What Is the Relationship Between a Preclerkship Portfolio Review and Later Performance in Clerkships?

Science.gov (United States)

O'Brien, Celia Laird; Thomas, John X; Green, Marianne M

2018-01-01

Medical educators struggle to find effective ways to assess essential competencies such as communication, professionalism, and teamwork. Portfolio-based assessment provides one method of addressing this problem by allowing faculty reviewers to judge performance, as based on a longitudinal record of student behavior. At the Feinberg School of Medicine, the portfolio system measures behavioral competence using multiple assessments collected over time. This study examines whether a preclerkship portfolio review is a valid method of identifying problematic student behavior affecting later performance in clerkships. The authors divided students into two groups based on a summative preclerkship portfolio review in 2014: students who had concerning behavior in one or more competencies and students progressing satisfactorily. They compared how students in these groups later performed on two clerkship outcomes as of October 2015: final grades in required clerkships, and performance on a clerkship clinical composite score. They used Mann-Whitney tests and multiple linear regression to examine the relationship between portfolio review results and clerkship outcomes. They used USMLE Step 1 to control for knowledge acquisition. Students with concerning behavior preclerkship received significantly lower clerkship grades than students progressing satisfactorily (P = .002). They also scored significantly lower on the clinical composite score (P analysis indicated concerning behavior was associated with lower clinical composite scores, even after controlling for knowledge acquisition. The results show a preclerkship portfolio review can identify behaviors that impact clerkship performance. A comprehensive portfolio system is a valid way to measure behavioral competencies.

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.

The Impact of Portfolio Disclosure on Hedge Fund Performance, Fees and Flows

OpenAIRE

Zhen Shi

2011-01-01

This study investigates the impact of portfolio disclosure on hedge fund performance. Using a regression discontinuity design, I investigate the effect of the disclosure requirements that take effect when an investment company's assets exceed $100 million; when that occurs, a fund is required by the U.S. Securities and Exchange Commission to submit form 13F disclosing its portfolio holdings. Consistent with the argument that portfolio disclosure reveals 'trade secrets' and also raises front r...

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...

Business cycle effects on commercial bank loan portfolio performance in developing economies

Directory of Open Access Journals (Sweden)

Jack Glen

2011-04-01

Full Text Available This paper studies the effects of business cycles on the performance of commercial bank loan portfolios across major developing economies in the period 1996–2008. We measure loan performance via loan loss provisions (that is, recognized expenses related to expected losses in bank income statements. Our results indicate that while economic growth is the main driver of loan portfolio performance, interest rates have second-order effects. Furthermore, we find the relationship between loan loss provisions and economic growth to be highly non-linear only under extreme economic stress: GDP growth needs to decline by more than 6 percentage points (pp, in absolute terms in order to generate an increase in loan loss provisions equivalent to median emerging market bank profits; while a decline of more than 10 pp in growth implies significant capital losses, of at least 20 percent, for the median emerging market bank. In addition, we find higher loan loss provisions are associated with private sector leverage, poor loan portfolio quality, and lack of banking system penetration and capitalization.

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…

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,…

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.

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…

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.

Introducing Model Predictive Control for Improving Power Plant Portfolio Performance

DEFF Research Database (Denmark)

Edlund, Kristian Skjoldborg; Bendtsen, Jan Dimon; Børresen, Simon

2008-01-01

This paper introduces a model predictive control (MPC) approach for construction of a controller for balancing the power generation against consumption in a power system. The objective of the controller is to coordinate a portfolio consisting of multiple power plant units in the effort to perform...

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

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.

The effect of management team characteristics on performance and style extremity of mutual fund portfolios

Directory of Open Access Journals (Sweden)

Liu Qiong

2014-01-01

Full Text Available Purpose: Along with mutual funds’ scale and quantity expanding for our country, it is common for fund management companies hiring new managers or the original fund managers mobilizing from one to another. The high liquidity of fund managers makes different managers regroup to manage the funds that belong to the same fund management company in each fund year. The characteristics of these different management team will influence the fund performance, and also affect the earnings of the fund management company and portfolio investors. The purpose of this paper is as follows. First, evaluating the effect of management team characteristics on portfolio characteristics: risk, performance, and extremity. Second, testing the hypothesis that the ranking of mid-year performance have effect on investment style extremity and research what relationship exists between this phenomenon and management team characteristics in depth.Design/methodology/approach: On the analysis of the relationships between the management team characteristics and portfolio characteristics, a series of OLS regressions is run where the time series regression model (the factor model and cross-sectional regression are included based on using the STATA, EVIEWS and MATLAB. The validity and practicability of the model will be verified in the paper. All of the above are aimed at achieving portfolio optimization and realizing the maximization of the interests of fund management companies and investors.Findings: The main findings are as follows. Teams with more doctors or MBA (CPA and CFA hold more risky portfolios, while teams with long team tenure hold less. More members and large gender diversity have negative effect on performance, and the opposite is age diversity. Teams with more members and long tenure tend to hold less extreme style decisions, but age diversity is related to more. Besides, tournament hypothesis does exist in China investment funds industry especially when the

Market Performance and Accounting Information as the Reference of Stocks Portfolio Formation in Indonesia Stock Exchange

OpenAIRE

Pasaribu, Rowland Bismark Fernando

2009-01-01

This study aimed to a stock portfolio formed with composite of companies market (PER, PBV, ROE, EPS, PSR, and B/M, VaR) and accounting performance (ROE, and EPS) also their market capitalization in Indonesia Stock Exchange period 2003-2006. Some clarification need to achieved, such as: real difference among variabel refer to their market capitalization and influence of predictor to stock return. Hereinafter, the performance of selected portfolio were evaluated. The evaluation result conclude ...

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...

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.

Developing a framework for energy technology portfolio selection

Science.gov (United States)

Davoudpour, Hamid; Ashrafi, Maryam

2012-11-01

Today, the increased consumption of energy in world, in addition to the risk of quick exhaustion of fossil resources, has forced industrial firms and organizations to utilize energy technology portfolio management tools viewed both as a process of diversification of energy sources and optimal use of available energy sources. Furthermore, the rapid development of technologies, their increasing complexity and variety, and market dynamics have made the task of technology portfolio selection difficult. Considering high level of competitiveness, organizations need to strategically allocate their limited resources to the best subset of possible candidates. This paper presents the results of developing a mathematical model for energy technology portfolio selection at a R&D center maximizing support of the organization's strategy and values. The model balances the cost and benefit of the entire portfolio.

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.

Board Task Performance

DEFF Research Database (Denmark)

Minichilli, Alessandro; Zattoni, Alessandro; Nielsen, Sabina

2012-01-01

identify three board processes as micro-level determinants of board effectiveness. Specifically, we focus on effort norms, cognitive conflicts and the use of knowledge and skills as determinants of board control and advisory task performance. Further, we consider how two different institutional settings....... The findings show that: (i) Board processes have a larger potential than demographic variables to explain board task performance; (ii) board task performance differs significantly between boards operating in different contexts; and (iii) national context moderates the relationships between board processes...... and board task performance....

Introducing Model Predictive Control for Improving Power Plant Portfolio Performance

DEFF Research Database (Denmark)

Edlund, Kristian Skjoldborg; Bendtsen, Jan Dimon; Børresen, Simon

2008-01-01

This paper introduces a model predictive control (MPC) approach for construction of a controller for balancing the power generation against consumption in a power system. The objective of the controller is to coordinate a portfolio consisting of multiple power plant units in the effort to perform...... reference tracking and disturbance rejection in an economically optimal way. The performance function is chosen as a mixture of the `1-norm and a linear weighting to model the economics of the system. Simulations show a significant improvement of the performance of the MPC compared to the current...

Mandatory portfolio disclosure, stock liquidity, and mutual fund performance

OpenAIRE

Agarwal, Vikas; Mullally, Kevin Andrew; Tang, Yuehua; Yang, Baozhong

2014-01-01

We examine the impact of mandatory portfolio disclosure by mutual funds on stock liquidity and fund performance. We develop a model of informed trading with disclosure and test its predictions using the SEC regulation in May 2004 requiring more frequent disclosure. Stocks with higher fund ownership, especially those held by more informed funds or subject to greater information asymmetry, experience larger increases in liquidity after the regulation change. More informed funds, especially thos...

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.

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.

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...

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.

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.

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...

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".

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.

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

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…

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.

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.

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.

A Robust Statistics Approach to Minimum Variance Portfolio Optimization

Science.gov (United States)

Yang, Liusha; Couillet, Romain; McKay, Matthew R.

2015-12-01

We study the design of portfolios under a minimum risk criterion. The performance of the optimized portfolio relies on the accuracy of the estimated covariance matrix of the portfolio asset returns. For large portfolios, the number of available market returns is often of similar order to the number of assets, so that the sample covariance matrix performs poorly as a covariance estimator. Additionally, financial market data often contain outliers which, if not correctly handled, may further corrupt the covariance estimation. We address these shortcomings by studying the performance of a hybrid covariance matrix estimator based on Tyler's robust M-estimator and on Ledoit-Wolf's shrinkage estimator while assuming samples with heavy-tailed distribution. Employing recent results from random matrix theory, we develop a consistent estimator of (a scaled version of) the realized portfolio risk, which is minimized by optimizing online the shrinkage intensity. Our portfolio optimization method is shown via simulations to outperform existing methods both for synthetic and real market data.

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...

Coaching the Coach: A Program for Development of Faculty Portfolio Coaches.

Science.gov (United States)

Kopechek, Jack; Bardales, Cheryl; Lash, A Todd; Walker, Curtis; Pfeil, Sheryl; Ledford, Cynthia H

2017-01-01

Faculty coaching is recognized as an essential element for effective use of portfolios in undergraduate medical education, yet best practices for training these coaches are uncertain. New portfolio coaches participated in a multifaceted training program that included orienting modules, a 7.5-hr training workshop featuring analysis of reflective writing, an Observed Structured Teaching Exercise (OSTE), and subsequent longitudinal coaches' meetings for timely task training. Four desired coaching skills were emphasized in the initial training: creating a safe environment, explicitly using performance data, asking questions that elicit reflection, and guiding the student to develop future goals and plans. We collected and analyzed several outcomes: (a) coaches' self-assessment at key intervals, (b) open-ended written responses to three coaching vignettes, (c) video recordings of the OSTE, and (d) subsequent student evaluation of the coach. In an attempt to capture learning from the workshop, both the responses to written vignettes and the video-recorded encounters were coded for presence or absence of the four desired skills. Our portfolio and coaching program was instituted as part of a major undergraduate medical education reform. A new cohort of 25 coaches is enrolled with each matriculating student class, and each coach is assigned to work individually with 8-10 students, forming a coaching relationship that continues over 4 years. Coaches are compensated at 5% full-time equivalent. On coach self-assessment, the majority of coaches reported significant improvement in their perceived ability to assess a student's level of reflection, enhance reflection, use performance data, and guide a student to develop goals and plans. After two semesters, coach perception of improved abilities persisted. Students rated coaches as excellent (82%), reporting that coaches created safe environments (99%), promoted insight (92%), and aided in goal setting (97%). Written responses to

Promising high monetary rewards for future task performance increases intermediate task performance.

Directory of Open Access Journals (Sweden)

Claire M Zedelius

Full Text Available In everyday life contexts and work settings, monetary rewards are often contingent on future performance. Based on research showing that the anticipation of rewards causes improved task performance through enhanced task preparation, the present study tested the hypothesis that the promise of monetary rewards for future performance would not only increase future performance, but also performance on an unrewarded intermediate task. Participants performed an auditory Simon task in which they responded to two consecutive tones. While participants could earn high vs. low monetary rewards for fast responses to every second tone, their responses to the first tone were not rewarded. Moreover, we compared performance under conditions in which reward information could prompt strategic performance adjustments (i.e., when reward information was presented for a relatively long duration to conditions preventing strategic performance adjustments (i.e., when reward information was presented very briefly. Results showed that high (vs. low rewards sped up both rewarded and intermediate, unrewarded responses, and the effect was independent of the duration of reward presentation. Moreover, long presentation led to a speed-accuracy trade-off for both rewarded and unrewarded tones, whereas short presentation sped up responses to rewarded and unrewarded tones without this trade-off. These results suggest that high rewards for future performance boost intermediate performance due to enhanced task preparation, and they do so regardless whether people respond to rewards in a strategic or non-strategic manner.

Promising high monetary rewards for future task performance increases intermediate task performance.

Science.gov (United States)

Zedelius, Claire M; Veling, Harm; Bijleveld, Erik; Aarts, Henk

2012-01-01

In everyday life contexts and work settings, monetary rewards are often contingent on future performance. Based on research showing that the anticipation of rewards causes improved task performance through enhanced task preparation, the present study tested the hypothesis that the promise of monetary rewards for future performance would not only increase future performance, but also performance on an unrewarded intermediate task. Participants performed an auditory Simon task in which they responded to two consecutive tones. While participants could earn high vs. low monetary rewards for fast responses to every second tone, their responses to the first tone were not rewarded. Moreover, we compared performance under conditions in which reward information could prompt strategic performance adjustments (i.e., when reward information was presented for a relatively long duration) to conditions preventing strategic performance adjustments (i.e., when reward information was presented very briefly). Results showed that high (vs. low) rewards sped up both rewarded and intermediate, unrewarded responses, and the effect was independent of the duration of reward presentation. Moreover, long presentation led to a speed-accuracy trade-off for both rewarded and unrewarded tones, whereas short presentation sped up responses to rewarded and unrewarded tones without this trade-off. These results suggest that high rewards for future performance boost intermediate performance due to enhanced task preparation, and they do so regardless whether people respond to rewards in a strategic or non-strategic manner.

Performance analysis of portuguese equity mutual funds: indexing vs active portfolio management

OpenAIRE

Ribeiro, Alexandra João Santana

2011-01-01

Master in Finance The present thesis was done with the objective of analyzing the portfolio management strategies followed by managers of Portuguese Equity Funds, using the PSI Geral as the benchmark. Thus, the quarter returns and compositions of portfolio were used. The market timing ability and the variables that may have influenced tracking error (vs. PSI Geral) were also analyzed. The main conclusion was that just 1 fund managed to put successfully into practice the active portfolio...

Institutional Assessment and the Integrative Core Curriculum: Involving Students in the Development of an ePortfolio System

Science.gov (United States)

Silva, Mary Lourdes; Adams Delaney, Susan; Cochran, Jolene; Jackson, Ruth; Olivares, Cory

2015-01-01

The majority of research on the implementation of ePortfolios focuses on curriculum, faculty development, or student buy-in. When ePortfolio systems have been described in technical terms, the focus has been on the functionality, affordances, and limitations of ePortfolio systems (e.g., TaskStream, LiveText), free web tools (e.g., Google Docs),…

[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.

Vast Portfolio Selection with Gross-exposure Constraints().

Science.gov (United States)

Fan, Jianqing; Zhang, Jingjin; Yu, Ke

2012-01-01

We introduce the large portfolio selection using gross-exposure constraints. We show that with gross-exposure constraint the empirically selected optimal portfolios based on estimated covariance matrices have similar performance to the theoretical optimal ones and there is no error accumulation effect from estimation of vast covariance matrices. This gives theoretical justification to the empirical results in Jagannathan and Ma (2003). We also show that the no-short-sale portfolio can be improved by allowing some short positions. The applications to portfolio selection, tracking, and improvements are also addressed. The utility of our new approach is illustrated by simulation and empirical studies on the 100 Fama-French industrial portfolios and the 600 stocks randomly selected from Russell 3000.

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

Enhanced Portfolio Performance Using a Momentum Approach to Annual Rebalancing

OpenAIRE

Michael D. Mattei

2018-01-01

After diversification, periodic portfolio rebalancing has become one of the most widely practiced methods for reducing portfolio risk and enhancing returns. Most of the rebalancing strategies found in the literature are generally regarded as contrarian approaches to rebalancing. A recent article proposed a rebalancing approach that incorporates a momentum approach to rebalancing. The momentum approach had a better risk adjusted return than either the traditional approach or a Buy-and-Hold app...

Working Memory Training Improves Dual-Task Performance on Motor Tasks.

Science.gov (United States)

Kimura, Takehide; Kaneko, Fuminari; Nagahata, Keita; Shibata, Eriko; Aoki, Nobuhiro

2017-01-01

The authors investigated whether working memory training improves motor-motor dual-task performance consisted of upper and lower limb tasks. The upper limb task was a simple reaction task and the lower limb task was an isometric knee extension task. 45 participants (age = 21.8 ± 1.6 years) were classified into a working memory training group (WM-TRG), dual-task training group, or control group. The training duration was 2 weeks (15 min, 4 times/week). Our results indicated that working memory capacity increased significantly only in the WM-TRG. Dual-task performance improved in the WM-TRG and dual-task training group. Our study provides the novel insight that working memory training improves dual-task performance without specific training on the target motor task.

Computer-Related Task Performance

DEFF Research Database (Denmark)

Longstreet, Phil; Xiao, Xiao; Sarker, Saonee

2016-01-01

The existing information system (IS) literature has acknowledged computer self-efficacy (CSE) as an important factor contributing to enhancements in computer-related task performance. However, the empirical results of CSE on performance have not always been consistent, and increasing an individual......'s CSE is often a cumbersome process. Thus, we introduce the theoretical concept of self-prophecy (SP) and examine how this social influence strategy can be used to improve computer-related task performance. Two experiments are conducted to examine the influence of SP on task performance. Results show...... that SP and CSE interact to influence performance. Implications are then discussed in terms of organizations’ ability to increase performance....

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).

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.

Use of statistical indicators of profit accounting for formation of a product portfolio

Directory of Open Access Journals (Sweden)

Nesterova L.G.

2017-01-01

Full Text Available Article is related to perfection of product portfolio policy of the enterprise by formation of a product portfolio by means of using of statistics methods and mathematical criteria of the games theory. Such approach allows to decide many tasks of marketing at the enterprise, including to use results of marketing researches and demand and profit forecasting. As a result of the offered system of calculations of statistical indicators it is possible to receive a matrix of predicted risks and market growth for a concrete product portfolio, and also to estimate potential and market prospects of concrete commodity groups. It will form an optimal product portfolio for the specific market conditions.

Portfolio optimization by using linear programing models based on genetic algorithm

Science.gov (United States)

Sukono; Hidayat, Y.; Lesmana, E.; Putra, A. S.; Napitupulu, H.; Supian, S.

2018-01-01

In this paper, we discussed the investment portfolio optimization using linear programming model based on genetic algorithms. It is assumed that the portfolio risk is measured by absolute standard deviation, and each investor has a risk tolerance on the investment portfolio. To complete the investment portfolio optimization problem, the issue is arranged into a linear programming model. Furthermore, determination of the optimum solution for linear programming is done by using a genetic algorithm. As a numerical illustration, we analyze some of the stocks traded on the capital market in Indonesia. Based on the analysis, it is shown that the portfolio optimization performed by genetic algorithm approach produces more optimal efficient portfolio, compared to the portfolio optimization performed by a linear programming algorithm approach. Therefore, genetic algorithms can be considered as an alternative on determining the investment portfolio optimization, particularly using linear programming models.

Vast Portfolio Selection with Gross-exposure Constraints*

Science.gov (United States)

Fan, Jianqing; Zhang, Jingjin; Yu, Ke

2012-01-01

We introduce the large portfolio selection using gross-exposure constraints. We show that with gross-exposure constraint the empirically selected optimal portfolios based on estimated covariance matrices have similar performance to the theoretical optimal ones and there is no error accumulation effect from estimation of vast covariance matrices. This gives theoretical justification to the empirical results in Jagannathan and Ma (2003). We also show that the no-short-sale portfolio can be improved by allowing some short positions. The applications to portfolio selection, tracking, and improvements are also addressed. The utility of our new approach is illustrated by simulation and empirical studies on the 100 Fama-French industrial portfolios and the 600 stocks randomly selected from Russell 3000. PMID:23293404

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...

Evaluation of the probabilistic safety assessment portfolio for NSD. Plan of work

International Nuclear Information System (INIS)

Gould, J.

1999-01-01

The aim is to use the research portfolio evaluation protocol developed by HSL to evaluate the Probabilistic Safety Assessment (PSA) portfolio, both to draw conclusions about the PSA portfolio and as a pilot study to show the suitability of the evaluation protocol. The objectives of the work are: (1) To collect sufficient information to carry out a preliminary review of the portfolio; (2) o produce a plan of work detailing the time and costs to carry out a full evaluation of the PSA portfolio; (3) to evaluate the PSA portfolio of research; (4) to produce a report of the evaluation of the PSA portfolio; (5) if necessary, to make changes to the methodology in light of the experience gained in the evaluation of the PSA research portfolio. This report completes objectives 1 and 2. It details the plan of work for the evaluation of the PSA research portfolio. The plan has shown that the evaluation of the PSA research portfolio has many difficulties to overcome. It is suitable as a pilot study to show the suitability of the portfolio evaluation protocol and will provide valuable information that can be used to improve it. The evaluation of the PSA portfolio will require a considerable amount of time and effort to complete. The task analysis has shown it to be of the order of Pound Sterling 25k and to take two months to complete after this preliminary data collection. The plan to evaluate the PSA research portfolio detailed in this report should be carried out and the lessons learned by carrying out this pilot study should be used to improve the evaluation protocol

The type k universal portfolio generated by the f-divergence

Science.gov (United States)

Tan, Choon Peng; Seng, Kuang Kee

2017-11-01

The logarithm of the estimated next-day wealth return is approximated by k terms of its Taylor series. The resulting Type k universal portfolio generated by the f -divergence is obtained. An implicit form of the portfolio is also obtained by exploiting the mean-value theorem. An empirical study of the performance of the portfolio is focused on the Type 2 Helmbold universal portfolio. A few generalizations of the Helmbold universal portfolio have recently been studied, namely the reverse Helmbold and the parametric Helmbold portfolios. This new type of portfolio can be regarded a contribution to the inventory of Helmbold related universal portfolios. It is verified experimentally that an investor's wealth can be significantly increased by using the Type 2 Helmbold portfolio in investment.

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.

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

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.

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...

Extended Information Ratio for Portfolio Optimization Using Simulated Annealing with Constrained Neighborhood

Science.gov (United States)

Orito, Yukiko; Yamamoto, Hisashi; Tsujimura, Yasuhiro; Kambayashi, Yasushi

The portfolio optimizations are to determine the proportion-weighted combination in the portfolio in order to achieve investment targets. This optimization is one of the multi-dimensional combinatorial optimizations and it is difficult for the portfolio constructed in the past period to keep its performance in the future period. In order to keep the good performances of portfolios, we propose the extended information ratio as an objective function, using the information ratio, beta, prime beta, or correlation coefficient in this paper. We apply the simulated annealing (SA) to optimize the portfolio employing the proposed ratio. For the SA, we make the neighbor by the operation that changes the structure of the weights in the portfolio. In the numerical experiments, we show that our portfolios keep the good performances when the market trend of the future period becomes different from that of the past period.

Documenting Quality Improvement and Patient Safety Efforts: The Quality Portfolio. A Statement from the Academic Hospitalist Taskforce

OpenAIRE

Taylor, Benjamin B.; Parekh, Vikas; Estrada, Carlos A.; Schleyer, Anneliese; Sharpe, Bradley

2013-01-01

Physicians increasingly investigate, work, and teach to improve the quality of care and safety of care delivery. The Society of General Internal Medicine Academic Hospitalist Task Force sought to develop a practical tool, the quality portfolio, to systematically document quality and safety achievements. The quality portfolio was vetted with internal and external stakeholders including national leaders in academic medicine. The portfolio was refined for implementation to include an outlined fr...

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

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.

Fifteen years of portfolio assessment of dental hygiene student competency: lessons learned.

Science.gov (United States)

Gadbury-Amyot, Cynthia C; Bray, Kimberly Krust; Austin, Kylie J

2014-10-01

Adoption of portfolio assessment in the educational environment is gaining attention as a means to incorporate self-assessment into the curriculum and to use evidence to support learning outcomes and to demonstrate competency. Portfolios provide a medium for students to demonstrate and document their personal and professional growth across the curriculum. The purpose of this literature review is to discuss the drivers for portfolio education, the benefits to both students and program faculty/administrators, the barriers associated with portfolio use, and suggested solutions that have been determined through several years of "lessons learned." The University of Missouri Kansas City School of Dentistry, Division of Dental Hygiene department has been utilizing portfolio assessment for over 15 years and has collected data related to portfolio performance since 2001. Results from correlational statistics calculated on the 312 dental hygiene students that graduated from 2001 to 2013 demonstrate a positive and significant relationship between portfolio performance and overall GPA as well as portfolio performance and NBDHE scores. Copyright © 2014 The American Dental Hygienists’ Association.

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...

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.

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…

Pre-task music improves swimming performance.

Science.gov (United States)

Smirmaul, B P; Dos Santos, R V; Da Silva Neto, L V

2015-12-01

The purpose of this study was to investigate the effects of pre-task music on swimming performance and other psychological variables. A randomized counterbalanced within-subjects (experimental and control condition) design was employed. Eighteen regional level male swimmers performed two 200-m freestyle swimming time trials. Participants were exposed to either 5 minutes of self-selected music (pre-task music condition) or 5 minutes of silence (control condition) and, after 1 minute, performed the swimming task. Swimming time was significantly shorter (-1.44%) in the pre-task music condition. Listening to pre-task music increased motivation to perform the swimming task, while arousal remained unchanged. While fatigue increased after the swimming task in both conditions, vigor, ratings of perceived exertion and affective valence were unaltered. It is concluded, for the first time, that pre-task music improves swimming performance.

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...

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.

Wavelet evolutionary network for complex-constrained portfolio rebalancing

Science.gov (United States)

Suganya, N. C.; Vijayalakshmi Pai, G. A.

2012-07-01

Portfolio rebalancing problem deals with resetting the proportion of different assets in a portfolio with respect to changing market conditions. The constraints included in the portfolio rebalancing problem are basic, cardinality, bounding, class and proportional transaction cost. In this study, a new heuristic algorithm named wavelet evolutionary network (WEN) is proposed for the solution of complex-constrained portfolio rebalancing problem. Initially, the empirical covariance matrix, one of the key inputs to the problem, is estimated using the wavelet shrinkage denoising technique to obtain better optimal portfolios. Secondly, the complex cardinality constraint is eliminated using k-means cluster analysis. Finally, WEN strategy with logical procedures is employed to find the initial proportion of investment in portfolio of assets and also rebalance them after certain period. Experimental studies of WEN are undertaken on Bombay Stock Exchange, India (BSE200 index, period: July 2001-July 2006) and Tokyo Stock Exchange, Japan (Nikkei225 index, period: March 2002-March 2007) data sets. The result obtained using WEN is compared with the only existing counterpart named Hopfield evolutionary network (HEN) strategy and also verifies that WEN performs better than HEN. In addition, different performance metrics and data envelopment analysis are carried out to prove the robustness and efficiency of WEN over HEN strategy.

