Gm Values Research Articles

Gate modulation of barrier height of unipolar vertically stacked monolayer ReS2/MoS2 heterojunction

This study investigates vertically stacked CVD grown ReS2/MoS2 unipolar heterostructure device as Field Effect Transistor (FET) device wherein ReS2 on top acts as drain and MoS2 at bottom acts as source. The electrical measurements of ReS2/MoS2 FET device were carried out and variation in Ids (drain current) Vs Vds (drain voltage) for different Vgs (gate voltage) revealing the n-type device characteristics. Furthermore, the threshold voltage was calculated at the gate bias voltage corresponding to maximum transconductance (gm) value which is ~ 12 V. The mobility of the proposed ReS2/MoS2 heterojunction FET device was calculated as 60.97 cm2 V−1 s−1. The band structure of the fabricated vDW heterostructure was extracted utilizing ultraviolet photoelectron spectroscopy and the UV–visible spectroscopy revealing the formation of 2D electron gas (2DEG) at the ReS2/MoS2 interface which explains the high carrier mobility of the fabricated FET. The field effect behavior is studied by the modulation of the barrier height across heterojunction and detailed explanation is presented in terms of the charge transport across the heterojunction.

Process-induced stress tuning to improve linearity performance in AlGaN/GaN HEMTs with SiNx passivation

Strain engineering has proven to be a useful technique for enhancing the performance of many modern-day transistors. Stress engineering can also have a non-trivial effect on the performance of GaN HEMTs, which are devices of choice for high-power, high-frequency microwave applications. Process-induced stress can have a significant effect on AlGaN/GaN HEMT electrical characteristics in addition to the growth-induced strain present due to lattice constant mismatch between device layers. Understanding the true impact of process-induced strain on AlGaN/GaN HEMT microwave performance is highly necessary. This is especially the case for nonlinearity effects which affect the high-frequency performance of the device. To the best of our knowledge, there is no systematic report on the effect of nitride passivation-induced stress on AlGaN/GaN HEMT device linearity. This work uses a systematic combination of TCAD process simulation and device simulation to quantify the effect of process-induced stress on the device’s linearity. This work demonstrates that nonlinearity effects can be minimized through proper tuning of stress by varying design-dependent parameters such as the nitride layer thickness. The effect of stress on highly important linearity parameters of the device like gm, gm2, gm3, VIP2, VIP3, IIP3 and IMD3 is investigated in detail. Comparing the compressive-stress device to the no-stress and tensile-stress devices, we conclude that the compressive stress device has a max gm2 value that is 61% and 71% higher respectively. The max gm3 for compressive stress is 0.13 A V−3 whereas those for no-stress and tensile stress are 0.067 A V−3 and 0.045 A V−3 respectively. However, the voltage-variations of VIP2, and the VIP3 parameters which are derived from these gm values shows that the compressive stress case can help achieve overall better device linearity by stress tuning. This work also studies how the effect of process-induced stress on device linearity varies with the crucial gate length parameter.

Analysis of 10 nm Strained Channel Double Gate Ultra-Thin Body Junctionless MOSFET

Numerous technological improvements and innovative device architecture have been thoroughly explored and tested for continually downscaling components without compromising on performance metrics. The most simplified structure that has been introduced so far is the junctionless transistors. Junctionless transistors have been shown to exhibit excellent electrical behavior with improved short-channel effects. The major challenges with junctionless based transistors are low ON-current drive and high device variability. Strain engineering has been proven to be a viable option to enhance the ON-current performance of the MOSFET. This work incorporated strained silicon in double gate junctionless ultra-thin body MOSFET (DG-JL UTB MOSFET), which enhanced the mobility of the charge carrier as a result of which ON current behavior improves. The simulated results show 30.2% enhancement in the ON-current, subthreshold current reduced to nearly half, ION/IOFF ratio is increased by three times, and Drain-induced barrier lowering (DIBL) reduced by 25.1% with respect to unstrained device. Analog performance metrics are also calculated for the considered device design. With strained silicon, the value of Gm is increased by more than 30% and transconductance generation factor (TGF) is increased by 28.27% in reference with the unstrained device.

