Polarimetric detection of objects buried in snowpack by a syntheticaperture FM-CW radar

Presents experimental results of polarimetric detection of objects buried in a natural snowpack by a synthetic aperture FM-CW radar. First, the principle of polarimetric imaging in the Co- and Cross(X)-pol radar channels is outlined based on the scattering matrix and the characteristic polarization states for a specific target. Then, polarimetric measurements were carried out to detect objects buried in a natural snowpack 230 cm deep. The targets included two orthogonally placed metallic plates, an ice layer within the snowpack, and a human body. It is shown that the polarimetric FM-CW radar clearly enhances target signatures and that it serves to significantly improve detection in snowpack. Several polarimetric detection results are displayed, demonstrating the potential capability of characteristic polarization imaging and the usefulness of FM-CW radar     

High-performance solid-electrolyte SOx sensor using MgO-stabilized zirconia tube and Li2SO4---CaSO4---SiO2 auxiliary phase

Solid-electrolyte-based electrochemical SO_x sensors fabricated with MgO-stabilized zirconia and Li₂SO₄---CaSO₄---SiO₂ (4:4:2 in molar ratio) exhibit fairly good sensing characteristics for 2–200 ppm SO₂ in air at 600–750 °C, with the e.m.f. responses following the Nernst equation for the two-electron reduction of SO₂. The 90% response and 90% recovery times to 20 ppm SO₂ are 10 s and 7 min at 650 °C, and 10 s and 3 min at 700 °C, respectively. It is further found that the sensor exhibits excellent selectivity to SO_x in the coexistence of CO₂ and NO_x, and good long-term stability. The sensor is simple in structure, easy to prepare, and quite tough chemically and mechanically. These features should ensure practical use for this SO_x sensor.     

Adaptive DCT coding of video signals

A coefficient-by-coefficient adaptive discrete cosine transform (DCT) is investigated. The interframe DCT has been known to possess an adverse effect in that it generates mosquito and blocking noise. By analyzing DCT for the intraframe and the interframe video signals, a new adaptive intra/interframe DCT is developed. Cases without and with the movement-compensation are discussed separately. Through simulations, it is shown that a substantial improvement gain (1.0-5.0 dB_p-p or 0.2-2.0 dB_p-p, respectively) can be obtained by the new adaptive method. The improvement is brought about by the reduction of the blocking noise conventionally generated by the coarse quantization of the higher order interframe DCT coefficients. By calculating the improvement bound, a further possibility is discussed     

A soft-error-immune 0.9-ns 1.15-Mb ECL-CMOS SRAM with 30-ps 120 klogic gates and on-chip test circuitry

A soft-error-immune, 0.9-ns address access time, 2.0-ns read/write cycle time, 1.15-Mb emitter coupled logic (ECL)-CMOS SRAM with 30-ps 120 k ECL and CMOS logic gates has been developed using 0.3-μm BiCMOS technology. Four key developments ensuring good testability, reliability, and stability are on-chip test circuitry for precise measurement of access time and for multibit parallel testing, a memory-cell test technique for an ECL-CMOS SRAM, a highly stable current source with a simple design using a current mirror, and a soft-error-immune memory cell using a silicon-on-insulator (SOI) wafer. These techniques will be especially useful for making the ultrahigh-speed, high-density SRAM's used as cache and control storages in mainframe computers     

Mode switching control design with initial value compensation andits application to head positioning control on magnetic disk drives

To meet an increasing demand for high performance and large-capacity in magnetic hard disk drives, both fast response and precise positioning are strongly required for the head positioning control. A mode switching control (MSC) system, which includes a track seeking controller, a track following controller, and a switching function, is widely used to meet this requirement. The issue for MSC is to confirm a design method of servo mode switching. This paper proposes the initial value compensation method (IVC). The IVC inputs certain initial values in the controller state variables at mode switching in order to improve the transient response after switching. There are two approaches to determine the values: (1) minimizing a linear-quadratic function of the plant state variables; and (2) cancelling the unfavorable poles of the transfer function between initial values and head position by relocating zeros. Some experimental results are shown to be effective     

Mitochondrial NADH:ubiquinone oxidoreductase (complex I): proximity of the subunits of the flavoprotein and the iron-sulfur protein subcomplexes

