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Sample records for reflective electronic portfolio

  1. Fellows' Perceptions of a Mandatory Reflective Electronic Portfolio in a Geriatric Medicine Fellowship Program

    Science.gov (United States)

    Ruiz, Jorge G.; Qadri, Syeda S.; Karides, Marina; Castillo, Carmen; Milanez, Marcos; Roos, Bernard A.

    2009-01-01

    Electronic portfolios (ePortfolios) can be useful for evaluating and documenting mastery of competencies. We investigated geriatric medicine fellows' perceptions of an ePortfolio. We conducted surveys and focus groups followed by quantitative and qualitative data analysis. Our study revealed that fellows considered the ePortfolio acceptable and…

  2. Developing a sustainable electronic portfolio (ePortfolio) program that fosters reflective practice and incorporates CanMEDS competencies into the undergraduate medical curriculum.

    Science.gov (United States)

    Hall, Pippa; Byszewski, Anna; Sutherland, Stephanie; Stodel, Emma J

    2012-06-01

    The University of Ottawa (uOttawa) Faculty of Medicine in 2008 launched a revised undergraduate medical education (UGME) curriculum that was based on the seven CanMEDS roles (medical expert, communicator, collaborator, health advocate, manager, scholar, and professional) and added an eighth role of person to incorporate the dimension of mindfulness and personal well-being. In this article, the authors describe the development of an electronic Portfolio (ePortfolio) program that enables uOttawa medical students to document their activities and to demonstrate their development of competence in each of the eight roles. The ePortfolio program supports reflective practice, an important component of professional competence, and provides a means for addressing the "hidden curriculum." It is bilingual, mandatory, and spans the four years of UGME. It includes both an online component for students to document their personal development and for student-coach dialogue, as well as twice-yearly, small-group meetings in which students engage in reflective discussions and learn to give and receive feedback.The authors reflect on the challenges they faced in the development and implementation of the ePortfolio program and share the lessons they have learned along the way to a successful and sustainable program. These lessons include switching from a complex information technology system to a user-friendly, Web-based blog platform; rethinking orientation sessions to ensure that faculty and students understand the value of the ePortfolio program; soliciting student input to improve the program and increase student buy-in; and providing faculty development opportunities and recognition.

  3. Using Electronic Portfolios

    Science.gov (United States)

    Page, Deb

    2012-01-01

    The digitized collections of artifacts known as electronic portfolios are creating solutions to a variety of performance improvement needs in ways that are cost-effective and improve both individual and group learning and performance. When social media functionality is embedded in e-portfolios, the tools support collaboration, social learning,…

  4. Reflection during Portfolio-Based Conversations

    Science.gov (United States)

    Oosterbaan, Anne E.; van der Schaaf, Marieke F.; Baartman, Liesbeth K. J.; Stokking, Karel M.

    2010-01-01

    This study aims to explore the relationship between the occurrence of reflection (and non-reflection) and thinking activities (e.g., orientating, selecting, analysing) during portfolio-based conversations. Analysis of 21 transcripts of portfolio-based conversations revealed that 20% of the segments were made up of reflection (content reflection…

  5. A ubiquitous reflective e-portfolio architecture.

    Science.gov (United States)

    Forte, Marcos; de Souza, Wanderley L; da Silva, Roseli F; do Prado, Antonio F; Rodrigues, Jose F

    2013-11-01

    In nurse and in medicine courses, the use of reflective portfolios as a pedagogical tool is becoming a common practice; in the last years, this practice has gradually migrated from paper-based to electronic-based portfolios. Current approaches for reflective e-portfolios, however, do not widely operate at outdoor sites, where data networks are limited or nonexistent. Considering that many of the activities related to nurse and medicine courses relate to professional practices conducted in such conditions, these network shortcomings restrict the adoption of e-portfolios. The present study describes the requirements specification, design, implementation, and evaluation of the Ubiquitous Reflective E-Portfolio Architecture, a solution proposed to support the development of systems based on mobile and wired access for both online and offline operation. We have implemented a prototype named Professional Practice Module to evaluate the Ubiquitous Reflective E-Portfolio Architecture; the module was based on requirements observed during the professional practice, the paper-based portfolio in use, and related learning meetings in the Medicine Course of a Brazilian University. The evaluation of the system was carried out with a learning group of 2nd year students of the medicine course, who answered to extensive evaluation questionnaires. The prototype proved to be operational in the activities of the professional practice of the Medicine Course object of the study, including homework tasks, patient care, data sharing, and learning meetings. It also demonstrated to be versatile with respect to the availability of the computer network that, many times, was not accessible. Moreover, the students considered the module useful and easy to use, but pointed out difficulties about the keyboard and the display sizes of the netbook devices, and about their operational system. Lastly, most of the students declared preference for the electronic Professional Practice Module in internal

  6. Students' reflections in a portfolio pilot: highlighting professional issues.

    Science.gov (United States)

    Haffling, Ann-Christin; Beckman, Anders; Pahlmblad, Annika; Edgren, Gudrun

    2010-01-01

    Portfolios are highlighted as potential assessment tools for professional competence. Although students' self-reflections are considered to be central in the portfolio, the content of reflections in practice-based portfolios is seldom analysed. To investigate whether students' reflections include sufficient dimensions of professional competence, notwithstanding a standardized portfolio format, and to evaluate students' satisfaction with the portfolio. Thirty-five voluntary final-year medical students piloted a standardized portfolio in a general practice (GP) attachment at Lund University, Sweden. Students' portfolio reflections were based upon documentary evidence from practice, and aimed to demonstrate students' learning. The reflections were qualitatively analysed, using a framework approach. Students' evaluations of the portfolio were subjected to quantitative and qualitative analysis. Among professional issues, an integration of cognitive, affective and practical dimensions in clinical practice was provided by students' reflections. The findings suggested an emphasis on affective issues, particularly on self-awareness of feelings, attitudes and concerns. In addition, ethical problems, clinical reasoning strategies and future communication skills training were subjects of several reflective commentaries. Students' reflections on their consultation skills demonstrated their endeavour to achieve structure in the medical interview by negotiation of an agenda for the consultation, keeping the interview on track, and using internal summarizing. The importance of active listening and exploration of patient's perspective was also emphasized. In students' case summaries, illustrating characteristic attributes of GP, the dominating theme was 'patient-centred care', including the patient-doctor relationship, holistic modelling and longitudinal continuity. Students were satisfied with the portfolio, but improved instructions were needed. A standardized portfolio in a

  7. Student Chemical Engineering Reflective ePortfolios--ChE Student Perceptions of Learning from Reflective ePortfolio Creation

    Science.gov (United States)

    Cherrstrom, Catherine A.; Raisor, Cindy; Fowler, Debra

    2015-01-01

    Engineering educators and employers value and prioritize communication skills, but developing and assessing such skills in engineering programs is challenging. Reflective ePortfolios provide opportunities to enhance communication skills. The purpose of this three-­year qualitative case study was to investigate the use of reflective ePortfolios in…

  8. Acceptability of a reflective e-portfolio instituted in an orthodontic specialist programme: a pilot study.

    Science.gov (United States)

    Tonni, I; Oliver, R G

    2013-08-01

    The purpose of the study was to highlight students' and mentors' acceptability of a reflective e-portfolio instituted in a postgraduate orthodontic programme in the UK. A reflective e-portfolio was developed on the basis of principles provided by a literature search and was piloted for 2 months with six students and seven mentors. At the end of the experience, mentors' and students' acceptability of the e-portfolio with a reflective component was studied using questionnaires. The data were analysed using basic quantitative and qualitative methods. Students' response highlighted acceptability issues related to each aspect of the e-portfolio derived from the literature: relevance of the e-portfolio reflective part; time required for the process; support and mentoring; the implementation method; and the electronic medium. Mentors showed a more positive attitude towards the e-portfolio, expressing only some concerns about the time involved in using it. Furthermore, the analysis of the data highlighted some other acceptability matters: the specificity of the e-portfolio, the communication amongst students and the relationship between students and mentors. The future successful implementation of the reflective e-portfolio will depend on the productive management of the acceptability issues identified by students and mentors, in particular:(i)the specificity of the e-portfolio that would avoid its overlapping with other part of the programme;(ii)the increasing communication amongst students to improve their knowledge of the reflective writing process; and (iii)the development of a relationship between students and mentors helping to create the appropriate environment for reflection. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  9. Electronic portfolio motivational factors from students’ perspective: A qualitative study

    Directory of Open Access Journals (Sweden)

    Rokhsareh Mobarhan

    2015-06-01

    Full Text Available Electronic portfolio (e-Portfolio is known as an electronic learning record which collects the learning evidences, reflections and accomplishments. In fact, it tells the story of learning achievements. It is an important tool for students, lecturers, administrators and faculties to monitor the learning outcomes. Similarly to other technologies, e-Portfolio is also considered successful, if it is used by students continuously. Previous researches showed the importance of intrinsic and extrinsic motivations in using any technologies. However, lack of motivation has been a major concern for developing any successful online learning environments. The aim of this paper is to explain the e-Portfolio motivational factors from students’ perspective. Interviews are conducted with students from one university in Malaysia in order to get better understanding of the phenomena. The target interviewees are bachelor students chosen from different faculties. Based on the qualitative content analysis of the interviews, the motivational factors affecting the continuous use of e-portfolio are coded in eight themes and then they categorized in four main groups of individual, system, social and environmental characteristics. Finally they are classified into intrinsic or extrinsic motivations.

  10. Electronic portfolios in nursing education: a review of the literature.

    Science.gov (United States)

    Green, Janet; Wyllie, Aileen; Jackson, Debra

    2014-01-01

    As health professionals, nurses are responsible for staying abreast of current professional knowledge and managing their own career, professional growth and development, and ideally, practices to support these activities should start during their student years. Interest in electronic or eportfolios is gathering momentum as educationalists explore their potential as a strategy for fostering lifelong learning and enhancing on-going personal and professional development. In this paper, we present an overview of e-portfolios and their application to nurse education, highlighting potential benefits and considerations of useage. We argue that the e-portfolio can represent an authentic means of assessing cognitive, reflective and affective skills. Furthermore, the e-portfolio provides a means through which nurses can record and provide evidence of skills, achievements, experience, professional development and on-going learning, not only for themselves, but for the information and scrutiny of registration boards, employers, managers and peers. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

  11. Reflective portfolios support learning, personal growth and ...

    African Journals Online (AJOL)

    Conclusion. Portfolios are an under-utilised assessment and self-development tool in postgraduate training. They allow students to self-assess their attainment of personal learning needs, professional growth and competency achievement and provide faculty with useful feedback on curriculum content, educational activities ...

  12. The development of a reflective vascular training portfolio: Using a ...

    African Journals Online (AJOL)

    ... of formative assessment to certify candidates. Case-based self-reflection in postgraduate training may be used as an additional educational tool and incorporated into the curricula vitae of trainees. We describe the method used to assess a vascular case, based on a self-reflective training method (vascular case portfolio).

  13. Constructing a reflective portfolio tool: an action research on the student teachers' perceptions of their experiences

    OpenAIRE

    Zeki, Canan Perkan

    2010-01-01

    My interest into reflection and portfolio construction was developed during the 2005 Contexts for Teacher Education Module on the EdD course at the Nottingham University. Experiencing and observing some significant problems with the current portfolio stimulated me to undertake a study on portfolio construction by integrating reflection into it. The aim of this study was to examine student teachers’ perceptions of their experiences of constructing a portfolio in order to develop a more reflect...

  14. Using Electronic Portfolios for Second Language Assessment

    Science.gov (United States)

    Cummins, Patricia W.; Davesne, Celine

    2009-01-01

    Portfolio assessment as developed in Europe presents a learner-empowering alternative to computer-based testing. The authors present the European Language Portfolio (ELP) and its American adaptations, LinguaFolio and the Global Language Portfolio, as tools to be used with the Common European Framework of Reference for languages and the American…

  15. Twelve tips for successful e-tutoring using electronic portfolios.

    Science.gov (United States)

    Deketelaere, Ann; Degryse, Jan; De Munter, Agnes; De Leyn, Paul

    2009-06-01

    E-tutoring by means of a digital portfolio offers personal guidance in a context in which regular face-to-face contact between supervisor and student is difficult. However, implementing e-tutoring in practice is not always straightforward. This article investigates the conditions for successful e-tutoring of electronic portfolios. A combination of three methods is used: our own experience with e-tutoring, interviews with 14 tutors using an e-portfolio and the answers on questionnaires by 107 students. We present 12 tips to increase the chances of successful e-tutoring when using electronic portfolios. E-tutoring by means of electronic portfolios can be a feasible alternative in contexts in which face-to-face tutoring is difficult.

  16. e-Portfolio as reflection tool during teaching practice: The interplay ...

    African Journals Online (AJOL)

    This paper focuses on an e-portfolio pilot initiative at the Faculty of Education ... expectations of an e-portfolio aligns with the current practices and attributes ... will impact the potential success of the integration of e-portfolios as reflective tools.

  17. Conditions for successful reflective use of portfolios in undergraduate medical education

    NARCIS (Netherlands)

    Driessen, Erik W.; Van Tartwijk, Jan; Overeem, Karlijn; Vermunt, Jan D.; Van Der Vleuten, C. P M

    2005-01-01

    AIM: Portfolios are often used as an instrument with which to stimulate students to reflect on their experiences. Research has shown that working with portfolios does not automatically stimulate reflection. In this study we addressed the question: What are the conditions for successful reflective

  18. An electronic portfolio for quantitative assessment of surgical skills in undergraduate medical education.

    Science.gov (United States)

    Sánchez Gómez, Serafín; Ostos, Elisa María Cabot; Solano, Juan Manuel Maza; Salado, Tomás Francisco Herrero

    2013-05-06

    We evaluated a newly designed electronic portfolio (e-Portfolio) that provided quantitative evaluation of surgical skills. Medical students at the University of Seville used the e-Portfolio on a voluntary basis for evaluation of their performance in undergraduate surgical subjects. Our new web-based e-Portfolio was designed to evaluate surgical practical knowledge and skills targets. Students recorded each activity on a form, attached evidence, and added their reflections. Students self-assessed their practical knowledge using qualitative criteria (yes/no), and graded their skills according to complexity (basic/advanced) and participation (observer/assistant/independent). A numerical value was assigned to each activity, and the values of all activities were summated to obtain the total score. The application automatically displayed quantitative feedback. We performed qualitative evaluation of the perceived usefulness of the e-Portfolio and quantitative evaluation of the targets achieved. Thirty-seven of 112 students (33%) used the e-Portfolio, of which 87% reported that they understood the methodology of the portfolio. All students reported an improved understanding of their learning objectives resulting from the numerical visualization of progress, all students reported that the quantitative feedback encouraged their learning, and 79% of students felt that their teachers were more available because they were using the e-Portfolio. Only 51.3% of students reported that the reflective aspects of learning were useful. Individual students achieved a maximum of 65% of the total targets and 87% of the skills targets. The mean total score was 345 ± 38 points. For basic skills, 92% of students achieved the maximum score for participation as an independent operator, and all achieved the maximum scores for participation as an observer and assistant. For complex skills, 62% of students achieved the maximum score for participation as an independent operator, and 98% achieved

  19. The learning portfolio as a tool for stimulating reflection by student teachers

    NARCIS (Netherlands)

    Mansvelder-Longayroux, Désirée Danièle

    2006-01-01

    The topic of this study is the portfolio that is being used in a teacher education institute as an instrument for stimulating reflection on their development as teachers by student teachers. This reflection can be seen in the themes student teachers have written in their portfolios. The nature of

  20. [Pedagogical reflective practice of nursing undergraduates: the portfolio as an instrument].

    Science.gov (United States)

    Vaz, Débora Rodrigues; Prado, Cláudia

    2014-12-01

    Analyzing the narratives related to the pedagogical practice experienced during the Supervised Curricular Internship reported in the portfolios of Nursing undergraduate students, regarding the levels of reflection. This is a documentary descriptive exploratory study that examined two of the activities proposed for the portfolio preparation. Among the 28 analyzed portfolios, all showed the three levels of reflection (technical, critical and metacritical). The students had the opportunity to experience the pedagogical practice and presented reflections at metacritical level, reflecting on their performance, the construction of their teaching identity, and about the importance of reflecting on the practice with the objective of transforming it and transforming themselves.

  1. Development of an Electronic Portfolio System Success Model: An Information Systems Approach

    Science.gov (United States)

    Balaban, Igor; Mu, Enrique; Divjak, Blazenka

    2013-01-01

    This research has two main goals: to develop an instrument for assessing Electronic Portfolio (ePortfolio) success and to build a corresponding ePortfolio success model using DeLone and McLean's information systems success model as the theoretical framework. For this purpose, we developed an ePortfolio success measurement instrument and structural…

  2. Implementing Reflective Portfolios for Promoting Autonomous Learning among EFL College Students in Taiwan

    Science.gov (United States)

    Lo, Ya-Fen

    2010-01-01

    This article depicts challenges for students and teachers involved in developing a reflective portfolio to promote autonomous learning in Taiwan. One hundred and one students in a Taiwan university completed their individual portfolio projects. A pre-course questionnaire, post-course self-evaluation, and the instructor's field notes were the data…

  3. Using Electronic Student Portfolios in Management Education: A Stakeholder Perspective.

    Science.gov (United States)

    Chappell, David S.; Schermerhorn, John R., Jr.

    1999-01-01

    A business school is using electronic student portfolios as an academic assessment and career development tool. They are also used for internship and job placements. It is recommended that they be mandatory, even for students with weaker computer skills, and they should have defined deadlines and feedback mechanisms. (SK)

  4. Learning while evaluating: the use of an electronic evaluation portfolio in a geriatric medicine clerkship

    Science.gov (United States)

    Duque, Gustavo; Finkelstein, Adam; Roberts, Ayanna; Tabatabai, Diana; Gold, Susan L; Winer, Laura R

    2006-01-01

    Background Electronic evaluation portfolios may play a role in learning and evaluation in clinical settings and may complement other traditional evaluation methods (bedside evaluations, written exams and tutor-led evaluations). Methods 133 third-year medical students used the McGill Electronic Evaluation Portfolio (MEEP) during their one-month clerkship rotation in Geriatric Medicine between September 2002 and September 2003. Students were divided into two groups, one who received an introductory hands-on session about the electronic evaluation portfolio and one who did not. Students' marks in their portfolios were compared between both groups. Additionally, students self-evaluated their performance and received feedback using the electronic portfolio during their mandatory clerkship rotation. Students were surveyed immediately after the rotation and at the end of the clerkship year. Tutors' opinions about this method were surveyed once. Finally, the number of evaluations/month was quantified. In all surveys, Likert scales were used and were analyzed using Chi-square tests and t-tests to assess significant differences in the responses from surveyed subjects. Results The introductory session had a significant effect on students' portfolio marks as well as on their comfort using the system. Both tutors and students reported positive notions about the method. Remarkably, an average (± SD) of 520 (± 70) evaluations/month was recorded with 30 (± 5) evaluations per student/month. Conclusion The MEEP showed a significant and positive effect on both students' self-evaluations and tutors' evaluations involving an important amount of self-reflection and feedback which may complement the more traditional evaluation methods. PMID:16409640

  5. Reflection and learning in clinical nursing education mediated by ePortfolio

    DEFF Research Database (Denmark)

    Nielsen, Kirsten; Pedersen, Birthe D.; Helms, Niels

    2015-01-01

    This paper reports on an investigation into learning mediated by the elective elements of an electronic portfolio (ePortfolio) designed to facilitate four learning styles. The design takes a phenomenological-hermeneutic approach. The setting was a ten-week clinical course in Basic Nursing...

  6. Do Scaffolding Tools Improve Reflective Writing in Professional Portfolios? A Content Analysis of Reflective Writing in an Advanced Preparation Program

    Science.gov (United States)

    Houston, Cynthia R.

    2016-01-01

    Reflective practice is an important skill that teachers must develop to be able to assess the effectiveness of their teaching and modify their instructional behavior. In many education programs reflective narratives, which are often part of teaching portfolios, are intended to assess students' abilities in these areas. Research on reflectivity in…

  7. ECLIPPx: an innovative model for reflective portfolios in life-long learning.

    Science.gov (United States)

    Cheung, C Ronny

    2011-03-01

    For healthcare professionals, the educational portfolio is the most widely used component of lifelong learning - a vital aspect of modern medical practice. When used effectively, portfolios provide evidence of continuous learning and promote reflective practice. But traditional portfolio models are in danger of becoming outmoded, in the face of changing expectations of healthcare provider competences today. Portfolios in health care have generally focused on competencies in clinical skills. However, many other domains of professional development, such as professionalism and leadership skills, are increasingly important for doctors and health care professionals, and must be addressed in amassing evidence for training and revalidation. There is a need for modern health care learning portfolios to reflect this sea change. A new model for categorising the health care portfolios of professionals is proposed. The ECLIPPx model is based on personal practice, and divides the evidence of ongoing professional learning into four categories: educational development; clinical practice; leadership, innovation and professionalism; and personal experience. The ECLIPPx model offers a new approach for personal reflection and longitudinal learning, one that gives flexibility to the user whilst simultaneously encompassing the many relatively new areas of competence and expertise that are now required of a modern doctor. © Blackwell Publishing Ltd 2011.

  8. Developing a Template for Electronic Portfolios in Career and Technical Education

    Science.gov (United States)

    Fowler, Matthew

    2012-01-01

    The purposes of this multiple case study were to determine if manufacturing and services sector employers found value in the use of an ePortfolio in the hiring process, and to develop a suggested template for an ePortfolio format to be used within career and technical education. Electronic portfolios "allow students to showcase their…

  9. Postgraduate Orthodontics Students' and Mentors' Perceptions of Portfolios and Discussion as Tools for Development of Reflection.

    Science.gov (United States)

    Tonni, Ingrid; Mora, Luca; Oliver, Richard G

    2016-09-01

    The aim of this study was to analyze the effects of a portfolio learning strategy designed to develop students' reflection abilities in a postgraduate orthodontic program in the UK. Nine first-year postgraduate orthodontic students and seven mentors participated in the one-year program, which included a reflective portfolio, mentorship, and discussion. After the program, the students' and mentors' perceptions were collected using focus groups and individual interviews, respectively. The data were analyzed using thematic analysis. Four categories emerged. The first, reflection, was considered a skill to learn, and time was needed for students to fully understand its meaning and achieve its outcomes. The second theme, characteristics of reflection, was descriptive at the beginning and more critical at the end of the experience. The third theme, outcomes of reflection, involved students' improved problem-solving and action-planning abilities and increased self-awareness, motivation, confidence, and communication skills. In the fourth theme, stimulation of reflection, students did not agree with mentors regarding the importance of reflective writing, but they recognized the value of the portfolio's reflective log in facilitating the reflective process. There was greater agreement between students and mentors regarding discussions with mentors and among peers as tools to achieve higher levels of reflection. Overall, these students and mentors considered the strategy an effective tool for improving students' reflection.

  10. Evaluation of the free, open source software WordPress as electronic portfolio system in undergraduate medical education.

    Science.gov (United States)

    Avila, Javier; Sostmann, Kai; Breckwoldt, Jan; Peters, Harm

    2016-06-03

    Electronic portfolios (ePortfolios) are used to document and support learning activities. E-portfolios with mobile capabilities allow even more flexibility. However, the development or acquisition of ePortfolio software is often costly, and at the same time, commercially available systems may not sufficiently fit the institution's needs. The aim of this study was to design and evaluate an ePortfolio system with mobile capabilities using a commercially free and open source software solution. We created an online ePortfolio environment using the blogging software WordPress based on reported capability features of such software by a qualitative weight and sum method. Technical implementation and usability were evaluated by 25 medical students during their clinical training by quantitative and qualitative means using online questionnaires and focus groups. The WordPress ePortfolio environment allowed students a broad spectrum of activities - often documented via mobile devices - like collection of multimedia evidences, posting reflections, messaging, web publishing, ePortfolio searches, collaborative learning, knowledge management in a content management system including a wiki and RSS feeds, and the use of aid tools for studying. The students' experience with WordPress revealed a few technical problems, and this report provides workarounds. The WordPress ePortfolio was rated positively by the students as a content management system (67 % of the students), for exchange with other students (74 %), as a note pad for reflections (53 %) and for its potential as an information source for assessment (48 %) and exchange with a mentor (68 %). On the negative side, 74 % of the students in this pilot study did not find it easy to get started with the system, and 63 % rated the ePortfolio as not being user-friendly. Qualitative analysis indicated a need for more introductory information and training. It is possible to build an advanced ePortfolio system with mobile

  11. Qualitative study of the impact of an authentic electronic portfolio in undergraduate medical education.

    Science.gov (United States)

    Belcher, Rosie; Jones, Anna; Smith, Laura-Jane; Vincent, Tim; Naidu, Sindhu Bhaarrati; Montgomery, Julia; Haq, Inam; Gill, Deborah

    2014-12-17

    Portfolios are increasingly used in undergraduate and postgraduate medical education. Four medical schools have collaborated with an established NHS electronic portfolio provider to develop and implement an authentic professional electronic portfolio for undergraduate students. We hypothesized that using an authentic portfolio would have significant advantages for students, particularly in familiarizing them with the tool many will continue to use for years after graduation. This paper describes the early evaluation of this undergraduate portfolio at two participating medical schools. To gather data, a questionnaire survey with extensive free text comments was used at School 1, and three focus groups were held at School 2. This paper reports thematic analysis of students' opinions expressed in the free text comments and focus groups. Five main themes, common across both schools were identified. These concerned the purpose, use and acceptability of the portfolio, advantages of and barriers to the use of the portfolio, and the impacts on both learning and professional identity. An authentic portfolio mitigated some of the negative aspects of using a portfolio, and had a positive effect on students' perception of themselves as becoming past of the profession. However, significant barriers to portfolio use remained, including a lack of understanding of the purpose of a portfolio and a perceived damaging effect on feedback.

  12. Does Using E-Portfolios for Reflective Writing Enhance High School Students' Self-Regulated Learning?

    Science.gov (United States)

    Chang, Chi-Cheng; Liang, Chaoyun; Shu, Kuen-Ming; Tseng, Kuo-Hung; Lin, Chun-Yu

    2016-01-01

    The study aims to examine whether reflective writing using e-portfolios enhances high school students' self-regulated learning. Participants included two classes of eighth-graders majoring in Information Processing and taking a course called "Website Design" at a vocational high school in Taiwan. There were 41 students, with 18 males and…

  13. The CanMEDS portfolio: a tool for reflection in a fellowship programme.

    Science.gov (United States)

    Berger, Elizabeth; Shouldice, Michelle; Kuper, Ayelet; Albert, Mathieu

    2011-09-01

    We developed a portfolio framed by the CanMEDS roles for use in a paediatric fellowship programme. The portfolio includes four components: a record of participation and achievement; career goals and professional development; physical evidence; and reflective writing. Once the portfolio was in use for 6 months, we studied how fellows and faculty members were using the portfolio, and what they found to be its advantages and disadvantages. Fellows reported that it kept them organised and assisted them in setting their goals. They appreciated having a central place to record their accomplishments, as this allowed them to keep a thorough curriculum vitae. The portfolio was helpful in giving them the opportunity to honestly reflect on their achievements and setbacks, and, after reviewing this in their own minds, they were in a strong position to set an agenda for their meetings with supervisors. Both the fellows and supervisors were in agreement that the portfolio led to improved discussions at their meetings. Both groups also reported that this new tool was useful in furthering the career development of trainees, which was one of the main goals in its inception. Faculty supervisors also had a stronger sense of the fellows' work, and also of any gaps in training, as a result of using this tool. We hope that this reflection tool will be adapted for use in other training programmes. If it is introduced elsewhere, we would recommend that learners and staff receive ample training in its use so that it can be maximally effective. © Blackwell Publishing Ltd 2011.

  14. Impact of Electronic Portfolios on Prospective Teachers' Participation, Motivation, and Autonomous Learning

    Science.gov (United States)

    Gámiz-Sánchez, Vanesa-María; Gallego-Arrufat, María-Jesús; Crisol-Moya, Emilio

    2016-01-01

    This study explores the impact of electronic portfolios on undergraduate learning in higher education. Based on a descriptive study, it analyses the prospective teacher's perception of use of these tools (electronic portfolio in Moodle-Mahara, in the institutional environment of a university in southern Europe), examining the variables…

  15. Teacher Electronic Portfolio and its Relation to EFL Student Teacher Performance and Attitude

    Directory of Open Access Journals (Sweden)

    Areej T Alshawi

    2017-01-01

    Full Text Available E-portfolio is a promising approach to develop teachers into reflective practitioners who show that they can adapt to new technologies, new criteria, and new environments. The current research explored the quality of EFL student teachers’ e-portfolios and their attitudes towards using them. The research was conducted on 30 EFL female student teachers at Princess Noura bint Abdulrahman University, Saudi Arabia. The participants were engaging in practical training at schools and reflecting their skills and experiences in their e-portfolios. This research posed further questions about the relationships between the quality of EFL student teachers’ e-portfolios, their attitudes towards using them and their teaching performance. In order to explore the possible answers, the participants’ teaching performance were observed, their e-portfolios were evaluated by a rubric, and a 24-item questionnaire was administered to them. The results proved high proficiency level of the EFL student teachers’ e-portfolios and positive attitudes towards using e-portfolios among EFL student teachers. Furthermore, the results denoted a statistically significant positive relationship between the quality of EFL student teachers’ e-portfolio and their teaching performance. The results of this study may encourage policy makers to integrate the idea of e-portfolio and reflection as an effective component in teacher education and development.

  16. Are Integrated Portfolio Systems the Answer? An Evaluation of a Web-Based Portfolio System to Improve Preservice Teachers' Reflective Thinking Skills

    Science.gov (United States)

    Oner, Diler; Adadan, Emine

    2016-01-01

    This study investigated the effectiveness of an integrated web-based portfolio system, namely the BOUNCE System, which primarily focuses on improving preservice teachers' reflective thinking skills. BOUNCE©, the software component of the system, was designed and developed to support a teaching practice model including a cycle of activities to be…

  17. THE MAIN PROBLEMS OF THE STUDENTS’ ELECTRONIC PORTFOLIO FORMATION IN TERMS OF THE HIGHER EDUCATIONAL PROGRAMS

    Directory of Open Access Journals (Sweden)

    Yulia V. Dementieva

    2016-01-01

    Full Text Available The aim of the study is the description of the main problems of formation of the student’s electronic portfolio in the conditions of realization of Federal State Educational Standards of the Higher Education (FSES of HE.Methods.Theoretical analysis of scientific literature concerning the subject under discussion; monitoring of existing practices in modern Russian Universities procedures for the formation and maintenance of students electronic portfolio.Results. The author describes the main problems of the electronic students’ portfolio formation; some ways of solving described problems are offered.Scientific novelty concludes in the formation of key ideas of the electronic students’ portfolio based on the understanding of requirements of Federal State Educational Standards of Higher Education for the results of mastering educational programs. They are the formation of general cultural, general professional and professional competences.Practical significance. The researching results will become the theoretical basis for the systematic organization of the process of creating and maintaining an electronic students’ portfolio during the whole period of their studying at the university; the researching results can become a basis for methodological developments.

  18. Reflection of the Cointegration Relation among the Stock Markets on the Portfolio Choices: An Empirical Application for Fragile Five Countries

    Directory of Open Access Journals (Sweden)

    Gulfen Tuna

    2016-12-01

    Full Text Available The aim of this study is to examine the long-term relationship between each pair of the countries separate from those in the Stock Markets of Fragile Five Countries and determine the optimal portfolio options for each of the BIITS countries according to the pieces of evidence obtained. Thus, the reflection of the concertedness among financial markets to the optimal portfolio options has been studied. Accordingly, long term relationships between each pair of BIITS countries have been investigated with monthly price value between June 2006 and July 2015 by means of Maki Cointegration Test. Optimal portfolio options have been established according to the Markowitz Model considering the long-term relationships between the markets. The pieces of evidence obtained show that lower-risk portfolios than the ones in their own national markets can be established in BIITS countries by applying international diversification

  19. Using a portfolio of evidence in a community-based project module: reflection in perspective

    Directory of Open Access Journals (Sweden)

    PH van der Westhuizen

    2014-01-01

    Full Text Available Community-based learning is a relatively new field in South Africa. It has only been extensively included in academic programmes at universities for about fifteen years.Students have to make a positive contribution to individuals in their communities (Dukhan 2008:21 and develop a combination of knowledge, skills, values and motivation in order to make a difference, and to promote the quality of life in a community (O Connor 2006: 52.Too often assessment reflects on a single quantitative measure or symbol to indicate a level of achievement. This aggregate does not, however, indicate the student‟s particular weaknesses and strengths, and whether or not he or she possesses competencies in a specific aspect. A more objective method/procedure of reporting assessment on levels of achievement and competency obtained is the compilation of a portfolio. The main aim of this paper is to provide some guidelines for the compilation and implementation of portfolios as a tool in authentic assessment for the student, but also acts as a document that would guide a community into the sustainability of the project.

  20. Using Electronic Portfolio to Promote Professional Learning Community for Pre-Service Early Childhood Teachers at Alquds University

    Science.gov (United States)

    Khales, Buad

    2016-01-01

    The present study aims to explore whether the electronic portfolio can influence pre-service teachers' education and to examine how professional learning communities develop through electronic portfolios. To achieve this, twenty-four student-teachers taking a course in early childhood education at Al-Quds University participated in a study to…

  1. Does a summative portfolio foster the development of capabilities such as reflective practice and understanding ethics? An evaluation from two medical schools.

    Science.gov (United States)

    O'Sullivan, Anthony J; Howe, Amanda C; Miles, Susan; Harris, Peter; Hughes, Chris S; Jones, Philip; Scicluna, Helen; Leinster, Sam J

    2012-01-01

    Portfolios need to be evaluated to determine whether they encourage students to develop in capabilities such as reflective practice and ethical judgment. The aims of this study were (i) to determine whether preparing a portfolio helps promote students' development in a range of capabilities including understanding ethical and legal principles, reflective practice and effective communication, and (ii) to determine to what extent the format of the portfolio affected the outcome by comparing the experiences of students at two different medical schools. A questionnaire was designed to evaluate undergraduate medical students' experiences of completing a portfolio at two medical schools. A total of 526 (45% response rate) students answered the on-line questionnaire. Students from both medical schools gave the highest ranking for the portfolio as a trigger for reflective practice. 63% of students agreed their portfolio helped them develop reflective practice skills (p portfolios helped them understand ethical and legal principles whereas 29% disagreed (p portfolio helped them to develop effective communication. Students perceive portfolio preparation as an effective learning tool for the development of capabilities such as understanding ethical and legal principles and reflective practice, whereas other capabilities such as effective communication require complementary techniques and other modes of assessment.

  2. Guided Portfolio Writing as a Scaffold for Reflective Learning in In-Service Contexts: A Case Study

    Science.gov (United States)

    Pires Pereira, Íris Susana; Cristo Parente, Maria Cristina; Vieira da Silva, Cristina

    2016-01-01

    Language is widely recognized as an inescapable mediating tool for professional learning, and with this text we want to contribute to a better understanding of the particular role that guided writing can play in in-service professional reflective learning. We analysed one pre-school teacher's written portfolio, the construction of which was guided…

  3. Helping University Students Succeed at Employment Interviews: The Role of Self-Reflection in E-Portfolios

    Science.gov (United States)

    Lackner, Christine; Martini, Tanya

    2017-01-01

    In the context of a Transition to Work course for fourth-year psychology majors, we had students use an e-portfolio to self-reflect on the learning experiences they deemed most significant during their degree. Such significant learning experiences can be drawn upon when answering behavioral job interview questions. We examined whether students…

  4. Teacher Portfolios.

    Science.gov (United States)

    Wolfe-Quintero, Kate; Brown, James Dean

    1998-01-01

    A portfolio of achievements, experiences, and reflections can help English-as-a-Second-Language teachers attain professional development goals and offer administrators greater insight for making informed hiring and job-performance decisions. This paper focuses on what teacher portfolios are, what their contents should be, and what their uses are…

  5. Electronic Portfolios in Grades One, Two and Three: A Cautionary Tale

    Science.gov (United States)

    Kotsopoulos, Donna; Lee, Joanne; Cordy, Michelle; Bruyns, Susan

    2015-01-01

    Some electronic portfolios (EPs) developers are proposing that EPs are suitable for implementation in primary education (i.e. kindergarten to grade three). Yet, empirical research evaluating the implementation and efficacy of EPs used in primary school settings at both the teacher and the student level is scarce. In this research, the authors…

  6. Looking Back to Move Forward: First-Year Medical Students' Meta-Reflections on Their Narrative Portfolio Writings.

    Science.gov (United States)

    Cunningham, Hetty; Taylor, Delphine; Desai, Urmi A; Quiah, Samuel C; Kaplan, Benjamin; Fei, Lorraine; Catallozzi, Marina; Richards, Boyd; Balmer, Dorene F; Charon, Rita

    2018-06-01

    The day-to-day rigors of medical education often preclude learners from gaining a longitudinal perspective on who they are becoming. Furthermore, the current focus on competencies, coupled with concerning rates of trainee burnout and a decline in empathy, have fueled the search for pedagogic tools to foster students' reflective capacity. In response, many scholars have looked to the tradition of narrative medicine to foster "reflective spaces" wherein holistic professional identity construction can be supported. This article focuses on the rationale, content, and early analysis of the reflective space created by the narrative medicine-centered portfolio at the Columbia University Vagelos College of Physicians and Surgeons. In January 2015, the authors investigated learning outcomes derived from students' "Signature Reflections," end-of-semester meta-reflections on their previous portfolio work. The authors analyzed the Signature Reflections of 97 (of 132) first-year medical students using a constant comparative process. This iterative approach allowed researchers to identify themes within students' writings and interpret the data. The authors identified two overarching interpretive themes-recognition and grappling-and six subthemes. Recognition included comments about self-awareness and empathy. Grappling encompassed the subthemes of internal change, dichotomies, wonder and questioning, and anxiety. Based on the authors' analyses, the Signature Reflection seems to provide a structured framework that encourages students' reflective capacity and the construction of holistic professional identity. Other medical educators may adopt meta-reflection, within the reflective space of a writing portfolio, to encourage students' acquisition of a longitudinal perspective on who they are becoming and how they are constructing their professional identity.

  7. Utilisation of an electronic portfolio to engage rehabilitation professionals in continuing professional development: results of a provincial survey.

    Science.gov (United States)

    Foucault, Marie-Lyse; Vachon, Brigitte; Thomas, Aliki; Rochette, Annie; Giguère, Charles-Édouard

    2018-06-01

    ePortfolios are frequently used to support continuing professional development (CPD) of rehabilitation professionals. Though this tool is now widely implemented in many professions by regulatory organisations, very few studies have investigated the use and impact among rehabilitation professionals. Implementation of comprehensive ePortfolios that are centred on the needs of rehabilitation professionals requires documenting their level of use and perceived outcomes. The objectives were to describe how occupational therapists use a mandatory ePortfolio that has been recently implemented by a regulatory organisation in Quebec (Canada) and the perceived outcomes of this requirement on continuing professional development and practice change. An online survey was sent to all registered occupational therapists in Quebec using the ePortfolio. The survey content was developed based on a literature review and expert consultation. Results were analysed using descriptive statistics. A total of 546 respondents completed the survey. Results show relatively high levels of ease and satisfaction with the tool, but a limited perception of the tool's impacts on the improvement of professional competencies and change in practices. Occupational therapists reported that use of the ePortfolio supports their engagement in CPD but has limited impact on practice. Promotion of work-based learning, team use and mentor support could increase its meaningfulness for professionals. Implications for Rehabilitation To improve attitudes and beliefs about benefits related to portfolio use, rehabilitation practitioners need a very clear understanding of the purpose and usefulness of a portfolio in clinical practice. Most of the respondents saw the ePortfolio as helping them develop and implement a continuing professional development plan and reflect on the changes needed in their practice. Portfolio use in teams and productive reflection should be promoted in order to target shared objectives for

  8. Slow electron contribution to inelastic reflection anisotropy

    International Nuclear Information System (INIS)

    Podsvirov, O.A.; Kuznetsov, Yu.A.

    1980-01-01

    Investigated is electron contribution with low energy (up to 1 keV) to the anisotropy of electron inelastic reflection (IRE) from silicon monocrystal (111) within 12-50 keV energy range of primary electrons. Experimental data on IRE anisotropy are presented: delay curves for silicon monocrystal, permitting to separate electrons with the energy up to 1 keV, dependences of IRE anisotropy on the energy of primary electrons for the systems - monocrystalline silicon-amorphous silicon film and delay curves for such systems (film thickness varies from 20 to 2000 A). Suggested is a phenomenologic model, permitting to take into account the contribution of slow electrons to IRE anisotropy: it is supposed, that three groups of electrons take part in the formation of the latter: elastic and inelastic reflected electrons, slow electrons, excited by primary electrons and slow electrons, generated by the reverse flow of the scattered electrons. Contribution of electrons, different by origin, to IRE anisotropy is evaluated in accordance with the experimental data on the basis of this model. It is stated, that slow electrons constitute approximately one half of the IRE anisotropy value, the contribution of both groups of slow electrons being approximately equal

  9. e-Portfolio as reflection tool during teaching practice: The interplay ...

    African Journals Online (AJOL)

    Strydom, SC, Dr

    2017-02-01

    Feb 1, 2017 ... students will impact the potential success of the integration of ... continuous professional development, e-portfolios .... placed on lifelong and life-wide learning within the ..... http://electronicportfolios.org/balance/balancingarti.

  10. Implementing portfolio in postgraduate general practice training. Benefits and recommendations.

    Science.gov (United States)

    Alotaibi, Fawaz S

    2012-10-01

    This paper presents a review to explore the literature focusing on portfolio in postgraduate general practice (GP) training, and to examine the impact of implementation of portfolio on learning process, as well as proposing recommendations for its implementation in postgraduate GP training. An electronic search was carried out on several databases for studies addressing portfolio in postgraduate GP training. Six articles were included to address specifically the effectiveness of portfolio in postgraduate GP training. Five of them described successful experiences of portfolio-based learning implementation. Only one article addressed portfolio-based assessment in postgraduate GP training. The existing evidence provides various benefits of professional portfolio-based learning. It does appear to have advantages of stimulating reflective learning, promoting proactive learning, and bridging the hospital experiences of the learners to GP. Moreover, the challenges to implementation of portfolio-based learning are often based on orientation and training of stakeholders.

  11. The standard for portfolio management

    CERN Document Server

    2017-01-01

    The Standard for Portfolio Management – Fourth Edition has been updated to best reflect the current state of portfolio management. It describe the principles that drive accepted good portfolio management practices in today’s organizations. It also expands the description of portfolio management to reflect its relation to organizational project management and the organization.

  12. Status of portfolios in undergraduate medical education in the LCME accredited US medical school.

    Science.gov (United States)

    Chertoff, Jason; Wright, Ashleigh; Novak, Maureen; Fantone, Joseph; Fleming, Amy; Ahmed, Toufeeq; Green, Marianne M; Kalet, Adina; Linsenmeyer, Machelle; Jacobs, Joshua; Dokter, Christina; Zaidi, Zareen

    2016-09-01

    We sought to investigate the number of US medical schools utilizing portfolios, the format of portfolios, information technology (IT) innovations, purpose of portfolios and their ability to engage faculty and students. A 21-question survey regarding portfolios was sent to the 141 LCME-accredited, US medical schools. The response rate was 50% (71/141); 47% of respondents (33/71) reported that their medical school used portfolios in some form. Of those, 7% reported the use of paper-based portfolios and 76% use electronic portfolios. Forty-five percent reported portfolio use for formative evaluation only; 48% for both formative and summative evaluation, and 3% for summative evaluation alone. Seventy-two percent developed a longitudinal, competency-based portfolio. The most common feature of portfolios was reflective writing (79%). Seventy-three percent allow access to the portfolio off-campus, 58% allow usage of tablets and mobile devices, and 9% involve social media within the portfolio. Eighty percent and 69% agreed that the portfolio engaged students and faculty, respectively. Ninety-seven percent reported that the portfolios used at their institution have room for improvement. While there is significant variation in the purpose and structure of portfolios in the medical schools surveyed, most schools using portfolios reported a high level of engagement with students and faculty.

  13. [Reflective portfolio: a proposal for teaching and learning geared on competencies].

    Science.gov (United States)

    Cotta, Rosângela Minardi Mitre; da Costa, Glauce Dias; Mendonça, Erica Toledo

    2013-06-01

    This article seeks to analyze the experience of collective construction of portfolios as a teaching-learning method in the discipline of Health Policy, identifying the competencies developed by students. Qualitative research, whose collection and data processing were conducted by means of documental and thematic analysis of 34 portfolios. The "Learning to be" and "Learning to live and work together" competencies were considered according to the proposals of the UNESCO report for Education. The training of critical-reflexive individuals, provided by the portfolio, was particularly observed when students reported the transformation of the negative views that they had about the health care system - an inefficient and precarious policy - to a positive vision - policy which deals with the principles of equity, integrity and universality. This process of critical transformation is the result of the practice and use of communication skills, information management (search, selection, analysis and evaluation of information), leadership, cooperation and human relationships (teamwork, ethics and recognition of diversity), and personal competencies (time management, responsibility and planning), namely important skills in the training of professionals committed to the national health policy.

  14. The Use of ePortfolios to Support Metacognitive Practice in a First-Year Writing Program

    Science.gov (United States)

    Bowman, Jim; Lowe, Barbara J.; Sabourin, Katie; Sweet, Catherine Salomon

    2016-01-01

    Recognizing the importance of meaningful reflective writing as an integral component to the portfolios used in the first-year program (FYP), faculty questioned whether a newly developed electronic portfolio offered any pedagogical benefits over the existing traditional paper portfolio. Of particular interest for this work was whether the use of…

  15. Evaluation of an established learning portfolio.

    Science.gov (United States)

    Vance, Gillian; Williamson, Alyson; Frearson, Richard; O'Connor, Nicole; Davison, John; Steele, Craig; Burford, Bryan

    2013-02-01

    The trainee-held learning portfolio is integral to the foundation programme in the UK. In the Northern Deanery, portfolio assessment is standardised through the Annual Review of Competence Progression (ARCP) process. In this study we aimed to establish how current trainees evaluate portfolio-based learning and ARCP, and how these attitudes may have changed since the foundation programme was first introduced. Deanery-wide trainee attitudes were surveyed by an electronic questionnaire in 2009 and compared with perceptions recorded during the pilot phase (2004-2005).  Many trainees continue to view the e-portfolio negatively. Indeed, significantly fewer trainees in 2009 thought that the e-portfolio was a 'good idea' or a 'worthwhile investment of time' than in 2005. Trainees remain unconvinced about the educational value of the e-portfolio: fewer trainees in 2009 regarded it as a tool that might help focus on training or recognise individual strengths and weaknesses. Issues around unnecessary bureaucracy persist. Current trainees tend to understand how to use the e-portfolio, but many did not know how much, or what evidence to collect. Few supervisors were reported to provide useful guidance on the portfolio. ARCP encouraged portfolio completion but did not give meaningful feedback to drive future learning.   Continued support is needed for both trainees and supervisors in portfolio-building skills and in using the e-portfolio as an educational tool. Trainee-tailored feedback is needed to ensure that portfolio-based assessment promotes lifelong, self-directed and reflective learners. © Blackwell Publishing Ltd 2013.

  16. Virtual reflections in electronic acoustic architecture

    Science.gov (United States)

    van Munster, Bjorn

    2005-09-01

    In the era of the ancient Greeks and Byzantines, the first attempts for increasing reverberation time are noted. In the 1950s, the Ambiophonic system accomplished this by means of an electronic device, for the first time. The early systems only increased the reverberation time by delaying the picked-up reverberation. With the introduction of multichannel feedback-based systems, the reverberation level also could be increased. Later, it was understood that it was important to also fill in the missing reflections, address reflection density, frequency dependence, etc. This resulted in the development of the SIAP concept. Current DSP technology led to the development of a processor whereby density, length, level, and the frequency content can be controlled for different areas in the same room or different rooms, leading to the concept of the acoustic server. electronic acoustic architecture has become the current state-of-the-art approach for solving acoustic deficiencies in, among others, rehearsal rooms, theaters, churches, and multipurpose venues. Incorporation of complementary passive acoustic solutions provides an optimum solution for all room problems. This paper discusses the utilization of virtual reflections in the new approach of electronic acoustic architecture for different environments. Measurements performed in the Sejong Performing Arts Centre, Seoul, South Korea, show the power of this approach.

  17. Online Reflective Writing Mechanisms and Its Effects on Self-Regulated Learning: A Case of Web-Based Portfolio Assessment System

    Science.gov (United States)

    Liang, Chaoyun; Chang, Chi-Cheng; Shu, Kuen-Ming; Tseng, Ju-Shih; Lin, Chun-Yu

    2016-01-01

    The purpose of the present study was to design reflective writing mechanisms in a web-based portfolio assessment system and evaluate its effects on self-regulated learning. Participants were two classes of juniors majoring in data processing and taking a course called "Website design" at a vocational high school in Taiwan. One class was…

  18. Decreasing Off-Task Behavior through a Dot/Point Reward System and Portfolio Reflection with Second, Fifth, and Sixth Graders

    Science.gov (United States)

    Butera, Lisa M.; Giacone, Maria V.; Wagner, Kelly A.

    2008-01-01

    The purpose of this action research project report was to decrease off-task behavior through a dot/point reward system and portfolio reflections. Students involved in this research were in second, fifth, and sixth grade. There were a total of 85 student participants and 35 teacher participants. The dates of this research began on September 4, 2007…

  19. The Role of the Electronic Portfolio in Enhancing Information and Communication Technology and English Language Skills: The Voices of Six Malaysian Undergraduates

    Science.gov (United States)

    Thang, Siew Ming; Lee, Yit Sim; Zulkifli, Nurul Farhana

    2012-01-01

    This study investigated the effects of the construction and development of electronic portfolios (e-portfolios) on a small user population at a public university in Malaysia. The study was based on a three-month Information and Communication Technology (ICT) and language learning course offered to the undergraduates of the university. One of the…

  20. e-Portfolio as reflection tool during teaching practice: The interplay ...

    African Journals Online (AJOL)

    Strydom, SC, Dr

    2017-02-01

    Feb 1, 2017 ... skills, and, to a lesser degree, to the memorisation of content, which suggests that ... reflective practice and develop their own personal theories, to utilise such practices as .... experiences in terms of employability and work-.

  1. Rapid application design of an electronic clinical skills portfolio for undergraduate medical students.

    Science.gov (United States)

    Dornan, Tim; Lee, Catherine; Stopford, Adam; Hosie, Liam; Maredia, Neil; Rector, Alan

    2005-04-01

    The aim was to find how to use information and communication technology to present the clinical skills content of an undergraduate medical curriculum. Rapid application design was used to develop the product, and technical action research was used to evaluate the development process. A clinician-educator, two medical students, two computing science masters students, two other project workers, and a hospital education informatics lead, formed a design team. A sample of stakeholders took part in requirements planning workshops and continued to advise the team throughout the project. A university hospital had many features that favoured fast, inexpensive, and successful system development: a clearly defined and readily accessible user group; location of the development process close to end-users; fast, informal communication; leadership by highly motivated and senior end-users; devolved authority and lack of any rigidly imposed management structure; cooperation of clinicians because the project drew on their clinical expertise to achieve scholastic goals; a culture of learning and involvement of highly motivated students. A detailed specification was developed through storyboarding, use case diagramming, and evolutionary prototyping. A very usable working product was developed within weeks. "SkillsBase" is a database web application using Microsoft Active Server Pages, served from a Microsoft Windows 2000 Server operating system running Internet Information Server 5.0. Graphing functionality is provided by the KavaChart applet. It presents the skills curriculum, provides a password-protected portfolio function, and offers training materials. The curriculum can be presented in several different ways to help students reflect on their objectives and progress towards achieving them. The reflective portfolio function is entirely private to each student user and allows them to document their progress in attaining skills, as judged by self, peer and tutor assessment, and

  2. E-PORTFOLIO: BEYOND ASSESSMENT FOR ENGLISH STUDENT TEACHER (a Preliminary Study of E-portfolio Implementation in Micro Teaching Class)

    OpenAIRE

    Sarlita D. Matra

    2017-01-01

    Teacher preparation programs across the country are showing an increased interest in the use of electronic portfolios as valuable authentic assessment tools that can document students‘ abilities and growth related to specific standards. The concept of developing e-portfolios is based on the fact that the reflective practice of creating portfolios enables students to document and track their learning; develop an integrated, coherent picture of their learning experiences; and enhanc...

