14 resultados para Spent Working Time

em Helda - Digital Repository of University of Helsinki


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The ageing of the labour force and falling employment rates have forced policy makers in industrialized countries to find means of increasing the well-being of older workers and of lengthening their work careers. The main objective of this thesis was to study longitudinally how health, functional capacity, subjective well-being, and lifestyle change as people grow older, and what effect retirement has on these factors and on their relationships. The present study is a follow-up questionnaire study of Finnish municipal workers, conducted in 1981 to 1997 at the Finnish Institute of Occupational Health. In 1981, a postal questionnaire was sent to 7344 municipal workers in different parts of Finland. The respondents were born between 1923 and 1937. A total of 6257 persons responded to the first questionnaire. In the end, a total of 3817 persons had responded to all four (1981, 1985, 1992, 1997) questionnaires. (The response rate was 69% of the living participants). Cross-tabulations, comparison of means, logistic regression analyses and general linear models with repeated measures were used to derive the results. The transition from work life to retirement, and the following years as a pensioner were associated with many changes. Involvement in various activities increased during the transition stage but later decreased to the previous level. Physical exercise was an exception: it became increasingly popular over the years. Perceived health improved markedly from the working stage to the retirement transition stage, even though morbidity increased steadily during the follow-up. On the other hand, functional capacity decreased over the follow-up, especially among those who were occupationally active until the retirement stage. Subjective well-being remained stable during the follow-up period. There were, however, great differences based on the type of work, favouring those whose work had been mental in nature. The impact of activity level on maintaining well-being became greater during the follow-up, whereas the effect of physical functioning diminished. Good physical functioning and an active life-style contributed to staying on at work until normal retirement age. Also work-related factors, i.e. possibilities for development and influence at work, responsibility for others, meaningful work, and satisfaction with working time arrangements were positively related to continuing working. The transition from work to retirement had a positive impact on a person s health and functional capacity. The study results support the view that it should be possible to ease one s work pace during the last years of a work career. This might lower the threshold between work and retirement and convince people that there will still be time to enjoy retirement also a few years later.

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Distraction in the workplace is increasingly more common in the information age. Several tasks and sources of information compete for a worker's limited cognitive capacities in human-computer interaction (HCI). In some situations even very brief interruptions can have detrimental effects on memory. Nevertheless, in other situations where persons are continuously interrupted, virtually no interruption costs emerge. This dissertation attempts to reveal the mental conditions and causalities differentiating the two outcomes. The explanation, building on the theory of long-term working memory (LTWM; Ericsson and Kintsch, 1995), focuses on the active, skillful aspects of human cognition that enable the storage of task information beyond the temporary and unstable storage provided by short-term working memory (STWM). Its key postulate is called a retrieval structure an abstract, hierarchical knowledge representation built into long-term memory that can be utilized to encode, update, and retrieve products of cognitive processes carried out during skilled task performance. If certain criteria of practice and task processing are met, LTWM allows for the storage of large representations for long time periods, yet these representations can be accessed with the accuracy, reliability, and speed typical of STWM. The main thesis of the dissertation is that the ability to endure interruptions depends on the efficiency in which LTWM can be recruited for maintaing information. An observational study and a field experiment provide ecological evidence for this thesis. Mobile users were found to be able to carry out heavy interleaving and sequencing of tasks while interacting, and they exhibited several intricate time-sharing strategies to orchestrate interruptions in a way sensitive to both external and internal demands. Interruptions are inevitable, because they arise as natural consequences of the top-down and bottom-up control of multitasking. In this process the function of LTWM is to keep some representations ready for reactivation and others in a more passive state to prevent interference. The psychological reality of the main thesis received confirmatory evidence in a series of laboratory experiments. They indicate that after encoding into LTWM, task representations are safeguarded from interruptions, regardless of their intensity, complexity, or pacing. However, when LTWM cannot be deployed, the problems posed by interference in long-term memory and the limited capacity of the STWM surface. A major contribution of the dissertation is the analysis of when users must resort to poorer maintenance strategies, like temporal cues and STWM-based rehearsal. First, one experiment showed that task orientations can be associated with radically different patterns of retrieval cue encodings. Thus the nature of the processing of the interface determines which features will be available as retrieval cues and which must be maintained by other means. In another study it was demonstrated that if the speed of encoding into LTWM, a skill-dependent parameter, is slower than the processing speed allowed for by the task, interruption costs emerge. Contrary to the predictions of competing theories, these costs turned out to involve intrusions in addition to omissions. Finally, it was learned that in rapid visually oriented interaction, perceptual-procedural expectations guide task resumption, and neither STWM nor LTWM are utilized due to the fact that access is too slow. These findings imply a change in thinking about the design of interfaces. Several novel principles of design are presented, basing on the idea of supporting the deployment of LTWM in the main task.

