Representations of the Natural World in Old English Poetry

Review of Representations of the Natural World in Old English Poetry, by Jennifer Neville (Cambridge UP, 1999).

Discursive (de)legitimation of a contested Finnish greenfield investment project in Latin America

Despite the central role of legitimacy in corporate social responsibility debate, little is known of subtle meaning-making processes through which social actors attempt to establish or de-establish legitimacy for socially contested corporate undertakings, and through which they, at the same time, struggle to define the proper social role and responsibility of corporations. We investigated these processes in the context of the intense socio-political conflict around the Finnish forest industry company Metsa¨-Botnia’s world-scale pulp mill in Uruguay. A critical discursive analysis of Finnish media texts highlights three types of struggle that characterized the media coverage: legalistic argumentation, truth fights, and political battles. Interestingly, this case illustrates how the corporate representatives — with the help of the national media — tend to frame the issue in legalistic terms, emphasize their expert knowledge in technical and environmental evaluations, and distance themselves from political disputes. We argue that similar tendencies are likely to characterize corporate social responsibility debates more generally.

Wireless Network-Coded Bidirectional Relaying Using Latin Squares for M-PSK Modulation

The design of modulation schemes for the physical layer network-coded two-way relaying scenario is considered with a protocol which employs two phases: multiple access (MA) phase and broadcast (BC) phase. It was observed by Koike-Akino et al. that adaptively changing the network coding map used at the relay according to the channel conditions greatly reduces the impact of MA interference which occurs at the relay during the MA phase and all these network coding maps should satisfy a requirement called the exclusive law. We show that every network coding map that satisfies the exclusive law is representable by a Latin Square and conversely, that this relationship can be used to get the network coding maps satisfying the exclusive law. The channel fade states for which the minimum distance of the effective constellation at the relay become zero are referred to as the singular fade states. For M - PSK modulation (M any power of 2), it is shown that there are (M-2/4 - M/2 + 1) M singular fade states. Also, it is shown that the constraints which the network coding maps should satisfy so that the harmful effects of the singular fade states are removed, can be viewed equivalently as partially filled Latin Squares (PFLS). The problem of finding all the required maps is reduced to finding a small set of maps for M - PSK constellations (any power of 2), obtained by the completion of PFLS. Even though the completability of M x M PFLS using M symbols is an open problem, specific cases where such a completion is always possible are identified and explicit construction procedures are provided. Having obtained the network coding maps, the set of all possible channel realizations (the complex plane) is quantized into a finite number of regions, with a specific network coding map chosen in a particular region. It is shown that the complex plane can be partitioned into two regions: a region in which any network coding map which satisfies the exclusive law gives the same best performance and a region in which the choice of the network coding map affects the performance. The quantization thus obtained analytically, leads to the same as the one obtained using computer search for M = 4-PSK signal set by Koike-Akino et al., when specialized for Simulation results show that the proposed scheme performs better than the conventional exclusive-OR (XOR) network coding and in some cases outperforms the scheme proposed by Koike-Akino et al.

Physical layer network coding for two-way relaying with QAM and latin squares

In the design of modulation schemes for the physical layer network-coded two way relaying scenario with two phases (Multiple access (MA) Phase and Broadcast (BC) Phase), it was observed by Koike-Akino et al. that adaptively changing the network coding map used at the relay according to the channel conditions greatly reduces the impact of multiple access interference and all these network coding maps should satisfy a requirement called the exclusive law. In [11] the case in which the end nodes use M-PSK signal sets is extensively studied using Latin Squares. This paper deals with the case in which the end nodes use square M-QAM signal sets. In a fading scenario, for certain channel conditions, termed singular fade states, the MA phase performance is greatly reduced. We show that the square QAM signal sets lead to lesser number of singular fade states compared to PSK signal sets. Because of this, the complexity at the relay is enormously reduced. Moreover lesser number of overhead bits are required in the BC phase. We find the number of singular fade states for PAM and QAM signal sets used at the end nodes. The fade state γejθ = 1 is a singular fade state for M-QAM for all values of M and it is shown that certain block circulant Latin Squares remove this singular fade state. Simulation results are presented to show that QAM signal set perform better than PSK.

