9 research outputs found
Fremont-Smith: The Foundations and Government: State and Federal Law and Supervision
Digimergo Àr en digitalisering av Emergo Train System, ett system dÀr personal inom rÀddningstjÀnst kan öva pÄ olika katastrofscenarion. För att göra Digimergo anvÀndbart behövdes ytterligare programvara: ett administrationsverktyg till övningar och en scenarioeditor. I det programvaruutvecklingsprojekt som denna rapport behandlar har ny programvara utvecklats och integrerats med det ursprungliga Digimergosystemet. I den hÀr rapporten diskuteras vilka risker som existerar nÀr ny funktionalitet skall lÀggas till ett gammalt projekt samt hur dessa risker kan minimeras. Rapporten undersöker ocksÄ vilka utvecklingsmetoder som lÀmpar sig i projekt dÀr ny funktionalitet ska lÀggas till befintliga system. Resultatet visar att den största risken med att utöka befintliga projekt Àr att underskatta tiden som krÀvs för att sÀtta sig in i projektet i frÄga. Det mest effektiva sÀttet att minimera risken för detta Àr att mycket tidigt studera det tidigare arbetet och utbilda projektmedlemmarna i det gamla systemet. Ett annat angreppssÀtt Àr att vÀlja en metod som Àr flexibel nÀr det kommer till nya risker eller Àndringar i projektets plan, förslagsvis iterativa metoder
Dividing the Indivisible : Algorithms, Empirical Advances, and Complexity Results for Value-Maximizing Combinatorial Assignment Problems
Allocating resources, goods, agents (e.g., humans), expertise, production, and assets is one of the most influential and enduring cornerstone challenges at the intersection of artificial intelligence, operations research, politics, and economics. At its coreâas highlighted by a number of seminal works [181, 164, 125, 32, 128, 159, 109, 209, 129, 131]âis a timeless question: How can we best allocate indivisible entitiesâsuch as objects, items, commodities, jobs, or personnelâso that the outcome is as valuable as possible, be it in terms of expected utility, fairness, or overall societal welfare? This thesis confronts this inquiry from multiple algorithmic viewpoints, focusing on the value-maximizing combinatorial assignment problem: the optimization challenge of partitioning a set of indivisibles among alternatives to maximize a given notion of value. To exemplify, consider a scenario where an international aid organization is responsible for distributing medical resources, such as ventilators and vaccines, and allocating medical personnel, including doctors and nurses, to hospitals during a global health crisis. These resources and personnelâinherently indivisible and non-fragmentableânecessitate an allocation process designed to optimize utility and fairness. Rather than using manual interventions and ad-hoc methods, which often lack precision and scalability, a rigorously developed and demonstrably performant approach can often be more desirable. With this type of challenge in mind, our thesis begins through the lens of computational complexity theory, commencing with an initial insight: In general, under prevailing complexity-theoretic assumptions (P â NP), it is impossible to develop an eïŹicient method guaranteeing a value-maximizing allocation that is better than âarbitrarily badâ, even under severely constraining limitations and simplifications. This inapproximability result not only underscores the problemâs complexity but also sets the stage for our ensuing work, wherein we develop novel algorithms and concise representations for utilitarian, egalitarian, and Nash welfare maximization problems, aimed at maximizing average, equitable, and balanced utility, respectively. For example, we introduce the synergy hypergraphâa hypergraph-based characterization of utilitarian combinatorial assignmentâwhich allows us to prove several new state-of-the-art complexity results to help us better understand how hard the problem is. We then provide eïŹicient approximation algorithms and (non-trivial) exponential-time algorithms for many hard cases. In addition, we explore complexity bounds for generalizations with interdependent effects between allocations, known as externalities in economics. Natural applications in team formation, resource allocation, and combinatorial auctions are also discussed; and a novel âbootstrappedâ dynamic-programming method is introduced. We then transition from theory to practice as we shift our focus to the utilitarian variant of the problemâan incarnation of the problem particularly applicable to many real-world scenarios. For this