Optimization of Discrete-parameter Multiprocessor Systems using a Novel Ergodic Interpolation Technique

Modern multi-core systems have a large number of design parameters, most of which are discrete-valued, and this number is likely to keep increasing as chip complexity rises. Further, the accurate evaluation of a potential design choice is computationally expensive because it requires detailed cycle-accurate system simulation. If the discrete parameter space can be embedded into a larger continuous parameter space, then continuous space techniques can, in principle, be applied to the system optimization problem. Such continuous space techniques often scale well with the number of parameters. We propose a novel technique for embedding the discrete parameter space into an extended continuous space so that continuous space techniques can be applied to the embedded problem using cycle accurate simulation for evaluating the objective function. This embedding is implemented using simulation-based ergodic interpolation, which, unlike spatial interpolation, produces the interpolated value within a single simulation run irrespective of the number of parameters. We have implemented this interpolation scheme in a cycle-based system simulator. In a characterization study, we observe that the interpolated performance curves are continuous, piece-wise smooth, and have low statistical error. We use the ergodic interpolation-based approach to solve a large multi-core design optimization problem with 31 design parameters. Our results indicate that continuous space optimization using ergodic interpolation-based embedding can be a viable approach for large multi-core design optimization problems.Comment: A short version of this paper will be published in the proceedings of IEEE MASCOTS 2015 conferenc

Fatigue behavior of flexhoses and bellows due to flow-induced vibrations

The analysis and results developed in a fresh approach to calculate flow induced vibration response of a flexible flow passage are summarized. The vibration results are further examined in the frequency domain to obtain dominant frequency information. A cumulative damage analysis due to cyclic strains is performed to obtain the number of cycles to failure for a metallic bellows of particular specifications under a variety of operational conditions. Sample plots of time and frequency domain responses are included. The complex listing of a computer program is provided. The program successively executes each of the analyses needed to calculate the vibration response, the frequency response, the cyclic strains and the number of cycles to failure. The program prompts the user for necessary input information. Sample data from the program is provided. The fatigue life results obtained by the computer model lie within an acceptable range of previously measured available data

Management of communited patellar fracture with combined Tension Band Wiring Technique and Encirclage

Background: The objective of the study was to evaluate functional results of combined encirclage wiring and tension band fixation in comminuted patellar fractures.Methods: This is a prospective study of 15 patients treated with this method. All fractures described herein were classified as 45-C3 (based on Orthopaedic Trauma Association classification) and were fixed with encirclage wire and tension band wire proximally looped through the quadriceps tendon and distally through the patellar ligament in a figure-of-eight configuration. Knee function was evaluated using the Rasmussen scores at final follow-up.Results: 13 patients gained up to 90 degrees of active flexion at the end of the first week. 4 patients had 10–15 degrees of extensor lag at the end of the first week which improved after vigorous physiotherapy and none of them had any residual extensor lag at the subsequent follow-up. Two patients developed superficial infection. All fractures united at the end of 12 weeks. One patient underwent a second surgery; due to implant related complications. Malunion or non-union was not noted in any of the cases. The average Rasmussen scores was 27.9 out of 30 (range, 27–29).Conclusions: The tension band technique combined with cable encirclage for treatment of communited fractures of patella is a simple and technically less demanding operative technique producing a rigid fixation, stable osteosynthesis and minimal injury to the tendon. It can be done with easily available implants.

Real Time Net Zero Energy Building Energy Manager with Heterogeneous Wireless Ad hoc Network Adaptable To IoT Architectures

Significant energy consumption by buildings from utility grid has made researchers revisit existing Building Energy Management Systems (BEMS). Most of the developing countries have taken a green initiative of Net Zero Energy Buildings (NZEB) to reduce carbon foot print and fast depletion of conventional energy sources. Though the integration of solar and wind based systems to grid is successful in recent years, residential building energy management systems with renewable energy sources is still an evolving research area. Monitoring, control and actuation systems should be tightly coupled with the help of any to any device communication namely Internet of Things (IoT) to realize an efficient NZEB. In this paper a real time NZEB is proposed and developed with bi-directional wireless sensor and actuation system. Proposed NZEB central server collects and maintains a database of on site solar generation, battery state of charge and load power consumption data of a building with help of IEEE 802.15.4 and IEEE 802.11 wireless networks. Proposed system was deployed as a test bed with sensing, control, actuation and server modules and connecting them with a bi-directional wireless network architecture similar to IoT. Data observed at experimental test bed confirm that developed system can estimate on site solar power generation, state of charge on battery bank and load power consumption with negligible error. A simulation study with experimental data collected at NZEB test bed shows that NZEB can optimally schedule loads between local generation and utility grid thereby minimizing peak demand on the grid