105 research outputs found
Identityâbased Schemes for a Secured Big Data and Cloud ICT Framework in Smart Grid System
Smart grid is an intelligent cyber physical system (CPS). The CPS generates a massive amount of data for efficient grid operation. In this paper, a big dataâdriven, cloudâbased information and communication technology (ICT) framework for smart grid CPS is proposed. The proposed ICT framework deploys hybrid cloud servers to enhance scalability and reliability of smart grid communication infrastructure. Because the data in the ICT framework contains much privacy of customers and important data for automated controlling, the security of data transmission must be ensured. In order to secure the communications over the Internet in the system, identityâbased schemes are proposed especially because of their advantage in key management. Specifically, an identityâbased signcryption (IBSC) scheme is proposed to provide confidentiality, nonârepudiation, and data integrity. For practical purposes, an identityâbased signature scheme is relaxed from the proposed IBSC to provide nonârepudiation only. Moreover, identityâbased schemes are also proposed to achieve signature delegation within the ICT framework. Security of the proposed IBSC scheme is rigorously analyzed in this work. Efficiency of the proposed IBSC scheme is demonstrated with an implementation using modified Weil pairing over an elliptic curve
A Security Protocol for Advanced Metering Infrastructure in Smart Grid
In this paper, we propose a security protocol for advanced metering infrastructure (AMI) in smart grid. AMI is one of the important components in smart grid and it suffers from various vulnerabilities due to its uniqueness compared with wired networks and traditional wireless mesh networks. Our proposed security protocol for AMI includes initial authentication, secure uplink data aggregation/recovery, and secure downlink data transmission. Compared with existing researches in such area, our proposed security protocol let the customers be treated fairly, the privacy of customers be protected, and the control messages from the service provider be delivered safely and timely
A Security Protocol for Advanced Metering Infrastructure in Smart Grid
In this paper, we propose a security protocol for advanced metering infrastructure (AMI) in smart grid. AMI is one of the important components in smart grid and it suffers from various vulnerabilities due to its uniqueness compared with wired networks and traditional wireless mesh networks. Our proposed security protocol for AMI includes initial authentication, secure uplink data aggregation/recovery, and secure downlink data transmission. Compared with existing researches in such area, our proposed security protocol let the customers be treated fairly, the privacy of customers be protected, and the control messages from the service provider be delivered safely and timely
Modelling particle collisions in moderately dense curtain impacted by an incident shock wave
The interactions between an incident shock and moderately dense particle
curtain are simulated with the Eulerian-Lagrangian method. A customized solver
based on OpenFOAM is extended with an improved drag model and collision model,
and then validated against two benchmark experiments. In this work, parametric
studies are performed considering different particle sizes, volume fractions,
and curtain thicknesses. It is found that smaller particle size and larger
volume fractions lead to stronger reflected shock and weaker transmitted shock.
Different expansion stages of the curtain fronts are also studied in detail.
