The evolution and distribution of the Israeli modern retailers

This paper is concerned with the structure and dynamics of modern retail facilities in Israel. It presents the first comprehensive quantitative study of the recent trends in Israeli retail. On the basis of an unique database that includes sizes and locations of retailers for a number of years, we test and challenge some of the traditional theories, as well as the latest approaches to the analysis of urban systems. Recent approaches view cities as self-organizing systems and utilize complexity theory and concepts of order. In the case of Israeli retail application of alternate methods of analysis suggests that the conventional regularities such as rank-size rule, as is implied by the central place theory or the more general power law do not hold. The findings reveal that the sizes of modern retailers display an exponential distribution, consistent across time and scale. This signifies a presence of stable regularity in the structure of retail sizes. Exponential distribution of the retail sizes is shown to reflect a lack of interdependence between the existing and the planned retail facilities. The issue of order versus randomness and self-organization in the size distribution of retailers remains debatable and requires further development of tools and universal criteria for analyzing complex systems.     

Methodological problems of intercultural comparisons of retail environments

The internationalising activities of retailers have tended to precede the theoretical contributions of academics. This is particularly the case for the cultural context within which retail internationalisation takes place. Following an examination of the growth of international retailing activity, the article reviews generic difficulties in studying inter-cultural differences before considering the specific steps which retail practitioners have taken to understand the comparative characteristics of retail and consumer markets through the growth of geodemographic and lifestyle analysis. Finally, we relate one of the most significant integrative intercultural theoretical instruments to the case of retail internationalisation within Western Europe. We find that significant insights into retailer behaviour and strategy can be gained from an understanding of the culturally-specific characteristics of the activity. This revised version was published online in July 2006 with corrections to the Cover Date.     

Leveraging locational insights within retail store development? Assessing the use of location planners’ knowledge in retail marketing

The retail geography literature has long recognised the importance of spatial and catchment analysis to inform decision-making relating to store development. However, less attention has been directed to store development “in practice” and, more specifically, how location research and geographical knowledge is leveraged across the wider retail business – in particular informing the marketing function. Through the use of a semi-structured interview and focus group methodology involving approximately 40 location planning, property and marketing analysts, we find that while some larger retailers have established close links between store development and marketing functions in the exchange of catchment, customer, competitor and loyalty card data to inform local marketing, product ranging, promotional mailings and post-opening store performance reviews, this tends to be the exception rather than the rule. We suggest there is a need for location planners to develop their intra-organisational legitimacy to engender a culture of knowledge-sharing and challenge the departmentalised, silo cultures that exist within some retailers in order to better leverage geographical insights and assist in the realisation of appropriate customer propositions and marketing strategies.     

Well placement optimization with the covariance matrix adaptation evolution strategy and meta-models

The amount of hydrocarbon recovered can be considerably increased by finding optimal placement of non-conventional wells. For that purpose, the use of optimization algorithms, where the objective function is evaluated using a reservoir simulator, is needed. Furthermore, for complex reservoir geologies with high heterogeneities, the optimization problem requires algorithms able to cope with the non-regularity of the objective function. In this paper, we propose an optimization methodology for determining optimal well locations and trajectories based on the covariance matrix adaptation evolution strategy (CMA-ES) which is recognized as one of the most powerful derivative-free optimizers for continuous optimization. In addition, to improve the optimization procedure, two new techniques are proposed: (a) adaptive penalization with rejection in order to handle well placement constraints and (b) incorporation of a meta-model, based on locally weighted regression, into CMA-ES, using an approximate stochastic ranking procedure, in order to reduce the number of reservoir simulations required to evaluate the objective function. The approach is applied to the PUNQ-S3 case and compared with a genetic algorithm (GA) incorporating the Genocop III technique for handling constraints. To allow a fair comparison, both algorithms are used without parameter tuning on the problem, and standard settings are used for the GA and default settings for CMA-ES. It is shown that our new approach outperforms the genetic algorithm: It leads in general to both a higher net present value and a significant reduction in the number of reservoir simulations needed to reach a good well configuration. Moreover, coupling CMA-ES with a meta-model leads to further improvement, which was around 20% for the synthetic case in this study.     

