FakeDB: Generating Fake Synthetic Databases Gao, Chongyang; Jajodia, Sushil; Pugliese, Andrea ...
IEEE transactions on dependable and secure computing,
2024
Journal Article
Health care providers may wish to share limited information with researchers. Manufacturing companies may want to share some but not all data with regulators or partners. Since the emergence of ...generative adversarial networks (GANs), efforts have been made to generate synthetic data that preserves semantic properties on the one hand and distributions on the other hand. However, all past efforts focus on a single table at a time. We propose FakeDB, a general framework to generate synthetic data that preserves a a wide variety of semantic integrity constraints as well as a broad set of statistical properties, across an entire relational database. We compare FakeDB with natural extensions of prior work on 8 well known relational databases as well as on a synthetically generated dataset, and show that FakeDB outperforms them. We also show that FakeDB runs in reasonable amounts of time, making it a practical solution to the problem of generating synthetic data.
This article systematically explores the design space of <inline-formula> <tex-math notation="LaTeX">\beta </tex-math> </inline-formula>-(Al<inline-formula> <tex-math ...notation="LaTeX">_{\textit{x}}</tex-math> </inline-formula>Ga<inline-formula> <tex-math notation="LaTeX">_{\text{1} -\textit{x}}\text{)}_{\text{2}}</tex-math> </inline-formula>O<inline-formula> <tex-math notation="LaTeX">_{\text{3}}</tex-math> </inline-formula>/Ga<inline-formula> <tex-math notation="LaTeX">_{\text{2}}</tex-math> </inline-formula>O<inline-formula> <tex-math notation="LaTeX">_{\text{3}}</tex-math> </inline-formula> double heterojunction field-effect transistors (DH-FETs) for high-power applications using a well-calibrated TCAD setup. It primarily focuses on the impact of various intrinsic device parameters on DH-FET performance, including barrier layer thickness, delta-doped layer doping concentrations, spacer layer thicknesses, channel layer thickness, UID layer thickness, gate-to-drain contact spacing, and trap concentration. This study thoroughly examines the effect of these parameters on the on-and off-state characteristics of the device, offering valuable physical insights. For each parameter, the investigation primarily assesses its impact on on-resistance, off-state breakdown voltage, threshold voltage, and resulting power figure of merit (PFOM) as performance indicators. This study would serve as a helpful resource for designing high-power <inline-formula> <tex-math notation="LaTeX">\beta </tex-math> </inline-formula>-(Al<inline-formula> <tex-math notation="LaTeX">_{\textit{x}}</tex-math> </inline-formula>Ga<inline-formula> <tex-math notation="LaTeX">_{\text{1} -\textit{x}}\text{)}_{\text{2}}</tex-math> </inline-formula>O<inline-formula> <tex-math notation="LaTeX">_{\text{3}}</tex-math> </inline-formula>/Ga<inline-formula> <tex-math notation="LaTeX">_{\text{2}}</tex-math> </inline-formula>O<inline-formula> <tex-math notation="LaTeX">_{\text{3}}</tex-math> </inline-formula> DH-FETs and offer important guidance for the future development of Ga<inline-formula> <tex-math notation="LaTeX">_{\text{2}}</tex-math> </inline-formula>O<inline-formula> <tex-math notation="LaTeX">_{\text{3}}</tex-math> </inline-formula>-based heterostructure devices.
The log-sum function as a penalty has always been drawing widespread attention in the field of sparse problems. However, it brings a non-convex, non-smooth and non-Lipschitz optimization problem that ...is difficult to tackle. To overcome the problem, an iterative threshold algorithm for the sparse optimization problems with log-sum function is proposed in this paper. For brevity, the sparse optimization problems with log-sum function are named log-sum regularization. Firstly, by introducing an intermediate function to construct another new function, a property theorem about solution for log-sum regularization is established. Secondly, based on the above theorem, the optimal setting rules of the compromising parameters are elaborated, and an iterative log-sum threshold algorithm is proposed. Thirdly, under the situation that the compromising parameters of log-sum regularization are relatively small, it can be proven that the proposed algorithm converges to a local minimizer of log-sum regularization. Finally, a series of simulations are implemented to examine performance of the proposed algorithm, and the results exhibit that the proposed algorithm outperforms the state-of-the-art algorithms.
