• Geomechanics and Engineering
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• 제18권6호
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• pp.595-603
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• 2019

A modified model combining Kriging and Monte Carlo method (MC) is proposed for probabilistic estimation of tunnel face stability in this paper. In the model, a novel uniform design is adopted to train the Kriging, instead of the existing active learning function. It has advantage of avoiding addition of new training points iteratively, and greatly saves the computational time in model training. The kinematic approach of limit analysis is employed to define the deterministic computational model of face failure, in which the Hoek-Brown failure criterion is introduced to account for the nonlinear behaviors of rock mass. The trained Kriging is used as a surrogate model to perform MC with dramatic reduction of calls to actual limit state function. The parameters in Hoek-Brown failure criterion are considered as random variables in the analysis. The failure probability is estimated by direct MC to test the accuracy and efficiency of the proposed probabilistic model. The influences of uncertainty level, correlation relationship and distribution type of random variables are further discussed using the proposed approach. In summary, the probabilistic model is an accurate and economical alternative to perform probabilistic stability analysis of tunnel face excavated in spatially random Hoek- Brown media.

• 동의생리병리학회지
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• 제37권2호
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• pp.25-29
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• 2023

This study was designed to establish an atopic dermatitis (AD) model using MC903 and was conducted to find out the optimal challenge concentration that can cause dermatitis symptoms enough to be experimentally verified while reducing adverse effects such as weight loss. MC903 was treated at concentrations of 2, 3, and 4 nmol/day, and evaluation of skin surface symptoms, water contents, histopathological changes, body weight changes, and spleen/body weight ratio was conducted. In addition, the expression level of thymic stromal lymphopoietin (TSLP) was also observed. In our results, MC903 induced AD skin lesions such as erythema, scab and fissure and lowered skin moisture level significantly. In addition, water holding capacities in the 3 or 4 nmol groups were diminished significantly compared to that in the control group. On the other hand, 4 nmol treatment induced a weight loss of up to 20% compared to control group. Finally, a higher level of TSLP expression was observed in the 3 nmol group than in the 2 nmol group or the 4 nmol group. Taken together, we propose a total 14-day protocol consisting of 3 days of sensitization (2 nmol/day) and 6 days of challenge (3 nmol/day).

• Journal of Pharmaceutical Investigation
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• 제23권2호
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• pp.103-110
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• 1993

Microcapsules(Mc) of cephalexin (CEPH), using Eudragit RS, RL, L, S and polyethylene glycol 1540, were evaluated biopharmaceutically. The area under the curve of CEPH-Eudragit RS/RL Mc administered orally once was larger than that of cephalexin powder twice every 6 hrs. Controlledrelease effectiveness and the absorption rate effectiveness, two important parameters of Vallner's method, of CEPH-Eudragit RS/RL Mc indicate that these Mc can be good sustained-release preparations. And a simple pharmacokinetic model is introduced which allows the gastric emptying and intestinal-transit rates of a drug itself and a solid-state drug contained in Mc. Decreasing $K_r$, without change in $K_a$, showed that the rate-limiting step of absorption moved from absorption step to releasestep.

• Archives of Pharmacal Research
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• 제21권5호
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• pp.496-502
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• 1998

The present study was carried out to determine the possible use of cTn-I in the cardiac myofibrillar architecture, as a potential target for in vivo radioimmunodetection of cardiac damage in a brain death pig model. Radioiodiantion of the anti-cTn-I 5F4 McAb was carried out by lactoperoxidase method. the percentage iodine incorporation achieved was 70-75%. The radioiodinated McAbs were purified on Sephadex G-25 column and characterised by Paper chromatography, Phast Gel electrophoresis and electroimmunoblotting. Radioiodinated anticTn-I 5F4 McAbs were employed alongside Pyrophosphate($Tc_{99m}$-PPi$) and $Thallium^{201}$ chloride($TI^{201}$) in 24 landrace pigs (brain-dead=18 & sham-operated=6). The percentage cardiac uptake of the radiolabelled antibody injected dose was significantly higher in the brain dead animals(0.196%) as compared to that of sham-operated animals (0.11%). Specific in vivo localization of radiolabelled McAbs in the infarcted cardiac tissue was confirmed by computer-aided reconstruction of 3-D images of the isolated heart. The preliminary results of the study revealed preferential uptake of radiolabelled antibody at the site of myocyte damage resulting from artificially induced brain death.

• Journal of the Korean Wood Science and Technology
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• 제31권3호
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• pp.61-69
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• 2003

This study investigated the effect of moisture content and loading direction on dowel bearing strength of two types of SCL. Dowel bearing tests of LVL and PSL were conducted with two different MC level, 7.5% and 19%, and two different oriention, L-direction(loading parallel to grain) and X-direction(loading perpendicular to grain). Most of specimens showed typical load-deformation curves and intersected 5% offset line. Failure modes were classified into two categories; spliting(for L-direction specimens) and peeling(for X-direction specimens). Dowel bearing strength generally decreased with increasing MC. The decreasing rate was more significant in X-directon. ESG also decreased with increasing MC, and the ratio of ESG of 7.5% versus 19% was about 1.47. Dowel bearing strength of LVL and PSL in L-direction was higher than that of X-direction. This results indicated that MC and loading orientation had a significant effect on dowel bearing strength of SCL. The average dowel bearing strength of LVL were higher than that of PSL in each loading direction. Two types of probability distribution model were chosen to quantify strength distribution, normal and 2-parameter weibull distribution. The two models showed good agreement with the data, especially in lower tail of the cumulative distribution. Normal and 2-parameter weibull distribution seemed to proper model of the dowel bearing strength for each MC levels.

