• The Journal of Korean Academy of Prosthodontics
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• v.39 no.1
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• pp.25-36
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• 2001

Among the numerous factors contributing to implant failure, the most common are infection, failure of proper healing and overload. These factors may occur combined. Implant fractures are one of the complications resulting from overload. Implant fracture is not a common feature, but once it occurs it causes very unpleasant circumstances for the patient as well as for the practitioner. Only few studies have been reported regarding this subject. Thus, little is known about its solutions. It is important that analyzing reasons for implant fracture and finding appropriate solutions. Factors leading to implant fracture are design, material defects, nonpassive fit of prosthetic framework and biomechanical overload. Previous studies have reported that implant fractures ares associated with marginal bone loss and occur mostly in the posterior regions and that most patients showing parafunctional habits also have implant fracture. Abutment and gold screw loosening or fracture were also observed in some of the cases previous to implant fracture. Similar observations were seen in our hospital as well. The following cases will present implant fracture cases which have been successfully treated regarding function and biomechanics. This was achieved by means of using increased number of futures, increasing fixture diameter and establishing proper occlusion.

• Journal of Ecology and Environment
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• v.38 no.4
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• pp.415-424
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• 2015

This research was conducted to reveal the characteristics of breeding ecology of oriental scops owl (Otus sunia stictonotus) inhabiting in South Korea according to the nest types during the breeding season from march to October for two years (2011 and 2012). Oriental scops owl nested in woodpecker's nest holes (46.1%), natural tree holes (38.5%), and artificial wood boxes (15.4%). These nests were located on following trees: Zelkova serrata, Paulownia coreana, Celtis sinensis, Salix chaenomeloides, Salix babylonica, Fraxinus rhynchophylla, Robinia pseudoacacia and Platanus occidentalis. The hatching success was 91.4%, fledging success was 83.0%, and breeding success was 75.9%. The factors of the breeding failure were falling (57.1%), abandonment (28.6%), hatching failure (7.1%), and others with unknown cause of death (7.1%). According to nest types, the fledging success (69.2%) of woodpecker's nest holes were low and the hatching success (79.2%) of natural tree holes were also low due to hatching failure and abandonment. However, hatching success, fledging success, breeding success were high in the artificial nests as all the eggs hatched and succeeded in fledging. Therefore, we suggested that artificial nests can cover the weaknesses of natural nests as well as increasing the breeding success. However, long-term research on installation place, height, and hole sizes of the artificial nest are required in order to clearly reveal the effects on the breeding success of oriental scops owl.

• Journal of Chest Surgery
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• v.44 no.6
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• pp.418-422
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• 2011

Background: It has recently become most general to use the small bore catheter to perform closed thoracostomy in treating iatrogenic pneumothorax. This study was performed for analysis of the efficacy of treatment methods by using small bore catheter such as 7 F (French) central venous catheter, 10 F trocar catheter, 12 F pigtail catheter and for analysis of the appropriateness of each procedure. Materials and Methods: From March 2007 to February 2010, Retrospective review of 105 patients with iatrogenic pneumothorax, who underwent closed thoracostomy by using small bore catheter, was performed. We analyzed the total success rate for all procedures as well as the individual success rate for each procedure, and analyzed the cause of failure, additional treatment method for failure, influential factors of treatment outcome, and complications. Results: The most common causes of iatrogenic pneumothorax were presented as percutaneous needle aspiration(PCNA) in 48 cases (45.7%), and central venous catheterization in 26 cases (24.8%). The mean interval to thoracostomy after the procedure was measured as 5.2 hours (1~34 hours). Total success rate of thoracostomy was 78.1%. The success rate was not significantly difference by tube type, with 7 F central venous catheter as 80%, 10 F trocar catheter as 81.6%, and 12 F pigtail catheter as 71%. Twenty one out of 23 patients that had failed with small bore catheter treatment added large bore conventional thoracostomy, and another 2 patients received surgery. The causes for treatment failure were presented as continuous air leakage in 12 cases (52.2%) and tube malfunction in 7 cases (30%). The causes for failure did not present significant differences by tube type. Statistically significant factors affecting treatment performance were not discovered. Conclusion: Closed thoracostomy with small bore catheter proved to be effective for iatrogenic pneumothorax. The success rate was not difference for each type. However, it is important to select the appropriate catheter by considering the patient status, pneumothorax aspect, and medical personnel in the cardiothoracic surgery department of the relevant hospital.

