12,324 research outputs found

    Dispelling the Anthropic Principle from the Dimensionality Arguments

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    It is shown that in d=11 supergravity, under a very reasonable ansatz, the nearly flat spacetime in which we are living must be 4-dimensional without appealing to the Anthropic Principle. Can we dispel the Anthropic Principle completely from cosmology?Comment: 7 pages, Essa

    Condensate wave function and elementary excitations of bosonic polar molecules: beyond the first Born approximation

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    We investigate the condensate wave function and elementary excitations of strongly interacting bosonic polar molecules in a harmonic trap, treating the scattering amplitude beyond the standard first Born approximation (FBA). By using an appropriate trial wave function in the variational method, effects of the leading order correction beyond the FBA have been investigated and shown to be significantly enhanced when the system is close to the phase boundary of collapse. How such leading order effect of going beyond the FBA can be observed in a realistic experiment is also discussed.Comment: 7 pages, 4 figure

    Identifying and Measuring the Effect of Firm Clusters Among Certified Organic Processors and Handlers

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    This paper investigates the certified organic handler sector, a specialized component of the middle part of the farm-to-table marketing chain, and documents the impacts of firm agglomeration (or firm clusters) on firm-level performance or firm-level decisions. After accounting for endogeneity in firm clustering, our findings confirm that firm clusters have significant impacts, though the estimate of the impact depends on how a firm cluster is defined. For example, significant impacts on sales per employee range from an additional 0.17millionto0.17 million to 1.47 million, depending on whether a small or large number of firms is used as the minimum number to define a firm cluster.firm clusters, organic, treatment effects, Agribusiness, Agricultural and Food Policy, Community/Rural/Urban Development,

    The Photonic Band theory and the negative refraction experiment of metallic helix metamaterials

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    We develop a theory to compute and interpret the photonic band structure of a periodic array of metallic helices for the first time. Interesting features of band structure include the ingenuous longitudinal and circularly polarized eigenmodes, the wide polarization gap [Science 325, 1513 (2009)], and the helical symmetry guarantees the existence of negative group velocity bands at both sides of the polarization gap and band crossings pinned at the zone boundary with fixed frequencies. A direct proof of negative refraction via a chiral route [Science 306, 1353 (2004)] is achieved for the first time by measuring Gooshanchen shift through a slab of three dimensional bona fide helix metamaterial

    The BXsl+lB\to X_sl^+l^- and BXsγB\to X_s \gamma decays with the fourth generation

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    If the fourth generation fermions exist, the new quarks could influence the branching ratios of the decays of BXsγB\to X_s \gamma and BXsl+lB\to X_sl^+l^-. We obtain two solutions of the fourth generation CKM factor VtsVtbV^{*}_{t^{'}s}V_{t^{'}b} from the decay of BXsγB\to X_s \gamma. We use these two solutions to calculate the new contributions of the fourth generation quark to Wilson coefficients of the decay of BXsl+lB\to X_sl^+l^-. The branching ratio and the forward-backward asymmetry of the decay of BXsl+lB\to X_sl^+l^- in the two cases are calculated. Our results are quite different from that of SM in one case, almost same in another case. If Nature chooses the formmer, the BB meson decays could provide a possible test of the forth generation existence.Comment: 10 pages, 5 figure

    Integrating Emotion Recognition with Speech Recognition and Speaker Diarisation for Conversations

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    Although automatic emotion recognition (AER) has recently drawn significant research interest, most current AER studies use manually segmented utterances, which are usually unavailable for dialogue systems. This paper proposes integrating AER with automatic speech recognition (ASR) and speaker diarisation (SD) in a jointly-trained system. Distinct output layers are built for four sub-tasks including AER, ASR, voice activity detection and speaker classification based on a shared encoder. Taking the audio of a conversation as input, the integrated system finds all speech segments and transcribes the corresponding emotion classes, word sequences, and speaker identities. Two metrics are proposed to evaluate AER performance with automatic segmentation based on time-weighted emotion and speaker classification errors. Results on the IEMOCAP dataset show that the proposed system consistently outperforms two baselines with separately trained single-task systems on AER, ASR and SD.Comment: Interspeech 202

    Distribution-based Emotion Recognition in Conversation

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    Automatic emotion recognition in conversation (ERC) is crucial for emotion-aware conversational artificial intelligence. This paper proposes a distribution-based framework that formulates ERC as a sequence-to-sequence problem for emotion distribution estimation. The inherent ambiguity of emotions and the subjectivity of human perception lead to disagreements in emotion labels, which is handled naturally in our framework from the perspective of uncertainty estimation in emotion distributions. A Bayesian training loss is introduced to improve the uncertainty estimation by conditioning each emotional state on an utterance-specific Dirichlet prior distribution. Experimental results on the IEMOCAP dataset show that ERC outperformed the single-utterance-based system, and the proposed distribution-based ERC methods have not only better classification accuracy, but also show improved uncertainty estimation.Comment: To appear in SLT 202

    A resonant feature near the Perseus arm revealed by red clump stars

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    We investigate the extinction together with the radial velocity dispersion and distribution of red clump stars in the anti-center direction using spectra obtained with Hectospec on the MMT. We find that extinction peaks at Galactocentric radii of about 9.5 and 12.5 kpc, right in front of the locations of the Perseus and Outer arms and in line with the relative position of dust and stars in external spiral galaxies. The radial velocity dispersion peaks around 10kpc, which coincides with the location of the Perseus arm, yields an estimated arm-interarm density contrast of 1.3-1.5 and is in agreement with previous studies. Finally, we discover that the radial velocity distribution bifurcates around 10-11 kpc into two peaks at +27 km/s and -4 km/s. This seems to be naturally explained by the presence of the outer Lindblad resonance of the Galactic bar, but further observations will be needed to understand if the corotation resonance of the spirals arms also plays a role.Comment: 8 pages, 2 figures, accepted for publication in ApJ
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