The pursuit of sub-1-nm field-effect transistor (FET) channels within 3D semiconducting crystals faces challenges due to diminished gate electrostatics and increased charge carrier scattering. 2D semiconductors, exemplified by transition metal dichalcogenides, provide a promising alternative. However, the non-idealities, such as excess low-frequency noise (LFN) in 2D FETs, present substantial hurdles to their realization and commercialization.
View Article and Find Full Text PDFMicromachines (Basel)
October 2022
Deep learning produces a remarkable performance in various applications such as image classification and speech recognition. However, state-of-the-art deep neural networks require a large number of weights and enormous computation power, which results in a bottleneck of efficiency for edge-device applications. To resolve these problems, deep spiking neural networks (DSNNs) have been proposed, given the specialized synapse and neuron hardware.
View Article and Find Full Text PDFFront Neurosci
September 2020
A novel operation scheme is proposed for high-density and highly robust neuromorphic computing based on NAND flash memory architecture. Analog input is represented with time-encoded input pulse by pulse width modulation (PWM) circuit, and 4-bit synaptic weight is represented with adjustable conductance of NAND cells. Pulse width modulation scheme for analog input value and proposed operation scheme is suitably applicable to the conventional NAND flash architecture to implement a neuromorphic system without additional change of memory architecture.
View Article and Find Full Text PDFHardware-based spiking neural networks (SNNs) inspired by a biological nervous system are regarded as an innovative computing system with very low power consumption and massively parallel operation. To train SNNs with supervision, we propose an efficient on-chip training scheme approximating backpropagation algorithm suitable for hardware implementation. We show that the accuracy of the proposed scheme for SNNs is close to that of conventional artificial neural networks (ANNs) by using the stochastic characteristics of neurons.
View Article and Find Full Text PDFDeep learning represents state-of-the-art results in various machine learning tasks, but for applications that require real-time inference, the high computational cost of deep neural networks becomes a bottleneck for the efficiency. To overcome the high computational cost of deep neural networks, spiking neural networks (SNN) have been proposed. Herein, we propose a hardware implementation of the SNN with gated Schottky diodes as synaptic devices.
View Article and Find Full Text PDFNAND flash memory which is mature technology has great advantage in high density and great storage capacity per chip because cells are connected in series between a bit-line and a source-line. Therefore, NAND flash cell can be used as a synaptic device which is very useful for a high-density synaptic array. In this paper, the effect of the word-line bias on the linearity of multi-level conductance steps of the NAND flash cell is investigated.
View Article and Find Full Text PDFA gated Schottky diode with a field-plate structure is proposed and investigated as a new low-power synaptic device to suppress the forward current of the Schottky diode. In a hardware-based neural network, unwanted forward current can flow through gated Schottky diode-type synaptic devices during integration operations, possibly causing a malfunction of the neural network and increasing the power consumption. By adopting a field-plate structure, a virtual junction to suppress the forward current of the Schottky diode is formed in the poly-Si active layer.
View Article and Find Full Text PDFIn this paper, we reviewed the recent trends on neuromorphic computing using emerging memory technologies. Two representative learning algorithms used to implement a hardware-based neural network are described as a bio-inspired learning algorithm and software-based learning algorithm, in particular back-propagation. The requirements of the synaptic device to apply each algorithm were analyzed.
View Article and Find Full Text PDFThis work investigates the intrinsic characteristics of multilayer WSe field effect transistors (FETs) by analysing Pulsed - (PIV) and DC characteristics measured at various temperatures. In DC measurement, unwanted charge trapping due to the gate bias stress results in - curves different from the intrinsic characteristic. However, PIV reduces the effect of gate bias stress so that intrinsic characteristic of WSe FETs is obtained.
View Article and Find Full Text PDFBackground: Treatment of multilevel cervical spondylotic myelopathy/radiculopathy is a matter of debate, more so in elderly patients due to compromised physiology. We evaluated the clinical and radiological results of cervical fusion, using wedge-shaped tricortical autologous iliac graft and Orion plate for three-level anterior cervical discectomy in elderly patients.
Materials And Methods: Twelve elderly patients with mean age of 69.
Study findings have been inconsistent in confirming advantages for mobile-bearing compared with fixed-bearing prostheses for total knee arthroplasty. Therefore, we did meta-analysis of trials comparing outcomes from using the 2 different designs. Of 5670 citations identified for screening, 10 trials reporting 620 participants (906 knees) at final follow-up were eligible for data extraction and meta-analysis.
