Knowledge-based spatial differences in economic activity,job related migration and housing related migration

This paper analyzes the mutual effects of growth of cities and migration between cities. A model in which cities manufacture goods in a traditional sector and in a technological sector, and each city exhibits independently learning-by-doing in the latter sector is presented. The possibility that the development of one city prevents the development of the other is demonstrated. The higher wage in the developed city attracts the talented residents of the less developed city, to which less talented residents migrate in search of lower housing prices, thus creating bi-directional migration that reinforces the above result. An empirical analysis of the differences between job-related migration and housing-related migration in the U.S. is conducted, finding that these two streams are indeed in-line with the model’s prediction. Implications for regional development policies are discussed.     

The Effects of Oil and Chemical Spillages at Sea

At sea around England and Wales, in an average year there can be 10–12 oil and chemical spillage incidents which require action to be taken, and occasionally a major spill may trigger monitoring studies and local controls on fishing activity. This paper discusses the scope of such incidents and their consequences by reference to two particular incidents; the loss of a container of the pesticide lindane from MV Perintis in the English Channel in 1989, and the grounding of the oil tanker Sea Empress in Wales in 1996 and the consequent oilspill. The latter of these incidents is also compared with the loss of the tanker Braer in Shetland in 1993.     

基于混合方法的南海海域地震动衰减关系研究

我国南海海域面临俯冲带地震的影响,海域俯冲带地震的工程特性是海域工程抗震研究的基础,为给海域工程地震危险性分析提供合理的地震动输入,对于没有实际地震动数据的我国南海海域,文中提出一种基于数值模拟结合其他区域已有经验衰减关系建立本地衰减关系的方法。该方法采用随机有限断层法分别对南海俯冲带和日本东北部俯冲带板内地震动进行模拟,以模拟的不同震级、不同距离下的大量地震动为基础,回归了日本俯冲带与南海俯冲带地震动衰减关系,并推导二者的定量关系,基于此定量关系和已知的日本东北部俯冲带板内地震的经验衰减关系,最终建立南海俯冲带板内地震动的衰减关系。将文中建立的南海地震衰减关系与日本以及汶川地震衰减关系进行对比,结果表明：不同类型的地震的衰减特征存在一定的差异性,海域俯冲带板内地震的衰减速率要快于我国陆地地区的汶川地震的浅地壳地震;数值模拟结合经验关系的混合方法得到的南海俯冲带板内地震动衰减关系具有一定的应用价值,此方法可为没有实际地震动的地区建立衰减关系提供参考,建立的衰减关系可为海洋工程和近海交通重大工程的建设提供依据。     

ON SERVICES OF LANDSCAPES

The Xisha Islands in the South China Sea have long been rich and beautiful in natural resources. However, after the author’s recent visits to the islands, it was observed that the islands have seen a coral damage and a loss of biodiversity. Meanwhile, the marine life and mineral deposits have been plundered for material gains. Preserving the beauty and landscape services of the islands should be the most important to their future, rather than economic benefits. Nurturing love and the Beautiful China dream on these islands will worth more than developing industries such as fishing and marine ranching.     

Bayesian methodology for updating geomechanical parameters and uncertainty quantification

A generic framework for the updating geomechanical parameters is presented. It is based on Bayesian probabilities, and considers several levels of uncertainty. It allows one to properly update the probability distribution function of a given parameter when new data are available. This framework is applied to the case of deformability modulus updating in a large underground structure. Two different approaches were tested in terms of initial knowledge about the parameter, namely no knowledge, and a prior distribution of the parameter based on geological/geotechnical data and application of analytical solutions based on the empirical classification systems. The updating was carried out using the framework together with the results of high quality in situ tests. The Bayesian framework was shown to be a mathematically valid way to deal with the problem of the geomechanical parameter updating and of uncertainty reduction related to the parameter's real value.     

Understanding Community Communications

The architectural design studio is an anomaly in the contemporary research university. Its underlying theories of professional knowledge and teaching are at odds with those of other university-based professional schools. This represents an opportunity: the studio has much to teach other professional schools on the basis of its traditions of education through coaching and learning-by-doing. On the other hand, what is the place of applied science in the studio? This question triggers a more general issue about science education for the professions. I have suggested how teaching what scientists do, rather than their research results, could influence science teaching in the studio. When considered this way, scientific research and architectural design bear a much closer family resemblance to each other.     

