연구에서 모형의 분류와 검정모형의 개발

권순달(Soon-Dal Kwon) 한국교육학회 2023 敎育學硏究 Vol.61 No.1

본 연구는 연구에서 널리 활용되고 있는 모형을 분류하고, 다양한 모형을 이해하는 데 있다. 이를 위하여 모형의 개념을 재정의하고, 모형의 분류 준거를 분석하고, 새로운 모형 분류 기준을 제시하였다. 본 연구에서 모형이란, “연구자의 이론, 철학, 신념 등을 반영한 것으로 논리적으로 제안된 그 무엇이다”라고 정의하였다. 여러 학문 분야의 모형 분류 준거가 다양하고, 대부분 이분화된 준거를 사용하였다. 이에 따라 연구자도 검정가능성을 모형의 분류 준거로 하여 검정모형과 비검정모형으로 분류하였다. 이 준거에 의하면 검정모형 제안자들은 데이터를 사용하여 자신이 개발한 모형을 검정하여 제시하고 있다. 그러나 비검정모형은 엄격한 검정이 이루어지 않고 제안되었다고 할 수 있다. 그리고 비검정모형들은 개발과정의 일반적인 절차를 따르지 않고 있다. 이러한 이유에서 검정모형 개발 5단계를 제안하였다. 물론 연구자가 제안한 검정 모형 개발 5단계는 하나의 ‘’비검정 모형‘이라고 할 수 있다. 검정모형과 비검정 모형의 개발은 누구나 할 수 있지만, 비검정모형이 아닌, 검정모형은 논리적인 절차에 따라 개발되고 검정될 필요가 있다. The purpose for this study is to classify models widely used in research and to understand various models. To this end, the concept of the model was redefined, the classification criteria of models were analyzed, and new model classification criteria were presented. In this study, a model is defined as “something that is logically proposed as a reflection of the researcher's theory, philosophy, beliefs, etc.”. There are various criteria for classification of models in many academic fields, but most of them use the dichotomous method. Accordingly, this researcher classified all models into a tested model and the non-tested model based on the test feasibility. The tested model refers to a model tested by the proposers using data. On the other side, nnn-tested model is a model proposed without rigorous testing. Tested models require rigorous development procedures, but non-tested models do not require such procedures. For this reason, five stages of test model development were proposed. Of course, the 5 stages of test model development proposed by the researcher can be said to be a ‘non-testing model’. Anyone can develop a model whether it is a test model or a non-test model, but a test model, not a non-test model, needs to be developed and tested strictly.

모델 기반 평가 방법을 이용한 지능형자동차 기능의 평가 자동화에 관한 연구

한갑수(Kab-Su Han),강호준(Ho-joon Kang),정승환(Seung-Hwan Chung),권성진(Seong-Jin Kwon),이봉현(Bong-Hyun Lee) 한국자동차공학회 2013 한국자동차공학회 부문종합 학술대회 Vol.2013 No.5

Model-based testing is a kind of black box testing that test suites are derived from behavioral model of SUT through test case generation and execute test suites automatically by model-based testing tool. A model-based testing tool uses various test generation algorithms and criteria to generate test cases. The behavioral model of SUT has to be concise enough to write and validate. Also, be precise enough to specify the behavior which is to be tested. Test cases can be generated automatically from the model and test engineer can control testing and maintain test cases easily. The abstract test cases have to be transformed into executable test cases with more specific information about SUT. Test selection criteria and lots of test generation strategies are commonly used in model-based testing. The complementary of these are key point of model-based testing. For this purpose, several state-based models are developed and test suites which derived from various test generation strategies, especially focused on transition coverage, are performed. Also, testing performances are discussed for test coverage of each test suite.

A Comparison Among Neo-Hookean Model, Mooney-Rivlin Model, and Ogden Model for Chloroprene Rubber

김범근,이성범,이재원,조세현,박형민,염상훈,박성한 한국정밀공학회 2012 International Journal of Precision Engineering and Vol. No.

Neo-Hookean model and Mooney-Rivlin model are hyperelastic material models where the strain energy density function is made from invariants of the left Cauchy-Green deformation tensor. Even though Ogden model is a hyperelastic material model, its strain energy density function is expressed by principal stretch ratio. These three models have been widely used in industries. Recently, Ogden model, especially Ogden 3rd model, shows better agreement with the test data than others. In spite of the limitations to describe particular stress states, it is known that reasonable results using these models can be obtained for various structural components. In this research, three kinds of models are considered for Chloroprene rubber. Three kinds of tests (Uniaxial tension test, Biaxial tension test, and Planar shear test) are performed for Chloroprene specimen and through four kinds of test combinations (Uni+Bi, Uni+Pl, Bi+Pl, Uni+Bi+Pl), numerical simulations are carried out for Neo-Hookean model, Mooney-Rivlin model, and Ogden model. It is shown that Mooney-Rivlin model and Ogden model can be used for Chloroprene Rubber in the specific ranges for Isotropic Hyperelastic model.