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.

Performance Enhancements Under Dual-task Conditions

Science.gov (United States)

Kramer, A. F.; Wickens, C. D.; Donchin, E.

1984-01-01

Research on dual-task performance has been concerned with delineating the antecedent conditions which lead to dual-task decrements. Capacity models of attention, which propose that a hypothetical resource structure underlies performance, have been employed as predictive devices. These models predict that tasks which require different processing resources can be more successfully time shared than tasks which require common resources. The conditions under which such dual-task integrality can be fostered were assessed in a study in which three factors likely to influence the integrality between tasks were manipulated: inter-task redundancy, the physical proximity of tasks and the task relevant objects. Twelve subjects participated in three experimental sessions in which they performed both single and dual-tasks. The primary task was a pursuit step tracking task. The secondary tasks required the discrimination between different intensities or different spatial positions of a stimulus. The results are discussed in terms of a model of dual-task integrality.

Transparency in the ePortfolio Creation Process

Science.gov (United States)

Jones, Stephanie A.; Downs, Elizabeth; Jenkins, Stephen J.

2015-01-01

This paper presents the findings of a study examining the effect of transparency on the ePortfolio creation process. The purpose of the study was to examine whether increased awareness of other students' ePortfolios through the implementation of transparency and peer review would positively affect the quality of performance of school library media…

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...

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...

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.

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

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.

A Study on Product Innovation Portfolio and Customer Value Creation: Bridging Entrepreneurial Risk-Taking Orientation and Marketing Performance

Directory of Open Access Journals (Sweden)

Maklon Felipus Killa

2017-12-01

Full Text Available The aim of this study is to investigate the role of product innovation portfolio and customer value creation in bridg- ing the gap between entrepreneurial risk-taking orientation and marketing performance. Wood crafts companies located in Bandung, Yogyakarta, and Solo, all of which have been regarded as Indonesia’s creative cities, were used as samples. Sampling was done by using a combination of purposive and convenience sampling. The total data used for the analysis was from 172 respondents who filled in direct questionnaires. This research used Structural Equation Modeling (SEM with AMOS v.20 program for data analysis. The results showed that product innovation portfolio serves as mediator in the relationship between entrepreneurial risk-taking orientation and marketing performance. Furthermore, the results also found that customer value creation has a positive effect on marketing performance.

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.

Characteristics of Omega-Optimized Portfolios at Different Levels of Threshold Returns

Directory of Open Access Journals (Sweden)

Renaldas Vilkancas

2014-12-01

Full Text Available There is little literature considering effects that the loss-gain threshold used for dividing good and bad outcomes by all downside (upside risk measures has on portfolio optimization and performance. The purpose of this study is to assess the performance of portfolios optimized with respect to the Omega function developed by Keating and Shadwick at different levels of the threshold returns. The most common choices of the threshold values used in various Omega studies cover the risk-free rate and the average market return or simply a zero return, even though the inventors of this measure for risk warn that “using the values of the Omega function at particular points can be critically misleading” and that “only the entire Omega function contains information on distribution”. The obtained results demonstrate the importance of the selected values of the threshold return on portfolio performance – higher levels of the threshold lead to an increase in portfolio returns, albeit at the expense of a higher risk. In fact, within a certain threshold interval, Omega-optimized portfolios achieved the highest net return, compared with all other strategies for portfolio optimization using three different test datasets. However, beyond a certain limit, high threshold values will actually start hurting portfolio performance while meta-heuristic optimizers typically are able to produce a solution at any level of the threshold, and the obtained results would most likely be financially meaningless.

PORTFOLIO COMPOSITION WITH MINIMUM VARIANCE: COMPARISON WITH MARKET BENCHMARKS

Directory of Open Access Journals (Sweden)

Daniel Menezes Cavalcante

2016-07-01

Full Text Available Portfolio optimization strategies are advocated as being able to allow the composition of stocks portfolios that provide returns above market benchmarks. This study aims to determine whether, in fact, portfolios based on the minimum variance strategy, optimized by the Modern Portfolio Theory, are able to achieve earnings above market benchmarks in Brazil. Time series of 36 securities traded on the BM&FBOVESPA have been analyzed in a long period of time (1999-2012, with sample windows of 12, 36, 60 and 120 monthly observations. The results indicated that the minimum variance portfolio performance is superior to market benchmarks (CDI and IBOVESPA in terms of return and risk-adjusted return, especially in medium and long-term investment horizons.

Venture capital and efficiency of portfolio companies

Directory of Open Access Journals (Sweden)

A. Thillai Rajan

2010-12-01

Full Text Available Venture Capital (VC has emerged as the dominant source of finance for entrepreneurial and early stage businesses, and the Indian VC industry in particular has clocked the fastest growth rate globally. Academic literature reveals that VC funded companies show superior performance to non VC funded companies. However, given that venture capitalists (VCs select and fund only the best companies, how much credit can they take for the performance of the companies they fund? Do the inherent characteristics of the firm result in superior performance or do VCs contribute to the performance of the portfolio company after they have entered the firm? A panel that comprised VCs, an entrepreneur and an academic debated these and other research questions on the inter-relationships between VC funding and portfolio firm performance. Most empirical literature indicates that the value addition effect dominates the selection effect in accounting for the superior performance of VC funded companies. The panel discussion indicates that the context as well as the experience of the General Partners in the VC firms can influence the way VCs contribute to the efficiency of their portfolio companies.

Implementing Portfolio Assessment in Lower-Secondary School

Directory of Open Access Journals (Sweden)

Anna Czura

2013-05-01

Full Text Available Since alternative assessment embraces highly authentic tasks consistent with classroom goals and instruction, its implementation in the language classroom is believed to promote collaboration with peers, transfer responsibility to the learners and, consequently, foster learner autonomy. This paper presents the results of a research study aiming to determine whether portfolio assessment contributes to the development of autonomy in adolescent learners. In order to collect the data, qualitative and quantative methods of research were applied. The research results reveal that the implementation of portfolio assessment failed to affect the overall level of learner autonomy. Introducing one selected pedagogical procedure does not suffice to foster learner autonomy. Teachers need to be ready to pass a portion of their authority to the learners, who, in turn, need to know how to use the new privileges judiciously.

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...

Building Personal Brands with Digital Storytelling ePortfolios

Science.gov (United States)

Jones, Beata; Leverenz, Carrie

2017-01-01

Antoine de Saint-Exupery said, "If you want to build a ship, don't drum up people to collect wood and don't assign them tasks and work, but rather teach them to long for the endless immensity of the sea." This article presents a pedagogical approach for framing a digital-identity-enhancing ePortfolio that maximizes student engagement and…

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...

Applying the partitioned multiobjective risk method (PMRM) to portfolio selection.

Science.gov (United States)

Reyes Santos, Joost; Haimes, Yacov Y

2004-06-01

The analysis of risk-return tradeoffs and their practical applications to portfolio analysis paved the way for Modern Portfolio Theory (MPT), which won Harry Markowitz a 1992 Nobel Prize in Economics. A typical approach in measuring a portfolio's expected return is based on the historical returns of the assets included in a portfolio. On the other hand, portfolio risk is usually measured using volatility, which is derived from the historical variance-covariance relationships among the portfolio assets. This article focuses on assessing portfolio risk, with emphasis on extreme risks. To date, volatility is a major measure of risk owing to its simplicity and validity for relatively small asset price fluctuations. Volatility is a justified measure for stable market performance, but it is weak in addressing portfolio risk under aberrant market fluctuations. Extreme market crashes such as that on October 19, 1987 ("Black Monday") and catastrophic events such as the terrorist attack of September 11, 2001 that led to a four-day suspension of trading on the New York Stock Exchange (NYSE) are a few examples where measuring risk via volatility can lead to inaccurate predictions. Thus, there is a need for a more robust metric of risk. By invoking the principles of the extreme-risk-analysis method through the partitioned multiobjective risk method (PMRM), this article contributes to the modeling of extreme risks in portfolio performance. A measure of an extreme portfolio risk, denoted by f(4), is defined as the conditional expectation for a lower-tail region of the distribution of the possible portfolio returns. This article presents a multiobjective problem formulation consisting of optimizing expected return and f(4), whose solution is determined using Evolver-a software that implements a genetic algorithm. Under business-as-usual market scenarios, the results of the proposed PMRM portfolio selection model are found to be compatible with those of the volatility-based model

Strategic Context of Project Portfolio Management

Directory of Open Access Journals (Sweden)

Nedka Nikolova

2016-06-01

Full Text Available In 2014 Bulgaria entered its second programming period (2014-2020 which opened a new stage in the development of project management in our country. Project-oriented companies are entering a new stage in which based on experience and increased design capacity they will develop their potential and will accelerate growth. This poses new challenges for science and business to identify strategic opportunities and formulation of project objectives, programs and portfolios of projects that will increase the competitive potential of companies and the economy as a whole. This article is an expression of the shared responsibility of science to develop the scientific front to solve methodologically difficult and practically new tasks that are derived from the needs to increase the competitive potential of the business-based project approach. The main objective of this study is based on the systematization of the results of theoretical research and development of methodology of Project Portfolio Management to explore the opportunities for its application in Bulgarian industrial companies.

Portfolio optimisation for hydropower producers that balances riverine ecosystem protection and producer needs

Science.gov (United States)

Yin, X. A.; Yang, Z. F.; Liu, C. L.

2014-04-01

In deregulated electricity markets, hydropower portfolio design has become an essential task for producers. The previous research on hydropower portfolio optimisation focused mainly on the maximisation of profits but did not take into account riverine ecosystem protection. Although profit maximisation is the major objective for producers in deregulated markets, protection of riverine ecosystems must be incorporated into the process of hydropower portfolio optimisation, especially against a background of increasing attention to environmental protection and stronger opposition to hydropower generation. This research seeks mainly to remind hydropower producers of the requirement of river protection when they design portfolios and help shift portfolio optimisation from economically oriented to ecologically friendly. We establish a framework to determine the optimal portfolio for a hydropower reservoir, accounting for both economic benefits and ecological needs. In this framework, the degree of natural flow regime alteration is adopted as a constraint on hydropower generation to protect riverine ecosystems, and the maximisation of mean annual revenue is set as the optimisation objective. The electricity volumes assigned in different electricity submarkets are optimised by the noisy genetic algorithm. The proposed framework is applied to China's Wangkuai Reservoir to test its effectiveness. The results show that the new framework could help to design eco-friendly portfolios that can ensure a planned profit and reduce alteration of the natural flow regime.

PRODUCT PORTFOLIO ANALYSIS - ARTHUR D. LITTLE MATRIX

Directory of Open Access Journals (Sweden)

Curmei Catalin Valeriu

2011-07-01

held by each product within a market, the performance potential of product portfolio and the financial aspects related to the resource allocation process for the products within the portfolio. It should also be noted that the tools and techniques specific to product portfolio analysis do not give accurate answers, despite the appearances created by the analysis stage, where the products are plotted rigorously. However, their main virtue is simplicity, as these highlight the managers’ need for further investigations.

Monitoring supports performance in a dual-task paradigm involving a risky decision-making task and a working memory task

Directory of Open Access Journals (Sweden)

Bettina eGathmann

2015-02-01

Full Text Available Performing two cognitively demanding tasks at the same time is known to decrease performance. The current study investigates the underlying executive functions of a dual-tasking situation involving the simultaneous performance of decision making under explicit risk and a working memory task. It is suggested that making a decision and performing a working memory task at the same time should particularly require monitoring - an executive control process supervising behavior and the state of processing on two tasks. To test the role of a supervisory/monitoring function in such a dual-tasking situation we investigated 122 participants with the Game of Dice Task plus 2-back task (GDT plus 2-back task. This dual task requires participants to make decisions under risk and to perform a 2-back working memory task at the same time. Furthermore, a task measuring a set of several executive functions gathered in the term concept formation (Modified Card Sorting Test, MCST and the newly developed Balanced Switching Task (BST, measuring monitoring in particular, were used. The results demonstrate that concept formation and monitoring are involved in the simultaneous performance of decision making under risk and a working memory task. In particular, the mediation analysis revealed that BST performance partially mediates the influence of MCST performance on the GDT plus 2-back task. These findings suggest that monitoring is one important subfunction for superior performance in a dual-tasking situation including decision making under risk and a working memory task.

Monitoring supports performance in a dual-task paradigm involving a risky decision-making task and a working memory task

Science.gov (United States)

Gathmann, Bettina; Schiebener, Johannes; Wolf, Oliver T.; Brand, Matthias

2015-01-01

Performing two cognitively demanding tasks at the same time is known to decrease performance. The current study investigates the underlying executive functions of a dual-tasking situation involving the simultaneous performance of decision making under explicit risk and a working memory task. It is suggested that making a decision and performing a working memory task at the same time should particularly require monitoring—an executive control process supervising behavior and the state of processing on two tasks. To test the role of a supervisory/monitoring function in such a dual-tasking situation we investigated 122 participants with the Game of Dice Task plus 2-back task (GDT plus 2-back task). This dual task requires participants to make decisions under risk and to perform a 2-back working memory task at the same time. Furthermore, a task measuring a set of several executive functions gathered in the term concept formation (Modified Card Sorting Test, MCST) and the newly developed Balanced Switching Task (BST), measuring monitoring in particular, were used. The results demonstrate that concept formation and monitoring are involved in the simultaneous performance of decision making under risk and a working memory task. In particular, the mediation analysis revealed that BST performance partially mediates the influence of MCST performance on the GDT plus 2-back task. These findings suggest that monitoring is one important subfunction for superior performance in a dual-tasking situation including decision making under risk and a working memory task. PMID:25741308

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…

The Task Is Not Enough: Processing Approaches to Task-Based Performance

Science.gov (United States)

Skehan, Peter; Xiaoyue, Bei; Qian, Li; Wang, Zhan

2012-01-01

This article reports on three research studies, all of which concern second language task performance. The first focuses on planning, and compares on-line and strategic planning as well as task repetition. The second study examines the role of familiarity on task performance, and compares this with conventional strategic planning. The third study…

Formation and bases of the analysis of the investment portfolio of the enterprise

Directory of Open Access Journals (Sweden)

I. I. Hasanshin

2018-01-01

Full Text Available This article discusses several methods for project design and analysis. After all, they are the key ones in creating a new IT portfolio of the enterprise, according to the standards for the formation and management of projects, which is especially important in investment analysis. Considering these stages, we touch topics from the beginning of an enterprise to its formation, as a working business. After all, every enterprise begins its life with a choice of methods, stopping at one, it chooses a plan and sets tasks. Attraction of investments will be one of the main points in this task. For today, investments are the cause for the consequences of economic processes and various phenomena in the economy. This view will be of interest to specialists in the field of information technology and economic sciences. The idea is substantiated that the analysis of such results gives a good assessment in order to further identify weaknesses, build business processes and solutions from the point of view of forming a new portfolio of the enterprise and tools that allow determining the profitability of the module or the project as a whole in terms of money and technical equivalents. The article helps to reveal the topic and the main problem that is interesting and relevant for today, what method of attracting investors and implementing / shaping the IT portfolio of the project, choose which innovative portfolio management systems should be used and how they differ from traditional ones and how to properly link them with architecture of the enterprise. The key stages of investment analysis will be: increase in profits, accumulation of resources, proper portfolio formation and diversification.

Predictive performance models and multiple task performance

Science.gov (United States)

Wickens, Christopher D.; Larish, Inge; Contorer, Aaron

1989-01-01

Five models that predict how performance of multiple tasks will interact in complex task scenarios are discussed. The models are shown in terms of the assumptions they make about human operator divided attention. The different assumptions about attention are then empirically validated in a multitask helicopter flight simulation. It is concluded from this simulation that the most important assumption relates to the coding of demand level of different component tasks.

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.

Optimal wind power deployment in Europe. A portfolio approach

International Nuclear Information System (INIS)

Roques, Fabien; Hiroux, Celine; Saguan, Marcelo

2010-01-01

Geographic diversification of wind farms can smooth out the fluctuations in wind power generation and reduce the associated system balancing and reliability costs. The paper uses historical wind production data from five European countries (Austria, Denmark, France, Germany, and Spain) and applies the Mean-Variance Portfolio theory to identify cross-country portfolios that minimise the total variance of wind production for a given level of production. Theoretical unconstrained portfolios show that countries (Spain and Denmark) with the best wind resource or whose size contributes to smoothing out the country output variability dominate optimal portfolios. The methodology is then elaborated to derive optimal constrained portfolios taking into account national wind resource potential and transmission constraints and compare them with the projected portfolios for 2020. Such constraints limit the theoretical potential efficiency gains from geographical diversification, but there is still considerable room to improve performance from actual or projected portfolios. These results highlight the need for more cross-border interconnection capacity, for greater coordination of European renewable support policies, and for renewable support mechanisms and electricity market designs providing locational incentives. Under these conditions, a mechanism for renewables credits trading could help aligning wind power portfolios with the theoretically efficient geographic dispersion. (author)

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…

Planning and task management in Parkinson's disease: differential emphasis in dual-task performance.

Science.gov (United States)

Bialystok, Ellen; Craik, Fergus I M; Stefurak, Taresa

2008-03-01

Seventeen patients diagnosed with Parkinson's disease completed a complex computer-based task that involved planning and management while also performing an attention-demanding secondary task. The tasks were performed concurrently, but it was necessary to switch from one to the other. Performance was compared to a group of healthy age-matched control participants and a group of young participants. Parkinson's patients performed better than the age-matched controls on almost all measures and as well as the young controls in many cases. However, the Parkinson's patients achieved this by paying relatively less attention to the secondary task and focusing attention more on the primary task. Thus, Parkinson's patients can apparently improve their performance on some aspects of a multidimensional task by simplifying task demands. This benefit may occur as a consequence of their inflexible exaggerated attention to some aspects of a complex task to the relative neglect of other aspects.

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.

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.

MODERN THEORETICAL APPROACHES CREDIT PORTFOLIO QUALITY MANAGEMENT OF COMMERCIAL BANK

Directory of Open Access Journals (Sweden)

Victoria Lisnic

2016-12-01

Full Text Available Credit portfolio management means the totality of financial and economic decisions realization aimed at achieving optimal ratio of performance indicators of loan portfolio. If low-quality loans increase, the reduction of productive assets volume and, respectively, profitability from banking lending. In extreme cases a such situation could lead to bank bankruptcy. At present bank loan portfolio quality assessment is an important component of bank management.

On long-only information-based portfolio diversification framework

Science.gov (United States)

Santos, Raphael A.; Takada, Hellinton H.

2014-12-01

Using the concepts from information theory, it is possible to improve the traditional frameworks for long-only asset allocation. In modern portfolio theory, the investor has two basic procedures: the choice of a portfolio that maximizes its risk-adjusted excess return or the mixed allocation between the maximum Sharpe portfolio and the risk-free asset. In the literature, the first procedure was already addressed using information theory. One contribution of this paper is the consideration of the second procedure in the information theory context. The performance of these approaches was compared with three traditional asset allocation methodologies: the Markowitz's mean-variance, the resampled mean-variance and the equally weighted portfolio. Using simulated and real data, the information theory-based methodologies were verified to be more robust when dealing with the estimation errors.

Task complexity, student perceptions of vocabulary learning in EFL, and task performance.

Science.gov (United States)

Wu, Xiaoli; Lowyck, Joost; Sercu, Lies; Elen, Jan

2013-03-01

The study deepened our understanding of how students' self-efficacy beliefs contribute to the context of teaching English as a foreign language in the framework of cognitive mediational paradigm at a fine-tuned task-specific level. The aim was to examine the relationship among task complexity, self-efficacy beliefs, domain-related prior knowledge, learning strategy use, and task performance as they were applied to English vocabulary learning from reading tasks. Participants were 120 second-year university students (mean age 21) from a Chinese university. This experiment had two conditions (simple/complex). A vocabulary level test was first conducted to measure participants' prior knowledge of English vocabulary. Participants were then randomly assigned to one of the learning tasks. Participants were administered task booklets together with the self-efficacy scales, measures of learning strategy use, and post-tests. Data obtained were submitted to multivariate analysis of variance (MANOVA) and path analysis. Results from the MANOVA model showed a significant effect of vocabulary level on self-efficacy beliefs, learning strategy use, and task performance. Task complexity showed no significant effect; however, an interaction effect between vocabulary level and task complexity emerged. Results from the path analysis showed self-efficacy beliefs had an indirect effect on performance. Our results highlighted the mediating role of self-efficacy beliefs and learning strategy use. Our findings indicate that students' prior knowledge plays a crucial role on both self-efficacy beliefs and task performance, and the predictive power of self-efficacy on task performance may lie in its association with learning strategy use. © 2011 The British Psychological Society.

Quantifying the role of personal management style in the success of investment portfolios

Directory of Open Access Journals (Sweden)

E.A. Wagenaar

2014-01-01

Full Text Available It is extremely difficult to quantify the effect of different management styles of portfolio managers upon the success of their portfolios. Various mathematical models in the literature attempt to predict the risk and returns of portfolios according to changes in the economic arena, but these models usually do not take into account the personal styles of portfolio managers. The aim of this paper is a modest attempt at quantifying the effect of different managerial styles upon decisions regarding portfolios. This is accomplished by the formulation of a mathematical performance index that portrays the influence of a portfolio manager's personal and managerial characteristics on the success of his portfolio.

Portfolio Risk of International Diversification of Kosovo Pension Fund: A Historical Perspective

Directory of Open Access Journals (Sweden)

Florin Aliu

2017-01-01

Full Text Available Finance do not stand on static variables like exact sciences, they are changeable and influenced from human actions. The question where to invest funds, is a crucial task for financial managers. The study aimed at assessing the portfolio risk of different asset managers of the Kosovo Pension and Saving Trust. In general, the assessment has been categorized in two historical perspectives. The first phase is an assessment of the portfolio risk of the fund from 2003 to 2009 and the second phase is from 2003 to 2013. In general, portfolio risk in the second stage has shown a reduction as compared to the first stage. However, the return side shows also a reduction in the second phase than the first one. The overall risk of Kosovo Pension and Saving Trust has been in accepted range. Majority of money have been invested in stocks which automatically exposes huge risk on KPST portfolio, since it is proven that financial markets are not stable and they are prone to asset bubbles.

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.

Analysis of the rebalancing frequency in log-optimal portfolio selection

OpenAIRE

Kuhn, Daniel; Luenberger, David G.

2010-01-01

In a dynamic investment situation, the right timing of portfolio revisions and adjustments is essential to sustain long-term growth. A high rebalancing frequency reduces the portfolio performance in the presence of transaction costs, whereas a low rebalancing frequency entails a static investment strategy that hardly reacts to changing market conditions. This article studies a family of portfolio problems in a Black-Scholes type economy which depend parametrically on the rebalancing frequency...

Short-term memory and dual task performance

Science.gov (United States)

Regan, J. E.

1982-01-01

Two hypotheses concerning the way in which short-term memory interacts with another task in a dual task situation are considered. It is noted that when two tasks are combined, the activity of controlling and organizing performance on both tasks simultaneously may compete with either task for a resource; this resource may be space in a central mechanism or general processing capacity or it may be some task-specific resource. If a special relationship exists between short-term memory and control, especially if there is an identity relationship between short-term and a central controlling mechanism, then short-term memory performance should show a decrement in a dual task situation. Even if short-term memory does not have any particular identity with a controlling mechanism, but both tasks draw on some common resource or resources, then a tradeoff between the two tasks in allocating resources is possible and could be reflected in performance. The persistent concurrence cost in memory performance in these experiments suggests that short-term memory may have a unique status in the information processing system.

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...

Performance of Socially Responsible Stocks Portfolios – The Impact of Global Financial Crisis

Directory of Open Access Journals (Sweden)

Vanita Tripathi

2016-01-01

Full Text Available For the effective and better implementation of CSR law, development of SRI market in the investment world is essential. Unless the investors turn socially responsible, CSR principles cannot be enforced in practice. This paper examines whether the companies that are socially responsible are performing better than general companies in terms of risk, return and various risk-adjusted measures during pre-crisis, crisis and post-crisis periods. We find that despite having higher risk, socially responsible stocks portfolios generated significantly higher returns and hence outperformed other portfolios on the basis of all risk-adjusted measures, as well as net selectivity returns during crisis period. The results uphold even with the use of Fama-French three factor model for estimating excess returns. Besides augmenting existing literature, our results clearly corroborate the fact that investors can derive benefits by investing in socially responsible companies (especially in crisis period. The study supports the view that socially responsible products can be used as a safe investment vehicle by investors during adversity. Therefore, regulators, policy makers and mutual funds should construct and make available various socially responsible investment products to initiate the movement of socially responsible investing in India.

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.

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.

Portfolio of automated trading systems: complexity and learning set size issues.

Science.gov (United States)

Raudys, Sarunas

2013-03-01

In this paper, we consider using profit/loss histories of multiple automated trading systems (ATSs) as N input variables in portfolio management. By means of multivariate statistical analysis and simulation studies, we analyze the influences of sample size (L) and input dimensionality on the accuracy of determining the portfolio weights. We find that degradation in portfolio performance due to inexact estimation of N means and N(N - 1)/2 correlations is proportional to N/L; however, estimation of N variances does not worsen the result. To reduce unhelpful sample size/dimensionality effects, we perform a clustering of N time series and split them into a small number of blocks. Each block is composed of mutually correlated ATSs. It generates an expert trading agent based on a nontrainable 1/N portfolio rule. To increase the diversity of the expert agents, we use training sets of different lengths for clustering. In the output of the portfolio management system, the regularized mean-variance framework-based fusion agent is developed in each walk-forward step of an out-of-sample portfolio validation experiment. Experiments with the real financial data (2003-2012) confirm the effectiveness of the suggested approach.

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.

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.

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

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.

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

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.

The predictive value of general movement tasks in assessing occupational task performance.

Science.gov (United States)

Frost, David M; Beach, Tyson A C; McGill, Stuart M; Callaghan, Jack P

2015-01-01

Within the context of evaluating individuals' movement behavior it is generally assumed that the tasks chosen will predict their competency to perform activities relevant to their occupation. This study sought to examine whether a battery of general tasks could be used to predict the movement patterns employed by firefighters to perform select job-specific skills. Fifty-two firefighters performed a battery of general and occupation-specific tasks that simulated the demands of firefighting. Participants' peak lumbar spine and frontal plane knee motion were compared across tasks. During 85% of all comparisons, the magnitude of spine and knee motion was greater during the general movement tasks than observed during the firefighting skills. Certain features of a worker's movement behavior may be exhibited across a range of tasks. Therefore, provided that a movement screen's tasks expose the motions of relevance for the population being tested, general evaluations could offer valuable insight into workers' movement competency or facilitate an opportunity to establish an evidence-informed intervention.

