The Discrete-Time Bulk-Service Geo/Geo/1

This paper deals with a discrete-time bulk-service Geo/Geo/1 queueing system with infinite buffer space and multiple working vacations. Considering an early arrival system, as soon as the server empties the system in a regular busy period, he leaves the system and takes a working vacation for a random duration at time n. The service times both in a working vacation and in a busy period and the vacation times are assumed to be geometrically distributed. By using embedded Markov chain approach and difference operator method, queue length of the whole system at random slots and the waiting time for an arriving customer are obtained. The queue length distributions of the outside observer’s observation epoch are investigated. Numerical experiment is performed to validate the analytical results

Research on Risk Prediction and Early Warning of Human Resource Management Based on Machine Learning and Ontology Reasoning

Talent is the first resource, the development of the enterprise to retain key talent is essential, the main research is based on machine learning and ontological reasoning, human resources analysis and management risk prediction and early warning methods, first of all, according to the specific situation and the target case, through the calculation of the similarity of the concept name and attribute of the similarity assessment of the source case in the case library, the matching of knowledge-based employees of the company\u27s case for the similarity prediction and human resources management risk prediction research. Then, according to the evaluation results, we can find out the most suitable job matches in specific risk problems and situations. This is a solution to the target cases and criteria for companies to evaluate candidates. Second, we have successfully developed and implemented a prediction model that applies machine learning to the early warning study of risk prediction for HR management. The model is optimized with a cross-validation function, and the convergence of the model training is accelerated by the regularization of Newton\u27s iterative method. Finally, our prediction model achieved 82% yield. Ontological reasoning and machine learning are promising in human resource management risk prediction and warning, which is proved by the high accuracy rate verified by examples. Finally, we analyze the proposed results of HRM risk prediction and early warning to contribute to the improvement of risk control and suggest measures for possible risks

GI/Geom/1/N/MWV queue with changeover time and searching for the optimum service rate in working vacation period

AbstractIn this paper, we consider a finite buffer size discrete-time multiple working vacation queue with changeover time. Employing the supplementary variable and embedded Markov chain techniques, we derive the steady state system length distributions at different time epochs. Based on the various system length distributions, the blocking probability, probability mass function of sojourn time and other performance measures along with some numerical examples have been discussed. Then, we use the parabolic method to search the optimum value of the service rate in working vacation period under a given cost structure

Star edge coloring of K2,t K_{2, t} -free planar graphs

The star chromatic index of a graph $G$, denoted by $\chi{'}_{st}(G)$, is the smallest number of colors required to properly color $E(G)$ such that every connected bicolored subgraph is a path with no more than three edges. A graph is $K_{2, t}$-free if it contains no $K_{2, t}$ as a subgraph. This paper proves that every $K_{2, t}$-free planar graph $G$ satisfies $\chi_{st}'(G)\le 1.5\Delta +20t+20$, which is sharp up to the constant term. In particular, our result provides a common generalization of previous results on star edge coloring of outerplanar graphs by Bezegová et al.(2016) and of $C_4$-free planar graphs by Wang et al.(2018), as those graphs are subclasses of $K_{2, 3}$-free planar graphs

Genetic testing of PAX8 mutations associated with thyroid dysgenesis in Chinese congenital hypothyroidism patients

Introduction: Thyroid dysgenesis (TD) is the main cause of congenital hypothyroidism (CH), affecting nearly 1 in 2000–3000 newborns worldwide, as the most common neonatal endocrine disorder. Paired box gene 8 (PAX8), expressed during all stages of thyroid follicular cell, plays a key role in thyroid morphogenesis by a complex regulatory network. In conclusion, the genetic mechanism of PAX8 mutant in TD is still ambiguous; therefore, further research is needed. Material and methods: Blood samples were collected from 289 TD patients in Shandong Province, China. Genomic DNA was extracted from peripheral blood. All the exons of PAX8 along with their exon-intro boundaries were amplified by PCR and analysed by Sanger sequencing. Results: We identified three novel PAX8 nonsense mutations in three patients by sequence analysis of PAX8: Patient 1 (c.285C>G, p.Tyr95Ter), Patient 2 (c.747T>G, p.Tyr249Ter), and Patient 3 (c.786C>A, p.Tyr262Ter). All the three patients carrying PAX8 variants had obvious clinical phenotypes of thyroid anomaly, such as hypoplasia and athyreosis. Conclusion: We conducted the largest worldwide PAX8 mutation screening so far in TD patients. Three presumably pathogenic PAX8 mutations were detected in 289 TD cases for the first time, showing the mutation rate of PAX8 is 1.04% in Chinese TD patients. In addition, our study expands the gene mutation spectrum of TD

Analysis and Radiometric Calibration for Backscatter Intensity of Hyperspectral LiDAR Caused by Incident Angle Effect

Hyperspectral LiDAR (HSL) is a new remote sensing detection method with high spatial and spectral information detection ability. In the process of laser scanning, the laser echo intensity is affected by many factors. Therefore, it is necessary to calibrate the backscatter intensity data of HSL. Laser incidence angle is one of the important factors that affect the backscatter intensity of the target. This paper studied the radiometric calibration method of incidence angle effect for HSL. The reflectance of natural surfaces can be simulated as a combination of specular reflection and diffuse reflection. The linear combination of the Lambertian model and Beckmann model provides a comprehensive theory that can be applied to various surface conditions, from glossy to rough surfaces. Therefore, an adaptive threshold radiometric calibration method (Lambertian-Beckmann model) is proposed to solve the problem caused by the incident angle effect. The relationship between backscatter intensity and incident angle of HSL is studied by combining theory with experiments, and the model successfully quantifies the difference between diffuse and specular reflectance coefficients. Compared with the Lambertian model, the proposed model has higher calibration accuracy, and the average improvement rate to the samples in this study was 22.67%. Compared with the results before calibration with the incidence angle of less than 70 degrees, the average improvement rate of the Lambertian-Beckmann model was 62.26%. Moreover, we also found that the green leaves have an obvious specular reflection effect near 650-720 nm, which might be related to the inner microstructure of chlorophyll. The Lambertian-Beckmann model was more helpful to the calibration of leaves in the visible wavelength range. This is a meaningful and a breakthrough exploration for HSL.Peer reviewe

Aggregation‐induced emission luminogen: A new perspective in the photo‐degradation of organic pollutants

Both the variety and uniqueness of organic semiconductors has contributed to the rapid development of environmental engineering applications and renewable fuel production, typified by the photodegradation of organic pollutants or water splitting. This paper presents a rare example of an aggregation‐induced emission luminogen as a highly efficient photocatalyst for pollutant decomposition in an environmentally relevant application. Under irradiation, the tetraphenylethene‐based AIEgen (TPE‐Ca) exhibited high photo‐degradation efficiency of up to 98.7% of Rhodamine B (RhB) in aqueous solution. The possible photocatalytic mechanism was studied by electron paramagnetic resonance and X‐ray photoelectron spectroscopy spectra, electrochemistry, thermal imaging technology, ultra‐performance liquid chromatography and high‐definition mass spectrometry, as well as by density functional theory calculations. Among the many diverse AIEgens, this is the first AIEgen to be developed as a photocatalyst for the degradation of organic pollutants. This research will open up new avenues for AIEgens research, particularly for applications of environmental relevance