Offloading in Software Defined Network at Edge with Information Asymmetry: A Contract Theoretical Approach

The proliferation of highly capable mobile devices such as smartphones and tablets has significantly increased the demand for wireless access. Software defined network (SDN) at edge is viewed as one promising technology to simplify the traffic offloading process for current wireless networks. In this paper, we investigate the incentive problem in SDN-at-edge of how to motivate a third party access points (APs) such as WiFi and smallcells to offload traffic for the central base stations (BSs). The APs will only admit the traffic from the BS under the precondition that their own traffic demand is satisfied. Under the information asymmetry that the APs know more about own traffic demands, the BS needs to distribute the payment in accordance with the APs' idle capacity to maintain a compatible incentive. First, we apply a contract-theoretic approach to model and analyze the service trading between the BS and APs. Furthermore, other two incentive mechanisms: optimal discrimination contract and linear pricing contract are introduced to serve as the comparisons of the anti adverse selection contract. Finally, the simulation results show that the contract can effectively incentivize APs' participation and offload the cellular network traffic. Furthermore, the anti adverse selection contract achieves the optimal outcome under the information asymmetry scenario.Comment: 10 pages, 9 figure

Development and psychometric assessment of Health Action Process Approach (HAPA) in terms of smoking cessation among Chinese smokers

Abstract The Health Action Process Approach (HAPA) is a two-stage (pre-intentional and post-intentional) behavioral change model that distinguishes between motivation and volition in behavior change process. This study aims to develop HAPA-based assessments for smoking cessation among current smokers. The HAPA-based measures were developed and the draft measures included nine constructs, namely, risk perception in smoking-induced cancer, risk perception in smoking-induced systemic disease, positive outcome expectancy, negative outcome expectancy, self-efficacy in quitting smoking, self-efficacy in maintaining, self-efficacy in re-initiating, quitting planning and coping planning in smoking cessation, with a total of 26 items. A cross-sectional survey was conducted in China in 2022. Principal Component Analysis was used for Exploratory Factor Analysis (EFA). Cronbach’s α coefficient was calculated to evaluate the internal consistency. Variables such as severity of smoking addiction were selected to evaluate the correlation between the HAPA scale and these variables. Of the 928 participants, 76.4% (709/928) were male and the median age was 35 years. Five factors were extracted by EFA. The factor loadings of each item were all greater than 0.60, and the cumulative variance contribution rate was 90.15%. The Cronbach’s α coefficient of each HAPA-based subscales was 0.929–0.986. The HAPA-based measurements are comprehensive, reliable and valid in the assessment of smokers’ smoking cessation cognition, which can be used to guide the design and implementation of intervention and the development of theory

Offloading in Software Defined Network at Edge with Information Asymmetry: A Contract Theoretical Approach

The proliferation of highly capable mobile devices such as smartphones and tablets has significantly increased the demand for wireless access. Software defined network (SDN) at edge is viewed as one promising technology to simplify the traffic offloading process for current wireless networks. In this paper, we investigate the incentive problem in SDN-at-edge of how to motivate a third party access points (APs) such as WiFi and smallcells to offload traffic for the central base stations (BSs). The APs will only admit the traffic from the BS under the precondition that their own traffic demand is satisfied. Under the information asymmetry that the APs know more about own traffic demands, the BS needs to distribute the payment in accordance with the APs’ idle capacity to maintain a compatible incentive. First, we apply a contract-theoretic approach to model and analyze the service trading between the BS and APs. Furthermore, other two incentive mechanisms: optimal discrimination contract and linear pricing contract are introduced to serve as the comparisons of the anti adverse selection contract. Finally, the simulation results show that the contract can effectively incentivize APs’ participation and offload the cellular network traffic. Furthermore, the anti adverse selection contract achieves the optimal outcome under the information asymmetry scenario

Recent progress on the electromagnetic wave absorption of one-dimensional carbon-based nanomaterials

The rapid development of electronic information technology and the use of high-power electrical equipment have led to the increasingly serious problem of electromagnetic interference (EMI). Therefore, it is of great significance to study electromagnetic wave absorbing (EWA) materials with good absorbing properties. Compared with other wave absorbing materials, carbon-based nanomaterials such as silicon carbide (SiC), carbon nanotube (CNT), carbon nanowire (CNW) and carbon nanofiber (CNF) have the advantages of low density, large specific surface area/aspect ratio and excellent dielectric properties, which make them stand out. However, impedance mismatch caused by high conductivity and a single microwave loss mechanism seriously affect the absorption performance. In order to overcome the above shortcomings, surface modification, component control, structural design and other methods have been widely used in EWA materials in recent years to improve their absorption performance. In this review, we introduce the mechanism of microwave absorption and summarizes the research progress of one-dimensional carbon based nanomaterials and their composites. The preparation methods and microwave absorption properties of one-dimensional carbon based nanocomposites with different components, morphologies, and microstructures were discussed in detail. Finally, the challenges and future development prospects of one-dimensional carbon based nanomaterials were summarized, providing reference for the development of high-performance microwave absorbing materials

An Acetylene-Containing Perylene Diimide Copolymer for High Mobility n‑Channel Transistor in Air

A new solution-processable conjugated copolymer (<b>P1</b>) of perylene diimide (PDI) and dithienothiophene (DTT) incorporating acetylene spacers was synthesized by palladium(0)-catalyzed Sonogashira coupling reaction. Theory calculation reveals that introduction of rod-like ethynylene spacer in the polymer main chain promotes planarity and π-conjugation of the polymer main chain. Relative to the conjugated copolymer (<b>P2</b>) of PDI and DTT without acetylene spacers, polymer <b>P1</b> exhibits 0.1 eV down shift of LUMO level and 89 nm red shift of low-energy absorption band. Polymer <b>P1</b> in top-contact bottom-gate organic field-effect transistors (OFETs) exhibits a saturation electron mobility of 0.06 cm² V^–1 s^–1 in air, while <b>P2</b> does not function in the same device in air. Additionally, a saturation electron mobility of 0.075 cm² V^–1 s^–1 in air, and after six days storage in air, an electron mobility of 0.034 cm² V^–1 s^–1 were observed for <b>P1</b> in bottom-contact bottom-gate OFETs; while a saturation electron mobility of 0.038 cm² V^–1 s^–1 in air, and after six days storage in air, an electron mobility of 0.013 cm² V^–1 s^–1 were observed for <b>P2</b> in the same device. The better air stability and higher electron mobility of <b>P1</b> are attributed to densely ordered packing of the polymer chains excluding oxygen or water and the lower LUMO level of <b>P1</b>