Vaguery + multiobjective-optimization 23
[1203.4881] Computational Complexity Analysis of Multi-Objective Genetic Programming
6 weeks ago by Vaguery
Some days I just want to take genetic programming away from the computer scientists. Then I realize I ought to just let them keep the useless, ritualized thing they imagine it is.
facepalm
multiobjective-optimization
software-development-is-not-programming
6 weeks ago by Vaguery
[1201.6054] Attainability in Repeated Games with Vector Payoffs
10 weeks ago by Vaguery
"We introduce the concept of attainable sets of payoffs in two-player repeated games with vector payoffs. A set of payoff vectors is called {em attainable} if player 1 can ensure that there is a finite horizon $T$ such that after time $T$ the distance between the set and the cumulative payoff is arbitrarily small, regardless of what strategy player 2 is using. This paper focuses on the case where the attainable set consists of one payoff vector. In this case the vector is called an attainable vector. We study properties of the set of attainable vectors, and characterize when a specific vector is attainable and when every vector is attainable."
game-theory
agent-based
multiobjective-optimization
nudge-targets
10 weeks ago by Vaguery
[1112.6075] A semidefinite programming approach for solving Multiobjective Linear Programming
january 2012 by Vaguery
Several algorithms are available in the literature for finding the entire set of Pareto-optimal solutions in MultiObjective Linear Programming (MOLP). However, it has not been proposed so far an interior point algorithm that finds all Pareto-optimal solutions of MOLP. We present an explicit construction, based on a transformation of any MOLP into a finite sequence of SemiDefinite Programs (SDP), the solutions of which give the entire set of Pareto-optimal extreme points solutions of MOLP. These SDP problems are solved by interior point methods; thus our approach provides a pseudo-polynomial interior point methodology to find the set of Pareto-optimal solutions of MOLP.
linear-programming
algorithms
multiobjective-optimization
nudge-targets
operations-research
january 2012 by Vaguery
[1101.4744] Clustering functional data using wavelets
october 2011 by Vaguery
"We present two methods for detecting patterns and clusters in high dimensional time-dependent functional data. Our methods are based on wavelet-based similarity measures, since wavelets are well suited for identifying highly discriminant local time and scale features. The multiresolution aspect of the wavelet transform provides a time-scale decomposition of the signals allowing to visualize and to cluster the functional data into homogeneous groups. For each input function, through its empirical orthogonal wavelet transform the first method uses the distribution of energy across scales generate a handy number of features that can be sufficient to still make the signals well distinguishable. Our new similarity measure combined with an efficient feature selection technique in the wavelet domain is then used within more or less classical clustering algorithms to effectively differentiate among high dimensional populations. The second method uses dissimilarity measures between the whole time-scale representations and are based on wavelet-coherence tools. The clustering is then performed using a k-centroid algorithm starting from these dissimilarities. Practical performance of these methods that jointly designs both the feature selection in the wavelet domain and the classification distance is demonstrated through simulations as well as daily profiles of the French electricity power demand."
classification
time-series
feature-extraction
machine-learning
multiobjective-optimization
ontology-discovery
wavelets
nudge-targets
october 2011 by Vaguery
More shocking portraits of robot abuse - io9
may 2011 by Vaguery
It's called the DLR Hand Arm System. It has an anthropomorphic design and packs 52 motors, ultra-miniaturized control electronics, a supercapacitor-based power supply, and a web of high-strength tendons. But what makes it stand out compared to conventional systems is its ability to withstand collisions, thanks to ingeniously designed joints and actuators that can absorb and dissipate energy, much like our own arms and hands do.
robustness
engineering-design
multiobjective-optimization
robotics
may 2011 by Vaguery
[1103.0260] A Linear Approximation Algorithm for 2-Dimensional Vector Packing
april 2011 by Vaguery
"We study the 2-dimensional vector packing problem, which is a generalization of the classical bin packing problem where each item has 2 distinct weights and each bin has 2 corresponding capacities. The goal is to group items into minimum number of bins, without violating the bin capacity constraints.…"
optimization
operations-research
toy-problems
multiobjective-optimization
nudge-targets
bin-packing
from delicious
april 2011 by Vaguery
[1007.4031] Networks with the Smallest Average Distance and the Largest Average Clustering
august 2010 by Vaguery
"We describe the structure of the graphs with the smallest average distance and the largest average clustering given their order and size. There is usually a unique graph with the largest average clustering, which at the same time has the smallest possible average distance. In contrast, there are many graphs with the same minimum average distance, ignoring their average clustering. The form of these graphs is shown with analytical arguments. Finally, we measure the sensitivity to rewiring of this architecture with respect to the clustering coefficient, and we devise a method to make these networks more robust with respect to vertex removal."
