Mobility management in third-generation all-IP networks

  • Chiussi F.
  • Khotimsky D.
  • Krishnan S.

It is now widely recognized that using IP as the foundation for next-generation mobile networks makes strong economic and technical sense, since it takes advantage of the ubiquitous installed IP infrastructure, capitalizes on the IETF standardization process, and benefits from both existing and emerging IP-related technologies and services. The large-scale ...

Unconventional carrier-mediated ferromagnetism above room temperature in ion-implanted (Ga, Mn)P : C

  • Abernathy C.
  • Chu S.
  • Hebard A.
  • Overberg M.
  • Pearton S.
  • Theodoropoulou N.
  • Wilson R.

Ion implantation of Mn ions into hole-doped GaP has been used to induce ferromagnetic behavior above room temperature for optimized Mn concentrations near 3 at. %. The magnetism is suppressed when the Mn dose is increased or decreased away from the 3 at. % value, or when n-type GaP substrates ...

Predicting operational software availability and its applications to telecommunication systems

  • Pham H.
  • Zhang X.

It is essential to predict customer-perceived software availability during software development and determine when to release the software to maintain a balance among time-to-market, development cost and software quality. This paper presents methods and procedures to predict software failure rates from a user perspective in system test phases and to ...

An improved FPTAS for Restricted Shortest Path

  • Ergun F.
  • Sinha R.
  • Zhang L.

Given a graph with a cost and a delay on each edge, Restricted Shortest Path (RSP) aims to find a min-cost s-t path subject to an end-to-end delay constraint. The problem is NP-hard. In this note we present an FPTAS with an improved running time of O(mn/epsilon) for acyclic graphs, ...

Direct observation of tunneling in KDP using neutron compton scattering

  • Mayers J.
  • Platzman P.
  • Reiter G.

Neutron Compton scattering measurements presented here of the momentum distribution of hydrogen in KH2PO4 just above and well below the ferroelectric transition temperature are sufficiently sensi-tive to show clearly that the proton is coherent over both sites in the high temperature phase, a result that invalidates the commonly accepted order-disorder ...

Microwave resonance of the bubble phases in 1/4 and 3/4 filled high Landau levels

  • Engel L.
  • Lewis R.
  • Pfeiffer L.
  • Tsui D.
  • West K.
  • Ye P.

We have measured the diagonal conductivity, sigma(xx), in the microwave regime of an ultrahigh mobility two dimensional electron system. We find a sharp resonance in Re{[}sigma(xx)] versus frequency when nu>4 and the partial filling of the highest Landau level, nu({*}), is similar to1/4 or 3/4 and temperatures <0.1 K. The ...

Measurement of proton momentum distributions by eV neutron scattering

  • Mayers J.
  • Platzman P.
  • Reiter G.

The method of measuring proton momentum distributions by neutron Compton scattering (NCS) is described. Results on a hydrogen bonded potassium dihydrogen phosphate (KDP) single crystal are presented. For the first time NCS measurements are used to reconstruct the proton momentum, wavefunction and Born-Oppenheimer potential. The results provide clear evidence that ...

Simple setup for simultaneous optical clock recovery and ultra-short sampling pulse generation

  • Kang I.
  • Yan M.

An optical sampling source based on simultaneous clock recovery and optical pulse generation with an electroabsorption modulator is demonstrated. Ultra-short (<670 fs) optical pulses are generated with 280 fs jitter with respect to a 10 Gbit/s data stream. The source is wavelength tunable and could be extended to handle up ...

Photonic integrated receiver for 40 Gbit/s transmission

  • Boardman J.
  • Buhl L.
  • Chandrasekhar S.
  • Freund J.
  • Geary J.
  • Glogovsky K.
  • Grenko J.
  • Kercher T.
  • Ketelsen L.
  • Lentz C.
  • Mason B.
  • Monroe D.
  • Ougazzaden A.
  • Peticolas L.
  • Przybylek G.
  • Rader M.
  • Reynolds L.
  • Sirenko A.
  • Walters F.

