Selecting and Allocating Cubes in Multi-Node OLAP Systems

2011 ◽  
pp. 99-131
Author(s):  
Jorge Loureiro ◽  
Orlando Belo
Keyword(s):  
Cost Estimation ◽  
Cost Model ◽  
Storage Space ◽  
Communication Costs ◽  
Estimation Algorithms ◽  
Parallel Tasks ◽  
Maintenance Time ◽  
Dimension Space ◽  
And Storage ◽  
Linear Cost

OLAP queries are characterized by short answering times. Materialized cube views, a pre-aggregation and storage of group-by values, are one of the possible answers to that condition. However, if all possible views were computed and stored, the amount of necessary materializing time and storage space would be huge. Selecting the most beneficial set, based on the profile of the queries and observing some constraints as materializing space and maintenance time, a problem denoted as cube views selection problem, is the condition for an effective OLAP system, with a variety of solutions for centralized approaches. When a distributed OLAP architecture is considered, the problem gets bigger, as we must deal with another dimension—space. Besides the problem of the selection of multidimensional structures, there’s now a node allocation one; both are a condition for performance. This chapter focuses on distributed OLAP systems, recently introduced, proposing evolutionary algorithms for the selection and allocation of the distributed OLAP Cube, using a distributed linear cost model. This model uses an extended aggregation lattice as framework to capture the distributed semantics, and introduces processing nodes’ power and real communication costs parameters, allowing the estimation of query and maintenance costs in time units. Moreover, as we have an OLAP environment, whit several nodes, we will have parallel processing and then, the evaluation of the fitness of evolutionary solutions is based on cost estimation algorithms that simulate the execution of parallel tasks, using time units as cost metric.

scholarly journals A Two-Stage Offline-to-Online Multiobjective Optimization Strategy for Ship Integrated Energy System Economical/ Environmental Scheduling Problem

Complexity ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Qing An ◽  
Jun Zhang ◽  
Xin Li ◽  
Xiaobing Mao ◽  
Yulong Feng ◽  
...  
Keyword(s):  
Multiobjective Optimization ◽  
Real World ◽  
Operation Time ◽  
Energy System ◽  
Scheduling Problem ◽  
Storage Space ◽  
Optimization Strategy ◽  
Two Stage ◽  
Integrated Energy System ◽  
And Storage

The economical/environmental scheduling problem (EESP) of the ship integrated energy system (SIES) has high computational complexity, which includes more than one optimization objective, various types of constraints, and frequently fluctuated load demand. Therefore, the intelligent scheduling strategies cannot be applied to the ship energy management system (SEMS) online, which has limited computing power and storage space. Aiming at realizing green computing on SEMS, in this paper a typical SIES-EESP optimization model is built, considering the form of decision vectors, the economical/environmental optimization objectives, and various types of real-world constraints of the SIES. Based on the complexity of SIES-EESPs, a two-stage offline-to-online multiobjective optimization strategy for SIES-EESP is proposed, which transfers part of the energy dispatch online computing task to the offline high-performance computer systems. The specific constraints handling methods are designed to reduce both continuous and discrete constraints violations of SIES-EESPs. Then, an establishment method of energy scheduling scheme-base is proposed. By using the big data offline, the economical/environmental scheduling solutions of a typical year can be obtained and stored with more computing resources and operation time on land. Thereafter, a short-term multiobjective offline-to-online optimization approach by SEMS is considered, with the application of multiobjective evolutionary algorithm (MOEA) and typical schemes corresponding to the actual SIES-EESPs. Simulation results show that the proposed strategy can obtain enough feasible Pareto solutions in a shorter time and get well-distributed Pareto sets with better convergence performance, which can well adapt to the features of real-world SIES-EESPs and save plenty of operation time and storage space for the SEMS.

scholarly journals Making Education Collections Safe to Touch: Safety Assessments and Data Maintenance

2018 ◽  
Vol 2 ◽  
pp. e28197
Author(s):  
Kelsey Falquero ◽  
Katherine Roberts ◽  
Jessica Nakano
Keyword(s):  
Natural History ◽  
Specimen Preparation ◽  
Museum Specimens ◽  
National Museum ◽  
Storage Space ◽  
Collections Management ◽  
Vertebrate Zoology ◽  
Education And Outreach ◽  
Safety Assessments ◽  
And Storage

