SPECTRAL ANALYSIS OF SOME INDEPENDENCES OF MULTIPLE-VALUED LOGICAL FUNCTIONS ON THEIR VARIABLES

There are many kinds of special relationships between multiple-valued logical func-tions and their variables, and they are difficult to be judged from their expressions. In thispaper, some sufficient and necessary conditions of the independence and statistical independenceof multiple-valued logical functions on their variables are given. Some conditions of algebraicindependence of multiple-valued logical functions on some of their variables and the way to de-generate a function to the greatest extent are proposed, and some applications of these resultsare indicated. All the results are studied by using Chrestenson spectral techniques.

CIRCUIT TESTABLE DESIGN AND UNIVERSAL TEST SETS FOR MULTIPLE-VALUED LOGIC FUNCTIONS

The circuit testable realizations of multiple-valued functions are studied in this letter. First of all,it is shown that one vector detects all skew faults in multiplication modulo circuits or in addi-tion modulo circuits,and n+1 vectors detect all skew faults in the circuit realization of multiple-valued functions with n inputs. Secondly,min(max) bridging fault test sets with n+2 vectors are pre-sented for the circuit realizations of multiple-valued logic functions. Finally,a tree structure is used instead of cascade structure to reduce the delay in the circuit realization,it is shown that three vec-tors are sufficient to detect all single stuck-at faults in the tree structure realization of multiple-valued logic functions.

Analysis of a Class of Logical Functions over Galois and Z_m Rings

In this paper, the author analyzed some cryptographic properties of a class of logical functions, f(x,y)=(q(x),...,q(x))·y+h(x),over Galois rings and residue rings, presented the relationship between the character spectrum of f(x,y) and the character speetrum of q(x),h(x) and the relationship between the cryptographic properties of f(x,y) and the cryptographic properties of h(x).

FAULT DETECTION FOR MULTIPLE-VALUED LOGIC CIRCUITS WITH FANOUT-FREE

The single fault and multiple fault detections for multiple-valued logic circuits are studied in this paper. Firstly, it is shown that the cardinality of optimal single fault test set for fanout-free m-valued circuits with n primary inputs is not more than n + 1, for linear tree circuits is two, and for multiplication modulo circuits is two if n is an odd number or if n is an even number and m ＞ 3, where the optimal test set of a circuit has minimal number of test vectors. Secondly,it is indicated that the cardinality of optimal multiple fault test set for linear tree circuits with n primary inputs is 1 + [n/(m - 1)], for multiplication modulo circuits is n+ 1, for fanout-free circuits that consist of 2-input linear tree circuits and 2-input multiplication modulo circuits is not greater than n+ 1, where [x] denotes the smallest integer greater than or equal to x. Finally,the single fault location approaches of linear tree circuits and multiplication modulo circuits are presented, and all faults in the two types of circuits can be located by using a test set with n + 1 vectors.

HAAR EXPANSIONS OF A CLASS OF FRACTAL INTERPOLATION FUNCTIONS AND THEIR LOGICAL DERIVATIVES

In this paper,we study a special class of fractal interpolation functions,and give their Haar-wavelet expansions.On the basis of the expansions,we investigate the H(o|¨)lder smoothness of such functions and their logical derivatives of order α.

LOGICAL SYNTHESIS OF MOLTIVALUED SYMMETRIC FUNCTION BASED ON BINARY FULL ADDERS

This paper discusses the definition and properties of multivalued symmetric functions, points out that a multivalued symmetric function can be decomposed according to the value of the function j. The subfunction Lj corresponding to j must be a symmetric function, and it may be expressed as the sum of products form of degenerated multivalued fundamental symmetric functions. Based on this consideration, the circuit realization for the multivalued symmetric functions based on full adders is proposed.

Spectral Characteristics of the Best Affine Approach of Multi-Output m-Valued Logical Functions

This paper discusses the best affine approach （BAA） of multi-output m-valued logical functions. First, it gives the spectra of rate of accordance between multi-output m-valued logical functions and their affine functions, then analyzes the BAA of multi-output m-valued logical functions and finally gives the spectral characteristics of BAA of multi-output m-valued logical functions.

