bluuebunny/crossref_metadata_2025 huggingface dataset:
Simulation study of a novel GaN on Si quasi-vertical reverse-conducting insulated gate bipolar transistor
Authors: Zhao Wen , Zhang Peng , Xu Jiarui , Du Jiale , Hou Bin , Zhu Jiejie , Ma Xiaohua , Hao Yue
Published: October 2024

In this paper, a novel GaN on Si quasi-vertical reverse conducting insulated gate bipolar transistor (RC-IGBT) with NPN structure is proposed. The distinctive feature of this device structure is that the collector, emitter and gate are all fabricated on the wafer surface, eliminating the two major challenges associated with conventional PNPN structures: the difficulty in forming ohmic contacts due to the activation difficulty of the bottom p-GaN layer and the necessity of creating backside via holes for the collector electrode. Additionally, the heavily doped n+ GaN in the emitter and RC region can be selectively regrown by Metal-organic Chemical Vapor Deposition (MOCVD) /MBE. It avoids the deterioration of ohmic contact characteristics caused by etching of p-GaN on the top layer of n+ GaN during p-collector electrode fabrication. Compared to fully vertical GaN-based IGBT devices, the device has the feasibility of wafer level preparation technology. In this paper, Silvaco TCAD is used to simulate the static and dynamic characteristics of this novel device. The simulation results reveal that the device has a high saturation current density of 10 528.16 A cm−2 at V
g = 14 V, a threshold voltage (V
th) of 5 V, a breakdown voltage of 1103 V, and a total turn-on time of 3.14 ns, total turn-off time of 9.19 ns. The calculated turn-on and turn-off conduction losses for the RC-IGBT device are 0.438 mJ cm−2 and 9.12 mJ cm−2. Compared to other GaN-based IGBT devices, the novel GaN-based IGBT device has faster switching speed, lower switching loss and smaller chip area. Furthermore, we investigated the effects of the doping concentration of the field stop layer, drift region doping concentration, and collector region p/n+ length ratio on the ‘snapback’ phenomenon of the RC-IGBT device. We also studied the impact of stage etching width and depth on the device’s output current capability and latch-up characteristics.
Impact of facet degree heterogeneity on phase transitions in infectious disease spread
Authors: Xi Yuxia , Hu Jianghong , Luo Jianfeng , Li Xing , Li Yihong , Luo Xiaofeng , Guo Zunguang
Published: October 2024

Complex dynamical behaviors, such as bistable and periodic phenomena, have been shown to emerge due to group interactions in higher-order networks. Traditionally, the transitions between these behaviors are primarily driven by changing model parameters that represent the transmission characteristics of a single infectious disease, while maintaining a fixed network structure. However, for newly emerging infectious diseases, modifying network structures is crucial as transmission characteristics are generally fixed. This study investigates transitions between these dynamical behaviors by altering the network structure, specifically facet degree heterogeneity in the simplicial complex, under same model parameters. We develop a dynamical model incorporating facet degree distributions and derive the corresponding outbreak thresholds. Firstly, we validated the rationality of the model using Monte Carlo simulation. Subsequently, by comparing the general model and the base model under the same and different network structures, we demonstrate the advantage of the general model in capturing dynamical behavior. Furthermore, it was discovered that variations in the facet degree heterogeneity lead to phase transitions of the stability region of equilibrium. We finally provide the distribution of the stable equilibrium regions with varying facet degree heterogeneity. These findings offer valuable insights for the prevention and control of infectious diseases.
Periodic, quasi-periodic, chaotic waves and solitonic structures of coupled Benjamin-Bona-Mahony-KdV system
Authors: Hussain Amjad , Abbas Naseem
Published: October 2024

In this paper, we mainly focus on studying the dynamical behaviour and soliton solution of the coupled Benjamin-Bona-Mahony-Korteweg–de Vries (BBM-KdV) system, which characterizes the propagation of long waves in weakly nonlinear dispersive media. The paper utilizes different tools to detect chaos, such as time series analysis, bifurcation diagrams, power spectra, phase portraits, Poincare maps, and Lyapunov exponents. This analysis helps in more accurate predictive modeling of the systems. This understanding can aid in the design of control strategies, resulting in enhancements in prediction, control, optimization, and design. Additionally, we construct the system’s solitary wave structures using the Jacobi elliptic function (JEF) method. We identify periodic wave solutions expressed in terms of rational, hyperbolic, and trigonometric functions. Certain parameter values can lead to periodic wave solutions, solitary waves (bell-shaped solitons), shock wave solutions (kink-shaped soliton solutions), and double periodic wave solutions.
Device to circuit level implementation of JL-NSFET for DC/analog/RF applications at sub-5nm technology node: design optimization and temperature analysis
Authors: Bheemudu Vadthya , Vaithiyanathan Dhandapani , Kaur Baljit
Published: October 2024

