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We propose a novel failure-aware reactive UAV delivery service composition framework. A skyway network infrastructure is presented for the effective provisioning of services in urban areas. We present a formal drone delivery service model and a system architecture for reactive drone delivery services. We develop radius-based, cell density-based, and two-phased algorithms to reduce the search space and perform reactive service compositions when a service failure occurs. We conduct a set of experiments with a real drone dataset to demonstrate the effectiveness of our proposed approach., Comment: 14 pages, 18 figures. This is an accepted paper and it is going to appear in IEEE Transactions on Intelligent Transportation Systems (T-ITS)

We propose a 3D simulator tailored for the Drone-as-a-Service framework. The simulator enables employing dynamic algorithms for addressing realistic delivery scenarios. We present the simulator's architectural design and its use of an energy consumption model for drone deliveries. We introduce two primary operational modes within the simulator: the edit mode and the runtime mode. Beyond its simulation capabilities, our simulator serves as a valuable data collection resource, facilitating the creation of datasets through simulated scenarios. Our simulator empowers researchers by providing an intuitive platform to visualize and interact with delivery environments. Moreover, it enables rigorous algorithm testing in a safe simulation setting, thus obviating the need for real-world drone deployments. Demo: https://youtu.be/HOLfo1JiFJ0, Comment: 8 pages, 4 figures. This is an accepted demo paper and it will appear in the International Conference on Service-Oriented Computing (ICSOC 2023)

We propose a novel failure-sentient framework for swarm-based drone delivery services. The framework ensures that those drones that experience a noticeable degradation in their performance (called soft failure) and which are part of a swarm, do not disrupt the successful delivery of packages to a consumer. The framework composes a weighted continual federated learning prediction module to accurately predict the time of failures of individual drones and uptime after failures. These predictions are used to determine the severity of failures at both the drone and swarm levels. We propose a speed-based heuristic algorithm with lookahead optimization to generate an optimal set of services considering failures. Experimental results on real datasets prove the efficiency of our proposed approach in terms of prediction accuracy, delivery times, and execution times., Comment: 11 pages, 14 figures, This paper is accepted in the 2023 IEEE International Conference on Web Services (ICWS 2023)

We propose a novel context-aware drone delivery framework for optimizing package delivery through skyway networks in smart cities. We reformulate the problem of finding an optimal drone service delivery pathway as a more congruent and elegant drone delivery service composition problem. In this respect, we propose a novel line-of-sight heuristic-based context-aware composition algorithm that selects and composes near-optimal drone delivery services. We conducted an extensive experiment using a real dataset to show the robustness of our proposed approach., Comment: 8 pages, 3 figures. This is an accepted paper and it is going to appear in IEEE Internet Computing magazine

We present a demonstration of service-based trajectory planning for a drone delivery system in a multi-drone skyway network. We conduct several experiments using Crazyflie drones to collect the drone's position data, wind speed and direction, and wind effects on voltage consumption rates. The experiments are run for a varying number of recharging stations, wind speed, and wind direction in a multi-drone skyway network. Demo: https://youtu.be/zEwqdtEmmiw, Comment: 3 pages, 5 figures. This is an accepted demo paper and it is going to appear in the Proceedings of The 21st International Conference on Pervasive Computing and Communications (PerCom 2023)

We demonstrate formation flying for drone swarm services. A set of drones fly in four different swarm formations. A dataset is collected to study the effect of formation flying on energy consumption. We conduct a set of experiments to study the effect of wind on formation flying. We examine the forces the drones exert on each other when flying in a formation. We finally identify and classify the formations that conserve most energy under varying wind conditions. The collected dataset aims at providing researchers data to conduct further research in swarm-based drone service delivery. Demo: https://youtu.be/NnucUWhUwLs, Comment: 3 pages, 7 figures. This is an accepted demo paper and it will appear in The 21st International Conference on Pervasive Computing and Communications (PerCom 2023)

We prove the existence and establish the Lifschitz singularity of the integrated density of states for certain random Hamiltonians $H^\omega=H_0+V^\omega$ on fractal spaces of infinite diameter. The kinetic term $H_0$ is given by $\phi(-\mathcal L),$ where $\mathcal L$ is the Laplacian on the fractal and $\phi$ is a completely monotone function satisfying some mild regularity conditions. The random potential $V^\omega$ is of alloy-type., Comment: 43 pages, 1 fugure

