Cloud computing is becoming a major trend for delivering and accessing infrastructure on demand via the network. Meanwhile, the usage of FPGAs (Field Programmable Gate Arrays) for computation acceleration has made significant inroads into multiple application domains due to their ability to achieve high throughput and predictable latency, while providing programmability, low power consumption and time-to-value. Many types of workloads, e.g. databases, big data analytics, and high performance computing, can be and have been accelerated by FPGAs. As more and more workloads are being deployed in the cloud, it is appropriate to consider how to make FPGAs and their capabilities available in the cloud. However, such integration is nontrivial due to issues related to FPGA resource abstraction and sharing, compatibility with applications and accelerator logics, and security, among others. In this paper, a general framework for integrating FPGAs into the cloud is proposed and a prototype of the framework is implemented based on OpenStack, Linux-KVM and Xilinx FPGAs. The prototype enables isolation between multiple processes in multiple VMs, precise quantitative acceleration resource allocation, and priority-based workload scheduling. Experimental results demonstrate the effectiveness of this prototype, an acceptable overhead, and good scalability when hosting multiple VMs and processes.

No abstract

Global warming has resulted in the melting of glaciers in the southeastern region of Tibet. This study used the InSAR time series obtained from ALOS PALSAR data to investigate the melting glacier over Southeast Tibet during 2007-2010 with the small baseline subset (SBAS) technique. Additionally, GRACE (Gravity Recovery and Climate Experiment) gravity field model issued by the Center for Space Research (CSR) was used to extract the equivalent water height (EWH) with the deduction of glacial isostatic adjustment (GIA). The results revealed that the monitoring results by InSAR were basically consistent with the EWHs from GRACE. The glacier deformation in the study area presents a downward trend overall. From the InSAR measurements, a 900km 2 area within the belt subsided-1.6 cm yr-1 during 2007-2010, and the subsidence exceeded-24 cm yr-1 in some regions. On the other hand, as an auxiliary data source, the monitoring result of GRACE is large space scale and comprehensive, the rate is about-0.01 cm yr-1 from GRACE. With the variations of glacier shape obtained from MODIS (moderate-resolution imaging spectroradiometer) data, the changing rate of surface temperature was about 0.014°C yr-1. The surface temperature change is negatively correlated with the rate of the glacial subsidence with the correlation coefficient of-0.237, which reflects that the melting glacier is influenced by the temperature rising to a certain extent.

No abstract

No abstract