scholarly journals Generalized Majorization-Minimization for Non-Convex Optimization

Author(s):  
Hu Zhang ◽  
Pan Zhou ◽  
Yi Yang ◽  
Jiashi Feng

Majorization-Minimization (MM) algorithms optimize an objective function by iteratively minimizing its majorizing surrogate and offer attractively fast convergence rate for convex problems. However, their convergence behaviors for non-convex problems remain unclear. In this paper, we propose a novel MM surrogate function from strictly upper bounding the objective to bounding the objective in expectation. With this generalized surrogate conception, we develop a new optimization algorithm, termed SPI-MM, that leverages the recent proposed SPIDER for more efficient non-convex optimization. We prove that for finite-sum problems, the SPI-MM algorithm converges to an stationary point within deterministic and lower stochastic gradient complexity. To our best knowledge, this work gives the first non-asymptotic convergence analysis for MM-alike algorithms in general non-convex optimization. Extensive empirical studies on non-convex logistic regression and sparse PCA demonstrate the advantageous efficiency of the proposed algorithm and validate our theoretical results.

Evolution ◽  
1998 ◽  
Vol 52 (6) ◽  
pp. 1564-1571 ◽  
Author(s):  
Fredric J. Janzen ◽  
Hal S. Stern

2020 ◽  
Vol 2 (4) ◽  
pp. 3405-3418
Author(s):  
Alfamet Randa ◽  
Sany Dwita

This study aims to determine the effect of pentagon fraud’s theory in detecting fraudulent financial reporting empirical studies on companies in property and real estate sector in Indonesia listed on the Stock Exchange in 2014-2018. The sampling technique used purposive sampling with the final sample of 18 companies. Data analysis used in this research is logistic regression analysis. The result of this research showed that : Pressure (ROA), Opportunity (BDOUT), Competence (DCHANGE) and Arogance (CEOPIC) have no significant effect on fraudulent financial reporting. While the Rationalization (Change of Auditor) has a significant effect on fraudulent financial reporting.


Author(s):  
Victoria Edwards ◽  
Paulo Rezeck ◽  
Luiz Chaimowicz ◽  
M. Ani Hsieh

The division of labor amongst a heterogeneous swarm of robots increases the range and sophistication of the tasks the swarm can accomplish. To efficiently execute a task the swarm of robots must have some starting organization. Over the past decade segregation of robotic swarms has grown as a field of research drawing inspiration from natural phenomena such as cellular segregation. A variety of different approaches have been undertaken to devise control methods to organize a heterogeneous swarm of robots. In this work, we present a convex optimization approach to segregate a heterogeneous swarm into a set of homogeneous collectives. We present theoretical results that show our approach is guaranteed to achieve complete segregation and validate our strategy in simulation and experiments.


2020 ◽  
Vol 14 (8) ◽  
pp. 1989-2006
Author(s):  
Ron Estrin ◽  
Michael P. Friedlander

Abstract Level-set methods for convex optimization are predicated on the idea that certain problems can be parameterized so that their solutions can be recovered as the limiting process of a root-finding procedure. This idea emerges time and again across a range of algorithms for convex problems. Here we demonstrate that strong duality is a necessary condition for the level-set approach to succeed. In the absence of strong duality, the level-set method identifies $$\epsilon $$ ϵ -infeasible points that do not converge to a feasible point as $$\epsilon $$ ϵ tends to zero. The level-set approach is also used as a proof technique for establishing sufficient conditions for strong duality that are different from Slater’s constraint qualification.


Author(s):  
Christie M. Fuller ◽  
Rick L. Wilson

Neural networks (NN) as classifier systems have shown great promise in many problem domains in empirical studies over the past two decades. Using case classification accuracy as the criteria, neural networks have typically outperformed traditional parametric techniques (e.g., discriminant analysis, logistic regression) as well as other non-parametric approaches (e.g., various inductive learning systems such as ID3, C4.5, CART, etc.).


2016 ◽  
Vol 17 (4) ◽  
pp. 654-674 ◽  
Author(s):  
Diego Matricano

Purpose According to an emerging research trend, which seeks to apply the concept of intellectual capital (IC) to the field of entrepreneurship, the purpose of this paper is to test whether IC can affect the start-up expectations of aspiring entrepreneurs. Design/methodology/approach Binary logistic regression models, based on empirical data derived from the Global Entrepreneurship Monitor website and referring to Italy over the years 2005-2010, are used to test the influence of IC (comprising human, structural and relational capital) on start-up expectations. Findings Binary logistic regression models reveal robust results. Human, structural and relational capitals affect start-up expectations in Italy. Only in 2010 did structural capital fail to do so. Research limitations/implications This study has three main limitations. The first concerns the need for further research to confirm the influence of IC on start-up expectations. The second concerns in-depth, more exhaustive analyses that cannot be carried out due to the use of second- hand data. The third deals with the reference only to Italy, over a limited time-span (2005-2010). Originality/value To the best knowledge of the author, this is one of the first empirical studies that investigate whether IC can affect start-up expectations. Results revealed by the regression models might steer other scholars’ interest toward this research path (linking IC and entrepreneurship) that has not yet been properly considered.


