78 research outputs found
Fooling an Unbounded Adversary with a Short Key, Repeatedly: The Honey Encryption Perspective
This article is motivated by the classical results from Shannon that put the simple and elegant one-time pad away from practice: key length has to be as large as message length and the same key could not be used more than once. In particular, we consider encryption algorithm to be defined relative to specific message distributions in order to trade for unconditional security. Such a notion named honey encryption (HE) was originally proposed for achieving best possible security for password based encryption where secrete key may have very small amount of entropy.
Exploring message distributions as in HE indeed helps circumvent the classical restrictions on secret keys.We give a new and very simple honey encryption scheme satisfying the unconditional semantic security (for the targeted message distribution) in the standard model (all previous constructions are in the random oracle model, even for message recovery security only). Our new construction can be paired with an extremely simple yet "tighter" analysis, while all previous analyses (even for message recovery security only) were fairly complicated and require stronger assumptions. We also show a concrete instantiation further enables the secret key to be used for encrypting multiple messages
Particle swarm optimization with state-based adaptive velocity limit strategy
Velocity limit (VL) has been widely adopted in many variants of particle
swarm optimization (PSO) to prevent particles from searching outside the
solution space. Several adaptive VL strategies have been introduced with which
the performance of PSO can be improved. However, the existing adaptive VL
strategies simply adjust their VL based on iterations, leading to
unsatisfactory optimization results because of the incompatibility between VL
and the current searching state of particles. To deal with this problem, a
novel PSO variant with state-based adaptive velocity limit strategy (PSO-SAVL)
is proposed. In the proposed PSO-SAVL, VL is adaptively adjusted based on the
evolutionary state estimation (ESE) in which a high value of VL is set for
global searching state and a low value of VL is set for local searching state.
Besides that, limit handling strategies have been modified and adopted to
improve the capability of avoiding local optima. The good performance of
PSO-SAVL has been experimentally validated on a wide range of benchmark
functions with 50 dimensions. The satisfactory scalability of PSO-SAVL in
high-dimension and large-scale problems is also verified. Besides, the merits
of the strategies in PSO-SAVL are verified in experiments. Sensitivity analysis
for the relevant hyper-parameters in state-based adaptive VL strategy is
conducted, and insights in how to select these hyper-parameters are also
discussed.Comment: 33 pages, 8 figure
Feature-aware conditional GAN for category text generation
Category text generation receives considerable attentions since it is
beneficial for various natural language processing tasks. Recently, the
generative adversarial network (GAN) has attained promising performance in text
generation, attributed to its adversarial training process. However, there are
several issues in text GANs, including discreteness, training instability, mode
collapse, lack of diversity and controllability etc. To address these issues,
this paper proposes a novel GAN framework, the feature-aware conditional GAN
(FA-GAN), for controllable category text generation. In FA-GAN, the generator
has a sequence-to-sequence structure for improving sentence diversity, which
consists of three encoders including a special feature-aware encoder and a
category-aware encoder, and one relational-memory-core-based decoder with the
Gumbel SoftMax activation function. The discriminator has an additional
category classification head. To generate sentences with specified categories,
the multi-class classification loss is supplemented in the adversarial
training. Comprehensive experiments have been conducted, and the results show
that FA-GAN consistently outperforms 10 state-of-the-art text generation
approaches on 6 text classification datasets. The case study demonstrates that
the synthetic sentences generated by FA-GAN can match the required categories
and are aware of the features of conditioned sentences, with good readability,
fluency, and text authenticity.Comment: 27 pages, 8 figure
Data-Driven Modeling with Experimental Augmentation for the Modulation Strategy of the Dual-Active-Bridge Converter
For the performance modeling of power converters, the mainstream approaches
are essentially knowledge-based, suffering from heavy manpower burden and low
modeling accuracy. Recent emerging data-driven techniques greatly relieve human
reliance by automatic modeling from simulation data. However, model discrepancy
may occur due to unmodeled parasitics, deficient thermal and magnetic models,
unpredictable ambient conditions, etc. These inaccurate data-driven models
based on pure simulation cannot represent the practical performance in physical
world, hindering their applications in power converter modeling. To alleviate
model discrepancy and improve accuracy in practice, this paper proposes a novel
data-driven modeling with experimental augmentation (D2EA), leveraging both
simulation data and experimental data. In D2EA, simulation data aims to
establish basic functional landscape, and experimental data focuses on matching
actual performance in real world. The D2EA approach is instantiated for the
efficiency optimization of a hybrid modulation for neutral-point-clamped
dual-active-bridge (NPC-DAB) converter. The proposed D2EA approach realizes
99.92% efficiency modeling accuracy, and its feasibility is comprehensively
validated in 2-kW hardware experiments, where the peak efficiency of 98.45% is
attained. Overall, D2EA is data-light and can achieve highly accurate and
highly practical data-driven models in one shot, and it is scalable to other
applications, effortlessly.Comment: 11 page
Erratum: Jiang et al. Localization accuracy of ultrasound-actuated needle with color doppler imaging. :<i>Diagnostics</i> 2020, <i>10</i>, 1020
Localization Accuracy of Ultrasound-Actuated Needle with Color Doppler Imaging
