• The Journal of Engineering Geology
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• v.30 no.2
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• pp.147-160
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• 2020

Unsaturated hydraulic conductivity of near-surface unconsolidated layers depends on the physical properties and water content of the unconsolidated layers. So far, many studies have been conducted on the unsaturated hydraulic conductivity of near-surface unconsolidated layers. However, researches on hydraulic conductivity of unsaturated fractured rocks have been relatively rare. In relation to the construction of a low/intermediate level radioactive waste surface-disposal facility, this study compared and analyzed van Genuchten parameters (α, n) in the laboratory and the hydraulic conductivity obtained in field tests for fractured hornfels at a radioactive-waste disposal site of Korea. The relationship between the field hydraulic conductivity and van Genuchten parameters using data from the ten depth intervals of three boreholes resulted in that the correlation coefficient (R) between the hydraulic conductivity and the van Genuchten parameter α was 0.7607, showing positive correlation whereas the R between the hydraulic conductivity and the van Genuchten shape-defining parameter n was -0.8720, showing negative correlation. Hence, this study confirmed the relationship between the field hydraulic conductivity and the van Genuchten unsaturated functions for the unsaturated fractured hornfels.

• Korean Journal of Applied Biomechanics
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• v.16 no.1
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• pp.101-108
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• 2006

The purpose of this study was to compare GRF characteristics during walking wearing jogging and roller shoes. Twelve male middle school students (age: $15.0{\pm}0.0\;yrs$, height: $173.6{\pm}5.0\;cm$, weight: $587.6{\pm}89.3\;N$) who have no known musculoskeletal disorders were recruited as the subjects. Kinematic data from six S-VHS camcorders(Panasonic AG456, 60 fields/s) and GRF data from two force platform; (AMII OR6-5) were collected while subjects walked wearing roller and jogging shoes in random order at a speed of 1.1 m/s. An event sync unit with a bright LED light was used to synchronize the video and GRF recordings. GRF data were filtered using a 20 Hz low pass Butterworth. digital filter and further normalized to the subject's body weight. For each trial being analyzed, five critical instants and four phases were identified from the recording. Temporal parameters, GRFs, displacement of center of pressure (DCP), and loading and decay rates were determined for each trial. For each dependent variable, paired t-test was performed to test if significant difference existed between shoe conditions (p <.05). Vertical GRFs at heel contact increased and braking forces at the end of initial double limb stance reduced significantly when going from jogging shoe to roller shoe condition. Robbins and Waked (1997) reported that balance and vertical GRF are closely related It seems that the ankle and knee joints are locked in an awkward fashion at the heel contact to compensate for the imbalance. The DCP in the antero-posterior direction for the roller shoe condition was significantly less than the corresponding value for the jogging shoe condition. Because the subjects tried to keep their upper body weight in front of the hip to prevent falling backward, the DCP for the roller shoe condition was restricted The results indicate that walking with roller shoes had little effect on temporal parameters, and loading and decay rates. It seems that there are differences in GRF characteristics between roller shoe and jogging shoe conditions. The differences in GRF pattern may be caused primarily by the altered position of ankle, knee, and center of mass throughout the walking cycle. Future studies should examine muscle activation patterns and joint kinematics during walking with roller shoes.

• Journal of Digital Convergence
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• v.15 no.12
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• pp.581-590
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• 2017

This study was conducted to investigate the perception of nurse's use of physical restraints. This study is a descriptive research study for 138 nurses who work at the small hospitals under 300 beds. Statistical analysis was performed using descriptive statistics, t-test, ANOVA, and factor analysis using the SPSS statistical program. The results of this study were as follows: The overall average of the nurses' perception of physical restraint was $3.91{\pm}0.54$, and the most important reason for using a physical restraint was to protect the patient from falling out of bed($4.37{\pm}0.68$). The factor analysis showed that 'behavior, psychological symptom management($3.81{\pm}0.67$)', 'maintain medical treatment($4.11{\pm}0.60$)' and 'patient safety($4.13{\pm}0.63$)'. It is necessary to understand the characteristics and factors of nurse's use of physical restraint in small and medium hospitals. Moreover, it is also required to use minimum physical restraints for patient's safeties and rights based on accurate understanding of physical restraint's use. Therefore, it is needed to provide job training for the physical restraint that is used in various situations and to develop education and intervention program to adjust in nurses' situation.

