125 research outputs found
The Impact of Data Replicatino on Job Scheduling Performance in Hierarchical data Grid
In data-intensive applications data transfer is a primary cause of job
execution delay. Data access time depends on bandwidth. The major bottleneck to
supporting fast data access in Grids is the high latencies of Wide Area
Networks and Internet. Effective scheduling can reduce the amount of data
transferred across the internet by dispatching a job to where the needed data
are present. Another solution is to use a data replication mechanism. Objective
of dynamic replica strategies is reducing file access time which leads to
reducing job runtime. In this paper we develop a job scheduling policy and a
dynamic data replication strategy, called HRS (Hierarchical Replication
Strategy), to improve the data access efficiencies. We study our approach and
evaluate it through simulation. The results show that our algorithm has
improved 12% over the current strategies.Comment: 11 pages, 7 figure
Net pay determination by Dempster rule of combination: Case study on Iranian offshore oil fields
International audienceNet pay detection is a key stage in reservoir characterization for several purposes: reserve estimation, reservoir modeling and simulation, production planning, etc. Determining productive zones always is simultaneous with some amount of uncertainty due to lack of enough data, insufficiency of knowledge and wild-nature of petroleum reservoirs. It becomes even more challenging in carbonates, because of their highly heterogeneous environment. Conventionally, evaluating net pays is done by applying petrophysical cutoffs on well-logs, which results in crisp classification of pay or non-pay zones. In addition, cutoff based method is developed in sandstones, and does not provide suitable results in carbonates at all. Proposed methodology of this work, Dempster-Shafer Theory, is a generalization of Bayesian Theory of conditional probabilities. Net pays are studied in two oil reservoirs by this theory; one of them is carbonate reservoir of Mishrif, the other is sandy Burgan reservoir. For validation, results 2 are compared to well tests and output of conventional cutoff method. The advantages of using Dempster-Shafer Theory, comparing to conventional cutoff based method in studying net pays is: to have a continuous fuzzy output, based on geological facts, with high generalization ability and more compatibility with well test data
Net pay determination by artificial neural network: Case study on Iranian offshore oil fields
International audienceDetermining productive zones has always been a challenge for petrophysicists. On the other hand, Artificial Neural Networks are powerful tools in solving identification problems. In this paper, pay zone determination is defined as an identification problem, and is tried to solve it by trained Neural Networks. Proposed methodology is applied on two datasets: one belongs to carbonate reservoir of Mishrif, the other belongs to sandy Burgan reservoir. The results showed high precision in classifying productive zones in predefined classes with Classification Correctness Rate of more than 85% in both geological conditions. Applicability of proposed pay zone determination procedure in carbonate environment is a great advantage of developed methodology. Fuzzified output, being independent of core tests and verification with well tests results are of other advantages of Neural Network-based method of pay zone detection
ISTRAŽIVANJE SVEOBUHVATNOGA MODELA ZA PROCJENU OBRADBENOGA I OKOLIŠNOGA RIZIKA KOD VAĐENJA ARHITEKTONSKO-GRAĐEVNOGA KAMENA
One of the most hazardous fields of engineering is mining operations and accordingly, it requires extra consideration on risk evaluation. Decorative stone quarrying is one of the main branches of the mining industry in Iran. Currently, Iran, China and Italy are known as the three main producers of decorative stones in the world. Subsequently, risk assessment is one of the main steps of quarrying organization. One of the main steps of risk assessment is Risk Breakdown Structure (RBS). In order to achieve this goal, a comprehensive structure of dimensional stone quarrying is modelled in this research and divided into 17 main levels. One of the most useful procedures of risk ranking is Multi attribute decision-making methods which state that they have numerous affecting parameters. In the next step of this study, the main hazards of main decorative stone quarrying are assessed by implementing the ‘Preference Ranking Organization Method for Enrichment Evaluation’ (PROMETHEE) technique. As a final point, Economical, Management, and Schedule risks are determined as the most intimidating hazards in this field.Jedna od najopasnijih inženjerskih aktivnosti jesu rudarske