  3. Exploring students' perceptions on the use of significant event analysis, as part of a portfolio assessment process in general practice, as a tool for learning how to use reflection in learning.

    Science.gov (United States)

    Grant, Andrew J; Vermunt, Jan D; Kinnersley, Paul; Houston, Helen

    2007-03-30

    Portfolio learning enables students to collect evidence of their learning. Component tasks making up a portfolio can be devised that relate directly to intended learning outcomes. Reflective tasks can stimulate students to recognise their own learning needs. Assessment of portfolios using a rating scale relating to intended learning outcomes offers high content validity. This study evaluated a reflective portfolio used during a final-year attachment in general practice (family medicine). Students were asked to evaluate the portfolio (which used significant event analysis as a basis for reflection) as a learning tool. The validity and reliability of the portfolio as an assessment tool were also measured. 81 final-year medical students completed reflective significant event analyses as part of a portfolio created during a three-week attachment (clerkship) in general practice (family medicine). As well as two reflective significant event analyses each portfolio contained an audit and a health needs assessment. Portfolios were marked three times; by the student's GP teacher, the course organiser and by another teacher in the university department of general practice. Inter-rater reliability between pairs of markers was calculated. A questionnaire enabled the students' experience of portfolio learning to be determined. Benefits to learning from reflective learning were limited. Students said that they thought more about the patients they wrote up in significant event analyses but information as to the nature and effect of this was not forthcoming. Moderate inter-rater reliability (Spearman's Rho .65) was found between pairs of departmental raters dealing with larger numbers (20-60) of portfolios. Inter-rater reliability of marking involving GP tutors who only marked 1-3 portfolios was very low. Students rated highly their mentoring relationship with their GP teacher but found the portfolio tasks time-consuming. The inter-rater reliability observed in this study should

  4. Reflections on clinical practice whilst developing a portfolio of evidence: Perceptions of undergraduate nursing students in the Western Cape, South Africa

    Directory of Open Access Journals (Sweden)

    Victoire Ticha

    2015-12-01

    Full Text Available Background: In order to develop clinical judgement, nurses should be encouraged to become analytical and critical thinkers. Development of a portfolio of evidence (PoE of reflection on clinical experiences is one of the strategies that can be used to enhance analytical and critical thinking amongst nursing students. Students’ perceptions of the process are important in order to encourage their reflective practice. PoE compilation at a school of nursing at a university in the Western Cape includes evidence of students’ clinical learning which they present in a portfolio. The students are expected to reflect on their clinical learning experiences and include these reflections in their portfolios. Objective: To describe the perceptions of fourth-year nursing students regarding reflective practice whilst compiling their PoEs. Method: A qualitative design was used to explore the perceptions of registered fourth-year nursing students with regard to their reflective practice whilst compiling their PoEs. Purposive sampling was used for selection of participants. Three focus group discussions were held, each consisting of six to eight participants. Data saturation was reached during the third meeting. Tesch’s method of data analysis was used. Results: Findings revealed that reflection enabled the learners to gain experience and identify challenges related to the expected events and tasks carried out at the hospitals and in the classroom whilst developing their PoE. Conclusion: The compilation of a PoE was a good teaching and learning strategy, and the skills, experience and knowledge that the participants in this study acquired boosted their self-esteem, confidence and critical thinking. Reflection also assisted in self-directed learning.

  5. Portfolio Optimization

    OpenAIRE

    Issagali, Aizhan; Alshimbayeva, Damira; Zhalgas, Aidana

    2015-01-01

    In this paper Portfolio Optimization techniques were used to determine the most favorable investment portfolio. In particular, stock indices of three companies, namely Microsoft Corporation, Christian Dior Fashion House and Shevron Corporation were evaluated. Using this data the amounts invested in each asset when a portfolio is chosen on the efficient frontier were calculated. In addition, the Portfolio with minimum variance, tangency portfolio and optimal Markowitz portfolio are presented.

  6. Evaluation of the training capacity of the Spanish Resident Book of Otolaryngology (FORMIR) as an electronic portfolio.

    Science.gov (United States)

    Maza Solano, Juan Manuel; Benavente Bermudo, Gustavo; Estrada Molina, Francisco José; Ambrosiani Fernández, Jesús; Sánchez Gómez, Serafín

    2017-08-10

    and objectives We have evaluated the training capacity of the Spanish resident training book as an electronic portfolio to achieve the learning objectives of otorhinolaryngology (ENT) residents. A multi-method qualitative investigation with transversal characteristics, temporal and retrospective guidance was performed on Spanish ENT residents using a structured questionnaire, a semi-structured interview, and a computer application on the FORMIR website. A 56.5% of ENT-residents specialising in one of the 63 accredited Spanish hospitals between 2009-2012 participated in the study. The results obtained show that the ENT residents who used the e-portfolio were better able to implement self-guided study, were more aware of their learning objectives, fulfilled the training programme more efficiently, identified the causes of learning gaps more clearly, and considered FORMIR in e-portfolio format to be an ideal training tool to replace the resident training book in paper format. The ENT residents greatly appreciated the training benefits of FORMIR as an e-portfolio, especially its simple and intuitive interface, the ease and comfort with which they could record their activities, the automatic and numeric feedback on the acquisition of their competencies (which facilitates self-guided learning), its storage capacity for evidence, and its ability to be used as UEMS logbook as well as a standard curriculum vitae. All these features make FORMIR a training and evaluation tool that outperforms similar instruments available to ENT residents. They do not hesitate to identify it as the ideal resident training book for facilitating their specialised training. Copyright © 2017 Elsevier España, S.L.U. and Sociedad Española de Otorrinolaringología y Cirugía de Cabeza y Cuello. All rights reserved.

  7. Tracing the Reflective Practices of Student Teachers in Online Modes

    Science.gov (United States)

    Farr, Fiona; Riordan, Elaine

    2015-01-01

    During the course of pre-and in-service teacher education programmes, reflection can happen in a number of ways, for example: reflective journals, personal stories and pair/group co-operative discussions, professional development portfolios, and blogs and electronic portfolios. The aim of this paper is to examine various technologies such as…

  8. Reflection of oblique electron thermal modes in an inhomogeneous plasma

    International Nuclear Information System (INIS)

    Ohnuma, T.; Watanabe, T.; Sanuki, H.

    1980-04-01

    In an inhomogeneous magnetoplasma, reflection of an oblique electron thermal mode radiated from a local source is investigated experimentally and theoretically near the electron plasma frequency layer. The experimental observation of reflection in the lower plasma density region than the f sub(p)-layer is found to be in qualitative accord with the theoretical reflection, which is obtained from a kinetic theory in an inhomogeneous magnetoplasma. The reflection of the thermal mode is also compared with that of an electromagnetic mode at the f sub(p)-layer. (author)

  9. Electronic traffic signs: Reflecting upon its transition

    Energy Technology Data Exchange (ETDEWEB)

    Arbaiza Martin, A.E.; Alba, A.L.; Hernando Mazon, A.; Blanch Mico, M.T.

    2016-07-01

    In our days we face a fundamental issue concerning road signs. We may display contents in vertical and horizontal format (static signs, variable message signs, road markings), either on a post, a gantry or a dashboard. And we foresee a coming age where the excellent matrix resolution of painted signs will be truly approached by the resolution of full matrix displays. But we also risk a babel context threatening the universal approach encouraged by international catalogues as the 1968 Convention (ECE/TRANS/196, 2007). And the fundamental risk comes from our decisions regarding how the transition from the contents and formats displayed on static message signs to the ones displayed on electronic signs (in gantries or dashboards) should be. Our work explores this issue specifically, considering the transition from Advance Direction Signs (static message signs, class G, 1 in the 1968 Convention) to what could be termed Advance Location Signs (signs concerning the location of variable events with regards to certain landmarks) developed as an adaptation of the G, 1 class to electronic traffic signs.(Author)

  10. Do portfolios have a future?

    Science.gov (United States)

    Driessen, Erik

    2017-03-01

    While portfolios have seen an unprecedented surge in popularity, they have also become the subject of controversy: learners often perceive little gain from writing reflections as part of their portfolios; scholars question the ethics of such obligatory reflection; and students, residents, teachers and scholars alike condemn the bureaucracy surrounding portfolio implementation in competency-based education. It could be argued that mass adoption without careful attention to purpose and format may well jeopardize portfolios' viability in health sciences education. This paper explores this proposition by addressing the following three main questions: (1) Why do portfolios meet with such resistance from students and teachers, while educators love them?; (2) Is it ethical to require students to reflect and then grade their reflections?; (3) Does competency-based education empower or hamper the learner during workplace-based learning? Twenty-five years of portfolio reveal a clear story: without mentoring, portfolios have no future and are nothing short of bureaucratic hurdles in our competency-based education programs. Moreover, comprehensive portfolios, which are integrated into the curriculum and much more diverse in content than reflective portfolios, can serve as meaningful patient charts, providing doctor and patient with useful information to discuss well-being and treatment. In this sense, portfolios are also learner charts that comprehensively document progress in a learning trajectory which is lubricated by meaningful dialogue between learner and mentor in a trusting relationship to foster learning. If we are able to make such comprehensive and meaningful use of portfolios, then, yes, portfolios do have a bright future in medical education.

  11. Tensions in mentoring medical students toward self-directed and reflective learning in a longitudinal portfolio-based mentoring system - An activity theory analysis.

    Science.gov (United States)

    Heeneman, Sylvia; de Grave, Willem

    2017-04-01

    In medical education, students need to acquire skills to self-direct(ed) learning (SDL), to enable their development into self-directing and reflective professionals. This study addressed the mentor perspective on how processes in the mentor-student interaction influenced development of SDL. n = 22 mentors of a graduate-entry medical school with a problem-based curriculum and longitudinal mentoring system were interviewed (n = 1 recording failed). Using activity theory (AT) as a theoretical framework, thematic analysis was applied to the interview data to identify important themes. Four themes emerged: centered around the role of the portfolio, guiding of students' SDL in the context of assessment procedures, mentor-role boundaries and longitudinal development of skills by both the mentor and mentee. Application of AT showed that in the interactions between themes tensions or supportive factors could emerge for activities in the mentoring process. The mentors' perspective on coaching and development of reflection and SDL of medical students yielded important insights into factors that can hinder or support students' SDL, during a longitudinal mentor-student interaction. Coaching skills of the mentor, the interaction with a portfolio and the context of a mentor community are important factors in a longitudinal mentor-student interaction that can translate to students' SDL skills.

  12. The teaching portfolio as a professional development tool for anaesthetists.

    Science.gov (United States)

    Sidhu, N S

    2015-05-01

    A teaching portfolio (TP) is a document containing a factual description of a teacher's teaching strengths and accomplishments, allowing clinicians to display them for examination by others. The primary aim of a TP is to improve quality of teaching by providing a structure for self-reflection, which in turn aids professional development in medical education. Contents typically include a personal statement on teaching, an overview of teaching accomplishments and activities, feedback from colleagues and learners, a reflective component and some examples of teaching material. Electronic portfolios are more portable and flexible compared to paper portfolios. Clinicians gain the most benefit from a TP when it is used as a tool for self-reflection of their teaching practice and not merely as a list of activities and achievements. This article explains why and how anaesthetists might use a TP as a tool for professional development in medical education.

  13. "Contagion" between the emerging and developed capital markets: empirical evidence and reflections on the international portfolio diversification

    Directory of Open Access Journals (Sweden)

    Wagner Moura Lamounier

    2008-10-01

    Full Text Available In this research, we analyzed the short and long term interdependence and relationship between the stock indices of the major emerging capital markets and the major developed markets for the period 1995-2005. The aim was to verify the existence and the dynamics of the “contagion” between the markets, or if the occurrence of crises and changes in the behavior of a market would have impacts on the behavior of the others. In the development of the work, we applied the methodology of the Vector Error Correction Model (VEC. We found the presence of cointegrating relationships between the markets analyzed, but was able to see that, despite being cointegrated markets, investors could benefit from international diversification of portfolios. That’s because the speed of adjustment of the long-term ratio of cointegration between the markets was low for the period analyzed. Accordingly, investors would have the opportunity to reduce risk by diversifying their portfolios.

  14. Portfolios in Saudi medical colleges

    Science.gov (United States)

    Fida, Nadia M.; Shamim, Muhammad S.

    2016-01-01

    Over recent decades, the use of portfolios in medical education has evolved, and is being applied in undergraduate and postgraduate programs worldwide. Portfolios, as a learning process and method of documenting and assessing learning, is supported as a valuable tool by adult learning theories that stress the need for learners to be self-directed and to engage in experiential learning. Thoughtfully implemented, a portfolio provides learning experiences unequaled by any single learning tool. The credibility (validity) and dependability (reliability) of assessment through portfolios have been questioned owing to its subjective nature; however, methods to safeguard these features have been described in the literature. This paper discusses some of this literature, with particular attention to the role of portfolios in relation to self-reflective learning, provides an overview of current use of portfolios in undergraduate medical education in Saudi Arabia, and proposes research-based guidelines for its implementation and other similar contexts. PMID:26905344

  15. Teaching Portfolio

    DEFF Research Database (Denmark)

    Pedersen, Christian Fischer

    The present teaching portfolio has been submitted for evaluation in partial fulfillment of the requirements of the teacher training programme for Assistant Professors at Department of Engineering, Aarhus University, Denmark.......The present teaching portfolio has been submitted for evaluation in partial fulfillment of the requirements of the teacher training programme for Assistant Professors at Department of Engineering, Aarhus University, Denmark....

  16. Customer portfolios

    DEFF Research Database (Denmark)

    Clarke, Ann Højbjerg; Freytag, Per Vagn; Zolkiewski, Judith

    2017-01-01

    gives managers a tool to help to cope with the dynamic aspects of the customer portfolio. Recognition of the importance of communication to the process, the development of trust and the role of legitimacy also provides areas that managers can focus upon in their relationship management processes......Purpose The purpose of this paper is to extend the discussion about customer portfolios beyond simple identification of models and how they can be used for balanced resource allocation to a discussion about how portfolios should take into account views from relationship partners and how they should...... that helps improve the understanding of how customer portfolio models can actually be applied from a relational perspective. Findings The key aspects of the conceptual framework relate to how alignment of the relationships in the portfolio is achieved. Critical to this are the interaction spaces...

  17. Portfolio Management

    Science.gov (United States)

    Duncan, Sharon L.

    2011-01-01

    Enterprise Business Information Services Division (EBIS) supports the Laboratory and its functions through the implementation and support of business information systems on behalf of its business community. EBIS Five Strategic Focus Areas: (1) Improve project estimating, planning and delivery capability (2) Improve maintainability and sustainability of EBIS Application Portfolio (3) Leap forward in IT Leadership (4) Comprehensive Talent Management (5) Continuous IT Security Program. Portfolio Management is a strategy in which software applications are managed as assets

  18. A Reflection on Aging: A Portfolio of Change in Attitudes toward Geriatric Patients during a Clerkship Rotation

    Science.gov (United States)

    Del Duca, Danny; Duque, Gustavo

    2006-01-01

    The process of students' evaluation in medical schools has changed from a tutor-led evaluation system based on students' performance to a student-based evaluation that involves self-reflection and their level of change in skills and attitudes. At the McGill University Division of Geriatric Medicine, we developed an innovative system of evaluation…

  19. Reflection of attosecond x-ray free electron laser pulses

    International Nuclear Information System (INIS)

    Hau-Riege, Stefan P.; Chapman, Henry N.

    2007-01-01

    In order to utilize hard x-ray free electron lasers (XFEL's) when they are extended to attosecond pulse lengths, it is necessary to choose optical elements with minimal response time. Specular grazing-incidence optics made of low-Z materials are popular candidates for reflectors since they are likely to withstand x-ray damage and provide sufficiently large reflectivities. Using linear-optics reflection theory, we calculated the transient reflectivity of a delta-function electric pulse from a homogenous semi-infinite medium as a function of angle of incidence for s- and p-polarized light. We specifically considered the pulse response of beryllium, diamond, silicon carbide, and silicon, all of which are of relevance to the XFEL's that are currently being built. We found that the media emit energy in a damped oscillatory way, and that the impulse-response times are shorter than 0.3 fs for normal incidence. For grazing incidence, the impulse-response time is substantially shorter, making grazing-incidence mirrors a good choice for deep subfemtosecond reflective optics

  20. Optimal Portfolio Rebalancing Strategy : Evidence from Finnish Stocks

    OpenAIRE

    Savage, Akinwunmi

    2010-01-01

    Portfolio rebalancing is an established concept in portfolio management and investing generally. Assets within a portfolio have different return and risk prospects, and this inevitably leads them to drift away from their initial allocation weights overtime. Portfolio rebalancing is arguably the only method by which such assets can be reset to their initial weights, thus ensuring the portfolio reflects the risk appetite of the investor. Like many other concepts and practices in finance, portfo...

  1. Switching portfolios.

    Science.gov (United States)

    Singer, Y

    1997-08-01

    A constant rebalanced portfolio is an asset allocation algorithm which keeps the same distribution of wealth among a set of assets along a period of time. Recently, there has been work on on-line portfolio selection algorithms which are competitive with the best constant rebalanced portfolio determined in hindsight (Cover, 1991; Helmbold et al., 1996; Cover and Ordentlich, 1996). By their nature, these algorithms employ the assumption that high returns can be achieved using a fixed asset allocation strategy. However, stock markets are far from being stationary and in many cases the wealth achieved by a constant rebalanced portfolio is much smaller than the wealth achieved by an ad hoc investment strategy that adapts to changes in the market. In this paper we present an efficient portfolio selection algorithm that is able to track a changing market. We also describe a simple extension of the algorithm for the case of a general transaction cost, including the transactions cost models recently investigated in (Blum and Kalai, 1997). We provide a simple analysis of the competitiveness of the algorithm and check its performance on real stock data from the New York Stock Exchange accumulated during a 22-year period. On this data, our algorithm outperforms all the algorithms referenced above, with and without transaction costs.

  2. Characteristic losses of electrons energy under reflection from leadsilicate glasses

    International Nuclear Information System (INIS)

    Gusarov, A.I.; Mashkov, V.A.; Pronin, V.P.; Tyutikov, A.M.

    1986-01-01

    The spectra of characteristic losses of energy (CLE) for the case of electron reflection from the surface of leadsilicate glasses of the composition xPbOx(1-x)SiO 2 , depending on molar concentration of lead oxide x, has been calculated for the first time. It is shown that the given model of glass energy structure permits to describe correctly general behaviour of CLE spectrum. However, the energy of plasma maximum measured experimentally remains approximately constant. The behaviour can be conditioned by ω 0 dependence on x[4], which has not been taken into account, and (or) by a slower change in ΔE, than it has been assumed. Further refining of theory and experiment is required to solve the problem

  3. Analysis of contaminants on electronic components by reflectance FTIR spectroscopy

    International Nuclear Information System (INIS)

    Griffith, G.W.

    1982-09-01

    The analysis of electronic component contaminants by infrared spectroscopy is often a difficult process. Most of the contaminants are very small, which necessitates the use of microsampling techniques. Beam condensers will provide the required sensitivity but most require that the sample be removed from the substrate before analysis. Since it can be difficult and time consuming, it is usually an undesirable approach. Micro ATR work can also be exasperating, due to the difficulty of positioning the sample at the correct place under the ATR plate in order to record a spectrum. This paper describes a modified reflection beam condensor which has been adapted to a Nicolet 7199 FTIR. The sample beam is directed onto the sample surface and reflected from the substrate back to the detector. A micropositioning XYZ stage and a close-focusing telescope are used to position the contaminant directly under the infrared beam. It is possible to analyze contaminants on 1 mm wide leads surrounded by an epoxy matrix using this device. Typical spectra of contaminants found on small circuit boards are included

  4. The primary assessment tool at Philips electronics : capturing real options and organizational risk in technology portfolio management

    NARCIS (Netherlands)

    Lint, L.J.O.

    2000-01-01

    I develop an extended scoring approach to build a balanced portfolio of new technology projects under uncertainty at early stages of development. My contribution is twofold. First, I show how the tool incorporates the option approach to decision making to create contingent claims on future market

  5. Study of optical and electronic properties of nickel from reflection electron energy loss spectra

    Science.gov (United States)

    Xu, H.; Yang, L. H.; Da, B.; Tóth, J.; Tőkési, K.; Ding, Z. J.

    2017-09-01

    We use the classical Monte Carlo transport model of electrons moving near the surface and inside solids to reproduce the measured reflection electron energy-loss spectroscopy (REELS) spectra. With the combination of the classical transport model and the Markov chain Monte Carlo (MCMC) sampling of oscillator parameters the so-called reverse Monte Carlo (RMC) method was developed, and used to obtain optical constants of Ni in this work. A systematic study of the electronic and optical properties of Ni has been performed in an energy loss range of 0-200 eV from the measured REELS spectra at primary energies of 1000 eV, 2000 eV and 3000 eV. The reliability of our method was tested by comparing our results with the previous data. Moreover, the accuracy of our optical data has been confirmed by applying oscillator strength-sum rule and perfect-screening-sum rule.

  6. Universal portfolios in stochastic portfolio theory

    OpenAIRE

    Wong, Ting-Kam Leonard

    2015-01-01

    Consider a family of portfolio strategies with the aim of achieving the asymptotic growth rate of the best one. The idea behind Cover's universal portfolio is to build a wealth-weighted average which can be viewed as a buy-and-hold portfolio of portfolios. When an optimal portfolio exists, the wealth-weighted average converges to it by concentration of wealth. Working under a discrete time and pathwise setup, we show under suitable conditions that the distribution of wealth in the family sati...

  7. Electronic and optical properties of Fe, Pd, and Ti studied by reflection electron energy loss spectroscopy

    International Nuclear Information System (INIS)

    Tahir, Dahlang; Kraaer, Jens; Tougaard, Sven

    2014-01-01

    We have studied the electronic and optical properties of Fe, Pd, and Ti by reflection electron energy-loss spectroscopy (REELS). REELS spectra recorded for primary energies in the range from 300 eV to 10 keV were corrected for multiple inelastically scattered electrons to determine the effective inelastic-scattering cross section. The dielectric functions and optical properties were determined by comparing the experimental inelastic-electron scattering cross section with a simulated cross section calculated within the semi-classical dielectric response model in which the only input is Im(−1/ε) by using the QUEELS-ε(k,ω)-REELS software package. The complex dielectric functions ε(k,ω), in the 0–100 eV energy range, for Fe, Pd, and Ti were determined from the derived Im(−1/ε) by Kramers-Kronig transformation and then the refractive index n and extinction coefficient k. The validity of the applied model was previously tested and found to give consistent results when applied to REELS spectra at energies between 300 and 1000 eV taken at widely different experimental geometries. In the present paper, we provide, for the first time, a further test on its validity and find that the model also gives consistent results when applied to REELS spectra in the full range of primary electron energies from 300 eV to 10000 eV. This gives confidence in the validity of the applied method.

  8. Using Facebook-Based e-Portfolio in ESL Writing Classrooms: Impact and Challenges

    Science.gov (United States)

    Barrot, Jessie S.

    2016-01-01

    In English as a second language (ESL) writing pedagogy, much attention has been given to electronic portfolio (e-portfolio) assessment via social networking sites. However, little is known about how Facebook can be used as an e-portfolio platform. Hence, this paper describes the impact of Facebook-based e-portfolio on ESL students' writing…

  9. Quantifying Reflection

    DEFF Research Database (Denmark)

    Alcock, Gordon Lindsay

    2013-01-01

    ´ These are all based on Blooms taxonomy and levels of competence and form a major part of individual student and group learning portfolios. Key Words :Project-Based learning, Reflective Portfolios, Self assessment, Defining learning gains, Developing learning strategies , Reflections on and for learning....... It contrasts the students’ self-assessment in a range of ‘product’ skills such as Revit, Structural Design, Mathematics of construction, Technical Installations; as well as ‘process’ competencies such as ‘Working in a team’, Sharing knowledge, Maintaining a portfolio and Reflecting ON learning and FOR learning......This paper documents 1st semester student reflections on “learning to learn” in a team-based PBL environment with quantitative and qualitative student reflective feedback on the learning gains of 60 Architectural Technology and Construction Management students at VIA University College, Denmark...

  10. Using E-Learning Portfolio Technology To Support Visual Art Learning

    Directory of Open Access Journals (Sweden)

    Greer Jones-Woodham

    2009-08-01

    Full Text Available Inspired by self-directed learning (SDL theories, this paper uses learning portfolios as a reflective practice to improve student learning and develop personal responsibility, growth and autonomy in learning in a Visual Arts course. Students use PowerPoint presentations to demonstrate their concepts by creating folders that are linked to e-portfolios on the University website. This paper establishes the role of learning e-portfolios to improve teaching and learning as a model of reflection, collaboration and documentation in the making of art as a self-directed process. These portfolios link students' creative thinking to their conceptual frameworks. They also establish a process of inquiry using journals to map students' processes through their reflections and peer feedback. This practice argues that learning e-portfolios in studio art not only depends on a set of objectives whose means are justified by an agreed end but also depends on a practice that engages students' reflection about their actions while in their art- making practice. Using the principles of the maker as the intuitive and reflective practitioner, the making as the process in which the learning e-portfolios communicate the process and conceptual frameworks of learning and the eventual product, and the made as evidence of that learning in light of progress made, this paper demonstrates that learning-in-action and reflecting-in and-on-action are driven by self-direction. With technology, students bring their learning context to bear with the use of SDL. Students' use of PowerPoint program technology in making their portfolios is systematic and builds on students' competencies as this process guides students' beliefs and actions about their work that is based on theory and concepts in response to a visual culture that is Trinidad and Tobago. Students' self–directed art-making process as a self directed learning, models the process of articulated learning. Communicating about

  11. Optical observations of Magnetosphere-Ionosphere coupling: Inter-hemispheric electron reflections within pulsating aurora

    Science.gov (United States)

    Samara, M.; Michell, R.; Khazanov, G. V.; Grubbs, G. A., II

    2017-12-01

    Magnetosphere-Ionosphere coupling is exhibited in reflected primary and secondary electrons which constitute the second step in the formation of the total precipitating electron distribution. While they have largely been missing from the current theoretical studies of particle precipitation, ground based observations point to the existence of a reflected electron population. We present evidence that pulsating aurora is caused by electrons bouncing back and forth between the two hemispheres. This means that these electrons are responsible for some of the total light in the aurora, a possibility that has largely been ignored in theoretical models. Pulsating auroral events imaged optically at high time resolution present direct observational evidence in agreement with the inter-hemispheric electron bouncing predicted by the SuperThermal Electron Trans-port (STET) model. Immediately following each of the `pulsation-on' times are equally spaced, and subsequently fainter pulsations, which can be explained by the primary precipitating electrons reflecting upwards from the ionosphere, traveling to the opposite hemisphere, and reflecting upwards again. The high time-resolution of these data, combined with the short duration of the `pulsation-on' time ( 1 s) and the relatively long spacing between pulsations ( 6 to 9 s) made it possible to observe the faint optical pulses caused by the reflected electrons coming from the opposite hemisphere. These results are significant and have broad implications because they highlight that the formation of the auroral electron distributions within regions of diffuse and pulsating aurora contain contributions from reflected primary and secondary electrons. These processes can ultimately lead to larger fluxes than expected when considering only the primary injection of magnetospheric electrons.

  12. Robust Active Portfolio Management

    National Research Council Canada - National Science Library

    Erdogan, E; Goldfarb, D; Iyengar, G

    2006-01-01

    ... on the portfolio beta, and limits on cash and industry exposure. We show that the optimal portfolios can be computed by solving second-order cone programs -- a class of optimization problems with a worst case complexity (i.e...

  13. Use of Portfolios by Medical Students: Significance of Critical Thinking

    Directory of Open Access Journals (Sweden)

    Samy A. Azer

    2008-07-01

    Full Text Available Portfolios have been used in the medical curriculum to evaluate difficult-to-assess areas such as students' attitudes, professionalism and teamwork. However, their use early in a problem-based learning (PBL course to foster deep learning and enhance students' self-directed learning has not been adequately studied. The aims of this paper are to: (1 understand the uses of portfolios and the rationale for using reflection in the early years of a PBL curriculum; (2 discuss how to introduce portfolios and encourage students' critical thinking skills, not just reflection; and (3 provide students with tips that could enhance their skills in constructing good portfolios.

  14. Thermoluminescence, infrared reflectivity and electron paramagnetic resonance properties of hemimorphite

    Energy Technology Data Exchange (ETDEWEB)

    Gallegos, E.A. [Institute of Physics, University of Sao Paulo, Rua do Matao, Travessa R, 187, CEP 05508-900, Sao Paulo, SP (Brazil); Cano, N.F. [Institute of Physics, University of Sao Paulo, Rua do Matao, Travessa R, 187, CEP 05508-900, Sao Paulo, SP (Brazil)], E-mail: nilocano@dfn.if.usp.br; Watanabe, S.; Chubaci, J.F.D. [Institute of Physics, University of Sao Paulo, Rua do Matao, Travessa R, 187, CEP 05508-900, Sao Paulo, SP (Brazil)

    2009-01-15

    Silicate mineral hemimorphite has been investigated concerning its TL, IR and EPR properties. A broad TL peak around 180 deg. C and a weaker and narrower peak around 360 deg. C were found in a sample annealed at 600 deg. C for 1 h and then irradiated. The deconvolution using the CGCD method revealed peaks around 132, 169, 222 and 367 deg. C. The reflectivity measurements showed several bands in the NIR region due to H{sub 2}O, OH and Al-OH complexes. No band was observed in the visible region. The thermal treatments were carried out from {approx}110 to 940 deg. C and dehydration was observed, first causing a diminishing optical absorption in general and the disappearance of water and hydroxyl absorption bands. The EPR spectrum of natural hemimorphite, presented Cu{sup 2+} signals at g = 2.4 and g = 2.1 plus E{sub 1}' signal superposed to Fe{sup 3+} signal around g = 2.0.

  15. Making practice transparent through e-portfolio.

    Science.gov (United States)

    Stewart, Sarah M

    2013-12-01

    Midwives are required to maintain a professional portfolio as part of their statutory requirements. Some midwives are using open social networking tools and processes to develop an e-portfolio. However, confidentiality of patient and client data and professional reputation have to be taken into consideration when using online public spaces for reflection. There is little evidence about how midwives use social networking tools for ongoing learning. It is uncertain how reflecting in an e-portfolio with an audience impacts on learning outcomes. This paper investigates ways in which reflective midwifery practice be carried out using e-portfolio in open, social networking platforms using collaborative processes. Using an auto-ethnographic approach I explored my e-portfolio and selected posts that had attracted six or more comments. I used thematic analysis to identify themes within the textual conversations in the posts and responses posted by readers. The analysis identified that my collaborative e-portfolio had four themes: to provide commentary and discuss issues; to reflect and process learning; to seek advice, brainstorm and process ideas for practice, projects and research, and provide evidence of professional development. E-portfolio using open social networking tools and processes is a viable option for midwives because it facilitates collaborative reflection and shared learning. However, my experience shows that concerns about what people think, and client confidentiality does impact on the nature of open reflection and learning outcomes. I conclude this paper with a framework for managing midwifery statutory obligations using online public spaces and social networking tools. Copyright © 2013 Australian College of Midwives. Published by Elsevier Ltd. All rights reserved.

  16. Electronic eye occluder with time-counting and reflection control

    Science.gov (United States)

    Karitans, V.; Ozolinsh, M.; Kuprisha, G.

    2008-09-01

    In pediatric ophthalmology 2 - 3 % of all the children are impacted by a visual pathology - amblyopia. It develops if a clear image isn't presented to the retina during an early stage of the development of the visual system. A common way of treating this pathology is to cover the better-seeing eye to force the "lazy" eye to learn seeing. However, children are often reluctant to wear such an occluder because they are ashamed or simply because they find it inconvenient. This fact requires to find a way how to track the regime of occlusion because results of occlusion is a hint that the actual regime of occlusion isn't that what the optometrist has recommended. We design an electronic eye occluder that allows to track the regime of eye occlusion. We employ real-time clock DS1302 providing time information from seconds to years. Data is stored in the internal memory of the CPU (EEPROM). The MCU (PIC16F676) switches on only if a mechanical switch is closed and temperature has reached a satisfactory level. The occlusion is registered between time moments when the infrared signal appeared and disappeared.

  17. Portfolio at Tertiary Level – Lifelong Learning Tool

    Directory of Open Access Journals (Sweden)

    Galina Kavaliauskienė

    2011-04-01

    Full Text Available The use of electronic language portfolios has been preferable to the use of common paper portfolios for ease of application – there is no need for accumulating a number of files of written papers, which solves the problem of storing space and, to some extent, helps reduce students’ and teachers’ workload.The study investigated learners’ perceptions of employing electronic language portfolios for conducting various assignments in English for Specific Purposes. The research involved university students of different specializations. Learners’ experience of employing portfolios and opinions on their benefits for improving language skills have been analyzed and statistically treated using SPSS software. The results show that students are positive about application of electronic portfolios in ESP classes. The use of online portfolios for various assignments helps teachers foster students’ learning, encourages critical thinking, develops creativity, motivates learners to use digital technology, encourages collaboration of learners, and in the long run, leads to lifelong learning.

  18. Comprehensive Education Portfolio with a Career Focus

    Science.gov (United States)

    Kruger, Evonne J.; Holtzman, Diane M.; Dagavarian, Debra A.

    2013-01-01

    There are many types of student portfolios used within academia: the prior learning portfolio, credentialing portfolio, developmental portfolio, capstone portfolio, individual course portfolio, and the comprehensive education portfolio. The comprehensive education portfolio (CEP), as used by the authors, is a student portfolio, developed over…

  19. Portfólio reflexivo: uma proposta de ensino e aprendizagem orientada por competências Reflective portfolio: a proposal for teaching and learning geared on competencies

    Directory of Open Access Journals (Sweden)

    Glauce Dias da Costa

    2013-06-01

    Full Text Available O objetivo deste artigo é analisar a experiência de construção coletiva de portfólios como método de ensino-aprendizagem na disciplina de Políticas de Saúde, identificando as competências desenvolvidas pelos estudantes. Pesquisa qualitativa, cuja coleta e tratamento dos dados se deram por meio da análise documental (34 portfólios e temática, respectivamente. Consideraram-se as competências Aprender a ser e Aprender a conviver e a trabalhar juntos, segundo as proposições do informe da Unesco para Educação. A formação de indivíduos críticos-reflexivos, proporcionada pelo portfólio, foi especialmente verificada quando os estudantes relataram a transformação da visão negativa que tinham sobre o sistema de saúde - uma política ineficiente e precária - para uma visão positiva - uma política que tem como princípios a equidade, a integralidade e a universalidade. Esse processo de transformação crítica foi decorrente do exercício das habilidades de comunicação, gestão da informação (busca, seleção, análises e avaliação das informações, liderança, cooperação e relações humanas (trabalho em equipe, ética e reconhecimento da diversidade, além de competências pessoais (gestão do tempo, responsabilidade e planejamento, habilidades estas importantes na formação de profissionais comprometidos com a política nacional de saúde.This article seeks to analyze the experience of collective construction of portfolios as a teaching-learning method in the discipline of Health Policy, identifying the competencies developed by students. Qualitative research, whose collection and data processing were conducted by means of documental and thematic analysis of 34 portfolios. The "Learning to be" and "Learning to live and work together" competencies were considered according to the proposals of the UNESCO report for Education. The training of critical-reflexive individuals, provided by the portfolio, was particularly

  20. Concurrent credit portfolio losses.

    Science.gov (United States)

    Sicking, Joachim; Guhr, Thomas; Schäfer, Rudi

    2018-01-01

    We consider the problem of concurrent portfolio losses in two non-overlapping credit portfolios. In order to explore the full statistical dependence structure of such portfolio losses, we estimate their empirical pairwise copulas. Instead of a Gaussian dependence, we typically find a strong asymmetry in the copulas. Concurrent large portfolio losses are much more likely than small ones. Studying the dependences of these losses as a function of portfolio size, we moreover reveal that not only large portfolios of thousands of contracts, but also medium-sized and small ones with only a few dozens of contracts exhibit notable portfolio loss correlations. Anticipated idiosyncratic effects turn out to be negligible. These are troublesome insights not only for investors in structured fixed-income products, but particularly for the stability of the financial sector. JEL codes: C32, F34, G21, G32, H81.

  1. The ePortfolio as an educational resource and its impact on job search

    Directory of Open Access Journals (Sweden)

    Monika Ciesielkiewicz

    2015-09-01

    Full Text Available This paper intends to make evident that the ePortfolio is an effective and cuttingedge learning and evaluation tool, as well as a multimedia curriculum vitae that can be sent out to future employers. It can be used to present, document, reflect on, and promote students’ skills, credentials, certificates and diverse formal and informal experiences in a structured, wellorganized and marketable way. Different types and parts of ePortfolio will be explained in this paper and it will be demonstrated that ePortfolio teaches a ranges of strategies that facilitates learning, as well as the acquisition of skills needed in a workplace. Besides, real examples of ePortfolio, both american and spanish version, developed by students in both countries will be presented. Finally, the results of a survey carried out among fifty two human resources directors will be analyzed. This paper will demonstrate that the electronic portfolio can be considered a very useful and effective job search tool that can count with a significant approval in the business world.

  2. Using an ePortfolio System as an Electronic Laboratory Notebook in Undergraduate Biochemistry and Molecular Biology Practical Classes

    Science.gov (United States)

    Johnston, Jill; Kant, Sashi; Gysbers, Vanessa; Hancock, Dale; Denyer, Gareth

    2014-01-01

    Despite many apparent advantages, including security, back-up, remote access, workflow, and data management, the use of electronic laboratory notebooks (ELNs) in the modern research laboratory is still developing. This presents a challenge to instructors who want to give undergraduate students an introduction to the kinds of data curation and…

  3. Portfolio : Theory and Practice of the Pedagogical Methods Course for Assistant Professors at Aalborg University

    DEFF Research Database (Denmark)

    Hansen, Søren

    2002-01-01

    workshops and self-studies. Finally, a portfolio is used as a tool for self-reflection. Further the portfolio is used as documentation for experience with teaching, the reflections on action and progression in teaching practice. In this discussion paper, I will reflect on the effect of the course...... and question whether it is appropriate to use a written portfolio for self-reflection and documentation of competences?...

  4. Observation of strong reflection of electron waves exiting a ballistic channel at low energy

    Energy Technology Data Exchange (ETDEWEB)

    Vaz, Canute I.; Campbell, Jason P.; Ryan, Jason T.; Gundlach, David; Cheung, Kin. P., E-mail: Kin.Cheung@NIST.gov [National Institute of Standards and Technology, Gaithersburg, MD 20899-8120 (United States); Liu, Changze [National Institute of Standards and Technology, Gaithersburg, MD 20899-8120 (United States); Institute of Microelectronics, Peking University, Beijing 100871 (China); Southwick, Richard G. [National Institute of Standards and Technology, Gaithersburg, MD 20899-8120 (United States); IBM Research, Albany, NY 12205 (United States); Oates, Anthony S. [Taiwan Semiconductor Manufacturing Corporation, Hsinchu 30844, Taiwan (China); Huang, Ru [Institute of Microelectronics, Peking University, Beijing 100871 (China)

    2016-06-15

    Wave scattering by a potential step is a ubiquitous concept. Thus, it is surprising that theoretical treatments of ballistic transport in nanoscale devices, from quantum point contacts to ballistic transistors, assume no reflection even when the potential step is encountered upon exiting the device. Experiments so far seem to support this even if it is not clear why. Here we report clear evidence of coherent reflection when electron wave exits the channel of a nanoscale transistor and when the electron energy is low. The observed behavior is well described by a simple rectangular potential barrier model which the Schrodinger’s equation can be solved exactly. We can explain why reflection is not observed in most situations but cannot be ignored in some important situations. Our experiment also represents a direct measurement of electron injection velocity - a critical quantity in nanoscale transistors that is widely considered not measurable.

  5. Professional Doctorate in Health Psychology Thesis Portfolio : Adolescents' views of the electronic cigarette : a new gateway to addiction?

    OpenAIRE

    Clarke, Tilean Naomi

    2015-01-01

    Background:\\ud In the UK alone it is estimated that there are 2.1 million adult electronic cigarette (e-cigarette) users (Action on Smoking and Health, 2014). Introduced to the UK in 2006, ecigarette use has grown rapidly from 700,000 users in 2012 (Kmietowicz, 2014). Given that smoking initiation begins for the most part during adolescence, it is debatable as to whether the e-cigarette could be a gateway into addiction for adolescent non-smokers. This study examined awareness and use of the ...

  6. Using the Teaching Portfolio to Anticipate Programmatic Assessment

    Science.gov (United States)

    Price, Kenneth R.

    2013-01-01

    Portfolios have long been a staple in professional writing courses: both in employment materials assignments and in entire classes that ask students to reflect on their experiential learning. Portfolios may also be used effectively in business communication teaching methods courses. This article details the justification and methodology for having…

  7. Validation of Competencies in E-Portfolios: A Qualitative Analysis

    Science.gov (United States)

    Zawacki-Richter, Olaf; Hanft, Anke; Baecker, Eva Maria

    2011-01-01

    This paper uses the example of an Internet-based advanced studies course to show how the portfolio method, as a competence-based form of examination, can be integrated in a blended learning design. Within the framework of a qualitative analysis of project portfolios, we examined which competencies are documented and how students reflected on their…

  8. The Role of e-Portfolios in Supporting Productive Learning

    Science.gov (United States)

    Yang, Min; Tai, Mui; Lim, Cher Ping

    2016-01-01

    e-Portfolios are a form of authentic assessment with formative functions that include showcasing and sharing learning artifacts, documenting reflective learning processes, connecting learning across various stages and enabling frequent feedback for improvements. This paper examines how e-portfolios take up these formative roles to support…

  9. 2010-11 Research Portfolio: Research & Development Division

    Science.gov (United States)

    Educational Testing Service, 2010

    2010-01-01

    This document describes the breadth of the research that the ETS (Educational Testing Service) Research & Development division is conducting in 2010. This portfolio will be updated in early 2011 to reflect changes to existing projects and new projects that were added after this document was completed. The research described in this portfolio falls…

  10. Can One Portfolio Measure the Six ACGME General Competencies?

    Science.gov (United States)

    Jarvis, Robert M.; O'Sullivan, Patricia S.; McClain, Tina; Clardy, James A.

    2004-01-01

    Objective: To determine that portfolios, useable by any program, can provide needed evidence of resident performance within the ACGME general competencies. Methods: Eighteen residents constructed portfolios with selected entries from thirteen psychiatric skills. Two raters assessed whether entries reflected resident performance within the general…

  11. Multi-technique application of a double reflection electron emission microscope

    International Nuclear Information System (INIS)

    Jian-liang, J.; Bao-gui, S.; Guo-jun, Z

    2002-01-01

    Full text: In this paper the results acquired with the most recently developed double reflection electron emission microscope applied in different imaging modes are presented. The novel illumination system is based on a (100)-oriented single crystalline W wire electron microreflector and an electron gun placed in the back focal plane of the immersion objective. After being elastically reflected from the W tip surface, the primary electrons of energy ranging from 1 to 6 keV are decelerated to the desired impact energy in the range 0 to 200 eV for mirror electron microscopy (MEM), low energy electron emission microscopy (LEEM) and low energy electron diffraction (LEED) modes or to 5 keV for the secondary electron imaging mode. Photoelectron emission microscopy (PEEM), MEM, LEEM, secondary images of Pd/Si(111) and a set of selected area LEED patterns of the W(100) surface taken at energies ranging from 5 to 40 eV are presented for the first time. Copyright (2002) Australian Society for Electron Microscopy Inc

  12. Decentralized portfolio management

    OpenAIRE

    Coutinho, Paulo; Tabak, Benjamin Miranda

    2003-01-01

    We use a mean-variance model to analyze the problem of decentralized portfolio management. We find the solution for the optimal portfolio allocation for a head trader operating in n different markets, which is called the optimal centralized portfolio. However, as there are many traders specialized in different markets, the solution to the problem of optimal decentralized allocation should be different from the centralized case. In this paper we derive conditions for the solutions to be equiva...

  13. [Development of a portfolio for competency-based assessment in a clinical clerkship curriculum].

    Science.gov (United States)

    Roh, HyeRin; Lee, Jong-Tae; Yoon, Yoo Sang; Rhee, Byoung Doo

    2015-12-01

    The purpose of this report was to describe our experience in planning and developing a portfolio for a clinical clerkship curriculum. We have developed a portfolio for assessing student competency since 2007. During an annual workshop on clinical clerkship curricula, clerkship directors from five Paik hospitals of Inje University met to improve the assessment of the portfolio. We generated templates for students to record their activities and reflection and receive feedback. We uploaded these templates to our school's website for students to download freely. Annually, we have held a faculty development seminar and a workshop for portfolio assessment and feedback. Also, we established an orientation program on how to construct a learning portfolio for students. Future actions include creating a ubiquitous portfolio system, extending the portfolio to the entire curriculum, setting up an advisor system, and managing the quality of the portfolio. This study could be helpful for medical schools that plan to improve their portfolio assessment with an outcome-based approach.

  14. Risk modelling in portfolio optimization

    Science.gov (United States)

    Lam, W. H.; Jaaman, Saiful Hafizah Hj.; Isa, Zaidi

    2013-09-01

    Risk management is very important in portfolio optimization. The mean-variance model has been used in portfolio optimization to minimize the investment risk. The objective of the mean-variance model is to minimize the portfolio risk and achieve the target rate of return. Variance is used as risk measure in the mean-variance model. The purpose of this study is to compare the portfolio composition as well as performance between the optimal portfolio of mean-variance model and equally weighted portfolio. Equally weighted portfolio means the proportions that are invested in each asset are equal. The results show that the portfolio composition of the mean-variance optimal portfolio and equally weighted portfolio are different. Besides that, the mean-variance optimal portfolio gives better performance because it gives higher performance ratio than the equally weighted portfolio.

  15. Portfolios in Saudi medical colleges. Why and how?

    Directory of Open Access Journals (Sweden)

    Nadia M. Fida

    2016-03-01

    Full Text Available Over recent decades, the use of portfolios in medical education has evolved, and is being applied in undergraduate and postgraduate programs worldwide. Portfolios, as a learning process and method of documenting and assessing learning, is supported as a valuable tool by adult learning theories that stress the need for learners to be self-directed and to engage in experiential learning. Thoughtfully implemented, a portfolio provides learning experiences unequaled by any single learning tool. The credibility (validity and dependability (reliability of assessment through portfolios have been questioned owing to its subjective nature; however, methods to safeguard these features have been described in the literature. This paper discusses some of this literature, with particular attention to the role of portfolios in relation to self-reflective learning, provides an overview of current use of portfolios in undergraduate medical education in Saudi Arabia, and proposes research-based guidelines for its implementation and other similar contexts.

  16. Quantifying electronic band interactions in van der Waals materials using angle-resolved reflected-electron spectroscopy.

    Science.gov (United States)

    Jobst, Johannes; van der Torren, Alexander J H; Krasovskii, Eugene E; Balgley, Jesse; Dean, Cory R; Tromp, Rudolf M; van der Molen, Sense Jan

    2016-11-29

    High electron mobility is one of graphene's key properties, exploited for applications and fundamental research alike. Highest mobility values are found in heterostructures of graphene and hexagonal boron nitride, which consequently are widely used. However, surprisingly little is known about the interaction between the electronic states of these layered systems. Rather pragmatically, it is assumed that these do not couple significantly. Here we study the unoccupied band structure of graphite, boron nitride and their heterostructures using angle-resolved reflected-electron spectroscopy. We demonstrate that graphene and boron nitride bands do not interact over a wide energy range, despite their very similar dispersions. The method we use can be generally applied to study interactions in van der Waals systems, that is, artificial stacks of layered materials. With this we can quantitatively understand the 'chemistry of layers' by which novel materials are created via electronic coupling between the layers they are composed of.

  17. Reflections

    Directory of Open Access Journals (Sweden)

    Joanne Embree

    2001-01-01

    Full Text Available Ideally, editorials are written one to two months before publication in the Journal. It was my turn to write this one. I had planned to write the first draft the evening after my clinic on Tuesday, September 11. It didn't get done that night or during the next week. Somehow, the topic that I had originally chosen just didn't seem that important anymore as I, along my friends and colleagues, reflected on the changes that the events of that day were likely to have on our lives.

  18. An Electronic Patch for Wearable Health Monitoring by Reflectance Pulse Oximetry

    DEFF Research Database (Denmark)

    Haahr, Rasmus Grønbek; Duun, Sune Bro; Toft, Mette H.

    2012-01-01

    photodiode to enable low power consumption by the light emitting components. The Electronic Patch has a disposable part of soft adhesive hydrocolloid polymer and a reusable part of hard polylaurinlactam. The disposable part contains the battery. The reusable part contains the reflectance pulse oximetry...

  19. Portfolio use and practices in US colleges and schools of pharmacy.

    Science.gov (United States)

    Skrabal, Maryann Z; Turner, Paul D; Jones, Rhonda M; Tilleman, Jennifer A; Coover, Kelli L

    2012-04-10

    To identify the prevalence of portfolio use in US pharmacy programs, common components of portfolios, and advantages of and limitations to using portfolios. A cross-sectional electronic survey instrument was sent to experiential coordinators at US colleges and schools of pharmacy to collect data on portfolio content, methods, training and resource requirements, and benefits and challenges of portfolio use. Most colleges and schools of pharmacy (61.8%) use portfolios in experiential courses and the majority (67.1%) formally assess them, but there is wide variation regarding content and assessment. The majority of respondents used student portfolios as a formative evaluation primarily in the experiential curriculum. Although most colleges and schools of pharmacy have a portfolio system in place, few are using them to fulfill accreditation requirements. Colleges and schools need to carefully examine the intended purpose of their portfolio system and follow-through with implementation and maintenance of a system that meets their goals.

  20. PSN: Portfolio Social Network

    DEFF Research Database (Denmark)

    Cortes, Jordi Magrina; Nizamani, Sarwat; Memon, Nasrullah

    2014-01-01

    In this paper we present a web-based information system which is a portfolio social network (PSN) that provides solutions to the recruiters and job seekers. The proposed system enables users to create portfolio so that he/she can add his specializations with piece of code if any specifically...

  1. Households' portfolio choices

    NARCIS (Netherlands)

    Hochgürtel, S.

    1998-01-01

    This thesis presents four topics on households' portfolio choices. Empirically, households do not hold well-diversified wealth portfolios. In particular, they refrain from putting their savings into risky assets. We explore several ways that might help explaining this observation. Using Dutch

  2. Portfolio i erhvervsuddannelserne

    DEFF Research Database (Denmark)

    2008-01-01

    Materialet kombinerer korte film med introducerende tekster og belyser fra forskellige vinkler, hvordan portfolio kan bruges som evalueringsmetode i erhvervsuddannelserne. Udgiver: Undervisningsministeriet Udgivelsessted: Pub.uvm.dk......Materialet kombinerer korte film med introducerende tekster og belyser fra forskellige vinkler, hvordan portfolio kan bruges som evalueringsmetode i erhvervsuddannelserne. Udgiver: Undervisningsministeriet Udgivelsessted: Pub.uvm.dk...

  3. Leptokurtic portfolio theory

    Science.gov (United States)

    Kitt, R.; Kalda, J.

    2006-03-01

    The question of optimal portfolio is addressed. The conventional Markowitz portfolio optimisation is discussed and the shortcomings due to non-Gaussian security returns are outlined. A method is proposed to minimise the likelihood of extreme non-Gaussian drawdowns of the portfolio value. The theory is called Leptokurtic, because it minimises the effects from “fat tails” of returns. The leptokurtic portfolio theory provides an optimal portfolio for investors, who define their risk-aversion as unwillingness to experience sharp drawdowns in asset prices. Two types of risks in asset returns are defined: a fluctuation risk, that has Gaussian distribution, and a drawdown risk, that deals with distribution tails. These risks are quantitatively measured by defining the “noise kernel” — an ellipsoidal cloud of points in the space of asset returns. The size of the ellipse is controlled with the threshold parameter: the larger the threshold parameter, the larger return are accepted for investors as normal fluctuations. The return vectors falling into the kernel are used for calculation of fluctuation risk. Analogously, the data points falling outside the kernel are used for the calculation of drawdown risks. As a result the portfolio optimisation problem becomes three-dimensional: in addition to the return, there are two types of risks involved. Optimal portfolio for drawdown-averse investors is the portfolio minimising variance outside the noise kernel. The theory has been tested with MSCI North America, Europe and Pacific total return stock indices.

