Ambiguous Class Research Articles

Chinese Migration to Lesotho as a Springboard toward a Better Future? The Ambiguous Social Class Positions of Migrants' Children

Chinese Migration to Lesotho as a Springboard toward a Better Future? The Ambiguous Social Class Positions of Migrants' Children

Disagreement based semi-supervised learning approaches with belief functions

In many machine learning tasks, it is usually difficult to obtain enough labeled samples. Semi-supervised learning that exploits unlabeled samples in addition to labeled ones has attracted a lot of research attentions. Traditional semi-supervised methods may encounter uncertainty problems and information loss when dealing with those samples having ambiguous class belongingness. In this paper, the uncertainties encountered in semi-supervised learning are addressed using the theory of belief functions, and semi-supervised learning methods based on belief functions are proposed. The proposed methods label the unlabeled data with belief modeling. They can effectively use limited supervised information to facilitate the classification process. Experimental results based on benchmark data sets show that the proposed approaches can effectively exploit unlabeled data and perform better compared with prevailing approaches.

Learning From Large-Scale Noisy Web Data With Ubiquitous Reweighting for Image Classification.

Many important advances of deep learning techniques have originated from the efforts of addressing the image classification task on large-scale datasets. However, the construction of clean datasets is costly and time-consuming since the Internet is overwhelmed by noisy images with inadequate and inaccurate tags. In this paper, we propose a Ubiquitous Reweighting Network (URNet) that can learn an image classification model from noisy web data. By observing the web data, we find that there are five key challenges, i.e., imbalanced class sizes, high intra-classes diversity and inter-class similarity, imprecise instances, insufficient representative instances, and ambiguous class labels. With these challenges in mind, we assume every training instance has the potential to contribute positively by alleviating the data bias and noise via reweighting the influence of each instance according to different class sizes, large instance clusters, its confidence, small instance bags, and the labels. In this manner, the influence of bias and noise in the data can be gradually alleviated, leading to the steadily improving performance of URNet. Experimental results in the WebVision 2018 challenge with 16 million noisy training images from 5000 classes show that our approach outperforms state-of-the-art models and ranks first place in the image classification task.

Unsupervised SAR Image Segmentation Using Ambiguity Label Information Fusion in Triplet Markov Fields Model

The recently proposed triplet Markov fields (TMF) model enhances the nonstationary image prior modeling ability by introducing an auxiliary field. Motivated by the TMF model, we propose a generalized TMF model based on ambiguity label information fusion (ALF-TMF) for synthetic aperture radar (SAR) image segmentation. The redefined auxiliary field in ALF-TMF indicates the dominant direction of local image contents and gives explicit nonstationary divisions of SAR images. To reduce the influence of unreliable observations caused by speckle noise, the original label field is adaptively generalized by introducing ambiguity class based on image observation and local nonstationary contextual information. Given the extended label field, prior and likelihood terms are constructed and merged to provide the posterior segmentation decision via the Bayesian fusion rule. Real SAR images are utilized in the experimental analysis, and the effectiveness of the proposed method is validated accordingly.

Knowledge Guided Disambiguation for Large-Scale Scene Classification With Multi-Resolution CNNs.

Convolutional neural networks (CNNs) have made remarkable progress on scene recognition, partially due to these recent large-scale scene datasets, such as the Places and Places2. Scene categories are often defined by multi-level information, including local objects, global layout, and background environment, thus leading to large intra-class variations. In addition, with the increasing number of scene categories, label ambiguity has become another crucial issue in large-scale classification. This paper focuses on large-scale scene recognition and makes two major contributions to tackle these issues. First, we propose a multi-resolution CNN architecture that captures visual content and structure at multiple levels. The multi-resolution CNNs are composed of coarse resolution CNNs and fine resolution CNNs, which are complementary to each other. Second, we design two knowledge guided disambiguation techniques to deal with the problem of label ambiguity: 1) we exploit the knowledge from the confusion matrix computed on validation data to merge ambiguous classes into a super category and 2) we utilize the knowledge of extra networks to produce a soft label for each image. Then, the super categories or soft labels are employed to guide CNN training on the Places2. We conduct extensive experiments on three large-scale image datasets (ImageNet, Places, and Places2), demonstrating the effectiveness of our approach. Furthermore, our method takes part in two major scene recognition challenges, and achieves the second place at the Places2 challenge in ILSVRC 2015, and the first place at the LSUN challenge in CVPR 2016. Finally, we directly test the learned representations on other scene benchmarks, and obtain the new state-of-the-art results on the MIT Indoor67 (86.7%) and SUN397 (72.0%). We release the code and models at https://github.com/wanglimin/MRCNN-Scene-Recognition.

