Semi-supervised MIMO Detection Using Cycle-consistent Generative Adversarial Network

In this paper, a new semi-supervised deep multiple-input multiple-output (MIMO) detection approach using a cycle-consistent generative adversarial network (CycleGAN) is proposed for communication systems without any prior knowledge of underlying channel distributions. Specifically, we propose the CycleGAN detector by constructing a bidirectional loop of two modified least squares generative adversarial networks (LS-GAN). The forward LS-GAN learns to model the transmission process, while the backward LS-GAN learns to detect the received signals. By optimizing the cycle-consistency of the transmitted and received signals through this loop, the proposed method is trained online and semi-supervisedly using both the pilots and the received payload data. As such, the demand on labelled training dataset is considerably controlled, and thus the overhead is effectively reduced. Numerical results show that the proposed CycleGAN detector achieves better performance in terms of both bit error-rate (BER) and achievable rate than existing semi-blind deep learning (DL) detection methods as well as conventional linear detectors, especially when considering signal distortion due to the nonlinearity of power amplifiers (PA) at the transmitter

El impacto de las técnicas de andamiaje basadas en aprendizaje combinado en la autoeficacia y el deseo por comunicarse

 Motivating learners to engage in effective communication is one of the fundamental concerns of language education. Accordingly, an educational context where L2 learners display a willingness to communicate (WTC) is a requirement for successful learning. A further concept that should be studied regarding WTC is students' self-efficacy from the socio-cognitive theory. Moreover, to boost the quality of learning, English as a Foreign Language (EFL) students should receive effective support, including scaffolding that motivates them to build up their knowledge in Blended Learning (BL) settings. To examine BL-based scaffolding techniques on students’ self-efficacy and WTC, this quasi-experimental design involving 232 participants were assigned to the experimental and the control groups including both intermediate and advanced learners. Subsequently, the self-efficacy questionnaire, and WTC questionnaires were distributed among them as a pretest. The statistical results of Two two-way ANCOVA tests showed that both language proficiency and the treatment type are the significant moderators of the efficacy scores. The experimental group outperformed the control group and the advanced learners outperformed the intermediate ones. In addition, the results indicated that while language proficiency did not moderate the WTC scores, the treatment type was the significant moderator of the WTC scores. Motivar al alumnado para que participen en una comunicación efectiva es una de las tareas fundamentales de educación lingüística. En consecuencia, el deseo por comunicarse (WTC) y la autoeficacia de alumnos de L2 son requisitos para un aprendizaje exitoso. Para mejorar la calidad del aprendizaje, los estudiantes de inglés como lengua extranjera necesitan un apoyo efectivo, incluido andamiaje que los motive a desarrollar sus conocimientos en contextos de aprendizaje combinado (BL). Para examinar las técnicas de andamiaje basadas en BL sobre la autoeficacia y el WTC del alumnado, este diseño cuasi experimental cuenta con 232 participantes que fueron asignados a los grupos experimentales y de control, incluyendo estudiantes de nivel intermedio y avanzado. Posteriormente, se distribuyeron como pre-test los cuestionarios de autoeficacia y los del WTC. Los resultados estadísticos de dos pruebas ANCOVA bidireccionales mostraron que tanto el dominio del idioma como el tipo de tratamiento son los moderadores significativos de las puntuaciones de eficacia. El grupo experimental superó al de control y los alumnos de nivel avanzado superaron a los de nivel intermedio. Los resultados indicaron que mientras que el dominio de lengua no moderó las puntuaciones del WTC, el tipo de tratamiento sí fue un moderador significativo. &nbsp

Electromagnetic Reinforced Carbon Fiber Composite Case and Its Electromagnetic Pulse Protection Performance

We adopt the technology of electromagnetic strengthening carbon fiber composite material to improve its electromagnetic protection ability, and use it to prepare the sample of carbon fiber composite cabinet, through the test, it has good electromagnetic pulse protection performance. Based on the carbon fiber composite structure design and electric connection design of the interlamination and gap electromagnetic enforcement. The HEMP protection performance was tested under the GB/T18039.10-2018 standard and the results showed that the HEMP shielding efficiency were above 65 dB. The carbon fiber composite cabinet had the lightweight ,high strength，HEMP shielding and anti-severe environment characteristics. The carbon fiber composite cabinet has a project value and application prospect

