• Journal of the Korea institute for structural maintenance and inspection
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• v.10 no.3
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• pp.165-175
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• 2006

To analyze the deformation and failure of slopes, generally, two types of model, Polynomial model and Growth model, are applied. These two models are focused on the behavior of the slope by time. Therefore, this research is more focused on predicting of slope failure than analyzing the slope behavior by time. Generally, Growth model is used to analyze the soil slope, to the contrary, Polynomial model is used for rock slope. However, 3-degree polynomial($y=ax^3+bx^2+cx+d$) is suggested to combine two models in this research. The main trait of this model is having an asymptote. The fields to adopt this model are Gosujae Danyang(soil slope) and Youngduk slope(rock slope), which are the cut-slope near national road. Data from Gosujae are shown the failure traits of soil slope, to the contrary, those of Youngduk slope are shown the traits of rock slope. From the real-time monitoring data of the slope, 3-degree polynomial is proved as excellent system to analyze the failure and behavior of slope. In case of Polynomial model, even if the order of polynomials is increased, the $R^2$ value and shape of the curve-fitted graph is almost the same.

• Journal of the Society of Naval Architects of Korea
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• v.52 no.1
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• pp.52-60
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• 2015

In the present study, an evaluation method for progressive failure of composite laminates has been proposed based on Puck's failure criterion and damage mechanics. The initial failure (or initiation of crack/delamination) has been assessed using Puck's failure criterion, and the progressive failure (or growth of crack/delamination) has been evaluated using fiber- and matrix-dependent damage variables. Based on Puck's failure criterion-damage mechanics coupling theories, the ABAQUS user-defined subroutine UMAT has been developed in order to analyze the progressive failure of glass/carbon fiber-reinforced composite laminates efficiently. In addition, the developed subroutine has been applied to progressive failure problem of industrial composite laminates, and the analysis results has been compared to experimental results which have been already reported in publications. It was confirmed that the simulation results were coincided well with the reported composite failure results.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.28 no.9
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• pp.1337-1343
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• 2004

Shape optimization was performed to obtain a precise shape of cutouts including the internal shape of cutouts in a laminated composite plate by three dimensional modeling using solid element. Volume control of the growth-strain method was implemented and the distributed parameter chosen as Tsai-Hill fracture index for shape optimization. It makes Tsai-Hill failure index at each element uniform in laminated composites under the predetermined volume a designer requires. Shapes optimized by Tsai-Hill failure index were compared with those of the initial shapes for the various load conditions and cutouts. The following conclusions were obtained in this study; (1) It was found that growth-strain method was applied efficiently to shape optimization of three dimensional cutouts in a laminate composite, (2) The optimal shapes of the various load conditions and cutouts were obtained, (3) The maximum Tsai-Hill failure indices of the optimal shapes were remarkably reduced comparing with those of the initial shapes.

• Journal of the Korean Society for Railway
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• v.9 no.5 s.36
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• pp.606-611
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• 2006

This paper presents a procedure and an analysis method to evaluate reliability of the Korea high-speed train. The rolling stock system is divided into 6 sub-systems and each subsystem is classified into sub-assemblies. Functional analysis has been conducted to draw reliability block diagrams for the sub-systems. First, failure rates has been calculated for each sub-assembly from the failure data obtained during commissioning tests. Then a reliability block diagram is used to evaluate the MKBF(Mean Kilometers Before Failure) of the sub-systems. Activities to increase reliability have been carried out throughout the test runs and analysis results show that the reliability of the rolling stock system is gradually growing in time.

• The Journal of Korean Physical Therapy
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• v.11 no.3
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• pp.133-140
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• 1999

Why does the CNS not regenerate after injury? The failure of axonal regeneration in the CNS after injury is not due to an inherent inability of these neurons to regrowth axon. Recently, an inhibitory substrate effect of CNS has been discovered which could be directly invoked in the lack of regeneration. The failure of axon regrowth in the CNS is crucially influenced by the presence of neurtie growth inhibitor NI35/250 and possibly also by molecules such as myelin associated glycoprotein(MAG) and chondroitin sulphate proteoglycans(CSPGs). The application of the monoclonal antibody IN-1, which efficinetly neutralizes the N135/250 inhibitory molecules. This new finding has a strong impact on the development of, a new neuroscienctific research directed to stimulate axonal regeneration. In this review summarize the current knowledge on the factors and molecules involved in the regeneration failure.

