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Automatic modulation classification (AMC) is one of the major challenges for cognitive radio (CR), which can enhance the spectrum utilization efficiency. In this study, a hybrid signal and image-based deep learning model is designed for AMC in CR. A convolutional neural network (CNN) is applied in both the deep learning models. The signal-based CNN (SBCNN) is designed with the optimal filter size for the prediction accuracy, which is used as a pre-training deep learning network to extract features with size 24×1. The features extracted by SBCNN are converted into heat map images, which showed RGB images in the scale range of -30 to +30. Finally, the images are utilized for training and testing the image-based CNN (IBCNN). The dataset used for the experiment is DeepSig:RADIOML2018.01A, which is the latest version. For the IBCNN, the prediction accuracy is 1.96%, 7.99%, and 4.63% higher at signal-to-noise ratio (SNR) 10 dB, and 3.26%, 6.4%, and 4.13% higher at SNR 0 dB as compared to conventional models: ECNN, SCGNet, and LCNN, respectively.

Objective A shorter door-to-puncture time is an independent predictor of good clinical outcomes in patients with acute ischemic stroke (AIS) who undergo mechanical thrombectomy (MT). We recently initiated a protocol for direct care from neurointerventionalists (NIs) in the emergency department (ED) rather than from non-NI neurologists for patients with AIS. Our aim was to investigate whether NIs, as the first point-of-care physicians for stroke in the ED, could shorten door-to-puncture time compared to non-NI neurologists. Methods From January 2020 to December 2020, 50 patients with AIS underwent MT at our hospital. Patients were divided into 2 groups based on the type of physician who provided initial care for stroke in the ED: (a) NI group (n = 20) and (b) non-NI group (n = 30). The door-to-puncture time was retrospectively analyzed. Results The NI group had a significantly shorter door-to-puncture time than the non-NI group (135.2 ± 50.0 minutes vs. 167.2 ± 54.3 minutes, P = 0.040). A door-to-puncture time of ≤120 minutes was more frequently achieved in the NI group than in the non-NI group (55.0% vs. 23.3%, P = 0.022). Multivariable logistic regression analysis revealed that a door-to-puncture time of ≤120 minutes was independently associated with the NI group (adjusted odds ratio 4.098, 95% confidence interval 1.085–15.479, P = 0.037). Conclusions Our study showed that NIs, as the first point-of-care stroke physicians in the ED, were associated with shorter door-to-puncture times. We suggest that NIs should be at the forefront of care for patients with AIS in the acute setting by performing triage and deciding on and performing MT.

The effects of a metal–interlayer–semiconductor (MIS) source/drain (S/D) contact structure on a dynamic random access memory (DRAM) cell transistor are investigated using 3-D technology computer-aided design simulation. When the MIS S/D contact structure is used in a DRAM cell, the retention time increases by approximately 16.22 times when compared with that of the device using the metal–semiconductor (MS) S/D contact structure owing to the lowered S/D doping concentration, leading to a decrement of the gate-induced drain leakage. Furthermore, the write time and charge-sharing time, respectively, are approximately 0.74 and 0.69 times shorter when compared with the device using the MS S/D contact structure owing to better ohmic characteristics, which increase the drain current during the write/read operations. Thus, the MIS S/D contact structure can effectively enhance the retention and write/read characteristics of a DRAM cell, and it can be a promising S/D contact alternative for the DRAM cell in the sub-2y-nm technology node.

In modern-day multi-dimensional recreational drones (UAVs), the global navigation satellite system (GNSS) units in- use are commonly fraught with precise-point-positioning (PPP) data errors or inaccuracies, hence, necessitating this work. These data inaccuracies, occasioned by the system’s drawbacks such as sudden GPS lock or jamming, embedded device misalignment, drone’s limited communication coverage, signaling and detection, all contributes to the system’s PPP computation complexity. To mitigate PPP complexity, an intelligent and robust accurate continuous-discrete (ACD) based hybrid cubature-extended Kalman filter (C-EKF) computation model for an integrated GNSS unit is corroborated in this article. More precisely, time updates to the state and parameter sub-vectors for the GNSS unit is accomplished using the third-degree spherical-radial cubature rule. The system’s testbed simulation is then conducted using tightly-coupled units of (i) ring laser gyroscope (RLG) and (ii) micro-electro-mechanical system (MEMS) variants of the inertial measurement unit (IMU) to ascertain the PPP cooperative tendencies. Optimized performance comparisons of the proposed hybrid C-EKF over the existing cubature Kalman filter (CKF) and extended Kalman filter (EKF) models with-respect-to (w.r.t) its probabilistic outages, Yaw error-differences and ergodic capacities are demonstrated and presented.

