Operations In Urban Areas Research Articles

A Perception-Based Fuzzy Route Planing Algorithm for Autonomous Unmanned Ground Vehicles

Path planning plays an integral role in mission planning for ground vehicle operations in urban areas. Determining the optimum path through an urban area is a well-understood problem for traditional ground vehicles; however, in the case of autonomous unmanned ground vehicles (UGVs), additional factors must be considered. For an autonomous UGV, perception algorithms rather than platform mobility will be the limiting factor in operational capabilities. For this study, perception was incorporated into the path planning process by associating sensor error costs with traveling through nodes within an urban road network. Three common perception sensors were used for this study: GPS, LIDAR, and IMU. Multiple set aggregation operators were used to blend the sensor error costs into a single cost, and the effects of choice of aggregation operator on the chosen path were observed. To provide a robust path planning ability, a fuzzy route planning algorithm was developed using membership functions and fuzzy rules to allow for qualitative route planning in the case of generalized UGV performance. The fuzzy membership functions were then applied to several paths through the urban area to determine what sensors were optimized in each path to provide a measure of the UGV’s performance capabilities. The research presented in this paper shows the impacts that sensing/perception has on ground vehicle route planning by demonstrating a fuzzy route planning algorithm constructed by using a robust rule set that quantifies these impacts.

Numerical Modeling of Ground Movement due to Twin Tunnel Structure of Esfahan Subway, Iran

Tunneling operations in urban areas are always associated with surface and subsurface ground movement, which may affect the stability of nearby structures and utilities. One of the main issues in the analysis and design of tunnels, is ground movement after the support systems and settlement systems caused by excavation. This paper takes the discrete element calculation software of Universal Distinct Element Code (UDEC) to set three dimensional calculations models to simulate the construction of Esfahan subway tunnel, analyzing the displacement and stress dynamic response during the construction process. The paper also carries out the comparison analysis of the field measurement of the ground movement. The result indicates that the simulation objectively reflected the rules of movement during the construction process. The results show that the tunnels are stable before support system installation and the tunnel induced movement is allowable.

Investigation of a novel VTOL aircraft concept for operations in urban areas

Investigation of a novel VTOL aircraft concept for operations in urban areas

A Diagnosis Methodology for Urban Goods Distribution: A Case Study in Belo Horizonte City (Brazil)

Currently, one of the main problems related to freight delivery is the lack of adequate infrastructure for operations in urban areas. In this sense, this paper presents a diagnosis methodology to identify issues relating to urban goods distribution To undertake the diagnosis, we used interviews with logistics operators, research of of loading and unloading places and traffic counts in the study area. The methodology was applied to the central area of Belo Horizonte (MG), and among the results highlight that the loading and unloading places regulated by public authorities on urban roads are occupied mostly by private vehicles. The results indicate the main issues relating to urban freight distribution in Belo Horizonte and the need for effective public policies to improve the activity and the reduction of negative externalities on the urban environment.

Diagnóstico das vagas de carga e descarga para a distribuição urbana de mercadorias: um estudo de caso em Belo Horizonte

Atualmente, um dos principais problemas relacionados à distribuição de mercadorias é a falta de infraestrutura adequada para as operações na área urbana. Neste sentido, este artigo apresenta uma metodologia para diagnóstico da operação da distribuição urbana através de uma estrutura de variáveis relacionadas à logística urbana. Para a elaboração do diagnóstico, utilizou-se de entrevista com os operadores logísticos, pesquisa de rotatividade das vagas de carga e descarga e contagem de veículos na área de estudo. A metodologia foi aplicada para a área central de Belo Horizonte (MG) e, dentre os resultados, destaca-se que as vagas de carga e descarga regulamentadas pelo poder público nas vias urbanas são ocupadas, majoritariamente, pelos veículos particulares. Desta maneira, conclui-se ser necessárias soluções de gerenciamento de estacionamento, sinalização horizontal e vertical, além da fiscalização intensiva como forma de reduzir os índices de infração observados e, usar racionalmente as baias para a melhoria das operações de carga urbana em vias públicas. Ainda, a estrutura de variáveis relacionada à logística urbana consiste na contribuição metodológica do trabalho.

