Asymmetric Variations Research Articles

Comparison of ionospheric F2-layer peak height (hmF2) derived by ionosonde with IRI-2020 model over Southeast Asia

This paper presents observations of the F2-layer peak height (hmF2) compared with predictions from the IRI-2020 model over Southeast Asia. hmF2 is derived from the propagation factor at 3,000 km (M(3000)F2) using Shimazaki’s formula. M(3000)F2 data are manually scaled from three ionosonde stations: two stations in Thailand, namely Chiang Mai (CMU) and Chumphon (CPN), and one station in Indonesia, namely Kototabang (KTB). These ionosonde stations are located within the Southeast Asia equatorial ionization anomaly. The derived hmF2 from January 2009 to December 2018 is investigated for long-term variations and different solar activities (low in 2009 and high in 2015), and compared with three options of the IRI-2020 model: BSE-1979, AMTB-2013, and SHU-2015. Comparison results of the observed hmF2 at the three stations show asymmetrical variations, with hmF2 observed at Kototabang higher than at the other stations during the daytime and fluctuating at night. Results between the derived hmF2 (Observed) and predicted hmF2 (BSE-1979, AMTB-2013, SHU-2015) show similar diurnal variations and variability with solar activity. All three IRI options underestimated hmF2 during the daytime and overestimated it during nighttime, particularly around 22-02 LT. However, the BSE option shows the best prediction for all three stations, except in some times at Chiang Mai when the SHU option demonstrates the best prediction with the lowest RMSE. Therefore, we recommend the BSE-1979 option for the Southeast Asia region. Similarly, the SHU option can be selected for Chiang Mai, as it shows the best accuracy in certain years. These comparisons will contribute to improving the IRI model in the future.

The asymmetric effects of exchange rate volatility on UK–Pakistan trade flows: New evidence from nonlinear ARDL approach

Using the nonlinear autoregressive distributed lag (NARDL) method, the current study explores the effects of exchange rate variations on commodities trade between Pakistan and the United Kingdom. The current study contends that the limiting assumption of symmetry between the exchange rate and the trade flows may have hampered the empirical results, despite the fact that earlier studies primarily used the symmetric cointegration approach. From 1980 to 2020, the study examines the symmetric and asymmetries effects of exchange rate variations on 35 sectors in Pakistan that import from the UK and 35 industries that export to the UK. The findings suggest that there is evidence of a considerable influence of asymmetric exchange rate variations on trade flows in both the short and long term in over half of the importing and exporting industries that participate in trade with the UK. By highlighting the significance of taking into account asymmetry in the analysis and exposing the sector-specific effects of exchange rate changes on trade flows, the study adds to the body of current work.

Fault Handling and Localization Strategy Based on Waveform Characteristics Recognition with Coordination of Peterson Coil and Resistance Grounding Method

To address challenges in locating high-impedance grounding faults (HIGFs) and isolating fault areas in resonant grounding systems, this paper proposes a novel fault identification method based on coordinating a Peterson coil and a resistance grounding system. This method ensures power supply reliability by extinguishing the fault arc during transient faults with the Peterson coil. When a fault is determined to be permanent, the neutral point switches to a resistance grounding mode, ensuring regular distribution of zero-sequence currents in the network, thereby addressing the challenges of HIGF localization and fault area isolation. Fault calibration and nature determination rely on recognizing neutral point displacement voltage waveforms and dynamic characteristics, eliminating interference from asymmetric phase voltage variations. Fault area identification involves assessing the polarity of zero-sequence current waveforms attenuation during grounding mode switching, preventing misjudgments in grounding protection due to random initial fault angles and Peterson coil compensation states. Field experiments validate the feasibility of this fault location method and its control strategy.

