Partial differential equations (PDEs) serve as the cornerstone of mathematical physics. In recent years, Physics-Informed Neural Networks (PINNs) have significantly reduced the dependence on large datasets by embedding physical laws directly into the training of neural networks. However, when dealing with complex problems, the accuracy of PINNs still has room for improvement. To address this issue, we introduce the Over-PINNs framework, which leverages automatic differentiation (AD) to generate higher-order auxiliary equations that impose additional physical constraints. These equations are incorporated as extra loss terms in the training process, effectively enhancing the model's ability to capture physical information through an "overdetermined" approach. Numerical results illustrate that this method exhibits strong versatility in solving various types of PDEs. It achieves a significant improvement in solution accuracy without incurring substantial additional computational costs.
A parameter identification method which merges experimentally monitored signals and physics-based simulation data is proposed, targeting the identification tasks in shaft seals which are challenging due to the high-dimensional parameter space. Features were extracted from the monitored acoustic emission signals following a proposed cross-timescale analysis routine, and the simulation data were augmented using Kriging surrogate model to obtain a dataset with stratified fidelity. Then, a transferable architecture of convolutional neural network modified for periodical data was proposed, with which part of the parameters trained by simulation data were reserved when training model using acoustic emission data acquired in experiments. Cross validation shows that transfer learning can effectively improve the performance, provided data augmentation and proper transfer mode. In conclusion, the study provides an effective parameter identification method which merges the simulation data which carry the physical knowledge and the experiment data which carry directly monitored results.
The monitoring of abnormal states of dry gas seals is a critical but challenging task for equipment reliability. This paper proposes an end-face groove structure oriented to the condition monitoring of dry gas seals. In addition to hydrodynamic grooves on the end face of the mating ring, seven special monitoring grooves are manufactured on the other side of the dual end face. These monitoring grooves can induce characteristics of end-face contact that can be detected by an acoustic emission sensor, where the primary characteristic is the seven times the motor speed frequency(7-TMSF). Simulations are conducted using a dynamic model to help establish the monitoring method.
A modified diffuse domain-lattice Boltzmann model for heat transfer problems with the Dirichlet boundary condition in complex geometries is proposed in this paper. In this model, the complex computational domain is embedded into a lager and regular domain. The level set function is used to identify the complex interior boundary. A diffuse domain formulation for the temperature field is established on the larger domain. To remove the ill-conditioned property of the original diffuse domain equation, we develop a new regularization technique to tackle this issue. We also give a lattice Boltzmann scheme to solve the regularized diffuse domain equation. The numerical accuracy of the present model is investigated by the steady state and time-decay problems. Then the natural convection problems in a square enclosure with a heated circular cylinder and in a horizontal concentric annulus are simulated. Both the uniform and non-uniform wall temperature cases are considered. Moreover, an alternative method to calculate the average Nusselt number on the complex boundary is employed. The predicted results show a good agreement with the previous solutions in previous literatures. The effect of non-uniform wall temperature on the heat transfer rate is also investigated.
Pilot reuse (PR) in each cell has been proposed to reduce the pilot overhead and improve the throughput of massive multiple-input multiple-output systems. Since PR can introduce interference into channel estimation, several pilot scheduling schemes have been developed to alleviate this problem. However, current schemes have high computational complexity. In this paper, we try to design a low-complexity PR scheme making full use of the channel angle-of- arrival (AOA) information. First we point out that the pilot interference may remain severe even though the AOAs of users reusing pilots are non- overlapping, then an additional criterion is proposed to guide PR. We also develop a method based on the spatial filtering to estimate the channel AOA cosine interval, and develop a PR scheme with the criterion. Simulation results show that the pilot interference can be mainly confined to be a very low level under the proposed PR scheme, and the system throughput can be greatly improved compared to the conventional massive MIMO system.
In this paper, a sectorized multi-cell massive multiple-input multiple-output (MIMO) system is considered with a spatially correlated channel model. Since sum-throughput per cell is an important index for evaluating a multi-cell system, we derive the ergodic achievable uplink sum-throughput per cell of the sectorized system and give the deterministic approximation of it based on the large random matrix theory. Numerical results indicate that sum-throughput per cell can be greatly increased compared to the conventional multi-cell massive MIMO system, which validates the effectiveness of the sectorized system. Moreover, it can be seen that the deterministic approximation is consistent with the result of Monte-Carlo simulation.
