Plant diseases pose a significant challenge for food production and safety. Therefore, it is indispensable to correctly identify plant diseases for timely intervention to protect crops from massive ...losses. The application of computer vision technology in phytopathology has increased exponentially due to automatic and accurate disease detection capability. However, a deep convolutional neural network (CNN) requires high computational resources, limiting its portability. In this study, a lightweight convolutional neural network was designed by incorporating different attention modules to improve the performance of the models. The models were trained, validated, and tested using tomato leaf disease datasets split into an 8:1:1 ratio. The efficacy of the various attention modules in plant disease classification was compared in terms of the performance and computational complexity of the models. The performance of the models was evaluated using the standard classification accuracy metrics (precision, recall, and F1 score). The results showed that CNN with attention mechanism improved the interclass precision and recall, thus increasing the overall accuracy (>1.1%). Moreover, the lightweight model significantly reduced network parameters (~16 times) and complexity (~23 times) compared to the standard ResNet50 model. However, amongst the proposed lightweight models, the model with attention mechanism nominally increased the network complexity and parameters compared to the model without attention modules, thereby producing better detection accuracy. Although all the attention modules enhanced the performance of CNN, the convolutional block attention module (CBAM) was the best (average accuracy 99.69%), followed by the self-attention (SA) mechanism (average accuracy 99.34%).
This article surveys the recent development of semiconductor memory technologies spanning from the mainstream static random-access memory, dynamic random-access memory, and flash memory toward ...emerging candidates such as resistive, ferroelectric, and magnetic memories. Pathways for future technological innovations are presented.
This study implements a highly uniform 3D vertically stack resistive random‐access memory (VRRAM) with a four‐layer contact hole structure. The fabrication process of a four‐layer VRRAM is ...demonstrated, and its physical and electrical properties are thoroughly examined. X‐ray photoelectron spectroscopy and transmission electron microscopy are employed to analyze the chemical distribution and physical structure of the VRRAM device. Multilevel capability, reliable endurance (>104 cycles), and retention (104 s) are successfully obtained. Synaptic memory plasticity, such as spike time‐dependent plasticity, spike rate‐dependent plasticity, excitatory post‐synaptic current, paired‐pulse facilitation, and long‐term potentiation and depression is presented. Finally, the vector‐matrix multiplication (VMM) operation is conducted on a 4 × 12 VRRAM array, according to the low resistance state ratio. It is ascertained that the accuracy drop, which can occur due to VMM error, can be limited to a decrease of less than 0.44% point. Utilizing the high‐density, multilevel, and biological characteristics of VRRAM, it is possible to implement high‐performance neuromorphic systems that require densely integrated synaptic devices.
3D vertically stack resistive random‐access memory (VRRAM) with a four‐layer structure is fabricated and electrical properties with high uniformity are thoroughly investigated. Multilevel control, reliable endurance, and stable retention are verified. Synaptic plasticity such as spike‐time dependent plasticity, spike rate‐dependent plasticity, excitatory post‐synaptic current, and paired‐pulse facilitation, and long‐term memory are emulated. Finally, the vector‐matrix multiplication operation is demonstrated on a 4 × 12 VRRAM array.
After surgery for ovarian cancer or colorectal cancer, residual tumors are left around. A practical way to treat residual tumors is to destroy them with heat by injecting high-temperature drugs into ...the abdominal cavity. The injected medicinal substances are induced to flow out of the abdominal cavity; then, the spilled drug flows back into the abdominal cavity through feedback. During this process, the heat starts to decrease; thus, the treatment performance reduces. To overcome this problem, this study compares and assesses the temperature needed to maintain the heat for treatment and transmits a command signal to the heat exchanger through a look-up table (LUT). When the temperature decreases during the circulation of medications leaking out of the abdominal cavity, the LUT transmits a control signal (
) to the heat exchanger, which increases or vice versa. However, if the temperature (
) is within the treatment range, the LUT sends a
signal to the heat exchanger. This principle generates a pulse signal for the temperature difference (
) in TC by comparing and determining the temperature (
) of the substance flowing out of the abdominal cavity with the reference temperature (
) through the temperature comparator (TC). At this time, if the signal is 41 °C or less, the LUT generates (heats) a
signal so that the temperature of the heat exchanger can be maintained in the range of 41 °C to 43 °C. If the
is 44 °C or higher, the LUT generates (cools) the T
signal and maintains the temperature of the heat exchanger at 41-43 °C. If the
is maintained at 41-43 °C, the LUT generates a
signal to stop the system performance. At this time, the TC operation performance and
generation process for comparing and determining the signal of
and
for drugs leaking out of the abdominal cavity is very important. It was observed that the faster the response signal, the lower the comparison and judgment error was; therefore, the response signal was confirmed to be 0.209 μs. The proposed method can guarantee rapid/accurate/safe treatment and automatically induce temperature adjustment; thus, it could be applied to the field of surgery.