Validation of a 750 kW semi-submersible floating offshore wind turbine numerical model with model test data, part II: Model-II

Kim, Junbae,Shin, Hyunkyoung The Society of Naval Architects of Korea 2020 International Journal of Naval Architecture and Oc Vol.12 No.1

Floating Offshore Wind Turbines (FOWT) installed in the deep sea regions where stable and strong wind flows are abundant would have significantly improved energy production capacity. When designing FOWT, it is essential to understand the stability and motion performance of the floater. Water tank model tests are required to evaluate these aspects of performance. This paper describes a model test and numerical simulation for a 750-kW semi-submersible platform wind turbine model-II. In the previous model test, the 750-kW FOWT model-I suffered slamming phenomena from extreme wave conditions. Because of that, the platform freeboard of model-II was increased to mitigate the slamming load on the platform deck structure in extreme conditions. Also, the model-I pitch Response Amplitude Operators (RAO) of simulation had strong responses to the natural frequency region. Thus, the hub height of model-II was decreased to reduce the pitch resonance responses from the low-frequency response of the system. Like the model-I, 750-kW FOWT model-II was built with a 1/40 scale ratio. Furthermore, the experiments to evaluate the performance characteristics of the model-II wind turbine were executed at the same location and in the same environment conditions as were those of model-I. These tests included a free decay test, and tests of regular and irregular wave conditions. Both the experimental and simulation conditions considered the blade rotating effect due to the wind. The results of the model tests were compared with the numerical simulations of the FOWT using FAST (Fatigue, Aerodynamics, Structures, and Turbulence) code from the National Renewable Energy Laboratory (NREL).

Validation of a 750 kW semi-submersible floating offshore wind turbine numerical model with model test data, part II: Model-II

Kim, Junbae,Shin, Hyunkyoung The Society of Naval Architects of Korea 2020 International Journal of Naval Architecture and Oc Vol.12 No.-

Floating Offshore Wind Turbines (FOWT) installed in the deep sea regions where stable and strong wind flows are abundant would have significantly improved energy production capacity. When designing FOWT, it is essential to understand the stability and motion performance of the floater. Water tank model tests are required to evaluate these aspects of performance. This paper describes a model test and numerical simulation for a 750-kW semi-submersible platform wind turbine model-II. In the previous model test, the 750-kW FOWT model-I suffered slamming phenomena from extreme wave conditions. Because of that, the platform freeboard of model-II was increased to mitigate the slamming load on the platform deck structure in extreme conditions. Also, the model-I pitch Response Amplitude Operators (RAO) of simulation had strong responses to the natural frequency region. Thus, the hub height of model-II was decreased to reduce the pitch resonance responses from the low-frequency response of the system. Like the model-I, 750-kW FOWT model-II was built with a 1/40 scale ratio. Furthermore, the experiments to evaluate the performance characteristics of the model-II wind turbine were executed at the same location and in the same environment conditions as were those of model-I. These tests included a free decay test, and tests of regular and irregular wave conditions. Both the experimental and simulation conditions considered the blade rotating effect due to the wind. The results of the model tests were compared with the numerical simulations of the FOWT using FAST (Fatigue, Aerodynamics, Structures, and Turbulence) code from the National Renewable Energy Laboratory (NREL).

휴리스틱 입력 분석을 이용한 RRT 기반의 Simulink/Stateflow 모델 테스트 케이스 생성 기법

박현상 ( Hyeon Sang Park ),최경희 ( Kyung Hee Choi ),정기현 ( Ki Hyun Chung ) 한국정보처리학회 2013 정보처리학회논문지. 소프트웨어 및 데이터 공학 Vol.2 No.12

