• Journal of architectural history
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• v.21 no.3
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• pp.7-28
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• 2012

This study is intended to Mindori structure which is general private houses' structural type among traditional types and is a basic study to confirm structural characteristics of Hwatong connection which is general connection type of column-beam-cross beam. It is aimed to analyze how main member, column, such as size, figure, thickness of Sungetuk and Dugeup affect on structure. Following conclusions are drawn. 1. According to connection conditions, models with big coefficient of friction show stable hysteretic behavior until the angle rotation of member reaches 1/60 and models with small coefficient of friction show dramatical increase in load after the angle rotation of member reaches 1/24. After the angle rotation of member reaches 1/30, separation distance of members is identified physically and cracks are not observed. 2. Specimens with big coefficient of friction show similar inner force regardless of column size(except column size 150mm) and models with small coefficient of friction show increasing inner force as the column size increases. Specimens with same sectional area have similar inner force even though the column figures are different. The thickness of Sungetuk and Dugeup doesn't affect inner force greatly, however, when the thickness of Sungetuk is thin, it could lead to failure of structure as it breaks. 3. The bigger the size of column and the coefficient of friction are, the smaller Bending stiffness depreciation ratio is. 4. Energy Dissipation Efficiency differs from the coefficient of friction. When the coefficient of friction is big, square column shows bigger than round one and it is bigger when the thickness of Sungetuk and Dugeup is thicker. When the coefficient of friction is small, round column shows bigger than square one.

• Tribology and Lubricants
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• v.35 no.4
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• pp.229-236
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• 2019

This study investigates the stress singularity that occurs at the contact edge of three bodies in a frictional complete contact. We use the asymptotic analysis method, wherein we constitute an eigenvalue problem and observe the eigenvalue behavior, which we use to obtain the order of the stress singularity. For the present geometry of three bodies in contact, a contact between a cracked indenter and half plane is considered. This is a typical geometry of the PCMI problem of a nuclear fuel rod. Thus, this paper, specifically presents the characteristics of the PCMI problem from the perspective of stress singularity. Consequently, it is noted that the behavior of the stress singularity varies with the difference in the crack angle, coefficient of friction, and material dissimilarity, as is observed in a frictional complete contact of two bodies. In addition, we find that the stress singularity changes essentially linearly with respect to the coefficient of friction, regardless of the variation in the crack angle and material dissimilarity. Concurrently, we find the order of singularity to be 0.5 at a certain coefficient of friction, irrespective of the crack angle, which we also observe in the crack problem of a homogeneous and isotropic body. The order of singularity can also exceed 0.5 in the frictional complete contact problem of three bodies. This implies that the propensity for failure when three bodies are in frictional complete contact can be even worse than that in case of a failure induced by a crack.

• Journal of the Korean Society for Precision Engineering
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• v.18 no.8
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• pp.48-53
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• 2001

In order to increase productivity and efficiency, high-speed rotating machines become popular these days. The high-speed rotating machine is likely to vibrate and cause machine failure even though it has small unbalance. Therefore, a balancing technique is studied in this paper. Off-line balancing methods are inadequate to solve unbalance vibration problem occurring in the field due to flexible rotor effect, faster tool change, and shorter spin-up and down, etc. An active balancing is suggested to allow re-balancing of the entire rotating assembly in the machine when a tool is changed. This paper shows how to identify the dynamics of the system using influence coefficient and suggest an active balancing technique based on influence coefficient method for high-speed spindle system.

• Journal of Information Technology Applications and Management
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• v.25 no.2
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• pp.109-116
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• 2018

In this study, we was compared the reliability performance of the software reliability model, which applied the Goel-Okumoto model developed using the exponential distribution, to the logarithmic function modifying the intensity function and the Rayleigh form. As a result, the log-type model is relatively smaller in the mean squared error compared to the Rayleigh model and the Goel-Okumoto model. The logarithmic model is more efficient because of the determination coefficient is relatively higher than the Goel-Okumoto model. The estimated determination coefficient of the proposed model was estimated to be more than 80% which is a useful model in the field of software reliability. Reliability has been shown to be relatively higher in the log-type model than the Rayleigh model and the Goel-Okumoto model as the mission time has elapsed. Through this study, software designer and users can identify the software failure characteristics using mean square error, decision coefficient. The confidence interval can be used as a basic guideline when applying the intensity function that reflects the characteristics of the lifetime distribution.

• Journal of the Korean Geosynthetics Society
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• v.17 no.4
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• pp.53-64
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• 2018

In this study, the evaluation to probability of failure for risk assessment of port structures on DCM reinforced soils, where stability and risk assessment are increasing in importance, was performed. As a random variables affecting the risk of DCM improved ground, the design strength, superposition (overlap) of construction, strength of the natural ground, internal friction angle and unit weight of the modified ground were selected and applied to the risk assessment. In addition, the failure probability for the entire system under ordinary conditions and under earthquake conditions were analyzed. As a result, it was found that the highest coefficient of variation in the random variable for the risk assessment of the DCM improved ground is the design strength, but this does not have a great influence on the safety factor, ie, the risk of the system. The main risk factor for the failure probability of the system for the DCM reinforced soils was evaluated as horizontal sliding in case of external stability and compression failure in case of internal stability both at ordinary condition and earthquake condition. In addition, the failure probability for ordinary horizontal sliding is higher than that for earthquake failure, and the failure probability for ordinary compression failure is lower than that for earthquake failure. The ordinary failure probability of the entire system is similar to the failure probability on earthquake condition, but in this case, the risk of earthquake is somewhat higher.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.9 no.2
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• pp.141-147
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• 2016

