Full-space Cloud of Random Points with a Scrambling Metasurface

Li, Zile,Dai, Qi,Mehmood, Muhammad Q.,Hu, Guangwei,yanchuk, Boris Luk’,Tao, Jin,Hao, Chenglong,Kim, Inki,Jeong, Heonyeong,Zheng, Guoxing,Yu, Shaohua,Alù,, Andrea,Rho, Junsuk,Qiu, Cheng-Wei Nature Publishing Group UK 2018 Light, science & applications Vol.7 No.1

<▼1><P>With the rapid progress in computer science, including artificial intelligence, big data and cloud computing, full-space spot generation can be pivotal to many practical applications, such as facial recognition, motion detection, augmented reality, etc. These opportunities may be achieved by using diffractive optical elements (DOEs) or light detection and ranging (LIDAR). However, DOEs suffer from intrinsic limitations, such as demanding depth-controlled fabrication techniques, large thicknesses (more than the wavelength), Lambertian operation only in half space, etc. LIDAR nevertheless relies on complex and bulky scanning systems, which hinders the miniaturization of the spot generator. Here, inspired by a Lambertian scatterer, we report a Hermitian-conjugate metasurface scrambling the incident light to a cloud of random points in full space with compressed information density, functioning in both transmission and reflection spaces. Over 4044 random spots are experimentally observed in the entire space, covering angles at nearly 90°. Our scrambling metasurface is made of amorphous silicon with a uniform subwavelength height, a nearly continuous phase coverage, a lightweight, flexible design, and low-heat dissipation. Thus, it may be mass produced by and integrated into existing semiconductor foundry designs. Our work opens important directions for emerging 3D recognition sensors, such as motion sensing, facial recognition, and other applications.</P></▼1><▼2><P><B>Metasurfaces: scrambling light for 3D detection and recognition</B></P><P>Firing light at a manufactured 'metasurface'—one carrying patterns at a smaller scale than the wavelength of the light—fills large volumes of space with defined points of light, potentially improving 3-D recognition and sensor applications. Cheng-Wei Qui and colleagues at the National University of Singapore, with co-workers across Asia and in the USA, created their unique metasurface from amorphous silicon. Light is scattered from and transmitted through the material to generate a cloud of data points in the surrounding space in which the structure and motion of objects under study can be analyzed. The initial development work with this “scrambling metasurface” suggests it could improve pattern recognition, including face recognition, motion detection and augmented reality applications. The researchers describe how their innovation overcomes significant limitations of existing methods in these fields.</P></▼2>

Adaptive Range-Based Collision Avoidance MAC Protocol in Wireless Full-duplex Ad Hoc Networks

( Yu Song ),( Wangdong Qi ),( Wenchi Cheng ) 한국인터넷정보학회 2019 KSII Transactions on Internet and Information Syst Vol.13 No.6

Full-duplex (FD) technologies enable wireless nodes to simultaneously transmit and receive signal using the same frequency-band. The FD modes could improve their physical layer throughputs. However, in the wireless ad hoc networks, the FD communications also produce new interference risks. On the one hand, the interference ranges (IRs) of the nodes are enlarged when they work in the FD mode. On the other hand, for each FD pair, the FD communication may cause the potential hidden terminal problems to appear around the both sides. In this paper, to avoid the interference risks, we first model the IR of each node when it works in the FD mode, and then analyze the conditions to be satisfied among the transmission ranges (TRs), carrier-sensing ranges (CSRs), and IRs of the FD pair. Furthermore, in the media access control (MAC) layer, we propose a specific method and protocol for collision avoidance. Based on the modified Omnet++ simulator, we conduct the simulations to validate and evaluate the proposed FD MAC protocol, showing that it can reduce the collisions effectively. When the hidden terminal problem is serious, compared with the existing typical FD MAC protocol, our protocol can increase the system throughput by 80%~90%.

Sulfur-free exfoliated graphite with large exfoliated volume: Preparation, characterization and its adsorption performance

Qi Zhao,Xiujuan Yu,Xiuwen Cheng,Juan Wu 한국공업화학회 2014 Journal of Industrial and Engineering Chemistry Vol.20 No.6

Sulfur-free exfoliated graphite (EG) with large exfoliated volume (760 mL g-1) was prepared throughchemical oxidation, followed by microwave exfoliation. SEM results indicated that well-developednetwork pores in the worm-like structure of EG could be clearly observed. XPS results displayed thatsome functional groups were yielded on the surface of the as-prepared EG. Moreover, the capacity of EGwas evaluated by the adsorption of rodamine B and 4-chlorophenol aqueous solution. Results showedthat EG exhibited high adsorption capacity for RhB and 4-CP, which could be attributed to the functionalgroups and well-developed network pores in the worm-like EG.