Attention is paid to the particle collision effects on the curtain evolution
behaviours. According to our results, for the mono-dispersed particle curtain,
the collision effects on curtain front behaviors are small, even when the
initial particle volume fraction is as high as 20%. This is due to the positive
velocity gradient across the curtain after the shock wave passage, leading to
faster motion of downstream particles than the upstream ones and hence no
collision occurs. For the bi-dispersed particle curtain, the collision effects
become important in the mixing region of different-size particles. Collisions
decelerate small particles while accelerate large ones and cause velocity
scattering. Moreover, increasing the bi-dispersed curtain thickness leads to
multiple collision force peaks due to the local particle accumulations, which
is the result of the delayed separation of different particle groups. Our
results indicate that the collision model may be unnecessary to predict curtain
fronts in mono-dispersed particles, but in bi-dispersed particles, the
collision effects are important and therefore must be modelled
Dynamic coupling modelling and application case analysis of high-slip motors and pumping units
To solve the issues and difficulties in the high-coupling modelling of beam pumping units and high-slip motors, external characteristic experiments of high-slip motors were performed where the external database and characteristic correlation equations of the motors were obtained through data regression analysis. Based on the analysis of the kinematics, dynamics and driving characteristics of the beam pumping unit, a fully coupled mathematical model of a motor, pumping unit, sucker rod and oil pump was established. The differential pumping equation system of the pumping unit used a cyclic iteration method to solve the problem of high coupling among the motor, pumping unit, sucker rod and the pumping pump. The model was verified by experimental data of field l pumping wells. Theoretical calculations and experimental tests showed that the soft characteristic of the high-slip motor can reduce the peak suspension load of the sucker rod, peak net torque of the gearbox and peak power of the motor. In addition, the results show that the soft characteristic can also decrease the high-frequency fluctuation of the motor power curve and the torque curve of the gearbox. The highslip motor can improve the smoothness and safety of the pumping well system
Review of variable speed drive technology in beam pumping units for energy-saving
Beam pumping units have been widely used in oilfields worldwide due to its simple structure, strong field adaptability, and convenient maintenance. Different energy-saving technologies have also been broadly applied in various beam pumping units. Among these energy-saving methods, the variable speed drive is one of the most acceptable techniques in the oil and gas industry. In this paper, the energy-saving technology of variable speed drives is discussed in detail for beam pumping units pointing out existing difficulties and current research status in kinematics. Three application examples of a variable speed drive in Daqing oilfield, the largest oilfield in China, is shown
MM-TTS: Multi-modal Prompt based Style Transfer for Expressive Text-to-Speech Synthesis
The style transfer task in Text-to-Speech refers to the process of
transferring style information into text content to generate corresponding
speech with a specific style. However, most existing style transfer approaches
are either based on fixed emotional labels or reference speech clips, which
cannot achieve flexible style transfer. Recently, some methods have adopted
text descriptions to guide style transfer. In this paper, we propose a more
flexible multi-modal and style controllable TTS framework named MM-TTS. It can
utilize any modality as the prompt in unified multi-modal prompt space,
including reference speech, emotional facial images, and text descriptions, to
control the style of the generated speech in a system. The challenges of
modeling such a multi-modal style controllable TTS mainly lie in two
aspects:1)aligning the multi-modal information into a unified style space to
enable the input of arbitrary modality as the style prompt in a single system,
and 2)efficiently transferring the unified style representation into the given
text content, thereby empowering the ability to generate prompt style-related
voice. To address these problems, we propose an aligned multi-modal prompt
encoder that embeds different modalities into a unified style space, supporting
style transfer for different modalities. Additionally, we present a new
adaptive style transfer method named Style Adaptive Convolutions to achieve a
better style representation. Furthermore, we design a Rectified Flow based
Refiner to solve the problem of over-smoothing Mel-spectrogram and generate
audio of higher fidelity. Since there is no public dataset for multi-modal TTS,
we construct a dataset named MEAD-TTS, which is related to the field of
expressive talking head. Our experiments on the MEAD-TTS dataset and
out-of-domain datasets demonstrate that MM-TTS can achieve satisfactory results
based on multi-modal prompts.Comment: Accepted at AAAI202