• Journal of the Korean Wood Science and Technology
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• 제30권3호
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• pp.59-65
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• 2002

EYM (European Yield Model), which was adopted in NDS (National Design Specification for wood construction), has been used in Korea without any verification of the analysis of bolted wood connections. In the case of applying lumber from domestic small diameter logs, however, there are some problems with the direct application of EYM ; 1) relatively low dowel bearing strength and dimensional stability due to a large amount of immature wood, 2) effect of MC (moisture contents) on the dowel bearing strength of wood and the yield load of a bolted connection. To evaluate the strength properties of bolted connections with lumber from domestic small diameter logs, effect of MC on the dowel bearing strength of wood was investigated and double shear bolted connection tests were performed. As the MC of wood increased, the dowel bearing strength was linearly reduced, even under 19% MC, which showed that adjustment, not considered in NDS, was required. Double shear bolted connection tests indicated that effect of MC on yield load should be considered in order to determine design value.

• The Journal of Asian Finance, Economics and Business
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• 제7권12호
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• pp.951-958
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• 2020

This study examines the relationship between social media marketing and brand loyalty through brand trust. Respondents were drawn from customers of McDonald's, Malang City, East Java Province, Indonesia. For this study, 130 questionnaires were distributed and data were analyzed using the Structure Equation Model (SEM) version 22 of the AMOS (Analysis of Moment Structure) application. The results showed that social media marketing had an impact on increasing McDonald's brand trust and brand loyalty. Brand trust influences brand loyalty and brand trust can mediate the influence of social media marketing on McDonald's brand loyalty. The findings prove that brand trust can mediate the effect of social media marketing on customer loyalty to McDonald's brand. These results can be explained by the fact that marketing strategies through social media marketing, such as making it easy for customers to get information related to McDonald's on social media, can contribute to customer trust and that trust is formed because McDonald's always pays attention to the quality of the products offered. Brand trust can mediate the influence of social media marketing on customer loyalty to McDonald's brand. This means that information related to McDonald's on social media is proportional to the quality of the product offered.

• 한국초전도학회:학술대회논문집
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• 한국초전도학회 1999년도 High Temperature Superconductivity Vol.IX
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• pp.233-236
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• 1999

To investigate the effect of interference current between pairs and quasi-particles, we have calculated the change I-V characteristic curve of resistively and capacitively shunted Josephson junction with external microwave by simulation of modified Stewart-McCumber model. Such rf-induced constant-voltage steps and the immunity against to noise were found to be changed in the presence of interference current.

• 지식경영연구
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• 제11권4호
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• pp.21-39
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• 2010

Recommender system is a core component of e-commerce. Correspondingly, metrics to evaluate the system performance have been developed and applied. However, even though we have lots of applications that have tried to adopt recommender systems, the dearth of successfully installed recommender systems for more than a decade leads us to a skeptical thinking that current metrics do not sufficiently indicate the recommender system success in business viability point of view. Hence, the purpose of this paper is to reconfigure measures for recommender system success. Adopting DeLone and McLean's amended model of information system success as the underlying framework, content analysis with intellectual properties on recommender systems was conducted to modify the currently used metrics. Then a model of recommender system success is proposed based on the newly identified metrics are compared with traditional metrics.

• 한국시뮬레이션학회논문지
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• 제28권3호
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• pp.49-56
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• 2019

본 논문에서는 선도이자율 모형과 리보이자율 모형 사이의 관계를 이용하여 채권 옵션의 해석적인 해(Analytic Solution; AS)와 몬테 카르로 시뮬레이션(Monte Carlo Simulation; MCS)을 이용한 가격 결정을 다룬다. AS를 이용한 채권 옵션가격 결정은 Ritchken and Sankarasubramanian (RS)의 제한 조건을 이용하여 할인된 채권 가격을 구하는 공식을 유도하고, 선도이자율과 리보이자율 모형의 변동함수 사이의 관계를 활용한다. MCS을 이용한 채권 옵션 가격 결정은 MCS을 이용하여 제시된 조건으로부터 여러 가지 예정된 전개의 시뮬레이션을 활용한다. AS와 MCS을 이용한 가격 결정 방법을 실행하여 얻은 가격을 비교하면 AS와 MCS의 상대오차(Relative Error; RE)를 구할 수 있다. 이때 본 연구의 결과로부터 RE가 약 3.9%가 됨을 확인할 수 있다. 이것은 AS뿐만 아니라 MCS을 이용해도 채권 옵션의 가격을 매우 정확하게 예측할 수 있음을 의미한다.