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Particular Point (particular + point)
Selected AbstractsWireless signal-preamble assisted Mach,Zehnder modulator bias stabilisation in wireless signal transmission over optical fibreEUROPEAN TRANSACTIONS ON TELECOMMUNICATIONS, Issue 6 2008Debashis Chanda Lithium niobate based Mach,Zehnder electro-optic modulators are increasingly being used in high-speed digital as well as analog optical links. Depending on the application, digital or analog, the bias point of such a modulator is held constant at a particular point on the sinusoidal electrical to optical power transfer characteristics of the modulator. Bias point drift is one of the major limitations of lithium niobate based Mach,Zehnder electro-optic modulators. This increases the bit error rate of the system and affects adjacent channel performances. In one of the most popular methods of bias control, a pilot tone is used to track the bias point drift. However, pilot tone based bias tracking reduces overall intermodulation free dynamic range of the link. In this paper we propose a method where Mach,Zehnder modulator bias drift is tracked and maintained at the desired point by tracking the power variation of the preamble of wireless signal data frames. The method has no detrimental effects on system performances as no external signal is exclusively injected into the system for bias tracking purposes. Copyright © 2007 John Wiley & Sons, Ltd. [source] Clusters, Power and Place: Inequality and Local Growth in Time,SpaceGEOGRAFISKA ANNALER SERIES B: HUMAN GEOGRAPHY, Issue 2 2002Harald Bathelt The argument of this paper is that a deeper appreciation of the nature of the power relationships between firms and the circuits of power that bind them together is key to understanding how clusters function , including how they might emerge and how they might decline. We begin to develop a conceptualization that allows us to generate a deeper understanding of the processes that enable the production and reproduction of enterprise clusters under some combinations of circumstances but not others. The sections of the paper explore: (1) concepts of power and circuits of power including their spatialities; (2) the temporarily stabilized relationships which occur in clusters of economic activity; (3) the openness and permeability of clusters as a way of understanding conditions that foster cluster growth; (4) a tentative integration of concepts. From this reading of the concepts of clustering and power we draw the conclusion that clusters are, at any particular point in time, temporary and transient conjunctures of interfirm relationships. They depend on specific circumstances in ,time,space' and, because of their very transience and specificity, those conditions might be very difficult if not impossible to create through the blunt instruments of policy. [source] Serum bilirubin levels and mortality after myeloablative allogeneic hematopoietic cell transplantation,HEPATOLOGY, Issue 2 2005Ted A. Gooley Many patients who undergo hematopoietic cell transplantation experience liver injury. We examined the association of serum bilirubin levels with nonrelapse mortality by day +200, testing the hypothesis that the duration of jaundice up to a given point in time provides more prognostic information than either the maximum bilirubin value or the value at that point in time. We studied 1,419 consecutive patients transplanted from allogeneic donors. Total serum bilirubin values up to day +100, death, or relapse were retrieved,along with nonrelapse mortality by day +200 as an outcome measure,using Cox regression models with each bilirubin measure modeled as a time-dependent covariate. The bilirubin value at a particular point in time provided the best fit to the model for mortality. With bilirubin at a point in time modeled as an 8th-degree polynomial, an increase in bilirubin from 1 to 3 mg/dL is associated with a mortality hazard ratio of 6.42. An increase from 4 to 6 mg/dL yields a hazard ratio of 2.05, and an increase from 10 to 12 mg/dL yields a hazard ratio of 1.17. Among patients who were deeply jaundiced, survival was related to the absence of multiorgan failure and to higher platelet counts. In conclusion, the value of total serum bilirubin at a particular point in time after transplant carries more informative prognostic information than does the maximum or average value up to that point in time. The increase in mortality for a given increase in bilirubin value is larger when the starting value is lower. (HEPATOLOGY 2005,41:345,352.) [source] Revisiting the Emergence of the Modern Business Enterprise: Entrepreneurship and the Singer Global Distribution SystemJOURNAL OF MANAGEMENT STUDIES, Issue 7 2007Mark Casson abstract This paper approaches the question of why entrepreneurial firms exist from a broad business historical perspective. It observes that the original development of the modern business enterprise was very strongly associated with entrepreneurial innovation rather than an extension of managerial routine. The widely-used theory of the entrepreneur as a specialist in judgmental decision making is applied to the particular point in time when entrepreneurs had to develop novel organizational designs in what Chandler described as the prelude to the ,managerial revolution'. The paper illustrates how the theory of entrepreneurship then best explains the rise of the modern corporation by focusing on the case study of vertical integration par excellence, Singer. [source] Weak solutions of a phase-field model for phase change of an alloy with thermal propertiesMATHEMATICAL METHODS IN THE APPLIED SCIENCES, Issue 14 2002José Luiz Boldrini The phase-field method provides a