This manuscript introduces, for the first time, a novel approach that incorporates a comprehensive analysis of sheet variations (1–5) and every individual sheet wise temperature variation, and as well as an investigation of various GS high-k gate dielectrics in Junction-less (JL) Nanosheet FET (JL-NSFET). The study starting from device level (Digital/Analog/Radio Frequency) to circuit (CMOS Inverter and ring oscillator) as a whole package is investigated through well calibrated TCAD simulation and the results portrayed. NSFETs are the ultimate choice for integrated circuits (ICs) at sub-5 nm technology node. The notion of this paper is to design and optimization of NSFET with GS high-k gate dielectrics (Al2O3, HfO2, ZrO2 and TiO2) Initially. The switching/analog and RF metric revels that HfO2 is superior in terms SS, switching applications and more compactable with CMOS process. Further, adding number of sheets and temperature variation has been done later. As number of sheets increases, the effective channel width increases, electric field distribution takes place evenly and enhanced gate control owing to improved

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SS and DIBL. However, increasing the number of vertical channel layers (sheets) more than 2 results into diminished analog/RF performance of JL-NSFET owing to increased parasitic capacitances. Further, the impact of temperature variations (250 K to 450 K) studied for different sheet variations (1 to 5) and noticed that analog/RF such as gm, gds, fT, TFP and GTFP are enhanced by 40.82%, 28.76%, 40.69%, 64.62% and 70.59%, respectively at lower temperature (250 K) when compared to high temperature (450 K). These enhancements make the device is ideal for applications in cryogenic computing systems, satellites, deep space probes, and other aerospace technologies. Furthermore, as the circuit level implementation CMOS inverter and 5-stage ring oscillator (RO) are examined for different sheets and observed as sheets increase delay and EDP increases. For a CMOS inverter the NMH (0.295 V) and NML (0.280 V) are better at 2 sheets with a highest gain of 9.38 V/V. Hence, it is advised to use two or three sheets-based JL-NSFETs for high-performance and lower-power analog/RF applications.
Liquid vortex surface deformation probed by light reflection
Authors: Vu Danh Tien , Hoang Le Phuong , Tao Khoa Dang , Nguyen Nhu Thanh , Nguyen Cuc Thi Kim , Cao Binh Xuan
Published: October 2024

We propose a method that combines an optical system with image processing techniques to scrutinize the dependence of liquid vortex deformation on varying angular velocity based on light reflection on liquid surfaces due to dynamic wettability. In our experiment, a broadened and collimated laser beam is directed onto curved surfaces, providing information on the vortex parameters through the analysis of the reflected beam profile. Additionally, the physical model of the liquid surface in a rotating cylinder before dewetting is examined. We investigate the liquid vortex forms of a saline solution and propylene glycol across various angular velocities, comparing them to the ideal parabolic vortex surface shape. The results show that, under the same experimental conditions, the vortex profiles of both solutions are equivalent. The vortex surface shape at certain angular velocity values, as determined by fitting plots, closely resembles a parabola, with R2 > 99%. The proposed method introduces a new approach for characterizing the dynamics of liquids as well as monitoring natural phenomena.
Chlorophyll films for radiation dosimetry: a feasibility study
Authors: Chand Bhagat , Priyamvda  , Prasher Sangeeta , Kumar Mukesh
Published: October 2024

Novel Chlorophyll-PVA composite films have been prepared and tested for the dosimetry of therapeutic radiation. The radiation response has been quantified using UV–vis spectroscopy. FTIR and XRD spectroscopies have been used to characterize the physical properties and irradiation response of the films. The films have shown response towards the therapeutic x-rays beams of 6 MV nominal energy in the tested dose range of 0.25 Gy to 32 Gy in discrete dose levels occurring in the geometric progression series of 2. The dosimeter has been found to exhibit sensitivity at a low dose of 0.25 Gy. The dose response curve of the dosimeter exhibits an exponential relationship of the absorbance and absorbed dose. A region of saturated absorbance has been observed beyond 4 Gy. The peak intensities of the FTIR spectra have been found to decrease with increasing doses as compared to the unirradiated samples, because of the changes in the bond polarities and molecular geometries. The XRD spectra indicates a change in the molecular orientation resulting in a decrease in peak intensity with increasing dose. This study indicates the feasibility of chl-PVA films in the dosimetry of therapeutic radiation. This film dosimeter can be processed locally with minimum resources and standardized against a known standard before clinical use. The chlorophyll molecules need careful handling owing to their sensitivity to light and temperature.
Viable wormhole structures and energy conditions in f(Q, T) theory
Authors: Zeeshan Gul M , Sharif M , Shahid Shajee , Javed Faisal
Published: October 2024