Glycerol steam reforming over Ni/γ-Al2O3 catalysts modified by metal oxides

Cheng-Hua Xu,Zun-Yu Huang,Chuan-Qi Liu,Hui-Wen Xiao,Jun Chen,Yong-Xiang Zhang,Ya-Cong Lei 한국화학공학회 2013 Korean Journal of Chemical Engineering Vol.30 No.3

The metal oxides modified Ni/γ-Al2O3 catalysts for glycerol steam reforming were prepared by impregnation. Characterization results of fresh catalysts indicated that the molybdates modification abated the acidity and the stronger metal-support interaction of Ni/γ-Al2O3 catalysts, leading to a stable catalytic activity. Especially, NiMoLa-CaMg/γ-Al2O3 (NiMoLa/CMA) catalyst exhibited no deactivation along with glycerol complete conversion to stable gaseous products containing 69% H2, 20% CO and 10% CO2 during time-on-stream of 42 h. TPO of spent Ni/γ-Al2O3catalysts modified by different components showed that the carbon deposit on acidic sites and NiAl2O4 species led to catalysts deactivation. A lower reforming temperature and a higher LHSV and glycerol content were helpful to the production of syngas from GSR over NiMoLa/CMA; the reverse conditions would improve the formation of H2.

Does the Fit of Managerial Ability with Firm Strategy Matters on Firm Performance

CHENG, Teng Yuan,LI, Yue-Qi,LIN, Yu-En,CHIH, Hsiang-Hsuan Korea Distribution Science Association 2020 The Journal of Asian Finance, Economics and Busine Vol.7 No.4

The study aims to answer why the previous studies find the positive or insignificant effect of the CEO's abilities on firm performance. Using 34,285 CEO-firm-year panel data from the U.S. publicly traded firms drawn from the BoardEx and EXECUXOMP database during from 1992 to 2014, the results show that the fit of the CEO's generality or specialist ability with firm strategy matters on firm performance and risk. This study computes a discrete STRATEGY composite measure to construct firm strategy types, such as Prospect or Defend and use CEOs' résumés to construct an index of general skills that are transferable across firms and industries. The results find that generalist CEOs are more suitable for prospectors than specialist CEOs. Firm performance is much better when specialist CEOs work for Defenders. Although the firm performance is better too for the generalist CEOs who fit for the Prospect strategy, the firm's risk is up too. The result suggests that firms need to consider their chosen business strategy to recruit and select CEOs Our findings provide direct evidence that the match between CEO's ability and the firm's strategy is crucial to firm performance and risk.

Demand Response Based on Kalman-Filtering for the Frequency Control

Yu-Qing Bao,Cheng Shen,Qi Wang,Jin-Long Zhang 대한전기학회 2019 Journal of Electrical Engineering & Technology Vol.14 No.3

DR control can be incorporated with traditional frequency control methods to achieve better performance. However, in the frequency measurement process, disturbances may infl uence the precision of measured frequency, and further infl uence the control performance. In this paper, a hierarchical DR control strategy is considered for the frequency control. In order to reduce the infl uence of detection error, a Kalman-fi ltering based method is proposed. At last, the eff ectiveness of the proposed method is verifi ed by the testing results.

Causal Relations between Exposome and Stroke: A Mendelian Randomization Study

Hong-Qi Li,Yi-Wei Feng,Yu-Xiang Yang,Xin-Yi Leng,Prof Can Zhang,Shi-Dong Chen,Kevin Kuo,Shu-Yi Huang,Xue-Qing Zhang,Yi Dong,Xiang Han,Xin Cheng,Mei Cui,Lan Tan,Qiang Dong,Jin-Tai Yu 대한뇌졸중학회 2022 Journal of stroke Vol.24 No.2

Background and Purpose To explore the causal relationships of elements of the exposome with ischemic stroke and its subtypes at the omics level and to provide evidence for stroke prevention. Methods We conducted a Mendelian randomization study between exposure and any ischemic stroke (AIS) and its subtypes (large-artery atherosclerotic disease [LAD], cardioembolic stroke [CE], and small vessel disease [SVD]). The exposure dataset was the UK Biobank involving 361,194 subjects, and the outcome dataset was the MEGASTROKE consortium including 52,000 participants. Results We found that higher blood pressure (BP) (systolic BP: odds ratio [OR], 1.02; 95% confidence interval [CI], 1.01 to 1.04; diastolic BP: OR, 1.03; 95% CI, 1.01 to 1.05; pulse pressure: OR, 1.03; 95% CI, 1.00 to 1.06), atrial fibrillation (OR, 1.18; 95% CI, 1.13 to 1.25), and diabetes (OR, 1.13; 95% CI, 1.07 to 1.18) were significantly associated with ischemic stroke. Importantly, higher education (OR, 0.69; 95% CI, 0.60 to 0.79) decreased the risk of ischemic stroke. Higher systolic BP (OR, 1.06; 95% CI, 1.02 to 1.10), pulse pressure (OR, 1.08; 95% CI, 1.02 to 1.14), diabetes (OR, 1.28; 95% CI, 1.13 to 1.45), and coronary artery disease (OR, 1.58; 95% CI, 1.25 to 2.00) could cause LAD. Atrial fibrillation could cause CE (OR, 1.90; 95% CI, 1.71 to 2.11). For SVD, higher systolic BP (OR, 1.04; 95% CI, 1.00 to 1.07), diastolic BP (OR, 1.06; 95% CI, 1.01 to 1.12), and diabetes (OR, 1.22; 95% CI, 1.10 to 1.36) were causal factors. Conclusions The study revealed elements of the exposome causally linked to ischemic stroke and its subtypes, including conventional causal risk factors and novel protective factors such as higher education.

