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Understanding how the structural organization of neural networks influences their computational capabilities is of great interest to both machine learning and neuroscience communities. In our previous work, we introduced a novel learning system, called the reservoir of basal dynamics (reBASICS), which features a modular neural architecture (small-sized random neural networks) capable of reducing chaoticity of neural activity and of producing stable self-sustained limit cycle activities. The integration of these limit cycles is achieved by linear summation of their weights, and arbitrary time series are learned by modulating these weights. Despite its excellent learning performance, interpreting a modular structure of isolated small networks as a brain network has posed a significant challenge. Here, we investigate how local connectivity, a well-known characteristic of brain networks, contributes to reducing neural system chaoticity and generates self-sustained limit cycles based on empirical experiments. Moreover, we present the learning performance of the locally connected reBASICS in two tasks: a motor timing task and a learning task of the Lorenz time series. Although its performance was inferior to that of modular reBASICS, locally connected reBASICS could learn a time series of tens of seconds while the time constant of neural units was ten milliseconds. This work indicates that the locality of connectivity in neural networks may contribute to generation of stable self-sustained oscillations to learn arbitrary long-term time series, as well as the economy of wiring cost. [ABSTRACT FROM AUTHOR]

People tend to expect mental capabilities in a robot based on anthropomorphism and often attribute the cause and responsibility for a failure in human-robot interactions to the robot. This study investigated the relationship between mind perception, a psychological scale of anthropomorphism, and attribution of the cause and responsibility in human-robot interactions. Participants played a repeated noncooperative game with a human, robot, or computer agent, where their monetary rewards depended on the outcome. They completed questionnaires on mind perception regarding the agent and whether the participant's own or the agent's decisions resulted in the unexpectedly small reward. We extracted two factors of Experience (capacity to sense and feel) and Agency (capacity to plan and act) from the mind perception scores. Then, correlation and structural equation modeling (SEM) approaches were used to analyze the data. The findings showed that mind perception influenced attribution processes differently for each agent type. In the human condition, decreased Agency score during the game led to greater causal attribution to the human agent, consequently also increasing the degree of responsibility attribution to the human agent. In the robot condition, the post-game Agency score decreased the degree of causal attribution to the robot, and the post-game Experience score increased the degree of responsibility to the robot. These relationships were not observed in the computer condition. The study highlights the importance of considering mind perception in designing appropriate causal and responsibility attribution in human-robot interactions and developing socially acceptable robots. [ABSTRACT FROM AUTHOR]

An increase in power consumption necessitates a low-power circuit technology to extend Moore's law. Low-power transistors, such as tunnel field-effect transistors (TFETs), negative-capacitance field-effect transistors (NC-FETs), and Dirac-source field-effect transistors (DS-FETs), have been realised to break the thermionic limit of the subthreshold swing (SS). However, a low-power rectifier, able to overcome the thermionic limit of an ideality factor (η) of 1 at room temperature, has not been proposed yet. In this study, we have realised a DS diode based on graphene/MoS2/graphite van der Waals heterostructures, which exhibits a steep-slope characteristic curve, by exploiting the linear density of states (DOSs) of graphene. For the developed DS diode, we obtained η < 1 for more than four decades of drain current (ηave_4dec < 1) with a minimum value of 0.8, and a rectifying ratio exceeding 108. The realisation of a DS diode represents an additional step towards the development of low-power electronic circuits. While different types of low-power transistors have been investigated, low voltage rectifiers able to overcome the thermionic limit have not been proposed yet. Here, the authors report the realization of Dirac-source diodes based on graphene/MoS2/graphite heterostructures, showing ideality factors <1 and rectifying ratios exceeding 108 at room temperature. [ABSTRACT FROM AUTHOR]

