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Traditional star image identification methods use adjacent stellar angular distances to form identification features. The missed detection of high-magnitude stars due to noise interference affects their identification accuracy. We propose a star image identification method based on perceptual hash features. The multiple Gaussian distribution superposition constructed by stars within a certain range around the center star forms the unique standard identification image of that star, in which the brightness distribution is determined by stellar magnitudes. The perceptual hash feature of the standard identification image is then used as a standard identification feature. The observation feature is extracted from the identification image as-constructed by the star points extracted from the star image. Finally, the observation feature is matched with the standard feature to identify the star image. Simulation results indicate that the proposed method can efficiently identify star images and effectively prevent missed stars from influencing the matching results.

On-demand shared mobility services such as Uber and microtransit are steadily penetrating the worldwide market for traditional dispatched taxi services. Hence, taxi companies are seeking ways to compete. This study mined large-scale mobility data from connected taxis to discover beneficial patterns that may inform strategies to improve dispatch taxi business. It is not practical to manually clean and filter large-scale mobility data that contains GPS information. Therefore, this research contributes and demonstrates an automated method of data cleaning and filtering that is suitable for such types of datasets. The cleaning method defines three filter variables and applies a layered statistical filtering technique to eliminate outlier records that do not contribute to distributions that match expected theoretical distributions of the variables. Chi-squared statistical tests evaluate the quality of the cleaned data by comparing the distribution of the three variables with their expected distributions. The overall cleaning method removed approximately 5% of the data, which consisted of errors that were obvious and others that were poor quality outliers. Subsequently, mining the cleaned data revealed that trip production in Dubai peaks for the case when only the same two drivers operate the same taxi. This finding would not have been possible without access to proprietary data that contains unique identifiers for both drivers and taxis. Datasets that identify individual drivers are not publicly available.

The statistics and analysis of mine gas extraction is very important for mine gas control, which provides a basis for the formulation of mine gas extraction plan. Because of its simple and convenient characteristics, it is favored by the engineering and technical personnel in the coal mine field, and has been widely used, and achieved good results. Based on the statistics of gas drainage in Weijiadi Coal Mine from 2008 to 2018, the characteristics and quantity of gas emission are analyzed according to the statistical results of gas drainage in Weijiadi Coal Mine, and the characteristics of gas emission in the process of driving in the main mining seam are predicted, and the mathematics relations of the length of driving roadway and the quantity of gas emission is obtained.

In view of the coupling problem of gas and coal spontaneous combustion in goaf of 2302 coal mining face in Weijiadi Coal Mine in Jingyuan Coal Area, if the control is not in place, it may cause serious accidents such as gas explosion. By means of fluent simulation, the spontaneous combustion period and oxygen distribution of residual coal in goaf are obtained, and the minimum advancing speed of coal mining face to prevent spontaneous combustion in goaf is calculated to be 1.43m/d. By implementing fire prevention measures such as blocking air leakage in upper and lower corners, grouting and nitrogen injection in goaf, the oxygen concentration in goaf is controlled within 11%, and the spontaneous combustion zone of oxidation is fast. Transferring to asphyxiation zone and preventing the residual coal from firing in goaf are of great significance for ensuring the safety of mine production.

The division of gas geological units in coal mine is the basis of studying the occurrence law of gas geology in coal mine field, which is of great significance to the prediction of regional gas content and gas emission. Taking Weijiadi coalfield in Jingyuan mining area of Gansu Province as an object, this paper divides the coalfield into gas geological units, according to the gas content of coal seams in different regions, targeted gas extraction measures are implemented, gas cascade control is implemented, regional gas abnormal emission is strictly prevented, and mine safety production is ensured.

In Weijiadi Coal Mine, the No.2 coal seam is uncovered by the Donger return air shaft. According to the concept of “regional measures first, local measures supplement”, the measures are taken strictly in the outburst seam, the gas pressure P=0.2MPa and the gas content W=1.4729m3/t in the coal seam are determined by preconstruction prediction drilling, and there are no gas dynamic phenomena such as drilling jam and sticking in the drilling process. It is proved that there is no outburst danger, and then it is implemented according to the local “four in one” outburst prevention measures. The maximum gas pressure determined is 0.2 MPa in the working face, and the validity check is still no outburst danger. Finally, safety protection devices are installed in the working face to ensure the No.2 coal seam to be uncovered smoothly by return air shaft.

