Connection Length Research Articles

Atypical brain network development of infants at elevated likelihood for autism spectrum disorder during the first year of life.

Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by behavioral features that appear early in life. Although studies have shown that atypical brain functional and structural connectivity are associated with these behavioral traits, the occurrence and initial alterations of brain networks have not been fully investigated. The current study aimed to map early brain network efficiency and information transferring in infants at elevated likelihood (EL) compared to infants at typical likelihood (TL) for ASD in the first year of life. This study used a resting-state functional near-infrared spectroscopy (fNIRS) approach to obtain the length and strength of functional connections in the frontal and temporal areas in 45 5-month-old and 38 10-month-old infants. Modular organization and small-world properties were detected in both EL and TL infants at 5 and 10months. In 5-month-old EL infants, local and nodal efficiency were significantly greater than age-matched TL infants, indicating overgrown local connections. Furthermore, we used a support vector machine (SVM) model to classify infants with or without EL based on the obtained global properties of the network, achieving an accuracy of 77.6%. These results suggest that infants with EL for ASD exhibit inefficiencies in the organization of brain networks during the first year of life.

First snowflake divertor experiments in MAST-U tokamak

First snowflake (SF) divertor experiments in the MAST-U tokamak demonstrated steady-state snowflake-plus divertor configurations in 450 kA ohmic L-mode plasmas. The SF divertor configuration features a second poloidal field (PF) null in the divertor region close by or overlapping with the main X-point. The resulting low PF region and two additional divertor legs (strike points) may lead to additional power and particle flux sharing via a hypothesized convective cell, and increased plasma-wetted area and radiation. The free-boundary Grad–Shafranov equilibrium code FIESTA was used to design SF configurations with several inter-null distances and orientations. In the experiment, the SF configurations with inter-null distances 0.13–0.20 m and lasting 0.2–0.3 s were obtained. Parallel connection lengths between the midplane and the outer strike point in the SF configurations (evaluated at field lines 1–2 mm from the separatrix in the midplane) were 25–30 m, higher than in the standard divertor (20–25 m) or the Super-X divertor (25 m). Diagnostic measurements highlighted salient SF features. The infra-red video bolometer diagnostic showed that the radiated power peaking in the PF null region was not as pronounces as in the standard divertor. Divertor ion fluxes measured by target Langmuir probes showed increased ion flux in the plate region where a secondary SF strike point landed, concomitantly with the SF formation. These measurements may suggest that some particle and heat redistribution was taking place in the convective SF zone. The first SF experiments provide a basis for future SF studies in MAST-U tokamak with higher input power, improved plasma control and diagnostic measurements, to be compared with the modeling predictions of plasma convective SF mixing and lower density strike point detachment threshold. • First snowflake (SF) divertor experiments in the MAST-U tokamak demonstrated steady-state snowflake-plus divertor configurations with inter-null distances 0.13–0.20 m in 450 kA ohmic L-mode plasmas. • The free-boundary Grad–Shafranov equilibrium code FIESTA was used to design SF configurations with several inter-null distances and orientations. • Divertor geometry (i.e., parallel connection lengths, divertor flux expansion and area expansion) in the SF-plus divertor fvorably comared to the standard divertor • Divertor measurements with the infra-red video bolometer diagnostic and target Langmuir probes may suggest that some particle and heat redistribution took place in the convective SF zone.

Deformation mechanism of Ni(O)–yttria-stabilized zirconia upon reduction and its effect on cell stress evolution in solid oxide fuel cells

Deformation of anodes upon reduction causes a cell stress evolution, possibly resulting in cell failure. We studied the effects of compositions on anode deformation and the mechanisms by monitoring anode dimensions and constructing three-dimensional structures. A new evaluation index, “the path length of particles connections (PLPC)", was defined to characterize the microstructure of the anodes, and a YSZ–Ni content diagram was constructed to clarify the relationship between deformation behavior and microstructure. The microstructure exerts significant effects on the deformation, and the deformation mechanisms are classified into four categories based on the PLPC results. The characteristic deformation behavior is discussed for each categories. The stress evolutions of the cell electrolyte upon reduction were examined by FEM analysis incorporating the anode deformation and creep behavior. The numerical analysis demonstrates that the larger the anode deformation, the higher the cell stress generated upon reduction, and the anode deformation may have an impact on mechanical reliability of cells. These results indicate that the cell stress change during reduction may be due to anode deformation and be prevented by selecting optimal anode composition. The YSZ–Ni content diagram is expected to provide fundamental and useful knowledge for designing optimal microstructure in anodes of SOFCs.

