Parameterizing cut sets in a graph by the number of their components

For a connected graph G=(V,E), a subset U⊆V is a disconnected cut if U disconnects G and the subgraph G[U] induced by U is disconnected as well. A cut U is a k-cut if G[U] contains exactly k(≥1) components. More specifically, a k-cut U is a (k,?)-cut if V?U induces a subgraph with exactly ?(≥2) components. The Disconnected Cut problem is to test whether a graph has a disconnected cut and is known to be NP-complete. The problems k-Cut and (k,?)-Cut are to test whether a graph has a k-cut or (k,?)-cut, respectively. By pinpointing a close relationship to graph contractibility problems we show that (k,?)-Cut is in P for k=1 and any fixed constant ?≥2, while it is NP-complete for any fixed pair k,?≥2. We then prove that k-Cut is in P for k=1 and NP-complete for any fixed k≥2. On the other hand, for every fixed integer g≥0, we present an FPT algorithm that solves (k,?)-Cut on graphs of Euler genus at most g when parameterized by k+?. By modifying this algorithm we can also show that k-Cut is in FPT for this graph class when parameterized by k. Finally, we show that Disconnected Cut is solvable in polynomial time for minor-closed classes of graphs excluding some apex graph.     

Parameterizing neural networks for disease classification

Neural networks are one option to implement decision support systems for health care applications. In this paper, we identify optimal settings of neural networks for medical diagnoses: The study involves the application of supervised machine learning using an artificial neural network to distinguish between gout and leukaemia patients. With the objective to improve the base accuracy (calculated from the initial set-up of the neural network model), several enhancements are analysed, such as the use of hyperbolic tangent activation function instead of the sigmoid function, the use of two hidden layers instead of one, and transforming the measurements with linear regression to obtain a smoothened data set. Another setting we study is the impact on the accuracy when using a data set of reduced size but with higher data quality. We also discuss the tradeoff between accuracy and runtime efficiency.     

Balancing Load versus Decreasing Communication: Parameterizing the Tradeoff

Mesh partitioning is an important step for parallel scientific applications, in particular finite element analyses. A good partitioner will minimize both the time spent on local computation and on interprocessor communication. It is often the case that these two goals cannot be satisfied simultaneously. In this paper, we use analytical and experimental results to illustrate the importance of considering the target architecture as well as the application when determining which factor to emphasize in a partitioning method. In particular, we derive a parameter η₀ that provides some guidelines as to which goal should be given primary focus. Our results yield two interesting facts: (1) allowing some load imbalance can provide some reduction in communication and total execution times and (2) as larger numbers of processors are applied to a problem, larger amounts of load imbalance are beneficial.     

服装CAD中三维人体模型的参数化研究

针对三角网格曲面表示的3D人体模型缺少语义信息,提出一种3D人体模型的参数化方法：首先通过三角面片求交的采样策略得到采样点,然后使用B样条曲线构造人体轮廓线,最后由用户交互得到3D人体模型的参数化信息,建立3D人体模型的参数化模板．这样,在参数化人体模型模板的基础上,可以根据用户所输入的特定人体参数信息,动态地调整轮廓线和重建人体模型体表曲面,快速生成逼真的3D人体模型,从而满足服装CAD中根据用户身材尺寸大小定制服装的应用需求．     

Adding Large Numbers by Computer

Cyberneticians are often confronted with very large numbers. Already when relatively small sets of objects, states or attributes are considered, the enumeration of their possible permutations, orderings, relations, patterns, partitions, etc. quickly exceeds astronomical values. This fact has been demonstrated by Ashby [1] who suggested to call numbers larger than 10¹⁰⁰ combinatorial numbers.     

