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Improving Linear Type Traits to Improve Production Sustainability and Longevity in Purebred Sahiwal Cattle
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作者 Ashutosh Dubey Sharad Mishra Vikas Khune Pavan K. Gupta Bhooshan K. Sahu Arvind K. Nandanwar 《Journal of Agricultural Science and Technology(A)》 2012年第5期636-639,共4页
In order to determine various traits which need to be improved for improving the productive life span and longevity, purebred Sahiwal cows available at bull mother experimental farm and cattle breeding farm located at... In order to determine various traits which need to be improved for improving the productive life span and longevity, purebred Sahiwal cows available at bull mother experimental farm and cattle breeding farm located at Veterinary College, Durg, Chhattisgarh, India were used. For present investigation, 17 linear type traits were measured, scaled and scored as per the guidelines of International Committee for Animal Recording (2001). The average score point (ASP) under 1-9 point scale score system along with respective observed group for different linear type traits were stature (6.88; taller), chest width (5.30; intermediate), body depth (4.11; intermediate), rump angle (4.27; intermediate), rump width (5.09; intermediate), rear leg set-side view (4.55; intermediate), rear leg set-rear view (5.95; intermediate), foot angle (5.66; intermediate), udder depth (5.71; intermediate), rear udder height (4.90; intermediate), udder balance (5.27; intermediate), udder cleft (3.75; intermediate), fore udder attachment (5.55; intermediate), teat length (3.54; intermediate), fore teat placement (5.33; intermediate), rear teat placement (6.37; intermediate) and teat thickness (2.76; narrow). For most of the traits, ASP which lies near midpoint (i.e. near five) is known to be ideal for dairy type cattle. Moreover, some traits also showed the presence of undesirable ASP. Hence, the traits such as body depth, rump angle, foot angle, udder depth, rear udder height, udder cleft, fore udder attachment, teat length, and teat thickness needs to be improved for improving the production sustainability and herd life of Sahiwal cattle. Thus, present investigation gives explicit clue to incorporate these conformation traits in selection program of this valuable germplasm commonly found in Southern part of Asia (India, Pakistan, Srilanka, etc.). 展开更多
关键词 SAHIWAL linear type traits production sustainability and longevity.
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Generalized Graph Ideals of Linear Type
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作者 M. La Barbiera P.L. Stagliano 《Algebra Colloquium》 SCIE CSCD 2017年第1期83-91,共9页
Let S = K[x1,..., xn; y1,..., ym] be the polynomial ring in two sets of variables over a field K. We investigate some classes of graph ideals of S, namely the generalized graph ideals, in order to classify ideals of l... Let S = K[x1,..., xn; y1,..., ym] be the polynomial ring in two sets of variables over a field K. We investigate some classes of graph ideals of S, namely the generalized graph ideals, in order to classify ideals of linear type. 展开更多
关键词 ideals of mixed products graph ideals ideals of linear type
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Puziwan Gold Deposit in Shanxi,China:A Special Linear Cryptoexplosive Breccia Type Gold Deposit 被引量:7
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作者 YAN Fengzeng 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2000年第3期554-558,共5页
The Puziwan gold deposit is a special linear cryptoexplosive breccia type deposit found in northeastern Shanxi, China, in recent years. The deposit is located in a secondary metallogenic belt of the most famous Au-Ag ... The Puziwan gold deposit is a special linear cryptoexplosive breccia type deposit found in northeastern Shanxi, China, in recent years. The deposit is located in a secondary metallogenic belt of the most famous Au-Ag polymetallic metallogenic belt along the north margin of the North China platform. The secondary metallogenic belt is a synmagmatic tension-shear fault-fracture belt of ENE linear trend. The Indosinian cryptoexplosive breccia body, quartz monzonitic porphyry (beschtauite breccia), quartz monzonite (243.7 Ma, K-Ar), Yanshanian granite-porphyry (105±6 Ma, Rb-Sr) and orebodies mostly occur as dykes or veins and short lenses along the structural fracture belt. The orebodies are emplaced in the fractured cryptoexplosive