最新刊期
卷 46 ， 期 11 ， 2018
- 摘要：The wireless channel in wireless network-on-chip faces serious reliability challenges. The fault-tolerant design of wireless routers has a great impact on the transmission efficiency of the entire network onchip. This paper presents a highly efficient acknowledgement feedback (EF-ACK) fault-tolerant wireless interface design. Several confirmation information is configured in a data packet, which can be transmitted over the wireless channel. Establish a retransmission data buffer at the wireless interface to validate the data in the most efficient manner and to control the retransmission of erroneous data packets. In addition, a network-state-based codec control is proposed, which improves the robustness of the data by means of BCH coding when the network conditions are poor. It can be concluded that the proposed scheme efficiently performs wireless acknowledgment feedback on data with only a small additional area and power consumption overhead and ensures a lower network latency and higher Saturated throughput in the network when the error rate is serious, greatly improving the performance of the network.关键词：wireless network onchip;fault tolerant;ACK;wireless channel;wireless interface147|329|2更新时间：2025-07-16
- 摘要：Existing information service entities (ISE) in various domains (PKI domain and IBC domain) interact more frequent. To solve the obstacle to the development of services caused by unsafe and inefficient cross-domain authentication, a novel blockchain-based cross-domain authentication scheme is proposed. A blockchain domain agent server is set in IBC to participate in SM9 key generation and build up the consortium blockchain model along with the blockchain certificate server (PKI). Based on the high credible model with the advantages of blockchain technology, a cross-domain authentication protocol and re-authentication protocol are proposed, and are proved by SOV logic. Compared with the related schemes, our scheme reduces the computation and communication on user side and simplifies the heavy authentication process. Therefore, the scheme has good practicability in domain authentication.关键词：across domains authenticated;blockchain;SM9;information services435|830|25更新时间：2025-07-16
- 摘要：Knowledge of X-ray spectrum is essential in many applications of X-ray computed tomography (CT), such as spectral CT imaging, beam hardening correction, quantitative analysis of CT images, etc. But the spectrum of an X-ray source is hard to measure with X-ray spectrometer directly due to strong X-ray flux emitted. Other kind of attractive methods are indirect, which estimate the x-ray spectrum from a set of projection data of phantoms with different thicknesses. In indirect methods, the spectrum estimation problem is boiled down to a set of ill conditioned linear equations. To acquire accurate spectrum, a large number of measurements are required, which needs heavy workload. To overcome the abovementioned obstacle, we propose a novel X-ray spectrum estimation method that first fits the polychromatic projection curve with quadratic rational fraction, and then estimate the X-ray spectrum from the sampling points of the fitted curve. As a quadratic rational fraction includes only three parameters, only a few measurements are needed to get an accurate fitting. Numerical experiments show that the accuracy of the X-ray spectrum estimated through the proposed method with three measurements is commensurate to that estimated with tradition method from over a dozen of measurements. Therefore, the proposed method lessens the workloads effectively.关键词：X-ray spectrum estimation;projection data;polychromatic projection curve;quadratic rational fraction129|228|1更新时间：2025-07-16
- 摘要：Most of the existing level set methods for multi-region use complex energy functions to drive the evolution of multiple level sets, which not only makes the model more complex but also has many limitations. In this paper, we propose a fast multi-region active contour method based on texture features by using an arbitrary number of level sets functions to segment an image into regions of the corresponding amount. We first establish a joint distribution of color and texture information and bring it into data term of energy function. Then, we introduce the smooth probability label and establish an update equation of level set function for multi-region driven by probability labels. And, each level set for different regions is projected into the discrete space to get a series of approximate labels. Due to these labels, a prior probability based on multi-level-sets is obtained, which introduce the evolution information of multiple contours into the statistical framework. The statistical parameters of each region are also updated iteratively from the smooth probability labels by minimizing the energy function. We experimentally compare the proposed approach with other methods on complicated real-world images and demonstrate its good performance in practice.关键词：image segmentation;level set;multi-region segmentation;active contours216|393|4更新时间：2025-07-16
