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>

Pre-zygotic Embryological Characters of Platycrater arguta, a Rare and Endangered Species Endemic to East Asia

( Cheng Qi Ao ) 한국식물학회 2008 Journal of Plant Biology Vol.51 No.2

Platycrater arguta Sieb. et Zucc. is a rare and endangered species endemic to East Asia. It produces two floral morphs viz. bisexual and male flowers. For bisexual flowers, simultaneous cytokinesis in the microsporocyte meiosis leads to a tetrahedral tetrad. The mature pollen grain is shed at 2-cell stage. The young anther wall is composed of epidermis, endothecium that develops fibrous thickenings at maturity, 1-2 middle layers and tapetum. The tapetum with uninucleate to binucleate cells, disintegrates in situ (glandular tapetum), yet in a small percentage of the anthers (about 37.6%), the tapetum does not disintegrate, causing complete male sterility. The ovules are anatropous, unitegmic, tenuinucellar and the formation of the embryo sac follows the monosporic, Polygonum type. Antipodal cells are lacking in the mature embryo sacs. Before fertilization, two polar nuclei fuse into a secondary nucleus. The formation of microsporangial wall, microsporogenesis and male gametogenesis in male flowers are analogous to those in the bisexual. Prezygotic embryological characters of P. arguta were reported for the first time, revealing that its endangerment is correlated with the abortion of pollen of a part, but not to the female development that is normal.

Morphological Characters of Leaf Epidermis in Schisandraceae and Their Systematic Significance

( Cheng Qi Ao ) 한국식물학회 2006 Journal of Plant Biology Vol.49 No.1

Exploring computer vision and artificial intelligence-based distance measurement tools for the standing long jump

Cheng Jiang(강성),Jia-Qi Sun(손가기),Ke-Xin Qi(기가심),Xue Jiang(강설),Xiangchuan Jin(김향천),Xuanshang Jin(김현상) 한국체육측정평가학회 2022 한국체육측정평가학회지 Vol.24 No.1

이 연구에서 제자리 멀리뛰기의 측정 범위에 대한 핵심 기술은 주로 두 가지의 단계를 거친다. 첫 번째 단계는 환경 초기화 단계로, 주로 제자리 멀리뛰기의 필드, 카메라 및 인체의 핵심 지점의 정량적 식별을 포함한다. 두 번째 단계는 범위 설정 단계로 카메라의 점프 프레임과 착지 프레임의 적정 세트를 추출하고 발가락과 발뒤꿈치 영역 또는 범위의 핵심 포인트를 식별하는 것으로 구성된다. 이 연구의 목적을 달성하기 위해서 총 20회의 제자리 멀리 뛰기 동작을 측정하였으며 정확도를 평가한 결과 측정 오차는 0.58cm, 표준편차는 0.24로 나타났다. 따라서 이 연구는 제자리 멀리뛰기 동작의 결과에 대한 오차를 1㎝ 이내로 조절할 수 있다는 것이 입증되었으며, 이는 곧 높은 정확도를 지닌 도구로서 판단된다. 또한 이 연구는 일반적인 웹캠을 사용하기 때문에 다른 제자리 멀리뛰기 검사 방식에 비해 장비의 가격이 저렴하고, 유지비용 또한 부담을 덜어줌과 동시에 높은 지능을 가지고 있는 도구라는 장점이 있다. 따라서 이 연구 결과를 통해 널리 보급되는 것을 기대할 수 있다. The key technology of standing long jump ranging in this study are mainly manifested in two stages: the first stage is the environment initialization stage, which mainly includes the quantitative identification of standing long jump field, camera and human body key points; the second stage is the ranging stage, which consists of extracting the set of jump frame and landing frame and identifying the key points of toe and heel. After the evaluation of test accuracy, the measurement is conducted 20 times, the error is 0.58cm, and the standard deviation is 0.24. It is proved that this study can control the error of standing long jump test results within 1cm, which shows that the research results have high test accuracy. Because this study uses an ordinary webcam, compared with other standing long jump test methods, it has the advantages of higher intelligence, low price and low maintenance cost. The research results are easy to be widely popularized.

