Nonuniform Sparse Data Clustering Cascade Algorithm Based on Dynamic Cumulative Entropy

A small amount of prior knowledge and randomly chosen initial cluster centers have a direct impact on the accuracy of the performance of iterative clustering algorithm. In this paper we propose a new algorithm to compute initial cluster centers for k-means clustering and the best number of the clusters with little prior knowledge and optimize clustering result. It constructs the Euclidean distance control factor based on aggregation density sparse degree to select the initial cluster center of nonuniform sparse data and obtains initial data clusters by multidimensional diffusion density distribution. Multiobjective clustering approach based on dynamic cumulative entropy is adopted to optimize the initial data clusters and the best number of the clusters. The experimental results show that the newly proposed algorithm has good performance to obtain the initial cluster centers for the k-means algorithm and it effectively improves the clustering accuracy of nonuniform sparse data by about 5%

A Novel Traffic Control Scheme for Multi-Layered Satellite Network Based on Chain Reaction Model

Multi-Layered Satellite Network (MLSN) is a kind of delay tolerant network with characters of intermittent connection, long packet queuing time, complex and uncertain delay time, etc. The call congestion rate of new business is higher in delay tolerant network which leads to the reduction of communication quality and the high packet loss rate. The existing traffic control scheme is hard to meet the individual requirements of new business. It becomes more and more important to study the most effective traffic control scheme so as to increase the satellite bandwidth utilization. According to the nuclear chain reaction of atomic physics, a novel traffic control method based on chain reaction model (TCCR) is presented in this paper to realize dynamic data transmission and control for MLSN. The optimal flow distribution scheme will be obtained by analyzing the network transmission information in this algorithm. Simulation by OPENT is done which proves that TCCR can obviously improve the network total throughput, shorten link transmission delay, and reduce packet loss rate of MLSN

Distribution characteristics and accumulation mechanism of carbon dioxide gas reservoirs in the Pearl River Mouth Basin

Exploration practice has revealed abundant carbon dioxide gas reservoirs in many depressions of the Pearl River Mouth Basin, South China Sea with a CO2 content as high as 90%. These CO2 reservoirscan either directly displace the early oil reservoirs or affect the oil and gas charging scale, which further increases exploration risk. Based on the comprehensive analysis of drilling data, geochemical analysis data, gravity and magnetic research results, the migration and accumulation conditions of the CO2 reservoirs have been investigated. Our results suggest that CO2 in the Pearl River Mouth Basin is sourced by inorganic mantle, and its distribution locations are controlled by regional caprocks and reservoirs. CO2 is mainly distributed in upper Oligocene to lower Miocene strata and the overlying strata, with its contents gradually decreasing upwards. Meanwhile, the distribution of inorganic mantle source CO2 is greatly controlled by the fault system, and its distribution locations have a close relationship with the ranges of basement faults and igneous rocks. The inorganic CO2 gas is sourced by the degassing of mantle-derived magma. Its vertical migration process is mainly controlled by different scales faults, especially the regional abyssal faults. Therefore, it can be concluded that mantle-derived magma activity and fault systems are the main controlling factors for the accumulation processes of CO2 reservoirs. The mechanisms of mantle-derived CO2 migration and accumulation can be summarized into two types by structural differences. In the northern depression zone, CO2 migrates along deep faults step by step to the upper and middle crust to form a "transfer station". By contrast, the detachment system developed in the Zhu 2 Depression, and CO2 migrates along the detachment plane to upper strata

Simultaneous determination of nineteen major components in Qi She Pill by ultra-high-performance liquid chromatography–tandem mass spectrometry

Qi She Pill (QSP) is a traditional Chinese medicine (TCM) prescription that has been used in treating cervical spondylosis radiculopathy for many years. In this study, a simple and sensitive method using ultra-high-performance liquid chromatography–tandem mass spectrometry (UHPLC–MS/MS) on a reverse-phase C18 column was developed for the simultaneous determination of the 19 major components in QSP. We found that the optimum mobile phase for gradient elution was 0.1% formic acid and methanol. The correlation coefficients of all calibration curves were greater than 0.99. Recoveries measured at three concentration levels varied from 95.43% to 102.35%. Relative standard deviations of intra- and inter-day precisions were less than 4.45%. After successfully validating our method, we then applied it to the quantification of 19 components in QSP products to show that this method provides a new standard in quality assessment of TCM prescriptions containing multiple bioactive components

In Vivo and in Situ Activated Aggregation-Induced Emission Probes for Sensitive Tumor Imaging Using Tetraphenylethene-Functionalized Trimethincyanines-Encapsulated Liposomes

The design and exploration of fluorescent probes with high-sensitivity and low-background are essential for noninvasive optical molecular imaging. The in vivo and in situ activated aggregation-induced emission (AIE) probes were found to be ideal for achieving higher signal-to-background ratios for tumor detections. We herein developed novel tetraphenylethene-encapsulated liposomes (TPE-LPs) constructed by loading TPE-trimethincyanine into liposomes for the first time, and the probes were applied to tumor bioimaging in vivo. TPE-functionalized trimethincyanines were synthesized with a new and efficient one-pot reaction. In TPE-LPs, TPE-functionalized bicarboxylic acids benzoindole trimethinecyanine (TPE-BICOOH) fluorophores were found to be well dispersed in lipid bilayers (with non-restricted rotation) during the blood circulation, and then aggregated (with restriction of intramolecular rotation) upon liposome rupture in the tumor tissue, achieving a low-background and high-target signal for tumor imaging. The in situ activated AIE probes not only had great accumulation at the tumor site after intravenous injection in 4T1 tumor-bearing mice but also demonstrated excellent signal-to-background ratios, as well as low cytotoxicity and excellent biocompatibility. The proposed strategy is believed to be a simple and powerful tool for the sensitive detection of tumors