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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
71

非線性微分方程式 t^2u"=u^p / On the nonlinear differential equation t^2u"=u^p

姚信宇 Unknown Date (has links)
回顧一個重要的非線性二階方程式 d/dt(t^p(du/dt))+(-)t^(sigma)u^n=0, 這個方程式有許多有趣的物理應用,以Emden方程式的形式發生在天體物理學中;也以Fermi-Thomas方程式的形式出現在原子物理內。對於此類型的非線性方程式可以用來更頻繁且深入的探討數學物理,雖然目前仍存在著些許不確定性,不過如果在未來能有更全面的了解,這將有助於用來決定物理解的性質。 在這篇論文當中,我們討論微分方程式 t^2u"=u^p,p屬於N-{1}, 其正解的性質。這個方程式是著名的 Emden-Fowler 方程式的一種特殊情形, 我們可以得到其解的一些有趣的現象及結果。 / Recall the important nonlinear second-order equation d/dt(t^p(du/dt))+(-)t^(sigma)u^n=0, this equation has several interesting physical applications, occurring in astrophysics in the form of the Emden equation and in atomic physics in the form of the Fermi-Thomas equation. These seems a little doubt that nonlinear equations of this type would enter with greater frequency into mathematical physics, were it more widely known with what ease the properties of the physical solutions can be determined. In this paper we discuss the property of positive solution of the ordinary differential equation t^2u"=u^p, p belongs to N-{1}, this equation is a special case of the well-known Emden-Fowler equation, we obtain some interesting phenomena and resulits for solutions.
72

Ecological comparison of three closely related species from \kur{Myosotis palustris} group / Ecological comparison of three closely related species from \kur{Myosotis palustris} group

KOUTECKÁ, Eva January 2011 (has links)
The study is focused on comparative ecology of three closely related species from Myosotis palustris group. Importance of various functional traits of individual species was evaluated experimentally in the greenhouse (germination experiments), in the pot experiment and in the reciprocal transplant field experiment. Germination, production of clonal structures and response to various environmental conditions (competition, moisture conditions, etc.) were studied. The experimental data are supplemented with an analysis of phytosociological relationships of the studied species.
73

The early adult life structure of urban black men

Segal, Robert Daniel 06 1900 (has links)
The purpose of this study is to provide a groundwork for the understanding of the psychosocial development of black South African men. This need stems from the limitation of current models of psychosocial development, which have a white, middleclass bias, and from the dearth of research relating to black psychosocial development in South Africa. Questions which have guided the present study include the following: What is the nature of the psychosocial development of black men? What are the main developmental tasks that they have to negotiate, especially in relation to family and career? How do sociocultural, political and economic factors influence development? How does the development of black South African men compare with other conceptualisations of adult development? Daniel Levinson's (1978) theory of the life structure was used as a framework to explore these questions. This involved a series of in depth qualitative interviews with eight men between the ages of 29 and 41, from diverse educational and socio-economic backgrounds. The grounded theory approach used to analyse the data involved the simultaneous process of data collection and data analysis. Similarities and differences in the men's evolving life structures were identified through a process of coding, or organising the data into categories and themes. The findings highlighted the importance of understanding the dialectical nature of development, the role of life events, and the significance of role strain across the life span of black South African adults. Discrimination, economic constraints, traditional values, and the sociopolitical context were found to have an impact on the important developmental tasks. The coping strategies employed to deal with external barriers had an especially influential impact on the men's evolving life structures. A model of psychosocial development was proposed which addresses these factors, and which is thus more relevant to the lives of black South African men, than stage models such as Levinson's. Important implications on a societal and theoretical level, and for the professional practice of psychology emerged. It is hoped that these findings will enrich developmental theory in psychology training programmes, and guide career and personal counselling in the South African context. / Psychology / D.Litt. et Phil. (Psychology)
74

Analýza nákladů stavebního objektu a jejich pokrytí / Cost analysis of the building and their coverage

Barchánková, Vendula January 2016 (has links)
The aim of this thesis is to introduce the given topic " Cost analysis of the building and their coverage" and to show an analyze of selected the life cycle phases on a specific example. The paper also solved ways of financing options especially financing via grants. At the end of work I deal with the recommendations of choosing a suitable grant title for the financing of new construction or reconstruction nursery schools.
75

