images is of great interest for ultrasound-guided brachytherapy for prostate cancer. However, the current practice of manual segmentation is difficult, time-consuming, and prone to errors. To overcome these challenges, we developed an accurate prostate segmentation framework (A-ProSeg) for TRUS images. The proposed segmentation method includes three innovation steps: (1) acquiring the sequence of vertices by using an improved polygonal segment-based method with a small number of radiologist-defined seed points as prior points; (2) establishing an optimal machine learning-based method by using the improved evolutionary neural network; and (3) obtaining smooth contours of the prostate region of interest using the optimized machine learning-based method. The proposed method was evaluated on 266 patients who underwent prostate cancer brachytherapy. The proposed method achieved a high performance against the ground truth with a Dice similarity coefficient of 96.2% ± 2.4%, a Jaccard similarity coefficient of 94.4% ± 3.3%, and an accuracy of 95.7% ± 2.7%; these values are all higher than those obtained using state-of-the-art methods. A sensitivity evaluation on different noise levels demonstrated that our method achieved high robustness against changes in image quality. Meanwhile, an ablation study was performed, and the significance of all the key components of the proposed method was demonstrated. [ABSTRACT FROM AUTHOR]

Purpose: This study aims to re-examine the impact of economic policy uncertainty (EPU) on firm innovation. Studies on how EPU affects firm innovation have been inconclusive. The authors clarified the curvilinear relationship between EPU and firm innovation and examined the moderating effects of managerial pay gaps, specifically vertical pay disparity and horizontal pay dispersion. Design/methodology/approach: This study's analyses used data collected from Chinese listed companies from 2007 to 2019. Findings: The authors found an inverted U-shaped relationship between EPU and firm innovation. Furthermore, vertical pay disparity strengthens the curvilinear relationship, while horizontal pay dispersion weakens it. Practical implications: First, politicians should avoid adjusting economic policies too frequently because the high EPU levels created by frequent adjustments can inhibit business innovation. Second, firms should be aware that EPU creates opportunities for leapfrogging. In particular, firms can incentivize executives to take advantage of the valuable growth opportunities presented by EPU by widening vertical pay disparities and avoiding excessive horizontal pay dispersion. Originality/value: First, the authors analyze not only the positive effects of lower EPU on firm innovation but also the negative impacts of higher EPU to examine EPU's "double-edged sword" effect on firm innovation. Second, the investigation of vertical pay disparity and horizontal pay dispersion as moderating variables sheds new light on the equivocal research findings regarding the EPU–firm innovation relationship and clarifies the boundary conditions of the double-edged sword effect of EPU on firm innovation. [ABSTRACT FROM AUTHOR]

Integrating the behavioral theory of the firm and agency theory, this study is the first to examine the antecedents of firms' choice to disclose low‐quality accounting information from the perspective of performance persistence below aspirations. Based on empirical data of 31,326 firm‐annual observations involving 3584 listed companies for the 2007–2021 period, we find that firms actively reduce accounting information reliability and comparability in the presence of performance persistence below aspirations. Furthermore, we find that CEO‐CFO surname ties enhance the negative effect of performance persistence below aspirations on accounting information comparability. Finally, we find that agency costs play a mediating role in the relationship that performance persistence below aspirations has with accounting information reliability and comparability. This study is the first to examine performance persistence below aspirations and accounting information reliability and comparability. Meanwhile, this study provides important insights for policymakers to improve the quality of capital market information and for shareholders to improve the quality of corporate governance. [ABSTRACT FROM AUTHOR]

Green innovation is an important way for manufacturing enterprises to achieve green and high-quality development. The existing literature has ignored the heterogeneous motivations for enterprise green innovation. The strategic green innovation behavior (SGIB) aiming at seeking strategic differences and building core competitiveness is the necessary measure for enterprises to realize green transformation. Furthermore, the existing research studies the influencing factors of green innovation from a single perspective, ignoring the interaction of institutional and resource factors. Based on this, this study uses QCA to identify the driving mechanism of enterprise SGIB. The research collected questionnaire data from 199 manufacturing enterprises in China. The main results show that a single factor will not constitute a necessary condition for positive SGIB, but the not-high green dynamic capability is a necessary condition for negative SGIB. Positive SGIB includes four configuration paths: institution-ethics synergy, normative pressure oriented, environmental ethics oriented, and institutional incentive oriented. Lack of institutional pressure is the only configuration path that leads to negative SGIB. Further analysis found that environmental ethics and institutional pressure are the main forces to promote SGIB. After a series of robustness tests, the above basic conclusions did not change significantly. Based on the above conclusions, we believe that government departments, industry associations, and enterprises should form a joint force to enhance the level of institutional pressure and enterprise environmental ethics, promoting the implementation of strategic green innovation. [ABSTRACT FROM AUTHOR]

