Research on Multi-Agent Simulation of Epidemic News Spread Characteristics

The spread of news about an epidemic can easily lead to a social panic. In order to devise measures to control such a panic, it is necessary to consider characteristics of the spread of epidemic news, based on mechanisms at the individual level. In this paper, first, some features of multi-agent simulation are reviewed. Then a multi-agent simulation model of epidemic news spread (ENS) is designed and realized. Based on simulation experiments and sensitivity analyses, the influence of social relationships, the degree of trust in news of the epidemic, the epidemic spread intensity and the network structure of the epidemic news spread are studied. The research results include: (1) As the number of social relationships increases, the rate of spread of epidemic news rapidly rises, and the ratio of people who have heard the news directly decreases. The result is that the \'radiation effect\' of the epidemic news spread will be enhanced when the number of social relationships increases. (2) With the increase of the degree of trust in the news, the rate of spread of the news will also rapidly increase, but variation in the ratio of the people who have heard the news directly is not significant. This means that the \'radiation effect\' of the spread of the news does not change much more in relation to the degree of trust in the epidemic news. (3) The ratio of the people who have heard the news directly increases when the infection range increases (i.e. the spread intensity of epidemic increases), and vice versa. But the variation of the speed of the epidemic news spread is not significant. (4) When the network structure is assumed to be a small world network, the spread speed will be slower than that in a random network with the same average vertex degree and the forgetting speed will be faster than that in a random network with the same average vertex degree.Multi-Agent Simulation, News Spread, Small World Network , Epidemic

Adiabatic Creation of Atomic Squeezing in Dark States vs. Decoherences

We study the multipartite correlations of the multi-atom dark states, which are characterized by the atomic squeezing beyond the pairwise entanglement. It is shown that, in the photon storage process with atomic ensemble via electromagnetically induced transparency (EIT) mechanism, the atomic squeezing and the pairwise entanglement can be created by adiabatically manipulating the Rabi frequency of the classical light field on the atomic ensemble. We also consider the sudden death for the atomic squeezing and the pairwise entanglement under various decoherence channels. An optimal time for generating the greatest atomic squeezing and pairwise entanglement is obtained by studying in details the competition between the adiabatic creation of quantum correlation in the atomic ensemble and the decoherence that we describe with three typical decoherence channels.Comment: 11 pages, 13 figure

RecolorNeRF: Layer Decomposed Radiance Fields for Efficient Color Editing of 3D Scenes

Radiance fields have gradually become a main representation of media. Although its appearance editing has been studied, how to achieve view-consistent recoloring in an efficient manner is still under explored. We present RecolorNeRF, a novel user-friendly color editing approach for the neural radiance fields. Our key idea is to decompose the scene into a set of pure-colored layers, forming a palette. By this means, color manipulation can be conducted by altering the color components of the palette directly. To support efficient palette-based editing, the color of each layer needs to be as representative as possible. In the end, the problem is formulated as an optimization problem, where the layers and their blending weights are jointly optimized with the NeRF itself. Extensive experiments show that our jointly-optimized layer decomposition can be used against multiple backbones and produce photo-realistic recolored novel-view renderings. We demonstrate that RecolorNeRF outperforms baseline methods both quantitatively and qualitatively for color editing even in complex real-world scenes.Comment: To appear in ACM Multimedia 2023. Project website is accessible at https://sites.google.com/view/recolorner

ME-PCN: Point Completion Conditioned on Mask Emptiness

Point completion refers to completing the missing geometries of an object from incomplete observations. Main-stream methods predict the missing shapes by decoding a global feature learned from the input point cloud, which often leads to deficient results in preserving topology consistency and surface details. In this work, we present ME-PCN, a point completion network that leverages `emptiness' in 3D shape space. Given a single depth scan, previous methods often encode the occupied partial shapes while ignoring the empty regions (e.g. holes) in depth maps. In contrast, we argue that these `emptiness' clues indicate shape boundaries that can be used to improve topology representation and detail granularity on surfaces. Specifically, our ME-PCN encodes both the occupied point cloud and the neighboring `empty points'. It estimates coarse-grained but complete and reasonable surface points in the first stage, followed by a refinement stage to produce fine-grained surface details. Comprehensive experiments verify that our ME-PCN presents better qualitative and quantitative performance against the state-of-the-art. Besides, we further prove that our `emptiness' design is lightweight and easy to embed in existing methods, which shows consistent effectiveness in improving the CD and EMD scores.Comment: Accepted to ICCV 2021; typos correcte

Fine-grained Poisoning Attack to Local Differential Privacy Protocols for Mean and Variance Estimation

