As computer and multimedia technology advances and as the variety of knowledge display forms expands, there are more ways for people to obtain knowledge and information. The best course in musicology ...is voice performance. A crucial issue is how to select and categorize valuable curriculum materials of varying quality levels. This paper implements an automatic classification and integration algorithm for vocal performance learning materials using machine learning technology and tests it on the corresponding dataset, beginning with multidimensional association rule mining technology and the premise that multimedia data contain numerous useful characteristics. Experiments demonstrate the classification precision and data integration capacity of the proposed algorithm. Vocal performance is the most engaging course in musicology. To cultivate corresponding talents, we can rely on college and university offline courses and the rapidly developing multimedia technology to train talents online. An important topic is how to efficiently select and classify curriculum materials of varying quality in order to provide them to students with different learning needs. We can achieve the automatic classification of the course content by leveraging the superior learning capabilities of artificial intelligence and machine learning technology. Consequently, this paper implements an automatic classification and integration algorithm for vocal performance learning materials using machine learning-related technology and conducts an experimental test on the corresponding dataset, beginning with multidimensional association rule mining technology and the perspective that multimedia information itself contains a large number of useful characteristics. Experiments demonstrate that the proposed algorithm has a high level of classification accuracy and data integration capability.
With the increasing prosperity of the cultural market, the dance culture industry is also developing rapidly. In the face of opportunities and challenges brought by dance industrialization, dance ...professionals trained by the traditional and single-skill training system of art colleges and universities expose the contradiction between supply and demand. In this paper, the SAA-training model is taken as the calculation tool, and the OBE and Kinect motion capture technology are combined to explore the construction and practice of the training system for dance professionals. The research shows that the training system of dance professionals can finally obtain three types of dance professionals. The first type is compound dance talents, accounting for about 33%. The second category consists of dancers with rich market experience, accounting for up to 46 percent. The third category is dance talent with innovative consciousness, limited by the existing training mode, its proportion is only 21 percent.
Markets for ramp products (called "flexiramp" in the California ISO and "ramp capability" in the Midcontinent ISO) have been proposed to address the need for generator flexibility due to increased ...renewable penetration. Flexiramp is committed capacity reserved to meet unexpected ramps in net load. We evaluate flexiramp market designs by comparing solutions of 1) an ISO real-time market simulation (a deterministic real-time unit commitment (RTUC) model with flexiramp requirements) with 2) a stochastic RTUC model, used as a baseline for evaluating flexiramp solutions. The flexiramp constraint improves the expected performance of ISO real-time markets, but is inefficient compared to stochastic RTUC. Flexiramp markets are inefficient in part because the deterministic model disregards the possibility of higher than anticipated energy production by capacity reserved for ramp. Thus, for instance, capacity with low commitment costs but high running costs might be overcommitted, increasing energy costs under high ramp outcomes. The amount of flexiramp acquired strongly affects costs. Too little results in under-commitment of generators and high price fluctuations and even demand curtailment; too much leads to over-commitment, inflating production costs. Hence, careful design of the ramp market and consideration of the use of full stochastic dispatch and commitment models is recommended.
The purpose is to compare the development of innovative thinking in two groups of students who learn the intangible cultural heritage of the ancient ethnic group and master oil painting techniques in ...two formats: distantly and visiting the Miao settlement in the deep southeast of Guizhou. In addition to the traditional learning of oil painting techniques, the students learnt folklore and the cultural heritage of ethnic minorities as a part of the art curriculum. For practice, the control group (96 students) visited the villages of Miao in Guizhou, and the experimental group (96 students) gained experience and knowledge about the Miao ethnic minority distantly, through videos and e-discussions. At the end of the training, the students presented their final oil paintings on the life of the Miao. They have been assessed by teachers and art critics to identify innovative thinking among students as a driving force of creativity. The control group showed higher results on parameters such as Integrity (454 points) and Flexibility (287 points). The high-end result of the control group proved that innovative thinking is best developed by immersing students in the real world of the Miao and allowing them to experiment and feel their works.