Precise path computation based on functional block-based disaggregation for future heterogeneous access-metro networks

Emerging 5G/6G mobile services are intended to cover a broad range of use cases, including applications requiring high bandwidth, low latency, and/or high reliability. To meet these diverse requirements, various optical network technologies and architectures, including optical node structures, transmission technologies, and virtualization technologies, have been extensively investigated. These novel technologies will be integrated to form a platform of future optical access-metro networks that support various mobile services. Such an optical access-metro platform will comprise heterogeneous node structures based on various optical functional blocks (e.g., wavelength selective switches, optical splitters, or arrayed waveguide gratings). To realize a versatile optical access-metro platform, a network resource management system that can universally handle heterogeneous node structures is indispensable. This study investigates the applicability of a functional block-based disaggregation (FBD) approach to such a resource-management system. Here, the previously proposed FBD model is extended to incorporate latency aware path computation. The results demonstrated that the FBD model could be successfully used with heterogeneous network structures, including both passive and switchable optical nodes. The precise path computation capability of the model was also demonstrated, and the scalability of the computation time was quantitatively evaluated in a parallel processing environment. Precise path computation can effectively consider both intra- and inter-node fiber connection lengths, which are useful for handling latency requirements based on an accurate representation of the propagation delay.

Multidimensional interaction of L2 writing fluency and cohesion: A complexity theory perspective

Applying a view of L2 writing development from the perspective of complexity theory, this study explores the multidimensionality of L2 writing fluency and cohesion, examines the interaction of their internal dimensions and confirms four types of writing fluency and cohesion development patterns. 14 tasks in one academic year producing 910 essays by 65 learners from southern Africa were collected as the corpus. Factor analysis is used to investigate L2 writing fluency and the cohesion dimension. Non-parametric correlation analysis, LOESS curve and change point analysis are conducted to analyse the multidimensional interactive patterns. Results show the following: 1) L2 writing fluency and cohesion involve five indicators in the three subdimensions of referential cohesion, connective and unit length; 2) the development of writing fluency weakly supports the cohesion development of noun overlap and connective indices, but weakly competes against the development of latent semantics. Dimensions of conjunction and lexical word overlap develop mutually in coordination; and 3) four interaction patterns of L2 writing fluency and cohesion were identified, namely an unstable type, a coordinative type, a competitive type and a coordinative- competitive type. These findings show significant differences in individual and group statistical features, which expand the scope of interpretation of the complexity theory.

Microstructure and damage evolution of hydraulic concrete exposed to freeze–thaw cycles

In cold regions, hydraulic concrete structures are vulnerable to freeze–thaw (FT) damage, which is manifested by the evolution of microstructure in concrete. In order to reveal this evolution law, the rapid FT test is carried out on hydraulic concrete, and the damage evolution of hydraulic concrete under FT action is studied by using the combination of X-ray computed tomography (X-ray CT) technology and deep convolutional neural network (U-Net) image segmentation method. The results show that the U-Net image segmentation has higher accuracy than traditional threshold segmentation, and can capture microcracks and capillary pores caused by FT damage. The pores and cracks developed due to the FT cycles connect the isolated primary pores with each other, resulting in a significant increase in the connectivity and skeleton length of the internal pore structure of hydraulic concrete. In addition, the FT damage increases the number of pores and microcracks in interfacial transition zone (ITZ), and even degums aggregates from their surrounding mortar matrix, resulting in a continuous increase in the surface area of pores and microcracks in ITZ. Considering the FT damage of hydraulic concrete as a kind of fatigue effect, a FT damage evolution model based on continuous damage mechanics (CDM) is established, and the effectiveness of the model in predicting FT damage of hydraulic concrete is verified by comparing with the experimental results.