- 摘要：A network controller design and dynamic scheduling method based on switched principle is proposed for networked control systems with limited channel resource and quantizer. Considering the influence of medium access constraints, a communication constrained networked control system is transformed into a non-uniformly sampled switched system with multiple subsystems by using the switching scheduling matrix. By using Lyapunov stability theory to derive sufficient conditions for robust stabilization of the system, the design can meet the arbitrary switching stable robust controller and optimal dynamic scheduler. Finally, a simulation example is given to illustrate the effectiveness of the proposed method.关键词：communication resource constraints;switched systems;networked control systems;robust control;non-uniformly sampled128|197|6更新时间：2025-07-16
- 摘要：The rise of Bring Your Own Device (BYOD) now poses new challenges (the internal undefended causes the citadel to break through from within) to the concept of traditional boundary-based intranet protection. Based on the idea of isolation and dynamic, this paper designs and implements a Software-defined Intranet Dynamic Defense system (SIDD) to harass cyber kill chain. We allocate virtual IP address space for intranet terminals to hide the real IP address, meanwhile, combine the maneuvering of IP and path to achieve more comprehensive protection. Our experiments indicate that this method can significantly reduce the availability of network reconnaissance, block the network eavesdropping, and increase the difficulties of attacker's real-time attack without affecting network applications.关键词：intranet defense;software-defined network;IP maneuvering;path maneuvering170|271|4更新时间：2025-07-16
- 摘要：In this paper, a microblog user community detection algorithm via tag mean partition distance and social structure is proposed. Firstly, through the concept of information theory and distance, a community pre-partition algorithm based on the mean partition distance of core tags is established. Furthermore, a structure attribute vector is defined according to the user's following and follower relationships, based on which the user structure dissimilarity is calculated. Then, the comprehensive division dissimilarity is derived by adjusting the weight of mean distance of core tag and user structure dissimilarity. Finally, the subgroup corresponding to the tag with the lowest comprehensive division dissimilarity degree is considered as a new community for one iteration. Experiments show that the proposed method is effective and has practical significance.109|253|4更新时间：2025-07-16
- 摘要：To reduce the effect of the common source line noise in read operation of NAND Flash Memory, a page buffer circuit which can realize the coarse/fine read operation is proposed and a C/F read algorithm suitable for the page buffer circuit is introduced and implemented which can reduce the common source line noise significantly. There are two sub-read operations in the algorithm, the purpose of the first sub-read operation is to distinguish the cells with lower threshold voltage and mark them in page buffer circuit. These cells are no longer sensed in the second sub-read operation. As a result, the threshold voltage shift caused by the common source line noise is suppressed. The circuit simulation results show that the page buffer structure which supports the C/F read algorithm can reduce the shift of the threshold distribution more than 495.6mV and the read accuracy of NAND Flash Memory is greatly improved.关键词：NAND flash memory;multi-level cell;page buffer;coarse/fine read algorithm;read reliability101|290|1更新时间：2025-07-16
- 摘要：The existing recommendation systems typically employ explicit feedbacks, such as ratings and reviews, to achieve personalized recommendations. However, since the explicit feedbacks are hard to obtain in practice or have poor quality, their applications in the recommendation field are limited. In contrast, implicit feedbacks such as click behaviors and browsing histories are widely available in reality. A game recommendation method based on implicit feedbacks is presented, to provide the personalized game recommendation for game players. This method integrates the time-based implicit feedbacks, such as the times and duration of user operations, and constructs the player's preference model based on the pseudo rating. Meanwhile, it gives the personalized game recommendation by the improved SVD + + (Singular Value Decomposition + +) algorithm. The extensive results of the experiment based on the real data set show that the proposed method has the higher precision and recall.关键词：recommendation system;implicit feedback;game recommendation;pseudo rating;singular value decomposition + + (SVD + +)349|516|6更新时间：2025-07-16
