Dissipative nonlinear structures in fiber optics

Optical fiber materials exhibit a nonlinear response to strong electric fields, such as those of optical signals confined within the small fiber core. Fiber nonlinearity is an essential component in the design of the next generation of advanced optical communication systems, but its use is often avoided by engineers because of its intractability. The application of nonlinear technologies in fiber optics offers new opportunities for the design of photonic systems and devices. In this chapter, we make an overview of recent progress in mathematical theory and practical applications of temporal dissipative solitons and self-similar nonlinear structures in optical fiber systems. The design of all-optical high-speed signal processing devices, based on nonlinear dissipative structures, is discussed.

Localized waves in optical systems with periodic dispersion and nonlinearity management

We overview our recent developments in the theory of dispersion-managed (DM) solitons within the context of optical applications. First, we present a class of localized solutions with a period multiple to that of the standard DM soliton in the nonlinear Schrödinger equation with periodic variations of the dispersion. In the framework of a reduced ordinary differential equation-based model, we discuss the key features of these structures, such as a smaller energy compared to traditional DM solitons with the same temporal width. Next, we present new results on dissipative DM solitons, which occur in the context of mode-locked lasers. By means of numerical simulations and a reduced variational model of the complex Ginzburg-Landau equation, we analyze the influence of the different dissipative processes that take place in a laser.

A comparison of beta-amyloid deposition in the medial temporal lobe in sporadic Alzheimer's disease, Down's syndrome and normal elderly brains

The density of beta-amyloid (A beta) deposits was studied in the medial temporal lobe in non-demented individuals and in sporadic Alzheimer's disease (SAD) and Down's syndrome (DS). No A beta deposits were recorded in six of the non-demented cases, while in a further eight cases, these were confined to either the lateral occipitotemporal or parahippocampal gyrus. The mean density of A beta deposits in the cortex was greater in SAD and DS than in non-demented cases but with overlap between patient groups. The mean density of A beta deposits was greater in DS than SAD consistent with a gene dosage effect. The ratio of primitive to diffuse A beta deposits was greater in DS and in non-demented cases than in SAD and the ratio of classic to diffuse deposits was lowest in DS. In all groups, A beta deposits occurred in clusters which were often regularly distributed. In the cortex, the dimension of the A beta clusters was greater in SAD than in the non-demented cases and DS. The data suggest that the development of A beta pathology in the hippocampus could be a factor in the development of DS and SAD. Furthermore, the high density of A beta deposits, and in particular the high proportion of primitive type deposits, may be important in DS while the development of large clusters of A beta deposits may be a factor in SAD.

Stakeholders' perceptions of corporate social reporting in Bangladesh

Recent calls in the corporate social reporting (CSRep) literature have emphasized the importance of giving voice to non-managerial stakeholder groups in the social reporting process. The research, presented in this paper, employs recent work in stakeholder theory and CSRep to examine the perceptions of a diverse set of non-managerial stakeholders in the context of a developing country, Bangladesh. A series of semi-structured interviews were conducted with individuals who identify with various non-managerial stakeholder groups. Interviewees generally believed that the motivation and practice of CSRep in Bangladesh is developing in response to pressures from international markets and is producing largely cosmetic responses. Also, they expressed concerns that, given the economic, political, and social conditions in Bangladesh, premature adoption of strict CSRep standards may lead to increased corruption and other unintended consequences. Whilst some of the interviewees sharply criticized the current process of imposing social accounting codes/standards on developing countries which fail to consider the important local socio-economic context, the findings suggest that there is overwhelming support for mandatory externally verified CSRep based on the principles of peoples' right to know, full disclosure/completeness, and relevance, which are anchored in the broader principles of transparency and stakeholder accountability. © 2010 Springer Science+Business Media B.V.

Recent advances in fibre grating devices and their sensing applications

Over the last twenty years, we have been continuously seeing R&D efforts and activities in developing optical fibre grating devices and technologies and exploring their applications for telecommunications, optical signal processing and smart sensing, and recently for medical care and biophotonics. In addition, we have also witnessed successful commercialisation of these R&Ds, especially in the area of fibre Bragg grating (FBG) based distributed sensor network systems and technologies for engineering structure monitoring in industrial sectors such as oil, energy and civil engineering. Despite countless published reports and papers and commercial realisation, we are still seeing significant and novel research activities in this area. This invited paper will give an overview on recent advances in fibre grating devices and their sensing applications with a focus on novel fibre gratings and their functions and grating structures in speciality fibres. The most recent developments in (i) femtosecond inscription for microfluidic/grating devices, (2) tilted grating based novel polarisation devices and (3) dual-peak long-period grating based DNA hybridisation sensors will be discussed.

Dissipative nonlinear structures in fiber optics

Optical fiber materials exhibit a nonlinear response to strong electric fields, such as those of optical signals confined within the small fiber core. Fiber nonlinearity is an essential component in the design of the next generation of advanced optical communication systems, but its use is often avoided by engineers because of its intractability. The application of nonlinear technologies in fiber optics offers new opportunities for the design of photonic systems and devices. In this chapter, we make an overview of recent progress in mathematical theory and practical applications of temporal dissipative solitons and self-similar nonlinear structures in optical fiber systems. The design of all-optical high-speed signal processing devices, based on nonlinear dissipative structures, is discussed.