Generalized field-development optimization with well-control zonation

Of concern in the development of oil fields is the problem of determining the optimal locations of wells and the optimal controls to place on the wells. Extraction of hydrocarbon resources from petroleum reservoirs in a cost-effective manner requires that the producers and injectors be placed at optimal locations and that optimal controls be imposed on the wells. While the optimization of well locations and well controls plays an important role in ensuring that the net present value of the project is maximized, optimization of other factors such as well type and number of wells also plays important roles in increasing the profitability of investments. Until very recently, improving the net worth of hydrocarbon assets has been focused primarily on optimizing the well locations or well controls, mostly manually. In recent times, automatic optimization using either gradient-based algorithms or stochastic (global) optimization algorithms has become increasingly popular. A well-control zonation (WCZ) approach to estimating optimal well locations, well rates, well type, and well number is proposed. Our approach uses a set of well coordinates and a set of well-control variables as the optimization parameters. However, one of the well-control variables has its search range extended to cover three parts, one part denoting the region where the well is an injector, a second part denoting the region where there is no well, and a third part denoting the region where the well is a producer. By this, the optimization algorithm is able to match every member in the set of well coordinates to three possibilities within the search space of well controls: an injector, a no-well situation, or a producer. The optimization was performed using differential evolution, and two sample applications were presented to show the effectiveness of the method. Results obtained show that the method is able to reduce the number of optimization variables needed and also to identify simultaneously, optimal well locations, optimal well controls, optimal well type, and the optimum number of wells. Also, comparison of results with the mixed integer nonlinear linear programming (MINLP) approach shows that the WCZ approach mostly outperformed the MINLP approach.     

A simultaneous perturbation stochastic approximation algorithm for coupled well placement and control optimization under geologic uncertainty

Development of subsurface energy and environmental resources can be improved by tuning important decision variables such as well locations and operating rates to optimize a desired performance metric. Optimal well locations in a discretized reservoir model are typically identified by solving an integer programming problem while identification of optimal well settings (controls) is formulated as a continuous optimization problem. In general, however, the decision variables in field development optimization can include many design parameters such as the number, type, location, short-term and long-term operational settings (controls), and drilling schedule of the wells. In addition to the large number of decision variables, field optimization problems are further complicated by the existing technical and physical constraints as well as the uncertainty in describing heterogeneous properties of geologic formations. In this paper, we consider simultaneous optimization of well locations and dynamic rate allocations under geologic uncertainty using a variant of the simultaneous perturbation and stochastic approximation (SPSA). In addition, by taking advantage of the robustness of SPSA against errors in calculating the cost function, we develop an efficient field development optimization under geologic uncertainty, where an ensemble of models are used to describe important flow and transport reservoir properties (e.g., permeability and porosity). We use several numerical experiments, including a channel layer of the SPE10 model and the three-dimensional PUNQ-S3 reservoir, to illustrate the performance improvement that can be achieved by solving a combined well placement and control optimization using the SPSA algorithm under known and uncertain reservoir model assumptions.     

Retailing local food in the Scottish-English borders: A supply chain perspective

Local food is championed as one alternative response to industrial systems of food production and supply. While advocacy for local food is high, there is a lack of empirical evidence about the actual shape and scale of such food supply chains, especially from a retail perspective. Using supply chain diagrams, this paper presents a summary of ‘new’ agro-food geographies for five different retail types—farm shops, butchers, caterers, specialist shops, supermarkets/department stores—that all source local food from suppliers in the Scottish-English borders. Presented as five separate ‘shopping trips’, the paper examines where, how and why retailers source local food. Results reveal the complex nature of local food systems, especially in terms of intra-sector competitive dynamics (with a notable tension between direct forms of retail and established (independent) retailers), links and overlaps with ‘normal’ food retail systems and elastic notions of the ‘local’. The paper also draws a key distinction between locally produced and locally supplied food products.     

Multi-objective optimal layout of distributed storm-water detention

The determination of locations and sizes for such a system is important in a drainage master plan or a storm-water management system. However, the distribution of detentions in the upstream and midstream is often more dispersed using many combinations of volume scales. This paper uses the non-dominated sorting genetic algorithm combined with the Storm Water Management Model to explore and calculate the optimal layout scheme for decentralized rainwater detention. The purpose is to find a design and planning method that can achieve the optimal balance of decentralized detention considering the aspects of flood disaster control, peak flow reduction, and investment cost. The optimal results of Pareto in applied case show that among the five most unfavourable nodes, the detentions with different layout volumes and relatively smaller size can control water logging from rainstorm. The project cost is effectively reduced and the standard of the return period of the regional rainwater system is enhanced from 2 to 20 years.     

