• Journal of the Korean Geotechnical Society
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• v.21 no.8
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• pp.107-116
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• 2005

Generally, when the stability of the geosynthetic reinforced soil slopes is analyzed, the required tensile forces of each reinforcement layers are calculated from total reinforcement forces which are necessary to retain the equilibrium state of slip mass in which the slip surfaces are assumed to be a linear or bilinear. It is assumed that the reinforcement forces are increased or constant with depth. However, according to the instrumented field data and laboratory model test results, the maximum tensile strain of reinforcement in a reinforced soil slope is developed in a certain elevation, not a bottom of the slope. In the concept of reinforced soil, postulated failure surfaces are the traces of the position in which the reinforcement tensile forces are maximum in the layer, and the reinforcement tensile forces are related to the stress state on the postulated failure surface. Therefore, in this study, based on the distribution of normal stress on the slip surface, a new method for the evaluation of required tensile forces is suggested and a number of the instrumented field data are analyzed by newly suggested method. As a result, it is shown that the newly suggested method produces relatively accurate reinforcement tension forces.

• Journal of the Korean Geotechnical Society
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• v.21 no.8
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• pp.63-72
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• 2005

Rocks are dumped to soft marine ground in order to improve trafficability and construction conditions in the tideland reclamation construction sites. Though this rock layer under earth fill has caused in a serious seepage problems after construction, seepage behaviors of this embankment structure is not correctly investigated. Water flow through rock layers is, in general, known as Non-Darcy's flow. However, the embedded rock layer under earth fill is not known whether its flow is governed by Darcy's or Non-Darcy's law. Therefore, a numerical analysis, laboratory model test and filed investigations were performed for analyzing the those seepage characteristics in this research. Results show that there is significance of $95\%$ of confidence between observed heads and seepage rates, and the calculated ones by SAMTLE which is developed under the assumption that the water flows through the two-layer system obey the Darcy's flow. And after operating the hydraulic gradient(i) of $0.10\~0.55$ upon laboratory model, these seepage characteristics of the embedded rock layer show that Reynolds Numbers are less than 10 and the relationship between these velocities of rock layer(v) and hydraulic gradients(i) is linearly proportional with more than 0.79 of the coefficient of correlation $(R^2)$. And the Reynolds Number of the velocity calculated by the relation of v=ki in the embedded rock layer of OO sea dike is $1\~6$. It shows also laminar flow. Based on these results, it is concluded that the seepage characteristics of embedded rock layer under earth fill can be laminar and Darcy's flow.

• Journal of Korean Academic Society of Home Health Care Nursing
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• v.8 no.1
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• pp.50-61
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• 2001

With the improvement of current medicine, the number of the chronicly ill children are increasing. The illness of the child drives all of the family to despair. especially it is a burden on the mother who takes care of the ill child. She's faced with many emergencies and feels powerless. The home care for a child is for finding a child's problems early and mediating them. The purpose of this study was to investigate the mother's reaction following their chronicly ill child's discharge and to investigate the supporting needs for caring for an ill child. The subjects of this study were mothers with a chronicly ill child being discharged from a general hospital in Seoul and the data was collected from July 20 to September 30. Data was collected by using questionnaires which were developed by the researcher. (The questionnaires were composed of the average 5 points - Likert's method). The Mother's reaction means that the higher the score, the more negative the mother's thoughts about discharge are. Supporting need for caring for ill an child means that the higher the score, the higher the demand of nursing is. The statistical analysis used the SPSS program for t-test. ANOVA, and Pearson Correlation. The results of this study were as follows: 1. The mother's reaction scores following discharge were the lowest. 19 and the highest 72 so that the total average was 43.15. The answer, 'I worry that my baby will be troubled with illness again after discharge gained the high points (3.94 of 5 points). The answer. 'The discharge of my baby makes me gloomy' gained 2.05-it was the lowest points. Their were significant differences according to religion (p=.006). salary (p=.050). the burden of the medical fee (p = .005) and caregiver (p=.027). 2. Supporting Need for caring for ill an child was the lowest 15 and the highest 67. the total average was 47.87. The answer. 'I'd be glad to get a person whom I could always get counsel about the health of my baby with' scored the high point (average 4.04 of 5). The answer. 'Caring for my baby at home makes me exhausted' gained the lowest point. 2.49. Their were significant differences according to religion (p=.019) and diagnosis (p=.019). 3. The relationship between the reaction of the mother and supporting need for caring for an ill child was a positive correlation (r=0.585). In conclusion. this study revealed that mothers weren't positive about their chronicly ill child's discharge and they wanted to get support for caring for an ill child. Through this study. I proposed that the program to support the chronicly ill child at home and home care by continuous counselling after discharge should be develop.

