scholarly journals Publicly Verifiable Outsourcing Computation for QR Decomposition Based on Blockchain

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Huimin Wang ◽  
Dong Zheng ◽  
Qinglan Zhao
Keyword(s):  
Large Scale ◽  
Qr Decomposition ◽  
Limited Resources ◽  
The Public ◽  
Security Challenges ◽  
The Matrix ◽  
Cdh Assumption ◽  
Computation Scheme ◽  
Scale Matrix ◽  
Public Verification

In the Big Data Era, outsourcing computation has become increasingly significant as it supplies computation resources for clients with limited resources. However, there are still many security challenges such as payment fairness, privacy protection, and verification. In this paper, we propose a secure publicly verifiable outsourcing computation scheme for the large-scale matrix QR decomposition. In the proposed scheme, client can pay for outsourcing services through blockchain-based payment system which achieves the payment fairness. Moreover, to protect privacy, both permutation matrix and block diagonal matrix are applied in encryption process. Meanwhile, to achieve the public verification, the computational complexity is reduced by using the matrix digest technology. It is worth mentioning that our scheme is provable and secure under the co-CDH assumption.

scholarly journals On Randomized Trace Estimates for Indefinite Matrices with an Application to Determinants

2021 ◽  
Author(s):  
Alice Cortinovis ◽  
Daniel Kressner
Keyword(s):  
Large Scale ◽  
Gaussian Process Regression ◽  
Likelihood Estimation ◽  
Random Vectors ◽  
Symmetric Positive Definite ◽  
Matrix Logarithm ◽  
The Matrix ◽  
Trace Estimation ◽  
Scale Matrix ◽  
Existing Result

AbstractRandomized trace estimation is a popular and well-studied technique that approximates the trace of a large-scale matrix B by computing the average of $$x^T Bx$$ x T B x for many samples of a random vector X. Often, B is symmetric positive definite (SPD) but a number of applications give rise to indefinite B. Most notably, this is the case for log-determinant estimation, a task that features prominently in statistical learning, for instance in maximum likelihood estimation for Gaussian process regression. The analysis of randomized trace estimates, including tail bounds, has mostly focused on the SPD case. In this work, we derive new tail bounds for randomized trace estimates applied to indefinite B with Rademacher or Gaussian random vectors. These bounds significantly improve existing results for indefinite B, reducing the number of required samples by a factor n or even more, where n is the size of B. Even for an SPD matrix, our work improves an existing result by Roosta-Khorasani and Ascher (Found Comput Math, 15(5):1187–1212, 2015) for Rademacher vectors. This work also analyzes the combination of randomized trace estimates with the Lanczos method for approximating the trace of f(B). Particular attention is paid to the matrix logarithm, which is needed for log-determinant estimation. We improve and extend an existing result, to not only cover Rademacher but also Gaussian random vectors.

scholarly journals Split-and-Combine Singular Value Decomposition for Large-Scale Matrix

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Jengnan Tzeng
Keyword(s):  
Singular Value Decomposition ◽  
Large Scale ◽  
Semantic Analysis ◽  
Computational Cost ◽  
Matrix Decomposition ◽  
Singular Value ◽  
Fast Method ◽  
The Matrix ◽  
Scale Matrix ◽  
Value Decomposition

The singular value decomposition (SVD) is a fundamental matrix decomposition in linear algebra. It is widely applied in many modern techniques, for example, high- dimensional data visualization, dimension reduction, data mining, latent semantic analysis, and so forth. Although the SVD plays an essential role in these fields, its apparent weakness is the order three computational cost. This order three computational cost makes many modern applications infeasible, especially when the scale of the data is huge and growing. Therefore, it is imperative to develop a fast SVD method in modern era. If the rank of matrix is much smaller than the matrix size, there are already some fast SVD approaches. In this paper, we focus on this case but with the additional condition that the data is considerably huge to be stored as a matrix form. We will demonstrate that this fast SVD result is sufficiently accurate, and most importantly it can be derived immediately. Using this fast method, many infeasible modern techniques based on the SVD will become viable.

scholarly journals Bibliometric Study

2020 ◽  
Vol 8 (2) ◽  
pp. 230-240
Author(s):  
Drielle da Guia Cintra Ribeiro ◽  
Artur Virgílio Simpson Martins ◽  
Kaio Alexandre da Silva ◽  
Ricardo Alves Oliveira ◽  
Jorge Washington de Amorim Junior ◽  
...  
Keyword(s):  
Balanced Scorecard ◽  
Public Management ◽  
Large Scale ◽  
Management Practices ◽  
Scientific Production ◽  
Web Database ◽  
The Balanced Scorecard ◽  
The Public ◽  
The Matrix ◽  
Quantitative Nature

