• Journal of Korean Society on Water Environment
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• v.24 no.3
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• pp.365-377
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• 2008

Large artificial dam reservoirs and associated downstream ecosystems are under increased pressure from long-term negative impacts of turbid flood runoff. Despite various emerging issues of reservoir turbidity flow, turbidity modeling studies have been rare due to lack of experimental data that can support scientific interpretation. Modeling suspended sediment (SS) dynamics, and therefore turbidity ($C_T$), requires provision of constitutive relationships ($SS-C_T$) and accounting for deposition of different SS size fractions/types distribution in order to display this complicated dynamic behavior. This study explored the performance of a coupled two-dimensional (2D) hydrodynamic and particle dynamics model that simulates the fate and transport of a turbid density flow in a negatively buoyant density flow regime. Multiple groups of suspended sediment (SS), classified by the particle size and their site-specific $SS-C_T$ relationships, were used for the conversion between field measurements ($C_T$) and model state variables (SS). The 2D model showed, in overall, good performance in reproducing the reservoir thermal structure, flood propagation dynamics and the magnitude and distribution of turbidity in the stratified reservoir. Some significant errors were noticed in the transitional zone due to the inherent lateral averaging assumption of the 2D hydrodynamic model, and in the lacustrine zone possibly due to long-term decay of particulate organic matters induced during flood runoffs.

• Proceedings of the Botanical Society of Korea Conference
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• 1987.07a
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• pp.191-211
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• 1987

Common usage of the concept of juvenility implies that there is one physiological phase, the juvenile phase, which manifests itself in the various morphological and physiological phenomena observed in juvenile higher plants. The juvenile phase is often defined as that time from seed germination until the plant attains the ability to flower regulating such behaviour. This definition precludes plants from flowering in the juvenile phase. It is of major interest, therefore, to identify the physiological controls(Bluehreife) regulating such behavior. The length of the juvenile period in higher plants ranges from one year to over 60 years in different species. The long juvenile period of seedling is the main cause of the long duration of the breeding process. I determined the length of the juvenile period in various plants and its control of phase changes in natural system in relation to factors such as plant size and age, shoot morphology, apex size, root system and phytohormonal and nutritional status is reviewed. From the own experimental and observational evidence available it appears that both hormonal and nutritional factors can be involved in control of juvenility but that a specific juvenile or flowering hormone is not involved. Grafting, ringing, scoring, root pruning and fertilization have been used to accelerate flowering, but in most cases these cultured treatments are only successful on plants that were passed the juvenile phase. It is suggested that there are intrinsic difference between the meristematic cells of the apieces of juvenile and adult shoot, which are thus determined with respect to there development potentialities. The problems associated with the maintenance of the determined state through mitosis are discussed. The properties of transitional forms of Ribes nigrum L. intermediate between the juvenile and adult phase, are descrived and there implications discussed. Analogies are drawn between juvenile phenomena in woody perennials and in herbaceous species.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.37 no.1
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• pp.17-24
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• 2024

This paper assesses the structural performance of the Daeungbojeon Hall of Magoksa in Gongju, a representative multi-tiered roof traditional timber structure from the Joseon Dynasty, under vertical loads. Employing midas Gen, a structural analysis software, we developed a three-dimensional analysis model closely resembling the actual structure. Static analysis was employed to evaluate the safety and serviceability of the main vertical and horizontal members under vertical loads. While all members met the safety and serviceability criteria, structural weaknesses were identified in the Daelyang of the lower floor, particularly as a transitional beam, necessitating improvement. For the evaluation of dynamic behavior characteristics, eigenvalue analysis was conducted, assuming a relative rotational stiffness of 5% at the main joints. The natural period was determined to be 1.105 seconds, placing it within the category of a Hanok of similar size. The first mode manifested as a translational movement in the forward and backward direction of the building.

• Journal of the Korean Geotechnical Society
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• v.36 no.11
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• pp.97-106
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• 2020

Swelling properties and shear strength behavior of MgO-Sand mixtures with hydration procese of MgO are compared according to different MgO contents (W_MgO/W_Total=0, 30, 50, 70, 100%) in this study. The specimens are prepared by mixing with crushed MgO refractory bricks and silica sand. After hydration, the particle size and the specific gravity of MgO were decreases. Through microstructure observation and X-ray diffraction analysis, it is confirmed that MgO changes from the cubic structure of Periclase to the hexagonal cubic structure of Brucite after hydration. As the MgO content increases, both swelling rate and swelling pressure of the mixtures increase. W_MgO/W_Total=30% specimen shows relatively low swelling pressure and swelling rate because produced Mg(OH)₂ mainly fills the pores between sand particles. However, in the case of MgO more than 50%, swelling pressure and swelling rate increase significantly because Mg(OH)₂ fills the pores of sand particles at first and then either pushes out sand particles or Mg(OH)₂ particles after filling the pores. As a result of the direct shear test, before hydration, the mixtures show a dilative behavior on high MgO contents and a contractive behavior on low MgO contents. However, after hydration, the behavior of all mixtures changes to contractive behavior. The threshold fraction of fine (i.e., Mg(OH)₂) contents of the hydrated MgO-Sand mixtures reveals approximately 60% compared with normalized shear strength.

