Segmental Distribution Research Articles

Influence of structural form on hydration-heat-induced temperature rise of precast concrete lining segments for a metro transit station

This paper describes research on the effect of structural form on hydration-heat-related changes in large-scale precast concrete lining segments. These segments of mass concrete were used in the construction of an underground metro transit station in Changchun, China, a location where conventional cast-in-place construction is interrupted for months by cold winter weather. Heat of hydration analysis of closed-cavity and solid lining segments was conducted using the finite element method (FEM). Two ambient temperatures of 25°C and 10°C (77°F and 50°F) were selected to simulate segment manufacturing conditions in summer and winter, respectively. The FEM and selected parameters were found to be reasonable because the numerical predictions and experimental observations from the closed-cavity segment were consistent. At both of the ambient temperatures, the maximum internal concrete temperature of the closed-cavity segment was much lower than that in the solid one and the temperature distribution in the closed-cavity segment was more uniform. As a result, thermal stress was lower in the closed-cavity segment than in the solid segment, which reduced the risk for cracking. The closed-cavity form of the lining segments enhanced the structural integrity and durability, and the ability to prefabricate these segments in cold ambient temperatures effectively accelerated construction on this project.

Transfer learning for robust urban network-wide traffic volume estimation with uncertain detector deployment scheme

<abstract> <p>Real-time and accurate network-wide traffic volume estimation/detection is an essential part of urban transport system planning and management. As it is impractical to install detectors on every road segment of the city network, methods on the network-wide flow estimation based on limited detector data are of considerable significance. However, when the plan of detector deployment is uncertain, existing methods are unsuitable to be directly used. In this study, a transfer component analysis (TCA)-based network-wide volume estimation model, considering the different traffic volume distributions of road segments and transforming traffic features into common data space, is proposed. Moreover, this study applied taxi GPS (global positioning system) data and cellular signaling data with the same spatio-temporal coverage to improve feature extraction. In numerical experiments, the robustness and stability of the proposed network-wide estimation method outperformed other baselines in the two subnetworks selected from the urban centers and suburbs.</p> </abstract>

Трансформация цепей поставок в ситуации глобального кризиса

The article is devoted to the process of transformation of international supply chains in a crisis caused by the overlapping of three powerful negative factors: the consequences of the financial and economic crisis of 2008, of the COVID-19 pandemic and of economic sanctions against the Russian Federation. The authors point out that the destabilizing effect of the crisis primarily affected the functioning of the global supply chain system, one of the main components of the world economy. Under the current conditions, the normal functioning of supply chains is disrupted or is becoming nearly impossible due to disruptions in transport and commodity flows, denials of service, unpredictable delays, significant fluctuations in prices for goods and services, etc. The article emphasizes that the system of criteria and the basic principles of supply chain management, which have been established over decades of relatively stable development, are currently ineffective or completely inapplicable and need to be substantially adjusted. The theoretical recommendations identified by the authors are compared with the results of their survey of 240 Russian companies representing industry, distribution of goods, retail, logistics services and other segments. The survey made it possible to identify both the main negative factors affecting the supply chains and the most significant course of action for Russian business in order to reconfigure the import in crisis conditions. Based on the available theoretical and empirical data, the authors make an assumption about the new characteristics of international supply chains that they will acquire in the foreseeable future, both in terms of the general ideology of management and operation, and in terms of operational decisions.

Identification of runs of homozygosity in Western honey bees (Apis mellifera) using whole-genome sequencing data.

