Decentralized Orchestration of Open Services- Achieving High Scalability and Reliability with Continuation-Passing Messaging

The papers of this thesis are not available in Munin. Paper I: Yu, W.,Haque, A. A. M. “Decentralised web- services orchestration with continuation-passing messaging”. Available in International Journal of Web and Grid Services 2011, 7(3):304–330. Paper II: Haque, A. A. M., Yu, W.: “Peer-to-peer orchestration of web mashups”. Available in International Journal of Adaptive, Resilient and Autonomic Systems 2014, 5(3):40-60. Paper V: Haque, A. A. M., Yu, W.: “Decentralized and reliable orchestration of open services”. In:Service Computation 2014. International Academy, Research and Industry Association (IARIA) 2014 ISBN 978-1-61208-337-7.An ever-increasing number of web applications are providing open services to a wide range of applications. Whilst traditional centralized approaches to services orchestration are successful for enterprise service-oriented systems, they are subject to serious limitations for orchestrating the wider range of open services. Dealing with these limitations calls for decentralized approaches. However, decentralized approaches are themselves faced with a number of challenges, including the possibility of loss of dynamic run-time states that are spread over the distributed environment. This thesis presents a fully decentralized approach to orchestration of open services. Our flow-aware dynamic replication scheme supports both exceptional handling, failure of orchestration agents and recovers from fail situations. During execution, open services are conducted by a network of orchestration agents which collectively orchestrate open services using continuation-passing messaging. Our performance study showed that decentralized orchestration improves the scalability and enhances the reliability of open services. Our orchestration approach has a clear performance advantage over traditional centralized orchestration as well as over the current practice of web mashups where application servers themselves conduct the execution of the composition of open web services. Finally, in our empirical study we presented the overhead of the replication approach for services orchestration

Elastic Business Process Management: State of the Art and Open Challenges for BPM in the Cloud

With the advent of cloud computing, organizations are nowadays able to react rapidly to changing demands for computational resources. Not only individual applications can be hosted on virtual cloud infrastructures, but also complete business processes. This allows the realization of so-called elastic processes, i.e., processes which are carried out using elastic cloud resources. Despite the manifold benefits of elastic processes, there is still a lack of solutions supporting them. In this paper, we identify the state of the art of elastic Business Process Management with a focus on infrastructural challenges. We conceptualize an architecture for an elastic Business Process Management System and discuss existing work on scheduling, resource allocation, monitoring, decentralized coordination, and state management for elastic processes. Furthermore, we present two representative elastic Business Process Management Systems which are intended to counter these challenges. Based on our findings, we identify open issues and outline possible research directions for the realization of elastic processes and elastic Business Process Management.Comment: Please cite as: S. Schulte, C. Janiesch, S. Venugopal, I. Weber, and P. Hoenisch (2015). Elastic Business Process Management: State of the Art and Open Challenges for BPM in the Cloud. Future Generation Computer Systems, Volume NN, Number N, NN-NN., http://dx.doi.org/10.1016/j.future.2014.09.00

Prilog fauni danjih leptira (Lepidoptera: Papilionoidea) planine Kozjak, Split, Hrvatska

Mt Kozjak is an elongated mountain ridge situated in central Dalmatia, just above the Riviera of Kaštela near Split. It was well surveyed a century ago by Hermann Stauder who recorded 38 butterfly species. Among these, Papilio alexanor was the most prominent discovery. During our surveys from 2007 to 2018, we recorded 82 butterfly species at 19 localities bringing the total of observed species to 87. We managed to confirm the presence of Papilio alexanor more than hundred years after the first observation in the area. The occurrence of some additional rare and interesting species like Carcharodus orientalis, Pyrgus sidae, Pyrgus serratulae, Parnassius mnemosyne, Euchloe ausonia, Cupido osiris, Polyommatus admetus and Hyponephele lycaon is discussed in more detail. The butterfly fauna of Mt Kozjak is very diverse given its geographic position, low habitat diversity and size. Abandonment of pasturing and subsequent overgrowing of calcareous grasslands is the most important factor causing long term butterfly decline on Mt Kozjak.Planina Kozjak izduženi je planinski greben smješten u središnjoj Dalmaciji, iznad Kaštela u blizini Splita. Prije jednog stoljeća to je područje dobro istražio Herman Stauder te je zabilježio 38 vrsta danjih leptira. Među njima, najistaknutiji je nalaz vrste Papilio alexanor. Tijekom našeg istraživanja koje je trajalo od 2007. do 2018. zabilježili smo 82 vrsta leptira na 19 lokaliteta, povećavajući broj poznatih vrsta na 87. Uspjeli smo potvrditi i prisutnost vrste Papilio alexanor, preko 100 godina nakon prvih opažanja na tome području. Dodatno raspravljamo o nalazima rijetkih ili zanimljivih vrsta poput Carcharodus orientalis, Pyrgus sidae, Pyrgus serratulae, Parnassius mnemosyne, Euchloe ausonia, Cupido osiris, Polyommatus admetus i Hyponephele lycaon. Fauna leptira planine Kozjak vrlo je raznolika s obzirom na svoj geografski položaj, nisku raznolikost staništa i veličinu. Napuštanje ispaše i zarastanje vapnenačkih travnjaka najvažniji su čimbenici koji uzrokuju dugoročno opadanje raznolikosti leptira na Kozjaku