Statistically Efficient Construction of α-Risk-Minimizing Portfolio

Directory of Open Access Journals (Sweden)

Hiroyuki Taniai

2012-01-01

Full Text Available We propose a semiparametrically efficient estimator for α-risk-minimizing portfolio weights. Based on the work of Bassett et al. (2004, an α-risk-minimizing portfolio optimization is formulated as a linear quantile regression problem. The quantile regression method uses a pseudolikelihood based on an asymmetric Laplace reference density, and asymptotic properties such as consistency and asymptotic normality are obtained. We apply the results of Hallin et al. (2008 to the problem of constructing α-risk-minimizing portfolios using residual signs and ranks and a general reference density. Monte Carlo simulations assess the performance of the proposed method. Empirical applications are also investigated.

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)

A Dynamic Spreadsheet Model for Determining the Portfolio Frontier for BSE30 Stocks

Directory of Open Access Journals (Sweden)

Dr. Anupam Mitra

2014-01-01

Full Text Available Introductory investments courses revolve around Harry Markowitz’s modern portfolio theory and William Sharpe’s Index for the performance measurement of those portfolios. This paper presents a simplified perspective of Markowitz’s contributions to Modern Portfolio Theory. It is to see the effect of duration of historical data on the risk and return of the portfolio and to see the applicability of risk-reward logic. The empirical results also show that short selling may increase the risk of the portfolio when the investor is instability preferred.

From the microscope to the macroscopic: changing from the bench to portfolio management.

Science.gov (United States)

Sachs, Michael

2017-11-01

A role in portfolio management is ideal for individuals who enjoy tackling challenges that have both technical and business components. Portfolio management provides objective insights and analytics to support research and development decision making and planning. Successful practitioners usually have strong analytical abilities developed from a background in either science or business. Portfolio managers often advise key decision makers at both the team and senior management level and thus require robust oral, written, and interpersonal communication skills. Day-to-day tasks are rarely the same, and comfort with change and the unknown is essential. Here I will discuss my experience as a portfolio manager in a larger biopharmaceutical company and the skills from academic research I leveraged to make the transition. © 2017 Sachs. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

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....

Stock portfolio selection using Dempster–Shafer evidence theory

Directory of Open Access Journals (Sweden)

Gour Sundar Mitra Thakur

2018-04-01

Full Text Available Markowitz’s return–risk model for stock portfolio selection is based on the historical return data of assets. In addition to the effect of historical return, there are many other critical factors which directly or indirectly influence the stock market. We use the fuzzy Delphi method to identify the critical factors initially. Factors having lower correlation coefficients are finally considered for further consideration. The critical factors and historical data are used to apply Dempster–Shafer evidence theory to rank the stocks. Then, a portfolio selection model that prefers stocks with higher rank is proposed. Illustration is done using stocks under Bombay Stock Exchange (BSE. Simulation is done by Ant Colony Optimization. The performance of the outcome is found satisfactory when compared with recent performance of the assets. Keywords: Stock portfolio selection, Ranking, Dempster–Shafer evidence theory, Ant Colony Optimization, Fuzzy Delphi method

Classification of non-performing loans portfolio using Multilayer Perceptron artificial neural networks

Directory of Open Access Journals (Sweden)

Flávio Clésio Silva de Souza

2014-06-01

Full Text Available The purpose of the present research is to apply a Multilayer Perceptron (MLP neural network technique to create classification models from a portfolio of Non-Performing Loans (NPLs to classify this type of credit derivative. These credit derivatives are characterized as the amount of loans that were not paid and are already overdue more than 90 days. Since these titles are, because of legislative motives, moved by losses, Credit Rights Investment Funds (FDIC performs the purchase of these debts and the recovery of the credits. Using the Multilayer Perceptron (MLP architecture of Artificial Neural Network (ANN, classification models regarding the posterior recovery of these debts were created. To evaluate the performance of the models, evaluation metrics of classification relating to the neural networks with different architectures were presented. The results of the classifications were satisfactory, given the classification models were successful in the presented economics costs structure.

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.

Single-task and dual-task tandem gait test performance after concussion.

Science.gov (United States)

Howell, David R; Osternig, Louis R; Chou, Li-Shan

2017-07-01

To compare single-task and dual-task tandem gait test performance between athletes after concussion with controls on observer-timed, spatio-temporal, and center-of-mass (COM) balance control measurements. Ten participants (19.0±5.5years) were prospectively identified and completed a tandem gait test protocol within 72h of concussion and again 1 week, 2 weeks, 1 month, and 2 months post-injury. Seven uninjured controls (20.0±4.5years) completed the same protocol in similar time increments. Tandem gait test trials were performed with (dual-task) and without (single-task) concurrently performing a cognitive test as whole-body motion analysis was performed. Outcome variables included test completion time, average tandem gait velocity, cadence, and whole-body COM frontal plane displacement. Concussion participants took significantly longer to complete the dual-task tandem gait test than controls throughout the first 2 weeks post-injury (mean time=16.4 [95% CI: 13.4-19.4] vs. 10.1 [95% CI: 6.4-13.7] seconds; p=0.03). Single-task tandem gait times were significantly lower 72h post-injury (p=0.04). Dual-task cadence was significantly lower for concussion participants than controls (89.5 [95% CI: 68.6-110.4] vs. 127.0 [95% CI: 97.4-156.6] steps/minute; p=0.04). Moderately-high to high correlations between tandem gait test time and whole-body COM medial-lateral displacement were detected at each time point during dual-task gait (r s =0.70-0.93; p=0.03-0.001). Adding a cognitive task during the tandem gait test resulted in longer detectable deficits post-concussion compared to the traditional single-task tandem gait test. As a clinical tool to assess dynamic motor function, tandem gait may assist with return to sport decisions after concussion. Copyright © 2017 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

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

Evaluating dynamic covariance matrix forecasting and portfolio optimization

OpenAIRE

Sendstad, Lars Hegnes; Holten, Dag Martin

2012-01-01

In this thesis we have evaluated the covariance forecasting ability of the simple moving average, the exponential moving average and the dynamic conditional correlation models. Overall we found that a dynamic portfolio can gain significant improvements by implementing a multivariate GARCH forecast. We further divided the global investment universe into sectors and regions in order to investigate the relative portfolio performance of several asset allocation strategies with both variance and c...

Research on regularized mean-variance portfolio selection strategy with modified Roy safety-first principle.

Science.gov (United States)

Atta Mills, Ebenezer Fiifi Emire; Yan, Dawen; Yu, Bo; Wei, Xinyuan

2016-01-01

We propose a consolidated risk measure based on variance and the safety-first principle in a mean-risk portfolio optimization framework. The safety-first principle to financial portfolio selection strategy is modified and improved. Our proposed models are subjected to norm regularization to seek near-optimal stable and sparse portfolios. We compare the cumulative wealth of our preferred proposed model to a benchmark, S&P 500 index for the same period. Our proposed portfolio strategies have better out-of-sample performance than the selected alternative portfolio rules in literature and control the downside risk of the portfolio returns.

Performance samples on academic tasks : improving prediction of academic performance

NARCIS (Netherlands)

Tanilon, Jenny

2011-01-01

This thesis is about the development and validation of a performance-based test, labeled as Performance Samples on academic tasks in Education and Child Studies (PSEd). PSEd is designed to identify students who are most able to perform the academic tasks involved in an Education and Child Studies

A MODEL OF HETEROGENEOUS DISTRIBUTED SYSTEM FOR FOREIGN EXCHANGE PORTFOLIO ANALYSIS

Directory of Open Access Journals (Sweden)

Dragutin Kermek

2006-06-01

Full Text Available The paper investigates the design of heterogeneous distributed system for foreign exchange portfolio analysis. The proposed model includes few separated and dislocated but connected parts through distributed mechanisms. Making system distributed brings new perspectives to performance busting where software based load balancer gets very important role. Desired system should spread over multiple, heterogeneous platforms in order to fulfil open platform goal. Building such a model incorporates different patterns from GOF design patterns, business patterns, J2EE patterns, integration patterns, enterprise patterns, distributed design patterns to Web services patterns. The authors try to find as much as possible appropriate patterns for planned tasks in order to capture best modelling and programming practices.

INFLUENCE OF REGIME SWITCHING TO RISK IN PORT-MODERN PORTFOLIO MANAGEMENT

OpenAIRE

Cristina Geambaşu; Liviu Geambaşu; Iulia Jianu

2013-01-01

The present financial crises determines an increase in analysing the application of regime switching over portfolio investments. We applied the switching regimes to measurement of risk as presented in post-modern portfolio management theory. Post-modern portfolio theory include investor’s tendency to measure risk as the chance to obtain from the investment performed a return lower than the minimum expected by him. The investor, as presented by behavioural finance, is more concerned about his ...

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.

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

Musical expertise has minimal impact on dual task performance.

Science.gov (United States)

Cocchini, Gianna; Filardi, Maria Serena; Crhonkova, Marcela; Halpern, Andrea R

2017-05-01

Studies investigating effect of practice on dual task performance have yielded conflicting findings, thus supporting different theoretical accounts about the organisation of attentional resources when tasks are performed simultaneously. Because practice has been proven to reduce the demand of attention for the trained task, the impact of long-lasting training on one task is an ideal way to better understand the mechanisms underlying dual task decline in performance. Our study compared performance during dual task execution in expert musicians compared to controls with little if any musical experience. Participants performed a music recognition task and a visuo-spatial task separately (single task) or simultaneously (dual task). Both groups showed a significant but similar performance decline during dual tasks. In addition, the two groups showed a similar decline of dual task performance during encoding and retrieval of the musical information, mainly attributed to a decline in sensitivity. Our results suggest that attention during dual tasks is similarly distributed by expert and non-experts. These findings are in line with previous studies showing a lack of sensitivity to difficulty and lack of practice effect during dual tasks, supporting the idea that different tasks may rely on different and not-sharable attentional resources.

Mood states determine the degree of task shielding in dual-task performance.

Science.gov (United States)

Zwosta, Katharina; Hommel, Bernhard; Goschke, Thomas; Fischer, Rico

2013-01-01

Current models of multitasking assume that dual-task performance and the degree of multitasking are affected by cognitive control strategies. In particular, cognitive control is assumed to regulate the amount of shielding of the prioritised task from crosstalk from the secondary task. We investigated whether and how task shielding is influenced by mood states. Participants were exposed to two short film clips, one inducing high and one inducing low arousal, of either negative or positive content. Negative mood led to stronger shielding of the prioritised task (i.e., less crosstalk) than positive mood, irrespective of arousal. These findings support the assumption that emotional states determine the parameters of cognitive control and play an important role in regulating dual-task performance.

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…

Dividing attention between tasks : Testing whether explicit payoff functions elicit optimal dual-task performance

NARCIS (Netherlands)

Farmer, George D.; Janssen, C.P.|info:eu-repo/dai/nl/412781654; Nguyen, Anh T; Brumby, Duncan P.

2018-01-01

We test people's ability to optimize performance across two concurrent tasks. Participants performed a number entry task while controlling a randomly moving cursor with a joystick. Participants received explicit feedback on their performance on these tasks in the form of a single combined score.

Portfolio selection problem: a comparison of fuzzy goal programming and linear physical programming

Directory of Open Access Journals (Sweden)

Fusun Kucukbay

2016-04-01

Full Text Available Investors have limited budget and they try to maximize their return with minimum risk. Therefore this study aims to deal with the portfolio selection problem. In the study two criteria are considered which are expected return, and risk. In this respect, linear physical programming (LPP technique is applied on Bist 100 stocks to be able to find out the optimum portfolio. The analysis covers the period April 2009- March 2015. This period is divided into two; April 2009-March 2014 and April 2014 – March 2015. April 2009-March 2014 period is used as data to find an optimal solution. April 2014-March 2015 period is used to test the real performance of portfolios. The performance of the obtained portfolio is compared with that obtained from fuzzy goal programming (FGP. Then the performances of both method, LPP and FGP are compared with BIST 100 in terms of their Sharpe Indexes. The findings reveal that LPP for portfolio selection problem is a good alternative to FGP.

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...

Linear versus quadratic portfolio optimization model with transaction cost

Science.gov (United States)

Razak, Norhidayah Bt Ab; Kamil, Karmila Hanim; Elias, Siti Masitah

2014-06-01

Optimization model is introduced to become one of the decision making tools in investment. Hence, it is always a big challenge for investors to select the best model that could fulfill their goal in investment with respect to risk and return. In this paper we aims to discuss and compare the portfolio allocation and performance generated by quadratic and linear portfolio optimization models namely of Markowitz and Maximin model respectively. The application of these models has been proven to be significant and popular among others. However transaction cost has been debated as one of the important aspects that should be considered for portfolio reallocation as portfolio return could be significantly reduced when transaction cost is taken into consideration. Therefore, recognizing the importance to consider transaction cost value when calculating portfolio' return, we formulate this paper by using data from Shariah compliant securities listed in Bursa Malaysia. It is expected that, results from this paper will effectively justify the advantage of one model to another and shed some lights in quest to find the best decision making tools in investment for individual investors.

MANAGING THE USE OF DERIVATIVE INSTRUMENTS FOR PORTFOLIO RISK PURPOSES

Directory of Open Access Journals (Sweden)

Mădălina Antoaneta RĂDOI

2017-05-01

Full Text Available The priority in portfolio management is a good risk assessment and management. Of great importance is the margin that an asset portfolio guarantor must use with specific expertise in certain areas of market temporal inefficiency in order to improve its management performance. The relevant validity of the financial market and the emphasis laid on risk management carried along the development of financial instruments tailored to risk management. New derivative financial instruments have revolutionized the methods of portfolio management, of corporate treasury management, of banking management and, more generally, all financial strategies.

Long term contracts in portfolios of core LDC gas supply

International Nuclear Information System (INIS)

John, F.E.

1992-01-01

This paper recommends that local distribution companies (LDCs) should use a portfolio approach for their gas supply strategy. The author recommends that LDCs not rely on spot supplies to meet the peak needs of the core residential and commercial markets. He recommends that a secure supply through long-term contracts are better sources than spot or even intermediate term suppliers. The paper provides a brief outline format of the advantages to the use of a portfolio approach which include the rapid restructuring of the market, general changes in the market, and general market performance. By maintaining a portfolio, a list of available natural gas suppliers is always available. This portfolio also acts to compare pricing between short, medium, and long-term pricing for the LDCs

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...

Portfolio Optimization of Nanomaterial Use in Clean Energy Technologies.

Science.gov (United States)

Moore, Elizabeth A; Babbitt, Callie W; Gaustad, Gabrielle; Moore, Sean T

2018-04-03

While engineered nanomaterials (ENMs) are increasingly incorporated in diverse applications, risks of ENM adoption remain difficult to predict and mitigate proactively. Current decision-making tools do not adequately account for ENM uncertainties including varying functional forms, unique environmental behavior, economic costs, unknown supply and demand, and upstream emissions. The complexity of the ENM system necessitates a novel approach: in this study, the adaptation of an investment portfolio optimization model is demonstrated for optimization of ENM use in renewable energy technologies. Where a traditional investment portfolio optimization model maximizes return on investment through optimal selection of stock, ENM portfolio optimization maximizes the performance of energy technology systems by optimizing selective use of ENMs. Cumulative impacts of multiple ENM material portfolios are evaluated in two case studies: organic photovoltaic cells (OPVs) for renewable energy and lithium-ion batteries (LIBs) for electric vehicles. Results indicate ENM adoption is dependent on overall performance and variance of the material, resource use, environmental impact, and economic trade-offs. From a sustainability perspective, improved clean energy applications can help extend product lifespans, reduce fossil energy consumption, and substitute ENMs for scarce incumbent materials.

Optimization of revenues from a distributed generation portfolio: a case study

NARCIS (Netherlands)

Geysen, D.; Kessels, K.; Hommelberg, M.; Ghijsen, M.; Tielemans, Y.; Vinck, K.

2011-01-01

Many companies are investing in energy production from renewable energy sources and are looking at ways to optimize their portfolio performance. The case study under consideration aims at maximizing the revenues from such a distributed energy generation portfolio, consisting of gas engines and a PV

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…

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

Task performance in astronomical adaptive optics

Science.gov (United States)

Barrett, Harrison H.; Myers, Kyle J.; Devaney, Nicholas; Dainty, J. C.; Caucci, Luca

2006-06-01

In objective or task-based assessment of image quality, figures of merit are defined by the performance of some specific observer on some task of scientific interest. This methodology is well established in medical imaging but is just beginning to be applied in astronomy. In this paper we survey the theory needed to understand the performance of ideal or ideal-linear (Hotelling) observers on detection tasks with adaptive-optical data. The theory is illustrated by discussing its application to detection of exoplanets from a sequence of short-exposure images.

The effects of stimulus modality and task integrality: Predicting dual-task performance and workload from single-task levels

Science.gov (United States)

Hart, S. G.; Shively, R. J.; Vidulich, M. A.; Miller, R. C.

1986-01-01

The influence of stimulus modality and task difficulty on workload and performance was investigated. The goal was to quantify the cost (in terms of response time and experienced workload) incurred when essentially serial task components shared common elements (e.g., the response to one initiated the other) which could be accomplished in parallel. The experimental tasks were based on the Fittsberg paradigm; the solution to a SternBERG-type memory task determines which of two identical FITTS targets are acquired. Previous research suggested that such functionally integrated dual tasks are performed with substantially less workload and faster response times than would be predicted by suming single-task components when both are presented in the same stimulus modality (visual). The physical integration of task elements was varied (although their functional relationship remained the same) to determine whether dual-task facilitation would persist if task components were presented in different sensory modalities. Again, it was found that the cost of performing the two-stage task was considerably less than the sum of component single-task levels when both were presented visually. Less facilitation was found when task elements were presented in different sensory modalities. These results suggest the importance of distinguishing between concurrent tasks that complete for limited resources from those that beneficially share common resources when selecting the stimulus modalities for information displays.

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…

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.

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.

Event-related potentials and secondary task performance during simulated driving.

Science.gov (United States)

Wester, A E; Böcker, K B E; Volkerts, E R; Verster, J C; Kenemans, J L

2008-01-01

Inattention and distraction account for a substantial number of traffic accidents. Therefore, we examined the impact of secondary task performance (an auditory oddball task) on a primary driving task (lane keeping). Twenty healthy participants performed two 20-min tests in the Divided Attention Steering Simulator (DASS). The visual secondary task of the DASS was replaced by an auditory oddball task to allow recording of brain activity. The driving task and the secondary (distracting) oddball task were presented in isolation and simultaneously, to assess their mutual interference. In addition to performance measures (lane keeping in the primary driving task and reaction speed in the secondary oddball task), brain activity, i.e. event-related potentials (ERPs), was recorded. Performance parameters on the driving test and the secondary oddball task did not differ between performance in isolation and simultaneous performance. However, when both tasks were performed simultaneously, reaction time variability increased in the secondary oddball task. Analysis of brain activity indicated that ERP amplitude (P3a amplitude) related to the secondary task, was significantly reduced when the task was performed simultaneously with the driving test. This study shows that when performing a simple secondary task during driving, performance of the driving task and this secondary task are both unaffected. However, analysis of brain activity shows reduced cortical processing of irrelevant, potentially distracting stimuli from the secondary task during driving.

Paw Preference Correlates to Task Performance in Dogs

NARCIS (Netherlands)

Alphen, A. van; Bosse, T.; Frank, I.; Jonker, C.M.; Koeman, F.; Bara, B.G.; Barsalou, L.; Bucciarelli, M.

2005-01-01

A study involving 36 domestic dogs (Canis familiaris) in a simple search task provides evidence of a correlation between paw use and performance. The study was carried out to determine whether or not paw use is related to task performance. Different aspects of task performance were taken into

Annual Report: EPAct Complementary Program's Ultra-Deepwater R&D Portfolio and Unconventional Resources R&D Portfolio (30 September 2012)

Energy Technology Data Exchange (ETDEWEB)

none,; Rose, Kelly [NETL; Hakala, Alexandra [NETL; Guthrie, George [NETL

2012-09-30

This report summarizes FY13 research activities performed by the National Energy Technology Laboratory (NETL), Office of Research and Development (ORD), along with its partners in the Regional University Alliance (RUA) to fulfill research needs under the Energy Policy Act of 2005 (EPAct) Section 999's Complementary Program. Title IX, Subtitle J, Section 999A(d) of EPAct 2005 authorizes $50 million per year of federal oil and gas royalties, rents and bonus payments for an oil and natural gas research and development effort, the Ultra-Deepwater and Unconventional Natural Gas and Other Petroleum Resources Research Program. Section 999 further prescribes four program elements for the effort, one of which is the Complementary Research Program that is to be performed by NETL. This document lays out the plan for the research portfolio for the Complementary Research Program, with an emphasis on the 2013 funding. The Complementary Program consists of two research portfolios focused on domestic resources: (1) the Deepwater and Ultra-Deepwater Portfolio (UDW) (focused on hydrocarbons in reservoirs in extreme environments) and (2) the Unconventional Resources Portfolio (UCR) (focused on hydrocarbons in shale reservoirs). These two portfolios address the science base that enables these domestic resources to be produced responsibly, informing both regulators and operators. NETL is relying on a core Department of Energy-National Energy Technology Laboratory (DOE-NETL) competency in engineered-natural systems to develop this science base, allowing leveraging of decades of investment. NETL's Complementary Research Program research portfolios support the development of unbiased research and information for policymakers and the public, performing rapid predictions of possible outcomes associated with unexpected events, and carrying out quantitative assessments for energy policy stakeholders that accurately integrate the risks of safety and environmental impacts. The

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...

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...

Preferential processing of task-irrelevant beloved-related information and task performance: Two event-related potential studies.

Science.gov (United States)

Langeslag, Sandra J E; van Strien, Jan W

2017-09-18

People who are in love have better attention for beloved-related information, but report having trouble focusing on other tasks, such as (home)work. So, romantic love can both improve and hurt cognition. Emotional information is preferentially processed, which improves task performance when the information is task-relevant, but hurts task performance when it is task-irrelevant. Because beloved-related information is highly emotional, the effects of romantic love on cognition may resemble these effects of emotion on cognition. We examined whether beloved-related information is preferentially processed even when it is task-irrelevant and whether this hurts task performance. In two event-related potential studies, participants who had recently fallen in love performed a visuospatial short-term memory task. Task-irrelevant beloved, friend, and stranger faces were presented during maintenance (Study 1), or encoding (Study 2). The Early Posterior Negativity (EPN) reflecting early automatic attentional capturing and the Late Positive Potential (LPP) reflecting sustained motivated attention were largest for beloved pictures. Thus, beloved pictures are preferentially processed even when they are task-irrelevant. Task performance and reaction times did not differ between beloved, friend, and stranger conditions. Nevertheless, self-reported obsessive thinking about the beloved tended to correlate negatively with task performance, and positively with reaction times, across conditions. So, although task-irrelevant beloved-related information does not impact task performance, more obsessive thinking about the beloved might relate to poorer and slower overall task performance. More research is needed to clarify why people experience trouble focusing on beloved-unrelated tasks and how this negative effect of love on cognition could be reduced. Copyright © 2017 Elsevier Ltd. All rights reserved.

Selecting Large Portfolios of Social Projects in Public Organizations

Directory of Open Access Journals (Sweden)

Igor Litvinchev

2014-01-01

Full Text Available We address the portfolio selection of social projects in public organizations considering interdependencies (synergies affecting project funds requirements and tasks. A mixed integer linear programming model is proposed incorporating the most relevant aspects of the problem found in the literature. The model supports both complete (all or nothing and partial (a certain amount from a given interval of funding resource allocation policies. Numerical results for large-scale problem instances are presented.

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...

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

Heuristic Portfolio Trading Rules with Capital Gain Taxes

DEFF Research Database (Denmark)

Fischer, Marcel; Gallmeyer, Michael

2016-01-01

We study the out-of-sample performance of portfolio trading strategies used when an investor faces capital gain taxation and proportional transaction costs. Overlaying simple tax trading heuristics on trading strategies improves out-of-sample performance. For medium to large transaction costs......, no trading strategy can outperform a 1/N trading strategy augmented with a tax heuristic, not even the most tax and transaction cost-efficient buy-and-hold strategy. Overall, the best strategy is 1/N augmented with a heuristic that allows for a fixed deviation in absolute portfolio weights. Our results thus...... show that the best trading strategies balance diversification considerations and tax considerations....

Investigating Perfect Timesharing: The Relationship between IM-Compatible Tasks and Dual-Task Performance

Science.gov (United States)

Halvorson, Kimberly M.; Ebner, Herschel; Hazeltine, Eliot

2013-01-01

Why are dual-task costs reduced with ideomotor (IM) compatible tasks (Greenwald & Shulman, 1973; Lien, Proctor & Allen, 2002)? In the present experiments, we first examine three different measures of single-task performance (pure single-task blocks, mixed blocks, and long stimulus onset asynchrony [SOA] trials in dual-task blocks) and two…

On Partial Defaults in Portfolio Credit Risk : A Poisson Mixture Model Approach

OpenAIRE

Weißbach, Rafael; von Lieres und Wilkau, Carsten

2005-01-01

Most credit portfolio models exclusively calculate the loss distribution for a portfolio of performing counterparts. Conservative default definitions cause considerable insecurity about the loss for a long time after the default. We present three approaches to account for defaulted counterparts in the calculation of the economic capital. Two of the approaches are based on the Poisson mixture model CreditRisk+ and derive a loss distribution for an integrated portfolio. The third method treats ...

Task-relevant cognitive and motor functions are prioritized during prolonged speed-accuracy motor task performance.

Science.gov (United States)

Solianik, Rima; Satas, Andrius; Mickeviciene, Dalia; Cekanauskaite, Agne; Valanciene, Dovile; Majauskiene, Daiva; Skurvydas, Albertas

2018-06-01

This study aimed to explore the effect of prolonged speed-accuracy motor task on the indicators of psychological, cognitive, psychomotor and motor function. Ten young men aged 21.1 ± 1.0 years performed a fast- and accurate-reaching movement task and a control task. Both tasks were performed for 2 h. Despite decreased motivation, and increased perception of effort as well as subjective feeling of fatigue, speed-accuracy motor task performance improved during the whole period of task execution. After the motor task, the increased working memory function and prefrontal cortex oxygenation at rest and during conflict detection, and the decreased efficiency of incorrect response inhibition and visuomotor tracking were observed. The speed-accuracy motor task increased the amplitude of motor-evoked potentials, while grip strength was not affected. These findings demonstrate that to sustain the performance of 2-h speed-accuracy task under conditions of self-reported fatigue, task-relevant functions are maintained or even improved, whereas less critical functions are impaired.

