The heavy-tailed distributions of corrupted outliers and singular values of all channels in low-level vision have proven effective priors for many applications such as background modeling, ...photometric stereo and image alignment. And they can be well modeled by a hyper-Laplacian. However, the use of such distributions generally leads to challenging non-convex, non-smooth and non-Lipschitz problems, and makes existing algorithms very slow for large-scale applications. Together with the analytic solutions to <inline-formula><tex-math notation="LaTeX">\ell _{p}</tex-math> <inline-graphic xlink:href="shang-ieq1-2748590.gif"/> </inline-formula>-norm minimization with two specific values of <inline-formula><tex-math notation="LaTeX">p</tex-math> <inline-graphic xlink:href="shang-ieq2-2748590.gif"/> </inline-formula>, i.e., <inline-formula> <tex-math notation="LaTeX">p=1/2</tex-math> <inline-graphic xlink:href="shang-ieq3-2748590.gif"/> </inline-formula> and <inline-formula><tex-math notation="LaTeX">p=2/3</tex-math> <inline-graphic xlink:href="shang-ieq4-2748590.gif"/> </inline-formula>, we propose two novel bilinear factor matrix norm minimization models for robust principal component analysis. We first define the double nuclear norm and Frobenius/nuclear hybrid norm penalties, and then prove that they are in essence the Schatten-<inline-formula> <tex-math notation="LaTeX">1/2</tex-math> <inline-graphic xlink:href="shang-ieq5-2748590.gif"/> </inline-formula> and <inline-formula><tex-math notation="LaTeX">2/3</tex-math> <inline-graphic xlink:href="shang-ieq6-2748590.gif"/> </inline-formula> quasi-norms, respectively, which lead to much more tractable and scalable Lipschitz optimization problems. Our experimental analysis shows that both our methods yield more accurate solutions than original Schatten quasi-norm minimization, even when the number of observations is very limited. Finally, we apply our penalties to various low-level vision problems, e.g., text removal, moving object detection, image alignment and inpainting, and show that our methods usually outperform the state-of-the-art methods.
Abstract
Contestation of international norms has become the new focus of IR norm research. The optimism of the 1990s that fundamental liberal norms would diffuse globally has remained unfulfilled in ...recent years—even human rights norms have witnessed strong contestation. Time and again, controversy has erupted regarding international norms such as the ban on torture or the Responsibility to Protect. Meanwhile, we know little about how such controversy affects the robustness of norms—whether it contributes to their weakening or to their strengthening. Existing research offers two competing hypotheses: One branch of norm research often conceptualizes contestation as a sign of norm weakening. By contrast, another branch assigns contestation a normative power of its own, which strengthens norms. It does not specify the limits of such normative power, however. In this article, we argue that contestation per se is a poor predictor of norm robustness. The type of contestation a norm faces matters. Contestation can either (1) address the dimension of application of a norm or (2) examine its validity by questioning the righteousness of the claims a norm makes. The article draws on two illustrative case studies of extensively contested norms, the Responsibility to Protect and the ban on commercial whaling. We argue that widespread contestation of the very validity of a norm is likely to lead to a loss of norm robustness. Applicatory contestation, by contrast, can—under specific circumstances—even strengthen it.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, ODKLJ, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Previous studies have found that social norms affect eating behavior for different types of social norm measures and manipulations as well as different types of eating behavior. The current study ...investigated the effects of descriptive, injunctive, and liking norms on intentions to consume healthy snacks and anticipated snack choice, compared to a no-norm control condition. Moreover, we distinguished between descriptive norms that stress the frequency versus the quantity of food consumption. An experiment was conducted among 189 young adults. It was hypothesized that participants who received a descriptive quantity or frequency norm would intend to consume, and make an anticipated selection of, more low-calorie snacks than participants who received a no-norm control message. Due to inconsistency or lacking evidence regarding the effects of the other types of norms on eating behavior, no hypotheses were formulated for the injunctive and liking norm conditions. The hypothesis was partly confirmed. Descriptive quantity and frequency norms did not result in a stronger intention to consume healthy snacks in the upcoming week, but they did result in lower-calorie snack choices when people were asked to select three snacks that they planned to eat on the following day. No other differences between the conditions were found. These findings show that emphasizing both how much and how often most other people consume healthy foods affects anticipated healthy food choices. This can provide health professionals more options to mobilize the power of descriptive social norms for affecting health behavior change.
