scholarly journals Greybox Algorithm Configuration

2021 ◽  
Author(s):  
Marie Anastacio
Keyword(s):  
State Of The Art ◽  
Automated Algorithm ◽  
Wide Range ◽  
Algorithm Configuration ◽  
Improve Algorithm ◽  
The Difference ◽  
Problem Instances ◽  
The Right ◽  
Parameter Values ◽  
Configuration Problem

The performance of state-of-the-art algorithms is highly dependent on their parameter values, and choosing the right configuration can make the difference between solving a problem in a few minutes or hours. Automated algorithm configurators have shown their efficiency on a wide range of applications. However, they still encounter limitations when confronted to a large number of parameters to tune or long algorithm running time. We believe that there is untapped knowledge that can be gathered from the elements of the configuration problem, such as the default value in the configuration space, the source code of the algorithm, and the distribution of the problem instances at hand. We aim at utilising this knowledge to improve algorithm configurators.

scholarly journals ParamILS: An Automatic Algorithm Configuration Framework

2009 ◽  
Vol 36 ◽  
pp. 267-306 ◽  
Author(s):  
F. Hutter ◽  
H. H. Hoos ◽  
K. Leyton-Brown ◽  
T. Stuetzle
Keyword(s):  
Mixed Integer ◽  
Considerable Effort ◽  
Performance Improvements ◽  
Automatic Algorithm Configuration ◽  
Automated Algorithm ◽  
Algorithm Configuration ◽  
Consistent Performance ◽  
Problem Instances ◽  
Automatic Algorithm ◽  
Configuration Problem

The identification of performance-optimizing parameter settings is an important part of the development and application of algorithms. We describe an automatic framework for this algorithm configuration problem. More formally, we provide methods for optimizing a target algorithm’s performance on a given class of problem instances by varying a set of ordinal and/or categorical parameters. We review a family of local-search-based algorithm configuration procedures and present novel techniques for accelerating them by adaptively limiting the time spent for evaluating individual configurations. We describe the results of a comprehensive experimental evaluation of our methods, based on the configuration of prominent complete and incomplete algorithms for SAT. We also present what is, to our knowledge, the first published work on automatically configuring the CPLEX mixed integer programming solver. All the algorithms we considered had default parameter settings that were manually identified with considerable effort. Nevertheless, using our automated algorithm configuration procedures, we achieved substantial and consistent performance improvements.

20. Freehold Covenants

2017 ◽  
Author(s):  
Barbara Bogusz ◽  
Roger Sexton
Keyword(s):  
Third Parties ◽  
Restrictive Covenants ◽  
Wide Range ◽  
Explanatory Text ◽  
The Law ◽  
The Difference ◽  
Concept Building ◽  
The Right ◽  
The Impact ◽  
Primary Materials

Titles in the Complete series combine extracts from a wide range of primary materials with clear explanatory text to provide readers with a complete introductory resource. This chapter discusses the difference between restrictive and positive covenants; the rules which govern the running of the burden of covenants; the rules regulating who initially has the right to enforce a covenant; the significance of s56 of the Law of Property Act 1925, and the impact of the Contracts (Rights of Third Parties) Act 1999; the rules regarding assignment of restrictive covenants; the concept ‘building scheme’; and whether a positive or restrictive covenant will pass to successors in title.

Cost–benefit and water resources policy: a survey

Water Policy ◽  
2011 ◽  
Vol 14 (2) ◽  
pp. 250-280 ◽  
Author(s):  
Frank A. Ward
Keyword(s):  
Water Policy ◽  
Cost Benefit Analysis ◽  
Cost Benefit ◽  
Benefit Analysis ◽  
Trade Offs ◽  
Wide Range ◽  
Recent Developments ◽  
The Difference ◽  
Policy Cost ◽  
The Right

This paper reviews recent developments in cost–benefit analysis for water policy researchers who wish to understand the applications of economic principles to inform emerging water policy debates. The cost–benefit framework can provide a comparison of total economic gains and losses resulting from a proposed water policy. Cost–benefit analysis can provide decision-makers with a comparison of the impacts of two or more water policy options using methods that are grounded in time-tested economic principles. Economic efficiency, measured as the difference between added benefits and added costs, can inform water managers and the public of the economic impacts of water programs to address peace, development, health, the environment, climate and poverty. Faced by limited resources, cost–benefit analysis can inform policy choices by summarizing trade-offs involved in designing, applying, or reviewing a wide range of water programs. The data required to conduct a cost–benefit analysis are often poor but the steps needed to carry out that analysis require posing the right questions.

scholarly journals 4.K. Workshop: What is going on? New inequalities emerging from the COVID-19 syndemic

