Asymptotic analysis for the coupled wavenumbers in an infinite fluid-filled flexible cylindrical shell: The beam mode

Using asymptotics, the coupled wavenumbers in an infinite fluid-filled flexible cylindrical shell vibrating in the beam mode (viz. circumferential wave order n = 1) are studied. Initially, the uncoupled wavenumbers of the acoustic fluid and the cylindrical shell structure are discussed. Simple closed form expressions for the structural wavenumbers (longitudinal, torsional and bending) are derived using asymptotic methods for low- and high-frequencies. It is found that at low frequencies the cylinder in the beam mode behaves like a Timoshenko beam. Next, the coupled dispersion equation of the system is rewritten in the form of the uncoupled dispersion equation of the structure and the acoustic fluid, with an added fluid-loading term involving a parameter mu due to the coupling. An asymptotic expansion involving mu is substituted in this equation. Analytical expressions are derived for the coupled wavenumbers (as modifications to the uncoupled wavenumbers) separately for low- and high-frequency ranges and further, within each frequency range, for large and small values of mu. Only the flexural wavenumber, the first rigid duct acoustic cut-on wavenumber and the first pressure-release acoustic cut-on wavenumber are considered. The general trend found is that for small mu, the coupled wavenumbers are close to the in vacuo structural wavenumber and the wavenumbers of the rigid-acoustic duct. With increasing mu, the perturbations increase, until the coupled wavenumbers are better identified as perturbations to the pressure-release wavenumbers. The systematic derivation for the separate cases of small and large mu gives more insight into the physics and helps to continuously track the wavenumber solutions as the fluid-loading parameter is varied from small to large values. Also, it is found that at any frequency where two wavenumbers intersect in the uncoupled analysis, there is no more an intersection in the coupled case, but a gap is created at that frequency. This method of asymptotics is simple to implement using a symbolic computation package (like Maple). (C) 2008 Elsevier Ltd. All rights reserved.

Diffusion of flexible, charged, nanoscopic molecules in solution: Size and pH dependence for PAMAM dendrimer

In order to understand self-diffusion (D) of a charged, flexible, and porous nanoscopic molecule in water, we carry out very long, fully atomistic molecular dynamics simulation of PAMAM dendrimer up to eight generations in explicit salt water under varying pH. We find that while the radius of gyration (R-g) varies as N-1/3, the self-diffusion constant (D) scales, surprisingly, as N-alpha, with alpha=0.39 at high pH and 0.5 at neutral pH, indicating a dramatic breakdown of Stokes-Einstein relation for diffusion of charged nanoscopic molecules. The variation in D as a function of radius of gyration demonstrates the importance of treating water and ions explicitly in the diffusion process of a flexible nanoscopic molecule. In agreement with recent experiments, the self-diffusion constant increases with pH, revealing the importance of dielectric friction in the diffusion process. The shape of a dendrimer is found to fluctuate on a nanosecond time scale. We argue that this flexibility (and also the porosity) of the dendrimer may play an important role in determining the mean square displacement of the dendrimer and the breakdown of the Stokes-Einstein relation between diffusion constant and the radius.

Asymptotic analysis for the coupled wavenumbers in an infinite fluid-filled flexible cylindrical shell: The axisymmetric mode

The coupled wavenumbers of a fluid-filled flexible cylindrical shell vibrating in the axisymmetric mode are studied. The coupled dispersion equation of the system is rewritten in the form of the uncoupled dispersion equation of the structure and the acoustic fluid, with an added fluid-loading term involving a parameter e due to the coupling. Using the smallness of Poisson's ratio (v), a double-asymptotic expansion involving e and v 2 is substituted in this equation. Analytical expressions are derived for the coupled wavenumbers (for large and small values of E). Different asymptotic expansions are used for different frequency ranges with continuous transitions occurring between them. The wavenumber solutions are continuously tracked as e varies from small to large values. A general trend observed is that a given wavenumber branch transits from a rigidwalled solution to a pressure-release solution with increasing E. Also, it is found that at any frequency where two wavenumbers intersect in the uncoupled analysis, there is no more an intersection in the coupled case, but a gap is created at that frequency. Only the axisymmetric mode is considered. However, the method can be extended to the higher order modes.