Decadal Thermal Variability of the Upper Southern Ocean: Zonal Asymmetry

Abstract As the major sink of anthropogenic heat, the Southern Ocean has shown quasi-symmetric, deep-reaching warming since the mid-twentieth century. In comparison, the shorter-term heat storage pattern of the Southern Ocean is more complex and has notable impacts on regional climate and marine ecosystems. By analyzing observational datasets and climate model simulations, this study reveals that the Southern Ocean exhibits prominent decadal (>8 years) variability extending to ∼700-m depth and is characterized by out-of-phase changes in the Pacific and Atlantic–Indian Ocean sectors. Changes in the Pacific sector are larger in magnitude than those in the Atlantic–Indian Ocean sectors and dominate the total heat storage of the Southern Ocean on decadal time scales. Instead of heat uptake through surface heat fluxes, these asymmetric variations arise primarily from wind-driven heat redistribution. Pacemaker and preindustrial simulations of the Community Earth System Model version 1 (CESM1) suggest that these variations in Southern Ocean winds arise primarily from natural variability of the tropical Pacific, as represented by the interdecadal Pacific oscillation (IPO). Through atmospheric teleconnection, the positive phase of the IPO gives rise to higher-than-normal sea level pressure and anticyclonic wind anomalies in the 50°–70°S band of the Pacific sector. These winds lead to warming of 0–700 m by driving the convergence of warm water. The opposite processes, involving cyclonic winds and upper-layer divergence, occur in the Atlantic–Indian Ocean sector. These findings aid our understanding of the time-varying heat storage of the Southern Ocean and provide useful implications on initialized decadal climate prediction.

Compensating voltage waveform distortions using a practical topology of series active power filters

Addressing harmonics, voltage sags, voltage swells, and asymmetrical variations is essential to seamlessly integrate renewable energy sources, electric vehicle charging stations, and power electronics devices into electric power grids. These issues can significantly impact the sinusoidal symmetry of voltage waveforms. Series Active Power Filters (APFs) present a promising solution that can dramatically improve power quality (PQ) by effectively addressing voltage distortions. This paper first identifies several topology-related impracticalities in the existing literature on series APFs, such as using nonlinear loads or linear loads with a current source. Secondly, to understand the motivations behind these impracticalities, commonly used reference extraction methods, namely, Instantaneous Reactive Power Theory (IRPT) and Synchronous Reference Frame (SRF), are tested on a practical topology consisting of a distorted voltage source and a linear RL load. Results conducted in the MATLAB/Simulink environment show that IRPT fails to extract the reference signal under the practical topology, and SRF leads to unacceptable THDs surpassing the 5% threshold mandated by relevant standards set forth for such applications. Thirdly, the matrix pencil method (MPM), a model-based parameter estimation technique that exploits a voltage waveform's underlying exponential signal model to extract the series APF's reference voltage, is proposed. Extensive simulations showcase the superior performance of the MPM-based series APF. It successfully reduces voltage total harmonic distortion (THD) to below 1.13% across various scenarios, including situations involving harmonic-polluted voltage sources, incorporating nonlinear loads, sag and swell phenomenon, and capacitor utilization in DC link implementation.

Asymmetric variations in economic globalization, CO2 emissions, oil prices, and economic growth: a nonlinear analysis for policy empirics

Asymmetric variations in economic globalization, CO2 emissions, oil prices, and economic growth: a nonlinear analysis for policy empirics

Modeled variations of tropical cyclone genesis potential during Marine Isotope Stage 3

To advance our understanding of the responses of tropical cyclones (TCs) to abrupt climate transitions, we investigate the variation of genesis potential and the underlying mechanisms during Marine Isotope Stage 3 (MIS 3) that is characterized by frequent millennial-scale oscillations, using a set of coupled model simulations. We illustrate that genesis potential mainly increases over the eastern North Pacific and South Pacific in the storm season during MIS 3 interstadial relative to preindustrial, whereas it decreases over the western North Pacific, North Atlantic, South Indian Ocean, and Australian coast. The relative importance of each genesis factor to genesis potential change varies across oceans. During the transition from warm interstadial to cold stadial induced by freshwater injection, TC genesis potential generally decreases in the Northern Hemisphere, while increases in the Southern Hemisphere. These changes are associated with asymmetric variations of genesis factors between Northern and Southern Hemisphere, which are further tied to the adjustment of large-scale environmental factors in response to the weakened Atlantic meridional overturning circulation. Additionally, TC genesis potential exhibits a regional “overshoot” phenomenon when the freshwater injection is terminated, manifested by an increase over the eastern North Pacific and North Atlantic and a decrease over the South Pacific, compared with the initial interstadial state. Our results may help improve our knowledge on past TC behaviors and shed lights on TC response to potential abrupt climate transitions in a warmer future.

