Exporting Telecommunications Regulation: The U.S.-Japan Negotiations on Interconnection Pricing

Since 1997, the U.S. government has attempted to use the World Trade Organization (WTO) agreement on telecommunications services as a vehicle for 'exporting' American principles of telecommunications regulation to other nations. The United States took the position in 1997 that the WTO telecommunications agreement requires its signatory nations to follow the practices of the Federal Communications Commission (FCC) on telecommunications regulatory policy. Subsequently, the Office of the U.S. Trade Representative (USTR) has sought to influence, under the implicit threat of trade sanctions, Japan's domestic regulatory policy on the pricing of mandatory competitor access to the unbundled elements of the local network belonging to the operating companies of Nippon Telegraph and Telephone Corporation (NTT). In this Article, we examine the substantive difficulties of engrafting the FCC's interconnection policy onto the telecommunications marketplace of another nation. For more than five years, many American experts on telecommunications policy have disagreed whether American consumers have benefited from the very FCC policies that the USTR would have Japanese regulators emulate. The USTR's initiative appears to ignore that the transition to costoriented rates for interconnection and retail telecommunications services has been a difficult and unfinished process in the United States; that the cost models used by the FCC to set interconnection prices have significant deficiencies; that actual interconnection prices both within and outside the United States diverge considerably from the estimates of the FCC's cost models; that variations across countries in the prices of inputs have a significant effect on the costs of interconnection; and that, with respect to depreciation in particular, regulators treat this cost differently'and, from an economic perspective, more reasonably'in Japan than in the United States. Such substantive economic considerations suggest why the FCC's policy in this area has generated continuous litigation, including two Supreme Court cases, since 1996 and consequently is too unresolved at this point in the American experience for the United States to force on its trading partners. Next, we ask whether the USTR has the detailed knowledge required to negotiate trade agreements on interconnection pricing. We question the propriety of using the USTR to influence the domestic regulatory policy of another country on a topic as complex as the efficient pricing of mandatory access to unbundled network elements. The USTR's power to formulate trade policy on this subject resides in officials who are unlikely to possess the economic expertise and resources necessary to evaluate the consumer-welfare implications of the policies that they would have Japan and other nations adopt. For these reasons, the USTR cannot credibly make the interconnection pricing policies of another nation a legitimate concern of U.S. trade policy.

Reionization and Cosmology with 21 cm Fluctuations

Measurement of the spatial distribution of neutral hydrogen via the redshifted 21 cm line promises to revolutionize our knowledge of the epoch of reionization and the first galaxies, and may provide a powerful new tool for observational cosmology from redshifts 1<z<4 . In this review we discuss recent advances in our theoretical understanding of the epoch of reionization (EoR), the application of 21 cm tomography to cosmology and measurements of the dark energy equation of state after reionization, and the instrumentation and observational techniques shared by 21 cm EoR and post reionization cosmology machines. We place particular emphasis on the expected signal and observational capabilities of first generation 21 cm fluctuation instruments.Comment: Invited review for Annual Review of Astronomy and Astrophysics (2010 volume

A New Kinematic Distance Estimator to the LMC

The distance to the Large Magellanic Cloud (LMC) can be directly determined by measuring three of its properties, its radial-velocity field, its mean proper motion, and the position angle \phi_ph of its photometric line of nodes. Statistical errors of 2% are feasible based on proper motions obtained with any of several proposed astrometry satellites, the first possibility being the Full-Sky Astrometric Mapping Explorer (FAME). The largest source of systematic error is likely to be in the determination of \phi_ph. I suggest two independent methods to measure \phi_ph, one based on counts of clump giants and the other on photometry of clump giants. I briefly discuss a variety of methods to test for other sources of systematic errors.Comment: submitted to ApJ, 13 page

A 490 GHz planar circuit balanced Nb-Al2_\mathbf{2}O3_{\mathbf{3}}-Nb quasiparticle mixer for radio astronomy: Application to quantitative local oscillator noise determination

