Secure Transmission Design With Feedback Compression for the Internet of Things

ARC Discovery Projects Grant DP150103905

Does CEO duality worsen or fosters audit quality: evidence from Chinese firms?

The objective of this study is to examine the role of CEO duality in audit quality of Chinese firms. To address the effect of CEO duality, this study considered four characteristics of CEO duality; corporate audit culture, audit committee independence, decision making through enormous power and single leadership. The indirect effect of audit committee decision is considered between CEO duality and audit quality. A questionnaire survey is carried out to collect primary data. A questionnaire was designed to collect data from Chinese firms. Respondents of the study were the CEO’s and directors of Chinese firms; therefore, questionnaires were distributed among them by using online survey. 135 valid questionnaires were used in data analyses which is carried out by using Partial Least Square (PLS)-Structural Equation Modeling (SEM). Results of the study highlighted that; CEO duality has both positive and negative effect on audit quality. Due to the single leadership style and supportive corporate audit culture, the audit quality may be improved. However, CEO duality influences negatively on audit committee independence which has negative effect on audit committee decisions. Similarly, CEO duality allows to enjoy enormous power which may affect negatively on the decision making. Thus, decision-making through enormous power has negative effect on audit committee decisions. Finally, while making the strategies to enhance audit quality, the practitioners can consider the important points highlighted by the current study to promote audit quality

Modelling and Linear Control of a Buoyancy-Driven Airship

International audienceWe describe the modelling and control of a newkind airship which is propelled by buoyancy. Based on the Newton-Euler equations and Kirchhoff equations, and referred to the models of underwater gliders and aircraft, a 6DOF nonlinear mathematical model of a buoyancy-driven airship is derived, with features distributed internal mass, and no thrust, elevators and rudders. The attitudes are controlled by the motion of internal mass. The performances of the airship are studied in the vertical plane. A linear feedback controller is derived for the nonlinear model. The results of simulation display robustness properties of the controllers to disturbances

A New Secure Transmission Scheme With Outdated Antenna Selection

We propose a new secure transmission scheme in the multi-input multi-output multi-eavesdropper wiretap channel. In this channel, the NA-antenna transmitter adopts transmit antenna selection (TAS) to choose the antenna that maximizes the instantaneous signal-to-noise ratio (SNR) at the receiver to transmit, while the NB-antenna receiver and the NE-antenna eavesdropper adopt maximal-ratio combining (MRC) to combine the received signals. We focus on the practical scenario where the channel state information (CSI) during the TAS process is outdated. In this scenario, we propose a new transmission scheme to prevent the detrimental effect of the outdated CSI on the wiretap codes design at the transmitter. To thoroughly assess the secrecy performance achieved by the proposed scheme, we derive new closed-form expressions for the exact secrecy outage probability and the probability of non-zero secrecy capacity for arbitrary SNRs. We also derive new compact expressions for the asymptotic secrecy outage probability at high SNRs. Notably, in the analysis we take spatial correlation at the receiver into consideration. Apart from the advantage of our scheme over the conventional TAS/MRC scheme, we demonstrate that the outdated TAS reduces the secrecy diversity order from NANB to NB. We also demonstrate that antenna correlation improves the secrecy performance at low SNR but deteriorates the secrecy performance at medium and high SNRs, by affecting the secrecy array gain only.ARC Discovery Projects Grant DP150103905