| 1. |
- Liu, Jia Rong, et al.
(författare)
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Effects of second-order wave force on fatigue damage assessment of a tlp-type floating wind turbine
- 2020
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Ingår i: Proceedings of the International Offshore and Polar Engineering Conference. - 1098-6189 .- 1555-1792. ; 2020-October, s. 415-422
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Konferensbidrag (refereegranskat)abstract
- Resonant and transient responses of a tension leg platform (TLP)-type floating offshore wind turbine can be excited by high-frequency wave forces. This paper investigates the damaging effect of second-order wave forces on structural fatigue in the WindStar TLP system. Dynamic responses in the time domain are analyzed using the program FAST. To explore the mechanisms of different combinations of wind and wave loads inducing damage, five scenarios are considered: wind only, first-order wave only, second-order wave only, joint wind and first-order wave, and joint wind and second-order wave. The results show the dominant effect of second-order waves in tower structural fatigue damage. Additionally, wind and wave coupling becomes stronger under second-order wave loads.
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| 2. |
- Ding, Chen, et al.
(författare)
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An Ultra-Low Latency Multicast Router for Large-Scale Multi-Chip Neuromorphic Processing
- 2021
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Ingår i: 2021 IEEE 3rd international conference on artificial intelligence circuits and systems (AICASs). - : Institute of Electrical and Electronics Engineers (IEEE).
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Konferensbidrag (refereegranskat)abstract
- Neuromorphic simulation is fundamental to the study of information processing mechanism of the human brain and can further inspire application development of event-driven spiking neural networks. However large-scale neuromorphic simulation requires massive parallelism on multi-chip processing and imposes great challenges on dealing with data transmission latency and congestion problems between chips, especially when the number of simulated neurons reaches to billions or even trillions level. In this paper, we propose an ultra-low-latency on-chip router together with a multicast routing algorithm that focuses on reducing global loads and balancing loads between links. Additionally, we build a large-scale neuromorphic simulation platform consisting of 64 FPGA chips and evaluate the proposed design on it. The experiment results suggest that this design benefits from the proposed multicast routing algorithm in global communication loads and simulation capacity. This work has 4.1% similar to 5.2% reduction of global loads comparing to previous works and can achieve a latency as low as 25ns and a maximum data throughput of 6.25Gbps/chip.
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| 3. |
- Jin, Y., et al.
(författare)
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Energy-Aware Workload Allocation for Distributed Deep Neural Networks in Edge-Cloud Continuum
- 2019
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Ingår i: International System on Chip Conference. - : IEEE Computer Society. - 9781728134826 ; , s. 213-217
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Konferensbidrag (refereegranskat)abstract
- This paper presents an energy-aware workload allocation framework for Distributed Deep Neural Networks (DNNs) in the Edge-Cloud continuum. As opposed to conventional approaches where the inference is performed in a standalone device, a computing-communication mode is proposed to distribute computing tasks of different layers of DNNs to different levels of the Edge-Cloud network to achieve the minimum energy cost per inference. The optimal exit layer (EL) can be determined where the intermediate data of the neural networks are transmitted to the higher level in the Edge-Cloud continuum. Case studies are illustrated for AlexNet and VGG-16 considering a set of DNN processors and wireless interfaces. Using the GPU GTX1080 with 22.8 GOPS/W and the WiFi with 10 nJ/bit transmission efficiency, the optimized energy consumption for AlexNet is estimated to be 0.016 J when the inference exits from the edge at the EL2 (Conv1) layer. For VGG-16, the optimal EL is EL1 with the minimum inference cost of 0.0482 J.
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| 4. |
- Zhang, Zhi, et al.
(författare)
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A low delay multiple reader passive RFID system using orthogonal TH-PPM IR-UWB
- 2010
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Ingår i: Proceedings - International Conference on Computer Communications and Networks, ICCCN. - Zurich.
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Konferensbidrag (refereegranskat)abstract
- Current passive RFID systems face the challenges to locate mobile objects in real time in indoor environments, including the realization of low delay as well as effective cooperation among readers and accurate ranging ability in the physical layer. In order to overcome these challenges, this paper presents a low delay multi-reader passive RFID system using ultra high frequency (UHF) radio as the forward link from readers to tags and orthogonal time hopping pulse-position modulation (TH-PPM) impulse ultra-wideband radio (IR-UWB) over the dynamic framed slotted ALOHA algorithm as the backward link from tags to readers. The asymmetric radio links overlap parts of the forward and backward transmission and avoid reader-tag collisions. Readers cooperate via network synchronization by a server and a contention-based update strategy to acknowledge tags. An optimal system configured with 4 readers using 16 orthogonal TH sequences is suggested and operates 3 times faster than the theoretical potential of EPC Class-1 Generation-2 protocol with the listen-before-talk scheme.
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| 5. |
- Zhang, Zhi, et al.
(författare)
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COSMO : CO-simulation with MATLAB and OMNeT++ for indoor wireless networks
- 2010
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Ingår i: 2010 IEEE GLOBAL TELECOMMUNICATIONS CONFERENCE GLOBECOM 2010. - 9781424456383
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Konferensbidrag (refereegranskat)abstract
- Simulations are widely used to design and evaluate new protocols and applications of indoor wireless networks. However, the available network simulation tools face the challenges of providing accurate indoor channel models, three-dimensional (3-D) models, model portability, and effective validation. In order to overcome these challenges, this paper presents a new CO-Simulation framework based on MATLAB and OMNeT++ (COSMO) to rapidly build credible simulations for indoor wireless networks. A hierarchical ad hoc passive RFID network for indoor tag locating is described as a case study, demonstrating the significance and efficiency of COSMO compared with other network simulators. COSMO surpasses other network simulators in terms of workload and validity.
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| 6. |
- Zhang, Zhi, et al.
(författare)
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Two-layered wireless sensor networks for warehouses and supermarkets
- 2009
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The rapid development of wireless sensor network and RFID technologies offers a wide range of novel applications and services. In this paper, we present a two-layered wireless network for warehouses and supermarkets to monitor goods storage and sale, and assist for quality management and market analysis. The hierarchical architecture uses IEEE 802.15.4a impulse ultra-wideband radio (IR-UWB) communication protocol between slave sensor nodes and master sensor nodes, and IEEE 802.11b/g between master sensor nodes and server. The performance of our proposal is evaluated based on the widely used OMNeT++ simulation environment. Simulation results are presented and discussed according to different sampling rates and traffic loads for specific scenarios requirements. © 2009 IEEE.
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| 7. |
- Zhang, Zhi, et al.
(författare)
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Wireless sensor networks for logistics and retail
- 2009
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Ingår i: INSS2009 - 6th International Conference on Networked Sensing Systems. - Pittsburgh, PA. - 9781424463145 ; , s. 98-101
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Internet of Things technologies makes it possible to trace when and where the excellent food or wine is spoiled or loses perfect taste in logistics and retail. This paper describes a system using a two-layered wireless sensor network to monitor the supply chain from manufacturer to consumer, including the network topology, application software on server, and sensor node hardware. It employs GSM/GPRS as the high layer network and semi impulse ultra-wideband radio (IR-UWB) for the low layer communication. We propose GSM Cell-ID location technology for tracking the goods transportation, and time-of-arrival method for local positioning. Finally, the first version of the system implementation and future work are presented. ©2009 IEEE.
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