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The purpose of this paper is to develop a new method for the two‐dimensional direction‐of‐arrival (DOA) estimation of multiple coherently distributed (CD) sources, which can provide lower computational complexity while sustaining the estimation performance within a tolerable level.

Using three parallel uniform linear arrays (ULAs), a new method for parametric estimation of multiple coherently distributed sources is proposed. The proposed method is based on the Taylor approximation to the generalized steering vectors (GSVs) of shifted ULAs, and utilizes the special array geometry. In addition, a simple parameter matching procedure is also given in this paper.

Several numerical experiments have been designed. The experiments are based on coherently distributed source model, and the noise is assumed to be zero‐mean and spatially and temporally white and Gaussian. Numerical results show that the proposed method can exhibit good estimation performance under small angular spread and be applicable to the multisource scenario with different angular distributions.

This research is limited to CD sources. Furthermore, the proposed method is based on the small angular approximation to GSV. Hence, it is fitter for the case of small angular extension.

Without any spectrum‐peak searching, the proposed method provides lower computational cost compared to the classical spectrum‐based methods. Moreover, it does not depend on the prior knowledge about angular distribution shape and is hence robust to mismodeling.

Effusion cooling represents one the most innovative techniques for the thermal management of aero-engine combustors liners. The huge amount of micro-perforations implies a significant computational cost if cooling holes are included in computational fluid dynamics (CFD) simulations; therefore, many efforts are reported in literature to develop lower-order approaches aiming at limiting the number of mesh elements. This paper aims to report a numerical investigation for validating two approaches for modelling film cooling, distinguished according to the way coolant is injected (i.e. through either point or distributed mass sources).

The approaches are validated against experimental data in terms of adiabatic effectiveness and heat transfer coefficient distributions obtained for effusion cooled flat plates. Additional reynolds-averaged naver stokes (RANS) simulations were performed meshing also the perforation, so as to distinguish the contribution of injection modelling with respect to intrinsic limitations of turbulence model modelling.

Despite the simplified strategies for coolant injection, this work clearly shows the feasibility of obtaining a sufficiently accurate reproduction of coolant protection in conjunction with a significant saving in terms of computational cost.

The proposed methodologies allow to take into account the presence of film cooling in simulations of devices characterized by a huge number of holes.

This activity represents the first thorough and quantitative comparison between two approaches for film cooling modelling, highlighting the advantages involved in their application.

The increasing need to access and elaborate dynamic and heterogeneous information sources distributed over the Internet calls for new models and paradigms for application design and development. The mobile agent paradigm promotes the design of applications where agents roam through Internet sites to locally access and elaborate information and resources, possibly co‐operating with each other. Focuses on mobile agent co‐ordination, and presents the TuCSoN co‐ordination model for Internet applications based on mobile information agents. TuCSoN exploits a notion of local tuple‐based interaction space, called a tuple centre. A tuple centre is a tuple space enhanced with the capability of programming its behaviour in response to communication events. This enables properties to be embedded into the interaction space, and a mobile agent to be designed independently of the peculiarities of the information sources. Several issues critical to Internet applications can then be charged on tuple centres transparently to agents. The effectiveness of the TuCSoN model is first shown by means of an application example in the area of Internet information retrieval, then discussed in the context of workflow management and electronic commerce.

Aim of the present monograph is the economic analysis of the role of MNEs regarding globalisation and digital economy and in parallel there is a reference and examination of some legal aspects concerning MNEs, cyberspace and e‐commerce as the means of expression of the digital economy. The whole effort of the author is focused on the examination of various aspects of MNEs and their impact upon globalisation and vice versa and how and if we are moving towards a global digital economy.

Concepts of values-based leadership posit that school principals’ professional practice must be informed by values to ensure coherently purposeful activities. Contingency models stress the contextual dependency of professional practice and the need to match activities to local opportunities and constraints. The purpose of this paper is to reconcile both positions from an integrative perspective and to illustrate examples of “values-based contingency leadership” (Day et al., 2001).

