742,039 research outputs found
Design concepts for the development of cooperative problem-solving systems
There are many problem-solving tasks that are too complex to fully automate given the current state of technology. Nevertheless, significant improvements in overall system performance could result from the introduction of well-designed computer aids. We have been studying the development of cognitive tools for one such problem-solving task, enroute flight path planning for commercial airlines. Our goal was two-fold. First, we were developing specific systems designs to help with this important practical problem. Second, we are using this context to explore general design concepts to guide in the development of cooperative problem-solving systems. These designs concepts are described
The Impact of Task- and Team-Generic Teamwork Skills Training on Team Effectiveness
This study examined the effects of training team members in three task- and teamgeneric teamwork skills: planning and task coordination, collaborative problem solving, and communication. We first examined the degree to which task- and team-generic teamwork skills training impacted team performance on a task unrelated to the content of the training program.We then examined whether the effects of task- and team-generic teamwork skills training on team performance were due to the transfer of skills directly related to planning and task coordination, collaborative problem solving, and communication. Results from 65 four-person project teams indicated that task- and team-generic teamwork skills training led to significantly higher levels of team performance. Results also indicated that the effects of task- and teamgeneric teamwork skills training on team performance were mediated by planning and task coordination and collaborative problem solving behavior. Although communication was positively affected by the task- and team-generic teamwork skills training, it did not mediate the relationship between task- and team-generic teamwork skills training and team performance.Theoretical and practical implications of these results are discussed, as well as possible limitations and directions for future research
On Using Unsatisfiability for Solving Maximum Satisfiability
Maximum Satisfiability (MaxSAT) is a well-known optimization pro- blem, with
several practical applications. The most widely known MAXS AT algorithms are
ineffective at solving hard problems instances from practical application
domains. Recent work proposed using efficient Boolean Satisfiability (SAT)
solvers for solving the MaxSAT problem, based on identifying and eliminating
unsatisfiable subformulas. However, these algorithms do not scale in practice.
This paper analyzes existing MaxSAT algorithms based on unsatisfiable
subformula identification. Moreover, the paper proposes a number of key
optimizations to these MaxSAT algorithms and a new alternative algorithm. The
proposed optimizations and the new algorithm provide significant performance
improvements on MaxSAT instances from practical applications. Moreover, the
efficiency of the new generation of unsatisfiability-based MaxSAT solvers
becomes effectively indexed to the ability of modern SAT solvers to proving
unsatisfiability and identifying unsatisfiable subformulas
Group Capabilities and Process Quality in Complex Problem Solving
During my (lean) consultancy assignments I experienced that many organisations and groups struggle with achieving improvement results, not having an effective process of problem solving. In my PhD research, I therefore explored the quality of groups’ problem-solving processes. In this research I used mixed-methods, with an important role for video observation of real life problem-solving teams. To study the problem-solving process I used the fine-grained six phase method of structured problem solving. This structured approach is often used in continous improvment strategies like Lean and Kaizen. To better understand the group problem-solving mechanism, theory from the Organizational Behaviour domain namely goal-setting, commitment-to-change, and sensemaking was used. My three empirical studies resulted in 1) a method to code, visualize and measure the group members’ problem-solving process and its quality, 2) process factors related to achieving measurable operational performance improvements, and 3) the impact of individual problem-solving preferences on the quality of the problem-solving process. With this research I contribute to theory more insights and a better understanding of the phase-based process of group problem solving. As for the practical relevance, the results of this research hold direct relevance for problem-solving groups and their facilitators, enhancing their ability to achieve operational performance improvements
Experimental Realization of a One-way Quantum Computer Algorithm Solving Simon's Problem
We report an experimental demonstration of a one-way implementation of a
quantum algorithm solving Simon's Problem - a black box period-finding problem
which has an exponential gap between the classical and quantum runtime. Using
an all-optical setup and modifying the bases of single-qubit measurements on a
five-qubit cluster state, key representative functions of the logical two-qubit
version's black box can be queried and solved. To the best of our knowledge,
this work represents the first experimental realization of the quantum
algorithm solving Simon's Problem. The experimental results are in excellent
agreement with the theoretical model, demonstrating the successful performance
of the algorithm. With a view to scaling up to larger numbers of qubits, we
analyze the resource requirements for an n-qubit version. This work helps
highlight how one-way quantum computing provides a practical route to
experimentally investigating the quantum-classical gap in the query complexity
model.Comment: 9 pages, 5 figure
Parameter Selection and Pre-Conditioning for a Graph Form Solver
In a recent paper, Parikh and Boyd describe a method for solving a convex
optimization problem, where each iteration involves evaluating a proximal
operator and projection onto a subspace. In this paper we address the critical
practical issues of how to select the proximal parameter in each iteration, and
how to scale the original problem variables, so as the achieve reliable
practical performance. The resulting method has been implemented as an
open-source software package called POGS (Proximal Graph Solver), that targets
multi-core and GPU-based systems, and has been tested on a wide variety of
practical problems. Numerical results show that POGS can solve very large
problems (with, say, more than a billion coefficients in the data), to modest
accuracy in a few tens of seconds. As just one example, a radiation treatment
planning problem with around 100 million coefficients in the data can be solved
in a few seconds, as compared to around one hour with an interior-point method.Comment: 28 pages, 1 figure, 1 open source implementatio
Improved Linear Precoding over Block Diagonalization in Multi-cell Cooperative Networks
In downlink multiuser multiple-input multiple-output (MIMO) systems, block
diagonalization (BD) is a practical linear precoding scheme which achieves the
same degrees of freedom (DoF) as the optimal linear/nonlinear precoding
schemes. However, its sum-rate performance is rather poor in the practical SNR
regime due to the transmit power boost problem. In this paper, we propose an
improved linear precoding scheme over BD with a so-called
"effective-SNR-enhancement" technique. The transmit covariance matrices are
obtained by firstly solving a power minimization problem subject to the minimum
rate constraint achieved by BD, and then properly scaling the solution to
satisfy the power constraints. It is proved that such approach equivalently
enhances the system SNR, and hence compensates the transmit power boost problem
associated with BD. The power minimization problem is in general non-convex. We
therefore propose an efficient algorithm that solves the problem heuristically.
Simulation results show significant sum rate gains over the optimal BD and the
existing minimum mean square error (MMSE) based precoding schemes.Comment: 21 pages, 4 figure
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