332 resultados para ‘I’ boundaries
Resumo:
CFO and I/Q mismatch could cause significant performance degradation to OFDM systems. Their estimation and compensation are generally difficult as they are entangled in the received signal. In this paper, we propose some low-complexity estimation and compensation schemes in the receiver, which are robust to various CFO and I/Q mismatch values although the performance is slightly degraded for very small CFO. These schemes consist of three steps: forming a cosine estimator free of I/Q mismatch interference, estimating I/Q mismatch using the estimated cosine value, and forming a sine estimator using samples after I/Q mismatch compensation. These estimators are based on the perception that an estimate of cosine serves much better as the basis for I/Q mismatch estimation than the estimate of CFO derived from the cosine function. Simulation results show that the proposed schemes can improve system performance significantly, and they are robust to CFO and I/Q mismatch.
Resumo:
Sleeper is an 18'00" musical work for live performer and laptop computer which exists as both a live performance work and a recorded work for audio CD. The work has been presented at a range of international performance events and survey exhibitions. These include the 2003 International Computer Music Conference (Singapore) where it was selected for CD publication, Variable Resistance (San Francisco Museum of Modern Art, USA), and i.audio, a survey of experimental sound at the Performance Space, Sydney. The source sound materials are drawn from field recordings made in acoustically resonant spaces in the Australian urban environment, amplified and acoustic instruments, radio signals, and sound synthesis procedures. The processing techniques blur the boundaries between, and exploit, the perceptual ambiguities of de-contextualised and processed sound. The work thus challenges the arbitrary distinctions between sound, noise and music and attempts to reveal the inherent musicality in so-called non-musical materials via digitally re-processed location audio. Thematically the work investigates Paul Virilio’s theory that technology ‘collapses space’ via the relationship of technology to speed. Technically this is explored through the design of a music composition process that draws upon spatially and temporally dispersed sound materials treated using digital audio processing technologies. One of the contributions to knowledge in this work is a demonstration of how disparate materials may be employed within a compositional process to produce music through the establishment of musically meaningful morphological, spectral and pitch relationships. This is achieved through the design of novel digital audio processing networks and a software performance interface. The work explores, tests and extends the music perception theories of ‘reduced listening’ (Schaeffer, 1967) and ‘surrogacy’ (Smalley, 1997), by demonstrating how, through specific audio processing techniques, sounds may shifted away from ‘causal’ listening contexts towards abstract aesthetic listening contexts. In doing so, it demonstrates how various time and frequency domain processing techniques may be used to achieve this shift.
Resumo:
There is much still to learn about how young children’s membership with peers shapes their constructions of moral and social obligations within everyday activities in the school playground. This paper investigates how a small group of girls, aged four to six years, account for their everyday social interactions in the playground. They were video-recorded as they participated in a pretend game of school. Several days later, a video-recorded excerpt of the interaction was shown to them and invited to comment on what was happening in the video. This conversation was audio-recorded. Drawing on a conversation analysis approach, this chapter shows that, despite their discontent and complaining about playing the game of school, the girls’ actions showed their continued orientation to the particular codes of the game, of ‘no going away’ and ‘no telling’. By making relevant these codes, jointly constructed by the girls during the interview, they managed each other’s continued participation within two arenas of action: the pretend, as a player in a pretend game of school; and the real, as a classroom member of a peer group. Through inferences to explicit and implicit codes of conduct, moral obligations were invoked as the girls attempted to socially exclude or build alliances with others, and enforce their own social position. As well, a shared history that the girls re-constructed has moral implications for present and future relationships. The girls oriented to the history as an interactional resource for accounting for their actions in the pretend game. This paper uncovers how children both participate in, and shape, their everyday social worlds through talk and interaction and the consequences a taken-for-granted activity such as playing school has for their moral and social positions in the peer group.
