Integration of chaos theory and mathematical models in building simulation: Part II: Conceptual frameworks

Current mathematical models in building research have been limited in most studies to linear dynamics systems. A literature review of past studies investigating chaos theory approaches in building simulation models suggests that as a basis chaos model is valid and can handle the increasing complexity of building systems that have dynamic interactions among all the distributed and hierarchical systems on the one hand, and the environment and occupants on the other. The review also identifies the paucity of literature and the need for a suitable methodology of linking chaos theory to mathematical models in building design and management studies. This study is broadly divided into two parts and presented in two companion papers. Part (I), published in the previous issue, reviews the current state of the chaos theory models as a starting point for establishing theories that can be effectively applied to building simulation models. Part (II) develop conceptual frameworks that approach current model methodologies from the theoretical perspective provided by chaos theory, with a focus on the key concepts and their potential to help to better understand the nonlinear dynamic nature of built environment systems. Case studies are also presented which demonstrate the potential usefulness of chaos theory driven models in a wide variety of leading areas of building research. This study distills the fundamental properties and the most relevant characteristics of chaos theory essential to (1) building simulation scientists and designers (2) initiating a dialogue between scientists and engineers, and (3) stimulating future research on a wide range of issues involved in designing and managing building environmental systems.

Effect of soil waterlogging on below-ground biomass allometric relations in Norway spruce

An increasing importance is assigned to the estimation and verification of carbon stocks in forests. Forestry practice has several long-established and reliable methods for the assessment of aboveground biomass; however we still miss accurate predictors of belowground biomass. A major windthrow event exposing the coarse root systems of Norway spruce trees allowed us to assess the effects of contrasting soil stone and water content on belowground allocation. Increasing stone content decreases root/shoot ratio, while soil waterlogging leads to an increase in this ratio. We constructed allometric relationships for belowground biomass prediction and were able to show that only soil waterlogging significantly impacts model parameters. We showed that diameter at breast height is a reliable predictor of belowground biomass and, once site-specific parameters have been developed, it is possible to accurately estimate belowground biomass in Norway spruce.

Adiposity, insulin and lipid metabolism in post-menopausal women

OBJECTIVE: To investigate relationships between body fat and its distribution and carbohydrate and lipid tolerance using statistical comparisons in post-menopausal women. DESIGN: Sequential meal, postprandial study (600 min) which included a mixed standard breakfast (30 g fat) and lunch (44 g fat) given at 0 and 270 min, respectively, after an overnight fast. SUBJECTS: Twenty-eight post-menopausal women with a diverse range of body weight (body mass index (BMI), mean 27.2, range 20.5-38.8 kg/m2) and abdominal fat deposition (waist, mean 86.4, range 63.5-124.0 cm). Women with BMI <18 or >37 kg/m2, age>80 y and taking hormone replacement therapy (HRT) were excluded. MEASUREMENTS: Anthropometric measurements were performed to assess total and regional fat deposits. The concentrations of plasma total cholesterol, high density lipoprotein (HDL) cholesterol, triacylglycerol (TAG), glucose, insulin (ins), non-esterified fatty acids (NEFA) and apolipoprotein (apo) B-48 were analysed in plasma collected at baseline (fasted state) and at 13 postprandial time points for a 600 min period. RESULTS: Insulin concentrations in the fasted and fed state were significantly correlated with all measures of adiposity (BMI, waist, waist-hip ratio (W/H), waist-height ratio (W/Ht) and sum of skinfold thickness (SSk)). After controlling for BMI, waist remained significantly and positively associated with fasted insulin (r=0.559) with waist contributing 53% to the variability after multiple regression analysis. After controlling for waist, BMI remained significantly correlated with postprandial (IAUC) insulin (r=0.535) contributing 66% of the variability of this measurement. No association was found between any measures of adiposity and glucose concentrations, although insulin concentration in relation to glucose concentration (glucose-insulin ratio) was significantly negatively correlated with all measures of adiposity. A significant positive correlation was found between fasted TAG and BMI (r=0.416), waist (r=0.393) and Ssk (r=0.457) and postprandial (AUC) TAG with BMI (r=0.385) and Ssk (r=0.406). A significantly higher postprandial apolipoprotein (apo) B-48 response was observed in those women with high BMI (>27 kg/m2). Fasting levels of NEFA were significantly and positively correlated with all measures of adiposity (except W/H). No association was found between cholesterol containing particles and any measure of adiposity. CONCLUSION: Hyperinsulinaemia associated with increasing body fat and central fat distribution is associated with normal glucose but not TAG or NEFA concentrations in postmenopausal women.