본 논문은 Simulink/Stateflow 모델 기반의 테스트 케이스를 자동으로 생성하기 위하여, 휴리스틱 입력 분석을 이용한 Rapidly-exploring Random Tree(RRT) 기법을 제안한다. RRT는 모델 기반 블랙박스 테스트 케이스 생성 시 반드시 해결해야 되는 도달 가능성 문제를 효율적으로 해결할 수 있는 방법이지만, 모델의 내부 상태와 테스트 목표를 고려하지 않고 무작위로 모델의 입력을 생성하기 때문에 테스트 케이스 생 성 효율이 떨어지는 단점이 있다. 제안하는 기법에서는 RRT를 확장해나갈 때 필요한 입력을, 모델의 현재 상태에서 만족 할 수 있는 테스트 목표를 분석하고 이를 달성할 수 있는 모델의 입력을 분석 결과에 따라 휴리스틱하게 결정함으로써, RRT의 장점을 보존하면서, 테스트 케이스 생성 효율을 높일 수 있다. 제안된 기법은 자동차에 사용되는 실 부품 ECU의 Simulink/Stateflow 모델을 대상으로 한 실험을 통해 성능이 평가되었으며, 기존 RRT와 비교하여 테스트 케이스 생성 효율이 높은 것을 보였다. This paper proposes a modified RRT (Rapidly exploring Random Tree) algorithm utilizing a heuristic input analysis and suggests a test case generation method from Simulink/Stateflow model using the proposed RRT algorithm. Though the typical RRT algorithm is an efficient method to solve the reachability problem to definitely be resolved for generating test cases of model in a black box manner, it has a drawback, an inefficiency of test case generation that comes from generating random inputs without considering the internal states and the test targets of model. The proposed test case generation method increases efficiency of test case generation by analyzing the test targets to be satisfied at the current state and heuristically deciding the inputs of model based on the analysis during expanding an RRT, while maintaining the merit of RRT algorithm. The proposed method is evaluated with the models of ECUs embedded in a commercial passenger`s car. The performance is compared with that of the typical RRT algorithm.

이산 사건 시스템 명세 시뮬레이션에서 원자 모델의 빠른 검증을 위한 스크립트 기반 테스트 시스템

남수만(Su-Man Nam) 한국컴퓨터정보학회 2022 韓國컴퓨터情報學會論文誌 Vol.27 No.5

모델링 및 시뮬레이션은 목표 시스템의 동작 검증, 성능 분석, 운용 최적화, 예측을 위해 사용되는 기술이다. 이 기술의 대표적인 이산사건 시스템 명세(DEVS)는 모델들을 엄격한 형식론으로 정의하고 모델 간의 구조를 계층화한다. 이 DEVS 모델들의 원자 모델은 목표와 다른 의도로 동작하게 될 경우 시뮬레이션은 잘못된 의사결정으로 이어질 수 있다. 그럼에도 대부분 DEVS 시스템은 모델 테스트의 부재 또는 수동 테스트 환경으로 제공하여 개발자가 모델을 검증하는 데 오랜 시간이 소비된다. 본 논문에서는 파이썬 기반 DEVS에서 정확하고 빠른 원자 모델의 검증을 위해 스크립트 기반 테스트 시스템을 제안한다. 제안 테스트 시스템은 기존 방식인 수동 테스트와 새로운 방식인 스크립트 기반 테스트를 둘 다 사용한다. 우리 시스템의 실험 결과, 제안 테스트 방식은 스크립트를 10번 연속 실행 시 24ms 이내에 실행되었다. 그리하여 제안 시스템은 스크립트 기반 테스트를 사용해서 빠른 원자 모델 검증 시간을 보장하고, 테스트 스크립트의 재사용성을 향상한다. 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.

MODEL-BASED AUTOMATIC TEST CASE GENERATION FOR AUTOMOTIVE EMBEDDED SOFTWARE TESTING

Ki-Wook Shin,Dong-Jin Lim 한국자동차공학회 2018 International journal of automotive technology Vol.19 No.1

We propose a method to automatically generate software and hardware test cases from a UML model developed through a model-based development process. Where languages such as source-code languages are used within the model, input and expected values for each test case are generated using a custom parser. As a next step, unit test cases are combined to generate integration test cases using a bottom-up approach. Then these cases are converted into hardware test cases for approval testing of embedded systems, using XQuery and hardware mapping tables. We demonstrate this process by applying it to the power window switch module of a Hyundai Santa Fe vehicle. Our approach provides an automatic testing procedure for embedded systems developed by model-based methods, and generates test cases efficiently using a recombination of signals. In conclusion, our proposed method could help reduce the resources needed for test case generation from software to hardware.

