Capacity of a Class of State-Dependent Orthogonal Relay Channels

The class of orthogonal relay channels in which the orthogonal channels connecting the source terminal to the relay and the destination, and the relay to the destination, depend on a state sequence, is considered. It is assumed that the state sequence is fully known at the destination while it is not known at the source or the relay. The capacity of this class of relay channels is characterized, and shown to be achieved by the partial decode-compress-and-forward (pDCF) scheme. Then the capacity of certain binary and Gaussian state-dependent orthogonal relay channels are studied in detail, and it is shown that the compress-and-forward (CF) and partial-decode-and-forward (pDF) schemes are suboptimal in general. To the best of our knowledge, this is the first single relay channel model for which the capacity is achieved by pDCF, while pDF and CF schemes are both suboptimal. Furthermore, it is shown that the capacity of the considered class of state-dependent orthogonal relay channels is in general below the cut-set bound. The conditions under which pDF or CF suffices to meet the cut-set bound, and hence, achieve the capacity, are also derived.Comment: This paper has been accepted by IEEE Transactions on Information Theor

Distortion Exponent in MIMO Fading Channels with Time-Varying Source Side Information

Transmission of a Gaussian source over a time-varying multiple-input multiple-output (MIMO) channel is studied under strict delay constraints. Availability of a correlated side information at the receiver is assumed, whose quality, i.e., correlation with the source signal, also varies over time. A block-fading model is considered for the states of the time-varying channel and the time-varying side information; and perfect state information at the receiver is assumed, while the transmitter knows only the statistics. The high SNR performance, characterized by the \textit{distortion exponent}, is studied for this joint source-channel coding problem. An upper bound is derived and compared with lowers based on list decoding, hybrid digital-analog transmission, as well as multi-layer schemes which transmit successive refinements of the source, relying on progressive and superposed transmission with list decoding. The optimal distortion exponent is characterized for the single-input multiple-output (SIMO) and multiple-input single-output (MISO) scenarios by showing that the distortion exponent achieved by multi-layer superpositon encoding with joint decoding meets the proposed upper bound. In the MIMO scenario, the optimal distortion exponent is characterized in the low bandwidth ratio regime, and it is shown that the multi-layer superposition encoding performs very close to the upper bound in the high bandwidth expansion regime.Comment: Submitted to IEEE Transactions on Information Theor

Vector Gaussian CEO Problem Under Logarithmic Loss and Applications

We study the vector Gaussian Chief Executive Officer (CEO) problem under logarithmic loss distortion measure. Specifically, $K \geq 2$ agents observe independently corrupted Gaussian noisy versions of a remote vector Gaussian source, and communicate independently with a decoder or CEO over rate-constrained noise-free links. The CEO also has its own Gaussian noisy observation of the source and wants to reconstruct the remote source to within some prescribed distortion level where the incurred distortion is measured under the logarithmic loss penalty criterion. We find an explicit characterization of the rate-distortion region of this model. The result can be seen as the counterpart to the vector Gaussian setting of that by Courtade-Weissman which provides the rate-distortion region of the model in the discrete memoryless setting. For the proof of this result, we obtain an outer bound by means of a technique that relies on the de Bruijn identity and the properties of Fisher information. The approach is similar to Ekrem-Ulukus outer bounding technique for the vector Gaussian CEO problem under quadratic distortion measure, for which it was there found generally non-tight; but it is shown here to yield a complete characterization of the region for the case of logarithmic loss measure. Also, we show that Gaussian test channels with time-sharing exhaust the Berger-Tung inner bound, which is optimal. Furthermore, application of our results allows us to find the complete solutions of two related problems: a quadratic vector Gaussian CEO problem with determinant constraint and the vector Gaussian distributed Information Bottleneck problem. Finally, we develop Blahut-Arimoto type algorithms that allow to compute numerically the regions provided in this paper, for both discrete and Gaussian models. We illustrate the efficiency of our algorithms through some numerical examples.Comment: accepted for publication in IEEE Transactions on Information Theor

Alejandro Magno y su visión de la reconstrucción de la Torre de Babilonia

Die zentrale Fragestellung des folgenden Textes ist, welche Gründe Alexander den Großen dazu bewegt haben, 331 v. Chr. nach seinem Einzug in Babylon den kostenintensiven Auftrag zu geben, den Turm von Babylon wiedererrichten zu lassen. Dafür wird die Geschichte, Bedeutung und Funktion des Turmes erörtert, um seine Rolle in der babylonischen Religion einzuordnen. Alexanders Beweggründe waren mindestens dreierlei: Machtdemonstration seiner erst kürzlich erstrittenen Herrschaft, seine Bestrebung, die babylonischen Stadtgötter auf seine Seite zu ziehen und um auf seine Akzeptanz in Babylon als ausländischer König abzuzielenEl artículo trata las razones que forzaron a Alejandro Magno a iniciar la costosa reconstrucción de la Torre de Babilonia después de su entrada en Babilonia en el año 331 a. C. Discute la historia, la importancia y la función de la torre para averiguar su papel en la religión babilónica. Los motivos de Alejandro eran al menos tres: la manifestación de su poder recientemente adquirido, la atracción de los dioses babilónicos a su lado y el deseo de aprobación en Babilonia como rey de origen extranjer