Stereoselective synthesis and hormonal activity of novel dafachronic acids and naturally occurring steroids isolated from corals

Saini, Ratni, Boland, Sebastian, Kataeva, Olga, Schmidt, Arndt W., Kurzchalia, Teymuras V., Knölker, Hans-Joachim January 2012 (has links)
A stereoselective synthesis of (25S)-Δ1-, (25S)-Δ1,4-, (25S)-Δ1,7-, (25S)-Δ8(14)-, (25S)-Δ4,6,8(14)-dafachronic acid, methyl (25S)-Δ1,4-dafachronate and (25S)-5α-hydroxy-3,6-dioxocholest-7-en-26-oic acid is described. (25S)-Δ1,4-Dafachronic acid and its methyl ester are natural products isolated from corals and have been obtained by synthesis for the first time. (25S)-5α-Hydroxy-3,6-dioxocholest-7-en-26-oic acid represents a promising synthetic precursor for cytotoxic marine steroids. / Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.
76

Väggelement i trä : Prefab vs platsbyggt / Timber Frame Walls : Prefab vs site-built

Sidabutar, Marsingal, Kilic Marouf, Pervin January 2020 (has links)
Prefabricering av väggelement är en byggmetod under stark framväxt i byggandet av småhus de senaste decennierna. Kostnadseffektiviteten nämns ofta som ett skäl till att prefabricering av småhus har en sådan stor framväxt. Samtidigt har miljö- och klimatfrågan växt och då byggsektorn står för en stor del av Sveriges koldioxidutsläpp krävs det att byggsektorn ställer om till ett allt med hållbart byggande. Detta examensarbete har undersökt denna kostnadseffektivitet och hur och om en går att kombinera med ett hållbart byggande och sedan jämfört detta med platsbyggda väggar i trä. Underlag har tagits fram i samarbete med Skidstahus som producerar prefabricerade väggelement i fabriksmiljö och underlag från Derome Hus AB/ VarbergsHus vad berör småhus i lösvirke. En kostnadsjämförelse av de två byggmetoderna visar att de prefabricerade väggelement som Skidstahus framställer är mer kostnadseffektiva och det beror till stor del på att arbetstiden effektiviseras. Till viss del visar examensarbetet att materialanvändningen även resurs effektiviseras vid Skidstahus produktion och resulterar i mindre spill som därmed gynnar ett hållbart byggande. Andra viktiga aspekter för hållbarhet och livslängd såsom fukt och lufttäthet visar att prefabricerade väggar har utmaningar då skarvar och anslutningar måste vara väl utförda. Samtidigt innebär arbetet i fabriksmiljö att risken för fuktproblem minskar då det ger ett skydd för klimat och väder. Detta är medför även att byggarbetarna får en god och vältempererad arbetsmiljö. Däremot finns frågetecken kring hur byggande med prefabricerade väggelement påverkar miljön i form av transporter i förhållandet till platsbyggda väggar av lösvirke, då transporter till och från fabrik krävs. Utöver detta påverkar byggmetoden hur gestaltning och arkitektur utförs då ett platsbyggt hus i trä enklare går att utföra med valfri gestaltning. Analyserna visar sammanfattningsvis att användandet av prefabricerade väggelement i trä reducerar byggkostnader samtidigt som det kan bidra till ett hållbart byggande. Det krävs dock ytterligare studier för att jämföra den beräknade livslängden på prefabricerade väggar och platsbyggda. / Prefabrication of wood wall elements in construction of villas and terraced houses is a building method undergoing growth in recent decades. Cost efficiency is often cited as a reason why prefabrication has undergone such a large growth. At the same time, the issue of environmental impact and climate change has grown. As the construction sector accounts for a large part of Sweden's carbon dioxide emissions, the construction sector needs to become more sustainable. This thesis has examined this cost-effectiveness and if it is possible to combine with environmental sustainability. To examine this more thoroughly a comparison is made with in site-built timber-framed constructed walls. The thesis has been conducted in collaboration with Skidstahus, which produces prefabricated wall elements in a factory environment, especially for data collection. Information and data have also been collected from Varbergshus / Derome producing houses in site-built timber-framed building. A cost comparison of the building methods shows that the prefabricated wall elements manufactured by Skidstahus are more cost-effective, which can be linked to work efficiency. To some extent, the thesis also shows that material use can be optimized at Skidstahus production and therefore results in less waste, which thus reduces environmental impact. Other important factors for durability and accounted life span is the building method’s ability to handle migration of moisture and airtightness. The thesis shows that prefabricated walls have challenges, as joints and connections must be well designed. At the same time, factory production allows an environment which can reduce risk of migration of moisture as it provides protection for climate and weather impact. Another aspect is that it provides a good and well-tempered work environment for the construction worker. On the other hand, it is questionable whether the use of prefabricated wall elements affects the environment as it may increase the need of transportation in relation to on site-built timber-framed walls, as transport to and from the factory is required. In addition, the prefabricated method could influence how design and architecture is carried out while a wood house made from stick timber is more easily modified. In summary, the analysis show that the use of prefabricated wood wall elements reduces building costs while at the same time it can contribute to environmental sustainability. However, further studies are required to compare the estimated life span of the two compared building methods.
77