Annexin A7 and Its Related Protein Suppressor of Death Domains Regulates Migration and Proliferation of Hca-P Cells
Objective: This study was to investigate whether annexin A7 (AnnexinA7, ANXA7) and its co-related protein tumor celldeath domain silencer [suppressor of death domains (SODD)] regulates the migratory phenotype of liver cancer cells.Materials and Methods: In this experimental study, expression of ANXA7 in Hca-P cells, PANXA7 downregulatedcells and PANXA7 unrelated sequence cells was detected by real-time quantitative polymerase chainreaction (PCR) at mRNA level and western blotting at protein level. Transwell migration and invasion assayswere performed to determine the migratory phenotype.Results: After inhibition of ANXA7 expression, expression of SODD protein was also significantly decreased (P<0.05).Transwell cell transfer experiments showed that number of tumor cells that penetrated into the cell membrane wassignificantly reduced after ANXA7 silencing (P<0.05). Transwell cell invasion assay showed that number of tumorcells penetrating into Matrigel was significantly reduced after ANXA7 down-regulation (P<0.05). The CCK8 assay wasmeasured at 0, 24 and 48 hours, and proliferation rate of PANXA7 lower weir cells was slower than that of Hca-P cellsand PANXA7 non-related sequence cells (P<0.05).Conclusion: SODD expression was decreased with the down-regulation of ANXA7. Down-regulating ANXA7 in Hca-Pcells decreased proliferation, migration and invasion of tumor cells
Impaired night-time mobility in patients with Parkinsonâs disease: a systematic review
Impaired bed mobility (IBM) is a symptom characteristic of patients having difficulty intentionally moving their bodies during nighttime sleep. IBM is one of the most common nocturnal symptoms of Parkinsonâs disease (PD) and may lead to extreme pain and even death; it also increases the burden on the patientsâ caregivers. In this systematic review, we included 19 studies involving a total of 1,407 patients with PD to observe the causes, assessment methods, and treatment options for IBM. We conclude that the extent of IBM is positively correlated with the severity of symptoms such as disease duration, dyskinesia and decreased sleep quality in patients with PD, and the evidence implies that IBM may be able to serve as a prodromal feature in the development of PD. IBM probably results from low nocturnal dopamine concentrations, reduced function of the spinal tract, torque problems in the muscles, and aging. Therefore, treatment is mostly based on continuously increasing the patientâs nocturnal dopamine concentration, while deep brain stimulation (DBS) also has a mitigating effect on IBM. Both scales and sensors are commonly used to measure the severity of IBM, the wearable device monitoring and scales being updated makes measurements easier and more accurate. The future of the advancement in this field lies in the use of more family-oriented devices (such as smart phones or watches and bracelets, etc.) to monitor IBMâs symptoms and select the appropriate therapeutic treatment according to the severity of the symptoms to relieve patientsâ suffering
Intraocular pressure effect of intravitreal conbercept injection for retinopathy of prematurity
Purpose: Intravitreal injection of conbercept (IVC) is a novel anti-vascular endothelial growth factor (anti-VEGF) treatment for retinopathy of prematurity (ROP). This study aimed to assess the intraocular pressure (IOP) effect of IVC.Methods: All IVC surgeries were performed in the Department of Ophthalmology, Guangdong Women and Children Hospital, from January 2021 to May 2021. In this study, 30 eyes of 15 infants who received intravitreal injections of conbercept at a dose of 0.25 mg/0.025 mL were included. The IOP of all participants was measured prior to administering the injection and subsequently at 2 min, 1 h, 1 day, and 1 week thereafter.Results: We included 30 eyes (10 boys and 5 girls) with ROP. For the male group, the mean birth weight, mean gestational age at birth, and the mean time of postmenstrual age (PMA) at IVC treatment were 1,174.0 ± 446.0 g, 28.4 ± 3.0 weeks, and 37.1 ± 1.6 weeks, respectively; for the female group, they were 1,108 ± 285.5 g, 28.2 ± 2.5 weeks, and 36.8 ± 2.1 weeks, respectively. For the male group, the IOP at baseline, 2 min, 1 h, 1 day, and 1 week after IVC were 12.4 ± 1.5 mmHg, 49.0 ± 3.1 mmHg, 26.3 ± 2.5 mmHg, 13.4 ± 2.2 mmHg, and 11.6 ± 1.7 mmHg, respectively; for the female group, they were 10.7 ± 2.0 mmHg, 47.3 ± 3.2 mmHg, 26.4 ± 3.2 mmHg, 10.7 ± 1.8 mmHg, and 10.2 ± 1.8 mmHg, respectively. In both groups, the IOP immediately (2 min) after the operation was significantly higher than that at any other time point (p < 0.01). IOP values returned to the preoperative baseline level on the first day after surgery, with no significant difference compared with that before injection (p > 0.05). IOP continued to be maintained at the preoperative baseline level on the first week after surgery, with no significant difference compared with that before surgery (p > 0.05).Conclusion: Infants with ROP who received IVC experienced a sharp increase in the IOP immediately after injection, which decreased to below 30 mmHg after 1 h and maintain that level for 1 week or longer
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