302 research outputs found
Energy-Water Balance and Ecosystem Response to Climate Change in Southwest China
It is important to highlight energy-water balance and ecosystem response to climate changes. The change of water-energy balance and ecosystem due to climate change will affect the regional ecological and human living significantly, especially in Southwest China which is an ecologically fragile area. This chapter presents the retrieval methodology of parameters (reconstruction of vegetation index, land cover semi-automatic classification, a time series reconstruction of land surface temperature based on Kalman filter and precipitation interpolation based on thin plate smoothing splines), time-series analysis methodology (land cover change, vegetation succession and drought index) and correlate analysis methodology (correlation coefficient and principal component analysis). Then, based on the above method, remote sensing data were integrated, a time series analysis on a 30-year data was used to illustrate the water-energy balance and ecosystem variability in Southwest China. The result showed that energy-water balance and ecosystem (ecosystem structures, vegetation and droughts) have severe response to climate change
HiQA: A Hierarchical Contextual Augmentation RAG for Massive Documents QA
As language model agents leveraging external tools rapidly evolve,
significant progress has been made in question-answering(QA) methodologies
utilizing supplementary documents and the Retrieval-Augmented Generation (RAG)
approach. This advancement has improved the response quality of language models
and alleviates the appearance of hallucination. However, these methods exhibit
limited retrieval accuracy when faced with massive indistinguishable documents,
presenting notable challenges in their practical application. In response to
these emerging challenges, we present HiQA, an advanced framework for
multi-document question-answering (MDQA) that integrates cascading metadata
into content as well as a multi-route retrieval mechanism. We also release a
benchmark called MasQA to evaluate and research in MDQA. Finally, HiQA
demonstrates the state-of-the-art performance in multi-document environments
Learning One-Shot Exemplar SVM from the Web for Face Verification
Abstract. We investigate the problem of learning from a single instance consisting of a pair of images, often encountered in unconstrained face verification where the pair of images to be verified contain large varia-tions and are captured from never seen subjects. Instead of constructing a separate discriminative model for each image in the couple and perform-ing cross-checking, we learn a single Exemplar-SVM model for the pair by augmenting it with a negative couple set, and then predict whether the pair are from the same subject or not by asking an oracle whether this Exemplar-SVM is for a client or imposter in nature. The oracle by itself is learnt from the behaviors of a large number of Exemplar-SVMs based on the labeled background set. For face representation we use a number of unlabeled face sets collected from the Web to train a series of decision stumps that jointly map a given face to a discriminative and distributional representation. Experiments on the challenging Labeled Faces in the Wild (LFW) verify the effectiveness and feasibility of the proposed method.
Unsupervised Cross-spectral Stereo Matching by Learning to Synthesize
Unsupervised cross-spectral stereo matching aims at recovering disparity
given cross-spectral image pairs without any supervision in the form of ground
truth disparity or depth. The estimated depth provides additional information
complementary to individual semantic features, which can be helpful for other
vision tasks such as tracking, recognition and detection. However, there are
large appearance variations between images from different spectral bands, which
is a challenge for cross-spectral stereo matching. Existing deep unsupervised
stereo matching methods are sensitive to the appearance variations and do not
perform well on cross-spectral data. We propose a novel unsupervised
cross-spectral stereo matching framework based on image-to-image translation.
First, a style adaptation network transforms images across different spectral
bands by cycle consistency and adversarial learning, during which appearance
variations are minimized. Then, a stereo matching network is trained with image
pairs from the same spectra using view reconstruction loss. At last, the
estimated disparity is utilized to supervise the spectral-translation network
in an end-to-end way. Moreover, a novel style adaptation network F-cycleGAN is
proposed to improve the robustness of spectral translation. Our method can
tackle appearance variations and enhance the robustness of unsupervised
cross-spectral stereo matching. Experimental results show that our method
achieves good performance without using depth supervision or explicit semantic
information.Comment: accepted by AAAI-1
SPECTRUM: Speaker-Enhanced Pre-Training for Long Dialogue Summarization
Multi-turn dialogues are characterized by their extended length and the
presence of turn-taking conversations. Traditional language models often
overlook the distinct features of these dialogues by treating them as regular
text. In this paper, we propose a speaker-enhanced pre-training method for long
dialogue summarization, which leverages the inherent structure of multiple-turn
dialogues. To support our study, we curate a diverse dataset that includes
transcripts from real-world scenarios, movie or TV show transcripts, and
dialogues generated by a Large Language Model. We then perform a pre-training,
which encompasses the detection of speaker changes, and masked utterance
generation. Experimental results of fine-tuned models demonstrate that our
model achieves state-of-the-art performance on downstream benchmarks with long
context, surpassing baseline models and highlighting the effectiveness of our
approach. Our findings highlight the importance of curating pre-training
datasets that exhibit diversity and variations in length distribution to ensure
effective alignment with downstream datasets.Comment: 11 pages, 2 figure
DecipherPref: Analyzing Influential Factors in Human Preference Judgments via GPT-4
Human preference judgments are pivotal in guiding large language models
(LLMs) to produce outputs that align with human values. Human evaluations are
also used in summarization tasks to compare outputs from various systems,
complementing existing automatic metrics. Despite their significance, however,
there has been limited research probing these pairwise or -wise comparisons.
The collective impact and relative importance of factors such as output length,
informativeness, fluency, and factual consistency are still not well
understood. It is also unclear if there are other hidden factors influencing
human judgments. In this paper, we conduct an in-depth examination of a
collection of pairwise human judgments released by OpenAI. Utilizing the
Bradley-Terry-Luce (BTL) model, we reveal the inherent preferences embedded in
these human judgments. We find that the most favored factors vary across tasks
and genres, whereas the least favored factors tend to be consistent, e.g.,
outputs are too brief, contain excessive off-focus content or hallucinated
facts. Our findings have implications on the construction of balanced datasets
in human preference evaluations, which is a crucial step in shaping the
behaviors of future LLMs
Polarity Calibration for Opinion Summarization
Opinion summarization is automatically generating summaries from a variety of
subjective information, such as product reviews or political opinions. The
challenge of opinions summarization lies in presenting divergent or even
conflicting opinions. We conduct an analysis of previous summarization models,
which reveals their inclination to amplify the polarity bias, emphasizing the
majority opinions while ignoring the minority opinions. To address this issue
and make the summarizer express both sides of opinions, we introduce the
concept of polarity calibration, which aims to align the polarity of output
summary with that of input text. Specifically, we develop a reinforcement
training approach for polarity calibration. This approach feeds the polarity
distance between output summary and input text as reward into the summarizer,
and also balance polarity calibration with content preservation and language
naturality. We evaluate our Polarity Calibration model (PoCa) on two types of
opinions summarization tasks: summarizing product reviews and political
opinions articles. Automatic and human evaluation demonstrate that our approach
can mitigate the polarity mismatch between output summary and input text, as
well as maintain the content semantic and language quality.Comment: Accepted to NAACL 202
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