• Journal of the Korean Society for Precision Engineering
• /
• v.17 no.12
• /
• pp.157-162
• /
• 2000

The object of this work is to develop an assessment system for pipeline integrity. the system consists of four module applications for internal algorithm; the effect of corrosion in pipeline, crack, stress corrosion crack (SCC) and fatigue modules. Presently, the module of the external corrosion has been developed and the internal algorithm for the effect of corrosion in pipeline and the database of the system are described in this paper. The database of the system is separated to mainly four parts; geometry of pipeline, material properties, boundary conditions and general properties. Each components of the system are designed by user-friendly concept. This system may give a guideline for maintenance and modifications for the pipeline at the industrial sight. Furthermore, a procedure to evaluate an inspection interval is also provided.

• Proceedings of the KSRS Conference
• /
• 2003.11a
• /
• pp.628-630
• /
• 2003

Synthetic Aperture Radar(SAR) is an active microwave instrument that performs high-resolution observation under almost all weather condition. Research and algorithms have been proposed to process radar signal and to increase the quality of SAR products. In fact, many complicated steps are involved in order to generate a SAR image product. The purpose of this paper is to derive quality assessment procedures and define important test parameters in each procedure inside a SAR processor. Thus those test parameter values indicate the quality of SAR image products and verify the processor's performance. Moreover, required procedures to correct and handle errors which are indicated during the assessment are also presented.

• Computers and Concrete
• /
• v.12 no.2
• /
• pp.229-241
• /
• 2013

The objective of this study is to reveal the sufficiency of neural networks (NN) as a securer, quicker, more robust and reliable method to be used in seismic assessment of existing reinforced concrete buildings. The NN based approach is applied as an alternative method to determine the seismic performance of each existing RC buildings, in terms of damage level. In the application of the NN, a multilayer perceptron (MLP) with a back-propagation (BP) algorithm is employed using a scaled conjugate gradient. NN based model wasd eveloped, trained and tested through a based MATLAB program. The database of this model was developed by using a statistical procedure called P25 method. The NN based model was also proved by verification set constituting of real existing RC buildings exposed to 2003 Bingol earthquake. It is demonstrated that the NN based approach is highly successful and can be used as an alternative method to determine the seismic performance of each existing RC buildings.

• Structural Engineering and Mechanics
• /
• v.4 no.4
• /
• pp.347-364
• /
• 1996

Presently welded components are designed using S/N curves which predict only the fatigue life of the component. In order to ascertain the condition of the weld at any intermediate period of its life inspection is carried out. If cracks are detected in a weld fracture mechanics is used to find their remaining life. A procedure for assessment is developed here that can be used to verify the condition of a weld before inspection is carried out to detect cracks. This simple method has been developed using linear fracture envelopes by combining S/N curves with linear elastic fracture mechanics.

• Proceedings of the Korea Concrete Institute Conference
• /
• 1999.04a
• /
• pp.229-232
• /
• 1999

Nuclear power plant structures may be exposed to aggressive environmental effects that may cause their damage mechanisms are reasonably well understood and quantitative evaluation of their effects on time-dependent structural behavior is possible in some instances, such evaluations are generally very difficult and remain novel. The assessment of existing steel containment in nuclear power plants for continued service must provide quantitative evidence that they are able to withstand future extreme loads during a service period with an acceptable level of reliability. Rational methodologies to perform the reliability assessment can be developed from mechanistic models of structural deterioration, using time-dependent structural reliability analysis to take loading and strength uncertainties into account. The final goal of this study is to develop the analysis method for the analysis for the reliability of containment structures. The cause and mechanism of corrosion is first clarified and the reliability assessment method has been established. By introducing the equivalent normal distribution, the procedure of reliability analysis which can determine the failure probabilities has been established.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.56 no.2
• /
• pp.254-259
• /
• 2007

PM(Preventive Maintenance) can avail the generating unit to reduce cost and gain more profit in a competitive supply-side power market. So, it is necessary to perform reliability analysis on the power systems in which reliability is essential. Thus, to schedule optimal PM planning based on reliability that is defined RCM(Reliability-Centered Maintenance), FMECA(Failure Mode Effects and Criticality Analysis) assessment is very important. Therefore, in this paper, the procedure of FMECA assessment for optimal RCM is proposed by probabilistic approach using real historical failure data of combustion-turbine generators in Korean power systems. The stochastic FMECA is performed based on the effects of probable failure modes of combustion-turbine generating unit.

