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>

A Swimming Hydroponic System for Leafy Vegetable Production (ZAAS-SwimHydro)

Zhi-hao Xu,Wei-shon Shou,Cheng-hao Zhang,Wen-qi Dong,Jue-li Lei,Jian Cheng,Sheng-jun Zhou,Yu-qian Zhu,Dang-li Dai,Li-ping Cheng,Jian Xu,Jin-chun Fang,Sang Gyu Lee,Myeong-Cheoul Cho 한국원예학회 2008 한국원예학회 기타간행물 Vol.- No.-

Influence of Water Molecules on Polarization Behavior and Time–Frequency Dielectric Properties of Cellulose Insulation

Wen Hao,Cheng Lin,Jiang Yi,Zhu Taiyun,Chen Zhong,Dai Xize,Gao Chenyu 대한전기학회 2021 Journal of Electrical Engineering & Technology Vol.16 No.3

Oil-immersed power transformer plays an important role in power transmission and transformation engineering. Moisture is one of the important factors to determine its insulation performance. Molecular simulation technique is used to study the mechanism of water molecules on the micro polarization behavior of cellulose insulation materials. The number of hydrogen bonds, solubility parameters, total dipole moment and polarizability are analyzed. These characteristics explain the action mechanism of water molecules on cellulose insulation. At the same time, the time domain and frequency dielectric response of cellulose insulation materials with diff erent moisture content are explored. The dielectric modulus spectrum is introduced to replace the traditional frequency dielectric spectroscopy to characterize the micro relaxation process of cellulose insulation under diff erent moisture content. Finally, the characteristic parameters are extracted from the polarization, depolarization current and dielectric modulus spectrum curves to evaluate the moisture content of cellulose insulation materials. The results show that the number of hydrogen bonds, binding energy density, solubility parameter, total dipole moment and polarizability increase with the increase of water content. It should be noted that dielectric modulus spectroscopy can eff ectively characterize the relaxation behavior of cellulose insulation materials. The moisture content of cellulose insulation can be quantitatively evaluated by DC conductivity, insulation resistance, imaginary part relaxation peak of dielectric modulus and integral value of real part and imaginary part of dielectric modulus.

13.56㎒ RFID 시스템의 모드별 인식속도 비교

제영대(Young-Dai Je),양훈기(Hoon-Gee Yang),양성현(Sunghyun Yang),권성호(Cheng-Hao Quan),최길영(Gil-Young Choi) 한국통신학회 2009 韓國通信學會論文誌 Vol.34 No.7C

본 논문은 13.56㎒ 대역 RFID 시스템의 국제표준으로 되어 있는 ISO 18000-3의 전송 모드인 ASK 모드와 PJM 모드의 인식속도를 분석하고 시뮬레이션에 의해 검증한다. 이를 위해 태그 개수에 연동하여 Q값을 설정하는 최적의 Q-알고리즘을 적용시키며 이에 근거한 리더 태그 간 통신을 통해서 주워진 태그 개수에 따라서 이들을 읽는데 소요되는 슬롯 개수를 수학적으로 유도한다. 특히 유도된 이론적 수식을 적용시켜 멀티채널을 사용하는 PJM 모드와 ASK 모드의 속도를 비교하며 각각의 모드 동작을 시뮬레이션 하여 이론적인 비교 결과의 타당성을 검증한다. This paper presents the theoretical tag-reading speed in the ASK and the PJM mode of a 13.56㎒ RFID system which have been adopted in the international standard ISO 18000-3, along with simulation results to support the mathematical analysis. Through the analysis using the number of tag-dependent Q-algorithm, which was known to give relatively fast reading speed, we not only derive the number of slots to read out given tags, but compare the reading speeds of the ASK with that of the PJM mode. Moreover, we present the numerical comparison of two modes which bring the equivalent results as in the theoretical one.

Intravenous Tenecteplase for Acute Ischemic Stroke Within 4.5–24 Hours of Onset (ROSE-TNK): A Phase 2, Randomized, Multicenter Study

Wang Lu,Dai Ying-Jie,Cui Yu,Zhang Hong,Jiang Chang-Hao,Duan Ying-Jie,Zhao Yong,Feng Ye-Fang,Geng Shi-Mei,Zhang Zai-Hui,Lu Jiang,Zhang Ping,Zhao Li-Wei,Zhao Hang,Ma Yu-Tong,Song Cheng-Guang,Zhang Yi,Ch 대한뇌졸중학회 2023 Journal of stroke Vol.25 No.3

