• Fire Science and Engineering
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• v.26 no.3
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• pp.73-78
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• 2012

This study is intended to understand flame behavior of pool and whirl fire by height of fire source. Liquid fuel was methanol which is used in many studies for pool and whirl fire. Size of vessel was $100{\times}100{\times}50$ and the vessel was made by stainless steel. Combustion time, mass loss rate, flame temperature, flame height and air entrainment rate from the outside to flame were measured, and flame behavior was visualized with video camera. Based on the experiment, it was found that combustion characteristics by height of fire source got a more effect on whirl fire than pool fire.

• Journal of the Korean Institute of Telematics and Electronics
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• v.27 no.9
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• pp.1409-1418
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• 1990

Characteristics of NMOS transistors with phosphorus source/drain junctions formed by two-step rapid thermal diffusion (RTD) process using a solid diffusion source have been investigated. Phosphorus profiles after RTD were measured by SIMS analysis. In the case of 1100\ulcorner, 10sec RTD of, P, the specific contact resistance of n+ Si-Al was 2.4x10**-7 \ulcorner-cm\ulcorner which is 1/5 of the As junction The comparison fo P junction devices formed by RTD and conventional As junction devices shows that both short channel effect and hot carrier effect of P junction devices are smaller than those of As junction devices when the devices have same junction depths. P junction device had maximum of 0.4 times lower Isub/Id than As junction device. Characteristics of P junction formed by several different RTD conditions have been compared and 1000\ulcorner RTD sample had the smaller hot carrier generation. Also, it has been shown that the hot carrier generation can be futher reduced by forming the P junctions by 3-step RTD which has RTO-driven-in process additionally.

• Journal of radiological science and technology
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• v.45 no.2
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• pp.117-125
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• 2022

Although stationary inverse-geometry digital tomosynthesis (s-IGDT) is able to reduce motion artifacts, image acquisition time and radiation dose, the image quality of the s-IGDT is degraded due to the truncations arisen in projections. Therefore, the effects of geometric and image acquisition conditions in the s-IGDT should be analyzed for improving the image quality and clinical applicability of the s-IGDT system. In this study, the s-IGDT images were obtained with the various X-ray source arrangement types and the various number of projections. The resolution and noise characteristics of the obtained s-IGDT images were evaluated, and the characteristics were compared with those of the conventional DT images. The s-IGDT system using linear X-ray source arrangement and 40 projections maximized the image characteristics of resolution and noise, and the corresponding system was superior to the conventional DT system in terms of image resolution. In conclusion, we expect that the s-IGDT system can be used for providing medical images in diagnosis.

• Journal of Korean Society on Water Environment
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• v.24 no.2
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• pp.169-173
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• 2008

A field monitoring was conducted in order to find out the discharge characteristics of non-point source pollutants in the agricultural area. Event Mean Concentration (EMC) of TSS, $BOD_5$, $COD_{Mn}$, TP, TN was calculated based on the monitoring data of 10 rainfall events at agricultural watersheds. A significant relationship was observed from the correlation between EMCs and rainfall characteristics. The result shows that EMC ranges of 95% confidence intervals were 50.5~203 mg/L for TSS, 0.8~14.2 mg/L for $BOD_5$, 4.2~20.7 mg/L for $COD_{Mn}$, 2.4~4.5 mg/L for TN and 0.2~0.5 mg/L for TP, respectively. The correlation coefficients between TSS and TP and between $BOD_5$ and $COD_{Mn}$ were found to be 0.912 and 0.961. But TN was lower correlated with other EMC factors. It was also found that rainfall characteristics was not correlated with EMCs.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.21 no.7
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• pp.68-74
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• 2007

For carnation productivity improvement, compact-low cost discharge lamp type ozonizer using pulse power source is designed and manufactured. This paper describes the discharge characteristics and the ozone generation characteristics with variation of the output voltage of pulse power source, the quantity of flowing air and the operating number of ozonizer. The important conclusions are as follows. The discharge voltage and current values are proportional to the output voltage of pulse power source. The ozone concentration and generation are proportional to the output voltage of pulse power source and the number of ozonizer. The maximum value of the ozone concentration and generation of the discharge lamp type ozonizer can be obtained 890[ppm] and 59.7[mg/h] respectively. In the carnation productivity house, when the discharge lamp type ozonizer is used the carnation is good quality in the uniformity of the carnation stalk thickness and increased the productivity through improvement of the air and the soil.

