On testing concurrent systems through contexts of queues

Concurrent systems, including asynchronous circuits, computer networks, and multi-threaded programs, have important applications, but they are also very complex and expensive to test. This thesis studies how to test concurrent systems through contexts consisting of queues. Queues, modeling buffers and communication delays, are an integral part of the test settings for concurrent systems. However, queues can also distort the behavior of the concurrent system as observed by the tester, so one should take into account the queues when defining conformance relations or deriving tests. On the other hand, queues can cause state explosion, so one should avoid testing them if they are reliable or have already been tested. To solve these problems, we propose two different solutions. The first solution is to derive tests using some test selection criteria such as test purposes, fault coverage, and transition coverage. The second solution is to compensate for the problems caused by the queues so that testers do not discern the presence of the queues in the first place. Unifying the presentation of the two solutions, we consider in a general testing framework partial specifications, various contexts, and a hierarchy of conformance relations. Case studies on test derivation for asynchronous circuits, communication protocols, and multi-threaded programs are presented to demonstrate the applications of the results

Can social interaction-oriented content trigger viewers' purchasing and gift-giving behaviors? Evidence from live-streaming commerce

Purpose: This study investigates how social interaction-oriented content in broadcasters' live speech affects broadcast viewers' purchasing and gift-giving behaviors and how broadcaster popularity moderates social interaction-oriented content's effect on the two different behaviors in live-streaming commerce. Design/methodology/approach: A research model was proposed and empirically tested using a panel data set collected from 537 live streams via Douyin (the Chinese version of TikTok), one of the most popular live broadcast platforms in China. A fixed-effects negative binomial regression model was used to examine the proposed research model. Findings: This study's results show that social interaction-oriented content in broadcasters' live speech has an inverted U-shaped relationship with broadcast viewers' purchasing behavior and shares a positive linear relationship with viewers' gift-giving behavior. Furthermore, broadcaster popularity significantly moderates the effect of social interaction-oriented content on viewers' purchasing and gift-giving behaviors. Originality/value: This research enriches the literature on live-streaming commerce by investigating how social interaction-oriented content in broadcasters' live speech affects broadcast viewers' product-purchasing and gift-giving behaviors from the perspective of broadcast viewers' attention. Moreover, this study provides some practical guidelines for developing live speech content in the live-streaming commerce context.publishedVersionPeer reviewe

The effects of fear of missing out on social media posting preferences

Purpose: Fear of missing out (FOMO) has become a common phenomenon on social media. This study aims to examine how FOMO influences consumer preferences for posting about identity-relevant products on social media. Design/methodology/approach: In this research, three studies were conducted to explore the effects of FOMO in different real-life situations. Study 1 was conducted in a laboratory setting in China. Study 2 includes two experiments, one that was conducted in China and one in the USA. Study 3 was conducted in a workplace setting in China. Findings: The results of Study 1 indicate that when consumers experience FOMO, they prefer to post about identity-relevant (vs functional) products to a greater extent than usual. Study 2 examines the role of self-esteem and identifies self-presentation and the avoidance of social attention as underlying mechanisms. Thus, consumers with high (or low) self-esteem tend to be more motivated to present themselves positively (or to avoid social attention) when experiencing FOMO. Furthermore, Study 3 reveals the moderating role of supportive interactions; that is, the interaction between FOMO and consumer self-esteem is most likely to exert an effect when consumers receive many supportive interactions. Research limitations/implications: This research demonstrates that posting identity-relevant content on social media is a coping strategy that individuals may adopt when experiencing FOMO. Moreover, self-esteem can predict how individuals cope with FOMO by identifying self-presentation and avoidance of social attention as the mechanisms underlying effects. Although this research attempts to avoid interference from other factors between in the relationship FOMO and the control conditions, it seems possible that more socially relevant information may be presented in the FOMO condition. Practical implications: Because FOMO can be manipulated and posting types can be predicted, this research provides important implications for brands on how to create or post content to better engage consumers. Originality/value: This research supports the role of FOMO as a driver of on consumer posting preferences on social media.Peer reviewe

Quantum Neuronal Sensing of Quantum Many-Body States on a 61-Qubit Programmable Superconducting Processor

Classifying many-body quantum states with distinct properties and phases of matter is one of the most fundamental tasks in quantum many-body physics. However, due to the exponential complexity that emerges from the enormous numbers of interacting particles, classifying large-scale quantum states has been extremely challenging for classical approaches. Here, we propose a new approach called quantum neuronal sensing. Utilizing a 61 qubit superconducting quantum processor, we show that our scheme can efficiently classify two different types of many-body phenomena: namely the ergodic and localized phases of matter. Our quantum neuronal sensing process allows us to extract the necessary information coming from the statistical characteristics of the eigenspectrum to distinguish these phases of matter by measuring only one qubit. Our work demonstrates the feasibility and scalability of quantum neuronal sensing for near-term quantum processors and opens new avenues for exploring quantum many-body phenomena in larger-scale systems.Comment: 7 pages, 3 figures in the main text, and 13 pages, 13 figures, and 1 table in supplementary material