Generation of Single Sideband-Suppressed carrier (SSB-SC) Signal Based on Stimulated Brillouin Scattering

A novel cost-effective wavelength shifter is suggested in this paper. This paper shows how to shift signals in the mm-wave area using a frequency shifter. Due to stimulated Brillouin scattering in optical fibre, the proposed approach produces a single sideband signal without the carrier signal. When compared to SSB-SC transmissions, the bandwidth efficiency of double sideband signals is lower. Because it employs an optical fibre with a performance degrading condition such as SBS as an application, the frequency shifter is entirely optical. The theory of Gain and Loss Spectrum of SBS within optical fibre is utilised to minimise the upshifted frequency component and boost the low shifter frequency component in order to generate improved carrier power and single sideband. The SBS phenomenon produces a single sideband, which is advantageous in advanced modulation systems and consumes less bandwidth. It’s worth noting that the SSB-SC signal may be generated using any optical approach, and the proposed work eliminates the need for non-optical components like 90-degree hybrid couplers. SSB-SC signals are capable of combating pulse broadening difficulties and have the ability to operate at terahertz frequencies. Transmission of an SSB-SC signal is also shown to validate the performance of the produced signal. Furthermore, the Q factor of SSB-SC, SSB with carrier, DSB-SC, and DSB with carrier signals is studied at various connection lengths.

Effect of magnetic geometry on the energy partition between ions and electrons in the scrape-off layer of magnetic fusion devices

A universal energy partition mechanism between ions and electrons has been confirmed to exist in the scrape-off layer of both the WEST tokamak and the W7-X stellarator. A peaked plasma density structure induced by an infinite magnetic connection length structure is observed to destroy this dependence and enhance the local ion and electron temperature ratio in the stellarator. A theoretical analysis reveals that the ratio of ion and electron parallel heat conduction is predominant in determining this universality, while electrons would further be cooled in the density-peaked region.

Analysis of higher education management strategy based on entropy and dissipative structure theory

Abstract In order to explore the analysis of educational management strategies in Colleges and universities, a method based on entropy and dissipative structure theory is proposed. Firstly, we determine the connection length B, which refers to the shortest path between two elements in the structure diagram. The length of direct connection is 1, and the length of each transfer is added by 1. Secondly, calculate the total number of microscopic states of the system, A 1, A 1 = ∑∑ Lab, Third, calculate the probability value of the realization of the micro state of each connection: P ( a , b ) = L a b A a P\left( {a,b} \right) = {{{L_{ab}}} \over {{A_a}}} . Finally, the entropy of organizational structure between any two elements of the system at the same level vertically and horizontally is calculated: H 1(ab) = −Pa (ab)lnPa (ab). The experimental results show that student satisfaction is considered to be an important dimension of management team performance evaluation. Through the survey of student satisfaction, it is found that the student satisfaction rate of two teams is 100%, the student satisfaction rate of two teams is 99%, and the satisfaction rate of one team is 98.5%, which shows that the management team has good performance. It is proved that the theory of entropy and dissipative structure can effectively improve the educational management strategy of colleges and universities.

Experimental and numerical study on reduction coefficient of the shear capacity of austenitic long stainless-steel bolted connections

Stainless-steel has better ductility than carbon steel, and the stress redistribution phenomenon is more obvious in the austenitic long stainless-steel bolted connections. In this paper, reduction coefficient of the shear capacity of austenitic long stainless-steel bolted connections was investigated. A total of 15 specimens of austenitic long stainless-steel bolted connections were studied in the experiment. A finite element (FE) analysis was performed for studying the reduction coefficient, and it was verified through the comparison of the experimental results. Then the key variables affecting the reduction coefficient of long connections were studied through a parametric analysis. It was found that connection length, the value of An/As (ratio of net section area of connecting sheet An to total shear area of bolt rod As) were the most important variables affecting the reduction coefficient. When the connection length was in the range of 15 d0-64 d0, the reduction coefficient decreased linearly with the increase of connection length. When the connection length was fixed, the reduction coefficient increased with the value of An/As. This was because the greater value of An/As, the smaller the deformation at the bolt hole under the same load, which reduced the degree of inhomogeneity of bolt shear distribution and the less the shear capacity. Finally, the suggested formula of reduction coefficient of the shear capacity of austenitic long stainless-steel bolted connections was put forward.