Design of AB^2 in Galois Fields Based on Multiple-Valued Logic

A new AB^2 operation in Galois Field GF(24)is presented and its systolic realization based on multiple-valued logic(MVL)is proposed.The systolic structure of the operation employs multiple-valued current mode(MVCM)by using dynamic source-coupled logic(SCL)to reduce the transistor and wire counts,and the initial delay.The performance is evaluated by HSPICE simulation with 0.18.μm CMOS technology.A comparison is conducted between our proposed implementation and those reported in the literature.The transistor counts,the wire counts and the initial delay in our MVL design show savings of about 23%,45%,and 72%,in comparison with the corresponding binary CMOS implementation.The systolic architecture proposed is simple,regular,and modular,well suited for very large scale integration(VLSI)implementation.The combination of MVCM circuits and relevant algorithms based on MVL seems to be a potential solution for high performance arithmetic operations in GF(2^k).

Ingredients-based Methodology and Fuzzy Logic Combined Short-Duration Heavy Rainfall Short-Range Forecasting:An Improved Scheme

Short-duration heavy rainfall(SHR),as delineated by the National Meteorological Center of the China Me-teorological Administration,is characterized by hourly rainfall amounts no less than 20.0 mm.SHR is one of the most common convective weather phenomena that can cause severe damage.Short-range forecasting of SHR is an important part of operational severe weather prediction.In the present study,an improved objective SHR forecasting scheme was developed by adopting the ingredients-based methodology and using the fuzzy logic approach.The 1.0°×1.0°National Centers for Environmental Prediction(NCEP)final analysis data and the ordinary rainfall(0.1-19.9 mm h-1)and SHR observational data from 411 stations were used in the improved scheme.The best lifted index,the total precipitable water,the 925 hPa specific humidity(Q 925),and the 925 hPa divergence(DIV 925)were selected as predictors based on objective analysis.Continuously distributed membership functions of predictors were obtained based on relative frequency analysis.The weights of predictors were also objectively determined.Experiments with a typhoon SHR case and a spring SHR case show that the main possible areas could be captured by the improved scheme.Verification of SHR forecasts within 96 hours with NCEP global forecasts 1.0°×1.0°data initiated at 08:00 Beijing Time during the warm seasons in 2015 show the results were improved from both deterministic and probabilistic perspectives.This study provides an objectively feasible choice for short-range guidance forecasts of SHR.The scheme can be applied to other convective phenomena.

Logical Function Decomposition Method for Synthesis of Digital Logical System Implemented with Programmable Logic Devices (PLD)

The paper consists in the use of some logical functions decomposition algorithms with application in the implementation of classical circuits like SSI, MSI and PLD. The decomposition methods use the Boolean matrix calculation. It is calculated the implementation costs emphasizing the most economical solutions. One important aspect of serial decomposition is the task of selecting “best candidate” variables for the G function. Decomposition is essentially a process of substituting two or more input variables with a lesser number of new variables. This substitutes results in the reduction of the number of rows in the truth table. Hence, we look for variables which are most likely to reduce the number of rows in the truth table as a result of decomposition. Let us consider an input variable purposely avoiding all inter-relationships among the input variables. The only available parameter to evaluate its activity is the number of “l”s or “O”s that it has in the truth table. If the variable has only “1” s or “0” s, it is the “best candidate” for decomposition, as it is practically redundant.

Logical-Structure Modeling for Conceptual Design

Based on the definition of a logic structure feature to relate logically functional requirements to geometric representation independent upon detailed geometric representation, this paper presents an idea of logical structure modeling for computer aided conceptual design and makes attempt to establish a representation formalism of logic structure modeling. The definition and representation of logical structure feature are given and an assembly module definition for supporting top down conceptual design is also proposed. The proposed scheme contributes to several aspects of conceptual design research, especially to provide elementarily a formal methodology for computer aided conceptual design system development and operation.

Fuzzy logic controller design with unevenly-distributed membership function for high performance chamber cooling system

Fuzzy logic controller adopting unevenly-distributed membership function was presented with the purpose of enhancing performance of the temperature control precision and robustness for the chamber cooling system.Histogram equalization and noise detection were performed to modify the evenly-distributed membership functions of error and error change rate into unevenly-distributed membership functions.Then,the experimental results with evenly and unevenly distributed membership functions were compared under the same outside environment conditions.The experimental results show that the steady-state error is reduced around 40% and the noise disturbance is rejected successfully even though noise range is 60% of the control precision range.The control precision is improved by reducing the steady-state error and the robustness is enhanced by rejecting noise disturbance through the fuzzy logic controller with unevenly-distributed membership function.Moreover,the system energy efficiency and lifetime of electronic expansion valve(EEV) installed in chamber cooling system are improved by adopting the unevenly-distributed membership function.