Bladder outlet obstruction (BOO) due to benign prostatic hyperplasia (BPH) is the most common cause of lower urinary tract symptoms (LUTS) in older men. Although medical treatments can reduce BPH-related LUTS and even prevent invasive treatments, at least one in five men who complain of LUTS due to BPH will eventually need surgery. Of LUTS, storage symptoms persist in 20 to 40% of patients even after the obstruction is resolved. The present study aims to investigate the predisposing factors of the persistent storage symptoms after HoLEP in patients with BPH and their correlations to the recovery time of the symptoms. A total of 127 patients with complaints of storage symptoms and who underwent transurethral HoLEP surgery at Pusan National University Hospital from May 2014 to June 2017 were included in this study. Urodynamic studies were performed in all patients, and BOO was confirmed by urodynamic studies before HoLEP. All patients were asked to complete the IPSS (also known as the American Urological Association score) and the Overactive Bladder Symptom Score (OABSS) questionnaire to evaluate LUTS on the day before HoLEP and 3 months after HoLEP. Patients were divided into group I, which included patients with persistent storage symptoms after HoLEP, and group II, which included patients without storage symptoms after HoLEP. Of a total of 127 patients, 68 were included in group I, and the remaining 59 were included in group II. In the univariable analysis, group I showed statistically significantly older mean age, higher mean peak detrusor pressure during filling cystometry, and lower mean MCC than group II. Multivariate analysis of these three variables showed that only mean age and mean peak detrusor pressure during filling cystometry had statistically significant differences. In group I, 12 patients had storage symptoms until 12 months after surgery. When comparing these patients with the remaining 56 patients, only mean age showed statistically significant differences. Old age and high peak detrusor pressure during filling cystometry were the predictors of persistent storage symptoms after HoLEP. Furthermore, older patients were unlikely to recover storage symptoms until 12 months after operation. [ABSTRACT FROM AUTHOR]

Although epidural patient-controlled analgesia (PCA) to control postoperative pain after total knee arthroplasty (TKA), the relationship of epidural PCA with postoperative bleeding remains controversial. Therefore, we aimed to evaluate the effect of epidural and intravenous PCA on postoperative bleeding in patients undergoing unilateral TKA. Total of 2467 patients who underwent TKA were divided to intravenous PCA (n = 2339) or epidural PCA (n = 128) group. After 1:1 propensity score-matching, 212 patients were analyzed to assess the associations between the perioperative blood loss and epidural PCA between the groups. Mean postoperative blood loss was significantly greater in epidural PCA than in intravenous PCA (900.9 ± 369.1 mL vs. 737.8 ± 410.1 mL; P = 0.007). The incidence of red blood cell (RBC) administration (> 3 units) was significantly higher in epidural PCA than in intravenous PCA (30.2% vs. 16.0%; OR 2.5; 95% CI 1.201–5.205; P = 0.014). Epidural PCA may be strongly related to postoperative bleeding and the incidence of RBC transfusion of more than 3 units after unilateral TKA, as compared to intravenous PCA. Therefore, the use of epidural PCA may be carefully considered for postoperative pain management in TKA. [ABSTRACT FROM AUTHOR]

In this study, the applicability of the composite model for assessing seawater intrusion and soil salinization in coastal aquifers due to climate change was investigated. In this approach, flow in the saturated zone of a coastal aquifer is simulated using a three-dimensional saturated–unsaturated transport model and flow in the unsaturated zone between the surface and groundwater level is simulated using a one-dimensional model in the vertical direction. Long-term sea-level predictions obtained using the representative concentration pathway (RCP) 4.5 and 8.5 scenarios were applied for computing the sea-level rise for 91 country-managed reclaimed areas in the Republic of Korea. Composite results were obtained and analyzed for seawater intrusion and soil salinization due to sea-level rise. In the results of groundwater and soil salinity in all 91 reclaimed land, the increasing rate of groundwater and soil salinity in the RCP 4.5 scenario was 13.5% and 10.4%, respectively. In the RCP 8.5 scenario, the increasing rate of groundwater and soil salinity was 14.1% and 11.1%, respectively. The groundwater level increased to 0.41 m in the RCP 4.5 scenario and 0.51 m in the RCP 8.5 scenario. The results for two representative reclaimed land areas in the Heungwang and Deokchon districts were examined in detail. The composite analysis revealed that widespread damage could be caused by sea-level rise in the reclaimed land and that seawater intrusion in many regions will accelerate groundwater salinization over time. Moreover, the reclaimed land areas were characterized in terms of watershed size, presence of ponds, water levels of the ponds, and pond locations. In reclaimed land located in small watersheds, the groundwater recharge area was smaller than in land located in larger watershed areas. Consequently, the seawater in small watersheds penetrated further inland. Ponds with water levels higher than the sea level effectively prevented seawater intrusion into groundwater. If the water level of a pond is similar to or lower than the sea level, it indicates that seawater has already penetrated a large part of the aquifer. The composite model developed in this study seems to be one of the simulation methods that can be applied when simulating saturated and unsaturated zone to a large number of sites. Also, the study results could be used to establish and implement a long-term comprehensive plan for water resources at the national level, considering seawater intrusion due to climate change and providing a basis for establishing countermeasures against future seawater intrusion. [ABSTRACT FROM AUTHOR]

