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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.
651

Maternal Intrusiveness and Infant Affect: Transactional Relations and Effects on Toddler Internalizing Problems

January 2014 (has links)
abstract: Maternal intrusiveness is an important predictor of child mental health problems. Evidence links high levels of maternal intrusiveness to later infant negativity, and child internalizing problems. However, children also influence the manner in which parents interact with them. For example, infants that show more negative emotionality elicit less positive parenting in their caregivers. Infant affect is also associated with later child internalizing difficulties. Although previous research has demonstrated that maternal intrusiveness is related to infant affect and child internalizing symptomatology, and that infant affect is a predictor of internalizing problems and parenting, no studies have looked at the transactional relations between early maternal intrusiveness and infant affect, and whether these relations in infancy predict later childhood internalizing symptomatology. The present study investigates young children's risk for internalizing problems as a function of the interplay between maternal intrusiveness and infant affect during the early infancy period in a low-income, Mexican-American sample. Participants included 323 Mexican-American women and their infants. Data were collected when the infants were 12, 18, 24, and 52 weeks old. Mothers were asked to interact with their infants in semi-structured tasks, and mother and infant behaviors were coded at 12, 18, and 24 weeks. Maternal intrusiveness was globally rated, and duration of infant negative- and positive affect was recorded. Mother reports of child Internalizing symptomatology were obtained at 52 weeks. Findings suggest that there are transactional relations between early maternal intrusiveness and infant negative affect, while the relations between infant positive affect and maternal intrusiveness are unidirectional, in that infant positivity influences parenting but not vice versa. Further, findings also imply that neither maternal intrusiveness, nor infant affect, influence later toddler internalizing symptomatology. Identifying risk processes in a Mexican-American sample adds to our understanding of emerging infant difficulties in this population, and may have implications for early interventions. / Dissertation/Thesis / Masters Thesis Psychology 2014
652

Robustness of Social-ecological System Under Global Change: Insights from Community Irrigation and Forestry Systems

January 2015 (has links)
abstract: Social-ecological systems (SES) are replete with hard and soft human-made components (or infrastructures) that are consciously-designed to perform specific functions valued by humans. How these infrastructures mediate human-environment interactions is thus a key determinant of many sustainability problems in present-day SES. This dissertation examines the question of how some of the designed aspects of physical and social infrastructures influence the robustness of SES under global change. Due to the fragility of rural livelihood systems, locally-managed common-pool resource systems that depend on infrastructure, such as irrigated agriculture and community forestry, are of particular importance to address this sustainability question. This dissertation presents three studies that explored the robustness of communal irrigation and forestry systems to economic or environmental shocks. The first study examined how the design of irrigation infrastructure affects the robustness of system performance to an economic shock. Using a stylized dynamic model of an irrigation system as a testing ground, this study shows that changes in infrastructure design can induce fundamental changes in qualitative system behavior (i.e., regime shifts) as well as altered robustness characteristics. The second study explored how connectedness among social units (a kind of social infrastructure) influenced the post-failure transformations of large-N forest commons under economic globalization. Using inferential statistics, the second study argues that some attributes of the social connectedness that helped system robustness in the past made the system more vulnerable to undesirable transformations in the current era. The third study explored the question of how to guide adaptive management of SES for more robustness under uncertainty. This study used an existing laboratory behavioral experiment in which human-subjects tackle a decision problem on collective management of an irrigation system under environmental uncertainty. The contents of group communication and the decisions of individuals were analyzed to understand how configurations of learning-by-doing and other adaptability-related conditions may be causally linked to robustness under environmental uncertainty. The results show that robust systems are characterized by two conditions: active learning-by-doing through outer-loop processes, i.e., frequent updating of shared assumptions or goals that underlie specific group strategies, and frequent monitoring and reflection of past outcomes. / Dissertation/Thesis / Doctoral Dissertation Sustainability 2015
653