Spatial dynamics of retail structure and the venerable retail hierarchy

The retail system is continuously adapting itself to changing demographic conditions, consumer behavior and economic conditions. Existing retail units, getting larger in order to achieve economics of scale, and new forms of large-scale retailing do not fit easily in the traditional spatial pattern of retail concentrations. Neverteless the spatial distribution of retailing in urban areas, as schematized by Berry thirty-five years ago, still has its value. Through an upward hierarchical movement the retail system has adapted itself to an inflexible spatial system, in which downtown has still a dominant position. Future developments, however, may weaken the position of central shopping areas in favour of peripheral locations. This revised version was published online in July 2006 with corrections to the Cover Date.     

海涂垦区骨干除涝排水系统的优化设计

提出联合运用非恒定流技术和优化技术确定海涂垦区骨干除涝系统规模的方法,有利于提高计算精度,降低工程造价.优化模型以投资最小为目标,约束条件包括水量平衡、圣维南方程、过闸流量方程、闸河匹配要求、工程规模限制等.把每一项除涝工程作为一级来考虑,将除涝工程的优化问题转化为多阶段决策问题,用动态规划求解优化模型.在进行非恒定流演算时,设计了特征线法、扩散法、两步法三种差分格式,可以自动淘汰不收敛的差分格式.实例表明,提出的方法是有效而实用的.     

Profit,reputation and ‘doing the right thing’: Convention theory and the problem of food waste in the UK retail sector

In 2014, Tesco – one of the world’s largest food retailers – revealed that it had generated almost 57,000 tonnes of food waste in its UK operations over the previous twelve-month period. This shocking statistic added to existing evidence of a significant environmental and social problem in the UK and across the world. This paper utilises convention theory to examine the role of major retailers in the context of this global problem and assesses their motivations for acting on food waste. Drawing on interviews with key stakeholders (including major retailers), the analysis investigates their main justifications for action on food waste. It finds that retailers mostly appealed to three conventions or ‘orders of worth’ (civic, market and opinion) and used these as a basis for their commitment to food waste reduction. We argue that the combination of these different justifications is feasible and necessary in the context of the retail sector but that they may also lead to some unintended consequences (in the retail sector and beyond). Crucially, we demonstrate how the dilution of civic justifications (by their financial and reputational counterparts) might produce negative outcomes and inaction as retailers attempt to adhere to the so-called ‘food waste hierarchy’. The paper highlights the continuing significance of convention theory as a framework for analysing possible responses to the social and environmental challenges confronting global agro-food systems.     

Spatial modelling of commercial spaces in medium-sized cities

The pattern of commercial spaces in a city has never been the consequence of chance. Retailers have always searched for the ‘best location’, but the notion of what exactly constitutes the ‘best location’ has changed over the decades. It is no longer a question of being close-to-market. It depends on an amount of social, economic and even morphological aspects of urban life, not to mention intrinsic aspects of the retail sector itself, namely new types of stores, products and purchase and payment options. Consequently, the methods retailers have employed to determine ‘best location’ have also evolved, and today increasingly complex mathematical and geospatial models are in use. It should then be safe to assume that commercial geography has changed and therefore, commercial hierarchies need to be re-invented, or at least challenged. A current trend in the literature is revealing more than ever the influence of commerce in the spatial and morphological re-configuration of cities. Thus, the understanding of modern retail patterns may be a key issue in interpreting and regulating the processes of urban, social and economic development. Using as test-beds four Portuguese medium-sized cities, commercial and morphological data was collected, analysed and compared, applying spatial analysis techniques. Similar patterns were found between the four cities, which led to the proposal of two geospatial commercial distribution models, one for the city-centre and one for the suburbia. These models shed a new light on the structure of Portuguese medium-size cities, and may well be valid in other medium and small towns across Europe.     