Background and Aims The efficacy of palliative biliary drainage by using bilateral or unilateral self-expandable metal stents (SEMSs) for a malignant hilar biliary stricture (MHS) remains ...controversial. This prospective, randomized, multicenter study investigated whether bilateral drainage by using SEMSs is superior to unilateral drainage in patients with inoperable MHSs. Methods Patients with inoperable high-grade MHSs who underwent palliative endoscopic insertion of bilateral or unilateral SEMSs were enrolled. The main outcome measurements were the rate of primary reintervention for malfunction after successful placement of SEMSs, stent patency, technical and clinical success rates, adverse events, and survival duration. Results A total of 133 pathology-diagnosed patients were randomized to the bilateral group (n = 67) or the unilateral group (n = 66). The primary technical success rates were 95.5% (64/67) and 100% (66/66) in the bilateral and unilateral groups, respectively ( P = .244). The clinical success rates were 95.3% (61/64) and 84.9% (56/66), respectively ( P = .047). The primary reintervention rates based on the per-protocol analysis were 42.6% (26/61) in the bilateral group and 60.3% (38/63) in the unilateral group ( P = .049). The median cumulative stent patency duration was 252 days in the bilateral group and 139 days in the unilateral group. The risk of stent patency failure was significantly higher in the unilateral group (log-rank test; P < .01). In a multivariate Cox proportional hazard model to assess stent patency, bilateral SEMS placement was a favorable factor (adjusted hazard ratio 0.30, 95% confidence interval, 0.172-0.521; P < .001). Survival probability and late adverse events were not different between the 2 groups. Conclusions Unilateral and bilateral drainage strategies by using SEMSs had similar technical success rates, but bilateral drainage resulted in fewer reinterventions and more durable stent patency in patients with inoperable high-grade MHSs. (Clinical trial registration number: NCT02166970.)
For tumors wherein cancer cells remain in the tissue after colorectal cancer surgery, a hyperthermic anticancer agent is injected into the abdominal cavity to necrotize the remaining cancer cells ...with heat using a hyperthermic intraperitoneal chemotherapy system. However, during circulation, the processing temperature is out of range and the processing result is deteriorated. This paper proposes a look-up table (LUT) module design method that can stably maintain the processing temperature range during circulation via feedback. If the temperature decreases or increases, the LUT transmits a command signal to the heat exchanger to reduce or increase heat input, thereby maintaining the treatment temperature range. The command signal for increasing and decreasing heat input is
and
, respectively. The command signal for the treatment temperature range is
. If drug temperatures below 41 and above 43 °C are input to the LUT, it sends a
or
signal to the heat exchanger to increase or decrease the input heat, respectively. If the drug's temperature is 41-43 °C, the LUT generates a
signal and proceeds with the treatment. The proposed system can automatically control drug temperature using temperature feedback to ensure rapid, accurate, and safe treatment.
