On Two-Pair Two-Way Relay Channel with an Intermittently Available Relay

When multiple users share the same resource for physical layer cooperation such as relay terminals in their vicinities, this shared resource may not be always available for every user, and it is critical for transmitting terminals to know whether other users have access to that common resource in order to better utilize it. Failing to learn this critical piece of information may cause severe issues in the design of such cooperative systems. In this paper, we address this problem by investigating a two-pair two-way relay channel with an intermittently available relay. In the model, each pair of users need to exchange their messages within their own pair via the shared relay. The shared relay, however, is only intermittently available for the users to access. The accessing activities of different pairs of users are governed by independent Bernoulli random processes. Our main contribution is the characterization of the capacity region to within a bounded gap in a symmetric setting, for both delayed and instantaneous state information at transmitters. An interesting observation is that the bottleneck for information flow is the quality of state information (delayed or instantaneous) available at the relay, not those at the end users. To the best of our knowledge, our work is the first result regarding how the shared intermittent relay should cooperate with multiple pairs of users in such a two-way cooperative network.Comment: extended version of ISIT 2015 pape

Influence of migration policy risk on international market segmentation: analysis of housing and rental markets in the euro area

This paper aims to discuss the influence of migration policy risk on market segmentation of housing and rental markets in the Euro Area. Policy risk is represented by the Migration Policy Uncertainty Index (MPUI) and Migration Fear Index (MFI) of Germany and the United Kingdom; in this study, whether these indexes influence the interaction between the housing and rental markets of the two countries and euro-area countries was examined. The empirical results showed that the influence of the United Kingdom’s migration policy risk on the euro-area countries is higher than that of Germany. The United Kingdom’s MPUI and MFI significantly contribute to the influence of the United Kingdom’s housing market on other markets except for Belgium and Spain. Compared with housing market connectedness, the rental market connectedness is less influenced by migration policy risk and migration fear. This may be because variables related to short-term residence policies influence the rental market. The high policy risk is more likely to influence decisions related to long-term house purchase, but not those related to short-term residence. Finally, this study found that the higher the uncertainty of the migration policies of the United Kingdom and Germany is, the higher the house market segmentation is

Career Anchors, National Culture and Leave Intent of MIS Professionals in Taiwan

This study focuses on the career anchors of MIS professionals and adopts the well-established career theory, Schein\u27s Career Anchors, as the fundamental theory in this study. The present paper attempts to investigate the relationship between career anchors and leave intent of MIS professionals in Taiwan. The study adds the cultural construct, Chinese Relationalism, into its research model, in order to comprehend the role of Chinese Relationalism in the context of the career anchor model. Three career anchors: technical competence, autonomy, and entrepreneurship, have direct (negative or positive) and significant impacts on the intents of MIS professionals to leave their employment. This study establishes that Chinese Relationalism impacts on the technical competence, geographical security, identity, lifestyle, and various career anchors of MIS professionals and also moderates the relationships between autonomy, entrepreneurship and the leave intent of MIS professionals in Taiwan

Quantum Annealing Approach for the Optimal Real-time Traffic Control using QUBO

Traffic congestion is one of the major issues in urban areas, particularly when traffic loads exceed the roads capacity, resulting in higher petrol consumption and carbon emissions as well as delays and stress for road users. In Asia, the traffic situation can be further deteriorated by road sharing of scooters. How to control the traffic flow to mitigate the congestion has been one of the central issues in transportation research. In this study, we employ a quantum annealing approach to optimize the traffic signals control at a real-life intersection with mixed traffic flows of vehicles and scooters. Considering traffic flow is a continuous and emerging phenomenon, we used quadratic unconstrained binary optimization (QUBO) formalism for traffic optimization, which has a natural equivalence to the Ising model and can be solved efficiently on the quantum annealers, quantum computers or digital annealers. In this article, we first applied the QUBO traffic optimization to artificially generated traffic for a simple intersection, and then we used real-time traffic data to simulate a real Dongda-Keyuan intersection with dedicated cars and scooter lanes, as well as mixed scooter and car lanes. We introduced two types of traffic light control systems for traffic optimization C-QUBO and QUBO. Our rigorous QUBO optimizations show that C-QUBO and QUBO outperform the commonly used fixed cycle method, with QUBO outperforming C-QUBO in some instances. It has been found that QUBO optimization significantly relieves traffic congestion for the unbalanced traffic volume. Furthermore, we found that dynamic changes in traffic light signal duration greatly reduce traffic congestion.Comment: 2021 IEEE/ACIS 22nd International Conference on Software Engineering, Artificial Intelligence, Networking and Parallel/Distributed Computing (SNPD), 24-26 November 202

