• Geotechnical Engineering
• /
• v.1 no.1
• /
• pp.59-72
• /
• 1985

This paper deals with the numerical analysis by the (mite element method introducing Biot's theory of consolidation and the modified Cambridge model proposed by Roscoe school of Cambridge University as constitutive equation and using Christian-Boehner's technique. Especially, time interval and division of elements are investigated in vies of stability and economics. In order to check the validity of author's program, the program was tested with one-dimensional consolidation case followed by Terzaghi's exact solution and with the results of the Magnan's analysis for existing banking carried out for study at Cubzac-les-ports in France. The main conclusions obtained are summarized as follows: 1. In the case of one-dimensional consolidation, the more divided the elements are near the surface of the foundation, the higher the accuracy of the numerical analysis is. 2. For the time interval, it is stable to divide 20 times per 1-lg cycle. 3. At the element which has long drain distance, the Mandel-fryer effect appears due to time lag. 4. Lateral displacement at an initial loading stage predicted by author's program, in which the load was assumed as not concentrative. but rather in grid form, is well consistent with the value of observation. 5. The pore water pressure predicted by author's program has a better accordance with the value of observation compared with Magnan's results. 6. Optimum construction control by Matsuo-Kawamura's method is possible with the predicted lateral displacement and settlement by the program.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
• /
• v.4 no.1
• /
• pp.31-42
• /
• 2000

The dry deposition velocities and fluxes of air pollutants such as SO2(g), O3(g), HNO3(g), sub-micron particulates, NO3(s), and SO42-(s) were estimated according to local meteorological elements in the atmospheric boundary layer. The model used for these calculations was the multiple layer resistance model developed by Hicks et al.1). The meteorological data were recorded on an hourly basis from July, 1990 to June, 1991 at the Austin Cary forest site, near Gainesville FL. Weekly integrated samples of ambient dry deposition species were collected at the site using triple-fiter packs. For the study period, the annual average dry deposition velocities at this site were estimated as 0.87$\pm$0.07 cm/s for SO2(g), 0.65$\pm$0.11 cm/s for O3(g), 1.20$\pm$0.14cm/s for HNO3(g), 0.0045$\pm$0.0006 cm/s for sub-micron particulates, and 0.089$\pm$0.014 cm/s for NO3-(s) and SO42-(s). The trends observed in the daily mean deposition velocities were largely seasonal, indicated by larger deposition velocities for the summer season and smaller deposition velocities for the winter season. The monthly and weekly averaged values for the deposition velocities did not show large differences over the year yet did show a tendency of increased deposition velocities in the summer and decreased values in the winter. The annual mean concentrations of the air pollutants obtained by the triple filter pack every 7 days were 3.63$\pm$1.92 $\mu\textrm{g}$/m3 for SO42-, 2.00$\pm$1.22 $\mu\textrm{g}$/m-3 for SO2, 1.30$\pm$0.59 $\mu\textrm{g}$/m-3 for HNO3, and 0.704$\pm$0.419 $\mu\textrm{g}$/m3 for NO3-, respectively. The air pollutant with the largest deposition flux was SO2 followed by HNO3, SO42-(S), and NO3-(S) in order of their magnitude. The sulfur dioxide and NO3- deposition fluxes were higher in the winter than in the summer, and the nitric acid and sulfate deposition fluxes were high during the spring and summer.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.37 no.1
• /
• pp.28-42
• /
• 2009