DESCRIPTION OF THE ONE FLAP TECHNIQUE FOR THE SURGICAL TREATMENT OF SYNDACTYLY

Syndactyly is a congenital defect of the fingers or toes that can cause aesthetic and functional problems. In this condition there is a defect in the separation of the parts, according to the Swanson Classification, determined between the sixth and eighth week of intrauterine life and representing approximately 20% of all hand malformations. This pathology is the second most common congenital anomaly of the hand and has an incidence of 1:2000 to 3000 live births. It is one of the most heterogeneous deformities known in the literature, with unilateral, bilateral, symmetrical and asymmetrical variations. It occurs twice as often in boys. The aim of this study is to describe a new skin flap design for the treatment of syndactyly. This is a descriptive study, as it aims to detail the surgical technique using different processes for the treatment of simple or complex, incomplete or complete syndactyly.The study maintains the principles of the digital commissure reconstruction approach, adequate skin coverage and reconstruction of the nail bed, presenting a new flap associated with polypropylene coverage, solving the disadvantages of using a skin graft, such as deformities at the recipient site and morbidity of the donor area.

Morphological study of the anatomical variations of anterior belly of digastric muscle in Brazilian cadavers.

Cases of variations in anterior belly of the digastric muscle must be carefully identified to avoid misinterpretations and assist in the correct surgical or aesthetic procedure and help in the teaching of anatomy. The aim of this study was to describe the anatomical variations of anterior belly of digastric muscle in Brazilian cadavers. Thirty-one human heads were selected, from adult cadavers (18-80 years, 29 males and 2 females). The morphology of the anterior belly of the digastric muscle was observed, identifying the possible anatomical variations that were characterised and classified according to the amount of muscle bellies, fibre direction and place of origin and insertion. The morphometric measurements were performed using a digital calliper. To analyse the data obtained, photographic documentation, anatomical description and individual morphometric description of each muscle belly were performed. The incidence of anatomical variation was obtained in percentage (%). The anatomical variation of the anterior belly of the digastric muscle was present in 6 cadavers (19.31%; 1 female and 5 male). All anatomical variations presented an accessory belly to the anterior belly. However, these accessory bellies were configured differently in the location, direction of muscle fibres and in their dimensions (length and width). The gross anatomy of the anterior belly of the digastric muscle and their variations is important to assist in surgical procedures, pathological or diagnostic function. In addition, asymmetrical variations in the submental region must be carefully identified to avoid misinterpretations.

Structure activity relationships of 5-HT2B and 5-HT2C serotonin receptor antagonists: N6, C2 and 5′-Modified (N)-methanocarba-adenosine derivatives