Estimation of the carbon footprint of the Galician fishing activity (NW Spain)

The food production system as a whole is recognized as one of the major contributors to environmental impacts. Accordingly, food production, processing, transport and consumption account for a relevant portion of the greenhouse gas (GHG) emissions associated with any country. In this context, there is an increasing market demand for climate-relevant information regarding the global warming impact of consumer food products throughout the supply chains. This article deals with the assessment of the carbon footprint of seafood products as a key subgroup in the food sector. Galicia (NW Spain) was selected as a case study. The analysis is based on a representative set of species within the Galician fishing sector, including species obtained from coastal fishing (e.g. horse mackerel, Atlantic mackerel, European pilchard and blue whiting), offshore fishing (e.g. European hake, megrim and anglerfish), deep-sea fishing (skipjack and yellowfin tuna), extensive aquaculture (mussels) and intensive aquaculture (turbot).The carbon footprints associated with the production-related activities of each selected species were quantified following a business-to-business approach on the basis of 1 year of fishing activity. These individual carbon footprints were used to calculate the carbon footprint for each of the different Galician fisheries and culture activities. Finally, the lump sum of the carbon footprints for coastal, offshore and deep-sea fishing and extensive and intensive aquaculture brought about the carbon footprint of the Galician fishing activity (i.e., capture and culture). A benchmark for quantifying and communicating emission reductions was then provided, and opportunities to reduce the GHG emissions associated with the Galician fishing activity could be prioritized.     

Challenges for integrated design (ID) in sustainable buildings

It is often argued that integrated design (ID) is a powerful way to enhance collaboration in construction projects. This collaboration is seen as a way of improving innovation to create more sustainable buildings. Contrary to the traditional silo-type and linear design process, ID is based on upfront stakeholder involvement and a holistic approach to project decision-making. Although ID’s premises are theoretically-founded, a close empirical look at its practices shows that numerous challenges compromise its results and efficiency. This study examines the ID process through an iterative process that includes the construction of a conceptual framework and its empirical validation. We examine three green construction projects in Canada. Based on the analysis of 26 interviews with key project stakeholders and more than 198 construction documents, the study assembles – and ultimately applies – a multi-lens framework based on four themes: the fragmented nature of construction; risk perception; stakeholders’ commitment; and efficiency in the design process. Results show that three tensions arise in ID practices: between collaboration and process efficiency, between short-term and long-term goals, and between integrated methods and traditional ones. The study sheds light on ID limits and reveals how stakeholders can improve their interactions to design more sustainable buildings.     

A COST-EFFECTIVE SURVEY OF FISH OCCURRING IN A LINEAR WATERBODY

Estimating the abundance of fish which occur at a low density presents difficulties. This study compares intensive netting with extensive electric fishing for the assessment of zander (Stizostedion lucioperca) — a predatory fish which is found in some lakes, rivers and canals. Whilst netting caught more zander per unit area, larger areas could be surveyed using single-pass electric fishing, and the catch per unit effort (man day) was much higher. Electric fishing was examined in detail, and zander which were less than 200 mm in 'forklength' were caught with a low-capture efficiency (<20%), whilst longer fish were caught with a higher and relatively constant efficiency (>40%). The approach is offered as a model to develop methods to assess the abundance of low-density fish.     

Grasping project complexity in large engineering projects: The TOE (Technical, Organizational and Environmental) framework

This paper presents a framework for characterising project complexity in large engineering projects, which can be used to adapt the front-end development phase of engineering projects to the particular complexity. Recently, a large number of project complexity related papers were published, demonstrating the evident importance of “complexity” in current project management research. However, no generally accepted framework is available to support the characterising and understanding of project complexity that appreciates the richness of project complexity in large engineering projects. Therefore the TOE (Technical, Organizational, and Environmental) framework was developed, based on a literature survey building upon existing work and on new empirical work consisting of eighteen interviews about six projects in the process engineering industry. As a result of an inductive approach, this framework presents the elements that contribute to project complexity from a theoretical as well as a practical perspective. The framework can be used to assess the complexity of engineering projects, and subsequently adapt the front-end development phase of projects in order to better manage the complexity of the project.     

