计量经济分析 = Econometric analysis

The science of the total environment

Investor Psychology and Security Market Under- and Overreactions

This paper solves explicitly a simple equilibrium model with liquidity risk. In our liquidityadjusted capital asset pricing model, a security s required return depends on its expected liquidity as well as on the covariances of its own return and liquidity with the market return and liquidity. In addition, a persistent negative shock to a security s liquidity results in low contemporaneous returns and high predicted future returns. The model provides a unified framework for understanding the various channels through which liquidity risk may affect asset prices. Our empirical results shed light on the total and relative economic significance of these channels and provide evidence of flight to liquidity. r 2005 Elsevier B.V. All rights reserved.

Market Liquidity: Asset Pricing with Liquidity Risk

Handbook of the Economics of Finance

Background: Perceived organizational support (POS) measures the employee perception of support from the organization and helps to understand the employer-employee relationship better. The aim of the study is to understand the healthcare professionals' perception of support from public health department and to examine thehealthcare professionals' difference in perception of support across various demographics variables. Methods: A survey is conducted among healthcare professionals including medical officers and staff nurses working in primary health centres (PHC) in the state of Tamilnadu. In the study, public health department refers to the Directorate of Public Health and Preventive Medicine. Mann Whitney U test and Kruskal Wallis H test are used to assess the difference in POS across demographic variables. Results: The results of the study indicated that the healthcare professionals perceive a moderate levelof support from public health department. The healthcare professionals' POS is found to differ across their age, role and total work experience but not across gender and work experience in the current PHC. Further, the POS of healthcare professionals is found to differ with respect to PHC location and does not differ with respect to PHC type. Conclusion: The results emphasize the need to enhance POS of healthcare professionals. The health policy makers and mangers have to consider the difference in POS of healthcare professionals and make amendments in the human resource policies related to selection and training.

Healthcare professionals' perspective of support from public health department: a study in the primary health centers of Tamil Nadu.

In agriculture, manual weed identification remains a challenge for farmers and agriculturalists. Recent technologies address the problem of weeds through several methods among which outlier detection is one powerful technique. Outlier detection is an effective weed identification method because it builds the model only by training the positive samples, hence known as one-class classification (OCC). In the context of agriculture, all crops except the target crop are considered to be weeds. This makes OCC a suitable method to identify weeds. In this work, we build OCC-IF-WD (One-Class Classification using Isolation Forest for Weed Detection) model that treats the target class as an inlier and all other classes as outliers. To train this model, an original dataset from Kaggle is used. Isolation Forest, which is a one-class classifier was used to build the model. OCC-IFWD recognizes maize as an inlier and all its associated weeds as outliers. The model was trained with 1082 images. The model was tested against various categories of outliers to examine its performance level. The results show the highest accuracy of 90.2% when the model is tested to differentiate between maize (inlier) and blackgrass (outlier). Also, a precision of 87%, recall of 94%, and Fl-score of 91% were recorded from the model.

Outlier detection in maize field using Isolation Forest: A one-class classifier

/pdf/walking-corpse-syndrome-n81mzd9u.pdf

Walking Corpse Syndrome

CAPTCHAs have become less effective in preventing automated bots from accessing internet services, owing to the increasing advancements in computer vision and machine learning. To overcome this challenge, this paper proposes a novel approach using Neural Style Transfer (NST) to generate complex and secure CAPTCHAs using VGG-16. Our approach produces visually challenging CAPTCHAs that are difficult for bots to identify and understand, thereby enhancing the security of internet services. The proposed approach utilizes a grid-like design, with 9 randomly selected images that are stylized using Neural Style Transfer, where the user is prompted to choose pictures that are visually similar to the separate images displayed. This not only makes the CAPTCHA more secure but also more user-friendly. We provide implementation details of our approach, including training and validation, and present experimental data demonstrating its efficacy in thwarting automated attacks. The proposed CAPTCHA system is not susceptible to similarity based attacks. The similarity index results returned the following values, MSE: 12934.04 RMSE:113.72 PSNR: 7.013. Our solution has the potential to provide internet services with higher levels of security against automated bots.

Guarding Against Bots with Art: NST-based Deep Learning Approach for CAPTCHA Verification

We examine how founder shareholders switch between alignment and entrenchment and thereby shape the value relevance impact of IFRS convergence. Using a sample of Indian firms adopting the IFRS converged standards in the first phase, we find that founder ownership affects the ability of IFRS to improve value relevance non-monotonically and this effect holds even after addressing the endogeneity concern in founder ownership. However, we find that the non-monotonic effect is limited to domestic owners and not foreign owners. Further analysis shows that the non-monotonic founder effect is present only in large-size firms and high-leverage firms which are experiencing higher equity adjustment post convergence. We also find that active(passive) institutional investors have a positive (negative) effect on the relationship between founder shareholding and IFRS impact suggesting that monitoring incentives rest with active investors and not passive investors. On solving for the turning points, we find that founders facilitate effective IFRS implementation only when they hold enough equity which qualifies as significant influence but not exceeding the super-majority level (around 60%), indicating an alignment effect. However, entrenchment prevails at extreme levels of founder shareholding leading to opportunistic IFRS implementation which deteriorates value relevance. Our results advocate that a minimum public shareholding at around 35% is desirable to promote financial transparency and disclosure. 

M. Thenmozhi

Papers

Healthcare professionals' perspective of support from public health department: a study in the primary health centers of Tamil Nadu.

Outlier detection in maize field using Isolation Forest: A one-class classifier

Walking Corpse Syndrome

Guarding Against Bots with Art: NST-based Deep Learning Approach for CAPTCHA Verification

Founder ownership and value relevance of IFRS convergence: Role of institutional investors