The turbulent Prandtl number has been calculated in the two-loop approximation of the epsilon expansion of the stochastic theory of turbulence. The strikingly small value obtained for the two-loop correction explains the good agreement of the earlier one-loop result with the experiment. This situation is drastically different from other available nontrivial two-loop results, which exhibit corre...

We review the structure D = 6, N = 1 string vacua with emphasis on the different connections due to T -dualities and S-dualities. The topics discussed include: Anomaly cancellation; K3 and orbifold D = 6, N = 1 heterotic compactifications; T -dualities between E8 × E8 and Spin(32)/Z2 heterotic vacua; non-perturbative heterotic vacua and small instantons; N = 2 TypeII/Heterotic duality in D = 4 ...

Adaptive adjustments of strategies help optimize behavior in a dynamic and uncertain world. Previous studies in the countermanding (or stop-signal) paradigm have detailed how reaction times (RTs) change with trial sequence, demonstrating adaptive control of movement generation. Comparatively little is known about the adaptive control of movement cancellation in the countermanding task, mainly b...

In the field of acoustic echo cancellation, it is well known that the amount of cancellation that can be obtained in real-world systems is limited. Euphemistically this has been referred to in the acoustic echo cancellation community as ”the 20 dB rule” [?]. This rule was formed from many real-world observations that one can typically obtain only about 20-30 dB of cancellation. The acoustic ech...

Extracranial patterns of scalp potentials and magnetic fields, as measured with electro- and magnetoencephalography (EEG, MEG), are spatially widespread even when the underlying source in the brain is focal. Therefore, loss in signal magnitude due to cancellation is expected when multiple brain regions are simultaneously active. We characterized these cancellation effects in EEG and MEG using a...

We propose the notion of a quasiminimal abstract elementary class (AEC). This is an AEC satisfying four semantic conditions: countable Löwenheim-Skolem-Tarski number, existence of a prime model, closure under intersections, and uniqueness of the generic orbital type over every countable model. We exhibit a correspondence between Zilber’s quasiminimal pregeometry classes and quasiminimal AECs: a...

In the field of acoustic echo cancellation, it is well known that the amount of cancellation attainable in real-world systems is limited. Euphemistically this limitation has been referred to in the acoustic echo cancellation community as the “20 dB rule” [1]. This rule reflects the observation that, typically, one can obtain only about 20 to 30 dB of acoustic echo cancellation in actual physica...

We study the constraints on five–dimensional N = 1 heterotic M–theory imposed by a consistent anomaly–free coupling of bulk and boundary theory. This requires analyzing the cancellation of triangle gauge anomalies on the four–dimensional orbifold planes due to anomaly inflow from the bulk. We find that the semi–simple part of the orbifold gauge groups and certain U(1) symmetries have to be free...

We connect two seemingly unrelated problems in graph theory. Any graph G has a neighborhood multiset N (G) = {N(x) | x ∈ V (G)} whose elements are precisely the open vertex-neighborhoods of G. In general there exist non-isomorphic graphs G and H for which N (G) = N (H). The neighborhood reconstruction problem asks the conditions under which G is uniquely reconstructible from its neighborhood mu...

one of the limitations of orthogonal frequency division multiplexing (ofdm) in many applications is its sensitivity to frequency shifts, errors normally referred to as carrier frequency offset (cfo). although, this small offset is negligible in conventional single carrier communication systems, it is a severe problem in the ofdm systems. because, the carriers in ofdm are inherently closely spac...