• Journal of the Korea Society of Computer and Information
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• v.29 no.1
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• pp.41-49
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• 2024

Speech recognition technology is continuously advancing and widely used in various fields. In this study, we aimed to investigate the impact of speech data quality on speech recognition models by dividing the dataset into the entire dataset and the top 70% based on Signal-to-Noise Ratio (SNR). Utilizing Seamless M4T and Google Cloud Speech-to-Text, we examined the text transformation results for each model and evaluated them using the Levenshtein Distance. Experimental results revealed that Seamless M4T scored 13.6 in models using data with high SNR, which is lower than the score of 16.6 for the entire dataset. However, Google Cloud Speech-to-Text scored 8.3 on the entire dataset, indicating lower performance than data with high SNR. This suggests that using data with high SNR during the training of a new speech recognition model can have an impact, and Levenshtein Distance can serve as a metric for evaluating speech recognition models.

• Journal of Korean Tunnelling and Underground Space Association
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• v.7 no.4
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• pp.295-304
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• 2005

The smoke propagating distances are measured in case that a fire occurs within the subway railroad tunnel. The tunnel is 800m long and the dimension of the cross-section is. Three vertical shafts exist for smoke ventilation. The experiments are performed using the 1/50 reduced-scale model. The smoke propagating distances are measured by thermocouples and by visualization for the accuracy. In order to understand the effect of a fire size and ventilation capacity of the shafts on the smoke propagating distance, 9 test scenarios are chosen. Based on the results, the smoke propagating distance is shown to be important criteria for the ventilation design of the tunnel.

• Journal of Environmental Science International
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• v.32 no.11
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• pp.801-809
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• 2023

The purpose of this study is to predict the reflection distance following to the pulsing pressure, total air supplying, filter bag size using numercial analysis techniques and use it as an efficient operation condition and economic data for off-line type pulse air jet bag filter. In this research, filtration area 6 m² condition, calculate filter resistance coefficient for simulation through the main experiments using coke dust. Ansys fluent V19.0 apply to CFD simulation, and analysis pulsing characteristics about pulsing pressure, filtration velocity and nozzle diameter. The maximum reflecting distance of off-line type pulse air jet bag filter is 1,000 mm regardless of total air supplying at over the 42 L/m² conditions, that indicates off-line type can extend filter bag length 1,000 mm than on-line type. In order to effective primary and secondary pulsing of off-line type pulse air jet bag filter, over the 5 bar of pulsing pressure and over the 42 L/m² of total air supplying are needed.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.1
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• pp.26-31
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• 2006

This study was conducted to determine the optimum number of inter-rows according to distance of drainage furrow (DF) for running-off excessive-water stress (EWS) in paddy field. The most soil water potential was shown in high ridge (distance of DF by 70 cm) cultivation and the soil water potential showed increasing tendency in over four inter-rows cultivation by DF. The growth of soybean reduced by extended inter-row and its reducing level was high, especially, over four inter-rows (DF distance by 2.8 m) because of EWS. The photosynthetic rate decreased in the more extensive field by distance of DF at V5 and R2 stages, especially, in over four interrows cultivation. Also, root activity decreased at wider DF. The yield was reduced with wider distance of DF more extensively, the highest yield of 270 g per $m^2$ at the every row, but yield showed decreasing tendency at over the $4^{th}$ row (2.8 m) cultivation. Soybean cultivation in paddy field could be founded with DF of every other or $4^{th}$ row.

• Journal of Power System Engineering
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• v.17 no.5
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• pp.121-127
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• 2013

In this paper, we propose a distance measurement system for automatic berthing control using a stereo camera mounted on a rotation control device, and a radial pattern target. Automatically controlling the position and attitude of a ship aims to prevent maritime accidents due to human error. Our goal is to measure the relative distance between a ship and an onshore or offshore target for berthing. Therefore, the distance should be continuously measured while tracking a fixed point on a target. To this end, we developed a stereo camerabased distance measurement system that satisfied these requirements. This paper describes the structure and principle of the measurement system. We validate the distance error for target incline due to the relative position and attitude between a camera and a target in miniature scale. In addition, the findings of an experiment in an outdoor environment demonstrate that the proposed measurement system has accuracy within 1 m at a range of 20-100 m which is the acceptable accuracy for automatic berthing.