We propose a novel framework for swarm-based drone delivery services with in-flight energy recharging. The framework aims to enhance the delivery time of multiple packages by reducing the number of stops and recharging times at intermediate stations. The proposed framework considers various intrinsic and extrinsic delivery constraints. We propose to use support drones whose sole purpose is to recharge other drones in the swarm during their flight. In this respect, we compute the optimal set of optimal support drones to minimize the probability of delivery services and recharging time at the next stations. We also use two settings to position the support drones in a flight formation for comparative purposes. Two novel energy sharing methods are proposed, namely, Priority-based and Fairness-based methods. A re-ordering method of the delivery drones is presented to facilitate the in-flight energy composition process. An enhanced A* algorithm is implemented to compose the optimal services in terms of delivery time. Experimental results prove the efficiency of our proposed approach., Comment: 15 pages, 12 figures. This is an accepted paper appearing in the IEEE Transactions on Services Computing (IEEE TSC)

Current drone delivery solutions mainly focus on single package delivery using one drone. However, the recent developments in drone technology enable a drone to deliver multiple packages in a single trip. We use the nearest destination first strategy for the faster delivery of packages in a skyway network. This demonstration is a proof-of-concept prototype for the multi-package delivery in urban airspace following a skyway network. We deploy and test this multi-package drone delivery in an indoor testbed environment using a 3D model of Sydney CBD. Demo: https://youtu.be/YTwsIfUvWPc, Comment: 4 pages, 3 figures. This is an accepted demo paper and it is going to appear in the Proceedings of 2022 ACM International Joint Conference on Pervasive and Ubiquitous Computing (UbiComp22)

We propose a novel framework for the recommendation of swarm-based drone delivery services based on the consumers preferences. We propose a density-based pruning approach that uses the concept of partnerships with charging station providers to reduce the search space of swarm-based drone service delivery providers. A weighted service composition algorithm is proposed that considers the providers capabilities and consumers' preferences in selecting the best next service. We propose a voting-based recommendation algorithm to select the best providers. We conduct a set of experiments to evaluate the efficiency of the framework in terms of consumer satisfaction, run-time, and search space reduction cost., Comment: 10 pages, 9 figures. This is an accepted paper and it is going to appear in the Proceedings of the 2022 IEEE International Conference on Web Services (ICWS 2022)

Drone swarms are required for the simultaneous delivery of multiple packages. We demonstrate a multi-stop drone swarm-based delivery in a smart city. We leverage formation flying to conserve energy and increase the flight range of a drone swarm. An adaptive formation is presented in which a swarm adjusts to extrinsic constraints and changes the formation pattern in-flight. We utilize the existing building rooftops in a city and build a line-of-sight skyway network to safely operate the swarms. We use a heuristic-based A* algorithm to route a drone swarm in a skyway network., Comment: 3 pages, 6 figures. This is an accepted paper and it is going to appear in the Proceedings of the 20th International Conference on Pervasive Computing and Communications (PerCom 2022)

Service delivery is set to experience a major paradigm shift with fast advances in drone technologies coupled with higher expectations from customers and increased competition. We propose a novel service-oriented approach to enable the ubiquitous delivery of packages in a drone-operated skyway network. We discuss the benefits, framework and architecture, contemporary approaches, open challenges and future visioned directions of service-based drone deliveries., Comment: 9 pages, 7 figures. This is an accepted paper and it is going to appear in the Proceedings of the 2021 IEEE International Conference on Collaboration and Internet Computing (CIC 2021)

Drones are becoming a novel means for delivery services. We present a demonstration of drone delivery services in a skyway network that uses the service paradigm. A set of experiments is conducted using Crazyflie drones to collect the data on various positions of drones, wind speed, wind direction, and battery consumption. We run the experiments for a range of flight patterns including linear, rectangular, and triangular shapes., Comment: 4 pages, 13 figures. This is an accepted paper and it is going to be published in the Proceedings of 19th International Conference on Service Oriented Computing (ICSOC 2021)

