18 research outputs found
Managerial Overconfidence and Capital Structure: Evidence from China
Abstract
This paper used a modified Profit Forecasting Method, that is, the forecasted net profit growth rate attributable to shareholders of the parent company is subtracted from the actual forecasted net profit growth rate attributable to shareholders of the parent company, to measure the overconfidence degree of corporate management quantitatively. A panel data regression was conducted using data from A-share listed companies traded in the Chinese market between 2010 and 2019. The results of the empirical test show that overconfident managers are more inclined to use debt financing, and managerial overconfidence is significantly and positively related to a firm's capital structure. Through further analysis, this paper also found that the impact of managerial overconfidence on the capital structure of firms is varied for firms that belong to different industries. Among all the 13 industries analysed, 6 industries showed a positive effect of overconfidence on capital structure, 1 industry showed a negative effect on capital structure and the results for the remaining industries were not significant
ProlificDreamer: High-Fidelity and Diverse Text-to-3D Generation with Variational Score Distillation
Score distillation sampling (SDS) has shown great promise in text-to-3D
generation by distilling pretrained large-scale text-to-image diffusion models,
but suffers from over-saturation, over-smoothing, and low-diversity problems.
In this work, we propose to model the 3D parameter as a random variable instead
of a constant as in SDS and present variational score distillation (VSD), a
principled particle-based variational framework to explain and address the
aforementioned issues in text-to-3D generation. We show that SDS is a special
case of VSD and leads to poor samples with both small and large CFG weights. In
comparison, VSD works well with various CFG weights as ancestral sampling from
diffusion models and simultaneously improves the diversity and sample quality
with a common CFG weight (i.e., ). We further present various improvements
in the design space for text-to-3D such as distillation time schedule and
density initialization, which are orthogonal to the distillation algorithm yet
not well explored. Our overall approach, dubbed ProlificDreamer, can generate
high rendering resolution (i.e., ) and high-fidelity NeRF with
rich structure and complex effects (e.g., smoke and drops). Further,
initialized from NeRF, meshes fine-tuned by VSD are meticulously detailed and
photo-realistic. Project page and codes:
https://ml.cs.tsinghua.edu.cn/prolificdreamer/Comment: NeurIPS 2023 (Spotlight
Distributed Non-Convex Optimization with Sublinear Speedup under Intermittent Client Availability
Federated learning is a new distributed machine learning framework, where a
bunch of heterogeneous clients collaboratively train a model without sharing
training data. In this work, we consider a practical and ubiquitous issue when
deploying federated learning in mobile environments: intermittent client
availability, where the set of eligible clients may change during the training
process. Such intermittent client availability would seriously deteriorate the
performance of the classical Federated Averaging algorithm (FedAvg for short).
Thus, we propose a simple distributed non-convex optimization algorithm, called
Federated Latest Averaging (FedLaAvg for short), which leverages the latest
gradients of all clients, even when the clients are not available, to jointly
update the global model in each iteration. Our theoretical analysis shows that
FedLaAvg attains the convergence rate of ,
achieving a sublinear speedup with respect to the total number of clients. We
implement FedLaAvg along with several baselines and evaluate them over the
benchmarking MNIST and Sentiment140 datasets. The evaluation results
demonstrate that FedLaAvg achieves more stable training than FedAvg in both
convex and non-convex settings and indeed reaches a sublinear speedup
Hypoxic acclimatization training improves the resistance to motion sickness
ObjectiveVestibular provocation is one of the main causes of flight illusions, and its occurrence is closely related to the susceptibility of motion sickness (MS). However, existing training programs have limited effect in improving the resistance to motion sickness. In this study, we investigated the effects of hypoxia acclimatization training (HAT) on the resistance to motion sickness.MethodsHealthy military college students were identified as subjects according to the criteria. MS model was induced by a rotary chair. Experimental groups included control, HAT, 3D roller training (3DRT), and combined training.ResultsThe Graybiel scores were decreased in the HAT group and the 3DRT group and further decreased in the combined training group in MS induced by the rotary chair. Participants had a significant increase in blood pressure after the rotary chair test and a significant increase in the heart rate during the rotary chair test, but these changes disappeared in all three training groups. Additionally, LFn was increased, HFn was decreased, and LF/HF was increased accordingly during the rotary chair test in the control group, but the changes of these three parameters were completely opposite in the three training groups during the rotary chair test. Compared with the control group, the decreasing changes in pupillary contraction velocity (PCV) and pupillary minimum diameter (PMD) of the three training groups were smaller. In particular, the binocular PCV changes were further attenuated in the combined training group.ConclusionOur research provides a possible candidate solution for training military pilots in the resistance to motion sickness