This paper explores static wormhole solutions in f(Q, T) theory, where Q is the non-metricity and T is the trace of energy-momentum tensor. We derive the field equations that describe gravitational phenomena in the existence of non-metricity and matter source terms We examine different models of this theory to determine the explicit expressions of matter contents, which are useful for analyzing the wormhole structures. We investigate the existence of feasible traversable wormhole solutions for constant and variable redshift functions. To determine whether physically viable wormhole geometry exists, we examine the graphical interpretation of energy constraints for different values of model parameters. It is found that realistic traversable and stable wormhole solutions exist only for the first model of this gravity.
Device structural engineering and modelling of emerging III-nitride/β-Ga2O3 nano-HEMT for high-power and THz electronics
Authors: Rao G Purnachandra , Lenka Trupti Ranjan , Vadalà Valeria , Nguyen Hieu Pham Trung
Published: October 2024

III-nitrides, such as gallium nitride (GaN) and aluminium nitride (AlN), possess a wide bandgap, a high breakdown voltage, and a high thermal conductivity, making them an attractive choice for high frequency and high-power applications. A further benefit of III-nitride-based HEMTs is their high current density, low noise figure, and higher electron mobility, which enable efficient radio-frequency signal amplification. In this research work, the polarization induced graded buffer technique and improved lattice matched β-Ga2O3 substrate is employed to minimize the buffer-related issues in III-Nitride Nano-HEMTs (high electron mobility transistors), such as reduction in the buffer leakage current losses. The polarization-induced doping in buffer region can considerably reduce the buffer leakage current, enhance breakdown voltage and RF characteristics, and bend the conduction band upwardly convex, improving two-dimensional electron gas (2DEG) confinement. A detailed comparison between the graded buffer technique of the HEMT and the HEMT having normal buffer has been conducted. The results demonstrated that the suggested HEMT demonstrated better DC and RF characteristics up to the Tera (1012) hertz range of frequencies. The improved characteristics of the proposed HEMT allow it to be a feasible solution for emerging technologies and cutting-edge communication systems that require efficient signal processing at very high frequencies.
A novel miniaturized metamaterial inspired frequency reconfigurable antenna with switchable polarization for sub 6 GHz band
Authors: V Lavanya , C Rimmya , R K Rabin Kanisha , M Ganesh Madhan
Published: October 2024

A metamaterial-inspired frequency reconfigurable antenna with switchable polarization realized for 2.4 GHz, 3.5 GHz, and 5.8 GHz frequencies, is reported in this work. Initially, a conventional rectangular patch is designed to resonate at 3.5 GHz. A regular square-shaped SRR (Split Ring Resonator) is a metamaterial-inspired structure that excites additional resonance at 5.8 GHz, without increasing the antenna form factor. Further, a parasitic patch is introduced to create one resonance at 2.4 GHz. Reconfigurability of frequency and polarization is achieved using MPP4203 series PIN diodes. The antenna is simulated using CST Microwave Studio Suite 2019. The designed antenna, characterized by reflection coefficient and bandwidth is analysed for three diode states. The devised antenna operates at 2.4 GHz, 3.5 GHz, and 5.8 GHz, with a maximum bandwidth of 346.2 MHz at the 5.8 GHz frequency band. The radiator outperformed other similar antennas reported in the literature in terms of antenna size, bandwidth, and frequency cum polarization reconfigurability.
Unraveling the role of exercise in cancer suppression: insights from a mathematical model
Authors: Taylor Jay , Bagarti T , Kumar Niraj
Published: October 2024

Recent experimental studies have shown that physical exercise has the potential to suppress tumor progression. Such suppression has been reported to be mediated by the exercise-induced activation of natural killer (NK) cells through the release of IL-6, a cytokine. Aimed at shedding light on how exercise-induced NK cell activation helps in the suppression of cancer, we developed a coarse-grained mathematical model based on a system of ordinary differential equations describing the interaction between IL-6, NK-cells, and tumor cells. The model is then used to study how exercise duration and exercise intensity affect tumor suppression. Our results show that increasing exercise intensity or increasing exercise duration leads to greater and sustained tumor suppression. Furthermore, multi-bout exercise patterns hold promise for improving cancer treatment strategies by adjusting exercise intensity and frequency. Thus, the proposed mathematical model provides insights into the role of exercise in tumor suppression and can be instrumental in guiding future experimental studies, potentially leading to more effective exercise interventions.
Task-oriented EEG denoising generative adversarial network for enhancing SSVEP-BCI performance
Authors: Zeng Pu , Fan Liangwei , Luo You , Shen Hui , Hu Dewen
Published: October 2024