Dissipative Particle Dynamics Simulation on the Formation Process of CeO₂ Nanoparticles in Alcohol Aqueous Solutions

Zhang, Qi,Zhong, Jing,Yang, Bao-Zhu,Huang, Wei-Qiu,Chen, Ruo-Yu,Liao, Jun-Min,Gu, Chi-Ruei,Chen, Cheng-Lung Korean Chemical Society 2012 대한화학회지 Vol.56 No.4

Dissipative particle dynamics (DPD) was carried out to study the nucleation and crystal growth process of $CeO_2$ nanoparticles in different alcohol aqueous solutions. The results showed that the nucleation and crystal growth process of $CeO_2$ can be classified into three stages: nuclei growth, crystal stabilization and crystal aggregation except the initial induction stage, which could be reproduced by collecting simulation results after different simulation time. Properly selecting the sizes of $CeO_2$ and water bead was crucial in the simulation system. The influence of alcohol type and content in solutions, and precipitation temperature on the particle dimension were investigated in detail and compared with the experimental results. The consistency between simulation results and experimental data verify that the simulation can reproduce the macroscopic particle aggregation process. The effect of solvent on the nucleation and crystal growth of $CeO_2$ nanoparticles are different at three stages and can not be simply described by Derjaguin-Landau-Verwey-Overbeek (DLVO) theory or nucleation thermodynamics theory. Our work demonstrated that DPD methods can be applied to study nanoparticle forming process.

Discrimination of neutrons and gamma-rays in plastic scintillator based on spiking cortical model

Liu Bing-Qi,Liu Hao-Ran,Chang Lan,Cheng Yu-Xin,Zuo Zhuo,Li Peng 한국원자력학회 2023 Nuclear Engineering and Technology Vol.55 No.9

In this study, a spiking cortical model (SCM) based n-g discrimination method is proposed. The SCMbased algorithm is compared with three other methods, namely: (i) the pulse-coupled neural network (PCNN), (ii) the charge comparison, and (iii) the zero-crossing. The objective evaluation criteria used for the comparison are the FoM-value and the time consumption of discrimination. Experimental results demonstrated that our proposed method outperforms the other methods significantly with the highest FoM-value. Specifically, the proposed method exhibits a 34.81% improvement compared with the PCNN, a 50.29% improvement compared with the charge comparison, and a 110.02% improvement compared with the zero-crossing. Additionally, the proposed method features the second-fastest discrimination time, where it is 75.67% faster than the PCNN, 70.65% faster than the charge comparison and 38.4% slower than the zero-crossing. Our study also discusses the role and change pattern of each parameter of the SCM to guide the selection process. It concludes that the SCM's outstanding ability to recognize the dynamic information in the pulse signal, improved accuracy when compared to the PCNN, and better computational complexity enables the SCM to exhibit excellent n-g discrimination performance while consuming less time.

Efficacy and Safety of Intravenous Urapidil for Older Hypertensive Patients with Acute Heart Failure: A Multicenter Randomized Controlled Trial

Wei Yang,Qi Hua,Yu-Jie Zhou,Yan Fu,Jian Qin,Shu Qin,Xiao-Min Chen,Jin-Cheng Guo,De-Zhao Wang,Hong Zhan,Jing Li,Jing-Yu He 연세대학교의과대학 2017 Yonsei medical journal Vol.58 No.1

Purpose: Urapidil is putatively effective for patients with hypertension and acute heart failure, although randomized controlled trials thereon are lacking. We investigated the efficacy and safety of intravenous urapidil relative to that of nitroglycerin in older patients with hypertension and heart failure in a randomized controlled trial. Materials and Methods: Patients (>60 y) with hypertension and heart failure were randomly assigned to receive intravenous urapidil (n=89) or nitroglycerin (n=91) for 7 days. Hemodynamic parameters, cardiac function, and safety outcomes were compared. Results: Patients in the urapidil group had significantly lower mean systolic blood pressure (110.1±6.5 mm Hg) than those given nitroglycerin (126.4±8.1 mm Hg, p=0.022), without changes in heart rate. Urapidil was associated with improved cardiac function as reflected by lower N terminal-pro B type natriuretic peptide after 7 days (3311.4±546.1 ng/mL vs. 4879.1±325.7 ng/mL, p=0.027) and improved left ventricular ejection fraction (62.2±3.4% vs. 51.0±2.4%, p=0.032). Patients given urapidil had fewer associatedadverse events, specifically headache (p=0.025) and tachycardia (p=0.004). The one-month rehospitalization and all-cause mortality rates were similar. Conclusion: Intravenous administration of urapidil, compared with nitroglycerin, was associated with better control of blood pressure and preserved cardiac function, as well as fewer adverse events, for elderly patients with hypertension and acute heart failure.