graph-theory
network-theory
multiobjective-optimization
combinatorics
august 2010 by Vaguery
[1007.5475] Balanced Combinations of Solutions in Multi-Objective Optimization
august 2010 by Vaguery
"For every list of integers x_1, ..., x_m there is some j such that x_1 + ... + x_j - x_{j+1} - ... - x_m \approx 0. So the list can be nearly balanced and for this we only need one alternation between addition and subtraction. But what if the x_i are k-dimensional integer vectors? Using results from topological degree theory we show that balancing is still possible, now with k alternations.
This result is useful in multi-objective optimization, as it allows a polynomial-time computable balance of two alternatives with conflicting costs. The application to two multi-objective optimization problems yields the following results:
- A randomized 1/2-approximation for multi-objective maximum asymmetric traveling salesman, which improves and simplifies the best known approximation for this problem.
- A deterministic 1/2-approximation for multi-objective maximum weighted satisfiability."
multiobjective-optimization
operations-research
nudge
algorithms
This result is useful in multi-objective optimization, as it allows a polynomial-time computable balance of two alternatives with conflicting costs. The application to two multi-objective optimization problems yields the following results:
- A randomized 1/2-approximation for multi-objective maximum asymmetric traveling salesman, which improves and simplifies the best known approximation for this problem.
- A deterministic 1/2-approximation for multi-objective maximum weighted satisfiability."
august 2010 by Vaguery
[1006.1031] Multiobjective decomposition of integer matrices: application to radiotherapy
july 2010 by Vaguery
"… The aim is to find efficient decompositions that simultaneously minimize the irradiation time, the cardinality of the decomposition and the setup-time to configure the multi-leaf collimator at each step of the decomposition. We propose for this NP-hard multiobjective combinatorial problem a heuristic, based on the adaptation of the two-phase Pareto local search. Experiments are carried out on different size instances and the results are reported."
operations-research
multiobjective-optimization
search-algorithms
radiology
nudge-targets
metaheuristics
july 2010 by Vaguery
[1007.4063] The multiobjective multidimensional knapsack problem: a survey and a new approach
july 2010 by Vaguery
"The knapsack problem (KP) and its multidimensional version (MKP) are basic problems in combinatorial optimization. In this paper we consider their multiobjective extension (MOKP and MOMKP), for which the aim is to obtain or to approximate the set of efficient solutions. In a first step, we classify and describe briefly the existing works, that are essentially based on the use of metaheuristics. In a second step, we propose the adaptation of the two-phase Pareto local search (2PPLS) to the resolution of the MOMKP. With this aim, we use a very-large scale neighborhood (VLSN) in the second phase of the method, that is the Pareto local search. We compare our results to state-of-the-art results and we show that we obtain results never reached before by heuristics, for the biobjective instances. Finally we consider the extension to three-objective instances."
metaheuristics
multiobjective-optimization
algorithms
operations-research
nudge-targets
july 2010 by Vaguery
[1006.4270] Two-dimensional ranking of Wikipedia articles
june 2010 by Vaguery
"The Library of Babel, described by Jorge Luis Borges, stores an enormous amount of information. The Library exists {\it ab aeterno}. Wikipedia, a free online encyclopaedia, becomes a modern analogue of such a Library. Information retrieval and ranking of Wikipedia articles become the challenge of modern society. We analyze the properties of two-dimensional ranking of all Wikipedia English articles and show that it gives their reliable classification with rich and nontrivial features. Detailed studies are done for countries, universities, personalities, physicists, chess players, Dow-Jones companies and other categories."
