Search results

With suitable optimization criteria, hybrid models have proven to be efficient for preparing portfolios in capital markets of developed countries. This study adapts and investigates these methods for a developing country, thus providing a novel approach to the application of banking and finance. Our specific objectives are to employ a stochastic dominance criterion to evaluate the performances of over-the-counter (OTC) companies in a developing country and to analyze them with a hybrid model involving particle swarm optimization and artificial neural networks.

In order to achieve these aims, the authors conduct a case study of OTC companies in Iran. Weekly and daily returns of 36 companies listed in this market are calculated for one year during 2014–2015. The hybrid model is particularly interesting, and the results of the study identify first-, second- and third-order stochastic dominances among these companies. The study’s chosen model uses the best performing combination of activation functions in our analysis, corresponding to TPT, where T represents hyperbolic tangent transfers and P represents linear transfers.

Our portfolios are based on the shares of companies ranked with respect to the stochastic dominance criterion. Considering the minimum and maximum numbers of shares to be 2 and 10 for each portfolio, an eight-share portfolio is determined to be optimal. Compared with the index of Iran OTC during the research period of this study, our selected portfolio achieves a significantly better performance. Moreover, the methods used in this analysis are shown to be as efficient as they were in the capital markets of developed countries.

The problem of optimizing investment portfolios has to allow for correlations among returns from the financial maintenance period under consideration if an asymmetric distribution of returns exists (Babaei et al., 2015). Therefore, it is desirable to select an appropriate criterion in order to prepare an optimal portfolio and prioritize investment options. Although a back propagation technique is very popular in artificial neural (ANN) training, it is time-consuming to train a network in this way, and other methods such as particle swarm optimization (PSO) should be considered instead. In the hybrid combination of PSO and ANN, it is not the structure of a neural network that changes. Rather, the weighting method and the training technique chosen for the network are the important aspects, and these relate to PSO, so the only role ANN plays in this process is to reduce the errors.

The hybrid model combining ANN and PSO is seen to be considerably successful for generating optimal results and appropriate activation functions. These results are consistent with the theoretical findings of Das et al. (2013) and an application of the simple PSO in a study conducted by Pederson and Chipperfield (2010). Our research results also confirm the efficiency of stochastic dominance criteria as noted in the studies conducted by Roman et al. (2013), ANN as in a study carried out by Kristijanpoller et al. (2014) and PSO as in studies conducted by Liu et al. (2015) and Deng et al. (2012). These studies were carried out in the capital markets of developed countries, whereas the authors’ analysis relates to a developing country.

The authors deduce that the tools and methods whose efficiency was proven in the capital markets of developed countries also apply to, and demonstrate efficiency in, two novel applications of portfolio optimization within developing countries. The first of these is gaining familiarity with the theory and practice of these research tools and the methods that enrich financial knowledge of investors in developing countries. The second of these is the application of tools and methods identified by investors in the capital markets of developing countries, which enables optimal allocation of financial resources and growth of the markets. The authors expect that these findings will contribute to improving the economies of developing countries and thus help with economic development and facilitation of improving trends.

Young people’s involvement should lead to research, and ultimately services, that better reflect young people’s priorities and concerns. Young people with a history of treatment for alcohol and/or drug problems were actively involved in the youth social behaviour and network therapy study. The purpose of this paper is to explore the impact of that involvement on the study and what was learnt about involving young people in drug and alcohol research.

The initial plan was to form a young people’s advisory group (YPAG), but when this proved problematic the study explored alternative approaches in collaboration with researchers and young people. Input from 17 young people informed all key elements of the study.

Involvement of young people needs to be dynamic and flexible, with sensitivity to their personal experiences. Engagement with services was crucial both in recruiting young people and supporting their ongoing engagement. This research identified a need to critically reflect on the extent to which rhetorics of participation and involvement give rise to effective and meaningful involvement for young service users. It also highlights the need for researchers to be more flexible in response to young people’s personal circumstances, particularly when those young people are “less frequently heard”.

This research highlights the need for researchers to be more flexible in response to young people’s personal circumstances, particularly when those young people are “less frequently heard”. It highlights the danger of young people in drug and alcohol research being unintentionally disaffected from involvement through conventional approaches and instead suggests ways in which young people could be involved in influencing if and how they participate in research.

There is an apparent contradiction between dominant discourses and cultures of health services research (including patient and public involvement) that often do not sit easily with ideas of co-production and young people-centred involvement. This paper provides an alternative approach to involvement of young people that can help to enable more meaningful and effective involvement.

The flexible and young people-centred model for involvement which emerged from this work provides a template for a different approach. This may be particularly useful for those who find current practice, such as YPAG, inaccessible.

