Energy efficiency task scheduling for battery level-aware mobile edge computing in heterogeneous networks

Zhigang Xie,Xin Song,Jing Cao,Siyang Xu 한국전자통신연구원 2022 ETRI Journal Vol.44 No.5

This paper focuses on a mobile edge-computing-enabled heterogeneous network. A battery level-aware task-scheduling framework is proposed to improve the energy efficiency and prolong the operating hours of batterypowered mobile devices. The formulated optimization problem is a typical mixed-integer nonlinear programming problem. To solve this nondeterministic polynomial (NP)-hard problem, a decomposition-based taskscheduling algorithm is proposed. Using an alternating optimization technology, the original problem is divided into three subproblems. In the outer loop, task offloading decisions are yielded using a pruning search algorithm for the task offloading subproblem. In the inner loop, closed-form solutions for computational resource allocation subproblems are derived using the Lagrangian multiplier method. Then, it is proven that the transmitted power-allocation subproblem is a unimodal problem; this subproblem is solved using a gradient-based bisection search algorithm. The simulation results demonstrate that the proposed framework achieves better energy efficiency than other frameworks. Additionally, the impact of the battery level-aware scheme on the operating hours of battery-powered mobile devices is also investigated.

A renewable-energy-driven energy-harvesting-based task scheduling and energy management framework

Xie Zhigang,Song Xin 한국통신학회 2024 ICT Express Vol.10 No.1

Aiming to provide low-cost MEC services for mobile devices in areas without/lacking infrastructure, we propose a renewable-energy-driven energy-harvesting-based task scheduling and energy management framework. First, for mobile devices, the constructed energy consumption minimization problem is solved by an alternating-optimization-based algorithm. Then, we design an energy management algorithm based on sampling average approximation to derive the optimal charging/discharging strategies, number of energy storage units, and renewable energy utilization. The simulation results show that the proposed framework can significantly reduce the cost of MEC servers and prolong the working hours of mobile devices.

Stability/instability of the graphene reinforced nano-sized shell employing modified couple stress model

Zhigang Yao,Hui Xie,Yulei Wang 한국풍공학회 2021 Wind and Structures, An International Journal (WAS Vol.32 No.1

The current research deals with, stability/instability and cylindrical composite nano-scaled shell’s resonance frequency filled by graphene nanoplatelets (GPLs) under various thermal conditions (linear and nonlinear thermal loadings). The piece-wise GPL-reinforced composites’ material properties change through the orientation of cylindrical nano-sized shell’s thickness as the temperature changes. Moreover, in order to model all layers’ efficient material properties, nanomechanical model of Halpin-Tsai has been applied. A functionally modified couple stress model (FMCS) has been employed to simulate GPLRC nano-sized shell’s size dependency. It is firstly investigated that reaching the relative frequency’s percentage to 30% would lead to thermal buckling. The current study’s originality is in considering the multifarious influences of GPLRC and thermal loading along with FMCS on GPLRC nano-scaled shell’s resonance frequencies, relative frequency, dynamic deflection, and thermal buckling. Furthermore, Hamilton’s principle is applied to achieve boundary conditions (BCs) and governing motion equations, while the mentioned equations are solved using an analytical approach. The outcomes reveal that a range of distributions in temperature and other mechanical and configurational characteristics have an essential contribution in GPLRC cylindrical nano-scaled shell’s relative frequency change, resonance frequency, stability/instability, and dynamic deflection. The current study’s outcomes are practical assumptions for materials science designing, nano-mechanical, and micro-mechanical systems such as micro-sized sensors and actuators.

Supplement of High Protein-Enriched Diet Modulates the Diversity of Gut Microbiota in WT or PD-1H-Depleted Mice

( Yajun Xie ),( Ping Zhao ),( Zhigang Han ),( Wei Li ),( Dan Shi ),( Lei Xu ),( Qiying Yi ) 한국미생물생명공학회(구 한국산업미생물학회) 2021 Journal of microbiology and biotechnology Vol.31 No.2