Local Authority Cooperation with Urban Freight Stakeholders: A Comparison of Partnership Approaches

Freight transport operations in urban areas are normally performed by private companies using public infrastructure and governed by regulations implemented by public authorities. Until recently there has been little involvement of private companies in local transport planning processes and as a result urban transport regulations and plans are frequently formulated with limited understanding of the impacts on freight transport operations. In the UK, freight partnerships have been developed to bring together public and private stakeholders often in an urban context and there are other examples elsewhere in Europe. Few of these partnerships have been assessed in order to compare their activities systematically. The paper compares several freight partnerships and considers their usefulness and possible shortcomings in terms of specific outcomes and projects as well as their input to and influence on policy formulation. Six partnerships are investigated by means of desk research, interviews and questionnaires and in two cases participation by the researchers. The freight partnerships are compared using an assessment framework derived from the literature review conducted. Results show that shortterm actions solving specific problems are valued but are not perceived as the sole benefit of the partnerships. Longer-term relationships and mutual understandings of each other’s problems and possibilities are considered equally important especially in respect of input to policy formulation by the local authorities. The results also show that one of the most important factors to support the on-going activities of a partnership is a core set of engaged and interested participants and several ways in which this can be achieved have been identified.

Veterinary urban hygiene: a challenge for India

India is confronted with many hygiene problems in urban areas that are related to animal populations. While some of these issues have been present for many years, others are only now emerging. A livestock census in 2003 and another in 2007 revealed that populations of crossbred cattle, goats and poultry are all increasing in urban areas, since this enables easy market access, which, in turn, reduces transportation costs and adds to profits. The canine population has increased along with the human population, largely due to a lack of control measures such as impounding stray animals and euthanasia. These increases in populations of both food-producing animals and stray animals in cities exacerbate such public health hazards as the transmission of zoonoses, vector-borne diseases, occcupational health hazards and environmental pollution, as well as compromising animal welfare. At present, public health hazards due to urban animal husbandry practices are considerably under-estimated. To improve veterinary-related urban hygiene and to facilitate livestock production operations in urban areas, there is an urgent need to develop sound, science-based strategies enforced through stringent regulations. The use of One Health teams may provide an answer to these highly integrated public health problems.

The Battle for Jaffa, 1948

Modern armies conduct military operations in urban areas, but rarely do so willingly. Military commanders prefer fighting in open terrain in which forces freely maneuver and use firepower, rather than in urban areas in which obstacles such as tall buildings, narrow streets, and non-combatants hinder control of the battlefield. Most professional military literature recommends refraining from fighting in urban areas and considering urban battles an unfortunate aberration to be avoided in the future. Deliberate choice of an urban battlefield is quite exceptional, deriving mostly from strategic needs or due to the symbolic value ascribed to a particular city or town. Most decisive battles of the first Arab-Israeli war in 1948 were fought in open areas. However, strategic and political considerations, as well as cultural and sentimental, caused both sides to fight in cities and towns, such as in the case of Jaffa and Tel Aviv metropolitan area, Palestine's major economic center and a main road junction. Both cities also held sentimental value: the dynamically developing modern Jaffa was a symbol of an emerging Palestinian nation while Tel Aviv, the “first Hebrew city,” was the Zionist ideal of urban development.

Migration of Gas from Oil/Gas Fields

The migration of gas from oil and gas fields to the surface is a problem that can greatly affect areas of urban development. Oilfields have demonstrated a long history of gas migration problems. Experience has shown that the migration of gas to the surface can create a serious potential risk of explosion, fires, noxious odors, and potential emissions of carcinogenic chemicals, such as BTEX. These risks must be seriously examined for any oil and/or gas operations in urban areas. Oilfield operations, however, can be conducted safely if proper precautions are taken.

Military operations in urban areas

AbstractArmies have traditionally avoided cities and siege operations. Fighting for and in cities is costly, slow, and often inconclusive. But sometimes they are unavoidable, either because they are located on main road or rail junctions or because of their value as political and/or economic prizes. Urban expansion in both north and south has made cities today the main theatres of military and humanitarian operations.Armies' structures, equipment, and doctrines are undergoing a process of adaptation. Manoeuvre has given way to fire power and protection for the troops as the decisive elements of military power. While heavy fire power does considerable damage and causes civilians to flee their homes, operations using protection techniques are only suitable for stabilization. Moreover, their success depends essentially on the willingness of troops to make sacrifices, and on support from the public.

Light goods vehicles in urban areas

The paper provides a review of the light goods vehicle (LGV) fleet and its activity, with specific reference to operations in urban areas, and sustainability issues associated with the ever-growing use of LGVs. Traditionally these vehicles have received little attention but are becoming an ever-more important element of urban freight transport both for goods collection and delivery and for the provision of a wide range of critical services. Relevant literature from the UK and elsewhere pertaining to LGV operations and their impacts has been identified and utilised. The paper identifies the impacts of LGV operations in terms of economic, social and environmental impacts and presents the range of measures being taken by policy makers and companies to address negative impacts.