• Journal of Society of Preventive Korean Medicine
• /
• v.22 no.2
• /
• pp.33-40
• /
• 2018

Objectives : Health literacy can affect medical results. This study aimed to detect to the modify point of health literacy assessment tools. Methods : The general Korean Medicine service procedure was recorded and categorized. The participants were in- or out-patient of Korean Medical hospital. Written informed consents were obtained. Results : A total of 20 patients participated, with nine males and eleven females. The chief complaints were pain, growth, cerebral infarction sequela, dyspepsia, diarrhea, feeling of helplessness, mental stress, postpartum symptoms, and menstrual disorder. The Korean Medicine service were categorized into collecting patient information, relationship building, and treatment. Terms used in the service embraced general medical terms and Korean Medical terms. Conclusions : The Korean-medical health literacy assessment tool should incorporate western-eastern combined treatment and Korean medical terms.

• Journal of Environmental Impact Assessment
• /
• v.8 no.1
• /
• pp.17-27
• /
• 1999

Applicability of LCA in establishing the integrated solid waste management were examined. Data were collected from current waste management system. LCA method was then applied to find environmentally sustainable waste management. The process comprises five steps : (1) collecting data, comparing the data with comprehensive urban planning as well, (2) analyzing the current waste treatment procedure leading to the database establishment, (3) LCA for the waste management system, (4) finding alternative scenarios based on the former steps, (5) establishing the optimum method in Ecopolis, best fitted to the local situation. The results and suggestions in this study are expected to yield comprehensive analysis as to current practices in waste management. More importantly it will be a valuable data in minimizing environmental burdens in connecting with living environments of Ecopolis. Information regarding the urban system and total environmental quality are expected from this study.

• Computers and Concrete
• /
• v.5 no.2
• /
• pp.135-154
• /
• 2008

This paper presents a nonlinear finite element analysis procedure for the seismic performance assessment of reinforced concrete bridge piers with unbonded reinforcing or prestressing bars. A computer program named RCAHEST (Reinforced Concrete Analysis in Higher Evaluation System Technology) is used to analyze reinforced concrete structures; this program was also used in our study. Tensile, compressive and shear models of cracked concrete and models of reinforcing and prestressing steel were used account for material nonlinearity of reinforced concrete. The smeared crack approach was incorporated. To represent the interaction between unbonded reinforcing or prestressing bar and concrete, an unbonded reinforcing or prestressing bar element based on the finite element method was developed in this study. The proposed numerical method for the seismic performance assessment of reinforced concrete bridge piers with unbonded reinforcing or prestressing bars is verified by comparison of its results with reliable experimental results.

• Earthquakes and Structures
• /
• v.2 no.1
• /
• pp.25-42
• /
• 2011

This paper discusses a mechanical model for the vulnerability assessment of old masonry building aggregates that takes into account the uncertainties inherent to the building parameters, to the seismic demand and to the model error. The structural capacity is represented as an analytical function of a selected number of geometrical and mechanical parameters. Applying a suitable procedure for the uncertainty propagation, the statistical moments of the capacity curve are obtained as a function of the statistical moments of the input parameters, showing the role of each one in the overall capacity definition. The seismic demand is represented by response spectra; vulnerability analysis is carried out with respect to a certain number of random limit states. Fragility curves are derived taking into account the uncertainties of each quantity involved.