3,916 research outputs found
Rise of the Planet of Serverless Computing: A Systematic Review
Serverless computing is an emerging cloud computing paradigm, being adopted to develop a wide range of software applications.
It allows developers to focus on the application logic in the granularity of function, thereby freeing developers from tedious and
error-prone infrastructure management. Meanwhile, its unique characteristic poses new challenges to the development and deployment
of serverless-based applications. To tackle these challenges, enormous research efforts have been devoted. This paper provides a
comprehensive literature review to characterize the current research state of serverless computing. Specifically, this paper covers 164
papers on 17 research directions of serverless computing, including performance optimization, programming framework, application
migration, multi-cloud development, testing and debugging, etc. It also derives research trends, focus, and commonly-used platforms
for serverless computing, as well as promising research opportunities
A TxQoS-aware business transaction framework
In this thesis, we propose a transaction framework to provide comprehensive and flexible transaction support for contract-driven, service-oriented business processes. The research follows the research method outlined below. Initially, a thorough investigation on current state of affairs was made. Afterwards, we carried out a case study, which we utilized to identify the problems that are likely to occur during the execution of business processes. As the result of the solution design, the concepts, scenarios, life cycles, reference architectures, and mechanisms were proposed to address the problems. The design took place on the conceptual level, while the coding/programming and implementation is out of the scope of this thesis. The business-oriented solution design allows for transaction qualities to be specified and guaranteed by a contractual approach named as TxQoS (Transactional Quality of Service). The technology-oriented design enables flexible composition of ATCs (Abstract Transaction Constructs) as a transaction schema to support the execution of complex processes. As the last step of research, we validated the feasibility of our design by a utility study conducted in a large telecom project, which has complex processes that are service-oriented and contract-driven. Finally, we discussed the contributions and limitations of the research. The main contribution of the thesis is the BTF (Business Transaction Framework) that addresses process execution reliability. The TxQoS approach enables the specification of transaction qualities in terms of FIAT (Fluency, Interference, Alternation, Transparency) properties. This businessfriendly approach allows the providers and users to agree on transaction qualities before process execution time. The building blocks of the proposed framework, ATCs, are reusable and configurable templates, and are abstracted and generalized from existing transaction models. The various transaction requirements of sub-processes and process chunks can be represented by corresponding ATCs, which allow for a flexible composition. Integrated, the TxQoS and ATC approaches work together to form a TxQoS-aware business transaction framework
A Collaborative Visualization Framework Using JINI™ Technology
It is difficult to achieve mutual understanding of complex information between individuals that are separated geographically. Two well-known techniques commonly used to deal with this difficultly are collaboration and information visualization. This thesis develops a generic flexible framework that supports both collaboration and information visualization. It introduces the Collaborative Visualization Environment (COVE) framework, which simplifies the development of real-time synchronous multi-user applications by decoupling the elements of collaboration from the application. This allows developers to focus on building applications and leave the difficulties of collaboration (i.e., concurrency controls, user awareness, session management, etc.) to the framework. The framework uses an object sharing approach to share information and views between participants in a collaborative session. This approach takes advantage of several Java technologies (i.e., JavaBeans™, Jini™, and JavaSpaces™). JavaBeans™ establish a well-known standard for applications to operate within the framework. Jini™ services provide framework stability and enable code sharing across the network. Objects are shared between remote clients through the JavaSpaces™ service
Balancing truth error and manual processing in the PDQ system
Production Data Quality (PDQ) is a specialized pattern classifier whose main purpose is to assess independently the data quality of a production classifier. It accomplishes this by producing a high quality Truth from the source input, and then using the Truth to identify errors in the production classifier\u27s output data. Previous studies have shown close agreement between PDQ processing outcomes and a particular mathematical model of the system. In this study we describe and analyze an expanded model that addresses the potential tradeoff between Truth error and manual processing in PDQ, with an eye towards informing operational decisions about precision and efficiency. Using statistical data from the 2010 Census PDQ system as input, we examine the predictions of the new model in order to understand their potential usefulness. The outcomes show strong agreement between two methods for estimating Projected Truth error rate, supporting the validity of both methods as well as the existing static model. In addition, the new Projector model gives tight bounds on the projected manual processing rate and reveals a characteristic relationship between Projected Truth error and projected manual processing. We explore a practical application of this model for tuning PDQ, and we find an opportunity to achieve a 60% efficiency increase for the selected sample, while maintaining an acceptable degree of precision
Shattered Sky: An Exploration in Rising Drama
Shattered Sky is a dialogue-based RPG that focuses on utilizing a goal-based NPC architecture and a drama management algorithm to dynamically create an interactive story and role-playing experience. In Shattered Sky the sequence of events is unscripted and determined programmatically. Through a design process that included face-to-face role play testing, we developed a ten to fifteen minute single-player game that occurs during a political summit. We developed a detailed back story and defined and characterized how each of the five NPC’s in the game will behave. Shattered Sky features six models that were created using a combination of Maya, Photoshop, and ZBrush. We also developed an innovative testing system that could evaluate how fun the narrative was, and iteratively refine the game
Recommended from our members
Dynamic integrated modelling of information systems and business process simulation
This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.Business processes and information technology are two areas that are very closely related to the sustained competitive advantage in organisations. However, investment in information technology often leads to disappointment, which may in part be due to the non-alignment of the information system domain with the business process domain.
