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111.
An integrative conflict analysis approach, incorporating an Analytic Hierarchy Process (AHP) based preference ranking method into the Graph Model for Conflict Resolution (GMCR), is employed to investigate the Canadian west coast port congestion dispute. The Canadian west coast has historically been an important gateway connecting North America to Asia thanks to its specific geographical and strategic location. Despite successful operations and maintenance of the port facilities to handle international trade during the past few decades, the west coast is now facing increasing congestion problems, resulting in significant delays in transporting goods from the west coast to other parts of Canada and the USA. The strategic analyses carried out in this research suggest potential resolutions in which Canada would expand port facilities at various locations, encouraging traders to continue choosing the Canadian west coast as one of their trade gateways to North America. 相似文献
112.
ARMA models provide a parsimonious and flexible mechanism for modeling the evolution of a time series. Some useful measures of these models (e.g., the autocorrelation function or the spectral density function) are tedious to compute by hand. This paper uses a computer algebra system, not simulation, to calculate measures of interest associated with ARMA models. 相似文献
113.
M. Frost P. Sedlák A. Kruisová M. Landa 《Journal of Materials Engineering and Performance》2014,23(7):2584-2590
Self-expanding stents or stentgrafts made from Nitinol superelastic alloy are widely used for a less invasive treatment of disease-induced localized flow constriction in the cardiovascular system. The therapy is based on insertion of a stent into a blood vessel to maintain the inner diameter of the vessel; it provides highly effective results at minimal cost and with reduced hospital stays. However, since stent is an external mechanical healing tool implemented into human body for quite a long time, information on the mechanical performance of it is of fundamental importance with respect to patient’s safety and comfort. Advantageously, computational structural analysis can provide valuable information on the response of the product in an environment where in vivo experimentation is extremely expensive or impossible. With this motivation, a numerical model of a particular braided self-expanding stent was developed. As a reasonable approximation substantially reducing computational demands, the stent was considered to be composed of a set of helical springs with specific constrains reflecting geometry of the structure. An advanced constitutive model for NiTi-based shape memory alloys including R-phase transition was employed in analysis. Comparison to measurements shows a very good match between the numerical solution and experimental results. Relation between diameter of the stent and uniform radial pressure on its surface is estimated. Information about internal phase and stress state of the material during compression loading provided by the model is used to estimate fatigue properties of the stent during cyclic loading. 相似文献
114.
具有内部同步、2A开关的36V LED驱动器LT3922,是一款紧凑、通用的LED驱动器。 相似文献
115.
Keith Schofield 《Combustion and Flame》2012,159(5):1987-1996
Quantitative deposition studies are reported involving flame gases containing traces of sodium and chlorine. Comparisons with previously published and unpublished data involving Na2SO4 and Na2CO3 deposition indicate a similar behavior and a generic type mechanism. A wide series of propane and hydrogen flames of varying equivalence ratio have been examined that contain sodium on a part per million by volume scale (ppmv) and chlorine either as a similar trace amount or in excess. An important aspect is that deposition is efficient and the product does not directly correlate to the gas-phase metal speciation. Whether sodium is present as gaseous NaCl, NaOH or Na in a flame is irrelevant to the composition of the deposit. Rates are controlled by the total amount of sodium reaching the surface. Once there, the flame becomes solely a provenience of preferred ingredients. Below 850 K, formation rates of NaCl, Na2CO3 or Na2SO4 are the same, and for Na/Cl containing flames the ranking is NaCl > Na2CO3 > NaOH as predicted by thermodynamics. Rates are first-order in alkali and zero-order for chlorine concentrations. They are independent of equivalence ratio, flame temperature, flow velocity, or temperature gradient across the surface boundary layer. Compositional analyses of deposits indicate that below 850 K, where NaCl vaporization is negligible, a several fold excess of chlorine over sodium is required to produce the theoretically predicted 100% deposit of NaCl. The data suggest slight kinetic constraints relating to the chlorine concentrations, which might imply conversions of transient hydroxide or carbonate. Deposition of NaCl continues to higher temperatures but rapidly becomes short-lived due to vaporization. Deposition processes are seen as a steady state balance between a perpetual influx and egress of materials at all temperatures. In this regard, steel corrosion by NaCl is reported above its ‘dew point’ with the formation of Na2CrO4. 相似文献
116.
