• Journal of Welding and Joining
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• 제18권5호
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• pp.55-62
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• 2000

A metallurgical model for the phase transformation kinetics at Coarsened Grain Heat Affected Zone(CGHAZ) on the basis of Johnson-Mehl-Avrami equation(JMA equation) was proposed. In this model, the effect of prior austenite grain size on the transformation and the morphological changes of ferrite were considered. Isothermal dilatometer tests were performed to determine the effect of prior austenite grain size (AGS) on the austenite decomposition to ferrite and pearlite in a plain carbon steel. By comparing the calculated volume fraction with measured data, the reliability of the developed model was discussed.

• 지역사회간호학회지
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• 제8권2호
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• pp.277-288
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• 1997

The purpose of this study is to identify the behavioral subsystems of the obese adult and contribute to the utility of Johnson's Behavioral System Model. The subjects were 167 obese adults in out-patients clinics of 2 hospitals and health clinics for 4 companies. These data were collected by a structured questionnaire with 52 items from July 1 to Sep. 30, 1995. The instrument used for this study was modified from the DBSM -self reporting instrument (1983) and Grubbs(1980)'s. The reliability of this method was cronbach's ${\alpha}$=.8476 and the construct validity of it was accepted by using a factor analysis. These data were analyzed by frequency, percentage, mean, standard deviation, factor analysis, pearson's correlation coefficient, Kruskal-Wallis with an SPSS PC+ Program. The results of this study were as follows: 1. The 9 behavioral subsystems of the obese were indentified : sex-related, attachment-affiliative I(social), dependency, ingestive, eliminative, restorative, aggressive-protective, attachment-affiliative and II (familial), an achievement behavioral subsystem. 2. Out of 9 subsystems, the highest significant positive correlation between dependency and acheivement subsystem was found(r=.5357, p<.01), The next, attachment-affiliative I and attachment-affiliative II subsystem was correlated significantly (r=.4526, p<.01). Significant positive correlations among sex-related, achivement, attachment-affiliative I, II, dependency, restorative, and aggressive-protective subsystems were found. But, ingestive and eliminative subsystems were not correlated with the above seven subsystems significantly, only the positive correlation between the ingestive and eliminative subsystems was found. 3. The explained variance of the 9 subsystems was explained as 56.1% out of a total of one. The sex-related subsystem was the first factor explaining 16.3% of the total variance and then the next 8 factors which resulted in 39.8%. According to the results of this study, the suggestions were as follows: 1. In the nursing practice, nursing assessmentand intervention of the obese should be in cluded not only in ingestive and eliminative subsystems but also in sex-related, attachment-affiliative I, dependency, restorative, aggressive-protective, attachment -affiliative II, and achievement behavioral subsystem. 2. Concerning instruments, some items to measure the eliminative, dependency, and aggressive-protective behavioral subsystems with relatively reliability are needed. 3. Johnson's concept of a dependency subsystem should be clarified. 4. Correlation among the 7 subsystems, and the ingestive and eliminative subsystems should be clarified.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2009년도 춘계학술대회 논문집
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• pp.318-321
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• 2009

Transformation plasticity is that when a phase transformation of ferrous or non-ferrous alloys progresses even under an extremely small applied stress compared with a yield stress of the material, a permanent deformation occurs. One of widely accepted description for the transformation was proposed by Greenwood and Johnson [1]. Their description is based on an assumption that a weaker phase of an ideal plastic material could deform plastically to accommodate the externally applied stress and the internal stress caused by the volumetric change accompanying the phase transformation. In this study, an implicit finite element model was developed to simulate the deformation behavior of a low carbon steel during phase transformation. The finite element model was coupled with a phase field model, which could simulate the kinetics for ferrite to austenite transformation of the steel. The thermo-elasto-plastic constitutive equation for each phase was adopted to confirm the weaker phase yielding, which was proposed by Greenwood and Johnson [1]. From the simulation, the origin of the transformation plasticity was quantitatively discussed comparing with the other descriptions of it.

• 대한기계학회논문집A
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• 제37권1호
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• pp.67-75
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• 2013

핵연료 지지격자 소재로 사용되는 zircaloy-4의 유동응력을 Johnson-Cook 모델로 결정하고, 모델의 재료상수를 역 공학으로 도출했다. 변형률 항의 상수 A, B, n과 변형률 속도 항의 $\dot{\varepsilon}_0$은 인장시험을 통해 결정했다. 상수 C, m을 역 공학으로 도출하기 위해 슬롯밀링시험을 수행하고, 유한요소해석으로 모사했다. 실험과 해석으로 얻은 결과의 차이를 오차함수, 즉 최소화 대상 목적함수로 설정했고, 이 함수를 최소로 하는 C, m을 도출했다. 도출한 상수의 타당성을 검증하기 위해 상관계수를 살펴봤고, 전단시험과 해석을 수행해 교차 검증했다. 상관계수는 모든 조건에 대해 0.97이상으로 실험과 해석결과 사이에 강한 상관관계가 있음을 확인했다. 전단시험과 해석의 전단면 형상 및 최대하중을 비교하여 도출한 유동응력 모델이 타당함을 보였다.