Capitulation in the Absolutely Abelian Extensions of some Number Fields II

We study the capitulation of 2-ideal classes of an infinite family of imaginary biquadratic number fields consisting of fields $\mathbb {k} =\mathbb {Q}(\sqrt {pq_{1}q_{2}}, i)$ , where $i=\sqrt {-1}$ and q 1≡q 2≡−p≡−1 (mod 4) are different primes. For each of the three quadratic extensions $\mathbb {K}/\mathbb {k}$ inside the absolute genus field 𝕜 (∗) of 𝕜, we compute the capitulation kernel of $\mathbb {K}/\mathbb {k}$ . Then we deduce that each strongly ambiguous class of $\mathbb {k}/\mathbb {Q}(i)$ capitulates already in 𝕜 (∗).

No general Riemann–Hurwitz formula for relative p-class groups

We disprove, by means of numerical examples and theoretical arguments, illustrated with p=3, the existence of a Riemann–Hurwitz formula for the p-ranks of relative class groups in a p-ramified p-extension K/k of number fields of CM-type containing μp in contradiction with a result published in 1996. In the cyclic case of degree p, under some assumptions on the p-class group of k and the decomposition of the p-places, we prove some results on the structure of the p-class group of K and justify that some theoretical structures do not exist in this particular situation. In this context, an analogue of Kida's formula is valid for the p-ranks if and only if the p-class group of K is reduced to the group of ambiguous classes, which is not always the case, as shown by a numerical table for p=3.

English

We study the capitulation of ideal classes in an infinite family of imaginary bicyclic biquadratic number fields consisting of fields k = Q( √ 2pq, i), where i = √ −1 and p ≡ −q ≡ 1 (mod 4) are different primes. For each of the three quadratic extensions K/k inside the absolute genus field k(∗) of k, we compute the capitulation kernel of K/k. Then we deduce that each strongly ambiguous class of k/Q(i) capitulates already in k(∗), which is smaller than the relative genus field (k/Q(i))∗.

Remarks on the necessity and implications of state-dependence in the black hole interior

We revisit the "state-dependence" of the map that we proposed recently between bulk operators in the interior of a large AdS black hole and operators in the boundary CFT. By refining recent versions of the information paradox, we show that this feature is necessary for the CFT to successfully describe local physics behind the horizon --- not only for single-sided black holes but even in the eternal black hole. We show that state-dependence is invisible to an infalling observer who cannot differentiate these operators from those of ordinary quantum effective field theory. Therefore the infalling observer does not observe any violations of quantum mechanics. We successfully resolve a large class of potential ambiguities in our construction. We analyze states where the CFT is entangled with another system and show that the ER=EPR conjecture emerges from our construction in a natural and precise form. We comment on the possible semi-classical origins of state-dependence.

Guessing, Mind-Changing, and the Second Ambiguous Class

In his dissertation, Wadge defined a notion of guessability on subsets of the Baire space and gave two characterizations of guessable sets. A set is guessable iff it is in the second ambiguous class (boldface Delta^0_2), iff it is eventually annihilated by a certain remainder. We simplify this remainder and give a new proof of the latter equivalence. We then introduce a notion of guessing with an ordinal limit on how often one can change one's mind. We show that for every ordinal alpha, a guessable set is annihilated by alpha applications of the simplified remainder if and only if it is guessable with fewer than alpha mind changes. We use guessability with fewer than alpha mind changes to give a semi-characterization of the Hausdorff difference hierarchy, and indicate how Wadge's notion of guessability can be generalized to higher-order guessability, providing characterizations for boldface Delta^0_alpha for all successor ordinals alpha>1.