Runs of homozygosity (ROH) are continuous homozygous segments that arise through the transmission of haplotypes that are identical by descent. The length and distribution of ROH segments provide insights into the genetic diversity of populations and can be associated with selection signatures. Here, we analyzed reconstructed whole-genome queen genotypes, from a pool-seq data experiment including 265 Western honeybee colonies from Apis mellifera mellifera and Apis mellifera carnica. Integrating individual ROH patterns and admixture levels in a dynamic population network visualization allowed us to ascertain major differences between the two subspecies. Within A. m. mellifera, we identified well-defined substructures according to the genetic origin of the queens. Despite the current applied conservation efforts, we pinpointed 79 admixed queens. Genomic inbreeding (F ROH) strongly varied within and between the identified subpopulations. Conserved A. m. mellifera from Switzerland had the highest mean F ROH (3.39%), while queens originating from a conservation area in France, which were also highly admixed, showed significantly lower F ROH (0.45%). The majority of A. m. carnica queens were also highly admixed, except 12 purebred queens with a mean F ROH of 2.33%. Within the breed-specific ROH islands, we identified 14 coding genes for A. m. mellifera and five for A. m. carnica, respectively. Local adaption of A. m. mellifera could be suggested by the identification of genes involved in the response to ultraviolet light (Crh-BP, Uvop) and body size (Hex70a, Hex70b), while the A. m. carnica specific genes Cpr3 and Cpr4 are most likely associated with the lighter striping pattern, a morphological phenotype expected in this subspecies. We demonstrated that queen genotypes derived from pooled workers are useful tool to unravel the population dynamics in A. mellifera and provide fundamental information to conserve native honey bees.

Study on Crack Propagation Parameters of Tunnel Lining Structure Based on Peridynamics

The numerical simulation results utilizing the Peridynamics (PD) method reveal that the initial crack and crack propagation of the tunnel concrete lining structure agree with the experimental data compared to the Japanese prototype lining test. The load structure model takes into account the cracking process and distribution of the lining segment under the influence of local bias pressure and lining thickness. In addition, the influence of preset cracks and lining section form on the crack propagation of the concrete lining model is studied. This study evaluates the stability and sustainability of tunnel structure by the Peridynamics method, which provides a reference for the analysis of the causes of lining cracks, and also lays a foundation for the prevention, reinforcement and repair of tunnel lining cracks.

Three segments distribution of gas diffusion layer porosity in a proton exchange membrane fuel cell

Three segments distribution of gas diffusion layer porosity in a proton exchange membrane fuel cell

Systematical Analysis and Pathological Classification of Breast Cancer from Mammographic Images with Using Specific Machine Learning Methods

For years, breast cancer has been a serious problem and malignant tumor case primarily causes death of women all around the world. In this paper, a computer based breast tumor analysis and pathological case classification system has been achieved and some novelties are included to the image processing methods, especially in segmentation and base frequency distribution acquisition of the processed image and classification part. First, the possible noises and artifacts are eliminated by using common filtering. Second, the filtered images are segmented with integrating gray level Image Processing methods. Then, these images (ROIs) are converted to the base frequency distribution images with using Fast Fourier Transform (FFT) and Lab&HSV color spaces. The most important key for these images is frequency distribution can be obtained with specific color tones and totally 100 images (50 benign-50 malignant) are accumulated to fed the two different Machine Learning models in literature such as Probabilistic Neural Network as Learning Vector Quantization (LVQ) and Support Vector Regression (SVR) for classification of Benign and Malignant cases without the need for additional medical data. Then the performance of the proposed system is analyzed with 30 different test images (15 benign-15 malignant) according to the metrics like accuracy, sensitivity, specificity, precision, F-score and area under the ROC curve (AUC score). The experimental results on the open access mammogram image set show that discriminating between Benign and Malignant cases can be achieved with an important success rate as 91.38% with LVQ and %.92 with SVR.

Unveiling Qzone: A measurement study of a large-scale online social network

Nowadays, Online Social Network (OSN) is very important in maintaining relationships and disseminating information. Qzone, as one of the most popular OSNs in China, lacks detailed quantitative measurement and analysis. To the best of our knowledge, we are the first to conduct a large-scale measurement on Qzone. Firstly, we develop a dedicated Qzone Crawler System (Qzone-CS) and collect over a billion user and topology data. Subsequently, we measure user behavior and network topology characteristics by analyzing their posting and interactive behaviors. The results show that: 1) the temporal distribution of user behavior follows the periodic distribution, while user posting behavior follows the segmented power-law distribution. Among all the user behaviors on Qzone, the probability of posting Shuoshuo is the highest. Meanwhile, users prefer to comment on others’ blogs than to forward them. Unlike other OSNs, Qzone is a relatively closed system, which is not conducive to the dissemination of information. 2) Qzone is a small-world and scale-free community; the friendship network has higher clustering characteristic compared with the interactive network; out-degree in the interactive network has an obvious correlation with in-degree; and unlike other OSNs, Qzone is a heterogeneous network. Our results can help researchers better understand the user behavior and network topology characteristics of Qzone.