A single-IC realizable, electronically tunable, OTA-based full-wave rectifier with simultaneous positive and negative outputs

A new voltage-mode full-wave rectifier (FWR) is proposed in this study. The proposed FWR employs two single-output operational transconductance amplifiers (OTAs), four diodes, and two grounded resistors. It has high input impedance and does not need any extra bias current or voltage sources. It simultaneously provides positive and negative rectified output signals over separate output terminals. The amplitudes of both output signals can be adjusted by varying the resistor values or the transconductance (gm) values of the OTAs. It does not include any floating passive elements, so it is suitable for integrated circuit (IC) implementations. The proposed FWR can be implemented by using a single commercially available IC such as LM13700. However, the proposed FWR has a single matching condition for gm values of the OTAs. Several simulation and experimental test results are added to confirm the theory and show the operability of the proposed circuit.

Optimizing electrical and thermal performance in AlGaN/GaN HEMT devices using dual‐metal gate technology

AbstractThe investigation of aluminum gallium nitride/gallium nitride high electron mobility transistor (AlGaN/GaN HEMT) devices with a dual‐metal gate (DMG) structure encompasses both electrical and thermal characteristics. As efforts to enhance heat dissipation progress, there is a concurrent exploration of novel semiconductor materials boasting high thermal conductivity, like boron arsenide and phosphide. Combining these materials into a model and measuring their interface achieves efficient energy transport. Minimizing the self‐heating impact in AlGaN/GaN HEMTs is essential for enhancing device efficiency. This research exposes the heterogenous combination of boron arsenide and phosphide cooling substrates with metals, GaN semiconductors and HEMT. In this research, the autoencoder deep neural network techniques in GaN HEMT for self‐heat reduction is driven by the ability to effectively analyze and model the thermal behavior of the device. Autoencoders learn complex relationships within temperature data and identify patterns associated with self‐heating. By leveraging these learned representations, the deep neural network optimizes control strategies to mitigate self‐heating effects in GaN HEMT devices, ultimately contributing to improved thermal management and enhanced overall performance. In this research, the use of genetic algorithms in GaN HEMT aims to optimize device parameters systematically, to minimize self‐heating effects and enhance overall thermal performance. The structure also enhances electron mobility within the channel. Results show DMG structures, exhibiting higher saturation output currents and transconductance despite self‐heating. The DMG exhibits a maximum gm value of 0.164 S/mm, which is 10% higher significantly enhancing GaN‐based HEMTs for improved reliability and efficiency in various applications.

The effect of antifungal treatments on bronchoalveolar lavage galactomannan for the diagnosis of invasive fungal infections in patients with hematological malignancy: Single-center experience

Background Invasive fungal infections (IFI) mainly caused by aspergillus species are one of the leading causes of death in patients undergoing immunosuppressive therapy for hematological malignancies. The presence of galactomannan in bronchoalveolar lavage fluid (BAL GM) is an important diagnostic marker. Some of the factors affecting the BAL GM are still unknown. Antifungal treatment administered before or after BAL also affect BAL GM results. Methods To investigate the effect of BAL GM timing on the diagnosis of IFE, 100 patients receiving immunosuppressive therapy with hematological malignancy at the Uludağ University Faculty of Medicine, Hematology Department, and underwent BAL over a 3-year period with the suspicion of IFE as well as 127 BAL procedures of these patients were examined. Results There were 70 patients who started antifungal therapy before BAL and 30 patients who did not. BAL GM was found positive in 33 (47.1%) of the 70 patients who received antifungal therapy compared to 22 (73.3%) of the 30 patients who did not receive antifungal therapy. There was a significant difference between the two groups in terms of BAL GM positivity (p = 0.016). Subsequently, 127 BAL procedures of these 100 patients were evaluated. When the second, third, and subsequent BAL procedures of the same patients were included in the study, BAL GM was positive in 41 (46.6%) of the 88 procedures in patients who received treatment before BAL and in 25 (64.1%) of the 39 procedures in patients who did not receive treatment before BAL. The rate of BAL GM positivity did not differ between groups (p = 0.068). Conclusions The balance between reducing the risk by initiating early antifungal therapy and maximizing the diagnostic value of BAL GM should be evaluated individually for each patient.

Dual Engine Boosts Organic Photoelectrochemical Transistor for Enhanced Modulation and Bioanalysis.

