Evaluation of dichroic material for enhancing light pipe/natural ventilation and daylighting in an integrated system

Integration of natural ventilation and daylighting in a single installation would make both technologies more attractive. One method for the integration is the use of concentric light pipe and ventilation stack. By constructing the light pipe using dichroic materials, the infrared part of the solar radiation is allowed to be transmitted to the stack but the visible light is guided by the light pipe into a room. The heat gain to the interior can be reduced and the thermal stack effect strengthened. Work presented here involved the experimental and computational evaluation of dichroic materials for enhancing both natural stack ventilation and daylighting. The transmittance of a dichroic light pipe was found to be similar to that of a light pipe with a 95% specular reflectance. The infra-red radiation transmitted through the dichroic material into a passive stack was found to enhance the natural ventilation flow by up to 14%. The effect is greater in summer than in winter, which is highly desirable as there is often a lack of driving force for natural stack ventilation in summer.

Sources of alpha and beta in property funds

This paper examines issues related to potential analytical performance systems for global property funds. These will include traditional attribution methods but will also cover the performance concepts of alpha and beta widely used in other asset classes. We look at issues including...what creates beta, and what drives alpha in real estate investment? How can it be measured and isolated? How do these concepts relate to traditional attribution systems? Can performance records and performance fees adequately distinguish between these drivers? In this paper we illustrate these issues by reference to a case study addressing the complete performance record of a single unlisted fund.

Unlisted property funds and the emerging property markets

This paper sets out to describe the changing nature of global property investment, to provide background information regarding the nature of unlisted property funds and their managers and investors, and especially the role played by unlisted property funds in facilitating cross-border investing. In particular, it focuses on the development of unlisted funds as intermediary structures carrying institutional capital from developed to developing markets. It presents the results of new research by UK research firm Property Funds Research (PFR) and the University of Reading which explores the extent to which this new vehicle has been effective in delivering capital to emerging markets. The research relates the number of funds targetting particular countries and to population and GDP per capita. It finds that there is a very strong relationship between the popularity of a country for investment through this vehicle format and these independent variables. More interesting, perhaps, is the identification of outlier countries where the amount of investment is significantly less - or greater - than that predicted by population and GDP per capita.

Correlation shifts and real estate portfolio management

The success of any diversification strategy depends upon the quality of the estimated correlation between assets. It is well known, however, that there is a tendency for the average correlation among assets to increase when the market falls and vice-versa. Thus, assuming that the correlation between assets is a constant over time seems unrealistic. Nonetheless, these changes in the correlation structure as a consequence of changes in the market’s return suggests that correlation shifts can be modelled as a function of the market return. This is the idea behind the model of Spurgin et al (2000), which models the beta or systematic risk, of the asset as a function of the returns in the market. This is an approach that offers particular attractions to fund managers as it suggest ways by which they can adjust their portfolios to benefit from changes in overall market conditions. In this paper the Spurgin et al (2000) model is applied to 31 real estate market segments in the UK using monthly data over the period 1987:1 to 2000:12. The results show that a number of market segments display significant negative correlation shifts, while others show significantly positive correlation shifts. Using this information fund managers can make strategic and tactical portfolio allocation decisions based on expectations of market volatility alone and so help them achieve greater portfolio performance overall and especially during different phases of the real estate cycle.

Assessing and understanding the impact of stratospheric dynamics and variability on the earth system

Advances in weather and climate research have demonstrated the role of the stratosphere in the Earth system across a wide range of temporal and spatial scales. Stratospheric ozone loss has been identified as a key driver of Southern Hemisphere tropospheric circulation trends, affecting ocean currents and carbon uptake, sea ice, and possibly even the Antarctic ice sheets. Stratospheric variability has also been shown to affect short term and seasonal forecasts, connecting the tropics and midlatitudes and guiding storm track dynamics. The two-way interactions between the stratosphere and the Earth system have motivated the World Climate Research Programme's (WCRP) Stratospheric Processes and Their Role in Climate (SPARC) DynVar activity to investigate the impact of stratospheric dynamics and variability on climate. This assessment will be made possible by two new multi-model datasets. First, roughly 10 models with a well resolved stratosphere are participating in the Coupled Model Intercomparison Project 5 (CMIP5), providing the first multi-model ensemble of climate simulations coupled from the stratopause to the sea floor. Second, the Stratosphere Historical Forecasting Project (SHFP) of WCRP's Climate Variability and predictability (CLIVAR) program is forming a multi-model set of seasonal hindcasts with stratosphere resolving models, revealing the impact of both stratospheric initial conditions and dynamics on intraseasonal prediction. The CMIP5 and SHFP model-data sets will offer an unprecedented opportunity to understand the role of the stratosphere in the natural and forced variability of the Earth system and to determine whether incorporating knowledge of the middle atmosphere improves seasonal forecasts and climate projections. Capsule New modeling efforts will provide unprecedented opportunities to harness our knowledge of the stratosphere to improve weather and climate prediction.

The emergence and use of diagramming in system dynamics: a critical account

The paper reviews the leading diagramming methods employed in system dynamics to communicate the contents of models. The main ideas and historical development of the field are first outlined. Two diagramming methods—causal loop diagrams (CLDs) and stock/flow diagrams (SFDs)—are then described and their advantages and limitations discussed. A set of broad research directions is then outlined. These concern: the abilities of different diagrams to communicate different ideas, the role that diagrams have in group model building, and the question of whether diagrams can be an adequate substitute for simulation modelling. The paper closes by suggesting that although diagrams alone are insufficient, they have many benefits. However, since these benefits have emerged only as ‘craft wisdom’, a more rigorous programme of research into the diagrams' respective attributes is called for.

Occupational futures? Divesting real estate and corporate PFI

Property ownership can tie up large amounts of capital and management energy that business could employ more productively elsewhere. Competitive pressures, accounting changes and increasingly sophisticated occupier requirements are building demand for new and innovative ways to satisfy corporate occupation needs. The investment climate is also changing. Falling interest rates and falling inflation can be expected to undermine returns from the traditional FRI lease. In future, investment returns will be more dependent on active and innovative management geared to the needs of occupiers on whom income depends. Occupier and investor interests, therefore, look set to coincide, but unlocking the potential for both parties will depend on developing new finance and investment vehicles that align their respective needs. In the UK, examples include PFI in the public sector and off-balance sheet financing in the private sector. In the USA, “synthetic lease” structures have also become popular. Growing investment market experience in assessing risks and returns suggests scope for further innovative arrangements in the corporate sector. But how can such arrangements be structured? What are the risks, drivers and barriers?