Complicated Configurations Research Articles

Field test of Model Predictive Control in residential buildings for utility cost savings

Air conditioners in residential buildings often rely on local feedback control to regulate the indoor temperature, where the unit is cycled on and off by comparing the actual temperature with the temperature set-point. Model Predictive Control (MPC) is a technique that makes use of building models, disturbance forecasts, and optimization algorithms to enhance building performance. MPC has demonstrated its potential in reducing building energy consumption and operating costs; however, it has seldom been applied in residential buildings because of the high implementation costs, complicated hardware configuration, and insufficient data. In this study, we developed and tested a MPC controller in a real apartment aimed at reducing the operating costs based on the local Time-of-Use (ToU) utility structure. We developed a feasible and easy-to-use hardware configuration as well as a cloud-based software deployment. The MPC controllers were implemented and evaluated through one-month field testing in a bedroom and living room of an apartment in a residential building. The field test showed that the MPC controller saved 22.1% for the bedroom and 26.8% cooling costs for the living room, compared to conventional rule-based control (RBC). We further confirmed the robustness of the MPC controller as the field test showed that the MPC controller is able to outperform the conventional RBC controller, even if the model is not accurate. Our work provides a practical MPC solution that can unlock the load flexibility potential of residential buildings, which creates a win–win solution for the households and the grid: saving utility costs for households and helping the grid to manage the balance between supply and demand.

Smearing and unsmearing KKLT AdS vacua

Gaugino condensation on D-branes wrapping internal cycles gives a mechanism to stabilize the associated moduli. According to the effective field theory, this gives rise, when combined with fluxes, to supersymmetric AdS4 solutions. In this paper we provide a ten-dimensional description of these vacua. We first find the supersymmetry equations for type II AdS4 vacua with gaugino condensates on D-branes, in the framework of generalized complex geometry. We then solve them for type IIB compactifications with gaugino condensates on smeared D7-branes. We show that supersymmetry requires a (conformal) Calabi-Yau manifold and imaginary self-dual three-form fluxes with an additional (0,3) component. The latter is proportional to the cosmological constant, whose magnitude is determined by the expectation value of the gaugino condensate and the stabilized volume of the cycle wrapped by the branes. This confirms, qualitatively and quantitatively, the results obtained using effective field theory. We find that exponential separation between the AdS and the KK scales seems possible as long as the three-form fluxes are such that their (0,3) component is exponentially suppressed. As for the localized solution, it requires going beyond SU(3)-structure internal manifolds. Nevertheless, we show that the action can be evaluated on-shell without relying on the details of such complicated configuration. We find that no “perfect square” structure occurs, and the result is divergent. We compute the four-fermion contributions, including a counterterm, needed to cancel these divergences.

Segment-Dependent Gene Expression Profiling of the Cartilaginous Fish Nephron Using Laser Microdissection for Functional Characterization of Nephron at Segment Levels.

For adaptation to a high salinity marine environment, cartilaginous fishes have evolved a ureosmotic strategy. They have a highly elaborate "four-loop nephron" in the kidney, which is considered to be important for reabsorption of urea from the glomerular filtrate to maintain a high concentration of urea in the body. However, the function and regulation, generally, of the "four-loop nephron" are still largely unknown due to the complicated configuration of the nephron and its many subdivided segments. Laser microdissection (LMD) followed by RNA-sequencing (RNA-seq) analysis is a powerful technique to obtain segment-dependent gene expression profiles. In the present study, using the kidney of cloudy catshark, Scyliorhinus torazame, we tested several formaldehyde-free and formaldehyde-based fixatives to optimize the fixation methods. Fixation by 1% neutral buffered formalin for 15 min resulted in sufficient RNA and structural integrities, which allowed LMD clipping of specific nephron segments and subsequent RNA-seq analysis. RNA-seq from the LMD samples of the second-loop, the fourth-loop, and the five tubular segments in the bundle zone revealed a number of specific membrane transporter genes that can characterize each segment. Among them, we examined expressions of the Na + -coupled cotransporters abundantly expressed in the second loop samples. Although the proximal II segment of the second loop is known for the elimination of excess solutes, the present results imply that the PII segment is also crucial for reabsorption of valuable solutes. Looking ahead to future studies, the segment-dependent gene expression profiling will be a powerful technique for unraveling the renal mechanisms and regulation in euryhaline elasmobranchs.

