8,982 research outputs found
Performance Evaluation of Distributed-Antenna Communications Systems Using Beam-Hopping
No full textDigital beamforming (DBF) techniques are capable of improving the performance of communications systems significantly. However, if the transmitted signals are conflicted with strong interference, especially, in the direction of the transmitted beams , these directional jamming signals will severely degrade the system performance. In order to efficiently mitigate the interference of the directional jammers, in this contribution a beam-hopping (BH) communications scheme is proposed. In the proposed BH communications scheme, only one pair of the beams is used for transmission and it hops from one to the next according to an assigned BH pattern. In this contribution a range of expressions in terms of the average SINR performance have been derived, when both the uplink and downlink are considered. The average SINR performance of the proposed BH scheme and that of the conventional single-beam (SB) as well as multiple-beam (MB) assisted beam-processing schemes have been investigated. Our analysis and results show that the proposed BH scheme is capable of efficiently combating the directional jamming, with the aid of utilizing the directional gain of the beams generated by both the transmitter and the receiver. Furthermore, the BH scheme is capable of reducing the intercept probability of the communications. Therefore, the proposed BH scheme is suitable for communications, when several distributed antenna arrays are available around a mobile
Tun hu: (du mu ju ji).
No full text復工之前 -- 母女們 -- 囤戶.吳天著.Drama.Wu Tian zhu.Fu gong zhi qian -- Mu nü men -- Tun hu
Flow dynamics on a U shaped channel flow: a numerical study
No full textThe paper deals with the numerical simulation of river channel flows at laboratory scale. The adopted geometry
consists of a U shaped trapezoidal smooth open channel with fixed slope. The branches, 3m of length each, are linked with a joint, 0.40m long, realizing two 90 degrees bends. The system is fed upstream with a water discharge under critical conditions while a Cipolletti weir is set downstream to control flow profiles.
Steady flow movements are obtained by means of two different softwares: a pure Lagrangian developed by the author, based on the Weakly Compressible Smoothed Particle Hydrodynamics (WCSPH) technique and Flow3D®, a commercial CFD software based on a Finite Volume formulation of the Navier Stokes equations in the Eulerian framework. Depending on the assumed boundary conditions, velocity profiles and water interfaces at certain cross sections are deducted by using the codes. Results are discussed and compared, showing a satisfactory agreement
HU Protein Induces Incoherent DNA Persistence Length
No full textHU is a highly conserved protein that is believed to play an important role in the architecture and dynamic compaction of bacterial DNA. Its ability to control DNA bending is crucial for functions such as transcription and replication. The effects of HU on the DNA structure have been studied so far mainly by single molecule methods that require us to apply stretching forces on the DNA and therefore may perturb the DNA-protein interaction. To overcome this hurdle, we study the effect of HU on the DNA structure without applying external forces by using an improved tethered particle motion method. By combining the results with DNA curvature analysis from atomic force microscopy measurements we find that the DNA consists of two different curvature distributions and the measured persistence length is determined by their interplay. As a result, the effective persistence length adopts a bimodal property that depends primarily on the HU concentration. The results can be explained according to a recently suggested model that distinguishes single protein binding from cooperative protein binding.Imaging Science and TechnologyApplied Science
Systematics of a Kleptoplastidal Dinoflagellate, Gymnodinium eucyaneum Hu (Dinophyceae), and Its Cryptomonad Endosymbiont