Organic photoelectrochemical transistor (OPECT) has shown substantial potential in the development of next-generation bioanalysis yet is limited by the either-or situation between the photoelectrode types and the channel types. Inspired by the dual-photoelectrode systems, we propose a new architecture of dual-engine OPECT for enhanced signal modulation and its biosensing application. Exemplified by incorporating the CdS/Bi2S3 photoanode and Cu2O photocathode within the gate-source circuit of Ag/AgCl-gated poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) channel, the device shows enhanced modulation capability and larger transconductance (gm) against the single-photoelectrode ones. Moreover, the light irritation upon the device effectively shifts the peak value of gm to zero gate voltage without degradation and generates larger current steps that are advantageous for the sensitive bioanalysis. Based on the as-developed dual-photoelectrode OPECT, target-mediated recycling and etching reactions are designed upon the CdS/Bi2S3, which could result in dual signal amplification and realize the sensitive microRNA-155 biodetection with a linear range from 1 fM to 100 pM and a lower detection limit of 0.12 fM.

Diagnosis of invasive pulmonary fungal infections by a real-time panfungal PCR assay in non-neutropenic patients.

This study explored the utility of quantitative real-time panfungal PCR assay in diagnosing invasive pulmonary fungal diseases (IPFD) in non-neutropenic patients. Panfungal PCR assay was performed on respiratory tract specimens from patients whose clinical signs could not exclude fungal infection. At the same time, the samples were subjected to bacterial and fungal culture, microscopic examination and galactomannan antigen (GM) test in order to find the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of the 4 diagnostic methods in proven and probable cases. 518 specimens were collected while 63 respiratory tract specimens tested by PCR had positive results. According to diagnostic criteria, 40 patients were diagnosed with IPFD, with 12 proven, 20 probable and 8 possible cases. Among these, 33 patients of PCR results were positive, most of which were from BALF samples (44.12%). 23 cases were caused by Aspergillus species, with Aspergillus fumigatus was the major cause. Other Aspergillus species, including Aspergillus flavus, Aspergillus terreus and Aspergillus nidulans were found in 1 sample respectively. Candida species were found in 5 samples, Pneumocystis jeroveci pneumonia (PJP) in 4 samples and Mucormycosis in 1 sample. An analysis of proven/probable diagnosis showed a sensitivity of 78.13%, specificity of 92.18%, PPV of 39.68% and NPV of 98.46% for PCR and 50%, 85.27%, 35.7%, 95.65% for GM test respectively. The Ct value difference between proven/probable and possible cases had no statistical significance (P = .824). Fungal culture showed a sensitivity of 17.5% while microscopic examination sensitivity of 32.5%. Through stratified analysis, no apparent correlation was found between the Ct value of the PCR assay and GM value (r: 0.223, P = .294). But a conjunction of the 2 tests raised the PPV of Aspergillus to 90%. As shown in this study, the panfungal RT-PCR assay has high sensitivity and consistency with serological test and culture. Its high PPV in the detection of Aspergillus and PJP were also evident.