수정 IWAN 모델을 이용한 사질토의 반복경화거동에 대한 연구 2 : 모델 검증

이진선,김동수,추연욱,윤종구 한국지진공학회 2003 한국지진공학회논문집 Vol.7 No.5

본 논문에서는 동반된 논문에서 제안된 수정 병렬 IWAN 모델의 적용성을 금강 모래와 토요라 모래를 대상으로 비틂전단실험을 수행하여 검증하였다. 두가지 사질토에 대해서 대칭 하중과 불규칙 하중을 반복 재하하여 실험을 수행하였다. 제안된 모델의 변수는 다양한 상대밀도와 구속압 조건하에서 대칭 반복하중을 재하하여 결정하였다. 시험 결과, 하중반복회수가 증가함에 따라 발생하는 사질토의 반복경화거동을 수정 병렬 IWAN 모델로 표현 가능하였으며, Pyke(1979)에 의해 제안된 불규칙 하중 형태를 이용한 실험결과를 실험 조건이 유사한 대칭 반복하중 재하실험 결과로 얻어진 모델 변수를 이용하여 예측한 결과 실험 결과와 잘 일치함을 알 수 있었다. In order to verify the applicability of the developed modified parallel IWAN model. two types of cyclic torsional shear tests were performed using Kum-Kang and Toyoura sands. One was a symmetric-limit loading test and the other was an irregular loading test. Model parameters were derived from the symmetric limit loading tests at various relative densities and confining pressures. The modified parallel IWAN model can predict the cyclic hardening behavior of sands very well as increasing loading cycles in the symmetric-limit tests. Irregular loading tests were performed using the loading shape suggested by Pyke(1979). Cyclic behaviors under irregular loading were simulated using model parameters derived from symmetric limit loading test results of similar loading conditions. The predicted cyclic hardening behaviors under irregular loading matched well with experimental results and the applicability of the proposed model was verified.

추계학적 지진동모델에 기반한 2D Q 토모그래피 수치모델 역산

연관희 ( Kwan Hee Yun ),서정희 ( Jung Hee Suh ) 한국지구물리탐사학회 2007 지구물리와 물리탐사 Vol.10 No.3

한반도 남부지역의 세부적인 지진파 감쇠특성 규명을 위해, 기존에는 적용이 불가능하였던 Q 토모그래피 역산을 위한 사전 수치검증 연구를 수행하였다. 특히 강지진동모사를 위해 일반적으로 사용되고 있는 추계학적 점지진원 지진동모델(stochastic point-source ground-motion model; Boore, 2003)에서 사용되는 Q 값에 대한 2차원(2D; 2 Dimensional) 토모그래피 역산을 시도함으로써 역산 결과가 강지진동모사에 직접 활용될 수 있도록 하였다. 수치검증 방법으로는 Q 토모그래피 checkerboard 시험방법이 사용되었는데, 이를 위해 광역 단일 Q 모델의 추계학적 지진동모델 파라미터 역산결과의 지진원과 부지효과 모델 파라미터 값을 이용해서 관측자료와 지진규모-거리-주파수-오차 분포가 동일한 스펙트럼 합성자료를 생성하였다. 수치검증을 위한 Q 블록 격자의 총 개수는 75개(내륙지역=69개(약 35 × 44 km2의 격자크기); 해양지역=6개)로 설정하였으며, Qofη 함수형태의 Q 블록 값은 Qo=100, 500, η=0.0 ~ 1.0의 분포를 갖도록 하고, 파선의 깊이는 별도로 고려하지 않았다. 스펙트럼 합성자료 생성에 이용된 모델파라미터의 정해와 모델파라미터의 역산결과를 비교 하기 위한 checkerboard 수치검증은 3단계에 걸쳐 수행되었는데, 1단계는 블록별 Q의 초기값 추정 단계이며, 2단계는 관측소별 부지증폭함수를 추정하는 단계, 마지막 3단계에서는 최종적인 Q를 도출하는 단계이다. 관측소별 부지증폭함수의 초기 추정값으로는 기 분류된 관측소 등급에 대한 평균 부지증폭함수(연관희, 서정희, 2007)가 사용되었으며, 3단계의 checkerboard 수치검증 결과 최종적으로 추정된 부지효과 모델에는 오차가 발생하였으나 블록별 Q의 정해는 만족할 정도로 추정할 수 있었다. To identify the detailed attenuation structure in the southern Korean Peninsula, a numerical test was conducted for the Q tomography inversion to be applied to the accumulated dataset until 2005. In particular, the stochastic point-source ground-motion model (STGM model; Boore, 2003) was adopted for the 2D Q tomography inversion for direct application to simulating the strong ground-motion. Simultaneous inversion of the STGM model parameters with a regional single Q model was performed to evaluate the source and site effects which were necessary to generate an artificial dataset for the numerical test. The artificial dataset consists of simulated Fourier spectra that resemble the real data in the magnitude-distance-frequency-error distribution except replacement of the regional single Q model with a checkerboard type of high and low values of laterally varying Q models. The total number of Q blocks used for the checkerboard test was 75 (grid size of 35 × 44 km2 for Q blocks); Q functional form of Qofη (Qo=100 or 500, 0.0 < η < 1.0) was assigned to each Q block for the checkerboard test. The checkerboard test has been implemented in three steps. At the first step, the initial values of Q-values for 75 blocks were estimated. At the second step, the site amplification function was estimated by using the initial guess of A(f) which is the mean site amplification functions (Yun and Suh, 2007) for the site class. The last step is to invert the tomographic Q-values of 75 blocks based on the results of the first and second steps. As a result of the checkerboard test, it was demonstrated that Q-values could be robustly estimated by using the 2D Q tomography inversion method even in the presence of perturbed source and site effects from the true input model.