Interpretable Machine Learning-Based Influence Factor Identification for 3D Printing Process-Structure Linkages.

Three-dimensional printing technology is a rapid prototyping technology that has been widely used in manufacturing. However, the printing parameters in the 3D printing process have an important impact on the printing effect, so these parameters need to be optimized to obtain the best printing effect. In order to further understand the impact of 3D printing parameters on the printing effect, make theoretical explanations from the dimensions of mathematical models, and clarify the rationality of certain important parameters in previous experience, the purpose of this study is to predict the impact of 3D printing parameters on the printing effect by using machine learning methods. Specifically, we used four machine learning algorithms: SVR (support vector regression): A regression method that uses the principle of structural risk minimization to find a hyperplane in a high-dimensional space that best fits the data, with the goal of minimizing the generalization error bound. Random forest: An ensemble learning method that constructs a multitude of decision trees and outputs the class that is the mode of the classes (classification) or mean prediction (regression) of the individual trees. GBDT (gradient boosting decision tree): An iterative ensemble technique that combines multiple weak prediction models (decision trees) into a strong one by sequentially minimizing the loss function. Each subsequent tree is built to correct the errors of the previous tree. XGB (extreme gradient boosting): An optimized and efficient implementation of gradient boosting that incorporates various techniques to improve the performance of gradient boosting frameworks, such as regularization and sparsity-aware splitting algorithms. The influence of the print parameters on the results under the feature importance and SHAP (Shapley additive explanation) values is compared to determine which parameters have the greatest impact on the print effect. We also used feature importance and SHAP values to compare the importance impact of print parameters on results. In the experiment, we used a dataset with multiple parameters and divided it into a training set and a test set. Through Bayesian optimization and grid search, we determined the best hyperparameters for each algorithm and used the best model to make predictions for the test set. We compare the predictive performance of each model and confirm that the extrusion expansion ratio, elastic modulus, and elongation at break have the greatest influence on the printing effect, which is consistent with the experience. In future, we will continue to delve into methods for optimizing 3D printing parameters and explore how interpretive machine learning can be applied to the 3D printing process to achieve more efficient and reliable printing results.

Investigation on Eigenfrequency of a Cylindrical Shell Resonator under Resonator-Top Trimming Methods.

The eigenfrequency of a resonator plays a significant role in the operation of a cylindrical shell vibrating gyroscope, and trimming is aimed at eliminating the frequency split that is the difference of eigenfrequency between two work modes. In this paper, the effects on eigenfrequency under resonator-top trimming methods that trim the top of the resonator wall are investigated by simulation and experiments. Simulation results show that the eigenfrequency of the trimmed mode increases in the holes-trimming method, whereas it decreases in the grooves-trimming method. At the same time, the untrimmed modes decrease in both holes-trimming and grooves-trimming methods. Moreover, grooves-trimming is more efficient than holes-trimming, which indicates that grooves-trimming can be a primary trimming method, and holes-trimming can be a precision trimming method. The rigidity condition after grooves-trimming is also studied to explain the variation of eigenfrequency. A femtosecond laser is employed in the resonator trimming experiment by the precise ablation of the material. Experimental results are in agreement with the simulation results.

Multiview-video-plus-depth coding based on the advanced video coding standard.

This paper presents a multiview-video-plus-depth coding scheme, which is compatible with the advanced video coding (H.264/AVC) standard and its multiview video coding (MVC) extension. This scheme introduces several encoding and in-loop coding tools for depth and texture video coding, such as depth-based texture motion vector prediction, depth-range-based weighted prediction, joint inter-view depth filtering, and gradual view refresh. The presented coding scheme is submitted to the 3D video coding (3DV) call for proposals (CfP) of the Moving Picture Experts Group standardization committee. When measured with commonly used objective metrics against the MVC anchor, the proposed scheme provides an average bitrate reduction of 26% and 35% for the 3DV CfP test scenarios with two and three views, respectively. The observed bitrate reduction is similar according to an analysis of the results obtained for the subjective tests on the 3DV CfP submissions.

The synthesis and luminescence of europium (III) complex based on deprotonated 1-(4-ethyl-4H-thieno[3,2-b]indol-6-yl)-4,4,4-trifluorobutane-1,3-dionate and 1,10-phenanthroline.