Experimental quantum computational chemistry with optimised unitary coupled cluster ansatz

Simulation of quantum chemistry is one of the most promising applications of quantum computing. While recent experimental works have demonstrated the potential of solving electronic structures with variational quantum eigensolver (VQE), the implementations are either restricted to nonscalable (hardware efficient) or classically simulable (Hartree-Fock) ansatz, or limited to a few qubits with large errors for the more accurate unitary coupled cluster (UCC) ansatz. Here, integrating experimental and theoretical advancements of improved operations and dedicated algorithm optimisations, we demonstrate an implementation of VQE with UCC for H_2, LiH, F_2 from 4 to 12 qubits. Combining error mitigation, we produce high-precision results of the ground-state energy with error suppression by around two orders of magnitude. For the first time, we achieve chemical accuracy for H_2 at all bond distances and LiH at small bond distances in the experiment. Our work demonstrates a feasible path towards a scalable solution to electronic structure calculation, validating the key technological features and identifying future challenges for this goal.Comment: 8 pages, 4 figures in the main text, and 29 pages supplementary materials with 16 figure

Microorganism-mediated synthesis of chemically difficult-to-synthesize Au nanohorns with excellent optical properties in the presence of hexadecyltrimethylammonium chloride

Fundamental Research Funds for Central Universities [2010121051]; NSFC [21106117, 21036004]Closely packed, size-controllable and stable Au nanohorns (AuNHs) that are difficult to synthesize through pure chemical reduction are facilely synthesized using a microorganism-mediated method in the presence of hexadecyltrimethylammonium chloride (CTAC). The results showed that the size of the as-synthesized AuNHs could be tuned by adjusting the dosage of the Pichia pastoris cells (PPCs). The initial concentrations of CTAC, ascorbic acid (AA) and tetrachloroaurate trihydrate (HAuCl4 center dot 3H(2)O) significantly affected the formation of the AuNHs. Increasing the diameters of AuNHs led to a red shift of the absorbance bands around 700 nm in their UV-vis-NIR spectra. Interestingly, the AuNH/PPC composites exhibited excellent Raman enhancement such that rhodamine 6G with concentration as low as (10(-9) M) could be effectively detected. The formation process of the AuNHs involved the initial binding of the Au ions onto the PPCs with subsequent reduction by AA to form supported Au nanoparticles (AuNPs) based on preferential nucleation and initial anisotropic growth on the platform of the PPCs. The anisotropic growth of these AuNPs, which was influenced by CTAC and PPCs, resulted in the formation of growing AuNHs, while the secondary nucleation beyond the PPCs produced small AuNPs that were subsequently consumed through Ostwald ripening during the aging of the AuNHs. This work exemplifies the fabrication of novel gold nanostructures and stable bio-Au nanocomposites with excellent optical properties by combining microorganisms and a surfactant

On queued testing and its application to delay-insensitive systems

The thesis elaborates a so-called queued testing framework for input/output transition systems (IOTS) and demonstrates its applicability to delay-insensitive (DI) systems. IOTS are an appropriate model of systems with concurrent input and output, such as distributed systems and asynchronous circuits. We develop the queued testing framework based on the assumption that output of IOTS cannot be blocked. For this, a tester is separated into two independent processes: one applies stimuli and the other observes responses of a system under test through finite queues. We apply queued testing to DI systems, concurrent systems that are invariant under communication delays. As we prove, however, most DI systems are not robust, which means that not all input actions are acceptable (specified) in each state. The theorem is proved for a unified formalization of DI systems that considers a wide range of delay models: single-capacity buffers, queues, stacks, etc. To test DI systems, we extend the queued testing framework, which is originally elaborated for fully specified IOTS, to cover partially specified IOTS by preventing testers from sending unspecified input actions. Case studies in the thesis demonstrate that the extended queued testing framework is applicable to DI systems

Disentangling the impact of temperature on consumers' attitudes toward nostalgic advertising

https://doi.org/10.1111/ijcs.12815Abstract Although the effect of temperature on consumers is ubiquitous, little is known about how temperature affects consumers' attitudes toward nostalgic advertising. Drawing on embodied cognition theory, this study explores the effect of temperature on consumers' attitudes toward nostalgic advertising through the mediator of the affective system. Based on two experiments involving personal and historical nostalgic advertising, our results show that when exposed to comfortable temperature, consumers follow the ?assimilative effect? of temperature; warm temperatures trigger more positive attitudes toward nostalgic advertising when compared with cool temperatures. However, when exposed to uncomfortable temperatures, consumers follow the ?complementary effect? of temperatures; cold temperatures lead to more positive attitudes toward nostalgic advertising than hot temperatures. Furthermore, the affective system plays a mediating role between temperature and consumers' attitudes toward nostalgic advertising. This study contributes to the literature on temperature in marketing and provides a practical guide for companies to implement nostalgic advertising strategies.Peer reviewe