mathematical description for free-boundary problems associated to physical processes with phase transitions. It postulates the existence of a function, called the phase-field, whose value identifies the phase at a particular point in space and time. The method is particularly suitable for cases with complex growth structures occurring during phase transitions. The mathematical model studied in this work describes the solidification process occurring in a binary alloy with temperature-dependent properties. It is based on a highly non-linear degenerate parabolic system of partial differential equations with three independent variables: phase-field, solute concentration and temperature. Existence of weak solutions for this system is obtained via the introduction of a regularized problem, followed by the derivation of suitable estimates and the application of compactness arguments. Copyright © 2002 John Wiley & Sons, Ltd. [source] Coresidential Patterns in Historical China: A Simulation StudyPOPULATION AND DEVELOPMENT REVIEW, Issue 2 2000Zhongwei Zhao The controversy regarding China's historical residential patterns is related to the lack of investigation into demographic influences on past kinship structures and household formation. This study uses computer micro-simulation to examine demographic feasibility of people living in large multi-generation households under the demographic conditions close to those recorded in Chinese history. It investigates both the composition of households in which individuals live at a particular point in their life course and the transition in their household structure and the length of time they spend in households of different types. The simulation exercise suggests that demographic regimes and household formation systems similar to those operating in China in the past produce diverse residential patterns, in which individuals could experience different household forms at different stages of the life cycle. [source] Use of film for community conservation education in primate habitat countriesAMERICAN JOURNAL OF PRIMATOLOGY, Issue 5 2010Juliet H. Wright Abstract Wildlife films have become an integral part of broadcast schedules in developed countries. As charismatic mammals, primates are frequently the focus of the wildlife filmmaker's attention. Yet the people watching these films tend to be situated on different continents from the species concerned. Communities in primate habitat countries are unlikely to ever have the opportunity to gain such an insight into the species with which they share their environment and the threats these species face. Over recent years, an increasing number of filmmakers are realizing the importance of reaching local audiences through film for conservation purposes. Published research on the impact films can have on eliciting conservation action in developed or developing countries is minimal. The perceived power of wildlife films to change attitudes and behaviors is largely based on anecdotal evidence. This commentary highlights the on-going debate regarding the conservation impact of wildlife films, discusses the work of various NGOs that are using films for conservation purposes in habitat countries and makes recommendations with regards to the film type and situational context necessary to promote positive conservation behavior in communities. Bespoke conservation films convey a specific message to a specific audience at a particular point in time. If produced by trained local conservation educators, these films are likely to have the biggest impact. Films must be shown as a part of a conservation education program that incorporates other education materials and group discussion so that the desired conservation message can be clearly defined and reinforced. Audiences should not be made to feel disillusioned, depressed or vilified by the content of wildlife films. Rather films should increase support for conservation and empower people to act. Once enthusiasm for specific conservation actions has been created, practical assistance and follow-up support is necessary to ensure ideas are implemented. Am. J. Primatol. 72:462,466, 2010. © 2009 Wiley-Liss, Inc. [source] Involving people with learning disabilities in research: issues and possibilitiesHEALTH & SOCIAL CARE IN THE COMMUNITY, Issue 4 2004Tony Gilbert Abstract Advances in the social position of people with learning disabilities have led to a situation where research and evaluation studies are increasingly required to include the views and opinions of people with learning disabilities. One key outcome of this shift is that some of the major funding bodies now insist on the inclusion of people with learning disabilities as a condition of research funding. This has produced new possibilities and new challenges for researchers, and it has real consequences for people working in health and social care. The present paper sets out to explore some of the developments and challenges in research with people with learning disabilities. The author provides a selective overview of developments with the aim of demonstrating the richness, ingenuity and potential of research involving people with learning disabilities. The paper is divided into three broad sections that focus on: (1) the ethics and philosophy of participatory research; (2) the methodologies employed at particular points in the research process that are designed to ensure the involvement of participants in research; and (3) building capacity in participatory research as a precondition to the further development of this approach. An investment in capacity would enable this approach to move into the mainstream of research activity involving people with learning disabilities. [source] | |||||||||||||