1,264 research outputs found
Defect- and Variation-tolerant Logic Mapping in Nano-crossbar Using Bipartite Matching and Memetic Algorithm
Sequential Recommendation with Diffusion Models
Generative models, such as Variational Auto-Encoder (VAE) and Generative
Adversarial Network (GAN), have been successfully applied in sequential
recommendation. These methods require sampling from probability distributions
and adopt auxiliary loss functions to optimize the model, which can capture the
uncertainty of user behaviors and alleviate exposure bias. However, existing
generative models still suffer from the posterior collapse problem or the model
collapse problem, thus limiting their applications in sequential
recommendation. To tackle the challenges mentioned above, we leverage a new
paradigm of the generative models, i.e., diffusion models, and present
sequential recommendation with diffusion models (DiffRec), which can avoid the
issues of VAE- and GAN-based models and show better performance. While
diffusion models are originally proposed to process continuous image data, we
design an additional transition in the forward process together with a
transition in the reverse process to enable the processing of the discrete
recommendation data. We also design a different noising strategy that only
noises the target item instead of the whole sequence, which is more suitable
for sequential recommendation. Based on the modified diffusion process, we
derive the objective function of our framework using a simplification technique
and design a denoise sequential recommender to fulfill the objective function.
As the lengthened diffusion steps substantially increase the time complexity,
we propose an efficient training strategy and an efficient inference strategy
to reduce training and inference cost and improve recommendation diversity.
Extensive experiment results on three public benchmark datasets verify the
effectiveness of our approach and show that DiffRec outperforms the
state-of-the-art sequential recommendation models
L1-ORF1p and Ago2 are involved in a siRNA-mediated regulation for promoter activity of L1-5’UTR
Introduction. Long interspersed nuclear elements-1 (L1), as the only one self-active retrotransposon of the mobile element, was found to be generally activated in tumor cells. The 5‘UTR of L1 (L1-5’UTR) contains both sense and antisense bidirectional promoters, transcription products of which can generate double-strand RNA (dsRNA). In addition, L1-ORF1p, a dsRNA binding protein encoded by L1, is considered to engage in some RNA-protein (RNP) formation. Ago2, one of the RISC components, can bind to dsRNA to form RISC complex, but its role in L1 regulation still remains unclear. Due that the 5‘UTR of L1 (L1-5’UTR) contains both sense and antisense bidirectional promoters, so the activities in both string were identified. A dsRNA-mediated regulation of L1-5’UTR, with the feedback regulation of L1-ORF1p as well as other key molecules engaged (Ago1–4) in this process, was also investigated.
Material and methods. Genomic DNA was extracted from HEK293 cells and subjected to L1-5’UTR prepaÂration by PCR. Report gene system pIRESneo with SV40 promoter was employed. The promoter activities of different regions in L1-5’UTR were identified by constructing these regions into pIRESneo, which SV40 region was removed prior, to generate different recombinant plasmids. The promoter activities in recombinant plasmids were detected by the luciferase expression assay. Western blot and co-immunoprecipitation were employed to identify proteins expression and protein-protein interaction respectively.
Results. Ago2 is a member of Agos family, which usually forms a RISC complex with si/miRNA and is involved in post- transcriptional regulation of many genes. Here L1-ORF1p and Ago2 conducts a regulation as a negative feedback for L1-5'UTR sense promoter. L1-ORF1p could form the immune complexes with Ago1, Ago2 and Ago4, respectively.
Conclusions. L1-5’UTR harbors both sense and antisense promoter activity and a dsRNA-mediated regulation is responsible for L1-5’UTR regulation. Agos proteins and L1-ORF1p were engaged in this process
Performance Characteristics and Temperature Compensation Method of Fluid Property Sensor Based on Tuning-Fork Technology
Fluid property sensor (FPS) based on tuning-fork technology is applied to the measurement of the contaminant level of lubricant oil. The measuring principle of FPS sensor is derived and proved together with its resolution. The performance characteristics of the FPS sensor, such as sensitivity coefficient, resolution, and quality factor, are analyzed. A temperature compensation method is proposed to eliminate the temperature-dependence of the measuring parameters, and its validity is investigated by numerical simulation of sensitivity, oscillating frequency, and dielectric constant. The values of purification efficiency obtained using microwave and without microwave are compared experimentally
Frequency Enhanced Hybrid Attention Network for Sequential Recommendation
The self-attention mechanism, which equips with a strong capability of
modeling long-range dependencies, is one of the extensively used techniques in
the sequential recommendation field. However, many recent studies represent
that current self-attention based models are low-pass filters and are
inadequate to capture high-frequency information. Furthermore, since the items
in the user behaviors are intertwined with each other, these models are
incomplete to distinguish the inherent periodicity obscured in the time domain.
