• 재무관리연구
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• 제24권4호
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• pp.135-161
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• 2007

본 연구는 1997년 1월 1일부터 2006년 12월 31일까지 한국증권선물거래소의 유가증권시장과 코스닥시장에 상장된 IPO 기업을 대상으로 배당개시결정의 3가지 측면, 즉, 배당개시 여부, 배당수준 및 배당개시시점의 결정요인을 실증분석 하였으며, 주요한 분석결과는 다음과 같다. 첫째, 주요 배당이론, 즉, 잔여배당이론, 배당신호이론, 대리인이론, 케이터링이론, 거래비용이론 등에서 제시된 배당결정요인들은 IPO 기업의 배당개시결정에도 유의한 영향을 미친다. 성장기회 변수인 M/B 비율과 R&D지출 비율이 낮을수록, 수익성 변수인 EBITDA 비율이 높을수록, 거래량회전율이 낮을수록, 그리고 배당프리미엄이 높을수록 배당개시확률은 높아진다. 둘째, 주요 배당이론에서 제시된 배당결정요인 중에서 성장기회 변수와 수익성 변수는 IPO 기업의 배당수준결정에도 유의한 영향을 미친다. 즉, 성장기회 변수인 R&D지출 비율이 낮을수록, 그리고 수익성 변수인 EBITDA 비율이 높을수록 배당수준이 증가한다. 셋째, 배당개시확률을 증가시키는 요인들은 배당개시시점을 단축시키는 요인으로 작용한다. 즉, 성장기회 변수인 R&D지출이 낮을수록, 수익성 변수인 EBITDA 비율이 높을수록, 그리고 거래량 회전율이 낮을수록, 배당개시확률은 증가하고 배당개시시점은 단축된다. 특히, 수익성 변수인 EBITDA 비율 및 거래량회전율은 배당개시시점과 배당지급/연기 결정에 모두 유의한 영향을 미친다. 즉, EBITDA 비율이 높을수록 배당개시시점이 단축되고, 거래량회전율이 높을수록 배당개시시점이 연기된다. 또한 배당개시기업의 대부분은 IPO 후 2년 이내에 배당개시 여부를 결정한다. 따라서 기업이 IPO 후 2년 이내에 배당개시를 하지 않으면 그 이후에는 배당개시를 하지 않을 가능성이 많다.

• Advances in concrete construction
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• 제9권2호
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• pp.149-159
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• 2020

The present work proposes new engineering models for determining corrosion initiation time in concrete reinforcing steels in marine environment. The models are based on Fick's second law that is commonly used for chloride diffusion. The latter is based on deterministic analyses involving the most influencing parameters such as distance of the concrete structure from the seaside, depth of steel concrete cover, ambient temperature, relative humidity and the water-cement ratio. However, a realistic corrosion initiation time cannot be estimated because of the uncertainties associated to the different parameters of the models. Therefore a reliability approach using FORM/SORM method has been applied to develop the proposed engineering models integrating a limit state function and a reliability index β. As a result, the corrosion initiation time is expressed by new exponential engineering models where the uncertainties are associated to the model parameters. The main emerging result is a realistic decision tool for corrosion planning inspection.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2005년도 봄학술 발표회 논문집(II)
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• pp.249-252
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• 2005

Chloride ingress is a common cause of deterioration of reinforced concrete structures. Modeling the chloride ingress is an important basis for designing reinforced concrete structures and for assessing the reliability of an existing structure. The modelling is also needed for predicting the deterioration of a reinforced structure. This paper presents an approach for the probabilistic modeling of the chloride-induced corrosion of reinforcement steel in concrete structures that takes into account the uncertainties in the physical models. The parameters of the models are modeled as random variables and the distribution of the corrosion time and probability of corrosion are determined by using Monte Carlo simulation. The predictions of the proposed model is very effective to do the decision-making about initiation time and deterioration degree.

• 콘크리트학회논문집
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• 제17권6호
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• pp.1045-1051
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• 2005

For critical structures and application, where a given reliability must be met, it is necessary to account for uncertainties and variability in material properties, structural parameters affecting the corrosion process, in addition to the statistical and decision uncertainties. This paper presents an approach to the fuzzy arithmetic based modeling of the chloride-induced corrosion of reinforcement in concrete structures that takes into account the uncertainties in the physical models of chloride penetration into concrete and corrosion of steel reinforcement, as well as the uncertainties in the governing parameters, including concrete diffusivity, concrete cover depth, surface chloride concentration and critical chloride level for corrosion initiation. The parameters of the models are regarded as fuzzy numbers with proper membership function adapted to statistical data of the governing parameters and the fuzziness of the corrosion time is determined by the fuzzy arithmetic of interval arithmetic and extension principle

