• Tunnel and Underground Space
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• v.13 no.2
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• pp.77-86
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• 2003

The finite element method and statistics of the convergence measurement are useful method of the stability analysis of the tunnel adjacent to the pier. It is the purpose of the this case study to certificate of validity of the application of those methods. The safety of the pilot tunnel method and LW pre-grouting has been evaluated from the FEM analysis. The three-dimensional finite element method is carried out for the decision of the level of stress redistribution at the two-dimensional numerical analysis. An analysis of the convergence is carried out by the estimation of preceding convergence at tunnel excavation. F-examination is applied for this estimation. As results of that analysis, The F-value is from 10.81 to 158.74 and the coefficient of determination is from 0.82 to 0.99. An analysis of convergence is carried out by using regression analysis. Consequently, it is shown that the convergence can be modeled as following function C(t)=a[1-exp(-bt)].

• Tunnel and Underground Space
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• v.29 no.6
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• pp.523-531
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• 2019

In the applications of rock mechanics or rock engineering including drill and blast, drilling and mechanical excavation, the fracture toughness is an important factor. Several methods have been proposed to measure the fracture toughness of rocks. In this study, wedge splitting test specimen which is prepared with ease and tested under compression loading was used to obtain mode I fracture toughness of rocks. The equation of stress intensity factor through numerical analysis is proposed from the stress state of crack tip considering both vertical and horizontal loads due to the vertical load acting on the wedge. The validity of the wedge splitting test method was confirmed by comparing the mode I fracture toughness values obtained by the GD and SENB test specimens.

• Communications for Statistical Applications and Methods
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• v.18 no.6
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• pp.741-750
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• 2011

In this paper, we derive an software mixed debugging model based on a Markov process, assuming that the length of time to perform the debugging is random and its distribution may depend on the fault type causing the failure. We assume that the debugging process starts as soon as a software failure occurs, and either a perfect debugging or an imperfect debugging is performed upon each fault type. One type is caused by a fault that is easily corrected and in this case, the perfect debugging process is performed. An Imperfect debugging process is performed to fix the failure caused by a fault that is difficult to correct. Distribution of the first passage time and working probability of the software system are obtained; in addition, an availability function of a software system which is the probability that the software is in working at a given time, is derived. Numerical examples are provided for illustrative purposes.

• Journal of Korean Society of Steel Construction
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• v.12 no.2 s.45
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• pp.187-196
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• 2000

In this paper, stability analysis is carried out for the out of plane behaviors under compressive loads to the direction of the generator in anisotropic cylindrical shells. It is not easy to obtain the analytic solutions about the stability analysis of anisotropic cylindrical shells consisted of composite materials. For solving this problems, this paper used the finite difference method which is one of the numerical methods. Geometrical property of cylindrical shells transforms the compressive loads into the inplane behaviors. This paper studied the change of stiffness in the direction of the circumferential and stability of shells according to change of fiber angle, curvature, subtended angle and aspect ratio. From result of this study, anisotropic cylindrical shells under compressive loads to the direction of the generator vary greatly with respect to the change of the circumferential stiffness. Therefore, it will be more safe to strengthen the circumferential stiffness of anisotropic cylindrical shells under compressive loads.

• The Journal of Internal Korean Medicine
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• v.38 no.5
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• pp.769-777
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• 2017

Objective: Facial nerve palsy is caused by damage to the 7th cranial nerve. It is the main symptom of facial muscle paralysis on the affected side. Usually, recovery from this disease begins 2-3 weeks after onset and most patients recover in 4-8 weeks. If the patients cannot receive proper treatment, severe permanent impairments, both physical and mental, may remain, so this disease should be treated appropriately. In this study, a patient with facial nerve palsy was admitted to the Korean medicine hospital for treatment. We report on the patient's progress and the effects of treatment. Methods: We cured the patient with herbal medicines, acupuncture, herbal acupuncture therapy, and physical therapy. We used a numerical rating scale, the House Brackmann grading system, and a weighted regional grading system to assess symptom changes. Result: The patient with facial nerve palsy was hospitalized for 23 days and recovered from symptoms without significant problems on the face or in motor function.