Q?rius is an interactive learning venue at the Smithsonian National Museum of Natural History (NMNH) designed specifically for a teen audience. The space gives visitors a chance to interact with museum specimens, especially in the Collections Zone. The Q?rius collections are non-accessioned education collections, belonging to the Office of Education and Outreach (E&O). The collections include the Museum’s seven disciplines – Anthropology, Botany, Entomology, Invertebrate Zoology, Mineral Sciences, Paleobiology, and Vertebrate Zoology. Starting in 2013, collections staff began performing safety assessments on specimens before their rehousing and storage in the publicly accessible Collections Zone. Risks assessed include sharpness, ingestibility, radioactivity, and contaminants (such as arsenic, mercury, and lead, which were historically used in specimen preparation or for pest management). Specimen and object fragility was also assessed. The goal of these assessments was to minimize risks to our visitors and to our collections. The safety assessments allow collections staff to make housing recommendations that would ensure the safety of NMNH’s visitors and the preservation of E&O’s collections in a publicly accessible storage space. This practice now extends to other pre-existing learning venues that contain publicly accessible portions of the E&O Collection, further minimizing risks. Staff have started adding the data gathered by these safety assessments to our collections management system, to protect the data from loss and to make the information easily accessible to staff. This poster relates to a second poster, Establishing Legal Title for Non-Accessioned Collections.

System-of-Systems Cost Estimation

2011 ◽  
pp. 71-81
Author(s):  
Jo Ann Lane
Keyword(s):  
Cost Estimation ◽  
Cost Model ◽  
System Engineering ◽  
System Of Systems ◽  
Organizational Characteristics ◽  
Lead System ◽  
Traditional System ◽  
Know How ◽  
Architecture Development

As organizations strive to expand system capabilities through the development of system-of-systems (SoS) architectures, they want to know “how much effort” and “how long” to implement the SoS. In order to answer these questions, it is important to first understand the types of activities performed in SoS architecture development and integration and how these vary across different SoS implementations. This article provides results of research conducted to determine types of SoS lead system integrator (LSI) activities and how these differ from the more traditional system engineering activities described in Electronic Industries Alliance (EIA) 632 (“Processes for Engineering a System”). This research further analyzed effort and schedule issues on “very large” SoS programs to more clearly identify and profile the types of activities performed by the typical LSI and to determine organizational characteristics that significantly impact overall success and productivity of the LSI effort. The results of this effort have been captured in a reduced-parameter version of the constructive SoS integration cost model (COSOSIMO) that estimates LSI SoS engineering (SoSE) effort.

Governmental Service Transformation through Cost Scenarios Simulation

2012 ◽  
pp. 791-805
Author(s):  
Yannis Charalabidis
Keyword(s):  
Cost Estimation ◽  
Information Needs ◽  
Cost Model ◽  
Lessons Learned ◽  
Future Research ◽  
Activity Based Costing ◽  
Cost Calculations ◽  
System Interoperability ◽  
Definition Of ◽  
Office System

Formal methods for measuring the impact of interoperability on digital public services is emerging as an important research challenge in electronic government. The eGOVSIM model that is described in this chapter aims to provide administrations with a tool to calculate the gains from digitising and making interoperable services for citizens and businesses. The chapter presents existing methods for calculating the cost of services for the administration and the service consumers, such as the Standard Cost Model (SCM) and the Activity Based Costing (ABC). Then it goes on presenting a toolset for analytical cost calculations based on the various process steps and the information needs of each governmental service. The eGOVSIM toolset supports the definition of several service provision scenarios, such as front/back office system interoperability, cross-system or cross-organisational interoperability allowing the calculation of time, effort and cost elements, and relevant gains from the application of each scenario. Application results for two cases / scenarios are also presented, so that the reader can see the applicability and overall value of the approach. Lessons learned and future research directions for service cost estimation are also described.

scholarly journals ESTIMATING CAPITAL AND OPERATIONAL COSTS OF BACKHOE SHOVELS

2012 ◽  
Vol 18 (3) ◽  
pp. 378-385 ◽  
Author(s):  
Ahmad Reza Sayadi ◽  
Ali Lashgari ◽  
Mohammad Majid Fouladgar ◽  
Miroslaw J. Skibniewski
Keyword(s):  
Feasibility Study ◽  
Cost Estimation ◽  
Construction Projects ◽  
Cost Model ◽  
Operating Cost ◽  
Principal Component ◽  
Feasibility Studies ◽  
Project Managers ◽  
Cost Models ◽  
Optimum Type