A new ß-diketone ligand, 1-(4-ethyl-4H-thieno[3,2-b]indol-6-yl)-4,4,4-trifluoro-butane-1,3-dione(HL) was synthesized by four steps reaction (Suzuki-Miyaura cross-coupling, Cadogan cyclization, N-ethylation and Claisen condensation reaction) from 1-(4-bromo-3-nitrophenyl)ethanone and thiophen-2-ylboronic acid. Deprotonated ligand (L(-1)) and 1,10-phenanthroline (phen) coordinated to Eu(3+) to obtain a new europium (III) complex, EuL(3)(phen). The complex was characterized by elementary analysis, IR, (1)H NMR, UV-Visible absorption spectroscopy, thermogravimetric analysis (TGA) and photoluminescence (PL) measurements in detail. TGA shows that the decomposition temperature of the complex is up to 320 °C. PL measurement results indicate that the Eu(III) complex exhibit intense red-emission with the characteristic of europium ion. Red LED device was successfully fabricated by employing the complex onto 380 nm-emitting InGaN chip, which shows that the complex can act as red phosphor in combination with 380 nm-emitting chips.

Syntheses, crystal structure and luminescent properties of cadmium complexes based on 2,6-bis(1-phenylbenzimidazol-2-yl)pyridine.

Two cadmium complexes, Cd(bpbp)Cl(2) (complex 1) and [Cd(bpbp)(2)](ClO(4))(2) (complex 2), based on 2,6-bis(1-phenylbenzimidazol-2-yl)pyridine (bpbp), were synthesized and characterized by X-ray single crystal structure analyses. For complex 1: crystal system, monoclinic, space group, C2/c, a=27.427(3)Å, b=13.4495(15)Å, c=14.8381(17)Å, ß=106.635(2)°, V=5244.4(10)Å(3), Z=8. It is a neutral complex. The Cd(II) ion distorted trigonal bipyramidal geometry is five-coordinated by three nitrogen atoms from ligand (bpbp) and two chlorine ions. For complex 2: crystal system, triclinic, space group, P-1, a=13.4791(15)Å, b=13.8506(16)Å, c=16.5839(19)Å, α=94.202(2)°, ß=106.948(2)°, γ=94.872(2)°, V=2935.3(6)Å(3), Z=2. It is an ionic complex. The Cd(II) ion octahedral geometry is six-coordinated by six nitrogen atoms from two ligand (bpbp). Both complexes emit blue luminescence with emission peaks at 420 and 430 nm in solid state and with emission peaks at 415 and 425 nm in DMF solution. In complex 1 absorption spectra, there is not only the free ligand absorption peak at 310 nm, but also shows strong Cd-Cl charge transfer peak at 350 nm in DMF solution.

Estimating the population of female sex workers in two Chinese cities on the basis of the HIV/AIDS behavioural surveillance approach combined with a multiplier method.

OBJECTIVE: To estimate the size of the population of female sex workers (FSWs) on the basis of the HIV/AIDS behavioural surveillance approach in two Chinese cities, using a multiplier method. METHOD: Relevant questions were inserted into the questionnaires given to two behavioural surveillance groups-female attendees of sexually transmitted disease (STD) clinics and FSWs. The size of the FSW population was derived by multiplying the number of FSWs in selected STD clinics during the study period by the proportion of FSW population who reported having attended the selected STD clinics during the same period. RESULTS: The size of the FSW population in the urban area of Xingyi, China, was estimated to be about 2500 (95% CI 2000 to 3400). This accounted for 3.6% of the total urban adult female population. There were an estimated 17,500 FSWs in the urban area of Guiyang, China (95% CI 10,300 to 31,900) or about 3.4% of its total urban adult female population (rounded to the nearest 100). CONCLUSIONS: The multiplier method could be a useful and cost-effective approach to estimate the FSW population, especially suitable in countries where HIV behavioural surveillance has been established in high-risk populations.

Recidivas en pacientes de Lepra MB tratados con 24 meses de MDT en el suroeste de China: Un informe breve / No disponible

Este estudio evalúa el índice de recidivas entre los pacientes de lepra tratados con 24 meses de MDT en el suroeste de China. Para ello se llevó a cabo un estudio retrospectivo de recidivas en esta parte del país. Se diseñó un cuestionario muy detallado para recoger los datos sobre las recidivas entre pacientes MB que habían completado 2 años de tratamiento OMS/MB desde 1989 a 2000. Los datos se obtuvieron sobre 2.517 pacientes multibacilares en 27 países del suroeste de China. Entre los 2.517 pacientes MB, 235 pacientes fallecieron o se dieron de baja durante el seguimiento y 2.374 fueron controlados durante más de 3 años después de completar la MDT. La duración total del seguimiento fue de 20,825 personas-año, con una duración media de 8.27 años por paciente. Se identificaron cinco pacientes con recidivas con un índice acumulado de recidivas de 0-21/1.000 personas-año. Los IB iníciales variaron entre 1.8 a 5. Las recidivas se presentaron entre 48-158 mese después de completar la MDT. El índice de recidivas de los pacientes MB tratados con 24 meses con una pauta OMS/MB se consideró muy bajo después de un largo período de seguimiento