Managerial Overconfidence and Capital Structure: Evidence from China
Abstract
This paper used a modified Profit Forecasting Method, that is, the forecasted net profit growth rate attributable to shareholders of the parent company is subtracted from the actual forecasted net profit growth rate attributable to shareholders of the parent company, to measure the overconfidence degree of corporate management quantitatively. A panel data regression was conducted using data from A-share listed companies traded in the Chinese market between 2010 and 2019. The results of the empirical test show that overconfident managers are more inclined to use debt financing, and managerial overconfidence is significantly and positively related to a firm's capital structure. Through further analysis, this paper also found that the impact of managerial overconfidence on the capital structure of firms is varied for firms that belong to different industries. Among all the 13 industries analysed, 6 industries showed a positive effect of overconfidence on capital structure, 1 industry showed a negative effect on capital structure and the results for the remaining industries were not significant
Efficient Catalytic Degradation of Phenol with Phthalocyanine-Immobilized Reduced GrapheneâBacterial Cellulose Nanocomposite
In this report, phthalocyanine (Pc)/reduced graphene (rG)/bacterial cellulose (BC) ternary nanocomposite, Pc-rGBC, was developed through the immobilization of Pc onto a reduced grapheneâbacterial cellulose (rGBC) nanohybrid after the reduction of biosynthesized graphene oxide-bacterial cellulose (GOBC) with N2H4. Field emission scanning electron microscopy (FESEM) and Fourier transform infrared spectroscopy (FT-IR) were employed to monitor all of the functionalization processes. The Pc-rGBC nanocomposite was applied for the treatment of phenol wastewater. Thanks to the synergistic effect of BC and rG, Pc-rGBC had good adsorption capacity to phenol molecules, and the equilibrium adsorption data fitted well with the Freundlich model. When H2O2 was presented as an oxidant, phenol could rapidly be catalytically decomposed by the Pc-rGBC nanocomposite; the phenol degradation ratio was more than 90% within 90 min of catalytic oxidation, and the recycling experiment showed that the Pc-rGBC nanocomposite had excellent recycling performance in the consecutive treatment of phenol wastewater. The HPLC result showed that several organic acids, such as oxalic acid, maleic acid, fumaric acid, glutaric acid, and adipic acid, were formed during the reaction. The chemical oxygen demand (COD) result indicated that the formed organic acids could be further mineralized to CO2 and H2O, and the mineralization ratio was more than 80% when the catalytic reaction time was prolonged to 4 h. This work is of vital importance, in terms of both academic research and industrial practice, to the design of Pc-based functional materials and their application in environmental purification
Differences in Milk Proteomic Profiles between Estrous and Non-Estrous Dairy Cows
Efficient reproductive management of dairy cows depends primarily upon accurate estrus identification. However, the currently available estrus detection methods, such as visual observation, are poor. Hence, there is an urgent need to discover novel biomarkers in non-invasive bodily fluids such as milk to reliably detect estrus status. Proteomics is an emerging and promising tool to identify biomarkers. In this study, the proteomics approach was performed on milk sampled from estrus and non-estrus dairy cows to identify potential biomarkers of estrus. Dairy cows were synchronized and timed for artificial insemination, and the cows with insemination leading to conception were considered to be in estrus at the day of insemination (day 0). Milk samples of day 0 (estrus group) and day â3 (non-estrus group) from dairy cows confirming to be pregnant were collected for proteomic analysis using the tandem mass tags (TMT) proteomics approach. A total of 89 differentially expressed proteins were identified, of which 33 were upregulated and 56 were downregulated in the estrus milk compared with the non-estrus milk. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis showed that acetyl coenzyme A carboxylase α (ACACA), apolipoprotein B (APOB), NAD(P)H steroid dehydrogenase-like (NSDHL), perilipin 2 (PLIN2), and paraoxonase 1 (PON1) participated in lipid binding, lipid storage, lipid localization, and lipid metabolic process, as well as fatty acid binding, fatty acid biosynthesis, and fatty acid metabolism, and these processes are well documented to be related to estrus regulation. These milk proteins are proposed as possible biomarkers of estrus in dairy cows. Further validation studies are required in a large population to determine their potential as estrus biomarkers
Can Glacial SeaâLevel DropâInduced Gas Hydrate Dissociation Cause Submarine Landslides?
