• The Journal of the Convergence on Culture Technology
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• v.8 no.6
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• pp.741-747
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• 2022

Fatigue lowers an individual's ability and makes it difficult to perform work. As fatigue accumulates, concentration decreases and thus the possibility of causing a safety accident increases. Awareness of fatigue is subjective, but it is necessary to quantitatively measure the level of fatigue in the actual field. In previous studies, it was proposed to measure the level of fatigue by expert judgment by adding objective indicators such as bio-signal analysis to subjective evaluations such as multidisciplinary fatigue scales. However this method is difficult to evaluate fatigue in real time in daily life. This paper is a study on the fatigue classification model that determines the fatigue level of workers in real time using speech data recorded in the field. Machine learning models such as logistic classification, support vector machine, and random forest are trained using speech data collected in the field. The performance evaluation showed good performance with accuracy of 0.677 to 0.758, of which logistic classification showed the best performance. From the experimental results, it can be seen that it is possible to classify the fatigue level using speech signals.

• Journal of Korean Medicine Rehabilitation
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• v.20 no.4
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• pp.33-49
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• 2010

Objectives : This study was designed to elucidate the anti-pathogenetic and curative effects of Gyehyeoldeungbokhap-bang(Jixietengfuge-fang, GCP) on Type II collagen-induced arthritis(CIA) in mice. Methods : In experiment, twenty four mices were divided into non-treated normal group(n=6), bovine type II collagen-induced control group(n=6), collagen immunized and treated two group medicated with extract of GCP(concentration of extraction: 200 mg/kg n=6, 400 mg/kg n=6) for 4 weeks after collagen immunization, Various experimental such as arthritis, incidence, index, total cell number of spleen, total cell number of peripheral lymph node(PLN), paw joint total cell number, analysis on the percentage of immunofluorescent cells of spleen in CIA induced mice, effects of inflammatory gene expression in spleen, PLN and paw joint of CIA mice, production of cytokine(IFN-${\gamma}$, IL-4, TNF-${\alpha}$, IL-6), analysis of rheumatoid factor(anti-collagen lgG, lgM level in serum) and histopathological study on the paw joint. The arthritis index, incidence were measured a week over 4 weeks after second boosting. Total cell number of spleen, peripheral lymph node, paw joint were measure after performed experiment over 7 weeks. Concentration of cytokine and rheumatoid factor in serum were measured after experiment finished. Histopathological study on the paw joint was measured after 40 days medicated with extract of GCP. Results : 1. Incidence of arthritis and index of arthritis were significantly decreased in treated group with 400 mg/kg. 2. Total cell number of spleen, PLN and paw joint were significantly decreased in treated group. 3. Analysis on the percentage of immunofluorescent cells of spleen in CIA induced mice were significantly controled compare with control group. 4. Effects of inflammatory gene expression in spleen, PLN and paw joint of CIA induced mice were significantly controled compare with control group. 5. IFN-${\gamma}$, IL-6, TNF-${\alpha}$, concentration($pg/m{\ell}$) in serum of treated group was significantly decreased compare with control group. But IL-4 was significantly increased. 6. lgM and lgG concentration($pg/m{\ell}$) in serum of treated group was significantly decreased compare with control group. 7. Histopathologically, suppurative and destructive lesion of synovial membrane, articular cartilage and subchondral bony tissue in treated group were alleviated compare with those of control group. Conclusions : Based on the results described above, it might be consider that Gyehyeoldeungbokhap-bang(Jixietengfuge-fang, GCP) has antiarthritic and analgesic effects and also inhibitory effects on the progression of collagen-induced arthritis mice.

• Journal of the Korean Society for Railway
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• v.20 no.1
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• pp.11-19
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• 2017

Since operation of railway trains is a major source of particle pollution in tunnel air, a particle removal device can be an effective measure to remove wear particles. To obtain design conditions of the particle removal device that will be installed underneath the railway trains, the wind speed and particle concentration underneath the trains were investigated using a three-dimensional ultrasonic anemometer and a DustTrak aerosol monitor, respectively. The measurements were made for the trains running on Seoul Metropolitan Subway Line 5 on February 10, 2015. The data were analyzed according to the track geometry (straight, curved) and train speed pattern (acceleration, cruising, and deceleration) between stations. Train speed was also analyzed. The average wind speed and $PM_{10}$ concentration underneath the trains were ~30% of the train speed and ${\sim}200{\mu}g/m^3$ for both straight and curved sections. Average $PM_{10}$ concentration for deceleration sections was higher than that for acceleration sections.