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From the field to the academic sphere how teachers professional identities and roles have changed in post-war Finland This study explores teacher autobiographies. The span of the writings extends mainly from the Second World War to the new millennium. The autobiographers are mostly elementary and secondary school teachers in Finland, although there are a few who have worked in vocational schools, polytechnic institutes or one of the various adult education centres. The researcher is aware of the diversity among those educational institutions and their teachers, but wanted to concentrate on similarities rather than differences. The autobiographers have been explored with four different research questions in view. The first was to identify professional and personal elements and themes mentioned by teachers in writing about themselves. The second was to identify the factors that have affected those elements and themes. The third was to examine the kinds of literary forms teachers used in their autobiographies. The fourth was the most crucial and an endeavour to connect the previous questions: how teachers professional identities and roles have changed during the period studied. In the first five chapters the teachers voices come through clearly. Two of these chapters are organized in chronological order. The first is about childhood, youth and the time spent in school, the second deals with the years studying in university or teachers college and finally being recruited to the teachers. In these chapters the rural background of many teachers stands out, an issue that also emerged symbolically or de facto in the autobiographies. The chronological scheme changes to a thematic order, in which social matters (students, parents, colleagues) and teachers working circumstances are dealt with. Four selected autobiographies are examined closely. In these autobiographies five different types of teacher narratives can be identified. To begin with, teachers stressed their vocation, which is quite a normal work orientation for those working in the educational field. Others emphasised how they were looking for professional development; a few wrote about personal advancement as well. There are also narratives by teachers who simply drifted into the profession of teaching, while a few teachers felt unwelcome in their own schools. As for the changes that teachers have witnessed, there are also some themes that are widely shared. Most pointed out how the teacher has become more foster parent than educator, as real parents have withdrawn from their responsibilities of raising children. This theme was frequently broached, although attitude towards it and ways of handling the phenomenon differed substantially. Teachers also stressed how their profession has lost the aura and prestige it once had. At the same time teachers are being expected to collaborate more with their colleagues, which is not in line with the centuries-old tradition of working alone. Teachers seem to be in a state of flux, buffeted by elements of stability and change interacting simultaneously. Many teachers are demanding a re-examination of their working reality. Teachers long and intimate relationship with society and the state may be at a crossroads. Key words: teachers professional identity and role, autobiographical study, post-war Finland

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Intact function of working memory (WM) is essential for children and adults to cope with every day life. Children with deficits in WM mechanisms have learning difficulties that are often accompanied by behavioral problems. The neural processes subserving WM, and brain structures underlying this system, continue to develop during childhood till adolescence and young adulthood. With functional magnetic resonance imaging (fMRI) it is possible to investigate the organization and development of WM. The present thesis aimed to investigate, using behavioral and neuroimaging methods, whether mnemonic processing of spatial and nonspatial visual information is segregated in the developing and mature human brain. A further aim in this research was to investigate the organization and development of audiospatial and visuospatial information processing in WM. The behavioral results showed that spatial and nonspatial visual WM processing is segregated in the adult brain. The fMRI result in children suggested that memory load related processing of spatial and nonspatial visual information engages common cortical networks, whereas selective attention to either type of stimuli recruits partially segregated areas in the frontal, parietal and occipital cortices. Deactivation mechanisms that are important in the performance of WM tasks in adults are already operational in healthy school-aged children. Electrophysiological evidence suggested segregated mnemonic processing of visual and auditory location information. The results of the development of audiospatial and visuospatial WM demonstrate that WM performance improves with age, suggesting functional maturation of underlying cognitive processes and brain areas. The development of the performance of spatial WM tasks follows a different time course in boys and girls indicating a larger degree of immaturity in the male than female WM systems. Furthermore, the differences in mastering auditory and visual WM tasks may indicate that visual WM reaches functional maturity earlier than the corresponding auditory system. Spatial WM deficits may underlie some learning difficulties and behavioral problems related to impulsivity, difficulties in concentration, and hyperactivity. Alternatively, anxiety or depressive symptoms may affect WM function and the ability to concentrate, being thus the primary cause of poor academic achievement in children.

