• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.5
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• pp.942-947
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• 2008

A cluster server usually consists of a front end node and multiple backend nodes. Though increasing the number of bookend nodes can result in the more QoS(Quality of Service) streams for clients, the possibility of failures in backend nodes is proportionally increased. The failure causes not only the stop of all streaming service but also the loss of the current playing positions. In this paper, when a backend node becomes a failed state, the recovery mechanisms are studied to support the unceasing streaming service. The basic techniques are hewn as providing very high speed data transfer rates suitable for the video streaming. However, without considering the architecture of cluster-based VOD server, the application of these basic techniques causes the performance bottleneck of the internal network for recovery and also results in the inefficiency CPU usage of backend nodes. To resolve these problems, we propose a new failure recovery mechanism based on the pipeline computing concept.

• Journal of Korean Medical Science
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• v.33 no.48
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• pp.312.1-312.10
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• 2018

Background: Obesity is related to several comorbidities and mortality, but its relationship with acute kidney injury (AKI) and long-term mortality remain undetermined in patients undergoing coronary artery bypass grafting. Methods: Data from 3,018 patients (age ${\geq}18$ years) who underwent coronary artery bypass graft surgery from two tertiary referral centers were retrospectively reviewed between 2004 and 2015. Obesity was defined using the body mass index, according to the World Health Organization's recommendation. The odds and hazard ratios in post-surgical, AKI, and all-cause mortality were calculated after adjustment for multiple covariates. Patients were followed for $90{\pm}40.9$ months (maximum: 13 years). Results: Among the cohort, 37.4%, 2.4%, 21.1%, 35.1%, and 4.0% of patients were classified as normal weight, underweight, overweight-at-risk, obese I, and obese II, respectively. Post-surgical AKI developed in 799 patients (26.5%). Patients in the obese groups (overweight-at-risk to obese II) had a higher risk of AKI than did those in the normal-weight group. During the follow-up period, 787 patients (26.1%) died. Underweight patients had a higher risk of mortality than did normal-weight patients, whereas overweight-at-risk, obese I, and obese II patients showed better survival rates. Conclusion: After coronary artery bypass graft surgery, obese patients encountered a high risk of AKI, and underweight patients exhibited a low chance of survival. Awareness of both obese and underweight statuses should be raised in these patients.

• KIPS Transactions on Software and Data Engineering
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• v.8 no.11
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• pp.427-432
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• 2019

In this paper, we propose three approaches to modeling Android malware. The first method involves human security experts for meticulously selecting feature sets. With the second approach, we choose 300 features with the highest importance among the top 99% features in terms of occurrence rate. The third approach is to combine multiple models and identify malware through weighted voting. In addition, we applied a novel method of eliminating permission information which used to be regarded as a critical factor for distinguishing malware. With our carefully generated feature sets and the weighted voting by the ensemble algorithm, we were able to reach the highest malware detection accuracy of 97.8%. We also verified that discarding the permission information lead to the improvement in terms of false positive and false negative rates.

• Journal of Soil and Groundwater Environment
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• v.25 no.2_spc
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• pp.1-15
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• 2020

Monitoring and assessing terminal electron accepting processes (TEAPs) are one of the most important steps to remediate contaminated sites via various in-situ techniques. TEAPs are a part of the microbial respiration reactions. Microorganisms gain energy from these reactions and reduces pollutants. Monitoring TEAPs enables us to predict degradability of contaminants and degradation rates. In many countries, TEAPs have been used for characterization of field sites and management of groundwater wells. For instance, US Environmental Protection Agency (EPA) provided strategies for groundwater quality and well management by applying TEAPs monitoring. Denmark has also constructed TEAPs map of local unit area to develop effective groundwater managing system, particularly to predict and assess nitrogen contamination. In case of Korea, although detailed soil survey and groundwater contamination assessment have been employed, site investigation guidelines using TEAPs have not been established yet. To better define TEAPs in subsurface environments, multiple indicators including ion concentrations, isotope compositions and contaminant degradation byproducts must be assessed. Furthermore, dissolved hydrogen concentrations are regarded as significant evidence of TEAPs occurring in subsurface environment. This review study introduces optimal sampling techniques of groundwater and dissolved hydrogen, and further discuss how to assess TEAPs in contaminated subsurface environments according to several contamination scenarios.

