Scheduling with machine-learning-based flow detection for packet-switched optical data center networks

Wang, Lin,Wang, Xinbo,Tornatore, Massimo,Kim, Kwang Joon,Kim, Sun Me,Kim, Dae-Ub,Han, Kyeong-Eun,Mukherjee, Biswanath IEEE 2018 Journal of optical communications and networking Vol.10 No.4

<P>A scalable, low-latency, high-speed, and energy- efficient data center network is a key element in the deployment of future large-scale data centers, and photonic switching has recently been recognized as a promising solution to fulfill these goals. In this study, we present a packet-switched optical network (PSON) architecture with centralized control for intra-data-center connectivity. For efficient PSON operation, intelligent yet low-complexity bandwidth-scheduling algorithms are critical. To align with realistic traffic flows in a data center, we consider “mice flow,” which occurs frequently but carries a small number of bytes, and “elephant flow,” which occurs occasionally but has a huge number of bytes. To classify traffic flows with different characteristics, we investigate various machine-learning (classification) techniques, such as C4.5 and Naïve Bayes Discretization, and compare their performance in terms of accuracy and classification speed. We also develop a priority-aware scheduling algorithm for packet switching, which is optimized for PSON, and is adaptive to flow classification under a dynamic traffic scenario. Numerical simulations show that our proposed scheduling algorithm assisted by flow-classification techniques can outperform a benchmark algorithm in terms of average delay and packet-loss ratio.</P>

Energy-Efficient Virtual Base Station Formation in Optical-Access-Enabled Cloud-RAN

Xinbo Wang,Thota, Saigopal,Tornatore, Massimo,Hwan Seok Chung,Han Hyub Lee,Soomyung Park,Mukherjee, Biswanath IEEE 2016 IEEE journal on selected areas in communications Vol.34 No.5

<P>In recent years, the increasing traffic demand in radio access networks (RANs) has led to considerable growth in the number of base stations (BSs), posing a serious scalability issue, including the energy consumption of BSs. Optical-access-enabled Cloud-RAN (CRAN) has been recently proposed as a next-generation access network. In CRAN, the digital unit (DU) of a conventional cell site is separated from the radio unit (RU) and moved to the 'cloud' (DU cloud) for centralized signal processing and management. Each DU/RU pair exchanges bandwidth-intensive digitized baseband signals through an optical access network (fronthaul). Time-wavelength division multiplexing (TWDM) passive optical network (PON) is a promising fronthaul solution due to its low energy consumption and high capacity. In this paper, we propose and leverage the concept of a virtual base station (VBS), which is dynamically formed for each cell by assigning virtualized network resources, i.e., a virtualized fronthaul link connecting the DU and RU, and virtualized functional entities performing baseband processing in DU cloud. We formulate and solve the VBS formation (VF) optimization problem using an integer linear program (ILP). We propose novel energy-saving schemes exploiting VF for both the network planning stage and traffic engineering stage. Extensive simulations show that CRAN with our proposed VF schemes achieves significant energy savings compared to traditional RAN and CRAN without VF.</P>

Dexamethasone enhances glucose uptake by SGLT1 and GLUT1 and boosts ATP generation through the PPP-TCA cycle in bovine neutrophils

Xinbo Wang,Mingyu Tang,Yuming Zhang,Yansong Li,Jingdong Mao,Qinghua Deng,Shusen Li,Zhenwei Jia,Liyin Du 대한수의학회 2022 Journal of Veterinary Science Vol.23 No.5

Background: Clinical dexamethasone (DEX) treatment or stress in bovines results in extensive physiological changes with prominent hyperglycemia and neutrophils dysfunction. Objectives: To elucidate the effects of DEX treatment in vivo on cellular energy status and the underlying mechanism in circulating neutrophils. Methods: We selected eight-month-old male bovines and injected DEX for 3 consecutive days (1 time/d). The levels of glucose, total protein (TP), total cholesterol (TC), and the proinflammatory cytokines interleukin (IL)-1β, IL-6 and tumor necrosis factor (TNF)-α in blood were examined, and we then detected glycogen and adenosine triphosphate (ATP) content, phosphofructosekinase-1 (PFK1) and glucose-6-phosphate dehydrogenase (G6PDH) activity, glucose transporter (GLUT)1, GLUT4, sodium/glucose cotransporter (SGLT)1 and citrate synthase (CS) protein expression and autophagy levels in circulating neutrophils. Results: DEX injection markedly increased blood glucose, TP and TC levels, the Ca2+/P5+ ratio and the neutrophil/lymphocyte ratio and significantly decreased blood IL-1β, IL-6 and TNF-α levels. Particularly in neutrophils, DEX injection inhibited p65-NFκB activation and elevated glycogen and ATP contents and SGLT1, GLUT1 and GR expression while inhibiting PFK1 activity, enhancing G6PDH activity and CS expression and lowering cell autophagy levels. Conclusions: DEX induced neutrophils glucose uptake by enhancing SGLT1 and GLUT1 expression and the transformation of energy metabolism from glycolysis to pentose phosphate pathway (PPP)-tricarboxylic acid (TCA) cycle. This finding gives us a new perspective on deeper understanding of clinical anti-inflammatory effects of DEX on bovine.

