• Journal of Chest Surgery
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• v.45 no.5
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• pp.295-300
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• 2012

Background: With growing attention to the aortopathy associated with aortic valve diseases, the number of candidates for accompanying ascending aorta and/or root replacement is increasing among the patients who require aortic valve replacement (AVR). However, such procedures have been considered more risky than AVR alone. This study aimed to compare the surgical outcome of isolated AVR and AVR combined with aortic procedures. Materials and Methods: A total of 86 patients who underwent elective AVR between 2004 and June 2010 were divided into two groups: complex AVR (n=50, AVR with ascending aorta replacement in 24 and the Bentall procedure in 26) and simple AVR (n=36). Preoperative characteristics, surgical data, intra- and postoperative allogenic blood transfusion requirement, the postoperative clinical course, and major complications were retrospectively reviewed and compared. Results: The preoperative mean logistic European System for Cardiac Operative Risk Evaluation (%) did not differ between the groups: $11.0{\pm}7.8%$ in the complex AVR group and $12.3{\pm}8.0%$ in the simple AVR group. Although complex AVR required longer cardiopulmonary bypass ($152.4{\pm}52.6$ minutes vs. $109.7{\pm}22.7$ minutes, p=0.001), the quantity of allogenic blood products did not differ ($13.4{\pm}14.7$ units vs. $13.9{\pm}11.2$ units). There was no mortality, mechanical circulatory support, stroke, or renal failure requiring hemodialysis/filtration. No difference was found in the incidence of bleeding (40% vs. 33.3%) which was defined as red blood cell transfusion ${\geq}5$ units, reoperation, or intentional delayed closure. The incidence of mediastinitis (2.0% vs. 0%), ventilator ${\geq}24$ hours (4.0% vs. 2.8%), atrial fibrillation (18.0% vs. 25.0%), mean intensive care unit stay (34.5 hours vs. 38.8 hours), and median hospital stay (8 days vs. 7 days) did not differ, either. Conclusion: AVR combined with additional aortic or root replacement showed an excellent outcome and recovery course equivalent to that after isolated AVR.

• Childhood Kidney Diseases
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• v.14 no.1
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• pp.32-41
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• 2010

Purpose : Glomerulonephropathy (GN) often manifests as proteinuria and progresses to chronic renal failure without specific therapy. Mesenchymal stem cell (MSC) has been tried as a therapeutic agent in experimental GN, and previous studies showed that administration of MSC concomitantly to the insult inducing GN or via intra-renal administration ameliorated proteinuria. The purpose of this study was to test the therapeutic potential of MSC administered via intravenous route at the time of clinically evident proteinuria. Methods : MSCs were administered intravenously via tail vain into the mice with adriamycin (ADR) induced nephropathy (ADR-GN), two weeks after ADR injection when massive proteinuria was evident. To test the capacity of MSC modulate the cytokine production in the inflammatory milieu, the concentrations of IFN-$\gamma$ and IL-10 were measured in the supernatant of in vitro mixed lymphocyte culture (MLC) with or without additional MSC. Results : MSCs administered intravenously into the proteinuric mice with ADR-GN accelerated the recovery of this experimental GN with disappearance of proteinuria in two weeks when the saline treated (control) mice still showed significant proteinuria. The mice treated with MSC also had a tendency of better survival. Addition of MSC decreased IFN-$\gamma$ and increased IL-10 in the supernatant of MLC. Conclusion : This study showed that MSC had a therapeutic potential even when administered in a more clinically relevant setting into a proteinuric glomerulonephropathy model. Further study to verify the mechanism and long-term safety of this phenomenon is required.

• Childhood Kidney Diseases
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• v.17 no.2
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• pp.149-153
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• 2013

We report the case of a 14-year-old girl, diagnosed with atypical thrombotic microangiopathy (TMA). The patient presented with persistent fever, nausea, and newly developed peripheral edema. Her laboratory findings indicated chronic anemia with no evidence of hemolysis, thrombocytopenia, or elevated serum creatinine level. A few days after hospitalization, acute renal failure and fever worsened, and proteinuria developed. On day 40 of hospitalization, she experienced a generalized tonic seizure for 5 min, accompanied by renal hypertension. Brain magnetic resonance imaging revealed posterior reversible leukoencephalopathy syndrome. After steroid pulse therapy, a renal biopsy was performed because of delayed recovery from thrombocytopenia. The biopsy findings showed features of thrombotic microangiopathic hemolysis with fibrinoid change restricted. Current diagnostic criteria for TMA have focused on thrombotic thrombocytopenic purpura and hemolytic uremic syndrome, and diagnosis is based on the clinical presentation and etiology, with the consequence that idiopathic and atypical forms of TMA can be overlooked. Developing effective tools to diagnose TMA, such as studying levels of ADAMTS13 or testing for abnormalities in the complement system, will be the first step to improving patient outcomes.