Resumo:
Key topics: Since the birth of the Open Source movement in the mid-80's, open source software has become more and more widespread. Amongst others, the Linux operating system, the Apache web server and the Firefox internet explorer have taken substantial market shares to their proprietary competitors. Open source software is governed by particular types of licenses. As proprietary licenses only allow the software's use in exchange for a fee, open source licenses grant users more rights like the free use, free copy, free modification and free distribution of the software, as well as free access to the source code. This new phenomenon has raised many managerial questions: organizational issues related to the system of governance that underlie such open source communities (Raymond, 1999a; Lerner and Tirole, 2002; Lee and Cole 2003; Mockus et al. 2000; Tuomi, 2000; Demil and Lecocq, 2006; O'Mahony and Ferraro, 2007;Fleming and Waguespack, 2007), collaborative innovation issues (Von Hippel, 2003; Von Krogh et al., 2003; Von Hippel and Von Krogh, 2003; Dahlander, 2005; Osterloh, 2007; David, 2008), issues related to the nature as well as the motivations of developers (Lerner and Tirole, 2002; Hertel, 2003; Dahlander and McKelvey, 2005; Jeppesen and Frederiksen, 2006), public policy and innovation issues (Jullien and Zimmermann, 2005; Lee, 2006), technological competitions issues related to standard battles between proprietary and open source software (Bonaccorsi and Rossi, 2003; Bonaccorsi et al. 2004, Economides and Katsamakas, 2005; Chen, 2007), intellectual property rights and licensing issues (Laat 2005; Lerner and Tirole, 2005; Gambardella, 2006; Determann et al., 2007). A major unresolved issue concerns open source business models and revenue capture, given that open source licenses imply no fee for users. On this topic, articles show that a commercial activity based on open source software is possible, as they describe different possible ways of doing business around open source (Raymond, 1999; Dahlander, 2004; Daffara, 2007; Bonaccorsi and Merito, 2007). These studies usually look at open source-based companies. Open source-based companies encompass a wide range of firms with different categories of activities: providers of packaged open source solutions, IT Services&Software Engineering firms and open source software publishers. However, business models implications are different for each of these categories: providers of packaged solutions and IT Services&Software Engineering firms' activities are based on software developed outside their boundaries, whereas commercial software publishers sponsor the development of the open source software. This paper focuses on open source software publishers' business models as this issue is even more crucial for this category of firms which take the risk of investing in the development of the software. Literature at last identifies and depicts only two generic types of business models for open source software publishers: the business models of ''bundling'' (Pal and Madanmohan, 2002; Dahlander 2004) and the dual licensing business models (Välimäki, 2003; Comino and Manenti, 2007). Nevertheless, these business models are not applicable in all circumstances. Methodology: The objectives of this paper are: (1) to explore in which contexts the two generic business models described in literature can be implemented successfully and (2) to depict an additional business model for open source software publishers which can be used in a different context. To do so, this paper draws upon an explorative case study of IdealX, a French open source security software publisher. This case study consists in a series of 3 interviews conducted between February 2005 and April 2006 with the co-founder and the business manager. It aims at depicting the process of IdealX's search for the appropriate business model between its creation in 2000 and 2006. This software publisher has tried both generic types of open source software publishers' business models before designing its own. Consequently, through IdealX's trials and errors, I investigate the conditions under which such generic business models can be effective. Moreover, this study describes the business model finally designed and adopted by IdealX: an additional open source software publisher's business model based on the principle of ''mutualisation'', which is applicable in a different context. Results and implications: Finally, this article contributes to ongoing empirical work within entrepreneurship and strategic management on open source software publishers' business models: it provides the characteristics of three generic business models (the business model of bundling, the dual licensing business model and the business model of mutualisation) as well as conditions under which they can be successfully implemented (regarding the type of product developed and the competencies of the firm). This paper also goes further into the traditional concept of business model used by scholars in the open source related literature. In this article, a business model is not only considered as a way of generating incomes (''revenue model'' (Amit and Zott, 2001)), but rather as the necessary conjunction of value creation and value capture, according to the recent literature about business models (Amit and Zott, 2001; Chresbrough and Rosenblum, 2002; Teece, 2007). Consequently, this paper analyses the business models from these two components' point of view.
