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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
111

Identifying barriers to the implementation of bus policy at a local level in Great Britain using a decision support framework

McTigue, Clare January 2018 (has links)
The current debate on transport policy in the UK is focused on the need for a sustainable transport system. Buses play a vital role in achieving this, as they are the most frequently used and most accessible mode of public transport. However, the literature shows that the delivery of sustainable transport policies is not producing the desired outcomes (Hull, 2009) and the application of such policies in real situations remains inconsistent. This is evident across the UK where there has been a decrease in bus patronage and bus mileage. To address this gap, the aim of this research is to identify why bus policies are not imple-mented successfully at a local level and to provide recommendations for implementation and decision making that will aid policy makers, local authority staff, regional transport partnerships, bus operating companies and other practitioners working within the field of transport. A mixed methodology was chosen for this research and is divided into three key stages to address the research problem. The first methodology included an online ques-tionnaire and 143 questionnaires were sent to all public transport officers in Great Britain. 80 surveys were returned giving a response rate of 56%. The second methodology in-cluded telephone interviews conducted with 10 of those public transport officers who responded to the questionnaire in order to elicit a deeper understanding of the results, which could not be achieved from the questionnaire results alone. Finally, the third meth-odology included four case studies on specific bus schemes within Great Britain. These case studies were the Quality Contract Scheme in Tyne and Wear, Fastlink Scheme in Glasgow, Bus Priority Scheme in Solihull and Smart Ticketing Scheme in Dundee. While the questionnaires and telephone interviews provide an overview of bus policy imple-mentation across Great Britain, the multiple case studies were required to investigate the topic in depth, thus identifying the greatest barriers to bus policy implementation. Analysis of the three sets of data is based on the application of a new decision support frame-work developed in this research. The findings in this thesis reveal that local authorities in Great Britain are under-performing in the implementation of bus policy due to the barriers they face. The greatest barriers to implementation include the lack of a policy document; the characteristics of the organisation; availability of resources; intra-organisation support and communication; economic, social and political environments; and opposition, conflict, and ambiguities. Overall, this research has identified several concerns with bus policy implementation. The most obvious concern is the unclear link between policy objectives and measures and the setting and monitoring of performance targets. Meanwhile, the deregulation of the bus sector in the UK means that, in some cases, a lack of control over the implementation of certain measures places limits on policy implementation and results in the frequent im-plementation of policy measures that are achievable rather than those that are necessary to the achievement of policy objectives. The findings from this research also help policy-makers and transport planners to predict what makes implementation successful and to address problems and issues through improved policies and regulations, as well as to an-ticipate and plan for likely barriers. Moreover, addressing these barriers can help tackle the decline in bus mileage and bus usage across Great Britain.
112

Radrennen und Dauerfahrten in der Oberlausitz: Teil 3 einer offenen Spurensuche

Bemme, Jens 28 April 2021 (has links)
Die Geschichte des Radfahrens in der Lausitz um 1900 ist noch nicht auserzählt. Regionale Radfahrer-Bünde sind nur ein Aspekt der Mobilitäts- und Sportgeschichte: LRB, OLRB, SRB, DRB, ARU und „Solidarität“ hießen damals die Radfahrer-Bünde, um nur einige zu nennen. Örtliche Radfahrervereine, die Fahrradproduktion, Handel und Reparaturwerkstätten und darüber hinaus die frühe Verbreitung des Fahrrads in der Ober- und Niederlausitz sind Aspekte, die weiter erforscht werden können. Radrennen und Dauerfahrten in der Oberlausitz sind Inhalt des vorliegenden Artikels, der einerseits einen Einstieg in neue Recherchen bietet und andererseits Quellen und Methoden für diese Art der Spurensuche diskutiert. [... aus dem Artikel]
113

Healthy and pleasant commuting in cities / Exploring cyclists’ and pedestrians’ personal exposure, wellbeing and protective practices on-the-move