We propose a novel framework for the re-allocation of drone swarms for delivery services known as Swarm-based Drone-as-a-Service (SDaaS). The re-allocation framework ensures maximum profit to drone swarm providers while meeting the time requirement of service consumers. The constraints in the delivery environment (e.g., limited recharging pads) are taken into consideration. We utilize reinforcement learning (RL) to select the best allocation and scheduling of drone swarms given a set of requests from multiple consumers. We conduct a set of experiments to evaluate and compare the efficiency of the proposed approach considering the provider's profit and run-time efficiency., Comment: 8 pages, 2 figures, accepted and to be published in the proceedings of 19th International Conference on Service Oriented Computing (ICSOC 2021)

Current drone delivery systems mostly focus on point-to-point package delivery. We present a multi-stop drone service system to deliver packages anywhere anytime within a specified geographic area. We define a skyway network which takes into account flying regulations, including restricted areas and no-fly zones. The skyway nodes typically represent building rooftops which may act as both recharging stations and delivery destinations. A heuristic-based A* algorithm is used to compute an optimal path from source to destination taking into account a number of constraints, including delivery time, availability of recharging stations, etc. We deploy our drone delivery system in an indoor testbed environment using a 3D model of Sydney CBD. We describe a graphical user interface to monitor the real-time package delivery in the skyway network., Comment: 2 pages, 5 figures. This is an accepted demo paper and it is going to appear in the Proceedings of 2021 ACM International Joint Conference on Pervasive and Ubiquitous Computing (UbiComp21)

We propose a novel framework for the allocation of drone swarms for delivery services known as Swarm-based Drone-as-a-Service (SDaaS). The allocation framework ensures minimum cost (aka maximum profit) to drone swarm providers while meeting the time requirement of service consumers. The constraints in the delivery environment (e.g., limited recharging pads) are taken into consideration. We propose three algorithms to select the best allocation of drone swarms given a set of requests from multiple consumers. We conduct a set of experiments to evaluate and compare the efficiency of these algorithms considering the provider's profit, feasibility, requests fulfilment, and drones utilization level., Comment: 10 pages, 11 figures. This is an accepted paper and it is going to appear in the Proceedings of the 2021 IEEE International Conference on Web Services (ICWS 2021)

In this paper we prove matching upper and lower bounds for the transition density function of the subordinate reflected Brownian motion on fractals.

Swarm of drones are increasingly being asked to carry out missions that can't be completed by one drone. Particularly, in delivery, issues arise due to the swarm's limited flight endurance. Hence, we propose a novel formation-guided framework for selecting Swarm-based Drone-as-a-Service (SDaaS) for delivery. A detailed study is carried out to highlight the effect of swarm formations on energy consumption. Two SDaaS selection approaches, i.e. Fixed and Adaptive, are designed considering the different formation decisions a swarm can take. The proposed framework considers extrinsic constraints including wind speed and direction. We propose SDaaS selection algorithms for each approach. Experimental results prove the efficiency of the proposed algorithms., Comment: 9 pages, 10 figures. This is an accepted paper and it is going to appear in the Proceedings of the 17th EAI International Conference on Mobile and Ubiquitous Systems: Computing, Networking and Services (EAI MobiQuitous 2020)

Echocardiography is the most commonly used imaging technique in clinical cardiology. Due to the high demand for this type of examination and the small number of specialists, there is a need to support the examination process through telemedicine. Moreover, specialist training can be supported by appropriate simulation systems. For (i) creating tailor-made tele-echo robots, (ii) creating echo system simulators, and (iii) conducting echo examination with local or remote expert assistance, knowledge about echo probe kinesthetic parameters during echocardiography examination is advisable. The article describes the concept of a measuring system for obtaining such data., Comment: 7 pages, 9 figures

We propose a novel framework for composing Swarm-based Drone-as-a-Service (SDaaS) for delivery. Two composition approaches, i.e., sequential and parallel are designed considering the different behaviors of drone swarms. The proposed framework considers various constraints, e.g., recharging time and limited battery to meet delivery deadlines. We propose SDaaS composition algorithms using a modified A* algorithm. A cooperative behavior model is incorporated to reduce recharging and waiting time in a delivery. Experimental results prove the efficiency of the proposed approach., Comment: Submitted to ICWS 2020

We analyze the problem of a renewable generator who wants to sell its random generation in a two-stage market to a number of strategic, but flexible, load serving entities (LSEs). To offer an incentive to participate in the auction, the generator promises to pay a penalty associated with any shortfall in generation due to the uncertain nature of the traded resource. We devise an auction mechanism that efficiently allocates electricity among LSEs while eliciting their true valuations. We show that the consumer surplus of the LSEs and expected profit of the generator are positive, thereby creating a win-win situation for all market participants.

