Attenuation

ABSTRACT form only given. Data exchange in many underwater applications such as oceanographic data collection, scientific ocean sampling, pollution and environmental monitoring, disaster prevention, underwater system maintenance, recreational scuba diving, is an exciting task. Due to the reduced visibility (for optical) or high attenuations (for radio) link, in most of the cases the communication between different locations cannot take place. When possible, this limitations are alleviated employing data transmission via cables, a solution that can be employed for both dynamic (e.g. on the scuba divers) or static (e.g. sensor nodes) systems. However, its use assumes that the movement among the different communicating objects is clearly strongly limited. On the other hand, the total lack of the possible communication among the divers substantially reduces the possibility of preventing dangers, avoiding the considered activity to be conducted in safe way.

... Swarm intelligence is a member of artificial intelligence that study intelligence behaviour of groups rather than of individuals, such as social behaviour of insect like ants, bees, wasp, termites and fish. ... Figure 8: Pole-zero plot. REFERENCES Andries P. Engelbrecht. ...

This paper discusses both occupational health risks to workers and environmental health risks to residents and workers. The report presents an overview of the available health literature for causes of diseases, injuries, and accidents from solid waste management collection, treatment, and disposal technologies. Illnesses discussed include infectious diseases, allergies, respiratory damage, and cancers. Some diseases are derived from direct ingestion of infectious micro-organisms, others involve infection through contamination of the food chain, whereby animals or other vectors have ingested infectious micro-organisms. Injuries include joint and spinal damage, fractures, puncture wounds, damage to eyes and ears. Accidents include slides from unstable disposal piles, cave-ins of disposal site surfaces, fires, explosions, being caught in processing equipment, and being run over by mobile equipment. As the next steps toward improving occupational and environmental health and safety in s...

In this work, we present a method for approximating constrained maximum entropy (ME) reconstructions of SPECT data with modifications to a block-iterative maximum a posteriori (MAP) algorithm. Maximum likelihood (ML)-based reconstruction algorithms require some form of noise smoothing. Constrained ME provides a more formal method of noise smoothing without requiring the user to select parameters. In the context of SPECT, constrained ME seeks the minimum-information image estimate among those whose projections are a given distance from the noisy measured data, with that distance determined by the magnitude of the Poisson noise. Images that meet the distance criterion are referred to as feasible images. We find that modeling of all principal degrading factors (attenuation, detector response, and scatter) in the reconstruction is critical because feasibility is not meaningful unless the projection model is as accurate as possible. Because the constrained ME solution is the same as a MAP solution for a particular value of the MAP weighting parameter, beta, the constrained ME solution can be found with a MAP algorithm if the correct value of beta is found. We show that the RBI-MAP algorithm, if used with a dynamic scheme for estimating beta, can approximate constrained ME solutions in 20 or fewer iterations. We compare results for various methods of achieving feasible images on a simulation of Tl-201 cardiac SPECT data. Results show that the RBI-MAP ME approximation provides images and quantitative estimates close to those from a slower algorithm that gives the true ME solution. Also, we find that the ME results have higher spatial resolution and greater high-frequency noise content than a feasibility-based stopping rule, feasibility-based low-pass filtering, and a quadratic Gibbs prior with beta selected according to the feasibility criterion. We conclude that fast ME approximation is possible using either RBI-MAP with the dynamic procedure or a feasibility-based stopping rule, and that such reconstructions may be particularly useful in applications where resolution is critical.

Three generations of empirical scaling equations, developed by the Strong Motion Research Group at University of Southern California in the 1970's, 1980's and 1990's, for the attenuation and scaling of spectral amplitudes of strong ground motion are reviewed. Semi-theoretical extrapolation functions for extending these empirical scaling equations to high and low frequencies are also presented. For brevity, only equations and illustrations which describe the relative response spectrum amplitudes are shown, but the methods and procedures presented are also applicable to scaling of Fourier amplitude spectra, for which complete corresponding references are also included.

Este artículo analiza el poemario del manchego José Corredor-Matheos, Sin ruido (2013), desde la óptica de la lítote como figura de atenuación y, con mayor alcance, como meca-nismo que subsume ciertos rasgos transversales característicos de la poética de madu-rez del autor. Dichos rasgos redundan en la coherencia de su poética y el compromiso con la poesía de la simplicidad y el despojamiento, en su ubicación en las formas y con las formas, y en la exploración de la negación como mecanismo de profundización semántica y ampliación de matices ante la contundencia de la vejez y la muerte.