variation, we achieve substantial empirical algorithmic improvements over existing methods, including industry-grade solvers. This work culminates in the development of a new hybrid algorithm that combines dynamic programming with branch-and-bound techniques that is demonstrably faster than all competing methods in finding both optimal and near-optimal allocations across a wide range of experiments. For example, it solves one of our most challenging problem sets in just 0.25% of the time required by the previous best methods, representing an improvement of approximately 2.6 orders of magnitude in processing speed. Additionally, we successfully integrate and commercialize our algorithm into Europa Universalis IVâone of the worldâs most popular strategy games, with a player base exceeding millions. In this dynamic and challenging setting, our algorithm eïŹiciently manages complex strategic agent interactions, highlighting its potential to improve computational eïŹiciency and decision-making in real-time, multi-agent scenarios. This also represents one of the first instances where a combinatorial assignment algorithm has been applied in a commercial context. We then introduce and evaluate several highly eïŹicient heuristic algorithms. These algorithmsâwhile lacking provable quality guaranteesâemploy general-purpose heuristic and random-sampling techniques to significantly outperform existing methods in both speed and quality in large-input scenarios. For instance, in one of our most challenging problem sets, involving a thousand indivisibles, our best algorithm generates outcomes that are 99.5% of the expected optimal in just seconds. This performance is particularly noteworthy when compared to state-of-the-art industry-grade solvers, which struggle to produce any outcomes under similar conditions. Further advancing our work, we employ novel machine learning techniques to generate new heuristics that outperform the best hand-crafted ones. This approach not only showcases the potential of machine learning in combinatorial optimization but also sets a new standard for combinatorial assignment heuristics to be used in real-world scenarios demanding rapid, high-quality decisions, such as in logistics, real-time tactics, and finance. In summary, this thesis bridges many gaps between the theoretical and practical aspects of combinatorial assignment problems such as those found in coalition formation, combinatorial auctions, welfare-maximizing resource allocation, and assignment problems. It deepens the understanding of the computational complexities involved and provides effective and improved solutions for longstanding real-world challenges across various sectorsâproviding new algorithms applicable in fields ranging from artificial intelligence to logistics, finance, and digital entertainment, while simultaneously paving the way for future work in computational problem-solving and optimization. Funding: MIRAI; the Wallenberg AI, Autonomous Systems and Software Program; and the Knut and Alice Wallenberg Foundation.</p
Hybrid Dynamic Programming for Simultaneous Coalition Structure Generation and Assignment
We present, analyze and benchmark two algorithms for simultaneous coalition structure generation and assignment: one based entirely on dynamic programming, and one anytime hybrid approach that uses branch-and-bound together with dynamic programming. To evaluate the algorithmsâ performance, we benchmark them against both CPLEX (an industry-grade solver) and the state-of-the-art using difficult randomized data sets of varying distribution and complexity. Our results show that our hybrid algorithm greatly outperforms CPLEX, pure dynamic programming and the current state-of-the-art in all of our benchmarks. For example, when solving one of the most difficult problem sets, our hybrid approach finds optimum in roughly 0.1% of the time that the current best method needs, and it generates 98% efficient interim solutions in milliseconds in all of our anytime benchmarks; a considerable improvement over what previous methods can achieve
Simultaneous coalition formation and task assignment in a real-time strategy game