Role of cardiac magnetic resonance in the differential diagnosis between arrhythmogenic cardiomyopathy with left ventricular involvement and previous infectious myocarditis.

AimsArrhythmogenic cardiomyopathy with left ventricular involvement (ACM-LV), particularly in case of isolated left ventricular involvement (i.e. left dominant arrhythmogenic cardiomyopathy, LDAC) and previous infectious myocarditis (pIM) may have overlapping clinical and cardiac magnetic resonance (CMR) features. To date, there are no validated CMR criteria for the differential diagnosis between these conditions. The present study aimed to identify CMR characteristics to distinguish ACM-LV from pIM. Methods and resultsThis observational, retrospective, single-centre study included 30 pIM patients and 30 ACM-LV patients. In ACM-LV patients CMR was performed at diagnosis; in patients with pIM, CMR was performed six months after acute infection. CMR analysis included quantitative assessment of left ventricle (LV) volumes, systolic function and wall thicknesses, qualitative and quantitative assessment of late gadolinium enhancement (LGE) sequences. Compared with pIM, ACM-LV patients showed slightly larger LV volumes, more frequent regional wall motion anomalies and reduced wall thicknesses. ACM-LV patients had higher amounts of LV LGE and extension. Notably, the LDAC subgroup had the highest amount of LV LGE. LV LGE amount > 15 g and a LV LGE percentage > 30% of LV mass discriminated ACM-LV from pIM with a 100% specificity. LGE segmental distribution was superimposable among the groups, except for septal segments that were more frequently involved in ACM-LV and LDAC patients. ConclusionsA great extension of LV LGE (a cut-off of LGE >15 g and a percentage above 30% of LV LGE in relation to total myocardial mass) discriminates ACM-LV from pIM with extremely high specificity.

Evaluation of segmental distribution of liver metastases in colorectal carcinomas by computed tomography

Objective: We aimed to investigate the relationship between the localization of colorectal carcinomas and the topographic distribution of metastatic liver lesions. Material and Methods: Patients diagnosed with colorectal cancer and metastatic liver lesions constituted the target population of this study. Demographic data, primary tumor localization, and data regarding liver metastases were retrieved and retrospectively reviewed. Patient files, including endoscopy and computerized tomography reports, were the primary data source. In addition, data concerning segmental localization of the metastatic liver lesions based on the Couinaud classification were collected. Results: Ninety-six patients were diagnosed with colorectal cancer with liver metastases during the study period. A total of 251 metastases were detected. The number of metastases was 169 (67.3%) in the right and 80 (31.9%) in the left lobe (p0.05). Conclusion: Liver metastases of colorectal cancer are significantly more common in the right lobe than the left lobe, irrespective of the location of the colorectal tumor. Segment VIII of the right lobe is the main target of the metastases.

Analysis on the interactions between the first introns and other introns in mitochondrial ribosomal protein genes.

It is realized that the first intron plays a key role in regulating gene expression, and the interactions between the first introns and other introns must be related to the regulation of gene expression. In this paper, the sequences of mitochondrial ribosomal protein genes were selected as the samples, based on the Smith-Waterman method, the optimal matched segments between the first intron and the reverse complementary sequences of other introns of each gene were obtained, and the characteristics of the optimal matched segments were analyzed. The results showed that the lengths and the ranges of length distributions of the optimal matched segments are increased along with the evolution of eukaryotes. For the distributions of the optimal matched segments with different GC contents, the peak values are decreased along with the evolution of eukaryotes, but the corresponding GC content of the peak values are increased along with the evolution of eukaryotes, it means most introns of higher organisms interact with each other though weak bonds binding. By comparing the lengths and matching rates of optimal matched segments with those of siRNA and miRNA, it is found that some optimal matched segments may be related to non-coding RNA with special biological functions, just like siRNA and miRNA, they may play an important role in the process of gene expression and regulation. For the relative position of the optimal matched segments, the peaks of relative position distributions of optimal matched segments are increased during the evolution of eukaryotes, and the positions of the first two peaks exhibit significant conservatism.