In the wake of categorizing the design changes occurred during the period from 2004 till the first half of 2006 in Choongcheong province area, based on purpose and reason of design changes identified by the Korea National Housing Corp, it included 11 types such as the image of the apartment complex, scenic elements, consideration by the user, prevention of the defect, constructability, site conditions, incompatibility between the activities, superordinate standard, prevention of civic complaints, design details and others, along with 47 subordinate elements. And the evaluation intended to identify the corelation between the number and time of design change approval, frequency and scale of design change by type and the cost variations indicated that; firstly, enhancing the image of the apartment complex proved to be the main reason for design changes, accounting for 22% in terms of frequency and 54.9% in terms of cost variation. Secondly, the higher the increase in cost by design change aimed at improving the image of the complex, the lower the decrease in cost by design change for uncertain reasons, dubbed the inverse proportional relations, indicating that the design changes for uncertain reasons were mostly aimed at reducing the construction cost. Thirdly, with regard to the number of design change approval and the time of the initial approval, twice or less and 90 days or less before completion of the construction work, respectively, accounted for $52{\sim}53%$, indicating the design change deliberation and approval tended to have been carried out collectively in the form of ex post facto approval, which seemed to be attributable to the attempt of reducing the construction cost or budget problem, as a result of comparing with the cases in which the cost was reduced.

• Proceedings of the Korean Society For Composite Materials Conference
• /
• 2003.10a
• /
• pp.46-49
• /
• 2003

Cu have been widely used as signal transmission materials for electrical electronic components owing to its high electrical conductivity. However, it's size have been limited to small ones due to its poor mechanical properties, Until now, strengthening of the copper at toy was obtained either by the solid solution and precipitation hardening by adding alloy elements or the work hardening by deformation process. Adding the at toy elements lead to reduction of electrical conductivity. In this aspect, if carbon nanofiber is used as reinforcement which have outstanding mechanical strength and electric conductivity, it is possible to develope Cu matrix nanocomposite having almost no loss of electric conductivity. It is expected to be innovative in electric conduct ing material market. The unidirectional alignment of carbon nanofiber is the most challenging task developing the copper matrix composites of high strength and electric conductivity In this study, the unidirectional alignment of carbon nanofibers which is used reinforced material are controlled by drawing process in order to manufacture the intermediary materials for the carbon nanofiber reinforced Cu matrix nanocomposite and align mechanism as well as optimized drawing process parameters are verified via experiments and numerical analysis. The materials used in this study were pure copper and the nanofibers of 150nm in diameter and of $10~20\mu\textrm{m}$ In length. The materials have been tested and the tensile strength was 75MPa with the elongation of 44% for the copper it is assumed that carbon nanofiber behave like porous elasto-plastic materials. Compaction test was conducted to obtain constitutive properties of carbon nanofiber. Optimal parameter for drawing process was obtained by experiments and numerical analysis considering the various drawing angles, reduction areas, friction coefficient, etc Lower reduction areas provides the less rupture of cu tube is not iced during the drawing process. Optimal die angle was between 5 degree and 12 degree. Relative density of carbon nanofiber embedded in the copper tube is higher as drawing diameter decrease and compressive residual stress is occurred in the copper tube. Carbon nanofibers are moved to the reverse drawing direct ion via shear force caused by deformation of the copper tube and alined to the drawing direction.

• Journal of Wetlands Research
• /
• v.13 no.1
• /
• pp.105-116
• /
• 2011

Changes in climate have largely increased concentrated heavy rainfall, which in turn is causing enormous damages to humans and properties. Therefore, the exact relationship and the spatial variability analysis of hydrometeorological elements and characteristic factors is critical elements to reduce the uncertainty in rainfall -runoff model. In this study, radar rainfall grid resolution and grid resolution depending on the topographic factor in rainfall - runoff models were how to respond. In this study, semi-distribution of rainfall-runoff model using the model ModClark of Inje, Gangwon Naerin watershed was used as Gwangdeok RADAR data. The completed ModClark model was calibrated for use DEM of cell size of 30m, 150m, 250m, 350m was chosen for the application, and runoff simulated by the RADAR rainfall data of 500m, 1km, 2km, 5km, 10km from 14 to 17 on July, 2006. According to the resolution of each grid, in order to compare simulation results, the runoff hydrograph has been made and the runoff has also been simulated. As a result, it was highly runoff simulation if the cell size is DEM 30m~150m, RADAR rainfall 500m~2km for peak flow and runoff volume. In the statistical analysis results, if every DEM cell size are 500m and if RADAR rainfall cell size is 30m, relevance of model was higher. Result of sensitivity assessment, high index DEM give effect to result of distributed model. Recently, rainfall -runoff analysis is used lumped model to distributed model. So, this study is expected to make use of the efficiently decision criteria for configurated models.

