Average Connectivity Research Articles

Quality control procedures and metrics for resting-state functional MRI.

The monitoring and assessment of data quality is an essential step in the acquisition and analysis of functional MRI (fMRI) data. Ideally data quality monitoring is performed while the data are being acquired and the subject is still in the MRI scanner so that any errors can be caught early and addressed. It is also important to perform data quality assessments at multiple points in the processing pipeline. This is particularly true when analyzing datasets with large numbers of subjects, coming from multiple investigators and/or institutions. These quality control procedures should monitor not only the quality of the original and processed data, but also the accuracy and consistency of acquisition parameters. Between-site differences in acquisition parameters can guide the choice of certain processing steps (e.g., resampling from oblique orientations, spatial smoothing). Various quality control metrics can determine what subjects to exclude from the group analyses, and can also guide additional processing steps that may be necessary. This paper describes a combination of qualitative and quantitative assessments to determine the quality of fMRI data. Processing is performed using the AFNI data analysis package. Qualitative assessments include visual inspection of the structural T1-weighted and fMRI echo-planar images, functional connectivity maps, functional connectivity strength, and temporal signal-to-noise maps concatenated from all subjects into a movie format. Quantitative metrics include the acquisition parameters, statistics about the level of subject motion, temporal signal-to-noise ratio, smoothness of the data, and the average functional connectivity strength. These measures are evaluated at different steps in the processing pipeline to catch gross abnormalities in the data, and to determine deviations in acquisition parameters, the alignment to template space, the level of head motion, and other sources of noise. We also evaluate the effect of different quantitative QC cutoffs, specifically the motion censoring threshold, and the impact of bandpass filtering. These qualitative and quantitative metrics can then provide information about what subjects to exclude and what subjects to examine more closely in the analysis of large datasets.

Temperature Dependence of Hydrogen Bond Networks of Liquid Water: Thermodynamic Properties and Structural Heterogeneity from Topological Descriptors.

Topological analyses of hydrogen bond networks were performed based on the complex network and island statistics of liquid water at different temperatures. The influence of temperature on the liquid water structures and the topological properties of the hydrogen bond networks was investigated by Metropolis Monte Carlo simulations with the TIP4P/2005 potential model. The bilinear behavior of the second peak in the radial distribution function with the temperature was properly reproduced by these simulations. The average connectivity also displayed a bilinear behavior consistent with being a local descriptor. The semiglobal average path length (or geodesic distance) descriptor showed an unprecedented trimodal distribution, whose areas were dependent on the temperature. Considering equilibrium between these three sets of networks, standard enthalpy and entropy of equilibrium were determined for the first time, providing new insights into the structural heterogeneities of liquid water with interesting perspectives for modeling these quantitative properties of hydrogen bond networks.

Characteristics and Influencing Factors of Multi-Scale Pore Structure Heterogeneity of Lacustrine Shale in the Gaoyou Sag, Eastern China

The success of shale oil exploration and production is highly dependent on the heterogeneous nature of the reservoir pore structure. Despite this, there remains limited research on the heterogeneity characteristics of pores at different scales in lacustrine shale oil reservoirs and the factors that impact them. This study aims to quantitatively characterize the multi-scale pore heterogeneity differences of the lacustrine shale found in the Funing Formation in Gaoyou Sag. Additionally, the study seeks to clarify the impact of the total organic carbon (TOC) and lithofacies type on pore structure heterogeneity. To achieve this, nitrogen adsorption, scanning electronic microscope (SEM), mercury intrusion porosimetry (MIP), and other experimental means were adopted in combination with the fractal dimension model of FHH and capillary. The results show that the predominant lithofacies of the Funing Formation shale samples are mixed shale (MS) and siliceous shale (SS), with a limited presence of calcareous shale (CS). The micro-pores of lacustrine shale are dominated by inorganic mineral pores and fewer organic pores. Intragranular pores and clay mineral pores are two types of inorganic mineral pores that are widely found. Small pores (pore diameter < 50 nm) make up 89% of the pore volume (PV) and 99% of the specific surface area (SSA). The fractal dimensions D1, D2, and D3 were calculated to characterize the roughness of the pore surface, the structural complexity of small pores, and the structural complexity of large pores (pore diameter > 50 nm), respectively. The increase in the total organic carbon (TOC) resulted in a decrease in the D1, D2, PV, and SSA, while connectivity showed a slight improvement. The fractal dimension of shale across all lithofacies followed the pattern: D3 > D2 > D1. The pore structure is more complex than the pore surface, and the large pores showed a greater heterogeneity than the small pores. Among the three lithofacies, CS had the largest PV, SSA, D1, and D2, indicating the development of a more complex pore structure network. This expands the space required for shale oil occurrence. However, the connectivity of the CS lithofacies is the lowest among the three, which hinders shale oil production. Although the PV of SS is slightly lower than that of CS, its average pore diameter (AVE PD) and connectivity are significantly advantageous, making SS an ideal shale reservoir. This study provides an important reference for the reservoir evaluation required to better develop lacustrine shale oil around the world.