This study examines the impact of returnee executives on top management teams' (TMTs') unethical management behavior (e.g., excess perquisite consumption). Synthesizing insights from upper echelons theory and the psychological entitlement literature, this study proposes that returnee executives cause TMTs to generate a high degree of psychological entitlement, which subsequently leads to a high degree of excess perquisite consumption in their firms. In addition, this study proposes that returnee chief executive officers, product diversification, and regional institutional development moderate the aforementioned relationships by influencing managerial discretion. This study provides empirical evidence for the above view using a dataset that was constructed based on 1960 listed Chinese manufacturing companies from 2010 to 2019. From a psychological entitlement perspective, this study confirms, for the first time, that the introduction of returnee executives may have unintended negative consequences, for example, in promoting the excess perquisite consumption activities of TMTs. [ABSTRACT FROM AUTHOR]

Purpose: The phenomenon of defamilization of family firms is gradually increasing for the growth of family firms, that is, nonfamily executives are increasingly present in the executive teams of family firms. Although previous scholars have identified various determinants of family firms' defamilization, whether and when innovation underperformance affects the decision to defamilize family firms has not been explore. This study aims to fill the aforementioned research gaps. Design/methodology/approach: This study empirically tests the theoretical view based on the data of Chinese A-share family listed companies from 2009 to 2017. Findings: The authors found that innovation underperformance drives family companies to increase the percentage of nonfamily executives in their executive teams. Further, the authors found that family firms are less willing to hire nonfamily executives with an increase in socioemotional wealth, particularly when founders of such businesses serve as directors or are major shareholders, even when they are not directors. Originality/value: This study shows that innovation underperformance and socioemotional wealth are important predictors of family firms' defamilization decisions. [ABSTRACT FROM AUTHOR]

The constant increase in temperatures under global warming has led to a prolonged aestivation period for Apostichopus japonicus, resulting in considerable losses in production and economic benefits. However, the specific mechanism of aestivation has not been fully elucidated. In this study, we first tried to illustrate the biological mechanisms of aestivation from the perspective of the gut microbiota and metabolites. Significant differences were found in the gut microbiota of aestivating adult A. japonicus (AAJSD group) compared with nonaestivating adult A. japonicus (AAJRT group) and young A. japonicus (YAJRT and YAJSD groups) based on 16S rRNA gene high-throughput sequencing analysis. The abundances of Desulfobacterota, Myxococcota, Bdellovibrionota, and Firmicutes (4 phyla) in the AAJSD group significantly increased. Moreover, the levels of Pseudoalteromonas, Fusibacter, Labilibacter, Litorilituus, Flammeovirga, Polaribacter, Ferrimonas, PB19, and Blfdi19 genera were significantly higher in the AAJSD group than in the other three groups. Further analysis of the LDA effect size showed that species with significant variation in abundance in the AAJSD group, including the phylum Firmicutes and the genera Litorilituus, Fusibacter, and Abilibacter, might be important biomarkers for aestivating adult A. japonicus. In addition, the results of metabolomics analysis showed that there were three distinct metabolic pathways, namely biosynthesis of secondary metabolites, tryptophan metabolism, and sesquiterpenoid and triterpenoid biosynthesis in the AAJSD group compared with the other three groups. Notably, 5-hydroxytryptophan was significantly upregulated in the AAJSD group in the tryptophan metabolism pathway. Moreover, the genera Labilibacter, Litorilituus, Ferrimonas, Flammeovirga, Blfdi19, Fusibacter, Pseudoalteromonas, and PB19 with high abundance in the gut of aestivating adult A. japonicus were positively correlated with the metabolite 5-HTP. These findings suggest that there may be potential biological associations among the gut microbiota, metabolites, and aestivation in A. japonicus. This work may provide a new perspective for further understanding the aestivation mechanism of A. japonicus. [ABSTRACT FROM AUTHOR]

The hemodynamic characteristics of venous reflux are associated with infertility in patients with varicocele; however, an effective method for quantifying the structural distribution of the reflux is lacking. This study aimed to predict surgical outcomes using a new software for venous reflux quantification. This was a retrospective cohort study of a consecutive series of 105 patients (age range: 22–44 years) between July 2017 and September 2019. Venous reflux of the varicocele was obtained using the Valsalva maneuver during scrotal Doppler ultrasonography before microsurgical varicocelectomy. Using this software, the colored reflux signals were segmented, and the gray scale of the color pixels representing the reflux velocity was comprehensively quantified into the mean reflux velocity of the green layer (MRVG) and the reflux velocity standard deviation of the green layer (RVSDG). Spontaneous pregnancy and changes from baseline in the semen parameters were assessed during a 12-month follow-up period. Data were analyzed using logistic regression analysis. An association of the high MRVG group with impaired progressive motility (odds ratio [OR] = 2.868, 95% confidence interval [CI]: 1.133–7.265) and impaired sperm concentration (OR = 2.943, 95% CI: 1.196–7.239) was found during multivariate analysis. High MRVG (OR = 2.680, 95% CI: 1.086–6.614) and high RVSDG (OR = 2.508, 95% CI: 1.030–6.111) were found to be independent predictors of failure to achieve pregnancy following microsurgical repair. In summary, intense venous reflux is an independent predictor of impaired progressive motility, sperm concentration, and pregnancy outcomes after microsurgical varicocelectomy. [ABSTRACT FROM AUTHOR]