Successful strategies for maintenance require good decisions and we commonly use stochastic reliability models to help this process. These models involve unknown parameters, so we gather data to learn about these parameters. However, such data are often difficult to collect for maintenance applications, leading to poor parameter estimates and incorrect decisions. A subjective modelling approach can resolve this problem, but requires us to specify suitable prior distributions for the unknown parameters. This paper considers which priors to adopt for common maintenance models and describes the method of predictive elicitation for determining unknown hyperparameters associated with these prior distributions. We discuss the computational difficulties of this approach and consider numerical methods for resolving this problem. Finally, we present practical demonstrations to illustrate the potential benefits of predictive elicitation and subjective analysis. This work provides a major step forward in making the methods of subjective Bayesian inference available to maintenance decision makers in practice. Practical implications. This paper recommends powerful strategies for expressing subjective knowledge about unknown model parameters, in the context of maintenance applications that involve making decisions.

Develops practical models for preventive maintenance policies using Bayesian methods of statistical inference. Considers the analysis of a delayed renewal process and a delayed alternating renewal process with exponential times to failure. This approach has the advantage of generating predictive distributions for numbers of failures and downtimes rather than relying on estimated renewal functions. Demonstrates the superiority of this approach in analysing situations with non‐linear cost functions, which arise in reality, by means of an example.

JUNE, the month of blue skies and roses, is for librarians who teach the end of the teaching year and for younger ones the month of examinations. It is for these and others the real beginning of outdoor library work where it may exist. Unfortunately a few days of beautiful weather early in May were the only adequate evidences of summer warmth to come, and the north‐east winds persist as we write in Southern England. Those who contemplate the open air roof‐top libraries, library gardens with tables and chairs for reading, Story‐hours in the public parks and so many more hopeful activities find this handicap a persistent one. There are, in the average year, very few days that may be given wholly to sedentary outdoor activities and some librarians, we learn, have abandoned official provision for outdoor reading. Private and personal outdoor reading will always continue; there is nothing more delightful. We doubt, however, if nowadays much serious use is made of books outdoors, although we should welcome evidence to the contrary. We are thinking of the general reader. The light romance, the romantic approach to the outdoor world in the modern equivalents of Richard Jefferies and W. H. Hudson seem more to tune with this part of the year. This, like every general Statement, is subject to many exceptions and the good librarian is alert to every reading possibility of the months. This month sees the annual holidays really begin and with plans for their conclusion in the Annual Meeting of the Library Association in late September at Hastings which we hope will be free from the unpleasant features of the Business Meeting at Llandudno.

John Suzuki has joined Chemitrade Ltd. as product manager. He was previously with Honeywell and Stein Ltd.

Despite the need for effective global leaders on the part of business (McKinsey, 2012) and the growing body of empirical research related to the topic of global leadership (Osland, 2013a), very little is known about what global leaders actually do. How do they spend their time? In what kinds of activities are they involved? How do they communicate, coordinate, make decisions, and lead? How is their work similar to or different from that of domestic leaders? In this chapter, we respond to these questions by exploring the nature of global leaders’ work using an approach similar to Mintzberg (1973) in his classic book, The Nature of Managerial Work. We observed five global leaders from five different industries, each for 1 week, and compared our results with Mintzberg’s (1973). In addition, we conducted informal interviews and collected archival data. We content-analyzed the data using the conventions of grounded theory and identified 10 distinguishing characteristics of global leaders’ work. It is characterized by (1) multiple time zones and geographical distance; (2) long hours; (3) flexible schedules and fluid time; (4) dependence on technology; (5) time alone connected to others; (6) extensive travel; (7) functional expertise with global scope; (8) facilitation of information, advice, and action; (9) management of complexity; and (10) confrontation of risk. We conclude by discussing implications for future global leadership research.

Managers with global responsibilities work across distance, across differences in country infrastructure, and across differences in cultural values and expectations. Although the work of global managers is in some respects the same as the work of domestic managers – they must provide leadership, direct action and manage information – in order to be effective, global managers must adapt how they do their work to the global context. Research indicates that success as a global leader depends significantly on the leader’s ability to interact effectively with others who are culturally different. To do this, leaders must be able to adapt their behavior appropriately to the particular circumstances in which they are working. Cultural adaptability is critical to successful global leadership. Research shows that cultural adaptability is related to a number of different experiences, both on and off the job. In this chapter we review the literature on cultural adaptability and leading across cultures; and building on what we know about learning from experience, we suggest developmental experiences which can help leaders develop their cultural adaptability.

This issue is a selected bibliography covering the subject of leadership.