• International Neurourology Journal
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• v.22 no.4
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• pp.305-312
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• 2018

Purpose: The aim of this study was to analyze the efficacy and to estimate the complication rate of incontinence surgery according to the surgeon's specialty and whether a preoperative urodynamic study (UDS) was performed, using a nationally representative dataset. Methods: We enrolled 356,155 women over 20 years old who had undergone surgery for stress urinary incontinence between 2006 and 2015. Patients were followed for up to 3 years to analyze the reoperation and complication rates. Data were obtained from the National Health Claims Database of the National Health Insurance Service (NHIS) of Korea. Multiple Cox regression analysis was conducted to examine the efficacy and safety of incontinence surgery according to the surgeon's specialty and whether a preoperative UDS was performed. Results: The hazard ratio (HR) for reoperation was significantly higher for procedures performed by nonurologists than for procedures performed by urologists (HR, 1.174; 95% confidence interval [CI], 1.103-1.249). Acute urinary retention, postoperative infections, procedure-associated pain, and other complications were also more common in procedures performed by nonurologists than in those performed by urologists. When stratified by whether a preoperative UDS was performed, the HR for reoperation according to the surgeon's specialty varied by performance of a preoperative UDS. While the reoperation rate was significantly higher in procedures performed by non-urologists when a preoperative UDS was performed (HR, 1.208; 95% CI, 1.122-1.3), there was no significant difference in the HRs for reoperation according to specialty when a preoperative UDS was not performed. Conclusions: This population-based study showed that the postoperative outcomes of incontinence surgery were dependent upon the surgeon's specialty and that the reoperation rate according to the surgeon's specialty varied based on whether a preoperative UDS was performed.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.42 no.1
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• pp.137-142
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• 2019

There are two methods for evaluating two or more mutually exclusive projects. One is a total investment approach and the other is an incremental investment approach. The former can rank projects by the criterion of the net present value, but the latter can't do it. An incremental investment approach is only possible when all pairwise alternatives are compared. Thus an incremental investment approach is superior in ranking them over an incremental investment approach. To do so, a principle of comparison must be established. Comparisons of profitability are reasonable when operating the same amount of investment over the same period of time. One principle is that all projects are invested in the largest of the projects. Another principle is that all projects are invested during the longest project life of the projects. In this paper, even if the principle is followed, it will be shown that the external rate of return fails to rank them. However, the productive rate of return criterion would prove to be able to rank them like the net present value standard, provided that the principle of comparison is kept. In addition, rate of returns can be assessed so that all mutually exclusive projects can be compared at once, such as on the criterion of the net present value. That is, it can be also compared with many other returns, such as the profit rates on financial investments or real investments.

• International Journal of Advanced Culture Technology
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• v.7 no.2
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• pp.28-33
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• 2019

Electronic health records (EHRs) enable us to use and re-use electronic data for various multiple purposes, such as public reporting, quality improvement, and patient outcomes research. Current hospital-acquired pressure injury (HAPI) risk assessment instruments have not been specifically developed for intensive care unit (ICU) patients and showed false positive rates in this specific populations. Previous research studies report a number of risk factors; however, it is still not clear what factors influence ICU HAPI in this population. As part of a larger research study, we performed an exploratory analysis by using a large electronic health record data. The aims of this study were to compare characteristics of patients who developed HAPIs during their ICU stay with those who did not, and to determine whether the two groups were different in the aspects of length of ICU stay, discharge disposition, and discharge destinations. We conducted chi-square test and t-test for group comparison. Association was examined by using bivariate analyses. Pearson correlation coefficients were used to examine correlation between LOS and number of medications. Our findings suggest a number of consistent and potentially modifiable risk factors, such as sedation, feeding tubes, and the number of medications administered. The mortality of the HAPI group was significantly higher than the non-HAPI group in our data. Discharge disposition was significantly different between the groups. 67% of the HAPI group transferred to intermediate or long-term care hospitals whereas 57.7% of the non-HAPI group went home after discharge. Awareness of these risk factors can lead to clinical interventions that can be preventative in the ICU setting.

