• KIPS Transactions on Computer and Communication Systems
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• v.2 no.9
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• pp.381-392
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• 2013

During the last decade, the multitude of advances attained in terminal computers, along with the introduction of mobile hand-held devices, and the deployment of high speed networks have led to a recent surge of interest in Quality of Service (QoS) for video applications. The main difficulty is that mobile devices experience disparate channel conditions, which results in different rates and patterns of packet loss. One way of making more efficient use of network resources in video services over wireless channels with heterogeneous characteristics to heterogeneous types of mobile device is to use a scalable video coding (SVC). An SVC divides a video stream into a base layer and a single or multiple enhancement layers. We have to ensure that the base layer of the video stream is successfully received and decoded by the subscribers, because it provides the basis for the subsequent decoding of the enhancement layer(s). At the same time, a system should be designed so that the enhancement layer(s) can be successfully decoded by as many users as possible, so that the average QoS is as high as possible. To accommodate these characteristics, we propose an efficient transmission scheme which incorporates SVC-aware dual-channel repetition to improve the perceived quality of services. We repeat the base-layer data over two channels, with different characteristics, to exploit transmission diversity. On the other hand, those channels are utilized to increase the data rate of enhancement layer data. This arrangement reduces service disruption under poor channel conditions by protecting the data that is more important to video decoding. Simulations show that our scheme safeguards the important packets and improves perceived video quality at a mobile device.

• Archives of Plastic Surgery
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• v.47 no.5
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• pp.460-466
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• 2020

Background Sternoclavicular joint (SCJ) osteomyelitis is a rare pathology requiring urgent intervention. Several operative approaches have been described with conflicting reports. Here, we present a multi-institutional study utilizing multiple surgical pathways for SCJ reconstruction. Methods A multi-institutional retrospective cohort study was conducted to identify patients who underwent surgical repair for sternoclavicular osteomyelitis between 2008 and 2019. Patients were stratified according to reconstruction approach: single-stage reconstruction with advancement flap and delayed-reconstruction with flap following initial debridement. Demographics, operative approach, type of reconstruction, and postoperative outcomes were analyzed. Results Thirty-two patients were identified. Mean patient age was 56.2±13.8 years and 68.8% were male. The average body mass index (BMI) was 30.0±8.8 kg/㎡. The most common infection etiologies were intravenous drug use and bacteremia (both 25%). Fourteen patients (43.8%) underwent one-stage reconstruction and 18 (56.2%) underwent delayed two-staged reconstruction. Both single and delayed-stage groups had comparable rates of reinfection (7.1% vs. 11.1%, respectively), surgical site complications (21.4% vs. 27.8%), readmissions (7.1% vs. 16.6%), and reoperations (7.1% vs. 5.6%; all P>0.05). The single-stage reconstruction group had a significantly lower BMI (26.2±5.7 kg/㎡ vs. 32.9±9.1 kg/㎡; P<0.05) and trended towards shorter hospital length of stay (11.3 days vs. 17.9 days; P=0.01). Conclusions Both single and delayed-stage approaches are appropriate methods with comparable outcomes for reconstruction for SCJ osteomyelitis. When clinically indicated, a single-stage reconstruction approach may be preferable in order to avoid a second operation as associated with the delayed phase, and possibly shortening total hospital length of stay.

• Korean Journal of Soil Science and Fertilizer
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• v.23 no.3
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• pp.173-179
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• 1990

The effect of a highly water absorbing polyacrylate polymer, commonly called K-sorb, at rates of 0.0, 0.05, 0.2, and 0.5% by weight on the water retention properties of three soils, and the longevities of these treatment effects were evaluated. Water retentions were measured for all the treatments by use of a pressure-plate extractor in the laboratory. Available water and three-phase distributions at moisture tensions of 0.01, 0.3, and 15b were calculated from water retentivity data. A randomized block experiment of Chinese cabbages was conducted to examine the effects and the longevities of the treatments(0.0, 0.05, 0.1, and 0.2%) on water retention of Jungdong sandy loam soil in the field. Water retentions for a loamy sand, sandy loam, and loam soil, treated with 0.2 and 0.5% K-sorb, were increased. K-sorb treatments were more effective in sandy soil than in loamy soils. Water contents for the 0.5% treatment were markedly greater than those for the 0.2% treatment at earth moisture tension. K-sorb only at a rate of 0.5% remained effective in water retention of each soil through repeated drying and wetting for 12 months. Duncan's multiple range showed 0.2% treatment was effective(at the level of 0.05) after 2 months but not after 10 months under field condition.