Objective. The quality of electroencephalogram (EEG) signals directly impacts the performance of brain–computer interface (BCI) tasks. Many methods have been proposed to eliminate noise from EEG signals, but most of these methods focus solely on signal denoising itself, disregarding the impact on subsequent tasks, which deviates from the original intention of EEG denoising. The main objective of this study is to optimize EEG denoising models with a purpose of improving the performance of BCI tasks. Approach. To this end, we proposed an innovative task-oriented EEG denoising generative adversarial network (TOED-GAN) method. This network utilizes the generator of GAN to decompose and reconstruct clean signals from the raw EEG signals, and the discriminator to learn to distinguish the generated signals from the true clean signals, resulting in a remarkable increase of the signal-to-noise ratio by simultaneously enhancing task-related components and removing task-irrelevant noise from the original contaminated signals. Main results. We evaluated the performance of the model on a public dataset and a self-collected dataset respectively, with canonical correlation analysis classification tasks of the steady-state visual evoked potential (SSVEP) based BCI. Experimental results demonstrate that TOED-GAN exhibits excellent performance in removing EEG noise and improving performance for SSVEP-BCI, with accuracy improvement rates reaching 18.47% and 21.33% in contrast to the baseline methods of convolutional neural networks, respectively. Significance. This work proves that the proposed TOED-GAN, as an EEG denoising method tailored for SSVEP tasks, contributes to enhancing the performance of BCIs in practical application scenarios.
Learning curves for deep structured Gaussian feature models*
Authors: Zavatone-Veth Jacob A , Pehlevan Cengiz
Published: October 2024

In recent years, significant attention in deep learning theory has been devoted to analyzing when models that interpolate their training data can still generalize well to unseen examples. Many insights have been gained from studying models with multiple layers of Gaussian random features, for which one can compute precise generalization asymptotics. However, few works have considered the effect of weight anisotropy; most assume that the random features are generated using independent and identically distributed Gaussian weights, and allow only for structure in the input data. Here, we use the replica trick from statistical physics to derive learning curves for models with many layers of structured Gaussian features. We show that allowing correlations between the rows of the first layer of features can aid generalization, while structure in later layers is generally detrimental. Our results shed light on how weight structure affects generalization in a simple class of solvable models.
An Optimization Design of Piezoelectric Hair Sensor for Oscillatory Flow Detection
Authors: Yu Yueyue , Xu Jinyong , Wang Yan , Zhong Ren , Hu Renqiu , Wang Zhou , Wu Xingchi , Zhang Zhanbiao
Published: October 2024

Biological hair is widely found in nature, and they are responsible for sensing and responding to environmental stimuli in living organisms. By simulating biological hair characteristics, they develop hair flow sensor to achieve high sensitivity detection of environmental factors such as small motion and fluid flow field. Output signal is the key indicator of hair flow sensor, and the improvement of output signal is important to the design of hair flow sensor. The existing hair flow sensor sensing structure is generally straight hair, and the output signal is limited by the structure, and the response is small. Using the direct piezoelectric fiber as the initial configuration, we form a new piezoelectric curved fiber by modeling the secondary spline curve and control point. We propose an optimization model for piezoelectric functional hair design using axial strain as a target function. At 100Hz and 500Hz, the output voltage of the optimized model is much higher than that of straight, 10 times and 7 times that of straight, respectively; An optimized curved hair configuration is obtained in a specific frequency band from 1 Hz to 500 Hz, whose average voltage magnitude of 3.1×10−3 V is 4 times greater than that of the straight hair of 7.8×10−4 V with the same size. The curved hair flow sensor breaks the output limitation of traditional straight hair configuration.
Measuring hydrologic regime alterations and hydrodynamic characteristics in the Xijiang River Basin by the IHA-RVA method
Authors: Wang Sen , Liu Xia , Wang Xiayu , Jia Wenhao
Published: October 2024

An objective assessment of hydrological alterations is crucial for comprehensive water resource management, environmental protection, river ecosystem restoration, and integrated watershed water resource management. To quantitatively assess the ecological hydrologic regime alterations in the Xijiang River Basin in southern China considering the impacts from Longtan Reservoir, daily runoff data from two hydrological stations, Dahuangjiangkou and Wuzhou, are selected from 1973 to 2020. The changes in the flow are analyzed, and the indicators of hydrological alternation/range of variability approach (IHA-RVA) are employed to assess the hydrological regime alternations in the studied basin. The main findings are as follows: (1) Both stations show a decreasing trend in annual runoff, with the moving T-test detecting a change point in the runoff series in 2002. (2) The two stations’ overall hydrologic alteration degrees are 57% and 60%, with a more remarkable variation in the upstream area. Hydrological station changes tend to wane as the distance from the reservoir increases, which indicates that with the increased reservoir-station distance, the impact of the reservoir on the hydrologic process diminishes.
Hydrodynamic analysis of a semi-submersible fish farming cage platform integrated with an oscillating water column wave energy converter
Authors: Yang Mengcheng , Du Zhichang , Chen Xiaokun , Lai Jiaxiong
Published: October 2024

This research article describes an investigation into integrating semi-submersible farm cages with oscillating water column (OWC) wave energy converters. The objective is to optimize the structural parameters of the platform through an examination of the impacts of three float structures. The AQWA hydrodynamic simulation software is employed to develop a numerical model to analyze the hydrodynamic properties of the semi-submersible farming platform. The findings suggest that the response to the heavy degree of freedom is positively correlated with the size of the floating structure. In contrast, the response of the roll degree of freedom is negatively correlated within a specific range. The results of this study establish a theoretical framework that can be utilized to optimize the design of semi-submersible farming platforms that integrate OWC technology.
Numerical simulation of the GPSD with different Length-to-Width ratios in dynamic water environment
Authors: Song Ruiming , Ding Youbin , Liu Lei , Zheng Lan , Li Fangling , Yu Lei , Ge Weijian
Published: October 2024

