The electromagnetic form factors of the proton in the timelike region

The reactions ppbar -> e+e- and e+e- -> ppbar are analyzed in the near-threshold region. Specific emphasis is put on the role played by the interaction in the initial- or final antinucleon-nucleon state which is taken into account rigorously. For that purpose a recently published NNbar potential derived within chiral effective field theory and fitted to results of a new partial-wave analysis of ppbar scattering data is employed. Our results provide strong support for the conjecture that the pronounced energy dependence of the e+e- ppbar cross section, seen in pertinent experiments, is primarily due to the ppbar interaction. Predictions for the proton electromagnetic form factors G_E and G_M in the timelike region, close to the NNbar threshold, and for spin-dependent observables are presented. The steep rise of the effective form factor for energies close to the ppbar threshold is explained solely in terms of the ppbar interaction. The corresponding experimental information is quantitatively described by our calculation.Comment: 14 pages, 11 figure

Massive and Red Objects predicted by a semianalytical model of galaxy formation

We study whether hierarchical galaxy formation in a concordance $\Lambda$CDM universe can produce enough massive and red galaxies compared to the observations. We implement a semi-analytical model in which the central black holes gain their mass during major mergers of galaxies and the energy feedback from active galaxy nuclei (AGN) suppresses the gas cooling in their host halos. The energy feedback from AGN acts effectively only in massive galaxies when supermassive black holes have been formed in the central bulges. Compared with previous models without black hole formation, our model predicts more massive and luminous galaxies at high redshift, agreeing with the observations of K20 up to $z\sim 3$. Also the predicted stellar mass density from massive galaxies agrees with the observations of GDDS. Because of the energy feedback from AGN, the formation of new stars is stopped in massive galaxies with the termination of gas cooling and these galaxies soon become red with color $R-K>$5 (Vega magnitude), comparable to the Extremely Red Objects (EROs) observed at redshift $z\sim$1-2. Still the predicted number density of very EROs is lower than observed at $z\sim 2$, and it may be related to inadequate descriptions of dust extinction, star formation history and AGN feedback in those luminous galaxies.Comment: Accepted for Publication in ApJ, added reference

Effect of dynamic visual form on sound preference of waterscape

Waterscape has a positive impact on the preference of public space. This study investigated three fountains in Harbin, China, to explore whether their dynamic visual form and corresponding sound rhythm change would affect the sound preference evaluation of the waterscapes. In total, 150 visitors were selected to answer a questionnaire on site, on how they perceived the fountain, including its visual and acoustic environment. It was found from the field experiment that people had different preferences for the sound of waterscape. The waterscape was then classified and subjectively evaluated in laboratory from visual and auditory aspects. The results show that, the evaluation of the rhythm of several kinds of water had little difference when there was no visual stimuli, but participants preferred dynamic visual form to steady-state continuous form, in which the significant rhythm change was more acceptant. The higher the score of visual form was, the better the evaluation of waterscape was. In general, in this study a significant positive correlation was observed between the dynamic visual form of fountain and the preference of waterscape

Provenance analysis for instagram photos

As a feasible device fingerprint, sensor pattern noise (SPN) has been proven to be effective in the provenance analysis of digital images. However, with the rise of social media, millions of images are being uploaded to and shared through social media sites every day. An image downloaded from social networks may have gone through a series of unknown image manipulations. Consequently, the trustworthiness of SPN has been challenged in the provenance analysis of the images downloaded from social media platforms. In this paper, we intend to investigate the effects of the pre-defined Instagram images filters on the SPN-based image provenance analysis. We identify two groups of filters that affect the SPN in quite different ways, with Group I consisting of the filters that severely attenuate the SPN and Group II consisting of the filters that well preserve the SPN in the images. We further propose a CNN-based classifier to perform filter-oriented image categorization, aiming to exclude the images manipulated by the filters in Group I and thus improve the reliability of the SPN-based provenance analysis. The results on about 20, 000 images and 18 filters are very promising, with an accuracy higher than 96% in differentiating the filters in Group I and Group II

Effect of visual landscape factors on soundscape evaluation in old residential areas

The visual landscape influences the soundscape experience of urban public spaces. The purpose of this study is to analyze the relationships among visual landscape factors and soundscape evaluation of old residential areas and determine their main influencing factors. In Tianjin, China, six typical old residential areas were selected to collect sound and video information. Virtual reality (VR) was used to create an evaluation environment, and subjective evaluations of the visual landscape and soundscape were accessed through questionnaire (N = 256). The results show that the evaluation of soundscape and visual landscape satisfaction of the central square in the old residential area is superior to that of the public space along the street, as affected by spatial location, sound characteristics and other factors. Greenery satisfaction, environmental cleanliness, and architectural aesthetics were significantly positively correlated with soundscape evaluation. Additionally, three latent variables, namely, visual landscape factors, spatial factors and soundscape evaluation factors, were identified through factor analysis, and a structural equation model (SEM) of “visual landscape factors–soundscape evaluation” was built. The visual landscape factors in old residential areas were found to be important factors affecting soundscape evaluation. The standardization coefficient was 0.46 (P ≤ 0.01). Although the spatial factors have no direct contribution to the soundscape evaluation of the old residential areas, its observation variable, environmental cleanliness, is significantly positively correlated with all the observed variables of the soundscape evaluation factors

