Simply-connected Research Articles

Associating resting-state connectivity with trait impulsivity.

Psychometric research has identified stable traits that predict inter-individual differences in appetitive motivation and approach behavior. Behavioral Inhibition System/Behavioral Activation System (BIS/BAS) scales have been developed to quantitatively assess these traits. However, neural mechanisms corresponding to the proposed constructs reflected in BIS/BAS are still poorly defined. The ventral striatum (VS) and orbitofrontal cortex (OFC) are implicated in subserving reward-related functions that are also associated with the BAS. In this study, we examined whether functional connectivity between these regions predicts components of these scales. We employed resting-state functional connectivity and BIS/BAS scores assessed by a personality questionnaire. Participants completed a resting state run and the Behavioral Inhibition and Activation Systems (BIS/BAS) Questionnaire. Using resting-state BOLD, we assessed correlations between two basal ganglia ROIs (caudate and putamen) and bilateral OFC ROIs, establishing single subject connectivity summary scores. Summary scores were correlated with components of BIS/BAS scores. Results demonstrate a novel correlation between BAS-fun seeking and resting-state connectivity between middle OFC and putamen, implying that spontaneous synchrony between reward-processing regions may play a role in defining personality characteristics related to impulsivity.

Enabling Bluetooth Low Energy auditing through synchronized tracking of multiple connections

Bluetooth Low Energy is a wireless communications protocol that is increasingly used in critical infrastructure applications, especially for inter-sensor communications in wireless sensor networks. Recent security research notes a trend in which developers and vendors have opted out of implementing Bluetooth Low Energy link security in many devices, enabling protocol attacks and attack frameworks. To help defend devices with no link security, researchers recommend the use of Bluetooth Low Energy traffic sniffers to generate auditable communications logs. Unfortunately, current sniffers can only follow a single connection at a time, and some are ineffective at capturing long-lived connections due to synchronization problems. These limitations make current sniffers impractical for use in wireless sensor networks.This paper presents Bluetooth Low Energy Multi (BLE-Multi), a firmware enhancement to the open-source Ubertooth One that enables the sniffing of multiple simultaneous long-lived connections. To increase the capture effectiveness for long-lived connections, a novel synchronization mechanism is proposed that uses transmissions of empty packets to infer information about connection timing. Multi-connection sniffing is achieved by opportunistically switching between connections as they move from the active to inactive state, which is an inherent function in Bluetooth Low Energy to help conserve energy. The experimental evaluations demonstrate that BLE-Multi simultaneously captures multiple active connections while outperforming Ubertooth One when it captures a single connection, paving the way for the development and implementation of automated defensive tools for Bluetooth Low Energy and wireless sensor networks.

Reduction of a Schwartz-type boundary value problem for biharmonic monogenic functions to Fredholm integral equations

Abstract We consider a commutative algebra 𝔹 over the field of complex numbers with a basis {e1, e2} satisfying the conditions $ (e_{1}^{2}+e_{2}^{2})^{2}=0, e_{1}^{2}+e_{2}^{2}\neq 0. $ Let D be a bounded simply-connected domain in ℝ2. We consider (1-4)-problem for monogenic 𝔹-valued functions Φ(xe1 + ye2) = U1(x, y)e1 + U2(x, y)i e1 + U3(x, y)e2 + U4(x, y)i e2 having the classic derivative in the domain Dζ = {xe1 + ye2 : (x, y) ∈ D}: to find a monogenic in Dζ function Φ, which is continuously extended to the boundary ∂Dζ, when values of two component-functions U1, U4 are given on the boundary ∂D. Using a hypercomplex analog of the Cauchy type integral, we reduce the (1-4)-problem to a system of integral equations on the real axes. We establish sufficient conditions under which this system has the Fredholm property and the unique solution. We prove that a displacements-type boundary value problem of 2-D isotropic elasticity theory is reduced to (1-4)-problem with appropriate boundary conditions.

