bluuebunny/crossref_metadata_2025_split huggingface dataset:
Suppressing label noise in medical image classification using mixup attention and self-supervised learning
Authors: Gao Mengdi , Jiang Hongyang , Hu Yan , Ren Qiushi , Xie Zhaoheng , Liu Jiang 
Published: April 2024

Abstract
Deep neural networks (DNNs) have been widely applied in medical image classification and achieve remarkable classification performance. These achievements heavily depend on large-scale accurately annotated training data. However, label noise is inevitably introduced in the medical image annotation, as the labeling process heavily relies on the expertise and experience of annotators. Meanwhile, DNNs suffer from overfitting noisy labels, degrading the performance of models. Therefore, in this work, we innovatively devise a noise-robust training approach to mitigate the adverse effects of noisy labels in medical image classification. Specifically, we incorporate contrastive learning and intra-group mixup attention strategies into vanilla supervised learning. The contrastive learning for feature extractor helps to enhance visual representation of DNNs. The intra-group mixup attention module constructs groups and assigns self-attention weights for group-wise samples, and subsequently interpolates massive noisy-suppressed samples through weighted mixup operation. We conduct comparative experiments on both synthetic and real-world noisy medical datasets under various noise levels. Rigorous experiments validate that our noise-robust method with contrastive learning and mixup attention can effectively handle with label noise, and is superior to state-of-the-art methods. An ablation study also shows that both components contribute to boost model performance. The proposed method demonstrates its capability of curb label noise and has certain potential toward real-world clinic applications.
Ar(1s5) density in a co-axial argon plasma jet with N2–O2 shielding
Authors: Gonçalves Duarte , Bauville Gérard , Jeanney Pascal , Lino da Silva Mário , Lemos Alves Luís , Pasquiers Stéphane , Santos Sousa João 
Published: April 2024

Abstract
Atmospheric-pressure microplasma jets (µAPPJs) are versatile sources of reactive species with diverse applications. However, understanding the plasma chemistry in these jets is challenging due to plasma-flow interactions in heterogeneous gas mixtures. Spatial metastable density profiles help to understand these physical and chemical mechanisms. This work focuses on controlling the shielding gas around a µAPPJ. We use a dielectric barrier discharge co-axial reactor where a co-flow shields the pure argon jet with different N2–O2 gas mixtures. A voltage pulse (4 kV, 1 µs, 20 kHz) generates a first discharge at the pulse’s rising edge and a second discharge at the falling edge. Tunable diode laser absorption spectroscopy measures the local Ar(1s5) density. A pure N2 (100%N2–0%O2) co-flow leads to less reproducible and lower peak Ar(1s5) density (

5.8
×

10

13

cm

−
3

). Increasing the O2 admixture in the co-flow yields narrower Ar(1s5) absorbance profiles and increases the Ar(1s5) density (

6.9
×

10

13

to

9.1
×

10

13

cm

−
3

). The position of the peak density is closer to the reactor for higher O2 fractions. Absence of N2 results in comparable Ar(1s5) densities between the first and second discharges (maxima of

9.1
×

10

13

and

9.3
×

10

13

cm

−
3

, respectively). Local Ar(1s5) density profiles from pure N2 to pure O2 shielding provide insights into physical and chemical processes. The spatially-resolved data may contribute to optimising argon µAPPJ reactors across the various applications and to validate numerical models.
Behavior of quantum coherence in quantum phase transitions of two-dimensional XY and ising models
Authors: Taghadomi N , Mani A , Bakouei A 
Published: April 2024

Abstract
We investigate the quantum coherence behavior of the ground states of 2D Heisenberg XY model and 2D Ising model with a transverse field on square lattices using the Quantum Renormalization Group (QRG) method. Our analysis focused on the ground state density matrix and its marginal states, revealing non-analytic behavior of quantum coherence (especially two-site coherence) near the critical point. This behavior allowed us to detect quantum phase transitions (QPT) in these models. By examining the scaling behavior of the maximum derivative of quantum coherence with system size, we determined the critical exponent of coherence for both models and the length exponent of the Ising model. Additionally, we investigated the time evolution of coherence in both models. Our results closely align with those obtained from entanglement analysis, that is while quantum coherence requires fewer computational calculations compared to discord and entanglement approaches.
Construction and volumetric benchmarking of quantum computing noise models
Authors: Weber Tom , Borras Kerstin , Jansen Karl , Krücker Dirk , Riebisch Matthias 
Published: April 2024