No full textNew specimens of the kleptoplastidal dinoflagellate Gymnodinium eucyaneum Hu were collected in China. We investigated the systematics of the dinoflagellate and the origin of its endosymbiont based on light morphology and phylogenetic analyses using multiple DNA sequences. Cells were dorsoventrally flattened with a sharply acute hypocone and a hemispherical epicone. The confusion between G. eucyaneum and G. acidotum Nygaard still needs to be resolved. We found that the hypocone was conspicuously larger than the epicone in most G. eucyaneum cells, which differed from G. acidotum, but there were a few cells whose hypocone and epicone were of nearly the same size. In addition, there was only one site difference in the partial nuclear LSU rDNA sequences of a sample from Japan given the name G. acidotum and G. eucyaneum in the present study, which suggest that G. eucyaneum may be a synonym of G. acidotum. Spectroscopic analyses and phylogenetic analyses based on nucleomorph SSU rDNA sequences and chloroplast 23 s rDNA sequences suggested that the endosymbiont of G. eucyaneum was derived from Chroomonas (Cryptophyta), and that it was most closely related to C. coerulea Skuja. Moreover, the newly reported kleptoplastidal dinoflagellates G. myriopyrenoides and G. eucyaneum in our study were very similar, and the taxonomy of kleptoplastidal dinoflagellates was discussed.New specimens of the kleptoplastidal dinoflagellate Gymnodinium eucyaneum Hu were collected in China. We investigated the systematics of the dinoflagellate and the origin of its endosymbiont based on light morphology and phylogenetic analyses using multiple DNA sequences. Cells were dorsoventrally flattened with a sharply acute hypocone and a hemispherical epicone. The confusion between G. eucyaneum and G. acidotum Nygaard still needs to be resolved. We found that the hypocone was conspicuously larger than the epicone in most G. eucyaneum cells, which differed from G. acidotum, but there were a few cells whose hypocone and epicone were of nearly the same size. In addition, there was only one site difference in the partial nuclear LSU rDNA sequences of a sample from Japan given the name G. acidotum and G. eucyaneum in the present study, which suggest that G. eucyaneum may be a synonym of G. acidotum. Spectroscopic analyses and phylogenetic analyses based on nucleomorph SSU rDNA sequences and chloroplast 23 s rDNA sequences suggested that the endosymbiont of G. eucyaneum was derived from Chroomonas (Cryptophyta), and that it was most closely related to C. coerulea Skuja. Moreover, the newly reported kleptoplastidal dinoflagellates G. myriopyrenoides and G. eucyaneum in our study were very similar, and the taxonomy of kleptoplastidal dinoflagellates was discussed
[[alternative]]The study of the ocean sport’s attraction, service quality and behavioral consequences in Peng-hu
No full text[[abstract]]The main purpose of this study were to explore the relations between the ocean sport’s attraction, service quality and behavioral consequences in Peng-hu. The researcher applied the questionnaire of “the ocean sport’s attraction, service quality and behavioral consequences in Peng-hu “ and I drew 500 visitors as the research samples who participated in ocean sports in Peng-hu during August and September in 2005. The data collected from valid questionnaires were analyzed by descriptive statistics, Pearson’s product moment correlation, stepwise multiple regression analysis and canonical correlation analysis. The results are as followed:
1. The ocean sports in Peng-hu attracted visitors to a certain degree and the whole service quality is comfortable to them.
2. The relationship between the ocean sport’s attraction and service quality in Peng-hu was positive to a certain degree, and the higher service quality is, the greater ocean sport’s attraction in Peng-hu is.
3. Within each factors of the ocean sport’s attraction and the service quality, “the specialty of designing activity “and “the comfort of the environment “ had the best prediction to the loyalty of behavioral consequences; “advertisement and spread of the main activity” and “personal requirement” explain “better than any other factors.
4. The canonical correlation analysis of the study was the ocean sport’s attraction and service quality in Peng-hu have a high and positive correlation with the loyalty of behavioral consequences; the ocean sport’s attraction in Peng-hu has a moderate and positive correlation with the tendency of complaint of behavioral consequences.
Based on the results, we suggest the related organizations should:（1）strengthen the diversity of activity and develop package route of travel;（2）enforce the communication of information and promote the quality of complementary service;（3）integrate the resources and set up conservation area to build the continuous managing mold of ocean sport’s tourism.
For further research in the future: incorporate the follow-up issue of ocean sport’s tourism with profound interview and pay equal attention to qualitative research and quantitative research. Extending the subjects to related organization administrators、managers and dealers、local people and foreign tourist etc. and proceeding a comprehensive research.