Spatial distribution characteristics of sediment connectivity and soil erosion in small watershed in brown soil hilly region of low mountains in western Liaoning Province, China.

Understanding the spatial distribution characteristics of soil erosion and sediment connectivity is important for formulating integrated watershed management measures. Based on the InVEST sediment delivery ratio model, we used the connectivity index and soil loss model to measure the spatial distribution characteristics of sediment connectivity and soil erosion in Erdaoling watershed of brown soil hilly region of low mountains in western Liaoning. By exploring slope, aspect and land use characteristics under different sediment connectivity levels and soil erosion levels, we analyzed the relationships among topography, land use, sediment connectivity, and soil erosion. The results showed that the average sediment connectivity in the watershed was -3.79, and that the average soil erosion was 614 t·km2·a-1. High connectivity was mainly found in sloping farmland, while low connectivity was mainly found in forest and grassland. The soil erosion intensity of 93.3% of the watershed area was below moderate, with only 1.1% of the area being above extremely strong. The higher the sediment connectivity level, the higher the proportion of the area <5° slope, while the area proportion of the rest slope was relatively stable. The proportion of cultivated land area increased, while the proportion of forest and grassland land area decreased. The area proportion on negative slope decreased, while that on positive slope increased. With increasing soil erosion intensity, the area proportion of slope <8° increased and the area proportion of the rest slope was relatively stable. The proportion of forest and grassland area decreased, while the proportion of other land use area increased. The proportion of slope area on positive slope increased, while that on negative slope decreased. Land use was a key factor influencing the spatial response relationship between soil erosion and sediment connectivity in this watershed.

CP-MLR/PLS directed quantitative structure-activity relationship study on the histamine H3 receptor binding affinity: The cyclohexylamine based series

The histamine H3 receptor binding affinities of cyclohexylamine derivatives has been analysed with the topological and molecular features from Dragon software. Analysis of the structural features in conjunction with the biological endpoints in combinatorial protocol in multiple linear regression (CP-MLR) led to the identification of 26 descriptors for modelling the activity. The study clearly suggested the role of atomic properties such as mass, electronegativity or charge content, polarizability, atomic van der Waals volume, average valence connectivity index chi-5 and absence of number of acceptor atoms for H-bonds (N, O, F) type functionality to optimise the histamine H3 receptor binding affinity of titled compounds. The models developed and the participating descriptors advocate that the substituent groups of the cylohexylamine moiety hold scope for further modification in the optimization of the H3 receptor binding affinity. Analysis of these descriptors in partial least squares (PLS) highlighted their relative significance in modulating the biological response. The selected descriptors are enriched with information corresponding to the activity when compared to the remaining ones. Applicability domain analysis revealed that the suggested model matches the high quality parameters with good fitting power and the capability of assessing external data and all of the compounds was within the applicability domain of the proposed model and were evaluated correctly.

