Monolithic arrays of surface emitting laser NOR logic devices

Monolithic, cascadable, laser-logic-device arrays have been realized and characterized. The monolithic surface-emitting laser logic (SELL) device consists of an AlGaAs superlattice lasing around 780 nm connected to a heterojunction phototransistor (HPT) in parallel and a resistor in series. Arrays up to 8×8 have been fabricated, and 2×2 arrays show uniform characteristics. The optical logic output is switched off with 40 μW incident optical input

Monolithic arrays of surface emitting laser NOR logic devices

Monolithic, cascadable, laser-logic-device arrays have been realized and characterized. The monolithic surface-emitting laser logic (SELL) device consists of an AlGaAs superlattice lasing around 780 nm connected to a heterojunction phototransistor (HPT) in parallel and a resistor in series. Arrays up to 8×8 have been fabricated, and 2×2 arrays show uniform characteristics. The optical logic output is switched off with 40 μW incident optical input

Stabilizing the forming process in unipolar resistance switching using an improved compliance current limiter

The high reset current IR in unipolar resistance switching now poses major obstacles to practical applications in memory devices. In particular, the first IR-value after the forming process is so high that the capacitors sometimes do not exhibit reliable unipolar resistance switching. We found that the compliance current Icomp is a critical parameter for reducing IR-values. We therefore introduced an improved, simple, easy to use Icomp-limiter that stabilizes the forming process by drastically decreasing current overflow, in order to precisely control the Icomp- and subsequent IR-values.Comment: 15 pages, 4 figure

Highly stacked 3D organic integrated circuits with via-hole-less multilevel metal interconnects

Multilevel metal interconnects are crucial for the development of large-scale organic integrated circuits. In particular, three-dimensional integrated circuits require a large number of vertical interconnects between layers. Here, we present a novel multilevel metal interconnect scheme that involves solvent-free patterning of insulator layers to form an interconnecting area that ensures a reliable electrical connection between two metals in different layers. Using a highly reliable interconnect method, the highest stacked organic transistors to date, a three-dimensional organic integrated circuits consisting of 5 transistors and 20 metal layers, is successfully fabricated in a solvent-free manner. All transistors exhibit outstanding device characteristics, including a high on/off current ratio of similar to 10(7), no hysteresis behavior, and excellent device-to-device uniformity. We also demonstrate two vertically-stacked complementary inverter circuits that use transistors on 4 different floors. All circuits show superb inverter characteristics with a 100% output voltage swing and gain up to 35 V per V.11Ysciescopu

Demystification of Mizusaki’s α-factor for the positively-deviated defect behavior of hyperstoichiometric oxides

Many hyperstoichiometric (p-type) ternary or higher oxides of present technological interests, e.g., La1-xSrxCrO3-δ exhibit a positive deviation from the ideal defect structure. Mizusaki et al. [1] could beautifully explain the positively-deviated defect structure by introducing an empirical factor α such as ΔHxs=αδ. Here, ΔHxs stands for the excess enthalpy of oxidation reaction involving oxygen vacancies and holes or 1/2 O2+VO••=OOx+2h• . The authors[1] interpreted this α-factor as representing the interactions among lattice ions and defects, but its true physico-chemical face has since remained a mystery notwithstanding so frequent invoking to the defect chemistry stage. It has recently turned out that this factor corresponds to the first order approximation of the hole-degeneracy effect. We will demystify this α-factor in this line. [1] J. Mizusaki, S, Yamauchi, K. Fueki, and A. Ishikawa, “Nonstoichiometry of the perovskite-type oxide La1-xSrxCrO3-δ,” Solid State Ionics 12 (1984) 119

Combining Reinforcement Learning With Genetic Algorithm for Many-To-Many Route Optimization of Autonomous Vehicles

This study introduces an approach for route optimization of many-to-many Demand-Responsive Transport (DRT) services. In contrast to conventional fixed-route transit systems, DRT provides dynamic, flexible, and cost-effective alternatives. We present an algorithm that integrates DRT with the autonomous shuttles at Korea National University of Transportation (KNUT), allowing dynamic route modifications in real-time to accommodate incoming service calls. The algorithm is designed to take into account the shuttle's current position, the destinations of passengers already on board, the current locations and destinations of individuals who have requested shuttle services, and the remaining capacity of the shuttle. The algorithm has been developed to combine genetic algorithms and reinforcement learning. The performance evaluation was conducted using a simulation model that emulates KNUT's campus and the adjoining local community area. The simulation results show significant improvements in two key metrics, specifically the 'Request to Pick-up Time' and 'Request to Drop-off Time' during high-demand periods over the single-shuttle operation. Additional simulation test with random service requests and stochastic passenger walking distances showed the potential adaptability across different settings

A computationally efficient inorganic atmospheric aerosol phase equilibrium model (UHAERO)

A variety of thermodynamic models have been developed to predict inorganic gas-aerosol equilibrium. To achieve computational efficiency a number of the models rely on a priori specification of the phases present in certain relative humidity regimes. Presented here is a new computational model, named UHAERO, that is both efficient and rigorously computes phase behavior without any a priori specification. The computational implementation is based on minimization of the Gibbs free energy using a primal-dual method, coupled to a Newton iteration. The mathematical details of the solution are given elsewhere. The model also computes deliquescence and crystallization behavior without any a priori specification of the relative humidities of deliquescence or crystallization. Detailed phase diagrams of the sulfate/nitrate/ammonium/water system are presented as a function of relative humidity at 298.15 K over the complete space of composition