• The Journal of Internal Korean Medicine
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• v.38 no.5
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• pp.797-805
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• 2017

Objectives: The purpose of this clinical case is to evaluate the efficacy of traditional Korean medicine as a treatment for fibromyalgia. Methods: The patient was treated with Korean medicine therapy (herbal medicine, acupuncture, pharmacopuncture, and Chu-na therapy). We measured the status and progress of this patient using a numerical rating scale (NRS), EuroQol-5D, range of movement (ROM), and a special test. Results: After the treatments, the patient's pain was controlled and the NRS score decreased. The overall symptoms of the patient and the EQ-5D score were both improved. The ROM and special test score were also improved. Conclusions: Traditional Korean medicine may have positive effects as a treatment for fibromyalgia.

• The Journal of Internal Korean Medicine
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• v.39 no.5
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• pp.1023-1031
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• 2018

Objectives: The purpose of this study is to evaluate the effect of Korean medicine in a patient with sensory disturbance of the hands and feet diagnosed as hereditary motor and sensory neuropathy (Charcot-Marie-Tooth disease). Methods: A patient diagnosed with hereditary motor and sensory neuropathy (Charcot-Marie-Tooth disease) was treated with herbal medicine (Uchashinki-hwan-gami, Bosinji Granule, Ukgan-san-gami), acupuncture, moxibustion, and bee venom pharmacopuncture. Clinical improvements were evaluated using the numerical rating scale (NRS) and Toronto Clinical Neuropathy Score system (TCNSS). Results: Improvements in the total scores of NRS and TCNS were observed after Korean medicine treatments. NRS score decrease from 8 to 2, and TCNS score decreased from 10 to 7. Conclusion: Korean medicine treatment may be effective for sensory disturbance in hereditary motor and sensory neuropathy (Charcot-Marie-Tooth disease).

• The Journal of Korean Institute of Communications and Information Sciences
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• v.17 no.12
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• pp.1343-1352
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• 1992

This paper presents a new and easy method to obtain the Fourier transforms of the n-th order cosine-pulses whose maximum amplitudes are uniform. The new method is focused on deriving a formula which is recursively related following their orders and can be well applied to some numerical solutions. On the other hand, this method also offers more compact procedures in view of analytical solutions than the conventional methods because the results are consist of the sum of two functions which are easily calculated. Especially, the formula can be represented as a complete recursion by the separation of coefficients originated by the authors and the resulting difference equation is given by the sum of the original 'sinc' functions shifted by some symmetrical factors and multiplied by some constants. The constants are easily decided from the binomial coefficients and the shifting factors from the corresponding exponential differences in the expansion of $(a+b)^n$.

• Tunnel and Underground Space
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• v.23 no.2
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• pp.99-109
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• 2013

The slopes of open-pit mine are typically designed without considering the reinforcement and support method due to the economical efficiency. However, the long-term stability of final pit slope is needed in some case, therefore the appropriate measures that can improve the stability are required. In this study, the field survey and laboratory test were carried out in S limestone mine. The stability assessment of final pit slope was performed through the stereographic projection method, SMR, and numerical analysis. And countermeasures for stabilization were proposed. The results of analysis show that full scale of slope failure is not expected but the failures of bench slope scale are likely to occur. In oder to increase the stability of bench slope, we suggested the remedial methods as follows: excavating the final pit slope by pre-splitting blasting, placing the wide berm in the intermediate bench slope and installing the horizontal drainage hole in the place of local ground water runoff.

• The Korean Journal of Applied Statistics
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• v.29 no.5
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• pp.807-822
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• 2016

The composite lognormal-GPD models (LN-GPD) enjoys both merits from log-normality for the body of distribution and GPD for the thick tailedness of the observation. However, in the estimation perspective, LN-GPD model performs poorly due to numerical instability. Therefore, a two-stage procedure, that estimates threshold first then estimates other parameters later, is a natural method to consider. This paper considers five nonparametric threshold estimation methods widely used in extreme value theory and compares their performance in LN-GPD parameter estimation. A simulation study reveals that simultaneous maximum likelihood estimation performs good in threshold estimation, but very poor in tail index estimation. However, the nonparametric method performs good in tail index estimation, but introduced bias in threshold estimation. Our method is illustrated to the service time of an Israel bank call center and shows that the LN-GPD model fits better than LN or GPD model alone.