A generic architecture for spatial crowdsourcing

The popularity of mobile Internet techniques and Online-To-Offline(O2O) business models has led to the emergence of various spatial crowdsourcing (SC) platforms in our daily life. A core issue of SC platforms is to assign tasks to suitable crowd workers. Existing approaches usually focus on the matching of two types of objects,tasks and workers, and let workers to travel to the location of usersto provide services, which is a 2D matching problem. However, recent services provided by some new platforms, such as person-alized haircut service1and station ride-sharing, need users andworkers travel together to a third workplace to complete the service, which is indeed a 3D matching problem. Approaches in the existingstudies either cannot solve such 3D matching problem, or lack aassignment plan satisfying both users' and workers' preference inreal applications. Thus, in this paper, we propose a 3-Dimensional Stable Spatial Matching(3D-SSM) for the 3D matching problem innew SC services. We prove that the 3D-SSM problem is NP-hard, and propose two baseline algorithms and two efficient approximatealgorithms with bounded approximate ratios to solve it. Finally, weconduct extensive experiment studies which verify the efficiencyand effectiveness of the proposed algorithms on real and synthetic datasets.

The ubiquity of mobile internet has led to the success of Spatial Crowdsourcing platforms like real-time taxi-hailing services, online food ordering services, etc. A critical component of such services is the task assignment algorithm employed for assigning the tasks to the workers of the platform. Our study of the literature in this domain shows that most of the task assignment algorithms developed for spatial crowdsourcing platforms address the problem from a utilitarian perspective, i.e., they optimise for only kind of entity. In contrast, we address the task assignment problem in spatial crowdsourcing platforms from an egalitarian perspective. An egalitarian approach aims to optimise the expectation of all entities involved. Specifically, we aim to minimise the waiting time for the customers and workers, while maximising the profit earned by the platform. To the best of our knowledge, ours is the only study that achieves this objective in a fully-online setting, with deadlines for both customers and workers. We propose two heuristic algorithms to solve the problem, and evaluate our algorithms on a real taxi-trips records dataset. Our algorithms exhibit a superior performance than the state-of-the-art algorithm for the fully-online bottleneck matching problem with deadlines, in terms of solution quality, running time and response time.

With the popularity of mobile devices and Online To Offline (O2O) marketing model, various spatial crowdsourcing platforms, such as Gigwalk, WeGoLook, TaskRabbit and gMission, are getting popular. An important task of spatial crowdsourcing platforms is to allocate spatial tasks to suitable workers. Existing approaches only simply focus on maximizing the number of completed spatial tasks but neglect the influence of supplies and demands from real crowdsourcing market, which leads to different optimal objectives for crowdsourcing task assignments. In this paper, to address the shortcomings of the existing approaches, we first propose a more general spatial crowdsourcing task assignment problem, called Market-driven Optimal Task Assignment (MOTA) problem, consisting of two real scenarios, Excess Demand of Crowd Workers and Insufficient Supply of Spatial Tasks, in daily life. Unfortunately, we prove that the two variants of this problem are NP-Hard. Thus, we design two approximation algorithm to solve this problem. Finally, we verify the effectiveness and efficiency of the proposed methods through extensive experiments on synthetic datasets.

An Overview of Location Privacy Protection in Spatial Crowdsourcing Platforms During the Task Assignment Process

Emerging spatial crowdsourcing platforms enable the workers (i.e., crowd) to complete spatial crowdsourcing tasks (like taking photos, conducting citizen journalism) that are associated with rewards and tagged with both time and location features. In this paper, we study the problem of online recommending an optimal route for a crowdsourcing worker, such that he can (i) reach his destination on time and (ii) receive the maximum reward from tasks along the route. We show that no optimal online algorithm exists in this problem. Therefore, we propose several heuristics, and powerful pruning rules to speed up our methods. Experimental results on real datasets show that our proposed heuristics are very efficient, and return routes that contain 82–91 % of the optimal reward.

Recently, there are several studies focusing on the bottleneck optimization objective in Spatial Crowdsourcing (SC). However, these studies usually do not consider the deadline constraint. Different from these studies, we take deadlines into consideration and identify the Fully Online Bottleneck Matching with Deadlines (FOBMD) problem in SC. Because of the deadlines, consideration must be given to both the bottleneck cost and the cardinality, which makes the FOBMD problem more challenging, and no online algorithm without actively refusing tasks can achieve a constant competitive ratio of the bottleneck cost for the FOBMD problem. To settle the FOBMD problem, we consider three baseline algorithms and propose an online algorithm, namely Local Isolated Point Greedy (LIPG). Finally, we validate the effectiveness and efficiency of our proposed algorithm via extensive experiments on both synthetic and real world datasets.

