• Journal of Chest Surgery
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• v.39 no.6 s.263
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• pp.449-455
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• 2006

Background: Female sex was known to be a risk factor for mortality after coronary bypass grafting (CABG), and women showed higher in-hospital mortality than men. Material and Method: Between 1992 and 1996, 147 consecutive patients (98 men and 49 women) undergoing CABG were included in the study. Most patients had undergone CABG with left internal thoracic artery and saphenous vein under cardiopulmonary bypass. We examined the influence of gender on survival after CABG and looked for risk factors for survival. Result: There was no in-hospital mortality in women, but 3 death (3.0%) in men. During the mean follow-up period of $138.5{\pm}23.0$ months, mortality was lower in women than in men (20.4% vs 44.9%, p=0.004), and the most common cause of death in women was chronic renal failure (40%). Survival in women at 1, 5, 10, and f4 years was 100%, $98.0{\pm}2.0%,\;81.2{\pm}5.6%,\;and\;78.4{\pm}6.1%$, respectively, which was better than in men (p=0.004). Although preoperative left ventricular ejection fraction was higher in women than in men, this did not affect early and long-term survival difference between two sexes (p=0.15). Risk factor for long-term survival in women was diabetes (p=0.033) and in men number of diseased coronary artery (p=0.006). Conclusion: Long-term survival after CABG was better in women than men. Risk factor for long-term survival in women was morbid disease rather than cardiac disease.

• The Korean Journal of Pain
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• v.28 no.2
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• pp.75-87
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• 2015

Background: Lumbar discogenic pain without pain mediated by a disc herniation, facet joints, or the sacroiliac joints, is common and often results in chronic, persistent pain and disability. After conservative treatment failure, injection therapy, such as an epidural injection, is frequently the next step considered in managing discogenic pain. The objective of this systematic review is to determine the efficacy of lumbar epidural injections in managing discogenic pain without radiculopathy, and compare this approach to lumbar fusion or disc arthroplasty surgery. Methods: A systematic review of randomized trials published from 1966 through October 2014 of all types of epidural injections and lumbar fusion or disc arthroplasty in managing lumbar discogenic pain was performed with methodological quality assessment and grading of evidence. The level of evidence was based on the grading of evidence criteria which, was conducted using 5 levels of evidence ranging from levels I to V. Results: Based on a qualitative assessment of the evidence for both approaches, there is Level II evidence for epidural injections, either caudal or lumbar interlaminar. Conclusions: The available evidence suggests fluoroscopically directed epidural injections provide long-term improvement in back and lower extremity pain for patients with lumbar discogenic pain. There is also limited evidence showing the potential effectiveness of surgical interventions compared to nonsurgical treatments.

• Radiation Oncology Journal
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• v.33 no.3
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• pp.172-178
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• 2015

Purpose: To investigate clinical outcomes of synchronous head and neck and esophageal cancer (SHNEC). Materials and Methods: We retrospectively reviewed 27 SHNEC patients treated with curative intent at a single institution. The treatment modality for individual cases was usually determined on a case by case basis. Results: The median follow-up duration for the surviving patients was 28.2 months. The most common site of head and neck cancer was hypopharyngeal carcinoma (n = 21, 77.7%). The lower esophagus was the most common location of esophageal carcinoma (n = 16, 59.3%). The 2-year progression-free survival (PFS) and overall survival (OS) rates were 57.5% and 39.6%. Major pattern of failure was locoregional recurrence in the study patients. Esophageal cancer stage, the Eastern Cooperative Oncology Group (ECOG) performance status, and pretreatment weight loss were significant prognostic factors for OS in univariate analysis. Treatment-related death was observed in two patients, and one patient developed a grade 4 late treatment-related complication. Conclusion: Although the survival outcome for SHNEC is poor, long-term survival might be achievable with aggressive treatment with stage I-II esophageal cancer and good performance.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.8 no.6
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• pp.173-179
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• 2009

Recently, the super capacitor(EDLC) which has drawn attention as a new energy storage element has a lot of advantage such as no maintenance, long lifetime and quick charge/discharge characteristics with large current. The objective of this paper is propose a parameter measurement method to detect the changes in equivalent series resistor (ESR) and the capacitance value of a super capacitor in order to analysis the internal characteristic and worn-out state of a super capacitor. For proposed method, only the capacitor voltage measurement using simple analog switch is required. In addition, experimental results of voltage sag compensation system in order to compensate the input voltage drop during short-term power interruption adopted super capacitor are presented.

• Journal of the Korean Home Economics Association
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• v.43 no.3 s.205
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• pp.147-159
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• 2005

The purpose of this study was to analyze the effect of justice (distributive, interactional, and procedural) perception of e-service recovery in restaurant businesses on e-service recovery satisfaction, negative word of mouth, trust, and commitment. We designed a quasi-experimental study using eight different scenarios of justice application. One of the eight scenarios was distributed to each respondent to read, and the respondent then answered regarding feelings and subsequent action. Data analysis was based on 232 usable responses. The results imply that interactional justice is more important than other forms of justices in e-service recovery of restaurant businesses, indicating that restaurants must approve the service failure, make an apology to the customer, and maintain a courteous attitude at all times. In addison, the restaurant has to consider an e-service recovery program as a long-term strategy because the effect of e-service recovery in restaurant businesses grows slowly and takes time-consuming effort.

