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Coefficient Estimates for a Subclass of Bi-univalent Strongly Quasi-starlike Functions 被引量:2
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作者 LI ZONG-TAO GUO DONG Ji You-qing 《Communications in Mathematical Research》 CSCD 2018年第4期303-308,共6页
The aim of this paper is to establish the Fekete-Szego inequality for a subclass of bi-univalent strongly quasi-starlike functions which is defined in the open unit disk. Furthermore, the coefficients a2 and a3 for fu... The aim of this paper is to establish the Fekete-Szego inequality for a subclass of bi-univalent strongly quasi-starlike functions which is defined in the open unit disk. Furthermore, the coefficients a2 and a3 for functions in this new subclass are estimated. 展开更多
关键词 bi-univalent function bi-univalent strongly quasi-starlike function coefficient estimate SUBORDINATION
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ON THE COEFFICIENTS OF A POLYNOMIAL WITH RESTRICTED ZEROS
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作者 Abdul Aziz W. M. Shah 《Analysis in Theory and Applications》 2009年第2期142-146,共5页
Let P(z)=anz^n+an-1z^n-1+…+a0be a complex polynomial of degree n. There is a close connection between the coefficients and the zeros of P(z). In this paper we prove some sharp inequalities concerning the coeff... Let P(z)=anz^n+an-1z^n-1+…+a0be a complex polynomial of degree n. There is a close connection between the coefficients and the zeros of P(z). In this paper we prove some sharp inequalities concerning the coefficients of the polynomial P(z) with restricted zeros. We also establish a sufficient condition for the separation of zeros of P(z). 展开更多
关键词 polynomial inequality coefficient estimate separation of zeros
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Fekete-Szego Estimate for a Class of Starlike Functions Involving Certain Analytic Multiplier Transform
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作者 Deborah Olufunmialyo Makinde A.S.Oyekunle T.O.Opoola 《Journal of Applied Mathematics and Physics》 2020年第3期519-526,共8页
In this paper, we investigated the coefficient estimates and the Fekete-Szeg&#246;?problem for the subclass of analytic univalent functions involving the linear transformation Dsα,β,γf for the normalized analyt... In this paper, we investigated the coefficient estimates and the Fekete-Szeg&#246;?problem for the subclass of analytic univalent functions involving the linear transformation Dsα,β,γf for the normalized analytic function f (z) = z + a2z2 + a3z3 + … . 展开更多
关键词 ANALYTIC UNIVALENT STARLIKE Linear Transformation coefficient estimates Fekete-Szego Inequality
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Roughness coefficient and its uncertainty in gravel-bed river 被引量:2
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作者 Ji-Sung KIM Chan-Joo LEE +1 位作者 Won KIM Yong-Jeon KIM 《Water Science and Engineering》 EI CAS 2010年第2期217-232,共16页
Manning's roughness coefficient was estimated for a gravel-bed river reach using field measurements of water level and discharge, and the applicability of various methods used for estimation of the roughness coeffici... Manning's roughness coefficient was estimated for a gravel-bed river reach using field measurements of water level and discharge, and the applicability of various methods used for estimation of the roughness coefficient was evaluated. Results show that the roughness coefficient tends to decrease with increasing discharge and water depth, and over a certain range it appears to remain constant. Comparison of roughness coefficients calculated by field measurement data with those estimated by other methods shows that, although the field-measured values provide approximate roughness coefficients for relatively large discharge, there seems to be rather high uncertainty due to the difference in resultant values. For this reason, uncertainty related to the roughness coefficient was analyzed in terms of change in computed variables. On average, a 20% increase of the roughness coefficient causes a 7% increase in the water depth and an 8% decrease in velocity, but there may be about a 15% increase in the water depth and an equivalent decrease in velocity for certain cross-sections in the study reach. Finally, the validity of estimated roughness coefficient based on field measurements was examined. A 10% error in discharge measurement may lead to more than 10% uncertainty in roughness coefficient estimation, but corresponding uncertainty in computed water depth and velocity is reduced to approximately 5%. Conversely, the necessity for roughness coefficient estimation by field measurement is confirmed. 展开更多
关键词 roughness coefficient estimation field measurement gravel-bed river UNCERTAINTY
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WAVE CURRENT FORCE COEFFICIENTS ON INCLINED CYLINDER AND A NEW ESTIMATION METHOD 被引量:2
