A Survey of Gesture Recognition Using Frequency Modulated Continuous Wave Radar

With technology advances and human requirements increasing, human-computer interaction plays an important role in our daily lives. Among these interactions, gesture-based recognition offers a natural and intuitive user experience that does not require physical contact and is becoming increasingly prevalent across various fields. Gesture recognition systems based on Frequency Modulated Continuous Wave (FMCW) millimeter-wave radar are receiving widespread attention due to their ability to operate without wearable sensors, their robustness to environmental factors, and the excellent penetrative ability of radar signals. This paper first reviews the current main gesture recognition applications. Subsequently, we introduce the system of gesture recognition based on FMCW radar and provide a general framework for gesture recognition, including gesture data acquisition, data preprocessing, and classification methods. We then discuss typical applications of gesture recognition systems and summarize the performance of these systems in terms of experimental environment, signal acquisition, signal processing, and classification methods. Specifically, we focus our study on four typical gesture recognition systems, including air-writing recognition, gesture command recognition, sign language recognition, and text input recognition. Finally, this paper addresses the challenges and unresolved problems in FMCW radar-based gesture recognition and provides insights into potential future research directions.

Negligible normal fluid in superconducting state of heavily overdoped Bi_(2)Sr_(2)CaCu_(2)O_(8+δ) detected by ultra-low temperature angle-resolved photoemission spectroscopy

In high temperature cuprate superconductors,it was found that the superfluid density decreases with the increase of hole doping.One natural question is whether there exists normal fluid in the superconducting state in the overdoped region.In this paper,we have carried out high-resolution ultra-low temperature laser-based angle-resolved photoemission measurements on a heavily overdoped Bi2212 sample with a T_(c) of 48 K.We find that this heavily overdoped Bi2212 remains in the strong coupling regime with 2Δ_(0)/(k_(B)T_(c))=5.8.The single-particle scattering rate is very small along the nodal direction(~5 meV) and increases as the momentum moves from the nodal to the antinodal regions.A hard superconducting gap opening is observed near the antinodal region with the spectral weight at the Fermi level fully suppressed to zero.The normal fluid is found to be negligibly small in the superconducting state of this heavily overdoped Bi2212.These results provide key information to understand the high T_(c) mechanism in the cuprate superconductors.

From beasts to bytes:Revolutionizing zoological research with artificial intelligence

Since the late 2010s,Artificial Intelligence(AI)including machine learning,boosted through deep learning,has boomed as a vital tool to leverage computer vision,natural language processing and speech recognition in revolutionizing zoological research.This review provides an overview of the primary tasks,core models,datasets,and applications of AI in zoological research,including animal classification,resource conservation,behavior,development,genetics and evolution,breeding and health,disease models,and paleontology.Additionally,we explore the challenges and future directions of integrating AI into this field.Based on numerous case studies,this review outlines various avenues for incorporating AI into zoological research and underscores its potential to enhance our understanding of the intricate relationships that exist within the animal kingdom.As we build a bridge between beast and byte realms,this review serves as a resource for envisioning novel AI applications in zoological research that have not yet been explored.

Relationship between pore structure and hydration activity of CaO from carbide slag

CaO needs to show high activity to be used as Ca-sorbent and slagging agent. Hydration activity is an important characteristic to evaluate the activity of CaO. In this study, carbide slag from polyvinyl chloride(PVC) industry was utilized as precursor for preparing high activity CaO. The roles of crystallite grain, average pore diameter(APD) and volume fraction of pore b 200 nm in diameter(VF200) in hydration activity of CaO from carbide slag(CS-CaO)were respectively investigated. The hydrolysis kinetics model of CaO shows a three-dimensional spherically symmetric diffusion model(D4), which suggests that hydration activity was mainly associated with APD and VF200 of CS-CaO with limited correlation to the crystal size. Specifically, the hydration activity of CS-CaO is increased with increasing VF200, while decreased with increasing APD. Under the invariable calcination temperature,the core–shell structure formed by the addition of graphite or Ca CO3 to CS effectively inhibits the sintering of CS-CaO and improves VF200. Consequently, the hydration activity of CS-CaO increased from 22.79 ℃·min^-1 to27.19 ℃·min^-1 and to 29.27 ℃·min^-1, with addition of 5% graphite or 5% CaCO3 into carbide slag, respectively.

Electrochemical behaviors of anode materials and their performance for bauxite desulfurization

Pyrite inside bauxite could be oxidized into soluble S-containing ions by electrolysis, and thus achieving bauxite desulfurization by using filtration. However, S-containing ions in electrolyte had some corrosion effects on electrode, especially for anode. In this work, six kinds of traditional materials were selected as anode, and their corrosion behaviors were examined by using electrochemistry characterization. Tafel and CV curves from simulating electrolyte suggested that their corrosion potentials were in the following order: Ni﹥C﹥SS﹥Fe﹥Cu﹥Pb–Ag. As expected, the desulfurization ratio and cell voltage from bauxite electrolysis were in the following order respectively: Cu﹥Ni﹥Fe﹥SS﹥C﹥Pb–Ag and Ni﹥Fe﹥SS﹥Cu﹥C﹥Pb–Ag. Finally, Ni was proposed a kind of excellent electrode material for bauxite desulfurization from electrolysis.