- 摘要：In order to overcome low precision and premature convergence of firefly algorithm, this paper proposes a new method, called firefly algorithm with deep learning. First, firefly algorithm selects a particle to learn according to the random attraction model; second, the method constructs a general center particle based on the best historical position; third, the particle leads the evolution of the population after a certain times of one-dimensional deep learning. Experiments show that the deep learning strategy and the number of deep learning of particles play an important role in optimizing the performance of the algorithm. The experimental results of 12 benchmark functions demonstrate that the comprehensive optimization performance of the proposed algorithm outperforms eight other recently firefly algorithm variants.关键词：global optimization;random attraction model;general center particle;deep learning;firefly algorithm752|560|17更新时间：2025-07-16
- 摘要：In order to improve the performance of multi-class semi-supervised classification, a new multi-class Co-Forest algorithm named DSM-Co-Forest is proposed on the basis of D-S evidence theory. First, through MVM mode, the multi-labeled data set is randomly split into multiple binary-class data set to train the base classifiers; then, these base classifiers are used to pick out the high reliability samples from the unlabeled data set by using the evidence combination algorithm; finally, adds these selected samples to the original training set to iteratively update the base classifiers so as to improve the overall performance of the multi-class classifier. Through comparing with other semi-supervised classification algorithms on several public data sets, the feasibility and validity of the proposed algorithm are verified.关键词：semi-supervised learning;multi-class classification;evidence theory;co-forest201|274|2更新时间：2025-07-16
- 摘要：In order to achieve the expected fault detection capability for the multi-parity based fault detection scheme of AES S-box, a parameter calculation model was proposed to determine the total number of predicted parities according to the expected fault coverage. Two multi-parity based fault detection schemes which divided S-box based on redundant GF arithmetic into multiple blocks were designed on the basis of that number calculated by the model. The formulas for predicting the parity of each block was derived and optimized, and the polynomial coefficients and the mapping matrices were found by exhaustive search to get the optimum circuit. The simulation results show that the fault coverage of the two fault detection schemes is both about 97% for the random multiple faults which verifies the effectiveness of the parameter calculation model. The fault coverage of the two schemes for the burst faults are 61.8% and 76.3%, respectively, which are better than most fault detection schemes in existing works. Synthesis results show that the area-delay products of the two S-box circuits with fault detection capability are smallest compared to their counterparts with similar fault detection capabilities in existing literatures.关键词：advanced encryption standard (AES);S-box;composite fields;fault detection129|249|0更新时间：2025-07-16
- 摘要：This paper changes the assumption that samples are independent and identically distributed to that samples are uniformly ergodic Markov chains, which make it convenient for us to study the generalization performance of the imbalanced data classification algorithm, and SVM imbalanced data classification algorithm based on Markov sampling, EDSVM imbalanced data classification algorithm based on Markov sampling and SVM-WKNN imbalanced data classification algorithm based on Markov sampling are proposed. The numerical experiments of ten actual imbalanced datasets in the UCI database show that the misclassification rate of the above algorithm based on Markov sampling is lower than that of the corresponding algorithm based on random sampling, and the above three algorithms, SVM-WKNN imbalanced data classification algorithm based on Markov sampling has the best generalization performance.关键词：Markov sampling;support vector machine;k-nearest neighbor;imbalanced data266|242|2更新时间：2025-07-16
- 摘要：Multiple tags collision problem severely impairs identification performance of RFID systems. Anti-collision algorithms based on query tree have been widely applied in various RFID scenarios. In this paper, we analyze the performance and deficiency of mainstream query tree based algorithms. And then, a time efficient anti-collision algorithm based on query tree is proposed to enhance the identification efficiency. Specifically, the dual prefixes matching method is implemented based on the conventional query tree identification model, which can significantly remove idle slots. Moreover, the proposed method can also make extensive use of collision slots to improve the identification efficiency. Both theoretical and simulation results indicate that the proposed algorithm outperforms the existing query tree based algorithms.关键词：radio frequency identification (RFID);anti-collision;query tree (QT);time efficiency259|210|1更新时间：2025-07-16