Uncertainties in estimation of extrapolated annual occurence rate of earthquakes using logical tree

he logical tree methods are used for evaluate quantitatively relationship between frequency and magnitude, and deduce uncertainties of annual occurrence rate of earthquakes in the periods of lower magnitude earthquake. The uncertainties include deviations from the self-similarity of frequency-magnitude relations, different fitting methods, different methods obtained the annual occurrence rate, magnitude step used in fitting, start magnitude, error of magnitude and so on. Taking Xianshuihe River source zone as an example, we analyze uncertainties of occurrence rate of earthquakes M4, which is needed in risk evaluation extrapolating from frequency-magnitude relations of stronger earthquakes. The annual occurrence rate of M4 is usually required for seismic hazard assessment.The sensitivity analysis and examinations indicate that, in the same frequencymagnitude relations fitting method, the most sensitive factor is annual occurrence rate, the second is magnitude step and the following is start magnitude. Effect of magnitude error is rather small.Procedure of estimating the uncertainties is as follows:①Establishing a logical tree described uncertainties in frequencymagnitude relations by available data and knowledge about studied region.② Calculating frequencymagnitude relations for each end branches. ③ Examining sensitivities of each uncertainty factors, amending structure of logical tree and adjusting original weights. ④ Recalculating frequencymagnitude relations of end branches and complementary cumulative distribution function (CCDF) in each magnitude intervals.⑤ Obtaining an annual occurrence rate of M4 earthquakes under given fractiles.Taking fractiles as 20% and 80%, annual occurrence rate of M 4 events in Xianshuihe seismic zone is 0.643 0. The annual occurrence rate is 0.631 8 under fractiles of 50%, which is very close to that under fractiles 20% and 80%.

CONCEPTUAL MODELING BASED ON LOGICAL EXPRESSION AND EVOLVEMENT

Aiming at the problem of abstract and polytype information modeling in product conceptual design, a method of conceptual modeling based on logical expression and evolvement is presented. Based on the logic expressions of the product conceptual design information, a fimction/logic/strucmre mapping model is set up. First, the fimction semantics is transformed into logical expressions through fimction/logic mapping. Second, the methods of logical evolvement are utilized to describe the fimction analysis, fimction/strucmre mapping and structure combination. Last, the logical structure scheme is transformed into geometrical sketch through logic/structure mapping. The conceptual design information and modeling process are described uniformly with logical methods in the model, and an effective method for computer aided conceptual design based on the model is implemented.

FAULT DETECTION TEST SET FOR TESTABLE REALIZATIONS OF LOGIC FUNCTIONS WITH ESOP EXPRESSIONS

The circuit testable realization and its fault detection for logic functions with ESOP （EXOR-Sum-Of-Products） expressions are studied. First of all, for the testable realization by using XOR gate cascade, a test set with 2n ＋ m ＋ 1 vectors for the detections of AND bridging faults and a test set with 2n ＋ m vectors for the detections of OR bridging faults are presented. Secondly, for the testable realization by using ）（OR gate tree, a test set with 2n ＋ m vectors for the detections of AND bridging faults and a test set with 3n ＋ m ＋ 1 vectors for the detections of OR bridging faults are presented. Finally, a single fault test set with n ＋ 5 vectors for the XOR gate tree realization is presented. Where n is the number of input variables and m is the number of product terms in a logic function.

Evolution Performance of Symbolic Radial Basis Function Neural Network by Using Evolutionary Algorithms