In this paper we consider a breathing circle billiard which is described as a particle that travels inside a time-dependent circular domain and elastically reflecting from the boundary. Between collisions the particle moves with a constant speed along straight lines connecting the collision points. We show that in high energy situation, the dynamics of the system can be studied by constructing an area-preserving monotone twist map. Under appropriate assumptions, it is proved that there exist infinitely many bounded complete orbits, and a large class of periodic and quasi-periodic orbits for the system. This gives a description of the global dynamical behavior of the system. [ABSTRACT FROM AUTHOR]

This study explores the role of executive vertical pay disparity in explaining firms' choice of CSR activities (internal vs. external CSR). Based on tournament theory and the attention-based view, we first propose that vertical pay disparity leads executives to increase CSR activities, but in this process, compared to external CSR activities, executives are more likely to increase internal CSR activities. We then propose that the effect of executive vertical pay disparity on the choice of CSR activities will be moderated by three situational cues: state-owned enterprises (SOEs), litigation risk, and slack resources. Empirical analyses based on unbalanced panel data of China's listed manufacturing firms from 2010 to 2018 show that our hypotheses are largely supported. Our results show that vertical pay disparity drives executives to increase CSR activities that contribute to the long-term interests of shareholders; however, in the process, executives focus on certain stakeholders over others. [ABSTRACT FROM AUTHOR]

Purpose: Current computed tomography (CT)‐based lung ventilation imaging (CTVI) techniques derive a static ventilation image without temporal information. This research aims to develop a four‐dimensional CT (4DCT)‐based multiphase dynamic ventilation imaging framework capable of recovering the entire ventilation process throughout the breathing cycle for functional lung avoidance radiotherapy (FLART). Methods: A total of 15 free‐breathing thoracic 4DCT scans of lung or esophageal cancer patients were collected from the public datasets. The lung region of each phase image was first delineated, and then the mask‐free isotropic total variation image registration algorithm was used to derive the deformation vector fields between the end‐expiration (EE) phase and other phases. As a surrogate of ventilation, the voxel‐wise local expansion ratio of each phase relative to the EE phase was estimated using the parameterized Integrated Jacobian Formulation method in the EE phase coordinate. Lastly, the dynamic ventilation images were generated by warping these phase‐specific local expansion distributions with a same geometry into their respective breathing phases. Quantitative analysis, including interphase Spearman correlation coefficients, voxel‐wise, and regional‐wise expansion/contraction tracking, were performed to indirectly validate the proposed method. Results: The proposed method maintains the physiological meaning of ventilation on each phase and enables to recover the dynamic lung ventilation process. The mean interphase Spearman correlations ranged between 0.23 ± 0.20 and 0.93 ± 0.04 and decreased near the EE phase. Only 26.2% (2.59E + 6 out of 9.89E + 6) of lung voxels exhibited the same expansion/contraction pattern as the global lung. Qualitative and quantitative evaluations of the interphase ventilation distribution difference show that ventilation spatiotemporal heterogeneities generally exist during respiration. Conclusions: In contrast to conventional CTVI metrics, our method enables to extract additional phase‐resolved respiration‐correlated information and reflects the generally existed ventilation spatiotemporal heterogeneities. Subsequent studies with quantitative phase‐by‐phase cross‐modality evaluations will further explore its potential to deepen our understanding of lung function and respiration mechanics and also to facilitate more accurate implementation of FLART. [ABSTRACT FROM AUTHOR]

Purpose: Whether and when the innovation aspiration shortfall (e.g. innovation performance lower than aspirations) will affect emerging economy firms (EEFs)' international expansion remains an important unanswered theoretical and practical question. Design/methodology/approach: Based on performance feedback theory, this study explores the impact of innovation aspiration shortfall on EEFs' international expansion and the moderating role of CEO origin. Findings: This study finds that innovation aspiration shortfall has a positive impact on EEFs' international expansion. This study also uncovers that EEFs are less likely to implement international expansion in response to innovation aspiration shortfall when the CEO is a founder than when the CEO is a non-founder, and EEFs are more likely to implement international expansion in response to innovation aspiration shortfall when the CEO is an outsider-CEO than when the CEO is an insider-CEO. Originality/value: This study proposes that the interaction between innovation aspiration shortfall and CEO origin can be a useful predictor of EEFs' international expansion. [ABSTRACT FROM AUTHOR]