The article under studies deals with the peculiarities of argumentative triallism of norms (the division of the so-called fundamental legal norms into law-justifying and two types of law-negating ...norms in classical, standard, and derivative relational technique) in the process of functioning of relational technique, within written and oral litigation, as well as within the formation of an expertise style of processing a legal case. The possibility of applying argumentative normotrialism within the framework of constitutional norm-making is indicated. The article assumes that in classical relational technique, argumentative triallism of norms might rely on the action-legal thinking, which suggests the division of legal means into claims and objections, the latter generally being classified as absolute and relative ones. It is important that within standard relational technique (also known as the technique of H. Daubenspeck and his disciples), argumentative triallism of norms could have been related to the formation of pandect law in the XIX century, namely, to the textbook on pandect law by B. Windscheid. The latter may be regarded as the founder of argumentative triallism of norms in the modern sense. In any case, standard relational technique rests on the idea of argumentative triallism of norms from the very beginning and up to this day, especially when it comes to an expertise opinion (votum) or, as it is now commonly said, a working technique. Particular emphasis has been laid on the fact that argumentative triallism of norms is of great importance in derivative relational technique. In the expertise style of processing a legal case, it performs a pure function of a plan for elaborating an expertise opinion, which is a simplified version of an expertise opinion (votum) and is based on standard relational technique. The point is that an expertise opinion in derivative relational technique is consistently drawn up as follows: first, the law-justifying norms are analyzed, then - absolute law-negating rules, and, finally, - relative law-negating norms. Argumentative triallism of norms is one of the keys to the potential adoption of post-classical (standard and derivative) relational technique.
Green IT, a future-oriented and pro-environmental information technology, is an emerging trend in IT. In Green IT acceptance, the norms of environmental responsibility are considered to be important ...factors along with economic factors such as perceived usefulness of the Technology Acceptance Model (TAM). This study proposes a technology acceptance model for Green IT by adding normative variables (descriptive, injunctive, and personal norms) to Davis's TAM and empirically analyzes the model. Our results indicate that personal norms, descriptive norms (a type of social norms), and environmental beliefs as well as perceived usefulness can directly affect an individual's intention to use Green IT. In addition, government regulations and environmental beliefs have significant effects on normative variables. These findings imply that pro-environmentalism of Green IT is an important boundary condition for the validity of the TAM.
•The TAM for Green IT is proposed with normative variables.•Personal norms affect an individual's intention to use Green IT.•Descriptive norms affect an individual's intention to use Green IT.•Environmental beliefs affect an individual's intention to use Green IT.
This article studies the parameter tuning problem of positive linear systems for optimizing their stability properties. We specifically show that, under certain regularity assumptions on the ...parameterization, the problem of finding the minimum-cost parameters that achieve a given requirement on a system norm reduces to a geometric program , which, in turn, can be exactly and efficiently solved by convex optimization. The flexibility of geometric programming allows the state, input, and output matrices of the system to simultaneously depend on the parameters to be tuned. The class of system norms under consideration includes the <inline-formula><tex-math notation="LaTeX">H^2</tex-math></inline-formula> norm, <inline-formula><tex-math notation="LaTeX">H^\infty</tex-math></inline-formula> norm, Hankel norm, and Schatten <inline-formula><tex-math notation="LaTeX">p</tex-math></inline-formula>-norm. Also, the parameter tuning problem for ensuring the robust stability of the system under structural uncertainties is shown to be solved by geometric programming. The proposed optimization framework is further extended to delayed positive linear systems, where it is shown that the parameter tuning problem jointly constrained by the exponential decay rate, the <inline-formula><tex-math notation="LaTeX">\mathcal L^1</tex-math></inline-formula>-gain, and the <inline-formula><tex-math notation="LaTeX">\mathcal L^\infty</tex-math></inline-formula>-gain can be solved by convex optimization. The assumption on the system parameterization is stated in terms of posynomial functions, which form a broad class of functions and thus allow us to deal with various interesting positive linear systems arising from, for example, dynamical buffer networks and epidemic spreading processes. We present numerical examples to illustrate the effectiveness of the proposed optimization framework.