• Journal of Bio-Environment Control
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• v.6 no.3
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• pp.183-189
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• 1997

This study was performed to Investigate size of droplet sprinkled from mini-sprinkler. Twelve different kinds of the sprinkler having various structures and sizes of nozzle orifices were selected and tested. Diameters of the droplet reached at several distances from a sprinkler were measured by a machine vision system and the volume median diameters (VMM) were determined statistically. The size of droplet was not affected much by the size of nozzle orifice of a sprinkler but was rather more affected by structure of the sprinkler, especially by the shape of spreader of the sprinkler. Experiment of varying pressure of sprinkling water validated that the size of droplet was inversely proportional to water pressure powered by 1/3. Hence the size of droplet at any water pressure could be easily estimated from experimental data. The size of droplet increased as travel distance of the droplet increases in a relationship of and order function. The size of droplet of the tested sprinkler were in the ranges of 100-300fm within 1m of droplet travel distance, 230~470${\mu}{\textrm}{m}$ within 1~2m of droplet travel distance and 300~770${\mu}{\textrm}{m}$ within 2~3m of droplet travel distance.

• Proceedings of the Korea Concrete Institute Conference
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• 1992.10a
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• pp.185-190
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• 1992

ACI318-89 Recommended that when the specified compressive strength of concrete in a column is greater than1.4 times that specified for a floor system, top surface of the column concrete shall extend 2ft(600mm)into the slab from the face of column to avoid unexpected brittle failure. The major variables are extension distance, flexural strength ratio(Mr), and shear reinforcement ratio(Vs). Test results are as follows ; (1) The failure modes of specimens under cyclic loading were concentrated at critical region from beam-column joint face. (2) Ductility index($\mu$f) were increased with increasing of shear confinement ratio and flexural strength ratio. (3)The specimens with 2ft extension distance showed more ductility than the specimens with 1ft extension distance.

• Journal of Magnetics
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• v.21 no.1
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• pp.102-109
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• 2016

In this paper, the theoretical and experimental characteristics of magnetic and electric fields in the vicinity of high voltage lines are investigated. To realize these measurements and calculations, we have developed some equations for two overhead power line configurations of 150 kV (single circuit, double circuit), based on Biot-savart law, image and Maxwell theories, in order to calculate the magnetic and electric fields. The measurements were done to a maximum distance from the tower of 50 m, at a height of 1m from the ground. These experiments take into consideration the real situations of the power lines and associated equipment. The experimental results obtained are near to that of the Biot-Savart theoretical results for a far distance from the tower; and for a distance close to the power line, the results from the image theory are in good agreement with the experimental results.

• IEMEK Journal of Embedded Systems and Applications
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• v.19 no.1
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• pp.33-38
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• 2024

In this paper, we propose the implementation of a drone delivery system using artificial intelligence in a situation where the use of drones is rapidly increasing and human errors are occurring. This system requires the implementation of an accurate control algorithm, assuming that last-mile delivery is delivered to the apartment veranda. To recognize the delivery location, a recognition system using the YOLO algorithm was implemented, and a delivery system was installed on the drone to measure the distance to the object and increase the delivery distance to ensure stable delivery even at long distances. As a result of the experiment, it was confirmed that the recognition system recognized the marker with a match rate of more than 60% at a distance of less than 10m while the drone hovered stably. In addition, the drone carrying a 500g package was able to withstand the torque applied as the rail lengthened, extending to 1.5m and then stably placing the package down on the veranda at the end of the rail.

• Proceedings of the KSRS Conference
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• v.2
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• pp.631-634
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• 2006

Three main important sources for establishing GIS are the orthomap in scale 1:5 000 with Ground Sampling Distance of 0,5m; DEM/DTM data with height error of ${\pm}$1,0m and topographic map in scale 1: 10 000. The new era with Very High Resolution Satellite (VHRS) images as IKONOS, QuickBird, EROS, OrbView and other ones having Ground Sampling Distance (GSD) even lower than 1m has been in potential for producing orthomap in large scale 1:5 000, to update existing maps, to compile general-purpose or thematic maps and for GIS. The accuracy of orthomap generated from VHRS image affects strongly on GIS reliability. Nevertheless, orthomap accuracy taken from VHRS image is at first dependent on chosen sensor geometrical models. This paper presents, at fist, theoretical basic of the Rational Polynomial Coefficient (RPC) model installed in the commercial ImageStation Systems, realized for orthorectifying VHRS images. The RPC model of VHRS image is a replacement camera mode that represents the indirect relation between terrain and its image acquired on the flight orbit. At the end of this paper the practical accuracies of IKONOS and QuickBird image orthorectified by RPC model on Canadian PCI Geomatica System have been presented. They are important indication for practical application of producing digital orthomaps.