A noised phase-unwrapping method is presented by using the Wigner distribution function to filter the phase noise and restore the gradient of the phase map. By using Poisson's equation, the unwrapped phase map was obtained. Compared with the existing methods, the proposed method is theoretically simple, provides a more accurate representation, and can be implemented in light-field hardware devices, such as Shack-Hartmann sensors. [ABSTRACT FROM AUTHOR]

Moving contact components are common in mechanical systems, and they exhibit a large rigid motion with linear‐elastic deflection under contact boundary conditions. The finite element method can capture local deformation and high gradient stresses, but finely meshed contact interfaces lead to numerous degrees of freedom. Model order reduction techniques for multibodies are effective, but moving contact interfaces also introduce multiple interface degrees of freedom. In the present method, the interface degrees of freedom are retained to ensure the accuracy of the local response induced by contacts, but the computational scale is not further enlarged. The motion of moving contact components is described by the floating frame of reference formulation. A free‐interface component mode synthesis method is proposed for model order reduction. Kept free‐interface normal modes represent global flexibility and residual modes accurately compensate for the local quasi‐static responses of omitted modes induced by contacts. The contribution of residual modes is represented by interface load coordinates, which can be directly evaluated by contact forces. The contacts are calculated with the present contact algorithm. The accuracy and efficiency of the proposed method are fully demonstrated through correlation with the finite element method in gear meshing simulations. [ABSTRACT FROM AUTHOR]

Based on signaling theory, we explore the impact of corporate fraud on firms' innovation performance. First, we propose that corporate fraud harms firms' innovation performance. This is because, as a negative signal, fraud makes it difficult for firms to obtain the policy, funding, and human resources needed for outstanding innovation performance. We further argue that the institutional aspects of the signaling environment (e.g., industrial competition, regional institutional development, and social trust) will influence core stakeholders' reception and interpretation of fraud signals. These factors, in turn, moderate the signaling effect of corporate fraud on firms' innovation performance. Our views are supported by empirical and robustness tests using Chinese A‐share listed firms from 2010 to 2019. [ABSTRACT FROM AUTHOR]

Purpose: Based on the tournament theory and the principal agent theory, this study aims to empirically investigate how top management team (TMT) vertical pay disparity (the pay disparity between the CEO and non-CEO executives) influences firm innovation performance. Design/methodology/approach: This study empirically tested the hypotheses based on a sample of listed high-tech companies in China during the period between 2007 and 2018. Findings: TMT vertical pay disparity promotes innovation performance; CEO power undermines the positive effect of TMT vertical pay disparity on innovation performance; the negative moderating effect of CEO power is mitigated by board age and gender and educational levels, whereas the proportion of female directors has no such effect at any significant level. Originality/value: This study uniquely contributes to the theoretical and empirical development of tournament theory and the principal agent theory. [ABSTRACT FROM AUTHOR]

Failure is an unavoidable part of the innovation process. Previous studies have explored the impact of innovation failures on a variety of strategic actions. However, to date, whether and when firms – especially those in emerging economies – adopt overseas research and development (R&D) strategies in response to innovation failures remains unexplored. By integrating insights from the behavioural theory of the firm (BTOF) and springboard theory, our study theoretically analyzes and empirically examines the impact of continuous innovation failure on the overseas R&D activities of companies in emerging economies. Using a dataset comprised of Chinese listed manufacturing firms, we find that continuous innovation failure is positively related to the overseas R&D activities of companies in emerging economies. After considering the moderating effect of top management team (TMT) relational capital, we also find that TMT financial relational capital weakens the above relationship, while TMT government relational capital strengthens it. [ABSTRACT FROM AUTHOR]