• Journal of the Korean GEO-environmental Society
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• v.14 no.11
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• pp.5-12
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• 2013

The purpose of this study is to estimate the behavior and the mechanism of debris flow at the end of mountain side when a berm was set on the inclined plane. The numerical model was performed by using the Finite Difference Method(FDM) based on the equation for the mass conservation and momentum conservation. In order to measure the behavior of the debris flow, the debris flow of a straight channel slope and the debris flow of channel slope with 3 types of berms were compared. First, the flow discharge and the sediment volume concentration at the downstream of the channel slope, depending on the various berm width and the different inflow discharges at the upstream of the channel were analyzed. The longer the berm width, the flow discharge at the downstream of the channel was decreased and the high flow fluctuation was reduced by a berm. And it means that a berm can effect for the delay of the debris flow. Through Root Mean Square ratio(RMS) comparison, the flow discharge of the channel slope with a berm was lower than that of a straight channel slope. The longer the berm width, for the sediment volume concentration, an inflection point did not show but mild curve. Because the low sediment concentration with water mixture by a berm continuously flow at the downstream end, it will be effect for reducing the disaster caused by debris flow. The results of this study will provide useful information in predicting and preventing disaster caused by the debris flow.

• Korean Journal of Poultry Science
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• v.24 no.4
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• pp.179-184
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• 1997

Seven-day-old 40 broiler chicks of both sexes were fed the conventional diet containing 0, 0.3, 6 and 0.9％ Quartz porphyry(QP) and water ad libitum until 28 days of age. The excreta water content and nitrogen balance were measured during the experimental period. At the end of the trial, blood samples were collected to measure ammonia, glucose, triglyceride, and total cholesterol concentrations. In addition, intestinal ammonia concentrations were measured. The excreta moisture contents decreased significantly(P < 0.05) as QP levels increased(r= -0.96). Ammonia contents in the intestine tended to increase as QP levels increased, but the ammonia concentration in the blood was not affected by the QP levels. The blood glucose concentration was not changed but blood triglyceride concentration was lower in the 0.3％ QP treatment than the other groups(P < 0.05), Total cholesterol concentration in the blood tended to increase as QP levels increased. The QP 0.3％ treatment showed somewhat higher positive N balance than the other groups. The results of this experiment indicate that the dietary supplementation of QP could offer some benefits to broiler growers.

• Journal of Korean Society for Atmospheric Environment
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• v.22 no.2
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• pp.259-266
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• 2006

A dual-channel glass coil sampling technique was used to measure hourly formaldehyde concentration in the ambient air. The dual-channel coil sampling assembly consists of three parts; an all-pyrex 28-turn coil made of 0.2-cm internal diameter glass tubing for gas-liquid contact and scrubbing of soluble gases, an inlet section upstream of the coil for introducing sample air and scrubbing solution, and a widened glass section downstream of the coil for gas-liquid separation. The scrubbing solution used was a dilute aqueous DNPH (dinitrophenylhydrazine) solution. Hourly concentration of formaldehyde was determined at a Gwangju semi-urban site during two intensive studies between September and October using the dual channel glass-coil/DNPH sampling technique and HPLC (High Performance Liquid Chromatography) analysis. The mean concentration was 1.7($0.4{\sim}4.7$) and 3.0($0.5{\sim}19.1$) ppbv for the September and October intensives, respectively, which are considerably low, compared to those measured in polluted urban areas around the world including several urban areas of Korea. The diurnal variation showed significant increase of formaldehyde in the daytime suggesting the dominance of formation of formaldehyde due to photochemical oxidation of methane and other hydrocarbons. An increase in the formaldehyde sometimes in the night might be due to an increase in primary source, i.e. traffic emissions. It was also found that rapid increase in formaldehyde levels from 3.0 to 19.1 ppbv in the afternoon on October 20 was due to plumes from burning of agricultural wastes such as rice straw and stubble. It is expected from the measurement data that the constructed dual-channel glass coil sampling system can be utilized for measuring atmospheric concentration of the formaldehyde with high time resolution.

• Journal of Biosystems Engineering
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• v.42 no.4
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• pp.350-357
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• 2017

Purpose: In-situ monitoring of water quality is fundamental to most environmental applications. The high cost and long delays of conventional laboratory methods used to determine water quality, including on-site sampling and chemical analysis, have limited their use in efficiently managing water sources while preventing environmental pollution. The objective of this study was to develop an on-site water monitoring system consisting mainly of an Arduino board and a sensor array of multiple ion selective electrodes (ISEs) to measure the concentration of $NO_3$ ions. Methods: The developed system includes a combination of three ISEs, double-junction reference electrode, solution container, sampling system consisting of three pumps and solenoid valves, signal processing circuit, and an Arduino board for data acquisition and system control. Prior to each sample measurement, a two-point normalization method was applied for a sensitivity adjustment followed by an offset adjustment to minimize the potential drift that could occur during continuous measurement and standardize the response of multiple electrodes. To investigate its utility in on-site nitrate monitoring, the prototype was tested in a facility where drinking water was collected from a water supply source. Results: Differences in the electric potentials of the $NO_3$ ISEs between 10 and $100mg{\cdot}L^{-1}$ $NO_3$ concentration levels were nearly constant with negative sensitivities of 58 to 62 mV during the period of sample measurement, which is representative of a stable electrode response. The $NO_3$ concentrations determined by the ISEs were almost comparable to those obtained with standard instruments within 15% relative errors. Conclusions: The use of the developed on-site nitrate monitoring system based on automatic sampling and two-point normalization was feasible for detecting abrupt changes in nitrate concentration at various water supply sites, showing a maximum difference of $4.2mg{\cdot}L^{-1}$ from an actual concentration of $14mg{\cdot}L^{-1}$.

• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.1392-1397
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• 2008

This study is to measure the change of the $CO_2$ and floating dust concentration depending on the volume of the ventilation and the state of on/off the ventilation for the estimation of the air pollution in classroom. The results could be summarized as follows: the test cell was the two full scaled model and the one is set up with ventilation system another was not. the volume of classroom is 170.1m3 and the number of persons are 35. 1)when the ventilation system was not installed, The experimental results of the $CO_2$ concentration showed the average of 2,150ppm and the maximum of 2,740ppm in the classroom. This was the higher than 1,000ppm, the standard value of ASHRAE and the enforcement regulations of School Sanitation Code in Ministry of Education & Human Resources Development, 1000ppm. The $CO_2$ concentration was relatively increasing during school hours. 3)In case of the volume of ventilation of $800m^3$/h, the $CO_2$ concentration of classroom showed the average of 962 ppm and the maximum of 1,380 ppm. This was higher than 1,000ppm, the standard of ASHRAE and the enforcement regulations of School Sanitation Code in Ministry of Education & Human Resources Development. 4)The floating dust(PM10) was the maximum of 0.52 mg/$m^3$, the minimum of 0.25 mg/$m^3$, and the average of 0.32 mg/$m^3$ in case of the ventilation system off. Those were higher than the standard value 0.15 mg/$m^3$. In case of the ventilation system on, the floating dust(PM10) was the maximum of 0.174 mg/$m^3$ , the minimum of 0.048 mg/$m^3$, and the average of 0.078 mg/$m^3$. These were the lower than 0.15 mg/$m^3$, the standard of the enforcement regulations of School Sanitation Code in Ministry of Education & Human Resources Development. 5)The concentrations of $CO_2$ and PM10 were largely depending on the number of students and the ventilation system, The installation of the ventilation system is necessary for the amenity environment and the management of the indoor air quality.

• Fire Science and Engineering
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• v.23 no.5
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• pp.24-31
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• 2009

Based on fallen leaves of major Korean conifer species 'Pinus densiflora' and major Korean broadleaved species 'Quercus variabilis', this study sought to identify combustion emission gas types and measure their concentration by means of FTIR (Fourier Transform Infrared) spectrometer. As a result, it was found that there were total 13 types of combustion gas detected from fallen leaves of Pinus densiflora and Quercus variabilis, such as carbon monoxide, carbon dioxide, acetic acid, butyl acetate, ethylene, methane, methanol, nitrogen dioxide, ammonia, hydrogen fluoride, sulfur dioxide and hydrogen bromide. Notably, nitrogen monoxide was additionally detected from fallen leaves of Quercus variabilis. It was found that the overall concentration of combustion gas emitted from the fallen leaves of Pinus densiflora was 4.5 times higher than that from fallen leaves of Quercus variabilis. Particularly, it was found that emission concentration of some combustion emission gas types like carbon monoxide, carbon dioxide and butyl acetate exceeded the upper limit of their time-weighted average (TWA, ppm), while the emission concentration of carbon monoxide and carbon dioxide exceeded their short-term exposure limit (STEL, ppm) for both species. Thus, it was found that carbon monoxide and carbon dioxide have higher hazard to health than other gas types, because these two gas types account for higher than 99% of overall gas emission due to combustion of surface fire starting from litter layer in forest.

• Food Science and Preservation
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• v.13 no.5
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• pp.616-622
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• 2006

This study was intended to analyze the contents of polyphenol compounds and vitamin C, and the inhibitory activities of xanthine oxidase and tyrosinase to measure physiological efface of various extract of Lespedeza bicolor. The vitamin C content was $26.42{\pm}0.08mg/100g$. The content of phenolic compounds included in the flesh L bicolor was $1.14{\pm}0.02mg/g$. The ethanol extract by reflux method and water extracts by the microwave-assisted method showed the highest content as 154.95 mg/g and 145.17 mg/g, respectively. The xanthine oxidase inhibitory tate of water extracts was the highest value of 87.85% at the concentration of 1,000 ug/mL. All kinds of extracts showed the highest inhibitory activity for the xanthine oxidase at the concentration of 1,000 ug/mL and a decreasing pattern of the inhibitory race over the concentration of 1,000 ug/mL. The tyrosinase inhibitory rate was increased with an increment of the extract concentrations, and the activity of ethanol extracts was the highest as 55.22% at the concentration of 3,000 ug/mL.