Engineering Dynamic Complexity in Reacting Systems

约翰·L·哈德森00730597智力优势：国际和平研究所计划为在由许多相互作用的元素组成的化学和生物系统中出现的复杂的集体动态行为开发系统化的方法。与专注于系统的单个组件的方法不同，基于模型的方法描述了仅通过部件的知识无法理解的紧急集体属性。建立了简化但精确的降阶模型，但仍能捕捉系统行为的重要特征；这些简化的模型应直接从实验中推导出来，并且不需要反应动力学的机理细节。他将研究在基于实验的模型的帮助下构建的非线性反馈在设计复杂的动态结构和调整由许多元素组成的系统中的广泛紧急集体行为方面的使用。由于反馈设计方法依赖于描述具有弱相互作用的一般自组织节奏模式的阶段模型描述，所提出的方法能够在弱耦合系统中创建大类结构。这项研究的一个重要方面是，我们能够在电化学振荡器群体的独立实验中测试反馈方法的适用范围，在这些实验中，局部动力学和产生的波形以及耦合强度和拓扑结构都是系统变化的。将应用于相互夹带和动态区分，用于产生顺序访问的动态簇图案，以及用于破坏相互作用振荡器群体的不希望的同步的非线性反起搏器的设计。他将解决一个具有理论和实践重要性的问题：如何在不破坏固有的局部行为的情况下，利用微弱的、非破坏性的信号将动力系统带到理想的状态。广泛的影响：这项研究解决了由具有商业重要性的实际应用所驱动的基本问题。对基于实验的模型的研究将为模拟、预测和控制一大类需要定量描述但难以获得动力学信息的化学和生物系统的动态行为开辟了一条途径。因此，它可以在从化学反应到腐蚀的反应系统中得到应用，在这些反应系统中，反应位置之间的相互作用是行为的主要特征。正在开发的一般方法应该是当代系统工程和系统生物学问题中的一个有价值的工具，即在描述大量元素之间的相互作用的层次结构方面，哪种类型的建模和实验工具是最佳的，这些元素在数学上是容易处理的，但又捕捉到了系统的基本属性。它可能有助于揭示亚细胞、细胞、组织和系统水平的机制如何共同导致生理动态活动的同步、生成和表达。模型设计的反馈可用于医用起搏器和反起搏器的设计(震颤、癫痫)，以及用于通信的高功率激光和微波振荡器等应用。PI研究的一个重要重点是培训学生和扩大代表不足群体的参与。目前，我们的团队中有两名女研究生和两名女本科生；在过去的十年里，有三名非裔美国研究生完成了他们的博士学业。他将与德国、中国、墨西哥、日本和立陶宛的国际合作伙伴开展合作学习和积极交流研究生。他计划继续参与在美国和海外展示他的工作，其中包括为第三世界国家的学生和研究人员组织的研讨会。

John L. Hudson 00730597Intellectual Merit: The PI plans to develop systematic methodologies for engineering complex collective dynamic behavior that arises in chemical and biological systems composed of many interacting elements. Unlike approaches that focus on individual components of a system, the model-based approach describes emergent collective properties that cannot be understood only from a knowledge of the parts. Simplified yet accurate models of reduced order that nevertheless capture important features of system behavior are developed; these reduced models shall be derived directly from experiments and formulated without the need for mechanistic details on reaction kinetics. He will investigate the use of nonlinear feedback constructed with the help of experiment-based models in designing complex dynamic structure and tuning a wide spectrum of emergent collective behavior in systems composed of many elements. Since the feedback design methodology relies on a phase model description that describes general self-organized rhythmic patterns with weak interactions, the proposed methodology is capable of creating a large class of structures in weakly coupled systems. An important aspect of the proposed study is our ability to test the limits of applicability of the feedback methodology in independent experiments on populations of electrochemical oscillators in which the local dynamics and resulting waveform as well as the coupling strength and topology are systematically varied. Application will be made to mutual entrainment and dynamical differentiation, to the generation of sequentially visited dynamic cluster patterns, and to the design of nonlinear anti-pacemakers for the destruction of undesired synchronization of populations of interacting oscillators. He will address a question of both theoretical and practical importance: how to bring dynamical systems to a desired condition with weak, non-destructive signals without destroying the inherent local behavior.Broader Impacts: The research addresses fundamental issues that are driven by practical applications of commercial importance. The study on experiment-based models will open a route to modeling, predicting, and controlling dynamic behavior in a large class of chemical and biological systems in which a quantitative description is required but where kinetic information is difficult to obtain. As such it could find application in reacting systems from chemical reactors to corrosion where interactions among reaction sites are dominant features of behavior. The general methodology being developed should be a valuable tool in a contemporary problem of systems engineering and systems biology, viz., what types of modeling and experimental tools are optimal in describing a hierarchy of interactions among large numbers of elements that are both mathematically tractable but yet which capture the essential properties of the system. It may help reveal how sub-cellular, cellular, tissue and system-level mechanisms collectively lead to synchronization, generation, and expression of physiological dynamical activities. The model-engineered feedback may find use in pacemaker and anti-pacemaker design for medical use (tremors, epilepsy) as well as for applications such as high-power lasers and microwave oscillators for communications.A strong emphasis of the PI's studies is on the training of students and broadening the participation of underrepresented groups. Presently two female graduate students and two female undergraduate students are in our group; in the past ten years three African-American graduate students have completed their PhD studies. He will carry out collaborative studies and an active exchange of graduate students with international partners in Germany, China, Mexico, Japan, and Lithuania. He plans to continue his participation in presentation of his work in the USA and overseas; this includes workshops organized for students and investigators from third world countries.