Optimizing detachment control using the magnetic configuration of divertors

As tokamak research moves to reactor conditions, the control of a stable, optimally-detached divertor plasma has become increasingly relevant. Simple predictions of such detachment control have been performed previously using the detachment location sensitivity (DLS) model (Lipschultz et al 2016 Nucl. Fusion 56 056007). In this study the DLS model is extended and combined with SOLPS-ITER simulations of isolated divertor grids to study the effects of alternate divertor magnetic field properties on detachment control. The DLS model predicts that divertors can achieve easier access to detachment through a long connection length, a high total flux expansion, and a high average magnetic field in the divertor compared with that at the x-point. SOLPS-ITER simulations suggest an even stronger impact of total flux expansion and connection length on detachment access than the DLS model predicts. In terms of detachment evolution, both simulation and modelling show a high gradient in the total magnetic field and low are able to more easily keep a detachment front at a desired poloidal location. Regions with no stable detachment front locations can arise for high magnetic field gradients directed towards the target. Significant differences have been found between impurity scan simulations and the DLS model. These differences may be attributed to sources and sinks of power and electron pressure, and should be explored further in future work.

The 3D magnetic topology and plasma dynamics in open stochastic magnetic field lines

The thermal quench triggered by locked modes is known to be mainly due to open stochastic magnetic field lines connected to the wall boundary. It is essential to understand the 3D structure of open stochastic field lines since it determines the overall plasma dynamics in the system. In this study, we analyze the 3D magnetic topology for two key concepts, the connection length Lc and the effective magnetic mirror ratio Meff, and present a comprehensive picture of electron and ion dynamics related to the magnetic topology. The connection length determines the 3D structure of the ambipolar potential, and a sharp potential drop across distinct Lc regions induces the E × B transport and mixing across the field line. The confinement of electrons and ions along the field line is determined by the ambipolar potential and Meff configuration. Electron and ion temperatures in magnetic hills (Meff<1) are lower than in magnetic wells (Meff>1) because particles in magnetic hills are more likely to escape toward the wall boundary along the field line. The mixing between the magnetic wells and hills by E × B and magnetic drift motions results in collisionless detrapping of electrons and ions, which reduces their temperature efficiently. Numerical simulations of two different magnetic configurations demonstrate the importance of the collisionless detrapping mechanism, which could be the main cause of plasma temperature drop during the thermal quench.

Axial Compression and Buckling Analysis of Columnar Structures with Tetra-Anti-Chiral Configuration

Abstract The present work is focused on the investigation of tetra-anti-chiral structures by means of numerical and analytical methods. Specimens were evaluated under compressive load using analytical and numerical methods. The paper summarizes a theoretical solution for the estimate of Poisson’s ratio and the plateau force. The models can handle structures with various configurations, such as the radius of the connection node, lengths, and thickness of the ligaments. A section dedicated to the evaluation of the buckling load is included to extend the investigation of the behavior under compressive loads. The theoretical model is based on Euler’s formula, and a series of amendments are performed to adapt the formula to the analysis of chiral structures. Throughout the paper, theoretical results are compared with results from the simulations to validate the principles stated. Two sets of numerical models were developed: a fully 3D model using hexahedral finite elements and a 2.5D model using a beam finite element model. An overall comparison of results is presented, showing a good agreement between datasets. The present work might set the background for future activities, allowing for a selection of individual investigation methods.

Testing, numerical modelling and design of S690 high strength steel channel-to-plate connections

This paper describes experimental and numerical studies of S690 high strength steel channel-to-plate connections failing by net section fracture. Experiments were conducted on 27 S690 high strength steel channel-to-plate connection specimens, with each consisting of a channel section member bolted to two gusset plates by web or flange. The test ultimate loads, load–elongation curves, failure modes and strain distribution at critical cross-sections were fully reported and analysed. The influences of the number of bolt holes, longitudinal pitch, connection length and out-of-plane eccentricity on net section efficiency were discussed. The experimental programme was followed by a numerical modelling programme, where finite element models were firstly developed and validated against the test results and then used to conduct parametric studies to generate further numerical data. Based on the test and numerical data, the accuracy of the relevant design rules, as set out in the European code, American specification and Australian standard, was assessed. The assessment results revealed that the European code leads to overly conservative and scattered ultimate load predictions, while the American specification and Australian standard result in unsafe and scattered ultimate load predictions. Finally, a new design approach was proposed and shown to provide substantially improved ultimate load predictions for S690 high strength steel channel-to-plate connections over the design codes. The reliability of the new design approach was also demonstrated by means of statistical analyses.

Identifying corridors of river recovery in coastal NSW Australia, for use in river management decision support and prioritisation systems.

