• Journal of the Korea Society for Simulation
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• v.10 no.1
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• pp.63-65
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• 2001

To investigate the natural frequencies of curved piping systems with various elbow angles conveying flow fluid, a simulation is performed considering Initial tension due to the inside fluid. The system is analyzed by finite element method utilizing straight beam element. Elbow part is meshed using 4 elements, and the initial tension is considered by inserting equivalent terms into the stiffness matrix. Without considering the initial tension, the system becomes unstable, that is, the fundamental natural frequency approaches to zero value fast, as the flow velocity reaches critical value. With the initial tension terms, the system becomes stable where there is no abrupt decrease of the fundamental natural frequency. The change rate of the natural frequency with respect to the flow velocity reduces. As elbow angle increases, the system becomes stiffer, then around 150 degrees of the elbow angle the natural frequency has the largest value, the value decreases after the angle of the largest natural frequency. When angle is between 170 degrees and 179 degrees, the natural frequency is very sensitive. This means that small change of angle results in great change of natural frequency, which is expected to be utilized in the control of the natural frequency of the piping system conveying flow fluid.

• Journal of the Korean Society of Clothing and Textiles
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• v.28 no.2
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• pp.280-291
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• 2004

Apparel goods are classified by many criteria for ease of merchandising implementation. Fashion and basic goods are also an oucome oi classification. Previous studies pnvide some criteria by which apparel products can be classified into fushion and basic goods. Among those ciiteria, seasonality, fashionability, clothing types, complexity in pnduction, simplicity of style, pioducuon volume, degree of style change by season, could be listed. This study, first explored how apparel merchandisers and designers define fashion and basic goods in relation with those criteria. Definitions of fashion and basic goods were explored in terms of design elements (i.e., style, color, material), production volume, sales ratio, proportion in product assortment, and contribution to profit. The study adopted a qualitative approach by use of eighteen infepth interviews with menhandisers and designers. Six were from women＇s wear brand, Seven from men＇s wear brand, and 5 from casual wear brand. All the interviewees agreed that they are using the classification of basic vs. fashion goods. However, they are using diverse terms to indicate the basic and fashion goods. The interviewees defined each group based on its contribution to total sales or profit complexity in design, production volume, and style change by season. Basic goods had a higher level of production quantity, contribute more to profit simpler design, and less style change by season than fashion goods.

• Bulletin of the Korean Chemical Society
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• v.25 no.12
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• pp.1779-1783
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• 2004

In the present study, we carried out comparative research on the anthraquinones Raman spectrum and on the anthraquinones derivative 1,4-diamino-anthraquinone focusing on change in its intermediate in terms of pH and change in the substituent. WE use the SERS method and employ a silver sol prepared by Creighton et al.'s method. From the analysis of the UV spectrum of the mixture solution of 1,4-diamino-anthraquinone and silver sol, we could see that the 1,4-diamino-anthraquinone physically adsorbs silver sol. In terms of the adsorbing orientation, the adsorption of the nitrogen atom in the amino group is perpendicular to the surface of silver sol according to the surface selection rule. From the structure of the 1,4-diamino-anthraquinone intermediate according to the change of pH, we could see that the C=O bond is strengthened in the acidic state and weakened in the neutral and the alkaline state because of the resonance effect of the amines.

• International Journal of Contents
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• v.9 no.2
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• pp.66-69
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• 2013

In the U.S., performance assessment on the Automatic Exposure Control system (AEC) is managed according to the Mammography Quality Standards Act (MQSA). However, The AEC is not available in the performance assessment conducted in Korea. Also, there is no study made on the performance of the automatic exposure control system for mammography in Korea. For this reason, this study examined the performance of the automatic exposure control system for mammography that was clinically used in the Incheon area. Result showed that the difference of the mean optical density was 0.79 ~ 2.81. This implies that some devices caused unnecessary x-ray exposure to patients. Furthermore, only 61.5% of the entire experimental device was shown to be satisfactory in terms of change in mean optical density. Moreover, in terms of the subject's thickness, change in radiographic density was shown to be severe among lower X-ray tube voltage while there was severe density change in X-ray image depending on X-ray tube voltage among the subjects with more thickness. Therefore, it is suggested to provide performance management on the AEC for mammography.

