检索结果-内蒙古大学图书馆

A COMPARISON OF FIVE DIFFERENT SCORING functions FOR CONFIDENCE TESTS

Journal of Educational Measurement 1970年第3期7卷 165-170页

作者： RIPPEY, ROBERT M. The University of Chicago Chicago Illinois United States

Several parts of the STEP Writing Test, Level 1, were administered to 14 different groups of from 19 to 52 high school students. In the testing situations, scores were computed using the following scoring functions: (a) probability assigned to the correct answer, (b) the logarithmic function, (c) the spherical function, (d) the Euclidean function, and (e) inferred choice. Reliabilities of the scores obtained by means of each scoring function were computed. Comparisons between the reliabilities showed that the simplest and most intuitive function, the probability assigned to the correct answer, produced the highest reliability in comparison with any of the other functions. The data suggest that in the absence of information about the scoring system, subjects assign their confidence in multiple‐choice responses on the basis of the intuitively simplest payoff model, and that reliability decreases as scoring functions generate item scores which are progressively discrepant from scores generated by the simplest model. Copyright © 1970, Wiley Blackwell. All rights reserved

关键词： High school students logarithmic functions Writing tests

来源：评论

学校读者我要写书评

暂无评论

A SECOND NORMAL FORM FOR functions OF THE SYSTEM EP

引用

Mathematical Logic Quarterly 1984年第25期30卷 393-400页

作者： McBeth, Rod London E15 3EN 10 John Street Stratford United Kingdom

The article discusses the second normal form for system EP of exponential functions. It explains the two specialized theorems on the starting properties of the standard assignment and additional information about Ω. It tackles on Bachmann fundamental sequence starting property which is important in establishing the increasing property of the generalization.

关键词： EXPONENTIAL functions THEOREMS (Mathematics) MATHEMATICAL analysis logarithmic functions POLYNOMIALS

来源：评论

学校读者我要写书评

暂无评论

Using relevance queries for identification of read-once functions

引用

Journal of Mathematical Sciences (United States) 2013年第3期192卷 359-374页

作者： Chistikov, D.V. Max Planck Institute for Software Systems (MPI-SWS) Kaiserslautern and Saarbrücken Germany

A Boolean function is called read-once if it can be expressed by a formula over {∧, ∨, -} where no variable appears more than once. The problem of identifying an unknown read-once function f depending on a known set... 详细信息

A Boolean function is called read-once if it can be expressed by a formula over {∧, ∨, ^-} where no variable appears more than once. The problem of identifying an unknown read-once function f depending on a known set of variables x₁,..., x_n by making queries is considered. Algorithms are allowed to perform standard membership queries and queries of two special types allowing to reveal the relevance of variables to projections of f. Two exact identification algorithms are developed: one makes O(n ²) yes-no queries, and the other makes O(n log² n) queries with logarithmically long answers. The information-theoretic lower bound on the number of bits transferred from oracles to the identification algorithms in the worst case is Ω(n log n). Bibliography: 14 titles. © 2013 Springer Science+Business Media New York.

关键词： BOOLEAN functions (Mathematics) MATHEMATICAL formulas VARIABLES (Mathematics) ALGORITHMS logarithmic functions INFORMATION theory SET theory

来源：评论

学校读者我要写书评

暂无评论

On regular realizability problems

引用

PROBLEMS OF INFORMATION TRANSMISSION 2011年第4期47卷 342-352页

作者： Vyalyi, M. N. Russian Acad Sci Ctr Comp Moscow 117901 Russia

We consider the class of regular realizability problems. Any of such problems is specified by some language (filter) and consists in verifying that the intersection of a given regular language and the filter is nonempty. The main question is diversity of the computational complexity of such problems. We show that any regular realizability problem with an infinite filter is hard for a class of problems decidable in logarithmic space with respect to logarithmic reductions. We give examples of NP-complete and PSPACE-complete regular realizability problems.