Numerical simulations of the nonlinear quantum vacuum in the Heisenberg-Euler weak-field expansion

The nonlinear Heisenberg-Euler theory is capable of describing the dynamics of vacuum polarization, a key prediction by quantum electrodynamics. Due to vast progress in the field of laser technology in recent years vacuum polarization can be triggered in the lab by colliding high-intensity laser pulses, leading to a variety of interesting novel phenomena. Since analytical methods for highly nonlinear problems are generally limited and since the experimental requirements for the detection of the signals from the nonlinear quantum vacuum are high, the need for numerical support is apparent. The paper presents a highly-accurate, efficient numerical scheme for solving the nonlinear Heisenberg-Euler equations in weak-field expansion up to six-photon interactions. Properties of the numerical scheme are discussed and an implementation accurate up to order thirteen in terms of spatial resolution is given. Simulations are presented and benchmarked with known analytical results. The versatility of the numerical solver is demonstrated by solving problems in complicated configurations.

Multimodal Neuromorphic Sensory-Processing System With Memristor Circuits for Smart Home Applications

To enable smart home applications, embedding home monitoring systems with different sensors can be a feasible remedy to capture the multimodal sensory information from daily life. However, the previously developed monitoring systems have high implementation cost, large power consumption, and complicated device configuration, which are not conducive to achieving carbon neutrality and carbon peak goals. Here, we demonstrate a multimodal neuromorphic sensory-processing system with memristor circuits for smart homes, offering a more environmentally friendly approach with low cost and easily deployable hardware. We used three components to facilitate the multimodal neuromorphic sensory-processing system design. First, a memristor crossbar array is fabricated using low-cost, reliable, and eco-friendly 2-D materials; enabling a parallel connection to reduce the system complexity and the deep-learning computational cost. Second, a neuromorphic multimodal sensory-processing module is designed for collecting and processing multiple sensory cues efficiently; to establish accurate depiction of the environment and realize timely response. Third, the biomimetic hierarchical learning module is realized for smart home monitoring and relative applications (e.g., indoor human behavior recognition). The developed multimodal neuromorphic sensory-processing system effectively combines the nanotechnology, intelligent sensing, and deep learning; indicating an advancement in smart home applications.

Observation of Hidden Asymmetry in Polarization Space for Dissipative Soliton Fiber Lasers

Dissipative solitons appear widely in physical systems with dissipative energy exchange, which have been regarded as an excellent platform for exploring nonlinear dynamics. The complex interactions among dispersion management and nonlinearity result in abundant asymmetric behaviors in diverse parameter spaces. Nevertheless, conventional detection methods impede direct and single-shot measurements of the transient polarization dynamics of dissipative solitons. Here, by using the division-of-amplitude method combined with dispersive Fourier transform techniques, we have experimentally observed the internal evolution of dissipative solitons in polarization space. By disturbing the cavity birefringence, we obtain asymmetrical spectra due to nonlinear phase evolution within numerous temporal roundtrips. The different phases across the lasing wavelengths result in wavelength-resolved symmetric breakage in polarization space, which is difficult to find in spectrum or pulse-shape measurements. The direct observation of hidden asymmetry in polarization space for dissipative soliton fiber lasers will facilitate theoretical modeling of mode-locked laser systems with complicated configurations, and it may also promote applications for polarization spectroscopy.

