995 research outputs found

    Issues in stress and burnout for women in management and non-management positions

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    vii, 69, [24] leaves ; 28 cm.Includes bibliographical references (leaves [70-83]).The primary purpose of this study was to examine from an ecological perspective how the factors of work environment, stress and psychological sense of community impacted on the experience of burnout for women in management and non-management positions within a large organization. The results indicated that the experience of burnout is different depending on the level of the organization in that non-management personnel experienced the highest burnout. Environmental variables were found to significantly contribute to the experience of burnout and their specific impact also varied with the respondents place in the organizational hierarchy. Psychological sense of community was found to be significantly and negatively related to burnout. Implications for current burnout conceptualization, women in the work force, the organization and pertinent treatment issues via primary and secondary prevention are discussed. (Abstract shortened by UMI.

    Phase estimation receiver for full-field detection: a novel receiver structure for electronic dispersion compensation of metropolitan area networks

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    The development of ultra high speed (~20 Gsamples/s) analogue to digital converters (ADCs), and the delayed deployment of 40 Gbit/s transmission due to the economic downturn, has stimulated the investigation of digital signal processing (DSP) techniques for compensation of optical transmission impairments. In the future, DSP will offer an entire suite of tools to compensate for optical impairments and facilitate the use of advanced modulation formats. Chromatic dispersion is a very significant impairment for high speed optical transmission. This thesis investigates a novel electronic method of dispersion compensation which allows for cost-effective accurate detection of the amplitude and phase of the optical field into the radio frequency domain. The first electronic dispersion compensation (EDC) schemes accessed only the amplitude information using square law detection and achieved an increase in transmission distances. This thesis presents a method by using a frequency sensitive filter to estimate the phase of the received optical field and, in conjunction with the amplitude information, the entire field can be digitised using ADCs. This allows DSP technologies to take the next step in optical communications without requiring complex coherent detection. This is of particular of interest in metropolitan area networks. The full-field receiver investigated requires only an additional asymmetrical Mach-Zehnder interferometer and balanced photodiode to achieve a 50% increase in EDC reach compared to amplitude only detection

    Chromatic dispersion compensation using full-field maximum-likelihood sequence estimation

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    We investigate full-field detection-based maximum-likelihood sequence estimation (MLSE) for chromatic dispersion compensation in 10 Gbit/s OOK optical communication systems. Important design criteria are identified to optimize the system performance. It is confirmed that approximately 50% improvement in transmission reach can be achieved compared to conventional direct-detection MLSE at both 4 and 16 states. It is also shown that full-field MLSE is more robust to the noise and the associated noise amplifications in full-field reconstruction, and consequently exhibits better tolerance to nonoptimized system parameters than full-field feedforward equalizer. Experiments over 124 km spans of field-installed single-mode fiber without optical dispersion compensation using full-field MLSE verify the theoretically predicted performance benefits

    Nonlinearity compensation using optical phase conjugation deployed in discretely amplified transmission systems

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    We introduce a closed form equation, validated by simulations and experimental results, that predicts the residual nonlinear noise ratio in mid-link OPC assisted discretely amplified systems. The model anticipates the reduction in performance enhancement achieved by mid-link OPC as the bandwidth of the modulated signals increases. The numerical analysis shows that uncompensated signal-signal interactions limit the performance improvement achieved by the introduction of additional OPCs. The numerical analysis predicts that the deployment of shorter amplifier spacing will lead to a greater performance enhancement. The numerical results are validated by experimentally testing of 2x, 4x, and 8x28Gbaud PM-QPSK systems with mid-link OPC compensation in a discretely amplified system with 100km amplifier spacing. The experimentally obtained reach enhancement (43%, 32%, and 24% for 2x28Gbaud, 4x28Gbaud, and 8x28Gbaud, respectively) confirms that the compensation efficiency of mid-link OPC is highly dependent on the number of channels (bandwidth) propagating along the system
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