• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2007년도 추계학술대회 논문집
• /
• pp.830-835
• /
• 2007

In this paper, stress analyses using shell and solid elements on weld zone of railway bogie frame were performed. To calculate stress distribution on weld zone, a coupling model using shell and solid elements was suggested. For this purpose, we performed specimen analyses on T-type solid and shell model of T-type panels which were modeled using shell elements, solid elements and coupled elements, respectively. The result showed that the stress concentration at weld zone was occurred in solid model, but it didn't occur in shell model. And the stress distribution of coupled model was similar to that of solid model. Also, we applied the coupled modeling method on the analysis on weld zone of bogie frame. The stress distribution of coupled model showed much higher compared to that of shell only model. Therefore, the coupled model method is highly recommended for the stress analysis in weld zone of bogie frame.

• 한국지진공학회:학술대회논문집
• /
• 한국지진공학회 1999년도 춘계 학술발표회 논문집 Proceedings of EESK Conference-Spring
• /
• pp.275-283
• /
• 1999

To predict the dynamic behavior of the cylindrical liquid storage tank subjected to seismic ground motion three dimesional analysis with liquid-structure interaction must be performed, In this study a three dimensional dynamic analysis method over the frequency domain using FE-BE coupling technique which combines the efficiency of the boundary elements for liquid with the versatility of the finite shell elements for tank. The liquid region is modeled using boundary elements which can counter the sloshing effect at free surface and the structure region the tank itself is modeled using the degenerated finite shell elements. At the beginning of the procedure the equivalent mass matrix of the liquid is generated by boundary elements procedure. Then this equivalent mass matrix is combined with the mass matrix of the structure to produce the global mass matrix in the equation of the motion of fluid-structure interaction problem In order to demonstrate the accuracy and validity of the developed method the numerical results re compared with the previous studies. Finally the effects of the fluid-structure interaction on the natural frequency and dynamic response of the system are analyzed.

• 대한기계학회논문집
• /
• 제17권11호
• /
• pp.2694-2703
• /
• 1993

In the vibration analysis of Timoshenko beams by the finite element method, it is necessary to use a large number of elements or higher-order elements in modeling thin beams. This is because the overestimated stiffness matrix due to the shear locking phenomenon when lower-order displacement-based elements are used yields poor eigensolutions. As a result, the total number of degrees of freedom becomes critical in view of computational efficiency. In this paper, the curvature-based formulation is applied to the vibration problem. It is shown that the curvaturebased beam elements are free of shear locking and very efficient in the vibration analysis.

• 분석과학
• /
• 제18권6호
• /
• pp.520-528
• /
• 2005

Two biological Certified Reference Materials (CRMs), KRISS 108-04-001 (oyster tissue) and 108-05-001 (water dropwort stem), were prepared by Korea Research Institute of Standards and Science (KRISS)during FY '01. The certified values of these materials had been determined by Isotope Dilution Mass Spectrometry (IDMS) for six elements (Cd, Cr, Cu, Fe, Pb and Zn). Additional analytical works are now progressing to certify the concentrations of a number of the environmental and nutrimental elements in these CRMs. The certified values in a CRM are usually determined by using a single primary method with confirmation by other method(s) or using two independent critically-evaluated methods. Instrumental Neutron Activation Analysis (INAA) plays an important role in the determination of certified values as it can eliminate the possibility of common error sources resulting from sample dissolution. In this study INAA procedure was used in determination of 23 elements in these two biological CRMs to acquire the concentration information and the results were compared with KRISS certified values.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 1998년도 추계학술대회 논문집
• /
• pp.421-428
• /
• 1998

Sensitivity analysis of suspension elements of an articulated bogie for light railway vehicles is presented. The ride, stability and safety are used as dynamic performance index. Suspension elements of 10 and a conicity of wheel are used as design variables, To analyze sensitivity of design variables, the railway vehicle dynamics analysis program AGEM is used. The results shows that the secondary suspension elements have a strong effect on ride and the primary suspension elements have a moderate effect on ride. Conicity of wheel has a strong effect on the stability, The safety is not effected by all the design variables.