• Journal of the Korea Concrete Institute
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• v.22 no.2
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• pp.237-245
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• 2010

Recently, deflection of the slab during construction periods becoming one of the important issues because of increasing the large-span structures. Early removing the form and support of the slab to achieve the rapid construction cause falling-off in quality of the structures. To reduce these deterioration and make rapid construction, construction of strength and stiffness gain model is needed by the research about the early-age concrete properties. Previous research results indicated that concrete model in existing design codes could not provide the mechanical properties of early age concrete. This paper carried out the concrete compressive strength tests on the curing age at early age stage. Evaluation of the accuracy of compressive strength and modulus of elasticity gain formula in existing various design codes was performed based on this test results, and new design model was proposed. This new model will be useful to develop the new rapid construction methods or prevent the deterioration of the deflection at construction periods. Material tests were performed at 1, 3, 7, 14, 28 curing days, total 159 cylinder style specimens were tested. Based on analyzing the test results, the relationship between compressive strength and modulus of elasticity at early age was proposed.

• Journal of Trauma and Injury
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• v.20 no.1
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• pp.12-18
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• 2007

Purpose: Recently, trauma is more frequent due to the increases in the population, the number of traffic accident, and the incidence of violence. Especially, abdominal trauma is a leading cause of morbidity and mortality. We analyzed the clinical features and the factors associated with morbidity and mortality. Methods: We analyzed 136 patients of abdominal trauma who were admitted at the Department of Surgery, Chonnam National University Hospital, from January 2003 to June 2005. We analyzed the cause of trauma, the injured organ, combined injuries, mental status, blood pressure, laboratory findings, morbidity, and mortality. The relationships between by variable were assesed by using the independent samples test and the Kruskal?Wallis test. Results: The causes of trauma were traffic accidents (98 cases, 72%), falling accidents (9 cases, 6.6%), violence (6 cases, 4.4%), and stab injuries (6 cases, 4.4%). The injured organs were the small intestines (47 cases, 34.6%), the liver (35 cases, 25.7%), the spleen (26 cases, 19.1%), the mesentery (17 cases, 12.5%), the large intestines (15 cases, 11.0%), the pancreas (14 cases, 10.3%), etc. The most common combined injury was chest injury (53 cases, 39%). Comatose or semicomatose mental status and shock on admission (<60 mmHg in systolic) were related to high mortality (85.7%). In laboratory findings, decreased hemoglobin (<8 g/dL), and platelet count (<$50,000/mm^3$), and increased creatinine level (>1.6 mg/dL) were significant prognostic factors. The incidence of postoperative complications was 40.4%, and frequent complications were wound infection (8.1%) and re-bleeding (8.1%). The overall mortality rate was 18.4%, and most common cause was hypovolemic shock (18 cases, 13.2%), however, there was no statistical difference according to injurd organ. Conclusion: In the multivariate analysis, mental status, hemoglobin, and serum creatinine level were the most significant prognostic factors. When an abdominal trauma patient arrives at the emergency room, a rapid and accurate evaluation of the patient's status and risk factors, and resuscitation, if necessary, have to be performed to lower the morbidity and mortality.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.32 no.5
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• pp.212-217
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• 2022

Large thermal stress due to the difference between silicon carbide and graphite's coefficients of thermal expansion could be formed during crystal growing process of silicon carbide (SiC) at high temperature. The large thermal stress could separate the SiC seed crystals from graphite components, which bring about the drop of the seed crystal during crystal growth. However, the bonding properties of SiC seed crystal module has hardly reported so far. In this study, SiC and graphite were bonded using 3 types of bonding agents and a three-point bending tests using a mixed-mode flexure test were conducted for the bonded samples to evaluate the bonding characteristics between SiC and graphite. Raman spectroscopy, X-ray Photoelectron Spectroscopy, and X-ray Computed Tomography were used to analyze the bonding characteristics and the microstructures of the SiC-graphite interfaces bonded with the bonding agents. As results, an excellent bonding agent was chosen to fabricate SiC seed crystal module with 50 mm in diameter. An SiC single crystal with 50 mm in diameter was successfully grown without falling out during top seeded solution growth of SiC at high temperature.

