BeSS: An R Package for Best Subset Selection in Linear, Logistic and Cox Proportional Hazards Models

We introduce a new R package, BeSS, for solving the best subset selection problem in linear, logistic and Cox's proportional hazard (CoxPH) models. It utilizes a highly efficient active set algorithm based on primal and dual variables, and supports sequential and golden search strategies for best subset selection. We provide a C++ implementation of the algorithm using an Rcpp interface. We demonstrate through numerical experiments based on enormous simulation and real datasets that the new BeSS package has competitive performance compared to other R packages for best subset selection purposes

Optical flow tracking method for vibration identification of out-of-plane vision

Vibration measurement based on computer vision has been extensively studied and considered as a wide-range, non-contact measurement method. In this paper, the principle of vibration measurement using out-of-plane vision has been investigated under conventional imaging condition. A measurement model for out-of-plane vision has also been demonstrated. Combined the out-of-plane vision measurement model with the optical flow motion estimation principle, a novel model of optical flow tracking method for vibration detection based on out-of-plane vision has been proposed. It enables the identification of vibration parameters without image feature extraction. Visual vibration detection experiment has been conducted with a cantilever beam and a motor cover. Experimental results have been rigorously compared with finite element simulation to verify the efficacy of the proposed method. It shows that this method can effectively identify vibration parameters of the structure without image feature extraction

Acetaldehyde dehydrogenase 2 (ALDH2) deficiency exacerbates pressure overload-induced cardiac dysfunction by inhibiting Beclin-1 dependent autophagy pathway

AbstractMitochondrial aldehyde dehydrogenase 2 (ALDH2) was demonstrated to play cardioprotective roles in cardiovascular diseases. Nonetheless, little is known about the roles and mechanisms of ALDH2 in pressure overload-induced cardiac damages. In this study, we revealed that ALDH2 deficiency overtly exacerbated transverse aortic constriction (TAC)-induced cardiac dysfunction. Cardiomyocyte enlargement was observed in both WT and ALDH2−/− mice in HE-stained myocardial tissue samples at 8weeks post TAC surgery. Mitochondrial morphology and structure were also significantly damaged post TAC surgery and the changes were aggravated in ALDH2−/− TAC hearts. ALDH2 deficiency also depressed myocardial autophagy in hearts at 8weeks post TAC surgery with a potential mechanism of repressing the expression of Beclin-1 and promoting the interaction between Bcl-2 and Beclin-1. These data indicate that ALDH2 deficiency exacerbates the pressure overload induced cardiac dysfunction partly by inhibiting Beclin-1 dependent autophagy pathway.This article is part of a Special Issue entitled: Autophagy and protein quality control in cardiometabolic diseases

An empirical study of collaborative capacity evaluation and scheduling optimization for a CPD project.

In a collaborative product design project, reasonable resource allocation can shorten the development cycle and reduce cost. Team capacity evaluation and a task-team scheduling model are presented. A collaborative team capacity model is constructed, and a 2-tuple linguistic method is used to evaluate the capacity of collaborative teams. Next, the matching degree between design task and collaborative team is defined. A collaborative product design scheduling model considering task-team matching is developed. Combined with the simulated annealing operator, based on the single-coding strategy, self-adaptive multi-point cross and mutation, an improved genetic algorithm is proposed to solve the model. Finally, a case study is presented to validate the method

The Structure and Properties of Polyacrylonitrile Nascent Composite Fibers with Grafted Multi Walled Carbon Nanotubes Prepared by Wet Spinning Method