Autonomous RPOD Technology Challenges for the Coming Decade

Rendezvous Proximity Operations and Docking (RPOD) technologies are important to a wide range of future space endeavors. This paper will review some of the recent and ongoing activities related to autonomous RPOD capabilities and summarize the current state of the art. Gaps are identified where future investments are necessary to successfully execute some of the missions likely to be conducted within the next ten years. A proposed RPOD technology roadmap that meets the broad needs of NASA's future missions will be outlined, and ongoing activities at OSFC in support of a future satellite servicing mission are presented. The case presented shows that an evolutionary, stair-step technology development program. including a robust campaign of coordinated ground tests and space-based system-level technology demonstration missions, will ultimately yield a multi-use main-stream autonomous RPOD capability suite with cross-cutting benefits across a wide range of future applications

Self-organizing distributed digital library supporting audio-video

The StreamOnTheFly network combines peer-to-peer networking and open-archive principles for community radio channels and TV stations in Europe. StreamOnTheFly demonstrates new methods of archive management and personalization technologies for both audio and video. It also provides a collaboration platform for community purposes that suits the flexible activity patterns of these kinds of broadcaster communities

Future Supply of Medical Radioisotopes for the UK Report 2014

The UK has no research nuclear reactors and relies on the importation of 99Mo and other medical radioisotopes (e.g. Iodine-131) from overseas (excluding PET radioisotopes). The UK is therefore vulnerable not only to global shortages, but to problems with shipping and importation of the products. In this context Professor Erika Denton UK national Clinical Director for Diagnostics requested that the British Nuclear Medicine Society lead a working group with stakeholders including representatives from the Science & Technology Facilities Council (STFC) to prepare a report. The group had a first meeting on 10 April 2013 followed by a working group meeting with presentations on 9th September 2013 where the scope of the work required to produce a report was agreed. The objectives of the report are: to describe the status of the use of medical radioisotopes in the UK; to anticipate the potential impact of shortages for the UK; to assess potential alternative avenues of medical radioisotope production for the UK market; and to explore ways of mitigating the impact of medical radioisotopes on patient care pathways. The report incorporates details of a visit to the Cyclotron Facilities at Edmonton, Alberta and at TRIUMF, Vancouver BC in Canada by members of the report team.Comment: 121 page

Enabling Recovery of Secure Non-Volatile Memories

Emerging non-volatile memories (NVMs), such as phase change memory (PCM), spin-transfer torque RAM (STT-RAM) and resistive RAM (ReRAM), have dual memory-storage characteristics and, therefore, are strong candidates to replace or augment current DRAM and secondary storage devices. The newly released Intel 3D XPoint persistent memory and Optane SSD series have shown promising features. However, when these new devices are exposed to events such as power loss, many issues arise when data recovery is expected. In this dissertation, I devised multiple schemes to enable secure data recovery for emerging NVM technologies when memory encryption is used. With the data-remanence feature of NVMs, physical attacks become easier; hence, emerging NVMs are typically paired with encryption. In particular, counter-mode encryption is commonly used due to its performance and security advantages over other schemes (e.g., electronic codebook encryption). However, enabling data recovery in power failure events requires the recovery of security metadata associated with data blocks. Naively writing security metadata updates along with data for each operation can further exacerbate the write endurance problem of NVMs as they have limited write endurance and very slow write operations. Therefore, it is necessary to enable the recovery of data and security metadata (encryption counters) but without incurring a significant number of writes. The first work of this dissertation presents an explanation of Osiris, a novel mechanism that repurposes error correcting code (ECC) co-located with data to enable recovery of encryption counters by additionally serving as a sanity-check for encryption counters used. Thus, by using a stop-loss mechanism with a limited number of trials, ECC can be used to identify which encryption counter that was used most recently to encrypt the data and, hence, allow correct decryption and recovery. The first work of this dissertation explores how different stop-loss parameters along with optimizations of Osiris can potentially reduce the number of writes. Overall, Osiris enables the recovery of encryption counters while achieving better performance and fewer writes than a conventional write-back caching scheme of encryption counters, which lacks the ability to recover encryption counters. Later, in the second work, Osiris implementation is expanded to work with different counter-mode memory encryption schemes, where we use an epoch-based approach to periodically persist updated counters. Later, when a crash occurs, we can recover counters through test-and-verification to identify the correct counter within the size of an epoch for counter recovery. Our proposed scheme, Osiris-Global, incurs minimal performance overheads and write overheads in enabling the recovery of encryption counters. In summary, the findings of the present PhD work enable the recovery of secure NVM systems and, hence, allows persistent applications to leverage the persistency features of NVMs. Meanwhile, it also minimizes the number of writes required in meeting this crash consistency requirement of secure NVM systems