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作者 Teng Bin and Li Yucheng Research Assistant, Dalian University of Technology, Dalian Professor, Dalian University of Technology, Dalian 《China Ocean Engineering》 SCIE EI 1990年第3期283-296,共14页
Based on the review of present force coefficients estimation methods, a new method in the frequency domain, revised cross-spectrum estimation method, is presented in this paper. Some experiments on the wave-current fo... Based on the review of present force coefficients estimation methods, a new method in the frequency domain, revised cross-spectrum estimation method, is presented in this paper. Some experiments on the wave-current force on inclined cylinders are also described and the wave current force coefficients are estimated by the revised cross-spectrum estimation method. From the results, it is found that the wave and current directions have some regular effect on the coefficients. According to the results, some empirical formulas are obtained for converting the wave-current force coefficients on inclined cylinders into a unified coefficient. Comparisons show that the unified coefficients are in good agreement with other results. 展开更多
关键词 WAVE CURRENT FORCE coefficientS ON INCLINED CYLINDER AND A NEW ESTIMATION METHOD Mean
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Estimation of Mutual Coupling Coefficient of the Array by Simulated Annealing Algorithm 被引量:1
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作者 GAO Huo-tao ZHENG Xia LI Yong-xu 《Wuhan University Journal of Natural Sciences》 CAS 2005年第6期1000-1004,共5页
We propose a method for estimating the mutual coupling coefficient among antennas in this paper which is based on the principle of signal subspace and the simulated annealing (SA) algorithm. The computer simulation ... We propose a method for estimating the mutual coupling coefficient among antennas in this paper which is based on the principle of signal subspace and the simulated annealing (SA) algorithm. The computer simulation has been conducted to illustrate the' excellent performance of this method and to demonstrate that it is statistically efficient. The benefit of this new method is that calibration signals and unknown signals can be received simultaneously, during the course of calibration. 展开更多
关键词 mutual coupling coefficient from array estimation of mutual coupling coefficient simulated annealing(SA) algorithm
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Statistical characteristics and model estimation of coefficient of recharge of rainfall infiltration
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《Global Geology》 1998年第1期118-119,共2页
关键词 Statistical characteristics and model estimation of coefficient of recharge of rainfall infiltration
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q–differ-integral operator on p–valent functions associated with operator on Hilbert space
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作者 Shahram Najafzadeh 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2023年第3期458-466,共9页
Making use of multivalent functions with negative coefficients of the type f (z)=z^(p)-~(∑)_(k=p+1)^(∞)a_(k)z^(k),which are analytic in the open unit disk and applying the q-derivative a q–differintegral operator i... Making use of multivalent functions with negative coefficients of the type f (z)=z^(p)-~(∑)_(k=p+1)^(∞)a_(k)z^(k),which are analytic in the open unit disk and applying the q-derivative a q–differintegral operator is considered.Furthermore by using the familiar Riesz-Dunford integral,a linear operator on Hilbert space H is introduced.A new subclass of p-valent functions related to an operator on H is defined.Coefficient estimate,distortion bound and extreme points are obtained.The convolution-preserving property is also investigated. 展开更多
关键词 multivalent function fractional q–derivative operator fractional q–integral operator Hilbert space coefficient estimate distortion bound extreme point convolution(or Hadamard product)
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Fekete-Szegö Inequality for a Subclass of Bi-univalent Functions Associated with Hohlov Operator and Quasi-subordination 被引量:1
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作者 Guo Dong Tang Huo +1 位作者 Ao En Xiong Liang-peng 《Communications in Mathematical Research》 CSCD 2019年第3期235-246,共12页
In this paper, we introduce a new subclass of bi-univalent functions defined by quasi-subordination and Hohlov operator and obtain the coefficient estimates and Fekete-Szego inequality for function in this new subclas... In this paper, we introduce a new subclass of bi-univalent functions defined by quasi-subordination and Hohlov operator and obtain the coefficient estimates and Fekete-Szego inequality for function in this new subclass. The results presented in this paper improve or generalize the recent works of other authors. 展开更多
关键词 analytic function univalent function bi-univalent function coefficient estimate Fekete-Szegö inequality Hohlov operator quasi-subordination