Material loading is one of the most critical operations in earthmoving projects. A number of different equipment is available for loading operations. Project managers should consider different technical and economic issues at the feasibility study stage and try to select the optimum type and size of equipment fleet, regarding the production needs and project specifications. The backhoe shovel is very popular for digging, loading and flattening tasks. Adequate cost estimation is one of the most critical tasks in feasibility studies of equipment fleet selection. This paper presents two different cost models for the preliminary and detailed feasibility study stages. These models estimate the capital and operating cost of backhoe shovels using uni-variable exponential regression (UVER) as well as multi-variable linear regression (MVLR), based on principal component analysis. The UVER cost model is suitable for quick cost estimation at the early stages of project evaluation, while the MVLR cost function, which is more detailed, can be useful for the feasibility study stage. Independent variables of MVLR include bucket size, digging depth, dump height, weight and power. Model evaluations show that these functions could be a credible tool for cost estimations in prefeasibility and feasibility studies of mining and construction projects.

Study on Internal Layout of UK's Day Care Unit for Older People

2014 ◽  
Vol 507 ◽  
pp. 7-10
Author(s):  
Da Ke Wei ◽  
Hong Jin ◽  
Hong Yuan Mei
Keyword(s):  
Older People ◽  
Day Care ◽  
Public Spaces ◽  
Basic Type ◽  
Relative Location ◽  
Storage Space ◽  
Internal Circulation ◽  
Private And Public ◽  
The Relationship ◽  
And Storage

This study focuses on the internal layout of premises of UKs day care unit for older people, including possible combinations of rooms and spaces, access and circulation. All day units require a minimum of a dining/activity space, a kitchen, (a) toilet (s) and storage space, these rooms and spaces are combined into the basic type of premises. Depending on the aims of the unit, the number of places provided, and users' needs, many of the disadvantages associated with basic premises can be overcome if the premises have extra spaces. From the above analysis we can see that, in existing day unit premises, the number and type of rooms and spaces and how they are grouped together vary considerably, ranging from simple to complex arrangements. Also, the relationships between rooms and spaces in layouts for all day unit premises need to be pondered over, including distances between key rooms/spaces, the relative location of spaces in terms of their functions, the relationship between private and public spaces and the views within and between rooms, and from external windows. In addition, access and circulation of a day unit need to be considered carefully, including access to the day unit premises and the reception space and internal circulation.

Effectively and Efficiently Designing and Querying Parallel Relational Data Warehouses on Heterogeneous Database Clusters

2012 ◽  
Vol 23 (4) ◽  
pp. 17-51 ◽  
Author(s):  
Ladjel Bellatreche ◽  
Alfredo Cuzzocrea ◽  
Soumia Benkrid
Keyword(s):  
Storage Capacity ◽  
Cost Model ◽  
Hill Climbing ◽  
Data Allocation ◽  
Cost Models ◽  
Data Warehouses ◽  
Heterogeneous Database ◽  
Traditional Design ◽  
Processing Power ◽  
And Storage

In this paper, a comprehensive methodology for designing and querying Parallel Rational Data Warehouses (PRDW) over database clusters, called Fragmentation & Allocation (F&A) is proposed. F&A assumes that cluster nodes are heterogeneous in processing power and storage capacity, contrary to traditional design approaches that assume that cluster nodes are instead homogeneous, and fragmentation and allocation phases are performed in a simultaneous manner. In classical approaches, two different cost models are used to perform fragmentation and allocation, separately, whereas F&A makes use of one cost model that considers fragmentation and allocation parameters simultaneously. Therefore, according to the F&A methodology proposed, the allocation phase/decision is done at fragmentation. At the fragmentation phase, F&A uses two well-known algorithms, namely Hill Climbing (HC) and Genetic Algorithm (GA), which the authors adapt to the main PRDW design problem over heterogeneous database clusters, as these algorithms are capable of taking into account the heterogeneous characteristics of the reference application scenario. At the allocation phase, F&A introduces an innovative matrix-based formalism capable of capturing the interactions among fragments, input queries, and cluster node characteristics, driving the data allocation task accordingly, and a related affinity-based algorithm, called F&A-ALLOC. Finally, their proposal is experimentally assessed and validated against the widely-known data warehouse benchmark APB-1 release II.

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