By connecting corridors of river recovery, resilience can be built into river systems to mitigate against future floods and droughts driven by anthropogenic disturbance or climate extremes. However, identifying where these corridors can be built is still lacking in river management practice. The Open Access NSW River Styles database contains comprehensive information on geomorphic river condition and recovery potential. The database can be used to systematically analyse where corridors of river recovery could be created via conservation or rehabilitation. Analysis was undertaken in ArcGIS using the recovery potential layer along 84,342 km of freshwater stream length, across 20 catchments of coastal NSW. We identified 4,905 km of reach connections, defined as an upstream to downstream section of river that is connected end-to-end, and 17,429 km of loci connections defined as more isolated sections of river from which recovery can be seeded and extended into adjacent reaches. There was significant spatial variability in the types and lengths of connections made across the catchments. Some catchments have significant potential to build corridors of recovery along large sections of river, whereas other catchments are more fragmented. These results provide practitioners with a user-friendly distillation of where river conservation and rehabilitation activities could be focussed when working with river recovery in practice. Combined with local on-ground knowledge, this information forms an important input to evidence-based prioritisation and decision making in river management.

Confirmation of the Absence of Contact Between Edge Boundary Plasma and Inboard First Wall in LHD Discharges Based on Radial Profile Measurement of Hβ Line Emissions

In the Large Helical Device (LHD), a high-performance plasma has been obtained at the inwardly shifted magnetic axis position of Rax = 3.60 m in which a spatial distance between the first wall on the vacuum vessel and the outermost edge boundary of the stochastic magnetic field layer existing outside the last closed flux surface takes a minimum value of ~12 mm at the inboard side. In order to investigate contact between the edge plasma boundary and the inboard first wall, a radial profile of Hβ line emissions at 4861 Å has been measured using a Czerny-Turner visible spectrometer and a 40-channel optical fiber array. All Hβ profiles measured at different magnetic axis positions of Rax = 3.60, 3.75, and 3.90 m showed a centrally peaked profile except for a few fiber channels observing the outboard edge plasma. The Hβ emission near the inboard first wall was negligibly weak, in particular, in the case of Rax = 3.60 m, suggesting no significant contact between the edge boundary plasma and the vacuum vessel first wall. The radial Hβ profile was then analyzed in detail using the EMC3-EIRENE edge plasma simulation code. The simulation well reproduced the measured profiles, including the extremely weak Hβ emission around the inboard first wall in the Rax = 3.60 m configuration. The centrally peaked profiles are found to originate in the Hβ emissions around X-points, while hydrogen neutrals are dominantly localized near the divertor plates. These results confirm the formation of a complete open divertor configuration in the LHD discharge without significant contact with the first wall. The presence of a region with extremely short magnetic field connection lengths (Lc < 5 m) between the inboard first wall and the outermost edge boundary is a key point to eliminate the strong plasma-wall interaction because sustainment of a significant edge plasma is entirely difficult in such a low Lc region.

Experimental and numerical study of stainless steel channel-to-gusset plate connections

With the advantages offered by stainless steel in terms of sustainability, mechanical performance and superiorserviceability, structural application of stainless steel is prevalent. This paper presents experimental and numerical studies of stainless steel channel-to-gusset plate connections failing by net section fracture. The experimental programme was carried out on 16 stainless steel channel-to-gusset plate connections, with each consisting of a channel section member bolted to two gusset plates by web or flange. The test setup and procedures as well as the key test results, including the failure loads, load–elongation curves, failure modes and strain distribution at critical cross-sections, were reported in detail. The effects of connection length, out-of-plane eccentricity and in-plane eccentricity on net section efficiency were discussed. Following the experimental programme, a numerical modelling programme was performed, where finite element models were firstly developed to replicate the tests and then employed to conduct parametric studies to generate further numerical data over a wide range of cross-section dimensions and connection lengths. Based on the test and numerical data, the existing design rules for stainless steel channel-to-gusset plate connections failing by net section fracture, as given in the European code and American specification, were evaluated. Generally, the European code yields excessively conservative and scattered failure load predictions, while the American specification leads to unsafe and scattered failure load predictions. An improved design approach was proposed and shown to provide substantially improved failure load predictions over the design codes.

