On the diagnostic emulation technique and its use in the AIRLAB

An aid is presented for understanding and judging the relevance of the diagnostic emulation technique to studies of highly reliable, digital computing systems for aircraft. A short review is presented of the need for and the use of the technique as well as an explanation of its principles of operation and implementation. Details that would be needed for operational control or modification of existing versions of the technique are not described

Effective versus Statutory Taxation: Measuring Effective Tax Administration in Transition Economies

Wide differences between effective or realised average tax rates and tax yields that would result if statutory tax rates were strictly applied indicate tax compliance and collection problems. Due to the greater politicisation of tax systems in transition economies (TEs), we would expect the shortfalls in effective tax yields for TEs to be larger than a benchmark for the mature market economies where tax systems are well established, the administrative capacity is stronger and tax arrears are tolerated less frequently. The methodology involves calculating an effective/statutory (E/S) tax ratio. Initial results indicate that the leading TEs have E/S ratios similar to the EU average. We find a positive correlation between progress in transition and effective tax administration, as measured by our E/S ratio. For slow reformers, the effectiveness of tax collection appears to vary with the extent of state control. Those TEs that have maintained the apparatus of the state have done well in tax collection compared to those countries where there is evidence of state decay. This raises a number of broad policy issues relating to the speed of transition, the interaction of politics and economic reforms, the capacity of the state to govern and the need for market institutions to develop.http://deepblue.lib.umich.edu/bitstream/2027.42/39731/3/wp347.pd

Direct protonation of the W–H bonds of Bis(pentamethylcyclopentadienyl)tungsten dihydride

Protonation of (C_5Me_5)_2 WH_2 to give [(C_5Me_5)_2WH_3]+ is proposed to occur by attack at both W–H bonds rather than by direct attack at the d^2 metal centre

Long-term polarimetric observations of OH127.8+0.0

OH 1612 and 1667 MHz masers from the well known object OH127.8+0.0 were mon- itored in full-polarization mode over a period of 6.5 years and mapped with MERLIN at one epoch. The OH variability pattern of the star is typical of extremely long- period AGB stars. The distance determined from the 1612 MHz light curve and a new measurement of the angular radius is 3.87 (0.28) kpc. At both frequencies, the flux of polarized emission tightly follows the total flux variations while, the degrees of circu- lar and linear polarization are constant within measurement accuracy.. There is net polarization at both lines. The magnetic field strength estimated from a likely Zeeman pair is -0.6 mG at the distance of 5400 au from the star.At the near and far sides of the envelope, the polarization vectors are well aligned implying a regular structure of the magnetic field. The polarization characteristics of the OH maser emission suggest a radial magnetic field which is frozen in the stellar wind.Comment: 12 pages, 9 figure

SMALL FARMS AND SUSTAINABLE DEVELOPMENT: IS SMALL MORE SUSTAINABLE?

A new, post-industrial, paradigm for agriculture is emerging under the concept of sustainable agriculture. The sustainability paradigm has emerged to solve problems created by the industrial model, primarily environmental pollution and resource base degradation. The role of farm size in this transformation to a more sustainable agriculture is the issue addressed. Using a descriptive approach, and relying on a survey of the literature including emerging paradigms and observations, we conclude that, from a sustainability perspective, the smallest effective size will be the most competitive size for farms, as for other knowledge-based enterprises of the future.Agriculture, Farm size, Paradigms, Sustainability, Environmental Economics and Policy, Farm Management,

Effective versus Statutory Taxation: Measuring Effective Tax Administration in Transition Economies

Wide differences between effective or realised average tax rates and tax yields that would result if statutory tax rates were strictly applied indicate tax compliance and collection problems. Due to the greater politicisation of tax systems in transition economies (TEs), we would expect the shortfalls in effective tax yields for TEs to be larger than a benchmark for the mature market economies where tax systems are well established, the administrative capacity is stronger and tax arrears are tolerated less frequently. The methodology involves calculating an effective/statutory (E/S) tax ratio. Initial results indicate that the leading TEs have E/S ratios similar to the EU average. We find a positive correlation between progress in transition and effective tax administration, as measured by our E/S ratio. For slow reformers, the effectiveness of tax collection appears to vary with the extent of state control. Those TEs that have maintained the apparatus of the state have done well in tax collection compared to those countries where there is evidence of state decay. This raises a number of broad policy issues relating to the speed of transition, the interaction of politics and economic reforms, the capacity of the state to govern and the need for market institutions to develop.statutory taxation, average tax rate, tax collection, effective administration, transition economies

Discovery of a Shell of Neutral Atomic Hydrogen Surrounding the Carbon Star IRC+10216

We have used the Robert C. Byrd Green Bank Telescope to perform the most sensitive search to date for neutral atomic hydrogen (HI) in the circumstellar envelope (CSE) of the carbon star IRC+10216. Our observations have uncovered a low surface brightness HI shell of diameter ~1300" (~0.8 pc), centered on IRC+10216. The HI shell has an angular extent comparable to the far ultraviolet-emitting astrosphere of IRC+10216 previously detected with the GALEX satellite, and its kinematics are consistent with circumstellar matter that has been decelerated by the local interstellar medium. The shell appears to completely surround the star, but the highest HI column densities are measured along the leading edge of the shell, near the location of a previously identified bow shock. We estimate a total mass of atomic hydrogen associated with IRC+10216 CSE of M_HI~3x10e-3 M_sun. This is only a small fraction of the expected total mass of the CSE (<1%) and is consistent with the bulk of the stellar wind originating in molecular rather than atomic form, as expected for a cool star with an effective temperature T_eff<~2200 K. HI mapping of a 2 deg x 2 deg region surrounding IRC+10216 has also allowed us to characterize the line-of-sight interstellar emission in the region and has uncovered a link between diffuse FUV emission southwest of IRC+10216 and the Local Leo Cold Cloud.Comment: Accepted to MNRAS. 16 pages. A version with full resolution figures may be found at http://www.haystack.mit.edu/hay/staff/lmatthew/Matthews_etal_IRC+10216.pd

Interim Service ISDN Satellite (ISIS) network model for advanced satellite designs and experiments

The Interim Service Integrated Services Digital Network (ISDN) Satellite (ISIS) Network Model for Advanced Satellite Designs and Experiments describes a model suitable for discrete event simulations. A top-down model design uses the Advanced Communications Technology Satellite (ACTS) as its basis. The ISDN modeling abstractions are added to permit the determination and performance for the NASA Satellite Communications Research (SCAR) Program