A Design of Approximate Voting Schemes for Fail-Operational Systems

With the ever tightening of budgets and legislation, new vessel builds are facing tough times. The future maritime industry requires more efficient vessels to minimise ship operational costs with cleaner technologies that meet stringent environment regulations, reduce greenhouse gas emissions, specifically carbon emissions. Emissions reduction continues to be high on the agenda for the marine industry, it is responsible for about 2.5 percent of global greenhouse emissions1 and is under great pressure to reduce its environmental impact. With pressure comes the opportunity to incentivize innovation, developments and implementation of energy efficient measures, both design and operational. Naval propulsion systems are no different from other industries, and the industry is exploring ways to optimise propulsion and electrical power generation systems architecture for better performance and efficiency. Electric technology plays a leading role. The paper will: Provide a brief overview about the hybrid propulsion concept, with key electrical, mechanical qualities and issues. Describe different designs configurations and performances of hybrid propulsion systems from demonstrated and operational systems in the commercial and naval world. Cover the lessons learnt in technologies and controls used on such systems. Examine future architectures including energy storage and explore the benefits and the flexibility these can bringto the hybrid propulsion sphere.

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A PCI-Based Evaluation Method for Level of Services for Traffic Operational Systems

IEEE Transactions on Intelligent Transportation Systems ◽

10.1109/tits.2006.883935 ◽

2006 ◽

Vol 7 (4) ◽

pp. 494-499 ◽

Cited By ~ 19

Author(s):

Shuming Tang ◽

Fei-Yue Wang

Keyword(s):

Evaluation Method ◽

Operational Systems

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Computer-assisted database indexing: the state-of-the-art

The Indexer The International Journal of Indexing ◽

10.3828/indexer.1994.19.1.6 ◽

1994 ◽

Vol 19 (1) ◽

pp. 23-27

Author(s):

Gail M. Hodge

Keyword(s):

Data Base ◽

Production System ◽

State Of The Art ◽

The State ◽

Computer Support ◽

Computer Assisted ◽

Computer Assistance ◽

The Future ◽

Database Indexing ◽

Operational Systems

Discusses the state-of-the-art in computer indexing, defines indexing and computer assistance, describes the reasons for renewed interest, identifies the types of computer support in use using selected operational systems, describes the integration of various computer supports in one data base production system, and speculates on the future.

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Merits of a 108-Member Ensemble System in ENSO and IOD Predictions

Journal of Climate ◽

10.1175/jcli-d-18-0193.1 ◽

2019 ◽

Vol 32 (3) ◽

pp. 957-972 ◽

Cited By ~ 14

Author(s):

Takeshi Doi ◽

Swadhin K. Behera ◽

Toshio Yamagata

Keyword(s):

Seasonal Prediction ◽

Ensemble Prediction ◽

Economic Losses ◽

Prediction System ◽

Ensemble Size ◽

Ensemble Prediction System ◽

Skill Scores ◽

Operational Systems ◽

The Indian Ocean ◽

Climate Events

This paper explores merits of 100-ensemble simulations from a single dynamical seasonal prediction system by evaluating differences in skill scores between ensembles predictions with few (~10) and many (~100) ensemble members. A 100-ensemble retrospective seasonal forecast experiment for 1983–2015 is beyond current operational capability. Prediction of extremely strong ENSO and the Indian Ocean dipole (IOD) events is significantly improved in the larger ensemble. It indicates that the ensemble size of 10 members, used in some operational systems, is not adequate for the occurrence of 15% tails of extreme climate events, because only about 1 or 2 members (approximately 15% of 12) will agree with the observations. We also showed an ensemble size of about 50 members may be adequate for the extreme El Niño and positive IOD predictions at least in the present prediction system. Even if running a large-ensemble prediction system is quite costly, improved prediction of disastrous extreme events is useful for minimizing risks of possible human and economic losses.

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Optimizing ETL by a Two-Level Data Staging Method

International Journal of Data Warehousing and Mining ◽

10.4018/ijdwm.2016070103 ◽

2016 ◽

Vol 12 (3) ◽

pp. 32-50

Author(s):

Xiufeng Liu ◽

Nadeem Iftikhar ◽

Huan Huo ◽

Per Sieverts Nielsen

Keyword(s):

Data Warehouse ◽

Data Warehousing ◽

Data Extraction ◽

Data Staging ◽

Staging Area ◽

Level Data ◽

Different Types ◽

Operational Systems ◽

Early Late ◽

Central Data

In data warehousing, the data from source systems are populated into a central data warehouse (DW) through extraction, transformation and loading (ETL). The standard ETL approach usually uses sequential jobs to process the data with dependencies, such as dimension and fact data. It is a non-trivial task to process the so-called early-/late-arriving data, which arrive out of order. This paper proposes a two-level data staging area method to optimize ETL. The proposed method is an all-in-one solution that supports processing different types of data from operational systems, including early-/late-arriving data, and fast-/slowly-changing data. The introduced additional staging area decouples loading process from data extraction and transformation, which improves ETL flexibility and minimizes intervention to the data warehouse. This paper evaluates the proposed method empirically, which shows that it is more efficient and less intrusive than the standard ETL method.

