• Earthquakes and Structures
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• v.7 no.2
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• pp.201-216
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• 2014

In this paper the vulnerability of the confined masonry buildings is evaluated analytically. The proposed approach includes the nonlinear dynamic analysis of the two-story confined masonry buildings with common plan as a reference structure. In this approach the damage level is calculated based on the probability of exceedance of loss vs a specified ground motion in the form of fragility curves. The fragility curves of confined masonry wall buildings are presented in two levels of limit states corresponding to elastic and maximum strength versus PGA based on analytical method. In this regard the randomness of parameters indicating the characteristics of the building structure as well as ground motion is considered as likely uncertainties. In order to develop the analytical fragility curves the proposed analytical models of confined masonry walls in a previous investigation of the authors, are used to specify the damage indices and responses of the structure. In order to obtain damage indices a series of pushover analyses are performed, and to identify the seismic demand a series of nonlinear dynamic analysis are conducted. Finally by considering various mechanical and geometric parameters of masonry walls and numerous accelerograms, the fragility curves with assuming a log normal distribution of data are derived based on capacity and demand of building structures in a probabilistic approach.

• Structural Engineering and Mechanics
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• v.74 no.4
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• pp.481-494
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• 2020

In this paper, a probability-based procedure to evaluate the performance of existing RC structures exposed to seismic and fire actions is presented. The procedure is demonstrated with reference to an existing old school building, located in Italy. The vulnerability assessment of the building highlights deficiencies under both static and seismic loads. Retrofit operations are designed to achieve the seismic safety. The idea of the work consists in assessing the performance of the existing and retrofitted building in terms of both the seismic and fire resistance. The seismic retrofit and fire resistance upgrading follow different paths, depending on the specific configuration of the building. A good seismic retrofit does not entail an improving of the fire resistance and vice versa. The goal of the current work is to study the variation of response due to the uncertainties considered in records/fire curves selection and to carry out the assessment of the studied RC structure by obtaining fragility curves under the effect of different records/temperature. The results show the fragility curves before and after retrofit operations and both in terms of seismic performance and fire resistance performance, measuring the percent improving for the different limit states.

• Korean Journal of Veterinary Research
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• v.48 no.3
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• pp.357-361
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• 2008

Although power analysis is of important tool of research, investigators in veterinary medicine are unaware of the concepts of the statistical power. Two types of error occur in classical hypothesis testing and, those errors should be avoided, if possible. Since power is highly dependent on the sample size, whenever declaring non-statistically significant result they should consider the potential for committing a Type II error in their studies, which refers to the probability of falsely stating that two treatments are equivalent despite true difference between them. Also, sample size determination is one of the most important tasks facing the researcher when planning a diagnostic study, and provides valuable information on the characteristics of a test performance. This type of analysis forms the basis for proper interpretation of test results. The aim of this article was to re-evaluate some selected studies on diagnostic test reported in the domestic veterinary publications to determine the power and necessary sample size for inequality testing to ensure the desired power. Power calculations were illustrated using real-life examples of comparison of a new test and a reference test for detecting antibodies of various animal diseases. Factors affecting to the power were also discussed.

• Korean Journal of Clinical Laboratory Science
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• v.46 no.2
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• pp.68-74
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• 2014

The purpose of this study is to provide an academic basis regarding the necessity of managing depression and stress among metabolic syndrome patients by understanding 5 components of metabolic syndrome, perceived stress, and degree of depression, and by investigating their association using the national nutrition survey reference. This study was conducted by using mental health surveys and health screening test data of the 5th (2010~2012) primitive data of the national health and nutrition survey. A total of 19,599 respondents over 19 years of age were selected for the final analysis. The level of depression and stress was set as the dependent variable to identify its connection with 5 components of the metabolic syndrome. For the stress recognition, none of the metabolic syndrome components showed a significant correlation. For experiencing the depression symptom, the fasting glucose among the factors showed a significant correlation (p<0.05) among the metabolic syndrome factors. When it falls within the criteria of fasting glucose of metabolic syndrome, it has a great probability of falling under the group who experienced greater depression symptoms. As a result of the analysis by controlling cardiovascular and cerebrovascular disease which is tightly related with metabolic syndrome and depression, this study observed that glucose out of 5 metabolic syndrome components is related with depression.

• Wind and Structures
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• v.36 no.2
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• pp.133-147
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• 2023

The random vibration of saddle membrane structures under wind load is studied theoretically and experimentally. First, the nonlinear random vibration differential equations of saddle membrane structures under wind loads are established based on von Karman's large deflection theory, thin shell theory and potential flow theory. The probabilistic density function (PDF) and its corresponding statistical parameters of the displacement response of membrane structure are obtained by using the diffusion process theory and the Fokker Planck Kolmogorov equation method (FPK) to solve the equation. Furthermore, a wind tunnel test is carried out to obtain the displacement time history data of the test model under wind load, and the statistical characteristics of the displacement time history of the prototype model are obtained by similarity theory and probability statistics method. Finally, the rationality of the theoretical model is verified by comparing the experimental model with the theoretical model. The results show that the theoretical model agrees with the experimental model, and the random vibration response can be effectively reduced by increasing the initial pretension force and the rise-span ratio within a certain range. The research methods can provide a theoretical reference for the random vibration of the membrane structure, and also be the foundation of structural reliability of membrane structure based on wind-induced response.