• The Journal of Engineering Geology
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• v.4 no.3
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• pp.297-309
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• 1994

For a total of 210 city and Kun areas in Korea, a model was developed to predict the amount of groundwater use at each area. At first, the total areas were classified into 3 groups by the characteristics of groundwater use: residential(87), industrial(27) and agricultural (96) areas. Among them, type areas, represented by the dominant groundwater usage for typical purposes, were selected: residential(22), industrial(8) and agricultural(32) areas. Data for the various factors possibly related to the groundwater use were statistically analyzed. The factors include, 1) agricultural area, 2) industrial area, 3) adininistrative unit area(city or Kun), 4) population, 5) groundwater capadty for community water supply, 6) average water supply for a person per day, 7) agricultural water-use, 8) industrial water-use, 9) residential wateruse, 10) rates of community water supply. The data were correlated to the total amount of groundwater use, and the correlations tested at the 95% and 99% significance levels. Influential, significantly related, factors were identified from the tests. Using the multiple regression method with the influential factors, predictive equations were drawn to calculate the amount of groundwater use for residential-industrial and agricultural areas, respectively. The equations were calibrated to minimize the RMS(root mean square) of the differences between predicted and observed groundwater use. After the validation with future data, the model can be utilized in the regional development plans to predict the maximum groundwater demand at each area.

• Journal of the Korean Institute of Gas
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• v.22 no.4
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• pp.39-48
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• 2018

This study presents optimal design of gas lift considering composition of reservoir oil and injected gas which can affect gas lift performance in offshore oil reservoir. Reservoir simulation was conducted by using reservoir models which were built in accordance with API gravity of oil. The results of simulation reveal that oil production rate is considerably increased by gas lift when the reservoir productivity decrease. As a results of response curve analysis for gas lift using well models, gas injection rate to improve the production rate increases as the API gravity of oil decreases and the specific gravity of injected gas increases. The optimal design of gas lift was carried out using multiple lift valves. Consequently, gas lift can be operated at relatively low injection pressure because of decrease in injection depth in comparison to the single lift valve design. The improved oil production rates were analyzed by coupling between reservoir model and well model. As a results of the coupling, it is expected that natural gas injection in the heavy oil reservoir is the most efficient method for improving oil production by gas lift.

• Clinical and Experimental Pediatrics
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• v.53 no.6
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• pp.694-700
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• 2010

Purpose: To assess the validity of individual and combined prognostic effects of severe bronchopulmonary dysplasia (BPD), brain injury, retinopathy of prematurity (ROP), and parenteral nutrition associated cholestasis(PNAC). Methods: We retrospectively analyzed the medical records of 80 extremely low birthweight (ELBW) infants admitted to the neonatal intensive care unit (NICU) of the Severance Children's Hospital, and who survived to a postmenstrual age of 36 weeks. We analyzed the relationship between 4 neonatal morbidities (severe BPD, severe brain injury, severe ROP, and severe PNAC) and poor outcome. Poor outcome indicated death after a postmenstrual age of 36 weeks or survival with neurosensory impairment (cerebral palsy, delayed development, hearing loss, or blindness) between 18 and 24 months of corrected age. Results: Each neonatal morbidity correlated with poor outcome on univariate analysis. Multiple logistic regression analysis revealed that the odds ratios (OR) were 4.9 (95% confidence interval [CI], 1.0-22.6; $P$=0.044) for severe BPD, 13.2 (3.0-57.3; $P$<.001) for severe brain injury, 5.3 (1.6-18.1; $P$=0.007) for severe ROP, and 3.4 (0.5-22.7; $P$=0.215) for severe PNAC. Severe BPD, brain injury, and ROP were significantly correlated with poor outcome, but not severe PNAC. By increasing the morbidity count, the rate of poor outcome was significantly increased (OR 5.2; 95% CI, 2.2-11.9; $P$<.001). In infants free of the above-mentioned morbidities, the rate of poor outcome was 9%, while the corresponding rates in infants with 1, 2, and more than 3 neonatal morbidities were 46%, 69%, and 100%, respectively. Conclusion: In ELBW infants 3 common neonatal mornidifies, severe BPD, brain injury and ROP, strongly predicts the risk of poor outcome.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.6
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• pp.2431-2440
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• 2015

