353 research outputs found

    The projective cover of tableau-cyclic indecomposable Hn(0)H_n(0)-modules

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    Let α\alpha be a composition of nn and σ\sigma a permutation in Sℓ(α)\mathfrak{S}_{\ell(\alpha)}. This paper concerns the projective covers of Hn(0)H_n(0)-modules Vα\mathcal{V}_\alpha, XαX_\alpha and Sασ\mathbf{S}^\sigma_{\alpha}, which categorify the dual immaculate quasisymmetric function, the extended Schur function, and the quasisymmetric Schur function when σ\sigma is the identity, respectively. First, we show that the projective cover of Vα\mathcal{V}_\alpha is the projective indecomposable module Pα\mathbf{P}_\alpha due to Norton, and XαX_\alpha and the ϕ\phi-twist of the canonical submodule Sβ,Cσ\mathbf{S}^{\sigma}_{\beta,C} of Sβσ\mathbf{S}^\sigma_{\beta} for (β,σ)(\beta,\sigma)'s satisfying suitable conditions appear as Hn(0)H_n(0)-homomorphic images of Vα\mathcal{V}_\alpha. Second, we introduce a combinatorial model for the ϕ\phi-twist of Sασ\mathbf{S}^\sigma_{\alpha} and derive a series of surjections starting from Pα\mathbf{P}_\alpha to the ϕ\phi-twist of Sα,Cid\mathbf{S}^{\mathrm{id}}_{\alpha,C}. Finally, we construct the projective cover of every indecomposable direct summand Sα,Eσ\mathbf{S}^\sigma_{\alpha, E} of Sασ\mathbf{S}^\sigma_{\alpha}. As a byproduct, we give a characterization of triples (σ,α,E)(\sigma, \alpha, E) such that the projective cover of Sα,Eσ\mathbf{S}^\sigma_{\alpha, E} is indecomposable.Comment: 41 page

    Homological properties of 0-Hecke modules for dual immaculate quasisymmetric functions

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    Let nn be a nonnegative integer. For each composition α\alpha of nn, Berg et al.\textit{et al.} introduced a cyclic indecomposable Hn(0)H_n(0)-module Vα\mathcal{V}_\alpha with a dual immaculate quasisymmetric function as the image of the quasisymmetric characteristic. In this paper, we study Vα\mathcal{V}_\alpha's from the homological viewpoint. To be precise, we construct a minimal projective presentation of Vα\mathcal{V}_\alpha and a minimal injective presentation of Vα\mathcal{V}_\alpha as well. Using them, we compute ExtHn(0)1(Vα,Fβ){\rm Ext}^1_{H_n(0)}(\mathcal{V}_\alpha, {\bf F}_\beta) and ExtHn(0)1(Fβ,Vα){\rm Ext}^1_{H_n(0)}( {\bf F}_\beta, \mathcal{V}_\alpha), where Fβ{\bf F}_\beta is the simple Hn(0)H_n(0)-module attached to a composition β\beta of nn. We also compute ExtHn(0)i(Vα,Vβ){\rm Ext}_{H_n(0)}^i(\mathcal{V}_\alpha,\mathcal{V}_{\beta}) when i=0,1i=0,1 and β≤lα\beta \le_l \alpha, where ≤l\le_l represents the lexicographic order on compositions.Comment: 44 pages, to be published in Forum of Math: Sigm

    DreamStyler: Paint by Style Inversion with Text-to-Image Diffusion Models

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    Recent progresses in large-scale text-to-image models have yielded remarkable accomplishments, finding various applications in art domain. However, expressing unique characteristics of an artwork (e.g. brushwork, colortone, or composition) with text prompts alone may encounter limitations due to the inherent constraints of verbal description. To this end, we introduce DreamStyler, a novel framework designed for artistic image synthesis, proficient in both text-to-image synthesis and style transfer. DreamStyler optimizes a multi-stage textual embedding with a context-aware text prompt, resulting in prominent image quality. In addition, with content and style guidance, DreamStyler exhibits flexibility to accommodate a range of style references. Experimental results demonstrate its superior performance across multiple scenarios, suggesting its promising potential in artistic product creation

    Qualitative Anatomical Characteristics of Compression, Lateral, and Opposite Woods in Pinus merkusii and Agathis loranthifolia

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    This study aimed to observe andcompare the qualitative anatomical characteristics of compression (CW), lateral (LW), and opposite (OW) woodsin the stem wood of Sumatran pine (Pinus merkusii) and Agathis (Agathis loranthifolia). The anatomical characteristics were observed using optical microscopy and scanning electron microscopy. CW showed a gradual transition from earlywood to latewood in both species, circular tracheid shape, many intercellular spaces, irregular tracheid tips, helical cavities, and slit-like bordered pits. CW of Sumatran pine showed an indistinct growth ring, whileCW of Agathis showed a distinct growth ring. Helical ribs occurred only in CW of Sumatran pine. LW and OW showed an oval tracheid with an angular outline, regular tracheid arrangement, and tapered tracheid tips in both species. LW and OW showed mainly uniseriate bordered pits in Sumatran pine, while LW and OW of Agathis frequently showed multiseriatebordered pits. CW, LW, and OW showed fusiform and uniseriate rays in Sumatran pine, while those of Agathis showed uniseriate rays. In conclusion, CW showed distinctive qualitative anatomical characteristics to LW and OW in both species, while LW and OW mainly showed similar characteristics. In particular, there were considerably distinctive characteristics between CW from both species.Keywords: Agathis, anatomical characteristics, reaction wood, Sumatran pin
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