Book Review: TANU Women: Gender and Culture in the Making of Tanganyikan Nationalism, 1955- 1965

Review of TANU Women: Gender and Culture in the Making of Tanganyikan Nationalism, 1955- 1965 by Susan Geige

Joint Source-Channel Coding with Time-Varying Channel and Side-Information

Transmission of a Gaussian source over a time-varying Gaussian channel is studied in the presence of time-varying correlated side information at the receiver. A block fading model is considered for both the channel and the side information, whose states are assumed to be known only at the receiver. The optimality of separate source and channel coding in terms of average end-to-end distortion is shown when the channel is static while the side information state follows a discrete or a continuous and quasiconcave distribution. When both the channel and side information states are time-varying, separate source and channel coding is suboptimal in general. A partially informed encoder lower bound is studied by providing the channel state information to the encoder. Several achievable transmission schemes are proposed based on uncoded transmission, separate source and channel coding, joint decoding as well as hybrid digital-analog transmission. Uncoded transmission is shown to be optimal for a class of continuous and quasiconcave side information state distributions, while the channel gain may have an arbitrary distribution. To the best of our knowledge, this is the first example in which the uncoded transmission achieves the optimal performance thanks to the time-varying nature of the states, while it is suboptimal in the static version of the same problem. Then, the optimal \emph{distortion exponent}, that quantifies the exponential decay rate of the expected distortion in the high SNR regime, is characterized for Nakagami distributed channel and side information states, and it is shown to be achieved by hybrid digital-analog and joint decoding schemes in certain cases, illustrating the suboptimality of pure digital or analog transmission in general.Comment: Submitted to IEEE Transactions on Information Theor

Els serveis lingüístics en el paradigma 2.0

L’article descriu els aspectes tecnològics i socials relacionats amb el que s’ha denominat paradigma 2.0 com a model de treball en les organitzacions, i ho exemplifica amb diverses experiències directament aplicades al treball en els serveis lingüístics

The racial and linguistic elementas of the English language

Citation: Fearon, Estella May. The racial and linguistic elementas of the English language. Senior thesis, Kansas State Agricultural College, 1903.Morse Department of Special CollectionsIntroduction: The English tongue is a member of a great group or family, embracing many seemingly remote tongues. This family originally occupied a large portion of Asia and nearly the whole of Europe. The name given to it at the present time is the Indo-European or Aryan Family. The place where this language was first spoken is not definitely known, although its first home is supposed to have been in parts of southwestern Asia and eastern Europe. Scientific study of the Indo-Europe4an family shows that all branches of it contain certain grammatical and root forms which bear a strong resemblance tone another. For this reason they are supposed to have sprung from a common source. According to the similarity or nearness of relationship the Indo-European family has been divided in to the following branches. I. The Indian. This branch includes the Gypsy, Hindi, Hindustani and Mahratti. Its greatest representative is Sanskrit. The earliest form of the Indian branch goes back to about two thousand years before the Christian era, and its latest except the Sanskrit to about three centuries before that epoch. The Sanskrit is spoken and written by a small priesthood in a limited section, to the present day. The Indian is the oldest known language belonging to the great Indo-European family and probably comes nearest to the primitive speed of all known languages. II. The Iranian. Including as its principal existing representative the Modern Persian and as its ancient branches the Parsi, and the Cuneiform Inscriptions containing records of the reign of Darius, Xerxes and other Persian kings from about 500 B.C. III. The Hellenic. so named from the Hellenes, the inhabitants of Hellas. This embraces ancient Greek and the Atalic, the Doric, the Ionic and particularly the Attic dialects. The existing from is Modern Greek. IV. The Slavonic or Slavo-Lettic

Publishing Standards for Research in Forecasting (Editorial)

When we first began publication of the Journal of Forecasting, we reviewed policies that were used by other journals and also examined the research on scientific publishing. Our findings were translated into a referee's rating form that was published in the journal [Armstrong (1982a)]. These guidelines were favorably received. Most referees used the Referee's Rating Sheet (Exhibit 1 provides an updated version) and some of them wrote to tell us that they found it helpful in communicating the aims and criteria of the journal.publishing standards, research, forecasting