Abstract
The main challenge of quantum computing on its way to scalability is the erroneous behaviour of current devices. Understanding and predicting their impact on computations is essential to counteract these errors with methods such as quantum error mitigation. Thus, it is necessary to construct and evaluate accurate noise models. However, the evaluation of noise models does not yet follow a systematic approach, making it nearly impossible to estimate the accuracy of a model for a given application. Therefore, we developed and present a systematic approach to benchmarking noise models for quantum computing applications. It compares the results of hardware experiments to predictions of noise models for a representative set of quantum circuits. We also construct a noise model containing five types of quantum noise and optimize its parameters using a series of training circuits. We compare its accuracy to other noise models by volumetric benchmarks involving typical variational quantum circuits. The model can easily be expanded by adding new quantum channels.
Core electron temperature turbulence and transport during sawtooth oscillations in the DIII-D tokamak
Authors: Wang G. , Rhodes T.L. , Pratt Q.T. , Peebles W.A. , Crocker N.A. , Hong R. , Austin M.E. , Van Zeeland M.A. , Smith S.P. 
Published: April 2024

Abstract
Sawteeth are one of the concerning instabilities in ITER and future burning plasma experiments. Sawtooth dynamics and its interaction with broadband plasma turbulence has been a challenge for predictive simulations of core transport in future fusion devices. This study provides new observations of core turbulence behavior during sawtooth oscillations in DIII-D hydrogen L-mode neutral beam injection heated plasmas in an inner wall limited configuration. A strong correlation of electron temperature and density turbulence levels with the sawtooth oscillation phase has been observed at locations inside the T
e inversion radius and/or safety factor q = 1 magnetic surface. The T
e turbulence amplitude in the core during the sawtooth ramp exhibits a critical T
e gradient behavior inside but not near the T
e inversion radius/q = 1 magnetic surface. The most unstable mode calculated from the trapped gyro-landau fluid turbulence simulations reveal a change from low-k ion-type to low-k electron-type modes from pre- to post- sawtooth crash time periods.
Physical Properties of Biochar Produced from Pyrolysis of Arabica Coffee Pulp: The Effect of Pre-Washing Process
Authors: Setiawan A , Muhammad F , Nurjannah S , Riskina S , Muhammad  , Hakim L 
Published: April 2024

Abstract
Coffee pulp is a potential source of biomass which abundantly available in coffee exporter countries such as Brazil, Colombia, Indonesia etc. It is necessary to develop technologies to convert coffee pulp into value-added products. This study aims to investigate the slow pyrolysis process of arabica coffee pulp in a pilot scale reactor and evaluate the properties of resulting biochar. Prior to pyrolysis experiment, some of coffee pulp were soaked in tap water for 20 h with a ratio of water to coffee pulps of 1:5. As comparison, another set of pyrolysis experiment was carried out without soaking and washing of feedstock. The pyrolysis process was carried out in a batch reactor at temperatures within the range of 400 to 420°C. During the run, the reaction temperature versus time was recorded and products yield were quantified. Characterization of biochar product was performed under proximate, bomb calorimeter and density analyses. The yield of biochar and pyrolytic oil, respectively were 33% and 36%. Biochar characterization results suggested a significant decrease in the ash content when washing pretreatment was applied. Increases in the calorific value and bulk density were also observed from pre-washed coffee pulp sample.
Potential Torrefaction of Tropical Forest Fruits Waste
Authors: Prayitno H , Amrul  , Lestari R , Kurniawansah R 
Published: April 2024