Structural relaxation in IR transmitting (GeSe4)100-x(As2Se3)x glasses

(GeSe4)100-x (As2Se3)x glasses in the GeSe4-As2Se3 pseudo-binary joint are prepared by the melt quenching method. In this tie-line, the entire composition 0 ≤ x ≤ 100 is characterized by fixed average network connectivity of 2.40, which is considered to be optimal connectivity as the number of constraints and the number degrees of freedom available to the atoms are balanced at this average connectivity. The glass forming ability of the glasses having this average connectivity of 2.40 is usually found to be maximum. Glass transition temperature (Tg) decreases till x = 30 and remains invariant in the range 40 ≤ x ≤ 70. For x > 70, Tg shows an increasing trend. The jump in specific heat capacity (ΔCp), non-reversing heat flow (ΔHnr), Tg and the optical bandgap (Eg) show a distinct change in the composition range 40 and 70 mol.% of As2Se3. The fragility index (m) lies in the range of 15 and 32 for all the prepared glasses, representing the strong nature of these glass forming melts in the (GeSe4)100-x (As2Se3)x glasses. The viscosity as a function of reduced temperature (Tg/T) shows almost an Arrhenius nature for 0 ≤ x ≤ 70 and for x > 70, a slight deviation from the Arrhenius behviour is observed. The structural network of these glasses primarily consists of GeSe4/2 and Se-Se chains for x ≤ 30. For 40 ≤ x ≤ 70, the network is dominated by AsSe3/2 pyramidal units and As-As homopolar bonds. For x > 70, the structural network is characterized by AsSe3/2 pyramidal units. All the prepared glasses are found to transmit infrared (IR) light over a wide wavelength range from 2 to 17 μm. The super strong nature of the melts indicates that optical devices can be easily made for IR applications.

Comparison of Soil Bacterial Communities under Canopies of Pinus tabulaeformis and Populus euramericana in a Reclaimed Waste Dump

To compare the effects of different remediation tree species on soil bacterial communities and provide a theoretical basis for the selection of ecosystem function promotion strategies after vegetation restoration, the characteristic changes in soil bacterial communities after Pinus tabulaeformis and Populus euramericana reclamation were explored using high-throughput sequencing and molecular ecological network methods. The results showed that: (1) With the increase in reclamation years, the reclaimed soil properties were close to the control group, and the soil properties of Pinus tabulaeformis were closer to the control group than those of P. euramericana. (2) The dominant bacteria under the canopies of P. tabulaeformis and P. euramericana was the same. Proteobacteria, Actinobacteria, Acidobacteria, Chloroflexi, Gemmatimonadetes, Planctomycetes, Bacteroidetes, and Cyanobacteria were the dominant bacteria in the restored soil, accounting for more than 95% of the total abundance. The average values of the Shannon diversity index, Simpson diversity index, Chao 1 richness estimator, and abundance-based coverage estimator of the bacterial community in the P. euramericana reclaimed soil were higher than those in the P. tabulaeformis reclaimed soil. The influence of reclamation years on the bacterial community of samples is greater than that of species types. (3) The results of ecological network construction showed that the total number of nodes, total number of connections, and average connectivity of the soil bacterial network under P. euramericana reclamation were greater than those under P. tabulaeformis reclamation. The bacterial molecular ecological network under P. euramericana was more abundant. (4) Among the dominant bacteria, the relative abundance of Actinobacteria was negatively correlated with soil pH, soil total nitrogen content, and the activities of urease, invertase, and alkaline phosphatase, while the relative abundance of Proteobacteria and Bacteroidetes was positively correlated with these environmental factors. The relationship between the soil bacterial community of P. tabulaeformis and P. euramericana and the environmental factors is not completely the same, and even the interaction between some environmental factors and bacteria is opposite.

A differential game approach for real-time security defense decision in scale-free networks

The current network security defense decision method is based on the principle of attack–defense confrontation and generally uses a random network model to project the real network. Most of the existing complex network defense decision methods consider a single defender while ignoring the confrontation and dependence between network attack and defense behaviors. In addition, the pertinence and dynamics of the defense effect are also insufficient. This article comprehensively considers the structure of a scale-free network and characteristics of network attack and defense behavior and combines a complex network with differential game theory to study the real-time defense decision problem. First, a propagation model based on a scale-free network is designed to realize the real-time fluctuation analysis of a network security state. Then, the attack and defense strategy are described, and the calculation method of revenue based on the confrontation analysis of the attack and defense behavior and a change in the security state of the network nodes based on the saddle point equilibrium strategy are introduced. Finally, based on the average connection degree of the real word Internet, a simulated network is constructed to conduct experiments. By comparison with random defense strategies and several typical complex network defense decision methods, the effectiveness and advancement of the proposed method are verified.

