• KSCE Journal of Civil and Environmental Engineering Research
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• v.36 no.4
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• pp.677-684
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• 2016

In order to improve the nighttime visibility of the lane, the need for the development of the automated line marking equipment is on the rise. The purpose of this study is to suggest performance assessment methodology that can be assessed from various aspects such as productivity, safety and quality performance of line marking equipment and to comprehensively analyze the performance of hand-operated and automated equipment based on field test. The following shows the results. It suggested a methodology capable of analyzing the performance of the line marking equipment in terms of productivity, safety and quality. Automated equipment for line marking was analyzed that can be obtained productivity achievement rate of 156.3% as compared with hand-operated equipment. On the basis of the expert advise and literature review, we derived twelve safety factors and ten quality factors of unit work in line marking. By utilizing the AHP technique, we estimated the importance of safety and quality factors. Automated equipment for line marking was analyzed to have been able to expect safety improvement rate of 49.8% and quality improvement rate of 47.2%. It is expected that the performance assessment methodology suggested in this study will be useful in analyzing objective and quantitative validity and expected effectiveness of the line marking equipment.

• Journal of Korean Society for Geospatial Information Science
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• v.17 no.3
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• pp.33-40
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• 2009

This paper proposes the assessment method for objective quality-evaluation-index of mosaic images. Quality assessment was evaluated using seam-line method and similarity and contrast of adjacent images. The evaluation measure was calculated based on selected evaluation criteria and compared with human visual inspection. It was found that quantitative quality evaluation measure showed that the evaluation results were similar to human visual check. Conclusively experimental results proved that proposed evaluation measure could be used for quantitative and objective quality assessment of mosaic images.

• Journal of IKEEE
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• v.16 no.3
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• pp.182-188
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• 2012

Here we propose an image quality assessment (IQA) based on histogram of oriented gradients (HOG). This method makes use of the characteristic that the histogram of gradient image describes the state of input image. In the proposed method, the image quality is derived by the slope of the HOG obtained from the target image. The line representing the HOG is measured by a random sample consensus (RANSAC) on the HOG. Simulation results based on the LIVE image quality assessment database suggest that the proposed method aligns better with how the human visual system perceives image quality than several state-of-the-art IQAs.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.48 no.2
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• pp.107-114
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• 1999

This paper presents an application of artificial neural networks(ANN) to assess the dynamic security of power systems. The basic role of ANN is to provide assessment of the system's stability based on training samples from off-line analysi. The critical clearing time(CCT) is an attribute which provides significant information about the quality of the post-fault system behaviour. The function of ANN is a mapping of the pre-fault, fault-on, and post-fault system conditions into the CCT's. In previous work, a feed forward neural network is used to learn this mapping by using the generation outputs during the fault as the input data. However, it takes significant calculation time to make the input data through the network reduction at a fault as the input data. However, it takes significant calculation time to make the input data through the network reduction at a fault considered. In order to enhance the speed of security assessment, the bus data and line powers are used as the input data of the ANN in thil paper. Test results show that the proposed neural networks have the reasonable accuracy and can be used in on-line security assenssment efficiently.

• The Bulletin of The Korean Astronomical Society
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• v.36 no.2
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• pp.73.2-73.2
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• 2011

We present a new database of absorption and emission-line measurements based on the entire spectral atlas from the Sloan Digital Sky Survey (SDSS) 7th data release of galaxies within a redshift of 0.2. Our work makes use of the publicly available penalized pixel-fitting(pPXF) and gas and absorption line fitting (gandalf) IDL codes, aiming to improve the existing measurements for stellar kinematics, the strength of various absorption-line features, and the flux and width of the emissions from different species of ionized gas. Our fit to the stellar continuum uses both standard stellar population models and empirical templates obtained by combining a large number of stellar spectra in order to fit a subsample of high-quality SDSS spectra for quiescent galaxies. Furthermore, our fit to the nebular spectrum includes an exhaustive list of both recombination and forbidden lines. Foreground Galactic extinction is implicitly treated in our models, whereas reddening in the SDSS galaxies is included in the form of a simple dust screen component affecting the entire spectrum that is accompanied by a second reddening component affecting only the ionised gas emission. Most notable of our work is that, we provide quality of the fit to assess reliability of the measurements. The quality assessment can be highly effective for finding new classes of objects. For example, based on the quality assessment around the Ha and [NII] nebular lines, we found approximately 1% of the SDSS spectra which classified as "galaxies" by the SDSS pipeline are in fact type I Seyfert AGN.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.49 no.6
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• pp.253-258
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• 2000

This paper presents an application of Kohonen neural networks to assess the dynamic security of power systems. The dynamic security assessment(DSA) is an important factor in power system operation, but conventional techniques have not achieved the desired speed and accuracy. The critical clearing time(CCT) is an attribute which provides significant information about the quality of the post-fault system behaviour. The function of Kohonen networks is a mapping of the pre-fault system conditions into the neurons based on the CCTs. The power flow on each line is used as the input data, and an activated output neuron has information of the CCT of each contingency. The trajectory of the activated neurons during load changes can be used in on-line DSA efficiently. The applicability of the proposed method is demonstrated using a 9-bus example.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.15 no.1
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• pp.71-81
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• 2005

