• Journal of Korean Neurosurgical Society
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• v.63 no.6
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• pp.827-833
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• 2020

Objective : Spine surgery is associated with higher morbidity and mortality rates in elderly patients. The modified Frailty Index (mFI) is an evaluation tool to determine the frailty of an individual and how preoperative status may impact postoperative survival and outcomes. This study aimed to determine the usefulness of mFI in predicting postoperative complications in patients aged ≥75 years undergoing surgery with instrumentation. Methods : We retrospectively reviewed the perioperative course of 137 patients who underwent thoracolumbar-instrumentation spine surgery between 2011 and 2016. The preoperative risk factors were the 11 variables of the mFI, as well as body mass index (kg/㎠), preoperative hemoglobin, platelet, albumin, creatinine, anesthesia time, operation time, estimated blood loss, and transfusion amount. The 60-day occurrences of complication rates were used for outcome assessment. Results : Major complications after spinal instrumentation surgery occurred in 34 of 138 patients (24.6%). The mean mFI score was 0.18±0.12. When we divided patients into a pre-frail group (mFI, 0.09-0.18; n=94) and a frail group (mFI ≥0.27; n=44), only the rate of sepsis was statistically higher in the frail group than in the pre-frail group. There were significantly more major complications in patients with low albumin levels or in patients with infection or who had experienced trauma. The mFI was a more useful predictor of postoperative complications than the American Society of Anesthesiologists physical status score. Conclusion : The mFI can successfully predict postoperative morbidity and mortality in patients aged ≥75 years undergoing spine surgery. The mFI improves perioperative risk stratification that provides important information to assist in the preoperative counselling of patients and their families.

• Journal of Advanced Navigation Technology
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• v.21 no.1
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• pp.50-57
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• 2017

Recently, safety-critical aviation system development programs promoted domestically have been terminated in the middle stage or they have not been put to practical use at the final stage. The program failure may be caused by various factors, but this study focused on imperfect test and evaluation(T&E) procedures. In general, T&E process of a safety-critical system must be distributed throughout the entire life-cycle of the system, have a continuity in phases, and can be implemented in a variety of ways depending on the maturity of the system development and acquisition strategy. This paper aims to present a new strategy by analyzing the domestic and overseas T&E processes to reduce the risk of domestic safety-critical CNS/ATM system development program and increase the success rate of program. First, we discuss the verification and validation techniques for safety-critical systems, analyze the T&E procedures of advanced institutes and the domestic situation, and then compare the domestic and overseas T&E processes to complement the imperfect testing procedure.

• Korean Journal of Human Ecology
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• v.22 no.5
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• pp.477-490
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• 2013

This study explores critical and success factor of benefits and risks for predicting the acceptance of QR code virtual fashion stores. As an exploratory approach, this study conducted focus group interviews(FGI) with 21 panels who had experience with selected QR virtual stores (e.g., Home plus, 11th Street, Pin & Fit). Content analysis was used to generate 184 excerpts and classify into benefits and risks related to QR code virtual stores. With respect to benefits, content analysis identified four factors: Affective appeal, perceived usefulness, ubiquity, and brand promotion. Also, contents regarding perceived risks were classified into four factors: Complexity, lack of information, lack of technology infrastructure, and perceived cost. A managerial implication was discussed for predicting consumer technology acceptance of a QR code virtual store in the fashion retailing market.

• Journal of Information Processing Systems
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• v.9 no.1
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• pp.69-88
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• 2013

Agile methods are highly attractive for small projects, but no agile method works well as a standalone system. Therefore, some adaption or customization is always required. In this paper, the Agile Framework for Small Projects (AFSP) was applied to four industry cases. The AFSP provides a structured way for software organizations to adopt agile practices and evaluate the results. The framework includes an extended Scrum process and agile practices, which are based on agility and critical success factors in agile software projects that are selected from Scrum, XP, FDD, DSDM and Crystal Clear. AFSP also helps software managers and developers effectively use agile engineering techniques throughout the software development lifecycle. The case study projects were evaluated on the basis of risk-based agility factors, the agility of the adopted practices, agile adoption levels, and the degree of the agile project success. The analysis of the results showed that the framework used in the aforementioned cases was effective.