• Proceedings of the Korean Nuclear Society Conference
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• 2001.10a
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• pp.137.1-137
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• 2001

• Korean Institute of Interior Design Journal
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• v.14 no.2 s.49
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• pp.12-19
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• 2005

After an important construction work in Chosun dynasty, the appropriate government made out the building specification as it called 營建儀軌. They are recorded about variety matters as the appointed days, various official documents, managers and craftsmen, etc.. Sometimes we can see the attached pictures about some building or furniture. specifications in Chosun dynasty about the unit of materials and history of each terms. The results are as followings: (1) The interior materials are classified to several units such as Gai(箇;the unit of square lumber or log), Rip(立;the unit of plates), Boo(部;the unit of assembled materials), etc.. (2) The terms are defined and enlightened how to use and how to change. Particularly, the terms are different positively in constituent units of wooden floor. So, it is expected to continuant study.

• Hwankyungkyoyuk
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• v.23 no.3
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• pp.1-16
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• 2010

Global climate change becomes one of the most serious environmental problems over the world. There is growing recognition thai climate change education, especially for children is important. However, there have been few programmes, curricula, teachers' training chances, and teaching-learning materials for climate change education so far. Therefore, we analyse the world wide web(web) contents in Korea which are available for climate change education, providing fundamental data in developing educational contents for climate change, as well as helping users to search appropriate contents for climate change education. Subjects for this study are 10 web sites of public institutions related to climate change in Korea. The web contents are evaluated in terms of diversity, accuracy, authenticity and the ease of use. The key finding in this study is that the majority of the contents are focused on how to respond to the problem, especially mitigation and also we find that most of the web sites provide text-types of lesson plan and video-types. Consequently, it would be necessary to develop various web contents for climate change education in both quality and quantity aspects.

• Korean Journal of Health Education and Promotion
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• v.27 no.2
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• pp.79-93
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• 2010

Objectives: This study aims to identify the factors associated with the stages of change in colorectal cancer screening, and develop a model explaining these stages of change by using structural equation modeling analysis. Methods: On the basis of literature review and expert advice, we constructed our hypothetical model that consisted of five theoretical constructs(process of change, pros, cons, self-efficacy, stage of change). In 2009, data was collected from 486 participants aged between 50 and 69. The data were analyzed by SPSS 15.0 and AMOS 6.0. Results: In the case of stage of adoption, the contemplation stage was the most common (37.4%), followed by the action stage (26.5%). In the final model of the stage of change for colorectal cancer screening, there was a direct influence of the process of change ($\gamma$=.562, p<.001), and cons ($\gamma$=.132, p<.01) on the stage of change with the terms of GFI .931, AGFI .904, RMR .038, NFI .930, and NNFI .936. Conclusion: It is necessary to produce and disseminate evidence-based cancer screening information, which can mitigate the negative attitude among the public toward cancer screening. Also, it is essential to provide a safer and more comfortable environment at cancer screening center.

• Proceedings of the ESK Conference
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• 1998.04a
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• pp.194-199
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• 1998

The purpose of this study is conducted to evaluate the psycho-physiological effects of the dynamic lighting on VDT workers and to establish the dynamic lighting design guides. The main experimental factors are changes of illuminance. There were five conditions including 1) ripid change, 2) slow change at 300lx .approx. 500lx, 3) a static illuminance level at 300lx, and 4) rapid chante, 5) slow change at 200lx .approx. 300lx. The ranges of change were set typical illuminance level for the simple visual task requirement and reasonable to a VDT task ; 200-300-500lx. The psycho-physiological measurements used were EEG, R-R interval, CFF, near point accommodation, feeling perceived fatigue, and work performance. Analysis of psycho-physiological factors shows that higher illumination level conditions are more affirmative effects than lower on VDT workers under 500lx except for the results of feeling perceived fatigue. And about the speed of changes of illuminance level. The conditions of slow change were better than the others in terms of the work performance as well as psycho-physiological results.

• 한국데이터정보과학회:학술대회논문집
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• 2003.10a
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• pp.57-72
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• 2003

This article provides integrated neural network models for the interest rate forecasting using change-point detection. The model is composed of three phases. The first phase is to detect successive structural changes in interest rate dataset. The second phase is to forecast change-point group with data mining classifiers. The final phase is to forecast the interest rate with BPN. Based on this structure, we propose three integrated neural network models in terms of data mining classifier: (1) multivariate discriminant analysis (MDA)-supported neural network model, (2) case based reasoning (CBR)-supported neural network model and (3) backpropagation neural networks (BPN)-supported neural network model. Subsequently, we compare these models with a neural network model alone and, in addition, determine which of three classifiers (MDA, CBR and BPN) can perform better. For interest rate forecasting, this study then examines the predictability of integrated neural network models to represent the structural change.