breccia body in the tectonomagmatic belt and their attitude is consistent with that of the breccia body. The orebodies have two types: one is shallow-seated thick and big ones, which are short-lenticular in plan and wedge-shaped in cross section, shallow buried, large in size and high-grade; the other is lean orebodies, which occur as parallel veins at depths. The ores are mainly of Au-Ag polymetallic sulphide-rich breccia type. Pyrite (limonite) is the dominant metallic mineral, with subordinate chal-copyrite, galena, sphalerite, tenantite, native gold, electrum, native silver and argentite. The gangue minerals consist mainly of quartz and plagioclase, with subordinate carbonate minerals, alunite chalcedony and kaolin. Kaolinization is the characteristic alteration type. Sulphide minerals contain abundant trace minerals such as Cu, Pb, Ag, Sb and Hg, while in the ores Ag, Cu, Pb, Zn, As and Sb are the best indicator element assemblage of Au. The δ34S(%o) values of the ores rane from ?3.2%o to 5.3%o, with average ?0.102%o. The δO H2O(%o) and δ(%o) values are in the ranges from ?3.1%o to 7.73%o and from ?64%o to ?90%o respectively. The Pb isotopic compositions of the rocks and ores in this region indicate that Pb comes from three tectonic sources—upper mantle, lower crust and orogenic belt. The inclusion homogenization temperature are in the ranges of 110 to 220°C and 230 to 310°C, which suggests that the deposit formed under meso-epithermal conditions. The ore-forming pressures range from 6 to 32 MPa and the depths are 230 to 1200 m. In view of the above, the Puziwan gold deposit is genetically ascribed to a high-sulphur (alunite-kaolin) meso-epithermal gold deposit related to subvolcanic rocks. This gold deposit formed during the Indosinian stage (245.9±0.3 Ma) and then was influenced by a thermal event in the Yanshanian stage (142.9±0.5 Ma). 展开更多
关键词 gold deposit linear cryproexplosive breccia type SHANXI
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Ultrasonic beam focusing characteristics of shear-vertical waves for contact-type linear phased array in solid 被引量:2
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作者 Yu-Xiang Dai Shou-Guo Yan Bi-Xing Zhang 《Chinese Physics B》 SCIE EI CAS CSCD 2020年第3期270-276,共7页
We investigate the beam focusing technology of shear-vertical(SV) waves for a contact-type linear phased array to overcome the shortcomings of conventional wedge transducer arrays. The numerical simulation reveals the... We investigate the beam focusing technology of shear-vertical(SV) waves for a contact-type linear phased array to overcome the shortcomings of conventional wedge transducer arrays. The numerical simulation reveals the transient excitation and propagation characteristics of SV waves. It is found that the element size plays an important role in determining the transient radiation directivity of SV waves. The transient beam focusing characteristics of SV waves for various array parameters are deeply studied. It is particularly interesting to see that smaller element width will provide the focused beam of SV waves with higher quality, while larger element width may result in erratic fluctuation of focusing energy around the focal point. There exists a specific range of inter-element spacing for optimum focusing performance. Moreover, good beam focusing performance of SV waves can be achieved only at high steering angles. 展开更多
关键词 beam focusing shear-vertical(SV)waves contact-type linear phased array SOLID
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Actuating mechanism and design of a T-type linear ultrasonic motor
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作者 刘英想 刘军考 +1 位作者 陈维山 石胜君 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2011年第2期43-46,共4页
To take advantage of merits of higher output-power and efficiency of bolt-clamped transducer,a T-type linear ultrasonic motor was proposed in this paper.The proposed motor contained a horizontal transducer and a verti... To take advantage of merits of higher output-power and efficiency of bolt-clamped transducer,a T-type linear ultrasonic motor was proposed in this paper.The proposed motor contained a horizontal transducer and a vertical transducer.The horizontal transducer included two exponential shape horns,and the vertical transducer contained one exponential shape horn.And the horns intersected at tip ends where a driving foot was located.The longitudinal vibrations of transducers were excited by the stretching vibration of PZT ceramics.Longitudinal vibrations were superimposed in the motor and generated elliptical trajectory at the driving foot.The actuating mechanism of the proposed motor was analyzed.The two working modals of the motor were gained with FEM.The resonant frequencies of two working modals were degenerated by adjusting the structural parameters.The motion trajectory of nodes on the driving foot was gained by transient analysis.The vibration amplitude of node on the driving foot indicates that the proposed motor has potential good output characteristics.The results verify the feasibility of the proposed design and provide instructions for the development of the new ultrasonic motor. 展开更多