With the evolution of management practices, new management methods and tools were adopted in public entities in order to optimize the delivery of services to their steakholders. In this scenario, the Balanced Scorecard (BSC) offers an important tool to assist in the strategic management of public entities. Therefore, this work aims to generate a bibliometric analysis of the scientific production on the BSC tool in the public sector in the period of five years (2014-2018), to clarify the functionalities and to survey data through the Web Database of Science. The procedure to perform this review of scientific production involved, initially, access to the database, followed by research by the terms "BSC and Government" and "BSC and Public Management". Afterwards, they were exported and ordered in the matrix in order to perform the analysis of the elements obtained. The methodology used was of a descriptive and quantitative nature. The main results emphasize that the production registered in the database used is scarce, observing that only 27 publications were found in the studied temporal cutout. It also indicates that, in the range comprised, the Brazilian production was on a large scale together with the Australian and Portuguese production equated to other countries contained in the research and, finally, that there is an inconstancy in the publication of articles related to this subject. This article is structured as follows: introduction, theoretical reference, methodology, results and discussions and conclusion.

3D DDA Based on Variational Inequality Theory and Its Solution Scheme

2018 ◽  
Vol 15 (08) ◽  
pp. 1850081 ◽  
Author(s):  
W. Jiang ◽  
H. Zheng ◽  
G. H. Sun ◽  
W. Chen ◽  
P. C. Song
Keyword(s):  
Large Scale ◽  
Discontinuous Deformation Analysis ◽  
Deformation Analysis ◽  
Numerical Instability ◽  
Contact Conditions ◽  
Inequality Theory ◽  
Discontinuous Deformation ◽  
Computation Scheme ◽  
New Formulation ◽  
Scale Matrix

The advantage of 3D discontinuous deformation analysis (3D DDA) is the rigorous contact conditions on the interaction of 3D blocks. These conditions are enforced by the penalty function convention; however, inappropriate penalty parameters easily generate numerical instability. To avoid the introduction of the penalty parameters, the contact conditions in 3D DDA are described as variational inequalities in this study, and the extra-gradient method is employed to solve this new formulation of 3D DDA. The proposed computation scheme is more flexible and dispenses with large scale matrix inversion. Some practical examples originally designed by Shi are analysed, verifying the effectiveness and precision of the new scheme.

scholarly journals Citizen Assessments of Government Actions in the COVID-19 Outbreak in China

2020 ◽  
Vol 11 (2) ◽  
pp. 110
Author(s):  
Hao Zha ◽  
Youlang Zhang ◽  
Jing Zhao ◽  
Xufeng Zhu
Keyword(s):  
Public Health ◽  
Large Scale ◽  
Online Survey ◽  
Limited Resources ◽  
Government Information ◽  
The Public ◽  
Public Health Emergencies ◽  
Indirect Exposure ◽  
The Government ◽  
Chinese Public

This study investigates citizen assessments of government actions in the COVID-19 outbreak in China.Empirical analyses based on a large-scale online survey indicate that the Chinese public expects the government to improve its support for the frontline medical staff, management of public stress and anxiety, and disclosure of government information. Specifically, indirect exposure to COVID-19 through second-hand information is negatively associated with citizen assessments of government actions; by contrast, the first-hand frontline experience with the epidemic is positively associated with citizen assessments of government actions. Findings suggest that citizens with first-hand experience might be more able to judge government actions under the actual constraints of resources and opportunities and are less likely to overemphasize the costs or risks associated with government actions than others without frontline experience. Our work suggests that governments should effectively communicate vivid information regarding government actions to the public during public health emergencies, as more informed citizens might be more supportive of governments with limited resources and, probably, more actively collaborate with governments.

Is economic inequality a universal evil?

2019 ◽  
pp. 91-106 ◽  
Author(s):  
Rostislav I. Kapeliushnikov
Keyword(s):  
Quantitative Data ◽  
Large Scale ◽  
Economic Inequality ◽  
The State ◽  
Fair Play ◽  
Left Wing ◽  
Ordinary People ◽  
The Public ◽  
Discursive Power ◽  
A Current

Using published estimates of inequality for two countries (Russia and USA) the paper demonstrates that inequality measuring still remains in the state of “statistical cacophony”. Under this condition, it seems at least untimely to pass categorical normative judgments and offer radical political advice for governments. Moreover, the mere practice to draw normative conclusions from quantitative data is ethically invalid since ordinary people (non-intellectuals) tend to evaluate wealth and incomes as admissible or inadmissible not on the basis of their size but basing on whether they were obtained under observance or violations of the rules of “fair play”. The paper concludes that a current large-scale ideological campaign of “struggle against inequality” has been unleashed by left-wing intellectuals in order to strengthen even more their discursive power over the public.