Coordinated workload scheduling in hierarchical sensor networks for data fusion applications

2007-2008 > Academic research: refereed > Refereed conference paperVersion of RecordPublishe

Extracting CP violation and strong phase in D decays by using quantum correlations in psi(3770)-> D0\bar{D}0 -> (V1V2)(V3V4) and psi(3770)->D0\bar{D}0 -> (V1V2)(K pi)

The charm quark offers interesting opportunities to cross-check the mechanism of CP violation precisely tested in the strange and beauty sectors. In this paper, we exploit the angular and quantum correlations in the D\bar{D} pairs produced through the decay of the psi(3770) resonance in a charm factory to investigate CP-violation in two different ways. We build CP-violating observables in psi(3770) -> D\bar{D} -> (V_1V_2)(V_3 V_4) to isolate specific New Physics effects in the charm sector. We also consider the case of psi(3770) -> D\bar{D} -> (V_1V_2)(K\pi) decays, which provide a new way to measure the strong phase difference delta between Cabibbo-favored and doubly-Cabibbo suppressed D decays required in the determination of the CKM angle gamma. Neglecting the systematics, we give a first rough estimate of the sensitivities of these measurements at BES-III with an integrated luminosity of 20 fb^-1 at psi(3770) peak and at a future Super tau-charm factory with a luminosity of 10^35 cm^-2.s^-1.Comment: 13 pages

Red Soundscape Index (RSI): An index with the potential to assess soundscape quality

It is not enough to define urban soundscape just using the green soundscape index (GSI), which is the ratio of the perception of natural sounds to the perception of traffic noises. Therefore, in the present study, red soundscape index (RSI), defined as the ratio of perception of natural sounds to perception of human sounds, was introduced. The data for calculating RSI were collected from sound environment measurements and a questionnaire-based survey in seven urban parks in Harbin city, China. The results revealed the following: (1) RSI was correlated with the overall soundscape quality; (2) RSI was correlated with the maximum and minimum instantaneous sound pressure levels and with equivalent sound pressure levels; and (3) The urban sound environment as well as sound quality can be classified by RSI. It was confirmed that RSI could be used as a supplement to GSI in urban soundscape planning

Effect of the Visual Landscape and Soundscape Factors on Attention Restoration in the Public Space of Old Residential Areas by VR

The purpose of this study is to analyze the relationship between the visual landscape and soundscape factors of the public spaces in old residential areas and their attention restoration benefits for residents and to determine the main influencing factors. In this paper, the public spaces of six typical old residential areas in Tianjin were selected as the research object, and the restorative benefits of the respondents were analyzed through virtual reality environment, subjective evaluation, and attention testing methods. The results showed that the attention restoration benefits of the central square in the old residential area were better than those of the public space along the street. Second, greenery satisfaction, environmental cleanliness, architectural aesthetics, sky visibility, and soundscape evaluation are all significantly positively correlated with the attention restoration level. Finally, a “visual landscape and soundscape perception evaluation-attention restoration level” structural equation model was constructed. According to the model, both the visual landscape factors and soundscape evaluation factors in old residential areas had a direct positive impact on the attention restoration level, with a greater impact exerted by visual landscape factors than by soundscape evaluation factors. The findings from this study can provide significant information for the renewal of old residential areas

A self-selective correlation ship tracking method for smart ocean systems

In recent years, with the development of the marine industry, the ship navigation environment has become more complicated. Some artificial intelligence technologies, such as computer vision, can recognize, track and count sailing ships to ensure maritime security and facilitate management for Smart Ocean systems. Aiming at the scaling problem and boundary effect problem of traditional correlation filtering methods, we propose a self-selective correlation filtering method based on box regression (BRCF). The proposed method mainly includes: (1) A self-selective model with a negative samples mining method which effectively reduces the boundary effect in strengthening the classification ability of the classifier at the same time; (2) a bounding box regression method combined with a key points matching method for the scale prediction, leading to a fast and efficient calculation. The experimental results show that the proposed method can effectively deal with the problem of ship size changes and background interference. The success rates and precisions were over 8 % higher than Discriminative Scale Space Tracking (DSST) on the marine traffic dataset of our laboratory. In terms of processing speed, the proposed method is higher than DSST by nearly 22 frames per second (FPS).This research was supported by the National Natural Science Foundation of China under Grant (No. 61772387 and No. 61802296), the Fundamental Research Funds of Ministry of Education and China Mobile (MCM20170202), the Fundamental Research Funds for the Central Universities (JB180101), China Postdoctoral Science Foundation Grant (No. 2017M620438), and supported by ISN State Key Laboratory