(Invited) BEOL-Compatible Oxide Semiconductor Logic and Memory Devices

3D monolithic integration of logic and memory devices has emerged as one of the key enablers for next-generation electronic devices to address the ever-increasing demand for higher integration density, better performance and energy efficiency. BEOL-compatible oxide semiconductors show great potential to revolutionize the field thanks to their unique properties [1].We present our recent advancement related to BEOL-compatible oxide semiconductors for logic and memory applications. The digital-etch-enabled nanowire transistors and α-IGZO-based eDRAM will first be discussed, followed by the ferroelectric (FE) memories with high performance and novel structures utilizing α-IGZO or ALD-deposited ZnO as the channel.Ultra-scaled amorphous IGZO (α-IGZO) nanowire field-effect transistors (NW-FETs) hold great potential for applications demanding high performance and integration density. To realize the fabrication of high-quality and aggressively-scaled nanowire structures, a novel digital etching method for amorphous α-IGZO materials has been proposed and demonstrated [2]. Confirmed by the SEM images of an α-IGZO nanowire before and after digital etching, a notable nanowire width W NW reduction can be observed. We have the thinnest α-IGZO nanowire achieved by the digital etching with a W NW of approximately 20 nm. By further developing the transistor upon the nanowire, the α-IGZO NW-FET attains a good subthreshold swing (SS) of 80 mV/decade and a high peak extrinsic transconductance (G m, ext) of 612 μS/μm at V DS of 2 V (456 μS/μm at V DS = 1 V). Compared to the previous studies, our IGZO NW-FET achieves one of the highest peak G m values among all IGZO-based FETs.Besides the BEOL compatibility and high on-current, ultra-low subthreshold leakage makes α-IGZO FETs extremely promising for eDRAM. We further investigated the potential of α-IGZO eDRAM by developing the charge-domain compute-in-memory (CiM) [3]. Experiments have demonstrated small SS, large on-state current, and long-time charge retention with our dedicated 4T1C memory cell. With differential cell structure, an even higher tolerance for charge loss can be attained. With experiment-calibrated benchmarking in the VGG-8 network for CIFAR-10 image classification tasks, 2092 TOPS/W power efficiency for the CiM core can be expected, outperforming the prior TFT and CMOS-based CiM approaches, exhibiting significant advantages for ultra-low-power applications.The integration of doped-HfO2 FE material and oxide semiconductor, both BEOL-compatible with large-scale and cost-effective deposition, presents a promising avenue for advancing data storage in the future. We have developed the high-performance α-IGZO Fe-FET with a metal-ferroelectric-metal-oxide-semiconductor (MFMIS) structure as well as the Fe TCAM [4]. The α-IGZO Fe-FET achieves a large memory window of ~3 V with high reliability, while the Fe TCAM reduces the transistor number from 16 to 2 compared to the traditional SRAM-based one. Besides α-IGZO, we believe that ALD-based oxide semiconductors featuring high controllability of film thickness and conformal coverage of the 3D structures can create new opportunities for novel device structure and integration. The fin-gate ZnO Fe-FET stands for a great example while not only outstanding device performance but also suppressed device-to-device variation due to the unique structure have been demonstrated, holding tremendous promise for high-density 3D integration [5]. Acknowledgments: This work is supported by Singapore Ministry of Education (Tier 2: MOE2018-T2-2-154, Tier 1: R-263-000-D65-114).