关键词 ultrasonic motor linear T-type longitudinal transducer FEM
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Fully Nonlinear Boussinesq-Type Equations with Optimized Parameters for Water Wave Propagation
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作者 荆海晓 刘长根 +1 位作者 龙文 陶建华 《China Ocean Engineering》 SCIE EI CSCD 2015年第4期503-518,共16页
For simulating water wave propagation in coastal areas, various Boussinesq-type equations with improved properties in intermediate or deep water have been presented in the past several decades. How to choose proper Bo... For simulating water wave propagation in coastal areas, various Boussinesq-type equations with improved properties in intermediate or deep water have been presented in the past several decades. How to choose proper Boussinesq-type equations has been a practical problem for engineers. In this paper, approaches of improving the characteristics of the equations, i.e. linear dispersion, shoaling gradient and nonlinearity, are reviewed and the advantages and disadvantages of several different Boussinesq-type equations are compared for the applications of these Boussinesq-type equations in coastal engineering with relatively large sea areas. Then for improving the properties of Boussinesq-type equations, a new set of fully nonlinear Boussinseq-type equations with modified representative velocity are derived, which can be used for better linear dispersion and nonlinearity. Based on the method of minimizing the overall error in different ranges of applications, sets of parameters are determined with optimized linear dispersion, linear shoaling and nonlinearity, respectively. Finally, a test example is given for validating the results of this study. Both results show that the equations with optimized parameters display better characteristics than the ones obtained by matching with pad6 approximation. 展开更多
关键词 Boussinesq-type equations linear dispersion shoaling gradient NONlinearITY
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Lyapunov-type Inequalities For A System of Nonlinear Difference Equations
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作者 WEI Geng-ping 《Chinese Quarterly Journal of Mathematics》 2019年第1期88-98,共11页
This paper establishes several new Lyapunov-type inequalities for the system of nonlinear difference equations■,which extend/supplement and improve some related existing ones.
关键词 Lyapunov-type inequality linear difference system Nonlinear difference system Hamiltonian difference system
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A Mehrotra-Type Predictor-Corrector Algorithm for P_*(κ) Linear Complementarity Problems
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作者 Weihua LI Mingwang ZHANG Yiyuan ZHOU 《Journal of Mathematical Research with Applications》 CSCD 2012年第3期297-312,共16页
Mehrotra-type predictor-corrector algorithm, as one of most efficient interior point methods, has become the backbones of most optimization packages. Salahi et al. proposed a cut strategy based algorithm for linear op... Mehrotra-type predictor-corrector algorithm, as one of most efficient interior point methods, has become the backbones of most optimization packages. Salahi et al. proposed a cut strategy based algorithm for linear optimization that enjoyed polynomial complexity and maintained its efficiency in practice. We extend their algorithm to P. (~) linear complementar- ity problems. The way of choosing corrector direction for our algorithm is different from theirs: The new algorithm has been proved to have an O((1 + 4k)(17 + 19k)√1+2kn 3/2 log(x0)Ts0/ε) worst case iteration complexity bound. An numerical experiment verifies the feasibility of the new algorithm. 展开更多
关键词 P*(k) linear complementarity problems Mehrotra-type predictor-corrector algo- rithm polynomial iteration complexity interior point method.
