Understanding and analyzing the performance of MIMO systems from the microwave perspective

Multiple input multiple output (MIMO) wireless systems use multiple element antennas at the transmitter and receiver to offer improved capacity over conventional single antenna systems in a rich scattering environment. In this paper, the microwave perspective of operation of MIMO system is given. Following the new interpretation of operation, an electromagnetic model is introduced to assess the MIMO system transmission capacity. The proposed model is shown to provide good agreement with reported results in the literature.

Investigations into MIMO systems from an electromagnetic perspective

The paper presents investigations into multiple input multiple output wireless communication systems, which are carried out from an electromagnetic perspective. The first part of the paper focuses on signal propagation models, which can be used for determining the MIMO system capacity or its performance when various space-time coding schemes are applied. Two types of models are considered. In the first model, array antennas are treated in an exact electromagnetic manner but interactions with scattering objects are incorporated using an approximate single bounce scattering approach. The other model is a simple but exact electromagnetic (EM) model, which takes into account EM interactions between antennas and scatterers. In this model, parallel wire dipoles represent antennas as well as scatterers. The second part of the paper reports on investigations into two types of MIMO testbeds. The first one is a simple transmit/receive diversity tested while the other one is a full MIMO testbed. The paper briefly describes the results obtained during the undertaken investigations

Learning orientation and market orientation: From an alliance perspective

The literature on market orientation has grown in significance during the past decade. Whilst there is more literature on market orientation, the literature on learning orientation is also starting to increase. Numerous researchers have studied and found support for the positive relationship between market orientation and learning orientation (eg Slater and Narver 1995). However, not many researchers have investigated the relationship that firms with a high learning orientation have a high market orientation (eg Sinkula, Baker and Noordewier 1997). This paper attempts to investigate that link in more detail. An alliance perspective is taken in understanding this relationship.

Local government modernisation:UK and comparative analysis from an organizational perspective

This article analyses three strands of local government modernization. The first takes an overview of the development of 'modernization' and 'improvement' of local government in the UK under the Labour government since 1997 and the overall programme of reform. We discuss both the shifts and the continuities with the previous decade and a half of the 'new public management' of Conservative administrations. We examine the implicit assumptions about how to achieve organizational and cultural change, arguing that much modernization is premised on a mechanistic metaphor of organizational change. The second section of the article examines other metaphors and theories of organizational change, arguing for the need to consider institutional and organizational perspectives in analysing local government modernization. The third section of the article then applies some organizational concepts to the comparative analysis of local government modernization.

Objects and the production of technological forms of life:understanding organisational arrangements from a postsocial perspective

Objects are produced within, and simultaneously affect, the process of organizing as a consequence of their interaction within social collectives. This paper discusses the impact and influences of the growth of post-social relations, between human and technological objects, on social and organisational arrangements. The paper presents a discussion largely at the conceptual level and draws from a variety of literatures, including the burgeoning sociology of science literature. The discussion in this paper is based on a view that posits the growth of intimate links with epistemic objects within organisations and society. Organising through networks of post-social relations increasingly comes to affect the manner in which differing groups of organisational participants, and particularly various categories of knowledge workers, experience time and spatial arrangements within organisations.

Beyond securitisation : Western Mediterranean international relations from a security perspective 1989-2002

Following the end of the Cold War and the ensuing changes to the international landscape, thinking about security has tended to become more discursive and interpretative in nature. What counts as security has increasingly derived from security discourses (that is, 'securitisation') and uncertainty about the multi-faceted future facing various countries and regions. Within this post-Cold War discourse, the Western Mediterranean has emerged as a region fraught with latent and manifest threats in the economic, political, societal and military sectors. Improved access to EU markets for Maghrebi exports; the security of energy supplies to the EU from Algeria and Libya; lack of democracy and the advance of political Islam; the flow of northward migration and worries about law and order in France, Italy and Spain; the growth in military expenditure and weapons proliferation in the Maghreb; all have been central to the securitisation agenda. However, this agenda has often lacked credibility especially when inter-linkages have purportedly been established between economic underdevelopment and political instability, between the advance of political Islam and the threat to energy supplies, or between immigration and the threat to national identity. Such inter-sectoral linkages distract from the credibility of those 'securitisation instances' which correspond to reality; the former linkages have often been exploited by extremist politicians in south-west European countries as well as by regimes in the Maghreb to advance their respective interests. Thus, securitisation may defeat its main purpose; it may generate responses out of keeping with the aims proclaimed at the outset, aims centred on the countering of real threats and the ensuring of greater stability.