This article presents a heterodyne experiment which uses a 380-520 GHz planar circuit balanced Nb-$\mathrm{Al_2O_3}$-Nb superconductor-insulator-superconductor (SIS) quasiparticle mixer with 4-8 GHz instantaneous intermediate frequency (IF) bandwidth to quantitatively determine local oscillator (LO) noise. A balanced mixer is a unique tool to separate noise at the mixer's LO port from other noise sources. This is not possible in single-ended mixers. The antisymmetric IV characteristic of a SIS mixer further helps to simplify the measurements. The double-sideband receiver sensitivity of the balanced mixer is 2-4 times the quantum noise limit $h\nu/k_B$ over the measured frequencies with a maximum LO noise rejection of 15 dB. This work presents independent measurements with three different LO sources that produce the reference frequency but also an amount of near-carrier noise power which is quantified in the experiment as a function of the LO and IF frequency in terms of an equivalent noise temperature $T_{LO}$. In a second experiment we use only one of two SIS mixers of the balanced mixer chip, in order to verify the influence of near-carrier LO noise power on a single-ended heterodyne mixer measurement. We find an IF frequency dependence of near-carrier LO noise power. The frequency-resolved IF noise temperature slope is flat or slightly negative for the single-ended mixer. This is in contrast to the IF slope of the balanced mixer itself which is positive due to the expected IF roll-off of the mixer. This indicates a higher noise level closer to the LO's carrier frequency. Our findings imply that near-carrier LO noise has the largest impact on the sensitivity of a receiver system which uses mixers with a low IF band, for example superconducting hot-electron bolometer (HEB) mixers.Comment: 13 pages, 8 figures, 2 tables, see manuscript for complete abstrac

A Radio Spectral Line Study of the 2-Jy IRAS-NVSS Sample: Part I

We present results from an on-going survey for the HI 21 cm line and the OH 18 cm lines in IR galaxies with the Arecibo 305 m Radio Telescope. The observations of 85 galaxies extracted from the 2 Jy IRAS-NVSS sample in the R.A. (B1950) range 20 h-00 h are reported in this paper. We detected the HI 21 cm line in 82 of these galaxies, with 18 being new detections, and the OH 18 cm lines in 7 galaxies, with 4 being new detections. In some cases, the HI spectra show the classic double-horned or single-peaked emission profiles. However, the majority exhibit distorted HI spectral features indicating that the galaxies are in interacting and/or merging systems. From these HI and OH observations, various properties of the sample are derived and reported.Comment: 38 pages, 7 figures, 9 tables. Accepted for publication in A

A large local rotational speed for the Galaxy found from proper-motions: Implications for the mass of the Milky-Way

Predictions from a Galactic Structure and Kinematic model are compared to the absolute proper-motions of about 30,000 randomly selected stars with $9 < B_{\rm J} \le 19$ derived from the Southern Proper-Motion Program (SPM) toward the South Galactic Pole. The absolute nature of the SPM proper-motions allow us to measure not only the relative motion of the Sun with respect to the local disk, but also, and most importantly, the overall state of rotation of the local disk with respect to galaxies. The SPM data are best fit by models having a solar peculiar motion of +5 km~s$^{-1}$ in the V-component (pointing in the direction of Galactic rotation), a large LSR speed of 270 km~s$^{-1}$, and a disk velocity ellipsoid that points towards the Galactic center. We stress, however, that these results rest crucially on the assumptions of both axisymmetry and equilibrium dynamics. The absolute proper-motions in the U-component indicate a solar peculiar motion of $11.0 \pm 1.5$ km~s$^{-1}$, with no need for a local expansion or contraction term. The implications of the large LSR speed are discussed in terms of gravitational mass of the Galaxy inferred from the most recent and accurate determination for the proper-motion of the LMC. We find that our derived value for the LSR is consistent both with the mass of the Galaxy inferred from the motion of the Clouds ($3 - 4 \times 10^{12} M_\odot$ to $\sim 50$ kpc), as well as the timing argument, based on the binary motion of M31 and the Milky Way, and Leo I and the Milky Way ($\ge 1.2 \times 10^{12} M_\odot$ to $\sim 200$ kpc).Comment: 7 pages (AAS Latex macro v4.0), 2 B&W postscript figures, accepted for publication on ApJ, Letters sectio

