Low Complexity Discrete Hartley Transform Precoded OFDM System over Frequency-Selective Fading Channel

Xing Ouyang,Jiyu Jin,Guiyue Jin,Peng Li 한국전자통신연구원 2015 ETRI Journal Vol.37 No.1

Orthogonal frequency-division multiplexing (OFDM) suffers from spectral nulls of frequency-selective fading channels. Linear precoded (LP-) OFDM is an effective method that guarantees symbol detectability by spreading the frequency-domain symbols over the whole spectrum. This paper proposes a computationally efficient and low-cost implementation for discrete Hartley transform (DHT) precoded OFDM systems. Compared to conventional DHT-OFDM systems, at the transmitter, both the DHT and the inverse discrete Fourier transform are replaced by a one-level butterfly structure that involves only one addition per symbol to generate the time-domain DHT-OFDM signal. At the receiver, only the DHT is required to recover the distorted signal with a single-tap equalizer in contrast to both the DHT and the DFT in the conventional DHT-OFDM. Theoretical analysis of DHT-OFDM with linear equalizers is presented and confirmed by numerical simulation. It is shown that the proposed DHT-OFDM system achieves similar performance when compared to other LP-OFDMs but exhibits a lower implementation complexity and peak-to-average power ratio.

Partial Shift Mapping for PAPR Reduction with Low Complexity in OFDM Systems

Xing Ouyang,Jiyu Jin,Guiyue Jin,Zhisen Wang 한국전자통신연구원 2012 ETRI Journal Vol.34 No.2

The high peak-to-average power is one of the main drawbacks in OFDM systems. This letter proposes a partial shift mapping (PSM) method for peak power reduction in OFDM systems. By utilizing the properties of the discrete Fourier transform, the proposed method generates a set of candidate signals without additional complex multiplication and selects the one with minimum peak power for transmission. Analyses and simulations confirm that the PSM method achieves satisfactory peak power reduction performance and low complexity compared with other kindred methods, for example, selected mapping and partial transmit sequences.

Study the influence of residual water during the preparation processes on the shear thickening behavior of silica/PEG200 suspensions

Ouyang Xing,Gong Lei,Huang Xiang,Chen Dazhu 한국유변학회 2024 Korea-Australia rheology journal Vol.36 No.3

Silica/PEG200 shear thickening fluids (STFs) are widely used smart fluids. There is often residual water during the STF preparation process because of the strong water adsorbability due to the abundant hydroxyl group on the silica surface. Residual water usually influences the shear-thickening behavior of STFs. How much influence the residual water has during the preparation processes on the properties of STFs is still a problem. In this paper, six preparation processes were designed, and the influence of residual water content on the shear thickening behavior due to different preparation processes is analyzed. Firstly, three drying processes were used to prepare STFs, i.e., three kinds of silica powder, which were obtained from spray, freeze, or oven drying of the silica dispersion, were dispersed in PEG200 to obtain STFs. Secondly, three wet processes were used to prepare STFs, i.e., three kinds of silica slurry, which were obtained by centrifuging and washing through water, ethanol, or tetrahydrofuran of the silica dispersion, were directly dispersed into PEG200 and dried to obtain STFs. All the silica dispersion used in these six preparation processes was prepared using the Stöber method. The properties, microstructure, and residual water content of the STFs prepared by the six preparation processes were explored. The results showed that the preparation processes have a big influence on the properties of related STFs. The silica’s residual water content derived from different preparation processes is the critical factor that affects STFs’ shear thickening performance. The drying process using silica powder from spray drying of the silica dispersion resulted in the lowest water content and led to the best shearthickening performance of the corresponding STFs. Meanwhile, the wet process using a slurry obtained by centrifuging and washing through tetrahydrofuran of the silica dispersion could also prepare STFs with good shear thickening behavior.

Conversion from CUL4-based COP1–SPA E3 apparatus to UVR8–COP1–SPA complexes underlies a distinct biochemical function of COP1 under UV-B

Huang, Xi,Ouyang, Xinhao,Yang, Panyu,Lau, On Sun,Chen, Liangbi,Wei, Ning,Deng, Xing Wang National Academy of Sciences 2013 PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF Vol.110 No.41

