scholarly journals MSN: A Playground Framework for Design and Evaluation of MicroServices-Based sdN Controller

2021 ◽  
Vol 30 (1) ◽  
Author(s):  
Sisay Tadesse Arzo ◽  
Domenico Scotece ◽  
Riccardo Bassoli ◽  
Daniel Barattini ◽  
Fabrizio Granelli ◽  
...  

AbstractSoftware-defined networking decouples control and data plane in softwarized networks. This allows for centralized management of the network, but complete centralization of the controller functions raises potential issues related to failure, latency, and scalability. Distributed controller deployment is adopted to optimize scalability and latency problems. However, existing controllers are monolithic, resulting in code inefficiency for distributed deployment. Some seminal ongoing efforts have been proposed with the idea of disaggregating the SDN controller architecture into an assembly of various subsystems, each of which can be responsible for a certain controller task. These subsystems are typically implemented as microservices and deployed as virtual network functions, in particular as Docker Containers. This enables flexible deployment of controller functions. However, these proposals (e.g., $$\mu$$ μ ONOS) are still in their early stage of design and development, so that a full decomposition of the SDN controller is not been available yet. To fill that gap, this article derives some important design guidelines to decompose an SDN controller into a set of microservices. Next, it also proposes a microservices-based decomposed controller architecture, foreseeing communications issues between the controller sub-functions. These design and performance considerations are also proven via the implementation of the proposed architecture as a solution, called Micro-Services based SDN controller (MSN), based on the Ryu SDN controller. Moreover, MSN includes different network communication protocols, such as gRPC, WebSocket, and REST-API. Finally, we show experimental results that highlight the robustness and latency of the system on a networking testbed. Collected results prove the main pros and cons of each network communication protocol and an evaluation of our proposal in terms of system resilience, scalability and latency.

Author(s):  
Ahmed Abdalla ◽  
Suhad Mohammed ◽  
Tang Bin ◽  
Jumma Mary Atieno ◽  
Abdelazeim Abdalla

This paper considers the problem of estimating the direction of arrival (DOA) for the both incoherent and coherent signals from narrowband sources, located in the far field in the case of uniform linear array sensors. Three different methods are analyzed. Specifically, these methods are Music, Root-Music and ESPRIT. The pros and cons of these methods are identified and compared in light of different viewpoints. The performance of the three methods is evaluated, analytically, when possible, and by Matlab simulation. This paper can be a roadmap for beginners in understanding the basic concepts of DOA estimation issues, properties and performance.


Author(s):  
Andrea Petetta ◽  
Massimo Virgili ◽  
Stefano Guicciardi ◽  
Alessandro Lucchetti

AbstractStock overexploitation, bycatch, discards and gear impacts on the environment are outstanding issues for Mediterranean fisheries. The adoption of alternative fishing gears is an appealing solution to ensure a more sustainable exploitation of resources. We discuss the pros and cons of pots as alternative gears by reviewing their main designs, spatial distribution and target species in the Mediterranean basin. We assessed the technical factors affecting the catch efficiency of the different pot designs for four target species: spiny lobster, Palinurus elephas; Norway lobster, Nephrops norvegicus; common octopus, Octopus vulgaris and pandalid shrimps, Plesionika spp. We found that pot volume is important to catch Octopus; mesh size to catch Nephrops and Plesionika; entrance surface to catch Octopus, Nephrops and Plesionika; pot shape/colour and entrance shape/position to catch Octopus and Plesionika; and bait type to catch Octopus and Nephrops. The literature review shows that pot fisheries have several considerable advantages over conventional gears, especially in terms of discards, bycatch, seabed impacts (particularly compared with bottom trawls and passive set nets), size and species selectivity, gear depredation, catch quality and gear cost, besides saving time and labour. Disadvantages hampering their wider diffusion include ghost fishing, a low catch of finfish species, the narrow range of species targeted by each pot design and the current early stage of research. These data make a clear case for using pots as alternative gears to traditional ones in the Mediterranean Sea in some areas and seasons to catch certain target species.


Author(s):  
Sudhakar Y. Reddy

Abstract This paper describes HIDER, a methodology that enables detailed simulation models to be used during the early stages of system design. HIDER uses a machine learning approach to form abstract models from the detailed models. The abstract models are used for multiple-objective optimization to obtain sets of non-dominated designs. The tradeoffs between design and performance attributes in the non-dominated sets are used to interactively refine the design space. A prototype design tool has been developed to assist the designer in easily forming abstract models, flexibly defining optimization problems, and interactively exploring and refining the design space. To demonstrate the practical applicability of this approach, the paper presents results from the application of HIDER to the system-level design of a wheel loader. In this demonstration, complex simulation models for cycle time evaluation and stability analysis are used together for early-stage exploration of design space.


