Description:
This paper presents a new segmentation technique to use LIDAR point cloud data for automatic extraction of building roof planes. The raw LIDAR points are first classified into two major groups: ground and non-ground points. The ground points are used to generate a 'building mask' in which the black areas represent the ground where there are no laser returns below a certain height. The non-ground points are segmented to extract the planar roof segments. First, the building mask is divided into small grid cells. The cells containing the black pixels are clustered such that each cluster represents an individual building or tree. Second, the non-ground points within a cluster are segmented based on their coplanarity and neighbourhood relations. Third, the planar segments are refined using a rule-based procedure that assigns the common points among the planar segments to the appropriate segments. Finally, another rule-based procedure is applied to remove tree planes which are generally small in size and randomly oriented. Experimental results on three Australian sites have shown that the proposed method offers high building detection and roof plane extraction rates.
Description:
This paper presents a new segmentation technique to use LIDAR point cloud data for automatic extraction of building roof planes. The raw LIDAR points are first classified into two major groups: ground and non-ground points. The ground points are used to generate a 'building mask' in which the black areas represent the ground where there are no laser returns below a certain height. The non-ground points are segmented to extract the planar roof segments. First, the building mask is divided into small grid cells. The cells containing the black pixels are clustered such that each cluster represents an individual building or tree. Second, the non-ground points within a cluster are segmented based on their coplanarity and neighbourhood relations. Third, the planar segments are refined using a rule-based procedure that assigns the common points among the planar segments to the appropriate segments. Finally, another rule-based procedure is applied to remove tree planes which are generally small in size and randomly oriented. Experimental results on three Australian sites have shown that the proposed method offers high building detection and roof plane extraction rates.
Description:
Contour-based corner detectors directly or indirectly estimate a significance measure (eg, curvature) on the points of a planar curve and select the curvature extrema points as corners. A number of promising contour-based corner detectors have recently been proposed. They mainly differ in how the curvature is estimated on each point of the given curve. As the curvature on a digital curve can only be approximated, it is important to estimate a curvature that remains stable against significant noises, for example, geometric transformations and compression, on the curve. Moreover, in many applications, for instance, in content-based image retrieval, a fast corner detector is a prerequisite. So, it is also a primary characteristic that how much time a corner detector takes for corner detection in a given image. In addition, different authors evaluated their detectors on different platforms using different evaluation systems. Evaluation systems that depend on human judgements and visual identification of corners are manual and too subjective. Application of a manual system on a large test database will be expensive. Therefore, it is important to evaluate the detectors on a common platform using an automatic evaluation system. This paper first reviews six most recent and highly performed corner detectors and analyse their theoretical running time. Then it uses an automatic evaluation system to analyse their performance. Both the robustness to noise and efficiency are estimated to rank the detectors.
Description:
Contour-based corner detectors directly or indirectly estimate a significance measure (eg, curvature) on the points of a planar curve and select the curvature extrema points as corners. A number of promising contour-based corner detectors have recently been proposed. They mainly differ in how the curvature is estimated on each point of the given curve. As the curvature on a digital curve can only be approximated, it is important to estimate a curvature that remains stable against significant noises, for example, geometric transformations and compression, on the curve. Moreover, in many applications, for instance, in content-based image retrieval, a fast corner detector is a prerequisite. So, it is also a primary characteristic that how much time a corner detector takes for corner detection in a given image. In addition, different authors evaluated their detectors on different platforms using different evaluation systems. Evaluation systems that depend on human judgements and visual identification of corners are manual and too subjective. Application of a manual system on a large test database will be expensive. Therefore, it is important to evaluate the detectors on a common platform using an automatic evaluation system. This paper first reviews six most recent and highly performed corner detectors and analyse their theoretical running time. Then it uses an automatic evaluation system to analyse their performance. Both the robustness to noise and efficiency are estimated to rank the detectors.
Description:
Automatic 3D extraction of building roofs from remotely sensed data is important for many applications including city modeling. This paper proposes a new method for automatic 3D roof extraction through an effective integration of LIDAR (Light Detection And Ranging) data and multispectral orthoimagery. Using the ground height from a DEM (Digital Elevation Model), the raw LIDAR points are separated into two groups. The first group contains the ground points that are exploited to constitute a `ground mask'. The second group contains the non-ground points which are segmented using an innovative image line guided segmentation technique to extract the roof planes. The image lines extracted from the grey-scale version of the orthoimage are classified into several classes such as `ground', `tree', `roof edge' and `roof ridge' using the ground mask and colour and texture information from the orthoimagery. During roof plane extraction the lines from the later two classes are used to fit roof planes to the neighbouring non-ground LIDAR points. Finally, a new rule-based procedure is applied to remove planes constructed on trees. Experimental results show that the proposed method successfully removes vegetation and offers high extraction rates.
