Low-complexity BCH codes with optimized interleavers for DQPSK systems with laser phase noise

The presence of high phase noise in addition to additive white Gaussian noise in coherent optical systems affects the performance of forward error correction (FEC) schemes. In this paper, we propose a simple scheme for such systems, using block interleavers and binary Bose–Chaudhuri–Hocquenghem (BCH) codes. The block interleavers are specifically optimized for differential quadrature phase shift keying modulation. We propose a method for selecting BCH codes that, together with the interleavers, achieve a target post-FEC bit error rate (BER). This combination of interleavers and BCH codes has very low implementation complexity. In addition, our approach is straightforward, requiring only short pre-FEC simulations to parameterize a model, based on which we select codes analytically. We aim to correct a pre-FEC BER of around (Formula presented.). We evaluate the accuracy of our approach using numerical simulations. For a target post-FEC BER of (Formula presented.), codes selected using our method result in BERs around 3(Formula presented.) target and achieve the target with around 0.2 dB extra signal-to-noise ratio.

Multiplier-free blind phase noise estimation for CO-OFDM transmission

We experimentally demonstrate an effective multiplier-free blind phase noise estimation technique for CO-OFDM systems for the first time based on the statistical properties of the received symbols' phases. Our technique operates in polar coordinates, providing very low implementation complexity.

Institutional complexity in Thai state-owned enterprises:the implementation of performance measurement systems

This study explores institutional complexity in Thai State-Owned Enterprises (SOEs). In doing so, a qualitative approach has been employed in this study in order to identify institutional logics in the field of Thai SOEs and to understand organisational and individual perceptions of institutional complexity in the implementation of performance measurement systems (PMS) and how they respond to the complexity. To achieve this goal, two Thai SOEs were studied, both of which faced challenges in the implementation of Economic Value Management (EVM) and Balance Scorecard (BSC) as well as difficulties in linking their individual BSC and incentive systems. The qualitative data were collected from semi-structured interviews and document reviews. The empirical aspects of this study reveal that the institutional logics in the field of Thai SOEs are the logic of bureaucracy, commercial operations, social activities, seniority and unity. Regarding the multiple institutional logics embedded, SOEs experienced the institutional complexity in the implementation of PMS. The results suggest that the organisations have decoupled the EVM and loosely coupled the BSC from organisational practices to cope with institutional complexity and conflict institutional demands. Also, the evidence shows that the institutional logics influence SOEs’ actions towards resisting changes incentive systems and the relationship between individual BSC and incentives.

Transaction attributes and buyer-supplier relationships in AMT acquisition and implementation:the case of Malaysia

This paper explores how transaction attributes of technology affect differences in the relationship between technology buyers and suppliers. It also examines the impact on performance of different patterns of relationship between technology buyers and suppliers. Data obtained from 147 manufacturing firms in Malaysia are used to test several hypotheses, which were derived from a review of the literature on technology, transaction cost theory and buyer–supplier relationships (BSR). The research results indicate that the higher the level of technological complexity, specificity and uncertainty, the more firms are likely to engage in a closer relationship with technology suppliers. Even though the majority of firms reported improvements in their performance, results indicate that firms demonstrating a closer relationship with technology suppliers are more likely to achieve higher levels of performance than those that do not. It is also shown that with high levels of transaction attribute, implementation performance suffers more when firms have weak relationships with technology suppliers than with moderate and low levels of transaction attribute.

The precursors and impacts of BSR on AMT acquisition and implementation

This paper reports on the results of research into the connections between transaction attributes and buyer-supplier relationships (BSRs) in advanced manufacturing technology (AMT) acquisition and implementation. The investigation began by examining the impact of the different patterns of BSR on the performance of the AMT acquisition. In understanding the phenomena, the study drew upon and integrated the literature of transaction cost economics theory, BSRs, and AMT, and used this as the basis for a theoretical framework and hypotheses development. This framework was then empirically tested using data that were gathered through a questionnaire survey with 147 companies and analyzed using a structural equation modeling technique. The results of the analysis indicated that the higher the level of technological specificity and uncertainty, the more firms are likely to engage in a stronger relationship with technology suppliers. However, the complexity of the technology being implemented was associated with BSR only indirectly through its association with the level of uncertainty (which has a direct impact upon BSR). The analysis also provided strong support for the premise that developing strong BSR could lead to an improved performance in acquiring and implementing AMT. The implications of the study are offered for both the academic and practitioner audience.