This paper analyzes Sin ruido (2013), the poetry book by the Spanish poet from Castile-La Mancha, José Corredor-Matheos. Litotes is approached both as a figure for attenuation and, beyond that, as a mechanism that subsumes certain distinctive traits of his poetics across his most mature production. Such traits reinforce the author's consistency and his commitment to the poetry of simplicity and divestment, its positioning in form and with form, and the exploration of the negative as a device for semantic enhancement and enrichment of nuance when facing old age and death.

For two decades, solid waste components in Bank projects have focused on collection of solid wastes, with equipment provided to upgrade operations at existing open dumps. Since early 1990, the private sector has become increasingly involved in the collection, disposal, and treatment of solid waste, and Bank projects have placed greater priority on implementation of new sanitary landfills. The following guidance provides an examination of some of the issues which need to be addressed in landfill siting and design.

The purpose of blasting operations is rock fragmentation. Blasting is a key component in the overall rock fragmentation system - the first element of the ore extraction process. It provides appropriate rock material granulation or size that is suitable for loading and transportation. However, in spite of many advantages explosives have, their usage may cause environmental problem such as seismic vibration. One of the solutions to this particular problem may be application of an artificial screen as a barrier to the seismic wave path. The results of experimental research on the artificial screen concept, its characteristics and role in attenuation of seismic effects generated by blasting are presented. The experiment is based on two physical phenomena: (1) the size and degree of discontinuity and (2) the reflection and refraction of seismic waves. More than 1,500 laboratory measurements were conducted with different combinations of screen sizes, positions of the screen to blasting source, and intensities of blasting impulses. The results of the study show reduction of generated vibrations up to 58% by employment of artificial screens.

The aim of this study is to investigate the difference of EEG dynamics on navigation performance. A tunnel task was designed to classify subjects into allocentric or egocentric spatial representation users. Despite of the differences of mental spatial representation, behavioral performance in general were compatible between the two strategies subjects in the tunnel task. Task-related EEG dynamics in power changes

This paper investigates the politeness strategies and mitigation devices used by native and non-native speakers (advanced learners) of Greek when refusing an invitation from an intimate and their consequences for the expression of politeness. Furthermore, it examines whether length of residence or intensity of interaction with native speakers affect non-native speakers’ performance. The data are drawn from role plays performed by native speakers and non-native speakers of two different groups: one with extended length of residence but limited opportunities for social interaction with native speakers and one with less extended length of residence but considerably more frequent opportunities for social interaction. On the basis of these data, it is argued that with regard to the speech act of declining an invitation from a friend, length of residence can be an insufficient measure whereas intensity of interaction can guarantee better results as regards pragmatic appropriateness and politeness. The significant deviations observed between native speakers and non-native speakers with limited opportunities for intimate interaction are attributed to the fact that the latter being economic migrants, who suffer from social seclusion, cannot rely on length of residence alone, in order to acquire sociocultural norms and develop pragmatic ability in the use of speech acts like the one investigated here. This fact combined with the finding that both groups of non-native speakers displayed an underdeveloped pragmatic ability in relation to mitigation devices, such as lexical/phrasal downgraders highlights the need for pedagogical intervention which aims at providing learners with metapragmatic information and meaningful opportunities for interaction that may promote their pragmatic development.

The environment around us is radioactive due to background radiation emitted from the sky, earth’s crust, food, water, and building materials. The human body gets exposed to radiation doses of about 82%, which are out of control; they arise from background radiation sources such as terrestrial, cosmic, and exposure to
internal radiation. The background dose from cosmic radiation depends on the altitude, and regions with high altitude have high radiation doses. Natural radioactivity is present in the earth and is present in the different environment geological formations in the rocks and soils. Gamma  radiation emitted from naturally occurring
radioisotopes, such as 40K and the radionuclides  from the 232Th  and 238U  series and  their decay products which exist as trace levels in all  ground  formations,  represents  the  main  external  source  of  irradiation  to  the  human  body. Their concentrations in rocks, soils, and sands depend on the local geology of each region
in the world. Naturally occurring radioactive materials have terrestrial-origin radionuclides since the creation of the earth. The dose rate of background radiation increases because of the existence of some quarries and
springs in some regions which are called high-level background radiation regions. The type of construction materials used in houses can be affecting the dose rate of background radiations. Study of radioactivity in the
environment is important to monitor the levels of radiation to which human is exposed directly or indirectly.  Recently, several international studies have been done and different values were measured. In this article, a review and literature survey of background radiations such as terrestrial, cosmic, and food radiation was carried out.