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This study examined the effects of the Greeks of the options and the trading results of delta hedging strategies, with three different time units or option-pricing models. These time units were calendar time, trading time and continuous time using discrete approximation (CTDA) time. The CTDA time model is a pricing model, that among others accounts for intraday and weekend, patterns in volatility. For the CTDA time model some additional theta measures, which were believed to be usable in trading, were developed. The study appears to verify that there were differences in the Greeks with different time units. It also revealed that these differences influence the delta hedging of options or portfolios. Although it is difficult to say anything about which is the most usable of the different time models, as this much depends on the traders view of the passing of time, different market conditions and different portfolios, the CTDA time model can be viewed as an attractive alternative.

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The likelihood ratio test of cointegration rank is the most widely used test for cointegration. Many studies have shown that its finite sample distribution is not well approximated by the limiting distribution. The article introduces and evaluates by Monte Carlo simulation experiments bootstrap and fast double bootstrap (FDB) algorithms for the likelihood ratio test. It finds that the performance of the bootstrap test is very good. The more sophisticated FDB produces a further improvement in cases where the performance of the asymptotic test is very unsatisfactory and the ordinary bootstrap does not work as well as it might. Furthermore, the Monte Carlo simulations provide a number of guidelines on when the bootstrap and FDB tests can be expected to work well. Finally, the tests are applied to US interest rates and international stock prices series. It is found that the asymptotic test tends to overestimate the cointegration rank, while the bootstrap and FDB tests choose the correct cointegration rank.

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The low predictive power of implied volatility in forecasting the subsequently realized volatility is a well-documented empirical puzzle. As suggested by e.g. Feinstein (1989), Jackwerth and Rubinstein (1996), and Bates (1997), we test whether unrealized expectations of jumps in volatility could explain this phenomenon. Our findings show that expectations of infrequently occurring jumps in volatility are indeed priced in implied volatility. This has two important consequences. First, implied volatility is actually expected to exceed realized volatility over long periods of time only to be greatly less than realized volatility during infrequently occurring periods of very high volatility. Second, the slope coefficient in the classic forecasting regression of realized volatility on implied volatility is very sensitive to the discrepancy between ex ante expected and ex post realized jump frequencies. If the in-sample frequency of positive volatility jumps is lower than ex ante assessed by the market, the classic regression test tends to reject the hypothesis of informational efficiency even if markets are informationally effective.

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This paper investigates the persistent pattern in the Helsinki Exchanges. The persistent pattern is analyzed using a time and a price approach. It is hypothesized that arrival times are related to movements in prices. Thus, the arrival times are defined as durations and formulated as an Autoregressive Conditional Duration (ACD) model as in Engle and Russell (1998). The prices are defined as price changes and formulated as a GARCH process including duration measures. The research question follows from market microstructure predictions about price intensities defined as time between price changes. The microstructure theory states that long transaction durations might be associated with both no news and bad news. Accordingly, short durations would be related to high volatility and long durations to low volatility. As a result, the spread will tend to be larger under intensive moments. The main findings of this study are 1) arrival times are positively autocorrelated and 2) long durations are associated with low volatility in the market.

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Bootstrap likelihood ratio tests of cointegration rank are commonly used because they tend to have rejection probabilities that are closer to the nominal level than the rejection probabilities of the correspond- ing asymptotic tests. The e¤ect of bootstrapping the test on its power is largely unknown. We show that a new computationally inexpensive procedure can be applied to the estimation of the power function of the bootstrap test of cointegration rank. The bootstrap test is found to have a power function close to that of the level-adjusted asymp- totic test. The bootstrap test estimates the level-adjusted power of the asymptotic test highly accurately. The bootstrap test may have low power to reject the null hypothesis of cointegration rank zero, or underestimate the cointegration rank. An empirical application to Euribor interest rates is provided as an illustration of the findings.