Virtualized Cloud Radio Access Network for 5G Transport

Wang, Xinbo,Cavdar, Cicek,Wang, Lin,Tornatore, Massimo,Chung, Hwan Seok,Lee, Han Hyub,Park, Soo Myung,Mukherjee, Biswanath IEEE 2017 IEEE communications magazine Vol.55 No.9

<P>Current radio access networks (RANs) need to evolve to handle diverse service requirements coming from the growing number of connected devices and increasing data rates for the upcoming 5G era. Incremental improvements on traditional distributed RANs cannot satisfy these requirements, so the novel and disruptive concept of a cloud RAN (CRAN) has been proposed to decouple digital units (DUs) and radio units (RUs) of base stations (BSs), and centralize DUs into a central office, where virtualization and cloud computing technologies are leveraged to move DUs into the cloud. However, separating RUs and DUs requires low-latency and high-bandwidth connectivity links, called 'fronthaul,' as opposed to traditional backhaul links. Hence, design of the 5G transport network, that is, the part of the network that carries mobile data traffic between BSs and the core network and data centers, is key to meet the new 5G mobile service requirements and effectively transport the fronthaul traffic. Today, consensus is yet to be achieved on how the fronthaul traffic will be transported between RUs and DUs, and how virtualization of network resources will occur from a radio network segment to the centralized baseband processing units. In this article, we present a new 5G architecture, called virtualized cloud radio access network (V-CRAN), moving toward a cell-less 5G network architecture. We leverage the concept of a virtualized BS (V-BS) that can be optimally formed by exploiting several enabling technologies such as software defined radio (SDR) and coordinated multipoint (CoMP) transmission/reception. A V-BS can be formed on a per-cell basis or per-user basis by allocating virtualized resources on demand. For the fronthaul solution, our approach exploits the passive optical network (PON), where a wavelength can be dynamically assigned and shared to form a virtualized passive optical network (VPON). Several use cases of the V-CRAN are presented to show how network architecture evolution can enhance system throughput, energy efficiency, and mobility management.</P>

Multi-objective optimization modification of a tooth surface with minimum of flash temperature and vibration acceleration RMS

Xigui Wang,Yongmei Wang,Yixiang Liu,Xinbo Zhang,Dayu Zheng 대한기계학회 2018 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.32 No.7

The minimum of tooth surface flash temperature and vibration acceleration RMS design is proposed and analyzed. The tooth contact analysis (TCA) and the load tooth contact analysis (LTCA) method and multi-objective optimization are also detailed. Satisfying design variables in multiple physical quantities leads to the minimum of multi-objective optimization. Considering the tooth surface loading conditions are uniform or not, the optimal modification of the tooth surface for improving gear comprehensive characteristics under various load bearing conditions is improved. The tooth surface flash temperature and vibration acceleration root mean square (RMS) values in different transmission modes of marine ship power rear gears drive system are derived. This research considers the multi-objective optimization modifications of tooth surface, and its main purpose is to propose an approach to help design tooth corrections to simultaneously optimize several objective physical quantities.

Dynamic bandwidth and wavelength allocation scheme for next-generation wavelength-agile EPON

Lin Wang,Xinbo Wang,Tornatore, Massimo,Hwan Seok Chung,Han Hyub Lee,Soomyung Park,Mukherjee, Biswanath IEEE 2017 Journal of optical communications and networking Vol.9 No.3

<P>Recently, the IEEE 802.3 Ethernet Working Group has classified three architectures for the nextgeneration Ethernet passive optical network (NG-EPON). They are called single-scheduling domain (SSD) PON, multi-scheduling domain (MSD) PON, and wavelength-agile (WA) PON, and they differ based on how a group of optical network units (ONUs) share awavelength. Existing dynamic bandwidth and wavelength allocation (DBWA) schemes for conventional EPON can be applied to MSD-PON and SSDPON, but not WA-PON. This is because WA-PON is a new architecture with full flexibility where a flexible number of wavelengths can be assigned to one ONU, and multiple ONUs can transmit at the same time. In this work, we develop a mathematical model and a novel DBWA scheme for transmission scheduling in WA-PON. However, as WA-PON incurs penalties in terms of delay and power consumption when an ONU activates its transmissions on new wavelengths, a trade-off between energy saving and data-transfer latency reduction needs to be carefully addressed when performing transmission scheduling. So, we develop a power-consumption model and modify the proposed DBWA scheme to enhance the energy efficiency ofWA-PON. Finally, we conduct simulation experiments for performance evaluation of the three PON architectures in terms of latency and packet loss ratio.We quantitatively investigate the influence of various parameters, such as the number of ONU transceivers and ONU buffer size, onWA-PON latency and packet loss ratio, and we evaluate the energy efficiency gain of the modified DBWA scheme.</P>