The aim of this dissertation is to study how facework, mitigation and impersonality are configured in the discourse of jurists (judges and lawyers) during trials.
To elaborate this work, we base our study in a corpus of eight trials (two for each jurisdiction in the Spanish legal system). This corpus has been transcribed following the transcription system of the group Val.Es.Co. (2003.) Our corpus contains 4 hours, 7 minutes and 9 seconds of recording (49,227 words), and has been analysed adapting Albelda et al.’s (2014) method to the needs of our genre and the four objectives that guide this research.
The first of these objectives was to specify the characteristics of the communicative situation and the formal register in trials. This goal has been one of the key factors used to identify the contextual parameters of the genre, as well as the attributes of the face (Goffman, 1967 [1970]) of judges and lawyers during their professional performance.
The second objective was to study facework, understood as the sum of enhancing, threatening and neutral activities involving face (Tracy, 2011), in trials. The analysis of our data has led to the conclusion that the enhancement of the face is associated mainly to ritual values. However, it is possible to identify a number of cases where face enhancement is related to strategic purposes. Regarding the cases where the face is threatened, we follow the proposal of Archer (2008), which distinguishes between face threat and impoliteness. Thus, in trials we can properly talk about impoliteness when an action involving a potential damage to the face of a participant is also a transgression of what might be expected from the genre, and from the particular communicative situation in which the trial occurs.
In connection with facework, we pursue a third objective related to the study of attenuation, which is one of the discursive manifestations of facework. In our study, we assume that attenuation must be understood as a pragmatic strategy whose aim is not only related to face protection, but also aims to facilitate negotiation and agreement. Our analysis of the functions of attenuation in trials supports this latter idea: the functions found in our corpus range from the speakers’ concern for the face, in its social dimension (as in the cases of self-correction or mediation between the parties) to a rhetorical-argumentative use where the satisfaction of social needs is not that relevant (this happens, for example, when attenuation is used to bring objectivity to the discourse).
Finally, the fourth objective is to undertake a more thorough study of impersonality in trials, since impersonality is one of the resources that most frequently relates to attenuation in court. According to the data, there is a tendency to use impersonality with an attenuating value when the speaker seeks for self-protection or acceptance. In fewer cases, impersonality is employed as an attenuation device in order to prevent a conflict. We found no cases in the corpus where impersonality serves to the function of redress the negative effects of a threat or a conflict.
In conclusion, this study shows that, with regard to the concept of facework and, more specifically, impoliteness, it must be rethought the equation that has been done so far between ‘face threat’ and ‘impoliteness’. In some genres, such as trials, it can be proven that the relationship between these two types of facework is not equivalent. Regarding attenuation, the study of this pragmatic phenomenon from a genre such as trials, being intrinsically transactional and decidedly argumentative, has highlighted the need to understand attenuation as a pragmatic strategy whose motivation is not always taking care of the face, but which can also reflect the desire of convincing others or preventing a conflict. Lastly, with regard to the mechanisms of attenuation, impersonality has emerged as a resource where the de-focalization of one of the participants in the interaction relates primarily to self-protection or care of the own face.