Background: Most available four‐dimensional (4D)‐magnetic resonance imaging (MRI) techniques are limited by insufficient image quality and long acquisition times or require specially designed sequences or hardware that are not available in the clinic. These limitations have greatly hindered the clinical implementation of 4D‐MRI. Purpose: This study aims to develop a fast ultra‐quality (UQ) 4D‐MRI reconstruction method using a commercially available 4D‐MRI sequence and dual‐supervised deformation estimation model (DDEM). Methods: Thirty‐nine patients receiving radiotherapy for liver tumors were included. Each patient was scanned using a time‐resolved imaging with interleaved stochastic trajectories (TWIST)–lumetric interpolated breath‐hold examination (VIBE) MRI sequence to acquire 4D‐magnetic resonance (MR) images. They also received 3D T1‐/T2‐weighted MRI scans as prior images, and UQ 4D‐MRI at any instant was considered a deformation of them. A DDEM was developed to obtain a 4D deformable vector field (DVF) from 4D‐MRI data, and the prior images were deformed using this 4D‐DVF to generate UQ 4D‐MR images. The registration accuracies of the DDEM, VoxelMorph (normalized cross‐correlation [NCC] supervised), VoxelMorph (end‐to‐end point error [EPE] supervised), and the parametric total variation (pTV) algorithm were compared. Tumor motion on UQ 4D‐MRI was evaluated quantitatively using region of interest (ROI) tracking errors, while image quality was evaluated using the contrast‐to‐noise ratio (CNR), lung–liver edge sharpness, and perceptual blur metric (PBM). Results: The registration accuracy of the DDEM was significantly better than those of VoxelMorph (NCC supervised), VoxelMorph (EPE supervised), and the pTV algorithm (all, p < 0.001), with an inference time of 69.3 ± 5.9 ms. UQ 4D‐MRI yielded ROI tracking errors of 0.79 ± 0.65, 0.50 ± 0.55, and 0.51 ± 0.58 mm in the superior–inferior, anterior–posterior, and mid–lateral directions, respectively. From the original 4D‐MRI to UQ 4D‐MRI, the CNR increased from 7.25 ± 4.89 to 18.86 ± 15.81; the lung–liver edge full‐width‐at‐half‐maximum decreased from 8.22 ± 3.17 to 3.65 ± 1.66 mm in the in‐plane direction and from 8.79 ± 2.78 to 5.04 ± 1.67 mm in the cross‐plane direction, and the PBM decreased from 0.68 ± 0.07 to 0.38 ± 0.01. Conclusion: This novel DDEM method successfully generated UQ 4D‐MR images based on a commercial 4D‐MRI sequence. It shows great promise for improving liver tumor motion management during radiation therapy. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the role of different multi-organ omics-based prediction models for pre-treatment prediction of Adaptive Radiotherapy (ART) eligibility in patients with nasopharyngeal carcinoma (NPC). Methods and Materials: Pre-treatment contrast-enhanced computed tomographic and magnetic resonance images, radiotherapy dose and contour data of 135 NPC patients treated at Hong Kong Queen Elizabeth Hospital were retrospectively analyzed for extraction of multi-omics features, namely Radiomics (R), Morphology (M), Dosiomics (D), and Contouromics (C), from a total of eight organ structures. During model development, patient cohort was divided into a training set and a hold-out test set in a ratio of 7 to 3 via 20 iterations. Four single-omics models (R, M, D, C) and four multi-omics models (RD, RC, RM, RMDC) were developed on the training data using Ridge and Multi-Kernel Learning (MKL) algorithm, respectively, under 10-fold cross validation, and evaluated on hold-out test data using average area under the receiver-operator-characteristics curve (AUC). The best-performing single-omics model was first determined by comparing the AUC distribution across the 20 iterations among the four single-omics models using two-sided student t -test, which was then retrained using MKL algorithm for a fair comparison with the four multi-omics models. Results: The R model significantly outperformed all other three single-omics models (all p-value<0.0001), achieving an average AUC of 0.942 (95%CI: 0.938-0.946) and 0.918 (95%CI: 0.903-0.933) in training and hold-out test set, respectively. When trained with MKL, the R model (R_MKL) yielded an increased AUC of 0.984 (95%CI: 0.981-0.988) and 0.927 (95%CI: 0.905-0.948) in training and hold-out test set respectively, while demonstrating no significant difference as compared to all studied multi-omics models in the hold-out test sets. Intriguingly, Radiomic features accounted for the majority of the final selected features, ranging from 64% to 94%, in all the studied multi-omics models. Conclusions: Among all the studied models, the Radiomic model was found to play a dominant role for ART eligibility in NPC patients, and Radiomic features accounted for the largest proportion of features in all the multi-omics models. [ABSTRACT FROM AUTHOR]

This study integrates organizational identity (OI) theory and upper echelons theory to explore the impact of CEOs' founder status on corporate social irresponsibility (CSI). We theorize that compared with other CEOs, a founder CEO is more likely to generate a high degree of OI with the firm, which will drive the founder CEO to actively avoid CSI that may damage the positive image and long‐term development of the firm. Furthermore, we argue that CEO duality and CEO ownership will strengthen the aforementioned relationship by increasing the possibility of founder CEOs generating a high degree of OI. Conversely, CEO underpayment will weaken the relationship between founder status and CSI by decreasing the possibility of founder CEOs generating a high degree of OI. We obtained empirical evidence in support of our arguments from a large Chinese private listed company dataset. Overall, this study's theory and evidence clearly show that founder status and personal incentives can jointly shape CEOs' CSI decisions, thereby providing useful insights for corporate shareholders and government agencies to better prevent and govern firms' CSI. [ABSTRACT FROM AUTHOR]