분산전원이 있는 배전계통에서 딥러닝을 통한 고저항 지락사고 판별

This paper proposes a method to detect a high-resistance ground fault in a distribution system with complicated configuration such as installation of a distributed generation. A method to detect high-resistance ground fault accidents by converting the fault current into visual data and applying the CNN technique to this is presented and verified. The data for learning the CNN technique was generated through simulation of the model system. Simulations were performed for data generation by changing the fault resistance, the size, location of faults and amount of distributed power generation, in the case of a high-resistance ground fault and an increase in load in the model system. The generated data was transformed into graphic data by applying Morlett wavelet transform, and then learning was performed by applying CNN. As a result of the learning, high-resistance ground faults were identified with 98.29% accuracy, and a protective algorithm including this result that can respond to high-resistance ground faults occurring in the distribution system was proposed.

Biological nitrogen removal from low carbon wastewater.

Nitrogen has traditionally been removed from wastewater by nitrification and denitrification processes, in which organic carbon has been used as an electron donor during denitrification. However, some wastewaters contain low concentrations of organic carbon, which may require external organic carbon supply, increasing treatment costs. As a result, processes such as partial nitrification/anammox (anaerobic ammonium oxidation) (PN/A), autotrophic denitrification, nitritation-denitritation and bioelectrochemical processes have been studied as possible alternatives, and are thus evaluated in this study based on process kinetics, applicability at large-scale and process configuration. Oxygen demand for nitritation-denitritation and PN/A is 25% and 60% lower than for nitrification/denitrification, respectively. In addition, PN/A process does not require organic carbon supply, while its supply for nitritation-denitritation is 40% less than for nitrification/denitrification. Both PN/A and nitritation-denitritation produce less sludge compared to nitrification/denitrification, which saves on sludge handling costs. Similarly, autotrophic denitrification generates less sludge compared to heterotrophic denitrification and could save on sludge handling costs. However, autotrophic denitrification driven by metallic ions, elemental sulfur (S) and its compounds could generate harmful chemicals. On the other hand, hydrogenotrophic denitrification can remove nitrogen completely without generation of harmful chemicals, but requires specialized equipment for generation and handling of hydrogen gas (H2), which complicates process configuration. Bioelectrochemical processes are limited by low kinetics and complicated process configuration. In sum, anammox-mediated processes represent the best alternative to nitrification/denitrification for nitrogen removal in low- and high-strength wastewaters.

Compact functional elastic waveguides based on confined mode

Waveguides realized by defected phononic crystals or topological metamaterials possess strong abilities of energy flux rectifying, but suffer from great challenges in practical applications due to their bulky sizes, complicated configurations or narrow working band. Here we present a compact and frequency-robust waveguide squeezed by two layers of metagratings with only one identical unit cell, which we call metafence, to efficiently guide flexural waves in thin plates. Apart from the guided modes, a confined mode is numerically and experimentally observed by designing the waveguide width below a tailored threshold. Excitingly, this confined mode can be converted into a guided mode by easily introducing a couple of obstacles. Such feasible and efficient mode steering allows us to demonstrate robust total-wave-trapping and switchable directional guiding. The designed prototype may enrich the scope of nontrivial modes of elastic waveguides and expand the pathway of tunable energy routing scenarios.

Temporal Bone Anatomy

Temporal bone anatomy is highly complex, with a complicated configuration of minute anatomic structures housed in a dense osseous structure. Nevertheless, a robust understanding of this anatomy is essential for clinicians, who must accurately diagnose and describe the various pathologies that exist in this region. In this article, we provide a comprehensive overview of temporal bone anatomy, ranging from its large components to its smallest foramina, canals, and clefts.

