scholarly journals Reusable Component Model Development Approach for Parallel and Distributed Simulation

2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Feng Zhu ◽  
Yiping Yao ◽  
Huilong Chen ◽  
Feng Yao
Keyword(s):  
Distributed Simulation ◽  
Model Development ◽  
Component Model ◽  
Model Framework ◽  
Domain Experts ◽  
Reusable Component ◽  
Parallel And Distributed Simulation ◽  
Development Approach ◽  
Two Phases ◽  
Component Models

Model reuse is a key issue to be resolved in parallel and distributed simulation at present. However, component models built by different domain experts usually have diversiform interfaces, couple tightly, and bind with simulation platforms closely. As a result, they are difficult to be reused across different simulation platforms and applications. To address the problem, this paper first proposed a reusable component model framework. Based on this framework, then our reusable model development approach is elaborated, which contains two phases: (1) domain experts create simulation computational modules observing three principles to achieve their independence; (2) model developer encapsulates these simulation computational modules with six standard service interfaces to improve their reusability. The case study of a radar model indicates that the model developed using our approach has good reusability and it is easy to be used in different simulation platforms and applications.

scholarly journals Parallel Network Simulation With OMNeT++

2009 ◽  
Author(s):  
András Varga ◽  
Ahmet Y. Şekercioğlu Şekercioğlu
Keyword(s):  
Communication Networks ◽  
Large Scale ◽  
Distributed Simulation ◽  
Discrete Event ◽  
Rare Event ◽  
Telecommunication Networks ◽  
Event Simulation ◽  
Parallel And Distributed Simulation ◽  
Simulation Protocol ◽  
Parallel Network

This paper reports a new parallel and distributed simulation architecture for OMNeT++, an open-source discrete event simulation environment. The primary application area of OMNeT++ is the simulation of communication networks. Support for a conservative PDES protocol (the Null Message Algorithm) and the relatively novel Ideal Simulation Protocol has been implemented.Placeholder modules, a novel way of distributing the model over several logical processes (LPs) is presented. The OMNeT++ PDES implementation has a modular and extensible architecture, allowing new synchronization protocols and new communication mechanisms to be added easily, which makes it an attractive platform for PDES research, too. We intend touse this framework to harness the computational capacity of highperformance cluster computersfor modeling very large scale telecommunication networks to investigate protocol performance and rare event failure scenarios.

scholarly journals A Survey of Domain Knowledge Elicitation in Applied Machine Learning

2021 ◽  
Vol 5 (12) ◽  
pp. 73
Author(s):  
Daniel Kerrigan ◽  
Jessica Hullman ◽  
Enrico Bertini
Keyword(s):  
Machine Learning ◽  
Domain Knowledge ◽  
Development Process ◽  
Model Development ◽  
Knowledge Elicitation ◽  
Future Directions ◽  
Domain Experts ◽  
Applied Machine Learning ◽  
Elicitation Process ◽  
Model Development Process

Eliciting knowledge from domain experts can play an important role throughout the machine learning process, from correctly specifying the task to evaluating model results. However, knowledge elicitation is also fraught with challenges. In this work, we consider why and how machine learning researchers elicit knowledge from experts in the model development process. We develop a taxonomy to characterize elicitation approaches according to the elicitation goal, elicitation target, elicitation process, and use of elicited knowledge. We analyze the elicitation trends observed in 28 papers with this taxonomy and identify opportunities for adding rigor to these elicitation approaches. We suggest future directions for research in elicitation for machine learning by highlighting avenues for further exploration and drawing on what we can learn from elicitation research in other fields.

Does the Signal-to-Noise Paradox Exist in Subseasonal Predictions?