Spatial crowd sourcing uses workers for performing tasks that require travel to different locations in the physical world. This paper considers the online spatial task assignment problem. In this problem, spatial tasks arrive in an online manner and an appropriate worker must be assigned to each task. However, outcome of an assignment is stochastic since the worker can choose to accept or reject the task. Primary goal of the assignment algorithm is to maximize the number of successful assignments over all tasks. This presents an exploration-exploitation challenge, the algorithm must learn the task acceptance behavior of workers while selecting the best worker based on the previous learning. We address this challenge by defining a framework for online spatial task assignment based on the multi-armed bandit formalization of the problem. Furthermore, we adapt a contextual bandit algorithm to assign a worker based on the spatial features of tasks and workers. The algorithm simultaneously adapts the worker assignment strategy based on the observed task acceptance behavior of workers. Finally, we present an evaluation methodology based on a real world dataset, and evaluate the performance of the proposed algorithm against the baseline algorithms. The results demonstrate that the proposed algorithm performs better in terms of the number of successful assignments.

This paper provides the vision of a unified spatial crowdsourcing platform that is designed to efficiently tackle different types of spatial tasks which have been gaining a lot of popularity in recent years. Several examples of spatial tasks are ride-sharing services, delivery services, translation tasks, and crowd-sensing tasks. While existing crowdsourcing platforms, such as Amazon Mechanical Turk and Upwork, are widely used to solve lots of general tasks, e.g., image labeling; using these marketplaces to solve spatial tasks results in low quality results. This paper identifies a set of characteristics for a unified spatial crowdsourcing environment and provides the core components of the platform that are required to empower the capability in solving different types of spatial tasks.

Pressure from the vinyl chloride (VC) industry on researchers involved in industry-sponsored studies and on regulatory agencies has been documented since 1970s. This commentary describes the influence of a lawsuit pursued by workers of an Italian VC plant on the recent scientific debate on VC exposure and risk of hepatocellular carcinoma (HCC). Original studies carried out by consultants of the public prosecutors and by independent researchers supported the above association. VC-industry consultants published two reviews during the lawsuit, claiming that liver angiosarcoma was the only VC-related cancer. The judges concluded that the evidence of the association between HCC and VC was still not convincing. After the trial, the risk of HCC was confirmed by a re-assessment of VC carcinogenicity from the International Agency for Research on Cancer, but other subsequent industry-funded reviews criticized the new evidence. Industry-funded authors cited each other, and rarely disclosed conflicts of interest. Based on a network of collaborating researchers, industrial interests can shape the literature enhancing the background noise surrounding the scientific evidence.

Attention directed at different species by society and science is particularly relevant within the field of conservation, as societal preferences will strongly impact support for conservation initiatives and their success. Here, we assess the association between societal and research interests in four charismatic and threatened species groups, derived from a range of different online sources and social media platforms as well as scientific publications. We found a high level of concordance between scientific and societal taxonomic attention, which was consistent among assessed species groups and media sources. Results indicate that research is apparently not as disconnected from the interests of society as it is often reproached, and that societal support for current research objectives should be adequate. While the high degree of similarity between scientific and societal interest is both striking and satisfying, the dissimilarities are also interesting, as new scientific findings may constitute a constant source of novel interest for the society. In that respect, additional efforts will be necessary to draw scientific and societal focus towards less charismatic species that are in urgent need of research and conservation attention.

Telecommunications engineering has witnessed tremendous advances in recent years primarily due to progress in network science and engineering and developments in related areas and applications. the business and economic aspects of telecommunications engineering have attracted the scientific interest of academia and industry as another ingredient of telecom, aiming to respond to the economic aspects of telecommunications networks developments. Therefore, the emerging telecom environment assembles people working in science, engineering, economics, business and social sciences, considering telecom developments and challenges. These needs have been accompanied by the development of specialized undergraduate courses world-widely. The development of a curriculum in telecommunications engineering economics as a joint effort of Informatics and Telecommunications and Economics faculties of the National and Kapodistrian University of Athens is hereafter discussed and the 15-years experiences are presented.

