Energy Efficient Wireless Sensor Network Modelling Based on Complex Networks

The power consumption and energy efficiency of wireless sensor network are the significant problems in Internet of Things network. In this paper, we consider the network topology optimization based on complex network theory to solve the energy efficiency problem of WSN. We propose the energy efficient model of WSN according to the basic principle of small world from complex networks. Small world network has clustering features that are similar to that of the rules of the network but also has similarity to random networks of small average path length. It can be utilized to optimize the energy efficiency of the whole network. Optimal number of multiple sink nodes of the WSN topology is proposed for optimizing energy efficiency. Then, the hierarchical clustering analysis is applied to implement this clustering of the sensor nodes and pick up the sink nodes from the sensor nodes as the clustering head. Meanwhile, the update method is proposed to determine the sink node when the death of certain sink node happened which can cause the paralysis of network. Simulation results verify the energy efficiency of the proposed model and validate the updating of the sink nodes to ensure the normal operation of the WSN

IvyCross: A Privacy-Preserving and Concurrency Control Framework for Blockchain Interoperability

Interoperability is a fundamental challenge for long-envisioned blockchain applications. A mainstream approach is to use Trusted Execution Environment (TEEs) to support interoperable off-chain execution. However, this incurs multiple TEEs configured with non-trivial storage capabilities running on fragile concurrent processing environments, rendering current strategies based on TEEs far from practical. The purpose of this paper is to fill this gap and design a practical interoperability mechanism with simplified TEEs as the underlying architecture. Specifically, we present IvyCross, a TEE-based framework that achieves low-cost, privacy-preserving, and race-free blockchain interoperability. Specifically, IvyCross allows running arbitrary smart contracts across heterogenous blockchains atop only two distributed TEE-powered hosts. We design an incentive scheme based on smart contracts to stimulate the honest behavior of two hosts, bypassing the requirement of the number of TEEs and large memory storage. We examine the conditions to guarantee the uniqueness of the Nash Equilibrium via Sequential Game Theory. Furthermore, a novel extended optimistic concurrency control protocol is designed to guarantee the correctness of concurrent execution of off-chain contracts. We formally prove the security of IvyCross in the Universal Composability framework and implement a proof-of-concept prototype atop Bitcoin, Ethereum, and FISCO BOCS. The experiments indicate that (i) IvyCross is able to support privacy-preserving and multiple-round smart contracts for cross-chain communication; (ii) IvyCross successfully decreases the off-chain costs on storage and communication of a TEE without using complex cryptographic primitives; and (iii) the total on-chain transaction fees in cross-chain communication are relatively low, within ranges of 0.2 USD ~ 1 USD

Distribution and Clinical Significance of Th17 Cells in the Tumor Microenvironment and Peripheral Blood of Pancreatic Cancer Patients

This study was designed to investigate the distribution of Th17 cells in the tumor microenvironment and peripheral blood of pancreatic cancer patients, its clinical significance, and the expression profile of Th17 cell-associated cytokines. The percentage of Th17 cells detected by flow cytometry analysis (FACS) was significantly higher in 46 pancreatic tumor tissues (5.28 ± 1.65%) compared with corresponding adjacent normal tissues (2.57 ± 0.83%) (P = 0.031). In addition, the percentage of Th17 cells was significantly higher in stage III-IV tumors than stage I-II tumors (P = 0.039). The percentage of Th17 cells in peripheral blood of 20 pancreatic cancer patients (3.99 ± 1.15%) was significantly higher than 15 healthy volunteers (1.98 ± 0.57%) (P = 0.027). Immunohistochemistry (IHC) was performed to detect IL-17+ cells in 46 pancreatic tumor tissues, as well as expression of CD34 in 24 tumor tissues. IL-17 was shown to mainly locate in cytoplasm, and the frequency of IL-17+ cells in tumor tissues (39/46) was higher than control (29/46). The presence of IL-17+ cells in tumor tissues was associated with tumor, node, and metastasis (TNM) stage, and lymph node metastasis (P = 0.012 and P = 0.009) but not with patient sex, age, tumor size, and histological grade (P > 0.05). Interestingly, distribution of Th17 cells in tumor tissues was positively correlated with microvessel density (MVD) (r = 0.86, P = 0.018). Furthermore, the median survival time of patients with high and low level of IL-17+ cells frequency was 14.5 and 18.5 months respectively (P = 0.023). The serum levels of Th17 cell-associated cytokines, IL-17 and IL-23 in 20 pancreatic patients detected by enzyme-linked immunosorbent assay (ELISA) were 69.2 ± 28.5 pg/mL and 266.5 ± 98.1 pg/mL, respectively, which were significantly higher than 15 healthy volunteers (P = 0.015 and P = 0.02). Moreover, levels of IL-17 and IL-23 were significantly higher in stage III-IV tumors than stage I-II tumors (P = 0.04 and P = 0.036). This study suggests that increase in Th17 cells frequency and its related cytokines levels in pancreatic tumor tissues may indicate involvement in the invasion and metastasis of pancreatic cancer, which may thereby affect patient prognosis. Therefore, Th17 cells and related cytokines may be served as important immune indicators for predicting the prognosis of pancreatic cancer patients