A series of CuOx-decorated ZnFe2O4 samples were prepared by a hydrothermal method and investigated as a catalyst for the photocatalytic and Fenton-like degradation of Orange II. The active species ...and catalyst active sites in the two processes were also studied. It was found that the introduced CuOx significantly enhanced the photocatalytic and Fenton-like performance of ZnFe2O4. Especially, ZnFe2O4-Cu3 prepared with the Cu/Zn ratio of 3:7 exhibited a very high Fenton-like activity in the pH range 5-9. The enhanced photocatalytic activity of ZnFe2O4-Cu3 could be because the formed ZnFe2O4/Cu2O heterojunction improved the separation efficiency of the photogenerated carriers. The photogenerated hole was responsible for Orange II degradation. As for the Fenton-like reaction, •O2- was the active species, and the surface ≡Cu2+ with a higher redox ability should be the active site for H2O2 activation despite its lower surface content than that of ≡Cu+, ≡Fe2+, and ≡Fe3+. Finally, a possible pathway for Orange II degradation was proposed according to the liquid chromatography-mass spectrometry result.
This paper explores the rate-energy (R-E) region of simultaneous wireless information and power transfer for MIMO broadcasting channel under the nonlinear radio frequency energy harvesting (EH) ...model. The goal is to characterize the tradeoff between the maximal energy transfer versus information rate. The separated EH and information decoding (ID) receivers and the co-located EH and ID receivers scenarios are considered. For the co-located receivers scenario, both time switching (TS) and power splitting (PS) receiver architectures are investigated. Optimization problems are formulated to derive the boundaries of the R-E region s for the considered systems. As the problems are nonconvex, we first transform them into equivalent ones and derive some semi-closed-form solutions, and then design efficient algorithms to solve them. Numerical results are provided to show the R-E region s of the systems, which provide some interesting insights. It is shown that all practical circuit specifications greatly affect the system R-E region. Compared with the systems under traditional linear EH model, the ones under the nonlinear EH model achieve smaller R-E region s due to the limitations of practical circuit features and also show very different R-E tradeoff behaviors.
Advances in cognitive radio networks: A survey Beibei Wang; Liu, K J R
IEEE journal of selected topics in signal processing,
2011-Feb., 2011-02-00, 20110201, Letnik:
5, Številka:
1
Journal Article
Recenzirano
Odprti dostop
With the rapid deployment of new wireless devices and applications, the last decade has witnessed a growing demand for wireless radio spectrum. However, the fixed spectrum assignment policy becomes a ...bottleneck for more efficient spectrum utilization, under which a great portion of the licensed spectrum is severely under-utilized. The inefficient usage of the limited spectrum resources urges the spectrum regulatory bodies to review their policy and start to seek for innovative communication technology that can exploit the wireless spectrum in a more intelligent and flexible way. The concept of cognitive radio is proposed to address the issue of spectrum efficiency and has been receiving an increasing attention in recent years, since it equips wireless users the capability to optimally adapt their operating parameters according to the interactions with the surrounding radio environment. There have been many significant developments in the past few years on cognitive radios. This paper surveys recent advances in research related to cognitive radios. The fundamentals of cognitive radio technology, architecture of a cognitive radio network and its applications are first introduced. The existing works in spectrum sensing are reviewed, and important issues in dynamic spectrum allocation and sharing are investigated in detail.
