Stream Processing using Grammars and Regular Expressions

In this dissertation we study regular expression based parsing and the use of grammatical specifications for the synthesis of fast, streaming string-processing programs. In the first part we develop two linear-time algorithms for regular expression based parsing with Perl-style greedy disambiguation. The first algorithm operates in two passes in a semi-streaming fashion, using a constant amount of working memory and an auxiliary tape storage which is written in the first pass and consumed by the second. The second algorithm is a single-pass and optimally streaming algorithm which outputs as much of the parse tree as is semantically possible based on the input prefix read so far, and resorts to buffering as many symbols as is required to resolve the next choice. Optimality is obtained by performing a PSPACE-complete pre-analysis on the regular expression. In the second part we present Kleenex, a language for expressing high-performance streaming string processing programs as regular grammars with embedded semantic actions, and its compilation to streaming string transducers with worst-case linear-time performance. Its underlying theory is based on transducer decomposition into oracle and action machines, and a finite-state specialization of the streaming parsing algorithm presented in the first part. In the second part we also develop a new linear-time streaming parsing algorithm for parsing expression grammars (PEG) which generalizes the regular grammars of Kleenex. The algorithm is based on a bottom-up tabulation algorithm reformulated using least fixed points and evaluated using an instance of the chaotic iteration scheme by Cousot and Cousot

Optimally Streaming Greedy Regular Expression Parsing

Abstract. We study the problem of streaming regular expression parsing: Given a regular expression and an input stream of symbols, how to output a serialized syntax tree representation as an output stream during input stream processing. We show that optimally streaming regular expression parsing, outputting bits of the output as early as is semantically possible for any regular expression of size m and any input string of length n, can be performed in time O(2 m log m + mn) on a unit-cost random-access machine. This is for the wide-spread greedy disambiguation strategy for choosing parse trees of grammatically ambiguous regular expressions. In particular, for a fixed regular expression, the algorithm's run-time scales linearly with the input string length. The exponential is due to the need for preprocessing the regular expression to analyze state coverage of its associated NFA, a PSPACE-hard problem, and tabulating all reachable ordered sets of NFA-states. Previous regular expression parsing algorithms operate in multiple phases, always requiring processing or storing the whole input string before outputting the first bit of output, not only for those regular expressions and input prefixes where reading to the end of the input is strictly necessary

A European research agenda for somatic symptom disorders, bodily distress disorders, and functional disorders: Results of an estimate-talk-estimate delphi expert study

Background: Somatic Symptom Disorders (SSD), Bodily Distress Disorders (BDD) and functional disorders (FD) are associated with high medical and societal costs and pose a substantial challenge to the population and health policy of Europe. To meet this challenge, a specific research agenda is needed as one of the cornerstones of sustainable mental health research and health policy for SSD, BDD, and FD in Europe. Aim: To identify the main challenges and research priorities concerning SSD, BDD, and FD from a European perspective. Methods: Delphi study conducted from July 2016 until October 2017 in 3 rounds with 3 workshop meetings and 3 online surveys, involving 75 experts and 21 European countries. EURONET-SOMA and the European Association of Psychosomatic Medicine (EAPM) hosted the meetings. Results: Eight research priorities were identified: (1) Assessment of diagnostic profiles relevant to course and treatment outcome. (2) Development and evaluation of new, effective interventions. (3) Validation studies on questionnaires or semi-structured interviews that assess chronic medical conditions in this context. (4) Research into patients preferences for diagnosis and treatment. (5) Development of new methodologic designs to identify and explore mediators and moderators of clinical course and treatment outcomes (6). Translational research exploring how psychological and somatic symptoms develop from somatic conditions and biological and behavioral pathogenic factors. (7) Development of new, effective interventions to personalize treatment. (8) Implementation studies of treatment interventions in different settings, such as primary care, occupational care, general hospital and specialty mental health settings. The general public and policymakers will benefit from the development of new, effective, personalized interventions for SSD, BDD, and FD, that will be enhanced by translational research, as well as from the outcomes of research into patient involvement, GP-patient communication, consultation-liaison models and implementation. Conclusion: Funding for this research agenda, targeting these challenges in coordinated research networks such as EURONET-SOMA and EAPM, and systematically allocating resources by policymakers to this critical area in mental and physical well-being is urgently needed to improve efficacy and impact for diagnosis and treatment of SSD, BDD, and FD across Europe