Purpose: Drawing on the gender self-schema theory, upper echelons theory and the literature on international business, this study aims to examine the impact of board gender diversity on firms' internationalization speed. Design/methodology/approach: In this study, secondary data of 886 listed Chinese manufacturing firms from 2009 to 2018 are studied using the ordinary least squares regression model as the baseline method, an instrumental variable method is adopted for endogeneity control and both fixed and random effect models are adopted for the robustness test. Findings: Board gender diversity reduces firms' internationalization speed, and the negative effect between board gender diversity and internationalization speed is stronger when the average age of female directors is older and weaker when female directors have international experience or financial background. Practical implications: First, Chinese firms need to increase or decrease board gender diversity to match the board to firms' internationalization strategy. Increasing board gender diversity may be a more appropriate choice for firms that are expanding rapidly internationally, and vice versa. Second, when introducing female directors to international firms, it is essential to address other characteristics of these directors beyond their gender. Originality/value: First, the authors contribute to the literature on board gender diversity using Chinese manufacturing firms as our research sample, which provides new insights into the economic consequences of increasing the number of female directors. Second, this research contributes to the literature on firms' internationalization speed. Third, the authors capture in more detail the economic consequences of increasing board gender diversity in the context of China. [ABSTRACT FROM AUTHOR]

Mechanically robust optical homogeneous polyimide (PI) films with desirable atomic oxygen (AO) erosion duration were fabricated by initially synthesizing amine-functionalized hyperbranched polysiloxane (NH2-HBPSi), then reinforcing the pristine polyimide skeleton with it via copolycondensation reactions. NH2-HBPSi macromolecule imparts desirable AO survivability to the resulting hybrids. The mass loss per unit area of hybrid films had a downward trend with rising NH2-HBPSi content and AO dose before the complete silica protective layer was formed. It has been proven by the experiments in an underground simulated AO environment. It decreased to 1% of that of pristine polyimide when NH2-HBPSi accounted for 30% of the solid content after 24 h AO attack. The stable thickness uniformity that can meet the Rayleigh criterion was achieved in a 30 wt% HBPSi PI film, mainly due to the selection of the best process parameters. Meanwhile, 30 wt% HBPSi PI demonstrates satisfactory mechanical properties, with a tensile strength of 228.9 MPa and elongation at break of 7.3%. The characterization of scanning electron microscopy confirmed that pristine polyimide was substantially eroded after AO exposure while the surface morphology of 30 wt% HBPSi polyimide showed no evident change. The low AO erosion yield and prominent film thickness uniformity may find extensive usage in ultra-lightweight space diffractive optical elements (DOE) working in low earth orbit (LEO). [ABSTRACT FROM AUTHOR]

Purpose. This study aims to investigate the feasibility of different acquisition methods for time-resolved magnetic resonance fingerprinting (TR-MRF) in computer simulation. Methods. An extended cardiac-torso (XCAT) phantom is used to generate abdominal T1, T2, and proton density maps for MRF simulation. The simulated MRF technique consists of an IR-FISP MRF sequence with spiral trajectory acquisition. MRF maps were simulated with different numbers of repetitions from 1 to 15. Three different methods were used to generate TR-MRF maps: (1) continuous acquisition without delay between MRF repetitions; (2) continuous acquisition with 5 s delay between MRF repetitions; (3) triggered acquisition with variable delay between MRF repetitions to allow the next acquisition to start at different respiration phase. After the generation of TR-MRF maps, the image quality indexes including the absolute T1 and T2 values, signal-to-noise-ratio (SNR), tumor-to-liver contrast-to-noise ratio, error in the amplitude of diaphragm motion and tumor volume error were used to evaluate the reconstructed parameter maps. Three volunteers were recruited to test the feasibility of the selected acquisition method. Results. Dynamic MR parametric maps using three different acquisition methods were estimated. The overall and liver T1 value error, liver SNR in T1 and T2 maps, and tumor SNR from T1 maps from triggered method is statistically significantly better than the other two methods (p-value < 0.05). The other image quality indexes have no significant difference between the triggered method and the other two continuous acquisition methods. All image quality indexes exhibit no significant difference between the acquisition methods with 0 s and 5 s delay. The triggered method was successfully performed in three healthy volunteers. Conclusion. TR-MRF technique was investigated using three different acquisition methods in computer simulation where the triggered method showed better performance than the other two methods. The triggered method has been tested successfully in healthy volunteers. [ABSTRACT FROM AUTHOR]

