The event study methodology, which is gaining recognition in the business and marketing disciplines, is a technique used to capture the impact of significant events and announcements at the firm ...level and country level. Originating from the finance and economics disciplines, and being widely used in the finance literature, the method has recently attracted the attention of business and marketing researchers, particularly in the aftermath of Covid-19, which has adversely affected all kinds of businesses across the world. The event study methodology can be implemented to measure the impact of a major corporate announcement (e.g. new product development) or a significant event on corporate financial performance, profitability, and market valuation over a specific event window, such as a few days (a short window) or a few years (a long window). In this article, we provide a detailed explanation of the step-by-step procedure for implementing the event study methodology in STATA, using Covid-19-related death announcements from the United States, France, Spain, Italy, China, and the United Kingdom. We also provide STATA commands that can be used by researchers when implementing the event study methodology.
Smart cameras are key sensors in Internet of Things (IoT) applications and often capture highly sensitive information. Therefore, security and privacy protection is a key concern. This paper ...introduces a lightweight security approach for smart camera IoT applications based on elliptic-curve (EC) signcryption that performs data signing and encryption in a single step. We deploy signcryption to efficiently protect sensitive data onboard the cameras and secure the data transfer from multiple cameras to multiple monitoring devices. Our multi-sender/multi-receiver approach provides integrity, authenticity, and confidentiality of data with decryption fairness for multiple receivers throughout the entire lifetime of the data. It further provides public verifiability and forward secrecy of data. Our certificateless multi-receiver aggregate-signcryption protection has been implemented for a smart camera IoT scenario, and the runtime and communication effort has been compared with single-sender/single-receiver and multi-sender/single-receiver setups.
This article documents the hydro-magnetic, incompressible Jeffery-Hamel flow in convergent/divergent (CD) channels with stretchable walls. Although there seem to be several works on the subject in ...the available literature, only a few attempts have been made to work into mass and heat transfer analysis. Consequently, novelty of present study is to investigate the significance of Soret/Dufour. Joule heating, and chemical reaction effects on Jeffery-Hamel flow. The governing coupled system of PDEs showing the mathematical framework of the current physical problems is converted into ODEs through proper transformations. The numerical solution of the obtained couple of ODEs is simulated with the assistance of Mathematica-11 solver NDSolve. The computed outcomes depict that Lorentz force developed due to the magnetic field decays the fluid motion for both convergent and divergent channels. Furthermore, incorporating the heat source and Dufour effects yields a sustainable increase in temperature distribution, whereas the Soret number has reverse features on concentration. Furthermore, the numerical outcomes reflect the significant variation in Nusselt number against magnetic, radiation parameter and Soret number.
This paper studies the relationship between executive compensation and corporate performance of global energy companies. Data from 121 listed energy companies from 2010 to 2019 were collected for ...empirical analysis. The results show that in the energy industry, executive compensation has a significant positive impact on corporate performance, which is consistent with agency theory, tournament theory and social network theory. In addition, we found that cash incentives are more useful than equity incentives for senior executives. Therefore, we recommend that energy companies establish a reasonable compensation incentive system to address agency issues in the sector.
•Excessive executive compensation is of the major governance issue in energy sector.•We use multiple theoretical perspective to examine compensation-performance.•Our data consists of 121 global energy companies between 2010 and 2019.•Cash incentives are more useful than equity incentives in energy sector.
Exploiting Radio Frequency Identification (RFID) technology in healthcare systems has become a common practice, as it ensures better patient care and safety. However, these systems are prone to ...security vulnerabilities that can jeopardize patient privacy and the secure management of patient credentials. This paper aims to advance state-of-the-art approaches by developing more secure and private RFID-based healthcare systems. More specifically, we propose a lightweight RFID protocol that safeguards patients' privacy in the Internet of Healthcare Things (IoHT) domain by utilizing pseudonyms instead of real IDs, thereby ensuring secure communication between tags and readers. The proposed protocol has undergone rigorous testing and has been proven to be secure against various security attacks. This article provides a comprehensive overview of how RFID technology is used in healthcare systems and benchmarks the challenges faced by these systems. Then, it reviews the existing RFID authentication protocols proposed for IoT-based healthcare systems in terms of their strengths, challenges, and limitations. To overcome the limitations of existing approaches, we proposed a protocol that addresses the anonymity and traceability issues in existing schemes. Furthermore, we demonstrated that our proposed protocol had a lower computational cost than existing protocols and ensured better security. Finally, our proposed lightweight RFID protocol ensured strong security against known attacks and protected patient privacy using pseudonyms instead of real IDs.
