This paper discusses a single-phase three-level current source inverter (CSI) driven by a single gate-drive power supply in both chopper and inverter, and its feasibility on grid connected photovoltaic system application. Using this new topology, the complexity of the chopper and inverter circuitry is dramatically reduced by using single gate-drive power supply for all power switches. The circu...

This paper discusses two methodological approaches for combining concurrent programs written in a modular way. The rst one is based on the composition of traces. It is intuitive and simple but evidences the need for a more abstract approach. The second one meets this need. It composes speciications written in a UNITY-like temporal logic, and rests on Abadi and Lamport's composition principle ((...

One popular saying among the elites in Nigeria is that ‘unity of not negotiable’. However, going by daily experiences or occurrences and views ordinary Nigerians, statement seems aloof realities all decades her creation. Indeed, there to be more factors pointing need for re-negotiation than a blanket non-negotiability-the sing song elites. The concern this paper explore have made Nigerians unwi...

There are evidences that organic life cannot be reduced to a single biomolecular realm, but, similar to other natural phenomena, rather involves different mechanisms acting at different scale levels, which together define evolvement of the living world. Here we show that a certain biophysical mechanism of general nature, acting at a cellular scale level and above, is also an influential factor ...

We report on the Fermi surfaces and superconducting parameters of CaSb$_2$ single crystals (superconducting below $T_{\text{c}}\sim 1.8~\text{K}$) grown by self-flux method. The frequency de-Haas-van-Alphen Shubnikov-de-Haas oscillations evidences a quasi-two-dimensional (quasi-2D) surface, consistent with one forming Dirac lines predicted first-principles calculations. Measurements in state re...

UNITY is a simple programming logic to reason about distributed systems. It is especially attractive because of its elegant axiomatical style. Since its power is limited, people introduce variants to extends it with various new functionalities. However, in the axiomatical style it is easy to make a mistake: a seemingly very logical new inference rule may turn out to be unsound. Formal verificat...

We define theta functions attached to indefinite quadratic forms over real number fields and prove that these theta functions are Hilbert modular forms by regarding them as specializations of symplectic theta functions. The eighth root of unity which arises under modular transformations is determined explicitly.