• Phonetics and Speech Sciences
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• v.14 no.4
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• pp.1-10
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• 2022

The Korean polysemic ending '-(eu)lgeol' can has two different meanings, 'guess' and 'regret'. These are expressed by different boundary-tone types: a rising tone for guess, a falling one for regret. Therefore the sentence-final boundary-tone type is the most salient prosodic feature. However, besides tone type, the pitch difference between the final and penultimate syllables of '-(eu)lgeol' can also affect semantic discrimination. To investigate this aspect, we conducted a perception test using two sentences that were morphologically and syntactically identical. These two sentences were spoken using different boundary-tone types by a Korean native speaker. From these two sentences, the experimental stimuli were generated by artificially raising or lowering the pitch of the boundary syllable by 1Qt while fixing the pitch of the penultimate syllable and boundary-tone type. Thirty Korean native speakers participated in three levels of perceptual test, in which they were asked to mark whether the experimental sentences they listened to were perceived as guess or regret. The results revealed that regardless of boundary-tone types, the larger the pitch difference between the final and penultimate syllable in the positive direction, the more likely it is perceived as guess, and the smaller the pitch difference in the negative direction, the more likely it is perceived as regret.

• The Journal of Korean Institute of Next Generation Computing
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• v.13 no.6
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• pp.124-131
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• 2017

Recently, drone is extending its range of usability. For example, the delivery, agriculture, industry, and entertainment area take advantage of drone mobilities. To control real drones, it needs huge amount of drone control training steps. However, it is risky; falling down, missing, destroying. The virtual drone system can avoid such risks. We reason that what kinds of technologies are required for building the virtual drone system. First, it needs that the virtual drone authoring tool that can assemble drones with the physical restriction in the virtual environment. We suggest that the drone assembly method that can fulfill physical restrictions in the virtual environment. Next, we introduce the virtual drone simulator that can simulate the assembled drone moves physically right in the virtual environment. The simulator produces a high quality rendering results more than 60 frames per second. In addition, we develop the physics engine based on SILS(Software in the loop simulation) framework to perform more realistic drone movement. Last, we suggest the virtual drone controller that can interact with real drone controllers which are commonly used to control real drones. Our virtual drone system earns 7.64/10.0 user satisfaction points on human test: the test is done by one hundred persons.

• 한국노년학
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• v.32 no.2
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• pp.577-592
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• 2012

The purpose of this study is to examine which factors determine fall experience among Korean elderly. To achieve this purpose, it uses the Korean Longitudinal Study of Aging(KLoSA), wave 1 and 2. Participants aged 65 from wave 1 were selected. From wave 2, a dependent variable was selected and it was fall experiences since the first interview in 2006. Other than this variable, all independent variables were selected from wave 1. In analyses, x2 or t-test were conducted to examine whether independent variables significantly differ between falls and no falls. Then, since a dependent variable consisted of two categories-falls or no falls, multiple logistic regressions were run. Female, using hearing aid, having two diseases, having three or more diseases, depression, and exercise 5 times/a week or more elevated the odds ratios of fall experience. compared to their reference categories. Particularly, if Korean elderly had three or more diseases or depression, their likelihood of fall experience would have about 2 times higher than their reference categories. In conclusion, health practitioners should make the elderly be recognized how much these risk factors are important to falls. Also, Korean government should support Korean elderly having these risk factors to prevent them from falling.

• The Journal of the Convergence on Culture Technology
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• v.10 no.3
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• pp.533-539
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• 2024

This study investigated the effects of two exercise programs, which include exercise methods to increase muscle strength, balance, and endurance, on the balance ability and fall efficacy of elderly people, and the differences in effects according to preference. Twenty-one elderly people were divided into a group using assistive devices using elastic bands (Experimental Group 1) and a group using the body (Experimental Group 2) and an exercise program was conducted for 4 weeks. The single leg stand (SLS) and functional reach test (FRT) were used to evaluate the elderly's balance ability, and the fall efficacy scale (FES) was used to evaluate the degree of fear of falling. A pre-evaluation was conducted after a 2-week integrated exercise program, and a post-evaluation was conducted after applying the exercise program for 4 weeks. In the study results, within-group SLS, FRT, and FES analyzes all showed statistically significant improvement in the post-assessment compared to the pre-assessment. However, there were no significant differences in the comparison between groups regarding exercise program and between groups according to preference. In conclusion, in order to increase the balance ability and fall efficacy of the elderly, an exercise program must be applied, and it is necessary to use a program that is easy to apply and includes exercise methods that the elderly can easily perform.