Exposure to ionising radiations arising from the operation of nuclear installations and cancer mortality

World-wide controversy continues to surround the question of whether exposure to ionising radiations arising from nuclear power plants and radioactive fuel cycle facilities could increase the risk of cancer. The objective was to analyse cancer mortality in towns close to Spanish nuclear power plants and radioactive fuel cycle facilities by reference to their history of exposure to artificial radiation generated by such emissions. An ecological cancer mortality study was conducted to know the effect of artificial radiation, estimated taken into account the magnitude of emissions, in towns ≤30 km of any installation. A model of atmospheric and aquatic dispersion of radionuclides was used. As reference, towns within a 50–100 km radius were matched with exposed by socio-demographic characteristics. For analysis purposes, log-linear Poisson models were fitted. The cumulative effective dose was the measure of exposure. Mortality rates ratios were calculated for each tumour site. Natural radiation and socio-demographic matching variables were included in the models, with ‘installation’ as a random effects term. The estimated cumulative artificial radiation dose was below 350 μSv for all sites. For nuclear power plants overall, analysis showed no positive association with increases in the cumulative dose. In the joint analysis of radioactive fuel cycle facilities, however, mortality was observed to rise with increases in the estimated radiation dose in the case of lung, bone and colorectal cancer, and in breast cancer among women. These results would not appear to be due to exposure arising from the operation of the installations, since were not reproduced around installations of the same type.     

Patterns of gullying in Zimbabwe

In Zimbabwe four contrasting gully locations and associated gully patterns are present, reflecting spatial variations in precipitation, bedrock, soil type and landuse. Deep dendritic gullies, associated with landslip activity and subsurface piping, characterise the wet Eastern Highlands and areas with sodic soils. Shallow discontinuous gully systems characterise bornhardt terrain in the Communal Lands. Dambo gullies tend to form a continuation of the fluvial system. The pattern and temporal variation of gullies was studied in three areas of Communal Land (Mhondoro-Ngesi, Mangewende, Mutema) with particular reference to the influence of average slope and landuse on gully development. In areas of sodic soils the gullies appear to be largely the product of natural processes and their development has only partly been influenced by landuse changes. In contrast the shallow gullies developed on granitic/gneissic terrain tend to occur on cultivated or recently cultivated land. The case studies indicate that a full assessment of gully development can only be achieved if a temporal perspective is also considered.     

Well placement optimization subject to realistic field development constraints

This work considers the well placement problem in reservoir management and field development optimization. In particular, it emphasizes embedding realistic and practical constraints into a mathematical optimization formulation. Such constraints are a prerequisite for the wider use of mathematical optimization techniques in well placement problems, since constraints are a way to incorporate reservoir engineering knowledge into the problem formulation. There are important design limitations that are used by the field development team when treating the well placement problem, and these limitations need to be articulated and eventually formalized within the problem before conducting the search for optimal well placements. In addition, these design limitations may be explicit or implicit. In this work, various design limitations pertaining to well locations have been developed in close collaboration with a field operator on the Norwegian Continental Shelf. Moreover, this work focuses on developing constraint-handling capability to enforce these various considerations during optimization. In particular, the Particle Swarm Optimization (PSO) algorithm is applied to optimize for the well locations, and various practical well placement constraints are incorporated into the PSO algorithm using two different constraint-handling techniques: a decoder procedure and the penalty method. The decoder procedure maps the feasible search space onto a cube and has the advantage of not requiring parameter tuning. The penalty method converts the constrained optimization problem into an unconstrained one by introducing an additional term, which is called a penalty function, to the objective function. In contrast to the penalty method, only feasible solutions are evaluated in the decoder method. Through numerical simulations, a comparison between the penalty method and the decoder technique is performed for two cases. We show that the decoder technique can easily be implemented for the well placement problem, and furthermore, that it performs better than the penalty method in most of the cases.     

