108 research outputs found
Stratified Transfer Learning for Cross-domain Activity Recognition
In activity recognition, it is often expensive and time-consuming to acquire
sufficient activity labels. To solve this problem, transfer learning leverages
the labeled samples from the source domain to annotate the target domain which
has few or none labels. Existing approaches typically consider learning a
global domain shift while ignoring the intra-affinity between classes, which
will hinder the performance of the algorithms. In this paper, we propose a
novel and general cross-domain learning framework that can exploit the
intra-affinity of classes to perform intra-class knowledge transfer. The
proposed framework, referred to as Stratified Transfer Learning (STL), can
dramatically improve the classification accuracy for cross-domain activity
recognition. Specifically, STL first obtains pseudo labels for the target
domain via majority voting technique. Then, it performs intra-class knowledge
transfer iteratively to transform both domains into the same subspaces.
Finally, the labels of target domain are obtained via the second annotation. To
evaluate the performance of STL, we conduct comprehensive experiments on three
large public activity recognition datasets~(i.e. OPPORTUNITY, PAMAP2, and UCI
DSADS), which demonstrates that STL significantly outperforms other
state-of-the-art methods w.r.t. classification accuracy (improvement of 7.68%).
Furthermore, we extensively investigate the performance of STL across different
degrees of similarities and activity levels between domains. And we also
discuss the potential of STL in other pervasive computing applications to
provide empirical experience for future research.Comment: 10 pages; accepted by IEEE PerCom 2018; full paper. (camera-ready
version
An integral gated mode single photon detector at telecom wavelengths
We demonstrate an integral gated mode single photon detector at telecom
wavelengths. The charge number of an avalanche pulse rather than the peak
current is monitored for single-photon detection. The transient spikes in
conventional gated mode operation are canceled completely by integrating, which
enables one to improve the performance of single photon detector greatly with
the same avalanche photodiode. This method has achieved a detection efficiency
of 29.9% at the dark count probability per gate equal to 5.57E-6/gate
(1.11E-6/ns) at 1550nm.Comment: word to PDF, 3 pages with 4 figure
Red teaming GPT-4V: are GPT-4V safe against uni/multi-modal jailbreak attacks?
Various jailbreak attacks have been proposed to red-team Large Language Models (LLMs) and revealed the vulnerable safeguards of LLMs. Besides, some methods are not limited to the textual modality and extend the jailbreak attack to Multimodal Large Language Models (MLLMs) by perturbing the visual input. However, the absence of a universal evaluation benchmark complicates the performance reproduction and fair comparison. Besides, there is a lack of comprehensive evaluation of closed-source state-of-the-art (SOTA) models, especially MLLMs, such as GPT-4V. To address these issues, this work first builds a comprehensive jailbreak evaluation dataset with 1445 harmful questions covering 11 different safety policies. Based on this dataset, extensive red-teaming experiments are conducted on 11 different LLMs and MLLMs, including both SOTA proprietary models and open-source models. We then conduct a deep analysis of the evaluated results and find that (1) GPT4 and GPT-4V demonstrate better robustness against jailbreak attacks compared to open-source LLMs and MLLMs. (2) Llama2 and Qwen-VL-Chat are more robust compared to other open-source models. (3) The transferability of visual jailbreak methods is relatively limited compared to textual jailbreak methods. The dataset and code can be found here
Stop reasoning! When multimodal LLMs with chain-of-thought reasoning meets adversarial images
Recently, Multimodal LLMs (MLLMs) have
shown a great ability to understand images. However, like traditional vision models, they are
still vulnerable to adversarial images. Meanwhile, Chain-of-Thought (CoT) reasoning has
been widely explored on MLLMs, which not only
improves model’s performance, but also enhances
model’s explainability by giving intermediate reasoning steps. Nevertheless, there is still a lack
of study regarding MLLMs’ adversarial robustness with CoT and an understanding of what the
rationale looks like when MLLMs infer wrong
answers with adversarial images. Our research
evaluates the adversarial robustness of MLLMs
when employing CoT reasoning, finding that
CoT marginally improves adversarial robustness
against existing attack methods. Moreover, we
introduce a novel stop-reasoning attack technique
that effectively bypasses the CoT-induced robustness enhancements. Finally, we demonstrate the
alterations in CoT reasoning when MLLMs confront adversarial images, shedding light on their
reasoning process under adversarial attacks
A Survey on Evaluation of Large Language Models
Large language models (LLMs) are gaining increasing popularity in both
academia and industry, owing to their unprecedented performance in various
applications. As LLMs continue to play a vital role in both research and daily
use, their evaluation becomes increasingly critical, not only at the task
level, but also at the society level for better understanding of their
potential risks. Over the past years, significant efforts have been made to
examine LLMs from various perspectives. This paper presents a comprehensive
review of these evaluation methods for LLMs, focusing on three key dimensions:
what to evaluate, where to evaluate, and how to evaluate. Firstly, we provide
an overview from the perspective of evaluation tasks, encompassing general
natural language processing tasks, reasoning, medical usage, ethics,
educations, natural and social sciences, agent applications, and other areas.
