scholarly journals Dynamic Temperature Management of Near-Sensor Processing for Energy-Efficient High-Fidelity Imaging

Sensors ◽  
2021 ◽  
Vol 21 (3) ◽  
pp. 926
Author(s):  
Venkatesh Kodukula ◽  
Saad Katrawala ◽  
Britton Jones ◽  
Carole-Jean Wu ◽  
Robert LiKamWa

Vision processing on traditional architectures is inefficient due to energy-expensive off-chip data movement. Many researchers advocate pushing processing close to the sensor to substantially reduce data movement. However, continuous near-sensor processing raises sensor temperature, impairing imaging/vision fidelity. We characterize the thermal implications of using 3D stacked image sensors with near-sensor vision processing units. Our characterization reveals that near-sensor processing reduces system power but degrades image quality. For reasonable image fidelity, the sensor temperature needs to stay below a threshold, situationally determined by application needs. Fortunately, our characterization also identifies opportunities—unique to the needs of near-sensor processing—to regulate temperature based on dynamic visual task requirements and rapidly increase capture quality on demand. Based on our characterization, we propose and investigate two thermal management strategies—stop-capture-go and seasonal migration—for imaging-aware thermal management. For our evaluated tasks, our policies save up to 53% of system power with negligible performance impact and sustained image fidelity.

2021 ◽  
Vol 129 (8) ◽  
pp. 085301
Author(s):  
Robert H. Montgomery ◽  
Yuewei Zhang ◽  
Chao Yuan ◽  
Samuel Kim ◽  
Jingjing Shi ◽  
...  

2014 ◽  
Vol 162 (1) ◽  
pp. A137-A148 ◽  
Author(s):  
Todd Bandhauer ◽  
Srinivas Garimella ◽  
Thomas F. Fuller

Author(s):  
Christopher H. Wendel ◽  
Pejman Kazempoor ◽  
Robert J. Braun

Electrical energy storage (EES) is an important component of the future electric grid. Given that no other widely available technology meets all the EES requirements, reversible (or regenerative) solid oxide cells (ReSOCs) working in both fuel cell (power producing) and electrolysis (fuel producing) modes are envisioned as a technology capable of providing highly efficient and cost-effective EES. However, there are still many challenges from cell materials development to system level operation of ReSOCs that should be addressed before widespread application. One particular challenge of this novel system is establishing effective thermal management strategies to maintain the high conversion efficiency of the ReSOC. The system presented in this paper employs a thermal management strategy of promoting exothermic methanation in the ReSOC stack to offset the endothermic electrolysis reactions during charging mode (fuel producing) while also enhancing the energy density of the stored gases. Modeling and parametric analysis of an energy storage concept is performed using a thermodynamic system model coupled with a physically based ReSOC stack model. Results indicate that roundtrip efficiencies greater than 70% can be achieved at intermediate stack temperature (∼680°C) and pressure (∼20 bar). The optimal operating conditions result from a tradeoff between high stack efficiency and high parasitic balance of plant power.


2014 ◽  
Vol 104 (5) ◽  
pp. 601-609 ◽  
Author(s):  
X.-W. Fu ◽  
C. Li ◽  
H.-Q. Feng ◽  
Z.-F. Liu ◽  
J.W. Chapman ◽  
...  

AbstractThe rice leaf roller,Cnaphalocrocis medinalis(Guenée), is a serious insect pest of rice with a strong migratory ability. Previous studies on the migration ofC. medinaliswere mostly carried out in tropical or subtropical regions, however, and what the pattern of seasonal movements this species exhibits in temperate regions (i.e. Northern China, where they cannot overwinter) remains unknown. Here we present data from an 11-year study of this species made by searchlight trapping on Beihuang Island (BH, 38°24′N; 120°55′E) in the centre of the Bohai Strait, which provides direct evidence thatC. medinalisregularly migrates across this sea into northeastern agricultural region of China, and to take advantage of the abundant food resources there during the summer season. There was considerable seasonal variation in number ofC. medinalistrapped on BH, and the migration period during 2003–2013 ranged from 72 to 122 days. Some females trapped in June and July showed a relatively higher proportion of mated and a degree of ovarian development suggesting that the migration of this species is not completely bound by the ‘oogenesis-flight syndrome’. These findings revealed a new route forC. medinalismovements to and from Northeastern China, which will help us develop more effective management strategies against this pest.