We conducted twoâdimensional numerical simulations to investigate the mechanisms underlying the strong spatiotemporal correlation observed between submarine landslides and gas hydrate dissociation due to glacial seaâlevel drops. Our results suggest that potential plastic deformation or slip could occur at localized and small scales in the shallowâwater portion of the gas hydrate stability zone (GHSZ). This shallowâwater portion of the GHSZ typically lies within the area enclosed by three points: the BGHSZâseafloor intersection, the seafloor at âŒ600 m below sea level (mbsl), and the base of the GHSZ (BGHSZ) at âŒ1,050 mbsl in lowâlatitude regions. The deep BGHSZ (>1,050 mbsl) could not slip; therefore, the entire BGHSZ was not a complete slip surface. Glacial hydrate dissociation alone is unlikely to cause largeâscale submarine landslides. Observed deepâwater (much greater than 600 mbsl) turbidites containing geochemical evidence of glacial hydrate dissociation potentially formed from erosion or detachment in the GHSZ pinchâout zone.
Plain Language Summary
Many submarine landslides spatiotemporally correlate with gas hydrate dissociation. However, direct mechanical evidence supporting whether the overpressure and deformation due to glacial seaâlevel dropâinduced hydrate dissociation are adequate for triggering submarine landslides is lacking. Here, we present twoâdimensional thermalâhydraulicâchemical and geomechanical models of a gasâhydrate system in response to glacial seaâlevel drops and conduct sensitivity analyses of the model behavior under a wide range of key conditions from a global perspective. Our simulations suggest that glacial hydrate dissociation might induce plastic deformation or slip at localized and small scales only possibly within the shallowâwater portion of the hydrate stability zone. The deep part (>1,050 m below sea level) of the bottom boundary of the hydrate stability zone could not slip; therefore, the entire bottom boundary of the hydrate stability zone was not a complete slip surface. We demonstrate that glacial hydrate dissociation alone is unlikely to trigger largeâscale submarine landslides. Our work highlights the vicinity of the upper limit of the hydrate stability zone (where the base of the hydrate stability zone intersects the seafloor) as an important area for investigating overpressure and focused fluid flow, localized plastic deformation or slip, and downslope sediment transport related to glacial hydrate dissociation.
Key Points
Glacial hydrate dissociation might cause potential plastic deformation or slip at localized and small scales in shallow parts of the GHSZ
The large deformation surface at the BGHSZ boundary of the potential plastic deformation zone was not a complete slip surface
Glacial seaâlevel dropâinduced gas hydrate dissociation alone is unlikely to have caused largeâscale submarine landslide
Temperature and Humidity Regulate Sporulation of Corynespora cassiicola That Is Associated with Pathogenicity in Cucumber (Cucumis sativus L.)
Cucumber target leaf spot, caused by Corynespora cassiicola, is an emerging disease with a high incidence that causes severe damage to cucumbers on a global scale. Therefore, efforts need to be undertaken to limit the spread and infection of this pathogen, preferably by using environmentally friendly methods. In this study, the effects of temperature and moisture on the sporulation of C. cassiicola were investigated in vitro and in vivo. The novelty of our study refers to the observation of spore production and size as well as the revelation of a correlation between spore size and virulence. On potato dextrose agar (PDA) and cucumber−leaf extract agar (CEA), temperature played a critical role in spore production, which was strongly influenced by both temperature and moisture on detached leaves and cucumber seedlings. Maximum spore production was found at 30 °C on PDA and 25 °C on CEA, cucumber detached leaves and living plants. Lower spore productions were observed with a stepwise change of 5 °C. In addition, the largest spore production was found at 100% relative humidity (RH) in comparison to the other tested moisture. Moreover, moisture was found to be the most important factor affecting spore size, accounting for 83.09–84.86% of the total variance in length and 44.72–73.10% of the total variance in width. The longest−narrowest spores were formed at 100% RH, and the shortest−widest spores were formed at 75% RH. Furthermore, the result showed that larger spores of C. cassiicola were more virulent and small spores were avirulent. Our findings will contribute to the development of new strategies for the effective alleviation and control of cucumber target leaf spot