- 摘要：Probabilistic routing algorithm is a common routing algorithm in opportunistic networks, and its TTL will directly affect the routing performance. Firstly, in the paper we uses Markov chain model to evaluate the transmission rate and the transmission delay of probabilistic routing. It can not only calculate the transmission delay for a message from a source node to a destination node, but also can predict the shortest TTL in a given transmission rate, which can provide theoretical guidance for the setting of TTL. Secondly, this prediction model can delete the messages which cannot be relayed to destination nodes to reduce unnecessary forwarding. Therefore, The model can be used to save the network resources maximally. Finally, we experimentally evaluate our model on two real data set, and demonstrate that it can provide a powerful reference for the setting of TTL values accurately in probabilistic routing.关键词：opportunistic networks;probability routing algorithm;prediction model;transmission rate;transmission delay106|186|0更新时间：2025-07-16
- 摘要：Inspired by Gestalt theory in psychology, we proposes a saliency detection method with multi-layer contour-region characteristic by using the complementary between contour cue and appearance cue, to address the problem that object is indiscoverable in the clutter scene, Firstly, after the image super-pixel segmentation, two kinds of appearance features are extracted respectively, including global appearance cue based on color histogram and local contrast cues based on the regional neighborhood relations. Secondly, in order to solve the object confusion caused by small difference in the appearance, we extract object closure feature to describe the saliency from object contour. Finally, we introduce multi-scale segmentation into our model to enhance the robustness for the diversity of object size, and use the support vector machine to optimize the fusion weights of contour-region cues. Experiments on ASD, MSRA10K, SED2 datasets show that, compared to other state-of-the-art methods, our model can improve the recall and precision measure due to the introduction of contour closure characteristic.关键词：saliency detection;contour closure;multi-layer fusion;appearance saliency;complementary105|192|3更新时间：2025-07-16
- 摘要：For the key components of the large reciprocating high pressure diaphragm pump, the wear breakdown of one way valve usually suffers from strong noise pollution and it is difficult to detect the fault. Starting with the analysis of the vibration signal of the check valve, a method of single directional valve fault diagnosis with the correlation coefficient SVD enhanced random resonance is proposed. In this method, the singular value decomposition (SVD) of the check valve vibration signal with noise is first carried out, then the component signal which contains the most information of the fault features is selected by the correlation coefficient method, and then input into the stochastic resonance system, the purpose of detecting the wear breakdown fault of the check valve under the strong noise background is achieved. The simulation results show that the proposed method solves the problem of difficult fault feature extraction under the strong noise background, and the measured data show that the method can effectively detect the wear breakdown fault of the check valve.关键词：check valve;correlation coefficient;singular value decomposition (SVD);stochastic resonance;strong noise189|301|6更新时间：2025-07-16
- 摘要：For sound event detection under various background noises at low SNR, this paper proposes a method that mixes the background noises with sound events into noisy samples to train classifiers. In the pre-processing stage, we use a voting method based on 2th to 6th intrinsic mode functions (IMFs) that generated from empirical mode decomposition (EMD), to detect the endpoint of sound events and estimate the SNR. Then subband power distribution (SPD) is used to extract features from audio data. Finally, we mix the background noise and all the sound event samples in the sound event database according to the estimated SNR, and then extract the noisy samples features to train multi-random forests (M-RF) for the detection of the sound events in low SNR environment. The experiment proves that the proposed method has the ability to recognize sound events in various acoustic scenes at low SNR, and can remain an average accuracy rate of 67.1% at-5dB.关键词：sound event detection;signal-to-noise ratio (SNR);empirical mode decomposition;subband power distribution;random forests182|235|3更新时间：2025-07-16