Numerical analyses of the flow past a short rotating cylinder

This work studies the three-dimensional flow dynamics around a rotating circular cylinder of finite length, whose axis is positioned perpendicular to the streamwise direction. Direct numerical simulations and global stability analyses are performed within a parameter range of Reynolds number $Re=DU_\infty/\nu<500$ (based on cylinder diameter $D$, uniform incoming flow velocity $U_\infty$), length-to-diameter ratio $AR=L/D\leq2$ and dimensionless rotation rate $\alpha=D\Omega/2U_\infty\leq2$ (where $\Omega$ is rotation rate). By solving Nav\-ier--Sto\-kes equations, we investigated the wake patterns and explored the phase diagrams of the lift and drag coefficients. For a cylinder with $AR=1$, we found that when the rotation effect is weak ($0\leq\alpha\lesssim0.3$), the wake pattern is similar to the unsteady wake past the non-rotating finite-length cylinder, but with a new linear unstable mode competing to dominate the saturation state of the wake. The flow becomes stable for $0.3\lesssim\alpha\lesssim0.9$ when $Re<360$. When the rotation effect is strong ($\alpha\gtrsim0.9$), new low-frequency wake patterns with stronger oscillations emerge. Furthermore, the stability analyses based on the time-averaged flows and on the steady solutions demonstrate the existence of multiple unstable modes undergoing Hopf bifurcation, greatly influenced by the rotation effect. The shapes of these global eigenmodes are presented and compared, as well as their structural sensitivity, visualising the flow region important for the disturbance development with rotation. This research contributes to our understanding of the complex bluff-body wake dynamics past this critical configuration.Comment: 35 pages, 29 figures, the version of record of this article is accepted in Journal of Fluid Mechanic

El impacto de las técnicas de andamiaje basadas en aprendizaje combinado en la autoeficacia y el deseo por comunicarse

Motivating learners to engage in effective communication is one of the fundamental concerns of language education. Accordingly, an educational context where L2 learners display a willingness to communicate (WTC) is a requirement for successful learning. A further concept that should be studied regarding WTC is students’ self-efficacy from the socio-cognitive theory. Moreover, to boost the quality of learning, English as a Foreign Language (EFL) students should receive effective support, including scaffolding that motivates them to build up their knowledge in Blended Learning (BL) settings. To examine BL-based scaffolding techniques on students’ self-efficacy and WTC, this quasi-experimental design involving 232 participants were assigned to the experimental and the control groups including both intermediate and advanced learners. Subsequently, the self-efficacy questionnaire, and WTC questionnaires were distributed among them as a pretest. The statistical results of Two two-way ANCOVA tests showed that both language proficiency and the treatment type are the significant moderators of the efficacy scores. The experimental group outperformed the control group and the advanced learners outperformed the intermediate ones. In addition, the results indicated that while language proficiency did not moderate the WTC scores, the treatment type was the significant moderator of the WTC scores.Motivar al alumnado para que participen en una comunicación efectiva es una de las tareas fundamentales de educación lingüística. En consecuencia, el deseo por comunicarse (WTC) y la autoeficacia de alumnos de L2 son requisitos para un aprendizaje exitoso. Para mejorar la calidad del aprendizaje, los estudiantes de inglés como lengua extranjera necesitan un apoyo efectivo, incluido andamiaje que los motive a desarrollar sus conocimientos en contextos de aprendizaje combinado (BL). Para examinar las técnicas de andamiaje basadas en BL sobre la autoeficacia y el WTC del alumnado, este diseño cuasi experimental cuenta con 232 participantes que fueron asignados a los grupos experimentales y de control, incluyendo estudiantes de nivel intermedio y avanzado. Posteriormente, se distribuyeron como pre-test los cuestionarios de autoeficacia y los del WTC. Los resultados estadísticos de dos pruebas ANCOVA bidireccionales mostraron que tanto el dominio del idioma como el tipo de tratamiento son los moderadores significativos de las puntuaciones de eficacia. El grupo experimental superó al de control y los alumnos de nivel avanzado superaron a los de nivel intermedio. Los resultados indicaron que mientras que el dominio de lengua no moderó las puntuaciones del WTC, el tipo de tratamiento sí fue un moderador significativo.Bureau of Philosophy and Social Science Planning of Henan Province of Chin

