• Computers and Concrete
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• v.32 no.5
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• pp.499-511
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• 2023

Anchor channels are commonly used for façade, tunnel, and structural connections. These connections encounter various types of loadings during their service life, including high rate or impact loading. For anchor channels that are placed close and parallel to an edge and loaded in shear perpendicular to and towards the edge, the failure is often governed by concrete edge breakout. This study investigates the transverse shear behavior of the anchor channels under quasi-static and high rate loadings using a numerical approach (3D finite element analysis) utilizing a rate-sensitive microplane model for concrete as constitutive law. Following the validation of the numerical model against a test performed under quasi-static loading, the rate-sensitive static, and rate-sensitive dynamic analyses are performed for various displacement loading rates varying from moderately high to impact. The increment in resistance due to the high loading rate is evaluated using the dynamic increase factor (DIF). Furthermore, it is shown that the failure mode of the anchor channel changes from global concrete edge failure to local concrete crushing due to the activation of structural inertia at high displacement loading rates. The research outcomes could be valuable for application in various types of connection systems where a high rate of loading is expected.

• Journal of Digital Convergence
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• v.11 no.8
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• pp.143-157
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• 2013

The purpose of this study is firstly, to find out the factors of entrepreneurial intention in potential entrepreneurs, and secondly to examine the relationship between objective start-up environment and subjective recognition of start-up environment, and entrepreneurial intention. For this study, investigation has been done to find out if fear of business failure, that is notoriously high among Koreans, acts as an influential factor between objective start-up environment/subjective recognition of start-up environment and entrepreneurial intention. The data is collected from 335 respondents comprised of college students and adults who are interested in starting their own businesses. The results of this study are as follows : (1) Objective start-up environment and subjective recognition of start-up environment, which is self-efficacy, have a positive effect on entrepreneurial intention. (2) Fear of business failure mediates the relationship between objective start-up environment/subjective recognition of start-up environment, and entrepreneurial intention (3) Child-care system, as an explain variable in the objective start-up environment in this study, is an important factor in the process of entrepreneurial commitment.

• Journal of Applied Reliability
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• v.18 no.3
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• pp.193-200
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• 2018

Purpose: In this study, the life of the motor is investigated by performing the accelerated life test with the brush wear of the industrial cleaner motor as the main failure mode. Methods: The accelerating stress factor of the accelerated life test is a voltage, which can increase the number of revolutions of the motor to accelerate the brush wear due to the friction between the brush and the commutator. Also, the accelerating stress level was determined after determining the maximum allowable level of the voltage through the preliminary test. Results: The motor failure time at each accelerating stress level was predicted by regression analysis with brush wear length as performance degradation data. The main failure mode, which is brush wear, of the motor was reproduced by this test. The shape parameter of the Weibull distribution was confirmed to be the same statistically at all accelerating stress levels by the likelihood ratio test. Conclusion: The life of the motor was investigated by performing the accelerated life test with the brush wear of the industrial cleaner motor as the main failure mode. Through the accelerating test method of the cleaner motor, various life expectancy and life expectancy of the acceleration factor are predicted.

• Journal of Korean Library and Information Science Society
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• v.22
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• pp.139-169
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• 1995

The purpose of this study is to analyze the search pattern and search outcome of the National Central Library OPAC users by measuring their success rates and identifying the factors of failure and the personal background which bring about the differences of the search outcome. Various methods have been used for the study. Personal interview was used to find the pattern of the search, observation method was used to investigate the search process and the failure factors, and a questionnaire was used to survey personal background of searchers. The data were collected during the period of 7 days from April 17, 1995 through April 23, 1995. The search of 1, 217 cases, sampling systematically 25% out of the whole users, were collected and analyzed for the study. The findings of the study can be summarized as follows : First, in regard to the pattern, known-item search(72.6%) was preferred to the subject search(27.4%) and in case of known-item search the access point used were in the order of title, author, title and author. Second, the overall success rate of known-item search was 50.3% and the success rates were in order of author and date, title, and author. The failure factors of known-item search were divided into users factor of 67% and the database factor of 33%, respectively. Third, in case of subject search, its overall success rate was 44.1% and the keyword was the major access point, and the average of precision ratio was very low. Fourth, the analysis of the personal background related to the search outcome has shown significant differences by sex, the experience of using OPAC, education level, and the frequency of using other information retrieval systems. Based on the results the following suggestions can be made to improve the search outcome : First, the system should be su n.0, pplemented online help function to assist users to overcome the failure during search. Second, user instruction in group or individual should be implemented for the users to understand the system.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.10
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• pp.5699-5703
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• 2013

Objective: To investigate the clinical effects of whole brain radiotherapy concomitant with targeted therapy for brain metastasis in non-small cell lung cancer (NSCLC) patients with chemotherapy failure. Materials and Methods: Of the 157 NSCLC patients with chemotherapy failure followed by brain metastasis admitted in our hospital from January 2009 to August 2012, the combination group (65 cases) were treated with EGFR-TKI combined with whole brain radiotherapy while the radiotherapy group (92 cases) were given whole brain radiotherapy only. Short-term effects were evaluated based on the increased MRI in brain 1 month after whole brain radiotherapy. Intracranial hypertension responses, hematological toxicity reactions and clinical effects of both groups were observed. Results: There were more adverse reactions in the combination group than in radiotherapy group, but no significant differences were observed between the two groups in response rate (RR) and disease control rate (DCR) (P>0.05). Medium progression free survival (PFS), medium overall survival (OS) and 1-year survival rate in combination group were 6.0 months, 10.6 months and 42.3%, while in the radiotherapy group they were 3.4 months, 7.7 months and 28.0%, respectively, which indicated that there were significant differences in PFS and OS between the two groups (P<0.05). Additionally, RPA grading of each factor in the combination group was a risk factor closely related with survival, with medium PFS in EGFR and KRAS mutation patients being 8.2 months and 11.2 months, and OS being 3.6 months and 6.3 months, respectively. Conclusions: Whole brain radiotherapy concomitant with target therapy is favorable for adverse reaction tolerance and clinical effects, being superior in treating brain metastasis in NSCLC patients with chemotherapy failure and thus deserves to be widely applied in the clinic.