The consumption of multimedia content is ubiquitous in modern society. This is made possible by wireless local area networks (W-LAN) or wire service systems. Bandpass filters (BPF) have become very ...popular as they solve certain data transmission limitations allowing users to obtain reliable access to their multimedia content. The BPFs with quarter-wavelength short stubs can achieve performance; however, these BPFs are bulky. In this article, we propose a compact BPF with a T-shaped stepped impedance resonator (SIR) transmission line and a folded SIR structure. The proposed BPF uses a T-shaped SIR connected to a J-inverter structure (transmission line); this T-shaped SIR structure is used to replace the
/4 transmission line seen in conventional stub BPFs. In addition, a folded SIR is added to the short stubs seen in conventional stub BPFs. This approach allows us to significantly reduce the size of the BPF. The advantage of a BPF is its very small size, low insertion loss, and wide bandwidth. The overall size of the new BPF is 2.44 mm × 1.49 mm (0.068
× 0.059
). The proposed BPF can be mass produced using semiconductors due to its planar structure. This design has the potential to be widely used in various areas including military, medical, and industrial systems.
Recently, various memory devices have been actively studied as suitable candidates for synaptic devices, which are important memory and computing units in neuromorphic systems. One of the ways to ...manage these devices is off-chip training, where it is essential to transfer the pretrained weights accurately. Previous studies, however, have a few limitations, such as a lack of consideration of program errors that occur during the transfer process. Although the smaller the program error, the higher the accuracy, the corresponding increase in the program time must be considered. To evaluate the practical applicability, we fabricated Al 2 O 3 /TiO x -based resistive random access memory (RRAM) and investigated the effect of program errors on program time and system degradation. It was confirmed that for smaller program errors, the program time was exponentially longer. Furthermore, we examined the effect of variation with respect to the number of quantized weight states (<inline-formula> <tex-math notation="LaTeX">{N}_{state} </tex-math></inline-formula>) through system-level simulation. We observed that the optimized <inline-formula> <tex-math notation="LaTeX">{N}_{state} </tex-math></inline-formula> varies depending on whether the program error is small or large. This result is meaningful as it experimentally shows the tradeoff between the program error, program time, and system performance. We expect it to be useful in the development of neuromorphic systems.
Although vertical configurations for high-density storage require challenging process steps, such as etching high aspect ratios and atomic layer deposition (ALD), they are more affordable with a ...relatively simple lithography process and have been employed in many studies. Herein, the potential of memristors with CMOS-compatible 3D vertical stacked structures of Pt/Ti/HfO
x
/TiN-NCs/HfO
x
/TiN is examined for use in neuromorphic systems. The electrical characteristics (including
I
-
V
properties, retention, and endurance) were investigated for both planar single cells and vertical resistive random-access memory (VRRAM) cells at each layer, demonstrating their outstanding non-volatile memory capabilities. In addition, various synaptic functions (including potentiation and depression) under different pulse schemes, excitatory postsynaptic current (EPSC), and spike-timing-dependent plasticity (STDP) were investigated. In pattern recognition simulations, an improved recognition rate was achieved by the linearly changing conductance, which was enhanced by the incremental pulse scheme. The achieved results demonstrated the feasibility of employing VRRAM with TiN nanocrystals in neuromorphic systems that resemble the human brain.
Synaptic plasticity and non-volatile memory behaviors are demonstrated in TiN-nanocrystal-embedded 3D vertical structure-type memristor synapses to realize neuromorphic systems.
We developed W/HfO2/TiN vertical resistive random-access memory (VRRAM) for neuromorphic computing. First, basic electrical properties, such as current–voltage curves, retention, and endurance, were ...determined. To examine the conduction mechanism, a device with a large switching area was fabricated, and its current level and that of the VRRAM were compared. Moreover, we analyzed the current behavior relative to the ambient temperature. Subsequently, the number of states upon potentiation and depression was linearly converted via conductance modulation due to an applied pulse. The practicality of the device was assessed using a convolutional neural network. Finally, 16-state reservoir computing was combined with multilevel characteristics to implement 8-bit reservoir computing with 256 states. We verified that in terms of time and power consumption, 8-bit reservoir computing is more efficient than 4-bit reservoir computing. Hence, we concluded that the W/HfO2/TiN VRRAM cell is a promising volatile memory device.
Display omitted
•3-dimensional VRRAM structure was fabricated for high-density synapse.•High-performance memory with low-power and self-rectifying characteristics is implemented.•99.15 % accuracy for MNIST is achieved in CNN.•Short-term memory characteristics are demonstrated.•Reservoir computing with 256 states was demonstrated for more energy efficiency.
PDF
