Technology
Inter Genre Similarity Modelling For Automatic Music Genre Classification
Music genre classification is an essential tool for music information retrieval systems and it has been finding critical applications in various media platforms. Two important problems of the automatic music genre classification are feature extraction and classifier design. This paper investigates inter-genre similarity modelling (IGS) to improve the performance of automatic music genre classification. Inter-genre similarity information is extracted over the mis-classified feature population. Once the inter-genre similarity is modelled, elimination of the inter-genre similarity reduces the inter-genre confusion and improves the identification rates. Inter-genre similarity modelling is further improved with iterative IGS modelling(IIGS) and score modelling for IGS elimination(SMIGS). Experimental results with promising classification improvements are provided.
Efficient Markov Network Structure Discovery Using Independence Tests
Bromberg, F., Margaritis, D., Honavar, V.
We present two algorithms for learning the structure of a Markov network from data: GSMN* and GSIMN. Both algorithms use statistical independence tests to infer the structure by successively constraining the set of structures consistent with the results of these tests. Until very recently, algorithms for structure learning were based on maximum likelihood estimation, which has been proved to be NP-hard for Markov networks due to the difficulty of estimating the parameters of the network, needed for the computation of the data likelihood. The independence-based approach does not require the computation of the likelihood, and thus both GSMN* and GSIMN can compute the structure efficiently (as shown in our experiments). GSMN* is an adaptation of the Grow-Shrink algorithm of Margaritis and Thrun for learning the structure of Bayesian networks. GSIMN extends GSMN* by additionally exploiting Pearl's well-known properties of the conditional independence relation to infer novel independences from known ones, thus avoiding the performance of statistical tests to estimate them. To accomplish this efficiently GSIMN uses the Triangle theorem, also introduced in this work, which is a simplified version of the set of Markov axioms. Experimental comparisons on artificial and real-world data sets show GSIMN can yield significant savings with respect to GSMN*, while generating a Markov network with comparable or in some cases improved quality. We also compare GSIMN to a forward-chaining implementation, called GSIMN-FCH, that produces all possible conditional independences resulting from repeatedly applying Pearl's theorems on the known conditional independence tests. The results of this comparison show that GSIMN, by the sole use of the Triangle theorem, is nearly optimal in terms of the set of independences tests that it infers.
Graph Theory and Optimization Problems for Very Large Networks
Graph theory provides a primary tool for analyzing and designing computer communication networks. In the past few decades, Graph theory has been used to study various types of networks, including the Internet, wide Area Networks, Local Area Networks, and networking protocols such as border Gateway Protocol, Open shortest Path Protocol, and Networking Networks. In this paper, we present some key graph theory concepts used to represent different types of networks. Then we describe how networks are modeled to investigate problems related to network protocols. Finally, we present some of the tools used to generate graph for representing practical networks.
Improvements for multi-objective flow shop scheduling by Pareto Iterated Local Search
The article describes the proposition and application of a local search metaheuristic for multi-objective optimization problems. It is based on two main principles of heuristic search, intensification through variable neighborhoods, and diversification through perturbations and successive iterations in favorable regions of the search space. The concept is successfully tested on permutation flow shop scheduling problems under multiple objectives and compared to other local search approaches. While the obtained results are encouraging in terms of their quality, another positive attribute of the approach is its simplicity as it does require the setting of only very few parameters.
The Single Machine Total Weighted Tardiness Problem - Is it (for Metaheuristics) a Solved Problem ?
The article presents a study of rather simple local search heuristics for the single machine total weighted tardiness problem (SMTWTP), namely hillclimbing and Variable Neighborhood Search. In particular, we revisit these approaches for the SMTWTP as there appears to be a lack of appropriate/challenging benchmark instances in this case. The obtained results are impressive indeed. Only few instances remain unsolved, and even those are approximated within 1% of the optimal/best known solutions. Our experiments support the claim that metaheuristics for the SMTWTP are very likely to lead to good results, and that, before refining search strategies, more work must be done with regard to the proposition of benchmark data. Some recommendations for the construction of such data sets are derived from our investigations.
A Tool for Gas Turbine Maintenance Scheduling
Bohlin, Markus (Swedish Institute of Computer Science) | Doganay, Kivanc (Swedish Institute of Computer Science) | Kreuger, Per (Swedish Institute of Computer Science) | Steinert, Rebecca (Swedish Institute of Computer Science) | Wärja, Mathias (Siemens Industrial Turbomachinery AB)
We describe the implementation and deployment of a software decision support tool for themaintenance planning of gas turbines. The tool is used to plan the maintenance for turbines manufactured and maintained by Siemens Industrial Turbomachinery AB (SIT AB) with the goal to reduce the direct maintenance costs and the often very costly production losses during maintenance downtime. The optimization problem is formally defined, and we argue that feasibility in it is NP-complete. We outline a heuristic algorithm that can quickly solve the problem for practical purposes, and validate the approach on a real-world scenario based on an oil production facility. We also compare the performance of our algorithm with results from using mixed integer linear programming, and discuss the deployment of the application. The experimental results indicate that downtime reductions up to 65% can be achieved, compared to traditional preventive maintenance. In addition, using our tool is expected to improve availability with up to 1% and reduce the number of planned maintenance days with 12%. Compared to a mixed integer programming approach, our algorithm not optimal, but is orders of magnitude faster and produces results which are useful in practice. Our test results and SIT AB's estimates based on operational use both indicate that significant savings can be achieved by using our software tool, compared to maintenance plans with fixed intervals.
Managing Helpful Behavior in Collaborative Activities of Heterogeneous Agent Groups
Kamar, Ece (Harvard University)
This thesis aims to provide a foundation for designing computer agents able to work better with people and with other agents in heterogeneous groups. When agents work together on a collaborative activity, in addition to performing their share of the activity, they may be able to help one another and thus improve the collective utility. The thesis specifically focuses on investigating the question of how, when and what kinds of helpful behavior should emerge when agents collaborate, taking into account the costs of a helpful action. It considers collaborative activities that take place in settings in which there is uncertainty about agents' capabilities and about the state of the world. To ensure that helpful behavior improves the overall benefit of the collaboration, the thesis incorporates decision-theoretic mechanisms for managing helpful behavior into existing formalizations of collaborative activity. It provides an investigation of the way people perceive the usefulness of helpful actions when proposed by a computer agent. It proposes incentives for facilitating collaboration among self-interested agents. In addition to these theoretical and empirical contributions, my findings are applied to several real-life application domains with different characteristics.
Game-Mechanics Reasoning for Automated Design Support
Nelson, Mark J. (Georgia Institute of Technology)
Videogame design fundamentally involves engineering interactive rule systems: a game designer combines a set of game mechanics such that, when they interact with each other and with the player’s actions, they produce the desired gameplay. Game designers typically prototype these rule systems to understand how they operate. Prototypes range from paper versions, in which a stripped-down form of the game’s rule system is simulated manually, to playable, implemented versions, which can be played by the designer and others to get feedback on gameplay ideas or discover problems. This thesis proposes that a number of the design questions such prototypes try to answer can be answered automatically. The ultimate design questions are mainly subjective: is the game interesting, fun, challenging, balanced, etc.? However, much prototyping gets at these issues indirectly by asking objective questions that help the designer understand how their rule system operates; the objective kinds of questions are amenable to automated reasoning, since they have answers that depend solely on the game’s formal rule system. By answering them automatically, we can speed up the design loop by allowing designers to quickly understand how their rule system is operating, getting much more factual understanding of the system that they can use in their subjective design thinking.