Blume–Emery–Griffiths model on random graphs

The Blume–Emery–Griffiths model with a random crystal field is studied in a random graph architecture, in which the average connectivity is a controllable parameter. The disordered average over the graph realizations is treated by replica symmetry formalism of order parameter functions. A self consistent equation for the distribution of local fields is derived, and numerically solved by a population dynamics algorithm. The results show that the average connectivity amounts to changes in the topology of the phase diagrams. Phase diagrams for representative values of the model parameters are compared with those obtained for fully connected mean field and renormalization group approaches.

The Importance of Laminae for China Lacustrine Shale Oil Enrichment: A Review

The laminar structure of shale system has an important influence on the evaluation of hydrocarbon source rock quality, reservoir quality, and engineering quality, and it is receiving increasing attention. A systematic study of the lamina structure is not only of great scientific significance but also of vital practical importance for shale oil production. In this paper, the identification and description classification of shale laminae are first reviewed. Multiple scales and types indicate that a combination of different probe techniques is the basis for an accurate evaluation of shale laminar characteristics. The influence of laminae on shale reservoir, oil-bearing, mobility, and fracability properties is discussed systematically. A comparative analysis shows that shale systems with well-developed lamination facilitate the development of bedding fractures, thus improving the shale storage space. The average pore size and pore connectivity are also enhanced. These factors synergistically control the superior retention and flow capacity of shale oil in laminated shales. In such conditions, the high production of shale oil wells can still be achieved even if complex networks of fracturing cracks are difficult to form in shale systems with well-developed lamination. This work is helpful to reveal the enrichment mechanism of shale oil and clarify the high-yield law of hydrocarbons, so as to guide the selection of sweet spots.

Parallel Factorization to Implement Group Analysis in Brain Networks Estimation.

When dealing with complex functional brain networks, group analysis still represents an open issue. In this paper, we investigated the potential of an innovative approach based on PARAllel FActorization (PARAFAC) for the extraction of the grand average connectivity matrices from both simulated and real datasets. The PARAFAC approach was solved using three different numbers of rank-one tensors (PAR-FACT). Synthetic data were parametrized according to different levels of three parameters: network dimension (NODES), number of observations (SAMPLE-SIZE), and noise (SWAP-CON) in order to investigate the way they affect the grand average estimation. PARAFAC was then tested on a real connectivity dataset, derived from EEG data of 17 healthy subjects performing wrist extension with left and right hand separately. Findings on both synthetic and real data revealed the potential of the PARAFAC algorithm as a useful tool for grand average extraction. As expected, the best performances in terms of FPR, FNR, and AUC were achieved for great values of sample size and low noise level. A crucial role has been revealed for the PAR-FACT parameter, revealing that an increase in the number of rank-one tensors solving the PARAFAC problem leads to an increase in FPR values and, thus, to a worse grand average estimation.

Age Related Functional Connectivity Signature Extraction Using Energy-Based Machine Learning Techniques.

The study of brain connectivity plays an important role in understanding the functional organizations of the brain. It also helps to identify connectivity signatures that can be used for evaluating neural disorders and monitoring treatment efficacy. In this work, age-related changes in brain connectivity are studied to obtain aging signatures based on various modeling techniques. These include an energy-based machine learning technique to identify brain network interaction differences between two age groups with a large (30 years) age gap between them. Disconnectivity graphs and activation maps of the seven prominent resting-state networks (RSN) were obtained from functional MRI data of old and young adult subjects. Two-sample t-tests were performed on the local minimums with Bonferroni correction to control the family-wise error rate. These local minimums are connectivity states showing not only which brain regions but also how strong they are working together. They work as aging signatures that can be used to differentiate young and old groups. We found that the attention network's connectivity signature is a state with all the regions working together and young subjects have a stronger average connectivity among these regions. We have also found a common pattern between young and old subjects where the left and right brain regions of the frontal network are sometimes working separately instead of together. In summary, in this work, we combined machine learning and statistical approaches to extract connectivity signatures, which can be utilized to distinguish aging brains and monitor possible treatment efficacy.