Automated Segmentation and Morphological Characterization of Hepatic Steatosis and Correlation with Histopathology

Prevalence of nonalcoholic fatty liver disease (NAFLD) has increased to 25% of the world population. Hepatic steatosis is a hallmark feature of NAFLD and is assessed histologically usingvisual and ordinal fat grading criteria (0-3) from the Nonalcoholic Steatohepatitis (NASH) Clinical Research Network (CRN) scoring system. The purpose of this study is to automatically segment and extract morphological characteristics and distributions of fat droplets (FDs) on liver histology images and find associations with severity of steatosis. A previously published human cohort of 68 NASH candidates was graded for steatosis by an experienced pathologist using the Fat CRN grading system. The automated segmentation algorithm quantified fat fraction (FF) and fat-affected hepatocyte ratio (FHR), extracted fat morphology by calculating radius and circularity of FDs, and examined FDs distribution and heterogeneity using nearest neighbor distance and regional isotropy. Regression analysis and Spearman correlation (ρ) yielded high correlations for radius (R2=0.86, ρ=0.72), nearest neighbor distance (R2=0.82, ρ=-0.82), regional isotropy (R2=0.84, ρ=0.74), and FHR (R2=0.90, ρ=0.85), and low correlation for circularity (R2=0.48, ρ=-0.32) with FF and pathologist grades, respectively. FHR showed a better distinction between pathologist Fat CRN grades compared to conventional FF measurements, making it a potential surrogate measure for Fat CRN scores. Our results showed variation in distribution of morphological features and steatosis heterogeneity within the same patient's biopsy sample as well as between patients of similar FF. The fat percentage measurements, specific morphological characteristics, and patterns of distribution quantified with the automated segmentation algorithm showed associations with steatosis severity; however, future studies are warranted to evaluate the clinical significance of these steatosis features in progression of NAFLD and NASH.

Distribution optimization method of pixel density by surveillance area

The task of optimizing the parameters of the video camera matrix to reduce the redundancy of the generated video signal is considered. The relevance of the topic is due to the existing redundancy of video signals generated by matrices in different parts of the observation zone and, as a result, excessive loading of signal transmission, storage and processing devices. The problem is solved by achieving a uniform distribution of pixel density over the observation area. The methodology is based on solving the problem programmatically, unlike existing solutions using hardware methods. It is based on the representation of the view area as a set of subsets of the observation task space with its subsequent fragmentation in accordance with the observation tasks being solved which determine the required minimum pixel density in different fragments. To solve the problem, the matrix is segmented in according to the size of the fragments of the observation area and the specified allowable range of changes in the distribution of pixel density in the viewing area of the camera. Mandatory and additional distribution optimization criteria are proposed. The optimization technique is formulated. In according to the redundancy coefficient of the pixel density distribution in different segments, pixels are combined into groups that are different in different segments. Examples of solving optimization problems according to different criteria are given. The proposed approach makes it possible to minimize the pixel density redundancy and thereby reduce the load on communication channels, the amount of memory in video information storage devices, and the performance requirements for video signal processing devices. In this case, the problem of forming a continuous image of the observation zone is also solved. Results could be used for video signal processing and design of new cameras for video surveillance systems.

Impact of Ride-Hailing Services on Transportation Mode Choices: Evidence from Traffic and Transit Ridership

The rise of technology-enabled ride-hailing services has affected individuals’ transportation-related decisions. The impact of these ride-hailing services likely varies across traveler segments that differ in their usage of various modes of transportation. In this paper, we develop and leverage a framework that allows us to examine the impact of ride-hailing services on the transportation mode choice for three traveler segments: drivers (who primarily use a personal automobile to travel), riders (who primarily use public transit to travel), and walkers (who primarily use non-motorized modes of transport). We first develop a framework outlining how the behavior of different traveler segments would be impacted by the introduction of ride-hailing services and show how this affects traffic congestion and public transportation ridership. To test the framework, we compiled a rich dataset, combining data on public transportation ridership, traffic congestion, and individual transportation mode choice. Employing a difference-in-differences methodology, we show that the Uber entry in a market enabled those who were walkers and riders prior to the entry of Uber to travel more conveniently, leading to an increase in traffic congestion, and induced those who were drivers to substitute their use of private automobiles with a combination of Uber and public transit. We introduced urban compactness to assess the heterogeneous impact of ride-hailing services for cities that differ in their distribution of traveler segments. We found that Uber entry increases traffic congestion and reduces public transit demand more in cities with higher levels of urban compactness, i.e., where the proportion of riders and walkers is higher than that of drivers. This work provides a holistic framework to understand the mechanism underlying the impact of ride-hailing services on public transit and traffic congestion. Urban planners and policy makers can leverage our framework, methodology, and empirical results to guide city planning decisions that have implications for sustainability.