NHPP software reliability models for failure analysis can have, in the literature, exhibit either constant, monotonic increasing or monotonic decreasing failure occurrence rates per fault. In this paper, infinite failures NHPP models that repairing software failure point in time reflects the situation, was presented for comparing property. Commonly used in the field of software reliability based on Flexible Weibull extension distribution software reliability of infinite failures was presented for comparison problem. The result is that a relatively small shaping parameter was effectively. The parameters estimation using maximum likelihood estimation was conducted and model selection was performed using the mean square error and the coefficient of determination.. In this research, software developers to identify software failure property follows shape parameter, some extent be able to help is considered.

• Journal of Forest and Environmental Science
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• v.14 no.1
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• pp.145-156
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• 1998

On the basis of data obtained from 5 forest roads(Backyang, Byongatae, Saorang, Bukyu and Dangrim forest road) collapsed under a heavy rainfall in Chunchon, Kangwondo, this study was carried out to predict the cutting slope failure of forest road by using Quantification theory(II). The results were summarized as follows; The cutting slope failure was chiefly occurred by correlated action of road structure, vegetation and topographical factors. The cutting slope failure predicted by partial correlation coefficients and range values was characterized by longer than 8m of cutting slope length, depper than 2.5m of soil depth, between $30^{\circ}$ and $50^{\circ}$ of original ground slope gradient, absence of vegetation coverage on cutting slope, and greater than $60^{\circ}$ of cutting slope gradient. And the rate of correct discrimination by analysis of cutting slope failure was 90.1%.

• Journal of Korean Biological Nursing Science
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• v.12 no.2
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• pp.114-126
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• 2010

Purpose: To examine the levels of the disease-related knowledge and educational demands of pre-dialysis, chronic renal failure patients at different GFRs and stages. Methods: This study used a cross-sectional survey and aimed at 116 pre-dialysis, chronic renal failure patients, who were registered and received regular treatment from December 1 to December 31, 2009 at the nephrology departments of tertiary medical centers in Seoul. Stages were classified into Stage 3, 4 and 5 depending on GFR ranges. To measure the levels of knowledge and educational demands, the tool, which were first invented by Young Ae Lim (1996) and then modified by Hyo Sun Lim (2005) to adjust the knowledge and educational demands measuring tool for hemodialysis patients to pre-dialysis patients with chronic renal failure, was used. Collected data was analyzed with the SPSS WIN 12.0 program (average, standard deviation, Pearson's correlation coefficient, t-test and ANOVA). Results: There was a significant difference in the disease-related knowledge levels of the subjects at each stage (F=24.41, p=.000). The Scheffe post hoc test confirmed that patients at higher stages had higher levels of knowledge of their disease. Also, although the results showed that patients at higher stages had higher educational demands, there was no significant difference among the groups (F=1.259, p=.288). Conclusion: As patients have different levels of knowledge of the disease and educational demands depending on their stages, it is important to develop and use a systematic education program that reflects the demands and levels of patients at each stage in order to help pre-dialysis patients with chronic renal failure with self-management and improve their quality of life.

• Nuclear Engineering and Technology
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• v.52 no.8
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• pp.1871-1880
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• 2020

Round robin analyses for vessel failure probabilities due to PTS events are proposed for plant-specific analyses of all types of reactors developed in Korea. Four organizations, that are responsible for regulation, operation, research and design of the nuclear power plant in Korea, participated in the round robin analysis. The vessel failure probabilities from the probabilistic fracture mechanics analyses are calculated to assure the structural integrity of the reactor pressure vessel during transients that are expected to initiate PTS events. The failure probabilities due to various parameters are compared with each other. All results are obtained based on several assumptions about material properties, flaw distribution data, and transient data such as pressure, temperature, and heat transfer coefficient. The realistic input data can be used to obtain more realistic failure probabilities. The various results presented in this study will be helpful not only for benchmark calculations, result comparisons, and verification of PFM codes developed but also as a contribution to knowledge management for the future generation.

• Journal of Korean Society of Forest Science
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• v.90 no.3
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• pp.324-330
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• 2001

This study was carried out to develop prediction model for fill slope failure of forest road in igneous rock area using fuzzy theory which is non-linear model. The results were summarized as follows. The importance weight of factors on fill slope failure was ranked in the order of fill slope length, fill slope gradient, soil type, aspect, road position and longitudinal slope form. The degree of potential slope failure was high mainly under the such conditions as fill slope length greater than 8m, fill slope gradients steeper than $40^{\circ}$, constituent material with weathered rock, aspect of NE and road on ridge position. The optimal prediction model was developed with 0.15 of optimal coefficient(c) and 3.1165 of ${\lambda}$-value when fuzzy integral value of slope failure possibility is more than 0.5. And the discriminant accuracy was 86.8%, which shows the high availability for discrimination.