• Journal of Animal Science and Technology
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• 제61권6호
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• pp.324-332
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• 2019

This study aimed to identify the causality between climatic and soil variables affecting the yield of Italian ryegrass (Lolium multiflorum Lam., IRG) in the paddy field by constructing the pathways via structure equation model. The IRG data (n = 133) was collected from the National Agricultural Cooperative Federation (1992-2013). The climatic variables were accumulated temperature, growing days and precipitation amount from the weather information system of Korea Meteorological Administration, and soil variables were effective soil depth, slope, gravel content and drainage class as soil physical properties from the soil information system of Rural Development Administration. In general, IRG cultivation by the rice-rotation system in paddy field is important and unique in East Asia because it contributes to the increase of income by cultivating IRG during agricultural off-season. As a result, the seasonal effects of accumulated temperature and growing days of autumn and next spring were evident, furthermore, autumnal temperature and spring precipitation indirectly influenced yield through spring temperature. The effect of autumnal temperature, spring temperature, spring precipitation and soil physics factors were 0.62, 0.36, 0.23, and 0.16 in order (p < 0.05). Even though the relationship between soil physical and precipitation was not significant, it does not mean there was no association. Because the soil physical variables were categorical, their effects were weakly reflected even with scale adjustment by jitter transformation. We expected that this study could contribute to increasing IRG yield by presenting the causality of climatic and soil factors and could be extended to various factors.

• 과학교육연구지
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• 제38권2호
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• pp.454-469
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• 2014

교사 개인의 자연 및 과학에 대한 관점은 학교교육과정에서 교육받기 이전부터 주변 환경과의 상호 작용 및 일상생활 속에서의 경험 등을 통해 형성되어, 과학학습지도에 직접적인 영향을 주게 된다. 이에 본 연구에서는 과학의 본성, 과학의 인과성, 그리고 자연이 무엇이라고 생각하는지에 대한 교사의 관점을 종합적으로 조사하였다. 본 연구에서는 Q방법론을 이용하였다. 과학의 본성, 과학적 인과성, 자연에 대한 81개의 진술문이 사용되었고, 12명의 과학교사가 각 진술문에 대해 동의하는 정도를 응답한 후, 요인분석을 통해 교사의 관점을 유형별로 구분하였다. 분석결과, 과학의 본성, 과학적 인과성, 그리고 자연에 대해서 교사의 관점이 크게 5개 유형으로 분류될 수 있었고, 유형별 특징을 알아볼 수 있었다. 그리고 과학의 본성, 과학적 인과성, 자연에 대한 관점들이 서로 연관되어 있다는 것도 확인할 수 있었다. 이러한 연구방법은 앞으로도 교사의 다양한 관점을 상호 연관지어 종합적으로 이해하는데 도움이 될 것으로 기대한다.

• 한국시뮬레이션학회논문지
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• 제25권4호
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• pp.109-115
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• 2016

본 연구는 철도기관사에 의해 유발되는 사고와 우울감 및 인지실패 간의 관계를 '우울감 ${\rightarrow}$ 인지실패 ${\rightarrow}$ 사고'의 인과관계로 접근하는 연구모형 1과 '사고 ${\rightarrow}$ 우울감 ${\rightarrow}$ 인지실패'의 인과관계로 접근하는 연구모형 2로 설정하고 어느 모형이 타당한지를 구조방정식 모형으로 검증하였다. 현직 철도기관사 416명의 설문응답 유효데이터를 토대로 검증한 결과 후자의 연구모형, 즉 '사고 ${\rightarrow}$ 우울감 ${\rightarrow}$ 인지실패'의 인과관계에서 사고가 우울감을 매개로 하여 사고에 영향을 미친다는 점에서 모형 2가 통계적으로 타당하다는 결론을 도출하였다. 이 같은 연구결과는 인적오류와 관련하여 사고와 우울감의 인과관계 측면에서 접근하고 제도적인 개선방안을 함께 모색할 때 궁극적으로 기관사의 실수와 인지실패를 저감시킴으로써 인지실패로 인한 사고와 인적 오류의 확률을 그만큼 저감할 수 있다는 것을 시사한다.

• Child Health Nursing Research
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• 제6권3호
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• pp.291-304
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• 2000

The purpose of this study was to explore the health and illness concepts of hospitalized preschoolers. The subjects were 52 hospitalized preschoolers from 3 to 6 grade in one general hospital. Data were collected through semistructured interviews by author. this study was conducted from Mar 2, 2000 to Jun. 30, 2000. Data were coded and categorized by content analysis. The results were as follows : 1. Hospitalized preschoolers's answers about health concepts were coded and then classificated to 7 categories(physical well-being, food, powerfulness, exercise, obedience to authority, cleanliness, sleep.) 2. Hospitalized preschoolers's answers about health behavior to maintenance health were coded and then classificated to 8 categories (food, obedience to authority, treatment, exercise, cleanliness, powerfulness, sleep, psychological stability). 3. Hospitalized preschoolers's answers about prevention of illness were coded and then classificated to 9 categories(food, treatment, obedience to authority, powerfulness, emotional stability, psychological stability, exercise, physical well-being, ability of social adaption). 4. Hospitalized preschoolers's answers about cause of illness were coded and then classificated to 3 categories(illness, trauma, food). 5. Hospitalized preschoolers's answers about treatments of illness were coded and then classificated to 9 categories(treatment, rest, emotional stability, sleep, psychological stability, food, obedience, exercise, powerfulness). 6. The levels of health and illness concepts in this sample were higher than those of the physical causality.