Vehicle Routing for Urban Snow Plowing Operations

Winter road maintenance planning involves a variety of decisions related to the routing of vehicles for spreading chemicals and abrasives, plowing roadways and sidewalks, loading snow into trucks, and transporting snow to disposal sites. In this paper, we present a model and two heuristic solution approaches based on mathematical optimization for the routing of vehicles for snow plowing operations in urban areas. Given a district and a single depot where a number of plows are based, the problem is to determine a set of routes, each performed by a single vehicle that starts and ends at the district's depot, such that all road segments are serviced while satisfying a set of operational constraints and minimizing a time objective. The formulation models general precedence relation constraints with no assumption on class connectivity, different service and deadhead speed possibilities, separate pass requirements for multilane road segments, class upgrading possibilities, and vehicle road segment dependencies. Several extensions, such as turn restrictions, load balancing constraints, and tandem service requirements, which are required in a real-life application, are also discussed. Two objectives are considered: A hierarchical objective and a makespan objective. The resulting model is based on a multicommodity network flow structure to impose the connectivity of the route performed by each vehicle. The two solution strategies were tested on data from the City of Dieppe, New Brunswick, Canada.

Military Operations in Urban Areas: The Indian Experience

Military Operations in Urban Areas: The Indian Experience

A rule-based real-time traffic responsive signal control system with transit priority: application to an isolated intersection

Previous experience has shown that real-time, traffic-responsive signal control has the ability to improve traffic operations in urban areas when compared to traditional fixed-time control. However, most of these experiences have focused primarily on the impact on private automobiles. This paper describes the development and evaluation of a fully distributed, real-time, traffic-responsive model named Signal Priority Procedure for Optimization in Real-Time (SPPORT) that explicitly considers the impacts of transit vehicles. This model is unique in two ways. First, the model explicitly considers the interference caused to the general traffic by transit vehicles stopping in the right of way to board and discharge passengers. Second, when considering priority passage for transit vehicles, the potential effects that such preferential treatment might have on other traffic are explicitly quantified. This paper describes the structure of the model and demonstrates its capabilities on an isolated intersection for a range of traffic demands and with and without transit vehicles. The rule-based signal optimization procedure provided delay reductions for most of the traffic conditions examined when compared to both fixed-time and traffic actuated control. While the results reported in this paper are limited to an isolated intersection, the model is capable of being applied to a network of signals. Evaluation of its performance on a corridor has been conducted and will appear in the literature in the near future.

3D mapping of an interactive synthetic environment

Traditional geospatial information systems (GIS) use geographically referenced data to produce highly accurate digital maps. These two-dimensional maps include well-recognized symbols that represent features such as mountains, forests, buildings, and transportation networks. Although this flat view provides an excellent means of orienting the user to the general nature and location of the geographic features for a given area, it does not provide the full experiential value that comes from immersion within a 3D environment. The authors, working in conjunction with the University of New Orleans' Computer Science Department, developed a 3D-GIS to assist the US Marine Corps with mission preparation and rehearsal. It also provides on-site awareness during actual field operations in urban areas. Going beyond presenting stereoscopic views of an area or merely applying photo textures to highly simplified geometric shapes, they created an environment that replicates its real-world counterpart by including detailed 3D objects. The article details the design considerations they faced as well as the implementation and structural overview for the entire system.