• Radiation Oncology Journal
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• v.32 no.3
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• pp.125-131
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• 2014

Purpose: We reviewed treatment outcomes and prognostic factors for patients with salivary ductal carcinoma (SDC) treated with surgery and postoperative radiotherapy from 2005 to 2012. Materials and Methods: A total of 16 patients were identified and 15 eligible patients were included in analysis. Median age was 61 years (range, 40 to 71 years) and 12 patients (80%) were men. Twelve patients (80%) had a tumor in the parotid gland, 9 (60%) had T3 or T4 disease, and 9 (60%) had positive nodal disease. All patients underwent surgery and postoperative radiotherapy. Postoperative radiotherapy was delivered using 3-dimensional conformal radiotherapy or intensity-modulated radiotherapy. Locoregional failure-free survival (LRFFS), distant failure-free survival (DFFS), progression-free survival (PFS), and overall survival (OS) were calculated using the Kaplan-Meier method. Differences in survival based on risk factors were tested using a log-rank test. Results: Median total radiotherapy dose was 60 Gy (range, 52.5 to 63.6 Gy). Four patients received concurrent weekly chemotherapy with cisplatin. Among 10 patients who underwent surgery with neck dissection, 7 received modified radical neck dissection. With a median follow-up time of 38 months (range, 24 to 105 months), 4-year rates were 86% for LRFFS, 51% for DFFS, 46% for PFS, and 93% for OS. Local failure was observed in 2 patients (13%), and distant failure was observed in 7 (47%). The lung was the most common involved site of distant metastasis. Conclusion: Surgery and postoperative radiotherapy in SDC patients resulted in good local control, but high distant metastasis remained a major challenge.

• Tunnel and Underground Space
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• v.18 no.4
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• pp.289-299
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• 2008

Based on the case study on the causes for the failure of cutting slope composed of weathered rock and soil, the factors influencing the design of a cutting slope have been examined, This type of rock and soil is widely distributed on the region whose parent rock is granite. To analyze the stability of the cutting slope, the following series of progress has been conducted: (1) ground characterization by geological survey and ground investigation, (2) the safety factor examination by limit equilibrium analysis and numerical analysis and (3) the comparison and analysis of rainfall and failure history. As a result, the main factors to cause the failure is determined to be the decrease of shear strength in the upper parts whose ground condition is weakened during localized heavy rain. Moreover, the analysis indicates the failure is also closely related to the groundwater inflow path. On the base of this investigation, a reinforcement method is proposed to ensure the stability of the cutting slope.

• Journal of Korean Biological Nursing Science
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• v.21 no.1
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• pp.22-36
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• 2019

Purpose: Even though advanced heart failure (HF) severely affects the patient's health-related quality of life (HRQoL), there is little information regarding this issue. This review is aimed to describe the relevant clinical characteristics of patient with advanced HF and identify factors influencing HRQoL in these patients. Methods: Empirical articles were searched from electronic databases issued from January 2000 to June 2018 with using the key terms 'heart failure' and 'quality of life'. There were a total of 22 articles that met the inclusion criteria and were analyzed for this study. Results: First, nine studies among 22 studies clearly stated that their participants were samples of patients with advanced HF. Most reviewed studies showed the New York Heart Association (NYHA) class as the criteria for identifying advanced HF. Second, the level of HRQoL varied depending on the measurement tools utilized by the researchers. Third, the NYHA class, gender, and symptoms were mainly associated with HRQoL in patients with advanced HF. Also, nurse- or physician-led intervention, exercise, spiritual-focused intervention, and palliative care improved the HRQoL of the patients with advanced HF. Conclusion: This study found that the clear application of criteria for advanced HF and the development of advanced HF-specific HRQoL measurement was needed. Prospective studies should be considered for identifying differences in the levels and factors influencing HRQoL in patients with early stage or advanced HF to design patient-centered care.

• The Korean Journal of Franchise Management
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• v.11 no.3
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• pp.19-26
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• 2020

Purpose: The old axion to put the customers first (e.g., customers are king, customers are always right) has been taken for granted in the service sector. In addition, many companies in South Korea are providing customer-first education for employees at their contact points to strengthen their competitiveness. However, excessive increase in the psychological power of the customer can lead to a problem of abuse of power, called 'Gap-jil.' Despite these concerns, most companies hardly discard policies to give high priority to customers because of the assumption that it enhances customer satisfaction leading to organizational performance. However, in recent years, some franchise catering companies have posted warnings about the abuse of power by customers, and a movement to pursue a power-balancing between service providers and their customers is spreading. Research design, data, and methodology: This research is conducted to reconsider the principle of the customer-first perspective and to create a basis for arguments that can solve the problem of abuse of power, which is recognized as a serious social problem. In this research, we test and analyze the effect of customers' psychological power in the context of a restaurant on expectation for service and response to service failure. Result: The result of an experimental study shows that the effect of psychological power on customer satisfaction can be somewhat negative. Also, customers with high psychological power are more likely to have high service expectations. Especially high psychological power of customers causes a difference in the expectation level of human factors such as employee attitude, while the difference in expectations of non-human factors such as restaurant atmosphere was not statistically significant. In addition, when customers with high psychological power encounter service failure situation, they are more likely to feel disappointment and regret with a service provider. Meanwhile, the effect of psychological power on complaining behaviors are not significant. Conclusions: The findings of this research provide meaningful implications that the service providers should reconsider their existing corporate culture and management policies that put customers first. In addition, the result of this research is provided meaningful opportunities to review the management philosophy for the company's customers and the education philosophy for the employee education.