Parameterizing lexical conceptual structure for interlingual machine translation

Conclusion this is an interesting and informative book with much to recommend it. It covers a great deal of ground in discussion of ideas and presentation of an actual implementation, but I believe the major contribution to be in four areas:- In presenting a system whose syntax is based on principles and parameters, Dorr provides an interesting challenge to the standard rule-based approaches which are broadly unification-based.- Dorr presents an interlingua which appears to have relatively solid linguistic motivation, and for which there is a very systematic mapping to and from text. This directly addresses two of the standard objections to interlingual approaches: arbitrariness and lack of systematicity. Unfortunately, the range of phenomena she considers is too limited to address the other major objection that is normally raised in relation to interlingual approaches: that of lack of coverage.- Dorr presents a classification of translation divergences. I believe such a classification to be worthwhile, and I take this is a useful beginning. However, I find the actual classification proposed too broad, and theory-dependent. Moreover Dorr's claims about completeness of the classification are not convincing.- Dorr presents a solution to various translation divergences via parameterization of the interlingual representation. Here I believe reservations about conceptual coherence of the representation and the generality of the approach are appropriate.I am grateful to Harold Somers and Bonnie Dorr for criticisms and corrections of an earlier version. Of course, the remaining deficiencies are entirely my fault.     

Near-optimal parameterization of the intersection of quadrics: III. Parameterizing singular intersections

We conclude, in this third part, the presentation of an algorithm for computing an exact and proper parameterization of the intersection of two quadrics. The coordinate functions of the parameterizations in projective space are polynomial, whenever it is possible. They are also near-optimal in the sense that the number of distinct square roots appearing in the coefficients of these functions is minimal except in a small number of cases (characterized by the real type of the intersection) where there may be an extra square root.     

Parameterizing residential water demand pulse models through smart meter readings

This paper proposes a method for parameterizing the Poisson models for residential water demand pulse generation, which consider the dependence of pulse duration and intensity. The method can be applied to consumption data collected in households through smart metering technologies. It is based on numerically searching for the model parameter values associated with pulse frequencies, durations and intensities, which lead to preservation of the mean demand volume and of the cumulative trend of demand volumes, at various time aggregation scales at the same time. The method is applied to various case studies, by using two time aggregation scales for demand volumes, i.e. fine aggregation scale (1 min or 15 min) and coarse aggregation scale (1 day). The fine scale coincides with the time resolution for reading acquisition through smart metering whereas the coarse scale is obtained by aggregating the consumption values recorded at the fine scale.Results show that the parameterization method presented makes the Poisson model effective at reproducing the measured demand volumes aggregated at both time scales. Consistency of the pulses improves as the fine scale resolution increases.     

Bounding the Vapnik-Chervonenkis Dimension of Concept Classes Parameterized by Real Numbers

The Vapnik-Chervonenkis (V-C) dimension is an important combinatorial tool in the analysis of learning problems in the PAC framework. For polynomial learnability, we seek upper bounds on the V-C dimension that are polynomial in the syntactic complexity of concepts. Such upper bounds are automatic for discrete concept classes, but hitherto little has been known about what general conditions guarantee polynomial bounds on V-C dimension for classes in which concepts and examples are represented by tuples of real numbers. In this paper, we show that for two general kinds of concept class the V-C dimension is polynomially bounded in the number of real numbers used to define a problem instance. One is classes where the criterion for membership of an instance in a concept can be expressed as a formula (in the first-order theory of the reals) with fixed quantification depth and exponentially-bounded length, whose atomic predicates are polynomial inequalities of exponentially-bounded degree, The other is classes where containment of an instance in a concept is testable in polynomial time, assuming we may compute standard arithmetic operations on reals exactly in constant time.Our results show that in the continuous case, as in the discrete, the real barrier to efficient learning in the Occam sense is complexity-theoretic and not information-theoretic. We present examples to show how these results apply to concept classes defined by geometrical figures and neural nets, and derive polynomial bounds on the V-C dimension for these classes.     