Opinion Dynamics Systems on Barabási–Albert Networks: Biswas–Chatterjee–Sen Model

A discrete version of opinion dynamics systems, based on the Biswas-Chatterjee-Sen (BChS) model, has been studied on Barabási-Albert networks (BANs). In this model, depending on a pre-defined noise parameter, the mutual affinities can assign either positive or negative values. By employing extensive computer simulations with Monte Carlo algorithms, allied with finite-size scaling hypothesis, second-order phase transitions have been observed. The corresponding critical noise and the usual ratios of the critical exponents have been computed, in the thermodynamic limit, as a function of the average connectivity. The effective dimension of the system, defined through a hyper-scaling relation, is close to one, and it turns out to be connectivity-independent. The results also indicate that the discrete BChS model has a similar behavior on directed Barabási-Albert networks (DBANs), as well as on Erdös-Rènyi random graphs (ERRGs) and directed ERRGs random graphs (DERRGs). However, unlike the model on ERRGs and DERRGs, which has the same critical behavior for the average connectivity going to infinity, the model on BANs is in a different universality class to its DBANs counterpart in the whole range of the studied connectivities.

MORPHOMETRIC FEATURES OF EYE STRUCTURES ACCORDING TO OCT AND CHANGES IN HEMODYNAMICS IN PATIENTS WITH ANTERIOR UVEITIS COMPLICATED BY OPTIC NEURITIS

Aim. Identify changes in the optic disc and vascular membrane by OCT, as well as features of hemodynamics and the possibility of communication between these parameters. Materials and methods. In 150 patients with idiopathic monolateral anterior uveitis, ophthalmic (visometry, refractometry, tonometry, perimetry, biomicroscopy, direct, reverse ophthalmoscopy), examination, rheophthalmography (ROG) and optical coherence tomography (OCT) of structures were performed. Patients received treatment according to the protocol, including, if necessary, antibacterial, antiviral, steroidal and nonsteroidal anti-inflammatory, immunosuppressive, desensitizing, vasodilating, immunomodulatory drugs. Statistical analysis was performed using Statistica 10.0 using Student's coefficient, pairwise correlation and Spearman's rank correlation Research results. The OCT results of the eyes of patients with optic neuritis on the background of anterior uveitis showed a significant increase in the thickness of the layer of peripapillary nerve fibers and vascular membrane by 34.3 and 38.9% relative to the data in anterior uveitis without complications. ROG revealed a significant increase in the tone of small and large vessels of the eye in neuritis on the background of anterior uveitis by 14.2 and 17.2% compared to those without neuritis. There was a direct significant strong relationship between the thickness of peripapillary fibers and the thickness of the vascular membrane with volumetric pulse blood filling, the volume of volumetric blood filling, tonic properties of large and small vessels (r = 0,699-0,909); average - between the diameter of the optic nerve at the entrance to the orbit and the parameters of the ROG (r = 0,647-0,797); weak - determined in the retrobulbar and middle department (r = 0.241-0.453). The development of neuritis in uveitis is accompanied by an increase in the thickness of the peripapillary fibers and vascular membrane, the diameter of the optic nerve at the entrance to the orbit, in the retrobulbar and middle department, as well as volumetric pulse blood filling, volumetric connection in all cases (Spearman r 0.421-0.754). Conclusions 1. The results of OCT of the eyes with optic neuritis on the background of anterior uveitis showed a significant increase in the thickness of the layer of peripapillary nerve fibers and vascular membrane relative to the data in persons with anterior uveitis without complications. 2. The horn of the tonic properties of the vessels revealed a significant increase in the tone of small and large vessels of the eye with optic neuritis on the background of anterior uveitis relative to those without neuritis. 3. The direct strong reliable correlation of indicators of thickness of peripheral fibers and a vascular cover with volume pulse blood filling, speed of volume blood filling, tonic properties of large and small vessels is revealed. Average connection - between the diameter of the optic nerve at the entrance to the orbit and the parameters of the ROG, weak connection with the diameter of the optic nerve in the retrobulbar and middle department. 4. The development of optic neuritis against the background of anterior uveitis is accompanied by an increase in the thickness of the peripheral fibers and choroid, the diameter of the optic nerve at the entrance to the orbit, in the retrobulbar and middle section. The tonic properties of large and small vessels, volumetric pulse blood filling, and the speed of volumetric blood filling, as indicated by the presence of a significant direct correlation. Key words: chronic anterior idiopathic uveitis, optic neuritis, OCT, eye hemodynamics.