Abstract
Biomass torrefaction can improve the quality of raw biomass as fuel. Tropical forest fruit waste that is not managed properly will become waste that contributes to increasing greenhouse gas emissions. Conversion of tropical forest fruit waste into biomass fuel by torrefaction can be used as coal co-firing. In this research, torrefaction was carried out on the biomass from the cocoa pod shell, coffee husks, and mangosteen pod shell. The samples used in this study came from tropical forest fruits in Lampung Province. Samples were chopped and dried using the hot sun. The samples were then torrefied in a tubular reactor at temperatures of 250, 275, and 300°C and their calorific values were tested. Torrefaction at 275°C has increased the calorific value of tropical forest fruit waste to exceed the calorific value of sub-bituminous A. Torrefaction of tropical forest fruit waste has the potential to be used as fuel for co-firing coal in power plants. Thus, it can indirectly reduce the rate of CO2 emissions from power generation and waste accumulation. In addition, it also has the potential to become a competitive sustainable export commodity.
The Effect of Use of Adhesive to Calorific Value Cymbopogon Nardus Waste Briquettes
Authors: Hendri N , Sari D Y , Wagino  , Sakti D , Ramadhan A 
Published: April 2024

Abstract
The consumption of fuel in the community is getting higher day by day so it has an impact on its shortage and scarcity. The search for potential energy sources as alternative fuels is increasingly being developed. In this livelihood, renewable alternative energy is needed. The Cymbopogon nardus plant which has taken its oil through a refining process and eventually becomes waste is still possible for use as briquettes. This study will examine Cymbopogon nardus waste briquettes’ calorific value with the use of tapioca and damar adhesives so that their presence can be applied to the community. The method of making briquettes made from Cymbopogon nardus waste with a concentration ratio of 90%, 80%, 70%, and 60% of the use of adhesives. The combination of raw materials and adhesives is then given a compaction compression process. The result of research, Cymbopogon nardus waste briquettes the calorific value with tapioca adhesive is 9972.55 kJ/kg at a ratio of 90%, while the calorific value with damar adhesive is 11318.84 kJ/kg. The use of adhesives in the process of making Cymbopogon nardus waste briquettes shows the effect of the calorific value. Of course, the hope in the development of briquettes that utilize Cymbopogon nardus waste makes a real opportunity to be applied to the community in efforts to develop renewable energy.
Thermodynamic Simulation of Cascade Cooling System for Vacuum Freeze Drying
Authors: Buana I , Kosasih E A 
Published: April 2024

Abstract
Vacuum freeze drying (VFD) is a drying method carried out at pressures and temperatures below the triple point of water. Drying occurs by sublimation. The results of the VFD method are able to maintain the quality of dry ingredients (taste, colour, nutrient, etc.). To achieve a condition below the triple point of water, it is conditioned so that the pressure is under a partial pressure of 6.11657 mbar at a temperature of 0.01°C. The refrigeration system is simulated using refrigerants R-134a and R-22. The purpose of the simulation is to obtain the optimum system conditions. The variables varied were the saturated temperature of the LTC (Low-Temperature Circuit) evaporator, the saturation temperature of the HTC (High-Temperature Circuit) evaporator, the difference in the temperature of the pinch point between the LTC condenser and the HTC evaporator and the temperature of the HTC condenser. The simulation results are the saturated temperature of the LTC evaporator -30°C, the saturation temperature of the HTC evaporator -15°C, the difference in the temperature of the pinch point between the LTC condenser and the HTC evaporator 10°C and the temperature of the HTC condenser 40°C. The highest Coefficient of Performance (COP) of the cascade cooling system with these parameters is 2.55 using a combination refrigerant R22 in HTC and R134a in LTC.
Application of Soy Wax Phase Change Material as Thermal Energy Storage in Wall Building
Authors: Trisnadewi T , Putra N 
Published: April 2024