Interdependence between Greece and other European stock markets: A comparison of wavelet and VMD copula, and the portfolio implications

The interdependence of Greece and other European stock markets and the subsequent portfolio implications are examined in wavelet and variational mode decomposition domain. In applying the decomposition techniques, we analyze the structural properties of data and distinguish between short and long term dynamics of stock market returns. First, the GARCH-type models are fitted to obtain the standardized residuals. Next, different copula functions are evaluated, and based on the conventional information criteria and time varying parameter, Joe-Clayton copula is chosen to model the tail dependence between the stock markets. The short-run lower tail dependence time paths show a sudden increase in comovement during the global financial crises. The results of the long-run dependence suggest that European stock markets have higher interdependence with Greece stock market. Individual country’s Value at Risk (VaR) separates the countries into two distinct groups. Finally, the two-asset portfolio VaR measures provide potential markets for Greece stock market investment diversification.

High-Throughput Flexible Constraint Length Viterbi Decoders on De Bruijn, Shuffle-Exchange and Butterfly Connected Architectures

Flexible constraint length channel decoders are required for software defined radios. This paper presents a novel scalable scheme for realizing flexible constraint length Viterbi decoders on a de Bruijn interconnection network. Architectures for flexible decoders using the flattened butterfly and shuffle-exchange networks are also described. It is shown that these networks provide favourable substrates for realizing flexible convolutional decoders. Synthesis results for the three networks are provided and a comparison is performed. An architecture based on a 2D-mesh, which is a topology having a nominally lesser silicon area requirement, is also considered as a fourth point for comparison. It is found that of all the networks considered, the de Bruijn network offers the best tradeoff in terms of area versus throughput.