The Cargo Fare Class Mix problem for an intermodal corridor: revenue management in synchromodal container transportation

The intermodal hinterland transportation of maritime containers is under pressure from port authorities and shippers to achieve a more integrated, efficient network operation. Current optimisation methods in literature yield limited results in practice, though, as the transportation product structure limits the flexibility to optimise network logistics. Synchromodality aims to overcome this by a new product structure based on differentiation in price and lead time. Each product is considered as a fare class with a related service level, allowing to target different customer segments and to use revenue management for maximising revenue. However, higher priced fare classes come with tighter planning restrictions and must be carefully balanced with lower priced fare classes to match available capacity and optimise network utilisation. Based on the developments of intermodal networks in North West European, such as the network of European Gateway Services, the Cargo Fare Class Mix problem is proposed. Its purpose is to set limits for each fare class at a tactical level, such that the expected revenue is maximised, considering the available capacity at the operational level. Setting limits at the tactical level is important, as it reflects the necessity of long-term agreements between the transportation provider and its customers. A solution method for an intermodal corridor is proposed, considering a single intermodal connection towards a region with multiple destinations. The main purpose of the article is to show that using a limit on each fare class increases revenue and reliability, thereby outperforming existing fare class mix policies, such as Littlewood.

Bolt Spacing and End Distance of Bolted Connection of Laminated Veneer Lumber (LVL) Sengon

This paper focuses on bolt connections on Laminated Veneer Lumber (LVL) Sengon. Series of connection tests were conducted to evaluate 3.5d, 5d, and 7d end distances and 3d, 4d, and 5d bolt spacings, where d is a 10 mm bolt diameter. All connections were double-shear model (steel-LVL-steel). The results showed that all variations of end distance failed in ductile manner especially the connections with end distances of 5d and 7d. Load carrying capacity of the connections with end distances of 5d and 7d were about the same. For single bolt connections, those with 5d bolt spacing had the highest ratio of load carrying capacity. Only the two-bolt connections with 5d bolt spacing gave the ratio of load carrying capacity higher than that of prediction. These findings therefore suggests that minimum end distance of 5d and minimum bolt spacing of 5d are recommended to be addopted in LVL Sengon bolted connections.

Spin-Transfer-Torque Driven Vortex Dynamics in Electrodeposited Nanowire Spin-Valves

A bottom-up approach for the fabrication of an assembly of electrodeposited nanowires has been combined to single nanowire electrical connection techniques to investigate the spin-transfer-torque and microwave emission of specially designed nanowires containing Co/Cu/Co pseudo spin-valves (SVs). Porous alumina templates are used for the growth by electrodeposition of metallic in-series connected SVs. Under specific magnetic field and injected current conditions, emission of microwave current is detected with frequency in the GHz range and linewidth as low as 1.8[Formula: see text]MHz. Microwave signals have been obtained even at zero magnetic field and high frequency versus magnetic field tunability was demonstrated. Our findings are in good agreement with micromagnetic simulations. In addition, it appears that in our particular geometry, the microwave emission is generated by the vortex gyrotropic motion which occurs in, at least, one of the two magnetic layers of our SV structures.

CRT-800.41 Is Percutaneous Closure Of A Secundum Atrial Septal Defect Enough, When It Is Also Associated With Single Partial Anomalous Pulmonary Venous Connection?

Partial anomalous pulmonary venous connection (PAPVC) is a relatively uncommon congenital heart defect that is usually associated with either sinus venosus or secundum atrial septal defect (ASD). Patients with an isolated single PAPVC are usually asymptomatic; whereas, co-existence of sinus venosus

A novel method linking neural connectivity to behavioral fluctuations: Behavior-regressed connectivity

BackgroundDuring an experimental session, behavioral performance fluctuates, yet most neuroimaging analyses of functional connectivity derive a single connectivity pattern. These conventional connectivity approaches assume that since the underlying behavior of the task remains constant, the connectivity pattern is also constant. New methodWe introduce a novel method, behavior-regressed connectivity (BRC), to directly examine behavioral fluctuations within an experimental session and capture their relationship to changes in functional connectivity. This method employs the weighted phase lag index (WPLI) applied to a window of trials with a weighting function. Using two datasets, the BRC results are compared to conventional connectivity results during two time windows: the one second before stimulus onset to identify predictive relationships, and the one second after onset to capture task-dependent relationships. ResultsIn both tasks, we replicate the expected results for the conventional connectivity analysis, and extend our understanding of the brain-behavior relationship using the BRC analysis, demonstrating subject-specific BRC maps that correspond to both positive and negative relationships with behavior.Comparison with Existing Method(s): Conventional connectivity analyses assume a consistent relationship between behaviors and functional connectivity, but the BRC method examines performance variability within an experimental session to understand dynamic connectivity and transient behavior. ConclusionThe BRC approach examines connectivity as it covaries with behavior to complement the knowledge of underlying neural activity derived from conventional connectivity analyses. Within this framework, BRC may be implemented for the purpose of understanding performance variability both within and between participants.