La búsqueda de hielo de agua en Cometas y Asteroides

Tesis inédita de la Universidad Complutense de Madrid, Facultad de Ciencias Físicas, Departamento de Física de la Tierra y Astrofísica, leída el 12/02/2021. Tesis formato europeo (compendio de artículos)The presence of water is considered one of the key ingredients for the formation of life on Earth. Indeed, current theories as to the origin of the Earth’s oceans suggest that the water located there originated from both comets and asteroids, with the exact fractional contribution still under discussion. However, water is not unique to the Earth; it has been found hidden deep inside polar craters on the moon, as well as in its fragment OH form contained in moon regolith. It is believed to make up over two thirds of the mass of the giant icy planets Uranus and Neptune. It is prevalent in the form of ice throughout the outer solar system on the moons of planets, on Kuiper Belt Objects, and on comets. In the case of asteroids, although few detections of surface ice have been made, evidence of hydrated minerals (any mineral containing H2O or OH) abound. A search for water ice on the surface and subsurface of comets and asteroids provides not only key information as to its presence and distribution on these primitive bodies, it also contributes to giving a deeper understanding on how the solar system formed, how water was delivered to the Earth by these bodies, and indeed how life emerged as a result. This thesis has as its main goal to search for the presence of water ice on and just below the surfaces of comets and asteroids, estimating its coverage and where feasible characterising its properties. This goal is broken down into two objectives, whereby we search for and characterise ice found on cometary (1st objective) and asteroid (2nd objective) surfaces and subsurfaces. In this thesis, we present a number of publications aiming to address these objectives...La presencia de agua se considera uno de los ingredientes clave para la formación de vida en la Tierra. De hecho, las teorías actuales sobre el origen de los océanos de la Tierra sugieren que el agua que se encuentra allí se originó tanto en cometas como en asteroides, con la contribución fraccionaria exacta aún en discusión. Sin embargo, el agua no es exclusiva de la Tierra; se ha encontrado escondido en el interior de los cráteres polares de la luna, así como en su forma de fragmento OH contenido en su regolito. Se cree que constituye más de dos tercios de la masa de los planetas helados gigantes Urano y Neptuno. Prevalece en forma de hielo en todo el sistema solar exterior en las lunas de los planetas, en los objetos del cinturón de Kuiper y en los cometas. En el caso de los asteroides, aunque se han realizado pocas detecciones de hielo en la superficie, abunda la evidencia de minerales hidratados (cualquier mineral que contenga H2O u OH). La búsqueda de hielo de agua en la superficie y el sub-superficie de cometas y asteroides proporciona no solo información clave sobre su presencia y distribución en estos cuerpos primitivos, sino que también contribuye a brindar una comprensión más profunda de cómo se formó el sistema solar, cómo se entregó el agua a la Tierra por estos cuerpos y, de hecho, cómo surgió la vida como resultado. Esta tesis tiene como objetivo principal buscar la presencia de hielo de agua sobre y justo debajo de las superficies de cometas y asteroides, estimando su cobertura y, cuando sea posible, caracterizando sus propiedades. Este objetivo principal se divide en dos objetivos específicos, mediante los cuales buscamos y caracterizamos el hielo que se encuentra en los superficies y sub-superficies de cometas (primer objetivo) y asteroides (segundo objetivo). En esta tesis presentamos una serie de publicaciones destinadas a abordar estos objetivos...Fac. de Ciencias FísicasTRUEunpu