• The Journal of Engineering Geology
• /
• v.13 no.4
• /
• pp.429-444
• /
• 2003

Domestic marbles are mostly distributed in Gyeonggi and Yeongnam Massifs, southwest and northeast Ogcheon Belts, which belong to Precambrian, age-unknown, Cambrian-Ordovician ages, respectively. The former marbles occur as interbedded rocks in metasediments and xenoliths in granitic gneisses. Age-unknown ones occur as interbedded in the formations of Hyangsanri, Gyeomyeongsan, Hwajeonri and Munjuri, and some in metasedimentary rocks. The latter ones occur as interbedded in Pungchon Limestone, and in Jeongseon Limestone, Hwacheonri Formation and Great Limestone Group, respectively. Among physical properties, porosity shows irregular patterns to density and compressive strength, respectively. Absorption ratio has a linear pattern of positive trend to porosity, and compressive strength mostly shows a positive trend to tensile strength. Compressive strengths of the marbles are as follows : Precambrian $1,106{\;}kg/\textrm{cm}^2$, age-unknown $935{\;}kg/\textrm{cm}^2$. Cambrian $1,162{\;}kg/\textrm{cm}^2$ and Ordovician $1,560{\;}kg/\textrm{cm}^2$, respectively. Tensile strengths have decreasing trends as the above order of geologic age. In diagrams of major elements, $Al_2O_3,{\;}Fe_2O_{3(t)}{\;}and{\;}Na_2O+K_2O$ generally show positive trends with increasing $v_2$. MgO/CaO of Precambrian and age-unknown marbles have much higher values than Cambrian and Ordovician marbles as follows, Precambrian 0.31, age-unknown 0.30, Cambrian 0.03 and Ordovician 0.08. And MgO shows a negative trend with increasing CaO, which nay be caused by dolomitization. By MgO contents they can be classified into calcitic dolomite, dolomitic limestone, limestone and dolomitic limestone, respectively.

• Composites Research
• /
• v.35 no.5
• /
• pp.317-321
• /
• 2022

In this study, the PIC design method with machine learning that automatically assigning different stacking sequences according to loading types was applied bumper beam. The input value and labels of the training data for applying machine learning were defined as coordinates and loading types of reference elements that are part of the total elements, respectively. In order to compare the 2D and 3D implementation method, which are methods of representing coordinate value, training data were generated, and machine learning models were trained with each method. The 2D implementation method is divided FE model into each face and generating learning data and training machine learning models accordingly. The 3D implementation method is training one machine learning model by generating training data from the entire finite element model. The hyperparameter were tuned to optimal values through the Bayesian algorithm, and the k-NN classification method showed the highest prediction rate and AUC-ROC among the tuned models. The 3D implementation method revealed higher performance than the 2D implementation method. The loading type data predicted through the machine learning model were mapped to the finite element model and comparatively verified through FE analysis. It was found that 3D implementation PIC bumper beam was superior to 2D implementation and uni-stacking sequence composite bumper.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
• /
• v.6 no.4
• /
• pp.307-327
• /
• 2008