In recent years, massive development in the malware industry changed the entire landscape for malware development. Therefore, cybercriminals became more sophisticated by advancing their development ...techniques from file-based to fileless malware. As file-based malware depends on files to spread itself, on the other hand, fileless malware does not require a traditional file system and uses benign processes to carry out its malicious intent. Therefore, it evades conventional detection techniques and remains stealthy. This paper briefly explains fileless malware, its life cycle, and its infection chain. Moreover, it proposes a detection technique based on feature analysis using machine learning for fileless malware detection. The virtual machine acquired the memory dumps upon executing the malicious and non-malicious samples. Then the necessary features are extracted using the Volatility memory forensics tool, which is then analyzed using machine learning classification algorithms. After that, the best algorithm is selected based on the k-fold cross-validation score. Experimental evaluation has shown that Random Forest outperforms other machine learning classifiers (Decision Tree, Support Vector Machine, Logistic Regression, K-Nearest Neighbor, XGBoost, and Gradient Boosting). It achieved an overall accuracy of 93.33% with a True Positive Rate (TPR) of 87.5% at zeroFalse Positive Rate (FPR) for fileless malware collected from five widely used datasets (VirusShare, AnyRun, PolySwarm, HatchingTriage, and JoESadbox).
In smart home environments, the interaction between a remote user and devices commonly occurs through a gateway, necessitating the need for robust user authentication. Despite numerous ...state-of-the-art user-authentication schemes proposed over the years, these schemes still suffer from security vulnerabilities exploited by the attackers. One severe physical attack is the node capture attack, which allows adversaries to compromise the security of the entire scheme. This research paper advances the state of the art by conducting a security analysis of user-authentication approaches regarding their vulnerability to node capture attacks resulting in revelations of several security weaknesses. To this end, we propose a secure user-authentication scheme to counter node capture attacks in smart home environments. To validate the effectiveness of our proposed scheme, we employ the BAN logic and ProVerif tool for verification. Lastly, we conduct performance analysis to validate the lightweight nature of our user-authentication scheme, making it suitable for IoT-based smart home environments.
Internet of Things (IoT) comprises of large number of smart devices that can exchange sensed data by availing online services. Smart devices can directly interact with the human beings for sensing ...the healthcare parameters and transmitting to a central repository. During the data exchange, it is mandatory to secure the messages between sender and receiver to handle the malicious human based attacks. For providing secure communication, a number of signature-based schemes are explored in literature but smart devices need more lightweight operations by ensuring desired security strengths. The main problem during signature based approaches is the computational overhead due to large real numbers required for signature and verification processes. This paper presents a light weight shortened complex digital signature algorithm for providing secure communication between smart devices in human centered IoT. We have used less extensive operations to achieve signature and verification processes like human beings do signatures on legal documents and verify later as per witness. We have also presented a multi-option parameter selection to use a signature-verification pair of expressions at particular index by adopting the common practice of human beings for using different signatures as per document criticality level. It enhances the security strength to guard against traffic analysis attacks. We have developed an experimental setup where a number of cell phones and smart devices are considered for secure communication using existing and proposed digital signature schemes. Results demonstrate the supremacy of our scheme as compared to preliminaries.
This study investigates the thermal energy and reactive processes on nanomaterial flow via convergent/divergent channels. The research looks at how varied channel designs, fluid characteristics, and ...operating conditions affect flow patterns, temperature distributions, and heat transfer rates. The study focuses on the heat transfer mechanisms within the channels and the effect of exothermic/endothermic reactive processes on fluid flow and temperature profiles. The findings provide vital insights into the behavior of such flow systems, aiding in the comprehension of heat transfer phenomena and prospective applications in engineering domains such as energy systems, chemical processes, and aeronautical engineering.
Endogeneity issues in empirical research have received increasing academic attention. Tackling endogeneity problems effectively and using the appropriate estimation techniques are important quality ...benchmarks in the publication process of many academic journals. In this paper, we discuss the use of instrumental variables (IVs) in business and marketing research, with a particular focus on its implementation in STATA. We discuss several pre- and postestimation tests that researchers can use to implement various versions of IVs in STATA, including two-stage least squares regression, limited information maximum likelihood estimation, and generalized method of moments.
PDF
