• Geomechanics and Engineering
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• v.28 no.5
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• pp.463-475
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• 2022

In the mine exploitation stage; one of the critical issues is the stability assessment of post-pillars. The instability of post-pillars leads to serious safety hazards in mining operations. The focus of this study is to assess the stability of post-pillars in the 130# stope in the central ore body at Trepça hard rock mine by employing both conventional (i.e., critical span curve) and numerical methods (i.e., FLAC3D). Moreover, a new numerical based index (i.e., Pillar Yield Ratio-PYR) was proposed. The aim of PYR index is to determine a border line between stable, potentially unstable, and failure state of post-pillars at a specific mine site. The critical value of pillar width to height ratio is 2.5 for deep production stopes (e.g., > 800 m). Results showed that pillar size, mining height and mining depth significantly have affected the post-pillar stability. The reliability of numerical based index (i.e., PYR) is verified based on empirical underground pillar stability graph developed by Lunder, 1994. The proposed pillar yield ratio index and pillar stability graph can be used as a design tool in new mining areas at Trepça hard rock mine and for other situations with similar geotechnical conditions.

• Journal of the Korean Chemical Society
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• v.44 no.4
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• pp.328-336
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• 2000

The pulsed-delayed extraction (PDE) in linear time-of-flight mass spectrometer(TOF MS) is characterized on the enhancement of resolution, mass-depth of focus and effect of instrumentahan 2000. The ion signals separate isotopically by up to molecular weight of 2500 in instrumental broadening of 5 ns, which is a good agreement with calculation. The fragmentation paths of PPG can be sug-gested by the isotopica distributions of fragment series produced when PPG desorbed from graphite surface.

• Korean Institute of Interior Design Journal
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• v.22 no.4
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• pp.41-51
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• 2013

Lately in many cases, Spaces are designed by stimulating user's sensibility, emotion, psychological software over based on the user behavior and purpose of space. Because space is not only practical using and use purpose but also the place for expressing ourselves by experiences. But space is a physical thing. so we need to arrange a structure of abstract and formless source of design by sophisticated grammaticalization. Especially storytelling of that abstract thing have characteristics of relation, process among users and space. because storytelling is focused on the discourse of stories and relationship record of that discourses. So this is used by expression device for user's emotion things and subjects in numerous cases. And storytelling is the basic, important element for user's experience in a space. By the way, Overlapping is also basic element for being possible to make experiences by concrete thing. that is because, Overlapping is layering phenomenon of some objects. Overlapping is made distance, distance make depth, and this relations take us an experience. Finally storytelling, Overlapping and space of experience are relation of cause and effect. So in this thesis, researcher looks for the relation characteristics between storytelling and overlapping by experience. and makes the abstract source into concrete and sophisticated formular.

• Women's Health Nursing
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• v.12 no.2
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• pp.124-131
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• 2006

Purpose: The purpose of this study was to examine the perceptions regarding the use of Emergency Contraceptive Pills (ECPs) among young Korean women. Method: The study included 14 unmarried women aged 19 to 34 years (mean, 25 years). Data was collected by focus group interviews and an in-depth interview from July to November, 2005. Content analysis was conducted. Result: The four major themes that emerged were control of accessibility, safety concern, lack of knowledge and information, and ambivalence. Control of accessibility: Most of the participants stated a prescription is necessary although they might feel ashamed if they had to ask for an ECP. Safety concerns: Participants thought that taking an ECP would be harmful to their body. Lack of knowledge and information: Most of the participants felt that they did not know enough about ECPs and were willing to learn more. Ambivalence: The participants stated that they would take an ECP when needed and would recommend it to a friend although they were concerned about the risks of ECPs. Conclusion: The results from this study suggest the need for an educational and awareness program to empower women to be able to make informed decisions on ECPs when needed.

• Proceedings of the Korean Society Of Semiconductor Equipment Technology
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• 2006.10a
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• pp.132-137
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• 2006

With the help of the development of digital-multimedia in the middle of 1990's, FDP(Flat Panel Display) had attracted considerable attention. Collimation proximity exposure system that transfers the pattern on wafer or glass exactly using mask and light with appropriate wavelength is core process in semiconductor and liquid display element. The performances of resolution required in precision exposure system are evaluated by resolving power, depth of focus and storage area. Most of development has targeted on these three factors. The optical design including lamp house has played an important role on the performance of exposure process. In this study, we evaluate the cooling system, concerning on exposure device with mercury lamp among the kernel equipment for the production of LCD, to prevent the instability of lighting due to long term accumulation of excessive heating inside the lamp house. Numerical analysis is conducted on full-scale model. The characteristics of three-dimensional flow, pressure and temperature distribution on exposure system are graphically depicted to estimate the whole cooling system for lamp house and to establish the design criteria.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.32B no.6
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• pp.886-898
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• 1995