Portfolio optimization for heavy-tailed assets: Extreme Risk Index vs. Markowitz

OpenAIRE

Mainik, Georg; Mitov, Georgi; Rüschendorf, Ludger

2015-01-01

Using daily returns of the S&P 500 stocks from 2001 to 2011, we perform a backtesting study of the portfolio optimization strategy based on the extreme risk index (ERI). This method uses multivariate extreme value theory to minimize the probability of large portfolio losses. With more than 400 stocks to choose from, our study seems to be the first application of extreme value techniques in portfolio management on a large scale. The primary aim of our investigation is the potential of ERI in p...

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.

Portfolio Implementation Risk Management Using Evolutionary Multiobjective Optimization

Directory of Open Access Journals (Sweden)

David Quintana

2017-10-01

Full Text Available Portfolio management based on mean-variance portfolio optimization is subject to different sources of uncertainty. In addition to those related to the quality of parameter estimates used in the optimization process, investors face a portfolio implementation risk. The potential temporary discrepancy between target and present portfolios, caused by trading strategies, may expose investors to undesired risks. This study proposes an evolutionary multiobjective optimization algorithm aiming at regions with solutions more tolerant to these deviations and, therefore, more reliable. The proposed approach incorporates a user’s preference and seeks a fine-grained approximation of the most relevant efficient region. The computational experiments performed in this study are based on a cardinality-constrained problem with investment limits for eight broad-category indexes and 15 years of data. The obtained results show the ability of the proposed approach to address the robustness issue and to support decision making by providing a preferred part of the efficient set. The results reveal that the obtained solutions also exhibit a higher tolerance to prediction errors in asset returns and variance–covariance matrix.

Trait Mindfulness and Cognitive Task Performance

Directory of Open Access Journals (Sweden)

Emalee J. W. Quickel

2014-11-01

Full Text Available Mindfulness meditation (MM training has been shown to have positive effects on working memory and focused attention tasks. Clarifying the construct of mindfulness is important so that mindfulness can be studied effectively in individual differences and cognition research. The current study tested whether trait mindfulness alone explains any of the variability on task performance. Five commonly used mindfulness scales, as well as six standardized and experimental attention and working memory tasks were administered to 164 participants with no meditation experience. Confirmatory factor analysis found that the common variance denoted by measures of trait mindfulness is unrelated to the common variance among tasks requiring focused attention. These results indicate that mindfulness scales may not be capturing the attentional aspects of mindfulness. Individuals who score high on mindfulness scales do not perform better on focused attention tasks than those who score lower on mindfulness scales. These results have implications for defining and operationalizing mindfulness.

Multi-objective mean-variance-skewness model for generation portfolio allocation in electricity markets

Energy Technology Data Exchange (ETDEWEB)

Pindoriya, N.M.; Singh, S.N. [Department of Electrical Engineering, Indian Institute of Technology Kanpur, Kanpur 208016 (India); Singh, S.K. [Indian Institute of Management Lucknow, Lucknow 226013 (India)

2010-10-15

This paper proposes an approach for generation portfolio allocation based on mean-variance-skewness (MVS) model which is an extension of the classical mean-variance (MV) portfolio theory, to deal with assets whose return distribution is non-normal. The MVS model allocates portfolios optimally by considering the maximization of both the expected return and skewness of portfolio return while simultaneously minimizing the risk. Since, it is competing and conflicting non-smooth multi-objective optimization problem, this paper employed a multi-objective particle swarm optimization (MOPSO) based meta-heuristic technique to provide Pareto-optimal solution in a single simulation run. Using a case study of the PJM electricity market, the performance of the MVS portfolio theory based method and the classical MV method is compared. It has been found that the MVS portfolio theory based method can provide significantly better portfolios in the situation where non-normally distributed assets exist for trading. (author)

Multi-objective mean-variance-skewness model for generation portfolio allocation in electricity markets

International Nuclear Information System (INIS)

Pindoriya, N.M.; Singh, S.N.; Singh, S.K.

2010-01-01

This paper proposes an approach for generation portfolio allocation based on mean-variance-skewness (MVS) model which is an extension of the classical mean-variance (MV) portfolio theory, to deal with assets whose return distribution is non-normal. The MVS model allocates portfolios optimally by considering the maximization of both the expected return and skewness of portfolio return while simultaneously minimizing the risk. Since, it is competing and conflicting non-smooth multi-objective optimization problem, this paper employed a multi-objective particle swarm optimization (MOPSO) based meta-heuristic technique to provide Pareto-optimal solution in a single simulation run. Using a case study of the PJM electricity market, the performance of the MVS portfolio theory based method and the classical MV method is compared. It has been found that the MVS portfolio theory based method can provide significantly better portfolios in the situation where non-normally distributed assets exist for trading. (author)

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.

The Role of Task Complexity, Modality, and Aptitude in Narrative Task Performance

Science.gov (United States)

Kormos, Judit; Trebits, Anna

2012-01-01

The study reported in this paper investigated the relationship between components of aptitude and the fluency, lexical variety, syntactic complexity, and accuracy of performance in two types of written and spoken narrative tasks. We also addressed the question of how narrative performance varies in tasks of different cognitive complexity in the…

Structured Strategy for Implementation of the Teaching Portfolio Concept in Japan

Science.gov (United States)

Kurita, Kayoko

2013-01-01

This paper describes a strategy for successfully implementing the teaching portfolio in higher education institutions in Japan. The teaching portfolio has gained recognition in Japan in the last few years as an effective instrument for improving and showcasing teaching performance. It is well known that the implementation process is very important…

Valuation of large variable annuity portfolios: Monte Carlo simulation and synthetic datasets

Directory of Open Access Journals (Sweden)

Gan Guojun

2017-12-01

Full Text Available Metamodeling techniques have recently been proposed to address the computational issues related to the valuation of large portfolios of variable annuity contracts. However, it is extremely diffcult, if not impossible, for researchers to obtain real datasets frominsurance companies in order to test their metamodeling techniques on such real datasets and publish the results in academic journals. To facilitate the development and dissemination of research related to the effcient valuation of large variable annuity portfolios, this paper creates a large synthetic portfolio of variable annuity contracts based on the properties of real portfolios of variable annuities and implements a simple Monte Carlo simulation engine for valuing the synthetic portfolio. In addition, this paper presents fair market values and Greeks for the synthetic portfolio of variable annuity contracts that are important quantities for managing the financial risks associated with variable annuities. The resulting datasets can be used by researchers to test and compare the performance of various metamodeling techniques.

Bond Portfolio Allocations in South Africa Emerging Markets

Directory of Open Access Journals (Sweden)

Jinghua Wang

2016-03-01

Full Text Available Over the past fifty years, economic growth in emerging markets has been supported by investments in capital and technology from the developed world. The benefit of this development for the emerging markets, as measured by growth in income, employment, and wealth, is immediately apparent. There have also been significant advantages for the developed world through opportunities for higher risk adjusted returns from investments in emerging markets. This study explores the benefits of the diversification of global government bond portfolio, and provides complete performance evaluations of DMs with or without South Africa emerging market (SAEM bonds. The study examines the benefits of inclusion of SAEM bonds in DMs, the degrees of financial integration among the research markets, the relative bond returns of dynamic factor models with time-varying coefficients and the robust tests of bond portfolio performance between DMs with SAEM and bond index. The results of this study provide important implications for global investors by identifying diversification gains in SAEM.  Keywords: African Bond Market, Portfolio Diversification

Implicit and Explicit Knowledge Both Improve Dual Task Performance in a Continuous Pursuit Tracking Task.

Science.gov (United States)

Ewolds, Harald E; Bröker, Laura; de Oliveira, Rita F; Raab, Markus; Künzell, Stefan

2017-01-01

The goal of this study was to investigate the effect of predictability on dual-task performance in a continuous tracking task. Participants practiced either informed (explicit group) or uninformed (implicit group) about a repeated segment in the curves they had to track. In Experiment 1 participants practices the tracking task only, dual-task performance was assessed after by combining the tracking task with an auditory reaction time task. Results showed both groups learned equally well and tracking performance on a predictable segment in the dual-task condition was better than on random segments. However, reaction times did not benefit from a predictable tracking segment. To investigate the effect of learning under dual-task situation participants in Experiment 2 practiced the tracking task while simultaneously performing the auditory reaction time task. No learning of the repeated segment could be demonstrated for either group during the training blocks, in contrast to the test-block and retention test, where participants performed better on the repeated segment in both dual-task and single-task conditions. Only the explicit group improved from test-block to retention test. As in Experiment 1, reaction times while tracking a predictable segment were no better than reaction times while tracking a random segment. We concluded that predictability has a positive effect only on the predictable task itself possibly because of a task-shielding mechanism. For dual-task training there seems to be an initial negative effect of explicit instructions, possibly because of fatigue, but the advantage of explicit instructions was demonstrated in a retention test. This might be due to the explicit memory system informing or aiding the implicit memory system.

Portfolio: a prototype workstation for development and evaluation of tools for analysis and management of digital portal images

International Nuclear Information System (INIS)

Boxwala, Aziz A.; Chaney, Edward L.; Fritsch, Daniel S.; Friedman, Charles P.; Rosenman, Julian G.

1998-01-01

Purpose: The purpose of this investigation was to design and implement a prototype physician workstation, called PortFolio, as a platform for developing and evaluating, by means of controlled observer studies, user interfaces and interactive tools for analyzing and managing digital portal images. The first observer study was designed to measure physician acceptance of workstation technology, as an alternative to a view box, for inspection and analysis of portal images for detection of treatment setup errors. Methods and Materials: The observer study was conducted in a controlled experimental setting to evaluate physician acceptance of the prototype workstation technology exemplified by PortFolio. PortFolio incorporates a windows user interface, a compact kit of carefully selected image analysis tools, and an object-oriented data base infrastructure. The kit evaluated in the observer study included tools for contrast enhancement, registration, and multimodal image visualization. Acceptance was measured in the context of performing portal image analysis in a structured protocol designed to simulate clinical practice. The acceptability and usage patterns were measured from semistructured questionnaires and logs of user interactions. Results: Radiation oncologists, the subjects for this study, perceived the tools in PortFolio to be acceptable clinical aids. Concerns were expressed regarding user efficiency, particularly with respect to the image registration tools. Conclusions: The results of our observer study indicate that workstation technology is acceptable to radiation oncologists as an alternative to a view box for clinical detection of setup errors from digital portal images. Improvements in implementation, including more tools and a greater degree of automation in the image analysis tasks, are needed to make PortFolio more clinically practical

Appraisal, Coping, Task Performance, and Cardiovascular Responses during the Evaluated Speaking Task.

Science.gov (United States)

Baggett, H. Lane; And Others

1996-01-01

Appraisal, coping, task performance, and cardiovascular responses were examined among men high and low in speech anxiety who prepared and performed a speech under evaluative conditions. Speech-anxious men saw the task as more threatening. They were more stressed, anxious, distracted, and aware of their emotions, focused on the passage of time, and…

A General Framework for Portfolio Theory. Part I: theory and various models

OpenAIRE

Maier-Paape, Stanislaus; Zhu, Qiji Jim

2017-01-01

Utility and risk are two often competing measurements on the investment success. We show that efficient trade-off between these two measurements for investment portfolios happens, in general, on a convex curve in the two dimensional space of utility and risk. This is a rather general pattern. The modern portfolio theory of Markowitz [H. Markowitz, Portfolio Selection, 1959] and its natural generalization, the capital market pricing model, [W. F. Sharpe, Mutual fund performance , 1966] are spe...

A portfolio evaluation framework for air transportation improvement projects

Science.gov (United States)

Baik, Hyeoncheol

This thesis explores the application of portfolio theory to the Air Transportation System (ATS) improvement. The ATS relies on complexly related resources and different stakeholder groups. Moreover, demand for air travel is significantly increasing relative to capacity of air transportation. In this environment, improving the ATS is challenging. Many projects, which are defined as technologies or initiatives, for improvement have been proposed and some have been demonstrated in practice. However, there is no clear understanding of how well these projects work in different conditions nor of how they interact with each other or with existing systems. These limitations make it difficult to develop good project combinations, or portfolios that maximize improvement. To help address this gap, a framework for identifying good portfolios is proposed. The framework can be applied to individual projects or portfolios of projects. Projects or portfolios are evaluated using four different groups of factors (effectiveness, time-to-implement, scope of applicability, and stakeholder impacts). Portfolios are also evaluated in terms of interaction-determining factors (prerequisites, co-requisites, limiting factors, and amplifying factors) because, while a given project might work well in isolation, interdependencies between projects or with existing systems could result in lower overall performance in combination. Ways to communicate a portfolio to decision makers are also introduced. The framework is unique because (1) it allows using a variety of available data, and (2) it covers diverse benefit metrics. For demonstrating the framework, an application to ground delay management projects serves as a case study. The portfolio evaluation approach introduced in this thesis can aid decision makers and researchers at universities and aviation agencies such as Federal Aviation Administration (FAA), National Aeronautics and Space Administration (NASA), and Department of Defense (DoD), in

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.

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…

The modern portfolio theory applied to wind farm financing

Energy Technology Data Exchange (ETDEWEB)

Chaves-Schwinteck, P. [DEWI GmbH, Oldenburg (Germany)

2011-02-15

An alternative to the application of the principles of the Modern Portfolio Theory as a strategy to the reduction of the risks around the energy production of wind farms was presented in the last sections. The potential of geographical diversification to reduce the risks related to the availability of wind as a primary resource was demonstrated by the results of the first case study. Furthermore, the results of the second case study have shown that, once a sufficient history of technical performance data is available, a reduction of the risks linked to the technical performance of the wind turbines can be achieved in a similar way. Nevertheless, the existence of 'non-diversifiable' risks still presents a challenge for the financing of wind farms. In this sense, it is important to point out that the financing performance of a portfolio of wind farms is extremely dependent on the individual performance of the single projects. In other words, a portfolio analysis is not a miracle. A 'bad' project remains a 'bad' project even when this project is bundled with a 'good' one. For this reason, other risk management strategies, as for example, a well performed technical due diligence should be always taken into consideration. (orig.)

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...

Optimal Portfolio Strategy under Rolling Economic Maximum Drawdown Constraints

Directory of Open Access Journals (Sweden)

Xiaojian Yu

2014-01-01

Full Text Available This paper deals with the problem of optimal portfolio strategy under the constraints of rolling economic maximum drawdown. A more practical strategy is developed by using rolling Sharpe ratio in computing the allocation proportion in contrast to existing models. Besides, another novel strategy named “REDP strategy” is further proposed, which replaces the rolling economic drawdown of the portfolio with the rolling economic drawdown of the risky asset. The simulation tests prove that REDP strategy can ensure the portfolio to satisfy the drawdown constraint and outperforms other strategies significantly. An empirical comparison research on the performances of different strategies is carried out by using the 23-year monthly data of SPTR, DJUBS, and 3-month T-bill. The investment cases of single risky asset and two risky assets are both studied in this paper. Empirical results indicate that the REDP strategy successfully controls the maximum drawdown within the given limit and performs best in both return and risk.

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...

The Diversification Benefits of Including Carbon Assets in Financial Portfolios

Directory of Open Access Journals (Sweden)

Yinpeng Zhang

2017-03-01

Full Text Available Carbon allowances traded in the EU-Emission Trading Scheme (EU-ETS were initially designed as an economic motivation for efficiently curbing greenhouse as emissions, but now it mimics quite a few characteristics of financial assets, and have now been used as a candidate product in building financial portfolios. In this study, we examine the time-varying correlations between carbon allowance prices with other financial indices, during the third phase of EU-ETS. The results show that, at the beginning of this period, carbon price was still strongly corrected with other financial indices. However, this connection was weakened over time. Given the relative independence of carbon assets from other financial assets, we argue for the diversification benefits of including carbon assets in financial portfolios, and building such portfolios, respectively, with the traditional global minimum variance (GMV strategy, the mean-variance-OGARCH (MV-OGARCH strategy, and the dynamic conditional correlation (DCC strategy. It is shown that the portfolio built with the MV-OGARCH strategy far out-performs the others and that including carbon assets in financial portfolios does help reduce investment risks.

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.

On the importance of Task 1 and error performance measures in PRP dual-task studies

Science.gov (United States)

Strobach, Tilo; Schütz, Anja; Schubert, Torsten

2015-01-01

The psychological refractory period (PRP) paradigm is a dominant research tool in the literature on dual-task performance. In this paradigm a first and second component task (i.e., Task 1 and Task 2) are presented with variable stimulus onset asynchronies (SOAs) and priority to perform Task 1. The main indicator of dual-task impairment in PRP situations is an increasing Task 2-RT with decreasing SOAs. This impairment is typically explained with some task components being processed strictly sequentially in the context of the prominent central bottleneck theory. This assumption could implicitly suggest that processes of Task 1 are unaffected by Task 2 and bottleneck processing, i.e., decreasing SOAs do not increase reaction times (RTs) and error rates of the first task. The aim of the present review is to assess whether PRP dual-task studies included both RT and error data presentations and statistical analyses and whether studies including both data types (i.e., RTs and error rates) show data consistent with this assumption (i.e., decreasing SOAs and unaffected RTs and/or error rates in Task 1). This review demonstrates that, in contrast to RT presentations and analyses, error data is underrepresented in a substantial number of studies. Furthermore, a substantial number of studies with RT and error data showed a statistically significant impairment of Task 1 performance with decreasing SOA. Thus, these studies produced data that is not primarily consistent with the strong assumption that processes of Task 1 are unaffected by Task 2 and bottleneck processing in the context of PRP dual-task situations; this calls for a more careful report and analysis of Task 1 performance in PRP studies and for a more careful consideration of theories proposing additions to the bottleneck assumption, which are sufficiently general to explain Task 1 and Task 2 effects. PMID:25904890

On the importance of Task 1 and error performance measures in PRP dual-task studies.

Science.gov (United States)

Strobach, Tilo; Schütz, Anja; Schubert, Torsten

2015-01-01

The psychological refractory period (PRP) paradigm is a dominant research tool in the literature on dual-task performance. In this paradigm a first and second component task (i.e., Task 1 and Task 2) are presented with variable stimulus onset asynchronies (SOAs) and priority to perform Task 1. The main indicator of dual-task impairment in PRP situations is an increasing Task 2-RT with decreasing SOAs. This impairment is typically explained with some task components being processed strictly sequentially in the context of the prominent central bottleneck theory. This assumption could implicitly suggest that processes of Task 1 are unaffected by Task 2 and bottleneck processing, i.e., decreasing SOAs do not increase reaction times (RTs) and error rates of the first task. The aim of the present review is to assess whether PRP dual-task studies included both RT and error data presentations and statistical analyses and whether studies including both data types (i.e., RTs and error rates) show data consistent with this assumption (i.e., decreasing SOAs and unaffected RTs and/or error rates in Task 1). This review demonstrates that, in contrast to RT presentations and analyses, error data is underrepresented in a substantial number of studies. Furthermore, a substantial number of studies with RT and error data showed a statistically significant impairment of Task 1 performance with decreasing SOA. Thus, these studies produced data that is not primarily consistent with the strong assumption that processes of Task 1 are unaffected by Task 2 and bottleneck processing in the context of PRP dual-task situations; this calls for a more careful report and analysis of Task 1 performance in PRP studies and for a more careful consideration of theories proposing additions to the bottleneck assumption, which are sufficiently general to explain Task 1 and Task 2 effects.

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.

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.

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.

On the importance of Task 1 and error performance measures in PRP dual-task studies

Directory of Open Access Journals (Sweden)

Tilo eStrobach

2015-04-01

Full Text Available The Psychological Refractory Period (PRP paradigm is a dominant research tool in the literature on dual-task performance. In this paradigm a first and second component task (i.e., Task 1 and 2 are presented with variable stimulus onset asynchronies (SOAs and priority to perform Task 1. The main indicator of dual-task impairment in PRP situations is an increasing Task 2-RT with decreasing SOAs. This impairment is typically explained with some task components being processed strictly sequentially in the context of the prominent central bottleneck theory. This assumption could implicitly suggest that processes of Task 1 are unaffected by Task 2 and bottleneck processing, i.e. decreasing SOAs do not increase RTs and error rates of the first task. The aim of the present review is to assess whether PRP dual-task studies included both RT and error data presentations and statistical analyses and whether studies including both data types (i.e., RTs and error rates show data consistent with this assumption (i.e., decreasing SOAs and unaffected RTs and/ or error rates in Task 1. This review demonstrates that, in contrast to RT presentations and analyses, error data is underrepresented in a substantial number of studies. Furthermore, a substantial number of studies with RT and error data showed a statistically significant impairment of Task 1 performance with decreasing SOA. Thus, these studies produced data that is not primarily consistent with the strong assumption that processes of Task 1 are unaffected by Task 2 and bottleneck processing in the context of PRP dual-task situations; this calls for a more careful report and analysis of Task 1 performance in PRP studies and for a more careful consideration of theories proposing additions to the bottleneck assumption, which are sufficiently general to explain Task 1 and Task 2 effects.

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

Investment Portfolio Formation Using Multi-criteria evaluation Method MULTIMOORA

Directory of Open Access Journals (Sweden)

Vilius Vaišvilas

2017-06-01

Full Text Available Information that has to be analyzed by investors is complicated and can be interpreted differently by different people, which is why choosing what should be added to the investment portfolio is complicated task. Complexity grows substantially when there are more alternatives to choose from. Multi – criteria evaluation method can be used to choose the best alternatives. Multi–criteria evaluation method MULTIMOORA is not subjective because there is no need to decide ratio of any given variable that is evaluated. MULTIMOORA consists of: formation of ratio system, application of multi – criteria evaluation method as well as investment evaluation and ranking. Purpose of this article is to apply multi – criteria evaluation method MULTIMOORA for the formation and management of investment portfolio from stocks of the Baltic stock market companies. Methods used in the analysis for the article: analysis of scientific literature, statistical analysis, organization and comparison of data, idealization, calculations of MULTIMOORA.

Promoting Affordability in Defense Acquisitions: A Multi-Period Portfolio Approach

Science.gov (United States)

2014-04-30

has evolved out of many areas of research, ranging from economics to modern control theory (Powell, 2011). The general form of a dynamic programming...states 5 School of Aeronautics & Astronautics A Portfolio Approach: Background • Balance expected profit (performance) against risk ( variance ) in...investments (Markowitz 1952) • Efficiency frontier of optimal portfolios given investor risk averseness • Extends to multi-period case with various

A new enhanced index tracking model in portfolio optimization with sum weighted approach

Science.gov (United States)

Siew, Lam Weng; Jaaman, Saiful Hafizah; Hoe, Lam Weng

2017-04-01

Index tracking is a portfolio management which aims to construct the optimal portfolio to achieve similar return with the benchmark index return at minimum tracking error without purchasing all the stocks that make up the index. Enhanced index tracking is an improved portfolio management which aims to generate higher portfolio return than the benchmark index return besides minimizing the tracking error. The objective of this paper is to propose a new enhanced index tracking model with sum weighted approach to improve the existing index tracking model for tracking the benchmark Technology Index in Malaysia. The optimal portfolio composition and performance of both models are determined and compared in terms of portfolio mean return, tracking error and information ratio. The results of this study show that the optimal portfolio of the proposed model is able to generate higher mean return than the benchmark index at minimum tracking error. Besides that, the proposed model is able to outperform the existing model in tracking the benchmark index. The significance of this study is to propose a new enhanced index tracking model with sum weighted apporach which contributes 67% improvement on the portfolio mean return as compared to the existing model.

Impact of task design on task performance and injury risk: case study of a simulated drilling task.

Science.gov (United States)

Alabdulkarim, Saad; Nussbaum, Maury A; Rashedi, Ehsan; Kim, Sunwook; Agnew, Michael; Gardner, Richard

2017-06-01

Existing evidence is limited regarding the influence of task design on performance and ergonomic risk, or the association between these two outcomes. In a controlled experiment, we constructed a mock fuselage to simulate a drilling task common in aircraft manufacturing, and examined the effect of three levels of workstation adjustability on performance as measured by productivity (e.g. fuselage completion time) and quality (e.g. fuselage defective holes), and ergonomic risk as quantified using two common methods (rapid upper limb assessment and the strain index). The primary finding was that both productivity and quality significantly improved with increased adjustability, yet this occurred only when that adjustability succeeded in reducing ergonomic risk. Supporting the inverse association between ergonomic risk and performance, the condition with highest adjustability created the lowest ergonomic risk and the best performance while there was not a substantial difference in ergonomic risk between the other two conditions, in which performance was also comparable. Practitioner Summary: Findings of this study supported a causal relationship between task design and both ergonomic risk and performance, and that ergonomic risk and performance are inversely associated. While future work is needed under more realistic conditions and a broader population, these results may be useful for task (re)design and to help cost-justify some ergonomic interventions.

Successful healthcare programs and projects: organization portfolio management essentials.

Science.gov (United States)

Pickens, Scott; Solak, Jamie

2005-01-01

Many healthcare organization projects take more time and resources than planned and fail to deliver desired business outcomes. Healthcare IT is a major component of many projects and often undeservedly receives the blame for failure. Poor results are often not a result of faulty healthcare IT or poor project management or poor project execution alone. Many projects fail because of poor portfolio management--poor planning and management of the portfolio of initiatives designed to meet an organization's strategic goals. Because resources are limited, portfolio management enables organizations to more strategically allocate and manage their resources so care delivery, service delivery, and initiatives that advance organizations toward their strategic goals, including healthcare IT initiatives, can be accomplished at the levels of quality and service desired by an organization. Proper portfolio management is the essential foundation for program and project success and supports overall organization success. Without portfolio management, even programs and projects that execute flawlessly may not meet desired objectives. This article discusses the essential requirements for porfolio management. These include opportunity identification, return on investment (ROI) forecast, project prioritization, capacity planning (inclusive of human, financial, capital, and facilities resources), work scheduling, program and project management and execution, and project performance and value assessment. Portfolio management is essential to successful healthcare project execution. Theories are drawn from the Organizational Project Management Maturity Model (OPM3) work of the Project Management Institute and other leading strategy, planning, and organization change management research institutes.