The ubiquity of Information and Communication Technologies (ICTs) in work settings has changed the way employees behave. ICTs such as smartphones, email and social media makes employees more connected than has ever been possible. The degree of ICT connectivity can create a positive as well as a negative impact on employees' productivity. In this context, the notion of ICT self-discipline - an individual's ability to control their behaviours towards ICTs - becomes pivotal in the process of managing ICT connectivity. This follow-on study reports the results of an online survey of 443 to New Zealand professionals regarding the influence of ICT self-discipline on the relationship between ICT connectivity and employee productivity. Findings indicated that the impact of ICT self-discipline varies depending on the organisation and industry an employee works in. Insights and recommendations for future research are shared in this paper. Findings from this study contribute to IS research and practice., Comment: ISBN# 978-0-646-95337-3 Presented at the Australasian Conference on Information Systems 2015 (arXiv:1605.01032)

The parity of the analytic rank of an elliptic curve is given by the root number in the functional equation L(E,s). Fixing an elliptic curve over any number field and considering the family of its quadratic twists, it is natural to ask what the average analytic rank in this family is. A lower bound on this number is given by the average root number. In this paper, we investigate the root number in such families and derive an asymptotic formula for the proportion of curves in the family that have even rank. Our results are then used to support a conjecture about the average analytic rank in this family of elliptic curves., Comment: 9 Pages, 1 Table

In this paper, we examine Kitaev's lattice model for an arbitrary complex, semisimple Hopf algebra. We prove that this model gives the same topological invariants as Turaev-Viro theory. Using the description of Turaev-Viro theory as an extended TQFT, we prove that the excited states of the Kitaev model correspond to Turaev-Viro theory on a surface with boundary., Comment: LaTex2e with TikZ pictures; 29 pages

In the third paper in this series, we examine the Reshetikhin-Turaev and Turaev-Viro TQFTs at the level of surfaces. In particular, we show that for a closed surface $\Sigma$, $Z_{TV, \mathcal{C}}(\Sigma) \cong Z_{RT, Z(\C)}(\Sigma)$, thus extending the equality of 3-manifold invariants proved in an earlier paper to an equivalence of TQFTs. We also describe how to compute Turaev-Viro state sums for 3-manifolds with embedded ribbon graphs., Comment: 19 pages, many figures. Added explanation of equivalence of theories for extended 3-manifolds and added description of TV theory for manifolds with embedded ribbon graphs

In this paper we show how one can extend Turaev-Viro invariants, defined for an arbitrary spherical fusion category $C$, to 3-manifolds with corners. We demonstrate that this gives an extended TQFT which conjecturally coincides with the Reshetikhin-Turaev TQFT corresponding to the Drinfeld center $Z(C)$. In the present paper we give a partial proof of this statement., Comment: 38 pages, many figures. New in v.3: significantly rewritten exposition, providing details of some proofs which were only outlined in the previous version

Investigates the relationship between lesbian internalized homophobia and various psychosocial variables in a national sample of 157 women. Discusses development of the Lesbian Internalized Homophobia Scale and provides evidence in support of its reliability and construct validity. Highlights the importance of addressing internalized homophobia when one is working with lesbians in therapy. (Contains 50 references and 3 tables.) (GCP)

The major problem area of humanization and involvement in the New York City high schools is the focus of this report. In this area a most promising trend is the emergence of the school-within-a-school and the small-unit school. This report surveys the various units which have been established, their roles in the high school system, and some of the problems and issues they raise. The report does not provide an evaluation of the schools and programs. As a secondary point of interest, the extent to which the recommendations suggested in the publication entitled Toward the Twenty-First Century have been implemented and even surpassed are noted. In addition to the introductory section, two other sections address the small-unit programs in alternative education and small-unit organization within the high school mainstream. The former focuses on various aspects of adjunct minischools and independent alternative high schools. The latter focuses on the following areas: a complex of minischools, schools-within-a-school, educational options organized on a citywide basis, and the high school as a synthesis of small units. It is apparent from the report that t he one constant in the 98 schools is experimentation for constructive change. It is likely that no school or program is exactly the same in two consecutive years. (Author/AM)