Radial Basis Function Neural Network(RBFNN)ensembles have long suffered from non-efficient training,where incorrect parameter settings can be computationally disastrous.This paper examines different evolutionary algorithms for training the Symbolic Radial Basis Function Neural Network(SRBFNN)through the behavior’s integration of satisfiability programming.Inspired by evolutionary algorithms,which can iteratively find the nearoptimal solution,different Evolutionary Algorithms(EAs)were designed to optimize the producer output weight of the SRBFNN that corresponds to the embedded logic programming 2Satisfiability representation(SRBFNN-2SAT).The SRBFNN’s objective function that corresponds to Satisfiability logic programming can be minimized by different algorithms,including Genetic Algorithm(GA),Evolution Strategy Algorithm(ES),Differential Evolution Algorithm(DE),and Evolutionary Programming Algorithm(EP).Each of these methods is presented in the steps in the flowchart form which can be used for its straightforward implementation in any programming language.With the use of SRBFNN-2SAT,a training method based on these algorithms has been presented,then training has been compared among algorithms,which were applied in Microsoft Visual C++software using multiple metrics of performance,including Mean Absolute Relative Error(MARE),Root Mean Square Error(RMSE),Mean Absolute Percentage Error(MAPE),Mean Bias Error(MBE),Systematic Error(SD),Schwarz Bayesian Criterion(SBC),and Central Process Unit time(CPU time).Based on the results,the EP algorithm achieved a higher training rate and simple structure compared with the rest of the algorithms.It has been confirmed that the EP algorithm is quite effective in training and obtaining the best output weight,accompanied by the slightest iteration error,which minimizes the objective function of SRBFNN-2SAT.

教育数字化推动教育强国建设的功能逻辑与实践进路

教育与数字技术的融合引领了未来教育发展的新趋势,为人类教育带来更广阔的发展空间和美好愿景。在教育强国建设过程中,教育数字化展现出其独特的技术优势,它既是推动教育强国建设的重要基础和动能引擎,又能为教育强国建设提供根本保障。借助教育数字化的力量,形塑教育要素新样态、助推数字教育模式革新、赋能教育多元体系构建、促进数字教育生态重塑以及扩大数字教育国际影响力,是教育数字化赋能教育强国建设功能演进的内在逻辑。教育数字化有效推动教育强国建设,需要聚焦拔尖创新人才培养,提高教育数字化对教育强国建设的贡献指数;矫正主体认知抵牾,加强教育数字化对教育强国建设的多方协作;增强教育深层变革,释放教育数字化对教育强国建设的巨大潜能;创新教育技术体系,响应教育数字化对教育强国建设的内生需求;健全数字教育制度,保障教育数字化对教育强国建设的持续赋能,从而充分发挥教育数字化重要突破口的作用,整体推进教育高质量发展,助力教育强国建设。

基于改进型滑模变结构的永磁同步电机的无位置传感器矢量控制

针对传统滑模控制采用不连续的符号函数作为滑模面切换函数所引起的抖振问题,提出一种基于改进型滑模变结构的永磁同步电机的无位置传感器矢量控制方法,来削弱抖振,从而改善系统的动、静态性能。首先,设计了改进型滑模控制器和改进型滑模观测器的变结构控制系统。其次,采用连续的开关函数——双曲正切函数作为滑模面切换函数,并通过模糊逻辑控制对双曲正切函数的形状系数进行调整,减弱固定边界层厚度所引起的抖振。然后,运用李雅普诺夫第二定理证明所设计的控制系统的稳定性。最后,与其他方法相比,仿真结果证明了所提方法的可行性和有效性。

基于有限谓词追踪的民机系统需求一致性检查方法

针对民机安全关键系统在正向研发过程中,系统级需求的正确性难以在设计早期全部完成确认的问题,提出一种基于有限谓词追踪的功能需求一致性检查体系。首先,引入一阶逻辑中的谓词追踪,建立系统内部功能需求与交互功能需求形式化规约方法。其次,针对单条、多条需求内容正确性以及需求关系一致性,构建需求一致性检查形式化规约,开展需求自冲突、集冲突与需求关系一致性检验,并生成可解释的检查反例进行需求迭代。最后,以机载平视显示(head-up display,HUD)系统飞行信息符号生成与显示功能为例,验证该方法的正确性与有效性。研究结果表明,基于有限谓词追踪的功能需求一致性检查方法能够提高需求一致性检查效率、降低研发成本,为民机系统级需求确认提供支持。

科技情报机构的智库功能

[目的/意义]支撑决策是科技情报工作的重要使命,当前科技情报机构正积极探索发挥科技智库功能的转型路径。[方法/过程]本文采用文献调查、案例比较等方法,深入分析科技情报机构智库功能的基础条件、典型做法,结合工作实际总结发挥好智库功能的实践逻辑和实现路径。[结果/结论]本文原创提出做好支撑决策的情报研究工作可以遵循的实践逻辑:坚持“从零散转化为结构,从结构整合为系统,从系统升华到体系”的层次渐进认知,贯通“感知-监测-理解-分析-预判”的实践路径,循环迭代,贴近乃至契合决策咨询需求。