Wireless network-coded three-way relaying using Latin Cubes

The design of modulation schemes for the physical layer network-coded three-way wireless relaying scenario is considered. The protocol employs two phases: Multiple Access (MA) phase and Broadcast (BC) phase with each phase utilizing one channel use. For the two-way relaying scenario, it was observed by Koike-Akino et al. [4], that adaptively changing the network coding map used at the relay according to the channel conditions greatly reduces the impact of multiple access interference which occurs at the relay during the MA phase and all these network coding maps should satisfy a requirement called exclusive law. This paper does the equivalent for the three-way relaying scenario. We show that when the three users transmit points from the same 4-PSK constellation, every such network coding map that satisfies the exclusive law can be represented by a Latin Cube of Second Order. The network code map used by the relay for the BC phase is explicitly obtained and is aimed at reducing the effect of interference at the MA stage.

Wireless bidirectional relaying and Latin squares

The design of modulation schemes for the physical layer network-coded two way relaying scenario is considered with the protocol which employs two phases: Multiple access (MA) Phase and Broadcast (BC) Phase. It was observed by Koike-Akino et al. that adaptively changing the network coding map used at the relay according to the channel conditions greatly reduces the impact of multiple access interference which occurs at the relay during the MA Phase and all these network coding maps should satisfy a requirement called the exclusive law. We show that every network coding map that satisfies the exclusive law is representable by a Latin Square and conversely, and this relationship can be used to get the network coding maps satisfying the exclusive law. Using the structural properties of the Latin Squares for a given set of parameters, the problem of finding all the required maps is reduced to finding a small set of maps for M-PSK constellations. This is achieved using the notions of isotopic and transposed Latin Squares. Furthermore, the channel conditions for which the bit-wise XOR will perform well is analytically obtained which holds for all values of M (for M any power of 2). We illustrate these results for the case where both the end users use QPSK constellation.

Influence of Spatial Variability on Pavement Responses Using Latin Hypercube Sampling on Two-Dimensional Random Fields

Although uncertainties in material properties have been addressed in the design of flexible pavements, most current modeling techniques assume that pavement layers are homogeneous. The paper addresses the influence of the spatial variability of the resilient moduli of pavement layers by evaluating the effect of the variance and correlation length on the pavement responses to loading. The integration of the spatially varying log-normal random field with the finite-difference method has been achieved through an exponential autocorrelation function. The variation in the correlation length was found to have a marginal effect on the mean values of the critical strains and a noticeable effect on the standard deviation which decreases with decreases in correlation length. This reduction in the variance arises because of the spatial averaging phenomenon over the softer and stiffer zones generated because of spatial variability. The increase in the mean value of critical strains with decreasing correlation length, although minor, illustrates that pavement performance is adversely affected by the presence of spatially varying layers. The study also confirmed that the higher the variability in the pavement layer moduli, introduced through a higher value of coefficient of variation (COV), the higher the variability in the pavement response. The study concludes that ignoring spatial variability by modeling the pavement layers as homogeneous that have very short correlation lengths can result in the underestimation of the critical strains and thus an inaccurate assessment of the pavement performance. (C) 2014 American Society of Civil Engineers.

Error Correcting Functional Source Coding with Decoder Side Information using Row-Latin Rectangles

The functional source coding problem in which the receiver side information (Has-set) and demands (Want-set) include functions of source messages is studied using row-Latin rectangle. The source transmits encoded messages, called the functional source code, in order to satisfy the receiver's demands. We obtain a minimum length using the row-Latin rectangle. Next, we consider the case of transmission errors and provide a necessary and sufficient condition that a functional source code must satisfy so that the receiver can correctly decode the values of the functions in its Want-set.

Latin hypercube sampling used in the calculation of the fracture probability

The paper proposes Latin hypercube sampling combined with the stratified sampling of variance reduction technique to calculate accurate fracture probability. In the compound sampling, the number of simulations is relatively small and the calculation error is satisfactory.