• International Journal of Concrete Structures and Materials
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• v.6 no.1
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• pp.31-40
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• 2012

Self-consolidating concrete (SCC) is a recently developed innovative construction material. SCC fills in a formwork without any vibrating consolidation, which allows us to eventually achieve robust casting. However, high formwork lateral pressure exerted by SCC is a critical issue regarding its application as cast-in-place concrete. In order to control the risk caused by high formwork pressure, a comprehensive prediction model for the pressure was previously proposed, investigated, and validated with various SCC mixtures. The model was originally designed to simulate the intrinsic pressure response of SCC mixtures while excluding other extrinsic influencing factors such as friction and flexibility of the formwork. The model was then extended to consider extrinsic factors such as friction between SCC mixtures and formwork. In addition, other interesting topics for peak formwork pressure and mineral admixture effects were summarized in the paper.

• Journal of Trauma and Injury
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• v.36 no.3
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• pp.196-205
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• 2023

Purpose: Surgical stabilization of rib fractures (SSRF) is widely used in patients with flail chests, and several studies have reported the efficacy of SSRF even in multiple rib fractures. However, few reports have discussed the hardware failure (HF) of implanted plates. We aimed to evaluate the clinical characteristics of patients with HF after SSRF and further investigate the related factors. Methods: We retrospectively reviewed the electronic medical records of patients who underwent SSRF for multiple rib fractures at a level I trauma center in Korea between January 2014 and January 2021. We defined HF as the unintentional loosening of screws, dislocation, or breakage of the implanted plates. The baseline characteristics, surgical outcomes, and types of HF were assessed. Results: During the study period, 728 patients underwent SSRF, of whom 80 (10.9%) were diagnosed with HF. The mean age of HF patients was 56.5±13.6 years, and 66 (82.5%) were men. There were 59 cases (73.8%) of screw loosening, 21 (26.3%) of plate breakage, 17 (21.3%) of screw migration, and seven (8.8%) of plate dislocation. Nine patients (11.3%) experienced wound infection, and 35 patients (43.8%) experienced chronic pain. A total of 21 patients (26.3%) underwent reoperation for plate removal. The patients in the reoperation group were significantly younger, had fewer fractures and plates, underwent costal fixation, and had a longer follow-up. There were no significant differences in subjective chest symptoms or lung capacity. Conclusions: HF after SSRF occurred in 10.9% of the cases, and screw loosening was the most common. Further longitudinal studies are needed to identify risk factors for SSRF failure.

• Journal of Gastric Cancer
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• v.12 no.3
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• pp.149-155
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• 2012

Purpose: Although serosal invasion is a critical predisposing factor for peritoneal dissemination in advanced gastric cancer, the accuracy of preoperative assessment using routine imaging studies is unsatisfactory. This study was conducted to identify high-risk group for serosal invasion using preoperative factors in patients with advanced gastric cancer. Materials and Methods: We retrospectively analyzed clinicopathological features of 3,529 advanced gastric cancer patients with Borrmann type I/II/III who underwent gastrectomy at Korea Cancer Center Hospital between 1991 and 2005. We stratified patients into low-(${\leq}40%$), intermediate-(40~70%), and high-risk (>70%) groups, according to the probability of serosal invasion. Results: Borrmann type, size, longitudinal and circumferential location, and histology of tumors were independent risk factors for serosal invasion. Most tumors of whole stomach location or encircling type had serosal invasion, so they belonged to high-risk group. Patients were subdivided into 12 subgroups in combination of Borrmann type, size, and histology. A subgroup with Borrmann type II, large size (${\geq}7$ cm), and undifferentiated histology and 2 subgroups with Borrmann type III, large size, and regardless of histology belonged to high-risk group and corresponded to 25% of eligible patients. Conclusions: This study have documented high-risk group for serosal invasion using preoperative predictors. And risk stratification for serosal invasion through the combination with imaging studies may collaboratively improve the accuracy of preoperative assessment, reduce the number of eligible patients for further staging laparoscopy, and optimize therapeutic strategy for each individual patient prior to surgery.