• 한국생활과학회지
• /
• 제24권2호
• /
• pp.297-325
• /
• 2015

The purpose of this research is to analyze content elements of Housing area in 2013 middle school Technology Home Economics textbooks 1 and 2, total of 22 according to 2009 revised curriculum. The analysis method was content analysis, focusing on contents of main text, tables & figures, reading material, and activity materials by their content elements. This research will contribute in obtaining suggestion for the post curriculum/textbook development and helping teachers to perform a lesson. The results are as follows. First, Housing area included 1 to 4 content elements per each units, from 2 chapters and 6 units. The content elements stated in Home economics curriculum were total of 16 which consists of 'the meaning of housing,' 'housing types,' 'family forms,' 'family life style cycle,' 'life style,' 'neighboring environment,' 'co-living values,' 'air environment,' 'heat environment,' 'light environment,' 'acoustic environment,' 'space division,' 'circulation', 'effective use of space,' and 'sustainable dwelling practice.' All of these components are dealt with in every textbooks. Second, the numbers of content elements provided in each textbooks were the same, however they showed difference in their contextual aspect. Some contents need supplemental material for their lacking content element. Others need proper understanding of the concept because some showed different contents from the appropriate content elements. Third, repetitions in content elements were observed, the contents of 'co-living values' in textbook 1 and 'sustainable dwelling practice' in textbook 2 were similar in terms of eco-friendly housing, co-housing and universal housing. These two content elements should be merged as one next curriculum, or should be stated together in one subunit.

• 분석과학
• /
• 제12권4호
• /
• pp.346-353
• /
• 1999

For the non-destructive multi-elemental analysis of environmental and biological materials, instrumental neutron activation analysis (INAA) was applied for the determination of toxic and trace elements in a set of three Algae samples provided by the International Atomic Energy Agency (IAEA). The analytical quality control was evaluated by comparing the analytical results of two standard reference materials of the National Institute of Standards and Technology (NIST); Oyster Tissue (SRM 1566a) and Citrus Leaves (SRM 1572). According to given analytical procedure, the concentration of 15-25 elements including spiked elements such as As, Cd, Cr and Hg in Algae samples were determined. To identify and validate these results, a data intercomparison program using more than 35 analytical methods in 150 laboratories was carried out and the estimated statistical data are summarized. Result of INAA is favorable, therefore, it is illustrated that can be applied for routine analysis of essential and toxic elements in algae samples as well as analytical quality assurance.

• 한국실내디자인학회논문집
• /
• 제21권2호
• /
• pp.112-122
• /
• 2012

The purpose of this study is to provide fundamental data that can improve added value of commercial space strategically using the identification of relationship between the process of consumers' purchasing psychology (AIDMA : Attention, Interest, Desire, Memory, Action) and elements of interior design. For this purpose, case study and survey were carried out on food and beverage spaces, where they were doing business for more than two years, were selected from the ones appeared in the interior journal "A." Based on the study, basic details including a ground plan, design summary and representative image were identified through preliminary research, and a researcher visited the target spaces and carried out a research and analysis on interior design elements. Three spaces among targets of the case study were selected to identify the relation between design elements and AIDMA items which consumers feel, and the survey was conducted on the customers of the selected food and beverage spaces. Results of the case study on the 18 food and beverage spaces showed that features of the each of AIDMA items in material and color elements were most well expressed. As a result of survey conducted on visitors of each food and beverage space, features of each item were expressed in overall design elements. In particular, space elements and color elements in "Space 1," space elements and lighting elements in "Space 2" and space elements, furniture & objet elements in "Space 3" were most well expressed in each space. There were slight differences depending on individual characteristics such as design concept, location and business operation of target food and beverage spaces but attributes of AIDMA items were remarkably recognized in common in the space elements.

• 한국전산구조공학회:학술대회논문집
• /
• 한국전산구조공학회 2005년도 춘계 학술발표회 논문집
• /
• pp.521-528
• /
• 2005

In this paper, three dimensional dynamic infinite elements are developed for the soil-structure interaction analysis in multi-layered halfspace. For the efficient discretization of 3-D for field regions, five types of dynamic infinite elements are developed. They are the horizontal, vertical, horizontal comer, vertical comer and horizontal/vertical corner infinite elements. The shape functions of the infinite elements are based on approximate expressions of analytical solutions of propagating waves in the infinite region. Numerical example analyses are presented for compliances of rigid circular and square plates to demonstrate the effectiveness of the proposed infinite elements.

• 아동학회지
• /
• 제28권3호
• /
• pp.163-173
• /
• 2007

This study analyzed ecological elements of 140 nursery rhymes, stories, and plays in the $6^{th}$ edition of the Guide for Educational Activities and Materials for Kindergarten. The results show that 24 works(17.1%) have ecological elements. Content analysis of ecological elements in these works show works that deal with the side effects of environmental development(3 nursery stories), the cult of nature(1 nursery rhyme), recognition of the eco-cycle(2 nursery rhymes, 4 stories, 2 plays), dignity of life and recovery of human nature(12 nursery stories). On the basis of the results, children's literature containing ecological elements were suggested.