Exact Skeletonization Method in Water Distribution Systems for Hydraulic and Quality Models

A mathematical model is a powerful tool for simulating different scenarios that occur in a water distribution network without making physical experimentation. According to the objectives, a model can be classified into three categories: layout, design and operation. Furthermore, the level of detail is strongly related to the objective that the model tries to achieve. However, bigger amount of information does not mean better accuracy. For example, a fully detailed mathematical model of the network would lead to know every single connection. Usually, this information is so difficult to compile as imprecise. Therefore, one of the most important stages in elaborating a model consists of the model simplification, also known as skeletonization.During the works made for model skeletonization some assumptions are made. Most of the times, these assumptions may produce significant errors. Among the different techniques for network skeletonization, series pipe removal is one of the most used. It consists of replacing several adjacent pipes with a single one which must present the same head losses than the pipes being substituted. When there are no intermediate consumptions the problem has been effectively solved. The problem arises when a demand appears in one of the pipes being removed. It has been demonstrated that methods which assume constant roughness coefficients (either Hazen-Williams or Darcy equations) produce errors in the head losses. These errors may be even higher if travel time is included as a restriction, for example in water quality models.This paper reviews the most common techniques for serial pipes association. The error will be evaluated in both hydraulic and quality models. Finally, a method for exact substitution of serial pipes with intermediate demands is proposed. This method imposes two restrictions (head losses and travel time) and gives exact results when the flow direction is known. The method is tested with an example that highlights the results.

Multiconnectivity for Mobility Robustness in Standalone 5G Ultra Dense Networks with Intrafrequency Cloud Radio Access

Capacity and ultra-reliable communication are some of the requirements for 5th generation (5G) networks. One of the candidate technologies to satisfy capacity requirement is standalone Ultra Dense Network (UDN). However, UDNs are characterized by fast change of received signal strength that creates mobility challenges in terms of increased handovers and connection failures. In this paper, a low layer multiconnectivity scheme is presented for standalone UDN aiming at ultra-reliable communication that is free of interruptions from handover procedures and connection failures. Furthermore, the problem in managing of the set of serving cells, that are involved in multiconnectivity for each user, is formulated. By using numerical method, feasible scheme for management of the set of serving cells is derived. Performance of the proposed multiconnectivity scheme is evaluated and compared against single connectivity. It is shown that the proposed multiconnectivity scheme outperforms single connectivity considerably in terms of connection failures and cell-edge throughput.

An Innovative Substructure Damage Identification Approach for Shear Structures Based on ARMAX Models

Shear structures are used to model tall buildings which play important roles in supporting people's living and working in large cities. These buildings will be gradually deteriorated with the material aging and environmental corrosions. In this paper, an innovative substructure approach is proposed to locate and quantify damages in any storeys of a shear structure with only using three accelerometers. A multiple partition technology is used to extract physical parameters such as stiffness and damping of single inter-storey connection from an independent substructure only containing one storey cut out from the whole structure. By doing this multiple division, damages happened in multi storeys can be identified separately which is a big progress compared to previous researches that mainly consider one damaged storey in whole structure. As in the previous researches, an autoregressive-moving average with exogenous inputs (ARMAX) model is introduced to extract the modal information of each lower substructure and to encapsulate the complex input information on the boundaries of substructure, which can effectively reduce the number of sensors and the calculation process. A damage indicator combining both the information of ARMAX model parameters and model residuals is utilized to enhance the damage identification robustness, where the Kolmogorov-Smirnov (K-S) statistic test is used to evaluate the difference between ARMAX model residuals of tested substructure and of referenced substructure. Simulation of a 10-storey shear structure and an experiment of a 5-storey shear structure have been conducted to verify the effectiveness of the proposed approach, which demonstrate that the innovative approach can accurately identify the structural damages in multi storeys even with large environmental noise disturbance.