Cognitive Behavioral Stress Management Training for Nursing Students

The overall purpose of this thesis is to examine a stress management intervention developed for nursing students. The thesis comprises three studies (Study I-III) based on empirical data from a sample of nursing students. The specific aim in the first study (Paper I) was to investigate the feasibility and acceptability of the stress management intervention. The results in the first study suggested that the feasibility of conducting a full-scale evaluation was confirmed for recruitment, acceptability, data collection, and adherence to the intervention. However, difficulties relating to homework were also identified. In the second study (Paper II), the specific aim was to investigate the participants’ experiences of participating in the stress management intervention. Findings indicate that participants developed new adaptive coping strategies, which were attributed to the intervention. The participants expressed that they had increased their ability to reflect which led to increased insight and self-reflection. Findings emphasize the importance of both theoretical and structural aspects when planning a stress management training intervention. A group format delivery in combination with a multi-component cognitive behavioral intervention can be interrelated elements for positive stress-related changes. The third study (Paper III), aimed at investigating preliminary psychological effects regarding self-esteem, self-efficacy and stress management competence. In the third study, the results showed that perceived stress-management competency was improved and had withstanding effects one year later when compared with a control group. Self-esteem and self-efficacy, both psychological resources, increase over time after the intervention.  In summary, this dissertation provides an insight into the challenges and the complexities of developing and implementing a stress management intervention in a nurse education context.The overall purpose of this thesis is to examine a new stress management intervention developed for nursing students. The thesis includes three studies. The aim in the first study was to investigate the feasibility and acceptability of the stress management intervention. The analysis suggested that the feasibility of conducting a full-scale evaluation was confirmed for recruitment, acceptability, data collection, and adherence to the intervention. However, difficulties were also identified. In the second study the aim was to investigate the participants’ experiences from participating in the intervention. The findings indicate that participants developed new and more adaptive coping strategies. Findings emphasize the importance of both theoretical and structural aspects when planning a stress management training intervention. The third study aimed at investigating preliminary psychological effects regarding self-esteem, self-efficacy and stress management competence. Perceived stress management competency was improved and had withstanding effects one year later when compared to a control group. Self-esteem and self-efficacy, both psychological resources, also increased over time after the training program. In summary, this thesis provides insight and knowledge into the challenges and the complexities of developing and implementing a stress management intervention in a nurse education context.

A feasibility study of a cognitive behavioral based stress management intervention for nursing students : results, challenges, and implications for research and practice

Background Stress related psychological problems are growing in nursing education and constitute an essential challenge for educators. This makes research about strategies and interventions to meet these problems important. Stress management interventions need to be tested for feasibility and acceptability, before conducting large scale RCTs. The objective of our study was to assess the feasibility and acceptability of a newly developed cognitive behavioral stress management intervention for nursing students. Methods Data were collected using a combination of standardized measurements and newly created questionnaires in combination with qualitative data. Our data included recruitment capability, sample characteristics, intervention acceptability and preliminary evaluation of participant psychological changes. Results Findings suggested that the feasibility of conducting a full-scale evaluation was confirmed for intervention acceptability, data collection procedures, and adherence. However, difficulties relating to recruitment capability and homework were identified. All aspects taken together, the intervention was found feasible and acceptable to nursing students, and thus a potential stress management intervention for the nurse education context. Conclusions Overall, this study provides an insight into the challenges and complexities of developing and evaluating a new brief cognitive behavioral based stress management training intervention in a nurse education setting.Publicerades som manuscript i avhandlingen med titel: Cognitive Behavioral Stress Management Training for Nursing Students </p