Apuntes para una teología de la ciudad : en el camino hacia una reflexión interdisciplinaria

Una teología de la ciudad no es un planteo nuevo en el contexto latinoamericano, pero sí un tema no suficientemente profundizado. En un marco de creciente urbanización y de profundos desafíos afrontados por el cristianismo, la ciudad vuelve a reclamar la atención de la pastoral de las iglesias y de la teología. El presente ensayo inicia una reflexión a partir de algunos aportes significativos sobre teología y pastoral urbana en el ámbito de Inglaterra y EE.UU. Asimismo, ofrece algunos senderos teológicos programáticos para una investigación interdisciplinaria, junto a algunas consideraciones relativas al método.

La pobreza de la Iglesia y los signos de los tiempos : Medellín como recepción inacabada del Vaticano II

Resumen: Una teología de los signos de estos tiempos latinoamericanos reclama ser localizada en el horizonte hermenéutico de la recepción del Concilio Vaticano II. La Conferencia de Medellín, como único caso de recepción continental del Concilio y ejercicio colegiado de discernimiento teológico pastoral de los signos de los tiempos, constituye un espacio ejemplar para la reflexión. En Medellín, la pobreza de la Iglesia y la preferencia por los pobres expresan una clave de esta recepción y un criterio al discernir los signos de esos tiempos; esta recepción realizada en Medellín, que puede considerarse fiel, creativa, selectiva e inacabada, pide ser reapropiada.

La paz como un signo de estos tiempos : la Iglesia latinoamericana ante la violencia y el aporte de las mujeres a la paz

Resumen: Esta ponencia forma parte del primer Panel Inaugural del II Congreso de Teólogas latinoamericanas y alemanas “Espacios de Paz”, realizado del 28 al 31 de marzo de 2016. Se aborda el tema de la paz como signo de estos tiempos desde tres claves: el contexto latinoamericano, la centralidad de la violencia en los estudios sobre la paz y su relación con las mujeres como constructoras de paz y víctimas de violencia. La reflexión se organiza en dos partes: primero, se analiza el discernimiento teológicopastoral sobre la paz realizado por la Conferencia de Medellín, en un contexto de subdesarrollo e injusticia caracterizados como violencia institucional y pecado estructural; además, se mencionan en forma breve los desafíos de reconciliación que plantearon los procesos de transición que siguieron a los gobiernos militares y a los conflictos armados internos. En la segunda parte, se enfocan algunos valores y esferas de la paz y la violencia –personal, estructural y cultural–, para considerar el concepto secular y cristiano de “pacificación” (peacebuilding) y los aportes teóricos y prácticos de las mujeres en la construcción de la paz en contextos de violencia.

“Evangelización con espíritu” (EG 261) : la unidad de la teología, la espiritualidad y la pastoral al servicio del anuncio del evangelio: una lectura de la exhortación pastoral Evangelii Gaudium desde la Teología Espiritual

Resumen: Uno de los grandes “maestros en teología” en la Argentina de los últimos tiempos, Lucio Gera (+07.08.2012), cuyo segundo aniversario de fallecido honramos en este número de la revista Teología, hablaba de la ineludible exigencia posconciliar de integrar teología, espiritualidad y pastoral. El capítulo V de Evangelii gaudium, “Evangelizadores con Espíritu” (cf. EG 259ss), se ubica especialmente en este horizonte de convicciones porque tiene un inconfundible contenido teológico, un marcado acento espiritual y una clara orientación y lenguaje pastoral, pero sobre todo en razón de expresar una íntima compenetración entre estas tres dimensiones. En este artículo, que reelabora y amplía una presentación oral en la Jornada Evangelii gaudium, organizada por la Facultad de Teología de la UCA el pasado 5 de junio, se asume el vigor de la propuesta de una “evangelización con espíritu” (EG 261) y se reflexiona, en diálogo con nuestra iglesia local, sobre cuatro aspectos relacionados con ella: 1. una teología de la “evangelización con espíritu”, es decir, “con Espíritu Santo”; 2. una espiritualidad contemplativa: amar la Palabra y gustar ser pueblo; 3. el estilo pastoral mariano de la evangelización; y 4. la danza de la teología, la espiritualidad y la pastoral al servicio de la alegría de evangelizar.