The gill-piece separation device (GPSD) is small, compact, and cost-effective in agricultural irrigation. To explore the influence of different length-to-width ratios on the water-sand two-phase flow field in the GPSD, numerical simulations of the velocity field and concentration field in the GPSD with different length-to-width ratios are conducted in a dynamic water environment by using the CFX software with the mixture model and RNG k – ε model. By comparing and analyzing the computational results, it is found that compared to the length-to-width ratios of 1:1, 2:1, and 3:1, the environment inside the gill-piece separation device with a ratio of 4:1 is more stable, and the formation of countercurrents is more pronounced; under dynamic water conditions, as the length-to-width ratio increases, the separation efficiency of the GPSD for water and sand increases. Among them, the water-sand separation efficiency of the GPSD with a ratio of 4:1 is the highest, reaching 90.41%, which is 2.26, 1.25, and 1.11 times higher than those of the ratios 1:1, 2:1, and 3:1, respectively.
Experimental study of combustion characteristics fuelled with biodiesel/diesel blends in high-pressure common rail electronically controlled diesel engines
Authors: Luo Li , Chen Ping , Wang Yin , Zhang Ping
Published: October 2024

Under the pressure of petroleum shortage and more stringent vehicle emission regulations at present, finding green and renewable alternative fuels has become an important research direction for the internal combustion engine. Due to the increment in oil imports, it is urgent to find a clean alternative fuel that will meet the diesel power and economic performance requirements. Biodiesel, with its renewable characteristics and wide resources, was considered, applied, and promoted extensively. The biodiesel studied in this paper is acidified oil biodiesel. The composition and ratio of acidified oil biodiesel were detected. The physicochemical indexes of acidified oil biodiesel/diesel fuel blends were measured and compared. In the electronically controlled high-pressure common rail diesel engine on different blending ratios of biodiesel/diesel fuel blends for a bench test, we analyze the combustion and characteristics. The results indicate that with the increasing biodiesel proportion, the peak of the premixed combustion and diffusion combustion in the cylinder increase, the combustion start point advances, the combustion duration shortens, and the maximum combustion temperature rises.
A control strategy of DC transmission system for offshore wind power based on hybrid converters
Authors: Peng Guangqiang , Song Yantao , Wu Jiyang , Huang Zhidi , Chen Lixin , Gong Ze
Published: October 2024

As the DC transmission system of modular multilevel converters for offshore wind power suffers problems like large volume, heavy weight, difficulty in platform transportation, and high cost, a DC transmission scheme for offshore wind power based on diode rectifier units and modular multilevel converters is put forth in the present work; Meanwhile, the features of active-power coordination, the DC harmonic current, and the AC harmonic current of the hybrid converter in this proposed scheme are analyzed to propose control strategies for active power coordination control, DC harmonic current suppression, and AC harmonic current suppression of the hybrid converter, respectively. The performance and feasibility of the proposed strategies are verified by testing the hardware in the loop real-time simulation system for transmission of offshore wind power through hybrid converters based on RTDS. It is found that the proposed strategies could improve the stability, flexibility, and reliability of the system.
Research on the influence of rigid body modes on the operating vibration of arc gate
Authors: Li Qin , Ding Peng , Ma Guangfei , Qiu Congwei
Published: October 2024

The 5# arc working gate of Jiangshan Wanyao Reservoir is composed of the suspension system of the gate and the steel wire rope, which has a serious vibration phenomenon when running without water. Firstly, the rigid body modal analysis of the gate suspension system is analyzed, the position size of key components such as gate support hinge shaft, gate motion guide embedded parts, and main beam position state is measured and evaluated on site, and the dynamic stress and vibration of the support arm are tested and analyzed during gate operation. It is concluded that the influence rule and weight of the steel wire rope on the rigid body mode of the gate, the torsional position of the gate, and the uneven operation condition of the side guide lead to the rigid body mode of the gate. It is suggested to improve the twisting state of the gate, adjust the unevenness of the embedded parts, and weaken the factors that induce the modal vibration of the rigid body.
Design and performance analysis of carbon brush collector ring end-face contact for hydro generator
Authors: Lv Yaru , Zhao Xinze , Li Chenshi , Zhao Meiyun
Published: October 2024

In hydro generators, the conventional radial contact method often results in unstable contact between carbon brush collector rings due to collector ring deflection. This paper presents a novel end-face contact method designed to enhance stability. The trajectory equations of the brush/ring contact are established when the collector ring swings and the “loss of contact” gaps of the two contact methods are compared. Further comparative analysis is conducted on the current-carrying friction wear of carbon brushes and collector rings in two contact modes. The results show that compared with the radial contact method, the brush/ring in the end-face contact method has a smaller gap and shorter time, the carbon brushes are less susceptible to spark erosion, the increase in friction coefficient and wear rate is small, and the contact resistance is lower and more stable. Scanning electron microscope analysis also shows that the spark erosion on the surface of the carbon brushes in the end contact mode is significantly weaker than that in the radial contact mode.
Loss reduction technical measures for DG-containing distribution networks based on maximizing loss reduction benefits
Authors: Chen Xin , Wang Guo
Published: October 2024

