• Journal of Radiation Protection and Research
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• v.41 no.4
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• pp.344-349
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• 2016

Background: Carbon ion therapy has achieved satisfactory results. However, patients have a risk to get a secondary cancer. In order to estimate the risk, it is essential to understand particle transportation and nuclear reactions in the patient's body. The particle transport Monte Carlo simulation code is a useful tool to understand them. Since the code validation for heavy ion incident reactions is not enough, the experimental data of the elementary reaction processes are needed. Materials and Methods: We measured neutron production double-differential cross-sections (DDXs) on a carbon bombarded with 430 MeV/nucleon carbon beam at PH2 beam line of HIMAC facility in NIRS. Neutrons produced in the target were measured with NE213 liquid organic scintillators located at six angles of 15, 30, 45, 60, 75, and $90^{\circ}$. Results and Discussion: Neutron production double-differential cross-sections for carbon bombarded with 430 MeV/nucleon carbon ions were measured by the time-of-flight method with NE213 liquid organic scintillators at six angles of 15, 30, 45, 60, 75, and $90^{\circ}$. The cross sections were obtained from 1 MeV to several hundred MeV. The experimental data were compared with calculated results obtained by Monte Carlo simulation codes PHITS, Geant4, and FLUKA. Conclusion: PHITS was able to reproduce neutron production for elementary processes of carbon-carbon reaction precisely the best of three codes.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.35 no.1
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• pp.9-14
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• 2022

In this study, a smart jack-up system was developed to prevent safety accidents by performing risk analysis when a structure is lifted for maintenance. A quantitative risk analysis program that can analyze the risk using the pairwise comparison matrix analysis method was developed. The risk was analyzed in real-time for the lifting structure by connecting the program with an automatic jack-up system. Displacements were measured by the IR sensor among the components of the automatic jack-up system, and the displacements were provided to the quantitative risk analysis program. To confirm the performance of the smart automatic jack-up system, experiments were conducted on bridge and risk analysis was performed when a superstructure was lifted. A linear variable differential transformer (LVDT) was also installed on the bridge to verify the performance of the smart automatic jack-up system. The maximum displacements were measured using the devices, and the declinations were compared. The performance of the simultaneous operation of the jack-up device was verified by the analysis of variance (ANOVA).

• The Journal of Asian Finance, Economics and Business
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• v.6 no.1
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• pp.83-89
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• 2019

The purpose of this paper is to examine how the social system of deposit insurance affected the financial market in Korea. Specifically, we want to know how much the risk-seeking behavior of financial institutions has increased or decreased. The most important feature of the deposit insurance system is to prevent the insolvency of financial institutions and to properly protect depositors. In recent studies, it has been argued that characteristics of deposit insurance bring moral hazard of financial institutions and that financial institutions make unreasonably risky investments. Therefore, in this study, we will first examine whether such previous research can be applied to the Korean financial market. Next, we will examine the appropriateness of the differential premium rate that is currently used for each financial institution in the Korean financial market. In order to test the first hypothesis, we used the Capital Asset Pricing Model (CAPM) to calculate the total risk for each financial institution. As a result, significant changes were found in all regions before and after the introduction of the deposit insurance system. As for testing the second hypothesis, we conducted a variance analysis of financial institutions' indexes before and after the introduction of the deposit insurance and we discovered significance of the total risk difference.

• Journal of Korea Water Resources Association
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• v.38 no.12 s.161
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• pp.1021-1028
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• 2005

This study purpose to develop simulation model of optimal design condition of urban storm sewer system considering risk. Urban Storm Sewer Optimal Design Model(USSOD) can compute pipe capacity, pipe slope, crown elevation, excavation depth, risk and return cost in the condition of design discharge. Rational formula is adopted for design discharge and Manning's formula is used for pipe capacity. Discrete differential dynamic programming(DDDP) technique which is a kind of dynamic programming(DP) is used for optimization and first order second moment approximation method and uncertainty analysis is also for developing model. USSOD is applied to hypothetical drainage basin to test and verify, which resulted economical and efficient design in urban drainage sewer system.

• Journal of Acupuncture Research
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• v.24 no.1
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• pp.137-159
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• 2007

Objectives: The purpose of this study is to examine the risk factors and the genetic polymorphism of TNF-alpha associated with rheumatoid arthritis by Sasang constitution Methods : This study was planned to detect the susceptibility of the patients diagnosed by rheumatoid arthritis to Sasang Constitution and to examine the risk factor such as life style and environmental stress (smoking, environmental tobacco smoke, alcohol intake and so on). The genetic polymorphism of TNF-alpha (G308A) were analyzed by PCR-RFLP in rheumatoid arthritis patients and controls. Rheumatoid arthritis patients and matched controls are assessed with QSCCII question for Sasang Typology. Then the genetic polymorphism of patients by Sasang constitution are compared to those of control, which are statistically analyzed and adjusted by age, sex, smoking status, alcohol intake, BMI, and econocmic status. Results: Differential effect of passive smoking on the association between Sasang constitution and rheumatoid arthritis risk was found. This study showed that the genetic polymorphism (TNF-${\alpha}$(G308A)) of rheumatoid arthritis patients and controls associated with the susceptibility to rheumatoid arthritis by sasang constitution was analyzed. Differential effects of TNF-${\alpha}$(G308) genetic polymorphism on the association between rheumatoid arthritis risk and Sasang constitution were found. Conclusion : It is suggested that the genetic polymorphism correlated with susceptibility to rheumatoid arthritis by specific sasang constitution used as its susceptibility marker and further as basic data to prevent the risk factors for rheumatoid arthritis. But larger studies will be needed to confirm these preliminary findings.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.1
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• pp.69-85
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• 2019

