Perceptions of destinations don’t change much over time

One of the most popular topics in tourism research is destination image. That is, measuring consumers’ perceptions of a destination. The importance of the topic is a no brainer given travellers are spoilt by choice of destinations, and that the images they hold of a place are as important as the tangible tourism features. This is underpinned by the old adage perception is reality, a theory promoted by two academics back in 1928 who proposed “what people believe to be true will be real in its consequences”. So, every place marketer knows consumer perceptions play a major role in the competitiveness of their destination.

Commodity taxation and parallel imports

We examine the interaction between commodity taxes and parallel imports in a two-country model with imperfect competition. While governments determine non-cooperatively their commodity tax rate, the volume of parallel imports is determined endogenously by the retailing sector. We compare the positive and normative implications of having commodity taxes based on destination or origin principle. We show that, as the volume of parallel imports increases, non-cooperative origin taxes converge, while destination taxes diverge. Moreover, origin taxes are more similar and lead to higher aggregate welfare levels than destination taxes.

Tax principles and tax harmonization under imperfect competition: A cautionary example

This paper shows that under imperfect competition, the welfare effects of indirect tax harmonization may depend crucially on whether taxes are levied by the destination or the origin principle. In a standard model of imperfect competition, while harmonization always makes at least one country better off, and may be Pareto-improving, when taxes are levied under the destination principle (which currently applies in the European Union), harmonization of origin-based taxes (as recently proposed by the European Commission) is certain to be Pareto-worsening when the preferences in the two countries are identical, and is likely to be so even when they differ.

Destinations, disasters and public relations: Stakeholder engagement in multi-phase disaster management

Research about disasters in tourism has emerged in earnest since the 1990s covering insights for preparedness and response. However, recently, authors have called for more systematic and holistic approaches to tourism disaster management research. To address this gap, this study adopted a public relations perspective to refocus attention to relationships and stakeholder expectations of destination communities across multiple phases of disaster management. The authors used a mixed method approach and developed a battery of disaster management attributes by conducting interviews and analyzing industry documents and the extant literature. These attributes formed part of a survey of tourism businesses. Exploratory factor analysis resulted in a two factor solution: - i) business disaster preparedness, and; - ii) destination disaster response and recovery. Findings also show that participants reported a gap between the importance and destination performance of these attributes. In particular, tourism businesses perceived destinations did not adequately engage in disaster preparedness activities, which had implications for disaster response and recovery.

The entitled tourist: The influence of psychological entitlement and cultural distance on tourist judgments in a hotel context

This research examines how a tourist’s degree of psychological entitlement (sense of deservingness) influences their responses to hotels that differ in cultural distance. Using a visit to China by Western tourists as a context, an experiment shows that entitled tourists respond more negatively to high cultural distance hotel environments compared with low cultural distance environments. Results are mediated by tourist irritation. Research contributions include demonstrating how entitlement moderates cultural distance effects, revealing tourist irritation as a mechanism that explains these effects, and showing how psychological entitlement influences how tourists react to hotel environments when visiting a foreign destination.

Delay Optimal Scheduling in a Two-Hop Vehicular Relay Network

We study a scheduling problem in a wireless network where vehicles are used as store-and-forward relays, a situation that might arise, for example, in practical rural communication networks. A fixed source node wants to transfer a file to a fixed destination node, located beyond its communication range. In the absence of any infrastructure connecting the two nodes, we consider the possibility of communication using vehicles passing by. Vehicles arrive at the source node at renewal instants and are known to travel towards the destination node with average speed v sampled from a given probability distribution. Th source node communicates data packets (or fragments) of the file to the destination node using these vehicles as relays. We assume that the vehicles communicate with the source node and the destination node only, and hence, every packet communication involves two hops. In this setup, we study the source node's sequential decision problem of transferring packets of the file to vehicles as they pass by, with the objective of minimizing delay in the network. We study both the finite file size case and the infinite file size case. In the finite file size case, we aim to minimize the expected file transfer delay, i.e. expected value of the maximum of the packet sojourn times. In the infinite file size case, we study the average packet delay minimization problem as well as the optimal tradeoff achievable between the average queueing delay at the source node buffer and the average transit delay in the relay vehicle.