Parameterizing the aerodynamic roughness length on a regional scale based on multi-source remote-sensing data

Aerodynamic roughness length (z₀) is one of those important biophysical parameters that influence energy exchange at the land–atmosphere interface, so it is significant to quantify the z₀ accurately. In this article, a scheme parameterizing land-surface z₀ at regional scale has been approached based on multi-resource remote-sensing data, including lidar and optical remote sensing. First, we retrieved the regional vegetation height from lidar data of Geoscience Laser Altimeter System (GLAS) on board the Ice, Cloud, and land Elevation Satellite (ICESat), and then the z₀ values of vegetated land surface were calculated using height data and canopy area index retrieved from remote-sensing data. Finally, the wall-to-wall map of z₀ in January and July 2008 were developed. The conclusions are as follows. (1) The vertical and horizontal structures of vegetation can be retrieved combining spaceborne lidar data and other optical remote-sensing data, so the vegetation characteristics and their intra-annual diversification of different land surfaces can be presented dynamically. The variation of z₀ with vegetation phenology can be quantified by modelling with vegetation height and multi-temporal leaf area index from multi-resource remote-sensing data. (2) The z₀ values of vegetated surface change significantly during leaf-on or leaf-off period in the year, but there are different features in the sparsely or densely vegetated surface. In the sparse vegetation areas, due to the relatively low leaf density in leaf-off season, the value of z₀ is also low. With the increase of leaf density in leaf-on season, the z₀ values will also increase. However, the relationship is complicated in the dense vegetation areas in leaf-on season; the z₀ values may or may not increase, but the zero-plane displacement heights will keep increasing continuously. This operational scheme to parameterize z₀ based on the vegetation height and canopy area index retrieved from multi-source remote-sensing data can be applied to quantify time serial z₀ at regional scale. Besides, it can also improve z₀ parameterization in land models or atmospheric models.     

ShapeSynth: Parameterizing model collections for coupled shape exploration and synthesis

Recent advances in modeling tools enable non‐expert users to synthesize novel shapes by assembling parts extracted from model databases. A major challenge for these tools is to provide users with relevant parts, which is especially difficult for large repositories with significant geometric variations. In this paper we analyze unorganized collections of 3D models to facilitate explorative shape synthesis by providing high‐level feedback of possible synthesizable shapes. By jointly analyzing arrangements and shapes of parts across models, we hierarchically embed the models into low‐dimensional spaces. The user can then use the parameterization to explore the existing models by clicking in different areas or by selecting groups to zoom on specific shape clusters. More importantly, any point in the embedded space can be lifted to an arrangement of parts to provide an abstracted view of possible shape variations. The abstraction can further be realized by appropriately deforming parts from neighboring models to produce synthesized geometry. Our experiments show that users can rapidly generate plausible and diverse shapes using our system, which also performs favorably with respect to previous modeling tools.     

Underflow and the Denormalized Numbers

Although there have been misconceptions about it, gradual underflow fits naturally into the proposed standard and leads to simple, general statements about the arithmetic.     

微波谐振腔模式数的程序求解法

微波谐振腔在无线通信领域应用广泛。在简要微波谐振腔的基础上,给出了用程序求解谐振模式数的方法,并利用C++实现了对给定尺寸矩形谐振腔模式数的求解。     

Fibonacci数和Lucas数的联合迭代算法

针对超大Fibonacci数和Lucas数的计算问题,提出一种Fibonacci-Lucas数联合迭代算法,在单次循环中选择二倍步长的方式,采用交替计算Fibonacci数和Lucas数的方法,减低超大数迭代算式的复杂度,提高程序的计算效率。实验结果表明,该算法运行时间比现有的矩阵迭代算法更短。     

Condition Numbers of the Generalized Sylvester Equation

This note is devoted to the perturbation analysis for the generalized Sylvester equations (AX-YB, DX-YE)= (C, F), which have some important applications in control and system theory. Expressions and upper bounds for normwise, mixed, and componentwise condition numbers are presented. The results are illustrated by numerical examples.