Although local differential privacy (LDP) protects individual users' data from inference by an untrusted data curator, recent studies show that an attacker can launch a data poisoning attack from the user side to inject carefully-crafted bogus data into the LDP protocols in order to maximally skew the final estimate by the data curator. In this work, we further advance this knowledge by proposing a new fine-grained attack, which allows the attacker to fine-tune and simultaneously manipulate mean and variance estimations that are popular analytical tasks for many real-world applications. To accomplish this goal, the attack leverages the characteristics of LDP to inject fake data into the output domain of the local LDP instance. We call our attack the output poisoning attack (OPA). We observe a security-privacy consistency where a small privacy loss enhances the security of LDP, which contradicts the known security-privacy trade-off from prior work. We further study the consistency and reveal a more holistic view of the threat landscape of data poisoning attacks on LDP. We comprehensively evaluate our attack against a baseline attack that intuitively provides false input to LDP. The experimental results show that OPA outperforms the baseline on three real-world datasets. We also propose a novel defense method that can recover the result accuracy from polluted data collection and offer insight into the secure LDP design

Association of pro-inflammatory cytokines with QCT-measured bone mineral density and its gender difference in a Chinese population — a pilot study

Introduction: The primary objective of this study was to explore the association of pro-inflammatory cytokines with quantitative computed tomography (QCT)-measured bone mineral density (BMD) and its sexual difference in a Chinese population. Material and methods: In a cross-sectional study, a total of 85 participants aged 48–85 years were recruited and classified into three groups: normal bone mass with BMD > 120 mg/cm3, osteopaenia with BMD 80–120 mg/cm3, and osteoporosis with BMD < 80 mg/cm3. ANOVA analysis and multivariable ordinal logistic regression was used to estimate the associations of interest. Results: The proportions of osteoporosis, osteopaenia, and normal BMD were 29.41% (25), 37.65% (32), and 32.94% (28), respectively. Males had the highest proportion of osteopaenia while females had osteoporosis (p < 0.01). In contrast with the null findings in males, significant statistical difference was observed in females. Compared to the normal BMD, the OR for increasing IL-6 level of decreasing BMD groups (osteoporosis and/or osteopaenia) was 9.50 (95% CI: 1.44–62.80). TNF-a and IL-17 tended to show an increased risk (OR > 1) but did not reach significance. Current OR result cannot confirm these relationships of IL-1b, and ORs of PAI-1 and MCP-1 are too close to 1 to determine the practical meaning. Conclusions: IL-6 is an obviously independent risk factor of QCT-measured osteoporosis in Chinese females. Sex hormones and fat-related factors are important confounders in the research of osteoimmunology

Shrinkage deformation of different shape of foamed concrete specimen

In construction field, the most important element is concrete. Majority of construction in Malaysia use the concrete and the improvement of concrete technology is very important. Example of concrete technology improvement is foamed concrete. Foamed concrete is additional of foaming agent in the concrete mixture to control the concrete density and the foamed concrete do not used the course aggregate. The foaming agent used to trap the air to reduce the concrete density. The strength of foamed concrete is lower than normal concrete and it is suitable to be used at the uncritical structure in the construction. The foamed agent also expose to crack effected by drying shrinkage. Some of the factors causes the drying shrinkage are investigated. Two factors of drying shrinkage investigated in this study are different density of foamed concrete and different shapes of concrete specimens. Prism sized 100mm x 100mm x 500mm, cylinder sized 150mm 0 x 300mm and 150mm cube for 1200 kg/m3 and 1600 kg/m3 density were produced throughout this experiment. The uses of prism and cylinder specimens are because it is normal shape of concrete structure with different surface expose to environmental for shrinkage observation. The cube was used for compressive strength test to prove the targeted density. The result of compressive strength test shows the increments of concrete density produced high strength of concrete. On the other hand, the increments of concrete density reduce the shrinkage value as well as the reduction of surface exposes to the environmental

A hybrid backtracking algorithm for automatic test data generation

Kao osnovno pitanje u ispitivanju softvera, automatsko generiranje podataka za ispitivanje je od najveće važnosti, što je u biti problem zadovoljavanja ograničenja, a rješava se algoritmima pretraživanja. U našem prethodnom istraživanju za rješenje ograničenja predložena je metoda grananja i ograničavanja, a elaborirane su unaprijedne metode. Zasnovan na intervalnom aritmetičkom i simboličkom izvršenju, ovaj je rad usredotočen na unatražnu metodu, a to je povezivanje unaprijednog provjeravanja i unatražnog ispitivanja usmjerenog konflikta, u cilju poboljšanja učinkovitosti unatražnog praćenja u postupku traženja. Zatvaranja varijabli se koriste kako bi se olakšalo lociranje nesuglasica koje dovode do neriješenih rezultata (dead ends). Empirijski eksperimenti dokazuju učinkovitost predložene hibridne unatražne metode i njenu primjenljivost u inženjerstvu.As a fundamental issue in software testing, automatic test data generation is of crucial importance, which is essentially a constraint satisfaction problem and solved by search algorithms. In our previous research, branch and bound was proposed as our constraint solver and the look-ahead methods were elaborated. Based on interval arithmetic and symbolic execution, this paper focuses on the look-back or backtracking method, which is the hybridization of forward checking and conflict-directed backjumping, with the aim of improving the efficiency of backtracking in the search procedure. The closures of variables are used to facilitate the localization of the conflicts which cause dead ends. Empirical experiments prove the effectiveness of the proposed hybrid backtracking method and its applicability in engineering