344 research outputs found

    Generalized Ces\`{a}ro-like operator from a class of analytic function spaces to analytic Besov spaces

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    Let μ\mu be a finite positive Borel measure on [0,1)[0,1) and f(z)=n=0anznH(D)f(z)=\sum_{n=0}^{\infty}a_{n}z^{n} \in H(\mathbb{D}). For 0<α<0<\alpha<\infty, the generalized Ces\`aro-like operator Cμ,α\mathcal{C}_{\mu,\alpha} is defined by Cμ,α(f)(z)=n=0(μnk=0nΓ(nk+α)Γ(α)(nk)!ak)zn, zD, \mathcal {C}_{\mu,\alpha}(f)(z)=\sum^\infty_{n=0}\left(\mu_n\sum^n_{k=0}\frac{\Gamma(n-k+\alpha)}{\Gamma(\alpha)(n-k)!}a_k\right)z^n, \ z\in \mathbb{D}, where, for n0n\geq 0, μn\mu_n denotes the nn-th moment of the measure μ\mu, that is, μn=01tndμ(t)\mu_n=\int_{0}^{1} t^{n}d\mu(t). For s>1s>1, let XX be a Banach subspace of H(D) H(\mathbb{D}) with Λ1ssXB\Lambda^{s}_{\frac{1}{s}}\subset X\subset\mathcal {B}. In this paper, for 1p<1\leq p <\infty, we characterize the measure μ\mu for which Cμ,α\mathcal{C}_{\mu,\alpha} is bounded(or compact) from XX into analytic Besov space BpB_{p}

    Generalized integral type Hilbert operator acting on weighted Bloch space

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    Let μ\mu be a finite Borel measure on [0,1)[0,1). In this paper, we consider the generalized integral type Hilbert operator Iμα+1(f)(z)=01f(t)(1tz)α+1dμ(t)   (α>1).\mathcal{I}_{\mu_{\alpha+1}}(f)(z)=\int_{0}^{1}\frac{f(t)}{(1-tz)^{\alpha+1}}d\mu(t)\ \ \ (\alpha>-1). The operator Iμ1\mathcal{I}_{\mu_{1}} has been extensively studied recently. The aim of this paper is to study the boundedness(resp. compactness) of Iμα+1\mathcal{I}_{\mu_{\alpha+1}} acting from the normal weight Bloch space into another of the same kind. As consequences of our study, we get completely results for the boundedness of Iμα+1 \mathcal{I}_{\mu_{\alpha+1}} acting between Bloch type spaces, logarithmic Bloch spaces among others.Comment: arXiv admin note: text overlap with arXiv:2208.1074

    HDIdx: High-Dimensional Indexing for Efficient Approximate Nearest Neighbor Search

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    Fast Nearest Neighbor (NN) search is a fundamental challenge in large-scale data processing and analytics, particularly for analyzing multimedia contents which are often of high dimensionality. Instead of using exact NN search, extensive research efforts have been focusing on approximate NN search algorithms. In this work, we present "HDIdx", an efficient high-dimensional indexing library for fast approximate NN search, which is open-source and written in Python. It offers a family of state-of-the-art algorithms that convert input high-dimensional vectors into compact binary codes, making them very efficient and scalable for NN search with very low space complexity

    Beamforming Based on Finite-Rate Feedback

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    Blockholder Mutual Fund Participation in Private In-House Meetings

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    The Shenzhen Stock Exchange (SZSE) in China is unique worldwide in requiring disclosure of the timing, participants, and selected content of private in-house meetings between firm managers and outsider investors. We investigate whether these private meetings benefit hosting firms and their major outside institutional investors—blockholder mutual funds (i.e., funds with ownership ≥5%). Using a large data set of SZSE firms, we find that blockholder mutual funds have more access to private in-house meetings, and top management is more likely to be present, especially when a meeting is associated with negative news. Furthermore, when blockholder mutual funds attend negative-news meetings with top management, they are less likely to sell shares, their investment relationship with the hosting firm lasts longer, and hosting firms experience lower postmeeting stock return volatility. These findings suggest that private in-house meetings are an informative disclosure channel that improves social bonding between top management and blockholder mutual funds in ways that benefit hosting firms

    Traffic Volume Forecasting Model of Freeway Toll Stations During Holidays – An SVM Model

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    Support vector machine (SVM) models have good performance in predicting daily traffic volume at toll stations, however, they cannot accurately predict holiday traffic volume. Therefore, an improved SVM model is proposed in this paper. The paper takes a toll station in Heilongjiang, China as an example, and uses the daily traffic volume as the learning set. The current and previous 7-day traffic volumes are used as the dependent and independent variables for model learning, respectively. This paper found that the basic SVM model is not accurate enough to forecast the traffic volume during holidays. To improve the model accuracy, this paper first used the SVM model to forecast non-holiday traffic volumes, and proposed a prediction method using quarterly conversion coefficients combined with the SVM model to construct an improved SVM model. The result of the prediction showed that the improved SVM model in this paper was able to effectively improve accuracy, making it better than in the basic SVM and GBDT model, thus proving the feasibility of the improved SVM model

    Several Integral Estimates and Some Applications

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    In this paper, the authors first consider the bidirectional estimates of several typical integrals. As some applications of these integral estimates, the authors investigate the pointwise multipliers from the normal weight general function space F(p,μ,s)F(p,\mu,s) to the normal weight Bloch type space Bν(Bn)\mathcal{B_{\nu}}(B_{n}) on the unit ball BnB_{n} of Cn\mathbb{C}^{n}, where μ\mu and ν\nu are two normal functions on [0,1)[0,1). For the special normal function μ(r)=(1r2)αlogβe1r2\displaystyle{\mu(r)=(1-r^{2})^{\alpha}\log^{\beta}\frac{e}{1-r^{2}}} (α>0\alpha>0, <β<-\infty<\beta<\infty), the authors give the necessary and sufficient conditions of pointwise multipliers from F(p,μ,s)F(p,\mu,s) to Bν(Bn)\mathcal{B_{\nu}}(B_{n}) for all cases
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