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In high-performance computing (HPC), end-to-end workflows are typically utilized to gain insights from scientific simulations. An end-to-end workflow consists of scientific simulation and data analysis, and can be executed in-situ, in-transit, and offline. Existing studies on end-to-end workflows have largely focused on the high-performance execution approaches. However, the emerging heterogeneous...
HPC (high-performance computing) applications usually show bursty I/O behaviors. In order to expedite the applications, permanent storage systems are usually provisioned to serve such I/O bursts. Approaching the era of exascale computing, non-volatile RAM is introduced as burst buffers, to absorb the bursty bulk data and relax the I/O provisioning requirement of the permanent storage systems. However,...
Robust and performing navigation systems for Autonomous Underwater Vehicles (AUVs) play a discriminant role towards the success of complex underwater missions. This paper presents a new design and development of a low-cost INS (Inertial Navigation System) using Miro-Electro-Mechanical-System (MEMS) inertial sensor and the pressure sensor (PS). The intensive pre-processing and modeling MEMES sensor's...
Based on monocular camera, an underwater detection and tracking system for amphibious spherical robot is proposed to realize autonomous cruise of underwater pipelines. Firstly, according to the imaging characteristics of underwater image, the image of pipeline is detected by image binarization, edge detection and Hough transform. And then, the Kalman filter was carried out according to the edge information...
Location system is crucial to many intelligent robots, especially for underwater robots. To increase the autonomous ability of amphibious spherical robots in underwater environment, an underwater vision locating system was designed in this paper, and the ToF (time of fly) camera (RGB-D camera) was used and introduced in this system. Through the image capture from the camera in water, two kinds of...
The motion control of underwater spherical robot is a complicated process, which has the characteristics of high inertia and non-linearity. There are many influencing factors for the underwater spherical robot motion such as ambient temperature and water current, so it is difficult to obtain the real-time kinematic model. Therefore, it is hard for traditional PID to achieve stable motion control of...
The conventional long baseline (LBL) positioning system has low update rate of positioning results and poor real-time performance. It reduces its effectiveness and accuracy while locating/navigating for the underwater vehicles(AUVs). We proposes an integrated navigation algorithm based on Extended Kalman Filter, which employs distance and velocity as measurement information. It owns the ability to...
Aiming at exploration tasks in complex amphibious environments, quadruped gaits were designed, implemented and evaluated for our amphibious spherical robot to enhance its adaptabilities to various terrains. A simplified locomotion model of the robot was established to analyze the walking process. Then three types of walk gait were implemented on the robotic platform using FPGA, which provided different...
With the developing of science and technology, microwave remote sensing has been widely applied to many areas of production and life. Synthetic Aperture Radar (SAR) which can provide high-resolution images, has become an important means of objective observation and surveillance in military and civilian fields. This paper based on the analysis of SAR radar echo data characteristics, using the peak...
DRAM memory performs periodic refreshes to prevent data loss due to charge leakage, while memory refreshes cause performance degradation and energy consumption, referred to as refresh overheads. In this paper, we propose Refresh-Oriented Prefetching (ROP) to alleviate memory refresh overheads. Before a refresh starts, ROP prefetches cache lines from the tobe-refreshed rank into an added SRAM buffer...
As a critical important function for autonomous mobile robots, visual tracking is a challenge work in the field of computer vision, for the reason that factors like illumination variance, partial occlusions and target appearance changes shall be carefully considered. Focus on applications of our amphibious spherical robots, an adaptive visual tracking algorithm was proposed on the basis of compressive...
Information exchanges and cooperative movements of multiple robots have become a hot topic in robotics. To increase the adaptability of robots in amphibious scenarios, an improved amphibious spherical robot was designed in this paper. However, the ability of single robot was limited. To further increase the sensing range and work efficiency of own amphibious spherical robots, a Leader-follower method,...
Checkpoint and restart mechanisms have been widely used in large scientific simulation applications to make forward progress in case of failures. However, none of the prior works have considered the interaction of power-constraint with temperature, reliability, performance, and checkpointing interval. It is not clear how power-capping may affect optimal checkpointing interval. What are the involved...
Aiming at prolonging the lifetime of Wireless Sensor Networks(WSNs), Distributed Dynamic Cluster Algorithm (DDCA) was proposed. DDCA clusters all the nodes which have detected the event together, then the fused data is forwarded to Base Station(BS) through the backbone nodes. Clustering process is carried out when events occur in the WSNs, for each event, only one fused data package is forwarded to...
Affinity is common among Virtual Machines (VMs) in cloud environments. If VMs collaborating on a job are split in geographically distributed clouds, the low bandwidth and high latency inter-cloud communication via a wide area network (WAN) will dramatically degrade the system performance. A potential solution is migrating all of the VMs collaborating on a job in parallel, so as to avoid wide area...
In this paper, a novel composite right/left handed transmission line (TL) structure is proposed. The CRLH TL has high-pass property at lower frequencies and low-pass property at higher frequencies, thus constructs a bandpass filter. Lumped or quasi-lumped microwave components are introduced to satisfy the necessity of the filter. Simulation using ADS and HFSS demonstrated the viability of the approach.
The frequency characteristics of the microstrip line with DGS are simulated by means of 3-D field analysis, and its equivalent circuit and equivalent parameters extraction are analyzed. Then the influences of C shape and the material permittivity on frequency characteristic are discussed using the simulation with Taguchi method.
Error concealment at the decoder side is an economical approach to ensuring an acceptable and stable video quality in case of packet erasure or loss, and thus attracts lots of interest. Current techniques mainly employ the spatial or temporal correlation to predict the motion vectors of the missing blocks, and interpolation, extrapolation or boundary matching schemes are usually effective. However,...
CUDA performs general purpose parallel computing using GPGPU, which has been applied to various computing fields. However, the multi-address-space architecture in CUDA makes memory management complicated. NVIDIA introduced UVA, Unified Virtual Addressing, into CUDA Toolkit 4.0 to address this issue. However, UVA has platform limitations and even performance loss under certain circumstances. We propose...
De-component is a critical process to either device reuse or rework. This paper investigated the temperature impact on the BGA during the de-component process. The non-uniform temperature was created by special designs of de-component fixtures. The temperature profiles of solder joints were monitored by thermocouples. Plastic ball grid arrays (PBGA) of three package sizes (23×23 mm, 27×27 mm and 35×35...
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