Functional lung avoidance radiation therapy aims to minimize dose delivery to the normal lung tissue while favoring dose deposition in the defective lung tissue based on the regional function information. However, the clinical acquisition of pulmonary functional images is resource-demanding, inconvenient, and technically challenging. This study aims to investigate the deep learning-based lung functional image synthesis from the CT domain. Forty-two pulmonary macro-aggregated albumin SPECT/CT perfusion scans were retrospectively collected from the hospital. A deep learning-based framework (including image preparation, image processing, and proposed convolutional neural network) was adopted to extract features from 3D CT images and synthesize perfusion as estimations of regional lung function. Ablation experiments were performed to assess the effects of each framework component by removing each element of the framework and analyzing the testing performances. Major results showed that the removal of the CT contrast enhancement component in the image processing resulted in the largest drop in framework performance, compared to the optimal performance (~12%). In the CNN part, all the three components (residual module, ROI attention, and skip attention) were approximately equally important to the framework performance; removing one of them resulted in a 3–5% decline in performance. The proposed CNN improved ~4% overall performance and ~350% computational efficiency, compared to the U-Net model. The deep convolutional neural network, in conjunction with image processing for feature enhancement, is capable of feature extraction from CT images for pulmonary perfusion synthesis. In the proposed framework, image processing, especially CT contrast enhancement, plays a crucial role in the perfusion synthesis. This CTPM framework provides insights for relevant research studies in the future and enables other researchers to leverage for the development of optimized CNN models for functional lung avoidance radiation therapy. [ABSTRACT FROM AUTHOR]

Featured Application: This method is mainly applied to gradient index media with a sudden change in refractive index or a large range of refractive index gradient changes, such as around the shock layer of an aircraft. For gradient refractive index media with large refractive index gradients, traditional ray tracing methods based on refined elements or spatial geometric steps have problems such as low tracing accuracy and efficiency. The ray tracing method based on refractive index steps proposed in this paper can effectively solve this problem. This method uses the refractive index step to replace the spatial geometric step. The starting point and the end point of each ray tracing step are on the constant refractive-index surfaces. It avoids the problem that the traditional tracing method cannot adapt to the area of sudden change in the refractive index and the area where the refractive index changes sharply. Therefore, a suitable distance can be performed in the iterative process. It can achieve high-efficiency and precise ray tracing in areas whether the refractive index changes slowly or sharply. According to the comparison of calculation examples, this method can achieve a tracing accuracy of 10 − 5 mm. The speed and precision of ray tracing are better than traditional methods. [ABSTRACT FROM AUTHOR]

On the process of alignment for pupil off-axis telescope system, the determination of decentering and tilt misalignments is a key step. In this paper, we proposed a new method which adopts the fully connected neural network (FCNN) as a fitting tool to establish the nonlinear mapping relation between misalignments of different fields of view (FOVs) and Zernike coefficients. Firstly, we establish a pupil off-axis reflection telescope model, then decentering and tilt misalignments are introduced to acquire corresponding aberrations that represented by Zernike coefficients. We use aberrations as the inputs of FCNN; misalignments and FOV as outputs. FCNN is trained by the combination of inputs and outputs as a dataset, and we use a new dataset to test the accuracy and effectiveness of the trained FCNN. The results show that the mean absolute error (MAE) of the X-axis decentering error, V-axis tilt error and angle of view are 0.0506 mm, 0.0204° and 0.0124°, respectively. These results demonstrate that the proposed method is effective and feasible to calculate the misalignments. [ABSTRACT FROM AUTHOR]

The main disadvantage of windowless beam expansion systems is that they cannot achieve a good sealing effect. Turbulence and impurities in the environment can easily affect the imaging and primary mirror. Thus, in this study, a matrix of small holes was introduced for inflation to form a stable and smooth flow inside the system to avoid these disadvantages. In order to study the layout of the matrix, the flow state of the model was analysed, and the Lorentz–Lorenz formula and Barron gradient operator were used for ray tracing. Simulation results show that when the matrix of small holes is arranged in 16 rows with 360 holes in each row, inflation has a lesser effect on the wavefront aberration of the system. Moreover, the root mean square (RMS) of wavefront aberration was only 0.077 μm, which was superior to the other layouts considered. Experimental results show that the RMS was 0.08 μm in this state, which is consistent with the analysis. This indicates that this analysis method can meet actual work needs. The calculation methods and calculation results have high reliability and, thus, can be also used in similar situations. [ABSTRACT FROM AUTHOR]

