• Proceedings of the Korean Institute of Building Construction Conference
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• 2008.05a
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• pp.99-102
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• 2008

This study investigates the properties of the flow, air content, strength, hydration heat, and the autogenous shrinkage, and the results are summarized as following. As a properties of fresh concrete, the flow increased and the air content decreased as the replacement ratio of BS increased. The time of set delayed as the replacement ratio of BS increased by latent hydraulicity. The compressive strength of hardening concrete was smaller than OPC as the replacement ratio of BS increased at young concrete, however it was more than equal after 28th day and from then on. The rising temperature ratio which occurs by simplicity insulation decreased as the replacement ratio of BS increased, but it increased by latent hydraulicity reaction at the latter half. The length ratio of autogenous shrinkage of OPC was 319×10^-6, however it was shorter when the replacement ratio was 40% as showing 290×10^-6.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2003.11a
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• pp.43-48
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• 2003

This paper investigate that the effect of the concrete containing mineral admixtures(pozzolanic materials such as fly-ash, ground granulated blast-furnace slag, silica fume and meta kaolin) on the resistance properties to chloride ion invasion. The purposed testing procedure was applied to the concrete added mineral admixtures for 3~4 replacement ratios under W/B ratios ranged from 0.40 to 0.55. For the electrical migration test, Tang and Nilsson's method was used to estimate the migration coefficient of chloride ion. As a results, the W/B ratios, kinds of admixture and replacement ratios, water curing periods had a great effect on the migration coefficient of chloride ion, and the optimal replacement ratios of admixture had a limitation for each admixtures. Also, the addition of mineral admixtures by mass(replacement of OPC) enhanced the resistance of the mixture to chloride penetration compared with the plain concrete. The amount of acid soluble chloride ions and water soluble chloride ions were varied with the kinds of mineral admixtures. The compressive strength was shown related to the migration coefficient of chloride ion, the compressive strength increased with the decreasing migration coefficient of chloride ion. Below the 50MPa, the variation of migration coefficient of concrete added mineral admixtures was bigger than plain concrete.

• Journal of Chest Surgery
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• v.28 no.12
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• pp.1122-1131
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• 1995

One hundred eighty-eight patients[August.23,1988,through July.30,1994 underwent aortic[AVR , mitral[MVR , or double [DVR valve replacement with the St.Jude Medical prosthesis. The author analyzed 100 patients with valvular heart disease,who underwent valve replacement with the St.Jude Medical prothesis from 1990 to 1994, at Hanyang University hospital Cardiovascular department. Information on volume and functional change of the heart chamber can be obtained by cardiac echocardiography and cartheterization. Out of 100 patients, 40 patients were male[40% and 60 patients were female [60% . Age ranged from 13 years to 68 years, with mean age of 42.6 years. Mean height was 160.3cm and mean body weight was 54.9Kg. According to NYHA functional classification, class III is most frequent and 60 patients could be classfied under it. MVR [involved Redo MVR was performed in 40 patients, AVR [involved Redo AVR was performed in 18 patients, and DVR [involved Redo DVR was performed in 42 patients. Warfarin [Coumadin anticoagulation was recommended for all patients. Life long warfarin anticoagulation was necessary to all patients who underwent valve replacement with St.Jude Medical prosthesis. Ideal prothrombin time was maintained about 30% during warfarinization. There were no case of mechanical failure. It followed a comparison of echocardiography before and after valve replacement at Hanyang University hospital [30 patients and a preoperative evaluation of cardiac catheterization and angiography [64 patients . The St.Jude Medical cardiac valve is a viable alternative in the surgical therapy of valvular heart disease.

• Journal of Korean Society for Quality Management
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• v.20 no.2
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• pp.33-43
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• 1992

Items are assumed to fail by degradation. An appropriate stochastic model of such item is a cumulative process in which an item can fail only when the total amount of wear exceeds a prespecified failure level. This paper presents replacement policy in which an item is replaced at a certain level of wear before failure or at failure, whichever occurs first. Yet, when measuring the item wear level is very expensive, destructive or time-consuming, it may be economical to use substitutive characteristics that are correlated with the item wear level and relatively inexpensive to measure. The item's wear level could usually be estimated by monitoring such substitutive characteristics only except for a breakdown, which may be observed immediately at its occurrence. The purpose of this paper is to find an optimal periodic replacement policy based on such substitutive characteristics that balance the cost of replacement with the cost of failure and result in a minimum total long-run average cost per unit time. The optimal level of substitutive characteristics to replace the item is obtained. Numerical example illustrate how the model can be used to determine the optimal replacement policy.

• Journal of Chest Surgery
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• v.16 no.4
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• pp.458-469
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• 1983

Between October, 1978, and December, 1982, Glutaraldehyde-stablized pericardial xenografts [Ionescu-Shiley valve] were used for heart valve replacement in 409 patients.[251 mitral, 49 aortic, 11 tricuspid, and 98 multiple valve replacement]. There were 31 early deaths [7.6%], and 371 operative survival were observed for a total of 507.6 years over a period of 1 to 44 months. [mean 17 months]. Actuarial analysis of late results indicates an excepted survival rate at 4 years of 86.25.4% for patients with mitral, 79.37.1% for patients with aortic valve replacement. Actuarial survival rates for total patients at 4 years was 77.88.2%. The rate of systemic embolism has been 1.6% per patient-year for mitral and 1.8% per patient-year for aortic group in the presence of anticoagulation treatment. Among the 6 embolic episodes, 2 patients were died. The incidence of hemorrhagic complication was 1.3% per patient-year for anticoagulated patients. There were 6 confirmed valve failures, five in mitral and one in aortic position. Re-replacement of destructed valve was performed in one patient and others were treated medically. Among the 6 episodes, 3 occurred in children [Below 15 years], it account almost 9 times higher than adult. Our clinical data compare very favorable with those obtained with other available prostheses and tissue valves, but it should be considered to give short-term anticoagulation therapy to hemodynamically stable patients and aortic valve patients, and other prosthetic valve must be considered to use in children.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2003.05a
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• pp.43-48
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• 2003

