Towards a unified definition of supply chain management:the four fundamentals

A wide range of definitions of supply chain management (SCM) have been developed over the last three decades. The philosophy of SCM is based firmly on a recognition that it is only by working in a more integrated manner that competitive advantage can be maximised. However, for this to become a reality the development of common definitions and understandings between supply chain partners is a critical success factor. The corollary of this is that a lack of definitional consistency and a common understanding is an inhibitor to the successful adoption of SCM thinking in practice. This paper reviews a number of definitions of SCM, as well as discussions and analyses of such definitions. This leads to the central point posited in the paper – the need for a ‘unified definition’. Such a definitional construct, labelled the Four Fundamentals of SCM, is proposed with the core of the paper providing a narrative description of this construct based on a wide range of literature.

Information-theory analysis of skewed coding for suppression of pattern-dependent errors in digital communications

We present information-theory analysis of the tradeoff between bit-error rate improvement and the data-rate loss using skewed channel coding to suppress pattern-dependent errors in digital communications. Without loss of generality, we apply developed general theory to the particular example of a high-speed fiber communication system with a strong patterning effect. © 2007 IEEE.

Physics-inspired methods for networking and communications

Advances in statistical physics relating to our understanding of large-scale complex systems have recently been successfully applied in the context of communication networks. Statistical mechanics methods can be used to decompose global system behavior into simple local interactions. Thus, large-scale problems can be solved or approximated in a distributed manner with iterative lightweight local messaging. This survey discusses how statistical physics methodology can provide efficient solutions to hard network problems that are intractable by classical methods. We highlight three typical examples in the realm of networking and communications. In each case we show how a fundamental idea of statistical physics helps solve the problem in an efficient manner. In particular, we discuss how to perform multicast scheduling with message passing methods, how to improve coding using the crystallization process, and how to compute optimal routing by representing routes as interacting polymers.

Foreword to the special issue on European conference on optical communications (ECOC 2014)

The articles in this special section were presented at the European Conference on Optical Communications (ECOC) that was held on on 21???25 September 2014 in Cannes, France

Intellectual Communications and Contemporarly Technologies Alternatives of the Science Libraries

(Summary of: Varbanova-Dencheva, K. Intellectual communications and contemporarly technologies. Alternatives of the science libraries. Sofia, Marin Drinov academic publishing house. 2003, 114p. ) The new technologies and the globalization are the factors which have brought essential changes in human society and its environment. The unceasing dynamic changes imposed new strategies for survival and prosperity of institutions and people in the new conditions. The spheres with greatest potential for achieving competition priority are compatible to the fastness of research results implementation in each field of human activity. The extended knowledge requires narrower specialization as well as interdisciplinarity to solve the arising problems. The new research fields and trends are a synthesis of science and high technologies determined by the new discoveries. The present study aims at finding answers to the questions about the place of science library in the dynamic restructuring of research environment. The necessity of transformation of the scientific library’s genetically set functions from a guardian of the achieved knowledge to an active participant in the creation of new knowledge is a natural consequence of the processes and tendencies of the social medium. The priorities of Europe and USA for intensive creation of knowledge economics are at the first place and this requires intensification of that research an integral part of which are the new communications realized at a new technological level.

The Complex Unified Evolutionary Approach to the Creation of the Multilevel Distributed Control System of a Gas-transport Company

The objects of a large-scale gas-transport company (GTC) suggest a complex unified evolutionary approach, which covers basic building concepts, up-to-date technologies, models, methods and means that are used in the phases of design, adoption, maintenance and development of the multilevel automated distributed control systems (ADCS).. As a single methodological basis of the suggested approach three basic Concepts, which contain the basic methodological principles and conceptual provisions on the creation of distributed control systems, were worked out: systems of the lower level (ACS of the technological processes based on up-to-date SCADA), of the middle level (ACS of the operative-dispatch production control based on MES-systems) and of the high level (business process control on the basis of complex automated systems ERP).

Multi-wavelength source using low drive-voltage amplitude modulators for optical communications

A simple and cost-effective technique for generating a flat, square-shaped multi-wavelength optical comb with 42.6 GHz line spacing and over 0.5 THz of total bandwidth is presented. A detailed theoretical analysis is presented, showing that using two concatenated modulators driven with voltages of 3.5 Vp are necessary to generate 11 comb lines with a flatness below 2dB. This performance is experimentally demonstrated using two cascaded Versawave 40 Gbit/s low drive voltage electro-optic polarisation modulators, where an 11 channel optical comb with a flatness of 1.9 dB and a side-mode-suppression ratio (SMSR) of 12.6 dB was obtained.

Multi-band carrier-less amplitude and phase modulation for bandlimited visible light communications systems

Visible light communications is a technology with enormous potential for a wide range of applications within next generation transmission and broadcasting technologies. VLC offers simultaneous illumination and data communications by intensity modulating the optical power emitted by LEDs operating in the visible range of the electromagnetic spectrum (~370-780 nm). The major challenge in VLC systems to date has been in improving transmission speeds, considering the low bandwidths available with commercial LED devices. Thus, to improve the spectral usage, the research community has increasingly turned to advanced modulation formats such as orthogonal frequency-division multiplexing. In this article we introduce a new modulation scheme into the VLC domain; multiband carrier-less amplitude and phase modulation (m-CAP) and describe in detail its performance within the context of bandlimited systems.

A Unified Group-Theoretic Method on Improper Partial Semi-Bilateral Generating Functions

2000 Mathematics Subject Classification: 33A65, 33C20.

Experimental verification of visible light communications based on multi-band CAP modulation

A multi-band CAP system is experimentally demonstrated for the first time in VLC.We show that with an 8-CAP testbed spectral efficiencies (~4.75 b/s/Hz) at a realistic distance of 1 m can be reached.