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A TOBIN-TYPE ESTIMATE OF CENSORED LINEAR MODELS
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作者 陈希孺 朱力行 《Acta Mathematica Scientia》 SCIE CSCD 1998年第4期361-370,共10页
The paper presents a two-stage method for estimating the parameters in the censored linear model Y-i = max(0, alpha(o) + X-i'beta(o)), 1 less than or equal to i less than or equal to n. In the first stage the data... The paper presents a two-stage method for estimating the parameters in the censored linear model Y-i = max(0, alpha(o) + X-i'beta(o)), 1 less than or equal to i less than or equal to n. In the first stage the data are grouped in some groups and then some adjustments are made, the results are used in the latter stage to form a Tobin-type estimate. The asymptotic normality of the estimate is proved and some simulations are made. 展开更多
关键词 CENSORING linear models Tobin-type estimate
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直线导轨式隔震装置的设计与性能研究
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作者 赵守江 柏文 《地震工程学报》 北大核心 2025年第1期50-59,共10页
为确保馆藏文物的地震安全,研制出一款新型直线导轨式隔震装置,采用振动台试验和理论分析方法对其有效性进行验证。首先阐述装置的构造和工作机理,推导出装置的刚度和黏滞阻尼系数表达式;然后制作原型样机并通过振动台试验验证其隔震有... 为确保馆藏文物的地震安全,研制出一款新型直线导轨式隔震装置,采用振动台试验和理论分析方法对其有效性进行验证。首先阐述装置的构造和工作机理,推导出装置的刚度和黏滞阻尼系数表达式;然后制作原型样机并通过振动台试验验证其隔震有效性;最后依据所测基本参数,建立装置单向水平隔震系统的动力方程并开展数值分析。结果表明,该隔震装置结构简单、性能可靠,具有摩擦系数低、起滑加速度阈值小,以及刚度和阻尼灵活可调的特点;它可以在满足位移限值的情况下达到设定隔震目标,且自复位效能力强、残余位移小。装置理论分析结果与试验实测动力响应吻合程度高,且吻合程度随地震动峰值的提高而进一步增强。该理论分析方法可以用于指导装置参数设计和隔震性能评估。 展开更多
关键词 文物 隔震 直线导轨式 振动台试验 数值模拟
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Stechkin-Marchaud Type Inequalities in Lp for Linear Combination of Bernstein-Durrmeyer Operators
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作者 Feng Guo Meiqin Ke 《Open Journal of Applied Sciences》 2012年第4期228-232,共5页
In this paper, we use the equivalence relation between K-functional and modulus of smoothness, and give the Stechkin-Marchaud-type inequalities for linear combination of Bernstein-Durrmeyer operators . Moreover, we ob... In this paper, we use the equivalence relation between K-functional and modulus of smoothness, and give the Stechkin-Marchaud-type inequalities for linear combination of Bernstein-Durrmeyer operators . Moreover, we obtain the inverse result of approximation for linear combination of Bernstein-Durrmeyer operators with . Meanwhile we unify and extend some previous results. 展开更多
关键词 BERNSTEIN-DURRMEYER OPERATORS linear combination K-FUNCTIONAL Stechkin-Marchaud-type inequalities modulus of smoothness
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Bianchi Type-V Cosmological Model with Linear Equation of State in Brans-Dicke Theory of Gravitation
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作者 Sharad Kandalkar Seema Samdurkar 《International Journal of Astronomy and Astrophysics》 2014年第3期429-436,共8页
