scholarly journals Robust Universal Inference

Entropy ◽  
2021 ◽  
Vol 23 (6) ◽  
pp. 773
Author(s):  
Amichai Painsky ◽  
Meir Feder
Keyword(s):  
Robust Estimation ◽  
Minimax Estimator ◽  
Worst Case ◽  
Capacity Theory ◽  
Alternative Approach ◽  
True Model ◽  
Finite Set ◽  
Universal Prediction ◽  
Estimation Scheme

Learning and making inference from a finite set of samples are among the fundamental problems in science. In most popular applications, the paradigmatic approach is to seek a model that best explains the data. This approach has many desirable properties when the number of samples is large. However, in many practical setups, data acquisition is costly and only a limited number of samples is available. In this work, we study an alternative approach for this challenging setup. Our framework suggests that the role of the train-set is not to provide a single estimated model, which may be inaccurate due to the limited number of samples. Instead, we define a class of “reasonable” models. Then, the worst-case performance in the class is controlled by a minimax estimator with respect to it. Further, we introduce a robust estimation scheme that provides minimax guarantees, also for the case where the true model is not a member of the model class. Our results draw important connections to universal prediction, the redundancy-capacity theorem, and channel capacity theory. We demonstrate our suggested scheme in different setups, showing a significant improvement in worst-case performance over currently known alternatives.

scholarly journals Chemical and Biological Molecules Involved in Differentiation, Maturation, and Survival of Dopaminergic Neurons in Health and Parkinson’s Disease: Physiological Aspects and Clinical Implications

Biomedicines ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 754
Author(s):  
Giulia Gaggi ◽  
Andrea Di Credico ◽  
Pascal Izzicupo ◽  
Giovanni Iannetti ◽  
Angela Di Baldassarre ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Dopaminergic Neurons ◽  
Potential Role ◽  
High Efficiency ◽  
Biological Molecules ◽  
Alternative Approach ◽  
Non Coding Rnas ◽  
Set Up

Parkinson’s disease (PD) is one of the most common neurodegenerative disease characterized by a specific and progressive loss of dopaminergic (DA) neurons and dopamine, causing motor dysfunctions and impaired movements. Unfortunately, available therapies can partially treat the motor symptoms, but they have no effect on non-motor features. In addition, the therapeutic effect reduces gradually, and the prolonged use of drugs leads to a significative increase in the number of adverse events. For these reasons, an alternative approach that allows the replacement or the improved survival of DA neurons is very appealing for the treatment of PD patients and recently the first human clinical trials for DA neurons replacement have been set up. Here, we review the role of chemical and biological molecules that are involved in the development, survival and differentiation of DA neurons. In particular, we review the chemical small molecules used to differentiate different type of stem cells into DA neurons with high efficiency; the role of microRNAs and long non-coding RNAs both in DA neurons development/survival as far as in the pathogenesis of PD; and, finally, we dissect the potential role of exosomes carrying biological molecules as treatment of PD.

scholarly journals “Incompleteness” and the Quest for Multiple Identities in South Africa

2015 ◽  
Vol 50 (3) ◽  
pp. 81-107 ◽  
Author(s):  
Bernard C. Lategan
Keyword(s):  
South Africa ◽  
Cultural Diversity ◽  
Identity Formation ◽  
Social Cohesion ◽  
Historical Memory ◽  
Multiple Identities ◽  
The Self ◽  
Important Goal ◽  
Alternative Approach

The article explores the contours of multiple identities in contrast to singular identities in situations of social complexity and cultural diversity. Nyamnjoh's concepts of “incompleteness” and “frontier Africans” imply an alternative approach to identity formation. Although the formation of one's own, singular identity is a necessary stage in the development of each individual, it has specific limitations. This is especially true in situations of complexity and diversity and where the achievement of social cohesion is an important goal. With reference to existing theories of identity formation, an alternative framework is proposed that is more appropriate for the dynamic, open-ended nature of identity and better suited to encourage the enrichment of identity. The role of imagination, a strategy for crossing borders (with reference to Clingman's concept of a “grammar of identity”), the search for commonality, and the effect of historical memory are discussed. Enriched and multiple identities are not achieved by replacement or exchange, but by widening (existing) singular identities into a more inclusive and diverse understanding of the self.

scholarly journals Monitoring dispersive samples with single photons: the role of frequency correlations

2017 ◽  
Vol 4 (1) ◽  
Author(s):  
Emanuele Roccia ◽  
Marco G. Genoni ◽  
Luca Mancino ◽  
Ilaria Gianani ◽  
Marco Barbieri ◽  
...  
Keyword(s):  
Degrees Of Freedom ◽  
Simultaneous Estimation ◽  
Single Photons ◽  
Estimation Scheme ◽  
Correlation Parameters ◽  
Two Parameters ◽  
Quantum Limits ◽  
Cramer Rao Bound ◽  
Down Conversion

AbstractThe physics that governs quantum monitoring may involve other degrees of freedom than the ones initialised and controlled for probing. In this context we address the simultaneous estimation of phase and dephasing characterizing a dispersive medium, and we explore the role of frequency correlations within a photon pair generated via parametric down-conversion, when used as a probe for the medium. We derive the ultimate quantum limits on the estimation of the two parameters, by calculating the corresponding quantum Cramér-Rao bound; we then consider a feasible estimation scheme, based on the measurement of Stokes operators, and address its absolute performances in terms of the correlation parameters, and, more fundamentally, of the role played by correlations in the simultaneous achievability of the quantum Cramér- Rao bounds for each of the two parameters.