A non-orthogonal cooperative multiple access (NCMA) protocol and low ML decoding complexity codes

A half-duplex constrained non-orthogonal cooperative multiple access (NCMA) protocol suitable for transmission of information from N users to a single destination in a wireless fading channel is proposed. Transmission in this protocol comprises of a broadcast phase and a cooperation phase. In the broadcast phase, each user takes turn broadcasting its data to all other users and the destination in an orthogonal fashion in time. In the cooperation phase, each user transmits a linear function of what it received from all other users as well as its own data. In contrast to the orthogonal extension of cooperative relay protocols to the cooperative multiple access channels wherein at any point of time, only one user is considered as a source and all the other users behave as relays and do not transmit their own data, the NCMA protocol relaxes the orthogonality built into the protocols and hence allows for a more spectrally efficient usage of resources. Code design criteria for achieving full diversity of N in the NCMA protocol is derived using pair wise error probability (PEP) analysis and it is shown that this can be achieved with a minimum total time duration of 2N - 1 channel uses. Explicit construction of full diversity codes is then provided for arbitrary number of users. Since the Maximum Likelihood decoding complexity grows exponentially with the number of users, the notion of g-group decodable codes is introduced for our setup and a set of necesary and sufficient conditions is also obtained.

Jointly optimal power control and routing for a single cell, dense, ad hoc wireless network

We consider a dense, ad hoc wireless network confined to a small region, such that direct communication is possible between any pair of nodes. The physical communication model is that a receiver decodes the signal from a single transmitter, while treating all other signals as interference. Data packets are sent between source-destination pairs by multihop relaying. We assume that nodes self-organise into a multihop network such that all hops are of length d meters, where d is a design parameter. There is a contention based multiaccess scheme, and it is assumed that every node always has data to send, either originated from it or a transit packet (saturation assumption). In this scenario, we seek to maximize a measure of the transport capacity of the network (measured in bit-meters per second) over power controls (in a fading environment) and over the hop distance d, subject to an average power constraint. We first argue that for a dense collection of nodes confined to a small region, single cell operation is efficient for single user decoding transceivers. Then, operating the dense ad hoc network (described above) as a single cell, we study the optimal hop length and power control that maximizes the transport capacity for a given network power constraint. More specifically, for a fading channel and for a fixed transmission time strategy (akin to the IEEE 802.11 TXOP), we find that there exists an intrinsic aggregate bit rate (Theta(opt) bits per second, depending on the contention mechanism and the channel fading characteristics) carried by the network, when operating at the optimal hop length and power control. The optimal transport capacity is of the form d(opt)((P) over bar (t)) x Theta(opt) with d(opt) scaling as (P) over bar (1/eta)(t), where (P) over bar (t) is the available time average transmit power and eta is the path loss exponent. Under certain conditions on the fading distribution, we then provide a simple characterisation of the optimal operating point.

High-rate, Single-Symbol Decodable Distributed STBCs for Partially-Coherent Cooperative Networks

Space-time block codes (STBCs) that are single-symbol decodable (SSD) in a co-located multiple antenna setting need not be SSD in a distributed cooperative communication setting. A relay network with N relays and a single source-destination pair is called a partially-coherent relay channel (PCRC) if the destination has perfect channel state information (CSI) of an the channels and the relays have only the phase information of the source-to-relay channels. In our earlier work, we had derived a set of necessary and sufficient conditions for a distributed STBC (DSTBC) to be SSD for a PCRC. Using these conditions, in this paper we show that the possibility of channel phase compensation operation at the relay nodes using partial CSI at the relays increases the possible rate of SSD DSTBCs from 2/N when the relays do not have CSI to 1/2, which is independent of N. We also show that when a DSTBC is SSD for a PCRC, then arbitrary coordinate interleaving of the in-phase and quadrature-phase components of the variables does not disturb its SSD property. Using this property we are able to construct codes that are SSD and have higher rate than 2/N but giving full diversity only for signal constellations satisfying certain conditions.

OFDM Based Distributed Space Time Coding for Asynchronous Relay Networks

Recently Li and Xia have proposed a transmission scheme for wireless relay networks based on the Alamouti space time code and orthogonal frequency division multiplexing to combat the effect of timing errors at the relay nodes. This transmission scheme is amazingly simple and achieves a diversity order of two for any number of relays. Motivated by its simplicity, this scheme is extended to a more general transmission scheme that can achieve full cooperative diversity for any number of relays. The conditions on the distributed space time block code (DSTBC) structure that admit its application in the proposed transmission scheme are identified and it is pointed out that the recently proposed full diversity four group decodable DST-BCs from precoded co-ordinate interleaved orthogonal designs and extended Clifford algebras satisfy these conditions. It is then shown how differential encoding at the source can be combined with the proposed transmission scheme to arrive at a new transmission scheme that can achieve full cooperative diversity in asynchronous wireless relay networks with no channel information and also no timing error knowledge at the destination node. Finally, four group decodable distributed differential space time block codes applicable in this new transmission scheme for power of two number of relays are also provided.