  4. An Electronic Patch for wearable health monitoring by reflectance pulse oximetry.

    Science.gov (United States)

    Haahr, Rasmus G; Duun, Sune B; Toft, Mette H; Belhage, Bo; Larsen, Jan; Birkelund, Karen; Thomsen, Erik V

    2012-02-01

    We report the development of an Electronic Patch for wearable health monitoring. The Electronic Patch is a new health monitoring system incorporating biomedical sensors, microelectronics, radio frequency (RF) communication, and a battery embedded in a 3-dimensional hydrocolloid polymer. In this paper the Electronic Patch is demonstrated with a new optical biomedical sensor for reflectance pulse oximetry so that the Electronic Patch in this case can measure the pulse and the oxygen saturation. The reflectance pulse oximetry solution is based on a recently developed annular backside silicon photodiode to enable low power consumption by the light emitting components. The Electronic Patch has a disposable part of soft adhesive hydrocolloid polymer and a reusable part of hard polylaurinlactam. The disposable part contains the battery. The reusable part contains the reflectance pulse oximetry sensor and microelectronics. The reusable part is 'clicked' into the disposable part when the patch is prepared for use. The patch has a size of 88 mm by 60 mm and a thickness of 5 mm.

  5. Secondary electron/reflected particle coincidence studies during slow highly charged ion-surface interactions

    Energy Technology Data Exchange (ETDEWEB)

    McGrath, C.T.; Szilagyi, Z.; Shah, M.B.; McCullough, R.W. [Queen' s Univ., Belfast, Northern Ireland (United Kingdom); Woolsey, J.M. [Stirling Univ. (United Kingdom). DBMS; Trassl, R.; Salzborn, E. [Giessen Univ. (Germany). Inst. fuer Kernphysik

    2001-07-01

    We have measured the secondary electron emission statistics (ES) for 5 keV N{sup q+} (q = 1-4) ions incident at 10 on polycrystalline aluminium, in coincidence with specularly reflected N{sup 0}. In this arrangement the kinetic contribution to secondary electron emission is minimised. The experimental data shows that the coincident electron yield, {gamma}, increases linearly with incident ion charge state. The kinetic emission contribution has also been determined from this data. The ES due to 2 and 4 keV He{sup 2+} impact on polycrystalline aluminium in coincidence with specularly reflected He{sup +} and He{sup 0} have also been determined. The process He{sup 2+} {yields} He{sup 0} yields a larger {gamma} value than the process He{sup 2+} {yields} He{sup +}. (orig.)

  6. Students' attitudes towards the introduction of a Personal and Professional Development portfolio: potential barriers and facilitators.

    Science.gov (United States)

    Ross, Sarah; Maclachlan, Alison; Cleland, Jennifer

    2009-12-01

    Portfolios, widely used in undergraduate and postgraduate medicine, have variable purposes, formats and success. A recent systematic review summarised factors necessary for successful portfolio introduction but there are no studies investigating the views of students inexperienced in portfolio use towards portfolio learning. This study's aim was to survey student views about a prospective Professional and Personal Development (PPD) portfolio. This was a qualitative, focus group study. All focus groups were taped and transcribed verbatim, and anonymised. The transcripts were analysed inductively, using framework analysis. Four focus groups were carried out with 32 undergraduate medical students naïve in portfolio use. Three themes relevant to portfolio introduction emerged. The first theme was the need for clear information and support for portfolio introduction, and anxieties about how this could be supported effectively. The second was that students had negative views about reflective learning and whether this could be taught and assessed, believing formal assessment could foster socially acceptable content. The third was that participants revealed little understanding of reflective learning and its potential benefits. Rather portfolios were seen as useful for concrete purposes (e.g., job applications) not intrinsic benefits. Undergraduate medical students without experience of portfolios are anxious about portfolio introduction. They require support in developing reflective learning skills. Care must be taken to ensure students do not see portfolios as merely yet another assessment hurdle.

  7. Reflective small angle electron scattering to characterize nanostructures on opaque substrates

    Science.gov (United States)

    Friedman, Lawrence H.; Wu, Wen-Li; Fu, Wei-En; Chien, Yunsan

    2017-09-01

    Feature sizes in integrated circuits (ICs) are often at the scale of 10 nm and are ever shrinking. ICs appearing in today's computers and hand held devices are perhaps the most prominent examples. These smaller feature sizes demand equivalent advances in fast and accurate dimensional metrology for both development and manufacturing. Techniques in use and continuing to be developed include X-ray based techniques, optical scattering, and of course the electron and scanning probe microscopy techniques. Each of these techniques has their advantages and limitations. Here, the use of small angle electron beam scattering measurements in a reflection mode (RSAES) to characterize the dimensions and the shape of nanostructures on flat and opaque substrates is demonstrated using both experimental and theoretical evidence. In RSAES, focused electrons are scattered at angles smaller than 1 ° with the assistance of electron optics typically used in transmission electron microscopy. A proof-of-concept experiment is combined with rigorous electron reflection simulations to demonstrate the efficiency and accuracy of RSAES as a method of non-destructive measurement of shapes of features less than 10 nm in size on flat and opaque substrates.

  8. Introducing E-Portfolio Use to Primary School Pupils: Response, Benefits and Challenges

    Science.gov (United States)

    Theodosiadou, Dimitra; Konstantinidis, Angelos

    2015-01-01

    Electronic portfolios (e-portfolios) have a positive impact on the learning process in a broad range of educational sectors and on learners of all ages. Yet because most e-portfolio-related studies are about their implementation in higher education, this type of research is less usual in the early childhood context, and there is no available…

  9. Improving workplace-based assessment and feedback by an E-portfolio enhanced with learning analytics

    NARCIS (Netherlands)

    van der Schaaf, Marieke; Donkers, Jeroen; Slof, Bert; Moonen-van Loon, Joyce; van Tartwijk, Jan; Driessen, Eric; Badii, Atta; Serban, Ovidiu; Ten Cate, Olle

    Electronic portfolios (E-portfolios) are crucial means for workplace-based assessment and feedback. Although E-portfolios provide a useful approach to view each learner’s progress, so far options for personalized feedback and potential data about a learner’s performances at the workplace often

  10. Improving Workplace-Based Assessment and Feedback by an E-Portfolio Enhanced with Learning Analytics

    Science.gov (United States)

    van der Schaaf, Marieke; Donkers, Jeroen; Slof, Bert; Moonen-van Loon, Joyce; van Tartwijk, Jan; Driessen, Eric; Badii, Atta; Serban, Ovidiu; Ten Cate, Olle

    2017-01-01

    Electronic portfolios (E-portfolios) are crucial means for workplace-based assessment and feedback. Although E-portfolios provide a useful approach to view each learner's progress, so far options for personalized feedback and potential data about a learner's performances at the workplace often remain unexploited. This paper advocates that…

  11. The Development of an ePortfolio as a Capstone in a Holistic Health Minor

    Science.gov (United States)

    Perks, Joan M.; Galantino, Mary Lou

    2013-01-01

    Use of electronic portfolios (ePortfolios) has been advocated to highlight student accomplishments as well as to document program and course outcomes. This use of ePortfolios incorporates information technology, thus aligning the educational process in degree programs to twenty-first-century teaching, learning, and information literacy. Here we…

  12. Reflection of electromagnetic radiation from plasma with an anisotropic electron velocity distribution

    International Nuclear Information System (INIS)

    Vagin, K. Yu.; Uryupin, S. A.

    2013-01-01

    The reflection of a test electromagnetic pulse from the plasma formed as a result of tunnel ionization of atoms in the field of a circularly polarized high-power radiation pulse is analyzed using the kinetic approach to describe electron motion. It is shown that the reflected pulse is significantly amplified due to the development of Weibel instability. The amplification efficiency is determined by the maximum value of the instability growth rate, which depends on the degree of anisotropy of the photoelectron distribution function

  13. Twelve tips for creating an academic teaching portfolio.

    Science.gov (United States)

    Little-Wienert, Kim; Mazziotti, Mark

    2018-01-01

    An academic teaching portfolio is not only a requirement at many academic teaching institutions, but it is also important in a medical educator's growth and development through documentation, reflection, evaluation, and change. Creating an academic portfolio may appear daunting at first but with careful advanced preparation, organized evidence collection of your educational work, proof of scholarship, and thorough documentation of self-reflection and change, you can produce a successful product that accurately represents your educational beliefs, accomplishments, and growth throughout your career. This article provides medical educators with twelve steps for creating a successful academic teaching portfolio.

  14. Magnetospheric Response Associated With Multiple Atmospheric Reflections of Precipitated Electrons in Aurora.

    Science.gov (United States)

    Khazanov, G. V.; Merkin, V. G.; Zesta, E.; Sibeck, D. G.; Grubbs, G. A., II; Chu, M.; Wiltberger, M. J.

    2017-12-01

    The magnetosphere and ionosphere are strongly coupled by precipitating electrons during storm times. Therefore, first principle simulations of precipitating electron fluxes are required to understand storm time variations of ionospheric conductances and related electric fields. As has been discussed by Khazanov et al. [2015 - 2017], the first step in such simulations is initiation of electron precipitation from the Earth's plasma sheet via wave particle interaction processes into both magnetically conjugate points, and the step 2 is the follow up of multiple atmospheric reflections of electron fluxes formed at the boundary between the ionosphere and magnetosphere of two magnetically conjugate points. To demonstrate this effect on the global magnetospheric response the Lyon-Fedder-Mobarry global magnetosphere model coupled with the Rice Convection Model of the inner magnetosphere has been used and run for the geomagnetic storm of 17 March 2013.

  15. Specular Reflectivity and Hot-Electron Generation in High-Contrast Relativistic Laser-Plasma Interactions

    Energy Technology Data Exchange (ETDEWEB)

    Kemp, Gregory Elijah [The Ohio State Univ., Columbus, OH (United States)

    2013-01-01

    Ultra-intense laser (> 1018 W/cm2) interactions with matter are capable of producing relativistic electrons which have a variety of applications in state-of-the-art scientific and medical research conducted at universities and national laboratories across the world. Control of various aspects of these hot-electron distributions is highly desired to optimize a particular outcome. Hot-electron generation in low-contrast interactions, where significant amounts of under-dense pre-plasma are present, can be plagued by highly non-linear relativistic laser-plasma instabilities and quasi-static magnetic field generation, often resulting in less than desirable and predictable electron source characteristics. High-contrast interactions offer more controlled interactions but often at the cost of overall lower coupling and increased sensitivity to initial target conditions. An experiment studying the differences in hot-electron generation between high and low-contrast pulse interactions with solid density targets was performed on the Titan laser platform at the Jupiter Laser Facility at Lawrence Livermore National Laboratory in Livermore, CA. To date, these hot-electrons generated in the laboratory are not directly observable at the source of the interaction. Instead, indirect studies are performed using state-of-the-art simulations, constrained by the various experimental measurements. These measurements, more-often-than-not, rely on secondary processes generated by the transport of these electrons through the solid density materials which can susceptible to a variety instabilities and target material/geometry effects. Although often neglected in these types of studies, the specularly reflected light can provide invaluable insight as it is directly influenced by the interaction. In this thesis, I address the use of (personally obtained) experimental specular reflectivity measurements to indirectly study hot-electron generation in the context of high-contrast, relativistic

  16. Utility portfolio diversification

    International Nuclear Information System (INIS)

    Griffes, P.H.

    1990-01-01

    This paper discusses portfolio analysis as a method to evaluate utility supply decisions. Specifically a utility is assumed to increase the value of its portfolio of assets whenever it invests in a new supply technology. This increase in value occurs because the new asset either enhances the return or diversifies the risks of the firm's portfolio of assets. This evaluation method is applied to two supply innovations in the electric utility industry: jointly-owned generating plants and supply contracts with independent power producers (IPPs)

  17. Constant Proportion Portfolio Insurance

    DEFF Research Database (Denmark)

    Jessen, Cathrine

    2014-01-01

    on the theme, originally proposed by Fischer Black. In CPPI, a financial institution guarantees a floor value for the “insured” portfolio and adjusts the stock/bond mix to produce a leveraged exposure to the risky assets, which depends on how far the portfolio value is above the floor. Plain-vanilla portfolio...... insurance largely died with the crash of 1987, but CPPI is still going strong. In the frictionless markets of finance theory, the issuer’s strategy to hedge its liability under the contract is clear, but in the real world with transactions costs and stochastic jump risk, the optimal strategy is less obvious...

  18. Lunar surface remanent magnetic fields detected by the electron reflection method

    Science.gov (United States)

    Lin, R. P.; Anderson, K. A.; Bush, R.; Mcguire, R. E.; Mccoy, J. E.

    1976-01-01

    We present maps of the lunar surface remanent magnetic fields detected by the electron reflection method. These maps provide substantial coverage of the latitude band from 30 N southward to 30 S with a resolution of about 40 km and a sensitivity of about 0.2 gamma at the lunar surface. Regions of remanent magnetization are observed ranging in size from the resolution limit of 1.25 deg to above approximately 60 deg. The largest contiguous region fills the Big Backside Basin where it is intersected by the spacecraft orbital tracks. Preliminary analyses of the maps show that the source regions of lunar limb compressions correspond to regions of strong surface magnetism, and that there does not appear to be sharply discontinuous magnetization at the edges of maria. We also analyze the electron reflection observations to obtain information on the direction and distribution of magnetization in the Van de Graaff anomaly region.

  19. Portfolio Management System

    Data.gov (United States)

    US Agency for International Development — PfMS is an implementation of WorkLenz. WorkLenz is USAID's portfolio management system tool. It is a commercially available, off-the-shelf (COTS) package that...

  20. Une analyse des représentations des enseignants réfléchissant sur une expérience d’implantation d’un portfolio électronique / An Analysis of the Perceptions of Teachers Reflecting on an Experience of e-Portfolio Implementation

    Directory of Open Access Journals (Sweden)

    Ann-Louise Davidson

    2012-08-01

    Full Text Available Cet article rend compte d’une analyse des représentations avec des enseignants, qui a eu lieu à la fin d’une expérience d’implantation d’un portfolio électronique favorisant l’autorégulation des apprentissages des élèves et la professionnalisation des enseignants. Le texte s’appuie sur le contexte éducatif québécois actuel. Ensuite, il présente une revue de littérature entourant les compétences technologiques, les portfolios électroniques et l’autorégulation des apprentissages. La méthodologie présente le design de la recherche, les instruments utilisés pour les entretiens et pour animer le groupe de discussion. Les résultats montrent que pour une enseignante qui avait déjà adopté la pédagogie sous-jacente au renouveau pédagogique Québécois, le portfolio électronique était une expérience fort utile. Toutefois, pour les deux autres enseignants, l’implantation du portfolio électronique était beaucoup trop exigeante. Finalement, nous discutons des implications des résultats, autant au point de vue de l’expérience d’implantation des portfolios électroniques que du point de vue de la contribution méthodologique. This article presents an analysis of the perceptions of teachers, which took place in 2010 at the end of an experiment implementing an e-portfolio that facilitates student self-regulation of learning. The article is based on the current Quebec educational context. It presents a review of literature on technology skills, e-portfolios and the self-regulation of learning. The methodology describes the research design, the tools used in the individual interviews and in the group discussion. The results indicate that the e-portfolio was a valuable experience for a teacher who had already adopted the pedagogy underlying the education reform in Quebec. However the implementation of the e-portfolio was difficult for the other two teachers due to challenges in terms of technology and managing

  1. Designing Modern Equity Portfolios

    OpenAIRE

    Ronald Jean Degen

    2011-01-01

    This aim of this paper is to describe possible ways of investing in equity; choosing the right stocks(among small-cap, large-cap, value, growth, and foreign) using fundamental analysis, defining their appropriate mix in the portfolios according to the desired return-risk profiles based on Markowitz?s modern portfolio theory, and using technical analysis to buy and sell them.

  2. Learning Styles and e-portfolio in Nursing Education

    DEFF Research Database (Denmark)

    Nielsen, Kirsten; Pedersen, Birthe D.; Helms, Niels Henrik

    Purpose of the study Research from UK and USA indicates that an e-portfolio facilitates a stronger connection between theoretical and clinical studies in Nursing Education. It helps students reflect over practice and their own skills. Yet other results show that an e-portfolio is a time consumer....... Thus, the aim of this project is to examine the effects of an e-portfolio on nursing students learning of patients with chronic illness during their clinical practice, and to investigate if it makes any difference in facilitating four learning styles: the activist, the reflector, the theorist...... through observations in clinical settings, narrative interviews, and print-outs from the students e-portfolio. Findings So far a pilot project with a questionnaire shows that 84% of the students and nurses reported that the e-portfolio has a positive effect on students learning in clinical settings...

  3. Electronic spreadsheet to acquire the reflectance from the TM and ETM+ Landsat images

    Directory of Open Access Journals (Sweden)

    Antonio R. Formaggio

    2005-08-01

    Full Text Available The reflectance of agricultural cultures and other terrestrial surface "targets" is an intrinsic parameter of these targets, so in many situations, it must be used instead of the values of "gray levels" that is found in the satellite images. In order to get reflectance values, it is necessary to eliminate the atmospheric interference and to make a set of calculations that uses sensor parameters and information regarding the original image. The automation of this procedure has the advantage to speed up the process and to reduce the possibility of errors during calculations. The objective of this paper is to present an electronic spreadsheet that simplifies and automatizes the transformation of the digital numbers of the TM/Landsat-5 and ETM+/Landsat-7 images into reflectance. The method employed for atmospheric correction was the dark object subtraction (DOS. The electronic spreadsheet described here is freely available to users and can be downloaded at the following website: http://www.dsr.inpe.br/Calculo_Reflectancia.xls.

  4. Measurement of the band gap by reflection electron energy loss spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Vos, Maarten, E-mail: maarten.vos@anu.edu.au [Electronic Materials Engineering Department, Research School of Physics and Engineering, The Australian National University, Canberra 0200 (Australia); King, Sean W. [Logic Technology Development, Intel Corporation, Hillsboro, OR 97124 (United States); French, Benjamin L. [Ocotillo Materials Laboratory, Intel Corporation, Chandler, AZ 85248 (United States)

    2016-10-15

    Highlights: • Semiconductors are measured (without surface preparation) using REELS. • At low beam energies it is difficult to measure band gap due to surface impurities. • At very high energies it is difficult to measure band gap due to recoil effect. • At intermediate energies (around 5 keV) one obtains a good estimate of the band gap. - Abstract: We investigate the possibilities of measuring the band gap of a variety of semiconductors and insulators by reflection electron energy loss spectroscopy without additional surface preparation. The band gap is a bulk property, whereas reflection energy loss spectroscopy is generally considered a surface sensitive technique. By changing the energy of the incoming electrons, the degree of surface sensitivity can be varied. Here, we present case studies to determine the optimum condition for the determination of the band gap. At very large incoming electron energies recoil effects interfere with the band gap determination, whereas at very low energies surface effects are obscuring the band gap without surface preparation. Using an incoming energy of 5 keV a reasonable estimate of the band gap is obtained in most cases.

  5. Measurement of the band gap by reflection electron energy loss spectroscopy

    International Nuclear Information System (INIS)

    Vos, Maarten; King, Sean W.; French, Benjamin L.

    2016-01-01

    Highlights: • Semiconductors are measured (without surface preparation) using REELS. • At low beam energies it is difficult to measure band gap due to surface impurities. • At very high energies it is difficult to measure band gap due to recoil effect. • At intermediate energies (around 5 keV) one obtains a good estimate of the band gap. - Abstract: We investigate the possibilities of measuring the band gap of a variety of semiconductors and insulators by reflection electron energy loss spectroscopy without additional surface preparation. The band gap is a bulk property, whereas reflection energy loss spectroscopy is generally considered a surface sensitive technique. By changing the energy of the incoming electrons, the degree of surface sensitivity can be varied. Here, we present case studies to determine the optimum condition for the determination of the band gap. At very large incoming electron energies recoil effects interfere with the band gap determination, whereas at very low energies surface effects are obscuring the band gap without surface preparation. Using an incoming energy of 5 keV a reasonable estimate of the band gap is obtained in most cases.

  6. Portfólios reflexivos: construindo competências para o trabalho no Sistema Único de Saúde Learning portfolios as a tool for reflection: building competencies for work in the Unified Health System

    Directory of Open Access Journals (Sweden)

    Rosângela Minardi Mitre Cotta

    2011-11-01

    Full Text Available OBJETIVO: Avaliar a experiência inovadora de educação por competências através de portfólios para a formação de profissionais que atuarão no Sistema Único de Saúde (SUS no Brasil. MÉTODOS: Utilizou-se a pesquisa qualitativa como modelo de abordagem. Realizou-se a análise documental de 25 portfólios produzidos nos anos de 2008, 2009 e 2010 na disciplina de Políticas de Saúde na Universidade Federal de Viçosa, Minas Gerais, Brasil, com o objetivo de verificar se esse método permitiu a aquisição das competências de aprender a ser (atuar com autonomia, juízo, responsabilidade pessoal; aprender a conhecer (assimilar conhecimentos científicos e culturais gerais e específicos, que se completarão e atualizarão ao longo da vida; aprender a fazer (adquirir procedimentos que ajudem a enfrentar dificuldades na vida e na profissão; e aprender a conviver e a trabalhar com outros (compreender melhor os demais, o mundo e suas inter-relações. RESULTADOS: Observou-se um envolvimento com as atividades propostas, destacando-se a gestão da informação (busca ativa, seleção, análises críticas, resenhas, sínteses e avaliação da informação. Houve uma gradativa abertura ao pensamento crítico, integrando novas dimensões à visão inicial dos estudantes sobre o SUS, que passou do foco na doença e na cura para um foco em saúde e prevenção, e de uma visão do SUS como modelo teórico para a visão de um projeto possível e em construção. CONCLUSÕES: O uso dos portfólios possibilitou a formação de profissionais de saúde-cidadãos, com ênfase acadêmica, pedagógica e prática. Isso indica que a universidade e o docente podem orientar-se ao desenvolvimento da capacidade de decisão e pensamento reflexivo dos estudantesOBJECTIVE: To assess the innovative experience of competency education through reflective portfolios for the training of professionals who will work in the Brazilian Unified Health System (SUS. METHODS: A

  7. ePortfolio & learning styles in Nursing Education

    DEFF Research Database (Denmark)

    Nielsen, Kirsten; Helms, Niels Henrik; Pedersen, Birthe D.

    2012-01-01

    Background Examination of the literature shows both advantages and disadvantages in implementing ePortfolio and learning styles in Nursing Education. The students reflect on nursing practice as well as on their strengths and weaknesses, and reflecting in the portfolio increases self-awareness, pe......Background Examination of the literature shows both advantages and disadvantages in implementing ePortfolio and learning styles in Nursing Education. The students reflect on nursing practice as well as on their strengths and weaknesses, and reflecting in the portfolio increases self...... in clinical settings. Insight into preferred learning style can be an advantage to both students and preceptors in attempt to promote students´ learning potential, but there are quite many different theoretical approaches and definitions of the concept, and reviewers call attention to the risk that teachers...... to intensify the differentiated guidance of students, and developed an ePortfolio which aim to facilitate four learning styles as described by Honey and Mumford. It was tested in a pilot project and now, a qualitative study of how learning is mediated in clinical education through this ePortfolio is passing...

  8. E-Portfolios Rescue Biology Students from a Poorer Final Exam Result: Promoting Student Metacognition

    Science.gov (United States)

    Haave, Neil

    2016-01-01

    E-portfolios have the potential to transform students' learning experiences. They promote reflection on the significance of what and how students have learned. Such reflective practices enhance students' ability to articulate their knowledge and skills to their peers, teachers, and future employers. In addition, e-portfolios can help assess the…

  9. Narratives of Learning: The Personal Portfolio in the Portfolio Approach to Teaching and Learning

    Science.gov (United States)

    Leslie, Paul; Camargo-Borges, Celiane

    2017-01-01

    This paper will explore how a portfolio approach to teaching and learning can help the educator incorporate unique forms of reflective practice into his or her daily work. By being able to express ideas more clearly to himself, the educator can better promote the relational construction of knowledge in his educational communities. This paper, as…

  10. AN EXAMPLE FOR PORTFOLIO PREPARATION IN GERMAN TEACHER TRAINING

    Directory of Open Access Journals (Sweden)

    Hüseyin ARAK

    2017-04-01

    Full Text Available In this study we are trying with the help of portfolio in teacher training and the diagnosis of the learning group concerning their skills in translation from German to Turkish, to show the documentation of the learning process. The portfolio provides a good overview about the performance of the students and it also prepares a basis for assessment. A growing self-awareness of students can be achieved through implementing the portfolio-method. The students should collect and reflect the most important materials and practices leading to key terms of the seminar. It is more than an assessment method it is a surrounding of learning. The work with portfolio has an influence on teaching, learning and assessing. As in detail, this is dependent on the aims and other characteristics of the models which take the portfolio work as a basis. The portfolio provides us a big advantage for the support of the cultural reflection. We can observe the process of the growth of knowledge step by step, because the measurement of the development in a determined period allows us either a written work or a Multiple Choice Test. In this sense we can look at the portfolio as an assessment instrument of a process.

  11. Backtesting Portfolio Value-at-Risk with Estimated Portfolio Weights

    OpenAIRE

    Pei Pei

    2010-01-01

    This paper theoretically and empirically analyzes backtesting portfolio VaR with estimation risk in an intrinsically multivariate framework. For the first time in the literature, it takes into account the estimation of portfolio weights in forecasting portfolio VaR and its impact on backtesting. It shows that the estimation risk from estimating the portfolio weights as well as that from estimating the multivariate dynamic model of asset returns make the existing methods in a univariate framew...

  12. Reflective portfolios support learning, personal growth and ...

    African Journals Online (AJOL)

    The Master's degree in Child Health (MSc) and Master's degree in Public. Health (MPH (MCH)) at ... This study involved a qualitative, retrospective record review of .... as fear of confidentiality being breached, distraction from other coursework.

  13. Reflection of femtosecond pulses from soft X-ray free-electron laser by periodical multilayers

    Energy Technology Data Exchange (ETDEWEB)

    Ksenzov, D.; Grigorian, S.; Pietsch, U. [Faculty of Physics, University of Siegen (Germany); Hendel, S.; Bienert, F.; Sacher, M.D.; Heinzmann, U. [Faculty of Physics, University of Bielefeld (Germany)

    2009-08-15

    Recent experiments on a soft X-ray free-electron laser (FEL) source (FLASH in Hamburg) have shown that multilayers (MLs) can be used as optical elements for highly intense X-ray irradiation. An effort to find most appropriate MLs has to consider the femtosecond time structure and the particular photon energy of the FEL. In this paper we have analysed the time response of 'low absorbing' MLs (e.g. such as La/B{sub 4}C) as a function of the number of periods. Interaction of a pulse train of Gaussian shaped sub-pulses using a realistic ML grown by electron-beam evaporation technique has been analysed in the soft-X-ray range. The structural parameters of the MLs were obtained by reflectivity measurements at BESSY II and subsequent profile fittings. (Abstract Copyright [2009], Wiley Periodicals, Inc.)

  14. Interaction of magnetized electrons with a boundary sheath: investigation of a specular reflection model

    Science.gov (United States)

    Krüger, Dennis; Brinkmann, Ralf Peter

    2017-11-01

    This publication reports analytical and numerical results concerning the interaction of gyrating electrons with a plasma boundary sheath, with focus on partially magnetized technological plasmas. It is assumed that the electron Debye length {λ }{{D}} is much smaller than the electron gyroradius {r}{{L}}, and {r}{{L}} in turn much smaller than the mean free path λ and the gradient length L of the fields. Focusing on the scale of the gyroradius, the sheath is assumed as infinitesimally thin ({λ }{{D}}\\to 0), collisions are neglected (λ \\to ∞ ), the magnetic field is taken as homogeneous, and electric fields (=potential gradients) in the bulk are neglected (L\\to ∞ ). The interaction of an electron with the electric field of the plasma boundary sheath is represented by a specular reflection {v}\\to {v}-2{v}\\cdot {{e}}z {{e}}z of the velocity {v} at the plane z = 0 of a naturally oriented Cartesian coordinate system (x,y,z). The electron trajectory is then given as sequences of helical sections, with the kinetic energy ɛ and the canonical momenta p x and p y conserved, but not the position of the axis (base point {{R}}0), the slope (pitch angle χ), and the phase (gyrophase φ). A ‘virtual interaction’ which directly maps the incoming electrons to the outgoing ones is introduced and studied in dependence of the angle γ between the field and the sheath normal {{e}}z. The corresponding scattering operator is constructed, mathematically characterized, and given as an infinite matrix. An equivalent boundary condition for a transformed kinetic model is derived.

  15. Decentralized Portfolio Management

    Directory of Open Access Journals (Sweden)

    Benjamin Miranda Tabak

    2003-12-01

    Full Text Available We use a mean-variance model to analyze the problem of decentralized portfolio management. We find the solution for the optimal portfolio allocation for a head trader operating in n different markets, which is called the optimal centralized portfolio. However, as there are many traders specialized in different markets, the solution to the problem of optimal decentralized allocation should be different from the centralized case. In this paper we derive conditions for the solutions to be equivalent. We use multivariate normal returns and a negative exponential function to solve the problem analytically. We generate the equivalence of solutions by assuming that different traders face different interest rates for borrowing and lending. This interest rate is dependent on the ratio of the degrees of risk aversion of the trader and the head trader, on the excess return, and on the correlation between asset returns.

  16. Probing Ultrafast Electron Dynamics at Surfaces Using Soft X-Ray Transient Reflectivity Spectroscopy

    Science.gov (United States)

    Baker, L. Robert; Husek, Jakub; Biswas, Somnath; Cirri, Anthony

    The ability to probe electron dynamics with surface sensitivity on the ultrafast time scale is critical for understanding processes such as charge separation, injection, and surface trapping that mediate efficiency in catalytic and energy conversion materials. Toward this goal, we have developed a high harmonic generation (HHG) light source for femtosecond soft x-ray reflectivity. Using this light source we investigated the ultrafast carrier dynamics at the surface of single crystalline α-Fe2O3, polycrystalline α-Fe2O3, and the mixed metal oxide, CuFeO2. We have recently demonstrated that CuFeO2 in particular is a selective catalyst for photo-electrochemical CO2 reduction to acetate; however, the role of electronic structure and charge carrier dynamics in mediating catalytic selectivity has not been well understood. Soft x-ray reflectivity measurements probe the M2,3, edges of the 3d transition metals, which provide oxidation and spin state resolution with element specificity. In addition to chemical state specificity, these measurements are also surface sensitive, and by independently simulating the contributions of the real and imaginary components of the complex refractive index, we can differentiate between surface and sub-surface contributions to the excited state spectrum. Accordingly, this work demonstrates the ability to probe ultrafast carrier dynamics in catalytic materials with element and chemical state specificity and with surface sensitivity.

  17. Linearly Adjustable International Portfolios

    Science.gov (United States)

    Fonseca, R. J.; Kuhn, D.; Rustem, B.

    2010-09-01

    We present an approach to multi-stage international portfolio optimization based on the imposition of a linear structure on the recourse decisions. Multiperiod decision problems are traditionally formulated as stochastic programs. Scenario tree based solutions however can become intractable as the number of stages increases. By restricting the space of decision policies to linear rules, we obtain a conservative tractable approximation to the original problem. Local asset prices and foreign exchange rates are modelled separately, which allows for a direct measure of their impact on the final portfolio value.

  18. Linearly Adjustable International Portfolios

    International Nuclear Information System (INIS)

    Fonseca, R. J.; Kuhn, D.; Rustem, B.

    2010-01-01

    We present an approach to multi-stage international portfolio optimization based on the imposition of a linear structure on the recourse decisions. Multiperiod decision problems are traditionally formulated as stochastic programs. Scenario tree based solutions however can become intractable as the number of stages increases. By restricting the space of decision policies to linear rules, we obtain a conservative tractable approximation to the original problem. Local asset prices and foreign exchange rates are modelled separately, which allows for a direct measure of their impact on the final portfolio value.

  19. Agile Project Portfolio Management

    DEFF Research Database (Denmark)

    Andersen, Jesper Rank; Riis, Jens Ove; Mikkelsen, Hans

    2005-01-01

    This paper will provide a preliminary introduction to the application of Agile Thinking in management of project portfolio and company development. At any point in time, companies have a crowd of development initiatives spread around the organisation and managed at different levels...... in the managerial hierarchy. They compete for resources and managerial attention, and they often take too long time - and some do not survive in the rapid changing context. Top man¬agers ask for speed, flexibility and effectiveness in the portfolio of development activities (projects). But which competencies...

  20. Portfolio Analysis for Vector Calculus

    Science.gov (United States)

    Kaplan, Samuel R.

    2015-01-01

    Classic stock portfolio analysis provides an applied context for Lagrange multipliers that undergraduate students appreciate. Although modern methods of portfolio analysis are beyond the scope of vector calculus, classic methods reinforce the utility of this material. This paper discusses how to introduce classic stock portfolio analysis in a…

  1. Coulomb Blockade and Multiple Andreev Reflection in a Superconducting Single-Electron Transistor

    Science.gov (United States)

    Lorenz, Thomas; Sprenger, Susanne; Scheer, Elke

    2018-06-01

    In superconducting quantum point contacts, multiple Andreev reflection (MAR), which describes the coherent transport of m quasiparticles each carrying an electron charge with m≥3, sets in at voltage thresholds eV = 2Δ /m. In single-electron transistors, Coulomb blockade, however, suppresses the current at low voltage. The required voltage for charge transport increases with the square of the effective charge eV∝ ( me) ^2. Thus, studying the charge transport in all-superconducting single-electron transistors (SSETs) sets these two phenomena into competition. In this article, we present the fabrication as well as a measurement scheme and transport data for a SSET with one junction in which the transmission and thereby the MAR contributions can be continuously tuned. All regimes from weak to strong coupling are addressed. We extend the Orthodox theory by incorporating MAR processes to describe the observed data qualitatively. We detect a new transport process the nature of which is unclear at present. Furthermore, we observe a renormalization of the charging energy when approaching the strong coupling regime.

  2. Surface energy loss processes in XPS studied by absolute reflection electron energy loss spectroscopy

    International Nuclear Information System (INIS)

    Nagatomi, T.; Goto, K.

    2010-01-01

    The results of the investigation of the inelastic interaction of 300-3000 eV electrons with the Ni and Au surfaces by the analysis of absolute reflection electron energy loss spectroscopy (REELS) spectra were described. The present analysis enables the inelastic mean free path (IMFP), surface excitation parameter (SEP) and differential SEP (DSEP) to be obtained simultaneously from an absolute REELS spectrum. The obtained IMFPs for Ni and Au showed a good agreement with those calculated using the TPP-2M predictive equation. The present SEPs determined for Ni and Au were fitted to the Chen's formula describing the dependence of the SEP on the electron energy, and material parameters for Ni and Au in Chen's formula were proposed. The present DESPs were compared with the theoretical results, and a reasonable agreement between the experimentally determined DSEPs and theoretical results was confirmed. The MC modeling of calculating the REELS spectrum, in which energy loss processes due to surface excitations are taken into account, was also described. The IMFP, SEP and DSEP determined by the present absolute REELS analysis were employed to describe energy loss processes by inelastic scattering in the proposed MC simulation. The simulated REELS spectra were found to be in a good agreement with the experimental spectra for both Ni and Au.

  3. Evaluation of IP Portfolios

    DEFF Research Database (Denmark)

    Søberg, Peder Veng

    2009-01-01

    As a result of an inquiry concerning how to evaluate IP (intellectual property) portfolios in order to enable the best possible use of IP resources within organizations, an IP evaluation approach primarily applicable for patents and utility models is developed. The developed approach is useful...... of the organization owning the IP....

  4. Acreage portfolio management

    International Nuclear Information System (INIS)

    Schneider, Georges

    1994-01-01

    This chapter demonstrates the need for acreage portfolio management at the stage of maturity which has been reached in the UK sector of the North Sea petroleum industry. It outlines the goals, the main features of the deals and the business process. (UK)

  5. Portfolio, refleksion og feedback

    DEFF Research Database (Denmark)

    Hansen, Jens Jørgen; Qvortrup, Ane; Christensen, Inger-Marie F.

    2017-01-01

    Denne leder definerer indledningsvist begrebet portfolio og gør rede for anvendelsesmuligheder i en uddannelseskontekst. Dernæst behandles portfoliometodens kvalitet og effekt for læring og undervisning og de centrale begreber refleksion, progression og feedback præsenteres og diskuteres. Herefter...

  6. Sparse and stable Markowitz portfolios.

    Science.gov (United States)

    Brodie, Joshua; Daubechies, Ingrid; De Mol, Christine; Giannone, Domenico; Loris, Ignace

    2009-07-28

    We consider the problem of portfolio selection within the classical Markowitz mean-variance framework, reformulated as a constrained least-squares regression problem. We propose to add to the objective function a penalty proportional to the sum of the absolute values of the portfolio weights. This penalty regularizes (stabilizes) the optimization problem, encourages sparse portfolios (i.e., portfolios with only few active positions), and allows accounting for transaction costs. Our approach recovers as special cases the no-short-positions portfolios, but does allow for short positions in limited number. We implement this methodology on two benchmark data sets constructed by Fama and French. Using only a modest amount of training data, we construct portfolios whose out-of-sample performance, as measured by Sharpe ratio, is consistently and significantly better than that of the naïve evenly weighted portfolio.

  7. Portfolio optimization retail investor

    Directory of Open Access Journals (Sweden)

    I. А. Kiseleva

    2016-01-01

    Full Text Available The article notes that the task of the investor's risk management is to, on the one hand, as much as possible to strive to achieve the criterion of risk level, and on the other hand, in any case not exceed it. Since the domestic theory of risk management is under development, the problem of the optimal ratio of "risk-income" becomes now of particular relevance. This article discusses the different distribution areas of the private investor in order to obtain the maximum profit. The analysis showed us the overall economic and political system of the country, as well as the legislative provision of guarantees to the investor. To obtain sufficient income and reduce losses it is important to maintain the optimum value found between the amount of the investor's risk and capital transactions. Model of optimal placement of funds led to the conclusion about inexpediency strong increase in the diversification of the investment portfolio (more than 10 different types of assets in the portfolio, since it increases the complexity of its practical form, while the portfolio characteristics are improved significantly. It is concluded that it is impossible to increase revenue without increasing the risk or reduce risk without reducing income. The analysis shows that there is no single best asset portfolio. It is impossible to increase revenue without increasing the risk or reduce risk without reducing income. Possible combination of the "riskincome" will depend on the objective function. Most diversified and bringing the best return per unit of risk, is a portfolio that contains the most risky assets.

  8. Imaging spin filter for electrons based on specular reflection from iridium (001)

    Energy Technology Data Exchange (ETDEWEB)

    Kutnyakhov, D.; Lushchyk, P. [Johannes Gutenberg-Universität, Institut für Physik, 55099 Mainz (Germany); Fognini, A.; Perriard, D. [Laboratorium für Festkörperphysik, ETH Zürich, 8093 Zürich (Switzerland); Kolbe, M.; Medjanik, K.; Fedchenko, E.; Nepijko, S.A.; Elmers, H.J. [Johannes Gutenberg-Universität, Institut für Physik, 55099 Mainz (Germany); Salvatella, G.; Stieger, C.; Gort, R.; Bähler, T.; Michlmayer, T.; Acremann, Y.; Vaterlaus, A. [Laboratorium für Festkörperphysik, ETH Zürich, 8093 Zürich (Switzerland); Giebels, F.; Gollisch, H.; Feder, R. [Universität Duisburg-Essen, Theoretische Festkörperphysik, 47057 Duisburg (Germany); Tusche, C. [Max Planck-Institut für Mikrostrukturphysik, 06120 Halle (Germany); and others

    2013-07-15

    As Stern–Gerlach type spin filters do not work with electrons, spin analysis of electron beams is accomplished by spin-dependent scattering processes based on spin–orbit or exchange interaction. Existing polarimeters are single-channel devices characterized by an inherently low figure of merit (FoM) of typically 10{sup −4}–10{sup −3}. This single-channel approach is not compatible with parallel imaging microscopes and also not with modern electron spectrometers that acquire a certain energy and angular interval simultaneously. We present a novel type of polarimeter that can transport a full image by making use of k-parallel conservation in low-energy electron diffraction. We studied specular reflection from Ir (001) because this spin-filter crystal provides a high analyzing power combined with a “lifetime” in UHV of a full day. One good working point is centered at 39 eV scattering energy with a broad maximum of 5 eV usable width. A second one at about 10 eV shows a narrower profile but much higher FoM. A relativistic layer-KKR SPLEED calculation shows good agreement with measurements. - Highlights: • Novel type of spin polarimeter can transport a full image by making use of k{sup →}{sub ||} conservation in LEED. • When combined with a hemispherical analyzer, it acquires a certain energy and angular interval simultaneously. • Ir (001) based spin-filter provides a high analyzing power combined with a “lifetime” in UHV of a full day. • Parallel spin detection improves spin polarimeter efficiency by orders of magnitude. • A relativistic layer-KKR SPLEED calculation shows good agreement with measurements.

  9. Scanning tunnel microscopic image of tungsten (100) and (110) real surfaces and nature of conduction electron reflection

    International Nuclear Information System (INIS)

    Pryadkin, S.L.; Tsoj, V.S.

    1988-01-01

    The electrically polished (100) and (110) surfaces of tungsten are studied with the aid of a scanning tunnel microscope at atmospheric pressure. The (110) surface consists of a large number of atomically plane terraces whereas the (100) surface is faceted. The scanning tunnel microscope data can explain such results of experiments on transverse electron focussing as the strong dependence of the probability for specular reflection of conduction electrons scattered by the (100) surface on the electron de Broglie wavelength and the absence of a dependence of the probability for specular reflection on the wavelength for the (110) surface

  10. Strategic innovation portfolio management

    Directory of Open Access Journals (Sweden)

    Stanković Ljiljana

    2015-01-01

    Full Text Available In knowledge-based economy, strategic innovation portfolio management becomes more and more important and critical factor of enterprise's success. Value creation for all the participants in value chain is more successful if it is based on efficient resource allocation and improvement of innovation performances. Numerous researches have shown that companies with best position on the market found their competitiveness on efficient development and exploitation of innovations. In decision making process, enterprise's management is constantly faced with challenge to allocate resources and capabilities as efficiently as possible, in both short and long term. In this paper authors present preliminary results of realized empirical research related to strategic innovation portfolio management in ten chosen enterprises in Serbia. The structure of the paper includes the following parts: theoretical background, explanation of research purpose and methodology, discussion of the results and concluding remarks, including limitations and directions for further research.

  11. Acreage portfolio management

    International Nuclear Information System (INIS)

    Schneider, G.M.

    1992-01-01

    This paper reports that the need for managing the acreage portfolio in the UK North Sea arises from fragmentation of holdings and complex field partnerships. The main concepts are building up the heartlands and balancing cashflow forecasts. This has generated a number of friendly win-win deals, motivated by differences in perception of values. The business process includes identifying, evaluating and negotiating deals. The Petroleum Economist plays a central role throughout this process, seeking value gaps and supporting negotiations. Variations in reserves estimates present a major source of value gaps between buyer and seller. Economists need to work closely with engineers and geologists. Portfolio management is an exciting and challenging task which broadens the traditional role of the Petroleum Economist

  12. On portfolio risk diversification

    Science.gov (United States)

    Takada, Hellinton H.; Stern, Julio M.

    2017-06-01

    The first portfolio risk diversification strategy was put into practice by the All Weather fund in 1996. The idea of risk diversification is related to the risk contribution of each available asset class or investment factor to the total portfolio risk. The maximum diversification or the risk parity allocation is achieved when the set of risk contributions is given by a uniform distribution. Meucci (2009) introduced the maximization of the Rényi entropy as part of a leverage constrained optimization problem to achieve such diversified risk contributions when dealing with uncorrelated investment factors. A generalization of the risk parity is the risk budgeting when there is a prior for the distribution of the risk contributions. Our contribution is the generalization of the existent optimization frameworks to be able to solve the risk budgeting problem. In addition, our framework does not possess any leverage constraint.

  13. Hvorfor anvende portfolio eksamen?

    DEFF Research Database (Denmark)

    Elley, Tina Ninka

    2015-01-01

    from the clinical part. The two topics are weighted according to the distribution of ECTS points between theory and clinic. We implemented the portfolio format in November 2012, and the evaluations from the students have shown that the format is good; the students get less stressed at the exam......In Denmark the Biomedical Laboratory Scientist programme lasts for 3½ years, divided into 14 modules of 10 weeks. Every module concludes with an exam, which can be very stressful for the students. A survey was made among the students, confirming this. How can we change some of the exams in order...... to minimize the students' stress level? Then the pedagogical considerations started – where and how to do this? The conclusion was to work with the portfolio format at module 6 and module 7 and make it the exam form, as it was possible to divide the expected learning outcome for the two modules into topics...

  14. Acreage portfolio management

    International Nuclear Information System (INIS)

    Schneider

    1992-01-01

    This paper reports that the need to manage U.K. North Sea acreage portfolios arises from fragmentation of holdings and complex partnerships. This management has generated friendly rationalization deals motivated by differences in perception of values and aimed at building up heartlands and balancing cash-flow forecasts. The business process includes identifying, evaluating, and negotiating deals. The economist plays a central role within the evaluation team and supports the negotiators

  15. Towards a TENCompetence ePortfolio

    Directory of Open Access Journals (Sweden)

    Adriana J. Berlanga

    2008-07-01

    Full Text Available This article argues that the TENCompetence ePortfolio definition should integrate rhetorical, pedagogical, social, and technical perspectives. The rhetorical perspective is needed to show the learner’s competences, achievements and history; the pedagogical perspective aims at supporting learner’s self-reflection, through the definition of competences mastered, review and creation of (new competence development plans, and assessment of competences; the social perspective aims at fostering interaction and social help support; and the technical perspective aims at supporting the other three perspectives. Guiding principles for the design of the TENCompetence ePortfolio are provided, and the aforementioned perspectives detailed.

  16. Purpose and Pedagogy: A Conceptual Model for an ePortfolio

    Science.gov (United States)

    Buyarski, Catherine A.; Aaron, Robert W.; Hansen, Michele J.; Hollingsworth, Cynthia D.; Johnson, Charles A.; Kahn, Susan; Landis, Cynthia M.; Pedersen, Joan S.; Powell, Amy A.

    2015-01-01

    This conceptual model emerged from the need to balance multiple purposes and perspectives associated with developing an ePortfolio designed to promote student development and success. A comprehensive review of literature from various disciplines, theoretical frameworks, and scholarship, including self-authorship, reflection, ePortfolio pedagogy,…

  17. Cluster analysis for portfolio optimization

    OpenAIRE

    Vincenzo Tola; Fabrizio Lillo; Mauro Gallegati; Rosario N. Mantegna

    2005-01-01

    We consider the problem of the statistical uncertainty of the correlation matrix in the optimization of a financial portfolio. We show that the use of clustering algorithms can improve the reliability of the portfolio in terms of the ratio between predicted and realized risk. Bootstrap analysis indicates that this improvement is obtained in a wide range of the parameters N (number of assets) and T (investment horizon). The predicted and realized risk level and the relative portfolio compositi...

  18. Project Portfolio Management Applications Testing

    OpenAIRE

    Paul POCATILU

    2006-01-01

    Many IT companies are running project simultaneously. In order to achieve the best results, they have to group to the project in portfolios, and to use specific software that helps to manage them. Project portfolio management applications have a high degree of complexity and they are very important for the companies that are using it. This paper focuses on some characteristics of the testing process for project portfolio management applications

  19. Project Portfolio Management Applications Testing

    Directory of Open Access Journals (Sweden)

    Paul POCATILU

    2006-01-01

    Full Text Available Many IT companies are running project simultaneously. In order to achieve the best results, they have to group to the project in portfolios, and to use specific software that helps to manage them. Project portfolio management applications have a high degree of complexity and they are very important for the companies that are using it. This paper focuses on some characteristics of the testing process for project portfolio management applications

  20. Portfolio insurance using traded options

    OpenAIRE

    Machado-Santos, Carlos

    2001-01-01

    Literature concerning the institutional use of options indicates that the main purpose of option trading is to provide investors with the opportunity to create return distributions previously unavailable, considering that options provide the means to manipulate portfolio returns. In such a context, this study intends to analyse the returns of insured portfolios generated by hedging strategies on underlying stock portfolios. Because dynamic hedging is too expensive, we have hedged the stock po...

  1. Specific patterns in portfolio analysis

    Directory of Open Access Journals (Sweden)

    Gabriela Victoria ANGHELACHE

    2013-11-01

    Full Text Available In the mid-twentieth century, under an unprecedented growth of the business of trading in securities, the need to provide a modern framework for assessing the performance of portfolios of financial instruments was felt. To that effect, it is noted that over this period, more and more economists have attempted to develop statistical mathematical models that ensure the evaluation of profitability and portfolio risk securities. These models are considered to be part of "the modern portfolio theory".

  2. Future Learning Strategy and ePortfolios in Education

    Directory of Open Access Journals (Sweden)

    C. Dorninger

    2008-03-01

    Full Text Available The rapid change of the information andknowledge Society does no stop at education:communication, teaching and learning are changing due todigital media. Therefore at Austrian schools a “FutureLearning”- strategy was started in October 2007, where newforms of learning are underlined by new media and socialsoftware. This strategy will be presented. An important partof the strategy is the introduction of electronic Portfolios forstudents. Portfolios could be powerful tools to realizeindividualisation in formal education. There are two maintypes, the process portfolio for learning, working andreflection and the application portfolio for assessmentpurposes and job application. It is now possible to collectformal and informal competences and skills-orientedknowledge for the later professional career.

  3. Determining the band gap and mean kinetic energy of atoms from reflection electron energy loss spectra

    Energy Technology Data Exchange (ETDEWEB)

    Vos, M. [Atomic and Molecular Physics Laboratories, Research School of Physics and Engineering, Australian National University, Canberra ACT (Australia); Marmitt, G. G. [Atomic and Molecular Physics Laboratories, Research School of Physics and Engineering, Australian National University, Canberra ACT (Australia); Instituto de Fisica da Universidade Federal do Rio Grande do Sul, Avenida Bento Goncalves 9500, 91501-970 Porto Alegre, RS (Brazil); Finkelstein, Y. [Nuclear Research Center — Negev, Beer-Sheva 84190 (Israel); Moreh, R. [Physics Department, Ben-Gurion University of the Negev, Beer-Sheva 84105 (Israel)

    2015-09-14

    Reflection electron energy loss spectra from some insulating materials (CaCO{sub 3}, Li{sub 2}CO{sub 3}, and SiO{sub 2}) taken at relatively high incoming electron energies (5–40 keV) are analyzed. Here, one is bulk sensitive and a well-defined onset of inelastic excitations is observed from which one can infer the value of the band gap. An estimate of the band gap was obtained by fitting the spectra with a procedure that includes the recoil shift and recoil broadening affecting these measurements. The width of the elastic peak is directly connected to the mean kinetic energy of the atom in the material (Doppler broadening). The experimentally obtained mean kinetic energies of the O, C, Li, Ca, and Si atoms are compared with the calculated ones, and good agreement is found, especially if the effect of multiple scattering is taken into account. It is demonstrated experimentally that the onset of the inelastic excitation is also affected by Doppler broadening. Aided by this understanding, we can obtain a good fit of the elastic peak and the onset of inelastic excitations. For SiO{sub 2}, good agreement is obtained with the well-established value of the band gap (8.9 eV) only if it is assumed that the intensity near the edge scales as (E − E{sub gap}){sup 1.5}. For CaCO{sub 3}, the band gap obtained here (7 eV) is about 1 eV larger than the previous experimental value, whereas the value for Li{sub 2}CO{sub 3} (7.5 eV) is the first experimental estimate.

  4. Determining the band gap and mean kinetic energy of atoms from reflection electron energy loss spectra

    International Nuclear Information System (INIS)

    Vos, M.; Marmitt, G. G.; Finkelstein, Y.; Moreh, R.

