scholarly journals Power and Temperature Prediction for Computer System Power Optimization

2020 ◽  
Author(s):  
Koji Nishi ◽  
Shota Takadai ◽  
Takamichi Kanedai
Keyword(s):  
Computer System ◽  
Power Optimization ◽  
Temperature Prediction ◽  
System Power

scholarly journals Analyzing Mobile Application Software Power Consumption via Model-Driven Engineering

2014 ◽  
pp. 342-367 ◽  
Author(s):  
Chris Thompson ◽  
Jules White ◽  
Douglas C. Schmidt
Keyword(s):  
Power Consumption ◽  
Code Generation ◽  
Power Optimization ◽  
Smartphone Application ◽  
Model Driven Engineering ◽  
Smartphone Applications ◽  
Model Driven ◽  
Battery Power ◽  
Application Developers ◽  
System Power

Smartphones are mobile devices that travel with their owners and provide increasingly powerful services. The software implementing these services must conserve battery power since smartphones may operate for days without being recharged. It is hard, however, to design smartphone software that minimizes power consumption. For example, multiple layers of abstractions and middleware sit between an application and the hardware, which make it hard to predict the power consumption of a potential application design accurately. Application developers must therefore wait until after implementation (when changes are more expensive) to determine the power consumption characteristics of a design. This chapter provides three contributions to the study of applying model-driven engineering to analyze power consumption early in the lifecycle of smartphone applications. First, it presents a model-driven methodology for accurately emulating the power consumption of smartphone application architectures. Second, it describes the System Power Optimization Tool (SPOT), which is a model-driven tool that automates power consumption emulation code generation and simplifies analysis. Third, it empirically demonstrates how SPOT can estimate power consumption to within ~3-4% of actual power consumption for representative smartphone applications.

Power Maximization of a Heavy Duty Diesel Organic Rankine Cycle Waste Heat Recovery System Utilizing Mechanically Coupled and Fully Electrified Turbine Expanders

2016 ◽  
Author(s):  
Bin Xu ◽  
Adamu Yebi ◽  
Simona Onori ◽  
Zoran Filipi ◽  
Xiaobing Liu ◽  
...  
Keyword(s):  
Steady State ◽  
Power Optimization ◽  
Waste Heat ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Working Fluid ◽  
Pump Speed ◽  
Heavy Duty Diesel ◽  
Turbine Speed ◽  
System Power

This paper presents steady state power optimization for an Organic Rankine Cycle (ORC) waste heat recovery (WHR) system in heavy-duty diesel (HDD) applications and examines attainable power levels. Both recirculated and tail pipe exhaust gas streams are utilized as heat sources via a parallel evaporator configuration. A dynamic, physics-based ORC model is utilized to determine optimized net power production. The optimization variables include: working fluid pump speed, mass flow distribution ratio for the parallel evaporators, turbine speed, and the pump speed of condenser cooling fluid. A sensitivity analysis is conducted for all optimization variables. Working fluid pump speed and expansion turbine speed are demonstrated as the most sensitive variables. Sensitivity results indicate increasing system power production as the working fluid mass flow rate increases. A map is developed to identify optimal and safe ORC operating regions for a given engine cycle. Based on the sensitivity analysis working fluid pump speed is selected as the variable of interest in the steady state optimization and results indicate that system power generation could be improved by as much as 25%. Analysis of two quasi steady operational cycles, a multi-mode and a constant speed variable load are conducted. ORC power results indicate that a speed-constrained, mechanically coupled turbine expander operates in its peak efficiency zone to produce maximum power output for the steady-state cycles tested. These steady state power optimization results can be used for future power optimization during engine transients.

Some Recent Results in Quiescent Prominence Spectrometry

1979 ◽  
Vol 44 ◽  
pp. 41-47
Author(s):  
Donald A. Landman
Keyword(s):  
Real Time ◽  
Computer System ◽  
Spectral Response ◽  
Absolute Intensity ◽  
Solar Observatory ◽  
Target Size ◽  
Small Target ◽  
Signal Averaging ◽  
Quiescent Prominence

This paper describes some recent results of our quiescent prominence spectrometry program at the Mees Solar Observatory on Haleakala. The observations were made with the 25 cm coronagraph/coudé spectrograph system using a silicon vidicon detector. This detector consists of 500 contiguous channels covering approximately 6 or 80 Å, depending on the grating used. The instrument is interfaced to the Observatory’s PDP 11/45 computer system, and has the important advantages of wide spectral response, linearity and signal-averaging with real-time display. Its principal drawback is the relatively small target size. For the present work, the aperture was about 3″ × 5″. Absolute intensity calibrations were made by measuring quiet regions near sun center.

Remote real-time computer system for medical research and diagnosis

JAMA ◽  
1966 ◽  
Vol 196 (11) ◽  
pp. 967-972
Author(s):  
J. F. Dickson
Keyword(s):  
Medical Research ◽  
Real Time ◽  
Computer System
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