• Coupled systems mechanics
• /
• v.4 no.1
• /
• pp.67-98
• /
• 2015

Numerical prediction of dynamic behavior of fully coupled saturated porous media is of great importance in many engineering problems. Specifically, static and dynamic response of soils - porous media with pores filled with fluid, such as air, water, etc. - can only be modeled properly using fully coupled approaches. Modeling and simulation of static and dynamic behavior of soils require significant Verification and Validation (V&V) procedures in order to build credibility and increase confidence in numerical results. By definition, Verification is essentially a mathematics issue and it provides evidence that the model is solved correctly, while Validation, being a physics issue, provides evidence that the right model is solved. This paper focuses on Verification procedure for fully coupled modeling and simulation of porous media. Therefore, a complete Solution Verification suite has been developed consisting of analytical solutions for both static and dynamic problems of porous media, in time domain. Verification for fully coupled modeling and simulation of porous media has been performed through comparison of the numerical solutions with the analytical ones. Modeling and simulation is based on the so called, u-p-U formulation. Of particular interest are numerical dispersion effects which determine the level of numerical accuracy. These effects are investigated in detail, in an effort to suggest a compromise between numerical error and computational cost.

• Journal of the Korean Society of Industry Convergence
• /
• v.22 no.6
• /
• pp.689-702
• /
• 2019

This paper deals with the verification of the functions about mining robot, which is the system for developing deep seabed resources by applying V&V(verification and validation). In order to overcome water pressure of 500 bar and to travel on soft ground, and to operate in deep sea environment with bad conditions, it is necessary to develop a robot that can satisfy various deepsea conditions. A mining robot has been developed based on simulation based design and Multidisciplinary design optimization. In order to verify the developed robot, lab test and real sea test should be performed for various marine environment conditions. There are too many requirements to consider, such as space, time, cost, personnel, and environment to do performance test. So it is costly and time consuming for developing robot. In order to solve this problems, V&V technique was applied to mining robot. The stages of mining robot design, fabrication and commission were verified.

• Journal of the Korea Society of Computer and Information
• /
• v.27 no.5
• /
• pp.101-107
• /
• 2022

Modeling and simulation is a technique used for operational verification, performance analysis, operational optimization, and prediction of target systems. Discrete Event System Specification (DEVS) of this representative technology defines models with a strict formalism and stratifies the structures between the models. When the atomic DEVS models operate with an intention different the target system, the simulation may lead to erroneous decision-making. However, most DEVS systems have the exclusion of the model test or provision of the manual test, so developers spend a lot of time verifying the atomic models. In this paper, we propose a script-based automated test system for accurate and fast validation of atomic models in Python-based DEVS. The proposed system uses both the existing method of manual testing and the new method of the script-based testing. As Experimental results in our system, the script-based test method was executed within 24 millisecond when the script was executed 10 times consecutively. Thus, the proposed system guarantees a fast verification time of the atomic models in our script-based test and improves the reusability of the test script.

• The Magazine of the IEIE
• /
• v.30 no.9
• /
• pp.1002-1011
• /
• 2003

In this paper, we introduce an integrated SoC front-end design & verification environment which can be practically used in the embedded 32-bit processor-core SoC VLSI design. Our introduced SoC design & verification environment integrates two most important flows, such as the RTL power estimation and code coverage analysis, with the functional verification (chip validation) flow which is used in the conventional simulation-based design. For this, we developed two simulation-based inhouse tools, RTL power estimator and code coverage analyzer, and used them to adopt them to our RTL design and to increase the design quality of that. Our integrated design environment also includes basic design and verification flows such as the gate-level functional verification with back annotation information and test vector capture & replay environment.

• Journal of the Korean Society of Systems Engineering
• /
• v.19 no.1
• /
• pp.44-55
• /
• 2023

The defense M&S system, which has been classified as a weapon system between requirements determination and project implementation, is being developed by applying the weapon system development procedure of the Defense Acquisition Program Administration. The M&S system abstracts and models the real world to suit the intended use and proceeds with the process of developing it as a software-oriented system. Overseas, the conceptual model development stage is staged before entering the design stage after the requirements analysis. In addition, each step includes verification and validation processes. In Korea, while establishing and applying the weapon system development procedure based on the SE process, the M&S system is also applied in the same way as the general weapon system, limiting appropriate development outputs and verification and validation. In this study, the system development procedure of the M&S system is established and presented based on the relevant standards and SE process of developed countries.