A Robust Method for Parameter Estimation from Catch and Effort Data

1989 ◽  
Vol 46 (1) ◽  
pp. 137-144 ◽  
Author(s):  
D. Ludwig ◽  
C. J. Walters
Keyword(s):  
Parameter Estimation ◽  
Robust Estimation ◽  
Robust Method ◽  
Amount Of Information ◽  
Surplus Production ◽  
Production Models ◽  
Composite Estimation ◽  
Estimation Scheme

The problem of robust estimation of optimal effort levels from surplus production models is considered. A variety of models are used to generate data, for the purpose of testing estimation schemes. The result of an estimation is an estimate of the optimal effort. These efforts are compared using the expected discounted value of a deterministic stock, which corresponds to the model used to generate the data. Such a criterion takes into account not only the loss due to bias in the estimated optimal effort, but also the loss due to the variance of the estimator. Estimation is difficult if there is a lack of informative variation in effort levels or stock sizes. In such cases, the estimation scheme which maximizes the criterion described above sacrifices realism in the representation of the stock-production relationship in order to reduce the variance of the estimate of optimal effort. We present a composite estimation scheme which performs acceptably in all the cases we have examined, and whose performance degrades slowly as the amount of information in the data decreases.

Corporate (Non-)Accountability and Human Rights

2018 ◽  
Vol 46 (4-5) ◽  
pp. 503-523
Author(s):  
Stéfanie Khoury
Keyword(s):  
Human Rights ◽  
Global Economy ◽  
Codes Of Conduct ◽  
Washington Consensus ◽  
Corporate Accountability ◽  
Criminal Courts ◽  
Race To The Bottom ◽  
Alternative Approach ◽  
Binding Mechanisms

Abstract The role of business in violations of human rights has been at the heart of international debates for decades. As early as the 1970s attempts were made at the UN by Global South nations (known as the G-77) to establish internationally-binding mechanisms to address corporate violations of human rights. Ultimately, those attempts were watered down into “codes of conduct”. In the early 1990s, the “Washington Consensus” was used to steer states to deregulate and restructure their economies in a race-to-the-bottom that placed emphasis upon integrating the global economy over human rights and environmental protections. Although corporate violations existed before, it was only at this juncture that many human rights cases were brought into public view. Some litigation was pursued, but it was most often in tort, and sometimes in criminal courts. This article argues that the existing regional human rights courts have bolstered corporate human rights, while at the same time have remained on the sidelines of addressing corporate accountability. The emergent ASEAN human rights system has not yet developed a human rights court. The article suggests that there are key grassroots movements shaping human rights discourses around corporate accountability through the region and that these offer exciting prospects for an alternative approach to addressing corporate accountability through a prospective supervisory mechanism.

South Africa at a Turning Point?

2015 ◽  
Vol 53 (3) ◽  
pp. 477-486 ◽  
Author(s):  
Elke Zuern
Keyword(s):  
South Africa ◽  
Turning Point ◽  
Case Scenario ◽  
State Collapse ◽  
Worst Case ◽  
South Africans ◽  
Nelson Mandela ◽  
Wide Range ◽  
Electricity Provision

South Africa is at a crossroads. The state has not adequately addressed dire human development needs, often failing to provide the services it constitutionally guarantees. As a result, citizens are expressing their frustrations in a variety of ways, at times including violence. These serious challenges are most readily apparent in poverty, inequality and unemployment statistics, but also in electricity provision, billing and affordability as well as a recent spate of racially motivated attacks which highlight the tension both among South Africans and between South Africans and darker skinned foreigners. The country has, however, been on the brink before and avoided the worst-case scenario of full-scale civil war and state collapse. Far too often South Africa's past successes have been attributed to the role of one man, Nelson Mandela. While Mandela was indeed an extraordinary human being who rightly deserved the international awards and accolades as well as the deep admiration of so many, South Africa's triumphs as a society and a state are the product of both cooperative and conflicting contributions by a wide range of actors. A central question at the present juncture is how well equipped domestic actors and institutions are to address the crisis. The following pages seek to provide some insights and through the perspectives of three authors to consider causes and possible responses.

scholarly journals Stochastic Flips on Dimer Tilings

2010 ◽  
Vol DMTCS Proceedings vol. AM,... (Proceedings) ◽  
Author(s):  
Thomas Fernique ◽  
Damien Regnault
Keyword(s):  
Fixed Point ◽  
Markov Process ◽  
Upper Bound ◽  
Numerical Experiments ◽  
Triangular Grid ◽  
Expected Number ◽  
Worst Case ◽  
Average Case ◽  
International Audience

