Utilization-Aware Data Variable Allocation on NVM- Based SPM in Real-Time Embedded Systems

With the development of the nonvolatile memory(NVM),using NVM in the design of the cache and scratchpad memory(SPM)has been increased.This paper presents a data variable allocation(DVA)algorithm based on the genetic algorithm for NVM-based SPM to prolong the lifetime.The lifetime can be formulated indirectly as the write counts on each SPM address.Since the differences between global variables and stack variables,our optimization model has three constraints.The constraints of the central processing unit(CPU)utilization and size are used for all variables,while no-overlay constraint is only used for stack variables.To satisfy the constraints of the optimization model,we use the greedy strategy to generate the initial population which can determine whether data variables are allocated to SPM and distribute them evenly on SPM addresses.Finally,we use the Mälardalen worst case executive time(WCET)benchmark to evaluate our algorithm.The experimental results show that the DVA algorithm can not only obtain close-to-optimal solutions,but also prolong the lifetime by 9.17% on average compared with SRAM-based SPM.

Power-Aware Data Management Based on Hybrid RAM-NVM Memory for Smart Bracelet

Wearable devices become popular because they can help people observe health condition.The battery life is the critical problem for wearable devices. The non-volatile memory(NVM) attracts attention in recent years because of its fast reading and writing speed, high density, persistence, and especially low idle power. With its low idle power consumption,NVM can be applied in wearable devices to prolong the battery lifetime such as smart bracelet. However, NVM has higher write power consumption than dynamic random access memory(DRAM). In this paper, we assume to use hybrid random access memory(RAM)and NVM architecture for the smart bracelet system.This paper presents a data management algorithm named bracelet power-aware data management(BPADM) based on the architecture. The BPADM can estimate the power consumption according to the memory access, such as sampling rate of data, and then determine the data should be stored in NVM or DRAM in order to satisfy low power. The experimental results show BPADM can reduce power consumption effectively for bracelet in normal and sleeping modes.

Outcomes after natural orifice extraction vs conventional specimen extraction surgery for colorectal cancer: A propensity scorematched analysis

BACKGROUND Natural orifice specimen extraction(NOSE)via the anus or vagina replaces conventional transabdominal specimen retrieval via the transabdominal route through a limited mid-line laparotomy or Pfannenstiel incision.Reducing the number of laparoscopic ports further decreases operative abdominal wall trauma.These techniques reduce the surgical wound size as well as the risk of incisionrelated morbidity.AIM To compare short-term outcomes following 3-port NOSE surgery with a matched cohort of conventional non-NOSE colorectal cancer surgery.METHODS Patients who underwent elective 3-port laparoscopic colorectal NOSE surgery between February to October 2021 were identified.Selection criteria for NOSE surgery was adapted from the 2019 International Consensus on Natural Orifice Specimen Extraction Surgery for colorectal cancer.Patients with clinical T4 or N2 tumors on staging computed tomography were also excluded.The propensity score-matched cohort was identified amongst patients who underwent conventional laparoscopic colorectal surgery from January 2019 to December 2020.Matching was performed in the ratio of 1:4 based on age,gender,type of resection,and p-tumor node metastasis staging.RESULTS Over the eight-month study duration,14 consecutive cases(nine female,five male)of elective 3-port laparoscopic surgery with NOSE were performed for colorectal cancer.Median age and body mass index were 70(range 43-82)years and 24.1(range 20.0-31.7)kg/m2 respectively.Six patients underwent transanal NOSE and eight had transvaginal NOSE.Median operative time,intraoperative blood loss and postoperative length of stay were 208(range 165-365)min,30(range 10-150)mL and 3(range 2-6)d respectively.Two(14%)suffered minor postoperative compilations not attributable to the NOSE procedure.Median follow-up duration was 12(range 8-15)mo.No instances of mortality,local or distant disease recurrence were recorded in this cohort.Compared to the conventional surgery cohort of 56 patients,the 3-port NOSE cohort had significantly quicker mean return of bowel function(2.6 vs 1.2 d,P<0.001),reduced postoperative pain and patientcontrolled analgesia use,and decreased length of hospital stay(6.4 vs 3.4 d,P<0.001).There were no statistical differences in surgical duration and perioperative complication rates between the NOSE and non-NOSE cohorts.CONCLUSION 3-port laparoscopic colorectal surgery with NOSE is a feasible technique,augmenting the minimally invasive nature of surgery and producing good outcomes.Appropriate patient selection and expertise in conventional laparoscopy are required.

An image analysis method for quantification of hepatic perfusion based on contrast-enhanced ultrasound imaging

Information about hepatic perfusion is used in clinical liver disease diagnosis. An image analy-sis system can help physicians make efficient and accurate diagnosis. The objective of this study is to propose an image analysis method for the quantification of the hepatic perfusion based on contrast-enhanced ultrasound imaging (CEUI). The proposed method contains frame selection, image registration, digital subtraction and grey-scale calculation. Then, by processing an image sequence, a time-intensity curve (TIC) for hepatic perfusion is derived. The kernel of this image analysis technology is digital subtrac-tion and its accuracy is improved by frame selec-tion and image registration. The advantage of this method is that it can obtain the perfusion information of the whole liver which is rarely ob-tained by traditional image analysis technology;therefore, it is a supplement of the traditional image analysis method. This method is applied on the quantification of a rabbit’s hepatic perfu-sion and the result shows the efficiency of it.

Evaluation of heavy roller compaction on a large-thickness layer of subgrade with full-scale field experiments

Subgrade construction is frequently interrupted due to precipitation,soil shortage,and environmental protection.Therefore,increasing the thickness layer is required to reduce construction costs and to allow highways to be placed into service earlier.This paper presents a series of full-scale field experiments evaluating the compaction quality of gravel subgrade with large-thickness layers of 65 cm and 80 cm using heavy vibratory rollers.An improved sand cone method was first proposed and calibrated to investigate the distribution of soil compaction degree across the full subgrade depth.Results showed that dynamic soil stresses caused by the heavy vibratory rollers were 2.4–5.9 times larger than those of traditional rollers,especially at deeper depths,which were large enough to densify the soils to the full depth.A unified empirical formula was proposed to determine the vertical distribution of dynamic soil stresses caused by roller excitation.It was demonstrated that soils were effectively compacted in a uniform fashion with respect to the full depth to 96.0%–97.2%and 94.1%–95.4%for the large-thickness layers of 65 cm and 80 cm within 6 or 7 passes,respectively.Empirically,linear formulae were finally established between soil compaction degree and the subgrade reaction modulus,dynamic modulus of deformation,dynamic deflection,and relative difference of settlement to conveniently evaluate the compaction qualities.It is demonstrated that increasing the thickness layer by means of heavy rollers can significantly reduce the cost and time burdens involved in construction while ensuring overall subgrade quality.