operacije koje stoga zahtijevaju dodatne procjene rizika. Vađenje ukrasnoga kamena jedna je od glavnih rudarskih grana u Iranu. Trenutačno su Iran, Kina i Italija tri glavna proizvođača takva kamena u svijetu. Procjena rizika među temeljnim je aktivnostima kamenoloma. Jedan od glavnih postupaka toga procesa jest procjena rizika loma strukture (RLS). S tim ciljem modelirane su makrostrukure arhitektonsko-građevnoga kamena te su podijeljene u 17 razina. Jedan od najboljih postupaka za rangiranje rizika jest višeatributna metoda donošenja odluka koja povezuje brojne zavisne parametre. Nadalje, ocijenjeni su glavni rizici u najvećim kamenolomima uporabom metode preferirajućega rangiranja za poboljšanu procjenu (MPRPP). Na kraju su izračunani ekonomski rizik te rizici upravljanja i planiranja, koji ujedno imaju najveći utjecaj na opisane aktivnosti
Bond behaviour of a stick shape CFRP reinforcement applied according to the NSM-ETS strengthening techniques
This paper investigates a hybrid strengthening technique that combines the near-surface-mounted (NSM) technique for flexural strengthening with the embedded through section (ETS) technique for shear strengthening using innovative stick-shaped CFRP rebars. The study focuses on the mechanical properties and bond behavior of 7 mm square-sectioned, 30°-bent CFRP rebars. The mechanical characteristics and bond behavior were evaluated by tensile testing, interlaminar shear tests, and direct pull-out tests. The results of the pull-out tests revealed FRP failure, showing a strong link between concrete and CFRP. The findings illustrate the efficiency of the hybrid NSM-ETS technique for reinforcing structures using stick-shaped CFRP laminates.This article is based upon work from COST Action CA18120 (CERTBOND - https://certbond.eu/), supported by COST (European Cooperation in Science and Technology). This study is also a part of the project ‘‘Sticker –Innovative technique for the structural strengthening based on using CFRP laminates with multifunctional attributes and applied with advanced cement adhesives’’, with the reference POCI-01-0247-FEDER-039755. This work was partly financed by FCT / MCTES through national funds (PIDDAC) under the R&D Unit Institute for Sustainability and Innovation in Structural Engineering (ISISE), under reference UIDB/04029/2020, and under the Associate Laboratory Advanced Production and Intelligent Systems ARISE under reference LA/P/0112/2020
Cochlear Implants: An Excursus into the Technologies and Clinical Applications
Hearing loss causes severe alterations in social function and daily communications. Cochlear device implantation (CDI) is the only beneficiary method for auditory rehabilitation in patients with severe to profound sensorineural hearing loss (SNHL). Regarding a report in 2014, over 300,000 people had received cochlear implants throughout the world since December 2012 among which about 60,000 were adults and 40,000 were children in the United States. In this chapter, we discuss the history, origin, mechanism of action, and type of cochlear implants, as well as method of surgery and complications
Non-identical parallel machines batch processing problem with release dates, due dates and variable maintenance activity to minimize total tardiness
[EN]
Combination of job scheduling and maintenance activity has been widely investigated in the literature. We consider a non-identical parallel machines batch processing (BP) problem with release dates, due dates and variable maintenance activity to minimize total tardiness. An original mixed integer linear programming (MILP) model is formulated to provide an optimal solution. As the problem under investigation is known to be strongly NP-hard, two meta-heuristic approaches based on Simulated Annealing (SA) and Variable Neighborhood Search (VNS) are developed. A constructive heuristic method (H) is proposed to generate initial feasible solutions for the SA and VNS. In order to evaluate the results of the proposed solution approaches, a set of instances were randomly generated. Moreover, we compare the performance of our proposed approaches against four meta heuristic algorithms adopted from the literature. The obtained results indicate that the proposed solution methods have a competitive behaviour and they outperform the other meta-heuristics in most instances. Although in all cases, H + SA is the most performing algorithm compared to the others.Beldar, P.; Moghtader, M.; Giret Boggino, AS.; Ansaripoord, AH. (2022). Non-identical parallel machines batch processing problem with release dates, due dates and variable maintenance activity to minimize total tardiness. Computers & Industrial Engineering. 168:1-28. https://doi.org/10.1016/j.cie.2022.10813512816
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