基于频率特征增强的结直肠息肉分割模型

早期息肉检查是防范结直肠癌发病的重要手段,针对现有基于深度学习方法依旧不能准确辨别息肉位置和边缘信息的问题,提出了一种利用傅里叶变换增强频率特征(FFENet)的息肉分割方法。具体地,在FFENet中设计了一个细节特征增强注意力模块和一个全局频率特征学习模块,前者重耦合不同深度的特征并计算三种显著性特征图来细化息肉区域及其边缘;后者在频域中引入可学习的滤波核,以增强息肉与其边缘间的连贯性并捕捉图像像素之间的长距离依赖关系。结合改善的部分解码器和自适应特征选择模块,大量实验结果表明所提出FFENet在五类息肉数据上更具优势。尤其是在ETIS数据集上,对比其他最先进的模型,大模型版本FFENet-L在Dice和IoU指标上分别提升了4%和5.5%,而小模型版本FFENet-S在保持精度相当的同时,仅仅使用了6.2M参数。

Comparison of prevention and treatment of portal vein thrombosis between proximal splenic vein ligation followed by postoperative transcatheter anticoagulant therapy and systemic anticoagulant therapy in patients with cirrhotic portal hypertension

Aims:Splenectomy combined with pericardial devascularization is one of the important methods to treat hypersplenism,gastrointestinal bleeding,and other complications caused by liver cirrhosis;however,it is accompanied by a high risk of portal vein thrombosis(PVT).This study aimed to explore the preventive and therapeutic effects of proximal splenic vein ligation(PSVL)with postoperative transcatheter anticoagulant therapy(TCAT)on PVT.Methods:This study retrospectively selected 143 patients with liver cirrhosis and portal hypertension,who received splenectomy combined with pericardial devascularization from June 30,2018 to June 30,2021.According to computed tomography photography,within 1 week before the operation,the patients were divided into a prevention group(without preoperative PVT,n=112)and a treatment group(preoperative PVT,n=31).Then,each group was subdivided based on the treatment and prevention measures into PSVL+TCAT(n=70)and systemic anticoagulant therapy(SAT)subgroups(n=73).The preventive and therapeutic effects of PSVL followed by TCAT on PVT were analyzed.Results:The operation time in the PSVL+TCAT subgroups was longer than that in the SAT subgroups(185±76 min vs.161±55 min;p<0.01).There was no difference between the two subgroups in terms of operative bleeding(345±82 mL vs.336±65 mL;p>0.50).There was no operative death,and all patients recovered uneventfully.In the prevention group,procedure-related complications occurred in two patients in the PSVL+TCAT subgroup(3.7%[2/54]),including one patient with slight pancreatitis and one patient with chylous leakage,owing to mobilization of the pancreas.The PVT incidence in the prevention group was significantly different between the two subgroups at postoperative 7th day,3rd month,and 6th month(PSVL+TCAT:0%,11.1%,and 5.6%vs.SAT:39.7%,31.0%,and 20.7%,respectively;all p<0.05).In the treatment group,the thrombus regression rate at postoperative 7th day and disappearance rates at the 3rd month and the 6th month of the PSVL+TCAT subgroup were significantly higher than those in the SAT subgroup after anticoagulant and thrombolysis therapy(PSVL+TCAT:75.0%,68.8%,and 87.5%vs.SAT:20.0%,26.7%,and 40.0%;all p<0.05).Conclusions:PSVL+TCAT reduces the risk of PVT after splenectomy and is safe and effective in treating PVT during surgery for portal hypertension.

微生物教学实验室中不同有效成分洗手/消毒液对手卫生效果的比较分析

目的评估不同手部抑菌消毒产品对微生物实验室操作人员手部清洁的效果。方法微生物实验室工作人员分别使用含有不同主要抑菌成分的洗手液/消毒液对手部进行消毒处理,对消毒前后培养出的菌落样本进行菌落种类计数、革兰染色和生化、药敏鉴定,并对检验结果进行整合、对比和分析。结果在所研究的实验条件下,主要成分为63%-75%(V/V)乙醇和0.45%-0.55%(W/N)醋酸氯己定的品牌8对大多数细菌有着良好的消毒效果;主要抑菌成分为0.18%-0.22%(W/W)对氯间二甲苯酚的品牌6和0.18%-0.22%(W/W)吡罗克酮乙醇胺盐的品牌7的消毒效果相对较差。含0.27%-0.33%(W/W)水杨酸的品牌5和含0.32%-0.38%(W/W)水杨酸的品牌1对特定菌种有较好的消毒效果;含0.000126%-0.000154%(W/W)银离子的品牌2效果较一般,而无抑菌成分的洗手液对大多数菌种皆无明显抑制作用。结论在所研究的微生物实验室条件下,主要成分为63%-75%(V/V)乙醇和0.45%-0.55%(W/N)醋酸氯己定的免洗消毒液抑菌效果最好,不同品牌洗手液的效果均不如免洗消毒液,且洗手/消毒程序不影响免洗消毒液的抑菌效果。

电场对CaO-SiO2-Al2O3熔渣的结构调控

针对硅中硼难去除的问题,从熔渣结构层面进行研究,通过观察熔渣不同部位在不同电场条件下熔渣结构的变化,分析不同电场条件下高温骤冷所得熔渣结构变化,探索引入电场对熔渣结构影响。结果表明,引入电场会引起熔渣中离子定向移动与重新分配,改变熔渣结构。熔渣上部结构在电场作用下解聚更彻底,远离渣金界面处熔渣结构变化较小。电场增强有利于熔渣解聚,电场强度达10V时,熔渣中结构单元会转变为聚合度更低的Q0结构单元。熔渣上部结构对电场变化更敏感,电场改变,熔渣下部结构变化较小。