An ultrasonic needle-actuating device for tissue biopsy and regional anaesthesia offers enhanced needle visibility with color Doppler imaging. However, its specific performance is not yet fully determined. This work investigated the influence on needle visibility of the insertion angle and drive voltage, as well as determined the accuracy and agreement of needle tip localization by comparing color Doppler measurements with paired photographic and B-mode ultrasound measurements. Needle tip accuracy measurements in a gelatin phantom gave a regression trend, where the slope of trend is 0.8808; coefficient of determination (R2) is 0.8877; bias is −0.50 mm; and the 95% limits of agreement are from −1.31 to 0.31 mm when comparing color Doppler with photographic measurements. When comparing the color Doppler with B-mode ultrasound measurements, the slope of the regression trend is 1.0179; R2 is 0.9651; bias is −0.16 mm; and the 95% limits of agreement are from −1.935 to 1.605 mm. The results demonstrate the accuracy of this technique and its potential for application to biopsy and ultrasound guided regional anaesthesia
Unlock Multi-Modal Capability of Dense Retrieval via Visual Module Plugin
This paper proposes Multi-modAl Retrieval model via Visual modulE pLugin
(MARVEL) to learn an embedding space for queries and multi-modal documents to
conduct retrieval. MARVEL encodes queries and multi-modal documents with a
unified encoder model, which helps to alleviate the modality gap between images
and texts. Specifically, we enable the image understanding ability of a
well-trained dense retriever, T5-ANCE, by incorporating the image features
encoded by the visual module as its inputs. To facilitate the multi-modal
retrieval tasks, we build the ClueWeb22-MM dataset based on the ClueWeb22
dataset, which regards anchor texts as queries, and exact the related texts and
image documents from anchor linked web pages. Our experiments show that MARVEL
significantly outperforms the state-of-the-art methods on the multi-modal
retrieval dataset WebQA and ClueWeb22-MM. Our further analyses show that the
visual module plugin method is tailored to enable the image understanding
ability for an existing dense retrieval model. Besides, we also show that the
language model has the ability to extract image semantics from image encoders
and adapt the image features in the input space of language models. All codes
are available at https://github.com/OpenMatch/MARVEL
Association of psychological symptoms with job burnout and occupational stress among coal miners in Xinjiang, China: A cross-sectional study
ObjectiveThe study aimed to investigate the influencing factors of psychological symptoms in relation to job burnout and occupational stress among coal miners in Xinjiang, so as to provide data support for enterprises in an effort to help them identify internal psychological risk factors and improve the mental health of coal miners.MethodsA cross-sectional study was carried out. A total of 12 coal mines were selected using the stratified cluster random sampling method and 4,109 coal miners were investigated by means of online electronic questionnaires. The Symptoms Check List-90 (SCL-90), Chinese Maslach Burnout Inventory (CMBI), and Job Demand-Control (JDC) model were respectively used to measure the status of psychological symptoms, job burnout, and occupational stress among coal miners. The mediation analysis was performed through structural equation modeling (SEM) by using Analysis of Moment Structure (AMOS).ResultsThe prevalence of psychological symptoms was higher in the occupational stress group than in the non-occupational stress group, and increased with job burnout (P < 0.05). The multivariate logistic regression analysis results showed that mild (OR = 1.401, 95% CL: 1.165, 1.685), moderate (OR = 2.190, 95% CL: 1.795, 2.672), or severe levels of burnout (OR = 6.102, 95% CL: 3.481, 10.694) and occupational stress (OR = 1.462, 95% CL: 1.272, 1.679) were risk factors for psychological symptoms in coal miners. The results of structural equation modeling indicated that occupational stress (β = 0.11, P = 0.002) and job burnout (β = 0.46, P = 0.002) had significant positive direct effects on psychological symptoms, and job burnout was an intermediate variable between occupational stress and psychological symptoms.ConclusionHigh levels of job burnout and occupational stress were risk factors for psychological symptoms. Both occupational stress and job burnout had direct effects on psychological symptoms, and occupational stress could also have an indirect effect on coal miners' psychological symptoms through the intermediate variable of job burnout
Development of a Novel Restrictive Medium for Monascus Enrichment From Hongqu Based on the Synergistic Stress of Lactic Acid and Ethanol
Hongqu is a famous fermented food produced by Monascus and has been used as food coloring, wine starters and food additives for thousands of years in China. Excellent Monascus strain is an important prerequisite for producing high-quality Hongqu. However, the isolation of Monascus pure culture from Hongqu samples is time-consuming and laborious because it is easily interfered by other microorganisms (especially filamentous fungi). Therefore, the development of restrictive medium for Monascus enrichment from Hongqu is of great significance for the preparation and screening of excellent Monascus strains. Results of this study showed that Monascus has good tolerance to lactic acid and ethanol. Under the conditions of tolerance limits [7.5% lactic acid (v/v) and 12.0% ethanol (v/v)], Monascus could not grow but it still retained the vitality of spore germination, and the spore activity gradually decreased with the increasing concentrations of lactic acid and ethanol. More interestingly, the addition of lactic acid and ethanol significantly changed the microbial community structure in rice milk inoculated with Hongqu. After response surface optimization, Monascus could be successfully enriched without the interference of other microorganisms when 3.98% (v/v) lactic acid and 6.24% (v/v) ethanol were added to rice milk simultaneously. The optimal enrichment duration of Monascus by the restrictive medium based on the synergistic stress of lactic acid and ethanol is 8∼24 h. The synergistic stress of lactic acid and ethanol had no obvious effects on the accumulation of major metabolites in the progeny of Monascus, and was suitable for the enrichment of Monascus from different types of Hongqu. Finally, the possible mechanisms on the tolerance of Monascus to the synergistic stress of lactic acid and ethanol were preliminarily studied. Under the synergistic stress of lactic acid and ethanol, the cell membrane of Monascus defends against lactic acid and ethanol into cells to some extent, and the superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) activities of Monascus were higher than those of other fungi, which significantly reduced the degree of lipid peroxidation of cell membrane, while secreting more amylase to make reducing sugars to provide the cells with enough energy to resist environmental stress. This work has great application value for the construction of Monascus strain library and the better development of its germplasm resources
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