In this thesis we present an algorithm that is designed to improve the collaborative capabilities of agents that operate in real-time multi-agent systems. Furthermore, we study the coalition formation and task assignment problems in the context of real-time strategy games. More specifically, we design and present a novel anytime algorithm for multi-agent cooperation that efficiently solves the simultaneous coalition formation and assignment problem, in which disjoint coalitions are formed and assigned to independent tasks simultaneously. This problem, that we denote the problem of collaboration formation, is a combinatorial optimization problem that has many real-world applications, including assigning disjoint groups of workers to regions or tasks, and forming cross-functional teams aimed at solving specific problems. The algorithm's performance is evaluated using randomized artificial problems sets of varying complexity and distribution, and also using Europa Universalis 4 â a commercial strategy game in which agents need to cooperate in order to effectively achieve their goals. The agents in such games are expected to decide on actions in real-time, and it is a difficult task to coordinate them. Our algorithm, however, solves the coordination problem in a structured manner. The results from the artificial problem sets demonstrates that our algorithm efficiently solves the problem of collaboration formation, and does so by automatically discarding suboptimal parts of the search space. For instance, in the easiest artificial problem sets with 12 agents and 8 tasks, our algorithm managed to find optimal solutions after only evaluating approximately 0.000003% of the possible solutions. In the hardest of the problem sets with 12 agents and 8 tasks, our algorithm managed to find a 80% efficient solution after only evaluating approximately 0.000006% of the possible solutions.I denna uppsats presenteras en ny algoritm som Ă€r designad för att förbĂ€ttra samarbetsförmĂ„gan hos agenter som verkar i realtidssystem. Vi studerar Ă€ven koalitionsbildnings- och uppgiftstilldelningsproblemen inom realtidsstrategispel, och löser dessa problem optimalt genom att utveckla en effektiv anytime-algoritm som löser det kombinerade koalitionsbildnings- och uppgiftstilldelningsproblemet, inom vilket disjunkta koalitioner formas och tilldelas uppgifter. Detta problem, som vi kallar samarbetsproblemet, Ă€r en typ av optimeringsproblem som har mĂ„nga viktiga motsvarigheter i verkligheten, exempelvis för skapandet av arbetsgrupper som skall lösa specifika problem, eller för att ta fram optimala tvĂ€rfunktionella team med tilldelade uppgifter. Den presenterade algoritmens prestanda utvĂ€rderas dels genom att anvĂ€nda simulerade problem av olika svĂ„righetsgrad, men ocksĂ„ genom att anvĂ€nda verkliga problembeskrivningar frĂ„n det kommersiella strategispelet Europa Universalis 4, vilket Ă€r ett spel som agenter mĂ„ste samarbeta i för att effektivt uppnĂ„ deras mĂ„l. Att koordinera agenter i sĂ„dana spel Ă€r svĂ„rt, men vĂ„r algoritm Ă„stadkommer detta genom att systematiskt söka efter de optimala agentgrupperingarna för ett antal givna uppgifter. Resultaten frĂ„n de simulerade problemen visar att vĂ„r algoritm effektivt löser samarbetsproblemet genom att systematiskt sĂ„lla bort suboptimala delar av sökrymden. I dessa tester lyckas vĂ„r algoritm generera högkvalitativa anytime-lösningar. Till exempel, i de enklaste problemen med 12 agenter och 8 uppgifter lyckas vĂ„r algoritm hitta den optimala lösningen efter det att den endast utvĂ€rderat 0.000003% av de möjliga lösningarna. I de svĂ„raste problemen med 12 agenter och 8 uppgifter lyckas vĂ„r algoritm hitta en lösning som Ă€r 80% frĂ„n den optimala lösningen efter det att den endast utvĂ€rderat 0.000006% av de möjliga samarbetsstrukturerna
An anytime algorithm for optimal simultaneous coalition structure generation and assignment
An important research problem in artificial intelligence is how to organize multiple agents, and coordinate them, so that they can work together to solve problems. Coordinating agents in a multi-agent system can significantly affect the systems performance-the agents can, in many instances, be organized so that they can solve tasks more efficiently, and consequently benefit collectively and individually. Central to this endeavor is coalition formation-the process by which heterogeneous agents organize and form disjoint groups (coalitions). Coalition formation often involves finding a coalition structure (an exhaustive set of disjoint coalitions) that maximizes the systems potential performance (e.g., social welfare) through coalition structure generation. However, coalition structure generation typically has no notion of goals. In cooperative settings, where coordination of multiple coalitions is important, this may generate suboptimal teams for achieving