International audience This paper introduces a Markov process inspired by the problem of quasicrystal growth. It acts over dimer tilings of the triangular grid by randomly performing local transformations, called $\textit{flips}$, which do not increase the number of identical adjacent tiles (this number can be thought as the tiling energy). Fixed-points of such a process play the role of quasicrystals. We are here interested in the worst-case expected number of flips to converge towards a fixed-point. Numerical experiments suggest a $\Theta (n^2)$ bound, where $n$ is the number of tiles of the tiling. We prove a $O(n^{2.5})$ upper bound and discuss the gap between this bound and the previous one. We also briefly discuss the average-case.

scholarly journals “FATHERING JAPAN” :DISKURSUS ALTERNATIF DALAM HEGEMONI KETIDAKSETARAAN GENDER DI JEPANG

2018 ◽  
Vol 9 (1) ◽  
pp. 62
Author(s):  
Yusy Widarahesty
Keyword(s):  
Gender Gap ◽  
Gender Stereotypes ◽  
Birth Rate ◽  
Active Role ◽  
Child Rearing ◽  
Non Profit ◽  
Alternative Approach ◽  
The Social ◽  
Security Problem

The phenomenon of gender gap in Japan has brought many impacts of change in Japan from the declining birth rate and including the emergence of non-profit organizations (NPO) action groups namely "Fathering Japan"(Ikumen) founded by Tatsuya Ando in 2006, which tried to present as a form of resistance ideology from the myth of "Gender Stereotypes" hegemony in Japan.Ando established the NPOto encourage present and future fathers to play a more active role in child-rearing.“The priority of traditional Japanese fathers is work ... they don't know what to do even when they come home early," said Tetsuya Ando. Thus, it is important to study this social and cultural phenomenon to understand the whole structure of Japanese non-traditional security problem that can be seen through the “Fathering Japan” as a new discourse. By using the discourse alternative approach to analyze the role of the social movement of "Fathering Japan" (Ikumen) as the resistance ideology from Japan cultural mythology, the study was conducted by using qualitative methods through the Discourse Analysis by Ernesto and Chantal Mouffe.Keywords: Fathering Japan, discourse, Non Profit Organization, gender gap, JapanAbstrakFenomena kesenjangan gender di Jepang telah membawa banyak dampak perubahan di Jepang dari tingkat kelahiran yang menurun dan termasuk munculnya  Organisasi Non Profit  (NPO) yaitu "Fathering Japan" (Ikumen) yang didirikan oleh Tatsuya Ando pada 2006, yang mencoba menyajikan bentuk ideologi perlawanan dari mitos hegemoni "Gender Stereotypes" di Jepang. Ando mendirikan NPO untuk mendorong ayah hadir di masa depan untuk memainkan peran yang lebih aktif dalam membesarkan anak. "Prioritas ayah tradisional Jepang adalah pekerjaan ... mereka tidak tahu apa yang harus dilakukan bahkan ketika mereka pulang lebih awal," kata Tetsuya Ando.Dengan demikian, penting untuk mempelajari fenomena sosial dan budaya ini untuk memahami keseluruhan struktur masalah keamanan non-tradisional Jepang yang dapat dilihat melalui "Fathering Japan" sebagai diskursus baru. Dengan menggunakan pendekatan diskursus alternatif  untuk menganalisis peran gerakan sosial "Fathering Japan" (Ikumen) sebagai ideologi perlawanan dari mitologi budaya Jepang, penelitian ini dilakukan dengan menggunakan metode kualitatif melalui Analisis Wacana oleh Ernesto dan Chantal Mouffe .Kata kunci: fathering Jepang, diskursus, NPO, ketimpangan gender, Jepang

From Myth to History: Historicizing a Sage for the Sake of Persuasion in the Yellow Emperor Narratives

2017 ◽  
Vol 3 (1) ◽  
pp. 91-116 ◽  
Author(s):  
Hanmo Zhang
Keyword(s):  
Historical Figure ◽  
Alternative Approach ◽  
Chinese Scholars ◽  
Chinese Texts ◽  
The Many ◽  
Remote Past

Among the many depictions of the Yellow Emperor that survive in a number of early Chinese texts, the historicized image of this purported ancient sage king has been accepted by many Chinese scholars as that of a historical figure and has greatly inspired their reconstruction of China’s remote past. In examining some of the extant Huangdi narratives, especially passages preserved in theDiscourses of the States[Guoyu],Records of the Grand Historian[Shiji], andRemaining Zhou Documents[Yi Zhoushu], this paper reveals a trend of historicizing an originally mythical Yellow Emperor presented in early Chinese writings. It also explores the historiographical reasoning behind such historicization and provides an alternative approach emphasizing the role of persuasion in the Huangdi narratives.

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