Abstract
High solar radiation in the tropics area buildings and inappropriate selection of building materials cause an increase in room temperature which interferes with thermal comfort. This study aims to reduce the absorption of heat received in the building with the modification of building walls by adding Phase Change Material (PCM) as Thermal Energy Storage (TES). Soy wax is an organic PCM that is abundant in Indonesia, cheap, and has a melting point of 43.92°C and a freezing point of 38.49°C, which are the range of solar heat radiation in buildings. The application of soy wax on the walls of the building is carried out using a prototype room 80x105x60 cm made of Plywood with a 1 cm thickness of soy wax in the middle of the wall. The test was carried out by comparing the prototype without and with a layer of soy wax pack on the wall. Based on the tests carried out for 24 hours, it was found that the addition of soy wax on the prototype wall can decrease the room temperature to 37°C from 41°C during the day. The use of soy wax can absorb the heat received by the building by 10% at peak load and has a small heat transfer rate of 15.56 W so the heat transferred into the room is small. Soy wax walls function as insulators on the walls and can withstand heat absorbed from outside the building so that it is not completely transferred into the room.
Thermal Properties Characteristic of Aluminium-Alumina Composite for Solar Water Heating System Application
Authors: Hasan Basri Muhammad , Jalaluddin  , Tarakka Rustan , Syahid Muhammad , Amijoyo Mochtar Andi , Anis Ilahi Ramadhani M. 
Published: April 2024

Abstract
Thermal Energy Storage (TES) is an energy storage mechanism or material with modern technology at low costs, such as metal, concrete, composites, and others. Aluminum (Al)–Alumina (Al2O3) Composite is a solid material with high strength and hardness characteristics that can work in low-temperature applications. This study aims to analyze the features of the thermal properties of composite materials in the form of thermal conductivity and specific heat capacity. Composite specimens were prepared using powder metallurgy techniques. The weight fraction of alumina in the composite is 35%, 50%, and 65%. There are three (3) composite models, namely C1(35Al-65Al2O3), C2 (50Al-50Al2O3), and C3(65Al-35Al2O3). Models were made using the cold compaction method with a compressive load of around 20-25 MPa, and the specimens were fired in a furnace at a temperature of 550 °C with a holding time of 30 minutes. Scanning Electron Microscopy analyzed the microstructure of the composites. Composite thermal conductivity test using a thermal conductivity apparatus, and composite heat capacity test using a Differential Scanning Calorimetry (DSC). The results showed that C1(35Al-65Al2O3) composite had higher density and specific heat capacity than C2 and C3 composites. The theoretical density and specific heat capacity values of the C1 composite are 3.39 g/cm3 1.36 J/g.°C. However, the value of the thermal conductivity of C1(35Al-65Al2O3) material is lower than the other composites with a value of 0.37 W/m.°C. The greater the percentage by weight of alumina in the aluminum-alumina composite, the more theoretical density and specific heat capacity will also increase. Still, the thermal conductivity of the composite will decrease. Composite C1 35Al-65Al2O3 can potentially be a heat energy storage material used in solar water heating systems because of its high density and heat capacity.
Surface Roughness Analysis and Optimization for ST 37 Steel in Lathe Operation using Design of Experiments Method
Authors: Siti Nurrohkayati Anis , Syach Sabaruddin , Takdir Muhammad 
Published: April 2024

Abstract
The machining process is one of the processes used to process steel materials. The value or level of material roughness is one of the values that is considered in the machining process, according to the desired roughness value. One example is in the turning process, spindle speed, depth of feed, and feed motion are factors that can affect the level of roughness of a material. The level of roughness that is not according to demand is one of the problems in the manufacturing industry, especially in the results of the turning process. One of the causes of the discrepancy in the roughness value is because the parameters used are not suitable. Therefore, this study aims to determine the optimal parameters in the turning process to obtain the optimal roughness value, and to determine the parameters that most influence the roughness of the turning process. In this study, ST 37 steel was used. This study used an experimental design method with Orthogonal Array L8. The experiment was carried out with 5 control factors and 3 noise factors. Each factor has 2 levels and is repeated 8 times. In this study using a conventional lathe and for roughness testing using a Surface Roughness Tester. Based on the results of data analysis, the movement factor has the highest influence on the surface roughness value. The ranking factors that affect the roughness value are as follows: spindle speed of 345 rpm, feed motion of 0.051 mm/rad, depth of cut 1 mm, dry cooling, and automatic sledding. The Design of Experiments (Taguchi) method use quality characteristics to determine the results of the analysis. In this study, the quality characteristic is smaller the better. Smaller the better characteristics is where the smaller value, then better the quality. In variations of the spindle rotation speed and feed motion, we get where if the spindle speed is high and the feed motion is low it will produce a low level of roughness, whereas if the spindle speed is low and the feed movement is high it will produce a high level of roughness.
Effect of Tool Profile on Mechanical Properties, Temperature, and RPM Using Micro Friction Stir Spot Welding (mFSSW) on Aluminum Alloy AA1100
Authors: Safitri L A , Fakhrurrozi I F , Amat M A , Baskoro A S , Rupajati P , Kiswanto G 
Published: April 2024

