5,629 research outputs found
Technological Regimes and Firm Survival: Evidence across Sectors and over Time
In addition to the usual variables representing firm- and industry-specific features that impact the firm’s survival, this paper uses three R&D related variables to reflect two Schumpeterian technological regimes: creative destruction (the entrepreneurial regime) and creative accumulation (the routinized regime). After controlling for age, size, entry barriers, capital intensity, the profit margin, the concentration ratio, the profit-cost ratio and entry rates, the empirical results confirm the theoretical relationship between technological regimes and the survival rate of new firms: new firms are more likely to survive under the entrepreneurial regime. Moreover, this effect is larger within the younger cohorts of firms than within the older ones.Firm Survival, Technological Regimes, Taiwanese Manufacturing
The Effects of Language Difference on Operational Performance and Satisfaction with B2B E-Marketplace Interface
This study integrated the user interface and information content of the business-to-business (B2B) electronic marketplace (e-marketplace) with language to analyze whether language differences affect the definition of good interface design and the information content that should be provided via an e-marketplace. An experimental design was adopted for collecting data from tasks, and then the Questionnaire for User Interface Satisfaction (QUIS) was used to ascertain how satisfied subjects were with regard to using the B2B e-marketplace interfaces. Study results showed that the language, the e-marketplace interface the subject used, and a combination of the two predict a person’s operational performance and satisfaction with a B2B e-marketplace. This study’s results provide a better understanding of whether B2B e-marketplace service providers should develop interfaces based on specific languages
Sparse4D: Multi-view 3D Object Detection with Sparse Spatial-Temporal Fusion
Bird-eye-view (BEV) based methods have made great progress recently in
multi-view 3D detection task. Comparing with BEV based methods, sparse based
methods lag behind in performance, but still have lots of non-negligible
merits. To push sparse 3D detection further, in this work, we introduce a novel
method, named Sparse4D, which does the iterative refinement of anchor boxes via
sparsely sampling and fusing spatial-temporal features. (1) Sparse 4D Sampling:
for each 3D anchor, we assign multiple 4D keypoints, which are then projected
to multi-view/scale/timestamp image features to sample corresponding features;
(2) Hierarchy Feature Fusion: we hierarchically fuse sampled features of
different view/scale, different timestamp and different keypoints to generate
high-quality instance feature. In this way, Sparse4D can efficiently and
effectively achieve 3D detection without relying on dense view transformation
nor global attention, and is more friendly to edge devices deployment.
Furthermore, we introduce an instance-level depth reweight module to alleviate
the ill-posed issue in 3D-to-2D projection. In experiment, our method
outperforms all sparse based methods and most BEV based methods on detection
task in the nuScenes dataset
Sparse4D v3: Advancing End-to-End 3D Detection and Tracking
In autonomous driving perception systems, 3D detection and tracking are the
two fundamental tasks. This paper delves deeper into this field, building upon
the Sparse4D framework. We introduce two auxiliary training tasks (Temporal
Instance Denoising and Quality Estimation) and propose decoupled attention to
make structural improvements, leading to significant enhancements in detection
performance. Additionally, we extend the detector into a tracker using a
straightforward approach that assigns instance ID during inference, further
highlighting the advantages of query-based algorithms. Extensive experiments
conducted on the nuScenes benchmark validate the effectiveness of the proposed
improvements. With ResNet50 as the backbone, we witnessed enhancements of
3.0\%, 2.2\%, and 7.6\% in mAP, NDS, and AMOTA, achieving 46.9\%, 56.1\%, and
49.0\%, respectively. Our best model achieved 71.9\% NDS and 67.7\% AMOTA on
the nuScenes test set. Code will be released at
\url{https://github.com/linxuewu/Sparse4D}
General approach of causal mediation analysis with causally ordered multiple mediators and survival outcome
Causal mediation analysis with multiple mediators (causal multi-mediation analysis) is critical in understanding why an intervention works, especially in medical research. Deriving the path-specific effects (PSEs) of exposure on the outcome through a certain set of mediators can detail the causal mechanism of interest. However, the existing models of causal multi-mediation analysis are usually restricted to partial decomposition, which can only evaluate the cumulative effect of several paths. Moreover, the general form of PSEs for an arbitrary number of mediators has not been proposed. In this study, we provide a generalized definition of PSE for partial decomposition (partPSE) and for complete decomposition, which are extended to the survival outcome. We apply the interventional analogues of PSE (iPSE) for complete decomposition to address the difficulty of non-identifiability. Based on Aalen’s additive hazards model and Cox’s proportional hazards model, we derive the generalized analytic forms and illustrate asymptotic property for both iPSEs and partPSEs for survival outcome. The simulation is conducted to evaluate the performance of estimation in several scenarios. We apply the new methodology to investigate the mechanism of methylation signals on mortality mediated through the expression of three nested genes among lung cancer patients
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