Scaling operator demodulation spectrum-based planetary gearbox fault diagnosis method under variable speed conditions

It is a challenging task to detect planetary gearbox fault type under time-varying speeds. Firstly, under time-varying speeds, the fault-induced frequency harmonics of the planetary gearbox are time-varying and close-spaced, and the fault feature is difficult to detect from the spectrum or traditional time-frequency analysis (TFA) results. Secondly, the interference component in the vibration signal resulting from the complicated gearbox configuration is another obstacle for fault detection. As such, the scaling operator demodulation spectrum (SODS) technique with high readability is developed for planetary gearbox fault diagnosis under variable speed conditions. The developed technique consists of two terms: scaling demodulation operator term for transforming all time-varying fault-related frequency harmonics; and spectral selection criterion term for obtaining fault-related frequency harmonics and removing the other smeared frequency components. With the proposed technique, the time-varying and close-spaced fault-induced frequency harmonics can be quantitatively characterized by the spectral peaks. The performance of the SODS-based planetary gearbox fault diagnosis technique is validated by a simulated signal and two experimental signals collected from different test rigs. Furthermore, comparison results with the traditional TFA methods show that the proposed technique has much better ability to identify the fault-related frequency harmonics of the planetary gearbox.

Anisotropic cellulose nanofibril aerogels fabricated by directional stabilization and ambient drying for efficient solar evaporation

Anisotropic aerogels, mimicking natural porous materials such as wood and bone, always exhibit distinctive properties due to their aligned channels, which, however, generally require complicated ice templating configuration and costly freeze-drying. In this work, we develop a novel, facile, low-cost, and scalable method combining directional stabilization and ambient drying to prepare anisotropic aerogels. The frozen aqueous TEMPO-oxidized cellulose nanofibrils (TOCNFs) monolith embedded in a mold is directly immersed in ethanol/Fe3+ bath. The ice crystals directionally dissolve in ethanol, and simultaneously the TOCNFs are directionally stabilized due to the electrostatic complexation between their carboxyl groups and Fe3+ ions. The obtained anisotropic nanocellulose aerogel (NCA) after ambient drying exhibits an ordered porous structure, which is tunable by adjusting the contents of carboxyl groups on TOCNFs. The NCAs reveal distinct anisotropy, excellent mechanical compressibility in the radial direction, and high water-stability. To demonstrate their promising potentials for application in various advanced fields such as solar steam generation, the NCA is coated with polypyrrole (PPy) by in-situ polymerization to achieve excellent photothermal property but well maintain the original aligned channels of NCA, which endow the NCA@PPy with an efficient solar evaporation performance.

Enhanced strategy for adaptive Cartesian grid generation with arbitrarily complex 3D geometry

This article presents an enhanced strategy for generating Cartesian grids for arbitrary complex three-dimensional (3D) geometry. It addresses the major challenges, including data structures managing surface triangles and Cartesian cells, background Cartesian generation, intersection cell determination, and adaptive mesh refinement. To overcome the problem of inefficiency, we developed a robust method for determining intersecting cells based on the k-dimensional tree data structure combined with the fast 3D-Cartesian box-triangle overlap testing algorithm. Furthermore, the minimum distance query algorithm based on the k-dimensional tree was enhanced to improve the query efficiency by reducing the number of backtrackings. The correctness and efficiency of the proposed strategy were evaluated and verified by 3D tests on different configurations. The results show that in terms of mesh generation, the CPUtime∕cell was nearly 5.33–5.54×10−6 s; in terms of the minimum distance query, the query efficiency of the improved backtracking method improved by up to 870.9 times compared with the traversal method. Meshing experiments of several complicated configurations demonstrated that the proposed algorithms were accurate, robust, and efficient. At last, an example was examined, and the result demonstrates that the mesh generation strategy developed in this study meets the actual flow field calculation requirements.