• Journal of Preventive Medicine and Public Health
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• 제55권2호
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• pp.182-192
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• 2022

Objectives: Understanding the factors influencing mothers' decision to breastfeed their infants is essential to formulate effective breastfeeding interventions. This study explored the determinants of optimal breastfeeding indicators in Indonesia. Methods: We used the 2017 Indonesia Demographic and Health Survey to analyze factors associated with early initiation of breastfeeding, exclusive breastfeeding (EBF), and continued breastfeeding at 1 year (CBF-1) and 2 years (CBF-2). Multivariate logistic regression models were used to examine bio-demographic, socio-cultural, and behavioral characteristics associated with breastfeeding after considering the survey design effect. Results: The risk of delayed breastfeeding initiation was higher among infants who were born smaller, first-born children, were delivered via cesarean delivery, and did not have immediate skin-to-skin contact (p<0.01). Infant's age, birth pattern, household wealth index, and the mother's occupation and smoking status were predictors of EBF (p<0.05). CBF-1 was less common among first-time mothers and those working in the non-agricultural sector, mothers from wealthier families, and mothers who had cesarean deliveries (p<0.01). Infant's age was negatively associated with CBF-2 (adjusted odds ratio [aOR], 0.85; 95% confidence interval [CI], 0.74 to 0.99). Mothers attending college were less likely to practice CBF-2 than those with no education or primary education (aOR, 0.45; 95% CI, 0.26 to 0.77). The absence of postnatal visits was a risk factor for CBF-1 and CBF-2 (p<0.05). Conclusions: Breastfeeding interventions in Indonesia should pay particular attention to at-risk groups such as women from wealthier families, working outside the agricultural sector, and with a higher education level. Nutrition-sensitive programs (e.g., postnatal care and smoking cessation) should also be encouraged.

• 대한응급의학회지
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• 제29권6호
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• pp.663-670
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• 2018

Objective: Radio-contrast abdomino-pelvic computed tomography (APCT) is considered the gold standard diagnostic tool for an acute abdomen in the emergency department. On the other hand, APCT has a risk of contrast-induced nephropathy. Emergency physicians evaluate the creatinine (Cr) level prior to taking a APCT for the above reason but it takes time to evaluation the serum Cr level. This study hypothesized that Cr measured by a point-of-care test (POCT) can shorten the time to making clinically important decisions for patients with an acute abdomen. Methods: This prospective randomized study was conducted between March 2017 and October 2017. The subjects were divided into two groups (Cr measured by laboratory vs. Cr measured by POCT). To analyze the clinical acceptability for creatinine, agreement was demonstrated graphically by Bland-Altman plots. This study compared the time to make a clinically important decision by physicians and the length of stay at the emergency department in both groups. Results: A total of 76 patients were eligible for the study, 38 patients were assigned to each group. There was no statistically significant difference in the time to the first medical examination (P=0.222) and emergency department stay time (P=0.802). On the other hand, the time to recognition of the Cr level (P<0.001), time to performing APCT (P<0.001), time to decision making (P<0.001), and time to initiation of treatment (P<0.001) were shortened significantly in the point-of-care creatinine group. Conclusion: In this study, the POCT for creatinine can allow rapid decision making by shortening the time to performing the radio-contrast APCT than the laboratory for patients with an acute abdomen.

• 한국의료질향상학회지
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• 제25권1호
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• pp.43-51
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• 2019

Purpose: The time lag between the decision to initiate continuous renal replacement therapy (CRRT) and its actual initiation remains a major barrier in our intensive care units. We developed a CRRT pop-up chart on EMR for managing CRRT machines. Methods: This study measured time interval between the decision to prepare the CRRT machine and the actual use of the machine before and after using a CRRT pop-up chart. This study conducted a questionnaire of the medical staff to assess the changes in the quality of CRRT preparation. Results: A total of 95 patients on CRRT is analyzed. The time to find an available CRRT machine is decreased by 24.6%. The time to move a CRRT machine to the patient's bedside is decreased by 55.8%. Medical surveys of 44 nurses gave the following results. 1) The time to apprehend machines for 1 to 3 minutes is improved from 29.5% to 81.8%, and the time to apprehend machines over 3 minutes is decreased from 70.5% to 18.2%. 2) The number (6-all) of known machine locations is improved from 22.7% to 63.4%. 3) Interruption of a nurse's work due to telephone calls asking for the possession of movable CRRT equipment also is improved. Scores of 1-4 are improved from 15.9% to 41%. Scores of 5-7 are reduced from 52% to 15.9%. Conclusions: CRRT pop-up chart is shortened the time lag of CRRT machine preparation, reduced the nurse's phone workload and helped to improve the quality of CRRT care.