In this paper, a novel deep learning-based robust automatic modulation classification (AMC) method is proposed for cognitive radio networks. Generally, as network input of AMC convolutional neural networks (CNNs) images or complex signals are utilized in time domain or frequency domain. In terms of the image that contains RGB(Red, Green, Blue) levels the input size may be larger than the complex signal, which represents the increase of computational complexity. In terms of the complex signal it is normally used as $2 \times N$ size for the input, which is divided into in-phase and quadrature-phase (IQ) components. In this paper, the input size is extended as $4 \times N$ size by copying IQ components and concatenating in reverse order to improve the classification accuracy. Since the increase in the amount of computation complexity due to the extended input size, the proposed CNN archiecture is designed to reduce the size from $4 \times N$ to $2 \times N$ by an average pooling layer, which can enhence the classification accuracy as well. The simulation results show that the classification accuracy of the proposed model is higher than the conventional models in the almost signal-to-noise ratio (SNR) range.

In this research, we proposed an effective approach to investigate the importance and satisfaction attributes of service quality of a restaurant business. For understanding the gaps of service qual...

Automatic modulation classification (AMC) used in cognitive radio networks is an important class of methods apt to utilize spectrum resources efficiently. However, conventional likelihood-based approaches have high computational complexity. Thus, this paper proposes a novel convolutional neural network architecture for AMC. A bottleneck and asymmetric convolution structure are employed in the proposed model, which can reduce the computational complexity. The skip connection technique is used to solve the vanishing gradient problem and improve the classification accuracy. The dataset DeepSig:RadioML, which is composed of 24 modulation classes, is used for the performance analysis. Simulation results show that the classification accuracy performance of the proposed model is outstanding in the signal-to-noise ratio (SNR) range from $- 4\,\,dB$ to $20~dB$ compared with MCNet that is the best model in the conventional models, where the proposed model achieves 5.52% and 5.92% improvement regarding classification accuracy at the SNRs of $0~dB$ and $10~dB$ , respectively. In terms of the computational complexity, the proposed model not only saves the trainable parameters by more than 67% but also reduces the prediction time for a signal by more than 54.4% compared with those of MCNet.

A low on–off current modulation ratio (ION/OFF) in p-type tin monoxide (SnO) field-effect transistors (FETs) is a critical bottleneck hampering their widespread application to transparent complementary metal oxide semiconductors (CMOSs) or monolithic integrated devices. To solve this problem, this study focuses on the source/drain (S/D) contact region. Also, a new perspective on the origin of the high off-current in SnO FETs, an electron injection from the drain electrode into the channel by Fermi-level pinning (FLP) at the off-state, is suggested. In this work, a metal–interlayer–semiconductor (MIS) S/D contact structure is adopted to suppress this adverse electron injection. An ultrathin interlayer (IL) of MIS contact alleviates metal-induced gap state (MIGS) penetration which is a primary cause of the severe FLP. A considerable enhancement is achieved by using the MIS contact structure: the off-current value decreased by approximately 20-fold from 5.1 × 10−8 A to 2.4 × 10−9 A; the ION/OFF value increased 10-fold from 2.7 × 102 to 2.8 × 103, which is interpreted by increased MIS contact-mediated electron SBH. This work presents a new approach that can be easily used alongside previously reported methods to suppress the off-current, providing enhanced switching capability of p-type SnO FETs using a simple method.

Egypt is one of the largest Islamic developing countries trying to improve their economies and the development of Small and Medium-sized Enterprises (SMEs) has been suggested as a potential means of doing so. This paper analyzed multiple macro level economic factors that can help the development of the Egyptian SMEs based on the data from World Bank. Our results showed that increasing the sources for financing SMEs by loans and the claims on government may facilitate the growth of Egyptian SMEs. In addition, we found that just increasing exports by eliminating the barriers that hinder Egyptian exports may not help the SMEs’ development. Finally, in the current social and economic circumstances, increasing the use of internet was found to be not significant in contributing to Egyptian SMEs. The implications from the results and the recommendations for developing Egyptian SMEs are also suggested.

Capabilities for continuous monitoring of pressures and temperatures at critical skin interfaces can help to guide care strategies that minimize the potential for pressure injuries in hospitalized patients or in individuals confined to the bed. This paper introduces a soft, skin-mountable class of sensor system for this purpose. The design includes a pressure-responsive element based on membrane deflection and a battery-free, wireless mode of operation capable of multi-site measurements at strategic locations across the body. Such devices yield continuous, simultaneous readings of pressure and temperature in a sequential readout scheme from a pair of primary antennas mounted under the bedding and connected to a wireless reader and a multiplexer located at the bedside. Experimental evaluation of the sensor and the complete system includes benchtop measurements and numerical simulations of the key features. Clinical trials involving two hemiplegic patients and a tetraplegic patient demonstrate the feasibility, functionality and long-term stability of this technology in operating hospital settings.