Similarities and Differences in Chinese and Caucasian Adults' Use of Facial Cues for Trustworthiness Judgments

All cultural groups in the world place paramount value on interpersonal trust. Existing research suggests that although accurate judgments of another's trustworthiness require extensive interactions with the person, we often make trustworthiness judgments based on facial cues on the first encounter. However, little is known about what facial cues are used for such judgments and what the bases are on which individuals make their trustworthiness judgments.In the present study, we tested the hypothesis that individuals may use facial attractiveness cues as a “shortcut” for judging another's trustworthiness due to the lack of other more informative and in-depth information about trustworthiness. Using data-driven statistical models of 3D Caucasian faces, we compared facial cues used for judging the trustworthiness of Caucasian faces by Caucasian participants who were highly experienced with Caucasian faces, and the facial cues used by Chinese participants who were unfamiliar with Caucasian faces. We found that Chinese and Caucasian participants used similar facial cues to judge trustworthiness. Also, both Chinese and Caucasian participants used almost identical facial cues for judging trustworthiness and attractiveness.The results suggest that without opportunities to interact with another person extensively, we use the less racially specific and more universal attractiveness cues as a “shortcut” for trustworthiness judgments

Convergence properties for arrays of rowwise pairwise negatively quadrant dependent random variables

summary:In this paper the authors study the convergence properties for arrays of rowwise pairwise negatively quadrant dependent random variables. The results extend and improve the corresponding theorems of T. C. Hu, R. L. Taylor: On the strong law for arrays and for the bootstrap mean and variance, Int. J. Math. Math. Sci 20 (1997), 375–382

On the strong convergence for weighted sums of negatively superadditive dependent random variables

Abstract In this article, some strong convergence results for weighted sums of negatively superadditive dependent random variables are studied without assumption of identical distribution. The results not only generalize the corresponding ones of Cai (Metrika 68:323-331, 2008) and Sung (Stat. Pap. 52:447-454, 2011), but also extend and improve the corresponding one of Chen and Sung (Stat. Probab. Lett. 92:45-52, 2014)

A note on the complete convergence for sequences of pairwise NQD random variables

Abstract In this paper, complete convergence and strong law of large numbers for sequences of pairwise negatively quadrant dependent (NQD) random variables with non-identically distributed are investigated. The results obtained generalize and extend the relevant result of Wu (Acta. Math. Sinica. 45(3), 617-624, 2002) for sequences of pairwise NQD random variables with identically distributed. 2000 MSC: 60F15.</p

Minimum-Throughput Maximization for Multi-UAV-Enabled Wireless-Powered Communication Networks

This paper considers a wireless-powered communication network (WPCN) system that uses multiple unmanned aerial vehicles (UAVs). Ground users (GUs) first harvest energy from a mobile wireless energy transfer (WET) UAV then use the energy to power their information transmission to a data gatherer (DG) UAV. We aim to maximize the minimum throughput for all GUs by jointly optimizing UAV trajectories, and the resource allocation of ET UAV and GUs. Because of the non-convexity of the formulated problem, we propose an alternating optimization algorithm, applying successive convex optimization techniques to solve the problem; the UAV trajectories and resource allocation are alternately optimized in each iteration. Numerical results show the efficiency of the proposed algorithm in different scenarios