(N)-Methanocarba adenosine derivatives were structurally modified to target 5-HT2B serotonin receptors as antagonists, predominantly containing branched N6-alkyl groups. N6-Dicycloalkyl-methyl groups, including their asymmetric variations, as well as 2-iodo, were found to generally favor 5-HT2Rs, while only N6-dicyclohexyl-methyl derivative 35 showed weak 5-HT2AR affinity (Ki 3.6 μM). The highest 5-HT2BR affinities were Ki 11–23 nM (N6-dicyclopropyl-methyl-2-iodo 11, 2-chloro-5′-deoxy-5′-methylthio 15 and N6-((R)-cyclobuty-cyclopropyl-methyl)-2-iodo 43), and Ki 73 nM at 5-HT2CR for 36. Direct comparison of adenine ribosides and their corresponding rigid (N)-methanocarba derivatives (cf. 51 and MRS8099 45) indicated a multifold affinity enhancement with the bicyclic ring system. Compounds 43, 45 and 48 were functional 5-HT2BR (KB 2–3 nM) and 5-HT2CR (KB 79–328 nM) antagonists in a Gq-mediated calcium flux assay, with 5-HT2BR functional selectivity ranging from 45- (48) to 113-fold (43). Substantial adenosine receptor (AR) affinity (Ki, A1AR < Ki, A3AR < Ki, A2AAR) was still present in this series, suggestive of dual acting compounds: 5-HT2B antagonist and A1AR agonist, potentially useful for treating chronic conditions (fibrosis; pain). Given its affinity (17 nM) and moderate 5-HT2BR binding selectivity (32-fold vs. 5-HT2CR, 4-fold vs. A1AR), 43 (MRS7925) could potentially be useful for anti-fibrotic therapy.

An Anomalous Relationship of the Maxillary Artery with the Mandibular Nerve Branches: A Rare Case Report of Two Anatomical Variations

Abstract The maxillary artery (MA) and mandibular nerve are important structures in the infratemporal fossa (ITF) supplying large portions of the face. During a medical dissection course, two rare anatomical variations pertaining to the MA’s relationship to the mandibular nerve branches were found in three ITF. In these cases, the MA was seen to travel medial to the mandibular nerve branches. Case 1 had bilateral, asymmetric variations. On the left, the MA traveled medial to a trunk formed by the inferior alveolar and lingual nerves and lateral to the chorda tympani nerve (CTN). On the right, the MA passed lateral to the lingual and CTNs and medial to the inferior alveolar nerve. Case 2 had a unilateral variation on the left such as the variation seen on the right in Case 1. A clear understanding of MA variations has several clinical implications. This study provides a resource that may prevent complications such as bleeding, hematoma, and injury to the mandibular nerve or its branches during clinical procedures.

Scaling limits for Rudvalis card shuffles

We consider the Rudvalis card shuffle and some of its variations that were introduced by Diaconis and Saloff-Coste in [3], and we project them to some stochastic interacting particle system. For the latter, we derive the hydrodynamic limits and we study the equilibrium fluctuations. Our results show that, for these shuffles, when we consider an asymmetric variation of the Rudvalis shuffle, the hydrodynamic limit in Eulerian scale is given in terms of a transport equation with a constant that depends on the exchange rates of the system; while for symmetric and weakly asymmetric variations of this shuffle, in diffusive time scale, the evolution is given by the solution of a martingale problem.

Temperature dependent partially compensated to nearly fully compensated magnetic state in half-metallic full Heusler alloy, Mn1.2Fe1.18V0.62Al

We report experimental and theoretical studies of magnetization compensation phenomenon in quaternary Heusler alloy Mn1.2Fe1.18V0.62Al by employing dc magnetization, neutron depolarization, neutron diffraction, specific heat, electrical resistivity, and electronic structure calculation. In this ferrimagnetic alloy system with ordering temperature TC = 360 K, the asymmetric thermal variations of the site magnetic moments provide an evidence of the partially compensated magnetic state of the system down to ∼ 48 K. However, below 48 K, the system exhibits its magnetic ground state with the negligibly small ordered moment of 0.05(5) μB/f.u. at 10 K, as obtained from the neutron diffraction study. Nearly full recovery of neutron beam polarization at 4 K in the neutron depolarization study also infers a nearly fully compensated magnetization state in this Heusler alloy. Temperature dependent specific heat and resistivity measurements also corroborate with the dc magnetization study representing 48 K as a turning point at which the system reaches its ground state. The electronic structure calculations, using the SPR-KKR Green’s function approach, verify the half-metallic nature of the present system. The net magnetic moment (0.06 μB/f.u.) obtained from the theoretical calculations as well as neutron diffraction experiments (0.05 μB/f.u.) is in good agreement with the Slater-Pauling rule (0.06 μB/f.u.). This small magnetic moment of the system (Mn0.82Fe1.18)(Mn0.38V0.62)Al proclaims to be a nearly compensated ferrimagnetic system with 23.94 valence electrons. Such magnetically compensated systems with finite spin polarization could be favorable for spintronics applications.