- 摘要：We propose a new model called smooth support vector machine with similarity-based feature transformation and fuzzy C-means (FCM) clustering (SFT-SSVM-FCM). When the similarity-based feature transformation technique is applied, Mercer's conditions are no longer required for kernel functions, thus broadening the range of usable kernel functions. We also incorporate the Fuzzy-C means clustering technique to divide a whole dataset into several clusters each of which is used to perform SSVM with similarity-based feature transformation. The experimental results indicate that the proposed model has better performance compared with the conventional SVM and SSVM model as well as some variants in terms of classification accuracy and training time.关键词：smooth support vector machine;fuzzy C-means (FCM);similarity;feature transformation328|320|2更新时间：2025-07-16
- 摘要：In order to improve the conventional support vector domain description (C-SVDD) algorithm's classification performance under unbalanced datasets, a novel maximum soft margin support vector domain descriptionalgorithm based on density sensitivity (DSMSM-SVDD) is presented. The relative density informationof the majority samples is introduced to reflect the impact of original training sample's space distribution on the optimal interface, by adding the maximum soft margin regularization term in the objective function, the classification boundary of the C-SVDD algorithm is shifted tominority classes, and consequently the classification performance of the proposed algorithm is significantly improved. Firstly, the relative density of each majority sample is calculated to reflect the importance of the training samples, and then the obtained training samples with relative density are input into the proposed DSMSM-SVDD algorithm to implement the classificationtask. In the experiments, the relationship of the parameters and the influence of the parameters on classification performance are investigated. Finally, the comparison results with C-SVDD algorithm demonstrate that the proposed algorithm is superior to the C-SVDD algorithm in the case of unbalanced data.关键词：support vector domain description;unbalanced datasets;relative density86|164|4更新时间：2025-07-16
- 摘要：In order to effectively recover the occlusion, this paper presents an iterative quadratic programming method for occlusion recovery. Based on the characteristic that the projections of the row vector and the column vector of image matrix to the orthogonal complementary subspace spanned by image matrix are zero vectors, the row and the column residual objective functions are respectively defined. At the same time, the occlusion positions are respectively sorted according to the row and the column order, whichcan be denoted by a transformation matrix. Based on the transformation matrix, a united residual objective function which is quadratic is obtained from the row and the column ones. The method has the advantages that both the row and the column constraints are simultaneously considered and the solution of occlusion is transformed to iterative solution a quadratic programming. The experimental results show that the method has fast convergence speed and high precision.关键词：occlusion recovery;quadratic programming;projection167|164|0更新时间：2025-07-16
- 摘要：A novel combination rule for evidence is proposed to deal with the "veto problem" in Dempster rule and the subjectively assigning the conflict information in the existing modified methods. This novel method combines the defined complementary evidence directly instead of using the pure Dempster multiplicative strategy, which successfully solves the "veto problem". It transfers the conflict to the evidence weight which can be processed directly with the novel combination rule instead of assigning the conflict subjectively. It is regarded as a generalized additive aggregation operator, which not only satisfies the commutative law and associative law, but also can combine the single focus elements directly and compound focus elements based on TBM. With the help of a multi-sensor fusion recognition example, the superiority of the proposed combination rule is illustrated and compared in detail.关键词：evidence theory;combination rule;complementary evidence;conflict;the transferable belief model (TBM)137|214|2更新时间：2025-07-16
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Low-Complexity Soft-Output Signal Detection Based on Kaczmarz Method for Uplink Massive MIMO Systems
摘要：For massive MIMO system uplink, conventional minimum mean square error (MMSE) linear detection algorithm can achieve nearly optimal performance, but it involves complicated matrix inversion. A low-complexity detection algorithm based on Kaczmarz method is proposed in this paper, which can circumvent the matrix inverse operation and hence reduce the complexity from O (K3) to O (K2). Meanwhile, an optimal relaxation parameter is introduced to further accelerate the algorithm convergence, and two approximate methods of log-likelihood ratios (LLR) estimation for channel decoding are given as well. Simulation results verify that the proposed algorithm outperforms the Neumann series expansion algorithms on both bit error ratio (BER) and computational complexity. It converges rapidly and achieves its performance quite close to that of the MMSE algorithm with only a small number of iterations.