• 한국과학교육학회지
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• 제27권1호
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• pp.37-49
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• 2007

본 연구의 목적은 우리나라 중등학교 지구과학 수업에서 교사들이 제공하는 과학적 설명을 논리적 형식에 따라 분류하고, 서로 다른 형식의 과학적 설명이 지니는 특징과 과학적 설명을 위한 담화 행위에서 교사와 학생들의 역할을 분석하는 것이었다. 연구를 위한 자료는 2003년과 2004년에 해외 단기 연수 프로그램에 참여한 지구과학 교사들로부터 수집되었으며, 총18차시에 해당하는 지구과학 수업 녹화 자료와 전사본을 분석하였다. 분석된 지구과학 수업에서는 연역-법칙적 설명이 가장 빈번히 발생하였고, 연역-법칙적 모형은 과학적 설명을 구성하는 데 필요한 과학 법칙이나 상위의 원리가 잘 정립된 문제에 알맞은 것임을 알 수 있었다. 하지만, 지구과학의 후진적 추론 과제를 다루는 상황에서는 귀추적 설명이 제공되었고, 일기 속담이나 기상 이변과 같이 지구과학에 특징적인 대상을 설명할 때에는 각각 통계-확률적 모형과 통계-유관성 모형에 부합하는 설명이 활용되었다. 지구과학수업에서 과학적 설명은 주로 교사의 단독적인 발화를 통해 이루어졌으며, 학생들은 과학적 설명을 구성하기 위한 담화 행위에서 주로 소극적인 역할을 담당하였다. 이상과 같은 연구 결과가 과학 수업과 과학교육 연구에 시사하는 점들을 논의하였다.

• International journal of advanced smart convergence
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• 제4권1호
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• pp.45-53
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• 2015

This paper is proposed mathematical load modelling based on system identification approach of energy consumption of residential air conditioning. Due to air conditioning is one of the significant equipment which consumes high energy and cause the peak load of power system especially in the summer time. The demand response is one of the solutions to decrease the load consumption and cutting peak load to avoid the reservation of power supply from power plant. In order to operate this solution, mathematical modelling of air conditioning which explains the behaviour is essential tool. The four type of linear model is selected for explanation the behaviour of this system. In order to obtain model, the experimental setup are performed by collecting input and output data every minute of 9,385 BTU/h air-conditioning split type with $25^{\circ}C$ thermostat setting of one sample house. The input data are composed of solar radiation ($W/m^2$) and ambient temperature ($^{\circ}C$). The output data are power and energy consumption of air conditioning. Both data are divided into two groups follow as training data and validation data for getting the exact model. The model is also verified with the other similar type of air condition by feed solar radiation and ambient temperature input data and compare the output energy consumption data. The best model in term of accuracy and model order is output error model with 70.78% accuracy and $17^{th}$ order. The model order reduction technique is used to reduce order of model to seven order for less complexity, then Kalman filtering technique is applied for remove white Gaussian noise for improve accuracy of model to be 72.66%. The obtained model can be also used for electrical load forecasting and designs the optimal size of renewable energy such photovoltaic system for supply the air conditioning.

• 마케팅과학연구
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• 제10권
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• pp.45-70
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• 2002

The purpose of this study is to obtain more insight into the explanation and prognosis of consumer behavior in real and virtual museums. The analysis focuses on the influence of the museum environment on the museum patrons (rather than on the influence of the art objects). On the basis of the emotional approach to environmental psychology by Mehrabian and Russell (1974), a behavior model has been developed for museums. The model, which is based on the emotional variables pleasure, arousal and dominance (PAD), is also enhanced by cognitive variabies (learning attractiveness, education standard and information demand). The enhancement of the classical model was necessary because cognitive variables play a major role in cultural institutions such as museums: One important objective of museums is the communication of cultural knowledge to visitors. The model is tested empirically using structural equation modeling. 301 visitors were interviewed individually. Two different museum environments were represented using visual stimuli. The theoretical model for museums can be proved empirically. The degree to which the model fits the empirical data was extensively tested. The model showed high compatibility with the data and could be accepted. The study proves that a model can be developed, which explains visitor behavior in museums. The model shows museum designers how museums should be designed to be both emotionally appealing and a learning environment. Based on empirical studies in virtual stores on the Internet, it is discussed whether the research findings in these environments may be applied to virtual museum environments. In order to create an emotionally appealing virtual museum, it is recommended that one uses a 3-dimensional representation to offer various possibilities for interaction and to create a multi-sensual environment that appears highly realistic.