Device-to-Device (D2D) underlay cellular communication has been recently considered as a popular paradigm to enhance system performance. In this paper, we study a power-allocation problem to maximize the system sum-rate while giving priority to cellular users (CUs), assuming that only large- scale fading information is known at the base station. Specifically, we give priority to CUs by introducing outage probability constraints. Further, we adopt the geometric programming technique to solve the optimal power-allocation problem. Numerical results show that the proposed outage- constrained power allocation scheme not only provides more reliable cellular communication but also improves the system sum-rate performance.
In uplink device-to-device (D2D) underlay cellular systems, massive multiple-input multiple-output (MIMO) seems promising as the large antenna array at the base station (BS) can nearly null the D2D-to-cellular interference. But the channel state information from all the users including D2D users to the BS is required to obtain the advantage. For the orthogonal channel training scheme, the pilot overhead becomes large with the number of users increasing, and constitutes a bottleneck for improvement of the system sum-throughput. In this paper, we propose pilot reuse (PR) for D2D underlay massive MIMO systems to reduce the pilot overhead and increase the system sum-throughput. Further, we develop a pilot scheduling algorithm under the criterion of minimizing the sum of mean square errors of channel estimation. Numerical results show that the proposed PR scheme can greatly increase the system sum-throughput at the price of slight degradation of cellular performance, compared to the conventional massive MIMO system.
This paper investigates the impact of multi-antenna spacing at each terminal on the performance of the distributed antenna system in outdoor environments in higher frequency bands (above 6 GHz), where the line-of-sight propagation plays the most important role. We choose the channel matrix condition number as the evaluation criterion of performance and focus on it in simulations and practical tests. The simulation results show that the larger the antenna spacing (normalized to the carrier wavelength) is, the more drastically the channel condition number varies with the terminal moving. It is also found that a small channel condition number can be obtained even when multiple antennas of a terminal are located very close to each other. In addition, outdoor experimental results are provided to support our analysis. These contribute to the design of terminals' multi antenna.
In massive MIMO systems, the number of terminals simultaneously served by the base station (BS) can be up to half of the coherence time in symbols when the cell sum-throughput is pursued. In this case, the conventional downlink training scheme for multiuser MIMO systems, in which the BS beamforms orthogonal pilot sequences of length no less than the number of terminals, is inefficient. We assume ZF beamforming is used and it is found that the desired signal can be much stronger than the interference at each terminal. Therefore, we propose to let the BS beamform non-orthogonal pilot sequences, which are of shorter length than that with the conventional scheme. We then derive a lower bound on the achievable rate and find that our proposed scheme is preferable from numerical results. Furthermore, we note that our proposed scheme performs similarly as the scheme with which each terminal uses the expected value of the effective channel gain to decode the received signal, but our proposed scheme is simpler when implementation is considered.
The Daya Bay Reactor Neutrino Experiment was designed to achieve a sensitivity on the value of sin22θ13 to better than 0.01 at 90% CL. The experiment consists of eight antineutrino detectors installed underground at different baselines from six nuclear reactors. With data collected with six antineutrino detectors for 55 days, Daya Bay announced the discovery of a non-zero value for sin22θ13 with a significance of 5.2 standard deviations in March 2012. The most recent analysis with 139 days of data acquired in a six-detector configuration yields sin22θ13=0.089±0.010(stat.)±0.005(syst.), which is the most precise measurement of sin22θ13 to date.
The Daya Bay experiment consists of functionally identical antineutrino detectors immersed in pools of ultrapure water in three well-separated underground experimental halls near two nuclear reactor complexes. These pools serve both as shields against natural, low-energy radiation, and as water Cherenkov detectors that efficiently detect cosmic muons using arrays of photomultiplier tubes. Each pool is covered by a plane of resistive plate chambers as an additional means of detecting muons. Design, construction, operation, and performance of these muon detectors are described.
In massive multiple-input multiple-output time division duplex systems, the number of users simultaneously served by the base station (BS) is heavily limited if uplink orthogonal pilots are used. This difficulty can be alleviated by introducing non-orthogonal pilots through exploiting second-order channel statistics and sectorization. In this paper, we consider the large uniform linear array and propose a novel sectorization method with low complexity, in which multiple users per sector can be simultaneously served as if there were multiple BS antennas with identical directional characteristics in each sector. Numerical results show that the sum-throughput can be greatly increased compared to the typical massive MIMO architecture.