• Journal of the Korean Society for Library and Information Science
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• v.40 no.1
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• pp.13-37
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• 2006

Using Grounded Theory. the present study was to discover structure and process of pregnant women's information seeking experience through identifying concepts and relationships of the experience. In-depth interviews were conducted with 16 Participants selected by theoretical sampling. The findings were : 1) Pregnant womens' information seeking was caused by Acceptance of Pregnancy . 2) The phenomenon of information seeking was for Maintaining Normalcy to Pregnancy(MNP), 3) MNP occurred in connection with Perceived Anxiety and Desire to Know 4) Action/interaction Strategies to MNP were related to the Awareness of Ways Acquiring Information. Previous Knowledge. Self-Regulation, and Information Access Environment. 5) Action/interaction Strategies to MNP were Seeking Diagnostic Data of Antenatal Care. Seeking Standard Knowledge. Seeking Experience. and Seeking Emotional Support. 6) As consequences of taking strategies, pregnant women were experienced in Sufficient. or Insufficient. 7) A three-stage process of information seeking was discovered : Comparing, Contextualising, Making sure. 8) In terms of change of information needs during pregnancy, a four-phasic process was discovered. Acceptance Phase. Adjusted Phase, Focusing Phase, and Transitional Phase. Based upon these results. it needs to generate a substantive theory contributed to holistically explain and predict pregnant women's information seeking behavior.

• Journal of the Korean Geotechnical Society
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• v.27 no.9
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• pp.13-24
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• 2011

The renowned Terzaghi's one-dimensional consolidation theory is not applicable to quantification of time-rate settlement for highly deformable soft clays such as dredged soil deposits. To deal with this special condition, a non-linear finite strain consolidation theory should be adopted to predict the settlement of dredged soil deposits including self-weight and surcharge-induced consolidation. It is of importance to determine the zero effective stress void ratio ($e_{00}$), which is the void ratio at effective stress equal to zero, and the relationships of void ratio-effective stress and of void ratio-hydraulic conductivity for characterizing non-linear finite strain consolidation behavior for deformable dredged soil deposits. The zero effective stress void ratio means a transitional status from sedimentation to self-weight consolidation of dredged soils. In this paper, laboratory procedures and equipments are introduced to measure such key parameters in the non-linear finite strain consolidation analysis. In addition, the non-linear finite strain consolidation parameters of the Incheon clay and kaolinite are evaluated with the aid of the proposed methods in this paper, which will be used as input parameters for the non-linear finite strain consolidation analyses being performed in the companion paper.

• Research in Community and Public Health Nursing
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• v.11 no.1
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• pp.127-145
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• 2000

The objectives of this study are to identify health behaviors and health problems. and the relations between health behaviors and health problems of female workers in the retail business. The number of subjects were 200 female workers of 6 department stores in Seoul and Kyonggi area, whose jobs last more than 6 months as retail employees. The data was collected during 2 months from July 1 to August 30, 1998. The Cornell Medical Index Health Questionnaire(CMI) was used to measure their health problems, while health behaViorn were investigated in terms of 'smoking', 'alcohol', exercise', 'diet', and 'sleeping'. The data were analyzed with frequency. percentage, t-test, ANOVA test, and $X^2-test$ by SPSS PC+ program. The results of this study are as follows: 1. Out of health problems. Digestive symptoms occupied the highest percent number. nervous ones the second and cardiovascular ones the third among physical health problems of retail female workers. The most frequent mental health problem was 'adequacy' and the next, 'tension' and 'anger', 2, Health problems according to general characteristics of subjects were shown that the younger or the unmarried complained more than the older or the married, especially in the items of 'eye and ear', 'respiratory system', 'cardiovascular system', 'digestive tract', 'nervous system', 'adequacy', and 'depression'. The longer working duration they have had, the more they complained of 'respiratory system' and 'adequacy'. The lower academic careers complained of 'nervous' than the higher ones with statistical significance. 3. The analysis of daily health clinic notes showed that respiratory complaints were the highest percent, successively followed by digestive tract, nervous one, external injury, musculoskeletal system, urinary-reproductive system and others. 4. The level of their health practice was generally low in smoking, diet habit and alcohol intake, exercise, sleeping, very low especially in smoking, diet, alcohol intake, and exercise among them all. 5. Present smokers and ones with past experience complained of physical and mental health problems of 'respiratory system', 'digestive tract', 'skin', 'nervous', 'urinary-reproductive system', 'fatigability', adequacy', 'depression', 'anxiety', 'anger' and 'tension', than non smokers, with statistical difference. Workers without having breakfast and with irregular diet had more complaints on 'digestive tract', 'adequacy' and 'tension', than those who had regular dietary habit. The less the subjects slept, the more they complained of eye and ear, cardiovascular system. The subjects who drank alcohol complained more digestive problem. However, whether they exercise or not did not affect physical and mental health problems in a significant manner. 6. The subjects' age and marital status were statistically significant relating to health behaviors, as the younger or unmarried recorded a low level of health practice in smoking, drinking, dietary habit. Based on the results, the suggestions are made as follows: 1. Health education program on smoking, alcohol intake, diet habit is needed to improve health problems and health behavior of female retail workers. 2. The unmarried workers of late teen and twenties, who are transitional period from teenagers to adulthood are important targets for health promotion program especially for maternal health. 3. Better working environment with sufficient time and facilities for workers to relax is required to promote female sales workers' health. 4. Further research is required to identify the relation between workers' visual fatigue and intense lights for the display of goods.