An Affinity Propagation Clustering Algorithm for Mixed Numeric and Categorical Datasets

Clustering has been widely used in different fields of science, technology, social science, and so forth. In real world, numeric as well as categorical features are usually used to describe the data objects. Accordingly, many clustering methods can process datasets that are either numeric or categorical. Recently, algorithms that can handle the mixed data clustering problems have been developed. Affinity propagation (AP) algorithm is an exemplar-based clustering method which has demonstrated good performance on a wide variety of datasets. However, it has limitations on processing mixed datasets. In this paper, we propose a novel similarity measure for mixed type datasets and an adaptive AP clustering algorithm is proposed to cluster the mixed datasets. Several real world datasets are studied to evaluate the performance of the proposed algorithm. Comparisons with other clustering algorithms demonstrate that the proposed method works well not only on mixed datasets but also on pure numeric and categorical datasets

Simulation study of the impact of quantum confinement on the electrostatically driven oerformance of n-type nanowire transistors

In this paper, we have studied the impact of quantum confinement on the performance of n-type silicon nanowire transistors (NWTs) for application in advanced CMOS technologies. The 3-D drift-diffusion simulations based on the density gradient approach that has been calibrated with respect to the solution of the Schrödinger equation in 2-D cross sections along the direction of the transport are presented. The simulated NWTs have cross sections and dimensional characteristics representative of the transistors expected at a 7-nm CMOS technology. Different gate lengths, cross-sectional shapes, spacer thicknesses, and doping steepness were considered. We have studied the impact of the quantum corrections on the gate capacitance, mobile charge in the channel, drain-induced barrier lowering, and subthreshold slope. The mobile charge to gate capacitance ratio, which is an indicator of the intrinsic speed of the NWTs, is also investigated. We have also estimated the optimal gate length for different NWT design conditions

A Simple Model to Predict Machined Depth and Surface Profile for Picosecond Laser Surface Texturing

A simple mathematical model was developed to predict the machined depth and surface profile in laser surface texturing of micro-channels using a picosecond laser. Fabrication of micro-craters with pulse trains of different numbers was initially performed. Two baseline values from the created micro-craters were used to calculate the estimated simulation parameters. Thereafter, the depths and profiles with various scanning speeds or adjacent intervals were simulated using the developed model and calculated parameters. Corresponding experiments were conducted to validate the developed mathematical model. An excellent agreement was obtained for the predicted and experimental depths and surface profiles. The machined depth decreased with the increase of scanning speed or adjacent interval

High-power semiconductor laser array packaged on microchannel cooler using gold-tin soldering technology

High power semiconductor laser arrays have found increased applications in many fields. In this work, a hard soldering microchannel cooler (HSMCC) technology was developed for packaging high power diode laser array. Numerical simulations of the thermal behavior characteristics of hard solder and indium solder MCC-packaged diode lasers were conducted and analyzed. Based on the simulated results, a series of high power HSMCC packaged diode laser arrays were fabricated and characterized. The test and statistical results indicated that under the same output power the HSMCC packaged laser bar has lower smile and high reliability in comparison with the conventional copper MCC packaged laser bar using indium soldering technology

Evaluation of substrate clogging in a full-scale horizontal subsurface flow treatment wetland using electrical resistivity tomography with an optimized electrode configuration

This study investigated the spatial distribution of clogging matter in a full-scale horizontal subsurface flow treatment wetland (HSSF TW) based on an electrical resistivity tomography (ERT) method, comparing the performance of two different electrode configurations (i.e., Schlumberger and Wenner arrays). The results indicated that during the draining phase, the substrate apparent resistivities of the full-scale HSSF TWs were negatively correlated with the clogging matter fraction (v/v), and a functional relationship between the two parameters was established using a first-order k-C* model. The detected clogging matter fraction (v/v) based on the Schlumberger array showed higher accuracy (linear slope = 0.900, R-squared = 0.902) than the Wenner array (linear slope = 0.685, R-squared = 0.685). Most of the severe substrate clogging in the full-scale HSSF TW occurred within a 10-m flow distance, and the distribution of the clogging matter showed different characteristics at different substrate depths. From a cross section positioned 1 m from the inlet, the average clogging matter fraction (v/v) at a 0–0.30 m depth (23.1 ± 14.9%) was significantly higher than that at a 0.30–0.80 m depth (5.0 ± 2.1%). The clogging matter at a 5-m flow distance was evenly distributed at different substrate depths. Only a few localized clogging zones were observed in the cross section at a 10-m flow distance. This study provided an accurate and feasible method for investigating the volume fraction of clogging matters containing different organic contents and demonstrates the spatial heterogeneity of clogging matter in HSSF TWs.This research was funded by the Shandong Province Key Research and Development Program , China (Major Scientific and Technologica lInnovation Project) (No. 2020CXGC011406 & No . 2019JZZY010411), National Science Foundation of China (Nos . 51878388 , 52170043 & 42107230), Natural Science Foundation of Shandong Province (No. ZR2020YQ42), and Future Plan for Young Scholar of Shandong University .Peer ReviewedPostprint (author's final draft

Study on phytoremediation for heavy metal contaminated sediments by hydrophytes

The remediation performances of heavy metals contaminaged sediment by hydrophytes including Alternanthera Philoxeroides, Canna indica L., Nymphaea tetragona, Typha orientalis, Phragmites australis, Phragmites australis, Hydrilla verticillata, Cyperus alternifolius L., Eichhornia crassipes, Acorus tatarinowii, Digitaria sanguinalis (L.) Scop were investigated through batch pot experiments. The results showed that the enrichment effect of Pb was better in Alternanthera Philoxeroides and Acorus tatarinowii with the BCFs of 4.42 and 1.22, and the TFs of 7.84 and 4.23, respectively. The Cr enrichment effects by Nymphaea tetragona, Hydrilla verticillata and Eichhornia crassipes (Mart.) Solms were better, which BCFs were 2.69, 1.91 and 3.71, and which TFs were 7.93, 2.07 and 2.18, respectively

Arsenic content in the Jie River and its release behaviour from river sediments

Water and sediment samples of Jie River, China were collected and analyzed. The results showed that the average arsenic volume of water sample was 0.42 mg L-1 present in the Jie River. Among the riverway, the arsenic volume and pH kept rising with the flow. Standard leaching experiments showed the leachability of the sediments was lower than the hazardous materials permitted threshold volume but the leaching liquid exceeded the environmental quality standard for surface water which means the sediments might be a source to leach arsenic into aqueous system. In order to figure out the actual situation, simulated leaching experiments were performed. The results revealed that the sediments leaching could aggravate the water quality which was mostly influenced by the agitation and temperature. Solidification procedure was tested and suggested that with clean sand paved on the sediment, the amount of leaching arsenic will decrease 77.89%. Thus, it is of great help to apply cleaned sediments to remediate the contaminated sediments to reduce the leaching of arsenic into the aqueous system