(Invited) Characteristics of GaN/High-k Capacitors Under Positive Bias Stress

Vertical GaN-based trench gate metal-oxide-semiconductor field-effect transistors (MOSFETs) have been widely investigated to suppress leakage currents for applications associated with high power and high frequency. Various materials with high dielectric constant (High-k) such as Al2O3, HfO2, AlSiO x , HfSiO x , and HfAlOx have been studied as gate insulator to obtain high gm value of GaN MOSFET [1-6]. The structure of High-k gate insulator and interface between GaN and High-k is well known to affect characteristics of GaN MOS capacitor. An amorphous HfAlOx film could be fabricated by forming (HfO2)/(Al2O3) nanolaminate films via plasma-enhanced atomic layer deposition and post-deposition annealing at 800°C. Al2O3 and HfAlOx gate insulators with an amorphous structure found to exhibit superior fundamental electrical properties including no frequency dispersion, a high breakdown voltage and a low interface state density [3,5,6]. However, reliability characteristics under high voltage sweep and positive bias stress (PBS) conditions are not currently well understood.In this paper, we investigate flatband voltage (Vfb) shift of the Al2O3 and HfAlOx capacitors by varying effective electric field (Eeff) from Vfb under PBS. We also compare Vfb shift behavior among Al2O3, HfAlOx and reported High-k gate insulators.Here, to understand influence of the thermal budget at 800°C on electrical property, two n-GaN/Al2O3(10nm)/Pt MOS capacitors were prepared: One was fabricated by thermal budget at 300°C (AlO). The other was fabricated by the same capacitor fabrication process, with the GaN substrate annealed at 800°C before Al2O3 film deposition (Pre800C-AlO). To examine interface properties of the n-GaN/HfAlOx, n-GaN/interfacial layer (IL)/HfAlOx(10nm)/Pt capacitor with a 0.5nm-thick-Al2O3-IL (AlO/HfAlO) and a 0.5nm-thick-HfO2-IL (HfO/HfAlO) and without IL (HfAlO) were prepared.All High-k gate insulators had an amorphous structure. The k-values of Al2O3 and HfAlOx gate insulators estimated from C-V measurement were 8 and 17.2, respectively [3,6]. All capacitors exhibited the smooth J-Eeff properties due to an amorphous structure regardless of the 800°C pre-annealing of the GaN substrate and IL of HfAlOx case. All capacitors also exhibited no frequency dispersion in the range of 1k-1MHz. However, the Pre800C-AlO capacitor showed a large hump due to the electrical defects in the C-V curve. The Vfb shift behavior of the capacitor was examined by varing Eeff from Vfb of PBS. The Eeff was estimated from the applied voltage divided by capacitanc equivalent thickness. The Eeff from Vfb of Al2O3 and HfAlOx capacitors were varied from 4.1-8.7 and 6.5-15.4MVcm-1, respectively. The stress time was varied from 0 to 300s . The sweep voltage range of C-V measurement for obtaining Vfb in each stress time was always applied smaller than the PBS voltage. The positive Vfb shift was observed in all capacitors after PBS, indicating the presence of some electron trapping sites. The positive Vfb increased siginificantly up to a stress time of 10s, gradually increased up to 200s, and saturated above 200s in all Eeff from Vfb regions. The positive Vfb value of all capacitors reached to around 0.2V when the Eeff from Vfb was applied to 6.5MVcm-1 at 300s. Above 6.5MVcm-1, different Vfb shift profiles were observed for two Al2O3 and three HfAlOx capacitors. The positive Vfb value of the Al2O3 capacitors increased drastically to 0.5V as the Eeff from Vfb increased from 6.5 to 8.7MVcm-1. Furthermore, the Pre800C-AlO capacitor became larger Vfb shift than the AlO capacitor because the Pre800C-AlO capacitor is due to the introduction of some defects on the GaN surface by pre-annealing at 800°C. On the other hand, for the HfAlO, AlO/HfAlO and HfO/HfAlO capacitors, the positive Vfb shift value was suppressed to 0.3V even when the Eeff from Vfb was applied to 15.4 MVcm-1. Furthermore the Vfb shift showed similar behavior regardless of Al2O3- and HfO2-IL. Based on these experimental data, we conclude that the HfAlOx capacitors have a high reliability under PBS condition.This work was supported by the MEXT Program for Creation of Innovative Core Technology for Power Electronics Grant Number JPJ009777. This work was supported in part by JSPS KAKENHI Grant No. JP20H02189.[1] J. T. Asubar et al., J. Appl. Phys. 129, 121102 (2021). [2] Y. Ando et al., Appl. Phys. Lett. 117, 102102 (2020). [3] K. Yuge et al., Semicond. Sci. Technol. 34, 034001 (2019). [4] D. Kikuta et al., Appl. Phys. Express 13, 026504 (2020). [5] T. Nabatame et al., Appl. Phys. Express 12, 011009 (2019). [6] T. Nabatame et al., ECS Trans. 104 113 (2021).

Quality factor and digital inverter performance in gate underlap and overlap DMG FinFETs

This paper presents a comparative 3D simulation study of Quality factor among Gate Underlap and Overlap techniques in both Si and Ge Dual Material Gate (DMG) FinFETs using the Sentaurus TCAD tool. The results of both the techniques are carefully examined and compared with Conventional DMG FinFET to analyze the performances of these devices. The effect of gate overlap/underlap techniques on threshold voltage (Vth), ION/IOFF ratio, drain induced barrier lowering (DIBL), transconductance (gm), subthreshold swing (SS), and Quality factor (Q) are investigated. It is found that Ge DMG FinFETs have higher gm and quality factor values as compared to Si DMG FinFETs. The prospects of these techniques in low-power digital applications have been performed by implementing complementary Si DMG FinFET based inverter circuit. We have extracted the average delay and noise margin, where the overlap structure performs better such as high current gain and no overshoot/undershoot peaks in the transient characteristics.