A space-time network for telecommuting versus commuting decision-making

In this article, we develop a theoretical framework for the study of telecommuting versus commuting decision-making over a fixed time horizon, such as a work week through the use of a space-time network to conceptualize the decision-makers choices over space and time. The decision-makers are multiclass and multicriteria ones and perceive the criteria of travel cost, travel time, and opportunity cost in an individual fashion. The model is a network equilibrium type and allows for the prediction of the equilibrium flows and, hence, the number of periods that members of each class of decision-makers will telecommute or commute. Qualitative properties of the equilibrium are obtained and an algorithm is given, along with convergence results, and applied to numerical examples.Received: 22 November 2000, Accepted: 17 December 2001, JEL Classification: C61, L86, L91, L96, R41The authors are grateful to the editor and two anonymous referees for their helpful comments and suggestions. This research was supported by NSF Grant No. IIS-0002647. The first authors research was also supported by NSF Grant No. INT-0000309. This support is gratefully acknowledged.     

An empirical analytical framework for agglomeration economies

This paper proposes an empirical analytical framework for agglomeration economies based on a translog production-inverse input demand system. Estimation of the system allows us to identify effects on total factor productivity (TFP), partial factor productivity, factor prices and factor demands. It also provides a decomposition of the aggregate agglomeration elasticity into returns that arise from the increased efficiency of factor inputs and a “direct” agglomeration effect which exists over and above any factor augmentation. This enables us to indirectly address the problem of unobserved heterogeneity in factor “quality”. The paper provides an empirical application of the model using firm level data for UK manufacturing and service industries.     

An input-output analysis of recreational fishing expenditures (2006 & 2011) across the southern United States

This paper examines the economic contribution of recreational fishing expenditures across the southern United States (US). Input-output models were constructed for each southern state using US Fish and Wildlife Service (USFWS) fishing expenditures data, both saltwater and freshwater, to determine the direct, indirect, and induced effects of these expenditures. Comparisons were made between pre- and post-recession (2006 and 2011), freshwater and saltwater fishing, and between states. Expenditures were essentially unchanged from 2006 to 2011; but numbers of participating anglers increased by ten percent and the economic contribution generated by the expenditures increased by 10–30%, depending on the economic indicator. The variations across states were substantial, with Florida dominating the others, especially in saltwater fishing. This study documents the important economic contributions of recreational fishing.     

A Heuristic Approach for Exploring Uncertainties in Transport Planning Research

ABSTRACT

This literature review aims to identify situations of uncertainty from differing perspectives of transport planning research. It elaborates a heuristic framework based on three potential sources of uncertainty: reality, knowledge, and products. The heuristic approach focuses on the way in which uncertainties are first identified as part of the planning context and process, then translated into planning artifacts and concepts, and finally managed in the selection of planning options and effects. We illustrate how this framework can provide a useful tool for theoretical and empirical research in transport planning.     

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.     

Mechanical behavior of lightweight soil reinforced with waste fishing net

Lightweight soil is cement-treated and consists of dredged clayey soil, cement, and air-foam. Reinforced lightweight soil (RLS) contains waste fishing net to increase its shear strength. This paper investigates the strength characteristics and stress–strain behavior of reinforced and unreinforced lightweight soils. Test specimens were prepared with varying admixtures of cement content (8%, 12%, 16%, and 20% by the weight of untreated soil), initial water content (125%, 156%, 187%, 217%, and 250%), air-foam content (1%, 2%, 3%, 4%, and 5%), and waste fishing net (0%, 0.25%, 0.5%, 0.75%, and 1%). Then several series of unconfined compression tests and one-dimensional compression tests were conducted. The experiments with lightweight soil indicated that the unconfined compressive strength increased with an increase in cement content, but decreased with increasing water content and air-foam content. The stress–strain relationship and the unconfined compressive strength were influenced by the percentage of waste fishing net. In addition, the strength of RLS generally increased after adding waste fishing net due to the bond strength and the friction at the interface between waste fishing net and soil mixtures, but the amount of increase in compressive strength was not directly proportional to the percentage of waste fishing net. The results of testing indicated that the maximum increase in compressive strength was obtained for a waste fishing net content of about 0.25%. The bulk unit weight of lightweight soil was strongly dependent on the air-foam content. The compression characteristics of lightweight soil, including the yield stress and compression index, did not depend greatly on whether the samples were cured underwater or in air.     