Capabilities for continuous monitoring of pressures and temperatures at critical skin interfaces can help to guide care strategies that minimize the potential for pressure injuries in hospitalized patients or in individuals confined to the bed. This paper introduces a soft, skin-mountable class of sensor system for this purpose. The design includes a pressure-responsive element based on membrane deflection and a battery-free, wireless mode of operation capable of multi-site measurements at strategic locations across the body. Such devices yield continuous, simultaneous readings of pressure and temperature in a sequential readout scheme from a pair of primary antennas mounted under the bedding and connected to a wireless reader and a multiplexer located at the bedside. Experimental evaluation of the sensor and the complete system includes benchtop measurements and numerical simulations of the key features. Clinical trials involving two hemiplegic patients and a tetraplegic patient demonstrate the feasibility, functionality and long-term stability of this technology in operating hospital settings., Uninterrupted monitoring of pressure and temperature at skin interfaces can help to minimize the potential for pressure injuries in hospitalized or bedridden patients. Here, the authors introduce a soft, skin-mountable sensor that can continuously provide readings via antennas mounted under bedding, and demonstrate the functionality and robustness of the devices on patients.

For next‐generation electronics and optoelectronics, 2D‐layered nanomaterial‐based field effect transistors (FETs) have garnered attention as promising candidates owing to their remarkable properties. However, their subthreshold swings (SS) cannot be lower than 60 mV/decade owing to the limitation of the thermionic carrier injection mechanism, and it remains a major challenge in 2D‐layered nanomaterial‐based transistors. Here, a gate‐connected MoS2 atomic threshold switching FET using a nitrogen‐doped HfO2‐based threshold switching (TS) device is developed. The proposed device achieves an extremely low SS of 11 mV/decade and a high on‐off ratio of ≈106 by maintaining a high on‐state drive current due to the steep switching of the TS device at the gate region. In particular, the proposed device can function as an infrared detectable phototransistor with excellent optical properties. The proposed device is expected to pave the way for the development of future 2D channel‐based electrical and optical transistors., Gate‐connected atomic threshold switching field‐effect transistor with MoS2 channel using threshold switch mechanism is investigated to achieve low subthreshold swing of 11.1 mV/decade for various electric and optoelectronic nanodevices. In addition, the proposed device can be used as an infrared detectable phototransistor and achieves significantly high optical performance (I light/dark = 4.7 × 104 and D * = 2.7 × 1012 cmHz0.5W−1).

Layered two-dimensional (2D) materials have entered the spotlight as promising channel materials for future optoelectronic devices owing to their excellent electrical and optoelectronic properties....

Energy barrier formed at a metal/semiconductor interface is a critical factor determining the performance of nanoelectronic devices. Although diverse methods for reducing the Schottky barrier height (SBH) via interface engineering have been developed, it is still difficult to achieve both an ultralow SBH and a low dependence on the contact metals. In this study, a novel structure, namely, a metal/transition-metal dichalcogenide (TMD) interlayer (IL)/dielectric IL/semiconductor (MTDS) structure, was developed to overcome these issues. Molybdenum disulfide (MoS2) is a promising TMD IL material owing to its interface characteristics, which yields a low SBH and reduces the reliance on contact metals. Moreover, an ultralow SBH is achieved via the insertion of an ultrathin ZnO layer between MoS2 and a semiconductor, thereby inducing an n-type doping effect on the MoS2 IL and forming an interface dipole in the favorable direction at the ZnO IL/semiconductor interfaces. Consequently, the lowest SBH (0.07 eV) and ...

The need for soft whole-body tactile sensors is emerging. Piezoresistive materials are advantageous in terms of making large tactile sensors, but the hysteresis of piezoresistive materials is a major drawback. The hysteresis of a piezoresistive material should be attenuated to make a practical piezoresistive soft tactile sensor. In this paper, we introduce a low-hysteresis and low-interference soft tactile sensor using a conductive coated porous elastomer and a structure to reduce interference (grooves). The developed sensor exhibits low hysteresis because the transduction mechanism of the sensor is dominated by the contact between the conductive coated surface. In a cyclic loading experiment with different loading frequencies, the mechanical and piezoresistive hysteresis values of the sensor are less than 21.7% and 6.8%, respectively. The initial resistance change is found to be within 4% after the first loading cycle. To reduce the interference among the sensing points, we also propose a structure where the grooves are inserted between the adjacent electrodes. This structure is implemented during the molding process, which is adopted to extend the porous tactile sensor to large-scale and facile fabrication. The effects of the structure are investigated with respect to the normalized design parameters θ D , θ W , a n d θ T in a simulation, and the result is validated for samples with the same design parameters. An indentation experiment also shows that the structure designed for interference reduction effectively attenuates the interference of the sensor array, indicating that the spatial resolution of the sensor array is improved. As a result, the sensor can exhibit low hysteresis and low interference simultaneously. This research can be used for many applications, such as robotic skin, grippers, and wearable devices.