Supernova Remnants in the Magellanic Clouds. IV. X-Ray Emission from the Largest SNR in the LMC

We present the first X-ray detection of SNR 0450-70.9 the largest known supernova remnant (SNR) in the Large Magellanic Cloud. To study the physical conditions of this SNR, we have obtained XMM-Newton X-ray observations, optical images and high-dispersion spectra, and radio continuum maps. Optical images of SNR 0450-70.9 show a large, irregular elliptical shell with bright filaments along the eastern and western rims and within the shell interior. The interior filaments have higher [S II]/Halpha ratios and form an apparent inner shell morphology. The X-ray emission region is smaller than the full extent of the optical shell, with the brightest X-ray emission found within the small interior shell and on the western rim of the large shell. The expansion velocity of the small shell is ~220 km/s, while the large shell is ~120 km/s. The radio image shows central brightening and a fairly flat radio spectral index over the SNR. However, no point X-ray or radio source corresponding to a pulsar is detected and the X-ray emission is predominantly thermal. Therefore, these phenomena can be most reasonably explained in terms of the advanced age of the large SNR. Using hydrodynamic models combined with a nonequilibrium ionization model for thermal X-ray emission, we derived a lower limit on the SNR age of about 45,000 yr, well into the later stages of SNR evolution. Despite this, the temperature and density derived from spectral fits to the X-ray emission indicate that the remnant is still overpressured, and thus that the development is largely driven by hot gas in the SNR interior.Comment: Accepted for publication in The Astrophysical Journa

Magnetohydrodynamics of Cloud Collisions in a Multi-phase Interstellar Medium

We extend previous studies of the physics of interstellar cloud collisions by beginning investigation of the role of magnetic fields through 2D magnetohydrodynamic (MHD) numerical simulations. We study head-on collisions between equal mass, mildly supersonic diffuse clouds. We include a moderate magnetic field and two limiting field geometries, with the field lines parallel (aligned) and perpendicular (transverse) to the colliding cloud motion. We explore both adiabatic and radiative cases, as well as symmetric and asymmetric ones. We also compute collisions between clouds evolved through prior motion in the intercloud medium and compare with unevolved cases. We find that: In the (i) aligned case, adiabatic collisions, like their HD counterparts, are very disruptive, independent of the cloud symmetry. However, when radiative processes are taken into account, partial coalescence takes place even in the asymmetric case, unlike the HD calculations. In the (ii) transverse case, collisions between initially adjacent unevolved clouds are almost unaffected by magnetic fields. However, the interaction with the magnetized intercloud gas during the pre-collision evolution produces a region of very high magnetic energy in front of the cloud. In collisions between evolved clouds with transverse field geometry, this region acts like a ``bumper'', preventing direct contact between the clouds, and eventually reverses their motion. The ``elasticity'', defined as the ratio of the final to the initial kinetic energy of each cloud, is about 0.5-0.6 in the cases we considered. This behavior is found both in adiabatic and radiative cases.Comment: 40 pages in AAS LaTeX v4.0, 13 figures (in degraded jpeg format). Full resolution images as well as mpeg animations are available at http://www.msi.umn.edu:80/Projects/twj/mhd-cc/ . Accepted for publication in The Astrophysical Journa

Experimental Demonstration of Squeezed State Quantum Averaging

We propose and experimentally demonstrate a universal quantum averaging process implementing the harmonic mean of quadrature variances. The harmonic mean protocol can be used to efficiently stabilize a set of fragile squeezed light sources with statistically fluctuating noise levels. The averaged variances are prepared probabilistically by means of linear optical interference and measurement induced conditioning. We verify that the implemented harmonic mean outperforms the standard arithmetic mean strategy. The effect of quantum averaging is experimentally tested both for uncorrelated and partially correlated noise sources with sub-Poissonian shot noise or super-Poissonian shot noise characteristics.Comment: 4 pages, 5 figure