• The Journal of Korean Institute of Information Technology
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• v.16 no.11
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• pp.1-9
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• 2018

Drug repositioning is to discover new uses of drugs. Text mining derives knowledge from unstructured text. We propose a method to predict new drug-disease relationships by taking into account the rate of frequency of genes simultaneously measured in disease-gene and gene-drug. Co-occurrence of drug-gene and gene-disease in the biological literature is counted and calculate the rate of the gene for each drug and disease. Weights of drug-disease relationships are calculated using the average of the rates of genes that are measured and used to measure the accuracy for each disease. In measuring drug-disease relationships, a more accurate identification of relationships was shown by measuring the frequency on a sentence and considering multiple relationships than existing method.

• Women's Health Nursing
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• v.25 no.3
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• pp.285-298
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• 2019

Purpose: The purpose of this study was to identify the impacts of human papillomavirus (HPV) vaccination-related health belief, attitudes toward HPV vaccination, and subjective norms on HPV vaccination intent targeting mothers of elementary school daughters. Methods: The study use a correlative survey design. The subjects of the study were 121 mothers of elementary school daughters located in metropolitan city B. All subjects agreed to participate in the study. The data were collected from September 1 to October 18, 2018, and were analyzed using descriptive statistics, Independent t-test, ANOVA with a post hoc $Scheff{\acute{e}}$ test, Pearson's correlation coefficients, and stepwise multiple regression. Results: Attitude toward HPV vaccination, subjective norms, vaccination plans for their children, and mother's vaccination status were significant factors influencing HPV vaccination intention. These factors accounted for 72% of the HPV vaccination intention. Conclusions: This study showed that factors affecting the intention of mothers of elementary school daughters to vaccinate against HPV were HPV vaccination attitudes, subjective norms, vaccination plans for their children, and mother's vaccination status. The biggest influencing factor was HPV vaccination attitudes. Therefore, in order to encourage mothers of elementary school daughters to vaccinate against HPVs, national-level policies should be implemented to create a social atmosphere of positive attitudes toward HPV vaccinations that also emphasizes how easy it is to get vaccinated against HPV. Based on this, mothers of elementary school daughters should be encouraged to have them vaccinated against HPV, thus contributing to improving the HPV vaccination rates of elementary school girls.

• Advances in Computational Design
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• v.4 no.2
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• pp.119-139
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• 2019

Planning and management building projects should tackle the coordination of works and the management of limited spaces, traffic and supplies. Activities cannot be performed without the resources available and resources cannot be used beyond the capacity of workplaces. Otherwise, workspace congestion will negatively affect the flow of works. Better on-site management allows for substantial productivity improvements and cost savings. The procurement system should be able to manage a wider variety of materials and products of the required quality in order to have less stock, in less time, using less space, with less investment and avoiding multiple storage stations. The objective of this paper is to demonstrate the advantages of using the Chronographic modeling, by combining spatiotemporal technical scheduling with the 4D simulations, the Last Planner System and the Takt-time when modeling the construction of building projects. This paper work toward the aforementioned goal by examining the impact that material flow has on site occupancy. The proposed spatiotemporal model promotes efficient site use, defines optimal site-occupancy and workforce-rotation rates, minimizes intermediate stocks, and ensures a suitable procurement process. This paper study the material flow on the site and consider horizontal and vertical paths, traffic flows and appropriate means of transportation to ensure fluidity and safety. This paper contributes to the existing body of knowledge by linking execution and supply to the spatial and temporal aspects. The methodology compare the performance and procurement processes for the proposed Chronographic model with the Gantt-Precedence diagram. Two examples are presented to demonstrate the benefits of the proposed model and to validate the related concepts. This validation is designed to test the model's graphical ability to simulate construction and procurement.