Pelon ja toivon välissä : Pätkätyöläisen urakerronta

This study analyzes the forming of the occupational identity of the well-educated fixed-term employees. Fixed-term employment contracts amongst the well-educated labour force are exceptionally common in Finland as compared to other European countries. Two groups of modern fixed-term employees are distinguished. The first comprises well-educated women employed in the public sector whose fixed-term employment often consists of successive periods as temporary substitutes. The other group comprises well-educated, upper white-collar men aged over 40, whose fixed-term employment careers often consist of jobs of project nature or posts that are filled for a fixed period only. Method of the study For the empirical data I interviewed 35 persons (26 women and 9 men) in 33 interviews, one of which was conducted by e-mail and one was a group interview. All the interviews were electronically recorded and coded. All the interviewees have two things in common: fixed-term employment and formal high education. Thirteen (13) of them are researchers, four nurses, four midwives, four journalists, and ten project experts. I used the snowball method to get in touch the interviewees. The first interviewees were those who were recommended by the trade unions and by my personal acquaintances. These interviewees, in turn, recommended other potential interviewees. In addition, announcements on the internet pages of the trade unions were used to reach other interviewees. In analysing process I read the research material several times to find the turning points in the narrative the interviewees told. I also searched for the most meaningful stories told and the meaning the interviewees gave to these stories and to the whole narrative. In addition to that I paid attention to co-production of the narrative with the interviewees and analyzed the narrative as performance to be able to search for the preferred identities the interviewees perform. (Riesman 2001, 698-701). I do not pay much attention to the question of truth of a narrative in the sense of its correspondence with facts; rather I think a working life narrative has two tasks: On the one hand one has to tell the facts and on the other hand, he/she has to describe the meaning of these facts to herself/himself. To emphasize the double nature of the narrative about one’s working life I analyzed the empirical data both by categorizing it according to the cultural models of storytelling (heroic story, comedy, irony and tragedy) and by studying the themes most of the interviewees talked about. Ethics of the study I chose to use narrative within qualitative interviews on the grounds that in my opinion is more ethical and more empowering than the more traditional structured interview methods. During the research process I carefully followed the ethical rules of a qualitative research. The purpose of the interviews and the research was told to the interviewees by giving them a written description of the study. Oral permission to use the interview in this research was obtained from the interviewees. The names and places, which are mentioned in the study, are changed to conceal the actual identity of the interviewees. I shared the analysis with the interviewees by sending each of them the first analysis of their personal interview. This way I asked them to make sure that the identity was hidden well enough and hoped to give interviewees a chance to look at their narratives, to instigate new actions and sustain the present one (Smith 2001, 721). Also I hoped to enjoy a new possibility of joint authorship. Main results As a result of the study I introduce six models of telling a story. The four typical western cultural models that guide the telling are: heroic story, comedy, tragedy and satirical story (Hänninen 1999). In addition to these models I found two ways of telling a career filled with fixed-term employments that differ significantly from traditional career story telling. However, the story models in which the interviewees pour their experience locates the fixed term employers work career in an imagined life trajectory and reveals the meaning they give to it. I analyze the many sided heroic story that Liisa tells as an example of the strength of the fear of failing or losing the job the fixed term employee feels. By this structure it is also possible to show that success is felt to be entirely a matter of chance. Tragedy, the failure in one’s trial to get something, is a model I introduce with the help of Vilppu’s story. This narrative gets its meaning both from the sorrow of the failure in the past and the rise of something new the teller has found. Aino tells her story as a comedy. By introducing her narrative, I suggest that the purpose of the comedy, a stronger social consensus, gets deeper and darker shade by fixed-term employment: one who works as a fixed term employee has to take his/her place in his/her work community by him/herself without the support the community gives to those in permanent position. By studying the satiric model Rauno uses, I argue that using irony both turns the power structures to a carnival and builds free space to the teller of the story and to the listener. Irony also helps in building a consensus, mutual understanding, between the teller and the listener and it shows the distance the teller tells to exist between him and others. Irony, however, demands some kind of success in one’s occupational career but also at least a minor disappointment in the progress of it. Helmi tells her story merely as a detective story. By introducing Helmi’s narrative, I argue that this story model strengthens the trust in fairness of the society the teller and the listener share. The analysis also emphasizes the central position of identity work, which is caused by fixed-term employment. Most of the interviewees talked about getting along in working life. I introduced Sari’s narrative as an example of this. In both of these latter narratives one’s personal character and habits are lifted as permanent parts of the actual professional expertise, which in turn varies according to different situations. By introducing these models, I reveal that the fixed-term employees have different strategies to cope with their job situations and these strategies vary according to their personal motives and situations and the actual purpose of the interview. However, I argue that they feel the space between their hopes and fears narrow and unsecure. In the research report I also introduce pieces of the stories – themes – that the interviewees use to build these survival strategies. They use their personal curriculum vitae or portfolio, their position in work community and their work morals to build their professional identity. Professional identity is flexible and varies in time and place, but even then it offers a tool to fix one’s identity work into something. It offers a viewpoint to society and a tool to measure one’s position in surrounding social nets. As one result of the study I analyze the position the fixed-term employees share on the edge of their job communities. I summarize the hopes and fears the interviewees have concerning employers, trade unions, educational institutions and the whole society. In their opinion, the solidarity between people has been weakened by the short-sighted power of the economy. The impact the fixed-term employment has on one’s professional identity and social capital is a many-sided and versatile process. Fixed-term employment both strengthens and weakens the professional identity, social capital and the building of trust. Fixed-term employment also affects one’s day-to-day life by excluding her/him from the norm and by one’s difficulty in making long-term plans (Jokinen 2005). Regardless of the nature of the job contract, the workers themselves are experts in making the best of their sometimes less than satisfying work life and they also build their professional identity by using creatively their education, work experiences and interpersonal relations. However, a long career of short fixed-term employments may seriously change the perception of employee about his/her role. He/she may start concentrating only in coping in his/her unsatisfactory situation and leaves the active improvement of the lousy working conditions to other people. Keywords: narrative, fixed-tem employment, occupational identity, work, story model, social capital, career  