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Noise level estimation method with application to EMD-based signal denoising 被引量:3
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作者 Xiaoyu Li Jing Jin +1 位作者 Yi Shen Yipeng Liu 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2016年第4期763-771,共9页
This paper proposes a new signal noise level estimation approach by local regions. The estimated noise variance is applied as the threshold for an improved empirical mode decomposition(EMD) based signal denoising me... This paper proposes a new signal noise level estimation approach by local regions. The estimated noise variance is applied as the threshold for an improved empirical mode decomposition(EMD) based signal denoising method. The proposed estimation method can effectively extract the candidate regions for the noise level estimation by measuring the correlation coefficient between noisy signal and a Gaussian filtered signal. For the improved EMD based method, the situation of decomposed intrinsic mode function(IMFs) which contains noise and signal simultaneously are taken into account. Experimental results from two simulated signals and an X-ray pulsar signal demonstrate that the proposed method can achieve better performance than the conventional EMD and wavelet transform(WT) based denoising methods. 展开更多
关键词 signal denoising empirical mode decomposition(EMD) Gaussian filter correlation coefficient noise level estimation
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Algorithm of heating temperature for Chongqing's winter greenhouses
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作者 谢守勇 LI Xi-wen +1 位作者 YANG Shu-zi YANG Ming-jin 《Journal of Chongqing University》 CAS 2007年第1期50-54,共5页
Internal temperature is crucial to plant growth in the greenhouse. We investigated the patterns of constructing and managing greenhouses in Chongqing, and developed an algorithm of heating temperature for closed winte... Internal temperature is crucial to plant growth in the greenhouse. We investigated the patterns of constructing and managing greenhouses in Chongqing, and developed an algorithm of heating temperature for closed winter plastic greenhouses under the conditions of no man-made illumination, no ventilation and hot wind machine as the heating equipment, which are the most adopted pattern of greenhouses in Chongqing area. The algorithm includes two functions of temperature outside the greenhouse, which calculate the values of the warming estimation coefficient (WEC) and the gap between temperatures inside and outside the greenhouse with the measured data of outside temperature, and then give the value of internal temperature; the heat rating of heating facilities required by a greenhouse can be determined by this algorithm with given values of floor area and internal temperature, measured outside temperature and calculated WEC. Verification of the algorithm demonstrates a desirable accuracy of estimation. Algorithms of computing heating temperature for greenhouses of different constructing and managing patterns and in different geographic conditions can also be derived in a similar way. This research presents a paradigm for developing a feasible method to fit out greenhouses with appropriate heating facilities, aiming at energy efficient and cost efficient production. 展开更多
关键词 heating balance equation warming estimation coefficient estimation algorithm
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Partial sums of generalized harmonic starlike univalent functions generated by a (p,q)−Ruscheweyh-type harmonic differential operator
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作者 Om P Ahuja Asena Cetinkaya Raj Kumar 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE 2024年第4期584-595,共12页
Let H denote the class of complex-valued harmonic functions f defined in the open unit disc D and normalized by f(0)=fz(0)-1=0.In this paper,we define a new generalized subclass of H associated with the(p,q)-Ruschewey... Let H denote the class of complex-valued harmonic functions f defined in the open unit disc D and normalized by f(0)=fz(0)-1=0.In this paper,we define a new generalized subclass of H associated with the(p,q)-Ruscheweyh-type harmonic differential operator in D.We first obtain a sufficient coefficient condition that guarantees that a function f in H is sense-preserving harmonic univalent in D and belongs to the aforementioned class.Using this coefficient condition,we then examine ratios of partial sums of f in H.In all cases the results are sharp.In addition,the results so obtained generalize the related works of some authors,and many other new results are obtained. 展开更多
关键词 (p q)-calculus (p q)-derivative operator q-calculus q-derivative operator (p q)-Ruscheweyhtype harmonic differential operator partial sums coefficient estimate
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ADMISSIBILITY OF LINEAR ESTIMATORS OF REGRESSION COEFFICIENTS UNDER QUADRATIC LOSS 被引量:1