P. Naik, J. Rademacker, D. M. Asner, K. W. Edwards, J. Reed, A. N. Robichaud, G. Tatishvili, R. A. Briere, H. Vogel, P. U. E. Onyisi, J. L. Rosner, J. P. Alexander, D. G. Cassel, J. E. Duboscq, R. Ehrlich, L. Fields, R. S. Galik, L. Gibbons, R. Gray, S. W. Gray, D. L. Hartill, B. K. Heltsley, D. Hertz, J. M. Hunt, J. Kandaswamy, D. L. Kreinick, V. E. Kuznetsov, J. Ledoux, H. MahlkeKruger, D. Mohapatra, J. R. Patterson, D. Peterson, D. Riley, A. Ryd, A. J. Sadoff, X. Shi, S. Stroiney, W. M. Sun, T. Wilksen, S. B. Athar, J. Yelton, P. Rubin, S. Mehrabyan, N. Lowrey, M. Selen, E. J. White, J. Wiss, R. E. Mitchell, M. R. Shepherd, D. Besson, T. K. Pedlar, D. Cronin-Hennessy, K. Y. Gao, J. Hietala, Y. Kubota, T. Klein, R. Poling, A. W. Scott, P. Zweber, S. Dobbs, Z. Metreveli, K. K. Seth, B. J. Y. Tan, A. Tomaradze, J. Libby, L. Martin, A. Powell, G. Wilkinson, H. Mendez, J. Y. Ge, D. H. Miller, V. Pavlunin, B. Sanghi, I. P. J. Shipsey, B. Xin, G. S. Adams, D. Hu, B. Moziak, J. Napolitano, Q. He, J. Insler, H. Muramatsu, C. S. Park, E. H. Thorndike, F. Yang, M. Artuso, S. Blusk, S. Khalil, J. Li, R. Mountain, K. Randrianarivony, N. Sultana, T. Skwarnicki, S. Stone, J. C. Wang, L. M. Zhang, G. Bonvicini, D. Cinabro, M. Dubrovin, A. Lincoln, and K. M. Ecklund
Z. Li, A. Lopez, H. Mendez, J. Ramirez, G. S. Huang, D. H. Miller, V. Pavlunin, B. Sanghi, E. I. Shibata, I. P. J. Shipsey, G. S. Adams, M. Chasse, M. Cravey, J. P. Cummings, I. Danko, J. Napolitano, Q. He, H. Muramatsu, C. S. Park, W. Park, E. H. Thorndike, T. E. Coan, Y. S. Gao, F. Liu, M. Artuso, C. Boulahouache, S. Blusk, J. Butt, E. Dambasuren, O. Dorjkhaidav, J. Li, N. Menaa, R. Mountain, R. Nandakumar, R. Redjimi, R. Sia, T. Skwarnicki, S. Stone, J. C. Wang, K. Zhang, S. E. Csorna, G. Bonvicini, D. Cinabro, M. Dubrovin, R. A. Briere, G. P. Chen, J. Chen, T. Ferguson, G. Tatishvili, H. Vogel, M. E. Watkins, J. L. Rosner, N. E. Adam, J. P. Alexander, K. Berkelman, D. G. Cassel, V. Crede, J. E. Duboscq, K. M. Ecklund, R. Ehrlich, L. Fields, R. S. Galik, L. Gibbons, B. Gittelman, R. Gray, S. W. Gray, D. L. Hartill, B. K. Heltsley, D. Hertz, L. Hsu, C. D. Jones, J. Kandaswamy, D. L. Kreinick, V. E. Kuznetsov, H. Mahlke-Kruger, T. O. Meyer, P. U. E. Onyisi, J. R. Patterson, D. Peterson, E. A. Phillips, J. Pivarski, D. Riley, A. Ryd, A. J. Sadoff, H. Schwarthoff, M. R. Shepherd, S. Stroiney, W. M. Sun, D. Urner, T. Wilksen, M. Weinberger, S. B. Athar, P. Avery, L. Breva-Newell, R. Patel, V. Potlia, H. Stoeck, J. Yelton, P. Rubin, C. Cawlfield, B. I. Eisenstein, G. D. Gollin, I. Karliner, D. Kim, N. Lowrey, P. Naik, C. Sedlack, M. Selen, J. Williams, J. Wiss, K. W. Edwards, D. Besson, T. K. Pedlar, D. Cronin-Hennessy, K. Y. Gao, D. T. Gong, Y. Kubota, T. Klein, B. W. Lang, S. Z. Li, R. Poling, A. W. Scott, A. Smith, S. Dobbs, Z. Metreveli, K. K. Seth, A. Tomaradze, P. Zweber, J. Ernst, A. H. Mahmood, H. Severini, D. M. Asner, S. A. Dytman, W. Love, S. Mehrabyan, J. A. Mueller, and V. Savinov