The purposes of this study was to collect, analyze, and describe the MF exposure levels from subways in Korea and to measure and evaluate the MF levels generated from electric appliances used at general homes. The target subway lines were Seoul Metropolitan Line 1 to Line 8, Bundang Line, Incheon Line, Daegu Line, Gwangju Line, and Busan Line 1 and Line 2. We measured at each station in those subway lines and, all the train types (pantograph-equipped, motor-equipped, and common), and platform types(facing and isolating) were investigated by the distance(80, 200, 400 cm) from the train on 19 targeted subway lines using 3 magnetic field measuring devices (EMDEXII, Enertech Co.) during the survey from January till October, 2004. On the other hand, the levels of the 60Hz magnetic fields generated from 14 items of home electric appliances such as electric blankets, hair dryers, electric razors, etc. were measured at 10 general homes using 5 EMDEXII meters with a sampling interval of 1.5 second by the distance(surface, 30, 50, 100, 300cm ) from the target electric appliances. The survey results in the whole subway lines examined in this study were as follows; Seoul Metropolitan Line 4 using AC(alternating current) power source showed the highest mean value of $2.85{\mu}T$, followed by Seoul Metropolitan Line 1 running between Seoul and Incheon using AC($2.78{\mu}T$), Seoul Metropolitan Line 1 between Seoul and Uijongbu using AC($2.73{\mu}T$), Bundang Line using AC($1.79{\mu}T$), Seoul Metropolitan Line 1 connected from Yongsan using AC($1.67{\mu}T$), Seoul Metropolitan Line 1 between Seoul and Suwon using AC($0.79{\mu}T$), and so on. In general, the intensity of the magnetic field in the subway systems in Korea was significantly higher when using AC($2.14{\pm}0.91{\mu}T$) than when using DC($0.29{\pm}0.44{\mu}T$) power source. Among the home electric appliances examined, microwave ovens showed the highest mean value of $7.69{\mu}T$, followed by hair dryers($6.47{\mu}T$), vacuum cleaners($5.27{\mu}T$), televisions ($2.26{\mu}T$), electric blankets($1.38{\mu}T$), personal computers ($0.81{\mu}T$), and so on. Two items of electric appliances showed the excess value of $0.2{\mu}T$ at the distance of 30cm in the MF exposure level; electric razors $1.58{\pm}2.13{\mu}T$ and vacuum cleaners $0.48{\pm}0.44{\mu}T$. As a whole, this study showed a tendency that the shift of the MF levels according to the increase of distance from the electric appliances was lower than those of the results surveyed in UK and USA. As a result, this study is expected to suggest meaningful data for the future study in exposure assessment of magnetic fields and for the establishment of guidelines for subways and electric appliances in Korea. More detailed and large scaled exposure assessment studies should be performed continuously to get the various and useful information on health risk assessment of MFs in Korea.

• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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• 2001.06a
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• pp.1172-1172
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• 2001

Compact Near Infrared Diode Array Spectrometers offer new possibilities for on line quality assurance in the agricultural sector. Due to their speed and complete robustness towards temperature fluctuations and mechanical shock Diode Array Spectrometers are suitable for the use on Agricultural Harvest Machines. The growing consumer consciousness of food quality in combination with falling manufacturing prices demands procedures for an effective quality control system. The various conventional types of NIR instruments which have so far been used in laboratories are unsuitable for mobile applications under the rough conditions of field cropping not only because of their slow speed of measurement but also because of their shock sensitive filter wheels and monochromators necessary for fractionating polychromatic light. Another advantage of the on line use is the reduction of the sampling error because of the continuously measurement of the whole product. Considering the large economic importance of the dry matter content on agricultural products it is of particular advantage that water belongs to those constituents which are most easily assessed in the near infrared. While other constituents of economic importance such as starch, oil and protein in grains and seeds have a much lesser effect on NIR signals, their contents can nonetheless be assessed with high analytical precision on freshly harvested grains and seeds. In the last years several applications for on line quality assessment on harvesting machines were developed and tested. The talk will give an overview and outlook on existing and future possibilities of this new field of NIR applications.

• Journal of Korean Society of Water and Wastewater
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• v.33 no.4
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• pp.259-268
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• 2019

One of the most effective methods to consistently ensure the safety of a tap water supply can be achieved by application of a comprehensive risk assessment and risk management approach for drinking water supply systems. This approach can be termed water safety plans(WSP) which recommended by WHO(world health organization) and IWA(international water association). For the introduction of WSP into Korea, 150 hazards were identified all steps in drinking water supply from catchment to consumer and risk assessment tool based on frequency and consequence of hazards were developed. Then, developed risk assessment tool by this research was implemented at a water treatment plant($Q=25,000m^3/d$) to verify its applicability, and several amendments were recommended; classification of water source should be changed from groundwater to stream to strengthen water quality monitoring contaminants and frequencies; installation of aquarium to monitor intrusion of toxic substances into raw water; relocation or new installation on-line water quality analyzers for efficient water quality monitoring; change of chlorination chemical from solid phase($Ca(OCl)_2$) to liquid phase(NaOCl) to improve soundness of chlorination. It was also meaningful to propose hazards and risk assessment tool appropriate for Korea drinking water supply systems through this research which has been inconsistent among water treatment authorities.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.47 no.2
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• pp.77-85
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• 2010

Fingerprint image quality checking is one of the most important issues in on-line fingerprint recognition because the recognition performance is largely affected by the quality of fingerprint images. In the past, many related fingerprint quality checking methods have typically considered the local quality of fingerprint. However, It is necessary to estimate the global quality of fingerprint to judge whether the fingerprint can be used or not in on-line recognition systems. Therefore, in this paper, we propose both local and global-based methods to calculate the fingerprint quality. Local fingerprint quality checking algorithm considers both the condition of the input fingerprints and orientation estimation errors. The 2D gradients of the fingerprint images were first separated into two sets of 1D gradients. Then，the shapes of the PDFs(Probability Density Functions) of these gradients were measured in order to determine fingerprint quality. And global fingerprint quality checking method uses neural network to estimate the global fingerprint quality based on local quality values. We also analyze the matching performance using FVC2002 database. Experimental results showed that proposed quality check method has better matching performance than NFIQ(NIST Fingerprint Image Quality) method.