A novel all-fiber bipolar transversal filter with complementary outputs

A novel all-fiber bipolar delay line filter is realized in a single-line cascaded high birefringence fiber structure. Optically coherent operation is achieved with suppression of interference noise. Complementary filter outputs give simultaneous lowpass and highpass responses.

A novel all fiber microwave transversal filter with complementary outputs

A novel all-fiber bipolar delay line filter is realized in a single-line cascaded high birefringence fiber structure. Optically coherent operation is achieved with suppression of interference noise. Complementary filter outputs give simultaneous lowpass and highpass responses.

A novel dual complementary output optical fiber transversal filter for DWDM applications

A novel dual complementary output optical fiber transversal filter is realized for DWDM applications. Stable, simultaneous complementary filter responses with flattened passbands and large sidelobe suppressions are achieved with a single-line cascaded Hi-Bi fiber structure.

Bayesian regression filter and the issue of priors

We propose a Bayesian framework for regression problems, which covers areas which are usually dealt with by function approximation. An online learning algorithm is derived which solves regression problems with a Kalman filter. Its solution always improves with increasing model complexity, without the risk of over-fitting. In the infinite dimension limit it approaches the true Bayesian posterior. The issues of prior selection and over-fitting are also discussed, showing that some of the commonly held beliefs are misleading. The practical implementation is summarised. Simulations using 13 popular publicly available data sets are used to demonstrate the method and highlight important issues concerning the choice of priors.

Use of complementary and alternative medicine and self-tests by coronary heart disease patients

Background: Coronary heart disease patients have to learn to manage their condition to maximise quality of life and prevent recurrence or deterioration. They may develop their own informal methods of self-management in addition to the advice they receive as part of formal cardiac rehabilitation programmes. This study aimed to explore the use of complementary and alternative medicines and therapies (CAM), self-test kits and attitudes towards health of UK patients one year after referral to cardiac rehabilitation. Method: Questionnaire given to 463 patients attending an assessment clinic for 12 month follow up in four West Midlands hospitals. Results: 91.1% completed a questionnaire. 29.1% of patients used CAM and/or self-test kits for self-management but few (8.9%) used both methods. CAM was more often used for treating other illnesses than for CHD management. Self-test kit use (77.2%,) was more common than CAM (31.7%,) with BP monitors being the most prevalent (80.0%). Patients obtained self-test kits from a wide range of sources, for the most part (89.5%) purchased entirely on their own initiative. Predictors of self-management were post revascularisation status and higher scores on 'holism', 'rejection of authority' and 'individual responsibility'. Predictors of self-test kit use were higher `holism' and 'individual responsibility' scores. Conclusion: Patients are independently using new technologies to monitor their cardiovascular health, a role formerly carried out only by healthcare practitioners. Post-rehabilitation patients reported using CAM for self-management less frequently than they reported using self-test kits. Reports of CAM use were less frequent than in previous surveys of similar patient groups. Automatic assumptions cannot be made by clinicians about which CHD patients are most likely to self-manage. In order to increase trust and compliance it is important for doctors to encourage all CHD patients to disclose their self-management practices and to continue to address this in follow up consultations.

Apodisation of photo-induced waveguide gratings using double-exposure with complementary duty cycles

We present a novel apodisation scheme for photo-induced waveguide gratings. The apodisation is implemented with double exposures that have reversely varying duty cycles. We have successfully applied the proposed scheme to remove the sidelobes of long period gratings (LPGs). We also observed for the first time super strong sidelobes in LPGs when creating them with only a single varying-duty-cycle exposure. The strong sidelobes can be well explained with a Mach-Zehnder interference model.

Simultaneous interrogation of fiber Bragg grating sensors using an acoustooptic tunable filter

We describe a novel technique to provide demultiplexing of fiber Bragg grating sensors, interrogated using interferometric wavelength shift detection. Amplitude modulation of multiple radio frequency driving signals allows an acoustooptic tunable filter to provide wavelength demultiplexing. We demonstrated a noise limited strain resolution of 150 nanostrain/v(Hz) and a crosstalk better than -50 dB.

Fast and widely tunable Bragg grating reflection filter

A fiber Bragg grating filter device linearly tunable over 45 nm is presented. The device has a maximum tuning speed of 19 nm/ms with a wavelength setting time below 1.5 ms.

On the adoption decision and the intensity of use of complementary innovations: The intra firm diffusion of management practices across UK establishments

This paper contributes to the literature on the intra-firm diffusion of innovations by investigating the factors that affect the firm’s decision to adopt and use sets of complementary innovations. We define complementary innovations those innovations whose joint use generates super additive gains, i.e. the gain from the joint adoption is higher than the sum of the gains derived from the adoption of each innovation in isolation. From a theoretical perspective, we present a simple decision model, whereby the firm decides ‘whether’ and ‘how much’ to invest in each of the innovations under investigation based upon the expected profit gain from each possible combination of adoption and use. The model shows how the extent of complementarity among the innovations can affect the firm’s profit gains and therefore the likelihood that the firm will adopt these innovations jointly, rather than individually. From an empirical perspective, we focus on four sets of management practices, namely operating (OMP), monitoring (MMP), targets (TMP) and incentives (IMP) management practices. We show that these sets of practices, although to a different extent, are complementary to each other. Then, we construct a synthetic indicator of the depth of their use. The resulting intra-firm index is built to reflect not only the number of practices adopted but also the depth of their individual use and the extent of their complementarity. The empirical testing of the decision model is carried out using the evidence from the adoption behaviour of a sample of 1,238 UK establishments present in the 2004 Workplace Employment Relations Survey (WERS). Our empirical results show that the intra-firm profitability based model is a good model in that it can explain more of the variability of joint adoption than models based upon the variability of adoption and use of individual practices. We also investigate whether a number of firm specific and market characteristics by affecting the size of the gains (which the joint adoption of innovations can generate) may drive the intensity of use of the four innovations. We find that establishment size, whether foreign owned, whether exposed to an international market and the degree of homogeneity of the final product are important determinants of the intensity of the joint adoption of the four innovations. Most importantly, our results point out that the factors that the economics of innovation literature has been showing to affect the intensity of use of a technological innovation do also affect the intensity of use of sets of innovative management practices. However, they can explain only a small part of the diversity of their joint adoption use by the firms in the sample.

Portfolio diversification and filter rule profits

Previously, it has been shown that the profits from a simple market timing trading rule applied to a portfolio of shares can be affected by the inter-relationships between the returns of the component securities. In this short letter, the results from applying a more sophisticated 'filter' rule to the same data are reported. Unlike the simple trading rule, the filter rule does produce some evidence of economic profits.

The intra-firm diffusion of complementary innovations: Evidence from the adoption of management practices by British establishments

This paper presents a simple profitability-based decision model to show how synergistic gains generated by the joint adoption of complementary innovations may influence the firm's adoption decision. For this purpose a weighted index of intra-firm diffusion is built to investigate empirically the drivers of the intensity of joint use of a set of complementary innovations. The findings indicate that establishment size, ownership structure and product market concentration are important determinants of the intensity of use. Interestingly, the factors that affect the extent of use of technological innovations do also affect that of clusters of management practices. However, they can explain only part of the heterogeneity of the benefits from joint use.