• 보건행정학회지
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• 제23권2호
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• pp.145-151
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• 2013

Background: The objective of this study was to explore patient family's evaluation of emergency department (ED) service satisfaction and to compare these with ED staff perception of patient family's evaluation. Methods: Based on two surveys of the National Emergency Medical Center: the 2008 National Survey for Recognition and Satisfaction towards Emergency Medical Services and the 2008 Opinion Survey of Emergency Medical Service Providers, satisfaction gaps among physicians, nurses, and patient family were evaluated by Kruskal-Wallis tests and Wilcoxon-Mann-Whitney tests. Furthermore, the factors associated with satisfaction of emergency medical service were identified by ordinal logistic regression models. Results: There were statistically significant gaps among physicians, nurses, and patient family in overall satisfaction with ED visit, length of stay in ED, enough explanation, physicians/nurses kindness, and ED facilities. Age and income in the patient family model, the number of beds in hospital, job satisfaction and year of service in the physicians model, and the number of beds in hospital, job satisfaction and the number of patients per duty hour in the nurses model were statistically significant factors associated with evaluation/ perception of ED service satisfaction. Conclusion: Patient satisfaction is an important indicator of the quality of care and service delivery in the ED. To improve and understand satisfaction in ED service, a dyadic view of the evaluation of service quality and satisfaction-that is, from the perspectives of both the patient and the emergency medical service providers-should be concerned.

• 지식경영연구
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• 제13권4호
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• pp.83-100
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• 2012

Given the prevalence of mobile social network services (SNS) such as Facebook and Kakaotalk, it has become important to understand user's continuance behavior in a mobile SNS environment. Although trust and privacy concerns play a key role in SNS users' decision-making processes, most studies on SNS have shed little light on the effects of trust and privacy concerns on SNS continuance intention. In this regard, this paper developed an integrated model to deeply understand the key antecedents of user's continuance intention to use mobile SNS by incorporating trust and privacy concerns into extended expectation-confirmation model. The proposed research model was tested by using survey data collected from 170 users who have experience with Kakaotalk. The findings of this study found that the proposed theoretical framework provides a statistically significant explanation of the variance in continuance intention of mobile SNS. The analysis results indicate that trust serves as the salient antecedent of continuance intention to use mobile SNS. However, it was found that privacy concerns negatively influence trust, whereas it is not significantly related to continuance intention of mobile SNS. The theoretical and practical implications of the findings were described.

• JSTS:Journal of Semiconductor Technology and Science
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• 제14권2호
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• pp.153-162
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• 2014

We show that carbon nanotube sensors with gold particles on the single-walled carbon nanotube (SWNT) network operate as Schottky barrier transistors, in which transistor action occurs primarily by varying the resistance of Au-SWNT junction rather than the channel conductance modulation. Transistor characteristics are calculated for the statistically simplified geometries, and the sensing mechanisms are analyzed by comparing the simulation results of the MOSFET model and Schottky junction model with the experimental data. We demonstrated that the semiconductor MOSFET effect cannot explain the experimental phenomena such as the very low limit of detection (LOD) and the logarithmic dependence of sensitivity to the DNA concentration. By building an asymmetric concentric-electrode model which consists of serially-connected segments of CNTFETs and Schottky diodes, we found that for a proper explanation of the experimental data, the work function shifts should be ~ 0.1 eV for 100 pM DNA concentration and ~ 0.4 eV for $100{\mu}M$.