Response Sensitivity of Centrifugal Pendulum Vibration Absorbers to Symmetry-Breaking Absorber Imperfections

This paper details an analytical investigation on free and forced vibration response sensitivity of centrifugal pendulum vibration absorbers (CPVA) to symmetry-breaking absorber imperfections. Minor variations in the absorbers’ design due to manufacturing tolerances, errors as well as operational wear and tear tend to break cyclic-symmetry and lead to asynchronous absorber oscillations, unbalanced rotor translations and thus significant vibration amplification. Therefore, an in-depth understanding on the sensitivity of CPVA's vibration response to absorber imperfections is needed to devise an improved absorber tuning strategy for robust vibration and noise reduction from realistic vehicle transmissions and drivelines. In this paper, free and forced vibration response sensitivity of generalized CPVA systems are analytically derived for absorber spacing and mass variations using the perturbation-based eigensensitivity technique in conjunction with modal superposition. The methodology applied in this study is realized through a linearized planar dynamic model, which includes both torsional and translational motions of the rotor along with oscillations of N equally-spaced baseline identical absorbers. Distinct mode distortions and degenerate mode splitting from the known baseline modal structure (with translational, rotational and absorber modes) are investigated for systems with asymmetric absorber spacing and absorber mass variations. The baseline modal structure is modified differently due to having unequal absorber masses or absorber spacing errors, and these differences are analytically derived and demonstrated. Moreover, it was identified that CPVA systems do not exhibit mode splitting with the absorber mass and spacing deviations. Response alterations and localized response patterns due to asymmetric absorber spacing and mass variations are identified and visualized through a case study. Results define a new parametric lower limit for the overtuning of absorbers to avoid localized absorber response and vibration amplification due to absorber imperfections. Additionally, the outcomes are used to locate unique excitation orders, which would help distinguish the alterations in system response due to absorber spacing and mass from each other and serve as a diagnostic tool.

Circuit Analysis and Optimization of GAA Nanowire FET Towards Low Power and High Switching

The main aim of this work is to study the effect of symmetric and asymmetric spacer length variations towards source and drain on n-channel SOI JL vertically stacked (VS) nanowire (NW) FET at 10 nm gate length (LG). Spacer length is proved to be one of the stringent metrics in deciding device performance along with width, height and aspect ratio (AR). The physical variants in this work are symmetric spacer length (LSD), source side spacer length (LS) and drain side spacer length (LD). The simulation results give the highest ION/IOFF ratio with LD variation compared to LS and LSD, whereas latter two variations have similar effect on ION/IOFF ratio. At 25 nm (2.5 × LG) of LD, the device gives appreciable ON current with the highest ION/IOFF ratio (2.19 × 108) with optimum subthreshold slope (SS) and ensures low power and high switching drivability. Moreover, it is noticed that among optimal values of LS and LD, the device ION/IOFF ratio has an improvement of 22.69% as compared to other variations. Moreover, the effect of various spacer dielectrics on optimized device is also investigated. Finally, the CMOS inverter circuit analysis is performed on the optimized symmetric and asymmetric spacer lengths.

