• 한국해양학회지
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• v.30 no.4
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• pp.271-278
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• 1995

A study of heavy mineral sands in terms of heavy mineral group and concentration has been carried out by analyzing 88 grab samples from the continental shelf off the southeast coast of Korea. Heavy mineral groups seem to be outlined and classified into four regions in the study area: 1) the western region; high concentrations of stable minerals, such as opaque mineral, magnetite, garnet and ZTR, 2) Korean Trough region; moderate concentrations of stable minerals, 3) the eastern region; abundant altered mineral and amphibole with minor of pyroxene concentration, and 4) the northeastern shelf-break region; low concentration of stable minerals with abundant altered minerals. The sedimentologic natures of four major heavy mineral regions (groupings) seem to be influenced by physical, dynamic and hydraulic milieu and also aerial and/or subaqueous weathering processes. It seems to be, further, plausible that shallow marine waves and currents associated with neritic dynamic condition of transgressive sea might be very effective on the concentration and groupings (sorting) of heavy min-erals in the surficial sediments of the continental shelf. The pyroxene-abundant heavy mineral suite (group), in fact, seems to suggest a sediment source from Japanese Islands.

• Journal of the Korean Magnetics Society
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• v.21 no.6
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• pp.193-197
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• 2011

The thickness dependence of the magnetic switching volumes in electrodeposited CoPt films was investigated from the magnetization reversal and the magnetic interaction behavior. As the sample thickness is increased, the field difference between the wall pinning field ($H_{DW}$) and the nucleation field ($H_N$) as well as the absolute value of ${\Delta}$area are increased. Therefore, the decrement tendency of the switching diameter with increasing sample thickness can be well explained by the domain wall motion controlled by the domain wall pinning and the strength of dipolar interaction.

• The Journal of the Acoustical Society of Korea
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• v.38 no.2
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• pp.168-176
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• 2019

When an array receives a signal with a frequency higher than the design frequency, there is an ambiguity in beamforming due to spatial aliasing. In order to overcome this problem, Abadi proposed frequency-difference beamforming. However, there is a constraint that the minimum frequency bandwidth is required according to the value of the difference frequency. In this paper, we propose a method to find the direction of the target signal with spatial aliasing based on the frequency-wavenumber spectrum combined with Radon transform. The proposed method can estimate the direction of the target without ambiguities when the signal has nonnegligible bandwidth. We tested the algorithm by simulating a broadband signal and verified the results with the frequency-difference beamforming method using SAVEX15 (Shallow Water Acoustic Variability EXperiment 2015)'s shrimp noise data.

• Korean Journal of Applied Biomechanics
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• v.12 no.2
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• pp.245-257
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• 2002

The purpose of this study was to develop a simple, valid, and reliable instrument for measuring forward flexion of trunk-hip joint. The subject included 44 females for sports major of volunteers at D. Women's University. In establishing the validity, objectivity the reliability of the new flexibility test(NF-test) for trunk-hip joint, Takei- flexometer(modified Leighton flexometer) was administered as the reference instrument, and test-retest method was utilized with the best scores. Intraclass correlation coefficient was obtained to use two way-mixed effect model and this value was average measure. The Pearson product correlation coefficient of L in this study were; the new flexibility test and Takei-flexometer as the reference tool correlated r = .962 in the first test, r = .960 in the second test. The intraclass correlation coefficient of the new flexibility test between in the initial test and in the retest were R = .994 for L, R =.993 for Y, and the intraclass correlation coefficient of the new flexibility test between L and Y were R =.985 in the initial test, and R =.986 in the retest. Based on the above findings, the following conclusions are presented. It was found the new flexibility test (NF test) was a valid, reliable, objective tool for measuring forward flexion of trunk-hip joint, and possible to be recommended as he test for measuring trunk-hip flexibility in the field.