Time-resolved structure-function coupling in brain networks

The relationship between structural and functional connectivity in the brain is a key question in systems neuroscience. Modern accounts assume a single global structure-function relationship that persists over time. Here we study structure-function coupling from a dynamic perspective, and show that it is regionally heterogeneous. We use a temporal unwrapping procedure to identify moment-to-moment co-fluctuations in neural activity, and reconstruct time-resolved structure-function coupling patterns. We find that patterns of dynamic structure-function coupling are region-specific. We observe stable coupling in unimodal and transmodal cortex, and dynamic coupling in intermediate regions, particularly in insular cortex (salience network) and frontal eye fields (dorsal attention network). Finally, we show that the variability of a region’s structure-function coupling is related to the distribution of its connection lengths. Collectively, our findings provide a way to study structure-function relationships from a dynamic perspective.

Finite element analysis of the shear capacity of stainless-steel screw connections

Stainless-steel has been widely applied in engineering for its good corrosion resistance and low life-cycle cost. The use of screws in the thin sheet has the advantages of simple construction and tight connection, so it is widely used in open-air maintenance systems. However, the mechanical performance of stainless-steel screw connections is quite different from that of carbon steel due to the material difference, which needs further research. In this paper, finite element method was carried out to simulate the shear performance of the stainless-steel screw connections. The simulated failure modes were consistent with the experimental results, the simulated load–displacement curves were close to the experimental results, and the difference was within 10%. A variety of parametric studies utilizing the finite element method (FEM) had been performed on the shear capacity of stainless-steel screw connections, which included sheet thickness, spacing and connecting length. Results shown that the connecting length was the main factor affecting the shear capacity of the stainless-steel screw connections. For equal-thickness connection (t1 = t2 = 1.5 mm, 2.0 mm, 3.0 mm), when the connecting length was within 6d-60d, the shear capacity increased linearly with the increase of the connecting length. For unequal-thickness connection (t1 = 1.5 mm, t2 = 2.0 mm/t1 = 2.0 mm, t2 = 3.0 mm/t1 = 2.0 mm, t2 = 5.0 mm), when the connecting length was within 6d-45d, the shear capacity increased linearly with the increase of the connecting length. However, when the connecting length was within 45d-60d, the end screw occurred shear failure first, its shear capacity almost no longer increased. The change of screw spacing and the sheet thickness had few effect on the shear capacity. Based on reliability research, the resistance factor and design strength were proposed. For shear failure,γR=1.273, fvb=275MPa, and for bearing failure, γR=1.306, fvb=315MPa.

Simulations of scrape-off layer power width for EAST H-mode plasma and ITER 15 MA baseline scenario by 2D electrostatic turbulence code

The scrape-off layer power width (λ q ) is an important parameter for characterizing the divertor heat loads. Many experimental, theoretical, and numerical studies on λ q have been performed in recent years. In this paper, a 2D electrostatic turbulence code, BOUT-HESEL, has been upgraded to simulate H-mode plasmas for the first time. The code is validated against the previous implementation and the experimental λ q scalings for L-mode plasmas and experiments with a typical EAST H-mode discharge. The simulated λ q is found to agree quite well with the Eich scaling [Eich et al 2013 Nucl. Fusion 53 093031] for the EAST H-mode discharge and the comparison of the probability distribution function of the parallel particle flux with the measurements by reciprocating probes is also consistent. The code is utilized to simulate the ITER 15 MA baseline scenario [Kim et al 2018 Nucl. Fusion 58 056013]. The ITER simulation reveals that the radial particle/heat transports are dominated by blobby transports, and predicts λ q,ITER = 9.6 mm, which is much larger than the prediction by the Eich scaling (λ q,ITER ≈ 1 mm). Based on the EAST modified cases, an estimated HESEL H-mode scaling, is proposed. This scaling predicts λ q,ITER = 9.3 mm, which agrees surprisingly well with that for the ITER case. A further investigation combined with the basic parameters in the database of the Eich scaling shows that the missing positive scaling dependence on the machine size (R c) in the Eich scaling appears to be shaded by the negative scaling dependence on the toroidal magnetic field (B t) for current devices. This is however not the case for ITER, explaining why simulations in recent studies and this paper can reproduce the Eich scaling for current devices, but predict a much larger λ q for ITER. According to the simulation results, the strong positive scaling dependence of λ q on R c is due to a combination of slowing down the parallel heat transports by increasing the parallel connection length and the enhancement of the radial E × B turbulent heat transports when the machine size is increased.