Multivalued Dependencies in Fuzzy Multivalued Relational Databases Using Fuzzy Functions

In this paper we discuss an important integrity constraint called multivalued dependency (mvd), which occurs as a result of the first normal form, in the framework of a newly proposed model called fuzzy multivalued relational data model. The fuzzy multivalued relational data model proposed in this paper accommodates a wider class of ambiguities by representing the domain of attributes as a “set of fuzzy subsets”. We show that our model is able to represent multiple types of impreciseness occurring in the real world. To compute the equality of two fuzzy sets/values (which occur as tuple-values), we use the concept of fuzzy functions. So the main objective of this paper is to extend the mvds in context of fuzzy multivalued relational model so that a wider class of impreciseness can be captured. Since the mvds may not exist in isolation, a complete axiomatization for a set of fuzzy functional dependencies (ffds) and mvds in fuzzy multivalued relational schema is provided and the role of fmvds in obtaining the lossless join decomposition is discussed. We also provide a set of sound Inference Rules for the fmvds and derive the conditions for these Inference Rules to be complete. We also derive the conditions for obtaining the lossless join decomposition of a fuzzy multivalued relational schema in the presence of the fmvds. Finally we extend the ABU's Algorithm to find the lossless join decomposition in context of fuzzy multivalued relational databases. We apply all of the concepts of fmvds developed by us to a real world application of “Technical Institute” and demonstrate that how the concepts fit well to capture the multiple types of impreciseness.

ON THE STRONGLY AMBIGUOUS CLASSES OF 𝕜/ℚ(i) WHERE $\mathds{k} = {\mathbb Q}(\sqrt{2p_{1}p_{2}, i})$

We construct an infinite family of imaginary bicyclic biquadratic number fields 𝕜 with the 2-ranks of their 2-class groups are ≥ 3, whose strongly ambiguous classes of 𝕜/ℚ(i) capitulate in the absolute genus field 𝕜(*), which is strictly included in the relative genus field (𝕜/ℚ(i))* and we study the capitulation of the 2-ideal classes of 𝕜 in its quadratic extensions included in 𝕜(*).

John Ashbery’s Free Indirect Labor

The early poems of John Ashbery must be read, in part, as a meditation on the plight of labor, particularly white-collar labor, in the postwar United States. Beginning with a very early poem, “The Instruction Manual” (1956), and its exploration of the ambiguous class position of white-collar workers, the essay tracks themes and formalizations of both labor and management as they continue in Ashbery’s highly experimental second book, The Tennis Court Oath (1962). In this book the standpoint of the earlier poem gives way to an explosion of shifting voices as Ashbery’s distinctive use of free indirect discourse and other techniques of point of view registers the contemporary breakdown in labor relations and the crisis for established modes of management. In Ashbery’s mature style of the 1970s, this chaotic play of voices yields to a comparatively measured technology of point of view, which reflects the new modes of management that followed the crises of the 1960s and 1970s.

Holonomy operator and quantization ambiguities on spinor space

We construct the holonomy-flux operator algebra in the recently developed spinor formulation of loop gravity. We show that, when restricting to SU(2)-gauge invariant operators, the familiar grasping and Wilson loop operators are written as composite operators built from the gauge-invariant ``generalized ladder operators'' recently introduced in the $\mathrm{U}(N)$ approach to intertwiners and spin networks. We comment on quantization ambiguities that appear in the definition of the holonomy operator and use these ambiguities as a toy model to test a class of quantization ambiguities which is present in the standard regularization and definition of the Hamiltonian constraint operator in loop quantum gravity.

Realism and the Irish Immigrant: Documentary, Fiction, and Postwar Irish Labor

Irish realism of the 1960s has often been interpreted as a continuation and rejuvenation of the tradition of Irish naturalism, particularly in its concern to undermine the perceived romanticism of revivalist myths in postindependence Ireland. While Irish realist social critique was indeed an important strand of 1960s fiction, especially in the work of John McGahern, this essay argues that it was cross-fertilized by other realist narrative modes, including British documentary writing of the 1950s and 1960s. The Irish New Wave, however, differs in important respects from its British counterpart. Irish fiction registers the ambiguous class position of the Irish in Britain, and narrative strategies common to working-class realist texts, such as the delineation of the relationship between place and community and the representation of social mobility, proved inadequate for articulating lives lived within the Irish community in Britain. Focusing on the figure of the male laborer as represented in contemporary sociological texts and in the work of Donall Mac Amhlaigh and Tom Murphy, the essay examines the development of contrasting narratives of class and community informed both by traditional Irish discourses of emigration and by newly emergent documentary realism.