Author(s):  
Yasmin Khakpour ◽  
Weilun Warren Chen ◽  
Parikshith Channegowda ◽  
Matthew R. Pearson ◽  
Yongduk Lee ◽  
...  

Abstract The thermal management of the PCB based power electronics is a key element to ensure safe operating conditions and to meet lifetime, reliability and safety requirements. This is challenging for applications above 1 kW because the substrate material used in a PCB such as FR-4 has very low heat conducting properties. Hence, there is a limit on how much loss can be dissipated from the board and for that reason this approach has only been adopted in the industry for very low power applications. With the proposed multilevel topology, WBG devices, and innovative thermal management strategies it is possible to expand the PCB based power electronics approach to power ratings between 1kW and 10 kW. For instance, an improvement in the thermal resistance of the PCB can be obtained by soldering a discrete WBG device with a TO-263 package directly on a PCB with about one inch square copper area around the device which will act as a heat spreader. Then, a further substantial reduction in the thermal resistance of a PCB is possible by the application of electrical vias. In principle each via is a copper sleeve through the board or through a part of the board. Where, instead of using its electrical function, a via can also be used as a thermal conductor. In this work, the thermal analysis of the PCB and the effect of number of vias as well as the effect of filling the vias with a thermally conductive material has been studied. The design has been optimized for the number of vias and the modeling results have been verified with experimental tests.


Author(s):  
Tim Wegner ◽  
Martin Gag ◽  
Dirk Timmermann

With the progress of deep submicron technology, power consumption and temperature related issues have become dominant factors for chip design. Therefore, very large-scale integrated systems like Systems-on-Chip (SoCs) are exposed to an increasing thermal stress. On the one hand, this necessitates effective mechanisms for thermal management. On the other hand, application of thermal management is accompanied by disturbance of system integrity and degradation of system performance. In this paper the authors propose to precompute and proactively manage on-chip temperature of systems based on Networks-on-Chip (NoCs). Thereby, traditional reactive approaches, utilizing the NoC infrastructure to perform thermal management, can be replaced. This results not only in shorter response times for application of management measures and a reduction of temperature and thermal imbalances, but also in less impairment of system integrity and performance. The systematic analysis of simulations conducted for NoC sizes ranging from 2x2 to 4x4 proves that under certain conditions the proactive approach is able to mitigate the negative impact of thermal management on system performance while still improving the on-chip temperature profile.


2000 ◽  
Author(s):  
Anthony Eggert ◽  
P. Badrinarayanan ◽  
David Friedman ◽  
Joshua Cunningham

Abstract Proton exchange membrane (PEM) fuel cell systems using steam-reformed methanol are currently under consideration for first generation commercial fuel cell vehicles. Proper water and heat management of such a system is critical in achieving high overall efficiency and maintaining water self-sufficiency. The first part of the paper briefly describes the key aspects of the water and thermal management (WTM) model developed as part of the Fuel Cell Vehicle Modeling Program (FCVMP) at the University of California – Davis. The main purpose of this model was to determine the water self-sufficiency and temperature management requirements of the indirect methanol fuel cell system and to evaluate the associated parasitic losses. This model has imbedded in it the main components of the fuel cell system, such as the fuel cell stack, air compressor, and fuel processor as seen by the WTM system. The second half of the paper discusses the results obtained from the model and their implications. We find that the cooling and humidification of the anode and cathode inlet streams can be accomplished with water injection and therefore, a separate heat exchanger is not needed for additional cooling. Additionally we find that the instantaneous and cumulative excess water is determined by factors such as air supply characteristics, condenser efficiency, ambient air humidity, and stack attributes. We find that these factors can affect the ability of the vehicle to achieve true water self-sufficiency.


Sign in / Sign up

Export Citation Format

Share Document