• 한국산림과학회지
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• 제77권4호
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• pp.389-400
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• 1988

삼림경영계획(森林經營計劃) 모델들의 발전과정을 연대순으로 살펴 볼 때 독립적인 기능별계획(機能別計劃) 모델에서 종합적(綜合的)인 다목적이용계획(多目的利用計劃) 모델로 발전돼 가고 있으며 모델의 수학적구조(數學的構造)도 Model I 이나 Model II의 어느 한 쪽을 사용하는 단일구조(單一構造)에서 두 Model을 겸용하는 복수구조(複數構造)로 변해가고 있다. Model I과 Model II의 일반적 특성(特性), 계획상(計劃上) 차이(差異), 분석상(分析上)의 차이(差異)는 L.P.모델을 통하여 잘 설명할 수 있다. 여기에서는 공통적(共通的)인 계획자료(計劃資料)를 사용하여 L.P.문제를 수식화(數式化)해 가면서 그들의 차이점(差異點)을 비교 검토하고 Model II가 삼림(森林)의 변화(變化)를 표현하는데 있어서나 문제를 분석하는데 있어서 Model I 보다 더 간편하다는 사실을 재확인했다.

• 정신신체의학
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• 제7권1호
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• pp.10-25
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• 1999

2세이상의 어린이는 성적 흥분을 느낄 수 있기에 만지거나 자위행위 등의 성적인 즐거움을 찾기 시작 한다. 60년대 후반부터 70년대 초반사이 산부인과 의사 Masters와 사회사업가 Johnson은 인간의 성반응 단계를 흥분기, 고원기, 오르가슴기, 반응소실기의 4단계로 나눠 설명하였고, 여성에게는 무반응기가 없어 여러번의 오르가슴이 가능함을 밝혔다. 그들의 성치료원칙은 행동치료에 입각하여 감각초점법과 부부치료, 성교육등으로 구성되어있다. Masters와 Johnson이후 정신과 의사이자 정신분석가인 Kaplan이 1970년대 초반에 정신분석적 정신치료와 행동치료를 결합한 '새로운 성치료'를 제안했다. 그리고, 성기능 장애를 3가지 카테고리로 재분류했다. 1980년대 이후는 남성의 발기부전의 치료를 중심으로 의학적 치료방법론이 대세를 이루고 있는데, 음경 보속물, 국소주사치료, 경구약제등이 발달하였다. 최근 Sildenafil(Viagra)이 등장해 남성 발기부전 치료의 최선의 선택으로 받아들여지고 있다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.1744-1748
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• 2007

In this study, the Johnson-Kendall-Roberts (JKR) theory was combined with the instrumented indentation technique (IIT) to evaluate work of adhesion and modulus of elastomeric polymer. Indentation test was used to obtain the load-displacement data for contacts between Tungsten Carbide indenter and elastomeric polymer. And the JKR contact model, contrived to take viscoelastic effects of polymer into account, was applied to compensate the contact area and the elastic modulus which Hertzian contact model would underestimate and overestimate, respectively. Besides, we could obtain the thermodynamic work of adhesion by considering the surface energy in this contact model. In order to define the relation between JKR contact area and applied load without optical measuring of contact area, we used the relation between applied load and contact stiffness by examining the correlation between JKR contact area and stiffness through dimensional analysis with 14 kinds of elastomeric polymer. From this work, it could be demonstrated that the interfacial work of adhesion and elastic modulus of compliant polymer can be obtained from a simple instrumented indentation testing without area measurement, and provided as the main algorithm of compliant polymer characterization.

• 대한기계학회논문집A
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• 제31권9호
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• pp.951-959
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• 2007

In this study, the Johnson-Kendall-Roberts(JKR) theory was combined with the instrumented indentation technique (IIT) to evaluate work of adhesion and modulus of elastomeric polymer. Indentation test was used to obtain the load-displacement data for contacts between Tungsten Carbide indenter and elastomeric polymer. And the JKR contact model, contrived to take viscoelastic effects of polymer into account, was applied to compensate the contact area and the elastic modulus which Hertzian contact model would underestimate and overestimate, respectively. Besides, we could obtain the thermodynamic work of adhesion by considering the surface energy in this contact model. In order to define the relation between JKR contact area and applied load without optical measuring of contact area, we used the relation between applied load and contact stiffness by examining the correlation between JKR contact area and stiffness through dimensional analysis with 14 kinds of elastomeric polymer. From this work, it could be demonstrated that the interfacial work of adhesion and elastic modulus of compliant polymer can be obtained from a simple instrumented indentation testing without area measurement, and provided as the main algorithm of compliant polymer characterization.

• Computers and Concrete
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• 제7권2호
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• pp.159-167
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• 2010

This paper demonstrates numerical techniques for complex large-scale modeling with microplane constitutive theories for reinforced high strength concrete, which for these applications, is defined to be around the 7000 psi (48 MPa) strength as frequently found in protective structural design. Applications involve highly impulsive loads, such as an explosive detonation or impact-penetration event. These capabilities were implemented into the authors' finite element code, ParaAble and the PRONTO 3D code from Sandia National Laboratories. All materials are explicitly modeled with eight-noded hexahedral elements. The concrete is modeled with a microplane constitutive theory, the reinforcing steel is modeled with the Johnson-Cook model, and the high explosive material is modeled with a JWL equation of state and a programmed burn model. Damage evolution, which can be used for erosion of elements and/or for post-analysis examination of damage, is extracted from the microplane predictions and computed by a modified Holmquist-Johnson-Cook approach that relates damage to levels of inelastic strain increment and pressure. Computation is performed with MPI on parallel processors. Several practical analyses demonstrate that large-scale analyses of this type can be reasonably run on large parallel computing systems.

• Journal of the Korean Statistical Society
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• 제27권4호
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• pp.495-506
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• 1998

The proposed class of generalized logistic models, indexed by an extra parameter, can be used to model or to examine symmetric or asymmetric discrepancies from the logistic model. When there are a finite number of different design points, we are mainly concerned with maximum likelihood estimation of parameters and in deriving their large sample behavior A score test and a bootstrap hypothesis test are also considered to check if the standard logistic model is appropriate to fit the data or if a generalization is needed .