    2015-01-01

    Reflection electron energy loss spectra from some insulating materials (CaCO 3 , Li 2 CO 3 , and SiO 2 ) taken at relatively high incoming electron energies (5–40 keV) are analyzed. Here, one is bulk sensitive and a well-defined onset of inelastic excitations is observed from which one can infer the value of the band gap. An estimate of the band gap was obtained by fitting the spectra with a procedure that includes the recoil shift and recoil broadening affecting these measurements. The width of the elastic peak is directly connected to the mean kinetic energy of the atom in the material (Doppler broadening). The experimentally obtained mean kinetic energies of the O, C, Li, Ca, and Si atoms are compared with the calculated ones, and good agreement is found, especially if the effect of multiple scattering is taken into account. It is demonstrated experimentally that the onset of the inelastic excitation is also affected by Doppler broadening. Aided by this understanding, we can obtain a good fit of the elastic peak and the onset of inelastic excitations. For SiO 2 , good agreement is obtained with the well-established value of the band gap (8.9 eV) only if it is assumed that the intensity near the edge scales as (E − E gap ) 1.5 . For CaCO 3 , the band gap obtained here (7 eV) is about 1 eV larger than the previous experimental value, whereas the value for Li 2 CO 3 (7.5 eV) is the first experimental estimate

  5. Financial Advice and Individual Investor Portfolio Performance

    NARCIS (Netherlands)

    Kramer, M.M.

    2012-01-01

    This paper investigates whether financial advisers add value to individual investors portfolio decisions by comparing portfolios of advised and self-directed (execution-only) Dutch individual investors. The results indicate significant differences in characteristics and portfolios between these

  6. Big-data reflection high energy electron diffraction analysis for understanding epitaxial film growth processes.

    Science.gov (United States)

    Vasudevan, Rama K; Tselev, Alexander; Baddorf, Arthur P; Kalinin, Sergei V

    2014-10-28

    Reflection high energy electron diffraction (RHEED) has by now become a standard tool for in situ monitoring of film growth by pulsed laser deposition and molecular beam epitaxy. Yet despite the widespread adoption and wealth of information in RHEED images, most applications are limited to observing intensity oscillations of the specular spot, and much additional information on growth is discarded. With ease of data acquisition and increased computation speeds, statistical methods to rapidly mine the data set are now feasible. Here, we develop such an approach to the analysis of the fundamental growth processes through multivariate statistical analysis of a RHEED image sequence. This approach is illustrated for growth of La(x)Ca(1-x)MnO(3) films grown on etched (001) SrTiO(3) substrates, but is universal. The multivariate methods including principal component analysis and k-means clustering provide insight into the relevant behaviors, the timing and nature of a disordered to ordered growth change, and highlight statistically significant patterns. Fourier analysis yields the harmonic components of the signal and allows separation of the relevant components and baselines, isolating the asymmetric nature of the step density function and the transmission spots from the imperfect layer-by-layer (LBL) growth. These studies show the promise of big data approaches to obtaining more insight into film properties during and after epitaxial film growth. Furthermore, these studies open the pathway to use forward prediction methods to potentially allow significantly more control over growth process and hence final film quality.

  7. Portfolio langagier en francais (Language Portfolios in French).

    Science.gov (United States)

    Laplante, Bernard; Christiansen, Helen

    2001-01-01

    Suggests that first-year college students learning French should create a language portfolio that contains documents that illustrate what they have learned in French, along with a brief statement of what linguistic skill the document demonstrates. The goal of the portfolio is to make students more aware of their own learning, their strengths, and…

  8. UK Household Portfolios

    OpenAIRE

    Banks, James; Smith, Sarah

    2000-01-01

    This paper presents a detailed analysis of the composition of household portfolios, using both aggregate and micro-data. Among the key findings are that: Most household wealth is held in the form of housing and pensions. Over time, there has been a shift away from housing towards financial assets, driven largely by the growth in life and pension funds. Liquid financial wealth (excluding life and pension funds) is not predominantly held in risky form. By far the most commonly held asset is an ...

  9. IT Portfolio Management

    DEFF Research Database (Denmark)

    Hansen, Lars Kristian; Kræmmergaard, Pernille

    2012-01-01

    As public organizations increasingly rely on IT-enabled development to provide faster cycle times and better services, IT Project Portfolio Management (IT PPM) has become a high priority issue. This research adopts engaged scholarship to investigate IT PPM practices within a large local government...... information about internal recourses, (4) Lack of operational goals to hold IT projects accountable, (5) No account of actual IT project costs. These results may be used to inform further research into IT PPM and to help managers improve IT PPM practices in public organizations in their effort of increase...

  10. Portfolios of quantum algorithms.

    Science.gov (United States)

    Maurer, S M; Hogg, T; Huberman, B A

    2001-12-17

    Quantum computation holds promise for the solution of many intractable problems. However, since many quantum algorithms are stochastic in nature they can find the solution of hard problems only probabilistically. Thus the efficiency of the algorithms has to be characterized by both the expected time to completion and the associated variance. In order to minimize both the running time and its uncertainty, we show that portfolios of quantum algorithms analogous to those of finance can outperform single algorithms when applied to the NP-complete problems such as 3-satisfiability.

  11. Determination of lead in clay enameled by X-ray fluorescence technique in Total reflection and by Scanning Electron Microscopy

    International Nuclear Information System (INIS)

    Zarazua O, G.; Carapia M, L.

    2000-01-01

    This work has the objective of determining lead free in the glazed commercial stewing pans using the X-ray fluorescence technique in Total reflection (FRX) and the observation and semiquantitative determination of lead by Analytical Scanning Electron Microscopy (ASEM). (Author)

  12. Æstetik og portfolio

    DEFF Research Database (Denmark)

    Hyldahl, Kirsten Kofod; Sams, Pernille; Egelund, Karen Stine

    2017-01-01

    Nærværende artikel præsenterer resultaterne af udviklingsprojektet ”Portfolio og æstetik” på pædagoguddannelsen i Hjørring. Projektet har til formål, gennem æstetisk formsprog, at stilladsere og fastholde de studerendes læreprocesser samt udvikle og implementere portfolio i studieaktiviteter på...

  13. The Functions and Benefits of the ePortfolio in Craft Education at the Primary Level

    Science.gov (United States)

    Saarinen, Auli; Seitamaa-Hakkarainen, Pirita; Hakkarainen, Kai

    2016-01-01

    The authors investigated primary school pupils' experiences using an electronic portfolio in their craft education for a three year period, from the 3rd grade until the end of the 5th grade. This article emphasizes the functions and the benefits of the ePortfolio method and outlines general user experiences based on pupil interviews (N = 38),…

  14. ePortfolios in Australian Higher Education Arts: Differences and Differentiations

    Science.gov (United States)

    Rowley, Jennifer; Bennett, Dawn

    2016-01-01

    This paper reports the findings of a project that investigated uses of electronic portfolios (ePortfolios) in the creative and performing arts at four Australian universities and raises four significant areas for discussion: engaging technologies as an ongoing requirement of planning, delivery and evaluation of teaching and learning in higher…

  15. Reflection-time-of-flight spectrometer for two-electron (e,2e) coincidence spectroscopy on surfaces

    International Nuclear Information System (INIS)

    Kirschner, J.; Kerherve, G.; Winkler, C.

    2008-01-01

    In this article, a novel time-of-flight spectrometer for two-electron-emission (e,2e/γ,2e) correlation spectroscopy from surfaces at low electron energies is presented. The spectrometer consists of electron optics that collect emitted electrons over a solid angle of approximately 1 sr and focus them onto a multichannel plate using a reflection technique. The flight time of an electron with kinetic energy of E kin ≅25 eV is around 100 ns. The corresponding time- and energy resolution are typically ≅1 ns and ≅0.65 eV, respectively. The first (e,2e) data obtained with the present setup from a LiF film are presented

  16. An unbalanced portfolio.

    Science.gov (United States)

    Federsel, Hans-Jurgen

    2009-06-01

    An excellent demonstration of how meaningful and valuable conferences devoted to the topic of project and portfolio management in the pharmaceutical industry can be, was given at an event organized in Barcelona, September 2008. Thus, over this 2-day meeting the delegates were updated on the state of the art in this wide-reaching area from speakers representing an array of companies; from small, relatively new players, via mid-sized, to established large and big pharmas. One common theme that emerged was the importance of assessing the value of drug projects as correctly as possible, especially under the current financial climate and the many challenges facing the industry. Furthermore, experiences from constructing portfolios with the aim to minimize risk and maximize return on investment were shared alongside mathematical approaches to obtain the data required for this purpose and accounts of the pleasures and hardships working in a global context and in partnership constellations. Copyright 2009 Prous Science, S.A.U. or its licensors. All rights reserved.

  17. Regularizing portfolio optimization

    International Nuclear Information System (INIS)

    Still, Susanne; Kondor, Imre

    2010-01-01

    The optimization of large portfolios displays an inherent instability due to estimation error. This poses a fundamental problem, because solutions that are not stable under sample fluctuations may look optimal for a given sample, but are, in effect, very far from optimal with respect to the average risk. In this paper, we approach the problem from the point of view of statistical learning theory. The occurrence of the instability is intimately related to over-fitting, which can be avoided using known regularization methods. We show how regularized portfolio optimization with the expected shortfall as a risk measure is related to support vector regression. The budget constraint dictates a modification. We present the resulting optimization problem and discuss the solution. The L2 norm of the weight vector is used as a regularizer, which corresponds to a diversification 'pressure'. This means that diversification, besides counteracting downward fluctuations in some assets by upward fluctuations in others, is also crucial because it improves the stability of the solution. The approach we provide here allows for the simultaneous treatment of optimization and diversification in one framework that enables the investor to trade off between the two, depending on the size of the available dataset.

  18. Regularizing portfolio optimization

    Science.gov (United States)

    Still, Susanne; Kondor, Imre

    2010-07-01

    The optimization of large portfolios displays an inherent instability due to estimation error. This poses a fundamental problem, because solutions that are not stable under sample fluctuations may look optimal for a given sample, but are, in effect, very far from optimal with respect to the average risk. In this paper, we approach the problem from the point of view of statistical learning theory. The occurrence of the instability is intimately related to over-fitting, which can be avoided using known regularization methods. We show how regularized portfolio optimization with the expected shortfall as a risk measure is related to support vector regression. The budget constraint dictates a modification. We present the resulting optimization problem and discuss the solution. The L2 norm of the weight vector is used as a regularizer, which corresponds to a diversification 'pressure'. This means that diversification, besides counteracting downward fluctuations in some assets by upward fluctuations in others, is also crucial because it improves the stability of the solution. The approach we provide here allows for the simultaneous treatment of optimization and diversification in one framework that enables the investor to trade off between the two, depending on the size of the available dataset.

  19. AVC/H.264 patent portfolio license

    Science.gov (United States)

    Skandalis, Dean A.

    2006-08-01

    MPEG LA, LLC offers a joint patent license for the AVC (a/k/a H.264) Standard (ISO/IEC IS 14496-10:2004). Like MPEG LA's other licenses, the AVC Patent Portfolio License is offered for the convenience of the marketplace as an alternative enabling users to access essential intellectual property owned by many patent holders under a single license rather than negotiating licenses with each of them individually. The AVC Patent Portfolio License includes essential patents owned by DAEWOO Electronics Corporation; Electronics and Telecommunications Research Institute (ETRI); France Telecom, societe anonyme; Fujitsu Limited; Hitachi, Ltd.; Koninklijke Philips Electronics N.V.; LG Electronics Inc.; Matsushita Electric Industrial Co., Ltd.; Microsoft Corporation; Mitsubishi Electric Corporation; Robert Bosch GmbH; Samsung Electronics Co., Ltd.; Sedna Patent Services, LLC; Sharp Kabushiki Kaisha; Siemens AG; Sony Corporation; The Trustees of Columbia University in the City of New York; Toshiba Corporation; UB Video Inc.; and Victor Company of Japan, Limited. Another is expected also to join as of August 1, 2006. MPEG LA's objective is to provide worldwide access to as much AVC essential intellectual property as possible for the benefit of AVC users. Therefore, any party that believes it has essential patents is welcome to submit them for evaluation of their essentiality and inclusion in the License if found essential.

  20. The Student Teacher Portfolio as Autobiography: Developing a Professional Identity.

    Science.gov (United States)

    Antonek, Janis L.; And Others

    1997-01-01

    Argues that student teacher portfolios are a viable, effective, appropriate tool for documenting teacher growth and development and for promoting reflective practice. Traces the unique paths of two pre-service foreign language teachers who constructed a professional identity from the historical and cultural conditions of their classroom…

  1. Maximizing the Impact of Portfolio Assessment through Effective Instructional Leadership.

    Science.gov (United States)

    Krusekopf, Frances; Karr-Kidwell, P. J.

    This study was designed as a field research project aimed at improving the method of assessing student learning at ACT Academy in the McKinney Independent School District, McKinney, Texas. Data and information were gathered and analyzed to see how the administration could improve the current student portfolio process. Reflections were completed by…

  2. Analysis of the Capability Portfolio Review (CPR)

    Science.gov (United States)

    2014-06-01

    10  2.4.1.1.  The Basics of Modern Portfolio Theory ...of Modern Portfolio Theory Much of modern portfolio management has been motivated by the influential work of Harry Markowitz (Markowitz, 1952) and...unsystematic risk associated with individual stocks, leaving only the generally market risk (Walls, 2004). The basic assumption of modern portfolio theory is

  3. 12 CFR 347.108 - Portfolio investments.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 4 2010-01-01 2010-01-01 false Portfolio investments. 347.108 Section 347.108... INTERNATIONAL BANKING § 347.108 Portfolio investments. (a) Portfolio investments. If a bank, directly or indirectly, acquires or holds an equity interest in a foreign organization as a portfolio investment and the...

  4. Portfolio optimization and performance evaluation

    DEFF Research Database (Denmark)

    Juhl, Hans Jørn; Christensen, Michael

    2013-01-01

    Based on an exclusive business-to-business database comprising nearly 1,000 customers, the applicability of portfolio analysis is documented, and it is examined how such an optimization analysis can be used to explore the growth potential of a company. As opposed to any previous analyses, optimal...... customer portfolios are determined, and it is shown how marketing decision-makers can use this information in their marketing strategies to optimize the revenue growth of the company. Finally, our analysis is the first analysis which applies portfolio based methods to measure customer performance......, and it is shown how these performance measures complement the optimization analysis....

  5. Parametric Portfolio Selection: Evaluating and Comparing to Markowitz Portfolios

    Directory of Open Access Journals (Sweden)

    Marcelo C. Medeiros

    2014-10-01

    Full Text Available In this paper we exploit the parametric portfolio optimization in the Brazilian market. Our data consists of monthly returns of 306 Brazilian stocks in the period between 2001 and 2013. We tested the model both in and out of sample and compared the results with the value and equal weighted portfolios and with a Markowitz based portfolio. We performed statistical inference in the parametric optimization using bootstrap techniques in order to build the parameters empirical distributions. Our results showed that the parametric optimization is a very efficient technique out of sample. It consistently showed superior results when compared with the VW, EW and Markowitz portfolios even when transaction costs were included. Finally, we consider the parametric approach to be very flexible to the inclusion of constraints in weights, transaction costs and listing and delisting of stocks.

  6. Portfolio i Praksis

    DEFF Research Database (Denmark)

    Saltofte, Margit; Krill, Cecilia

    . Præsentationsfolien fokuserer på at præsentere et færdigt produkt eller resultat, mens arbejdsportfolien har fokus på proces, refleksion og læring. Til denne forskel knytter sig desuden helt naturligt en sondring imellem det delte og det private. Hvor præsentationsportfolio per definition er åben og har en modtager i...... sigte, er arbejdsportfolien i udgangspunktet lukket og privat. Det vil sige at man selv udvælger, hvad der skal ses af fx vejleder eller medstuderende – og hvad, der skal forblive privat. Portfolio i Praksis tilbyder desuden en række håndgribelige øvelser, der kan bruges som hjælp til at understøtte det...

  7. IT Portfolio Management

    DEFF Research Database (Denmark)

    Hansen, Lars Kristian; Kræmmergaard, Pernille

    2012-01-01

    information about internal recourses, (4) Lack of operational goals to hold IT projects accountable, (5) No account of actual IT project costs. These results may be used to inform further research into IT PPM and to help managers improve IT PPM practices in public organizations in their effort of increase......As public organizations increasingly rely on IT-enabled development to provide faster cycle times and better services, IT Project Portfolio Management (IT PPM) has become a high priority issue. This research adopts engaged scholarship to investigate IT PPM practices within a large local government...... on the theory’s distinction between different modes of control five problems in control is identified: (1) weak accountability processes between the political and the administrative level, (2) weak accountability processes between director level and the IT executives, (3) IT projects established on incomplete...

  8. AREVA's nuclear reactors portfolio

    International Nuclear Information System (INIS)

    Marincic, A.

    2009-01-01

    A reasonable assumption for the estimated new build market for the next 25 years is over 340 GWe net. The number of prospect countries is growing almost each day. To address this new build market, AREVA is developing a comprehensive portfolio of reactors intended to meet a wide range of power requirements and of technology choices. The EPR reactor is the flagship of the fleet. Intended for large power requirements, the four first EPRs are being built in Finland, France and China. Other countries and customers are in view, citing just two examples: the Usa where the U.S. EPR has been selected as the technology of choice by several U.S utilities; and the United Kingdom where the Generic Design Acceptance process of the EPR design submitted by AREVA and EDF is well under way, and where there is a strong will to have a plant on line in 2017. For medium power ranges, the AREVA portfolio includes a boiling water reactor and a pressurized water reactor which both offer all of the advantages of an advanced plant design, with excellent safety performance and competitive power generation cost: -) KERENA (1250+ MWe), developed in collaboration with several European utilities, and in particular with Eon; -) ATMEA 1 (1100+ MWe), a 3-loop evolutionary PWR which is being developed by AREVA and Mitsubishi. AREVA is also preparing the future and is deeply involved into Gen IV concepts. It has developed the ANTARES modular HTR reactor (pre-conceptual design completed) and is building upon its vast Sodium Fast Reactor experience to take part into the development of the next prototype. (author)

  9. A Mean variance analysis of arbitrage portfolios

    Science.gov (United States)

    Fang, Shuhong

    2007-03-01

    Based on the careful analysis of the definition of arbitrage portfolio and its return, the author presents a mean-variance analysis of the return of arbitrage portfolios, which implies that Korkie and Turtle's results ( B. Korkie, H.J. Turtle, A mean-variance analysis of self-financing portfolios, Manage. Sci. 48 (2002) 427-443) are misleading. A practical example is given to show the difference between the arbitrage portfolio frontier and the usual portfolio frontier.

  10. From Metacognition to Practice Cognition: The DNP e-Portfolio to Promote Integrated Learning.

    Science.gov (United States)

    Anderson, Kelley M; DesLauriers, Patricia; Horvath, Catherine H; Slota, Margaret; Farley, Jean Nelson

    2017-08-01

    Educating Doctor of Nursing Practice (DNP) students for an increasingly complex health care environment requires novel applications of learning concepts and technology. A deliberate and thoughtful process is required to integrate concepts of the DNP program into practice paradigm changes to subsequently improve students' abilities to innovate solutions to complex practice problems. The authors constructed or participated in electronic portfolio development inspired by theories of metacognition and integrated learning. The objective was to develop DNP student's reflection, integration of concepts, and technological capabilities to foster the deliberative competencies related to the DNP Essentials and the foundations of the DNP program. The pedagogical process demonstrates how e-portfolios adapted into the doctoral-level curriculum for DNP students can address the Essentials and foster the development of metacognitive capabilities, which translates into practice changes. The authors suggest that this pedagogical approach has the potential to optimize reflective and deliberative competencies among DNP students. [J Nurs Educ. 2017;56(8):497-500.]. Copyright 2017, SLACK Incorporated.

  11. 78 FR 21045 - Confirmation, Portfolio Reconciliation, Portfolio Compression, and Swap Trading Relationship...

    Science.gov (United States)

    2013-04-09

    ... COMMODITY FUTURES TRADING COMMISSION 17 CFR Part 23 RIN 3038-AC96 Confirmation, Portfolio Reconciliation, Portfolio Compression, and Swap Trading Relationship Documentation Requirements for Swap Dealers... CFTC published final rules setting forth requirements for swap confirmation, portfolio reconciliation...

  12. Optimal Portfolios in Wishart Models and Effects of Discrete Rebalancing on Portfolio Distribution and Strategy Selection

    OpenAIRE

    Li, Zejing

    2012-01-01

    This dissertation is mainly devoted to the research of two problems - the continuous-time portfolio optimization in different Wishart models and the effects of discrete rebalancing on portfolio wealth distribution and optimal portfolio strategy.

  13. ePortfolio and learning styles in Nursing Education

    DEFF Research Database (Denmark)

    Nielsen, Kirsten; Helms, Niels Henrik; Pedersen, Birthe D.

    ePortfolio & learning styles in Nursing Education Background Examination of the literature shows both advantages and disadvantages in implementing ePortfolio and learning styles in Nursing Education. The students reflect on nursing practice as well as on their strengths and weaknesses...... priority than learning the practical craft of nursing in clinical settings. Insight into preferred learning style can be an advantage to both students and preceptors in attempt to promote students´ learning potential, but there are quite many different theoretical approaches and definitions of the concept...... of Nursing, VIA University College, DK wanted to intensify the differentiated guidance of students, and developed an ePortfolio which aim to facilitate four learning styles as described by Honey and Mumford. It was tested in a pilot project and now, a qualitative study of how learning is mediated in clinical...

  14. [Learning Portfolio: A New Strategy in Health Education].

    Science.gov (United States)

    Cheng, Yi-Chuan; Chen, Ching-Ju; Chang, Yu-Shan; Huang, Li-Chi

    2015-12-01

    Health education is the teaching by healthcare professionals of healthcare-related knowledge and skills to students in order that these students learn to help patients self-manage their disease and maintain health. This article introduces a new strategy in health education known as the learning portfolio and presents the theoretical basis and function of the learning portfolio and the current application of this approach in academic and health education. The learning portfolio is a learner-centric approach that collects evidence related to an individual's learning process systematically. This approach helps educators understand learner needs and conditions, while allowing the learner to observe his / her learning process in a manner that promotes self-reflection, continual inspection, and behavioral modification throughout the learning process. The results enhance the motivation of learners and strengthen their care confidence in accomplishing learning tasks.

  15. Reflection electron energy loss spectroscopy as efficient technique for the determination of optical properties of polystyrene intermixed with gold nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Deris, Jamileh [Department of Physics, Yasouj University, Yasouj 75918-74831 (Iran, Islamic Republic of); Hajati, Shaaker, E-mail: Hajati@mail.yu.ac.ir [Department of Physics, Yasouj University, Yasouj 75918-74831 (Iran, Islamic Republic of); Department of Semiconductors, Materials and Energy Research Center, Karaj 3177983634 (Iran, Islamic Republic of)

    2017-01-15

    Highlights: • Reflection Electron Energy Loss Spectroscopy of nano-metalized polymer. • Determination of real part of the dielectric function of nanostructured sample. • Determination of imaginary part of the dielectric function of nanostructured sample. • Determination of refractive index and coefficient of extinction of the sample. • Determination of reflection and absorption coefficients of nano-metalized Polymer. - Abstract: The electronic properties (electron inelastic cross section, energy loss function) of a nano-metalized polystyrene obtained by reflection electron energy loss spectroscopy (REELS) in a previous study [J. Deris, S. Hajati, S. Tougaard, V. Zaporojtchenko, Appl. Surf. Sci. 377 (2016) 44–47], which relies on the Yubero-Tougaard method, were used in the complementary application of Kramers-Kronig transformation to determine its optical properties such as the real part (ε{sub 1}) and imaginary part (ε{sub 2}) of the dielectric function (ε), refractive index (n), coefficients of extinction (k), reflection (R) and absorption (μ). The degree of intermixing of polystyrene thin film and gold nanoparticles of sizes 5.5 nm was controlled by annealing the sample to achieve a morphology in which the nanoparticles were homogeneously distributed within polystyrene. It is worth noting that no data are available on the optical properties of metalized polymers such as gold nanoparticles intermixed with polystyrene. Therefore, this work is of high importance in terms of both the sample studied here and the method applied. The advantage of the method applied here is that no information on the lateral distribution of the nanocomposite sample is required. This means that the REELS technique has been presented here to suitably, efficiently and easily obtain the optical properties of such nano-metalized polymer in which the metal nanoparticles have been vertically well distributed (homogeneous in depth). Therefore, for vertically homogeneous and

  16. Essays on Rational Portfolio Theory

    DEFF Research Database (Denmark)

    Nielsen, Simon Ellersgaard

    market prices, we findonly a very modest improvement in portfolio wealth over the corresponding strategy whichonly trades in bonds and stocks. Optimal Hedge Tracking Portfolios in a Limit Order Book. In this paper we developa control theoretic solution to the manner in which a portfolio manager optimally...... shouldtrack a targeted D, given that he wishes to hedge a short position in European call optionsthe underlying of which is traded in a limit order book. Specifically, we are interested in theinterplay between posting limit and market orders respectively: when should the portfoliomanager do what (and at what......’s theory of optimal portfolio selection for wealth maximisingagents. In this paper we present a systematic analysis of the optimal asset allocation in aderivative-free market for the Heston model, the 3/2 model, and a Fong Vasicek type model.Under the assumption that the market price of risk...

  17. Robust Portfolio Optimization Using Pseudodistances.

    Science.gov (United States)

    Toma, Aida; Leoni-Aubin, Samuela

    2015-01-01

    The presence of outliers in financial asset returns is a frequently occurring phenomenon which may lead to unreliable mean-variance optimized portfolios. This fact is due to the unbounded influence that outliers can have on the mean returns and covariance estimators that are inputs in the optimization procedure. In this paper we present robust estimators of mean and covariance matrix obtained by minimizing an empirical version of a pseudodistance between the assumed model and the true model underlying the data. We prove and discuss theoretical properties of these estimators, such as affine equivariance, B-robustness, asymptotic normality and asymptotic relative efficiency. These estimators can be easily used in place of the classical estimators, thereby providing robust optimized portfolios. A Monte Carlo simulation study and applications to real data show the advantages of the proposed approach. We study both in-sample and out-of-sample performance of the proposed robust portfolios comparing them with some other portfolios known in literature.

  18. RISK LOAN PORTFOLIO OPTIMIZATION MODEL BASED ON CVAR RISK MEASURE

    Directory of Open Access Journals (Sweden)

    Ming-Chang LEE

    2015-07-01

    Full Text Available In order to achieve commercial banks liquidity, safety and profitability objective requirements, loan portfolio risk analysis based optimization decisions are rational allocation of assets.  The risk analysis and asset allocation are the key technology of banking and risk management.  The aim of this paper, build a loan portfolio optimization model based on risk analysis.  Loan portfolio rate of return by using Value-at-Risk (VaR and Conditional Value-at-Risk (CVaR constraint optimization decision model reflects the bank's risk tolerance, and the potential loss of direct control of the bank.  In this paper, it analyze a general risk management model applied to portfolio problems with VaR and CVaR risk measures by using Using the Lagrangian Algorithm.  This paper solves the highly difficult problem by matrix operation method.  Therefore, the combination of this paper is easy understanding the portfolio problems with VaR and CVaR risk model is a hyperbola in mean-standard deviation space.  It is easy calculation in proposed method.

  19. Application of Markowitz Portfolio Theory by Building Optimal Portfolio on the US Stock Market

    OpenAIRE

    Širůček, Martin; Křen, Lukáš

    2015-01-01

    ŠIRŮČEK MARTIN, KŘEN LUKÁŠ. 2015. Application of Markowitz Portfolio Theory by Building Optimal Portfolio on the US Stock Market. Acta Universitatis Agriculturae et Silviculturae Mendelianae Brunensis, 63(4): 1375–1386. This paper is focused on building investment portfolios by using the Markowitz Portfolio Theory (MPT). Derivation based on the Capital Asset Pricing Model (CAPM) is used to calculate the weights of individual securities in portfolios. The calculated portfolios include a po...

  20. Information Acquisition and Portfolio Performance

    OpenAIRE

    Guiso, Luigi; Jappelli, Tullio

    2006-01-01

    Rational investors perceive correctly the value of financial information. Investment in information is therefore rewarded with a higher Sharpe ratio. Overconfident investors overstate the quality of their own information, and thus attain a lower Sharpe ratio. We contrast the implications of the two models using a unique survey of customers of an Italian leading bank with portfolio data and measures of financial information. We find that the portfolio Sharpe ratio is negatively associated with...

  1. Different Variants of Fundamental Portfolio

    Directory of Open Access Journals (Sweden)

    Tarczyński Waldemar

    2014-06-01

    Full Text Available The paper proposes the fundamental portfolio of securities. This portfolio is an alternative for the classic Markowitz model, which combines fundamental analysis with portfolio analysis. The method’s main idea is based on the use of the TMAI1 synthetic measure and, in limiting conditions, the use of risk and the portfolio’s rate of return in the objective function. Different variants of fundamental portfolio have been considered under an empirical study. The effectiveness of the proposed solutions has been related to the classic portfolio constructed with the help of the Markowitz model and the WIG20 market index’s rate of return. All portfolios were constructed with data on rates of return for 2005. Their effectiveness in 2006- 2013 was then evaluated. The studied period comprises the end of the bull market, the 2007-2009 crisis, the 2010 bull market and the 2011 crisis. This allows for the evaluation of the solutions’ flexibility in various extreme situations. For the construction of the fundamental portfolio’s objective function and the TMAI, the study made use of financial and economic data on selected indicators retrieved from Notoria Serwis for 2005.

  2. Measuring New Product Portfolio Innovativeness: How Differences in Scale Width and Evaluator Perspectives Affect its Relationship with Performance

    DEFF Research Database (Denmark)

    Schultz, Carsten; Salomo, Søren; Talke, Katrin

    2013-01-01

    Portfolio innovativeness is a central variable in innovation management. However, the impact of portfolio innovativeness on new product development (NPD) performance is unclear, which may partly be due to the construct’s multifaceted nature. Different facets may reflect different degrees of innov...

  3. Portfolios as "Learning Companions" for Children and a Means to Support and Assess Language Learning in the Primary School

    Science.gov (United States)

    Jones, Jane

    2012-01-01

    This article explores the idea of portfolios as a way to collect evidence of pupils' learning and achievement in their language learning in the primary school. The emphasis is on portfolio work as an active and reflective process to underpin and support learning and to show evidence of achievement and progression. Pupil choice and reflexivity are…

  4. Development of a web database portfolio system with PACS connectivity for undergraduate health education and continuing professional development.

    Science.gov (United States)

    Ng, Curtise K C; White, Peter; McKay, Janice C

    2009-04-01

    Increasingly, the use of web database portfolio systems is noted in medical and health education, and for continuing professional development (CPD). However, the functions of existing systems are not always aligned with the corresponding pedagogy and hence reflection is often lost. This paper presents the development of a tailored web database portfolio system with Picture Archiving and Communication System (PACS) connectivity, which is based on the portfolio pedagogy. Following a pre-determined portfolio framework, a system model with the components of web, database and mail servers, server side scripts, and a Query/Retrieve (Q/R) broker for conversion between Hypertext Transfer Protocol (HTTP) requests and Q/R service class of Digital Imaging and Communication in Medicine (DICOM) standard, is proposed. The system was piloted with seventy-seven volunteers. A tailored web database portfolio system (http://radep.hti.polyu.edu.hk) was developed. Technological arrangements for reinforcing portfolio pedagogy include popup windows (reminders) with guidelines and probing questions of 'collect', 'select' and 'reflect' on evidence of development/experience, limitation in the number of files (evidence) to be uploaded, the 'Evidence Insertion' functionality to link the individual uploaded artifacts with reflective writing, capability to accommodate diversity of contents and convenient interfaces for reviewing portfolios and communication. Evidence to date suggests the system supports users to build their portfolios with sound hypertext reflection under a facilitator's guidance, and with reviewers to monitor students' progress providing feedback and comments online in a programme-wide situation.

  5. The electrical resistivity of rough thin films: A model based on electron reflection at discrete step edges

    Science.gov (United States)

    Zhou, Tianji; Zheng, Pengyuan; Pandey, Sumeet C.; Sundararaman, Ravishankar; Gall, Daniel

    2018-04-01

    The effect of the surface roughness on the electrical resistivity of metallic thin films is described by electron reflection at discrete step edges. A Landauer formalism for incoherent scattering leads to a parameter-free expression for the resistivity contribution from surface mound-valley undulations that is additive to the resistivity associated with bulk and surface scattering. In the classical limit where the electron reflection probability matches the ratio of the step height h divided by the film thickness d, the additional resistivity Δρ = √{3 /2 } /(g0d) × ω/ξ, where g0 is the specific ballistic conductance and ω/ξ is the ratio of the root-mean-square surface roughness divided by the lateral correlation length of the surface morphology. First-principles non-equilibrium Green's function density functional theory transport simulations on 1-nm-thick Cu(001) layers validate the model, confirming that the electron reflection probability is equal to h/d and that the incoherent formalism matches the coherent scattering simulations for surface step separations ≥2 nm. Experimental confirmation is done using 4.5-52 nm thick epitaxial W(001) layers, where ω = 0.25-1.07 nm and ξ = 10.5-21.9 nm are varied by in situ annealing. Electron transport measurements at 77 and 295 K indicate a linear relationship between Δρ and ω/(ξd), confirming the model predictions. The model suggests a stronger resistivity size effect than predictions of existing models by Fuchs [Math. Proc. Cambridge Philos. Soc. 34, 100 (1938)], Sondheimer [Adv. Phys. 1, 1 (1952)], Rossnagel and Kuan [J. Vac. Sci. Technol., B 22, 240 (2004)], or Namba [Jpn. J. Appl. Phys., Part 1 9, 1326 (1970)]. It provides a quantitative explanation for the empirical parameters in these models and may explain the recently reported deviations of experimental resistivity values from these models.

  6. The use of e-portfolio in a linear algebra course

    Directory of Open Access Journals (Sweden)

    María Isabel García-Planas

    2016-03-01

    Full Text Available The use of e-portfolio becomes more common learning and student assessment; and this is due to the need for teachers to enhance students’ autonomy. The use of e-portfolio helps students to reflect on their own learning process. Lectures to large groups should not be limited only to classes, but must foster active learning, and in this regard, the introduction of the e-portfolio is a good tool because it stimulates collaborative and cooperative work among students and in turn encourages feedback with the teacher. To apply active methodologies during 2014-15 has been introduced in the course of the preparation of Linear Algebra comprehensive e-portfolio. To prepare the work of the e-portfolio the teacher had to clearly define the objectives that must be achieved by the students, and has had to plan in an understandable manner the tasks that the students can work independently outside the classroom. For the realization of the e-portfolio have been used different platforms. Each third of the students worked with a different platform, through AteneaLabs that it has provided templates in order that each student make their own e-portfolio, as well as it provide all necessary manuals. The platforms used were: Mahara, Exabis, WordPress and Google Sites. Formative assessment of the e-portfolio has been made from different rubrics defined in in the course syllabus and known by students since the beginning of the course.

  7. Fostering EFL learners’ autonomy in light of portfolio assessment: Exploring the potential impact of gender

    Directory of Open Access Journals (Sweden)

    Mahmood Hashemian

    2013-07-01

    Full Text Available The purpose of this study was to investigate the impact of portfolio assessment as a process-oriented mechanism on the autonomy of Iranian advanced EFL learners. A particular concern was to examine the potential effect of gender on portfolio assessment by taking the learners’ writing ability into account. The participants were 80 male and female advanced EFL learners to whom the Learner Autonomy Questionnaire (Kashefian, 2002 was administered to check their homogeneity prior to the study in terms of autonomy; a truncated form of a TOEFL test was also given to the participants to assess their language proficiency. The participants were then randomly divided into 4 groups: 2 experimental groups (20 females in class A and 20 males in class B and 2 control groups (20 females in class C and 20 males in class D. The portfolio assessment was integrated into the experimental groups to explore whether and to what extent their autonomy might enhance and also to investigate the possible effect of gender on portfolio assessment in writing ability. The portfolio assessment was based on the classroom portfolio model adopted from Hamp-Lyons and Condon (2000, consisting of 3 procedures: collection, selection, and reflection. In contrast, the control groups received the traditional assessment of writing. The data were analyzed using 2 independent samples t tests, mean, and the effect size. The results showed that the portfolio procedures considerably improved the autonomy of the participants. Also, gender had no impact on portfolio assessment.

  8. Universal portfolios generated by the Bregman divergence

    Science.gov (United States)

    Tan, Choon Peng; Kuang, Kee Seng

    2017-04-01

    The Bregman divergence of two probability vectors is a stronger form of the f-divergence introduced by Csiszar. Two versions of the Bregman universal portfolio are presented by exploiting the mean-value theorem. The explicit form of the Bregman universal portfolio generated by a function of a convex polynomial is derived and studied empirically. This portfolio can be regarded as another generalized of the well-known Helmbold portfolio. By running the portfolios on selected stock-price data sets from the local stock exchange, it is shown that it is possible to increase the wealth of the investor by using the portfolios in investment.

  9. Integral staggered point-matching method for millimeter-wave reflective diffraction gratings on electron cyclotron heating systems

    International Nuclear Information System (INIS)

    Xia, Donghui; Huang, Mei; Wang, Zhijiang; Zhang, Feng; Zhuang, Ge

    2016-01-01

    Highlights: • The integral staggered point-matching method for design of polarizers on the ECH systems is presented. • The availability of the integral staggered point-matching method is checked by numerical calculations. • Two polarizers are designed with the integral staggered point-matching method and the experimental results are given. - Abstract: The reflective diffraction gratings are widely used in the high power electron cyclotron heating systems for polarization strategy. This paper presents a method which we call “the integral staggered point-matching method” for design of reflective diffraction gratings. This method is based on the integral point-matching method. However, it effectively removes the convergence problems and tedious calculations of the integral point-matching method, making it easier to be used for a beginner. A code is developed based on this method. The calculation results of the integral staggered point-matching method are compared with the integral point-matching method, the coordinate transformation method and the low power measurement results. It indicates that the integral staggered point-matching method can be used as an optional method for the design of reflective diffraction gratings in electron cyclotron heating systems.

  10. Integral staggered point-matching method for millimeter-wave reflective diffraction gratings on electron cyclotron heating systems

    Energy Technology Data Exchange (ETDEWEB)

    Xia, Donghui [State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, 430074 Wuhan (China); Huang, Mei [Southwestern Institute of Physics, 610041 Chengdu (China); Wang, Zhijiang, E-mail: wangzj@hust.edu.cn [State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, 430074 Wuhan (China); Zhang, Feng [Southwestern Institute of Physics, 610041 Chengdu (China); Zhuang, Ge [State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, 430074 Wuhan (China)

    2016-10-15

    Highlights: • The integral staggered point-matching method for design of polarizers on the ECH systems is presented. • The availability of the integral staggered point-matching method is checked by numerical calculations. • Two polarizers are designed with the integral staggered point-matching method and the experimental results are given. - Abstract: The reflective diffraction gratings are widely used in the high power electron cyclotron heating systems for polarization strategy. This paper presents a method which we call “the integral staggered point-matching method” for design of reflective diffraction gratings. This method is based on the integral point-matching method. However, it effectively removes the convergence problems and tedious calculations of the integral point-matching method, making it easier to be used for a beginner. A code is developed based on this method. The calculation results of the integral staggered point-matching method are compared with the integral point-matching method, the coordinate transformation method and the low power measurement results. It indicates that the integral staggered point-matching method can be used as an optional method for the design of reflective diffraction gratings in electron cyclotron heating systems.

  11. Reflection of the energy structure of a tungsten monocrystal nearsurface area in the secondary electron spectrum

    International Nuclear Information System (INIS)

    Artamonov, O.M.; Smirnov, O.M.; Terekhov, A.N.

    1982-01-01

    Formation of secondary electron energy spectrum during emission from the crystal layer near the surface has been considered, at that layer energy structure can be different from volumetric energy structure. Its thickness depends on the predominant mechanism of electron scattering and is determined by corresponding phenomenological parameters. It is shown that the structure in the secondary electron spectrum appears in the case when energy structure of emitting monocrystal layer can not be described in the approximation of almost free electron gas and, as experimental investigations show, approaches energy zone structure of its volume. It is also show that in the case when the energy structure of the emitting layer is satisfactorily described with the model of almost free electron gas, the SE spectrum is characterized with traditional cascade minimum. Experimental investigation of SE energy distribution was carried out for the W monocrystalline face (110). It was established that distinct structure in the SE spectrum appears only after electrochemical polishing of the specimen surface. It is related to the appearance of ''far'' order in the monocrystal emission layer on initially disturbed tungsten surface during such treatment. Disturbance of tungsten monocrystal surface structure on its oxidation in O 2 atmosphere results in the appearance of the cascade maximum and disappearance of distinct peculiarities in the SE spectrum

  12. Channeling, volume reflection, and volume capture study of electrons in a bent silicon crystal

    Directory of Open Access Journals (Sweden)

    T. N. Wistisen

    2016-07-01

    Full Text Available We present the experimental data and analysis of experiments conducted at SLAC National Accelerator Laboratory investigating the processes of channeling, volume-reflection and volume-capture along the (111 plane in a strongly bent quasimosaic silicon crystal. These phenomena were investigated at 5 energies: 3.35, 4.2, 6.3, 10.5, and 14.0 GeV with a crystal with bending radius of 0.15 m, corresponding to curvatures of 0.053, 0.066, 0.099, 0.16, and 0.22 times the critical curvature, respectively. Based on the parameters of fitting functions we have extracted important parameters describing the channeling process such as the dechanneling length, the angle of volume reflection, the surface transmission, and the widths of the distribution of channeled particles parallel and orthogonal to the plane.

  13. Quantitative analysis of reflection electron energy loss spectra to determine electronic and optical properties of Fe–Ni alloy thin films

    International Nuclear Information System (INIS)

    Tahir, Dahlang; Oh, Sukh Kun; Kang, Hee Jae; Tougaard, Sven

    2016-01-01

    Highlights: • Electronic and optical properties of Fe-Ni alloy thin films grown on Si (1 0 0) were studied via quantitative analyses of reflection electron energy loss spectra (REELS). • The energy loss functions (ELF) are dominated by a plasmon peak at 23.6 eV for Fe and moves gradually to lower energies in Fe-Ni alloys towards the bulk plasmon energy of Ni at 20.5 eV. • Fe has a strong effect on the dielectric and optical properties of Fe-Ni alloy thin films even for an alloy with 72% Ni. Electronic and optical properties of Fe-Ni alloy thin films grown on Si (1 0 0) were studied via quantitative analyses of reflection electron energy loss spectra (REELS). - Abstract: Electronic and optical properties of Fe–Ni alloy thin films grown on Si (1 0 0) by ion beam sputter deposition were studied via quantitative analyses of reflection electron energy loss spectra (REELS). The analysis was carried out by using the QUASES-XS-REELS and QUEELS-ε(k,ω)-REELS softwares to determine the energy loss function (ELF) and the dielectric functions and optical properties by analyzing the experimental spectra. For Ni, the ELF shows peaks around 3.6, 7.5, 11.7, 20.5, 27.5, 67 and 78 eV. The peak positions of the ELF for Fe_2_8Ni_7_2 are similar to those of Fe_5_1Ni_4_9, even though there is a small peak shift from 18.5 eV for Fe_5_1Ni_4_9 to 18.7 eV for Fe_2_8Ni_7_2. A plot of n, k, ε_1, and ε_2 shows that the QUEELS-ε(k,ω)-REELS software for analysis of REELS spectra is useful for the study of optical properties of transition metal alloys. For Fe–Ni alloy with high Ni concentration (Fe_2_8Ni_7_2), ε_1, and ε_2 have strong similarities with those of Fe. This indicates that the presence of Fe in the Fe–Ni alloy thin films has a strong effect.

  14. E-Portfolio Web-based for Students’ Internship Program Activities

    Science.gov (United States)

    Juhana, A.; Abdullah, A. G.; Somantri, M.; Aryadi, S.; Zakaria, D.; Amelia, N.; Arasid, W.

    2018-02-01

    Internship program is an important part in vocational education process to improve the quality of competent graduates. The complete work documentation process in electronic portfolio (e-Portfolio) platform will facilitate students in reporting the results of their work to both university and industry supervisor. The purpose of this research is to create a more easily accessed e-Portfolio which is appropriate for students and supervisors’ need in documenting their work and monitoring process. The method used in this research is fundamental research. This research is focused on the implementation of internship e-Portfolio features by demonstrating them to students who have conducted internship program. The result of this research is to create a proper web-based e-Portfolio which can be used to facilitate students in documenting the results of their work and aid supervisors in monitoring process during internship.

  15. MOSEP – More Self-Esteem With My E-Portfolio Development of a Train-the-Trainer Course for E-Portfolio Tutors

    OpenAIRE

    Buchberger , Gerlinde; Hilzensauer , Wolf; Hornung-Prähauser , Veronika

    2007-01-01

    This paper gives an insight into the MOSEP project, funded by the European Commission (Leonardo da Vinci Programme). The project focuses on the high dropout rates amongst young students (14-16) in the transition phase from middle to upper secondary school or into first vocational education. MOSEP addresses this problem by proposing to introduce the method of electronic learning and development portfolios (e-portfolios) specifically designed for effectively teaching and consulting this difficu...

  16. Ranges, Reflection and Secondary Electron Emission for keV Hydrogen Ions Incident on Solid N2

    DEFF Research Database (Denmark)

    Børgesen, P.; Sørensen, H.; Hao-Ming, Chen

    1983-01-01

    Ranges were measured for 0.67–3.3 keV/amu hydrogen and deuterium ions in solid N2. Comparisons with similar results for N2-gas confirm the previously observed large phase effect in the stopping cross section. Measurements of the secondary electron emission coefficient for bulk solid N2 bombarded...... by 0.67–9 keV/amu ions also seem to support such a phase effect. It is argued that we may also extract information about the charge state of reflected projectiles....

  17. The effect of a non-hermitian crystal potential on the scattering matrix in reflection electron diffraction

    International Nuclear Information System (INIS)

    Smith, A.E.; Josefsson, T.W.

    1994-01-01

    An extension to include general inelastic scattering effects is developed for the case of reflection electron diffraction scattering from surfaces. In this extension of work by Lynch and Moodie, it is shown how the resultant non-Hermitian matrix problem can be recast in a form that is suitable for computation. In particular, a computational method is outlined based on techniques developed by Eberlein for matrix diagonalisation using complex rotations and shears. The resultant methods are applied to the problem of Convergent Beam RHEED. 23 refs., 3 figs

  18. 77 FR 55903 - Confirmation, Portfolio Reconciliation, Portfolio Compression, and Swap Trading Relationship...

    Science.gov (United States)

    2012-09-11

    ... Vol. 77 Tuesday, No. 176 September 11, 2012 Part II Commodity Futures Trading Commission 17 CFR Part 23 Confirmation, Portfolio Reconciliation, Portfolio Compression, and Swap Trading Relationship... FUTURES TRADING COMMISSION 17 CFR Part 23 RIN 3038-AC96 Confirmation, Portfolio Reconciliation, Portfolio...

  19. Feedback using an ePortfolio for medicine long cases: quality not quantity.

    Science.gov (United States)

    Bleasel, Jane; Burgess, Annette; Weeks, Ruth; Haq, Inam

    2016-10-21

    The evidence for the positive impact of an electronic Portfolio (ePortfolio) on feedback in medicine is mixed. An ePortfolio for medical long cases in a Graduate Medical Program was developed. The purpose of this study was to explore the perceptions of medical students and faculty of the impact of the ePortfolio on the feedback process. In total, 130 Year 3 medical students, and six faculty participated in the study. This is a mixed methods study, using a combination of both quantitative and qualitative approaches. Quantitative methods were used to quantify the number of long cases performed. Qualitative methods were used to explore the relationship between quantity and quality of feedback, and provide a rich understanding of both students' and faculty's experience and perceptions of the ePortfolio. Students received a variable quantity of feedback at each of the three studied clinical schools, with an average of between 4 - 5.4 feedback episodes per student. Feedback that was constructive, specific and timely and delivered by a senior academic was important. Quantity was not an essential factor, with two episodes of detailed feedback reported to be adequate. The barriers to the use of the ePortfolio were technical aspects of the platform that interfered with student engagement. Feedback using the ePortfolio for medical long cases is a valuable tool providing a senior clinician delivers detailed, constructive and personalized feedback in a timely fashion. The ePortfolio system needs to be user-friendly to engage students.

  20. Portfolio optimization with mean-variance model

    Science.gov (United States)

    Hoe, Lam Weng; Siew, Lam Weng

    2016-06-01

    Investors wish to achieve the target rate of return at the minimum level of risk in their investment. Portfolio optimization is an investment strategy that can be used to minimize the portfolio risk and can achieve the target rate of return. The mean-variance model has been proposed in portfolio optimization. The mean-variance model is an optimization model that aims to minimize the portfolio risk which is the portfolio variance. The objective of this study is to construct the optimal portfolio using the mean-variance model. The data of this study consists of weekly returns of 20 component stocks of FTSE Bursa Malaysia Kuala Lumpur Composite Index (FBMKLCI). The results of this study show that the portfolio composition of the stocks is different. Moreover, investors can get the return at minimum level of risk with the constructed optimal mean-variance portfolio.

  1. Network versus portfolio structure in financial systems

    Science.gov (United States)

    Kobayashi, Teruyoshi

    2013-10-01

    The question of how to stabilize financial systems has attracted considerable attention since the global financial crisis of 2007-2009. Recently, Beale et al. [Proc. Natl. Acad. Sci. USA 108, 12647 (2011)] demonstrated that higher portfolio diversity among banks would reduce systemic risk by decreasing the risk of simultaneous defaults at the expense of a higher likelihood of individual defaults. In practice, however, a bank default has an externality in that it undermines other banks’ balance sheets. This paper explores how each of these different sources of risk, simultaneity risk and externality, contributes to systemic risk. The results show that the allocation of external assets that minimizes systemic risk varies with the topology of the financial network as long as asset returns have negative correlations. In the model, a well-known centrality measure, PageRank, reflects an appropriately defined “infectiveness” of a bank. An important result is that the most infective bank needs not always to be the safest bank. Under certain circumstances, the most infective node should act as a firewall to prevent large-scale collective defaults. The introduction of a counteractive portfolio structure will significantly reduce systemic risk.

  2. Reflections on hard X-ray photon-in/photon-out spectroscopy for electronic structure studies

    Energy Technology Data Exchange (ETDEWEB)

    Glatzel, Pieter, E-mail: glatzel@esrf.fr [European Synchrotron Radiation Facility, 6 Rue Jules Horowitz, 38043 Grenoble (France); Weng, Tsu-Chien; Kvashnina, Kristina; Swarbrick, Janine; Sikora, Marcin [European Synchrotron Radiation Facility, 6 Rue Jules Horowitz, 38043 Grenoble (France); Gallo, Erik [European Synchrotron Radiation Facility, 6 Rue Jules Horowitz, 38043 Grenoble (France); Department of Inorganic, Physical and Materials Chemistry, INSTM Reference Center and NIS Centre of Excellence, Università di Torino, Via P. Giuria 7, I-10125 Torino (Italy); Smolentsev, Nikolay [European Synchrotron Radiation Facility, 6 Rue Jules Horowitz, 38043 Grenoble (France); Research Center for Nanoscale Structure of Matter, Southern Federal University, str. Zorge 5, 344090 Rostov-on-Don (Russian Federation); Mori, Roberto Alonso [European Synchrotron Radiation Facility, 6 Rue Jules Horowitz, 38043 Grenoble (France)

    2013-06-15

    Highlights: ► Overview of some recent developments in hard X-ray RXES/RIXS. ► Evaluation of spectral line broadening in RXES/RIXS. ► Modelling of RXES/RIXS by ground state DFT calculations. ► Discussion on when HERFD provides a good approximation to XAS. -- Abstract: An increasing community of researchers in various fields of natural sciences is combining X-ray absorption with X-ray emission spectroscopy (XAS–XES) to study electronic structure. With the applications becoming more diverse, the objectives and the requirements in photon-in/photon-out spectroscopy are becoming broader. It is desirable to find simple experimental protocols, robust data reduction and theoretical tools that help the experimentalist to understand their data and learn about the electronic structure. This article presents a collection of considerations on non-resonant and resonant XES with the aim to guide the experimentalist to make good use of this technique.

  3. An investigation of the reflection of low energy electrons from the surfaces of layered transition metal dichalcogenides

    International Nuclear Information System (INIS)

    Smith, A.E.; Mohamed, M.H.; Wohlenberg, T.; Johnson, E.; Chadderton, L.T.; Moeller, P.J.