• Journal of the Korean Geotechnical Society
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• v.30 no.11
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• pp.51-60
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• 2014

Load and Resistance Factor Design (LRFD) is one of the limit state design methods, and has been used worldwide, especially in North America. Also, the study for LRFD has been actively conducted in Korea. However, the data for LRFD in Korea were not sufficient, so resistance factors suggested by AASTTO have been used for the design in Korea. But the resistance factors suggested by AASHTO represent the characteristics of bedrocks defined in the US, therefore, it is necessary to determine the resistance factors for designs in Korea, which can reflect the characteristics of bedrocks in Korea. Also, the calculated probabilities of failure from conventional reliability analyses which commonly use log-normal distribution are not realistic because of the lower tail that can be extended to zero. Therefore, it is necessary to calibrate the resistance factors considering the lower-bound resistance. Thus, this study calculates the resistance factors using thirteen sets of drilled shaft load test results, and then calibrates the resistance factors considering the lower-bound resistance corresponding to a target reliability index of 3.0. As a result, resistance factors from conventional reliability analyses were determined in the range of 0.13-0.32 for the shaft resistance, and 0.19-0.29 for the base resistance, respectively. Also, the lower bounds of resistance were determined based on the Hoek-Brown failure criteria (2002) and GSI downgrading. Considering the lower-bound resistances, resistance factors increased by 0~8% for the shaft, and 0~13% for the base, respectively.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.10
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• pp.1976-1985
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• 2015

The amount of packets in palyout buffer of video streaming receiver can be changed by network condition, and saturated and exhausted by the delay and jitter. Especially, if the amount of incoming video traffic exceeds the maximum allowed playout buffer, buffer overflow problem can be generated. It makes the deterioration of video image and the discontinuity of playout by skip phenomenon. Also, if the incoming packets are delayed by network confusion, the stop phenomenon of video image is made by buffering due to buffer underflow problem. To solve these problems, this paper proposes the video streaming receiver with token bucket scheme which automatically establishes the important parameters like token generation rate r and bucket maximum capacity c adapting to the pattern of video packets. The simulation results using network simulator-2 (NS-2) and joint scalable video model (JSVM) show that the proposed token bucket scheme with automatic establishment parameter provides better performance than the existing token bucket scheme with manual establishment parameter in terms of the generation number of overflow and underflow, packer loss rate, and peak signal to noise ratio (PSNR) in three test video sequences.

• Journal of Haehwa Medicine
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• v.8 no.1
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• pp.865-878
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• 1999