关键词：massive MIMO;low-complicity;Kaczmarz;relaxation parameter;soft decision118|270|1更新时间：2025-07-16 - 摘要：The increasingly complex radio frequency electromagnetic environment seriously interferes the normal operation of GNSS. Spatial adaptive processing using multi antenna can effectively suppress the interference, but the spatial adaptive processing algorithm may introduce the satellite signal carrier phase measurement error. In addition, nonideal factors of the array will also introduce errors, which is intolerable for high-precision measurement systems. Therefore, in this paper, the influence of the frequently-used spatial adaptive processing algorithm on the carrier phase measurement is analyzed theoretically. Furthermore, a blind adaptive processing algorithm does not need the array manifold information is proposed, which can effectively increase the antenna gain in the direction of the desired satellite while forming reception nulls towards the interference, meanwhile, the introduced carrier phase measurement error is reduced effectively, referred to as two step De-spread Re-spread (DR) algorithm. The core idea of the proposed algorithm is to add a high accuracy frequency estimation modular to the DR algorithm, the fine carrier frequency estimation is then used to construct the local reference signal, so as to ensure the error between the steering vector obtained beamforming weight vector and the satellite signal as small as possible.关键词：global navigation satellite system (GNSS);high precision measurement;spatial adaptive interference suppression;de-spread re-spread (DR)237|305|6更新时间：2025-07-16
- 摘要：In Empirical mode decomposition (EMD) method, the upper and lower envelopes fitted by cubic spline interpolation (CSI) may often occur undershoots phenomenon and mode mixing problem. The Piecewise Cubic Hermite interpolation (PCHI) is not flexible enough. A new quadratic Hermite interpolation algorithm for EMD envelope based on PSO is proposed. The algorithm can adjust the shape of the curve with the shape parameters, and find the optimal smooth envelope by PSO. The experimental result of simulation signal and nonstationary signals show that, the proposed algorithm can effectively overcome the undershoot problem caused by the traditional method, improve the modal aliasing effect, the IO and IEC of the decentralized IMF components are superior to the traditional method.关键词：particle swarm optimization;empirical mode decomposition;rational hermite interpolation;envelopes fitting201|219|1更新时间：2025-07-16
- 摘要：The surface potential analytical solution is derived by Poisson equation and the boundary condition for symmetrical triple-material (TM) double-gate (DG) strained-Si (s-Si) MOSFETs. Two-dimensional analytical models of subthreshold current and subthreshold slope are proposed from subthreshold current density equation based on the diffusion-drift theory. Effects of device parameters on subthreshold characteristics have been discussed and the physical mechanism has been explained. The parameters include channel length, work function difference、Ge mole fraction, permittivity of gate dielectric, strained Si film thickness, high-k layer thickness and channel doping concentration. The improvement of the subthreshold performance has been studied, which provides significant guidance to optimize the device parameters. The analytical models agree well with simulation using DESSIS.关键词：subthreshold current;subthreshold slope;triple-material double-gate;strained-Si140|187|1更新时间：2025-07-16
- 摘要：In view of the low recommendation accuracy due to the sparseness of data, and the lack of diversity in traditional service recommendation algorithms, personalized service recommendation method based on random walking and diversified graph ranking (PRWDR) is proposed. On the basis of analyzing the sparseness of direct similarity relationships, a weighted random walk model is proposed, which can excavate more similarity relationships by random walk on the user network. The QoS value of services is predicted based on all similar users, and then the service graph model construction method is presented to filter those services with low performance. By using the greedy algorithm, the optimal node collection selection strategy is proposed to obtain the service recommendation list with both accuracy and diversity. By testing the algorithm on the public dataset and also comparing with several classic algorithms, the validity of PRWDR is verified.关键词：service recommendation;data sparseness;diversity;random walk model241|285|4更新时间：2025-07-16