This paper investigate that the effect of the concrete containing mineral admixtures(pozzaolanic materials such as fly-ash, ground granulated blast-furnace slag, silica fume and meta kaolin) on the resistance properties to chloride ion invasion. The purposed testing procedure was applied to the concrete added mineral admixtures for 3∼4 replacement ratios under W/B ratios ranged from 0.40 to 0.55. For the electrical migration test, Tang and Nilsson's method was used to estimate the migration coefficient of chloride ion. As a results, the W/B ratios, kinds of admixture and replacement ratios, water curing periods had a great effect on the migration coefficient of chloride ion, and the optimal replacement ratios of admixture had a limitation for each admixtures. Also, the addition of mineral admixtures by mass(replacement of OPC) enhanced the resistance of the mixture to chloride penetration compared with the plain concrete. The amount of acid soluble chloride ions and water soluble chloride ions were varied with the kinds of mineral admixtures. The compressive strength was shown related to the migration coefficient of chloride ion, the compressive strength increased with the decreasing migration coefficient of chloride ion. Below the 50MPa, the variation of migration coefficient of concrete added mineral admixtures was bigger than plain concrete.

• Journal of Korean Medicine Rehabilitation
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• v.25 no.2
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• pp.197-203
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• 2015

Objectives The objective of this study is to report the deep vein thrombosis (DVT) after total knee replacement (TKR) in a patient undergoing Korean medical rehabilitation. Methods A female patient who had total knee replacement (TKR) was treated by Korean medical rehabilitation with protocol. After fifteen days treatment, deep vein thrombosis (DVT) was suspected. Therefore, CT venography was performed. Results After Korean medical rehabilitation, pain was decreased. But also occurred deep vein thrombosis (DVT) as a complication. Conclusions We present a case of deep vein thrombosis (DVT) after total knee replacement (TKR) in a patient undergoing Korean medical rehabilitation. There is a limit that this study hasn't sufficient number of cases. Further studies will be needed.

• KDI Journal of Economic Policy
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• v.40 no.3
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• pp.1-44
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• 2018

This paper studies the macroeconomic effects of an enhancement in unemployment benefits in Korea. In particular, I quantify the welfare effect of two specific policy chances which have been mainly discussed among policymakers in recent years: increasing wage replacement rates by 10%p and extending maximum benefit durations by one month. To this end, I build and calibrate an overlapping generation model which reflects the heterogeneity of the unemployed and the specificity of the unemployment insurance (UI) system in Korea. The quantitative analysis conducted here shows that extending maximum benefit durations by one month improves social welfare, whereas increasing wage replacement rates by 10%p deteriorates social welfare. Extending maximum benefit durations is applied to potentially all the UI recipients, including unemployed workers whose wage before job loss is relatively low and whose marginal utility is relatively high. However, increasing wage replacement rates is applied to only a small number of UI recipients whose wage before job loss is relatively high, while the increase in the UI premium is passed onto all of the employed. This study suggests that given the current UI system and economic environment in Korea, it is more desirable to extend maximum benefit durations rather than to increase wage replacement rates in terms of social welfare.

• Proceedings of the KSR Conference
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• 2009.05a
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• pp.91-98
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• 2009

For maintaining railroad, accumulated passing tonnage is a determinant factor of appropriate rail replacement time. Recently, Seoul Metro's rail maintaining system and technology is being improved from previous years, which increasing a standard of rail replacement. Thus, this brings importance of estimating and managing for accumulated passing tonnage. In case of light weighted train such as subway, current method of calculating accumulated passing tonnage has defaults of misrepresenting accumulated passing tonnage data. Because current method is based on the weight of passengers and train., and operation data. In addition, currently there is no mechanical and electronic system that could represent and support the accurate data between heavy and non-heavy traffic area, and accumulated passing tonnage is calculated inaccurately by estimating average value each line. The current method of calculating accumulated passing tonnage misleads to unpredictable data that represent inappropriate rail replacement period, which leads to under or over analyzed replacement period. If accumulated passing tonnage is over estimated, rail replacement leads to waste of budget. Hence, it is necessary to construct reliable actual measurement system to manage rail's life safely and efficiently, and in this study the accumulated passing tonnage measurement device is installed with using rail pad of optical fiber sensors and its effect is analyzed.

• Food Science of Animal Resources
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• v.36 no.6
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• pp.744-751
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• 2016

The objective of this study was to investigate the effects of partial beef fat replacement (0, 30, 50, 100%) with gelled emulsion (GE) prepared with olive oil on functional and quality properties of model system meat emulsion (MSME). GE consisted of inulin and gelatin as gelling agent and characteristics of gelled and model system meat emulsions were investigated. GE showed good initial stability against centrifugation forces and thermal stability at different temperatures. GE addition decreased the pH with respect to increase in GE concentration. Addition of GE increased lightness and yellowness but reduced redness compared to control samples. The results of the study showed that partial replacement of beef fat with GE could be used for improving cooking yield without negative effects on water holding capacity and emulsion stability compared to C samples when replacement level is up to 50%. The presence of GE significantly affected textural behaviors of samples (p<0.05). In conclusion, our study showed that GE have promising impacts on developing healthier meat product formulations besides improving technological characteristics.