    1980-01-01

    Experimental measurements, using the total current spectroscopy (TCS) technique, on the energy dependence of the reflection of low energy electrons from clean surfaces of layered transition metal dichalcogenides are reported for the molybdenum semiconductor compounds 2H-MoS 2 and 2H-MoSe 2 . A simple model calculation involving both elastic and inelastic scattering is presented and correspondence established with the experimental spectra. In this picture information on the electronic band structure of the materials can then be extracted from the single particle component of the inelastic scattering. The model is extended to show that a feature in the 2H-MoS 2 experimental spectrum may be attributed to the excitation of an intermediate plasmon. (Auth.)

  4. An experimental investigation of the reflection of low energy electrons from surfaces of 2H-MoS2

    International Nuclear Information System (INIS)

    Komolov, S.A.; Chadderton, L.T.

    1978-01-01

    Experiments are described in which a new technique - total current spectroscopy (TCS) - has been used to investigate the energy dependence of the reflection of low energy electrons from clean surfaces of the naturally occuring mineral molybdenite (2H-MoS 2 ). A theory involving both elastic and inelastic scattering of electrons is applied to a band structure calculated for molybdenite by Mattheiss. With relatively few approximations the results of numerical calculations for a TCS spectrum from molybdenite agree surprisingly well with experiment. It is suggested that TCS will prove to be a convenient and sensitive tool for the probing of energy structures in other solid surfaces. For the transition metal dichalcogenide series it should be possible to observe systematic changes in TCS spectra associated with changes in band structure, and subsequently to predict details in the density of states distributions using iterative computer procedures. (Auth.)

  5. Reflective optical system for time-resolved electron bunch measurements at PITZ

    Energy Technology Data Exchange (ETDEWEB)

    Rosbach, K; Baehr, J [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Roensch-Schulenburg, J [Hamburg Univ. (Germany). Inst. fuer Experimentalphysik

    2011-01-15

    The Photo-Injector Test facility at DESY, Zeuthen site (PITZ), produces pulsed electron beams with low transverse emittance and is equipped with diagnostic devices for measuring various electron bunch properties, including the longitudinal and transverse electron phase space distributions. The longitudinal bunch structure is recorded using a streak camera located outside the accelerator tunnel, connected to the diagnostics in the beam-line stations by an optical system of about 30 m length. This system mainly consists of telescopes of achromatic lenses, which transport the light pulses and image them onto the entrance slit of the streak camera. Due to dispersion in the lenses, the temporal resolution degrades during transport. This article presents general considerations for time-resolving optical systems as well as simulations and measurements of specific candidate systems. It then describes the development of an imaging system based on mirror telescopes which will improve the temporal resolution, with an emphasis on off-axis parabolic mirror systems working at unit magnification. A hybrid system of lenses and mirrors will serve as a proof of principle. (orig.)

  6. Deformed exponentials and portfolio selection

    Science.gov (United States)

    Rodrigues, Ana Flávia P.; Guerreiro, Igor M.; Cavalcante, Charles Casimiro

    In this paper, we present a method for portfolio selection based on the consideration on deformed exponentials in order to generalize the methods based on the gaussianity of the returns in portfolio, such as the Markowitz model. The proposed method generalizes the idea of optimizing mean-variance and mean-divergence models and allows a more accurate behavior for situations where heavy-tails distributions are necessary to describe the returns in a given time instant, such as those observed in economic crises. Numerical results show the proposed method outperforms the Markowitz portfolio for the cumulated returns with a good convergence rate of the weights for the assets which are searched by means of a natural gradient algorithm.

  7. Sygeplejestuderendes brug af portfolio i klinisk undervisning

    DEFF Research Database (Denmark)

    Hjorth, Anne Charlotte Overgaard; Bruhn, Helle

    2014-01-01

    Brugen af portfolio var mangelfuld, men et udviklingsprojekt i samarbejde med den kommunale sygepleje motiverede både sygeplejestuderende og kliniske vejledere til at anvende læringsdelen af portfolio aktivt.......Brugen af portfolio var mangelfuld, men et udviklingsprojekt i samarbejde med den kommunale sygepleje motiverede både sygeplejestuderende og kliniske vejledere til at anvende læringsdelen af portfolio aktivt....

  8. Dynamic Portfolio Strategy Using Clustering Approach.

    Science.gov (United States)

    Ren, Fei; Lu, Ya-Nan; Li, Sai-Ping; Jiang, Xiong-Fei; Zhong, Li-Xin; Qiu, Tian

    2017-01-01

    The problem of portfolio optimization is one of the most important issues in asset management. We here propose a new dynamic portfolio strategy based on the time-varying structures of MST networks in Chinese stock markets, where the market condition is further considered when using the optimal portfolios for investment. A portfolio strategy comprises two stages: First, select the portfolios by choosing central and peripheral stocks in the selection horizon using five topological parameters, namely degree, betweenness centrality, distance on degree criterion, distance on correlation criterion and distance on distance criterion. Second, use the portfolios for investment in the investment horizon. The optimal portfolio is chosen by comparing central and peripheral portfolios under different combinations of market conditions in the selection and investment horizons. Market conditions in our paper are identified by the ratios of the number of trading days with rising index to the total number of trading days, or the sum of the amplitudes of the trading days with rising index to the sum of the amplitudes of the total trading days. We find that central portfolios outperform peripheral portfolios when the market is under a drawup condition, or when the market is stable or drawup in the selection horizon and is under a stable condition in the investment horizon. We also find that peripheral portfolios gain more than central portfolios when the market is stable in the selection horizon and is drawdown in the investment horizon. Empirical tests are carried out based on the optimal portfolio strategy. Among all possible optimal portfolio strategies based on different parameters to select portfolios and different criteria to identify market conditions, 65% of our optimal portfolio strategies outperform the random strategy for the Shanghai A-Share market while the proportion is 70% for the Shenzhen A-Share market.

  9. Dynamic Portfolio Strategy Using Clustering Approach.

    Directory of Open Access Journals (Sweden)

    Fei Ren

    Full Text Available The problem of portfolio optimization is one of the most important issues in asset management. We here propose a new dynamic portfolio strategy based on the time-varying structures of MST networks in Chinese stock markets, where the market condition is further considered when using the optimal portfolios for investment. A portfolio strategy comprises two stages: First, select the portfolios by choosing central and peripheral stocks in the selection horizon using five topological parameters, namely degree, betweenness centrality, distance on degree criterion, distance on correlation criterion and distance on distance criterion. Second, use the portfolios for investment in the investment horizon. The optimal portfolio is chosen by comparing central and peripheral portfolios under different combinations of market conditions in the selection and investment horizons. Market conditions in our paper are identified by the ratios of the number of trading days with rising index to the total number of trading days, or the sum of the amplitudes of the trading days with rising index to the sum of the amplitudes of the total trading days. We find that central portfolios outperform peripheral portfolios when the market is under a drawup condition, or when the market is stable or drawup in the selection horizon and is under a stable condition in the investment horizon. We also find that peripheral portfolios gain more than central portfolios when the market is stable in the selection horizon and is drawdown in the investment horizon. Empirical tests are carried out based on the optimal portfolio strategy. Among all possible optimal portfolio strategies based on different parameters to select portfolios and different criteria to identify market conditions, 65% of our optimal portfolio strategies outperform the random strategy for the Shanghai A-Share market while the proportion is 70% for the Shenzhen A-Share market.

  10. The Effects of Portfolio Use in Teaching Report Writing: EFL Students' Perspective

    OpenAIRE

    Hussein Taha Assaggaf; Yousef Salem Bamahra

    2016-01-01

    Portfolio has widely been used in various areas including second language writing. The purpose of this study is to investigate the views of students in using portfolio in teaching technical report-writing. The participants are computer science students enrolled in a report writing course at a university in Yemen. For data collection, the study used three techniques; namely, group discussions, written reflections and a short questionnaire. The findings showed participants' positive views towar...

  11. Application of Markowitz Portfolio Theory by Building Optimal Portfolio on the US Stock Market

    Directory of Open Access Journals (Sweden)

    Martin Širůček

    2015-01-01

    Full Text Available This paper is focused on building investment portfolios by using the Markowitz Portfolio Theory (MPT. Derivation based on the Capital Asset Pricing Model (CAPM is used to calculate the weights of individual securities in portfolios. The calculated portfolios include a portfolio copying the benchmark made using the CAPM model, portfolio with low and high beta coefficients, and a random portfolio. Only stocks were selected for the examined sample from all the asset classes. Stocks in each portfolio are put together according to predefined criteria. All stocks were selected from Dow Jones Industrial Average (DJIA index which serves as a benchmark, too. Portfolios were compared based on their risk and return profiles. The results of this work will provide general recommendations on the optimal approach to choose securities for an investor’s portfolio.

  12. Band gap and defect states of MgO thin films investigated using reflection electron energy loss spectroscopy

    Directory of Open Access Journals (Sweden)

    Sung Heo

    2015-07-01

    Full Text Available The band gap and defect states of MgO thin films were investigated by using reflection electron energy loss spectroscopy (REELS and high-energy resolution REELS (HR-REELS. HR-REELS with a primary electron energy of 0.3 keV revealed that the surface F center (FS energy was located at approximately 4.2 eV above the valence band maximum (VBM and the surface band gap width (EgS was approximately 6.3 eV. The bulk F center (FB energy was located approximately 4.9 eV above the VBM and the bulk band gap width was about 7.8 eV, when measured by REELS with 3 keV primary electrons. From a first-principles calculation, we confirmed that the 4.2 eV and 4.9 eV peaks were FS and FB, induced by oxygen vacancies. We also experimentally demonstrated that the HR-REELS peak height increases with increasing number of oxygen vacancies. Finally, we calculated the secondary electron emission yields (γ for various noble gases. He and Ne were not influenced by the defect states owing to their higher ionization energies, but Ar, Kr, and Xe exhibited a stronger dependence on the defect states owing to their small ionization energies.

  13. Elucidation of the electronic states in polyethylene glycol by attenuated Total reflectance spectroscopy in the far-ultraviolet region

    Science.gov (United States)

    Ueno, Nami; Wakabayashi, Tomonari; Morisawa, Yusuke

    2018-05-01

    We measured the attenuated total reflectance-far ultraviolet (ATR-FUV) spectra of poly(ethylene glycol) (PEG; average molecular weights of 200, 300, and 400) and related materials in the liquid state in the 145-200-nm wavelength region. For appropriately assigning the absorption bands, we also performed theoretical simulation of the unit-number dependent electronic spectra. The FUV spectra of PEGs contain three bands, which are assigned to the transitions between n(CH2OCH2)-3s Rydberg state (176 nm), n(CH2OCH2)-3p Rydberg state (163 nm), and n(OH)-3p Rydberg state (153 nm). Since the contribution of n(OH) decreases compared to n(CH2OCH2) with increase in the number of units, the ratios of the molar absorption coefficients, ε, at 153 nm relative to 163 nm, decrease. On the other hand, the ratio of ε at 176 nm to that at 163 nm increases with increase in the number of units, because of the difference in the number of unoccupied orbitals in the transitions. The calculated results suggest that n orbitals form two electronic bands. In the upper band, the electrons expand over the ether chain, whereas in the lower band, the electrons are localized in the terminal OH in the PEGs.

  14. Feature selection for portfolio optimization

    DEFF Research Database (Denmark)

    Bjerring, Thomas Trier; Ross, Omri; Weissensteiner, Alex

    2016-01-01

    Most portfolio selection rules based on the sample mean and covariance matrix perform poorly out-of-sample. Moreover, there is a growing body of evidence that such optimization rules are not able to beat simple rules of thumb, such as 1/N. Parameter uncertainty has been identified as one major....... While most of the diversification benefits are preserved, the parameter estimation problem is alleviated. We conduct out-of-sample back-tests to show that in most cases different well-established portfolio selection rules applied on the reduced asset universe are able to improve alpha relative...

  15. Managing the New Product Portfolio

    DEFF Research Database (Denmark)

    Larsson, Flemming

    2008-01-01

    Product development companies are increasingly confronted with an unforgiving global marketplace, which urges the top management to pursue every product development opportunity that appears on the road. This situation incurs an important question: Which product development opportunities should a ....... The contributions encourage an improved understanding of the portfolio management concept and support industry professionals in their efforts to compose and continuously maintain a commercially strong product development portfolio.......Product development companies are increasingly confronted with an unforgiving global marketplace, which urges the top management to pursue every product development opportunity that appears on the road. This situation incurs an important question: Which product development opportunities should...

  16. Portfolios and the market geometry

    Science.gov (United States)

    Eleutério, Samuel; Araújo, Tanya; Vilela Mendes, R.

    2014-09-01

    A geometric analysis of return time series, performed in the past, implied that most of the systematic information in the market is contained in a space of small dimension. Here we have explored subspaces of this space to find out the relative performance of portfolios formed from companies that have the largest projections in each one of the subspaces. As expected, it was found that the best performance portfolios are associated with some of the small eigenvalue subspaces and not to the dominant dimensions. This is found to occur in a systematic fashion over an extended period (1990-2008).

  17. Application of Project Portfolio Management

    Science.gov (United States)

    Pankowska, Malgorzata

    The main goal of the chapter is the presentation of the application project portfolio management approach to support development of e-Municipality and public administration information systems. The models of how people publish and utilize information on the web have been transformed continually. Instead of simply viewing on static web pages, users publish their own content through blogs and photo- and video-sharing slides. Analysed in this chapter, ICT (Information Communication Technology) projects for municipalities cover the mixture of the static web pages, e-Government information systems, and Wikis. So, for the management of the ICT projects' mixtures the portfolio project management approach is proposed.

  18. Purchasing portfolio usage and purchasing sophistication

    NARCIS (Netherlands)

    Gelderman, C.J.; Weele, van A.J.

    2005-01-01

    Purchasing portfolio models have caused considerable controversy in literature. Many advantages and disadvantages have been put forward, revealing a strong disagreement on the merits of portfolio models. This study addresses the question whether or not the use of purchasing portfolio models should

  19. Hierarchical Portfolio Management: Theory and Applications

    NARCIS (Netherlands)

    H. Ning (Haikun)

    2007-01-01

    textabstractUnder his own preference, how should an investor coordinate the asset managers such that his aggregated portfolio is optimized? The efficiency of each managed sub portfolio and the aggregation of all the sub portfolios are the 2 main underlying problems considered in this dissertation.

  20. Modern Portfolio Theory: Some Main Results

    OpenAIRE

    Müller, Heinz H.

    2017-01-01

    This article summarizes some main results in modern portfolio theory. First, the Markowitz approach is presented. Then the capital asset pricing model is derived and its empirical testability is discussed. Afterwards Neumann-Morgenstern utility theory is applied to the portfolio problem. Finally, it is shown how optimal risk allocation in an economy may lead to portfolio insurance

  1. Household portfolios and implicit risk aversion

    NARCIS (Netherlands)

    Bucciol, A.; Miniaci, R.

    2008-01-01

    We derive from a sample of US households the distribution of the risk aversion implicit in their portfolio choice. Our estimate minimizes the distance between the certainty equivalent return generated with observed portfolios and portfolios that are optimal in a mean-variance framework. Taking into

  2. Quantitative investment strategies and portfolio management

    NARCIS (Netherlands)

    Guo, J.

    2012-01-01

    This book contains three essays on alternative investments and portfolio management. Taking from a portfolio investor’s perspective, the first essay analyzes the portfolio implication of investing in hedge funds when there is a hedge fund lockup period. The second essay studies the investment

  3. Formal Method of Description Supporting Portfolio Assessment

    Science.gov (United States)

    Morimoto, Yasuhiko; Ueno, Maomi; Kikukawa, Isao; Yokoyama, Setsuo; Miyadera, Youzou

    2006-01-01

    Teachers need to assess learner portfolios in the field of education. However, they need support in the process of designing and practicing what kind of portfolios are to be assessed. To solve the problem, a formal method of describing the relations between the lesson forms and portfolios that need to be collected and the relations between…

  4. The Impact of Transaction Costs on Rebalancing an Investment Portfolio in Portfolio Optimization

    OpenAIRE

    B. Marasović; S. Pivac; S. V. Vukasović

    2015-01-01

    Constructing a portfolio of investments is one of the most significant financial decisions facing individuals and institutions. In accordance with the modern portfolio theory maximization of return at minimal risk should be the investment goal of any successful investor. In addition, the costs incurred when setting up a new portfolio or rebalancing an existing portfolio must be included in any realistic analysis. In this paper rebalancing an investment portfolio in the pr...

  5. Delegated Portfolio Management and Optimal Allocation of Portfolio Managers

    DEFF Research Database (Denmark)

    Christensen, Michael; Vangsgaard Christensen, Michael; Gamskjaer, Ken

    2015-01-01

    In this article, we investigate whether the application of the mean-variance framework on portfolio manager allocation offers any out-of-sample benefits compared to a naïve strategy of equal weighting. Based on an exclusive data-set of high-net-worth (HNW) investors, we utilize a wide variety of ...

  6. Optimal Portfolio Selection Under Concave Price Impact

    International Nuclear Information System (INIS)

    Ma Jin; Song Qingshuo; Xu Jing; Zhang Jianfeng

    2013-01-01

    In this paper we study an optimal portfolio selection problem under instantaneous price impact. Based on some empirical analysis in the literature, we model such impact as a concave function of the trading size when the trading size is small. The price impact can be thought of as either a liquidity cost or a transaction cost, but the concavity nature of the cost leads to some fundamental difference from those in the existing literature. We show that the problem can be reduced to an impulse control problem, but without fixed cost, and that the value function is a viscosity solution to a special type of Quasi-Variational Inequality (QVI). We also prove directly (without using the solution to the QVI) that the optimal strategy exists and more importantly, despite the absence of a fixed cost, it is still in a “piecewise constant” form, reflecting a more practical perspective.

  7. Optimal Portfolio Selection Under Concave Price Impact

    Energy Technology Data Exchange (ETDEWEB)

    Ma Jin, E-mail: jinma@usc.edu [University of Southern California, Department of Mathematics (United States); Song Qingshuo, E-mail: songe.qingshuo@cityu.edu.hk [City University of Hong Kong, Department of Mathematics (Hong Kong); Xu Jing, E-mail: xujing8023@yahoo.com.cn [Chongqing University, School of Economics and Business Administration (China); Zhang Jianfeng, E-mail: jianfenz@usc.edu [University of Southern California, Department of Mathematics (United States)

    2013-06-15

    In this paper we study an optimal portfolio selection problem under instantaneous price impact. Based on some empirical analysis in the literature, we model such impact as a concave function of the trading size when the trading size is small. The price impact can be thought of as either a liquidity cost or a transaction cost, but the concavity nature of the cost leads to some fundamental difference from those in the existing literature. We show that the problem can be reduced to an impulse control problem, but without fixed cost, and that the value function is a viscosity solution to a special type of Quasi-Variational Inequality (QVI). We also prove directly (without using the solution to the QVI) that the optimal strategy exists and more importantly, despite the absence of a fixed cost, it is still in a 'piecewise constant' form, reflecting a more practical perspective.

  8. A Relationship Strategy Perspective on Relationship Portfolios

    DEFF Research Database (Denmark)

    Ritter, Thomas; Andersen, Henrik

    2014-01-01

    The paper develops a three-dimensional portfolio model for business relationships which distinguishes among six different categories. Based on assessments of customer profitability, customer commitment, and growth potential, the positioning of a given customer relationship in the portfolio allows...... managers to determine appropriate customer relationship strategies and appropriate performance indicators. Results from applying the portfolio model are reported and managerial implications and future research are discussed.......The paper develops a three-dimensional portfolio model for business relationships which distinguishes among six different categories. Based on assessments of customer profitability, customer commitment, and growth potential, the positioning of a given customer relationship in the portfolio allows...

  9. Performance of the reverse Helmbold universal portfolio

    Science.gov (United States)

    Tan, Choon Peng; Kuang, Kee Seng; Lee, Yap Jia

    2017-04-01

    The universal portfolio is an important investment strategy in a stock market where no stochastic model is assumed for the stock prices. The zero-gradient set of the objective function estimating the next-day portfolio which contains the reverse Kullback-Leibler order-alpha divergence is considered. From the zero-gradient set, the explicit, reverse Helmbold universal portfolio is obtained. The performance of the explicit, reverse Helmbold universal portfolio is studied by running them on some stock-price data sets from the local stock exchange. It is possible to increase the wealth of the investor by using these portfolios in investment.

  10. Portfolios: A Vehicle for Inquiry.

    Science.gov (United States)

    McMackin, Mary C.

    By blending elements of inquiry with the components of portfolios, learning and thinking in teacher preparation courses can be extended and possible tensions between "covering content" and allowing "open-ended investigation" can be mitigated. Over the years, the author mused about how she might nudge graduate students in her…

  11. Dynamic Portfolio Choice with Frictions

    DEFF Research Database (Denmark)

    Garleanu, Nicolae; Heje Pedersen, Lasse

    2016-01-01

    We show how portfolio choice can be modeled in continuous time with transitory and persistent transaction costs, multiple assets, multiple signals predicting returns, and general signal dynamics. The objective function is derived from the limit of discrete-time models with endogenous transaction...

  12. Teaching Sociology through Student Portfolios

    Science.gov (United States)

    Trepagnier, Barbara

    2004-01-01

    After several years of teaching Sociological Thought--an upper division course that focuses on classical, modern, and contemporary sociological theories--the author came across the idea of student portfolios. As a consequence, the course has undergone far-reaching changes. The content remains relatively intact; however, today the theory course…

  13. Adaptation portfolios in water management

    NARCIS (Netherlands)

    Aerts, J.C.J.H.; Botzen, W.J.W.; Werners, S.

    2015-01-01

    This study explores how Modern Portfolio Theory (MPT) can guide investment decisions in integrated water resources management (IWRM) and climate change adaptation under uncertainty. The objectives of the paper are to: (i) explain the concept of diversification to reduce risk, as formulated in MPT;

  14. [New portfolio, a users' manual].

    Science.gov (United States)

    Cougnoux, Nadège; Deken, Éric; Juif, Isabelle; Papas, Anne

    2015-10-01

    The portfolio, a tool for monitoring nursing students throughout their internship period, has now been modified. The new 2015 version can be used to monitor and trace the student's career as well as progress made. One of the major new points is the integration of an intermediate internship assessment. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  15. Robust Portfolio Optimization Using Pseudodistances

    Science.gov (United States)

    2015-01-01

    The presence of outliers in financial asset returns is a frequently occurring phenomenon which may lead to unreliable mean-variance optimized portfolios. This fact is due to the unbounded influence that outliers can have on the mean returns and covariance estimators that are inputs in the optimization procedure. In this paper we present robust estimators of mean and covariance matrix obtained by minimizing an empirical version of a pseudodistance between the assumed model and the true model underlying the data. We prove and discuss theoretical properties of these estimators, such as affine equivariance, B-robustness, asymptotic normality and asymptotic relative efficiency. These estimators can be easily used in place of the classical estimators, thereby providing robust optimized portfolios. A Monte Carlo simulation study and applications to real data show the advantages of the proposed approach. We study both in-sample and out-of-sample performance of the proposed robust portfolios comparing them with some other portfolios known in literature. PMID:26468948

  16. Portfolio selection with heavy tails

    NARCIS (Netherlands)

    Hyung, N.; Vries, de C.G.

    2007-01-01

    Consider the portfolio problem of choosing the mix between stocks and bonds under a downside risk constraint. Typically stock returns exhibit fatter tails than bonds corresponding to their greater downside risk. Downside risk criteria like the safety first criterion therefore often select corner

  17. Portfolio Selection with Heavy Tails

    NARCIS (Netherlands)

    N. Hyung (Namwon); C.G. de Vries (Casper)

    2004-01-01

    textabstractConsider the portfolio problem of choosing the mix between stocks and bonds under a downside risk constraint. Typically stock returns exhibit fatter tails than bonds corresponding to their greater downside risk. Downside risk criteria like the safety first criterion therefore of ten

  18. Does health affect portfolio choice?

    Science.gov (United States)

    Love, David A; Smith, Paul A

    2010-12-01

    A number of recent studies find that poor health is empirically associated with a safer portfolio allocation. It is difficult to say, however, whether this relationship is truly causal. Both health status and portfolio choice are influenced by unobserved characteristics such as risk attitudes, impatience, information, and motivation, and these unobserved factors, if not adequately controlled for, can induce significant bias in the estimates of asset demand equations. Using the 1992-2006 waves of the Health and Retirement Study, we investigate how much of the connection between health and portfolio choice is causal and how much is due to the effects of unobserved heterogeneity. Accounting for unobserved heterogeneity with fixed effects and correlated random effects models, we find that health does not appear to significantly affect portfolio choice among single households. For married households, we find a small effect (about 2-3 percentage points) from being in the lowest of five self-reported health categories. Copyright © 2009 John Wiley & Sons, Ltd.

  19. Supply contract and portfolio insurance

    Science.gov (United States)

    Runsheng Yin; Bob Izlar

    2001-01-01

    The long-term growth of institutional timberland investments depends on the ability of timberland investment management organizations (TIMO) to deal effectively with securitization, leveraging, arbitraging, supply contracting, portfolio insurance, tax efficiency enhancement, and other issues. Financial engineering holds great promise for many of these issues. This...

  20. Turnover activity in wealth portfolios

    NARCIS (Netherlands)

    Castaldi, C.; Milakovic, M.

    2007-01-01

    We examine several subsets of the wealthiest individuals in the US and the UK that are compiled by Forbes Magazine and the Sunday Times. Since these are named subsets, we can calculate the returns to wealth portfolios, and calibrate a statistical equilibrium model of wealth distribution that

  1. Turnover activity in wealth portfolios

    NARCIS (Netherlands)

    Castaldi, Carolina; Milakovic, Mishael

    We examine several subsets of the wealthiest individuals in the US and the UK that are compiled by Forbes Magazine and the Sunday Times. Since these are named subsets, we can calculate the returns to wealth portfolios, and calibrate a statistical equilibrium model of wealth distribution that

  2. HEURISTIC APPROACHES FOR PORTFOLIO OPTIMIZATION

    OpenAIRE

    Manfred Gilli, Evis Kellezi

    2000-01-01

    The paper first compares the use of optimization heuristics to the classical optimization techniques for the selection of optimal portfolios. Second, the heuristic approach is applied to problems other than those in the standard mean-variance framework where the classical optimization fails.

  3. Optimal Portfolio Choice with Annuitization

    NARCIS (Netherlands)

    Koijen, R.S.J.; Nijman, T.E.; Werker, B.J.M.

    2006-01-01

    We study the optimal consumption and portfolio choice problem over an individual's life-cycle taking into account annuity risk at retirement. Optimally, the investor allocates wealth at retirement to nominal, inflation-linked, and variable annuities and conditions this choice on the state of the

  4. Household Portfolios in the Netherlands

    NARCIS (Netherlands)

    Alessie, R.J.M.; Hochgürtel, S.; van Soest, A.H.O.

    2000-01-01

    We describe and analyse the portfolio structure of Dutch households using micro panel data from the CentER Savings Survey, 1993-1998.The data allows for a distinction between many types of assets.Moreover, we have information on mortgage debt, consumer debt, etc.We analyse the composition of

  5. Managing a "N" Securities Portfolio

    Directory of Open Access Journals (Sweden)

    Costică Vlad

    2016-01-01

    For the application that will be described below, namely the management of a portfolio of eightsecurity bonds, a financial analyst should carry more than 10^15 computing operations. Thedemonstration focuses on the analysis of results and on summarizing the concepts used.

  6. Monitoring non-pseudomorphic epitaxial growth of spinel/perovskite oxide heterostructures by reflection high-energy electron diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Schütz, P.; Pfaff, F.; Scheiderer, P.; Sing, M.; Claessen, R. [Physikalisches Institut and Röntgen Center for Complex Material Systems (RCCM), Universität Würzburg, Am Hubland, D-97074 Würzburg (Germany)

    2015-02-09

    Pulsed laser deposition of spinel γ-Al{sub 2}O{sub 3} thin films on bulk perovskite SrTiO{sub 3} is monitored by high-pressure reflection high-energy electron diffraction (RHEED). The heteroepitaxial combination of two materials with different crystal structures is found to be inherently accompanied by a strong intensity modulation of bulk diffraction patterns from inelastically scattered electrons, which impedes the observation of RHEED intensity oscillations. Avoiding such electron surface-wave resonance enhancement by de-tuning the RHEED geometry allows for the separate observation of the surface-diffracted specular RHEED signal and thus the real-time monitoring of sub-unit cell two-dimensional layer-by-layer growth. Since these challenges are essentially rooted in the difference between film and substrate crystal structure, our findings are of relevance for the growth of any heterostructure combining oxides with different crystal symmetry and may thus facilitate the search for novel oxide heterointerfaces.

  7. Detection and quantitative determination of heavy metals in electronic cigarette refill liquids using Total Reflection X-ray Fluorescence Spectrometry.

    Science.gov (United States)

    Kamilari, Eleni; Farsalinos, Konstantinos; Poulas, Konstantinos; Kontoyannis, Christos G; Orkoula, Malvina G

    2018-06-01

    Electronic cigarettes are considered healthier alternatives to conventional cigarettes containing tobacco. They produce vapor through heating of the refill liquids (e-liquids) which consist of propylene glycol, vegetable glycerin, nicotine (in various concentrations), water and flavoring agents. Heavy metals may enter the refill liquid during the production, posing a risk for consumer's health due to their toxicity. The objective of the present study was the development of a methodology for the detection and quantitative analysis of cadmium (Cd), lead (Pb), nickel (Ni), copper (Cu), arsenic (As) and chromium (Cr), employing Total Reflection X-Ray Fluorescence Spectroscopy (TXRF) as an alternative technique to ICP-MS or ICP-OES commonly used for this type of analysis. TXRF was chosen due to its advantages, which include short analysis time, promptness, simultaneous multi-element analysis capability and minimum sample preparation, low purchase and operational cost. The proposed methodology was applied to a large number of electronic cigarette liquids commercially available, as well as their constituents, in order to evaluate their safety. TXRF may be a valuable tool for probing heavy metals in electronic cigarette refill liquids to serve for the protection of human health. Copyright © 2018 Elsevier Ltd. All rights reserved.

  8. Comparison of Portfolio Selection and Performance: Shari’ah-Compliant and Socially Responsible Investment Portfolios

    Directory of Open Access Journals (Sweden)

    Mehmet Asutay

    2015-04-01

    Full Text Available This study examines the effect of Islamic screening criteria on Shari’ah-compliant portfolio selection and performance compared to Socially Responsible Investment (SRI portfolio. Each portfolio constructed from 15 stocks based on FTSE 100 using data from year 1997. Mean-variance portfolio optimization is employed with some financial ratios added as constraints for the Shari’ah portfolio. Annual expected return of each portfolio from 2008 to 2013 is used to calculate Sharpe’s ratio, Treynor ratio and Jensen’s alpha as the performance measurement tools. Macroeconomic variables are assessed using ordinary least square to examine whether they influence the portfolios’ expected returns or not. The result finds that Shari’ah portfolio has a better performance than SRI from year 2008 to 2010 shown by higher value of the measurement tools. However, from 2011 to 2013, SRI portfolio has better performance than Shari’ah portfolio

  9. Fast Focal Point Correction in Prism-Coupled Total Internal Reflection Scanning Imager Using an Electronically Tunable Lens

    Directory of Open Access Journals (Sweden)

    Chenggang Zhu

    2018-02-01

    Full Text Available Total internal reflection (TIR is useful for interrogating physical and chemical processes that occur at the interface between two transparent media. Yet prism-coupled TIR imaging microscopes suffer from limited sensing areas due to the fact that the interface (the object plane is not perpendicular to the optical axis of the microscope. In this paper, we show that an electrically tunable lens can be used to rapidly and reproducibly correct the focal length of an oblique-incidence scanning microscope (OI-RD in a prism-coupled TIR geometry. We demonstrate the performance of such a correction by acquiring an image of a protein microarray over a scan area of 4 cm2 with an effective resolution of less than 20 microns. The electronic focal length tuning eliminates the mechanical movement of the illumination lens in the scanning microscope and in turn the noise and background drift associated with the motion.

  10. Assessing the Development of Medical Students' Personal and Professional Skills by Portfolio.

    Science.gov (United States)

    Yielder, Jill; Moir, Fiona

    2016-01-01

    The introduction of a new domain of learning for Personal and Professional Skills in the medical program at the University of Auckland in New Zealand has involved the compilation of a portfolio for assessment. This departure from the traditional assessment methods predominantly used in the past has been challenging to design, introduce, and maintain as a relevant and authentic assessment method. We present the portfolio format along with the process for its introduction and appraise the challenges, strengths, and limitations of the approach within the context of the current literature. We then outline a cyclical model of evaluation used to monitor and fine-tune the portfolio tasks and implementation process, in response to student and assessor feedback. The portfolios have illustrated the level of insight, maturity, and synthesis of personal and professional qualities that students are capable of achieving. The Auckland medical program strives to foster these qualities in its students, and the portfolio provides an opportunity for students to demonstrate their reflective abilities. Moreover, the creation of a Personal and Professional Skills domain with the portfolio as its key assessment emphasizes the importance of reflective practice and personal and professional development and gives a clear message that these are fundamental longitudinal elements of the program.

  11. Assessing the Development of Medical Students’ Personal and Professional Skills by Portfolio

    Science.gov (United States)

    Yielder, Jill; Moir, Fiona

    2016-01-01

    The introduction of a new domain of learning for Personal and Professional Skills in the medical program at the University of Auckland in New Zealand has involved the compilation of a portfolio for assessment. This departure from the traditional assessment methods predominantly used in the past has been challenging to design, introduce, and maintain as a relevant and authentic assessment method. We present the portfolio format along with the process for its introduction and appraise the challenges, strengths, and limitations of the approach within the context of the current literature. We then outline a cyclical model of evaluation used to monitor and fine-tune the portfolio tasks and implementation process, in response to student and assessor feedback. The portfolios have illustrated the level of insight, maturity, and synthesis of personal and professional qualities that students are capable of achieving. The Auckland medical program strives to foster these qualities in its students, and the portfolio provides an opportunity for students to demonstrate their reflective abilities. Moreover, the creation of a Personal and Professional Skills domain with the portfolio as its key assessment emphasizes the importance of reflective practice and personal and professional development and gives a clear message that these are fundamental longitudinal elements of the program. PMID:29349315

  12. A far ultraviolet spectroscopic study of the reflectance, luminescence and electronic properties of SrMgF4 single crystals

    International Nuclear Information System (INIS)

    Ogorodnikov, I.N.; Pustovarov, V.A.; Omelkov, S.I.; Isaenko, L.I.; Yelisseyev, A.P.; Goloshumova, A.A.; Lobanov, S.I.

    2014-01-01

    The electronic properties of single crystals of SrMgF 4 have been determined using low-temperature (10–293 K) time-resolved vacuum ultraviolet synchrotron radiation spectroscopy, far ultraviolet (3.7–36 eV) reflectance spectra and calculations for the spectra of optical functions. The bandgap of investigated compound was found at E g =12.55eV, the energy threshold for creation of the unrelaxed excitons at E n=1 =11.37eV, and the low-energy fundamental absorption edge at 10.3 eV. Two groups of photoluminescence (PL) bands have been identified: the exciton-type emissions at 2.6–3.3 and 3.3–4.2 eV and defect-related emissions at 1.8–2.6 and 4.2–5.5 eV. It was shown that PL excitation (PLE) for the exciton-type emission bands occurs mainly at the low-energy tail of the fundamental absorption of the crystal with a maximum at 10.7 eV. At excitation energies above E g the energy transfer from the host lattice to the PL emission centers is inefficient. The paper discusses the origin of the excitonic-type PLE spectra taking into account the results of modeling the PLE spectra shape in the framework of a simple diffusion theory and surface energy losses. -- Highlights: • Far-ultraviolet reflection spectra of SrMgF 4 were studied. • Photoluminescence (PL) emission and PL excitation spectra were studied. • Optical function spectra were calculated on the basis of experimental data. • Electronic structure properties of undoped SrMgF 4 crystals were determined

  13. Identification of hydrogen and deuterium at the surface of water ice by reflection electron energy loss spectroscopy

    International Nuclear Information System (INIS)

    Yubero, F.; Toekesi, K.

    2009-01-01

    Complete text of publication follows. The study of elastically backscattered electrons from surfaces by reflection electron energy loss spectroscopy (REELS) has been recently recommended as an alternative technique to quantify the H content at the surface of a-C:H and polymer samples. This analysis is based on the fact that the energy loss of the incident electrons due to the recoil effect depends on the atomic mass of the particular atom present at the surface. The observed difference in recoil energies between H and O atoms (about 2 eV for 1.5 keV primary electrons) can be easily measured with standard electron spectrometers used in surface analysis. In this paper we go one step forward to explore if, with the same experimental approach, it is possible to differentiate between hydrogen and deuterium (D) in the surface region of a sample. This capability could be important for technological fields such as surface functionalization, where it is desired to distinguish between H and D at surfaces after interaction with labeled compounds. We have chosen normal and deuterated water as test labeled compounds because this polar molecule is of key importance in numerous surface reactions. It has been shown that H and D can be easily distinguished at the surface of water ice [4] using standard REELS measurements with 1000 - 1650 eV primary-electron energies, i.e., a surface analytical technique. Differences in recoil energies of the O - H and O - D atom pairs present in H 2 O and D 2 O have been found to agree with MC simulations (see Fig.1). There are many possible applications of H and D detection by REELS. Among many others, this study opens the possibility of nondestructive studies of deuterium-labeled atoms present or adsorbed on surfaces. For example, studies of H incorporation into a polymer or carbonbased surface after plasma activation with gas mixtures with several labeled molecules containing H atoms. Acknowledgements F.Y. thanks the Spanish Ministry of Science

  14. Improving the Automatic Inversion of Digital ISIS-2 Ionogram Reflection Traces into Topside Vertical Electron-Density Profiles

    Science.gov (United States)

    Benson, R. F.; Truhlik, V.; Huang, X.; Wang, Y.; Bilitza, D.

    2011-01-01

    The topside-sounders on the four satellites of the International Satellites for Ionospheric Studies (ISIS) program were designed as analog systems. The resulting ionograms were displayed on 35-mm film for analysis by visual inspection. Each of these satellites, launched between 1962 and 1971, produced data for 10 to 20 years. A number of the original telemetry tapes from this large data set have been converted directly into digital records. Software, known as the TOPside Ionogram Scalar with True-height (TOPIST) algorithm has been produced that enables the automatic inversion of ISIS-2 ionogram reflection traces into topside vertical electron-density profiles Ne(h). More than million digital Alouette/ISIS topside ionograms have been produced and over 300,000 are from ISIS 2. Many of these ISIS-2 ionograms correspond to a passive mode of operation for the detection of natural radio emissions and thus do not contain ionospheric reflection traces. TOPIST, however, is not able to produce Ne(h) profiles from all of the ISIS-2 ionograms with reflection traces because some of them did not contain frequency information. This information was missing due to difficulties encountered during the analog-to-digital conversion process in the detection of the ionogram frame-sync pulse and/or the frequency markers. Of the many digital topside ionograms that TOPIST was able to process, over 200 were found where direct comparisons could be made with Ne(h) profiles that were produced by manual scaling in the early days of the ISIS program. While many of these comparisons indicated excellent agreement (inversion process: (1) improve the quality of the digital ionogram database by remedying the missing frequency-information problem when possible, and (2) using the above-mentioned comparisons as teaching examples of how to improve the original TOPIST software.

  15. Applying Portfolio Theory to EU Electricity Planning and Policy-Making

    Energy Technology Data Exchange (ETDEWEB)

    Awerbuch, Shimon; Berger, Martin

    2003-02-01

    This study introduces mean-variance portfolio theory and evaluates its potential application to the development of efficient (optimal) European Union (EU-15) generating portfolios that enhance energy security and diversification objectives. The analysis extends to European countries the previous work done by Awerbuch in the US, and applies a significantly more detailed portfolio model that reflects the risk of the relevant generating cost streams: fuel, operation and maintenance and construction period costs. It illustrates the portfolio effects of different generating mixes. The study offers preliminary findings on the effects of including more renewable energy sources in the typical EU portfolio mix and suggests interesting directions for further study. The study arises from the perception that these standard, finance-oriented analyses may offer valuable enhancements to energy planning, and concepts of energy security and diversity. Clearly the combination of better portfolio construction and more accurate pricing should lead to more optimal decisions in the round. This study, therefore, represents an effort to complement traditional approaches and point researchers and planners into new territory. The results generally indicate that the existing and projected EU generating mixes are sub optimal - though slightly - from a risk-return perspective, which implies that feasible portfolios with lower cost and risk exist. These can be developed by adjusting the conventional mix and by including larger shares of wind or similar renewable technologies. The results of the portfolio analysis suggest that fixed cost technologies such as renewables must be a part of any efficient generating portfolio. Our assessment of all technologies is limited to risk and cost measures, although other benefits, including low externality costs and sustainability, are often cited for renewables.

  16. Automatic Trading Agent. RMT Based Portfolio Theory and Portfolio Selection

    Science.gov (United States)

    Snarska, M.; Krzych, J.

    2006-11-01

    Portfolio theory is a very powerful tool in the modern investment theory. It is helpful in estimating risk of an investor's portfolio, arosen from lack of information, uncertainty and incomplete knowledge of reality, which forbids a perfect prediction of future price changes. Despite of many advantages this tool is not known and not widely used among investors on Warsaw Stock Exchange. The main reason for abandoning this method is a high level of complexity and immense calculations. The aim of this paper is to introduce an automatic decision-making system, which allows a single investor to use complex methods of Modern Portfolio Theory (MPT). The key tool in MPT is an analysis of an empirical covariance matrix. This matrix, obtained from historical data, biased by such a high amount of statistical uncertainty, that it can be seen as random. By bringing into practice the ideas of Random Matrix Theory (RMT), the noise is removed or significantly reduced, so the future risk and return are better estimated and controlled. These concepts are applied to the Warsaw Stock Exchange Simulator {http://gra.onet.pl}. The result of the simulation is 18% level of gains in comparison with respective 10% loss of the Warsaw Stock Exchange main index WIG.

  17. A reverse Monte Carlo method for deriving optical constants of solids from reflection electron energy-loss spectroscopy spectra

    International Nuclear Information System (INIS)

    Da, B.; Sun, Y.; Ding, Z. J.; Mao, S. F.; Zhang, Z. M.; Jin, H.; Yoshikawa, H.; Tanuma, S.

    2013-01-01

    A reverse Monte Carlo (RMC) method is developed to obtain the energy loss function (ELF) and optical constants from a measured reflection electron energy-loss spectroscopy (REELS) spectrum by an iterative Monte Carlo (MC) simulation procedure. The method combines the simulated annealing method, i.e., a Markov chain Monte Carlo (MCMC) sampling of oscillator parameters, surface and bulk excitation weighting factors, and band gap energy, with a conventional MC simulation of electron interaction with solids, which acts as a single step of MCMC sampling in this RMC method. To examine the reliability of this method, we have verified that the output data of the dielectric function are essentially independent of the initial values of the trial parameters, which is a basic property of a MCMC method. The optical constants derived for SiO 2 in the energy loss range of 8-90 eV are in good agreement with other available data, and relevant bulk ELFs are checked by oscillator strength-sum and perfect-screening-sum rules. Our results show that the dielectric function can be obtained by the RMC method even with a wide range of initial trial parameters. The RMC method is thus a general and effective method for determining the optical properties of solids from REELS measurements.

  18. Portfolio optimization in electricity markets

    International Nuclear Information System (INIS)

    Liu, Min; Wu, Felix F.

    2007-01-01

    In a competitive electricity market, Generation companies (Gencos) face price risk and delivery risk that affect their profitability. Risk management is an important and essential part in the Genco's decision making. In this paper, risk management through diversification is considered. The problem of energy allocation between spot markets and bilateral contracts is formulated as a general portfolio optimization problem with a risk-free asset and n risky assets. Historical data of the PJM electricity market are used to demonstrate the approach. (author)

  19. Large deviations and portfolio optimization

    Science.gov (United States)

    Sornette, Didier

    Risk control and optimal diversification constitute a major focus in the finance and insurance industries as well as, more or less consciously, in our everyday life. We present a discussion of the characterization of risks and of the optimization of portfolios that starts from a simple illustrative model and ends by a general functional integral formulation. A major item is that risk, usually thought of as one-dimensional in the conventional mean-variance approach, has to be addressed by the full distribution of losses. Furthermore, the time-horizon of the investment is shown to play a major role. We show the importance of accounting for large fluctuations and use the theory of Cramér for large deviations in this context. We first treat a simple model with a single risky asset that exemplifies the distinction between the average return and the typical return and the role of large deviations in multiplicative processes, and the different optimal strategies for the investors depending on their size. We then analyze the case of assets whose price variations are distributed according to exponential laws, a situation that is found to describe daily price variations reasonably well. Several portfolio optimization strategies are presented that aim at controlling large risks. We end by extending the standard mean-variance portfolio optimization theory, first within the quasi-Gaussian approximation and then using a general formulation for non-Gaussian correlated assets in terms of the formalism of functional integrals developed in the field theory of critical phenomena.

  20. Public Project Portfolio Optimization under a Participatory Paradigm

    Directory of Open Access Journals (Sweden)

    Eduardo Fernandez

    2013-01-01

    Full Text Available A new democracy paradigm is emerging through participatory budgeting exercises, which can be defined as a public space in which the government and the society agree on how to adapt the priorities of the citizenship to the public policy agenda. Although these priorities have been identified and they are likely to be reflected in a ranking of public policy actions, there is still a challenge of solving a portfolio problem of public projects that should implement the agreed agenda. This work proposes two procedures for optimizing the portfolio of public actions with the information stemming from the citizen participatory exercise. The selection of the method depends on the information about preferences collected from the participatory group. When the information is sufficient, the method behaves as an instrument of legitimate democracy. The proposal performs very well in solving two real-size examples.

  1. Uncertain programming models for portfolio selection with uncertain returns

    Science.gov (United States)

    Zhang, Bo; Peng, Jin; Li, Shengguo

    2015-10-01

    In an indeterminacy economic environment, experts' knowledge about the returns of securities consists of much uncertainty instead of randomness. This paper discusses portfolio selection problem in uncertain environment in which security returns cannot be well reflected by historical data, but can be evaluated by the experts. In the paper, returns of securities are assumed to be given by uncertain variables. According to various decision criteria, the portfolio selection problem in uncertain environment is formulated as expected-variance-chance model and chance-expected-variance model by using the uncertainty programming. Within the framework of uncertainty theory, for the convenience of solving the models, some crisp equivalents are discussed under different conditions. In addition, a hybrid intelligent algorithm is designed in the paper to provide a general method for solving the new models in general cases. At last, two numerical examples are provided to show the performance and applications of the models and algorithm.

  2. Reel success creating demo reels and animation portfolios

    CERN Document Server

    Cabrera, Cheryl

    2013-01-01

    Are you an animator looking to get your foot in the door to the top studios?It's tough if you don't have a demo reel and portfolio that reflects your unique style and incredible talents.  The reception of that reel will make or break you; so it's no wonder that creating a demo reel can be such a daunting task.  Reel Success by Cheryl Cabrera can help.  This book guides you into putting the right content into your portfolio, how to cater to the right audience, and how to harness the power of social media and network effectively.  Accompanied by case studies of actual students

  3. Making sense with ePortfolios

    DEFF Research Database (Denmark)

    Poulsen, Bo Klindt; Dimsits, Miriam

    2017-01-01

    of the statements from the students concerning their understanding of ePortfolio processes are fundamentally questions of how to make sense of the ePortfolio tool, both in their professional and personal lives. This calls for a didactical stance with the teachers who use ePortfolios, based on empowerment through......This article discusses the question of making sense out of working with ePortfolio in adult education. The article presents the results of a small-scale survey among adults in continuing education who have worked with ePortfolio as the central didactic principle. It is argued that many...... meaning-making, in order for ePortfolios to make sense. It is suggested that two relevant didactic perspectives for making sense of the world can be found in theories of biographicity and metaphor work. Moreover, a strong didactic stance that supports sense-making must be based on a strong teacher role...

  4. Nurses' perceptions of e-portfolio use for on-the-job training in Taiwan.

    Science.gov (United States)

    Tsai, Pei-Rong; Lee, Ting-Ting; Lin, Hung-Ru; Lee-Hsieh, Jane; Mills, Mary Etta

    2015-01-01

    Electronic portfolios can be used to record user performance and achievements. Currently, clinical learning systems and in-service education systems lack integration of nurses' clinical performance records with their education or training outcomes. For nurses with less than 2 years' work experience (nursing postgraduate year), use of an electronic portfolio is essential. This study aimed to assess the requirements of using electronic portfolios in continuing nursing education for clinical practices. Fifteen nurses were recruited using a qualitative purposive sampling approach between April 2013 and May 2013. After obtaining participants' consent, data were collected in a conference room of the study hospital by one-on-one semistructured in-depth interviews. Through data analyses, the following five main themes related to electronic learning portfolios were identified: instant access to in-service education information, computerized nursing postgraduate year training manual, diversity of system functions and interface designs, need for sufficient computers, and protection of personal documents. Because electronic portfolios are beginning to be used in clinical settings, a well-designed education information system not only can meet the needs of nurses but also can facilitate their learning progress.

  5. Post-modern portfolio theory supports diversification in an investment portfolio to measure investment's performance

    OpenAIRE

    Rasiah, Devinaga

    2012-01-01

    This study looks at the Post-Modern Portfolio Theory that maintains greater diversification in an investment portfolio by using the alpha and the beta coefficient to measure investment performance. Post-Modern Portfolio Theory appreciates that investment risk should be tied to each investor's goals and the outcome of this goal did not symbolize economic of the financial risk. Post-Modern Portfolio Theory's downside measure generated a noticeable distinction between downside and upside volatil...

  6. I Thought This Was Going to Be a Waste of Time: How Portfolio Construction Can Support Student Learning from Project-Based Experiences

    Science.gov (United States)

    Turns, Jennifer; Cuddihy, Elisabeth; Guan, Zhiwei

    2010-01-01

    In this work, we sought to understand ways that students experienced a small-scale portfolio assignment provided to them as an opportunity reflect on their experiences in a project-based class. This work was motivated by research in various instructional contexts showing that portfolio construction results in important learning outcomes. We wanted…

  7. The Practical Application of E-Portfolios in K-12 Classrooms: An Exploration of Three Web 2.0 Tools by Three Teachers

    Science.gov (United States)

    Karlin, Michael; Ozogul, Gamze; Miles, Stacy; Heide, Saul

    2016-01-01

    Portfolios used in K-12 classrooms give students the opportunity to collect, showcase, and reflect upon the work they have completed throughout a class or program. With the advent of the digital age, e-portfolios have allowed for this process to be conducted online through the use of Web 2.0 tools, offering a number of advantages and features that…

  8. Portfolios with nonlinear constraints and spin glasses

    Science.gov (United States)

    Gábor, Adrienn; Kondor, I.

    1999-12-01

    In a recent paper Galluccio, Bouchaud and Potters demonstrated that a certain portfolio problem with a nonlinear constraint maps exactly onto finding the ground states of a long-range spin glass, with the concomitant nonuniqueness and instability of the optimal portfolios. Here we put forward geometric arguments that lead to qualitatively similar conclusions, without recourse to the methods of spin glass theory, and give two more examples of portfolio problems with convex nonlinear constraints.

  9. Correlation risk and optimal portfolio choice

    OpenAIRE

    Buraschi, Andrea; Porchia, Paolo; Trojani, Fabio

    2010-01-01

    We develop a new framework for multivariate intertemporal portfolio choice that allows us to derive optimal portfolio implications for economies in which the degree of correlation across industries, countries, or asset classes is stochastic. Optimal portfolios include distinct hedging components against both stochastic volatility and correlation risk. We find that the hedging demand is typically larger than in univariate models, and it includes an economically significant covariance hedging...

  10. Communication: On the calculation of time-dependent electron flux within the Born-Oppenheimer approximation: A flux-flux reflection principle

    Science.gov (United States)

    Albert, Julian; Hader, Kilian; Engel, Volker

    2017-12-01

    It is commonly assumed that the time-dependent electron flux calculated within the Born-Oppenheimer (BO) approximation vanishes. This is not necessarily true if the flux is directly determined from the continuity equation obeyed by the electron density. This finding is illustrated for a one-dimensional model of coupled electronic-nuclear dynamics. There, the BO flux is in perfect agreement with the one calculated from a solution of the time-dependent Schrödinger equation for the coupled motion. A reflection principle is derived where the nuclear BO flux is mapped onto the electronic flux.