Loss reduction renovation of distribution networks is an important measure to improve the economic operation of distribution networks. The proportion of installed capacity of distributed generation (DG) in distribution networks will have an impact on the solutions of loss reduction measures, and the benefits generated by different solutions of loss reduction measures will differ to a greater or lesser extent. In order to maximize the loss reduction benefits, various loss reduction measures such as distribution network reconfiguration, distribution substation replacement, conductor replacement, and reactive power compensation, etc. were combined in this paper. The objective function of maximizing the loss reduction benefits after 10 years was used for mathematical modeling, and the Coati Optimization Algorithm (COA) was used to select and optimize the loss reduction technical measures. Finally, a distribution network with a distributed power supply was analyzed as an example to verify the effectiveness of the model.
Research on data processing of 3D modeling by images based on helicopter oblique photogrammetry
Authors: Mu Daocheng , Guo Shanchuan , Sun Jinquan , Zeng Lingsha
Published: October 2024

The use of tilting photogrammetry technology to build a refined urban 3D model has become the industry research hotspot with the rapid development of China’s “digital city.” To investigate and analyze the methodology of 3D data modeling using helicopter oblique photogrammetry, a 3D model was generated for a study area covering approximately 34 km2. This paper delves into the technical process of 3D modeling data processing utilizing helicopter oblique photogrammetry, and it examines the precision of the model results alongside a comprehensive technical analysis. The results show that the results of the process are consistent with the relevant specifications of the first-order 3D model landscape. Compared with the traditional 3D model, the method has obvious progress in efficiency and has a very wide application prospect.
Exploring the drag reduction caused by a combined spike and jet setup for a hypersonic blunt object at low elevations
Authors: Zhang Lingyun , Lei Juanmian , Guo Jian
Published: October 2024

When hypersonic vehicles fly at low altitudes during the end of the trajectory, they often face extremely high dynamic pressure and greater resistance. Studying the drag reduction features of the hypersonic vehicle at low altitudes is highly important. The Reynolds-averaged N-S equations are solved using the finite-volume method with the SST k-ω turbulence model. Numerical simulations are conducted on three-dimensional hypersonic flow fields involving spike and combined spike and jet configurations at low altitudes with hypersonic speeds to investigate drag reduction effects and analyze flow field characteristics. The data indicates that the presence of a spike can effectively reduce drag during low-altitude hypersonic flight. Enhancing the spike length, its drag reduction efficiency first increases and then slightly decreases. Enhancing the Mach number, the length of the spike that achieves the best drag reduction efficiency becomes longer. A spike and jet combination can enhance drag reduction efficiency when flying at an angle of attack. Enhancing the spike length or the pressure ratio in this configuration can enhance its effectiveness in reducing drag. The findings of this study provide practical guidance for developing drag-reduction strategies for hypersonic aircraft flying at low altitudes.
Multi-model strategies estimation and active intercept control of spacecraft via a zonotopic estimation approach
Authors: Che Haochi
Published: October 2024

This paper further explores the challenge of spacecraft interception games under incomplete information. The pursued spacecraft can change multiple evasive strategies, posing a pursuit problem for the interceptor that involves adapting to these changing strategies. A combination of interacting multiple model approach and zonotopic H
∞ observer is proposed to estimate the target’s unknown information. The interception strategies are then updated based on the estimated information. A simulation is given for comparison and to show their effectiveness.
Research on dangerous flight weather prediction based on machine learning
Authors: Liu Haoxing , Xie Renjie , Qin Haoshen , Li Yizhou
Published: October 2024

With the continuous expansion of the scale of air transport, the demand for aviation meteorological support also continues to grow. The impact of hazardous weather on flight safety is critical. How to effectively use meteorological data to improve the early warning capability of flight dangerous weather and ensure the safe flight of aircraft is the primary task of aviation meteorological services. In this work, support vector machine (SVM) models are used to predict hazardous flight weather, especially for meteorological conditions with high uncertainty such as storms and turbulence. SVM is a supervised learning method that distinguishes between different classes of data by finding optimal decision boundaries in a high-dimensional space. To meet the needs of this study, we chose the radial basis function (RBF) as the kernel function, which helps to deal with nonlinear problems and enables the model to better capture complex meteorological data structures. During the model training phase, we used historical meteorological observations from multiple weather stations, including temperature, humidity, wind speed, wind direction, and other meteorological indicators closely related to flight safety. From this data, the SVM model learns how to distinguish between normal and dangerous flight weather conditions.
Separation of measurement uncertainty into quantum and classical parts based on Kirkwood–Dirac quasiprobability and generalized entropy
Authors: Budiyono Agung
Published: October 2024