Atom-centered potentials for describing London dispersion forces in density functional theory

The Kohn-Sham formulation of density functional theory (DFT) has posed itself as one of the most popular and versatile methods for condensed phase studies owing to its reasonable accuracy and affordable computational cost. DFT, in principle, yields exact ground state energy, including dispersion forces that are of primordial importance in chemical and biological systems. Yet with many exchange-correlation functionals in practical use such as the local density approximation or generalized gradient approximations, DFT either provides sporadic results or fails completely to account for these forces. In consequence, various methods offering remedy for this shortcoming have been proposed in this active field of research. In particular, dispersion-corrected atom-centered potentials (DCACPs) serve as a robust and efficient way to include these weak forces in a fully self-consistent manner within current DFT frameworks. The aim of this thesis is twofold: first, to improve the predictive power and the understanding of the DCACP concept; second, applying DCACPs to systems of increasing complexity starting with dimers, continuing through larger clusters and ending with the condensed phase. The success of the second aim not only justifies the use of DCACPs but more importantly, provides insights to the role dispersion forces play in the systems investigated. We first draw on the atoms-in-molecules theory and a multi-center density expansion to justify the form and universality of DCACPs. A library of DCACPs calibrated with an improved penalty functional against high-level ab initio references is presented. With the library in hand, we extend our studies to systems of biological significance, mainly constituents of proteins and DNA; polycyclic aromatic molecules intercalated in between segments of DNA are the center of focus. The application of DCACPs is then furthered to the condensed phase and the importance of van der Waals interactions in liquid water is investigated

The Transformation of Journalism in Taiwan and its Democratic Functions

This research focuses on the transformation of journalism in Taiwan, a post-authoritarian society, with a specific focus on its democratic function. While previous research concentrated on the early stages of change after the authoritarian regime collapsed, democratisation has been a continuous process. Taiwan is a pertinent case providing empirical evidence of the role journalism plays in a new democracy's move from transitional to consolidating stages. This research explores the dynamic changes in print journalism, including a consideration of the assumed Asian trait in journalism - Confucian culture - and the impact of social media in Taiwan's hybrid media system. The study addresses a wide range of concerns related to these dynamics, aiming to shed light on the evolution of print journalism after democratisation. A multi-method approach is used, which includes analysing data from semi-structured interviews with twenty-three journalists and analysing political news from Taiwan's four national newspapers in 2008 and 2020 as well as their corresponding Facebook pages. By taking a longitudinal approach that considers the changing landscape of journalism over time, across print and social media platforms, and through different generations of journalists, this thesis provides a nuanced and holistic understanding of the transformation of journalism in Taiwan. Challenging the notion that Confucian culture directly applies to Taiwan's journalistic landscape, the research proposes alternative interpretations emerging within Taiwan's distinctive partisan media system, such as the concept of social harmony. Unlike Western concepts, Taiwan's partisanship assumes a unique meaning, with dominant ideologies of unification and independence rather than the usual dimensions of left and right political ideologies. In the post-democratic era, a hybrid form of journalism emerges, and the partisan media system evolves. Print newspapers strive to exert political influence and fulfil democratic roles; while their online counterparts, particularly Facebook pages, mainly serve informational and entertainment functions, unable to replace the significance of print editions. This study not only emphasises the ongoing transformation of print journalism in serving democracy but also reveals the impending crisis of print journalism's democratic function