From Open CNC systems to Cyber-Physical machine tools: a case study

The aim of next-generation Computer Numerical Control (CNC) is shifting from an open architecture, which has better flexibility, adaptability, versatility and expansibility, to a cyber-physical model, which offers real-time monitoring and control of the machining processes. This paper introduces a real case study to demonstrate such tendency from Open CNC systems to Cyber-Physical Machine Tools (CPMT) based on a low-power embedded platform. Firstly, a new open CNC architecture is presented, which is able to achieve high-precision, high-efficiency, and low-power consumption. Secondly, the open CNC architecture is extended to a CPMT by using Wireless Sensor Networks (WSN), where WSN is utilized to enable monitor and control the machining processes, and the integrated development platform is termed as CPMT. Finally, a case of health monitoring system for CPMT is designed and its system testing is carried out

Data cleansing for energy-saving: a case of Cyber-Physical Machine Tools health monitoring system

Cyber-Physical Production Systems (CPPS) often use wireless sensor networks (WSNs) for monitoring purposes. However, data from WSNs may be inaccurate and unreliable due to power exhaustion, noise and other issues. In order to achieve a reliable and accurate data acquisition while ensuring low energy consumption and long lifetime of WSNs, data cleansing algorithms for energy-saving are proposed in this research. The cleansing algorithms are computationally lightweight in local sensors and energy-efficient due to low energy consumption in communications. Dynamic voltage scaling and dynamic power management are adopted for reducing energy consumption, without compromising the performance at system level. A low-power protocol for sink node communication is proposed at network level. A health monitoring system for a Cyber-Physical Machine Tool (a typical example of CPPS) is designed. Experiment results show that the proposed energy-saving data cleansing algorithm yields high-performance and effective monitoring

Urbanization minimizes the effects of plant traits on soil provisioned ecosystem services across climatic regions

An increasingly urbanized world is one of the most prominent examples of global environmental change. Across the globe, urban parks are designed and managed in a similar way, resulting in visually pleasing expansions of lawn interspersed with individually planted trees of varying appearances and functional traits. These large urban greenspaces have the capacity to provide various ecosystem services, including those associated with soil physicochemical properties. Our aim was to explore whether soil properties in urban parks diverge underneath vegetation producing labile or recalcitrant litter, and whether the impact is affected by climatic zone (from a boreal to temperate to tropical city). We also compared these properties to those in (semi)natural forests outside the cities to assess the influence of urbanization on plant-trait effects. We showed that vegetation type affected percentage soil organic matter (OM), total carbon (C) and total nitrogen (N), but inconsistently across climatic zones. Plant-trait effects were particularly weak in old parks in the boreal and temperate zones, whereas in young parks in these zones, soils underneath the two tree types accumulated significantly more OM, C and N compared to lawns. Within climatic zones, anthropogenic drivers dominated natural ones, with consistently lower values of organic-matter-related soil properties under trees producing labile or recalcitrant litter in parks compared to forests. The dominating effect of urbanization is also reflected in its ability to homogenize soil properties in parks across the three cities, especially in lawn soils and soils under trees irrespective of functional trait. Our study demonstrates that soil functions that relate to carbon and nitrogen dynamics-even in old urban greenspaces where plant-soil interactions have a long history-clearly diverged from those in natural ecosystems, implying a long-lasting influence of anthropogenic drivers on soil ecosystem services.Peer reviewe

Magnetic resonance venous volume measurements in peripheral artery disease (from ELIMIT)

The relation between the arterial and venous systems in patients with impaired lower extremity blood flow remains poorly described. The objective of this secondary analysis of the Effectiveness of Intensive Lipid Modification Medication in Preventing the Progression on Peripheral Artery Disease Trial was to determine the association between femoral vein (FV) volumes and measurements of peripheral artery disease. FV wall, lumen, and total volumes were quantified with fast spin-echo proton density-weighted magnetic resonance imaging scans in 79 patients with peripheral artery disease over 2 years. Reproducibility was excellent for FV total vessel (intraclass correlation coefficient 0.924, confidence interval 0.910 to 0.935) and lumen volumes (intraclass correlation coefficient 0.893, confidence interval 0.873 to 0.910). Baseline superficial femoral artery volumes were directly associated with FV wall (r = 0.46, p \u3c0.0001), lumen (r = 0.42, p = 0.0001), and total volumes (r = 0.46, p \u3c0.0001). The 2-year change in maximum walking time was inversely associated with the 24-month change in FV total volume (r = -0.45, p = 0.03). In conclusion, FV volumes can be measured reliably with fast spin-echo proton density-weighted magnetic resonance imaging, and baseline superficial femoral artery plaque burden is positively associated with FV volumes, whereas the 2-year change in FV volumes and leg function show an inverse relation

The effect of lipid modification on peripheral artery disease after endovascular intervention trial (ELIMIT)

Methods: A total of 102 patients were randomized to either mono-therapy with simvastatin (40 mg daily) or triple-therapy with simvastatin (40 mg daily), extended-release niacin (1500 mg daily), and ezetimibe (10 mg daily). MRI was performed at baseline and 6, 12, and 24 months. SFA wall, lumen, and total vessel volumes were quantified. MRI-derived SFA parameters and lipids were analyzed with multilevel models and nonparametric tests, respectively.Results: Baseline characteristics did not differ between mono and triple-therapy groups, except for ethnicity (p = 0.02). SFA wall, lumen, and total vessel volumes increased non-significantly for both groups between baseline and 24-months. Non-high-density lipoprotein cholesterol was significantly reduced at 12 months with triple-therapy compared with mono-therapy (p = 0.01).Conclusion: No significant differences were observed between mono-therapy using simvastatin and triple-therapy with simvastatin, extended-release niacin, and ezetimibe for 24-month changes in SFA wall, lumen, and total vessel volumes.Clinical trial registration information: NCT00687076; Link: http://clinicaltrials.gov/ct2/show/NCT00687076

Comparison of longitudinal skeletal thigh muscle findings with magnetic resonance imaging in patients with Peripheral Artery Disease with-versus-without diabetes mellitus

The aim of this secondary analysis of ELIMIT (The Effect of Lipid Modification on Peripheral Artery Disease after Endovascular Intervention Trial) was to determine longitudinal changes over 24 months in skeletal thigh muscle volumes and individual muscle compartments in patients with peripheral artery disease (PAD) with and without diabetes. A total of 48 patients with available magnetic resonance imaging of the distal superficial femoral artery at baseline and 2 years were included in this analysis. Muscle volumes and superficial femoral artery wall, lumen, and total vessel volumes were quantified. Intrareader reproducibility of muscle tracings was assessed with the intraclass correlation coefficient using a 2-way model. Baseline characteristics were similar between patients with PAD with and without diabetes, except for smoking history (p = 0.049), cholesterol levels (p \u3c0.050), and calf walking pain (p = 0.049). Interobserver reproducibility of the muscle volume tracings was excellent for all muscle groups (all intraclass correlation coefficients \u3e0.86, confidence interval 0.69 to 0.94). Total muscle and total leg volumes increased significantly between baseline and 24 months among patients with PAD without diabetes (31 ± 6.4 cm3 vs 32 ± 7.0 cm3, p \u3c0.001; 18 ± 4.4 cm3 vs 19 ± 4.8 cm3, p = 0.045), whereas there was no change in patients with PAD and diabetes. Total muscle volume was inversely associated with age and body mass index in patients with PAD both with and without diabetes (p \u3c0.05). In conclusion, magnetic resonance imaging-quantified thigh muscle volumes are highly reproducible and may be of interest in assessing PAD patients with and without diabetes