• Journal of Korean Public Health Nursing
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• v.19 no.1
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• pp.129-138
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• 2005

As the patients who need to undergo liver transplant operation continues to grow. the number of livers that are donated can not keep pace with the demand. With the development of surgery skills, the necessity for operations from living donors is increasing. Nevertheless, satisfactory research has been conducted on the factors which generally affect the living donors. In this article. therefore. researchers focused on the factors which generally affect the donating liver donor in order to design a plan for recommending liver donation from living donors. The subjects were 91 living liver donors in C university hospital from October 1. 2000 to December 31. 2003. The results on the uncertainty of living donor, by test sheet. were analyzed with SAS program. The final results were as follows: 1. The uncertainty of the living donors was 51.54 marks per full credit 100. 2. The factor with the greatest effect on donation was the possibility of survival of the donor, followed by the admission period. marriage status and age. In recommending the living donation, the rate of donor survival after the operation was 5.2 times higher than death, 5.2 times higher when the admission period was under 20 days. 5.0 times higher when married. and 27.3 times higher when the family-related donation was very active at the age of 20s than in the 50s. These results suggest that all medical staffs should care for living donors with more interest and activity to give them the least complaints in admission and the lowest possibilities for complication. To enhance the survival rate and improve the surgical success rate. on-going monitoring should include regular health-checks. and continual efforts and education should be made to care for the health condition of the living donors after donation.

• Geotechnical Engineering
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• v.2 no.3
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• pp.37-50
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• 1986

The uncertainties encountered in the stability analysis for the foundation of offshore structures on clay are formulated in probabilistic terms and used to evaluate the reliability of the foundation design. The major sources of uncertainty are: soil properties, f.ave loads, and methods of analysis. The major part of the uncertainty in safety factor is contributed by the uncertainty in the undrained shear strength. All sources of uncertainties that affect the shear strength of clay are modeled and systematically analyzed. The in situ undrained shear strengths are evaluated by laboratory tests and cone penetration tests. The undrained shear strengths from the laboratory test and CPT, respectively at Statfjord B site in the North Sea, are used as an example in risk analysis. Using the CPT alone, the failure probability on sliding of gravity platform at Statfjord B is much larger than the failure probability using the laboratory undrained shear strengths. The major uncertainty of using the CPT as the estimate of th2 undrained shear strength of clay results from the correlation between the cone resistance and the undrained shear strength.

• Tunnel and Underground Space
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• v.31 no.5
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• pp.360-373
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• 2021

Many sources of uncertainty exist in geotechnical analysis ranging from the material parameters to the sampling and testing techniques. The conventional deterministic stability analysis of a plane failure in rock slope produce a safety factor but not a probability of failure or reliability index. In the conventional slope stability analysis by evaluating the ground uncertainty as an overall safety factor, it is difficult to evaluate the stability of the realistic rock slope in detail. This paper reviews some established probabilistic analysis techniques, such as the MCS, FOSM, PEM, Taylor Series as applied to plane failure of rock slopes in detail. While the Monte - Carlo methods leads to the most accurate calculation of the probability of safety, this method is too time consuming. Therefore, the simplified probability methods could be alternatives to the MCS. In this study, using these simple probability methods, the failure probability estimation of a plane failure in rock slope is presented.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.33B no.2
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• pp.20-27
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• 1996

In this paper, we propose a coprime factor model reduction method to get a reduced order controller in $H^{\infty}$ mixed sensitivity problem with frequency weighting functions. for this purpose, the given $H^{\infty}$ mixed sensitivity problem is transformed into robust stabilization problem with coprime factor uncertainty of given plant. This method is to define frequency weighted coprime factors of plant in CSD (chain scattering description) form and reduce the coprime factors using weighted balanced truncation. then a controller is designed to the reduced order coprime factors using J-lossless coprime factorization method. Using this approach, the robust stability condition is derived and good performance is preserved in closed loop system with the given plant and the reduced order controller. Also the order of reduced controller for guaranteeing the robust stability can be determined before designing the reduced controller. The proposed method behaves well in both stable and unstable plant.