Analyses draw on survey data from 56 German schools in order to relate professional values stated by the principals as well as organizational features of their schools to teacher ratings on leadership behaviour (n=910). Instead of scrutinizing singular variables in isolation, a typological approach serves to identify value profiles as well as organizational configurations. Analyses of variance are applied to examine the combined effects of both factors on leadership behaviour.

Interactional effects in the sample indicate that contextual influences are not homogenous across differing value profiles of principals who operate under equal conditions. Descriptive patterns of leadership behaviour within each organizational configuration reveal how principals accentuate leadership activities according to their value profile.

Due to the low statistical power of the small sample, findings are clearly exploratory in nature. However, replication and extension studies seem fruitful, as effect sizes of value-context interactions are consistent with theoretical assumptions and not artificially inflated by common-source variance.

This paper elaborates and exemplifies the moderating role of values in contextual influences on leadership behaviour. It also provides deeper insights into the content and structure of professional values advocated by school principals.

Starting from a critical analysis of the main criteria currently used to identify marginal areas, this paper aims to propose a new classification model of such territories by leveraging knowledge discovery approaches and knowledge visualization techniques, which represent a fundamental pillar in the knowledge-based urban development process.

The methodology adopted in this study relies on the design science research, which includes five steps: problem identification, objective definition, solution design and development, demonstration and evaluation.

Results demonstrate how to exploit knowledge discovery and visualization to obtain multiple mappings of inner areas, in the aim to identify good practices and optimize resources to set up more effective territorial development strategies and plans. The proposed approach overcomes the traditional way adopted to map inner areas that uses a single indicator (i.e. the distance between a municipality and the nearest pole where it is possible to access to education, health and transportation services) and leverages seven groups of indicators that represent the distinguishing features of territories (territorial capital, social costs, citizenship, geo-demography, economy, innovation and sustainable development).

The proposed model could be enriched by new variables, whose value can be collected by official sources and stakeholders engaged to provide both structured and unstructured data. Also, another enhancement could be the development of a cross-algorithms comparison that may reveal useful to suggest which algorithm can better suit the needs of policy makers or practitioners.

This study sets the ground for proposing a decision support tool that policy makers can use to classify in a new way the inner areas, thus overcoming the current approach and leveraging the distinguishing features of territories.

This study shows how the availability of distributed knowledge sources, the modern knowledge management techniques and the emerging digital technologies can provide new opportunities for the governance of a city or territory, thus revitalizing the domain of knowledge-based urban development.

The purpose of this paper is to explore how companies approach the management of cyber and information risks in their supply chain, what initiatives they adopt to this aim, and to what extent along the supply chain. In fact, the increasing level of connectivity is transforming supply chains, and it creates new opportunities but also new risks in the cyber space. Hence, cyber supply chain risk management (CSCRM) is emerging as a new management construct. The ultimate aim is to help organizations in understanding and improving the CSCRM process and cyber resilience in their supply chains.

This research relied on a qualitative approach based on a comparative case study analysis involving five large multinational companies with headquarters, or branches, in the UK.

Results highlight the importance for CSCRM to shift the viewpoint from the traditional focus on companies’ internal information technology (IT) infrastructure, able to “firewall themselves” only, to the whole supply chain with a cross-functional approach; initiatives for CSCRM are mainly adopted to “respond” and “recover” without a well-rounded approach to supply chain resilience for a long-term capacity to adapt to changes according to an evolutionary approach. Initiatives are adopted at a firm/dyadic level, and a network perspective is missing.

This paper extends the current theory on cyber and information risks in supply chains, as a combination of supply chain risk management and resilience, and information risk management. It provides an analysis and classification of cyber and information risks, sources of risks and initiatives to managing them according to a supply chain perspective, along with an investigation of their adoption across the supply chain. It also studies how the concept of resilience has been deployed in the CSCRM process by companies. By laying the first empirical foundations of the subject, this study stimulates further research on the challenges and drivers of initiatives and coordination mechanisms for CSCRM at a supply chain network level.

Results invite companies to break the “silos” of their activities in CSCRM, embracing the whole supply chain network for better resilience. The adoption of IT security initiatives should be combined with organisational ones and extended beyond the dyad. Where applicable, initiatives should be bi-directional to involve supply chain partners, remove the typical isolation in the CSCRM process and leverage the value of information. Decisions on investments in CSCRM should involve also supply chain managers according to a holistic approach.