Secondly, we answer the `where' and `how' questions by diving into the
evaluation methods and benchmarks, which serve as crucial components in
assessing performance of LLMs. Then, we summarize the success and failure cases
of LLMs in different tasks. Finally, we shed light on several future challenges
that lie ahead in LLMs evaluation. Our aim is to offer invaluable insights to
researchers in the realm of LLMs evaluation, thereby aiding the development of
more proficient LLMs. Our key point is that evaluation should be treated as an
essential discipline to better assist the development of LLMs. We consistently
maintain the related open-source materials at:
https://github.com/MLGroupJLU/LLM-eval-survey.Comment: 23 page
Overexpression p21WAF1/CIP1 in suppressing retinal pigment epithelial cells and progression of proliferative vitreoretinopathy via inhibition CDK2 and cyclin E
Deficiency of FLCN in Mouse Kidney Led to Development of Polycystic Kidneys and Renal Neoplasia
The Birt–Hogg–Dubé (BHD) disease is a genetic cancer syndrome. The responsible gene, BHD, has been identified by positional cloning and thought to be a novel tumor suppressor gene. BHD mutations cause many types of diseases including renal cell carcinomas, fibrofolliculomas, spontaneous pneumothorax, lung cysts, and colonic polyps/cancers. By combining Gateway Technology with the Ksp-Cre gene knockout system, we have developed a kidney-specific BHD knockout mouse model. BHDflox/flox/Ksp-Cre mice developed enlarged kidneys characterized by polycystic kidneys, hyperplasia, and cystic renal cell carcinoma. The affected BHDflox/flox/Ksp-Cre mice died of renal failure at approximate three weeks of age, having blood urea nitrogen levels over tenfold higher than those of BHD flox/+/Ksp-Cre and wild-type littermate controls. We further demonstrated that these phenotypes were caused by inactivation of BHD and subsequent activation of the mTOR pathway. Application of rapamycin, which inhibits mTOR activity, to the affected mice led to extended survival and inhibited further progression of cystogenesis. These results provide a correlation of kidney-targeted gene inactivation with renal carcinoma, and they suggest that the BHD product FLCN, functioning as a cyst and tumor suppressor, like other hamartoma syndrome–related proteins such as PTEN, LKB1, and TSC1/2, is a component of the mTOR pathway, constituting a novel FLCN-mTOR signaling branch that regulates cell growth/proliferation
Electronic imaging applications in mobile healthcare
Information technology is changing healthcare systems in revolutionary ways; there can be no health care reform without an information revolution. One information technology that is transforming healthcare systems is mobile technology. As it develops and matures, mobile technology is having a significant impact on healthcare, and emerging mobile technologies are attracting significant attention as well as investment of time and effort among researchers and industrial developers. The combination of mobile technology with healthcare has produced an important research area called mHealth. In 2011, U.S. Secretary of Health and Human Services, Kathleen Sebelius, referred to mHealth as the biggest technology breakthrough of our time and maintained that its use would address our greatest national challenge. Based on related research, mobile health is projected to be a 26 billion dollar industry by 2017
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