Optimization of the Investment Portfolio in the Conditions of Uncertainty

Portfolio analysis exists, perhaps, as long, as people think about acceptance of rational decisions connected with use of the limited resources. However the occurrence moment of portfolio analysis can be dated precisely enough is having connected it with a publication of pioneer work of Harry Markovittz (Markovitz H. Portfolio Selection) in 1952. The model offered in this work, simple enough in essence, has allowed catching the basic features of the financial market, from the point of view of the investor, and has supplied the last with the tool for development of rational investment decisions. The central problem in Markovitz theory is the portfolio choice that is a set of operations. Thus in estimation, both separate operations and their portfolios two major factors are considered: profitableness and risk of operations and their portfolios. The risk thus receives a quantitative estimation. The account of mutual correlation dependences between profitablenesses of operations appears the essential moment in the theory. This account allows making effective diversification of portfolio, leading to essential decrease in risk of a portfolio in comparison with risk of the operations included in it. At last, the quantitative characteristic of the basic investment characteristics allows defining and solving a problem of a choice of an optimum portfolio in the form of a problem of quadratic optimization.

On a Five-Diagonal Jacobi Matrices and Orthogonal Polynomials on Rays in the Complex Plane

∗ Partially supported by Grant MM-428/94 of MESC.

Localized waves in optical systems with periodic dispersion and nonlinearity management

We overview our recent developments in the theory of dispersion-managed (DM) solitons within the context of optical applications. First, we present a class of localized solutions with a period multiple to that of the standard DM soliton in the nonlinear Schrödinger equation with periodic variations of the dispersion. In the framework of a reduced ordinary differential equation-based model, we discuss the key features of these structures, such as a smaller energy compared to traditional DM solitons with the same temporal width. Next, we present new results on dissipative DM solitons, which occur in the context of mode-locked lasers. By means of numerical simulations and a reduced variational model of the complex Ginzburg-Landau equation, we analyze the influence of the different dissipative processes that take place in a laser.

On Two Saigo’s Fractional Integral Operators in the Class of Univalent Functions

2000 Mathematics Subject Classification: Primary 26A33, 30C45; Secondary 33A35

Existence Results for Fractional Functional Differential Inclusions with Infinite Delay and Applications to Control Theory

Mathematics Subject Classification: 26A33, 34A60, 34K40, 93B05

An empirical study of international private label branding in the food sector in Hungary

Private label branding strategies differ to that of the manufacturer. The study aims to identify optimal private label branding strategies for (a) utilitarian products and (b) hedonistic products, considering the special factors reflected in consumer behavior related to private labels in Hungary. The issue of House of Brands and Branded House strategies are discussed and evaluated in the light of retail business models. Focus group interviews and factor analysis of the survey found differences in branding strategies preferred by consumers for the two product categories. The study also outlines a strong trend in possible private label development based on consumer’s changing attitude in favor of national products.

E-commerce evolution in Hungary: an investigation of critical succes factor

In this paper we highlight how the use of internet has changed from 2004 to 2009 among Hungarian companies, how their expectations about the role of e-commerce as a competitive advantage has evolved and whether perceived benefits of e-commerce show a shift from 2004 to 2009.We investigate the role of environmental factors and market orientation as two relevant types of critical success factors proposed by the management literature and measure their impacts on Internet usage, expectations about e-commerce and perceived benefits of ecommerce. Our findings suggest that market orientation has a positive effect on Internet usage and perceived benefits of e-commerce. Internet usage and expectations are dependent on the vulnerability of the company to its macroeconomic environment. The positive outcomes of joining the EU seem to influence whether a company is able to exploit e-commerce benefits.

The role of enduring involvement in the relationship between reference price and price acceptance in the context of multichannel choice

Understanding online price acceptance and its determining factors can be essential if the companies try to manage different type of channels. The paper aimed to reveal the role of enduring involvement in price acceptance in a multichannel (online and offline) context. The study revealed that the hedonic value of shopping can increase the negative intention of price acceptance in the online channel, but also explored that for the segment without shopping motivations a similar price level can be applied both in the online and in the offline environment.

Grounded theory, a kvalitatív kutatás klasszikus mérföldköve (Grounded theory, the classic milestone of qualitative research)

A grounded theory olyan kutatási módszer, ahol az elmélet az empirikus adatokból fejlődik ki és abban gyökerezik (Glaser - Strauss, 1967). Annak ellenére, hogy a módszer nemzetközileg rendkívül népszerű, a grounded theory nem igazán vert gyökeret a hazai menedzsment- és marketingkutatás talajában. A cikk célja a grounded theory kulcsfontosságú mozzanatainak bemutatása és a módszer népszerűsítése. / === / Grounded theory is a research method in which theory emerges from the data and is grounded in it (Glaser - Strauss, 1967). Despite the international popularity of the method, the grounded theory unfortunately hasn't taken roots in the Hungarian management and marketing research fields. The purpose of this article is to highlight some features and key points of the method and to popularize it among researchers.