• Proceedings of the Korean Geotechical Society Conference
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• 2001.03a
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• pp.215-222
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• 2001

Uncertainty study of shear strength characteristics of the marine clays was carried out based ell In-situ tests and laboratory tests on tile south-east coastal region of the Korean peninsula. Theoretical analyses were studied using both tile spherical cavity expansion theory in finite soil mass and the strain path method to determine tile cone factor using the undrained shear strengths obtained by in-situ tests, and the empirical methods in accordance with the ultimate resistance theory were also discussed. Analysis show that the empirical methods suggest more reasonable value than that of theoretical methods in terms of comparing the cone factor estimated using linear regression and frequency distribution analyses. The cone factors obtained by the empirical methods are 18, 15, and 6 respectively, from the results of total cone resistance, effective cone resistance, and excess porewater cone resistance method, and the estimated were similar to those of previous researcher's.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.54 no.10
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• pp.457-464
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• 2005

Both ratio error and phase angle error in potential transformer(PT) are critically affected by used burden, connected in parallel to the secondary terminal of the PT. Thus precise measurement of burden value is very important for the evaluation of PT An automatic measurement system has been developed for the measurement of burden value and power factor of a burden. The ac voltage, current and power of the burden are measured precisely, and the burden value and power factor were calculated from these measured values. The resistance and inductance values of the tested burden are also calculated. The overall measurement uncertainties are calculated and reported with the burden value and power factor. The best measurement uncertainty for the burden measurement with the developed automatic measurement system was estimated to be 0.5 $\%$.

• Journal of the Korea Safety Management & Science
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• v.8 no.4
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• pp.63-89
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• 2006

Recently, the technology is getting to be the most important factor for companies, as the industry is changing fast. The uncertainty and complexity of technology valuation arc higher so that the technology concentrated companies need more developed and high performance technology. This paper reviews the methods of technology valuation for five categories that have been developed by valuation researchers, (1) research of technology diffusion and acceptance model, (2) research of technology valuation, (3) research of technology import and export factor, (4) research of technology valuation model, (5) research of technology transfer and market. And we propose a new technology valuation model using need(market), seed(technology) and deeds(management) factor by cross impact matrix. This model gives us the reference negotiation range for deciding the amount of royalty. I hope this paper induces more research on this field of technology valuation.

• Computational Structural Engineering : An International Journal
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• v.1 no.2
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• pp.137-137
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• 2001

The reliability/redundancy of structural system has become a serious concern among engineers and researchers after structural failures in Northridge and Kobe earthquakes. The reliability/redundancy factor, ρ, in current codes considers only member force and floor area and has received much criticism from dissatisfied engineers. Within a reliability framework. the redundancy is investigated for dual systems of primary shear walls and secondary moment frames and steel moment frame systems. Probabilistic performance analyses are carried out baled on nonlinear responses under SAC ground motion. The effects of structural configuration, ductilily capacity, 3-D motion, and uncertainty of demand verses capacity are investigated. Important redundancy-contributing factors are identified and a uniform-risk redundancy factor is developed for design. The result are compared with the p factor and its inconsistency is pointed out.

• New & Renewable Energy
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• v.7 no.4
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• pp.10-17
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• 2011

Recently, electricity industry is facing high market uncertainty which has ever had and which increase risks in power market. In this study, we analyze risk factors such as discount rates, initial investment (overnight cost), plant factor, fuel cost, carbon price, etc, for the perspective of investor. For the analysis of risk factors, we used LCOE method. The results of this study show that renewable energy is more affected by plant factor and overnight cost than other risk factors. First, Renewable energy has higher proportion of overnight cost in the total investment than that of other technologies. Second, renewable energy is free of fuel cost and carbon price so plant factor is the most important factor, in other words, competitiveness of renewable energy depends on plant factor. Furthermore, we conducted economic feasibility of wind power and PV in domestic case study. The minimum requirement condition to get profitability is that plant factor 15% and overnight cost \6,000,000/kW and 26%, \2,200,000/kW for PV and Wind Power, respectively.

• 지반과기술
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• v.3 no.3
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• pp.15-22
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• 2006

The optimum blasting pattern to excavate a quarry efficiently and economically can be determined based on the minimum production cost, which is generally estimated according to rock fragmentation. Therefore, it is a critical problem to predict fragment size distribution of blasted rocks over an entire quarry. By comparing various prediction models, it can be ascertained that the result obtained from Kuz-Ram model relatively coincides with that of field measurements. Kuz-Ram model uses the concept of rock factor to signify conditions of rock mass such as block size, rock jointing, strength and others. For the evaluation of total production cost, it is imperative to estimate 3-D spatial distribution of rock factor for the entire quarry. In this study, a sequential indicator simulation technique is adopted for estimation of spatial distribution of rock factor due to its higher reproducibility of spatial variability and distribution models than Kriging methods. Further, this can reduce the uncertainty of predictor using distribution information of sample data. The entire quarry is classified into three types of rock mass and optimum blasting pattern is proposed for each type based on 3-D spatial distribution of rock factor. In addition, plane maps of rock factor distribution for each ground level are provided to estimate production costs for each process and to make a plan for an optimum blasting pattern.