A supply chain perspective in the existing scientific contributions is missing in the management of cyber and information risk. This is one of the first empirical studies dealing with this interdisciplinary subject, focusing on risks that are now very high in the companies’ agenda, but still overlooked. It contributes to theory on information risk because it addresses cyber and information risks in massively connected supply chains through a holistic approach that includes technology, people and processes at an extended level that goes beyond the dyad.

The purpose of this paper is to describe UWIRS (Ubiquitous Web Information Retrieval Solution), an agent‐based Web Information Retrieval (WIR) solution designed taking into account the unique features of the World Wide Web (WWW) and the limitations of existing WIR solutions for ubiquitous environments.

UWIRS can offer recommendation services by using the Multi‐Agent Vizier Recommendation Framework (Vizier). Vizier was designed under a generic approach and therefore can provide services to information retrieval applications so these may offer product recommendations that consider several adaptation/personalization dimensions (e.g. user dimension, context, among others).

Overall, the main challenge resides on: location, retrieval, integration and presentation of information from the WWW, quickly and accurately, to satisfy a user's singular information needs.

In UWIRS, agents cooperate in order to retrieve personalized information, considering user needs, goals, preferences and contextual features. UWIRS's agents are responsible for: interpreting user input and adding adaptation information by means of a query enrichment process; identifying and selecting the appropriate data sources taking into consideration the Profile Set (composed of User, Device and Information‐Provider Profiles); executing query routing and the information retrieval process; integrating and filtering the retrieved results; and lastly, coherent presentation of quality and relevant ubiquitous information (anytime, anywhere and anyhow) that satisfies the user's particular information needs and constraints associated to his/her access device.

The aim of this study is to find out the most common types of literature review and the accuracy of citing information related to topic in question among Saudi English as a Foreign Language (EFL) postgraduate students at Al-Baha University. This study also aims at revealing the quality of the literature review written by researchers.

This qualitative study used content analysis to investigate 15 unpublished Master of Arts (MA) dissertations written on EFL of Saudi context. They were analyzed qualitatively using criteria modified from Snyder's (2019) model which is considered a potential method for making theoretical and practical contributions of literature review.

The findings of the study showed that students favored the systematic review over the integrative. Additionally, data showed that students were lacking in paraphrasing and organizing cited information coherently and appropriately. Moreover, students' performance was better in design, conduct, and data abstraction and analysis criterion, whereas they seemed rather weak in structuring and writing the review criteria.

The significance of the study is to provide researchers with methodological guidance and reference to write a comprehensive and appropriate literature review. Based on the findings, this study concluded with some implications that aim to assist researchers in carrying out their studies professionally. Furthermore, the findings provide decision-makers in higher education institutions with important practical implications. In light of the study's findings, it is suggested to carry out further research investigating postgraduate students to find out their perceptions and attitudes regarding the quality standards of scientific research writing and the paraphrasing strategies.

The study analyses the role that open social innovation (OSI) perspective played for Fondazione Banco Alimentare Onlus (FBAO), a food bank in Italy, in responding to the COVID-19 crisis. It answers the following research question: how does a crisis, such as the COVID-19 pandemic, stimulate the adoption of OSI practices to revamp the activities of FBAO and facilitate appropriate solutions to carry out its social mission?

This study employs a qualitative approach. It is based on a single case study.

The study shows how COVID-19 has stimulated the adoption of OSI practices to continue to meet the social mission, creating innovative projects or finding new ways to do the same things.

The study is based on a single case study.

The paper contributes insights into the literature on OSI, examining how inbound and outbound OSI mechanisms can modify business models and increase the adaptation capacity of food banks and their effectiveness. In addition, it provides a rich context in which the social value drivers provided by OSI are studied.

This paper applies the OSI to a food bank to evaluate what this action mode produces for the food bank during a health crisis. Specifically, this is the first paper that studies the COVID-19 crisis response of a food bank from the OSI perspective, focusing on the inbound and outbound OSI processes that characterized the entire network of relationships.