• Journal of the Korea Institute of Building Construction
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• v.21 no.5
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• pp.507-518
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• 2021

The application of an adhesive calcium carbonate-based hybrid insulation board with quasi-combustibility in the external thermal insulation composite system(ETICS) ensures effective thermal performance and fire safety. This study aimed to conduct a mechanical test of the quasi-non-combustible hybrid insulation board as well as its constituent materials to obtain the basic data for the structural design of the adhesive ETICS. Test specimens were fabricated based on domestic and foreign test standards to examine and evaluate their tensile, compressive, flexural, and shear strengths. The strength characteristics of the quasi-non-combustible hybrid insulation board were identified from the test results, which verified that the minimum required physical properties suggested by the current KS M ISO 4898 were met. Furthermore, the quasi-non-combustible ETICS used in this study was found to be suitable for use as an external insulation system for walls unless subjected to continuous gravity load, such as a heavy exterior finish.

• Journal of Biomedical Engineering Research
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• v.40 no.6
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• pp.250-259
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• 2019

Ophthalmic Laser System is widely used in Selective Laser Trabeculoplasty of Open Angle Glaucoma and Ocular Hypertension. Versatile ophthalmic laser system is a medical device with technology that checks the condition of the treatment area by irradiating a continuous laser pulse on the treatment area, and monitoring the microbubble reaction caused by the temperature increase of the melanosome through the ultrasonic signal and the optical signal sensor. It performs selective laser treatment without damaging the photoreceptor by controlling the wavelength of the laser when microbubbles are detected. This study aims to suggest a guideline for evaluating safety, performance and clinical effectiveness of Versatile Ophthalmic Laser System in accordance with the growing technology. International Standards, Regulations, and Clinical Trial Protocols were investigated and analyzed for this study. As a result of this study, the safety, performance and clinical effectiveness test guideline for Versatile Ophthalmic Laser System were proposed. This guideline will ensure the safety and efficacy of Medical device, and furthermore it is expected to be able to promote the development of technology development by supporting a clinical trial plan.

• Journal of the Korea institute for structural maintenance and inspection
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• v.25 no.1
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• pp.93-102
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• 2021

This paper describes the process of developing a concrete median barrier of SB4 grade with anti-glare function. The development section has a height and width of 1,270mm and 560mm, respectively. A wire mesh is placed in the center of the cross section to improve the protection performance. Collision analysis predicted that this section satisfies the strength and occupant protection performance, and that no damage to the barrier occurs. In the actual collision test, it was confirmed that this section satisfies the strength and occupant protection performance. However, damage was observed on two concrete barrier when the truck crashed. In order to improve the accuracy of the collision analysis of the concrete barrier in the future, it is considered that a study on the model development and continuous collision analysis method for domestic commercial vehicles should be carried out.

• Journal of the Korea institute for structural maintenance and inspection
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• v.28 no.3
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• pp.59-65
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• 2024

In this study, in order to improve the mechanical properties and durability of asphalt mixtures, a modifier (CSM, Cationized Silicate Modifier) was applied to asphalt to derive optimal mixing ratio conditions. Design of asphalt mixture using modified asphalt binder was conducted, and moisture resistance and dynamic stability were evaluated for optimal mixing conditions. The evaluation results showed that it exceeded the standards stipulated in the relevant guidelines, and as a result of conducting a water permeability test on the optimal mixing condition, it was confirmed that impermeable performance was secured. As a result of examining the noise reduction performance through field test, a noise reduction performance of about 10 dB was secured compared to before paving. It will be necessary to secure reliability through continuous noise generation evaluation in the future.

• Journal of the Korean Institute of Gas
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• v.26 no.3
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• pp.27-37
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• 2022

With the recent increase in the spread of ESS (Electric Storage System), the damage to human life and property is also rapidly increasing due to continuous fires caused by ESS. In the manufacture of urethane sandwich panels used in ESS, it is necessary to improve the flame retardant performance. In this study, in order to realize the flame retardant properties of flexible polyurethane foam, the effect of the tissue density of the product due to the change of the isocyanate functional group parameter that changes the physical properties of the product on the fire performance was studied. The product was manufactured by changing the density of the urethane structure, and combustion performance tests, gas toxicity tests, and smoke density tests were performed. As a result, it was confirmed that the total amount of heat released had excellent performance when the isocyanate functional group was high, and had no correlation with the maximum heat release rate. When the value of the isocyanate functional group was 2.7 or more, the collapse of the shape could be prevented. In the gas hazard test, the performance was increased when the isocyanate functional group was relatively high, so a flame retardant for the Char system, which had a dense structure and easy to form a carbonized film, was added. confirmed to be. Therefore, as a result of this study, it is thought that it will be possible to lay the foundation for the development of a flame retardant to replace the cheap urethane sandwich panel used in the past.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.3180-3186
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• 2011