2021 ◽  
pp. 002029402110293
Author(s):  
Wei Zhu ◽  
Haibao Tian

This paper studies the distributed convex optimization problem, where the global utility function is the sum of local cost functions associated to the individual agents. Only using the local information, a novel continuous-time distributed algorithm based on proportional-integral-differential (PID) control strategy is proposed. Under the assumption that the global utility function is strictly convex and local utility functions have locally Lipschitz gradients, the exponential convergence of the proposed algorithm is established with undirected and connected graph among these agents. Finally, numerical simulations are presented to illustrate the effectiveness of theoretical results.


Author(s):  
Yuanyuan Liu ◽  
Fanhua Shang ◽  
Licheng Jiao

Recently, research on variance reduced incremental gradient descent methods (e.g., SAGA) has made exciting progress (e.g., linear convergence for strongly convex (SC) problems). However, existing accelerated methods (e.g., point-SAGA) suffer from drawbacks such as inflexibility. In this paper, we design a novel and simple momentum to accelerate the classical SAGA algorithm, and propose a direct accelerated incremental gradient descent algorithm. In particular, our theoretical result shows that our algorithm attains a best known oracle complexity for strongly convex problems and an improved convergence rate for the case of n>=L/\mu. We also give experimental results justifying our theoretical results and showing the effectiveness of our algorithm.


Author(s):  
Claudio Alexandre Souza ◽  
Jakson Renner Rodrigues Soares ◽  
María Dolores Sánchez-Fernández

El objetivo de este artículo es presentar un estudio sobre las motivaciones que impulsan a un resort a implementar acciones de responsabilidad social empresarial (RSE), teniendo como base las variables del entorno, los stakeholders y las dimensiones de la sostenibilidad. Este trabajo es el resultado de una investigación bibliográfica procedente de la revisión de artículos y bibliografía sobre los resorts y RSE, principalmente en lo que se refiere a sus respectivas motivaciones. Para la sistematización de este estudio se creó y se utilizó la Matriz de Análisis de la Responsabilidad Social Empresarial (MARSE) integrando las variables del entorno utilizadas en esta investigación. Los resultados evidencian motivaciones sistematizadas, pero estas se comportan de manera única debido a la singularidad del producto turístico resorts y a la amplitud de relaciones sociales que los mismos poseen con sus respectivos stakeholders. Tanto la MARSE, creada para este estudio, como las conclusiones obtenidas, sirven como referencia para la realización de futuros estudios empíricos acerca de las motivaciones de la implementación de la RSE en resorts. La MARSE puede ser considerada como una forma original de analizar el área RSE, debido a la posibilidad de sistematización.ABSTRACTThe purpose of the article is to present a theoretical essay about the motivations that drive a resort the achievements actions of corporate social responsibility, based on environment variables, stakeholders and dimensions of sustainability. This theoretical essay is the result of bibliographic research in journals and bibliographies on resorts and corporate social responsibility, especially regarding their respective motivations. To systematize this test was created and used the Corporate Social Responsibility Analysis Matrix (MARSE) integrating the variables analyzed in this study. The theoretical results are taken by reference motivations already systematized, however they behave in a unique way in this study by the tourism product uniqueness resorts and the extent of social relations that they have towards their respective stakeholders. Both MARSE created for this study, as the conclusions serve as a reference for future specific and empirical studies on CSR motivations resorts. The MARSE can be considered as a unique way to carry out analyzes in the CSR area, it enables the systematic.


Author(s):  
Xuan Bui ◽  
Nhung Duong ◽  
Trung Hoang

<p>Non-convex optimization has an important role in machine learning. However, the theoretical understanding of non-convex optimization remained rather limited. Studying efficient algorithms for non-convex optimization has attracted a great deal of attention from many researchers around the world but these problems are usually NP-hard to solve. In this paper, we have proposed a new algorithm namely GS-OPT (General Stochastic OPTimization) which is effective for solving the non-convex problems. Our idea is to combine two stochastic bounds of the objective function where they are made by a commonly discrete probability distribution namely Bernoulli. We consider GS-OPT carefully on both the theoretical and experimental aspects. We also apply GS-OPT for solving the posterior inference problem in the latent Dirichlet allocation. Empirical results show that our approach is often more efficient than previous ones.</p>


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