and accomplishing the tasks and goals at hand. With this in mind, we consider simultaneously generating coalitions of agents and assigning the coalitions to independent alternatives (e.g., tasks/goals), and present an anytime algorithm for the simultaneous coalition structure generation and assignment problem. This combinatorial optimization problem hasmany real-world applications, including forming goal-oriented teams. To evaluate the presented algorithms performance, we present five methods for synthetic problem set generation, and benchmark the algorithm against the industry-grade solver CPLEXusing randomized data sets of varying distribution and complexity. To test its anytime-performance, we compare the quality of its interim solutions against those generated by a greedy algorithm and pure random search. Finally, we also apply the algorithm to solve the problem of assigning agents to regions in a major commercial strategy game, and show that it can be used in game-playing to coordinate smaller sets of agents in real-time.Funding Agencies|Linkoping University; Wallenberg AI, Autonomous Systems and Software Program (WASP) - Knut and Alice Wallenberg Foundation</p
Anytime Heuristic and Monte Carlo Methods for Large-Scale Simultaneous Coalition Structure Generation and Assignment
Optimal simultaneous coalition structure generation and assignment is computationally hard. The state-of-the-art can only compute solutions to problems with severely limited input sizes, and no effective approximation algorithms that are guaranteed to yield high-quality solutions are expected to exist. Real-world optimization problems, however, are often characterized by large-scale inputs and the need for generating feasible solutions of high quality in limited time. In light of this, and to make it possible to generate better feasible solutions for difficult large-scale problems efficiently, we present and benchmark several different anytime algorithms that use general-purpose heuristics and Monte Carlo techniques to guide search. We evaluate our methods using synthetic problem sets of varying distribution and complexity. Our results show that the presented algorithms are superior to previous methods at quickly generating near-optimal solutions for small-scale problems, and greatly superior for efficiently finding high-quality solutions for large-scale problems. For example, for problems with a thousand agents and values generated with a uniform distribution, our best approach generates solutions 99.5% of the expected optimal within seconds. For these problems, the state-of-the-art solvers fail to find any feasible solutions at all
Improving Usability of Search and Rescue Decision Support Systems : WARA-PS Case Study
Novel autonomous search and rescue systems, although powerful, still require a human decision-maker involvement. In this project, we focus on the human aspect of one such novel autonomous SAR system. Relying on the knowledge gained in a field study, as well as through the literature, we introduced several extensions to the system that allowed us to achieve a more user-centered interface. In the evaluation session with a rescue service specialist, we received positive feedback and defined potential directions for future work
En undersökning i riskhantering för vidareutveckling av redan existerande projekt
Digimergo Àr en digitalisering av Emergo Train System, ett system dÀr personal inom rÀddningstjÀnst kan öva pÄ olika katastrofscenarion. För att göra Digimergo anvÀndbart behövdes ytterligare programvara: ett administrationsverktyg till övningar och en scenarioeditor. I det programvaruutvecklingsprojekt som denna rapport behandlar har ny programvara utvecklats och integrerats med det ursprungliga Digimergosystemet. I den hÀr rapporten diskuteras vilka risker som existerar nÀr ny funktionalitet skall lÀggas till ett gammalt projekt samt hur dessa risker kan minimeras. Rapporten undersöker ocksÄ vilka utvecklingsmetoder som lÀmpar sig i projekt dÀr ny funktionalitet ska lÀggas till befintliga system. Resultatet visar att den största risken med att utöka befintliga projekt Àr att underskatta tiden som krÀvs för att sÀtta sig in i projektet i frÄga. Det mest effektiva sÀttet att minimera risken för detta Àr att mycket tidigt studera det tidigare arbetet och utbilda projektmedlemmarna i det gamla systemet. Ett annat angreppssÀtt Àr att vÀlja en metod som Àr flexibel nÀr det kommer till nya risker eller Àndringar i projektets plan, förslagsvis iterativa metoder