Supplement of high-protein food plays an important role in improving the symptoms of malnutrition and the immune capacity of the body, but the association of high-protein diet and gut microbiota remained unaddressed. Here, we systematically analyzed the internal organs and gut microbiota in C57(WT) or PD-1H-depleted (KO) mice (T cells were activated) fed with pupae or feed for six weeks. We observed that the body weight gain in the mice fed with pupae increased less significantly than that of the feed group, while the villi and small intestine lengths in the pupa group were reduced compared with that of mice given feed. However, the average body weight of the KO mice increased compared with that of the WT mice fed with pupae or feed. Pupae increased the concentration of blood glucose in WT, but not in KO mice. Moreover, in the feed group, there was no difference in the weight of the internal organs between the WT and KO mice, but in the pupae-fed group, liver weight was decreased and spleen weight was increased compared with that of KO mice. The amounts/plural/amounts of Melainabacteria, Chloroflexi, and Armatimonadetes were specifically upregulated by pupae, and this upregulation was weakened or eliminated by PD-1H depletion. Some bacteria with high abundance in the feed-fed KO mice, such as Deferribacteres, Melainabacteria, Acidobacteria, Bacteroidetes, Spirochaetes and Verrucomicrobia, were decreased in pupae-fed KO mice, and Proteobacteria and Deinococcus were specifically enriched in pupae-fed KO mice. Bacteroidetes, Firmicutes and Akkermansia were associated with weight loss in the pupaefed group while Lachnospiraceae and Anaerobiospirillum were related glucose metabolism and energy consumption. Based on high-throughput sequencing, we discovered that some gut bacteria specifically regulated the metabolism of a high-protein diet, and PD-1H deficiency improved life quality and sustained blood glucose. Moreover, PD-1H responses to high-protein diet through modulating the type and quantity of gut bacteria. These findings provide evidence about the association among gut microbiota, T cell activation (for PD-1H depletion) and high-protein diet metabolism, have important theoretical significance for nutrition and health research.

A Cloud-Edge Collaborative Computing Task Scheduling and Resource Allocation Algorithm for Energy Internet Environment

( Xin Song ),( Yue Wang ),( Zhigang Xie ),( Lin Xia ) 한국인터넷정보학회 2021 KSII Transactions on Internet and Information Syst Vol.15 No.6

To solve the problems of heavy computing load and system transmission pressure in energy internet (EI), we establish a three-tier cloud-edge integrated EI network based on a cloud-edge collaborative computing to achieve the tradeoff between energy consumption and the system delay. A joint optimization problem for resource allocation and task offloading in the three-tier cloud-edge integrated EI network is formulated to minimize the total system cost under the constraints of the task scheduling binary variables of each sensor node, the maximum uplink transmit power of each sensor node, the limited computation capability of the sensor node and the maximum computation resource of each edge server, which is a Mixed Integer Non-linear Programming (MINLP) problem. To solve the problem, we propose a joint task offloading and resource allocation algorithm (JTOARA), which is decomposed into three subproblems including the uplink transmission power allocation sub-problem, the computation resource allocation sub-problem, and the offloading scheme selection sub-problem. Then, the power allocation of each sensor node is achieved by bisection search algorithm, which has a fast convergence. While the computation resource allocation is derived by line optimization method and convex optimization theory. Finally, to achieve the optimal task offloading, we propose a cloud-edge collaborative computation offloading schemes based on game theory and prove the existence of Nash Equilibrium. The simulation results demonstrate that our proposed algorithm can improve output performance as comparing with the conventional algorithms, and its performance is close to the that of the enumerative algorithm.

Overexpression of miR-191 Predicts Poor Prognosis and Promotes Proliferation and Invasion in Esophageal Squamous Cell Carcinoma

Xiaotian Gao,Zeqing Song,Zhanqiang Xie,Zhigang Wang,Keluo Cheng,Ke Liang 연세대학교의과대학 2017 Yonsei medical journal Vol.58 No.6

Purpose: Accumulating evidence has shown that dysregulation of microRNA-191 (miR-191) is closely associated with tumorigenesisand progression in a wide range of cancers. This study aimed to explore the potential role of miR-191 in esophageal squamous cell carcinoma (ESCC). Materials and Methods: miR-191 expression was assessed in 93 ESCC tissue specimens by real-time polymerase chain reaction, and survival analysis was performed via Kaplan-Meier and Cox regression analyses. 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide, plate colony-forming, BrdU, and Transwell assays were conducted to observe the effect of miR-191 on ESCC proliferation and invasion. Luciferase reporter and western blot assays were taken to identify target genes of miR-191. Results: miR-191 was overexpressed in 93 cases of ESCC, compared with adjacent normal tissues, and miR-191 expression was significantly related to differentiation, depth of invasion, TNM stage, lymph node metastasis, and distant metastasis of tumor. Kaplan-Meier and Cox regression analyses demonstrated that overexpression of miR-191 was an independent and significant predictorof ESCC prognosis. Both gain-of-function and loss-of-function experiments showed that miR-191 promoted ESCC cell proliferation and invasion activities in vitro. Early growth response 1 (EGR1), a tumor suppressor, was predicted as a direct target of miR-191. Luciferase reporter and western blot assays proved that miR-191 reduced EGR1 expression by directly binding its 3' untranslated region. Moreover, EGR1 knockdown by siRNA enhanced ESCC cell growth and invasion. Conclusion: Our findings provide specific biological roles of miR-191 in ESCC survival and progression. Targeting the novel miR-191/EGR1 axis represents a potential new therapeutic way to block ESCC development.