Modelling human performance within manufacturing systems design:from a theoretical towards a practical framework

Computer-based simulation is frequently used to evaluate the capabilities of proposed manufacturing system designs. Unfortunately, the real systems are often found to perform quite differently from simulation predictions and one possible reason for this is an over-simplistic representation of workers' behaviour within current simulation techniques. The accuracy of design predictions could be improved through a modelling tool that integrates with computer-based simulation and incorporates the factors and relationships that determine workers' performance. This paper explores the viability of developing a similar tool based on our previously published theoretical modelling framework. It focuses on evolving this purely theoretical framework towards a practical modelling tool that can actually be used to expand the capabilities of current simulation techniques. Based on an industrial study, the paper investigates how the theoretical framework works in practice, analyses strengths and weaknesses in its formulation, and proposes developments that can contribute towards enabling human performance modelling in a practical way.

The neuroimaging research process from the participants' perspective

The aim of this study was to investigate participants' experiences of taking part in research conducted using fMRI or MEG procedures. Forty-four participants completed a questionnaire after taking part in either fMRI or MEG experiments; the questionnaire asked about experiences of and attitudes toward fMRI/MEG. Ten follow-up interviews were conducted to enable an in-depth analysis of these attitudes and experiences. The findings were generally positive: all participants thought fMRI and MEG were safe procedures, 93% would recommend participating in neuroimaging research to their friends and family, and participants were positive about participating in future neuroimaging research. However, some negative issues were identified. Some participants reported feeling nervous prior to scanning procedures, several participants reported side-effects after taking part, a number of participants were upset at being in a confined space and some participants did not feel confident about exiting the scanner in an emergency. Several recommendations for researchers are made, including a virtual tour of the scanning equipment during the consenting process in order to better prepare potential participants for the scanning experience and to minimize the potential psychological discomfort sometimes experienced in neuroimaging research. © 2006 Elsevier B.V. All rights reserved.

Technology transfer through international manufacturing networks:valuing technology from an owner’s perspective

Technology is a key part of organisational knowledge and gives its owners their distinctive capabilities and competitive advantages. However, to best use these assets technology often needs to be transferred and shared with others through a form of technology collaboration. This raises the important question of how technology should be valued when it is being transferred. Technology valuation has become a critical issue in most transfer transactions. Transfer arrangements and terms of payment have a significant effect on the generation and sharing of joint benefits in commercial, technical and strategic aspects. In this paper the concept of “owner's value” is explored by highlighting its structure and components and assessing the importance of factors affecting value. The influence on technology valuation of the transfer arrangement, the associated terms of payment and the interaction between the shared benefits, cost and risks are discussed.

An investigation into the Hawaiian mantle from a xenolithic perspective

Salt Lake Crater (SLC), on the island of Oahu, Hawaii, is best known for its wide variety of crustal and mantle xenoliths. SLC is only the second locality in oceanic regimes where deeper portions of the upper mantle (i.e., garnet-bearing xenoliths) have been sampled. These garnet-bearing xenoliths, that contain clinopyroxene (cpx), orthopyroxene (opx), olivine, and garnet, are the focus of this study Opx is present in small amounts. Cpx has exsolved opx, spinel, and garnet. In addition, many xenoliths contain spinel-cored garnets. In some xenoliths, opx crystals contain exsolved cpx and spinel. Olivine, cpx, and garnet are in chemical equilibrium with each other. Opx is not in chemical equilibrium with the other dominant minerals. ^ The origin of these xenoliths is interpreted on the basis of liquidus phase relations in the simplified system CaO-MgO-Al2O3-SiO 2 (CMAS) system at 3.0 and 5.0 GPa. The occurrence of spinel-cored garnets and the Ol-Cpx-Gt assemblage suggests that the depth of crystallization of the SLC xenoliths examined was ∼100–110 km (i.e., uppermost asthenosphere). ^ The experimental study is concerned with the equilibrium melting of garnet clinopyroxenite at 2.0–2.5 GPa and it explores the role of such melting process in the generation of tholeiitic and alkalic lavas in ocean island basalts (OIBs). The starting material is a tholeiitic picrite in terms of its normative composition. Its solidus temperature is 1295 ± 15°C and 1332 ± 15°C at 2.0 and 2.5 GPa, respectively. At 2.0 GPa, the liquidus phase is opx that is in reaction relation with the melt. It reacts out at ∼40°C below the liquidus as cpx and spinel appear. Garnet appears long after opx disappearance. Opx is absent in runs at 2.5 GPa. Cpx and garnet appear simultaneously on the liquidus at 2.5 GPa, and are the only assemblage throughout the melting interval. At both the pressures, the partial melts are olivine-hypersthene normative at high melt fraction ( F), becoming moderately to strongly nepheline-normative, as F decreases. It is concluded that the involvement of CO 2 (and perhaps H2O) is necessary for the generation of alkalic melts in most OIBs. ^