Polyacrylonitrile (PAN) grafted amino-functionalized multi walled carbon nanotubes (amino-MWCNTs) were synthesized by in situ polymerization under aqueous solvent. The grafted MWCNT/PAN nascent composite fibers were prepared by the wet spinning method. Fourier transform infrared spectroscopy and Raman spectroscopy indicated that the amino-MWCNTs and PAN macromolecular chains had interfacial interactions and formed chemical bonds. The grafting content of the PAN polymer on the amino-MWCNTs was up to 73.2% by thermo gravimetric analysis. The incorporation of the grafted MWCNTs improved the degree of crystallization and crystal size of PAN nascent fibers, and changed the thermal properties during exothermic processing in an air atmosphere. Morphology analysis and testing of mechanical properties showed that the grafted MWCNT/PAN nascent composite fibers with a more uniform diameter distribution and larger diameter had higher tensile strength and tensile modulus than the control PAN nascent fibers

A Sustainable Closed-Loop Supply Chain Decision Mechanism in the Electronic Sector

In a closed-loop supply chain for electronic products, the manufacturer’s priority is to enhance the residual value of the collected end-of-use product and decide whether to outsource this business to a retailer, a third-party service, or retain it exclusively. In this paper, we constructed three models to study the decision mechanism in a closed-loop supply chain, with different players selected to collect the used product. By comparing the three models, we characterized the conditions under which the manufacturer will benefit most, and we then aimed to determine the best choice for the manufacturer. Our findings show that, when the retailer and the third-party service provider provide equal performance in collecting the used product, the manufacturer will give priority to the third-party service provider if they choose to outsource this business. If the reverse flows managed by the retailer result in a higher payoff for the manufacturer, then the manufacturer will choose to outsource this business to the retailer who will also benefit

N2 electrochemical reduction on two dimensional transition metal monoborides:A density functional theory study

Electrochemical reduction of N2 at ambient conditions is emerging as a promising route and can be powered by sustainable energies. Large overpotential and the competing hydrogen evolution reaction (HER) are the two major issues associated with the N2 reduction. Thus, the development of efficient electrocatalysts with low overpotential is of utmost significance for electrochemical nitrogen reduction reaction (NRR). In this theoretical study, we report a valuable insight toward a novel two dimensional (2D) transition metal monoboride (TMB) material possessing efficient electrocatalysts application for NRR, investigated by density functional theory method. Through systematically exploring the Gibbs free energy of N2 adsorption on the different TMB (TM = Cr, Mn, Fe, Co, Ni and Mo) nanosheets and analyzing adsorption energy of N2H and NH2 species on these catalysts, we found MoB nanosheets may be the optimum choice as an electrocatalyst for NRR. Moreover, our results also indicate that NRR on MoB nanosheets via the enzymatic pathway is the most favored pathway and *NH*NH → *NH*NH2 is potential-limiting step with a very low applied overpotential of 0.14 V. In addition, the limiting potentials of NRR (−0.30 V) and HER (−0.48 V) on MoB nanosheet suggest that NRR is prefer to happen on the catalyst. Overall, this study demonstrates that MoB nanosheets as a novel 2D monolayer, which might be utilized as an efficient electrocatalyst for NRR at ambient conditions.</p

The importance of atomic charge distributions of solid boron material in N2 electrochemical reduction

Searching for efficient metal-free electrocatalysts to convert N2 into NH3 is very important and challenge in chemistry. Here, we have explored the potential application of the metal-free solid α-B12 using as a promising electrocatalyst for N2 reduction reaction (NRR) through a first-principles investigation. We have firstly analysed the charge distributions of the atoms of α-B12, and found it to be amphoteric. Therefore the gas phase N2 molecule gains electrons from negatively charged atoms of α-B12 to form strong interaction with catalyst surface. Further the adsorption of N2 on (0 0 1) surface termination of α-B12 provides evidence that the α-B12 surface can efficiently activate N2 via electron transfer from α-B12 to N2 moiety. Additionally, our calculation results of possible NRR mechanisms of N2 absorbed on α-B12 surface showcased that the enzymatic mechanism is the most feasible reaction pathway with a very low overpotential of 0.20 V. In all, the results indicate that the electron-deficient α-B12 can effectively activate N2 through devoting its electron to N2 and α-B12 can be used as an effective metal-free electrocatalyst for N2 fixation.</p