健康景观及健康社区景观：理论框架与 数字评价系统

快速而广泛的城市化引发了多方面的健康危机。健康的社区景观可以从上游帮助居民维持良好的心理、生理和社会健康状况,从而预防和减少心理及生理疾病的发生。目前,在理论研究的层面,自然景观促进健康的系统性理论框架和相关影响机制还没有完全建立;在方法研究的层面,健康社区景观的系统评价工具还没有形成。本研究旨在初步解决这些问题。通过分析和归纳相关领域的理论和实证文献,发展出一个自然景观促进人类健康的理论框架;该框架包含景观促进心理健康、生理健康和社会健康的10条理论路径。基于此框架,结合中国现有城市社区中常见的景观条件和现有的技术条件,提出一套健康社区景观的数字化评价系统。     

The Effect of Racial and Ethnic Composition on Neighborhood Economic Change: A Multilevel and Longitudinal Look

This article examines the relationship between racial/ethnic composition and neighborhood economic change in a multilevel and longitudinal framework. I employ multilevel modeling to examine how neighborhood minority composition is associated with change in neighborhood relative economic status from 1970 to 2010 in the largest 100 metropolitan areas of the USA. In the multilevel framework, the empirical analysis shows that the shares of black and Hispanic residents are consistently negatively related to neighborhood economic gain even when metropolitan-level factors are taken into account. This study also finds that the negative effect of neighborhood minority composition on neighborhood economic gain is differentiated by deindustrialization and minority composition at the metropolitan level. In the longitudinal framework, the findings show that the negative effect of neighborhood minority composition on neighborhood economic gain has declined over time.     

Effects of intensive fishing on the structure of zooplankton communities and mercury levels

Following the impoundment of hydroelectric reservoirs, a small fraction of the mercury (Hg) in the flooded soils is transformed and released into the ecosystem. This causes an increase in the mercury level in the food chain, particularly in piscivorous fish, and represents a potential risk for human health. In 1998, Hydro-Québec carried out an intensive fishing campaign to examine the feasibility of using intensive fishing as a mitigation tool. The goal of this particular part of the project was to evaluate the impact of intensive fishing on the zooplanktonic communities' structure and mercury levels. Specifically, the effects of intensive fishing on: (1) total biomass and zooplankton size structure (>500, 200-500, 100-200 and 53-100 microm); (2) species composition; and (3) total mercury and methylmercury (MeHg) concentrations in zooplankton of different size fractions were studied. Although important decreases were observed in total zooplankton biomass or its size structure, it cannot be related to the intensive fishing. The results, however, show major changes in the dominance of macrozooplanktonic species in fished lakes as opposed to reference lakes. Similarly, in contrast to the reference lakes, mercury and MeHg concentrations in the four size fractions of the zooplanktonic communities changed from 1998 to 2000 in the fished lakes. The MeHg concentration increased from approximately 20 to 200 ng/gdw from the 53 to 500 microm mesh size fraction, showing a biomagnification in the food chain. The canonical correspondence analysis showed that lakes dominated by Holopedium gibberum presented higher concentrations of Hg and MeHg than lakes dominated by Daphnia spp.     

A simulation approach to recreation planning (A case of changing quality)

Conventional demand based approaches to recreational economics are reviewed and found unsuitable for analyzing the effects of changes of the quality of recreation. An alternative approach using a simulation model is proposed, which allows the use of both quantitative data and subjective input on the qualitative effects. The critical economic variables are found to be fishing recreation visitor days and investment in recreational facilities at the Salton Sea, California. The model results are projected for 20 years and key parameters and assumptions are identified by parametric analysis. These parameters were then subjected to critical interaction by a group of specialists in the area, during a workshop session. Results of the final model are compared to a previous economic study of the region and found to be more pessimistic about the benefits of quality control. Verification of the model is performed by tests of deviation of the predictions of visitor days by the model from the actual visitor days recorded over eight years.