• Journal of Yeungnam Medical Science
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• v.18 no.1
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• pp.51-58
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• 2001

Background: Cholestatic hepatitis is failure of bile to reach the duodenum with hepatocellular damage and no demonstable obstruction of the major bile ducts. The prognosis is usually good with recovery in less than 4 weeks after withdrawal of the offending drug. However, a prolonged course lasting over 3 months is possible and, in rare cases, progression to ductopenia with development of a vanishing bile duct syndrome occurs. A differential diagnosis with other causes of Chronic liver disease is needed. Materials and Methods: From January 1991 through January 2000, 14 patients diagnosed as cholestatic hepatitis by liver biopsy were included. The possible causative drug, clinical features, laboratory findings, and progression of cholestatic hepatitis were evaluated. The semiquantitative study of liver lesions was performed by two independent observers. Results: Causes of cholestatic hepatitis are 5 cases of oriental medicine, 3 cases of anti-tuberculosis medication, 1 case of ticlopidine and antibiotics and 4 cases of unknown causes. The clinical features of cholestatic hepatitis were jaundice, itching, urine color change, and general weakness. During 6 to 30 months, LFT of 5 patients showed prolonged elevation. Elevated total cholesterol ${\geq}$250 mg/dL in 6 patients, pheripheral blood eosinophilia in 5 patients, auto-antibody positive in 6 patients were observed respectively. The biopsies showed intralobular bilirubinostasis with a mixed portal inflammatory infiltration. Conclusion: In cholestatic hepatitis, durations of abnormal LFT are variable regardless of causative drugs. If cholestatic hepatitis progresses toward chronic course, viral hepatitis, primary biliary cirrhosis, and autoimmune hepatitis should be differentially diagnosed and sequential liver biopsies are needed.

• The Journal of Korean Institute of Next Generation Computing
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• v.15 no.3
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• pp.7-15
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• 2019

Cloud computing markets are rapidly growing as cost savings and business innovation are being carried out through ICT worldwide. In line with this paradigm, the nation is striving to introduce cloud computing in various areas, including the public sector and defense sector, through various research. In the defense sector, DIDC was established in 2015 by integrating military, naval, air and military computing centers, and it provides cloud services in the form of IaaS to some systems in the center. In DIDC and various future cloud defense systems, It is an important issue to ensure availability in cloud defense systems in the defense sector because system failures such as network delays and system resource failures are directly linked to the results of battlefields. However, ensuring the highest levels of availability for all systems in the defense cloud can be inefficient, and the efficiency that can be gained from deploying a cloud system can be reduced. In this paper, we classify and define the level of availability of defense cloud systems step by step, and propose the strategy of introducing Erasure coding and failure acceptance systems, and disaster recovery system technology according to each level of availability acquisition.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.4
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• pp.513-519
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• 2021

Metallic suture anchors are very useful and common fixation devices that are inserted into the target bone to sustain the tendon of a patient with musculus supraspinatus tendon ruptures. On the other hand, the presence of a metallic material prosthesis, such as a metal suture anchor, causes severe MR imaging artifacts, including field distortion, signal loss, and failure of fat suppression. The difference in magnetic susceptibility between metal and other organic materials causes magnetic field distortion surrounding the prosthesis. The resulting magnetic field inhomogeneity makes the images with a lower signal-to-noise ratio and distortion. For a patient with a suture anchor implanted, MR imaging is the golden standard for determining the postoperative prognosis, and a fat-saturation sequence is one of the imaging methods most affected by metal-induced artifacts. In this study, three fat-saturation sequences were compared. Artifact quantification and contrast comparison between the supraspinatus tendon and the surrounding muscle were presented. The images obtained using the STIR pulse sequence showed fewer susceptibility artifacts and better visibility in the supraspinatus tendon and the tissue area. Therefore, the STIR sequence is the most appropriate fat-saturation imaging method for patients with a metallic prosthesis.

