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The topology of a mobile ad-hop network can be formed by varying transmission power of each node and this topology can be changed frequently by the mobility of nodes. In this paper, we give a detailed analysis of a direction-based distributed topology control algorithm, termed as HCTC(hill climbing topology control). HCTC is presented for improving connectivity and conserving energy over mobile ad-hop wireless networks. Besides outdoor environment which can use GPS information, applying indoor environment we do not assume that nodes have GPS information available; rather, it depends only on directional information.(Angle of Arrival) HCTC is motivated by the stochastic property of the RWP(random waypoint) mobility model(called border effect); we consider that the border effect can affect a node degree of each node in the deployment region and verify it using an analytical model(fDEG). We also devised HCTCREF algorithm to confirm the topology which formed by proposed algorithm.(HCTC). HCTCREF can verify the direction of reference point which determined by HCTC. Simulation results are presented to demonstrate a set of optimization that further reduce power consumption and prove that they retain robust network connectivity.

ZnO is used as a transparent conducting oxide (TCO) for the front electrode in silicon thin film solar cells because of its low resistivity and high optical transmittance. Hydrogenated Al-doped zinc oxide (AZO:H) thin films were grown on glass by rf magnetron sputtering using a ceramic target (98 wt. % ZnO, 2 wt.% Al 2 O 3 ) in H 2 /Ar ambient. We changed the ratio of H 2 /(Ar+H 2 ) and the substrate temperature from RT to 250 °C. As results, a resistivity of 3.21 × 10−4 Ω·cm was obtained at the 2% H 2 with the substrate temperature of 150□. UV-measurement showed that the optical transmission of AZO:H films was above 85% in the visible range with a widened optical band gap. After deposition, AZO:H films were etched in diluted HCl (0.5%) to investigate the variation of optical properties and surface morphology. The etched films had excellent scattering properties (spectral haze: 52%) and low reflectance. We will present results that demonstrate an improved light trapping due to the textured surface by an etching technique.

Passivation is the one of important factors in the solar cells. The measurement of effectiveness of the passivation layer was based on quasi-steady-state photoconductance. In the case of the sample which was passivated using p-type amorphous silicon(a-Si:H), the minority carrier lifetime was 8.9μs. When the passivation layer was intrinsic a-Si:H, the minority carrier lifetime was 221.3μs. Considering the minority carrier lifetimes of both samples, silicon heterojunction solar cells were fabricated with and without intrinsic a-Si:H layer. the efficiency of the sample passivated with intrinsic amorphous silicon was 13.52%, whereas it was only 11.58% when this layer was not employed.

Nanogap electrodes-based dielectric spectroscopy is introduced to create ultrasensitive biomolecular sensors by minimizing the effects of electrode polarization. The electrode polarization is a major source of error in determining the impedance of biological samples in solution. The unwanted double layer impedance due to the electrode polarization impedance. is caused by the accumulation of ions on the surface of electrode. This effect becomes more dominant in low frequency region (< 1 kHz). In this paper we describe nanogap electrodes-based biomolecular measurements that can minimize electrode polarization effects since the double layers overlap and potential drop inside of the electrode gap can be reduced in nanoscale (

This paper reports Monte Carlo calculation of the bimolecular reaction of extended defects which successfully predicts both the as-implanted impurity profiles (SIMS) and the diffusion profiles for a wide range of implant and annealing conditions. We developed a general kinetic model of extended defects, which explicitly takes the time evolution of size density of extended defects into account in an effort to cover a broad range of behaviors. Our Monte Carlo calculation is in quantitative agreement with the experimental deactivation data and successfully reproduces the rapid deactivation at the beginning phase followed by slow deactivation thereafter.