RESUMEN
Esta tesis trata de determinar la manera en que se configuran las actividades de imagen, la atenuación y la impersonalidad en el discurso de los profesionales del derecho (jueces y abogados) durante el transcurso de los juicios orales.
Para la elaboración de este trabajo, partimos de un corpus de ocho juicios orales (dos por cada jurisdicción presente en el ordenamiento jurídico español) que ha sido transcrito siguiendo el sistema de transcripción del grupo Val.Es.Co. (2003). En total, el corpus suma 4 horas, 7 minutos y 9 segundos de grabación y consta de 49227 palabras. El corpus se ha analizado adaptando la ficha metodológica de Albelda et al. (2014) a las necesidades de nuestro género y los cuatro objetivos que guían esta investigación.
El primero de estos objetivos ha sido precisar las características de la situación comunicativa y el registro formal en los juicios orales. Este objetivo ha sido una de las claves para poder identificar los parámetros contextuales y los atributos de la imagen de jueces y abogados durante su ejercicio profesional.
El segundo objetivo se ha centrado en estudiar las actividades de imagen, entendidas en el sentido de Tracy (2011) como aquellas actividades valorizadoras, amenazantes y neutras por lo que respecta a la imagen (Goffman 1967 [1970]), en los juicios orales. En concreto, el análisis de nuestros datos ha permitido concluir que la valorización de la imagen se relaciona, fundamentalmente, con valores rituales. Con todo, es posible identificar casos donde el refuerzo de la imagen desarrolla propiamente fines estratégicos. En lo que se refiere a la amenaza a la imagen, seguimos la propuesta de Archer (2008), que distingue entre amenaza a la imagen y descortesía. Así, en los juicios orales podremos hablar de descortesía cuando una amenaza a la imagen suponga, además de un potencial daño a la imagen de algún participante, una transgresión de lo esperable en el género y la situación comunicativa concreta.
En relación con las actividades de imagen, se planteó un tercer objetivo relacionado con el estudio de una de sus manifestaciones discursivas, la atenuación. Para nuestro estudio partimos de que la atenuación debe ser entendida como una estrategia pragmática destinada no solo a proteger la imagen sino a facilitar la negociación y el acuerdo. La manera en que se concretan las funciones de la atenuación en nuestro corpus refuerzan esta idea, puesto que van desde una preocupación por la imagen en su dimensión más social (como sucede en los casos de autocorrección o mediación entre las partes) hasta usos retórico-argumentativos donde la imagen se sitúa en un segundo plano (esto sucede, por ejemplo, cuando la atenuación se emplea para la creación de un discurso objetivo).
Finalmente, el cuarto objetivo se ha concretado en estudiar uno de los mecanismos que más frecuentemente se asocia a la atenuación, la impersonalidad, en el contexto de los juicios orales. Los datos muestran una tendencia a emplear la impersonalidad con valor atenuante para proteger al propio hablante y que se acepten sus ideas, y en menor medida, para prevenir un conflicto. No encontramos casos en el corpus donde la impersonalidad se relacionara con la función reparación de la amenaza o el conflicto.
A modo de conclusión, este estudio pone de manifiesto que, por lo que respecta a las actividades de imagen y, más concretamente, a la descortesía, es preciso replantearse la equiparación que se ha hecho hasta ahora entre ‘amenaza a la imagen’ y ‘descortesía’, ya que en géneros como los juicios orales se demuestra que la relación entre estas dos actividades de imagen no es equivalente. En lo que se refiere a la atenuación, partir de un género transaccional y marcadamente argumentativo ha evidenciado la necesidad de entender la atenuación como una estrategia pragmática cuya motivación no siempre parte del cuidado de las imágenes, sino que también puede relacionarse con la voluntad de convencer o prevenir un conflicto. Finalmente, por lo que respecta a los mecanismos de atenuación, la impersonalidad se ha revelado como un recurso donde la ocultación del agente se relaciona, fundamentalmente, con la autoprotección o autoimagen.

The Ground Penetrating Radar (GPR) method has been extensively used to map shallow subsurface features. Such kind of information is very important for different types of studies, ranging from archaeological to groundwater search. Almost all GPR surveys for groundwater exploration are usually conducted in sedimentary terrains. In this paper, we demonstrate the applicability of the GPR method in the exploration of underground water in a crystalline terrain. An example of fixed offset data collected at one known spring in the district of Petrópolis (Brazil) is given. Common Mid Point (CMP) data were also collected to estimate the velocity of the radar waves. The saturated region is clearly outlined in the GPR section as a zone of attenuation and inversion of the wavelet phase polarity.

The liner and mass absorption coefficient of various soil samples (density ranges between 1.1308 and 1.3959gcm-3) collected from four sites distributed in Aurangabad region of India have been determined for gamma ray sources 133 Ba, 137 Cs, 22 Na, 60 Co with gamma-ray energy of 0.360MeV, o.662MeV,1.28MeV and 1.33 MeV using gamma spectrometry NaI scintillator/PMT detector and MCA system. Attenuation coefficient is of interest to scientists and research in different areas of present day technology.Samples are prepared using standard techniques and the attenuation constants estimated are presented. It is found that the linear attenuation coefficient is in the range of 1.0520 to 1.0813, 1.0645 to 1.1603, 1.0387 to 1.1504 and 1.0336 to 1.1115 cm-1 for 133 Ba, 137 Cs, 22 Na and 60 Co respectively. Also the mass attenuation coefficient is found in the range of 0.7687 to 0.9562, 0.7632 to 0.9648, 0.8130 to 0.9336 and 0.7794 to 0.9140 cm 2 /gm for 133 Ba, 137 Cs, 22 Na and 60 Co respectively. The work presented is part of a survey recently conducted with larger database. In general, mass attenuation coefficients determined in this study can be used for determination of gamma emitters in any soil samples. This method is useful for the study of properties the soils in agriculture purposes.