Combinatorial algorithms on partially ordered sets

Koda, Yasunori 29 June 2018 (has links)
The main results of this dissertation are various algorithms related to partially ordered sets. The dissertation basically consists of two parts. The first part treats algorithms that generate ideals of partially ordered sets. The second part concerns the generation of partially ordered sets themselves. First, we present two algorithms for listing ideals of a forest poset. These algorithms generate ideals in a Gray Code manner, that is, consecutive ideals differ by exactly one element. Both algorithms use storage O(n), where n is the number of elements in the poset. The first algorithm traverses, at each phase, the current ideal being listed and runs in time O(nN), where N is the number of ideals of the poset. The second algorithm mimics the first but eliminates the traversal and runs in time O(N). This algorithm has the property that the amount of computation between successive ideals is O(1). Secondly, we give orderly algorithms for constructing acyclic digraphs, acyclic transitive digraphs, finite topologies and finite topologies and finite lattices. For the first time we show that the number of finite lattices on 11, 12, and 13 elements are 37622, 262775, and 2018442, respectively, and the number of finite topologies on 8 and 9 elements are 35979 and 363083, respectively. We also describe orderly algorithms for generating k-colored graphs. We present, in particular, an algorithm for generating connected bicolorable graphs. We also prove some properties of a canonic matrix which might be generally useful for improving the efficiency of orderly algorithms. / Graduate
654

Surveys in Software Engineering : A Systematic Literature Review and Interview Study

Reddy, Sri Sai Vijay Raj, Nekkanti, Harini January 2016 (has links)
Context: The need for empirical investigations in software engineering domain is growing immensely. Many researchers nowadays, conduct and validate their study using empirical evidences. Survey is one such empirical investigation method which enables researchers to collect data from the large population. Main aim of the survey is to generalize the findings. Many problems are faced by the researchers in the survey process. Survey outcomes also depend upon variables like sample size, response rate and analysis techniques. Hence there is need for the literature addressing all the possible problems faced and also the impact of survey variables on outcomes. Objectives: Firstly, to identify the common problems faced by the researchers from the existing literature and also analyze the impact of the survey variables. Secondly to collect the experiences of software engineering researchers regarding the problems faced and the survey variables. Finally come up with a checklist of all the problems and mitigation strategies along with the information about the impact of survey variables. Methods: Initially a systematic literature review was conducted, to identify the existing problems in the literature and to know the effect of response rate, sample size, analysis techniques on survey outcomes. Then systematic literature review results were validated by conducting semi-structured, faceto-face interviews with software engineering researchers. Results: We were successful in providing a checklist of problems along with their mitigation strategies. The survey variables dependency on type of research, researcher’s choices limited us from further analyzing their impact on survey outcomes. The face-to-face interviews with software engineering researchers provided validations to our research results. Conclusions: This research gave us deeper insights into the survey methodology. It helped us to explore the differences that exists between the state of art and state of practice towards problem mitigation in survey process.
655

Algoritmos de aproximação para problemas de empacotamento em faixa com restrições de descarregamento / Approximation algorithms for the strip packing problem with unloading constraints