Reproducibility of regional structural and functional MRI networks in cerebral small vessel disease compared to age matched and stroke-free controls.

Abnormalities in structural and functional MRI connectivity measures have been reported in cerebral small vessel disease (SVD). Previous research has shown that whole-brain structural connectivity was highly reproducible in SVD patients, while whole-brain functional connectivity showed low reproducibility. It remains unclear whether the lower reproducibility of functional networks reported in SVD is due to selective disruption of reproducibility in specific networks or is generalised in patients with SVD. In this case-control study 15 SVD and 10 age-matched control participants were imaged twice with diffusion tensor imaging and resting state fMRI. Structural and functional connectivity matrices were constructed from this data and the default mode, fronto-parietal, limbic, salience, somatomotor and visual networks were extracted and the average connectivity between connections calculated and used to determine their reproducibility. Regional structural networks were more reproducible than functional networks, all structural networks showed ICC values ≥0.64 (except the salience network in SVD). The functional networks showed greater reproducibility in the controls compared to SVD with ICC values >0.7 for control participants and <=0.5 for the SVD group. The default mode network showed the greatest reproducibility for both control and SVD groups. Reproducibility of functional networks was affected by disease status with lower reproducibility in SVD compared with controls.

A comparative analysis of the robustness of multimodal comprehensive transportation network considering mode transfer: A case study

&lt;abstract&gt; &lt;p&gt;China has built a nationwide transportation network, but there needs to be a smooth connection and transfer between different modes. Five networks are constructed to explore the characteristics of a multimodal comprehensive transportation network (CNet) in Jiangsu Province based on the optimized modeling method and multisource data. Statistical and robustness characteristics are analyzed for CNet and other single-mode networks including the highway, railway, navigation channel and airway networks (HNet, RNet, NNet and ANet, respectively). The research results show following: (ⅰ) In Jiangsu, CNet, HNet, RNet and NNet are not scale-free networks and do not have small-world properties. However, ANet is the opposite. (ⅱ) The five networks in Jiangsu are robust to the random attack and their robustness changes during the attack. However, their robustness is different under different calculated attacks. For all attack strategies, CNet is the most robust. (ⅲ) In Jiangsu, the three optimized methods enhance the robustness significantly. The network failure is delayed by 12.34, 2.79 and 2.44%, respectively. The average connectivity degree is improved by 265.69, 52.95 and 32.54%, respectively. The more hubs there are with powerful transfer capacity, the stronger the network robustness. The results reveal the key points of the construction of a multimodal comprehensive transportation system and can guide the design and optimization of it.&lt;/p&gt; &lt;/abstract&gt;

Analysis Analysis Analysis of Virtual Reality-Based Warehouse Simulation Applications Using The Game User Experience Satisfaction Scale Method

In the world of simulation, there are many issues related to how to make a simulation interesting and make users want to use it again. One of them is user satisfaction. User satisfaction is the extent to which players feel satisfied when using an application. The warehouse simulation application is an application that is based on three dimensions and can only be run using virtual reality technology. This application aims to simulate how the activities of a picker in the warehouse. This research was conducted to determine the level of user satisfaction when using the warehouse simulation application. The research was conducted using the Game User Experience Satisfaction Scale (GUESS) method which has nine subscales, namely usability, narratives, play engrossment, enjoyment, creative freedom, audio aesthetics, personal gratification, social connectivity, and visual aesthetics. Data collection was carried out by distributing questionnaires through online media. Respondents in this study were 30 students of the Batam State Polytechnic International Trade Logistics study program. The analysis method uses a descriptive quantitative method. The results of the analysis show that of the nine subscales of user satisfaction with the Warehouse simulation application, four subscales are below average, namely enjoyment, audio aesthetics, personal gratification, and social connectivity. From these results, what needs to be improved is the addition of audio and UI that gives appreciation to users to increase personal gratification, changing the color concept in each scene so that users do not feel bored with the application.