Potential of electrolyte-gated transistors for anionic molecule detection: proof of concept using dye solution

The use of electrolyte-gated transistors (EGTs) as sensors can be an advantageous alternative for the detection of anionic molecules due to their capability to detect various ions in solution. In this study, we explore the potential of EGTs as analytical tools for detecting anionic molecules, utilizing a copper phthalocyanine-3,4′,4″,4‴-tetrasulfonic acid tetrasodium salt (CuTsPc) solution as a proof of concept. The results demonstrate the EGT’s capacity in detecting CuTsPc in an aqueous solution, which molecule dissociates into sodium ions (Na+) and CuPc(SO3 −)4 ions, leading to high ionic conductivity and the formation of electrical double layers (EDLs). Varying the concentration of the molecule induced alterations in the EDLs, exhibiting good linearity and sensitivity in the transconductance, and a detection limit of 6.0 × 10−8 mol l−1. Transistors employing the CuTsPc solution as electrolyte operated at low voltages and performed better than water-gated transistors (W-GTs). The transconductance (gm ) value for EGTs using CuTsPc solution reached 1.93 mS, while for W-GTs it was around 0.10 mS. Thus, the CuTsPc solution not only serves as a target-molecule in sensor measurements, but also demonstrates potential as an electrolyte in EGTs, thereby assuming a dual role within the device. The main advantage of the EGTs as an analytical tool is their use as a multiparameter device that enables the detection of the analytes using different phenomena that occur at the EDLs interface and which, consequently, changes the device’s performance.

Investigation of the Effect of Different SiNx Thicknesses on the Characteristics of AlGaN/GaN High-Electron-Mobility Transistors in Ka-Band

The effect of different SiNx thicknesses on the performance of AlGaN/GaN high-electron-mobility transistors (HEMTs) was investigated in this paper. The current, transconductance (Gm), cut-off frequency (fT), maximum oscillation frequency (fmax), power performance, and output third-order intercept point (OIP3) of devices with three different SiNx thicknesses (150 nm, 200 nm, and 250 nm) were measured and analyzed. The DC measurements revealed an increase in both the drain-source current (IDS) and Gm values of the device with increasing SiNx thickness. The S-parameter measurement results show that devices with a higher SiNx thickness exhibit improved fT and fmax. Regarding power performance, thicker SiNx devices also improve the output power density (Pout) and power-added efficiency (PAE) in the Ka-band. In addition, the two-tone measurement results at 28 GHz show that the OIP3 increased from 35.60 dBm to 40.87 dBm as the SiNx thickness increased from 150 nm to 250 nm. The device’s characteristics improved by appropriately increasing the SiNx thickness.

TRANSPORTATION ROUTE SELECTION ANALYSIS OF THE TUBAN-BOJONEGORO ROUTE DUE TO THE DAMAGE OF THE GLENDENG BRIDGE

A bridge is a structure built to connect two or more points separated by a river, valley, ravine, or highway. Damage to a bridge can cause several adverse impacts, including: traffic accidents, transportation disruptions, economic disruptions, social disruptions, environmental damage, financial losses. The traffic flow diversion through the three-way intersection before the Glendeng Bridge to the Kaliketek Bridge is intended for small vehicles while large vehicles are diverted to the Soko-Ponco highway. The 4 km traffic diversion route is quite far for the local community. Apart from the Kaliketek Bridge alternative, people can also use boat crossings as access between cities. But the boat can only be used by two wheels. Therefore this study aims to determine the effectiveness of alternatives between Kaliketek routes and boat crossings. The purpose of this research is to analyze which path is more effective for 2-wheeled riders between the Kaliketek and Ferry Boat Routes and to find out the more effective path between the two. The method used in making decisions and selecting solutions is to use the AHP method. The results of this study include: Alternative value analysis is carried out by calculating pairwise comparisons starting from alternatives, sub-criteria and criteria. In this study, the calculated value of the sub-criteria was obtained with the GM value of each sub-criteria, namely time 0.93, convenience 0.88, cost 0.00 and safety 0.00. While the Vp value is obtained by dividing the GM value by the total GM value. And from this calculation the value of Vp time is 0.51, comfort 0.49, cost 0.00 and security 0.00. Then calculate the value of the evaluation criteria for the sub-criteria and get a GM value for the Kaliketek route of 0.79 while the ferry boat route is 0.81. The GM value is used to find the VP value by dividing each GM value by the total GM value. From the calculation, the VP value for the Kaliketek route is 0.49 and for the boat crossing route is 0.51. The choice of an alternative connecting route as a result of the construction of the Simo-Glendeng Bridge for 2 wheels is a boat route with a priority vector value of 0.51 and an emphasis on the time factor with a priority vector value of 0.51.