A segmented scissors type switch has been developed for the urban transit maglev demonstration line to be commercialized near Incheon International Airport in 2013. Based on the design of the previous segmented 3-way switch, the scissors switch is composed of four segmented 2-way switches up/down and left/right and a turn table in the mid point. The main function of the scissors switch is to change the running direction of the train at end terminals. The developed scissors switch is planned to be installed in front of the 102 station, which has a side platform, of the demonstration line. The total length of the switch is 65m and the distance between the up and down track centerlines is 6m. The 2-way switches and turn table are made of steel box type beams, and have their own driving unit, locking unit, control unit, levitation and propulsion rails, and so on. Installed in the factory, a 100,000-cycle continuous operation test was carried out after manual and automatic test operations. The applicapability of the developed switch was verified through the measurements of the linearity of the track after repetitive operations, the mechanical operation noise, the load of the main driving motor, the safety of the control panel, the natural frequency of the girder, the deformation of the girder, and so on.

• Communications for Statistical Applications and Methods
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• v.26 no.2
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• pp.205-216
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• 2019

Diagnostic tests in medical fields detect or diagnose a disease with results measured by continuous or discrete ordinal data. The performance of a diagnostic test is summarized using the receiver operating characteristic (ROC) curve and the area under the curve (AUC). The diagnostic test is considered clinically useful if the outcomes in actually-positive cases are higher than actually-negative cases and the ROC curve is concave. In this study, we apply the stochastic ordering method in a Bayesian hierarchical model to estimate the proper ROC curve and AUC when the diagnostic test results are measured in discrete ordinal data. We compare the conventional binormal model and binormal model under stochastic ordering. The simulation results and real data analysis for breast cancer indicate that the binormal model under stochastic ordering can be used to estimate the proper ROC curve with a small bias even though the sample sizes were small or the sample size of actually-negative cases varied from actually-positive cases. Therefore, it is appropriate to consider the binormal model under stochastic ordering in the presence of large differences for a sample size between actually-negative and actually-positive groups.

• Land and Housing Review
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• v.8 no.3
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• pp.161-169
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• 2017

In this study, sediment transfer and precipitation analysis of the test bed watershed was conducted through the model for the application and practical use of the urban sediment disaster prevention technology, and used this as an aid to design to secure reliability. In addition, conducted the test bed monitoring with the defense technology, analyzed the effect, and established the maintenance plan. Analyzed the change of soil deposition volume through arbitrary slope adjustment for the currently installed stormwater conduit of the test bed watershed. As a result, it is important to reduce the total sedimentation amount in the adjustment of the slope of the entire pipeline, but it is important that the sedimentation depth of each sediment does not rise to such a degree as to threaten the performance of the pipeline. Considering these matters, it is necessary to design the pipeline to prevent the clogging of the soil from the viewpoint of the reliability of the entire pipeline. The sediment disaster defense technology test bed is divided into a new city and an old city, and old city test bed is under construction. The result obtained through the monitoring of the test bed in the new city, sediment disasters such as debris can delay the time to reach the downtown area, and it is possible to secure the golden time, such as evacuation and rescue through the warning system. Also, the maintenance of the test bed application was suggested. Continuous and systematic monitoring is required for securing the reliability of element technology and successful commercialization.

• Proceedings of the KIEE Conference
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• 2001.07a
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• pp.249-251
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• 2001

This paper presents performance analysis on a low pass filter of a CT saturation detecting algorithm using difference. At the instants of beginning/end of saturation, the shapes of the secondary current are changed significantly though secondary currents are continuous. At the instants, the second-order or third-order difference of the secondary current has big values because of discontinuity of the first order difference. Thus, the third difference of the current is used to detect the beginning/end of CT saturation. An antialiasing low pass filter removes high frequency components and causes phase lag. A CT saturation detecting algorithm using difference of CT secondary currents is affected by the low pass filter. The algorithm is tested with cutoff frequencies of the filter for the two sampling rates of 64[S/C] and 32 [S/C]. The results of various test cases indicate satisfactory performance of the algorithm.

• Journal of Digital Convergence
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• v.13 no.2
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• pp.135-140
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• 2015

General CHMM vocabulary recognition system is model observation probability for vocabulary recognition of recognition rate's low. Used as the limiting unit is applied only to some problem in the phoneme model. Also, they have a problem that does not conform to the needs of the search range to meaning of the words in the vocabulary. Performs a phoneme recognition using GMM to improve these problems. We solve the problem according to the limited search words characterized by an improved k-means algorithm. Measure the effectiveness represented by the accuracy and reproducibility as compared to conventional system performance experiments. Performance test results accuracy is 83%p, and recall is 67%p.