To meet future demands, mineral resources found in deposits along mid-ocean ridges have triggered the interest of the deep-sea mining industry. Comprehensive environmental management regulations are being developed by the International Seabed Authority (ISA) to control the exploitation of seabed areas beyond national jurisdiction. Norway has recently opened its seabed to mining exploration, which may potentially lead to future commercial exploitation of seafloor massive sulfides (SMS) and manganese crusts. Large uncertainties remain about the environmental consequences of such activities and improved knowledge is required to be able to describe and evaluate the associated environmental risks. An environmental risk assessment (ERA) is the process of assessing potential harm to the environment. In this paper, we apply a framework for environmental risk assessment as a mechanism to identify priority environmental knowledge, technology, and practice needed for future SMS mining operations. The ERA framework is aligned with the key elements of the draft ISA regulations and includes how risk terms and principles are understood and used by Norwegian policymakers and authorities. Regulatory draft documents, scientific literature, expert opinions, and an assessment of environmental severity, vulnerability, and value criteria have provided informative bases for the discussed research and development (R&D) recommendations. While the risk framework and associated R&D recommendations are aimed at future mining in the areas of the Arctic Mid-Ocean Ridge (AMOR) under Norwegian jurisdiction, they are also relevant to other areas of SMS exploitation and may form a useful template.

THE British Science Guild, the annual meeting of which was held on April 29, occupies a peculiar position among kindred societies. We have societies concerned with the promotion of science in general—notably the Royal Society—and of particular sciences such as chemistry, physics, geology, botany and zoology, and their numerous progeny—physical chemistry, biochemistry, and the rest. There are other societies—the Society of Chemical Industry is a good example—which devote themselves to the application of particular sciences to industry. The British Science Guild, founded by Sir Norman Lockyer in 1905 “to promote the application of scientific methods and results to social problems and public affairs,” is not a scientific society, nor an institute of industry, nor an educational association. It is a national organisation, the chief purpose of which is to reconcile the interests of science industry, and education, and to co-ordinate their activities. Sir William Bragg, in a recent broadcast talk explaining the work of the Guild, said: “In originality of scientific work, mechanical ingenuity and operative skill, our race is in the forefront.” This claim will be confirmed by the most cursory inspection of our national roll of men of science and invention. But there is something lacking, he suggests, and that is “a spirit of unity among all classes through the alliance of science, invention and labour working as a single force for national development and common welfare.” To this “spirit of unity” the nation, beset by its war-heritage of financial and industrial problems, will have to pay increasing homage if it is to maintain its leading position, achieved in large measure through its “scientific work, mechanical ingenuity, and operative skill.”

Over the past two decades, both academic and industrial interest in olive bioactive compounds has grown significantly due to their remarkable health benefits, such as antioxidant, anti-inflammatory, and cardioprotective properties. These compounds, found in both olive fruit and leaves, have become a central focus in the research on functional foods and nutraceuticals. A comprehensive bibliometric analysis of scientific publications from 2000 to 2024 highlights a notable increase in this field, with 2228 documents published in high-impact journals with an estimated annual growth rate of 0.2694 year-1, particularly in the last decade. This surge reflects the growing recognition of olive bioactive compounds' potential in promoting human health through nutritional and therapeutic interventions, and their role in the expanding nutraceutical industry. This growth is further reaffirmed by patent analysis, which shows a significant rise in industrial interest and patent filings related to olive bioactive compounds. The analysis also examined nearly 6000 keywords to identify the most influential research domains, pinpoint knowledge gaps, and reveal the most important bioactive compounds in olives and their potential in preventing various human diseases.

The demands for increasingly new spatial information application are becoming a social and economic imperative in many urban today. Urban spatial information platform is an important part of geospatial fundamental framework construction in digital city as an integrated shared environment. There requires novel technologies for urban construction, planning, even a higher level scientific support. Web services have received much interest in industry due to their potential in facilitating seamless business-to-business or enterprise application integration. So this paper focused on urban spatial information platform construction on the basis of a variety of geographic information services and data services. Spatial information service and spatial information platform are discussed, and integrated spatial information platform is proposed. An approach to achieve spatial information sharing is presented, and we also talked our related works. At last we draw our conclusion.