20,320 research outputs found
Resource optimization of edge servers dealing with priority-based workloads by utilizing service level objective-aware virtual rebalancing
IoT enables profitable communication between sensor/actuator devices and the cloud. Slow network causing Edge data to lack Cloud analytics hinders real-time analytics adoption. VRebalance solves priority-based workload performance for stream processing at the Edge. BO is used in VRebalance to prioritize workloads and find optimal resource configurations for efficient resource management. Apache Storm platform was used with RIoTBench IoT benchmark tool for real-time stream processing. Tools were used to evaluate VRebalance. Study shows VRebalance is more effective than traditional methods, meeting SLO targets despite system changes. VRebalance decreased SLO violation rates by almost 30% for static priority-based workloads and 52.2% for dynamic priority-based workloads compared to hill climbing algorithm. Using VRebalance decreased SLO violations by 66.1% compared to Apache Storm\u27s default allocation
Aerated blast furnace slag filters for enhanced nitrogen and phosphorus removal from small wastewater treatment plants
Rock filters (RF) are a promising alternative technology for natural
wastewater treatment for upgrading WSP effluent. However, the application
of RF in the removal of eutrophic nutrients, nitrogen and phosphorus, is very
limited. Accordingly, the overall objective of this study was to develop a lowcost
RF system for the purpose of enhanced nutrient removal from WSP
effluents, which would be able to produce effluents which comply with the
requirements of the EU Urban Waste Water Treatment Directive (UWWTD)
(911271lEEC) and suitable for small communities. Therefore, a combination
system comprising a primary facultative pond and an aerated rock filter
(ARF) system-either vertically or horizontally loaded-was investigated at
the University of Leeds' experimental station at Esholt Wastewater
Treatment Works, Bradford, UK.
Blast furnace slag (BFS) and limestone were selected for use in the ARF
system owing to their high potential for P removal and their low cost. This
study involved three major qperiments: (1) a comparison of aerated
vertical-flow and horizontal-flow limestone filters for nitrogen removal; (2) a
comparison of aerated limestone + blast furnace slag (BFS) filter and
aerated BFS filters for nitrogen and phosphorus removal; and (3) a
comparison of vertical-flow and horizontal-flow BFS filters for nitrogen and
phosphorus removal.
The vertical upward-flow ARF system was found to be superior to the
horizontal-flow ARF system in terms of nitrogen removal, mostly thiough
bacterial nitrification processes in both the aerated limestone and BFS filter
studies. The BFS filter medium (whieh is low-cost) showed a much higher
potential in removing phosphortls from pond effluent than the limestone
medium. As a result, the combination of a vertical upward-flow ARF system
and an economical and effective P-removal filter medium, such as BFS,
was found to be an ideal optionfor the total nutrient removal of both nitrogen
and phosphorus from wastewater.
In parallel with these experiments, studies on the aerated BFS filter effective
life and major in-filter phosphorus removal pathways were carried out. From
the standard batch experiments of Pmax adsorption capacity of BFS, as well
as six-month data collection of daily average P-removal, it was found that
the effective life of the aerated BFS filter was 6.5 years. Scanning electron
microscopy and X-ray diffraction spectrometric analyses on the surface of
BFS, particulates and sediment samples revealed that the apparent
mechanisms of P-removal in the filter are adsorption on the amorphous
oxide phase of the BFS surface and precipitation within the filter
An overview of decision table literature 1982-1995.
This report gives an overview of the literature on decision tables over the past 15 years. As much as possible, for each reference, an author supplied abstract, a number of keywords and a classification are provided. In some cases own comments are added. The purpose of these comments is to show where, how and why decision tables are used. The literature is classified according to application area, theoretical versus practical character, year of publication, country or origin (not necessarily country of publication) and the language of the document. After a description of the scope of the interview, classification results and the classification by topic are presented. The main body of the paper is the ordered list of publications with abstract, classification and comments.
Data-driven through-life costing to support product lifecycle management solutions in innovative product development
Innovative product usually refers to product that comprises of creativity and new ideas. In the development of such a new product, there is often a lack of historical knowledge and data available to be used to perform cost estimation accurately. This is due to the fact that traditional cost estimation methods are used to predict costs only after a product model has been built, and not at an early design stage when there is little data and information available.
In light of this, original equipment manufacturers are also facing critical challenges of becoming globally competitive and increasing demands from customer for continuous innovation. To alleviate these situations this research has identified a new approach to cost modelling with the inclusion of product lifecycle management solutions to address innovative product development.The aim of this paper, therefore, is to discuss methods of developing an extended-enterprise data-driven through-life cost estimating method for innovative product development
Eighth reliability assessment for the orbiting geophysical observatories, addendum
Performance test summary and hardware reliability for orbiting geophysical observatorie
Integrated product and process development methodologies for environmentally conscious electronic products
This research focuses on integrated product and process development (IPPD) methodologies for environmentally conscious electronic products. After a review of current research issues in the field of product and process development, a generic framework for IPPD is proposed which describes most of the concerned issues formally as constrained optimization problems. These problems may include such optimization objectives as cost, benefit, and environmental impact. Based on this framework, an IPPD methodology is proposed as a systems approach to competitive and environmentally conscious product and process development. A case study on personal computer development is performed illustrating how to apply the methodology meaningfully and efficiently. Eco-compass concept is then integrated into the methodology to evaluate environmental impact, and a case study on business telephone development is performed. To automate the design of products and processes, a solution methodology for IPPD based on logical representation of process relations is proposed with two illustrating product development examples. Finally, a timed IPPD methodology is introduced with increased modeling capability and decision accuracy. It considers the execution duration of processes and their time-varying characteristics. The timed methodology is applied to the life cycle development of flexible manufacturing systems (FMSs) and provides a new way to develop cost-effective, high-quality, and environmentally conscious FMSs
Integrating Aircraft Cost Modeling into Conceptual Design
The article presents cost modeling results from the application of the Genetic-Causal cost modeling principle. Industrial results from redesign are also presented to verify the opportunity for early concept cost optimization by using Genetic-Causal cost drivers to guide the conceptual design process for structural assemblies. The acquisition cost is considered through the modeling of the recurring unit cost and non-recurring design cost. The operational cost is modeled relative to acquisition cost and fuel burn for predominately metal or composites designs. The main contribution of this study is the application of the Genetic-Causal principle to the modeling of cost, helping to understand how conceptual design parameters impact on cost, and linking that to customer requirements and life cycle cost
Dynamic platform modeling for concurrent product-production reconfiguration
To meet a wide range of customer needs, a variety of product concepts can be modeled employing a platform approach. Whereas frequent market changes can be accommodated by dynamically modifying product concepts in iterations, capabilities in production are seldom well incorporated as part of design iterations. In this paper, a dynamic platform modeling approach that supports concurrent product-production reconfiguration is presented. The approach builds on Set-Based Concurrent Engineering (SBCE) processes and a function modeling technique is used to represent product-production variety streams inherent in a production operation model. To demonstrate the approach, a comprehensive case from the aerospace industry is presented. Conceptual representations of a set of aero engine sub-systems and a variety of welding configurations, including their inherent constraints, are mutually modeled and assessed. The results show that a set of product-production alternatives can be dynamically controlled by integrating product-production constraints using a production operation model. Following SBCE processes, inferior alternatives can be put aside until new information becomes available and a new set of alternatives can be reconfigured. The dynamics and concurrency of the approach can potentially reduce the risk of late and costly modifications that propagate from design to production
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