In this work, we shift the perspective to the frequency domain, and propose a
novel Frequency Enhanced Hybrid Attention Network for Sequential
Recommendation, namely FEARec. In this model, we firstly improve the original
time domain self-attention in the frequency domain with a ramp structure to
make both low-frequency and high-frequency information could be explicitly
learned in our approach. Moreover, we additionally design a similar attention
mechanism via auto-correlation in the frequency domain to capture the periodic
characteristics and fuse the time and frequency level attention in a union
model. Finally, both contrastive learning and frequency regularization are
utilized to ensure that multiple views are aligned in both the time domain and
frequency domain. Extensive experiments conducted on four widely used benchmark
datasets demonstrate that the proposed model performs significantly better than
the state-of-the-art approaches.Comment: 11 pages, 7 figures, The 46th International ACM SIGIR Conference on
Research and Development in Information Retrieva
Intent Contrastive Learning with Cross Subsequences for Sequential Recommendation
The user purchase behaviors are mainly influenced by their intentions (e.g.,
buying clothes for decoration, buying brushes for painting, etc.). Modeling a
user's latent intention can significantly improve the performance of
recommendations. Previous works model users' intentions by considering the
predefined label in auxiliary information or introducing stochastic data
augmentation to learn purposes in the latent space. However, the auxiliary
information is sparse and not always available for recommender systems, and
introducing stochastic data augmentation may introduce noise and thus change
the intentions hidden in the sequence. Therefore, leveraging user intentions
for sequential recommendation (SR) can be challenging because they are
frequently varied and unobserved. In this paper, Intent contrastive learning
with Cross Subsequences for sequential Recommendation (ICSRec) is proposed to
model users' latent intentions. Specifically, ICSRec first segments a user's
sequential behaviors into multiple subsequences by using a dynamic sliding
operation and takes these subsequences into the encoder to generate the
representations for the user's intentions. To tackle the problem of no explicit
labels for purposes, ICSRec assumes different subsequences with the same target
item may represent the same intention and proposes a coarse-grain intent
contrastive learning to push these subsequences closer. Then, fine-grain intent
contrastive learning is mentioned to capture the fine-grain intentions of
subsequences in sequential behaviors. Extensive experiments conducted on four
real-world datasets demonstrate the superior performance of the proposed ICSRec
model compared with baseline methods.Comment: 10pages, 5figures, WSDM2024. arXiv admin note: text overlap with
arXiv:2304.0776
Development of a SCAR Marker for Rapid Identification of New Kentucky Bluegrass Breeding Lines
As a commonly used turfgrass, Kentucky bluegrass (Poa pratensis L.) (KBG) has many commercially available cultivars for production. After several years of screening, two new lines were obtained (‘KBG03’ and ‘KBG04’), which have high tolerance to summer. The study showed that the two lines revealed similar morphological characteristics, with light green leaf color, narrow leaf blade, high plant height and light 1,000-grain weight. A total of 400 random amplified polymorphic DNA (RAPD) primers and 256 sequence-related amplified polymorphism (SRAP) primer combinations were screened among the two lines and other 4 imported commercial cultivars. The percentages of polymorphic sites were 65.5% (RAPD) and 22.6% (SRAP) respectively. By cluster analysis of RAPD and SRAP data, the dendrogram at a similarity of 0.29 gave two main clusters, of which one group had 4 commercial cultivars, and the other had the two new breeding lines. Furthermore, one specific band of ‘KBG04’ was successfully converted into a dominant sequence characterized amplified region marker (SCAR196). Then the SCAR marker was verified by 39 KBG DNA samples, including imported varieties, domestic varieties and self-breeding lines of our laboratory, and it exhibited high consistency with the original RAPD polymorphic amplification. The results showed that the SCAR marker can be used to distinguish the new line ‘KBG04’ from numerous KBG germplasms, which would be useful for cultivar identification and property rights protection in the future
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