Semantic modeling of portfolio assessment in e-learning environment

Directory of Open Access Journals (Sweden)

Lucila Romero

2017-01-01

Full Text Available In learning environment, portfolio is used as a tool to keep track of learner’s progress. Particularly, when it comes to e-learning, continuous assessment allows greater customization and efficiency in learning process and prevents students lost interest in their study. Also, each student has his own characteristics and learning skills that must be taken into account in order to keep learner`s interest. So, personalized monitoring is the key to guarantee the success of technology-based education. In this context, portfolio assessment emerge as the solution because is an easy way to allow teacher organize and personalize assessment according to students characteristic and need. A portfolio assessment can contain various types of assessment like formative assessment, summative assessment, hetero or self-assessment and use different instruments like multiple choice questions, conceptual maps, and essay among others. So, a portfolio assessment represents a compilation of all assessments must be solved by a student in a course, it documents progress and set targets. In previous work, it has been proposed a conceptual framework that consist of an ontology network named AOnet which is a semantic tool conceptualizing different types of assessments. Continuing that work, this paper presents a proposal to implement portfolios assessment in e-learning environments. The proposal consists of a semantic model that describes key components and relations of this domain to set the bases to develop a tool to generate, manage and perform portfolios assessment.

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

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.

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

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

Windfall profit in portfolio diversification? An empirical analysis of the potential benefits of renewable energy investments

Energy Technology Data Exchange (ETDEWEB)

Bruns, Frederik

2013-05-01

Modern Portfolio Theory is a theory which was introduced by Markowitz, and which suggests the building of a portfolio with assets that have low or, in the best case, negative correlation. In times of financial crises, however, the positive diversification effect of a portfolio can fail when Traditional Assets are highly correlated. Therefore, many investors search for Alternative Asset classes, such as Renewable Energies, that tend to perform independently from capital market performance. 'Windfall Profit in Portfolio Diversification?' discusses the potential role of Renewable Energy investments in an institutional investor's portfolio by applying the main concepts from Modern Portfolio Theory. Thereby, the empirical analysis uses a unique data set from one of the largest institutional investors in the field of Renewable Energies, including several wind and solar parks. The study received the Science Award 2012 of the German Alternative Investments Association ('Bundesverband Alternative Investments e.V.').

Optimizing Eco-Efficiency Across the Procurement Portfolio.

Science.gov (United States)

Pelton, Rylie E O; Li, Mo; Smith, Timothy M; Lyon, Thomas P

2016-06-07

Manufacturing organizations' environmental impacts are often attributable to processes in the firm's upstream supply chain. Environmentally preferable procurement (EPP) and the establishment of environmental purchasing criteria can potentially reduce these indirect impacts. Life-cycle assessment (LCA) can help identify the purchasing criteria that are most effective in reducing environmental impacts. However, the high costs of LCA and the problems associated with the comparability of results have limited efforts to integrate procurement performance with quantitative organizational environmental performance targets. Moreover, environmental purchasing criteria, when implemented, are often established on a product-by-product basis without consideration of other products in the procurement portfolio. We develop an approach that utilizes streamlined LCA methods, together with linear programming, to determine optimal portfolios of product impact-reduction opportunities under budget constraints. The approach is illustrated through a simulated breakfast cereal manufacturing firm procuring grain, containerboard boxes, plastic packaging, electricity, and industrial cleaning solutions. Results suggest that extending EPP decisions and resources to the portfolio level, recently made feasible through the methods illustrated herein, can provide substantially greater CO2e and water-depletion reductions per dollar spend than a product-by-product approach, creating opportunities for procurement organizations to participate in firm-wide environmental impact reduction targets.

From aggregation to interpretation: how assessors judge complex data in a competency-based portfolio.

Science.gov (United States)

Oudkerk Pool, Andrea; Govaerts, Marjan J B; Jaarsma, Debbie A D C; Driessen, Erik W

2018-05-01

While portfolios are increasingly used to assess competence, the validity of such portfolio-based assessments has hitherto remained unconfirmed. The purpose of the present research is therefore to further our understanding of how assessors form judgments when interpreting the complex data included in a competency-based portfolio. Eighteen assessors appraised one of three competency-based mock portfolios while thinking aloud, before taking part in semi-structured interviews. A thematic analysis of the think-aloud protocols and interviews revealed that assessors reached judgments through a 3-phase cyclical cognitive process of acquiring, organizing, and integrating evidence. Upon conclusion of the first cycle, assessors reviewed the remaining portfolio evidence to look for confirming or disconfirming evidence. Assessors were inclined to stick to their initial judgments even when confronted with seemingly disconfirming evidence. Although assessors reached similar final (pass-fail) judgments of students' professional competence, they differed in their information-processing approaches and the reasoning behind their judgments. Differences sprung from assessors' divergent assessment beliefs, performance theories, and inferences about the student. Assessment beliefs refer to assessors' opinions about what kind of evidence gives the most valuable and trustworthy information about the student's competence, whereas assessors' performance theories concern their conceptualizations of what constitutes professional competence and competent performance. Even when using the same pieces of information, assessors furthermore differed with respect to inferences about the student as a person as well as a (future) professional. Our findings support the notion that assessors' reasoning in judgment and decision-making varies and is guided by their mental models of performance assessment, potentially impacting feedback and the credibility of decisions. Our findings also lend further

Workplace for analysis of task performance

NARCIS (Netherlands)

Bos, J; Mulder, LJM; van Ouwerkerk, RJ; Maarse, FJ; Akkerman, AE; Brand, AN; Mulder, LJM

2003-01-01

In current research on mental workload and task performance a large gap exists between laboratory based studies and research projects in real life working practice. Tasks conducted within a laboratory environment often lack a strong resemblance with real life working situations. This paper presents

Pleasantness of Creative Tasks and Creative Performance

Science.gov (United States)

Zenasni, Franck; Lubart, Todd

2011-01-01

To examine the impact of emotion on creative potential, experimental studies have typically focused on the impact of induced or spontaneous mood states on creative performance. In this report the relationship between the perceived pleasantness of tasks (using divergent thinking and story writing tasks) and creative performance was examined.…

Differentiated risk models in portfolio optimization: a comparative analysis of the degree of diversification and performance in the São Paulo Stock Exchange (BOVESPA

Directory of Open Access Journals (Sweden)

Ivan Ricardo Gartner

2012-08-01

Full Text Available Faced with so many risk modeling alternatives in portfolio optimization, several questions arise regarding their legitimacy, utility and applicability. In particular, a question arises involving the adherence of the alternative models with regard to the basic presupposition of Markowitz's classical model, with regard to the concept of diversification as a means of controlling the relationship between risk and return within a process of optimization. In this context, the aim of this article is to explore the risk-differentiated configurations that entropy can provide, from the point of view of the repercussions that these have on the degree of diversification and on portfolios performance. The reach of this objective requires that a comparative analysis is made between models that include entropy in their formulation and the classic Markowitz model. In order to contribute to this debate, this article proposes that adaptations are made to the models of relative minimum entropy and of maximum entropy, so that these can be applied to investment portfolio optimizations. The comparative analysis was based on performance indicators and on a ratio of the degree of portfolio diversification. The portfolios were formed by considering a sample of fourteen assets that compose the IBOVESPA, which were projected during the period from January 2007 to December 2009, and took into account the matrices of covariance that were formed as from January 1999. When comparing the Markowitz model with two models that were constructed to represent new risk configurations based on entropy optimization, the present study concluded that the first model was far superior to the others. Not only did the Markowitz model present better accumulated nominal yields, it also presented a far greater predictive efficiency and better effective performance, when considering the trade-off between risk and return. However, with regards to diversification, the Markowitz model concentrated

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

When predictions take control: The effect of task predictions on task switching performance

Directory of Open Access Journals (Sweden)

Wout eDuthoo

2012-08-01

Full Text Available In this paper, we aimed to investigate the role of self-generated predictions in the flexible control of behaviour. Therefore, we ran a task switching experiment in which participants were asked to try to predict the upcoming task in three conditions varying in switch rate (30%, 50% and 70%. Irrespective of their predictions, the colour of the target indicated which task participants had to perform. In line with previous studies (Mayr, 2006; Monsell & Mizon, 2006, the switch cost was attenuated as the switch rate increased. Importantly, a clear task repetition bias was found in all conditions, yet the task repetition prediction rate dropped from 78% over 66% to 49% with increasing switch probability in the three conditions. Irrespective of condition, the switch cost was strongly reduced in expectation of a task alternation compared to the cost of an unexpected task alternation following repetition predictions. Hence, our data suggest that the reduction in the switch cost with increasing switch probability is caused by a diminished expectancy for the task to repeat. Taken together, this paper highlights the importance of predictions in the flexible control of behaviour, and suggests a crucial role for task repetition expectancy in the context-sensitive adjusting of task switching performance.

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

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...

Sleep deprivation and time-on-task performance decrement in the rat psychomotor vigilance task.

Science.gov (United States)

Oonk, Marcella; Davis, Christopher J; Krueger, James M; Wisor, Jonathan P; Van Dongen, Hans P A

2015-03-01

The rat psychomotor vigilance task (rPVT) was developed as a rodent analog of the human psychomotor vigilance task (hPVT). We examined whether rPVT performance displays time-on-task effects similar to those observed on the hPVT. The rPVT requires rats to respond to a randomly presented light stimulus to obtain a water reward. Rats were water deprived for 22 h prior to each 30-min rPVT session to motivate performance. We analyzed rPVT performance over time on task and as a function of the response-stimulus interval, at baseline and after sleep deprivation. The study was conducted in an academic research vivarium. Male Long-Evans rats were trained to respond to a 0.5 sec stimulus light within 3 sec of stimulus onset. Complete data were available for n = 20 rats. Rats performed the rPVT for 30 min at baseline and after 24 h total sleep deprivation by gentle handling. Compared to baseline, sleep deprived rats displayed increased performance lapses and premature responses, similar to hPVT lapses of attention and false starts. However, in contrast to hPVT performance, the time-on-task performance decrement was not significantly enhanced by sleep deprivation. Moreover, following sleep deprivation, rPVT response times were not consistently increased after short response-stimulus intervals. The rPVT manifests similarities to the hPVT in global performance outcomes, but not in post-sleep deprivation effects of time on task and response-stimulus interval. © 2015 Associated Professional Sleep Societies, LLC.

The cost of geothermal energy in the western US region:a portfolio-based approach a mean-variance portfolio optimization of the regions' generating mix to 2013.

Energy Technology Data Exchange (ETDEWEB)

Beurskens, Luuk (ECN-Energy Research Centre of the Netherland); Jansen, Jaap C. (ECN-Energy Research Centre of the Netherlands); Awerbuch, Shimon Ph.D. (.University of Sussex, Brighton, UK); Drennen, Thomas E.

2005-09-01

Energy planning represents an investment-decision problem. Investors commonly evaluate such problems using portfolio theory to manage risk and maximize portfolio performance under a variety of unpredictable economic outcomes. Energy planners need to similarly abandon their reliance on traditional, ''least-cost'' stand-alone technology cost estimates and instead evaluate conventional and renewable energy sources on the basis of their portfolio cost--their cost contribution relative to their risk contribution to a mix of generating assets. This report describes essential portfolio-theory ideas and discusses their application in the Western US region. The memo illustrates how electricity-generating mixes can benefit from additional shares of geothermal and other renewables. Compared to fossil-dominated mixes, efficient portfolios reduce generating cost while including greater renewables shares in the mix. This enhances energy security. Though counter-intuitive, the idea that adding more costly geothermal can actually reduce portfolio-generating cost is consistent with basic finance theory. An important implication is that in dynamic and uncertain environments, the relative value of generating technologies must be determined not by evaluating alternative resources, but by evaluating alternative resource portfolios. The optimal results for the Western US Region indicate that compared to the EIA target mixes, there exist generating mixes with larger geothermal shares at equal-or-lower expected cost and risk.

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

Big Data Challenges of High-Dimensional Continuous-Time Mean-Variance Portfolio Selection and a Remedy.

Science.gov (United States)

Chiu, Mei Choi; Pun, Chi Seng; Wong, Hoi Ying

2017-08-01

Investors interested in the global financial market must analyze financial securities internationally. Making an optimal global investment decision involves processing a huge amount of data for a high-dimensional portfolio. This article investigates the big data challenges of two mean-variance optimal portfolios: continuous-time precommitment and constant-rebalancing strategies. We show that both optimized portfolios implemented with the traditional sample estimates converge to the worst performing portfolio when the portfolio size becomes large. The crux of the problem is the estimation error accumulated from the huge dimension of stock data. We then propose a linear programming optimal (LPO) portfolio framework, which applies a constrained ℓ 1 minimization to the theoretical optimal control to mitigate the risk associated with the dimensionality issue. The resulting portfolio becomes a sparse portfolio that selects stocks with a data-driven procedure and hence offers a stable mean-variance portfolio in practice. When the number of observations becomes large, the LPO portfolio converges to the oracle optimal portfolio, which is free of estimation error, even though the number of stocks grows faster than the number of observations. Our numerical and empirical studies demonstrate the superiority of the proposed approach. © 2017 Society for Risk Analysis.

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...

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....

Exploring the role of task performance and learning style on prefrontal hemodynamics during a working memory task.

Science.gov (United States)

Anderson, Afrouz A; Parsa, Kian; Geiger, Sydney; Zaragoza, Rachel; Kermanian, Riley; Miguel, Helga; Dashtestani, Hadis; Chowdhry, Fatima A; Smith, Elizabeth; Aram, Siamak; Gandjbakhche, Amir H

2018-01-01

Existing literature outlines the quality and location of activation in the prefrontal cortex (PFC) during working memory (WM) tasks. However, the effects of individual differences on the underlying neural process of WM tasks are still unclear. In this functional near infrared spectroscopy study, we administered a visual and auditory n-back task to examine activation in the PFC while considering the influences of task performance, and preferred learning strategy (VARK score). While controlling for age, results indicated that high performance (HP) subjects (accuracy > 90%) showed task dependent lower activation compared to normal performance subjects in PFC region Specifically HP groups showed lower activation in left dorsolateral PFC (DLPFC) region during performance of auditory task whereas during visual task they showed lower activation in the right DLPFC. After accounting for learning style, we found a correlation between visual and aural VARK score and level of activation in the PFC. Subjects with higher visual VARK scores displayed lower activation during auditory task in left DLPFC, while those with higher visual scores exhibited higher activation during visual task in bilateral DLPFC. During performance of auditory task, HP subjects had higher visual VARK scores compared to NP subjects indicating an effect of learning style on the task performance and activation. The results of this study show that learning style and task performance can influence PFC activation, with applications toward neurological implications of learning style and populations with deficits in auditory or visual processing.

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...

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...

Computer task performance by subjects with Duchenne muscular dystrophy.

Science.gov (United States)

Malheiros, Silvia Regina Pinheiro; da Silva, Talita Dias; Favero, Francis Meire; de Abreu, Luiz Carlos; Fregni, Felipe; Ribeiro, Denise Cardoso; de Mello Monteiro, Carlos Bandeira

2016-01-01

Two specific objectives were established to quantify computer task performance among people with Duchenne muscular dystrophy (DMD). First, we compared simple computational task performance between subjects with DMD and age-matched typically developing (TD) subjects. Second, we examined correlations between the ability of subjects with DMD to learn the computational task and their motor functionality, age, and initial task performance. The study included 84 individuals (42 with DMD, mean age of 18±5.5 years, and 42 age-matched controls). They executed a computer maze task; all participants performed the acquisition (20 attempts) and retention (five attempts) phases, repeating the same maze. A different maze was used to verify transfer performance (five attempts). The Motor Function Measure Scale was applied, and the results were compared with maze task performance. In the acquisition phase, a significant decrease was found in movement time (MT) between the first and last acquisition block, but only for the DMD group. For the DMD group, MT during transfer was shorter than during the first acquisition block, indicating improvement from the first acquisition block to transfer. In addition, the TD group showed shorter MT than the DMD group across the study. DMD participants improved their performance after practicing a computational task; however, the difference in MT was present in all attempts among DMD and control subjects. Computational task improvement was positively influenced by the initial performance of individuals with DMD. In turn, the initial performance was influenced by their distal functionality but not their age or overall functionality.

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.

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…

Continuous Performance Tasks: Not Just about Sustaining Attention

Science.gov (United States)

Roebuck, Hettie; Freigang, Claudia; Barry, Johanna G.

2016-01-01

Purpose: Continuous performance tasks (CPTs) are used to measure individual differences in sustained attention. Many different stimuli have been used as response targets without consideration of their impact on task performance. Here, we compared CPT performance in typically developing adults and children to assess the role of stimulus processing…

Mean--variance portfolio optimization when means and covariances are unknown

OpenAIRE

Tze Leung Lai; Haipeng Xing; Zehao Chen

2011-01-01

Markowitz's celebrated mean--variance portfolio optimization theory assumes that the means and covariances of the underlying asset returns are known. In practice, they are unknown and have to be estimated from historical data. Plugging the estimates into the efficient frontier that assumes known parameters has led to portfolios that may perform poorly and have counter-intuitive asset allocation weights; this has been referred to as the "Markowitz optimization enigma." After reviewing differen...

Portfolio Optimization: A Combined Regime-Switching and Black–Litterman Model

OpenAIRE

Edwin O. Fischer; Immanuel Seidl

2013-01-01

Traditionally portfolios are optimized with the single-regime Markowitz model using the volatility as the risk measure and the historical return as the expected return. This study shows the effects that a regime-switching framework and alternative risk measures (modified value at risk and conditional value at risk) and return measures (CAPM estimates and Black–Litterman estimates) have on the asset allocation and on the absolute and relative performance of portfolios. It demonstrates that the...

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...

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

Conflicts in Coalitions: A Stability Analysis of Robust Multi-City Regional Water Supply Portfolios

Science.gov (United States)

Gold, D.; Trindade, B. C.; Reed, P. M.; Characklis, G. W.

2017-12-01

Regional cooperation among water utilities can improve the robustness of urban water supply portfolios to deeply uncertain future conditions such as those caused by climate change or population growth. Coordination mechanisms such as water transfers, coordinated demand management, and shared infrastructure, can improve the efficiency of resource allocation and delay the need for new infrastructure investments. Regionalization does however come at a cost. Regionally coordinated water supply plans may be vulnerable to any emerging instabilities in the regional coalition. If one or more regional actors does not cooperate or follow the required regional actions in a time of crisis, the overall system performance may degrade. Furthermore, when crafting regional water supply portfolios, decision makers must choose a framework for measuring the performance of regional policies based on the evaluation of the objective values for each individual actor. Regional evaluations may inherently favor one actor's interests over those of another. This work focuses on four interconnected water utilities in the Research Triangle region of North Carolina for which robust regional water supply portfolios have previously been designed using multi-objective optimization to maximize the robustness of the worst performing utility across several objectives. This study 1) examines the sensitivity of portfolio performance to deviations from prescribed actions by individual utilities, 2) quantifies the implications of the regional formulation used to evaluate robustness for the portfolio performance of each individual utility and 3) elucidates the inherent regional tensions and conflicts that exist between utilities under this regionalization scheme through visual diagnostics of the system under simulated drought scenarios. Results of this analysis will help inform the creation of future regional water supply portfolios and provide insight into the nature of multi-actor water supply systems.

[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.

Analysis of Skeletal Muscle Metrics as Predictors of Functional Task Performance

Science.gov (United States)

Ryder, Jeffrey W.; Buxton, Roxanne E.; Redd, Elizabeth; Scott-Pandorf, Melissa; Hackney, Kyle J.; Fiedler, James; Ploutz-Snyder, Robert J.; Bloomberg, Jacob J.; Ploutz-Snyder, Lori L.

2010-01-01

PURPOSE: The ability to predict task performance using physiological performance metrics is vital to ensure that astronauts can execute their jobs safely and effectively. This investigation used a weighted suit to evaluate task performance at various ratios of strength, power, and endurance to body weight. METHODS: Twenty subjects completed muscle performance tests and functional tasks representative of those that would be required of astronauts during planetary exploration (see table for specific tests/tasks). Subjects performed functional tasks while wearing a weighted suit with additional loads ranging from 0-120% of initial body weight. Performance metrics were time to completion for all tasks except hatch opening, which consisted of total work. Task performance metrics were plotted against muscle metrics normalized to "body weight" (subject weight + external load; BW) for each trial. Fractional polynomial regression was used to model the relationship between muscle and task performance. CONCLUSION: LPMIF/BW is the best predictor of performance for predominantly lower-body tasks that are ambulatory and of short duration. LPMIF/BW is a very practical predictor of occupational task performance as it is quick and relatively safe to perform. Accordingly, bench press work best predicts hatch-opening work performance.

A Maximum Entropy Method for a Robust Portfolio Problem

Directory of Open Access Journals (Sweden)

Yingying Xu

2014-06-01

Full Text Available We propose a continuous maximum entropy method to investigate the robustoptimal portfolio selection problem for the market with transaction costs and dividends.This robust model aims to maximize the worst-case portfolio return in the case that allof asset returns lie within some prescribed intervals. A numerical optimal solution tothe problem is obtained by using a continuous maximum entropy method. Furthermore,some numerical experiments indicate that the robust model in this paper can result in betterportfolio performance than a classical mean-variance model.

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.

Masticatory muscle activity during deliberately performed oral tasks

International Nuclear Information System (INIS)

Farella, M; Palla, S; Erni, S; Gallo, L M; Michelotti, A

2008-01-01

The aim of this study was to investigate masticatory muscle activity during deliberately performed functional and non-functional oral tasks. Electromyographic (EMG) surface activity was recorded unilaterally from the masseter, anterior temporalis and suprahyoid muscles in 11 subjects (5 men, 6 women; age = 34.6 ± 10.8 years), who were accurately instructed to perform 30 different oral tasks under computer guidance using task markers. Data were analyzed by descriptive statistics, repeated measurements analysis of variance (ANOVA) and hierarchical cluster analysis. The maximum EMG amplitude of the masseter and anterior temporalis muscles was more often found during hard chewing tasks than during maximum clenching tasks. The relative contribution of masseter and anterior temporalis changed across the tasks examined (F ≥ 5.2; p ≤ 0.001). The masseter muscle was significantly (p ≤ 0.05) more active than the anterior temporalis muscle during tasks involving incisal biting, jaw protrusion, laterotrusion and jaw cupping, the difference being statistically significant (p ≤ 0.05). The anterior temporalis muscle was significantly (p ≤ 0.01) more active than the masseter muscle during tasks performed in intercuspal position, during tooth grinding, and during hard chewing on the working side. Based upon the relative contribution of the masseter, anterior temporalis, and suprahyoid muscles, the investigated oral tasks could be grouped into six separate clusters. The findings provided further insight into muscle- and task-specific EMG patterns during functional and non-functional oral behaviors

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.

A proposed selection process in Over-The-Top project portfolio management

Directory of Open Access Journals (Sweden)

Jemy Vestius Confido

2018-05-01

Full Text Available Purpose: The purpose of this paper is to propose an Over-The-Top (OTT initiative selection process for communication service providers (CSPs entering an OTT business. Design/methodology/approach: To achieve this objective, a literature review was conducted to comprehend the past and current practices of the project (or initiative selection process as mainly suggested in project portfolio management (PPM. This literature was compared with specific situations and the needs of CSPs when constructing an OTT portfolio. Based on the contrast between the conventional project selection process and specific OTT characteristics, a different selection process is developed and tested using group model-building (GMB, which involved an in-depth interview, a questionnaire and a focus group discussion (FGD. Findings: The paper recommends five distinct steps for CSPs to construct an OTT initiative portfolio: candidate list of OTT initiatives, interdependency diagram, evaluation of all interdependent OTT initiatives, evaluation of all non-interdependent OTT initiatives and optimal portfolio of OTT initiatives. Research limitations/implications: The research is empirical, and various OTT services are implemented; the conclusion is derived only from one CSP, which operates as a group. Generalization of this approach will require further empirical tests on different CSPs, OTT players or any firms performing portfolio selection with a degree of interdependency among the projects. Practical implications: Having considered interdependency, the proposed OTT initiative selection steps can be further implemented by portfolio managers for more effective OTT initiative portfolio construction. Originality/value: While the previous literature and common practices suggest ensuring the benefits (mainly financial of individual projects, this research accords higher priority to the success of the overall OTT initiative portfolio and recommends that an evaluation of the overall

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...

Priming performance-related concerns induces task-related mind-wandering.

Science.gov (United States)

Jordano, Megan L; Touron, Dayna R

2017-10-01

Two experiments tested the hypothesis that priming of performance-related concerns would (1) increase the frequency of task-related mind-wandering (i.e., task-related interference; TRI) and (2) decrease task performance. In each experiment, sixty female participants completed an operation span task (OSPAN) containing thought content probes. The task was framed as a math task for those in a condition primed for math-related stereotype threat and as a memory task for those in a control condition. In both studies, women whose performance-related concerns were primed via stereotype threat reported more TRI than women in the control. The second experiment used a more challenging OSPAN task and stereotype primed women also had lower math accuracy than controls. These results support the "control failures×current concerns" framework of mind-wandering, which posits that the degree to which the environmental context triggers personal concerns influences both mind-wandering frequency and content. Copyright © 2017 Elsevier Inc. All rights reserved.

2018 DOE Solid-State Lighting Project Portfolio

Energy Technology Data Exchange (ETDEWEB)

None

2018-01-31

The 2018 Solid-State Lighting Project Portfolio provides an overview of all SSL projects that have been funded by DOE since 2000. Projects that were active during 2017 are found in the main body of this report, and all historic projects can be found in the appendix. Within these sections, project profiles are sorted by technology type (i.e., LED or OLED) and then by performer name. A profile is provided on each project. Each profile includes a brief technical description, as well as information about project partners, funding, and the research period. This report is updated annually, although the research described in the Portfolio changes periodically as new projects are initiated and existing ones are concluded.

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...

Is Learner Self-Assessment Reliable and Valid in a Web-Based Portfolio Environment for High School Students?

Science.gov (United States)

Chang, Chi-Cheng; Liang, Chaoyun; Chen, Yi-Hui

2013-01-01

This study explored the reliability and validity of Web-based portfolio self-assessment. Participants were 72 senior high school students enrolled in a computer application course. The students created learning portfolios, viewed peers' work, and performed self-assessment on the Web-based portfolio assessment system. The results indicated: 1)…

Within-person relationship between self-efficacy and performance across trials. Effect of task objective and task type.