Description:
Automatic 3D extraction of building roofs from remotely sensed data is important for many applications including city modeling. This paper proposes a new method for automatic 3D roof extraction through an effective integration of LIDAR (Light Detection And Ranging) data and multispectral orthoimagery. Using the ground height from a DEM (Digital Elevation Model), the raw LIDAR points are separated into two groups. The first group contains the ground points that are exploited to constitute a `ground mask'. The second group contains the non-ground points which are segmented using an innovative image line guided segmentation technique to extract the roof planes. The image lines extracted from the grey-scale version of the orthoimage are classified into several classes such as `ground', `tree', `roof edge' and `roof ridge' using the ground mask and colour and texture information from the orthoimagery. During roof plane extraction the lines from the later two classes are used to fit roof planes to the neighbouring non-ground LIDAR points. Finally, a new rule-based procedure is applied to remove planes constructed on trees. Experimental results show that the proposed method successfully removes vegetation and offers high extraction rates.
Description:
Voice over IP (VoIP) technologies such as Skype are becoming increasingly popular and widely used in different organisations, and therefore identifying the usage of this service at the network level becomes very important. Reasons for this include applying Quality of Service (QoS), network planning, prohibiting its use in some networks and lawful interception of communications. Researchers have addressed VoIP traffic classification from different viewpoints, such as classifier accuracy, building time, classification time and online classification. This previous research tested their models using the same version of a VoIP product they used for training the model, giving generalizability only to that version of the product. This means that as new VoIP versions are released, these classifiers become obsolete. In this paper, we address if this approach is applicable to detecting new, untrained, versions of Skype. We suggest that using cost-sensitive classifiers can help to improve the accuracy of detecting untrained versions, by testing compared to other algorithms. Our experiment demonstrates promising preliminary results to detect Skype version 4, by building a cost sensitive classifier on Skype version 3, achieving an F-measure score of 0.57. This is a drastic improvement from not using cost sensitivity, which scores an F-measure of 0. This approach may be enhanced to improve the detection results and extended to improve detection for other applications that change protocols from version to version.
Description:
For many applications, simultaneous sensing of a number of parameters is crucial that leads to the deployment of multiple classes of sensors having different initial energy, data generation rate and deployment density within the vicinity of a cluster as opposed to identical sensors assumed in the existing heterogeneous sensor networks. For data transmission to cluster head, such networks use single hop, multi hop and their hybrid as intra-cluster transmission policy which suffer highly from non-uniform energy usage among sensors, thereby reducing the lifetime drastically leaving considerable amount of energy in many nodes. In this paper, we propose a framework for multi-class heterogeneous sensor networks where incoming traffic is relayed towards cluster head in collaboration among multiple classes of sensors considering their heterogeneity. We also propose two transmission policies for this framework considering generic polygonal cluster and limited transmission range for individual sensors. Performance analysis shows substantial improvement of overall lifetime by the collaborative framework of multi-class sensors. Our proposed transmission policies further improve the lifetime over existing multi hop and hybrid communications through better distribution of energy usage among sensors.kam
Description:
The wireless networked sensors embedded with everyday objects will become an integral part of Future Internet, where the interaction among people, computer and those objects will shift the current Internet to a new paradigm, namely the Internet of Things. The terabyte torrent of data generated by billions of sensors belonging to a large number of distributed heterogeneous sensor networks in Future Internet will only be valuable if they can be effectively used on purpose, which leads to the necessity of an Internet scale query processing framework. In this paper, firstly, we focus on the distinct challenges present in Internet scale query processing over distributed sensor networks. Then, we propose a flexible and scalable system architecture capable of handling the complex scenario that might arise from the integration of a large number of such networks in Future Internet. Finally, we discuss the overall query processing methodology over such system and present some directions on the possible solutions to a number of identified research challenges. The outcome of this paper would foster the sensor network research in Future Internet domain
Description:
Visiting Friends and Relatives (VFR) travellers is a substantial segment of tourism in many destinations around the world. However, relative to its size, research has been lacking; commencing only around twenty years ago, and gaining momentum only this century. Research into VFR traveller profiles and characteristics has been limited, and some of what has been done conflicts with other findings. One such component, which is important for destinations, is length of stay. Whilst some of the research has indicated that VFR travel is associated with long length of stay, other research indicates that it is more linked with shortbreak tourism. This research has considered this concept, for VFR travellers compared with non-VFR travellers at three contrasting destinations in Australia. Based on quantitative research using probability sampling, VFR travellers were compared to non-VFR travellers at the popular tourism destination, Sunshine Coast (south-eastern Queensland); the northern Queensland destination of Townsville; and the inland Victorian destination of Ballarat. Whilst the average length of stay varied between all three destinations, relative to non-VFR travellers, there was no significant difference between VFR and non-VFR travellers. Therefore, VFR travel was not found to be associated with either short or long stay at the three destinations considered. However, length of stay was greater, the more popular the destination is with tourists. As such, VFR travellers stay at more attractive destinations longer than at less attractive destinations, but not at any significantly different level to non- VFRs
Description:
Visiting Friends and Relatives (VFR) travellers is a substantial segment of tourism in many destinations around the world. However, relative to its size, research has been lacking; commencing only around twenty years ago, and gaining momentum only this century. Research into VFR traveller profiles and characteristics has been limited, and some of what has been done conflicts with other findings. One such component, which is important for destinations, is length of stay. Whilst some of the research has indicated that VFR travel is associated with long length of stay, other research indicates that it is more linked with shortbreak tourism. This research has considered this concept, for VFR travellers compared with non-VFR travellers at three contrasting destinations in Australia. Based on quantitative research using probability sampling, VFR travellers were compared to non-VFR travellers at the popular tourism destination, Sunshine Coast (south-eastern Queensland); the northern Queensland destination of Townsville; and the inland Victorian destination of Ballarat. Whilst the average length of stay varied between all three destinations, relative to non-VFR travellers, there was no significant difference between VFR and non-VFR travellers. Therefore, VFR travel was not found to be associated with either short or long stay at the three destinations considered. However, length of stay was greater, the more popular the destination is with tourists. As such, VFR travellers stay at more attractive destinations longer than at less attractive destinations, but not at any significantly different level to non- VFRs
Description:
The purpose of this research paper is to present three VFR models, the VFR trilogy, to enable implementation of materials into the syllabus for tourism units at universities. Despite VFR travel representing around half of Australia’s domestic travel market, VFR fails to be given much more than a cursory mention in core tourism teaching textbooks, and does not even make it to the index of other tourism textbooks. The failure of VFR travel to be discussed in tourism textbooks, results in VFR being overlooked in the teaching syllabus, since teaching often revolves around the textbooks. Future tourism marketers and future tourism managers therefore graduate with their tourism degrees, with a complete disregard for the potential of VFR travel as a marketing segment for the business that they will end up working within. Having developed three VFR models that assist in developing an understanding of VFR travel, the purpose of this paper is to assist in developing a better understanding of this tourism phenomenon, and provide the mechanism for which current and future teaching in tourism can include coverage of VFR travel.
Description:
Visiting friends and relatives (VFR) travel is a substantial form of tourism worldwide. In Australia, official data measure VFR in one of two ways: purpose of visit or accommodation. This is only a measurement of those factors, yet tourism practitioners often mistakenly use these data to state the size of VFR travel in their destination. Based on quantitative research undertaken in three contrasting destinations in Australia, estimates for the size of VFR travel in those destinations is provided. These results highlight that using official dala for measuring VFR travel will underestimate this segment in any Australian destination. Using the VFR definitional model as a conceptual model, this research has estimated that VFR travel represents 48 percent of Australia's total overnight tourism market.
Description:
Visiting friends and relatives (VFR) travel is a large and important form of tourism in most developed countries. In Australia, VFR travel accounts for 48% of all tourism. Recent research has provided valuable insights into the length of stay, origins, mode of travel, and expenditures of VFR travellers. However, less attention has been devoted to their demographic attributes. To date, no research has compared the demographic attributes of all VFR travellers with those applicable to Non-VFRs. Based on a sample of 81,579 that covers the period 2010-2012, the present research demonstrates that the demographic profiles of VFRs and Non-VFRs in Australia are markedly different. It was found that a higher proportion of Non-VFRs were working full-time, living in capital cities and earning higher levels of household income. In contrast, a higher proportion of VFRs were working part-time, studying, or undertaking home duties. They were also significantly more likely to be pensioners or unemployed, part of a smaller household and earning a lower household income. They were more likely to be older and living alone. It is notable that socioeconomically disadvantaged groups have been acknowledged in the literature as being less engaged in tourism. However the present research provides evidence of their active participation in VFR travel. It is concluded that the provision of VFR travel opportunities may offer those who are not in a position to engage in other forms of tourism with prospective tourism related experiences.