Tidal effects on variations in organic and inorganic biogeochemical components in Changjiang (Yangtze River) Estuary and the adjacent East China Sea

Nutrients and dissolved organic carbon (DOC) including carbohydrates are essential components that drive the carbon cycle in estuarine and coastal ecosystems. The flood-ebb and spring-neap tidal variations in DOC, carbohydrate and nutrient concentrations were investigated in the Changjiang Estuary and the adjacent East China Sea. The DOC, monosaccharide (MCHO), SiO 3 2− , PO 4 3− , NO 3 − , and NO 2 − concentrations fluctuated notably with variations in tidal phases and tidal cycles. The SiO 3 2− , NO 3 − , PO 4 3− , and NO 2 − concentrations were significantly correlated with salinity at flood/ebb tides over a tidal cycle, which indicates that physical mixing might be a major factor affecting tidal variations in nutrient elements. However, there were no significant correlations between DOC, carbohydrate concentrations and salinity. Asymmetrical flood-ebb tidal variations in DOC, carbohydrate and nutrient concentrations were observed, which might result from variations in Changjiang freshwater input due to asymmetrical flood-ebb tidal duration time and velocities in the Changjiang Estuary. There were statistically significant flood-ebb tidal differences in SiO 3 2− , NO 3 − , and NO 2 − concentrations during spring tide in the Changjiang Estuary and neap tide in the East China Sea. DOC and carbohydrate concentrations showed more complex tidal behaviors due to their specific physical and biological characteristics. Principal component analysis indicated that physical mixing driven by tidal forces was an important factor influencing tidal variations in these organic and inorganic components. Other physical and biological processes, such as absorption and microbial degradation, might have also contributed to the tidal variations in these components. Tidal forcing plays a considerable role in controlling temporal variations in organic and inorganic nutrients and should be considered when sampling in estuarine systems and estimate the fluxes of these components. • Asymmetrical flood-ebb tidal variations in nutrients and DOC were observed. • PO 4 3− and NO 2 − showed significant variations between different types of tidal cycles. • DOC showed nonconservative tidal behaviors in the Changjiang Estuary. • Changjiang freshwater input was a main factor affecting tidal variation in nutrients.

A SOGI-PLL-Based Feedback-Feedforward Control System for Three-Phase Dynamic Voltage Restorer in the Distribution Grid

Background and Objectives: Due to the increased sensitive loads, improving power quality in distribution grids by custom power tools is one of the important fields of electrical engineering. This paper proposes a new kind of three-phase three-wire dynamic voltage restorer (without including storage sources or DC link) and also its control method.Methods: The proposed structure includes an AC/AC converter, low-pass filters at the input and output sides, and three-phase injection transformers. The control system is based on the combination of feedback and feedforward control that its advantages are high speed, good response quality, and very simple implementation. To overcome the harmonics raised from AC/AC converter switching on the main line, a SOGI-PLL has been used. Also, SOGI-PLL operates independently on each phase so that the asymmetric voltage variations can be identified.Results: The proposed control method is capable to compensate the power quality problems such as voltage sag, swell, and harmonics in balanced and unbalanced conditions. The detailed modelling and design of the proposed controller are verified through computer simulations and experimental results under different operating conditions. Simulation and experimental results show that the proposed control strategy can compensate the power quality events as close as possible to the desired values under different operation modes.Conclusion: In this paper, a three-phase three-wire dynamic voltage restorer (DVR) was assessed using direct AC/AC converters without a supply source and DC link. A control system based on combined feedback and feedforward control (CFBFFC) and SOGI-PLL has been proposed for the DVR. The simulation results on a three-phase 20kV system as well as the experimental results obtained from a single-phase 220V system verified the performance of the DVR and the control system. It was shown that this structure can compensate for 0.5pu voltage sag, above 1pu voltage swell, and all kinds of harmonic faults.