Resumo:
This paper aims to develop the methodology and strategy for concurrent finite element modeling of civil infrastructures at the different scale levels for the purposes of analyses of structural deteriorating. The modeling strategy and method were investigated to develop the concurrent multi-scale model of structural behavior (CMSM-of-SB) in which the global structural behavior and nonlinear damage features of local details in a large complicated structure could be concurrently analyzed in order to meet the needs of structural-state evaluation as well as structural deteriorating. In the proposed method, the “large-scale” modeling is adopted for the global structure with linear responses between stress and strain and the “small-scale” modeling is available for nonlinear damage analyses of the local welded details. A longitudinal truss in steel bridge decks was selected as a case to study how a CMSM-of-SB was developed. The reduced-scale specimen of the longitudinal truss was studied in the laboratory to measure its dynamic and static behavior in global truss and local welded details, while the multi-scale models using constraint equations and substructuring were developed for numerical simulation. The comparison of dynamic and static response between the calculated results by different models indicated that the proposed multi-scale model was found to be the most efficient and accurate. The verification of the model with results from the tested truss under the specific loading showed that, responses at the material scale in the vicinity of local details as well as structural global behaviors could be obtained and fit well with the measured results. The proposed concurrent multi-scale modeling strategy and implementation procedures were applied to Runyang cable-stayed bridge (RYCB) and the CMSM-of-SB of the bridge deck system was accordingly constructed as a practical application.
Resumo:
The measurement of Cobb angles on radiographs of patients with spinal deformities is routine practice in spinal clinics. The technique relies on the use and availability of specialist equipment such as a goniometer, cobbometer or protractor. The aim of this study was to validate the use of i-Phone (Apple Inc) combined with Tilt Meter Pro software as compared to a protractor in the measurement of Cobb angles. The i-Phone combined with Tilt Meter Pro software offers a faster alternative to the traditional method of Cobb angle measurement. The use of i-Phone offers a more convenient way of measuring Cobb angles in the outpatient setting. The intra-observer repeatability of the iPhone is equivalent to the protractor in the measurement of Cobb angles.
Resumo:
Secondary social education in Australia is set to change with the new national history curriculum but integrated social education will continue in the middle years of schooling. Competing discourses of disciplinary and integrated social education approaches create new challenges for pre-service teachers as identification with a teaching area is an important aspect of developing a broader teacher identity. Feedback on a compulsory, final year curriculum studies unit revealed the majority of secondary pre-service teachers identified with at least one social science discipline. However, only a small number listed the integrated social education curriculum of Studies of Society and Environment (SOSE), even though SOSE was an essential part of their brief. More complex identities were revealed in post-teaching practice interviews. In times of curriculum change, attention to pre-service teachers’ disciplinary knowledge is critical in developing a stable subject identity.
Resumo:
After many years of development BIM (Building Information Modelling) is starting to achieve significant penetration into the building sector of the construction industry. This paper describes the current status of BIM and the drivers that are motivating the change from 2D CAD to BIM within the building sector. The paper then discusses what the implications of the technology underlying BIM may be for the civil construction sector of the construction industry. A project carried out by the Cooperative Research Centre for Construction Innovation is used as an example of this technology as well as several international examples.
Resumo:
Agent-oriented conceptual modelling (AoCM) approaches in Requirements Engineering (RE) have received considerable attention recently. Semi-formal modeling frameworks such as i* assist analysts in requirements elicitation and reasoning of early-phase RE. AgentSpeak(L) is a widely accepted agent programming language. The Strategic Rationale (SR) model of the i* framework naturally lends itself to AgentSpeak(L) programs. Furthermore, the Strategic Dependency (SD) component of the i* framework prescribes the interaction between the agents in a multi-agent environment. This paper proposes a formal methodology for transforming a SR model to an AgentS- peak(L) agent. The constructed AgentSpeak(L) agents will then form the essential components of a multi-agent system, MAS.