Science.gov (United States)

Hepler, Teri J; Ritchie, Jason; Hill, Christopher R

2017-07-05

Self-efficacy has been shown to be a consistent, positive predictor of between-persons performance in sport. However, there have been equivocal results regarding the influence of self-efficacy on a person's performance over time. This study investigated the influence of self-efficacy on motor skill performance across trials with respect to two different task objectives and task types. Participants (N=84) performed 4 blocks of 10 trials of a dart throwing (closed skill) and a hitting (open skill) task under 2 different task objectives: competitive and goal-striving. For the goal-striving condition, success was defined as reaching a pre-determined performance level. The competitive condition involved competing against an opponent. Hierarchical linear modeling was used to examine the influence of past performance and self-efficacy on the within-person performance across multiple trials. Previous performance was negatively related with subsequent performance on all conditions. Self-efficacy was not a significant predictor of performance on any of the conditions. While task objective and task type did not moderate the efficacy-performance relationship in the current study, it is important to consider the role of other moderators in future research.

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

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.

Cognitive and motor dual task gait training improve dual task gait performance after stroke - A randomized controlled pilot trial.

Science.gov (United States)

Liu, Yan-Ci; Yang, Yea-Ru; Tsai, Yun-An; Wang, Ray-Yau

2017-06-22

This study investigated effects of cognitive and motor dual task gait training on dual task gait performance in stroke. Participants (n = 28) were randomly assigned to cognitive dual task gait training (CDTT), motor dual task gait training (MDTT), or conventional physical therapy (CPT) group. Participants in CDTT or MDTT group practiced the cognitive or motor tasks respectively during walking. Participants in CPT group received strengthening, balance, and gait training. The intervention was 30 min/session, 3 sessions/week for 4 weeks. Three test conditions to evaluate the training effects were single walking, walking while performing cognitive task (serial subtraction), and walking while performing motor task (tray-carrying). Parameters included gait speed, dual task cost of gait speed (DTC-speed), cadence, stride time, and stride length. After CDTT, cognitive-motor dual task gait performance (stride length and DTC-speed) was improved (p = 0.021; p = 0.015). After MDTT, motor dual task gait performance (gait speed, stride length, and DTC-speed) was improved (p = 0.008; p = 0.008; p = 0.008 respectively). It seems that CDTT improved cognitive dual task gait performance and MDTT improved motor dual task gait performance although such improvements did not reach significant group difference. Therefore, different types of dual task gait training can be adopted to enhance different dual task gait performance in stroke.

Currency Hedging for International Stock Portfolios : A General Approach

NARCIS (Netherlands)

de Roon, F.A.; Nijman, T.E.; Werker, B.J.M.

1999-01-01

This 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 auxiliary

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…

Self-Efficacy, Task Complexity and Task Performance: Exploring Interactions in Two Versions of Vocabulary Learning Tasks

Science.gov (United States)

Wu, Xiaoli; Lowyck, Joost; Sercu, Lies; Elen, Jan

2012-01-01

The present study aimed for better understanding of the interactions between task complexity and students' self-efficacy beliefs and students' use of learning strategies, and finally their interacting effects on task performance. This investigation was carried out in the context of Chinese students learning English as a foreign language in a…

Equity portfolio optimization: A DEA based methodology applied to the Zagreb Stock Exchange

Directory of Open Access Journals (Sweden)

Margareta Gardijan

2015-10-01

Full Text Available Most strategies for selection portfolios focus on utilizing solely market data and implicitly assume that stock markets communicate all relevant information to all market stakeholders, and that these markets cannot be influenced by investor activities. However convenient, this is a limited approach, especially when applied to small and illiquid markets such as the Croatian market, where such assumptions are hardly realistic. Thus, there is a demand for including other sources of data, such as financial reports. Research poses the question of whether financial ratios as criteria for stock selection are of any use to Croatian investors. Financial and market data from selected publicly companies listed on the Croatian capital market are used. A two-stage portfolio selection strategy is applied, where the first stage involves selecting stocks based on the respective Data Envelopment Analysis (DEA efficiency scores. DEA models are becoming popular in stock portfolio selection given that the methodology includes numerous models that provide a great flexibility in selecting inputs and outputs, which in turn are considered as criteria for portfolio selection. Accordingly, there is much room for improvement of the current proposed strategies for selecting portfolios. In the second stage, two portfolio-weighting strategies are applied using equal proportions and score-weighting. To show whether these strategies create outstanding out–of–sample portfolios in time, time-dependent DEA Window Analysis is applied using a reference time of one year, and portfolio returns are compared with the market portfolio for each period. It is found that the financial data are a significant indicator of the future performance of a stock and a DEA-based portfolio strategy outperforms market return.

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.

Portfolio optimization problem with nonidentical variances of asset returns using statistical mechanical informatics

Science.gov (United States)

Shinzato, Takashi

2016-12-01

The portfolio optimization problem in which the variances of the return rates of assets are not identical is analyzed in this paper using the methodology of statistical mechanical informatics, specifically, replica analysis. We defined two characteristic quantities of an optimal portfolio, namely, minimal investment risk and investment concentration, in order to solve the portfolio optimization problem and analytically determined their asymptotical behaviors using replica analysis. Numerical experiments were also performed, and a comparison between the results of our simulation and those obtained via replica analysis validated our proposed method.

Holistic and Individualistic Evaluations of Digital Visual Art Portfolios: A Mixed Methods Study

Science.gov (United States)

Cavill, William D., Jr.

2017-01-01

The high-stakes nature of portfolio evaluation makes it necessary to perform such assessments in the fairest and most equitable manner possible. Determining whether or not there is a difference between holistically and individualistically derived scores for digital visual art portfolios and how those differences can be explained was the focus of…

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.

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.

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...

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...

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...

Effects of cues in a binary categorization task on dual-task performance, mental workload, and effort.

Science.gov (United States)

Botzer, Assaf; Meyer, Joachim; Parmet, Yisrael

2016-09-01

Binary cues help operators perform binary categorization tasks, such as monitoring for system failures. They may also allow them to attend to other tasks they concurrently perform. If the time saved by using cues is allocated to other concurrent tasks, users' overall effort may remain unchanged. In 2 experiments, participants performed a simulated quality control task, together with a tracking task. In half the experimental blocks cues were available, and participants could use them in their decisions about the quality of products (intact or faulty). In Experiment 1, the difficulty of tracking was constant, while in Experiment 2, tracking difficulty differed in the 2 halves of the experiment. In both experiments, participants reported on the NASA Task Load Index that cues improved their performance and reduced their frustration. Consequently, their overall score on mental workload (MWL) was lower with cues. They also reported, however, that cues did not reduce their effort. We conclude that cues and other forms of automation may support task performance and reduce overall MWL, but this will not necessarily mean that users will work less hard. Thus, effort and overall MWL should be evaluated separately, if one wants to obtain a full picture of the effects of automation. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Effective Stock Selection and Portfolio Construction Within US, International, and Emerging Markets

Directory of Open Access Journals (Sweden)

Bijan Beheshti

2018-05-01

Full Text Available In this paper, we explore the ex-post attributes of 120 simulated portfolios across the U.S., International, and Emerging Markets. We estimate expected returns using a given global stock selection model employing Global Equity Rating (GLER and Consensus Temporary Earnings Forecasting (CTEF signals. Our portfolios are constructed under the Markowitz optimization framework and constrained at various tracking error levels. Further, an alpha alignment factor is applied to aid in portfolio construction. As a result of our research, we present the reader with three key findings. First, GLER and CTEF signals employed as the primary inputs to security selection result in portfolios with superior risk adjusted returns relative to the Russell 3000, MSCI AC World ex. US, and MSCI Emerging Markets benchmarks which they are measured against. Second, expanding the investment universe outside the U.S. increases the opportunity set yielding higher risk adjusted performance. Third, the incorporation of an alpha alignment factor within the portfolio construction process improves risk forecasts resulting in ex-post tracking error aligning more closely to ex-ante, and ultimately improving information ratios.

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....

The impact of task characteristics on the performance of nursing teams

Directory of Open Access Journals (Sweden)

Azlyn Ahmad Zawawi, PhD

2017-07-01

Conclusions: This study demonstrated that task significance is important to predict team task performance. Task significance reflects meaningfulness and nobility of tasks, thus elevate the desire to perform better in each assigned task.

Musical training, bilingualism, and executive function: a closer look at task switching and dual-task performance.

Science.gov (United States)

Moradzadeh, Linda; Blumenthal, Galit; Wiseheart, Melody

2015-07-01

This study investigated whether musical training and bilingualism are associated with enhancements in specific components of executive function, namely, task switching and dual-task performance. Participants (n = 153) belonging to one of four groups (monolingual musician, bilingual musician, bilingual non-musician, or monolingual non-musician) were matched on age and socioeconomic status and administered task switching and dual-task paradigms. Results demonstrated reduced global and local switch costs in musicians compared with non-musicians, suggesting that musical training can contribute to increased efficiency in the ability to shift flexibly between mental sets. On dual-task performance, musicians also outperformed non-musicians. There was neither a cognitive advantage for bilinguals relative to monolinguals, nor an interaction between music and language to suggest additive effects of both types of experience. These findings demonstrate that long-term musical training is associated with improvements in task switching and dual-task performance. Copyright © 2014 Cognitive Science Society, Inc.

Navigating financial and supply reliability tradeoffs in regional drought management portfolios

Science.gov (United States)

Zeff, Harrison B.; Kasprzyk, Joseph R.; Herman, Jonathan D.; Reed, Patrick M.; Characklis, Gregory W.

2014-06-01

Rising development costs and growing concerns over environmental impacts have led many communities to explore more diversified water management strategies. These "portfolio"-style approaches integrate existing supply infrastructure with other options such as conservation measures or water transfers. Diversified water supply portfolios have been shown to reduce the capacity and costs required to meet demand, while also providing greater adaptability to changing hydrologic conditions. However, this additional flexibility can also cause unexpected reductions in revenue (from conservation) or increased costs (from transfers). The resulting financial instability can act as a substantial disincentive to utilities seeking to implement more innovative water management techniques. This study seeks to design portfolios that employ financial tools (e.g., contingency funds and index insurance) to reduce fluctuations in revenues and costs, allowing these strategies to achieve improved performance without sacrificing financial stability. This analysis is applied to the development of coordinated regional supply portfolios in the "Research Triangle" region of North Carolina, an area comprising four rapidly growing municipalities. The actions of each independent utility become interconnected when shared infrastructure is utilized to enable interutility transfers, requiring the evaluation of regional tradeoffs in up to five performance and financial objectives. Diversified strategies introduce significant tradeoffs between achieving reliability goals and introducing burdensome variability in annual revenues and/or costs. Financial mitigation tools can mitigate the impacts of this variability, allowing for an alternative suite of improved solutions. This analysis provides a general template for utilities seeking to navigate the tradeoffs associated with more flexible, portfolio-style management approaches.

Effect of pre-task music on sports or exercise performance.

Science.gov (United States)

Smirmaul, Bruno P

2017-01-01

Pre-task music is a very common strategy among sports competitors. However, as opposed to in-task music, the scientific evidence to support its ergogenic effects on either sports or exercise performance is limited. This brief review critically addresses the existing literature investigating the effects of pre-task music on sports and exercise performance, focusing on the methods and results of experimental studies, and offers basic and practical recommendations. In July 2015, a comprehensive literature search was performed in Web of Science, PubMed, and Google Scholar using the following key words in combination: "pre-task music," "pre-test music," "pre-exercise music," "exercise performance," "sports performance." The literature search was further expanded by both hand searching review articles on the topic and by searching the reference lists from the articles retrieved for any relevant references. Overall, a total of 15 studies in 14 articles were included. Pre-task music research has been unsystematic, methodologically limited and infrequent. Using this review as a starting point to overcome previous methodological limitations when designing future experiments may contribute to the development of pre-task music research, which is still in its infancy. Currently, there is no sufficient evidence to support the overall ergogenic effects of pre-task music on sports or exercise performance. Nonetheless, pre-task music has showed a likely ergogenic effect on shorter and predominantly anaerobic tasks such as grip strength, Wingate test, and short-duration sports or sports-like tasks, in contrast to longer and predominantly aerobic tasks.

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…

Ability Beliefs, Task Value, and Performance as a Function of Race in a Dart-Throwing Task

Science.gov (United States)

Gao, Zan; Kosma, Maria; Harrison, Louis, Jr.

2009-01-01

This study examines differences in self-efficacy, expectancy-related beliefs, task value, and performance in a dart-throwing task as a function of race among diverse college students using the expectancy-value model and self-efficacy theory. It also examines the predictive contributions of these beliefs on task performance within each racial…

Training improves laparoscopic tasks performance and decreases operator workload.

Science.gov (United States)

Hu, Jesse S L; Lu, Jirong; Tan, Wee Boon; Lomanto, Davide

2016-05-01

It has been postulated that increased operator workload during task performance may increase fatigue and surgical errors. The National Aeronautics and Space Administration-Task Load Index (NASA-TLX) is a validated tool for self-assessment for workload. Our study aims to assess the relationship of workload and performance of novices in simulated laparoscopic tasks of different complexity levels before and after training. Forty-seven novices without prior laparoscopic experience were recruited in a trial to investigate whether training improves task performance as well as mental workload. The participants were tested on three standard tasks (ring transfer, precision cutting and intracorporeal suturing) in increasing complexity based on the Fundamentals of Laparoscopic Surgery (FLS) curriculum. Following a period of training and rest, participants were tested again. Test scores were computed from time taken and time penalties for precision errors. Test scores and NASA-TLX scores were recorded pre- and post-training and analysed using paired t tests. One-way repeated measures ANOVA was used to analyse differences in NASA-TLX scores between the three tasks. NASA-TLX score was lowest with ring transfer and highest with intracorporeal suturing. This was statistically significant in both pre-training (p NASA-TLX scores mirror the changes in test scores for the three tasks. Workload scores decreased significantly after training for all three tasks (ring transfer = 2.93, p NASA-TLX score is an accurate reflection of the complexity of simulated laparoscopic tasks in the FLS curriculum. This also correlates with the relationship of test scores between the three tasks. Simulation training improves both performance score and workload score across the tasks.

Construct validation of teacher portfolio assessment : Procedures for improving teacher competence assessment illustrated by teaching students research skills

NARCIS (Netherlands)

Schaaf, M.F. van der

2005-01-01

The study aims to design and test procedures for teacher portfolio assessments. What are suitable procedures to assess teachers' competencies in developing students' research skills? We first searched into the tasks teachers have in teaching students research skills and the competencies needed to

Teacher Portfolios: An Effective Way to Assess Teacher Performance and Enhance Learning

Science.gov (United States)

Gelfer, Jeff; 'O' Hara, Katie; Krasch, Delilah; Nguyen, Neal

2015-01-01

Often administrators seek alternative methods of evaluating staff while staff are frequently searching for methods to represent the breadth and quality of their efforts. One method proving to be effective for gathering and organising products of teacher activity is the portfolio. This article will discuss the procedures that teachers can apply in…

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.

Alliance Concentration in Multinational Companies : Examining Alliance Portfolios, Firm Structure, and Firm Performance

NARCIS (Netherlands)

Bos, Brenda; Faems, Dries; Noseleit, Florian

Research summary: This article explores the distribution of alliances across firms' internal structure. Focusing on multinational companies, we examine the impact of alliance portfolio concentrationi.e., the extent to which alliances are concentrated within a limited number of geographic unitson

Alliance Concentration in Multinational Companies : Examining Alliance Portfolios, Firm Structure, and Firm Performance

NARCIS (Netherlands)

Bos, Brenda; Faems, Dries; Noseleit, Florian

2017-01-01

Research summary: This article explores the distribution of alliances across firms' internal structure. Focusing on multinational companies, we examine the impact of alliance portfolio concentrationi.e., the extent to which alliances are concentrated within a limited number of geographic unitson

Model to Estimate Monthly Time Horizons for Application of DEA in Selection of Stock Portfolio and for Maintenance of the Selected Portfolio

Directory of Open Access Journals (Sweden)

José Claudio Isaias

2015-01-01

Full Text Available In the selecting of stock portfolios, one type of analysis that has shown good results is Data Envelopment Analysis (DEA. It, however, has been shown to have gaps regarding its estimates of monthly time horizons of data collection for the selection of stock portfolios and of monthly time horizons for the maintenance of a selected portfolio. To better estimate these horizons, this study proposes a model of mathematical programming binary of minimization of square errors. This model is the paper’s main contribution. The model’s results are validated by simulating the estimated annual return indexes of a portfolio that uses both horizons estimated and of other portfolios that do not use these horizons. The simulation shows that portfolios with both horizons estimated have higher indexes, on average 6.99% per year. The hypothesis tests confirm the statistically significant superiority of the results of the proposed mathematical model’s indexes. The model’s indexes are also compared with portfolios that use just one of the horizons estimated; here the indexes of the dual-horizon portfolios outperform the single-horizon portfolios, though with a decrease in percentage of statistically significant superiority.

ALPHA-BETA SEPARATION PORTFOLIO STRATEGIES FOR ISLAMIC FINANCE

Directory of Open Access Journals (Sweden)

Valentyn Khokhlov

2016-11-01

Full Text Available 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-variance optimization strategy. Results of the portfolio dynamics clearly show that a significant amount of value was created by alpha-beta separation. The typical alpha ranges from 4% to 5.7%. The most aggressive portfolio strategies that allow short positions in the satellite portfolio work best with frequent rebalancing and benefit from the active bets. Smoothing technique that was introduced to decrease the portfolio turnover and stabilize its composition works better when active bets are less efficient, particularly with less frequent rebalancing. The best risk-return combinations are achieved with modest (3% to 10% allocation of the total portfolio to the satellite, and the remaining part (90% to 97% being managed in order to minimize the tracking error. Practical implications. The alpha-beta separation framework suggested in this paper can be used to enhance the portfolio management techniques for the hedge funds that operate under tight restrictions, particularly under the Islamic finance principles. The mathematical models developed in this paper allow practical implementation of the alphabeta separation concept. Originality/value. While the idea of alpha-beta separation existed in hedge fund management before, there was no comprehensive mathematical model under it, so its implementation was based on the ad hoc approach. This paper introduces such a mathematical model and demonstrates how portfolio managers can create value for their clients using it.

Optimization Stock Portfolio With Mean-Variance and Linear Programming: Case In Indonesia Stock Market

Directory of Open Access Journals (Sweden)

Yen Sun

2010-05-01

Full Text Available It is observed that the number of Indonesia’s domestic investor who involved in the stock exchange is very less compare to its total number of population (only about 0.1%. As a result, Indonesia Stock Exchange (IDX is highly affected by foreign investor that can threat the economy. Domestic investor tends to invest in risk-free asset such as deposit in the bank since they are not familiar yet with the stock market and anxious about the risk (risk-averse type of investor. Therefore, it is important to educate domestic investor to involve in the stock exchange. Investing in portfolio of stock is one of the best choices for risk-averse investor (such as Indonesia domestic investor since it offers lower risk for a given level of return. This paper studies the optimization of Indonesian stock portfolio. The data is the historical return of 10 stocks of LQ 45 for 5 time series (January 2004 – December 2008. It will be focus on selecting stocks into a portfolio, setting 10 of stock portfolios using mean variance method combining with the linear programming (solver. Furthermore, based on Efficient Frontier concept and Sharpe measurement, there will be one stock portfolio picked as an optimum Portfolio (Namely Portfolio G. Then, Performance of portfolio G will be evaluated by using Sharpe, Treynor and Jensen Measurement to show whether the return of Portfolio G exceeds the market return. This paper also illustrates how the stock composition of the Optimum Portfolio (G succeeds to predict the portfolio return in the future (5th January – 3rd April 2009. The result of the study observed that optimization portfolio using Mean-Variance (consistent with Markowitz theory combine with linear programming can be applied into Indonesia stock’s portfolio. All the measurements (Sharpe, Jensen, and Treynor show that the portfolio G is a superior portfolio. It is also been found that the composition (weights stocks of optimum portfolio (G can be used to

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...

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…

Analysis on the cost performance and its impact to Japanese electric utilities and vision of the power portfolio

International Nuclear Information System (INIS)

Yamaguchi, Yuji; Matsuo, Yuji; Murakami, Tomoko

2013-01-01

Most of the nuclear power plants in Japan have been shut down since the Fukushima accident in March 2011, without being permitted to restart after periodical inspections. Accordingly, thermal power generation significantly increased in FY 2011. In this paper the authors made a quantitative analysis on the unit costs of power generation and on the financial performance based on the financial reports of electric utilities. The average unit cost in FY 2011 rose to 11.6 JPY/kWh, 3 JPY/kWh higher than that in FY 2010, and will rise further to 12.6 JPY/kWh in FY 2012. The total retained profit of 8 utilities decreased by some 1 trillion JPY from FY 2010 to FY 2011 and will decrease further to 1 trillion JPY by the end of FY 2012, which is the lowest level in history. Clear decisions on energy policies and future power portfolio, as well as the restructuring of the electricity system in line with the rapid change in the power portfolio will be highly required for policy planners in Japan. (author)

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...

Improving Physical Task Performance with Counterfactual and Prefactual Thinking.

Science.gov (United States)

Hammell, Cecilia; Chan, Amy Y C

2016-01-01

Counterfactual thinking (reflecting on "what might have been") has been shown to enhance future performance by translating information about past mistakes into plans for future action. Prefactual thinking (imagining "what might be if…") may serve a greater preparative function than counterfactual thinking as it is future-orientated and focuses on more controllable features, thus providing a practical script to prime future behaviour. However, whether or not this difference in hypothetical thought content may translate into a difference in actual task performance has been largely unexamined. In Experiment 1 (n = 42), participants performed trials of a computer-simulated physical task, in between which they engaged in either task-related hypothetical thinking (counterfactual or prefactual) or an unrelated filler task (control). As hypothesised, prefactuals contained more controllable features than counterfactuals. Moreover, participants who engaged in either form of hypothetical thinking improved significantly in task performance over trials compared to participants in the control group. The difference in thought content between counterfactuals and prefactuals, however, did not yield a significant difference in performance improvement. Experiment 2 (n = 42) replicated these findings in a dynamic balance task environment. Together, these findings provide further evidence for the preparatory function of counterfactuals, and demonstrate that prefactuals share this same functional characteristic.

Hysteresis in Mental Workload and Task Performance: The Influence of Demand Transitions and Task Prioritization.

Science.gov (United States)

Jansen, Reinier J; Sawyer, Ben D; van Egmond, René; de Ridder, Huib; Hancock, Peter A

2016-12-01

We examine how transitions in task demand are manifested in mental workload and performance in a dual-task setting. Hysteresis has been defined as the ongoing influence of demand levels prior to a demand transition. Authors of previous studies predominantly examined hysteretic effects in terms of performance. However, little is known about the temporal development of hysteresis in mental workload. A simulated driving task was combined with an auditory memory task. Participants were instructed to prioritize driving or to prioritize both tasks equally. Three experimental conditions with low, high, and low task demands were constructed by manipulating the frequency of lane changing. Multiple measures of subjective mental workload were taken during experimental conditions. Contrary to our prediction, no hysteretic effects were found after the high- to low-demand transition. However, a hysteretic effect in mental workload was found within the high-demand condition, which degraded toward the end of the high condition. Priority instructions were not reflected in performance. Online assessment of both performance and mental workload demonstrates the transient nature of hysteretic effects. An explanation for the observed hysteretic effect in mental workload is offered in terms of effort regulation. An informed arrival at the scene is important in safety operations, but peaks in mental workload should be avoided to prevent buildup of fatigue. Therefore, communication technologies should incorporate the historical profile of task demand. © 2016, Human Factors and Ergonomics Society.

On Two Mixture-Based Clustering Approaches Used in Modeling an Insurance Portfolio

Directory of Open Access Journals (Sweden)

Tatjana Miljkovic

2018-05-01

Full Text Available We review two complementary mixture-based clustering approaches for modeling unobserved heterogeneity in an insurance portfolio: the generalized linear mixed cluster-weighted model (CWM and mixture-based clustering for an ordered stereotype model (OSM. The latter is for modeling of ordinal variables, and the former is for modeling losses as a function of mixed-type of covariates. The article extends the idea of mixture modeling to a multivariate classification for the purpose of testing unobserved heterogeneity in an insurance portfolio. The application of both methods is illustrated on a well-known French automobile portfolio, in which the model fitting is performed using the expectation-maximization (EM algorithm. Our findings show that these mixture-based clustering methods can be used to further test unobserved heterogeneity in an insurance portfolio and as such may be considered in insurance pricing, underwriting, and risk management.

Training Attentional Control Improves Cognitive and Motor Task Performance.

Science.gov (United States)

Ducrocq, Emmanuel; Wilson, Mark; Vine, Sam; Derakshan, Nazanin

2016-10-01

Attentional control is a necessary function for the regulation of goal-directed behavior. In three experiments we investigated whether training inhibitory control using a visual search task could improve task-specific measures of attentional control and performance. In Experiment 1 results revealed that training elicited a near-transfer effect, improving performance on a cognitive (antisaccade) task assessing inhibitory control. In Experiment 2 an initial far-transfer effect of training was observed on an index of attentional control validated for tennis. The principal aim of Experiment 3 was to expand on these findings by assessing objective gaze measures of inhibitory control during the performance of a tennis task. Training improved inhibitory control and performance when pressure was elevated, confirming the mechanisms by which cognitive anxiety impacts performance. These results suggest that attentional control training can improve inhibition and reduce taskspecific distractibility with promise of transfer to more efficient sporting performance in competitive contexts.

The Curvilinear Relationship between State Neuroticism and Momentary Task Performance

Science.gov (United States)

Debusscher, Jonas; Hofmans, Joeri; De Fruyt, Filip

2014-01-01

A daily diary and two experience sampling studies were carried out to investigate curvilinearity of the within-person relationship between state neuroticism and task performance, as well as the moderating effects of within-person variation in momentary job demands (i.e., work pressure and task complexity). In one, results showed that under high work pressure, the state neuroticism–task performance relationship was best described by an exponentially decreasing curve, whereas an inverted U-shaped curve was found for tasks low in work pressure, while in another study, a similar trend was visible for task complexity. In the final study, the state neuroticism–momentary task performance relationship was a linear one, and this relationship was moderated by momentary task complexity. Together, results from all three studies showed that it is important to take into account the moderating effects of momentary job demands because within-person variation in job demands affects the way in which state neuroticism relates to momentary levels of task performance. Specifically, we found that experiencing low levels of state neuroticism may be most beneficial in high demanding tasks, whereas more moderate levels of state neuroticism are optimal under low momentary job demands. PMID:25238547

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 ...

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…

7 CFR 4290.760 - How a change in size or activity of a Portfolio Concern affects the RBIC and the Portfolio Concern.

Science.gov (United States)

2010-01-01

... 7 Agriculture 15 2010-01-01 2010-01-01 false How a change in size or activity of a Portfolio Concern affects the RBIC and the Portfolio Concern. 4290.760 Section 4290.760 Agriculture Regulations of... size or activity of a Portfolio Concern affects the RBIC and the Portfolio Concern. (a) Effect on RBIC...