wikipedia
search-engines
multiobjective-optimization
network-theory
network-culture
june 2010 by Vaguery
[1006.3085] Projective geometry and the outer approximation algorithm for multiobjective linear programming
june 2010 by Vaguery
"A key problem in multiobjective linear programming is to find the set of all efficient extreme points in objective space. In this paper we introduce oriented projective geometry as an efficient and effective framework for solving this problem. The key advantage of oriented projective geometry is that we can work with an "optimally simple" but unbounded efficiency-equivalent polyhedron, yet apply to it the familiar theory and algorithms that are traditionally restricted to bounded polytopes. We apply these techniques to Benson's outer approximation algorithm, using oriented projective geometry to remove an exponentially large complexity from the algorithm and thereby remove a significant burden from the running time."
linear-programming
multiobjective-optimization
algorithms
numerical-methods
nudge-targets
june 2010 by Vaguery
[1006.1328] Uncovering the Riffled Independence Structure of Rankings
june 2010 by Vaguery
"… In this paper, we provide a formal introduction to riffled independence and present algorithms for using riffled independence within Fourier-theoretic frameworks which have been explored by a number of recent papers. Additionally, we propose an automated method for discovering sets of items which are riffle independent from a training set of rankings. We show that our clustering-like algorithms can be used to discover meaningful latent coalitions from real preference ranking datasets and to learn the structure of hierarchically decomposable models based on riffled independence."
statistics
ranking
clustering
data-envelopment-analysis
multiobjective-optimization
nudge
numerical-methods
june 2010 by Vaguery
[0812.3141] Choosing a penalty for model selection in heteroscedastic regression
june 2010 by Vaguery
"We consider the problem of choosing between several models in least-squares regression with heteroscedastic data. We prove that any penalization procedure is suboptimal when the penalty is a function of the dimension of the model, at least for some typical heteroscedastic model selection problems. In particular, Mallows' Cp is suboptimal in this framework. On the contrary, optimal model selection is possible with data-driven penalties such as resampling or $V$-fold penalties. Therefore, it is worth estimating the shape of the penalty from data, even at the price of a higher computational cost. Simulation experiments illustrate the existence of a trade-off between statistical accuracy and computational complexity. As a conclusion, we sketch some rules for choosing a penalty in least-squares regression, depending on what is known about possible variations of the noise-level."
statistics
statistical-tests
linear-regression
meta-optimization
nudge-targets
multiobjective-optimization
pragmatism-it-ain't
june 2010 by Vaguery
[0911.5657] 2D multi-objective placement algorithm for free-form components
june 2010 by Vaguery
"This article presents a generic method to solve 2D multi-objective placement problem for free-form components. The proposed method is a relaxed placement technique combined with an hybrid algorithm based on a genetic algorithm and a separation algorithm. The genetic algorithm is used as a global optimizer and is in charge of efficiently exploring the search space. The separation algorithm is used to legalize solutions proposed by the global optimizer, so that placement constraints are satisfied. A test case illustrates the application of the proposed method. Extensions for solving the 3D problem are given at the end of the article."
nudge-targets
multiobjective-optimization
bin-packing
algorithms
optimization
metaheuristics
geometry
june 2010 by Vaguery
Computation of the Hypervolume Indicator
may 2010 by Vaguery
"The performance assessment of algorithms for multiobjective optimization problems is far from being a trivial issue. Recent results indicate that unary performance measures, i.e. performance measures which assign a single value to each non-dominated point set, are inherently limited in their inferential power. Despite these limitations, the hypervolume indicator (also known as Lebesgue measure or S metric) is still considered to possess some reasonable properties, having also been proposed as a guidance criterion for accepting solutions in Multiobjective Evolutionary Algorithms. Therefore, the computational time taken for computing the hypervolume indicator is a crucial factor for the performance of such algorithms.…"
multiobjective-optimization
measurement
progress
indicators
nudge
library
toolkit
scicomp
may 2010 by Vaguery
Ezra Klein - Too big to fail in two dimensions
april 2010 by Vaguery
"Here's why I don't think of "too big" as a myth for resolving a firm. In my mind, the farther you are from the origin in that graph, the harder it is for the government to detect problems and properly deter large firms under resolution authority. (This is why I draw our "safe" resolution as a circle, instead of a square.) Holding for a liquidity risk, the larger the firm, the more vicious the effects of having a shadow banking run on the rest of the financial sector and on the real economy. It is possible that the green circle here will be cast out far, and that size and pressures of campaign donations won't play a major part. But why take the chance?"