<P>The evolutionarily conserved CONSTITUTIVE PHOTOMORPHOGENESIS 1 (COP1) is a RING and WD40 protein that functions as a substrate receptor of CULLIN4–DAMAGED DNA BINDING PROTEIN 1 (CUL4–DDB1)–based E3 ubiquitin ligases in both plants and animals. In <I>Arabidopsis</I>, COP1 is a central repressor of photomorphogenesis in the form of COP1–SUPPRESSOR OF PHYA (SPA) complex(es). CUL4–DDB1–COP1–SPA suppresses the photomorphogenic program by targeting the transcription factor ELONGATED HYPOCOTYL 5 for degradation. Intriguingly, under photomorphogenic UV-B light, COP1 reverses its repressive role and promotes photomorphogenesis. However, the mechanism by which COP1 is functionally switched is still obscure. Here, we demonstrate that UV-B triggers the physical and functional disassociation of the COP1–SPA core complex(es) from CUL4–DDB1 and the formation of a unique complex(es) containing the UV-B receptor UV RESISTANCE LOCUS 8 (UVR8). The establishment of this UV-B–dependent COP1 complex(es) is associated with its positive modulation of ELONGATED HYPOCOTYL 5 stability and activity, which sheds light on the mechanism of COP1’s promotive action in UV-B–induced photomorphogenesis.</P>

Trapping tephritid fruit flies (Diptera: Tephritidae) in citrus groves of Fujian Province of China

Yulu Xia,Gecheng Ouyang,Xingli Ma,Bohua Hou,Jinghao Huang,Hanqing HU,Guocheng Fan 한국응용곤충학회 2020 Journal of Asia-Pacific Entomology Vol.23 No.4

Certain tephritid fruit flies, such as the oriental fruit fly, Bactrocera dorsalis, the Chinese citrus fly, B. minax and the Japanese orange fly, B. tsuneonis (Diptera: Tephritidae: Dacinae), are destructive citrus pests in China. A twoyear trapping study was conducted in pomelo, Citrus maxima, groves in Fujian Province of China. The objectives of this study were to investigate the species, the abundance of tephritid fruit flies in the orchards, as well as the efficacy of the selected lure traps to these flies. Four lure traps or devices, i.e. methyl eugenol + Steiner trap (ST), cuelure + ST, ammonium acetate + putrescine + ST, and sticky spheres, were deployed from June to November 2017 and April to October 2018. Six economically significant Dacini pests were trapped during the period. These flies are B. dorsalis, the melon fruit fly, Zeugodacus cucurbitae, the pumpkin fruit fly, Z. tau, the Malaysian fruit fly, B. latifrons, and other two species - B. rubigina and Z. scutellatus. B. dorsalis was the most abundant, accounting for more than 50% of the capture, followed by Z. cucurbitae. The remaining four species accounted for less than 2% of the total capture. B. minax and B. tsuneonis, two destructive citrus-damaging tephritid fruit flies in China, were not found during the trapping period. Methyl eugenol trapped the highest number of fruit flies, followed by cuelure.

NOx removal by non-thermal plasma at low temperatures with amino groups additives

Zhenzhen Guan,Jian-Xing Ren,Dezhen Chen,Liu Hong,Fangqin Li,Du Wang,Yuanhuang Ouyang,Yang Gao 한국화학공학회 2016 Korean Journal of Chemical Engineering Vol.33 No.11

NOx removal from flue gas using direct current (DC) narrow pulsed discharge-induced non-thermal plasma (NTP) was experimentally investigated. Factors such as additives, NOx initial concentrations, residence time, reaction temperatures inside the NTP reactor, and so on were investigated to evaluate their effects on NOx removal efficiencies. The focus was on the effects of additives containing amino groups. The results showed that H2O addition enhanced NOx removal, NH3 could further increase the NOx removal efficiencies under the same conditions without an obvious NH3 slip, and N2H4 was the most effective additive by reducing NOx to N2. X-Ray diffraction (XRD) analysis of the products collected from the NTP reactor demonstrated that NOx removal inside the NTP reactor was mainly based on NOx oxidation when ammonia or H2O was used as an additive, while NOx removal was mainly based on NOx reduction with the N2H4 additive.

Residual Load Sway Reduction Control in Double-pendulum Overhead Cranes Using Motion Trajectory Based on Adams-Matlab Joint Simulation

Jinxin Hu,Huimin Ouyang,Wenwei Huang,Ping Xing,Chunmin Yu,Guangming Zhang,Lei Mei,Xin Deng,Deming Wang 제어로봇시스템학회 2017 제어로봇시스템학회 국제학술대회 논문집 Vol.2017 No.10

When the hook mass is greater than the load mass or the load has a distributed mass property, the load sway of the crane system can be considered as a double-pendulum. At this point, the crane system has two kinds of natural angular frequency which greatly increases the difficulty of the dynamic analysis and the controller design. To this end, the linear dynamics of a 2-D overhead crane with double-pendulum effect is derived based on a disturbance observer and is decoupled for controller design by modal analysis. Second, an S-shaped curve, which is widely used in the control fields, is applied to the linearized decoupling crane model. The trajectory parameters are obtained by solving the algebraic equation. Finally, the validity of the method is verified by simulation results.