LFS-GAN: Lifelong Few-Shot Image Generation

We address a challenging lifelong few-shot image generation task for the first time. In this situation, a generative model learns a sequence of tasks using only a few samples per task. Consequently, the learned model encounters both catastrophic forgetting and overfitting problems at a time. Existing studies on lifelong GANs have proposed modulation-based methods to prevent catastrophic forgetting. However, they require considerable additional parameters and cannot generate high-fidelity and diverse images from limited data. On the other hand, the existing few-shot GANs suffer from severe catastrophic forgetting when learning multiple tasks. To alleviate these issues, we propose a framework called Lifelong Few-Shot GAN (LFS-GAN) that can generate high-quality and diverse images in lifelong few-shot image generation task. Our proposed framework learns each task using an efficient task-specific modulator - Learnable Factorized Tensor (LeFT). LeFT is rank-constrained and has a rich representation ability due to its unique reconstruction technique. Furthermore, we propose a novel mode seeking loss to improve the diversity of our model in low-data circumstances. Extensive experiments demonstrate that the proposed LFS-GAN can generate high-fidelity and diverse images without any forgetting and mode collapse in various domains, achieving state-of-the-art in lifelong few-shot image generation task. Surprisingly, we find that our LFS-GAN even outperforms the existing few-shot GANs in the few-shot image generation task. The code is available at Github.Comment: 20 pages, 19 figures, 14 tables, ICCV 2023 Poste

Systematic comparison between the generalized Lorenz equations and DNS in the two-dimensional Rayleigh–Bénard convection

The classic Lorenz equations were originally derived from the two-dimensional Rayleigh–Bénard convection system considering an idealized case with the lowest order of harmonics. Although the low-order Lorenz equations have traditionally served as a minimal model for chaotic and intermittent atmospheric motions, even the dynamics of the two-dimensional Rayleigh–Bénard convection system is not fully represented by the Lorenz equations, and such differences have yet to be clearly identified in a systematic manner. In this paper, the convection problem is revisited through an investigation of various dynamical behaviors exhibited by a two-dimensional direct numerical simulation (DNS) and the generalized expansion of the Lorenz equations (GELE) derived by considering additional higher-order harmonics in the spectral expansions of periodic solutions. Notably, GELE allows us to understand how nonlinear interactions among high-order modes alter the dynamical features of the Lorenz equations including fixed points, chaotic attractors, and periodic solutions. It is verified that numerical solutions of the DNS can be recovered from the solutions of GELE when we consider the system with sufficiently high-order harmonics. At the lowest order, the classic Lorenz equations are recovered from GELE. Unlike in the Lorenz equations, we observe limit tori, which are the multi-dimensional analog of limit cycles, in the solutions of the DNS and GELE at high orders. Initial condition dependency in the DNS and Lorenz equations is also discussed. The Lorenz equations are a simplified nonlinear dynamical system derived from the two-dimensional Rayleigh–Bénard (RB) convection problem. They have been one of the best-known examples in chaos theory due to the peculiar bifurcation and chaos behaviors. They are often regarded as the minimal chaotic model for describing the convection system and, by extension, weather. Such an interpretation is sometimes challenged due to the simplifying restriction of considering only a few harmonics in the derivation. This study loosens this restriction by considering additional high-order harmonics and derives a system we call the generalized expansion of the Lorenz equations (GELE). GELE allows us to study how solutions transition from the classic Lorenz equations to high-order systems comparable to a two-dimensional direct numerical simulation (DNS). This study also proposes mathematical formulations for a direct comparison between the Lorenz equations, GELE, and two-dimensional DNS as the system’s order increases. This work advances our understanding of the convection system by bridging the gap between the classic model of Lorenz and a more realistic convection syste

Concert recording 2019-03-29

[Track 1]. Ionhontsiá:te (Mother earth). Grandmother moon for soprano and cello / Dawn Ierihò:kwats Avery -- [Track 2]. Lieux ecartez, paisible solitude from Céphale et Procris / Élisabeth Jacquet de La Guerre -- [Track 3]. Four Dickinson songs / Lori Laitman Emily Dickinson -- [Track 4]. Guendae Issume (Because you are here) / Sunae Kim -- [Track 5]. Lee Eung and Arirang (Arirang) / YoungRan Park -- [Track 6]. She tell her love [Track 7]. A boy and a girl / Stephen Caldwell -- [Track 8]. Morgen, op. 27, no. 4 [Track 9]. Heimliche Aufforderung, op. 27, no. 3 / Richard Strauss -- [Track 10]. Suleika, op. 14, no. 1 / Franz Schubert -- [Track 11]. Philine: Singet nicht in Trauertönen, op. 98a, no. 7 / Robert Schumann -- [Track 12]. Mignon: Kennst du das Land / Hugo Wolf -- [Track 13]. From Song of Almah. III. Cedar of Lebanon / Andrew Beall