Suomalaisten yritysten vapaaehtoinen sosiaalinen vastuu : Sidosryhmäviitekehys yritysten ja ulkoisten sidosryhmien edustajien näkemyksissä

Corporate social responsibility (CSR) is no longer only an issue of companies but a concern shared by e.g. the European Union, the International Labour Organization, labour market organizations and many others. This thesis examines what kind of voluntary corporate social responsibility exceeding the minimum level set in the legislation can be expected from the Finnish companies. The research was based on the interviews of some representatives of Finnish companies and of external stakeholders. Earlier Finnish empirical research on the topic has solely analysed the stakeholder thinking and the ethics of the views of the company representatives. The views of the external stakeholders brought ht up a much more versatile perspective on the voluntary corporate social responsibility of the companies. That is the particular surplus value of this research. This research, founded on stakeholder thinking, evaluated what kind of starting points and ideas on responsibility the views of the representatives of the companies and the external stakeholders were based on the voluntary social responsibility. Furthermore, the research also investigated how their views about the corporate social responsibility indicated the benefits achieved on the cooperative actions with different partners - for example companies, communities and public administration. To fulfil the aims of the research, the following questions were used as part tasks in mapping the basic foundations and starting points expressed by the representatives of the companies and the external stakeholders: 1) How do laws, directions concerning social responsibility of companies, and opinions and demands of the stakeholders guide and affect the voluntary corporate social responsibility? 2) How can companies assume voluntary corporate social responsibility in addition to their core functions and without compromising their profitability, and how does, for example, the tightening competition affect the possibility of taking responsibility? 3) What kind of ethic and moral foundations is the corporate social responsibility based on? 4) What kind of roles can companies have in securing and promoting the well-being of citizens in Finland and on the global market as one subsystem of the society? The views on the voluntary corporate social responsibility of nine big companies, one medium-sized company and one small company, all considered responsible pioneer companies, were studied with surveys and half-structured theme interviews between 2003 and 2004. The research proceeded as a theory-bounded study. The empirical material and the previous stakeholder thinking theories (Takala 2000b, Vehkaperä 2003) guided the thesis and worked abductively in interplay with each other during the research process. (Tuomi, Sarajärvi 2002.) The aims and the methods of the research and the themes of the interviews were defined on the basis of that information. The aims of the research were surveyed qualitatively with the strategy of a multiple case study. Representatives from nine big peer companies and nine external stakeholders were interviewed with half-structured themes between 2004 and 2005. The external stakeholders and the peer companies were chosen with the "thinking" of theoretical replication by Yin, according to which the views of the representatives of those groups would differ from those of the pioneer companies and also from those of each others. The multiple case study supports analysing the internal cohesion of the views of different groups and comparing their differences, and it supports theoretical evaluation and theory-building as well. (Yin 2003.) Another reason for choosing the external stakeholders was their known cooperation with companies. The spoken argumentations of the company and stakeholder representatives on the voluntary social responsibility of the companies were analysed and interpreted in the first place with an analytic discourse analysis, and the argumentations were classified allusively into the stakeholder discourses in three of the part tasks. In the discourse analysis, argumentations of the speech is seen to be intervowen with cultural meanings. (Jokinen, Juhila 1999.) The views of the representatives of the pioneer companies and the external stakeholders were more stakeholder-orientated than the views of the representatives of the peer companies. For the most part, the voluntary corporate social responsibility was seemingly targeted on single, small cooperation projects of the companies and external stakeholders. The pioneer companies had more of those projects, and they were participating in the projects more actively than the peer companies were. The significant result in this research was the notion that, in particular, the representatives of the pioneer companies and external stakeholders did not consider employing and paying taxes to be enough of reciprocal corporate social responsibility. However, they still wanted to preserve the Finnish welfare model, and the interviewees did not wish major changes in the present legislation or the social agreements. According to this study, the voluntary corporate social responsibility is motivated by ethical utilitarianism which varied from very narrow to very wide in relation to benefits achieved by companies and stakeholders (Velasquez 2002, Lagerspetz 2004). Compared with the peer companies, more of the representatives of the pioneer companies and of external stakeholders estimated that companies in their decision-making and operations considered not only the advantages and the benefits of the owners and other internal stakeholders, but also those of the external stakeholders and of the whole society. However, all interviewees expressed more or less strongly that the economic responsibility guides the voluntary responsible actions of the companies in the first place. This kind of utilitarian foundation of behaviour appeared from this research was named as business-orientated company moral. This thesis also presents a new voluntary corporate social responsibility model with four variables on the stakeholder discourses and their distinctive characteristics. The utilitarian motivation of a company s behaviour on their operations has been criticized on the grounds that the end justifies the means. It has also been stated that it is impossible to evaluate the benefits of the utilitarian type of actions to the individuals and the society. It is expected however that companies for their part promote the material and immaterial well-being of the individuals on the global, national and local markets. The expectations are so strong that if companies do not take into account the ethical and moral values, they can possibly suffer significant financial losses. All stakeholders, especially consumers, can with their own choices promote the responsible behaviour of the companies. Key words: voluntary corporate social responsibility, external stakeholders, corporate citizenship, ethics and morality, utilitarianism, stakeholder discourses, welfare society, globalisation