Simulation modelling is an established technique often used in business process change projects, as it allows a comparison of different possible scenarios without the expense of physically implementing the system. However business process simulation fails to effectively capture the information systems perspective in the model. This thesis contends that by combining information systems modelling techniques with business process simulation the model will be able to capture all the four perspectives (functional, behavioural, organisational and informational) of an organisation, and the design of the business processes and the information system will be better aligned.
Initially, attempts were made to integrate business process simulation with computer network simulation in a simple two- or three-layered simulation model, but this gave rise to significant problems the most significant being the underlying assumptions of the original hypothesis. This led to a refined hypothesis in which the layered models were discarded along with the network domain.
The revised hypothesis aimed to capture the informational changes that occur in the information system and therefore combines prototyping with business process simulation. This overcomes the unsafe assumptions of the initial hypothesis about whether the system is 'correct' and provides a method of validating the design of the information system within the context of the business processes. The integrated model allows concurrent design of the information system domain and the business process domain and therefore ensures that the domains are better aligned. The framework is tested on a case study and the results indicate that it is an effective tool in the combined design of business processes and information systems
Recommended from our members
Initialisation Problems in Feature Composition
Composing features that have inconsistent requirements may lead to feature interactions that violate requirements satisfied by each feature in isolation. These interactions manifest themselves as conflicts on shared resources. Arbitration is a common approach to resolving such conflicts that uses prioritisation to decide which feature has access to resources when there is a conflict. However, arbitration alone does not guarantee satisfaction of the requirement of the feature that eventually gains access to a resource. This is because arbitration does not take into account that the resource may be in a state that is inconsistent with that expected by the feature. We call this the initialisation problem.
In this thesis we propose an approach to addressing the initialisation problem which combines arbitration with contingencies. Contingency means having several specifications per feature satisfying the same requirement, depending on the current resource state. We illustrate and validate our approach by applying it to resolving conflicts between features in smart home and automotive domains. The validation shows that contingencies complement arbitration by enabling satisfaction of the requirement of the feature that eventually gains access to a shared resource, regardless of the current state of the resource.
The main contribution of this thesis is an approach to analysing initialisation concerns in feature composition. At the core of our approach is an explicit consideration of all possible states of a resource as potential initial states. Given each initial state we then derive corresponding specifications that would enable a feature to satisfy its requirement in those states. We show that our approach to initialisation problems is relevant to addressing the feature interaction problem by characterising some types of conflicts as initialisation concerns
Mecanismos dinâmicos de segurança para redes softwarizadas e virtualizadas
The relationship between attackers and defenders has traditionally been
asymmetric, with attackers having time as an upper hand to devise an exploit
that compromises the defender. The push towards the Cloudification of
the world makes matters more challenging, as it lowers the cost of an attack,
with a de facto standardization on a set of protocols. The discovery of a vulnerability
now has a broader impact on various verticals (business use cases),
while previously, some were in a segregated protocol stack requiring independent
vulnerability research. Furthermore, defining a perimeter within a cloudified
system is non-trivial, whereas before, the dedicated equipment already
created a perimeter. This proposal takes the newer technologies of network
softwarization and virtualization, both Cloud-enablers, to create new dynamic
security mechanisms that address this asymmetric relationship using novel
Moving Target Defense (MTD) approaches. The effective use of the exploration
space, combined with the reconfiguration capabilities of frameworks like
Network Function Virtualization (NFV) and Management and Orchestration
(MANO), should allow for adjusting defense levels dynamically to achieve the
required security as defined by the currently acceptable risk. The optimization
tasks and integration tasks of this thesis explore these concepts. Furthermore,
the proposed novel mechanisms were evaluated in real-world use cases, such
as 5G networks or other Network Slicing enabled infrastructures.A relação entre atacantes e defensores tem sido tradicionalmente assimétrica,
com os atacantes a terem o tempo como vantagem para conceberem
uma exploração que comprometa o defensor. O impulso para a Cloudificação
do mundo torna a situação mais desafiante, pois reduz o custo de um
ataque, com uma padronização de facto sobre um conjunto de protocolos.
A descoberta de uma vulnerabilidade tem agora um impacto mais amplo em
várias verticais (casos de uso empresarial), enquanto anteriormente, alguns
estavam numa pilha de protocolos segregados que exigiam uma investigação
independente das suas vulnerabilidades. Além disso, a definição de um
perímetro dentro de um sistema Cloud não é trivial, enquanto antes, o equipamento
dedicado já criava um perímetro. Esta proposta toma as mais recentes
tecnologias de softwarização e virtualização da rede, ambas facilitadoras da
Cloud, para criar novos mecanismos dinâmicos de segurança que incidem sobre
esta relação assimétrica utilizando novas abordagens de Moving Target
Defense (MTD). A utilização eficaz do espaço de exploração, combinada com
as capacidades de reconfiguração de frameworks como Network Function
Virtualization (NFV) e Management and Orchestration (MANO), deverá permitir
ajustar dinamicamente os níveis de defesa para alcançar a segurança
necessária, tal como definida pelo risco actualmente aceitável. As tarefas de
optimização e de integração desta tese exploram estes conceitos. Além disso,
os novos mecanismos propostos foram avaliados em casos de utilização no
mundo real, tais como redes 5G ou outras infraestruturas de Network Slicing.Programa Doutoral em Engenharia Informátic
- …