  11. Mean-Reverting Portfolio With Budget Constraint

    Science.gov (United States)

    Zhao, Ziping; Palomar, Daniel P.

    2018-05-01

    This paper considers the mean-reverting portfolio design problem arising from statistical arbitrage in the financial markets. We first propose a general problem formulation aimed at finding a portfolio of underlying component assets by optimizing a mean-reversion criterion characterizing the mean-reversion strength, taking into consideration the variance of the portfolio and an investment budget constraint. Then several specific problems are considered based on the general formulation, and efficient algorithms are proposed. Numerical results on both synthetic and market data show that our proposed mean-reverting portfolio design methods can generate consistent profits and outperform the traditional design methods and the benchmark methods in the literature.

  12. Parametric Portfolio Policies with Common Volatility Dynamics

    DEFF Research Database (Denmark)

    Ergemen, Yunus Emre; Taamouti, Abderrahim

    A parametric portfolio policy function is considered that incorporates common stock volatility dynamics to optimally determine portfolio weights. Reducing dimension of the traditional portfolio selection problem significantly, only a number of policy parameters corresponding to first- and second......-order characteristics are estimated based on a standard method-of-moments technique. The method, allowing for the calculation of portfolio weight and return statistics, is illustrated with an empirical application to 30 U.S. industries to study the economic activity before and after the recent financial crisis....

  13. Low volatility sector-based portfolios: a South African case

    African Journals Online (AJOL)

    Black pointed out that when investors are restricted from using leverage or bor- ..... takes into account the correlation between the sectors in a portfolio. ..... 3The information ratio of a portfolio is the active premium (portfolio annualised return ...

  14. Portfolio Diversification with Commodity Futures: Properties of Levered Futures

    NARCIS (Netherlands)

    Woodard, J.D.; Egelkraut, T.M.; Garcia, P.; Pennings, J.M.E.

    2005-01-01

    Portfolio Diversification with Commodity Futures: Properties of Levered Futures This study extends previous work on the impact of commodity futures on portfolio performance by explicitly incorporating levered futures into the portfolio optimization problem. Using data on nine individual commodity

  15. Examining portfolio-based assessment in an upper-level biology course

    Science.gov (United States)

    Ziegler, Brittany Ann

    Historically, students have been viewed as empty vessels and passive participants in the learning process but students actually are active forming their own conceptions. One way student learning is impacted is through assessment. Alternative assessment, which contrasts traditional assessment methods, takes into account how students learn by promoting engagement and construction of knowledge This dissertation explores portfolio-based assessment, a method of alternative assessment, which requires students to compose a purposeful collection of work demonstrating their knowledge in an upper-level biology course. The research objectives include characterizing and contributing to the understanding of portfolio-based assessment in higher education, examining reflection and inquiry portfolio components, determining student knowledge of biological concepts, and investigating student integrative thinking through the transformation of reflections into concept webs One main finding includes the majority of reflections categorized as naive or novice in quality. There was no difference in quality of reflections among biological topic. There was a relatively equal amount of high and low cognitive level questions. Students' knowledge of biological concepts significantly increased from the beginning to end of the course. Student written reflections were transformed into concept webs to allow for examination of student integrative thinking. Concepts, relationships, and interconnections in concept webs showed variation but declined by the end of the semester This study is one of the first examining portfolio-based assessment in an upper-level biology course We do not contend that this method of assessment is the only way to promote student learning but portfolio-based assessment may be a tool that can transform science education but currently the role of portfolio-based assessment in science education remains unclear. Additional research needs to be conducted before we will fully

  16. Reliability of Portfolio: A Closer Look at Findings from Recent Publications

    Science.gov (United States)

    Oskay, Ozge Ozyalcin; Schallies, Michael; Morgil, Inci

    2008-01-01

    In this review article, conventional portfolio assessment and new developments in portfolio assessment are investigated. The concept of portfolio, portfolio building steps, contents of portfolio, evaluation of portfolio, advantages, disadvantages and concerns in using portfolio as well as validity and reliability of portfolio assessment are…

  17. In situ observation of low temperature growth of Ge on Si(1 1 1) by reflection high energy electron diffraction

    International Nuclear Information System (INIS)

    Grimm, Andreas; Fissel, Andreas; Bugiel, Eberhard; Wietler, Tobias F.

    2016-01-01

    Highlights: • Investigation of the initial stages of epitaxial growth of Ge on Si(1 1 1) in situ by RHEED. • Impact of growth temperature on strain evolution for temperatures between 200 °C and 400 °C. • Epitaxy with a high degree of structural perfection already at growth temperature of 200 °C. • Ordered interfacial dislocation networks already at 200 °C. • Tensile strain contribution of Si(1 1 1) 7 × 7-surface reconstruction to strain relaxation process for epitaxial growth of Ge. - Abstract: In this paper we investigate the initial stages of epitaxial growth of Ge on Si(1 1 1) and the impact of growth temperature on strain evolution in situ by reflection high energy electron diffraction (RHEED) for temperatures between 200 °C and 400 °C. The change in surface morphology from a flat wetting layer to subsequent islanding that is characteristic for Stranski–Krastanov growth is monitored by spot intensity analysis. The corresponding critical layer thickness is determined to 3.1 < d c < 3.4 ML. In situ monitoring of the strain relaxation process reveals a contribution of the Si(1 1 1) 7 × 7-surface reconstruction to the strain relaxation process. High resolution transmission electron microscopy confirms that the Ge islands exhibit a high degree of structural perfection and an ordered interfacial misfit dislocation network already at a growth temperature of 200 °C is established. The temperature dependency of island shape, density and height is characterized by atomic force microscopy and compared to the RHEED investigations.

  18. Portfolio of qualifications: a tool for evaluating academic productivity at the Karolinska Institutet.

    Science.gov (United States)

    Dahllöf, G; Ekstrand, J; Nordenström, J

    1999-02-01

    A Portfolio of Qualifications for academic appointments at the Karolinska Institutet has been developed to define more clearly the competence and qualifications which are given high priority for academic appointments at the Karolinska Institutet. The major fields of application are for new appointments and promotions, providing guidelines for the individual for improving his/her proficiency, and as a basis for determining individual salary rates. Four portfolios have been developed, a pedagogical, a clinical, a scientific, and a leadership, development and workplace relations portfolio. Attached to the portfolios are assessment forms. We consider the Qualifications Portfolio to be a reflection of changes in attitudes and values at the Karolinska Institutet. The system offers a method for the recognition of faculty productivity in different dimensions. This may be beneficial for the university in view of the increasing diversity and complexity of academic institutions. The Qualifications portfolio can be obtained from the world wide web, http:/(/)www.ki.se/ki/merit.se.html (in Swedish), http:/(/)www.ki.se/ki/merit.html (in English).

  19. The Use of and Reactions to ePortfolio by University Students

    Directory of Open Access Journals (Sweden)

    Lih-Juan ChanLin

    2014-06-01

    Full Text Available Tracking student learning outcomes within college courses is important for observing their academic preparation for future career. Many library and information education institutions are now encouraging the use of ePortfolio system to help students document their school achievements and better present themselves for future job seeking. This study examined the use of and reactions to the ePortforlio system of the Fu Jen Catholic University, launched in Fall, 2010. Qualitative and quantitative data were gathered during 2012 to analyze students’ experiences with and suggestions for the improvement of the ePortfolio system. 66 students’ self-reflections and 12 student interview data were gathered. An online survey based on the previous analyses was then developed and distributed to the LIS students who used the system. A total of 140 responses were gathered and used for quantitative analysis. Results of the study revealed that students’ reactions toward the ePortfolio system were positive. Students perceived the benefits of using ePortfolio in professional development and career placement. Peer influence encouraged the sharing of content. Students also highly agreed that longterm investment of time and use of external incentives were essential for promoting use of the ePortfolio system. It is also suggested that the functions of ePortfolio system needed to be enhanced in order to encourage more students’ use. [Article content in Chinese

  20. An empirical analysis of the risk of crude oil imports in China using improved portfolio approach

    International Nuclear Information System (INIS)

    Wu, Gang; Wei, Yi-Ming; Fan, Ying; Liu, Lan-Cui

    2007-01-01

    This paper quantifies the diversification index of China's crude oil imports during the period 1996-2004, and explores the relationship between the monthly prices and Brent crude oil cash prices. Accordingly, we calculate the systematic and specific risks using portfolio theory of China's crude oil import over the period 1996-2004. Because China's crude oil import increased rapidly since 1996, we improve upon the traditional portfolio theory and develop a risk index model of portfolio theory for crude oil imports in order to explore objectively the changes in China's crude oil import risks. The results show that China's crude oil import risk is affected extensively by the fluctuation of international oil prices. So the traditional portfolio theory is insufficient to measure China's crude oil import risk. The improved portfolio theory risks index model reflects the effect of international oil prices, diversification, imports, and geopolitics factors etc., on crude oil import risk, and changes in crude oil import risk. Therefore, the risk index model of portfolio theory provides greater theoretical and methodological robustness as an indicator of China's crude oil import security than that offered from the application of traditional measures of dependence. (author)

  1. Surface segregation of InGaAs films by the evolution of reflection high-energy electron diffraction patterns

    International Nuclear Information System (INIS)

    Zhou Xun; Luo Zi-Jiang; Guo Xiang; Zhang Bi-Chan; Shang Lin-Tao; Zhou Qing; Deng Chao-Yong; Ding Zhao

    2012-01-01

    Surface segregation is studied via the evolution of reflection high-energy electron diffraction (RHEED) patterns under different values of As 4 BEP for InGaAs films. When the As 4 BEP is set to be zero, the RHEED pattern keeps a 4×3/(n × 3) structure with increasing temperature, and surface segregation takes place until 470 °C. The RHEED pattern develops into a metal-rich (4 × 2) structure as temperature increases to 495 °C. The reason for this is that surface segregation makes the In inside the InGaAs film climb to its surface. With the temperature increasing up to 515 °C, the RHEED pattern turns into a GaAs(2 × 4) structure due to In desorption. While the As 4 BEP comes up to a specific value (1.33 × 10 -4 Pa−1.33 × 10 -3 Pa), the surface temperature can delay the segregation and desorption. We find that As 4 BEP has a big influence on surface desorption, while surface segregation is more strongly dependent on temperature than surface desorption. (condensed matter: structural, mechanical, and thermal properties)

  2. AlGaAs/GaAs two-dimensional electron gas structures studied by photo reflectance spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Guillen Cervantes, A; Rivera Alvarez, Z; Hernandez, F; Huerta, J. [Instituto Politecnico Nacional, Mexico, D.F. (Mexico); Mendez Garcia, V. H.; Lastras Martinez, A.; Zamora, L.; Saucedo, N. [Universidad Autonoma de San Luis Potosi, San Luis Potosi (Mexico); Melendez Lira, M; Lopez, M [Instituto Politecnico Nacional, Mexico, D.F. (Mexico)

    2001-12-01

    Al{sub x} Ga{sub 1}-x As/GaAs two-dimensional electron gas (2-DEG) heterostructures were fabricated by molecular beam epitaxy in three different laboratories. The samples were characterized by room temperature Photo reflectance (PR) spectroscopy and measurements at 77 K. Internal electric fields were detected by the presence of Franz-Keldysh (FK) oscillations in the PR spectra. >From a FK analysis we obtained the GaAs band-gap energy and the built-in electric field strength in each sample. On the other hand, in the energy region corresponding to Al{sub x} Ga{sub 1}-x As a broad PR signal was registered typical of a highly doped material. Using the third derivative theory we obtained the Al{sub x} Ga{sub 1}-x As band-gap energy, and from this value the Al concentration in the samples. Results showed that the sample with highest electron mobility exhibited the lowest internal electric field strength. [Spanish] Se fabricaron heteroestructuras del tipo Al{sub x} Ga{sub 1}-x As/GaAs con un gas de electrones en dos dimensiones por medio de epitaxia de haces moleculares en tres laboratorios diferentes. Las muestras se caracterizaron por fotorreflectancia (FR) a temperatura ambiente y por mediciones del efecto mayor a 77 K. Campos electricos internos se detectaron por la presencia de oscilaciones Franz-Leldysh (FK) en los espectros de FR. Del analisis de las oscilaciones FK obtuvimos la energia de la brecha prohibida del GaAs y la intensidad del campo electrico interno en cada muestra. Por otra parte, en la region de energia correspondiente al Al{sub x} Ga{sub 1}-x As observamos una senal de FR ancha, tipica de un material altamente impurificado. Usando la teoria de la tercera derivada, obtuvimos el valor de la brecha de energia del Al{sub x}Ga{sub 1}-xAs, y de este valor la concentracion de Al en las muestras. Los resultados mostraron que la estructura con el valor de movilidad electronica mas alto tiene la intensidad de campo electrico interno mas baja.

  3. Intermolecular Interactions in Crystalline Theobromine as Reflected in Electron Deformation Density and (13)C NMR Chemical Shift Tensors.

    Science.gov (United States)

    Bouzková, Kateřina; Babinský, Martin; Novosadová, Lucie; Marek, Radek

    2013-06-11

    An understanding of the role of intermolecular interactions in crystal formation is essential to control the generation of diverse crystalline forms which is an important concern for pharmaceutical industry. Very recently, we reported a new approach to interpret the relationships between intermolecular hydrogen bonding, redistribution of electron density in the system, and NMR chemical shifts (Babinský et al. J. Phys. Chem. A, 2013, 117, 497). Here, we employ this approach to characterize a full set of crystal interactions in a sample of anhydrous theobromine as reflected in (13)C NMR chemical shift tensors (CSTs). The important intermolecular contacts are identified by comparing the DFT-calculated NMR CSTs for an isolated theobromine molecule and for clusters composed of several molecules as selected from the available X-ray diffraction data. Furthermore, electron deformation density (EDD) and shielding deformation density (SDD) in the proximity of the nuclei involved in the proposed interactions are calculated and visualized. In addition to the recently reported observations for hydrogen bonding, we focus here particularly on the stacking interactions. Although the principal relations between the EDD and CST for hydrogen bonding (HB) and stacking interactions are similar, the real-space consequences are rather different. Whereas the C-H···X hydrogen bonding influences predominantly and significantly the in-plane principal component of the (13)C CST perpendicular to the HB path and the C═O···H hydrogen bonding modulates both in-plane components of the carbonyl (13)C CST, the stacking modulates the out-of-plane electron density resulting in weak deshielding (2-8 ppm) of both in-plane principal components of the CST and weak shielding (∼ 5 ppm) of the out-of-plane component. The hydrogen-bonding and stacking interactions may add to or subtract from one another to produce total values observed experimentally. On the example of theobromine, we demonstrate

  4. Digital portfolio in building teaching efficacy of pre-service teachers

    Directory of Open Access Journals (Sweden)

    Cimermanová Ivana

    2015-01-01

    Full Text Available The paper discusses the role of e-portfolio in the development of reflective thinking in a group of pre-service English as a foreign language teachers. It stresses the benefits it can bring (e.g. autonomous learning, cooperative learning - the author highlights the social context of e-portfolio as well as presents the threats and risks it might bring based on the own experience of the author. The results of this case study showed that the process of e-portfolio building can enhance professional development, self-confidence and the ability to self-reflect own work and progress. The author indicates also the possibilities of its use not only in the groups of pre-service teacher trainers but also in the groups of in-service teachers.

  5. Can the integration of a PLE in an e-portfolio platform improve generic competences?

    Directory of Open Access Journals (Sweden)

    Cristina Galván-Fernández

    2017-07-01

    Full Text Available The study analyzes the improvement in generic competences through e-portfolio/PLE platform and didactic planning. The new version of the platform, Digital Folder, contains utilities for students and teachers and some PLE components that help the learning process through e-portfolios. Didactic planning is compared for students from the University of Vic and the University of Barcelona, with a total of 61 participants. A questionnaire has been applied for measuring the use of functions and how much these functions aid in the improvement of the generic competences (reflection, planning and selection of information. The results confirm that the most helpful functions for students are: the Schedule, the Academic tasks, the Teacher’s portfolio and Dialogue with the teacher. However, the implication of these functions in the improvement of the competences depends on didactic planning overall for reflection on learning.

  6. The use of portfolios for continuing assessment of physiotherapy students in clinical practice settings

    Directory of Open Access Journals (Sweden)

    N. Naidoo

    2004-01-01

    Full Text Available Many and varied methods of assessment are used to evaluate undergraduate physiotherapy students. Different modes of assessment occur as a result of contrasting educational theories and because the purpose of assessment is variable. In this era of performance assessment related to  the students’ mastery of the core curriculum, portfolios can enhance the assessment process by revealing a range of skills and understandings. This fits snugly into the physiotherapy curriculum for undergraduate continuous assessment purposes. Portfolio assessment can facilitate more reflection on students’ learning, more ownership of learning and more awareness of self-development. This supports the South African Qualifications Authority’s objective for higher education of reflection and life-long learning in our students. This article presents discussion on the use of portfolios in physiotherapy student learning and assessment in clinical practice.

  7. The portfolio method as management support for patients with major depression.

    Science.gov (United States)

    Nunstedt, Håkan; Nilsson, Kerstin; Skärsäter, Ingela

    2014-06-01

    To describe how patients with major depression in psychiatric outpatient care use the portfolio method and whether the method helps the patients to understand their depression. Major depressive disorder is an increasing problem in society. Learning about one's depression has been demonstrated to be important for recovery. If the goal is better understanding and management of depression, learning must proceed on the patient's own terms, based on the patient's previous understanding of their depression. Learning must be aligned with patient needs if it is to result in meaningful and useful understanding. Each patient's portfolio consisted of a binder. Inside the binder, there was a register with predetermined flaps and questions. The patients were asked to work with the questions in the sections that built the content in the portfolio. Individual interviews with patients (n = 5) suffering from major depression according to Diagnostic and Statistical Manual of Mental Disorders - Fourth Edition (DSM-IV) (American Psychiatric Association 1994) were repeatedly conducted between April 2008 and August 2009 in two psychiatric outpatient clinics in western Sweden. Data were analysed using latent content analysis. The results showed that the portfolio was used by patients as a management strategy for processing and analysis of their situation and that a portfolio's structure affects its usability. The patients use the portfolio for reflection on and confirmation of their progress, to create structure in their situation, as a management strategy for remembering situations and providing reminders of upcoming activities. Using a clearly structured care portfolio can enable participation and patient learning and help patients understand their depression. The portfolio method could provide a tool in psychiatric nursing that may facilitate patient understanding and increase self-efficacy. © 2013 John Wiley & Sons Ltd.

  8. The Effect of Self Reflections through Electronic Journals (E-Journals) on the Self Efficacy of Pre-Service Teachers

    Science.gov (United States)

    Tavýl, Zekiye Müge

    2014-01-01

    This study aims both to provide information about the self-reflections of pre-service teachers keeping self-reflective e-journals during the practicum period and to determine the relationship between their self-reflection and self-efficacy levels. Both quantitative and qualitative data were analysed in integration to gain deeper insight into the…

  9. Academic portfolio in the digital era: organizing and maintaining a portfolio using reference managers.

    Science.gov (United States)

    Bhargava, Puneet; Patel, Vatsal B; Iyer, Ramesh S; Moshiri, Mariam; Robinson, Tracy J; Lall, Chandana; Heller, Matthew T

    2015-02-01

    The academic portfolio has become an integral part of the promotions process. Creating and maintaining an academic portfolio in paper-based or web-based formats can be a cumbersome and time-consuming task. In this article, we describe an alternative way to efficiently organize an academic portfolio using a reference manager software, and discuss some of the afforded advantages. The reference manager software Papers (Mekentosj, Amsterdam, The Netherlands) was used to create an academic portfolio. The article outlines the key steps in creating and maintaining a digital academic portfolio. Using reference manager software (Papers), we created an academic portfolio that allows the user to digitally organize clinical, teaching, and research accomplishments in an indexed library enabling efficient updating, rapid retrieval, and easy sharing. To our knowledge, this is the first digital portfolio of its kind.

  10. Model Risk in Portfolio Optimization

    Directory of Open Access Journals (Sweden)

    David Stefanovits

    2014-08-01

    Full Text Available We consider a one-period portfolio optimization problem under model uncertainty. For this purpose, we introduce a measure of model risk. We derive analytical results for this measure of model risk in the mean-variance problem assuming we have observations drawn from a normal variance mixture model. This model allows for heavy tails, tail dependence and leptokurtosis of marginals. The results show that mean-variance optimization is seriously compromised by model uncertainty, in particular, for non-Gaussian data and small sample sizes. To mitigate these shortcomings, we propose a method to adjust the sample covariance matrix in order to reduce model risk.

  11. Portfolio Manager Selection – A Case Study

    DEFF Research Database (Denmark)

    Christensen, Michael

    2017-01-01

    Within a delegated portfolio management setting, this paper presents a case study of how the manager selection process can be operationalized in practice. Investors have to pursue a thorough screening of potential portfolio managers in order to discover their quality, and this paper discusses how...

  12. Purchasing portfolio models: a critique and update

    NARCIS (Netherlands)

    Gelderman, C.J.; Weele, van A.J.

    2005-01-01

    Purchasing portfolio models have spawned considerable discussion in the literature. Many advantages and disadvantages have been put forward, revealing considerable divergence in opinion on the merits of portfolio models. This study addresses the question of whether or not the use of purchasing

  13. Robust portfolio selection under norm uncertainty

    Directory of Open Access Journals (Sweden)

    Lei Wang

    2016-06-01

    Full Text Available Abstract In this paper, we consider the robust portfolio selection problem which has a data uncertainty described by the ( p , w $(p,w$ -norm in the objective function. We show that the robust formulation of this problem is equivalent to a linear optimization problem. Moreover, we present some numerical results concerning our robust portfolio selection problem.

  14. Managing R&D Alliance Portfolios

    DEFF Research Database (Denmark)

    Engel Nielsen, Lars; Mahnke, Volker

    2003-01-01

    be observed in several companies engaged in the cross section of telecommunication and mobile technology where increased complexity magnifies managerial challenges. Drawing on modern portfolio theory, this paper offers a model for managing portfolios of R&D alliances. In particular, an analysis...

  15. Essays on intertemporal consumption and portfolio choice

    NARCIS (Netherlands)

    van Bilsen, Servaas

    2015-01-01

    This dissertation consists of two parts, preceded by an introductory chapter. Part I (Chapters 2, 3 and 4) considers optimal consumption and portfolio choice using preference models. Chapter 2 analyzes optimal consumption and portfolio choice under loss aversion and endogenous updating of the

  16. Portfolios for Majors in Professional Communication.

    Science.gov (United States)

    Killingsworth, M. Jimmie; Sanders, Scott P.

    1987-01-01

    Suggests general principles for developing assignments where students prepare portfolios that reveal their overall communication skills in addition to the usual job search tools. Emphasizes that students should concentrate on including works in the portfolio with the criteria of quality, variety, professionalism, and maturity in mind. (SKC)

  17. IT Portfolio Selection and IT Synergy

    Science.gov (United States)

    Cho, Woo Je

    2010-01-01

    This dissertation consists of three chapters. The primary objectives of this dissertation are: (1) to provide a methodological framework of IT (Information Technology) portfolio management, and (2) to identify the effect of IT synergy on IT portfolio selection of a firm. The first chapter presents a methodological framework for IT project…

  18. Capstone Portfolios and Geography Student Learning Outcomes

    Science.gov (United States)

    Mossa, Joann

    2014-01-01

    Due to increasing demands regarding student learning outcomes and accreditation, a capstone portfolio was added to assess critical thinking and communication skills of geography majors at a large public university in the USA. The portfolio guidelines were designed to be adaptable to a flexible curriculum where about half of the requirements within…

  19. Predictors and Portfolios Over the Life Cycle

    DEFF Research Database (Denmark)

    Kraft, Holger; Munk, Claus; Weiss, Farina

    In a calibrated consumption-portfolio model with stock, housing, and labor income predictability, we evaluate the welfare effects of predictability on life-cycle consumption-portfolio choice. We compare skilled investors who are able to take advantage of all sources of predictability with unskilled...

  20. Optimal Portfolio Choice with Wash Sale Constraints

    DEFF Research Database (Denmark)

    Astrup Jensen, Bjarne; Marekwica, Marcel

    2011-01-01

    We analytically solve the portfolio choice problem in the presence of wash sale constraints in a two-period model with one risky asset. Our results show that wash sale constraints can heavily affect portfolio choice of investors with unrealized losses. The trading behavior of such investors...

  1. On the Teaching of Portfolio Theory.

    Science.gov (United States)

    Biederman, Daniel K.

    1992-01-01

    Demonstrates how a simple portfolio problem expressed explicitly as an expected utility maximization problem can be used to instruct students in portfolio theory. Discusses risk aversion, decision making under uncertainty, and the limitations of the traditional mean variance approach. Suggests students may develop a greater appreciation of general…

  2. The Use of Portfolios in Leadership Education

    Science.gov (United States)

    Olsen, Paul E.

    2009-01-01

    This paper discusses the benefits of using student portfolios in undergraduate leadership education at Saint Michael's College. There appears to be a natural link between the use of portfolios as a tool to facilitate and document leadership growth and development. The Business Administration and Accounting Department at Saint Michael's College…

  3. Optimal portfolio choice under loss aversion

    NARCIS (Netherlands)

    A.B. Berkelaar (Arjan); R.R.P. Kouwenberg (Roy)

    2000-01-01

    textabstractProspect theory and loss aversion play a dominant role in behavioral finance. In this paper we derive closed-form solutions for optimal portfolio choice under loss aversion. When confronted with gains a loss averse investor behaves similar to a portfolio insurer. When confronted with

  4. Optimization of the bank's operating portfolio

    Science.gov (United States)

    Borodachev, S. M.; Medvedev, M. A.

    2016-06-01

    The theory of efficient portfolios developed by Markowitz is used to optimize the structure of the types of financial operations of a bank (bank portfolio) in order to increase the profit and reduce the risk. The focus of this paper is to check the stability of the model to errors in the original data.

  5. SunShot Initiative Portfolio Book 2014

    Energy Technology Data Exchange (ETDEWEB)

    Solar Energy Technologies Office

    2014-05-01

    The 2014 SunShot Initiative Portfolio Book outlines the progress towards the goals outlined in the SunShot Vision Study. Contents include overviews of each of SunShot’s five subprogram areas, as well as a description of every active project in the SunShot’s project portfolio as of May 2014.

  6. Portfolio Diversification Effects of Downside Risk

    NARCIS (Netherlands)

    N. Hyung (Namwon); C.G. de Vries (Casper)

    2004-01-01

    textabstractRisk managers use portfolios to diversify away the un-priced risk of individual securities. In this paper we compare the benefits of portfolio diversification for downside risk in case returns are normally distributed with the case fat tailed distributed returns. The downside risk of a

  7. The Shapley decomposition for portfolio risk

    OpenAIRE

    Stéphane Mussard; Virginie Terraza

    2006-01-01

    The aim of this paper is to provide an application of the Shapley Value to decompose financial portfolio risk. Decomposing the sample covariance risk measure yields relative measures, which enable securities of a portfolio to be classified according to risk scales.

  8. Portfolio Assessment: Production and Reduction of Complexity

    DEFF Research Database (Denmark)

    Keiding, Tina Bering; Qvortrup, Ane

    2015-01-01

    Over the last two decades, the education system has witnessed a shift from summative, product-oriented assessment towards formative, process-oriented assessment. Among the different learning and assessment initiatives introduced in the slipstream of this paradigmatic turn, the portfolio seems...... to have become one of the most popular. By re-describing the portfolio from a systems theoretical point of view, this article discusses established expectations of the portfolio in relation to transparency in learning, reflexivity and self-assessment. It shows that the majority of the literature deals...... with what-questions and that the portfolio is expected to handle a number of challenges with regard to the documentation of learning processes and achievements as well as the conditioning of learning activities. Furthermore, is becomes clear that descriptions of how the portfolio works are sparse. Based...

  9. Student evaluations of the portfolio process.

    Science.gov (United States)

    Murphy, John E; Airey, Tatum C; Bisso, Andrea M; Slack, Marion K

    2011-09-10

    To evaluate pharmacy students' perceived benefits of the portfolio process and to gather suggestions for improving the process. A questionnaire was designed and administered to 250 first-, second-, and third-year pharmacy students at the University of Arizona College of Pharmacy. Although the objectives of the portfolio process were for students to understand the expected outcomes, understand the impact of extracurricular activities on attaining competencies, identify what should be learned, identify their strengths and weaknesses, and modify their approach to learning, overall students perceived the portfolio process as having less than moderate benefit. First-year students wanted more examples of portfolios while second- and third-year students suggested that more time with their advisor would be beneficial. The portfolio process will continue to be refined and efforts made to improve students' perceptions of the process as it is intended to develop the self-assessments skills they will need to improve their knowledge and professional skills throughout their pharmacy careers.

  10. MODEL OF DISTRIBUTION OF THE BUDGET OF THE PORTFOLIO OF IT PROJECTS TAKING IN-TO ACCOUNT THEIR PRIORITY

    Directory of Open Access Journals (Sweden)

    Anita V. Sotnikova

    2015-01-01

    Full Text Available Article is devoted to a problem of effective distribution of the general budget of a portfolio between the IT projects which are its part taking into ac-count their priority. The designated problem is actual in view of low results of activity of the consulting companies in the sphere of information technologies.For determination of priority of IT projects the method of analytical networks developed by T. Saati is used. For the purpose of application of this method the system of criteria (indicators reflecting influence of IT projects of a portfolio on the most significant purposes of implementation of IT projects of a portfolio is developed. As system of criteria the key indicators of efficiency defined when developing the Balanced system of indicators which meet above-mentioned requirements are used. The essence of a method of analytical net-works consists in paired comparison of key indicators of efficiency concerning the purpose of realization of a portfolio and IT projects which are a part of a portfolio. Result of use of a method of analytical networks are coefficients of priority of each IT project of a portfolio. The received coefficients of priority of IT projects are used in the offered model of distribution of the budget of a portfolio between IT projects. Thus, the budget of a portfolio of IT projects is distributed between them taking into account not only the income from implementation of each IT project, but also other criteria, important for the IT company, for example: the degree of compliance of the IT project to strategic objectives of the IT company defining expediency of implementation of the IT project; the term of implementation of the IT project determined by the customer. The developed model of distribution of the budget of a portfolio between IT projects is approved on the example of distribution of the budget between IT projects of the portfolio consisting of three IT projects. Taking into account the received

  11. Feedback using an ePortfolio for medicine long cases: quality not quantity

    Directory of Open Access Journals (Sweden)

    Jane Bleasel

    2016-10-01

    Full Text Available Abstract Background The evidence for the positive impact of an electronic Portfolio (ePortfolio on feedback in medicine is mixed. An ePortfolio for medical long cases in a Graduate Medical Program was developed. The purpose of this study was to explore the perceptions of medical students and faculty of the impact of the ePortfolio on the feedback process. Methods In total, 130 Year 3 medical students, and six faculty participated in the study. This is a mixed methods study, using a combination of both quantitative and qualitative approaches. Quantitative methods were used to quantify the number of long cases performed. Qualitative methods were used to explore the relationship between quantity and quality of feedback, and provide a rich understanding of both students’ and faculty’s experience and perceptions of the ePortfolio. Results Students received a variable quantity of feedback at each of the three studied clinical schools, with an average of between 4 – 5.4 feedback episodes per student. Feedback that was constructive, specific and timely and delivered by a senior academic was important. Quantity was not an essential factor, with two episodes of detailed feedback reported to be adequate. The barriers to the use of the ePortfolio were technical aspects of the platform that interfered with student engagement. Conclusions Feedback using the ePortfolio for medical long cases is a valuable tool providing a senior clinician delivers detailed, constructive and personalized feedback in a timely fashion. The ePortfolio system needs to be user-friendly to engage students.

  12. Portfolio Optimization and Mortgage Choice

    Directory of Open Access Journals (Sweden)

    Maj-Britt Nordfang

    2017-01-01

    Full Text Available This paper studies the optimal mortgage choice of an investor in a simple bond market with a stochastic interest rate and access to term life insurance. The study is based on advances in stochastic control theory, which provides analytical solutions to portfolio problems with a stochastic interest rate. We derive the optimal portfolio of a mortgagor in a simple framework and formulate stylized versions of mortgage products offered in the market today. This allows us to analyze the optimal investment strategy in terms of optimal mortgage choice. We conclude that certain extreme investors optimally choose either a traditional fixed rate mortgage or an adjustable rate mortgage, while investors with moderate risk aversion and income prefer a mix of the two. By matching specific investor characteristics to existing mortgage products, our study provides a better understanding of the complex and yet restricted mortgage choice faced by many household investors. In addition, the simple analytical framework enables a detailed analysis of how changes to market, income and preference parameters affect the optimal mortgage choice.

  13. Improving the Automatic Inversion of Digital Alouette/ISIS Ionogram Reflection Traces into Topside Electron Density Profiles

    Science.gov (United States)

    Benson, Robert F.; Truhlik, Vladimir; Huang, Xueqin; Wang, Yongli; Bilitza, Dieter

    2012-01-01

    The topside sounders of the International Satellites for Ionospheric Studies (ISIS) program were designed as analog systems. The resulting ionograms were displayed on 35 mm film for analysis by visual inspection. Each of these satellites, launched between 1962 and 1971, produced data for 10 to 20 years. A number of the original telemetry tapes from this large data set have been converted directly into digital records. Software, known as the Topside Ionogram Scalar With True-Height (TOPIST) algorithm, has been produced and used for the automatic inversion of the ionogram reflection traces on more than 100,000 ISIS-2 digital topside ionograms into topside vertical electron density profiles Ne(h). Here we present some topside ionospheric solar cycle variations deduced from the TOPIST database to illustrate the scientific benefit of improving and expanding the topside ionospheric Ne(h) database. The profile improvements will be based on improvements in the TOPIST software motivated by direct comparisons between TOPIST profiles and profiles produced by manual scaling in the early days of the ISIS program. The database expansion will be based on new software designed to overcome limitations in the original digital topside ionogram database caused by difficulties encountered during the analog-to-digital conversion process in the detection of the ionogram frame sync pulse and/or the frequency markers. This improved and expanded TOPIST topside Ne(h) database will greatly enhance investigations into both short- and long-term ionospheric changes, e.g., the observed topside ionospheric responses to magnetic storms, induced by interplanetary magnetic clouds, and solar cycle variations, respectively.

  14. Atomistic simulation of femtosecond laser pulse interactions with a copper film: Effect of dependency of penetration depth and reflectivity on electron temperature

    Science.gov (United States)

    Amouye Foumani, A.; Niknam, A. R.

    2018-01-01

    The response of copper films to irradiation with laser pulses of fluences in the range of 100-6000 J/m2 is simulated by using a modified combination of a two-temperature model (TTM) and molecular dynamics (MD). In this model, the dependency of the pulse penetration depth and the reflectivity of the target on electron temperature are taken into account. Also, the temperature-dependent electron-phonon coupling factor, electron thermal conductivity, and electron heat capacity are used in the simulations. Based on this model, the dependence of the integral reflectivity on pulse fluence, the changes in the film thickness, and the evolution of density and electron and lattice temperatures are obtained. Moreover, snapshots that show the melting and disintegration processes are presented. The disintegration starts at a fluence of 4200 J/m2, which corresponds with an absorbed fluence of 616 J/m2. The calculated values of integral reflectivity are in good agreement with the experimental data. The inclusion of such temperature-dependent absorption models in the TTM-MD method would facilitate the comparison of experimental data with simulation results.

  15. The national portfolio for postgraduate family medicine training in South Africa: a descriptive study of acceptability, educational impact, and usefulness for assessment.

    Science.gov (United States)

    Jenkins, Louis; Mash, Bob; Derese, Anselme

    2013-07-25

    Since 2007 a portfolio of learning has become a requirement for assessment of postgraduate family medicine training by the Colleges of Medicine of South Africa. A uniform portfolio of learning has been developed and content validity established among the eight postgraduate programmes. The aim of this study was to investigate the portfolio's acceptability, educational impact, and perceived usefulness for assessment of competence. Two structured questionnaires of 35 closed and open-ended questions were delivered to 53 family physician supervisors and 48 registrars who had used the portfolio. Categorical and nominal/ordinal data were analysed using simple descriptive statistics. The open-ended questions were analysed with ATLAS.ti software. Half of registrars did not find the portfolio clear, practical or feasible. Workshops on portfolio use, learning, and supervision were supported, and brief dedicated time daily for reflection and writing. Most supervisors felt the portfolio reflected an accurate picture of learning, but just over half of registrars agreed. While the portfolio helped with reflection on learning, participants were less convinced about how it helped them plan further learning. Supervisors graded most rotations, suggesting understanding the summative aspect, while only 61% of registrars reflected on rotations, suggesting the formative aspects are not yet optimally utilised. Poor feedback, the need for protected academic time, and pressure of service delivery impacting negatively on learning. This first introduction of a national portfolio for postgraduate training in family medicine in South Africa faces challenges similar to those in other countries. Acceptability of the portfolio relates to a clear purpose and guide, flexible format with tools available in the workplace, and appreciating the changing educational environment from university-based to national assessments. The role of the supervisor in direct observations of the registrar and dedicated

  16. Incorporating a Soil Science Artifact into a University ePortfolio Assessment Tool

    Science.gov (United States)

    Mikhailova, Elena; Werts, Joshua; Post, Christopher; Ring, Gail

    2014-01-01

    The ePortfolio is a useful educational tool that is utilized in many educational institutions to showcase student accomplishments and provide students with an opportunity to reflect on their educational progress. The objective of this study was to develop and test an artifact from an introductory soil science course to be included in the…

  17. Assistant professor wins grant to help enrich graduate student careers with e-portfolios

    OpenAIRE

    Mackay, Steven D.

    2010-01-01

    Lisa McNair, an assistant professor with the department of engineering education, has won a $403,000 National Science Foundation Faculty Early Career Development (CAREER) grant to help engineering graduate students develop as reflective practitioners by using e-portfolios that could enrich their own careers.

  18. Conceptualizing the Functional Requirements for a Next-Generation E-Portfolio System

    Science.gov (United States)

    Mu, Enrique; Wormer, Sallie; Foizey, Roberta; Barkon, Beverly; Vehec, Mark

    2010-01-01

    The use of e-portfolio systems in higher education has not grown as anticipated by early adopters when the potential benefits first became apparent, yet the promise remains. The vision of a flexible tool that meets multiple goals--serving as a showcase for student work, promoting self-reflection, supporting assessment and accreditation efforts,…

  19. PRODUCT PORTFOLIO ANALYSIS - ARTHUR D. LITTLE MATRIX

    Directory of Open Access Journals (Sweden)

    Curmei Catalin Valeriu

    2011-07-01

    Full Text Available In recent decades we have witnessed an unseen dynamism among companies, which is explained by their desire to engage in more activities that provide a high level of development and diversification. Thus, as companies are diversifying more and more, their managers confront a number of challenges arising from the management of resources for the product portfolio and the low level of resources with which companies can identify, at a time. Responding to these challenges, over time were developed a series of analytical product portfolio methods through which managers can balance the sources of cash flows from the multiple products and also can identify the place and role of products, in strategic terms, within the product portfolio. In order to identify these methods the authors of the present paper have conducted a desk research in order to analyze the strategic marketing and management literature of the last 2 decades. Widely were studied a series of methods that are presented in the marketing and management literature as the main instruments used within the product portfolio strategic planning process. Among these methods we focused on the Arthur D. Little matrix. Thus the present paper has the purpose to outline the characteristics and strategic implications of the ADL matrix within a company’s product portfolio. After conducting this analysis we have found that restricting the product portfolio analysis to the A.D.L. matrix is not a very wise decision. The A.D.L. matrix among with other marketing tools of product portfolio analysis have some advantages and disadvantages and is trying to provide, at a time, a specific diagnosis of a company’s product portfolio. Therefore, the recommendation for the Romanian managers consists in a combined use of a wide range of tools and techniques for product portfolio analysis. This leads to a better understanding of the whole mix of product markets, included in portfolio analysis, the strategic position

  20. Factors Influencing Acceptability and Perceived Impacts of a Mandatory ePortfolio Implemented by an Occupational Therapy Regulatory Organization.

    Science.gov (United States)

    Vachon, Brigitte; Foucault, Marie-Lyse; Giguère, Charles-Édouard; Rochette, Annie; Thomas, Aliki; Morel, Martine

    2018-01-01

    The use of ePortfolios has been implemented in several regulatory organizations to encourage clinicians' engagement in continuing professional development (CPD). However, their use has achieved mixed success, and multiple personal and contextual factors can influence their impacts on practice change. The aim of this study was to identify which factors influence the acceptability and perceived impacts of an ePortfolio implemented by an occupational therapy regulatory organization in one Canadian province. A cross-sectional online survey design was used. The survey was sent to registered occupational therapists in Quebec. Multiple regression analyses were conducted to identify factors influencing acceptability and outcomes: ease of use, satisfaction, impact on implementation of the CPD plan, and competence improvement. The survey was fully completed by 546 participants. Factors significantly influencing the ePortfolio acceptability and perceived impacts were attitude toward and familiarity with the portfolio, confidence in reflective skills, engagement in the CPD plan, and desire for feedback. Time spent completing the ePortfolio and the fact of completing it in teams were negatively associated with the outcomes. Shaping more favorable user attitudes, helping users recognize and experience the tool's benefits for their practice, and fostering confidence in their reflective skills are important factors that can be addressed to improve ePortfolio acceptability and outcomes. Contextual factors, such as time spent completing the ePortfolio and completing it in teams, seem to reflect greater difficulty with using the tool. Study findings can contribute to improving ePortfolio implementation in the CPD context.

  1. Patent portfolio management: literature review and a proposed model.

    Science.gov (United States)

    Conegundes De Jesus, Camila Kiyomi; Salerno, Mario Sergio

    2018-05-09

    Patents and patent portfolios are gaining attention in the last decades, from the called 'pro-patent era' to the recent billionaire transactions involving patent portfolios. The field is growing in importance, both theoretically and practically and despite having substantial literature on new product development portfolio management, we have not found an article relating this theory to patent portfolios. Areas covered: The paper develops a systematic literature review on patent portfolio management to organize the evolution and tendencies of patent portfolio management, highlighting distinctive features of patent portfolio management. Interview with IP manager of three life sciences companies, including a leading multinational group provided relevant information about patent portfolio management. Expert opinion: Based on the systematic literature review on portfolio management, more specifically, on new product development portfolio theory, and interview the paper proposes the paper proposes a reference model to manage patent portfolios. The model comprises four stages aligned with the three goals of the NPD portfolio management: 1 - Linking strategy of the Company's NPD Portfolio to Patent Portfolio; 2 - Balancing the portfolio in buckets; 3 - Patent Valuation (maximizing valuation); 4 - Regularly reviewing the patent portfolio.

  2. 12 CFR 1252.1 - Enterprise portfolio holding criteria.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 7 2010-01-01 2010-01-01 false Enterprise portfolio holding criteria. 1252.1 Section 1252.1 Banks and Banking FEDERAL HOUSING FINANCE AGENCY ENTERPRISES PORTFOLIO HOLDINGS § 1252.1 Enterprise portfolio holding criteria. The Enterprises are required to comply with the portfolio holdings...

  3. Portfolio Assessment: A Handbook for Educators. Assessment Bookshelf Series.

    Science.gov (United States)

    Barton, James, Ed.; Collins, Angelo, Ed.

    This guide contains practical steps for integrating portfolios into any K-12 classroom and tips for effective classroom management of portfolios. It also contains actual examples of portfolios in action in a variety of subject areas. The chapters are: (1) "Starting Out: Designing Your Portfolio" (James Barton and Angelo Collins); (2) "Preparing…

  4. The Finite and Moving Order Multinomial Universal Portfolio

    International Nuclear Information System (INIS)

    Tan, Choon Peng; Pang, Sook Theng

    2013-01-01

    An upper bound for the ratio of wealths of the best constant -rebalanced portfolio to that of the multinomial universal portfolio is derived. The finite- order multinomial universal portfolios can reduce the implementation time and computer-memory requirements for computation. The improved performance of the finite-order portfolios on some selected local stock-price data sets is observed.

  5. Formation of a conducting LaAlO3/SrTiO3 interface studied by low-energy electron reflection during growth

    Science.gov (United States)

    van der Torren, A. J. H.; Liao, Z.; Xu, C.; Gauquelin, N.; Yin, C.; Aarts, J.; van der Molen, S. J.

    2017-12-01

    The two-dimensional electron gas occurring between the band insulators SrTiO3 and LaAlO3 continues to attract considerable interest, due to the possibility of dynamic control over the carrier density and due to ensuing phenomena such as magnetism and superconductivity. The formation of this conducting interface is sensitive to the growth conditions, but despite numerous investigations there are still questions about the details of the physics involved. In particular, not much is known about the electronic structure of the growing LaAlO3 layer at the growth temperature (around 800°C) in oxygen (pressure around 5 ×10-5 mbar), since analysis techniques at these conditions are not readily available. We developed a pulsed laser deposition system inside a low-energy electron microscope in order to study this issue. The setup allows for layer-by-layer growth control and in situ measurements of the angle-dependent electron reflection intensity, which can be used as a fingerprint of the electronic structure of the surface layers during growth. By using different substrate terminations and growth conditions we observe two families of reflectivity maps, which we can connect either to samples with an AlO2-rich surface and a conducting interface or to samples with a LaO-rich surface and an insulating interface. Our observations emphasize that substrate termination and stoichiometry determine the electronic structure of the growing layer, and thereby the conductance of the interface.

  6. Design and implementation of an optimal laser pulse front tilting scheme for ultrafast electron diffraction in reflection geometry with high temporal resolution

    Directory of Open Access Journals (Sweden)

    Francesco Pennacchio

    2017-07-01

    Full Text Available Ultrafast electron diffraction is a powerful technique to investigate out-of-equilibrium atomic dynamics in solids with high temporal resolution. When diffraction is performed in reflection geometry, the main limitation is the mismatch in group velocity between the overlapping pump light and the electron probe pulses, which affects the overall temporal resolution of the experiment. A solution already available in the literature involved pulse front tilt of the pump beam at the sample, providing a sub-picosecond time resolution. However, in the reported optical scheme, the tilted pulse is characterized by a temporal chirp of about 1 ps at 1 mm away from the centre of the beam, which limits the investigation of surface dynamics in large crystals. In this paper, we propose an optimal tilting scheme designed for a radio-frequency-compressed ultrafast electron diffraction setup working in reflection geometry with 30 keV electron pulses containing up to 105 electrons/pulse. To characterize our scheme, we performed optical cross-correlation measurements, obtaining an average temporal width of the tilted pulse lower than 250 fs. The calibration of the electron-laser temporal overlap was obtained by monitoring the spatial profile of the electron beam when interacting with the plasma optically induced at the apex of a copper needle (plasma lensing effect. Finally, we report the first time-resolved results obtained on graphite, where the electron-phonon coupling dynamics is observed, showing an overall temporal resolution in the sub-500 fs regime. The successful implementation of this configuration opens the way to directly probe structural dynamics of low-dimensional systems in the sub-picosecond regime, with pulsed electrons.

  7. METHODICAL BASES OF MANAGEMENT OF INSURANCE PORTFOLIO

    Directory of Open Access Journals (Sweden)

    Serdechna Yulia

    2018-01-01

    Full Text Available Introduction. Despite the considerable arsenal of developments in the issues of assessing the management of the insurance portfolio remains unresolved. In order to detail, specify and further systematize the indicators for the indicated evaluation, the publications of scientists are analyzed. The purpose of the study is to analyze existing methods by which it is possible to formulate and manage the insurance portfolio in order to achieve its balance, which will contribute to ensuring the financial reliability of the insurance company. Results. The description of the essence of the concept of “management of insurance portfolio”, as the application of actuarial methods and techniques to the combination of various insurance risks offered for insurance or are already part of the insurance portfolio, allowing to adjust the size and structure of the portfolio in order to ensure its financial stability, achievement the maximum level of income of an insurance organization, preservation of the value of its equity and financial security of insurance liabilities. It is determined that the main methods by which the insurer’s insurance portfolio can be formed and managed is the selection of risks; reinsurance operations that ensure diversification of risks; formation and placement of insurance reserves, which form the financial basis of insurance activities. The method of managing an insurance portfolio, which can be both active and passive, is considered. Conclusions. It is determined that the insurance portfolio is the basis on which all the activities of the insurer are based and which determines its financial stability. The combination of methods and technologies applied to the insurance portfolio is a management method that can be both active and passive and has a number of specific methods through which the insurer’s insurance portfolio can be formed and managed. It is substantiated that each insurance company aims to form an efficient and

  8. Portfolio analysis of layered security measures.

    Science.gov (United States)

    Chatterjee, Samrat; Hora, Stephen C; Rosoff, Heather

    2015-03-01

    Layered defenses are necessary for protecting the public from terrorist attacks. Designing a system of such defensive measures requires consideration of the interaction of these countermeasures. In this article, we present an analysis of a layered security system within the lower Manhattan area. It shows how portfolios of security measures can be evaluated through portfolio decision analysis. Consideration is given to the total benefits and costs of the system. Portfolio diagrams are created that help communicate alternatives among stakeholders who have differing views on the tradeoffs between security and economic activity. © 2014 Society for Risk Analysis.

  9. Does asymmetric correlation affect portfolio optimization?

    Science.gov (United States)

    Fryd, Lukas

    2017-07-01

    The classical portfolio optimization problem does not assume asymmetric behavior of relationship among asset returns. The existence of asymmetric response in correlation on the bad news could be important information in portfolio optimization. The paper applies Dynamic conditional correlation model (DCC) and his asymmetric version (ADCC) to propose asymmetric behavior of conditional correlation. We analyse asymmetric correlation among S&P index, bonds index and spot gold price before mortgage crisis in 2008. We evaluate forecast ability of the models during and after mortgage crisis and demonstrate the impact of asymmetric correlation on the reduction of portfolio variance.

  10. Real Time Investments with Adequate Portfolio Theory

    Directory of Open Access Journals (Sweden)

    Alina Kvietkauskienė

    2015-02-01

    Full Text Available The objective of this paper is to identify investment decision makingschemes using the adequate portfolio model. This approach can be employed to project investment in stocks, using the opportunities offered by the markets and investor intelligence. It was decided to use adequate portfolio theory for investment decision making, simulation of financial markets, and optimisation of utility function. The main conclusion of article suggests investigating return on individual portfolio level. Real investment is a way to make sure of the soundness of applicable strategies.

  11. Technology Audit: Assessment of Innovative Portfolio

    Directory of Open Access Journals (Sweden)

    Kurushina Viktoria

    2016-01-01

    Full Text Available The article discusses the features of the technological audit performing in the companies of oil and gas sector of Russian economy. To measure the innovations quality level the scale was developed based on the Theory of Inventive Problem Solving and the theory of technological structures. Figures of the innovations quantity by levels, volume and quality of the innovative portfolio are offered for assessment the innovative portfolio quality. The method was tested on an example of oil and gas transporting enterprises. The results of the comparative analysis of innovative portfolio are shown.

  12. Probing ultrafast changes of spin and charge density profiles with resonant XUV magnetic reflectivity at the free-electron laser FERMI.

    Science.gov (United States)

    Gutt, C; Sant, T; Ksenzov, D; Capotondi, F; Pedersoli, E; Raimondi, L; Nikolov, I P; Kiskinova, M; Jaiswal, S; Jakob, G; Kläui, M; Zabel, H; Pietsch, U

    2017-09-01

    We report the results of resonant magnetic XUV reflectivity experiments performed at the XUV free-electron laser FERMI. Circularly polarized XUV light with the photon energy tuned to the Fe M 2,3 edge is used to measure resonant magnetic reflectivities and the corresponding Q -resolved asymmetry of a Permalloy/Ta/Permalloy trilayer film. The asymmetry exhibits ultrafast changes on 240 fs time scales upon pumping with ultrashort IR laser pulses. Depending on the value of the wavevector transfer Q z , we observe both decreasing and increasing values of the asymmetry parameter, which is attributed to ultrafast changes in the vertical spin and charge density profiles of the trilayer film.