Study on Wheel-Side Drive System with a Single Trailing Arm

Wang Bin,Chen Xinbo,Lyu Hongming,Niu Xinwei 한국자동차공학회 2021 International journal of automotive technology Vol.22 No.5

In order to reduce unsprung mass and ensure driving comfortability, a novel electrical vehicle (EV) drive system, which integrated the wheel-side reducer and a single trailing arm, was studied in this paper. Firstly, the general structure of the drive system was studied, in which the reducer not only worked as a wheel-side reducer but also as the single trailing arm. Then, the transmission power losses were modeled by integrating different load-independent and load-independent models of power losses. Next, the experiment of the power losses test for the wheel-side drive system was conducted, which declared the patterns of power losses of electric motor and the whole drive system. Finally, the power losses of wheel-side reducer based on NEDC are studied, which illustrates oil churning and gear sliding power losses are the main types of transmission power losses. At low rotational velocities, gear friction power losses are larger than oil churning power losses. While at high rotational velocities, oil churning power losses are dominant. The transmission efficiency of the reducer based on NEDC varies among the range of 78 ~ 95 %, which depends on the torque and rotational velocity transmitted from the driving motor to EV’s wheel.

UKF Estimation Method of Centroid Slip Angle for Vehicle Stability Control

Pan Wang,Xiaobin Fan,Xinbo Chen,Juean Yi,Shuwen He 제어·로봇·시스템학회 2023 International Journal of Control, Automation, and Vol.21 No.7

Vehicle center of sideslip angle is an essential parameter in vehicle stability control system. In view of the current problems is taken as the research object including low estimation accuracy and poor real-time performance of the current centroid sideslip angle, the four-wheel motor driven electric vehicle. The estimation problem of the sideslip angle is studied in-depth when the vehicle is in a nonlinear state. In addition, an Unscented Kalman Filter (UKF) estimation method is proposed to reduce observation error and improve the practicability of the estimation system. First of all, the research starts with building a 7-degree-of-freedom vehicle model which is based on the Dugoff tire model. Then, after measuring the state parameters, the UKF algorithm is used to estimate the sideslip angle. By comparing with the Extended Kalman Filter (EKF) algorithm, it is confirmed that the estimation method can not only better estimate the center of sideslip angle in real time, but also greater improve the handling stability of the vehicle in the driving state. Besides, the effectiveness of the algorithm is further verified by the real vehicle road test.

Analysis of the Sideband Effect on the Stability of the Voltage-Mode-Controlled Boost Converter

Na Yan,Xinbo Ruan,Yazhou Wang,Xinze Huang 전력전자학회 2019 ICPE(ISPE)논문집 Vol.2019 No.5

Although the small-signal model of the loop gain, which quantitatively include the sideband effect, have been proposed in the resent research, all results are for buck converters. When applying these results for the Voltage-Mode-Controlled(VMC) boost converter, the instability phenomenon, in some cases the converter with the leadingedge modulation is stable while with the trailing-edge modulation it becomes unstable, still couldn’t be explained as the case that using average model. In order to indicate why these results aren’t suitable for boost converter, it is firstly pointed out that the high-frequency characteristic of the duty ratio-to-output transfer function Gvd(s), which the average model fails to describe, could affect the low-frequency performance of the loop gain and the modulator. Then, we give the theoretical prediction of Gvd(s) by using the describe function method, which has excellent agreement with the measured results especially in the high-frequency region. By using the corresponding obtained loop gain, the aforementioned phenomenon would be explained. The work demonstrates significant importance of the research into the sideband effect on the stability for the DC/DC converter and the DC system.

Thermal and mechanical properties of diamond/SiC substrate reinforced by bimodal diamond particles

Pengfei Liu,Xulei Wang,Xinbo He,Xuanhui Qu 한국탄소학회 2022 Carbon Letters Vol.32 No.3

Diamond reinforced silicon carbide matrix composites (diamond/SiC) with high thermal conductivity were prepared by tape casting combined with Si vapor infiltration for thermal management application. The effects of the mixing mode of bimodal diamond particles on the microstructure, thermal and mechanical properties of the composites were analyzed. The results reveal that the thermal conductivity of composites is affected significantly by mixing mode of diamond. In general, when the content of large diamond remains constant, adding a slight amount of small diamond was found to be effective in improving the thermal conductivity of the composite. However, excess small diamonds added will decrease thermal conductivity due to its high interfacial thermal resistance. The maximum thermal conductivity of obtained diamond/SiC is 469 W/(m K) when 38 vol% large diamond and 4 vol% small diamond were added. Such a result can be attributed to the formation of efficient heat transfer channels within the composite and sound interfacial bonding between diamond and SiC phase. Diamond/SiC with high thermal conductivity are expected to be the next generation of electronic packaging substrate.