• 한국자동차공학회논문집
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• 제11권5호
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• pp.156-162
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• 2003

The shock absorber is a part having a direct influence on the ride comfort, stability and dynamic load prediction of a vehicle. Thus, a rationally modeled shock absorber should be required in the dynamic analysis of vehicles. This thesis presents a modified model, based on Worden's hyperbolic tangent function, in order to fit experimental data on the velocity-damping force of a shock absorber. The hyperbolic tangent function correctly indicates the characteristics of a shock absorber, and has the advantage of containing physical causality. To evaluate the method, comparative evaluations of the linear model, the 5th polynomial model and Worden's model were carried out. The function presented in this paper is not only simple but also makes it possible to estimate the function coefficients easily and visually. In addition, it has the advantage of containing physical causality. Lastly, it effectively models the damping force of a shock absorber.

• 한국시뮬레이션학회논문지
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• 제4권2호
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• pp.31-40
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• 1995

A hybrid simulation model consists of real physical entities as well as simulated ones. It also contains logical processes for decision making for each operation units, a group of the entities. During the execution of such simulations, the physical and the logical processes consume real clock time while the activity durations of the simulated ones are generated. Due to the inherent chracteristics of the subjects of the communication channels. Since one can not undo an real event already taken place, the traditional central clock approach is used for the synchronization of the events(Kim[6]). However, there are still chances of causality errors due to the randomness in the communication delays. This error is not found in the distributed pure simulations. This paper explains the error in details and proposes a prevention scheme that is simple to implement.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.1479-1482
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• 2003

The shock absorber is a part having a direct influence on the ride comfort, stability and dynamic load prediction of a vehicle. Thus, a rationally modeled shock absorber should be required in the dynamic analysis of vehicles. This thesis presents a modified model, based on Worden's hyperbolic tangent function, in order to fit experimental data on the velocity-damping force of a shock absorber. The hyperbolic tangent function correctly indicates the characteristics of a shock absorber. and has the advantage of containing physical causality. To evaluate the method, comparative evaluations of the linear model. the 5th polynomial model and Worden's model were carried out. The function presented in this paper is not only simple but also makes it possible to estimate the function coefficients easily and visually. In addition, it has the advantage of containing physical causality. Lastly, it effectively models the damping force of a shock absorber.

• 대한기계학회논문집A
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• 제21권9호
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• pp.1414-1421
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• 1997

This paper examines the physics and mechanics governing the dynamic interaction between physical systems and suggests the four structures of bond graph prototypes, considered as a general model that can promise their dynamic behavior physically resonable. The bond graph prototypes originating from the paper are more realistic junction structures than those used to model dynamic systems conventionally by bond graph standards in whether physical constraints are involved or not when the energy exchange between two dynamic components arises. It is shown that the bond graph prototypes are dynamic or energetic in their describing equations compared to the bond graph standards, and connectivity and causality are properties of dynamic systems upon which the steps developed in this paper for the bond graph prototypes are wholly based and their definitions an concepts are highly emphasized all through the paper.

• 아동학회지
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• 제28권4호
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• pp.245-264
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• 2007

This study analyzed physical knowledge displayed in the utterances of 10 Korean children 23 - 76 months of age. Utterances were blocked into four-month time periods, except the first two months and classified into 5 categories including properties of physical objects and materials, friction, buoyancy, gravity, and the motion of physical objects. All five types of physical expressions were found in the data of the earliest period the percent age of the properties and motion was higher than the percent of friction, buoyancy, and gravity. Data suggested two transitional points of change in physical knowledge : 2-year-old's descriptions were based only on perceptually salient physical features 3- to 4-year-olds described only end-state results while children older than 4 included systematic causality.

• 대한간호학회지
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• 제22권2호
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• pp.143-156
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• 1992

This descriptive study explored the health and illness concepts of preschoolers to provide understanding on which to build research. The subjects were convenience sample three to six year of age attending one art institute in Cheju city. Data were collected through semistructured interviews by author, Children were asked to draw two figures, one healthy and one ill persons. The drawings were not analysed to grasp the meaning as in a projective technique, but only to relate to their response. Data were coded and categorized by content analysis. The results of this study are summarized as follows : 1) Three year olds responded with some unrelated answers but well to questions related to their experiences of illness ; older participants answered questions related health and illness concepts more easily. Generally the levels of subjects' responses did not differ according to age and sex. 2) Preschoolers' answers about the cause, treatment and prevention of illness, and the meaning and promotion of health were coded and then classificated to 9 categories, (food, obedience to authoritys physical function, presence or absence of illness or symptoms, hygiene. treatment, traumatic injury, rest and germs). Food and obeidence to authority categories were most frequent responses the food category was associated with obeidence to authority because it seemed that the children follow the orders of their parents or other authority figures to eat or not to eat something This result was compatible with that of previous studies that preschoolers perceived illness as possible punishment for misbehavior. Participants except for one four year old boy did not suggest that germs cause illness. The children perceived themselves and their families as healthy even though they had symptoms of illness. 3) Preschoolers' health and illness concepts were. influenced by their experiences and related to their development that rules derived from authority and if not complied with, will bring punishment. These oonceptualizations may be the disparity that they perceived themselves and their families as healthy even though they were ill. A previous study by Perrin and Gerrity suggested that the level of children's illness concepts correlated with that of their physical causality and was lower than it. But the levels of health and illness concepts in this sample higher than those of the physical causality.