Background: Registry data from four major public hospitals indicate trends in clinical care and survival from colorectal cancer over three decades, from 1980 to 2010. Materials and Methods: Kaplan-Meier productlimit estimates and Cox proportional hazards models were used to investigate disease-specific survival and multiple logistic regression analyses to explore first-round treatment trends. Results: Five-year survivals increased from 48% for 1980-1986 to 63% for 2005-2010 diagnoses. Survival increases applied to each ACPS stage (Australian Clinico-Pathological Stage), and particularly stage C (an increase from 38% to 68%). Risk of death from colorectal cancer halved (hazards ratio: 0.50 (0.45, 0.56)) over the study period after adjusting for age, sex, stage, differentiation, primary sub-site, health administrative region, and measures of socioeconomic status and geographic remoteness. Decreases in stage were not observed. Survivals did not vary by sex or place of residence, suggesting reasonable equity in service access and outcomes. Of staged cases, 91% were treated surgically with lower surgical rates for older ages and more advanced stage. Proportions of surgical cases having adjuvant therapy during primary courses of treatment increased for all stages and were highest for stage C (an increase from 5% in 1980-1986 to 63% for 2005-2010). Radiotherapy was more common for rectal than colonic cases. Proportions of rectal cases receiving radiotherapy increased, particularly for stage C where the increase was from 8% in 1980-1986 to 60% in 2005-2010. The percentage of stage C colorectal cases less than 70 years of age having systemic therapy as part of their first treatment round increased from 3% in 1980-1986 to 81% by 1995-2010. Based on survey data on uptake of adjuvant therapy among those offered this care, it is likely that all these younger patients were offered systemic treatment. Conclusions: We conclude that pronounced increases in survivals from colorectal cancer have occurred at major public hospitals in South Australia due to increases in stage-specific survivals. Use of adjuvant therapies has increased and the patterns of change accord with clinical guideline recommendations. Reasons for sub-optimal use of radiotherapy for rectal cases warrant further investigation, including the potential for limited rural access to impede uptake of treatments at metropolitan-based radiotherapy centres.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.7
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• pp.86-91
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• 2016

To solve the problem of the excessive error caused by using a single value for the shielding effect of the neutral line of an electric power distribution line in the calculation of the voltage it induces in a telecommunication line, the general expression that was previously developed to reflect the mechanism of voltage induction by a distribution line with multiple grounds is employed in this paper to represent the relationship between the leakage current rates at each ground pole. In this way, the formula for calculating the shielding effect of the neutral line can be factorized against the unbalanced current flowing in the neutral line, which is the root current of induction. This shielding coefficient of the neutral line is not constant, but can vary when a range of induced voltages is generated in the whole power distribution line. The calculation method developed herein reduces the error rate to one tenth of that of the existing calculation result in the case of overestimation and increases it by 14% in the case of underestimation.

• Journal of the Korean Society for information Management
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• v.37 no.2
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• pp.197-223
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• 2020

The purpose of this study is to analyze the issues resulted from the process of grouping KORMARC records using FRBR WORK concept and to suggest a new method. The previous studies did not sufficiently address the criteria or processes for identifying representative authors of records and their derivatives. Therefore, our study focused on devising a method of identifying the representative author when there are multiple contributors in a work. The study developed a method of identifying representative authors using an author role dictionary constructed by extracting role-terms from the statement of responsibility field (245). We also designed another way to group records as a work by calculating similarity measures of authors and titles. The accuracy rate of WORK grouping was the highest when blank spaces, parentheses, and controling processes were removed from titles and the measured similarity rates of authors and titles were higher than 80 percent. This was an experiment study where we developed an author-role dictionary that can be utilized in selecting a representative author and measured the similarity rate of authors and titles in order to achieve effective WORK grouping of KORMARC records. The future study will attempt to devise a way to improve the similarity measure of titles, incorporate FRBR Group 1 entities such as expression, manifestation and item data into the algorithm, and a method of improving the algorithm by utilizing other forms of MARC data that are widely used in Korea.

• The Journal of the Korea Contents Association
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• v.18 no.5
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• pp.230-240
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• 2018

The objective of this study is to observe the exclusive breastfeeding(EBF) rate and to identify factors which influence EBF by postpartum period. The data were obtained from the 2015 National Fertility Survey, Family Health and Welfare in Korea, and secondary data analysis were employed for 1,839 mothers who gave birth to baby between January 2013 and February 2015. Data were analyzed using SPSS 25.0 program with descriptive statistics, chi-square test and multiple logistic regression. The EBF rate at the 1st and 6th month of postpartum were 54.0%, 9.4% respectively. The significant influencing factors on the EBF at the 1st month of postpartum were age of mother, baby's birth rank, type of delivery, breastfeeding within 1 hour after delivery. The significant influencing factors on the EBF at the 6th month of postpartum were age of mother, living area, EBF in the first month. We found that the influencing factors on EBF differed by postpartum period. In order to improving the rate of EBF, it is recommended that taioed interventions is needed considering the factors affecting the EBF by postpartum period.