Transition to turbulence in a qblique shock-wave/boundary-layer interaction at M=15
No full textDirect numerical simulations are carried out for different forcing techniques to trigger transition during the interaction between an oblique shock-wave and a laminar boundary-layer at M = 1.5. Three forcing methods are used: a) forcing of oblique unstable modes, whose shape and behaviour are determined by the local linear stability theory, b) broadband free-stream acoustic disturbances, and c) a cold plasma flow control device. While the oblique-mode breakdown is dominant for low-amplitude forcing, long streaky structures drive the transition process in a high-amplitude disturbance environment. LES are also performed on the experimental setup by the Institute of Theoretical and Applied Mechanics (ITAM) from Novosibirsk State University with cold plasma actuation. As well as the disturbance type, the effect of Reynolds number and forcing amplitude will be investigated
A specific single-stranded DNA induces a distinct conformational change in the nucleoid-associated protein HU
No full textAbstractIn prokaryotic cells, genomic DNA forms an aggregated structure with various nucleoid-associated proteins (NAPs). The functions of genomic DNA are cooperatively modulated by NAPs, of which HU is considered to be one of the most important. HU binds double-stranded DNA (dsDNA) and serves as a structural modulator in the genome architecture. It plays important roles in diverse DNA functions, including replication, segregation, transcription and repair. Interestingly, it has been reported that HU also binds single-stranded DNA (ssDNA) regardless of sequence. However, structural analysis of HU with ssDNA has been lacking, and the functional relevance of this binding remains elusive.In this study, we found that ssDNA induced a significant change in the secondary structure of Thermus thermophilus HU (TtHU), as observed by analysis of circular dichroism spectra. Notably, this change in secondary structure was sequence specific, because the complementary ssDNA or dsDNA did not induce the change. Structural analysis using nuclear magnetic resonance confirmed that TtHU and this ssDNA formed a unique structure, which was different from the previously reported structure of HU in complex with dsDNA. Our data suggest that TtHU undergoes a distinct structural change when it associates with ssDNA of a specific sequence and subsequently exerts a yet-to-be-defined function
First person – Jinhang Hu
No full textABSTRACT
First Person is a series of interviews with the first authors of a selection of papers published in Journal of Cell Science, helping early-career researchers promote themselves alongside their papers. Jinhang Hu is the first author on ‘CCR2 3′UTR functions as a competing endogenous RNA to inhibit breast cancer metastasis’, published in Journal of Cell Science. Jinhang conducted the work in this article in Tao Xi's lab at China Pharmaceutical University, Nanjing, China. She is now a research associate with Zhishu Tang at the Shaanxi University of Chinese Medicine in Xian Yang, China, investigating the bioactive constituents and anti-tumour mechanisms of the active ingredients in traditional Chinese medicine.</jats:p
The Inception and Expansion of the Hu Che Cult
No full textThis paper examines the inception and expansion of the Hu Che cult from the medieval period to the present in Che-Chiang 浙江 Province. Hu Che 胡則 (963-1039) was a well-known official of the Northern Song Dynasty. However, concerning the contributions he made during his career, nothing is related to Che-Chiang Province. So how did Hu become a distinguished deity in Che-Chiang Province? Concerning this problem, the author makes the following points.After Hu Che’s death, a tale was circulated in Wu-chou 婺州 Prefecture, where Hu was born, and neighboring Ch’ü-chou 衢州 Prefecture, which said that the adult male poll tax (身丁銭) had been exempted in the two prefectures because of a petition Hu submitted to the emperor. This satisfied the people’s desire for tax abatement in these areas. This is how the Hu Che cult originated and spread there. In areas that not mentioned in the tax abatement tale, various other kinds of tales about Hu’s achievements during his lifetime or miracles that occurred after his death circulated. These tales either catered to the various desires of the people or created images conforming to the doctrines of Confucian, leading to the spread of the Hu Che cult throughout Che-Chiang Province.Buddhist monks played important roles in the origin and expansion of the Hu Che cult. They were not only involved in the building of Hu Che’s temple, but also took part in the invention of tales about him, helping Hu Che to became one of the most popular deities in Che-Chiang Province. On the other hand, Hu Che became an official through success in the Civil Examination, and was active in the North Song government for many years, leading to worship and support also from the literati in local society. They not only beatified Hu Che’s personality, but also petitioned the central government for Hu Che’s titles and awards. The belief in Hu Che could never have lasted without such activities on the part of the local literati｡Through this study of the Hu Che cult, three conclusions can be drawn. First, to have a person deified, it was necessary to create tales about his career. Secondly, Buddhist monks were also deeply involved in the origin and expansion of local or regional beliefs, and in some cases played a pivotal role. Finally, through the participation of the literati, government spokesmen for local beliefs may appear. It was under such a situation, that the central government could tolerate or even support local beliefs and deities.journal articl
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