In Flight Detection and Localisation of Short Circuits on Solar Generators

In the last decades a number of failures in which a solar cell is short-circuited to the panel substrate have been reported or suspected. In the meantime protective measures, like single string connection and use of bleed resistors in the grounding circuit have been implemented. However it is still not always clear whether such an anomaly occurred and the in-flight instrumentation is usually not sufficient to provide unambiguous evidence. This paper describes a simple way to identify both the occurrence of such a cell to substrate short circuit and the panel on which it is located.The paper is then completed with the main results from the CNES study performed in 2012 to demonstrate the performance, analyse the reliability and assess the industrial feasibility of such a system.

Solution of the Problem of Linear Viscoelasticity for Multiply Connected Anisotropic Plates

Solution of the Problem of Linear Viscoelasticity for Multiply Connected Anisotropic Plates

Functional connectivity decreases in autism in emotion, self, and face circuits identified by Knowledge-based Enrichment Analysis

A powerful new method is described called Knowledge based functional connectivity Enrichment Analysis (KEA) for interpreting resting state functional connectivity, using circuits that are functionally identified using search terms with the Neurosynth database. The method derives its power by focusing on neural circuits, sets of brain regions that share a common biological function, instead of trying to interpret single functional connectivity links. This provides a novel way of investigating how task- or function-related networks have resting state functional connectivity differences in different psychiatric states, provides a new way to bridge the gap between task and resting-state functional networks, and potentially helps to identify brain networks that might be treated. The method was applied to interpreting functional connectivity differences in autism. Functional connectivity decreases at the network circuit level in 394 patients with autism compared with 473 controls were found in networks involving the orbitofrontal cortex, anterior cingulate cortex, middle temporal gyrus cortex, and the precuneus, in networks that are implicated in the sense of self, face processing, and theory of mind. The decreases were correlated with symptom severity.

Fire performance of single plate shear connections in a composite floor

Purpose This paper aims to present a numerical investigation on the fire performance of a single plate shear connection in a steel-framed composite floor. Large-scale fire experiments show that the tensile membrane action of the concrete slab enhances the fire performance of composite floors. The enhancement in the performance is contributed to large slab deflections. However, these deflections cause significant rotations and tensile force in the single plate connection. Design/methodology/approach A finite element model is constructed, which consists of a secondary steel beam, concrete slab and shear connection components. The interaction between the connection components such as bolts and single plate is defined by contact surfaces. The analysis is conducted in two uncoupled phases: thermal analysis by creating fire boundaries on the composite floor model with convective and radiative heat transfer, and mechanical analysis by considering thermal expansion and changes in the material stiffness and strength due to temperature. Findings The thermo-mechanical analysis of the composite floor finite element model shows that the structure survives the 2-h Standard fire, but the connection fails by bolt shear and buckling of the connection plate. Originality/value This paper investigates the fire performance of a shear connection in a steel-framed concrete slab. Previous work generally focused on the concrete slab behavior only. The originality of the research is that the connection is considered as part of a sub-assembly and is subjected to forces due to concrete and steel beam interaction.

Capacitively coupled pickup in MCP-based photodetectors using a conductive metallic anode

We have designed and tested a robust 20×20cm2 thin metal film internal anode capacitively coupled to an external array of signal pads or micro-strips for use in fast microchannel plate photodetectors. The internal anode, in this case a 10nm-thick NiCr film deposited on a 96% pure Al2O3 3mm-thick ceramic plate and connected to HV ground, provides the return path for the electron cascade charge. The multi-channel pickup array consists of a printed-circuit card or glass plate with metal signal pickups on one side and the signal ground plane on the other. The pickup can be put in close proximity to the bottom outer surface of the sealed photodetector, with no electrical connections through the photodetector hermetic vacuum package other than a single ground connection to the internal anode. Two pickup patterns were tested using a small commercial MCP-PMT as the signal source: 1) parallel 50Ω 25-cm-long micro-strips with an analog bandwidth of 1.5GHz, and 2) a 20×20cm2 array of 2-dimensional square ‘pads’ with sides of 1.27cm or 2.54cm. The rise-time of the fast input pulse is maintained for both pickup patterns. For the pad pattern, we observe 80% of the directly coupled amplitude. For the strip pattern we measure 34% of the directly coupled amplitude on the central strip of a broadened signal. The physical decoupling of the photodetector from the pickup pattern allows easy customization for different applications while maintaining high analog bandwidth.

