• Journal of the Korea Safety Management & Science
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• v.14 no.3
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• pp.127-134
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• 2012

Plant safety management that is enforcing introducing more than 95% in domestic manufacturing industry is using total plant efficiency by the evaluation index, and as a result, can see a lot of examples that plant productivity, economy and safety is increased. The efficient safety estimation for a business should analyze an accident data by considering every possible and potential factor. This study's purpose centers plant safety management activities that is management system for plant production and safety efficiency's maximization, plant evaluation system that plant safety management activities factor(reliability, maitainability, safety, service quality) that is enforcing in manufacturing industry can develop evaluation model that can evaluate qualitative activities by quantitative activities in process that maximize plant safety management wishes to do design.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2001.04a
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• pp.207-214
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• 2001

In Korea, the multi-dwelling residential buildings are most popular housing system that is reinforced concrete shear wall system. However, the serviceability and safety of the system have been decreased because of the errors in design or construction and inadequate maintenance. In addition the safety of the system cannot be evaluated reasonably because the system is analyzed by the deterministic approach. Therefore, this study is aimed to analyze reinforced concrete shear walls by the reliability approach considering uncertainty based on the probability theory. In this study, a reliability analysis program using MATLAB is developed by combining AFOSM and Sampling Method for the reinforced concrete shear walls within feasible design area. The reasonable reliability index β of ultimate limit states for RC shear walls are calculated automatically using this developed program with the measured data those have means and standard deviations in the field. The ultimate states are compression failure, tension failure, governing compression, and governing bending of the reinforced concrete shear walls respectively. To estimate the safety of the system using developed program can be used to predict residual life-time of the system.

• Proceedings of the KSR Conference
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• 2001.05a
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• pp.217-221
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• 2001

Barber bogie and Y25 bogie is the main bogie of freight car which is used in the Korean railway. In case of Barber bogie and a mixed formation tile maximum speed limit of empty car is 70 km/h and that of loaded car is 90 km/t and also it runs a speed of 110 km/h in time of an exclusive formation of Y25 bogie. The car named as high speed freight car at present is Y25 bogie which modeled on the Y25 bogie or Europe developed in 1993, Y25 bogie has no problem about the running capacity up to the speed of 110 km/h, but it works as limiting factors to tile increasing cost of maintenance and repair expenses which caused by repair of bogie and the cost of materials. This study is going to describe the contents examined by analysis and tests, aimed at being used as an index of plan in the future through the strength test of high speed freight car which is used now.

• Proceedings of the Safety Management and Science Conference
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• 2004.11a
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• pp.189-195
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• 2004

It compared quality characteristics for the stone surface treatment system and its products. With the result, the flame burner equipment was mainly used to the surface treatment of granite, but it occurred greatly the high temperature, the rock fragment, the noise and dust. For the other side, the whetstone polishing machine for the polishing was a maintenance for the specific physical properties of stone, and it did not occur the stone fragment and the dust. The durability of the stone products due to the flame burner was investigated with that it falls to $20\sim25\%$ more than the surface treatment by the whetstone polishing. Share's hardness of the polishing products in the durability test showed more greatly index than the flame burner and conventional product. The polishing products of Pochon stone in the case of the abrasion resistance showed great more $15\%$ than the general products, more $9\%$ than the products by the flame burner.

• Journal of Magnetics
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• v.16 no.3
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• pp.259-262
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• 2011

Compared to acupuncture, the pulsed magnetic field (PMF) stimulus is a useful tool for treatment of many physical conditions and health maintenance due to its advantages as a noninvasive and nontoxic medical treatment. The purpose of this study was to investigate the effect of PMF stimulus direction at PC9 on the alpha activity of electroencephalogram (EEG) and vascular aging calculated from photoplethysmograph (PPG). It can be concluded that the direction of PMF stimulus affects the increase of alpha activity of EEG and PPG, indicating the vascular stiffness and the sclerosis level of blood vessels weakly relevant to the direction of PMF stimulus.