Risk based decision support system for effective implementation of projects

Conventional project management techniques are not always sufficient to ensure time, cost and quality achievement of large-scale construction projects due to complexity in planning, design and implementation processes. The main reasons for project non-achievement are changes in scope and design, changes in government policies and regulations, unforeseen inflation, underestimation and improper estimation. Projects that are exposed to such an uncertain environment can be effectively managed with the application of risk management throughout the project's life cycle. However, the effectiveness of risk management depends on the technique through which the effects of risk factors are analysed/quantified. This study proposes the Analytic Hierarchy Process (AHP), a multiple attribute decision making technique, as a tool for risk analysis because it can handle subjective as well as objective factors in a decision model that are conflicting in nature. This provides a decision support system (DSS) to project management for making the right decision at the right time for ensuring project success in line with organisation policy, project objectives and a competitive business environment. The whole methodology is explained through a case application of a cross-country petroleum pipeline project in India and its effectiveness in project management is demonstrated.

Time complexity and convergence analysis of domain theoretic Picard method

We present an implementation of the domain-theoretic Picard method for solving initial value problems (IVPs) introduced by Edalat and Pattinson [1]. Compared to Edalat and Pattinson's implementation, our algorithm uses a more efficient arithmetic based on an arbitrary precision floating-point library. Despite the additional overestimations due to floating-point rounding, we obtain a similar bound on the convergence rate of the produced approximations. Moreover, our convergence analysis is detailed enough to allow a static optimisation in the growth of the precision used in successive Picard iterations. Such optimisation greatly improves the efficiency of the solving process. Although a similar optimisation could be performed dynamically without our analysis, a static one gives us a significant advantage: we are able to predict the time it will take the solver to obtain an approximation of a certain (arbitrarily high) quality.

Buyer-supplier relationships in advanced manufacturing technology acquisition and implementation : a study in Malaysia

This thesis reports the results of research into the connections between transaction attributes and buyer-supplier relationships (BSR) in advanced manufacturing technology (AMT) acquisitions and implementation. It also examines the impact of the different patterns of BSR on performance. Specifically, it addresses the issues of how the three transaction attributes; namely level of complexity, level of asset specificity, and level of uncertainty, can affect the relationships between the technology buyer and suppler in AMT acquisition and implementation, and then to see the impact of different patterns of BSR on the two aspect of performance; namely technology and implementation performance. In understanding the pohenomena, the study mainly draws on and integrates the literature of transaction cost economics theory,buyer-supplier relationships and advanced manufacturing technology as a basis of theoretical framework and hypotheses development.data were gathered through a questionnaire survey with 147 responses and seven semi-structured interviews of manufacturing firms in Malaysia. Quantitative data were analysed mainly using the AMOS (Analysis of Moment Structure) package for structural equation modeling and SPSS (Statistical Package for Social Science) for analysis of variance (ANOVA). Data from interview sessions were used to develop a case study with the intention of providing a richer and deeper understanding on the subject under investigation and to offer triangulation in the research process. he results of the questionnaire survey indicate that the higher the level of technological specificity and uncertainty, the more firms are likely to engage in a closer relationship with technology suppliers.However, the complexity of the technology being implemented is associated with BSR only because it is associated with the level of uncertainty that has direct impact upon BSR.The analysis also provides strong support for the premise that developing strong BSR could lead to an improved performance. However, with high levels of transaction attribute, implementation performance suffers more when firms have weak relationships with technology suppliers than with moderate and low levels of transaction attributes. The implications of the study are offered for both the academic and practitioner audience. The thesis closes with reports on its limitations and suggestions for further research that would address some of these limitations.