P. Rubin, C. Cawlfield, B. I. Eisenstein, I. Karliner, D. Kim, N. Lowrey, P. Naik, C. Sedlack, M. Selen, E. J. White, J. Wiss, M. R. Shepherd, D. Besson, T. K. Pedlar, D. Cronin-Hennessy, K. Y. Gao, D. T. Gong, J. Hietala, Y. Kubota, T. Klein, B. W. Lang, R. Poling, A. W. Scott, A. Smith, S. Dobbs, Z. Metreveli, K. K. Seth, A. Tomaradze, P. Zweber, J. Ernst, H. Severini, S. A. Dytman, W. Love, V. Savinov, O. Aquines, Z. Li, A. Lopez, S. Mehrabyan, H. Mendez, J. Ramirez, G. S. Huang, D. H. Miller, V. Pavlunin, B. Sanghi, I. P. J. Shipsey, B. Xin, G. S. Adams, M. Anderson, J. P. Cummings, I. Danko, J. Napolitano, Q. He, J. Insler, H. Muramatsu, C. S. Park, E. H. Thorndike, T. E. Coan, Y. S. Gao, F. Liu, M. Artuso, S. Blusk, J. Butt, J. Li, N. Menaa, R. Mountain, S. Nisar, K. Randrianarivony, R. Redjimi, R. Sia, T. Skwarnicki, S. Stone, J. C. Wang, K. Zhang, S. E. Csorna, G. Bonvicini, D. Cinabro, M. Dubrovin, A. Lincoln, D. M. Asner, K. W. Edwards, R. A. Briere, I. Brock, J. Chen, T. Ferguson, G. Tatishvili, H. Vogel, M. E. Watkins, J. L. Rosner, N. E. Adam, J. P. Alexander, K. Berkelman, D. G. Cassel, J. E. Duboscq, K. M. Ecklund, R. Ehrlich, L. Fields, L. Gibbons, R. Gray, S. W. Gray, D. L. Hartill, B. K. Heltsley, D. Hertz, C. D. Jones, J. Kandaswamy, D. L. Kreinick, V. E. Kuznetsov, H. Mahlke-Kruger, T. O. Meyer, P. U. E. Onyisi, J. R. Patterson, D. Peterson, J. Pivarski, D. Riley, A. Ryd, A. J. Sadoff, H. Schwarthoff, X. Shi, S. Stroiney, W. M. Sun, T. Wilksen, M. Weinberger, S. B. Athar, R. Patel, V. Potlia, H. Stoeck, and J. Yelton
J. L. Rosner, N. E. Adam, J. P. Alexander, D. G. Cassel, J. E. Duboscq, R. Ehrlich, L. Fields, R. S. Galik, L. Gibbons, R. Gray, S. W. Gray, D. L. Hartill, B. K. Heltsley, D. Hertz, C. D. Jones, J. Kandaswamy, D. L. Kreinick, V. E. Kuznetsov, H. Mahlke-Kruger, P. U. E. Onyisi, J. R. Patterson, D. Peterson, J. Pivarski, D. Riley, A. Ryd, A. J. Sadoff, H. Schwarthoff, X. Shi, S. Stroiney, W. M. Sun, T. Wilksen, M. Weinberger, S. B. Athar, R. Patel, V. Potlia, J. Yelton, P. Rubin, C. Cawlfield, B. I. Eisenstein, I. Karliner, D. Kim, N. Lowrey, P. Naik, M. Selen, E. J. White, J. Wiss, R. E. Mitchell, M. R. Shepherd, D. Besson, S. Henderson, T. K. Pedlar, D. Cronin-Hennessy, K. Y. Gao, J. Hietala, Y. Kubota, T. Klein, W. Lang, R. Poling, A. W. Scott, A. Smith, P. Zweber, S. Dobbs, Z. Metreveli, K. K. Seth, A. Tomaradze, J. Ernst, K. M. Ecklund, H. Severini, W. Love, V. Savinov, O. Aquines, Z. Li, A. Lopez, S. Mehrabyan, H. Mendez, J. Ramirez, G. S. Huang, D. H. Miller, V. Pavlunin, B. Sanghi, I. P. J. Shipsey, B. Xin, G. S. Adams, M. Anderson, P. Cummings, I. Danko, D. Hu, B. Moziak, J. Napolitano, Q. He, J. Insler, H. Muramatsu, C. S. Park, E. H. Thorndike, F. Yang, T. E. Coan, Y. S. Gao, M. Artuso, S. Blusk, J. Butt, J. Li, N. Menaa, G. C. Moneti, R. Mountain, S. Nisar, K. Randrianarivony, R. Sia, T. Skwarnicki, S. Stone, J. C. Wang, K. Zhang, G. Bonvicini, D. Cinabro, M. Dubrovin, A. Lincoln, D. M. Asner, K. W. Edwards, R. A. Briere, T. Ferguson, G. Tatishvili, H. Vogel, and M. E. Watkins
M. Artuso, S. Blusk, J. Butt, S. Khalil, J. Li, N. Menaa, R. Mountain, S. Nisar, K. Randrianarivony, R. Sia, T. Skwarnicki, S. Stone, J. C. Wang, G. Bonvicini, D. Cinabro, M. Dubrovin, A. Lincoln, D. M. Asner, K. W. Edwards, P. Naik, R. A. Briere, T. Ferguson, G. Tatishvili, H. Vogel, M. E. Watkins, J. L. Rosner, N. E. Adam, J. P. Alexander, D. G. Cassel, J. E. Duboscq, R. Ehrlich, L. Fields, L. Gibbons, R. Gray, S. W. Gray, D. L. Hartill, B. K. Heltsley, D. Hertz, C. D. Jones, J. Kandaswamy, D. L. Kreinick, V. E. Kuznetsov, H. M. K. Ger, D. Mohapatra, P. U. E. Onyisi, J. R. Patterson, D. Peterson, J. Pivarski, D. Riley, A. Ryd, A. J. Sadoff, H. Schwarthoff, X. Shi, S. Stroiney, W. M. Sun, T. Wilksen, S. B. Athar, R. Patel, J. Yelton, P. Rubin, C. Cawlfield, B. I. Eisenstein, I. Karliner, D. Kim, N. Lowrey, M. Selen, E. J. White, J. Wiss, R. E. Mitchell, M. R. Shepherd, D. Besson, T. K. Pedlar, D. Cronin-Hennessy, K. Y. Gao, J. Hietala, Y. Kubota, T. Klein, B. W. Lang, R. Poling, A. W. Scott, A. Smith, P. Zweber, S. Dobbs, Z. Metreveli, K. K. Seth, A. Tomaradze, J. Ernst, K. M. Ecklund, H. Severini, W. Love, V. Savinov, O. Aquines, A. Lopez, S. Mehrabyan, H. Mendez, J. Ramirez, G. S. Huang, D. H. Miller, V. Pavlunin, B. Sanghi, I. P. J. Shipsey, B. Xin, G. S. Adams, M. Anderson, J. P. Cummings, I. Danko, D. Hu, B. Moziak, J. Napolitano, Q. He, J. Insler, H. Muramatsu, C. S. Park, E. H. Thorndike, and F. Yang
