A stable light source obtained using sum-frequency generation (SFG) is developed for high-resolution spectroscopy at 578 nm. Hyperfine transitions of molecular iodine are observed by using the SFG light source with saturation spectroscopy. The light source is frequency stabilized to the observed hyperfine transition and achieves a stability of 2x10(-12) for a 1-s averaging time. The absolute fr...

A systematic approach for the design of Switched Current (SI) ladder filters is described. The specifications of the filter in z-domain are used to obtain continued fraction expansions (CFE). Signal Flow Graphs (SFG) of each row of the expansion is derived and then these SFG are directly transformed into switched current structures (integrators and amplifiers). The SI blocks thus obtained are c...

We estimated the seroprevalence and determined the frequency of acute infections with Neorickettsia sennetsu, spotted fever group rickettsiae, Rickettsia typhi, and Orientia tsutsugamushi among 2,225 febrile patients presenting to community hospitals in three rural Thailand provinces during 2002-2005. The seroprevalence was 0.2% for sennetsu neorickettsiosis (SN), 0.8% for spotted fever group (...

We present an implemented unification-based parser for relational grammars developed within the s t ra t i f ied f ea tu re g r a m m a r (SFG) framework, which generalizes Kasper-Rounds logic to handle relational grammar analyses. We first introduce the key aspects of SFG and a lexicalized, graph-based variant of the framework suitable for implementing relational grammars. We then describe a h...

This paper presents a heuristic technique for automatically generating different architectures for an analog system. The architecture generator (AG) starts from a signal-flow graph (SFG) specification of a system. The AG iteratively produces various system net-lists as distinct implementations can realize the signal processing and flow in an SFG. Area and power for resulting net-lists are rapid...

In Brazil, the spotted fever group (SFG) Rickettsia rickettsii and Rickettsia parkeri related species are the etiological agents of spotted fever rickettsiosis. However, the SFG, Rickettsia rhipicephali, that infects humans, has never been reported. The study of growth dynamics can be useful for understanding the infective and invasive capacity of these pathogens. Here, the growth rates of the ...

The relaxation dynamics of a rubbed polystyrene (PS) surface have been characterized using infrared-visible sum frequency generation spectroscopy (SFG). The SFG results were compared with previous relaxation of retardation measurements, and the results show that the rubbed PS surface has the same T(g) as the bulk where T(g) is defined as tau(T(g))=5 s, however, the surface has a lower activatio...

Spontaneous parametric down conversion (PDC), in the perturbative limit, can be considered as a probabilistic splitting of one input photon into two output photons. Conversely, sum-frequency generation (SFG) implements reverse process combining photons one. Here we show that single-photon projective measurement temporal-mode basis two-photon SFG effects generalized on state. We describe positiv...