Sodium and potassium ion batteries (SIBs and PIBs) have received a substantial amount of attention in large-scale applications due to the abundance and low price of sodium and potassium metals. ...However, large-sized Na+ and K+ ions can cause sluggish kinetics, large volume change and unsatisfactory cycling behaviors. Herein, highly dispersed FeSe2 nanoparticles confined in mesoporous carbon nanofibers (FeSe2@C) were prepared via a novel selenization strategy and utilized as an anode material in both SIBs and PIBs for the first time. The mesoporous FeSe2@C nanocomposite possesses unique structural features including a large surface area and the presence of highly dispersed FeSe2 nanoparticles and a 1D mesocarbon nanofiber matrix, which can efficiently enhance electrical conductivity, facilitate electron/ion transportation and alleviate volume variations, thereby enabling fast Na/K storage kinetics, an outstanding structural integrity and a superior Na/K storage performance. For SIBs, FeSe2@C shows a high charge capacity of 483 mAh g−1 at 0.2 A g−1 over 100 cycles, which retains a capacity of 359 mAh g−1 after 200 cycles at 1.0 A g−1. When employed as anode for PIBs, FeSe2@C displays a high charge capacity of 352 mAh g−1 at 0.1 A g−1. Moreover, the electrochemical kinetic analysis confirms that the excellent pseudocapacitive behavior accounts for the superior sodium/potassium storage performance at high current densities.
•Porous FeSe2@C nanofibers were prepared via a novel selenization strategy.•The FeSe2@C nanofibers show superior Na/K storage performance.•The high capacity of FeSe2@C is due to the fast Na/K storage kinetics.
•Compares a deterministic dispatch market with flexiramp with stochastic dispatch.•The results illustrate how up- and down-flexiramp enhance market efficiency.•But flexiramp constraint is ...insufficient to produce the least (expected) cost.•The exact parameters of the constraint affect the quality of the solutions.•A penalty approach is proposed to decrease the possible inefficiency of flexiramp.
U.S. Independent System Operators (ISOs) are creating short-run markets for so-called “flexiramp”. The aim of these markets is to ensure that enough flexible generation capacity is on-line to manage the increasingly volatile net loads resulting from growth in renewable energy. In particular, we assume that the purpose of flexiramp is to improve the expected performance, in terms of costs, prices, and reliability, of the ISOs’ deterministic market models. Therefore, we compare the solutions of (1) a deterministic dispatch model with a flexiramp constraint that simulates ISO operations with (2) a stochastic dispatch model that, by definition, obtains schedules that minimize expected cost. Dispatch, prices, settlements, and market efficiency are contrasted in a simplified case study to explore the fundamental reasons for successes (and failures) of flexiramp markets. The results illustrate how flexiramp can enhance market efficiency. However, they also show that procuring flexiramp is insufficient to minimize expected costs, and that market parameters affect the quality of the solutions. The simulations furthermore show that deterministic markets with flexiramp can yield either higher or lower prices than the stochastic optimum. We propose a penalty-based approach to mitigate possible biases towards choosing capacity with high energy costs to provide flexiramp, and conclude that market operators will need to monitor market performance and adjust flexiramp parameters in order to maximize market efficiency.
With the growing development in demand response, load serving entities (LSEs) may participate in electricity market as strategic bidders by offering coupon-based demand response (C-DR) programs to ...customers. However, due to customers' versatile electricity consumption patterns under C-DR programs as well as the increasing penetration of wind power generation, obtaining the deterministic bidding decision becomes unprecedented complex for LSEs. To address this challenge, a new strategic bidding model for an LSE is proposed in which the primary objective is to maximize the LSE's profit by providing optimal C-DR considering high wind power penetration. The proposed strategic bidding is a bi-level optimization problem with the LSE's net revenue maximization as the upper level problem and the ISO's economic dispatch (ED) for generation cost minimization as the lower level problem. This bi-level model is converted to a stochastic mathematic program with equilibrium constraints (MPEC) by recasting the lower level problem as its Karush-Kuhn-Tucher (KKT) optimality conditions. Then, the stochastic MPEC is transformed to a mixed-integer linear programming (MILP) problem, which is solvable using available optimization software, based on strong duality theory. In addition, the effectiveness of the proposed method has been verified with simulation studies of two sample systems.
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