Stratigraphic sequence contrast and sequence stratigraphic framework are of great significance for the sedimentary phase and sedimentary systems of coal-accumulating basin. In the coal-bearing basin, the variation of the flooding surface controls the migration law of the coal-concentrating centres within the range. Therefore, the sequence comparison work is crucial to find favorable coal-collecting areas. In addition, studying the position of the coal seam in the sequence stratigraphic framework and carrying out the sequence comparison work in the lateral direction can effectively track the change of the position of the coal seam in the sequence stratum and summarize the law of coal seam accumulation and occurrence, which can be better to plan and guide the exploration and development of coal resources in Longdong coalfield.

In Ad-hoc wireless network, connectivity is a fundamental issue which restricts the design of system protocol. Based on the theory of stochastic geometry, a connectivity model focused on signal-to-interference (SIR) ratio is set up in presence of Nakagami-m fading and interference. This paper derives a close formula of connectivity probability with interference and Nakagami-m fading which is never obtained in previous works. Two-dimension shot-noise theory in stochastic geometry for interference is well applied. The formula is verified by simulation. The results show that the connectivity is affected by the scatter of users, wireless propagation environment, interference and so on.

Removed due to plagiarism

We explored the utility of time-resolved angiography with interleaved stochastic trajectories dynamic contrast-enhanced magnetic resonance imaging (TWIST DCE-MRI), readout segmentation of long variable echo-trains diffusion-weighted magnetic resonance imaging- diffusion-weighted magnetic resonance imaging (RESOLVE-DWI), and echo-planar imaging- diffusion-weighted magnetic resonance imaging (EPI-DWI) for distinguishing between malignant and benign breast lesions. This retrospective analysis included female patients with breast lesions seen at a single center in China between January 2016 and April 2016. Patients were allocated to a benign or malignant group based on pathologic diagnosis. All patients received routine MRI, RESOLVE-DWI, EPI-DWI, and TWIST DCE-T1WI. Variables measured included quantitative parameters (Ktrans, Kep, and Ve), semiquantitative parameters (rate of contrast enhancement for contrast agent inflow [W-in], rate of contrast decay for contrast agent outflow [W-out], and time-to-peak enhancement after contrast agent injection [TTP]) and apparent diffusion coefficient (ADC) values for RESOLVE-DWI (ADCr) and EPI-DWI (ADCe). Receiver-operating characteristic (ROC) curve analysis was used to evaluate the diagnostic utility of each parameter for differentiating malignant from benign breast lesions. A total of 87 patients were included (benign, n = 20; malignant, n = 67). Compared with the benign group, the malignant group had significantly higher Ktrans, Kep and W-in and significantly lower W-out, TTP, ADCe, and ADCr (all P

With the size of transistors scaling down, 3D IC packaging emerged as one of the most promising solutions to achieve system integration on the track of Moore's Law. In this article, we demonstrated a sub-system with one 28nm logic device and two 40nm chips on a 600mm2 silicon interposer with Through-Silicon-Via (TSV) integrating 4 layers of high density interconnects. The packages were assembled using our proprietary CoWoS (Chip on Wafer on Substrate) technology that incorporated 270,000 micro-bump (μBump) and 8,700 C4 bumps. Comprehensive reliability characterization and test methods will be presented. It includes copper interconnect reliability of silicon interposer on EM, SM and IMD TDDB with the presence of TSV. μBump EM and TSV EM are characterized to provide a design guideline for maximum current carrying capability; the EM test methodology was also used to optimize the integrated process, e.g. TSV copper plating, μBump joint, and interface treatment of TSV revealing. Package process optimization, bill of material selectio n and qualificatio n we r e conducted on a 28nm Cu/ELK (Extreme low-K) test vehicle taking Chip-Package-Interaction into consideration. Not only component level package reliability tests were performed, board level Thermal Cycling, Power Cycling and Mechanical Shock tests were also executed to understand the reliability margin and potential failure modes in field use condition. The typical failure modes and mechanisms will be discussed. CoWoS technology is eventually successfully developed with enhanced reliability. The results highlight the importance of a highly integrated 3D IC technology from silicon wafer process to assembly packaging. This work shows that in the new paradigm of 3D IC integration, Si Foundry is positioned at a unique leadership to manage the innovation in Si processes and the improvement of Si assembly operating life.