View Article and Find Full Text PDFBackground: In impingment syndrome with associated stiff shoulder the general protocol of management is to conservatively treat the stiff shoulder followed by operative treatment of the impingement syndrome. This consecutive prospective study was carried out to evaluate the functional outcome of surgical management for impingement syndrome associated with stiff shoulder and to compare the results with surgical management of impingement syndrome alone.
Materials And Methods: We evaluated a total of 100 patients with impingement syndrome, consisting of 76 patients with impingement syndrome alone (Group A) and 24 patients of stiff shoulder associated with impingement syndrome (Group B).
J Shoulder Elbow Surg
February 2008
The purpose of this study was to evaluate the strength of the shoulder before and after the impingement test. This study included 153 cases of impingement syndrome, 20 cases of partial-thickness rotator cuff tear, and 60 cases of full-thickness rotator cuff tear. We divided each of the groups into 2 subgroups according to the mean percentage decrease in pain to evaluate the correlation between pain and muscle weakness.
View Article and Find Full Text PDFBecause the use of arthroscopy has increased recently for the treatment of elbow lesions, reports of complications have become more common. Nerve injury after arthroscopic anterior capsular release is an extremely rare complication, with 4 reported cases worldwide. We usually use a sharp-tipped electrocautery device with a 0.
View Article and Find Full Text PDFTo study the bone age delay patterns in different stages of Perthes disease, 140 hand and corresponding hip radiographs in 83 patients were assessed. In the hand radiographs, the radius, ulna, metacarpals and phalanges (RUS) and carpal bone ages were calculated using the Tanner and Whitehouse 3 method and the Greulich and Pyle (G and P) bone age was assessed using the G and P atlas. From corresponding hip radiographs, the modified Elizabethtown stage was assessed.
View Article and Find Full Text PDFGenetic diversity of 18 Acanthamoeba isolates from ocean sediments was evaluated by comparing mitochondrial (mt) DNA RFLP, 18S rDNA sequences and by examining their cytopathic effects on human corneal epithelial cells versus reference strains. All isolates belonged to morphologic group II. Total of 16 restriction phenotypes of mtDNA from 18 isolates demonstrated the genetic diversity of Acanthamoeba in ocean sediments.
View Article and Find Full Text PDFBioorg Med Chem Lett
December 2005
The new catecholic xanthone, 1,3,7-trihydroxy-4-(1,1-dimethyl-2-propenyl)-5,6-(2,2-dimethylchromeno)-xanthone (1), was isolated from the root bark of Cudrania tricuspidata together with seven known xanthones. The structures were fully characterized by analysis of physical and spectral (UV, IR, mass, and NMR) data. Relationships between the structural characteristics of xanthones and their antioxidant activities (DPPH, superoxide, and hydroxyl radical) were studied.
View Article and Find Full Text PDFBackground: In neuromuscular diseases, limb lengthening and foot deformity correction are associated with a high risk of complications associated with distraction callus and joint contracture. We have found no published articles of tibial lengthening and concomitant foot deformity correction using the Ilizarov method or traditional methods. To compare result of gradual distraction with triple arthrodesis for foot deformity combined with tibial lengthening, we investigated healing index and complications of two methods.
View Article and Find Full Text PDFThis study was designed to establish a more effective and safe culture system for adoptive immunotherapy by investigating the use of homologous cord blood plasma (HCBP) instead of fetal bovine serum (FBS), which has various limitations including ethical problems for the ex vivo expansion of human umbilical T lymphocytes. Fresh human umbilical mononuclear cell fractions were isolated by Ficoll-Hypaque density centrifugation. Nonadherent mononuclear cell fractions were cultured with anti-CD3 antibody (5 microg/ml), IL-2 (175 U/ml), and either 10% FBS or 10% HCBP.
View Article and Find Full Text PDFThe authors analyzed the results and complications of metatarsal lengthening in short first metatarsals by distraction osteogenesis. There were 13 first metatarsal lengthenings in eight patients. Mean age was 18.
View Article and Find Full Text PDFPurpose: This study was to examine the effects of Taping therapy on the deformed angle of the foot and pain in hallux valgus patients.
Method: The subjects were 24 feet from 15 patients who were diagnosed withhallus valgus at the orthopedic department of K University Hospital in Seoul. Taping therapy was conducted 15 times overall during a four-week period.
This study investigated the effects of calcium sulfate powder injection in a rabbit tibial distraction model. There was one experimental group and two control groups. The calcium sulfate powder, suspended in carboxymethylcellulose (CMC) medium, was injected into the distracted tissue in the experimental rabbit group, whereas only CMC medium was injected into the one control group.
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