Measurement in quantum mechanics is notoriously unpredictable. The uncertainty in quantum measurement can arise from the noncommutativity between the state and the measurement basis which is intrinsically quantum, but it may also be of classical origin due to the agent’s ignorance. It is of fundamental as well as practical importance to cleanly separate the two contributions which can be directly accessed using laboratory operations. Here, we propose two ways of decomposition of the total measurement uncertainty additively into quantum and classical parts. In the two decompositions, the total uncertainty of a measurement described by a positive-operator-valued measure (POVM) over a quantum state is quantified respectively by two generalized nonadditive entropies of the measurement outcomes; the quantum parts are identified, respectively, by the nonreality and the nonclassicality—which captures simultaneously both the nonreality and negativity—of the associated generalized Kirkwood–Dirac quasiprobability relative to the POVM of interest and a projection-valued measure and maximized over all possible choices of the latter; and, the remaining uncertainties are identified as the classical parts. Both decompositions are shown to satisfy a few plausible requirements. The minimum of the total measurement uncertainties in the two decompositions over all POVM measurements are given by the impurity of the quantum state quantified by certain generalized quantum entropies, and are entirely classical. We argue that nonvanishing genuine quantum uncertainty in the two decompositions are sufficient and necessary to prove quantum contextuality via weak measurement with postselection. Finally, we suggest that the genuine quantum uncertainty is a manifestation of a specific measurement disturbance.
Dynamic facade potential for indoor lighting uniformity
Authors: Purnama M S S , Rahayu R L
Published: October 2024

The facade is an important part of a building. Its existence affects the comfort of the users. the situation outside the building is often unfavorable for the users, so the facade must be reliable as a protective element. the tropical climate receives an abundance of sunlight throughout the year. its rays can be used for natural lighting. But the rays also carry heat, which makes it uncomfortable. the entry of sunlight can be controlled. one possibility is to make the facade elements move following the sun’s movement. The aim of this research is to compare the performance of static and dynamic facades in terms of the uniformity of light entering the room. The value of lighting uniformity in condition 1 has a relatively small. This is due to the high intensity of light entering the room without obstruction resulting in high contrast Condition 2 uses a static facade. The value obtained is higher in comparison with condition 1. This is due to the presence of a shade that makes the light contrast not occur too large. Condition 3 uses a shade that rotates with the sun movement every hour. The comparison value tends to decrease but, when viewed, the value of the decrease is not as fast as condition 2. Judging from the three facade conditions, condition 3, namely the dynamic facade, has the smallest decrease in lighting uniformity. This demonstrated that the longest lighting uniformity occurs in condition 3
Enhancing Outdoor Thermal Comfort with Shade-giving Trees in Humid Tropical Public Spaces: A Case Study of Alun-alun Bandung
Authors: Priandani Imas Nurrahmah , Bachtiar Amira Nuha , Arbadiennaya Tsalsa , Noviana Nur Zastri , Hasanah Arifatul , Rania Putri , Ningtyas Amelia Dewi Safitra , Koerniawan Mochamad Donny
Published: October 2024

Public spaces in urban areas function as places for visitors to socialize. These spaces are vital to the success of urban public activities. Adjustments to the microclimate in outdoor spaces have a significant impact on the thermal comfort of visitors. This research aims to assess visitors’ level of thermal comfort experienced in public areas, specifically in Alun-alun Kota Bandung and its surroundings. The site is divided into four distinct locations: (1) the central area; (2) the tree-shaded area; (3) the building-shaded area; and (4) the area with small vegetation. This study uses tools and simulation to analyze the relationship between outdoor activities and thermal comfort in its existing public space using quantitative methods. The study’s findings show that, while respondent responses vary across typologies, an analysis of the ENVI-met simulation reveals that they are nearly identical, indicating that it is generally warm. Furthermore, the slightly cool (-1 > PMV > -0.5) and neutral (-0.5 > PMV > 0.5) categories in typologies 2 and 4 produce distinct results. More shade-giving trees and the use of environmentally friendly materials that don’t reflect sunlight are two suggestions for enhancing the microclimate conditions for pedestrians’ thermal comfort in Alun-alun Kota Bandung.
Comparing the Effectiveness of Dynamic Facades for Natural Daylight and Energy Usage in Buildings
Authors: Budhiman N H N , Koerniawan M D
Published: October 2024