The aim of this study is to determine whether there is a significant relationship between certain insomnia symptoms and drinking water shortly before bedtime as seen anecdotally in a clinical setting. A survey was done of 1223 patients receiving standard physical exams at a large hospital in Taiwan. Every patient was asked whether they were willing to answer a series of questions; if they agreed, they were given the questionnaire. Information in questionnaire form was gathered concerning demographic information and about pre-bedtime lifestyle habits of the respondents, including whether they drank specified beverages. Analysis of the data revealed three discrete classes based on the degree of their insomnia symptoms: Group 1, Group 2, and Group 3. From the multivariate logistic regression mode, Group 2 and Group 3 show a higher proportion of beverage-drinking behavior of study participants before going to bed than Group 1. Group 3 and Group 2 have ORs of 1.59 (P

Schottky barrier height (SBH) engineering of contact structures is a primary challenge to achieve high performance in nanoelectronic and optoelectronic applications. Although SBH can be lowered thr...

Probing micro-bumps for pre-bond testing is an essential process to check for a known good die. In recent technologies, micro-bumps such those used in 3-D-IC are too small and dense, which gives the probing a new challenge. Moreover, developers are concerned that the tip ends of the micro-bumps are mechanically damaged during the pre-bond testing, which is detrimental for the post-process IC assembly. Thus, many low damage probing solutions have been developed, but they still inevitably damage the tip end of the micro-bumps when the conventional probing method, vertical contact, is used. In this paper, for the first time, we demonstrate lateral contact probing on 55- $\mu \text{m}$ pitch micro-bumps without any damage to the tip ends. We successfully realized the testing with monolithically fabricated probes by nickel electroplating with a high aspect ratio photoresist mold. The measured fatigue life of the fabricated probes was at least100 000 cycles. Furthermore, the measured current carrying capacity was more than 180 mA. Proving our concept, the contact test results on the micro-bumps showed no damage to the tip end, and the contact resistance was below 1.13 $ {\Omega }$ . Finally, the10 000 probes achieved a uniform 55- $\mu \text{m}$ pitch, which ensured the possibility in real testing. [2018-0041]

We present a novel hybrid dopant activation technique for n-type silicon–germanium (SiGe) to achieve high doping concentration and ultra-shallow junction at low temperature (≤500 °C) using rapid thermal annealing and pulsed green laser post-annealing (hybrid RTA-GLA). The hybrid RTA-GLA process achieved one of the highest surface and peak doping concentrations of $1.82\times 10^{\textsf {20}}$ cm−3 and $9.27\times 10^{\textsf {20}}$ cm−3, respectively, compared with low-temperature doping techniques for n-type SiGe. In addition, the n-type SiGe films doped by the hybrid RTA-GLA process provide ultra-shallow (

In this paper, a prioritized-MAC protocol model for unmanned aerial vehicle (UAV) data collection and processing in an industrial wireless sensor network system (IWSN) is proposed. The model encapsulates the existing legacy IEEE 802.11 carrier-sense multiple access collision avoidance (CSMA/CA) MAC protocol, where nodes are kept active when in UAV’s coverage area. A level-sided access channel approach is then deployed to distinguish the priority allotment to each ground node using the distributed coordinated function inter-frame spacing (DCFIS) approach. Consequently, nodes located at the highest priority level-sided frame have shorter time-length with more DCFIS values than those of lower priority level-sided frames. On simulation, our proposed protocol not only improves fairness, but enhances network fairness with reduced delay time.

