Spectro-temporal receptive field

The spectro-temporal receptive field or spatio-temporal receptive field (STRF) of a neuron represents which types of stimuli excite or inhibit that neuron."Spectro-temporal" refers most commonly to audition, where the neuron's response depends on frequency versus time, while "spatio-temporal" refers to vision, where the neuron's response depends on spatial location versus time. Thus they are not exactly the same concept, but both referred to as STRF and serving a similar role in the analysis of neural responses.

If linearity is assumed, the neuron can be modelled as having a time-varying firing rate equal to the convolution of the stimulus with the STRF.

Auditory STRFs

The example STRF here is for an auditory neuron from the area CM (caudal medial) of a male zebra finch, when played conspecific birdsong. The colour of this plot shows the effect of sound on this neuron: this neuron tends to be excited by sound from about 2.5 kHz to 7 kHz heard by the animal 12 ms ago, but it is inhibited by sound in the same frequency range from about 18 ms ago.

Combat Vehicle 90

The Stridsfordon 90 (Strf 90) (Eng. Combat Vehicle 90 (CV90)) is a family of Swedish tracked combat vehicles designed by FMV, Hägglunds and Bofors during the mid-1980s and early 1990s. The Swedish version of the main infantry fighting vehicle is fitted with a turret from Bofors that is equipped with a 40 mm autocannon, although export versions use 30 mm and 35 mm autocannons. Developed specifically for the Nordic sub-arctic climate, it has very good mobility in snow and wetlands while carrying and supporting eight (later versions were reduced to six) fully equipped soldiers. Other variants include Forward Observation, Command and Control, Anti-air, Armoured Recovery, Electronic Warfare and so forth. It is still produced and being developed further by BAE Systems Hägglunds AB.

History

During the Cold War, in 1983, the Swedish Army required vehicles with high mobility, air defence and anti-tank capability, high survivability and protection. The project group "Stridsfordon 90" was formed by representatives from the Swedish armed forces (Försvarsmakten), the Defense Materiel Administration (Försvarets Materielverk) and Swedish industry including Hägglunds and Bofors, which in 1985 finalized the design for a "unity-vehicle" which originated from an airforce concept. In 1986, the prototypes for Strf 9040 and Strf 9025 were ordered. Five prototypes were constructed, but before delivery in 1988, the 9025-version was discontinued. These prototypes were tested during extensive trials for three years between 1988 to 1991, during which the prototypes for specialized variants (FOV, C&C and ARV) were ordered. The first deliveries started in 1994, and as of 2002 over 1,000 CV90s have been delivered worldwide.