• 한국해양학회지
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• v.30 no.3
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• pp.170-183
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• 1995

Eddies and surface current field in the southwestern part of the East Sea were investigated using satellite-tracked drifters, CTD, and ADCP from November 1992 to September 1993. Trajectories of surface drifters provided information for the first time on the meandering motion of the East Korean Warm Current in the Ullung Basin (referred as UB) and clearly indicated the existence of cyclonic and anticyclonic eddies of various scales. Anticyclonic eddies persisting for a relatively long period were observed in UB and the southwestern corner of the Northern (Japan) Basin (SNB), while a cyclonic eddy was found in the coastal area between Sokcho and Donghae during the summer. Analysis shows that the eddy in UB behaved as a stationary eddy at least during the observation period and the cyclonic eddy was closely related to the existence of a cold water mass. The anticyclonic eddy in SNB was larger than that in UB, but much elongated in shape. The eddy in UB is characteristic of major and minor axes of about 120 and 70 km, revolution period of 13.6 days, mean swirl velocity of about 24 cm/s, and mean eddy kinetic energy of 392 cm$\^$2//s$\^$2/. The eddy in SNB is described as follows; major and minor axes of 168 and 86 km, period of 14.9 days, mean swirl velocity of 29 cm/s and mean eddy kinetic energy of 629 cm$\^$2//s$\^$2/. The mean translational speed is about 3 cm/s for both eddies. The agreement of the surface current pattern in UB observed by ADCP with the geostrophic flow pattern may suggest that the eddy in UB was nearly in geostrophic balance. The eddy was found to be strongly bottom-controlled.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.2 no.3
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• pp.189-199
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• 2004

A bridge transported servo manipulator (BTSM) system for the advanced spent fuel conditioning process (ACP) has been developed to overcome the limitation of access, which is a drawback of mechanical master-slave manipulators (MSM) for the equipment maintenance. The servo manipulator is composed of a slave manipulator attached to the telescoping tubesets equipped with the overhead bridge installed at a hot cell and a master manipulator installed at an out-of-hot cell. Each manipulator has 7 degrees-of-freedom (DOF): a body rotation, an upper-arm tilt, a lower-arm tilt, a lower-arm rotation, a wrist pan & tilt, and a grasp motion. A wire-driven mechanism for a lower-arm rotation, a wrist pan and tilt, and a grasp motion of the manipulator has been adopted to increase the handling capacity compared to the manipulator weight and decrease the friction. The main disadvantage of the wire-driven mechanism is that if one link is in motion, other links can be affected. In this paper, the transmission characteristics among the wire-driven links have been formulated to overcome this drawback. The unexpected behaviors are confirmed by analyses of transmission characteristics as well as experiments. Also, the experimental results show that the unexpected behaviors are greatly decreased by the proposed compensation equations.

• Korean Journal of Applied Biomechanics
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• v.24 no.2
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• pp.181-187
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• 2014

In this study, a real-time evaluation system for quantitative dynamic fitting during pedaling was developed. The system is consisted of LED markers, a digital camera connected to a computer and a marker detecting program. LED markers are attached to hip, knee, ankle joint and fifth metatarsal in the sagittal plane. Playstation3 eye which is selected as a main digital camera in this paper has many merits for using motion capture, such as high FPS (Frame per second) about 180FPS, $320{\times}240$ resolution, and low-cost with easy to use. The maker detecting program was made by using Labview2010 with Vision builder. The program was made up of three parts, image acquisition & processing, marker detection & joint angle calculation, and output section. The digital camera's image was acquired in 95FPS, and the program was set-up to measure the lower-joint angle in real-time, providing the user as a graph, and allowing to save it as a test file. The system was verified by pedalling at three saddle heights (knee angle: 25, 35, $45^{\circ}$) and three cadences (30, 60, 90 rpm) at each saddle heights by using Holmes method, a method of measuring lower limbs angle, to determine the saddle height. The result has shown low average error and strong correlation of the system, respectively, $1.18{\pm}0.44^{\circ}$, $0.99{\pm}0.01^{\circ}$. There was little error due to the changes in the saddle height but absolute error occurred by cadence. Considering the average error is approximately $1^{\circ}$, it is a suitable system for quantitative dynamic fitting evaluation. It is necessary to decrease error by using two digital camera with frontal and sagittal plane in future study.