With advances in neonatal medicine, smaller and sicker infants are surviving premature birth. As these tiny patients battle for their lives, their parents also struggle with psychological consequences of an unexpected role. The birth of a sick infants has long been documented as stressful events for the parents. High stress levels may alter parents' interaction with their baby and impair their communication with health professionals, which can in turn affect parents' participation in care planning and decision making. Nursing interventions aimed at reducing the parental stress and anxiety levels during this crisis may have a positive impact on their ability to form an attatchment to their baby and make prudent decisions about his care. The planning of such interventions would be inhanced if the contributions of various factors to increased parental stress levels were identified. This descriptive study was conducted to understand the contents and degree of parental stress in the NICU during their premature's hospitalization, and to give a baseline data in developing nursing intervention program. Subjects were the 60 mother of hospitalized newborn in NICU of 2 University Hospital in Taejon City from April 1st, 1999 to June 30th, 1999, who agreed to take part in this study. The instrument used in this study were Parental Stressor Scales:NICU(PSS:NICU) developed by Miles et al.. and validated by 3 NICU practitioners and 3 child health nursing faculties. The questionnaire has 4 dimensions and 45 items; sight and sounds of NICU(5 items), babies' appearance and behavior nursing intervention(19 items), parental role alteration and relationship with their baby(10 items), health team communication(11 items). The questionnaire asks parents to rate each item on a five-point Likert type scale that ranges from "not stressful" (1) to "extremely stressfu1"(5). Total scores representing overall stress from the NICU environment are calculated by summing response to each item. A high score indicates high stress. A subscale score is calculated by summing the responses to each item in the subscale. Cronbach's ${\alpha}$ coefficients were .93. The data was analyzed as average, Frequency, Standard deviation, t-test, ANOVA, Pearson correlation coefficient by use of SPSS/PC+. The results of this study is summarized as follows ; 1. The total perceived stress level score of mothers of premature baby was slightly high($3.66{\pm}1.1$). The highest scored dimension was 'relationship with their baby and parental role change'($4.21{\pm}0.9$), and next were 'appearance and behavior of the baby'($3.92{\pm}1.1$), 'communication with health team'($3.32{\pm}1.3$), 'sight and sounds of NICU'($3.30{\pm}1.1$). 2. There were statistically significant correlation noted ; mother's perceived severity of the baby's condition(F=8.0012, P= .0125) and baby's gestational age(r = -.4724, P = .0500). In summary, information about physical environment of NICU, the mother's perceived severity of premature baby's state, maternal role change related variables and the knowledge of characteristics of premature baby must be included in nursing intervention program of mother's of premature baby in reducing the parental stress and anxiety level. It is suggested that each NICU needs to develop a nurse managed supportive care program for parents of premature baby. Also, it is suggested that there need to investigate the coping mechanism of mother of premature baby.

• Ocean Systems Engineering
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• v.6 no.1
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• pp.23-60
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• 2016

The major objective of this study was to develop further understanding of 3D nearshore hydrodynamics under a variety of wave and tidal forcing conditions. The main tool used was a comprehensive 3D numerical model - combining the flow module of Delft3D with the WAVE solver of XBeach - of nearshore hydro- and morphodynamics that can simulate flow, sediment transport, and morphological evolution. Surf-swash zone hydrodynamics were modeled using the 3D Navier-Stokes equations, combined with various turbulence models (${\kappa}-{\varepsilon}$, ${\kappa}-L$, ATM and H-LES). Sediment transport and resulting foreshore profile changes were approximated using different sediment transport relations that consider both bed- and suspended-load transport of non-cohesive sediments. The numerical set-up was tested against field data, with good agreement found. Different numerical experiments under a range of bed characteristics and incident wave and tidal conditions were run to test the model's capability to reproduce 3D flow, wave propagation, sediment transport and morphodynamics in the nearshore at the field scale. The results were interpreted according to existing understanding of surf and swash zone processes. Our numerical experiments confirm that the angle between the crest line of the approaching wave and the shoreline defines the direction and strength of the longshore current, while the longshore current velocity varies across the nearshore zone. The model simulates the undertow, hydraulic cell and rip-current patterns generated by radiation stresses and longshore variability in wave heights. Numerical results show that a non-uniform seabed is crucial for generation of rip currents in the nearshore (when bed slope is uniform, rips are not generated). Increasing the wave height increases the peaks of eddy viscosity and TKE (turbulent kinetic energy), while increasing the tidal amplitude reduces these peaks. Wave and tide interaction has most striking effects on the foreshore profile with the formation of the intertidal bar. High values of eddy viscosity, TKE and wave set-up are spread offshore for coarser grain sizes. Beach profile steepness modifies the nearshore circulation pattern, significantly enhancing the vertical component of the flow. The local recirculation within the longshore current in the inshore region causes a transient offshore shift and strengthening of the longshore current. Overall, the analysis shows that, with reasonable hypotheses, it is possible to simulate the nearshore hydrodynamics subjected to oceanic forcing, consistent with existing understanding of this area. Part II of this work presents 3D nearshore morphodynamics induced by the tides and waves.