A compact and cost effective quasi-in-situ method to characterize broadband RF shielding effectiveness of materials for advanced microelectronic packaging

At present, one of the major measures to suppress electromagnetic (EM) radiation inside advanced integrated microelectronic packages is the proper placement of electromagnetic shielding. Existing shielding effectiveness (SE) characterization technologies are always intended for enclosure evaluation, which are costly and time consuming, demanding complicated test instrument configuration, fixture setup, and a large room to accommodate the whole test system, especially when broadband test is required in which a series of narrowband antennas are to be switched during the test; additionally, the way test samples are assembled is quite different from that in the final package application. Therefore, their practical value and adaptation in SE evaluation are limited in the view of the professionals engaged in micro/nano electronics package research, development, manufacturing and application, and indeed there exist urgent desires for a compact and cost-effective technology characterizing in-situ the broadband effectiveness of shielding materials for EM radiation suppression in high-density heterogeneously integrated packages and relevant miniaturized system integration scenarios. Accordingly, in this paper a compact dual-port microstrip antenna test fixture working in pairs is designed and prototyped, which provides a quasi in-situ environment for the test sample, and only a vector network analyzer (VNA) is needed which just measures the fixture port scattering parameters so as to conveniently and faithfully reveal the SE. Solid modeling and full-wave simulation for the broadband return loss, insertion loss and radiation pattern of the test setup are carried out by a high-frequency electromagnetic structural analysis software for design verification. The actual test is carried out by loading heat insulation board, heat insulation board laminated with aluminum foil, PureBlue board and FR4 board samples. By comparing the SE of different materials, the validity for the proposed microstrip antenna test fixture in characterization is confirmed.

A priori and a posteriori studies of a novel spray flamelet tabulation methodology considering evaporation effects

Turbulent spray flames are complicated combustion configurations involving many coupled processes including atomization, evaporation, mixing, chemical reactions, etc. Different flamelet models with intrinsically high computational efficiency have been proposed and extended to model spray combustion. One popular approach for flamelet modeling is based on the gaseous flamelet library, but the accuracy is not guaranteed for combustion with gas–liquid two-phase flows. The other approach is based on the spray flamelet library that takes into account the effects of evaporation on the flamelet structure, but problems related to the non-monotonicity of mixture fraction occur. We develop a novel tabulated spray flamelet/progress variable (TSFPV) model in the present work. An additional mixture fraction Zcarr (named carrier mixture fraction) is defined to describe the mixing process, and it proves to avoid the problem of non-monotonicity of the spray flame structure. The empirical formulas of mass and energy evaporation source terms are obtained and then applied to one-dimensional flames in order to create the flamelet library considering evaporation effects. The developed TSFPV model is validated via simulations of laminar spray counterflow flame and turbulent spray reactive jet in cross-flow, where strong interactions between spray droplets and flame occur and the traditional Flamelet/Progress Variable (FPV) model fails. The a priori and a posteriori studies of TSFPV model are conducted, and the model shows to achieve good agreement with the detailed chemistry solutions. The double-reaction spray flame structure can be captured correctly. The TSFPV model can also give sound quantitative predictions for temperature and minor intermediate products (such as OH, C2H2, and C2H4).

Details study on the kinematic characteristics of manta ray section in flapping motion and exploring its application in wave glider propulsion system

It has always been a human challenge to inspire natural configurations and phenomena and benefit from their merits in improving the performances of man-made proposed aero/hydro vehicles. For example, the manta rays are known for their great swimming performances. To design and fabricate an underwater robot based on the manta ray geometry and its kinematic characteristics, it is important to initially study its hydrodynamic behavior and possibly arrive at some key design parameters, which can remarkably help to figure out an optimum geometry with high swimming performances. The main objective of this study is to focus on the merits of gliding motion inspired by the manta ray fish considering the real sea conditions. In this regard, two wave-glider configurations with specific submersible geometries are selected to practice the bases of this objective. They are the manta-glider, which has a complicated 3D configuration representing the real manta ray swimming behavior, and the wing-glider, which has much simpler configuration constructing from a flat and uniform wing span shape. The 3D unsteady incompressible Navier-Stokes equations are numerically solved to simulate the gliding motion performances of these two gliders. The results show that the maximum efficiency of manta-glider model is ηmax = 50 %, which is much higher than that of the wing-glider with ηmax = 36 %, within an operational range with a relatively constant significant wave height (SWH). Alternatively, the wing-glider efficiency is about 5 % higher than that of the manta-glider in cases with non-constant SWH values. Irrespective of their efficiencies, the interesting outcome of this study is that the manta-glider model shows fewer fluctuations and performs more stable conditions than a simplified glider model in energy-absorbing applications. Considering the achieved outcomes, this work also suggests a simple guideline, which is so beneficial to arrive at a suitable wave glider propulsion design.