In this paper, the eight schemes for aircraft wireless sensor networks are investigated, which are single-hop array beamforming schemes (including analog beamforming (ABF), and digital beamforming (DBF)), non-cooperative schemes (including single-hop and multi-hop schemes), cooperative schemes (including amplify and forward (AF), decode and forward (DF)), and incremental cooperative schemes (incremental decode and forward (IDF), and incremental amplify and forward (IAF)). To set up the aircraft wireless communication environment, we design the aircraft channel model by referring to the experimental parameters of the ITU (International Telecommunication Union)-R M.2283, which is composed of path loss, shadowing fading, and multi-path fading channel responses. To evaluate the performance, the conditions energy consumption and throughput analysis are performed. Through simulation results, the incremental cooperative scheme outperformed by 66.8% better at spectral efficiency 2 than the DBF scheme in terms of the energy consumption metric. Whereas, in terms of throughput metric, overall SNR (signal-to-noise ratio) ranged from &minus, 20 to 30 dB the beamforming scheme had the best performance in which the beamforming scheme at SNR 0 dB achieved 85.4% better than the multi-hop scheme. Finally, in terms of normalized throughput metric in low SNR range between &minus, 20 and 1 dB the ABF scheme had the best performance over the others in which the ABF at SNR 0 dB achieved 75.4% better than the multi-hop scheme. Whereas, in high SNR range between 2 and 30 dB the IDF scheme had the best performance in which the IDF at SNR 10 dB achieved 62.2% better than the multi-hop scheme.

Recently, deep learning (DL) is an innovative machine learning (ML) technique that has gained the outstanding achievements in computer vision and natural language processing. This work takes advantage of DL for effectively handling automatic modulation classification (AMC), which is the fundamental function of numerous cognitive radio-based and spectrum sensing-based applications in many modern communication systems. Concretely, a novel deep convolutional neural network (DCNN) is proposed for learning a classification model from a massive amount of modulated signals, in which the network architecture has several convolutional blocks specialized to simultaneously capture the temporal intra-signal correlations and the spatial inter-signal relations. To this end, each block comprises various convolutional layers of asymmetric convolution kernels, whose outputs are gathered via a concatenation layer. For the enrichment of multi-scale deep feature and the prevention of gradient vanishing problem, these blocks are associated by skip connections to take into account the useful residual information. In experiments, the proposed CNN-based AMC method achieves the overall 24-modulation classification rate of 88.22% at 10dB SNR on the well-known DeepSig dataset.

Numerous existing handcrafted feature-based and conventional machine learning-based approaches cannot seize the intensive correlations of skeleton structure in the spatiotemporal dimension. On another hand, some modern methods exploiting Long Short Term Memory (LSTM) to learn temporal action attribute, which lack an efficient scheme of revealing high-level informative features. To handle the aforementioned issues, this research introduces a novel hierarchical deep feature fusion model for 3D skeleton-based human action recognition, in which the deep information for modeling human appearance and action dynamic is gained by Convolutional Neural Networks (CNNs). The deep features of geometrical joint distance and orientation are extracted via a multi-stream CNN architecture to uncovering the hidden correlations in both the spatial and temporal dimensions. The experimental results on the NTU RGB+D dataset demonstrates the superiority of the proposed fusion model against several recently deep learning (DL)-based action recognition approaches.

The study was designed to examine the effects of aerobic exercise training on body composition, insulin resistance and appetite control hormone of obese college female students. Eighteen obese college female students were volunteered to participate in this study as subjects, and they were randomly assigned to either aerobic exercise training group(n=9) or control group(n=9). The subjects in aerobic exercise training program for 50min/session, four times per week for 10 weeks, whereas subjects in control were asked to maintain their normal life pattern for the same intervention period. All subjects were asked not to change their physical activity pattern and energy intake throughout the intervention period. Main results of the present study were as follows: 1) Weight, BMI, and % body fat were significantly decreased in aerobic exercise training group. 2) Insulin and insulin resistance were significantly decreased in aerobic exercise training group. But Insulin and insulin resistance were significantly increased in control group. 3) Leptin was significantly decreased in aerobic exercise training group. But ghrelin was not changed significantly in both groups. It was concluded that 12 weeks of aerobic exercise training would be beneficial for body composition, insulin resistance and appetite control hormone in obese college female students.