Background and Purpose Intravenous tenecteplase (TNK) efficacy has not been well demonstrated in acute ischemic stroke (AIS) beyond 4.5 hours after onset. This study aimed to determine the effect of intravenous TNK for AIS within 4.5 to 24 hours of onset. Methods In this pilot trial, eligible AIS patients with diffusion-weighted imaging (DWI)-fluid attenuated inversion recovery (FLAIR) mismatch were randomly allocated to intravenous TNK (0.25 mg/kg) or standard care within 4.5–24 hours of onset. The primary endpoint was excellent functional outcome at 90 days (modified Rankin Scale [mRS] score of 0–1). The primary safety endpoint was symptomatic intracranial hemorrhage (sICH). Results Of the randomly assigned 80 patients, the primary endpoint occurred in 52.5% (21/40) of TNK group and 50.0% (20/40) of control group, with no significant difference (unadjusted odds ratio, 1.11; 95% confidence interval 0.46–2.66; <i>P</i>=0.82). More early neurological improvement occurred in TNK group than in control group (11 vs. 3, <i>P</i>=0.03), but no significant differences were found in other secondary endpoints, such as mRS 0–2 at 90 days, shift analysis of mRS at 90 days, and change in National Institutes of Health Stroke Scale score at 24 hours and 7 days. There were no cases of sICH in this trial; however, asymptomatic intracranial hemorrhage occurred in 3 of the 40 patients (7.5%) in the TNK group. Conclusion This phase 2, randomized, multicenter study suggests that intravenous TNK within 4.5–24 hours of onset may be safe and feasible in AIS patients with a DWI-FLAIR mismatch.

13.56MHz RFID 시스템의 모드별 인식속도 비교

제영대,양훈기,양성현,권성호,최길영,Je, Young-Dai,Yang, Hoon-Gee,Yang, Sung-Hyun,Quan, Cheng-Hao,Choi, Gil-Young 한국통신학회 2009 韓國通信學會論文誌 Vol.34 No.7C

본 논문은 13.56MHz 대역 RFID 시스템의 국제표준으로 되어 있는 ISO 18000-3의 전송 모드인 ASK 모드와 PJM 모드의 인식속도를 분석하고 시뮬레이션에 의해 검증한다. 이를 위해 태그 개수에 연동하여 Q값을 설정하는 최척의 Q-알고리즘을 적용시키며 이에 근거한 리더 태그 간 통신을 통해서 주워진 태그 개수에 따라서 이들을 읽는데 소요되는 슬롯 개수를 수학적으로 유도한다. 특히 유도된 이론적 수식을 적용시켜 멀티채널을 사용하는 PJM 모드와 ASK 모드의 속도를 비교하며 각각의 모드 동작을 시뮬레이션 하여 이론적인 비교 결과의 타당성을 검증 한다. This paper presents the theoretical tag-reading speed in the ASK and the PJM mode of a 13.56MHz RFID system which have been adopted in the international standard ISO 18000-3, along with simulation results to support the mathematical analysis. Through the analysis using the number of tag-dependent Q-algorithm, which was known to give relatively fast reading speed, we not only derive the number of slots to read out given tags, but compare the reading speeds of the ASK with that of the PJM mode. Moreover, we present the numerical comparison of two modes which bring the equivalent results as in the theoretical one.

Transcriptome analysis of flower colour reveals the correlation between SNP and differential expression genes in Phalaenopsis

Ding Yu,Wang Ma-Yin,Yang Ding-Hai,Hao Dai-Cheng,Li Wei-Shi,Ling Peng,Xie Shang-Qian 한국유전학회 2023 Genes & Genomics Vol.45 No.12

Background Phalaenopsis is an important ornamental plant that has great economic value in the world flower market as one of the most popular flower resources. Objective To investigate the flower colour formation of Phalaenopsis at the transcription level, the genes involved in flower color formation were identified from RNA-seq in this study. Methods In this study, white and purple petals of Phalaenopsis were collected and analyzed to obtained (1) differential expression genes (DEGs) between white and purple flower color and (2) the association between single nucleotide polymorphisms (SNP) mutations and DEGs at the transcriptome level. Results The results indicated that a total of 1,175 DEGs were identified, and 718 and 457 of them were up- and down-regulated genes, respectively. Gene Ontology and pathway enrichment showed that the biosynthesis of the secondary metabolites pathway was key to color formation, and the expression of 12 crucial genes (C4H, CCoAOMT, F3’H, UA3’5’GT, PAL, 4CL, CCR, CAD, CALDH, bglx, SGTase, and E1.11.17) that are involved in the regulation of flower color in Phalaenopsis. Conclusion This study reported the association between the SNP mutations and DEGs for color formation at RNA level, and provides a new insight to further investigate the gene expression and its relationship with genetic variants from RNA-seq data in other species.