Learning and Cooperating Multi-Agent Scheduling Repair Using a Provenance-Centred Approach

The timetabling problem is to find a timetable solution by assigning time and resources to sessions that satisfy a set of constraints. Traditionally, research has focused on optimization towards a final solution but this paper focuses on minimizing disturbance impact due to changing conditions. A Multi-Agent System (MAS) is proposed in which users are represented as autonomous agents negotiating with one another to repair a timetable. From repeated negotiations, agents learn to develop a model of other agent's preferences. The MAS is simulated on a factorial experiment set up and varying the cooperation level, learning model and selection strategy. A provenance-centred approach is adopted to improve the human aspect of timetabling to allow users to derive the steps towards a solution and make changes to influence the solution

Modeling the Human Decision Making Process in Maritime Interdiction Using Conceptual Blending Theory

Simulation Interoperability Standards Organization (SISO) papers and Behavior Representation in Modeling and Simulation (BRIMS)This paper describes a model of the human decision-making process in maritime interdiction tactical operation using conceptual blending theory (CBT) and software blending mechanism. CBT explains how humans think using blending operations on mental spaces. This paper uses CBT to model Boyd’s Observation-Orientation- Decision-Act Loop Theory, a mental process used by military commanders to make decisions. The software blending mechanism is implemented using the Naval Postgraduate School’s first-generation Software Blending library. Military expert’s experiences were captured using a similar strategy implemented in the threat assessment model created by Liebhaber and Feher. Probability Estimates of Event (PEoE) is used to represent the significant of each possible tactic used by potential threats. Several PEoE are used to represent the mental patterns for recognizing a threat situation. Finally, decisions are derived using linear assignment, an optimality approach that considers threat attack probability, goals and interdiction resource effectiveness. The model was tested in a simulated maritime threat environment in order to evaluate its ability to coordinate interdictions by patrol crafts. These test results were reviewed by experienced naval warfare officers who gave feedback on the quality of the software generated decisions

Approaches to Event Prediction in Complex Environments

MOVES Research & Education Systems Seminar: Presentation; Session 9: Machine Learning and Human Behavior Simulation; Moderator: Chris Darken; Approaches to Event Prediction in Complex Environments; speaker: Terence Tan (PhD Candidate)Scope of Presentation: What is Relational Time Series? Previous Approaches, New Learning and Prediction Approaches, Conclusion

T-DepExp: Simulating transitive dependence based coalition formation

In this paper, we introduce T-DepExp system to simulate the transitive dependence based coalition formation (CF). It is a multi-agent based simulation (MABS) tool that aims to enhance cooperation between agents through transitive dependence. Previously, the transitive dependence was introduced by An and his colleagues for expressing the indirect dependence between agents in their cooperation. However, it did not receive much attention. Although it has a few problems need to be addressed, we try to propose our own mechanism to increase the efficiency of the transitive dependence based CF. To simulate MAS dependence relationship, we have included two fundamental dependence relationships in this MABS tool, which are AND-Dependence and OR-Dependence. In addition, the architecture of the T-DepExp system is presented and discussed. It allows possible integration of other features such as budget mechanism and trust model. Subsequently, hypothesis for the experiments and experimental setup are explained. The overall system will be demonstrated for its functionality and the experimental results will also be discussed

The use of Genetic programing in Exploring 3D Design Worlds

Genetic algorithms are used to evolve rule systems for a generative process, in one case a shape grammar,which uses the "Dawkins Biomorph" paradigm of user driven choices to perform artificial selection, in the other a CA/Lindenmeyer system using the Hausdorff dimension of the resultant configuration to drive natural selection. 1) Using Genetic Programming in an interactive 3d shape grammar (AmyTan &P.S..Coates) A report of a generative system combining genetic programming(GP) and 3D shape grammars. The reasoning that backs up the basis for this work depends on the interpretation of design as search In this system, a 3D form is a computer program made up of functions (transformations) & terminals (building blocks). Each program evaluates into a structure. Hence, in this instance a program is synonymous with form. Building blocks of form are platonic solids (box, cylinder....etc.). A Variety of combinations of the simple affine transformations of translation, scaling, rotation together with Boolean operations of union, subtraction and intersection performed on the building blocks generate different configurations of 3D forms. Using to the methodology of genetic programming, an initial population of such programs are randomly generated,subjected to a test for fitness (the eyeball test). Individual programs that have passed the test are selected to be parents for reproducing the next generation of programs via the process of recombination. 2) Using a GA to evolve rule sets to achieve a goal configuration( T.Broughton & P.Coates ) . The aim of these experiments was to build a framework in which a structure’s form could be defined by a set of instructions encoded into its genetic make-up. This was achieved by combining a generative rule system commonly used to model biological growth with a genetic algorithm simulating the evolutionary process of selection to evolve an adaptive rule system capable of replicating any preselected 3-D shape. The generative modelling technique used is a string rewriting Lindenmayer system the genes of the emergent structures are the production rules of the L-system, and the spatial representation of the structures uses the geometry of iso-spatial dense-packed sphere