This study investigates the relapse rate among multibacillary leprosy patients treated with 24 months of MDT in south west China. A retrospective relapse survey was conducted in the southwest of China. A detailed questionnaire was designed to collect the data on relapse among MB patients who completed 2 years of the WHO/MB regimen, from 1989 to 2000. The data about 2.517 multibacillary leprosy patients in 27 counties in the southwest of China were collected. Among 2.517 MB patients, 235 patients died or were lost to follow-up and 2.374 were followed up for more than 3 years after completion of MDT. The total duration of follow-up was 20,825 person-years, with a mean duration of 8.27 years per patient. Five patients with relapse were identified with an accumulated relapse rate of 0.21-/1.000 person-years. Their initial Bls ranged from 1.8 to 5. The patients with relapse occurred 48-158 months after the completion of MDT. The relapse rate of MB patients treated with 24 months of the WHO/MB regimen was observed to be very low after long-term follow-up

Recidivas en pacientes de Lepra MB tratados con 24 meses de MDT en el suroeste de China: Un informe breve / No disponible

Este estudio evalúa el índice de recidivas entre los pacientes de lepra tratados con 24 meses de MDT en el suroeste de China. Para ello se llevó a cabo un estudio retrospectivo de recidivas en esta parte del país. Se diseñó un cuestionario muy detallado para recoger los datos sobre las recidivas entre pacientes MB que habían completado 2 años de tratamiento OMS/MB desde 1989 a 2000. Los datos se obtuvieron sobre 2.517 pacientes multibacilares en 27 países del suroeste de China. Entre los 2.517 pacientes MB, 235 pacientes fallecieron o se dieron de baja durante el seguimiento y 2.374 fueron controlados durante más de 3 años después de completar la MDT. La duración total del seguimiento fue de 20,825 personas-año, con una duración media de 8.27 años por paciente. Se identificaron cinco pacientes con recidivas con un índice acumulado de recidivas de 0-21/1.000 personas-año. Los IB iníciales variaron entre 1.8 a 5. Las recidivas se presentaron entre 48-158 mese después de completar la MDT. El índice de recidivas de los pacientes MB tratados con 24 meses con una pauta OMS/MB se consideró muy bajo después de un largo período de seguimiento (AU)

This study investigates the relapse rate among multibacillary leprosy patients treated with 24 months of MDT in south west China. A retrospective relapse survey was conducted in the southwest of China. A detailed questionnaire was designed to collect the data on relapse among MB patients who completed 2 years of the WHO/MB regimen, from 1989 to 2000. The data about 2.517 multibacillary leprosy patients in 27 counties in the southwest of China were collected. Among 2.517 MB patients, 235 patients died or were lost to follow-up and 2.374 were followed up for more than 3 years after completion of MDT. The total duration of follow-up was 20,825 person-years, with a mean duration of 8.27 years per patient. Five patients with relapse were identified with an accumulated relapse rate of 0.21-/1.000 person-years. Their initial Bls ranged from 1.8 to 5. The patients with relapse occurred 48-158 months after the completion of MDT. The relapse rate of MB patients treated with 24 months of the WHO/MB regimen was observed to be very low after long-term follow-up (AU)

Relapse in MB leprosy patients treated with 24 months of MDT in south west China: a short report.

This study investigates the relapse rate among multibacillary leprosy patients treated with 24 months of MDT in south west China. A retrospective relapse survey was conducted in the southwest of China. A detailed questionnaire was designed to collect the data on relapse among MB patients who completed 2 years of the WHO/MB regimen, from 1989 to 2000. The data about 2517 multibacillary leprosy patients in 27 counties in the southwest of China were collected. Among 2517 MB patients, 235 patients died or were lost to follow-up and 2374 were followed up for more than 3 years after completion of MDT. The total duration of follow-up was 20,825 person-years, with a mean duration of 8.27 years per patient. Five patients with relapse were identified with an accumulated relapse rate of 0.21/1000 person-years. Their initial BIs ranged from 1.8 to 5. The patients with relapse occurred 48-158 months after the completion of MDT. The relapse rate of MB patients treated with 24 months of the WHO/MB regimen was observed to be very low after long-term follow-up.