In this research, we explore the integration of dynamic facades to enhance both aesthetics and energy efficiency in buildings. The study introduces two dynamic facade designs, one employing a triangular shape and the other inspired by origami folds, aiming to compare their effectiveness in optimising natural daylight and overall energy usage. The triangular facade features movable wings that dynamically regulate natural light, balancing visual appeal and practical functionality. Similarly, the origami-inspired design adapts to external conditions, creating a symbiotic relationship between form and function. The research employs Python and Rhino 7 with Honeybee and Pollination plug-ins for a comparative analysis. The evaluation includes Spatial Daylight Autonomy (sDA300,50) exceeding 55%, Annual Sunlight Exposure (ASE1000,250) no more than 10%-20%, and optimal facade opening angles based on daylight factor (df) values. The dynamic facades are examined for their impact on energy efficiency, encompassing factors like natural daylight, and operational energy. Through this analysis, the study aims to determine which dynamic facade design, triangular or origami-inspired, proves superior in optimising natural daylighting and overall energy usage. This research contributes valuable insights into the balance of innovative architectural designs and sustainable energy practices, potentially influencing future building designs.
The density effect on disposable mask waste as an acoustic absorber material
Authors: Febriyanti Dinda , Arifa Sakha Lunalaylia , Aryani Silfia Mona , Priliana Silmi Cahya Pradini
Published: October 2024

Mask ability in absorbing sound has been proven as it increases in line with thickness adding. Another characteristic that can optimize the absorption is density. This article aims to study the effect of mask density on the sound-absorption capability. This research was conducted by making absorber material models made of masks from two different brands. In the model making, this research uses two types of masks, the folded peach-colored folded face mask black duckbill type which are arranged up to 2.5 cm in thickness. In that thickness, the folded peach mask has 254 kg/m3 density and the black mask has 305 kg/m3 density. The analysis is carried out using the tube method. The research results show that at a frequency of 400 Hz, the folded peach mask has the highest absorption coefficient of 0.70, whereas the black mask has an absorption coefficient of 0.48. There is a significantly reduced absorption coefficient at the 600 Hz frequency that makes the mask not meet the standard. It can be concluded that the mask material can be used as an acoustic material as it meets the acoustic standard on absorption coefficient of at least 0.3. These findings support previous research on the potency of mask waste as an acoustic material. Therefore, the absorber material from used mask could be a solution to reduce non-degradable waste.
The Design Strategy for Youth Center in Medan Using Combination of Green Building and Contemporary Tropical Architectural Concept
Authors: Devira S , Fitri I
Published: October 2024

Medan currently lacks a Youth Centre, which forces young people to use inappropriate facilities. Therefore, the government should construct a facility to address the issue. The government prioritizes building facilities that are inexpensive to operate and maintain. The study investigates a youth centre concept in Medan by combining the green building concept and contemporary tropical architecture achieved through literature studies, interviews, and the distribution of a questionnaire to local experts and young people. The paper highlights the advantages of the green building concept and the design strategy that contributes to reducing negative impacts on the natural environment by using less energy, renewable energy sources, and environmentally friendly materials. Based on the results of interviews and questionnaires, the design should provide opportunities for young people to engage in both academic and non-academic activities that cater to their talents and interests. The research found eco-friendly technologies such as a hybrid cooler air conditioning system, solar panels, rainwater harvesting systems, floating boxes, and lighting devices that utilize motion sensors. Furthermore, it was combined to feature contemporary tropical architecture, with an overhanging roof, a double facade facing north and west, and the longest side facing south.
Comparison of Indoor Climate between Wooden wall Construction and Concrete Wall Construction during Winter Season
Authors: Nursiam T M , Kusuma Y , Syaudina A , rong J , Nabila D R , Nastiti K S
Published: October 2024

This research aims to determine the importance of thermal comfort in buildings, especially residential houses, with a focus on two types of houses that have different structures as a comparison. The research also focuses on productive rooms that are frequently used every day, considering the long duration of use. Data collection methods include distributing questionnaires to residents, as well as a quantitative approach using experiments and thermal measurements of temperature and humidity in each room, including surface measurements to compare the two types of buildings. The analysis results show that there are differences in thermal comfort between the two types of houses. Houses with wooden construction show relative humidity that reaches a comfortable point (45-65%), while houses with concrete construction tend to move cold temperatures from outside to indoors more quickly. Although efforts have been made to achieve thermal comfort in every room, the main challenge remains related to the energy consumption of artificial comfort systems. The study location in Japan took into account the different outdoor temperature variations each season. The findings we got were that houses with wooden construction walls tend to be warmer due to several factors, one of which is that this building is an apartment type with openings that tend to be smaller compared to buildings with wooden construction walls which are a traditional Japanese house type with wide openings. The measurement results using PMV analysis for both buildings were measured at 2 times at the same time, namely during the day and at night. Measurements were carried out in the living room as a comparison room with the function of a room that has the same user interaction between the two buildings. Honjo Nishi Danci Apartment (concrete wall construction) has a comfort level in the quite comfortable category compared to the living room in the apartment. Kitakyushu Islamic Cultural Center (wooden wall construction). Data was taken when both buildings did not turn on the air conditioner so that the data taken could be comparable. At night, the conditions in the living room have a slightly warm sensation because the user uses air conditioning in the room because the user sleeps in this room. the conditions in the living room at the Islamic Cultural Center have a cold sensation due to the lack of activity and use of this room. So the sensation at night tends to be cold. These findings can guide building designers in developing architectural solutions that are sustainable and focused on indoor comfort in winter.