Numerical analysis on aerodynamic characteristics of short cylindrical terminal-sensitive bullet

The flow-induced lateral vibration phenomenon of the terminal sensitive bullets (TSB) when it is dispersed by the airborne distributor is taken as the research background. Based on the Fluent, the flow around a rotating short cylindrical TSB (L/D < 1) is simulated and analyzed varying with relative rotation velocity at high Re number (1×105 ≤ Re ≤ 3×106). The simulation results show that the flow field structure of the short cylinder with two free ends is different from the symmetry of the short cylindrical flow field with one free end, and there is no horseshoe vortex. Compared to the long cylinder with double free ends, the Cd of the short cylinder is more sensitive to the change of Re. With the increase of Re, the Cd of the short cylinder decreases, and the value is between the infinite cylinder and the sphere in the non-critical region. When the short cylinder rotates at the angular velocity ω, the top vortex bends and deforms to a ‘C’ shape on the leeward side where the fluid is accelerated. Due to the periodic disturbance of the detector, the aerodynamic coefficient of the rotating TSB is periodically vibrated. In a single cycle, the waveform of the cd shows a ‘W’ shape, and the waveform of the cl is ‘M’

Deep Learning-Based Modeling of 5G Core Control Plane for 5G Network Digital Twin

Digital twin is a key enabler to facilitate the development and implementation of new technologies in 5G and beyond networks. However, the complex structure and diverse functions of the current 5G core network, especially the control plane, lead to difficulties in building the core network of the digital twin. In this paper, we propose two novel data-driven architectures for modeling the 5G control plane and implement corresponding deep learning models, namely 5GC-Seq2Seq and 5GC-former, based on the Vanilla Seq2Seq model and Transformer decoder respectively. To train and test models, we also present a solution that allows the signaling messages to be interconverted with vectors, which can be utilized in dataset construction. The experiments are based on 5G core network signaling data collected by the Spirent C50 network tester, including various procedures related to registration, handover, PDU sessions, etc. Our results show that 5GC-Seq2Seq achieves over 99.98% F1-score (A metric to measure the accuracy of positive samples) with a relatively simple structure, while 5GC-former attains higher than 99.998% F1-score by establishing a more complex and highly parallel model, indicating that the method proposed in this paper reproduces the major functions of the core network control plane in 5G digital twin with high accuracy

Numerical analysis of underwater flow past columnar projectile with different cross-sections at high Reynolds numbers

Based on Detached Eddy Simulation (DES) technique, the flow around a columnar projectile with different cross-section shapes in the supercritical and extremely supercritical region is simulated by the Fluent. The cross-section of the projectile is regular polygon, which number of edges is 4, 6, 8, 10, 12, 24 and ∞, where ∞ means a circle. The vortex shedding pattern and flow field characteristics are analyzed at Reynolds number 2.5×105 to 2×107. Regarding circular cylinder projectile, when the flow velocity changes from 25 m/s to 200 m/s, the average drag coefficient decreases, and the St Number increases. Regarding regular polygon, when the number of edges for polygon changes from 4 to ∞ at flow velocity 50 m/s, the average drag coefficient decreases, and the St Number increases. The average lift coefficient is almost equal to zero and does not change with the flow velocity and the cross-section. The pressure coefficient Cp of 4-prism, 6-prism, 8-prism, 12-prism and 24-prism has multiple local minimum values at the polygon vertices of the cross section. According to the spectrum analysis, the vortex shedding frequency of 4-prism, 24-prism and cylindrical is single and fixed, so the projectile may cause resonance and deviates from a predetermined trajectory. But for the 6-prism and 8-prism and 12-prism, the cl and cd is multi-periodic vibration. So, considering the flow induced structural vibrations, drag, the power of shrapnel and manufacturing cost, the 8-prism are better choices for cluster warhead underwater in engineering design