关键词： NP-complete problems DECIDABILITY (Mathematical logic) DIGITAL filters (Mathematics) logarithmic functions CAYLEY graphs

来源：评论

学校读者我要写书评

暂无评论

The renormalization-group improved effective potential in the Wess-Zumino model

引用

CANADIAN JOURNAL OF PHYSICS 2004年第9期82卷 737-742页

作者： McKeon, DGC Univ Western Ontario Dept Appl Math London ON N6A 5B7 Canada

The one-loop correction to the effective potential in the massless Wess-Zumino supersymmetric model is computed using operator regularization. The renormalization group is used to determine the scale dependence of the parameters characterizing the model (the coupling and background field strength) and to sum leading logarithm contributions to the effective potential to all orders of perturbation theory, using the method of characteristics.

关键词： ELECTRIC currents PERTURBATION (Mathematics) logarithmic functions QUANTUM field theory MATHEMATICAL physics PHYSICS

来源：评论

学校读者我要写书评

暂无评论

Discussion of "San Jacinto Monument Case History" by Jean-Louis Briaud, Jennifer Nicks, Keunyoung Rhee, and Gregory Stieben

引用

JOURNAL OF GEOTECHNICAL AND GEOENVIRONMENTAL ENGINEERING 2009年第1期135卷 162-167页

作者： Fellenius, Bengt H. Ochoa, Mauricio Bengt Fellenius Consultants Inc Calgary AB T2G 4J3 Canada Tolunay Wong Engn Inc Houston TX 77031 USA

The article discusses the article "San Jacinto Monument Case History," by Jean-Louis Briaud, Jennifer Nicks, Keunyoung Rhee and Gregory Stieben. It comments on the elastic approach of applied by the researchers. It mentions that the researchers did not consider the compression and stress of soil. In addition, the values and indices are scattered and produce less than what is expected. The authors explain the preconsolidation margin on ground surface. They also change the scale from linear time scale to linear and logarithmic scales in settling the records.

关键词： CASE method (Teaching) SETTLEMENT of structures ENVIRONMENTAL indicators SOILS STRAINS & stresses (Mechanics) ELASTICITY LINEAR systems logarithmic functions STRENGTH of materials

来源：评论

学校读者我要写书评

暂无评论

Limiting Soil Resistance to the Transverse Displacement of a Pipeline (vol 46, pg 81, 2009)

引用

SOIL MECHANICS AND FOUNDATION ENGINEERING 2009年第4期46卷 157-157页

作者： Fedorovskii, V. G. N. M. Gersevanov Scientific-Research Institute of Foundations and Underground Structures Moscow Russia

The problem of the limiting resistance of soil to the transverse displacement of a shallow pipeline, which is directed at an arbitrary angle to the horizon, is discussed. The problem is solved by the variational method on the basis of which slip lines in the form of logarithmic spirals, which limit the body of soil uplift onto the surface. Recommendations for practical accounting of the indicated limiting resistance in the form of a two-term formula, tables, and diagrams for calculation of its coefficients are given for the case of a horizontal loading. This solution can, however, be used to determine the bearing capacity of plate anchors used in port construction. The problem of the limiting resistance of a soil to the transverse displacement of a pipe (anchor, pile) in the case of deep embedment, when there is no uplift onto the surface, but “cut through,” is examined separately.

关键词： SOILS logarithmic functions PIPELINES SOIL mechanics ENGINEERING

来源：评论

学校读者我要写书评

暂无评论

Method to reduce the signal-to-noise ratio required for modulation recognition based on logarithmic properties

引用

IET COMMUNICATIONS 2018年第11期12卷 1360-1366页

作者： Xing, Zhe Gao, Yong Sichuan Univ Coll Elect & Informat Engn Chengdu Sichuan Peoples R China

Here, the authors present a novel, simple, and effective way of improving additive white Gaussian noise resistance and reducing the signal-to-noise ratio (SNR) required for modulation recognition. Working on the theoretical basis that the ratio of two logarithmic functions with the same variable is a constant, the authors selected QPSK, 16QAM, and 64QAM for investigation. For each of these, the authors constructed distribution curves of higher-order cumulants, using SNR as the variable, and examined how they might work as logarithmic curves. First, their logarithmic similarities were measured. Then their former features were divided by logarithmic functions to construct new features whose distribution curves were more parallel to the threshold line. Finally, an algorithm for classifying the selected modulation formats was designed whose computational complexity was then compared with that of adaptive-threshold classification algorithm, and the recognition rate was assessed statistically. For the purposes of validation, the algorithm was tested experimentally using actual signals. The experiment confirmed that the new logarithmic features with fixed thresholds were able to maintain an efficient recognition rate of 80% when SNR was reduced from 11 to 6dB, and suffered less computational complexity than traditional cumulants with adaptive thresholds which were achieved by support vector machine.