Primary central nervous system lymphoma presenting as isolated oculomotor nerve palsy

AbstractThe authors report an unusual case of primary central nervous system lymphoma presenting with isolated pupil-involved oculomotor nerve palsy. Magnetic resonance imaging demonstrated leptomeningeal involvement of the midbrain and interpeduncular cistern, a single hypothalamic lesion, and intraventricular involvement. Diffuse large B-cell lymphoma was confirmed by stereotactic intraventricular biopsy. Combination chemotherapy with methotrexate, vincristine, procarbazine and rituximab was instituted with resolution of oculomotor nerve palsy and complete disease remission. An interdisciplinary approach involving neurosurgeons, neuroradiologists, neuropathologists and neurologists is crucial in the management of primary central nervous system lymphoma

Cyanoacrylate Dermal Closure in Spine Surgery: Systematic Review and Pooled Analysis

Study Design: Systematic review. Objectives: Cyanoacrylate glue closure has been utilized for dermal closure in surgical incisions. Its safety and efficacy in spine surgery are not established. The authors perform a systematic review to determine the rate of surgical site infection (SSI), wound dehiscence, and wound erythema with cyanoacrylate dermal closure in spine surgery. Methods: A systematic review adhering to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines was performed utilizing the PubMed/MEDLINE, EMBASE, and Cochrane databases on patients undergoing spine surgery with cyanoacrylate dermal closure. Pooled analysis was performed with stratification of patients according to spinal level and the presence/absence of instrumentation. Risk-of-bias and methodological quality was appraised using 17 prespecified criteria. Results: Five articles (1 retrospective cohort study, 4 cases series) with a total of 1282 patients were included. A total of 967 patients, all diagnosed with degenerative spine disease, were suitable for pooled analysis. In 290 patients who underwent anterior cervical discectomy and fusion, and in 23 patients with posterior cervical decompression (without instrumentation), there was 0% rate of SSI, wound dehiscence, and erythema. In 489 patients who underwent lumbar microdiscectomy, there was 0.41% rate of SSI, 0.20% rate of wound dehiscence, and 0.20% rate of wound erythema. In 165 lumbar laminectomy patients, there was a 1.82% rate of SSI, 0.61% rate of wound dehiscence, and 0% rate of wound erythema. Conclusion: Cyanoacrylate dermal closure for the aforementioned procedures is associated with low rates of wound complications (SSI, dehiscence, and erythema). Further studies should be performed, especially in nondegenerative surgery, instrumented thoracic and lumbar spine surgery

The Safety Profile of Intentional or Iatrogenic Sacrifice of the Artery of Adamkiewciz and Its Vicinity’s Spinal Segmental Arteries: A Systematic Review

Study Design: Systematic review. Objectives: There is paucity of consensus on whether (1) the artery of Adamkiewicz (AoA) and (2) the number of contiguous segmental spinal arteries (SSAs) that can be safely ligated without causing spinal cord ischemia. The objective of this review is to determine the risk of motor neurological deficits from iatrogenic sacrifice of the (1) AoA and (2) its vicinity’s SSAs. Methods: Systematic review of the spine and vascular surgery was carried out in accordance to PRISMA guidelines. Outcomes in terms of risk of postoperative motor neurological deficit with occlusion of the AoA, bilateral contiguous SSAs, or unilateral contiguous SSAs were analyzed. Results: Ten articles, all retrospective case series, were included. Three studies (total N = 50) demonstrated a postoperative neurological deficit risk of 4.0% when the AoA is occluded. When 1 to 6 pairs of SSAs (without knowledge of AoA location) were ligated, the postoperative neurological deficit risk was 0.6%, as compared with 5.4% when more than 6 bilateral pairs of SSAs were ligated (relative risk [RR] = 0.105, 95% CI 0.013-0.841, P =.0337). For unilateral ligation of SSAs of two to nine levels, the risk of postoperative neurological deficit does not exceed 1.3%. Conclusion: The current best evidence indicates that (1) occlusion of the AoA and (2) occlusion of up to 6 pairs of SSAs is associated with a low risk of postoperative neurological deficit. This limited number of low quality studies restrict the ability to draw definitive conclusions. Ligation of AoA and SSAs should only be undertaken when absolutely required to mitigate the small but devastating risk of paralysis