Reviews on Customer Knowledge Management Researches

Qi-cheng Lu,Wei Feng 한국산업정보학회 2007 한국산업정보학회 학술대회논문집 Vol.2007 No.3

Optogenetic Rescue of Locomotor Dysfunction and Dopaminergic Degeneration Caused by Alpha-Synuclein and EKO Genes

Cheng Qi,Scott Varga,오수진,이창준,이대우 한국뇌신경과학회 2017 Experimental Neurobiology Vol.26 No.2

α-Synuclein (α-Syn) is a small presynaptic protein and its mutant forms (e.g. A53T) are known to be directly associated with Parkinson’s disease (PD). Pathophysiological mechanisms underlying α-Syn-mediated neurodegeneration in PD still remain to be explored. However, several studies strongly support that overexpression of mutant α-Syn causes reduced release of dopamine (DA) in the brain, and contributes to motor deficits in PD. Using a favorable genetic model Drosophila larva, we examined whether reduced DA release is enough to induce key PD symptoms (i.e. locomotion deficiency and DA neurodegeneration), mimicking a PD gene α-Syn. In order to reduce DA release, we expressed electrical knockout (EKO) gene in DA neurons, which is known to make neurons hypo-excitable. EKO led to a decrease in a DA neuronal marker signal (i.e., TH – tyrosine hydroxylase) and locomotion deficits in Drosophila larva. In contrast, acute and prolonged exposure to blue light (BL, 470 nm) was sufficient to activate channelrhodopsin 2 (ChR2) and rescue PD symptoms caused by both α-Syn and EKO. We believe this is for the first time to confirm that locomotion defects by a genetic PD factor such as α-Syn can be rescued by increasing DA neuronal excitability with an optogenetic approach. Our findings strongly support that PD is a failure of DA synaptic transmission, which can be rescued by optogenetic activation of ChR2.

건강과 방사선 손상에 대한 효과

Cheng Qi Kun,Wang Yun Hao 한국식품과학회 1995 국제녹차심포지엄 Vol.1995 No.1

FEM analysis of the modular prefabricated steel-concrete composite beam-column internal joint under reciprocating action

Cheng Long Wu,Jian Cheng Kan,Qi Hui Wang,Ji Ming Liu,Zun Qiang Li 국제구조공학회 2021 Steel and Composite Structures, An International J Vol.41 No.1

Prefabricated steel-concrete composite structure has the advantages of large bearing capacity, reliable connection, and good durability, which is of great significance to the development of building industrialization. In this paper, a finite element model (FEM) of the modular prefabricated SRC column-steel beam composite joint is established and verified its accuracy through ABAQUS. The effects of various parameter variables on the hysteresis curve, skeleton curve, ductility, energy consumption, and performance deterioration are investigated. The results show that as the axial compression ratio increases, the joint bearing capacity first increases and then decreases, the strength and stiffness have relatively stable degradation characteristics. However, the hysteresis curve has a certain “pinch” phenomenon, which reduces the energy consumption performance. Different column end bolts margin and apertures have little effect on the bearing capacity, strength and stiffness degradation performance, but affect energy consumption and ductility. The width-to-thickness ratio of the square steel tube has a greater impact on the bearing capacity, energy consumption and ductility, and has less impact on the strength and stiffness degradation performance. As the thickness of the joint cover plate increases, the bearing capacity, energy consumption and initial stiffness of the joint gradually increase, the ductility first increases and then decreases.

First record of the subgenus Tipula (Ramatipula) (Diptera, Tipulidae) from China, with description of two new species

Yang Qi-Cheng,Zhang Bing,Liu Xiao-Yan,Yang Ding 한국응용곤충학회 2022 Journal of Asia-Pacific Entomology Vol.25 No.2

The subgenus Ramatipula Alexander, 1971 of the genus Tipula is recorded for the first time in China. Two new species, Tipula (Ramatipula) dolabcorolla, sp. nov., and Tipula (Ramatipula) spathulata, sp. nov. are described and illustrated. A key to the species of Tipula (Ramatipula) from the world is presented. urn:lsid:zoobank.org:pub:405A10AD-9C5E-4D81-A04B-403D96A286EC.

On The Size of The Subgroup Generated by Linear Factors

취쳉(Qi Cheng),황선태(Suntae Hwang) 대한전자공학회 2008 電子工學會論文誌-TC (Telecommunications) Vol.45 No.6

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