<inline-formula><tex-math notation="LaTeX">AC</tex-math></inline-formula> power filters play an important role in limiting the high-frequency current harmonics injected by grid-tied voltage source ...converters (VSCs). Amongst the various types of filters, <inline-formula><tex-math notation="LaTeX">LCL</tex-math></inline-formula> filters with integrated <inline-formula><tex-math notation="LaTeX">LC</tex-math></inline-formula> traps have become popular due to their ability to achieve a size reduction of the grid side inductor while demonstrating a similar current harmonic mitigation performance as a traditional <inline-formula><tex-math notation="LaTeX">LCL</tex-math></inline-formula> filter. In this article, a passively damped filter network with a partially rated <inline-formula><tex-math notation="LaTeX">LC</tex-math></inline-formula> trap (also referred to as the <inline-formula><tex-math notation="LaTeX">L\text{-}PT\text{-}L</tex-math></inline-formula> filter) is proposed and delineated. The proposed <inline-formula><tex-math notation="LaTeX">L\text{-}PT\text{-}L</tex-math></inline-formula> filter provides a <inline-formula><tex-math notation="LaTeX">-60\;\text{dB/dec}</tex-math></inline-formula> roll-off characteristics at frequencies greater than switching frequency. Additionally, it is also demonstrated that this proposed <inline-formula><tex-math notation="LaTeX">L\text{-}PT\text{-}L</tex-math></inline-formula> filter has smaller voltage ratings for two of its shunt-connected capacitor components due to the specific placement of the damping resistor. A systematic analysis of the proposed <inline-formula><tex-math notation="LaTeX">L\text{-}PT\text{-}L</tex-math></inline-formula> filter is elucidated to design and select the component parameters. Steady-state and transient experimental results captured from a grid-tied 2-Level, 3<inline-formula><tex-math notation="LaTeX">\phi</tex-math></inline-formula> VSC prototype are provided to validate the grid current harmonic filtering capability, reduced voltage ratings of the two shunt capacitors and passive damping performance of the proposed <inline-formula><tex-math notation="LaTeX">L\text{-}PT\text{-}L</tex-math></inline-formula> filter. The proposed approach can achieve 19% and 36% filter shunt branch volume reduction for low voltage (208 V, 60 Hz) and medium voltage (4.16 kV, 60 Hz) grid-tied inverter systems, respectively, compared to state-of-the-art <inline-formula><tex-math notation="LaTeX">LCL</tex-math></inline-formula> filters with integrated <inline-formula><tex-math notation="LaTeX">LC</tex-math></inline-formula> traps.
We optimized gallium nitride drift layers for high voltage and low resistance vertical electronic devices by tuning the doping concentration for a given thickness of 5 μm. The optimization procedure ...is based on an empirical mobility model in order to maximize the corresponding device´s power figure-of-merit with respect to the drift layers parameters. We demonstrate quasi-vertical gallium-nitride based avalanche and punch-through pn -diodes grown on sapphire substrates and we compare the results to the theoretical breakdown voltage values as a function of the drift region doping concentration and thickness. We report on a pn -diode with 545 V avalanche breakdown voltage and a specific resistance of 0.34 mΩ cm 2 resulting in a power figure-of-merit of 874 MW / cm 2 and a punch-through pn -diode with 920 V breakdown voltage, specific resistance of 0.57 mΩ cm 2 resulting in a power figure-of-merit of 1.48 GW / cm 2 .
Innate and adaptive immunity in teleost fish: a review Uribe, C.,Universidad Austral de Chile, Valdivia (Chile). Faculty of Veterinary Science; Folch, H.,Universidad Austral de Chile, Valdivia (Chile). Faculty of Medicine; Enriquez, R.,Universidad Austral de Chile, Valdivia (Chile). Faculty of Veterinary Science ...
Veterinární medicína,
01/2011, Letnik:
56, Številka:
10
Journal Article
Recenzirano
Odprti dostop
The aim of this review is to provide a review of the immune system in fish, including the ontogeny, mechanisms of unspecific and acquired immunity and the action of some immunomodulators. Fish rely ...on their innate immune system for an extended period of time, beginning at the early stages of embryogenesis. The components of the innate immune response are divided into physical, cellular and humoral factors and include humoral and cellular receptor molecules that are soluble in plasma and other body fluids. The lymphoid organs found in fish include the thymus, spleen and kidney. Immunoglobulins are the principal components of the immune response against pathogenic organisms. Immunomodulatory products, including nucleotides, glucans and probiotics, are increasingly used in aquaculture production. The use of these products reduces the need for therapeutic treatments, enhances the effects of vaccines and, in turn, improves the indicators of production.
The design of new tokamak machines relying on the use of high temperature superconductors (HTS) is promoting the study of HTS properties at the operating conditions required by fusion applications. ...In particular, the interest in the damage induced by neutron irradiation on RE Ba 2 Cu 3 O 7- δ ( RE BCO, RE = Y or lanthanide series), one of the most used family of HTS, has recently risen and several studies have been devoted to radiation hardness tests performed with ion irradiation or fission neutrons. In this work, the effect of neutron irradiation on YBCO films and commercial RE BCO tapes was investigated using, for the first time, neutrons produced by the D-T fusion reaction. The experiment was carried out at ENEA-Frascati Neutron Generator (FNG) where a deuteron beam is accelerated up to 300 keV and directed on a tritiated target to produce a nearly isotropic 14.1 MeV neutron field via the T(d,n)α fusion reaction. Different YBCO films deposited through metal-organic decomposition (MOD) route on single crystals (SrTiO 3 and LaAlO 3 ) and RE BCO commercial tapes, grown by pulsed laser deposition, were irradiated. Samples exposed to three fluences were compared with a maximum neutron fluence of 1.2·10 14 cm −2 . The properties of HTS materials were assessed before and after irradiation by means of different techniques. From these measurements, no significant effect on the considered properties was recognized indicating the robustness of films up to the explored irradiation fluences.