Use of the LMS adaptive signal processing technique to improve signal data rates from practical oil well logging equipment

The simulation and development work that has been undertaken to produce a signal equaliser used to improve the data rates from oil well logging instruments is presented. The instruments are lowered into the drill bore hole suspended by a cable which has poor electrical characteristics. The equaliser described in the paper corrects for the distortions that occur from the cable (dispersion and attenuation) with the result that the instrument can send data at 100 K.bits/second down its own suspension cable of 12 Km in length. The use of simulation techniques and tools were invaluable in generating a model for the distortions and proved to be a useful tool when site testing was not available.

Multimodel estimate of the global terrestrial water balance: setup and first results

Six land surface models and five global hydrological models participate in a model intercomparison project (WaterMIP), which for the first time compares simulation results of these different classes of models in a consistent way. In this paper the simulation setup is described and aspects of the multi-model global terrestrial water balance are presented. All models were run at 0.5 degree spatial resolution for the global land areas for a 15-year period (1985-1999) using a newly-developed global meteorological dataset. Simulated global terrestrial evapotranspiration, excluding Greenland and Antarctica, ranges from 415 to 586 mm year-1 (60,000 to 85,000 km3 year-1) and simulated runoff ranges from 290 to 457 mm year-1 (42,000 to 66,000 km3 year-1). Both the mean and median runoff fractions for the land surface models are lower than those of the global hydrological models, although the range is wider. Significant simulation differences between land surface and global hydrological models are found to be caused by the snow scheme employed. The physically-based energy balance approach used by land surface models generally results in lower snow water equivalent values than the conceptual degree-day approach used by global hydrological models. Some differences in simulated runoff and evapotranspiration are explained by model parameterizations, although the processes included and parameterizations used are not distinct to either land surface models or global hydrological models. The results show that differences between model are major sources of uncertainty. Climate change impact studies thus need to use not only multiple climate models, but also some other measure of uncertainty, (e.g. multiple impact models).

Using learning networks to understand complex systems: a case study of biological, geophysical and social research in the Amazon

Developing high-quality scientific research will be most effective if research communities with diverse skills and interests are able to share information and knowledge, are aware of the major challenges across disciplines, and can exploit economies of scale to provide robust answers and better inform policy. We evaluate opportunities and challenges facing the development of a more interactive research environment by developing an interdisciplinary synthesis of research on a single geographic region. We focus on the Amazon as it is of enormous regional and global environmental importance and faces a highly uncertain future. To take stock of existing knowledge and provide a framework for analysis we present a set of mini-reviews from fourteen different areas of research, encompassing taxonomy, biodiversity, biogeography, vegetation dynamics, landscape ecology, earth-atmosphere interactions, ecosystem processes, fire, deforestation dynamics, hydrology, hunting, conservation planning, livelihoods, and payments for ecosystem services. Each review highlights the current state of knowledge and identifies research priorities, including major challenges and opportunities. We show that while substantial progress is being made across many areas of scientific research, our understanding of specific issues is often dependent on knowledge from other disciplines. Accelerating the acquisition of reliable and contextualized knowledge about the fate of complex pristine and modified ecosystems is partly dependent on our ability to exploit economies of scale in shared resources and technical expertise, recognise and make explicit interconnections and feedbacks among sub-disciplines, increase the temporal and spatial scale of existing studies, and improve the dissemination of scientific findings to policy makers and society at large. Enhancing interaction among research efforts is vital if we are to make the most of limited funds and overcome the challenges posed by addressing large-scale interdisciplinary questions. Bringing together a diverse scientific community with a single geographic focus can help increase awareness of research questions both within and among disciplines, and reveal the opportunities that may exist for advancing acquisition of reliable knowledge. This approach could be useful for a variety of globally important scientific questions.