Marquart, Heike 08 June 2023 (has links)
In dieser Doktorarbeit wurde untersucht, welche Faktoren Wohlbefinden, wahrgenommene Gesundheit und Mobilitätspraktiken von Radfahrenden und Fußgänger:innen während des Unterwegsseins beeinflussen. Ziel war es, die persönliche Exposition gegenüber Feinstaub und Lärm unterwegs zu messen und diese der individuell wahrgenommenen Belastung gegenüberzustellen. Zudem wurden weitere Faktoren, die das Wohlbefinden beeinflussen, untersucht. Die Arbeit beleuchtet überdies, wie über gesunde und angenehme Mobilität informiert werden könnte. Zuerst wurden mobile qualitative Interviews (Go-/Ride-Alongs) durchgeführt und mit tragbaren Sensoren zur Messung von Feinstaub und Lärm ergänzt. Der situative Kontext, die sensorische Wahrnehmung und soziale Aspekte beeinflussen, ob das Unterwegsseins in der Stadt als gesund und angenehm empfunden wird. Diese Faktoren können in vergleichsweise als hoch belastend gemessenen Situationen ausgleichend wirken. Weiterhin wurden Informationsmöglichkeiten für eine gesunde Mobilität in der Stadt exploriert. Ein Literaturreview hat aufgezeigt, dass Gesundheitsthemen wenig Berücksichtigung in Forschung zu Mobilitäts-Apps finden. Daran anschließend wurden Fokusgruppen durchgeführt. Es wurde ermittelt, wie gesunde und angenehme Routen kommuniziert werden können. Hier könnendas Vorhandensein von Routenalternativen und Bewältigungsstrategien ein Gefühl von Selbstwirksamkeit geben. Es wurde eine „pleasant routing app“ vorgeschlagen, die angenehme und gesunde Routenaspekte integriert. Um die Attraktivität des Fahrradfahrens und zu Fuß Gehens zu steigern, sollten Erfahrungen, Wahrnehmungen und Praktiken von Radfahrenden und Fußgänger:innen berücksichtigt werden. Letztendlich kann somit aktive Mobilität ihr Potenzial entfalten und zu einer lebenswerten, gesunden und umweltfreundlichen Stadt beitragen. / This thesis investigates factors influencing cyclists’ and pedestrians’ health and wellbeing on-the-move. Moreover, the possibilities of smartphone apps for supporting a healthy and pleasant trip are investigated. The scope of this thesis is to combine the topic healthy and pleasant mobility with possibilities of mobility apps. First, the thesis explores how cyclists and pedestrians perceive their personal exposure towards air pollution and noise as well as other factors influencing commuting experience and wellbeing on-the-move. This is contrasted to actual measured particulate matter and noise. Qualitative interviews on-the-move (‘go-/ride-alongs’) are complemented by wearable sensors measuring particulate matter and noise. The results show discrepancies as well as coherences between perceived and measured exposure. The situational context, sensory awareness (e.g. water views) and social cues (e.g. seeing other people) are important for a perceived pleasant commute, even in polluted areas. Second, this thesis identifies how far health impacting factors are considered in research using mobility apps to identify their possibilities for supporting a healthy commute. A literature review reveals that research applying mobility apps is lacking the consideration of health topics and it is proposed to integrate health topics in mobility app development. Following these findings, the thesis investigates communication options to inform about a healthy and pleasant commute. Focus groups were applied showing that information should include feasible coping strategies and increase self-efficacy. Pleasant trip characteristics could be included in a healthy mobility app. If active mode users’ experiences, perceptions and practices are considered, cycling and walking can become more attractive and more people are encouraged to cycle or walk. Hence, active modes can unfold their potential for supporting the transformation towards liveable, healthy and environmentally friendly cities.
114

Complex transportation networks : resilience, modelling and optimisation

Holovatch, T. January 2011 (has links)
The present thesis is devoted to an application of the ideas of complex networks theory for analysing, modelling, and, finally, optimising different processes that occur in transportation networks.
115

Παλαιογεωγραφική ανάπλαση των αρχαίων λιμένων Ζέας και Μικρολίμανου (Μουνιχία) με εφαρμογή γεωφυσικών μεθόδων