利用温度全局优化法探测堤坝多重集中渗漏

利用地温探测堤坝工程中的多重集中渗漏通道位置是一种反问题,为取得全局最优解及突破现有方法的局限性,采用不同优化算法相互配合的温度全局最优化方法,以达到有效准确探测显著集中渗漏通道的位置。结合各算法优势及目标函数不连续性等特点,选用全局搜索(GS)、多初始点(MS)及遗传算法(GA)3种方法联合补充优化。首先利用GS搜索局部最优点; 然后结合目标函数不连续点及上述局部最优点,人工增加MS优化起始点进行多初始点优化; 最后依据上述局部解,利用GA混合算法优化,从而有效提高全局最优化的概率。根据堤坝工程集中渗漏通道低温补给的特点,对优化目标函数进行了具有特定物理意义的修正; 为减少每次迭代的优化参数,基于温度测试精度提出分步优化方法,根据温度或修正目标函数残差吸引盆特征确定某步优化的集中渗漏数量; 由修正残差与温度测量精度相对大小确定优化是否终止,对应修正残差最小的优化结果为集中渗漏通道位置的真实解。结合工程实例,计算了某水库左坝肩的多重集中渗漏通道位置,分步优化了两个主要的集中渗漏位置,直接法优化3个集中渗漏位置。文献及工程实践证明了该法的正确性及有效性,为了堤坝等水利工程岩土体的集中渗漏整治提供了科学依据。     

Optimum versus reality in Israel's town system

Israel's town system consists of 37 towns of different size, 28 development towns, and 24 semi-urban Jewish and Arab settlements, most of them consisting of 5,000–10,000 inhabitants. In the existing town system there is an exaggerated concentration of large towns in the Tel Aviv region; an excessive number of development towns; slow urban growth in the Negev and the Galilee; failure of semi-urban settlements to attain urban status; and the absence of urban settlements in many regions where they would be needed.A proposal to outline an optimal system of Israel's town development is discussed. It was found that the existing urban system in Israel shows a distortion which is four times bigger than the optimal one. A comparison between the optimal lay-out of towns and the real one uncovers the gaps where new towns should be established in the future, and points out the locations where no further urban development should be encouraged.     

Expanding a network of public facilities with some fixed supply points

Conclusions In general terms, this paper has demonstrated how the expansion of public facilities can be phased and implemented within the framework of certain policy objectives. Given an existing network of hospitals, for instance, it is possible to plan and implement the provision of additional facilities in a manner that enhances the spatial efficiency of the expanded network. The expansion can be executed in such a way that with the addition of each new facility, not only is aggregate travel minimized, but also a specified proportion of the population can be brought within easy reach of hospital services. This method is a particularly useful one because in planning the location of facilities, authorities hardly ever start off with a clean slate. Usually some facilities of the same kind might already be occupying some locations which may or may not be optimal. But whether or not the already existing network is optimal, the overall efficiency of the expanded network can be enhanced by proceeding in the manner outlined above.This method can be applied to a wide range of public facilities, like schools for instance. But its application depends, among other things, on the clear definition of locational and policy objectives. Different objectives could produce different locational patterns. Even variations in the measures of distance used can produce different locational patterns.     

On optimization algorithms for the reservoir oil well placement problem

Determining optimal locations and operation parameters for wells in oil and gas reservoirs has a potentially high economic impact. Finding these optima depends on a complex combination of geological, petrophysical, flow regimen, and economical parameters that are hard to grasp intuitively. On the other hand, automatic approaches have in the past been hampered by the overwhelming computational cost of running thousands of potential cases using reservoir simulators, given that each of these runs can take on the order of hours. Therefore, the key issue to such automatic optimization is the development of algorithms that find good solutions with a minimum number of function evaluations. In this work, we compare and analyze the efficiency, effectiveness, and reliability of several optimization algorithms for the well placement problem. In particular, we consider the simultaneous perturbation stochastic approximation (SPSA), finite difference gradient (FDG), and very fast simulated annealing (VFSA) algorithms. None of these algorithms guarantees to find the optimal solution, but we show that both SPSA and VFSA are very efficient in finding nearly optimal solutions with a high probability. We illustrate this with a set of numerical experiments based on real data for single and multiple well placement problems.     

Pseudo-cross variograms, positive-definiteness, and cokriging

Cokriging allows the use of data on correlated variables to be used to enhance the estimation of a primary variable or more generally to enhance the estimation of all variables. In the first case, known as the undersampled case, it allows data on an auxiliary variable to be used to make up for an insufficient amount of data. Original formulations required that there be sufficiently many locations where data is available for both variables. The pseudo-cross-variogram, introduced by Clark et al. (1989), allows computing a related empirical spatial function in order to model the function, which can then be used in the cokriging equations in lieu of the cross-variogram. A number of questions left unanswered by Clark et al. are resolved, such as the availability of valid models, an appropriate definition of positive-definiteness, and the relationship of the pseudo-cross-variogram to the usual cross-variogram. The latter is important for modeling this function.