Providing QoS to Real and Data Applications in WiMAX Mesh Networks

We consider the problem of centralized routing and scheduling for IEEE 802.16 mesh networks so as to provide Quality of Service (QoS) to individual real and interactive data applications. We first obtain an optimal and fair routing and scheduling policy for aggregate demands for different source- destination pairs. We then present scheduling algorithms which provide per flow QoS guarantees while utilizing the network resources efficiently. Our algorithms are also scalable: they do not require per flow processing and queueing and the computational requirements are modest. We have verified our algorithms via extensive simulations.

Single-Symbol ML Decodable Precoded DSTBCs for Cooperative Networks

Single-symbol maximum likelihood (ML) decodable distributed orthogonal space-time block codes (DOST- BCs) have been introduced recently for cooperative networks and an upper-bound on the maximal rate of such codes along with code constructions has been presented. In this paper, we introduce a new class of distributed space-time block codes (DSTBCs) called semi-orthogonal precoded distributed single-symbol decodable space-time block codes (Semi-SSD-PDSTBCs) wherein, the source performs preceding on the information symbols before transmitting it to all the relays. A set of necessary and sufficient conditions on the relay matrices for the existence of semi-SSD- PDSTBCs is proved. It is shown that the DOSTBCs are a special case of semi-SSD-PDSTBCs. A subset of semi-SSD-PDSTBCs having diagonal covariance matrix at the destination is studied and an upper bound on the maximal rate of such codes is derived. The bounds obtained are approximately twice larger than that of the DOSTBCs. A systematic construction of Semi- SSD-PDSTBCs is presented when the number of relays K ges 4 and the constructed codes are shown to have higher rates than that of DOSTBCs.

Visibility volumes for interactive path optimization

We describe a real-time system that supports design of optimal flight paths over terrains. These paths either maximize view coverage or minimize vehicle exposure to ground. A volume-rendered display of multi-viewpoint visibility and a haptic interface assists the user in selecting, assessing, and refining the computed flight path. We design a three-dimensional scalar field representing the visibility of a point above the terrain, describe an efficient algorithm to compute the visibility field, and develop visual and haptic schemes to interact with the visibility field. Given the origin and destination, the desired flight path is computed using an efficient simulation of an articulated rope under the influence of the visibility gradient. The simulation framework also accepts user input, via the haptic interface, thereby allowing manual refinement of the flight path.

Le Grand Tour Du reste de l’Europe jusqu’à la Laponie – et retour

Rencontre entre le Sud et le Nord Depuis des siècles, les pays méditerranéens ont entretenu des relations actives avec le Nord de l’Europe. Les regions du Nord ont été conquises et converties, manipulées et colonisées, mais aussi intégrées dans les réseaux commerciaux, scientifi ques, culturels et touristiques. Les voyageurs du Sud de l’Europe ont peu à peu découvert les regions plurielles du Nord de la Finlande, de la Suède, de la Norvège et de la presqu’île de Kola. L’attraction focntionnait aussi dans l’autre sens. Pour les gens du Nord, scientifi ques ou artistes, le Sud de l’Europe constituait une destination aussi exotique aue la Laponie pour ceux du Sud. Dans ce recueil, nous proposons dix points de vue sur ces échanges et réseaux entre la Sud et le Nord. Le premier chapitre présente Tornio, connue très tôt comme la porte de la Laponie, les premières relations scientifi ques entre le Nord et le Sud, ainsi que les exhibitions de Samis dans les métropoles européennes. Le deuxième chapitre propose une analyse des experiences et des impressions de voyageurs italiens, espagnols et français. Le dernier chapitre est consacré aux voyages d’artistes et écrivains fi nlandais en France, principalement à Paris. Ces rencontres entre le Sud et le Nord qui participèrent à la remise en cause, la relativisation et la construction des identities nationals et ethniques, permirent aussi de créer une conscience européenne commune.

A non-orthogonal distributed space-time coded protocol - Part 1:Signal model and design criteria

In this two-part series of papers, a generalized non-orthogonal amplify and forward (GNAF) protocol which generalizes several known cooperative diversity protocols is proposed. Transmission in the GNAF protocol comprises of two phases - the broadcast phase and the cooperation phase. In the broadcast phase, the source broadcasts its information to the relays as well as the destination. In the cooperation phase, the source and the relays together transmit a space-time code in a distributed fashion. The GNAF protocol relaxes the constraints imposed by the protocol of Jing and Hassibi on the code structure. In Part-I of this paper, a code design criteria is obtained and it is shown that the GNAF protocol is delay efficient and coding gain efficient as well. Moreover GNAF protocol enables the use of sphere decoders at the destination with a non-exponential Maximum likelihood (ML) decoding complexity. In Part-II, several low decoding complexity code constructions are studied and a lower bound on the Diversity-Multiplexing Gain tradeoff of the GNAF protocol is obtained.