Description:
Visiting Friends and Relatives (VFR) travel has been highlighted through previous research as being historically ignored and underestimated by both researchers and tourism marketing practitioners. However, a new wave of research may be encouraging an awakening in industry circles as to the economic, social and political benefits. Through three case studies in Victoria, Australia of successful VFR marketing campaigns, the reasons why practitioners have developed such marketing campaigns dedicated to reach and optimise their VFR travel ‘market’ are discussed. In addition, the rationale for such campaigns, and their associated marketing activities along with the measures used to judge their effectiveness are explored. The conclusions outline the common themes and issues from the three case studies, and in particular highlight the need for the campaigns to provide economic, social and political benefits.
Description:
In terms of visitor numbers, VFR is a large form of travel. Whilst VFR is well-known by tourism academics and practitioners, little is known about this form of travel. Research is relatively new, commencing in 1990; and few researchers have taken much interest in the topic. Only one study has attempted to measure the size of VFR, which developed a national size model based on extrapolating primary research undertaken in contrasting destinations to a national level. That study estimated that VFR represented 48% of Australia’s domestic visitor market. The aim of this research was to ascertain the size of VFR and reveal key profiles and characteristics using a large dataset, derived from Tourism Research Australia’s (TRA) National Visitors’ Survey (NVS) data (2010-2013). Analysis of those data (n=111,566) revealed VFR represents 48.3% of Australia’s domestic overnight visitor market, who stay the same length of time as non-VFRs but spend significantly less.
Description:
Whilst destination marketing organisations around the world invest many resources into tourism marketing, little focus is placed on Visiting Friends and Relatives (VFR) travel. A primary reason for this has been linked to the assumed lack of benefits to commercial accommodation operators. However, not all VFR travelers stay with the friends or relatives that they travel to see. This research aims to contribute to the small body of literature that has considered the behaviours of those VFR travellers who select commercial accommodation. Focusing on the Swiss market as a typical mature travel market, this research has found several key differences between VFR travelers who stay with their friends or relatives and those who choose commercial accommodation. A key finding has been a significant difference in length of stay, whereby VFRs staying in commercial accommodation enjoy longer periods of stay in the region. Those VFRs also travel greater distances.
Description:
The Family Life Cycle (FLC) model is frequently used for understanding travel patterns and consumer behaviour. The model outlines the stages many people are considered to transition through from singles, to couples, to having children, retiring and then being a solitary survivor. The aim of this research was to consider the relationship between life cycle stages and travel engagement in Australia. In particular, this research aimed to determine whether there were any differences in travel behaviour between Visiting Friends and Relatives (VFR) travellers and non- VFRs across the FLC stages. Based on a sample size of 102,029 domestic visitors, an analysis revealed that VFRs and non-VFRs were significantly different in their FLC composition ( =6851.60, df=20, p<.05). Z tests of column proportions revealed differences across a number of the groups, with the strongest level of association identified for the older non-working single FLC stage (c = .14). This paper adds to the literature undertaken in the fields of family tourism and VFR travel with a focus on life cycle stages.
Description:
The first tourism Honours degree in Australia was offered just over two decades ago, and since then Honours has become a well-recognised and important offering, particularly in terms of its role as a research pathway. The research intensive nature of Honours degrees produces graduates who are able to plan and execute project work, research and scholarship with some independence. These skills are highly sought after by some prospective employers. However, Honours programs tend to be ‗boutique‘ offerings and are particularly vulnerable to curriculum rationalisation efforts. The purpose of this research was to explore the value of Australian business Honours degrees by examining the perceptions of tourism educators. A survey of 100 academics from 19 Australian institutions revealed that Honours is highly valued and considered to be superior as a research training degree in comparison to Masters coursework and Masters by Research.
Description:
The film industry plays an important cultural and economic role in Australia. Feature film production in Australia is undergoing significant change with established filmmaking structures becoming less viable. From a tourism perspective, films can play an important role to host destinations, with promotion around a film resulting in interest from tourists to absorb themselves in the location in which a film was shot. Research into film tourism has increased in the past two decades but has focused on major box-office films. This paper adopts a case study approach to assess the benefits associated with a micro-budget feature film in Australia. This paper contributes to the growing literature in film tourism, and also offers useful insights to Destination Marketing Organisations and Councils in Australia. Of note, a successful micro-budget model could underpin a reconstruction of Australia‘s film industry and assist a generation of young filmmakers with extraordinary collaborative orientation to transform a neglected area of opportunity into an active and vibrant film category.