2015 ◽  
Author(s):  
William A. Hockberger

The Quadrimaran was invented in France in the mid-1980s by Daniel Tollet. It was an inspired design and a radical departure from traditional ship design by a man from outside the marine industry unconstrained by industry technical practices and education. Technical experts could see it would entail more structure and subsystems than other high-performance vessels, but its promise was that those penalties would be more than offset by its claimed low power and fuel consumption. A prototype/demonstrator, Alexander, was built in 1990 and operated for five years carrying and impressing many hundreds of riders. Alexander performed beautifully and appeared to bear out what was claimed. Contracts for several Quadrimarans of different sizes came quickly, especially considering how conservative an industry this is. That was significantly due to Tollet's personal charisma and skill in selling riders on the dream of carrying passengers and freight over the water fast and in comfort, yet economically. Great skepticism prevailed in some quarters, especially among naval architects knowledgeable about AMVs (advanced marine vehicles) and early-stage whole-ship design. At technical meetings, one Quadrimaran principal would comment, for example, "Why would you carry freight across the Atlantic at 38 knots on 230,000 horsepower (a reference to the planned Fastship Atlantic TG-770) when you could do it at 60 knots on only 65,000 horsepower?" Listeners would ask how this could be possible, and he would assert again that the Quadrimaran could do it, but would decline to explain. Respected technical people were working with Tollet and his company and becoming convinced of the Quadrimaran's merit. Along with the contracts came engineers with experience in ship detail design and construction (very different from early-stage whole-ship design), or responsibilities for assessing and approving ships for service. Others were with engine and equipment suppliers. Their opinion that there was something unique and special about the Quadrimaran gave it credibility and influenced more people to accept the major claims made for it. Some dismissed the most extreme claims but still accepted the idea that the Quadrimaran was capable of unusually high performance - considerably less than was being claimed, perhaps, but high nevertheless. In hindsight it is clear the skeptics were right. Results never met expectations, nor could they have. In reality, the Quadrimaran has aspects that inherently prevent it from achieving the characteristics and performance its inventor believed attainable. It cannot be built in a commercially useful size and actually perform as intended. Why this is so will be explained. A crucial fact in the Quadrimaran's history is that Daniel Tollet and his close associates believed strongly that naval architects and engineers who had been immersed in working with the existing ship types would be unable to give the Quadrimaran the very different treatment they believed it required. (Their own educations and professional work were nontechnical.) Such people were excluded from the development of Quadrimaran designs, and the belated discovery of many fundamental technical problems can be attributed to this. The company Tollet established had a number of names over the years, and other associated entities were created at times for various purposes. In this paper they are referred to collectively as QIH (Quadrimaran International Holdings) so as not to confuse things unnecessarily. In 2004 QuadTech Marine LLC was established and acquired the Quadrimaran patent (US Patent No. 5,191,849) and related intellectual property from QIH. QuadTech laid out an extensive R&D program to close gaps in the technical background and address identified issues. In the process, additional information on earlier QIH projects and products was obtained and studied, which brought to light problems that significantly compromised the Quadrimaran's prospective performance and utility. The resulting much-reduced set of potential uses and users led the company to effectively stop pursuing Quadrimaran projects after 2009. (Note: The author was Chief Technology Officer for QuadTech Marine during 2006-9, studying the Quadrimaran and planning the R&D.)


Author(s):  
Rakesh Murthy ◽  
Aditya N. Das ◽  
Dan O. Popa

Heterogeneous assembly at the microscale has recently emerged as a viable pathway to constructing 3-dimensional microrobots and other miniaturized devices. In contrast to self-assembly, this method is directed and deterministic, and is based on serial or parallel microassembly. Whereas at the meso and macro scales, automation is often undertaken after, and often benchmarked against manual assembly, we demonstrate that deterministic automation at the MEMS scale can be completed with higher yields through the use of engineered compliance and precision robotic cells. Snap fasteners have long been used as a way to exploit the inherent stability of local minima of the deformation energy caused by interference during part mating. In this paper we assume that the building blocks are 2 1/2 -dimensional, as is the case with lithographically microfabricated MEMS parts. The assembly of the snap fasteners is done using μ3, a multi-robot microassembly station with unique characteristics located at our ARRI’s Texas Microfactory lab. Experiments are performed to demonstrate that fast and reliable assemblies can be expected if the microparts and the robotic cell satisfy a so-called “High Yield Assembly Condition” (H.Y.A.C.). Important design trade-offs for assembly and performance of microsnap fasteners are discussed and experimentally evaluated.