2021 ◽  
Author(s):  
Wei Zhang ◽  
Baoqiang Xiang ◽  
Ben Kirtman ◽  
Emily Becker
Keyword(s):  
Signal To Noise Ratio ◽  
Current Model ◽  
Model Development ◽  
Coupled Model ◽  
Seasonal Prediction ◽  
Signal To Noise ◽  
Model Framework ◽  
Noise Ratio ◽  
Decadal Climate ◽  
New Generation

<p>One of the emerging topics in climate prediction is the issue of the so-called “signal-to-noise paradox”, characterized by too small signal-to-noise ratio in current model predictions that cannot reproduce the realistic signal. Recent studies have suggested that seasonal-to-decadal climate can be more predictable than ever expected due to the paradox. But no studies, to the best of our knowledge, have been focused on whether the signal-to-noise paradox exists in subseasonal predictions. The present study seeks to address the existence of the paradox in subseasonal predictions based on (i) coupled model simulations participating in phase 5 and phase 6 of the Coupled Model Intercomparison Project (CMIP5 and CMIP6, respectively), and (ii) subseasonal hindcast outputs from the Subseasonal Experiment (SubX) and the Subseasonal-to-Seasonal Prediction (S2S) projects. Of particular interest is the possible existence of the paradox in the new generation of GFDL SPEAR model, through the diagnosis of which may help identify potential issues in the new forecast system to guide future model development and initialization. Here we investigate the paradox issue using two methods: the ratio of predictable component defined as the ratio of predictable component in the real world to the signal-to-noise ratio in models and the persistence/dispersion characteristics estimated from a Markov model framework. The preliminary results suggest a potentially widespread occurrence of the signal-to-noise paradox in subseasonal predictions, further implying some room for improvement in future ensemble-based subseasonal predictions.</p>

scholarly journals Validity of two-component models for estimating body fat of black men

2001 ◽  
Vol 90 (2) ◽  
pp. 649-656 ◽  
Author(s):  
Dale R. Wagner ◽  
Vivian H. Heyward
Keyword(s):  
Black Men ◽  
Body Fat ◽  
Predictive Accuracy ◽  
Component Model ◽  
Suitable Alternative ◽  
Heterogeneous Sample ◽  
Four Component Model ◽  
Two Component ◽  
Model Conversion ◽  
Component Models

Commonly used two-component model conversion formulas that estimate relative body fat (%BF) from body density (Db) were cross-validated on a heterogeneous sample of black men ( n = 30; age = 19–45 yr). A four-component model was used to obtain criterion measures of %BF, and linear regression and analysis of individual residual scores were conducted to assess the predictive accuracy of the formulas under investigation. The two-component formula commonly used to estimate %BF of black men (Schutte JE, Townsend EJ, Hugg J, Shoup RF, Malina RM, and Blomqvist CG. J Appl Physiol 56: 1647–1649, 1984) significantly ( P ≤ 0.01) and systematically (87% of sample) overestimated %BF (−1.28%); thus we developed the following two-component Db conversion formula: %BF = [(4.858/Db) − 4.394] × 100. Because our formula was derived from a four-component model and a larger, more heterogeneous sample than the commonly used two-component formula, we recommend using it to convert Db to %BF for black men. Additionally, there was good agreement between dual-energy X-ray absorptiometry and the four-component model, making this a suitable alternative for estimating the %BF of black men.

Five-component model validation of reference, laboratory and field methods of body composition assessment

2020 ◽  
pp. 1-14
Author(s):  
Grant M. Tinsley
Keyword(s):  
Body Composition ◽  
Total Error ◽  
Component Model ◽  
Coefficient Of Determination ◽  
Body Volume ◽  
Reference Laboratory ◽  
Equivalence Testing ◽  
Body Composition Assessment ◽  
Field Methods ◽  
Component Models