The potential role of genetic intervention extends from diseases caused by single gene defects, through severe viral infections, to polygenic disorders, such as diabetes mellitus and arteriosclerosis. However, gene therapy can be defined as the introduction and expression of an exogenous gene in human cells for therapeutic benefit, and is conventionally restricted to human diseases associated with single gene defects. There are wider opportunities for genetic intervention and these include strategies to reduce or block gene expression as well as the introduction of nonmammalian genes. The rapid progress in our understanding of some of the molecular mechanisms involved in the pathogenesis of cancer and metabolic disorders, coupled with the development of gene delivery vector technology, has urged us to consider novel genetic approaches to digestive diseases. There is no shortage of ideas and applications for genetic intervention in human diseases, but there are great limitations not only with the efficiency and targeting of the present generation of gene transfer vectors but also with our incomplete understanding of transcription control.

To study the effects of Rheum tanguticum polysaccharide(-1) (RTP(-1)) on ulcerative colitis in rats induced by 2, 4, 6-trinitrophene sulphonic acid (TNBS) and their possible mechanism.RTP1 (200 mg.kg(-1), i.g.) extracted from Rheum tanguticum Maxim. ex Regel was administrated to rats with colitis induced by TNBS for 5 d, 7 d, 10 d and 14 d, respectively. The effects of RTP1 and dexamethasone (DX, 0.2 mg.kg(-1), i.g.) were contrastively investigated. The MPO level and SOD activity were determined by chromatometry. The expansion and protein expression of CD4+T lymphocytes isolated from colon mucosae and mesenteric lymph nodes of colitis rats were performed by immunohistochemical analysis and Western-blot methods.Treatments of RTP1 (200 mg.kg(-1), i.g.) significantly reduced diarrhea, mortality, colon mass, ulcer areas and MPO level in colon mucosae on days 5, 7, 10 and 14 (5.2+/-1.4, 5.4+/-0.7, 5.2+/-1.8, P0.05. 3.4+/-0.8, P0.01. 16.1+/-12.1, P0.01. 31.8+/-8.6, 17.7+/-5.3, 12.7+/-4.1, P0.05). The effects of RTP1 were similar to those noted above in DX group, but there were no immunosuppressive effects of DX in RTP(-1) group, such as body mass loss, thymus and spleen atrophy. The decreased number and down-regulated protein levels of CD4+T cells isolated from the colon of colitis rats treated with RTP1 were found.RTP1 shows significantly protective effects but lower side effects on rats with colitis induced by TNBS. The mechanism may be due to the resistance to over expansion of CD4.

AIM:To study the effects and clinical significance of parenteral hyperalimentation on levels of serum motilin, peptide YY, IgG and glycoproteins in patients with severe ulcerative colitis. METHODS:Eighty-nine patients (males 51,females 38,age 23-57 years) with severe ulcerative colitis were examinated with colonoscope, barium enema, the diagnosis was confirmed histologically. Bacterial infection was excluded through twice consecutive stool cultures. And ameba, schistosomiasis, gastroentertinal cancer and endocrine diseases were also excluded. Ulcerative colitis was found in sigmoid (n =45), descending colon (n =21), colon splenic flexure (n =15) and transverse colon (n =8). Its clinical categories included relapse (n =44), persistent (n =30) and initial (n =15). Parenteral hyperalimentation was applied to patients once diagnosis was made; three days later, fasting venous blood was drawed to test serum motilin (MTL), peptide YY (PYY) and IgG by radioimmunoassy, and serum α1, α2 and γ glycoproteins by electrophoresis. RESULTS:After 4-week period therapy with parental hypernutrition,27 cases (30 %) recovered completely, 48 (54 %) improved, and 14(16 %) failed to therapy, the total effective rate was 84 %. Level of serum MTL, PYY, IgG, and α1-glycoprotein in colitis patients were significant higher than those in control, α 2-glycoprotein was lower than that in control ( P 0.05).Level of serum albumin was increased (P

Strengthen international academic cooperation and exchanges: prospects in the 21st century: Summary of the First World Chinese Congress of Digestion

Endoscopic evaluation of gastrointestinal tract lesions in patients with iron-deficiency anemia

Substance P, vasoactive intestinal peptide, and leu-enkephalin in plasma and gastric juice of patients with precancerous lesions and gastric cancer