Conformal Mapping for the Efficient Solution of Poisson Problems with the Kansa-RBF Method

We consider the solution of Poisson Dirichlet problems in simply-connected irregular domains. These domains are conformally mapped onto the unit disk and the resulting Poisson Dirichlet problems are solved efficiently using a Kansa-radial basis function (RBF) method with a matrix decomposition algorithm (MDA). In a similar way, we treat Poisson Dirichlet and Poisson Dirichlet---Neumann problems in doubly-connected domains. These domains are mapped onto annular domains by a conformal mapping and the resulting Poisson Dirichlet and Poisson Dirichlet---Neumann problems are solved efficiently using a Kansa-RBF MDA. Several examples demonstrating the applicability of the proposed technique are presented.

Quadratic differentials and conformal invariants

We define a notion of conformal invariance associated with nested domains, suitable for characterizing higher-order information about mapping functions. We give an exposition of our results which yield an infinite-dimensional family of conformal invariants for nested hyperbolic simply-connected domains. Each invariant is specified by a quadratic differential which is admissible for the outer domain, and is strictly negative unless the inner domain is the outer domain minus trajectories of the quadratic differential. These invariants are furthermore monotonic. Using the aforementioned invariants, we show that one can obtain various classical estimates for bounded univalent functions, and in many cases extend them, by choosing particular quadratic differentials. We also explain the principles behind these results and their context within the literature.

Monitoring the Resistance of the Military Aircraft’s Fuselage

Abstract The article includes the description of the measurements of the military aircraft’s fuselage resistance, conducted for the purpose of identifying corroded spots in the fuselage’s mechanical connections’ structure. Considerations regarding the errors in measuring the single connections of the airframe’s mechanical element pairs and the entire structure of such connections in an actual aircraft are also presented. The paper includes the proposal of the superposition method for locating the mechanical connection pairs with improved electrical resistance. Simultaneously, for the purpose of forecasting the time of exploitation of the selected (most endangered) fuselage mechanical connections pairs, the article proposes conducting (in laboratory conditions) of the accelerated ageing process and converting the results to real-time using the Arrhenius method.

Alterations of motor cortical microcircuit in a depressive-like mouse model produced by light deprivation

Depression is one of the most prevalent and life-threatening forms of mental illness. The heavy social burden imposed by this disorder calls for a better understanding of its pathogenesis. Light deficiency is an important factor potentially leading to depression. However, how the light deficiency affects neural microcircuit underlying depression remains largely unknown. This study investigated the properties of morphology, electrophysiology, and synaptology of layer V pyramidal cells (L5PCs) in the motor cortex of a mouse model with depressive behavioral phenotype that was produced by light deprivation (LD). The depressive behavioral phenotype was characterized by increased immobility and decreased locomotor activity in behavioral tests. LD decreased burst firing neurons and suppressed the intrinsic excitability of L5PCs, and also reduced the neuronal morphological complexity as evidenced by simplified basal and apical dendrites. Moreover, LD reduced the synaptic connecting probability of L5PCs. These alterations of the simplified morphology, the suppressed excitability, and the reduced connecting probability of L5PCs together could well explain the depression-like behaviors of the mouse model. However, it was surprising to find that the excitatory postsynaptic potentials (EPSPs) of single L5PC connections were significantly enhanced and the paired pulse ratio (EPSP2/EPSP1) was significantly increased. These synaptological results indicate that the absolute synaptic strength of single L5PC connections was enhanced and the transmitter release probability was increased although the connections between L5PCs became sparse. Therefore, a compensation mechanism accompanied the negative changes that were consistent with the depressive behavioral phenotype. Our findings from the motor cortex of depression-like behavior mice may underlie the neural microcircuit mechanism of depression, providing insights into the pathogenesis of depression at a level of single neurons and synaptic connections.