A Pipeline Interleaved Heterogeneous SIMD Soft Processor Array Architecture for MIMO-OFDM Detection

The most promising way to maintain reliable data transfer across the rapidly fluctuating channels used by next generation multiple-input multiple-output communications schemes is to exploit run-time variable modulation and antenna configurations. This demands that the baseband signal processing architectures employed in the communications terminals must provide low cost and high performance with runtime reconfigurability. We present a softcore-processor based solution to this issue, and show for the first time, that such programmable architectures can enable real-time data operation for cutting-edge standards
such as 802.11n; furthermore, by exploiting deep processing pipelines and interleaved task execution, the cost and performance of these architectures is shown to be on a par with traditional dedicated circuit based solutions. We believe this to be the first such programmable architecture to achieve this, and the combination of implementation efficiency and programmability makes this implementation style the most promising approach for hosting such dynamic architectures.

Application of STOPP and START criteria: interrater reliability among pharmacists

BACKGROUND: Inappropriate prescribing is a well-documented problem in older people. The new screening tools, STOPP (Screening Tool of Older Peoples' Prescriptions) and START (Screening Tool to Alert doctors to Right Treatment) have been formulated to identify potentially inappropriate medications (PIMs) and potential errors of omissions (PEOs) in older patients. Consistent, reliable application of STOPP and START is essential for the screening tools to be used effectively by pharmacists. OBJECTIVE: To determine the interrater reliability among a group of clinical pharmacists in applying the STOPP and START criteria to elderly patients' records. METHODS: Ten pharmacists (5 hospital pharmacists, 5 community pharmacists) were given 20 patient profiles containing details including the patients' age and sex, current medications, current diagnoses, relevant medical histories, biochemical data, and estimated glomerular filtration rate. Each pharmacist applied the STOPP and START criteria to each patient record. The PIMs and PEOs identified by each pharmacist were compared with those of 2 academic pharmacists who were highly familiar with the application of STOPP and START. An interrater reliability analysis using the k statistic (chance corrected measure of agreement) was performed to determine consistency between pharmacists. RESULTS: The median ? coefficients for hospital pharmacists and community pharmacists compared with the academic pharmacists for STOPP were 0.89 and 0.88, respectively, while those for START were 0.91 and 0.90, respectively. CONCLUSIONS: Interrater reliability of STOPP and START tools between pharmacists working in different sectors is good. Pharmacists working in both hospitals and in the community can use STOPP and START reliably during their everyday practice to identify PIMs and PEOs in older patients.

Transient inversion soft X-ray lasers

The collisionally excited transient inversion scheme is shown to produce exceptionally high gain coefficients and gain-length products. Data are presented for the Ne-Like titanium and germanium and Ni-like silver X-ray lasers (XRL's) pumped using a combination of nanosecond and picosecond duration laser pulses. This method leads to a dramatic reduction of the required pump energy and makes down-sizing of XRL's possible, an important prerequisite if they are to become commonly used tools in the Long-term.

Optical source model for the 23.2-23.6 nm radiation from the multielement germanium soft X-ray laser

Distributions of source intensity in two dimensions (designated the source model), averaged over a single laser pulse, based on experimental measurements of spatial coherence, are considered for radiation from the unresolved 23.2/23.6 nm spectral lines from the germanium collisional X-ray laser. The model derives from measurements of the visibility of Young slit interference fringes determined by a method based on the Wiener-Khinchin theorem. Output from amplifiers comprising three and four target elements have similar coherence properties in directions within the horizontal plane corresponding to strong plasma refraction effects and fitting the coherence data shows source dimensions (FWHM) are similar to 26 mu m (horizontal), significantly smaller than expected by direct imaging, and similar to 125 mu m (vertical: equivalent to the height of the driver excitation). (C) 1999 Elsevier Science B.V. All rights reserved.

Time dependence of the spatial coherence of the 23.6- and 23.2-nm radiation from the germanium soft-x-ray laser

The time dependence of the spatial coherence of the combined spectral lines at 23.2 and 23.6 nm from the Ge XXIII collisionally pumped soft-x-ray laser with a double-slab target is examined within a single nanosecond pulse by use of Young's interference fringes and a streak camera. High source intensity is linked with low spatial coherence and vice verse. Calculations of the source intensity, size, and position have also been made; these calculations refer to a single-slab source. Comparison between the observed and calculated intensities, and of the source sizes both calculated and derived from the Young's fringes by interpretation with a Gaussian model of source emission, show good agreement in general trends. (C) 1998 Optical Society of America [S0740-3224(98)01905-5].

Collisional exitation soft X-ray laser at 23.6 nm in a laser-produced cylindrical target

We have tested soft X-ray lasing in neon-like germanium with cylindrical targets where wave guiding and plasma confinement may affect lasing. An intense soft X-ray laser beam of 0.05 MW peak power and a narrow beam divergence (8 mrad) was produced at 23.6 nm with a 4 cm long straight cylindrical target of 0.72 mm inner diameter. Bending the cylindrical target to form a toroidal shape increased the lasing intensity by a factor of 3 accompanied with reduction of the beam divergence from 8 to 6 mrad.