A Bianchi type-V space time is considered with linear equation of state in the scalar tensor theory of gravitation proposed by Brans and Dicke. We use the assumption of constant deceleration parameter and power law re... A Bianchi type-V space time is considered with linear equation of state in the scalar tensor theory of gravitation proposed by Brans and Dicke. We use the assumption of constant deceleration parameter and power law relation between scalar field &oslash;and scale factor R to find the solutions. Some physical and kinematical properties of the model are also discussed. 展开更多
关键词 Bianchi type-V Model BRANS-DICKE Theory linear Equation of State
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融合局部加权回归与LQR控制的线控转向系统控制策略研究
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作者 潘公宇 刘艳旭 《重庆理工大学学报(自然科学)》 北大核心 2025年第8期1-9,共9页
以线控转向系统汽车为研究对象,提出了一种利用局部加权回归和样条插值法优化理想传动比结合线性二次型调节器(linear quadratic regulator,LQR)控制算法的线控转向控制策略,实现了前轮主动转向控制。通过Simulink与Carsim的联合仿真,... 以线控转向系统汽车为研究对象,提出了一种利用局部加权回归和样条插值法优化理想传动比结合线性二次型调节器(linear quadratic regulator,LQR)控制算法的线控转向控制策略,实现了前轮主动转向控制。通过Simulink与Carsim的联合仿真,对线控转向系统进行分析,以验证其工作稳定性。通过固定横摆角速度增益和侧向加速度增益,制定了理想的角传动比控制策略,同时利用局部加权回归和样条插值法对设计得到的角传动比曲线进行平滑处理,确保了传动比曲线的连续性和稳定性。在此基础上,设计了LQR控制器,用于计算附加转角,以补偿车辆在行驶过程中的不稳定性。仿真结果表明:所提出的控制策略能够有效提高车辆的操控性和稳定性,并且在速度60 km/h时,横摆角速度和质心侧偏角的峰值分别下降35.7%和36.3%,为进一步提升车辆在各种复杂路况下的适应能力奠定了坚实的基础。 展开更多
关键词 线控转向系统 线性二次型 理想传动比 局部加权回归 样条插值法
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A matrix Padé-type-Routh model reduction method for multivariable linear systems
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作者 吴蓓蓓 顾传青 《Journal of Shanghai University(English Edition)》 CAS 2006年第5期377-380,共4页
In the present paper, the formulae for matrix Padé-type approximation were improved. The mixed model reduction method of matrix Padé-type-Routh for the multivariable linear systems was presented. A well-know... In the present paper, the formulae for matrix Padé-type approximation were improved. The mixed model reduction method of matrix Padé-type-Routh for the multivariable linear systems was presented. A well-known example was given to illustrate that the mixed method is efficient. 展开更多
关键词 matrix Padé-type approximation(MPTA) Routh table model reduction multivariable linear systems
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Polynomial Complexity Bounds of Mehrotra-type Predictor-corrector Algorithms for Linear Programming over Symmetric Cones
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作者 刘长河 尚有林 李振国 《Chinese Quarterly Journal of Mathematics》 2015年第4期475-494,共20页
We establish polynomial complexity corrector algorithms for linear programming over bounds of the Mehrotra-type predictor- symmetric cones. We first slightly modify the maximum step size in the predictor step of the s... We establish polynomial complexity corrector algorithms for linear programming over bounds of the Mehrotra-type predictor- symmetric cones. We first slightly modify the maximum step size in the predictor step of the safeguard based Mehrotra-type algorithm for linear programming, that was proposed by Salahi et al. Then, using the machinery of Euclidean Jordan algebras, we extend the modified algorithm to symmetric