Accurate multipath number estimation is the prerequisite for MUSIC algorithm to achieve excellent superresolution performance. To solve the problem that the existing multipath number estimation ...algorithms based on eigenvalue distribution usually require a large amount of computation, this paper proposed a fast multipath number estimation algorithm based on QR decomposition under the OFDM signal model. This algorithm only needs few times QR iteration decomposition to obtain the pseudo-eigenvalues of the matrix, and uses them to estimate the multipath number through two-step comparison. Due to the avoidance of accurate eigenvalues solution, compared with the traditional algorithms based on eigenvalue distribution, proposed algorithm's computation is smaller. Simulation results showed that the proposed algorithm has better detection performance in low SNR and few snapshots than existing algorithms.
Urban green infrastructure furnishes one of the most effective ways to mitigate and adapt to climate change and the consequent thermal environment deterioration. ENVI-met, a holistic computational ...fluid dynamics model with various plant modules, has become a principal simulation tool to evaluate the thermal effects of urban greenery. This study emphasized the significance of clear and accurate ENVI-met vegetation modeling, aiming to formulate strategies to boost modeling data quality, veracity and rigor of ENVI-met-based simulation studies. This study applied a two-step framework. First, a series of sensitivity tests were conducted under hot and humid meteorological conditions to identify the microclimate-sensitive parameters and their relative cooling effects at the pedestrian level. The results identified leaf area density as the most significant parameter in ENVI-met tree modeling. Some compromises on root properties' input accuracy could be tolerated since they would not considerably hamper the overall simulation quality at the pedestrian level. For green roof/façade modeling, leaf area index and leaf angle distribution were significant and should be accurately input to ensure simulation quality. Second, for the microclimate-sensitive parameters in modeling, this study used commonly-planted species in subtropical South China cities to demonstrate a systematic workflow of developing an ENVI-met vegetation model library. The library could include basic plant physical traits, plant albums, reference values of the microclimate-sensitive parameters, and recommended alternative modeling data sources. The vegetation model library could provide a helpful and actionable package from which researchers can quickly obtain accurate input values without highly specialized knowledge or instruments.
•The input accuracy of LAD is most influential to the overall simulation accuracy.•High tolerance is acceptable for errors of input parameter trees' root properties.•LAI and leaf angle distribution of green roof & façade are important for simulation.•Substrate properties of green roof & façade have limited influence on microclimate.•Proposed a systematic workflow to develop an ENVI-met vegetation model library.
Summary Indoor location based on Wi‐Fi fingerprint has attracted extensive attention recently, since it only requires a mobile device and existing network; it does not require additional ...infrastructure and hardware. However, localization using only received signal strength fingerprint is susceptible to dynamic environments and device heterogeneity. Localization using signal strength differences fingerprint and hyperbolic location fingerprint which extracted from received signal strength fingerprint is a powerful measure to overcome the device heterogeneity. Existing fusion‐based methods do not fully use of the mutual fusion function of multiple fingerprints, which leads to low positioning accuracy. In order to further improve the positioning accuracy, we propose a multifingerprint multiclassifier and two‐layer fusion weight positioning model. The proposed approach first creates a multiple fingerprints group by gleaning signal strength differences fingerprint and hyperbolic location fingerprint from received signal strength fingerprint. In order to deal with the accuracy decline caused by a single classifier in complex scenes, three typical classifiers, random forest (RF), K‐nearest neighbor (KNN), and support vector machine (SVM), are adopted, and a fusion weight selection algorithm is proposed to improve the localization accuracy by choosing fusion weights intelligently from the two‐layer fusion weights. Experiment results show that the proposed scheme is effective to resolve device heterogeneity, and the position accuracy is improved about 16.9% and 5.8%, respectively, compared with single fingerprint and classifier schemes. The results show that, compared with the single fingerprint scheme, the position accuracy is improved at least 16.9% and 28.4% for the homogeneous and heterogeneous equipments, respectively; as for the proposed multiclassifier fusion method, it achieves at least 5.8% and 8.7% accuracy improvement for the cases with homogeneous and heterogeneous equipments, respectively, compared with other traditional classifiers such as RF, KNN, and SVM.
Designers working on large-scale complex engineering projects may encounter design errors due to limited experience and expertise. Therefore, during the design process, accurately identifying the ...designer's design intention and recommending relevant design knowledge can enhance design efficiency and reduce errors. In this paper, we propose a closed-loop human-computer interactive design method based on sequential human intention prediction and knowledge recommendation. This method leverages the Function-Behaviour-Structure (FBS) model to reduce the dimensionality of design action sequences, so as to facilitate the analysis of potential design patterns. The processed action sequences are used to train Transformer to predict design intentions. In different input sequences, Transformer achieved a highest prediction accuracy of 92.09%. We construct a Design Knowledge Recommendation Framework (DKRF) and its corresponding design knowledge matching algorithm. This framework accurately recommends design knowledge to designers, solving design stagnation and improving design efficiency. Finally, a case study of four types of mechanical model design is conducted to demonstrate the feasibility and wide applicability of the proposed closed-loop human-computer interactive design method.
There are some interesting properties in quantum mechanics, such as quantum superposition and entanglement. We can use these features to solve some specific problems. Quantum computer has more ...advantages than classical computer in many problems. In this paper, we are interested in regular graph. A special case of graph structure destroyed is given. We present a search algorithm to find exceptional vertexes in the graph in this case. The algorithm uses the trick of amplitude amplification in quantum search algorithm. In the corresponding classical algorithm, the adjacency matrix may be used to store the information of vertex and edge of graph. It takes one time for the best and
N
times for the worst to find the target. Which means that
N
/2 times on average need to be conducted. In our quantum algorithm, nodes and vertexes are stored in quantum states, using quantum search to design algorithm. The search process can be accelerated in our quantum algorithm.
CO2-responsive and photopolymerizable prepolymers are designed and synthesized. Their good photopolymerization kinetics and reversible CO2 and N2 responses to a bulk state and in a solution are ...reported. Stepwise modulation is verified in template imprinting. Results reveal that stable and high-resolution patterns can be produced by imprinting liquid prepolymers in CO2 atmosphere, erased by warm heating, or retained permanently by chemical cross-linking through photopolymerization with the aid of a photoinitiator. By contrast, only blurry patterns are obtained in air.
对辽宁省玉米生产现状、制约生产的因素进行了分析，提出了提高辽宁省玉米生产水平的措施。著者文摘
To Liaoning province, the current situation and restrict factors of maize production were analysised, and had brought forward the measures of improving ...Liaoning province maize level of production with a view of reality.
This paper proposes a framework of users association and power allocation in the two-tier heterogeneous networks with nonorthogonal multiple access (NOMA). Taking account of practical wireless ...communication environment, the channel uncertainties are considered and described in the form of probability constraint. In order to maximize the total energy efficiency of the system and reduce the intra-cell and inter-cell interference, the joint optimization problem is formulated with the uncertain channel gain. The probability constraint is transformed to the deterministic one based on the integral transformation. With the aid of relaxation variable and successive convex approximation method, the original integer non-convex optimization problem is divided into two solvable convex subproblems. The user association algorithm and power control algorithm are presented to determine the optimal resource allocations. The simulation results show that the proposed algorithm is effective and robust to the dynamic communication environment.
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