• Journal of the Korean Institute of Landscape Architecture
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• v.19 no.3
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• pp.87-97
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• 1991

The primary purpose of this study is to investigate factors and variables which have significant effects on user's satisfaction with recreational activities in Daeshin Natural Park, thereby establishing directions of development of urban parks. To test the causal models of this research, the data were gathered by self-administered questionnaires form 627 households in Pusan City which were selected by the multi-stage probability sampling method. The analysis of the data primarily consists of two-phase: The first analysis dealt exploratory factor analysis which identified major factors involved in satisfaction with recreational activities in Daeshin Natural Park and the second analysis tested the fit of the causal models of this research by employing LISREL methodology. The factor analysis identified that three factors are involved in satisfaction with recreational actitives. The three factors of satisfaction with recreational activities are facilities for health and phisical exercise, group recreational activity, maintenance activity. The second phase analysis tested the fit of the causal models for satisfaction with recreational activity to the data and identified statistically significant causal linkage among overall satisfaction with Daeshin Natural Park, other endogenous factors and exogenous variables.

• International Journal of Control, Automation, and Systems
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• v.5 no.1
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• pp.104-109
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• 2007

This paper is about a redundancy management system design for the Smart UAV(unmanned aerial vehicle) which utilizes the tilt..rotor mechanism. In order to meet the safety requirement on the PLOC(probability of loss of control) of $1.7{\times}10^{-5}$ per flight hour for FCS (flight control system) failures, a digital FCS is mechanized with a dual redundant structure. A fault detection system which is composed of a CCM(cross channel monitor) and analytic redundancy using the Kalman filtering is designed, and its effectiveness is evaluated through experiments. A threshold level and persistence count for managing redundant sensors are designed based on the statistical analysis of the FCS sensors. To increase the survivability of the UAV after the loss of critical sensors in the SAS(stability augmentation system) and to provide reference information for a tie-breaking condition at which an ILM(in-line monitor) cannot distinguish the faulty channel between two operating ones, the Kalman filter approach is investigated.

• Magazine of the Korean Society of Agricultural Engineers
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• v.38 no.2
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• pp.108-122
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• 1996

This study was to introduced estimation model for optimum probabilistic rainfall intensity on hydrological area. Originally, probabilistic rainfall intensity formula have been characterized different coefficient of formula and model following watersheds. But recently in korea rainfall intensity formula does not use unionize applyment standard between administration and district. And mingle use planning formula with not assumption model. Following the number of year hydrological duration adjust areal index. But, with adjusting formula applyment was without systematic conduct. This study perceive the point as following : 1) Use method of excess probability of Iwai to calculate survey rainfall intensity value. 2) And, use method of least squares to calculate areal coefficient for a unit of 157 rain gauge station. And, use areal coefficient was introduced new probabilistic rainfall intensity formula for each rain gauge station. 3) And, use new probabilistic rainfall intensity formula to adjust a unit of fourteen duration-a unit of fifteen year probabilistic rainfall intensity. 4) The above survey value compared with adjustment value. And use three theory of error(absolute mean error, squares mean error, relative error ratio) to choice optimum probabilistic rainfall intensity formula for a unit of 157 rain gauge station.

• Journal of Microbiology
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• v.34 no.2
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• pp.105-116
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• 1996

Of actinomycetes isolated from volcanic compost soils, 115 representative strains which showed distinctive morphologicla features were numerically classified, compared with reference strains of Streptomyces. One hundred and twenty unit characters were tested and the average probability of error was 4.27%. The cluster analysis resulted in two groups: group A included strains of actinomycetes except streptomycetes. Group A was divided into 2 major clusters (over 5 strains), 10-diaminopimelic acid. Group B was divided into 5 clusters, of which 4 clusters contained mesodiminopimelic acid and 1 cluster LL-diaminopimelic acid. The major clusters of group A showed higher abilities of substrate utilization and degradation, and higher resistance to inhibitors, whereas the minor and single member clusters of group A showed relatively higher antimicrobial activities. On the other hand, all clusters of group B showed relatively lower abilities of substrate utilization and degradation and lower resistance to inhibitors.

• Journal of Navigation and Port Research
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• v.41 no.5
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• pp.287-296
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• 2017

The Formal Safety Assessment (FSA) is a structured and systematic methodology developed by the IMO, aimed at assessing the risk of vessels and recommending the method to control intolerable risks, thereby enhancing maritime safety, including protection of life, health, the marine environment and property, by using risk analysis and cost-benefit assessment. While the FSA has mostly been applied to merchant vessels, it has rarely been applied to a DP vessel, which is one of the special purpose vessels in the offshore industry. Furthermore, most of the FSA has been conducted so far by using the Fault Tree Analysis tool, even though there are many other risk analysis tools. This study carried out the FSA for safe operation of DP vessels by using the Bayesian network, under which conditional probability was examined. This study determined the frequency and severity of DP LOP incidents reported to the IMCA from 2001 to 2010, and obtained the Risk Index by applying the Bayesian network. Then, the Risk Control Options (RCOs) were identified through an expert brainstorming and DP vessel simulations. This study recommends duplication of PRS, regardless of the DP class and PRS type and DP system specific training. Finally, this study verified that the Bayesian network and DP simulator can also serve as an effective tool for FSA implementation.