• Journal of Korean Ophthalmic Optics Society
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• v.15 no.2
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• pp.175-183
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• 2010

Purpose: This study investigated the impact of ametropia and myopia on health-related quality of life (QoL) measures in elementary schoolers. Methods: Elementary school children of 92 aged 12 to 13 were divided into emmetropia and myopia groups by spherical equivalent. Then myopia was classified into the low, moderate and high myopia groups. Vision-related QoL scores were determined using PedsQL 4.0 (Pediatric Quality of Life Inventory) with physical health (8 items), emotional functioning (4 items), social functioning (5 items) and school functioning (5 items). Results: The total QoL score in the myopia group appeared lower than that in the emmetropia group, however the difference was not statistically significant (p>0.05). When it comes to physical health (running or exercising) and social functioning (getting along with friends or being teased)-related questions, the QoL score in myopia was low compared with the emmetropia group (p<0.05). High myopia showed a low score in physical health items but there was no significant difference in overall QoL scores in comparison with other groups (p<0.05). Conclusions: Refractive errors does not have a great impact on the total health-related QoL in elementary school children but it causes discomfort in physical health and social functioning.

• Journal of the Korean Institute of Landscape Architecture
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• v.41 no.4
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• pp.85-101
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• 2013

The primary goal of this research is to link two currently disconnected literature; the history of urban redevelopment and the one of urban parks and open spaces in the United States (US). Through this exercise, this study attempts to reveal examples of urban parks and open spaces that have yielded economic effects, and emphasize their possibility as a measure of urban redevelopment. Five phases are presented, starting with two Pre-World War II urbanization periods, and three subsequent periods of Post-World War II urban redevelopment (1940s~1960s, late 1960s~1970s, 1980s~present). While urban parks in the 19th century urbanization period held a preeminent place in urban design, policy and economy, ensuing depression and World War II diminished their role as a channel to ease unemployment. In the first phase of urban redevelopment, the economic motive to build open space was to boost the appeal of specific locales in order to draw people and businesses back to a neglected city. In the second phase, public effort to create and maintain urban parks and open spaces declined due to the budget austerity, instead, community open spaces flourished through the voluntary actions and helped neighborhoods to regain desirability. In the third phase, the aspirations and functions of such projects resemble their forerunners of the first phase, but their targets extended to global businesses and elites.

• 한국노년학
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• v.32 no.3
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• pp.819-834
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• 2012

The purpose of this study was to examine the degree of successful aging and to investigate influencing factors of it in elderly to types of gender. Subjects were 73 male elderly and 77 female elderly, total 150 elderly living at K city in C province, from May to June, 2012. The data were analyzed using the SPSS Win 18.0 program for $X^2$ test, t-test, Pearson's correlation coefficients and multiple regression analysis. The correlated factors of successful aging among male elders included life satisfaction(r=.525, p<.001), family support(r=.355, p=.004), depression(r=-.555, p<.001) and loneliness(r=-.437, p<.001). Those of successful aging among female elders included life satisfaction(r=.607, p<.001), leisure satisfaction(r=.679, p<.001), family support(r=.784, p<.001), depression(r=-.516, p<.001), loneliness(r=-.644, p<.001) and self-transcendence(r=.576, p<.001). Life satisfaction and depression were statistically significant influencing factors of successful aging in male elders. Especially in the cases of female elders, life satisfaction, depression, family support and self-transcendence affected to successful aging. Life satisfaction, depression, family support, and self-transcendence were explained 52.9% in perception of successful aging among elders. This study suggests that life satisfaction, depression, family support, and self-transcendence will be considered in enhancing the successful aging promoting care and welfare designed for types of gender.