K-Means Cluster-based Random Undersampling and Meta-Learning Approach for Village Development Status Classification

There is a significant imbalanced class in the village development index (called IDM - Indeks Desa Membangun) dataset, marked by the number of self-supporting classes more than the disadvantaged class. The traditional classifiers are able to achieve high accuracy (ACC) by training all cases of the majority class but forsaking the minority class, so that possible for the classification results to be biased. In this study, a random under-sampling technique was employed based on k-means cluster (KMC) and a meta-learning approach to improving ACC of the village status classification model. Furthermore, the AdaBoost and Random Forest were used as meta technique and base learner, respectively. The proposed model has been evaluated using the area under the curve (AUC), and experimental results showed that it yielded excellent performance compared to the prior studies with the AUC, ACC, precision (PR), recall (RC), and g-mean (Gm) values of 95.50%, 95.52%, 95.5%, 95.5%, and 92.95%, respectively. Similarly, the result of the t-test also showed the proposed model yielded excellent performance compared to previous studies. It can be concluded that the AdaBoost algorithm improved misclassification and changed the distribution of data loss function in random forests. It indicates that the proposed model effectively deals with imbalanced classes in the village development status classification model.Â

The Use of Galactomannan Antigen Assays for the Diagnosis of Invasive Pulmonary Aspergillosis in the Hematological Patient: A Systematic Review and Meta-Analysis

The optimal cut-off value of the optical density index of the galactomannan antigen assays (GM) for diagnosing invasive pulmonary aspergillosis in hematological patients is a disputed topic. This article conducts a systematic review with a meta-analysis to establish which optical density index (ODI) cut-off value should be implemented into clinical practice. Pubmed, Embase and Cochrane databases were searched (N = 27). The pooled data, using a generalized linear mixed model with binomial distribution, resulted in an overall serum sensitivity of 0.76 and a specificity of 0.92. For serum ODI 0.5 there was a pooled sensitivity of 0.92 and a specificity of 0.84. The pooled data of all broncho-alveolar lavage (BAL) studies resulted in an overall sensitivity of 0.80 and a specificity of 0.95. For BAL ODI 0.5, there was a pooled sensitivity of 0.75 and a specificity of 0.88. For the BAL ODI 1.0 pooling, the studies resulted in a sensitivity of 0.75 and a specificity of 0.96. Serum ODI of 0.5 and BAL ODI of 1.0 are the most suitable cut-offs for clinical practice. However, our study affirms that the evidence for the use of GM in clinical practice for the hematological malignancy patient is currently insufficient and more research is needed to determine the diagnostic value of GM.

Mechanical properties and micro mechanism of alkali-activated tannery sludge/fly ash composite cement-based recycled concrete

In order to alleviate the environmental degradation and resource waste caused by cement production and construction waste disposal, some cement is replaced by tannery sludge and fly ash, and natural aggregate is replaced by recycled coarse aggregate. The preparation of alkali activated tannery sludge/fly ash composite cement-based recycled concrete (AA-SFRC) is of great significance for the safe disposal and utilization of solid waste. In order to study the mechanism of the effect of alkali-activator on the mechanical properties and microstructure of AA-SFRC, six kinds of AA-SFRC with different alkali equivalents (AE) were designed, and the strength tests, nuclear magnetic resonance (NMR), X-ray diffraction (XRD) and scanning electron microscopy (SEM) tests were carried out. On this basis, the influence of AA-SFRC pore structure parameters on strength performance was discussed by using grey entropy analysis method, and a grey model GM (1, 5) prediction model of 28d strength was established. The results demonstrated that with the increase of AE, the AA-SFRC strength increased at first and then decreased, and the tension–compression ratio (Ts/Cs) remained in the normal range, between 0.065 and 0.081. When the AE was 9%, the mineral composition of AA-SFRC reached equilibrium, and the hydration reaction was the most sufficient. The compressive strength and splitting tensile strength reached the maximum. Meanwhile, the pore structure showed that the porosity and the proportion of macro pores were the smallest. The 28d strength of AA-SFRC was greatly affected by its 7d strength, first peak ratio, fractal dimension Dmax and porosity. The average relative errors between the predicted value of GM (1, 5) model and the experimental value were less than 0.03%. This study can provide a reference for the resource utilization of tannery sludge, fly ash and construction waste.

Downsizing the Channel Length of Vertical Organic Electrochemical Transistors.