Robust mixed H2/H∞ fuzzy tracking control of photovoltaic system subject to asymmetric actuator saturation

This paper focuses on mixed [Formula: see text] fuzzy maximum power point tracking (MPPT) of photovoltaic (PV) system under asymmetric saturation and variations in climatic conditions. To maximize the power from the PV panel array, the DC–DC boost converter is controlled by its duty ratio which is practically saturated between 0 and 1. MPPT based on conventional control presents the problems of oscillations around maximum power point (MPP) and divergence under rapid climatic changes. In order to attenuate the effect of atmospheric condition variation and take into account asymmetric saturation of the duty ratio, we propose a novel robust saturated controller based on both [Formula: see text] performances and Takagi-Sugeno (T-S) representation of PV-boost nonlinear system. Within this approach, the nonlinear PV-boost system and its reference are first described by T-S fuzzy models. Second, the saturation effect is represented by a polytopic model. Then, a fuzzy integral state feedback controller is designed to achieve stable MPPT control. Based on Lyapunov function, the mixed [Formula: see text] stabilization conditions are derived in terms of linear matrix inequalities (LMIs). The optimization of the attraction domain of closed-loop system is solved as a convex optimization problem in LMI terms. Finally, the efficiency of the proposed controller under irradiance and temperature variations is demonstrated through the simulation results. The comparison with some existing controllers shows an improvement of MPPT control performance in terms of power extraction.

Spotting Deepfakes and Face Manipulations by Fusing Features from Multi-Stream CNNs Models

Deepfake is one of the applications that is deemed harmful. Deepfakes are a sort of image or video manipulation in which a person’s image is changed or swapped with that of another person’s face using artificial neural networks. Deepfake manipulations may be done with a variety of techniques and applications. A quintessential countermeasure against deepfake or face manipulation is deepfake detection method. Most of the existing detection methods perform well under symmetric data distributions, but are still not robust to asymmetric datasets variations and novel deepfake/manipulation types. In this paper, for the identification of fake faces in videos, a new multistream deep learning algorithm is developed, where three streams are merged at the feature level using the fusion layer. After the fusion layer, the fully connected, Softmax, and classification layers are used to classify the data. The pre-trained VGG16 model is adopted for transferred CNN1stream. In transfer learning, the weights of the pre-trained CNN model are further used for training the new classification problem. In the second stream (transferred CNN2), the pre-trained VGG19 model is used. Whereas, in the third stream, the pre-trained ResNet18 model is considered. In this paper, a new large-scale dataset (i.e., World Politicians Deepfake Dataset (WPDD)) is introduced to improve deepfake detection systems. The dataset was created by downloading videos of 20 different politicians from YouTube. Over 320,000 frames were retrieved after dividing the downloaded movie into little sections and extracting the frames. Finally, various manipulations were performed to these frames, resulting in seven separate manipulation classes for men and women. In the experiments, three fake face detection scenarios are investigated. First, fake and real face discrimination is studied. Second, seven face manipulations are performed, including age, beard, face swap, glasses, hair color, hairstyle, smiling, and genuine face discrimination. Third, performance of deepfake detection system under novel type of face manipulation is analyzed. The proposed strategy outperforms the prior existing methods. The calculated performance metrics are over 99%.

Trade liberalization, export quality, and three dimensions of wage inequality*

AbstractIn the context of quality content of export baskets becoming the most important determinant of export growth for developing countries, we show that reduction in tariff on final import goods asymmetrically affects the quality of skill‐based export goods that differ with respect to the relative skill intensity of their higher‐quality varieties. This offers a plausible explanation for asymmetric quality variations across product groups observed for Brazil and India since the 1980s. On the contrary, tariff‐reduction‐induced quality variations, regardless of their asymmetry, accentuate wage inequality in all dimensions by depressing the informal unskilled wage through displacement of unskilled workers from the formal sector and the consequent informalization of the economy. This suggests that tariff reductions accentuating wage inequality, as shown in the existing literature, may be underestimated if induced variations in the quality of export goods are unaccounted for. A quality‐content production subsidy or a subsidy targeting the use of skilled labor, given to producers of the export good whose quality is downgraded as a consequence of tariff reduction, can be used as a concurrent policy to mitigate such effect. The wage inequality will also decline to some extent following such subsidies. A proportional factor income tax may be a quality‐neutral way to finance the subsidies.