Silveira, Jefferson Luiz Moisés da, 1986- 18 August 2018 (has links)
Orientadores: Eduardo Candido Xavier, Flávio Keidi Miyazawa / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Computação / Made available in DSpace on 2018-08-18T03:33:12Z (GMT). No. of bitstreams: 1 Silveira_JeffersonLuizMoisesda_M.pdf: 1516196 bytes, checksum: b3f9127c1017ef29bf9c429bb93e1a0c (MD5) Previous issue date: 2011 / Resumo: Neste trabalho estudamos problemas de empacotamento com restrições de descarregamento considerados NP-difíceis. Estes problemas possuem aplicações nas áreas de logística e roteamento. Assumindo a hipótese de que P ? NP, sabemos que não existem algoritmos eficientes para resolver tais problemas. Uma das abordagens consideradas para tratar tais problemas é a de algoritmos de aproximação, que são algoritmos eficientes (complexidade de tempo polinomial) e que geram soluções com garantia de qualidade. Estudamos técnicas para o desenvolvimento de algoritmos aproximados e também alguns algoritmos para problemas de empacotamento online que podem ser utilizados na resolução do problema estudado. Propomos também algumas heurísticas para o problema e, além disto, provamos que duas destas heurísticas possuem garantias de aproximação com fatores constantes. Realizamos testes computacionais com estes algoritmos propostos. Dentre estes, a heurística GRASP foi a que obteve melhores resultados para as instâncias de teste consideradas / Abstract: In this work we study some NP-hard packing problems with unloading constraints. These problems have applications in logistics and routing problems. Assuming P ? NP, there are no efficient algorithms to solve these problems. On way to deal with these problems is using approximation algorithms, that are efficient algorithms (polynomial time complexity) that produce solutions with quality guarantee. We study techniques used in the development of approximation algorithms and some algorithms for online packing problems which can be used to solve the considered problem. We propose some heuristics for the problem and prove that two of them have constant approximation guarantees. We also perform computational tests with the proposed algorithms. Among them, the GRASP heuristic achieved the best results on the considered instances / Mestrado / Teoria da Computação / Mestre em Ciência da Computação
656

The new spectral Adomian decomposition method and its higher order based iterative schemes for solving highly nonlinear two-point boundary value problems

Mdziniso, Madoda Majahonkhe 01 July 2014 (has links)
M.Sc. (Applied Mathematics) / A comparison between the recently developed spectral relaxation method (SRM) and the spectral local linearisation method (SLLM) is done for the first time in this work. Both spectral hybrid methods are employed in finding the solution to the non isothermal mass and heat balance model of a catalytic pellet boundary value problem (BVP) with finite mass and heat transfer resistance, which is a coupled system of singular nonlinear ordinary differential equations (ODEs). The SRM and the SLLM are applied, for the first time, to solve a problem with singularities. The solution by the SRM and the SLLM are validated against the results by bvp4c, a well known matlab built-in procedure for solving BVPs. Tables and graphs are used to show the comparison. The SRM and the SLLM are exceptionally accurate with the SLLM being the fastest to converge to the correct solution. We then construct a new spectral hybrid method which we named the spectral Adomian decomposition method (SADM). The SADM is used concurrently with the standard Adomian decomposition method (ADM) to solve well known models arising in fluid mechanics. These problems are the magneto hydrodynamic (MHD) Jeffery-Hamel flow model and the Darcy-Brinkman- Forchheimer momentum equations. The validity of the results by the SADM and ADM are verified by the exact solution and bvp4c solution where applicable. A simple alteration of the SADM is made to improve the performance.
657

A Periodic Location Routing Problem for Collaborative Recycling

Hemmelmayr, Vera, Smilowitz, Karen, de la Torre, Luis January 2017 (has links) (PDF)
Motivated by collaborative recycling efforts for non-profit agencies, we study a variant of the periodic location routing problem, in which one decides the set of open depots from the customer set, the capacity of open depots, and the visit frequency to nodes, in an effort to design networks for collaborative pickup activities. We formulate this problem, highlighting the challenges introduced by these decisions. We examine the relative dfficulty introduced with each decision through exact solutions and a heuristic approach which can incorporate extensions of model constraints and solve larger instances. The work is motivated by a project with a network of hunger relief agencies (e.g., food pantries, soup kitchens and shelters) focusing on collaborative approaches to address their cardboard recycling challenges collectively. We present a case study based on data from the network. In this novel setting, we evaluate collaboration in terms of participation levels and cost impact. These insights can be generalized to other networks of organizations that may consider pooling resources.
658

Knowing what I know now : black women talk about violence inside and outside the home