Conformation of the flexible bent helix of Leu1-zervamicin in crystal C and a possible gating action for ion passage

The membrane channel-forming polypeptide, Leu(1)-zervamicin, Ac-Leu-Ile-Gln-Iva-Ile(5)-Thr-Aib-Leu-Aib-Hyp(10) -Gln-Aib-Hyp-Aib-Pro(15)-Phol (Aib: alpha-aminoisobutyric acid; Iva: isovaline; Hyp: 4-hydroxyproline; Phol: phenylalininol) has been analyzed by x-ray diffraction in a third crystal form. Although the bent helix is quite similar to the conformations found in crystals A and B, the amount of bending is more severe with a bending angle approximate to 47 degrees, The water channel formed by the convex polar faces of neighboring helices is larger at the mouth than in crystals A and B, and the water sites have become disordered. The channel is interrupted in the middle by a hydrogen bond between the OH of Hyp(10) and the NH2 of the Gln(11) of a neighboring molecule. The side chain of Gln(11) is wrapped around the helix backbone in an unusual fashion in order that it can augment the polar side of the helix. In the present crystal C there appears to be an additional conformation for the Gln(11) side chain (with approximate to 20% occupancy) that opens the channel for possible ion passage. Structure parameters for C85H140N18O22.xH(2)O.C2H5OH are space group P2(1)2(1)2(1), a = 10.337 (2) Angstrom, b = 28.387 (7) Angstrom, c = 39.864 (11) Angstrom, Z = 4, agreement factor R = 12.99% for 3250 data observed > 3 sigma(F), resolution = 1.2 Angstrom. (C) 1994 John Wiley & Sons, Inc.