The dilution effect caused by boundary-layer evolution over land has strong influences on air quality. Accurate and continuous measurements of the boundary-layer height over urban areas are therefore needed for complete air-quality assessments. Commercial ceilometers, in combination with reliable and simple methodologies, can be used to retrieve the mixed-layer height, and represent a means of obtaining information on vertical mixing and atmospheric structure above cities. Here, we evaluate various retrieval algorithms based on the gradient method against high-temporal-resolution radiosonde observations. Based on the results, we propose a simple algorithm by using the gradient method, the correction of background noise and the moving averages, with the minimum number of parameters that need to be adjusted to the local properties and the instrument itself. The algorithm is adjusted for Seoul, Korea, and improves the retrieval performance by reducing high-frequency noise. The algorithm is used to investigate the relationship between the evolution of the daytime mixed-layer height and air pollution under a two-layer mixing model where changes in concentration depend only on the urban boundary-layer growth and air entrainment from the free atmosphere. Using 2 months of ceilometer retrievals of mixed-layer height and air-quality data from across the city, we find strong negative correlations for primary emitted pollutants such as NO2, CO, SO2, and particulate matter smaller than 10 µm, and a modest positive correlation for O3. The results provide insight into the significant influence of urban boundary-layer evolution on Seoul's air quality. [ABSTRACT FROM AUTHOR]

The ferromagnetic MnAl-C powders were prepared by using a one-step solid-state reaction method starting from Mn micro-/nano-particles and Al/C micropowders. The bulk MnAl-C with enhanced coercivity was prepared by high-pressure compaction of these MnAl-C powders. The grain size of the τ-phase was significantly reduced during high-pressure compaction, which may also result in a decomposition of the τ-MnAl. Carbon element stabilizes the τ-phase under both ambient and high pressures. The annealing temperature and time intervals are crucial for the preparation of high purity τ-phase samples. The MnAl-C with smaller particle size were produced from Mn nanoparticles. In comparison with the samples prepared from Mn micropowders, the product prepared from Mn nanoparticles shows lower purity, owing to the surface oxidation of the precursor nanoparticles. After high pressure compaction, the coercivities of the bulk MnAl and MnAl-C were increased from 0.05 T and 0.08 T to 0.39 T and 0.22 T, respectively. The room temperature magnetization of the MnAl-C sample at 4 T reached up to 95 Am2/kg. [ABSTRACT FROM AUTHOR]

Bulk MnAl-C magnets were prepared via high-pressure compaction of melt-spun ribbons. The ε → τ phase transformation (PT) in the melt-spun MnAl and MnAlC ribbons occurs mainly via the massive mode, whereas the displacive mode is not prominent. The massive PT temperatures of the melt-spun MnAl and MnAlC ribbons were measured to be in the range 660-739 K and 700-758 K, respectively. The PT temperatures of the melt-spun MnAlC ribbons are lower than those of water-quenched MnAlC. The annealing process for producing τ-phase from ε-phase was optimized based on the measured PT temperature range. As a result, no decomposition of the metastable ε/τ-phase MnAl and MnAlC were observed during the optimized high temperature annealing. High-purity τ-phase MnAlC ribbons with high magnetization (122 Am2/kg at 8 T) and low coercivity (0.13 T) were obtained. The coercivity of the bulk MnAlC obtained by high-pressure compaction was significantly enhanced and reached 0.38 T partially due to the grain refinement of the sample during high-pressure deformation. [ABSTRACT FROM AUTHOR]