关键词： AWGN quadrature amplitude modulation signal classification computational complexity quadrature phase shift keying support vector machines higher-order cumulants SNR logarithmic curves logarithmic similarities logarithmic functions distribution curves selected modulation formats computational complexity adaptive-threshold classification algorithm logarithmic features signal-to-noise ratio modulation recognition logarithmic properties additive white Gaussian noise resistance 16QAM 64QAM support vector machine noise figure 6 0 dB to 11 0 dB

来源：评论

学校读者我要写书评

暂无评论

Evolution of fluvial meander-belt deposits and implications for the completeness of the stratigraphic record

引用

GEOLOGICAL SOCIETY OF AMERICA BULLETIN 2018年第5-6期130卷 721-739页

作者： Durkin, Paul R. Hubbard, Stephen M. Holbrook, John Boyd, Ron Univ Calgary Dept Geosci 2500 Univ Dr NW Calgary AB T2N 1N4 Canada Texas Christian Univ Dept Geol Ft Worth TX 76129 USA Univ Newcastle Sch Environm & Life Sci Callaghan NSW 2308 Australia Univ Manitoba Dept Geol Sci 66 Chancellors Circle Winnipeg MB R3T 2N2 Canada

The fragmentary nature of the stratigraphic record is particularly evident with respect to fluvial deposits, which are characterized by a hierarchy of depositional units deposited over a wide range of time scales and sedimentation rates. We quantified stratigraphic completeness in meander-belt deposits through deducing the total area of bar sedimentation versus what is ultimately preserved in the depositional record, using area as a surrogate metric for sediment volume. Data sets were evaluated for a numerical model, the modern Mississippi River valley, and the Cretaceous McMurray Formation. In each data set, the evolutionary history of a series of meander-belt elements was discerned. Migrated area between successive reconstructed paleochannel positions was measured, representing: total area of net bar migration (MA), the area of bar preserved (PA), and percent of bar preserved (PA/MA), at the accretion package, bar, and meander-belt scale. Results of our analysis show that the average preservation percent ranges from 27.3% to 67.8% for an accretion package, 35.0% to 85.1% for a bar, and 38.2% to 67.6% for a meander belt. The processes that lead to a decrease in preservation include intra-meander-bend erosion (due to downstream translation or bar rotation), and increasing meander-bend sinuosity and eventual cutoff (neck and chute), as well as inter-meander-bend erosion due to avulsion and subsequent migration of the meandering channel. The results of this study document a decrease in preservation over time that follows a natural logarithmic function of decay;we have termed this the "survivability" curve. The results presented here document a systematic, monotonic decrease in preservation over time, which is consistent regardless of the spatial or temporal scale and agrees with probabilities of preservation at long time scales proposed by previous workers. A comparison between data sets allows for an estimation of the time span represented by meander-belt deposits in

关键词： logarithmic functions FLUVIAL geomorphology STRATIGRAPHIC geology MONOTONIC functions

来源：评论

学校读者我要写书评

暂无评论

On exponential-logarithmic solutions of linear differential systems with power series coefficients

引用

PROGRAMMING AND COMPUTER SOFTWARE 2015年第2期41卷 112-118页

作者： Ryabenko, A. A. Russian Acad Sci Dorodnicyn Comp Ctr Moscow 119991 Russia

The paper studies construction of formal exponential-logarithmic solutions for a system of ordinary linear differential equations the coefficients of which are algorithmically defined formal power series. The construction of all such solutions is generally algorithmically undecidable problem. We propose an algorithm and its implementation in Maple that make it possible to construct a basis of the space of solutions of the full-rank system if the dimension of this space is known.

关键词： EXPONENTIAL functions logarithmic functions LINEAR differential equations POWER series COEFFICIENTS (Statistics) TRANSCENDENTAL functions

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：