In this paper, we introduce the notion of (k)-triangular norms and present a new classification of triangular norms (t-norms for short) splitting the set T of all t-norms into an infinite countable ...partition {T1⁎,T2⁎,…}∪{T⁎}. From the four basic t-norms, the minimum TM is the unique member of T1⁎, the drastic product TD belongs to T2⁎, the product TP and also the Łukasiewicz t-norm TL are members of T⁎. We show that t-norms from Tk⁎ are always (k+1)-contractive, but not vice-versa. We also provide some necessary and some sufficient conditions for t-norms to be (proper) (k)-t-norms. In the end, we give several examples and construction methods for t-norms belonging to particular classes of the proposed partition or to the set Tk=⋃i=1kTi⁎.
Social norms are critical drivers of pro-environmental behaviours (PEBs) yet vary in their influences across individuals or cultures. This study investigates the contingent effects of social norms on ...tourists' PEBs by examining the moderating role of an individual cultural value, i.e. Confucian-based Chinese traditionality, on the mediated relations via personal norm. Using survey data collected from Kulansu island and with structural equation modelling and bootstrap analyses, it revealed that both injunctive and descriptive norms did not exert a direct effect on tourists' PEBs but an indirect one via personal norm, i.e. personal norm fully mediated the relationship between social norms and PEBs. It also confirmed that Chinese traditionality moderated the mediated relationship between injunctive, but not descriptive, norm and PEBs through personal norm, such that the mediation was stronger for tourists higher, rather than lower, in Chinese traditionality. This study contributes to the literature on the norm-behaviour relationship in a Confucian-based cultural context and offers practical insights into crafting normative appeals in environmental campaigns.
Social norms are the glue that holds society together, yet our knowledge of them remains heavily intellectually siloed. This article provides an interdisciplinary review of the emerging field of norm ...dynamics by integrating research across the social sciences through a cultural-evolutionary lens. After reviewing key distinctions in theory and method, we discuss research on norm psychology-the neural and cognitive underpinnings of social norm learning and acquisition. We then overview how norms emerge and spread through intergenerational transmission, social networks, and group-level ecological and historical factors. Next, we discuss multilevel factors that lead norms to persist, change, or erode over time. We also consider cultural mismatches that can arise when a changing environment leads once-beneficial norms to become maladaptive. Finally, we discuss potential future research directions and the implications of norm dynamics for theory and policy.
Nuclear norm of higher-order tensors FRIEDLAND, SHMUEL; LIM, LEK-HENG
Mathematics of computation,
05/2018, Letnik:
87, Številka:
311
Journal Article
Recenzirano
Odprti dostop
We establish several mathematical and computational properties of the nuclear norm for higher-order tensors. We show that like tensor rank, tensor nuclear norm is dependent on the choice of base ...field; the value of the nuclear norm of a real 3-tensor depends on whether we regard it as a real 3-tensor or a complex 3-tensor with real entries. We show that every tensor has a nuclear norm attaining decomposition and every symmetric tensor has a symmetric nuclear norm attaining decomposition. There is a corresponding notion of nuclear rank that, unlike tensor rank, is lower semicontinuous. We establish an analogue of Banach's theorem for tensor spectral norm and Comon's conjecture for tensor rank; for a symmetric tensor, its symmetric nuclear norm always equals its nuclear norm. We show that computing tensor nuclear norm is NP-hard in several ways. Deciding weak membership in the nuclear norm unit ball of 3-tensors is NP-hard, as is finding an \varepsilon -approximation of nuclear norm for 3-tensors. In addition, the problem of computing spectral or nuclear norm of a 4-tensor is NP-hard, even if we restrict the 4-tensor to be bi-Hermitian, bisymmetric, positive semidefinite, nonnegative valued, or all of the above. We discuss some simple polynomial-time approximation bounds. As an aside, we show that computing the nuclear (p,q)-norm of a matrix is NP-hard in general but polynomial-time if p=1, q = 1, or p=q=2, with closed-form expressions for the nuclear (1,q)- and (p,1)-norms.
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