• Geomechanics and Engineering
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• v.28 no.3
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• pp.283-298
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• 2022

Landslides triggered by the combination of heavy precipitation and anthropological disturbance in hilly areas cause severe damage to human lives, properties, and infrastructure constructions. A comprehensive investigation of the influencing factors and failure mechanisms of landslides are significant for disaster mitigation and prevention. This paper utilized the combination of detailed geological investigation, physical experimental testing as well as numerical modelling to determine the failure mechanism, and proposed a countermeasures of the Lantian landslide occurred on 2, July 2017. The results reveal that the Lantian landslide is a catastrophic reactivated slide which occurred in an active tectonic region in Southwest China. Because of the unique geological settings, the fully to highly weathered basalts in the study area with well-developed fractures favored the rainwater infiltration, which is the beneficial to slide reactivation. Engineering excavation and heavy precipitation are the main triggering factors to activate the slide motion. Two failure stages have been identified in the landslide. The first phase involves a shallow mass collapse originated at the upper slopes, which extends from the road to platform at rear part, which is triggered by excavation in the landslide region. Subjected to the following prolonged rainfall from 19 June to 2 July, 2017, the pore water pressure of the slope continually increased, and the groundwater table successively rise, resulting in a significant decrease of soil strength which leads to successive large-scale deep slide. Thereinto, the shallow collapse played a significant role in the formation of the deep slide. Based on the formation mechanisms of the landslide, detailed engineering mitigation measures, involving slope cutting, anchor cable frame, shotcrete and anchorage, retaining wall and intercepting ditch were suggested to reduce the future failure risk of the landslide.

• Geomechanics and Engineering
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• v.25 no.3
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• pp.233-243
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• 2021

Rib spalling is a major issue affecting the safety of steeply inclined coal seam. And the failure coal face and support system can be affected with each other to generate a vicious cycle along with inducing large-scale collapse of surrounding rock in steeply inclined coal seam. In order to analyze failure mechanism and propose the corresponding prominent control measures of steeply inclined coal working face, mechanical model based on coal face-support-roof system and mechanical model of coal face failure was established to reveal the disaster mechanism of rib spalling and the sensitive analysis of related factors was performed. Furthermore, taking 3402 working face of Chen-man-zhuang coal mine as engineering background, numerical model by using FLAC3D was built to illustrate the propagation of displacement and stress fields in steeply inclined coal seam and verify the theory analysis as mentioned in this study. The results show that the coal face slide body in steeply inclined working face can be observed as the failure height of upper layer smaller than that of lower layer exhibiting with an irregular quadrilateral pyramid shape. Moreover, the cracks were originated from the upper layer of sliding body and gradually developed to the lower layer causing the final rib spalling. The influence factors on the stability of coal face can be ranked as overlying strata pressure (P) > mechanical parameters of coal body (e.g., cohesion (c), internal fraction angle (φ)) > support strength (F) > the support force of protecting piece (F') > the false angle of working face (Θ). Moreover, the corresponding control measures to maintain the stability of the coal face in the steeply inclined working face were proposed.

• Journal of Chest Surgery
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• v.55 no.2
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• pp.158-167
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• 2022

Background: This study investigated mortality and morbidity in patients requiring postcardiotomy extracorporeal membrane oxygenation (ECMO) support after operations for congenital heart disease (CHD). Methods: CHD patients requiring postoperative ECMO support between May 2011 and May 2021 were retrospectively reviewed. Patients were divided into non-survivors and survivors to hospital discharge. Survival outcomes and associations of various factors with in-hospital death were analyzed. Results: Fifty patients required postoperative ECMO support. Patients' median age and weight at the time of ECMO insertion were 1.85 months (interquartile range [IQR], 0.23-14.5 months) and 3.84 kg (IQR, 3.08-7.88 kg), respectively. Twenty-nine patients (58%) were male. The median duration of ECMO support was 6 days (IQR, 3-12 days). Twenty-nine patients (58%) died on ECMO support or after ECMO weaning, and 21 (42%) survived to hospital discharge. Postoperative complications included renal failure (n=33, 66%), bleeding (n=11, 22%), and sepsis (n=15, 30%). Prolonged ECMO support (p=0.017), renal failure (p=0.005), continuous renal replacement therapy (CRRT) application (p=0.001), sepsis (p=0.012), bleeding (p=0.032), and high serum lactate (p=0.002) and total bilirubin (p=0.017) levels during ECMO support were associated with higher mortality risk in a univariate analysis. A multivariable analysis identified CRRT application (p=0.013) and a high serum total bilirubin level (p=0.001) as independent risk factors for death. Conclusion: Postcardiotomy ECMO should be considered as an important therapeutic modality for patients unresponsive to conventional management. ECMO implementation strategies and management in appropriate patients without severe complications, particularly renal failure and/or liver failure, are crucial for achieving positive outcomes.