J. L. Rosner, N. E. Adam, J. P. Alexander, K. Berkelman, D. G. Cassel, V. Crede, J. E. Duboscq, K. M. Ecklund, R. Ehrlich, L. Fields, R. S. Galik, L. Gibbons, B. Gittelman, R. Gray, S. W. Gray, D. L. Hartill, B. K. Heltsley, D. Hertz, C. D. Jones, J. Kandaswamy, D. L. Kreinick, V. E. Kuznetsov, H. Mahlke-Kruger, T. O. Meyer, P. U. E. Onyisi, J. R. Patterson, D. Peterson, E. A. Phillips, J. Pivarski, D. Riley, A. Ryd, A. J. Sadoff, H. Schwarthoff, X. Shi, M. R. Shepherd, S. Stroiney, W. M. Sun, D. Urner, T. Wilksen, K. M. Weaver, M. Weinberger, S. B. Athar, P. Avery, L. Breva-Newell, R. Patel, V. Potlia, H. Stoeck, J. Yelton, P. Rubin, C. Cawlfield, B. I. Eisenstein, G. D. Gollin, I. Karliner, D. Kim, N. Lowrey, P. Naik, C. Sedlack, M. Selen, E. J. White, J. Williams, J. Wiss, K. W. Edwards, D. Besson, T. K. Pedlar, D. Cronin-Hennessy, K. Y. Gao, D. T. Gong, J. Hietala, Y. Kubota, T. Klein, B. W. Lang, S. Z. Li, R. Poling, A. W. Scott, A. Smith, S. Dobbs, Z. Metreveli, K. K. Seth, A. Tomaradze, P. Zweber, J. Ernst, A. H. Mahmood, H. Severini, D. M. Asner, S. A. Dytman, W. Love, S. Mehrabyan, J. A. Mueller, V. Savinov, Z. Li, A. Lopez, H. Mendez, J. Ramirez, G. S. Huang, D. H. Miller, V. Pavlunin, B. Sanghi, I. P. J. Shipsey, G. S. Adams, M. Cravey, J. P. Cummings, I. Danko, J. Napolitano, Q. He, H. Muramatsu, C. S. Park, W. Park, E. H. Thorndike, T. E. Coan, Y. S. Gao, F. Liu, M. Artuso, C. Boulahouache, S. Blusk, J. Butt, O. Dorjkhaidav, J. Li, N. Menaa, R. Mountain, R. Nandakumar, K. Randrianarivony, R. Redjimi, R. Sia, T. Skwarnicki, S. Stone, J. C. Wang, K. Zhang, S. E. Csorna, G. Bonvicini, D. Cinabro, M. Dubrovin, R. A. Briere, G. P. Chen, J. Chen, T. Ferguson, G. Tatishvili, H. Vogel, and M. E. Watkins
P. Rubin, N. Lowrey, S. Mehrabyan, M. Selen, J. Wiss, R. E. Mitchell, M. R. Shepherd, D. Besson, T. K. Pedlar, D. Cronin-Hennessy, K. Y. Gao, J. Hietala, Y. Kubota, T. Klein, R. Poling, A. W. Scott, P. Zweber, S. Dobbs, Z. Metreveli, K. K. Seth, B. J. Y. Tan, A. Tomaradze, J. Libby, L. Martin, A. Powell, G. Wilkinson, H. Mendez, J. Y. Ge, D. H. Miller, I. P. J. Shipsey, B. Xin, G. S. Adams, D. Hu, B. Moziak, J. Napolitano, K. M. Ecklund, Q. He, J. Insler, H. Muramatsu, C. S. Park, E. H. Thorndike, F. Yang, M. Artuso, S. Blusk, S. Khalil, J. Li, R. Mountain, K. Randrianarivony, N. Sultana, T. Skwarnicki, S. Stone, J. C. Wang, L. M. Zhang, G. Bonvicini, D. Cinabro, M. Dubrovin, A. Lincoln, M. J. Smith, P. Zhou, J. Zhu, P. Naik, J. Rademacker, D. M. Asner, K. W. Edwards, J. Reed, A. N. Robichaud, G. Tatishvili, E. J. White, R. A. Briere, H. Vogel, P. U. E. Onyisi, J. L. Rosner, J. P. Alexander, D. G. Cassel, J. E. Duboscq, R. Ehrlich, L. Fields, L. Gibbons, R. Gray, S. W. Gray, D. L. Hartill, B. K. Heltsley, D. Hertz, J. M. Hunt, J. Kandaswamy, D. L. Kreinick, V. E. Kuznetsov, J. Ledoux, H. Mahlke-Kruger, J. R. Patterson, D. Peterson, D. Riley, A. Ryd, A. J. Sadoff, X. Shi, S. Stroiney, W. M. Sun, T. Wilksen, and J. Yelton