The <inline-formula> <tex-math notation="LaTeX">{q} </tex-math></inline-formula>-rung orthopair fuzzy set (<inline-formula> <tex-math notation="LaTeX">{q} </tex-math></inline-formula>-ROFS) is a ...powerful tool to deal with uncertainty and ambiguity in real life. The theoretical basis for processing the continuous <inline-formula> <tex-math notation="LaTeX">{q} </tex-math></inline-formula>-rung orthopair fuzzy information is <inline-formula> <tex-math notation="LaTeX">{q} </tex-math></inline-formula>-rung orthopair fuzzy calculus (<inline-formula> <tex-math notation="LaTeX">{q} </tex-math></inline-formula>-ROFC) and the main object is <inline-formula> <tex-math notation="LaTeX">{q} </tex-math></inline-formula>-rung orthopair fuzzy functions (<inline-formula> <tex-math notation="LaTeX">{q} </tex-math></inline-formula>-ROFFs). Recently, the authors proposed derivatives and differentials of <inline-formula> <tex-math notation="LaTeX">{q} </tex-math></inline-formula>-ROFFs in the framework of <inline-formula> <tex-math notation="LaTeX">{q} </tex-math></inline-formula>-ROFC. In this paper, we aim to further study the <inline-formula> <tex-math notation="LaTeX">{q} </tex-math></inline-formula>-rung orthopair fuzzy integral (<inline-formula> <tex-math notation="LaTeX">{q} </tex-math></inline-formula>-ROFI). It is the most important and fundamental part of the <inline-formula> <tex-math notation="LaTeX">{q} </tex-math></inline-formula>-ROFC theoretical system with direct and powerful applications. Our contribution is the indefinite and definite integrals, and bridges the fuzzy calculus theoretical gap of the nonlinear <inline-formula> <tex-math notation="LaTeX">{q} </tex-math></inline-formula>-ROFFs. In particular, we begin with the indefinite integral of <inline-formula> <tex-math notation="LaTeX">{q} </tex-math></inline-formula>-ROFFs, which can be regarded as the anti-derivatives operations of our previous work. Some of their basic properties are discussed. Next, we give the accurate concept of definite integrals of <inline-formula> <tex-math notation="LaTeX">{q} </tex-math></inline-formula>-ROFFs under additive operations, and obtain the explicit integral formula. Some properties of <inline-formula> <tex-math notation="LaTeX">{q} </tex-math></inline-formula>-ROFIs, such as comparison, algebraic operations, and mean value theorem are analyzed. Finally, we generalize the <inline-formula> <tex-math notation="LaTeX">{q} </tex-math></inline-formula>-ROFI to the case when membership and nonmembership functions are allowed to be correlated. After the theoretical results have been established, we present some numerical examples to demonstrate the rationality and effectiveness of integrating continuous <inline-formula> <tex-math notation="LaTeX">{q} </tex-math></inline-formula>-rung orthopair fuzzy data with the <inline-formula> <tex-math notation="LaTeX">{q} </tex-math></inline-formula>-ROFIs.
Metals as a cause of oxidative stress in fish: a review Sevcikova, M.,Veterinarni a Farmaceuticka Univ., Brno (Czech Republic). Fakulta Veterinarni Hygieny a Ekologie; Modra, H.,Veterinarni a Farmaceuticka Univ., Brno (Czech Republic). Fakulta Veterinarni Hygieny a Ekologie; Slaninova, A.,Veterinarni a Farmaceuticka Univ., Brno (Czech Republic). Fakulta Veterinarni Hygieny a Ekologie ...
Veterinární medicína,
01/2011, Letnik:
56, Številka:
11
Journal Article
Recenzirano
Odprti dostop
This review summarizes the current knowledge on the contribution of metals to the development of oxidative stress in fish. Metals are important inducers of oxidative stress in aquatic organisms, ...promoting formation of reactive oxygen species through two mechanisms. Redox active metals generate reactive oxygen species through redox cycling, while metals without redox potential impair antioxidant defences, especially that of thiol-containing antioxidants and enzymes. Elevated levels of reactive oxygen species lead to oxidative damage including lipid peroxidation, protein and DNA oxidation, and enzyme inactivation. Antioxidant defences include the enzyme system and low molecular weight antioxidants. Metal-binding proteins, such as ferritin, ceruloplasmin and metallothioneins, have special functions in the detoxification of toxic metals and also play a role in the metabolism and homeostasis of essential metals. Recent studies of metallothioneins as biomarkers indicate that quantitative analysis of mRNA expression of metallothionein genes can be appropriate in cases with elevated levels of metals and no evidence of oxidative damage in fish tissue. Components of the antioxidant defence are used as biochemical markers of oxidative stress. These markers may be manifested differently in the field than in results found in laboratory studies. A complex approach should be taken in field studies of metal contamination of the aquatic environment.
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