The excellent Schottky barrier height (SBH) lowering effect of the metal/In0.53Ga0.47As contact is demonstrated to achieve extremely low contact resistance for n-channel InxGa1−xAs-based devices. Severe Fermi-level pinning, caused by large amounts of metal-induced gap states (MIGS) and interface states at the In0.53Ga0.47As surface, can be effectively alleviated, and the large SBH of the metal/In0.53Ga0.47As interface can be significantly lowered by introducing a metal-interlayer-semiconductor (MIS) structure, with the insertion of an Al-doped ZnO (AZO)/Ge interlayer stack between the metal and the In0.53Ga0.47As. The AZO interlayer is used as a heavily doped interlayer to reduce the MIGS, decrease its tunneling thickness, and lower the SBH. Reduction of the interface states at the In0.53Ga0.47As surface is achieved by adopting an ultrathin Ge layer as the surface passivation layer. Furthermore, a favorable interfacial dipole is formed at the AZO/Ge/In0.53Ga0.47As interfaces, which induces further SBH lowering and reduction of the AZO tunneling thickness. A below zero effective SBH for a Ti/AZO (1.2 nm)/Ge (0.5 nm)/n+-In0.53Ga0.47As (Nd = 1 × 1019 cm−3) structure is estimated while the SBH of the Ti/n+-In0.53Ga0.47As structure is 0.27 eV. A specific contact resistivity value of (8.3 ± 2.6) × 10−9 Ω cm2 is achieved for the proposed MIS structure, which is one of the lowest reported values for ohmic contacts to date. This result suggests that the proposed MIS structure, incorporating the AZO/Ge interlayer stack, presents a promising ohmic contact technique for III–V compound semiconductor-based applications.

In this paper, the effects of a metal–interlayer–semiconductor (MIS) source/drain (S/D) structure with a heavily doped interlayer on enhancement-mode n-type germanium (Ge) junctionless FinFETs (JLFETs) are demonstrated via 3-D technology computer aided design simulation. N-type Ge JLFETs using metal–semiconductor (MS) S/D structures face difficulty in operating in the enhancement mode, as severe Fermi-level pinning (FLP) triggers extremely high off-state current ( ${I}_{ \mathrm{OFF}}$ ) and extremely low on-state current ( ${I}_{ \mathrm{ON}}$ ). The MIS S/D structure can solve these problems by mitigating FLP. In the simulation of an n-type Ge JLFET with the MIS S/D structure, ${I}_{ \mathrm{OFF}}$ of $9.42 \times 10^{-10}$ A/ $\mu \text{m}$ , ${I}_{ \mathrm{ON}}$ of $6.09 \times 10^{{-4}}$ A/ $\mu \text{m}$ , and subthreshold slope of 65.38 mV/dec are achieved. The performance of the device for different channel-doping concentrations and fin dimensions is also evaluated. Thus, an MIS S/D structure with a heavily doped interlayer can effectively strengthen the performances of n-type Ge JLFETs beyond the sub-7-nm technology node.

The difficulty in Schottky barrier height (SBH) control arising from Fermi-level pinning (FLP) at electrical contacts is a bottleneck in designing high-performance nanoscale electronics and optoelectronics based on molybdenum disulfide (MoS2). For electrical contacts of multilayered MoS2, the Fermi level on the metal side is strongly pinned near the conduction-band edge of MoS2, which makes most MoS2-channel field-effect transistors (MoS2 FETs) exhibit n-type transfer characteristics regardless of their source/drain (S/D) contact metals. In this work, SBH engineering is conducted to control the SBH of electrical top contacts of multilayered MoS2 by introducing a metal–interlayer–semiconductor (MIS) structure which induces the Fermi-level unpinning by a reduction of metal-induced gap states (MIGS). An ultrathin titanium dioxide (TiO2) interlayer is inserted between the metal contact and the multilayered MoS2 to alleviate FLP and tune the SBH at the S/D contacts of multilayered MoS2 FETs. A significant alle...

We present a universal metal–interlayer–semiconductor (MIS) contact model to demonstrate the effect of Fermi-level unpinning, considering both the extrinsic interface-state density ( ${D} _{\textsf {it}}$ ) and the density of metal-induced gap states ( ${D} _{\textsf {MIGS}}$ ) at the semiconductor surface. Previous studies on MIS contact modeling have quantified only the impact of ${D} _{\textsf {MIGS}}$ on Fermi-level pinning. However, the extrinsic interface states such as interface traps and local vacancies significantly affect the contact resistivity degradation in MIS contacts. Moreover, field emission (FE) and thermionic FE (TFE) current density models in MIS contact are described in detail, for the extraction of the specific contact resistivity ( $\rho _{c}$ ). The physical validity of the proposed model is demonstrated by comparing its calculated $\rho _{c}$ with those obtained in prior experimental studies employing a GaAs substrate (Ti/ZnO/n-GaAs and Ti/TiO2/n-GaAs). The $\rho _{c}$ values for the MIS contacts are also evaluated with various ${D} _{\textsf {it}}$ levels and the interlayers. This model is promising for the development of a comprehensive next-generation MIS contact for the sub-10-nm complementary metal–oxide–semiconductor technology.