Organic electrochemical transistors (OECTs) are promising building blocks for bioelectronic devices such as sensors and neural interfaces. While the majority of OECTs use simple planar geometry, there is interest in exploring how these devices operate with much shorter channels on the submicron scale. Here, we show a practical route toward the minimization of the channel length of the transistor using traditional photolithography, enabling large-scale utilization. We describe the fabrication of such transistors using two types of conducting polymers. First, commercial solution-processed poly(dioxyethylenethiophene):poly(styrene sulfonate), PEDOT:PSS. Next, we also exploit the short channel length to support easy in situ electropolymerization of poly(dioxyethylenethiophene):tetrabutyl ammonium hexafluorophosphate, PEDOT:PF6. Both variants show different promising features, leading the way in terms of transconductance (gm), with the measured peak gm up to 68 mS for relatively thin (280 nm) channel layers on devices with the channel length of 350 nm and with widths of 50, 100, and 200 μm. This result suggests that the use of electropolymerized semiconductors, which can be easily customized, is viable with vertical geometry, as uniform and thin layers can be created. Spin-coated PEDOT:PSS lags behind with the lower values of gm; however, it excels in terms of the speed of the device and also has a comparably lower off current (300 nA), leading to unusually high on/off ratio, with values up to 8.6 × 104. Our approach to vertical gap devices is simple, scalable, and can be extended to other applications where small electrochemical channels are desired.

Brain morphometric changes in fibromyalgia and the impact of psychometric and clinical factors: a volumetric and diffusion-tensor imaging study

BackgroundPrevious studies have repeatedly found distinct brain morphometric changes in patients with fibromyalgia (FM), mainly affecting gray and white matter abnormalities in areas related to sensory and affective pain processing. However, few studies have thus far linked different types of structural changes and not much is known about behavioral and clinical determinants that might influence the emergence and progression of such changes.MethodsWe used voxel-based morphometry (VBM) and diffusion-tensor imaging (DTI) to detect regional patterns of (micro)structural gray (GM) and white matter (WM) alterations in 23 patients with FM compared to 21 healthy controls (HC), while considering the influence of demographic, psychometric, and clinical variables (age, symptom severity, pain duration, heat pain threshold, depression scores).ResultsVBM and DTI revealed striking patterns of brain morphometric changes in FM patients. Bilateral middle temporal gyrus (MTG), parahippocampal gyrus, left dorsal anterior cingulate cortex (dACC), right putamen, right caudate nucleus, and left dorsolateral prefrontal cortex (DLPFC) showed significantly decreased GM volumes. In contrast, increased GM volume was observed in bilateral cerebellum and left thalamus. Beyond that, patients displayed microstructural changes of WM connectivity within the medial lemniscus, corpus callosum, and tracts surrounding and connecting the thalamus. Sensory-discriminative aspects of pain (pain severity, pain thresholds) primarily showed negative correlations with GM within bilateral putamen, pallidum, right midcingulate cortex (MCC), and multiple thalamic substructures, whereas the chronicity of pain was negatively correlated with GM volumes within right insular cortex and left rolandic operculum. Affective-motivational aspects of pain (depressive mood, general activity) were related to GM and FA values within bilateral putamen and thalamus.ConclusionsOur results suggest a variety of distinct structural brain changes in FM, particularly affecting areas involved in pain and emotion processing such as the thalamus, putamen, and insula.

Improvement of AlGaN/GaN HEMTs Linearity Using Etched-Fin Gate Structure for Ka Band Applications.

In this paper, AlGaN/GaN high electron mobility transistors (HEMTs) with etched-fin gate structures fabricated to improve device linearity for Ka-band application are reported. Within the proposed study of planar, one-etched-fin, four-etched-fin, and nine-etched-fin devices, which have 50-μm, 25-μm, 10-μm, and 5-μm partial gate widths, respectively, the four-etched-fin gate AlGaN/GaN HEMT devices have demonstrated optimized device linearity with respect to the extrinsic transconductance (Gm) value, the output third order intercept point (OIP3), and the third-order intermodulation output power (IMD3) level. The IMD3 is improved by 7 dB at 30 GHz for the 4 × 50 μm HEMT device. The OIP3 is found to reach a maximum value of 36.43 dBm with the four-etched-fin device, which exhibits high potential for the advancement of wireless power amplifier components for Ka band applications.