@article{bortner_meshkat_2022, title={Identifiable Paths and Cycles in Linear Compartmental Models}, volume={84}, ISSN={["1522-9602"]}, DOI={10.1007/s11538-022-01007-5}, abstractNote={We introduce a class of linear compartmental models called identifiable path/cycle models which have the property that all of the monomial functions of parameters associated to the directed cycles and paths from input compartments to output compartments are identifiable and give sufficient conditions to obtain an identifiable path/cycle model. Removing leaks, we then show how one can obtain a locally identifiable model from an identifiable path/cycle model. These identifiable path/cycle models yield the only identifiable models with certain conditions on their graph structure and thus we provide necessary and sufficient conditions for identifiable models with certain graph properties. A sufficient condition based on the graph structure of the model is also provided so that one can test if a model is an identifiable path/cycle model by examining the graph itself. We also provide some necessary conditions for identifiability based on graph structure. Our proofs use algebraic and combinatorial techniques.}, number={5}, journal={BULLETIN OF MATHEMATICAL BIOLOGY}, author={Bortner, Cashous and Meshkat, Nicolette}, year={2022}, month={May} }
 @article{bortner_sullivant_2022, title={Structural identifiability of series-parallel LCR systems}, volume={112}, ISSN={["1095-855X"]}, DOI={10.1016/j.jsc.2022.01.002}, abstractNote={We consider the identifiability problem for the parameters of series-parallel LCR circuit networks. We prove that for networks with only two classes of components (inductor-capacitor (LC), inductor-resistor (LR), and capacitor-resistor (RC)), the parameters are identifiable if and only if the number of non-monic coefficients of the constitutive equations equals the number of parameters. The notion of the “type” of the constitutive equations plays a key role in the identifiability of LC, LR, and RC networks. We also investigate the general series-parallel LCR circuits (with all three classes of components), and classify the types of constitutive equations that can arise, showing that there are 22 different types. However, we produce an example that shows that the basic notion of type that works to classify identifiability of two class networks is not sufficient to classify the identifiability of general series-parallel LCR circuits.}, journal={JOURNAL OF SYMBOLIC COMPUTATION}, author={Bortner, Cashous and Sullivant, Seth}, year={2022}, pages={79–104} }