It is well known that the bilinear transform, or first order diagonal Padé approximation to the matrix exponential, preserves quadratic Lyapunov functions between continuous-time and corresponding discrete-time linear time invariant (LTI) systems, regardless of the sampling time. The analagous result also holds for switched linear systems. In this note we show that, for any sampling time, diago...

this paper presents the formulation and solution of the combinatorial multi-mode resource constrained multi-project scheduling problem. the focus of the proposed method is not on finding a single optimal solution, instead on presenting multiple feasible solutions, with cost and duration information to the project manager. the motivation for developing such an approach is due in part to practica...

We address the peak covariance stability of time-varying Kalman filter with possible packet losses in transmitting measurement outputs to the filter via a packet-based network. The packet losses are assumed to be bounded and driven by a finite-state Markov process. It is shown that if the observability index of the discrete-time linear timeinvariant(LTI) system under investigation is one, the K...

The innate immune system plays a critical early role in host defense against viruses, bacteria, and tumor cells. Until recently, natural killer (NK) cells and lymphoid tissue inducer (LTi) cells were the primary members of the innate lymphocyte family: NK cells form the front-line interface between the external environment and the adaptive immune system, while LTi cells are essential for second...

Cumulant (higher-order statistics) based inverse filter criteria maximizing J,,, = / C,l’/IC,I”, where m # r and C, (C,) denotes the mth-order (rth-order) cumulant of the inverse filter output, have been proposed for blind deconvolution and equalization with only non-Gaussian output measurements of an unknown linear time-invariant (LTI) system. This paper shows that the maximum of J,,,, associa...

Adaptation of the motor system to sensorimotor perturbations is a type of learning relevant for tool use and coping with an ever-changing body. Memory for motor adaptation can take the form of savings: an increase in the apparent rate constant of readaptation compared with that of initial adaptation. The assessment of savings is simplified if the sensory errors a subject experiences at the begi...

k x[k]δ[n − k] : convolution of x[n] and δ[n] = · · · + x[−2]δ[n + 2] + x[−1]δ[n + 1] + x[0]δ[n] + x[1]δ[n − 1] + · · · : any sequence can be decomposed as a sum of scaled and shifted impulses. (a) Scale (by x[k]) and shift (from δ[n] to δ[n− k]) imply linearity and time-invariance, respectively. (b) Envision x[n] : {..., x[−1], x[0], x[1], ...} as a signal vector, and δ[n − k] : {..., 0, δ[n −...

The ‘security index’ of a discrete-time LTI system under sensor attacks is introduced as a quantitative measure on the security of an observable system. We derive ideas from error control coding theory to provide sufficient conditions for attack detection and correction.

Phylogeny shows that CD4 T cell memory and lymph nodes coevolved in placental mammals. In ontogeny, retinoic acid orphan receptor (ROR)γ-dependent lymphoid tissue inducer (LTi) cells program the development of mammalian lymph nodes. In this study, we show that although primary CD4 T cell expansion is normal in RORγ-deficient mice, the persistence of memory CD4 T cells is RORγ-dependent. Further...

Wrist injuries and carpal instability may result from various sport-related acitivites. Lunotriquetral instability (LTI) is an infrequently recognized cause of wrist pain in athletes. The diagnosis of LTI through history and physical examination can be confirmed by Magnetic Resonance Arthrogram (MRA). This case report describes a case of clinically suspected LTI confirmed by MRA. Relevant liter...