On non-fragility of controllers for time delay systems: A numerical approach

In this paper an explicit numerical procedure is proposed to determine the non-fragility of parameters of controllers used to stabilize a class of time delay systems. The proposed procedure finds the largest possible circle inscribed in a stability subregion delimited by a simple closed curve in the plane of the controller parameters. The center of this circle is declared to be the controller’s least fragile parameters. The obtained theoretical results are applied and compared with some of the most relevant examples found in the literature. This illustrates that the proposed procedure improves previous results found in the literature so far.     

Stimulators and barriers towards social innovations in public libraries: Qualitative research study

Public libraries have a huge potential to be creators and facilitators of social innovation in communities and society. Qualitative research based on interviews with 27 librarians showed that social innovation in libraries can take the form of educational and cultural activities, leisure and networking activities and social support services. The main goal of the research was to find out what factors support and make these innovations difficult in public libraries. A four-layer model of barriers and stimulators for social innovation is presented, which includes structural, local, organizational and personnel levels. The model could serve to inform librarians, their stakeholders and governments about all levels of barriers and stimulators connected to innovation of library services and social re-positioning of public libraries in the future.     

Improving Chilean In-service Elementary Teachers’ Understanding of Nature of Science Using Self-contained NOS and Content-Embedded Mini-Courses

Understanding nature of science (NOS) is considered critical to the development of students’ scientific literacy. However, various studies have shown that a large number of elementary and secondary science teachers do not possess an adequate understanding of NOS. This study investigated how elementary teachers’ understanding of NOS was impacted through a 1-year professional development program in Chile that included NOS instruction as a theme throughout two types of mini-courses in the program. Twelve teachers attended a 1-year development program focused on improving teacher content knowledge and included the instruction of NOS embedded in two self-contained NOS mini-courses (36 h) and two lessons (3 h each) within five science content mini-courses (30 h). The Views of NOS (version D+) questionnaire and interviews were used to assess teachers’ understanding of NOS at the beginning (January) and end of the program (December). Elementary teachers’ understanding of the creative, inferential, and tentative aspect of NOS showed improvement. According to the teachers’ perceptions, the most significant activities for improving their NOS understanding were decontextualized activities in both types of mini-courses (self-contained NOS and science content mini-courses). The implications for professional development programs are also discussed.     

Listening to Students: Examining Underlying Mechanisms That Contribute to the AVID Program's Effectiveness

This study used a mixed-methods approach to examine the effects of the Advancement Via Individual Determination (AVID) program from the student perspective, specifically focusing on factors associated with student resilience. The AVID program aims to close the achievement gap among predominantly minority and low-income students without a family history of college attendance. Qualitative focus groups were conducted to better understand student perceptions of the program and quantitative survey results were used to compare scores on measures of school support, school engagement, and resilience among AVID and non-AVID students. Both qualitative and quantitative results provided evidence suggesting that the AVID program improved school support and engagement, as well as in the development of individual resilience factors, such as self-awareness, problem-solving ability, and self-esteem. Qualitative results also highlight the importance of providing consistency for students in the learning environment. Future directions and recommendations are provided.     

Der Abbau von Bildungsbenachteiligung durch Kindertagesbetreuung für unter 3-Jährige – zwischen Wunsch und Wirklichkeit

Based on the assumption that children can benefit from early childhood education, the present paper investigates if the admission to day care and the selection of the type of day care (child care centers and home day care) is socially selective. In doing so, the paper analyzes how the socioeconomic and immigrant background of families influences which type of day care is used. For children under the age of three, the social background of families does influence if a child receives day care, but this influences diminishes the older the children get. The type of day care (child care centers and home day care) did not differ according to social background. The paper closes with a discussion of the challenges and potentials for development of educating children under the age of three.     

Latino High School Students’ Perceptions of Caring: Keys to Success

This mixed methods investigation specifically examined Latino high school adolescents’ perceptions of teacher behaviors that demonstrate caring. A chi-square test was conducted to analyze the frequency of responses, and focus group interviews were conducted to expand on the results. The data indicated that although Latino male students were as likely to perceive the same behaviors Latina female students perceived as important or very important, a higher percentage of female students rated the same items as important. This investigation situates Latino high school adolescents’ voices as a pivotal agent to inform about the critical nature of caring for all students.     

Nonuniform Fuchsian codes for noisy channels

We develop a new transmission scheme for additive white Gaussian noisy (AWGN) channels based on Fuchsian groups from rational quaternion algebras. The structure of the proposed Fuchsian codes is nonlinear and nonuniform, hence conventional decoding methods based on linearity and symmetry do not apply. Previously, only brute force decoding methods with complexity that is linear in the code size exist for general nonuniform codes. However, the properly discontinuous character of the action of the Fuchsian groups on the complex upper half-plane translates into decoding complexity that is logarithmic in the code size via a recently introduced point reduction algorithm.     

Applying the technology acceptance model to a Spanish City Hall

This paper examines the relative importance and significance of the four technology enablers introduced by Davis (1989) in the technology acceptance model (TAM) (perceived ease of use, perceived usefulness, attitude towards using and behavioural intention) for use on four different levels of citizen engagement in e-government (null, publish, interact and transact). An extended technology acceptance model (TAM) is developed to test citizen engagement towards online e-government services from a sample of 307 citizens who used the benefits advisor tool within a Spanish City Hall. Although the proposed model follows TAM and explains the intention towards the actual use of e-government by postulating four direct determinants, “A, PU, PEOU and BI” have been considered as parallel processes, meaning that each can have separate influence in different levels of citizen engagement. To achieve this goal, a multinomial logistic regression is developed and tested to confirm the explanatory power of the four technology enablers on the four different levels of e-government. Our findings further suggest that in order to implement e-government, some of the enablers matter more than others to move from one level of citizen engagement to another. The main contribution of the paper is to question the use of existing models which seek to represent the relationship between technology enablers and the adoption of e-government services without considering their impacts on citizens’ engagement. The implications of the findings are discussed and useful insights are provided in relation to policy recommendations geared to create appropriate conditions to build citizens’ engagement intent of use of e-government services.     

Advances in three-dimensional rapid prototyping of microfluidic devices for biological applications

The capability of 3D printing technologies for direct production of complex 3D structures in a single step has recently attracted an ever increasing interest within the field of microfluidics. Recently, ultrafast lasers have also allowed developing new methods for production of internal microfluidic channels within the bulk of glass and polymer materials by direct internal 3D laser writing. This review critically summarizes the latest advances in the production of microfluidic 3D structures by using 3D printing technologies and direct internal 3D laser writing fabrication methods. Current applications of these rapid prototyped microfluidic platforms in biology will be also discussed. These include imaging of cells and living organisms, electrochemical detection of viruses and neurotransmitters, and studies in drug transport and induced-release of adenosine triphosphate from erythrocytes.