Ζούρα, Δέσποινα 11 July 2013 (has links)
Η αλλαγή στην στάθμη της θάλασσας καθώς και καταστροφικά φαινόμενα που έχουν συμβεί τα τελευταία 10.000 χρόνια έχουν οδηγήσει στην καταβύθιση αρχαίων λιμενικών εγκαταστάσεων. Μέρος των εγκαταστάσεων των αρχαίων λιμένων Ζέας και Μουνιχίας βρίσκονται σήμερα κάτω από το επίπεδο της θάλασσας. Για την μελέτη αυτών, είναι απαραίτητη η χρήση σύγχρονων συστημάτων θαλάσσιας γεωφυσικής διασκόπισης με σκοπό: (α) την κατασκευή λεπτομερούς βυθομετρικής αποτύπωσης στους αρχαίους λιμένες Ζέας και Μουνιχίας καθώς και των παράκτιων περιοχών πλησίον τους, (β) την μελέτη της στρωματογραφίας της ακολουθίας ιζημάτων (γ) τον προσδιορισμό της παλαιογεωγραφικής εξέλιξης της περιοχής Ζέας – Μουνιχίας και (δ) τον εντοπισμό στόχων, επιφανειακών και υποεπιφανειακών με πιθανό αρχαιολογικό ενδιαφέρον. Οι θαλάσσιες γεωφυσικές έρευνες πραγματοποιήθηκαν τον Νοέμβριο του 2011 από το Ε.ΘΑ.ΓΕ.Φ.Ω σε συνεργασία με το Danish Institute και το Zea Project. Στην παρούσα διπλωματική αναλύθηκαν και επεξεργάστηκαν τα γεωφυσικά δεδομένα που συλλέχθηκαν με τομογράφο υποδομής πυθμένα 3.5 kHz, ηχοβολιστή πλευρικής σάρωσης (EG&G 272 TD) καθώς και βυθόμετρο (Elac Nautic Hydrostat). Η μελέτη στης σεισμοστρωματογραφίας με τομογράφο υποδομής πυθμένα έδειξε τρεις σεισμικές ιζητογενείς ακολουθίες για κάθε έναν από τους αρχαίους λιμένες και οδήγησε στην κατασκευή χάρτη ισοπαχών. Οι τρείς ακολουθίες πιθανώς σχετίζονται με διαφορετικές χρονικές περιόδους των λιμένων. Τα δεδομένα του ηχοβολιστή πλευρικής σάρωσης εντόπισαν περιοχές του πυθμένα των λιμένων που πιθανώς σχετίζονται με αρχαίες κατασκευές. Επιπλέον από τα δεδομένα του ηχοβολιστή πλευρικής σάρωσης προέκυψαν χάρτες μορφολογικής αποτύπωσης του πυθμένα καθώς και στόχοι με πιθανό αρχαιολογικό ενδιαφέρον. Συγκεκριμένα εντοπίστηκε ένας μεγάλος αριθμός στόχων που χαρακτηρίζονται από εύρος τιμών όσον αφορά στις γεωμετρικές παραμέτρους και στις παραμέτρους ανακλαστικότητας. Το λογισμικό TargAn εφαρμόσθηκε για την παραμετροποίηση όλων των στόχων ενώ επιπλέον εφαρμόσθηκαν στατιστικές τεχνικές πολυδιάστατης ανάλυσης για την ταξινόμηση των στόχων σε ομάδες με βάση την αρχαιολογική τους σπουδαιότητα. / Sea level change and catastrophic events that have occurred in the last 10.000 years have led to the submergence of ancient harbors and facilities. Parts of the facilities of Zea and Mounichia ancient harbors are now below sea level. This research was carried out with use of marine geophysical methods in order to: (a) map with detail the bathymetry of the two harbors and the near shore area, (b) map the seismic stratigraphy of the area, (c) determine the palaeogeographical evolution of the area and (d) to identify targets with possible archaeological interest. Marine geophysical survey took place in October 2011 by Laboratory of Marine Geology and Physical Oceanography in collaboration with the Danish Institute and Zea Harbour Project. Subbuttom profiler, side-scan sonar and echosounder were used. The processing and analysis of the subbuttom profiler data revealed three distinctive acoustic units for each of the ancient harbours and led to a detailed map of isopachs. Those three different units can be related to the two different faces of the harbor. The side-scan sonar data identified areas of the harbors that are related to ancient structures and facilities. From the same data set 65 targets were detected and analyzed with the use of TargAn software in order to classify them based on their archaeological valuation.
116