• Economic and Environmental Geology
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• v.33 no.4
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• pp.295-307
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• 2000

Probabilistic analysis is a powerful method to quantify variability and uncertainty common in engineering geology fields. In rock slope engineering, the uncertainty and variation may be in the form of scatter in orientations and geometries of discontinuities, and also test results. However, in the deterministic analysis, the factor of safety which is used to ensure stability of rock slopes, is based on the fixed representative values for each parameter without a consideration of the scattering in data. For comparison, in the probabilistic analysis, these discontinuity parameters are considered as random variables, and therefore, the reliability and probability theories are utilized to evaluate the possibility of slope failure. Therefore, in the probabilistic analysis, the factor of safety is considered as a random variable and replaced by the probability of failure to measure the level of slope stability. In this study, the stochastic properties of discontinuity parameters are evaluated and the stability of rock slope is analyzed based on the random properties of discontinuity parameters. Then, the results between the deterministic analysis and the probabilistic analysis are compared and the differences between the two analysis methods are explained.

• Journal of the Korean Geotechnical Society
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• v.30 no.11
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• pp.5-15
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• 2014

It is very important to design and construct slopes safely because damage cases are increasing due to slope failure. Recently, Limit Equilibrium Method (LEM) based programs are commonly used for slope designs. Though LEM can give factors of safety through simple calculation, it has a disadvantage that the sliding surface should be assumed in advance. On the other hand, the use of Finite Difference Method (FDM) is increasing since the factor of safety can be easily estimated by using shear strength reduction technique. Therefore the purpose of this study is to present a reasonable slope design methodology by comparing the two commonly used analysis approaches; LEM and FDM. To this end, the reinforcement effects of the two methods were compared in terms of the support pattern of soil nailing reinforced in the section where plane failure is anticipated. As a result, the reinforcement effects by nail angle and nail spacing turned out to be equal. Also it was found that the factor of safety increased in LEM, but not changed in FDM when the nail length increased.

• Journal of the Korea Society of Computer and Information
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• v.25 no.6
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• pp.199-206
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• 2020

This study was conducted for the purpose of developing a measurement tool for success and failure factors of education and training of Korean bodyguards. conducted a meeting from the fully open questionnaire at first, and then formed the semi-structured questionnaire, finally carried out the survey from the closed questionnaire and analyzed data from SPSS 21.0, AMOS 21.0 and developed the measurements. It was conducted from May, 2019 to December, 2019. This survey was conducted of 150 security guards after the verification of the content validity though the pilot survey and presented the success attribution factors and standards on the basis of the result form this survey. As a result, the success factors of the training of the bodyguards were accidental education (5 item), vocational mental education (2 item), vocational mental education (2 item), work ability enhancement education (2 item), realistic practical education (2 item) ), Including 4 items, 11 items, The failure factors consisted of 12 item of three factors: formal education and training (5 item), lack of leadership qualities (4 item), and lack of education (3 item).

• KSCE Journal of Civil and Environmental Engineering Research
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• v.4 no.3
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• pp.75-83
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• 1984

The probability of failure is used to analyze the reliability of three dimensional slope failure, instead of conventional factor of safety. The strength parameters are assumed to be normal variated and beta variated. These are interval estimated under the specified confidence level and maximum likelihood estimation. The pseudonormal and beta random variables are generated using the uniform probability transformation method according to central limit theorem and rejection method. By means of a Monte-Carlo Simulation, the probability of failure is defined as; $P_f=M/N$ N: Total number of trials M: Total number of failures Some of the conclusions derived. from the case study include; 1. Three dimensional factors of safety are generally much higher than 2-D factors of safety. However situations appear to exist where the 3-D factor of safety can be lower than the 2-D factor of safety. 2. The $F_3/F_2$ ratio appears to be quite sensitive to c and ${\phi}$ and to the shape of the 3-D shear surface and the slope but not to be to the unit weight of soil. 3. From the two models (normal, beta) considered for the distribution of the factor of safety, the beta distribution generally provides lager than normal distribution. 4. Results obtained using the beta and normal models are presented in a nomgraph relating slope height and slop angle to probability of failure.

• Journal of Korean Tunnelling and Underground Space Association
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• v.21 no.5
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• pp.621-640
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• 2019

Quantitative stability assessment of underground cavities can be presented as a factor of safety based on the Shear Strength Reduction Method (SSRM). Also, SSRM is one of the stability evaluation methods commonly used in slope stability analysis. However, there is a lack of research that considers the relationship between the probability of occurrence of cavities in the ground and the potential failure surface of the slope at the same time. In this study, the effect of small underground cavities on the failure behavior of the slope was analyzed by using SSRM. Considering some of the glaciology studies, there is a case that suggests that there is a cavity effect inside the glacier in the condition that the glacier slides. In this study, the stability evaluation of underground cavities and slope stability analysis, where SSRM is used in geotechnical engineering field, was carried out considering simultaneous conditions. The slope stability analysis according to the shape and position change of underground cavities which are likely to occur in the lower part of a mountain road was analyzed by using SSRM in FLAC3D software and the influence of underground cavities on the slope factor of safety was confirmed. If there are underground cavities near slope potential failure surface, it will affect the calculation of a factor of safety. The results of this study are expected to be basic data on slope stability analysis with small underground cavities.