Zusammenspiel von Wohlbefinden und Lebenssinn in der Entwicklung zum Alter : eine praktish-theologische Studie / The interplay of wellbeing and meaning of life in the development to old age : a practical-theological study

Marti, Peter (Theologian) 02 1900 (has links)
German text / Gutes Altern gelingt selbst bei den zumeist günstigen äusseren Voraussetzungen in der Schweiz nicht allen Menschen. Die Frage stellt sich, unter welchen Bedingungen sowohl echtes Wohlbefinden im Alltag als auch Lebenssinn und -perspektive erreicht und erhalten werden können. Gelingt dies bekennenden Christen besser als nicht religiösen Menschen? Im Hinblick auf diese Fragestellung untersuchte die vorliegende Arbeit die bisherige gerontologische Forschung hauptsächlich in der Schweiz. Es wurde versucht, die Begriffe Wohlbefinden, Lebenssinn in Verbindung mit Religionsgerontologie anhand einzelner Exponenten zu definieren und das Zusammenspiel der Faktoren aufzuzeigen. In einer qualitativen empirischen Studie wurden gemäss der Grounded Theory zwölf Personen zwischen 50 und 80 Jahren (drittes Alter) mit zehn verschiedenen religiös/spirituellen Hintergründen mit Hilfe eines halbstrukturierten Leitfadens interviewt. Die Hauptthemen waren Wohlbefinden, Lebenssinn, Glaube/Spiritualität und Sterben/Tod. Der Zusammenhang zwischen alltäglichem Wohlbefinden und Lebenssinn bzw. -perspektive erwies sich als stark. Menschen mit einer persönlichen Gottesbeziehung schienen über mehr Ressourcen zu verfügen, nicht nur, um die eigene Endlichkeit zu akzeptieren oder schwierige Ereignisse im Leben zu meistern, sondern auch, um ihren letzten Lebenssinn in Gott zu erkennen, also ausserhalb von sich selbst. So waren sie besser befähigt, in ihrem Lebenslauf Erreichtes wieder abzugeben. Dieser Lebensstil benötigt Einübung, er kann jedoch auch gezielt gefördert werden. Aufgrund der Erkenntnisse konnten eine Reihe von Aufgaben formuliert werden, die den älteren Menschen Anweisung geben, wie sie diesen Lebensstil konkret in ihrem Alltag umsetzen könnten. Zudem scheint christliche Gemeinde ein geeigneter Rahmen darzustellen, wenn sie für das dritte Alter interdisziplinäre Lernangebote aus den Bereichen Medizin, Psychologie, Soziologie und Theologie wie auch die Möglichkeit persönlicher Seelsorge bereitstellt. Der ältere Mensch wird dadurch frei, sich generativ für andere einzusetzen und für sie da zu sein, innerhalb der christlichen Gemeinde oder auch ausserhalb als Teil der Gesellschaft. Somit wird dem neutestamentlichen Gebot der Nächstenliebe nachgekommen, Solidarität anderen gegenüber wird gelebt. Stärkeres Sinnempfinden und höheres Wohlbefinden sind geschenkte Nebenprodukte, die zu einem erfüllten Leben beitragen. / In Switzerland ageing is not necessarily unproblematic, even in the most favorable conditions. The question to answer is on what conditions in everday life a high level of wellbeing as well as meaning and perspective of life can be attained and preserved. Do professing Christians succeed better than non-religious people? The present study examined the results of current gerontological resarch in this respect, primarily in Switzerland. It attempted to define the terms of wellbeing, meaning of life in connection with religious gerontology with specific criteria and to show up the interaction of their several components. In a qualitative empirical study, according to the Grounded Theory, twelve persons between fifty and eighty years of age with ten different religious/spiritual backgrounds were interviewed with the aid of a semistructured interview guide. The main topics were wellbeing, meaning of life, faith/spirituality and dying/death. The relationship between everyday wellbeing and meaning of life and life perspective proved to be strong. People with a personal relationship with God seemed to have more resources to accept not only their own mortality or to cope with negative events in life, but to recognize their ultimate meaning of life to be in God, which is outside themselves. In consequence they were better able to let go any of their own achievements. This lifestyle requires practise and promotion. On account of the results a number of tasks were formulated to guide the older people in their daily life in practicing this lifestyle. The Christian community seems to be a suitable framework to provide interdisciplinary learning opportunities for the third age in the fields of medicine, psychology, sociology and theology as well as the opportunity of personal counseling. In this way, the never-ending process of maturation of individual elderly people should be encouraged. They are free, according to their talents, to get themselves involved with other people, to have time for them, that is within the Christian community or outside, in society. Thus, the New Testament commandment to love one another can be complied with, and solidarity with others will truly be fact. A stronger sense of meaning and a higher grade of wellbeing will be welcome by-products, which will contribute to a fulfilled life. / Practical Theology / D. Th. (Practical Theology)
78