Aguayo David; Herman Keith; Ojeda Lizette; Flores Lisa Y. 《Canadian Metallurgical Quarterly》2011,4(2):79
In hopes of promoting college success among Mexican Americans, researchers have identified factors related to their academic performance. A gap in the literature exists between the interactive role of acculturation, enculturation, and generation status in predicting college self-efficacy and college performance (grade-point average, or GPA). To fill this void, this study investigated the relation of demographic variables (e.g., age, gender, socioeconomic status) and cultural variables (e.g., acculturation, enculturation, generation status) on academic outcomes (e.g., college self-efficacy, college performance) among 408 Mexican-American college students. Results of a series of hierarchical regression analyses indicated socioeconomic status, generation status, enculturation, and acculturation had significant positive effects on college self-efficacy; socioeconomic status and the interaction of higher enculturation and first-generation status were positively and significantly related to GPA. Post-hoc analyses indicated college self-efficacy predicted college performance for students who were second generation and beyond. Implications for research and practice are discussed. (PsycINFO Database Record (c) 2011 APA, all rights reserved) 相似文献
117.
This paper examines the role of public art in urban redevelopment, focusing on the reconstruction of Coventry (UK) in the post-war years. Overseen by the city's Chief Architect, Donald Gibson, this redevelopment has often been described as resulting in a placeless and artless urban landscape indistinguishable from other redeveloped city centres in post-war Britain. To the contrary, here it is suggested that public art was an important feature of Coventry's new urban landscape, with the attempt to create a new civic identity manifest in a series of highly symbolic and distinctive public artworks. Analysing both the official symbolism of these artworks and their reception in the public sphere, it is concluded that, although just one aspect of the urban landscape, the production and consumption of public art encapsulated the tensions that existed between different visions of the city. 相似文献
118.
Helen Clare Lingard Keith Townsend Lisa Bradley Kerry Brown 《Construction Management & Economics》2013,31(10):1101-1112
Project‐based construction workers in the Australian construction industry work long and irregular hours and experience higher levels of work‐to‐family conflict and burnout than office‐based workers, giving rise to an interest in alternative work schedules as a means of supporting work–life balance. Alternative work schedules were implemented in four case study construction projects in Australia. Interventions differed between projects, with two implementing a compressed work week, and the others introducing reduced hours schedules (one of which was optional). Data were collected from each case study project, using various combinations of focus groups, surveys, interviews and daily diary collection methods. The results were mixed. The compressed work week appears to have been favourably received where it was introduced. However, waged workers still expressed concerns about the impact on their weekly ‘take‐home’ pay. Attempts to reduce work hours by changing from a six‐ to a five‐day schedule (without extending the length of the working day between Monday and Friday) were less favourably received. Waged workers, in particular, did not favour reduced hours schedules. The results confirm the existence of two distinct labour markets operating in the Australian construction industry and markedly different responses to alternative work schedules, based upon whether workers are waged or salaried. The results clearly show that attempts to improve work–life balance must take the structural characteristics of the industry's labour markets into consideration in the design of interventions. The impact of alternative work schedules is likely to be moderated by institutional working time regimes within the construction industry. 相似文献
119.
Paul Bowen Keith Cattell Peter J. Edwards Jonathan Marks 《Construction Management & Economics》2013,31(9):997-1006
The HIV/AIDS pandemic poses a substantial long‐term threat to economic development in South Africa. A questionnaire survey explored the perceptions of a sample of construction firms in the Western Cape regarding HIV/AIDS policy and treatment programmes. The findings show that there is no universal view about the long‐term threat of HIV/AIDS. Most organizations have awareness policies in place but prevention and treatment policies are less common. Treatment programmes are the least implemented of all intervention services due to insufficient resource capacity, the potential stigmatization of infected persons, and low take‐up rates. Despite an acknowledgement of the benefits flowing from mounting treatment programmes, doubt exists as to their financial viability. 相似文献
120.
Susan M. Bogus Keith R. Molenaar James E. Diekmann 《Construction Management & Economics》2013,31(8):829-837
Overlapping activities that are traditionally performed in a sequential manner can significantly reduce project delivery times. Overlapping, however, should be approached in a systematic manner to reduce the costs and risks. Information gathered from sector‐based case studies and from the manufacturing domain suggest a formalised framework for identifying overlapping opportunities and strategies can be successfully implemented for infrastructure projects. This framework considers activity characteristics, such as evolution of upstream information and sensitivity of downstream activities to changes in upstream information, to identify appropriate overlapping strategies. Overlapping strategies, such as early freezing of design criteria, overdesign, and early release of preliminary information, are selected based on activity characteristics. These strategies operate either by speeding up the evolution of upstream information or by reducing the sensitivity of downstream activities. By aligning overlapping strategies with activity characteristics, project managers can make better decisions on when and how much to overlap sequential activities to reduce overall project delivery time. 相似文献