Abstract This study reports the validity of body fat percentage (BF%) estimates from several commonly employed techniques as compared with a five-component (5C) model criterion. Healthy adults (n 170) were assessed by dual-energy X-ray absorptiometry (DXA), air displacement plethysmography (ADP), multiple bioimpedance techniques and optical scanning. Output was also used to produce a criterion 5C model, multiple variants of three- and four-component models (3C; 4C) and anthropometry-based BF% estimates. Linear regression, Bland–Altman analysis and equivalence testing were performed alongside evaluation of the constant error (CE), total error (TE), se of the estimate (SEE) and coefficient of determination (R2). The major findings were (1) differences between 5C, 4C and 3C models utilising the same body volume (BV) and total body water (TBW) estimates are negligible (CE ≤ 0·2 %; SEE < 0·5 %; TE ≤ 0·5 %; R2 1·00; 95 % limits of agreement (LOA) ≤ 0·9 %); (2) moderate errors from alternate TBW or BV estimates in multi-component models were observed (CE ≤ 1·3 %; SEE ≤ 2·1 %; TE ≤ 2·2 %; R2 ≥ 0·95; 95 % LOA ≤ 4·2 %); (3) small differences between alternate DXA (i.e. tissue v. region) and ADP (i.e. Siri v. Brozek equations) estimates were observed, and both techniques generally performed well (CE < 3·0 %; SEE ≤ 2·3 %; TE ≤ 3·6 %; R2 ≥ 0·88; 95 % LOA ≤ 4·8 %); (4) bioimpedance technologies performed well but exhibited larger individual-level errors (CE < 1·0 %; SEE ≤ 3·1 %; TE ≤ 3·3 %; R2 ≥ 0·94; 95 % LOA ≤ 6·2 %) and (5) anthropometric equations generally performed poorly (CE 0·6– 5·7 %; SEE ≤ 5·1 %; TE ≤ 7·4 %; R2 ≥ 0·67; 95 % LOA ≤ 10·6 %). Collectively, the data presented in this manuscript can aid researchers and clinicians in selecting an appropriate body composition assessment method and understanding the associated errors when compared with a reference multi-component model.

scholarly journals Essentials of the macroscopic-microscopic folded-Yukawa approach and examples of its record in providing nuclear-structure data for simulations

2018 ◽  
Vol 184 ◽  
pp. 01013
Author(s):  
Peter Möller
Keyword(s):  
Nuclear Structure ◽  
Ground State ◽  
Neutron Emission ◽  
Level Structure ◽  
Model Development ◽  
State Level ◽  
Heavy Ion ◽  
Macroscopic Model ◽  
Model Description ◽  
Model Framework

The macroscopic-microscopic model based on the folded-Yukawa singleparticle potential and a “finite-range” macroscopic model is probably the approach that has provided the most reliable predictions of a large number of nuclear-structure properties for all nuclei between the proton and neutron drip lines. I will describe some basic features of the model and the development philosophy that may be the reason for its success. Examples of quantities modeled within the same model framework are, nuclear masses, ground-state level structure, including spins, ground-state shapes, fission barriers, heavy-ion fusion barriers, sub-barrier fusion cross sections, β-decay half-lives and delayed neutron emission probabilities, shape coexistence, and α-decay Qα energies to name a few. I will show how well it predicted various properties measured after published results. Rather than giving an incomplete model description here I will give a timeline of model development and provide references to typical applications and references that are sufficiently complete that several individuals have written computer codes based on these references, codes whose results have excellent agreement with ours.

LOAD BALANCING FOR PARALLEL PCS NETWORK SIMULATIONS

2000 ◽  
Vol 01 (03) ◽  
pp. 173-193 ◽  
Author(s):  
AZZEDINE BOUKERCHE
Keyword(s):  
Load Balancing ◽  
Distributed Simulation ◽  
Simulation Experiments ◽  
Time Warp ◽  
Conservative Scheme ◽  
Simulation Techniques ◽  
Parallel And Distributed Simulation ◽  
Pcs Networks ◽  
Network Simulations ◽  
Stage 1

Parallel and distributed simulation techniques have been investigated in a number of studies to decrease the execution times of PCS network simulations. In this paper, we consider distributed simulation of PCS models using a two-state PCS simulation testbed which makes use of a conservative scheme at Stage 1, and of Time Warp at Stage 2, and focus upon the load balancing issue. We investigate and study several load balancing schemes for TDMA systems. Extensive simulation experiments were conducted on a cluster of workstations using a real suburban area serviced by an FCA-based PCS networks. Our results indicate clearly that careful load balancing scheme is important in the success of the PCS simulation model.

Sign in / Sign up

Export Citation Format

Share Document