A novel 40 Gbit/s optical receiver is presented. The device consists of a waveguide photodiode integrated with a semiconductor optical amplifier. The receiver has a small signal bandwidth of 39 GHz and a conversion gain of more than 800 V/W A back-to-back sensitivity of -17 dBm has been demonstrated for ...

Benefits of bit-to-bit polarisation interleaving for N x 40 Gbit/s all-distributed Raman amplified submarine transmission

  • Corbel E.
  • Le Meur G.

The impact of the polarisation format is studied in N x 40 Gbit/s submarine systems based on distributed Raman amplification including robustness to polarisation mode dispersion (PMD). The best performance is obtained with bit-to-bit polarisation interleaving.

The effects of slider material on the gasification of carbon

  • Harkins C.
  • Lin A.
  • Ramirez A.
  • Sinclair R.

The influence of alumina and titanium carbide, components of magnetic recording sliders, on the carbon gasification reaction was investigated. Pure alumina and titanium carbide powders were each combined with graphite powder and subjected to thermogravimetric analysis (TGA). The molar ratio ranged from 0 to 20 mol percent; graphite powder was ...

X-ray-induced disordering of the dimerization pattern and apparent low-temperature enhancement of lattice symmetry in spinel CuIr(2)S(4)

  • Borissov A.
  • Cheong S.
  • Hor Y.
  • Horibe Y.
  • Ishibashi H.
  • Kiryukhin V.
  • Koo T.
  • Radaelli P.

At low temperatures, spinel CuIr(2)S(4) is a charge-ordered spin-dimerized insulator with triclinic lattice symmetry. We find that x rays induce a structural transition in which the local triclinic structure is preserved, but the average lattice symmetry becomes tetragonal. These structural changes are accompanied by a thousandfold reduction in the electrical ...

Unambiguous state discrimination of coherent states with linear optics: Application to quantum cryptography

  • Van Enk S.

We discuss several methods for unambiguous state discrimination of N symmetric coherent states using linear optics and photodetectors. One type of measurement is shown to be optimal in the limit of small photon numbers for any N. For the special case of N = 4 this measurement can be fruitfully ...

Phase measurements with weak reference pulses

  • Van Enk S.

Quantum state discrimination for two coherent states with opposite phases as measured relative to a reference pulse is analyzed as functions of the intensities of both the signal states and of the reference pulse. This problem is relevant for quantum key distribution with phase encoding. We consider both the optimum ...

Can a more neutral position of the forearm when operating a computer mouse reduce the pain level for VDU operators?

  • Aaras A.
  • Dainoff M.
  • Ro O.
  • Thoresen M.

A prospective epidemiological field study covering a 1-year period has been published (Int. J. Hum.-Comput. Interaction, 1999; 2001). The aim of the study was to investigate if subjects with existing musculoskeletal pain experience a reduction in pain development when using a new mouse design (Anir/Renaissance) which allows a more neutral ...

On prefilter computation for reduced-state equalization

  • Gerstacker W.
  • Huber J.
  • Meyer R.
  • Obernosterer F.

In advanced time-division multiple-access (TDMA) mobile communications systems, reduced-state equalization algorithms have to be employed because high-level modulation is used in order to improves spectral efficiency. Reduced-state equalizers yield only high performance,,if the overall discrete-time system to be equalized is minimum-phase. Therefore,,in general, a discrete-time prefilter has to be inserted ...

Integrated link adaptation and power control to improve error and throughput performance in broadband wireless packet networks

  • Leung K.
  • Wang L.

In this paper, we prove that the problem of maximizing data throughput by adaptive modulation and power control while meeting packet error requirements is NP-complete. A heuristic algorithm for integrated link adaptation and power control is, thus, proposed to achieve specified error rates and to improve overall throughput for real-time ...

Spectral efficiency of FDMA/TDMA wireless systems with transmit and receive antenna arrays

  • Farrokhi F.
  • Foschini G.
  • Lozano A.
  • Valenzuela R.

In recent years, the ever growing need for higher capacity in wireless systems has fueled the,interest in exploiting the spatial dimension-through the use of antennas rrays-to improve the utilization of the available radio spectrum. As a result, a large number of space-time techniques have been proposed wherein arrays are used ...