Quantifying Output Power and Dynamic Charge Distribution in Sliding Mode Freestanding Triboelectric Nanogenerator

AbstractThe general concept of dielectric polarization density (P) is a macroscopic description of the underlying microscopic structure in the presence of an external electric field and polarized materials itself. A time‐dependent polarization PS induced by a non‐electric field also exists in practice due to the mechanically driven relative motion of media owing to the effects of contact electrification or piezoelectricity. In this work, the starting point is to consider the difference between P and PS, and how PS enters into the governing equations, since it describes the dielectric polarization density without an applied electric field, finally modifying the constitutive relations, Faraday's law, and Maxwell's equations. On this background, a 3D mathematical‐physical model for the sliding mode freestanding triboelectric nanogenerators (TENGs) is established that is taken as an example to confirm the relationship of free charge distribution and dynamics of output power. What needs to be emphasized is that the method of segmented uniform charge distribution is effective and the physical basis for modeling construction and analysis. Finally, we summarized the mathematical‐physical models of TENGs in rectangular coordinates, cylindrical coordinates, and spherical coordinates, building a bridge to reveal the underlying principle behind the microscopic polarization and energy conversion.

Improving Thickness Uniformity of Amorphous Oxide Films Deposited on Large Substrates by Optical Flux Mapping

In this study, three amorphous oxide thin films are prepared by an electron beam evaporation combined with ion-assisted deposition technique. With the aid of optical flux mapping method, thin film thickness distribution with good uniformity can be obtained by appropriate coating masks. Three metal oxide single-layer thin films are SiO2, Ta2O5 and Nb2O5, respectively. These thin films were deposited on a substrate holder with a radius of 275 mm that was divided into five different segments. Based on the optical flux mapping method, we can effectively simulate the geometric dimensions of the coating mask and obtain the width of the coating mask at different segments. If the film thickness uniformity is a function of masking area and center angle, it is necessary to determine the thickness distribution of the different segments and use a surface profiler to accurately measure the film thickness. We analyzed the thickness uniformity of three oxide films deposited at five different segments. The experimental measurement results show that the deviation of thickness uniformity is 0.38% for SiO2, 0.36% for Ta2O5, and 0.15% for Nb2O5 thin films, respectively.

Ecogeomorphic response of a coastal dune in southern Portugal regulated by extrinsic factors

Coastal dunes are complex landforms whose morphology results from various interactions between biotic and abiotic factors. Here, we explore the longshore variability of the morphological features, plant community distribution and accumulation patterns of a dune segment (1.4 km-long) located at the downdrift end of a sandy peninsula in the Ria Formosa, Portugal. To understand the main drivers of the observed variability and the implications for dune morphological response, this information was combined with recent multidecadal shoreline evolution data. The integrated results document significant differences in dune morphology, sedimentation patterns and plant zonation, with two distinct dune configurations or states identified in close proximity. One (western sector) shows a narrower dune system, vegetation cover characterised by pioneer species with low densities, and squeezed plant zonation. Conversely, the other (eastern sector) presents a wider dune system with a new foredune, a more developed plant zonation and relatively high vegetation density. Both states could be partially explained by the recent shoreline trends and inlet shifts, with stable to retreating trends in the western sector and shoreline progradation in the eastern one. Plant zonation and accumulation patterns suggest that the dune along the retreating sector is in a cycle of inland migration, encouraged by the reduced accommodation space and the low retention capacity of the vegetation across the dune stoss. Alternatively, observations along the prograding sector suggest that the greater accommodation space and the stabilising feedback between vegetation and topography promoted the seaward progradation of the system and the development of an incipient foredune. Outcomes support the importance of biogeomorphic feedbacks for the dune configuration, but they also evidence that the role of vegetation within the feedback is primarily regulated by physical factors that ultimately promote or inhibit vegetation effects on dune topography.

