Remarks and corrections to the triangular approximations of fuzzy numbers using ��-weighted valuations

A recent paper was dedicated to find the nearest fuzzy triangular approximations of a fuzzy number by using ??-weighted valuations. We prove, by simple examples, that the results of approximations are not always triangular fuzzy numbers and that in fact they are not fuzzy sets. We give a correct solution of the problem of approximation in a more general case, and we study the properties of identity, additivity, translation invariance, scale invariance, and monotonicity of the new approximation operator.     

Eutrophication of Tamar Lakes (1975–2003): a case study of land-use impacts, potential solutions and fundamental issues for the Water Framework Directive

Tamar Lakes is comprised of two reservoirs, which are located in South West England and in the headwaters of River Tamar at approximately 135 m above ordnance datum. Upper Tamar Lake (UTL) is a direct feed source reservoir of potable water in North Cornwall. Immediately following completion in 1975, UTL was subject to intense blue‐green algal blooms that continue to the present. These blooms create operational problems for water treatment, especially in hot‐dry years. Lower Tamar Lake (LTL) was constructed as a water supply reservoir in 1819 and became obsolete following UTL coming on‐line. Detailed water quality investigations over a period of some 28 years have confirmed the source of nutrient enrichment that fuels the algal blooms to be agriculturally derived, corresponding with a substantial increase in livestock farming. Associated poor land management practices, such as extensive field drainage and inappropriate slurry disposal to land, are linked with substantial elevations in organic contaminants such as ammonia, biochemical oxygen demand (BOD) and suspended solids (SS) during rainfall events. Evidence demonstrates that both reservoirs act as primary treatment lagoons, substantially reducing the worst of these pollutants and providing significant environmental gain. The implications of the Common Agricultural Policy (CAP), the Water Framework Directive (WFD) and regulatory monitoring are discussed in relation to resource management.     

Performance evaluation of misting fans in hot and humid climate

Singapore experiences a hot and humid climate throughout the year. This in turn results in heavy reliance on mechanical systems especially air-conditioning to achieve thermal comfort. An alternative would be the use of evaporative cooling which is less energy intensive. Objective and subjective measurements were conducted at an experimental setup at the National University of Singapore (NUS) to evaluate the thermal conditions and thermal sensations brought about by misting fans. Field measurements were also conducted at food centres in Singapore to determine if they are coherent with the objective and subjective measurements conducted. Analysis of objective and subjective data showed that the misting fan was able to significantly reduce the dry-bulb temperature and thermal sensation votes. This is consistent with field measurements taken, where regression analysis showed that with the misting fan, thermal neutrality can be obtained at a higher outdoor effective temperature (ET*). However, the reduction in temperature comes at the expense of higher relative humidity which results in consistently greater biological (bacterial and fungal) pollutants being enumerated from samples collected under the misting fan system. In some samples, the bacteria count is very much greater than samples collected under the non-misting fan, illustrating the potential for a substantial increase in biological pollutants due to the generation of mists.     

Endocrine disrupting, haematological and biochemical effects of polybrominated diphenyl ethers in a terrestrial songbird, the European starling (Sturnus vulgaris)

We exposed female European starlings (Sturnus vulgaris) during a 6 month period to environmentally relevant concentrations of a pentabromodiphenyl ether (Penta-BDE) mixture (about 1740 μg/kg body weight) through subcutaneous implants, and examined endocrine disruptive, haematological and biochemical effects. To investigate endocrine disrupting effects of PBDEs, testosterone, estradiol and thyroid hormones (T₃ and T₄) were measured in the plasma. We found no significant differences between the control and exposed groups for any of the hormones. However, 14 days after implantation, T₃ concentrations tended to be lower in the exposed group compared to the control group. For albumin, our results suggest that short term exposure of PBDEs may result in a negative effect on albumin, while the opposite was observed on a longer term (6 months after implantation). However, from the statistical analysis, effects on albumin disappeared when excluding females that laid eggs. These results demonstrate that observed effects during the breeding season should be interpreted carefully when the breeding status of females is unknown. There were no significant differences found between the control and exposed groups for the other biochemical parameters (total protein, uric acid, cholesterol, aspartate transaminase, total antioxidative capacity, high-density lipoproteins and creatine kinase) and haematological parameters (amount of red blood cells, haemoglobin concentration, haematocrit, mean corpuscular volume and mean corpuscular haemoglobin). All together, our results suggest that European starlings, similar to other passerine species, may be less sensitive to the effects of organohalogenated pollutants, such as PBDEs, than other bird species.     