cones. Based on the Nesterov-Todd direction, we obtain O(r log ε1) iteration complexity bound of this algorithm, where r is the rank of the Jordan algebras and ε is the required precision. We also present a new variant of Mehrotra-type algorithm using a new adaptive updating scheme of centering parameter and show that this algorithm enjoys the same order of complexity bound as the safeguard algorithm. We illustrate the numerical behaviour of the methods on some small examples. 展开更多
关键词 linear programming symmetric cone Euclidean Jordan algebra interior-point methods Mehrotra-type algorithm polynomial complexity
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初级分离式U型永磁开关磁链直线电机特性分析及优化
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作者 许孝卓 王雪 +1 位作者 杜宝玉 赵运基 《兵器装备工程学报》 北大核心 2025年第9期84-93,136,共11页
针对Spoke型永磁励磁的初级分离式开关磁链直线电机(SPM-PPFSLM)底部漏磁导致的永磁体利用率低、推力波动大等问题,提出一种聚磁式U型永磁励磁的初级分离式永磁开关磁链直线电机(UPM-PPFSLM)。分析UPM-PPFSLM的拓扑结构及其工作机理;利... 针对Spoke型永磁励磁的初级分离式开关磁链直线电机(SPM-PPFSLM)底部漏磁导致的永磁体利用率低、推力波动大等问题,提出一种聚磁式U型永磁励磁的初级分离式永磁开关磁链直线电机(UPM-PPFSLM)。分析UPM-PPFSLM的拓扑结构及其工作机理;利用有限元法研究关键结构参数对UPM-PPFSLM电磁性能的影响,对比分析UPM-PPFSLM与SPM-PPFSLM的电磁特性;以平均推力和推力波动为优化目标,结合Kriging代理模型与MOPSO多目标优化算法对UPM-PPFSLM进行多目标优化;通过添加端部辅助齿,并对端齿参数进行优化,从而削弱定位力。结果表明,UPM-PPFSLM的U型聚磁结构有效改善了漏磁现象,强化了气隙磁场,相对SPM-PPFSLM推力增加13.7%,推力波动降低28.6%,显著提升了电机的电磁性能;优化后UPM-PPFSLM的平均推力提升了5.8%,推力波动降低了33.3%,且经端部优化后定位力削弱了45.4%。 展开更多
关键词 永磁开关磁链直线电机 初级分离式 U型永磁 电磁特性 多目标优化
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Identification of Question and Non-Question Segments in Arabic Monologues Using Prosodic Features: Novel Type-2 Fuzzy Logic and Sensitivity-Based Linear Learning Approaches
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作者 Sunday Olusanya Olatunji Lahouari Cheded +1 位作者 Wasfi G. Al-Khatib Omair Khan 《Journal of Intelligent Learning Systems and Applications》 2013年第3期165-175,共11页
In this paper, we extend our previous study of addressing the important problem of automatically identifying question and non-question segments in Arabic monologues using prosodic features. We propose here two novel c... In this paper, we extend our previous study of addressing the important problem of automatically identifying question and non-question segments in Arabic monologues using prosodic features. We propose here two novel classification approaches to this problem: one based on the use of the powerful type-2 fuzzy logic systems (type-2 FLS) and the other on the use of the discriminative sensitivity-based linear learning method (SBLLM). The use of prosodic features has been used in a plethora of practical applications, including speech-related applications, such as speaker and word recognition, emotion and accent identification, topic and sentence segmentation, and text-to-speech applications. In this paper, we continue to specifically focus on the Arabic language, as other languages have received a lot of attention in this regard. Moreover, we aim to improve the performance of our previously-used techniques, of which the support vector machine (SVM) method was the