Electrophoresis of a soft particle with a hydrophobic rigid core decorated with a soft-step and partially ion-penetrable polymer layer

On the basis of flat-plate formalism, we present an analytical theory for the electrophoresis of soft particles consisting of a hydrophobic inner core decorated with a layer of inhomogeneously distributed polymer segments. Biocolloids or bio-compatible drug delivery vehicles often carry the non-wettable or hydrophobic inner core. In addition, due to electrostatic swelling/shrinking processes, a spatially varying heterogeneity can be seen in the monomer distribution as well as charge properties of the peripheral polyelectrolyte layer (PEL). We adopt the soft-step function to model the chemical and structural anisotropy of the peripheral PEL. In addition, the PEL for the aforementioned bio-systems immersed in aquatic microenvironment often induces dielectric gradient-mediated ion partitioning effect, which in turn leads to the PEL to be partially ion penetrable. Within the Debye–Hückel electrostatic framework, we derive a general expression for electrophoretic mobility of a soft particle considering the combined impacts of hydrophobicity of the inner core, inhomogeneously distributed segment distribution accompanied by chemical heterogeneity and ion partitioning effect. We further derived asymptotic limits of the more generic results detailed here under several electrostatic and hydrodynamic conditions.

Manipulating Transverse Spin Angular Momentum with Symmetrically Modulated Hybridly Polarized Vector Optical Field

Transverse spin angular momentum (SAM) of photon, also known as ‘photonic wheel’, has attracted much attention, owing to its extraordinary properties and broad application prospect. Thus, it is essential to flexibly manipulate the transverse SAM in order to satisfy different needs. In this article, we design and generate a new kind of symmetrically modulated hybridly polarized vector optical field (SM-HP-VOF), and pure transverse SAM can be achieved based on the tightly focused SM-HP-VOF. Through adjusting the parameters of the SM-HP-VOF, the shape, intensity, and symmetry of the transverse SAM can be modulated. Moreover, by adding a segmented vortex phase distribution to the SM-HP-VOF, the transverse SAM becomes more concentrated and stronger, indicating that the orbital angular momentum can be a catalyst in modulating transverse SAM. Such results can provide a new avenue in studying and modulating transverse SAM, which would have potential applications in various areas including chip optical circuitry, optical quantum computing, and optical trapping and manipulation.

Differentiation of lower limb vasculitis from physiological uptake on FDG PET/CT imaging.

To analyze the difference of 2-deoxy-2-[18F]fluoro-D-glucose (18F-FDG) uptake between vasculitis and non-vasculitic patients in PET/CT imaging and the factors related to vascular uptake in non-vasculitic patients. To investigate the feasibility of identifying vasculitis of the lower limb and physiological uptake with delayed imaging. Among 244 patients who underwent PET/CT examination, imaging features of patients with or without vasculitis were retrospectively analyzed. The factors related to FDG uptake in the lower limb vessels of non-vasculitic patients were analyzed. Another 44 patients with suspected systemic vasculitis in PET/CT were prospectively studied to analyze the efficacy of delayed imaging on differentiating vascular uptake in lower limbs. In PET/CT imaging of patients with vasculitis, involvement of trunk vessels showed segmental or diffuse FDG distribution. Lower limb vascular involvement showed reticular uptake accompanied by nodular or patchy changes. In non-vasculitic patients, vascular uptake mainly showed linear uptake in lower limb vessels and there was no significant difference in uptake degree compared with vasculitis patients. Body weight and interval time were the independent influence factors of vascular uptake in lower limbs of non-vasculitic patients. In delayed imaging, lower limb vasculitis all showed reticular uptake and physiological uptake all showed a linear pattern. ROC analysis showed the change rate of SUVmax (≥ 20%) between early and delayed imaging could delineate physiological vascular uptake with a sensitivity of 100% and specificity of 81.0%. When PET/CT is used for the diagnosis and classification of vasculitis, the physiological uptake of lower limb vessels may mislead the diagnosis. PET/CT imaging features or delayed imaging improved diagnostic efficacy.