• Proceedings of the KSR Conference
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• 2005.11a
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• pp.655-659
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• 2005

The environment. of electric railway has, included both fast and slow load variation, which may occur in the office or maintenance factory or running electric train. This paper investigated flicker indices according to voltage fluctuations on three different situations; The base office in new subway in the daytime and night time, inside of electric train running in conventional subway. And also the variations of harmonic frequencies(2nd, 3rd, 5th) with rime were measured at the same time. Flicker index is a good tool for evaluating the voltage fluctuation quantitatively and show some relationship with even harmonic frequencies produced by the voltage fluctuation when the electric train is running on the railway.

• Archives of Pharmacal Research
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• v.11 no.4
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• pp.301-307
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• 1988

Relationship between the maintenance of hypertension and central serotonergic nervous system activity in opontaneously hypertensive rats (SHR) was studied. Serotonin turnover-rates were measured in 5 brain areas as an index of serotonergic neuronal activity and compared at the ages of 14 weeks in two types of animals; (1) spontaneously hypertensive rats (SHR) (2) normotensive wistar kyoto rats (WKY). In 14-week old SHR, central serotonin turnover rate was significantly lower in telencephalon, hypothalamus/thalamus and midbrain than normotensive rat, but significantly higher in cerebellum. There were no significant differences between serotonin turnover rate in pons/medulla of SHR and that of normotensive rat. THese data suggest that the abnormally lower turnover rates of serotonin in telencephalon, hypothalamus/thalamus and midbrain may be one of the underlying neuronal factors for manifestation of hypertension in SHR.

• Structural Monitoring and Maintenance
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• v.2 no.3
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• pp.237-252
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• 2015

This paper addresses the issue of reliability and performance in wireless sensor networks (WSN) based structural health monitoring (SHM), particularly with decentralized damage identification techniques. Two decentralized damage identification algorithms, namely, the autoregressive (AR) model based damage index and the Wiener filter method are developed for structural damage detection. The ambient and impact testing have been carried out on the steel beam structure in the laboratory. Seven wireless sensors are installed evenly along the steel beam and seven wired sensor are also installed on the beam to monitor the dynamic responses as comparison. The results showed that wireless measurements performed very much similar to wired measurements in detecting and localizing damages in the steel beam. Therefore, apart from the usual advantages of cost effectiveness, manageability, modularity etc., wireless sensors can be considered a possible substitute for wired sensors in SHM systems.

• Journal of information and communication convergence engineering
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• v.17 no.2
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• pp.128-134
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• 2019

Based on the concept of Industry 4.0, various sensors are attached to facilities and equipment to collect data in real time and diagnose faults using analyzing techniques. Diagnostic technology continuously monitors faults or performance degradation of facilities and equipment in operation and diagnoses abnormal symptoms to ensure safety and availability through maintenance before failure occurs. In this paper, we propose a model to analyze the data and diagnose the state or failure using machine learning. The diagnosis model is based on a support vector machine (SVM)-based diagnosis model and a self-learning one-class SVM-based diagnostic model. In the future, it is expected that this model can be applied to facilities used in the entire industry by applying the actual data to the diagnostic model proposed in this paper, conducting the experiment, and verifying it through the model performance evaluation index.

• Structural Monitoring and Maintenance
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• v.6 no.3
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• pp.173-190
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• 2019

Steel-confined reinforced concrete (SCRC) columns feature highly complex and invisible mechanisms that make damage evaluation and pattern recognition difficult. In the present article, the prevailing acoustic emission (AE) technique was applied to monitor and evaluate the damage process of steel-confined RC columns in a quasi-static test. AE energy-based indicators, such as index of damage and relax ratio, were proposed to trace the damage progress and quantitatively evaluate the damage state. The fuzzy C-means algorithm successfully discriminated the AE data of different patterns, validity analysis guaranteed cluster accuracy, and principal component analysis simplified the datasets. A detailed statistical investigation on typical AE features was conducted to relate the clustered AE signals to micro mechanisms and the observed damage patterns, and differences between steel-confined and unconfined RC columns were compared and illustrated.