Dynamic rerouting in multimodal transportation networks / Reroutage dynamique des passagers dans les réseaux de transport multimodaux

Dib, Omar 06 November 2017 (has links)
La mobilité humaine s'organise de nos jours dans un contexte multimodal avec des systèmes de transport particulièrement complexes. Le nombre d'usagers va croissant et de nouveaux modes de transport émergent jour après jour en même temps que de nouveaux comportements de mobilité. En conséquence, les utilisateurs se trouvent généralement confrontés à la nécessité de choisir entre plusieurs possibilités pour se rendre d'un point d'origine à leur lieu de destination. Dans le but de les aider à naviguer facilement à travers ces réseaux complexes, un système efficace d'information voyageurs doit être construit. Grâce à ce système, les opérateurs de transport cherchent non seulement à fournir des itinéraires optimaux, mais aussi des solutions efficaces et fiables en cas de perturbations. En réalité, les passagers ne cherchent pas seulement à minimiser le temps de trajet. Ils ont aussi tendance à considérer d'autres critères tels que le confort et l'effort qu'il s'agit alors d'optimiser. Un système de routage efficace devrait donc tenir compte des préférences de chaque passager. En outre, les modes de transport sont souvent enclins à des retards. La prise en considération de l'incertitude est donc un aspect très important pour un calculateur d'itinéraires. Les itinéraires multimodaux proposés doivent non seulement être réalisables dans un cas statique, mais également suffisamment robustes face à des aléas. En outre, tout en intégrant des contraintes essentielles telles que la capacité limitée des véhicules, une attention particulière devrait aussi être accordée à la complexité temporelle des algorithmes de routage développés. L'objectif principal de cette thèse est d'élaborer une formulation qui permet de représenter adéquatement un réseau de transport multimodal. En nous basant sur cette formulation, nous proposons plusieurs algorithmes de routage. Nous nous concentrons en particulier sur la résolution de problèmes de plus courts chemins dans un contexte mono/multicritère dans un réseau de transport dynamique et stochastique. Des métaheuristiques telles que les Algorithmes Génétiques (GA), la méthode de Recherche à Voisinage Variable (VNS) et les Algorithmes Mémétiques (MA) ont été utilisés pour fournir des résultats en temps réel. La performance de calcul a été évaluée en résolvant des requêtes de routage à l'échelle du réseau de transport de la Région française Île-de-France. Les résultats indiquent que les nombreuses instances traitées ont été résolues dans un laps de temps raisonnable et que nos algorithmes de routage sont suffisamment performants pour être intégrés dans un calculateur d'itinéraire multimodal opérationnel. / The human mobility is nowadays organized in a multimodal context with more and more complex transport networks. The number of passengers is increasing and new transport modes enter the system day after day simultaneously with new mobility behaviors. As a result, users usually find themselves more confused when choosing between several possibilities to go from one place to their destination. For the sake of helping them to efficiently navigate through this intricate transportation scheme, an efficient Travelers Information System (TIS) has to be built. Thanks to such a system, the transport operators seek not only to provide passengers with optimal itineraries, but also with efficient and reliable solutions in case of disruptions. In fact, commuters do not only seek short time travels, but they usually consider several other criteria such as comfort and effort. An efficient routing system should therefore take into account the various needs and preferences of each passenger. Besides, transport modes are often prone to delays. Thus, handling uncertainty is also a very important aspect of practical journey planning systems. Moreover, the proposed multimodal routes should not only be feasible in a static case, but also robust against the dynamic and stochastic variations of the transport system. Furthermore, crucial constraints should be taken into account such as the capacity limitation of vehicles and the time complexity of the developed routing algorithms. The main objective of this thesis is to propose a formulation that adequately allows representing a multimodal network. Based on our formulation, we elaborate several efficient routing algorithms. In particular, we focus on solving the Earliest Arrival Problem in a single/multiple criteria context, both in dynamic and stochastic environments. To deal with the real time complexity issue, metaheuristics such as Genetic Algorithms (GA), Variable Neighborhood Search (VNS) and Memetic Algorithms (MA) have been used. The computational performance of this work has been assessed by developing a real world route planning system, and solving real life itinerary planning problems defined on the transport network of the French Region Île-de-France that includes the city of Paris and its suburbs. The emerging computational results indicate that the numerous basic and complex instances were solved within a reasonable amount of time and the integration of the proposed routing framework as a module of an operational TIS is relevant.
117