multiobjective-optimization
economics
public-policy
financial-crisis
legislation
regulation
april 2010 by Vaguery
[1003.6119] Multivariate records based on dominance
april 2010 by Vaguery
Nonplussed (but satisfying) to see somebody do such a thorough job discussing something I was planning on doing almost 20 years ago…
theory-of-records
extreme-values
probability
multiobjective-optimization
metaheuristics
null-hypotheses
april 2010 by Vaguery
[1002.4330] Defining and Computing Alternative Routes in Road Networks
february 2010 by Vaguery
"Every human likes choices. But today's fast route planning algorithms usually compute just a single route between source and target. There are beginnings to compute alternative routes, but this topic has not been studied thoroughly. Often, the aspect of meaningful alternative routes is neglected from a human point of view. We fill in this gap by suggesting mathematical definitions for such routes. As a second contribution we propose heuristics to compute them, as this is NP-hard in general."
operations-research
planning
decision-support
multiobjective-optimization
opportunity
Nudge
optimization
alternatives
open-questions
february 2010 by Vaguery
[PDF] Application of Large-scale Layout Optimization Techniques in Structural Engineering Practice
february 2010 by Vaguery
"It was also realised that had the layout optimization solver been incorporated within a user-friendly interactive software package, then it would have been very much easier to rapidly change the design problem in response to feedback from other members of the design team..."
engineering-design
optimization
mechanical-engineering
genetic-programming-target
multiobjective-optimization
user-experience
agility
inagility
modeling
february 2010 by Vaguery
A Brief Introduction to Skyline Problem (Pareto-optimal Tuples) (1) | Dive into A Data Deluge
september 2009 by Vaguery
"The skyline problem is to compute the best tuples from a set of ordered d-tuples. The name is originated from what the solution represented on 2d plane resembles the scene that urban buildings comprise. Skyline is one of the recommendation queries, and it is considering multi criteria. It is very interesting problem as well as very useful query. This problem has been being intensively studied for recent years. Today, I’m going to present the problem definition of skyline. Next time, I’ll describe several algorithms for the skyline problem."
skyline
Pareto-front
multiobjective-optimization
database
algorithms
explanation
september 2009 by Vaguery
http://www.cse.unsw.edu.au/~luoyi/paper/Yi/2004.pdf
september 2009 by Vaguery
"In this paper, we will present a novel R-tree based algorithm, which adopts a depth- first search technique. In the algorithm, we also developed a “forward checking” tech- nique based on a “region dominance” relation to reduce space complexity. We can show that the new algorithm is I/O optimal and requires a logarithmic space in the worst case in the 2D space if there are not many overlapping in R-tree. Further, our experiment demonstrated that the new algorithm requires a much smaller space than the existing I/O optimal techniques, and is progressive in a way sensitive to user’s requirements."
databases
programming
algorithms
search
Nudge
multiobjective-optimization
Pareto-front
cunning
september 2009 by Vaguery
The Stalin Compiler « Justin Domke’s Weblog
february 2009 by Vaguery
Stalin is extremely slow to compile. In principle this isn’t a big deal: you can debug using a different scheme compiler. Still, Stalin seems to be somewhat less robust to edge cases, than at least chicken scheme.
It is amazing that Scheme code with no type declarations can beat C by almost a factor of 2.
Though in principle Stalin produces intermediate c code, it is utterly alien and low-level. I have not been able to determine exactly what options Stalin is using when it calls gcc on the source code. That could account for some of the difference.
trade-offs
programming
multiobjective-optimization
compilers
LISP
C
design-automation
middleware
It is amazing that Scheme code with no type declarations can beat C by almost a factor of 2.
Though in principle Stalin produces intermediate c code, it is utterly alien and low-level. I have not been able to determine exactly what options Stalin is using when it calls gcc on the source code. That could account for some of the difference.
february 2009 by Vaguery
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