1,020 research outputs found
Truth-Valued-Flow Inference (TVFI) and its applications in approximate reasoning
The framework of the theory of Truth-valued-flow Inference (TVFI) is introduced. Even though there are dozens of papers presented on fuzzy reasoning, we think it is still needed to explore a rather unified fuzzy reasoning theory which has the following two features: (1) it is simplified enough to be executed feasibly and easily; and (2) it is well structural and well consistent enough that it can be built into a strict mathematical theory and is consistent with the theory proposed by L.A. Zadeh. TVFI is one of the fuzzy reasoning theories that satisfies the above two features. It presents inference by the form of networks, and naturally views inference as a process of truth values flowing among propositions
Rate-Splitting with Hybrid Messages: DoF Analysis of the Two-User MIMO Broadcast Channel with Imperfect CSIT
Most of the existing research on degrees-of-freedom (DoF) with imperfect
channel state information at the transmitter (CSIT) assume the messages are
private, which may not reflect reality as the two receivers can request the
same content. To overcome this limitation, we consider hybrid private and
common messages. We characterize the optimal DoF region for the two-user
multiple-input multiple-output (MIMO) broadcast channel with hybrid messages
and imperfect CSIT. We establish a three-step procedure for the DoF converse to
exploit the utmost possible relaxation. For the DoF achievability, since the
DoF region has a specific three-dimensional structure w.r.t. antenna
configurations and CSIT qualities, by dividing CSIT qualities into cases, we
check the existence of corner point solutions, and then design a hybrid
messages-aware rate-splitting scheme to achieve them. Besides, we show that to
achieve the strictly positive corner points, it is unnecessary to split the
private messages into unicast and multicast parts because the allocated power
for the multicast part should be zero. This implies that adding a common
message can mitigate the rate-splitting complexity of private messages.Comment: 32page
Bridging the Gap Between Indexing and Retrieval for Differentiable Search Index with Query Generation
The Differentiable Search Index (DSI) is an emerging paradigm for information
retrieval. Unlike traditional retrieval architectures where index and retrieval
are two different and separate components, DSI uses a single transformer model
to perform both indexing and retrieval.
In this paper, we identify and tackle an important issue of current DSI
models: the data distribution mismatch that occurs between the DSI indexing and
retrieval processes. Specifically, we argue that, at indexing, current DSI
methods learn to build connections between the text of long documents and the
identifier of the documents, but then retrieval of document identifiers is
based on queries that are commonly much shorter than the indexed documents.
This problem is further exacerbated when using DSI for cross-lingual retrieval,
where document text and query text are in different languages.
To address this fundamental problem of current DSI models, we propose a
simple yet effective indexing framework for DSI, called DSI-QG. When indexing,
DSI-QG represents documents with a number of potentially relevant queries
generated by a query generation model and re-ranked and filtered by a
cross-encoder ranker. The presence of these queries at indexing allows the DSI
models to connect a document identifier to a set of queries, hence mitigating
data distribution mismatches present between the indexing and the retrieval
phases. Empirical results on popular mono-lingual and cross-lingual passage
retrieval datasets show that DSI-QG significantly outperforms the original DSI
model.Comment: 11 page
Typos-aware Bottlenecked Pre-Training for Robust Dense Retrieval
Current dense retrievers (DRs) are limited in their ability to effectively
process misspelled queries, which constitute a significant portion of query
traffic in commercial search engines. The main issue is that the pre-trained
language model-based encoders used by DRs are typically trained and fine-tuned
using clean, well-curated text data. Misspelled queries are typically not found
in the data used for training these models, and thus misspelled queries
observed at inference time are out-of-distribution compared to the data used
for training and fine-tuning. Previous efforts to address this issue have
focused on \textit{fine-tuning} strategies, but their effectiveness on
misspelled queries remains lower than that of pipelines that employ separate
state-of-the-art spell-checking components. To address this challenge, we
propose ToRoDer (TypOs-aware bottlenecked pre-training for RObust DEnse
Retrieval), a novel re-training strategy for DRs that increases their
robustness to misspelled queries while preserving their effectiveness in
downstream retrieval tasks. ToRoDer utilizes an encoder-decoder architecture
where the encoder takes misspelled text with masked tokens as input and outputs
bottlenecked information to the decoder. The decoder then takes as input the
bottlenecked embeddings, along with token embeddings of the original text with
the misspelled tokens masked out. The pre-training task is to recover the
masked tokens for both the encoder and decoder. Our extensive experimental
results and detailed ablation studies show that DRs pre-trained with ToRoDer
exhibit significantly higher effectiveness on misspelled queries, sensibly
closing the gap with pipelines that use a separate, complex spell-checker
component, while retaining their effectiveness on correctly spelled queries.Comment: 10 pages, accepted at SIGIR-A
Re-evaluation of the carcinogenic significance of hepatitis B virus integration in hepatocarcinogenesis
To examine the role of hepatitis B virus (HBV) integration in hepatocarcinogenesis, a systematic comparative study of both tumor and their corresponding non-tumor derived tissue has been conducted in a cohort of 60 HBV associated hepatocellular carcinoma (HCC) patients. By using Alu-polymerase chain reaction (PCR) and ligation-mediated PCR, 233 viral-host junctions mapped across all human chromosomes at random, no difference between tumor and non-tumor tissue was observed, with the exception of fragile sites (P = 0.0070). HBV insertions in close proximity to cancer related genes such as hTERT were found in this study, however overall they were rare events. No direct correlation between chromosome aberrations and the number of HBV integration events was found using a sensitive array-based comparative genomic hybridization (aCGH) assay. However, a positive correlation was observed between the status of several tumor suppressor genes (TP53, RB1, CDNK2A and TP73) and the number of chromosome aberrations (r = 0.6625, P = 0.0003). Examination of the viral genome revealed that 43% of inserts were in the preC/C region and 57% were in the HBV X gene. Strikingly, approximately 24% of the integrations examined had a breakpoint in a short 15 nt viral genome region (1820-1834 nt). As a consequence, all of the confirmed X gene insertions were C-terminal truncated, losing their growth-suppressive domain. However, the same pattern of X gene C-terminal truncation was found in both tumor and non-tumor derived samples. Furthermore, the integrated viral sequences in both groups had a similar low frequency of C1653T, T1753V and A1762T/G1764A mutations. The frequency and patterns of HBV insertions were similar between tumor and their adjacent non-tumor samples indicating that the majority of HBV DNA integration events are not associated with hepatocarcinogenesis
Low-carbon economic scheduling of virtual power plant considering carbon emission flow and demand response
To fully explore the potential low-carbon and economic advantages of a virtual power plant (VPP) that aggregates multiple distributed resources, the paper proposes a VPP scheduling model that considers the carbon emission flow (CEF) and demand response (DR), which is characterized by electro-carbon coupling and source-load interaction. First, the electric-carbon characteristics of each distributed resource under VPP are modeled, and the source-load electric-carbon coupling characteristic model is modeled through the CEF theory. On this basis, a load-side multi-type DR model is established to achieve the purpose of source-load synergy to reduce carbon emissions from VPP. To this end, a two-stage scheduling model of VPP considering the source-load electro-carbon coupling relationship is established, and the implementation of the model can reduce power generation costs, carbon emissions and promote clean energy, and the simulation results of the improved IEEE-14 node system verify the effectiveness of the proposed model
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