  13. Measuring Treasury Bond Portfolio Risk and Portfolio Optimization with a Non-Gaussian Multivariate Model

    Science.gov (United States)

    Dong, Yijun

    The research about measuring the risk of a bond portfolio and the portfolio optimization was relatively rare previously, because the risk factors of bond portfolios are not very volatile. However, this condition has changed recently. The 2008 financial crisis brought high volatility to the risk factors and the related bond securities, even if the highly rated U.S. treasury bonds. Moreover, the risk factors of bond portfolios show properties of fat-tailness and asymmetry like risk factors of equity portfolios. Therefore, we need to use advanced techniques to measure and manage risk of bond portfolios. In our paper, we first apply autoregressive moving average generalized autoregressive conditional heteroscedasticity (ARMA-GARCH) model with multivariate normal tempered stable (MNTS) distribution innovations to predict risk factors of U.S. treasury bonds and statistically demonstrate that MNTS distribution has the ability to capture the properties of risk factors based on the goodness-of-fit tests. Then based on empirical evidence, we find that the VaR and AVaR estimated by assuming normal tempered stable distribution are more realistic and reliable than those estimated by assuming normal distribution, especially for the financial crisis period. Finally, we use the mean-risk portfolio optimization to minimize portfolios' potential risks. The empirical study indicates that the optimized bond portfolios have better risk-adjusted performances than the benchmark portfolios for some periods. Moreover, the optimized bond portfolios obtained by assuming normal tempered stable distribution have improved performances in comparison to the optimized bond portfolios obtained by assuming normal distribution.

  14. The Role of Agribusiness Assets in Investment Portfolios

    OpenAIRE

    Johnson, Michael; Malcolm, Bill; O'Connor, Ian

    2006-01-01

    Investment in agribusiness assets has grown significantly in recent years. The question of interest is whether including agribusiness assets in investment portfolios provide benefits. The effects of diversification by including agribusiness assets in two investment portfolios, a mixed asset portfolio and a diversified share portfolio was investigated using Markowitz’s (1952) Modern Portfolio Theory (MPT) of mean-variance optimization. To measure the performance of agribusiness assets, an in...

  15. An Extensive Evaluation of Portfolio Approaches for Constraint Satisfaction Problems

    Directory of Open Access Journals (Sweden)

    Roberto Amadini

    2016-06-01

    Full Text Available In the context of Constraint Programming, a portfolio approach exploits the complementary strengths of a portfolio of different constraint solvers. The goal is to predict and run the best solver(s of the portfolio for solving a new, unseen problem. In this work we reproduce, simulate, and evaluate the performance of different portfolio approaches on extensive benchmarks of Constraint Satisfaction Problems. Empirical results clearly show the benefits of portfolio solvers in terms of both solved instances and solving time.

  16. [Development and validation of a questionnaire on perception of portfolio by undergraduate medical students].

    Science.gov (United States)

    Riquelme, Arnoldo; Méndez, Benjamín; de la Fuente, Paloma; Padilla, Oslando; Benaglio, Carla; Sirhan, Marisol; Labarca, Jaime

    2011-01-01

    Portfolio is an innovative instrument that promotes reflection, creativity and professionalism among students. To describe the development and validation process of a questionnaire to evaluate the use of portfolio in undergraduate medical students. Focus groups with students and teachers were employed to identify aspects related with portfolio in undergraduate teaching. The Delphi technique was used to prioritize relevant aspects and construct the questionnaire. The validated questionnaire, consisting of 43 items and 6 factors, was applied to 97 students (response rote of 99.9%) in 2007 and 100 students (99.2%) in 2008. Each question had to be answered using a Likert scale, from 0 (completely disagree) to 4 (completely agree) The validity and reliability of the questionnaire was evaluated. The questionnaire showed a high reliability (Cronbach alpha = 0.9). The mean total scores obtained in 2007 and 2008 were 106.2 ± 21.2 (61.7% of the maximal obtainable score) and 104.6 ± 34.0 (60.8% of the maximal obtainable score), respectively No significant differences were seen in the analysis by factors. Changes in portfolio during 2008 showed differences in items related with organization, evaluation and regulation. The questionnaire is a valid and highly reliable instrument, measuring perceptions about the portfolio by undergraduate medical students. The students perceived an improvement in their creativity and professionalism as one of the strengths of portfolio. The weaknesses identified during the implementation process helped us to focus changes in organization and evaluation to improve the portfolio as a dynamic process.

  17. Exploring Students’ Attitudes and Beliefs Towards E-Portfolios and Technology in Education

    Directory of Open Access Journals (Sweden)

    Gemma TUR

    2015-05-01

    Full Text Available This article reports on student teachers’ attitude towards technology in education and e-portfolio processes. Attitude is closely related to teachers’ beliefs and the later have been defined as second-order barriers. While an important effort has been made to overcome first-order barrier such as resources, training and support, it cannot be observed that technology has been successfully introduced in education. Therefore, second-order barriers such as attitudes and beliefs are being considered nowadays in order to address the lack of innovative use of technology by teachers. It has been argued that the introduction of technology has to be directed towards the empowerment of cognitive and high-level thinking skills and has to be used based on student-centred approaches. Building e-portfolios and helping students which grow and curate their own Personal Learning Environments (PLE are two approaches to go beyond technology-centered models. E-Portfolios are viewed as part of students’ PLE so social media are used to enhance both e-portfolio processes and students’ PLEs. The research is based on a survey in four groups of students at the local branch in Ibiza of the University of the Balearic Islands. The participants have previously built their e-portfolios with Web 2.0 tools during one semester. Students are asked to document their learning weekly and reflect on the change experienced in the way they think about educational issues. Students are also asked to use new tools and social media services to give evidence of their own learning. The survey is based on a Likert scale so as to be able to analyse the students’ attitude and beliefs towards their e-portfolio and technology in education. The results show that a generally positive attitude is developed by students. Conclusions highlight the slight difference in student teachers’ attitude between technology and specific e-portfolio processes.

  18. La incorporación de los portafolios electrónicos en el proceso enseñanza-aprendizaje y evaluación de la geografía en el alumnado de educación a distancia = The incorporation of electronic portfolios learning in geography and evaluation process in distance

    Directory of Open Access Journals (Sweden)

    Francisco José Morales Yago

    2016-09-01

    Full Text Available El presente artículo expone el sentido y las características de un portfolio lectrónico aplicado en un contexto universitario de enseñanza a distancia, en la asignatura: «Introducción a la investigación en Espacios Sociales» correspondiente al Máster de la UNED denominado: «Métodos y técnicas avanzadas de investigación histórica, artística y geográfica», dentro del itinerario de Geografía. La plataforma ALF de la UNED será el instrumento de e–Learning que permitirá impartir formación, gestionar y compartir documentos, crear y participar en comunidades temáticas, así como realizar proyectos online. A través de la misma se llevará a cabo todo el intercambio de documentación, aportación de ideas, orientaciones básicas e incluso el seguimiento de los procesos desde el inicio hasta su finalización. This communication presents the meaning and characteristics of an electronic portfolio applied in a university context of distance learning in the course: «Introduction to Research in Social Spaces» for the Master of UNED called: «Methods and advanced techniques historical, artistic and geographical research «within the itinerary of Geography. The ALF platform UNED will be e-Learning tool that will allow train, manage and share documents, create and participate in thematic communities, as well as make online projects. Through the same will take place around the exchange of documentation, brainstorming, basic orientations and even tracking processes from start to finish.

  19. 13 CFR 107.760 - How a change in size or activity of a Portfolio Concern affects the Licensee and the Portfolio...

    Science.gov (United States)

    2010-01-01

    ... of a Portfolio Concern affects the Licensee and the Portfolio Concern. 107.760 Section 107.760... § 107.760 How a change in size or activity of a Portfolio Concern affects the Licensee and the Portfolio Concern. (a) Effect on Licensee of a change in size of a Portfolio Concern. If a Portfolio Concern no...

  20. How we developed a role-based portfolio for teachers' professional development.

    Science.gov (United States)

    Pyörälä, Eeva

    2014-09-01

    Faculty development requires practical tools for supporting teachers' professional development. In a modern medical education context, teachers need to adapt to various educational roles. This article describes how a role-based portfolio with a qualitative self-assessment scale was developed. It strives to encourage and support teachers' growth in different educational roles. The portfolio was developed between 2009 and 2012 at the University of Helsinki in dialogue with teachers involved in faculty development. It is based on the role framework presented by Harden and Crosby. Today, it also involves the educational premises of constructive alignment, reflection and a scholarly approach to teaching. The role-based portfolio has led the teachers to discover new educational roles and set goals in their professional development.

  1. Hierarchical model-based predictive control of a power plant portfolio

    DEFF Research Database (Denmark)

    Edlund, Kristian; Bendtsen, Jan Dimon; Jørgensen, John Bagterp

    2011-01-01

    One of the main difficulties in large-scale implementation of renewable energy in existing power systems is that the production from renewable sources is difficult to predict and control. For this reason, fast and efficient control of controllable power producing units – so-called “portfolio...... design for power system portfolio control, which aims specifically at meeting these demands.The design involves a two-layer hierarchical structure with clearly defined interfaces that facilitate an object-oriented implementation approach. The same hierarchical structure is reflected in the underlying...... optimisation problem, which is solved using Dantzig–Wolfe decomposition. This decomposition yields improved computational efficiency and better scalability compared to centralised methods.The proposed control scheme is compared to an existing, state-of-the-art portfolio control system (operated by DONG Energy...

  2. E-Portfolio improving learning in methematics pre-service teacher

    Directory of Open Access Journals (Sweden)

    Marcelo Almeida

    2012-06-01

    Full Text Available This research is focused on dimensions of mathematical thinking among preservice teachers learning through the use of e-Portfolios. The data came from portfolios created and reconstructed by future mathematics teachers. Their process of reviewing and republishing pages through the Internet was constantly saved and reviewed in turn by the researchers. Seven case studies were conducted. Results stress the importance of the use of ICT by pre-service teachers as an interface to become more reflective about their learning and to improve their knowledge. Besides being a tool to recognize different dimensions (technological, conceptual and communicative the e-Portfolios were a powerful resource for creating, publicizing ideas, and learning mathematics in different ways. The article also presents some methodological issues

  3. E-portfolios in lifelong learning

    NARCIS (Netherlands)

    Brouns, Francis; Vogten, Hubert; Janssen, José; Finders, Anton

    2013-01-01

    Brouns, F., Vogten, H., Janssen, J., & Finders, A. (2013, 14-15 November). E-portfolios in lifelong learning. Presentation given at the 2013 Conference on Technological Ecosystems for Enhancing Multiculturality, TEEM2013, Salamanca, Spain.

  4. Optimal diversification of the securities portfolio

    Directory of Open Access Journals (Sweden)

    Валентина Михайловна Андриенко

    2016-09-01

    Full Text Available The article deals with problems of the theory and methods of forming the optimal portfolio of financial markets. The analytical review of methods in their historical development is given. Recommendations on the use of a particular method depends on the specific conditions are formulated. The classical and alternative methods are considered. The main attention is paid to the analysis of the investment portfolio of derivative securities in B/S-market modelThe article deals with problems of the theory and methods of forming the optimal portfolio of financial markets. The analytical review of methods in their historical development is given. Recommendations on the use of a particular method depends on the specific conditions are formulated. The classical and alternative methods are considered. The main attention is paid to the analysis of the investment portfolio of derivative securities in -market model

  5. Active Multifamily Portfolio-Property Level data

    Data.gov (United States)

    Department of Housing and Urban Development — Multifamily Portfolio datasets (section 8 contracts) - The information has been compiled from multiple data sources within FHA or its contractors. HUD oversees more...

  6. ROMANIAN INVESTORS PORTFOLIO. ONLINE VERSUS ASSISTED TRADING

    Directory of Open Access Journals (Sweden)

    Ioana Ancuţa IANCU

    2017-05-01

    Full Text Available One of the most important aspects in deciding to trade online, alone, without the help of a broker, is the portfolio profitability. In this study, using the personal experience, survey data and secondary sources, we identify some factors that may influence the gain and the loss of investors which trade online. Our study contradicts other results from literature that claim that the transition from assisted to online trading is a big drawback in terms of portfolio profitability. By analyzing the performance of the portfolio when passing from assisted to online trading, we observe that half of the investors achieved identical profitability. We also observed that the efficiency of the portfolios belonging to the online investors that were assisted in the past by a broker for a short period, is lower compared to the ones assisted (in the past for a longer period.

  7. Decision-support tool for assessing future nuclear reactor generation portfolios

    International Nuclear Information System (INIS)

    Jain, Shashi; Roelofs, Ferry; Oosterlee, Cornelis W.

    2014-01-01

    Capital costs, fuel, operation and maintenance (O and M) costs, and electricity prices play a key role in the economics of nuclear power plants. Often standardized reactor designs are required to be locally adapted, which often impacts the project plans and the supply chain. It then becomes difficult to ascertain how these changes will eventually reflect in costs, which makes the capital costs component of nuclear power plants uncertain. Different nuclear reactor types compete economically by having either lower and less uncertain construction costs, increased efficiencies, lower and less uncertain fuel cycles and O and M costs etc. The decision making process related to nuclear power plants requires a holistic approach that takes into account the key economic factors and their uncertainties. We here present a decision-support tool that satisfactorily takes into account the major uncertainties in the cost elements of a nuclear power plant, to provide an optimal portfolio of nuclear reactors. The portfolio so obtained, under our model assumptions and the constraints considered, maximizes the combined returns for a given level of risk or uncertainty. These decisions are made using a combination of real option theory and mean–variance portfolio optimization. - Highlights: • Decisions to continue or abandon the construction of NPPs • Mean–variance portfolio of nuclear reactors • Sensitivity study of mean–variance portfolio of nuclear reactors

  8. EFFECT OF USING PORTFOLIO ASSESSMENT TO IMPROVE SCIENTIFIC ATTITUDE OF STUDENTS LEARNING PHYSICS IN HIGH SCHOOL

    Directory of Open Access Journals (Sweden)

    Gede Wartawan Putu

    2018-01-01

    Full Text Available This study aims to investigate the effect of portfolio assessment in teaching physics and scientific attitude. The research was conducted on students of high school in Singaraja. Research was an quasi- experimental study by using “The Posttest-Only Control Group Design”. The research involved 152 high school students of class X of science as samples, taken with multistage random sampling technique. Portfolio assessment was integrated with physics learning. The implementation of the portfolio assessment included four key elements such as the students' work folders, clear assessment criteria, and self-assessment, and conference between teacher and students. The data needed in this research was the students' scientific attitude which included the aspect of curiosity, respect for evidence, the willingness to change ideas, and critical reflection. Data needed in this research included scientific attitudes students. A Likert scale instrument was used to measure the scientific attitude students. Data were analyzed using analysis of variance with SPSS 20.0 at significance level α = 0.05. The results showed there are differences in the scientific attitude students who take physics learning with assessment portfolios and students who take physics learning with assessment of conventional. The findings of this study indicate that portfolio assessment in learning physics significantly affect the scientific attitude students.

  9. EFFECT OF USING PORTFOLIO ASSESSMENT TO IMPROVE SCIENTIFIC ATTITUDE OF STUDENTS LEARNING PHYSICS IN HIGH SCHOOL

    Directory of Open Access Journals (Sweden)

    putu wartawan

    2017-12-01

    Full Text Available This study aims to investigate the effect of portfolio assessment in teaching physics and scientific attitude. The research was conducted on students of high school  in Singaraja. Research was an  quasi- experimental study by using  “The Posttest-Only Control Group Design”.  The research involved 152 high school students of class X of science as samples, taken with multistage random sampling technique. Portfolio assessment was integrated with physics learning. The implementation of the portfolio assessment included four key elements such as the students' work folders, clear assessment criteria, and self-assessment, and conference between teacher and students.  The data needed in this research was the students' scientific attitude which included the aspect of curiosity, respect for evidence, the willingness to change ideas, and critical reflection. Data needed in this research included scientific attitudes students.  A Likert scale instrument was used to measure the scientific attitude students.  Data were analyzed using  analysis of variance with SPSS 20.0 at significance level a = 0.05. The results showed there are differences in the scientific attitude students who take physics learning with assessment portfolios and students who take physics learning with assessment of conventional.  The findings of this study indicate that portfolio assessment in learning physics significantly affect the scientific attitude students.

  10. Managing sovereign credit risk in bond portfolios

    OpenAIRE

    Bruder, Benjamin; Hereil, Pierre; Roncalli, Thierry

    2011-01-01

    With the recent development of the European debt crisis, traditional index bond management has been severely called into question. We focus here on the risk issues raised by the classical market-capitalization weighting scheme. We propose an approach to properly measure sovereign credit risk in a fixed-income portfolio. For that, we assume that CDS spreads follow a SABR process and we derive a sovereign credit risk measure based on CDS spreads and duration of portfolio bonds. We then consider...

  11. Online Learning of Commission Avoidant Portfolio Ensembles

    OpenAIRE

    Uziel, Guy; El-Yaniv, Ran

    2016-01-01

    We present a novel online ensemble learning strategy for portfolio selection. The new strategy controls and exploits any set of commission-oblivious portfolio selection algorithms. The strategy handles transaction costs using a novel commission avoidance mechanism. We prove a logarithmic regret bound for our strategy with respect to optimal mixtures of the base algorithms. Numerical examples validate the viability of our method and show significant improvement over the state-of-the-art.

  12. Subjective Life Horizon and Portfolio Choice

    OpenAIRE

    Spaenjers , Christophe; Spira, Sven Michael

    2013-01-01

    Using data from a U.S. household survey, we examine the empirical relation between subjective life horizon (i.e., the self-reported expectation of remaining life span) and portfolio choice. We find that equity portfolio shares are higher for investors with longer horizons, ceteris paribus, in line with theoretical predictions. This result is robust to controlling for optimism and health status, accounting for the endogeneity of equity market participation, or instrumenting subjective life hor...

  13. Portfolio Selection with Jumps under Regime Switching

    Directory of Open Access Journals (Sweden)

    Lin Zhao

    2010-01-01

    Full Text Available We investigate a continuous-time version of the mean-variance portfolio selection model with jumps under regime switching. The portfolio selection is proposed and analyzed for a market consisting of one bank account and multiple stocks. The random regime switching is assumed to be independent of the underlying Brownian motion and jump processes. A Markov chain modulated diffusion formulation is employed to model the problem.

  14. Equity Portfolio Management Using Option Price Information

    DEFF Research Database (Denmark)

    Christoffersen, Peter; Pan, Xuhui (Nick)

    We survey the recent academic literature that uses option-implied information to construct equity portfolios. Studies show that equity managers can earn a positive alpha by using information in individual equity options, by using stocks' exposure to information in market index options, and by using...... stocks' exposure to crude oil option information. Option-implied information can also help construct better mean-variance portfolios and better estimates of market beta....

  15. Systemic risk contributions: a credit portfolio approach

    OpenAIRE

    Düllmann, Klaus; Puzanova, Natalia

    2011-01-01

    We put forward a Merton-type multi-factor portfolio model for assessing banks' contributions to systemic risk. This model accounts for the major drivers of banks' systemic relevance: size, default risk and correlation of banks' assets as a proxy for interconnectedness. We measure systemic risk in terms of the portfolio expected shortfall (ES). Banks' (marginal) risk contributions are calculated based on partial derivatives of the ES in order to ensure a full risk allocation among institutions...

  16. Essays on portfolio choice with Bayesian methods

    OpenAIRE

    Kebabci, Deniz

    2007-01-01

    How investors should allocate assets to their portfolios in the presence of predictable components in asset returns is a question of great importance in finance. While early studies took the return generating process as given, recent studies have addressed issues such as parameter estimation and model uncertainty. My dissertation develops Bayesian methods for portfolio choice - and industry allocation in particular - under parameter and model uncertainty. The first chapter of my dissertation,...

  17. Optimal annuity portfolio under inflation risk

    DEFF Research Database (Denmark)

    Konicz, Agnieszka Karolina; Pisinger, David; Weissensteiner, Alex

    2015-01-01

    The paper investigates the importance of in ation-linked annuities to individuals facing in ation risk. Given the investment opportunities in nominal, real, and variable annuities, as well as cash and stocks, we investigate the consumption and investment decisions under two different objective fu...... and risk aversion, real annuities are a crucial asset in every portfolio. In addition, without investing in real annuities, the retiree has to rebalance the portfolio more frequently, and still obtains the lower and more volatile real consumption....

  18. Reinforcement Learning in Repeated Portfolio Decisions

    OpenAIRE

    Diao, Linan; Rieskamp, Jörg

    2011-01-01

    How do people make investment decisions when they receive outcome feedback? We examined how well the standard mean-variance model and two reinforcement models predict people's portfolio decisions. The basic reinforcement model predicts a learning process that relies solely on the portfolio's overall return, whereas the proposed extended reinforcement model also takes the risk and covariance of the investments into account. The experimental results illustrate that people reacted sensitively to...

  19. Testing for structural changes in large portfolios

    OpenAIRE

    Posch, Peter N.; Ullmann, Daniel; Wied, Dominik

    2015-01-01

    Model free tests for constant parameters often fail to detect structural changes in high dimensions. In practice, this corresponds to a portfolio with many assets and a reasonable long time series. We reduce the dimensionality of the problem by looking a compressed panel of time series obtained by cluster analysis and the principal components of the data. Using our methodology we are able to extend a test for a constant correlation matrix from a sub portfolio to whole indices a...

  20. Can E-Portfolio Improve Students’ Readiness to Find an IT Career?

    Directory of Open Access Journals (Sweden)

    Abdallah Tubaishat

    2015-06-01

    Full Text Available An E-Portfolio Assessment Management System (EAMS can be an innovative tool that provides students with flexible opportunities to demonstrate the acquisition of skills and abilities in an outcome-based institution. The system has been developed and used for the past ten years to create, reflect, revise, and structure students’ work. It is a repository management system that facilitates collecting, sharing, and presenting artifacts of student learning outcomes via a digital medium. Therefore, it provides students with flexible opportunities to demonstrate the acquisition of skills and abilities to demonstrate growth of achieving learning outcomes. The rationale of the EAMS is to allow students to demonstrate competences and reflect upon experiences to improve their learning and career readiness; hence, they are accountable for their learning. The system was built around two defined set of learning outcomes: institutionally agreed upon set of learning outcomes, and learning objectives that are related to major requirements. The purpose of this study is to analyze students’ perceptions and attitudes when using an e-portfolio to support their employment opportunities. The participants were 217 students in the College of Technological Innovation. The students reported that the developing of e-portfolios was extremely helpful. The results showed that students have positive opinions about using e-portfolios as a beneficial tool to support their readiness for employment; they believe an e-portfolio increases their confidence to find a job in the IT field because it can allow them to showcase artifacts that demonstrate competencies and reflect upon experiences, and they can provide their supervisors during their industrial training with an e-resume that includes views of their actual work of what they have learned and are able to do when they complete their degree. Employers then can review e-portfolios to select prospective employees work readiness

  1. The influence of electron energy on accumulation of color centers in reflective coatings based on ZnO

    International Nuclear Information System (INIS)

    Mikhajlov, M.M.; Sharafutdinova, V.V.

    1998-01-01

    The effect of the electron energy on the change of the intensity of bands of proper point defects of zinc oxides and thermo-regulating coatings on its basis for space vehicles is investigated in the range 10-100 keV. It is found that the growth of the intensity up to the energy ∼ 15 keV and then its decreasing is observed in the range 10-100 keV. The explanation of this singularity is proposed. It is found that the concentration of free electrons with the growth of the accelerated electron energy increases according to the exponential law

  2. Optimization of China's generating portfolio and policy implications based on portfolio theory

    International Nuclear Information System (INIS)

    Zhu, Lei; Fan, Ying

    2010-01-01

    This paper applies portfolio theory to evaluate China's 2020-medium-term plans for generating technologies and its generating portfolio. With reference to the risk of relevant generating-cost streams, the paper discusses China's future development of efficient (Pareto optimal) generating portfolios that enhance energy security in different scenarios, including CO 2 -emission-constrained scenarios. This research has found that the future adjustment of China's planned 2020 generating portfolio can reduce the portfolio's cost risk through appropriate diversification of generating technologies, but a price will be paid in the form of increased generating cost. In the CO 2 -emission-constrained scenarios, the generating-cost risk of China's planned 2020 portfolio is even greater than that of the 2005 portfolio, but increasing the proportion of nuclear power in the generating portfolio can reduce the cost risk effectively. For renewable-power generation, because of relatively high generating costs, it will be necessary to obtain stronger policy support to promote renewable-power development.

  3. Validity of the Learning Portfolio: Analysis of a Portfolio Proposal for the University

    Science.gov (United States)

    Gregori-Giralt, Eva; Menéndez-Varela, José Luis

    2015-01-01

    Validity is a central issue in portfolio-based assessment. This empirical study used a quantitative approach to analyse the validity of the inferences drawn from a disciplinary course work portfolio assessment comprising profession-specific and learning competencies. The study also examined the problems involved in the development of the…

  4. Direct characterization of the energy level alignments and molecular components in an organic hetero-junction by integrated photoemission spectroscopy and reflection electron energy loss spectroscopy analysis.

    Science.gov (United States)

    Yun, Dong-Jin; Shin, Weon-Ho; Bulliard, Xavier; Park, Jong Hwan; Kim, Seyun; Chung, Jae Gwan; Kim, Yongsu; Heo, Sung; Kim, Seong Heon

    2016-08-26

    A novel, direct method for the characterization of the energy level alignments at bulk-heterojunction (BHJ)/electrode interfaces on the basis of electronic spectroscopy measurements is proposed. The home-made in situ photoemission system is used to perform x-ray/ultraviolet photoemission spectroscopy (XPS/UPS), reflection electron energy loss spectroscopy (REELS) and inverse photoemission spectroscopy of organic-semiconductors (OSCs) deposited onto a Au substrate. Through this analysis system, we are able to obtain the electronic structures of a boron subphthalocyanine chloride:fullerene (SubPC:C60) BHJ and those of the separate OSC/electrode structures (SubPC/Au and C60/Au). Morphology and chemical composition analyses confirm that the original SubPC and C60 electronic structures remain unchanged in the electrodes prepared. Using this technique, we ascertain that the position and area of the nearest peak to the Fermi energy (EF = 0 eV) in the UPS (REELS) spectra of SubPC:C60 BHJ provide information on the highest occupied molecular orbital level (optical band gap) and combination ratio of the materials, respectively. Thus, extracting the adjusted spectrum from the corresponding SubPC:C60 BHJ UPS (REELS) spectrum reveals its electronic structure, equivalent to that of the C60 materials. This novel analytical approach allows complete energy-level determination for each combination ratio by separating its electronic structure information from the BHJ spectrum.

  5. Effects of Reflective Inquiry Instructional Technique on Students' Academic Achievement and Ability Level in Electronic Work Trade in Technical Colleges

    Science.gov (United States)

    Ogbuanya, T. C.; Owodunni, A. S.

    2015-01-01

    This study was designed to determine the effect of reflective inquiry instructional technique on achievement of students in Technical Colleges. The study adopted a pre-test, post-test, non-equivalent control group, quasi-experimental research design which involved groups of students in their intact class assigned to experimental group and control…

  6. The national portfolio of learning for postgraduate family medicine training in South Africa: experiences of registrars and supervisors in clinical practice.

    Science.gov (United States)

    Jenkins, Louis; Mash, Bob; Derese, Anselme

    2013-11-08

    In South Africa the submission of a portfolio of learning has become a national requirement for assessment of family medicine training. A national portfolio has been developed, validated and implemented. The aim of this study was to explore registrars' and supervisors' experience regarding the portfolio's educational impact, acceptability, and perceived usefulness for assessment of competence. Semi-structured interviews were conducted with 17 purposively selected registrars and supervisors from all eight South African training programmes. The portfolio primarily had an educational impact through making explicit the expectations of registrars and supervisors in the workplace. This impact was tempered by a lack of engagement in the process by registrars and supervisors who also lacked essential skills in reflection, feedback and assessment. The acceptability of the portfolio was limited by service delivery demands, incongruence between the clinical context and educational requirements, design of the logbook and easy availability of the associated tools. The use of the portfolio for formative assessment was strongly supported and appreciated, but was not always happening and in some cases registrars had even organised peer assessment. Respondents were unclear as to how the portfolio would be used for summative assessment. The learning portfolio had a significant educational impact in shaping work-place based supervision and training and providing formative assessment. Its acceptability and usefulness as a learning tool should increase over time as supervisors and registrars become more competent in its use. There is a need to clarify how it will be used in summative assessment.

  7. Ant colony algorithm for clustering in portfolio optimization

    Science.gov (United States)

    Subekti, R.; Sari, E. R.; Kusumawati, R.

    2018-03-01

    This research aims to describe portfolio optimization using clustering methods with ant colony approach. Two stock portfolios of LQ45 Indonesia is proposed based on the cluster results obtained from ant colony optimization (ACO). The first portfolio consists of assets with ant colony displacement opportunities beyond the defined probability limits of the researcher, where the weight of each asset is determined by mean-variance method. The second portfolio consists of two assets with the assumption that each asset is a cluster formed from ACO. The first portfolio has a better performance compared to the second portfolio seen from the Sharpe index.

  8. RISK MANAGEMENT OF INVESTMENT PORTFOLIO BY FUTURE

    Directory of Open Access Journals (Sweden)

    K. Kerimov Alexandr

    2017-01-01

    Full Text Available The article considers the problem of the dynamic risk management of the investment portfolio using future con- tracts. The management starts with the concept of effective inhomogeneous portfolios, which contain futures together with underlying asserts. The effective portfolios are defined as the ones of the minimal dispersion with the expected return greater or equal to the specified value. Risk is measured by the probability of losing of a certain part of the portfolio value. The control parameters are the number of futures for each asset of portfolio, which is defined from the condition of effec- tiveness of portfolio and risk acceptability on each step.The effective adaptive strategies of portfolio risk management together with comparative analysis on a concrete example are presented. The proposed approach provides the forecast correction of the expected income and its variance for the assets with the emergence of new data. The financial time series are determined by volatility clustering, i.e. relative or absolute price changes tend to keep high or low magnitude for some time, with the result that clusters are created - periods of high or low volatility. Then adaptive estimate of correlational relationships between asset prices are essential because the degree of correlational relationship also changes in time. So the correlation of future and spot price changes considerably increases while approaching to performance of contracts. For taking into account of data instability of dispersion and correlation simple methods of volatility forecasting and correlation of relative changes of price data based on exponential smoothing are implemented.

  9. Exploring the role of assessment criteria during teachers' collaborative judgement processes of students' portfolios

    NARCIS (Netherlands)

    Schaaf, van der M.F.; Baartman, L.K.J.; Prins, F.J.

    2012-01-01

    Student portfolios are increasingly used for assessing student competences in higher education, but results about the construct validity of portfolio assessment are mixed. A prerequisite for construct validity is that the portfolio assessment is based on relevant portfolio content. Assessment

  10. PERCEPTION OF ACADEMIC COURSE OF DENTISTRY ON THE USE OF PORTFOLIO AS A METHOD EVALUATIVE

    Directory of Open Access Journals (Sweden)

    Jacques Antonio Cavalcante Maciel

    2014-05-01

    Full Text Available The portfolio is targeted as an innovative method of learning that allows you to record the reflections and impressions on the subject or course, promoting effective learning from experiences. This present study has aimed to describe the experience of the use of portfolios as a method of assessing learning in dental students and assess students' perceptions about the method. The research was quantitative, descriptive. The survey was conducted in dentistry course at Sobral UFC. We used a questionnaire containing ten questions to 23 students of the seventh semester of Dentistry, who attended Sobral UFC-modules of Community Health III between 2011.2 and had as one of evaluative methods to build the Portfolio. The portfolio was defined by students as a reflective report of the activities developed in theory and practice, and an evaluation method well accepted by academics. You can see that the evaluation method was efficient in its purpose, leading academics to develop a critical view on the theme developed in the classroom and that proved a facilitator in the process of teaching and learning for students.

  11. Reflecting reflection in supervision

    DEFF Research Database (Denmark)

    Lystbæk, Christian Tang

    associated with reflection and an exploration of alternative conceptions that view reflection within the context of settings which have a more group- and team-based orientation. Drawing on an action research project on health care supervision, the paper questions whether we should reject earlier views...... of reflection, rehabilitate them in order to capture broader connotations or move to new ways of regarding reflection that are more in keeping with not only reflective but also emotive, normative and formative views on supervision. The paper presents a critical perspective on supervision that challenge...... the current reflective paradigm I supervision and relate this to emotive, normative and formative views supervision. The paper is relevant for Nordic educational research into the supervision and guidance...

  12. Performance of salmon fishery portfolios across western North America.

    Science.gov (United States)

    Griffiths, Jennifer R; Schindler, Daniel E; Armstrong, Jonathan B; Scheuerell, Mark D; Whited, Diane C; Clark, Robert A; Hilborn, Ray; Holt, Carrie A; Lindley, Steven T; Stanford, Jack A; Volk, Eric C

    2014-12-01

    Quantifying the variability in the delivery of ecosystem services across the landscape can be used to set appropriate management targets, evaluate resilience and target conservation efforts. Ecosystem functions and services may exhibit portfolio-type dynamics, whereby diversity within lower levels promotes stability at more aggregated levels. Portfolio theory provides a framework to characterize the relative performance among ecosystems and the processes that drive differences in performance. We assessed Pacific salmon Oncorhynchus spp. portfolio performance across their native latitudinal range focusing on the reliability of salmon returns as a metric with which to assess the function of salmon ecosystems and their services to humans. We used the Sharpe ratio (e.g. the size of the total salmon return to the portfolio relative to its variability (risk)) to evaluate the performance of Chinook and sockeye salmon portfolios across the west coast of North America. We evaluated the effects on portfolio performance from the variance of and covariance among salmon returns within each portfolio, and the association between portfolio performance and watershed attributes. We found a positive latitudinal trend in the risk-adjusted performance of Chinook and sockeye salmon portfolios that also correlated negatively with anthropogenic impact on watersheds (e.g. dams and land-use change). High-latitude Chinook salmon portfolios were on average 2·5 times more reliable, and their portfolio risk was mainly due to low variance in the individual assets. Sockeye salmon portfolios were also more reliable at higher latitudes, but sources of risk varied among the highest performing portfolios. Synthesis and applications . Portfolio theory provides a straightforward method for characterizing the resilience of salmon ecosystems and their services. Natural variability in portfolio performance among undeveloped watersheds provides a benchmark for restoration efforts. Locally and regionally

  13. Performance of salmon fishery portfolios across western North America

    Science.gov (United States)

    Griffiths, Jennifer R; Schindler, Daniel E; Armstrong, Jonathan B; Scheuerell, Mark D; Whited, Diane C; Clark, Robert A; Hilborn, Ray; Holt, Carrie A; Lindley, Steven T; Stanford, Jack A; Volk, Eric C

    2014-01-01

    Quantifying the variability in the delivery of ecosystem services across the landscape can be used to set appropriate management targets, evaluate resilience and target conservation efforts. Ecosystem functions and services may exhibit portfolio-type dynamics, whereby diversity within lower levels promotes stability at more aggregated levels. Portfolio theory provides a framework to characterize the relative performance among ecosystems and the processes that drive differences in performance. We assessed Pacific salmon Oncorhynchus spp. portfolio performance across their native latitudinal range focusing on the reliability of salmon returns as a metric with which to assess the function of salmon ecosystems and their services to humans. We used the Sharpe ratio (e.g. the size of the total salmon return to the portfolio relative to its variability (risk)) to evaluate the performance of Chinook and sockeye salmon portfolios across the west coast of North America. We evaluated the effects on portfolio performance from the variance of and covariance among salmon returns within each portfolio, and the association between portfolio performance and watershed attributes. We found a positive latitudinal trend in the risk-adjusted performance of Chinook and sockeye salmon portfolios that also correlated negatively with anthropogenic impact on watersheds (e.g. dams and land-use change). High-latitude Chinook salmon portfolios were on average 2·5 times more reliable, and their portfolio risk was mainly due to low variance in the individual assets. Sockeye salmon portfolios were also more reliable at higher latitudes, but sources of risk varied among the highest performing portfolios. Synthesis and applications. Portfolio theory provides a straightforward method for characterizing the resilience of salmon ecosystems and their services. Natural variability in portfolio performance among undeveloped watersheds provides a benchmark for restoration efforts. Locally and regionally

  14. Portfolio optimization with skewness and kurtosis

    Science.gov (United States)

    Lam, Weng Hoe; Jaaman, Saiful Hafizah Hj.; Isa, Zaidi

    2013-04-01

    Mean and variance of return distributions are two important parameters of the mean-variance model in portfolio optimization. However, the mean-variance model will become inadequate if the returns of assets are not normally distributed. Therefore, higher moments such as skewness and kurtosis cannot be ignored. Risk averse investors prefer portfolios with high skewness and low kurtosis so that the probability of getting negative rates of return will be reduced. The objective of this study is to compare the portfolio compositions as well as performances between the mean-variance model and mean-variance-skewness-kurtosis model by using the polynomial goal programming approach. The results show that the incorporation of skewness and kurtosis will change the optimal portfolio compositions. The mean-variance-skewness-kurtosis model outperforms the mean-variance model because the mean-variance-skewness-kurtosis model takes skewness and kurtosis into consideration. Therefore, the mean-variance-skewness-kurtosis model is more appropriate for the investors of Malaysia in portfolio optimization.

  15. Declarative Modeling for Production Order Portfolio Scheduling

    Directory of Open Access Journals (Sweden)

    Banaszak Zbigniew

    2014-12-01

    Full Text Available A declarative framework enabling to determine conditions as well as to develop decision-making software supporting small- and medium-sized enterprises aimed at unique, multi-project-like and mass customized oriented production is discussed. A set of unique production orders grouped into portfolio orders is considered. Operations executed along different production orders share available resources following a mutual exclusion protocol. A unique product or production batch is completed while following a given activity’s network order. The problem concerns scheduling a newly inserted project portfolio subject to constraints imposed by a multi-project environment The answers sought are: Can a given project portfolio specified by its cost and completion time be completed within the assumed time period in a manufacturing system in hand? Which manufacturing system capability guarantees the completion of a given project portfolio ordered under assumed cost and time constraints? The considered problems regard finding a computationally effective approach aimed at simultaneous routing and allocation as well as batching and scheduling of a newly ordered project portfolio subject to constraints imposed by a multi-project environment. The main objective is to provide a declarative model enabling to state a constraint satisfaction problem aimed at multi-project-like and mass customized oriented production scheduling. Multiple illustrative examples are discussed.

  16. Analysis of the EBT3 Gafchromic film irradiated with 6 MV photons and 6 MeV electrons using reflective mode scanners.

    Science.gov (United States)

    Farah, Nicolas; Francis, Ziad; Abboud, Marie

    2014-09-01

    We explore in our study the effects of electrons and X-rays irradiations on the newest version of the Gafchromic EBT3 film. Experiments are performed using the Varian "TrueBeam 1.6" medical accelerator delivering 6 MV X-ray photons and 6 MeV electron beams as desired. The main interest is to compare the responses of EBT3 films exposed to two separate beams of electrons and photons, for radiation doses ranging up to 500 cGy. The analysis is done on a flatbed EPSON 10000 XL scanner and cross checked on a HP Scanjet 4850 scanner. Both scanners are used in reflection mode taking into account landscape and portrait scanning positions. After thorough verifications, the reflective scanning method can be used on EBT3 as an economic alternative to the transmission method which was also one of the goals of this study. A comparison is also done between single scan configuration including all samples in a single A4 (HP) or A3 (EPSON) format area and multiple scan procedure where each sample is scanned separately on its own. The images analyses are done using the ImageJ software. Results show significant influence of the scanning configuration but no significant differences between electron and photon irradiations for both single and multiple scan configurations. In conclusion, the film provides a reliable relative dose measurement method for electrons and photons irradiations in the medical field applications. Copyright © 2014 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  17. Investigation of the winds and electron concentration variability in the D region of the ionosphere by the partial-reflection radar technique

    International Nuclear Information System (INIS)

    Weiland, R.M.; Bowhill, S.A.

    1981-12-01

    The development and first observations of the partial-reflection drifts experiment at Urbana, Illinois (40 N) are described. The winds data from the drifts experiment are compared with electron concentration data obtained by the differential-absorption technique to study the possible meteorological causes of the winter anomaly in the mesosphere at midlatitudes. Winds data obtained by the meteor-radar experiment at Urbana are also compared with electron concentration data measured at Urban. A significant correlation is shown is both cases between southward winds and increasing electron concentration measured at the same location during winter. The possibility of stratospheric/mesospheric coupling is investigated by comparing satellite-measured 0.4 mbar geopotential data with mesospheric electron concentration data. No significant coupling was observed. The winds measured at Saskatoon, Saskatchewan (52 N) are compared with the electron concentrations measured at Urban, yielding constant fixed relationship, but significant correlations for short segments of the winter. A significant coherence is observed at discrete frequencies during segments of the winter

  18. Probing ultrafast changes of spin and charge density profiles with resonant XUV magnetic reflectivity at the free-electron laser FERMI

    Directory of Open Access Journals (Sweden)

    C. Gutt

    2017-09-01

    Full Text Available We report the results of resonant magnetic XUV reflectivity experiments performed at the XUV free-electron laser FERMI. Circularly polarized XUV light with the photon energy tuned to the Fe M2,3 edge is used to measure resonant magnetic reflectivities and the corresponding Q-resolved asymmetry of a Permalloy/Ta/Permalloy trilayer film. The asymmetry exhibits ultrafast changes on 240 fs time scales upon pumping with ultrashort IR laser pulses. Depending on the value of the wavevector transfer Qz, we observe both decreasing and increasing values of the asymmetry parameter, which is attributed to ultrafast changes in the vertical spin and charge density profiles of the trilayer film.

  19. Minimum Variance Portfolios in the Brazilian Equity Market

    Directory of Open Access Journals (Sweden)

    Alexandre Rubesam

    2013-03-01

    Full Text Available We investigate minimum variance portfolios in the Brazilian equity market using different methods to estimate the covariance matrix, from the simple model of using the sample covariance to multivariate GARCH models. We compare the performance of the minimum variance portfolios to those of the following benchmarks: (i the IBOVESPA equity index, (ii an equally-weighted portfolio, (iii the maximum Sharpe ratio portfolio and (iv the maximum growth portfolio. Our results show that the minimum variance portfolio has higher returns with lower risk compared to the benchmarks. We also consider long-short 130/30 minimum variance portfolios and obtain similar results. The minimum variance portfolio invests in relatively few stocks with low βs measured with respect to the IBOVESPA index, being easily replicable by individual and institutional investors alike.

  20. Application of Portfolio Theory in Recovery Planning for Pacific Salmon.

    Science.gov (United States)

    Ecological applications of portfolio theory demonstrate the utility of this analytical framework for understanding the stability of commercial and indigenous Pacific Salmon fisheries. Portfolio theory also has the potential to aid in recovery planning for threatened and endangere...

  1. Dynamics of market correlations: taxonomy and portfolio analysis.

    Science.gov (United States)

    Onnela, J-P; Chakraborti, A; Kaski, K; Kertész, J; Kanto, A

    2003-11-01

    The time dependence of the recently introduced minimum spanning tree description of correlations between stocks, called the "asset tree" has been studied in order to reflect the financial market taxonomy. The nodes of the tree are identified with stocks and the distance between them is a unique function of the corresponding element of the correlation matrix. By using the concept of a central vertex, chosen as the most strongly connected node of the tree, an important characteristic is defined by the mean occupation layer. During crashes, due to the strong global correlation in the market, the tree shrinks topologically, and this is shown by a low value of the mean occupation layer. The tree seems to have a scale-free structure where the scaling exponent of the degree distribution is different for "business as usual" and "crash" periods. The basic structure of the tree topology is very robust with respect to time. We also point out that the diversification aspect of portfolio optimization results in the fact that the assets of the classic Markowitz portfolio are always located on the outer leaves of the tree. Technical aspects such as the window size dependence of the investigated quantities are also discussed.

  2. Dynamics of market correlations: Taxonomy and portfolio analysis

    Science.gov (United States)

    Onnela, J.-P.; Chakraborti, A.; Kaski, K.; Kertész, J.; Kanto, A.

    2003-11-01

    The time dependence of the recently introduced minimum spanning tree description of correlations between stocks, called the “asset tree” has been studied in order to reflect the financial market taxonomy. The nodes of the tree are identified with stocks and the distance between them is a unique function of the corresponding element of the correlation matrix. By using the concept of a central vertex, chosen as the most strongly connected node of the tree, an important characteristic is defined by the mean occupation layer. During crashes, due to the strong global correlation in the market, the tree shrinks topologically, and this is shown by a low value of the mean occupation layer. The tree seems to have a scale-free structure where the scaling exponent of the degree distribution is different for “business as usual” and “crash” periods. The basic structure of the tree topology is very robust with respect to time. We also point out that the diversification aspect of portfolio optimization results in the fact that the assets of the classic Markowitz portfolio are always located on the outer leaves of the tree. Technical aspects such as the window size dependence of the investigated quantities are also discussed.

  3. Quantitative determination of iron, copper, lead, chromium and nickel in electronic waste samples using total reflection x-ray fluorescence spectroscopy

    International Nuclear Information System (INIS)

    Elaseer, A. S.; Musbah, A. S; Ammar, M. M. G.; Salah, M. A.; Aisha, E. A.

    2015-01-01

    Total reflection x-ray fluorescence spectroscopy in conjunction with microwave assisted extraction technique was used for the analysis of twenty electronic waste samples. The analysis was limited to the printed circuit boards of electronic devices. Iron, copper, lead, chromium and nickel were quantitatively determined in the samples. The samples were carefully milled to fine powder and 50mg was digested by acid using microwave digestion procedure. The digested samples solution was spread together with gallium as internal standard on the reflection disk and analyzed. The results showed that the cassette recorder boards contain the highest concentration of iron, lead and nickel. The average concentrations of these metals were 78, 73 and 71g/Kg respectively. Computer boards contained the highest copper average concentration 39g/Kg. the highest chromium average concentration 3.6 g/Kg was in mobile phone boards. Measurements were made using PicoTAX portable x-ray device. the instrument was used for quantitative multi-element analysis. An air cooled x-ray tube (40KV, 1 mA) with Mo target and Be window was used as x-ray source. The optics of the device was a multilayer Ni/C, 17.5 keV, 80% reflectivity provides analysis of elements from Si to Zr (K series) and Rh to U (L series). A Si PIN-diode detector (7mm"2, 195eV) was used for the elements detection. In this study heavy metals average concentration in electronic circuit boards in the in the order of iron (35.25g/kg), copper (21.14g/Kg), lead (16.59g/Kg), nickel (16.01g/Kg) and chromium (1.07g/Kg).(author)

  4. Markowitz portfolio optimization model employing fuzzy measure

    Science.gov (United States)

    Ramli, Suhailywati; Jaaman, Saiful Hafizah

    2017-04-01

    Markowitz in 1952 introduced the mean-variance methodology for the portfolio selection problems. His pioneering research has shaped the portfolio risk-return model and become one of the most important research fields in modern finance. This paper extends the classical Markowitz's mean-variance portfolio selection model applying the fuzzy measure to determine the risk and return. In this paper, we apply the original mean-variance model as a benchmark, fuzzy mean-variance model with fuzzy return and the model with return are modeled by specific types of fuzzy number for comparison. The model with fuzzy approach gives better performance as compared to the mean-variance approach. The numerical examples are included to illustrate these models by employing Malaysian share market data.

  5. Teaching ePortfolios in Teacher Education

    Directory of Open Access Journals (Sweden)

    Peter Groißböck

    2012-11-01

    Full Text Available Especially when starting their career in the induction phase, young teachers need personal, profession-related and social support. Young teachers can get personal support with a mentoring system, profession-related support in seminars and social support with peer-learning. E-portfolios offer ways to accompany those learning processes and are a central tool for the documentation of individual student progress in the induction phase of teachers. In this article a concept of teaching e-portfolios for the induction phase is presented, showing a basic structure, essential conditions and possible risks. Additionally this article also includes practical thoughts to the use of e-portfolios in basic teacher education and further teacher training.

  6. Enhanced index tracking modelling in portfolio optimization

    Science.gov (United States)

    Lam, W. S.; Hj. Jaaman, Saiful Hafizah; Ismail, Hamizun bin

    2013-09-01

    Enhanced index tracking is a popular form of passive fund management in stock market. It is a dual-objective optimization problem, a trade-off between maximizing the mean return and minimizing the risk. Enhanced index tracking aims to generate excess return over the return achieved by the index without purchasing all of the stocks that make up the index by establishing an optimal portfolio. The objective of this study is to determine the optimal portfolio composition and performance by using weighted model in enhanced index tracking. Weighted model focuses on the trade-off between the excess return and the risk. The results of this study show that the optimal portfolio for the weighted model is able to outperform the Malaysia market index which is Kuala Lumpur Composite Index because of higher mean return and lower risk without purchasing all the stocks in the market index.

  7. Belief Propagation Algorithm for Portfolio Optimization Problems.

    Science.gov (United States)

    Shinzato, Takashi; Yasuda, Muneki

    2015-01-01

    The typical behavior of optimal solutions to portfolio optimization problems with absolute deviation and expected shortfall models using replica analysis was pioneeringly estimated by S. Ciliberti et al. [Eur. Phys. B. 57, 175 (2007)]; however, they have not yet developed an approximate derivation method for finding the optimal portfolio with respect to a given return set. In this study, an approximation algorithm based on belief propagation for the portfolio optimization problem is presented using the Bethe free energy formalism, and the consistency of the numerical experimental results of the proposed algorithm with those of replica analysis is confirmed. Furthermore, the conjecture of H. Konno and H. Yamazaki, that the optimal solutions with the absolute deviation model and with the mean-variance model have the same typical behavior, is verified using replica analysis and the belief propagation algorithm.

  8. A Bicriteria Approach Identifying Nondominated Portfolios

    Directory of Open Access Journals (Sweden)

    Javier Pereira

    2014-01-01

    Full Text Available We explore a portfolio constructive model, formulated in terms of satisfaction of a given set of technical requirements, with the minimum number of projects and minimum redundancy. An algorithm issued from robust portfolio modeling is adapted to a vector model, modifying the dominance condition as convenient, in order to find the set of nondominated portfolios, as solutions of a bicriteria integer linear programming problem. In order to improve the former algorithm, a process finding an optimal solution of a monocriteria version of this problem is proposed, which is further used as a first feasible solution aiding to find nondominated solutions more rapidly. Next, a sorting process is applied on the input data or information matrix, which is intended to prune nonfeasible solutions early in the constructive algorithm. Numerical examples show that the optimization and sorting processes both improve computational efficiency of the original algorithm. Their limits are also shown on certain complex instances.

  9. Robust Portfolio Optimization using CAPM Approach

    Directory of Open Access Journals (Sweden)

    mohsen gharakhani

    2013-08-01

    Full Text Available In this paper, a new robust model of multi-period portfolio problem has been developed. One of the key concerns in any asset allocation problem is how to cope with uncertainty about future returns. There are some approaches in the literature for this purpose including stochastic programming and robust optimization. Applying these techniques to multi-period portfolio problem may increase the problem size in a way that the resulting model is intractable. In this paper, a novel approach has been proposed to formulate multi-period portfolio problem as an uncertain linear program assuming that asset return follows the single-index factor model. Robust optimization technique has been also used to solve the problem. In order to evaluate the performance of the proposed model, a numerical example has been applied using simulated data.

  10. Portfolio Selection Using Level Crossing Analysis

    Science.gov (United States)

    Bolgorian, Meysam; Shirazi, A. H.; Jafari, G. R.

    Asset allocation is one of the most important and also challenging issues in finance. In this paper using level crossing analysis we introduce a new approach for portfolio selection. We introduce a portfolio index that is obtained based on minimizing the waiting time to receive known return and risk values. By the waiting time, we mean time that a special level is observed in average. The advantage of this approach is that the investors are able to set their goals based on gaining return and knowing the average waiting time and risk value at the same time. As an example we use our model for forming portfolio of stocks in Tehran Stock Exchange (TSE).

  11. Belief Propagation Algorithm for Portfolio Optimization Problems.

    Directory of Open Access Journals (Sweden)

    Takashi Shinzato

    Full Text Available The typical behavior of optimal solutions to portfolio optimization problems with absolute deviation and expected shortfall models using replica analysis was pioneeringly estimated by S. Ciliberti et al. [Eur. Phys. B. 57, 175 (2007]; however, they have not yet developed an approximate derivation method for finding the optimal portfolio with respect to a given return set. In this study, an approximation algorithm based on belief propagation for the portfolio optimization problem is presented using the Bethe free energy formalism, and the consistency of the numerical experimental results of the proposed algorithm with those of replica analysis is confirmed. Furthermore, the conjecture of H. Konno and H. Yamazaki, that the optimal solutions with the absolute deviation model and with the mean-variance model have the same typical behavior, is verified using replica analysis and the belief propagation algorithm.