2021 ◽  
Vol 31 (Supplement_3) ◽  
Author(s):  
◽  
Keyword(s):  
Public Health ◽  
Mental Health ◽  
Gender Inequalities ◽  
Cognitive Changes ◽  
Public Health Professionals ◽  
Measurement Framework ◽  
Wide Range ◽  
The Difference ◽  
The Right ◽  
The Impact

Abstract   COVID-19 pandemic interacts with the pandemic of chronic non-communicable diseases and is exacerbated in different social and societal contexts through existing health inequalities - resulting in a syndemic. The socio-economically weakest groups of the population have been most affected (Bambra, 2020, Horton, 2020). In 2020, most activities were focused on controlling the epidemic through a biomedical approach, and only in the second half of the year, with the onset of the second wave, did the understanding that we are dealing with a syndemic, emerge in public health, societal and lately political discourse at the national and EU levels. There is increasing indirect damage to public health due to the loss of jobs and income, the long-term closure of certain activities, difficult access to health systems for those with non-COVID-19 health problems, and general uncertainty about the present and future. Different dimensions of syndemic inequalities (e.g. mental health, cognitive decline, lifestyles, gender, intergenerational) are the main focus of the workshop, including inequalities that were traditionally perceived in public health, as well as new emerging inequalities. In Slovenia we are conducting a study on the impact of the syndemic on people's lives (SI-PANDA 2020/2021), to (1) better understand human behaviour in COVID-19 pandemic and (2) to identify and address the impact of the governmental decisions, pandemic measures and recommendations. The workshop will aim to: Showcase the value of timely measurement and surveying of the COVID-19 syndemic's influences on society; Increase participants' understanding and awareness of the opportunities and challenges associated with different types of inequalities linked to COVID-19; Increase awareness of public health professionals on the importance of overcoming the difference between the biomedical approach and psychosocial paradigms; The workshop will offer an opportunity to: Present some of the outputs of the PANDA research and outline the influences of COVID-19 on lifestyle, mental health and cognitive changes Inform participants about the benefits of the comprehensive national approach in measuring COVID-19 syndemic consequences, embedded in a broader internationally comparative WHO measurement framework; Explore traditional inequalities with new dimensions, such as gender inequalities, newly emerging economic vulnerabilities and transformational inequalities, such as intergenerational inequality. Identify possible syndemic outcome measures at the national and EU levels, while identifying gaps between employing biomedical versus psychosocial approach in controlling conditions. Key messages Present new evidence on a wide range of inequalities emerging from the COVID-19 syndemic and its approach to mitigate it. Showcase an example from Slovenia (within the WHO internationally harmonized approach) of timely measuring the right data to inform a biomedical response as well as psychosocial measures.

Choosing the Right “Bit Pad”: Human Factors Aspects of Digitizing Tablet Size

1982 ◽  
Vol 26 (7) ◽  
pp. 615-615
Author(s):  
James L. Knight
Keyword(s):  
Computer Graphics ◽  
Task Analysis ◽  
Movement Control ◽  
Human Movement ◽  
Optimum Size ◽  
Wide Range ◽  
The Right ◽  
Parameter Values ◽  
Selection Of ◽  
Digitizing Tablet

Entry of non-alphanumeric information into computer graphics systems is frequently accomplished by moving a drawing implement over the surface of a digitizing tablet. These tablets are commercially available in a wide range of sizes. Therefore, an important question from both ergonomic and economic standpoints concerns the optimum size for the digitizing tablet. To answer this question, models of human movement control were applied to the graphic operator's task. An experiment was conducted to obtain appropriate model parameter values and to empirically evaluate the resulting predictions of the generated models. A combination of task analysis and movement control modelling thus allowed selection of an optimum digitizing tablet size for a range of computer-graphics entry tasks. Details and results of this methodology will be presented.

scholarly journals Automated Algorithm Selection: Survey and Perspectives

2019 ◽  
Vol 27 (1) ◽  
pp. 3-45 ◽  
Author(s):  
Pascal Kerschke ◽  
Holger H. Hoos ◽  
Frank Neumann ◽  
Heike Trautmann
Keyword(s):  
State Of The Art ◽  
Combinatorial Problems ◽  
The State ◽  
Problem Instance ◽  
Ai Planning ◽  
Algorithm Selection ◽  
Automated Algorithm ◽  
Continuous Problems ◽  
Algorithm Configuration ◽  
The One

