A demonstrative study for the wind and solar hybrid power system

In March 1995, a small scale wind and solar hybrid power system was installed at Ashikaga Institute of Technology. Until now, the authors have acquired the data of the output of the hybrid power plant along with wind speed, wind direction, and the solar radiation, in order to demonstrate a complementary relationship between solar energy and wind energy.After nine months operation of the system, the authors confirmed that there exists a complementary relationship between solar energy and wind energy. We also found, however, that the power output by wind does not have much prospect compared to that by solar cell especially in summer season in Ashikaga area.     

Soft-error-immune switched-load-resistor memory cell

A soft-error-immune switched-load-resistor memory cell especially suitable for ultrahigh-speed bipolar RAM has been developed. The memory cell is composed of upward sidewall base contact structure (SICOS) transistors and shielded Schottky-barrier diodes (SBDs). Alpha-particle-induced noise charges generated in the p^--substrate are completely shielded by n⁺-buried layers of the transistors and the SBDs. Only the noise charges generated in the transistors or the SBDs active regions are gathered in the collectors of the memory cell. The maximum collected noise charge is reduced to a quarter of that of conventional memory cells using SICOS downward transistors and conventional SBDs. Experiments show that this reduction of the collected noise charge increases soft-error immunity to more than 10⁵ times that of conventional memory cells. This result using hot radiation sources does not directly correspond to the real soft-error rate in the field, but demonstrates the realization of an ultrahigh-speed soft-error-immune memory cell     

Fully Radiative Current Path Structure (FRACS) for sub-0.1 μmemitter transistor

A new structure is proposed for bipolar transistors - FRACS (Fully Radiative Current Path Structure). A FRACS transistor has a line emitter and a cylindrical base and collector or a point emitter and a spherical base and collector. Device parameters of the FRACS transistor is obtained by extending the conventional one-dimensional transistor model to a two- or three-dimensional model. In this structure, base transit time is reduced as the emitter size is reduced by radiative collector current flow. Using this model, a general bipolar transistor with a shallow link base is found to increase the cutoff frequency as the emitter size is reduced. The Kirk effect is suppressed in this structure because of the small collector current density at the collector-base junction. The effect was experimentally examined. A cylindrical base was fabricated by thermal diffusion of boron to achieve the FRACS transistor. Cutoff frequency was observed to increase as the emitter size was reduced. Maximum cut-off frequency of 64 GHz was achieved by this transistor with a 25-nm thick base formed by rapid vapor-phase diffusion     

Self-organization based on nonlinear nonequilibrium. Dynamics of autonomous agents

This paper discusses a study on the mechanism of self-organization. A global order is organized by the simple and locally coordinated actions of autonomous agents using only local information, so complex or globally coordinated actions which use global communication and high-level strategies are not necessary. The fundamental factors for establishing a global order using self-organization are a “dissipative structure,” an “autocatalysis mechanism,” and “intentional fluctuations.” If an environment where there are agents has a dissipative structure and those agents have some sort of autocatalysis and intentional fluctuation mechanisms within themselves, it is possible to form a global order for them using only their simple and locally coordinated actions. “The blind-hunger dilemma” is used as an example to simulate the self-organization and coordinated actions of agents. In this simulation environment, there are many ant-like agents which must get energy. However, there is only one small energy supply base, so either an efficient method or the coordinated actions of agents is needed. As a result, the agents using our approach could move and get energy more efficiently than agents using conventional coordination mechanisms involving global communication and high-level strategies. Real World Computing Partnership This work was presented, in part, at the Second International Symposium on Artificial Life and Robotics, Oita, Japan, February 18–20, 1997     

A very small bipolar transistor technology with sidewall polycidebase electrode for ECL-CMOS LSIs

Very small, high-performance, silicon bipolar transistors (SPOTEC) are developed for use in ECL-CMOS LSIs. The transistors are fabricated with a sidewall polycide base; chemical vapor deposition is used to selectively deposit tungsten on the sidewall surface of the polysilicon base. The tungsten is then silicided. This self-aligned polycide technology makes a narrow (0.4-μm wide), low-resistance (7 Ω/□) base electrode possible. Narrow U-groove isolation and narrow collector metallization techniques are used to reduce the transistor area to 10 μm². A shallow E-B junction and base layer have now been formed by using rapid-vapor-phase doping. The resulting transistors have good I-V characteristics without leakage current or high current gain. They have a high cut-off frequency of 37 GHz (53 GHz with pedestal collector ion implantation and thin epitaxial layer) and small junction capacitances. These transistors facilitate the development of very-high-speed, high-density ULSIs     

Causticization of sodium carbonate with rock-salt type magnesium aluminium oxide formed by the thermal decomposition of hydrotalcite-like layered double hydroxide

The causticization behaviour of Na₂CO₃ with rock-salt type oxide, Mg_2(1-x/(2+x) O (M = Al³⁺ and Fe³⁺, x = 0.2 and 0.33), produced by the thermal decomposition of hydrotalcite-like layered double hydroxide was investigated at 30–60°C. The degree of causticization increased with increasing the molar ratio of [rock-salt type oxide]/[Na₂CO₃] and increasing the temperature but decreased with increasing the initial concentration of Na₂CO₃. The causticization behaviour could be adequately described by the equation of anion exchange equilibria between CO₃^2- and OH^? for layered double hydroxide.     

Development of a 1 MV field-emission transmission electron microscope

We developed a 1 MV field-emission transmission electron microscope. This paper reports details and specifications of the instrument. The microscope was designed to obtain a bright and coherent electron beam by using the field emission gun equipped with a pre-accelerating magnetic lens and the high-voltage power supply with high stability (0.5 ppm min(-1)). Using this microscope, the brightness of 1.8 x 10(10) A cm(-2) sr(-1) and the lattice resolution of 49.8 pm were attained.     

Ultra-low-power and high-speed SiGe base bipolar transistors forwireless telecommunication systems

Ultra-low-power and high-speed SiGe base bipolar transistors that can be used in RF sections of multi-GHz telecommunication systems have been developed. The SiGe base and a poly-Si/SiGe base-contact were formed by selective growth in a self-aligned manner. The transistors have a very small base-collector capacitance (below 1 fF for an emitter area of 0.2×0.7 μm) and exhibit a high maximum oscillation frequency (30-70 GHz) at low current (5-100 μA). The power-delay product of an ECL ring oscillator is only 5.1 fJ/gate for a 250-mV voltage swing. The maximum toggle frequency of a one-eighth static divider is 4.7 GHz at a switching current of 68 μA/FF     

Architecture of a Reduction-Based Parallel Inference Machine: PIM-R

This paper presents a highly parallel machine architecture for logic programs. We propose a Reduction-Based Parallel Inference Machine: PIM-R and describe the parallel execution mechanisms for PIM-R to run Prolog and Concurrent Prolog programs and sofware simulation results. PIM-R uses the structure-copy method. It also uses the only reducible goal copy method, a unique process-structuring method, and the reverse compaction method to decrease the amount, of copying and various copyingrelated operations and the number of packets passing through the network. PIM-R architecture features include the distributed shared memory for Concurrent Prolog, network nodes for efficient packet distribution, and the structure memory to store a part of structured data for reducing the copying overhead.