M-type strontium ferrite (SrFeO: SrM) with two different shapes were synthesized by a simple and benign process. One is peanut-like shape, and the other is hexagonal platelet. These shapes were controlled by the shape and size of precursor FeO particles. A mixture of submicron- or nanometer-sized FeO particles and SrCO nanoparticles was calcined to transform to SrM, followed by acid-washing to remove secondary phase from SrM particles. Static magnetic properties, magnetic interactions, and thermomagnetic stability of the SrM particles were studied. The measured saturation magnetization and intrinsic coercivity are 74.2 emu/g and 4431 Oe, respectively, for the peanut-like SrM particles and 73.6 emu/g and 5360 Oe for the hexagonal SrM platelets. The saturation magnetization is close to the theoretical value of 76 emu/g. Both types of SrM show dipolar interactions and good thermomagnetic stability, i.e. α = Δ σ/ σ = −0.16%/K and β = Δ H/ H = 0.15%/K for the peanut-like SrM particles and α = −0.12%/K and β = 0.12%/K for the hexagonal SrM platelets. The temperature coefficient of intrinsic coercivity ( β) is positive and magnetization still remains high at 400 K; 60 emu/g for the hexagonal SrM platelets and 50 emu/g for the peanut-like SrM particles. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

SrFeO/Fe-Co core/shell particles with different shell thickness were synthesized by polyol reduction of Fe and Co ions at 180°C with SrFeO particles dispersed in solvent. The core/shell structure is formed by magnetic self-assembly due to the remanent magnetization of SrFeO particles. Within a limited concentration range, the shell thickness could be controlled by regulating the concentration of Fe and Co ions. Core/shell structured SrFeO/Fe-Co particles showed more effective exchange coupling effects between hard and soft phases than physically mixed SrFeO and Fe-Co particles. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Effective speckle reduction is important for enhancing image quality and improving our understanding of medical ultrasound imaging. Various speckle reduction techniques, such as frequency compounding (SR-FC), spatial compounding (SRSC), and post filtering (SR-PF), have been proposed. In SRFC, uncorrelated sub-images, which are obtained by either varying the center frequency on transmission or by dividing the spectrum of radio-frequency (RF) signals on reception, are compounded to lower speckle. In SR-SC, the sub-images are acquired at different beam orientations at the expense of temporal resolution. On the other hand, in SR-PF, instead of compounding multiple sub-images, a specially designed spatial filter, e.g., Laplacian pyramid-based nonlinear diffusion, is applied to a single image. These techniques can be integrated together to maximize the effects of speckle reduction. This review briefly introduces the principles behind three speckle reduction techniques and describes their own strengths and weaknesses. Finally, some clinical examples of speckle reduction techniques are presented. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, we consider the maximum likelihood and Bayes estimation of the scale parameter of the half-logistic distribution based on a multiply type II censored sample. However, the maximum likelihood estimator(MLE) and Bayes estimator do not exist in an explicit form for the scale parameter. We consider a simple method of deriving an explicit estimator by approximating the likelihood function and discuss the asymptotic variances of MLE and approximate MLE. Also, an approximation based on the Laplace approximation () is used to obtain the Bayes estimator. In order to compare the MLE, approximate MLE and Bayes estimates of the scale parameter, Monte Carlo simulation is used. [Copyright &y& Elsevier]

As control algorithms become increasingly sophisticated, delivering improved performance at the expense of greater complexity, practical experiments often become unfeasible. To address this challenge, this study introduces a novel rapid control prototyping (NRCP) approach based on model-based design (MBD) using MATLAB/Simulink, STM32CubeMX software, and field-oriented control strategies for permanent magnet synchronous motors. Compared with existing rapid control prototyping methods, our NRCP design offers several advantages: it simplifies model construction by utilizing only basic Simulink modules, minimizes dependency on MATLAB/Simulink toolboxes by only requiring Embedded Code conversion to C language, and ensures strong compatibility as the experimental code involves only C language. To demonstrate the feasibility and efficiency of this approach, sensor-based and sensorless control models were developed using the MBD method. The practicality of the NRCP was successfully validated through sensor-based and sensorless experiments using an ARM Cortex-M4-based STM32 microcontroller. [ABSTRACT FROM AUTHOR]