BeiDou navigation satellite system (BDS) is one of the four main types of global navigation satellite systems. The current system has been widely used by the military and by the aerospace, transportation, and marine fields, among others. However, challenges still remain in the BeiDou system, which requires rapid responses for delay-sensitive devices. A differential positioning algorithm called the data center-based differential positioning (DCDP) method is widely used to avoid the influence of errors. In this method, the positioning information of multiple base stations is uploaded to the data center, and the positioning errors are calculated uniformly by the data center based on the minimum variance or a weighted average algorithm. However, the DCDP method has high delay and overload risk. To solve these problems, this paper introduces edge computing to relieve pressure on the data center. Instead of transmitting the positioning information to the data center, a novel method called edge computing-based differential positioning (ECDP) chooses the nearest reference station to perform edge computing and transmits the difference value to the mobile receiver directly. Simulation results and experiments demonstrate that the performance of the ECDP outperforms that of the DCDP method. The delay of the ECDP method is about 500ms less than that of the DCDP method. Moreover, in the range of allowable burst error, the median of the positioning accuracy of the ECDP method is 0.7923m while that of the DCDP method is 0.8028m.

• Journal of the Korean Geosynthetics Society
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• v.22 no.1
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• pp.87-96
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• 2023

There are a lot of difference between the surface settlement and the differential settlement measured at the Busan New Port, where the dredged and reclaimed clay layer exists and below the clay is originally thickly distributed. To find the cause and solution of this, the actual conditions of each differential settlement used for the soft ground improvement, characteristics, installation method, measurement frequency, measurement data management, and data analysis of each type were considered. In the deep soft ground improvement work where large deformation occurs, the bending deformation of the screw-type differential settlement gauge is less than that of other types of measuring instruments, so there is less risk of loss, and the reliability of data is relatively high as the instruments are installed by drilling for each stratum. Since the greater the amount of high-precision settlement measurement data, the higher the settlement analysis precision. It is necessary to manage with higher criteria than the measurement frequency suggested in the standard specification. For the data management of the differential settlement gauge, it is desirable to create graphs of the settlement and embankment height of the relevant section over time, such as surface, differential, and settlement of pore water pressure gauge for each point. In the case of multi-layered ground with different compression characteristics, it is more appropriate to perform settlement analysis by calculating the consolidation characteristics of each stratum using a differential settlement data.

• Journal of the Korean Data and Information Science Society
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• v.26 no.2
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• pp.323-334
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• 2015

he current VaR model based on the J.P. Morgan's RiskMetrics structurally can not reflect the future economic situation. In this study, we propose a One-factor model resulting from the Wiener stochastic process decomposed into a systematic risk factor and an idiosyncratic risk factor. Therefore, we are able to perform a preemptive risk management by means of reflecting the predicted common risk factors in the model. Stocks in the portfolio are satisfied with the independence to each other because the common factors are fixed by the predicted value. Therefore, we can easily determine the investment in each stock to minimize the variance of the portfolio. In addition, the portfolio VaR is decomposed into the sum of the individual VaR. So we can effectively implement the constitution of the portfolio to meet the target maximum losses.

• The Journal of the Korean dental association
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• v.50 no.12
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• pp.732-742
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• 2012

White lesions of the oral mucosa are a common clinical finding that often present first to general dentist. Some white lesion may have possibility of malignancy. Leukoplakia is the most common "potentially malignant disorder" of the oral mucosa. Leukoplakia is at present defined as "A white plaque of questionable risk having excluded (other) known disease or disorders that carry no increased risk for cancer.". Therefore, it is important for general dentist to be familiar to clinical differential diagnosis of leukoplakia from the known white lesions such as candidiasis, lichen planus, leukoedema, frictional keratosis, and so on. It is also important to decide whether such lesions require further investigation through the biopsy. As a result of biopsy, the presence of epithelial dysplasia in the leukoplakia is still the strongest predictor of future malignant transformation. In this article, oral white lesions that must be differentiated from potentially malignant disorders or early invasive squamous cell carcinoma will be reviewed together with presenting clinical cases.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2011.11a
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• pp.175-176
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• 2011

Applying previous studies performed in the moisture transportation characteristics and shrinkage of lightweight concrete application of shrinkage reduction is to discuss. Applicability of shrinkage reduction effect of lightweight concrete applies for the analysis of PSC girder bridge beam placed on the construction site. Stress of the concrete bridge deck, rebar quantity is calculated by effective elastic modulus method and crack risk is assessed by moisture transport and differential shrinkage analysis. After approximately 10 days maximum tensile stress occurs 6MPa, similar to the case of normal concrete, a maximum tensile stress occurs 3MPa in lightweight concrete and comparing to normal concrete stress was reduced to approximately 50%. Normal and lightweight concrete crack index, respectively, is reduced 1.6 to 1.2, 1.2 to 0.9 in surface and boundary region. Therefore, reduction in shrinkage of concrete were able to confirm reduction of crack risk.