Energy Efficiency Maximization for Energy Harvesting Bidirectional Cooperative Sensor Networks with AF Mode

( Siyang Xu ),( Xin Song ),( Lin Xia ),( Zhigang Xie ) 한국인터넷정보학회 2020 KSII Transactions on Internet and Information Syst Vol.14 No.6

This paper investigates the energy efficiency of energy harvesting (EH) bidirectional cooperative sensor networks, in which the considered system model enables the uplink information transmission from the sensor (SN) to access point (AP) and the energy supply for the amplify-and-forward (AF) relay and SN using power-splitting (PS) or time-switching (TS) protocol. Considering the minimum EH activation constraint and quality of service (QoS) requirement, energy efficiency is maximized by jointly optimizing the resource division ratio and transmission power. To cope with the non-convexity of the optimizations, we propose the low complexity iterative algorithm based on fractional programming and alternative search method (FAS). The key idea of the proposed algorithm first transforms the objective function into the parameterized polynomial subtractive form. Then we decompose the optimization into two convex sub-problems, which can be solved by conventional convex programming. Simulation results validate that the proposed schemes have better output performance and the iterative algorithm has a fast convergence rate.

Health diagnosis of permanent magnets under different cooling system effectiveness in high‑speed permanent magnet motors for electric vehicles

Meiwei Zhang,Weili Li,Wanlu Xie,Haoyue Tang,Zhigang Wu 전력전자학회 2023 JOURNAL OF POWER ELECTRONICS Vol.23 No.3

The power density of a high-speed permanent magnet (PM) motor is high, and the heat dissipation of its rotor is poor due to limited installation space. Th0000000000000000000us, the temperature of the permanent magnets is high. Once the cooling system of a motor becomes ineffective and the rotor temperature exceeds the limit temperature of the PM material, a demagnetization fault of the PM occur, which seriously affects the performance of the PM motor. To ensure the safe and reliable operation of PM motors, a method to diagnose the PM health is presented in this paper. The demagnetization ratio of the PM can be diagnosed quantitatively by its temperature. In this paper, the relationship between the temperature and the demagnetization ratio of a PM is obtained through thermal demagnetization tests, and the threshold temperature of demagnetization is given. Then, the health of a PM under different effectiveness of the cooling system in a high-speed PM motor is researched. Finally, the calculation results are verified by temperature tests of a high-speed PM motor.

Cooperative encryption over backscatter: Secure green communication for two-way energy harvesting relay networks

Siyang Xu,Xin Song,Suyuan Li,Jing Cao,Jiahui Zhu,Zhigang Xie 한국통신학회 2023 ICT Express Vol.9 No.3

This paper focuses on the design of a novel cooperative jamming strategy and resource allocation scheme in two-way energy harvesting (EH) relay networks. For solving the security vulnerability challenges, a backscatter jamming strategy is proposed by leveraging the information signals as the carrier, which can degrade the eavesdropping link without extra energy consumption, delay and strict synchronization requirement. Based on the above design, we formulate the secure energy efficiency (SEE) maximization problem by jointly optimizing the transmission powers of two sources, two different power splitting (PS) factors and time allocation factor. Although the resulting optimization problem is highly non-convex due to fractional objective function and multivariate coupling, an iterative algorithm is developed to convert the original problem into a tractable version and obtain the resource allocation solutions. Simulation results show that the achievable SEE of the proposed scheme is better than other conventional schemes.

Electric-Field-Assisted Assembly of Polymer-Tethered Gold Nanorods in Cylindrical Nanopores

Wang, Ke,Jin, Seon-Mi,Xu, Jiangping,Liang, Ruijing,Shezad, Khurram,Xue, Zhigang,Xie, Xiaolin,Lee, Eunji,Zhu, Jintao American Chemical Society 2016 ACS NANO Vol.10 No.5

<P>In this report, we demonstrate the confined assembly of polymer-tethered gold nanorods in anodic aluminum oxide (AAO) channels with the assistance of electric field (EF). Various interesting hybrid assemblies, such as single-, double-, triple-, or quadruple-helix, linear, and hexagonally packed structures are obtained by adjusting pore size in AAO channels, ligand length, and EF orientation. Correspondingly, surface plasmonic property of the assemblies can thus be tuned. This strategy, by coupling of external-field and cylindrically confined assembly, is believed to be a promising approach for generating ordered hybrid assemblies with hierarchical structures, which may find potential applications in photoelectric devices, biosensors, and data storage devices.</P>