• Computers and Concrete
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• v.26 no.1
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• pp.11-20
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• 2020

Concrete are the most widely used manmade materials for infrastructure construction across the world. These constructions gradually aged and damaged due to long-term use. However, there does not exist an efficient concrete recycling method with low energy consumption. In this study, concrete was regarded as a heterogeneous material composed of coarse aggregate and cement mortar. And the failure mode of concrete under ultrasonic dynamic loading was investigated by finite element (FE) analysis. Simultaneously, a 3D random aggregate concrete model was programmed by APDL and imported into ABAQUS software, and the damage plastic constitutive model was applied to each phase to study the damage law of concrete under dynamic loading. Meanwhile, the dynamic damage process of concrete was numerically simulated, which observed ultrasonic propagating and the concrete crushing behavior. Finally, the FE simulation considering the influence of different aggregate volume and aggregate size was carried out to illustrate the damage level of concrete.

• Journal of the Korean GEO-environmental Society
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• v.5 no.1
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• pp.5-12
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• 2004

Soft foundation is extensively distributed in coastal areas including our local regions. Embankment load on such soft foundation causes displacement due to lack of base ground supports. Long-term consolidation can result in settlement and destruction of shear failure and structure. Therefore, a variety of vertical drain methods are applied to construction sites to prevent base from breaking and changing for secure construction. This study analyzed the patterns of changes displacement to determine efficient range of improvement since range of vertical drain material determines vertical and horizontal changes based on the width range of under ground improvement. Changes of intensity with distance from embankment edge were also analyzed in the field study of embankment slope.

• Nuclear Engineering and Technology
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• v.53 no.5
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• pp.1524-1533
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• 2021

The structural stability of a waste package is essential for containing radioactive waste for the long term in a repository. A silo-type disposal facility would require more severe verification for the structural integrity, because of radioactive waste packages staked with several tens of meters and overburdens of crushed rocks and shotcretes. In this study, structural safety was analyzed for a silo-type repository, located approximately 100 m below sea level in Gyeongju, Korea. Finite element simulation was performed to investigate the influence of the loads from the backfilling materials and waste package stacks on the mechanical stress of the disposed of wastes and containers. It was identified that the current design of the waste package and the compressive strength criterion for the solidified waste would not be enough to maintain structural stability. Therefore, an enhanced criterion for the compressive strength of the solidified waste and several reinforced structural designs for the disposal concrete container were proposed to prevent failure of the waste package based on the results of parametric studies.

• International conference on construction engineering and project management
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• 2022.06a
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• pp.3-10
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• 2022

An estimated investment gap of $176 billion needs to be filled over the next ten years to improve America's inland waterway transportation systems. Many of these infrastructure systems are now beyond their original 50-year design life and are often behind in maintenance due to funding constraints. Therefore, long-term maintenance strategies (i.e., asset management (AM) strategies) are needed to optimize investments across these waterway systems to improve their condition. Two common AM strategies include policy-driven maintenance and performance-driven maintenance. Currently, limited research exists on selecting the optimal AM approach for managing inland waterway transportation assets. Therefore, the goal of this study is to provide a decision model that can be used to select the optimal alternative between the two AM approaches by considering key uncertainties such as asset condition, asset test results, and asset failure. We achieve this goal by addressing the decision problem as a single-criterion problem, which calculates each alternative's expected value and certain equivalence using allocated monetary values to determine the recommended alternative for optimally maintaining navigable waterways. The decision model considers estimated and predicted values based on the current state of the infrastructure. This research concludes that the performance-based approach is the optimal alternative based on the expected value obtained from the analysis. This research sets the stage for further studies on fiscal constraints that will effectively optimize these assets condition.

• Korean Medical Education Review
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• v.25 no.2
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• pp.119-125
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• 2023

Pusan National University School of Medicine (PNUSOM) began analyzing the cohort of pre-medical students admitted in 2015 and has been conducting purposeful analyses for the past 3 years. The aim of this paper is to introduce the process of cohort establishment, cohort composition, and the utilization of cohort analysis results. PNUSOM did not initially form a cohort with a purpose or through a systematic process, but was able to collect longitudinal data on students through the establishment of a Medical Education Information System and an organization that supports medical education. Cohort construction at our university is different in terms of a clear orientation toward research questions, flexibility in cohort composition, and subsequent guideline supplementation. We investigated the relevance of admission factors, performance improvements, satisfaction with the educational environment, and promotion and failure rate in undergraduate students, as well as performance levels and career paths in graduates. The results were presented to the Admissions Committee, Curriculum Committee, Learning Outcomes Committee, and Student Guidance Committee to be used as a basis for innovations and improvements in education. Since cohort studies require long-term efforts, it is necessary to ensure the efficiency of data collection for graduate cohorts, as well as the validity and ethics of the study.