Multi-dimensional optimization for approximate near-threshold computing

The demise of Dennard’s scaling has created both power and utilization wall challenges for computer systems.As transistors operating in the near-threshold region are able to obtain flexible trade-offs between power and performance,it is regarded as an alternative solution to the scaling challenge.A reduction in supply voltage will nevertheless generate significant reliability challenges,while maintaining an error-free system that generates high costs in both performance and energy consumption.The main purpose of research on computer architecture has therefore shifted from performance improvement to complex multi-objective optimization.In this paper,we propose a three-dimensional optimization approach which can effectively identify the best system configuration to establish a balance among performance,energy,and reliability.We use a dynamic programming algorithm to determine the proper voltage and approximate level based on three predictors:system performance,energy consumption,and output quality.We propose an output quality predictor which uses a hardware/software co-design fault injection platform to evaluate the impact of the error on output quality under near-threshold computing(NTC).Evaluation results demonstrate that our approach can lead to a 28% improvement in output quality with a 10% drop in overall energy efficiency;this translates to an approximately 20% average improvement in accuracy,power,and performance.

Enhanced critical-sized bone defect repair efficiency by combining deproteinized antler cancellous bone and autologous BMSCs

Previously we have demonstrated that calcinated antler cancellous bone（CACB） has great potential for bone defect repair,due to its highly similar composition and architecture to natural extracellular bone matrix.This study is aiming at seeking for an optimal strategy of combined application of CACB and bone marrow mesenchymal stem cells（BMSCs） in bone defect repair.In vitro study demonstrated that CACB promoted the adhesion,spreading and viability of BMSCs.Increased extracellular matrix production and expression of osteogenic markers in BMSCs were observed when seeded on CACB scaffolds.The cells ceased to proliferation in the dual effect of CACB and osteogenic induction at the early stage of incubation.Hence synergistic effect of CACB combined with autologous undifferentiated BMSCs in rabbit mandible critical-sized defect repair was further evaluated.Histological analysis results showed that loading the CACB with autologous BMSCs resulted in enhanced new bone formation and angiogenesis when compared with implanted CACB alone.These findings indicate that the combination of CACB and autologous BMSCs should become potential routes to improve bone repair efficiency