An object-oriented database system Jasmine: implementation,application, and extension

We have devised an object oriented DBMS called Jasmine for advanced applications. The paper describes the implementation, application and extension of Jasmine in detail. We focus on the impact of the design of its object oriented model and language on database implementation technology. We describe what part of traditional relational database technology we extend to handle object oriented features such as object identifiers, complex objects, class hierarchies, and methods. We introduce nested relations to efficiently store and access clustered complex objects. We use hash based methods to efficiently access nonclustered complex objects. We provide user defined functions directly evaluated on page buffers to efficiently process method invocation. We devise object oriented optimization of queries including class hierarchies, complex objects, and method invocation. We incorporate dedicated object buffering to allow efficient access to objects through object identifiers. We also describe nontrivial applications of Jasmine and discuss the validity of object oriented databases. We focus on a constraint management facility, which can be implemented by taking advantage of the extensibility of Jasmine. The facility includes constraint rules, called design goals, for automatic database population required by engineering applications. Finally, we describe a view facility for schema integration also needed by engineering applications in distributed environments. We focus on how we extend Jasmine to implement the facility     

TEM,XPS and SIMS Analyzes on Grain Boundary of Lanthanum Chromites

The morphological characteristics, chromium valence state, and cation transport in the vicinity of grain boundary in La_1-xCa_xCrO₃ were investigated by using TEM/EDS, XPS and SIMS techniques. The width of grain boundary was around 1 nm where anomalous enrichment of calcium was observed. Higher valence state of chromium such as Cr⁶⁺(d⁰) was detected in the grain boundaries whereas Cr³⁺(d³) and Cr⁴⁺(d²) were dominant in the bulk. Very fast interdiffusion of alkaline earths was observed in the Sr²⁺-La_0.75Ca_0.25CrO₃ system. All observed phenomena were correlated by assuming the A-site vacancy which may be induced by the formation of Cr⁶⁺ at grain boundaries.     

Effects of winding connections on characteristics of a five‐phase stepping motor

A method for calculating the single‐step response of five‐phase hybrid stepping motors is obtained. The effects of winding connecting methods—(1) star‐bipolar SB, (2) pentagon PD, and (3) new pentagon NP—on the single‐step response are investigated. By application of the above calculation method, the continuous rotating characteristics are studied. It is found that the maximum slewing pulse rate of NP is higher than that of SB and PD connections, and that the variation of the rotor speed at high speed with the SB and PD connections is larger than that with the NP connection. The effects of the current waveform on the oscillation characteristics and relations between the current waveform and the winding connections are investigated. © 2001 Scripta Technica, Electr Eng Jpn, 136(1): 47–56, 2001     

Study on environmental effect on fatigue and creep-fatigue strength of 316FR stainless steel in sodium at elevated temperature

Low-carbon 316 stainless steel with medium-nitrogen (316FR) is considered as the principal structural material for next generation fast breeder reactor (FBR) plants in Japan. The material strength standard and the creep-fatigue life evaluation method for 316FR have been developed. However, they are based on the results of material tests in air, while actual structural material will be used mainly in liquid sodium environment in the plants. In order to clarify the environmental effect, cyclic bending tests were carried out with and without hold time in sodium. Tested materials were 316FR and conventional 304 and 316 stainless steels. Weld metal of 316FR was also tested. As a result, it was found that fatigue and creep-fatigue lives of 316FR in sodium were larger than those in air and no explicit consideration of the environmental effect is necessary in design. It was also found that the life evaluation method based on the ductility exhaustion concept is applicable to creep-fatigue life assessment in sodium.     

Research on some basic deformations in free forging with robot and servo-press

Due to the disadvantages in casting or hot forging of Ti alloy artificial bones, such as low strength and high energy cost, this paper prompted an alternative method to manufacture individuated artificial bones. Free forging with a 6-axis freedom robot and servo-press could be very economical in the forming of complex shape parts because of its high flexibility and simple die-setting. Based on this system, the authors studied deformations of some basic elements, which could be assembled to artificial bones with complex shape. Firstly, the compression limit and effect of compression parameters on the roundness during reducing diameter process were declared for Al alloy and pure Ti. Secondly, an approximate theoretical equation of bending angle or curvature radius was proposed, and it matches experimental results well. Finally, a dimension prediction equation was presented by considering effect of material anisotropy, and then the ladder part without width spread was manufactured accordingly.     

A case of hemophagocytic syndrome with severe liver injury manifestating adult Still''s disease

We investigated if complement-mediated enhancement of HIV infection occurs in peripheral blood mononuclear cells (PBMC). In 7 experiments, we evaluated the effect of human complement on HIVIIIB infection in vitro. We measured HIV antigen production on day 4 and found that pre-incubation of HIV with complement led to enhanced production of antigen with a median enhancement of 2.5-fold (range 1.1-6.8). This complement-mediated increase in antigen production was statistically significant (p < 0.02). Complement-mediated enhancement of HIV infection was also tested in CD4 cells enriched from PBMC, and CD4 cells persistently gave higher levels of infection enhancement than PBMC. Thus, CD4 cells appear to be sufficient for complement-mediated enhancement of HIV infection to occur. In addition, we tested if it was possible to detect complement-mediated enhancement of primary HIV isolates in PBMC. We tested 3 isolates and found only a minor effect on antigen production (median enhancement 1.2-fold, range 0.6-1.5). Furthermore, addition of HIV-specific antibodies in combination with complement resulted in enhanced antigen production in 2/3 sera tested. However, the combination of complement and antibodies resulted in only a minor increase in enhancement of HIV infection compared to that obtained with complement alone. Finally, we found evidence of complement-mediated enhancement of HIV infection in resting PBMC. In conclusion, we demonstrated that complement-mediated enhancement of HIV infection does occur in vitro in PBMC.     

GaN-based optoelectronic devices on sapphire and Si substrates

A recessed gate AlGaN/GaN high-electron mobility transistor (HEMT) on sapphire (0 0 0 1), a GaN metal-semiconductor field-effect transistor (MESFET) and an InGaN multiple-quantum well green light-emitting diode (LED) on Si (1 1 1) substrates have been grown by metalorganic chemical vapor deposition. The AlGaN/GaN intermediate layers have been used for the growth of GaN MESFET and LED on Si substrates. A two-dimensional electron gas mobility as high as 9260 cm²/V s with a sheet carrier density of 4.8×10¹² cm⁻² was measured at 4.6 K for the AlGaN/GaN heterostructure on the sapphire substrate. The recessed gate device on sapphire showed a maximum extrinsic transconductance of 146 mS/mm and a drain–source current of 900 mA/mm for the AlGaN/GaN HEMT with a gate length of 2.1 μm at 25°C. The GaN MESFET on Si showed a maximum extrinsic transconductance of 25 mS/mm and a drain–source current of 169 mA/mm with a complete pinch-off for the 2.5-μm-gate length. The LED on Si exhibited an operating voltage of 18 V, a series resistance of 300 Ω, an optical output power of 10 μW and a peak emission wavelength of 505 nm with a full-width at half-maximum of 33 nm at 20 mA drive current.