A Self-Supervised Automatic Post-Editing Data Generation Tool

Data building for automatic post-editing (APE) requires extensive and expert-level human effort, as it contains an elaborate process that involves identifying errors in sentences and providing suitable revisions. Hence, we develop a self-supervised data generation tool, deployable as a web application, that minimizes human supervision and constructs personalized APE data from a parallel corpus for several language pairs with English as the target language. Data-centric APE research can be conducted using this tool, involving many language pairs that have not been studied thus far owing to the lack of suitable data.Comment: Accepted for DataPerf workshop at ICML 202

QUAK: A Synthetic Quality Estimation Dataset for Korean-English Neural Machine Translation

With the recent advance in neural machine translation demonstrating its importance, research on quality estimation (QE) has been steadily progressing. QE aims to automatically predict the quality of machine translation (MT) output without reference sentences. Despite its high utility in the real world, there remain several limitations concerning manual QE data creation: inevitably incurred non-trivial costs due to the need for translation experts, and issues with data scaling and language expansion. To tackle these limitations, we present QUAK, a Korean-English synthetic QE dataset generated in a fully automatic manner. This consists of three sub-QUAK datasets QUAK-M, QUAK-P, and QUAK-H, produced through three strategies that are relatively free from language constraints. Since each strategy requires no human effort, which facilitates scalability, we scale our data up to 1.58M for QUAK-P, H and 6.58M for QUAK-M. As an experiment, we quantitatively analyze word-level QE results in various ways while performing statistical analysis. Moreover, we show that datasets scaled in an efficient way also contribute to performance improvements by observing meaningful performance gains in QUAK-M, P when adding data up to 1.58M

Exploring valid reference genes for gene expression studies in Brachypodium distachyon by real-time PCR

<p>Abstract</p> <p>Background</p> <p>The wild grass species <it>Brachypodium distachyon </it>(Brachypodium hereafter) is emerging as a new model system for grass crop genomics research and biofuel grass biology. A draft nuclear genome sequence is expected to be publicly available in the near future; an explosion of gene expression studies will undoubtedly follow. Therefore, stable reference genes are necessary to normalize the gene expression data.</p> <p>Results</p> <p>A systematic exploration of suitable reference genes in Brachypodium is presented here. Nine reference gene candidates were chosen, and their gene sequences were obtained from the Brachypodium expressed sequence tag (EST) databases. Their expression levels were examined by quantitative real-time PCR (qRT-PCR) using 21 different Brachypodium plant samples, including those from different plant tissues and grown under various growth conditions. Effects of plant growth hormones were also visualized in the assays. The expression stability of the candidate genes was evaluated using two analysis software packages, geNorm and NormFinder. In conclusion, the ubiquitin-conjugating enzyme 18 gene (<it>UBC18</it>) was validated as a suitable reference gene across all the plant samples examined. While the expression of the polyubiquitin genes (<it>Ubi4 </it>and <it>Ubi10</it>) was most stable in different plant tissues and growth hormone-treated plant samples, the expression of the S-adenosylmethionine decarboxylase gene (<it>SamDC</it>) ranked was most stable in plants grown under various environmental stresses.</p> <p>Conclusion</p> <p>This study identified the reference genes that are most suitable for normalizing the gene expression data in Brachypodium. These reference genes will be particularly useful when stress-responsive genes are analyzed in order to produce transgenic plants that exhibit enhanced stress resistance.</p

Functional elements demarcated by histone modifications in breast cancer cells

AbstractHistone modifications are regarded as one of markers to identify regulatory elements which are DNA segments modulating gene transcription. Aberrant changes of histone modification levels are frequently observed in cancer. We have employed ChIP-Seq to identify regulatory elements in human breast cancer cell line, MCF-7 by comparing histone modification patterns of H3K4me1, H3K4me3, and H3K9/14ac to those in normal mammary epithelial cell line, MCF-10A. The genome-wide analysis shows that H3K4me3 and H3K9/14ac are highly enriched at promoter regions and H3K4me1 has a relatively broad distribution over proximity of TSSs as well as other genomic regions. We identified that many differentially expressed genes in MCF-7 have divergent histone modification patterns. To understand the functional roles of distinctively histone-modified regions, we selected 35 genomic regions marked by at least one histone modification and located from 3 to 10kb upstream of TSS in both MCF-7 and MCF-10A and assessed their transcriptional activities. About 66% and 60% of selected regions in MCF-7 and MCF-10A, respectively, enhanced the transcriptional activity. Interestingly, most regions marked by H3K4me1 exhibited an enhancer activity. Regions with two or more kinds of histone modifications did show varying activities. In conclusion, our data reflects that comprehensive analysis of histone modification profiles under cell type-specific chromatin environment should provide a better chance for defining functional regulatory elements in the genome