- 摘要：In many signal filtering applications, the requirement on the magnitude response of the filter is higher than that on the phase response. The design of magnitude-response constrained finite impulse response (FIR) filters was considered and a minimax weighted phase error design method was proposed. Replacing the nonconvex magnitude error constraint with an elliptic error constraint makes the design problem a convex one. Incorporating with a bisection technique, a design algorithm was firstly obtained for the case with a preset phase-error weight. Using this algorithm as the iteration core, an iterative reweighted minimax phase error design algorithm was constructed, where the phase-error weight is not fixed but updated using a modified envelop of the group-delay error function. After the iterative algorithm converges, the resultant filter has a near equiripple group-delay error and a reduced maximum group-delay error. Experiments demonstrate that the proposed method has obtained smaller passband phase error and group-delay error than the existing phase-error constrained minimax magnitude error method.关键词：FIR filter;magnitude response;phase response;bisection method;elliptic error constraint;iterative reweighting technique141|225|5更新时间：2025-07-16
- 摘要：With the proposing of Global Industry 4.0, the requirements for the embedded system become higher in industrial control, aerospace and other fields which have strict requirements for real-time and also need the supports of the application-rich general-purpose operating system. In view of this situation, Academia and Industry fields proposed a solution called dual operating system that a real-time operating system and a general-purpose operating system run at the same time. This paper summarizes the current states of dual operating system for embedded platform both at home and abroad, discusses and analyzes various implementation technologies, lists the typical application and main application fields of dual operating system for embedded platform, and finally summarizes the research trend of dual operating system for embedded platform.关键词：dual operating system;embedded operating system;real-time;virtualization;dual-core336|584|2更新时间：2025-07-16
- 摘要：The active microwave cold noise source technology is introduced. The working principle and key technology of active microwave cold noise source are explained. A design method of active microwave cold noise source is proposed, and the influence of the key steps in the design process on the performance of the noise source is analyzed. Based on these theories, the C band active microwave cold noise source device was developed by the pHEMT type field effect transistor. In the end, the performance of the device is tested and analyzed.关键词：active cold noise source;radiometer;Calibration;HEMT165|195|1更新时间：2025-07-16
- 摘要：With the development of the distributed technology, field-bus technology and Web technology, the online monitoring information system of transformer substation has evolved from the original decentralized system to the present centralized system. But due to the different types of online monitoring units, and time asynchronous to carry out the monitoring, there is no unified planning, and lack of coordination in each transformer substation. The present system does not play its due role. Through the hierarchical structure design for online monitoring information system, constructing the integrated information network, unified processing data from monitoring acquisition units. This system integrates the data information and assesses the equipment condition, and reports the processed data in a unified interface. It realizes the promotion of technical support and technical service level in power service company, and improves the intelligence level of the transformer substation. This system can provide basic online monitoring and status evaluation related applications for provincial companies and urban power bureau.关键词：transformer substation;online monitoring;hierarchical design;information system148|169|2更新时间：2025-07-16
- 摘要：To solve the problem that it is difficult to select the sliding coefficient, the sliding mode control theory was used toestablish the phase-variable model of the single-phase full-bridge inverter with sliding mode control. According to the constraint control principleand the sliding-mode's existence conditions themathematical relationship among the sliding domain, sliding coefficient and load resistance are derived. Then, the papermade ananalysis of the relationship between the sliding domain boundary and sliding coefficient, load resistance, load step amplitude, and put forward the basic principle of choosing the sliding coefficient. Based on the inverter load-step system trajectories, combined the sliding domain right boundary conditions with the inverter desired dynamic, the design method for the sliding mode controller with the hysteresis modulation is proposed. In the simulation experiment the sliding mode controller wasdesigned by this method, the results show that the design method is correct and effective. This method is simple and easy to operate, and is a good theoretical reference value and engineering value.关键词：phase variable model;sliding mode control (SMC);sliding domain;sliding coefficient;inverter145|191|0更新时间：2025-07-16
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