The proximities of the three subunits (51, 24, and 9 kDa) of the flavoprotein subcomplex (FP) and five subunits (75, 49, 30, 18, and 13) of the iron-sulfur protein subcomplex (IP) of the bovine NADH: ubiquinone oxidoreductase (complex I) were investigated by cross-linking studies. The cross-linking reagents used were disuccinimidyl tartrate and ethylene glycol bis(succinimidyl succinate). The cross-linked products were identified by sodium dodecyl sulfate gel electrophoresis and immunoblotting with antibodies specific for each subunit. Results showed that the three FP subunits are juxtaposed to one another, and only the 51 kDa subunit of FP is in close proximity to only the 75-kDa subunit of IP. The 75-kDa subunit cross-linked to the 30- and the 13-kDa subunits, the 49-kDa subunit cross-linked to the 30-, 18-, and 13-kDa subunits, and the 30-kDa subunit cross-linked to the 18- and the 13-kDa subunits. No cross-linked products of 75+49-, 75+18-, or 18+13-kDa subunits were detected. These results are consistent with the occurrence of potential electron carriers in FP and IP subunits. These electron carriers are FMN and one iron-sulfur cluster in the 51-kDa subunit, one iron-sulfur cluster in the 24-kDa subunit, and apparently two iron-sulfur clusters in the 75-kDa subunit.     

Optical and electrical properties of hydrogenated amorphous Si1-xGex alloy thin films prepared by planar magnetron sputtering

Thin films of hydrogenated amorphous Si_1-xGe_x were prepared by the r.f. diode planar magnetron sputtering method using composite targets of silicon and germanium in an atmosphere of H₂ diluted with argon. The optical absorption coefficient, d.c. conductivity, photoconductivity and IR transmission spectra were measured, and the dependence of these characteristics on the germanium content x was investigated. For films with x ≈ 0.1, it is found that the dark conductivity decreases and the ratio of the photoconductivity to the dark conductivity increases by about one order of magnitude compared with those for hydrogenated amorphous silicon. This phenomenon seems to be caused by a reorganization of the tetrahedrally bonded structure. Films of this composition are considered to be of interest as an opto-electronic material requiring a high resistance. Photoconductive effects are not observed for films with x > 0.3. This is considered to be due to an alloying effect. The decrease in the amount of bonded hydrogen in the films becomes appreciable for the films with x > 0.6.     

Development of a new type insulation diagnostic method for hot-lineXLPE cables

The authors developed an insulation diagnostic system that makes automatic measurements of the dielectric dissipation factor and DC component in a hot-line XLPE (cross-linked polyethylene) insulated power cable and makes an overall judgement of cable insulation deterioration. This system was tested on XLPE cables in hot-line conditions, the criteria for judgement of insulation deterioration were established based on the results of measurements     

Surface plasmon resonance immunosensor using Au nanoparticle for detection of TNT

In order to develop the fully integrated portable surface plasmon resonance (SPR) system for detection of explosives, the amplification strategy of SPR signal was investigated. Indirect competitive inhibition method allowed the middle-sized SPR sensor to detect trinitrotoluene (TNT) at ppt level. However, this enhanced SPR signal was not high enough to detect TNT at ppt level by a miniaturized SPR sensor. Therefore, localized surface plasmon resonance (LSPR) effect using Au nanoparticle as further signal amplification approach was used. The amplification method of indirect competitive inhibition and LSPR were combined together for fabrication of the immunosurface using Au nanoparticle. TNT detectable range of this immunosurface was from 10 ppt (10 pg/ml) to 100 ppb (100 ng/ml), which was almost comparable to that without Au nanoparticle. The observed resonance angle change due to binding monoclonal TNT antibody (M-TNT Ab) with the immunosurface modified with Au nanoparticle was amplified to four times higher than that in absence of Au nanoparticle.     

A 256-Mb SDRAM using a register-controlled digital DLL

This paper describes the key technologies used in a 256-Mb synchronous DRAM with a clock access time of 1 ns. This DRAM is stable against temperature, voltage, and process variation through the use of a register-controlled digital delay-locked loop (RDLL). The total timing error of the RDLL is about 0.4 ns, sufficient for high frequency operation at 150 to 200 MHz. Unlike most conventional high-density DRAMs, the bit lines are placed above the storage capacitors in this DRAM to relax the design rules of the core area. The noise issues were analyzed and resolved to help implement the technology for mass production of 0.28- to 0.24-μm 200-MHz DRAMs