• 한국간호교육학회지
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• 제18권2호
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• pp.312-322
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• 2012

Objectives: The purpose of this study was to investigate the factors related to adjustment of college for nursing students and to develop a collective model for successful prediction and concrete paths of the factors. Methods: Data collection was conducted from May 19th 2010 to Jun 4th 2010. Five hundred thirty-one questionnaires were used for data analysis after distributing 560 sheets to senior students in 8 different locations. Data was analyzed with SPSS 18.0 Win program and AMOS 18.0. Results: Mother attachment does not have a direct effect on adjustment to college life but does effect psychological well-being and coping, which indirect adjustment to college life. In addition, the more psychological well-being and coping usage frequency, and the less stress of clinical practice, the higher score of adjustment to college life. According to the results, explanatory power of the model for the college nursing students' adjustment was 62.0%. Conclusions: To improve adjustment to college life, it is recommended to have a direct method of developing psychological well-being and coping improvement program to improve mother attachment. The research is meaningful in a sense that it explains the cause and effect relationship between adjustment to college life and relevant variables to predict comprehensive dimensional explanation of adjustment of college life for nursing students.

• Asia pacific journal of information systems
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• 제12권1호
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• pp.139-158
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• 2002

As the telecommunication market becomes mature in Korea, severe competition has already begun on the market. While service providers struggled for the last couple of years to acquire as many new customers as possible, nowadays they are making more efforts on retaining the current customers. The churn management by analyzing customers' demographic and transactional data becomes one of the key customer retention strategies which most companies pursue. However, the customer data analysis has still remained at the basic level in the industry, even though it has considerable potential as a tool for understanding customer behavior. This paper develops several churn prediction models using data mining techniques such as logistic regression, decision trees, and neural networks. For model-building, real data were used which were collected from one of the major telecommunication companies in Korea. This paper explores various ways of comparing model performance, while the hit ratio was mainly focused in the previous research. The comparison criteria used in this study include gain ratio, Kolmogorov-Smirnov statistics, distribution of the predicted values, and explanation ability. This paper also suggest some guidance for model selection in applying data mining techniques.

• Nuclear Engineering and Technology
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• 제34권5호
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• pp.482-493
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• 2002

The MOX fuel for LWR is fabricated either by direct mechanical blending of UO$_2$ and PuO$_2$ or by two stage mixing. Hence Pu-rich particles, whose Pu concentrations are higher than pellet average one and whose size distribution depends on a specific fabrication method, are inevitably dispersed in MOX pellet. Due to the inhomogeneous microstructure of MOX fuel, the thermal conductivity of LWR MOX fuel scatters from 80 to 100 % of UO$_2$ fuel. This paper describes a mechanistic thermal conductivity model for MOX fuel by considering this inhomogeneous microstructure and presents an explanation for the wide scattering of measured MOX fuel＇s thermal conductivity. The developed model has been incorporated into a KAERI＇s fuel performance code, COSMOS, and then evaluated using the measured in-pile data for MOX fuel. The database used for verification consists of homogeneous MOX fuel at beginning-of-life and inhomogeneous MOX fuel at high turnup. The COSMOS code predicts the thermal behavior of MOX fuel well except for the irradiation test accompanying substantial fission gas release. The over-prediction with substantial fission gas release seems to suggest the need for the introduction of a recovery factor to a term that considers the burnup effect on thermal conductivity.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2008년도 춘계학술대회논문집
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• pp.21-24
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• 2008

The present study numerically investigates the glottal airflow characteristics as well as acoustic features of phonation fully coupled with dynamic behavior of vocal folds. The vocal folds are described by a low-dimensional body-covered model characterized by bio-mechanical parameters such as glottal width, vocal folds stiffness, and subglottal pressure. The flow in the vocal tract is modeled as an incompressible, axisymmetric form of the Navier-Stokes equations (INS), while the acoustic field is predicted by the linearized perturbed compressible equations (LPCE). The computed result shows that a two-mass model of vocal folds is sufficient to reproduce temporal variations in oral airflow and glottis motion produced by female speakers. It is also found that i) the glottal width has a significant effect on the amplitude of glottal flow, and thus on the amplitude of acoustic wave in the vocal tract, ii) the vocal fold tension is the main control parameter for the fundamental frequency of phonation, iii) the subglottal pressure plays an appreciable role on reproduction of the self-sustained oscillation of vocal folds, and iv) the strength of pulsating airflow and vortical structures are primarily affected by glottal width and subglottal pressure, and are closely related to pitch, loudness, and voice quality. Finally, more comprehensive explanation about the difference between one- and two-mass models is presented with discussion of effectiveness of vocal folds oscillation and voice quality.