Traffic Modeling and Control at Intelligent Intersections : Time Delay and Fuel Consumption Optimization / Modélisation et contrôle du trafic aux intersections intelligentes : L'optimisation du temps de retard et de la consommation de carburant

Li, Jinjian 07 February 2017 (has links)
La congestion du trafic dans nos villes est un problème qui entrave la qualité de vie. L'intersection est un endroit où les congestions se produisent le plus fréquemment. Par conséquent, au lieu d'étendre les infrastructures, il serait plus intéressant économiquement de s’ocupper de la résolution du problème des retards en développant les stratégies de contrôle de la circulation.Les travaux de cette thèse concerne l’étude des intersections dites « intelligentes » dépourvues de feux de signalisation, et où la coopération est réalisée à partir de la communication véhicule-infrastructure (V2I). L’objectif étant de proposer une modélisation coopérative de ces intersections visant à réduire à la fois les temps de retards et la consommation de carburant.La méthode de résolution du problème comporte deux volets principaux. Le premier volet concerne l'itinéraire devant être choisi par les véhicules pour arriver à leur destination à partir d’un point de départ. Le deuxième volet étant les procédures coopératives proposées afin de permettre aux véhicules de passer rapidement et économiquement à travers chaque intersection. D'une part, selon les informations envoyées en temps réel par les véhicules via la communication V2I à l’intérieur d’une zone de communication, chaque intersection exécute un algorithme soit de « Programmation Dynamique » soit de « Colonie d'Abeilles Artificielles » suivant la taille du trafic et ceci afin de donner aux véhicules l’ordre de passage minimisant le temps de retard dans les intersections. D'autre part, et après avoir reçu l’ordre de passage, chaque véhicule doit calculer son profil optimal de vitesse lui assurant une consommation minimale de carburant.Une série de simulations a ainsi été exécutée sous différents volumes de trafic afin de montrer la robustesse et la performance des méthodes proposées. Les résultats ont aussi été comparés avec d'autres méthodes de contrôle de la littérature et leur efficacité a ainsi été validée. / The traffic congestion is one of the most serious problems limiting the improvement of standing of life. The intersection is a place where the jams occur the most frequently. Therefore, it is more effective and economical to relieve the problem of the heavy traffic delays by ameliorating the traffic control strategies, instead of extending the infrastructures.The proposed method is a cooperative modeling to solve the problem of reducing traffic delays and decreasing fuel consumption simultaneously in a network of intersections without traffic lights, where the cooperation is executed based on the connection of Vehicle-to-Infrastructure (V2I). The resolution contains two main steps. The first step concerns the itinerary. An itinerary presents a list of intersections chosen by vehicles to arrive at their destinations from their origins. The second step is related to the following proposed cooperative procedures to make vehicles to pass through each intersection rapidly and economically: on the one hand, according to the real-time information sent by vehicles in the edge of the communication zone via V2I, each intersection applies Dynamic Programming (DP) or Artificial Bee Colony (ABC) to cooperatively optimize the vehicle passing sequence in intersection with the minimal time delay under the relevant safety constraints; on the other hand, after receiving this sequence, each vehicle finds the optimal speed profiles with the minimal fuel consumption by an exhaustive search.A series of simulation are executed under different traffic volumes to present the performance of proposed method. The results are compared with other control methods and research papers to prove the our new traffic control strategy.
118

Solution Processable Benzotriazole, Benzimidazole And Biphenyl Containing Conjugated Copolymers For Optoelectronic Applications