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.

A new active portfolio risk management for an electricity retailer based on a drawdown risk preference

International Nuclear Information System (INIS)

Charwand, Mansour; Gitizadeh, Mohsen; Siano, Pierluigi

2017-01-01

This paper addresses the deciding under uncertainty of an electricity retailer in order to maximise its total expected rate of return. The developed methodology is based on the modelling of the stochastic evolution of zonal prices that seeks to manage a portfolio of different contracts. Retailer's load and the price at each zone are forecasted using the seasonal autoregressive integrated moving average (SARIMA) model and a clustering technique is used for scenario reduction. Supply sources include the pool, self-production facilities, forward and bilateral contracts. The risk of cost fluctuation due to uncertainties is explicitly modelled using the multi-scenario drawdown methodology. This risk function quantifies in aggregated format the frequency and magnitude of the portfolio drawdowns over planning horizon. In-sample and out-of-sample runs are performed for a portfolio allocation problem. Carried out experimental results on the basis of realistic data, show that imposing risk constraints improve the “real” performance of a portfolio management in out-of-sample runs. - Highlights: • A new drawdown-based method is introduced to retailer deciding under uncertainty. • This tool is used to assess the risk levels regarding retailer midterm strategies. • The methodology is based on the modeling of the stochastic evolution of zonal prices. • The risk function quantifies the frequency and magnitude of the portfolio drawdowns. • In-sample and out-of-sample runs are performed for a portfolio allocation problem.

Rules and more rules: the effects of multiple tasks, extensive training, and aging on task-switching performance.

Science.gov (United States)

Buchler, Norbou G; Hoyer, William J; Cerella, John

2008-06-01

Task-switching performance was assessed in young and older adults as a function of the number of task sets to be actively maintained in memory (varied from 1 to 4) over the course of extended training (5 days). Each of the four tasks required the execution of a simple computational algorithm, which was instantaneously cued by the color of the two-digit stimulus. Tasks were presented in pure (task set size 1) and mixed blocks (task set sizes 2, 3, 4), and the task sequence was unpredictable. By considering task switching beyond two tasks, we found evidence for a cognitive control system that is not overwhelmed by task set size load manipulations. Extended training eliminated age effects in task-switching performance, even when the participants had to manage the execution of up to four tasks. The results are discussed in terms of current theories of cognitive control, including task set inertia and production system postulates.

Analysis of the energy portfolio for electricity generation

International Nuclear Information System (INIS)

Ramirez S, J. R.; Alonso V, G.; Esquivel E, J.

2016-09-01

The planning of electricity generation systems considers several factors that must be taken into account in order to design systems that are economical, reliable and sustainable. For this purpose, the Financial Portfolio Theory is applicable to the energy portfolio or the diversification of electricity generation technologies, such as is the combined cycle, wind, thermoelectric and nuclear. This paper presents an application of the Portfolio Theory to the national energy system, based on the total generation costs for each technology, which allows determining the average variance portfolio and the respective share of each of the electricity generation technologies considered, obtaining a portfolio of electricity generation with the maximum possible return for the risk taken in the investments. This paper describes the basic aspects of the Portfolio Theory and its methodology, in which matrices are implemented for the solution of the resulting Lagrange system. (Author)

Selecting Tasks for Evaluating Human Performance as a Function of Gravity

Science.gov (United States)

Norcross, Jason R.; Gernhardt, Michael L.

2011-01-01

A challenge in understanding human performance as a function of gravity is determining which tasks to research. Initial studies began with treadmill walking, which was easy to quantify and control. However, with the development of pressurized rovers, it is less important to optimize human performance for ambulation as pressurized rovers will likely perform gross translation for them. Future crews are likely to spend much of their extravehicular activity (EVA) performing geology, construction,a nd maintenance type tasks. With these types of tasks, people have different performance strategies, and it is often difficult to quantify the task and measure steady-state metabolic rates or perform biomechanical analysis. For many of these types of tasks, subjective feedback may be the only data that can be collected. However, subjective data may not fully support a rigorous scientific comparison of human performance across different gravity levels and suit factors. NASA would benefit from having a wide variety of quantifiable tasks that allow human performance comparison across different conditions. In order to determine which tasks will effectively support scientific studies, many different tasks and data analysis techniques will need to be employed. Many of these tasks and techniques will not be effective, but some will produce quantifiable results that are sensitive enough to show performance differences. One of the primary concerns related to EVA performance is metabolic rate. The higher the metabolic rate, the faster the astronaut will exhaust consumables. The focus of this poster will be on how different tasks affect metabolic rate across different gravity levels.

Portfolio risk-return analysis: The case of the automotive industry in the Czech Republic

Directory of Open Access Journals (Sweden)

Florin Aliu

2017-12-01

Full Text Available Risk has always been the concern of managers and shareholders as a part of decision-making processes. Managers tend to control unsystematic risk mostly while trying to minimize the exposure to systematic (market risk. The paper aims to assess the risk level and risk-return tradeoffs for the companies operating in Czech automotive industry. A diversification formula and calculation of returns using return-on-equity were employed on the yearly basis from 2005 till 2014. The returns and risk calculations were conducted on the portfolio of auto manufacturers, followed by the portfolio of auto suppliers, while the third one was performed for suppliers and manufacturers taken together. The results of the study show that the average correlation coefficient tends to decrease when we move from manufacturers to suppliers, while increasing when we join manufacturers and suppliers in one portfolio. The highest diversification benefit has been reached in the portfolio of auto suppliers. The highest risk is manifested for the portfolio of manufacturers, while the lowest – in the portfolio of auto suppliers. Risk level declined when we joined manufacturers and suppliers in comparison with risk of manufacturers alone. However, the lowest risk and the highest risk-return tradeoff were achieved in the portfolio of suppliers.

Estimating the operator's performance time of emergency procedural tasks based on a task complexity measure

International Nuclear Information System (INIS)

Jung, Won Dae; Park, Jink Yun

2012-01-01

It is important to understand the amount of time required to execute an emergency procedural task in a high-stress situation for managing human performance under emergencies in a nuclear power plant. However, the time to execute an emergency procedural task is highly dependent upon expert judgment due to the lack of actual data. This paper proposes an analytical method to estimate the operator's performance time (OPT) of a procedural task, which is based on a measure of the task complexity (TACOM). The proposed method for estimating an OPT is an equation that uses the TACOM as a variable, and the OPT of a procedural task can be calculated if its relevant TACOM score is available. The validity of the proposed equation is demonstrated by comparing the estimated OPTs with the observed OPTs for emergency procedural tasks in a steam generator tube rupture scenario.

Determinants of alliance portfolio complexity and its effect on innovative performance of companies

NARCIS (Netherlands)

Duijsters, G.M.; Lokshin, B.

2011-01-01

Alliance formation is often described as a mechanism used by firms to increase voluntary knowledge transfers. Access to external knowledge has been increasingly recognized as a main source of a firm's innovativeness. A phenomenon that has recently emerged is alliance portfolio complexity. In line

THE EFFECT OF SCAFFOLDING AND PORTFOLIO ASSESSMENT ON JORDANIAN EFL LEARNERS’ WRITING

Directory of Open Access Journals (Sweden)

Ruba Fahmi Bataineh

2016-07-01

Full Text Available This study examines the potential effect of scaffolding-based instruction and portfolio-based assessment on Jordanian EFL tenth grade students’ overall writing performance and their performance on the sub-skills of focus, development, organization, conventions and word choice. The study uses a quasi-experimental experimental/control group, pre-/posttest design. In the experimental group, 15 female tenth grade students from the North-Eastern Badia Directorate of Education (Jordan were taught to generate ideas, structure, draft, and edit their written pieces using agency scaffolding, the scaffolding principles of contextual support, continuity, intersubjectivity, flow, contingency and handover, and a slightly adapted version of Hamp-Lyons and Condon’s (2000 Portfolio Model of collection, selection and reflection. A control group of 28 students were instructed conventionally per the guidelines of the teacher’s book. Using descriptive statistics and ANCOVA to analyze the students’ scores on the pre- and the posttests, the results showed that the group taught through scaffolding-based instruction and portfolio-based assessment outperformed the control group (at a≤ 0.05 in their overall writing performance and in their performance on the five writing sub-skills.

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.

Age-related decrements in dual-task performance: Comparison of different mobility and cognitive tasks. A cross sectional study.

Science.gov (United States)

Brustio, Paolo Riccardo; Magistro, Daniele; Zecca, Massimiliano; Rabaglietti, Emanuela; Liubicich, Monica Emma

2017-01-01

This cross-sectional study investigated the age-related differences in dual-task performance both in mobility and cognitive tasks and the additive dual-task costs in a sample of older, middle-aged and young adults. 74 older adults (M = 72.63±5.57 years), 58 middle-aged adults (M = 46.69±4.68 years) and 63 young adults (M = 25.34±3.00 years) participated in the study. Participants performed different mobility and subtraction tasks under both single- and dual-task conditions. Linear regressions, repeated-measures and one-way analyses of covariance were used, The results showed: significant effects of the age on the dual and mobility tasks (ptask costs (pperformance under dual-task conditions in all groups (pperformance in the older group (ptask activity affected mobility and cognitive performance, especially in older adults who showed a higher dual-task cost, suggesting that dual-tasks activities are affected by the age and consequently also mobility and cognitive tasks are negatively influenced.

Operational testing of a figure of merit for overall task performance

Science.gov (United States)

Lemay, Moira

1990-01-01

An overall indicator or figure of merit (FOM), for the quality of pilot performance is needed to define optimal workload levels, predict system failure, measure the impact of new automation in the cockpit, and define the relative contributions of subtasks to overall task performance. A normative FOM was developed based on the calculation of a standard score for each component of a complex task. It reflected some effects, detailed in an earlier study, of the introduction of new data link technology into the cockpit. Since the technique showed promise, further testing was done. A new set of data was obtained using the recently developed Multi-Attribute Task Battery. This is a complex battery consisting of four tasks which can be varied in task demand, and on which performance measures can be obtained. This battery was presented to 12 subjects in a 20 minute trial at each of three levels of workload or task demand, and performance measures collected on all four tasks. The NASA-TLX workload rating scale was presented at minutes 6, 12, and 18, of each trial. A figure of merit was then obtained for each run of the battery by calculating a mean, SD, and standard score for each task. Each task contributed its own proportion to the overall FOM, and relative contributions changed with increasing workload. Thus, the FOM shows the effect of task changes, not only on the individual task that is changed, but also on the performance of other tasks and of the whole task. The cost to other tasks of maintaining constant performance on an individual task can be quantified.

Strategic predictors of performance in a divided attention task

Science.gov (United States)

Faragó, Kinga Bettina; Lőrincz, András

2018-01-01

In this study we investigate the strategies of subjects in a complex divided attention task. We conducted a series of experiments with ten participants and evaluated their performance. After an extensive analysis, we identified four strategic measures that justify the achievement of the participants, by highlighting the individual differences and predicting performance in a regression analysis using generalized estimating equations. Selecting the more urgent task and user action between multiple simultaneous possibilities form two of the strategic decisions, respectively. The third one refers to choosing a response within the same task when the opportunity is present. The fourth and most important measure of strategy involves thinking ahead and executing an action before a situation would become critical. This latter one has the effect of reducing later cognitive load or timing constraints and it is shown to explain almost as much variance in performance as the other three, more straightforward predictors together. In addition to determining these strategic predictors, we also show how manipulating task difficulty induces a shift in strategy, thus impairing human performance in the rehearsed task. The results of this study indicate that considerable differences in the divided attention ability of normal subjects can be identified early and with simple measurements. The importance of describing and analyzing strategies is also emphasized, which can substantially influence performance in complex tasks and may serve training needs. PMID:29621292

Strategic predictors of performance in a divided attention task.

Directory of Open Access Journals (Sweden)

Róbert Adrian Rill

Full Text Available In this study we investigate the strategies of subjects in a complex divided attention task. We conducted a series of experiments with ten participants and evaluated their performance. After an extensive analysis, we identified four strategic measures that justify the achievement of the participants, by highlighting the individual differences and predicting performance in a regression analysis using generalized estimating equations. Selecting the more urgent task and user action between multiple simultaneous possibilities form two of the strategic decisions, respectively. The third one refers to choosing a response within the same task when the opportunity is present. The fourth and most important measure of strategy involves thinking ahead and executing an action before a situation would become critical. This latter one has the effect of reducing later cognitive load or timing constraints and it is shown to explain almost as much variance in performance as the other three, more straightforward predictors together. In addition to determining these strategic predictors, we also show how manipulating task difficulty induces a shift in strategy, thus impairing human performance in the rehearsed task. The results of this study indicate that considerable differences in the divided attention ability of normal subjects can be identified early and with simple measurements. The importance of describing and analyzing strategies is also emphasized, which can substantially influence performance in complex tasks and may serve training needs.

Strategic predictors of performance in a divided attention task.

Science.gov (United States)

Rill, Róbert Adrian; Faragó, Kinga Bettina; Lőrincz, András

2018-01-01

In this study we investigate the strategies of subjects in a complex divided attention task. We conducted a series of experiments with ten participants and evaluated their performance. After an extensive analysis, we identified four strategic measures that justify the achievement of the participants, by highlighting the individual differences and predicting performance in a regression analysis using generalized estimating equations. Selecting the more urgent task and user action between multiple simultaneous possibilities form two of the strategic decisions, respectively. The third one refers to choosing a response within the same task when the opportunity is present. The fourth and most important measure of strategy involves thinking ahead and executing an action before a situation would become critical. This latter one has the effect of reducing later cognitive load or timing constraints and it is shown to explain almost as much variance in performance as the other three, more straightforward predictors together. In addition to determining these strategic predictors, we also show how manipulating task difficulty induces a shift in strategy, thus impairing human performance in the rehearsed task. The results of this study indicate that considerable differences in the divided attention ability of normal subjects can be identified early and with simple measurements. The importance of describing and analyzing strategies is also emphasized, which can substantially influence performance in complex tasks and may serve training needs.

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) ...

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…

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

Are factors related to dual-task performance in people with Parkinson's disease dependent on the type of dual task?

Science.gov (United States)

Strouwen, Carolien; Molenaar, Esther A L M; Keus, Samyra H J; Münks, Liesbeth; Heremans, Elke; Vandenberghe, Wim; Bloem, Bastiaan R; Nieuwboer, Alice

2016-02-01

Impaired dual-task performance significantly impacts upon functional mobility in people with Parkinson's disease (PD). The aim of this study was to identify determinants of dual-task performance in people with PD in three different dual tasks to assess their possible task-dependency. We recruited 121 home-dwelling patients with PD (mean age 65.93 years; mean disease duration 8.67 years) whom we subjected to regular walking (control condition) and to three dual-task conditions: walking combined with a backwards Digit Span task, an auditory Stroop task and a Mobile Phone task. We measured dual-task gait velocity using the GAITRite mat and dual-task reaction times and errors on the concurrent tasks as outcomes. Motor, cognitive and descriptive variables which correlated to dual-task performance (p task gait velocity and executive function, tested by the alternating intake test, was significantly associated with gait velocity during the Digit Span (R(2) = 0.65; p task (R(2) = 0.62; p task. Age was a surplus determinant of gait velocity while using a mobile phone. Single-task gait velocity and executive function as measured by a verbal fluency switching task were independent determinants of dual-task gait performance in people with PD. In contrast to expectation, these factors were the same across different tasks, supporting the robustness of the findings. Future study needs to determine whether these factors predict dual-task abnormalities prospectively. Copyright © 2015 Elsevier Ltd. All rights reserved.

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...

Computer-mediated communication: task performance and satisfaction.

Science.gov (United States)

Simon, Andrew F

2006-06-01

The author assessed satisfaction and performance on 3 tasks (idea generation, intellective, judgment) among 75 dyads (N = 150) working through 1 of 3 modes of communication (instant messaging, videoconferencing, face to face). The author based predictions on the Media Naturalness Theory (N. Kock, 2001, 2002) and on findings from past researchers (e.g., D. M. DeRosa, C. Smith, & D. A. Hantula, in press) of the interaction between tasks and media. The present author did not identify task performance differences, although satisfaction with the medium was lower among those dyads communicating through an instant-messaging system than among those interacting face to face or through videoconferencing. The findings support the Media Naturalness Theory. The author discussed them in relation to the participants' frequent use of instant messaging and their familiarity with new communication media.

How do task characteristics affect learning and performance? The roles of variably mapped and dynamic tasks.

Science.gov (United States)

Macnamara, Brooke N; Frank, David J

2018-05-01

For well over a century, scientists have investigated individual differences in performance. The majority of studies have focused on either differences in practice, or differences in cognitive resources. However, the predictive ability of either practice or cognitive resources varies considerably across tasks. We are the first to examine task characteristics' impact on learning and performance in a complex task while controlling for other task characteristics. In 2 experiments we test key theoretical task characteristic thought to moderate the relationship between practice, cognitive resources, and performance. We devised a task where each of several key task characteristics can be manipulated independently. Participants played 5 rounds of a game similar to the popular tower defense videogame Plants vs. Zombies where both cognitive load and game characteristics were manipulated. In Experiment 1, participants either played a consistently mapped version-the stimuli and the associated meaning of their properties were constant across the 5 rounds-or played a variably mapped version-the stimuli and the associated meaning of their properties changed every few minutes. In Experiment 2, participants either played a static version-that is, turn taking with no time pressure-or played a dynamic version-that is, the stimuli moved regardless of participants' response rates. In Experiment 1, participants' accuracy and efficiency were substantially hindered in the variably mapped conditions. In Experiment 2, learning and performance accuracy were hindered in the dynamic conditions, especially when under cognitive load. Our results suggest that task characteristics impact the relative importance of cognitive resources and practice on predicting learning and performance. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Three-dimensional vision enhances task performance independently of the surgical method.

Science.gov (United States)

Wagner, O J; Hagen, M; Kurmann, A; Horgan, S; Candinas, D; Vorburger, S A

2012-10-01

Within the next few years, the medical industry will launch increasingly affordable three-dimensional (3D) vision systems for the operating room (OR). This study aimed to evaluate the effect of two-dimensional (2D) and 3D visualization on surgical skills and task performance. In this study, 34 individuals with varying laparoscopic experience (18 inexperienced individuals) performed three tasks to test spatial relationships, grasping and positioning, dexterity, precision, and hand-eye and hand-hand coordination. Each task was performed in 3D using binocular vision for open performance, the Viking 3Di Vision System for laparoscopic performance, and the DaVinci robotic system. The same tasks were repeated in 2D using an eye patch for monocular vision, conventional laparoscopy, and the DaVinci robotic system. Loss of 3D vision significantly increased the perceived difficulty of a task and the time required to perform it, independently of the approach (P robot than with laparoscopy (P = 0.005). In every case, 3D robotic performance was superior to conventional laparoscopy (2D) (P < 0.001-0.015). The more complex the task, the more 3D vision accelerates task completion compared with 2D vision. The gain in task performance is independent of the surgical method.

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.

Army Energy Initiatives Task Force Industry Summit (portfolio)

Science.gov (United States)

2011-11-03

IY Q N’ZWrt• r Q N’ZWarte US Army Kw•J•I•Io. Atoll. R•public of Monhollltl.nd• fotta..a..,.,., Puerto Rico a (11Jf:!;!6£1) Assistant...Turbine Engines Vehicle connected microgrid to provide assured power Low Speed Electric Vehicles 11 Vehicle Power Energy Initiatives Task Force

Manipulator Performance Evaluation Using Fitts' Taping Task

Energy Technology Data Exchange (ETDEWEB)

Draper, J.V.; Jared, B.C.; Noakes, M.W.

1999-04-25

Metaphorically, a teleoperator with master controllers projects the user's arms and hands into a re- mote area, Therefore, human users interact with teleoperators at a more fundamental level than they do with most human-machine systems. Instead of inputting decisions about how the system should func- tion, teleoperator users input the movements they might make if they were truly in the remote area and the remote machine must recreate their trajectories and impedance. This intense human-machine inter- action requires displays and controls more carefully attuned to human motor capabilities than is neces- sary with most systems. It is important for teleoperated manipulators to be able to recreate human trajectories and impedance in real time. One method for assessing manipulator performance is to observe how well a system be- haves while a human user completes human dexterity tasks with it. Fitts' tapping task has been, used many times in the past for this purpose. This report describes such a performance assessment. The International Submarine Engineering (ISE) Autonomous/Teleoperated Operations Manipulator (ATOM) servomanipulator system was evalu- ated using a generic positioning accuracy task. The task is a simple one but has the merits of (1) pro- ducing a performance function estimate rather than a point estimate and (2) being widely used in the past for human and servomanipulator dexterity tests. Results of testing using this task may, therefore, allow comparison with other manipulators, and is generically representative of a broad class of tasks. Results of the testing indicate that the ATOM manipulator is capable of performing the task. Force reflection had a negative impact on task efficiency in these data. This was most likely caused by the high resistance to movement the master controller exhibited with the force reflection engaged. Measurements of exerted forces were not made, so it is not possible to say whether the force reflection helped

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

Ranking Performance Measures in Multi-Task Agencies

DEFF Research Database (Denmark)

Christensen, Peter Ove; Sabac, Florin; Tian, Joyce

2010-01-01

We derive sufficient conditions for ranking performance evaluation systems in multi-task agency models (using both optimal and linear contracts) in terms of a second-order stochastic dominance (SSD) condition on the likelihood ratios. The SSD condition can be replaced by a variance-covariance mat......We derive sufficient conditions for ranking performance evaluation systems in multi-task agency models (using both optimal and linear contracts) in terms of a second-order stochastic dominance (SSD) condition on the likelihood ratios. The SSD condition can be replaced by a variance...

A Study on Relationships between Functional Performance and Task Performance Measure through Experiments in NPP MCR

International Nuclear Information System (INIS)

Jang, In Seok; Seong, Poong Hyun; Park, Jin Kyun

2011-01-01

Further improvements in levels of organization, management, man-machine interfaces, education, training, etc. are required, if high operating reliability of operators in huge and complex plants such as chemical plants and electrical power generating plants is to be maintained. Improvement requires good understanding of operators' behavior, including defining what is good performance for operators, especially in emergency situations. Human performance measures, therefore, are important to enhance performance and to reduce the probability of incidents and accidents in Nuclear Power Plants (NPPs). Operators' performance measures are used for multi-objectives such as control room design, human system interface evaluation, training, procedure and so on. There are two kinds of representative methods to measure operators' performance. These methods are now known as the functional performance measure and task performance measure. Functional performance measures are basically based on the plant process parameters. Functional performance measures indicate how well the operators controlled selected critical parameters. The parameters selected in this paper are derived from the four Critical Safety Functions (CSFs) identified in the emergency operating procedures such as achievement of subcriticality, maintenance of core cooling, maintenance of heat sink and maintenance of containment integrity. Task performance measures are based on the task analysis. Task analysis is to determine the tasks required and how operators are performed. In this paper, task analysis is done with ideal path for an accident completed by experts and Emergency Operation Procedure (EOP). However, most literatures related to operators' performance have been using one of these measures and there is no research to find out the relationships between two measures. In this paper, the relationships between functional performance measure and task performance measure are investigated using experiments. Shortly

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

Workshift and Antihistamine Effects on Task Performance

National Research Council Canada - National Science Library

Gilliland, Kirby

1997-01-01

Sixteen male subjects, well trained on a battery of cognitive performance assessment tasks, participated in a study to Investigate the effects on human operator performance of work shift (Day Shift vs. Mid shift...

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.

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.

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.

Task complexity and task, goal, and reward interdependence in group performance : a prescriptive model

NARCIS (Netherlands)

Vijfeijken, van H.T.G.A.; Kleingeld, P.A.M.; Tuijl, van H.F.J.M.; Algera, J.A.; Thierry, H.

2002-01-01

A prescriptive model on how to design effective combinations of goal setting and contingent rewards for group performance management is presented. The model incorporates the constructs task complexity, task interdependence, goal interdependence, and reward interdependence and specifies optimal fit

Performance monitoring in obsessive-compulsive undergraduates: Effects of task difficulty.

Science.gov (United States)

Riesel, Anja; Richter, Anika; Kaufmann, Christian; Kathmann, Norbert; Endrass, Tanja

2015-08-01

Both obsessive-compulsive disorder and subclinical obsessive-compulsive (OC) symptoms seem to be associated with hyperactive error-related brain activity. The current study examined performance monitoring in subjects with subclinical OC symptoms using a new task with different levels of difficulty. Nineteen subjects with high and 18 subjects with low OC characteristics performed a random dot cinematogram (RDC) task with three levels of difficulty. The high and low OC groups did not differ in error-related negativity (ERN), correct-related negativity (CRN) and performance irrespective of task difficulty. The amplitude of the ERN decreased with increasing difficulty whereas the magnitude of CRN did not vary. ERN and CRN approached in size and topography with increasing difficulty, which suggests that errors and correct responses are processed more similarly. These results add to a growing number of studies that fail to replicate hyperactive performance monitoring in individuals with OC symptoms in task with higher difficulty or requiring learning. Together with these findings our results suggest that the relationship between OC symptoms and performance monitoring may be sensitive to type of task and task characteristics and cannot be observed in a RDC that differs from typically used tasks in difficulty and the amount of response-conflict. Copyright © 2015 Elsevier Inc. All rights reserved.

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.

Comparative Analysis of Investment Funds Stocks-based Portfolios and BET Stocks-based Portfolios

Directory of Open Access Journals (Sweden)

Ion STANCU

2010-04-01

Full Text Available In this paper we intend to find out what is the best choice of stocks-based portfolio. The major goal is to find whether is more efficient to invest the whole capital in a single sector, like financial investments, or to create a diversified portfolio, taking into account assets from various economic sectors. Capital allocation will be based on the concept of cointegration. We have chosen this method because it can be applied on non-stationary data series, and, besides, it has the advantage of using the whole set of information provided by the financial assets. Another goal is to study how the portfolio structure adjusts if a shock occurs during the period under analysis so that to preserve a certain return or minimize a potential loss. The study will result in an investment solution in the Romanian capital market, even in the context of financial crisis.

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…

The true invariant of an arbitrage free portfolio

Science.gov (United States)

Schmidt, Anatoly B.

2003-03-01

It is shown that the arbitrage free portfolio paradigm being applied to a portfolio with an arbitrary number of shares N allows for the extended solution in which the option price F depends on N. However the resulting stock hedging expense Q= MF (where M is the number of options in the portfolio) does not depend on whether N is treated as an independent variable or as a parameter. Therefore the stock hedging expense is the true invariant of the arbitrage free portfolio paradigm.