• The Research Journal of the Costume Culture
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• v.29 no.4
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• pp.554-571
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• 2021

The purpose of this study is to investigate the mediating effect of trust when a media broadcaster (such as a disc jockey [DJ]) acting as an information source and the content they provide during live commerce streaming affect acceptance intention. Live commerce is increasing rapidly, offering a new fashion distribution channel by supplementing possible shortcomings of existing online shopping. Data was collected for the empirical study from female consumers in their 20s who actively accepted fashion technology. Statistical analysis of the data was conducted using IBM SPSS Macro Process 3.5. First, the reliability and validity of the variables for information source characteristics, content informativeness, trust, and acceptance intention were verified, and each variable was confirmed as a single factor. Bootstrap analysis was performed using Macro Process Model 4 to reveal the effects of information source characteristics and content informativeness on acceptance intention. As a result of analyzing the mediating effect for each path model with trust as a parameter, it was found that both the direct and indirect effects of the mediating path were significant. This result means that the characteristics of information sources and content informativeness are partially mediated by trust. Therefore, to promote consumer behavior in a live commerce shopping environment, it is necessary to enhance trust. This can be achieved by a media broadcaster with fashion expertise to increase the perception of the attractiveness of the information source and to improve the usefulness of the fashion information being delivered.

• Journal of Electrical Engineering and Technology
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• v.3 no.3
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• pp.300-307
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• 2008

Event source locating is very important to improving the power quality level. This paper presents a method to determine the relative location of the voltage sag source according to the cause. For this, the concept of the relative location of the source is defined first. Then, the main causes of voltage sag are classified and their characteristics are discussed. From these investigations, the rules to determine the relative location of event source are proposed for each type and the overall algorithm to identify the relative location and the kind of event source is presented. Finally, the proposed method is applied to the IEEE 13-bus test system and it is verified that the method can help to pinpoint the accurate location of the event source.

• 한국지구물리탐사학회:학술대회논문집
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• 2007.06a
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• pp.279-284
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• 2007

The cultural noise sources in magnetotellurics were localized using the source localization method. Conventional beamforming techniques are not applicable for electromagnetic source localization. In this study, the matched field processing and genetic algorithm are used to localize an electromagnetic source and estimate the polarization direction. The source localization using MT field data shows the characteristics of estimated source distribution related to the strength of cultural noise.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.11a
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• pp.804-807
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• 2005

The characteristics of the standard floor impact sources and the human impact source were investigated. First, the mechanical impedance of the each source was evaluated. Second, the impact force exposure levels and impact sounds level driven by the each source were measured. The results showed that the mechanical impedance and impact force exposure level of the impact ball are the most similar to those of the human impact source among the standard impact sources.

• Nuclear Engineering and Technology
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• v.54 no.9
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• pp.3336-3346
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• 2022

In general, a number of severe accident scenarios derived from Level 2 probabilistic safety assessment (PSA) are typically grouped into several categories to efficiently evaluate their potential impacts on the public with the assumption that scenarios within the same group have similar source term characteristics. To date, however, grouping by similar source terms has been completely reliant on qualitative methods such as logical trees or expert judgements. Recently, an exhaustive simulation approach has been developed to provide quantitative information on the source terms of a large number of severe accident scenarios. With this motivation, this paper proposes a machine learning-based categorization method based on exhaustive simulation for grouping scenarios with similar accident consequences. The proposed method employs clustering with an autoencoder for grouping unlabeled scenarios after dimensionality reductions and feature extractions from the source term data. To validate the suggested method, source term data for 658 severe accident scenarios were used. Results confirmed that the proposed method successfully characterized the severe accident scenarios with similar behavior more precisely than the conventional grouping method.