Kaya Deniz, Tugba 01 September 2012 (has links) (PDF)
The synthesis and optoelectronic properties of biphenyl based conjugated copolymers with varying acceptor units in the polymer backbone were investigated. The well known Donor-Acceptor Theory was used to establish the synthetic pathway for the structural modifications. Solubility issues regarding biphenyl polymer was solved by copolymerizing with soluble units. For this purpose / poly 4-(biphenyl-4-yl)- 4&rsquo / -tert butylspiro[benzo[d]imidazole-2,1&rsquo / -cyclohexane] (P1), poly 4-(biphenyl-4-yl)- 2- dodecyl-2H-benzo[d][1,2,3]triazole (P2) and poly(4-(5-(biphenyl-4-yl)-4-hexylthiophen- 2-yl)-2-dodecyl-7-(4-hexylthiophen-2-yl)-2H-benzo[d][1,2,3]triazole (P3) were synthetized using Suzuki coupling process. Electrochemical properties of these polymers were examined by cyclic voltammetry, spectroelectrochemistry and kinetic studies. Polymers P2 and P3 showed both p- and n-doping behaviors and multicolored electrochromic states. Optical studies revealed that emission color of biphenyl is tuned from blue to orange and the polymers are good candidates for light emitting diode applications. OLED application of P3 was established and outputs of the device were increased by energy transfer studies. The preliminary investigation indicated that P3 possesses promising efficiencies.
119

Polymeric Scaffolds For Bioactive Agent Delivery In Bone Tissue Engineering

Ucar, Seniz 01 October 2012 (has links) (PDF)
Tissue engineering is a multidisciplinary field that is rapidly emerging as a promising new approach in the restoration and reconstruction of tissues. In this approach, three dimensional (3D) scaffolds are of great importance. Scaffolds function both as supports for cell growth and depot for sustained release of required active agents (e.g. enzymes, genes, antibiotics, growth factors). Scaffolds should possess certain properties in accordance with usage conditions. Wet-spinning is a simple technique that has been widely used for the fabrication of porous scaffolds for tissue engineering applications. Natural polymers can effectively be used in scaffold fabrication due to their biocharacteristics. Among natural polymers, chitosan and alginate are two of the most studied ones in tissue engineering and drug delivery fields because of being biologically renewable, biodegradable, biocompatible, non-antigenic, non-toxic and biofunctional. In this study, two kinds of porous scaffolds were produced as chitosan and alginate coated chitosan fibrous scaffolds by wet-spinning technique In order to investigate the delivery characteristics of the scaffolds, loading of gentamicin as a model antibiotic and bovine serum albumin (BSA) as a model protein was carried out in different loading models. Resultant scaffolds were characterized in terms of their structural formation, biodegradation, biomineralization, water uptake and retention ability and mechanical properties. Additionally, release kinetics of gentamicin and BSA were examined. Efficiency of gentamicin on Escherichia coli (E.coli) was examined. Characterization of scaffolds revealed their adequacy to be used in bone tissue engineering applications and capability to be employed as bioactive agent delivery systems.
120

Exports And Clusters: A Spatial Econometric Analysis On Ankara And Istanbul Oizs

Cetin, Dilek 01 September 2012 (has links) (PDF)
Organized Industrial Zones (OIZs) are used as a main and important industry policy tool in Turkey. In 2012, the number of OIZs is 263 with 148 active and 115 planned ones. Network between the firms reveal the knowledge spillovers which is inevitable for economic growth of a country for neo-classical economists. In this thesis, existence of intra-OIZ and intra-industry knowledge spillovers in Ankara and Istanbul is tested by the help of an export decision function. As it considers the spatial dependence between the regional units the spatial econometric method is preferred for the analysis. The data set is taken from the &ldquo / Field Research Survey&rdquo / of Small and Medium Enterprises Development Organization (SMEDO). It consists of 62,137 firm level observations from 24 manufacturing industries in 81 provinces between 2004 and 2007. After the cleaning process of the data, 1545 and 1172 observations are left for Ankara and Istanbul, respectively. The results show that the size of the firm (which is proxied by logarithm of total labor), technology (which is proxied by computer usage), organizational proximity and foreign language knowledge of the administrator are the common determinants of export decision for Ankara and Istanbul for both intra-IOZ and intra-industry relations when spatial dependence is not ignored. Besides these variables, in Ankara percentage of high skilled labor is significant while in Istanbul cluster proximity is significant. Moreover, for Ankara while for intra-OIZ relations the spatial effect is one third of the total effect, it is one fourth of the total effect for intra-industry relation. For Istanbul one fourth of the total effect is from spatial effects for both intra-OIZ and intra-industry relations.

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