SOUND SOURCE LOCALIZATION OF DIGITAL HEARING AIDS USING WAVELET BASED MULTIVARIATE STATISTICAL METHOD

The letter proposed a sound source localization method of digital hearing aids using wavelet based multivariate statistics with the Generalized Cross Correlation (GCC) algorithm. Haar wavelet is used to decompose GCC sequences and extract four wavelet characteristics. And then, Hotelling T2 statistical method is used to fuse the four wavelet characteristics. The statistical value is used to judge the number of sound sources and obtain corresponding time delay estimation which is used to localize the position of sound source. The experimental results show that the proposed method has better robustness in an environment with severe noise and reverberation. Meanwhile, the complexity of al-gorithm is moderate, which is available for sound source localization of hearing aids.

Improving the resilience of maritime supply chains: The integration of ports and inland transporters in duopoly markets

The adverse impact of the outbreak of COVID-19 has reduced ports’ operational efficiency. In addition, ports and inland logistics providers are generally independent of each other and difficult to work together, which leads to time loss. Thus, as the core player, ports can integrate with inland logistics providers to improve the efficiency and resilience of maritime supply chains. This study examines the strategic options of two competing maritime supply chains consisting of ports and inland logistics providers. We investigate the impact of cooperation between ports and inland logistics providers and government regulation on the maritime supply chain by comparing members’ optimal pricing and overall social welfare under centralized, decentralized, and hybrid scenarios. Results indicate that the hybrid scenario is an equilibrium strategy for maritime supply chain, although this strategy is not optimal for governments seeking to improve supply chain resilience and maximize social welfare. Furthermore, observations show that through government economic intervention, both seaborne supplies can be incentivized to adopt an integrated strategy, and business and society can achieve a win–win situation.

Duopoly Competition Between Chauffeured Car and Taxi:An Analysis of Pricing and Market Segmentation

Chauffeured car service(CCS) has developed rapidly in recent years. Although CCS brings convenience and effectiveness, it also triggers some new problems like vicious competition. This work studies the duopoly competition between CCS company and taxi company, in terms of different average cost and number of vehicles of two companies. To find the solutions like the pricing scheme to ease the vicious competition, Hotelling model is introduced. The Hotelling-type model is used to present passengers’ preferences to the companies. Besides, failing situation is taken into account in the Hotelling model to describe the situation where passenger’s demand is not satisfied in reality. This work theoretically analyzes the price scheme and equilibrium market segmentation based on the average cost and number of vehicles of each company. Furthermore, companies’ profits, passengers’ utility and social welfare in equilibrium are revealed based on the game theory. The study shows that both of companies can get optimal profits by setting effective price scheme. The company which has higher price, definitely gets less market share. In addition, moderate competition can lead to positive influence on social welfare.

Coopetition between B2C E-commerce Companies:Price Competition and Logistics Service Cooperation

This paper studies the impact of logistics cooperation in two competing companies,one of which is equipped with a self-run logistics system while the other is not.The latter outsources logistics services to a third-party logistics company before logistics cooperation,or to its competitor after logistics cooperation with the client's service quality being in proportion to and no greater than the service provider's service quality.We find that when the service provider is a price taker,logistics cooperation is beneficial to both firms only when the service quality after logistics cooperation is moderate.Interestingly,under some circumstances,the client's profit increases even when its service quality decreases after logistics cooperation because logistics cooperation eases the price competition.We also find that all-win situations in which logistics cooperation increases the firms7 profit,consumer surplus and social welfare can be achieved.Finally,when the service price can be chosen by the service provider,we propose a negotiation process in which agreement on logistics cooperation can be reached;when the firm can invest in service quality,logistics cooperation may lower the equilibrium investment level.

Dividend or No Dividend in Delegated Blockchain Governance:A Game Theoretic Analysis

Delegated blockchain governance is the frontier of blockchain design issues that is to improve the scalability of blockchain networks.Delegated proof of stake(DPoS)blockchains such as EOS must select a few super nodes for transaction verification.In particular,the blockchain community has debated recently on whether dividend should be allowed when electing super nodes,which might be considered as unethical or unfair,leading to an open research topic and a new research gap that has theoretical value for both academia and industry.In this paper,we build a theoretical framework to study how dividend affects user decisions and welfare in a DPoS blockchain.Based on game theory,we propose a three-player Hotelling model with two policies to study the behaviors of voters and candidates.We first use a static game analysis to show that the benefits of dividend for voters and for candidates vary with the size of reward and there exists an interval,in which the zero dividend policy would be good for the welfare of both candidates and voters.Then,we use an evolutionary game analysis to examine the process dynamics of super node selection,we find that the campaign strategy of candidates has to do with the size of platform reward given to the candidates by the blockchain platform.Especially in the asymmetric case,we find that higher level of platform reward turns to benefit candidates with large number of votes even more.Our findings are instrumental for designing dividend policies in DPoS blockchains and can stimulate more potential research in blockchain governance.

REGIONAL CONTAINER PORT COMPETITION IN A DUAL GATEWAY-PORT SYSTEM

Many ocean transportation hub systems consist of two container ports that share the container handling business in the area. The container flow passing through a port is the main measurement of the port＇s competitiveness. In this paper we adopt a Hotelling model to study the container port competition in a so-called ＂dual gateway-port system＂. The system contains two ports and two terminals, one belonging to each port. The two governments in which the two ports are located compete on cargo fees and the two terminals determine service price and service quality. We study two models with different levels of competition between the terminals. In the ftrst model, the two terminals are owned by two different operators and in the second model, the two terminals are centralized under one operator. The second model exists in practice but is not well studied in the literature. We derive the cargo fee, terminal service price, and service quality equilibria for these two models. We investigate the competition outcome sensitivity with a numerical study. The numerical results reveal that governments prefer terminals to compete with each other. If the terminals do not have competitive advantages in their service quality, then terminal centralization brings more profits to the terminal operator than the competition case.