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作者 詹金龙 陈建宝 《Acta Mathematicae Applicatae Sinica》 SCIE CSCD 1992年第3期237-244,共8页
For the general fixed effects linear model: Y = X_T+ε, ε~N(0, V), V≥0, weobtain the necessary and sufficient conditions for LY +a to be admissible for a linear estimablefunction S_r in the class of all estimators ... For the general fixed effects linear model: Y = X_T+ε, ε~N(0, V), V≥0, weobtain the necessary and sufficient conditions for LY +a to be admissible for a linear estimablefunction S_r in the class of all estimators under the loss function (d -- Sr)'D(d --Sr), whereD≥0 is known. For the general random effects linear model: Y = Xβ+ε,(βε)~N((Aα 0), (V_(11)V_(12)V_(21)V_(22))), ∧= XV_(11)X'+XV_(12)+ V_(21)X+V_(22)≥0, we also get the necessaryand sufficient conditions for LY+a to be admissible for a linear estimable function Sα+Qβin the class of all estimators under the loss function (d-Sα-Qβ)'D(d-Sα-Qβ).whereD≥0 is known. 展开更多
关键词 LY LQI QA ADMISSIBILITY OF LINEAR ESTIMATORS OF REGRESSION coefficientS UNDER QUADRATIC LOSS
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Empirical Likelihood-based Inferences in Varying Coefficient Models with Missing Data
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作者 Xiao-hui LIU 《Acta Mathematicae Applicatae Sinica》 SCIE CSCD 2015年第3期823-840,共18页
In this paper, we consider the empirical likelihood-based inferences for varying coefficient models Y = X^τα(U) + ε when X are subject to missing at random. Based on the inverse probability-weighted idea, a clas... In this paper, we consider the empirical likelihood-based inferences for varying coefficient models Y = X^τα(U) + ε when X are subject to missing at random. Based on the inverse probability-weighted idea, a class of empirical log-likelihood ratios, as well as two maximum empirical likelihood estimators, are developed for α(u). The resulting statistics are shown to have standard chi-squared or normal distributions asymptotically.Simulation studies are also constructed to illustrate the finite sample properties of the proposed statistics. 展开更多
关键词 varying coefficient models missing at random empirical likelihood maximum empirical likelihood estimator
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Properties of New Holomorphic Mappings with Respect to Conic Domains
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作者 Yan Yan CUI Yong Hong XIE +1 位作者 He Ju YANG Yu Ying QIAO 《Acta Mathematica Sinica,English Series》 SCIE CSCD 2021年第6期971-991,共21页
This paper is mainly about holomorphic mappings associated with conic regions which are closely connected with k-ST(α).We introduce new subclasses of starlike(spirallike)functions,namely,S^(p)_(c)(k,α)(S^(p)_(c)(k,... This paper is mainly about holomorphic mappings associated with conic regions which are closely connected with k-ST(α).We introduce new subclasses of starlike(spirallike)functions,namely,S^(p)_(c)(k,α)(S^(p)_(c)(k,α,β)),and discuss their coefficient estimates and the Fekete–Szego–Goluzin’s problem.Then we generalize S^(p)_(c)(k,α,β)on the unit ball B^(n) in C^(n),that is,k-conic spirallike mappings of typeβand orderα.We obtain the growth,covering and distortion theorems of the generalized mappings.Besides that,we construct k-conic spirallike mappings of typeβand orderαon B^(n) through S_(c)(k,α,β)by the generalized Roper-Suffridge extension operators. 展开更多
关键词 Holomorphic mappings coefficient estimates growth theorems Roper-Suffridge operators
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On quasi-convex mappings of order α in the unit ball of a complex Banach space 被引量:9
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作者 LIU Taishun & XU Qinghua Department of Mathematics, Huzhou Teachers College, Huzhou, 313000, China Department of Mathematics, Jiangxi Normal University, Nanchang, 330022, China 《Science China Mathematics》 SCIE 2006年第11期1451-1457,共7页
In this paper, a class of biholomorphic mappings named quasi-convex mapping of order a in the unit ball of a complex Banach space is introduced. When the Banach space is confined to Cn, we obtain the relation between ... In this paper, a class of biholomorphic mappings named quasi-convex mapping of order a in the unit ball of a complex Banach space is introduced. When the Banach space is confined to Cn, we obtain the relation between this class of mappings and the convex mappings. Furthermore, the growth and covering theorems of this class of mappings are given on the unit ball of a complex Banach space X. Finally, we get the second order terms coefficient estimations of the homogeneous expansion of quasi-convex mapping of order a defined on the polydisc in Cn and on the unit ball in a complex Banach space, respectively. 展开更多
关键词 coefficient estimation the homogeneous expansion quasi-convex mapping quasi-convex mapping of order a.
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