2 research outputs found

    Devices and networks for optical switching

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    This thesis is concerned with some aspects of the application of optics to switching and computing. Two areas are dealt with: the design of switching networks which use optical interconnects, and the development and application of the t-SEED optical logic device. The work on optical interconnects looks at the multistage interconnection network which has been proposed as a hybrid switch using both electronics and optics. It is shown that the architecture can be mapped from one dimensional to two dimensional format, so that the machine makes full use of the space available to the optics. Other mapping rules are described which allow the network to make optimum use of the optical interconnects, and the endpoint is a hybrid optical-electronic machine which should be able to outperform an all-electronic equivalent. The development of the t-SEED optical logic device is described, which is the integration of a phototransistor with a multiple quantum well optical modulator. It is found to be important to have the modulator underneath rather than on top of the transistor to avoid unwanted thyristor action. In order for the transistor to have a high gain the collector must have a low doping level, the exit window in the substrate must be etched all the way to the emitter layer, and the etch must not damage the emitter-base junction. A real optical gain of 1.6 has been obtained, which is higher than has ever been reached before but is not as high as should be possible. Improvements to the device are suggested. A new model of the Fabry-Perot cavity is introduced which helps considerably in the interpretation of experimental measurements made on the quantum well modulators. Also a method of improving the contrast of the multiple quantum well modulator by grading the well widths is proposed which may find application in long wavelength transmission modulators. Some systems which make use of the t-SEED are considered. It is shown that the t-SEED device has the right characteristics for use as a neuron element in the optical implementation of a neural network. A new image processing network for clutter removal in binary images is introduced which uses the t-SEED, and a brief performance analysis suggests that the network may be superior to an all-electronic machine

    ASYMMETRY INFORMATION: INVESTORS TRUST REFLECTION TOWARD QUALITY OF EARNINGS

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    This article aims to describe the investors' trust toward quality of earnings reflection proxied by earnings response coeffisient (ERC). The study was conducted on 296 manufacturing companies that meet the criteria of observations in 2011 to 2015. The variables used in this research is the board of directors, audit comitee, the independent board as exogenous variables, information asymmetry as an intervening variable and earnings response coeffisient (ERC) as an endogenous variable by means of persistency as control variables. The board of directors and the independent board in this article as a proxy of corporate governance show the effect on the information gap represented by information asymmetry, while the audit comitee Showed the opposite effect. Information gaps provide explanatory power on the reflection of investor confidence in the quality of earnings that are Reported company
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