• Tuberculosis and Respiratory Diseases
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• v.72 no.6
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• pp.493-500
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• 2012

Background: This study investigated the clinical characteristics and risk factors of the severity of pandemic influenza A (H1N1) 2009 infection in pediatric patients in Busan and Gyeongsangnam-do. Methods: Cases of influenza A (H1N1) 2009 in patients under the age of 18 years, confirmed by reverse transcription polymerase chain reaction, at Pusan National University Hospital and Pusan National University Yangsan Hospital from the last week of August 2009 through the last week of February 2010 were retrospectively analyzed. Results: Of the 3,777 confirmed cases of influenza A (H1N1) 2009, 2,200 (58.2%) were male and 1,577 (41.8%) were female. The average age of the patients was $8.4{\pm}4.8$ years. The total cases peaked during 44th to 46th week. Most of the patients were in the 5- to 9-year-old age group. Oseltamivir was administered to 2,959 (78.3%) of the patients. 221 patients (5.9%) were hospitalized, age an average of $6.7{\pm}4.5$ years. The average duration of hospitalization was $7.4{\pm}5.6$ days. One hundred cases (45.2%) had pneumonia. Risk factors for hospitalization included male gender, <2 years of age, and underlying disease. Children with asthma were at very high risk of hospitalization, over 20 times the non-asthmatic children (odds ratio [OR], 21.684; confidence interval [CI], 13.295~39.791). Likewise the children with neurologic deficits faced a 16 times higher risk (OR, 15.738; CI, 7.961~31.111). Ten of the patients (4.5%) were admitted to the intensive care unit, and eight (3.6%) required mechanical ventilation. Conclusion: Of the pediatric patients with pandemic influenza A (H1N1) 2009, most of the patients were in the 5- to 9-year-old age group. Risk factors for hospitalization included male gender, <2 years of age, and underlying disease. The most common complication was pneumonia. The very high risk of severe morbidity in children with asthma or neurologic disease shows the critical importance of targeted vaccine coverage, special awareness and swift care by both guardians and primary care providers.

• Korean Journal of Construction Engineering and Management
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• v.19 no.2
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• pp.25-37
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• 2018

In recent times, private sector allocates the risk between private sector investors in terms of equity transaction and agreement transaction. The additional risk-allocation have made the cash flows of private sector investors fluctuated and some of the PPP projects delayed. Therefore, analyzing the impact of the risk reallocation between private sector investors on their cash flows is critical for encouraging the private sector participants. In this study, a model to evaluate the financial viability of PPP project is developed based on the discounted cash flow analysis. The model can analyze the variability by equity and agreement transaction by identifying key variables of equity transaction, influence factors of agreement transaction, and relationship between the transactions and investor's profitability. It is expected that the private sector can determine the investment decision for PPP projects when the risk reallocation is occurred.

• Journal of Preventive Medicine and Public Health
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• v.55 no.1
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• pp.37-48
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• 2022

Objectives: Depression is a frequent complication of type 2 diabetes mellitus. This study aimed to investigate the relationship between low social support and risk for depression in people with type 2 diabetes through a meta-analysis. Methods: PubMed, ProQuest, SpringerLink, ScienceDirect, Scopus, the Cochrane Library, Embase, and Google Scholar were searched for English-language articles published up to 2021. Pooled adjusted odds ratios (aORs) were calculated using a random-effect model with 95% confidence intervals (CIs). Heterogeneity was evaluated by using the Cochrane Q test and I² statistics. The risk of publication bias was estimated using a funnel plot, the Egger test, and the Begg test. The Joanna Briggs Institute Critical Appraisal Tools were used to assess the quality of evidence and the risk of bias. Results: Eleven studies were included in this meta-analysis, containing a total of 3151 people with type 2 diabetes mellitus. The pooled analysis showed that people with type 2 diabetes mellitus who had low social support had twice as high a risk of depression as those with high social support (aOR, 2.02; 95% CI, 1.51 to 2.70; p<0.001). A random-effect model was used because the heterogeneity was high (I² = 87%). Conclusions: Low social support was found to increase the risk of depression among people with type 2 diabetes mellitus. Further investigation into factors that may moderate this relationship is required.