best performing, by applying the two above-mentioned powerful classification approaches. The recorded continuous speech is first segmented into sentences using both energy and time duration parameters. The prosodic features are then extracted from each sentence and fed into each of the two proposed classifiers so as to classify each sentence as a Question or a Non-Question sentence. Our extensive simulation work, based on a moderately-sized database, showed the two proposed classifiers outperform SVM in all of the experiments carried out, with the type-2 FLS classifier consistently exhibiting the best performance, because of its ability to handle all forms of uncertainties. 展开更多
关键词 ARABIC Monologues Prosodic Features type-2 FUZZY LOGIC Systems Sensitivity Based linear LearningMethod Support Vector Machines
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基于Koopman滤波的双条状抗温光学电流传感器设计及实验研究
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作者 张静 李岩松 +2 位作者 张子傲 侯凯允 刘君 《仪器仪表学报》 北大核心 2025年第5期20-31,共12页
光学电流传感器符合新型电力系统智能化,数字化的发展需求,但目前光学电流传感器在电力系统宽温域测量中没有同时满足实时性和长期运行稳定性的抗温方案。为此,提出了一种基于Koopman自适应滤波的双条状抗温磁光式光学电流传感器(DS-MO... 光学电流传感器符合新型电力系统智能化,数字化的发展需求,但目前光学电流传感器在电力系统宽温域测量中没有同时满足实时性和长期运行稳定性的抗温方案。为此,提出了一种基于Koopman自适应滤波的双条状抗温磁光式光学电流传感器(DS-MOCT)。首先介绍了磁光传感原理以及磁光传感温度扰动机理,应用琼斯矩阵构建了直通光路式光学电流传感器起检偏器任意角度光学电流传感偏振解析模型;然后分析起检偏器不同角度对传感器输出结果的影响并提出了起检偏器特殊角度温度补偿方法,构建了DS-MOCT抗温结构,包括测量臂和温度补偿臂,测量臂输出待测电流信号,温度补偿臂输出温度补偿信号,使用温度补偿信号对待测电流信号实时抗温补偿,DS-MOCT输出抗温扰动测量电流值;分析了DS-MOCT的误差来源并提出了基于Koopman理论的降噪方法;接着,在有限元仿真软件中模拟了实验系统中DS-MOCT多物理场耦合环境,可视化了DS-MOCT光波抗温过程,验证了DS-MOCT的抗温性能;最后搭建了软硬件协同设计的DS-MOCT实测系统。实验结果表明,在-40℃~40℃宽温域内,DS-MOCT测量误差<0.2%,满足GB/T 20840.8—2007对电子式互感器的0.2级测量标准;动态响应时间<14 ms,满足电力系统实时监控需求。所提基于Koopman自适应滤波的DS-MOCT,解决了新型电力系统中光学电流传感器的抗温性、实时性与长期运行稳定性之间的三重矛盾。 展开更多
关键词 直通光路式光学电流传感器 线性双折射 温度补偿 起检偏器特殊角度 Koopman自适应滤波
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新结构U型永磁直线同步电机分析与优化设计
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作者 上官璇峰 赵磊 +1 位作者 张龙祺 李世豪 《制造业自动化》 2025年第5期152-159,共8页
针对U型无铁芯永磁同步直线电机推力较小的问题,提出了一种新结构U型永磁同步直线电机。该电机通过在初级内增设导磁块,改变主磁路结构的方法,使电磁推力增加了74.36%,并且将推力波动控制在较小的范围内。首先,通过解析法求解电机气隙... 针对U型无铁芯永磁同步直线电机推力较小的问题,提出了一种新结构U型永磁同步直线电机。该电机通过在初级内增设导磁块,改变主磁路结构的方法,使电磁推力增加了74.36%,并且将推力波动控制在较小的范围内。首先,通过解析法求解电机气隙内永磁场,并通过对气隙磁场磁通密度的谐波分析,讨论了谐波成份对电机推力及推力波动的影响。然后,分析了若干参数对电机性能的影响,采用田口法对优化变量进行筛选,并通过响应曲面法获取体现优化目标与参数之间函数关系的数学模型。最后,采用白鹭群多目标优化算法对电机进行优化设计,获取了Pareto前沿。通过有限元仿真验证了理论分析的有效性。 展开更多
关键词 U型永磁同步直线电机 导磁块 磁场分析 多目标优化设计
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混凝土抗滑桩加固边坡支护的受力特征研究
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作者 许佳 许登科 《陇东学院学报》 2025年第5期82-87,共6页
设计了两种结构形式的连梁混凝土抗滑桩试件(直线型和拱形),对比分析了抗滑桩的桩后土压力-埋深、桩顶位移-加载级数和桩身弯矩-埋深的变化曲线。结果表明,两种抗滑桩的桩后土压力都会随着埋深增加而先增大后减小,且随着载荷增加,抗滑... 设计了两种结构形式的连梁混凝土抗滑桩试件(直线型和拱形),对比分析了抗滑桩的桩后土压力-埋深、桩顶位移-加载级数和桩身弯矩-埋深的变化曲线。结果表明,两种抗滑桩的桩后土压力都会随着埋深增加而先增大后减小,且随着载荷增加,抗滑桩的桩后土压力峰值逐渐增大;在边坡加固过程中,优先需要考虑边坡滑移面以上区域的安全性。在相同加载级数下,直线型混凝土抗滑桩的桩顶切向位移小于拱形混凝土抗滑桩,而法向位移要明显高于拱形混凝土抗滑桩,约为后者的4倍。直梁钢管桩桩身正弯矩峰值小于拱形钢管桩,而负向弯矩峰值要大于拱形钢管桩。 展开更多
关键词 混凝土 抗滑桩 直线型 拱形 力学性能
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