• Journal of Navigation and Port Research
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• v.42 no.6
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• pp.478-485
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• 2018

Aids to Navigation (AtoN) is one of the marine traffic safety facilities that promotes the safety of maritime traffic and enhance ship's operational efficiency. However, functional failure of AtoN due to ship's collision or bad weather conditions leads to inconvenience or navigational risk to various users such as the ship operators. For insstance, the largest container port in Korea, Busan Port has experienced a total of 400 AtoN accidents in the past 12 years (2006-2017).Therefore, an average of 20.6 days of recovery time is required, which increases the maritime safety anxiety for AtoN users. is the objective of this study was to present the quantitative support of the users for the prevention of AtoN accidents and the improvement of the feasibility of implementing more efficient management in Korea. A survey was conducted on the users of Busan port areas to investigate general perception of AtoN in general and the accidents that have happened, and to estimate the economic value of navigational risk reduction by implementing effective AtoN management measure. Using the representative non-market valuation method for environmental or public goods known as contingent valuation method (CVM), the economic value granted to users for the AtoN services in Busan port was estimated to at least 16 billion won. Therefore, these finding could be used by AtoN managers and/or policy makers as a valuable data to identify the users' need of various AtoN services including Busan Port and to establish and implement more efficient management plan.

• The Journal of the Korea Contents Association
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• v.19 no.4
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• pp.423-431
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• 2019

This study examines the effect of the liability limitation provision (LLP) adoption on firm's cost behavior. In April 2011, Korea introduced the LLP with the purpose of improving the management efficiency by mitigating the risks caused by the manager's failure to make decisions related to business operation. However, there are concerns that the adoption of LLP may lead the manager's moral hazard, so the need for empirical research to verify the effect of the LLP adoption is emphasized. In this study, we analyze the effect of the LLP adoption empirically, focusing on the cost behavior that is affected by the manager's decision making. From the empirical result, we find that LLP adopted companies have strengthened the cost stickiness of selling, general, and administrative costs rather than non-adopted companies. This suggests that the manager of LLP adopted company makes a more active decision to consider adjusting costs in order to prepare for future recovery in sales when sales is reduced. This study presents empirical evidence to prove the policy validity of the adoption of LLP, and we expect that our results can contribute to the capital market and academia.

• Korean Journal of Cognitive Science
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• v.33 no.4
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• pp.205-228
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• 2022

This study aimed to confirm the effect of social and relational behavior types of robots on human cognition in human-robot interaction. In the experiment, the participants evaluated trust in robots by watching a video on the robot Nao interacting with a human, in which the robot made an error and then made an effort to restore trust. The trust recovery behavior was set as three conditions: an internal attribution in which the robot acknowledges and apologizes for an error, a condition in which the robot apologizes for an error but attributes it externally, and a non-action condition in which the robot denies the error itself and does not take any action for the error. As the result, in all three cases, the error was perceived as less serious when the robot apologized than when it did not, and the ability of the robot was also highly evaluated. These results provide evidence that human attitudes towards robots can respond sensitively depending on the robot's behavior and how they overcome errors, suggesting that human perception towards robots can change. In particular, the fact that robots are more trustworthy when they acknowledge and apologize for their own errors shows that robots can promote positive human-robot interactions through human-like social and polite behavior.

• Korean Journal of Culture and Social Issue
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• v.16 no.3
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• pp.241-265
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• 2010

This study reviewed the present state and differences of rehabilitation programs of the gambling addiction by comparing with other psychiatric disorder(including psychotic disability and alcohol addiction). This study also intended to suggest necessities, meanings and inherent fields of the rehabilitation in gambling addiction. First of all, the government and a few gambling industries run clinic centers for gamblers and their families, but have been lacked rehabilitation services for social comeback and adaptation or devaluated rehabilitation services than therapies. Gambling addict didn't have impairments of the cognitive function and their daily abilities was better than any other psychiatric disorders. But Damage of social role or function of gambling addiction was severe. And it is caused by nonadaptive nature of gambling behavior, personality/emotional change through gambling addiction process, and previous personality problem etc. There are many severe failure of social role and its attendant bankrupcy, family's problems and social poverty in gambling addiction, Therefore, important fields in the rehabilitation of gambling addiction should be services for basic social comeback support service, credit recovery support, monetary management, support of rehabilitation of family and vocational rehabilitation. Finally, the significance and critical points of the current study has been discussed as well.