• Journal of Ocean Engineering and Technology
• /
• v.27 no.1
• /
• pp.24-30
• /
• 2013

The Korea Navy has been making constant efforts to apply M&S (modeling and simulation) to naval ship development, and the generalization of M&S for ship development is a trend. M&S for ship design is used for the V&V (verification and validation) of its design and operation, including design verification and ergonomic design that considers the crew using the Naval Ship Product Model. In addition, many parts of this M&S are repeatedly accomplished regardless of the kinds of ships. This study aims to standardize M&S, which repeatedly applies similar verifications for operation scenarios. A congestion assessment simulation for the major spaces of ships was the subject of the standardization based on the leading research results of various researchers, and a simulation automation solution was suggested. An information model using XML was proposed through the simulation automation concept, and a prototype system based on it was implemented. The usability was shown through a case study that verified the operability performance of the crew messroom.

• Journal of the Korea Society for Simulation
• /
• v.27 no.1
• /
• pp.25-32
• /
• 2018

This paper presents an efficient software reliability testing method for the model based auto-generated code and reify a dynamic test procedure. The benefits of executing the model-based each static/dynamic reliability test before the code-based static/dynamic reliability test are described. Also, The correlations of code/model based reliability test are demonstrated by using model testing tool, Model Advisor and Verification and Validation, and the code testing tool, PolySpace and LDRA. The result of reliability test is indicated in this paper.

• Journal of the Korea Safety Management & Science
• /
• v.16 no.4
• /
• pp.123-131
• /
• 2014

Modern weapon systems are getting more complex in terms of the functionality and also the conditions on the environment and range in which they are deployed and used. Therefore, many development programs can easily be exposed to a variety of risks, resulting in delayed schedules and cost overrun. As such, effective means are necessary to keep the defence budget at an affordable level while competitive edges on technological aspects are retained. As one way to meet those need, modeling and simulation (M&S) methods have widely been used, particularly in the test and evaluation (T&E) process for weapon systems development. The result of M&S-based systems development should be evaluated by the verification, validation & accreditation (VV&A) process to assure keeping reliability at a desired level. On the other hand, due to the explosiveness, the weapons systems development naturally requires to consider safety issues in both the T&E and operational periods. The purpose of this paper is to improve the VV&A process by reflecting the safety requirements therein. To do so, the VV&A process has been analyzed and graphically modeled first and then safety elements have been incorporated effectively. The use of the improved process in the war ships development has also been discussed. Based on the process proposed and the consequent database constructed, the target system can be expected to benefit from reducing development risks while assuring systems safety.

• Journal of Korean Society on Water Environment
• /
• v.28 no.6
• /
• pp.833-842
• /
• 2012

In this study Window interface to Hydrological Simulation Program-FORTRAN (HSPF) developed by the United States Environmental Protection Agency (EPA) was applied to the upstream of Namgang watershed to estimate its applicability for estimating Delivery Ratio (DR) of water pollutants for Total Maximum Daily Load (TMDL). BASINS/HSPF which is selected in this study, is found to be appropriate for simulation of daily flow and water quality in target basins. DR was estimated utilizing discharge loads of unobserved sub-basin and delivery load of unobserved locations obtained not by actual evaluation but by simulation through validation and verification. Annual average DR of BOD, TN and TP were 0.97 ~ 1.50, 2.23 ~ 3.21, and 0.81 ~ 1.09 respectively. Net DR of dependent basins excluding influence of upstream basin was 1.50 ~ 1.70, 0.55 ~ 0.69, and 0.24 ~ 0.31, all of which are lower than those of independent basins area. Utilizing the model selected by this research, DR and Net DR of unobserved basins will be estimated, which will help determine priorities in management of basin areas.

• Nuclear Engineering and Technology
• /
• v.53 no.2
• /
• pp.455-465
• /
• 2021

The Molten Salt Reactor (MSR), one of the six advanced reactor types of the 4th generation nuclear energy systems, has many impressive features including economic advantages, inherent safety and nuclear non-proliferation. This paper introduces a system analysis code named TREND, which is developed and used for the steady and transient simulation of MSRs. The TREND code calculates the distributions of pressure, velocity and temperature of single-phase flows by solving the conservation equations of mass, momentum and energy, along with a fluid state equation. Heat structures coupled with the fluid dynamics model is sufficient to meet the demands of modeling MSR system-level thermal-hydraulics. The core power is based on the point reactor neutron kinetics model calculated by the typical Runge-Kutta method. An incremental PID controller is inserted to adjust the operation behaviors. The verification and validation of the TREND code have been carried out in two aspects: detailed code-to-code comparison with established thermal-hydraulic system codes such as RELAP5, and validation with the experimental data from MSRE and the CIET facility (the University of California, Berkeley's Compact Integral Effects Test facility).The results indicate that TREND can be used in analyzing the transient behaviors of MSRs and will be improved by validating with more experimental results with the support of SINAP.