CINT

Abstract: A circuit for measuring absolute spread in capacitors implemented in planary technology. A charge pump supplying a charge current to an internal capacitor (Cint) is used, the voltage across the internal capacitor (Cint) being coupled through a comparator for comparing the voltage with first and second threshold levels. A bistable multivibrator reverses the direction of the charge current, to charge the internal capacitor (Cint) when the voltage decreases below the second threshold level, and to decharge the internal capacitor (Cint) when the voltage increases above the first threshold level. The charge current is determined by a reference voltage that is provided across an external resistor (Rext), the first and second threshold levels defining a voltage range being proportional to the reference voltage. An output signal of the bistable multivibrator is coupled to frequency measuring means to compare the repetition frequency thereof with a reference frequency.

Abstract: Cint is an interpretation system for the C programming language. Like most interpretation systems, it provides "load and go" type execution as well as enhanced debugging and performance analysis tools. Cint consists of two phases--a translator and an interpreter. The translator compiles the source program into code for a virtual machine. The interpreter then loads and executes this code. While providing services similar to traditional interpreters, Cint differs from them in two important ways. First, the virtual machine languages used by many interpreters are quite large; machines with 100 to 200 operations are common. In contrast, Cint's virtual machine has only 63 operations. Second, to achieve acceptable execution speeds, interpreters are often implemented in the assembly language of the host machine. Cint, however, is written entirely in C and is therefore portable. In fact, it has been transported to four machines without modification. Despite the compact size of the virtual machine language and the high-level language implementation, Cint's execution speed is comparable to that of other interpreters. This paper describes the design of the virtual machine, the implementation of the interpreter, and the performance of the system.

Abstract: The problem of optimal illumination for selective array imaging of small and not well separated scatterers in clutter is considered. The imaging algorithms introduced are based on the coherent interferometric (CINT) imaging functional, which can be viewed as a smoothed version of travel-time migration. The smoothing gives statistical stability to the image but it also causes blurring. The trade-off between statistical stability and blurring is optimized with an adaptive version of CINT. The algorithm for optimal illumination and for selective array imaging uses CINT. It is a constrained optimization problem that is based on the quality of the image obtained with adaptive CINT. The resulting optimal illuminations and selectivity improve the resolution of the images significantly, as can be seen in the numerical simulations presented in the paper.

Abstract: A touch panel controller ( 3 ) includes: a drive section ( 4 ); a differential amplifier ( 5 ); variable integral capacitors (Cint 1 , Cint 2 ); and a capacitance control section ( 6 ) that controls the variable integral capacitors (Cint 1 , Cint 2 ) so as to correct line dependency of capacitors (C 31 to C 34 , C 41 to S 44 )