Regulating Food Consumption : Studies of change and variation in Europe

The role of people as buyers and eaters of food has changed significantly. From being protected by a paternalistic welfare state, people appear to be accorded more freedom and responsibility as individuals, where attention is redirected from the state towards market relations. Many have asserted that these changes are accompanied by fragmentation, individualisation, and privatisation, leading to individual uncertainty and lack of confidence. But empirical observations do not always confirm this, distrust is not necessarily growing and while responsibilities may change, the state still plays an active role. This dissertation explores changing relationships between states and markets, on the one hand, and ordinary people in their capacities as consumers and citizens, on the other. Do we see the emergence of new forms of regulation of food consumption? If so, what is the scope and what are the characteristics? Theories of regulation addressing questions about individualisation and self-governance are combined with a conceptualisation of consumption as processes of institutionalisation, involving daily routines, the division of labour between production and consumption, and the institutional field in which consumption is embedded. The analyses focus on the involvement of the state, food producers and scientific, first of all nutritional, expertise in regulating consumption, and on popular responses. Two periods come out as important, first when the ideas of “designing the good life” emerged, giving the state a very particular role in regulating food consumption, and, second, when this “designing” is replaced by ideas of choice and individual responsibility. One might say that “consumer choice” has become a mode of regulation. I use mainly historical studies from Norway to analyse the shifting role of the state in regulating food consumption, complemented with population surveys from six European countries to study how modernisation processes are associated with trust. The studies find that changing regulation is not only a question of societal or state vs individual responsibilities. Degrees of organisation and formalisation are important as well. While increasing organisation may represent discipline and abuses of power (including exploitation of consumer loyalty), organisation can also, to the consumer, provide higher predictability, systems to deal with malfeasance, and efficiency which may provide conditions for acting. The welfare state and the neo-liberal state have very different types of solutions. The welfare state solution is based on (national) egalitarianism, paternalism and discipline (of the market as well as households). Such solutions are still prominent in Norway. Individualisation and self-regulation may represent a regulatory response not only to a declining legitimacy of this kind of interventionism, but also increasing organisational complexity. This is reflected in large-scale re-regulation of markets as well as in relationships with households and consumers. Individualisation of responsibility is to the consumer not a matter of the number of choices that are presented on the shelves, but how choice as a form of consumer based involvement is institutionalised. It is recognition of people as “end-consumers”, as social actors, with systems of empowerment politically as well as via the provisioning system. ‘Consumer choice’ as a regulatory strategy includes not only communicative efforts to make people into “choosing consumers”, but also the provision of institutions which recognise consumer interests and agency. When this is lacking we find distrust as representing powerlessness. Individual responsibility-taking represents agency and is not always a matter of loyal support to shared goals, but involves protest and creativity. More informal (‘communitarian’) innovations may be an indication of that, where self-realisation is intimately combined with responsibility for social problems. But as solutions to counteract existing imbalances of power in the food market the impacts of such initiatives are probably more as part of consumer mobilisation and politicisation than as alternative provisioning.

Finnish and Austrian Wood Markets in a Changing Environment

At present the operating environment of sawmills in Europe is changing and there are uncertainties related in raw material supply in many countries. The changes in the operating environment of roundwood markets and the effects followed by these changes have brought up several interesting issues from the viewpoint of research. Lately new factors have been influencing the roundwood markets, such as increasing interest towards wood-based energy and implementation of new energy policies as well as changes in wood trade flows that affect the domestic markets in many countries. This Master’s thesis studies the adaptation ability of Finnish roundwood markets in a changing operating environment, aiming to produce an up-to-date analysis considering new development trends. The study concentrates on the roundwood markets from the viewpoint of sawmill industry since the industry is dependent on the functioning of the markets and sawmills are highly affected by the changes on the roundwood markets. To facilitate international comparison, the study is implemented by comparing Finnish and Austrian roundwood markets and analysing changes happening in the two countries. Finland and Austria share rather similar characteristics in the roundwood market structures, forest resources and forest ownership as well as production of roundwood and sawnwood. In addition they both are big exporters of forest industry products. In this study changes in the operating environment of sawmill industry both in Finland as well as in Austria are compared to each other aiming to recognise the main similarities and differences between the countries. In addition both development possibilities as well as challenges followed by the changes are discussed. The aim of the study is to define the main challenges and possibilities confronted by the actors on the markets and also to find new perspectives to approach these. The study is implemented as a qualitative study. The theoretical framework of the study describes the operating environment of wood markets from the viewpoint of the sawmill industry and represents the effects of supply and demand on the wood markets. The primary research material of the study was gathered by interviewing high level experts of forestry and sawmill industry in both Finland and Austria. The aim was to receive as extensive country specific viewpoint from the markets as possible, hence interviewees represented different parties of the markets. After creating country-specific profiles based on the theoretical framework a cross-country comparison was implemented. As a consequence the main similarities and differences in the operating environment and on the roundwood markets of Finland and Austria were recognized. In addition the main challenges and possibilites were identified. The results of the study offer a wide analysis regarding the main similarities and differences of the wood markets of Finland and Austria and their operating environments as well as concerning challenges and possibilities faced on the markets.