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This paper focuses on the time dimension in consumers’ image construction processes. Two new concepts are introduced to cover past consumer experiences about the company – image heritage, and the present image construction process - image-in-use. Image heritage and image-in-use captures the dynamic, relational, social, and contextual features of corporate image construction processes. Qualitative data from a retailing context were collected and analysed following a grounded theory approach. The study demonstrates that consumers’ corporate images have long roots in past experiences. Understanding consumers’ image heritage provides opportunities for understanding how consumers might interpret management initiatives and branding activities in the present.

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Ethnic minorities residential patterns and integration are widely discussed issues in many European countries. They have also become topical in Finland due to an increase in foreign migration, especially in recent decades. This dissertation contributes to debates associated with attempts to explain ethnic minorities residential patterns by examining the role of cultural factors and ethnic preferences of the residential choices of Somali and Russian immigrants in Finland. The research is based on in-depth interviews with Somali (n=24) and Russian (n=26) immigrants living in the Helsinki metropolitan area. Housing officials and social workers (n=18) working in cities of Helsinki and Vantaa were also interviewed. The results of this study show that propinquity to one s own ethnic group is important to Somalis living in Finland. This is important for maintaining their traditional, communal life styles, but also as a safe haven against the racism which they experience on a regular basis. They have a preference for mixed neighbourhoods that contain both native Finnish residents and some ethnic minorities. For Russians the spatial propinquity to their country people is less significant at the neighbourhood level. However, this is not to indicate the insignificance of intra-ethnic networks or one s cultural background. Rather, the differences in ethnic preferences between Somalis and Russians predominantly reflect their varying levels of exposure to racial harassment and diverse meanings that they give to social relations with their neighbours. According to this study, the time spent in a host-country and interactions with other ethnic groups affect ethnic preferences. The importance of one s own ethnic community also varies in accordance with life situations. Therefore, ethnic minorities residential preferences and choices should not be viewed as static or something deriving from cultural background alone. Residential preferences and aspirations are constantly being reshaped vis-à-vis to immigrants experiences. Past and present experiences and the way that immigrants observe the host society and its functions are important for the interpretation of residential preferences and patterns.

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Physical inactivity has become a major threat to public health worldwide. The Finnish health and welfare policies emphasize that the working population should maintain good health and functioning until their normal retirement age and remain in good health and independence later in life. Health behaviours like physical activity potentially play an important role in reaching this target as physical activity contributes to better physical fitness and to reduced risk of major chronic diseases. The aim of this study was to examine first whether the volume and intensity of leisure-time physical activity impacts on subsequent physical health functioning, sickness absence and disability retirement. The second aim was to examine changes in leisure-time physical activity of moderate and vigorous intensity after transition to retirement. This study is part of the ongoing Helsinki Health Study. The baseline data were collected by questionnaires in 2000 - 02 among the employees of the City of Helsinki aged 40 to 60. The follow-up survey data were collected in 2007. Data on sickness absence were obtained from the employer s (City of Helsinki) sickness absence registers and pension data were obtained from the Finnish Centre for Pensions. Leisure-time physical activity was measured in four grades of intensity and classified according to physical activity recommendations considering both the volume and intensity of physical activity. Statistical techniques including analysis of covariance, logistic regression, Cox proportional hazards models and Poisson regression were used. Employees who were vigorously active during leisure time especially had better physical health functioning than those physically inactive. High physical activity in particular contributed to the maintenance of good physical health functioning. High physical activity also reduced the risk of subsequent sickness absences as well as the risk of all-cause disability retirement and retirement due to musculoskeletal and mental causes. Among those transferred to old-age retirement moderate-intensity leisure-time physical activity increased on average by more than half an hour per week and in addition the occurrence of physical inactivity reduced. Such changes were not observed among those remained employed and those transferred to disability retirement. This prospective cohort study provided novel results on the effects of leisure-time physical activity on health related functioning and changes in leisure-time physical activity after retirement. Although the benefits of moderate-intensity physical activity for health are well known these results suggest the importance of vigorous physical activity for subsequent health related functioning. Thus vigorous physical activity to enhance fitness should be given more emphasis from a public health perspective. In addition, physical activity should be encouraged among those who are about to retire.

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84 s.