• Journal of the Korea Society of Computer and Information
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• v.18 no.10
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• pp.109-119
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• 2013

An unmanned ground vehicle(UGV) today plays a significant role in both civilian and military areas. Predominantly these systems are used to replace humans in hazardous situations. To take unmanned ground vehicles systems to the next level and increase their capabilities and the range of missions they are able to perform in the combat field, new technologies are needed in the area of command and control. For this reason, we present war field simulator based on information fusion technology to efficiently control UGV. In this paper, we present the war field simulator which is made of critical components, that is, simulation controller, virtual image viewer, and remote control device to efficiently control UGV in the future combat fields. In our information fusion technology, improved methods of target detection, recognition, and location are proposed. In addition, time reduction method of target detection is also proposed. In the consequence of the operation test, we expect that our war field simulator based on information fusion technology plays an important role in the future military operation significantly.

• Korean journal of applied entomology
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• v.26 no.2 s.71
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• pp.99-106
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• 1987

Three post-harvest fields each in four rice growing areas, Iri, Naju, Jinju and Taegu were randomly selected and surveyed during December 1986 to examine sclerotial density of Rhizoctonia solani overwintering in the field. Surface soil of $0.09m^2$ area was sampled in each field with three replications and sieved to collect sclerotia. Germiability and pathogenicity of collected sclerotia were examined in the laboratory. Number of sclerotia $({\times}10^6)/ha$ in Iri, Naju, Jinju, and Taegu was estimated from the sample as 2.7, 1.2, 0.7 and 0.6, respectively. Based on sample variance with simple random sampling in each area, number of sampling required for estimating average sclerotial density with the precision of 10% apart from a chance of 1 in 20 was calculated to 41, 132, 232, and 395 for Iri, Naju, Jinju and Taegu, respectively. Percentage of germination of sampled sclerotia on potato sucrose agar (PSA) ranged from 42 to 78% depending on the area, and averaged 60%. About 49% of the germinated sclerotia were pathogenic to a rice cultivar Jinheung that was used to test pathogenicity of the sclerotia. Proportion of viable sclerotia that have both germiability and pathogenicity was thus estimated to 0.29 of total sclerotia collected. R. solani cultures obtained from the sclerotia could be distinguished into three groups based on colony morphology on PSA. Size and number of sclerotia formed on PSA differed between group but were not associated with pathogenicity to Jinheung.

• Journal of Digital Convergence
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• v.17 no.12
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• pp.435-444
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• 2019

The purpose of this study was to investigate the relationship between sleep duration and muscle strength in Korean adults aged 19 years and older. The cross-sectional analysis was conducted using the 2016 National Health and Nutrition Examination Survey data and Chi square test and multiple regression analysis were used. As a result of the analysis, the grip strength of those with more than weekday average sleep duration of 9 hours was found to be -1.267kg compared with those with weekday average sleep duration of 7 hours. The grip strength of those with more than weekend average sleep duration of 9 hours was found to be -0.879kg compared with those with weekend average sleep duration of 7 hours. In model simultaneously adjusting for both the average weekday and weekend average sleep duration, weekday average sleep duration of 9 hours was found to be -1.034kg compared with those with weekday average sleep duration of 7 hours. Therefore, careful observation will be required in light of the fact that both sleep duration and grip strength can predict future health conditions.