Abstract
Micro friction stir spot welding (mFSSW) is a type of solid-state spot welding of nonconsumable tools using friction and force to join material of thickness less than 1 mm. This research aimed to investigate the shape of the tools for best welding results among the proposed tool’s profile. The material specimen was aluminum alloy AA1100, with a thickness of 0.42 mm. This study aims to measure the temperature and RPM of the welding process with thermocouples and tachometers. And then investigate the mechanical properties using the tensile shear test, microhardness, and macrostructural observation to find the welding zone and hook profile. Four tools’ profiles are named tool 1, tool 2, tool 3, and tool 4. The result of this study was that tool 3 (Shoulder 450μm) had the highest temperature, around 428˚ C, and the shear tensile test was 450 N (the highest). The macrostructural observation used to define the zone on the welding result there are stir zone (SZ), thermos-mechanically affected zone (TMAZ), and heat affected zone (HAZ).
Identification of Water Hyacinth Fiber (Eichornia Crassipes) and Polyethylene Terephthalate Waste as an Alternative Material
Authors: Junus S , Uloli R F , Rauf F A , Renreng I , Syahid M , Hayat A , Uloli H 
Published: April 2024

Abstract
Synthetic fiber is reinforcing material made and developed by human involving chemical reactions to change the structure or strengthen certain material. Synthetic fiber has high temperature resistance and is sturdy, strong, and elastic. Although synthetic fiber has good properties, it poses a serious problem of non-organic waste. Thus, it encourages changes in composite technology to pay more attention to natural fiber that are enviromentally friendly. This research used water hyacinth fiber and plastic waste as filler and polyester resin as matrix, to determine the mechanical properties of tensile test. The research employed hand lay-up method by arranging the fiber randomly at the composition of fiber variations of 10%, 20%, and 30% of the stress, strain, and modulus elasticityof the composite. The research finding were described in each fiber variations, where the average stress value at fiber variations of 10% 48,556 Mpa, strain was 1,4% and modulus elasticity was 36,264 Mpa. In addition, the fiber variation of 20% contained an average stress value of 44,178 Mpa, strain of 1,3% and modulus elasticity of 35,037 Mpa. Lastly, the fiber variation 30% contained an average stress value of 54,556 Mpa, strain of 1,2% and modulus elasticity of 46,811 Mpa. In the meantime, the tensile strength of 30% fiber variation owned the largest value compared the other fiber variations. While the 10% fiber variation strain owned the largest value compared the other fiber variations. Additionally, the elastic modulus of 30% fiber variation owned the largest value compared to the other fiber variations.
Utilization of Bamboo Roots as Reinforcing Composite Materials for Light Vehicle Dashboards
Authors: Mulyanti J , Sukamto  , Supriyanto  , Hendra D , Megaprastio B 
Published: April 2024

Abstract
Bamboo roots are residual material from the utilization of bamboo trees’ waste. Bamboo roots utilize in engineering by making new materials in the form of composites. Bamboo roots are easy to get, and getting bamboo root fiber is relatively easy compared to getting bamboo stem fiber. Bamboo root fibers are used as reinforcement in composites with resin binders and catalysts as hardeners. The composite made by mixing the composition consists of 10% bamboo root fiber, 89% resin, and 1% catalyst from the weight of the specimen. This composition uses three variations of fiber direction; straight, random, and woven fiber—each variation tests tensile strength, impact, and bending strength. Those three test results show that the highest values come from the woven fiber, which are 21.04 MPa from the tensile strength, 0.0693 J/mm2 from the impact value, and 34.789 MPa from the bending strength value. The test result found that applying bamboo roots composite material suits dashboard material for light vehicles (cars and motorcycles). This test result meets the standard material for dashboard vehicles based on plastic material data ABS (Acrylonitrile butadiene styrene). This research on natural fiber composite material is novel and valuable as a waste utilization solution for engineering materials.