Resumo:
The theme of this conference comes from the epitaph on the Lewis Carroll’s gravesite. “Is All our Life then But A Dream?” This seems fitting for a time when so much change in the terrain of English makes us feel as if we are somnambulating through a surrealist landscape. Like Lewis Carroll’s Alice, (Carroll, 2003) we might find ourselves at strange tea parties with bureaucratic mad hatters, and just when we think we have a grasp of applying new theory in our teaching, we fall down another rabbit hole, to swim in confusion as some queen calls out, ‘off with their heads!’. The shifting ground in English inevitably moves in response to waves of theory influencing classroom practice. Each new paradigm has claimed to liberate language learners from the flaws of the previous model. Each linguist or literary theorist who shaped the new paradigm no doubt dreamt of a new population emerging from school as more powerfully literate citizens than the previous generation.
Resumo:
In recent years concern has been expressed internationally about the future of the library and information services (LIS) profession: recruitment and retention, changing skill sets and declining numbers of people choosing librarianship as a career are all factors contributing to an uncertain future. One area yet explored in any depth is the topic of why LIS studies are not perceived, let alone promoted, as a good first professional qualification for high school graduates. This paper considers the professional literature that examines the uptake of librarianship as a first qualification by school leavers and discusses, in the context of the Australian library sector, the role of professional associations, library schools, National and State Libraries, as well as individual libraries and librarians. Examples of best practice are presented to highlight the opportunities for inspiring and motivating students through well structured and stimulating work experience programs. The topic is relevant to all librarians who are interested in the future of the LIS profession. It is argued that the focus of the present conference on ‘moving up’ and ‘moving on’ can only have real significance when the profession has a more complete understanding of the barriers to and the opportunities for ‘moving in’.
Resumo:
There is little evidence, historical or otherwise, to suggest that the needs of people and societies change greatly over time. Whilst acknowledging the benefits of the many recent technological innovations that are part of the contemporary milieu, I am reluctant to see such advances as sufficient rationale for the dismantling of the social contract between a government and its citizenry. The Multilateral Agreement on Investment (MAI) highlights the move amongst developed countries to replace a national policy focus with a multilateral approach to global policy formulation that transcends the sovereignty of nation states. The purpose of this paper is to refute the assumptions underpinning multilateralist assertions that government has a diminishing role to play in the global society, and that national sovereignty, due to the increasingly important role of multilateral agreements and the global economy, is ‘a thing of the past’ (Arthur Asher, background briefing interview, Radio National, February 1, 1998). The basic premises that underpin the globalist argument1 for the diminishing role of government are that: • Economic growth increases jobs, prosperity, and freedom. • Free trade is an imperative for successful globalisation because financial sector performance - which depends on deregulation - is integral to global economic growth. • Information technology is revolutionising global trade and making globalisation inevitable. • Globalisation through deregulation, makes national boundaries meaningless, and therefore, national regulatory policies anachronistic. This paper compares the aforementioned axiomatic premises of globalisation to actual outcomes, events, and trends in the real world.
Resumo:
It has often been argued that young woman’s magazine’s, like Cosmopolitan, Cleo Dolly and Seventeen, constitute a significant instrument in the patriarchal repression of young women - their hegemonic success lying in the fact that they appear to be sites wherein young women are ‘free’ from the elements of coercion so obviously in evidence within other terrains, such as the school and the family. This paper will suggest an alternative approach to these magazines. Rather than locating such texts within an overall model of repression and patriarchal domination, it will be argued here that they can be regarded as practical manuals which enrol young women to do specific kinds of work on themselves. In doing so, they form an effective link between the governmental imperatives aimed at constructing particular personas (such as, for example, ‘the sexually responsible young woman’), and the actual practices whereby these imperatives are operationalised. These manuals do not prevent young women from learning to ‘project a unique self’, they constitute a significant source of practices and techniques through which particular types of self are shaped.