Assessing the service quality of building maintenance providers: mechanical and engineering services

This study investigates the service quality in the maintenance of mechanical and engineering services. The determinants of service quality are identified and their means of evaluation are examined. A method of assessment is devised based on the SERVQUAL approach, and its use is then illustrated using a small empirical survey of clients and service providers and the ‘Gap’ model used to quantify the relationships between customer satisfaction, expected service, perceived service and service quality gap.     

The determinants of the vertical boundaries of the construction firm

In the last few years, transaction cost economics has become a popular theory within the construction research community. This approach has been singularly applied as a means to explain and predict phenomena concerning the construction firm, including its vertical boundaries. However, this is at a time when the chief proponents of transaction costs are urging researchers to take a pluralistic stance in relation to the theory of the firm. The aim of this paper is to develop a pluralistic approach to the vertical boundaries of the construction firm. In order to achieve this, an integrative framework is described, based on the development of the efficient boundaries problem and the capabilities approach to vertical integration. Specifically, this framework draws on the complementary strengths of transaction cost economics and the resource‐based view. It is concluded that the potential relative merits of theoretical pluralism, in terms of the vertical boundaries of the construction firm, are sufficient grounds to motivate empirical testing of the predictions associated with the integrative framework of vertical integration presented.     

TRANSLATING TRADITION: Technology,Heidegger's ‘Letting-be,’ and Japanese New Wave Architecture

The Japanese ‘New Wave’ architects are critical of Western rationality, yet resort to sophisticated technology. This seemingly paradoxical stance has correspondences on the one hand with some aspects of Heidegger's thinking on technology and with his notion of ‘letting-be’ (Gelassenheit), and on the other hand with certain traditional Buddhist doctrines.     

Conceptualizing ‘the Urban’ Through the Lens of Durban,South Africa

Contemporary urban theory raises many questions about how ‘the urban’ is being conceptualized in a fast changing world that is approaching an urban epoch. Evolving debates about what it means to be urban, including the similarities and differences between so-called northern and southern cities, the future of cities, the way to manage and sustain cities, and cities’ relationships to the new Urban Agenda and the Sustainable Development Goals, reveal the need for urban theory that can explain and provide insights into contemporary urban governance, processes, and outcomes. This special issue uses Durban as a lens to provide insight into the changing nature of cities in the Global South and Africa in particular, which encapsulate and reflect both formality and informality; tradition and modernity; uneven and unequal growth and social transformation; environmental crises and ‘resilience and sustainability’. This paper reflects on the dominant processes shaping the development of the city, revealing the challenges, tensions, and opportunities that emerge as the city assembles new ways of being urban, through the rationalities, knowledge, experiences, practices and actions of the state, citizens, and the private sector.     

Migration history,migration behavior and selectivity

A series of proportional hazards models are used to study the relationship between migration history and migration behavior for a sample of young adults from the National Longitudinal Survey of Youth. The results support the argument that migration is a selective process. College educated young adults have a greater hazard rate of making an initial migration but a lower hazard rate of re-migration, suggesting they have less need of corrective geographic behavior. Individuals who have moved two or more times are less responsive to national unemployment conditions than first time migrants. Migration is related to the timing of unemployment within a sojourn. The findings suggest that migrant stock is an important determinant of how labor markets function.     

Computational Mixed TEHL Model and Stribeck Curve of a Journal Bearing

The aim of this article is to propose a model capable of estimating the friction along a heavily loaded journal bearing under mixed and hydrodynamic lubrication. The finite element analysis–computational fluid dynamics (FEA-CFD) model takes into consideration the effect of solid deformations, the asperity contact phenomena, and the influence of metal–metal contact in the Reynolds equation. The Stribeck curve for a plain journal bearing under different operational conditions is calculated and compared to experimental results. The major contribution of the article is the novelty of including mixed lubrication, high-load conditions, and thermal effects in a single computational steady-state model. This comprehensive model, not limited to a specific range of operational conditions, can help during design and for health condition monitoring.