From crisis to awakening: an exploration of midlife experiences from a positive psychology perspective

Niehaus, Louisa 01 1900 (has links)
Text in English / The purpose of this study was to gain a richer understanding of midlife experiences. Midlife is stereotypically viewed as a crisis and is one of the least studied, most illdefined stages in life, yet it’s one of the most significant stages. The epistemological framework for this study is post modernism, which allows for this study to document the transitions from crisis at midlife, as seen through the lens of Positive Psychology. This study was exploratory in nature and applied a qualitative ethnographic methodology. Six participants were interviewed from an ethnographic perspective, in an endeavour to allow each participant accordant ontological breadth and flexibility within their respective social and ideological contexts. The researcher’s own social context also adding nuance to the interpretation of data. This interpretation allows for the inclusion of hope, wisdom, creativity, future mindedness, courage, spirituality, responsibility and perseverance. Thematic analysis of these participants’ narratives supports the psychological research which suggests that challenges are associated with midlife. Thematic analysis revealed challenges associated with midlife such as feelings of disillusionment, regret and dissatisfaction; feelings of loneliness, rejection and isolation as well as confusion about the way forward; seeking a meaningful existence and connection as well as achievement. Some participants, however, are in denial of the existence or their experience of midlife and associated challenges, whereas others describe midlife as a transition phase — a crossroads, a wake-up call and time for reassessment Although midlife can be a difficult transitional period, Positive Psychology can help individuals identify and build the necessary resources and coping strategies to prevent a transition turning into a crisis. It was shown that most participants in this research displayed a mindset and attitude open to a Positive Psychology paradigm to accumulate the necessary resources and coping strategies to prevent a midlife transition from becoming a midlife crisis. / Psychology / M.A. (Psychology)
79

Contextual effects on individual development of subjective well-being in the second half of life