Kanyeredzi, Ava January 2014 (has links)
There is a notable gap in empirical studies on Black women’s lived experiences in the UK in general and of violence in particular. This thesis explores lived experiences of violence and abuse for nine African and Caribbean heritage women, including seeking help and receiving support, legacies for the body and encounters in public spaces that leave feelings of discomfort. Fifteen participants were interviewed in total: six formed a sample of experts who work in violence support services, research and health services; and nine victim-survivors participated in a two or three stage life history interview process. The expert participants were given three case studies prior to taking part in semi-structured interviews to explore issues for African and Caribbean heritage women. During life history interviews research participants were invited to bring along personal photographs to assist with speaking about past experiences of violence and abuse, drew maps of their routes to seeking help, annotated diagrams of how they have related to their bodies over the years and produced photographs of spaces, places and objects of current importance to them. The thesis mapped ways in women’s potential for participation in social life was delimited by violence and abuse, how their survival was premised on their skill in managing embodied burdens and through daily acts of self-renewal. The contribution to knowledge of this thesis are through the conceptual terms: ‘felt intensities‘; ‘a continuum of oppression’; ‘liminal displacement’; ‘a nugatory self’; ‘racialised gendered shame’; and ‘exhausting liminal rumination’ that describe the embodied burdens carried by African and Caribbean heritage women as knowers and to suggest meeting their needs within the everyday spaces they inhabit. Further explorations are required into the intersectional features of women’s lives to explore whether African and Caribbean heritage women have voice and visibility in policy, whether and how their needs are met and for this to influence the commissioning of services.
659

'Spaces to speak' of sour milk : exploring African-Caribbean-British women's activism and agency on childhood sexual abuse from the 1980s to the present day

Wilson, Joanne January 2016 (has links)
The aim of this research study is to add the voices of African- Caribbean British female victim-survivors of childhood sexual abuse (CSA) to existing knowledge(s) on childhood sexual victimization. In so doing the study will examine whether racialisation, racism and cultural identity and cultural factors have had any bearing on African Caribbean British women’s 'space to speak' of childhood sexual abuse. The study also explores Black British feminist activism on CSA from the late 1970s- mid 1980s in order to further explore the issue of spaces to speak. The thesis presents findings from 5 in-depth interviews with Black British feminists (Experts); a partial content analysis of British feminist periodicals from 1980s onward; 7 in-depth interviews with African-Caribbean British victim-survivors of CSA and a survey examining Black, Asian and Minority, Ethnic service provision (BAME) in 13 Rape Crisis Centre’s in England and Scotland.
660

Identifying Solutions for  Customer – Supplier Communication Problems in  Agile Software Projects

Truszczynski, Mateusz January 2016 (has links)
Context. There are several methods of developing software in a systematic, engineering way. One of them are traditional methods such as waterfall. Nowadays, more common are becoming agile methodologies. Agile aims at addressing and improving a communication in software projects. However, customer - supplier communication in software projects still causes many difficulties. Objectives. In this study I wanted to identify basic customer – supplier communication problems that agile practitioners encounter in agile software projects. I also wanted to provide basic guidelines based on identified, prioritized problems and identified, prioritized solutions. Methods. Using recently published journal articles and conference proceedings  I identify customer – supplier communication problems that agile practitioners encounter in agile software projects. In order to identify solutions, and also prioritize the identified problems I used a survey. Then, based on analysis of results of the survey foreseen guidelines were synthesized.  Results. Literature study resulted in the identification of eight customer – supplier communication problems that agile practitioners encounter in agile software projects. The survey provided critical weighted evaluation of the problems and also suggested solutions to the problems. The obtained weighted results were used to develop the basic guidelines together with suggested solutions to each of them. Conclusions. The research was designed to help agile practitioners in their communication with a customer. The obtained results provide basic and starting guidelines that are based on the experience of the agile practitioners. That can be further extended based on future local and individual experience of agile practitioners.

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