The current work reports on the effect of annealing temperatures on the morphology and photoluminescence properties of SrAl 2 O 4 : Eu, Dy thin films on sapphire (0001) substrates fabricated by pulsed laser deposition technique. Scanning electronic microscopy and atomic force microscopy were used to investigate the thickness, surface topography, and the morphology of the films. The film deposited using a higher annealing temperature was packed with a uniform layer of larger particle size grains. In addition, the surface of this film was shown to be relatively rougher than that without annealing treatment. An intense green emission, which is attributed to the 5 d -4 f transition of Eu 2 + was observed at about 520 nm from the films with annealing treatment. The effects of annealing treatment on the morphology, topography, and photoluminescence properties are discussed in detail.

The statement of cash flows is one of the required financial statements of public companies, and thus is required of all accounting majors. After learning the other required financial statements in an introductory financial accounting course and, again, in the first intermediate accounting course, accounting majors learn how to prepare the statement of cash flows in the second or last intermediate accounting course. Most accounting majors find the statement of cash flows significantly more difficult to learn than any other financial statements. Especially, students find it most difficult to understand the indirect method of preparing the statement of cash flows. Preparing the statement of cash flows using the indirect method, students go through the most difficult time, specifically, doing the adjustments that are made to net income to reconcile to cash flows from operating activities.In this paper, presented is a different way to explain the principles of indirect method of preparing the statement of cash flows with a focus on the reconciliation of net income to cash flows from operating activities. Different from the explanations in the textbooks available in the market, the approach presented in the paper is preferred by all the students who were taught the statement of cash flows. Also, pointed out in the paper are a few things that students are easily confused of in learning the statement of cash flows.

The hard X-ray free-electron laser at the Pohang Accelerator Laboratory (PAL-XFEL) in the Republic of Korea achieved saturation of a 0.144 nm free-electron laser beam on 27 November 2016, making it the third hard X-ray free-electron laser in the world, following the demonstrations of the Linac Coherent Light Source (LCLS) and the SPring-8 Angstrom Compact Free Electron Laser (SACLA). The use of electron-beam-based alignment incorporating undulator radiation spectrum analysis has allowed reliable operation of PAL-XFEL with unprecedented temporal stability and dispersion-free orbits. In particular, a timing jitter of just 20 fs for the free-electron laser photon beam is consistently achieved due to the use of a state-of-the-art design of the electron linear accelerator and electron-beam-based alignment. The low timing jitter of the electron beam makes it possible to observe Bi(111) phonon dynamics without the need for timing-jitter correction, indicating that PAL-XFEL will be an extremely useful tool for hard X-ray time-resolved experiments. The Pohang Accelerator Laboratory X-ray Free Electron Laser (PAL-XFEL) in South Korea has now entered operation with a timing jitter of just 20 fs.

We demonstrate the growth of high-quality AlN layers on an AlN nanopillar structure with a patterned SiO2 layer employing horizontal hydride vapor phase epitaxy (HVPE). The use of the AlN nanopillar structure with the patterned SiO2 resulted in improving the crystalline, and overall material properties of the AlN layer. The full width half maximum (FWHM) of peaks corresponding to (002) and (102) reflections of the AlN layer with the nanopillar structure were significantly decreased from 386 and 576 arcsec to 265 and 318 arcsec, respectively, as compared with that of the as-grown AlN layer. The laterally overgrown AlN regions consisted of a continuous well-coalesced layer exhibiting a lower dislocation density than that of the templates used owing to the dislocation blocking and dislocation bending effects. Complementary characterization by transmittance, photoluminescence and Raman spectroscope, indicates further the overall good material properties of the AlN layer grown on the nanopillar structure.

This study investigated the effects of ethanol extract from Gynostemma pentaphyllum (GP-EX) on memory deficits in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-lesioned mouse model of Parkinson's disease (PD) (MPTP-lesioned mice). MPTP (30 mg/kg/day, 5 days)-lesioned mice showed deficits of habit learning memory and spatial memory, which were further aggravated by treatment with L-3,4-dihydroxyphenylalanine (L-DOPA) (25 mg/kg, 21 days). However, treatment with GP-EX (50 mg/kg, 21 days) ameliorated memory deficits in MPTP-lesioned mice treated with L-DOPA (25 mg/kg): GP-EX prevented the decreases in retention latency time in the passive avoidance test and tyrosine hydroxylase-immunopositive cells and dopamine levels in the nigrostriatum. GP-EX also reduced increases in retention transfer latency time of the elevated plus-maze test and expression of N-methyl-D-aspartate (NMDA) receptor and improved decreases in phosphorylation of extracellular signal-regulated kinase (ERK1/2) and cyclic AMP-response element binding protein (CREB) in the hippocampus in the same models. By contrast, L-DOPA treatment (10 mg/kg, 21 days) ameliorated memory deficits in MPTP-lesioned mice, which were further improved by GP-EX treatment. These results suggest that GP-EX ameliorates habit learning memory deficits by activating dopaminergic neurons and spatial memory deficits by modulating NMDA receptor-ERK1/2-CREB system in MPTP-lesioned mice treated with L-DOPA. GP-EX may serve as an adjuvant phytonutrient for memory deficits in PD.