Vogel, Nina 23 July 2016 (has links)
Die Psychologie der Lebensspanne und die Soziologie des Lebensverlaufs betonen die Bedeutung von Kontexten für den Erwerb individueller Fähigkeiten und die Entwicklung im Leben. In Übereinstimmung mit diesen konzeptionellen Annahmen zeigen Studien, dass verschiedene Kontexte die Entwicklung individueller Bereiche beeinflussen. Jedoch ist wenig darüber bekannt, wie kontextuelle Faktoren in der zweiten Lebenshälfte Wohlbefinden formen und wie Wohlbefinden in diesen Lebensphasen von sich schnell verändernden Kontexten beeinflusst wird. In dieser Dissertation werden unter Anwendung des Ökosystemischen Ansatzes von Bronfenbrenner drei Kontexte unterschiedlicher Proximität untersucht, in die die Entwicklung des individuellen Wohlbefindens eingebettet ist. Als erster Kontext wird die vielfältige Ökologie des Lebens und Sterbens in den ehemaligen Regionen Ost- und Westdeutschland herangezogen, um herauszufinden wie dieses Makrosystem Wohlbefinden in den letzten Lebensjahren gestaltet. Als zweiter Kontext wird die Bedeutung des Exosystems von Gesundheitseinrichtungen in Landkreisen (z.B. Anzahl stationärer Pflegereinrichtungen) auf Wohlbefindensverläufe am Lebensende beleuchtet. Als dritten Kontext untersuchen wir, wie das Mikrosystem sozialer Ökologien und Situationen momentanes, affektives Wohlbefinden gestaltet, sowie Altersunterschiede in diesen Assoziationen. Gemeinsam zeigen die drei Studien dieser Dissertation, dass Ökologien auf regionaler, dienstleistender und sozialer Kontextebene Entwicklung von Wohlbefinden in der zweiten Lebenshälfte beeinflussen. Diese Arbeit zeigt, dass Kontexte sowohl kognitives als auch affektives Wohlbefinden und innerhalb des letzteren sowohl Valenz und Aktivierung beeinflussen, und untersucht länger- und kurzfristige Kontext-Wohlbefindens-Assoziationen in späteren Lebensphasen. Die Ergebnisse liefern erste Vorschläge für Interventionen und veränderbare regionale Faktoren für die Erhaltung oder Verbesserung von Wohlbefinden. / Lifespan psychology and life course sociology have long acknowledged the role of context for individual functioning and development throughout life. Consistent with these conceptual notions, empirical studies show that various contextual factors influence development of individual-level outcomes. However, we know little about how contextual factors shape individual-level well-being and how well-being is influenced by fast changing contexts in the second half of life. Applying Bronfenbrenner’s model of human ecology as the overarching theoretical frame, this dissertation examines three sets of contexts that differ in the degree of proximity in which individual well-being and its development is embedded in. As a first context, the multifaceted ecology of living and dying in former regions of East and West Germany is used to investigate how the macrosystem shapes individual well-being in the last years of life. For a second context, the role of the exosystem of county-level health care features (e.g., number of inpatient care facilities) on late-life trajectories in well-being is examined. As a third context, we examine how the microsystem of social ecologies and situations influences momentary affective well-being and how these associations differ across age. Jointly, the three studies in this dissertation show that regional, service, and social ecologies profoundly shape development in well-being during the second half of life. To conclude, this dissertation shows that these contexts influence both cognitive and affective components of well-being, among the affective domain two facets (valence and arousal), and investigates long-term and short-term contextwell- being associations in later life phases. Results provide initial suggestions for interventions and malleable regional factors to maintain or improve well-being.
80

A longer working life for Australian women of the baby boom generation? � Women�s voices and the social policy implications of an ageing female workforce

Merkes, Monika, monika@melbpc.org.au January 2003 (has links)
With an increasing proportion of older people in the Australian population and increasing health and longevity, paid work after the age of 65 years may become an option or a necessity in the future. The focus of this research is on Australian women of the baby boom generation, their working futures, and the work-retirement decision. This is explored both from the viewpoint of women and from a social policy perspective. The research draws on Considine�s model of public policy, futures studies, and Beck�s concept of risk society. The research comprises three studies. Using focus group research, Study 1 explored the views of Australian women of the baby boom generation on work after the age of 65 years. Study 2 aimed to explore current thinking on the research topic in Australia and overseas. Computer-mediated communication involving an Internet website and four scenarios for the year 2020 were used for this study. Study 3 consists of the analysis of quantitative data from the Healthy Retirement Project, focusing on attitudes towards retirement, retirement plans, and the preferred and expected age of retirement. The importance of choice and a work � life balance emerged throughout the research. Women in high-status occupations were found to be more likely to be open to the option of continuing paid work beyond age 65 than women in low-status jobs. However, the women were equally likely to embrace future volunteering. The research findings suggest that policies for an ageing female workforce should be based on the values of inclusiveness, fairness, self-determination, and social justice, and address issues of workplace flexibility, equality in the workplace, recognition for unpaid community and caring work, opportunities for life-long learning, complexity and inequities of the superannuation system, and planning for retirement. Further, providing a guaranteed minimum income for all Australians should be explored as a viable alternative to the current social security system.

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