• Journal of Chest Surgery
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• 제57권3호
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• pp.272-280
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• 2024

Background: The phenomenon known as the "weekend effect" impacts various medical disciplines. We compared outcomes between regular hours and off hours to investigate the presence of the weekend effect in extracorporeal cardiopulmonary resuscitation (ECPR). Methods: Between January 2018 and December 2020, 159 patients at our center were treated with veno-arterial extracorporeal membrane oxygenation (ECMO) for cardiac arrest. We assessed the time required for ECMO preparation, the rate of successful weaning, and the rate of in-hospital mortality. These factors were compared among regular hours ("daytime": weekdays from 7:00 AM-7:00 PM), off hours on weekdays ("nighttime": weekdays from 7:00 PM-7:00 AM), and off hours on weekends and holidays ("weekend": Fridays at 7:00 PM to Mondays at 7:00 AM). Results: The time from the recognition of cardiac arrest to the arrival of the ECMO team was shortest for the daytime group and longest for those treated over the weekend (daytime, 10.0 minutes; nighttime, 12.5 minutes; weekend, 15.0 minutes; p=0.064). The time from the ECMO team's arrival to ECMO initiation was shortest for the daytime and longest for the nighttime group (daytime, 13.0 minutes; nighttime, 18.5 minutes; weekend, 14.0 minutes; p=0.028). No significant difference was observed in the rate of successful ECMO weaning (daytime, 48.3%; nighttime, 39.5%; weekend, 36.1%; p=0.375). Conclusion: In situations involving CPR, the time to arrival of the ECMO team was longer during off hours. Furthermore, ECMO insertion required more time at night than during the other periods. These findings warrant specific training in decision-making and emergent ECMO insertion.

• Journal of Korean Neurosurgical Society
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• 제39권6호
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• pp.471-474
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• 2006

Objective : Neuroimaging data are of paramount importance in making correct diagnosis. We herein evaluate the clinical usefulness of image transfer using cellular phones to facilitate neurological diagnosis and decision-making. Methods : Selected images from CT, MRI scans, and plain films obtained from 50 neurosurgical patients were transferred by cellular phones. A cellular phone with a built-in 1,300,000-pixel digital camera was used to capture and send the images. A cellular phone with a 262,000 color thin-film transistor liquid crystal display was used to receive the images. Communication between both cellular phones was operated by the same wireless protocol and the same wireless internet service. We compared the concordance of diagnoses and treatment plans between a house staff who could review full-scale original films and a consultant who could only review transferred images. These finding were later analyzed by a third observer. Results : The mean time of complete transfer was $2{\sim}3\;minutes$. The quality of all images received was good enough to make precise diagnosis and to select treatment options. Transferred images were helpful in making correct diagnosis and decision making in 49/50 [98%] cases. Discordant result was caused in one patient by improper selection of images by the house staff. Conclusion : The cellular phone system was useful for image transfer and delivery patient's information, leading to earlier diagnosis and initiation of treatment. This usefulness was due to sufficient resolution of the built-in camera and the TFT-LCD, the user-friendly features of the devices, and their low cost.

• Steel and Composite Structures
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• 제45권3호
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• pp.389-408
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• 2022

Residual capacity is defined as the load carrying capacity of an RC column after undergoing severe damage. Evaluation of residual capacity of RC columns is necessary to avoid damage initiation in RC structures. The central aspect of the current research is to propose an empirical formula to estimate the residual capacity of RC columns after undergoing severe damage. This formula facilitates decision making of whether a replacement or a repair of the damaged column is adequate for further use. Available literature mainly focused on the simulation of explosion loads by using simplified pressure time histories to develop residual capacity of RC columns and rarely simulated the actual explosive. Therefore, there is a gap in the literature concerning general relation between blast damage of columns with different explosive loading conditions for a reliable and quick evaluation of column behavior subjected to blast loading. In this paper, the Arbitrary Lagrangian Eulerian (ALE) technique is implemented to simulate high fidelity blast pressure propagations. LS-DYNA software is utilized to solve the finite element (FE) model. The FE model is validated against the practical blast tests, and outcomes are in good agreement with test results. Multivariate linear regression (MLR) method is utilized to derive an analytical formula. The analytical formula predicts the residual capacity of RC columns as functions of structural element parameters. Based on intensive numerical simulation data, it is found that column depth, longitudinal reinforcement ratio, concrete strength and column width have significant effects on the residual axial load carrying capacity of reinforced concrete column under blast loads. Increasing column depth and longitudinal reinforcement ratio that provides better confinement to concrete are very effective in the residual capacity of RC column subjected to blast loads. Data obtained with this study can broaden the knowledge of structural response to blast and improve FE models to simulate the blast performance of concrete structures.