A perfect ohmic contact formation technique for low-resistance source/drain (S/D) contact of germanium (Ge) n-channel metal-oxide-semiconductor field-effect transistors (MOSFETs) is developed. A metal–interlayer–semiconductor (M–I–S) structure with an ultrathin TiO2/GeO2 interlayer stack is introduced into the contact scheme to alleviate Fermi-level pinning (FLP), and reduce the electron Schottky barrier height (SBH). The TiO2 interlayer can alleviate FLP by preventing formation of metal-induced gap states (MIGS) with its very low tunneling resistance and series resistance and can provide very small electron energy barrier at the metal/TiO2 interface. The GeO2 layer can induce further alleviation of FLP by reducing interface state density (Dit) on Ge which is one of main causes of FLP. Moreover, the proposed TiO2/GeO2 stack can minimize interface dipole formation which induces the SBH increase. The M–I–S structure incorporating the TiO2/GeO2 interlayer stack achieves a perfect ohmic characteristic, which ...

We demonstrate the contact resistance reduction for III–V semiconductor-based electrical and optical devices using the interfacial dipole effect of ultrathin double interlayers in a metal-interlayers-semiconductor (M-I-S) structure. An M-I-S structure blocks metal-induced gap states (MIGS) to a sufficient degree to alleviate Fermi level pinning caused by MIGS, resulting in contact resistance reduction. In addition, the ZnO/TiO2 interlayers of an M-I-S structure induce an interfacial dipole effect that produces Schottky barrier height (ΦB) reduction, which reduces the specific contact resistivity (ρc) of the metal/n-type III–V semiconductor contact. As a result, the Ti/ZnO(0.5 nm)/TiO2(0.5 nm)/n-GaAs metal-double interlayers-semiconductor (M-DI-S) structure achieved a ρc of 2.51 × 10–5 Ω·cm2, which exhibited an ∼42 000× reduction and an ∼40× reduction compared to the Ti/n-GaAs metal-semiconductor (M-S) contact and the Ti/TiO2(0.5 nm)/n-GaAs M-I-S structure, respectively. The interfacial dipole at the ZnO/T...

Due to the difficulty of GaN epitaxy growth on Si(001) substrate, GaN-on-Si wafers are generally grown on Si(111) substrates. Because of the poor electrical characteristics of Si(111) orientation, monolithic integration between CMOS ICs and GaN devices cannot be implemented on GaN-on-Si(111) wafers. At this point of view, Si(110) substrate will be an alternative choice for GaN-on-Si epitaxy growth, because it has good atomic arrangement with AlN seed layer and an advantage of excellent hole mobility characteristics over Si(001). We have developed high quality GaN epitaxy growth technique on Si(110) substrate using NH3 MBE and demonstrated normally-off AlGaN/GaN-on-Si(110) metal–oxide–semiconductor-heterojunction field-effect transistors with an OFF-state breakdown voltage of 610 V. The fabricated device exhibited promising characteristics comparable with those achieved on conventional GaN-on-Si(111) wafers.

Wearable pressure sensors capable of sensitive, precise, and continuous measurement of physiological and physical signals have great potential for the monitoring of health status and the early diagnosis of diseases. This work introduces a 3D-printed rigid microbump-integrated liquid metal-based soft pressure sensor (3D-BLiPS) for wearable and health-monitoring applications. Using a 3D-printed master mold based on multimaterial fused deposition modeling, the fabrication of a liquid metal microchannel and the integration of a rigid microbump array above the microchannel are achieved in a one-step, direct process. The microbump array enhances the sensitivity of the pressure sensor (0.158 kPa-1 ) by locally concentrating the deformation of the microchannel with negligible hysteresis and a stable signal response under cyclic loading. The 3D-BLiPS also demonstrates excellent robustness to 10 000 cycles of multidirectional stretching/bending, changes in temperature, and immersion in water. Finally, these characteristics are suitable for a wide range of applications in health monitoring systems, including a wristband for the continuous monitoring of the epidermal pulse rate for cuffless blood pressure estimation and a wireless wearable device for the monitoring of body pressure using a multiple pressure sensor array for the prevention of pressure ulcers.