KETERTINDASAN MELAYU DALAM CERPEN “SUKU POMPONG” KARYA FEDLI AZIS DAN CERPEN “RUMAH DI UJUNG KAMPUNG” KARYA HANG KAFRAWI

2017 ◽  
Vol 6 (1) ◽  
pp. 1
Author(s):  
Marlina Marlina
Keyword(s):  
Short Stories ◽  
Large Scale ◽  
Social Aspects ◽  
Land Conversion ◽  
The Public ◽  
Historical Reality ◽  
Sociological Approach ◽  
The Social ◽  
Imaginative Literature ◽  
The Village

Reading short stories “Suku Pompong” (Pompong Tribe) and “Rumah di Ujung Kampung” (House at the End of the Village) is like reading a historical reality that is happening on the ground of Riau Malay. The exploitation of forest resources on a large scale in recent decades in Riau Province has changed the land use of the area of intact forest into plantation area. The exploitation process causes friction in the community. The friction is eventually lead to conflict between communities and plantation companies. Their struggle to resolve conflicts and maintain their ancestral land, the strength of the company that has the license to the land and sadness when the public finally has always been on the losing side. This study objected to describe the objective reality of the Malay community in terms of land conversion, the communal land into plantations and reality of imaginative literature contained in the short stories “Suku Pompong” dan “Rumah di Ujung Kampung”. This study applied the sociology of literature approach, while the sociological approach to literature is a literary approach that specializes in reviewing literature by considering the social aspects. Based on these approaches, it can be concluded that short stories Suku Pompong and Rumah di Ujung Jalan are short stories that raised the reality of the Malay community.AbstrakMembaca cerpen “Suku Pompong” dan cerpen “Rumah di Ujung Kampung” seperti membaca sebuah realita sejarah yang terjadi di tanah Melayu Riau. Ekploitasi sumber daya hutan secara besar-besaran pada beberapa dekade terakhir di Provinsi Riau telah mengubah tata guna lahan dari kawasan hutan yang utuh menjadi kawasan perkebunan. Proses eksploitasi tersebut menimbulkan gesekan-gesekan dalam masyarakat. Gesekan-gesekan inilah yang akhirnya menimbulkan konflik antara masyarakat dengan pihak perusahaan perkebunan. Perjuangan masyarakat dalam menyelesaikan konflik dan mempertahankan tanah leluhur mereka, kekuatan pihak perusahaan yang memiliki surat izin atas tanah tersebut, dan kesedihan ketika masyarakat akhirnya selalu berada di pihak yang kalah. Penelitian ini bertujuan untuk mendeskripsikan realitas objektif masyarakat Melayu Riau dalam hal alih fungsi lahan, dari lahan tanah ulayat menjadi lahan perkebunan, dan realititas imajinatif sastra yang terdapat dalam cerpen “Suku Pompong” dan cerpen “Rumah di Ujung Kampung”. Penelitian ini menggunakan pendekatan sosiologi sastra, yaitu suatu pendekatan sastra yang mengkhususkan diri dalam menelaah karya sastra dengan mempertimbangkan segi-segi sosial kemasyarakatan. Dari pendekatan tersebut dapat diambil kesimpulan bahwa cerpen “Suku Pompong” dan cerpen “Rumah di Ujung Kampung” memang merupakan cerpen yang mengangkat realitas masyarakat Melayu Riau.

Approaches to Supporting Local and Community Development

2018 ◽  
Author(s):  
Liesel Mack Filgueiras ◽  
Andreia Rabetim ◽  
Isabel Aché Pillar
Keyword(s):  
Large Scale ◽  
Mining Company ◽  
The Sustainable Development ◽  
Social Partnership ◽  
The Public ◽  
Mining Investment ◽  
The Social ◽  
Corporate Social

Reflection about the role of community engagement and corporate social investment in Brazil, associated with the presence of a large economic enterprise, is the major stimulus of this chapter. It seeks to present how cross-sector governance can contribute to the social development of a city and how this process can be led by a partnership comprising a corporate foundation, government, and civil society. The concept of the public–private social partnership (PPSP) is explored: a strategy for building a series of inter-sectoral alliances aimed at promoting the sustainable development of territories where the company has large-scale enterprises, through joint efforts towards integrated long-term strategic planning, around a common agenda. To this end, the case of Canaã dos Carajás is introduced, a municipality in the State of Pará, in the Amazon region, where large-scale mining investment is being carried out by the mining company Vale SA.

Early Debates

2018 ◽  
Author(s):  
Samuel Llano
Keyword(s):  
Eighteenth Century ◽  
Public Space ◽  
Domestic Space ◽  
Limited Resources ◽  
Public And Private ◽  
Conduct Manuals ◽  
The Public ◽  
Clear Cut ◽  
The Social ◽  
Undeserving Poor

This chapter provides an account of how organilleros elicited public anger because their activity did not fit into any of the social aid categories that had been in place since the late eighteenth century. Social aid in Spain relied on a clear-cut distinction between deserving and undeserving poor in order to rationalize the distribution of limited resources and reduce mendicancy on the streets. Organilleros could not, strictly speaking, be considered idle, since they played music, but their activity required no specific skills and was regarded with suspicion as a surrogate form of begging. The in-betweenness of the organillero caused further anger as it challenged attempts to establish a neat distinction between public and private spaces. On one hand, organillo music penetrated the domestic space, which conduct manuals of the nineteenth century configured as female; on the other, it brought women into the public space, which those manuals configured as male.

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