2020 ◽  
Author(s):  
Maria Zozaya-Montes ◽  
Nicola Schiavottiello

The UNESCO World Heritage city of Évora (Portugal) hosted the second Heritales – International Heritage Film Festival in September 2017. In this edition the festival focused on current and past sustainable communities, selecting works that explored and problematized the relationship and coexistence of modernity and sustainability when applied to human groups and societies. The films presented the everyday life, knowledge, crafts and know-how of ordinary people highlighting the changes and challenges that the expansion of consumer-based economies, globalization and world politics have brought. As organizers, by focusing on sustainability in heritage context, we wanted to go beyond current preservation strategies of the tangible and intangible heritage, to promote a reflection on the “culture of sustainability” itself, looking at how sustainable ways-of-existence have characterized various communities and cultural practices worldwide. Since its first edition, the festival has been a space for the promotion of a critical understanding of cultural heritage, aimed to the broader public. By using emblematic historical places as stage, Heritales has challenged the mainstream cultural heritage scientific communication. Its proposal is to approach heritage’s issues through multiple types of media and artistic work such as films and documentaries but also cultural heritage’s games, exhibitions, theatre and performance, with talks and several communication strategies to facilitate the encounter between the authors and the public. Although the festival has received many positive feedbacks and the support of various entities such as the UNESCO Chair of the University of Évora (Portugal) and the FCT (Science and Technology Foundation, Portugal) it is still at its early stage of action. In this paper we would like to present the results of our experiment and analyse its concept and results, so that more collaborative and sustainable methodologies can also become a part of our plan of actionfor the organization of future events.


2018 ◽  
Vol 3 (13) ◽  
pp. 149 ◽  
Author(s):  
Nattha Savavibool ◽  
Birgitta Gatersleben ◽  
Chumporn Moorapun

In the work environment, colour is considered an important design element used to improve aesthetic qualities of the environment and for a company’s branding. This paper reviews existing research on the effects of workplace colour on worker’s mood, wellbeing and other work-related outcomes. In total 40 papers fitted the inclusion criteria and were included in the review. The results show a significant influence of colour on affect (e.g. mood, emotion), wellbeing (e.g. stress, comfort, wellbeing), and performance (e.g. productivity, performance, creativity). The review concludes with suggestions for further research.Keywords: Colour perception; Colour psychology; Effect of colour; Work environment.eISSN 2398-4295 © 2018. The Authors. Published for AMER ABRA cE-Bs by e-International Publishing House, Ltd., UK. This is an open-access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Peer–review under responsibility of AMER (Association of Malaysian Environment-Behaviour Researchers), ABRA (Association of Behavioural Researchers on Asians) and cE-Bs (Centre for Environment-Behaviour Studies), Faculty of Architecture, Planning & Surveying, Universiti Teknologi MARA, Malaysia. DOI: http://dx.doi.org/10.21834/ajbes.v3i13.152


2014 ◽  
pp. 1512-1529
Author(s):  
Margee Hume ◽  
Paul Johnston ◽  
Mark Argar ◽  
Craig Hume

This chapter focuses on addressing: the screening criteria used to evaluate potential new energy- related technology ventures in two international markets, namely the Philippines and Brazil; adopting a single case methodology to communicate the firm strategies used to attract investment and the behaviour adopted to try and effectively and efficiently enter the global market; and based on the descriptions and behaviours found, the case offers a holistic entry framework which will advance understanding of transcultural marketing and entry needs of the Philippines and Brazil regarding new energy-related innovations. This chapter uses qualitative case analysis of a single case technology commercialisation organisation and the experience of entering two new world markets: the Philippines and Brazil. These two markets have been selected as they are focused on energy securitisation, possess a distinct business culture related to early stage and Venture Capital (VC) investment and the behaviour of VCs, and are currently commercially attractive and interested in international investment and new technology market development (Broad & Cavanagh, 2011; Castells, 2011). This chapter reports on data focused on investment activity within the technology market in Brazil and the Philippines and cultural factors affecting investment and market entry specific to these markets. The chapter integrates the cultural issues of each destination with current literature and develops a checklist of actions related to each market destination. The chapter will assist with the success of attracting investment, sales growth, and performance in the new market and enhance profitability of the venture. The chapter will offer specific actions related to the entry and investment in each market and contribute to international marketing knowledge. This chapter offers a new transcultural marketing perspective on international venture capital exploring and learning from these two diverse emerging world markets. The lessons learnt from each market creates a shared and advanced outlook on seeking successful venture capital in newer global markets (Broad & Cavanagh, 2011).


Author(s):  
Miguel Bordallo López

Computer vision can be used to increase the interactivity of existing and new camera-based applications. It can be used to build novel interaction methods and user interfaces. The computing and sensing needs of this kind of applications require a careful balance between quality and performance, a practical trade-off. This chapter shows the importance of using all the available resources to hide application latency and maximize computational throughput. The experience gained during the developing of interactive applications is utilized to characterize the constraints imposed by the mobile environment, discussing the most important design goals: high performance and low power consumption. In addition, this chapter discusses the use of heterogeneous computing via asymmetric multiprocessing to improve the throughput and energy efficiency of interactive vision-based applications.


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