Investment portfolio management from cybernetic point of view

Science.gov (United States)

Marchev, Angel, Jr.; Marchev, Angel

2013-12-01

The theory of investment portfolios is a well defined component of financial science. While sound in principle, it faces some setbacks in its real-world implementation. In this paper the authors propose a reformulation of the investment portfolio problem as a cybernetic system where the Investor is the controlling system and the portfolio is the controlled system. Also the portfolio controlling process should be dissected in several ordered phases, so that each phase is represented as a subsystem within the structure of the controlling system Investor.

A Numerical Study for Robust Active Portfolio Management with Worst-Case Downside Risk Measure

Directory of Open Access Journals (Sweden)

Aifan Ling

2014-01-01

Full Text Available Recently, active portfolio management problems are paid close attention by many researchers due to the explosion of fund industries. We consider a numerical study of a robust active portfolio selection model with downside risk and multiple weights constraints in this paper. We compare the numerical performance of solutions with the classical mean-variance tracking error model and the naive 1/N portfolio strategy by real market data from China market and other markets. We find from the numerical results that the tested active models are more attractive and robust than the compared models.

How different types of participant payments alter task performance

Directory of Open Access Journals (Sweden)

Gary L. Brase

2009-08-01

Full Text Available Researchers typically use incentives (such as money or course credit in order to obtain participants who engage in the specific behaviors of interest to the researcher. There is, however, little understanding or agreement on the effects of different types and levels of incentives used. Some results in the domain of statistical reasoning suggest that performance differences --- previously deemed theoretically important --- may actually be due to differences in incentive types across studies. 704 participants completed one of five variants of a statistical reasoning task, for which they received either course credit, flat fee payment, or performance-based payment incentives. Successful task completion was more frequent with performance-based incentives than with either of the other incentive types. Performance on moderately difficult tasks (compared to very easy and very hard tasks was most sensitive to incentives. These results can help resolve existing debates about inconsistent findings, guide more accurate comparisons across studies, and be applied beyond research settings.

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...

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.

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.

On the microeconomic problems studied by portfolio theory

Science.gov (United States)

Nikonov, Oleg; Medvedeva, Marina

2012-09-01

In the paper we consider economically motivated problems, which are treated with the help of methods of portfolio theory that goes back to the papers by H. Markowitz [1] and J. Tobin [2]. We show that the portfolio theory initially developed for risky securities (stocks) could be applied to other objects. In the present paper we consider several situations where such an application is reasonable and seems to be fruitful. Namely, we consider the problems of constructing the efficient portfolio of banking services and the portfolio of counteragents of a firm.

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

The Effect of Cerebellar Transcranial Direct Current Stimulation on A Throwing Task Depends on Individual Level of Task Performance.

Science.gov (United States)

Mizuguchi, Nobuaki; Katayama, Takashi; Kanosue, Kazuyuki

2018-02-10

The effect of cerebellar transcranial direct current stimulation (tDCS) on motor performance remains controversial. Some studies suggest that the effect of tDCS depends upon task-difficulty and individual level of task performance. Here, we investigated whether the effect of cerebellar tDCS on the motor performance depends upon the individual's level of performance. Twenty-four naïve participants practiced dart throwing while receiving a 2-mA cerebellar tDCS for 20 min under three stimulus conditions (anodal-, cathodal-, and sham-tDCS) on separate days with a double-blind, counter-balanced cross-over design. Task performance was assessed by measuring the distance between the center of the bull's eye and the dart's position. Although task performance tended to improve throughout the practice under all stimulus conditions, improvement within a given day was not significant as compared to the first no-stimulus block. In addition, improvement did not differ among stimulation conditions. However, the magnitude of improvement was associated with an individual's level of task performance only under cathodal tDCS condition (p performance improvement only for the sub-group of participants with lower performance levels as compared to that with sham-tDCS (p task performance. Thus, cerebellar tDCS would facilitate learning of a complex motor skill task only in a subset of individuals. Copyright © 2017 IBRO. Published by Elsevier Ltd. All rights reserved.

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.

R functions development for stockPortfolio package

OpenAIRE

Luo, Rui

2013-01-01

Modern portfolio theory is a statistical framework to allocate investment assets properly, with the aim of reducing risk by diversification. In the past decades, a variety of index and group models (with different covariance assumption) have been proposed to optimize the portfolio, including Single Index Model, Constant Correlation Model, Multi-Group Model, and Multi-Index Model. An R package "stockPortfolio" is developed by Drs. Christou and Diez, and fully implemented Single Index Model, Co...

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

Random matrix theory filters and currency portfolio optimisation

Science.gov (United States)

Daly, J.; Crane, M.; Ruskin, H. J.

2010-04-01

Random matrix theory (RMT) filters have recently been shown to improve the optimisation of financial portfolios. This paper studies the effect of three RMT filters on realised portfolio risk, using bootstrap analysis and out-of-sample testing. We considered the case of a foreign exchange and commodity portfolio, weighted towards foreign exchange, and consisting of 39 assets. This was intended to test the limits of RMT filtering, which is more obviously applicable to portfolios with larger numbers of assets. We considered both equally and exponentially weighted covariance matrices, and observed that, despite the small number of assets involved, RMT filters reduced risk in a way that was consistent with a much larger S&P 500 portfolio. The exponential weightings indicated showed good consistency with the value suggested by Riskmetrics, in contrast to previous results involving stocks. This decay factor, along with the low number of past moves preferred in the filtered, equally weighted case, displayed a trend towards models which were reactive to recent market changes. On testing portfolios with fewer assets, RMT filtering provided less or no overall risk reduction. In particular, no long term out-of-sample risk reduction was observed for a portfolio consisting of 15 major currencies and commodities.

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.

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.

Performance in complex motor tasks deteriorates in hyperthermic humans

DEFF Research Database (Denmark)

Piil, Jacob Feder; Lundbye-Jensen, Jesper; Trangmar, Steven J

2017-01-01

-motor tracking performance was reduced by 10.7 ± 6.5% following exercise-induced hyperthermia when integrated in the multipart protocol and 4.4 ± 5.7% when tested separately (bothP 1.3% (P math tasks...... of information or decision-making prior to responding. We hypothesized that divergences could relate to task complexity and developed a protocol consisting of 1) simple motor task [TARGET_pinch], 2) complex motor task [Visuo-motor tracking], 3) simple math task [MATH_type], 4) combined motor-math task [MATH...

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.

Task dynamics in self-organising task groups : expertise, motivational, and performance differences of specialists and generalists

NARCIS (Netherlands)

Zoethout, Kees; Jager, Wander; Molleman, Eric

Multi-agent simulation is applied to explore how different types of task variety cause workgroups to change their task allocation accordingly. We studied two groups, generalists and specialists. We hypothesised that the performance of the specialists would decrease when task variety increases. The

Is a Responsive Default Mode Network Required for Successful Working Memory Task Performance?

Science.gov (United States)

Čeko, Marta; Gracely, John L.; Fitzcharles, Mary-Ann; Seminowicz, David A.; Schweinhardt, Petra

2015-01-01

In studies of cognitive processing using tasks with externally directed attention, regions showing increased (external-task-positive) and decreased or “negative” [default-mode network (DMN)] fMRI responses during task performance are dynamically responsive to increasing task difficulty. Responsiveness (modulation of fMRI signal by increasing load) has been linked directly to successful cognitive task performance in external-task-positive regions but not in DMN regions. To investigate whether a responsive DMN is required for successful cognitive performance, we compared healthy human subjects (n = 23) with individuals shown to have decreased DMN engagement (chronic pain patients, n = 28). Subjects performed a multilevel working-memory task (N-back) during fMRI. If a responsive DMN is required for successful performance, patients having reduced DMN responsiveness should show worsened performance; if performance is not reduced, their brains should show compensatory activation in external-task-positive regions or elsewhere. All subjects showed decreased accuracy and increased reaction times with increasing task level, with no significant group differences on either measure at any level. Patients had significantly reduced negative fMRI response (deactivation) of DMN regions (posterior cingulate/precuneus, medial prefrontal cortex). Controls showed expected modulation of DMN deactivation with increasing task difficulty. Patients showed significantly reduced modulation of DMN deactivation by task difficulty, despite their successful task performance. We found no evidence of compensatory neural recruitment in external-task-positive regions or elsewhere. Individual responsiveness of the external-task-positive ventrolateral prefrontal cortex, but not of DMN regions, correlated with task accuracy. These findings suggest that a responsive DMN may not be required for successful cognitive performance; a responsive external-task-positive network may be sufficient

Matches, Mismatches, and Methods: Multiple-View Workflows for Energy Portfolio Analysis.

Science.gov (United States)

Brehmer, Matthew; Ng, Jocelyn; Tate, Kevin; Munzner, Tamara

2016-01-01

The energy performance of large building portfolios is challenging to analyze and monitor, as current analysis tools are not scalable or they present derived and aggregated data at too coarse of a level. We conducted a visualization design study, beginning with a thorough work domain analysis and a characterization of data and task abstractions. We describe generalizable visual encoding design choices for time-oriented data framed in terms of matches and mismatches, as well as considerations for workflow design. Our designs address several research questions pertaining to scalability, view coordination, and the inappropriateness of line charts for derived and aggregated data due to a combination of data semantics and domain convention. We also present guidelines relating to familiarity and trust, as well as methodological considerations for visualization design studies. Our designs were adopted by our collaborators and incorporated into the design of an energy analysis software application that will be deployed to tens of thousands of energy workers in their client base.

Administrative Task Performance by Heads of Senior High Schools ...

African Journals Online (AJOL)

This study aimed at examining the administrative task performance of heads of senior high schools (SHS) in Ghana from the organising perspective. The study hypothesized that there is no statistically significant difference in the compliance level of organising as an administrative task performance by heads in the rural and ...

Geometrical framework for robust portfolio optimization

OpenAIRE

Bazovkin, Pavel

2014-01-01

We consider a vector-valued multivariate risk measure that depends on the user's profile given by the user's utility. It is constructed on the basis of weighted-mean trimmed regions and represents the solution of an optimization problem. The key feature of this measure is convexity. We apply the measure to the portfolio selection problem, employing different measures of performance as objective functions in a common geometrical framework.

The electricity portfolio simulation model (EPSim) technical description.

Energy Technology Data Exchange (ETDEWEB)

Drennen, Thomas E.; Klotz, Richard (Hobart and William Smith Colleges, Geneva, NY)

2005-09-01

Stakeholders often have competing interests when selecting or planning new power plants. The purpose of developing this preliminary Electricity Portfolio Simulation Model (EPSim) is to provide a first cut, dynamic methodology and approach to this problem, that can subsequently be refined and validated, that may help energy planners, policy makers, and energy students better understand the tradeoffs associated with competing electricity portfolios. EPSim allows the user to explore competing electricity portfolios annually from 2002 to 2025 in terms of five different criteria: cost, environmental impacts, energy dependence, health and safety, and sustainability. Four additional criteria (infrastructure vulnerability, service limitations, policy needs and science and technology needs) may be added in future versions of the model. Using an analytic hierarchy process (AHP) approach, users or groups of users apply weights to each of the criteria. The default energy assumptions of the model mimic Department of Energy's (DOE) electricity portfolio to 2025 (EIA, 2005). At any time, the user can compare alternative portfolios to this reference case portfolio.

How age affects memory task performance in clinically normal hearing persons.

Science.gov (United States)

Vercammen, Charlotte; Goossens, Tine; Wouters, Jan; van Wieringen, Astrid

2017-05-01

The main objective of this study is to investigate memory task performance in different age groups, irrespective of hearing status. Data are collected on a short-term memory task (WAIS-III Digit Span forward) and two working memory tasks (WAIS-III Digit Span backward and the Reading Span Test). The tasks are administered to young (20-30 years, n = 56), middle-aged (50-60 years, n = 47), and older participants (70-80 years, n = 16) with normal hearing thresholds. All participants have passed a cognitive screening task (Montreal Cognitive Assessment (MoCA)). Young participants perform significantly better than middle-aged participants, while middle-aged and older participants perform similarly on the three memory tasks. Our data show that older clinically normal hearing persons perform equally well on the memory tasks as middle-aged persons. However, even under optimal conditions of preserved sensory processing, changes in memory performance occur. Based on our data, these changes set in before middle age.

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)

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

Mean-variance portfolio optimization by using time series approaches based on logarithmic utility function

Science.gov (United States)

Soeryana, E.; Fadhlina, N.; Sukono; Rusyaman, E.; Supian, S.

2017-01-01

Investments in stocks investors are also faced with the issue of risk, due to daily price of stock also fluctuate. For minimize the level of risk, investors usually forming an investment portfolio. Establishment of a portfolio consisting of several stocks are intended to get the optimal composition of the investment portfolio. This paper discussed about optimizing investment portfolio of Mean-Variance to stocks by using mean and volatility is not constant based on logarithmic utility function. Non constant mean analysed using models Autoregressive Moving Average (ARMA), while non constant volatility models are analysed using the Generalized Autoregressive Conditional heteroscedastic (GARCH). Optimization process is performed by using the Lagrangian multiplier technique. As a numerical illustration, the method is used to analyse some Islamic stocks in Indonesia. The expected result is to get the proportion of investment in each Islamic stock analysed.

Credit Portfolio Selection According to Sectors in Risky Environments: Markowitz Practice

OpenAIRE

Halim Kazan; Kültigin Uludag

2014-01-01

In this study, it was researched that how the rate of repayment of loans will be increased and how the credit risk will be minimized in banking sector, by using Markowitz Portfolio Theory. Construction, textile and wholesale and retail sectors were examined under the central bank data. Portfolio groups were selected and risks( variances of Portfolio groups) were evaluated according to Markowitz portfolio theory. Markowitz portfolio theory is effective than the other portfolio selection instru...

Motor-cognitive dual-task performance: effects of a concurrent motor task on distinct components of visual processing capacity.

Science.gov (United States)

Künstler, E C S; Finke, K; Günther, A; Klingner, C; Witte, O; Bublak, P

2018-01-01

Dual tasking, or the simultaneous execution of two continuous tasks, is frequently associated with a performance decline that can be explained within a capacity sharing framework. In this study, we assessed the effects of a concurrent motor task on the efficiency of visual information uptake based on the 'theory of visual attention' (TVA). TVA provides parameter estimates reflecting distinct components of visual processing capacity: perceptual threshold, visual processing speed, and visual short-term memory (VSTM) storage capacity. Moreover, goodness-of-fit values and bootstrapping estimates were derived to test whether the TVA-model is validly applicable also under dual task conditions, and whether the robustness of parameter estimates is comparable in single- and dual-task conditions. 24 subjects of middle to higher age performed a continuous tapping task, and a visual processing task (whole report of briefly presented letter arrays) under both single- and dual-task conditions. Results suggest a decline of both visual processing capacity and VSTM storage capacity under dual-task conditions, while the perceptual threshold remained unaffected by a concurrent motor task. In addition, goodness-of-fit values and bootstrapping estimates support the notion that participants processed the visual task in a qualitatively comparable, although quantitatively less efficient way under dual-task conditions. The results support a capacity sharing account of motor-cognitive dual tasking and suggest that even performing a relatively simple motor task relies on central attentional capacity that is necessary for efficient visual information uptake.

ANALYSING EFFICIENCY OF AGGRESSIVE ETF-COMPOSED PORTFOLIO STRATEGIES

Directory of Open Access Journals (Sweden)

Anton Zaviyalov

2014-01-01

Full Text Available The article investigates investment characteristics of Exchange Traded Funds, a unique category of mutual funds which can be traded like any common equity on any stock exchange through authorized broker companies. One can buy and sell ETFs during the entire trading session, one can open short positions using ETFs and trade on margin. ETF price is determined by supply and demand and due to arbitrage, prices are very close to net asset values (NAV. ETFs attract both individual and institutional investors because they combine the benefits of open-end and closed-end funds. The article explores the results of statistical research to find a principal opportunity to implement an "aggressive" ETF-composed portfolio strategy which can secure stable above-market returns. To put it otherwise, the research aims to test the market efficiency hypothesis in the sector of ETF-composed portfolios. The research methodology centers on statistically testing the null hypothesis whether the average S&P500 return and each of the ETF-composed portfolio strategies average returns are equal to zero. To test such a hypothesis one should perform t-tests with several significance levels. If the null hypothesis is rejected on a certain significance level, this would mean that the average return of the portfolio strategy is significantly different from the average return of the S&P500 index. Based on the results of the t-tests, one can conclude whether the above-mentioned market segment is inefficient or partially inefficient, which would mean one can find an "aggressive"strategy to secure stable above-market returns.

Comparison of precision and speed in laparoscopic and robot-assisted surgical task performance.

Science.gov (United States)

Zihni, Ahmed; Gerull, William D; Cavallo, Jaime A; Ge, Tianjia; Ray, Shuddhadeb; Chiu, Jason; Brunt, L Michael; Awad, Michael M

2018-03-01

Robotic platforms have the potential advantage of providing additional dexterity and precision to surgeons while performing complex laparoscopic tasks, especially for those in training. Few quantitative evaluations of surgical task performance comparing laparoscopic and robotic platforms among surgeons of varying experience levels have been done. We compared measures of quality and efficiency of Fundamentals of Laparoscopic Surgery task performance on these platforms in novices and experienced laparoscopic and robotic surgeons. Fourteen novices, 12 expert laparoscopic surgeons (>100 laparoscopic procedures performed, no robotics experience), and five expert robotic surgeons (>25 robotic procedures performed) performed three Fundamentals of Laparoscopic Surgery tasks on both laparoscopic and robotic platforms: peg transfer (PT), pattern cutting (PC), and intracorporeal suturing. All tasks were repeated three times by each subject on each platform in a randomized order. Mean completion times and mean errors per trial (EPT) were calculated for each task on both platforms. Results were compared using Student's t-test (P task performance was slower on the robotic platform compared with laparoscopy. In comparisons of expert laparoscopists performing tasks on the laparoscopic platform and expert robotic surgeons performing tasks on the robotic platform, expert robotic surgeons demonstrated fewer errors during the PC task (P = 0.009). Robotic assistance provided a reduction in errors at all experience levels for some laparoscopic tasks, but no benefit in the speed of task performance. Robotic assistance may provide some benefit in precision of surgical task performance. Copyright © 2017 Elsevier Inc. All rights reserved.

Power from Perspective: Potential future United States energy portfolios

International Nuclear Information System (INIS)

Tonn, Bruce; Healy, K.C.; Gibson, Amy; Ashish, Ashutosh; Cody, Preston; Beres, Drew; Lulla, Sam; Mazur, Jim; Ritter, A.J.

2009-01-01

This paper presents United States energy portfolios for the year 2030, developed from seven different Perspectives. The Perspectives are characterized by different weights placed on fourteen defining values (e.g., cost, social acceptance). The portfolios were constructed to achieve three primary goals, energy independence, energy security, and greenhouse gas reductions. The portfolios are also evaluated over a comprehensive set of secondary criteria (e.g., economic growth, technical feasibility). It is found that very different portfolios based on very different defining values can achieve the three primary goals. Commonalities among the portfolios include reliance upon cellulosic ethanol, nuclear power, and energy efficiency to meet year 2030 energy demands. It is concluded that the US energy portfolio must be diverse and to achieve national energy goals will require an explicit statement of goals, a strong role for government, and coordinated action across society

Game elements improve performance in a working memory training task

Directory of Open Access Journals (Sweden)

Manuel Ninaus

2015-02-01

Full Text Available The utilization of game elements in a non-game context is currently used in a vast range of different domains. However, research on game elements’ effects in cognitive tasks is still sparse. Thus, in this study we implemented three game elements, namely, progress bar, level indicator, and a thematic setting, in a working memory training task. We evaluated the impact of game elements on user performance and perceived state of flow when compared to a conventional version of the task. Participants interacting with game elements showed higher scores in the working memory training task than participants from a control group who completed the working memory training task without the game elements. Moreover, game elements facilitated the individuals’ performance closer to their maximum working memory capacity. Finally, the perceived flow did not differ between the two groups, which indicates that game elements can induce better performance without changing the perception of being “in the zone”, that is without an increase in anxiety or boredom. This empirical study indicates that certain game elements can improve the performance and efficiency in a working memory task by increasing users’ ability and willingness to train at their optimal performance level. 

Evaluation of a portfolio of electricity generation, using dynamics of systems

International Nuclear Information System (INIS)

Franco Barrera, Juan Felipe; Dyner R, Isaac

2004-01-01

The construction of a Technological Portfolio in charge of a firm of electricity generation in Colombia leads to its study; among other is the case of Empresas Publicas de Medellin (EEPPM.), because this company is nowadays-building new electricity projects in Colombia. EEPPM. will provide electricity using a new technology in Colombia, which is wind power, for the national grid joining hydraulic and thermal generation. A System Dynamics (SD) model was constructed to represent the national power system, specially the EEPPM. Generation facilities, combining both hydraulic and thermal plants along with the new wind farm of EEPPM, the new Technological Portfolio can be represented. SD is useful to learn about the different variables considered in the model, in order to represent interactions, delays and feedbacks that are present in the considered system. The study of the EEPPM portfolio performance allows to understand not only the impact of the high investment in wind power technology, but to study its possible benefits for the portfolio, like Risk and Value at Risk (VaR) reductions. Furthermore, the simulations show the advantage of wind power generation during dry seasons, as ENSO oscillation

Decarbonization of the U.S. electricity sector: Are state energy policy portfolios the solution?

International Nuclear Information System (INIS)

Carley, Sanya

2011-01-01

State governments have taken the lead on U.S. energy and climate policy. It is not yet clear, however, whether state energy policy portfolios can generate results in a similar magnitude or manner to their presumed carbon mitigation potential. This article seeks to address this lack of policy evidence and contribute empirical insights on the carbon mitigation effects of state energy portfolios within the U.S. electricity sector. Using a dynamic, long-term electricity dispatch model with U.S. power plant, utility, and transmission and distribution data between 2010 and 2030, this analysis builds a series of state-level policy portfolio scenarios and performs a comparative scenario analysis. Results reveal that state policy portfolios have modest to minimal carbon mitigation effects in the long run if surrounding states do not adopt similar portfolios as well. The difference in decarbonization potential between isolated state policies and larger, more coordinated policy efforts is due in large part to carbon leakage, which is the export of carbon intensive fossil fuel-based electricity across state lines. Results also confirm that a carbon price of $50/metric ton CO 2 e can generate substantial carbon savings. Although both policy options - an energy policy portfolio or a carbon price - are effective at reducing carbon emissions in the present analysis, neither is as effective alone as when the two strategies are combined. - Research highlights: → Scenario modeling exercise to assess effectiveness of state energy policy portfolios. → Regional coordination has greater decarbonization potential than state policies. → Some states benefit more from regional policy coordination than others. → Emissions leakage attenuates the effect of isolated state policy portfolios. → Carbon price with coordinated energy portfolio has greatest decarbonization potential.

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…

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 ...

Continuous performance task in ADHD: Is reaction time variability a key measure?

Science.gov (United States)

Levy, Florence; Pipingas, Andrew; Harris, Elizabeth V; Farrow, Maree; Silberstein, Richard B

2018-01-01

To compare the use of the Continuous Performance Task (CPT) reaction time variability (intraindividual variability or standard deviation of reaction time), as a measure of vigilance in attention-deficit hyperactivity disorder (ADHD), and stimulant medication response, utilizing a simple CPT X-task vs an A-X-task. Comparative analyses of two separate X-task vs A-X-task data sets, and subgroup analyses of performance on and off medication were conducted. The CPT X-task reaction time variability had a direct relationship to ADHD clinician severity ratings, unlike the CPT A-X-task. Variability in X-task performance was reduced by medication compared with the children's unmedicated performance, but this effect did not reach significance. When the coefficient of variation was applied, severity measures and medication response were significant for the X-task, but not for the A-X-task. The CPT-X-task is a useful clinical screening test for ADHD and medication response. In particular, reaction time variability is related to default mode interference. The A-X-task is less useful in this regard.

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.

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.

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...

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...

Is a Responsive Default Mode Network Required for Successful Working Memory Task Performance?

Science.gov (United States)

Čeko, Marta; Gracely, John L; Fitzcharles, Mary-Ann; Seminowicz, David A; Schweinhardt, Petra; Bushnell, M Catherine

2015-08-19

In studies of cognitive processing using tasks with externally directed attention, regions showing increased (external-task-positive) and decreased or "negative" [default-mode network (DMN)] fMRI responses during task performance are dynamically responsive to increasing task difficulty. Responsiveness (modulation of fMRI signal by increasing load) has been linked directly to successful cognitive task performance in external-task-positive regions but not in DMN regions. To investigate whether a responsive DMN is required for successful cognitive performance, we compared healthy human subjects (n = 23) with individuals shown to have decreased DMN engagement (chronic pain patients, n = 28). Subjects performed a multilevel working-memory task (N-back) during fMRI. If a responsive DMN is required for successful performance, patients having reduced DMN responsiveness should show worsened performance; if performance is not reduced, their brains should show compensatory activation in external-task-positive regions or elsewhere. All subjects showed decreased accuracy and increased reaction times with increasing task level, with no significant group differences on either measure at any level. Patients had significantly reduced negative fMRI response (deactivation) of DMN regions (posterior cingulate/precuneus, medial prefrontal cortex). Controls showed expected modulation of DMN deactivation with increasing task difficulty. Patients showed significantly reduced modulation of DMN deactivation by task difficulty, despite their successful task performance. We found no evidence of compensatory neural recruitment in external-task-positive regions or elsewhere. Individual responsiveness of the external-task-positive ventrolateral prefrontal cortex, but not of DMN regions, correlated with task accuracy. These findings suggest that a responsive DMN may not be required for successful cognitive performance; a responsive external-task-positive network may be sufficient. We studied the

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…

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

Task-irrelevant auditory feedback facilitates motor performance in musicians

Directory of Open Access Journals (Sweden)

Virginia eConde

2012-05-01

Full Text Available An efficient and fast auditory–motor network is a basic resource for trained musicians due to the importance of motor anticipation of sound production in musical performance. When playing an instrument, motor performance always goes along with the production of sounds and the integration between both modalities plays an essential role in the course of musical training. The aim of the present study was to investigate the role of task-irrelevant auditory feedback during motor performance in musicians using a serial reaction time task (SRTT. Our hypothesis was that musicians, due to their extensive auditory–motor practice routine during musical training, have a superior performance and learning capabilities when receiving auditory feedback during SRTT relative to musicians performing the SRTT without any auditory feedback. Here we provide novel evidence that task-irrelevant auditory feedback is capable to reinforce SRTT performance but not learning, a finding that might provide further insight into auditory-motor integration in musicians on a behavioral level.

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

Science.gov (United States)