Infinite class of new sign ambiguities

In 1934, two kinds of multiplicative relations, the norm and the Davenport–Hasse relations, between Gauss sums, were known. In 1964, H. Hasse conjectured that the norm and the Davenport–Hasse relations were the only multiplicative relations connecting Gauss sums over F p . However, in 1966, K. Yamamoto provided a simple counterexample disproving the conjecture. This counterexample was a new type of multiplicative relation, called a sign ambiguity, involving a ± sign not connected to elementary properties of Gauss sums. In this paper, we give an explicit product formula involving Gauss sums which generates an infinite class of new sign ambiguities, and we resolve the ambiguous sign by using Stickelbergerʼs theorem.

Near broke, but no tramp: Billie Ritchie, Charlie Chaplin and ‘that costume’

This article revisits the various claims and counter‐claims that have been made over the years as to whether the 1910s music hall comedian turned slapstick film star Billie Ritchie stole his costume and comic persona from Charlie Chaplin, or was himself the victim of plagiarism on Chaplin’s part. It proposes that neither of these arguments can be definitively supported on the basis of evidence available in the public domain, but also draws attention to the fact that there are other factors in play that may plausibly explain the various similarities between the two comedians as the result of shared formative influences rather than outright imitation, and that some contemporaries deemed it eminently reasonable to take such a view. The article moves on to consider the significance of the fact that, although their costumes were practically identical, Ritchie typically played dissolute gentlemen of ambiguous class status rather than tramps. It concludes that there is a stronger argument to be made that, rather than seeking to represent vagrancy, both Chaplin and Ritchie originally used the iconic ‘tramp’ costume to poke fun at the culturally ubiquitous Edwardian figure of the ‘masher’ – a lower‐middle‐ or working‐class male pleasure‐seeker trying (and in their incarnations, failing) to emulate the fashions of his social superiors.

Markoff numbers and ambiguous classes

La conjecture de Markoff dit qu’étant donné un entier positif c il existe au plus un triplet (a,b,c) d’entiers positifs tels que a≤b≤c et satisfaisant l’équation a 2 +b 2 +c 2 =3abc. La conjecture est vraie pour c une puissance d’un nombre premier ou deux fois une puissance d’un nombre premier. Nous présentons une preuve élémentaire de ce résultat. Nous montrons également que si, dans le groupe des classes des formes de discriminant d=9c 2 -4, toute forme ambige dans le genre principal correspond à un diviseur de 3c-2 alors la conjecture est vraie. Comme conséquence, nous obtenons un critère, en termes de symboles de Legendre des premiers divisant d, pour lequel la conjecture est vraie. Nous énonçons également une conjecture pour le corps quadratique ℚ(9c 2 -4) qui est équivalente à la conjecture de Markoff pour c.

Chevalley’s ambiguous class number formula for an arbitrary torus

In this paper we obtain Chevalley's ambiguous class number formula for an arbitrary torus $T$ over a global field. The classical formula of C.Chevalley may be recovered by setting $T=\bg_{m}$ in our formula. A key ingredient of the proof is the work of X.Xarles on groups of components of N\'eron-Raynaud models of tori.

Soft SVM and Its Application in Video-Object Extraction

As a requisite of content-based multimedia technologies, video-object (VO) extraction is a very important yet challenging task. In recent years, classification-based approaches have been proposed to handle VO extraction as a classification problem, for which some promising results have been reported using adaptive neural networks and support vector machines (SVMs). We observe that some training samples in video sequences exhibit partial or ambiguous class memberships, which does not comply with standard membership setups. This problem is addressed in the context of SVM in this paper. By reformulating SVM for the noncrisp classification scenario, we propose a machine which is capable of dealing with binary (or hard) as well as real-valued (or soft) class memberships. The new machine, which is named Soft SVM, is integrated into a VO extraction method, and its effectiveness is demonstrated by the experimental results.