Specific behavior of transition metal chloride complexes for achieving giant ionic thermoelectric properties

When people are keen to exploring the thermoelectric properties of polymer composite inorganic electrolyte aqueous flexible electronic devices, the complicated chemical configuration of transition metal chloride anion has not been paid attention and reported. Here, we demonstrate a hydrated polyvinyl alcohol (PVA)-cellulosic membrane that relies on the thermal gradient diffusion of transition metal and chloride complexe [CuCl4]2− enhanced by copper-coordinated carboxylated cellulose. The PVA-cellulosic membrane exhibits a thermopower of −26.25 mV·K−1, rendering it among the best n-type ionic thermoelectric materials under the same conditions. We attribute the enhanced thermally generated voltage to the highly-coordinated configuration of Cu2+ - Cl−, which converts the independent thermal motion of Cu2+ and Cl− to the higher ion transport heat of [CuCl4]2− anion via carboxylated cellulose, while this phenomenon do not occur in the other transition metal chlorides. This specific heat transport behavior of [CuCl4]2− has important implications in designing high-quality ionic thermoelectric materials.

Dot products in [formula omitted] and the Vapnik-Chervonenkis dimension

Given a set E⊂Fq3, where Fq is the field with q elements. Consider a set of “classifiers” Ht3(E)={hy:y∈E}, where hy(x)=1 if x⋅y=t, x∈E, and 0 otherwise. We are going to prove that if |E|≥Cq114, with a sufficiently large constant C>0, then the Vapnik-Chervonenkis dimension of Ht3(E) is equal to 3. In particular, this means that for sufficiently large subsets of Fq3, the Vapnik-Chervonenkis dimension of Ht3(E) is the same as the Vapnik-Chervonenkis dimension of Ht3(Fq3). In some sense the proof leads us to consider the most complicated possible configuration that can always be embedded in subsets of Fq3 of size ≥Cq114.

Immersed Virtual Element Methods for Elliptic Interface Problems in Two Dimensions

This article presents an immersed virtual element method for solving a class of interface problems that combines the advantages of both body-fitted mesh methods and unfitted mesh methods. A background body-fitted mesh is generated initially. On those interface elements, virtual element spaces are constructed as solution spaces to local interface problems, and exact sequences can be established for these new spaces involving discontinuous coefficients. The discontinuous coefficients of interface problems are recast as Hodge star operators that are the key to project immersed virtual functions to classic immersed finite element (IFE) functions for computing numerical solutions. An a priori convergence analysis is established robust with respect to the interface location. The proposed method is capable of handling more complicated interface element configuration and provides better performance than the conventional penalty-type IFE method for the \(\mathbf{H}({\text {curl}})\)-interface problem arising from Maxwell equations. It also brings a connection between various methods such as body-fitted methods, IFE methods, virtual element methods, etc.

The Study of Optimal Performance Improvement Method for Aircraft of Various Variants within the Same Type

In this paper, we studied the optimal method of improving performance for aircraft having various variants within the same type. The study defined configuration of an entire fleet of aircraft being subject to a performance improvement program. And selected the most complicated aircraft configuration among them as a Standard Aircraft for modification by according to the proposed Aircraft Selection Process for developing an optimal Aircraft Performance Improvement Process. Based on the selected the Standard Aircraft, drew a system integration design result and carried out Evaluation Test and obtained Airworthiness Certification. Created the database with the design data of the Standard Aircraft, Evaluation Test, and Airworthiness Certification results, and applied it to variants of aircraft to complete the performance improvement program with optimized schedules and costs. By applying the proposed method to IFF performance improvement program, drew optimal system integration design and completed the program with minimized schedule.