Geochemical study on the rocks and minerals of the Gyeongju low and intermediate level waste repository was carried out in order to provide geochemical data for the safety assessment and geochemical modeling. Polarized microscopy, X-ray diffraction method, chemical analysis for the major and trace elements, scanning electron microscopy(SEM), and stable isotope analysis were applied. Fracture zones are locally developed with various degrees of alteration in the study area. The study area is mainly composed of granodiorite and diorite and their relation is gradational in the field. However, they could be easily distinguished by their chemical property. The granodiorite showed higher $SiO_2$ content and lower MgO and $Fe_2O_3$ contents than the diorite. Variation trends of the major elements of the granodiorite and diorite were plotted on the same line according to the increase of $SiO_2$ content suggesting that they were differentiated from the same magma. Spatial distribution of the various elements showed that the diorite region had lower $SiO_2,\;Al_2O_3,\;Na_2O\;and\;K_2O$ contents, and higher CaO, $Fe_2O_3$ contents than the granodiorite region. Especially, because the differences in the CaO and $Na_2O$ distribution were most distinct and their trends were reciprocal, the chemical variation of the plagioclase of the granitic rocks was the main parameter of the chemical variation of the host rocks in the study area. Identified fracture-filling minerals from the drill core were montmorillonite, zeolite minerals, chlorite, illite, calcite and pyrite. Especially pyrite and laumontite, which are known as indicating minerals of hydrothermal alteration, were widely distributed in the study area indicating that the study area was affected by mineralization and/or hydrothermal alteration. Sulfur isotope analysis for the pyrite and oxygen-hydrogen stable isotope analysis for the clay minerals indicated that they were originated from the magma. Therefore, it is considered that the fracture-filling minerals from the study area were affected by the hydrothermal solution as well as the simply water-rock interaction.

• Science of Emotion and Sensibility
• /
• v.15 no.1
• /
• pp.87-96
• /
• 2012

This paper proposes a Image retrieval system that searches the closest images to the user's emotional need and displays images with higher ratings of color harmony from Moon-Spencer's Color Harmony Theory first. Once an emotional adjective is placed, the system searches for images with colors that contain more elements derived from Aesthetic Measure results and displays in such order. In order to test reliability of the proposed emotion retrieval method based on Moon-Spencer's Color Harmony Theory, this study compared the order of Aesthetic Measure results with the user satisfaction ratings using 200 sample images. The analysis demonstrated that the participants' average satisfaction on 15 emotion adjectives selected for the study was 5.0 on a 7-point Likert scale. Correlation analyses were performed to test the consistency the orders between Aesthetic Measure values and user satisfaction ratings. Positive correlations above R=.5 were observed in all 14 emotion words except "Clear". These findings prove the potential of the proposed emotion retrieval system based on Moon-Spencer's Color Harmony Theory to effectively reflect user emotion in such visual stimulus search as image database.

• Journal of the Korean Society of Costume
• /
• v.64 no.2
• /
• pp.126-134
• /
• 2014

This study studied female Hanbok that appeared in Korean movies in different periods, and investigated the changes and flow of the Hanbok in the movies based on the design and the form. Research scope is limited to Hanbok in Korean movies released between 1950' and 1980', and in order to study Hanbok in movies, snapshots of Korean movies for each period are used. Pictures are sourced from the Korean movie database, and forms and colors of Hanbok in the pictures are classified into 7 categories. Based on this, characteristics, changes and flow of Hanbok for each period are studied. Based on this, by investigating the Hanbok in Korean movies from silhouette and design perspectives and comparing each period, it is found that the following changes have been made: From 1950' to 1980', generally Min Jeogori (Normal Korean traditional jacket) had a higher rate. Up to early 1960', wide collar and collar strip were trends, but from 70' to 80', they have been remarkably narrowed. After liberation, ease and functional elements of western clothing were accepted. From 1950' to 80', generally wide and round shape sleeve were used. Also, from 50' to 80', normally skirt and Jeogori had the same color and fabric. Lastly. as Hanbok with western style fabric, rather than traditional Hanbok fabric was increasing, Hanbok with variously patterned fabric was shown. The lack of colored pictures led of limited research materials, and so a more accurate and sophisticated research on material and design was not possible, However, it is meaningful that this study has investigated changes and flow of Hanbok in modern Korean movies.