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Operational ocean models in the Adriatic Sea: a skill assessment

Ocean Science ◽

10.5194/os-4-61-2008 ◽

2008 ◽

Vol 4 (1) ◽

pp. 61-71 ◽

Cited By ~ 25

Author(s):

J. Chiggiato ◽

P. Oddo

Keyword(s):

General Circulation ◽

Mean Squared Error ◽

Three Dimensional ◽

Circulation Model ◽

Remote Sensing Data ◽

Skill Assessment ◽

Regional Models ◽

Operational Systems ◽

Forecasting System ◽

The Mediterranean

Abstract. In the framework of the Mediterranean Forecasting System (MFS) project, the performance of regional numerical ocean forecasting systems is assessed by means of model-model and model-data comparison. Three different operational systems considered in this study are: the Adriatic REGional Model (AREG); the Adriatic Regional Ocean Modelling System (AdriaROMS) and the Mediterranean Forecasting System General Circulation Model (MFS-GCM). AREG and AdriaROMS are regional implementations (with some dedicated variations) of POM and ROMS, respectively, while MFS-GCM is an OPA based system. The assessment is done through standard scores. In situ and remote sensing data are used to evaluate the system performance. In particular, a set of CTD measurements collected in the whole western Adriatic during January 2006 and one year of satellite derived sea surface temperature measurements (SST) allow to asses a full three-dimensional picture of the operational forecasting systems quality during January 2006 and to draw some preliminary considerations on the temporal fluctuation of scores estimated on surface quantities between summer 2005 and summer 2006. The regional systems share a negative bias in simulated temperature and salinity. Nonetheless, they outperform the MFS-GCM in the shallowest locations. Results on amplitude and phase errors are improved in areas shallower than 50 m, while degraded in deeper locations, where major models deficiencies are related to vertical mixing overestimation. In a basin-wide overview, the two regional models show differences in the local displacement of errors. In addition, in locations where the regional models are mutually correlated, the aggregated mean squared error was found to be smaller, that is a useful outcome of having several operational systems in the same region.

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Schizophrenia: comparison of 13 diagnostic systems in a cross-sectional study1

European Psychiatry ◽

10.1017/s0924933800001498 ◽

1993 ◽

Vol 8 (1) ◽

pp. 7-13 ◽

Cited By ~ 5

Author(s):

S Dollfus ◽

M Petit ◽

JF Menard ◽

P Lesieur

Keyword(s):

Diagnostic System ◽

Cross Sectional Study ◽

Diagnostic Systems ◽

Cross Sectional ◽

Significant Relationships ◽

Residual Phase ◽

Acute Group ◽

Basic Language ◽

Processing Program ◽

Operational Systems

SummaryThe concordance and degree of overlap between 13 diagnostic systems for schizophrenia, including the five European systems of Berner, Bleuler, Langfeldt, Pull and Schneider, were evaluated in a cross-sectional study (N = 51) taking the phase of illness (acute or residual) into account. The diagnostic assessments were processed by computer using a 183-item standardised checklist and a data-processing program in GW-Basic language. The inter-rater reliability, as assessed by Kappa coefficient, was good to excellent for each diagnostic system established by this method (K from 0.5 to 1). When comparing the concordance between pairs of 13 diagnostic systems for schizophrenia in acute and residual phase groups, results showed that only two significant relationships were not influenced by the phase of illness (Carpenter x RDC; Catego x Schneider), while 24 were. These included only two relationships in the acute group (Carpenter Catego; Carpenter Schneider) and 22 links between pairs of systems in the residual group. In the acute group, no diagnosis of schizophrenia, including duration criteria such as those of DSM III-R, Feighner, Langfeldt, Pull and RDC, was linked to other systems. In the residual group, the operational systems such as Catego, DSM III-R, Feighner, Newhaven, Pull and RDC had more than five relationships with the other systems whereas the non-operational systems of Bleuler, ICD9, Langfeldt and Schneider had less than four relationships with the others. Except Pull's criteria, the European diagnostic systems, in particular Berner's and Bleuler's, seemed to differ from the others because of the few relationships displayed. The results underline the importance of taking the phase of illness into account when comparing between studies utilizing different diagnostic systems for schizophrenia. They also show the relationships between European and international diagnostic systems, insufficiently established so far.

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