One of the ways to measure the distance in the computer vision is to use the focus and defocus. There are two methods in this way. The first method is caculating the distance from the focused images in a point (MMDFP: the method measuring the distance to the focal plane). The second method is to measure the distance from the difference of the camera parameters, in other words, the apertures of the focal planes, of two images with having the different parameters (MMDCI: the method to measure the distance by comparing two images). The problem of the existing methods in MMDFP is to decide the thresholding vaue on detecting the most optimally focused object in the defocused image. In this case, it could be solved by comparing only the error energy in 3x3 window between two images. In MMDCI, the difficulty is the influence of the deflection effect. Therefor, to minimize its influence, we utilize two differently focused images instead of different aperture images in this paper. At the first, the amount of defocusing between two images is measured through the introduction of regularization and then the distance from the camera to the objects is caculated by the new equation measuring the distance. In the results of simulation, we see the fact to be able to measure the distance from two differently defocused images, and for our approach to be robuster than the method using the different aperture in the noisy image.

• Research in Community and Public Health Nursing
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• v.23 no.1
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• pp.51-62
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• 2012

Purpose: The purpose of this study was to identify community health nursing activities that community health practitioners perceive and their achievements in community by reviewing the community health nursing activities that community health practitioners have done for the last 30 years. Methods: This study was a qualitative study. Thirty one community health practitioners were interviewed using the focus group interview method and data were analyzed using content analysis. Data were collected from April to June in 2011. Results: Community health practitioners perceived themselves as "Community Vitalizers" and 9 categories were identified. They were 'ground to explore new nursing areas', 'assimilation to community', 'ground to establish community diagnosis', 'everyday life health management in the community', 'increased accessibility to medical services for the residents', 'enforced health practices for the residents', 'reinforced self-reliance of community', 'commitment to making a happy village' and 'mental fence of the community.' Conclusion: This study was meaningful in that it explained the unique identity of the community health practitioners and could be used as important basic materials in the process of re-establishment of the roles of Health Offices. Hereafter in-depth study on community competence reinforcement should be made to identify the roles of community health nurses.

• Human Ecology Research
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• v.58 no.2
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• pp.201-214
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• 2020

This study researched the life experiences of 30-40's voluntary single women. Currently, a growing number of women in their 30s and 40s in South Korea are voluntarily choosing single life to achieve self-realization and focus on their lives. We want to take note of this phenomenon and take an in-depth the lives of voluntary single life beings they are experiencing by using hermeneutic phenomenological study method of Van Manen. The results of this study are as follows. First, 30-40s voluntary single women have experienced desire of self-realization through their single life. Second, they were satisfied with their lives based on the concept of having free choices, stable social support and they social-economic base. Third, they have experienced a low awareness of single life in society and many people. Last, they were preparing for their future lives for their physical health, finances, and role as parents' provider. This study provides a better understanding of the lives of 30-40s voluntary single women.

• The Mathematical Education
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• v.50 no.1
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• pp.89-102
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• 2011

The purpose of this study is to diagnose the problems of mathematics education in Korea by conducting an in-depth analysis of international comparative studies, a Delphi method, and a survey. Further analysis of TIMSS and PISA results also reveals several negative aspects of mathematics education practice in Korea. The mathematics education experts' opinions collected by Delphi method were classified into 12 categories: private education and test-driven education, curriculum and textbooks, lessons, evaluation, teacher, learner, teaching aid and facilities. affective aspects of mathematics, discrepancy between a theory and a practice, preservice/inservice teacher education and teacher employment test, education policy, and overall. Another survey was conducted to focus more on the development of curriculum which is a pending issue. Considering the fact that mathematics education should contribute to improve practical aspect as well as elaborate theoretical aspect, this study lays a foundation of improvement of mathematics education in Korea.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.27 no.6
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• pp.773-780
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• 2003

The three-dimensional spatial structures of impeller flow created by a six bladed Rushton turbine have identified based on the volumetric velocity information from multi-plane stereoscopic PIV measurements. A total of 10 planes with 2 mm space and a 50 mm by 64 mm size of the field of view were targeted. To reduce the depth of focus, we adopted an angle offset configuration which satisfied the Scheimpflug condition. The distortion compensation procedure was utilized during the in situ calibration. Phase-locked instantaneous data were ensemble averaged and interpolated in order to obtain mean 3-D. volumetric velocity fields on a 60 degree sector of a cylindrical ring volume enclosing the turbine blade. Using the equi-vorticity surface rendering, the spatial structure of the trailing vortices was clearly demonstrated. Detail flow characteristics of the radial jet reported in previous studies of mixer flows were easily identified.