Inversion tillage with straw incorporation affects the patterns of soil microbial co-occurrence and multi-nutrient cycling in a Hapli-Udic Cambisol

Inversion tillage with straw amendment is widely applied in northeastern China, and it can substantially increase the storage of carbon and improve multiple subsoil functions. Soil microorganisms are believed to be the key to this process, but research into their role in subsoil amelioration is limited. Therefore, a field experiment was conducted in 2018 in a region in northeastern China with Hapli-Udic Cambisol using four treatments: conventional tillage (CT, tillage to a depth of 15 cm with no straw incorporation), straw incorporation with conventional tillage (SCT, tillage to a depth of 15 cm), inversion tillage (IT, tillage to a depth of 35 cm) and straw incorporation with inversion tillage (SIT, tillage to a depth of 35 cm). The soils were managed by inversion to a depth of 15 or 35 cm every year after harvest. The results indicated that SIT improved soil multi-nutrient cycling variables and increased the availability of key nutrients such as soil organic carbon, total nitrogen, available nitrogen, available phosphorus and available potassium in both the topsoil and subsoil. In contrast to CT and SCT, SIT created a looser microbial network structure but with highly centralized clusters by reducing the topological properties of average connectivity and node number, and by increasing the average path length and the modularity. A Random Forest analysis found that the average path length and the clustering coefficient were the main determinants of soil multi-nutrient cycling. These findings suggested that SIT can be an effective option for improving soil multi-nutrient cycling and the structure of microbial networks, and they provide crucial information about the microbial strategies that drive the decomposition of straw in Hapli-Udic Cambisol.

Connectivity indices of m-polar fuzzy network model, with an application to a product manufacturing problem

Connectivity is among the most essential concerns in graph theory and its applications. We consider this issue in a framework that stems from the combination of m-polar fuzzy set theory with graphs. We introduce two measurements of connectedness of m-polar fuzzy graphs that we call their connectivity and average connectivity indices. Examples are given, and the theoretical performance of these concepts is investigated. Particularly, we are concerned with the effect of deleting a vertex or an edge from an m-polar fuzzy graph, on its connectivity and average connectivity indices. We also establish bounding expressions for the connectivity index in complete m-polar fuzzy graphs, complete bipartite m-polar fuzzy graphs, and wheel m-polar fuzzy graphs. Moreover, we introduce some special types of vertices called m-polar fuzzy connectivity reducing vertices, m-polar fuzzy connectivity enhancing vertices, and m-polar fuzzy connectivity neutral vertices. Our theoretical contribution is applied to a product manufacturing problem that takes advantage of multi-polar uncertain information. The justification for our application is systematized using an algorithm. Finally, we compare the proposed method to existing methodologies to demonstrate its feasibility and applicability.

KEKUATAN SAMBUNGAN DUA TAMPANG PADA MDF DENGAN ALAT SAMBUNG PASAK WPC

MDF (Medium Density Fiberboard) and WPC (Wood Plastic Composite) are innovative results of using sawdust waste to overcome the problem of wood scarcity. This study used a WPC Teak dowel because it has high shear strength and does not cause rust marks. This study was conducted to determine the value of the MDF connection capacity using WPC Teak dowel connectors and to determine the connection failure mode based on the EYM (European Yield Model) theory. This study used a WPC Teak dowel with a diameter of 6 mm, 8 mm, 10 mm, and 12 mm. The type of connection is a double-shear wooden joint using MDF. The test was carried out at the Structural Laboratory, Civil Engineering Department, Tidar University using a Compression Testing Machine to get the value of the connection capacity and test failure mode based on the MDF bearing strength and WPC Teak post failure referring to ASTM D764-97a. The test results obtained an average connection capacity value WPC dowel with a diameter of 6 mm, 8 mm, 10 mm, and 12 mm, respectively, which was 1094 N; 1870 N; 2439 N; and 3462. The highest average connection capacity value at 12 mm diameter was 3462 N, and the lowest at 6 mm was 1094 N.