Sub-irrigation of Petunia: benefits in dry summers

With the increasing frequency and magnitude of warmer days during the summer in the UK, bedding plants which were a traditional part of the urban green landscape are perceived as unsustainable and water-demanding. During recent summers when bans on irrigation have been imposed, use and sales of bedding plants have dropped dramatically having a negative financial impact on the nursery industry. Retaining bedding species as a feature in public and even private spaces in future may be conditional on them being managed in a manner that minimises their water use. Using Petunia x hybrida ‘Hurrah White’ we aimed to discover which irrigation approach was the most efficient for maintaining plants’ ornamental quality (flower numbers, size and longevity), shoot and root growth under water deficit and periods of complete water withdrawal. Plants were grown from plugs for 51 days in wooden rhizotrons (0.35 m (h) x 0.1 m (w) x 0.065 m (d)); the rhizotrons’ front comprised clear Perspex which enabled us to monitor root growth closely. Irrigation treatments were: 1. watering with the amount which constitutes 50% of container capacity by conventional surface drip-irrigation (‘50% TOP’); 2. 50% as sub-irrigation at 10 cm depth (‘50% SUB’); 3. ‘split’ irrigation: 25% as surface drip- and 25% as sub-irrigation at 15 cm depth (‘25/25 SPLIT’); 4. 25% as conventional surface drip-irrigation (‘25% TOP’). Plants were irrigated daily at 18:00 apart from days 34-36 (inclusive) when water was withdrawn for all the treatments. Plants in ‘50% SUB’ had the most flowers and their size was comparable to that of ‘50% TOP’. Differences between treatments in other ‘quality’ parameters (height, shoot number) were biologically small. There was less root growth at deeper soil surface levels for ‘50% TOP’ which indicated that irrigation methods like ‘50% SUB’ and ‘25/25 SPLIT’ and stronger water deficits encouraged deeper root growth. It is suggested that sub-irrigation at 10 cm depth with water amounts of 50% container capacity would result in the most root growth with the maximum flowering for Petunia. Leaf stomatal conductance appeared to be most sensitive to the changes in substrate moisture content in the deepest part of the soil profile, where most roots were situated.

Organic certification, export market access and the impacts of policy: Bayesian estimation of avocado smallholder “times-to-organic certification” in Michoacán Mexico

This study analyzes organic adoption decisions using a rich set of time-to-organic durations collected from avocado small-holders in Michoacán Mexico. We derive robust, intrasample predictions about the profiles of entry and exit within the conventional-versus-organic complex and we explore the sensitivity of these predictions to choice of functional form. The dynamic nature of the sample allows us to make retrospective predictions and we establish, precisely, the profile of organic entry had the respondents been availed optimal amounts of adoption-restraining resources. A fundamental problem in the dynamic adoption literature, hitherto unrecognized, is discussed and consequent extensions are suggested.

‘Warsaw Pact Military Doctrines in the 70s and 80s: Findings in the East German Archives’

This article draws on Warsaw Treaty Organisation and East German military archives to demonstrate that the WTO's military exercises until the mid-1990s always envisaged an offensive strategy with the aim of reaching the Channel in a few days. Only gradually did this change under Gorbachev and to include also defensive strategies, very much against the opposition of East Germany.

Simulation of hurricane-type vortices in a general circulation model

A study of intense hurricane-type vortices in the ECMWF operational model is reported. These vortices develop around day 4 in the forecast and occur in the tropical belt in areas and at times where intense tropical cyclones normally occur. The frequency resembles that observed over most tropical regions with a pronounced maximum in the western North Pacific. The life time of the vortices and their 3-dimensional structure agree in some fundamental way with observations although, because of the resolution, the systems are less intense than the observed ones. The general large-scale conditions for active and inactive cyclone periods are discussed. The model cyclones are sensitive to the sea-surface temperature and do not develop with sea surface temperatures lower than 28–29°C. The dynamical conditions favouring cyclone development are characterized by intense large-scale divergence in the upper troposphere. Cyclogenesis appears to take place when these conditions are found outside the equatorial zone and over oceans where the water is sufficiently warm.

The international law implications of the Turkish/Kurdish conflict

This article considers the threaties and customs governing armed conflict in the context of the long standing insurgency in southeast Turkey. The first part of the article analyzes the existing treaty and customary law concerning the threshold of an armed conflict and concludes that the insurgency in Southeast Turkey existing since 1984 rises to the level of an armed conflict based on criteria identified both in treaty and customary international law. The next consideration is the classification of this conflict and this part concludes that this situation is a non-international armed conflict due to lack of involvement of forces of another country. Finally, this article considers international humanitarian law applicable to this non-international armed conflict and reveals that as a result of the monumental International Committee of the Red Cross customary humanitarian law study, particularly with respect to the law of targeting, that the rules applicable to international and non-international armed conflict have never been closer.