仙台市における宿泊機能の立地特性

The objective of this study is to examine the centrality of Sendai City in the regional urban system in the Tohoku district through the analysis of agglomeration processes and locational patterns of lodging facilities and their operations in urban areas. Japanese lodging facilities can be divided into two main categories : Japanese style lodging, called ryokans, and western style hotels.Most lodging facilities in the Tohoku district were composed of ryokans in the 1960s. When the size and number of hotels began to increase rapidly in Sendai in the early 1970s, western style hotels multiplied in the Tohoku district, following the trend that occurred in the main metropolitan regions of Tokyo-Yokohama and Kyoto-Osaka-Kobe. The increase in the number of hotels in Sendai, as well as in Sapporo, Hiroshima and Fukuoka in this period, signifies that hotel construction diffused from the largest cities to regional central cities following the national urban hierarchy.After the first increase in hotels in Sendai, hotel construction diffused to prefectural capitals and other major cities in the Tohoku district. This agglomeration process reflected the spatio-temporal differences among the cities. Each city is different in terms of population size and growth, urban functions and access to major transportation networks. In Morioka City, for example, the number of hotels increased rapidly in the early 1980s, after the opening of the Tohoku-Shinkansen (Tokyo-Morioka), which connected the northern Tohoku district with Sendai or Tokyo. The opening of the Tohoku-Shinkansen also resulted in the second rapid hotel increase in Sendai.While the number of ryokans in urban areas has remained stable or has decreased since the 1970s in the Tohoku district, locational patterns of ryokans and hotels have changed considerably, especially in Sendai. In 1970, the majority of hotels were ryokans, which were densely located, traditionally in the CBD and its surrounding areas in Sendai. However, after the first and second phase of new hotel construction, ryokans located in the CBD decreased rapidly because of rising land prices and the construction of high-rise buildings. As a result, in 1996 the western style hotels were clustered in the CBD, while ryokans remained dispersedly in the surrounding CBD areas. However, few hotels were located in the core of Sendai's CBD near the station because this area had already been developed before the first increase in the number of hotels.The rapid and large-scale increase in the number of hotels in Sendai was a result of an increase in the range of services that they provided. Most of the hotels constructed during the first period of increase were commercial hotels catering to the needs of tourists. Therefore, the main function of their hotels was lodging. However, many hotels that were built during the second period of increase were equipped with convention facilities. Thus, hotel operations started to revolve around banquets, conventions and restaurant dining. These operations, especially large-scale convention halls, also attracted business customers from Tokyo and the Tohoku district.The agglomeration processes of lodging facilities reflect the regional urban system and urban structure, and the functions of lodging facilities signify the geographical characteristics and the centrality of Sendai.

Cooperative Extension's Urban Expansion

In 1914, Congress established the Cooperative Agricultural Extension Service. This unique and complex educational system is a three-way cooperative relationship between the U.S. Department of Agriculture, land-grant colleges and universities, and several thousand county governments. The Extension Service was created to disseminate scientific information (generated at the land-grant institutions) to farmers and their families in order to improve agricultural production and the quality of rural life. In recent years, however, Extension's leadership has made a commitment to expand the system's operations in urban areas. This expansion has sparked an intense debate regarding the interpretation of Extension's mission. Using various approaches to statutory interpretation as an analytical framework, this article seeks to answer the question, Is Extension's urban expansion a failure of leadership or a responsiveness to changing times?

On the Evolution and Changes of Individual Economy and Countermeasures

How individual economy remains in existence and moves forward [in our country] is a tortuous experience. In 1952 the absolute majority of China's farming population were individual peasants. And there were 8.83 million individual [or self-employed] laborers residing in cities and towns. The sector of individual economy made up 72 percent of the entire national income. Through the socialist transformation in 1956, individual peasants rapidly moved onto the path of cooperativization, and individually owned industrial and commercial operations in urban areas also switched to cooperative economy. In consequence, the individual economic sector plunged to only 7.1 percent of the national income, and individual laborers in cities and towns were reduced to a measly 160,000. During the three years of adjustment, the ranks of individual laborers bounced back to over 2 million. An even more leftist policy was enforced in the period of the Cultural Revolution, which brought individual economy in town and country to...

Environmental protection measures during construction of the prague subway by drill-and-blast tunnelling

The authors present recommendations for limiting the effects of blasting during tunnelling operations in urban areas. The paper discusses activities necessary at the planning, design and construction stages, e.g. report of geologic conditions, determination of allowable seismic vibrations and blasting parameters, monitoring. Criteria for evaluating side effects of blasting are discussed in relation to both protecting inhabitants from noise and vibration effects; and protecting buildings and infrastructure from seismic and air-blast effects. The authors also present a new system for classifying various types of structures based on their resistance to vibration. Les auteurs présentent des recommendations pour limiter les effects des explosions lors de travaux tunneliers em milieu urbain. L'article discute des activités nécessaires lors de la préparation, de la conception et de la construction (rapport sur les données géologiques, détermination des vibrations séismiques possibles et paramétres d'explosions,pilotage). Les critéres pour évaluer les effets secondaires d'une explosion sont discutés en fonction de la protection contre le bruit et des vibrations des habitants; de la protection des bâtiments et des structures contre les effets séismiques et dáir propulsé. L'auteur présente un nouveau systéme de classification des structures en fonction de leur résistance aux vibrations.

Acquisition Targets and Motives: The Case of the Banking Industry

Findings do not indicate poorly-managed firms are more likely to be acquired than well-managed firms. The analysis uses a sample of 1,046Texas banks that existed in 1970, out of which 201 were acqui red during the period 1970-82. A multinomial logit procedure is used to estimate the relationship between the likelihood of acquisition and the characteristics of the target firm and its market. Additional results suggest that firms with la rge market shares, low capital/asset ratios, and operations in urban areas are r elatively likely to be acquired but not firms with low profits or low growth. Copyright 1987 by MIT Press.