• Journal of Korea Technology Innovation Society
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• v.8 no.3
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• pp.1175-1198
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• 2005

The objective of the study is to verify the relationship between technology valuation indexes and corporate's performance in ventures by business operating periods. The result of the study is expected to be useful in loan evaluation, investment decision, internal management decision making and business improvement. The results of study is as follows. First, in early stage ventures, we find that three major valuation index(technology feasibility, economic efficiency, productivity) are significant ex-ante variables which are discriminating between firms' going concern and firms' failure. Second, in growth stage ventures, we find that three major valuation index(business feasibility, general marketability, technology marketability) are significant ex-ante variables which are discriminating between firms' going concern and firms' failure. Third, in early stage ventures, we find that at least thirty-eight minor valuation index elements are significant ex-ante variables which are discriminating between firms' going concern and firms' failure and in growth stage ventures, thirty-one minor valuation index elements are significant in various analysis' results.

• Journal of the Korean Data and Information Science Society
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• v.19 no.4
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• pp.1361-1369
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• 2008

The analysis of software reliability model provides the means to analysts, software engineers, and systems analysts and developers who want to predict, estimate, and measure failure rate of occurrences in software. In this paper, reliability growth model, in which the operating time between successive failure is a continuous random variable, is proposed. This model is based on order statistics of two parameters Burr type XII distribution. We propose the measure based on U-plot. Also the performance of the suggested model is tested on real data set.

• Journal of the Korean Society of Safety
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• v.29 no.3
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• pp.136-142
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• 2014

Recently a new version of PRO-LOCA program was released. Using the program, failure probability of pipes can be evaluated considering fatigue and/or stress corrosion crack growth and the effects of various parameters on the integrity of pipes in nuclear power plants can be evaluated quantitatively. The analysis results can be used to establish an inspection plan and to examine the effects of important parameters in a maintenance plan. In this study, sensitivity analyses were performed using the program for several important parameters including sampling method, initial crack size, number of initial fabrication flaws, operation temperature, inspection interval, operation temperature and nominal applied bending stress. The effect of parameters on the leak and rupture probability of pipes was evaluated due to fatigue or stress corrosion crack growth.

• Proceedings of the KSR Conference
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• 2004.06a
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• pp.702-709
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• 2004

Modified Gurson model (Gurson-Tvergaard-Needleman model) was used to analyze crack growth in M(T) and C(T) specimens. A commercial finite element code ABAQUS/Explicit is used to account for total failure of material point by cavity coalescence, and crack growth was simulated by finite element extinction. Crack growth resistance curve was obtained by calculating J-integral. Crack growth under residual stress was investigated.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.3 no.1
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• pp.68-74
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• 2000

Purpose: This study was to investigate the clinical manifestations of FTT in children. Methods: From March 1997 to July 1999, clinical observations were made on patients with FTT who had visited to Samsung Medical Center. Detailed histories and through physical examinations were taken, and when suspected organic FTT, basic laboratory studies were done. Results: Upon the review of medical records, we investigated the clinical manifestations of 74 children, aged 1 month and 13 year 1 month. The causes of FTT were composed of either physiologic (47.8%) or pathologic (52.2%) ones. Among the physiologic FTT, were there familial short stature (FSS, 14.5%), intrauterine growth retardation (IUGR, 14.5%), constitutional growth delay (CGD, 11.6%), idiosyncrasy and prematurity. Among pathologic causes, neurologic disorders (20%) are the most common causes of FTT, and then follow by GI (13.4%), allergic and infectious disorders in decreasing order. The data showed that average caloric intake in patients with FTT was 76,2% of recommended amount. FTT patients with CGD, IUGR, and idiosyncrasy had tendency to take small foods. The FTT children with prematurity, IUGR and pathologic FTT, were short and thin for their ages. However FTT children with CGD and FSS had tendency to be thin with relatively normal heights for their ages, in comparison with those of the children with prematurity, IUGR and pathologic FTT. Conclusion: The diagnosis of FTT was easily obtained with simple and through medical history, physical examination, and minimal laboratory tests. In this study, organic FTT was more prevalent than physiologic one. This results indicate that early intervention is mandatory, because children may develop significant long-term sequelae from nutritional deficiency.