Incoherent Fourier Ptychography (IFP) is a super-resolution imaging method, which requires lots of iteration time to recover the high-resolution object image from raw images. To improve the convergence rate of the IFP, we propose an improved algorithm, termed momentum-accelerated Incoherent Fourier Ptychography (mIFP). Based on the IFP algorithm, the mIFP adds momentum that is commonly used to accelerate the training of weights in a neural network. During the update process, the current vector is updated based on the downward trend of the objective function during several updates and the previous vector. The updated vector is then added to the objective function. We demonstrate the proposed approach by both simulations and experiments. By reducing the recovery time, mIFP may accelerate the applications of IFP. [ABSTRACT FROM AUTHOR]

Synthetic aperture imaging systems can be applied to equivalently get high-resolution images of traditional monolithic primary mirror systems with less weight and costs. Spatial modulation diversity (SMD), a newly developed post-processing technology applicable for such synthetic aperture systems, is very sensitive to Gaussian noise, which greatly limits its further application. In this paper, we propose an improved SMD strategy by introducing the deep denoising convolutional neural networks (DnCNN) into the image preprocessing to improve the robustness of SMD. Results of the numerical simulations demonstrate that the strategy proposed exhibits superior performance compared to the traditional SMD technique in terms of both the root-mean-square error (RMSE) of phase estimates and the structural similarity (SSIM) of image reconstruction. In view of the superiority and robustness, the method we proposed may have important application prospects in multi-aperture imaging systems. [ABSTRACT FROM AUTHOR]

The Arbitrary Lagrangian–Eulerian (ALE) formulation provides a high-efficiency approach to simulate the moving contact behaviors in mechanical systems using the relative movement between material points and mesh nodes. Two approaches have been widely adopted to obtain the governing equations of ALE elements, namely (i) Lagrange's equations for non-material volume and (ii) the principle of virtual work. Indeed, consistent numerical results should be obtained through these two approaches; however, their mathematical expressions are quite different at first glance. In this paper, the equivalence of the above-mentioned two approaches demonstrated analytically for a general case and a specific example of three-dimensional two-node ALE cable elements. Additionally, the existence and disappearance conditions for additional terms L 1 and L 2 of the generalized inertial forces, which distinguish the ALE formulation from the Lagrangian formulation, are explicitly presented. They are physically caused by the material flow through the boundary and mathematically caused by the dependence of the mass matrix M on the material coordinates p 1 and p 2 . When no mass is transported through the boundary surface or the kinetic energy of the material points flowing into or out of the control volume is zero, L 1 and L 2 automatically disappear, and the governing equations degenerate to the classical form of Lagrange's equations. Finally, an example of preloaded wire rope with variable length is used to verify the above conclusions. [ABSTRACT FROM AUTHOR]

In drilling engineering, it is extremely challenging to drill a prescribed wellbore over several thousand meters. One of the main difficulties arises from accurately predicting and controlling the directional drilling performance, caused by the complex nonlinear dynamics of the slender drilling assembly and its interactions with the surrounding rocks. Nowadays, the simplified analytical geometry method, which has been adopted as the industry standard, can merely offer a rough estimation of the drilling direction, while the high-accuracy finite element method is computationally inefficient. This study is intended to provide a straightforward prediction of the drilling direction for a long drilling distance accurately and efficiently by proposing a dynamical simulation method based on the flexible multibody approach. Three techniques were adopted to achieve the critical objective of the paper. First, an Arbitrary Lagrangian–Eulerian formulation was used to provide a new approach to balance the efficiency and accuracy. Additionally, it can perfectly simulate the realistic drilling operation that drill pipes are continuously added to the drill string one by one through dynamically inserting new beam elements into the existing model. Second, the whole drill string and its interaction with the wellbore were all considered to carry out a high-fidelity simulation. Finally, the bit–rock interaction model was introduced to offer a straightforward way of evaluating the steerability of drilling assemblies. The presented method and model were validated by the consistency between the simulated wellbore trajectory and the in-field experimental data and are ready to be applied in drilling tools design, real-time drilling simulation, and drilling direction control. [ABSTRACT FROM AUTHOR]

Acquisition, tracking, and pointing (ATP) is a key technology in free space laser communication that has a characteristically high precision. In this paper, we report the acquisition and tracking of low-Earth-orbit satellites using shipborne ATP and verify the feasibility of establishing optical links between laser communication satellites and ships in the future. In particular, we developed a shipborne ATP system for satellite-to-sea applications in laser communications. We also designed an acquisition strategy for satellite-to-sea laser communication. In addition, a method was proposed for improving shipborne ATP pointing error. We tracked some stars at sea, achieving a pointing accuracy of less than 180μrad.We then acquired and tracked some low-Earth-orbit satellites at sea, achieving a tracking accuracy of about 20μrad. The results achieved in this work experimentally demonstrate the feasibility of ATP in satellite-to-sea laser communications. [ABSTRACT FROM AUTHOR]