It has long been observed that for practically any computational problem that has been intensely studied, different instances are best solved using different algorithms. This is particularly pronounced for computationally hard problems, where in most cases, no single algorithm defines the state of the art; instead, there is a set of algorithms with complementary strengths. This performance complementarity can be exploited in various ways, one of which is based on the idea of selecting, from a set of given algorithms, for each problem instance to be solved the one expected to perform best. The task of automatically selecting an algorithm from a given set is known as the per-instance algorithm selection problem and has been intensely studied over the past 15 years, leading to major improvements in the state of the art in solving a growing number of discrete combinatorial problems, including propositional satisfiability and AI planning. Per-instance algorithm selection also shows much promise for boosting performance in solving continuous and mixed discrete/continuous optimisation problems. This survey provides an overview of research in automated algorithm selection, ranging from early and seminal works to recent and promising application areas. Different from earlier work, it covers applications to discrete and continuous problems, and discusses algorithm selection in context with conceptually related approaches, such as algorithm configuration, scheduling, or portfolio selection. Since informative and cheaply computable problem instance features provide the basis for effective per-instance algorithm selection systems, we also provide an overview of such features for discrete and continuous problems. Finally, we provide perspectives on future work in the area and discuss a number of open research challenges.

scholarly journals AutoFolio: An Automatically Configured Algorithm Selector

2015 ◽  
Vol 53 ◽  
pp. 745-778 ◽  
Author(s):  
Marius Lindauer ◽  
Holger H. Hoos ◽  
Frank Hutter ◽  
Torsten Schaub
Keyword(s):  
State Of The Art ◽  
Machine Learning Techniques ◽  
Problem Instance ◽  
Algorithm Selection ◽  
The Core ◽  
Automated Algorithm ◽  
Learning Techniques ◽  
Algorithm Configuration ◽  
Optimal Values ◽  
The One

Algorithm selection (AS) techniques -- which involve choosing from a set of algorithms the one expected to solve a given problem instance most efficiently -- have substantially improved the state of the art in solving many prominent AI problems, such as SAT, CSP, ASP, MAXSAT and QBF. Although several AS procedures have been introduced, not too surprisingly, none of them dominates all others across all AS scenarios. Furthermore, these procedures have parameters whose optimal values vary across AS scenarios. This holds specifically for the machine learning techniques that form the core of current AS procedures, and for their hyperparameters. Therefore, to successfully apply AS to new problems, algorithms and benchmark sets, two questions need to be answered: (i) how to select an AS approach and (ii) how to set its parameters effectively. We address both of these problems simultaneously by using automated algorithm configuration. Specifically, we demonstrate that we can automatically configure claspfolio 2, which implements a large variety of different AS approaches and their respective parameters in a single, highly-parameterized algorithm framework. Our approach, dubbed AutoFolio, allows researchers and practitioners across a broad range of applications to exploit the combined power of many different AS methods. We demonstrate AutoFolio can significantly improve the performance of claspfolio 2 on 8 out of the 13 scenarios from the Algorithm Selection Library, leads to new state-of-the-art algorithm selectors for 7 of these scenarios, and matches state-of-the-art performance (statistically) on all other scenarios. Compared to the best single algorithm for each AS scenario, AutoFolio achieves average speedup factors between 1.3 and 15.4.

Chapter 12. Automated Configuration and Selection of SAT Solvers

2021 ◽  
Author(s):  
Holger H. Hoos ◽  
Frank Hutter ◽  
Kevin Leyton-Brown
Keyword(s):  
Research And Development ◽  
State Of The Art ◽  
Sat Solving ◽  
Sat Solvers ◽  
Effective Application ◽  
Automated Algorithm ◽  
Fertile Ground ◽  
Algorithm Configuration ◽  
Algorithmic Approaches ◽  
Selection Of

This chapter provides an introduction to the automated configuration and selection of SAT algorithms and gives an overview of the most prominent approaches. Since the early 2000s, these so-called meta-algorithmic approaches have played a major role in advancing the state of the art in SAT solving, giving rise to new ways of using and evaluating SAT solvers. At the same time, SAT has proven to be particularly fertile ground for research and development in the area of automated configuration and selection, and methods developed there have meanwhile achieved impact far beyond SAT, across a broad range of computationally challenging problems. Conceptually more complex approaches that go beyond “pure” algorithm configuration and selection are also discussed, along with some open challenges related to meta-algorithmic approaches, such as automated algorithm configuration and selection, to the tools based on these approaches, and to their effective application.

20. Freehold Covenants

2019 ◽  
pp. 613-658
Author(s):  
Barbara Bogusz ◽  
Roger Sexton
Keyword(s):  
Third Parties ◽  
Restrictive Covenants ◽  
Wide Range ◽  
Explanatory Text ◽  
The Law ◽  
The Difference ◽  
Concept Building ◽  
The Right ◽  
The Impact ◽  
Primary Materials

Titles in the Complete series combine extracts from a wide range of primary materials with clear explanatory text to provide readers with a complete introductory resource. This chapter discusses the difference between restrictive and positive covenants; the rules which govern the running of the burden of covenants; the rules regulating who initially has the right to enforce a covenant; the significance of s56 of the Law of Property Act 1925, and the impact of the Contracts (Rights of Third Parties) Act 1999; the rules regarding assignment of restrictive covenants; the concept ‘building scheme’; and whether a positive or restrictive covenant will pass to successors in title.

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