  12. Chemical and structural composition study through transmission and reflection electron microscopy and X-ray microanalysis of damaged duramater cardiac valves

    International Nuclear Information System (INIS)

    Verginelli, G.; Didio, L.J.A.; Puig, L.B.; Allen, D.J.; Highinson, G.H.; Zerbini, E.J.

    1982-01-01

    Ten malfunctioning durameter aortic prosthesis, excised surgically after 44 to 54 months of implantation were studied through transmission and reflection electron microscopy and X-ray microanalysis. Duramater extracted at necropsy but not used for valve prosthesis and duramater aortic prosthesis not implanted in patients were used as controls. It was concluded that homologous duramater valves present subcellular changes following implantation, with degenerating and proliferating areas which could correspond either to normal adaptation or consequence of degeneration - rebuilding which begins with implantation; it is also emphazised the need for ultramicroscopic studies in evaluating biological tissues and establishing its applicability in cardiac surgery. (M.A.C.) [pt

  13. Construction of uncertainty sets for portfolio selection problems

    OpenAIRE

    Wiechers, Christof

    2011-01-01

    While modern portfolio theory grounds on the trade-off between portfolio return and portfolio variance to determine the optimal investment decision, postmodern portfolio theory uses downside risk measures instead of the variance. Prominent examples are given by the risk measures Value-at-Risk and its coherent extension, Conditional Value-at-Risk. When avoiding distributional assumptions on the process that generates the risky assets' returns, historical return data or expert knowledge remain ...

  14. An Arbitrary Benchmark CAPM: One Additional Frontier Portfolio is Sufficient

    OpenAIRE

    Ekern, Steinar

    2008-01-01

    First draft: July 16, 2008 This version: October 7, 2008 The benchmark CAPM linearly relates the expected returns on an arbitrary asset, an arbitrary benchmark portfolio, and an arbitrary MV frontier portfolio. The benchmark is not required to be on the frontier and may be non-perfectly correlated with the frontier portfolio. The benchmark CAPM extends and generalizes previous CAPM formulations, including the zero beta, two correlated frontier portfolios, riskless augmented frontier, an...

  15. Log-Optimal Portfolio Selection Using the Blackwell Approachability Theorem

    OpenAIRE

    V'yugin, Vladimir

    2014-01-01

    We present a method for constructing the log-optimal portfolio using the well-calibrated forecasts of market values. Dawid's notion of calibration and the Blackwell approachability theorem are used for computing well-calibrated forecasts. We select a portfolio using this "artificial" probability distribution of market values. Our portfolio performs asymptotically at least as well as any stationary portfolio that redistributes the investment at each round using a continuous function of side in...

  16. Asset Allocation and Optimal Contract for Delegated Portfolio Management

    Science.gov (United States)

    Liu, Jingjun; Liang, Jianfeng

    This article studies the portfolio selection and the contracting problems between an individual investor and a professional portfolio manager in a discrete-time principal-agent framework. Portfolio selection and optimal contracts are obtained in closed form. The optimal contract was composed with the fixed fee, the cost, and the fraction of excess expected return. The optimal portfolio is similar to the classical two-fund separation theorem.

  17. ALPHA-BETA SEPARATION PORTFOLIO STRATEGIES FOR ISLAMIC FINANCE

    OpenAIRE

    Valentyn Khokhlov

    2016-01-01

    The purpose of this paper is to develop a mathematical alpha-beta separation model that can be used to create a core-satellite portfolio management strategy that complies with the principles of Islamic finance. Methodology. Core-satellite portfolio construction methodology is used to implement the alpha-beta separation approach, where the core part of the portfolio is managed using the tracking error minimization strategy, and the satellite part of the portfolio is managed using the mean-vari...

  18. Two steps forward, one step back: the intricacies of engaging with e-portfolios in nursing undergraduate education.

    Science.gov (United States)

    Andrews, Tulsa; Cole, Clare

    2015-04-01

    To share the experience of implementing and refining the use of e-portfolios into an undergraduate nursing degree. This is a reflective piece that explores the hurdles experienced in introducing and maintaining e-portfolio's into higher education, particularly in undergraduate nursing curricula. Nil Review of the literature, and comparing and contrasting this against the experience of the authors. Hurdles included access to computer and quality internet connections, along with the levels of IT literacy of staff, and the common misconception that all students are IT savvy. What was also evident was how the need for both pedagogical and technical support to both staff and students was paramount in achieving an understanding of the software, and the scope and perspective of e-portfolio pedagogy. With each of these hurdles, staff reluctance to engage in e-portfolio use in the tertiary sector was evident. On reflection of each of these challenges, the authors identified that their experience mirrored other tertiary institutions in that a single hurdle alone is not responsible for fragmented e-portfolio implementation, but a combination of factors. Through exploring recommendations from other tertiary institutions, the authors recognize the limitations within their own working environment that contributed to the pitfalls experienced. Despite e-portfolios being introduced into higher education for over a decade, its successful implementation into undergraduate nursing curricula continues to be fraught with pitfalls, creating the sense of moving backwards more so than forwards. As with any new learning tool, careful consideration needs to be given to comprehensive planning, implementation, review and evaluation to either prevent the hurdles identified, or limit their impact on the quality of the portfolio produced and the learning attained from the process. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. [Portfolio in nursing school: myth or reality].

    Science.gov (United States)

    Garnier, Chantal; Marchand, Claire

    2012-09-01

    The portfolio is a new tool that has been introduced for the setting up of a new program concerning the nurse training. It aims at the would-be nurse to improve their self-reliance and make them assess themselves through a critical and reflexive approach. Indeed, the portfolio is mostly made up of sheets that the student has to fill in when describing and analysing several professional conditions. This study is about the assessment of the relevance in the portfolio that each nurse student owns in order to make them improve their reflexive practical. The work will, thus, suggest different ways of thinking and improving the use of the tool. 30 portfolios were chosen randomly among the 2nd year students, because 180 analysis were assessed thanks to a grid. 10 viewpoints from volunteer students were gathered after several semi directive interviews. The qualitative and evaluative analysis shows that the students develop the reflexive practical throughout their trainings. It seems, indeed, relevant to choose the portfolio in order to help the students to develop this way of working. According to them, there are several positive points such as the distance towards an event, an awareness-raising of the acquisition, feedbacks about the quality of the text by the trainer and an ability to assess oneself. Yet, even though it was created 18 months ago, there are some limits such as the too short period of mentoring and feedback, the lack of time for the students to write their analysis, the fact that it is not a practical tool, and the unclear description of assessment criteria. In order to fulfil the needs, some solutions are to be found. The portfolio is clearly helpful for the students who wish to increase/improve gradually their reflexive practice. Thus, the trainer's role is crucial, when he is a supervisor.

  20. Natural gas contracts in efficient portfolios

    Energy Technology Data Exchange (ETDEWEB)

    Sutherland, R.J.

    1994-12-01

    This report addresses the {open_quotes}contracts portfolio{close_quotes} issue of natural gas contracts in support of the Domestic Natural Gas and Oil Initiative (DGOI) published by the U.S. Department of Energy in 1994. The analysis is a result of a collaborative effort with the Public Service Commission of the State of Maryland to consider {open_quotes}reforms that enhance the industry`s competitiveness{close_quotes}. The initial focus of our collaborative effort was on gas purchasing and contract portfolios; however, it became apparent that efficient contracting to purchase and use gas requires a broader consideration of regulatory reform. Efficient portfolios are obtained when the holder of the portfolio is affected by and is responsible for the performance of the portfolio. Natural gas distribution companies may prefer a diversity of contracts, but the efficient use of gas requires that the local distribution company be held accountable for its own purchases. Ultimate customers are affected by their own portfolios, which they manage efficiently by making their own choices. The objectives of the DGOI, particularly the efficient use of gas, can be achieved when customers have access to suppliers of gas and energy services under an improved regulatory framework. The evolution of the natural gas market during the last 15 years is described to account for the changing preferences toward gas contracts. Long-term contracts for natural gas were prevalent before the early 1980s, primarily because gas producers had few options other than to sell to a single pipeline company, and this pipeline company, in turn, was the only seller to a gas distribution company.

  1. Improving the automatic inversion of digital Alouette/ISIS ionogram reflection traces into topside electron density profiles

    Czech Academy of Sciences Publication Activity Database

    Benson, R. F.; Truhlík, Vladimír; Huang, X.; Wang, YL.; Bilitza, D.

    2012-01-01

    Roč. 47, č. 4 (2012), RS0L04/1-RS0L04/10 ISSN 0048-6604 R&D Projects: GA ČR GAP209/10/2086 Institutional support: RVO:68378289 Keywords : ionosphere * electron concentration * radio waves * solar activity Subject RIV: DG - Athmosphere Sciences, Meteorology Impact factor: 1.000, year: 2012 http://onlinelibrary.wiley.com/doi/10.1029/2011RS004963/abstract

  2. Portfolios Dominating Indices: Optimization with Second-Order Stochastic Dominance Constraints vs. Minimum and Mean Variance Portfolios

    Directory of Open Access Journals (Sweden)

    Neslihan Fidan Keçeci

    2016-10-01

    Full Text Available The paper compares portfolio optimization with the Second-Order Stochastic Dominance (SSD constraints with mean-variance and minimum variance portfolio optimization. As a distribution-free decision rule, stochastic dominance takes into account the entire distribution of return rather than some specific characteristic, such as variance. The paper is focused on practical applications of the portfolio optimization and uses the Portfolio Safeguard (PSG package, which has precoded modules for optimization with SSD constraints, mean-variance and minimum variance portfolio optimization. We have done in-sample and out-of-sample simulations for portfolios of stocks from the Dow Jones, S&P 100 and DAX indices. The considered portfolios’ SSD dominate the Dow Jones, S&P 100 and DAX indices. Simulation demonstrated a superior performance of portfolios with SD constraints, versus mean-variance and minimum variance portfolios.

  3. Product Portfolio Management: An Important Business Strategy

    Directory of Open Access Journals (Sweden)

    Doorasamy Mishelle

    2015-06-01

    Full Text Available The aim of this article is to provide reader with a comprehensive insight on the theories, empirical findings and models of Product Portfolio Management (PPM during new product development. This article will allow for an in-depth theoretical approach on PPM and demonstrate to managers the importance of adopting PPM as business strategy during decision making. The objective of this paper is to present a literature review of models, theories, approaches and findings on the relationship between Product Portfolio Management and new product development. Relevant statistical trends, historical developments, published opinion of major writers in this field will be presented to provide concrete evidence of the problem being discussed.

  4. Alternatives: the right medicine for your portfolio?

    Science.gov (United States)

    Doody, Dennis

    2006-01-01

    Because they often play an active role in developing their portfolio companies' strategies, private capital investment managers can add significant value to companies in their portfolio. The relative inefficiency of private capital markets can give savvy investors an edge that they can not so easily gain in the more efficient public markets. Originally created as a means to reduce volatility, hedge funds should not be seen as the high-risk bets that they are widely perceived to be. Most hedge funds actually are concerned with protecting downside risk.

  5. Portfolio optimization using fuzzy linear programming

    Science.gov (United States)

    Pandit, Purnima K.

    2013-09-01

    Portfolio Optimization (PO) is a problem in Finance, in which investor tries to maximize return and minimize risk by carefully choosing different assets. Expected return and risk are the most important parameters with regard to optimal portfolios. In the simple form PO can be modeled as quadratic programming problem which can be put into equivalent linear form. PO problems with the fuzzy parameters can be solved as multi-objective fuzzy linear programming problem. In this paper we give the solution to such problems with an illustrative example.

  6. Portfolio Optimization in a Semi-Markov Modulated Market

    International Nuclear Information System (INIS)

    Ghosh, Mrinal K.; Goswami, Anindya; Kumar, Suresh K.

    2009-01-01

    We address a portfolio optimization problem in a semi-Markov modulated market. We study both the terminal expected utility optimization on finite time horizon and the risk-sensitive portfolio optimization on finite and infinite time horizon. We obtain optimal portfolios in relevant cases. A numerical procedure is also developed to compute the optimal expected terminal utility for finite horizon problem

  7. Household portfolios and risk taking over age and time

    NARCIS (Netherlands)

    Bucciol, A.; Miniaci, R.

    2011-01-01

    We exploit the US Survey of Consumer Finances (SCF) from 1998 to 2007 to provide new insights on the evolution of US households’ willingness to undertake portfolio risk. Specifically, we consider four alternative measures of portfolio risk, based on two definitions of portfolio - a narrow one,

  8. Guidelines for Good Evaluation Practice with the ACUMEN portfolio

    DEFF Research Database (Denmark)

    Wildgaard, Lorna Elizabeth

    2014-01-01

    This document gives guidelines for using the ACUMEN Portfolio to evaluate academic researchers. The ACUMEN Portfolio is a way for Portfolio owners to highlight their achievements and to present themselves in the most positive way. It supplements the traditional CV because it highlights key achiev...

  9. Validity of portfolio assessment: which qualities determine ratings?

    NARCIS (Netherlands)

    Driessen, E.W.; Overeem, K.; Tartwijk, J. van; Vleuten, C.P.M. van der; Muijtjens, A.M.M.

    2006-01-01

    The portfolio is becoming increasingly accepted as a valuable tool for learning and assessment. The validity of portfolio assessment, however, may suffer from bias due to irrelevant qualities, such as lay-out and writing style. We examined the possible effects of such qualities in a portfolio

  10. Portfolio Development in Teacher Education and Educational Leadership.

    Science.gov (United States)

    Biddle, James

    The Ohio Consortium for Portfolio Development was established in 1988 as an interinstitutional research effort to integrate portfolio development into teacher education. A subphase focused on portfolio use by entry year teachers in a metropolitan school system. Personnel at Wright State University, Central State University, and the University of…

  11. Mentoring portfolio use in undergraduate and postgraduate medical education

    NARCIS (Netherlands)

    Dekker, Hanke; Driessen, Erik; Ter Braak, Edith; Scheele, Fedde; Slaets, Joris; Van Der Molen, Thys; Cohen-Schotanus, Janke

    2009-01-01

    Aim: Mentoring is widely acknowledged as being crucial for portfolio learning. The aim of this study is to examine how mentoring portfolio use has been implemented in undergraduate and postgraduate settings. Method: The results of interviews with six key persons involved in setting up portfolio use

  12. Asset Attribution Stability and Portfolio Construction: An Educational Example

    Science.gov (United States)

    Chong, James T.; Jennings, William P.; Phillips, G. Michael

    2014-01-01

    This paper illustrates how a third statistic from asset pricing models, the R-squared statistic, may have information that can help in portfolio construction. Using a traditional CAPM model in comparison to an 18-factor Arbitrage Pricing Style Model, a portfolio separation test is conducted. Portfolio returns and risk metrics are compared using…

  13. Professionalism, Portfolios and the Development of School Leaders.

    Science.gov (United States)

    Wildy, Helen; Wallace, John

    1998-01-01

    Describes how two reforms--portfolio culture and teacher professionalism--converge in a systemwide program for school leaders' professional development. Investigates use of portfolios to help (Australian) principals, deputy principals, and department heads improve their performance and accountability. Participants used portfolios as evidence of…

  14. Selection of a portfolio of R & D projects

    NARCIS (Netherlands)

    Casault, Sébastien; Groen, Arend J.; Linton, J.D.; Linton, Jonathan; Link, A.N.; Vonortas, N.S.

    2013-01-01

    While portfolios of research are increasingly discussed, a portfolio perspective is infrequently taken when selecting two or more projects. Consequently, this chapter considers the current state of knowledge in project and portfolio selection, identifies why we can and cannot apply knowledge from

  15. On the economic risk capital of portfolio insurance

    Directory of Open Access Journals (Sweden)

    Werner Hürlimann

    2004-09-01

    Full Text Available A formula for the conditional value-at-risk of classical portfolio insurance is derived and shown to be constant for sufficiently small loss probabilities. As illustrations, we discuss portfolio insurance for an equity market index using empirical data, and analyze the more general multivariate situation of a portfolio of risky assets.

  16. The current account as a dynamic portfolio choice problem

    OpenAIRE

    Didier, Tatiana; Lowenkron, Alexandre

    2009-01-01

    The current account can be understood as the outcome of investment decisions made by domestic and foreign investors. These decisions can be decomposed into a portfolio rebalancing and a portfolio growth component. This paper provides empirical evidence of the importance of portfolio rebalancing for the dynamics of the current account. The authors evaluate the predictions of a partial-equil...

  17. A Mentor-Based Portfolio Program to Evaluate Pharmacy Students’ Self-Assessment Skills

    Science.gov (United States)

    Kalata, Lindsay R.

    2013-01-01

    Objective. To evaluate pharmacy students' self-assessment skills with an electronic portfolio program using mentor evaluators. Design. First-year (P1) and second-year (P2) pharmacy students used online portfolios that required self-assessments of specific graded class assignments. Using a rubric, faculty and alumni mentors evaluated students' self-assessments and provided feedback. Assessment. Eighty-four P1 students, 74 P2 students, and 59 mentors participated in the portfolio program during 2010-2011. Both student groups performed well overall, with only a small number of resubmissions required. P1 students showed significant improvements across semesters for 2 of the self-assessment questions; P2 students' scores did not differ significantly. The P1 scores were significantly higher than P2 scores for 3 questions during spring 2011. Mentors and students had similar levels of agreement with the extent to which students put forth their best effort on the self-assessments. Conclusion. An electronic portfolio using mentors based inside and outside the school provided students with many opportunities to practice their self-assessment skills. This system represents a useful method of incorporating self-assessments into the curriculum that allows for feedback to be provided to the students. PMID:23716749

  18. A mentor-based portfolio program to evaluate pharmacy students' self-assessment skills.

    Science.gov (United States)

    Kalata, Lindsay R; Abate, Marie A

    2013-05-13

    Objective. To evaluate pharmacy students' self-assessment skills with an electronic portfolio program using mentor evaluators. Design. First-year (P1) and second-year (P2) pharmacy students used online portfolios that required self-assessments of specific graded class assignments. Using a rubric, faculty and alumni mentors evaluated students' self-assessments and provided feedback. Assessment. Eighty-four P1 students, 74 P2 students, and 59 mentors participated in the portfolio program during 2010-2011. Both student groups performed well overall, with only a small number of resubmissions required. P1 students showed significant improvements across semesters for 2 of the self-assessment questions; P2 students' scores did not differ significantly. The P1 scores were significantly higher than P2 scores for 3 questions during spring 2011. Mentors and students had similar levels of agreement with the extent to which students put forth their best effort on the self-assessments. Conclusion. An electronic portfolio using mentors based inside and outside the school provided students with many opportunities to practice their self-assessment skills. This system represents a useful method of incorporating self-assessments into the curriculum that allows for feedback to be provided to the students.

  19. Portfolios dominating indices: Optimization with second-order stochastic dominance constraints vs. minimum and mean variance portfolios

    OpenAIRE

    Keçeci, Neslihan Fidan; Kuzmenko, Viktor; Uryasev, Stan

    2016-01-01

    The paper compares portfolio optimization with the Second-Order Stochastic Dominance (SSD) constraints with mean-variance and minimum variance portfolio optimization. As a distribution-free decision rule, stochastic dominance takes into account the entire distribution of return rather than some specific characteristic, such as variance. The paper is focused on practical applications of the portfolio optimization and uses the Portfolio Safeguard (PSG) package, which has precoded modules for op...

  20. Portfolios Dominating Indices: Optimization with Second-Order Stochastic Dominance Constraints vs. Minimum and Mean Variance Portfolios

    OpenAIRE

    Neslihan Fidan Keçeci; Viktor Kuzmenko; Stan Uryasev

    2016-01-01

    The paper compares portfolio optimization with the Second-Order Stochastic Dominance (SSD) constraints with mean-variance and minimum variance portfolio optimization. As a distribution-free decision rule, stochastic dominance takes into account the entire distribution of return rather than some specific characteristic, such as variance. The paper is focused on practical applications of the portfolio optimization and uses the Portfolio Safeguard (PSG) package, which has precoded modules for op...

  1. The Development of E-Portfolio Evaluation Criteria and Application to the Blackboard LMS E-Portfolio

    Science.gov (United States)

    McKenna, Gary F.; Stansfield, Mark H.

    2012-01-01

    The purpose of this paper is to develop e-portfolio evaluation criteria which will be used to review the Blackboard LMS e-portfolio being used at one Higher Education (HE) institution in the UK as evaluation criteria for reviewing e-portfolio provision does not exist in the literature. The approach taken was to initiate a wide literature search…

  2. Teaching and Assessing Academic Writing via the Portfolio: Benefits for Learners of English as an Additional Language

    Science.gov (United States)

    Romova, Zina; Andrew, Martin

    2011-01-01

    This paper examines the use of portfolios as pedagogical tools for developing academic writing. In particular, it considers the value of multi-drafting, where learners reflect on the learning of a text type as well as focusing on micro and macro aspects. The paper outlines a situated pedagogical approach, where students come to understand their…

  3. The Effect of Exit Strategy on Optimal Portfolio Selection with Birandom Returns

    OpenAIRE

    Cao, Guohua; Shan, Dan

    2013-01-01

    The aims of this paper are to use a birandom variable to denote the stock return selected by some recurring technical patterns and to study the effect of exit strategy on optimal portfolio selection with birandom returns. Firstly, we propose a new method to estimate the stock return and use birandom distribution to denote the final stock return which can reflect the features of technical patterns and investors' heterogeneity simultaneously; secondly, we build a birandom safety-first model and...

  4. Decision Support for Retirement Portfolio Management: Overcoming Myopic Loss Aversion via Technology Design

    OpenAIRE

    Clayton Arlen Looney; Andrew M. Hardin

    2009-01-01

    As firms continue to abandon pensions in favor of employee-managed retirement plans, tremendous demands are being placed on the decision-making proficiency of future retirees. As reflected in the equity premium puzzle, individual investors tend to hold overly conservative portfolios that provide meager payoffs over time. Consequently, there is growing concern that the vast majority of retirement accounts might be insufficiently funded when employees reach retirement. Given that most retiremen...

  5. Electron dynamics in films made of transition metal nanograins embedded in SiO[sub 2]: Infrared reflectivity and nanoplasma infrared resonance

    KAUST Repository

    Massa, Néstor E.

    2009-06-04

    We report on near normal infrared reflectivityspectra of ∼550 nm thick films made of cosputtered transition metal nanograins and SiO2 in a wide range of metal fractions. Co0.85(SiO2)0.15,with conductivity well above the percolation threshold has a frequency and temperature behavior according to what it is find in conductingmetal oxides. The electron scattering rate displays a unique relaxation time characteristic of single type of carriers experiencing strong electron-phonon interactions. Using small polaron fits we identify those phonons as glass vibrational modes. Ni0.61(SiO2)0.39, with a metal fraction closer to the percolation threshold, undergoes a metal-nonmetal transition at ∼77 K. Here, as it is suggested by the scattering rate nearly quadratic dependence, we broadly identify two relaxation times (two carrier contributions) associated to a Drude mode and a midinfrared overdamped band, respectively. Disorder induced, the midinfrared contribution drives the phase transition by thermal electron localization. Co0.51(SiO2)0.49 has the reflectivity of an insulator with a distinctive band at ∼1450 cm−1 originating in electron promotion, localization, and defect induced polaron formation. Angle dependent oblique reflectivity of globally insulating Co0.38(SiO2)0.62, Fe0.34(SiO2)0.66, and Ni0.28(SiO2)0.72, reveals a remarkable resonance at that band threshold. We understand this as due to the excitation by normal to the film electric fields of defect localized electrons in the metallic nanoparticles. At higher oblique angles, this localized nanoplasma couples to SiO2 longitudinal optical Berreman phonons resulting in band peak softening reminiscent to the phonon behavior undergoing strong electron-phonon interactions. Singular to a globally insulating phase, we believe that this resonance might be a useful tool for tracking metal-insulator phase transitions in inhomogeneous materials.

  6. Both gas chromatography and an electronic nose reflect chemical polymorphism of juniper shrubs browsed or avoided by sheep.

    Science.gov (United States)

    Markó, Gábor; Novák, Ildikó; Bernáth, Jeno; Altbäcker, Vilmos

    2011-07-01

    Chemical polymorphism may contribute to variation in browsing damage by mammalian herbivores. Earlier, we demonstrated that essential oil concentration in juniper, Juniperus communis, was negatively associated with herbivore browsing. The aim of the present study was to characterize the volatile chemical composition of browsed and non-browsed J. communis. By using either gas chromatography with flame ionization detection (GC-FID) or an electronic nose device, we could separate sheep-browsed or non-browsed juniper shrubs by their essential oil pattern and complex odor matrix. The main components of the essential oil from J. communis were monoterpenes. We distinguished three chemotypes, dominated either by α-pinene, sabinene, or δ-3-carene. Shrubs belonging to the α-pinene- or sabinene-dominated groups were browsed, whereas all individuals with the δ-3-carene chemotype were unused by the local herbivores. The electronic nose also separated the browsed and non-browsed shrubs indicating that their odor matrix could guide sheep browsing. Responses of sheep could integrate the post-ingestive effects of plant secondary metabolites with sensory experience that stems from odor-phytotoxin interactions. Chemotype diversity could increase the survival rate in the present population of J. communis as certain shrubs could benefit from relatively better chemical protection against the herbivores.

  7. Performance of finite order distribution-generated universal portfolios

    Science.gov (United States)

    Pang, Sook Theng; Liew, How Hui; Chang, Yun Fah

    2017-04-01

    A Constant Rebalanced Portfolio (CRP) is an investment strategy which reinvests by redistributing wealth equally among a set of stocks. The empirical performance of the distribution-generated universal portfolio strategies are analysed experimentally concerning 10 higher volume stocks from different categories in Kuala Lumpur Stock Exchange. The time interval of study is from January 2000 to December 2015, which includes the credit crisis from September 2008 to March 2009. The performance of the finite-order universal portfolio strategies has been shown to be better than Constant Rebalanced Portfolio with some selected parameters of proposed universal portfolios.

  8. Portfolios of adaptation investments in water management

    NARCIS (Netherlands)

    Aerts, Jeroen C.J.H.; Botzen, Wouter; Werners, Saskia E.

    2015-01-01

    This study explores how Modern Portfolio Theory (MPT) can guide investment decisions in integrated water resources management (IWRM) and climate change adaptation under uncertainty. The objectives of the paper are to: (i) explain the concept of diversification to reduce risk, as formulated in

  9. Robust Utility Maximization Under Convex Portfolio Constraints

    International Nuclear Information System (INIS)

    Matoussi, Anis; Mezghani, Hanen; Mnif, Mohamed

    2015-01-01

    We study a robust maximization problem from terminal wealth and consumption under a convex constraints on the portfolio. We state the existence and the uniqueness of the consumption–investment strategy by studying the associated quadratic backward stochastic differential equation. We characterize the optimal control by using the duality method and deriving a dynamic maximum principle

  10. A Dynamic Programming Approach to Constrained Portfolios

    DEFF Research Database (Denmark)

    Kraft, Holger; Steffensen, Mogens

    2013-01-01

    This paper studies constrained portfolio problems that may involve constraints on the probability or the expected size of a shortfall of wealth or consumption. Our first contribution is that we solve the problems by dynamic programming, which is in contrast to the existing literature that applies...

  11. Machine-based mapping of innovation portfolios

    NARCIS (Netherlands)

    de Visser, Matthias; Miao, Shengfa; Englebienne, Gwenn; Sools, Anna Maria; Visscher, Klaasjan

    2017-01-01

    Machine learning techniques show a great promise for improving innovation portfolio management. In this paper we experiment with different methods to classify innovation projects of a high-tech firm as either explorative or exploitative, and compare the results with a manual, theory-based mapping of

  12. Assessment and Planning Using Portfolio Analysis

    Science.gov (United States)

    Roberts, Laura B.

    2010-01-01

    Portfolio analysis is a simple yet powerful management tool. Programs and activities are placed on a grid with mission along one axis and financial return on the other. The four boxes of the grid (low mission, low return; high mission, low return; high return, low mission; high return, high mission) help managers identify which programs might be…

  13. PORTFOLIO OPTIMIZATION ON CROATIAN CAPITAL MARKET

    Directory of Open Access Journals (Sweden)

    Sinisa Bogdan

    2013-12-01

    Full Text Available Purpose of this paper was to research portfolio optimization problem on Croatian capital market using Markowitz theory. Research systematically investigated the selection of securities, and defined the importance of using fundamental analysis when selecting the best combination of securities. Since fundamental analysis involves a large number of indicators, this paper selected key indicators that enable a complete and quick securities review on the market. This paper clarifies diversification effect and influence of the correlation coefficient on diversification. Two basic types of assets (stocks and cash funds have been chosen to build the optimal portfolio. Cash funds were selected because they represent a form of risk-free investment, while stocks were chosen because of the high level of return which they achieve. At the end of paper, optimal portfolio was calculated with an excellent yield of 1.82% and deviation of 5.77% on a monthly basis which corresponds to the minimum deviation of the selected stocks. Calculated optimal portfolio achieves better expected value than investing in stock index CROBEX, which for the same period achieves the expected result of -0.02%.

  14. Portfolio selection theory and wildlife management

    African Journals Online (AJOL)

    Theron and Van den Honert (2003) dealt with issues of risk and return in an agricultural context. ... By repeatedly solving (1) with different specified values of R an efficient frontier of portfolio .... the built–in solver of Microsoft® Excel [2].

  15. Equity Portfolio Management Using Option Price Information

    DEFF Research Database (Denmark)

    Christoffersen, Peter; Pan, Xuhui (Nick)

    We survey the recent academic literature that uses option-implied information to construct equity portfolios. Studies show that equity managers can earn a positive alpha by using information in individual equity options, by using stocks' exposure to information in market index options, and by usi...

  16. Currency Hedging for International Stock Portfolios

    NARCIS (Netherlands)

    F.A. de Roon (Frans); T.E. Nijman (Theo); B.J.M. Werker

    2000-01-01

    textabstractThis paper tests whether hedging currency risk improves the performance of international stock portfolios. We use a generalized performance measure which allows for investor-dependencies such as different utility functions and the presence of nontraded risks. In addition we show that an

  17. Digital portfolio og peer to peer feedback

    DEFF Research Database (Denmark)

    Jacobsen, Ditte; Bahrenscheer, Jesper Glarborg

    2017-01-01

    studerende og øget transfer mellem teori og praksis. Artiklen tager afsæt i erfaringerne fra udvikling, anvendelse og evaluering af den digitale portfolio og peer to peer feedback. Portfolien er digital og tilknyttet Metropols Learning Management System. De studerende uploader individuelt ugentligt deres...

  18. Portfolio selection using genetic algorithms | Yahaya | International ...

    African Journals Online (AJOL)

    In this paper, one of the nature-inspired evolutionary algorithms – a Genetic Algorithms (GA) was used in solving the portfolio selection problem (PSP). Based on a real dataset from a popular stock market, the performance of the algorithm in relation to those obtained from one of the popular quadratic programming (QP) ...

  19. Portfolio optimization using median-variance approach

    Science.gov (United States)

    Wan Mohd, Wan Rosanisah; Mohamad, Daud; Mohamed, Zulkifli

    2013-04-01

    Optimization models have been applied in many decision-making problems particularly in portfolio selection. Since the introduction of Markowitz's theory of portfolio selection, various approaches based on mathematical programming have been introduced such as mean-variance, mean-absolute deviation, mean-variance-skewness and conditional value-at-risk (CVaR) mainly to maximize return and minimize risk. However most of the approaches assume that the distribution of data is normal and this is not generally true. As an alternative, in this paper, we employ the median-variance approach to improve the portfolio optimization. This approach has successfully catered both types of normal and non-normal distribution of data. With this actual representation, we analyze and compare the rate of return and risk between the mean-variance and the median-variance based portfolio which consist of 30 stocks from Bursa Malaysia. The results in this study show that the median-variance approach is capable to produce a lower risk for each return earning as compared to the mean-variance approach.

  20. Information Content of Mutual Fund Portfolio Disclosure

    NARCIS (Netherlands)

    Y. Wang (Yu)

    2011-01-01

    textabstractAcademic financial economists have been keenly interested in the value of active portfolio management since the seminal paper of Jensen (1968). This book examines the information advantages that active mutual fund managers attain in financial markets through an analysis of disclosed fund

  1. A diversified portfolio model of adaptability.

    Science.gov (United States)

    Chandra, Siddharth; Leong, Frederick T L

    2016-12-01

    A new model of adaptability, the diversified portfolio model (DPM) of adaptability, is introduced. In the 1950s, Markowitz developed the financial portfolio model by demonstrating that investors could optimize the ratio of risk and return on their portfolios through risk diversification. The DPM integrates attractive features of a variety of models of adaptability, including Linville's self-complexity model, the risk and resilience model, and Bandura's social cognitive theory. The DPM draws on the concept of portfolio diversification, positing that diversified investment in multiple life experiences, life roles, and relationships promotes positive adaptation to life's challenges. The DPM provides a new integrative model of adaptability across the biopsychosocial levels of functioning. More importantly, the DPM addresses a gap in the literature by illuminating the antecedents of adaptive processes studied in a broad array of psychological models. The DPM is described in relation to the biopsychosocial model and propositions are offered regarding its utility in increasing adaptiveness. Recommendations for future research are also offered. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  2. How patient-selected colors for removable appliances are reflected in electronically tracked compliance (wear times and wear behavior).

    Science.gov (United States)

    Schott, Timm C; Menne, Dieter

    2018-03-27

    A broad spectrum of colors for removable appliances, intended to optimize acceptance of treatment and patient cooperation, have been available on the dental market for years. This is the first study to analyze how patient-selected colors are reflected in wear times and wear behavior of removable appliances. The study included 117 children (55 girls and 62 boys) who were treated with active removable plate or functional appliances. All patients were offered to choose from 11 different colors, which were pooled into six groups (black, blue, green, yellow, pink, red) for analysis, or to combine any two to four colors ("multicolored" group) for their appliances. All appliances featured a built-in microsensor (TheraMon; MC Technology, Hargelsberg, Austria) for objective wear-time tracking. Differences between wear times were analyzed using pairwise t tests and Tukey correction. The longest median wear times were recorded in the blue and green groups (≈11 h/d) and the shortest ones in the red and pink groups (≈9 h/d), but they were not significantly influenced by the patient-selected colors. The median wear times involved an age-related decrease by 0.56 h/y that was statistically significant ( P = .00005). No gender-specific patterns of wear behavior were observed. Patient-selected colors for removable appliances can presumably improve acceptance of treatment, but they are not associated with statistically significant improvements in wear time or wear behavior.

  3. Longitudinal evaluation of a pilot e-portfolio-based supervision programme for final year medical students: views of students, supervisors and new graduates.

    Science.gov (United States)

    Vance, Gillian H S; Burford, Bryan; Shapiro, Ethan; Price, Richard

    2017-08-22

    Little is known about how best to implement portfolio-based learning in medical school. We evaluated the introduction of a formative e-portfolio-based supervision pilot for final year medical students by seeking views of students, supervisors and graduates on use and educational effects. Students and supervisors were surveyed by questionnaire, with free text comments invited. Interviews were held with new graduates in their first Foundation Programme placement. Most students used the e-portfolio (54%) and met with their supervisor (62%) 'once or twice' only. Students had more negative views: 22% agreed that the pilot was beneficial, while most supervisors thought that e-portfolio (72%) and supervision (86%) were a 'good idea'. More students reported supervision meetings benefited learning (49%) and professional development (55%) than the e-portfolio did (16%; 28%). Only 47% of students felt 'prepared' for future educational processes, though graduates noted benefits for navigating and understanding e-portfolio building and supervision. Factors limiting engagement reflected 'burden', while supervision meetings and early experience of postgraduate processes offered educational value. Final year students have negative attitudes to a formative e-portfolio, though benefits for easing the educational transition are recognised by graduates. Measures to minimize time, repetition and redundancy of processes may encourage use. Engagement is influenced by the supervisor relationship and educational value may be best achieved by supporting supervisors to develop strategies to facilitate, and motivate self-directed learning processes in undergraduates.

  4. Digital Portfolio: a Strategy for Teachers Professional Development

    Directory of Open Access Journals (Sweden)

    R. Jans

    2008-03-01

    Full Text Available Teachers have to work with e-portfolio with theirstudents. This is a very demanding task because they neverwere educated with e-portfolio themselves. Therefore aEuropean Comenius project was submitted in 2005. In thisapproved project a whole week formation (april 2007 wasoffered to nineteen teachers from all over Europe. A yearlater they will meet again to see in what way the course hashad effects on their work with e-portfolio and students.Most interesting to notice was that the basic ICT-skills ofteachers are nowadays realized. However teachers are stillbusy with text and text-files. Rarely they uploadedmultimedia, like e.g. photo’s, video’s, youtube-movies, … intheir e-portfolio. The essential element of an e-portfolio, thepersonal and professional development plan, that forms thebackbone of the e-portfolio and offers the possibility tomake the e-portfolio an effective learning instrument wasunknown.

  5. Quantitative Portfolio Optimization Techniques Applied to the Brazilian Stock Market

    Directory of Open Access Journals (Sweden)

    André Alves Portela Santos

    2012-09-01

    Full Text Available In this paper we assess the out-of-sample performance of two alternative quantitative portfolio optimization techniques - mean-variance and minimum variance optimization – and compare their performance with respect to a naive 1/N (or equally-weighted portfolio and also to the market portfolio given by the Ibovespa. We focus on short selling-constrained portfolios and consider alternative estimators for the covariance matrices: sample covariance matrix, RiskMetrics, and three covariance estimators proposed by Ledoit and Wolf (2003, Ledoit and Wolf (2004a and Ledoit and Wolf (2004b. Taking into account alternative portfolio re-balancing frequencies, we compute out-of-sample performance statistics which indicate that the quantitative approaches delivered improved results in terms of lower portfolio volatility and better risk-adjusted returns. Moreover, the use of more sophisticated estimators for the covariance matrix generated optimal portfolios with lower turnover over time.

  6. Development of a portfolio of learning for postgraduate family medicine training in South Africa: a Delphi study.

    Science.gov (United States)

    Jenkins, Louis; Mash, Bob; Derese, Anselme

    2012-03-03

    that various types of evidence be included in the portfolio. The panel supported 26 of the 27 principles, but could not reach consensus on whether the portfolio should reflect on the relationship between the supervisor and registrar. A portfolio was developed and distributed to the eight departments of Family Medicine in South Africa, and the CMSA, to be further tested in implementation.

  7. Beating the market with small portfolios: Evidence from Brazil

    Directory of Open Access Journals (Sweden)

    André A.P. Santos

    2015-01-01

    Full Text Available Optimal portfolios with a restriction on the number of assets, also referred to as cardinality-constrained portfolios, have been receiving attention in the literature due to its popularity among market practitioners and retail investors. In most cases, however, the interest is in proposing efficient optimization methods to solve the problem, with little or no attention to the characteristics of the resulting portfolio such as risk-adjusted performance and turnover. We address this question by implementing a tractable reformulation of the cardinality-constrained version of the minimum variance portfolio. We analyze the out-of-sample performance of cardinality-constrained portfolios according to alternative criteria and check the robustness of the results for portfolios with alternative number of assets and under alternative re-balancing frequencies. Our empirical application for the Brazilian equities market shows that cardinality-constrained minimum variance portfolios with very few assets, e.g. 3 stocks, can deliver statistically lower portfolio risk and higher Sharpe ratios in comparison to the market index. Similar results are obtained for constrained portfolios with 5 and 10 assets and under daily, weekly, and monthly re-balancing frequencies. Our evidence indicates that it is possible to obtain better risk-adjusted performance with fewer securities in the portfolio by using an improved allocation scheme.

  8. A mathematical model for maximizing the value of phase 3 drug development portfolios incorporating budget constraints and risk.

    Science.gov (United States)

    Patel, Nitin R; Ankolekar, Suresh; Antonijevic, Zoran; Rajicic, Natasa

    2013-05-10

    We describe a value-driven approach to optimizing pharmaceutical portfolios. Our approach incorporates inputs from research and development and commercial functions by simultaneously addressing internal and external factors. This approach differentiates itself from current practices in that it recognizes the impact of study design parameters, sample size in particular, on the portfolio value. We develop an integer programming (IP) model as the basis for Bayesian decision analysis to optimize phase 3 development portfolios using expected net present value as the criterion. We show how this framework can be used to determine optimal sample sizes and trial schedules to maximize the value of a portfolio under budget constraints. We then illustrate the remarkable flexibility of the IP model to answer a variety of 'what-if' questions that reflect situations that arise in practice. We extend the IP model to a stochastic IP model to incorporate uncertainty in the availability of drugs from earlier development phases for phase 3 development in the future. We show how to use stochastic IP to re-optimize the portfolio development strategy over time as new information accumulates and budget changes occur. Copyright © 2013 John Wiley & Sons, Ltd.

  9. Electronic Portfolios and Learner Identity: An ePortfolio Case Study in Music and Writing

    Science.gov (United States)

    Bennett, Dawn; Rowley, Jennifer; Dunbar-Hall, Peter; Hitchcock, Matt; Blom, Diana

    2016-01-01

    Although the employability of graduates is of concern across further and higher education it is particularly problematic in the arts disciplines, from which few students transition to a traditional, full-time position. Arts graduates shape their work to meet personal and professional needs, and the successful negotiation of this type of career…

  10. Large portfolio risk management and optimal portfolio allocation with dynamic elliptical copulas

    Directory of Open Access Journals (Sweden)

    Jin Xisong

    2018-02-01

    Full Text Available Previous research has focused on the importance of modeling the multivariate distribution for optimal portfolio allocation and active risk management. However, existing dynamic models are not easily applied to high-dimensional problems due to the curse of dimensionality. In this paper, we extend the framework of the Dynamic Conditional Correlation/Equicorrelation and an extreme value approach into a series of Dynamic Conditional Elliptical Copulas. We investigate risk measures such as Value at Risk (VaR and Expected Shortfall (ES for passive portfolios and dynamic optimal portfolios using Mean-Variance and ES criteria for a sample of US stocks over a period of 10 years. Our results suggest that (1 Modeling the marginal distribution is important for dynamic high-dimensional multivariate models. (2 Neglecting the dynamic dependence in the copula causes over-aggressive risk management. (3 The DCC/DECO Gaussian copula and t-copula work very well for both VaR and ES. (4 Grouped t-copulas and t-copulas with dynamic degrees of freedom further match the fat tail. (5 Correctly modeling the dependence structure makes an improvement in portfolio optimization with respect to tail risk. (6 Models driven by multivariate t innovations with exogenously given degrees of freedom provide a flexible and applicable alternative for optimal portfolio risk management.

  11. The portfolio approach to competency-based assessment at the Cleveland Clinic Lerner College of Medicine.

    Science.gov (United States)

    Dannefer, Elaine F; Henson, Lindsey C

    2007-05-01

    Despite the rapid expansion of interest in competency-based assessment, few descriptions of assessment systems specifically designed for a competency-based curriculum have been reported. The purpose of this article is to describe the design of a portfolio approach to a comprehensive, competency-based assessment system that is fully integrated with the curriculum to foster an educational environment focused on learning. The educational design goal of the Cleveland Clinic Lerner College of Medicine of Case Western Reserve University was to create an integrated educational program-curriculum and instructional methods, student assessment processes, and learning environment-to prepare medical students for success in careers as physician investigators. The first class in the five-year program matriculated in 2004. To graduate, a student must demonstrate mastery of nine competencies: research, medical knowledge, communication, professionalism, clinical skills, clinical reasoning, health care systems, personal development, and reflective practice. The portfolio provides a tool for collecting and managing multiple types of assessment evidence from multiple contexts and sources within the curriculum to document competence and promote reflective practice skills. This article describes how the portfolio was developed to provide both formative and summative assessment of student achievement in relation to the program's nine competencies.

  12. Risk and utility in portfolio optimization

    Science.gov (United States)

    Cohen, Morrel H.; Natoli, Vincent D.

    2003-06-01

    Modern portfolio theory (MPT) addresses the problem of determining the optimum allocation of investment resources among a set of candidate assets. In the original mean-variance approach of Markowitz, volatility is taken as a proxy for risk, conflating uncertainty with risk. There have been many subsequent attempts to alleviate that weakness which, typically, combine utility and risk. We present here a modification of MPT based on the inclusion of separate risk and utility criteria. We define risk as the probability of failure to meet a pre-established investment goal. We define utility as the expectation of a utility function with positive and decreasing marginal value as a function of yield. The emphasis throughout is on long investment horizons for which risk-free assets do not exist. Analytic results are presented for a Gaussian probability distribution. Risk-utility relations are explored via empirical stock-price data, and an illustrative portfolio is optimized using the empirical data.

  13. USEFULNESS OF BOOTSTRAPPING IN PORTFOLIO MANAGEMENT

    Directory of Open Access Journals (Sweden)

    Boris Radovanov

    2012-12-01

    Full Text Available This paper contains a comparison of in-sample and out-of-sample performances between the resampled efficiency technique, patented by Richard Michaud and Robert Michaud (1999, and traditional Mean-Variance portfolio selection, presented by Harry Markowitz (1952. Based on the Monte Carlo simulation, data (samples generation process determines the algorithms by using both, parametric and nonparametric bootstrap techniques. Resampled efficiency provides the solution to use uncertain information without the need for constrains in portfolio optimization. Parametric bootstrap process starts with a parametric model specification, where we apply Capital Asset Pricing Model. After the estimation of specified model, the series of residuals are used for resampling process. On the other hand, nonparametric bootstrap divides series of price returns into the new series of blocks containing previous determined number of consecutive price returns. This procedure enables smooth resampling process and preserves the original structure of data series.

  14. MARKOV CHAIN PORTFOLIO LIQUIDITY OPTIMIZATION MODEL

    Directory of Open Access Journals (Sweden)

    Eder Oliveira Abensur

    2014-05-01

    Full Text Available The international financial crisis of September 2008 and May 2010 showed the importance of liquidity as an attribute to be considered in portfolio decisions. This study proposes an optimization model based on available public data, using Markov chain and Genetic Algorithms concepts as it considers the classic duality of risk versus return and incorporating liquidity costs. The work intends to propose a multi-criterion non-linear optimization model using liquidity based on a Markov chain. The non-linear model was tested using Genetic Algorithms with twenty five Brazilian stocks from 2007 to 2009. The results suggest that this is an innovative development methodology and useful for developing an efficient and realistic financial portfolio, as it considers many attributes such as risk, return and liquidity.

  15. Application of Performance Ratios in Portfolio Optimization

    Directory of Open Access Journals (Sweden)

    Aleš Kresta

    2015-01-01

    Full Text Available The cornerstone of modern portfolio theory was established by pioneer work of Harry Markowitz. Based on his mean-variance framework, Sharpe formulated his well-known Sharpe ratio aiming to measure the performance of mutual funds. The contemporary development in computer’s computational power allowed to apply more complex performance ratios, which take into account also higher moments of return probability distribution. Although these ratios were proposed to help the investors to improve the results of portfolio optimization, we empirically demonstrated in our paper that this may not necessarily be true. On the historical dataset of DJIA components we empirically showed that both Sharpe ratio and MAD ratio outperformed Rachev ratio. However, for Rachev ratio we assumed only one level of parameters value. Different set-ups of parameters may provide different results and thus further analysis is certainly required.

  16. Medicare Part D and Portfolio Choice.

    Science.gov (United States)

    Ayyagari, Padmaja; He, Daifeng

    2016-05-01

    This study evaluates the impact of medical expenditure risk on portfolio choice among the elderly. The risk of large medical expenditures can be substantial for elderly individuals and is only partially mitigated by access to health insurance. The presence of deductibles, copayments, and other cost-sharing mechanisms implies that medical spending risk can be viewed as an undiversifiable background risk. Economic theory suggests that increases in background risk reduce the optimal financial risk that an individual or household is willing to bear (Pratt and Zeckhauser 1987; Elmendorf and Kimball 2000). In this study, we evaluate this hypothesis by estimating the impact of the introduction of the Medicare Part D program, which significantly reduced prescription drug spending risk for seniors, on portfolio choice.

  17. Cosmic Visions Dark Energy: Small Projects Portfolio

    Energy Technology Data Exchange (ETDEWEB)

    Dawson, Kyle; Frieman, Josh; Heitmann, Katrin; Jain, Bhuvnesh; Kahn, Steve; Mandelbaum, Rachel; Perlmutter, Saul; Slosar, Anže

    2018-02-20

    Understanding cosmic acceleration is one of the key science drivers for astrophysics and high-energy physics in the coming decade (2014 P5 Report). With the Large Synoptic Survey Telescope (LSST) and the Dark Energy Spectroscopic Instrument (DESI) and other new facilities beginning operations soon, we are entering an exciting phase during which we expect an order of magnitude improvement in constraints on dark energy and the physics of the accelerating Universe. This is a key moment for a matching Small Projects portfolio that can (1) greatly enhance the science reach of these flagship projects, (2) have immediate scientific impact, and (3) lay the groundwork for the next stages of the Cosmic Frontier Dark Energy program. In this White Paper, we outline a balanced portfolio that can accomplish these goals through a combination of observational, experimental, and theory and simulation efforts.

  18. Phase inversion and frequency doubling of reflection high-energy electron diffraction intensity oscillations in the layer-by-layer growth of complex oxides

    Science.gov (United States)

    Mao, Zhangwen; Guo, Wei; Ji, Dianxiang; Zhang, Tianwei; Gu, Chenyi; Tang, Chao; Gu, Zhengbin; Nie*, Yuefeng; Pan, Xiaoqing

    In situ reflection high-energy electron diffraction (RHEED) and its intensity oscillations are extremely important for the growth of epitaxial thin films with atomic precision. The RHEED intensity oscillations of complex oxides are, however, rather complicated and a general model is still lacking. Here, we report the unusual phase inversion and frequency doubling of RHEED intensity oscillations observed in the layer-by-layer growth of SrTiO3 using oxide molecular beam epitaxy. In contacts to the common understanding that the maximum(minimum) intensity occurs at SrO(TiO2) termination, respectively, we found that both maximum or minimum intensities can occur at SrO, TiO2, or even incomplete terminations depending on the incident angle of the electron beam, which raises a fundamental question if one can rely on the RHEED intensity oscillations to precisely control the growth of thin films. A general model including surface roughness and termination dependent mean inner potential qualitatively explains the observed phenomena, and provides the answer to the question how to prepare atomically and chemically precise surface/interfaces using RHEED oscillations for complex oxides. We thank National Basic Research Program of China (No. 11574135, 2015CB654901) and the National Thousand-Young-Talents Program.

  19. Numerical simulation of the temperature, electron density, and electric field distributions near the ionospheric reflection height after turn-on of a powerful HF wave

    International Nuclear Information System (INIS)

    Muldrew, D.B.

    1986-01-01

    The time variation of the electron temperature profile in the ionosphere following turn-on of a powerful 1-s HF pulse is determined numerically from the energy balance equation. Using this and the equations of motion and continuity for a plasma, the effect of heating and the pondermotive force of a powerful HF wave on the electron density and electric field distributions are determined by numerical simulation. The temperature variation and ponderomotive force modify the density distribution, and this new density distribution, in turn, modifies the electric field distribution of the HF wave. The density deviations grow for a few hundred milliseconds after HF turn-on and then begin to fluctuate in time. At all heights the wave number of the density deviations is approximately twice the wave number of the HF wave. For electric fields near reflection of about 6.0 V/m, the electric field distribution becomes complicated, apparently depending on Bragg scattering of the HF wave from the density deviations. Density impulses propagate away (up and down) from electric field maxima, at the ion thermal velocity, at both turn-on and turn-off of the HF wave

  20. Parametric Immunization in Bond Portfolio Management

    OpenAIRE

    Bravo, Jorge; Fonseca, José

    2012-01-01

    In this paper, we evaluate the relative immunization performance of the multifactor parametric interest rate risk model based on the Nelson-Siegel-Svensson specification of the yield curve with that of standard benchmark investment strategies, using European Central Bank yield curve data in the period between January 3, 2005 and December 31, 2011. In addition, we examine the role of portfolio design in the success of immunization strategies, particularly the role of the maturit...