The paper presents an approach to the speciication and veriication of real-time hybrid systems using Duration Calculus (DC) 11]. By introducing a formula int to DC to express the intervals of time between two ticks of the system clock, it is shown that DC can be used to specify both the digital states and the analog states as well as to reason about time in distributed systems. We illustrate ou...

Recently, lateral resolution of photoemission spectroscopy has been rapidly improving by several types of energy-filtered electron emission microscopes (PEEM) or by focused light sources.1–6) On the other hand, laser-based photoemission spectroscopy facilitates femtosecond time-resolution, revealing the dynamics of electrons and atoms on surfaces.7–11) The combination of lateral and temporal re...

Xe2+ ions can easily be formed by multiphoton absorption in Xe atoms at 0.53 03BCm. At low laser intensities, a laser-Xe atom interaction takes place which generates Xe2+ ions through a 15-photon absorption from Xe atoms. At higher intensities, a laser-Xe+ ion interaction takes place, generating Xe2+ ions through a 10-photon absorption from the Xe+ ion in its ground state. The former process is...

We analyze a sample of bright short bursts from the BATSE 4B-catalog and find that many short bursts are highly variable (δtmin/T ≪ 1, where δtmin is the shortest pulse duration and T is the burst duration). This indicates that it is unlikely that short bursts are produced by external shocks. We also analyze the available (first 1-2 seconds) high resolution (TTE) data of some of the long bursts...

We show, by simple classical arguments, that the explicit time dependence of the ponderomotive potential causes both a shift and a broadening of the photoelectron lines in high-intensity multiphoton experiments. If the laser pulse is short enough, some of the energy from the absorbed photons will be lost by an electron when it separates from the pulse. Since different atoms are ionized at diffe...

UV laser micromachining of metallic materials has been used in microelectronic and other industries. Knowledge and data about the process vary with feature size, material, laser wavelength and pulse duration. This paper reports on experimental and numerical investigation of micromachining of copper using a frequency tripled Nd:YAG laser with 50 ns pulse duration. An axisymmetric model is develo...

A diode-side-pumped, high-energy, high-beam-quality, pulsed solid-state Nd3+:Y3Al5O12 (Nd:YAG) laser with a thermoelectric cooler (TEC) is investigated in this study. The pump laser was a pulsed laser diode array with maximum peak power of 15 kW. A 350 mJ laser pulse was obtained with a wavelength of 1064 nm, a pulse duration of 10 ns, a total electrical-to-optical efficiency of 7.5%, a relativ...

This paper presents an ω-complete proof system for the extension of first order Interval Temporal Logic (ITL, [12, 15, 4]) by a projection operator [16, 11]. Alternative earlier approaches to the axiomatisation of projection in ITL are briefly presented and discussed. An extension of the proof system which is complete for the extension of Duration Calculus (DC , [24]) by projection is also given.

The goal of this paper is to translate (fragments of) the quantified discrete duration calculus QDDC, proposed by P. Pandya, into symbolic acceptors with counters. Acceptors are written in the synchronous programming language Lustre, in order to allow available symbolic verification tools (model-checkers, abstract interpreters) to be applied to properties expressed in QDDC. We show that importa...

The theory of active-passive mode-locked solid-state lasers is developed where the passive mode-locking is achieved by a nonlinear mirror. Steady-state cw numerical solutions are analyzed in detail for the case of a Nd:YAG laser. The steady-state pulse duration can be reduced by an order of magnitude as compared to the pure active modelocking regime.