The key specification points of lock-in amplifier systems for signal recovery and signal characterisation are reviewed and it is shown how these can be improved and modified by more advanced system design. The configurations of several commercially available systems are described and the facilities available in computer-controlled lock-in systems are discussed briefly, together with some new ap...

We describe a new atom interferometric gravitational wave detector design that can operate in a resonant mode for increased sensitivity. By oscillating the positions of the atomic wavepackets, this resonant detection mode allows for coherently enhanced, narrow-band sensitivity at target frequencies. The proposed detector is flexible and can be rapidly switched between broadband and narrow-band ...

Triple-Helix arrangements of biand trilateral relations can be considered as adaptive ecosystems. During the last decade, we have further developed a Triple-Helix indicator of synergy as reduction of uncertainty in niches that can be shaped among three or more distributions. Reduction of uncertainty can be generated in correlations among distributions of relations, but this (next-order) effect ...

Our focus in this paper is mainly on the GNU/LINUX operting system and the advantages that it affords developing countries seeking to bridge the global digital divide. In the early parts of the paper we argue that, although GNU/LINUX can generate substantial savings when used instead of the proprietary alternative in numerous institutional settings, the most telling opportunities for developing...

Extant literature on the adoption of cloud computing has focused on organizational users, but little is known about how individual users accept cloud computing to fulfill individual needs. To fill the gap, this study draws upon multiple theories to examine factors that influence individuals’ intention to use cloud applications. It shows that a person’s attitude toward cloud applications, subjec...

Usually, it is the software manufacturer who employs verification or testing to ensure that the software embedded in a device meets its main objectives. However, these days we are confronted with the situation that economical or technological reasons might make a manufacturer become interested in the software slightly deviating from its main objective for dubious reasons. Examples include lock-...

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The paper aims at creating an authentication algorithm using visual cryptography that creates a fool-proof lock-key mechanism wherein a lock can be opened by its paired key only and the key cannot be duplicated. In our proposed mechanism we uses a lock and a key, both is one part of given secret image. Every lock-key pair has one associated unique image. The lock is just like a safe door which ...

Atomic operations are a key primitive in parallel computing systems. The standard implementation mechanism for atomic operations uses mutual exclusion locks. In an object-based programming system the natural granularity is to give each object its own lock. Each operation can then make its execution atomic by acquiring and releasing the lock for the object that it accesses. But this ne lock gran...

Traditionally digital lock-in amplifiers sample the input signal at a rate much higher than the lock-in reference frequency and perform the lock-in algorithm with high-speed processors. We present a small and simple digital lock-in amplifier that uses a 20 bit current integrating analogue-to-digital converter interfaced to a microcontroller. The sample rate is set to twice the reference frequen...